JPS6323228Y2 - - Google Patents

Description

This invention relates to a gate plate tilt control device for a tailgate lifter. More specifically, it relates to an improvement to a tailgate lifter (hereinafter simply referred to as a lifter) that raises and lowers the gate plate via a parallelogram link mechanism attached to the rear of the vehicle's loading platform to load and unload luggage.

The purpose of this invention is to ensure that when a load is placed on the gate plate and lifted or lowered between the ground position and the elevated position, the gate plate is always maintained in a horizontal state during lifting and lowering, and when the gate plate is placed close to the ground, the gate plate An object of the present invention is to provide a gate plate tilting control device that allows the gate plate to be tilted smoothly to safely load and unload cargo.

FIG. 1 shows a lifter equipped with the gate plate tilting control device of the present invention. Reference numeral 1 denotes a frame attached to the lower part of the rear part of the vehicle, and both ends of a rotating shaft 2 are rotatably supported by this frame. A rotating arm 3 is fixed approximately at the center of this rotating shaft, and a rod end of a hydraulic cylinder 4 is pivotally supported at the tip of this rotating arm 3.

A pair of rotating side plates 5 are provided at both ends of the rotating shaft 2, respectively.
is fixed. Further, one end of a tension arm 6 is rotatably attached to the frame 1 by a pin 7. Further, one end of a lift arm 8 is pivotally supported on the rotating side plate 5 by a pin 9. A vertical arm 11 is pivotally supported at the tips of the tension arm 6 and the lift arm 8 by pins 13 and 14.
The tension arm 6, lift arm 8, rotating side plate 5, and vertical arm 11 constitute a parallelogram link mechanism.

FIG. 2 shows a conventional parallelogram linkage. A contact member 10 is fixed to the inner surface of the rotating side plate 5, and when the rotating side plate 5 rotates counterclockwise, in other words, when the gate plate 12 rises, it comes into contact with the rear surface of the lift arm 8, and lifts. This is for rotating the arm 8 together with the rotating side plate 5.

An ear piece 15 that projects upward from the lift arm 8 is provided at a position away from the pin 9 of the lift arm 8. A pawl 16 is pivotally attached to this ear piece 15, and when the rear surface of the lift arm 8 and the abutment member 10 come into contact with each other and engage, the pawl 16 is attached to the rotation axis between the left and right rotating side plates 5, 5. It is arranged to engage a ratchet 17 arranged above. The pawl 16 is provided with a handle 18 by which the pawl can be manually lifted from the ratchet 17. Further, the pawl 16 is always urged by a spring 19 so as to engage the rear surface of the ratchet 17.

Next, the action of the pawl 16 and the ratchet 17 will be described. When the rotary shaft 2 is rotated counterclockwise to raise the gate plate 12, the lift arm 8 first
When the rear surface of the pawl 16 abuts against the abutting member 10 fixed to the inside surface of the rotating side plate 5, the pawl 16 engages with the rear portion of the ratchet 17 by the spring 19, and the gate plate 12 is securely held in a horizontal position and rises to the raised position. However, if the spring 19 breaks or
If the claw 16 malfunctions due to lack of oil, rust, freezing, etc., the claw 16 does not engage with the ratchet 17, which causes the outer end of the gate plate 12 to suddenly tilt downward, causing luggage to fall and resulting in personal injury. The present invention has been improved to prevent such dangerous and unreliable operation, and the following embodiment will be described as the third embodiment.
The following description will be given with reference to the following figures.

Figure 3 is an explanatory diagram of the operation of the lifter T. A is when the gate plate is in the raised position, B is when the lower end of the link mechanism is in contact with the ground, and C is when the gate plate is between the above A and B positions. State D indicates a state in which the tip of the gate plate is in a tilted position in contact with the ground. Fourth
The figure shows the state of the gate plate tilting control device corresponding to A in Fig. 3, Fig. 5 shows the gate plate tilting control device corresponding to B in Fig. 3, and Fig. 6 shows the state of the gate plate corresponding to C in Fig. 3. It is an explanatory view of a tilting control device.

Reference numeral 20 denotes a forced cam pivotally supported between a pair of rotating side plates 5, 5 by a pin 21. A restraining member 22 that can be engaged with and detached from the tip of the forced cam 20 is fixed to the lift arm 8 near the pin 9. In addition, forced cam 20
Although in FIG. 1 it is arranged in the middle of the rotating side plate 5, the object of the present invention can also be achieved by disposing it outside the outer rotating side plate 5 or further inside the inner rotating side plate 5. Above the rotating shaft 2, one end of a tension arm 6 is rotatably attached to the frame 1 by a pin 7, and the upper surface of the force cam 20 is in contact with the outer peripheral surface of the extension of the pin 7.

The forced cam 20 has a shape as shown in FIG. A circular arc surface 20a with a radius R centered on the rotation axis 2
Similarly, a circular arc surface 20b having a radius R'(R'>R) is continuous with an arcuate stepped portion 20c. The tail end of the forced cam is a straight portion 20d, and the end of the straight portion 20d is adapted to engage with the recess 22a of the restraining member 22. Note that the radius R of the circular arc surface 20a is set as R=L-d/2.

L: Center-to-center distance between rotating shaft 2 and pin 7 d: Diameter of pin 7 When gate plate 12 descends, arcuate surface 20a
From the ascending position A to just before the ground position B, and for the arcuate surface 20b, from just before the gate plate 12 reaches the ground position,
During the movement to the tilting position N, the pin 7 is slid and guided.

When the rotating shaft 2 rotates clockwise (the gate plate 12 descends), the forced cam 20, which was sliding on the arcuate surface 20a, is rotated further, and the stepped portion 20c of the forced cam 20 becomes a pin. It borders on 7. Then, as the rotating shaft 2 rotates, the forced cam 20
is rotated counterclockwise around the pin 21 (solid line→two-dot chain line in FIG. 8). When the rotating shaft 2 further rotates clockwise, the outer periphery of the pin 7 slides on the arcuate surface 20b. At this time, the tip of the forced cam 20 is lifted counterclockwise. That is, it separates from the restraining member 22 (FIG. 5).

Referring to FIG. 7, the stepped portion 20c of the forced cam 20
The relationship between and pin 7 is shown. When the rotating shaft 2 rotates clockwise, the stepped portion 20c of the forced cam 20 that is in contact with the outer periphery of the pin 7 rotates counterclockwise around the pin 21 due to the rotation of the rotating shaft 2, and rotates as shown by the chain line. , the engagement with the restraining member 22 is released.

Note that the restraining member 22 is fixed to the lift arm 8 and has a groove 22 for engaging with the tip of the forced cam 20.
a, and this groove is machined at a right angle so that the tip of the forced cam 20 engages with it.

In the embodiment of the present invention, the outer periphery of the pin 7 is in contact with the arcuate surfaces 20a, 20b of the forced cam. Another contacting engagement member may be provided.

As described above, according to the present invention, the rotating side plate is pivotally mounted with a pin, and a circular arc surface having a radius R centered on the rotation axis and a circular arc surface having a radius R′>R are continuous at an arc-shaped stepped portion,
A forced cam connected to an arcuate surface with a radius R and whose tail end is a straight part, and the end of the straight part engages with a recess of a restraining member fixed to the lift arm; It consists of a pin fixed to the frame that is in contact with two circular arc surfaces with different radii, and when the rotating side plate rotates, the force cam and the restraining member engage to hold the gate plate horizontally or when tilting. I tried to remove that engagement.

And although there is no biasing spring etc. in the forced cam,
By constantly contacting the pin on the frame side, the engagement with the restraining member can be automatically and smoothly disengaged, so there is no chance of it coming off during operation, and extremely safe gate plate tilting is possible. This makes it possible to

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a lifter using the present invention.
FIG. 2 is a side view of a known lifter. FIG. 3 is a diagram showing the vertical operation state of the gate plate. 4 to 6 are explanatory views of the operation of the gate plate tilting control device. FIG. 7 is an explanatory diagram of the operation of the forced cam. FIG. 8 is a functional explanatory diagram of the arcuate stepped portion of the forced cam. In the figure; 1...frame, 2...rotation axis,
3... Rotating arm, 4... Hydraulic cylinder, 5...
Rotating side plate, 6...Tension arm, 7...Pin, 8...Lift arm, 9...Pin, 10...
Contact member, 11... Vertical arm, 12...
Gate plate, 13, 14... pin, 15... ear piece,
16...Claw, 17...Ratchet, 18...Handle, 19...Spring, 20...Forced cam, 20
a, 20b...(forced cam) arc surface, 20c...
...Arc-shaped step part, 20d...Straight line part, 21...Pin,
22...Suppression member.

Claims (1)

[Claims for Utility Model Registration] A rotating shaft 2 rotatably supported by a frame 1 fixed to the rear of the vehicle, a rotating arm 3 fixed to the rotating shaft 2, and a rotary arm 3 pivotally supported at the tip of the rotating arm 3, A hydraulic cylinder 4 whose other end is pivotally supported within the frame 1; a rotating side plate 5 which is located on both sides of the frame 1 and fixed to both ends of the rotating shaft 2; and one end which is pivoted to both sides of the frame 1. A gate plate 12 is pivotally connected to the other end of the tension arm 6 together with the upper part of the vertical arm 11 with a pin 13, and one end is attached to both sides of the rotating side plate 5 with pins 9, respectively. It comprises a lift arm 8 which is pivotally connected and whose other end is pivotally connected to the lower part of the vertical arm 11 by a pin 14, and a contact member 10 which is connected to and disengaged from the lift arm 8 and is fixed to the rotating side plate 5, In the tailgate lifter T, which enables the tilting operation and raising/lowering operation of the gate plate 12 by driving the hydraulic cylinder 4, the tailgate lifter T is pivotally connected to the rotating side plate 5 with a pin 21, and has a radius R around the rotating shaft 2. The circular arc surface 20a and the circular arc surface 20b having the same radius R' are continuous at the arc-shaped step 20c, and the radius R
The tail end is connected to the arcuate surface 20a of the lift arm 8 and forms a straight part 20d, and the end of the straight part 20d is adapted to engage with the recess 22a of the restraining member 22 fixed to the lift arm 8. A cam 20 and two arcuate surfaces 20a, 2 with different radii of curvature of the forced cam 20.
A pin 7 fixed to the frame 1 in contact with 0b
When the rotating side plate 5 rotates, the forced cam 20 and the restraining member 22 engage with each other to hold the gate plate 12 horizontally, or release the engagement when tilting, and Two arcuate surfaces 20a, 2
The relationship between the radius R and R' of 0b is R'> R, R = L - d/2 L: distance between the centers of the rotating shaft 2 and pin 7, d: diameter of pin 7. Tailgate lifter gate plate tilt control device.