WO2016135275A1

WO2016135275A1 - Spool valve

Info

Publication number: WO2016135275A1
Application number: PCT/EP2016/054045
Authority: WO
Inventors: Brian Kane; Rudolf Schaeffer; Richard Bauer; Edwinus HEEMSKERK
Original assignee: Robert Bosch Gmbh
Priority date: 2015-02-26
Filing date: 2016-02-26
Publication date: 2016-09-01
Also published as: DE102015203448A1

Abstract

Disclosed is a continuously adjustable spool valve comprising an inner bushing (2), which serves as the valve spool, and comprising an outer bushing (4) fixed to the housing, which is surrounded by two annular spaces (10, 12). In order to adjust the flow cross-section between the two annular spaces, a plurality of slots (18) are provided in the inner bushing and in the bushing fixed to the housing, which slots extend in the circumferential direction of the bushings and are axially spaced with respect to each other. When the inner bushing (2) is displaced, the slots can be simultaneously covered and the connection is hence pushed shut or enlarged in the overlap thereof and the connection is thus opened.

Description

spool valve

description

The invention relates to a sliding valve designed as a quick-acting valve according to the preamble of patent claim 1.

Sliding valves are known from the prior art, in which a valve slide, which is received concentrically in a valve bore, as it moves along a longitudinal axis of the slide valve, opens or heads one or more different pressure medium connections. In this case, per pair of pressure medium connection, a pair of circular peripheral control edges is provided, whose distance from one another define a flow cross-section. By a movement of the valve slide in the closing direction, the collars, on which the control edges are formed, can be brought into coincidence, resulting in a closure of the affected pressure medium connection.

Furthermore, slide valves are known from the prior art, in which a pressure medium connection can be opened or closed together via a plurality of pairs of control edges.

The publications US 80,509 and US 3,794,063 show such slide valves, in which for the one to be controlled pressure medium connection three axially spaced or in the direction of displacement spaced slots are provided, via which the affected pressure medium connection can be simultaneously opened or closed. In this case, limited slits or slots are formed on the valve spool in their length. Both documents show stationary bushings which comprise the respective valve slide, and in which slots are also provided. The documents US 90,427 and US 2,855,025 show in principle similar slide valves, in which the respective valve slide has several circumferential slots. This results in that the valve spool is composed of individual rings, which are held together by inner ribs. In US Pat. No. 2,854,025, the bushing which includes the valve spool is likewise configured in a similar manner. More specifically, the bush also has a plurality of circumferential slots, resulting in rings of the bush, which are also secured to each other via ribs. In all four publications mentioned a pressure medium connection between a first annular space surrounding the slots and a second end pressure chamber is controlled via several slots, so that along the longitudinal axis of the spool valve results in a juxtaposition of an actuator, the valve spool with the socket and the frontal pressure chamber. As a result, each slide valve of the prior art has a considerable length.

In contrast, the invention is based on the object to provide a slide valve, in which a pressure medium connection is controllable via a plurality of parallel control edges, and whose length is shortened, so that there is a more compact design of the slide valve.

This object is achieved by a slide valve having the features of patent claim 1. The claimed continuously adjustable slide valve serves as a quick-acting valve and has a housing on which a first connection and a second connection are formed. In the housing, a socket is inserted, in which a valve slide is guided displaceably. The valve spool has a sleeve-shaped main section. Along the circumference of the main portion, a plurality of slots extend, and along the circumference of the sleeve extending a plurality of slots, whereby parallel control edges of the spool valve are formed. According to the invention, a first annulus connected to the first port and axially adjacent thereto a second annulus connected to the second port are disposed in the housing, both of which surround the bushing. The first annulus is connectable via the slots with an interior of the valve spool and the sleeve, and the interior is connected via passage openings of the sleeve with the second annulus. For a slide valve is created, which releases a very large opening cross-section with a very short stroke of the valve spool. The control edges are geometrically combined and results in a high power density. The slide valve according to the invention can be used, for example, in digital hydraulics, in digitally adjustable piston machines (Digital Variable Piston Machine) and in multi-surface cylinders in mobile and industrial hydraulics. Due to the sleeve-like shape of the main portion of the valve spool and because of the slots, the mass of the valve spool is low, which can increase the speed of its displacement and thus the adjustment of the spool valve. The slide valve according to the invention can for large volume flows (eg

10001 / min). The arrangement of the two annular spaces, the two associated connections can be arranged laterally, and the length of the slide valve along the direction of displacement of the valve spool is minimized. Because of the simple housing, hydraulic accumulators can be located very close to the control edges of the slots. This results in a reduction of the hydraulic inductance. In a particularly preferred embodiment pairs of valve slide side slots and socket-side slots are formed. To reduce the flow resistance and flow forces when the slide valve is open, it is preferred if the valve slide-side slots and the sleeve-side slots at least in pairs in the direction of the valve spool have the same width and are approximately congruent with each other when the valve is open.

If the valve-slide-side slots are circular-arc-shaped and are arranged offset from one another on the valve slide (viewed in the circumferential direction), a stable valve slide is produced which requires no ribs and thus has a minimum mass. In particular, the slots in their axial sequence, for example, alternately offset in the circumferential direction to each other. When the valve spool-side slots are full, rings of the main portion of the valve spool are created between them. This maximizes the flow rate. A rotational position of the valve spool is arbitrary with full-circumferential slots. The rings can be connected to one another via ribs preferably extending along the displacement direction.

Further advantageous embodiments of the invention are described in the dependent claims. When the socket-side slots (viewed in cross-section of the socket) are circular arc-shaped and offset relative to each other at the periphery of the socket are arranged, resulting in a stable socket that does not require ribs. In particular, the slots in their axial sequence, for example, alternately (viewed in the circumferential direction) to each other offset. In the circular arc slots then a rotation for the valve spool or its main section may be necessary.

In a preferred embodiment, the valve slide side slots and the socket side slots are the same length. They can have an angular extent of 60 or 90 degrees at the circumference of the respective component.

It is particularly particularly advantageous if all the valve-slide-side slots and all socket-side slots can be exactly matched in pairs. Then the control edge geometry in the open state is free of flow.

In a preferred embodiment of the sleeve whose slots are formed only on its inner circumference, while recesses are formed on the outer circumference of the bush, which are connected to the slots. The extension of the recesses in the circumferential direction is smaller than that of the slots. The extent of the recesses in the direction of displacement is greater than that of the slots. The recesses can be circular cylindrical. Adjacent to a first end face of the bush, an actuator can be arranged, which is operatively connected, for example via a plunger with a rod of the valve spool. For this purpose, the plunger bear against the rod end face. In the region of a second end face of the bush, a spring can be arranged, which counteracts the actuator. The spring is preferably arranged to save space in the interior of the socket. The rod is preferably longer than the valve spool or as its main portion. To reduce the Klemmneigung the main portion of the valve spool is preferably attached to the rod with radial play.

The overall cross section of the recesses and the overall cross section of the bushing side slots and the overall cross section of the valve spool side slots and the opening between the main section and the rod and the total cross section of the through holes of the bushing should be the same size. Thus, the flow is optimized especially in the maximum open slide valve.

At one end portion of the main portion of the valve spool, which is disposed adjacent to the first end face of the sleeve, a connecting disc may be provided, via which the valve spool is connected to the rod. Then, the actuating force of the actuator or the spring can be transmitted via the rod and the connecting disk to the main portion of the valve spool.

The connecting disk can form two mutually adjacent chambers in the interior of the socket. According to a first variant, the connection disk can have at least one through-hole. This allows an overflow of the pressure medium between the two chambers. According to a second variant, the connection disc is closed. Further, when the end portion of the main portion is sealed from the first chamber, the first chamber may be permanently low pressure (tank pressure).

In a particularly preferred embodiment of the valve spool is pressure balanced. Then, the sliding valve according to the invention can be controlled and controlled without having to overcome hydrostatic pressure forces. According to the first variant can on both sides of the valve spool and its connection disc working pressure (for example in an open position high pressure) prevail. According to the second variant, low pressure (tank pressure) can prevail on the closed connecting disk and on the sealing piston in each case on the outside. In both variants, a first seal is preferably arranged in the region of the first annular space or in the region of the first end side of the bush, while a second seal is arranged in the region of the second annular space or in the region of the second end side of the bushing. The pressure balance is space-saving and can be achieved with identical parts if the first seal is arranged on a first closure which is inserted into the first end side of the socket, while the second seal is arranged on a second closure which is inserted into the second end side of the socket is. Both seals seal the interior of the socket. It is particularly space-saving if both closures are completely inserted into the socket.

The rod can penetrate the first closure, whereby the spring is supported on the second closure, the rod can also penetrate the second closure for support and optimum guidance.

The pressure balance can also be achieved differently if the first seal is arranged on the end section of the main section of the valve slide, and if the second seal is arranged on a sealing piston of the valve slide. This may be integrally or via the rod attached to the valve spool. This is a two-piece valve spool given. The spring can engage the sealing piston.

In the second end face of the sleeve and a sleeve-shaped insert element can be used, on which the spring is supported. Particularly space- It is saving when the insert element is completely inserted into the socket. In the region of the second end face, a tank connection can be provided. The tank pressure can be separated from the interior of the socket via the sealing piston. The tank connection can be connected via the insert element to the tank pressure side of the sealing piston.

Several embodiments of the slide valve according to the invention are shown in the drawings. With reference to the figures of these drawings, the invention will now be explained in more detail.

Show it

1 shows a longitudinal section of an inventive slide valve according to a first embodiment,

FIG. 2 shows a perspective view of a further longitudinal section of the slide valve from FIG. 1,

3 shows a perspective view of a valve slide of a second embodiment of the slide valve according to the invention,

Figure 4 shows a longitudinal section of an inventive slide valve according to a third embodiment and

5 shows a perspective view of a further longitudinal section of the slide valve of Figure 4. Figures 1 and 2 show a first embodiment of the slide valve according to the invention in sectional views along a central displacement or longitudinal axis. 1 Concentric to this, a cup-like valve slide 2 and on the outer circumference of a bushing 4 are arranged, wherein the socket 4 is held via a cover 6 in a substantially cylindrical recess of a housing 8. In the vicinity of the cover 6, a first annular space 10 is arranged, and axially adjacent to the first th annular space 10, a second annular space 12 is arranged. Both annular spaces 10, 12 are formed on the one hand as radial recesses on the outer circumference of the bushing 4 and on the other hand as a radial recess on the inner circumference of the cylindrical recess 8 of the housing. About seals 14, the two annular spaces 10, 12 against each other and sealed against the end faces of the bushing 4. The first annular space 10 is connected to an input terminal P of the housing 8, while the second

Annulus 12 is connected to an output terminal A of the housing 8. The two ports P, A are arranged radially longitudinal axis 1, so that no pressure space and no connection are necessary on the side facing away from the cover 6 end face of the bushing 4, whereby the overall length of the slide valve is minimized. The two terminals P, A are provided in the first embodiment according to Figures 1 and 2 on opposite sides of the housing 8.

In a first region of the bush 4, which is encompassed by the first annular space 10, a plurality of two-part passages for pressure medium are provided. More precisely, a plurality of circular cylindrical recesses 16 are provided on the outer circumference of the bushing 4, while a corresponding number of slots 18 are provided on the inner periphery of the bushing 4, which have the shape of a circular arc due to the circular cylindrical inner shell of the bushing 4. In this case, an equal number of corresponding slots 20 are provided on a sleeve-like main section 3 of the valve slide 2, which are in the open position of the slide valve according to the invention shown in FIGS. 1 and 2 in coincidence with the sleeve-side slots 18. The slots 18, 20 of both components 4, are the same number, the same length and the same width. There are four groups of slots 18, 20 each provided, each having three slots 18, 20. The four groups are evenly spaced axially distributed on the respective component 2, 3. The three slots 18, 20 of each group are uniformly distributed on the circumference of the component 2, 3. Here, the angular position of the slots 18, 20 of the first group and the slots 18, 20 of the third group, while the angular position of the slots 18, 20 of the second group and the slots 18, 20 of the fourth group offset and also equal. This results in a cross-group viewing of the slits 18, 20 in the axial direction an alternating offset.

In the illustrated open position of the spool valve pressure medium from port P via the first annulus 10, via the recesses 16, via the socket-side slots 18 and the valve spool side slots 20 into the interior of the main portion 3 of the valve spool 2 and from there flow axially in the direction of From there, the pressure medium flows through evenly distributed on the circumference of the socket 4 openings 22 in the second annulus 12 and from there to the output terminal A.

The displacement of the valve spool 2 in the open position shown in Figures 1 and 2 is carried out by an electromagnetic actuator 24 along the longitudinal axis 1, the coil 26 when current is applied to contacts, of which in Figures 1 and 2 only one contact 28 is shown , an armature 30 has moved a plunger 32 in the direction of the valve slide 2. In this case, the plunger 32 has moved therefrom a rod 34 in the direction of the actuator 24. From the rod 34 has a snap ring 33 has a connecting pulley 36 is taken over a snap ring 33, which integral with the

Main section 3 of the valve spool 2 is formed and so transmits the movement of the rod 34 on the valve spool side slots 20.

Against the force of the actuator 24, the force of a spring 38 acts in the closing direction, which is supported on a closure 42 and biases the valve spool 2 in the closing direction via a spacer 39 pushed onto the rod 34, which is supported on the connecting disk 36. The rod 34 and the socket 4 are about the same length and more than twice as long like the valve spool 2. The rod 34 is guided sealingly on the one hand by a first closure 40 and on the other hand by the second closure 42. At their outer peripheries, the closures 40, 42 have seals over which they seal the interior of the bush 4 to the outside. Thus, on the one hand between the first closure 40 and the connecting disc 36 and on the other hand between the second closure 42 and the connecting disc 36 two Rooms which are connected to each other via passage recesses 44 of the connecting disk 36 so that the pressure medium can flow over between the two spaces when the valve slide 2 is moved. Thus, the valve spool 2 is also pressure balanced.

The electromagnetic actuator 24 is secured by screws on the cover 6. This results in the following sequence of components along the longitudinal axis 1 of the first exemplary embodiment of the slide valve according to the invention: actuator 24, cover 6, first closure 40, first space, connection disc 36, second space with interior of the main section 3 and spring 38, second closure 42. FIG 3 shows a valve slide 102 of a second exemplary embodiment of a slide valve according to the invention in a perspective illustration. In this case, four slots 120 are fully formed, so that a total of five rings 146 result, which form the main portion 103 of the valve spool 102. The rings 146 are attached to each other via four ribs 148, which are formed like a surface and extend radially at an angle of 90 ° to each other. Each rib 148 extends from the longitudinal axis 1 of the spool valve of the present invention to the inner periphery of all of the rings 146. The spool 102 of the second embodiment maximizes by maximizing the valve spool 120 slots Volume flow through them. Furthermore, the valve spool 102 of the second embodiment allows an axial overflow of the pressure medium during its displacement. Deviating from the second exemplary embodiment according to FIG. 3, a tubular section can be provided concentrically in the interior of the valve slide 102, which extends along the longitudinal axis. The rod 34 of the first exemplary embodiment according to FIGS. 1 and 2 can be passed through this section (not shown). so that the valve slide 102 can be fixed with a comparison with the first embodiment according to Figures 1 and 2 shortened spacer 39 on the rod 34.

Figures 4 and 5 show a third embodiment of the inventive slide valve in a sectional view along the longitudinal axis 1, wherein in Figure 4, all components are shown in section, while in the perspective view of Figure 5, some middle components are not cut. Deviating from the first exemplary embodiment according to FIGS. 1 and 2, the two ports P, A are arranged on the same outer side of the housing 108, while a tank port T is provided on an opposite outer side. This is connected via an angled tank channel 250 and a concentric recess of a sleeve-shaped insert element 252 with a arranged in the second region of the socket 4 spring chamber in which the spring 38 is arranged. The spring 38 is supported on the insert element 252 and acts on a sealing piston 254 of the valve spool 202 with a force in the closing direction. More specifically, the valve spool 202 is formed in two parts. Its rod 234 is formed integrally with the sealing piston 254 and integrally with a connecting disc 236. On the outer periphery of the connecting disc 236, the main portion 3 of the valve spool 202 is fixed. A space formed between the actuator 24 and the connecting disk 236 always has low pressure in the third embodiment. Accordingly, the connecting disc 236 has no recesses and is connected by laser welding or friction welding tightly connected to the main section 3. Seals are provided on the outer circumference of the main section 3 in the region of the connecting disk 236 and on the outer circumference of the sealing piston 254. Thus, in the interior of the main portion 3 and the sleeve 4 between the connecting disc 236 and the Thief piston 254 a sealed to the end faces of the bushing 4 pressure chamber is formed. This is permanently in the manner described with reference to Figures 1 and 2 with the output terminal A and depending on the position of the valve spool 202 with the input port P in fluid communication.

The sleeve 4 with the socket-side slots 18, the annular spaces 10, 12 and the valve slide side slots 20 correspond to those of the first embodiment shown in Figures 1 and 2. The actuator 24 substantially corresponds to that of the first embodiment, which in the third embodiment does not have the special cover 6, but is attached directly to the housing 108.

Disclosed is a continuously adjustable slide valve with a housing-fixed socket. This has a first region in which an inner sleeve serving as a valve slide is displaceably arranged, and a second region in which at least one passage recess is provided. The first region of the socket fixed to the housing is surrounded by a first annular space, which is connected to a first main connection of the slide valve. The second region of the socket fixed to the housing is surrounded by a second annular space which is connected to a second main connection of the slide valve. For adjusting the flow cross section between the two annular spaces are in the inner socket and in the

housing-solid socket each provided a plurality of slots extending in the circumferential direction of the respective bushing, and which are axially spaced from each other. When moving the inner sleeve, the slit can be covered at the same time and pushed the pressure medium connection with it or increased in their coverage and the pressure fluid connection can be opened with it.

LIST OF REFERENCE NUMBERS

1 longitudinal axis

2; 202 valve slide

3; 103 main section

4 socket

6 lids

8th; 108 housing

10 first annulus

12 second annulus

14 seal

16 recess

18 socket-side slot

20; 120 valve spool side slot

22 opening

24 electromagnetic actuator

26 coil

28 contact

30 anchors

32 pestles

33 snap ring

34; 234 pole

36; 236 connection disc

38 spring

39 spacer

40 first closure

42 second closure

44 through-hole

146 ring

148 rib

250 tank channel 252 insert element

254 sealing piston

A output connection

P input terminal

T tank connection

Claims

claims

1 . Gate valve having a housing (8) in which a first port (P) and a second port (A) are formed, and a bush (4) inserted into the housing (8), in which a sleeve-shaped main section (3; a plurality of valve slide side slots (20; 120) along the circumference of the main section (3; 103) and a plurality of sleeve-side slots (18) along the circumference of the sleeve (4) ), whereby parallel control edges of the slide valve are formed, characterized in that in the housing (8) on the outer circumference of the bushing (4) connected to the first port (P) first annular space (10) and axially adjacent to one with the second Connection (A) connected second annular space (12) are arranged, wherein the first annular space (10) via the slots (18, 20; 120) with an inner space of the bushing (4) is connectable, and wherein the interior via openings ( 22) with the second annulus ( 12) is connected.

2. Gate valve according to claim 1, wherein the valve slide side slots (20) are circular arc-shaped and are arranged offset from each other at the periphery of the Hauptab- section (3;

3. slide valve according to claim 1, wherein the valve slide side slots (120) between rings (146) of the main portion (103) are arranged and thus full.

4. Slide valve according to one of the preceding claims, wherein the socket-side slots (18) are circular arc-shaped and thereby arranged offset from one another on the circumference of the bushing (4).

5. Gate Valve according to claims 2 and 4, wherein the valve slide-side slots (20; 120) and the socket-side slots (18) are of equal length.

6. Slide valve according to one of the preceding claims, wherein the valve slide side slots (20; 120) and the socket-side slots (18) can be brought into coincidence with each other.

7. Slide valve according to one of the preceding claims, wherein the socket-side slots (18) on the inner circumference of the bushing (4) are formed, while on the outer circumference of the bushing (4) recesses (16) are formed, which connected to the socket-side slots (18) are, and whose extent in the circumferential direction is smaller than that of the socket-side slots (18), and whose axial extent is greater than that of the socket-side slots (18).

8. slide valve according to one of the preceding claims, wherein adjacent to a first end face of the bushing (4) an actuator (24) is arranged, which is operatively connected to a rod (34) of the valve spool (2; 202), and wherein in the region of second end face of the bushing (4), a spring (38) is arranged, which counteracts the actuator (24).

Gate valve according to claim 7 and 8, wherein the total cross section of the recesses and the total cross section of the sleeve side slots (18) and the total cross section of the valve slide side slots (20; 120) and the opening between the main portion (3; 103) and the rod (34 ) and the total cross section of the openings (22) of the bushing (4) are the same size.

10. gate valve according to claim 8 or 9, wherein at one end portion of the main portion (3) which is arranged adjacent to the first end face, a connecting disc (36; 236) is provided, via which the main section (3) is connected to the rod (34; 234).

1 1 .S slide valve according to one of the preceding claims, wherein the valve spool (2; 202) is pressure balanced.

12. Slide valve according to one of claims 8 to 10, wherein a first seal in the region of the first annular space (10) or in the region of the first end face of the bushing (4) is arranged, and wherein a second seal in the region of the second annular space (12). or in the region of the second end face of the bush (4) is arranged.

The spool valve of claim 12, wherein the first seal is disposed on a first closure (40) inserted in the first end face, and wherein the second seal is disposed on a second closure (42) inserted in the second end face is where both seals the interior of the socket (4) seal.

The spool valve of claim 13, wherein the rod (34) penetrates the first closure (40), and wherein the spring (38) is supported on the second closure (42).

A spool valve according to claims 10 and 12, wherein the first seal is disposed at the end portion of the main portion (3), and wherein the second seal is disposed at a seal piston (254) of the valve spool (202).