GB2270799A

GB2270799A - Electromagnetically actuable valve with disc armature.

Info

Publication number: GB2270799A
Application number: GB9317468A
Authority: GB
Inventors: Bernd Groll; Werner Brehm; Erwin Krimmer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1992-09-19
Filing date: 1993-08-23
Publication date: 1994-03-23
Also published as: DE4231428A1; GB9317468D0; JPH06193763A

Abstract

The electromagnetically actuable valve has a housing casing (10) which receives the coil (12) and the coil core (13). A pole disc (20) and a flange component (21) are fixed by the lower part of the housing casing by means of a flange of the housing casing (10). Between the pole disc (20) and the flange component (21), a cylindrical recess (29) is formed in which a disc armature (30) is located. The latter receives the valve body (32) in a central bore. The pole disc (20) is provided with a layer (45) of non-magnetic material and is manufactured from an appropriate layer or composite material. In this way, no residual air gap disc which is difficult to instal is required. This arrangement prevents 'sticking' of the armature to the pole disc. <IMAGE>

Description

2270799

Electromagnetically actuable valve with disc armature Prior art

The invention is based on an electromagnetically actuable valve of the generic type of the main claim. A valve of this kind is disclosed for example in DE-GX 87 11 602. In order to. ensure reliable operation with such a valve even at high clock frequencies,, a socalled residual air gap disc is attached between the disc armature and the end side of the pole disc f acing the said armature. This residual air gap disc consists of a non-magnbtic material, for example plastic, and is only several tenths of a millimetre thick. The residual air gap disc is usually clamped in between pole disc and f lange component of the valve by being f itted onto the pole disc during the installation of the valve bef ore the insertion of the flange component and being fixed by the f itting on of the f lange component. By means of such a residual air gap disc, the intention is to prevent the disc armature remaining "stuck" to the pole disc after the electromagnet is energised. By means of the nonmagnetic residual air gap disc between disc armature and pole disc, an immediate release of the disc armature after the energising of the electromagnet is terminated is made possible. As a result of their geometry. residual alr gap discs of this kind have the disadvantage that they can be very easily damaged during installation and that their installation is very difficult to handle. Furthermore, during industrial manual installation of such valves it is very often the case that the residual air gap disc is not inserted or that a plurality of residual air gap discs are laid one on top of the other. As a resulti on the one hand. a reliable release of the disc armature is not always ensured and, on the other hand, changes in the valve characteristic curve are caused.

Advantages of the invention In contrast with the above, the electromagnetically actuable valve according to the invention, having the characterising features of the main n.laim, has the advantage that a reliable and rapid operation of the solenoid valve is possible and that, above all. the installation of this valve is made easier. As a result of the omission of an individual component which was previously difficult to handle, in particular series production is made easier. By virtue of the use of a pole disc of this kind, 'constant material characteristic values and dimensions are always ensured.

Further advantages of the invention result from the subclaims and from the description.

Drawing An exemplary embodiment of the invention is explained in greater detail in the subsequent description and drawing. The drawing shows a longitudinal section through an electromagnetically actuable valve.

Description of the example of the invention

In the drawing. the housing casing of the solenoid valve is designated by 10 and is formed in an approximate sleeve shape and has a plurality of openings 11 on its circumference. The coil 12 which is seated on a central coil core 13 is arranged inside the housing casing 10. A central bore 14 which is connected to a container 16 at one of its ends via a line 15 penetrates the coil core. At the said end. the housing casing 10 is sealed off by a flow plate 18. Here, the electrical connection parts 19 for making contact with the coil 12 are also arranged.

At the opposite end of the housing casing 10 or of the coil 12, there is a pole disc 20 to which a' flange component 21 is adjacent on the same axis. The latter components are permanently connected to 'the housing casing 10 by means of a lower flange 22 -of the said R. 25543 housing casing 10. Two continuous bores 23, 24 which extend parallel to one another and which are connected to a load (not illustrated) are formed in the flange component 21. Furthermore, in the centre of the flange components there is a blind bore 25 into which a transverse bore 26 opens, which transverse bore 26 starts from the outside of the flange component 21 and is connected via a line 27 to a pressure medium source 28. In a cylindrical and annular space 29 which is formed at the upper part of the flange component 21 and faces the coil core 13 a disc armature 30 is arranged with axial and radial play. The said armature 30 has a central bore 31 in which a spherical valve ' body 32 made of glass is pressed. On each side of the bore 31, continuous slots 30A, 30B are made in the disc armature 30. the said slots 30A, 30B being. however, not visible here since they are offset by 90 with respect to the plane illustrated.

The valve body 32 interacts with two valve seats 33, 34, one of wh ich is f ormed at the upper end of the bore 25 in the f lange component 21 and the other of which is f ormed at the lower edge of the bore 14 of the coil core 13. A compression spring 36 which is arranged in a cylindrical recess 37 on the outer circumference of the coil core 13 acts on the disc armature 30 and loads the disc armature in such a way that the valve body 32 is pressed onto the valve seat 33 when the electromagnet is not excited, i.e. when the coil 12 is not energised.

The entire valve is encapsulated with a plastic body 38 by injection moulding before the connection of the housing casing 10 to the pole disc 20 and to the flange component 21. The plastic body 38 has on its end side opposite the connection components 19 a cylindrical projection 42 which embraces the coil core 13 at a distance and is approximately flush therewith. By means of this cylindrical projection 42, an annular space 43 which is bound by the housing casing 10 or by the flange 22 is formed on the end side of the plastic body 38 and serves to receive the pole disc 20. This pole disc 20 consists of a ferromagnetic.carrier material 44 which is - 4 R. 25543 provided on both sides with a non-magnetic layer 45. In a modification, it is also possible only to provide the end side of the pole disc 20 facing the disc armature 30 with the layer 45. This layer 45 is for example a nonmagnetisable high-grade steel which is applied to the carrier material 44 by cold rolling and is connected permanently thereto. A particularly advantageous (composite) material for producing such a pole disc 20 is Platinox, a material which is manufactured by K18ckner Stahl GmbH, Bremen. The said material is a uniform, enclosed composite material in which the carrier material is plated with a high-grade steel. The carrier material 44 here is ferromagnetic and the layer 45 consists of non-magnetic high-grade steel. A uniform (composite) material of this kind can be easily worked, in particular punched or deformed. The material properties which are decisive for this are principally determined by the carrier material. In the present case, it is appropriate for the said material to be a material which is easy to punch.

Using a coated pole disc 20, permits all the advantages of a solenoid valve provided with a residual air gap disc and having a disc armature to be exploited. At the same time,, however,, the manufacturing outlay or the installation outlay on the valve is reduced since a component which can only be handled with great difficulty is omitted during installation. By using'for the manufacture of the pole disc an original material, such as for example Plat:Lnox, which is manufactured in large-scale series production, constant material characteristic values and dimensions, in particular thickness are ensured.

Furthermore, the use of a composite material of this kind has the advantage of high resistance to wear so that the non-magnetic layer 45 is substantially more durable and can withstand greater stresses than surfacecoated layers or similar layers which are to be applied subsequently.

A further advantage of the layer is the temperature stability.

Claims

1. Electromagnetically actuable valve with a housing casing (10) which receives a coil (12) and a coil core (13) to which a pole disc (20) and a flange component (21) provided with pressure medium channels (23 to 26) is attached. a disc armature (30) being located between pole disc (20) and flange component in a cylindrical intermediate space (29), characterised in that the pole disc (20) is provided at least on its side facing the disc armature (30) with a layer of non-magnetic material.

2. Valve according to Claim 1, characterised in that the non-magnetic layer (45) is permanently applied by rolling to a ferromagnetic carrier material (44).

3. Valve according to Claim 1 or 2, characterised in that the pole disc (20) consists of Platinox.

4. Valve according to one of Claims 1 to 3, characterised in that the housing casing (10), the coil (12) and the coil body (13) are embedded in a plastic body (38) on whose end side facing the flange component (21) a depression (43) for receiving the pole disc (20) is formed.

5. Valve according to one of Claims 1 to 4, characterised in that a central bore (31) is formed in the disc armature (30), in which bore (31) a spherical valve body (32) is permanently arranged.

6. Valve according to one of Claims 1 to 5. characterised in that the valve body (32) consists of non-magnetic material.

7. Valve according to one of Claims 1 to 6. characterised in that the valve body (32) consists of glass.

8. An electromagnetically actuable valve substantially as herein described with reference to the accompanying drawing.

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