DE1911827A1 - magnetic valve - Google Patents

Description

E. 9413
5.3.1969 Ka / km

Attachment to
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Utility model help & ^registration

BOBERO? BOSCH GMBH, Stuttgart W, Breitscheidstrasse Solenoid valve

The invention relates to an electromagnetically actuated valve, in particular for fuel injection in internal combustion engines, with one inside a steel jacket against the force of a Helical spring axially displaceable valve needle.

B. in known valves of this type, in which the lift height is varied by changing the control pulse amplitude, has been found posed that any stable lifting height can only be very high

009838/1141

ORIGINAL INSPECTED -

Robert Bosch. GmbH _{Ό oyM} , «· / design._ '

Stuttgart ^{E 94> 15 Ka / km}

difficult to reach because the stroke stop does not come into effect and thus an unstable equilibrium arises. It has been shown that the smallest disturbance variable on the valve needle the hysteresis properties of the lifting magnet cause a build-up the stroke movement of the valve needle. '

The invention is therefore based on the object of a solenoid valve to create that does not have the disadvantages mentioned, and in which any variation of the lifting height is possible.

The object can be achieved in that the stroke of the valve needle is adjustable with the help of a stop designed as an armature of an electromagnet.

Further details and advantages of the invention result in connection with the subclaims from the following description, of an embodiment and from the accompanying drawing, which shows a solenoid valve in section.

A valve needle 3, which can be displaced in the axial direction against the force of a helical spring 2, is arranged in a steel jacket 1. The upper end of the valve needle is guided within a coil 4-, which attracts the valve needle in the rhythm of the pulse train when excited with an in particular right angular pulse train, whereby a in the lower part of the steel jacket attracted; arranged nozzle 5 is alternately released and closed by the valve needle. On the valve needle 3, a collar 6 is provided which strikes against a stop 7, whereby the stroke of the valve needle 3 is limited. I \

To the. The stop 7 is used to vary the stroke of the valve needle 3 designed as an armature of an electromagnet, the coil 8 of which is arranged concentrically to the coil 4 within the steel jacket 1. The coil 8 can be changed with a direct current

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0098 38/11 «1 _{oBietJiAL msPE0T6D}

~ 5 -

Robert Bosch GmbH «, culA * vaACm

Stuttgart fi. W3Ka / km

had been excited to a great extent, causing the anchor to move against «Ine helical spring 9 is supported, is tightened to different degrees, and the spring 9 more or less together. presses. The position of the armature 7 thus results as a resultant from the magnetic force corresponding to the level of the direct current and the spring force of the spring 9> The armature 7 reaches its stable position where the magnetic force and spring force cancel each other out. In order to avoid vibrations when the collar 6 hits the stop 7 on the valve needle, a relatively large ratio of the mass of the stop to the mass of the valve needle is to be selected. Likewise, the The spring constant of the coil spring 9 should be large compared to the Spring constant of coil spring * 2,

009838 / 1U1

Claims (3)

Robert Bosch GmbH _ αι, Λΐ- rrD / vm Stuttgart · R · W5 Ka / Km claims ^ Λ ■ 1. jElektromagnet! Sch actuatable valve, in particular for / fuel injection in internal combustion engines, with a valve needle displaceable in the axial direction within a steel jacket against the force of a helical spring, characterized in that the stroke of the valve needle (5) with the aid of an armature (7) an electromagnet trained stop is adjustable. 2. Valve according to claim 1, characterized in that the armature (7) when the electromagnet is switched on against the force a helical spring (9) is tightened, 3. Valve according to claim 1 or 2, characterized in that the electromagnet is designed as a lifting magnet. 009838 / 1U1 OHiGINAL IMSPSCTED