GB2298699A - Valve for vehicle suspension - Google Patents

Description

A VALVE AND A VEHICLE SUSPENSION SYSTEM INCLUDING This nventon relates valves ana to vehicle e suspension systems including sucn valves.

According to one aspect of the invent on there is provided a vehicle fluid suspension system comprising first and second support means for supporting first and second wheels, third and fourth support means for supporting third and fourth weeps, and a source of fluid pressure, wherein the first and second support means are fluid support means and are oonnectable to each other and to said source y a valve, the valve having a single closing member, first and second ports connected to the first and second support means and a third port connected to said source, the closing member controlling the communication between the third port and the first and second ports.

According to another aspect of the invention there is provided a valve having a single closing member which in a closed position closes three ports from one another and in an open position permits communication between the three ports.

The closing member may take any suitable form: it may comprise a plunger and may be solenoid actuated.

In one embodiment, the valve comprises two ports closed from one another by a wall, the closing member being provided in the wall and sealing the third port such that opening the closing member opens the third port and also opens gap in the wall so that all three communicate.

n another emcoCimentf the waive comprises two ports, the ends of which are defined in a single seat to be closed together by the closing member in Os closed position. The seat surface which defInes the ends cr the ports may be substantially planar.

n a preferred embodiment, a bleed path is defined between at least two of the three ports. n the gas suspension system described, the valves for the front wheel struts are fired at regular intervals to enable the front wheel struts to achieve an equilibrium state. By providing a bleed path between ports leading to these two gas struts, a degree of equalisation can take place in between firing of the valve. Where the valve comprises two ports the ends of which are defined in a single seat to be closed together by the closing member In its closed position, the bleed path may comprise a channel defined in the seat and extending from the end of one of the said two ports to the end of the other said two ports. Preferably, however, the bleed path comprises a conduit extending between the said two ports.The conduit is preferably defined in a gasket of the valve. Where the valve comprises two ports closed from one another by a wall, the bleed path may comprise an aperture in the wall. The bleed path preferably has a minimum cross-section of O.lmm or less.

The valve Is preferably a pneumatic vase.

embodiments of the InventIon will tow be described by wav of example and with reference to the accompanying drawings, n which Figure 1 is a cut-away side view of a known valve; Figure 2 is a plan view of the seat of the known valve of Figure 1; figure 3 is a diaarammatic representation of a vehicle suspension system according to a first embodiment of the invention; Figure 4 is a cut-away side view of a valve in the embodiment of Figure 3; Figure 5 is a plan view of part of the valve of Figure Figure 6 is a plan view of part of a valve in a second embodiment of the invention; Figure 7 is a cut-away side view of the valve of a third embodiment of the invention;; Figure 8 is a plan view of part of the valve of Figure 7; and igure 9 is a cut-away side view partv in cross-section of a ave in a fourth emboamen f e invention.

The shown valve 10 shown in Figures : and 2 comprises an upright housing 12 of square plan cross-section. A closing member in the form of a solenoid actuated plunger 14 is arranged for vertical movement in the housing '2 and terminates in a downward facina diaphragm 16 of an elastomeric material . A base i8 s provided below the diaphragm 16 and seals across the housing 12. The base 18 includes a frustroconical projection 20 directed upwards towards the plunger 14. A gasket 22 Is provided between the base 18 and a distribution member 24.A central port 26 extends through the distribution member 24, the gasket 22 and the base 18 extending centrally of the housing 12 so that the end of the port 26 is at the top of the frustroconical part 20. A further port 28 is provided to one side of the frustroconical part 20 through the base 18, gasket 22 and distribution member 24. Where the valve 10 s usea in a vehicle pneumatic suspension system, the outer port 28 is connected to a source of compressed gas and the central port 26 leads to a gas suspension strut for a wheel. The plunger 14 as either in a closed position with the diaphragm 16 seated on the valve seat 30 provided by the upper surface of the frustroconical part 20 of the base 18, or in a retracted, open position with the diaphragm 16 spaced from the valve seat 30 so that the ports 26, 28 communicate.

erring to Figure 3, accsvainc to the first embodiment of the invention a vehicle suspension system comprises a reservoir 100 of pressurIzed air, first and second pneumatic suspension struts 102, 104 supporting the two front wheels of the venice, and third ano fourth pneumatic suspension struts 106, 108 supporting the two rear wheels of the vehicle.The reservoir 100 is connected to a manifoid 110 through an inlet valve 112, and the manifold 110 can be vented to atmosphere through an exhaust valve 114 wach of the rear suspension strts 106, 108 is connected to the manifold 113 through a rear wheel valve 116, 113. The two front struts 102, 104 are connected to -he manifold 110 by a single front wheel valve 120. A control unit 122 controls the operation of ai' of the vaives.

The valve 120 Is shown in Figures 3 and 4 and is similar to the known valve 10. Equivalent features will be identified by the same reference numerals and only differences from the known valve 10 will be described.

In the valve 120 a partition wall 34 is provided in the central port 25 to divide that port along its length into two separate ports 36, 38 of semi-circular cross-section.

Each of these ports 36, 38 is connected to one of the front struts 102, 104. The top of the partition wall 34 is level with the top of the frustroconical part 20 to provide a planar valve seat for the diaphragm 16. In this way, when the plunger 14 is in its closed position, the port 28, which is connected to the reservoir 100 15 closed cff from tne other two ports 36, 38 which are also closed off from one another. en the plunger 14 is move to its ten position with tne diaphragm 15 lifted trom the valve seat 30, the three ports 28, 36, 38 will al be i communication with one another. Therefore firing of the valve will connect the front struts 102, 104 to the reservoir 100.

This is achieved by the firing ci the single valve 120 ratner than by the controlled synchrorised firing of two valves 10 of the known type shown in Figures 1 and 2.

Figure 6 shows a further embodiment which again is based upon the known valve 10 shown in Figures 1 and 2.

Equivalent features will be identified with the same reference numerals and only the differences from the known valve will be described.

The central port 26 is replaced by two circular crosssection bores 40, 42 which extend through the distribution member 24, gasket 22 and base 18 terminating at the upper face 30 of the frustroconical part 20. As before, when the valve is used in a vehicle pneumatic suspension system, the ports 40, 42 may be connected each to one of the front wheel gas suspension struts so that firing of the valve connects the two struts to each other and to the pneumatic reservoir. A shallow semi-circular cross-section groove 44 is provided in the valve seat 30 linking the ends of the two ports 40, 42. The groove 44 provides a bleed path between the ports 40, 42.This enables a degree of equalisation to take trace between one front wheel gas struts when the valve is not actuated and one diaphragm O6 s resting on rhe seat 30.The groove needs to ne ot a small enough cross sectional area not to reduce significantly the rol stif-ness of the vehicle, winilst being large enough to allow the vehicle to be levelled using the rear struts under the control of the control uni. For example the semi-circular groove 44 may be 0 .5 mm in diameter.

It will be appreciated that the use of the valve shown In Figure 6 can enable the suspension system to be controlled to substantially the same degree as a system in which all of gas struts are independently connected to the manifold, but is cheaper and simpler because there are less valves in total A further embodiment is shown in Figures 7 and 8 which is again based on the known valve of Figures 1 and 2.

Equivalent features will be identified by the same reference numerals and only differences from the known valve will be described.

A partition wall 46 is provided in the housing 12 extending upwardly from the base 18. An additional port 48 is provided corresponding to the port 28 but on the opposite side of the frustroconical part 20. The partition wall 46 acts to seal the ports 28, 48 from one another when the plunger 14 is in a closed position with the diaphragm 16 on the valve seat 30 which also closes the port 26.

When the plunger 14 s movea to its open posit Ion, this opens the port 26 and also enables communIcation with and between the ports 28, 48 through the gap created in the partItIon wall 46 between the diaphragm 16 and the valve seat 30. A bleed path is provided in the form of an aperture 50 through the partition wall 46. The aperture 50 may be 0.35mm in diameter.

Figure 9 shows yet another embodiment which in this case is similar to the embodiment of Figure . he same reference numerais will be used for equivalent features ana only the differences from that embodiment will be described.

The groove 44 is not provided and instead a gap 52 is provided in the gasket 22 to provide a bleed path between the bores 40, 42. While the resilience of the diaphragm may lead to partial occlusion of the bleed path defined by the groove 44 in use of the valve of the embodiment of Figure 6, the gap 52 in the gasket 22 can be formed accurately and will provide a bleed path of known constant dimensions. A good seal at the valve seat can also be provided in the arrangement of this embodiment while it may be more difficult to provide a good seal in the embodiment of Figures 7 and 8.

Claims (1)

1. A vehicle fluid suspension system comprising first ana second support means for supporting first ana secona wheels, third and fourth support means for supporting third and fourth wheels, and a source of fluid pressure, wherein the first and second support means are fluid support means and are connectable to each other and to said source by a valve, the valve having a single closing member, first and second ports connected to the first and second support means and a third port connected to said source, the closing member controlling the communication between the third port and the first and second ports.

2 A system according to claim 1 wherein the third and fourth support means are fluid support means independentlv connectable to said source by second and third valves respectively.

3. k system according to claim 2 further comprising control means for controlling the valves, wherein the third and fourth support means are arranged to be on opposite sides of the vehicle, and the system further comprises control means arranged to control the second and third valves to control vehicle roll.

4. A system according to any foregoing z aim wherein the first ana second ports nave respective openings in a common valve seat in the valve ano tan be opened and closed simuitaneously by the movable member.

5. Z system according to any foregoing claim wherein a bleed passage is defined between the first and second ports to allow limited communication therebetween when the first and second ports are cut of from the third port by the movable member.

5. A valve having a single closing member which in a closed position closes three ports from one another and in an open position permits communication between the three ports.

7. A valve as claimed in claim 6 wherein the closing member is solenoid actuated.

8 A valve as claimed in claim 6 or claim 7 wherein the valve comprises two ports closed from one another by a wall having a gap therethrough, the plunger being movable between a closed position in which it blocks the gap and closes the third port, and an open position in which the gap and the third port are open so that all three ports communicate with each other.

9. A valve as claimed in claim 6 or claim 7 wherein the valve comprises two ports, the ends of which are defined in a single seat to be closed together cy the plunger in ciosea position.

10. Z valve as claimed -n claim 9 wherein the seat surface which defines the ends of the ports is substantaly planar.

11. A valve as claimea In any one of claims 6 to 10 wherein a bleed path is defined between at least two of the three ports.

12.A valve as claimed in claim 11 when dependent on claim 9 or claim 10 wherein the bleed path comprises a channel definea in the seat and extending from the end of one of the said two ports to the end of the other said two ports.

13.A valve as claimed in claim 11 when depencent on claim 9 or claim 10 wherein the bleed path comprises a conduit extending between the said two ports.

14. A valve as claimed in claim 13 wherein the conduit is defined in a gasket of the valve.

15. A valve as claimed in claim 11 when dependent on claim 8 wherein the bleed path comprises an aperture in the wall.

16. A valve as claimed in any of claims 11 to 15, wherein the bleed path has a minimum cross-sectional area of 0. 1 mm or less.

17. A valve as claimed in any preceding claim, wherein the valve is a pneumatic valve.

18. A vehicle suspension system according to any one of claims 1 to 5 wherein the valve is a valve according to any one of claims 6 to 17.

19.A valve substantially as described herein with reference to Figures 3 and 4, Figure 5, Figures 6 and 7 or Figure 8 of the accompanying drawings.

20.A vehicle suspension system substantially as described herein with reference to Figure 1, Figures 4 and 5, Figure 6, Figures 7 and 8 or Figure 9 of the accompanying drawings.