Work part connection structure for work machine

Abstract

To reduce size and cost of a connection frame of a work part, and to facilitate connection work.SOLUTION: A connection frame 50 includes a first bearing part 121 for rotatably supporting a base end part of an arm 100 at an upper end part, and has a long hole 55 at a lower end part. At the long hole 55, it slidably holds a second bearing part 130 for rotatably supporting a base end part of a soft cylinder 105. A connection bracket 500 includes a first support hole (first boss hole 521) where the first bearing part 121 is connected by a first engagement pin (first docking pin 610) at the upper end part, and has a second support hole (second boss hole 522) where the second bearing part 130 is connected by a second engagement pin (second docking pin 620) at the lower end part. At a peripheral edge of the first support hole, a guide part 530 is formed for guiding the first bearing part 121 to the first support hole, and in a state where the second bearing part 130 is connected to the second support hole by the second engagement pin, the first bearing part 121 is connected to the first support hole by the first engagement pin.SELECTED DRAWING: Figure 3B

Description

[Technical field]

[0001] The present invention relates to a working unit connecting structure for a working machine, and more particularly to a working unit connecting structure in which a connecting frame of a working unit that is detachably connected to a vehicle body is made smaller and less expensive. [Background technology]

[0002] A known example of a connecting structure for a working unit of a work machine is the connecting structure of Patent Document 1 (Japanese Patent No. 6293592). In this connecting structure, as shown in Figures 5 and 6, the base end side of a lift cylinder 105 is supported by a lower end engaging part 540 formed on a connecting bracket 500 at the front of the vehicle body via a connecting member 106 and an engaging pin 107.

[0003] Therefore, the force of the lift cylinder 105 can be directly supported by the connecting bracket 500, and it is possible to prevent a large force from acting on the connecting frame 50 consisting of the first frame portion 51 and the second frame portion 52. This allows the connecting frame 50 to be made smaller and less expensive. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6293592 (Figs. 1 and 2) Summary of the Invention [Problem to be solved by the invention]

[0005] 6, however, the base end of the arm 100, which is subjected to a large load like the lift cylinder 105, is journaled at the upper end of the second frame portion 52 spaced apart from the connecting bracket 500. In addition, the connecting frame 50 is connected to the rising portion 510 of the connecting bracket 500 by inserting a docking pin 54 into a through hole passing through the first frame portion 51 and the second frame portion 52.

[0006] For this reason, the second frame portion 52 protrudes upward from the connecting bracket 500, and therefore the second frame portion 52 needs to have great strength, which limits the size and cost reduction of the connecting frame 50. Also, it is difficult to align the pin hole 53, which is a through hole of the first frame portion 51 and the second frame portion 52, with the pin hole of the rising portion 510 before inserting the docking pin 54, and the connecting work of the connecting frame 50 can be quite time-consuming.

[0007] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to further reduce the size and cost of the connecting frame and to facilitate the connecting operation. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a working unit connection structure for a working machine, which detachably connects a working unit having a pair of left and right arms, an attachment such as a bucket attached to the tip end of the arms, a lift cylinder for raising and lowering the arms in the vertical direction, and a vertically long connecting frame to which the base end sides of the arms and the lift cylinder are respectively connected, to a connecting bracket arranged on a vehicle body of the working machine, the connecting frame having a first bearing portion at an upper end for rotatably supporting the base end of the arms and a long hole at a lower end, the long hole being fitted to The connecting bracket slidably holds a second bearing portion which rotatably supports the base end of the lift cylinder, and the connecting bracket has a first support hole at an upper end to which the first bearing portion is connected by a first engagement pin, while the connecting bracket has a second support hole at a lower end to which the second bearing portion is connected by a second engagement pin, and a guide portion is formed around the first support hole to guide the first bearing portion to the first support hole, and the first bearing portion is connected to the first support hole by the first engagement pin while the second bearing portion is connected to the second support hole by the second engagement pin. Effect of the Invention

[0009] The working unit connecting structure according to the present invention can further reduce the size and cost of the connecting frame and facilitate the connecting operation. [Brief description of the drawings]

[0010] [Figure 1A] 1 is a perspective view of a working unit having a connecting structure of the present invention, as viewed obliquely from the front. [Figure 1B] 1 is a perspective view of a working unit having a connecting structure of the present invention, as viewed from above and in front; [Figure 1C] 1 is a perspective view of a working unit having a connecting structure of the present invention, as viewed from below and in front; [Figure 2A] 1A is a side perspective view of the connecting structure of the working unit, and FIG. 1B is an exploded perspective view of the connecting member at the front of the vehicle body and the connecting frame on the base end side of the working unit. [Figure 2B] FIG. 4 is a top perspective view of the connecting structure of the working unit; [Figure 2C] FIG. 4 is a perspective view of the lower end of the connecting structure of the working unit. [Figure 3A] 1 is a side view of the vehicle body and the working unit in a separated state of the connecting bracket and the connecting frame of the working unit. FIG. [Figure 3B] FIG. 4 is an enlarged side view of the connecting bracket and the connecting frame. [Figure 4] 13 is a side view showing a state in which the connecting frame is connected to the connecting bracket. FIG. [Diagram 5] FIG. 11 is a perspective view of a conventional working unit as seen obliquely from the front. [Figure 6] FIG. 1 is a side view of a conventional working unit connecting structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] ● Overview of the working section Hereinafter, an embodiment of a working unit connection structure according to the present invention and a working machine using the connection structure will be described with reference to the drawings. In the following description, the term "front side" refers to the front of the vehicle body, the term "rear side" refers to the rear of the vehicle body, and the term "left-right direction" refers to the width direction of the vehicle body.

[0012] A working machine using the working unit connecting structure according to the present invention has a somewhat similar appearance to the working machine shown in Fig. 5. The major difference from the working machine shown in Fig. 5 is the structure of the connecting frame 50 of the working unit 40 shown in Figs. 1A to 1C.

[0013] Below, we will explain the working unit 40 including the connecting frame 50, and then we will explain the connecting bracket 500 at the front of the vehicle body 300. Note that arrows X, Y, and Z shown in each figure indicate the front side, height direction, and left and right direction of the vehicle body.

[0014] 1A to 1C are perspective views of working unit 40 viewed from different angles. Working unit 40 has a pair of left and right arms 100, similar to a conventional one. Arm 100 has an arch shape that is bent slightly downward from the longitudinal center toward the tip.

[0015] A bucket 200 is attached as an attachment to the tip of the arm 100. The attachment is not limited to the bucket 200, and various work attachments can be attached. Examples of such attachments include a claw bucket, a manifold fork, a hay fork, a grader, a pallet fork, and a container bucket.

[0016] A swing arm 101 for swinging an attachment is attached to the tip of the arm 100. The swing arm 101 is disposed so as to be swingable in the front-rear direction around a pin 102.

[0017] Cylinder plates 103, 104 are disposed along the arm 100 at two locations, one above and one below, in the longitudinal center of the arm 100, i.e., near the maximum bending portion of the bow shape. A dump cylinder 108 is disposed between the upper cylinder plate 103 and the swing arm 101. The dump cylinder 108 causes the swing arm 101 to swing back and forth about a pin 102.

[0018] The front side of the lift cylinder 105, i.e., the end of the cylinder body, is connected to the lower cylinder plate 104. The second bearing 130 is integrally connected to the rear side of the lift cylinder 105, i.e., the tip of the piston rod 106. Note that the orientation of the lift cylinder 105 may be reversed, with the second bearing 130 integrally connected to the end of the cylinder body, and the tip of the piston rod 106 connected to the cylinder plate 104.

[0019] ●Connected frame 3A and 3B, a vertically elongated connecting frame 50 is attached to the rear base end portion 120 of the arm 100. This connecting frame 50 is made up of a pair of left and right plate members.

[0020] Both upper and lower ends of the pair of left and right plate members are interconnected with the opposing plate members by connecting pins 61, 62. Since connecting frame 50 is not divided into a first frame portion and a second frame portion as in the conventional structure shown in Fig. 6, connecting frame 50 can be easily made smaller and less expensive.

[0021] A first bearing portion 121 is rotatably supported on an upper end portion of a plate member of the connecting frame 50. A base end portion of the arm 100 is connected to this first bearing portion 121.

[0022] An oblong hole 55 is formed in the lower end of the plate member of the connecting frame 50. This oblong hole 55 extends a predetermined length in the longitudinal direction of the plate member.

[0023] A second bearing 130 that rotatably supports the base end of the lift cylinder 105 is slidably held in this long hole 55. The sliding direction of the second bearing 130 is the longitudinal direction of the long hole 55, i.e., the longitudinal direction of the plate member of the connecting frame 50.

[0024] ●Connecting bracket 1A to 1C, connecting brackets 500 are fixedly disposed on both the left and right sides of the front part of vehicle body 300. Connecting bracket 500 has a vertically elongated shape having a linear rising surface 511 on the front side as shown in FIG.

[0025] 2A(b), a connecting member 520 made of a channel steel having a U-shaped cross section is fixed with its opening side facing forward to the rising surface 511. A first boss hole 521 as a first support hole and a second boss hole 522 as a second support hole are integrally formed at both upper and lower ends of the connecting member 520, respectively.

[0026] A guide portion 530 is formed on the periphery of first boss hole 521 on the inner surface of connecting member 520. This guide portion 530 has an inclined guide surface 530a facing first boss hole 521, and an arc portion 530b that is continuous with the upper end of inclined guide surface 530a and is located on the rear side of first boss hole 521.

[0027] The inclined guide surface 530a guides the boss shaft 122 of the first bearing portion 121, which rotatably supports the base end portion of the arm 100, into the first boss hole 521. In addition, the boss shaft 122 guided into the first boss hole 521 is positioned by the arc portion 530b so as to align with the first boss hole 521. The first bearing portion 121 and the boss shaft 122 can be configured to have approximately the same diameter.

[0028] ●How to attach the connecting frame The working unit connecting structure of the working machine is as described above. A method of mounting the connecting frame 50 to the connecting bracket 500 of the vehicle body 300 will be described below with reference to Figures 3A, 3B and 4.

[0029] 3A shows the state in which the working unit 40 has been detached from the vehicle body 300. In this state, the working unit 40 is self-supporting with the connecting frame 50 on the base end side of the arm 100 raised, as the bucket 200 is attached to the ground and the stand mechanism 110 is erected. The height of the connecting frame 50 is assumed to be maintained at the height when it was previously detached from the vehicle body 300.

[0030] 3A, the vehicle body 300 is moved to the right in the figure toward the working unit 40. This allows the long holes 55 at the lower end of the connecting frame 50 to be aligned with the positions of the second boss holes 522 of the connecting brackets 500 on both the left and right sides of the vehicle body 300.

[0031] This overlapping state is shown in Fig. 4(a). In the state shown in Fig. 4(a), the forward movement of the vehicle body 300 is stopped. Then, the second bearing portion 130, which is slidably held in the elongated hole 55, is moved up and down (for example, within about 20 mm) along the elongated hole 55 to align (center) with the second boss hole 522.

[0032] An appropriate amount of play can be provided between the second bearing portion 130 and the elongated hole 55 to allow vertical movement (for example, within about 20 mm) of the second bearing portion 130 along the elongated hole 55. This appropriate amount of play can facilitate alignment (centering) of the second bearing portion 130 and the second boss hole 522.

[0033] Conventionally, if the ground on which an attachment such as the bucket 200 is placed is inclined left-right or muddy, it can be very time-consuming to connect (center) the connecting frame 50. By making the second bearing portion 130 movable up and down along the long hole 55, it is possible to significantly facilitate and speed up the connecting (centering) work, which was previously time-consuming. In addition, the appropriate amount of play around the second bearing portion 130 can be almost or completely eliminated by pulling up the connecting frame 50 in the direction of the arrow as shown in Fig. 4(b)⇒(c) once connection of the working portion 40 is complete.

[0034] With the second bearing portion 130 and the second boss hole 522 aligned (centered), a second docking pin 620 serving as a second engagement pin is inserted into the second boss hole 522. After the second docking pin 620 is inserted, a ring pin for preventing it from coming off is inserted into the tip of the second docking pin 620. Note that a handle 621 on the base end side of the second docking pin 620 is provided to facilitate insertion and removal of the pin.

[0035] 4(a), the first boss hole 521 of the connecting bracket 500 on the vehicle body side and the boss shaft 122 at the upper end of the connecting frame 50 are not yet aligned (centered). In other words, the boss shaft 122 is in a position facing the guide part 530 (in front of the guide part 530).

[0036] Next, the hydraulic couplers 630 of the lift cylinder 105 and dump cylinder 108 of the working unit 40 and the electric connector of the control device are connected to the hydraulic device and battery of the vehicle body 300. Then, with the second docking pin 620 inserted into the second boss hole 522 as shown in Fig. 4(a), the piston rod of the dump cylinder 108 is extended to perform a dump operation of the bucket 200, which is an attachment. Alternatively, instead of the dump operation of the bucket 200, the piston rod 106 of the lift cylinder 105 is retracted (retracted).

[0037] By the dumping operation of the bucket 200, the arm 100 first tilts backward (rotates left in FIG. 4) with the ground end of the stand mechanism 110 as a fulcrum. By further dumping operation, the arm 100 then tilts backward (rotates left in FIG. 4) with the second docking pin 620 as a fulcrum. At this stage, the ground end of the stand mechanism 110 rises up.

[0038] 4(a), (b), and (c) act on the boss shaft 122 of the first bearing portion 121 that supports the base end of the arm 100. This pressing force P guides the boss shaft 122 along the guide portion 530 to the first boss hole 521. Even with the retraction operation (contraction operation) of the piston rod 106 replacing the dump operation, the boss shaft 122 is attracted to the guide portion 530, so that the boss shaft 122 is similarly guided along the guide portion 530 to the first boss hole 521.

[0039] 4(b)⇒(c) as the boss shaft 122 moves upward along the guide portion 530, the connecting frame 50 is pulled up in the direction of the arrow as shown in FIG. 4(b)⇒(c). This movement of the connecting frame 50 moves the second bearing portion 130 to the lower end of the elongated hole 55, and the backlash of the second bearing portion 130 within the elongated hole 55 is almost or completely eliminated.

[0040] In this way, the boss shaft 122 and the first boss hole 521 are aligned (centered). In this aligned (centered) state, the first docking pin 610 serving as the first engagement pin is inserted into the first boss hole 521. Then, a ring pin for preventing the first docking pin 610 from falling out is inserted into the tip of the first docking pin 610. The handle 611 on the base end side of the first docking pin 610 is provided to facilitate insertion and removal of the pin.

[0041] 3A is folded to complete the connection operation of the working unit 40. The working unit 40 can be removed from the vehicle body 300 by reversing the above steps.

[0042] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and various modifications are possible. For example, the shapes of the first boss hole 521 and the second boss hole 522 of the connecting member 520 and the first bearing portion 121 and the second bearing portion 130 of the connecting frame 50 are not limited to the shapes shown in the drawings. These boss holes and bearing portions can be replaced with any conventionally known engagement structure or fitting structure. [Explanation of symbols]

[0043] 40: Working section 50: Connecting frame 53: Pin hole 54: Docking pin 55: Long hole 61, 62: Connecting pin 100: Arm 120: Base end 101: Swing arm 102: Pin 103, 104: Cylinder plate 104: Cylinder plate 105: Lift cylinder 106: Piston rod 106: connecting member 107: engagement pin 108: Dump cylinder 110: Stand mechanism 121: First bearing portion 122: Boss shaft 130: Second bearing portion 200: Bucket (attachment) 300: Vehicle body 500: Connection bracket 510: Rising portion 511: Rising surface 520: Connection member 521: First boss hole (first support hole) 522: Second boss hole (second support hole) 530: Guide part 530a: inclined guide surface 530b: arcuate portion 540: Lower end engagement portion 610: First docking pin (first engagement pin) 611: Handle 620: Second docking pin (second engagement pin) 621: Handle 630: Hydraulic coupler

Claims

1. A working unit connection structure in which a working unit having a pair of left and right arms, an attachment such as a bucket attached to the tip of the arms, a lift cylinder for vertically raising and lowering the arms, and a vertically long connecting frame to which the base ends of the arms and the lift cylinder are respectively connected, is detachably connected to a connecting bracket disposed on a vehicle body of a work machine, The connecting frame has a first bearing portion at an upper end portion thereof for rotatably supporting the base end portion of the arm, and a long hole at a lower end portion thereof, and a second bearing portion for rotatably supporting the base end portion of the lift cylinder is slidably held in the long hole, the connecting bracket has a first support hole at an upper end portion to which the first bearing portion is connected by a first engagement pin, and a second support hole at a lower end portion to which the second bearing portion is connected by a second engagement pin; a guide portion is formed around the first support hole to guide the first bearing portion into the first support hole; A working unit connecting structure for a working machine, characterized in that, with the second bearing portion connected to the second support hole by the second engagement pin, the first bearing portion is connected to the first support hole by the first engagement pin.

2. 2. The working unit connecting structure according to claim 1, wherein the guide portion has an inclined guide surface that faces the first support hole.

3. The working unit connecting structure according to claim 2, characterized in that by tilting the arm backward or shortening the lift cylinder while the second bearing portion is connected to the second support hole by the second engagement pin, the first bearing portion moves along the inclined guide surface of the guide portion to the first support hole, and the second bearing portion moves along the long hole to the lower end of the long hole.

4. A working unit comprising the working unit connection structure according to any one of claims 1 to 3.

5. A working machine comprising the working unit according to claim 4.

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