JPS6333744Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a cab lowering prevention device that prevents the cab from accidentally lowering in a cab-over-engine type vehicle, and more particularly to a cab tilting device that lifts and tilts the cab with a cylinder device. It relates to something suitable for attachment to.

Generally, in a cab-over type automobile, the cab is lifted and tilted to facilitate maintenance and inspection of the engine portion.

In such a case, the cab is heavy and needs to be tilted beyond the load balance point, so a cylinder device is installed between the cab 1 and the vehicle body (frame) 2, as shown in Figure 1. In some cases, a cab tilt device is used in which a cab tilting device is constructed such that the cab is tilted by the telescopic operation of the cylinder device.

In such a cab tilt device, a cab lowering prevention device is installed to avoid the risk of an unexpected accident caused by the cab lowering over the worker's head in the event of a failure of the cylinder device, etc. There is.

An example of such a cab lowering prevention device is shown in FIG. That is, a stay 6 having a plurality of teeth 7 cut therein is pivotally attached to the upper end of the piston rod 4 of the cylinder device 3, which is pivotally attached to the cab 1, and a claw member 8 is attached to the cylinder 5 of the cylinder device 3, which is attached to the yoke 9. The pawl member 8 meshes with the teeth 7 of the stay 6 to prevent the piston rod 3 from being shortened due to the weight of the cab.

However, such a cab lowering prevention device is configured such that the lowering of the cab is prevented by the pawl member engaging with the teeth. There is a problem with this.

An object of the present invention is to provide a cab lowering prevention device that can immediately prevent the cab from lowering at any position.

In order to achieve this purpose, the present invention is configured so that the brake block is pressed against the surface of the stay pivotally connected to the cab side, so that the cab can be moved by the frictional force between the brake block and the stay at the same time as the cab is lowered. It is designed to support a load of .

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 3 is a front view corresponding to the X arrow view in FIG. 1 showing a cab tilt device equipped with a cab lowering prevention device which is an embodiment of the present invention, FIG. 4 is an enlarged perspective view thereof, and FIG. FIG. 3 is a partial cross-sectional view for explaining the action.

In this embodiment, this cab lowering prevention device 1
0 is attached to the cab tilt device shown in FIG. 1, and includes a stay 11 having one end pivotally attached to the tip of a piston rod 4 attached to the cab side of the cylinder device 3. The stay 11 is formed from a rigid metal material into an elongated, substantially rectangular shape. A channel-shaped yoke 12 is fixed to the cylinder 5 attached to the frame side of the cylinder device 3 so as to straddle it, and the free end of the stay 11 is inserted into the yoke 12 so as to be able to move forward and backward. .

A bracket 13 is provided protruding from the outer surface of the yoke 12, and a pair of link bars 14A, 14B as arms are rotatably pivotally attached to the bracket 13. Brake pads 17 are located at the tips of the link bars 14A and 14B within the yoke 12.
A back plate 16 constituting the brake block 15 is rotatably attached to the brake block 15.
A brake pad 17 is bonded to the surface of the back plate 16 facing the stay 11. The back plate 16 is made of a rigid material such as iron, and the brake pads 17 have a large coefficient of friction.
It is also made of a wear-resistant material.
The length of the link bars 14A, 14B is set to be longer than the distance of the bracket 13 to the stay 11, and
4B is attached to the bracket 13 so that when the brake block 15 is in contact with the stay 11, the end on the stay 11 side is inclined upward toward the piston rod 4 side. Further, the link bars 14A and 14B hold the brake pads 17 of the brake blocks 15 in constant contact with the surface of the stay 11.

One link bar 14A has an extended end opposite to the pivoted portion of the stay 11, and a rotating operation means such as an operating wire 18 is locked to the extended end. A reaction force brake pad 19 is bonded to the inner surface of the yoke 12 on the side opposite to the brake block 15 so as to sandwich the stay 11 and substantially face the brake pad 17.

Next, the effect will be explained.

If a failure occurs in the cylinder device 3 while the cab is tilted and the piston rod 4 attempts to shorten due to the load of the cab,
A force G corresponding to the load of the cab acts on the stay 11. At this time, since the brake pads 17 of the brake block 15 are constantly in contact with the stay 11 using the weight of the back plate 16, the brake block 15 is moved by the force W that depends on the force G and the friction coefficient of the brake pads 17. It will be pushed toward the base end (downward) of the cylinder 5.

When this force W acts, link bars 14A, 1
4B holds the brake block 15 at an upwardly inclined angle Θ, the brake pad 17 is pressed against the stay 11 by the brake block 15 with a direct pressure R expressed by the following equation (1). This direct pressure R causes a frictional force F expressed by the following equation (2) to act between the brake block 15 and the stay 11. This frictional force F immediately prevents the stay 11 from descending, and the cab is brought to a sudden stop regardless of its position.

R=W/tanΘ...(1) F=μR...(2) Since the brake pad 19 for reaction force is bonded to the yoke 12, the stay 11 also receives a frictional force due to the reaction force corresponding to the direct pressure R. act.

If you want to release the restraint of the stay 11 by the brake block 15 and lower the cab, pull the operating wire 18 downward and move the link bars 14A, 1.
The brake block 15 may be separated from the stay 11 by rotating the brake block 4B upward. That is, when the brake pads 17 of the brake block 15 come out of contact, the force W pushing the brake block 15 downward is eliminated, so the direct pressure R
disappears, and the frictional force F no longer acts.

After the restraint of the stay 11 by the brake block 15 is released, the cab is lowered as the piston rod 4 of the cylinder device 3 is shortened. At this time, by appropriately repeating the separation and contact of the brake block 15, the descending speed of the cab can be made gentle.

When the cylinder device 3 lifts the cab, the link bars 14A and 14B are tilted upward, so the brake block 1
5 will be idly sliding, and no direct pressure R will be generated, so no frictional force F will be generated. Therefore, the cab lowering prevention device 10 is prevented from adversely affecting the cab tilting operation by the cylinder device 3.

According to this embodiment, the brake block 15 and stay 11 are
Since the stay 11 is automatically restrained by the frictional force generated between the stay 11 and the cab tilt device, it is possible to automatically stop the cab in an emergency at the same time as a failure occurs in the cylinder device 3 in the cab tilt device and the cab begins to descend. can. Therefore, the cylinder device 3
It is possible to prevent unexpected personal accidents caused by the lowering of the cab in the event of a failure.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and may be modified without departing from the gist thereof.
It goes without saying that various changes are possible.

For example, as a means for keeping the brake pads of the brake block in constant contact with the stay, a spring may be used that constantly biases the brake block in the direction of the stay.

The structure of the brake block is not limited to being composed of a back plate and a brake pad, but may be integrally formed of a material having an appropriate coefficient of friction, wear resistance, etc.

The arm for pressing the brake block against the stay is not limited to a link mechanism. However, if a link mechanism is used, the brake block can be pressed against the stay evenly throughout.

As explained above, according to the present invention, the lowering of the cab can be immediately stopped regardless of the position of the cab.

[Brief explanation of drawings]

FIG. 1 is a schematic side view showing a cab tilt device to which the present invention can be applied, and FIG. 2 is a first side view showing a conventional example.
FIG. 3 is a front view corresponding to the X-arrow view of FIG. 1 showing an embodiment of the present invention; FIG. 4 is an enlarged perspective view thereof; FIG. is a partial cross-sectional view for explaining the action. 1... Cab, 2... Frame, 3... Cylinder device, 4... Piston rod, 5... Cylinder, 10... Cab descent prevention device, 11... Stay, 12... Yoke, 13... Bracket, 14
A, 14B...Link bar (arm), 15...
Brake block, 16...Back plate, 1
7, 19...brake pad, 18...operation wire.

Claims (1)

[Claims for Utility Model Registration] (1) A cab lowering prevention device that prevents a tilted cab from accidentally descending by a cylinder device interposed between a cab and a frame, which includes: A stay is rotatably connected to the end of the piston rod that is pivotally connected to the cab, and the middle part of the stay is inserted into a yoke fixed to the cylinder of the cylinder device so as to be freely retractable, and an arm is attached to this yoke. A cab lowering prevention device characterized in that a brake block is attached to a free end of the arm so as to be rotatable, and a brake block is attached to the free end of the arm so as to be pressed against the stay. (2) Utility model registration claim 1, characterized in that the arm is disposed on the yoke so that the free end slopes upward toward the cab side when the brake block is in contact with the stay. Cab lowering prevention device as described in section.