JP5017171B2 - Tillage equipment - Google Patents

Description

  The present invention relates to a tilling device in which a rear cover that covers the rear of a tilling portion is biased in a grounding direction by a gas spring.

  Conventionally, a plurality of tilling claws are attached to a nail shaft having a left and right axis, and a plowing portion is provided on the lower side of the machine frame for cultivating soil with the tilling nail by rotating the nail shaft around the left and right axes. The rear cover is provided with a rear cover that covers the rear of the tillage part, and the rear cover is inclined to move downward as it goes rearward in a work posture for leveling the soil cultivated by the tillage part, and its front upper end side is a machine. It is supported on the frame side so as to be pivotable around the axis in the left-right direction and can swing up and down. In this working position, the rear cover is attached to the lower side to ground the rear lower end side of the rear cover. There is a tillage device in which a gas spring is provided over the machine frame side and the rear cover side. (See Patent Document 1).

  When the rear cover is in a working posture, the gas spring is inclined so as to move downward as it goes rearward, and the piston rod protrudes rearward and obliquely downward from the tube. The mounting portion on the bottom side of the tube is pivotally connected to the machine frame side bracket provided on the machine frame side on the front upper side of the rotation support shaft of the rear cover, and the mounting portion on the piston rod tip side is the rear part It is pivotally connected to the rear cover side bracket provided on the cover, and the gas spring pivot point and the gas spring mounting part on the same side as the pivot point are located at the same position in the length direction of the gas spring. (The pivot point on one end side of the gas spring and the mounting portion of the gas spring on the same side as the pivot point on the one end side coincide with each other in the length direction of the gas spring, And the pivot point at the other end of the scan the spring, and a mounting portion of the gas spring on the same side as the pivot point of the other end side are matched with respect to the length direction of the gas spring).

Further, the piston rod of the gas spring moves out and with respect to the tube when the rear cover moves up and down.
JP 2007-151503 A

In the conventional tillage device, when the rear cover is raised, the piston rod contracts. Therefore, if the highest position of the rear cover is set too high, the piston is placed in the tube at the highest position of the rear cover. It may touch the bottom end.
In view of the above problems, an object of the present invention is to provide a tillage device that can take the highest position of the rear cover.

The technical means taken by the present invention in order to solve the technical problem is provided with a rear cover that covers the rear of the tillage part provided at the lower part of the machine frame, and the rear cover is made to swing up and down. A front end side of the rear cover is supported on the machine frame side so as to be rotatable about the left and right axis, a tube filled with compressed gas , a piston provided in the tube so as to be axially movable, and a piston formed on the piston. In addition, a gas spring having an orifice for communicating the chamber on the rod side and the chamber on the bottom side of the tube and a piston rod that moves together with the piston is provided, and the rear cover is biased downward by the gas spring. As described above, one end side of the gas spring (one of the bottom side of the tube or the tip side of the piston rod) is pivotally supported by a machine frame side bracket provided on the machine frame side, and a gas spring is provided. In tilling apparatus is pivotally supported other end side of the grayed (the other side of the front end side of the bottom side or the piston rod tube) to the rear cover side bracket provided on the rear cover,
The pivot point of the tube side of the gas spring, one end of which is pivotally supported than the bottom end of the tube is positioned inward in the length direction of the gas spring Rubeku, the machine frame side bracket or the rear cover side bracket link by attaching the attaching portion of the bottom side of the tube to the other end of the Rutotomoni the link provided with a feature that it has a rotatable tube side of the gas spring to the pivot point about said one end of the link To do.

In addition, a lowering device may be provided that extends over the machine frame side bracket and the rear cover side bracket and biases the rear cover downward by a spring .
In addition, the gas spring may be disposed below the lowering device and above the pivot shaft that supports the rear cover so as to be swingable up and down .

  According to the present invention, the pivot point on one end side or the other end side of the gas spring is positioned on the inner side in the length direction of the gas spring with respect to the mounting portion of the gas spring on the same side as the pivot point. The mounting part on the one end side or the other end side of the gas spring moves away from the longitudinal direction of the gas spring from the pivot point on the same side as the mounting part, and the highest position of the rear cover is set high. Is possible.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 2, reference numeral 1 denotes a cultivator that is detachably attached to a rear portion of a vehicle such as a tractor via a connecting device such as a three-point link mechanism and that can be lifted and lowered to move the field while moving.
The tillage device 1 mainly includes a machine frame 2 connected to a three-point link mechanism, a tiller unit 3 provided on the lower side of the machine frame 2, and a tiller cover 4 that covers the tiller unit 3. Yes.

The machine frame 2 has support arms 6 projecting from the gear case 5 at the center in the left-right direction on both the left and right sides, and the upper part of the transmission case 7 is attached to the outer end side of the left support arm 6 and An upper portion of a side frame (not shown) is attached to the end side to form a rear portal structure.
The lower side of a top mast 8 projecting upward from the gear case 5 is fixed to the left and right sides of the gear case 5 of the machine frame 2, and an upper bracket 9 projecting obliquely upward and forward is attached to the top mast 8. On the upper end side of the upper bracket 9, there is provided an upper connecting pin 10 with which an upper engaging portion of a connecting frame provided on the rear end side of the three-point link mechanism is engaged from below. A lower bracket 11 is fixed to each support arm 6, and each lower bracket 11 is provided with a lower connecting pin 12 to which a connecting device below the connecting frame is connected.

The upper connection pin 10 is directly connected to the work machine side connection part of the top link of the three-point link mechanism, and the lower connection pin 12 is directly connected to the work machine side connection part of the lower link of the three-point link mechanism. It may be what you did.
The lower link is connected via a lift rod to a lift arm that is moved up and down by a hydraulic device provided at the rear of the tractor. The tiller 1 is swung up and down by swinging the lower link up and down by the hydraulic device. It can be moved up and down.

The hydraulic device is composed of a single-acting hydraulic cylinder, and the tiller 1 is raised by hydraulic pressure and lowered by its own weight.
The left and right lower brackets 11 are pivotally supported at the front end side of a support frame 13 projecting rearward from the machine frame 2, and a gauge ring 14 is attached to the rear end side of the support frame 13. A height adjusting device 15 that adjusts the height of the gauge wheel 14 by swinging the support frame 13 up and down is provided between the middle part 13 and the top mast 8.

The tillage unit 3 includes a claw shaft 16 that is rotatably mounted around a shaft center in the left-right direction between the transmission case 7 and the lower portion of the side frame, and a plurality of tilling claws 17 attached to the claw shaft 16 in the left-right direction. And.
The gear case 5 of the machine frame 2 is provided with a PIC shaft 18 that projects power from the PTO shaft of the tractor via the transmission shaft so as to protrude forward, and is input from the PIC shaft 18 to the power transmission mechanism in the gear case 5. The transmitted power is transmitted to the claw shaft 16 through the transmission shaft in the left support arm 6 and the power transmission mechanism in the transmission case 7, and the claw shaft 16 is configured to be rotationally driven in the direction of arrow A in FIG. ing.

The tillage cover 4 includes an upper cover 19 that covers the top of the tillage unit 3, a rear cover 20 that covers the rear of the tillage unit 3, and left and right side covers 21 that cover the left and right sides of the tillage unit 3. .
Each of the left and right side covers 21 has a front cover part 22 that covers the upper side of the tillage part 3 and a rear cover part 20 that covers the side part between the tillage part 3 and the rear cover 20. The part 22 is divided into upper and lower parts.

The upper front cover portion 22 is fixed to the inner side of the transmission case 7 and the side frame in the left-right direction, and the lower front cover portion 22 is fixed to the upper front cover portion 22.
The upper cover 19 is disposed between the upper front cover portions 22, and the left and right end portions are fixed to the upper front cover portion 22.
As shown in FIGS. 1 and 2, the rear cover 20 is inclined so that the rear lower end side touches the field and the soil cultivated by the cultivating unit 3 is leveled so that the rear cover 20 moves downward as it goes rearward. The pivot portion 24 provided on the front upper end side is pivotally supported on the pivot shaft 25 supported on the rear end side of the upper cover 19 so as to be rotatable about the left and right axis, and the rear portion The cover 20 is supported by the upper cover 19 (machine frame 2 side) so as to be able to swing up and down so that the rear side can move up and down.

The rear cover 20 may be provided with a detachable leveling cover on the lower end side thereafter.
The tilling device 1 according to the present embodiment is shown in FIGS. 1 to 8 as an urging means for urging the rear cover 20 in the grounding direction so as to level the soil leveled by the rear cover 20. 26 and a gas spring 27.

The abutment device 26 and the gas spring 27 are arranged on the upper side of the rear cover 20 and are juxtaposed in the left-right direction, and are distributed from the center in the left-right direction of the machine frame 2 to the left and right. (One set of urging means is provided by one lowering device 26 and one gas spring 27).
In this embodiment, the gas spring 27 is disposed on the outer side in the left-right direction of the lowering device 26 and below the lowering device 26.

As shown in FIGS. 1 and 6, the lowering device 26 includes a lowering rod 28 formed of a pipe provided over the machine frame 2 side and the rear cover 20 side, and is fitted onto the lowering rod 28. And a coil spring 29 for urging the rear cover 20.
The lower rod 28 is disposed above the rear cover 20 and is disposed so as to extend rearward in a state where the rear cover 20 is in the working posture, and the front end side thereof is the rear upper surface side of the upper cover 19. It is pivotally supported by a bracket 30 erected on the end side (this is referred to as a machine frame side bracket), and the rear side of the lowering rod 28 is inserted through a rod holder 32, and the rod holder 32 is connected to the rear cover 20. Is provided on a bracket 31 (referred to as a rear cover side bracket) erected on the center side in the front-rear direction of the upper surface (back surface).

The machine frame side bracket 30 may be fixed to the support arm 6 as long as it is provided on the machine frame 2 or a member fixed to the machine frame 2.
As shown in FIG. 5, the machine frame side bracket 30 is formed in an open U-shape rearward from the left and right side walls 30a and the front wall 30b connecting the front end sides of the left and right side walls 30a. The front end side of the lowering rod 28 is inserted in the upper part between the side walls 30a, and the front end side of the lowering rod 28 is pivotally attached to the left and right side walls 30a via a pivot 33 so as to be rotatable around a horizontal axis. Thus, the lowering rod 28 can swing up and down around the pivot 33.

  As shown in FIG. 5, the rear cover side bracket 31 has a pair of left and right side plates 31a connected in the middle in the vertical direction, and the rod holder 32 is disposed above the left and right side plates 31a. 32, the shaft portions 34 provided on both the left and right sides are fitted to the support holes 35 formed in the left and right side plates 31 a so as to be rotatable around the axis in the left-right direction, whereby the rear cover-side bracket 31 is attached. It is supported rotatably.

Further, the rod holder 32 is formed with an insertion hole 36 extending in a direction perpendicular to the axis of the support hole 35 (shaft portion 34) from the front surface to the rear surface.
Is inserted, and the rod holder 32 and the lowering rod 28 are relatively movable in the axial direction of the lowering rod 28.
The coil spring 29 is disposed on the front side of the rod holder 32, and a spring receiving member 37 is provided on the front side of the coil spring 29.

The spring receiving member 37 includes a key 39 that is engaged with a locking groove 38 formed on the surface side of the lowering rod 28, and a spring that urges the key 39 to engage with the locking groove 38. The spring receiving member 37 is positioned with respect to the lowering rod 28 by engaging the key 39 with the locking groove 38.
Further, a large number of locking grooves 38 are formed at intervals in the axial direction of the lower rod 28, and the key 39 is spring-loaded by rotating the spring receiving member 37 around the axis of the lower rod 28. The key 39 can be detached from the locking groove 38 against the urging force of the spring member 40 and engaged with another locking groove 38 against the urging force of the receiving member 37. By combining them, the position of the spring receiving member 37 with respect to the lowering rod 28 can be changed (the spring receiving member 37 can be positioned at a plurality of positions in the axial direction of the lowering rod 28).

  Then, when the rear cover 20 is in a working posture, the coil spring 29 is compressed between the spring receiving member 37 and the rod holder 32, whereby a biasing force that biases the rear cover 20 downward acts on the rear cover 20. To do. Further, the biasing force on the rear cover 20 can be changed by changing the position of the spring receiving member 37 in a state where the coil spring 29 is compressed between the spring receiving member 37 and the rod holder 32.

The biasing force of the coil spring 29 is applied to the rear cover by engaging the spring receiving member 37 with the locking groove 38 at the front end or by disengaging the key 39 of the spring receiving member 37 with the locking groove 38. 20 is set to a free state.
Further, a contact 41 that restricts the downward swing of the rear cover 20 by contacting the rear surface side of the rod holder 32 is provided on the rear end side of the lowering rod 28.

  The rod holder 32 is provided with a lock pin (not shown) that is inserted into a lock hole 42 formed in the lowering rod 28 to restrict relative movement between the rod holder 32 and the lowering rod 28. A switching lever 43 that switches the position of the lock pin between a lock position for inserting the lock pin into the lock hole 42 and a non-lock position for removing the lock pin from the lock hole 42 is provided.

The switching lever 43 is provided on the upper end side of the rod holder 32 so as to be rotatable about the axis in the left-right direction. As shown in FIG. The lock pin is held at a position where it is removed from the lock hole 42 by the biasing force of the spring, and the lock pin can be inserted into the lock hole 42 by the biasing force of the spring by raising the switching lever 43.
Further, when the rear cover 20 is in the working posture, the lock pin is in a position disengaged rearward from the lock hole 42. When the switching lever 43 is raised when the lock pin is in this position, the lock pin is moved by the biasing force of the spring. When the rear cover 20 is lifted upward from the working posture, the rod holder 32 moves forward relative to the lower rod 28 and the lock pin is locked. When matched with the hole 42, the lock pin is automatically inserted into the lock hole 42 by the biasing force of the spring to restrict the relative movement between the lowering rod 28 and the rod holder 32, and the rear cover 20 is moved upward from the working posture. It is configured to be held in a raised position.

  As shown in FIG. 3, the gas spring 27 includes a tube 46, a piston 47 provided in the tube 46 so as to be axially movable, and a piston rod 48 that moves integrally with the piston 47, The inside of the tube 46 is divided into a rod-side chamber 46A and a bottom-side chamber 46B by a piston 47, and the rod-side chamber 46A and the bottom-side chamber 46B in the tube 46 communicate with each other by an orifice 49 formed in the piston 47. The tube 46 is filled with compressed gas.

Since the rod-side pressure receiving surface of the piston 47 has a smaller area for receiving the compressed gas sealed in the tube 46 than the bottom-side pressure receiving surface, the piston rod 48 always repels in the extending direction by the difference in the pressure receiving area. I have power.
The gas spring 27 may have another structure (for example, oil in the tube 46), and the piston rod 48 is urged in the extending direction by the compressed gas. That's fine.

Ball joints 53 and 54 (joint members) provided with mounting portions 51 and 52 (fixing tools) and ball joint portions 50A and 50B on the bottom end side of the tube 46 of the gas spring 27 and the tip end side of the piston rod 48, respectively. ).
As shown in FIGS. 1 to 5, when the rear cover 20 is in the working posture, the gas spring 27 is extended toward the rear side (an inclined state or a substantially horizontal state close to the horizontal), and the gas spring 27 The spring 27 is arranged in parallel with the rear cover 20 in the vertical direction.

In the present embodiment, the gas spring 27 is arranged so that the tube 46 is positioned on the front side, and the piston rod 48 protrudes rearward and rearward.
On the side wall 30a on the outer side in the left-right direction of the machine frame side bracket 30, a support cylinder 64 positioned on the lower side of the pivot 33 is provided so as to protrude outward in the left-right direction.

  The support cylinder 64 has a horizontal axis, and a pivot shaft 66 fixed to one end side (rear end side) of a link 65 made of a plate is inserted into the support cylinder 64 so as to be rotatable around the axis. The pivot shaft 66 is prevented from coming off through the machine frame side bracket 30, and the rear end side of the link 65 is connected to the machine frame side bracket 30 and the support cylinder 64 via the pivot shaft 66. Is supported so as to be rotatable about the axis of the shaft.

Further, a mounting portion 51 of a ball joint 53 on the bottom side of the tube 46 is fixedly attached to the other end side (front end side) of the link 65, and the front end side of the tube 46 is connected to the front end side of the link 65 in the left-right direction. It is attached so as to be rotatable around the axis.
The tube 46 of the gas spring 27 rotates around the axis of the pivot shaft 66 together with the link 65, and the axis of the pivot shaft 66 is the pivot point X (on the tube 46 side of the gas spring 27). As shown in FIG. 4, the pivot point X on the tube 46 side of the gas spring 27 is a ball joint on the tube bottom side of the gas spring 27. The gas spring 27 is located on the inner side in the length direction of the mounting portion 51 of 53.

  1 to 5, the pivot point X on the tube 46 side of the gas spring 27 is located on the inner side in the length direction of the gas spring 27 with respect to the bottom side end portion 46 </ b> C of the tube 46. (In other words, the pivot point X on the tube 46 side of the gas spring 27 is between the bottom side end portion 46C of the tube 46 and the piston rod side end portion 46C, and between the bottom side end portion 46C of the tube 46 and the piston rod side. It is located closer to the bottom end 46C from the center between the ends 46bC).

  The inner side in the length direction of the gas spring 27 refers to a direction from the attachment portions 51 and 52 on one end side toward the attachment portions 51 and 52 on the other end side of the gas spring 27 on one end side of the gas spring 27. On the other end side of the gas spring 27, the direction from the mounting portions 51, 52 on the other end side toward the mounting portions 51, 52 on one end side of the gas spring (for example, on the bottom side of the tube 46 of the gas spring 27). , The direction from the bottom mounting portion 51 of the tube 46 toward the mounting portion 52 on the front end side of the piston rod 48 of the gas spring 27, and on the front end side of the piston rod 48 of the gas spring 27, (Refers to the direction from the mounting portion 52 toward the mounting portion 51 on the bottom side of the tube 46 of the gas spring).

Further, the outside in the length direction of the gas spring 27 refers to the direction opposite to the inside in the length direction of the gas spring 27.
The tube 46 of the gas spring 27 is located above the pivot portion 24 of the rear cover 20, and the pivot point X on the tube 46 side of the gas spring 27 is located above the front side of the pivot shaft 25 of the rear cover 20. ing.

A pivot shaft 66 may be provided directly on the tube 46 so that the tube 46 is pivotally supported directly on the machine frame side bracket 30 (or a member fixed to the machine frame side bracket 30) without using the link 65. .
The front end side of the piston rod 48 of the gas spring 27 (the rear end side of the gas spring 27) is pivotally connected to a lever 57 provided on the rear cover side bracket 31 so as to be rotatable about a left and right axis. The front end side of the piston rod 48 of the gas spring 27 is pivotally supported by the rear cover side bracket 31 via the.

The lever 57 has a base end side (one end side) that is pivotable about a left and right axis around a lever support portion 58 formed of a plate fixed to a side plate 31a on the outer side in the left and right direction of the rear cover side bracket 31. The mounting portion 52 of the ball joint 54 on the tip end side of the piston rod 48 of the gas spring 27 is fixedly attached to the tip end side (the other end side) of the operation lever.
A cylindrical member 59 is fixed to the base end side of the lever 57 and an insertion hole 60 communicating with the cylindrical member 59 is formed. A pin 61 is fixed to the lever support portion 58 so as to protrude in the left-right direction. The cylindrical member 59 is externally fitted to 61 so as to be rotatable about the axis, and the pin 61 is protruded from the insertion hole 60 and a retaining member 62 is attached to the tip end side of the pin 61, whereby the lever 57 is moved to the lever. The support portion 58 is rotatably supported.

In the above configuration, the link 65 may be provided on the rear cover side bracket 31, and the lever support portion 58 and the lever 57 may be provided on the machine frame side bracket 30, and the gas spring 27 may be reversed.
Further, the link 65 is pivotally supported on one of the machine frame side bracket 30 or the rear cover side bracket 31, and the attachment portion 52 of the ball joint 54 on the tip end side of the piston rod 48 is connected to the link 65 and the bottom side of the tube 46 is connected. The mounting portion 51 of the ball joint 53 may be attached to the other of the machine frame side bracket 30 or the rear cover side bracket 31, and the pivot point on one end side or the other end side of the gas spring 27 is on the same side as the pivot point. It is only necessary that the gas spring 27 is displaced inward in the longitudinal direction of the gas spring 27 with respect to the mounting portions 51 and 52 of the gas spring 27.

  When the rear cover 20 is in the working posture, as shown in FIG. 3, the pivot point Y (the pivot center of the ball joint 54 and the pivot point of the gas spring 27 on the piston rod 48 side) is at the tip end side of the piston rod 48. When the gas spring 27 is positioned below the deadline L (dead point) passing through the pivot point X on the tube 46 side of the gas spring 27 and the pivot point Z of the lever 57 (rotation center of the lever 57). The gas spring 27 urges the lever 57 in a direction to swing the lever 57 downward, and the lever 57 is provided by a stopper 63 provided on the rear cover side bracket 31 (or provided on the lever support portion 58). The downward rotation is restricted, and in this state (biased state), the biasing force of the gas spring 27 is the lever 57, the stopper 63 and the rear cover. It acts so as to swing the rear cover 20 to the lower side (ground direction) via the over-side bracket 31.

  Further, as shown in FIG. 3, the lever 57 is rotated upward from the operating position W where the urging force of the gas spring 27 acts to swing the rear cover 20 downward. If the pivot point Y on the other end side of the gas spring 27 is positioned above the deadline L beyond the deadline L, the urging force of the gas spring 27 acts in a direction to rotate the lever 57 rearward, and the gas spring 27 Is in a fully extended state, and the urging force of the gas spring 27 is in a free state where it does not act on the rear cover 20.

Therefore, the lever 57 is turned (switched) so that the urging force of the gas spring 27 acts on the rear cover 20 and the urging force of the gas spring 27 does not act on the rear cover 20. The state of the spring 27 can be easily switched.
Further, a plurality of mounting holes 67 for mounting the mounting portion 52 of the ball joint 54 on the front end side of the piston rod 48 are provided on the front end side of the lever 57 (in the present embodiment, there are three, but two or four or more). It may be provided), and the urging force with respect to the rear cover 20 of the gas spring 27 can be changed by making the pivot position of the end of the gas spring 27 changeable.

As shown in FIG. 7, in the biased state, the biasing force of the gas spring 27 is the rear cover 2.
It acts in the direction of swinging the rear cover 20 downward in the entire range of 0 vertical swing, and as shown in FIG. 8, the biasing force of the gas spring 27 causes the vertical swing of the rear cover 20 in the free state. It does not act on the rear cover 20 throughout the range.
In the embodiment, the gas spring 27 is biased and the urging force of the lowering device 26 is not applied to the rear cover 20 so that the rear cover 20 is urged in the grounding direction only by the urging force of the gas spring 27. In addition, the gas spring 27 is in a free state and the urging force of the lowering device 26 is applied to the rear cover 20 to urge the rear cover 20 in the grounding direction only by the urging force of the lowering device 26. In addition, the urging force of the gas spring 27 and the lowering device 26 may be applied to the rear cover 20 or may not be applied together.

  Further, when the rear cover 20 is urged only by the lowering device 26, the difference in the urging force of the lowering device 26 is large depending on the vertical position of the rear cover 20, and the operating range of the urging force is narrow. However, if the rear cover 20 is biased only by the biasing force of the gas spring 27, the biasing force with respect to the rear cover 20 is made substantially uniform. In addition, the range of action in which the rear cover 20 can be urged can be expanded without adjusting the urging force.

  Further, in the gas spring 27, when the gas spring 27 is contracted, the pressure inside the tube 46 is increased by the piston rod intrusion integral. However, in this embodiment, the gas spring 27 is in a horizontal state when the rear cover 20 is in the working posture. Therefore, even if the rear cover 20 swings up and down in the working posture, the length of the gas spring 27 does not change so much and the urging force of the gas spring 27 does not change so much. Yes.

  Further, in the biased state, the gas spring 27 contracts as the rear cover 20 rises, and at the highest position of the rear cover 20, the gas spring 27 extends rearward and obliquely rearward. As shown in FIG. 3, the joint on the tube 46 side of the gas spring 27 is pivotally connected to the machine frame side bracket 30, and the joint on the tip end side of the piston rod 48 of the gas spring 27 is pivotally connected to the rear cover side bracket 31. In this case, depending on the highest position of the rear cover 20, the gas spring 27 may reach a contraction limit (the length of the gas spring 27 is the shortest), and the piston 47 may contact the end in the tube 46. In the embodiment, the pivot point X on the tube 46 side of the gas spring 27 is set to be closer to the gas spring than the mounting portion 51 on the tube bottom side of the gas spring 27. Since the gas spring 27 is displaced inward in the vertical direction, the attachment portion 51 on the tube bottom side of the gas spring 27 moves away from the pivot point X on the tube 46 side of the gas spring 27 to the outer side in the length direction of the gas spring 27. In other words, the piston 47 is prevented from coming into contact with the end of the tube 46 at the highest position of the rear cover 20 (the length of the gas spring 27 is minimized), or the rear cover 20 is highest. The position can be taken high.

  Further, in the configuration shown in FIG. 15, the pivot point (attachment part) on the tube 46 side of the gas spring 27 is moved in the length direction (axial direction) from the position shown in FIG. ) If the position is changed to the lower side, the gap between the piston 47 and the bottom end in the tube 46 at the highest position increases, and the gas spring 27 does not become the shortest at the highest position of the rear cover. In this case, the tube 46 comes into contact with the rear end side of the rear cover 20 or the upper cover 19 at the lowest position of the rear cover 20, but this is the case with the above embodiment. Nor.

  In the configuration shown in FIG. 15, when the rear cover 20 is set to the highest position, there is a problem if the urging force of the rear cover 20 by the gas spring 27 can be released as in this embodiment. However, if you forget to release the urging force of the rear cover 20 by the gas spring 27, or if the rear cover 20 is caught in the cage during the tilling operation, the rear cover 20 There is a possibility that it will be in the raised position.

Further, some tractors are provided with a tilling device that controls the tilling depth by raising and lowering the tilling device 1 based on the vertical swing amount of the rear cover 20. In this case, when the rear cover 20 is pushed up by the soil plowed by the tillage unit 3 or stones in the field, the gas is applied so as to give an opposite resistance against the compression of the coil spring 29 of the lowering device 26. By acting on the spring 27, the compression of the coil spring 29 can be slowed, and when the rear cover 20 returns (lowers), the resistance against the return (restoration) of the coil spring 29 of the lowering device 26 is opposite. The return of the coil spring 29 can be delayed by applying the gas spring 27 so as to provide the above.

  As a result, when the rear cover 20 moves up due to the pressure of the soil, stones, or the like, the gas spring 27 suppresses the speed and amplitude of the rear cover 20 from moving upward, and the rear cover 20 When moving, the gas spring 27 functions to suppress the downward movement speed and amplitude of the rear cover 20 to attenuate the vertical movement of the rear cover 20 and to suppress the number of continuous swings of the rear cover 20. it can.

That is, compared with the case where the rear cover 20 is urged only by the lowering device 26, when the lowering device 26 and the gas spring 27 are used together, the vertical swing motion of the rear cover 20 is slowed down during plowing. In the case where the vertical movement of the rear cover 20 is detected and plowing depth control is performed, an excessive response is prevented and good plowing depth control can be performed.
9 to 11 show another form of the urging means comprising the gas spring 27. The front end side of the piston rod 48 of the gas spring 27 is pivotally supported on the machine frame side bracket 30, and the rear cover is shown. The tube 46 of the gas spring 27 is supported on the tube holder 71 supported by the side bracket 31 so as to be rotatable about the left and right axis so as to be relatively movable in the axial direction, and the relative movement of the tube 46 with respect to the tube holder 71 is restricted to gas. A lock mechanism that switches between an urging state in which the urging force of the spring 27 acts on the rear cover 20 and a free state in which the urging force of the gas spring 27 does not act on the rear cover 20 while allowing the tube 46 to move relative to the tube holder 71. 72 is provided.

A stay 73 to which the mounting portion 52 of the ball joint 54 on the front end side of the piston rod 48 is attached is fixed to the machine frame side bracket 30.
The tube holder 71 includes an outer structure 74, a pivot shaft 75 provided in the outer structure 74, and an inner structure 76 provided in the outer structure 74.
The outer structure 74 includes an inner wall 74a, an outer wall 74b disposed on the outer side in the left-right direction of the inner wall 74a, and an upper wall 74c that connects upper portions of the inner wall 74a and the outer wall 74b. And a lower wall 74d extending inward in the left-right direction from the lower end of the outer wall 74b, and the front and rear surfaces are formed in an open hollow shape.

The outer wall 74b, the upper wall 74c, and the lower wall 74d are integrally formed.
A gap 78 is provided in the front-rear direction between the inner edge of the lower wall 74d and the inner wall 74a. The gap 78 gradually increases from the substantially central part in the front-rear direction to the rear, and the rear end of the lower wall 74d is It coincides with the rear end of the outer side wall 74b.
In addition, a first guide groove 79 is formed in the rear portion of the lower wall 74d in an inclined direction that moves forward as it goes outward in the left-right direction from the inner edge to the outer wall 74b. The second guide groove 80 is formed in an inclined direction that moves forward as it goes upward in the middle of the direction, and the first guide groove 79 and the second guide groove 80 are formed continuously.

The pivot shaft 75 is provided so as to project inward in the left-right direction at a midway portion in the front-rear direction of the inner wall 74 a of the outer structure 74, while a support base 81 having a U-shaped cross section is provided on the rear cover side bracket 31. A support cylinder 82 having a lateral axis is fixed to the rear portion of the support base 81, and the pivot shaft 75 is inserted into the support cylinder 82 to prevent the tube holder 71 from coming off. It is supported so as to be rotatable around the axis of the pivot shaft 75.

The tube 46 is rotatable around the pivot shaft 75, and the axis of the pivot shaft 75 is a pivot point X on the tube 46 side of the gas spring 27.
The inner structure 76 is formed by cutting out a part of a cylindrical body that is open at both ends in the axial direction over the axial direction, and the outer structure is configured such that one end in the axial direction faces the front side and the other end faces the rear side. It is inserted into the front part in 74 and fixed to the outer structure 74.

The notch 83 of the inner structure 76 is located on the lower side.
A tube 46 of the gas spring 27 is inserted into the inner structure 76 so as to be movable in the axial direction, whereby the tube 46 of the gas spring 27 is supported by the tube holder 71 so as to be movable in the axial direction.
A grip 84 is detachably attached to the attachment portion 51 of the ball joint 53 at the end of the tube 46.

In a state where the grip 84 is directed downward (facing downward), the tube 46 is slidable in the axial direction within the inner structure 76, and the tube 46 is rearward from the tube holder 71. The mounting portion 51 is configured not to come out by coming into contact with the inner end side in the left-right direction of the first guide groove 79 toward the front side.
When the tube 46 is inserted into the inner structure 76, the attachment portion 51 is inclined obliquely with the grip 84 removed, and the tube is passed through the notch 83 of the inner structure 76 and the gap 78 of the outer structure 74. 46 can be inserted into the inner structure 76.

  In the embodiment having the above-described configuration, by grasping the grip 84 and moving the mounting portion 51 of the ball joint 53 on the tube 46 side from the first guide groove 79 to the end portion of the second guide groove 80. Further, the relative movement of the gas spring 27 with respect to the tube holder 71 in the axial direction is prevented, and the piston rod 48 of the gas spring 27 is inserted, and the rear cover 20 can be urged downward. .

Conversely, the attaching portion 51 is detached from the second guide groove 80 and the first guide groove 79 so that the grip 84 faces downward, so that the urging force of the gas spring 27 is applied to the rear cover 20. It can be in a free state that does not act on.
The lock mechanism 72 includes first and second guide grooves 79 and 80, a mounting portion 51 of the ball joint 53 at the end of the tube 46, a grip 84, and the like.

Other configurations are the same as those of the embodiment shown in FIGS.
FIGS. 12 to 14 show another form of the urging means comprising the gas spring 27. A support cylinder 86 externally fitted to the tube 46 so as to be relatively movable in the axial direction is mounted on the machine frame side bracket 30. FIG. The bottom side of the tube 46 so as to follow the vertical movement of the rear cover 20 while restricting the position of the bottom side end portion of the tube 46 to the machine frame side bracket 30. A first guide member 87 for guiding the end portion is provided, and the front end side of the piston rod 48 is positioned so that the urging force of the gas spring 27 acts on the rear cover 20 on the rear cover 20 side bracket 31. A positioning member 88 is provided for releasing the positioning so that the urging force of the gas spring 27 does not act on the rear cover 20, and the rear cover 20 side is provided. The racket 31, is provided with a second guide member 89 for guiding the piston rod 48 the distal end side so as to follow the vertical movement of the rear cover 20 to support the piston rod 48 the distal end side at the time of the free state.

  The support cylinder 86 is provided with a pivot shaft 90 projecting inward in the left-right direction. The pivot shaft 90 has a left-right axis and passes through the machine frame side bracket 30. By attaching retaining members positioned on both the left and right sides of the machine frame side bracket 30 to the support shaft 90 and sandwiching washers 91 between the retaining members and the machine frame side bracket 30, the support cylinder 86 is rotated around the left and right axes. It is supported rotatably.

The axis of the pivot shaft 90 is a pivot point X on the tube 46 side of the gas spring 27.
A guided member 93 having a collar 92 is fixed to the mounting portion 51 of the ball joint 53 on the end side of the tube 46.
An arc-shaped first guide groove 94 is formed in the first guide member 87, and the collar 92 of the guided member 93 is inserted into the first guide groove 94, so that the tube bottom side end of the gas spring 27 is inserted. The part is configured to be guided.

The second guide member 89 is formed with a second guide groove 95 that guides the ball joint 54 on the front end side of the piston rod 48 in a direction substantially along the axial direction of the gas spring 27.
The positioning member 88 is provided with a rotation shaft 96 having a left and right axial core on one end side, and the rotation shaft 96 is inserted into a cylindrical portion 97 provided on the front end side upper portion of the second guide member 89. It is attached so as to be rotatable around the left and right axis.

A fixing tube 98 is provided on the other end side of the positioning member 88.
The positioning member 88 is in contact with the ball joint 54 on the front end side of the piston rod 48 from behind when the front end side of the piston rod 48 of the gas spring 27 is positioned on the front end side of the second guide groove 95, and The front end of the piston rod 48 is fixed to the second guide member 89 by fixing the positioning member 88 non-rotatably by a fixing pin 99 that passes through the fixing cylinder 98 on the other end side and penetrates the rear cover 20 side bracket 31. In this state, the gas spring 27 is biased to bias the rear cover 20 downward.

Further, the ball pin 54 at the tip of the piston rod 48 is moved into the second guide groove 95 by removing the fixing pin 99 and rotating the positioning member 88 upward to a position not crossing the second guide groove 95. Accordingly, the gas spring 27 enters a free state in which no urging force is applied to the rear cover 20.
A holding cylinder 100 is provided on the rear upper surface side of the second guide member 89. By inserting the fixing pin 99 into the holding cylinder 100 and the fixing cylinder 98 on the other end side of the positioning member 88, the holding cylinder 100 is free. In the state, the positioning member 88 can be held.

Other configurations are the same as those of the embodiment shown in FIGS.
16 and 17 show a modification of the urging structure of the rear cover 20 by the gas spring 27 of the embodiment shown in FIGS.
In the urging structure of the rear cover 20 by the gas spring 27 shown in FIGS. 1 to 8, normally, when the rear cover 20 swings up and down, the link 65 and the tube follow the vertical swing of the rear cover 20. 46, the rear cover 20 suddenly descends, and the gas spring 27 may not be able to catch up with the lowering operation of the rear cover 20. When the link 65 pulls the link 65, the link 65 swings downward around the pivot shaft 66, and the gas spring 27 may fall for a moment. When the gas spring 27 may fall, the gas spring 27 is moved to the rear cover 20. Or the rear end side of the upper cover 19 or the like.

  Therefore, in the configuration shown in FIGS. 16 and 17, the link 65 and the tube 46 are linked together so that the link 65 and the tube 46 are always rotated integrally around the pivot shaft 66. The joint member 102 is provided. In this respect, unlike the urging structure of the rear cover 20 by the gas spring 27 shown in FIGS. 1 to 8, the other structures are the same as those shown in FIGS.

The engaging member 102 is formed by bending an elongated strip-shaped spring member, and the straight fixing piece 103 and the lengthwise direction of the fixing piece 103 from both ends of the fixing piece 103 in the length direction. And a pair of engagement pieces 104 extending so as to face each other.
The fixing piece 103 of the engaging member 102 is arranged so that its length direction coincides with the short direction of the link 65 and is at the rear end side of the link 65 and opposite to the fixing side of the pivot shaft 66. The engaging piece 104 is opposed to the upper and lower sides (in the radial direction of the tube 27), and the tube 46 of the gas spring 27 is sandwiched between the upper and lower engaging pieces 104. Yes.

  Further, the upper and lower engaging pieces 104 are formed such that a midway portion in the longitudinal direction is curved toward the opposite side so as to correspond to the outer peripheral shape of the tube 46 of the gas spring 27. The interval between the tip ends of 104 is narrower than the radial width of the tube 46 of the gas spring 27, and the tube 46 is elastically deformed so that the interval between the engagement pieces 104 is widened. Thus, it is inserted between the engagement pieces 104.

Even if the rear cover 20 is about to fall rapidly by linking the link 65 and the tube 46 so as to always rotate integrally around the pivot shaft 66 by the engaging member 102, the link 65 and the gas spring. 27 follows the swinging of the rear cover 20 and rotates integrally around the pivot shaft 66.
The engaging member 102 may be formed of a thin round bar-like spring member such as a piano wire, and the engaging member 102 may not be formed of a spring member.

It is a side view of the urging means of the rear cover. It is a side view of a tillage device. It is a side view of a gas spring attachment part. It is a schematic plan view of the urging means of the rear cover. It is a plane sectional view of a gas spring attachment portion. It is side surface partial sectional drawing of a bouncing apparatus. It is a side view which shows the state which changed the back cover up and down in the state which applied the urging | biasing force of the gas spring. It is a side view which shows the state which changed the back cover up and down in the state which does not apply the urging | biasing force of a gas spring. It is the side schematic diagram of the rear cover energizing means concerning other forms using a gas spring. It is a plane schematic diagram of the rear cover urging means according to another embodiment using a gas spring. It is sectional drawing which shows the tube support part of the gas spring of the rear cover urging means which concerns on another form, (a) is a plane sectional view, (b) is a side sectional view, (c) is a back sectional view. It is the side schematic diagram of the rear cover energizing means concerning another form using a gas spring. It is a plane partial sectional view of the rear cover urging means concerning another form using a gas spring. It is a side view which shows the state which changed the back cover up and down in the state which applied the urging | biasing force of the gas spring of the rear cover urging means which concerns on another form. It is the side schematic diagram of the rear cover energizing means using the gas spring concerning a comparative example. It is a side view which concerns on the modification of the urging | biasing structure of the rear cover by a gas spring. (A) is a plane sectional view of the pivotal support part of the tube side of the gas spring which concerns on a modification, (b) is the same rear view.

2 Machine frame 3 Tillage part 20 Rear cover 27 Gas spring 27a Tube bottom side end of gas spring 30 Machine frame side bracket 31 Rear cover side bracket 46 Tube 46C Tube rod side end 48 Piston rod 51 Mounting part (fixing tool)
65 link 71 tube holder 72 lock mechanism 86 support cylinder 87 first guide member 88 positioning member 89 second guide member X pivot point

Claims (3)

A rear cover (20) that covers the rear of the tillage part (3) provided at the lower part of the machine frame (2) is provided, and the front end of the rear cover (20) is provided so that the rear cover (20) can swing up and down. The tube (46) is supported on the side of the machine frame (2) so as to be rotatable about the left and right axis, and a tube (46) filled with compressed gas , and a piston (47) provided in the tube (46) so as to be axially movable. ), An orifice (49) formed in the piston (47) for communicating the rod side chamber (46A) and the bottom side chamber (46B) of the tube (46), and the piston (47). A gas spring (27) provided with a moving piston rod (48) is provided, and one end side of the gas spring (27) is urged downward by the gas spring (27). On the machine frame (2) side In tilling apparatus is pivotally supported at the other end side of the gas spring (27) to the rear cover side bracket (31) provided on the rear cover (20) as well as pivotally supported on the machine frame side bracket (30) has,
The tube (46) pivot point side (X) of the gas spring (27), Ru is positioned inward in the length direction of the gas spring (27) than the bottom end of the tube (46) (46C) Accordingly, a link (65) whose one end is pivotally supported is provided on the machine frame side bracket (30) or the rear cover side bracket (31) and the bottom side of the tube (46) is attached to the other end of the link (65). A tilling device characterized in that the tube (46) side of the gas spring (27) is rotatable around the pivot point (X) on the one end side of the link (65) by attaching a portion (51) . A lowering device (26) provided between the machine frame side bracket (30) and the rear cover side bracket (31) and biasing the rear cover (20) downward by a spring (29) is provided. The tillage device according to claim 1 characterized by things. The gas spring (27) is disposed below the retracting device (26) and above the pivotal support shaft (25) that supports the rear cover (20) so as to be swingable up and down. The tillage device according to claim 2 to do.

Images