DE8805727U1 - Electromagnetically operated control valve - Google Patents

Description

R.21779
30.3.1988 ffd/Kc

BECBERT BOSCH GMBH, 7000 Stuttgart 1

Electromagnetically actuatable control valve State of the art

The invention is based on a control valve according to the type of the main claim. Known control valves of this type generally consist of a large number of housing parts, which are relatively complex to construct using measures such as screwing, flanging the edge of the housing to form the magnetic part, and other measures.

Advantages of

The control valve according to the invention with the characterizing features of the main claim has the advantage that it is very simple in construction and also very easy to manufacture. With only minor differences, it can be manufactured as a normally open or normally closed valve. It is also advantageous that the complete unit, consisting of the spool element, housing pot and magnet pot, can be pre-assembled outside the injection mold, so that only one part has to be inserted into the injection mold. By completely encapsulating the coil, additional measures for securing the winding wire, such as bandaging, are no longer necessary.

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drawing

"■ Two embodiments of the invention are shown in the following

t Description and shown in the drawing. The latter shows in the

I Figures 1 and 2 each show a longitudinal section through an electromagnetic I table-operated control valve.

1 Description of the embodiments

i; Figure 1 shows an electromagnetically operated control valve in

djs ) Longitudinal section, which is closed without current. It consists of ^irem

V- one-piece housing 10, which is injection-molded from plastic in a mold

\ Inside the housing 10 are the winding 11 and in

j: a central bore 12 an anchor 13, from which the

; A tappet 15 is formed on the side facing away from the housing.

\ 6side, the housing 10 has an extension 15 with a central bore 16,

: which runs parallel to the armature 13. In the bore 16 a

A valve insert 17 is arranged, which has several locking lugs 18, which snap into matching recesses 19 of the extension 15 during assembly. A guide body 20, also made of plastic, is arranged between the armature 13 and the valve housing 17. Or several ribs 21 facing the armature 13 and also several

i has ribs 22 facing the open end of the valve housing 17«

■ Between the last-mentioned ribs 22 there is a spherical V«mtil-

member 24, which can rest on the one hand against a valve seat 25 and on the other hand against a valve seat 26. The valve seat 26 is formed on a through hole 27 of the guide body 20, the opposite valve seat 30 is located on a valve carrier 31, which is formed on the valve insert 17 and has a significantly smaller diameter than the longitudinal hole 32 of the valve housing 17. This creates passages 34, 35 that lead to the hole 32, which is connected to a consumer line (not shown). The consumer connection is marked with A

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A radial, continuous slot 40 is formed in the valve carrier 31, which is connected to a connection P for a pump.

At the transition between the housing 10 and the extension 15, a continuous slot 37 is provided, which opens at the level of the armature plunger 40. The slot 37 is connected to a container (not shown); its connection is marked T. On the

A=ksr 12 irirkt s ¹ — *~ ^&Lgr; ~- n*»hwn«w» 13 annanrAnat-.a Druekfadar 38 ain.

to which the bore 16 is connected.

The housing pot 41 of the control valve is made of metal, which is surrounded on all sides by an injection-molded plastic casing 42, which also forms the extension 15. A flat plug 44 is attached to the coil 40, which is located in the upper part of the housing 10. The plug connection 45 is also molded onto this part. A residual air gap 47 is formed between the inner end of the armature 13 and a retracted part 46 of the housing.

When the coil 40 is de-energized, the valve body 24 is pressed onto the valve seat 25 by the force of the compression spring 38 and the tappet 14 acting on the armature 13. The bore 27 is now open and the pressure medium entering the control valve at the consumer connection A reaches the container connection T.

If the magnet is excited, the armature is pulled towards the magnet pot. The valve body is thereby placed against the valve seat 26 by the pressure at the consumer connection A. Pressure medium can now flow from the pump through the recesses 46 into the interior of the control valve and to the consumer connection A, since the valve body 24 rests on the valve seat 26. Pressure is then built up at the consumer, and the pressure medium that continues to be delivered by the pump passes from the pump connection P to the tank connection T. This shows that the

21779

electromagnetically operated control valve is closed when the electromagnet is de-energized.

In the control valve according to Figure 2, this is just the opposite. This consists largely of the same parts as the control valve described above, only it is open when de-energized. The same parts as in the embodiment according to Figure 1 are retained. The difference is in the arrangement of the armature, which is now designated 50, and the hollow body 51, which faces the valve body 34. A through hole 52 is formed in the hollow body, through which a tappet 53 penetrates, which in turn acts on the valve body 24. When the magnet is not excited, the valve body lies on the valve seat 24 due to the pressure at the consumer connection A. The consumer connection A is now connected to the inlet of the pump P, i.e. the consumer is now supplied with pressure medium. When the magnet is excited, the armature is pulled to pole 55. Now the valve body 24 is lifted off the valve seat 26 by the tappet 53 and pressed onto the valve seat 25. The connection from &lgr; is now made via the valve seat 26 to the container connection T. This depressurizes the connection A.

The two solenoid valves described are simple, inexpensive and light, particularly due to the design of the plastic housing. In addition, many of the same parts can be used for the normally open and normally closed versions, such as the solenoid housing, nickel elements, housing pot, valve housing, etc. This results in significant savings compared to known valves, particularly with regard to the manufacturing costs and plastic injection molding parts.

The central element of the two solenoid valves is the magnet housing, which is manufactured using the injection molding process. This means that simple stamped and drawn parts (magnet pot, housing pot) can be used for the magnetic circuit.

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can be used because complex processes such as flanging, wobble riveting or caulking the housing to the inner part are no longer necessary.

The complete unit consisting of winding element, housing pot and magnet pot can be pre-assembled outside the injection molding tool so that only a part needs to be inserted into the injection mold. By completely overmolding the coil, additional measures to secure the winding wire, such as bandaging, are not necessary. In addition, it is sufficient to clip the flat plugs 44 into the coil body instead of inserting them into the injection mold, since the connection with the housing is made with the entire unit during injection molding.

Claims (2)

■·■· ·<&igr; «a ·■ a. 21779 J| 30.3.1988 Wd/Kc B ROBERT BOSCH GMBH, 7000 Stuttgart 1 Claims 1. Electromagnetically actuated control valve, the spherical valve body (24) of which can be switched by a tappet actuated by the armature (13, 50) and which interacts with two valve seats arranged in the housing in such a way that the control valves are open or closed when de-energized, whereby largely the same parts are used, characterized in that the housing is identical for both versions and consists entirely of plastic injected into the same mold, into which the previously pre-assembled internal parts are introduced into the mold, and that a valve housing (31) which is also identical for both versions is arranged in an opening of the control valve, on which guide ribs (21, 22) for the tappet and the valve body are located. 2. Valve according to claim 1, characterized in that a plug connection designed as a flat plug is also molded onto the housing.