JP4275294B2 - Lowering prevention device in retractable cargo receiving platform lifting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a retractable load receiving device lifting device in which a load receiving plate provided on a load carrier so as to be movable up and down via a link mechanism can be slid and stored below the load carrier. The present invention relates to a descent prevention device that prevents the descent of descent.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as shown in Japanese Patent Application Laid-Open No. 11-5484, a retractable load receiving device elevating device operates a stopper by operating an operation device and prevents the link mechanism from being lowered by this stopper. There is provided a device for stopping the table or the like at the storage height position and holding the load receiving table or the like at the storage height position to prevent the descent.
[0003]
[Problems to be solved by the invention]
However, since the stopper is operated by the operator manually operating the operating device in the above-described conventional device, the above operation must be performed each time when the load receiving table is stored, which is troublesome. As a result, the manual operation may lead to an erroneous operation, and this erroneous operation may stop at the storage height position during the lifting operation, and conversely, it may not stop at the storage height position during storage. There was a problem that interfered with the work.
[0004]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a descent prevention device for a retractable load receiving device lifting apparatus, wherein the load receiving table is provided so as to be movable up and down via a link mechanism having two upper and lower upper links and a lower link. In a retractable load receiving device lifting device configured to be able to be stored by being slid to the storage position below the load carrier in a state where the load carrier is folded back and forth, a position higher than the storage height position in the state in which the load carrier is folded when it dropped from one in which the block the descent of the link mechanism stored in a vertical position by lowering prevention device that prevents the drop from the position is provided.
[0005]
According to a second aspect of the present invention, the descent prevention device according to the second aspect of the invention is provided with the descent prevention device when the descent prevention device is lowered from a position higher than the storage height position in the folded state of the freight receiving table. And an operation lever that operates in contact with the operation lever, and a stopper that is disposed from the retracted position to the contact position in conjunction with the operation of the operation lever and prevents the link mechanism from being lowered at the retracted height position. is there.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0007]
First, in describing the lowering prevention device in the retractable load receiving device lifting apparatus according to the present invention, the configuration of the retractable load receiving device lifting device provided with this lowering prevention device will be described.
[0008]
FIG. 1 shows an overall schematic configuration of the retractable load receiving table lifting device.
[0009]
In FIG. 1, reference numeral 1 denotes a loading platform mounted on a vehicle frame 11, and a retractable loading platform elevating device 2 is provided below the rear end of the loading platform 1.
[0010]
The retractable load receiving table lifting / lowering device 2 includes an attachment member 3 provided on the vehicle frame 11 and a load receiving stand 5 provided on the attachment member 3 via a link mechanism 4.
[0011]
The mounting member 3 is slidable in the front-rear direction along an outward U-shaped slide rail 12 disposed in the front-rear direction at the rear end of the vehicle frame 11. Specifically, the front and rear rollers 31, 31 provided above the mounting member 3 are disposed so as to be able to roll within the slide rail 12, and the mounting member 3 can be moved manually or by an appropriate moving means. 12, the entire retractable load receiving device lifting device 2 is configured to be movable back and forth below the floor surface of the load carrier 1.
[0012]
As an example of the moving means, a chain 13 is stretched back and forth along the slide rail 12 at the lower portion of the slide rail 12, and a sprocket 32 that engages the chain 13 from below is provided on the mounting member 3. The attachment member 3 is moved back and forth by rotating the sprocket 32 in the forward / reverse direction via an appropriate transmission mechanism by a drive motor (not shown). In addition, as a moving means, you may make it move the attachment member 3 back and forth using actuators, such as a cylinder, an operation handle, etc. other than said structure.
[0013]
A drive shaft 6 is supported on the mounting member 3 substantially horizontally. A base end portion of a drive arm 61 is integrally fixed to the drive shaft 6, and a distal end of a telescopic rod 62 a of a lift cylinder 62 provided on the mounting member 3 is connected to the distal end portion of the drive arm 61.
[0014]
Further, the drive shaft 6 is integrally provided with a base end portion of a rotation bracket 63, and a base end portion of a lift link 41 described later is pivotally supported at an intermediate portion of the rotation bracket 63.
[0015]
The link mechanism 4 includes a lift link 41 as a lower link and a connecting link 42 as an upper link.
[0016]
The lift link 41 has a base end portion pivotally supported by a pivot 41 a in the middle of the rotating bracket 63.
[0017]
A contact bolt 64 provided at the distal end of the rotating bracket 63 is configured to be able to contact the lower surface of the lift link 41 near the base end portion. By abutting on the part closer to the end from below, the expansion / contraction operation of the lift cylinder 62 can be transmitted to the lift link 41 as the rotation operation of the rotation bracket 63 via the drive arm 61 and the drive shaft 6. As a result, the lift link 41 rotates up and down.
[0018]
The base end of the connecting link 42 is pivotally supported on the mounting member 3 by a pivot 42a.
[0019]
A pair of left and right members such as the slide rail 12, the mounting member 3, the link mechanism 4, and the drive shaft 6 described above are provided on both sides of the vehicle frame 11, and the left and right mounting members 3 slide in synchronization with the slide rail 12. Are connected to each other by a connecting member 3a.
[0020]
The load receiving platform 5 includes a distal end side member 51 and a proximal end side member 52, and the distal end side member 51 and the proximal end side member 52 are separated from each other by an upper hinge 53. The upper surface of 52 can be folded in two.
[0021]
On the left and right sides of the base end portion of the base end side member 52, the tip ends of the left and right connecting links 42 are pivotally supported by pivots 42 b on the upper portions thereof via brackets 54, and the tips of the left and right lift links 41 are located below the lower ends. The part is pivotally supported by the pivot 41b.
[0022]
Further, the tip of the front end side member 51 is formed in a wedge shape, and when the load receiving platform 5 reaches the ground, it tilts as shown by a one-dot chain line in FIG. Has been made.
[0023]
The retractable load receiving device elevating device 2 is stored at the storage position (FIG. 2) in which the mounting member 3 is slid to the foremost end of the slide rail 12 with the load receiving stand 5 folded by the operation of the moving means described above. Reference) A and the load receiving base 5 that is folded by sliding the mounting member 3 to the rear end portion of the slide rail 12 are expanded so that the distal end side member 51 and the proximal end side member 52 are horizontal, and the unfolded state. The unfolding / folding position (see FIG. 3) B where the loading platform 5 is folded, and the loading platform 5 in a state where the mounting member 3 is slid to the midway position of the slide rail 12 and deployed are placed between the ground and the floor surface of the loading platform 1. It can be arranged at a lifting work position (see FIG. 1) C that is lifted up and down.
[0024]
The retractable load receiving device lifting / lowering device 2 configured as described above is configured to prevent the lowering by preventing the lowering when the load receiving stand 5 and the link mechanism 4 reach the storage height position. A descent prevention device 7 which is a main part is provided.
[0025]
As shown in FIG. 4, the descent prevention device 7 includes an operating lever 71 and a stopper 74 that is interlocked with the operation of the operating lever 71.
[0026]
The actuating lever 71 is pivotally supported on the mounting member 3 by a pin 71a arranged on the same axis as the pivot 42a of the base end of the connecting link 42, and is provided at one end on the rear side of the loading platform 1. A roller 72 is provided, and the upper end portion of the connecting rod 73 is pivotally supported at the other end portion by a pin 73a.
[0027]
When the roller 72 is disposed at the unfolding / folding position B shown in FIGS. 3 and 4, the roller 72 is disposed so as to protrude rearward from the rear end of the loading platform 1, and the distal end of the folded front end member 51 of the loading platform 5. It is made to contact with.
[0028]
As shown in FIG. 5, a block-like bush 75 provided at the base end of the stopper 74 is rotatably supported by the mounting member 3 by a pin 75a. The lower end of the connecting rod 73 is pivotally supported by a pin 73b.
[0029]
The stopper 74 is provided opposite to the lower end of the base end of the connecting link 42. As shown by the solid line in FIG. 4, the stopper 74 is disposed at the retracted position when the operating lever 71 is disposed at one end. 4, in a state where the operating lever 71 is disposed at one end downward as indicated by a two-dot chain line, the distal end portion 74 a is disposed at a contact position where the distal end portion 74 a contacts the lower portion of the base end portion of the connecting link 42. Has been made.
[0030]
A spring 77 is connected to the mounting member 3 and the other end of the operating lever 71. The spring 77 biases the operating lever 71 upward.
[0031]
Reference numeral 78 in FIG. 5 is a plate for retaining the pin 75a.
[0032]
Next, the operation of the above-described retractable load receiving table lifting device will be described together with the operation of the lowering prevention device 7.
[0033]
First, when the cargo loading / unloading operation is performed by the retractable load receiving device elevating device 2 arranged at the storage position A as shown in FIG. 2, the mounting member 3 is moved from the front end portion of the slide rail 12 to the rear end portion. By sliding, the retractable load receiving table elevating device 2 is disposed at the unfolding / folding position B shown in FIG.
[0034]
Subsequently, the distal end side member 51 of the load receiving platform 5 folded at the unfolding / folding position B is rotated rearward so that the proximal end side member 52 and the distal end side member 51 are deployed horizontally. Thereafter, the mounting member 3 is slid forward from the rear end portion of the slide rail 12 and placed at the lifting / lowering operation position C shown in FIG. As a result, the load receiving platform 5 can move up and down between the ground and the floor of the loading platform 1 by the expansion and contraction operation of the lift cylinder 62, and the lifting and lowering operation allows the load receiving platform 5 to move between the ground and the loading platform 1 through the load receiving platform 5. Perform unloading work.
[0035]
When the loading / unloading operation of the load is completed and the retractable load receiving device lifting / lowering device 2 is stored, the retractable load receiving device lifting / lowering device 2 is temporarily arranged from the lifting / lowering operation position C to the unfolding / folding position B. At this time, the load receiving platform 5 and the link mechanism 4 are disposed slightly above the storage height position (refer to FIG. 3) where the mounting member 3 is slid to store, and in this state, the front end side of the load receiving platform 5 After the member 51 is folded, the receiving platform 5 is lowered.
[0036]
When the load receiving platform 5 is lowered in this manner, the front end side member 51 folded of the load receiving platform 5 is shown as shown by a solid line in FIG. 4 before the load receiving platform 5 and the link mechanism 4 reach the storage height position. The tip abuts against the roller 72 of the operating lever 71 from above.
[0037]
Further, when the load receiving platform 5 is further lowered, one end of the operating lever 71 is rotated downward, and the rotation of the operating lever 71 causes the stopper 74 to be disposed from the retracted position to the contact position. When the mechanism 4 reaches the retracted height position (see the chain line state in FIGS. 3 and 4), the lower part of the base end portion of the connecting link 42 comes into contact with the tip end portion 74a of the stopper 74, and the lowering of the link mechanism 4 is prevented. The As a result, the load receiving platform 5 and the link mechanism 4 are held at the storage height position. In this state, the mounting member 3 is slid from the rear end portion of the slide rail 12 to the front end portion, so that the retractable load receiving device lifting device 2 is stored at the storage position A. To be placed.
[0038]
In this way, the weight of the load receiving platform 5 and the connecting link 42 acts on the stopper 74 arranged at the storage position A, so that the stopper 74 can be stably prevented from coming off from below the base end portion of the connecting link 42. Since it supports, it can prevent reliably that the load receiving stand 5 and the link mechanism 4 descend | fall carelessly during driving | running | working.
[0039]
That is, when storing the retractable load receiving table elevating device 2, the load receiving stand 5 is folded, so that the operating lever 71 is operated using this state to dispose the stopper 74 at the contact position, thereby connecting The descent of the link 42 is forcibly prevented at the storage height position, and the descent from this position is prevented.
[0040]
For this reason, when storing the retractable cargo receiver lifting device 2, it is not necessary to perform a separate operation for storage as in the prior art, and can be performed automatically in accordance with the above-described storage operation. It is simplified and has good operability, and it is easy to operate without misoperation.
[0041]
When the lifting operation of the retractable load receiving table 2 is performed, the load receiving stand 5 is deployed horizontally, so that it does not come into contact with the roller 72 of the operating lever 71. In this state, the operating lever 71 is a spring. The stopper 74 is disposed at the retracted position by being lifted at one end by the urging force of 77. For this reason, the stopper 74 does not come into contact with the connecting link 42, and the lifting operation of the load receiving platform 5 is not hindered.
[0042]
Further, the loading / unloading platform 5 is unfolded or folded by placing the retractable loading platform lifting / lowering device 2 at the unfolding / folding position B so that the entire loading platform 5 is pulled out behind the loading platform 1 and the vehicle frame 11. Therefore, even if the loading platform 5 is expanded or folded at this position, the loading platform 5 does not interfere with the loading platform 1 and the vehicle frame 11.
[0043]
In the present embodiment, the lift link 41 as the lower link is transmitted and rotated by the lift cylinder 62 to rotate and thereby lift the load receiving platform 5. However, the lifting drive of the load receiving platform 5 has been described. The mechanism is not limited to this, and it may be carried on the connecting link 42 side as the upper link, and the driving source for rotating the lower link and the upper link is not limited to this.
[0044]
【The invention's effect】
As described above, according to the lowering prevention device in the retractable load receiving device lifting apparatus of the present invention, the lowering of the link mechanism is prevented at the storage height position by using the folded state of the load receiving table. By preventing the descent, when storing the retractable load receiving device, there is no need to perform a separate storage operation as in the past, and it can be automatically performed along with the storage operation. Is simplified, the operability is good, the operability is good without any erroneous operation, and the lowering of the cargo cradle can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a side view showing a state in which a retractable cargo receiving table lifting device is disposed at a lifting work position.
FIG. 2 is a side view showing a state in which the retractable cargo receiving platform lifting device is also disposed at the retracted position.
FIG. 3 is a side view showing a state in which the retractable load receiving table lifting device is also disposed at the unfolded / folded position.
FIG. 4 is an enlarged side view showing a configuration of a descent prevention device in the retractable cargo receiving table elevating device of the present invention.
5 is a diagram in which a part of the arrow A in FIG. 4 is cut away.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Loading platform 2 Retractable loading platform lifting device 3 Mounting member 4 Link mechanism 41 Lift link (downward link)
42 Link (Uplink)
5 Loading platform 7 Lowering prevention device 71 Actuating lever 74 Stopper A Storage position

Claims (2)

The loading platform is provided on the loading platform through a link mechanism having two upper and lower upper links and a lower link. The loading platform can be moved up and down, and the loading platform is folded back and forth to slide to the storage position below the loading platform. In the retractable load receiving and lifting device configured to be capable of preventing the link mechanism from being lowered at the retracted height position when the load receiving stand is lowered from a position higher than the retracted height position in the folded state. A descent prevention device for a retractable cargo receiver elevating device, wherein a descent prevention device for preventing descent from a lever position is provided. The drop prevention device includes an actuating lever that operates the receiving platform is folded in when dropped from a position higher than the storage height position while the receiving platform and in contact, in conjunction with the operation of the actuating lever 2. The apparatus for preventing a descent in a retractable load receiving apparatus according to claim 1 , further comprising a stopper that is disposed from the retracted position to the contact position and blocks the descent of the link mechanism at the retracted height position.

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