DE2711140A1 - ELECTROMAGNETIC VALVE - Google Patents

Description

271-140

R. 38 TO

February 25, 1977 He / Hm

ROBERT BOSCH GMBH, 7000 STUTTGART Electromagnetically operated valve summary

An electromagnetically actuated valve is proposed, whose armature is guided and centered via leaf springs is. The pole surface of the armature is reduced by the inclusion of one leaf spring. To the said pole face again enlarge, a pole piece is used, which is placed on the armature. This way it is downsizing AW number possible.

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State of technology

The invention is based on an electromagnetically actuated valve according to the preamble of the main claim. One such Solenoid valve is known (DT-OS 2 403 770). at In this known solenoid valve, the pole face of the armature is reduced by the recesses for the leaf spring. This has the disadvantage that the number of ampere turns (AW number) required to move the armature into its tightening position must be enlarged. However, this requires greater power consumption and higher heating of the coil.

Advantages of the invention

The electromagnetic valve according to the invention with the characterizing features of the main claim has on the other hand the advantage that the necessary AW number can be reduced. When using the solenoid valve as a 3/3-way solenoid valve the force-displacement characteristics can then run almost horizontally. With such valve devices there is the problem of reconciling the spring forces with the magnetic forces. It must be taken into account that both the magnetic as well as the spring forces due to the hysteresis influences each in a certain spread are present. Pressure medium forces of varying sizes, frictional forces and the effects of dimensional tolerances result a relatively wide range of forces. In addition, it is at least advantageous for some purposes if the The valve lift is not too small, so that a certain minimum cross section is available for the flow of the pressure medium stands.

It is therefore a further advantage of the solenoid valve that, with as flat a force characteristic of the magnet as possible, an easy adjustment of the spring characteristic is ensured in order to ensure reliable switching of the armature both in its end positions with relatively large passage cross-sections and in its central position.

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Finally, according to a further feature of the invention, it is also advantageous that near the solenoid-operated End position of the armature the attraction force of the magnet is weakened in the end area of the armature stroke.

drawing

An embodiment of the invention is shown in the drawing and explained in more detail in the following description.

Description of the invention

An electromagnetic valve 1 is between a connection II as a pressure receiver and a connection I as a pressure source and a -;.! Terminal III arranged as a relief point 4. The pressure source is a pump 3> and the pressure receiver is a brake cylinder 2. A coil 5 sits on a coil carrier 6, and this in turn is pushed onto a jacket tube 7 which is connected to a non-magnetic ring 8, for example by welding. A magnetic circuit is made possible via a tube 9 ¹ .

The jacket pipe 7 with the ring 8 and a yoke 9 and an inlet valve seat 12 fastened in this are firmly connected to one another. This device accommodates an armature package, which essentially consists of a ring 11 and an armature 13. The ring 11 and the armature 13 are connected to one another via two leaf springs 16 and 17, for example by welding. The leaf springs 16 and 17 are made of an elastic, non-magnetic spring material. A spacer ring 18 is also located between the upper leaf spring 17 and an ^{end piece 10 having a seat I 1 I for the outlet valve.}

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In the armature 13 there is a multiple offset, continuous bore 19 into which the closing body 20/22 of the inlet valve 12, 20/22 and) 21/23 of the outlet valve 10 ', 21/23 are used.

The two closing bodies 20/22 and 21/23 are provided with balls 20, 21 which are each embedded in a ball holder 22 and 23 and are attached there. The ball holder 22 of the inlet valve closing body 20/22 is usually on one Shoulder 24 of the hole 19. This is the closing body 20/22 lifted from the valve seat 12, the inlet valve 12, 20/22 is open. One on the inlet valve closing body 20/22 acting spring 25 is supported on a ring 26, which is in the armature 13 with the help of another ring as Shoulder 27 is attached. The shoulder 27 has a recess, whereby between this and the ring 26 an axial Gap 28 is formed, .der receives the ball holder 23. the Ball holder 22 and 23 ^ mTt axial openings 22 'and 23' provided for the passage of pressure medium. A valve spring 35 of the outlet valve 14, 21/23 is within the spring 25 and rests with its one end on the ball holder 23 and with its other end on the ball holder 22.

For receiving the leaf springs 16 and 17, the armature has a recess 30 at one end and at his Pole face 13 ′ is provided with a recess 31. The recess 31 on the pole face 13 'is in the form of an annular disk Pole shoe 32 covered so that an uninterrupted, full area is again produced as the pole face of the armature 13 is.

In the yoke 9 an annular recess 33 is provided on which an intermediate disk 3 ^ is placed. There is one Ring wall 35 of the recess 33 an outer edge 36 of the PoI

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shoe opposite, and in this area a magnetic shunt is established.

A spring 37 is arranged under the armature 13 which, together with the restoring force-applying leaf springs 16 and 17, strives to push the armature 13 together with the pole piece 32 upwards, so that when the magnet is de-energized, the outlet valve 14, 21/23 is closed and the inlet valve 12 , 20/22 is open. This spring is inserted into a recess 38 in the pole piece 32. On the other side of the pole shoe 32, a cylindrical extension 39 is formed, the outer diameter of which corresponds ^{approximately to the inner diameter of an armature recess 13 'f.}

Mode of action

In the de-energized starting position of the device, the pressure receiver 2 is connected to the pressure source 3 through the hollow armature 13 and through the openings 22 'and 23 * in the ball holders ^?}. If the coil 5 is energized at the height of a first current level, the armature 13 is pulled downwards, the spring springs 16 and 17 deforming elastically together with the spring 37. In addition, the spring 35 stretches so that the closing body 21/23 of the outlet valve 1 * 1, 21/23 remains on its seat 1Ί until the closing body 20JZZ

of the inlet valve 12, 20/22 has reached its seat 12 and then the inlet valve 12, 20/22 is closed.

With a further stroke of the armature 13 through increased power supply, the outlet valve closing body 21/23 is lifted from its seat lh by the ring 27 and the outlet valve 1Ί, 21/23 is thus opened. The pressure medium in the pressure receiver 2 can now relax towards the relief point 4.

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When the armature 13 moves, it is not subject to any friction, since it is frictionless due to the leaf springs 16 and 17 is stored. The magnetic shunt between the recess 33 and the edge 36 of the pole piece 32 is achieves that the force-displacement characteristics run almost horizontally. Due to the enlarged pole surface, the Switching the valve required number of AWs can be reduced.

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Claims (4)

2711U0 February 25, 1977 He / Hm ROBERT BOSCH GMBH, 7OOO STUTTGART 1 Expectations (1. J Electromagnetically actuable valve, the movable valve members are carried by an armature which is urged by a spring in an electroless initial position and under the action of the magnetic force in the direction of a counterpart, motion-free with guiding and centering of the armature by means of leaf springs for its Receiving the armature is provided with recesses on its end faces, characterized in that the armature (13) is provided on the ^{end face having its pole face (13 1} ) with an annular disc-shaped pole shoe (32) which bridges the armature recesses (31). 809839/0040 2711U0 • a- 2. Valve according to claim 1, with a device sum magnetic shunt between armature and housing, characterized in that an outer edge (36) of the pole piece (32) forms a path for the magnetic shunt. 3. Valve according to claim 1 or 2, characterized in that that the annular disc-shaped pole piece (32) on its inner ring area has a cylindrical extension (39) which on its side facing the armature (13) an outer diameter corresponding to an armature recess (13 ") and on the other side of the pole piece (32) a recess (38) for partially receiving the armature spring (37) has. 4. Valve according to one of claims 1 to 3, characterized characterized in that the electromagnetically actuated valve is a 3-way valve which is positioned between a pressure receiver on the one hand and a pressure source and a (1) Relief point is arranged on the other hand, and that the (/ 3Y Armature accommodates two Schllcjßkorper (20 / 22Z.M / 23 ) movable against one another and with respect to the armature (13), which are pushed apart by an expanding spring (35) arranged in the armature (19). 809839/0040