GB2153449A - Apparatus for servicing vehicle fluid suspension elements - Google Patents

Abstract

A portable apparatus for servicing fluid suspension systems of motor vehicles, particularly motor cars, comprises a carrying frame structure (10) supporting (I) a pump (5), (II) a fluid supply conduit (11, 13) enabling fluid to be pumped by the pump (5) from a fluid source (6) to the system, (III) a fluid discharge conduit (15) for fluid discharge from the system, (IV) a by-pass conduit (20) interconnecting the upstream and downstream sides of the pump to enable the discharge of the system fluid via the pump (5), and (V) a set of valves (3) selectively operable to provide the desired flow path. When pumping fluid from the fluid source (6) to the system via the supply conduit (11, 13), the valves (3/1, 3/3) are open. During fluid discharge when de-pressurising the system, fluid flows therefrom via said discharge conduit (15) and open valves (3/3, 3/4). To pump out the system valves (3/2, 3/4) are opened and the pump (5) operated. Vacuum and pressure gauges (1, 2) are provided. <IMAGE>

Description

SPECIFICATION Apparatus for servicing vehicle fluid suspension elements The present invention relates to apparatus for servicing fluid suspension members and systems of vehicles, such as for example motor cars and commercial vehicles. More particularly, the apparatus serves forthefilling dehydrating and pressurisation of hydro-pneumatic shock absorber systems of vehicles, Fluid suspension systems are now well established in the motor vehicle art, such as for example the Hydrogas (RTM) system of British Leyland cars, and these systems frequently use hydropneumatic shock absorbers. For satisfactory operation ofthese sys tems,itisnecessarythata required level offluid be maintained in the system and thatthefluid be kept at the required pressure.If there is serious fluid leakage from the system, the vehicle suspension can be lost and it is only practicable to drive the vehicle in this condition for a relatively short distance, and then only over roads of reasonable condition (e.g. over enamelled roads). It is beneficial therefore, to have servicing equipment forvehicle fluid suspension systems, which equipment is readily portable to the location ofthe damaged vehicle, since this location may very well be remote from a garage or service station. It is also necessary on occasions to deaerate a hydropneumatic suspension system to remove air from the system and hydraulicfluid.

It is the principal object ofthe present invention to provide servicing apparatus for vehicle fluid suspension systems e.g. hydropneumaticshockabsorber systems which apparatus is convenient to use and readily portable.

According to the present invention apparatus for servicing fluid suspenion elements or systems of motor vehicles comprises an assemblage including a pump, a fluid supply conduitconnectableto a fluid source and enabling fluid to be pumped by said pump to the fluid element or system, a fluid discharge conduitfordischargeoffluidfromthe element or system; an additional by-pass conduit forthe dis charge of fluidfrom the element orsystem via said pump, and valve means to selectively control fluid floweitherto: a) a pumped fluid flowfrom the fliud source to the element or system via the supply conduit, or b) a fluid discharge fluid flow from the element or system via said discharge conduit and by-passing the pump; or c) a pumped dischargeflowfrom the element or system via the pump.

Preferably the supply conduit includes an input section to the pump and a delivery section from the pump.

Preferably the valve means include first and second valves in said input and delivery sections respectively, and furtherthird and fourth valves in the by-pass and discharge conduits respectively. In a preferred embodiment, portions ofthe by-pass conduit and the discharge conduit are common with parts of the input and delivery sections ofthe supply conduit respectively.The pump, conduits and valves of the assemblage can be mounted on a common support member.

Means can be provided to enable the discharge and by-pass conduits to return fluid to the fluid source.

An embodiment ofthe present invention will now be described by way of example with reference to the accompanying drawing which shows a schematic view of portable apparatus for servicing hydropneumatic suspension systems of motor vehicles.

More specifically, the apparatus S serves for the filling, dehydrating and pressurisation of hydrop neumaticshockabsorbersystems, and comprises an assemblage of parts mounted on a support plate 10.

The assemblage includes a hand pump Sthe inlet 12 of which is connected to a fluid supply line 11 and the discharge 14 ofwhich is connected to a delivery line 13 which can befluidlycoupledto a shockabsorber system (not shown) to be serviced. The supply line 11 is coupled at 1 6to a suitable pipeline 17 drawing fluid from a fluid container 6, while a discharge conduit 15 leads from the delivery line 13 and can be coupled at 18to asuitablepipline 19 returning fluid to the fluid container 6.A by-pass line 20 is connected between the delivery and the supply lines 13,11 and manually operable control valves 3/1,3/2,3/3 and 3/4 are intercalated appropriately in the supply line 11, by-pass 20, delivery line 13 and discharge conduit 15 respectively. The delivery 13 includes a pressure gauge 2 while a vacuum gauge 1 senses vacuum conditions in by-pass 20. A non-return valve 4 is located on the discharge side of pump 5.

The apparatus can be set to provide the following servicing processes.

1. Fill Process The following functions are carried out. Valve 3/1 in the system will be opened to allow fluid to flow via valve 3/1 and supply line 11 into the inlet 12 of the pump 5. Operation of pump Swill compress the fluid toflowthrough valve 3/3 into the connection to the hydropneumatic system valve, -- valves 3/2 and 3/4 being closed.

2. Evacuate Certain hydropneumatic systems requirethesys- tem to be de-aired to remove airfrom the system and hydraulicfluid.

The following sequence is required to obtain this condition: Valve 3/1 will be closed and Valve 3/2 will be open to allowthe removal of air from the system and fluid on operation ofthe pump 5, by means ofthe by-pass 20 and the suction side 11 ofthe hand-pump Sand flow through the non-return valve 4 and fluid exit th rough valve 3/4. Valve 3/3 will be closed. The required vacuum achieved can be measured on the vacuum gauge 1 located in the by-pass 20. The normal vacuum required is between 25 - 27" Hg.

The drawing(s) originally filed (were) informal and the print here reproduced is taken from a later filed formal copy.

The claims were filed later than the filing date within the period prescribed by Rule 25(1) of the Patents Rules 1982.

3. Pressurize Generally, the system requires to be pressurized.

This is achieved by means ofthefollowing sequence: Valve 3/1 would be open to allow fluid flow to the suction side 11 of the pump 5. The fluid will then flow through the non-return valve 4 and out through valve 3/3, which would be open to allow pressurefluid delivered bythe hand-pump 5 into the connection of the hydropneumatic system. Valves 3/4 and 3/2 would be closed. The required pressure in the system will be indicated by the pressure gauge 2.

4. Depressurize To carry outthis operation, thefollowing sequence is taken: Valve 3/3 would be open and the reduction in pressure is achieved by means of valve 3/4. Pressure existing in the system would be indicated on pressure gauge 2. Fluid will be exhausted into fluid container 6 via valve 4 and discharge conduit 15. Valves 3/1 and 3/2will be closed.

The above processes enable correct fluid pressure conditions to be obtained in the hydropneumatic system.

The above apparatus of the present invention, provides readily portable apparatus for servicing vehicle hydropneumatic systems, which apparatus is convenient and satisfactory in operation.

Claims (8)

1. Apparatus for servicing fluid suspension ele mentsorsystem of motor vehicles comprising an assemblage including a pump, afluid supply conduit connectable to a fluid source and enabling fluid to be pumped by said pump to the fluid element or system, a fluid discharge conduitfor discharge offluid from the element or system; an additional by-pass conduit forthe discharge offluid from the elementorsystem via said pump, and valve means to selectively control fluid flow either two a pumped fluid flow from thefluid source to the element or system via the supply conduit; ora fluid discharge fluid flowfrom the element or system via said discharge conduit and by-passingthepump; ora pumped discharge flow from the element or system via the pump.

2. Apparatus as claimed in claim 1, wherein the supply conduit includes an input section to the pump and a delivery section from the pump.

3. Apparatus as claimed in claim 1 or 2, wherein the valve means include first and second valves in said input and delivery sections respectively, and further third and fourth valves in the by-pass and discharge conduits respectively.

4. Apparatus as claimed in any one of the preceding claims, wherein portions ofthe by-pass conduit and the discharge conduitare common with parts of the in put and delivery sections ofthe supply conduit respectivley.

5. Apparatus as claimed in any one of the preced- ingclaims,whereinthe pump, conduits and valves of the assemblage are mounted on a common support member.

6. Apparatus as claimed in any one of the preced- ing claims,wherein means are provided to enable the discharge and by-pass conduits to return fluid to the fluid source.

7. Apparatus as claimed in claim 2, wherein a pressure gauge is connected to the delivery section while a vacuum gauge is connected to the by-pass conduit.

8. Apparatus for servicing fluid suspension elements or systems of motor vehicles substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.