GB2623479A - Bi-stable circuit split valve CSV, brake system including bi-stable circuit split valve CSV, and method of using thereof - Google Patents
Bi-stable circuit split valve CSV, brake system including bi-stable circuit split valve CSV, and method of using thereof Download PDFInfo
- Publication number
- GB2623479A GB2623479A GB2211570.3A GB202211570A GB2623479A GB 2623479 A GB2623479 A GB 2623479A GB 202211570 A GB202211570 A GB 202211570A GB 2623479 A GB2623479 A GB 2623479A
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- United Kingdom
- Prior art keywords
- valve
- csv
- plunger
- stable circuit
- circuit split
- Prior art date
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- Pending
Links
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- 239000012530 fluid Substances 0.000 claims abstract description 58
- 230000005294 ferromagnetic effect Effects 0.000 claims abstract description 47
- 230000005291 magnetic effect Effects 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 4
- 238000004026 adhesive bonding Methods 0.000 claims description 2
- 229910000828 alnico Inorganic materials 0.000 claims description 2
- 229910000938 samarium–cobalt magnet Inorganic materials 0.000 claims description 2
- 229910000859 α-Fe Inorganic materials 0.000 claims description 2
- 229910052779 Neodymium Inorganic materials 0.000 claims 1
- KPLQYGBQNPPQGA-UHFFFAOYSA-N cobalt samarium Chemical compound [Co].[Sm] KPLQYGBQNPPQGA-UHFFFAOYSA-N 0.000 claims 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 230000001133 acceleration Effects 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- GHOKWGTUZJEAQD-ZETCQYMHSA-N (D)-(+)-Pantothenic acid Chemical compound OCC(C)(C)[C@@H](O)C(=O)NCCC(O)=O GHOKWGTUZJEAQD-ZETCQYMHSA-N 0.000 description 1
- 229910000521 B alloy Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- 229910000583 Nd alloy Inorganic materials 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910001172 neodymium magnet Inorganic materials 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K31/00—Actuating devices; Operating means; Releasing devices
- F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
- F16K31/06—Actuating devices; Operating means; Releasing devices electric; magnetic using a magnet, e.g. diaphragm valves, cutting off by means of a liquid
- F16K31/0644—One-way valve
- F16K31/0655—Lift valves
- F16K31/0665—Lift valves with valve member being at least partially ball-shaped
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
- B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
- B60T11/28—Valves specially adapted therefor
- B60T11/32—Automatic cut-off valves for defective pipes
- B60T11/323—Automatic cut-off valves for defective pipes in hydraulic systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/662—Electrical control in fluid-pressure brake systems characterised by specified functions of the control system components
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/66—Electrical control in fluid-pressure brake systems
- B60T13/68—Electrical control in fluid-pressure brake systems by electrically-controlled valves
- B60T13/686—Electrical control in fluid-pressure brake systems by electrically-controlled valves in hydraulic systems or parts thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
- B60T17/18—Safety devices; Monitoring
- B60T17/22—Devices for monitoring or checking brake systems; Signal devices
- B60T17/221—Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K27/00—Construction of housing; Use of materials therefor
- F16K27/02—Construction of housing; Use of materials therefor of lift valves
- F16K27/029—Electromagnetically actuated valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K31/00—Actuating devices; Operating means; Releasing devices
- F16K31/003—Actuating devices; Operating means; Releasing devices operated without a stable intermediate position, e.g. with snap action
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K31/00—Actuating devices; Operating means; Releasing devices
- F16K31/02—Actuating devices; Operating means; Releasing devices electric; magnetic
- F16K31/06—Actuating devices; Operating means; Releasing devices electric; magnetic using a magnet, e.g. diaphragm valves, cutting off by means of a liquid
- F16K31/08—Actuating devices; Operating means; Releasing devices electric; magnetic using a magnet, e.g. diaphragm valves, cutting off by means of a liquid using a permanent magnet
- F16K31/082—Actuating devices; Operating means; Releasing devices electric; magnetic using a magnet, e.g. diaphragm valves, cutting off by means of a liquid using a permanent magnet using a electromagnet and a permanent magnet
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T2270/00—Further aspects of brake control systems not otherwise provided for
- B60T2270/40—Failsafe aspects of brake control systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K2200/00—Details of valves
- F16K2200/50—Self-contained valve assemblies
- F16K2200/501—Cartridge valves
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Transportation (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
- Magnetically Actuated Valves (AREA)
Abstract
A bi-stable circuit split valve for a brake system – for example for hydraulically separating the main brake circuit into two separate brake circuits. The valve comprising a valve housing 1; a ferromagnetic armature 3; a valve body 5 with a central through bore 5.2, and a central cavity 5.1 for return spring 7; a valve closing element 9 with a central cavity 9.1 for valve seat 4; a plunger 2 mounted in the armature 3 and valve body bore 5.2; a solenoid coil 6; and a permanent magnet 8 mounted to the plunger 2 and armature 3. When no current is applied, the return spring 7 holds the valve open. When current is applied to the solenoid coil, this drives the plunger to engage with the valve seat and hence close the valve. Once closed, the permanent magnet 8 is able to hold the valve closed when the coil is de-energised. Also claimed is a method involving closing the valve in response to a warning of low brake fluid level, for example due to a leak; and reopening the valve by applying current to the solenoid in the opposite direction.
Description
Bi-stable circuit split valve CSV, brake system including bi-stable circuit split valve CSV, and method of using thereof
Field of the invention
This invention generally relates to brake systems for vehicles. More particularly, this invention relates to a bi-stable circuit split valve CSV for automatically "locking" the leaking portion of the hydraulic brake circuit generating braking fluid loss, in order to avoid additional loss of braking fluid during the time between the loss occurred and servicing so as to maintain the braking ability of the vehicle, and method of using thereof.
Terms to be used in the invention Throughout this invention the following terms have the following corresponding meanings: - CSV valve -Circuit Split Valve is a valve used in the brake system to hydraulically separate the main brake circuit in two different brake circuits, each having its own actuator for hydraulic pressure build up for redundancy. The separation of the circuits is done either front to back with one hydraulic brake circuit designed for the front wheels, and the one hydraulic brake circuit for the rear wheels, or with diagonal split, according to vehicle configuration.
Background of the invention
The brake system has valves and valve assemblies for brake pressure modulation, which are associated with brake lines, and a pump for pumping pressure fluid, drawn from wheel brakes, into a brake line.
The brake system also has a reservoir connected to the brake lines, providing the necessary amount of braking fluid for the brake system. The reservoir has two settled levels, namely a nominal level SLO corresponding to the normal amount of braking fluid, and a warning level SL1, when the amount of braking fluid is low.
In case the car is parked for a long time and a small leak develops during this time either on the rear pair or the front pair of wheels, the system wakes up with a SL1 warning. This causes loss of possibility of the brake system to achieve full brake performance.
A more significant damage may occur if the leak affects the rear pair of wheels, due to the substantial amount of fluid contained in its braking lines, which may be lost during a long-time parking, in this case the level of braking fluid in the Master Cylinder being low. For such case it is provided a CSV valve, having a normal opened position.
In case that a leak occurred on the rear pair of wheels, the CSV valve is closed in order to maintain the braking function on the front pair of wheels.
The standard proceeding when a leak occurs in the rear circuit is as follows: Issuing by the sensor level of a warning signal to a processing unit at system wake up, when it detects a low level of braking fluid, corresponding to the warning level SL1; Transmitting the warning signal to a display, informing the driver that an emergency service intervention is necessary; Issuing by the processing unit of an electrical signal which determines the solenoid coil of the CSV valve to generate a magnetic field that closes the CSV valve, in this way interrupting the supply with braking fluid in the rear wheels circuit.
After closing the CSV valve, the brake system continues to work normally on the front wheels, namely braking by driver pedal, and FSI on the rear wheels (fall-back support by IPB -Integrated Parking Brake).
Given that braking by driver pedal still applies on the front wheels, during pedal release more air is drawn into the system from the empty part of the MC reservoir chamber, it causing further degradation of the braking performance.
The CSV valve is maintained closed by the solenoid coil that is energised as long as the engine is awake. After engine shut off the CSV valve can be operated for a limited period of time, depending on the battery condition. When the engine is turned off, the solenoid coil of the CSV valve uses energy from the battery of the vehicle. Accordingly, in case of a weak battery the solenoid coil may be de-energised and the CSV valve may open, thus a further loss of braking fluid occurring.
On the other hand, even if the CSV valve remains closed during turn off period, 30 when the system wakes up a routine checking is performed and the brake fluid from the non-leaking wheel circuit is placed in the leaking rear wheel circuit and more fluid being lost.
All these facts may lead to failures of the braking system.
Disadvantages of prior art
-short or impaired driving availability of the vehicle in case of system wakeup with SL1 warning with a front or rear wheel leak condition.
Problem to be solved by the invention The technical problem to be solved by the invention is preventing the additional loss of brake fluid in case of a weak battery condition, a battery disconnection or a complete power loss, when a rear wheel leak or other fault of the brake system which requires activation of the CSV valve appeared.
Summary of the invention
In order to overcome the disadvantages of prior art, in a first aspect of the invention it is presented a bi-stable circuit split valve CSV for a brake system of a vehicle, the bi-stable circuit split valve CSV having a central axis, the bi-stable circuit split valve CSV comprising a brake fluid inlet and a brake fluid outlet for communicating with the brake system for passaging of a fluid under pressure therethrough, the bistable circuit split valve CSV further comprising: - a valve house having an valve house opening portion; -a ferromagnetic armature based within said valve house having a central bore; - a valve body mounted on said ferromagnetic armature, positioned at valve house opening portion, said valve body having a valve body central cavity extending along the central axis, faced toward the ferromagnetic armature, configured to receive a return spring, and a valve body central through bore extending along the central axis in line with the valve body central cavity; - a valve closing element joining with said valve body, said valve closing element comprising a valve closing element central cavity extending along the central axis faced towards the valve body, said valve closing element central cavity being configured to receive a valve seat to be centrally placed within the valve closing element central cavity; - a plunger that is centrally mounted within central bore of the ferromagnetic armature in axial alignment with a longitudinal axis of said valve seat corresponding to the central axis, accommodated within the valve body central through bore protruding said valve closing element central cavity and said valve closing element central cavity to engage with said valve seat, said plunger being axially movable within the valve body along the central axis between two predetermined positions in respect to said valve seat corresponding to an open position and a closed position of the bi-stable circuit split valve CSV, the said open position being defined by a spaced positioning of the plunger in respect to said valve seat, creating a fluid passage connecting said brake fluid inlet with said brake fluid outlet of the bi-stable circuit split valve CSV, and said closed position being defined by engagement of the plunger with said valve seat; - a solenoid coil mounted around said valve house, generating a electromagnetic force corresponding to an electric current applied to said solenoid coil configured for driving said plunger together with the ferromagnetic armature from said open position to said closed position; - said return spring being mounted around said plunger on the ferromagnetic armature within the valve body, said return spring having an elastic force configured for driving said plunger together with the ferromagnetic armature from said closed position to said open position when no current is applied to said solenoid coil, wherein said bi-stable circuit split valve CSV valve further comprises a permanent magnet mounted as one piece together with said plunger and with the ferromagnetic armature, said permanent magnet having a magnetic force, wherein the magnetic force of said permanent magnet is greater than the elastic force of the return spring, such that to maintain-said plunger together with the ferromagnetic armature on said closed position when no current is applied to said solenoid coil.
In a second aspect of the invention it is provided a brake system of a vehicle with a pair of front wheels and a pair of rear wheels wherein it comprises the bi-stable circuit split valve CSV valve according to any of the preceding claims.
In a third aspect of the invention it is provided a method of use of the bi-stable circuit split valve CSV valve wherein the pressurized brake fluid inlet is communicating with a brake fluid reservoir line and said pressurized brake fluid outlet is communicating with a brake fluid wheels line, the method comprising the following steps: - receiving a warning signal from the level sensor by a processing unit of a brake fluid reservoir when at least one sensor of the braking system, including the brake fluid level sensor, detect a specific level of braking fluid SL1; - sending corresponding instructions by the processing unit to the electrical unit of the brake system to close the bi-stable circuit split valve CSV; -applying a first electrical signal by the electrical unit of the brake system to said solenoid coil for driving said plunger together with the ferromagnetic armature from said open position to said closed position of the bi-stable circuit split valve CSV; said first electrical signal having the same polarity as the polarity of the permanent magnet; -maintaining said plunger by the permanent magnet together with the ferromagnetic armature on said closed position of the bi-stable circuit split valve CSV for a predetermined period of time; - sending corresponding instructions by the processing unit to the electrical unit of the brake system to open the bi-stable circuit split valve CSV when the sensors existing in the brake system, including the brake fluid level sensor, detect a specific level of braking fluid SLO; - applying a second electrical signal by the electrical unit of the brake system to said solenoid coil for driving said plunger together with the ferromagnetic armature from said closed position to said open position of the bi-stable circuit split valve CSV; said second electrical signal having opposite polarity in respect to the polarity of the permanent magnet.
Advantages The main advantages of using the invention are as follows: -The bi-stable circuit split valve CSV makes possible holding the valve in closed position without powering the valve coil. This makes it stable in the closed position in case of weak battery condition, battery disconnection or complete power loss; - The bi-stable circuit split valve CSV prolongs indefinitely the available drive time until service in the case of rear wheel leak or other fault which requires activation of the CSV valve; - The bi-stable circuit split valve CSV is plug and play in the current HCU architecture since no new interface or routing of hydraulic channels inside the HCU is needed; - The complexity of the SW implementation required to implement bi-stable circuit split valve CSV is resumed only to the operation of a different valve driver; - Ultimately, using the CSV valve according to invention prolongs the time for which the vehicle can still be operated safely.
List of drawings Further special features and advantages of the present invention can be taken from the following description of an advantageous embodiment by way of the accompanying drawings: Fig. 1A illustrates a MKC2 RP (remote PAU) by wire brake system; Fig. 1B illustrates a MKC2 One box brake by wire system; Fig. 2 A depicts MKC2 RP system wake up with SL1 and rear wheel leak; Fig. 2B depicts a MKC2 system wake up with SL1 and rear wheel leak; Fig. 3 illustrates a bi-stable circuit split valve CSV according to the invention.
Detailed description
The purpose of a bi-stable circuit split valve CSV is to able to park the valve in its closed position without requiring to continuously power the solenoid coil of the valve once the system has detected a condition for which the CSV valve needs to be closed before the system can go to sleep, and mitigate a situation as described above where after a rear wheel leak condition resulting in an empty MC reservoir chamber, the system cannot prevent additional loss of brake fluid, in the end resulting in loss of braking ability.
The proposed solution consists of a bi-stable circuit split valve CSV design as depicted in the Fig.3 having an open position and a closed position, wherein both positions can be maintained when the solenoid coil of the valve is not energized. In open position the braking fluid is allowed to pass through the valve, while in closed position it is blocked.
The bi-stable circuit split valve CSV has a central axis CA.
The bi-stable circuit split valve CSV comprises a valve house 1 having a valve house opening portion 1.1, a ferromagnetic armature 3 based within said valve house 1, and a valve body 5 mounted on said ferromagnetic armature 3, positioned at the valve house opening portion 1.1.
The valve body 5 has a valve body central cavity 5.1 extending along the central axis CA. The valve body central cavity 5.1 is faced toward the ferromagnetic armature 3, and it is configured to receive a return spring 7.
The valve body 5 further has a valve body central through bore 5.2 extending along the central axis CA, in line with the valve body central cavity 5.1.
The bi-stable circuit split valve CSV further comprises a valve closing element 9 joining with the valve body 5. The valve closing element 9 comprises a valve closing element central cavity 9.1 along the central axis CA, configured to receive a valve seat 4 centrally placed within the valve closing element central cavity 9.1.
The bi-stable circuit split valve CSV further comprises a plunger 2 that is centrally fixed within the ferromagnetic armature 3, in axial alignment with a longitudinal axis of the valve seat 4 corresponding to the central axis CA. The plunger 2 is accommodated within the valve body central through bore 5.2. Said plunger 2, together with the ferromagnetic armature 3, can move along the central axis CA, so that the plunger 2 moves within the valve body 5 between two predetermined positions in respect to said valve seat 4. The first is an open position of the bi-stable circuit split valve CSV, defined by the plunger 2 spaced from said valve seat 4, creating a fluid passage connecting said brake fluid inlet with said brake fluid outlet of the bi-stable circuit split valve CSV. The second is a closed position of the bi-stable circuit split valve CSV, defined by engagement of the plunger 2 with said valve seat 4.
In Figure 3 is represented the bi-stable circuit split valve CSV according to invention, in closed position, an arrow indicating the fluid passage connecting the brake fluid inlet with the brake fluid outlet.
The bi-stable circuit split valve CSV further comprises a solenoid coil 6, mounted around the valve house 1. When an electric current is applied to the solenoid coil 6, it generates a magnetic force that moves the plunger 2 together with the ferromagnetic armature 3.
The return spring 7 is accommodated by the valve body cavity 5.1. The return spring 7 is mounted around said plunger 2 on the ferromagnetic armature 3 within the valve body 5. The return spring 7 is characterized by an elastic force. Said elastic force can move said plunger 2 together with the ferromagnetic armature 3, opening the valve when no current is applied to the solenoid coil 6.
The bi-stable circuit split valve CSV further comprises a permanent magnet 8 mounted as one piece together with said plunger 2 and with the ferromagnetic armature 3, said permanent magnet 8 being characterized by a magnetic force. The magnetic force of the permanent magnet 8 is greater than the elastic force of the return spring 7, such that to maintain said plunger 2 together with the ferromagnetic armature 3 on closed position when no current is applied to said solenoid coil 6.
The bi-stable circuit split valve CSV has the normal open position.
The permanent magnet 8 is configured to provide a constant magnetic force, not enough to move the ferromagnetic armature 3 on its own due to the elastic force of the return spring 4, the normal position of the concerned valve being open. When applying a current of the same polarity with the magnetic force of the permanent magnet 8, the solenoid coil 6 generates an electromagnetic force that moves the ferromagnetic armature 3 together with the plunger 2, closing the bi-stable circuit split valve CSV. When the current is removed, the permanent magnet 8 holds the ferromagnetic armature 3, the bi-stable circuit split valve CSV being maintained in closed position. If an opposite current is applied, the magnetic force of the permanent magnet 8 is compensated by the electromagnetic force of the solenoid coil 6, and the ferromagnetic armature 3 is moved together with the plunger 2, opening the bi-stable circuit split valve CSV.
In order carry out the above functions, the permanent magnet is dimensioned in relation to the working conditions of the bi-stable valve CSV. Temperature, environmental conditions, the material being attracted (size, quality, shape, permeability, etc.) all impact on the magnet performance, as does the distance between the magnet and the material being attracted.
Accordingly, when designing the permanent magnet, in a specific embodiment of the invention if strong magnets are required, there are used the so-called "neodymium magnets", which are made from an alloy of neodymium, iron and boron (NdFeb) or "samarium cobalt magnets" that are made from samarium, cobalt and small amounts of iron, copper and other materials. In other embodiments other types of permanent magnets are used, these including "ferrite magnets", made from a compound of ceramic material and iron oxide (Sr0.6Fe203) or "alnico magnets" made from aluminium, nickel and cobalt or "flexible rubber'', used for a lower magnetic force required.
The size and shape of a magnet also affect the magnetic field output and also its maximum possible pull force (holding force).
Magnetic pull force general formula is: F = m x a, wherein "F" is the force required to move an object, "m" refers to the mass of the object, and "a" stands for acceleration. So force = mass multiplied by acceleration.
The permanent magnet 8 is ring-like, it being mounted as a one piece together with the ferromagnetic armature 3 and with the plunger 2, using engineering solutions such as press fit, gluing or other method which is also compatible with presence of brake fluid.
The role of the permanent magnet 8 is to hold the valve in closed position once the valve is closed even after the solenoid coil 6 is de-energized, such as the times when the vehicle is parked for long time duration or the battery has a weak condition or removed all together.
The permanent magnet 8 is characterized by a magnetic field that is chosen depending on a force of the return spring 4, so that the magnetic force generated by the magnetic field of the permanent magnet 8 to be greater than the elastic force of the return spring 4.
The magnetic force of the permanent magnet 8 and the elastic force of the return spring 7 are balanced by the magnetic force resulting from the current applied through the solenoid coil 6, to achieve one of the desired valve states: opened or closed position.
The method of using the bi-stable circuit split valve CSV comprises the following steps: The level sensor sends a warning signal to a processing unit of a brake fluid reservoir when the braking fluid has a warning level SL1. In this case the processing unit sends corresponding instructions to the electrical unit of the brake system to close the bi-stable circuit split valve CSV.
Further on, a first electrical signal is applied by the electrical unit of the brake system to the solenoid coil 6, for driving the plunger 2, together with the ferromagnetic armature 3 from the open position to the closed position of the bi-stable circuit split valve CSV. The first electrical signal has the same polarity as the polarity of the permanent magnet, so as to close the valve.
The permanent magnet 8 maintains the position of the plunger 2, together with the ferromagnetic armature 3, ensuring the closed position of the bi-stable circuit split valve CSV for a predetermined period of time, namely until servicing the leak and bringing the braking fluid from the reservoir at the nominal level SLO.
The processing unit send instructions to the electrical unit of the brake system to open the bi-stable circuit split valve CSV, the electrical unit applying a second electrical signal to the solenoid coil 6, for driving the plunger 2 together with the ferromagnetic armature 3 from said closed position to said open position of the bistable circuit split valve CSV. The second electrical signal has opposite polarity in respect to the polarity of the permanent magnet.
REFERENCE SIGNS
CSV circuit split valve CSV CA central axis M main cylinder SLO nominal level of braking fluid in the reservoir SL1 warning level of braking fluid in the reservoir 1 valve house 1.1 valve house opening portion 2 plunger 3 ferromagnetic armature 4 valve seat valve body 5.1 valve body central cavity 5.2 valve body central through bore 6 solenoid coil 7 return spring 8 permanent magnet 9 valve closing element 9.1 valve closing element central cavity
Claims (6)
- CLAIMS1. Bi-stable circuit split valve CSV for a brake system, the bi-stable circuit split valve CSV valve having a central axis (CA), the bi-stable circuit split valve CSV comprising a brake fluid inlet and a brake fluid outlet for communicating with the brake system for passaging of a fluid under pressure therethrough, the bi-stable circuit split valve CSV further comprising: - a valve house (1) having a valve house opening portion (1.1); - a ferromagnetic armature (3) based within said valve house (1), said ferromagnetic armature (3) having a central bore; - a valve body (5) mounted on said ferromagnetic armature (3), positioned at the valve house opening portion (1.1), said valve body (5) having: * a valve body central cavity (5.1) extending along the central axis (CA), faced toward the ferromagnetic armature (3), configured to receive a return spring (7); * a valve body central through bore (5.2) extending along the central axis (CA) in line with valve body central cavity (5.1); - a valve closing element (9) joining with said valve body (5), said valve closing element (9) comprising a valve closing element central cavity (9.1) extending along the central axis (CA) faced toward the valve body (5), said valve closing element central cavity (9.1) being configured to receive a valve seat (4) to be centrally placed within the valve closing element central cavity (9.1); - a plunger (2) that is centrally mounted within the central bore of the ferromagnetic armature (3) in axial alignment with a longitudinal axis of said valve seat (4) corresponding to the central axis (CA), said plunger (2) being accommodated within the valve body central through bore (5.2) protruding the valve closing element central cavity (9.1), and said valve closing element central cavity (9.1) to engage with said valve seat (4), * said plunger (2) being axially movable within the valve body (5) along the central axis (CA) between two predetermined positions in respect to said valve seat (4), corresponding to an open position and a closed position of the bi-stable circuit split valve CSV; said open position being defined by a spaced positioning of the plunger (2) in respect to said valve seat (4), creating a fluid passage connecting said brake fluid inlet with said brake fluid outlet of the bi-stable circuit split valve CSV; r said closed position being defined by engagement of the plunger (2) with said valve seat (4); -a solenoid coil (6) mounted around said valve house (1), generating an electromagnetic force corresponding to an electric current applied to said solenoid coil (6) configured for driving said plunger (2) together with the ferromagnetic armature (3) from said open position to said closed position; -said return spring (7) being mounted around said plunger (2) on the ferromagnetic armature (3) within the valve body (5), said return spring (7) having an elastic force configured for driving said plunger (2) together with the ferromagnetic armature (3) from said closed position to said open position when no current is applied to said solenoid coil (6), wherein said bi-stable circuit split valve CSV valve further comprises a permanent magnet (8) mounted as one piece together with said plunger (2) and with the ferromagnetic armature (3), said permanent magnet (8) having a magnetic force, wherein the magnetic force of said permanent magnet (8) is greater than the elastic force of the return spring (7), such that to maintain-said plunger (2) together with the ferromagnetic armature (3) on said closed position when no current is applied to said solenoid coil (6).
- 2. Bi-stable circuit split valve CSV valve according to claim 1, wherein the permanent magnet (8) is mounted by press fit together with said plunger (2) and with the ferromagnetic armature (3),
- 3. Bi-stable circuit split valve CSV valve according to claim 1, wherein the permanent magnet (8) is mounted by gluing together with said plunger (2) and with the ferromagnetic armature (3),
- 4. Bi-stable circuit split valve CSV valve according to any preceding claim wherein the material of the magnet (8) is one of the following: neodymium, samarium cobalt, ferrite, alnico or flexible rubber.
- 5. Brake system of a vehicle with a pair of front wheels and a pair of rear wheels characterized in that it comprises the bi-stable circuit split valve CSV valve according to any of the preceding claims.
- 6. Method of use of the bi-stable circuit split valve CSV valve according to any of the claims 1-4 wherein the pressurized brake fluid inlet is communicating with a brake fluid reservoir line and said pressurized brake fluid outlet is communicating with a brake fluid wheels line, characterized in that the method comprises the following steps: -receiving a warning signal from by a processing unit of a brake fluid reservoir when at least one sensor of the brake system, including the brake fluid level sensor (SL), detect a specific level of braking fluid (SL1); - sending corresponding instructions by the processing unit to the electrical unit of the brake system to close the bi-stable circuit split valve CSV; -applying a first electrical signal by the electrical unit of the brake system to said solenoid coil (6) for driving said plunger (2) together with the ferromagnetic armature (3) from said open position to said closed position of the bi-stable circuit split valve CSV; said first electrical signal having the same polarity as the polarity of the permanent magnet; -maintaining said plunger (2) by the permanent magnet (8) together with the ferromagnetic armature (3) on said closed position of the bi-stable circuit split valve CSV for a predetermined period of time; - sending corresponding instructions by the processing unit to the electrical unit of the brake system to open the bi-stable circuit split valve CSV when at least one sensor of the brake system, including the brake fluid level sensor (SL), detect a specific level of braking fluid (SLO); - applying a second electrical signal by the electrical unit of the brake system to said solenoid coil (6) for driving said plunger (2) together with the ferromagnetic armature (3) from said closed position to said open position of the bi-stable circuit split valve CSV; said second electrical signal having opposite polarity in respect to the polarity of the permanent magnet.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP22465548 | 2022-08-08 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB202211570D0 GB202211570D0 (en) | 2022-09-21 |
| GB2623479A true GB2623479A (en) | 2024-04-24 |
Family
ID=83149316
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2211570.3A Pending GB2623479A (en) | 2022-08-08 | 2022-08-09 | Bi-stable circuit split valve CSV, brake system including bi-stable circuit split valve CSV, and method of using thereof |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2623479A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3910642A (en) * | 1973-09-28 | 1975-10-07 | Toyota Motor Co Ltd | Brake for automobiles provided with electromagnetic cut-off valves |
| SU1068312A1 (en) * | 1981-12-25 | 1984-01-23 | Triger Boris G | Safety device for hydraulic brake actuators |
| US6164734A (en) * | 1997-03-14 | 2000-12-26 | Toyota Jidosha Kabushiki Kaisha | Vehicle hydraulic braking system having reservoir for storing fluid discharged from brake cylinder through pressure control valve device |
| US20200055509A1 (en) * | 2017-05-29 | 2020-02-20 | Robert Bosch Gmbh | Bistable Solenoid Valve for a Hydraulic Braking System and Corresponding Hydraulic Braking System |
-
2022
- 2022-08-09 GB GB2211570.3A patent/GB2623479A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3910642A (en) * | 1973-09-28 | 1975-10-07 | Toyota Motor Co Ltd | Brake for automobiles provided with electromagnetic cut-off valves |
| SU1068312A1 (en) * | 1981-12-25 | 1984-01-23 | Triger Boris G | Safety device for hydraulic brake actuators |
| US6164734A (en) * | 1997-03-14 | 2000-12-26 | Toyota Jidosha Kabushiki Kaisha | Vehicle hydraulic braking system having reservoir for storing fluid discharged from brake cylinder through pressure control valve device |
| US20200055509A1 (en) * | 2017-05-29 | 2020-02-20 | Robert Bosch Gmbh | Bistable Solenoid Valve for a Hydraulic Braking System and Corresponding Hydraulic Braking System |
Also Published As
| Publication number | Publication date |
|---|---|
| GB202211570D0 (en) | 2022-09-21 |
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