JPH0439073Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention relates to a loading platform elevating device in a cargo handling vehicle.

<Conventional technology> Conventionally, the third type of loading/unloading platform elevating device
There is something like the one shown in the figure. This loading platform elevating device has a support frame 32 disposed at the rear end of a cargo handling vehicle 31 so that it can be raised and lowered by a hydraulic cylinder 35 via a parallel link mechanism 33. The support frame 32 has a cargo receiving platform 36 pivotally attached to its lower end so that it can be raised and lowered, and also supports the cargo receiving platform 36 in a state where the cargo receiving platform 36 is laid down.
7 to support it horizontally. Further, a coupling pin 38 is fixed to the upper part of the cargo receiving platform 36, and after the cargo receiving platform 36 is erected, the coupling pin 38 is secured to a lashing device 40 fixed to the rear upper end of the cargo handling vehicle 31. I try to tie it down.

The hydraulic cylinder 35 is driven by a hydraulic circuit shown in FIG. That is, when oil is supplied to the hydraulic cylinder 35 by the hydraulic pump 41 via the check valve 42, the cylinder extends and the support frame 32 rises. At this time, the oil is released to the tank 44 by the relief valve 43 to prevent more than necessary hydraulic pressure from being applied to the hydraulic cylinder 35. On the other hand, when lowering the support frame 32, the switching valve 45
is switched to the conducting side, and the oil supplied to the hydraulic cylinder 35 is released to the tank 44 via this switching valve 45. Then, the hydraulic cylinder 35 is contracted and the support frame 32 is lowered.

Further, as shown in FIG.
A receiving fitting 52 having a letter-shaped engagement hole 51 and a receiving fitting 52 rotatably held by the receiving fitting 52, and the coupling pin 3
8 and a rotating metal fitting 54 having a U-shaped engagement hole 53 that engages with the receiving metal fitting 52 and the rotating metal fitting 54.
The connecting pin 38 is secured by the . An operating lever 55 is attached to the rotating metal fitting 54, and by operating the operating lever 55 to rotate the rotating metal fitting 54, the engagement hole 55 of the receiving metal fitting 52 is opened.
1 is opened and closed.

After rotating the rotary fitting 54 in the direction of the arrow a to open the engagement hole 51 of the receiving metal fitting 52, when the load receiving platform 36 is pulled toward the rear side of the cargo handling vehicle 31, the coupling pin 38 is inserted through the engagement hole 51. It can be detached and the loading platform 36 can be laid down horizontally as shown in FIG. 3A. next,
When the switching valve 45 shown in FIG. 4 is switched to the conducting side, the hydraulic cylinder 35 is retracted, the parallel link mechanism 33 is rotated, and the support frame 32 is lowered to the position shown in FIG. 3B together with the fallen cargo platform 36. . At this lowered position, cargo is loaded and unloaded.

<Problems to be solved by the invention> However, the above-mentioned conventional cargo platform lifting device has the following problems:
Due to poor pressure resistance of the hydraulic cylinder 35 or damage to the hydraulic piping, the hydraulic cylinder 3
When the supporting force of the lashing device 5 is running out, the lashing device 4
When 0 is opened, the connecting pin 38 separates from the lashing device 40, causing the cargo receiving platform 36 to suddenly descend together with the support frame 32, which is dangerous and can injure workers.

Therefore, the purpose of this invention is to provide a loading platform elevating device in which the loading platform will not fall accidentally even if the lashing device is released when the supporting force of the hydraulic cylinder for the loading platform is lost as described above. There is a particular thing.

<Means for Solving the Problems> In order to achieve the above object, this invention arranges a support frame at the rear end of a cargo handling vehicle so that it can be raised and lowered by a fluid cylinder via a parallel link mechanism, and A loading platform is pivotally attached to the lower end of the loading platform, while a connecting pin fixed to the upper part of the loading platform is connected to a U-shaped locking pin that is fixed to the rear upper end of the cargo handling vehicle and inserted from the opening of the connecting pin. In the load receiving platform elevating device configured to be secured by a receiving metal fitting having a mating hole and a rotating metal fitting rotatably connected to the receiving metal fitting and opening and closing an opening of the engaging hole, the connecting pin may be secured. A recessed portion is provided on the lower surface of the engagement hole of the receiving fitting, into which the coupling pin is retracted and locked when the fluid cylinder loses its supporting force with respect to the cargo receiving platform in the loaded state. .

<Function> A connecting pin fixed to the upper part of the loading platform is inserted through the opening of a U-shaped engagement hole of a receiving fitting fixed to the rear upper end of the cargo handling vehicle, and is rotatably connected to the receiving fitting. The cargo receiver of the fluid cylinder that raises and lowers the support frame, which has the cargo receiver platform movably pivotally attached to the lower end of the cargo handling vehicle via a parallel link mechanism, in a state where it is secured by a rotating metal fitting and the receiving metal fitting. When the supporting force for the platform is lost due to a failure or the like, the coupling pin descends together with the cargo receiving platform, and the recessed portion provided on the lower surface of the engagement hole of the receiving metal fitting locks the coupling pin. Therefore, even if the rotary fitting is rotated to release the fastening to the coupling pin, the coupling pin will not be disengaged from the engagement hole, and the cargo receiving platform will not fall erroneously.

<Example> Hereinafter, this invention will be explained in detail with reference to the illustrated example.

The cargo platform elevating device of this embodiment uses a first lashing device instead of the lashing device 40 of the conventional cargo platform elevating device shown in FIG.
The lashing device shown in the figure is used, and everything else other than the lashing device is the same as the conventional example.

In FIG. 1, reference numeral 1 is fixed to the rear upper end of a cargo handling vehicle 31, and includes a U-shaped engagement hole 2 into which a coupling pin 38 is inserted, and a U-shaped engagement hole 2 provided on the lower surface of this engagement hole 2 into which the coupling pin 38 is inserted. A receiving fitting 5 having a recessed portion 3 that is locked is rotatably held by the receiving fitting 1, and has a U-shaped engagement hole 6 that engages with the coupling pin 38, and has a U-shaped engagement hole 6 that engages the coupling pin 38. This is a rotating metal fitting that opens and closes the engagement hole 2 of the receiving metal fitting. An operating lever 7 is attached to the rotating metal fitting 5, and the rotating metal fitting 5 is rotated by operating the operating lever 7. Further, a recess 8 is provided on the outer periphery of the rotating metal fitting 5, and a spherical locking member 9 fitted into the receiving metal fitting 1 is biased inwardly by a spring 10.
The rotary fitting 5 is engaged with the rotary fitting 5 to prevent rotation thereof. The rotating metal fitting 5 is locked by the locking member 9 with the engagement hole 2 of the receiving metal fitting 1 closed.

When the coupling pin 38 is locked between the receiving fitting 1 and the rotary fitting 5, the pressure resistance of the hydraulic cylinder 35 may be poor, the hydraulic piping may be damaged, and the supporting force of the hydraulic cylinder 35 against the loading platform 36 may be lost. Then, the loading platform 36 moves downward together with the support frame 32, and the coupling pin 38 fixed to the loading platform 36 is locked in the recessed portion 3 of the receiving bracket 1, as shown in FIG. Therefore, even if the rotary fitting 5 is rotated, it will not be locked by the coupling pin 38 during rotation and open the engagement hole 2 of the receiving fitting 1, and the loading platform 36 will not be pulled to the rear of the cargo handling vehicle 31. Even if the connecting pin 38 is connected to the bracket 1
Since it does not disengage from the engagement hole 2, the cargo receiving platform 36 does not descend.

In this way, the recessed part 3 is provided on the lower surface of the engagement hole 2 of the receiving metal fitting, so that when the supporting force of the hydraulic cylinder 35 to the cargo receiving platform 36 is lost with the coupling pin 38 being secured, the coupling pin 38 can be fixed. 38 is the immersion part 3
Since it is designed to be immersed in and locked, the loading platform does not fall down and is safe.

In the above embodiment, the engagement hole 2 of the receiving metal fitting 1 is
is opened and closed by a rotating metal fitting 5 which is rotatably held by the receiving metal fitting 1 and has a U-shaped engagement hole, but it is also possible to open and close the rotating metal fitting 5 with a U-shaped engagement hole, which is rotatably held by the receiving metal fitting 1. It may be opened and closed.

<Effects of the Invention> As is clear from the above, the loading platform lifting device of this invention has a coupling pin fixed to the top of the loading platform,
The fluid cylinder, which is inserted through the opening of a U-shaped engaging hole in a receiving bracket fixed to the upper rear end of a loading vehicle and fastened together with a rotating bracket rotatably connected to the receiving bracket and which raises and lowers a support frame whose lower end is pivotally attached to the receiving bracket via a parallel link mechanism at the rear end of the loading vehicle, is designed to lose its support force against the receiving bracket due to a malfunction or the like, so that a recessed portion provided on the underside of the engaging hole in the receiving bracket engages the connecting pin, thereby preventing the receiving bracket from accidentally falling even if the fastening is released if the fluid cylinder or the like malfunctions, and therefore safety is assured.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a state in which the lashing device in one embodiment of the loading platform elevating device of this invention has secured the coupling pin, and Fig. 2 shows the recessed portion of the engagement hole of the receiving fitting of the lashing device. A diagram showing the state in which the coupling pin is recessed and locked, FIG. 3 is a diagram showing a general loading platform lifting device, and FIG. 4 is a diagram showing the hydraulic pressure that drives the hydraulic cylinder of the general loading platform lifting device. FIG. 5, which is a circuit diagram, is a diagram showing a state in which a conventional lashing device has secured a coupling pin. 1...Bracket fitting, 2...Engagement hole, 3...Recessed part,
5... Rotating metal fitting, 31... Cargo handling vehicle, 32... Support frame, 33... Parallel link mechanism, 35... Hydraulic cylinder, 36... Loading platform, 38... Connection pin, 4
0... lashing device.

Claims (1)

[Scope of Claim for Utility Model Registration] A support frame is arranged at the rear end of a cargo handling vehicle so that it can be raised and lowered by a fluid cylinder via a parallel link mechanism,
A loading platform is pivotally attached to the lower end of the support frame so that it can be raised and lowered freely, while a connecting pin fixed to the upper part of the loading loading platform is
a receiving metal fitting fixed to the rear upper end of the cargo handling vehicle and having a U-shaped coupling hole into which the coupling pin is inserted through the opening; and a receiving metal fitting rotatably connected to the receiving metal fitting;
In a loading platform elevating device in which the opening of the engagement hole is secured with a rotary fitting that opens and closes, when the supporting force of the fluid cylinder against the loading platform is lost with the connecting pin secured. A loading platform lifting device characterized in that a recessed portion into which the coupling pin is recessed and locked is provided on the lower surface of the engagement hole of the receiving metal fitting.