GB2256915A

GB2256915A - Valves for pneumatic media

Info

Publication number: GB2256915A
Application number: GB9211605A
Authority: GB
Inventors: Helmut Goettling; Rudolf Moeller; Gerhard Scharnowski
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1991-06-17
Filing date: 1992-06-02
Publication date: 1992-12-23
Also published as: GB9211605D0; SE9201724D0; DE4120292A1; FR2677728A1; FR2677728B1; DE4120292C2; ITMI921258A0; IT1255063B; SE9201724L; ITMI921258A1

Description

12 2 _) 0, i." 15 1 VALVES FOR PNEUMATIC MEDIA The present invention

relates to valves and particularly concerns valves for pneumatic or gaseous media.

It is known from German published application Al-29 34 181 to use an Integral valve body for two series-connected valves to be operated In dependent fashion.

In the aforementioned publication there are provided a first pressure medium input chamber assigned to the first valve, and a second pressure medium Input chamber assigned to the second valve, and a pressure medium output chamber which, via the first valve and the second valve, can be connected to and shut off from the first pressure medium input chamber and the second pressure medium input chamber simultaneously.

By the provision of two pressure medium input chambers which can be connected simultaneously to the pressure medium output chamber via the two valves, It Is possible to release large opening cross-sections with small movements of the valve bodies.

A disadvantage of the known arrangement comprising two valve bodies rigidly connected to one another consists in that it cannot be ruled out that, for example due to production tolerances, during a closing phase of the two valves one of the two valve bodies may not be exactly positioned on its associated valve seat with the result that leaks can occur.

A further disadvantage of the known valve device consists in that the production of stem and housing must be carried out with extreme precision as otherwise the stem may become jammed. In particular, the necessity for a highly accurate, i.e. costly. production of valve bodies and valve housing renders the known design uneconomical.

The present Invention Is aimed at the problem of facilitating a more economical and precise production of the valve bodies and the valve housing in order to prevent jamming of the valve bodies and leaks.

A 2 According to the present invention, there is provided a valve comprising a valve housing on which is secured an electromagnet having an armature which cooperates with a valve body, wherein the valve housing is provided with media terminals, and there are provided in the valve housing a first valve seat and a first valve body which together form a first valve, and a second valve seat and a second valve body which together form a second valve, and wherein the valve bodies with their valve seats are arranged coaxially with one another, and wherein the two valve seats are each closed by separate valve bodies, of which the second valve body, which is more remote from the electromagnet, consists of a second valve disc with guide rods extending coaxially on both sides, and the other valve body, which cooperates with the armature, consists of a first valve disc against which the first guide rod of the more remote valve body abuts under pressure and/or spring force, and wherein at least one stem shaft is formed on the first valve disc, and extends towards the armature, which stem shaft either abuts at its end against the end face of the armature or itself forms the armature.

The advantages attained by the invention consist in particular in that, in the case of separate valve bodies, both the production of the simpler valve bodies and the production of the valve housing can be carried out with sufficient accuracy but observing less precise tolerances, where, for example, the housing bores can be worked from two sides, and that simpler individual parts In the form of the separate valve bodies are obtained, thereby facilitating a simplified production and assembly.

Advantageous developments of the invention are described in the-subclaims.

Thus it is also advantageous, in order to avoid leaks, that opposite the valve sealing edge the valve discs are each provided with a sealing ring.

An advantageous measure with respect to the separate valve bodies consists in that the second stem shaft which cooperates with the electromagnetic armature comprises a hollow shaft component for the accommodation of the electromagnetic armature.

3 The valve also fulfils different functions in that the electromagnet consists of a pulling or pushing proportional magnet or a switching magnet.

Exemplary embodiments of the invention will now be described in detail. with reference to the accompanying drawings, in which:

Figure 1 is an axial cross-section through a first exemplary embodiment of the valve including a pulling proportional magnet or a switching magnet; Figure 2 is an axial cross-section similar to Figure 1 of a second exemplary embodiment of the valve, including a pushing proportional magnet; Figure 3 is an axial cross-section similar to Figure 1 of a third exemplary embodiment of the valve, utilising a pushing proportional magnet; and Figure 4 is an axial cross-section similar to Figure 1 of a fourth exemplary embodiment of the valve, including a pushing proportional magnet.

The valve, which may be used for example as a directional control valve for pneumatic media. comprises a valve housing 1 with an electromagnet 2. The valve housing 1 includes a main valve bore 28, and on one side is closed by a cover 3 with a sealing element 4 connected to the valve body 1 by means of screws 5. Media terminals A (operating line) and P (pressure line) are provided on the valve housing 1 and the cover 3. The armature 6 of the electromagnet 2 cooperates with a first valve body 7 associated.with a first valve seat 8. A second valve seat 9 with a second valve body 10 is also provided. The valve seat 8 with the valve body 7 form a first valve 11, and the valve seat 9 with the valve body 10 form a second valve 12.

The two valve seats 8 and 9 are each closed by separate valve bodies 7 and 10. The second valve body 10. which Is more remote from the electromagnet 2, comprises a second valve seat disc 13 which is produced integrally with first and second guide rods 14a and 14b extending coaxially on both sides of the disc. The first 4 valve body 7, which cooperates with the armature 6, consists of a smooth, first valve disc 15 which is flat on one side and is formed with a stem shaft 16 on its face facing towards the armature 6. The stem shaft 16 may either abut at its end face against an end face 6a of the armature (Figures I to 3) or may itself form the armature 6 (Figure 4).

The first guide rod 14a of the second valve body 10 abuts against the valve disc 15 which is flat on one side, and is subject to the spring force of a conical spring 17.

The stem shaft 16 is coupled to the electromagnet 2 via a release device. For this purpose firstly (Figure 1) an armature guide tube 18 is guided to a recess 19, is sealed with a O-ring 20 and is bolted by means of discs 21 and a threaded nut 22. Inside the armature guide tube 18 is arranged a longitudinal guide slot 23 and within the armature 6 is arranged a release member 24, against the collar of which a compression spring 25, which is also supported against the stem shaft 16, abuts. The electromagnet 2 is additionally equipped with electrical contacts 26 and_27 and, depending upon the mode of functioning of the valve, consists of a pulling proportional magnet or a switching magnet.

In the valve housing I a stepped seat bush 29 is inserted from below into the valve bore 28, the guide rod 14b being slidably received in a central bore 30 of said seat bush 29. The seat bush 29 is also maintained in its position by means of spherical torsion protection means 31 subject to the force of a threaded pin 32.

A further seat bush 33 Is provided, by means of a sealing element 34, in the course of the stepped valve bore 28 for the first valve 11.

The valve discs 13 and 15 are also each provided, opposite a valve sealing edge 35, with a sealing ring 36 (Figure 2).

The stem shaft 16 which cooperates with the armature 6 comprises a hollow shaft component 37 which serves to accommodate the armature 6, as illustrated in the other exemplary embodiments.

The second embodiment as shown in Figure 2 differs in respect of a few features from the first embodiment illustrated in Figure 1. The stem shaft 16 possesses, with respect to the armature 6, tolerance compensation means in the form of a tolerance compensation disc 38. The stem shaft 16 is also surrounded by a guide bush 39 and a seat bush 33 in which a sealing element 34 is arranged. The guide bush 39 and the seat bush 33 are thus formed as one piece. In the region of the second valve 12 the guide rod 14b is supported by a governing spring 40 which is mounted in an adjusting bush 41. The adjusting bush 41 is itself accommodated by the seat bush 29 which is sealed in the valve bore 28 by means of a sealing ring 42.

The third embodiment, illustrated in Figure 3 provides an armature 6, the end face 6a of which abuts directly against the stem shaft 16. The valves 11 and 12 are constructed as described. The seat bush 33 with the sealing element 34 is likewise inserted as described above, as is the seat bush 29 with the seal 24. Here again a governing spring 40 is employed, against which the guide rod 14b is supported. The seat bush 29 is likewise equipped with spherical torsional protection means 31 as in the preceding exemplary embodiment. The media terminals A and P are arranged in opposition and in alignment as shown.

The fourth embodiment, shown in Figure 4 is constructed similarly to the embodiment shown In Figure 1, with the fundamental difference that the stem shaft 16, which cooperates with the armature 61 is produced from one single component on which the valve disc 15 is additionally formed. The electromagnet 2 consists of a pushing proportional magnet, for which reason the governing spring 40 can also be dispensed with here. The media flow Is from the media terminal P, a recess 43 and the media terminal A (operating line) located downstream of the valves 11 and 12.

The two stem elements (in each case valve body 7, guide rods 14a. 14b and valve disc 15) in the version Illustrated in Figures 2 and 3 can also be of Identical construction.

6

Claims

A valve comprising a valve housing on which is secured an electromagnet having an armature which cooperates with a valve body.

wherein the valve housing Is provided with media terminals, and there are provided in the valve housing a first valve seat and a first valve body which together form a first valve, and a second valve seat and a second valve body which together form a second valve, and wherein the valve bodies with their valve seats are arranged coaxially with one another, and wherein the two valve seats are each closed by separate valve bodies, of which the second valve body...

which is more remote from the electromagnet, consists of a second valve disc with guide rods extending coaxially on both sides, and the other valve body, which cooperates with the armature, consists of a first valve disc against which the first guide rod of the more remote valve body abuts under pressure and/or spring force, and wherein at least one stem shaft is formed on the first valve disc, and extends towards the armature, which stem shaft either abuts at its end against the end face of the armature or itself forms the armature.
2. A valve as claimed in Claim 1. in which the valve discs are each provided with a sealing ring opposite their respective valve sealing edges.
3. A valve as claimed in Claim 1, in which the second stem shaft which cooperates with the armature comprises a hollow shaft component to receive the armature.
4. A valve as claimed In Claim 1, wherein the electromagnet consists of a pulling or pushing proportional magnet or a switching magnet.
5. A valve substantially as described herein with reference to Figures 1, 2, 3 or 4 of the accompanying drawings.