JP4204910B2 - Retractable loading platform lifting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a retractable load receiving and lifting device configured such that the load receiving side is slidable back and forth along a guide rail between a retracted position below the load bed and a work position behind the load bed by extending and retracting a slide cylinder. is there.
[0002]
[Prior art]
Conventionally, a load receiving platform is provided on the loading platform via a link mechanism so as to be movable up and down, and the load receiving platform side including the link mechanism and the lifting mechanism is operated by a sliding cylinder extending and retracting the loading position below the loading platform and the work behind the loading platform. 2. Description of the Related Art A retractable cradle lifting device configured to be slidable back and forth along a guide rail between positions is provided (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-248984
[Problems to be solved by the invention]
By the way, in the case where the load receiving table side is slid by the expansion and contraction operation of the slide cylinder as in the conventional case, the load receiving table side is set to the storage position with the slide cylinder retracted to the stroke end. That is, since the slide cylinder has reached the stroke end, there is no escape space for the load receiving platform with respect to the loading platform.
[0005]
Therefore, when an obstacle collides with the load receiving table from behind due to the reverse of the vehicle, etc. with the load receiving table placed in the retracted position, this shock is received properly, thereby damaging the device and the vehicle body. There was a problem of inviting. This problem is particularly noticeable in a device having a bumper function on the load receiving side in the retracted state.
[0006]
[Means for Solving the Problems]
In the retractable load receiving device lifting apparatus according to the first aspect of the present invention, the load receiving platform is provided on the loading platform so as to be movable up and down by a lifting mechanism via a link mechanism, and the load receiving platform side including the link mechanism and the lifting mechanism is extended and contracted by a slide cylinder. In a retractable load receiving device lifting apparatus configured to slide back and forth along a guide rail between a retracted position below the loading platform and a working position behind the loading platform by operation, the slide cylinder is provided on the loading platform side. Cushion means for alleviating the acting impact is provided.
[0007]
According to a second aspect of the present invention, the cushion means is an elastic body provided at a base end portion in a cylinder body serving as a stroke end of a piston in the slide cylinder.
[0008]
According to a third aspect of the invention, the cushion means is provided with a throttle provided along with the elastic body in a return oil passage communicating with the oil tank from the piston side chamber of the cylinder body. It will be.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows the configuration of a retractable cargo receiving platform lifting apparatus according to the present invention.
[0011]
In FIG. 1, reference numeral 1 denotes a loading platform mounted on a vehicle body frame 11, and a retractable loading platform lifting device 2 is provided below the rear end of the loading platform 1.
[0012]
The retractable load receiving table lifting / lowering device 2 includes an attachment member 3 provided on the vehicle body frame 11 and a load receiving stand 5 provided on the attachment member 3 via a link mechanism 4.
[0013]
The attachment member 3 is slidable in the front-rear direction along an outward U-shaped guide rail 12 disposed in the front-rear direction at the rear end portion of the vehicle frame 11. Specifically, front and rear rollers (not shown) provided on the mounting member 3 are disposed so as to be able to roll in the guide rail 12, and the guide rail 12 is extended and retracted by the slide cylinder 6 described later. The entire retractable load receiving device lifting device 2 on the load receiving table 5 side is configured to be slidable back and forth below the floor surface of the loading table 1.
[0014]
The link mechanism 4 includes a lower link 41 and an upper link 42. The base ends of the lower link 41 and the upper link 42 are pivotally supported to the mounting member 3 side, and are moved up and down by, for example, a lifting cylinder 43 as a lifting means connected to the upper link 42 and the mounting member 3. It is configured to be freely rotatable.
[0015]
A pair of left and right members such as the guide rail 12, the mounting member 3, the link mechanism 4, and the elevating cylinder 43 described above are provided on both sides of the vehicle frame 11, so that the left and right mounting members 3 slide on the guide rail 12 in synchronization. Are connected by a connecting member 3a.
[0016]
The load receiving platform 5 includes a proximal deck 51, an intermediate deck 52, and a distal deck 53. The intermediate deck 52 is located above the proximal deck 51 via a hinge 54 with respect to the proximal deck 51. The front deck 53 is provided so as to be foldable with respect to the intermediate deck 52 via a hinge (not shown) and is foldable (below the intermediate deck 52 in the retracted state). That is, in the storage state shown in FIG. 1, the entire cargo receiving stand 5 is folded in three.
[0017]
And the front-end | tip part of the said up-and-down links 41 and 42 is pivotally supported by the said base end deck 51 via the bracket 55. FIG. Specifically, the tip portions of the left and right upper links 42 are pivotally supported on the upper portion of the bracket 55, and the tip portions of the left and right lower links 41 are pivotally supported on the lower portion of the bracket 55.
[0018]
Further, the tip of the tip deck 53 is formed in a wedge shape, and is tilted when the load receiving platform 5 reaches the ground, so that the tip is grounded to the ground without any step.
[0019]
The retractable load receiving device lifting / lowering device 2 configured as described above has a storage position in which the mounting member 3 is slid to the front end portion of the guide rail 12 with the load receiving stand 5 folded by the expansion / contraction operation of the slide cylinder 6 ( (See FIG. 1), and although not shown, the mounting member 3 is slid to the rear end of the guide rail 12 and the folded load receiving platform 5 is developed. In this expanded state, the load receiving platform 5 is placed on the ground and the floor surface of the loading platform 1. It can be arranged at a working position where it is moved up and down.
[0020]
In the slide cylinder 6 described above, the telescopic rod 61 is connected to the loading platform 1 on the fixed side, and the base end portion of the cylinder main body 62 (see FIG. 2) is coupled to the loading platform 5 on the sliding side. . The slide cylinder 6 is in a retracted state when placed in the retracted position shown in FIG. 1, and the load receiving platform 5 side is placed at the operating position by being extended. The slide cylinder 6 may be provided, for example, as a pair of left and right, or one in the center.
[0021]
Incidentally, the slide cylinder 6 is provided with cushion means. As shown in FIG. 2, the cushion means is constituted by a spring 7 as an elastic body provided at a base end portion in the cylinder main body 62. Specifically, the spring 7 is arranged at the base end portion of the cylinder body 62 so that the piston 63 is compressed when the telescopic rod 61 is retracted and the piston 63 reaches the stroke end.
[0022]
Accordingly, when the load receiving platform 5 side moves to the storage position side due to the retracting operation of the slide cylinder 6, the piston 63 abuts against the spring 7 to compress the spring 7, and the position where both forces are balanced is the storage position. As a result, the receiving platform 5 side is arranged.
[0023]
Next, the operation of the retractable load receiving table elevating device 2 configured as described above will be described.
[0024]
First, as shown in FIG. 1, in order to arrange the retractable load receiving table lifting device 2 from the storage position stored below the load carrier 1 to the working position, the slide cylinders 6 are respectively extended. By the extension operation of the slide cylinder 6, the entire retractable load receiving device lifting / lowering device 2 slides along the guide rail 12 toward the rear end side of the load carrier 1, thereby being arranged at the working position.
[0025]
Then, when the retractable load receiving device elevating device 2 is arranged at the working position in this way, although not shown, the intermediate deck 52 of the folded load receiving table 5 is rotated rearward together with the front end deck 53 so that the intermediate deck 52 Is deployed on the same horizontal plane as the proximal deck 51. Subsequently, the front end deck 53 is rotated backward, and the front end deck 53 is developed so as to be on the same horizontal plane as the base end deck 51 and the intermediate deck 52. As a result, the load receiving platform 5 can be moved up and down between the ground and the floor surface of the loading platform 1 by the lifting cylinder 43, and the loading and unloading work between the ground and the loading platform 1 through the load receiving platform 5 by this lifting operation. I do.
[0026]
Next, when the loading and unloading work is completed and the retractable load receiving device lifting / lowering device 2 is stored, the retractable load receiving device lifting / lowering device 2 is arranged from the working position to the retracted position by the reverse operation to the operation described above. . That is, at the work position, after placing the load receiving platform 5 of the retractable load receiving platform lifting / lowering device 2 at a predetermined height, the load receiving platform 5 is folded in three, and the slide cylinder 6 is retracted in this state. Due to the retracting operation of the slide cylinder 6, the entire retractable load receiving device lifting device 2 slides along the guide rails 12 below the load carrier 1, and is disposed at the retracted position as shown in FIG.
[0027]
Here, in the state where the load receiving platform 5 is arranged at the retracted position as described above, when an obstacle A collides with the load receiving platform 5 from behind due to the reverse of the vehicle or the like, a spring 7 is interposed in the slide cylinder 6. Therefore, the telescopic rod 61 is retracted by the amount that the piston 63 compresses and moves the spring 7 against the urging force, and the load receiving platform 5 is also attached to the vehicle as the telescopic rod 61 retracts. It moves forward (see FIG. 3).
[0028]
Thereby, the impact when the obstacle A collides with the load receiving platform 5 from behind can be absorbed by the buffering effect of the spring 7, and damage to the apparatus and the vehicle body can be kept to a minimum.
[0029]
Further, as shown in FIG. 2, a throttle 65 is provided in the return oil passage 64 communicating with the oil tank T from the piston side chamber 62 a of the cylinder body 62, and the throttle 65 returns from the piston side chamber 62 a to the oil tank T. By squeezing the oil, it is possible to further enhance the shock-absorbing effect against the impact, and further prevent damage to the device and the vehicle body due to the impact.
[0030]
【The invention's effect】
As described above, according to the retractable load receiving device lifting apparatus of the present invention, the cushion means is provided on the slide cylinder, so that the shock when the obstacle collides with the load receiving device from the rear is cushioned. By this, damage to the device and the vehicle body can be minimized.
[Brief description of the drawings]
FIG. 1 is a side view showing a retractable load receiving device lifting apparatus according to the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a slide cylinder.
FIG. 3 is a side view showing the retractable load receiving device lifting device in a state where an obstacle collides with the load receiving device from behind.
[Explanation of symbols]
1 Loading platform 12 Guide rail 4 Link mechanism 43 Lifting cylinder (lifting means)
5 Carriage 6 Slide cylinder 62 Cylinder body 62a Piston side chamber 63 Piston 64 Return oil passage 65 Restriction 7 Spring (elastic body)
T Oil tank

Claims (3)

A load receiving platform is provided on the loading platform via a link mechanism so as to be movable up and down by lifting means, and the loading platform side including the link mechanism and the lifting means is retracted by a sliding cylinder to a retracted position below the loading platform and a working position behind the loading platform. In the retractable cradle lifting device configured to be slidable back and forth along the guide rail between
2. A retractable load receiving device lifting apparatus according to claim 1, wherein the slide cylinder is provided with cushion means for reducing an impact acting on the load receiving side. The retractable load receiving device lifting / lowering apparatus according to claim 1, wherein the cushion means is an elastic body provided at a base end portion in a cylinder main body which is a stroke end of a piston in a slide cylinder. 3. The retractable cradle according to claim 2, wherein the cushion means is provided with a throttle provided in a return oil passage communicating with an oil tank from a piston side chamber of the cylinder body together with the elastic body. lift device.

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