EP3658430A1

EP3658430A1 - Bistable solenoid valve for a hydraulic brake system, activation method and assembly method for the same, and brake system having a solenoid valve of said type

Info

Publication number: EP3658430A1
Application number: EP18731049.5A
Authority: EP
Inventors: Massimiliano Ambrosi; Edgar Kurz; Wolf Stahr; Wolfgang Schuller; Klaus Landesfeind; Michael Eisenlauer
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2017-07-26
Filing date: 2018-06-11
Publication date: 2020-06-03
Also published as: JP2020527681A; DE102017212820A1; JP6934557B2; CN110958964A; WO2019020260A1; US11351973B2; US20200262410A1

Abstract

The present invention relates to a bistable solenoid valve (1) for a hydraulic brake system, having a guide sleeve (2) in which an upper immovable pole core (5) is arranged fixedly and a closing element (3) is arranged displaceably, wherein the closing element (3) is forced into a valve seat (4) during a closing movement and lifts off from the valve seat (4) during an opening movement, and the closing element (3) is fixedly connected to a magnet assembly (8), wherein an actuation of the movement of the closing element (3) is performed by means of the magnet assembly (8) by way of a coil (7) which is positioned around and substantially surrounds the guide sleeve (2), and wherein, furthermore, a lower immovable pole core (6) is arranged fixedly in the guide sleeve (2), and the magnet assembly (8) is positioned between the lower and the upper pole core (6, 5). The present invention furthermore relates to a method for controlling the solenoid valve (1) according to the invention, to a method for assembling the solenoid valve (1) according to the invention, and to a hydraulic brake system having the solenoid valve (1) according to the invention.

Description

description

title

BISTABLE SOLENOID VALVE FOR A HYDRAULIC BRAKING SYSTEM, CONTROL METHOD AND ASSEMBLING METHOD THEREFOR, AND BRAKING SYSTEM WITH SUCH A SOLENOID VALVE The present invention relates to a bistable solenoid valve for a hydraulic

Brake system, with a guide sleeve in which an upper stationary pole core fixed and a closing element is arranged to be displaceable, wherein the closing element during a closing movement in a valve seat urges and during a

Opening movement from the valve seat lifts and the closing element is firmly connected to a magnet assembly is an actuation of the movement of the

Closing element by means of the magnet assembly via a coil, which is positioned around the guide sleeve and this substantially comprises, wherein the

Solenoid valve is characterized in that a lower stationary pole core is fixedly arranged in the guide sleeve and the magnet assembly is positioned between the lower and the upper pole core.

State of the art

Solenoid valves in the hydraulic unit have the task to hold the pressure medium or let it flow. Typically, these consist of several

Solenoid valves. For solenoid valves (MV) in ABS / TCS / ESP systems, certain requirements for tightness are made for the closed state, depending on the respective task of the MV in the system. The valves are generally designed so that function-dependent in a de-energized switching position

Permanent position is achieved (eg "closed" without power) and only for one

Short-term operation, the valve is energized (eg energized "open").

From the state of the art bistable valves are also known that normally reach a permanent position in two switching positions and only for the switching operation be energized between the permanent positions. For example, reference is made to the patent application WO 02/10628 AI.

Disclosure of the invention

Advantageously, however, allows the solenoid valve according to the invention an efficient holding and switching of the valve.

This is made possible according to the invention by those in the independent

Claims specified characteristics. Further embodiments of the invention are the subject of dependent claims.

The bistable solenoid valve according to the invention for a hydraulic brake system, with a guide sleeve in which an upper stationary pole core fixed and a

Closing element is arranged displaceably, wherein the closing element urges during a closing movement in a valve seat and lifts off during an opening movement of the valve seat and the closing element is fixedly connected to a magnet assembly wherein an actuation of the movement of the closing element by means of the magnet assembly via a coil, which around the Guide sleeve is positioned and this substantially comprises, characterized in that a lower stationary pole core is fixedly arranged in the guide sleeve and the

Magnet assembly is positioned between the lower and upper pole core.

This is understood to mean that the solenoid valve has two pole cores, between which a magnet assembly is positioned. The pole cores are firmly defined in their position and the magnet assembly between the pole cores movable. The magnet assembly is firmly connected to the closing element of the solenoid valve. The closing element, also called sealing element, serves in a first position to release the passage at the valve seat and thus to open the valve, or to obstruct the passage at the valve in a second position and thus to close the valve. The solenoid valve is bistable. This means that holding the

Closing element in these two different positions (ie in the closed position and in the open position) can be done without a permanent energization. In a bistable valve is by the energization of the coils only a switching of the switching state allows. Holding the

Closing element in the respective closed or open position takes place, for example. Through the magnet assembly. For this purpose, the magnet assembly consists for example of an upper permanent magnet, which is spatially closer to the upper pole core and a lower permanent magnet, which is located closer to the lower pole core. In this case, the valve or the closing element is held in the open position by the upper permanent magnet to the upper pole core. In an analogous manner, the valve or the closing element is held in the closed position by the lower permanent magnet to the lower pole core. Advantageously, this can be an energy-efficient retention of the valve in the respective position.

A change between the two stable positions takes place by a movement of the closing element. For this purpose, the coil is energized with a defined voltage. This creates a magnetic field. For example, the pole cores consist of a material which has ferromagnetic properties. The closing element itself consists of a non-magnetizable material, in particular

Plastic. The coil therefore magnetizes the upper and lower pole core. Due to their temporary magnetization, the upper and lower pole cores produce an influence on the magnet assembly, so that the closing element associated therewith is moved to the desired position. For example. For example, the closing element with the magnet assembly (at a corresponding position and energization of the coil) can be repelled by the lower pole core and attracted by the upper pole core. Alternatively, repelled from the upper pole core and tightened by the lower pole core.

In an advantageous embodiment, the armature, or the closing element with the magnet assembly, on the voltage applied to the coil current in a

Levitated, which is between the two stable

End positions lies.

It should be noted that, as already stated, the solenoid valve has an upper pole core, a lower pole core and a closing element with a magnet assembly. From this, as well as from the further description it becomes clear that the solenoid valve has no armature in the classical sense. The coil is advantageously pushed onto the guide sleeve. Furthermore, the coil is advantageously pre-assembled.

Advantageously, an energy-efficient switching of the valve is possible by the described construction of the valve. This efficiency has far-reaching influence on other components as well. For example, much smaller coils are necessary or possible. This in turn can reduce the use of copper and thus the costs. Furthermore, heat dissipation parts, in particular in the control unit, can also be dispensed with. In addition to the increased efficiency, the solenoid valve is also characterized by its simplicity. For example. is a very simple construction with fewer components possible. This leads to a cost-effective and resource-optimized production. Also, advantages in terms of a smaller space can be achieved.

In an advantageous embodiment, the bistable magnetic valve is characterized in that the magnet assembly is molded onto the closing element.

This is understood to mean that the magnet assembly and the closing element form a unit. As a result, the assembly effort can be reduced advantageously. The production can be carried out, for example, by means of an injection molding process. In this way, a positive connection can be made possible. Advantageously, a solid and non-detachable connection is thus created. Alternatively a molded

Magnetic assembly, the closing element may also have an injected magnetic assembly. For example. The plastic closure element may have two injection-molded permanent magnets separated from an insulation.

In one possible embodiment, the bistable solenoid valve is characterized

in that the magnet assembly is attached to one of the upper pole core

having facing side of the magnet assembly and at one of the lower Polkern facing side of the magnet assembly rectified magnetic poles, in particular each having a magnetic south pole or each having a magnetic north pole.

This is understood to mean that the magnet assembly at their two in

Direction of movement axial ends has the same magnetic pole. This means either a magnetic south pole or a magnetic at both ends North Pole. These axial ends are in relation to the direction of movement of the

Assembly, or the closing element to understand. The ends correspond in this sense to the end faces of the magnet assembly. Advantageously, by such a design, a simple achievement of the desired effect (repulsion and attraction of the Polkerne respect. The magnet assembly when energizing the coil) can be achieved without complex control of the coil and without complex construction of the coil.

In a preferred embodiment, the bistable solenoid valve is characterized

characterized in that the magnet assembly comprises a plurality of permanent magnets, in particular comprises two permanent magnets.

This is understood to mean that two or more permanent magnets form the assembly. The permanent magnets are for example designed as disk magnets. For receiving the and connection with the closing element, the

Permanent magnets have a hole in the middle through which the

Closing element extends. Advantageously, by such a structure and

Design a cost-effective and simple design allows.

In an alternative development, the bistable solenoid valve is characterized

characterized in that the permanent magnets are positioned in opposite directions.

This is understood to mean that the permanent magnets are aligned with each other with the same magnetic poles. For example. that two

Permanent magnets are arranged to each other so that the magnetic south pole of a first permanent magnet and the magnetic south pole of a second permanent magnet are oriented to each other. The magnetic poles in the assembly with two permanent magnets are therefore, for example, as follows: North - South, South - North. Advantageously, the desired effects can thus be achieved in a simple manner.

In an advantageous embodiment, the bistable solenoid valve is characterized

characterized in that the permanent magnets are separated by insulation. This is understood to mean that the magnet assembly has an insulation which is positioned between two permanent magnets. This advantageously achieves an improvement in efficiency and performance

In one possible embodiment, the bistable magnetic valve is characterized in that the lower stationary pole core is pressed into the guide sleeve.

This is understood to mean that the pole core is fixed in the guide sleeve by means of pressure. As a result, a simple and inexpensive installation can be made possible. Furthermore, a variation of the press-in depth is possible as a result. As a result, an optimized tuning of the position of

Closing element and valve seat can be achieved. This makes it possible, for example, to take into account and compensate manufacturing inaccuracies of the components. In an alternative embodiment, a welding can also be provided.

In a preferred embodiment, the bistable solenoid valve is characterized

characterized in that the lower pole core is positioned so that it is at least partially within the coil and / or that the upper pole core is positioned so that it is at least partially within the coil

This is to be understood that the length and position of the coil and / or the length and position of the pole cores are matched to one another and possibly adapted to each other, that the lower pole core and the upper pole core at least

partially axially located within the coil. Advantageously, an optimization of the efficiency with respect. The magnetization of the pole cores can be achieved.

In an alternative embodiment, the bistable magnetic valve is characterized in that the closing element is guided through an opening in the lower pole core.

By this is meant that the lower pole core has an opening. This is dimensioned so that the closing element is guided through this opening. Furthermore, it can be provided that this opening allows a guide for the closing element. Advantageously, by such a guide a precise fit of the Closing be allowed on the valve seat. As a result, a good seal is achieved in the closed valve state. Furthermore, this allows premature the elimination, or the avoidance of additional components for guiding the

Closing element.

In an advantageous development of the bistable solenoid valve is characterized

in that the closing element consists of non-magnetisable material, in particular plastic.

Advantageously, thereby performance and efficiency-reducing effects

Opening and closing process can be avoided.

The invention further provides a method for controlling a bistable

Solenoid valve provided according to one of the preceding claims, which is characterized in that energization of the solenoid valve in a first current direction leads to such a magnetization of the upper and lower pole core, that the upper pole core repels its associated permanent magnet of the magnet assembly and the lower pole core a him assigned

Permanent magnet of the magnet assembly attracts and energization of the solenoid valve in a second current direction to such a magnetization of the upper and lower pole core leads, that the lower pole core repels its associated permanent magnet of the magnet assembly and the upper pole core attracts a permanent magnet associated with the magnet assembly.

This is understood to mean that a control of the valve, in particular a control of the energization of the coils is carried out in such a way that a plurality of force components are generated which a movement of the

Support closure element from one position to a second position. Advantageously, this enables energy-efficient switching.

The invention further provides a method for assembling a bistable valve with a guide sleeve and with an upper pole core and a lower pole core and a closing element with a magnet assembly according to one of the preceding claims, which is characterized in that - In a first step, the upper pole core is connected to the guide sleeve and in a second step, the closing element is positioned in the lower pole core and introduced in a third step, the closing element together with the lower pole core in the guide sleeve and in a fourth step, the lower pole core is positioned together with the closing element in the guide sleeve and connected to this or

- In a first step, the upper pole core is connected to the guide sleeve and in a second step, the closing element is positioned in the guide sleeve and introduced in a third step, the lower pole core in the guide sleeve and positioned in a fourth step, the lower pole core in the guide sleeve and connected to this.

Below is a method for mounting a bistable valve with a

Guide sleeve and having an upper pole core and a lower pole core and a closing element with a magnetic assembly according to the present description to understand, first the upper pole core is connected to the guide sleeve and then the closing element is introduced together with the lower pole core in the guide sleeve and the lower Polkern is connected to the guide sleeve. Alternatively, it is provided that initially the upper pole core is connected to the guide sleeve and connect the closing element in the

Guide sleeve is introduced and then the lower pole core in the

Guide sleeve is introduced and connected. Advantageously, a simple installation of the valve is made possible in this way.

Furthermore, the invention provides a hydraulic brake system for a motor vehicle with at least one bistable solenoid valve according to the present description for controlling a brake fluid.

By this is meant that, for example, an automated

Parking brake system with a hydraulic brake fluid can integrate the described bistable valve. This allows the solenoid valve to be held in an open or closed position. Furthermore, advantageously the changeover from one position to the other takes place in a very efficient manner. Also, by avoiding a continuous current to hold a position, the noise and vibration development can be largely reduced or even avoided. embodiments

It should be noted that those detailed in the description

Features can be combined with each other in any technically meaningful way and show further embodiments of the invention. Further features and expediency of the invention will become apparent from the description of

Embodiments with reference to the accompanying figures.

From the figures shows:

Fig. 1 is a schematic sectional view of a bistable solenoid valve according to an embodiment of the invention; and

Fig. 2 is a detail view of the closing element and the magnet assembly according to an embodiment of the invention, and

Fig. 3 is a schematic sketch of the forces and movements at different energization according to an embodiment of the invention.

Fig. 1 shows a schematic sectional view of a bistable solenoid valve. The solenoid valve 1 has a guide sleeve 2. In this guide sleeve 2, an upper pole core 5 and a lower pole core 6 is anchored. Furthermore, in the

Guide sleeve 2, a closing element 3 movably positioned. With this

Closing element 3 is firmly connected to a magnetic assembly 8. This

Magnetic assembly 8 consists of two permanent magnets 8 ^' and 8 ^" . The two permanent magnets 8 ^' and 8 ^" are separated from each other by an insulation 9. The closing element 3 acts in a lower position sealingly together with the valve seat 4, as shown in FIG. In a deflection from this position, the closing element 3 releases the valve seat 4 and allows the flow of a

hydraulic medium. The closing element 3 runs through a hole in the lower pole core 6 and is guided thereby. On the guide sleeve 2, a coil 7 is further pushed. This coil 7 comprises the guide sleeve 2

full. The length of the coil 7, or the position of the upper pole core 5 and the lower pole core 6 are selected or matched to one another such that the coil 7 the upper pole core 5 and lower pole core 6 at least partially includes. The

Pole cores 5, 6 respectively project into the exciter coil, i. the coil 7, and fill them to a part of their length. 2, a detailed view of the closure member and the magnet assembly is shown.

The permanent magnet assembly 8 is made of an upper

Permanent magnets 8 ^' and a lower permanent magnet 8 ^" formed .. The two permanent magnets 8 ^' and 8 ^" are separated by the insulation 9 from each other. The permanent magnets 8 ^' and 8 ^" furthermore have a hole through which the closing element 3 is guided

Plastic molded. For example, an injection molding process is used for the production. By gating and undercut a firm connection between the magnet assembly 8 and the closing element 3 is ensured. Fig. 3 shows a schematic sketch of the forces and movements at different

Energization. The left-hand illustration shows a magnetic field line of an emerging magnetic field and effective forces during a first energization. In this case, a polarized magnetic field is generated by applying a defined first (eg positive) voltage to the coil 7. The illustrated oval line shows by way of example a magnetic field line. By this magnetic field, and the upper pole core 5 and the lower pole core 6 is magnetized. The magnetization of the pole cores (as well as the magnetic field generated by the coil 7) results in an interaction with the magnet assembly 8. For example, the magnet assembly 8 (actually the lower permanent magnet 8 ^' ) is repelled by the polarized magnetized lower pole core 6. At the same time, the magnet assembly 8 (strictly, the upper permanent magnet 8 ^" ) is attracted by the polarized magnetized upper pole core 5. This results in a movement of the axially movable magnet assembly 8 as well as the fixed thereto

connected closing element 3 in the upper position. This force and consequent movement is shown by the upward arrow. In the upper position, the closing member 3 becomes the magnetic force of the magnet assembly 8

(In particular, the upper permanent magnet 8 ^' ) even after removal of the energization of the coil 7 is held. The solenoid valve 1 is thus in a stable open state. The right-hand illustration of FIG. 3 also shows the magnetic field and effective forces during a second energization. In this case, by applying a defined second (eg negative) voltage to the coil 7 with respect to the first defined voltage opposite polarized magnetic field generated. In a manner analogous to the previous description, the magnet assembly 8 (strictly speaking, the lower permanent magnet 8 ^' ) is repelled by the oppositely polarized magnetized upper pole core 5. At the same time, the magnet assembly 8 (strictly, the upper permanent magnet 8 ^" ) is attracted by the oppositely polarized magnetized lower pole core 6. This results in movement of the axially movable magnet assembly 8 and the closure member fixedly connected thereto to the lower position the closing element by the magnetic force of the magnet assembly 8 (in particular of the lower permanent magnet 8 ^" ) even after a removal of the current

Coil 7 held. The solenoid valve 1 is thus in a stable closed state.

Claims

claims

1. Bistable solenoid valve (1) for a hydraulic brake system,

with a guide sleeve (2) in which an upper stationary pole core (5) is fixedly arranged and a closing element (3) is displaceable,

wherein the closing element (3) during a closing movement in a valve seat (4) urges and during an opening movement of the valve seat (4) lifts and the closing element (3) with a magnetic assembly (8) is fixedly connected to an actuation of the movement of the closing element ( 3) by means of

Magnet assembly (8) via a coil (7), which is positioned around the guide sleeve (2) and this substantially comprises

characterized in that

a lower stationary pole core (6) is fixedly arranged in the guide sleeve (2) and the magnet assembly (8) is positioned between the lower pole core (6) and the upper pole core (5).

2. Bistable solenoid valve (1) according to claim 1, characterized in that the magnet assembly (8) is molded onto the closing element (3).

3. Bistable solenoid valve (1) according to one of the preceding claims, characterized in that the magnet assembly (8) at one of the upper pole core

(5) facing side of the magnet assembly (8) and at a lower pole core

(6) facing side of the magnet assembly (8) has rectified magnetic poles, in particular each having a magnetic south pole or each having a magnetic north pole.

4. Bistable solenoid valve (1) according to one of the preceding claims, characterized in that the magnet assembly (8) comprises a plurality of permanent magnets (8 ^' , 8 ^" ), in particular two permanent magnets (8 ^' , 8 ^" ).

5. Bistable solenoid valve (1) according to claim 4, characterized in that the permanent magnets (8 ^' , 8 ^" ) are positioned in opposite directions.

6. Bistable solenoid valve (1) according to claim 4 or 5, characterized in that the permanent magnets (8 ^' , 8 ^" ) are separated by an insulation (9).

7. Bistable solenoid valve (1) according to one of the preceding claims, characterized in that the lower stationary pole core (6) is pressed into the guide sleeve (2).

8. bistable solenoid valve (1) according to one of the preceding claims, characterized in that the lower pole core (6) is positioned so that it is at least partially within the coil (7) and / or that the upper pole core (5) so is positioned so that it is at least partially within the coil (7)

9. bistable solenoid valve (1) according to any one of the preceding claims, characterized in that the closing element (3) made of non-magnetizable material, in particular plastic.

10. A method for controlling a bistable solenoid valve (1) according to any one of the preceding claims, characterized in that energizing the solenoid valve (1) in a first current direction to such a magnetization of the upper pole core (5) and lower pole core (6), that the upper pole core (5) repels a permanent magnet (8 ^' ) of the magnet assembly (8) assigned to it and the lower pole core (6) has a permanent magnet (8 ^" ) associated therewith

Magnetic assembly 08 attracts and energizing the solenoid valve (1) in a second current direction to such a magnetization of the upper pole core (5) and lower pole core (6) results in that the lower pole core (6) has a permanent magnet associated therewith (8 ^" ) of the magnet assembly (8) repels and the upper pole core (5) a permanent magnet associated with it (8 ^' ) of the magnet assembly (8) attracts.

11. A method for mounting a bistable solenoid valve (1) with a

Guide sleeve (2) and with an upper pole core (5) and a lower pole core (6) and a closing element (3) with a magnet assembly (8) according to any one of the preceding claims, characterized in that

- In a first step, the upper pole core (5) with the guide sleeve (2) is connected and in a second step, the closing element (3) in the lower pole core (6) is positioned and in a third step, the closing element (3) together with the lower pole core (6) introduced into the guide sleeve (2) and positioned in a fourth step, the lower pole core (6) together with the closing element (3) in the guide sleeve (2) or is connected to this or

- In a first step, the upper pole core (5) with the guide sleeve (2) is connected and in a second step, the closing element (3) in the guide sleeve (2) is positioned and in a third step, the lower pole core (6) in the

Guide sleeve (2) introduced and positioned in a fourth step, the lower pole core (6) in the guide sleeve (2) and is connected thereto.

12. A hydraulic brake system for a motor vehicle with at least one bistable solenoid valve (1) according to one of claims 1 to 10 for controlling a brake fluid.