FLASKLESS MOLD MAKING DEVICE, FLASKLESS MOLD MAKING METHOD, AND SAND RECEIVING DEVICE

Abstract

 A flaskless mold making apparatus comprises: two pairs of upper and lower molding flasks 4, each pair consisting of an upper molding flask 2 and a lower molding flask 3; a flask turning mechanism 5 for turning the two pairs of upper and lower molding flasks to move the flasks into two stations consisting of a mold making station and a mold extraction station; a match plate 6; a pair of squeeze plates 7, 8; a sand tank 9; an extracting mechanism 15; and a hole forming mechanism 80 provided at a position in the mold extraction station and configured to form a hole or a plurality of holes in a mold in the upper molding flask out of the upper and lower molding flasks having been moved to the position.

Description

Technical Field

[0001] The present invention relates to a flaskless mold making apparatus, a flaskless mold making method, and a sand receiving apparatus for making flaskless upper and lower superimposed molds.

Background Art

[0002] The conventional flaskless mold making methods and apparatuses for making flaskless upper and lower molds include, for example, the method and apparatus described in Patent Literature 1. The mold making apparatus described in Patent Literature 1 has two pairs of upper and lower molding flasks, a match plate, a squeeze means, a means for rotating the squeeze means, a means for supplying sand, and a means for alternately turning the two pairs of upper and lower molding flasks between two stations.

[0003] The mold making method using this mold making apparatus allows simultaneous execution of a step of making molds in a pair of molds and a step of extracting molds from a pair of flasks internally having the previously-made molds, and thus has the advantage of efficiently performing the mold making process in a short period of time.

Citation List

Patent Literature

[0004] Patent Literature 1: Japanese Patent No. 4281742

Summary of Invention

Technical Problem

[0005] Incidentally, in a process of forming a casting with the use of a mold, a gas defect can cause a failure in the casting. In this technical field, there are demands for a flaskless mold making apparatus, a flaskless mold making method, and a sand receiving apparatus that enable efficient making of molds with capability of improvement in quality of castings, in a short period of time.

Solution to Problem

[0006] A flaskless mold making apparatus according to an aspect of the present invention comprises: two pairs of upper and lower molding flasks, each pair consisting of an upper molding flask and a lower molding flask; a flask turning mechanism for turning the two pairs of upper and lower molding flasks to move the flasks into two stations consisting of a mold making station and a mold extraction station; a match plate insertable into and retractable from between the upper and lower molding flasks located in the mold making station out of the two pairs of upper and lower molding flasks; a pair of squeeze plates configured to be inserted into respective openings of the upper and lower molding flasks with the match plate in between, the match plate having been inserted into between the upper and lower molding flasks, so as to form an upper making space and a lower making space; a sand tank having a pair of sand introducing nozzles for charging the upper making space and the lower making space respectively with sand; a squeeze mechanism for squeezing mold sand having been charged into the upper making space and the lower making space; an extracting mechanism provided in the mold extraction station and configured to extract an upper mold and a lower mold formed in the upper and lower molding flasks having been moved into the mold extraction station by the flask turning mechanism, in a superimposed state from the upper and lower molding flasks; and a hole forming mechanism provided in the mold extraction station and configured to form a hole or a plurality of holes in the mold in the upper molding flask out of the upper and lower molding flasks having been moved into the mold extraction station.

[0007] A flaskless mold making method according to another aspect of the present invention comprises: a step of moving upper and lower molding flasks consisting of an upper molding flask and a lower molding flask located in a mold making station and opposed to each other in a vertical direction, in directions to approach each other, thereby to interpose a match plate between the upper and lower molding flasks; a step of inserting a pair of squeeze plates into respective openings of the upper and lower molding flasks with the match plate in between, to form an upper making space and a lower making space; a step of charging mold sand from a sand tank into the upper making space and the lower making space; a step of moving the pair of squeeze plates toward the match plate to squeeze the mold sand in the upper making space and the lower making space; a step of moving the upper and lower molding flasks in directions to leave each other, thereby to separate the match plate from molds made in the upper and lower molding flasks; a step of turning the upper and lower molding flasks so as to move the upper and lower molding flasks with the molds formed therein in the mold making station, into a mold extraction station; a step of forming a hole or a plurality of holes in the mold in the upper molding flask out of the upper and lower molding flasks having been moved into the mold extraction station, by a hole forming mechanism; a step of moving the upper and lower molding flasks in directions to approach each other, thereby to superimpose the upper and lower molding flasks with the respective molds formed therein, on each other; and a step of extracting the respective molds in the upper and lower molding flasks in a superimposed state from the upper and lower molding flasks by a mold extracting mechanism having a member that can be inserted into the superimposed upper and lower molding flasks; in the two stations consisting of the mold making station and the mold extraction station, there are two pairs of upper and lower molding flasks, each pair consisting of an upper molding flask and a lower molding flask, provided in states of the steps according to the respective stations; the upper and lower molding flasks are turned to be moved into the two stations, thereby to sequentially make flaskless upper and lower superimposed molds.

[0008] A flaskless mold making method according to still another aspect of the present invention is a sand receiving apparatus to be provided in a mold making apparatus for making molds, or in a mold making line having a mold making apparatus for making molds, the sand receiving apparatus having: a first platelike member provided so as to be rotatable; a second platelike member for sand receiving provided so as to be movable in a projecting direction from a tip of the first platelike member and in a direction opposite thereto, the second platelike member being configured to receive sand produced in drilling at a position where the second platelike member projects out in the projecting direction with respect to the first platelike member while the first platelike member is located at a predetermined rotation position; a first cylinder configured to rotate the first platelike member; and a second cylinder configured to drive the second platelike member so as to perform a projecting operation and a retracting operation with respect to the first platelike member; before the drilling and after the drilling, the first platelike member is brought into a state in which the second platelike member is directed in a vertical direction and the second platelike member is brought into a state in which the second platelike member is retracted with respect to the first platelike member.

Advantageous Effects of Invention

[0009] The various aspects of the present invention provide the flaskless mold making apparatus, flaskless mold making method, and sand receiving apparatus enabling efficient making of molds with capability of improvement in quality of castings, in a short period of time.

Brief Description of Drawings

[0010] 

Fig. 1 is a front view of a mold making apparatus according to an embodiment.

Fig. 2 is a plan view of the mold making apparatus.

Fig. 3 is a side view of the mold making apparatus.

Fig. 4 is a drawing showing a state at an original position of the mold making apparatus, wherein (a) is a front view and (b) is a view on arrows A4-A4.

Fig. 5 is a drawing showing the mold making apparatus in a state in which a rotary frame is rotated from Fig. 4, wherein (a) is a front view and (b) is a view on arrows A5-A5.

Fig. 6 is a drawing showing the mold making apparatus in a state in which a match plate is inserted into between upper and lower molding flasks from Fig. 5, wherein (a) is a front view and (b) is a view on arrows A6-A6.

Fig. 7 is a drawing showing the mold making apparatus in a state in which flask setting and squeeze plate setting are conducted from Fig. 6 to form mold making spaces, wherein (a) is a front view and (b) is a view on arrows A7-A7.

Fig. 8 is a front view showing the mold making apparatus in a state in which the upper and lower molding flasks are rotated from Fig. 7 to be opposed to each other in the horizontal direction.

Fig. 9 is a front view showing the mold making apparatus in a state in which the inside of the upper and lower molding flasks is filled with sand from Fig. 8.

Fig. 10 is a front view showing the mold making apparatus in a state in which the mold sand is squeezed from Fig. 9.

Fig. 11 is a drawing showing the mold making apparatus in a state in which the upper and lower molding flasks are rotated from Fig. 10 to be opposed to each other in the vertical direction, wherein (a) is a front view and (b) is a view on arrows A11-A11.

Fig. 12 is a drawing showing the mold making apparatus in a state in which upper and lower molds are extracted from the match plate from Fig. 11, wherein (a) is a front view and (b) is a view on arrows A12-A12.

Fig. 13 is a drawing showing the mold making apparatus in a state in which the rotary frame is rotated from Fig. 12 (or in a state in which the rotary frame is moved back to the original position), i.e., in a state in which the flasks with the molds are moved into a mold extraction station, wherein (a) is a front view and (b) is a view on arrows A13-A13.

Fig. 14 is a drawing showing the mold making apparatus in a state in which a gas venting hole is formed from Fig. 13, wherein (a) is a front view and (b) is a view on arrows B 14-B 14.

Fig. 15 is a drawing showing the mold making apparatus in a state in which core setting is conducted from Fig. 14, wherein (a) is a front view and (b) is a view on arrows B15-B15.

Fig. 16 is a drawing for explaining a hole forming mechanism and a sand receiving mechanism used in the formation of gas venting hole shown in Fig. 14, wherein (a) is a drawing showing a standby state of the sand receiving mechanism (before drilling and after drilling), (b) is a drawing showing a sand receiving state of the sand receiving mechanism (during drilling), (c) is a drawing showing the schematic of the hole forming mechanism, and (d) is a view on arrows C16-C16.

Fig. 17 is a drawing showing the mold making apparatus in a state in which the flasks with the molds are superimposed on each other (to implement flask matching) from Fig. 15, wherein (a) is a front view and (b) is a view on arrow B17-B17.

Fig. 18 is a drawing showing the mold making apparatus in a state in which a pushing member starts pushing the upper and lower molds in extraction of the molds from Fig. 17, wherein (a) is a front view and (b) is a view on arrow B18-B18.

Fig. 19 is a drawing showing the mold making apparatus in a state in which during the extraction of molds, the molds are pushed downward by the pushing member in Fig. 18, thereby to lose the retaining force in relation with the flasks, and the molds are being moved downward by a table, wherein (a) is a front view and (b) is a view on arrow B19-B19.

Fig. 20 is a drawing showing the mold making apparatus in a state in which from Fig. 19, the molds are being moved downward by the table and the upper and lower molding flasks are moved back to the state at the original position, wherein (a) is a front view and (b) is a view on arrow B20-B20.

Fig. 21 is a drawing showing the mold making apparatus in a state in which from Fig. 20, the mold extraction operation is completed, wherein (a) is a front view and (b) is a view on arrow B21-B21.

Fig. 22 is a drawing showing the mold making apparatus in a state in which the upper and lower molds extracted in Fig. 21 are being pushed out to the outside of the apparatus, wherein (a) is a front view and (b) is a view on arrow B22-B22.

Fig. 23 is a side sectional view showing a cross section from a direction corresponding to Fig. 3, of the hole forming mechanism forming the mold making apparatus, which is a view on arrows X1-X1 shown in Figs. 2 and 26.

Fig. 24 is a side sectional view showing a cross section from a direction corresponding to Fig. 1, of the hole forming mechanism, which is a view on arrows X2-X2 shown in Figs. 2 and 26.

Fig. 25 is a sectional view showing a state in which the hole forming mechanism lowers drill members from the state shown in Fig. 24 to form gas venting holes.

Fig. 26 is a view on arrows X3-X3 shown in Figs. 23 and 24.

Fig. 27 is a sectional view showing a positional relation in the up-and-down direction in changing the position of the drill member of the hole forming mechanism in a horizontal plane.

Fig. 28 is a drawing for explaining the sand receiving mechanism forming the mold making apparatus, wherein (a) is a front view of the sand receiving mechanism, (b) is a side view, and (c) is a plan view.

Fig. 29 is a drawing for explaining an operation of the sand receiving mechanism, wherein (a) is a drawing showing a standby state of the sand receiving mechanism (before drilling and after drilling) and (b) is a sand receiving state of the sand receiving mechanism (during drilling).

Fig. 30 is a flowchart of a mold making method according to an embodiment.

Description of Embodiments

[0011] The flaskless mold making apparatus (which will be referred to hereinafter as "mold making apparatus"), flaskless mold making method, and sand receiving apparatus according to embodiments will be described below with reference to the drawings. Figs. 1 to 3 are "a front view," "a plan view," and "a side view" of the mold making apparatus 1 according to an embodiment. Figs. 4 to 22 are schematic views of front elevations and cross sections showing states of respective steps of performing mold making by the mold making apparatus 1. Figs. 4 to 22 are the schematic views without a base 22 and particulars, for explaining operations. In the drawings, the x- and y-directions are horizontal directions and the z-direction is the vertical direction (up-and-down direction).

[0012] As shown in Figs. 1 to 22, the mold making apparatus 1 is provided with two pairs of upper and lower molding flasks 4, each pair consisting of an upper molding flask 2 and a lower molding flask 3, a flask turning mechanism 5, a match plate 6, a pair of squeeze plates 7, 8, a sand tank 9, a rotating mechanism 10, a squeeze mechanism 11, an upper/lower molding flask moving mechanism 14, an extracting mechanism 15, and a hole forming mechanism 80.

[0013] The upper and lower molding flasks 4 are provided as two pairs, each pair consisting of an upper molding flask 2 and a lower molding flask 3. In Fig. 1 the upper molding flask 2 and the lower molding flask 3 are arranged opposite to each other in the up-and-down direction (z-direction). The two upper and lower molding flasks 4 are arranged next to each other in the x-direction. Each of the upper molding flask 2 and the lower molding flask 3 has an opening penetrating from top to bottom. Respective side walls of the upper molding flask 2 and the lower molding flask 3 are provided with sand inlets 2a, 3a for supplying mold sand into the upper molding flask 2 and the lower molding flask 3. The side walls herein are walls formed in a direction (e.g., the x-direction) perpendicular to the direction in which the upper molding flask 2 and the lower molding flask 3 are opposed to each other.

[0014] The flask turning mechanism 5 turns the two pairs of upper and lower molding flasks 4 to move them into two stations consisting of a mold making station and a mold extraction station. The mold turning mechanism 5 turns the two upper and lower molding flasks 4 around a rotational axis M1 extending in the up-and-down direction (the z-direction) while passing between the two upper and lower molding flasks 4 juxtaposed in a horizontal direction (the x-direction). In other words, the flask turning mechanism 5 turns the two upper and lower molding flasks 4 around the rotational axis M1 extending in the up-and-down direction (the z-direction) while passing between the mold making station and the mold extraction station juxtaposed in a horizontal direction (the x-direction). Here, the mold making station is a position where molds are made by squeezing mold sand in mold making spaces. The mold extraction station is a position where molds are extracted from the inside of the flasks. Namely, the flask turning mechanism 5 is a mechanism for intermittently turning the two pairs of upper and lower molding flasks in a horizontal state juxtaposed with each pair being vertically aligned, between the squeeze mechanism 11 with one pair of upper and lower molding flasks 2, 3 being horizontal and the extracting mechanism 15 for extracting molds. Furthermore, the flask turning mechanism 5 can retain the upper molding flasks 2 and move them up and down along the z-direction.

[0015] The match plate 6 is arranged so as to be insertable into and retractable from between the upper and lower molding flasks 4 located in the mold making station out of the two pairs of upper and lower molding flasks. This match plate 6 is arranged so as to be insertable and retractable by an inserting/retracting mechanism 21. Models are provided on both faces of the match plate 6 (Figs. 4 to 6).

[0016] The pair of squeeze plates 7, 8 are inserted into respective openings of the upper and lower molding flasks 4 with the match plate 6 in between, the match plate having been inserted into between the upper and lower molding flasks 4, to form an upper making space and a lower making space (Figs. 7 to 9). In other words, the squeeze plate 7 for the upper molding flask 2 is arranged so as to be insertable into and retractable from the upper opening which is not the lower opening where the match plate 6 is located, out of the openings of the upper molding flask 2. The squeeze plate 8 for the lower molding flask 3 is arranged so as to be insertable into and retractable from the lower opening which is not the upper opening where the match plate 6 is located, out of the openings of the lower molding flask 3.

[0017] The sand tank 9 has a pair of sand introducing nozzles 9a, 9b at a lower end thereof. The pair of sand introducing nozzles 9a, 9b are formed as directed downward and configured to charge each of the upper making space and the lower making space with sand. Mold sand is reserved in the sand tank 9 and the mold sand is supplied from the pair of sand introducing nozzles 9a, 9b into the upper and lower molding flasks 4 (Fig. 9).

[0018] The rotating mechanism 10 rotates the upper and lower molding flasks 4 forming the upper making space and the lower making space, in a rotating direction around a horizontal direction (the y-direction) to locate the sand inlets 2a, 3a so that sand can be charged therethrough from the pair of sand introducing nozzles 9a, 9b. Specifically, for example, the sand inlets 2a, 3a are brought into contact with the pair of sand introducing nozzles 9a, 9b, thereby realizing a sand chargeable state. Here, contact faces of the sand inlets 2a, 3a may be provided with elastic seal members and the seal members prevent sand from falling out from the contact faces. The rotating mechanism 10 is a horizontal cylinder extending in the x-direction and is configured to operate so as to telescopically move a rod 10a, thereby to rotate a rotary frame 24 attached to a tip of the rod 10a, in a direction R1 (Figs. 7 and 8). Then, the rotating mechanism 10 rotates the squeeze mechanism 11 and the upper and lower molding flasks 4, the match plate 6, the pair of squeeze plates 7, 8, etc. held thereby, in the same direction as the direction R1 and in the opposite direction thereto, through the rotary frame 24.

[0019] The squeeze mechanism 11 is rotated by the rotating mechanism 10 and configured to move the pair of squeeze plates 7, 8 toward the match plate 6 so as to squeeze the mold sand filled in the upper making space and the lower making space (Fig. 10). Furthermore, the squeeze mechanism 11 moves the pair of squeeze plates 7, 8 in directions to approach and leave each other in the aforementioned operation of forming the upper making space and the lower making space. The squeeze mechanism 11 is arranged so as to be rotatable between a posture in which the upper and lower molding flasks 4 with the match plate 6 in between are opposed to each other in the vertical direction and a posture in which the upper and lower molding flasks 4 are opposed to each other in the horizontal direction.

[0020] That the upper and lower molding flasks 4 are opposed to each other in the vertical direction refers to a situation in which the upper molding flask 2 and the lower molding flask 3 each are in a horizontal state. That the upper and lower molding flasks 4 are opposed to each other in the horizontal direction refers to a situation in which the upper molding flask 2 and the lower molding flask 3 each are in a vertical state.

[0021] Specifically, the squeeze mechanism 11 is attached to the rotary frame 24. The rotary frame 24 is arranged so as to be rotatable relative to a base 22 of a frame shape assembled in a nearly rectangular parallelepiped shape with a space for retaining the foregoing configuration inside. A support shaft 23 is provided on the base 22 and arranged so as to extend in a horizontal direction (the y-direction). The rotating mechanism 10 is, for example, a cylinder mechanism arranged horizontally so that its axis extends along the x-direction. The rotating mechanism 10 is joined to an upper portion of the rotary frame 24 by the support shaft 23. The rotary mechanism 10 is provided with the rod 10a. The tip of the rod 10a is joined to the upper portion of the rotary frame 24 to which the squeeze mechanism 11 is attached. This rod 10a is telescopically moved to rotate the rotary frame 24 and the squeeze mechanism 11 attached thereto, thereby to change the postures of the upper and lower molding flasks 4 (Figs. 7 and 8).

[0022] The upper/lower molding flask moving mechanism 14 moves the upper and lower molding flasks 4 in directions to leave each other so as to separate the match plate 6 from molds 12, 13 (e.g., Fig. 9) formed in the upper and lower molding flasks 4. Furthermore, the upper/lower molding flask moving mechanism 14 also moves the upper and lower molding flasks 4 in directions to approach each other, for example, in the aforementioned operation of interposing the match plate 6 between them. Specifically, the upper/lower molding flask moving mechanism 14 is composed of below-described upward cylinders 34, downward cylinders 35, upward cylinder 49, and so on.

[0023] The extracting mechanism 15 is provided at a position in the mold extraction station. The extracting mechanism 15 is configured as follows: when the upper and lower molding flasks 4 internally having the molds 12, 13 from which the match plate has been separated are moved into the mold extraction station by the flask turning mechanism 5, the extracting mechanism 15 extracts the upper mold 12 and the lower mold 13 formed in the upper and lower molding flasks 4, in a superimposed state from the upper and lower molding flasks 4.

[0024] The hole forming mechanism 80 is provided at a position in the mold extraction station and forms a hole or a plurality of holes 12a (each of which will also be referred to as "gas venting hole") in the mold 12 in the upper molding flask 2 out of the upper and lower molding flasks 4 having been moved to the position (Fig. 25).

[0025] A more specific configuration will be described below. In the aforementioned upper and lower molding flasks 4, the lower molding flask 3 is slidably laid between a pair of connection rods 25 provided downward from the upper molding flask 2 and hung thereon at the lower end position of the connection rods 25. The connection rods 25 connecting the upper molding flask 2 and the lower molding flask 3 are provided beside the upper and lower molding flasks 4 and at front and rear positions with respect to the turning direction (opposite positions in the y-direction). Furthermore, as shown in Fig. 4, the upper molding flask 2 is provided with a pair of engagement recesses 2b positioned on front and rear side faces with respect to the turning direction (the side faces opposite in the y-direction) and the engagement recesses 2b are in engagement with respective projections 48b of a below-described upper hook member 48. The lower molding flask 3 is provided with a pair of engagement recesses 3b positioned on front and rear side faces with respect to the turning (the side faces opposite in the y-direction) and the engagement recesses 3b are in engagement with respective projections 50b of a below-described lower hook member 50.

[0026] The inserting/retracting mechanism 21 for inserting and retracting the match plate 6, as shown in Fig. 5, has a rotary cylinder 26 attached to the rotary frame 24, arms 27 of a cantilever structure connected to the rotary cylinder 26, a cylinder 28 attached to tips of the arms 27, and a pendant carriage 29 freely movable back and forth in insertion and retraction directions with the match plate 6 thereon.

[0027] When the arms 27 are rotated in a direction R3 in Fig. 5 by action of the rotary cylinder 26, the pendant carriage 29 carries the match plate 6 into between the upper molding flask 2 and the lower molding flask 3 in the horizontal state through unshown rails provided on the flasks and the rotary frame 24 (Fig. 6). When the arms 27 are rotated backward, the pendant carriage 29 carries the match plate 6 out from between the upper and lower molding flasks. Furthermore, by telescopic motion of the cylinder 28 attached to the tips of the arms 27, the arms 27 are coupled to and uncoupled from the pendant carriage 29. In the uncoupled state, the match plate 6 can be replaced with another.

[0028] The squeeze mechanism 11 is rotatably supported through the rotary frame 24 on the support shaft 23 mounted in the center of the upper part of the base 22, as described above. The squeeze mechanism 11 is supported so as to be freely rotatable forward and backward in a vertical plane (xz plane). The upward cylinders 34 and the downward cylinders 35 are attached to the upper side and to the lower side, respectively, on the right side face of this rotary frame 24. The right side face of the rotary frame 24 herein is the side face on the right indicated by arrows A4-A4 in Fig. 4(a) and means the side face located on the center side of the flask turning mechanism 5. Furthermore, a front-and-rear direction is a direction connecting the front and rear with respect to the turning direction and is a tangent direction (the y-direction) in the mold making station.

[0029] The upward cylinders 34 are provided with an upper up-and-down frame 32. The downward cylinders 35 are provided with a lower up-and-down frame 33. These upper and lower up-and-down frames 32, 33 are arranged to approach and leave each other by telescopic motions of the upward cylinders 34 and the downward cylinders 35 mounted on the rotary frame 24.

[0030] A cylinder 36 for moving the upper squeeze plate 7 forward and backward is attached to the upper up-and-down frame 32. A cylinder 37 for moving the lower squeeze plate 8 forward and backward is attached to the lower up-and-down frame 33. The cylinder 36 and the cylinder 37 herein may be composed of a plurality of cylinders. The horizontal planes of the squeeze plates 7, 8 connected through the upper up-and-down frame 32 and through the lower up-and-down frame 33 have the size enough to push the upper molding flask 2 and the lower molding flask 3, respectively.

[0031] The sand tank 9 functions as a mechanism to implement sand charging, is mounted at a position nearer to the left on the ceiling part of the base 22 as shown in Figs. 1 and 4, and is formed in a bifurcate shape with the pair of sand introducing nozzles 9a, 9b at the lower end. The sand tank 9 is configured as a so-called aeration tank which is manufactured, for example, by sintering ultrahigh molecular weight polyethylene on the inner surface, is provided with a porous body as a filter part having a large number of holes, for example, of about 10 µm to 80 µm, and implements the sand charging while injecting air through the holes to float and fluidize sand, and the sand tank 9 operates to charge mold sand into the upper molding flask 2 and into the lower molding flask 3 independently of each other by low-pressure compressed air (aeration charging). The preferred level of pressure of the low-pressure compressed air is from 0.05 to 0.18 MPa.

[0032] The extracting mechanism 15 has a pushing member 38 which can be inserted into the upper and lower molding flasks 4 in the horizontal state as superimposed up and down, from top thereof and which pushes the upper and lower molds in the upper and lower molding flasks 4 downward (Figs. 17, 18, and 19). This pushing member 38 is fixed to a lower end of a piston rod of a downward cylinder 39 mounted on the ceiling part of the base 22. The pushing member 38 is moved up and down by telescopic motion of the cylinder 39. Below the pushing member 38, a mold receiving table 40 for receiving the upper and lower molds extracted from the upper and lower molding flasks 4 is provided so as to be movable up and down. The table 40 is fixed to a tip of a piston rod of an upward cylinder 41 and is moved up and down by telescopic motion of the cylinder 41.

[0033] The pushing member 38 operates as follows: while the upper and lower molding flasks 4 are mounted on the mold receiving table 40 (Fig. 17), the pushing member 38 is moved downward (Fig. 18). After the pushing member 38 is moved down to an upper mold pushing position, the pushing member 38 and the table 40 are further moved down to extract the molds 12, 13 from the inside of the upper molding flask 2 and the lower molding flask 3 (Figs. 18 and 19). Since the upper mold 12 and the lower mold 13 are in a state in which they are retained at their outer peripheries on the upper molding flask 2 and the lower molding flask 3 by force in the squeeze operation (or compressive force applied to sand), this retaining force at the outer peripheries is lost after the molds are pushed down to some extent from the upper molding flask 2 and the lower molding flask 3 by the pushing member 38; therefore, only the table 40 is then moved downward to implement extraction of the molds (Figs. 19 and 20)

[0034] The hole forming mechanism 80 is a mechanism which is provided at a position in the mold extraction station, for example as shown in Figs. 1, 3, 13, 14, and 16, and which is configured to form a hole or a plurality of holes in the mold 12 in the upper molding flask 2 out of the upper and lower molding flask 4 having been moved to the position. The hole forming mechanism 80 has a drill member 82 for drilling the upper mold 12 from top thereof. The drill member 82 does not have to be limited to one drill member but a plurality of drill members may be provided.

[0035] The extracting mechanism 15, as described above, has the pushing member 38 which downwardly pushes the upper mold 12 as superimposed on the lower mold 13 to extract the upper mold 12 and the lower mold 13 in the superimposed state from the upper and lower molding flasks 4. This pushing member 38 is provided with a penetration opening 38a through which the drill member 82 of the hole forming mechanism 80 can penetrate.

[0036] The hole forming mechanism 80 and the pushing member 38, which are configured as described above (in the configuration wherein the hole forming mechanism 80 is provided inside the pushing member 38), realize arrangement of a drilling mechanism for gas venting hole in the mold making apparatus 1 of the two-station system.

[0037] The pushing member 38, as shown in Fig. 16(d), has an outer periphery 38b in a horizontal plane (xy plane) formed in such a shape as to extend along the outer periphery of the upper surface of the upper mold 12. The penetration opening 38a has such a shape as to extend along the outer periphery 38b of the pushing member 38 and with a predetermined width therefrom. The pushing member 38 pushes the upper mold 12 downward by a portion 38c outside the penetration opening 38a and inside the outer periphery 38b of the pushing member 38 to extract the upper mold 12 and the lower mold 13 from the upper and lower molding flasks 4.

[0038] As described above, the pushing member 38 implements the extraction of the upper and lower molds 12, 13 by extinguishing the retaining force to the upper molding flask 2 and the lower molding flask 3 at the outer peripheries of the upper mold 12 and the lower mold 13, and the push on the region near the outer periphery with the aforementioned portion 38c enables proper flask removal. A reason why the proper flask removal can be done will be described. For example, supposing a case of a structure wherein the pushing portion of the "pushing member" is formed in a platelike shape and is configured to push the entire area of the upper surface of the upper mold, when this platelike portion is bent because of aging degradation and comes to first push the central part of the upper surface, sand in the outer peripheries of the molds tends to remain on the flask side, which raises a possibility of occurrence of breakage in the outer peripheries. In contrast to it, when the pushing portion has the structure (portion 38c) to push only the outer periphery like the pushing member 38 as shown in Fig. 16(d) and others, it becomes feasible to implement the proper extraction from the flasks 2, 3.

[0039] A more specific shape of the hole forming mechanism 80 will be described using Fig. 23 to 27. The hole forming mechanism 80 is provided with a drill unit 83 holding the drill members 82 and drill unit cylinders 84 as a drill unit driving mechanism for driving the drill unit 83 up and down in a hollow space in the pushing member 38. The drill unit cylinders 84 drive the drill unit 83 and the drill members 82 held thereby, up and down relative to the pushing member 38.

[0040] In this example, there are two drill unit cylinders 84, as shown in Fig. 26, located at two positions on both sides of the cylinder 39 for the pushing member 38 (for flask removal). This is for the purpose of implementing well-balanced drive of the drill unit 83. The number of drill unit cylinders does not have to be limited to this, but may be one or four. The cylinder 39 is not limited to that at one position, either, but a plurality of cylinders may be provided. In the example shown in Fig. 26, where there is the cylinder 39 at one position, a pair of guide rods 99 are provided so as to interpose the cylinder 39 between them, in order to implement well-balanced drive of the pushing member 38.

[0041] The drill unit 83 has a board member 85 provided with a plurality of attachment holes 85a and a unit main body 86 which can hold the board member 85 so as to allow attachment and detachment thereof (Figs. 16(d), 23, and 24). The unit main body 86 is provided with a roller member 87 to arrange the board member 85 as slidable in horizontal directions. The unit main body 86 is provided with a positioning pin for positioning and fixing not shown and this positioning pin enables fixing of the board member 85 inserted and attached to the unit main body 86 as slid on the roller member 87.

[0042] The drill member 82 can be selectively attached to and detached from any one of the attachment holes 85a of the board member 85. For example, the drill member 82 is configured so as to be separated into upper and lower parts in screw structure, and while a male screw part is inserted in the attachment hole 85a of the board member 85, screw structures of upper and lower members 82b, 82c above and below the board member 85 are engaged with each other to be attached to the board member 85.

[0043] Furthermore, there is an air guide branch part 88 for branching of air provided on the board member 85. The air guide branch part 88 is connected through an air hose 90 to an air guide part 89. The air guide part 89 is connected to an air supply part provided in the mold making apparatus 1. The air guide branch part 88 is connected through an air hose 91 to the drill members 82. The air guide branch part 88 supplies air supplied to the air guide part 89, to each drill member 82.

[0044] The drill members 82 are configured to rotate a drill part 82a by the supplied air. While rotating the drill parts 82a of the drill members 82, the drill unit cylinder 84 lowers the drill unit 83 to form the gas venting holes 12a in the upper mold 12 (Fig. 25). Before the formation of the gas venting holes 12a, spaces 12b for communication with the gas venting holes, which are to be connected to the gas venting holes 12a, are formed, together with a mold cavity 12c, in the upper mold 12 by the model of the match plate 6, as shown in Fig. 24. The drill members 82 are of the air system herein, but they may be of an electric actuation or hydraulic actuation system.

[0045] The hole forming mechanism 80 having the drill unit 83 enables change in position in a horizontal plane (xy plane) of the gas venting hole to be formed. Namely, for changing the position of the gas venting hole to be formed, the drill member 82 is attached simply to the attachment hole 85a corresponding to a desired position out of the plurality of attachment holes 85a formed in the board member 85. It is also possible to change the number of gas venting holes. This hole forming mechanism 80 is effective on such occasions as change in position of the model in conjunction with replacement of the match plate. The position of the drill member 82 is changed, as shown in Fig. 27, in a state in which the upper molding flask 2 is located down and the pushing member 38 is also located down, whereby the changing work becomes easier for a worker. The above-described configuration facilitates the position changing work of the drill member 82.

[0046] The mold making apparatus 1 has a sand receiving mechanism 100 below the upper molding flask 2 in the same station (the mold extraction station) as the hole forming mechanism 80 is located. The sand receiving mechanism 100 receives sand produced in drilling during a drilling work by the hole forming mechanism 80 and discharges the sand to the outside of the apparatus. The sand receiving mechanism 100 herein is configured to be attached to the rotary frame 43 and one sand receiving mechanism is arranged for each of the stations (the mold extraction station and the mold making station), but the apparatus does not have to be limited to this configuration. Namely, the sand receiving mechanism 100 needs only to function as a sand receiver at least in a situation where it is located in the mold extraction station and, for example, in a case where it is attached at a location where it is not rotated with the flasks, except for the rotary frame 43, it may be provided in the mold extraction station.

[0047] The sand receiving mechanism 100, as shown in Figs. 14, 16, 28, and 29, has a first platelike member 101 provided so as to be rotatable, and a second platelike member 102 provided so as to be movable in a projecting direction Y1 from a tip of the first platelike member 101 and in an opposite direction Y2 thereto. The second platelike member 102 is a sand receiving member for receiving sand produced in the drilling work by the hole forming mechanism 80 at a position where, while the first platelike member 101 is located at a predetermined rotation position, the second platelike member 102 projects out in the projecting direction with respect to the first platelike member 101.

[0048] In the periods other than the drilling work (before the drilling and after the drilling), the first platelike member 101 is kept in a state in which the second platelike member 102 is directed in the vertical direction. The second platelike member 102 is kept retracted with respect to the first platelike member 101 (Figs. 16(a) and 29(a)).

[0049] On the other hand, during the drilling work, the first platelike member 101 is brought into a state in which it is inclined relative to the horizontal direction so that the tip end thereof is located higher than the base end. On this occasion, the second platelike member 102 is brought into a state in which it projects out in the projecting direction Y1, relative to the first platelike member 101 (Figs. 16(b) and 29(b)).

[0050] The sand receiving mechanism 100 further has a first cylinder 103 for rotating the first platelike member 101, and a second cylinder 104 for driving the second platelike member 102. The second cylinder 104 drives the second platelike member 102 so as to perform the projecting operation and retracting operation with respect to the first platelike member 101.

[0051] The rotating operation of the first platelike member 101 by the first cylinder 103 will be described below in detail. The base end of the first platelike member 101 is a fixed portion 101a for a center of rotation, whereby the first platelike member 101 is arranged as rotatable. An extension member 101b provided as an extension from the fixed portion 101 a has a function to convert a linear motion of the first cylinder 103 into a rotational motion. A tip 103c of a rod 103b of the first cylinder 103 is attached to a tip portion 101c of the extension member 101b. On the other hand, the first cylinder 103 has a fixed portion 103a at its base end and is provided so as to be rotatable around the fixed portion 103 a.

[0052] When the first cylinder 103 is driven from the state as shown in Figs. 16(a) and 29(a) in an extending direction of the rod 103b thereof, the top side of the first cylinder 103 is slightly inclined to the left in the drawing and the top side of the first platelike member 101 comes to be largely inclined to the right. In conjunction therewith, the second cylinder 104 is driven in an extending direction of a rod 104b thereof. A tip 104c of the rod 104b is attached to the tip of the second platelike member 102 through an attachment member 102a. Therefore, as the rod 104b is extended, the second platelike member 102 is brought into the projecting state in the projecting direction Y1 with respect to the first platelike member 101 (Figs. 16(b) and 29(b)).

[0053] At this time, the first platelike member and the second platelike member are kept in the inclined state with respect to the horizontal direction (xy plane) and receive sand produced in the drilling while the drilling work by the hole forming mechanism 80 is conducted in this state. An angle θ of inclination with respect to the horizontal direction LH to be adopted herein is in the range of 5° to 45°. Even if the inclination is smaller than 5° or is horizontal, they can function as a sand receiver, but there is a possibility of sand slightly falling out from the tip side onto the lower mold during the discharge to the outside, and this possibility can be kept smaller in the foregoing angle range. If the inclination is larger than 45°, the size of the first and second platelike members 101, 102 will become larger. The foregoing inclination angle may be set in the range of 20° to 40°.

[0054] As the drilling work is carried out by the hole forming mechanism 80 in the state as shown in Figs. 16(b) and 29(b), the sand produced in the drilling work is kept as received on the second platelike member 102. Then the rod 103b and the rod 104b are driven in their contracting direction to drive the first platelike member 101 so as to be directed in the vertical direction, and the second platelike member 102 is driven in the retracting direction Y2 with respect to the first platelike member 101. This operation results in discharging the sand received on the second platelike member 102, to below the fixed portion 103a, i.e., to the outside of the apparatus. A sand receiving vessel or the like may be located at a position below the fixed portion 103a.

[0055] As described above, the sand receiving mechanism 100 prevents unnecessary sand produced in the drilling work by the hole forming mechanism 80 from depositing on the mold or a core in the lower molding flask 3, or prevents a failure of a casting. Since the apparatus is provided with the first platelike member 101, the second platelike member 102, the first cylinder 103, and the second cylinder 104, the functions thereof can be exhibited in the compact configuration and the overall configuration of the apparatus can also be simplified and downsized. The sand receiving mechanism described above (which is also called "sand receiving apparatus") 100 can be used not only in the flaskless mold making apparatuses but also in flask-attached mold making apparatuses configured to carry out the made molds along with the flasks, and in a mold making line with the mold making apparatus.

[0056] The hole forming mechanism 80 and the sand receiving mechanism 100 realize automatic formation of gas venting hole, thereby to prevent the failure due to the gas defect from occurring in castings. The mold making apparatus 1 is provided with the hole forming apparatus, which has been considered heretofore that it was difficult to provide the hole forming apparatus in the flaskless mold making apparatus of the two-station system, thereby to realize automation of the drilling work of gas venting hole.

[0057] The flask turning mechanism 5, as shown in Figs. 4, 5, 12, 13, and 14, has the rotary frame 43 which is turned while holding the upper and lower molding flasks 4, and a rotary frame driving means 44. As shown in Fig. 14, the rotary frame driving means 44 has a tip of a rod 44a attached to an attachment part 43a of the rotary frame 43 and telescopically moves the rod 44a to invert the rotary frame 45 180° around the rotational axis M1 as an axis of rotation in one direction and in a direction opposite thereto. The flask turning mechanism 5 can turn the two pairs of upper and lower molding flasks 4 in order into the mold making station and the mold extraction station by the forward and backward motions.

[0058] A support member 46 is mounted on the top of the rotary frame 43 (Figs. 1 to 3). The support member 46 is provided with two pairs of guide rods 47 extending downward in the vertical direction and paired at a required interval in the front-and-rear direction.

[0059] The upper hook member 48 on which the engagement recesses 2b of the upper molding flask 2 can be hooked is provided so as to be vertically slidable, for each pair of the two pairs of guide rods 47. A tip of a piston rod of the upward cylinder 49 mounted on the rotary frame 43 is secured to each upper hook member 48. Each upper hook member 48 is moved up and down by telescopic motion of this upward cylinder 49. Furthermore, the lower hook member 50 on which the engagement recesses 3b of the lower molding flask 3 can be hooked is fixed to the lower ends of the two pairs of guide rods 47. The upper hook member 48 is provided with projections 48b to be engaged with the engagement recesses 2b. The lower hook member 50 is provided with projections 50b to be engaged with the engagement recesses 3b.

[0060] In the mold extraction station there is a mold discharging mechanism 51 which pushes the upper and lower molds 12, 13 extracted onto the mold receiving table 40 from the upper molding flask 2 and the lower molding flask 3 by the extracting mechanism 15, to discharge them (Figs. 21 and 22).

[0061] Next, a mold making method using the mold making apparatus 1 configured as described above will be described. This mold making method is one for making flaskless upper and lower molds, as described above. Fig. 30 is a flowchart of the mold making method.

[0062] First, as shown in Fig. 30, the rotary frame 43 rotates from the basic posture (also referred to as "original position") as shown in Fig. 4. This rotation results in replacing the upper and lower molding flasks 2, 3 located in the mold making station with the upper and lower molding flasks 2, 3 located in the mold extraction station (Fig. 5). Namely, the upper and lower molding flasks 4 as a processing target are moved into the mold making station (S10).

[0063] Next, the rotary cylinder 26 of the inserting/retracting mechanism 21 is rotationally driven from the state shown in Fig. 5. This drive results in inserting the match plate 6 into between the upper molding flask 2 and the lower molding flask 3 in the horizontal state by the pair of arms 27 rotated in the direction R3, as shown in Fig. 6 (S12).

[0064] Next, the squeeze mechanism 11 operates to contract the upward cylinder 34 and the downward cylinder 35 to bring the upper molding flask 2 and the lower molding flask 3 closer to each other through the upper and lower up-and-down frames 32, 33. The upper and lower molding flasks 4 located closer to each other by the squeeze mechanism 11 are in a state in which the match plate 6 is interposed between them (S14). In this state the squeeze mechanism 11 operates to extend each of the cylinders 36, 37 by a required length. The cylinders 36, 37 insert the upper squeeze plate 7 and the lower squeeze plate 8 into the upper molding flask 2 and the lower molding flask 3, respectively. The upper squeeze plate 7 and the lower squeeze plate 8, together with the upper molding flask 2 and lower molding flask 3 and the match plate 6, form two mold making spaces up and down (the upper making space and lower making space) (Fig. 7, S16).

[0065] The rotating mechanism 10 extends the rod 10a to rotate the squeeze mechanism 11 around the support shaft 23 in the direction R1, as shown in Fig. 8. The rotating mechanism 10, on this occasion, brings the upper molding flask 2, the lower molding flask 3, and the match plate 6 into the vertical state. The sand inlets 2a, 3a provided in the side walls of the upper molding flask 2 and the lower molding flask 3 are moved upward so as to face up. Furthermore, the sand inlets 2a, 3a of the upper and lower molding flasks 4 are brought into contact with the sand introducing nozzles 9a, 9b provided at the lower ends of the bifurcate shape of the sand tank 9 configured as an aeration tank (S18).

[0066] Next, the sand tank 9 as a sand charging mechanism charges the upper making space and the lower making space with mold sand through the sand inlets 2a, 3a, as shown in Fig. 9 (S20). Thereafter, as shown in Fig. 10, the cylinders 36, 37 are actuated to move the upper squeeze plate 7 and the lower squeeze plate 8 in the directions to approach the match plate 6, so as to squeeze the mold sand in the two upper and lower making spaces (S22).

[0067] The rotating mechanism 10, as shown in Fig. 10, rotates the upper molding flask 2, the lower molding flask 3, and the match plate 6 in the opposite direction R2 to the foregoing rotation direction R1 to bring them into the horizontal state (Fig. 11).

[0068] Next, the upward cylinders 34 and the downward cylinders 35 operate to extend so as to separate the upper and lower up-and-down frames 32, 33 from each other. Subsequently, the flask turning mechanism 5 operates to extend the cylinder 49 so as to raise the upper molding flask 2 internally holding the mold of squeezed mold sand, by the upper hook member 48. This operation results in separating the match plate 6 from the upper molding flask 2 and the lower molding flask 3 (Fig. 12, S24). In this manner, the cylinder 49 provided in the turning portion separates the upper molding flask 2 from the match plate 6. The lower molding flask 3 is mounted onto the lower hook member 50 of the flask turning mechanism 5 by the cylinders 35.

[0069] Next, the rotary cylinder 26 operates to rotate so as to retract the match plate 6 from between the upper molding flask 2 and the lower molding flask 3 by the pair of arms 27 (S26). Subsequently, the flask turning mechanism 5 rotates the rotary frame 43 to move the upper and lower molding flasks 4 with the molds 12, 13 formed therein, from the mold making station into the mold extraction station. At the same time, the upper and lower molding flasks 4 from which the molds 12, 13 have been extracted in the mold extraction station are moved into the mold making station (Fig. 13, S28).

[0070] Next, as shown in Fig. 14, the hole forming mechanism 80 forms the gas venting holes (S30). At the same time, sand produced in the formation of gas venting holes is collected and discharged to the outside of the apparatus by the sand receiving mechanism 100. Next, as shown in Fig. 15, a worker places the core 110 (core setting) (S32). The core setting may be performed before the formation of gas venting holes shown in Fig. 14. The core setting may be excluded.

[0071] The cylinder 49 is operated to contract so as to lower the upper molding flask 2 internally holding the mold 12, through the upper hook member 48 and mount the upper molding flask 2 on the lower molding flask 3, as shown in Fig. 17, thereby to implement superposition of the upper and lower molding flasks 4 (S34). In conjunction therewith, the mold receiving table 40 is raised by extending motion of the cylinder 41 of the mold extraction mechanism 15 to place the upper and lower molds 12, 13 in the upper and lower molding flasks 4 on the table 40.

[0072] Next, the cylinder 39 of the mold extracting mechanism 15 operates to extend so as to lower the pushing member 38 to the pushing position on the upper molding flask 12, and thereafter, the pushing member 38 and the table 40 are lowered in synchronism with each other to extract the molds from the inside of the upper molding flask 2 and the lower molding flask 3 (Figs. 18, 19, 20, and 21, S36). Subsequently, the rod 51a of the mold discharging mechanism 51 is extended to push the upper and lower molds 12, 13 on the table 40 in the direction of arrow W in the drawing, as shown in Fig. 22 (S38).

[0073] As described above, the mold making method has the following steps. Specifically, the step of S14 is to move the upper and lower molding flasks 4 consisting of the upper molding flask 2 and the lower molding flask 3 located in the mold making station and opposed in the vertical direction, in the directions to approach each other, thereby to interpose the match plate 6 between them. The step of S16 is to insert the pair of squeeze plates 7, 8 into the respective openings of the upper and lower molding flasks 4 with the match plate 6 between them, to form the upper making space and the lower making space. The step of S 18 is to rotate the upper and lower molding flasks 4 forming the upper making space and the lower making space, in the direction around the axis of the horizontal direction to locate the the sand inlets 2a, 3a provided in the respective side walls of the upper and lower molding flasks 4 so that sand can be charged through the sand inlets 2a, 3 a from the pair of sand introducing nozzles 9a, 9b formed downward from the lower end of the sand tank 9. The step of S20 is to charge the mold sand from the sand tank 9 through the sand inlets 2a, 3a into the upper making space and the lower making space. The step of S22 is to move the pair of squeeze plates 7, 8 toward the match plate 6 to squeeze the mold sand in the upper making space and the lower making space. The step of S24 is to rotate the upper and lower molding flasks 4 into the posture in which they are opposed to each other in the vertical direction. Furthermore, the step of S24 is to move the upper and lower molding flasks 4 in the directions to leave each other, thereby to separate the match plate 6 from the molds formed in the upper and lower molding flasks. The step of S28 is to turn the upper and lower molding flasks so as to move the upper and lower molding flasks with the molds formed therein in the mold making station, into the mold extraction station. The step of S30 is to form one hole or a plurality of holes in the mold in the upper molding flask out of the upper and lower molding flasks having been moved into the mold extraction station, by the hole forming mechanism. The step of S34 is to move the upper and lower molding flasks in the directions to approach each other, thereby to superimpose the upper and lower molding flasks with the respective molds formed therein, on each other. The step of S36 is to extract the respective molds in the upper and lower molding flasks in the superimposed state from the upper and lower molding flasks by the mold extracting mechanism 15 having the member that can be inserted into the superimposed upper and lower molding flasks. In the mold making method, the two pairs of upper and lower molding flasks, each pair consisting of the upper molding flask and the lower molding flask, which are brought into the states of the steps according to the respective stations, are provided in the two stations consisting of the aforementioned mold making station and mold extraction station, and the upper and lower molding flasks are turned to move into the two stations, thereby to sequentially make the flaskless upper and lower superimposed molds.

[0074] This mold making method has the above-described characteristic configuration to form the gas venting holes 12a, thereby preventing the occurrence of the failure due to the gas defect in castings. Therefore, it achieves improvement in quality of castings.

[0075] The mold making method according to an embodiment may include receiving and discharging the sand produced in the drilling work, by the sand receiving mechanism 100 provided at the position in the same station as the hole forming mechanism is located. In this manner, the sand produced during the drilling work is prevented from dropping onto the lower mold, whereby the formation of gas venting hole can be automated and the quality of castings is prevented from being degraded by the sand.

[0076] As described above, the mold making apparatus 1 of the present embodiment has the two pairs of upper and lower molding flasks 4, each pair consisting of the upper molding flask 2 and the lower molding flask 3, the flask turning mechanism 5, the match plate 6, the pair of squeeze plates 7, 8, the sand tank 9, the extracting mechanism 15, and the hole forming mechanism 80. This mold making apparatus 1 is configured so that the hole forming mechanism 80 forms the gas venting holes 12a, thereby to prevent the failure due to the gas defect from occurring in castings. Therefore, it achieves improvement in quality of castings.

[0077] The mold making apparatus 1 is configured to receive the sand produced as shaved off during the drilling work, by the sand receiving mechanism 100 and discharge the sand to the outside of the apparatuseso as to prevent the sand from dropping onto the lower mold and the core, thus realizing automation of the formation of gas venting hole and preventing the sand from degrading the quality of castings.

[0078] The above described the two-station mold making apparatus, but the mold making apparatus may have three or more stations among which the flask removal station is provided with the hole forming mechanism 80 and the sand receiving mechanism 100. In cases of three or more stations, any station other than the flask removal station may be provided with the hole forming mechanism 80 and the sand receiving mechanism 100.

Reference Signs List

[0079] 1 mold making apparatus; 2 upper molding flask; 3 lower molding flask; 6 match plate; 80 hole forming mechanism; 100 sand receiving mechanism.

Claims

1. A flaskless mold making apparatus comprising:

two pairs of upper and lower molding flasks, each pair consisting of an upper molding flask and a lower molding flask;

a flask turning mechanism for turning the two pairs of upper and lower molding flasks to move the two pairs of upper and lower molding flasks into two stations consisting of a mold making station and a mold extraction station;

a match plate insertable into and retractable from between the upper and lower molding flasks located in the mold making station out of the two pairs of upper and lower molding flasks;

a pair of squeeze plates configured to be inserted into respective openings of the upper and lower molding flasks with the match plate in between, the match plate having been inserted into between the upper and lower molding flasks, so as to form an upper making space and a lower making space;

a sand tank having a pair of sand introducing nozzles for charging the upper making space and the lower making space respectively with sand;

a squeeze mechanism for squeezing mold sand having been charged into the upper making space and the lower making space;

an extracting mechanism provided in the mold extraction station and configured to extract an upper mold and a lower mold formed in the upper and lower molding flasks having been moved into the mold extraction station by the flask turning mechanism, in a superimposed state from the upper and lower molding flasks; and

a hole forming mechanism provided in the mold extraction station and configured to form a hole or a plurality of holes in the mold in the upper molding flask out of the upper and lower molding flasks having been moved into the mold extraction station.

2. The flaskless mold making apparatus according to Claim 1,
wherein the hole forming mechanism has a drill member or a plurality of drill members for drilling the upper mold from top thereof,
wherein the extracting mechanism has a pushing member configured to push the upper mold in a superimposed state on the lower mold downward to extract the upper mold and the lower mold in the superimposed state from the upper and lower molding flasks, and
wherein the pushing member is provided with a penetration opening through which the drill member can penetrate.

3. The flaskless mold making apparatus according to Claim 2,
wherein the pushing member has an outer periphery in a horizontal plane formed in such a shape as to extend along an outer periphery of an upper surface of the upper mold,
wherein the penetration opening has such a shape as to extend along the outer periphery of the pushing member and with a predetermined width therefrom, and
wherein the pushing member pushes the upper mold downward by a portion outside the penetration opening and inside the outer periphery of the pushing member, to extract the upper mold and lower mold from the upper and lower molding flasks.

4. The flaskless mold making apparatus according to Claim 3,
wherein the hole forming mechanism has: a drill unit holding the drill member; and a drill unit driving mechanism for driving the drill unit up and down relative to the pushing member,
wherein the drill unit has: a board member provided with a plurality of attachment holes; and a unit main body which the board member can be attached to and detached from, and
wherein the drill member is selectively attachable to and detachable from one of the attachment holes of the board member.

5. The flaskless mold making apparatus according to any one of Claims 1 to 4, comprising a sand receiving mechanism provided at a position in the mold extraction station and configured to receive sand produced in drilling during a drilling work by the hole forming mechanism below the upper molding flask at the position and discharge the sand to the outside of the apparatus.

6. The flaskless mold making apparatus according to Claim 5,
wherein the sand receiving mechanism has a first platelike member provided so as to be rotatable; and a second platelike member for sand receiving provided so as to be movable in a projecting direction from a tip of the first platelike member and in a direction opposite thereto, the second platelike member being configured to receive the sand produced in the drilling at a position where the second platelike member projects out in the projecting direction with respect to the first platelike member, while the first platelike member is located at a predetermined rotation position, and
wherein before the drilling and after the drilling, the first platelike member is brought into a state in which the second platelike member is directed in a vertical direction and the second platelike member is brought into a state in which the second platelike member is retracted with respect to the first platelike member.

7. The flaskless mold making apparatus according to Claim 6,
wherein during the drilling, the first platelike member is brought into a state in which the first platelike member is inclined with respect to a horizontal direction so that a tip end is located above a base end, and the second platelike member is brought into a state in which the second platelike member projects out in the projecting direction with respect to the first platelike member.

8. The flaskless mold making apparatus according to Claim 7,
wherein the sand receiving mechanism has a first cylinder for rotating the first platelike member; and a second cylinder for driving the second platelike member so as to perform a projecting operation and a retracting operation with respect to the first platelike member.

9. A flaskless mold making method comprising:

a step of moving upper and lower molding flasks consisting of an upper and a lower molding flask located in a mold making station and opposed to each other in a vertical direction, in directions to approach each other, thereby to interpose a match plate between the upper and lower molding flasks;

a step of inserting a pair of squeeze plates into respective openings of the upper and lower molding flasks with the match plate in between, to form an upper making space and a lower making space;

a step of charging mold sand from a sand tank into the upper making space and the lower making space;

a step of moving the pair of squeeze plates toward the match plate to squeeze the mold sand in the upper making space and the lower making space;

a step of moving the upper and lower molding flasks in directions to leave each other, thereby to separate the match plate from molds made in the upper and lower molding flasks;

a step of turning the upper and lower molding flasks so as to move the upper and lower molding flasks with the molds formed therein in the mold making station, into a mold extraction station;

a step of forming a hole or a plurality of holes in the mold in the upper molding flask out of the upper and lower molding flasks having been moved into the mold extraction station, by a hole forming mechanism;

a step of moving the upper and lower molding flasks in directions to approach each other, thereby to superimpose the upper and lower molding flasks with the respective molds formed therein, on each other; and

a step of extracting the respective molds in the upper and lower molding flasks in a superimposed state from the upper and lower molding flasks by a mold extracting mechanism having a member that can be inserted into the superimposed upper and lower molding flasks;

wherein in the two stations consisting of the mold making station and the mold extraction station, there are two pairs of upper and lower molding flasks, each pair consisting of an upper molding flask and a lower molding flask, provided in states of the steps according to the respective stations, and the upper and lower molding flasks are turned to be moved into the two stations, thereby to sequentially make flaskless upper and lower superimposed molds.

10. The flaskless mold making method according to Claim 9,
wherein the hole forming mechanism has a drill member or a plurality of drill members for drilling the upper mold formed in the upper molding flask of the upper and lower molding flasks, from top thereof,
wherein the mold extracting mechanism has a pushing member configured to push the upper mold in a superimposed state on the lower mold downward to extract the upper mold and the lower mold in the superimposed state from the upper and lower molding flasks, and
wherein the pushing member is provided with a penetration opening through which the drill member can penetrate.

11. The flaskless mold making method according to Claim 10,
wherein the pushing member has an outer periphery in a horizontal plane formed in such a shape as to extend along an outer periphery of an upper surface of the upper mold,
wherein the penetration opening has such a shape as to extend along the outer periphery of the pushing member and with a predetermined width therefrom, and
wherein the pushing member pushes the upper mold downward by a portion outside the penetration opening and inside the outer periphery of the pushing member, to extract the upper mold and lower mold from the upper and lower molding flasks.

12. The flaskless mold making method according to Claim 11,
wherein the hole forming mechanism has: a drill unit holding the drill member; and a drill unit driving mechanism for driving the drill unit up and down relative to the pushing member,
wherein the drill unit has: a board member provided with a plurality of attachment holes; and a unit main body which the board member can be attached to and detached from, and
wherein the drill member is selectively attachable to and detachable from one of the attachment holes of the board member.

13. The flaskless mold making method according to any one of Claims 9 to 12, wherein the step of forming a hole or a plurality of holes by the hole forming mechanism comprises using a sand receiving mechanism provided at a position in the mold extraction station, to receive sand produced in drilling during a drilling work by the hole forming mechanism below the upper molding flask at the position and discharge the sand to the outside of the apparatus.

14. The flaskless mold making method according to Claim 13,
wherein the sand receiving mechanism has a first platelike member provided so as to be rotatable; and a second platelike member for sand receiving provided so as to be movable in a projecting direction from a tip of the first platelike member and in a direction opposite thereto, the second platelike member being configured to receive the sand produced in the drilling at a position where the second platelike member projects out in the projecting direction with respect to the first platelike, member while the first platelike member is located at a predetermined rotation position, and
wherein before the drilling and after the drilling, the first platelike member is brought into a state in which the second platelike member is directed in a vertical direction and the second platelike member is brought into a state in which the second platelike member is retracted with respect to the first platelike member.

15. The flaskless mold making method according to Claim 14,
wherein during the drilling, the first platelike member is brought into a state in which the first platelike member is inclined with respect to a horizontal direction so that a tip end is located above a base end, and the second platelike member is brought into a state in which the second platelike member projects out in the projecting direction with respect to the first platelike member.

16. The flaskless mold making method according to Claim 15,
wherein the sand receiving mechanism has a first cylinder for rotating the first platelike member; and a second cylinder for driving the second platelike member so as to perform a projecting operation and a retracting operation with respect to the first platelike member.

17. A sand receiving apparatus to be provided in a mold making apparatus for making molds, or in a mold making line having a mold making apparatus for making molds, the sand receiving apparatus having:

a first platelike member provided so as to be rotatable;

a second platelike member for sand receiving provided so as to be movable in a projecting direction from a tip of the first platelike member and in a direction opposite thereto, the second platelike member being configured to receive sand produced in drilling at a position where the second platelike member projects out in the projecting direction with respect to the first platelike member while the first platelike member is located at a predetermined rotation position;

a first cylinder configured to rotate the first platelike member; and

a second cylinder configured to drive the second platelike member so as to perform a projecting operation and a retracting operation with respect to the first platelike member;

wherein before the drilling and after the drilling, the first platelike member is brought into a state in which the second platelike member is directed in a vertical direction and the second platelike member is brought into a state in which the second platelike member is retracted with respect to the first platelike member.

18. The sand receiving apparatus according to Claim 17, wherein during the drilling, the first platelike member is brought into a state in which the first platelike member is inclined with respect to a horizontal direction so that a tip end is located above a base end, and the second platelike member is brought into a state in which the second platelike member projects out in the projecting direction with respect to the first platelike member.

Drawing