JP2868699B2 - Cab air 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 cab air suspension device.

[0002]

2. Description of the Related Art In order to ensure a good ride comfort of a vehicle, a suspension using an air spring is well known (Japanese Utility Model Laid-Open No. 5-69860). An example of the rear suspension of a truck cab shown in FIG. 3 will be described. Reference numeral 1 denotes a mount bracket that supports the rear portion of the cab, 2 denotes a U-shaped frame bracket that straddles a chassis frame 3, and has a shock absorber between them. An air spring 4 is interposed.

[0003] The air spring 4 is mounted on the mount bracket 1.
The base end is located on both ends of the mount bracket 1 side,
The other end is attached to each of the trapezoidal brackets 5 projecting to the side of the frame bracket 2 by pin connection. In order to limit the roll angle of the cab, stoppers 6 are formed at both ends of the mount bracket 1,
Cushion rubber 7 which comes into contact with trapezoidal bracket 5
Is provided.

The leveling valve 8 controls the supply and exhaust of air to and from the air spring 4 so as to maintain the vehicle height in a constant horizontal state. The leveling valve 8 is fixed to the frame bracket 2 and its sensing rod 8a is It is connected to the mount bracket 1 side. Air spring 4
Each is provided with a dedicated tank 9 for absorbing surge pressure, and these are also attached to a trapezoidal bracket 5 located near the air spring 4.

[0005] Reference numeral 10 denotes a lock mechanism (having a hook 10b that automatically engages with the pin 10a as the cab is tilted down) to lock the center of the rear surface of the cab to the pin 10a of the mount bracket 1 at a tilt-down position. Denotes an operating lever for releasing the locked state, and 12 denotes an operating unit (located on the rear surface of the cab and attached to the chassis frame 3 side) for controlling a hydraulic pressure supplied to a hydraulic cylinder for tilting the cab.

[0006]

By the way, one surge tank 9 is arranged on the air spring 4 one by one, but this requires a mounting space for the surge tank 9 at a place adjacent to the air spring 4, respectively. There is a problem that it greatly restricts the degree of freedom in designing peripheral parts.

An object of the present invention is to solve such a problem rationally.

[0008]

SUMMARY OF THE INVENTION Therefore, the present invention relates to an air suspension device which supports the front, rear, left and right sides of a cab on a chassis frame side via air springs. A hollow member extending in parallel with the frame is attached to the center of the frame, and two airtight chambers are defined by partition walls, and these airtight chambers are connected to air springs on the left and right rear portions of the cab as surge tanks.

[0009]

According to this, since two surge tanks are integrated into one hollow member, the number of parts and space required for the mounting can be reduced. Also, since the hollow member is attached to the sub-frame that straddles the chassis frame,
From both ends, each of the airtight chambers can be connected to the left and right air springs with short piping.

[0010]

In FIG. 1, reference numeral 20 denotes a mount bracket at the rear of the cab, and 21 denotes a frame bracket extending over a chassis frame (not shown), and an air spring 22 is interposed therebetween. The air spring 22 is fixed to both ends of the mount bracket 20 at the base end, and the other end is supported by the frame bracket 21 via a cushion rubber 23 (which restricts the cab roll angle).

The frame bracket 21 is formed in an arch shape similar to the mount bracket 20, and is connected to the chassis frame via leg portions 21a on both sides of the central portion thereof. In order to assemble the shock absorber 24, a bracket 25 is provided on the upper end side of each leg 21a, and a corresponding seat surface 26 is provided on the mounting bracket 20.
Formed.

A hollow member 27 as a surge tank for the air spring 22 is attached to the center of the mount bracket 20 so as to extend in parallel with the center. The hollow member 27 is formed by joining two steel pipes 27a each having a rectangular cross section as shown in FIG. 2 and sandwiching a partition wall 27b therebetween, and sealing both ends with the partition walls 27b, so that a required volume is formed therein. Are defined.

The three partition walls 27b are formed of pressed parts having the same shape, and the hollow member 27 is extremely easily manufactured by a simple structure in which these are combined with the two steel pipes 27a. Connectors 29 are attached to both ends of the hollow member 27, and left and right air springs 22 are connected to two airtight chambers 28 via pipes 30. Reference numeral 27c denotes a stay of the hollow member 27.

In order to maintain the vehicle height in a constant horizontal state, a reservoir is connected to a pipe 31 passing through a connector 29 to the air spring 22 via a leveling valve 32 (to control the supply and discharge of air). Is fixed to the mount bracket 20 side contrary to the conventional example, and its sensing rod 32a is connected to the frame bracket 21 side.

With this configuration, one hollow member 2
7 functions as left and right surge tanks in the two airtight chambers 28, so that not only the number of surge tanks but also the number of parts required for installation can be reduced and space can be saved, and peripheral parts adjacent to the air spring 22 can be saved. The degree of freedom in design can be secured.

Since the hollow member 27 has a simple structure as described above and the airtight chamber 28 can be easily formed, it is advantageous in terms of processing cost. Also, since the hollow member 27 is attached to the mount bracket 20 straddling the chassis frame, the airtight chamber 28 is separated from each end by the air spring 22.
Can be connected with short piping.

The hollow member 27 is a steel pipe 2 having a circular cross section.
7a, which may be attached to the frame bracket 21 side in parallel with the frame bracket 21.

[0018]

According to the present invention, in the air suspension device for supporting the front, rear, left and right sides of the cab on the chassis frame side via the air springs, respectively, the center of the subframe straddling in the vehicle width direction of the chassis frame at the rear portion of the cab. A hollow member extending parallel to this is attached to the portion, and two airtight chambers are defined by partition walls inside the hollow member. These hollow chambers are connected to air springs on the left and right rear portions of the cab as surge tanks. Since the two surge tanks are integrated, the number of parts can be reduced, the space can be rationalized, and the cost can be reduced, and the degree of freedom in designing peripheral parts can be secured. Further, by attaching the hollow member to the sub-frame, the piping with the air spring can be stored compactly.

[Brief description of the drawings]

FIG. 1 is a rear view and a plan view of an apparatus showing an embodiment of the present invention.

FIG. 2 is a front view and a side view of a hollow member.

FIG. 3 is a rear view of an apparatus showing a conventional example.

[Explanation of symbols]

 Reference Signs List 20 mount bracket 21 frame bracket 22 air spring 24 shock absorber 27 hollow member 28 airtight chamber 32 leveling valve

Claims (1)

(57) [Claims] In an air suspension device for supporting the front, rear, left and right sides of a cab on a chassis frame side via an air spring, a rear portion of the cab is provided at a central portion of a subframe straddling in a vehicle width direction of the chassis frame so as to be parallel to the center portion. An air suspension device for a cab, wherein an extending hollow member is mounted, two airtight chambers are defined by partition walls, and the airtight chambers are connected to air springs on the left and right rear portions of the cab as surge tanks.