GB2042688A - Rotary Cylindrical Valve - Google Patents

Abstract

The valve comprises a cylindrical carrier (4) which is journalled in a cylindrical bore (2) of a housing (1) and is provided with a transverse bore in which is housed a cup-shaped valve member (12) of which the base (14) is provided with a series of recesses (33, 34, 35) providing selective communication between pairs of four ports (23, 24, 25, 39) provided in the bore wall, in dependence upon the angular position of the carrier. The valve member is guided by a spigot end (18) which is received in a bore (19) in the cup base (14) which admits pressure fluid to the interior of the cup to bias the cup base into sealing engagement with the housing bore wall. <IMAGE>

Description

SPECIFICATION Rotary Valves This invention relates to rotary valves and is particularly, but not exclusively, concerned with rotary valves for vehicle hydraulic systems.

Power hydraulic systems are increasingly used in vehicles for braking and steering, and the provision of a power hydraulic source in a vehicle mades it possible to consider operating auxiliary equipment, such as wind-screen wipers and window winders, by hydraulic actuators fed from the power source. We have found that there is a lack of suitable valves for controlling the fluid supply to such auxiliary equipment. Currently available valves tend to be relatively large, cumbersome or expensive, and the present invention stems from attempts to produce more suitable valves for this purpose.

The invention is concerned with a valve of the kind in which a valve member is carried by an angularly movable valve member carrier located in a bore in a valve housing, and the valve member controls the inter-connection of various ports located in the bore wall.

British Specification No. 553,261 discloses a valve of this kind arranged as a reversing valve for controlling the interconnection of four ports which are orientated at 900 with respect to one another, but in that valve it is necessary to employ two valve members and the valve member carrier needs to be turned through 900 to bring about a reversing action.

According to the invention a rotary valve comprises a housing provided with a cylindrical wall defining a bore of circular cross-section, a valve member carrier located in the bore and mounted for angular movement about the axis of zhe bore, actuating means for controlling the angular position of the carrier, a valve member located substantially within a recess in the carrier provided with a part-cylindrical outer surface of complementary shape to said wall, means for biassing in use the valve member radially outwardly of the recess to hold said outer surface in sealing engagement with said wall, the valve member being provided with openings in said outer surface and with at least two fluid connections which are isolated from each other and which permanently connect pairs of said openings, the housing being provided with at least three passages communicating permanently with respective ports in the wall, and the arrangement being such that pairs of said ports are selectively interconnected by said openings and fluid connections in dependence upon the angular position of the carrier relative to the housing.

The fluid connections in the valve member may comprise bores in the valve member which terminate in said openings, but preferably recesses in the outer surface of the valve member provide said fluid connections and said openings.

Since the valve member is provided with more than one fluid connection it is possible to arrange the ports in the housing wall within a relatively small arc about the axis of the bore to provide a reduced range of movement of the carrier.

The valve may be made of relatively simple construction which facilitates the use of plastics mouldings for the housing, carrier and valve member.

The means biassing the valve member may comprise resilient means and/or the arrangement may be such that in use the valve member is urged radially outwardly with respect to the carrier by fluid pressure supplied through one of said ports.

The carrier preferably comprises a cylindrical block which is journalled in the housing bore.

The valve member is preferably cup-shaped, the base of the cup facing radially outwardly of the carrier and being of part-cylindrical shape to provide the part-cylindrical outer surface.

The centre of the base of the valve member is preferably slidably located by the free end of a radially directed spigot which is preferably an integral part of the carrier.

Conveniently a coil spring for biassing the cup radially outwardly of the carrier is located on the spigot.

When such a spigot end is used to locate the base of the cup the spigot end is preferably received in a through-bore in the base, and the clearance between the spigot end and the wall of the through-bore is used to supply pressurised fluid from one of said ports to the interior of the cup to urge the cup outwardly of the carrier.

When the carrier comprises a cylindrical block the housing bore is preferably-a through-bore and the block is preferably located axially of that bore by an integral flange on one end of the block and by a lever secured to the other end of the block, the flange and the lever abutting opposite side faces of the housing. Thus connection of the lever to the block holds the block captive to the housing.

The housing is preferably adapted to have a spigot and socket coupling with a mounting member which is conveniently provided with a further fluid passage arranged to connect with one of the passages in the housing.

Preferably the mounting member is formed with the spigot, and said one passage in the housing terminates in the base of the socket.

The connection between the further passage in the mounting member and the corresponding passage of the housing is preferably sealed by a gasket which is also adapted sealably to close the ends of drillings which provide portions of the other two passages of the housing.

The mounting member may constitute part of a fluid actuator supplied with pressure fluid by the rotary valve, or the actuator may be remote from the valve and the mounting member.

The spigot of the mounting member may conveniently comprise one end of the body of an actuator of the telescopic strut kind, the spigot replacing the conventional closure cap.

In a preferred construction the housing wall is provided with first, second, third and fourth ports, in a first angular position of the carrier the first and second ports are connected by a first passage of the valve member passages, and the third and fourth ports are connected by a second passage of the valve member passages, and in a second angular position of the carrier the first and third ports are connected by the first passage, and the second and fourth ports are connected by the second passage.

Such a construction is suitable for controlling the supply of a pressure fluid from a power hydraulic source to the opposing chambers of a double-acting hydraulic actuator. In a preferred system the first port is permanently connected to the power hydraulic source, and the second and third ports are permanently connected to the respective chambers of the actuator, the fourth port being permanently connected to an hydraulic reservoir The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:: Figure 1 is a longitudinal cross-section on the line 1-1 of Figure 2 of a rotary valve in accordance with the invention and showing, in an unassembled condition, the spigot of a mounting member; Figure 2 is a view looking from the left in Figure 1 and half-sectioned on the line 2-2 of Figure 1; Figure 3 is a transverse section of the valve on the line 3-3 of Figure 1; Figure 4 is a partial view looking in the direction of the arrow A in Figure 1; Figure 5 is a view of the valve member of the valve of Figure 1 looking from left in Figure 1; and Figure 6 is a view corresponding to Figure 5 but of a modified valve member.

With reference to Figures 1 and 3 the valve comprises a moulded plastics valve body 1 of substantially uniform transverse width and of generally truncated egg-shape viewed from one side as in Figure 1. At its larger end the body 1 is provided with a transverse through bore 2' defined by a cylindrical wall 2, and at its smaller end the body 1 is provided with a longitudinally stepped blind bore 3 directed radially of the through-bore 2'.A valve member carrier in the form of a moulded plastics cylindrical block 4 is a close rotating fit in bore 2' and is provided at one end with a radial flange 5 abutting one side face 6 of the housing 1, and at its other end with a transverse bore 7 in which is retained a lever 8, the lever 8 being inserted through the bore 7 after assembly of the block 4 to the housing to retain the block 4 captive to the housing 1 by engagement of the lever with opposite side face 9 of the housing 1.

Block 4 is provided with a radially extending cylindrical bore 11 of annular cross-section in which a moulded plastics cup-shaped valve member 12 is radially slidabie and which defines a radially extending spigot 1 3 integral with the remainder of the block 4. The cup-shaped valve member 12 comprises a base 14 of circular outline as viewed in the longitudinal direction but of part-cylindrical shape complementary to that of housing wall 1 so as to be continuous with the cylindrical surface of the block 4, and a cylindrical side wall 1 5 which is a sliding fit in bore 11.

Spigot 1 3 has a solid-cylindrical portion 1 6 connected to a frusto-conical portion 1 7 terminating in a spigot end 18 of cylindrical shape and received with clearance in a hole 1 9 passing centrally through the base 14 of valve member 12 to assist in location of the valve member 1 2 radially of bore 11. There is sufficient clearance of spigot end 18 in hole 19 to provide permanent fluid communication between the exterior of base 14 and an annular pressure space 20 defined between the interior of valve member 12 and spigot 1 3. It will be appreciated that pressurisation of space 20 produces a force on the valve member 12 urging it radially outwards into sealing engagement with housing wall 2.This force is augmented by that of a coiled compression spring 21 located over spigot 13 and engaging at one end with the base of bore 11 and at its other end with an internal step 22 in valve member 12.

As shown in Figures 1 and 2, the housing 1 is provided with three parallel longitudinally extending drillings 23, 24 and 25 leading from the blind end of housing bore 3 and breaking through hqusing wall 2 adjacent to valve member 12 which controls their selective interconnection.

The drillings 23, 24 and 25 are orientated at a common angle with respect to the rotational axis of block 4, but it will be appreciated that in other embodiments of the invention the arrangements of the drillings could be different. Drillings 23 and 25 are blanked off in use at their outer ends by an annular gasket 26, shown in Figure 1 displaced from its assembled position, but are broken into by further drillings 27 and 28 respectively extending normally to drillings 23 and 25 and providing ports for connection to opposing chambers 27' and 28' of a double-acting hydraulic actuator 47.

A spigot 29 of a mounting member is adapted to be received within housing bore 3 to sandwich gasket 26 between the free end 30 of the spigot and the blind end of bore 3. Spigot 29 is provided with a bore 31 axially aligned with drilling 24 for direct communication therewith. In this case the mounting member is remote from the actuator controlled by the valve, and bore 31 is connected to a high pressure hydraulic source 44 supplied by a pump 45. Spigot 29 is secured in bore 3 in use by pins forced through holes 32 which intersect bore 3.

The outer part-cylindrical face of base 14 of valve member 12, as shown in Figure 5, is formed with three recesses 33, 34 and 35 for providing selective communication between drillings 23, 24 and 25. Recess 34 consists of two horizontal channels 36 and 37 extending in opposite directions from the opposite ends of a vertical channel 38. When the block 4 and valve member 1 2 are in the neutral angular position shown in Figure 1, in which spigot end 1 8 is opposite drilling 24, drillings 23 and 25 are both isolated from drilling 24 and from each other, since, as shown in Figure 5, the drillings 23 and 25 are each sealed by the lands which separate the various recesses. In this condition of the valve both chambers 27' and 28' are isolated from the fluid supply 44.

Angular movement of the block 4 in the clockwise direction of Figure 1 from the neutral position will bring channel 36 into register with the drilling 23 so that channels 36 and 38 connect drilling 23 to the drilling 24 to supply pressurised fluid to the chamber 27' fed from drilling 27. Recess 35 will also have been brought into register with drilling 25.

Recesses 33 and 35 communicate permanently with a further drilling 39 which extends parallel to drillings 27 and 28 and breaks through housing wall 2 to connect with the clearance space between block 4 and housing wall 2. Thus the angular movement of the block has brought drilling 25 and 39 into communication by way of recess 35. In this case drilling 39 is connected to an hydraulic reservoir 46, so that the chamber 28' is connected to reservoir 46.

On angular movement of the block 4 in the opposite direction from the neutral position, drilling 24 and 25 are brought into communication by channels 37 and 38, and drilling 23 is connected to drilling 39 by way of recess 33.

Suitable stops 43, shown in Figure 4, for the lever are integrally moulded on the sideface 9 of the housing to limit the angular movement of block 4 to an amount equal to the angular displacement between channels 36 and 37.

As shown in Figure 3, the block 4 is provided with axially spaced annular recesses 51 in which are located respective O-rings 40 for sealing the clearance space between housing wall 2 and block 4.

Pressure space 20 permenently communicates with the pressure source by way of hole 19, channel 38 and drilling 24 so that the valve member 12 is held firmly in sealing engagement with housing wall 2 for the full range of angular movement of the block 4. In order to maximise the sealing force the widths of the lands between the recesses in the valve member are kept to a minimum, cut-outs 48 and 49 and peripheral recesses 50 are provided.

Figure 6 shows a modified configuration of recesses which is appropriate to an application of the valve where drilling 24 is directly connected to one chamber of a doubleacting hydraulic actuator, drilling 28 is connected to a high pressure source, and drilling 39 is connected as before to reservoir. Drilling 23 being connected to the opposite chamber of the actuator. Such an application is, for example, where spigot 29 constitutes one end of a conventional telescopic actuator. The modified valve member 12 is provided with a curved recess 41 which communicates permanently with drilling 25 supplied with pressure fluid, and with a cranked recess 42. In the neutral position of the block 4 the recesses are disposed relative to the drillings 23, 24 and 25 as shown in Figure 5, so that drillings 23 and 24 are isolated from each other and from drilling 25. Angular movement of block 4 in either direction from the neutral position results in one of the drillings 23, 24 being connected to drilling 25 by way of recess 41, and the other drilling 23, 24 being connected to reservoir by way of recess 42 and drilling 39.

With the valves described the connection of the clearance space between the valve member carrier 1 6 and the housing 1 to reservoir has the advantage of avoiding jamming of the carrier.

When the valve body is secured to an actuator the output of the actuator may be connected by suitable means to the valve actuating lever to provide some feedback if desired.

Claims (14)

Claims

1. A rotary valve comprising a housing provided with a cylindrical wall defining a bore of circular cross-section, a valve member carrier located in the bore and mounted for angular movement about the axis of the bore, actuating means for controlling the angular position of the carrier, a valve member located substantially within a recess in the carrier and provided with a part-cylindrical outer surface of complementary shape to said wall, means for biassing in use the valve member radially outwardly of the recess to hold said outer surface in sealing engagement with said wall, the valve member being provided with openings in said outer surface and with at least two fluid connections which are isolated from each other and which permanently connect pairs of said openings, the housing being provided with at least three passages communicating permanently with respective ports in the wall, and the arrangement being such that pairs of said ports are selectively interconnected by said openings and fluid connections in dependence upon the angular position of the carrier relative to the housing.

2. A rotary valve as claimed in Claim 1 in which the carrier comprises a cylindrical block which is journalled in the housing bore.

3. A rotary valve as claimed in Claim 1 or Claim 2 in which the valve member is cup-shaped, the base of the cup facing radially outwardly of the carrier and being of part-cylindrical shape to provide the part-cylindrical outer surface.

4. A rotary valve as claimed in Claim 3 in which the centre of the base of the valve member is slidably located by the free end of a radially directed spigot secured to the carrier.

5. A rotary valve as claimed in Claim 4 in which the spigot end is received in a through-bore in the base, and the clearance between the spigot end and the wall of the through-bore provides permanent communication between one of said ports and the interior of the cup.

6. A rotary valve as claimed in Claim 2 or any of Claims 3 to 5 each as appended to Claim 2 in which the housing bore is a through-bore, and the block is located axially of that bore by an integral flange on one end of the block and by a lever secured to the other end of the block, the flange and the lever abutting opposite side faces of the housing.

7. A rotary valve as claimed in any of the preceding claims in which the housing is connected by a spigot and socket coupling to a mounting member, the mounting member being provided with a further fluid passage which communicates with one of the passages in the housing through said coupling.

8. A rotary valve as claimed in Claim 7 in which the coupling comprises a spigot formed on the mounting member, and a socket formed in the housing.

9. A rotary valve as claimed in any of the preceding claims in which each fluid connection and its associated pair of openings in the valve member are constituted by a respective recess in the outer surface.

10. A rotary valve as claimed in any of the preceding claims in which the three ports are substantially axially aligned with one another.

11. A rotary valve as claimed in any of the preceding claims in which the housing wall is provided with first, second, third and fourth ports, in a first angular position of the carrier the first and second ports are connected by a first passage of the valve member passages, and the third and fourth ports are connected by a second passage of the vaive member passages, and in a second angular position of the carrier the first and third ports are connected by the first passage, and the second and fourth ports are connected by the second passage.

12. A rotary valve as claimed in claim 11 in which the arrangement such that in a third angular position of the carrier the four ports are isolated from one another.

13. A power hydraulic system comprising a rotary valve as claimed in Claim 11 or 12 wherein the first port is permanently connected to a power hydraulic source, the second and third ports are permanently connected to the respective chambers of a double-acting hydraulic actuator, and the fourth port is permanently connected to an hydraulic reservoir.

14. A rotary valve substantially as described with reference to Figures 1 to 5 of the accompanying drawings.

1 5. A rotary valve as claimed in Claim 14 but modified substantially as described with reference to Figure 6 of the accompanying drawings.

1 6. A power hydraulic system as claimed in Claim 1 3 and substantially as described with reference to the accompanying drawings.