EP0900963B1 - Seat valve - Google Patents

Description

The invention relates to a seat valve specified in the preamble of claim 1 Art.

Such seat valves, known from prior use in practice, as a rule Black / white valves have a switching magnet as the adjustment drive, which , Locking element adjusted against a spring. In the simplest version (2/2-way seat valve) are the two ways from each other in the locked position of the closing member Cut; in the through position of the closing member, however, with each other connected. The lock for holding the locking element in the shut-off position is formed by the switching magnet and the spring. As such seat valves usually Working with very small strokes of just a few 1/10 mm is an exact and therefore expensive coordination between the switching magnet and the spring required.

A 3/2-way seat valve with electromagnetic actuation known from EP-A-0 492 242 has a two-way locking for the locking members Rocker arm on by a spring in the direction of rotation and in the respective Closing direction is then acted upon when it reaches its pivot dead center in one or other direction. There is a lot of space for locking needed. The closing force that can be generated for the closing element is low.

From DE-C-1 005 794 a change seat valve is known, the two closing members are coupled via a connecting lever pivotally mounted in the housing. The link lever carries a control cam with an apex. One in Ball with linear movement and loaded by a compression spring lies on the control cam. The locking is structurally complex and stressed lots of installation space.

In a fuel nozzle known from GB-C-313 653 are around an adjustment stem the closing member distributed several balls in the circumferential direction, which in the housing bores are guided radially movable. Each ball is replaced by one in the case supported compression spring applied via a pressure tappet. This is latching structurally complex and takes up a lot of space.

In a quick-closing valve known from DE-C-10 29 639, the adjustment shaft carries of the closing member a ball, which during the opening or closing movement of the Closing member between two spring-loaded, counteracting sliding elements is squeezed through.

In a slide valve known from US-A-4 796 860 are on a slide adjustment shaft two axially spaced, circumferential ribs are provided between which have a cylindrical surface. In an outer valve sleeve in radial Bores with movably supported balls are radial by a C-shaped tension spring pressed inwards or only by a rubber cap surrounding the sleeve. This lock does not generate any holding force in the closed position and requires provide a seal against the pressure side.

The invention has for its object a seat valve of the type mentioned to create that structurally simple, inexpensive to manufacture and with low energy consumption adjustable and yet lockable with high force.

The object is achieved according to the invention with the features of claim 1 solved.

In the shut-off position of the seat valve, the adjustment drive can remain ineffective or be switched off, because the latching the closing member in the shut-off position holds. Because with a seat valve, a leak-free shut-off position has a certain shut-off position holding force required, the mechanical, positive and non-positive Then the catch will not be in a weak or relaxed position, but in an intermediate position in which they hold the locking member with the blocking position presses and holds against the valve seat. The holding force is determined by the frictional connection the latching in interaction with the form closure. The latch leaves can be integrated into the seat valve in a structurally simple manner is simple and inexpensive. Since the adjustment drive only for initiating one Adjustment is needed, the seat valve can be used with little energy and therefore adjust with a simple and inexpensive adjustment drive. This Advantages are achieved with the artifact that the catch does not reach a powerless position to let them but over the locking member in an axially exciting intermediate layer intercept. There is a relatively high holding force of appropriate in each case several balls acting together. The latching can be done on a small scale Accommodate installation space and is able to, despite that usually with seat valves extremely short strokes to remain effective in both stroke end positions with a holding force. O-rings as spring elements for the frictional connection are inexpensive, need extremely small installation space, and are immune to the hydraulic medium. With Only one O-ring can hold a relatively large number of balls uniformly. The The valve is compact despite the integrated lock.

According to claim 2, the accommodation of the O-rings in the circumferential groove of the sleeve to compact dimensions.

With angles of approximately 45 ° are according to claim 3 for both adjustment directions achieved essentially symmetrical force ratios. However, it is if necessary conceivable, for example by different angles, and / or different Spring forces different holding forces in both switching positions of the closing element to achieve.

According to claim 4, the lock is from the working area of the closing member laid.

According to claim 5 is caused by the clearance for safety reasons that the latching the holding force for the closing element is generated without being in a relaxed position to be able to get there.

According to claim 6, the straight passive latching does not generate a disruptive counterforce for active locking. In addition, the closing member is in the adjustment supports the two catches in the respective adjustment direction. The adjustment drive only needs to generate the adjustment pulse.

According to claim 7, the manufacture and assembly of the seat valve are simplified. The latching can be accommodated well, without such proven training concepts To adversely affect seat valves.

This also applies to the embodiment according to claim 8, in which the O-rings Support on the pressure sleeve to ensure a strong radial preload of the balls to create. The assembly is facilitated by the funnel-shaped widening which easily slides the sleeve over the O-rings and compresses them.

According to claim 9, a mechanical latching is for both shut-off positions provided so that the seat valve is bistable without the influence of the adjustment drive. A spring that the adjustment drive would have to overcome in between is not required.

According to claim 10, the latching is an adjusting auxiliary drive for the closing element, which largely relieves the actual adjustment drive.

Fig. 1

schematisch einen Schnitt durch ein 2/2-Wegesitzventil mit Verstellung von außen,

Fig. 2

in symbolischer Darstellung ein mittels zweier Schaltmagneten verstellbares 3/2-Wegesitzventil,

Fig. 3

eine Gesamtansicht, teilweise im Schnitt, des Sitzventils entsprechend der symbolischen Darstellung von Fig. 2, und

Fig. 4

einen vergrößerten Detailschnitt zu Fig. 3.

Embodiments of the subject matter of the invention are explained with the aid of the drawing. Show it:

Fig. 1

schematically a section through a 2/2-way seat valve with adjustment from the outside,

Fig. 2

in symbolic representation a 3/2-way seat valve adjustable by means of two switching magnets,

Fig. 3

an overall view, partially in section, of the seat valve corresponding to the symbolic representation of Fig. 2, and

Fig. 4

3 shows an enlarged detail section for FIG. 3.

A poppet valve S in Fig. 1, e.g. a 2/2-way seat valve, has a in a housing 1 Valve seat 2 for cooperation with a closing member 3, which deals with a seat 3a can be placed on the valve seat 2. The valve seat 2 is between flow paths A, C provided. In the shut-off position of the seat valve S shown, the Connection between paths A, C broken.

To adjust the closing member 3 between the shut-off position shown and one lifted through position, an adjustment drive 5, 7 is provided, which with the closing member 3 is connected, for example, via the elements 4, 6. An axial force holds in the direction of the dashed arrow or a blocking position holding force Z. the closing member 3 in the shut-off position. A force in the direction of the extended, upward arrow moves the closing member 3 to the open position. The adjustment drive 5, 7, which is, for example, in two parts, can either be operated manually operate or consists of switching magnets or is operated by a hydraulic or pneumatic pilot control.

In the shut-off position shown, the seat valve S is actuated by a mechanical, and frictional locking R held. An element 8 is in the latching two oppositely sloping cam surfaces N1 and N2, e.g. provided on part 4. The cam surfaces N1 and N2 are acted upon by a cam member F, which is loaded by a spring G. The cam member F produces thanks to the shape and Force closure and the force of the spring G, the blocking position holding force Z for the Locking member 3, since the locking R of the locking member 3, at least in the shut-off position, is prevented from reaching a relaxed position. If the adjustment drive 5, 7 actuated in the direction of the upward-pointing, drawn arrow, then the catch R is released and the cam follower F from the cam surface N1 brought to the cam surface N2, whereby the closing member 3 in the open position held and then optionally with an upward Force is applied. The adjustment drive 5, 7 is because the locking R as an adjustment auxiliary drive acts in both adjustment directions, only required as an adjustment pulse generator 12, 11, to initiate an adjustment of the seat valve S, which then runs automatically, until a stable position of the closing element is reached again. That is how it is Seat valve S is bistable even without the adjustment drive, i.e. that in that one locked position of the locking member remains until a new one in the opposite impulse is introduced.

A 3/2-way seat valve S is shown in a symbolic representation in FIG creates the connection between two paths C, B or C, A and thereby the connection to the third route A or B. Two are used as adjusting drives 5, 7 Switching magnets with opposite directions of action, which may only be adjusting adjusting devices Form I1 and I2 because the poppet valve with a mechanical catch R is equipped, which in the two shut-off positions of this seat valve S Closing member holds with axial holding force.

The structure of the seat valve according to FIG. 2 is indicated in FIG. 3, partly in section. The two switching magnets 5, 7 are then energized via connections 9, if the seat valve S is to be adjusted. The switching magnets are adjustable pulse generators and can be switched off or de-energized after the adjustment.

In the housing 1 is in a housing bore 10 equipped with the locking R cartridge-like insert 11, which contains the closing member 3, which means the switching magnet M1, M2 of the adjustment drive 5, 7 is adjustable back and forth. The stroke of the seat valve is indicated by X and is relatively small. For example, it is only a few 1/10 mm, e.g. 0.5 mm. The elements 4, 6 are plungers with which the Switching magnet transmit the respective adjustment pulse to the closing element 3. The The detailed structure of the seat valve in FIG. 3 is explained with reference to FIG. 4.

4, the cartridge-shaped insert 11 in the housing bore 10 is enlarged and shown in longitudinal section. The closing member 3, which in the embodiment shown is arranged on an adjustment shaft 3 ', in a two-part sleeve 12a, 12b linearly adjusted. A valve seat 2a, 2b is formed in each sleeve part 12a, 12b. The two valve seats 2a, 2b mutually cooperate with the seat surfaces 3a1 and 3a2 of the closing member 3, in order (see symbol in FIG. 2) either path A with the path Connect C and thereby shut off B from A, C, or connect B to C, and shut off A from C, B The seat surfaces 3a1, 3a2 are for example conical, while the valve seats 2a, 2b from the mouths of cylindrical bores be formed. The plunger engages at the lower adjusting end 3c2 of the closing element 3 6 on, while at the upper adjusting end 3c1 the plunger 4 of the other switching magnet attacks.

The catch R is contained in the cartridge-shaped insert 11. In the mess 3 'two axially spaced circumferential grooves 19 are formed, which are opposite to each other have inclined groove flanks 21 and internal spaces 20. The groove flanks 21 form the cam surfaces N1, N2, which in the embodiment shown formed as a rotationally symmetrical conical surfaces to the axis of the closing member 3 are.

In the left half of FIG. 4, the seat surface 3a2 sits on the valve seat 2b while in the right half of Fig. 4, the other seat 3a1 on the second valve seat 2a sits on. These are the two switching positions of the seat valve S by the Locking R are observed, with the closing member 3 in each switching position a blocking position holding force generated by the latching R on the respective Valve seat is pressed.

A plurality of balls 16 serve as cam members F of the latching R, which are arranged axially in two spaced radial bore rows 15 in the sleeve part 12a guided radially movable are. A cylindrical circumferential section may lie between the two cam surfaces N1, N2 with a slightly reduced diameter of the adjustment shaft 3 '. aligned on the radial bore rows 15 there are two outwards in the sleeve part 12a Open circumferential grooves 14 are formed, in which the balls 16, ring-shaped Spring elements G are arranged. In the embodiment shown acts it is in each case an O-ring 22 which is knotted into a circumferential groove 13 and is under radial prestress, so that the balls 16 acted upon by it against the adjustment shaft 3 'are pressed inwards. For assembly or replacement the O-rings 22 is a pressure sleeve 17 with a reduced diameter End portion 13 of the sleeve part 12a is pushed, on which the O-rings 22nd support inside, so that they with their tension and compression Act. For easier assembly, an inner end of the pressure sleeve 17 is included a funnel-shaped expansion 18 is formed.

The angle α, which each cam surface N1, N2 encloses with the axis of the closing member 3, is, for example, 45 °. After selecting the number of balls 16, the Hardness or compression of the O-rings 22 and / or the angle α of each cam surface N1, N2 it is possible to use the same blocking position holding forces or different ones Set the blocking position holding forces Z. So that the latching the respective Shut-off position holding force can be the axial distance between the cam surfaces N1, N2 so matched to the stroke of the closing member 3 that in the respective Locking position, the balls 16 in a radial bore row their assigned Fully apply cam surface while the balls of the other radial bore row sit on the cylindrical outer circumference of the adjustment shaft 3 '. With this Voting is also achieved that the locking R when adjusting the closing member helps between the two shut-off positions, so that the adjustment drive only needs to generate an adjustment pulse and then at least the actual adjustment largely runs automatically.

Claims (10)

1. Seat valve (S) having at least one closing member (3), the closing surface (3a, 3a1, 3a2) of which cooperates with at least one valve seat (2, 2a, 2b), having an adjusting drive (5, 7) for adjusting the closing member in order to shut off or open up the valve seat, and having a positive and non-positive locking means (R) which acts upon the closing member (3), can be released by the adjusting drive (5, 7) and is intended for retaining the closing member, at least in the shut-off position, on the valve seat with a shut-off position retaining force (Z) acting in the closing direction, characterized in that axially spaced annular grooves (19) are provided on the closing member (3), in that balls (16) are mounted in at least two axially spaced holes (15) orientated in the circumferential direction, in a sleeve (12a, 12b) surrounding the closing member, and in that each ball (16) is acted upon in each hole with radial prestressing by an O-ring (22) which encircles the sleeve in the region of the respective hole.
2. Seat valve according to Claim 1, characterized in that each O-ring (22) is arranged in an outer circumferential groove (14) of the sleeve and is supported on a wall surrounding the sleeve, and in that in each case a plurality of holes (15) aligned in the circumferential direction and having radial axes form a group of holes.
3. Seat valve according to Claim 1, characterized in that the annular groove has at least one slope or rounded groove flank (21) which is inclined with respect to the axis of the closing member (3) preferably at an angle (α) of approximately 45°.
4. Seat valve according to Claim 1, characterized in that the annular grooves (19) are arranged on an adjusting shank which is connected to the closing member (3) and is contained in the sleeve (12a, 12b).
5. Seat valve according to Claim 3, characterized in that a clearance (20) is provided on the inside adjacent to the groove flank (21), and in that the axial distance between the ball (16), the groove flank (21) assigned to it and the seat surface (3a1, 3a2) of the closing member (3) is selected in such a manner that in the shut-off position, the ball (16) is pressed onto the groove flank (21) and a radial play for the ball (16) is maintained in the clearance.
6. Seat valve according to at least one of the preceding claims, characterized in that the groove flanks (21) in their axial width, the diameters of the balls (16) and their axial distance are coordinated with one another in such a manner that within a closing-member/stroke travel (X) of approximately 0.5 mm in an alternating manner the one ball sits on its groove flank and the other ball releases its groove flank.
7. Seat valve according to at least one of the preceding claims, characterized in that two valve seats (2a, 2b) are formed in a sleeve (12a, 12b) which is divided between the valve seats, is inserted into a housing hole (10) and holds the closing member (3) in a sealed and displaceable manner such that adjusting ends (3c1, 3c2) of the closing member (3) are accessible at both ends of the sleeve, and in that the latching means (R) is provided between the adjusting ends in the sleeve and on the closing element.
8. Seat valve according to at least one of the preceding claims, characterized in that an end section (13) of the sleeve (12a, 12b), which section is reduced in diameter and has the two O-rings (22), is encircled by a pressure sleeve (17) which, preferably, has a funnel-shaped widened area (18) in one end.
9. Seat valve according to Claim 1, characterized in that in the case of two valve seats (2a, 2b) and a single closing member (3) having two closing surfaces (3a1, 3a2) or in the case of two connected closing members each having a closing surface (3/2-directional seat valve or 2/2-directional seat valve), a respective mechanical latching means (R) is provided for both shut-off positions.
10. Seat valve according to at least one of the preceding claims, characterized in that the latching means (R) is designed from its respective release point as an auxiliary adjusting drive for the closing element (3).

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