Apparatus for removal of items from a punching tool

Abstract

 There is describe an apparatus (2) for taking out work pieces (3) from a punching tool (4) in a punching machine, e.g. an eccentric press, and comprising a housing (6) which by means of an arm (7) is fastened to a stationary lower part (5) of the punching tool (4) and which comprises a reciprocating remover arm (8) with a suction cup (9) and associated drive mechanism (10), where a projecting arm (12) fastened to a movable upper part of the punching tool (4) is drivingly connected with a vertically displaceable rack (14) which preferably via gear wheel (16) and drive wheel (18) is driving connected with the remover arm (8), where the arm (12) furthermore is driving connected with an air cylinder (20) inserted between the arm (7) and arm (12) and which supplies the suction cup (9) with both vacuum and pressurised air, and where the remover arm (8) comprises and/or interacts with control means (22,24) interacting with guide surfaces (26,28) thus formed in the housing (6) that the remover arm (8) and thereby the suction cup (9) at least during the last part of the inward movement toward the work piece (3) to be taken out is moved inward/downward, and that the remover arm (8) in the beginning is moved upward/outward when it is moved out of the tool with the work piece (3) again. By means of simple technical arrangements there is hereby achieved an apparatus for use in automatic removal of work pieces, for example from a block cutting tool in an eccentric press, which makes possible to achieve a considerably reduced cycle time corresponding to 60-120 pieces per minute.

Description

[0001] The present invention relates to an apparatus for removing work pieces from a punching tool and of the kind indicated in the preamble of claim 1.

[0002] In connection with traditional eccentric presses which are so-called mechanical presses there is often used a so-called block punch tool which is a type of tool where punching of possible holes occurs simultaneously with punching of the outer contour of the work piece. In this way there may be achieved a more plane and accurate work piece as compared with punching with the use of a tool with successive punching. The use of block punch tools do, however, usually imply the drawback that the work pieces have to be removed from the tool manually, pneumatically or by robot, which for all cases means that the process is relatively slow because the press by manual removal have to be operated by double hand triggering, or in the other cases be operated via a PLC control unit. Manual removal normally gives a cycle time corresponding to about 20 pieces per minute. By pneumatic or robot removal a cycle time corresponding to about 30-40 pieces per minute is achieved.

[0003] The invention has the purpose of indicating an apparatus for removing work pieces from punching tools of the kind mentioned in the introduction and which by means of simple technical arrangements makes it possible to achieve a considerably reduced cycle time corresponding to 60-120 pieces per minute.

[0004] The apparatus according to the invention is peculiar in that a projecting arm fastened to an upper part of the punching tool is driving connected with a vertically displaceable rack which preferably via a gear wheel and a drive wheel are driving connected with the remover arm, that the arm furthermore is driving connected with an air cylinder inserted between the arms and which supplies the suction cup with both vacuum and pressurised air, and that the remover arm comprises and/or interacts with control means interacting with guide surfaces formed in the housing so that the remover arm and thereby the suction cup at least during the last part of the inward movement toward the work piece to be removed is moved inward/downward, and that the remover arm initially is moved upward/outward when it is moved out of the tool again with the work piece. By means of simple technical arrangements there is thus achieved an apparatus for use in automatic removal of work pieces from a block punch tool of an eccentric press which makes it possible to achieve a considerably reduced cycle time corresponding to 60-120 pieces per minute.

[0005] Furthermore, it is to be noted that by utilising the mechanical features of the remover apparatus according to the invention, the eccentric press can be set to continuous punching, i.e. that the eccentric press do not have to await starting signal form e.g. a PLC control unit, but may just work continually, why it is possible to achieve a very much increased capacity of 60-120 work pieces per minute.

[0006] Suitably, the apparatus according to the invention is designed so that a lower end part of said air cylinder is fastened to the arm and that the said piston rod of said air cylinder is connected with the arm, e.g. by means of an angle fitting, that the lower cavity of the air cylinder in which a vacuum is formed when the arm is moved upward is connected with a vacuum chamber formed in the rear part of the housing and that the upper cavity of the air cylinder in which pressurised air is formed when the arm is moved upwards is connected with a pressure air chamber formed in said rear part of the housing.

[0007] In order to further automate the removal of work pieces in a simple way by means of the apparatus according to the invention, this is preferably designed so that the suction cup is connected with said vacuum chamber via an air control valve activated (opened) when the suction cup is in the tool for taking a work piece and that the suction cup is connected with said pressure air chamber via an air control valve which is activated (opened) when the suction cup is moved out of the tool in order to return a work piece. In other words, the work piece removing apparatus according to the invention is self-supplying regarding vacuum as well as pressurised air for operating the suction cup, which besides is very advantageous because the work piece removing apparatus thereby in any case do not require any external power supply of electricity, pressurised air, vacuum, or hydraulics.

[0008] The apparatus according to the invention may suitably also be designed so that the said control means for the remover arm are constituted by a ball bearing suspended at the upper side of the remover arm and interacting with a horizontal section and a front downward bent section of the said guide groove of the housing, and by a ball bearing suspended in a notch uppermost in a through passage for the remover arm in the front part of the housing and which interact with a rectilinear (horizontal) top side part of the remover arm as its underside is formed like a rack engaging the drive wheel.

[0009] In order to protect the racks and drive wheels against shock actions, the apparatus according to the invention may furthermore be designed advantageously in such a way that the vertical rack is connected with the uppermost, movable arm by means of a stay bolt, a bushing and two springs.

[0010] The apparatus according to the invention is preferably designed so that the gear ratio between gear wheel and drive wheel is 1,4:1 so that the remover arm with certainty can be in time to get the work piece out of the tool before it is closed again.

[0011] In order to allow the said diving movement of the reciprocating remover arm, it may also be advantageous that the apparatus according to the invention is thus designed in that a middle gear wheel of the said gear wheel and said drive wheel engaging said rack at the underside of the remover arm are suspended on a common shaft by means of a fork supported by springs.

[0012] The invention is explained in more detail below with reference to the drawing, on which:

Fig. 1

shows a partly sectional view from above of an embodiment of an apparatus according to the invention,

Fig. 2

shows a section on the line II-II in the apparatus according to the invention in Fig. 1,

Fig. 3

shows a partly sectional side view of the apparatus according to the invention in Fig. 1,

Fig. 4

shows a section on the line IV-IV in the apparatus shown in Fig. 1,

Fig. 5

shows a rear perspective view of the embodiment shown in Figs. 1-4 of an apparatus according to the invention,

Fig. 6

is a front perspective view of the embodiment shown in Figs. 1-4 of an apparatus according to the invention,

Fig. 7

shows a perspective view of a block punch tool for an eccentric press,

Fig. 8

shows a rear perspective view of the apparatus according to the invention mounted in the block punch tool shown in Fig. 7,

Fig. 9

shows a front perspective view of the apparatus according to the invention mounted in the block punch tool shown in Fig. 7,

Fig. 10

shows a plane view of the apparatus according to the invention mounted in a block punch tool for an eccentric press, and

Fig. 11

shows a partly sectional side view on the line XI-XI in Fig. 10 of the apparatus according to the invention mounted in a block punch tool for an eccentric press.

[0013] The shown work piece removal apparatus 2 comprises a two-piece housing 6 which by means of an arm 7 is arranged to be fastened to a stationary tool part 5 of a punching tool 4 (Fig. 8), e.g. a so-called block punch tool, where the outer contour of the work piece and possible holes and internal notches are punched simultaneously. A second arm 12 is fastened to the movable tool part, i.e. the arm 12 is moved up and down together with the movable tool part. Via a stay bolt 38, a bushing 39, and springs 40, the arm 12 is connected in a shock-absorbing way with a vertically displaceable rack 14 (Fig. 2) which via a gear wheel 16, an intermediate wheel 41 and a drive wheel 18 are driving connected with a horizontally displaceable remover arm 8 with a suction cup 9 arranged to be inserted into the open tool for successive removal of work pieces 3.

[0014] The remover arm 8 is mounted in a through passage 37 in a front part of the housing 6 in such a way that the remover arm 8 during the last part of the inserting movement into the tool has a diving movement as an upper ball bearing 22 suspended at the upper side of the remover arm 8 both interacts with a rectilinear (horizontal) wall part 26 of the passage 37 and with a front downward bent wall part 28 of the passage 37. The remover arm 8 is kept pressed against the top side of the passage 37 by means of the drive wheel 18 which engages a rack 35 formed at the underside of the remover arm 8 and which is pressed flexibly against this by means of a resilient fork 43 and compression springs 44 (Fig. 4).

[0015] On top of the lower arm 7 there is arranged an air cylinder 20, the piston rod 19 of which by means of a fitting 30 is connected with the upper arm 12, i.e. the air cylinder 20 is mounted in parallel with the vertical rack 14. The lower cavity under the piston of the air cylinder 20 in which vacuum is created when the piston rod 19 is moved upwards is connected in a way not shown with a vacuum chamber 32 formed in a rear part of the housing 6, while the upper cavity over the piston of the air cylinder in which there is formed pressurised air when the piston rod 19 is moved upwards is connected in a not shown way with a pressure air chamber 34 formed in the rear part of the housing 6, i.e. that vacuum is accumulated in the vacuum chamber 32 and pressurised air is accumulated in the pressurised air chamber 34.

[0016] The suction cup 9 is connected in a not shown way with the vacuum chamber 32 via an upper air control valve 27 arranged to be activated (opens) when the suction cup 9 has been inserted into the tool to take a work piece 3, and correspondingly the suction cup 9 is connected with the pressure air chamber 34 via a lower air control valve arranged to be activated (opens) when the suction cup 9 has been moved out of the tool to return a work piece 3. In other words, the work piece removing apparatus according to the invention is self supplying both with vacuum and pressurised air for operating the suction cup 9.

Claims

1. An apparatus (2) for removing work pieces (3) from a punching tool (4) in a punching machine, e.g. an eccentric press, and comprising a housing (6) which by means of an arm (7) is fastened to a stationary lower part (5) of the punching tool (4) and which comprises a reciprocating remover arm (8) with a suction cup (9) and associated drive mechanism (10), characterised in that an arm (12) fastened to a movable upper part of the punching tool (4) is driving connected with a vertically displaceable rack (14) which preferably via gear wheels (16) and drive wheels (18) are driving connected with the remover arm (8), that the arm (12) furthermore is driving connected with a piston rod (19) of an air cylinder (20) inserted between the arms (12) and which supplies the suction cup (9) with both vacuum and pressurised air, and that the remover arm (8) comprises and/or interacts with control means (22,24) interacting with guide surfaces (26,28) formed in the housing (6) so that the remover arm (8) and thereby the suction cup (9) at least during the last part of the inward movement toward the work piece (3) to be removed is moved inward/downward, and that the remover arm (8) initially is moved upward/outward when it is moved out of the tool again with the work piece (3).

2. An apparatus (2) according to claim 1, characterised in that a lower end part of said air cylinder (20) is fastened to the arm (7) and that the said piston rod (19) of said air cylinder (20) is connected with the arm (12), e.g. by means of an angle fitting (30), that the lower cavity of the air cylinder (20) in which a vacuum is formed when the arm (12) is moved upward is connected with a vacuum chamber (32) formed in the rear part of the housing (6) and that the upper cavity of the air cylinder (20) in which pressurised air is formed when the arm (12) is moved upwards is connected with a pressure air chamber (34) formed in the said rear part of the housing (6).

3. An apparatus (2) according to claim 1 and 2, characterised in that the suction cup (9) is connected with said vacuum chamber (32) via an air control valve (27) activated (opened) when the suction cup (9) is in the tool for taking a work piece (3) and that the suction cup (9) is connected with said pressure air chamber (34) via an air control valve (29) which is activated (opened) when the suction cup (9) is moved out of the tool in order to return a work piece (3).

4. An apparatus (2) according to claim 1 - 3, characterised in that said control means for the remover arm (8) are constituted by a ball bearing (22) suspended at the upper side of the remover arm (8) and interacting with a horizontal section (26) and a front downward bent section (28) of the said guide surfaces of the housing (6), and by a ball bearing (24) suspended in a notch (36) uppermost in a through passage (37) for the remover arm (8) in the front part of the housing (6) and which interact with a rectilinear (horizontal) top side part of the remover arm (8) as its underside is formed like a rack (35) engaging the drive wheel (18).

5. An apparatus (2) according to claim 1 - 3, characterised in that the vertical rack (14) is connected with the uppermost, movable arm (12) by means of a stay bolt (38), a bushing (39), and two springs (40).

6. An apparatus (2) according to claim 1 - 3, characterised in that the ratio between the gear wheel (16) and drive wheel (18) is 1,4:1 so that the remover arm (8) with certainty can be in time to get the work piece out of the tool before it is closed again.

7. An apparatus (2) according to claim 1 - 4, characterised in that a middle gear wheel (41) of the said gear wheel (16) and said drive wheel (18) engaging said rack (35) at the underside of the remover arm (8) are suspended on a common shaft (42) by means of a fork (43) supported by springs (44) so that the diving movement of the reciprocating remover arm (8) is allowed.

Drawing