JPH0220106Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cargo box driving device for tilting and raising/lowering a cargo box of a transport vehicle with respect to a stationary member of the vehicle body.

(Prior art) A conventional cargo box drive device of this type is, for example,
As shown in Publication No. 59-5431, an upper rail is provided at the bottom of the cargo box, a lower rail is provided on the vehicle body stationary member, and a pair of first and second rails are provided on the vehicle body stationary member.
The arms are pivoted in a crosswise manner, the lower end of the first arm is rotatably supported by one end on the side of the vehicle body stationary member, and the upper end of the first arm is movably connected to the upper rail, and The upper end of the second arm is rotatably supported on one end of the upper rail, and the lower end of the second arm is movably connected to the lower rail, while a portion of the upper wall on the other end side of the lower rail is cut out, An opening/closing cover is provided in the notch so that the opening/closing cover can be freely opened and closed, and after opening the notch by sliding the opening/closing cover, the lifting device provided between the vehicle body stationary member and the first arm is moved. By activating the lower end of the second arm, which is movably connected to the other end of the lower rail, the lower end of the second arm is detached from the lower rail via the notch, and the cargo box is tilted; By sliding the opening/closing cover to close the notch and operate the lifting device, both arms are deployed in an X shape between the lower rail and the upper rail, and the cargo box is placed in a horizontal state. I am trying to raise it by

However, according to the above-mentioned loading box drive device,
By sliding the opening/closing cover to close the notch and operate the lifting device,
Both arms are unfolded in an X-shape between the lower rail and the upper rail to raise the cargo box in a horizontal state, while opening the notch of the lower rail by sliding the opening/closing cover. Then, by operating the lifting device and using the moment acting on the second arm from the lifting device to separate the second arm from the lower rail, the cargo box is moved relative to the vehicle body stationary member. Since the loading box is tilted, there is a lack of reliability in switching between raising and tilting the loading box, and in some cases, when the loading box is tilted, the second arm does not separate from the lower rail. There is a possibility that the loading box cannot be tilted, and when the opening/closing cover closes the notch of the lower rail to raise the loading box, the lifting device is driven and the loading box is not attached to the lower rail. Since an upward reaction force acts on the opening/closing cover in proportion to the load, there is a problem in that sufficient rigidity of the opening/closing cover and the sliding mechanism of the opening/closing cover must be ensured.

Therefore, in order to solve the above problems, the applicant of the present application provided a top rail at the bottom of the packing box, and
One end of a lower rail is rotatably supported on a vehicle body stationary member, and a locking mechanism is provided between the lower rail and the vehicle body stationary member, the locking mechanism having a lock member for locking the lower rail to the vehicle body stationary member;
a pair of first and second arms are pivoted in a crossed manner;
A lower end of the first arm is rotatably supported on one end of the lower rail, and an upper end of the first arm is movably connected to the upper rail;
The upper end of the second arm is rotatably supported at one end on the cargo box side, and the lower end of the second arm is movably connected to the lower rail, and the second arm is movably connected to the vehicle body stationary member side and the cargo box side. They developed a driving device for cargo boxes that includes a lifting device between the container and the container.

(Problems to be Solved by the Invention) According to the above-mentioned cargo box driving device, after releasing the lock between the lower rail and the vehicle body stationary member by the locking mechanism, the lifting device is driven to move the cargo box. is inclined together with the lower rail and the first and second arms, and the loaded items are extremely concentrated in front of the upper end of the first arm at the front of the cargo box. and,
As the lifting device is driven, the cargo box swings using the upper end of the first arm as a fulcrum, the rear side of the cargo box is lifted, and both arms are expanded in an X-shape. There is a possibility that it will rise horizontally without tilting.

This idea was developed in view of the above circumstances.
The purpose is to ensure that the loading box can be switched between raising and lowering and tilting the loading box reliably and smoothly, and that when the loading box is switched to tilting operation, the loading box cannot be locked to the lower rail even during the tilting operation. To provide a driving device for a cargo box which can perform a confirmation operation and reliably prevent the cargo box from being inadvertently raised in a horizontal state.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides an upper rail on the cargo box, rotatably supports the rear part of the lower rail on a stationary member of the vehicle body, and supports a pair of first and second rails. The second arm is pivoted to cross the second arm, and the first
A lower end of the arm is rotatably supported on the lower rail, an upper end of the first arm is movably connected to the upper rail, and an upper end of the second arm is freely rotatable toward the cargo box. The lower end of the second arm is movably connected to the lower rail, and by locking or unlocking the lower rail with respect to the vehicle body stationary member, the cargo box is selectively inclined or tilted relative to the vehicle body stationary member. In a cargo box driving device for a transport vehicle which is adapted to be moved up and down, a lock lever that engages with the lower rail and locks the lower rail to the vehicle body stationary member is supported in a freely swingable manner on the vehicle body stationary member, and the lower rail includes: supporting a locking lever that swings about the same axis as a swinging fulcrum for the vehicle body stationary member of the lower rail and engages with the cargo box; and the locking lever is interlocked with the lock lever. When the locking lever is switched to the locking operation, the cargo box is locked to the lower rail via the locking lever.

(Function) According to the present invention, since the lock lever that operates the lock lever is provided on the side of the vehicle body stationary member, the position of the lock lever does not change even if the cargo box is tilted, and therefore, for example, If the switching operation of the locking lever is incomplete and the locking lever is not securely engaged with the cargo box while the cargo box is tilting, the cargo box may not be lowered to the side of the vehicle body stationary member. It is possible to operate the lock lever again to ensure that the locking lever is engaged with the cargo box, or to confirm that the locking lever is engaged with the cargo box.

Further, the locking lever is connected to the lower rail,
The locking lever is provided on the lower rail that swings with respect to the vehicle body stationary member, since the lower rail is swingably supported at a position having a fulcrum approximately on the same axis as the swing fulcrum with respect to the vehicle body stationary member. Also, by operating the lock lever provided on the vehicle body stationary member, the locking lever can be smoothly and reliably interlocked.

(Embodiment) An embodiment of the cargo box driving device according to the present invention will be described below based on the drawings.

In the figure, reference numerals 1 and 1 denote a pair of left and right chassis frames that extend in the longitudinal direction on both sides of the loading platform of the transport vehicle and constitute a vehicle body stationary member, and a connecting shaft is connected between the rear end portions of these chassis frames 1 and 1. 2 is constructed, and a lower frame L provided with a pair of left and right lower rails 3 is connected to the connecting shaft 2 so as to be freely swingable.

Specifically, a pair of lower rails 3, 3 having a U-shaped cross section are arranged on the chassis frames 1, 1, and a rear connecting rod 4 is installed between the rear end portions of both lower rails 3, 3. Further, a front connecting rod 5 is installed between the front ends of both lower rails 3, 3, and connecting brackets 6, 6 fixed to both ends of the rear connecting rod 4 are connected to a connecting bracket 7 fixed to the connecting shaft 2. , 7 via the shaft 8,
The rear end portion of the lower frame L is rotatably supported by the chassis frames 1, 1.

Reference numeral 9 denotes a cargo box disposed on the chassis frames 1, 1, and upper rails 1 having the same U-shaped cross section as the lower rails are provided on both sides of the lower surface of the cargo box 9.
0 and 10 are fixed at a narrower interval than the space between the lower rails 3 and 3.

11, 11 and 12, 12 are a pair of first and second arms that hold the cargo box 9 on the chassis frames 1, 1;
1 and 12 are pivotally connected via a pivot 13 in a crosswise manner at their intermediate portions in the longitudinal direction.

The lower end of the first arm 11 is rotatably supported by the rear connecting rod 5, and a guide roller 15 is rotatably attached to the upper end of the first arm 11 via a roller shaft 14. The upper end of the first arm 11 is connected to the upper rail 10 via a guide roller 15 so as to be freely movable in the front and rear direction.

The second arm 12 has an upper end rotatably supported at the rear of the lower surface of the cargo box 9 via a bracket 16, and a roller shaft 1 at the lower end.
A guide roller 18 is rotatably attached via the guide roller 7, and the lower end of the second arm 12 is connected to the lower rail 3 so as to be freely movable in the front and rear directions.

20 connects the cargo box 9 to the chassis frame 1,
1, the lower end of the cylinder 20 is connected to the chassis frame 1, 1.
The piston rod 22 of the hydraulic cylinder 20 is freely connected to a retaining rod 21 installed between the two, and the tip of the piston rod 22 of the hydraulic cylinder 20 is freely connected to a cross arm 23 spanning between the first arms 11, 11. There is.

In the transport vehicle configured as described above, in the embodiment shown in the figure, a first locking mechanism A that locks the front end side of the lower frame L to the chassis frame 1 by manual operation, and a The front end side is elastically locked to the chassis frame 1, and when the load acting on the front end side of the lower frame L exceeds a predetermined value, the locking of the lower frame L to the chassis frame 1 is released. A second locking mechanism B, a first locking mechanism C that locks the rear end of the cargo box 9 to the lower frame L side, and a first locking mechanism C that locks the rear end of the cargo box 9 to the lower frame L side; A second locking mechanism D elastically locks the front end of the cargo box 9, and a second locking mechanism D that elastically locks the front end of the lower frame L to the chassis frame 1 when the cargo box 9 rises in the horizontal direction. An automatic locking mechanism E that locks the vehicle, a detection mechanism F that detects the lifting of the cargo box 9 in the horizontal direction with respect to the chassis frames 1, and a transmission (TM) based on the output signal from the detection mechanism F ) is provided, and these various mechanisms A to G will be explained in detail below.

As shown in FIG. 3, the first lock mechanism A rotatably supports the shaft 8 via a bracket 27 on a cross member 26 installed at the front of the chassis frames 1, 1. 2
Lock levers 29, 29 are fixed to both ends of the lower frame L, and the levers 29, 29 are provided with an engagement groove 31 that engages with a lock pin 30 protruding from the front part of the lower frame L.
and an operation pin 32 for swinging the lever 29, and by the swinging operation of the lock lever 29, the engagement groove 31 is engaged with the lock pin 30, thereby moving the lower frame L into the chassis frame 1. The engaging groove 31 and the locking pin 30 are locked by the locking lever 29 through the locking lever 29, and the engaging groove 31 and the locking pin 30 are
By disengaging from the lower frame L, the front end side of the lower frame L can freely swing relative to the chassis frame 1.

Further, as shown in FIGS. 3 and 4, the second lock mechanism B is fixed to the lower surface of the lower rail 3, and elastically engages with the shaft 28 of the first lock mechanism A to secure the lower frame. A clamp 3 that prevents L from swinging relative to the chassis frame 1.
5, the clamp 35 is formed by bending a plate spring to have a U-shaped cross section, and integrally forms curved clamping parts 37, 37 for clamping the shaft 28 on opposite opposing walls 36, 36. The holding part 3
By the engagement of the shaft 28 between 7 and 37,
The front end side of the lower frame L is elastically locked to the chassis frame 1 via the clamp 35, and a load of more than a predetermined value is applied to the front end side of the lower frame L in a direction away from the chassis frame 1. acts, the opposing walls 36, 36
are elastically deformed in a direction that moves away from each other, thereby releasing the locking of the lower frame L to the chassis frame 1 by the clamp 35.

Further, the first locking mechanism C is for locking the rear end of the cargo box 9 to the lower frame L when the cargo box 9 is tilted. As shown in the figure, the locking lever 40 is attached to the bracket 41 on the rear connecting rod 4 of the lower frame L.
The upper end of the lever 40 is formed with an engaging groove 43 that engages with a lock pin 42 fixed to the lower surface of the cargo box 9, while the lower end of the locking lever 40 and the first lock mechanism A.
A swing arm 44 fixed to the shaft 28 is connected by a connecting rod 45, so that when the first lock mechanism A is operated, the locking lever 40 is interlocked.

Specifically, when the lower frame L is locked to the chassis frame 1 by the swinging operation of the locking lever 29, the locking lever 40 is swung clockwise in FIG. 3 via the connecting rod 45. While the lock lever 40 releases the lock between the cargo box 9 and the lower frame L, the lock lever 29 is swung.
When the lower frame L is unlocked from the chassis frame 1, the connecting rod 45
The locking lever 40 is swung clockwise in FIG.
The rear portion of the lower frame L is configured to be locked to the lower frame L side.

As shown in FIGS. 5 and 6, the second locking mechanism D includes a roller 51 rotatably attached to a frame 50 constructed at the front ends of the upper rails 10, 10, and a roller 51 that is rotatably attached to the frame 50 installed at the front ends of the upper rails 10, 10, and the lower frames L. an elastic body 52 made of rubber that is fixed to the front connecting rod 5 and elastically receives the roller 51, and the elastic body 52 has a fitting groove 53 into which the roller 51 is fitted.
is formed.

By fitting the roller 51 into the fitting groove 53 in the elastic body 52, the front end of the lower frame L is elastically locked to the front end of the cargo box 9, while the lower frame L When a load of a predetermined value or more is applied in a direction away from the upper rail 10, the elastic body 52 is elastically deformed, and the roller 51 is disengaged from the fitting groove 53 of the elastic body 52. Lower frame L
The front end of the box 9 is detached from the front end of the cargo box 9.

Further, the automatic locking mechanism E includes the second arm 1.
Specifically, as shown in FIG. 7, the chassis frame 1
A lock pin 56 is fixed to a support 55 fixed to the front part of the lower rail 3, and a lock lever 59, which is provided with an engagement groove 58 that engages with the lock pin 56, is pivoted to a bracket 57 assembled to the front end of the lower rail 3. The lock lever 59 is freely supported and biased by a spring 60 in a direction in which the engagement groove 58 always engages the lock pin 56, while the upper end of the lock lever 59 is provided with a roller of the second arm 12. Contact portion 6 that contacts shaft 17
1 is provided.

The automatic locking mechanism E described above has the first and second arms 11, 12 folded inwardly of the lower rails 3, 3 approximately horizontally with the lower rails 3, with the pivot shaft 13 as a fulcrum; The guide roller 18 of the second arm 12 is connected to the lower rail 3.
When the guide roller 1 is located at the front end of the
The roller shaft 17 supporting the lock lever 59 presses the contact portion 61 of the lock lever 59 to swing the lock lever 59 clockwise in FIG. While releasing the lock between L and the chassis frame 1, the first and second arms 11 and 12 are expanded in an X shape using the pivot shaft 13 as a fulcrum, and the guide roller 18 of the second arm 12 is released.
However, when the roller shaft 17 moves toward the rear end of the lower rail 3, the roller shaft 17 separates from the contact portion 61 of the lock lever 59, and the lock lever 5
9 is swung counterclockwise in FIG. 8 by the spring force of the spring 60, the engagement groove 61 engages with the lock pin 56, and thereby the front end side of the lower frame L is fixed to the chassis frame 1. It's starting to lock into place.

Further, the detection mechanism F includes a limit switch 65 assembled to the front connecting rod 5 of the lower frame L;
The stopper 65b is attached to the frame 50 installed at the tip of the upper rails 10, 10, and turns off the limit switch 65 when the limit switch 65 comes into contact with the roller lever 65a.

On the other hand, the shift lock mechanism G includes a solenoid 67 that is assembled to the transmission case of the transmission (TM) and is energized when the limit switch 65 is turned on, and a solenoid 67 that is freely swingably supported by the transmission case. It consists of a lock lever 69 interlockingly connected to a movable iron core 68 of 67, and a return spring 70 stretched between the lock lever 69 and the transmission case. Clamping pieces 72, 72 are provided to sandwich the shift inner lever 71.

In the above-described shift lock mechanism G, the lower end of the lock lever 69 is moved within the swinging region of the shift inner lever 71 via the movable iron core 68 by the excitation of the solenoid 67 accompanying the ON operation of the limit switch 65. The shift inner lever 71 is fitted between the clamping pieces 72, 72 of the lock lever 69, and the lever 71 swings.
In other words, the shift operation of the transmission (TM) is locked.

Next, the operation of the transport vehicle having the above configuration will be explained.

First, when the cargo box 9 is not raised in the inclined or horizontal direction, the first and second arms 11, 1
2 is the lower rail 3 placed on the chassis frame 1 with the pivot 13 as a fulcrum;
The cargo box 9, which is folded inwardly in a substantially horizontal manner and supported by both arms 11 and 12, is placed on the lower frame L, and at this time, The shaft 28 constituting the first lock mechanism A is fitted between the clamping parts 37, 37 of the clamp 35 of the second lock mechanism B, and the front end side of the lower frame L is connected to the chassis frame 1, 1, and the second
The roller 51 of the locking mechanism D is fitted into the fitting groove 53 of the elastic body 52, and the front end of the lower frame L is elastically locked to the front end of the cargo box 9. Also, the lock lever 5 of the automatic lock mechanism E
9 is pushed by the roller shaft 17,
9, the lower frame L and chassis frame 1 are unlocked by the lock lever 59.

At this time, the limit switch 65 of the detection device F is turned off due to the contact of the contact 65b with the roller lever 65a, so the solenoid 67 of the speed change lock device G is demagnetized and the lock lever 69 is turned off. The spring force of the return spring 70 causes it to swing clockwise in FIG. 12, and its lower end moves out of the swing area of the shift inner lever 71, causing the shift inner lever 71 to swing, in other words, to shift. The shift operation of the transmission (TM) is free, so the driver can drive by operating the transmission (TM).

However, when the transport vehicle is to run normally from the above state, the lock lever 29 of the first lock mechanism A is swung to engage the engagement groove 3 of the lock lever 29 with the lock pin 30. , the front end side of the lower frame L is fixed to the chassis frame 1, but even if you drive without forgetting to operate the lock lever 29, the lower frame L will be fixed to the chassis frame 1, 1, the lower frame L is elastically locked to the chassis frames 1, 1 via the clamp 35 of the second locking mechanism B. There is no possibility that the front ends of the cargo box 9 or the lower frame L will be lifted off the chassis frames 1, 1, or that the piston rod 21 of the hydraulic cylinder 20 will be extended.

On the other hand, as described above, when the cargo box 9 placed on the lower frame L is raised horizontally with respect to the chassis frames 1, 1, the first lock mechanism A By swinging the lock lever 29, the engagement groove 31 of the lock lever 29 is engaged with the lock pin 30,
At the same time as locking the front end side of the lower frame L to the chassis frame 1 and releasing the lock between the cargo box 9 and the lower frame L by the first locking mechanism C, the hydraulic cylinder 20 is locked. The piston rod 22 may be extended by supplying hydraulic oil to a piston chamber (not shown).
As the piston rod 22 extends, the roller 51 of the second locking mechanism D disengages from the fitting groove 53 of the elastic body 52, and the front end of the lower frame L is unlocked from the cargo box 9. At the same time,
As shown in FIG. 1, the first and second arms 1
1 and 12 are deployed in an X shape between the lower rail 3 and the upper rail 10 with the pivot 13 as a fulcrum, and the upper rail 10 and the cargo box 9 are attached to the lower frame via these two arms 11 and 12. It is sequentially lifted upward in a horizontal state with respect to L and the chassis frame 1.

As described above, as the cargo box 10 rises, the contact 65b of the detection mechanism F moves away from the roller lever 65a and the limit switch 65 turns on, so that the lock lever 69 of the speed change lock mechanism G moves as shown in FIG. oscillate counterclockwise,
The clamping pieces 72, 72 of the lock lever 69 are the twelfth
As shown in the figure, the shift inner lever 71 is clamped, and accordingly, the lock lever 69 prevents the shift inner lever 71 of the transmission (TM) from swinging, and the transmission (TM) is moved from the neutral position. This prevents the vehicle from switching to the traveling stage, and therefore the vehicle is reliably prevented from running in an unstable manner due to the lifting of the cargo box 9.

Further, as the cargo box 9 rises, the lock lever 59 of the automatic locking mechanism E is moved against the spring 6.
It swings counterclockwise in Figure 8 due to the spring force of 0,
The engagement groove 61 engages with the lock pin 56 to lock the lower rail H into the chassis frame 1.
Therefore, if the first locking mechanism A is operated by mistake when the cargo box 9 is raised, the lock lever 29 of the first locking mechanism A will be locked.
Even if the lock between the lower frame L and the chassis frame 1 is released by the automatic locking mechanism E, the lower frame L is fixed to the chassis frame 1 by the lock lever 59 of the automatic locking mechanism E. This prevents the box 9 from tilting during its ascent.

On the other hand, when tilting the cargo box 9 placed on the lower frame L with respect to the chassis frame 1, first move the lock lever 29 of the first lock mechanism A to the position shown by the two-dot chain line in FIG. By swinging the engagement groove 31 and the lock pin 3
0, the front end side of the lower frame L is free to swing with respect to the chassis frame 1, and the locking lever 4 of the first locking mechanism C is released.
0, the rear end of the cargo box 9 is connected to the lower frame L.
The piston rod 22 may be extended by supplying hydraulic oil to the piston chamber (not shown) of the hydraulic cylinder 20, and the extension of the piston rod 22 causes the second lock to Both opposing walls 3 of the clamp 35 constituting mechanism B
6 and 36 are elastically deformed, the clamp 35 is detached from the shaft 28, and the second locking mechanism B locks the lower frame L and the chassis frame 1.
At the same time as the locking with the cargo box 9 is released, the cargo box 9 is
As shown in FIG. 2, the lower frame L and the first and second arms 11 and 12 are gradually tilted.

However, when the cargo box 9 is tilted as described above, if the loaded items are extremely concentrated in the front part of the cargo box 9 and ahead of the upper end of the first arm 11,
As the lifting device 20 is driven, the cargo box 9 swings using the upper end of the first arm 11 as a fulcrum, and the rear side of the cargo box 9 is lifted, and both arms 11 and 12 are moved into an X-shape. Because of the unfolding, there is a risk that the packing box 9 will rise in a horizontal state without tilting. However, according to the device of the present invention, when the packing box 9 is tilted, the first locking mechanism C will prevent the packing box 9 from tilting. Since the rear end of the cargo box 9 is locked to the lower frame L, the cargo box 9
The rear end side is not lifted up from the lower frame L, and therefore the cargo box 9 is reliably tilted.

By the way, when you want to confirm whether or not the locking lever 40 is securely engaged with the cargo box 9 during the tilting of the cargo box 9, or when you want to confirm whether or not the locking lever 40 is securely engaged with the cargo box 9, If the switching operation is incomplete and the locking lever 40 is not securely engaged with the locking pin 42, the locking lever 29 is provided on the vehicle body stationary member side and the cargo box 9 is tilted. Even if the lock lever 29 is moved, the position of the lock lever 29 does not change.
Even if the cargo box 9 is in the middle of tilting, the lock lever 29 can be immediately operated again to ensure that the lock lever 40 is engaged with the lock pin 42, or the lock lever 40 is not engaged with the lock pin 42. It is possible to confirm this.

Further, as described above, when the cargo box 9 is tilted, the front end of the lower frame L, which is tilted along with the cargo box 9, is connected to the fitting groove 53 of the elastic body 52 by the roller 51 of the third locking mechanism D. , and the front end of the lower frame L is elastically locked to the cargo box 9. Therefore, the lower frame L may wobble or the front end of the lower frame L may be bent against the cargo box 9. There is no sagging.

(Effects of the invention) As described above, the present invention provides a top rail on the cargo box, supports the rear part of the lower rail freely on the vehicle body stationary member, and pivots the pair of first and second arms in a crossed manner. , the lower end of the first arm is rotatably supported on the lower rail, the upper end of the first arm is movably connected to the upper rail, and the upper end of the second arm is connected to the cargo box side. The lower end of the second arm is movably connected to the lower rail, and the load box is selected relative to the vehicle body stationary member by locking or unlocking the lower rail with respect to the vehicle body stationary member. In the cargo box driving device for a transport vehicle, which is configured to tilt or raise and lower the cargo box, a lock lever that engages with the lower rail and locks the lower rail to the vehicle body stationary member is swingably supported on the vehicle body stationary member; The lower rail supports a locking lever that swings about the same axis as a swinging fulcrum of the lower rail relative to the vehicle body stationary member and engages the cargo box, and the locking lever is connected to the lock lever. The loading box is locked to the lower rail via the locking lever when the locking lever is switched to the locking operation, so even if the loading box is tilted, the position of the locking lever is Therefore, during the tilting of the cargo box, for example, when you want to check whether or not the locking lever is securely engaged with the cargo box, or when you want to check whether the locking lever is properly engaged with the cargo box, or when the lock lever is in the middle of tilting the cargo box. If the switching operation is incomplete and the locking lever is not securely engaged with the cargo box,
Immediately operate the lock lever again even if the cargo box is in the middle of inclination to ensure that the locking lever is engaged with the cargo box, or to confirm that the locking lever is engaged with the cargo box. This makes it possible to reliably prevent the cargo box from being inadvertently raised horizontally.

Moreover, according to the present invention, the locking lever is supported in a freely swinging manner with respect to the lower rail at a position whose fulcrum is approximately on the same axis as the swinging fulcrum of the lower rail with respect to the vehicle body stationary member. Although the locking lever is provided on the lower rail that swings relative to the vehicle body stationary member, the locking lever can be smoothly and reliably interlocked by operating the lock lever provided on the vehicle body stationary member.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of the cargo box raised horizontally, FIG. 2 is a perspective view of the cargo box tilted, and FIG. 3 is a perspective view of the cargo box tilted. Similarly, FIG. 4 is a side view of the second locking mechanism, FIG. 5 is a sectional view of the second locking mechanism,
Figure 6 is a perspective view of the elastic body of the second locking mechanism, Figure 7 is a sectional view of the automatic locking mechanism, Figures 8 and 9.
10 is a sectional view of the limit switch mounting portion of the detection mechanism, FIG. 11 is a perspective view of the speed change lock mechanism, and FIG.
The figure is an explanatory diagram of the operation of the speed change lock mechanism. 1... Chassis frame (vehicle body stationary member), 3
... Lower rail, 9 ... Loading box, 10 ... Upper rail, 11 ... First arm, 12 ... Second arm, 20 ... Hydraulic cylinder (lifting device), A ...
First locking mechanism (locking mechanism), C...first locking mechanism (locking mechanism).

Claims (1)

[Scope of utility model registration request] A top rail is provided in the cargo box, the rear part of the lower rail is rotatably supported on the vehicle body stationary member, and a pair of first and second arms are pivoted to cross each other, and the lower end of the first arm is attached to the lower rail. The first arm is rotatably supported, and the upper end of the first arm is movably connected to the upper rail.
The upper end of the arm is rotatably supported on the cargo box side, the lower end of the second arm is movably connected to the lower rail, and the lower rail is locked or unlocked from the vehicle body stationary member,
In the cargo box drive device for a transport vehicle, which selectively tilts or raises/lowers the cargo box with respect to a stationary member of the vehicle body, the stationary member of the vehicle body engages with the lower rail to lock the lower rail to the stationary vehicle body member. While the lock lever is supported to freely swing, the lower rail supports a locking lever that swings about the same axis as a swing fulcrum of the lower rail relative to the vehicle body stationary member and engages with the cargo box. Further, the locking lever is interlocked with the locking lever, so that when the locking lever is switched to a locking operation, the cargo box is locked to the lower rail via the locking lever. Cargo box drive device for transport vehicles.