PRESSING FORCE SWITCHING MECHANISM FOR ROTATION FEEDING PART OF PULVERIZER, PULVERIZER PROVIDED WITH SAME, AND PRESSING FORCE SWITCHING METHOD FOR ROTATION FEEDING PART OF PULVERIZER

Abstract

 To provide a pressing force switching mechanism for rotation feeding part of a pulverizer that makes it possible to easily extract an object to be pulverized when the object to be pulverized, such as timber, has become clogged in a pulverizing part. A pressing force switching mechanism 4 includes a feeding teeth roller 33 pressingly holding and feeding a grinding object to a grinding portion, a change point member 40 having a change point, actuatable in two directions demarcated by the change point, and having a hook pin 403 that becomes a fixed end at a lock direction side in one direction, becomes a free end at a free direction side in the other direction, and differs in position in settled states in the respective directions, a tension spring 42 hooked between an arm slab 30 and the hook pin 403 of the change point member 40, actuating the change point member 40 in the two directions, and becoming a fixed end in the actuation of the change point member 40 to the lock direction side to impart a pressing force in a bottom plate 210 direction to the feeding teeth roller 33, and a pressing force switching lever 49 acting on the change point member 40 to switch the change point member 40 between the two directions demarcated by the change point.

Description

BACKGROUND

[Field of the Invention]

[0001] The present invention relates to a pressing force switching mechanism for rotation feeding part of a pulverizer, a pulverizer including the same, and a pressing force switching method for rotation feeding part of a pulverizer. In detail, the present invention relates to arrangements with which, when a grinding object, such as a tree or the like, becomes stuck in a grinding portion, removal of the grinding object can be performed easily.

[Background Art]

[0002] In recent years, much of thinnings and other waste wood generated in felling and pruning of street trees and garden trees is used as woody biomass fuel. To manufacture the woody biomass fuel, the waste wood must be ground into chips. As an example of a pulverizer for performing grinding of waste wood, there is a tree pulverizer described in Patent Literature 1.

[0003] The conventional tree pulverizer described in Patent Literature 1 blows ground chips afar to enable recovery to be performed easily. Also, a feeding roller that is included in the tree pulverizer and pushes a grinding object against a grinding rotor while pressingly holding the object in a downward direction is arranged to be driven to rotate upon being switched arbitrarily to a direction of pushing the grinding object against the grinding rotor or an opposite direction (description in paragraph [0019] of Patent Literature 1).

[Citation List]

[Patent Literature]

[0004] Patent Literature 1: Japanese Published Unexamined Patent Application No. 2014-58044

(JP2014-58044A)

SUMMARY OF THE INVENTION

[Technical Problem]

[0005] However, the abovementioned conventional tree pulverizer has the following problems.

[0006] That is, it is described that, when work stagnates due to a grinding object becoming stuck in a vicinity of the feeding roller or the like, a work of removing the grinding object can be performed easily because the grinding rotor and rotor chamber inner walls are exposed largely when an upper cover forming the rotor chamber is opened (descriptions in paragraphs [0033] and [0034] of Patent Literature 1).

[0007] On the other hand, during grinding work by the tree pulverizer, a considerably strong holding force, that is, pressing force is required of the feeding roller to reliably feed the grinding object into the grinding rotor. Thus, even if the grinding rotor and the rotor chamber inner walls are largely exposed by opening the upper cover as described above, the removing work cannot be performed easily because the feeding roller holds the grinding object strongly. Time loss until restart of work is thus large and work efficiency is poor.

[0008] Also, if the abovementioned arrangement, that is, the arrangement of the feeding roller being rotatable in forward and reverse directions is used to perform a treatment of making the feeding roller that is holding the stuck grinding object rotate in reverse, there is a danger of the tree or the like that is the grinding object flying out to a rear of the pulverizer, which is a location where a worker performs work, and there is thus a problem in safety.

[0009] The present invention has been created in view of the above points and an object thereof is to provide a pressing force switching mechanism for rotation feeding part of a pulverizer, a pulverizer including the same, and a pressing force switching method for rotation feeding part of a pulverizer that are arranged such that, when a grinding object, such as a tree or the like, becomes stuck in a grinding portion, removal of the grinding object can be performed easily.

[Solution to Problem]

[0010] 

(1) To achieve the above object, the present invention is a pressing force switching mechanism for rotation feeding part of a pulverizer, the mechanism including a rotary feeding portion mounted to a movable body and capable of advancing and retreating in a direction of a feeding face on which a grinding object is placed and pressingly holding and feeding the grinding object to a grinding portion, a change point member having a change point in a movable direction, actuatable in two directions demarcated by the change point, and having a hooking portion that becomes a fixed end at a lock direction side in one of the two directions, becomes a free end at a free direction side in the other direction, and differs in position in settled states in the respective directions, an urging body hooked between the movable body and the hooking portion of the change point member, actuating the change point member in the two directions demarcated by the change point, and becoming a fixed end in the actuation of the change point member to the lock direction side to impart a pressing force in the feeding face direction to the feeding rotator, and a switching means acting on the change point member to switch the change point member between the two directions demarcated by the change point.
By including the rotary feeding portion mounted to the movable body and capable of advancing and retreating in the direction of the feeding face on which the grinding object is placed and pressingly holding and feeding the grinding object to the grinding portion, the rotary feeding portion pressing force switching mechanism for a pulverizer can push the rotary feeding portion against the grinding object, such as a tree or the like, and rotate the rotary feeding portion, to feed the grinding object along the feeding face to the grinding portion. The grinding object can thereby be ground continuously by the grinding portion.
By including the change point member having the change point in the movable direction, actuatable in the two directions demarcated by the change point, and having the hooking portion that becomes the fixed end at the lock direction side in one of the two directions, becomes the free end at the free direction side in the other direction, and differs in position in the settled states in the respective directions, the pressing force switching mechanism is enabled to perform clear switching of the change point member between the lock direction side and the free direction side that are demarcated by the change point.
Also, the urging body hooked between the movable body and the hooking portion of the change point member, actuating the change point member in the two directions demarcated by the change point, and becoming the fixed end in the actuation of the change point member to the lock direction side to impart the pressing force in the feeding face direction to the feeding rotator is included. Thereby, when the change point member is at the lock direction side, the hooking portion hooking the urging body becomes the fixed end, an urging force of the urging body acts sufficiently, and the pressing force of the feeding rotator in the feeding face direction is secured to enable the grinding object to be pressingly held.
Further, when the change point member is at the free direction side, the hooking portion hooking the urging body becomes the free end such that the urging force of the urging body no longer acts, the pressing force of the feeding rotator in the feeding face direction is eased, and the pressing force of pressingly holding the grinding object is also eased and weakened.
Also, the pressing force switching mechanism includes the switching means acting on the change point member to switch the change point member between the two directions demarcated by the change point, and therefore by operation of the switching means, an operation of moving the change point member to the lock direction side to make the urging body act and an operation of moving the member to the free direction side to ease the urging force of the urging body can be performed switchingly.
In addition, the term "change point" as used in the claims and the present description is used in a meaning including a point (dead point) at which when the change point member is pulled by the urging body, such as a spring or the like, it cannot be known in which of directions demarcated by the point the member would turn.

(2) The present invention may be of an arrangement where the movable body has a plurality of arm slabs with a portion being axially supported turnably and has the rotary feeding portion mounted to span across the respective arm slabs.
In this case, by turning the plurality of arm slabs, the rotary feeding portion can be made to advance and retreat in the direction of the feeding face and pushing of the rotary feeding portion against the grinding object on the feeding face and cancellation (or release) of the pushing force (pressing force) can thereby be performed.
Also, the structure is such that the rotary feeding portion is spanned across the plurality of arm slabs and therefore the rotary feeding portion serves as structural reinforcement of the movable body including the arm slabs to increase rigidity, enabling more accurate movement as the movable body even when a large load acts during work.

(3) The present invention may be of an arrangement where the switching means has a change point in a movable direction and is arranged to switch the change point member by actuation in two directions demarcated by the change point and the actuation is aided by an urging force.
In this case, for example, at an on position of the pressing force switching mechanism, the switching means, by exceeding the change point, can aid keeping of the on position by the urging force. Also, at an off position, the switching means, by exceeding the change point, can aid keeping of the off position by the urging force.

(4) To achieve the above object, the present invention is a pulverizer including a pressing force switching mechanism for rotation feeding part of a pulverizer, the pulverizer including an undercarriage, a grinding device provided on the undercarriage and grinding a grinding object, such as a tree or the like, and the pressing force switching mechanism for rotation feeding part of a pulverizer having a rotary feeding portion mounted to a movable body and capable of advancing and retreating in a direction of a feeding face on which the grinding object is placed and pressingly holding and feeding the grinding object to a grinding portion, a change point member having a change point in a movable direction, actuatable in two directions demarcated by the change point, and having a hooking portion that becomes a fixed end at a lock direction side in one of the two directions, becomes a free end at a free direction side in the other direction, and differs in position in settled states in the respective directions, an urging body hooked between the movable body and the hooking portion of the change point member, actuating the change point member in the two directions demarcated by the change point, and becoming a fixed end in the actuation of the change point member to the lock direction side to impart a pressing force in the feeding face direction to the feeding rotator, and a switching means acting on the change point member to switch the change point member between the two directions demarcated by the change point.
By the grinding device provided on the undercarriage, the pulverizer is made capable of grinding the grinding object fed to the grinding portion by the rotary feeding portion. And, if during grinding work, the grinding device (pulverizer) stops due to some cause, for example, the grinding object being too thick or the like, this can be dealt with by switching the pressing force switching mechanism from an on position, which is a set state, to an off position to ease the pressing force on the grinding object at the rotary feeding portion as described above.

(5) The present invention may be of an arrangement where the switching means has a change point in a movable direction and is arranged to switch the change point member by actuation in two directions demarcated by the change point and the actuation is aided by an urging force.
In this case, for example, at the on position of the pressing force switching mechanism, the switching means, by exceeding the change point, can aid keeping of the on position by the urging force. Also, at the off position, the switching means, by exceeding the change point, can aid keeping of the off position by the urging force.

(6) To achieve the above object, the present invention is a pressing force switching method for rotation feeding part of a pulverizer where a change point member having a change point in a movable direction is moved by a switching means to a lock direction side among two directions demarcated by the change point to make a hooking portion be a fixed end and draw a rotary feeding portion in a direction of a grinding object by an urging body hooked between the rotary feeding portion and the bridging portion, and when the grinding object becomes stuck in the grinding portion, the change point member is moved by the switching means to a free direction side among the two directions demarcated by the change point to make the hooking portion be a free end and ease an urging force by the urging body that draws the rotary feeding portion in the direction of the grinding object.
By the pressing force switching method for rotation feeding part of a pulverizer, the switching of the change point member between the lock direction side and the free direction side that are demarcated by the change point can be performed clearly by the switching means. That is, when the change point member is at the lock direction side, the hooking portion hooking the urging body becomes the fixed end, the urging force of the urging body acts sufficiently, and a pressing force of the feeding rotator in a feeding face direction is secured to enable the grinding object to be pressingly held. Also, when the change point member is at the free direction side, the hooking portion hooking the urging body becomes the free end such that the urging force of the urging body no longer acts, the pressing force of the feeding rotator in the feeding face direction is eased, and the pressing force of pressingly holding the grinding object is also eased and weakened.

(7) The present invention may be of an arrangement where the switching means has a change point in a movable direction and is arranged to switch the change point member by actuation, aided by an urging force, in two directions demarcated by the change point.
In this case, by exceeding the change point, the switching means is enabled by the urging force to aid keeping of position of the change point member that is at an on position. Also, by exceeding the change point, the switching means is enabled by the urging force to aid keeping of position of the change point member that is at an off position.

[Effects of the Invention]

[0011] The present invention can provide a pressing force switching mechanism for rotation feeding part of a pulverizer, a pulverizer including the same, and a pressing force switching method for rotation feeding part of a pulverizer that are arranged such that, when a grinding object, such as a tree or the like, becomes stuck in a grinding portion, removal of the grinding object can be performed easily.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 

Fig. 1 is a side explanatory view showing an embodiment of a pulverizer according to the present invention.

Fig. 2 is a top explanatory view of the pulverizer shown in FIG. 1.

Fig. 3 is a rear explanatory view of the pulverizer shown in FIG. 1.

Fig. 4 is a perspective explanatory view showing an embodiment of a pressing force switching mechanism for rotation feeding part according to the present invention.

Fig. 5 is an explanatory view showing a set state of the pulverizer before start of grinding work.

Fig. 6 is an explanatory view showing a state where the pulverizer is stopped due to a grinding blade biting into a tree during the grinding work on the tree.

Fig. 7 is an explanatory view showing a state where a pressing force switching lever is operated in an off position direction to cancel the set state of the pressing force switching mechanism for rotation feeding part and ease a pressing force.

Fig. 8 is an explanatory view showing a state where a pressing force release lever is operated to release the pressing force of a rotary feeding portion to take out the tree.

Fig. 9 is an explanatory view showing a state where the pressing force release lever is returned after taking out the tree.

Fig. 10 is an explanatory view showing a state where the pressing force switching lever is operated in an on position direction to begin pushing a spring hook arm in a lock direction.

DESCRIPTION OF THE (PREFERRED) EMBODIMENTS

[0013] An embodiment of the present invention shall now be described in further detail with reference to Fig. 1 to Fig. 4. In addition, in the following description, the terms "front, rear," and "right, left" may be used to express directions and locations in an easily understandable manner. Among these, "front (direction)" is the side in Fig. 1 at which a grinding device 2, to be described below, is provided, and "rear (direction)" is the side in Fig. 1 at which a handle 12, to be described below, is provided. Also, "left (direction)" is the left side in Fig. 3 and "right (direction)" is the right side in the Fig. 3.

[0014] A pulverizer A includes an undercarriage 1. The undercarriage 1 has a motor 10, a crawler 11 driven by the motor 10, and a handle 12 for driving operation. Also, on the undercarriage 1 are included a grinding device 2 that grinds a grinding object, such as a tree or the like, a feeder 3 that feeds the grinding object into the grinding device 2, and a pressing force switching mechanism 4 that switches a pressing force applied to the grinding object by the feeder 3.

[0015] The respective portions shall now be described in detail. However, the undercarriage 1, the motor 10, the crawler 11, and the handle 12 are ordinary components in a pulverizer and description thereof shall thus be limited to the simple description given above and detailed description shall be omitted.

(Grinding device 2)

[0016] The grinding device 2 has a casing 20. The casing 20 has a supply opening 200 at a grinding object supplying side (right side in Fig. 1) (see Fig. 6, etc.). A supply duct 21 of so-called bell mouth shape that is somewhat narrowed toward the supply opening 200 side is connected to the supply opening 200. An upper face of a bottom plate 210 that is a feeding face of the supply duct 21 is downwardly inclined at a required angle toward the supply opening 200.

[0017] Incidentally, the supply duct 21 shown in Fig. 1 to Fig. 3 is of Japanese specifications and although unillustrated, under European specifications, a specialized supply duct that is even longer in distance from an inlet at a work portion side to the supply opening 200 is adopted.

[0018] A partition member 22 defining a grinding space 25 at a front upper portion of the casing 20 is provided in an interior of the casing 20. Also, the casing 20 includes an upper cover 29 capable of opening and closing an upper opening portion (see Fig. 4). Performing of maintenance of a grinding rotor 23 to be described below is enabled by opening the upper cover 29.

[0019] The grinding rotor 23 is rotatably disposed in an interior of the grinding space 25. The grinding rotor 23 is axially supported such as to bridge across respective side plates 201 of the casing 20 with a direction of a rotating shaft 230 being a right-left direction and a horizontal direction. The grinding rotor 23 is belt-driven by a rotating shaft 101 of the motor 10 (see Fig. 2). In addition, a front portion of the casing 20 is opened and ground matter can be discharged through a screen 26 mounted to an opening portion (reference sign omitted).

[0020] The grinding rotor 23 has, at two locations in a circumferential direction of a rotator 231 fixed to the rotating shaft 230, grinding blades 24 extending across an entire width. Each grinding blade 24 is disposed such that a blade edge (reference sign omitted) is parallel to the rotating shaft 230. Also, a rotation direction of the grinding rotor 23 is a clockwise rotation direction in Fig. 1 and is arranged to blow the ground matter toward and against the partition member 22 below. A rear portion side (supply opening 200 side) of the grinding rotor 23 is a grinding portion that grinds the grinding object.

(Feeder 3)

[0021] The feeder 3 is disposed at an upper portion side of a rear portion of the casing 20. The feeder 3 has arm slabs 30 of substantially quadrilateral shape disposed at outer sides of the respective side plates 201. Each arm slab 30 constitutes a movable body and an upper portion at a rear portion side is axially supported by an axial rod 31 such as to enable turning in an up/down direction with respect to each side plate 201. Also, between lower portions at front portion sides of the respective arm slabs 30, a feeding teeth roller 33 that is a feeding rotator is axially supported via bearings 32 such as to be rotatably drivable (see Fig. 4).

[0022] The feeding teeth roller 33 has a structure provided with feeding teeth 331 at five locations at equal intervals in a circumferential direction of a rotating shaft 330 and intermediate portions in radial directions of the respective feeding teeth 331 are bent at the same angle in a rotation direction. Chevron-shaped teeth are formed continuously at a tooth edge of each feeding tooth 331 (see Fig. 2). The feeding teeth roller 33 is interlocked with the grinding rotor 23 via an electromagnetic clutch 35 that rotates together with the grinding rotor 23 (see Fig. 2). When the electromagnetic clutch 35 is connected, the feeding teeth roller 33 is made to rotate in a feeding direction (clockwise rotation direction in Fig. 1) via a power transmission mechanism (reference sign omitted), and when the electromagnetic clutch 35 is disconnected, the feeding teeth roller 33 is braked and stops rotating.

[0023] Also, slots 202 for passing through the rotating shaft 330 are formed in the respective side plates 201 of the casing 20. Each slot 202 is formed in an arc centered at the axial rod 31 and enables lifting and lowering movements of the feeding teeth roller 33, that is, movements in a direction of approaching and in a direction of separating from the grinding object fed to the grinding portion (see Fig. 4).

[0024] In addition, movement of the feeding teeth roller 33 is stopped by a rear end portion of each arm slab 30 contacting an adjusting bolt 380 screwed in a manner enabling advancing and retreating to the front and rear onto a bracket 38 shown in Fig. 1. The stopped position is adjustable by turning the adjusting bolt 380. Also, in the stopped state, a rotation trajectory of the tooth edge of each feeding tooth 31 of the feeding teeth roller 33 is set such as to be slightly separated from an upper face of the partition member 22 such as not to interfere with the rotation.

[0025] A stabilizer 36 is bridged across the respective arm slabs 30 and the respective arm slabs 30 are thereby coupled. The stabilizer 36 secures rigidity of a structure constituted of the respective arm slabs 30 and the feeding teeth roller 33. Also, on an upper portion rear end close to a left end of the casing 20, a pressing force release lever 37 is axially supported turnably via an axial rod 370. In addition, the pressing force release lever 37 is not urged and, in a normal state, passes below the stabilizer 36 and is tilted forward by its own weight.

(Pressing force switching mechanism 4)

[0026] The pressing force switching mechanism 4 is provided, below the arm slabs 30, on the side plates 201 at right and left sides (near side and far side in Fig. 1 and Fig. 4) of the casing 20. Of the pressing force switching mechanism 4, spring hook arms 40, tension springs 42, switching arm plates 46, etc., to be described below have symmetrical structures at the right and left sides and therefore in the following description, just the structure at the left side that is illustrated shall be described and this description shall apply to the structure at the right side for which description shall be omitted.

[0027] The pressing force switching mechanism 4 has the spring hook arm 40 that is a change point member and is axially supported turnably by an axial rod 41 on the side plate 201. A tip portion of the spring hook arm 40 is pointedly formed and inclined edges at respective sides thereof are arranged as an on contacting portion 401 and an off contacting portion 402.

[0028] A hook pin 403 that is a hooking portion is provided at an outer face side close to a tip end of the spring hook arm 40. A spring hook 34 is provided at a lower corner portion at the front portion side of the arm slab 30 and the tension spring 42 that is an urging body is hooked with a required tensile force between the spring hook 34 and the hook pin 403. Also, the spring hook arm 40 is arranged to contact and be stopped by a stopper 203, provided on the side plate 201, in an on position shown in Fig. 4. In addition, the stopper 203 is fitted with a collar (not illustrated) made of synthetic resin for cushioning.

[0029] In addition, the spring hook arm 40 has an arrangement where an urging force of the tension spring 42 acts in a direction such that it turns in either way with respect to an angle at which a centerline of the tension spring 42 overlaps with the hook pin 403 and the axial rod 41 at the same time (angle at which the tension spring 42 is extended the most) as a change point. The spring hook arm 40 and the tension spring 42 constitute a link mechanism (an irregular link mechanism in the sense that one of the links is a spring that undergoes expansion and contraction deformation). The arrangement is such that, at the on position, the spring hook arm 40 contacts the stopper 203 upon being pulled slightly in an upwardly turning direction beyond the change point and is fixed (locked) by the urging force of the tension spring 42.

[0030] An axially supporting part 43 is provided at a rear edge of the side plate 201 at the left side of the casing 20. Also, at a left side of this side plate 201, a supporting part 44 is erected, across a required interval from the side plate 201, on a base 100 of the undercarriage 1. Between an upper portion of the supporting part 44 and the axially supporting part 43, a drive shaft 45 is axially supported rotatably in a horizontal, right-left direction via bearings (reference signs omitted). And, at a portion of the drive shaft 45 close to the axially supporting part 43, a switching arm plate 46, which is of substantially L-shape and constitutes a switching means together with a pressing force switching lever 49, an adjusting member 47, a tension spring 48, etc., to be described below, is mounted by the drive shaft 45 being made to penetrate through and fixed at a bend angle portion.

[0031] The switching arm plate 46 has an on arm 461 (front side in Fig. 4) and an off arm 462 (rear side in Fig. 4) and rollers 460 that contact the spring hook arm 40 are provided at tip end portions of the respective arms. To an outer edge close to a tip portion of the off arm 462, one end portion of the substantially U-shaped adjusting member 47 is mounted via a pin 463 such as to be enable turning in the up-down direction. Also, the tension spring 48 is hooked with a required tensile force between the other end portion of the adjusting member 47 and a spring hook 480 provided at a lower end portion of the side plate 201.

[0032] The pressing force switching lever 49 is fixed to a tip end portion at an outer side of the drive shaft 45. A direction of the pressing force switching lever 49 is set to substantially overlap with a direction of projection parallel to the drive shaft 45 of the roller 460 of the off arm 462 (see Fig. 5, etc.). A change point is also set for the above-described arrangement including the drive shaft 45, switching arm plate 46, adjusting member 47, tension spring 48, and the pressing force switching lever 49.

[0033] That is, the arrangement is one where the tensile force of the tension spring 48 acts in a direction such that the switching arm plate 46 turns in either way with respect to an angle at which a centerline of the tension spring 48 overlaps with the drive shaft 45 and the pin 463 at the same time (angle at which the tension spring 48 is extended the most) as a change point. The off arm 462, the tension spring 48, and the adjusting member 47 constitute a link mechanism (an irregular link mechanism in the sense that one of the links includes a spring that undergoes expansion and contraction deformation). That is, at the on position shown in Fig. 5, the above-described arrangement surpasses the change point to urge the switching arm plate 46 in a clockwise turning direction in Fig. 5 and aid keeping of the on position.

[0034] Also, at the off position shown in Fig. 7, the on arm 461 contacts and is stopped by a stopper 204 provided on the side plate 201 and the above-described arrangement surpasses the change point in a direction opposite that in the case of the on position to urge the switching arm plate 46 in a counterclockwise turning direction in Fig. 7 and aid keeping of the off position. The spring hook arm 40 rotates beyond the change point in a direction opposite that in the case of the on position and is put in a free state limited by contacting of a stopper 205 provided on the side plate 201. In addition, the U-shape of the adjusting member 47 is a shape that provides clearance in advance at the curved portion to avoid the drive shaft 45 during movement and prevent interference (or contact).

(Actions)

[0035] Actions of the pulverizer A shall now be described with reference to Fig. 1 to Fig. 10 (mainly Fig. 5 to Fig. 10 in regard to movements of the respective portions).

(1) Before grinding work on a tree W that is the grinding object is started, the pulverizer A is set as follows. First, the pressing force switching lever 49 is at the on position, and thereby the spring hook arm 40 is set beyond the change point to the lock direction side and is stopped in contact with the stopper 203 by the urging force of the tension spring 42. Also, each arm slab 30 is turned in a downward direction by the urging force of the tension spring 42 and the feeding teeth roller 33 is thereby lowered until a feeding tooth 331 contacts the partition member 22 (see Fig. 5). In this state, a tensile force acts on the tension spring 42. Further, the electromagnetic clutch 35 is disconnected and the feeding teeth roller 33 is braked such that it does not rotate.

(2) In starting the grinding work on the tree W, the motor 10 is driven from the state shown in Fig. 5. The tree W to be ground is prepared and the electromagnetic clutch 35 is connected to make the feeding teeth roller 33 rotate in the feeding direction (clockwise rotation direction in Fig. 6). Subsequently, when the tree W is pushed in successively toward the feeding teeth roller 33, the feeding teeth 331 of the rotating feeding teeth roller 33 bite into the tree W and feed out the tree W along the upper face of the bottom plate 210 toward the supply opening 200. The tree W is thereby ground by the grinding rotor 23 that is the grinding portion. By successively adding and supplying trees W in the same manner, the grinding work can be performed continuously.
And, if, during the grinding work, a grinding blade 24 bites into the tree W due to some cause, for example, the tree W being too thick or the like, and the pulverizer A stops (see Fig. 6), or even if the stopping of the pulverizer A does not occur, if feeding to the supply opening 200 is made difficult due to spreading of the branches of the tree W supplied and obstruction by the branches and leaves or the like, this is dealt as follows.

(3) If, as in the latter of the above cases, an amount of pull of the tension spring 42 is small and the pressing force on the tree W by the feeding teeth roller 33 is not very large, first, the pressing force release lever 37 is turningly operated in a rearward direction. If, by this operation, the feeding teeth roller 33 separates from the tree W, the tree W is removed in this state. However, if the amount of pull of the tension spring 42 is large and this operation cannot be performed, the pressing force release lever 37 is returned to the original position and thereafter, the pressing force switching lever 49 is turned in the direction of the off position (forward direction).
In accompaniment with the turning by this operation, the switching arm plate 46 also turns in the same direction, the roller 460 of the off arm 462 contacts the off contacting portion 402 of the spring hook arm 40, and the spring hook arm 40 is pushed further and rotates largely beyond the change point in the direction opposite that mentioned above (see Fig. 7).
Also, at the point of surpassing the change point, the spring hook arm 40 is switched to the free direction side and the urging force of the tension spring 42 is substantially cancelled. The pressing force of the feeding teeth roller 33 on the tree W is thereby eased and weakened and the set state at the beginning of work is cancelled. In addition, by the pin 463 surpassing the change point, the switching arm plate 46 is urged in the counterclockwise turning direction in Fig. 7 to keep the off position.

(4) In the state of Fig. 7, the pressing force of the feeding teeth roller 33 is still acting on the tree W and therefore this pressing force is cancelled before removing the tree W. That is, when the pressing force release lever 37 is turningly operated in the rearward direction and a portion close to a base portion is hitched onto the stabilizer 36 to raise the feeding teeth roller 33, the spring hook arm 40 stops upon contacting the stopper 205. When the pressing force release lever 37 is then turningly operated further in the rearward direction from this state as indicated by virtual lines, the tension spring 42 is extended further and the pressing force of the feeding teeth roller 33 can be released. The tree W stuck in the grinding portion can thereby be removed simply and safely (see Fig. 8).
Thus, at the off position, the position of the hook pin 403 hooking a base end of the tension spring 42 is made close to the spring hook 34 such that the amount of pull by the tension spring 42 is made sufficiently small and operation by the pressing force release lever 37 can thus also be performed easily with a comparatively light force.

(5) When, after the tree W is taken out, the pressing force release lever 37 is turningly operated in the forward direction and returned to its original state, support of the stabilizer 36 by the pressing force release lever 37 is removed and each arm slab 30 turns in the downward direction due to its own weight and stops upon contacting the adjusting bolt 380. Also, the spring hook arm 40 turns in a downwardly returning direction in a manner of being pushed by the tension spring 42 and stops at the free direction side without reaching the change point (see Fig. 9).

(6) After the tree W is removed, the pulverizer A must be returned to the original set state shown in Fig. 5 such that the grinding work can be restarted. In this process, the pressing force switching lever 49 is operated in the direction of the on position (rearward direction) from the state shown in Fig. 9. In accompaniment with the turning by this operation, the switching arm plate 46 also turns in the same direction and the roller 460 of the on arm 461 contacts the on contacting portion 401 of the spring hook arm 40 (see Fig. 10).

[0036] When the spring hook arm 40 is pushed further by the roller 460 of the on arm 461, the spring hook arm 40 rotates beyond the change point in the lock direction and stops in a state of contacting the stopper 203. The pressing force switching mechanism 4 of the pulverizer A can thereby be returned to the original set state shown in Fig. 5, and thereafter, the grinding work can be continued generally by the procedures of (1) and (2) described above.

[0037] The terms and expressions used in the present description and the claims are merely descriptive, are by no means restrictive, and are not intended to exclude terms and expressions equivalent to features described in the present description and claims and portions thereof. Also, various modifications are obviously possible within the scope of the technical ideas of the present invention.

DESCRIPTION OF REFERENCE NUMERALS

[0038] 

A

Pulverizer

1

Undercarriage

100

Base

10

Motor

101

Rotating shaft

11

Crawler

12

Handle

2

Grinding device

20

Casing

200

Supply opening

201

Side plate

202

Slot

203

Stopper

204

Stopper

205

Stopper

21

Supply duct

210

Bottom plate

22

Partition member

23

Grinding rotor

230

Rotating shaft

231

Rotator

24

Grinding blade

25

Grinding space

26

Screen

29

Upper cover

3

Feeder

30

Arm slab

31

Axial rod

32

Bearing

33

Feeding teeth roller

330

Rotating shaft

331

Feeding tooth

34

Spring hook

35

Electromagnetic clutch

36

Stabilizer

37

Pressing force release lever

370

Axial rod

38

Bracket

380

Adjusting bolt

4

Pressing force switching mechanism

40

Spring hook arm

401

On contacting portion

402

Off contacting portion

403

Hook pin

41

Axial rod

42

Tension spring

43

Axially supporting part

44

Supporting part

45

Drive shaft

46

Switching arm plate

460

Roller

461

On arm

462

Off arm

463

Pin

47

Adjusting member

48

Tension spring

480

Spring hook

49

Pressing force switching lever

W

Tree

Claims

1. A pressing force switching mechanism for rotation feeding part of a pulverizer, the mechanism comprising:

a rotary feeding portion mounted to a movable body and capable of advancing and retreating in a direction of a feeding face on which a grinding object is placed and pressingly holding and feeding the grinding object to a grinding portion;

a change point member having a change point in a movable direction, actuatable in two directions demarcated by the change point, and having a hooking portion that becomes a fixed end at a lock direction side in one of the two directions, becomes a free end at a free direction side in the other direction, and differs in position in settled states in the respective directions;

an urging body hooked between the movable body and the hooking portion of the change point member, actuating the change point member in the two directions demarcated by the change point, and becoming a fixed end in the actuation of the change point member to the lock direction side to impart a pressing force in the feeding face direction to the feeding rotator; and

a switching means acting on the change point member to switch the change point member between the two directions demarcated by the change point.

2. The pressing force switching mechanism for rotation feeding part of a pulverizer according to claim 1, wherein the movable body has a plurality of arm slabs with a portion being axially supported turnably and has the rotary feeding portion mounted to span across the respective arm slabs.

3. The pressing force switching mechanism for rotation feeding part of a pulverizer according to claim 1 or 2, wherein the switching means has a change point in a movable direction and is arranged to switch the change point member by actuation in two directions demarcated by the change point and the actuation is aided by an urging force.

4. A pulverizer including a pressing force switching mechanism for rotation feeding part of a pulverizer, the pulverizer comprising:

an undercarriage;

a grinding device provided on the undercarriage and grinding a grinding object, such as a tree or the like; and

the pressing force switching mechanism for rotation feeding part of a pulverizer having a rotary feeding portion mounted to a movable body and capable of advancing and retreating in a direction of a feeding face on which the grinding object is placed and pressingly holding and feeding the grinding object to a grinding portion, a change point member having a change point in a movable direction, actuatable in two directions demarcated by the change point, and having a hooking portion that becomes a fixed end at a lock direction side in one of the two directions, becomes a free end at a free direction side in the other direction, and differs in position in settled states in the respective directions, an urging body hooked between the movable body and the hooking portion of the change point member, actuating the change point member in the two directions demarcated by the change point, and becoming a fixed end in the actuation of the change point member to the lock direction side to impart a pressing force in the feeding face direction to the feeding rotator, and a switching means acting on the change point member to switch the change point member between the two directions demarcated by the change point.

5. The pulverizer including a pressing force switching mechanism for rotation feeding part of a pulverizer according to claim 4,
wherein the switching means has a change point in a movable direction and is arranged to switch the change point member by actuation in two directions demarcated by the change point and the actuation is aided by an urging force.

6. A pressing force switching method for rotation feeding part of a pulverizer,
wherein a change point member having a change point in a movable direction is moved by a switching means to a lock direction side among two directions demarcated by the change point to make a hooking portion be a fixed end and draw a rotary feeding portion in a direction of a grinding object by an urging body hooked between the rotary feeding portion and the bridging portion, and when the grinding object becomes stuck in the grinding portion, the change point member is moved by the switching means to a free direction side among the two directions demarcated by the change point to make the hooking portion be a free end and ease an urging force by the urging body that draws the rotary feeding portion in the direction of the grinding object.

7. The pressing force switching method for rotation feeding part of a pulverizer according to claim 6,
wherein the switching means has a change point in a movable direction and is arranged to switch the change point member by actuation, aided by an urging force, in two directions demarcated by the change point.

Drawing