JPH0431163Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is a loading platform lifting device used when loading and unloading cargo into a shipping box, and in particular, a loading platform (hereinafter referred to as a tailgate) that can be moved horizontally and tilted. Concerning forced cams that control the state.

(Prior Art) Conventionally, as shown in FIG. 8, in a loading platform elevating device for a cargo handling vehicle, a rotating shaft c is pivotally supported by a frame b fixed to both left and right sides of the rear of a vehicle body frame a. A rotating plate d is fixed to both ends of the shaft c. The base end of a tension link e is rotatably supported on the frame b by a pin h, and the base end of a lift arm f is rotatably supported on a rotary plate d. The tip of the lift arm f is rotatably supported by the lower end of the vertical arm g, while the tip of the tension link e is rotatably supported by the upper end of the vertical arm g. Therefore, the rotating plate d, tension link e, lift arm f, and vertical arm g constitute a parallel link mechanism. Furthermore, a forced cam k is rotatably supported on the rotary plate d by a pin n, and the upper surface of this forced cam k comes into contact with a guide roller i provided at the tip of the pin h, and the tip m can be engaged with and detached from a restraining member p fixed to the upper surface of the lift arm f. The members configured as described above are provided symmetrically on both left and right sides at the rear of the vehicle body frame a. The base end of the tailgate l is pivotally supported by vertical arms g, g, and the rotation shaft c is rotated via a rotating arm (not shown) by the expansion and contraction of an elevating cylinder (not shown), and the link mechanism is rotated. It is made to move up and down by moving it. When the tailgate l moves up and down from just before the ground level to the height of the cargo box floor, the tip m of the forced cam k
is engaged with the restraining member p, so the tailgate l maintains a horizontal state and moves up and down. In addition, when the tailgate l reaches the ground surface, the forced cam k
The tip m of the lift arm was detached from the restraining member p, and the tailgate l was tilted due to the interaction between the lift arm f further rotating due to the rotation of the rotation axis c and the weight of the tailgate l. .

(Problem that the invention aims to solve) However, many of the various cargo handling vehicles have different loading platform heights, and the loading platform lifting device installed on these cargo handling vehicles is designed to adapt to the height of the loading platform of the cargo handling vehicle. It is necessary to adjust the lifting stroke (distance from when the tailgate descends from the height of the loading platform to when it tilts), and adjusting the lifting stroke will speed up or slow down the timing at which the forced cam and the restraining member separate. It is being done by hand. In other words, the timing of engagement and disengagement with the restraining member is adjusted by means of forced cams formed by changing the extension angle of the tips to obtain a lifting stroke that adapts to the height of the loading platform of the cargo handling vehicle. . For this reason, a plurality of forced cams are required, each of which is adapted to a variety of cargo handling vehicles with different loading platform heights, resulting in the problem of an increase in the number of parts.

(Means for Solving the Problems) The loading platform elevating device for a cargo handling vehicle of the present invention pivots the base end of a tension link and a rotary plate to a frame fixed to the rear of the vehicle body frame, and A parallel link mechanism is formed to pivotally support the base end of the lift arm and to pivotally support the load receiving platform via the tension link and the vertical arm at the tip of the lift arm, and a forced cam is pivotally supported to the rotary plate. In a loading platform lifting device in which a lift arm is provided with a restraining member that can be engaged with and detached from the forcible cam, the forcible cam includes a guide member whose upper surface abuts a guide roller, and an engagement member that engages and disengages from the restraining member. The guide member is provided with a fitting hole into which a pin for rotatably supporting the rotary plate is fitted, and a plurality of fixing parts are provided at predetermined intervals from the fitting hole, and on the other hand, The engagement member is formed with a fitting hole into which a pin for rotatably supporting the rotary plate together with the guide member is fitted, and a fitting hole is formed in which a pin is fitted for rotatably supporting the rotating plate together with the guide member. One or more fixed parts are fixed together with the fixing means by a fixing means, and by changing the fixing position of the fixed part and the fixed part by the fixing means, the extension angle of the engaging member with respect to the guide member can be adjusted. It is configured to be able to change the angle.

(Function) The forced cam 20 is connected to the guide member 21 and the engagement member 30.
The extension angle of the engaging member 30 with respect to the guide member 21 can be varied by appropriate fixing means. Therefore, when installing a loading platform lifting device on various cargo handling vehicles with different loading platform heights,
This forced cam 20, in which the extension angle of the engaging member 21 is set at any time, is attached to the loading platform lifting device so that the lifting stroke of the loading platform lifting device can be obtained that is suitable for the loading platform height of the cargo handling vehicle. The timing at which the cam 20 and the restraining member 12 engage and disengage is adjusted.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the loading platform elevating device includes a link mechanism formed symmetrically on a frame 4 fixed to the rear of a vehicle body frame 1, and a drive device for driving these link mechanisms. The tailgate 11, which is pivotally supported on the
1 is designed to tilt when it reaches the ground surface.

A rotating shaft 2 is attached to a frame 4 fixed to the rear of the vehicle body frame.
is horizontally supported, and rotating plates 3 are fixed to both ends of the rotating shaft 2, respectively. The base end of the tension link 7 is rotatably supported on the frame 4 by a pin 6, and the base end of the lift arm 5 is rotatably supported on the rotary plate 3 by a pin 8. There is. The tip of the tension link 7 is rotatably supported by the upper end of the vertical arm 10, and the tip of the lift arm 5 is rotatably supported by the lower end of the vertical arm 10. Therefore, the lift arm 5, tension link 7, vertical arm 10, and rotating plate 3 constitute a parallel link mechanism. Further, as a drive device for driving the link mechanism, an elevating cylinder (not shown) is provided on the frame 4, and a rod end of this elevating cylinder is connected to the rotating shaft 2 via a rotating arm (not shown). The base end of a tailgate 11 is rotatably supported by the vertical arm 10, and when opened, the tailgate 11 is moved vertically to the vertical arm 10 (horizontal to the ground surface) by an appropriate means. It is designed to be supported. Furthermore, a lift arm 5 is attached to the rotating plate 3.
A force cam 20 is rotatably supported by a pin 13 and is detachable from a restraining member 12 fixed to the upper surface near the proximal end. Number 16 in the diagram
17 is a spring that urges the tip of the forced cam 20 in a direction to engage with the restraining member 12, and 17 is a contact member that comes into contact with the lower surface of the lift arm 5 and transmits the movement of the rotary plate 3 to the lift arm 5.

In the cargo platform elevating device constructed in this way, the rotating shaft 2 is rotated as the elevating cylinder expands and contracts, thereby driving the link mechanism and causing the tailgate 11 to move up and down. When the tailgate 11 moves up and down from just before the ground level to the height of the cargo box floor, the forced cam 20 and the restraining member 1
As a result, the tailgate 11, which is pivotally supported by the vertical arm 10, maintains a horizontal state and moves up and down. Also tailgate 1
1 reaches the ground surface, the forced cam 20 and the restraining member 12 are separated, and due to the further rotation of the lift arm 5 and the interaction with the tailgate 11's own weight, the tailgate 11 is tilts so that it touches the ground.

As shown in FIGS. 2 to 4, the forced cam 20 consists of a guide member 21 and an engagement member 30,
It is formed by connecting and fixing both using appropriate fixing means.

A fitting hole 25 into which a pin 13 for rotatably supporting the guide member 21 on the rotary plate 3 is fitted is provided approximately at the center of the lower surface of the guide member 21, and the upper surface 23 of this guide member 21 is provided with a tensioner. It is designed to come into contact with a guide roller 15 provided at the tip of a pin 6 that supports the link. moreover,
Near one end of the guide member 21, two through holes whose centers are located on the same circumference around the insertion hole 25 are vertically provided, and the upper through hole is connected to a first through hole (a fixed part) 26, the through hole provided below is a third through hole (fixed part) 28. Further, a second through hole (fixed part) 27 is provided further toward one end than the first through hole 26 and the third through hole 28, and the center of the second through hole 27 is the center of the insertion hole 25 and the It is located on a line that approximately bisects the angle formed by the line passing through the center of the first through hole 26 and the line passing through the center of the fitting hole 25 and the center of the third through hole 28 .

The engagement member 30 includes a support portion 32 rotatably supported by the rotary plate 3, and a plate portion 33 whose base end is fixed to the support portion 32. The guide member 2 has a pin 13 fitted into the support portion 32.
A fitting hole 31 having the same diameter as the fitting hole 25 of No. 1 is provided therethrough. A tip 39 of the plate portion 33 is adapted to engage and disengage from the restraining member 12. Further, two notch grooves are provided in the vertical direction on one side 33a of the plate portion 33, the one provided closer to the support portion 32 is a first notch groove 34, and the one provided closer to the tip is a second notch groove 34. The groove 35 is defined as the groove 35. At the peripheral edges of the first notch groove 34 and the second notch groove 35, there is a first nut 37 (fixed part) and a second nut 37 centered on the center of the notch groove.
A nut (fixed part) 38 is fixed by welding or the like. The length from the center of the first notch groove 34 (the center of the first nut 37) to the center of the fitting hole 31 is the length from the center of the fitting hole 25 of the guide member 21 to the first
The length from the center of the second notch 35 (the center of the second nut 38) to the center of the fitting hole 31 is equal to the length from the center of the through hole 26 and the third through hole 28. It is made equal to the length from the center of the second through hole 27 to the center of the second through hole 27. moreover,
A spring 16 is installed on the bottom surface of the plate portion 33 at the approximately center.
A bracket 36 is fixed to one end of the bracket.

The guide member 21 and the engagement member 30 formed in this way are arranged such that the insertion hole 25 of the guide member 21 and the insertion hole 31 of the engagement member 30 are centered, and the pin 13 is inserted into these insertion holes 25 and 31. for example, the center of the first through hole 26 of the guide member 21 and the first nut 3 of the engaging member 30.
7, insert the bolt (fixing means) 40 into the first through hole 26, and insert the first nut 3.
7, the guide member 21 and the engaging member 3
0 is fixed to form a forced cam 20 (see FIG. 4). Below, the forced cam 2 formed as above
0 is the first forced cam 20a, and the second forced cam 2 is formed by inserting it into the second through hole 27 and screwing the bolt 40 into the second nut 38.
0b, the third forced cam 20c is formed by inserting it into the third through hole 28 and screwing a bolt 40 onto the first nut 37. The first forced cam 20a, the second forced cam 20b, and the third forced cam 20c have different extension angles of the engagement member 30 with respect to the guide member 21, respectively. Specifically, the second forced cam 20
The engaging member 30 of b is bent and extended slightly lower than the engaging member 30 of the first forcing cam 20a, and the engaging member 30 of the third forcing cam 20c is slightly longer than the engaging member 30 of the second forcing cam 20b. is further bent downward and extended. In other words,
The forced cam 20 of this example can change the extension angle of the engaging member 30 with respect to the guide member 21 in three stages.

5 to 7 show the engagement state of the first forced cam 20a, second forced cam 20b, and third forced cam 20c with the restraining member 12 when these forced cams are attached to the loading platform lifting device. Figure 5 is the first
FIG. 6 shows the state of engagement between the forced cam 20a and the restraining member 12, and FIG.
FIG. 7 shows the state of engagement with the third force cam 20.
Fig. 3 shows the state of engagement between c and the restraining member 12.

Comparing the operations when the first forced cam 20a, the second forced cam 20b, and the third forced cam 20c are respectively attached to the loading platform lifting device, the first forced cam 20a, the second forced cam 20b, and the third forced cam 20c are compared. 3. The forcing cam 20c is the engaging member 3 for the guide member 21.
Since the extension angles of 0 are different, the engagement member 3
The timings at which the 0 and the restraining member 12 engage and disengage are all different. In other words. When the tailgate 11 is lowered, the loading platform lifting device to which the first forced cam 20a is attached is operated by the second forced cam 20b and the third forced cam 20c.
The first forced cam 20a and the restraining member 12 are separated from each other earlier than when the first forced cam 20a is attached, and the tailgate 11 is tilted. In addition, when the tailgate 11 is lowered, the loading platform lifting device to which the second forced cam 20b is attached is slower than the one to which the first forced cam 20a is attached, and earlier than the one to which the third forced cam 20c is attached. The forced cam 20b and the restraining member 12 are separated, and the tailgate 11 is tilted. Furthermore, the third
In the loading platform lifting device to which the forced cam 20c is attached, when the tailgate 11 is lowered, the third forced cam 20c and the restraining member 12 separate later than the first forced cam 20a and the second forced cam 20b. Therefore, a cargo handling vehicle with a relatively high cargo platform is equipped with a third force cam 20c that lengthens the lifting stroke, and a cargo handling vehicle with a relatively low cargo platform is equipped with a first forced cam 20a that shortens the lifting stroke. It is only necessary to install the loading platform lifting device with the second forced cam 20b attached to the cargo handling vehicle whose loading platform is located between the above-mentioned heights.

Although this example discloses a forced cam in which the extension angle of the engaging member 30 with respect to the guide member 21 is varied in three stages, the present invention is not limited to this, and the guide member may be used such that the extension angle is varied in small steps. A forced cam formed with the member 21 and the engagement member 30 may also be used. Further, although the guide member 21 and the engaging member 30 are connected and fixed by the bolt 40, the invention is not limited to this, for example,
The engaging member 30 may be provided with holes corresponding to the plurality of through holes provided through the guide member 21, and the two may be connected and fixed by inserting pins into these holes.

(Effect of the invention) As described above, the timing at which the forcing cam and the restraining member engage and disengage can be adjusted by using a single forcing cam whose extension angle of the engaging member relative to the guide member can be varied. Therefore, when the loading platform elevating device is installed on various cargo handling vehicles with loading platforms of different heights, this forced cam can be shared, and the number of parts can be reduced.

[Brief explanation of the drawing]

1 to 7 show a loading platform lifting device for a cargo handling vehicle according to the present invention, FIG. 1 is a side view showing the configuration of the loading platform lifting device, and FIG. FIG. 2b is a side view of the same, and FIG. 3a is a partially cutaway plan view of the engaging member that forms a forced cam with the guide member. 3b is a side view of the same, FIG. 4a is a plan view of the forced cam (first forced cam 20a) formed by the guide member and the engaging member, and FIG. 4b
is a side view of the same, FIG. 5 is a side view showing the engagement state of the first forced cam 20a attached to the loading platform lifting device and the restraining member, and FIG. 6 is the second forced cam 20b attached to the same device. FIG. 7 is a side view showing the engagement state between the third force cam 20c attached to the device and the deterrence member, and FIG. FIG. 2 is a side view showing the loading platform lifting and lowering device. 1...Vehicle frame, 3...Rotary plate, 4...Frame, 5...Lift arm, 7...Tension link, 10...Vertical arm, 11...Tailgate (loading platform), 12...Restraint Parts, 20...
Forced cam, 21... guide member, 30... engagement member.

Claims (1)

[Claims for Utility Model Registration] A base end of a tension link and a rotary plate are pivotally supported on a frame fixed to the rear of the vehicle body frame, a base end of a lift arm is pivotally supported on the rotary plate, and the tension link A parallel link mechanism is formed at the tip of the link and the lift arm to pivotally support the load receiving platform via a vertical arm, a forced cam is pivotally supported on the rotary plate, and a restraining member that can be engaged with and detached from the forced cam is provided on the lift arm. In the cargo platform elevating device provided, the forced cam includes a guide member whose upper surface abuts the guide roller, and an engagement member that engages and disengages from the restraining member, and the guide member has a rotatable member attached to the rotary plate. A fitting hole is provided into which a pin for supporting the rotating plate is fitted, and a plurality of fixing portions are provided at predetermined intervals from the fitting hole, and the engaging member is provided with the rotating plate together with the guide member. A fitting hole is formed into which a pin is fitted for rotatably supporting the guide member, and one or more covers are fixed by a fixing means together with an appropriate one of the plurality of fixing parts of the guide member. A cargo handling vehicle, characterized in that a fixing part is provided, and the extension angle of the engaging member with respect to the guide member can be varied by changing the fixing position of the fixing part and the fixed part by the fixing means. Loading platform lifting device.