GB2062186A - Multi-position valve having an actuating device - Google Patents
Multi-position valve having an actuating device Download PDFInfo
- Publication number
- GB2062186A GB2062186A GB8034707A GB8034707A GB2062186A GB 2062186 A GB2062186 A GB 2062186A GB 8034707 A GB8034707 A GB 8034707A GB 8034707 A GB8034707 A GB 8034707A GB 2062186 A GB2062186 A GB 2062186A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- valve spool
- chamber
- spring
- spool
- 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.)
- Granted
Links
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
- F16K11/00—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves
- F16K11/02—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit
- F16K11/06—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements
- F16K11/065—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members
- F16K11/07—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members with cylindrical slides
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Multiple-Way Valves (AREA)
- Magnetically Actuated Valves (AREA)
Abstract
The valve is a three-chamber multi-position valve (10) with e.g. electromagnetic actuation, and incorporates a valve spool (33) whose ends carry cylindrical extensions (36, 37) having conical deflection chamfers (41) which reduce switching impacts and thus spool chatter on the valve spool. In accordance with the invention, slots (27 to 30) interconnecting return chambers (18, 19) and spring chambers (23, 24) form guide portions (31, 32) which guide the extensions (36, 37). This gives small wear and leakage, and thus long durability, even with high pressures and large flow quantities. <IMAGE>
Description
SPECIFICATION
Multi-position valve having an actuating device
The invention relates to a multi-position spool valve with an actuating device e.g. an electromagnet.
German Offenlegungsschrift No. 25 11 991 describes a three-chamber multi-position valve in which only three chambers are defined by spacers which can be over-lapped by the valve spool. In order to avoid impacts on actuation of the valve spool, each end of the valve spool has a cylindrical extension whose end facing the respective load chamber is provided with a conical deflection chamfer. Although this type of multi-position valve can achieve high switching performances, it has the disadvantage that the extensions having deflection chambers project freely into the return chambers. It is precisely the use of high switching performances that reduces the life-time of the valve. The increased wear also increases the flow of leakage oil. This applies particularly when these multi-position valves are designed for various flow-through characteristics by fitting various valve spools.
This type of construction is also not so well suited for use in multi-position valves having different nominal sizes. A further disadvantage resides in the fact that the extension for the spring abutment plate, abutting against a shoulder fixed relative to the housing, of a restoring device projects freely into the return chamber and results in an external diameter which is considerably greater than the external diameter of the valve spool. This results in a relatively large sealing surface which is subjected to the pressure and which has to be sealed by a cover or by a component of the magnet. The fastening elements have to be of correspondingly large dimension in conformity with the large forces which occur, this not being conductive to a compact construction of the multi-position valve.
Furthermore, USA Patent Specification
No. 3,324,890 describes a three-chamber multiposition spool valve in which, for the purpose of avoiding actuating impacts, the valve spool of the multi-position valve cooperates with damping pistons which are disposed in sleeves fixed relative to the housing. A disadvantage of this solution is that it requires a number of additional components, some of which have to be machined, and which can thus only be realised at considerable expense.
Furthermore, German Offenlegungsschrift
No. 2,129,183 describes a magnetically actuable three-chamber multi-position spool valve. In this instance, for the purpose of avoiding actuating impacts, the armature of an actuating magnet is disposed in a chamber filled with pressure medium and is provided with throttling passages.
As well as resulting in a magnet of expensive construction, this arrangement also cannot reduce actuating impacts to a satisfactory extent.
Furthermore, here also, the diameter to be sealed by the magnet or a cover is relatively large, thus leading to fastening elements of correspondingly large dimensions.
There is provided by the present invention a multi-position valve having an actuating device and a valve spool which is disposed in a bore in a housing and which controls communication between an inlet chamber and two load chambers and respective adjacent return chambers which are interconnected by way of a transverse passage and are connected to a return passage, and in which multi-position valve the three central chambers are defined by sealing ribs which cooperate with the valve spool, so that there is formed on the valve spool at least one effective surface which faces the return chamber and which is uncompensated relative to the pressure in the return chamber, which multi-position valve has at least one actuating rod which passes through a return chamber and which establishes an operative connection between the valve spool and the actuating device, and at least one piston-like extension which is located in the region of the return chamber and which is rigidly connected to the valve spool and whose side facing the load chamber is provided with a deflection chamfer to reduce switching impacts, and a restoring device which comprises a spring abutment plate and a spring and which abuts against the extension, wherein the extension is guided in guides which are secured relative to the housing and against which the spring abutment plate of the restoring device abuts.
In contrast to the known valves, the multiposition valve in accordance with the invention has the advantage that its durability is increased to a considerable extent without decreasing the limits of the switching performance. The leakage oil can also be correspondingly minimised by reducing the wear in the multi-position valve.
Since the valve spool only has solid cylindrical piston portions, it can be ground in a centreless manner and can thus be manufactured inexpensively. The spacers are manufacturable in a relatively simple manner without additional expense when casting the housing. Furthermore, a considerable advantage resides in the fact that the diameter to be sealed in the housing is considerably reduced by supporting the springabutment plate on shoulders in spool bore enlargements. The fastening elements for the magnet of a magnetic actuator or the cover can be of correspondingly small construction, this being advantageous with respect to the compact construction of the valve. Thus, the blowing-off of the cover or the magnet from the housing by the hydraulic pressure, or leaks at this location, are more readily avoided, thus also increasing the durability of the multi-position valve.By virtue of the multi-position valve in accordance with the invention, the advantages of the three-chamber construction can be substantially combined with those of a five-chamber construction. High switching performances and great durability can be obtained in valves having differing flowthrough characteristics and rated sizes, such as was hitherto impossible.
Further measures render it possible further to improve the durability of the multi-position valve as well as providing it with a compact and simple construction.
An embodiment of the invention is illustrated in the accompanying drawing, in which: - Figure 1 is a longitudinal section through a multi-position valve, and
Figure 2 is a cross section taken on the line I-I of Figure 1.
Figure 1 shows a multi-position spool valve 10 whose housing 11 is provided with a continuous bore 12 which accommodates the valve spool 33 and which incorporates a plurality of annular widened portions. A central inlet chamber 13 receives pressure medium from a source of pressure medium by way of an inlet passage 13'.
Load chambers 14 and 15 are disposed one at each end of the inlet chamber 13 and are connected to load ports 16, 17 respectively.
Return chambers 1 8, 1 9 are located outwardly adjacent the load chambers 14 and 1 5 and are inter-connected by way of a transverse passage 21 and to a return passage 22. The return chambers 1 8, 1 9 have a substantially circular cross section in the region of the bore 12 and their upper regions merge into the transverse passage 21, at the same time maintaining a cross section which is as uniform as possible. The valve spool bore 12 is widened at the end faces of the housing 11 to form cylindrical spring chambers 23, 24.
The external diameter of each of the spring chambers 23, 24 is chosen to be larger than the diameter of the valve spool bore 12 only by an amount that will provide a respective step 25, 26 serving as a stop. Each return chamber 18 and 19 is connected to its associated spring chamber 23 or 24 by two slots 27, 28 and 29, 30 respectively.
All the slots 27 to 30 extend in a longitudinal plane determined by the valve spool bore 12.
These slots open in a substantially axial direction towards the spring chambers 23 and 24 respectively. Furthermore, all the slots 27 to 30 are open towards the valve spool bore 12. All the slots 27 to 30 have a considerable width (the transverse dimension as seen in Fig. 2) which, as is further shown in Figure 2, is approximately 1/3 of the diameter of the valve spool bore 12. The dimension of the slots in a plane at right angles thereto is approximately twice the diameter of the valve spool bore 12. The slots 27 and 28 divide the bore 12 into two part-cylindrical guide portions 31 in the region between the spring chamber 23 and the return chamber 1 8. The corresponding guide portions between the return chamber 19 and the spring chamber 24 are designated 32.
The valve spool 33 has two piston-like portions 34, 35 which, when the valve spool is in its illustrated central neutral position, open the communication between the two load chambers 14, 1 5 and the inlet chamber 13 as well as the return chambers 1 8 and 1 9 respectively.Each of the portions 34,35 of the valve spool merges by way of a shank portion into a piston-like extension 36 and 37 respectively against which abuts a respective actuating rod 38, 39. A conical deflection chamfer 41 is formed on each extension 36, 37 at the side thereof facing the load chamber 14 or 1 5. In the housing 11, a total of four sealing ribs 42 are associated with the piston portions 34,35 of the valve spool 33, so that the valve 10 can be considered to be of threechamber construction.Furthermore, the extensions 36, 37 of the valve spool 33 are guided in the region of the guide portions 31, 32. A spring abutment plate 43, 44 abuts against each of the extensions 25, 26 and, together with the respective one of springs 45, 46 disposed in the spring chambers 23, 24 forms part of a doubleacting restoring device 47. Each of the spring chambers 23, 24 is sealed outwardly by a respective one of two electromagnets 48, 49 which, in a manner not further illustrated, are secured to the end faces of the housing 11 by means of screw connections. Each of the actuating rods 38, 39 is connected to an armature of each of the respective electro-magnets 48, 49 in a manner not further illustrated.The length of the guide portions 31,32 is chosen to be sufficiently long to guide the extensions 36, 37 of the valve spool 33 in a satisfactory manner even when the valve spool is in its end positions, and also to enable the deflection chamfers 41 to perform their function satisfactorily. The dimension of the slots 27 to 30 in the longitudinal direction of the valve spool 33 is considerably larger than the sum of the lengths of the guide portions 31 and 32 and the thickness of the respective spring abutment plate abutment, and is sufficiently large to ensure that the pressure prevailing in a return chamber 18 or 1 9 can also build up in an unobstructed manner in the associated spring chamber 23 and 24 respectively.
The mode of operation of the multi-position valve 10 will be explained hereinafter:
When the valve spool 33 is in its neutral position shown in Figure 1, the two load ports 16, 17 are connected to the inlet port 13' and also to the return passage 22.
When the armature of the electro-magnet 48 displaces the valve spool 33 to the right into its end position against the force of the return spring 46 by way of the actuating rod 38, the piston portion 35 shuts off communication between the load chamber 1 5 and the return chamber 19, and the piston portion 34 shuts off communication between the load chamber 14 and the inlet chamber 13. Pressure medium coming from the pump flows into the load chamber 1 5 by way of the inlet chamber 13, whereas the load port 1 6 is relieved to the return passage 22. If the pressure in the second load chamber 1 5 is then relatively high, and the magnet 48 is switched off, the spring 46 in the second spring chamber 24 urges the valve spool 33 from its end position back into its neutral position by way of the spring abutment plate 44.When the piston portion 35 then establishes communication between the second load chamber 15 and the return chamber 19, a dynamic pressure builds up in the return chamber
1 9 as a result of the high pressure in the load chamber 1 5 upon reduction of the pressure peak and also becomes effective in the spring chamber 24 by way of the slots 29, 30. This dynamic pressure acts upon the effective end face of the valve spool 33 in the second spring chamber 24 and seeks to accelerate the valve spool during its switching movement towards the left, since this pressure peak can act upon the oppositely located end face of the spool 33 only in a more or less greatly retarded manner by way of the transverse passage 21 and the return passage 22.However, as a result of the deflection of the return flow emerging from the load chamber 1 5 into the return chamber 1 9 by means of the deflection chamfer 41, the valve spool 33 is subjected to pulsed forces which substantially counter-balance the previously mentioned forces which accelerate the switching movement. During this cut-off operation, the deflection chamfer 41 approaches the right-hand sealing rib 42 to an increasing extent without emerging from the guide portions 32.The return flow entering the return chamber 1 9 can then act upon the deflection chamfer 41 in an undiminished manner in the region of the slots 29, 30. As a result of the largely balanced forces acting upon the valve spool 33, the multiposition valve is actuated in a substantially gentler manner and the switching sounds are considerably reduced. By virtue of the position of Lithe deflection chamfer 41 relative to the flow and to the return chamber 19, and by virtue of its size and its construction, actuation of the multiposition valve can be influenced over the greatest portion of the stroke of the valve spool 33.The vale spool 33 is satisfactorily guided by the extensions 36, 37 in the guide portions 31,32 during these switching operations, so that the valve
10 is subjected to only a small amount of wear even after it has been operating for a long period of time in the vicinity of its switching performance limits. The leakage oil in the valve is thus also minimized. Chatter-free operation of the valve spool 33 is ensured even with relatively high pressures and large flow-through quantities.
Furthermore, as a result of the special
construction of the slots 27 to 30, the spring
abutment plates 43, 44 of the restoring device 47 can be supported on the guide portions 31,32 and not in the housing 11 itself. Thus, the external diameter of the spring chambers 23, 24 need only
be larger than the external diameter of the valve spool 33 by the amount of the extensions 25, 26 serving as stops. Thus, the surface area which is subjected to the hydraulic pressure, and which is to be sealed by the magnet 48, 49 or a cover (not
illustrated) can be kept small. Consequently, the
means for securing the magnet or the cover to the
end face of the housing 11 can be of smaller dimensions, this being advantageous with respect to compact construction of the valve.Moreover, the fastening means can be more readily designed so as to prevent the blowing-off of the magnet or of the cover by hydraulic pressure or to prevent a leak, thus increasing the durability of the valve. By virtue of the solid cylindrical construction of the piston portions 34, 35 and of the extensions 36, 37, the valve spool 33 can be ground in a centreless manner and thus can be manufactured relatively inexpensively. The slots 27 to 30 can be taken into account without any great additional expense when casting the housing 11.
Gentle, chatter-free switching of the valve spool 33 is achieved in a corresponding manner when the armature of the magnet 49 moves the valve spool to the left from its illustrated neutral position into its end position and the valve spool is subsequently urged back into its neutral position by the spring 45. Thus, the proposed solution provides a multi-position valve which renders it possible to obtain high switching performances over a long lifetime. Moreover, it permits of a simple and compact type of construction.
It will be appreciated that modifications are possible without departing from the subject of the invention. Thus, the valve spool can have a positive overlap instead of the negative overlap which is illustrated. The configuration of the deflection chamfer can also be varied within certain limits. The multi-position valve can also be designed for other flow-through configurations by fitting different valve spools. Instead of being used for the illustrated three-position valve, the invention can also be used in a two-position valve which has only one switching position in addition to its initial position. The invention is also not limited to electrically actuated valves, and can also be advantageous in the case of mechanically, pneumatically or hydraulically actuated valves. It will be appreciated that the hydraulic force components must not be fully compensated for, since a certain residual force is frequently desired in order to obtain a high switching performance.
Alternatively, although it is advantageous and a simple matter to form the slots in a longitudinal plane, the guide portions can be formed by, for example, three slots which are disposed radially of the bore for the valve spool. Further modifications are also possible without departing from the scope of the invention.
Claims (8)
1. A multi-position valve having an actuating device and a valve spool which is disposed in a bore in a housing and which controls communication between an inlet chamber and two load chambers adjacent thereto and between the load chambers and respective adjacent return chambers which are interconnected by way of a transverse passage and are connected to a return passage, and in which multi-position valve the three central chambers are defined by sealing ribs which co-operate with the valve spool, so that there is formed on the valve spool at least one effective surface which faces the return chamber and which is uncompensated relative to the pressure in the return chamber, which multi position valve has at least one actuating rod which passes through a return chamber and which establishes an operative connection between the valve spool and the actuating device, and at least one piston-like extension which is located in the region of the return chamber and which is rigidly connected to the valve spool and whose side facing the load chamber is provided with a deflection chamfer to reduce switching impacts, and a restoring device which comprises a spring abutment plate and a spring and which abuts against the extension, wherein the extension is guided in guides which are secured relative to the housing and against which athe spring abutment plate of the restoring device abuts.
2. A multi-position valve as claimed in claim 1, wherein the guides are in the form of portions of the bore for the valve spool.
3. A multi-position valve as claimed in claim 1 or 2, wherein the diameter of the spring chamber accommodating the spring is larger than the diameter of the valve spool bore by the amount of a step on the guides which form a stop for the spring abutment plate.
4. A multi-position valve as claimed in claims 2 and 3, wherein each guide portion is divided by a longitudinal slot, and the slot is larger in the longitudinal direction of the valve spool than the sum of the length of the guide portions and the thickness of the spring abutment plate abutment on the step.
5. A multi-position valve as claimed in claim 4, wherein each guide portion is divided by two diametrically opposed longitudinal slots.
6. A multi-position valve as claimed in either of claims 4 or 5, wherein the transverse passage terminates at each end in a return chamber and a spring return chamber, and each slot is provided so as to open in a substantially axial direction into each return chamber and radially into each spring chamber.
7. A multi-position valve as claimed in claim 5 or 6, wherein the width of each slot is substantially one third of the external diameter of the valve spool and its dimension in a radial direction is approximately twice the external diameter of the valve spool.
8. A multi-position spool valve substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19792943714 DE2943714A1 (en) | 1979-10-30 | 1979-10-30 | DIRECTIONAL VALVE WITH ELECTROMAGNETIC ACTUATOR |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2062186A true GB2062186A (en) | 1981-05-20 |
| GB2062186B GB2062186B (en) | 1983-11-23 |
Family
ID=6084680
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8034707A Expired GB2062186B (en) | 1979-10-30 | 1980-10-29 | Multi-position valve having an actuating device |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5673271A (en) |
| DE (1) | DE2943714A1 (en) |
| FR (1) | FR2468812A1 (en) |
| GB (1) | GB2062186B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4715407A (en) * | 1986-10-14 | 1987-12-29 | Clevite Industries Inc. | Spool valve assembly |
| WO2002086363A1 (en) * | 2001-04-20 | 2002-10-31 | Zf Friedrichshafen Ag | Regulator valve |
| CN102563129A (en) * | 2012-01-16 | 2012-07-11 | 杭州发达齿轮箱集团有限公司 | Electric-hydraulic reversing valve with power loss position limiting function for marine gearboxes |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4566490A (en) * | 1981-11-12 | 1986-01-28 | Mac Valves, Inc. | Direct solenoid operated valve with minimal tolerance accumulation |
| DE3708110A1 (en) * | 1987-03-13 | 1988-09-22 | Bosch Gmbh Robert | Electromagnetically actuated directional valve |
| DE3915223A1 (en) * | 1989-05-10 | 1990-11-15 | Bosch Gmbh Robert | ELECTROMAGNETICALLY ACTUATED DIRECTION VALVE |
| DE19655090C2 (en) * | 1996-03-01 | 2000-04-27 | Bosch Gmbh Robert | Electromagnetically operated directional valve |
| US8671988B2 (en) * | 2008-09-02 | 2014-03-18 | Emerson Process Management Regulator Technologies, Inc. | Fluid flow control members for use with valves |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3324890A (en) * | 1965-06-09 | 1967-06-13 | Continental Machines | Solenoid valve having controlled retardation of spool motion |
| DE2129183A1 (en) * | 1970-06-13 | 1971-12-23 | Atos Apparecchiature Oleodinam | Liquid valve with direct electromagnetic control and reversing to adjustable speeds |
| DE2511991C2 (en) * | 1975-03-19 | 1984-06-28 | Robert Bosch Gmbh, 7000 Stuttgart | Directional valve with electromagnetic actuation device |
| JPS5720921Y2 (en) * | 1976-04-02 | 1982-05-06 | ||
| FR2420066A1 (en) * | 1978-03-17 | 1979-10-12 | Renault Tech Nouvelles | Electrohydraulic fluid distributor - has slide with bosses forming connecting chambers so that outlet flow fluid traverses and cools magnets |
-
1979
- 1979-10-30 DE DE19792943714 patent/DE2943714A1/en active Granted
-
1980
- 1980-10-29 GB GB8034707A patent/GB2062186B/en not_active Expired
- 1980-10-30 FR FR8023218A patent/FR2468812A1/en active Granted
- 1980-10-30 JP JP15153080A patent/JPS5673271A/en active Granted
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4715407A (en) * | 1986-10-14 | 1987-12-29 | Clevite Industries Inc. | Spool valve assembly |
| WO2002086363A1 (en) * | 2001-04-20 | 2002-10-31 | Zf Friedrichshafen Ag | Regulator valve |
| US7021605B2 (en) | 2001-04-20 | 2006-04-04 | Zf Friedrichshafen Ag | Regulator valve |
| CN102563129A (en) * | 2012-01-16 | 2012-07-11 | 杭州发达齿轮箱集团有限公司 | Electric-hydraulic reversing valve with power loss position limiting function for marine gearboxes |
| CN102563129B (en) * | 2012-01-16 | 2015-01-07 | 杭州发达齿轮箱集团有限公司 | Electric-hydraulic reversing valve with power loss position limiting function for marine gearboxes |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2062186B (en) | 1983-11-23 |
| FR2468812B1 (en) | 1984-04-27 |
| JPS5673271A (en) | 1981-06-17 |
| DE2943714C2 (en) | 1988-12-01 |
| DE2943714A1 (en) | 1981-05-14 |
| FR2468812A1 (en) | 1981-05-08 |
| JPH0214587B2 (en) | 1990-04-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20001028 |