WO2018068928A1

WO2018068928A1 - Solenoid valve and hydraulic braking system for a vehicle

Info

Publication number: WO2018068928A1
Application number: PCT/EP2017/070740
Authority: WO
Inventors: Dietmar Kratzer
Original assignee: Robert Bosch Gmbh
Priority date: 2016-10-13
Filing date: 2017-08-16
Publication date: 2018-04-19
Also published as: DE102016219937A1

Abstract

The invention relates to a bistable solenoid valve (10A; 10B) for a hydraulic braking system (1), comprising: a magnetic assembly; a pole core (30A; 30B); a guide sleeve (13) joined to the pole core (30A; 30B); a valve armature (20A; 20B) running axially movably within the guide sleeve (13), the armature being drivable in opposition to a force of a restoring spring (16A; 16B) by means of a magnetic force produced by the magnetic assembly, or being drivable by the force of the at least one restoring spring (16,48), and said armature axially moving a plunger (40A; 40B) comprising a closing element (48); and a valve body (15) connected to the guide sleeve (13) and comprising a valve seat (15.1) that is located between at least one first flow opening (15.2) and at least one second flow opening (15.3). The invention also relates to a hydraulic braking system (1) comprising a claimed bistable solenoid valve (10A; 10B). In the claimed bistable solenoid valve, the plunger (40A; 40B) is axially moveably mounted in the valve armature (20A; 20B), a mechanical detent device (18) being formed between the pole core (30A; 30B) and the plunger (40A; 40B), the detent device releasing the plunger (40A; 40B) when the latter is in a de-energised closed position, such that the restoring spring (16A; 16B) pushes the closing element (34) sealingly into the valve seat (15.1) to produce a sealing function, and said detent device fixes the plunger (40A; 40B) in a de-energised open position against the force of the restoring spring (16A;16B) in an axial detent position, such that the closing element (48) is raised from the valve seat (15.1).

Description

Description title

The invention is based on a solenoid valve for a hydraulic brake system according to the preamble of independent claim 1. The subject of the present invention is also a hydraulic brake system for a vehicle having such a solenoid valve. The prior art discloses hydraulic brake systems for vehicles having a master cylinder, a hydraulic unit and a plurality of wheel brakes, which include various safety systems, such as an anti-lock braking system (ABS), electronic stability program (ESP), etc., and various safety functions, such as anti-lock, traction control (ASR) and so on. About the

Hydraulic unit control and / or regulating operations in the anti-lock braking system (ABS) or in the traction control system (ASR system) or in the electronic stability program system (ESP system) for the pressure build-up or pressure reduction can be performed in the corresponding wheel brakes. To carry out the control and / or regulating operations, the hydraulic unit comprises solenoid valves, which are usually held in unambiguous positions due to the counteracting forces "magnetic force", "spring force" and "hydraulic force." Accordingly, there are the valve types "normally open" and "de-energized These solenoid valves each comprise a magnet assembly and a valve cartridge having a pole core, a guide sleeve connected to the pole core, an armature axially guided within the guide sleeve against the force of a return spring between a closed position and an open position with a plunger and a By energizing the magnet assembly, a magnetic force is generated which closes the magnet Armature with the plunger and the closing element in an open solenoid valve moves from the open position to the closed position until the closing element meets the corresponding valve seat and seals it. In the de-energized state, the return spring moves the armature with the plunger and the closing element and the closing element lifts off from the valve seat and releases it. When the solenoid valve is not energized, the armature with the plunger and the closing element is moved from the closed position to the open position by the energization of the magnet assembly, and the closing element lifts out of the valve seat and releases it. If the current is switched off, then the restoring spring moves the magnet armature with the closing element in the direction of the valve seat until the closing element hits the valve seat and seals it. This energization is accompanied by energy consumption, which is undesirable. In addition, the functional reliability or functional availability is not given to the desired extent if the function is only achieved via active current supply.

In the patent application DE 10 2007 051 557 AI, for example, a normally closed solenoid valve for a slip-controlled, hydraulic vehicle brake system is described. The solenoid valve comprises a hydraulic part, also referred to as a valve cartridge, which is partially in a stepped manner

Hole of a valve block is arranged, and an electrical part, which is formed essentially of a magnetic assembly which is mounted on the protruding from the valve block part of the valve cartridge. The magnet assembly comprises a coil body with an electrical winding, a magnet flux-conducting coil jacket and a magnetic flux-conducting annular disk. The hydraulic part has a guide sleeve, which is closed at its end facing the electrical part with a pressed-in and fluid-tight welded pole core. In the guide sleeve, a longitudinally displaceable armature is accommodated, which is supported by a return spring on the pole core. Polkernabgewandt, the armature has a spherical closure member arranged in a recess. At Polkernabgewandten end a cup-shaped valve sleeve with a cylindrical shell and a bottom is pressed into the guide sleeve. The valve sleeve has at the bottom of a passage and a hollow cone-shaped valve seat, which forms a seat valve with the closing body. With the seat valve is a fluid connection between the Passage made at the bottom of the valve sleeve and at least one passage in the shell of the valve sleeve switchable. In addition, a radial filter is arranged outside on the jacket of the valve sleeve in order to filter dirt particles from the fluid flow. The guide sleeve can be caulked by means of a fastening bush in the stepped bore of the valve block.

From EP 0 073 886 Bl a hydraulic control device with an axially displaceable in a plurality of switching positions and automatically by means of a return spring in one of its switching positions control spool is known, which outside this switch position can be fixed by engaging in latching points spring-loaded detent, which further by a Piston in a housing bore guided and acted upon by an adjacent annular space with hydraulic fluid pressure member is hydraulically actuated. The annulus is connected via a pilot valve with the leading to the consumer pump pressure line in connection, which is depressurized at shutdown of the consumer or. Here, the hydraulic travel of the catch is limited compared to its possible against spring travel and the locking points on the spool for engaging or engaging behind the catch are radially dimensioned so that a hydraulic release of the catch regardless of the potential against spring force adjustment only to the designated Rest positions is possible.

Disclosure of the invention

The solenoid valve for a hydraulic brake system with the features of independent claim 1 has the advantage that in a solenoid valve with a de-energized first operating state, another currentless second operating state can be implemented. This means that embodiments of the present invention provide a bistable solenoid valve which can be switched over by applying a switching signal between the two operating states, wherein the solenoid valve remains permanently in the respective operating state until the next switching signal. Here, the first operating state of a closed position of the solenoid valve and the second operating state may correspond to an open position of the solenoid valve. The change between the two operating states can be achieved, for example, by brief energization of the active actuator of the magnet assembly or by laying a switching signal or current pulse to the magnet assembly are performed. With such a short energization, the energy consumption in comparison with a conventional solenoid valve with two operating states can be advantageously reduced, which has only a currentless first operating state and must be energized to implement the energized second operating state for the duration of the second operating state. In addition, in contrast to embodiments of the present invention, the functional reliability or functional availability is not given to the desired extent if the function can only be achieved via active current supply.

Embodiments of the present invention provide a solenoid valve for a hydraulic brake system, comprising a magnet assembly, a pole core, a guide sleeve connected to the pole core, an axially within the guide sleeve guided valve armature, which is generated by a magnetic force generated by the magnet assembly against the force of a return spring or by the force of the return spring is drivable and axially moves a plunger with a closing element, and a valve body connected to the guide sleeve with a valve seat available, which is arranged between at least a first flow opening and at least one second flow opening. Here, the plunger is axially movably mounted in the valve armature, between the pole core and the plunger, a mechanical detent device is formed, which releases the plunger in a de-energized closed position, so that the return spring presses the closing element to perform a sealing function in the valve seat, and the Plunger in an energized open position against the force of the return spring in an axial detent position so determines that the closing element is lifted from the valve seat. In the de-energized closed position, the fluid flow between the at least one first flow opening and the at least one second flow opening is interrupted, and in the de-energized open position, the fluid flow between the at least one first flow opening and the at least one second flow opening is made possible. Embodiments of the solenoid valve according to the invention advantageously have a very low leakage in the closed position and low energy consumption in the open position. In addition, a hydraulic brake system for a vehicle is proposed, which comprises a master cylinder, a hydraulic unit and a plurality of wheel brakes. In addition, the hydraulic unit comprises at least two brake circuits for brake pressure modulation in the wheel brakes. In this case, the at least two brake circuits each have at least one solenoid valve according to the invention, which releases the brake pressure modulation in at least one associated wheel brake in the de-energized open position and, in the de-energized closed position, includes a current brake pressure in the at least one associated wheel brake.

The hydraulic brake system for a vehicle with the features of independent claim 16 has the advantage that with little additional effort to a mostly existing hydraulic unit with ESP functionality an additional function can be realized, which include a current brake pressure in the corresponding wheel brake electro-hydraulic and at low energy demand over a longer period of time. This means that the existing pressure supply, the piping from the hydraulic unit to the wheel brakes as well as sensor and communication signals not only for the ESP function and / or ABS function and / or ASR function but also for an electro-hydraulic pressure maintenance function in the wheel brakes can be used. As a result, costs, installation space, weight and wiring can advantageously be saved with the positive effect that the complexity of the brake system is reduced.

The measures and refinements recited in the dependent claims advantageous improvements of the independent claim 1 solenoid valve for a hydraulic brake system are possible.

It is particularly advantageous that the mechanical locking device is designed as a rotary mechanism that uses a peripheral force component, to axially move the plunger with the closing element in the locking position and out again, so that the closing element can easily switch between the two de-energized positions by applying a switching signal or current pulse to the magnet assembly. Starting from the de-energized closed position, the closing element can switch from the de-energized closed position to the de-energized open position by applying a switching signal. When a subsequent switching signal is applied, the closing element changes back from the de-energized open position to the de-energized closed position. Starting from the currentless open position, the closing element can switch by applying a switching signal from the currentless open position to the currentless closed position. When a subsequent switching signal is applied, the closing element changes back from the de-energized closed position into the de-energized open position. In an advantageous embodiment of the solenoid valve, a cylindrical depression can be introduced into a base body of the pole core at the end facing the valve armature, which recess partially receives the tappet and the valve armature. The restoring spring can be arranged in the recess and act between the pole core and the plunger, wherein the plunger can be radially guided in a passage opening of the valve anchor and can be moved axially in the direction of the pole core by the valve anchor and in the direction of the valve seat by the return spring.

In a further advantageous embodiment of the solenoid valve, the plunger may have a cylindrical base body, at one end of a first guide geometry is formed, which formed in the axial movement with a trained on the main body of the valve anchor second guide geometry and formed on the pole core third guide geometry and one on the pole core fourth guide geometry can cooperate, which can be formed in the recess of the main body of the pole core. The plunger is preferably produced as a plastic component in an injection molding process. Alternatively, the ram may be made by powder injection molding (PIM) or ceramic injection molding (CIM) or metal injection molding (MIM), etc., or by 3D printing. In addition, the plunger can be made in one piece at its tip as a closing element for the valve seat. Alternatively, you can the plunger are made in several parts and, for example, an additional sealing element, such as an O-ring seal, which is arranged in the region of the closing element and improves the sealing effect in the closed position. In addition, a division of the ram geometry in other parts is possible. The valve anchor may have a stepped cylindrical base body with two different outer diameters, wherein a portion of the main body of the valve anchor immersed in the recess of the pole core may have a fifth guide geometry which, in axial movement, can cooperate with the third guide geometry in the recess of the main body of the pole core , Due to the requirement of the magnetic conductivity of the valve armature is made of a magnetically conductive material, for example in the cold impact method or by machining. The pole core is also made of a magnetically conductive material.

In a further advantageous embodiment of the solenoid valve, the first guide geometry may comprise a plurality of formations in uniform pitch on the circumference of the main body of the plunger, each having a one-sided bevel and can be supported in the axial movement in the direction of pole core on the second guide geometry of the valve arm, which at the edge the passage opening in uniform angular division introduced anchoring grooves with two-sided chamfers may include, which can be adapted to the one-sided bevels of the formations of the plunger. Furthermore, the third guide geometry of the pole core on the wall of the recess in a uniform angular pitch Axialnuten having at least two different depths in the radial direction, wherein the fifth guide geometry on the main body of the valve armature may comprise radial guide webs which can be guided axially in corresponding axial grooves of the pole core , Here, the fourth guide geometry of the pole core can have unilateral bevels on intermediate webs of the axial grooves, which can be adapted to the one-sided bevels of the formations of the tappet. As a result, the one-sided chamfers of the formations of the plunger advantageously fit into the correspondingly designed, double-angled tapered anchoring grooves of the valve anchor and at the same time into the one-sided beveled intermediate webs of the axial grooves of the pole core. In a further advantageous embodiment of the solenoid valve, the valve anchor can take over its Ankernuten the plunger on its formations in a magnetic force caused by the magnetic assembly axial movement in the direction of Polkern, wherein the bevels of the Ankernuten and the bevels of the formations of the plunger during the axial movement in the direction Polkern a Peripheral force can act on the plunger, which tries to turn the plunger about its longitudinal axis. In this case, the simultaneous guidance of the formations of the plunger and / or the radial guide webs of the valve core in the axial grooves of the pole core can prevent this rotational movement until the plunger reaches a predetermined Axialhub and the formations of the plunger can leave the axial grooves of the pole core and still due acting circumferential force can slide deeper into the Ankernuten, the formations of the plunger slip into the next axial grooves of the Polkerns and the new leadership can follow by a radial movement when the axial stroke of the valve armature and the plunger is reduced due to the acting spring force of the return spring, wherein the Formations of the plunger can slip simultaneously into the next anchor groove. Thus, for example, in the currentless open position, at least two protrusions of the plunger can each be held axially in an axial groove flatter in the radial direction. Here, the chamfers of the formations of the plunger bear against chamfers, which are formed on the edge of flatter Axialnuten. In the de-energized closed position, all the formations of the plunger can each be guided in an axial groove deeper in the radial direction as far as the stop of the closing element in the valve seat. The numbers and angular pitches of the various formations and grooves and the respective angle of inclination can be selected in a meaningful manner depending on the dimensions of the solenoid valve in order to approach with a conventional magnetic axial air gap, the various stroke positions via a magnetic force generated by a commercially available magnet assembly becomes. In other circumstances, the numbers, angle divisions, helix angles, etc. can be adjusted accordingly.

In a further advantageous embodiment of the solenoid valve, a second return spring can be arranged in an air gap between a first pole face of the valve armature and a second pole face of the pole core. anchor in the direction of the valve seat can move. The second closing-acting return spring is preferably designed as a very spring soft compression spring and presses the valve armature in the de-energized state constantly to the respective lowest possible position in the direction of the valve seat. As a result, an undefined position of the valve armature, an anchor life on the pole core and anchor rappings or the like can be avoided in an advantageous manner.

In a further advantageous embodiment of the solenoid valve, the return spring can be performed in a designed as a recess spring receptacle in the main body of the plunger and are supported at the bottom of the spring receptacle and at the bottom of the recess in the main body of the pole core. Alternatively, the return spring can be supported on a spring support, which is arranged on an end face of the basic body of the tappet, and on the bottom of the depression in the base body of the pole core. In this embodiment, a blind hole can be introduced at the bottom of the recess in the main body of the pole core, which at least partially receives the return spring. As a result, the plunger can be made thinner and the guide geometries on the valve armature and on the pole core can migrate inwards, so that larger magnetically effective pole faces can be provided between the valve armature and the pole core.

In a further advantageous embodiment of the solenoid valve, the pole core can be made in several parts, wherein the main body of the pole core is magnetically effective and has a first cylindrical part and a second tubular part. In the tubular part of a plastic injection molded part can be pressed, which has the third guide geometry and the fourth guide geometry. As a result, the complex geometries can be produced simply and inexpensively by suitable production methods, such as, for example, plastic injection molding, and the magnetically active basic body can be produced, for example, more massively in metal by cold forming.

In a further advantageous embodiment of the solenoid valve, the valve anchor can be made in several parts, wherein the immersed in the recess of the pole core portion of the main body of the valve armature as a plastic injection molded part and arranged outside of the pole core portion of the body as Mag- netisch effective metal part can be executed. This results in an advantageous manner, a precise guidance in the guide sleeve and reduced magnetic leakage flux outside the intended for the magnetic flux planar pole face of the valve armature.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. In the drawing, like reference numerals designate components that perform the same or analog functions.

Brief description of the drawings

Fig. 1 shows a schematic perspective sectional view of a first embodiment of a solenoid valve according to the invention.

FIG. 2 shows a schematic perspective illustration of an exemplary embodiment of a tappet for the solenoid valve from FIG. 1.

FIG. 3 shows a schematic perspective illustration of an exemplary embodiment of a valve armature for the magnetic valve from FIG. 1.

FIG. 4 shows a schematic perspective view of the plunger of FIG. 2 inserted into the valve anchor of FIG. 3. FIG.

5 shows a schematic perspective sectional view of an exemplary embodiment of a pole core for the magnetic valve from FIG. 1.

FIG. 6 shows a schematic perspective sectional view of the valve anchor of FIG. 3 partially inserted into the pole core of FIG. 5. FIG.

FIG. 7 shows a sectional view along the section line VII - VII in FIG. 1.

FIG. 8 shows a sectional view along the section line VIII-VIII in FIG. 1. 9 shows a schematic perspective sectional view of a second embodiment of a solenoid valve according to the invention.

10 shows a schematic hydraulic circuit diagram of an exemplary embodiment of a hydraulic brake system according to the invention for a vehicle.

Embodiments of the invention

As can be seen from FIGS. 1 to 9, the exemplary embodiments illustrated include a solenoid valve 10A, 10B according to the invention for a hydraulic valve

Braking system 1 each have a magnetic assembly, not shown, a pole core 30A, 30B, a guide sleeve 13 connected to the pole core 30A, 30B, an axially guided within the guide sleeve 13 valve armature 20A, 20B, which of a magnetic force generated by the magnet assembly against the force of a Return spring 16A, 16B or by the force of the return spring 16A,

16B is driven and a plunger 40A, 40B axially moved with a closing element 48, and connected to the guide sleeve 13 valve body 15 with a valve seat 15.1, which is arranged between at least a first flow opening 15.2 and at least one second flow opening 15.3. Here, the plunger 40A, 40B is axially movably mounted in the valve armature 20A, 20B, wherein between the pole core 30A, 30B and the plunger 40A, 40B, a mechanical locking device 18 is formed, which releases the plunger 40A, 40B in an energized closed position, so that the restoring spring 16A, 16B sealingly presses the closing element 48 into the valve seat 15.1 to perform a sealing function, and a fluid flow between the at least one first

Flow opening 15.2 and the at least one second flow opening 15.3 interrupts, and the plunger 40 A, 40 B in an illustrated currentless open position against the force of the return spring 16A, 16B so defined in an axial detent position that the closing element 48 lifted off the valve seat 15.1 and the fluid flow between the at least one first flow opening 15.2 and the at least one second flow opening 15.3 is made possible.

Thereby, a bistable solenoid valve 10A, 10B is implemented, which can be switched by applying a switching signal between the two positions, wherein the solenoid valve 10A, 10B remains permanently in the respective operating state until the next switching signal. Such a bistable solenoid valve 10A, 10B can be used for example in a hydraulic brake system 1 for a vehicle. As can be seen from FIG. 10, the illustrated exemplary embodiment of a hydraulic brake system 1 according to the invention for a vehicle, with which various safety functions can be carried out, comprises a master cylinder 5, a hydraulic unit 9 and a plurality of wheel brakes RR, FL, FR, RL. The hydraulic unit 9 comprises at least two brake circuits BC1, BC2 for braking pressure modulation in the wheel brakes RR, FL, FR, RL. In this case, the at least two brake circuits BC1, BC2 each have a bistable solenoid valve 10A, 10B, which has an electroless closed position and an electroless open position and can be switched between the two positions, wherein the bistable solenoid valve 10A, 10B in the de-energized open position, the brake pressure modulation in at least one associated wheel brake

RR, FL, FR, RL releases and in the de-energized closed position includes a current brake pressure in the at least one associated wheel brake RR, FL, FR, RL. As can also be seen from FIG. 10, the illustrated exemplary embodiment of the hydraulic brake system 1 comprises two brake circuits BC1, BC2, to each of which two of the four wheel brakes RR, FL, FR, RL are assigned. Thus, a first wheel brake FR, which is arranged for example on a vehicle front axle on the right side, and a second wheel brake RL, which is arranged for example on a vehicle rear axle on the left side, associated with a first brake circuit BC1. A third wheel brake RR, which is arranged, for example, on a vehicle rear axle on the right side, and a fourth wheel brake FL, which is arranged for example on the vehicle front axle on the left side, are associated with a second brake circuit BC2. Each wheel brake RR, FL, FR, RL is an inlet valve EVll, EV21,

EV12, EV22 and an exhaust valve AV11, AV21, AV12, AV22 assigned, via the intake valves EVll, EV21, EV12, EV22 each pressure in the corresponding wheel brake RR, FL, FR, RL can be constructed, and wherein the exhaust valves AV11, AV21, AV12, AV22 pressure in the corresponding wheel brake RR, FL, FR, RL can be reduced. For pressure build-up in of the respective wheel brake RR, FL, FR, RL, the corresponding intake valve EV11, EV12, EV21, EV22 is opened and the corresponding exhaust valve AVll, AV12, AV21, AV22 are closed. For depressurization in the respective wheel brake RR, FL, FR, RL, the corresponding intake valve EV11, EV21, EV12, EV22 is closed and the corresponding exhaust valve AVll,

AV21, AV12, AV22 open.

As further shown in FIG. 10, the first wheel brake FR is assigned a first intake valve EV11 and a first exhaust valve AVll, and the second wheel brake RL is a second intake valve EV21 and a second exhaust valve

Assigned to the third wheel brake RR, a third intake valve EV12 and a third exhaust valve AV12 and the fourth wheel brake FL are associated with a fourth intake valve EV22 and a fourth exhaust valve AV22. The intake valves EV11, EV21, EV12, EV22 and the exhaust valves AV11, AV21, AV12, AV22 can be used to perform control and / or regulating operations to implement an ABS function.

In addition, the first brake circuit BCl has a first intake valve HSV1, a first system pressure control valve USV1, a first compensation reservoir AI with a first check valve RSV1 and a first fluid pump PE1. The second

Brake circuit BC2 has a second intake valve HSV2, a second system pressure control valve USV2, a second surge tank A2 with a second check valve RSV2 and a second fluid pump PE2, wherein the first and second fluid pumps PE1, PE2 are driven by a common electric motor M. Furthermore, the hydraulic unit 9 for determining the current system pressure or brake pressure comprises a sensor unit 9.1. The hydraulic unit 9 uses the first system pressure control valve USV1, the first intake valve HSVl and the first return pump PE1 for braking pressure modulation and for implementing an ASR function and / or an ESP function in the first brake circuit BCl, and the second system pressure control valve USV2 in the second brake circuit BC2, the second intake valve HSV2 and the second return pump PE2. As can also be seen from FIG. 10, each brake circuit BCl, BC2 is connected to the master brake cylinder 5, which can be actuated via a brake pedal 3. In addition, fluid container 7 is connected to the master cylinder 5. The intake valves HSVl, HSV2 allow intervention in the brake system without a driver's request. For this purpose, the respective suction path for the corresponding fluid pump PE1, PE2 is opened to the master cylinder 5 via the intake valves HS VI, HSV2, so that they can provide the required pressure for the control instead of the driver. The system pressure control valves USV1, USV2 are arranged on the master brake cylinder 5 and at least one associated wheel brake RR, FL, FR, RL and set the system pressure or brake pressure in the associated brake circuit BC1, BC2. As can also be seen from FIG. 10, a first system pressure control valve USV1 adjusts the system pressure or brake pressure in the first brake circuit BC1, and a second system pressure control valve USV2 sets the system pressure or brake pressure in the second

Brake circuit BC2.

As can also be seen from FIG. 10, the bistable solenoid valves 10A, 10B can be looped into the respective brake circuit BC1, BC2 at different positions PI, P2, P3, P4, P5. In the illustrated embodiments, the various positions PI, P2, P3, P4, P5 are respectively designated in the second brake circuit BC2. As can also be seen from FIG. 10, the bistable solenoid valves 10A, 10B are each at a first position PI between the corresponding system pressure control valve USV1, USV2 and the inlet valves EV11, EV12, EV21, EV22 in front of an outlet channel of the corresponding fluid pump PE1, PE2 looped into the respective brake circuit BC1, BC2. Alternatively, the bistable solenoid valves 10A, 10B can each be looped into the respective brake circuit BC1, BC2 at a second position P2 between the master brake cylinder 5 and the corresponding system pressure control valve USV1, USV2 directly in front of the corresponding system pressure control valve USV1, USV2. As a further alternative arrangement, the bistable solenoid valves 10A, 10B can each be looped into the respective brake circuit BC1, BC2 at a third position P3 between the corresponding system pressure control valve USV1, USV2 and the inlet valves EV11, EV12, EV21, EV22 downstream of the outlet channel of the fluid pump PE1, PE2 become. In addition, in another alternative arrangement, the bistable solenoid valves 10A, 10B can each be looped into the respective brake circuit BC1, BC2 at a fourth position P4 between the master brake cylinder 5 and the corresponding system pressure control valve USV1, USV2 in the common fluid branch directly after the master brake cylinder 5. In addition, the bistable solenoid valves 10A, 10B are each looped into a fifth position P5 directly in front of an associated wheel brake RR, FL, FR, RL in the respective brake circuit BC1, BC2.

As is further apparent from FIG. 10, in the exemplary embodiment of the hydraulic brake system 1 an electrical energy store in the form of a vehicle electrical system is used in order to operate in the at least one associated wheel brake RR, FL, FR, RL in the currentless closed position of the bistable solenoid valve 10A. 10B trapped brake pressure by Nachfördern of brake fluid via the fluid pump PE1, PE2 constant. Since electrical energy is required only for valve switching and for the short Nachförderfunktion, there is only a small additional electrical energy requirement for the brake pressure maintenance function. Alternatively, in an embodiment not shown, hydraulic storage devices may be used to maintain the brake pressure contained in the at least one associated wheel brake RR, FL, FR, RL in the de-energized closed position of the bistable solenoid valve 10A, 10B constant by adding brake fluid. Since electrical energy is required only for valve switching, but virtually no electrical energy is required for the Nachförderfunktion, results from the hydraulic storage devices even lower electrical energy requirements for the brake pressure maintenance function.

The described measures advantageously make it possible to compensate for any internal leakage and volume expansions which may occur due, for example, to temperature fluctuations. In addition, the described measures can be combined. That is, the hydraulic storage device may be combined with the electrical storage device to maintain a constant brake pressure trapped in the de-energized closed position of the bistable solenoid valve 10A, 10B in the at least one associated wheel brake RR, FL, FR, RL by recharging brake fluid over a longer period of time to keep.

As is further apparent from FIGS. 1 to 9, the mechanical latching device 18 is designed as a rotary cam mechanism which utilizes a circumferential force component to axially move the plunger 40A, 40B with the closing element 48 into and out of the latching position, so that the closing element 48 can switch between the two de-energized positions by applying a switching signal or current pulse to the magnet assembly.

As can also be seen from FIGS. 1 to 9, a cylindrical depression 36 A, 36 B is in a base body at the end facing the valve armature 20 A, 20 B

32A, 32B of the pole core 30A, 30B which partially receives the plunger 40A, 40B and the valve anchors 20A, 20B. The main body 32A, 32B of the pole core 30A, 30B is made of a magnetically conductive material and has a cylindrical top which is elongated in a tubular geometry which forms the cylindrical recess 36A, 36B. The return spring 16A, 16B is also disposed in the recess 36A, 36B and acts between the pole core 30A, 30B and the plunger 40A, 40B. The plunger 40A, 40B is radially guided in a passage opening 24A, 24B of the valve armature 20A, 20B and can be moved axially by the valve armature 20A, 20B in the direction of the pole core 30A, 30B and by the return spring 16A, 16B in the direction of the valve seat 15.1.

The plunger 40A, 40B has in the illustrated embodiments, a cylindrical body 42 A, 42 B, at one end of a first guide geometry 46 is formed which in the axial movement with a formed on the base body 22A, 22B of the valve armature 20A, 20B second

Guide geometry 27 and formed on the pole core 30A, 30B third guide geometry 34 and formed on the pole core 30A, 30B fourth guide geometry 35 cooperates. The third guide geometry 34 and the fourth guide geometry 35 are formed in the recess 36A, 36B of the main body 32A, 32B of the pole core 30A, 30B. At the other end of the ram 40A,

40B, the closing element 48 is formed, which forms the tip of the plunger 40A, 40B and cooperates with the valve seat 15.1 to exercise the sealing function. In the illustrated embodiment, the plunger 40A, 40B is designed as a plastic injection molded part. Alternatively, the plunger 40A, 40B can be made in a PIM, CIM or MIM process or as a 3D printing part. In addition, a sealing element can be arranged on the closing element 48 in order to improve the sealing effect in the valve seat 15.1.

The valve anchor 20A, 20B has in the illustrated embodiments a stepped cylindrical body 22A, 22B with two different outer diameters. In this case, a section of the base body 22A, 22B which dips into the recess 36A, 36B of the pole core 30A, 30B has a fifth guide geometry 26 which, when axially moved with the third guide geometry 34 in the recess 36A, 36B of the main body 32A, 32 B of the pole core 30 A, 30 B cooperates. Due to the requirement of magnetic

Conductivity is the valve armature 20A, 20B made in the illustrated embodiments of magnetically conductive metal in the cold impact method or by machining.

The first guide geometry 46 comprises a plurality of projections 46.1 in uniform pitch on the circumference of the main body 42A, 42B of the plunger 40A, 40B, each having a one-sided bevel 46.2 and in the axial movement in the direction of pole core 30A, 30B on the second guide geometry 27 of the valve armature 20A, 20B support. The second guide geometry 27 comprises at the edge of the passage opening 24A, 24B introduced in uniform angular pitch Ankernuten 27.1 with two-sided chamfers 27.2, which are adapted to the one-sided chamfers 46.2 of the formations 46.1 of the plunger 40A, 40B. As can also be seen from FIG. 8, in the exemplary embodiments illustrated, eight formations 46.1 are each formed on the base body 42A, 42B of the plunger 40A, 40B with an angular separation of 8 × 45 °. As is further apparent from FIGS. 3 and 8, sixteen armature grooves 27.1 with two-sided chamfers 27.2 having a 16 × 22.5 ° angular pitch are formed in each case at the edge of the passage openings 24A, 24B in the exemplary embodiments illustrated. As can also be seen from FIG. 4, the unilateral bevels 46.2 rest against a chamfer 27.2 of corresponding armature slots 27.

The third guide geometry 34 of the pole core 30A, 30B has on the wall of the recess 36A, 36B in a uniform angular pitch axial grooves 34.1, 34.2 with at least two different depths in the radial direction. As is further apparent from FIG. 7, sixteen axial grooves 34.1, 34.2 are arranged on the wall of the recess 36A, 36B with an angular pitch of 16 × 22.5 °, with each fourth designed as a flat axial groove 34.2 with a smaller depth in the radial direction is. This means that the flat axial grooves 34.2 have an angular pitch of 4 × 90 °. The fourth guide geometry 35 of the pole core 30A, 30B has one-sided chamfers 35.2 at intermediate webs 35.1 of the axial grooves

34.1, 34.2, which are adapted to the one-sided bevels 46.2 of the formations 46.1 of the plunger 40A, 40B. The one-sided bevels 35.2 on the intermediate webs 35.1 guide the formations 46.1 of the plunger 40A, 40B when changing the plunger 40A, 40B between the two de-energized positions on the one-sided bevels 46.2 in the corresponding axial groove 34.1.

34.2. As can also be seen from FIG. 8, four of the eight formations 46.1 of the plunger 40A, 40B lie in flat axial grooves 34.2 in the exemplary embodiment shown. Here are the bevels 46.2 of the formations 46.1 of the plunger 40A, 40B to second bevels 34.3, which are formed on the edge of flatter Axialnuten 34.2. Therefore, the plunger 40A, 40B in the axial detent position and in the de-energized open position. In the de-energized closed position, not shown, all the formations 46.1 of the plunger 40A, 40B are each guided in an axial groove 34.1 which is deeper in the radial directions and can be moved by the restoring spring 16A, 16B as far as the stop of the closing element

48 are moved in the valve seat 15.1.

The fifth guide geometry 26 on the main body 22A, 22B of the valve armature 20A, 20B comprises radial guide webs 26.1, which are guided axially in corresponding axial grooves 34.1, 34.2 of the pole core 30A, 30B. As can also be seen from FIG. 7, eight radial guide webs 26.1 each having an angular pitch of 8 × 45 ° are formed on the base body 22A, 22B of the valve anchor 20A, 20B in the exemplary embodiments shown. The height of the guide webs

26.1 is adapted to the depth of the flat axial grooves 34.2, so that the guide webs 26.1 can be axially guided in all axial grooves 34.1, 34.2. Thus, the guide webs 26.1 of the valve armature 20A, 20B constantly run in the axial grooves 34.1, 34.2 of the pole core 30A, 30B, while the formations 46.1 of the plunger 40A, 40B in dependence on the rotational position in the axial grooves 34.1,

34.2 of the pole core 30A, 30B can run.

In the closed position, the formations 46.1 of the plunger 40A, 40B are guided in the lower axial grooves 34.1 of the pole core 30A, 30B. If, due to electromagnetic action, the valve armature 20A, 20B is attracted axially to the immobile pole core 30A, 30B, then the valve armature 20A, 20B, with its pinch grooves 27.1, carries along the plunger 40A, 40B via its formations 46.1. By the chamfers 27.2 of the Ankernuten 27.1 and the formations 46.1 of the plunger 40A, 40B is applied to the plunger 40A, 40B in this lifting movement, a circumferential force which tries to rotate the plunger 40A, 40B about its longitudinal axis. However, this rotational movement is initially prevented by the simultaneous axial guidance of the formations 46.1, which initially permits only a purely axial movement of the plunger 40A, 40B in the axial grooves 34.1, 34.2 of the pole core 30A, 30B. The rotational movement is also prevented by an axial guide between the valve armature 20A, 20B and pole core 30A, 30B, since the radial guide webs 26.1 are also guided in the axial grooves 34.1, 34.2 of the pole core 30A, 30B. Only when the plunger 40A, 40B exceeds a certain axial stroke, the radial guidance of the formations 46.1 of the plunger 40A, 40B in the axial grooves 34.1, 34.2 of the pole core 30A, 30B is exceeded and the formations 46.1 of the plunger 40A, 40B slip due to the still acting Peripheral force axially even slightly deeper in the Ankernuten 27.1 (peak in peak). As a result, the plunger 40A, 40B is now prevented from further rotation. If the axial stroke of the valve armature 20A, 20B and of the plunger 40A, 40B is subsequently reduced by the force of the return spring 16A, 16B, the formations 46.1 of the plunger 40A, 40B with their bevels 46.2 find their way into the respective next axial groove 34.1, 34.2 of the pole core 30A, 30B and follow this new guidance by a rotational movement. The formations 46.1 of the plunger 40A, 40B also slip into the next anchoring groove 27.1. The axial grooves 34.1, 34.2 of the pole core 30A, 30B are shaped differently in their radial propagation. Now slide at least two protrusions 46.1 of the plunger 40A, 40B, as described above, each in a shallower axial groove 34.2 of the pole core 30A, 30B, so the plunger 40A, 40B to the decreasing

Anchor stroke no longer follow, but remains locked in the detent position, clearly positioned by tip-top and secured by the still closing acting return spring 16A, 16B. Here are the bevels 46.2 of the formations 46.1 of the plunger 40A, 40B at the second bevels 34.3, which are formed on the edge of flatter Axialnuten 34.2.

During the next valve actuation, the valve armature 20A, 20B again moves axially in the direction of the pole core 30A, 30B and, after touching the bevels 27.2 of the armature grooves 27.1 with the formations 46.1, entrains the plunger 40A, 40B. As already stated above, the plunger 40A, 40B can still Do not turn the circumferential force until the specified axial stroke is reached. With the exceeding of the determined Axialhubs the plunger 40A, 40B again rotates deeper into the Ankernuten 27.1 (tip in tip). As a result, the plunger 40A, 40B is now prevented from further rotation. If the axial stroke of the valve anchor 20A, 20B and the plunger 40A, 40B by the force of the return spring

16A, 16B subsequently reduced, find the formations 46.1 of the plunger 40A, 40B with their bevels 46.2 in the next axial groove 34.1, 34.2 of the pole core 30A, 30B and follow this new leadership by a rotational movement. The formations 46.1 of the plunger 40A, 40B also slip into the next anchoring groove 27.1. Since now all the formations 46.1 of the plunger

40A, 40B are each introduced into a deeper axial groove 34.1, the formations 46.1 continue to travel into the deeper axial grooves 34.1 without limitation until the closing element 48 seals in the valve seat 15.1 and the plunger 40A, 40B has returned to the de-energized closed position.

In an air gap 12 between a first pole face 28A, 28B of the valve armature 20A, 20B and a second pole face 38A, 38B of the pole core 30A, 30B, a second return spring can be arranged which moves the valve armature 20A, 20B in the direction of the valve seat 15.1. This additional closing-acting restoring spring is preferably designed as a very spring-soft pressure spring and prevents an undefined position of the valve armature 20A, 20B. The abovementioned numbers and angular graduations of the various formations 46. 1, webs 26. 1, 35. 1 and / or grooves 27. 1, 34. 1, 34. 2 as well as the respective helical angles can be correspondingly changed and adapted to the dimensions of the magnetic valve 10 A, 10 B in order to produce a conventional magnetic axial Air gap to approach the various stroke positions at reasonably existing magnetic force.

As is further apparent from FIG. 1, in the illustrated first exemplary embodiment of the solenoid valve 10A, the return spring 16A is guided in a spring receptacle 43 in the main body 42A of the plunger 40A, designed as a recess. The spring receptacle 43 extends at the same height as the further outward formations 46.1 of the plunger 40A and the axial grooves 34.1, 34.2 of the pole core 30A. The return spring 16A is supported at the bottom of the spring receptacle 43 and at the bottom of the recess 36A in the main body 32A of the pole core 30A. 9, the return spring 16B in the illustrated second embodiment of the solenoid valve 10 B is not arranged in a recess exactly at the same height as the further outward formations 46.1 of the plunger 40B and the axial grooves 34.1, 34.2 of the pole core 30B but on an end face of the plunger 40B. As a result, the return spring 16B is supported on a spring support 44, which is arranged on the end face of the main body 42B of the plunger 40B. In addition, at the bottom of the recess 36B in the base body 32B of the pole core 30B a blind hole is introduced, which at least partially receives the return spring 16B. Therefore, the return spring 16B is supported in the illustrated embodiment at the bottom of the blind hole. Without blind hole, the return spring 16B is supported directly on the bottom of the recess 36B in the main body 32B of the pole core 30B. By this embodiment, the base body 42B of the plunger 40B can be made thinner, and also the guide geometries 26, 34, 35 of the valve armature 20B and the pole core 30B can move inward. As a result, larger magnetically effective pole faces 28B, 38B are available between valve anchor 20B and pole core 30B.

In an alternative embodiment, not shown, the pole core 30A, 30B is made of several parts, wherein the magnetically active body 32A, 32B of the pole core 30A, 30B has a first cylindrical part and a second tubular part, wherein in the tubular part, a plastic injection molded part, which the third guide geometry 34 and the fourth guide geometry 35 has.

In a further alternative embodiment, not shown, the valve anchor 20A, 20B is made in several parts, wherein the in the recess 36A, 36B of the pole core 30A, 30B dipping portion of the base body 22A, 22B of the valve armature 20A, 20B as a plastic injection molded part and the outside of the pole core 30A 30B arranged portion of the base body 22A, 22B is designed as a magnetically active metal part.

Claims

Solenoid valve (10A, 10B) for a hydraulic brake system (1), with a magnet assembly, a pole core (30A, 30B), a guide sleeve (13) connected to the pole core (30A, 30B), an axially movable within the guide sleeve (13). guided valve armature (20A, 20B), which can be driven by a magnetic force generated by the magnet assembly against the force of a return spring (16A, 16B) or by the force of the return spring (16A, 16B) and a plunger (40A, 40B) with a closing element (48) moves axially, and a valve body (15) connected to the guide sleeve (13) with a valve seat (15.1), which is arranged between at least one first flow opening (15.2) and at least one second flow opening (15.3), characterized in that the plunger (40A, 40B) is mounted axially movably in the valve armature (20A, 20B), a mechanical locking device (18) being formed between the pole core (30A, 30B) and the plunger (40A, 40B), which holds the plunger (40A , 40B) in a de-energized closed position, so that the return spring (16A, 16B) presses the closing element (48) sealingly into the valve seat (15.1) to perform a sealing function, and the plunger (40 A, 40 B) in a de-energized open position against the force of the return spring (16A, 16B) in an axial locking position so that the closing element (48) is lifted from the valve seat (15.1).

Solenoid valve according to claim 1, characterized in that the mechanical locking device (18) is designed as a rotary cam mechanism which uses a circumferential force component to move the plunger (40A, 40B) with the closing element (48) axially into the locking position and out again, so that the closing element (48) switches between the two de-energized positions by applying a switching signal to the magnet assembly.

Solenoid valve according to claim 2, characterized in that at the end facing the valve armature (20A, 20B) a cylindrical recess (36A, 36B) is introduced into a base body (32A, 32B) of the pole core (30A, 30B), which forms the plunger (40A, 40B) and the valve armature (20A, 20B), the return spring (16A, 16B) being arranged in the recess (36A, 36B) and between the pole core (30A, 30B) and the plunger (40A, 40B). ). the return spring (16A, 16B) can be moved towards the valve seat (15.1).

Solenoid valve according to claim 3, characterized in that the plunger (40A, 40B) has a cylindrical base body (42A, 42B), at one end of which a first guide geometry (46) is formed, which during axial movement with one on the base body (22A , 22B) of the valve armature (20A, 20B) formed second guide geometry (27) and a third guide geometry (34) formed on the pole core (30A, 30B) and a fourth guide geometry (35) formed on the pole core (30A, 30B), which in the recess (36A, 36 B) of the base body (32 A, 32 B) of the pole core (30 A, 30 B) are formed.

Solenoid valve according to claim 3 or 4, characterized in that the valve armature (20A, 20B) has a stepped cylindrical base body (22A, 22B) with two different outer diameters, one being inserted into the recess (36A, 36B) of the pole core (30A, 30B). Immersed section of the base body (22A, 22B) of the valve armature (20A, 20B) has a fifth guide geometry (26), which during an axial movement with the third guide geometry (34) in the recess (36A, 36B) of the base body (32A, 32B ) of the pole core (30A, 30B) cooperates, the valve armature (20A, 20B) being guided radially on an inner wall of the guide sleeve (13) by a section of the base body (22A, 22B) arranged outside the pole core (30A, 30B).

Solenoid valve according to claim 4 or 5, characterized in that the first guide geometry (46) comprises a plurality of formations (46.1) evenly spaced on the circumference of the base body (42A, 42B) of the plunger (40A, 40B), each of which has a one-sided bevel (46.2 ) and are supported during the axial movement in the direction of the pole core (30A, 30B) on the second guide geometry (27) of the valve armature (20A, 20B), which has anchor grooves (27.1) made at a uniform angular pitch on the edge of the through opening (24A, 24B). with two-sided bevels (27.2), which are adapted to the one-sided bevels (46.2) of the formations (46.1) of the plunger (40A, 40B).

Solenoid valve according to claim 6, characterized in that the third guide geometry (34) of the pole core (30A, 30B) has axial grooves (34.1, 34.2) with at least two different depths in the radial direction at a uniform angular pitch on the wall of the recess (36A, 36B). , wherein the fifth guide geometry (26) on the base body (22A, 22 B) of the valve armature (20A, 20B) comprises radial guide webs (26.1), which are guided axially in corresponding axial grooves (34.1, 34.2) of the pole core (30A, 30B), and wherein the fourth guide geometry (35) of the pole core (30A, 30B) has one-sided bevels (35.2) on intermediate webs (35.1) of the axial grooves (34.1, 34.2), which are connected to the one-sided bevels (46.2) of the formations (46.1) of the plunger ( 40A, 40B).

Solenoid valve according to claim 7, characterized in that the valve armature (20A, 20B) via its armature grooves (27.1) pushes the plunger (40A, 40B) via its formations (46.1) during an axial movement in the direction of the pole core (30A, 30B) caused by the magnetic force of the magnet assembly ). 40A, 40B), which attempts to rotate the plunger (40A, 40B) about its longitudinal axis, with the simultaneous guidance of the formations (46.1) of the plunger (40A, 40B) and/or the radial guide webs (26.1) of the valve armature (20A, 20B) in the axial grooves (34.1, 34.2) of the pole core (30A, 30B) prevents this rotational movement until the plunger (40A, 40B) reaches a predetermined axial stroke and the formations ( 46.1) of the plunger (40A, 40B) leave the axial grooves (34.1, 34.2) of the pole core (30A, 30B) and slide deeper into the anchor grooves (27.1) due to the circumferential force that is still acting, with the formations (46.1) of the plunger (40A , 40B) slip into the next axial grooves (34.1, 34.2) of the pole core (30A, 30B) and follow the new guide through a radial movement when the axial stroke of the valve armature (20A, 20B) and the plunger (40A, 40B) due to the acting spring force of the return spring (16A, 16B) is reduced, with the formations (46.1) of the plunger (40A, 40B) simultaneously slipping into the next anchor groove (27.1).

Solenoid valve according to claim 8, characterized in that in the de-energized open position at least two formations (46.1) of the plunger (40A, 40B) are each held axially in an axial groove (34.2) which is flatter in the radial direction, with all formations (46.1 ) of the plunger (40A, 40B) are each guided in an axial groove (34.1) which is deeper in the radial directions up to the stop of the closing element (48) in the valve seat (15.1).

Solenoid valve according to one of claims 1 to 9, characterized in that in an air gap (12) between a first pole surface (28A, 28B) of the valve armature (20A, 20B) and a second pole surface (38A, 38B) of the pole core (30A, 30B ) a second return spring is arranged, which moves the valve armature (20A, 20B) towards the valve seat (15.1).

Solenoid valve according to one of claims 3 to 10, characterized in that the return spring (16A) is guided in a spring receptacle (43) designed as a recess in the base body (42A) of the plunger (40A) and is located on the bottom of the spring receptacle (43) and on Bottom of the recess (36A, 36B) in the base body (32A) of the pole core (30A) is supported.

12. Solenoid valve according to one of claims 3 to 10, characterized in that the return spring (16B) is located on a spring support (44), which is arranged on an end face of the base body (42B) of the plunger (40B), and on the bottom of the Recess (36B) in the base body (32B) of the pole core (30B) is supported.

13. Solenoid valve according to claim 12, characterized in that a blind hole is made at the bottom of the recess (36B) in the base body (32B) of the pole core (30B), which at least partially accommodates the return spring (16B).

14. Solenoid valve according to one of claims 4 to 13, characterized in that the pole core (30A, 30B) is designed in several parts, the base body (32A, 32B) of the pole core (30A, 30B) being magnetically effective and a first cylindrical Part and a second tubular part, a plastic injection molded part being pressed into the tubular part, which has the third guide geometry (34) and the fourth guide geometry (35).

15. Solenoid valve according to one of claims 5 to 14, characterized in that the valve armature (20A, 20B) is designed in several parts, the section of the base body (22A) which dips into the recess (36A, 36B) of the pole core (30A, 30B). 22B) of the valve armature (20A, 20B) is designed as a plastic injection-molded part and the section of the base body (22 A, 22 B) arranged outside the pole core (30A, 30B) is designed as a magnetically effective metal part.

16. Hydraulic brake system (1) for a vehicle, with a master brake cylinder (5), a hydraulic unit (9) and several wheel brakes (RR, FL, FR, RL), the hydraulic unit (9) having at least two

Brake circuits (BCl, BC2) for brake pressure modulation in the wheel brakes (RR, FL, FR, RL), characterized in that the at least two brake circuits (BCl, BC2) each have at least one bistable solenoid valve (10A, 10B), which according to at least one of claims 1 to 15 is carried out and in the de-energized open position releases the brake pressure modulation in at least one assigned wheel brake (RR, FL, FR, RL) and in the de-energized closed position includes a current brake pressure in the at least one assigned wheel brake (RR, FL, FR, RL).