GB2339261A

GB2339261A - Vehicle engine mounting

Info

Publication number: GB2339261A
Application number: GB9814769A
Authority: GB
Inventors: Pascal Gerard Tournier
Original assignee: Draftex Industries Ltd
Current assignee: Laird Holdings Ltd
Priority date: 1998-07-08
Filing date: 1998-07-08
Publication date: 2000-01-19
Also published as: GB9814769D0; FR2781533A1

Description

1 2339261 MOUNTINGS The invention relates to mountings and in particular

to mountings for interconnecting two relatively movable elements such as a load and a support.

An example of such a mounting is found in vehicles where one element is formed by the body or chassis of the vehicle and the other element is the engine of the vehicle. The mounting is connected between the engine and the body and its purpose is to stabilize the upper end of the engine against excessive movement in response to abrupt changes in engine torque while permitting vertical movement. A known form of such a mounting comprises an elongate link carrying two rubber bushes, one at each end of the link. One end of the link is connected to the body by, for example, a bolt extending through one bush. A point on the engine is connected to the other end of the link by, for example, a pin extending through the other bush. The link extends generally horizontally. The bushes damp vibrations passing from the engine to the body, and the link provides high resistance to movement of the engine along an axis extending along the length of the link (i.e. generally horizontally). However, vertical movement of the engine is 2 not resisted: the link simply swings about the axis of the bolt or the pin to accommodate such movement.

Such mountings have found widespread use. Since they require the use of two bushes, however, this makes such mountings expensive and the cost of such mountings is difficult to reduce. In addition, there may be situations where such a link cannot be easily accommodated.

According to a first aspect of the invention, there is provided a mounting for interconnecting two relatively movable elements, comprising a connecting member for connection to one element, an elastomeric device held by the connecting member and receiving an attachment member associated with the other element and having a longitudinal axis, the elastomeric device providing greater freedom of movement of the attachment member in a f irst plane than in a second plane, the first and second planes being mutually inclined and including the axis of the attachment member.

According to a second aspect of the invention, there is provided a vehicle comprising a body and an engine, a mounting according to the first aspect of the invention being fixed to 3 the engine, and the body including an elongate member received by the elastomeric device.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which:- Figure 1 is a side elevation of a mounting for connecting an engine to a vehicle body, and Figure 2 is a section on the line II-II of Figure 1.

Referring first to Figure 1, the mounting comprises a connecting member 10 which may be cast f rom metal. The connecting member 10 includes a generally triangular web 11 having an arcuate flanged edge 12 extending between a first corner 13 and a second corner 14. The web 11 is thickened at the first corner 13 and the second corner 14 and each corner 13,14 is provided with a respective mounting hole 15 extending through the corner in a direction normal to the plane of the web 11.

4 Second and third edges of the web 11 are also flanged and lead to the third corner of the web 11 which is formed by a flanged circular crosssection bushing 16 having an aperture 17. The axis of the aperture 17 is parallel to the axis of the mounting holes 15. The aperture 17 carries a cylindrical metal bush 18 whose axis 19 is also parallel to the axis of the mounting holes 15,15 (and coincident with the axis of the aperture 17) The bush 18 carries an elastomeric element indicated generally at 20. The elastomeric element 20 is formed in one piece and includes an annular outer portion 21 which is bonded to the bush 18. The elastomeric element 20 also includes first and second portions 22,23 which project radially inwardly from diametrically opposite sides of the bush 18 and the outer portion 21. Each portion 21, 22 is thus supported by a respective support surface provided by the bush 18. Each portion 21,22 has a face 24 which lies in a plane parallel to the axis 19 of the bush 18. The two faces 24 are symmetrically arranged on opposite sides of the bush axis 19 and are separated by a gap 25. The length of the gap 25 thus lies on a first axis 26 normal to the bush axis 19 and parallel to the faces 24.

The first portion 22 and the second portion 23 each include a respective slot 27. Each slot extends through the associated first or second portion 22,23 in a direction parallel to the bush axis 19 between respective first and second side walls 28,29 of the first and second portions 22,23. This is best seen in Figure 2. In addition, each slot 27 is symmetrically arranged about a plane including the bush axis 19 and normal to the second axis 26. This plane defines a second axis 30.

As seen in Figure 2, each slot 27 is not of constant cross section along its length. Referring to Figure 2, each slot 27 narrows in cross-section from the first side wall 28 to a point about two thirds the way along the length of the slot 27. The cross-section of each slot 27 then increases to the second side wall 29.

The first and second portions 22,23 also have respective end walls 32 (see Figure 1) extending between the associated side walls 28,29 and lying in respective planes parallel to the first axis 26.

In use, the mounting is connected to the engine of a vehicle by bolts passing through the mounting holes 15. Because there are two spaced fixing points, the mounting is fixed rigidly to the engine, that is, in particular it cannot move angularly.

6 An attachment member 31 (see Figure 1), fixed to the body of the vehicle, is located between the faces 24 on the first and second portions 22,23 of the elastomeric element 20. This is also best seen in Figure 1. This member 31 may be formed by a simple tube or a cross-bar or trunnion. In this position, the axis of the member 31 is co-incident with the bush axis 19. When so mounted, the first axis 26 is generally vertical and the second axis 30 is generally horizontal.

The movement of the engine is in two principal directions. First there is a lateral movement resulting from increases in the torque outputted by the engine. Such movements are thus generally along the second axis 30. There can also, however, be vertical movements of the engine caused, for example, by the vehicle moving over an uneven surface.

The horizontal forces are countered by significant forces from the elastomeric material of either the first portion 22 and/or the second portion 23, as the portion 22,23 compresses in a direction parallel to the first axis 26. This compression can be controlled by adjusting the shape and size of the slots 27 shaped as shown in Figure 2 as described above. The mounting thus stabilizes the engine against lateral movement.

7 vertical forces do not meet such high resistance from the elastomeric member 20 due to the presence of the gap 25. The member 31 is thus free to move along the length of the gap 25 to accommodate vertical movement of the engine. The member 31 thus has greater freedom to move in a first plane including the axis of the member 31 and the first axis 26 and normal to the second axis 30 than it does in a second plane including the axis of the member 31 and the second axis 30 and normal to the first axis 26.

In general, the extent of the vertical movement will be accommodated within the length of the faces 24. In extreme circumstances, in a crash for example, the member 31 may tend to move beyond the ends of the faces 24. This is resisted by engagement of the member 31 with parts of the bush 18 covered by the elastomeric element 20 and opposite the ends of the gap 25. This is a significant safety feature preventing excessive movement of the engine causing significant damage.

Another advantage of the arrangement described above with reference to the drawings is the absence of any metal moving parts. This reduces the possibility of vibration due to such movement.

8 It will be appreciated that there are a number of changes that may be made to the arrangement as described above with reference to the drawings. The elastomeric element 20 is shown formed in one piece. It may, however, be formed in more than one piece. The connecting member 10 has been shown as being generally triangular, but this is only to allow it to fit in a particular vehicle/body engine position. It may be any suitable shape to fit other positions. The elastomeric element 20 is shown in an annular bush 18. The element 20 could be of any suitable shape to fit other positions. The elastomeric element 20 is shown in an annular bush 18. The element 20 could be of any suitable shape and be carried in any suitable mount.

The mounting need not be used in a vehicle; it could be used for any vibration isolating purpose.

The first and second planes need not be mutually at right angles. They could have any mutual inclination. This can be achieved by adjusting the positions of the first and second portions 22, 23 and by adjusting the shape of the faces 24. In this regard, the faces 24 need not be planar; they could have 9 some other shape to give a required freedom of movement to the member 31.

The slots 27 are optional. As an alternative, there may be more than one slot 27 in each portion 22,23.

It will also be appreciated that each portion 22, 23 may be replaced by two or more separate portions extending radially inwardly of the bush 18. 10

Claims

1. A mounting for interconnecting two relatively movable elements, comprising a connecting member for connection to one element, an elastomeric device held by the connecting member and receiving an attachment member associated with the other element and having a longitudinal axis, the elastomeric device providing greater freedom of movement of the attachment member in a first plane than in a second plane, the first and second planes being mutually inclined and including the axis of the attachment member.

2. A mounting according to claim 1 wherein the first plane is normal to the second plane.

3. A mounting according to claim 1 or claim 2 wherein the elastomeric device includes first and second spaced portions for receiving the member therebetween, each portion being so shaped as to resist movement of the attachment member in said second plane but not substantially to resist movement of the attachment member in said first plane.

11

4. A mounting according to claim 3 wherein each portion includes a face, the face of the first portion being opposite the face of the second portion with a gap therebetween for receiving the member, the first plane extending through said gap-

5. A mounting according to claim 4 wherein said faces are planar, each face lying in a respective plane parallel to the first plane.

6. A mounting according to claim 4 or claim 5 wherein the first and second portions extend from respective first and second support surfaces of the connecting member, the first and second support surfaces facing one another in a direction including the second plane.

7. A mounting according to claim 6 wherein the support surfaces are arcuate parts of an annular aperture in said connecting member, the elastomeric device being received in said aperture.

8. A mounting according to any one of claims 3 to 7 wherein the first and second portions include respective slots 12 extending through f irst and second portions include respective slots extending through the associated portions in a direction parallel to the axis of the attachment member, each slot being disposed symmetrically about the second plane.

9. A mounting according to any one of claims 1 to 8 wherein means are provided for limiting the extent of the movement of the attachment member in said first plane.

10. A mounting according to claim 9 wherein the limiting means are formed by the connecting member.

11. A mounting according to claim 10 when dependent on claim 7 wherein the limiting means are provided by parts of the annular aperture opposite the ends of the gap between the faces of the first and second portions of the elastomeric device.

12. A mounting substantially as hereinbefore described with reference to the accompanying drawings.

13. A vehicle comprising a body and an engine, a mounting according to any one of claims 1 to 12 being f ixed to the 13 engine, and the body including an elongate member received by the elastomeric device.

14. A vehicle according to claim 13 wherein the elongate member is a circular cross-section pin.

15. A vehicle according to claim 14 wherein the pin is hollow.