GB2355780A

GB2355780A - A resilient support for a vehicle exhaust system

Info

Publication number: GB2355780A
Application number: GB9925322A
Authority: GB
Inventors: Patrice Fort; Philippe Souyri; Ludovic Chauvet; Philippe Drumel; Gonzague Barrier
Original assignee: Draftex Industries Ltd
Current assignee: Laird Holdings Ltd
Priority date: 1999-10-26
Filing date: 1999-10-26
Publication date: 2001-05-02
Also published as: GB9925322D0

Abstract

A resilient support comprises resilient material providing two support parts (12A, 12B) with fixing holes (14, 16) for receiving hooked attachment means respectively connected to the vehicle body and to the exhaust system. The support parts (12A, 12B) are adhesively (or frictionally) secured within a frame (30). In this way, the exhaust system is resiliently supported. In addition, a damping member (28), made of rigid material of predetermined mass, is attached to the frame (30) so as to beneficially affect its damping characteristics. In particular, the dynamic rigidity of the support is increased at low vibration frequencies. The frame (30) limits the maximum extension of the support parts (12A, 12B) and also provides some protection against the effects of heat from the exhaust system.

Description

2355780 RESILIENT SUPPORTS The invention relates to resilient supports.

Resilient supports embodying the invention, and to be described by way of example on more detail below, are for supporting a vibrating structure in a motor vehicle such as an exhaust system (the silencer or exhaust pipe for instance).

According to the invention, there is provided a resilient support for resiliently supporting the vibratable member from an adjacent structure, comprising a resilient part made of resilient material and adapted to be attached between the vibratable member and the structure, and damping means made of rigid material and having a predetermined mass and mounted on the resilient part to increase the dynamic rigidity of the support at low vibration frequencies.

According to the invention, there is further provided a resilient support for resiliently supporting a vibratable member from an adjacent structure, comprising first and second end portions made of resilient material, the end portions respectively including means for attaching them respectively to the vibratable member and to the structure, two arms made of the resilient material and extending parallel to each other and spaced apart and 2 integrally extending between and interconnecting the two end parts, and damping means made of rigid material and of predetermined mass and connected to the resilient material by being mounted on the two arms whereby to increase the dynamic rigidity of the support at low vibration frequencies.

Resilient supports embodying the invention, and for supporting part of the exhaust system in a motor vehicle, will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which:

Figure 1 is a side view of one of the supports; Figure 2 is a side view of a modified form of the support of Figure 1; and Figure 3 is a graph for explaining the operation of the supports of Figures 1 and 2.

The resilient support 10 of Figure 1 is for resiliently supporting or suspending part of the exhaust system, such as an exhaust pipe or silencer, of a motor vehicle, from the body or chassis of the vehicle. The support 10 comprises two resilient support parts 12A,12B made of elastomeric material such as rubber or other strong resilient material and each preferably made by 3 a moulding process. The rubber is moulded to provide through holes 14 and 16 for receiving stiff metal attachment hooks. Thus, a f irst metal hook passes through the bore 14 and is attached to a f ixed point on the body or chassis of the vehicle. A second stiff metal hook passes through the bore 16 and is attached to the relevant part of the exhaust system.

The through bores 14 and 16 are respectively formed in enlarged regions 18 and 20 of the support parts 12A,12B. Each support part 12A,1213, has two integral arms 18A,18B and 20A,20B. The distal ends of these arms are secured, as by adhesive, to the inside walls of a frame 30 at points C,D, E and F. The frame 30 is rectangular but can be any other suitable shape and supports a damping member 31. The frame 30 and the damping member 31 can be made of metal.

In use, the resilient support parts 12A,12B resiliently supports the exhaust system, allowing it to move relative to the vehicle 1 body in response to movements of the engine and to changes of direction of the vehicle caused by the road contour.

The damping member 31 damps vibratory movement of the exhaust system. The mass of the damping member 31 is determined in accordance with the characteristics of the resilient material of the resilient parts 12A,12B and the characteristics of the part 4 of the exhaust system which is being supported. Figure 3 is a graph showing the relationship of the dynamic rigidity (Newtons per millimetre) of the support against the vibrating frequency (Hertz). The curve shows the effect of the damping member 31 on the performance of the support. The dynamic rigidity has a peak at a low frequency, about 70Hz, and thus provides high rigidity at this low frequency and effective damping of vibrations.

The frame 30 limits the maximum stretching which can take place of the resilient support parts 12A,12B. The frame also provides some protection for the parts 12A,12B against the effects of heat from the exhaust system. The gaps A and B allow limited longitudinal compression of the resilient parts 12A,12B towards each other. When the compression is such that the gaps A and B are closed, the stiffness of the support is significantly increased.

At the positions C,D,E and F, the surfaces are parallel to the directions in which traction and compressive forces are applied to the resilient material during operation of the support. Therefore, the resilient material is primarily subjected to shear forces.

Figure 2 shows a modified form of the support shown in Figure 1. Here, the support parts 12A and 12D are secured in position not by adhesive but by frictional forces, the parts 12A and 12B being compressed sufficiently to enable them to be inserted into their respective spaces, and then allowed to resile. The parts 12A,12B can have any desired shapes.

Claims

6 CLAIMS

1 A resilient support for resiliently supporting a vibratable member from an adjacent structure, comprising resilient material adapted to be attached between the vibratable member and the structure to be alternately stretched and compressed by the vibrations of the vibratable member, and damping means made of rigid material and having a predetermined mass and mounted on the resilient material to increase the dynamic rigidity of the support at low vibration frequencies.

2. A support according to claim 1, in which the resilient material comprises first and second separate support parts for respective connection to the vibratable member and the structure.

3. A support according to claim 1 or 2, in which the damping means includes embracing means embracing the resilient material whereby to limit the latter's maximum extension. i

4. A support according to claim 3, in which the resilient material is secured to the damping means by adhesive.

S. A support according to claim 2, in which the damping means includes embracing means embracing the first and second support parts and each support part has two surfaces which are in contact 7 with the embracing means and are adhesively secured thereto by the adhesive.

6. A support according to claim 2, in which the damping means includes embracing means embracing the first and second support parts and the support parts are secured by friction.

7. A support according to claim 6, in which each support part has two surfaces which are forced into frictional contact with the embracing means by compression of the resilient material.

8. A support according to any one of claims 5 to 7, in which the surfaces extend substantially parallel to the directions in which the resilient material is stretched and compressed by the vibrations.

9. A resilient support for resiliently supporting a vibratable member from an adjacent structure, comnprising first and second separate support parts made of resilient material, the support parts respectively including means for attaching them respectively to the vibratable member and to the structure, and damping means made of rigid material and of predetermined mass and embracing and supporting the two support parts spaced apart in the directions in which the vibratable member vibrates relative to the structure, whereby to increase the dynamic 8 rigidity of the support at low vibration frequencies.

10. A support according to claim 9, in which the damping means defines two spaces for respectively receiving the support parts.

11. A support according to claim 10, in which the support parts are secured in the spaces by adhesive.

12. A support according to claim 11, in which each support part has two surfaces which are in contact with the embracing means and are adhesively secured thereto by the adhesive.

13. A support according to claim 12, in which the two support parts are secured in the spaces by friction.

14. A support according to claim 13, in which each support part has two surfaces which are forced into frictional contact with the embracing means by compression of the resilient material..

15. A resilient support, substantially as described with reference to Figure 1 of the accompanying drawings.

16. A resilient support, substantially as described with reference to Figure 2 of the accompanying drawings.