JPH11240400A - Rear bumper device for vehicle with load board lifting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adverse effect to a load board lifting device at the time of a collision and prevent deformation and damage of a rear bumper caused by interfering with the ground at the time of being moved to the ground side so as not to inhibit the operation of the load board lifting device in a vehicle having a load board lifting device at the rear part of a car body. SOLUTION: A first arm 23 and a second arm 25 are pivotally provided on the side of a car body 2. A rear bumper 28 fixed on the second arm 25 is suspended from a link mechanism 14 by means of chain 29 and a torsion bar 33 is provided for energizing the first arm 23 always in an upward direction when the link mechanism 14 is pivotally moved. Therefore, when a load board 15 is moved, the rear bumper 28 is pivotally moved with the link mechanism 14 so that an interference with the link mechanism 14 is prevented and that, by means of the energizing force by the torsion bar 33, the rear bumper 28 will not abut on the ground prior to the load board 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear bumper device used for a vehicle provided with a loading / unloading device at a rear portion of a vehicle body.

[0002]

2. Description of the Related Art In general, a loading / unloading device for loading / unloading cargo is provided with a loading tray at the tip of a parallel link, and the parallel link is rotated up and down to raise and lower the loading tray in a substantially horizontal state. Therefore, when the loading / unloading device is provided at the rear portion of the vehicle, there is a problem that the device interferes with a rear bumper provided at the rear portion of the vehicle.

[0003] Conventionally, as disclosed in Japanese Utility Model Laid-Open No. 6-67209, the rear bumper is divided to form an opening, so that the parallel link of the loading / unloading device moves up and down through the opening. The loading platform can be moved up and down without being hindered by the rear bumper. However, in the above structure, since the rear bumper is divided to reduce the strength of the rear bumper, an extra reinforcing member is required to reinforce the rear bumper, which increases the weight of the entire vehicle and reduces the load of luggage. Problems arise.

[0004] Therefore, to solve the above problem,
Although the technical field is different, there is a rear bumper device for a dump truck disclosed in Japanese Utility Model Laid-Open No. 7-19018. In the rear bumper device, a bending arm including a front stay and a rear stay is rotatably provided at a rear portion of the vehicle body, and a rear bumper is fixed to the bending arm.The rear stay is connected to the front stay via a spring. When the packing box is tilted backward, the rear stay abutting on the packing box rotates downward against the spring force to move the rear bumper to the ground side and The rearward stay is returned to the original position by the spring force when the packing box falls down on the vehicle body so as not to hinder the backward tilting.

Therefore, it is easily conceivable that the above-mentioned problem can be solved by mounting the rear bumper device on a vehicle provided with the loading / unloading device. That is, the rear bumper may be moved downward by pushing down the rear bumper by the parallel link of the loading / unloading device, and when the parallel link rotates upward, the rear bumper may be returned to the original position by a spring force. Thus, the rear bumper does not hinder the operation of the lifting / lowering device, so that the rear bumper can have sufficient strength by being formed to have substantially the same width as the vehicle body without being divided.

[0006]

Generally, the rear bumper has a rectangular cross section and a predetermined thickness in the vertical direction. For this reason, when pushing down the rear bumper with the parallel link of the loading / unloading device, the rear bumper projects from the parallel link toward the ground until the parallel link is rotated to a predetermined lowering position. In other words, if the height from the ground to the loading platform is secured so that the parallel link can be rotated sufficiently downward during loading and unloading work, unloading work can be performed without any problem, but irregular terrain where the rear of the vehicle is raised If the height from the ground to the loading platform is low, the rear bumper will touch the ground before the parallel link when the loading platform descends, so not only will the rear bumper be damaged due to interference with the ground, but also the loading platform will be lower than the ground. To stop at the raised position,
There arises a problem that the unloading operation cannot be performed.

Therefore, the present invention is provided with a loading tray lifting device capable of reliably preventing deformation and damage of a rear bumper, which is made possible to the ground side so as not to hinder the operation of the loading tray lifting device, due to interference with the ground. A rear bumper device for a vehicle is provided.

[0008]

According to the present invention, a link mechanism comprising an upper link and a lower link is provided at the rear part of a vehicle body so as to be vertically rotatable, and a load receiving table is provided at a front part of the link mechanism.
In a vehicle with a loading / unloading device that raises and lowers the loading tray in a substantially horizontal state by appropriately rotating the link mechanism by driving means, the base end of the first arm is moved up and down on the rear side of the vehicle body. The first arm is provided rotatably, and the base of the second arm is provided at the tip of the first arm so as to be vertically rotatable. The link of the link mechanism is provided at the tip of the second arm at the top and bottom. And a suspension means for suspending the rear bumper is provided between the rear bumper or the second arm and the link mechanism, and the link mechanism is provided between the first arm and the vehicle body. A biasing means is provided which can constantly bias the first arm tip upward during rotation.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a vehicle 1 for transporting luggage, the vehicle 1 having a cargo box 4 having a carrier 3 on a vehicle body 2.
Is installed. At the rear of the vehicle 1, there is provided a loading / unloading device 5 for loading and unloading cargo, and a rear bumper device 6 for preventing a passenger car or the like colliding from behind the vehicle 1 from entering below the vehicle body 2. is there.

As shown in FIGS. 2 and 3, the loading tray lifting device 5 is provided with a pair of left and right mounting frames 9 at the rear of the vehicle body 2 via a front support bracket 7 and a rear support bracket 8. The frame 9 has a rear end connected by a connection frame 10 and an intermediate portion reinforced by a reinforcement frame 11 having an L-shaped cross section. As shown in FIG. 4, a base of a lifting cylinder 12 serving as a driving means is pivotally supported at the center of the connecting frame 10.
Is supported at the center of a connecting shaft 13 rotatably supported between the mounting frames 9 via a bracket, so that the connecting shaft 13 is rotated by the expansion and contraction operation of the lifting cylinder 12. ing.

A link mechanism 14 is provided at both ends of the connecting shaft 13, that is, at an end located on the outside of the mounting frame 9, and a load receiving table 15 is provided at a leading end of the link mechanism 14. With the rotation of the connection shaft 13, the link mechanism 14 rotates up and down, and the load receiving table 15 moves up and down. The link mechanism 14 forms a parallelogram with an upper link 16 located above, a lower link 17 located below, and an elevating frame 18 connecting the ends of the two links 16, 17. .

The base end of the upper link 16 is pivotally supported by the mounting frame 9, and the load receiving base 15 is pivotally supported at the distal end. The lower link 17 has a two-stage bending structure including a base link 19 inserted into the connecting shaft 13 and a front link 20 pivotally supported by the base link 19, and the front link 20 is a base link. The stopper 21 is fixed to the stopper 19 to restrict downward bending. As a result, the parallelogram is held when the loading tray 15 is moved up and down, and the loading tray 15 is brought into a substantially horizontal state. It is designed to incline.

Next, the rear bumper device 6 will be described. Referring to FIG.
The base of the arm 23 is pivotally supported 24, and each of the first arms 23
The base of the second arm 25 having a U-shaped cross section is pivotally supported at the tip of the first arm 23, and a locking surface 27 integrally formed on the upper surface of the base of the second arm 25 is provided on the upper surface of the tip of the first arm 23. The contact makes it possible to prevent the second arm 25 from rotating upward with respect to the first arm 23 on the same line as the first arm 23.

As shown in FIGS. 3 and 4, a lower rear portion of a rear bumper 28 having a rectangular cross section extending in the width direction of the vehicle body 2 is fixed to the tip of the second arm 25. The rear bumper 28 is a first arm. With the rotation of 23 and the second arm 25,
Projection position projecting rearward of the connection frame 10 (FIG. 1)
And a retracted position (FIG. 2) moved to the ground side below the mounting frame 9.

On the outer surface of the upper link 16, the upper end of a chain 29 serving as a suspending means is supported via a suspending bracket 30, and the lower end of the chain 29 is attached to the back of a rear bumper 28 by a suspending bracket 31. When the rear bumper 28 is suspended from the link mechanism 14, the rear bumper 28 is interlocked via the chain 29 by the vertical rotation of the link mechanism 14.

Reference numeral 32 denotes a pair of right and left receiving members fixed to the rear surface of the rear bumper 28.
By contacting the connecting frame 10 at the eight protruding positions, an impact at the time of collision with the rear bumper 28 is received on the vehicle body 2 side. Between the pair of left and right first arms 23 and the reinforcing frame 11, a pair of right and left torsion bars 33 as urging means for constantly urging the front end of the first arm 23 upward when the link mechanism 14 rotates. It is provided.

The mounting structure of the torsion bar 33 will be described below. Referring to FIGS. 4 to 8, a pair of left and right mounting brackets 34 each having an upward U-shaped cross section are provided on the lower surface of the reinforcing frame 11.
An intermediate support member 35 extending rearward is fixed to both outer surfaces of the torsion bar by bolts 36. The intermediate support member 35 is provided with an intermediate portion 37 of each torsion bar 33 and a pivot point 26 of the second arm 25. And are supported in an inclined state so as not to interfere with each other.

One of the inner bent portions 38 formed at the inner end of each torsion bar 33 is in contact with the lower surface of the mounting bracket 34 and the other is in contact with the lower surface of the reinforcing frame 11 in the mounting bracket 34. On the other hand, each of the first arms 23 has an outer support member 39 on the side surface on which both arms are opposed.
The outer support member 39 supports an outer bent portion 40 formed at the outer end of the torsion bar 33.

When the first arm 23 rotates, the outer bent portion 40 is pushed down, and the inner bent portion 38 is held in contact with the mounting bracket 34 and the reinforcing frame 11, so that the torsion bar is held. 33 is twisted first
An upward biasing force acts on the arm 23. In the present embodiment, the upper end of the chain is supported by the upper link and the lower end is supported by the rear bumper. However, the upper end may be supported by the lower link, or the lower end may be supported by the second arm. Further, although the rear bumper is suspended by a chain, it may be suspended by a rope, a wire, or the like.

Further, in the present embodiment, a pair of left and right torsion bars is provided.
Even when the arm is urged, the same effect can be obtained. Further, the first arm is urged by the torsion bar, but may be urged by an elastic member such as a coil spring. The operation of the present invention having the above-described configuration will now be described. When the vehicle 1 travels, the loading tray 15 is in the upright storage position behind the packing box 4 (the dashed line in FIG. 1).
, The rear bumper 28 is held at the projecting position by the pulling force of the chain 29. Since the outer bent portion 40 and the inner bent portion 38 of the torsion bar 33 are substantially parallel to each other, no upward urging force is applied to the first arm 23 by the torsion bar 33.

When a passenger car or the like collides from behind during traveling, the passenger car or the like hits the vehicle body 2 or tries to enter under the vehicle body 2, but before that, the passenger car or the like hits the rear bumper 28 at the projecting position, and Prevents passenger cars from entering. At this time, since the impact due to the collision acts on the vehicle body 2 via the receiving member 32, it is possible to prevent an adverse effect on the load receiving pedestal 15 elevating device 5 at the time of the collision.

Next, when unloading the load on the loading platform 3 to the ground, the loading platform 15 is moved from the upright storage position to the overhanging extension position (FIG. 1).
After rotating downward to the solid line), the load on the loading platform 3 is moved onto the loading platform 15. Next, the lifting cylinder 12 is driven, the link mechanism 14 is rotated downward, and the load receiving table 15 is lowered. Then, the rear bumper 28 starts rotating downward around the pivot 24 of the first arm 23 while being suspended by the chain 29 by its own weight due to the downward rotation of the upper link 16.

At this time, since the locking surface 27 of the second arm 25 is in contact with the first arm 23, the upward rotation of the second arm 25 with respect to the first arm 23 is restricted. When the rear bumper 28 rotates downward, the outer bent portion 40 of the torsion bar 33 is pushed downward by the downward rotation of the first arm 23, and the inner bent portion 38 is
The torsion bar 33 is twisted because it is held in contact with the first arm 23, and an upward urging force acts on the first arm 23.

The urging force of the torsion bar 33 is gradually increased by the downward rotation of the first arm 23. When the weight of the rear bumper 28 is balanced by the suspension force of the chain 29 and the urging force of the torsion bar 33, The first arm 23 is held at the rotation position θ1 in FIG. 9 by the urging force, and the rear bumper 28 is rotated about the pivot 26 of the second arm 25 because the link mechanism 14 continuously rotates downward. Start turning downward.

At this time, since the pivot 26 of the second arm 25 is separated from the mounting frame 9, it is possible to prevent the locking surface 27 from interfering with the mounting frame 9 due to the rotation of the second arm 25. it can. Thereafter, the rear bumper 28 hangs down on the first arm 23 by its own weight as shown in FIG. 10, and when the chain 29 is loosened and the suspension force of the rear bumper 28 is released, the own weight of the rear bumper 28 acts on the first arm 23. As a result, the rear bumper 28
When the urging force of the torsion bar 33 acting on the first arm 23 is balanced with the weight of the rear bumper 28, the first arm 23 is rotated at the rotation position θ2 in FIG. Is held again.

When the link mechanism 14 is further rotated downward after the rear bumper 28 is held, the center of the lower surface of the lower link 17 contacts the upper edge of the rear surface of the rear bumper 28. Then, the pressing force of the lower link 17 is applied to the rear bumper 28, the first arm 23 rotates downward against the urging force of the torsion bar 33, and the second arm 25 also moves to the shaft fulcrum 2.
6, the rear bumper 28 starts rotating downward together with the lower link 17 in a state where the entire rear surface thereof is in contact with the lower surface of the lower link 17.

At this time, since the lower surface of the lower link 17 is in surface contact with the rear surface of the rear bumper 28, the rear bumper 28 is not damaged by interference with the lower link 17, and the lifting operation can be performed smoothly. When the link mechanism 14 further pivots downward and the lifting frame 18 touches the ground, the stopper 21
As a result, the parallelogram of the link mechanism 14 is released, and the receiving tray 15 is inclined as shown in FIG. 2, and the load on the receiving tray 15 can be lowered to the ground.

At this time, the first arm 23 is held at the rotation position θ3 in FIG. 2 by the urging force of the torsion bar 33, and the second arm 25 is rotated upward by the weight of the rear bumper 28 (counterclockwise in FIG. 2). However, since the upward rotation is restricted by the pressing force of the lower link 17 on the rear bumper 28, the rear bumper 28 is held in contact with the lower link 17 at the center of the lower surface.

When the load receiving table 15 is lowered, the rear bumper 28 is suspended from the chain 29 and rotated downward together with the link mechanism 14, and the first arm 23 is constantly urged upward by the urging force of the torsion bar 33. Since the rear bumper 28 is brought into contact with the lower surface of the link mechanism 14, the rear bumper 28 does not hinder the downward rotation of the link mechanism 14, and the rear bumper 28 does not come into contact with the ground prior to the loading tray 15. Therefore, deformation and damage of the rear bumper 28 moved to the ground side can be reliably prevented.

FIG. 12 shows a state in which the loading tray 15 is lowered at the place where the ground height is low. In this case, the first arm 23 is held at the rotation position θ4 and the rear bumper 28 is moved to the lower surface of the lower link 17. The rear bumper 28 does not interfere with the ground and is not deformed and damaged even in a place where the ground height is low. Next, when loading the luggage on the ground into the cargo box 4, the luggage is placed on the luggage stand 15 in the state of FIG. 2, the lifting cylinder 12 is driven, the link mechanism 14 is rotated upward, and the luggage Raise 15.

Then, since the rear bumper 28 is released from the pressing force by the lower link 17, the first arm 23 is rotated upward by the urging force of the torsion bar 33, and
The arm 25 pivots upward due to the weight of the rear bumper 28, and the rear bumper 28 pivots upward while contacting the lower surface of the lower link 17. When the rear bumper 28 rotates upward, the urging force of the torsion bar 33 gradually decreases, and the first arm 23 is held at the rotation position θ2 in FIG. 11 where the urging force and the weight of the rear bumper 28 are balanced.

When the link mechanism 14 further rotates upward,
The upper end of the chain 29 rises with the upper link 16,
The rear bumper 28 is connected to the upper link 16 via a chain 29.
10, the first arm 23 pivots upward by the suspending force, and when the weight of the rear bumper 28 balances the resultant force of the urging force and the suspending force, the first arm 23 pivots in FIG. It is held again at the position θ1.

Then, the rear bumper 28 rotates upward about the pivot 26 of the second arm 25, and when the locking surface 27 comes into contact with the first arm 23 as shown in FIG. As a result, the rear bumper 28 rotates upward about the pivot 24 of the first arm 23. When the loading platform 15 is raised to the loading platform 3, the second arm 25 contacts the connecting frame 10 and the front surface of the rear bumper 28 contacts the receiving member 32, as shown in FIG. Held in position.

After the loading tray 15 has been moved up, the cargo on the loading tray 15 is loaded on the loading platform 3.

[0035]

As described above, according to the present invention, the rear bumper is rotatably provided on the vehicle body side by the first arm and the second arm, and when the link mechanism is rotated, the rear bumper is suspended from the link mechanism by the suspension means. While rotating while lowering, the first
Since the arm is always urged upward by the urging means, the rear bumper does not hinder the downward rotation of the link mechanism, and the rear bumper moved to the ground side receives the load when the link mechanism rotates downward. Since the rear bumper does not come into contact with the ground before the platform, even when the ground height is low, it is possible to prevent the rear bumper from interfering with the ground and being deformed and damaged.

[Brief description of the drawings]

FIG. 1 is a side view of a rear portion of a vehicle equipped with a rear bumper device of the present invention.

FIG. 2 is a side view of a rear portion of the vehicle at the time of lowering of a loading tray.

FIG. 3 is an AA diagram of FIG. 1;

FIG. 4 is a BB diagram of FIG. 3;

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is a sectional view taken along line DD of FIG. 4;

FIG. 7 is a sectional view taken along line EE of FIG. 5;

FIG. 8 is a sectional view taken along line FF of FIG. 5;

FIG. 9 is an operation state diagram of the rear bumper device.

FIG. 10 is an operation state diagram of the rear bumper device.

FIG. 11 is an operation state diagram of the rear bumper device.

FIG. 12 is a side view of the rear portion of the vehicle at the time of lowering the loading tray when the ground clearance is low.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vehicle 2 body 5 loading tray lifting device 6 rear bumper device 14 link mechanism 15 loading tray 16 upper link 17 lower link 23 first arm 25 second arm 28 rear bumper 29 chain (suspending means) 33 torsion bar (biasing means)

Claims (1)

[Claims] 1. A link mechanism comprising an upper link and a lower link is provided at the rear part of a vehicle body so as to be rotatable up and down, a load receiving table is provided at a front part of the link mechanism, and the link mechanism is rotated by a driving means as appropriate. In the vehicle with the loading / unloading device which raises and lowers the loading tray in a substantially horizontal state, a base end of a first arm is provided at the rear side of the vehicle body so as to be vertically rotatable. A base end of a second arm is provided at the front end so as to be vertically rotatable, and a rear bumper is provided at a front end of the second arm so as to be located on a path on which the link mechanism rotates vertically. Alternatively, a suspending means for suspending a rear bumper is provided between the second arm and the link mechanism, and the first arm tip is always upwardly moved between the first arm and the vehicle body when the link mechanism rotates. Provide biasing means that can bias Rear bumper device in the receiving platform lifting device with a vehicle that.