WO2012101148A1

WO2012101148A1 - Solenoid valve

Info

Publication number: WO2012101148A1
Application number: PCT/EP2012/051093
Authority: WO
Inventors: Dierk Hein
Original assignee: Continental Teves Ag & Co. Ohg
Priority date: 2011-01-26
Filing date: 2012-01-25
Publication date: 2012-08-02
Also published as: DE102011003169A1; EP2668656A1

Abstract

A solenoid valve (1) having a toroidal field coil (3), which is arranged in a pot-like magnet yoke (2), and a magnet armature (4) which is mounted such that it can move in relation to the magnet yoke and which is in the form of an actuator of a valve and, when the field coil is switched on, is moved against a spring in the direction of the magnet yoke, wherein the magnet yoke has, in its base region, a first body (5) which projects into the hollow space in the toroidal field coil, the magnet armature is in the form of a cover for the pot-like magnet yoke and closes said magnet yoke so as to form a first gap (6) with a first gap spacing, the magnet armature has a second body (7) which projects into the hollow space in the toroidal field coil and which is at a second gap spacing from the first body so as to form a second gap (8), wherein the first gap and the second gap are arranged in the form of an axial gap such that the magnetic flux is substantially parallel to the axis (10) of the solenoid valve.

Description

magnetic valve

The invention relates to a solenoid valve having a arranged in a magnetic yoke exciter coil and a magnet armature movably mounted to the magnetic armature, which is designed as an actuator of a valve and is moved when switching the excitation coil against a magnet armature and magnetic yoke at a distance holding spring to the yoke. Furthermore, the invention relates to an air spring device and a hydraulic damper for a motor vehicle with such a solenoid valve.

Solenoid valves, i. Electromagnetically actuated switchable flow valves are often used for controlling flow processes in all kinds of fluids switching elements. In this case, when the current for an exciting coil in a magnetic core or magnetic yoke is induced by induction, a magnetic field and a magnetic flux is generated, which moves the armature and causes by this movement, the closing or opening of a flow valve.

Such solenoid valves are used for example in air spring systems or

Level control systems for motor vehicles. Air suspension systems or level control systems serve as particularly comfortable suspension systems and ensure a pleasant ride Driving feeling in a suspension, which can be adjusted depending on the road conditions between a "soft" and "hard" suspension behavior.

An air spring system or level control system consists of the air spring and damper units comprehensive air spring struts for each wheel or at least for each axis, from the air supply system with a compressor, a memory, a regenerable dryer and has this to an electronic control usually, wherein be opened or closed via switchable pneumatic controls in the form of solenoid valves connections between work rooms or chambers, storage, compressors or working volumes.

The air struts, also called "air springs", which are clamped between the chassis and body, have an air spring bellows, which in turn is fastened between a usually body-side air spring cover and a chassis-side rolling piston Such air springs knows the expert in a variety of designs The air spring bellows rolls under load and during spring movements to form a rolled fold on the outer contour of a concentric component, usually on the

Air spring piston / rolling piston. Such air spring is often used in road or rail vehicles to achieve a comfortable suspension.

The valves / solenoid valves used here usually consist of at least the valve piston or body and of the valve spring. Simple throttle valves may consist of only narrowed cross sections, gaps, overflow edges, etc., in a known manner, of course, valves having a corresponding throttling action also comprising valve piston, valve spring and valve housing.

The US 3,157,831 shows an AC solenoid valve for actuating a valve piston with a laminated, ie composed of individual assembled metal yoke, which has three yoke legs connected to a bridge, and from an associated with the valve piston armature or actuator, the is formed complementary to the magnetic yoke and is arranged with a gap distance to the latter. The magnetic yoke is M-shaped as a flat laminated body and the anchor formed in just this way T-shaped. In the magnetic yoke, the exciter coil is arranged so that both magnet yoke and magnet armature dive into the coil or surround the coil. Although the solenoid valve has a high magnetic force, also prevents jamming of the actuator, but its dimensions are quite large and therefore not suitable for example air spring systems.

Solenoid valves in air spring systems should namely on the one hand be as small and light and on the other hand can muster the largest possible forces when lifting. In addition, it is desired to increase the magnetic force characteristic, i. to influence the relationship between magnetic force and stroke in cooperation with the return spring and to be able to adapt constructively precisely to the application in order to ensure the necessary adjustment of the system behavior.

To this end, pot magnets are often used in the prior art, which have several air gaps in the magnetic circuit, namely in addition to the axial air gap, through which the actual force is applied in the axial direction of the magnet by the magnetic field strength or the magnetic flux, also noteworthy radial air gaps between Anchor and yoke. In the radial air gaps magnetic flux magnetic forces are generated, which act substantially perpendicular to the axis of the yoke and thus the solenoid valve and thus perpendicular to the direction of movement of the armature.

These magnetic forces contribute nothing to the actual task of the solenoid valve and must be compensated by additional magnetic excitation, that is, of course, with a constant number of coil windings by a stronger coil current. Thus, in these types of solenoid valves in the prior art, either the power consumption is increased or the magnetic force is lowered. Although the characteristic curve can also be influenced with regard to the resulting force, here only a shift of the maximum magnetic force to the beginning of the stroke and a concomitant reduction towards the end of the stroke occur. The object of the invention, therefore, was to provide a small-sized pot magnet, inter alia, for use in air spring systems, which generates large lifting force, low magnetic power loss and an improvement of the magnetic efficiency allows and influencing the magnetic force characteristic, ie the relationship between magnetic force and stroke in cooperation with the return spring allowed.

This object is achieved by the features of the main claim. Further advantageous embodiments are disclosed in the subclaims.

In this case, the solenoid valve according to the invention comprises an exciter coil, which is toroidal and a magnetic yoke that surrounds the excitation coil cup-shaped, wherein the cup-shaped yoke has in its bottom portion in the cavity of the toroidal excitation coil projecting first body, the armature as a lid for the cup-shaped magnetic yoke is formed and the latter closes to form a first gap with a first gap spacing, wherein the magnet armature also in the

Having cavity of the toroidal excitation coil projecting second body, which has a second gap to the first body to form a second gap and wherein first and second gaps are arranged as axial gaps so that the magnetic flux is formed substantially parallel to the axis of the solenoid valve.

Thus, apart from the required sliding fits, there are no or hardly any magnetically effective radial air gaps and hardly any magnetic power loss. An improvement in the magnetic efficiency is made possible in particular by the fact that in the radially not or only minimally formed columns of the magnetic flux to

Orders of magnitude smaller and less resistant than in the case of the broadly trained

Columns that are common in the art.

Thus, the usual existing transition of the magnetic flux to the armature via a radial air gap constructively placed in an axial gap, so that the magnetic flux is formed substantially parallel to the axis of the solenoid valve and Thus, the magnetic force is introduced substantially unrestricted in the direction of movement of the armature. The solenoid valve can thus be made small and lightweight in all components, especially with regard to the number of turns and the

Wire diameter of the Torusspule, which then no longer has to be designed for a stronger coil current for compensation.

An advantageous development is that the solenoid valve is cylindrical and the cup-shaped magnetic yoke are designed as a rotationally symmetrical hollow cylinder, the first and the second body as a rotationally symmetric cylinder and the armature as a round and rotationally symmetrical lid. In addition to others, z. B. oval or eccentric shapes of the solenoid valve, the round rotationally symmetrical shape of the components is particularly suitable because the corresponding receptacles in the facilities in which the solenoid valve according to the invention is to be used, are to be formed only as tolerated holes.

A further advantageous embodiment is that the magnet armature is designed in several parts, that is usually in two parts, and essentially has a cover plate and a second body connected to the cover plate and protruding into the cavity of the toroidal exciter coil. Cover plate and second body can be connected to one another in a material-locking or form-fitting manner. This results in a production method adapted to the individual application. For small magnets is quite an adhesive method applicable here

A further advantageous embodiment is that the cup-shaped yoke is formed in several parts and essentially a bottom plate, one with the

Bottom plate connected, in the cavity of the toroidal exciter coil

projecting first body and one connected to the bottom plate and the

Exciter coil surrounding pot housing identifies. Again, with the advantages already mentioned, the individual parts can be connected to each other in a material-locking or form-fitting manner. A further advantageous embodiment is that the magnet armature is designed as a valve body which cooperates with a valve seat for closing and opening the solenoid valve, so magnet armature and valve body are integrally formed. This achieves a partial reduction with regard to the overall valve structure.

A further advantageous embodiment consists in that the spring is arranged between the magnet armature formed as a lid and the cup-shaped yoke in the region of the first gap. Thus, the magnetic flux is not or only imperceptibly influenced by the spring. The same applies to a further advantageous embodiment, which consists in that in the region of the first gap between the magnet armature designed as a lid and the cup-shaped yoke, a stop buffer is arranged.

A further advantageous embodiment is that magnetic yoke and / or

Magnetic armature consist of turned parts. Turned parts are particularly tight

Produce tolerances so that radial air gaps actually no longer exist or are no longer noticeable by losses.

A further advantageous application of the solenoid valve according to the invention is that the solenoid valve is Gleichstromerregt and is arranged in an air spring device for a motor vehicle or in a hydraulic damper for a motor vehicle.

Reference to an embodiment of the invention will be explained in more detail. 1 shows a solenoid valve according to the invention,

2 shows a further embodiment of a solenoid valve according to the invention with a possibility for adapting the magnetic characteristic,

3 shows the force characteristics of a solenoid valve according to FIG. 2.

1 shows an inventive solenoid valve 1 with a in a

Magnetic yoke 2 arranged excitation coil 3 and a movable to the magnetic yoke. 2 mounted magnet armature 4, which is designed as an actuator of a valve and when switching the excitation coil 3 against a magnet armature 4 and magnetic yoke 2 spaced retaining retaining spring to the yoke 2 is moved towards. The exciter coil 3 of the solenoid valve 1 is toroidal and the magnetic yoke 2 surrounds the exciter coil cup-shaped.

The cup-shaped magnetic yoke 2 has in its bottom region a projecting into the cavity of the toroidal exciter coil 3 first body 5.

The armature 4 is formed as a cover for the cup-shaped yoke 2 and closes the latter to form a first gap 6 with a first gap distance.

The magnet armature 4, similarly to the yoke, has a second body 7 projecting into the cavity of the toroidal exciter coil 3 and having a second gap spacing with respect to the first body 5 to form a second gap 8.

First and second gap 6 and 8 are arranged as axial gaps so that the magnetic flux 9, which is shown here for simplicity only on the right side of Fig. 1, formed substantially parallel to the axis 10 of the solenoid valve.

The same magnetic flux 9 is naturally toroidally formed around the exciting coil.

The solenoid valve is cylindrical here. Accordingly, the cup-shaped magnetic yoke 2 are designed as a rotationally symmetrical hollow cylinder, the first and the second body 5 and 7 as a rotationally symmetric cylinder and the magnet armature 4 as a round and rotationally symmetrical lid.

The armature 4 is formed in two parts and has a cover plate 11 and connected to the cover plate in the cavity of the toroidal excitation coil projecting second body 7. Both parts form fit over here not closer shown screwed together.

A restoring spring not shown here is in the dash-dotted framed area 12 between the magnet armature 4 designed as a lid and the cup-shaped

Magnetic yoke 2 arranged in the region of the first gap.

A particularly advantageous embodiment is shown in FIG. 2, in which the projecting into the cavity of the toroidal excitation coil 3 first body 5 and protruding into the cavity of the toroidal exciter coil 3 second body 7 at their facing surfaces in the region of the second gap 8 with each other complementary projections and recesses are formed. With such a design, characteristic influencing can be achieved, i. a precise adaptation of the magnetic characteristic to the valve characteristic.

In the present embodiment, the first body 5 has a concentric and surrounding by a protruding outer edge recess 15, while the second body 7 has a concentric and complementary to the recess 15 cylindrical projection 16.

The thus possible adaptation of the magnetic characteristic is shown in FIG. 3, in which, for the embodiment according to FIG. 2, the magnetic force is plotted over the stroke, i. the

Force characteristics of the single air column and the solenoid valve according to the invention with the two air gaps in total. In this case, the magnetic force generated by the gap 8 is represented by the curve 17 and the magnetic force generated by the gap 6 through the curve 18. Summarized and superimposed results then a force influencing the stroke, as shown by the curve 19. The magnetic force is changed so that it reaches a high value at the beginning of the stroke, then drops only slightly over the stroke and only at the stroke end, a significant drop in the magnetic force is achieved. LIST OF REFERENCE NUMBERS

(Part of the description)

1 solenoid valve

2 magnetic yoke

3 exciter coil

4 magnetic armature

5 First body (belonging to the yoke)

6 First gap

7 Second body (belonging to the anchor)

8 second gap

9 Magnetic flow

10 axis of the solenoid valve

11 cover plate

12 Installation location / area of the return spring

13 bottom plate of the magnetic yoke

14 pot housing of the magnetic yoke

15 concentric well

16 Cylindrical projection

17 force characteristic of the magnetic force generated by the gap 8

18 force characteristic of the magnetic force generated by the gap 6

19 Total force characteristic over the stroke

Claims

claims

1. Solenoid valve (1) having a in a yoke (2) arranged exciter coil (3) and a magnet to the magnet yoke mounted magnet armature (4), which is designed as an actuator of a valve and upon activation of the exciter coil (3) against a magnet armature (4 ) and magnetic yoke (2) on distance holding spring to the magnetic yoke (2) is moved, characterized in that

- The excitation coil (3) is toroidal and the magnetic yoke (2) surrounds the exciter coil pot-shaped,

- The cup-shaped magnetic yoke (2) in its bottom portion one in the

Having cavity of the toroidal exciter coil (3) protruding first body (5),

- The armature (4) as a lid for the cup-shaped yoke (2)

is formed and the latter closes with formation of a first gap (6) with a first gap spacing,

- The magnet armature (4) has a protruding into the cavity of the toroidal exciter coil second body (7) to the first body to form a second gap (8) has a second gap spacing, wherein the first and second gap (6, 8) as axial gaps are arranged so that the magnetic flux (9) in the columns (6, 8) is formed substantially parallel to the axis (10) of the solenoid valve.

2. Solenoid valve according to claim 1, which is cylindrical and in which the cup-shaped yoke (2) as a rotationally symmetrical hollow cylinder, the first and the second body (5, 7) as a rotationally symmetrical cylinder and the

Magnetic armature (4) are designed as a round and rotationally symmetrical lid.

3. Solenoid valve according to claim 1 or 2, wherein the magnet armature (4) is designed in several parts and essentially a cover plate (11) and one connected to the cover plate in the cavity of the toroidal exciter coil (3). having projecting second body (7).

4. Solenoid valve according to one of claims 1 to 3, wherein the cup-shaped

Magnetic yoke (2) is formed in several parts and substantially a bottom plate (13), one connected to the bottom plate (13), in the cavity of

Toroidal excitation coil (3) protruding first body (5) and one with the bottom plate (13) connected and the exciter coil surrounding pot housing (14) identifies.

5. Solenoid valve according to one of claims 1 to 4, wherein the magnet armature is designed as a valve body which cooperates with a valve seat for closing and opening the solenoid valve.

6. Solenoid valve according to one of claims 1 to 5, wherein the spring between the magnet armature formed as a cover (4) and the cup-shaped yoke (2) in the region of the first gap (6) is arranged.

7. Solenoid valve according to one of claims 1 to 6, wherein in the region of the first gap (6) between the magnet armature designed as a cover (4) and the cup-shaped yoke (2), a stop buffer is arranged.

8. Solenoid valve according to one of claims 2 to 7, wherein the yoke (2) and / or armature (4) consist of turned parts.

9. A solenoid valve according to any one of claims 2 to 8, wherein in the cavity of the toroidal exciter coil (3) projecting first body (5) and in the cavity of the toroidal excitation coil (3) projecting second body (7) facing towards each other Areas in the region of the second gap (8) with mutually complementary projections and depressions for

Characteristic influencing are formed.

10. Solenoid valve according to claim 10, wherein the first body (5) has a concentric and by a projecting outer edge surrounding recess (15) and the second body (7) has a recess (15) complementary cylindrical projection (16).

11. Air spring device for a motor vehicle with at least one

Gleichstromerregten solenoid valve according to claim 1 to 10.

12. Hydraulic damper for a motor vehicle with at least one

Gleichstromerregten solenoid valve according to claim 1 to 10.