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WO1989001431A1 - Systeme de freinage a dispositif anti-blocage/commande de traction pourvu de soupapes d'isolation actionnees par la pression - Google Patents

Systeme de freinage a dispositif anti-blocage/commande de traction pourvu de soupapes d'isolation actionnees par la pression Download PDF

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Publication number
WO1989001431A1
WO1989001431A1 PCT/US1988/002634 US8802634W WO8901431A1 WO 1989001431 A1 WO1989001431 A1 WO 1989001431A1 US 8802634 W US8802634 W US 8802634W WO 8901431 A1 WO8901431 A1 WO 8901431A1
Authority
WO
WIPO (PCT)
Prior art keywords
valve
communicated
port
brake
pressure
Prior art date
Application number
PCT/US1988/002634
Other languages
English (en)
Inventor
Jack Ralph Phipps
Original Assignee
Allied-Signal Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Allied-Signal Inc. filed Critical Allied-Signal Inc.
Priority to KR1019890700675A priority Critical patent/KR890701398A/ko
Publication of WO1989001431A1 publication Critical patent/WO1989001431A1/fr

Links

Classifications

    • 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
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • 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
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/36—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition including a pilot valve responding to an electromagnetic force
    • 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
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/44—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition co-operating with a power-assist booster means associated with a master cylinder for controlling the release and reapplication of brake pressure through an interaction with the power assist device, i.e. open 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
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/48—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition connecting the brake actuator to an alternative or additional source of fluid pressure, e.g. traction control systems
    • B60T8/4809—Traction control, stability control, using both the wheel brakes and other automatic braking systems
    • B60T8/4827—Traction control, stability control, using both the wheel brakes and other automatic braking systems in hydraulic brake systems

Definitions

  • the present invention is generally related to automotive braking systems and more particularly to 5 anti-lock/traction control braking systems having pressure operated isolation valves.
  • Another purpose of the present invention is to provide an anti-lock/traction braking system which uses pressure activated isolation valves.
  • a further purpose of the present invention is to provide means for automatically preventing the Q operation of the isolation valve(s) if adequate pressure is not available for reapplication of brake force (after release) during- anti-lock system operation.
  • An additional purpose of the present invention is to utilize many of components of an 5 anti-lock system to control tractive effort.
  • an anti-lock braking system comprising: first means, for increasing brake fluid pressure in response to operator demand, means for storing excessive brake fluid; means responsive to signals indicative of the rotational state of each wheel; pump means for providing additional pressurized brake fluid, in response to at least one of the wheel motion signals.
  • the system also includes means, including first and second brake channels for braking the motion of predetermined sets of wheels.
  • the system includes first and second regulators responsive to the pressure levels established by the first means for regulating the fluid pressure at respective output ports to approximately the pressure level established by the first means; valve means including a first solenoid responsive to a control signal, having a first condition for communicating the output of the first regulator to a pressure responsive first isolation valve, and a second condition for communicating the first isolation valve to a reservoir or storage means; and second solenoid means responsive to control signals having a first condition for communicating the output of the second regulator to a pressure 0 responsive second isolation valve and having a second condition for communicating the second isolation valve to the storage means.
  • the first isolation valve comprises means 5 responsive to pressure levels established by the pump means for respectively and selectively permitting fluid flow between a) the first means and the first brake channel or b) between first valve means and the first braking channel.
  • the second isolation valve Q also comprises means responsive to pressure levels as established by the pump means for respectively and selectively permitting fluid flow between a) the first means and the second brake channel, or b) second valve means and second braking channel.
  • the system further includes a traction control subsystem including pressure responsive shuttle valve means, situated upstream of the non-driven wheels comprising: traction valve means having a first operational state for communicating the pump means to the shuttle valve means and a second operational state for communicating the shuttle valve means to the reservoir in response to a control signal.
  • the shuttle valve means includes means, movable to a first position for respectively communicating the first or second solenoids to corresponding non-driven wheel brake cylinders in response to the fluid pressure of the pump, and movable to a second position for prohibiting the build up of brake pressure in the non-driven wheel brakes.
  • FIGURE 1 schematically represents a two channel three solenoid anti-skid system which optionally includes traction control. -5-
  • FIGURE 2 shows an alternate two channel system.
  • FIGURE 3 shows a detailed view of one of the isolation valve of FIGURE 1.
  • FIGURE 4 is a cross-sectional view taken through section 4-4 of FIGURE 3.
  • FIGURE 5 shows an alternate emboderment of a 0 spring used in the isolation valves.
  • FIGURE 1 illustrates a two-channel, three ,. solenoid anti-skid/traction control braking system 16 for controlling the motion of the various wheels 18 of a vehicle.
  • the system 16 comprises first means for increasing the brake fluid pressure in response to operator demand.
  • Such first means may include a 0master cylinder 22 having respective pressure chambers 24 and 26 each of which are communicated to a fluid reservoir 28.
  • a drive link 30 is attached to the brake pedal (not shown) in a known manner.
  • the master cylinder 22 may be ⁇ activated by a power assist mechanism such as a vaccuum power booster which is schematically shown as 32.
  • the system 16 further includes an electronic 0 control unit (ECU), generally designated as 40, responsive to signals ( s ⁇ s n ) indicative of the rotational state of each wheel 18.
  • ECU electronic 0 control unit
  • a pump 50 is used 1431 '
  • the pump is driven by an electric motor 56 in response to a control signal generated by the ECU 540
  • the system further includes brake means, responsive to fluid pressure for slowing the rotation of selective wheels 18.
  • the system 0 includes a plurality of brake cylinders 62a-d one each associated with each wheel 18a-d. As it is known in the art these brake cylinders form part of typical disc brakes or foundation brakes. Associated with each of the wheels is a wheel speed sensor and tone 5wheel for generating a series of pulses indicative of the rotational speed of particular wheel. Such wheel speed senors and tone wheels are not illustrated in FIGURE 1 since such devices are standard in the art of adaptive or anti-lock braking systems.
  • the braking means is divided into two substantially identical braking channels 64a and b. As illustrated in FIGURE 1 the braking channel 64a and b are split braking channels. As an example, braking channel 64a may comprise one
  • the braking channel 64b includes the remaining brake cylinders 62b and d. It should be appreciated that each braking channel includes the corresponding tone wheels and 3Q sensors for each of the respective wheels. Obviously, other splits between the brake cylinders can be used such as a front-to-rear split.
  • the output 52 of the pump 50 is communicated to separate regulator means 70a and 70b, one for each brake channel 64a and 64b. As illustrated, such regulators 70a and b are of the differential pressure 5 regulator type responsive to the pressure level established by the pump 50 as well as to the pressure level established by the respective chambers 24 and 26 of the master cylinder 22. The purpose of the differential pressure regulators is to maintain the 2 Q pressure at their respective outputs 72a and 72b at approximately the pressure level within the chambers of the master cylinder as established by the operator. The system can also be configured with a single regulator.
  • a first valve such as solenoid valve 80a, responsive to a control signal generated by the ECU
  • solenoid valve 80a includes a first port 82a, second port 84a and a third port 86a. In the absence of a control signal received from the ECU 40 the first and second ports 82a and 84a respectively, are communicated to each other through a control orifice
  • the second port 84a is communicated to a first port 92a (part of an alternate flow path) of a first pressure responsive isolation valve 90a.
  • the third port 86a of the solenoid valve 80a is communicated to the reservoir 28.
  • the isolation valve 90a is a pressure responsive valve and more particularly, is responsive to the pressure level established by the pump 50 which is received at port 98a.
  • 5 valve further includes ports 94a and 96a.
  • Port 94a is communicated to one of the chambers, such as chamber 24 in the master cylinder 22 and port 96a is communicated through a brake line 100a to the brake cylinders within the first braking channel 64a.
  • the 0 isolation valve 90a further includes a bias spring 101a for biasing the isolation valve 90a against the fluid pressure established by the pump 50. When the fluid pressure of the pump 50 is below a first pressure level the isolation valve will be in a 5 condition as shown in FIGURE 1 wherein the master cylinder chamber 24 is communicated directly to the brake cylinders in the first braking channel 64a through ports 94a and 96a respectively. As described below, the pressure generated by the pump 50 will
  • isolation valve 90a increases as the motor 56 turns in response to a 20 control signal generated by the ECU 40.
  • the isolation valve is moved such that the ports 92a and 96a are placed in direct communication thereby isolating the master cylinder chamber 24 from the remainder of the • braking system and permitting fluid at the output 72a of pressure regulator 70a to be communicated through the solenoid valve 80a to the braking channel 64a.
  • the isolation valve 90a is shown in greater detail in FIGURE 3.
  • the system further includes a second valve, such as solenoid valve 80b, responsive to control signals generated from the ECU 40, an isolation valve 90b communicated with the pump in a like manner as previously described for isolation valve 90a and regulator 70b.
  • a second valve such as solenoid valve 80b
  • the pump 50, solenoid valve 80b, isolation valve 90b and pressure regulator 70b are connected to and through the second braking channel 64b in a manner identical with that described above with the exception that the isolation valve 90b is connected to the second chamber 26 of the master cylinder 22.
  • Each brake channel 64a and 64b typically includes a proportioning valve 110a and 110b respectively, for the rear vehicle wheels 18c and d.
  • the proportioning valves are communicated to the brake lines 100a and 100b through a shuttle valve 112.
  • the shuttle valve is a pressure responsive valve having two modes of operation. The first mode of operation, permits direct communication of the proportioning valves 110 to the brake lines 100. The second mode of operation is entered into in response to an increased pump pressure and terminates communication between the proportioning valves and the brake lines. Pressure is communicated to the shuttle valve 112 from the pump 50 through a third valve such as an electrically responsive third solenoid valve 120.
  • the solenoid valve 120 includes ports 122, 124 and 126. The port
  • 128 is primarily to permit the incorporation of a 1 r ' '
  • FIGURE 1 illustrates the condition of the system during normal braking operations with the traction control portion of the system deactivated.
  • brake pressure from the master cylinder 22 is communicated through the isolation valves 90a and 90b . to the appropriate braking channels 64a and 64b.
  • the performance of the system is characterized by normal braking.
  • the ECU 40 monitors the output of the wheel speed sensors (not shown) corresponding to each of the wheels 18 of the vehicle.
  • a brake switch signal (m) indicative that the brake pedal has been applied by the operator, the ECU determines whether or not one or more of the wheels of the vehicle are skidding or are approaching an impending wheel skid situation.
  • skidding and impending skid are used synonomously.
  • the ECU 40 Upon the application of the brakes the ECU 40 generates a signal indicative of average deceleration of the various wheels.
  • the ECU When the average deceleration increases to a predetermined value, such value being indicative of impending or actual skid the ECU generates control functions to thereby decay and/or build the pressure within the brake cylinder for the skidding wheel. If such condition occurs the ECU additionally provides a signal to activate pump 50. Very quickly after start up of the pump the pressure at the pump outlet 52 will raise to a sufficiently 5high level to overcome the spring bias on the isolation valves 90a and 90b. For the present example it is assumed that one of the wheels in the channel 64a has been detected as skidding.
  • the isolation valves change their state in response to the supplied 0 pressure from the pump 50 such that ports 96a and 96b are communicated to ports 92a and 92b respectively.
  • this change in the .operational state of the isolation valves 90a and 90b isolates the master cylinder from the remaining portion of the system and 5 maintains the pressure within the master cylinder 22 to a value sufficiently high that the operator of the vehicle senses that full brake pressure is still being supplied to brake cylinders 62a-d.
  • the non-skidding wheels of braking channel 64b it is 0desired that normal braking continue for these wheels. This is accomplished by controlling the brake cylinders 62b and 62d through the brake pressure developed at the output of pressure regulator 70b.
  • the pressure regulator 70b is a 5differential pressure regulator and consequently its output pressure, at port 72b, will be substantially equal to the value of fluid pressure within the master cylinder chamber 26. Such pressure is communicated to braking channel 64b through orifice 88b within ⁇ S ⁇ lenoid valve 80b via the isolation valve 90b. 31
  • the ECU generates a control (decay) signal to the first solenoid valve 80a causing same to change its state thereby communicating the first isolation valve 90a to the reservoir via ports 84a and 86a. It should be apparent from the above that by communicating the various brake cylinders, within braking channel 64a to the reservoir 28, through the isolation valve 90a and solenoid valve 80a the brake pressure within the brake cylinders 62a and 62c is permitted to decrease.
  • the ECU 40 continually monitors the rotational state of the wheels and when it senses that the acceleration of the locked or skidding wheel is zero or positive (indicating that the wheel has begun or is just about to rotate) the ECU 40 removes the control signal (which causes solenoid valve 80a to change state) thereby reestablishing communication between ports 82a and 84a.
  • the fluid pressure established at the output of the differential pressure regulator 72a is communicated to the brake cylinders within braking channel 64a through the isolation valve 90a and through the orifice 88a within the solenoid valve 80a.
  • the orifice 88a reduces the rate of the pressure rise to the skidding wheel(s) to avoid immediate and premature wheel lock-up.
  • the ECU 40 monitors the rotational state of the wheels to determine if the re-applied pressure has again caused the wheel to reenter the locked condition whereupon -13-
  • control signal to solenoid valve 80a is applied thereby dumping or relieving the brake pressure to the reservoir, permitting the locked -'' eel to again reaccelerate. Thereafter, the control signal is again 5 removed and pressure is supplied to the brake cylinders through the orifice 88a. The above conditions are continued until the wheel skid condition has terminated and the ECU 40 removes the control signal to the pump 50 which causes both of 10 the isolation valves 90 to assume their normal non-anti-lock position and reestablishes normal brake control between the master cylinder and the various wheel cylinders.
  • the traction control portion is operated independently of the anti-skid portion of the system.
  • the purpose of traction control is to 0 maintain the difference in the rotational velocities of the driven wheels at a predetermined level.
  • the operation of the traction control system is best understood by the following example where it is assumed that the vehicle is at rest having one of the
  • the driven wheels are supplied torque through a differential.
  • the differential always -14-
  • the torque transmitted to the slower wheel is limited to the torque transmitted to the wheel on the lowest 5coefficient surface.
  • the traction control system is activated when the brakes are not manually applied.
  • a signal indicative of the condition of the brakes may be obtained in a normal manner from a brake switch of a known variety. During such no-brake 5 condition the ECU compares the rotational velocity of the driven wheels.
  • the ECU 40 will compare the rotational velocities of each of the front wheels. Upon determining that a difference in velocity exists which Q exceeds a predetermined minimum, the ECU generates a control signal to the pump 50. The increased pressure from the pump 50 is communicated to the isolation valves 90a and 90b causing them to change state. The pump is also communicated to a third or traction solenoid valve 120. As can be seen, the output port 126 of solenoid valve 120 is communicated to the shuttle valve 112 as well as to the check valves 128a and 128b.
  • the output port 126 is communicated to the reservoir 28. This communication causes a pressure differential across the check valves 128a, 128b thereby isolating the traction control system from the anti-skid portion of the system.
  • the lenoid valve 120 is caused to change state thereby
  • the shuttle valve 112 has two states. The first operational
  • FIGURE 1 10 state, illustrated in FIGURE 1, is active during the anti-skid mode of operation wherein brake fluid is permitted to flow through the proportioning valves 110 to the various wheel cylinders.
  • the second mode of operation that is, the mode active during traction
  • brake fluid communication is terminated to the non-driven wheels which, upon reflection, is desirable since the purpose of the traction control system is to enable the vehicle to move forward and as such, if undesired brake application occurs the
  • solenoid valve 80a and 80b 2588a and 88b in solenoid valves 80a and 80b.
  • solenoid valve 80a or 80b as the case may be, will also be actuated to prevent brake application.
  • the ECU 40 causes the solenoid valve, such as solenoid valve 80a corresponding to the lower rotating non-spinning driven wheel to change state thereby communicating its port 84a to the reservoir through port 86a.
  • This action effectively prohibits braking fluid from being communicated to this low velocity wheel.
  • FIGURE 2 illustrates an alternate two channel, anti-skid/traction control system.
  • the brake pressure of the skidding wheel has been lowered to a level wherein the gwheel deceleration has been reduced to zero or alternatively the acceleration increases (which is indicative of the fact that the wheel has begun to -17-
  • the ECU 40 causes solenoids 80 to reapply the brake pressure through the various orifices 88.
  • the anti-skid/traction control system of FIGURE 2 has many of the components illustrated in FIGURE 1. It should be noted that like components are shown with the same numeral used in FIGURE 1.
  • the solenoid valves 80a and 80b are each replaced by two sets of solenoid valves, 150a and 152a and 150b and 152b.
  • One of the purposes of the solenoid valves 150a and 150b is to permit the reapplication of brake pressure to the skidding wheel's brake cylinder and as such they are also referred to as build valves or build solenoids.
  • One of the functions of the solenoids 152a and 152b is to permit pressure in the various wheel cylinders to decay and similarly these solenoids 152 are also referred to as decay valves or decay solenoids.
  • each of the solenoid valves 150 and 152 is shown schematically and includes two operational modes, a closed mode and an open mode which respectively permits or prohibits fluid flow 431 '
  • the initial functional operation system of FIGURE 2 is substantially identical to the initial operation of the system described in FIGURE 1, that is, upon the application of the brakes the ECU 40 generates a deceleration signal indicative of the rotational state of the various wheels. When such deceleration increases to a predetermined value, such value being indicative of impending or actual skid the ECU generates a plurality of control functions to thereby decay, hold and build the pressure within the brake cylinder for the skidding wheel. As an example, it is again assumed that one of the wheels in the braking Channel 64a is skidding or at an impending skid situation.
  • the pump 50 is activated as described above thereby causing the isolation valves 90a and 90b to change tneir respective operational states.
  • the ECU 40 o9enerates a signal to the decay valve 152a, which was previously closed (no flow), causing it to change state thereby providing a flow path from the skidding wheel's brake cylinder to the reservoir 28, in order to reduce the brake pressure in the wheel brake 5cylinder.
  • the ECU thereafter monitors the rotational state of the previously skidding wheel to determine when that wheel's acceleration is zero or positive. At this point in time the control signal is removed and the decay- valve 152a closed (no flow) to prohibit Q a further decrease in brake pressure.
  • the ECU Upon closing (no flow) the decay valve 152a and with the build valve 150a also in a closed (no flow) condition, fluid pressure within the skidding wheel's brake cylinder cannot increase or decrease and is maintained or held at the level of brake pressure sufficient to permit the wheel to reaccelerate.
  • the ECU After the previously 5 skidding wheel has accelerated sufficiently, the ECU generates another control signal to the build valve 150a thereby opening (flow) same to communicate the output of the differential pressure regulator 70a to the skidding wheel's brake cylinder through the 0 isolation valve 90a thereby increasing the brake pressure to controllably slow the rotational speed of the wheel. The rate of change of.
  • this reapplied brake pressure is controlled through an orifice 154a formed within the build valve 150a as well as by duty-cycle .modulation of the valve.
  • the build valve 150a may be maintained opened (flow) or alternatively may be pulsed between open and closed conditions to permit the brake pressure to gradually increase. If the 0 reapplied brake pressure communicated through the build valve 150a is sufficient to cause the previously skidding wheel to again enter into a skid condition the ECU terminates the control signal to the build valve thereby prohibiting additional buildup of 5pressure, and essentially simultaneously reactivates the decay valve thereby . decreasing the brake line pressure.
  • FIGURE 2 The above functions of decay, hold and build of the brake pressure are continued until the previously skidding wheel has been brought under n control.
  • the operation of the traction control portion of FIGURE 2 is similar to that of FIGURE 1.
  • the pump pressure is communicated through the solenoid valve 120 and to the check valves 128.
  • the build and decay valves 150b and 152b of the slower rotating wheel remain non-activated to prevent brake pressure build-up. To slow the motion of the higher
  • the build valve 150a is activated by the ECU 40 thereby communicating the pump 50 to its brake cylinder 62a through the isolation valve 90a slowing same. Further the level of pressure can be controlled by also activating the 0 decay valve 152a.
  • FIGURE 3 illustrates a detailed cross-section of one of the isolation valves.
  • the isolation valves 90a and b are identical.
  • the isolation valve 90a includes 5 a housing 200 having a stepped bores 202a and 202b therethrough. Situated proximate the middle of the valve is the port 96a which is adapted to communicate with certain of brake cylinders 62.
  • the port 96a terminates within the housing at annular passage 204.
  • Situated within the passage is a ball 206 supported within a ball cage 208.
  • the ball 206 is axially movable to selectively close a first 220a and a second passage 220b.
  • the first and second passages are formed within opposingly spaced valve seats 224a and
  • Each valve seat is received within an insert 228a and 228b.
  • Each insert is substantially identical and includes a necked-down portion 232a, 232b which form 3Q in cooperation with the housing 200 fluid annuli 234a and 234b.
  • a port such as port 94a communicates the annulus 234a with a chamber of the master cylinder 22.
  • Another port such as port 92a communicates the annulus 234b with a solenoid valve such as valves 80, 150 or 152.
  • the inserts 228a and b include first bores 240a, 240b respectively, which receive at one end thereof the valve seats 224a or 224b.
  • the other 5 end of each insert includes a cross-hole 242a or 242b to communicate the first bores 240a,240b with its respective annuli 234a or 234b.
  • each first bore 240 Oppositely positioned from each first bore 240 is a second bore 250a,250b. Each first and second bore is separated by a member l ⁇ 252a,252b which radially extends inwardly and terminates at an opening 254a,254b.
  • a pressure equalization passage 256a,256b connects each second bore 250a, 250b with its corresponding annulus 234a,234b.
  • Extending through each insert is a rod 260a or 260b which extends through the passage 220a or 220b to selectively bias the ball 206 against the passages 200a or 220b closing same.
  • the rod 260a is radially stabilized by an O-ring retainer 262 having an opening 264.
  • the retainer 262 also functions as a
  • the rod guide 268 Received within the second bore 250b of the insert 228b is a rod guide 268.
  • the rod guide 268 includes a narrow opening 270 through which the rod 260b extends.
  • the rod guide 268 terminates at a flanged end 272 having cross-slots 274
  • rod 260a,260b is an O-ring 276a, 276b and back-up ring 278a, 278b.
  • rod guide 268 its flanged end terminates short of the wa.ls of the stepped bore 202b.
  • a piston housing 280 Received within the stepped bore 202b is a piston housing 280. The piston housing 280 terminates
  • the piston housing 280 includes a bore 285 for receipt of
  • the piston 286 may be formed integral with or separate from the rod 260b.
  • the piston 286 includes a partial bore 288 for. receipt of a spring 290 which biases the piston 286, and rod 260b against the ball 206 thereby urging same in the direction of l5 ⁇ assage 220a.
  • the spring 290, piston 286, piston housing 280 are secured within the housing 200 by spring retainer or end cap 292 and the threaded retainer 294.
  • the port 92a communicated to the various solenoid valves. Also formed within the housing 200 is the supply port 98a which is connected
  • the partial bore 288 of the piston 286 is communicated to the supply port via cross-holes 302 and a groove 304 formed in the piston
  • An end 310 of the rod 260a extends out from the insert 228a and is received within a rod cap 312.
  • the rod cap 312 includes a radial flange 314 for receipt of spring 316.
  • Another end cap 320 secures the rod cap 312, spring 316, rod 260a, etc., in place and may also include an air vent 321.
  • the spring 316 urges the ball 206 to the right as viewed in FIGURE 3, to close off passage 220b.
  • the end 310 of the rod 360a is received within an oversized bore 322 which eliminates misalignment lO Proble s between the rod cap 312 and rod 260a.
  • a ball 323 is located in the bore 322 and functions as a seat for the rod 260a.
  • the spring 316 urges the ball 206 off from the passage 220a, thereby providing a flow path from the master cylinder to the brake cylinders through ports 94a and 96a.
  • pump pressure is supplied to the
  • FIGURE 5 illustrates an alternate embodiment of the invention. More specifically, there is illustrated a spring 316a suitable to replace spring 316.
  • Spring 316 as shown in FIGURE 3 may be a linear spring. As such, upon the application of pump pressure to the isolation valve the ball 206 will be moved in a relatively linear manner from passage 220b to passage 220a to isolate the master cylinder as described above.
  • Spring 316a s a snap spring comprising upper and lower members 350 and 352 of a general cylindrical shape. Extending between the upper and lower members about the circumference thereof are a plurality of spaced ribs or fingers 354 which may be formed integrally with .members 350 and 352.
  • the lower member 352 is received about the rod cap 312 and urges same toward the ball 206.
  • the snap spring 316a prohibits the linear movement of the ball toward passage 220a.
  • the snap spring 316a continually urges the ball Q against passage 220b until the fluid pressure applied to the piston 286 reaches a specified level. At such time the fingers 354 rapidly deform, snap or buckles outwardly permitting the spring 316a to compress. This action permits the ball 206 to transition from 5?assage 220b to passage 220a almost instantaneously.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Electromagnetism (AREA)
  • Regulating Braking Force (AREA)

Abstract

Système de commande adaptatif de freinage/traction (10) comprenant un certain nombre de soupapes à solénoïde (80, 150, 152) qui règlent la pression appliquée à un certain nombre de cylindres de freins (62). Le système peut fonctionner en mode anti-blocage pour commander le mouvement des roues en dérapage et également dans un autre mode pour réguler la force de traction appliquée aux roues. Des soupapes d'isolation (90) actionnées par la pression sont positionnées entre un maître-cylindre (22), les solénoïdes et les différents cylindres de freins pour réguler le passage de fluide entre ces éléments. Les soupapes d'isolation sont actionnées par une pompe à commande électrique.
PCT/US1988/002634 1987-08-21 1988-08-02 Systeme de freinage a dispositif anti-blocage/commande de traction pourvu de soupapes d'isolation actionnees par la pression WO1989001431A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1019890700675A KR890701398A (ko) 1987-08-21 1988-08-02 압력작동식 분리밸브들을 구비한 안티-로크/견인제어 브레이크 작동시스템

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US8863187A 1987-08-21 1987-08-21
US088,631 1987-08-21

Publications (1)

Publication Number Publication Date
WO1989001431A1 true WO1989001431A1 (fr) 1989-02-23

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Application Number Title Priority Date Filing Date
PCT/US1988/002634 WO1989001431A1 (fr) 1987-08-21 1988-08-02 Systeme de freinage a dispositif anti-blocage/commande de traction pourvu de soupapes d'isolation actionnees par la pression

Country Status (2)

Country Link
KR (1) KR890701398A (fr)
WO (1) WO1989001431A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992003320A1 (fr) * 1990-08-17 1992-03-05 Allied-Signal Inc. Soupape d'injection de pression pour un systeme de freinage adaptatif et de commande de traction
WO1992003321A2 (fr) * 1990-08-17 1992-03-05 Allied-Signal Inc. Systeme de commande d'avancement et de freinage adaptif a pression lineaire variable
WO1992003318A1 (fr) * 1990-08-17 1992-03-05 Allied-Signal Inc. Maitre-cylindre avec regulateur d'alimentation integre
FR2843926A1 (fr) * 2002-09-02 2004-03-05 Poclain Hydraulics Ind Dispositif anti-patinage et anti-blocage des roues d'un vehicule utilisant le circuit de freinage

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4316642A (en) * 1979-03-05 1982-02-23 Itt Industries, Inc. Control device for hydraulic brake systems incorporating antiskid control apparatus
US4462642A (en) * 1981-06-24 1984-07-31 Robert Bosch Gmbh Vehicle brake system
EP0156323A2 (fr) * 1984-03-23 1985-10-02 Nippondenso Co., Ltd. Dispositif de commande de pression hydraulique à l'usage dans des systèmes de freinage antidérapants
DE3505410A1 (de) * 1985-02-16 1986-08-21 Alfred Teves Gmbh, 6000 Frankfurt Hydraulische bremsanlage
US4687260A (en) * 1984-11-01 1987-08-18 Nippondenso Co., Ltd. Antiskid control device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4316642A (en) * 1979-03-05 1982-02-23 Itt Industries, Inc. Control device for hydraulic brake systems incorporating antiskid control apparatus
US4462642A (en) * 1981-06-24 1984-07-31 Robert Bosch Gmbh Vehicle brake system
EP0156323A2 (fr) * 1984-03-23 1985-10-02 Nippondenso Co., Ltd. Dispositif de commande de pression hydraulique à l'usage dans des systèmes de freinage antidérapants
US4687260A (en) * 1984-11-01 1987-08-18 Nippondenso Co., Ltd. Antiskid control device
DE3505410A1 (de) * 1985-02-16 1986-08-21 Alfred Teves Gmbh, 6000 Frankfurt Hydraulische bremsanlage

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992003320A1 (fr) * 1990-08-17 1992-03-05 Allied-Signal Inc. Soupape d'injection de pression pour un systeme de freinage adaptatif et de commande de traction
WO1992003321A2 (fr) * 1990-08-17 1992-03-05 Allied-Signal Inc. Systeme de commande d'avancement et de freinage adaptif a pression lineaire variable
WO1992003318A1 (fr) * 1990-08-17 1992-03-05 Allied-Signal Inc. Maitre-cylindre avec regulateur d'alimentation integre
WO1992003321A3 (fr) * 1990-08-17 1992-04-16 Allied Signal Inc Systeme de commande d'avancement et de freinage adaptif a pression lineaire variable
US5110191A (en) * 1990-08-17 1992-05-05 Allied-Signal Inc. Master cylinder with integrated supply regulator
US5172963A (en) * 1990-08-17 1992-12-22 Allied-Signal Inc. Pressure supply valve for an adaptive braking and traction control system
US5188436A (en) * 1990-08-17 1993-02-23 Allied-Signal Inc. Linear variable pressure adaptive braking and traction control system
FR2843926A1 (fr) * 2002-09-02 2004-03-05 Poclain Hydraulics Ind Dispositif anti-patinage et anti-blocage des roues d'un vehicule utilisant le circuit de freinage
WO2004020264A1 (fr) * 2002-09-02 2004-03-11 Poclain Hydraulics Industrie Dispositif anti-patinage et anti-blocage des roues d'un vehicule utilisant le circuit de freinage et une valve de commande
US7244001B2 (en) 2002-09-02 2007-07-17 Poclain Hydraulics Industrie Motor vehicle wheel antiskid and antilock device using the braking circuit

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