JPS6148459B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing cab wobbling when the cab is tilted in a cab over engine type vehicle, and particularly in a cab of a suspension system using a coil spring, the coil spring is the cause of the cab wobbling when the cab is tilted. The present invention relates to a device that prevents the wobbling of the cab that occurs when the cab tilts by changing the tilt center of the cab during the tilt.

Conventionally, in suspension-type cabs in which the lower front end of the cab is supported by a pair of left and right coil springs, the spring constant of the suspension coil springs is very small, so the coil springs may cause damage during tilt or at full tilt. The drawback was that the cab would wobble and be unstable.

The present invention has been made to eliminate the drawbacks of the prior art described above, and its purpose is to provide a suspension type cab in which the lower front end of the cab is supported by a pair of left and right coil springs.
To prevent the cab from wobbling caused by a coil spring when the cab is tilted, and to maintain a sufficiently stable tilted state of the cab especially when the cab is fully tilted. Another object is to shorten the stroke of the cylinder required during full tilt by moving the tilt center closer to the hydraulic cylinder during the tilt.

In short, the present invention provides a suspension-type cab in which the lower front end of the cab is supported by a pair of left and right coil springs, in which a pair of left and right link levers that also serve as spring seats for the coil springs are attached to a cab mount fixed to a chassis frame. The coil spring is pivotally connected to the bracket and extends rearward, and the coil spring is installed between the front end of the link lever and the cab, and one end of the link lever extending rearward is attached to the left and right ends fixed to the cab. A hydraulic cylinder is rotatably connected to a pair of brackets, and one end of a piston rod of a hydraulic cylinder whose base end is pivotally connected to the chassis frame is rotatably connected to the bracket, and the front end of the link lever is connected to the hydraulic cylinder. The link lever is configured such that the rotation of the link lever is stopped by coming into contact with one end of the cab mount bracket during the tilting of the link lever,
After the contact, the cab is rotated and tilted around a connection point between the link lever and the bracket fixed to the cab side, and at this time, the coil spring is compressed and brought into close contact. It is characterized by this.

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 a chassis frame 5 on the chassis side, and extends rearward, one end 4b of which is fixed to the cab 1. It is rotatably connected to the bracket 8 around a connecting pin 8a serving as a connecting point. The upper end 2b of the coil spring 2 is the spring receiving part 9 on the cab 1 side.
is supported via a rubber bush 10.

Front upper end 6b of cab mount bracket 6
A protrusion 6c is formed toward the front, and the upper surface thereof is a stepped flat surface 6d. On the other hand, the front end 4c of the link lever 4 is formed with a protrusion 4d facing forward, and when the cab 1 is tilted, the protrusion 4d
contacts the flat surface 6d of the protrusion 6c of the cab mount bracket 6, and it becomes impossible to tilt the cab 1 about the tilt hinge 7 any further, and after this contact, the cab 1 is fixed to the link lever 4 and the cab 1 side. The cab 1 is tilted about a connecting pin 8a, which is a connecting point with the bracket 8, and the coil spring 2 is compressed at this time to prevent the cab 1 from wobbling.

In FIG. 1, 11 is a shock absorber, and 12 is a hydraulic cylinder for tilting, the base end of which is pivotally connected to the chassis frame 5. Also 1
3 is a mechanical stopper, 14 is a release member for the mechanical stopper 13, 15 is a switch that closes the drive circuit of an electric motor (not shown) for driving the hydraulic pump when the cab 1 is fully tilted, and 16 is a release member for the mechanical stopper 13. The arm member 17 that is fixed and opens the switch 15 at full tilt is a spring that constantly presses the mechanical stopper 13 against the hydraulic cylinder 12 via the arm member 17.

The present invention is configured as described above, and its operation will be explained below. When the hydraulic cylinder 12 operates and its piston rod 12a protrudes upward, the bracket 8 is pushed up and the cab 1
Bracket 8, link lever 4, coil spring 2
Together with the shock absorber 11, the coil spring 2 is rotated and tilted counterclockwise in the figure around the tilt hinge 7, and in this case, the coil spring 2 is not compressed.

When the tilt angle reaches a certain value, the projection 4d of the link lever 4 comes into contact with the projection 6d of the cab mount bracket 6, as shown in FIG.
As a result, it is no longer possible to rotate the link lever 4 around the tilt hinge 7, and the cab 1
The tilt center moves to the connecting pin 8a, which is the connecting point, and the bracket 8 and cab 1 continue to tilt around the connecting pin, so the coil spring 2 and the shock absorber 11 are compressed and brought into close contact with each other. It no longer functions as a spring, and the cab 1 is reliably maintained at full tilt without wobbling. Furthermore, after the tilt center moves to the connecting pin 8a, the distance between the cylinder 12 and the tilt center becomes shorter, and the rotation angle of the cab 1 increases for the same amount of protrusion of the piston rod 12a. In comparison, the stroke of the cylinder 12 required to fully tilt the cab 1 is short. On the other hand, at this time mechanical stopper 1
The final stage 13a of No. 3 is the locking portion 1 of the hydraulic cylinder 12.
2b, and the tip 16a of the arm member 16
presses the actuator 15a of the switch 15 to open the switch, the operation of the hydraulic cylinder 12 is stopped, the piston rod 12a is oil-locked, and the cab 1 is fixed in the full tilt state.

Since the present invention is configured and operates as described above, in a suspension type cab in which the lower front end of the cab is supported by a pair of left and right coil springs, the problem occurs when the cab is tilted due to the coil springs. The effect of preventing the cab from wobbling is obtained, and especially the effect of maintaining a sufficiently stable tilted state of the cab at full tilt is obtained. Furthermore, since the tilt center is moved to a position closer to the hydraulic cylinder during the tilt of the cab, the effect of shortening the stroke of the cylinder required at full tilt can be obtained.

[Brief explanation of the drawing]

The drawings relate to an embodiment of the present invention, in which FIG. 1 is a side view showing the suspension and tilt mechanism when the cab is in a non-tilted state, and FIG. 2 is a side view similar to FIG. 1 when the cab is in a fully tilted state. 1 is the cab, 1a is the lower front end of the cab, 2 is the coil spring, 4 is the link lever, 4a is the spring catch,
4b is one end of the link lever, 4c is the front end of the link lever, 5 is the chassis frame, 6 is the cab mount bracket, 6c is one end of the cab mount bracket, 8 is the bracket, 8a is the connection pin that is the connection point, 12 is the connection pin. The hydraulic cylinder 12a is a piston rod.

Claims (1)

[Claims] 1. In a suspension type cab in which the lower front end of the cab is supported by a pair of left and right coil springs,
A pair of left and right link levers, which also serve as spring seats for the coil springs, are pivoted to cab mount brackets fixed to the chassis frame and extend rearward, and the coil springs are connected to the front ends of the link levers and the cab. One end of the link lever extending rearward is rotatably connected to a pair of left and right brackets fixed to the cab, and the base end is pivotally connected to the chassis frame. One end of the piston rod of the cylinder is rotatably connected to the bracket, and the front end of the link lever comes into contact with one end of the cab mount bracket during the tilting by the hydraulic cylinder, and the rotation of the link lever is stopped. After the cab is connected, the cab is rotated and tilted around the connection point between the link lever and the bracket fixed to the cab side, and at this time, the coil spring is compressed and brought into close contact. A cab wobbling prevention device when tilting is characterized by being configured as follows.