JP2564287Y2 - Cab suspension system - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension device for supporting a cab of a vehicle such as a cab-over type truck. More specifically, the present invention relates to a suspension device using an air spring.

[0002]

2. Description of the Related Art As a suspension device of this type, the applicant of the present invention has proposed that a lower surface of a front end of a cab is mounted on a chassis frame via a first air spring, and a lower surface of a rear end of the cab is mounted on a chassis frame via a second air spring. And the lower end of the front end of the cab is pivotally supported on the chassis frame via a torsion tube and a lower pin extending in the vehicle width direction so that the cab can be tilted up, and the first and second air springs are cut valve and leveling, respectively. We have applied for a tilt cab air suspension device connected to an air tank via a valve (Japanese Utility Model Application Laid-Open No. 63-158481). In this device, a base end of a switching lever is pivotally connected to a leveling valve fixed to a chassis frame, and a lower end of an arm suspended from a cab floor panel is pivotally connected to a distal end of the switching lever. The first according to the variation of the distance
Alternatively, the compressed air in the second air spring is supplied and discharged. In this device, when the cab is tilted up, the cut valve is closed, and the supply and discharge of the compressed air in the first and second air springs is always stopped regardless of the rotation angle of the switching lever. When the cab is tilted down, the cut valve is opened. When opened, the first and second air springs are configured to be immediately in a state before the tilt-up.

[0003] However, in the above apparatus, a cut valve must be used, and there is a problem that the number of parts and the number of piping steps are increased.

In order to solve these problems, as shown in FIG. 7, a lower end of the front end of the cab 3 extends in the vehicle width direction, and a torsion tube 9 is provided on the same axis M as the tube 9. Compressed air supplied to and discharged from the first air spring is stored in the torsion tube through a lower pin that is not tilted, and is pivotally supported by the chassis frame 4 via a lower pin. A cab suspension device to which the valve 6 is attached is conceivable. This device has an arm 6c in which a base end of a switching lever 6a is rotatably mounted on a front leveling valve 6, and one end of a link 6b pivotally attached to one end of the switching lever 6a and the other end of which is fixed to the cab 3.
Is pivoted to. The valve 6 is a four-port two-position switching valve. When the switching lever 6a is horizontal with the longitudinal direction of the valve 6 oriented vertically, the supply and discharge of compressed air to the first air spring is stopped. When the switching lever 6a rotates upward and the tip of the lever is positioned above the horizontal direction, the compressed air in the first air spring is discharged, and conversely, the switching lever 6a rotates downward and the tip of the lever moves in the horizontal direction. When located below, compressed air is supplied into the first air spring.

[0005]

The operation of the improved suspension device when the cab is tilted up will be described more specifically with reference to FIGS. 8 and 9. FIG. When the cab 3 starts to tilt up, the center of gravity G of the cab 3 is located behind the vertical plane including the axis M, so that the cab 3 rises while maintaining a substantially horizontal state for a while, and the switching lever 6
a gradually rotates upward through the arm 6c and the link 6b to position the tip of the lever 6a above a direction perpendicular to the longitudinal direction of the valve 6 (FIG. 8), and discharges compressed air in the first air spring. I do. Thereafter, when the cab 3 starts to rotate around the lower pin and the center of gravity G of the cab 3 approaches a vertical plane including the axis M, the valve 6 is also connected to the torsion tube 9.
As a result, the tip of the switching lever 6a is still above the direction perpendicular to the longitudinal direction of the valve 6 (FIG. 9), and the compressed air is kept discharged into the first air spring. When the center of gravity G of the cab 3 moves forward beyond the vertical plane including the axis M in this state, the cab 3 is tilted around the torsion tube 9 and the lower pin because the compressed air in the first air spring is in a discharged state. There was a problem of sudden rotation in the up direction.

An object of the present invention is not to use a cut valve.
Therefore, the number of parts can be reduced and the pipe steps, further Cat Ba
Pressure from the first air spring at the time of tilting up without using lube
An object of the present invention is to provide a cab suspension device that can smoothly tilt up while keeping the cab in a stable state by restricting the discharge of compressed air .

[0007]

The configuration of the present invention for achieving the above object will be described with reference to FIGS. 1 and 3 corresponding to the embodiment. The present invention relates to a chassis frame 1 of a vehicle 10.
4, the lower surface of the front end is placed via the first air spring 11, and the lower surface of the rear end is mounted on the second air spring 12 and the floating arch 16.
And a cab 13 pivotally supported by a chassis frame 14 via a lower pin 17 provided with a lower front end extending in the vehicle width direction, between the chassis frame 14 and the cab 13. A fluid pressure cylinder 31 for rotating the cab 13 about the lower pin 17, a front leveling valve 36 attached to the chassis frame 14 for supplying and discharging compressed air from the air tank to the first air spring 11, and a front leveling valve 36 . A first air spring when the proximal end is rotatably mounted and the distal end faces upward;
11 is supplied with the compressed air and the tip is directed downward.
Switching when the compressed air is discharged from the first air spring 11
Lever 36a and, of the cab with one end and a link 36b which other end is pivotally mounted <br/> the tip is pivotally attached to the arm 36c secured to the cab 13 of the switching lever 36a Suspension
It is an improvement of the device. The characteristic configuration is that, when the cab 13 is tilted up and at least the center of gravity of the cab 13 approaches a vertical plane including the axis L of the lower pin 17,
Switching lever 3 when moving to the front of the vehicle 10 beyond the plane
The switching lever 36a, the link 36b, and the arm 36c are connected so that the distal end of the switch 6a is kept downward.

[0008]

When the hydraulic pressure cylinder 31 pushes up the bottom surface of the cab 13 and the cab 13 starts to tilt up, the cab 13 rises while maintaining a substantially horizontal state for a while, and the switching lever 36a moves the arm 36c and the link 36b. The compressed air in the first air spring 11 is gradually discharged upward through the first air spring 11 to be discharged. Thereafter, the cab 13 starts rotating around the lower pin 17, and the switching lever 36a gradually rotates downward. When the switching lever 36a becomes substantially horizontal, the discharge of the compressed air in the first air spring 11 stops. When the center of gravity G of the cab 13 approaches a vertical plane including the axis L of the lower pin 17, the tip of the switching lever 36a rotates below the horizontal direction,
Compressed air is supplied into the first air spring 11 and the cab 13
Even if the center of gravity G moves forward beyond the vertical plane including the axis L, the cab 13 does not suddenly rotate in the tilt-up direction about the lower pin 17.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 to 3, the cab 13 of the cab-over type truck 10 has a pair of first cab lower surfaces.
The pair of side members 14a, 14a of the chassis frame 14 are mounted on the pair of side members 14a, 14a via the air springs 11, 11, and the rear lower surface is mounted on the side members 14a via the second air spring 12 and the floating arch 16. (FIG. 3). Further, the cab 13 has its lower front end pivotally supported by the front end of the pair of side members 14a, 14a via the torsion tube 19 and the pair of lower pins 17, 17, so that the cab 13 can be tilted up around the lower pins 17, 17 ( 2 and 3).

At the front ends of the pair of side members 14a, a pair of lower brackets 1 protruding upward, respectively.
8 and 18 are fixed. These lower brackets 18,
A torsion tube 1 extending in the vehicle width direction is provided at the upper end of 18.
9, a pair of link levers 2 respectively fixed to both ends
The front ends of 1, 21 are respectively fitted. A pair of lower pins 17, 17 provided on the same axis L as the torsion tube 19 are inserted into the lower brackets 18, 18, and the link levers 21, 21, respectively. Lower pin 17,1
Reference numeral 7 is inserted so as to be non-rotatable with respect to the link levers 21 and 21 and rotatably with respect to the lower brackets 18 and 18. The torsion tube 19 is formed by a metal tube,
Compressed air is stored therein (FIG. 2).

A pair of cab frames 13b, 13b extending in the traveling direction of the truck 10 are fixed to the bottom surface of the floor panel 13a of the cab 13, and a pair of cab frames 13 opposed to a pair of link levers 21, 21.
A pair of substantially T-shaped upper brackets 22, 22 are fixed to the bottom surfaces of b, 13b, respectively (FIGS. 2 and 3).
The lower end of the upper bracket 22 is rotatably attached to the approximate center of the link lever 21 via a shaft 22a.
A rubber stopper 2 is provided on the upper surface of the rear end of the link lever 21 to prevent the cab 13 from rotating backward from the horizontal state.
5 protrudes toward the upper bracket 22 (FIG. 3). At the front ends of the upper brackets 22, 22, a pair of upper pins 23, 23 extending in the vehicle width direction are provided.
The upper pins 23, 23 and the lower pins 17, 17 are connected by shock absorbers 24, 24. The first air springs 11, 11 are mounted between the upper surfaces of the link levers 21, 21 and the lower surfaces of the front ends of the upper brackets 22, 22 (FIGS. 2 and 3).

A rear arch 26 is provided on a pair of side members 14a, 14a facing the rear end of the cab 13. Cab frame 13b on both sides of rear arch 26
The rear bracket 27 is fixed so as to face. The floating arch 16 is attached to the rear bracket 27 via the second air spring 12. First air spring 11
The second air spring 12 is formed in a cylindrical shape by superimposing two layers of nylon cords woven in a cloth shape in a biased manner and sandwiching the two cords with three rubbers, and when compressed air is supplied to the inside, the cylindrical air spring 12 is formed in a circumferential direction. The height is increased almost without expanding. A distal end of a plunger 31a of a hydraulic cylinder 31 having a proximal end pivotally connected to the side member 14a is pivotally connected via a shaft 32 near the rear end of the upper bracket 22 (FIG. 3).

The first air spring 11 is connected via a torsion tube 19 and a front leveling valve 36 to an air tank (not shown) in which compressed air is stored. The side members 14a, 14a are attached to a cross member 14b provided on the side members 14a so that the longitudinal direction thereof is directed vertically. A base end of a switching lever 36a is pivotally connected to the valve 36, and one end of a link 36b whose total length can be adjusted is pivotally connected to a distal end of the switching lever 36a. The other end of the link 36b is an arm 3 suspended from the bottom of the floor panel 13a.
6c. (FIGS. 1 and 2). The front leveling valve 36 is a four-port two-position switching valve. This valve 36 stops the supply and discharge of compressed air to the first air spring 11 when the switching lever 36a is substantially horizontal,
When the switching lever 36a rotates upward and the tip of the lever is positioned above the horizontal direction, the compressed air in the first air spring 11 is discharged, and the switching lever 36a rotates downward so that the tip of the lever is below the horizontal direction. Is located in the first air spring 1
1 is supplied with compressed air.

The inclination angle of the link 36b is determined by the cab 13
In a tilt-up state, the tip of the switching lever 36a is kept downward at least until the center of gravity G of the cab 13 approaches the vertical plane including the axis of the shaft 22a and crosses the vertical plane including the axis L. Is set to

The operation of the cab suspension device thus configured will be described with reference to FIGS. When the hydraulic cylinder 31 pushes up near the rear end of the upper bracket 22 (FIG. 3) and the cab 13 starts to tilt up, the center of gravity G of the cab 13 is positioned rearward of a vertical plane including the axis of the shaft 32 at the tip of the plunger 31a. Since it is located, the cab 13 rises while maintaining a substantially horizontal state. At this time,
Since the lower surface of the front end of the cab 13 is separated from the chassis frame 14, the switching lever 36a is connected to the arm 36c and the link 36.
Then, the compressed air in the first air spring 11 is discharged gradually (FIG. 4). The upward movement while maintaining the horizontal state of the cab 13 ends when the total length of the shock absorber 24 reaches the maximum, and thereafter the cab 13 starts rotating about the axis L of the torsion tube 19 and the lower pin 17. When the cab 13 rotates about the axis L,
Since the lower surface of the front end of the cab 13 approaches the chassis frame 14, the switching lever 36a gradually rotates downward. When the switching lever 36a becomes substantially horizontal, the discharge of the compressed air in the first air spring 11 stops. When the center of gravity G of the cab 13 approaches a vertical plane including the axis of the shaft 22a, the switching lever 3
6a is rotated below the horizontal direction, and the first air spring 11
Even if the center of gravity G of the cab 13 moves forward beyond the vertical plane including the axis of the shaft 22a, the cab 13 suddenly rotates in the tilt-up direction about the shaft 22a. I will not do it. Cab 1
Also, when the center of gravity G of 3 moves forward beyond the vertical plane including the axis L, the tip of the switching lever 36a is kept downward (FIG. 5). There is no rapid rotation in the tilt-up direction. As a result, the cab 13 smoothly tilts up in a stable state. Further, after the center of gravity G of the cab 13 exceeds the vertical plane including the axis L and before the cab 13 reaches the maximum tilt angle, the switching lever 36a rotates further downward (FIG. 6).

In the above embodiment, a hydraulic cylinder is used as the fluid pressure cylinder. However, the invention is not limited to this, and an air cylinder may be used as the fluid pressure cylinder.

[0017]

As described above, according to the present invention, the base end of the switching lever is rotatably mounted on the front leveling valve mounted on the chassis frame, and one end is pivotally mounted on the distal end of the switching lever. pivoted to the other end of the link arm that is fixed to the cab, the vertical plane including at least the cab center of gravity axis of Roapin in a state where the cab is tilted up
The front of the switch lever is kept downward when moving beyond this vertical plane and ahead of the vehicle.
Switching lever so that, since the connecting link and the arm, the first air during tilting up without a cut valve
The discharge of compressed air from the spring can be limited. This
As a result, it is possible to smoothly tilt up while maintaining the cab in a stable state. Further, since it is not necessary to use a cut valve, the number of parts and the number of piping steps can be reduced, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken along the line AA of FIG. 2 showing a cab suspension device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG. 3;

FIG. 3 is a sectional view taken along line DD of FIG. 2;

FIG. 4 is a sectional view of a portion C in FIG. 1 showing a state in which the cab has started to tilt up.

FIG. 5 shows a state in which the cab is tilted up and the center of gravity of the cab has reached a vertical plane including the axis of the lower pin.
Sectional drawing of C section.

FIG. 6 is a sectional view of a portion C in FIG. 1 showing a state in which the cab has tilted up and the cab has reached a maximum tilt angle.

FIG. 7 is a cross-sectional view showing a conventional example and corresponding to FIG.

FIG. 8 is a sectional view corresponding to FIG. 4 and showing the conventional example.

FIG. 9 is a sectional view corresponding to FIG. 5 and showing the conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Truck (vehicle) 11 1st air spring 12 2nd air spring 13 Cab 14 Chassis frame 16 Floating arch 17 Lower pin 31 Hydraulic cylinder (fluid pressure cylinder) 36 Front leveling valve 36a Switching lever 36b Link 36c Arm G Cab center of gravity L Lower pin Axis of

Claims (1)

(57) [Scope of request for utility model registration] 1. A front end lower surface is mounted on a chassis frame (14) of a vehicle (10) via a first air spring (11), and a rear end lower surface is mounted on a chassis frame (14).
Tilt-up pivotally supported by the chassis frame (14) via a lower pin (17) mounted via an air spring (12) and a floating arch (16) and provided with a lower front end extending in the vehicle width direction. A possible cab (13), a fluid pressure cylinder (31) provided between the chassis frame (14) and the cab (13) and rotating the cab (13) around the lower pin (17). The first air spring attached to the chassis frame (14);
A front leveling valve for supplying and discharging compressed air air tank (11) (36), said first air spring when the tip base end to the front leveling valve (36) is rotatably mounted is directed upward
(11) The compressed air is supplied and the tip is directed downward
When the compressed air is discharged from the first air spring (11),
A switching lever (36a) which, re, one end of which is pivotally connected to the arm (36c) secured to the pivotally mounted other end said cab (13) to the tip of the switching lever (36a)
Contact the suspension system of the cab that includes a link (36b)
In a state where the cab (13) is tilted up, at least the center of gravity of the cab (13) approaches a vertical plane including the axis (L) of the lower pin (17), and then crosses the vertical plane and crosses the vehicle (1).
(0) so as to keep the tip of the switching lever (36a) downward.
a) a suspension device for a cab, wherein a link (36b) and an arm (36c) are connected.