GB2079411A - A hydraulic control valve and a hydraulic control piston - Google Patents

A hydraulic control valve and a hydraulic control piston Download PDF

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Publication number
GB2079411A
GB2079411A GB8121043A GB8121043A GB2079411A GB 2079411 A GB2079411 A GB 2079411A GB 8121043 A GB8121043 A GB 8121043A GB 8121043 A GB8121043 A GB 8121043A GB 2079411 A GB2079411 A GB 2079411A
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GB
United Kingdom
Prior art keywords
piston
control
groove
recesses
cylindrical bore
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8121043A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Oerlikon Barmag AG
Original Assignee
Barmag Barmer Maschinenfabrik AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Barmag Barmer Maschinenfabrik AG filed Critical Barmag Barmer Maschinenfabrik AG
Publication of GB2079411A publication Critical patent/GB2079411A/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K47/00—Means in valves for absorbing fluid energy
    • F16K47/04—Means in valves for absorbing fluid energy for decreasing pressure or noise level, the throttle being incorporated in the closure member

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Driven Valves (AREA)

Abstract

The present invention relates to a hydraulic control piston and a hydraulic valve, the piston being movable in a cylindrical bore of the valve. The piston may be used to control the pressure and/or the quantity of an oil flow. The control piston 14 has an annular or partly annular groove (9) cut into the face (8) thereof. Slit-shaped openings (11) extend radially from the piston skirt surface (4) to the groove (9). The openings (11) may extend axially from the face (8) of the piston (14) to the base (12) of the groove (9). <IMAGE>

Description

SPECIFICATION A hydraulic control valve and a hydraulic control piston This invention relates to a hydraulic control valve and a hydraulic control piston of the hydraulic valve which is movable in a cylindrical bore and is used to control the pressure and/or the quantity of an oil flow. The control piston forms a control edge with the penetration edge between its face and its circumferential surface and notches, recesses or the like which are worked therein. In turn, this control edge forms a control cross section with a control edge located in the cylindrical bore, and the oil flow may be controlled by adjusting the control cross section.
Control pistons of this type are known, for exam ple, from German Patent No. 893,749.
The recesses are to suppress the axial reaction forces exerted on the piston by the oil flow. However, these recesses do not perform this function adequately.
Such axial forces are substantially reduced by the solution specified in claim 1.
According to the invention there is provided a hydraulic control piston which is axially movable in a cylindrical bore, comprising recesses of a restricted width and restricted axial extent on its circumference, wherein an annular or partly-annular groove is formed in the face of the piston and, the recesses extend in a radial direction up to the said groove.
The invention also provides a hydraulic control valve comprising a valve housing with a cylindrical bore and a control piston which is axially moveable within the said bore, wherein the control piston comprises recesses of a restricted width and restricted axial extent or its circumference and, an annular or partly annular groove formed in its face in the region of the control edge of the bore, the recesses extending in a radial direction up to the said groove.
The depth of this groove, i.e. the axial extent of the groove, approximately corresponds to the axial extent of the recess, but it should be added that it is possible for the annular groove to be of a greater axial extent. The recesses are designed such that they penetrate the external walls of the annular groove as holes or notches, i.e. they penetrate the ridge between the annular groove and the external circumference of the piston. Therefore, the external wall of the annular groove is castellated with respect to the base of the groove.
It is pointed out that forfunctional purposes the annular groove only has to extend over the circumferential region, over which the control edge in the cylindrical bore also extends. Likewise, the openings in the outer wall also only need to be provided in the region of the control edge of the cylindrical bore.
An embodiment of the invention will be described in the following with reference to Figures 1 and 2 of the drawings, wherein: Figure 1 is a schematic section through a hydraulic valve cylinder with a choke piston; and Fiqure 2 is a perspective partial view of the choke piston.
A cylindrical bore 1 of the valve housing has an inlet channel 2 and an outlet channel 3, a reversal in the through-flow direction also being possible. A control piston 14 is axially movable in the cylindrical bore 1. This piston is connected to a piston rod 5 and it is moved axially by the rod in a manner which is not shown, so that a definite control cross section may be adjusted by a control edge 6 of the cylindrical bore 1 and by control edges 15 of the piston 14.
In the Example which is illustrated, the piston 14 is used to control an oil flow from channel 2 to channel 3 so that the pressure P1 prevails in the cylinder bore upstream of the piston and the lower pressure P2 prevails in the outlet channel. The controllable flow cross section is formed on one hand by the control edge 6 in the cylindrical bore 1 and on the other hand by the control edges 15 on the piston 14. In order to form the control edge, an annular groove 9 is formed in the face 8 of the piston and this is effected in the embodiment illustrated by having a pot-shaped piston which rests on the piston rod 5. The piston skirt surface 4 is provided with openings 11 which extend between the annular groove 9 and the piston skirt surface 4. The penetration of the openings 11 through the piston skirt forms the control edges 15 of the piston.In an axial direction, the openings 11 extend from the face 8 to the base 12 of the groove 9.
The face 8 has circumferential edges 10. Where the annular groove 9 is of a corresponding axial depth, the cross-section of the openings may also be rectangular, triangular, in the form of a circle segment or of some other form. It is not necessary in terms of the invention forthe openings to extend axially up to the base 12 of the groove 9. The static pressure on both sides of the piston 14 is compensated via a pressure compensation channel 13.
The invention ensures that the oil flow from the cylindrical bore into the annular channel 7 or vice versa substantially has only one radial direction, so that the stationary portion of the flow force is reduced in the axial direction. In this design of the piston, its control edges are formed by the edges of the openings denoted with reference numeral 11 in Figure 2.
1. A hydraulic control piston which is axially movable in a cylindrical bore, comprising recesses of a restricted width and restricted axial extent on its circumference, wherein an annular or partly annular groove is formed in the face of the piston and, the recesses extend in a radial direction up to the said groove.
2. A hydraulic control piston according to claim 1, wherein the recesses are designed as slit-shaped openings in the external walls of the groove, and they extend in an axial direction from the face of the piston up to the base of the groove.
3. A hydraulic control piston substantially as herein described with reference to the accompanying drawings.
4. A hydraulic control valve comprising a valve
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A hydraulic control valve and a hydraulic control piston This invention relates to a hydraulic control valve and a hydraulic control piston of the hydraulic valve which is movable in a cylindrical bore and is used to control the pressure and/or the quantity of an oil flow. The control piston forms a control edge with the penetration edge between its face and its circumferential surface and notches, recesses or the like which are worked therein. In turn, this control edge forms a control cross section with a control edge located in the cylindrical bore, and the oil flow may be controlled by adjusting the control cross section. Control pistons of this type are known, for exam ple, from German Patent No. 893,749. The recesses are to suppress the axial reaction forces exerted on the piston by the oil flow. However, these recesses do not perform this function adequately. Such axial forces are substantially reduced by the solution specified in claim 1. According to the invention there is provided a hydraulic control piston which is axially movable in a cylindrical bore, comprising recesses of a restricted width and restricted axial extent on its circumference, wherein an annular or partly-annular groove is formed in the face of the piston and, the recesses extend in a radial direction up to the said groove. The invention also provides a hydraulic control valve comprising a valve housing with a cylindrical bore and a control piston which is axially moveable within the said bore, wherein the control piston comprises recesses of a restricted width and restricted axial extent or its circumference and, an annular or partly annular groove formed in its face in the region of the control edge of the bore, the recesses extending in a radial direction up to the said groove. The depth of this groove, i.e. the axial extent of the groove, approximately corresponds to the axial extent of the recess, but it should be added that it is possible for the annular groove to be of a greater axial extent. The recesses are designed such that they penetrate the external walls of the annular groove as holes or notches, i.e. they penetrate the ridge between the annular groove and the external circumference of the piston. Therefore, the external wall of the annular groove is castellated with respect to the base of the groove. It is pointed out that forfunctional purposes the annular groove only has to extend over the circumferential region, over which the control edge in the cylindrical bore also extends. Likewise, the openings in the outer wall also only need to be provided in the region of the control edge of the cylindrical bore. An embodiment of the invention will be described in the following with reference to Figures 1 and 2 of the drawings, wherein: Figure 1 is a schematic section through a hydraulic valve cylinder with a choke piston; and Fiqure 2 is a perspective partial view of the choke piston. A cylindrical bore 1 of the valve housing has an inlet channel 2 and an outlet channel 3, a reversal in the through-flow direction also being possible. A control piston 14 is axially movable in the cylindrical bore 1. This piston is connected to a piston rod 5 and it is moved axially by the rod in a manner which is not shown, so that a definite control cross section may be adjusted by a control edge 6 of the cylindrical bore 1 and by control edges 15 of the piston 14. In the Example which is illustrated, the piston 14 is used to control an oil flow from channel 2 to channel 3 so that the pressure P1 prevails in the cylinder bore upstream of the piston and the lower pressure P2 prevails in the outlet channel. The controllable flow cross section is formed on one hand by the control edge 6 in the cylindrical bore 1 and on the other hand by the control edges 15 on the piston 14. In order to form the control edge, an annular groove 9 is formed in the face 8 of the piston and this is effected in the embodiment illustrated by having a pot-shaped piston which rests on the piston rod 5. The piston skirt surface 4 is provided with openings 11 which extend between the annular groove 9 and the piston skirt surface 4. The penetration of the openings 11 through the piston skirt forms the control edges 15 of the piston.In an axial direction, the openings 11 extend from the face 8 to the base 12 of the groove 9. The face 8 has circumferential edges 10. Where the annular groove 9 is of a corresponding axial depth, the cross-section of the openings may also be rectangular, triangular, in the form of a circle segment or of some other form. It is not necessary in terms of the invention forthe openings to extend axially up to the base 12 of the groove 9. The static pressure on both sides of the piston 14 is compensated via a pressure compensation channel 13. The invention ensures that the oil flow from the cylindrical bore into the annular channel 7 or vice versa substantially has only one radial direction, so that the stationary portion of the flow force is reduced in the axial direction. In this design of the piston, its control edges are formed by the edges of the openings denoted with reference numeral 11 in Figure 2. CLAIMS
1. A hydraulic control piston which is axially movable in a cylindrical bore, comprising recesses of a restricted width and restricted axial extent on its circumference, wherein an annular or partly annular groove is formed in the face of the piston and, the recesses extend in a radial direction up to the said groove.
2. A hydraulic control piston according to claim 1, wherein the recesses are designed as slit-shaped openings in the external walls of the groove, and they extend in an axial direction from the face of the piston up to the base of the groove.
3. A hydraulic control piston substantially as herein described with reference to the accompanying drawings.
4. A hydraulic control valve comprising a valve housing with a cylindrical bore and a control piston which is axially movable within the said bore, wherein the control piston comprises recesses of a restricted width and restricted axial extent on its circumference and an annular or partly annular groove formed in its face in the region of the control edge of the bore, the recesses extending in a radial direction up to the said groove.
5. A hydraulic control valve according to claim 4, wherein the recesses are designed as slit-shaped openings in the extend walls of the groove, and they extend in an axial direction from the face of the piston up to the base of the groove.
6. A hydraulic control valve substantially as herein described with reference to the accompanying drawings.
GB8121043A 1980-07-09 1981-07-08 A hydraulic control valve and a hydraulic control piston Withdrawn GB2079411A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3025923 1980-07-09
DE8033339 1980-12-16

Publications (1)

Publication Number Publication Date
GB2079411A true GB2079411A (en) 1982-01-20

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB8121043A Withdrawn GB2079411A (en) 1980-07-09 1981-07-08 A hydraulic control valve and a hydraulic control piston

Country Status (1)

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GB (1) GB2079411A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012061002A1 (en) * 2010-11-01 2012-05-10 Emerson Process Management Regulator Technologies, Inc. Flow directing apparatus for use with fluid regulators
US9004452B2 (en) 2010-11-01 2015-04-14 Emerson Process Management Regulator Technologies, Inc. Valve bodies having integral boost reducing capability

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012061002A1 (en) * 2010-11-01 2012-05-10 Emerson Process Management Regulator Technologies, Inc. Flow directing apparatus for use with fluid regulators
JP2013546069A (en) * 2010-11-01 2013-12-26 エマーソン プロセス マネージメント レギュレーター テクノロジーズ インコーポレイテッド Flow directing device for use with fluid regulators
US9004452B2 (en) 2010-11-01 2015-04-14 Emerson Process Management Regulator Technologies, Inc. Valve bodies having integral boost reducing capability
RU2581515C2 (en) * 2010-11-01 2016-04-20 Эмерсон Процесс Менеджмент Регьюлэйтор Текнолоджиз, Инк. Device for flow directing for use with fluid regulators

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)