GB1602851A

GB1602851A - Device for fixing a control valve in position

Info

Publication number: GB1602851A
Application number: GB2284278A
Authority: GB
Original assignee: Wabco Fahrzeugbremsen GmbH
Current assignee: Wabco Fahrzeugbremsen GmbH
Priority date: 1977-06-30
Filing date: 1978-05-25
Publication date: 1981-11-18
Also published as: DE2729560B2; FR2396228B1; DE2729560C3; FR2396228A1; DE2729560A1

Description

(54) DEVICE FOR FIXING A CONTROL VALVE IN POSITION (71) We, WABCO FAHRZE-UGBREMSEN GMBH (formerly WABCO WESTINGHOUSE GMBH), a German Company, of Am Lindener Hafen 21, 3000 Hannover 91, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - The invention relates to a control valve with a valve member which can be fixed in at least one axial position and/or in at least one rotated position.

It is well known, in a spool valve, to provide the valve member itself with lockin grooves, notches, bores or the like in which locking elements engage in a particular preselected stop location. These known spool valves have the drawback that considerable lateral forces can act through the locking elements on the spool valve member, as a result of which there is a danger of mechanical and hydraulic jamming.

The present invention provides a control valve including a valve member and a device for fixing the valve member in at least one axial position and/or in at least one rotated position, the device including a sleeve which encircles the valve member with play and is connected to the valve member with play, and means for fixing the sleeve in at least one axial and/or in at least one rotated position.

By the use of a sleeve encircling the control valve member to form a positioning element which surrounds the control valve member with play and is at the same time connected to the control valve member with play, it is possible to fix the control valve member in certain positions without forces being exerted on the control valve member itself. In the case of a spool valve, the valve member can therefore be of a uniform diameter over its entire length and, in the locking plane, no longer needs to be provided with reduced portions of smaller diameter or with recesses which, in the previously-known spool valves, had to be able to compensate the warping tendencies of the material or abrasion marks occurring naturally as a result of the locking forces.

Consequently, through the use of the invention, manufacture of a spool valve can be simplfied and manufacturing costs can be reduced.

According to one advantageous form of the invention, the sleeve is guided in a guide bore of the control valve casing.

Preferably, the sleeve has a passage or a recess in which there is arranged a pin firmly secured to the control valve. If the sleeve is guided in a guide bore of the control valve casing it is advantageously guided with play that is less than the play between the sleeve and the valve member and less than the play between the pin and the passage or recess. This selection of the different clearances relative to one another makes it possible to ensure that the forces for fixing the sleeve in position are accommodated only by the sleeve and transferred to the guide bore. As a result, it can be arranged that lateral forces act neither on the control valve member nor on the pin of the control valve member so that any risk of jamming can be eliminated.

The means for fixing the sleeve in position may comprise a locking arrangement operable to press the sleeve resiliently in one or more radial directions towards a guide bore in which the sleeve is located.

The sleeve may have at least one recess in the outer surface thereof in which recess the locking arrangement is engageable to fix the sleeve.

The invention will now be explained in detail with reference to the accompanying drawings which illustrates embodiments, by way of example. In the drawings: Figure 1 shows a section through a spool valve designed according to the invention, Figure 2 is a section through a spool valve similar to that shown in Figure 1 but vertically thereto, show only that portion of the spool valve in which a device for positioning the valve member is arrnaged, Figure 3 is a plan view of the sleeve of the positioning device of the valve, Figure 4 is a section along the line A-A through the sleeve shown in Figure 3, Figure 5 is a section along the line B-B through the sleeve shown in Figure 3, Figure 6 is a side view of the sleeve shown in Figure 3, and Figure 7 is a part view of a section along the line C-C through the sleeve shown in Figure 6.

Reference will now be made to Figure 1 which shows a spool valve with a valve member 2 which is situated and guided in a valve casing 4. The spool valve member 2 is biassed in the axial direction and held in its neutral position by means of a spring 6. Its maximum stroke distance is determined by the spacing of the limiting faces of two spring plates 8 and 10, and the stroke may be set with the assistance of a screw joint 12 or adjusted by means of spacer washers 13. The spool valve member 2 may be brought by means of a device (not shown), against the force of the spring 6, into varaious stop locations in the axial direction and in the rotational direction.

To position the spool valve member in preselectable stop locations, a sleeve 14 is provided which is guided with play in a guide bore 14 and which, with the assistance of a locking slider 16 may be positioned in the selected stop locations. The locking slider 16 is loaded by forces in the locking direction by a spring 18 and pushes a ball 20 into contact with the sleeve 14.

The sleeve 14 has a transverse bore 21 in which a pin 22 of the spool valve member 2 is located with play.

By way of example, the setting of a certain axial position will be explained briefly. Using the above-mentioned device (not shown) for ajusting the spool valve, the spool valve member is moved downwards (in the drawing) against the force of the spring 6. The sleeve 14 is so designed that as a result of the displacement of the sleeve the ball 20 runs upwards on an ascending wedge face, provided by a wedgeshaped recess on the outer surface of the sleeve, until it passes the point 24 and takes up the stop location,, indicated by a broken line, relative to the sleeve.The ball is now located on the end face of the sleeve which is urged by the spring 6 towards the ball, as a result of which the spool valve is fixed in the axial direction because the sleeve is pushed to the right (as seen in Fig. 1) against the surface of the guide bore 15 and thus the sleeve is braced against this surface.

In the example under consideration a disengagement may be effected by introducing pressure into the bore 28, which moves the locking slider 16 back against the force of the spring 18, as a result of which the ball 20 can again assume the position shown in Figure 1 relative to the sleeve, the latter being brought above the ball (as seen in Fig. i) by the spring 6.

References will now be made to Figure 2, which shows more clearly the join between a sleeve 34 (corresponding to the sleeve 14 of Fig. 1) and a spool valve member 30 (corresponding to the valve member 2 of Fig. 1). A pin 32 is securely joined to the spool valve 30 and the sleeve 34 has a transverse bore 36 in which the pin 32 is located with play. It can also clearly be seen from Figure 2 that the sleeve 34 additionally encircles the spool valve member 30 with play and is moreover located with play in the guide bore 38. To ensure a completely accurate locking, in which no lateral guiding forces are exerted on the spool valve, the clearances are so selected that the play between the sleeve and the guide bore is less than the play between the sleeve and the spool valve and likewise less than the play between the pin and the transverse bore of the sleeve.

Reference will now be made to the remaining Figures 3 to 7, in which a sleeve similar to those already described for fixing spool valve positions is illustrated in greater detail and in different views and sections.

Figure 3 shows a plan view of the sleeve 40 i.e. a plan view of the side of the sleeve opposite the bevelled outer surface. The wedge-shaped recess is denoted by the reference numeral 42, and the lateral faces 44 and 46 can be seen and the basal face 48 of the wedge-shaped recess 42 extending at an angle relative to the outer surface of the sleeve. In the form of a phantom drawing there are furthermore shown a transverse bore 50 for receiving the pin, already mentioned, of the spool valve and drilled out cavities or recesses 52 and 54 for setting the rotated positions of the spool valve member which are located laterally to the wedge-shaped recess.

Figure 4 shows a section along the line A-A through the sleeve of Figure 3. This section is taken through the recess 54 of Figure 3. It can clearly be seen that the recess 54 has approximately the shape of a blind bore. The recess may also, however, be so shaped that there is an opening through the outer surface of the sleeve in the region of the bottom of the recess.

This opening must, however, be so small that the detent ball 20 mentioned in the description of Figure 1 does not come to rest against the surface of the spool valve, located within the sleeve, as the ball snaps into the recess 54, because otherwise lateral forces would be exerted on the spool valve.

Figure 4 shows particularly clearly the bevelled outer surface at the upper end of the sleeve, here indicated by the reference numeral 56, already mentioned in the description of Figure 1.

Figure 5 shows a section along the line B-B and through the sleeve shown in Figure 3, and thus a section through the wedge-shaped recess provided for the axial adjustment and locking of the spool valve member. In this cross-section, the basal face 48 of the wedge-shaped recess 42 extending at an angle relative to the outer surface 58 of the sleeve 40 can be clearly seen. The basal face 48 intersects almost with the bevelled outer surface 56 of the sleeve. The wedge-shaped recess 42 is preferably made by routing, wherein, in the embodiment illustrated, a portion of the outer surface i.e. in the area denoted by the reference numeral 58, is milled away.

This portion may be seen even more plainly in Figure 6, to which reference will be made hereinafter. Figure 5 also shows very clearly the arrangement of the transverse bore 50.

Figure 6 shows practically a plan view of the wedge-shaped recess 42 and the recesses 52 and 54 arranged laterally thereto. This illustration shows especially clearly the lateral wedge faces 44 and 46, the basal face 48 rising towards the inclined outer surface 56 and also the milled region 58 of the sleeve surface. The transverse bore 50 is again indicated by a broken line.

Finally, Figure 7 shows a section along the line C-C through the sleeve of Figure 6, wherein the arrangement of the lateral recesses 52 and 54 and of the wedge-shaped recess 42 is shown with the lateral wedge faces 44 and 46 and the basal face 48.

The sleeve shown in Figures 3 to 7 is, of course, not limited to the embodiment shown. For Example, as indicated by the broken lines in Figure 5, in the region of the inclined face 56 there may be provided recesses 60 for setting various rotated positions for a certain axial position.

The sleeve may also be provided in the axial direction with several wedge-shaped recesses of the type described so that several axial positions are possible. On a level with these axial positions there may be provided several rotated positions 60 in accordance with the above statements.

In principle, the recesses do not need to be arranged in the axial direction and/or in circular lines on the outer surface of the sleeve to set certain axial and/or rotated positions, but may also be arranged in any desired manner staggered with respect to one another, on helical lines etc.

A spool valve can be regulated with particular precision as a result of the design of sleeve described above. The arrangement makes it possible to ensure the accurate setting of preselectable stop locations and provides the opportunity for a combination with an automatic disengaging device, for example the slider and ball 16, 20 shown in Fig. 1. The locking forces may be applied hydraulically pneumatically, mechanically, manually or electromechanically while, the automatic disengagement may be effected as a function of certain regulating or control variables.

A positioning device as described above can be manufactured with little expenditure and, as regards operation, it has a slight hysteresis. Even at high pressure it is no longer possible for an hydraulic or pneumatic jamming to occur.

A positioning device in accordance with the invention can find application in hydraulic slide valves, pneumatic slide valves, mechanical slide valves or mechanical regulators or in combinations of the slide view and regulators listed.

WHAT WE CLAIM IS: - 1. A control valve including a valve member and a device for fixing the valve member in at least one axial position and/or in at least one rotated position, the device including a sleeve which encircles the valve member with play and is connected to the valve member with play, and means for fixing the sleeve in at least one axial and/or in at least one rotated position.

2. A control valve according to claim 1, in which the sleeve is guided in a guide bore of the control valve casing.

3. A control valve according to claim 1 or 2, in which the sleeve has a passage or a recess in which there is arranged a pin firmly secured to the valve member.

4. A control valve according to claim 3 when appendant to claim 2, in which the sleeve is guided in the guide bore, with play that is less than the play between the sleeve and the valve member and less than the play between the pin and the passage or recess.

5. A control valve according to claim 1, in which the means for fixing the sleeve in position comprises a locking arrangement operable to press the sleeve resiliently in one or more radial directions towards a guide bore in which the sleeve is located.

6. A control valve according to claim 5, in which the locking arrangement comprises a locking device resiliently biased into the fixing position and disengageable from that position.

7. A control valve according to claim 6, in which the locking device comprises a slider acting on a locking element to push the element towards the sleeve from the exterior thereof.

8. A control valve according to claim 7, in which the locking device is disengageable by pressure acting on the slider.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the sleeve, here indicated by the reference numeral 56, already mentioned in the description of Figure 1. Figure 5 shows a section along the line B-B and through the sleeve shown in Figure 3, and thus a section through the wedge-shaped recess provided for the axial adjustment and locking of the spool valve member. In this cross-section, the basal face 48 of the wedge-shaped recess 42 extending at an angle relative to the outer surface 58 of the sleeve 40 can be clearly seen. The basal face 48 intersects almost with the bevelled outer surface 56 of the sleeve. The wedge-shaped recess 42 is preferably made by routing, wherein, in the embodiment illustrated, a portion of the outer surface i.e. in the area denoted by the reference numeral 58, is milled away. This portion may be seen even more plainly in Figure 6, to which reference will be made hereinafter. Figure 5 also shows very clearly the arrangement of the transverse bore 50. Figure 6 shows practically a plan view of the wedge-shaped recess 42 and the recesses 52 and 54 arranged laterally thereto. This illustration shows especially clearly the lateral wedge faces 44 and 46, the basal face 48 rising towards the inclined outer surface 56 and also the milled region 58 of the sleeve surface. The transverse bore 50 is again indicated by a broken line. Finally, Figure 7 shows a section along the line C-C through the sleeve of Figure 6, wherein the arrangement of the lateral recesses 52 and 54 and of the wedge-shaped recess 42 is shown with the lateral wedge faces 44 and 46 and the basal face 48. The sleeve shown in Figures 3 to 7 is, of course, not limited to the embodiment shown. For Example, as indicated by the broken lines in Figure 5, in the region of the inclined face 56 there may be provided recesses 60 for setting various rotated positions for a certain axial position. The sleeve may also be provided in the axial direction with several wedge-shaped recesses of the type described so that several axial positions are possible. On a level with these axial positions there may be provided several rotated positions 60 in accordance with the above statements. In principle, the recesses do not need to be arranged in the axial direction and/or in circular lines on the outer surface of the sleeve to set certain axial and/or rotated positions, but may also be arranged in any desired manner staggered with respect to one another, on helical lines etc. A spool valve can be regulated with particular precision as a result of the design of sleeve described above. The arrangement makes it possible to ensure the accurate setting of preselectable stop locations and provides the opportunity for a combination with an automatic disengaging device, for example the slider and ball 16, 20 shown in Fig. 1. The locking forces may be applied hydraulically pneumatically, mechanically, manually or electromechanically while, the automatic disengagement may be effected as a function of certain regulating or control variables. A positioning device as described above can be manufactured with little expenditure and, as regards operation, it has a slight hysteresis. Even at high pressure it is no longer possible for an hydraulic or pneumatic jamming to occur. A positioning device in accordance with the invention can find application in hydraulic slide valves, pneumatic slide valves, mechanical slide valves or mechanical regulators or in combinations of the slide view and regulators listed. WHAT WE CLAIM IS: -

1. A control valve including a valve member and a device for fixing the valve member in at least one axial position and/or in at least one rotated position, the device including a sleeve which encircles the valve member with play and is connected to the valve member with play, and means for fixing the sleeve in at least one axial and/or in at least one rotated position.

9. A control valve according to claim

7 or claim 8, in which the locking element is ball-shaped.

10. A control valve according to any one of claims 5 to 9, in which the sleeve has at least one recess in the outer surface thereof, in which recess the locking arrangement is engageable to fix the sleeve.

11. A control valve according to claim 10, in which at least one wedge-shaped recess is provided in the outer surface of the sleeve, the depth of which recess decreases towards a stop location such that the locking arrangement acts to engage the sleeve at the stop location and to push the sleeve firmly against the wall of the guide bore.

12. A control valve according to claim 11, in which, in the axial direction of the sleeve, a plurality of consecutive wedgeshaped recesses is provided in the outer surface of the sleeve, the depth of each recess decreasing towards a respective stop location.

13. A control valve according to any one of claims 10 to 12, in which the sleeve has a plurality of recesses at circumferentiallyspaced locations in the outer surface thereof.

14. A control valve according to claim 13, in which the sleeve has a plurality of circumferentially-spaced recesses situated at the level of the, or an, axial stop location.

15. A control valve including a valve member and a device for fixing the valve member in at least one axial position and/ or in at least one rotated position, the device being substantially as described herein with reference to, and as shown in the accompanying drawings.