GB2065826A

GB2065826A - Vehicle suspension device

Info

Publication number: GB2065826A
Application number: GB8036971A
Authority: GB
Original assignee: Tokico Ltd
Current assignee: Tokico Ltd
Priority date: 1979-11-20
Filing date: 1980-11-18
Publication date: 1981-07-01
Also published as: JPS5681248U; DE3043662A1; JPS6035810Y2; GB2065826B

Abstract

A vehicle suspension device comprises a hydraulic damper 1 including a vertical cylinder 2 and a piston rod 4 slidably extending out of the cylinder, and an air spring unit including a flexible tubular diaphragm 12 having an inner wall mounted on the cylinder, an outer wall mounted on a tubular support member 9 secured to the extending end of the piston rod, and a rolling wall. A cylindrical housing 11 is mounted on the cylinder and extends along its outer circumference, and the free end of the inner wall of the flexible diaphragm is secured to the housing, rather than to the actual cylinder of the damper. The housing is mounted on the cylinder via a bearing 10, so that the diaphragm cannot be mounted in a twisted condition. <IMAGE>

Description

SPECIFICATION Vehicle suspension device This invention relates to a vehicle suspension device for use in, such as passenger cars, trucks or the like and, particularly to a vehicle suspension device of the kind consisting of a hydraulic damper including a cylinder and a piston rod extending outwardly of the cylinder through one end of the cylinder, and an air spring unit including a flexible tubular wall member and receiving therein pressurized gas such as air.

Conventionally, the flexible tubular wall member has an inner tubular wall with the free end of which being directly secured to the cylinder of the hydraulic damper, an outer tubular wall surrounding at least a part of the inner tubular wall and the free end of which being secured to a skirt portion of a cup-shaped member secured to the extending end of the piston rod, and a rolling wall formed between the outer and inner walls.

However, in securing the inner wall of the tubular wail member to the outer circumference of the cylinder of the hydraulic damper, the cylinder will be deformed, thereby impairing the function of the hydraulic damper. Further, the tubular wall member is sometimes secured to the cylinder and the cup-shaped member in a twisted condition with respect to the longitudinal axis thereby impairing the durability of the tubular member.

Further, in some cases, the free end of the inner wall of the tubular wall member is secured to a reduced diameter upper end portion of the cylinder, and the tubular wall member extends along the outer surface of the cylinder which inclines relative to the longitudinal axis of the cylinder, thereby impeding the smooth rolling movement of the tubular member.

An object of the present invention is to solve the problems aforementioned and, according to the invention, a cylindrical housing is mounted on the cylinder to surround a part of the outer circumference of the cylinder of the hydraulic damper, and the free end of the inner tubular wall of the flexible wall member is secured to the housing so that the inner tubular wall extends along the cylindrical outer surface of the housing.

Preferably, the housing is rotatably and sealingly mounted on the cylinder of the hydraulic damper.

The invention will further be explained in conjunction with the attached drawings exemplifying two embodiments of the invention.

In the drawings: Fig. 1 is a partially sectional elevational view of a vehicle suspension device according to the invention, and Fig. 2 is a view similar to Fig. 1 but showing a second embodiment of the invention.

A vehicle suspension device 21 shown in Fig. 1 comprises a hydraulic damper 1 including a cylinder 2 and a piston rod 4 extending outwardly of the cylinder 2 through one end portion 3 of the cylinder 2. As shown in the drawing, the diameter of the end portion 3 is reduced as compared with the major portion of the cylinder 2. There is provided on the extending end of the piston rod 4 a mounting ring 6 for mounting the piston rod 4 of the hydraulic damper 1 on such as a body of a vehicle, and a mounting ring 7 is secured to the lower end of the cylinder 2 to mount the cylinder 2 on such as a wheel of the vehicle. A cap member 8 is also secured the extending end of the piston rod 4 and a rigid supporting tube 9 is secured to the cap member 8 to extend downwardly therefrom.

The cap member 8 and the supporting tube 9 constitute a cylindrical support member as defined in the specification.

According to the invention, a cylindrical housing 11 is fitted on the upper portion of the cylinder 2 and extends downwardly from the upper end portion 3 to cover the major portion of the outer circumference of the cylinder 2. The cylindrical housing 11 is formed of a rigid material and has a generally uniform outer diameter, and an inner peripheral surface generally conforming with that of the outer surface 2a of the cylinder 2 but being spaced therefrom by a small clearance 11 a. A bearing 10 is provided between the cylinder 2 and the housing 11 so that the housing 11 can rotate around the axis 5 of the cylinder 2.

Preferably, the bearing 10 is a needle roller bearing, a ball bearing or a plane bearing formed of a synthetic resin. An O-ring 1 5 is also provided between the cylinder 2 and the housing 11.

A flexible tubular wall member 12 is secured to the housing 11 and to the cylindrical support member 8, 9 to form a pressurized air chamber 13. The tubular wall member 12 is formed of a flexible material such as rubber, and consists of an outer wall 1 2a, an inner wall 1 2b and a rolling wall 1 2c formed between the outer and inner walls. One end of the tubular wall member 12 or the free end 17 of the outer wall 1 2a is secured to the inner peripheral surface of the cylindrical support member 8, 9 by utilizing a ring 18, and the other end of the tubular wall member 12 or the free end 19 of the inner wall 1 2b is secured to the upper end of the outer circumferential surface of the housing 11 by utilizing a ring 20. Preferably, a radially inward force is applied on the ring 20 for tightly pressing the tubular wall member 12 against the housing 11.

A piping 1 6 is connected to the pressurized air chamber 1 3 to supply or exhaust pressurized air into or from the chamber 13. The piping 16 is connected with a source of pressurized air (not shown) through a suitable valve (not shown).

The hydraulic damper 1 may be of any desired type such as a single tube type or a dual tube type and, therefore, the detailed description thereof is omitted.

In the vehicle suspension device 21 according to the invention, the tubular wall member 12 is secured to the housing 11 by utilizing the ring 20, however, the pressing force applied on the ring 20 is received by the rigid housing 11 and is not transmitted to the cylinder 2, thus, it is possible to avoid the deformation of the cylinder 2 which would impair the function of the hydraulic damper 1. The housing 11 can rotate freely around the cylinder 2 in assembling the suspension device 21, thus, the tubular wall member 12 is not secured to the support member 8, 9 and the housing 11 at a twisted condition. Further the housing 1 has a uniform outer circumference, thus, the inner wall 1 2b of the tubular walt member 12 is smoothly guided along the housing 11.Further, the housing 11 surrounds and covers the upper end portion of the cylinder 2, thus, as compared with the case wherein the upper end portion of the cylinder 2 has a reduced diameter as shown in Fig. 1 and the upper end of the inner wall 1 2b is secured to the cylinder 2 at the location downwards of the reduced diameter portion, it is possible to locate the upper end 19 of the inner wall 1 2b upwards by a distance S, thereby reducing the overall length of the tubular wall member 12.

Fig. 2 shows a second embodiment of the invention, wherein parts corresponding to the first embodiments are depicted by the same reference numerals and detailed description is omitted. In Fig. 2, a vehicle suspension device 22 according to the invention comprises a mounting member 23 securing the lower end of the cylinder 2 of the hydraulic damper to a steerable wheel (not shown), and the upper end of the piston rod 4 is secured to a body of a vehicle (not shown) through a mounting member 24 having an anti-friction bearing 30. The cylinder 2 is rotatable around the axis 5 of the cylinder relative to the body of the vehicle. A coil spring 27 acts between a retainer 25 secured to the cylinder 2 and a spring seat 26 secured to the extending end of the piston rod 4.

The spring 27 cooperates with pressurized gas enclosed in the chamber 1 3 to suspend the boyd of the vehicle and performs the damping function cooperating with the hydraulic damper 1. Further, the spring 27 transmits the rotating force between the cylinder 2 and the piston rod 4. In the embodiment, a bearing 28 is disposed between the upper end surface of the cylinder 2 and the housing 11, and a seal ring 1 5 is provided between the cylinder 2 and the housing 1, and a seal ring 29 seals the upper end of the chamber 13. Further, in the embodiment, a bumping rubber 31 and a bumping rubber receiving member 32 are provided in the chamber 13.

As described heretofore, the flexible tubular member can, according to the invention, be mounted on the suspension device at a substantially untwisted condition, so that the reliability of the tubular member can be improved.

Further, the housing can effectively prevent the deformention of the cylinder.

Claims

1. A vehicle suspension device comprising a hydraulic damper including a cylinder and a piston rod extending outwardly of the cylinder through one end thereof, a cylindrical housing mounted on said one end of the cylinder and surrounding a part of the outer circumference of the cylinder, a cylindrical support member having a closed end attached to the extending end of the piston rod, and a flexible tubular wall member with one end being connected to the cylindrical support member and the outer end being connected to the housing to define, cooperating with said housing and the cylindrical support member, an air chamber.

2. A vehicle suspension device as set forth in claim 1 wherein a bearing is provided between the cylinder and the housing so that the housing is rotatable relative to the cylinder, and a seal ring is provided between the housing and the cylinder.

3. A vehicle suspension device as set forth in claim 1 wherein the piston rod extends vertically upwards of the cylinder, and the flexible tubular wall member is connected to the upper end of the housing.

4. A vehicle suspension device as set forth in claim 1 wherein said housing has a smooth cylindrical outer surface.

5. A vehicle suspension device as set forth in claim 1 wherein the bearing is a needle roller bearing.

6. A vehicle suspension device as set forth in claim 1 wherein the bearing is a ball bearing.

7. A vehicle suspension device as set forth in claim 1 wherein the bearing is a plane bearing formed of a synthetic resin.

8. A vehicle suspension device substantially as hereinbefore described with reference to, and as illustrated in, Figure 1 or Figure 2 of the accompanying drawing.