EP2601084A1

EP2601084A1 - Magnet valve, and driver assistance device comprising such a magnet valve

Info

Publication number: EP2601084A1
Application number: EP11726119.8A
Authority: EP
Inventors: Klaus-Dieter Fietz; Volker Unsoeld; Manfred Maerz; Valentin Schubitschew; Scott Ducworth
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2010-08-04
Filing date: 2011-06-10
Publication date: 2013-06-12
Also published as: US20130306891A1; WO2012016741A1; KR20130095729A; CN103052547A; DE102010038900A1

Abstract

The invention relates to a magnet valve (1) comprising a magnet armature (2) that is operatively connected to a sealing element (3) of the magnet valve (1) in order to displace said element and comprising at least one flow path (18) via which fluid chambers (16, 17) that lie on opposing faces of the magnet armature (2) can be connected or are connected in a fluidic manner. At least one damping element (19) is arranged in the magnet valve (1) in a displaceable manner in the axial direction, said damping element protruding into the flow path (18) at least in some regions.

Description

description

title

SOLENOID VALVE AND DRIVER ASSISTANT DEVICE WITH SUCH A SOLENOID VALVE

State of the art

The invention relates to a solenoid valve having a magnet armature, which is operatively connected to a sealing element of the solenoid valve for its displacement, and at least one flow path, via which fluid chambers arranged on opposite sides of the magnet armature are fluid-connectable or fluid-connected. The invention further relates to a driver assistance device.

Solenoid valves of the type mentioned are known from the prior art. They are usually used for driver assistance devices, in particular ABS, TCS or ESP devices. The solenoid valve has the armature, which, in particular axially, is arranged displaceably in the solenoid valve. The armature is operatively connected to the sealing element of the solenoid valve, so that when a shift of the armature and the

Relocated sealing element. The sealing element is usually provided to close or release a valve opening of the solenoid valve. If the sealing element is arranged to close the valve opening, it usually sits in a valve seat of the solenoid valve, which is associated with both the valve opening and the sealing element. For example, the sealing element is introduced into a recess of the magnet armature and held therein, wherein the recess is preferably provided on a side facing away from the armature counterpart end face of the magnet armature.

Usually, the solenoid valve has an actuating device, which is formed by the armature together with an armature counterpart. In addition to the armature, the solenoid valve thus also has the armature counterpart. This is designed for example as a pole core. The pole core is usually referred to lent a housing of the solenoid valve held stationary while the armature is displaceable relative to the housing. To effect this displacement, the armature and armature counterpart cooperate. In this case, the armature counterpart, for example, one or more coils, while the armature consists of a magnetizable or magnetic material.

The armature counterpart is provided on the front side of the magnet armature. Usually, the armature and the armature counterpart are arranged to each other such that they, regardless of the displacement of the armature, can not communicate with each other. Accordingly, there is a gap, the so-called air gap or working air gap, between the magnet armature and the armature counterpart or the end face of the armature facing the armature counterpart and the armature counterpart facing the armature armature. The size of the air gap is dependent on the position of the armature with respect to the armature counterpart. The size of the air gap changes accordingly when the armature is displaced.

On opposite sides of the armature, the fluid chambers are present, wherein the air gap is at least partially formed by one of the fluid chambers. The fluid chamber volume of the fluid chambers is dependent on the position of the armature with respect to the armature counterpart. In order to avoid a strong pressure build-up or pressure drop in one of the fluid chambers or in the fluid chambers during a displacement of the magnet armature, the fluid chambers can be fluidly connected to one another or fluid-connected via the flow path. This means that with a displacement of the magnet armature fluid from that fluid chamber, in the direction of the

Magnetic armature is displaced, in the displacement of the opposite fluid chamber is urged. In conventional embodiments of the solenoid valve, the flow path is formed by the armature itself. For example, the flow path between the magnet armature and the housing of the magnetic valve, in which the armature is guided axially movable, before. The flow path is therefore defined by an outer contour of the magnet armature and an inner contour of the housing. With a displacement of the armature, it may well happen that the fluid chamber volume of one of the fluid chambers is reduced to zero; in this case, therefore, the fluid chamber is present only in a figurative sense. During its displacement, the magnet armature of the solenoid valve moves at a certain speed. The greater this speed, the stronger pressure waves are generated when the sealing element hits the valve seat. These pressure waves are converted into sound when they occur on a wall, so that the operation of the solenoid valve causes unwanted noise. Generally speaking, the higher the speed at which the magnet armature is displaced, the louder these noises become. To counteract this problem, it is known to increase the damping of the solenoid valve, for example, by reducing the flow area of the flow path. In this way, the speed at which the armature is displaced, reduced. However, this has the consequence that the maximum achievable actuating speed of the solenoid valve is reduced, so the minimum achievable positioning time of the solenoid valve is increased. Thus, when designing a solenoid valve, there are two opposing optimization goals to choose from. On the one hand, the generation of pressure waves or sound can be reduced by the solenoid valve, on the other hand, the actuating speed can be increased.

Disclosure of the invention

In contrast, the solenoid valve with the features mentioned in claim 1 has the advantage that it works both low-vibration and low noise and at the same time allows a high actuating speed. This is inventively achieved by at least one in the flow path at least partially projecting damping element is arranged to be displaceable in the axial direction in the solenoid valve. The damping element can increase the damping of the magnetic valve or of the magnet armature by reducing the flow cross-section of the flow path or increasing the effective cross-section of the armature located in the flow path. This is achieved by the - usually the

Magnetic armature associated - damper element at least partially protrudes into the flow path. The damping element should, in particular with respect to the armature, be displaced in the axial direction. It is thus displaceable at least between a first and a second position. The damping element can be attached to the magnet armature or to another element bounding the flow path, for example the housing of the magnet valve. orders be. Advantageously, the damping element projects beyond the outer contour of the magnet armature in the radial direction. In an alternative embodiment, however, it could also be provided that the flow path, via which the fluid chambers are fluid-connectable, is produced by means of a recess or an opening of the magnet armature. In this case, the damping element may also be arranged in a damping element chamber of the magnet armature.

The damping element is in particular arranged so displaceable in the axial direction that the damping of the solenoid valve only in at least one

Position is increased, while in at least one other position, the damping is unchanged. It is advantageously provided that the damping of the solenoid valve is increased in a closing operation of the solenoid valve, just before the sealing element comes into contact with the seal seat. In this way, the speed of the armature is only in one

Reduced position range, which is selected such that a low-noise closing of the solenoid valve is made possible. The damping element is therefore intended to reduce the flow area of the flow path only in a first position range of the armature and thus to increase the damping of the solenoid valve in this. In contrast, in a second position range, which is different from the first position range, the flow cross-section of the flow path and thus the damping of the solenoid valve remain unchanged. In the first position range, therefore, the displacement of the armature is delayed, so that it moves in this at a lower speed. In the second position range, however, a movement of the armature is allowed at a higher speed. Thus, in comparison with solenoid valves known from the prior art, a quieter closing is achieved without, however, significantly reducing the (average) speed of the magnet armature. Only in the first position range, which represents only a (small) area of the entire travel between open position - the valve seat is released from the sealing element - and closed position - the valve seat is closed by the sealing element - represents the armature, is a reduction in the speed of Magnetic armature instead, so that the actuating speed of the solenoid valve remains virtually unchanged. A development of the invention provides that the damping element can be displaced in the axial direction along the flow path by a fluid flow caused by a movement of the magnet armature. As already stated above, the movement or displacement of the magnet armature causes the fluid flow along the flow path, with the fluid flowing from one of the fluid chambers into the other of the fluid chambers or vice versa. By the intrusion of the damping element into the flow path, the fluid flow along the flow path causes a force on the damping element. This actuating force causes the displacement of the damping element in the axial direction. For this reason, it is usually provided that the damping element is mounted such that it can be easily displaced from the fluid flow. In particular, no additional adjusting means for displacing the damping element are provided or necessary.

A development of the invention provides that the magnet armature has at least one end stop for limiting an axial displacement of the damping element. The axial displacement of the damping element takes place relative to the armature. If the damping element reaches the position of the end stop, this prevents further displacement of the damping element with respect to the magnet armature. The end stop sets the damping element so far in at least one axial direction, as soon as it has reached a certain position with respect to the armature. If the magnet armature is subsequently displaced counter to this axial direction, the damping element is entrained by the magnet armature via the end stop. In this way, the effective cross section of the magnet armature is increased by the damping element or the flow cross section of the flow path is reduced and thus increases the damping of the solenoid valve.

A development of the invention provides that the damping element is mounted in a groove of the magnet armature. The groove may be partially formed on the armature or only in one or more peripheral regions. The damping element sits in such a way in the groove that it is mounted with respect to the magnet armature. The groove may, for example, the at least one

End stop, preferably two opposite end stops form. A further development of the invention provides that the groove of the magnet armature is present between partial elements of the magnet armature. The armature is thus a multi-part, in particular two parts, formed. Such a configuration of the solenoid valve or the magnet armature allows a simple

Assembly of the damping element to the armature. In particular, the damping element is assembled with a first of the sub-elements and then at least one further of the sub-elements is mounted on the first of the sub-elements. Subsequently, the damping element sits in the groove of the magnet armature and is held captive in this. Only disassembly of the sub-elements from each other allows removal of the damping element from the groove.

A development of the invention provides that one of the sub-elements at least partially, in particular clamping, engages in another of the sub-elements. For attachment of the sub-elements to each other, it is therefore intended that these interlock. This way, a positive or positive fastening to each other can be realized. Particularly advantageously, the sub-elements engage one another in such a way that a clamping connection is realized. Alternatively, however, could also be provided, for example, a screw connection between the sub-elements.

A development of the invention provides that the damping element, the magnet armature at least partially, in particular completely encompasses. The damping element is therefore provided on an outer contour of the magnet armature. The gripping is at least partially provided, so that the damping element projects into at least one peripheral region of the flow path. It is particularly advantageous if the damping element completely engages around the magnet armature, so that-viewed in cross-section-the entire flow path can be acted upon by the damping element.

A development of the invention provides that the damping element has larger dimensions in the radial direction than the magnet armature. Accordingly, the damping element projects in the radial direction via the magnetic armature such that it projects further into the flow path than the magnet armature. In this way, the damping element can increase the damping of the solenoid valve in the first position range of the armature.

A development of the invention provides that the magnet armature has a radial bearing for the damping element. The radial bearing guides the damping element in the axial direction and prevents movement in the radial direction. Ideally, the radial bearing and the damping element are designed such that a tilting of the damping element is prevented with respect to the armature.

The invention further relates to a driver assistance device, in particular ABS, TCS or ESP device, with at least one solenoid valve, in particular according to the preceding embodiments, wherein the solenoid valve, a magnet armature, which is operatively connected to a sealing element of the solenoid valve to its displacement, and at least one Flow path, via which arranged on opposite sides of the magnet armature fluid chambers are fluid-connectable or fluid-connected has. It is provided that in the solenoid valve at least one at least partially projecting into the flow path damping element is arranged to be displaceable in the axial direction. The solenoid valve of the driver assistance device can be developed further in accordance with the above explanations.

The invention will be explained in more detail with reference to the embodiments illustrated in the drawings, without any limitation of the invention. Showing:

1 shows a side sectional view of a solenoid valve with a magnetic armature, which is associated with a damping element,

2 shows the armature and the damping element,

FIG. 3 shows the damping element in a first position,

Figure 4 shows the damping element in a second position, and Figure 5 is a diagram in which an attenuation of the solenoid valve is shown via a travel of the armature.

The figure shows a solenoid valve 1, which is for example part of a Fahrerassistzeinrichtung not shown here. The solenoid valve 1 has a magnet armature 2, which is operatively connected to a sealing element 3 of the solenoid valve 1. The seal member 3 cooperates with a valve seat 5 formed in a valve body 4 to release or interrupt a flow communication between an inlet port 6 and an outlet port 7 of the solenoid valve 1. The outlet port 7 is associated with a filter 8 in the embodiment shown here. Additionally or alternatively, it is of course also possible for a filter to be assigned to the inlet connection 6 (not shown here). The solenoid valve 1 shown here is designed according to the arrangement of inlet port 6 and outlet port 7 for an axial flow and a radial outflow (with respect to a longitudinal axis 9 of the solenoid valve 1). Of course, however, the direction of flow or the outflow direction can be arbitrarily provided. In addition to the essentially a circular cross-section having armature 2, the solenoid valve 1 has an armature counterpart 10, which forms an actuating device 1 1 of the solenoid valve 1 together with the armature 2. The armature counterpart 10 is formed for example as a pole step and has at least one electric coil, so that by means of the anchor counterpart 10 by applying a voltage to the coil (ie by

Energization of the solenoid valve 1) a magnetic force can be exerted on the armature 2. The armature 2 is mounted axially displaceable with respect to the longitudinal axis 9, wherein the storage is realized in particular by means of a housing 12 of the solenoid valve 1. On the housing 12, the anchor counterpart 10 and the valve body 4 are also held stationary. Thus, the armature 2, influenced by the magnetic force generated by means of the armature counterpart 10, relative to the armature 2 and the valve body 4 are displaced in the axial direction. The solenoid valve 1, which is shown in the figure, is a normally closed solenoid valve 1. This means that the sealing element 3 uses sealing in the valve seat 5, as long as the solenoid valve 1 is not energized, so no magnetic force by means of the armature counterpart 10 is generated.

On the armature counterpart 10 facing away from the side of the magnet armature 2, the sealing element 3 is introduced in a stepped bore 13. In this case, the sealing element 3 is preferably pressed into the stepped bore 13, so that it is held in this clamping. In a further recess 14 of the magnet armature 2, a spring element 15 is arranged such that it comes into operative contact with both the magnet armature 2 and the armature counterpart 10. The spring element 15, which is designed here as a spiral spring, causes a force acting on the armature 2 spring force, wherein it is supported on the armature counterpart 10. The spring force urges the magnet armature 2 in the direction away from the armature counterpart 10 direction. If the solenoid valve 1 is energized, thus acting on the armature 2, the corresponding, in the embodiment shown here in the direction of the armature counterpart 10 directed magnetic force, the armature 2 is moved toward the armature counterpart 10. In this case, the spring element 15 (further) is stretched. If the magnetic force is omitted, the spring force causes the magnet armature 2 to be urged away again by the armature counterpart 10. On opposite sides of the armature 2 are fluid chambers 16 and

17 provided. In order to avoid pressure build-up or pressure drop in the fluid chambers 16 and 17 during a displacement of the magnet armature 2, and thus enable the magnet armature 2 to be easily adjusted, the fluid chambers 16 and 17 are connected to one another via a flow path 18. The flow path 18 is formed in the embodiment shown here between an outer contour of the magnet armature 2 and an inner contour of the housing 12. For this purpose, the magnet armature 2 at each axial position in the radial direction smaller dimensions than an interior of the housing 12 in which the armature 2 is guided.

In the figure 1, the armature 2 is shown in its closed position. To relocate it to its open position, the solenoid valve 1 is energized, so that by means of the armature counterpart 10, a magnetic force is generated, which moves the armature 2 in the direction of the armature counterpart 10. In this case, the valve seat 5 is released by the sealing element 3. If the valve seat 5 is to be closed again, then the solenoid valve 1 is deactivated, so that the magne- netkraft deleted and the spring force generated by the spring element 15, the armature 2 and thus the sealing element 3 in the direction of the valve seat 5 urges. The path traveled by the magnet armature 2 between its open position and its closed position or vice versa is referred to below as the actuating path.

In order to achieve the short positioning times required in many solenoid valves 1, the armature 2 must be displaced at a comparatively high speed. The positioning time is understood to mean the time required to move the armature 2 from its open position to the closed position or vice versa. Therefore occur, in particular when closing the valve seat 5 by the sealing element 3, so when moving the armature 2 in its closed position (as shown in Figure 1), pressure waves, which can cause disturbing noises. Magnetic valves 1 have therefore been proposed, which have a higher damping, so that the magnet armature 2 is displaced more slowly. The higher damping is achieved by a smaller flow cross section of the flow path 18. In this way, the solenoid valve 1 can be operated quietly. However, this measure also requires a longer positioning time of the solenoid valve. 1

In order to enable a low-noise operation of the solenoid valve 1 with short positioning times, a damping element 19 is provided, which projects into the flow path 18 between the fluid chambers 16 and 17 at least partially. The damping element 19 is mounted in a groove 20 of the armature 2, wherein the groove 20 in the axial direction has a greater width than the damping element 19. In this way, the damping element 19 in the axial direction can be displaced. In the embodiment shown here, the damping element 19 is accordingly assigned to the magnet armature 2. The damping element 18 is displaceable in the axial direction along the flow path 18 by a fluid flow caused by a movement of the magnet armature 2. The groove 20 forms two end stops 21 and 22 for the damping element 19. The end stops 21 and 22 limit the axial displacement of the damping element 19 with respect to the magnet armature 2.

FIG. 2 shows a detailed view of the magnet armature 2 and of the damping element 19. It becomes clear that the magnet armature 2 consists of two partial elements 23 and 24 exists. The groove 20 is present between the sub-elements 23 and 24. The sub-element 24 engages at least partially in the sub-element 23. In this way, a clamping connection between the sub-elements 23 and 24 is provided, so that the damping element 19 is held captive in the groove 20. In an assembly of the solenoid valve 1 is therefore initially the

Damping element 19 mounted on a central pin 25 of the sub-element 24 so that it preferably comes into contact with the end stop 22 or rests on this. Subsequently, the partial element 23 is pressed onto the journal 25 of the partial elements 24, so that a permanent connection between the partial elements 23 and 24 is produced. In the area of

Sub-element 23, the flow path 18 of radial projections 26, which emanate from the sub-elements 23 and the housing 12 oppose, divided. The partial element 24 has a radial projection 27, which is circumferentially formed in the circumferential direction. In this case, the radial projection 27 has a smaller radial extent than the radial projections 26 of the impact element 23. Starting from the radial projection 27, the cross section of the subelement 24 decreases in the direction of the sealing element 3 via a radial step. From the figure 2 it is clear that the damping element 19, the armature

2 completely encompasses in the circumferential direction. It can also be seen that it has larger dimensions in the radial direction than the armature 2 or its sub-elements 23 and 24. In the groove 20 is a radial bearing 28 for the damping element 19 before. This is formed by the magnet armature 2. The radial bearing 28 allows only an axial displacement of the damping element 19 with respect to the magnet armature 2, thus substantially prevents a movement of the damping element 19 in the radial direction or a tilting of the damping element 19. With reference to Figures 3 and 4 is on the operation of the damping element

19 and the damping element 19 having the solenoid valve 1 are received. FIG. 3 shows a region of the magnet armature 2, the magnet armature 2 being in its open position. The damping element 19 assumes, for example, the position shown in FIG. In this position, it is brought, for example, from restoring means, not shown here. These return means comprise, for example, at least a spring element, which acts between the armature 2 and the damping element 19, to urge the damping element 19 in the position shown in Figure 3. Preferably, at least one spring element is arranged in each case on both sides of the damping element 19 in the groove 20. Ideally, two spring elements are provided diametrically opposite each other. Preferably, four or more spring elements are used.

If the magnet armature 2 is displaced in the direction of its closed position in order to cover the valve seat 5 by means of the sealing element 3, then the through-flow cross section of the flow path 18 or the damping of the magnet valve 1 initially remains unchanged. Thus, in a second position range, a low damping or a high actuating speed of the magnet armature 2 is present. During the displacement of the magnet armature 2, fluid flows along the flow path 18 out of the fluid chamber 17 into the fluid chamber 16. This flow or fluid flow causes a

Actuating force on the damping element 19, which urges it in the direction of the end stop 21 of the magnet armature 2.

With sufficient further displacement of the magnet armature 2, the damping element 19 rests on the end stop 21. This is shown in FIG. It is readily apparent that the damping element 19, as soon as it bears against the end stop 21, is carried along by the magnet armature 2 in the direction of its closed position. The damping element 19 is thus displaced counter to the fluid flow along the flow path 18 together with the magnet armature 2. This causes a significant increase in the damping of the solenoid valve. 1 Thus, the displacement speed of the armature 2 is reduced.

The first position range contains insofar the positions of the magnet armature 2, for which the coupling element 19 rests against the end stop 21. The second

Position range, however, contains the positions of the armature 2, in which the damping element 19 is not yet applied to the end stop 21.

FIG. 5 shows a diagram in which the damping k of the solenoid valve 1 is shown via the travel x of the magnet armature 2. The damping is dimensionless, the travel of the armature 2 in millimeters indicated. One A travel of zero means that the armature 2 is in its open position, and a travel of x _g , that the armature 2 is in its closed position. .Das diagram of Figure 5 shows that the damping of the solenoid valve 1 in the first position range 29 is greater than in the second position range 30. It thus shows that the attenuation of the

Solenoid valve 1 only in a small position range - based on the total travel - is increased. In this way, a low-noise operation of the solenoid valve 1 is enabled at the same time high speed.

Claims

claims

1 . Solenoid valve (1) having a magnet armature (2) which is operatively connected to a sealing element (3) of the solenoid valve (1) for displacement thereof, and at least one flow path (18) via which fluid chambers (2) are arranged on opposite sides of the magnet armature (2). 16,17) are fluid-connectable or fluid-connected, characterized in that in the solenoid valve (1) at least one in the flow path (18) at least partially projecting damping element (19) is arranged to be displaceable in the axial direction.

2. Solenoid valve according to claim 1, characterized in that the damping element (19) of a by a movement of the armature (2) caused fluid flow along the flow path (18) is displaceable in the axial direction.

3. Solenoid valve according to one of the preceding claims, characterized in that the magnet armature (2) has at least one end stop (21, 22) for limiting an axial displacement of the damping element (19).

4. Solenoid valve according to one of the preceding claims, characterized in that the damping element (19) is mounted in a groove (20) of the magnet armature (2).

5. Solenoid valve according to one of the preceding claims, characterized in that the groove (20) of the armature (2) between sub-elements (23,24) of the armature (2) is present.

6. Solenoid valve according to one of the preceding claims, characterized in that one of the sub-elements (23,24) at least partially se, in particular clamping, engages in another of the sub-elements (24,23).

Solenoid valve according to one of the preceding claims, characterized in that the damping element (19), the magnet armature (2) at least partially, in particular completely surrounds.

Solenoid valve according to one of the preceding claims, characterized in that the damping element (19) has larger dimensions in the radial direction than the magnet armature (2).

Solenoid valve according to one of the preceding claims, characterized in that the magnet armature (2) has a radial bearing (28) for the damping element (19). Driver assistance device, in particular ABS, TCS or ESP device, with at least one solenoid valve (1), in particular according to one or more of the preceding claims, wherein the solenoid valve (1) comprises a magnet armature (2) provided with a sealing element (3) of Solenoid valve (1) is operatively connected to the displacement, and at least one flow path (18) via which on opposite sides of the magnet armature (2) arranged fluid chambers (16,17) are fluid-connected or fluid-connected, characterized in that in the Solenoid valve (1) at least one in the flow path (18) at least partially projecting damping element (19) is arranged to be displaceable in the axial direction.