JP4291165B2 - Loading platform lifting device - Google Patents

Description

  The present invention relates to a load receiving platform lifting device provided at a rear portion of a load carrier of a cargo vehicle such as a van type truck.

  2. Description of the Related Art Conventionally, a large number of load receiving platform raising / lowering devices are provided in which a load receiving platform is provided at a rear end of a cargo loading platform via a link mechanism.

  This load receiving platform lifting device is freely movable up and down between the highest position where the load receiving platform is substantially flush with the floor surface of the load platform and the lowest position where the load receiving platform contacts the ground. Then, it shifts to a tilting operation and the rear end of the load receiving platform is grounded to the ground. Further, the load receiving platform is rotated to the loading platform side in the upmost position so as to be stowed for storage, running, and the like.

The mechanism for raising and lowering and tilting the load receiving platform as described above raises and lowers the load receiving platform while maintaining its horizontal state via the link mechanism by the expansion and contraction operation of the lift cylinder, and the retracting operation of the lift cylinder at the lowest position. In association with this, the tilt link supported on the vehicle body side is swung rearward to change the form of the link mechanism to tilt the load receiving platform (see, for example, Patent Document 1).
JP 2001-233114 A

  However, the above conventional ones have the following problems.

  The load receiving platform starts to tilt by the swinging action of the tilt link to the rear by the contracting operation of the lift cylinder, which is continued after touching the ground, and the tilting operation is ended by contracting the lift cylinder to the most contracted position. To do.

  Therefore, when the height position for mounting the load receiving platform lifting device on the vehicle changes due to the difference in the size of the vehicle, for example, when the height position for mounting the load receiving platform lifting device on the vehicle becomes low The tilting operation is performed until the timing at which the load receiving platform reaches the lowest position is advanced, the tilting operation is started from this position, and the lift cylinder is fully contracted.

  As a result, the useless tilting operation is continued until the lift cylinder is contracted to the maximum even though the tip of the load receiving table is in contact with the ground and the tilting is actually completed. This wasteful tilting operation causes the load receiving table to slide on the ground, and the load generated on each component member causes damage or damage to each component member, thereby reducing the durability of the entire device. I was invited.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a predetermined swing for the tilt link that directly controls the tilting operation of the load receiving table accompanying the contraction operation of the lift cylinder. An object of the present invention is to provide a load receiving table lifting / lowering device capable of performing an appropriate tilting operation in accordance with the mounting position of the load receiving table lifting / lowering device with respect to a vehicle by regulating the position.

  In order to achieve the above object, the load receiving platform lifting apparatus according to the first aspect of the present invention is configured such that the load receiving platform can be lifted and lowered via a link mechanism by an expansion and contraction operation of a lift cylinder between a loading platform mounted on a vehicle and the ground. A load receiving device that can be tilted so that the rear end of the load receiving table is brought into contact with the rear side of the tilt link supported on the vehicle body accompanying the contraction operation of the lift cylinder at the lowest lowered position that is grounded on the ground. The table elevating device is provided with restricting means for restricting the backward swing of the tilt link at a predetermined swing position.

  According to a second aspect of the present invention, the restricting means includes a stopper integrated with the tilt link, and the stopper abuts against the tilt link to restrict the tilt link at a predetermined swing position. The contact member is configured such that the timing of contact of the stopper can be adjusted.

  According to the present invention, the position for restricting the swinging motion of the tilt link can be adjusted in accordance with the change in the body position of the load receiving platform lifting device, so that the load receiving platform is appropriate for each vehicle having a different size. It is possible to mount the load receiving table elevating device while tilting to the right.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a load receiving table lifting / lowering device of the present invention provided in a cargo vehicle.

  In FIG. 1, a cargo receiving platform lifting / lowering device 1 is attached to a rear portion of a vehicle body frame including a main frame of a cargo vehicle (not shown) via a support member 10. The load receiving platform lifting / lowering device 1 includes a tilt link 2, a tension arm 3, a compression arm 4, a link arm 5 and a lift cylinder 6 (only one of which is shown) and a load receiving stand 7, which are arranged on the left and right, respectively.

  The support member 10 is fixed to the rear end portion of the vehicle body frame, and is made of a frame material extending in the vehicle width direction below the rear end portion of the vehicle body frame. The left and right positions of the support member 10 are opposed to the vehicle width direction. A support bracket 11 including a facing piece 11a is fixed.

  Each tilt link 2 is formed in a substantially U-shaped cross-section that opens to the rear of the vehicle body frame and extends in the vertical direction. The upper end (base end) of the tilt link 2 is located above the opposing piece 11a of the support bracket 11 via a pin 21. The lower end side (front end side) is pivotably connected so as to swing in the contact / separation direction with respect to the support member 10, that is, the longitudinal direction of the vehicle body. In this case, each tilt link 2 is mutually converted into a retracted position in which the lower end side of the tilt link 2 is stored in contact with the support member 10 side and a disengagement position in which the tilt link 2 separates from the support member 10 side toward the rear of the vehicle body. Yes.

  Further, a stopper arm 22 as a stopper extended forward from the upper end of the tilt link 2 is provided integrally with the tilt link 2.

  The stopper arm 22 is provided such that the tip thereof can come into contact with the upper end of an adjuster bolt 23 as a contact member provided on the support member 10 side. The stopper arm 22 regulates the tilting operation of the load receiving base 7 by restricting the movement of the tilt link 2 in the detaching direction with the tip abutting against the adjuster bolt 23 during the tilting operation of the load receiving base 7 described later. belongs to. Therefore, by adjusting the screwing amount of the adjuster bolt 23, the timing at which the tilting operation of the load receiving platform 7 is regulated can be adjusted by adjusting the timing at which the stopper arm 22 abuts.

  Each tension arm 3 extends in the front-rear direction of the vehicle body, and its front end (base end) is rotatably connected to the tilt link 2 via a pin 31 near the upper end portion thereof. The rear ends (tips) of the lift arms 3 are rotatably connected to the left and right positions of the base end portion of the load receiving platform 7 via pins 32, respectively.

  Each compression arm 4 is disposed below the tension arm 3 so as to extend in the longitudinal direction of the vehicle body. The front end of each compression arm 4 is rotatably connected via a pin 41 between an opposing piece 11a on the outside of the support bracket 11 and a bracket piece 12 facing the opposing piece 11a from the outside. Yes. On the other hand, the rear end of each compression arm 4 is rotatably connected to the lower end portion of the link arm 5 via a pin 42.

  Each link arm 5 has an upper end portion rotatably connected to the left and right end positions of the base end portion of the load receiving stand 7 together with the rear end of the tension arm 3 via the pin 32. That is, the distal end portion of the compression arm 4 is connected to the proximal end portion of the load receiving platform 7 via the link arm 5.

  Each lift cylinder 6 is composed of a hydraulic cylinder, and is disposed below the tension arm 3 so as to extend in the longitudinal direction of the vehicle body. The front end of each lift cylinder 6 is rotatably connected to the lower end of the tilt link 2 via a pin 61. On the other hand, the rear end of each lift cylinder 6 is rotatably connected to the front end side of the substantially intermediate portion of the tension arm 3 via a pin 62.

  The load receiving platform 7 is raised by moving each lift cylinder 6 and positioned at the highest position where it is substantially flush with the floor surface of the load platform, while the load receiving platform 7 is lowered by contracting each lift cylinder 6. Thus, it is positioned at the lowest descending position (position shown in FIG. 1) that contacts the ground (ground) G.

  The load receiving platform 7 has a substantially triangular shape when viewed from the side, and is in an up-and-down operation state in which the mounting surface 71 (upper surface) is horizontal, and a downward direction in which the rear end (front end) of the mounting surface 71 contacts the ground G. They are converted into a tilted state (the state shown in FIG. 1).

  The load receiving platform 7 is held in a horizontal state by the left and right sides of the base end portion being in contact with the rear end edge of the link arm 5, and is pivoted upward about the pin 32 to be placed at the rear portion of the loading platform. It can be stowed and placed upright.

  Next, the tilting operation accompanying the lifting / lowering operation of the load receiving platform 7 by the above-described load receiving platform lifting / lowering apparatus 1 will be described.

  First, the lift cylinders 6 are contracted in a state where the load receiving platform 7 is located at the highest position, so that the pins 61 at the front ends of the lift cylinders 6, the pins 31 at the front ends of the tension arms 3, and the compression arms 4. The lift cylinders 6, the tension arms 3 and the compression arms 4 are rotated downward around the front end pins 41, respectively.

  Thereby, the cargo receiving stand 7 is lowered while being held in a horizontal state. At this time, each tilt link 2 is subjected to a force toward the disengagement position at the rear of the vehicle body because the load receiving platform 7 is loaded on each lift cylinder 6 when the load receiving platform 7 is being lowered. It is held in the storage position.

  In this way, when the load receiving platform 7 is lowered in the horizontal state and the base end of the load receiving platform 7 comes into contact with the ground G, each tilt link 2 swings backward to the vehicle body to the disengagement position as each lift cylinder 6 contracts. Accordingly, each tension arm 3 is moved rearward, so that the rear end of the load receiving platform 7 (mounting surface 71) tilts downward with the pin 42 at the rear end of each compression arm 4 as a fulcrum, and automatically enters a tilted state. Converted.

  In this case, the conversion of the load receiving platform 7 into the tilted state is such that when the front end of the lower surface of the load receiving platform 7 descending while maintaining the horizontal state first contacts the ground G, a downward load is applied to the rear end of the load receiving platform 7. Is performed by the action. That is, each lift cylinder 6 is further contracted from the ground contact position of the load receiving platform 7 by the load at the ground contact position of the load receiving platform 7, and each tilt link 2 is swung rearward of the vehicle body so that the pin 32 at the rear end of each tension arm 3 is moved. By moving the vehicle body rearward, the rear end of the load receiving platform 7 tilts downward.

  Thus, when the load receiving platform 7 is lowered to the grounding position where it contacts the ground G, each tilt link 2 automatically swings to the rear side of the vehicle body to the disengagement position. The rear end can be automatically tilted downward, and the cargo can be loaded and unloaded smoothly.

  On the other hand, when lifting the load receiving platform 7 in the tilted state described above from the ground contact position, each lift cylinder 6 is operated to extend so that the rear end of the load receiving platform 7 is lifted upward by the reverse operation to the above. By the extension operation of each lift cylinder 6 which is continuously performed as it is, the load receiving platform 7 rises while being held in a horizontal state and is disposed at the highest position.

  Further, the load receiving platform 7 can be stored in the upright position by rotating the load receiving platform 7 around the pin 32 to be in an upright state. Thus, the above-described lifting / lowering operation of the load receiving platform 7 can be performed. Note that the load receiving platform 7 may be arranged in the standing state and the horizontal state by an operator's manual operation, or may be performed by, for example, an expansion / contraction cylinder and an expansion / contraction operation of the expansion / contraction cylinder. .

  By the way, the tilt link 2 that directly controls the tilting operation of the load receiving platform 7 as described above is configured such that the backward swing is restricted at a predetermined swing position by the stopper arm 22. Specifically, when the tilt link 2 swings backward by a predetermined angle due to the contraction of the lift cylinder 6, the tip of the stopper arm 22 comes into contact with the head of the adjuster bolt 23 so that the tilt link 2 swings. It is forcibly stopped.

  Thereby, even if the lift cylinder 6 is not contracted to the maximum, the swing operation of the tilt link 2 can be forcibly stopped, and the subsequent useless swing operation can be restricted.

  Further, the position at which the stopper arm 22 abuts by the adjuster bolt 23, that is, the position at which the tilting link 2 stops swinging backward can be adjusted, thereby adjusting the tilt angle at which the load receiving platform 7 finishes tilting. be able to.

  Therefore, when the height position where the load receiving device lifting apparatus 1 is mounted with respect to the ground changes due to the difference in the size of the vehicle, the timing at which the stopper arm 22 contacts the adjuster bolt 23 is adjusted by the adjuster bolt 23. By adjusting, it is possible to obtain an appropriate tilt of the load receiving platform 7 according to the mounting position of the load receiving platform lifting device 1.

  For example, when the height position of the load receiving platform lifting device 1 with respect to the ground is lowered, the load receiving stand 7 reaches the lowest lowered position earlier than when it is higher and starts the tilting operation. The stopper arm 22 is quickly brought into contact with the adjuster bolt 23 so that the tilt link 2 is quickly stopped so that the tilting operation is completed when the rear end of the load receiving platform 7 contacts the ground. Can be.

  As shown in FIG. 2, if the tilt link 2 is not provided with the stopper arm 22, the tilting operation is started after the load receiving platform 7 reaches the lowest position, and the rear end of the load receiving platform 7 is grounded to the ground. Even in this case, the tilt link 2 swings backward until the lift cylinder 6 contracts to the maximum, and the tilting operation of the load receiving platform 7 is continued. That is, the tilt link 2 continues to swing rearward by the contraction of the lift cylinder 6 and the tension arm 3 is moved rearward so that the load receiving base 7 slides backward on the ground in a form away from the link arm 5. Although it moves, such a useless tilting operation can be restricted by restricting the tilt link 2 at a predetermined swing angle as in the present invention.

  As a result, it is possible to prevent a load generated on each component member due to the above-described useless tilting operation, and to prevent breakage or damage of each component member due to the load, thereby improving the durability of the entire apparatus. be able to.

  In this manner, by adjusting the position for restricting the swinging motion of the tilt link 2 in accordance with the change in the mounting position (height position) of the load receiving platform lifting / lowering device 1, it is possible to receive the load on each vehicle having a different size. The load receiving table elevating device 1 can be mounted in a state where the table 7 is tilted appropriately.

It is a side view which shows the cargo receiving stand raising / lowering apparatus of this invention. It is a side view for demonstrating the tilting operation | movement of the load receiving table raising / lowering apparatus when there is no stopper in a tilt link.

Explanation of symbols

1 Cargo stand lifting device 2 Tilt link 22 Stopper arm (stopper)
23 Adjuster bolt (contact member)
3 Tension arm 4 Compression arm 5 Link arm 6 Lift cylinder 7 Loading platform

Claims (2)

A load receiving platform is provided between the loading platform mounted on the vehicle and the ground so that it can be raised and lowered via a link mechanism by the expansion and contraction of the lift cylinder, and the vehicle body side that accompanies the shrinking operation of the lift cylinder at the lowest lowered position grounded on the ground In the load receiving platform lifting device that is tiltable so that the rear end of the load receiving platform is grounded by swinging backward of the tilt link supported by
A load receiving platform elevating device, characterized in that a restricting means for restricting the tilt link from swinging backward at a predetermined swing position is provided. The restricting means includes a stopper provided integrally with the tilt link, and a contact member that abuts on the tilt link and restricts the tilt link swinging at a predetermined swing position. The load receiving table lifting / lowering device according to claim 1, wherein the contact timing is adjustable.

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