JPS6147746B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mechanical stopper for tilting the cab of a cab-over-engine type vehicle, and in particular, in a mechanical stopper for tilting the cab of a cab-over-engine type vehicle, the mechanical stopper tilts the cab using a hydraulic cylinder. To provide a mechanical stopper for cab tilt, which allows the mechanical stopper to be smoothly released even if the piston rod of a hydraulic cylinder is slightly lowered when oil leaks.

Conventionally, in systems where the cab tilt was performed using a hydraulic cylinder, the piston was always oil-locked at the stop position, so the cab tilt could be controlled to any desired position. A mechanical stopper with a section is used, and in the unlikely event of a problem with natural descent, the nearest step will hit the stopper and hold the cab in a tilted state. However, if the final stage part of the mechanical stopper contacts and engages with a locking part formed on the cylinder to open the cab tilt stop switch and hold the cab in the full tilt state for a long time, the hydraulic cylinder In this case, the piston rod is lowered, and the load of the cab is applied from the final stage of the mechanical stopper to the locking part of the cylinder, and the mechanical stopper is connected to the hydraulic cylinder. It gets stuck in the locking part,
There have been cases where a problem has occurred in which the mechanical stopper cannot be released smoothly.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the prior art.The purpose of the present invention is to provide a system in which a cab is tilted by a hydraulic cylinder, and when the cab is fully tilted, a mechanical stopper is activated. By making the final stage stop at a position slightly above and away from the locking part of the hydraulic cylinder, the mechanical stopper can be smoothly released even if the cab is left at full tilt for a long time. be.

In short, the present invention tilts a cab using a hydraulic cylinder, in which the base end of the hydraulic cylinder is pivotally connected to a frame on the chassis side,
The upper end of the piston rod is pivotally connected to a bracket fixed to the cab side, and a mechanical stopper having a plurality of steps, a final step, a recess continuous to the final step, and a protrusion projecting from the recess is attached to the bracket. The mechanical stopper is pivotably mounted and configured to operate a cab tilt stop switch with a part of the mechanical stopper, and is biased to press the mechanical stopper against the hydraulic cylinder by an elastic member. A locking portion is provided with which the step portion of the mechanical stopper engages to hold the cab in a tilted state, and a release member of the mechanical stopper is pivotally connected to a part of the hydraulic cylinder, and the release member is pivotally connected to a part of the hydraulic cylinder. The member rotates in one direction to rotate the mechanical stopper away from the hydraulic cylinder, and has a convex portion and a concave portion that restricts movement of the protrusion at the final stage of the mechanical stopper during full tilt. The mechanical stopper opens and stops the cab tilt stop switch at a position where the final stage section is slightly above the locking section of the hydraulic cylinder when the cab is fully tilted, and at this time, the mechanical stopper opens the cab tilt stop switch and stops the final stage section. The final step is positioned slightly above the locking portion and engages with the locking portion when the protrusion of the locking portion falls into the recess of the release member.

The present invention will be explained below based on embodiments shown in the drawings. In FIG. 1, a lower front end la of a cab 1 is supported by a pair of left and right coil springs 2 (only the left side is shown). The lower end 2a of the coil spring 2 is supported via a spring receiving member 3 by a pair of left and right link levers 4 (only the left side is shown) which also serve as spring seats 4a. The link lever 4 is pivotally connected to a tilt hinge 7 at the upper end 6a of a cab mount bracket 6 fixed to the frame 5 on the chassis side, and extends rearward. It is rotatably connected to the connecting pin 8a. The upper end 2b of the coil spring 2 is supported by a spring receiving portion 9 on the cab 1 side via a rubber bush 10. Further, a pair of left and right shock absorbers 11 (only the left side is shown) is attached between the link lever 4 and the bracket 8.

A hydraulic cylinder 12 for cab tilting has a base end 12a pivotally connected to the frame 5, and an upper end of a piston rod 12b pivotally connected to the bracket 8. Further, a flange-shaped locking portion 12c is formed at the upper end of the hydraulic cylinder 12. Bracket 8
The upper end of a mechanical stopper 13 for holding the cab 1 in a tilted state is pivotally attached to the upper end of the mechanical stopper 13.
In the illustrated embodiment, it can be tilted in seven stages. A relatively long recess 13e is formed below the final step 13b of the step 13a of the mechanical stopper 13, and a protrusion 13f protruding toward the hydraulic cylinder 12 is formed at the lower end.

Further, a release member 14 is pivotally connected to the hydraulic cylinder 12 from a locking portion 12c of the mechanical stopper 13, and the release member 14 has two parts that engage with each stepped portion 13a of the mechanical stopper 13. Convex portions 14a and 14b are formed sandwiching concave portion 14c. The lower convex portion 14b cooperates with the protrusion 13f of the mechanical stopper 13 to provide a time delay to the operation of the mechanical stopper 13.

A cab tilt stop switch 15 is attached to the bracket 8, and an arm member 16 is fixed to the mechanical stopper 13, the tip 16a of which contacts the actuator 15a of the switch to open the switch. is bracket 8
from the mechanical stopper 13 to the hydraulic cylinder 12
A spring 17 is tensioned to constantly press and bias.

A release wire 18 is connected to the release member 14, and the release member is always biased counterclockwise in the figure by a compression spring 19 and held in a fixed position.

The present invention is configured as described above, and its operation will be explained below. When the hydraulic cylinder 12 operates, the piston rod 12b projects upward and pushes the bracket 8 upward, so that the cab 1 is integrated with the link lever 4, coil spring 2, shock absorber 11, and bracket 8, and rotates around the tilt hinge 7. When the link lever 4 is rotated and tilted counterclockwise in the figure, and the link lever 4 is rotated by a certain amount, the protrusion 4a at the tip 4c moves to the second position.
As shown in the figure, the link lever 4 comes into contact with the flat surface 6d of the protrusion 6c of the cab mount bracket 6, the rotation of the link lever 4 is stopped, the tilt center moves to the connecting pin 8a, and the bracket 8 is linked around the connecting pin. The coil spring 2 and the shock absorber 11 are compressed and contracted by rotating counterclockwise in the figure relative to the lever 4, resulting in a full tilt state as shown in FIG.

At this time, the mechanical stopper 13 is displaced relative to the hydraulic cylinder 12, and its final stage portion 13b
At the time when the end projection 13f passes through the locking portion 12c of the hydraulic cylinder 12, the protrusion 13f of the release member 14
Since it is in contact with 4b, mechanical stopper 1
3 does not turn completely and the tip 16 of the arm member 16
a has not yet pressed the actuator 15a of the tilt stop switch 15, so the electric motor (not shown) for driving the hydraulic pump continues to rotate.
The piston rod 12b further projects upward. As a result, the final stage 1 of the mechanical stopper 13
3b rises to a position slightly upwardly away from the locking portion 12c, as shown in FIG. Then, the protrusion 13f of the mechanical stopper 13 releases the release member 1.
4 and falls into the recess 14c, the mechanical stopper 13 is rotated clockwise in the figure by the spring 17, and the tip 16 of the arm member 16 is rotated clockwise in the figure by the spring 17.
a presses the actuator 15a of the switch 15. As a result, the electric motor stops, the piston 12b of the hydraulic cylinder 12 stops, and the final stage part 13b of the mechanical stopper 13 stops at a position slightly above the locking part 12c, with a gap C between them. (C is, for example, 4 to 5 mm).

For this reason, if cab 1 is left at full tilt for a long time,
For example, even if the piston rod 12b is left for a day or night for repairs, the gap C will not become zero even if the piston rod 12b goes down a little due to oil leakage.
By pulling the wire 18, the release member 14 rotates clockwise in the figure against the spring 19, and the final step 13b of the mechanical stopper 13 is easily removed from the locking part 12c. Therefore, the cab 1 can be returned to the non-tilted state without any trouble.

Since the present invention is constructed and operates as described above, when the cab is tilted by a hydraulic cylinder, when the cab is fully tilted, the final stage portion of the mechanical stopper is connected to the locking portion of the hydraulic cylinder. Since it can be stopped at a slightly higher and further away position, even if the cab is left at full tilt for a long period of time, the mechanical stopper can be released smoothly afterwards, making the cab tilting operation smoother. be able to.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention, and FIG. 1 is a side view showing the cab suspension and tilt mechanism;
FIG. 2 is a side view similar to FIG. 1 in a fully tilted state of the cab. 1 is a cab, 5 is a frame on the chassis side, 8 is a bracket, 12 is a hydraulic cylinder, 12a is a base end, 12b is a piston rod, 12c is a locking part,
13 is a mechanical stopper, 13a is a plurality of steps, 13b is a final step, 13e is a recess, 13f is a projection, 14 is a release member, 14a and 14b are projections,
14c is a recess, 15 is a tilt stop switch, 1
6 is an arm member forming a part of the mechanical stopper; 1
7 is a spring which is an example of an elastic member.

Claims (1)

[Claims] 1. In a system in which the cab is tilted by a hydraulic cylinder, the base end of the hydraulic cylinder is pivotally connected to a frame on the chassis side, the upper end of the piston rod is pivotally connected to a bracket fixed to the cab side, and a plurality of stages are mounted. A mechanical stopper having a part, a final stage part, a recessed part continuous with the final stage part, and a protrusion protruding from the recessed part is pivotally attached to the bracket, and a part of the mechanical stopper operates a cab tilt stop switch. The mechanical stopper is pressed against the hydraulic cylinder by an elastic member, and the stepped portion of the mechanical stopper engages with a part of the hydraulic cylinder to hold the cab in a tilted state. A locking portion is provided, and a release member for the mechanical stopper is pivotally connected to a part of the hydraulic cylinder, and the release member rotates in one direction to release the mechanical stopper from the hydraulic cylinder. The mechanical stopper has a convex portion and a recessed portion for rotating in a direction away from the cab and restricting the movement of the protrusion of the final stage portion of the mechanical stopper when the cab is fully tilted, and the mechanical stopper has a convex portion and a concave portion that restrict the movement of the protrusion of the final stage portion of the mechanical stopper when the cab is fully tilted. The cab tilt stop switch is opened and stopped at a position slightly above the locking portion of the cylinder, and at this time, the protrusion of the final step falls into the recess of the release member, causing the final step to be released. A mechanical stopper for cab tilt, characterized in that it is configured to be positioned slightly above and engaged with a locking part.