US3631888A

US3631888A - Regulation of operating fluid flow to and from a user device

Info

Publication number: US3631888A
Application number: US66490A
Authority: US
Inventors: Eckhard Anton; Werner Schlechtriem
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1969-08-28
Filing date: 1970-08-24
Publication date: 1972-01-04
Anticipated expiration: 1989-01-04
Also published as: AT306466B; FR2058412A2; JPS4946805B1; FR2058412B2; GB1293039A

Abstract

A cylinder chamber is provided in a housing and a passage for flow of operating fluid to and from a user device. A valve is arranged in this passage movable between a normal closed position and an open position in which it permits the flow of pressurized operating fluid to the user device through the passage. A valve control piston is operatively associated with the valve and movable in the cylinder chamber from a rest position via a first and a subsequent second intermediate position to a control position in which latter it displaces the valve to open position so as to permit operating fluid to flow from the user device through the passage. First and second control fluid inlets each communicate with the cylinder chamber for admitting respective streams of control fluid under pressure into the same. The first inlet communicates with the chamber in all positions of the piston. Control means on the piston serves to establish communication between the chamber and the second inlet when the piston moves from its first intermediate position to the second intermediate position, and for terminating this communication when the piston moves from the second intermediate position to the control position.

Description

United States Patent 885,459 4/1908 Engler et a1 1,591,671 7 /1962 Flanders Inventors Appl. No. Filed Patented Assignee Priority REGULATION OF OPERATING FLUID FLOW TO AND FROM A USER DEVICE v 10 Claims, 1 Drawing Fig.

US. Cl

Int. I

Field of Search References Cited UNITED STATES PATENTS 137/522, 91/26,9l/443, 137/5135, l37/630.15, 251/25, 251/48, 251/634, 251/635 F1611 15/18 2,382,457 8/1945 Wertman et a1. 91/26 FOREIGN PATENTS 216,400 7/1968 U.S.S.R. l37/630.15

Primary Examiner-Robert G. Nilson Attorney-Michael S. Striker ABSTRACT: A cylinder chamber is provided in a housing and a passage for flow of operating fluid to and from a user device. A valve is arranged in this passage movable between a normal closed position and an open position in which it permits the flow of pressurized operating fluid to the user device through the passage. A valve control piston is operatively associated with the valve and movable in the cylinder chamber from a rest position via a first and a subsequent second intermediate position to a control position in which latter it displaces the valve to open position so as to permit operating fluid to flow from the user device through the passage. First and second control fluid inlets each communicate with the cylinder chamber for admitting respective streams of control fluid under pressure into the same. The first inlet communicates with the chamber in all positions of the piston. Control means on the piston serves to establish communication between the chamber and the second inlet when the piston moves from its first intermediate position to the second intermediate position, and for terminating this communication when the piston moves from the second intermediate position to the control position.

REGULATION OF OPERATING FLUID FLOW TO AND FROM A USER DEVICE CROSS-REFERENCE TO RELATED APPLICATIONS A related application Ser. No. 63,720 vwas filed on Aug. 14, 1970 in the name of Werner Schlechtriem et al. under the title "Fluid Flow Regulating Apparatus.

BACKGROUND OF THE INVENTION The present invention relates generally to the regulation of operating fluid during its flow to and from a user device. More particularly it relates to an apparatus for regulating this flow of operating fluid.

The aforementioned related application describes an apparatus of the type here under discussion wherein a valve of the one-way type normally permits the flow of an operating fluid from a fluid supply to a user device, but not a return flow away from the user device. Because such return flow is sometimes required, the copending application provides for a control arrangement permitting opening of the valve and return flow of operating fluid away from the user device when this is desired. This opening is effected by movement of a control piston which displaces an actuating member, with the latter in turn acting upon the valve in a sense moving it to open position.

The related application in question attempts to provide a construction wherein the undesirably rapid movement of the control piston from its rest position to its control position in which it effects opening of the valvewhich rapid movement is common to all other prior art constructions of this type-by assuring that the control piston moves initially only slowly from rest position to operating position and is braked as it approaches the operating position.

It has been found, however, that even with this improved prior art construction it occurs in some circumstances that the control piston will impinge or impact upon its cylinder housing too strongly, with resultant undesired noise development; this is the case because the braking action exerted upon the control piston is not a positive action, that is the control piston is not actively deprived of some of the acceleration which was earlier imparted to it.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to overcome the aforementioned difficulty.

More particularly it is an object of the present invention to provide an improvement over the construction known from the aforementioned related application, and specifically such an improvement as will avoid the undesired noise development resulting from the above-discussed impacting of the control piston upon the cylinder housing.

At the same time it is an additional object of the present invention to provide a relatively uncomplicated and comparatively inexpensive construction affording this advantage.

In pursuance of the above objects, and others which will become apparent hereafter, one feature of the invention recites in an apparatus of the type in question, namely an apparatus for regulating the flow of an operating fluid to and from a user device which, according to one embodiment comprises, briefly stated, housing means having a cylinder member and a passage for flow' of the operating fluid to and from the user device. Valve means is provided in this passage and is movable between a normal closed position and an open position in which it permits the flow of pressurized operating fluid these inlet means the first inlet means communicates with the chamber in all positions of the piston means. Finally, control means on the piston means is operative for establishing communication between the chamber and the second inlet means upon movement of the piston means from its first intermediate position to the second intermediate position, and for terminating such communication upon movement of the piston means from the second intermediate position to the control position.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is an axial section through an apparatus according to the present invention illustrating one embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail it will be seen that we have provided a housing consisting essentially of two housing portions 1 and 16. These are connected with one another in a suitable manner and it is therefore justified to consider them as a single housing. The housing portion 1 is provided with a passage 11 having an inlet 12a for operating fluid and derived from an operating fluid supply which is diagrammatically illustrated, and an outlet 12b communicating with a diagrammatically illustrated user device to which the operating fluid is to be supplied. Intermediate the inlet 12a and the outlet 12b the passage 11 has an annular passage portion 11a.

The housing portion 16, and 10, is provided with a cylinder chamber 15 which is separated from the passage 11 by a wall portion la of the housing portion 1, with the wall portion 10 being provided with a bore or aperture 13.

A sleeve 2 is mounted in the passage 11 so as to be surrounded by the annular passage portion lla. It accommodates a cup-shaped valve body 3 of a main valve and is held in place by a cover or closure member 10 which is suitably secured to and constitutes a part of the housing portion 1. A shoulder 4 is provided in the sleeve 2 and configurated as the valve seat for the main valve body 3 which latter is provided in its bottom wall with a center bore 5 axially aligned with the bore or aperture l3 and penetrated by a pin 6 provided on a second smaller valve body 7 of a control valve. The valve body 7 abuts against a valve seat which is constituted by the edge of the bore 5. A shoulder 8 on the valve body 7 is engaged by one end of a compression spring ,or expansion spring 9 theiother end of which abuts against the cover 10, with the spring 9 constituting the closure spring or biassing means for both of the

valve bodies

3 and 7. I

As already pointed out, the bore or aperture 13 in the wall portion 1a is coaxial with the bore 5, and through the aperture 13 there extends slidably but sealtightly (the sealing means are illustrated but not separately identified because they are known) a pin or actuating portion 14. One end portion thereof is located in ,the passage 11 and the other end portion is located in the cylinder chamber 15. It is pointed out that when the member 14 is displaced towards the right as shown in the drawing, it will abut against and displace the

valve bodies

3 and 7 towards the right-hand side in direction oppositely the biassing action of the spring 9, by opening the control valve and the main valve which as is clearly shown, are both constituted as one-way valves which normally prevent the flow of fluid from the outlet 12b towards the inlet 12a of the passage 11, but permit the flow of fluid from the inlet 12a towards the outlet 12b.

Accommodated for slidable movement in the cylinder chamber 15 is a control piston 17. The housing portion 16 is in addition provided with a transverse bore 18 in which there is accommodated a member 19 having an enlarged cross-sectional portion 21 provided with longitudinal grooves or kerfs 20. This enlarged portion 21 is followed in the member 19 by a cylindrical portion 22 of lesser diameter which is located in a portion 23 of larger diameter of the bore 18. The portion 22 of the member 19 is hollow and, as illustrated, accommodates in its interior a spring 24 which abuts against a screw or similar element 26 which is threaded into'one end of the transverse bore 18 so that the spring 24 urges the member 19 against an adjusting screw which is threaded into the other open end of the bore 18 and which is identified with reference numeral 25. The juncture between the enlarged portion 23 and a portion 27 of the bore 18 constitutes, in cooperation with the kerfs 20 in the portion 21 of the member 19, a throttling gap for fluid.

Such fluid can be supplied from a diagrammatically illustrated control fluid supply via a normally closed valve 29a of any suitable construction to a channel 29 of the housing portion 1 which in turn communicates with a channel 28 provided in the housing portion 16. The channel 28 communicatesat its free end with that portion of the bore 18 in which the upper end of the spring 24 is located. On its way between its juncture with the bores 18 and 29 the passage 28 traverses and communicates with an annular groove or p ce 30 provided in an inner peripheral surface bounding the cylinder chamber and being identified with reference numeral 31.

As the drawing clearly shows (the piston 17 is partly broken away for clarity) the piston is provided with one or more radial bores 32 extending inwardly from an annular groove 39 provided in its outer circumferential face; the inner ends of the bores 32 communicate with one or more substantially axial bores 38 which terminate at the left-hand end face 36 of the piston 17. The circumferential groove 39 is bounded by two axially spaced sidewalls, of which the one which is closer to the end face 36 is identified with reference numeral 40 whereas the other one is identified with reference numeral 43. A portion 41 of the sidewall 40 is inclined radially outwardly as well as in axial direction of the piston 17 towards the end face 36 thereof. At its juncture with the outer circumferential surface of the piston 17 the portion 43 is bounded by an annular margin, 42 whereas the sidewall 43 is bounded at its juncture with the circumferential face of the piston 17 by an annular margin 44.

The drawing shows, further, that a bore or aperture 33 connects the interior of the cylinder chamber 15 to the left of the end face 36 of the piston 17, with the portion 27 of the transverse bore 18. At the opposite axial end of the cylinder chamber 15, that is the end closer to the wall portion 1a, a throttling leakage fluid bore 45 communicates with a pressureless space so that leakage fluid can escape from the chamber 15.

In normal operation of the illustrated device it is desired that operating fluid flow from the operating fluid supply via the inlet 12a and the passage 11 through and past the valve means to the outlet 12b and from there to the user device. In so doing it will first open the valve means against the biassing action of the spring 19 by lifting initially the valve body 7 off its seat, and shortly thereafter the main valve body 7 of the seat associated with the latter. The fluid can now flow through the bore 34 of the valve body 3 and the bore 35 of the sleeve 2 towards and beyond the outlet 12b to the diagrammatically illustrated user device.

lf, however, the direction of flow is to be reversed, then it is necessary that the one-way control action of the

valves

3 and 7 be overcome, because these valves do not normally permit flow of fluid from the user device in the direction towards the inlet 120 through the passage 11. This is accomplished by means of the control piston 17. When it is desired to effect such reverse flow through the passage 1 1, the valve 29a is opened to thereby establish communication between the pressurized control fluid supply and the passage 29. From there the fluid passes the channel 28 and enters into the bore 18 where the flow of fluid is throttled by virtue of the fact that the throttling gap, that is the small cross section of the valves permits no faster flow. The fluid then passes from the portion 23 to the portion 27, being throttled in so doing as just pointed out, and from there through the bore 33 into the cylinder 15. In the cylinder chamber 15 the thus admitted fluid exerts pressure upon the end face 36 of the piston 17, displacing the piston relatively slowly towards the right in the drawing, that is from the illustrated rest position towards the control piston in which it will be located directly adjacent or in abutment with the surface bounding the right-hand end of the cylinder chamber 15. Of course, during such movement-of the piston 17 it displaces the member 14 similarly towards the right whereby the right-hand end portion of the member 14 will press against the

valve bodies

3 and 7 and displace the same towards the right against the biassing force of the spring 9, thus opening the valves and permitting the flow of fluid from the outlet 12 through the passage portion 11a and the remainder of the passage 1 l to the inlet 12a thereof.

To reach this right-hand control position from the illustrated rest position, the piston 17 must proceed via two intermediate positions. In the first intermediate position, to which it moves slowly as pointed out before under the influence of the pressure fluid admitted into the cylinder chamber 15 through the bore 33 the margin 44 of the groove 39 in the piston 17 moves past the left-hand edge bounding the channel 30 so that the interior of the latter can now communicate with the groove 39. A substantial quantity of pressurized control fluid can now enter from the channel 28 through the channel 30 into the groove 39 and flow from there via the bores 32 and 38 towards the left-hand end face 36 of the piston 17, thereby imparting to the latter a substantially increased pressure and causing the piston 17 to move more rapidly towards the right. Such rapid movement continues until communication between the groove 39 and the channel 30 is again interrupted as the annular margin 42 moves towards the right past the downstream edge bounding the channel 30, that is the edge which is closer to the wall portion 1a. The provision of the inclined portion 41 which moves past this downstream edge just before communication is terminated, results in a gradual rather than an abrupt interruption of the communication between the channel 30 and the groove 39, so that the movement towards the right of the piston 17 is significantly braked or retarded. Once in the communication between the channel 30 and the groove 39 has been completely interrupted, that is once the annular margin 42 has moved past the right-hand edge of the channel 30, the only pressure which continues to act upon the end face 36 of the piston 17 in the sense tending to displace the latter further towards the right to its operating or control position, is exerted by the relatively weak flow of pressure fluid entering the cylinder chamber 15 via the bore 33. Any fluid which may have leaked into the cylinder chamber 15 upstream of the piston 17, that is towards the right of the piston 17 as seen in the drawing, flows out of the cylinder chamber 15 via the leakage fluid escape 45 and because of the breaking action exerted upon the piston 17 by the previously described structural measures the piston 17 will gently abut against the wall portion 1a or whatever surface bounds the right-hand end of the cylinder chamber 15, thereby reaching its final or control position in which it has opened the

valves

3, 7 completely.

It goes without saying, of course, that when it is decided that the

valves

3 and 7 are to return to their nonnal closed position in which they permit only one-way flow of operating fluid from the inlet 12a to the outlet 12b of the passage 11, it is merely necessary to close the valve 29a whereupon-in the absence of any further pressure acting upon the piston 17- the spring 9 displaces the

valve members

3 and 7 towards the left to closure position, thereby pushing the member 14 towards the left and in turn displacing via the member 14 the piston 17 past the second and first intermediate positions thereof back to the illustrated rest position. Fluid contained in the cylinder chamber 15 at the left-hand side of the piston 17 is expelled during such movement of the piston 17, and a nonillustrated escape passage for the fluid-for instance leading to a pressureless space, such as a reservoir or the like-is provided for this purpose. This passageof course in turn can be controlled by a one-way valve or other suitable control means which assure that operating or control fluid cannot escape through it when such fluid is intended to flow through the bore 33 in a sense displacing the piston 17 from rest position to control position. This, however, forms no part of the present invention.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus for regulating the flow of an operating fluid to and from a user device, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

, 1. An apparatus for regulating the flow of an operatingfluid to and from a user device, comprising housing means having a cylinder chamber, and a passage for flow of said operating fluid to and from said user device; valve means in said passage and movable between a normal-closed position and an open position permitting the flow of pressurized operating fluid to said user device; valve control piston means operatively associated with said valve means and movable in said cylinder chamber from a rest position via a first and a subsequent second intermediate position to a control position in which it displaces said valve means to open position for permitting a flow of operating fluid from said user device through said passage; first and second control fluid inlet means each communicating with said chamber for admitting into the latter respective quantities of control fluid under pressure, said first inlet means communicating with said chamber in all of said positions of said piston means; and control means on said piston means operative for establishing communication between said chamber and said second inlet means upon movement of said piston means from said first intermediate position to said second intermediate position, and for terminating such communication upon movement of said piston means from said second intermediate position to said control position.

2. Apparatus as defined in claim 1; and further comprising biassing means permanently urging said valve to said closed position thereof.

3. Apparatus as defined in claim 1, said chamber having a first and a remote second end, and said piston means being located at said first end when in said rest position and at said second end when in said control position; and wherein said first control fluid inlet means communicates with said chamber in the region of said first end.

4. Apparatus as defined in claim 3, said piston means having a circumferential face and an end face facing towards said first end of said chamber, and at least one channel extending from said circumferential face to said end face; and wherein said chamber is bounded by an inner peripheral surface and said second inlet means is provided in said inner peripheral surface intermediate said first and second ends of said chamber and arranged to communicate with said chamber via said channel of said piston means upon movement of the latter from said first intermediate position to said second intermediate position.

5. Apparatus as defined in claim 4, said channel comprising an annular radially outwardly open first channel portion and surrounding the longitudinal axis of the latter, and a second channel portion communicating with said first channel portion and having an open end at said end face of said piston means.

6. An apparatus as defined in claim 5, said annular first channel portion having a first annular margin axially farther spaced from, and a second annular margin axially closer to said end face of said piston means, said annular margins constituting said control means with communication between said second inlet means and said first channel portion being established in response to movement of said first annular margin past said second inlet means in direction toward said second end of said chamber, and being terminated in response to subsequent movement of said second annular margin past said second inlet means in said direction.

7. An apparatus as defined in claim 6, said first annular channel portion including respective axially spaced sidewalls each provided with one of said margins; and wherein at least one of said sidewalls is at least in part inclined in axial direction of said piston means.

8. An apparatus as defined in claim 7, said one annular sidewall being provided with said second annular margin and being at leastin part inclined axially of said piston means in direction towards said end face of the same.

9. An apparatus as defined in claim 1; and further comprising throttling means for throttling the flow of control fluid through said inlet means.

10. An apparatus as defined in claim 1; further comprising a source of control fluid under pressure connected with said first and second control fluid inlet means; and a valve interposed between said source and said first and second inlet means for establishing and interrupting communication between the former and the latter as required.

Claims

1. An apparatus for regulating the flow of an operating fluid to and from a user device, comprising housing means having a cylinder chamber, and a passage for flow of said operating fluid to and from said user device; valve means in said passage and movable between a normal-closed position and an open position permitting the flow of pressurized operating fluid to said user device; valve control piston means operatively associated with said valve means and movable in said cylinder chamber from a rest position via a first and a subsequent second intermediate position to a control position in which it displaces said valve means to open position for permitting a flow of operating fluid from said user device through said passage; first and second control fluid inlet means each communicating with said chamber for admitting into the latter respective quantities of control fluid under pressure, said first inlet means communicating with said chamber in all of said positions of said piston means; and control means on said piston means operative for establishing communication between said chamber and said second inlet means upon movement of said piston means from said first intermediate position to said second intermediate position, and for terminating such communication upon movement of said piston means from said second intermediate position to said control position.

8. An apparatus as defined in claim 7, said one annular sidewall being provided with said second annular margin and being at least in part inclined axially of said piston means in direction towards said end face of the same.