WO1997002973A1 - Abs hydraulic brake system - Google Patents

Abs hydraulic brake system Download PDF

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Publication number
WO1997002973A1
WO1997002973A1 PCT/EP1995/002671 EP9502671W WO9702973A1 WO 1997002973 A1 WO1997002973 A1 WO 1997002973A1 EP 9502671 W EP9502671 W EP 9502671W WO 9702973 A1 WO9702973 A1 WO 9702973A1
Authority
WO
WIPO (PCT)
Prior art keywords
line
brake
pressure
master cylinder
valve
Prior art date
Application number
PCT/EP1995/002671
Other languages
German (de)
French (fr)
Inventor
Gerlinde Nattler
Peter Volz
Original Assignee
Itt Automotive Europe Gmbh
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
Priority to DE4423086A priority Critical patent/DE4423086A1/en
Application filed by Itt Automotive Europe Gmbh filed Critical Itt Automotive Europe Gmbh
Priority to DE59505314T priority patent/DE59505314D1/en
Priority to PCT/EP1995/002671 priority patent/WO1997002973A1/en
Priority to EP95925851A priority patent/EP0784554B1/en
Publication of WO1997002973A1 publication Critical patent/WO1997002973A1/en

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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
    • 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
    • B60T8/4863—Traction control, stability control, using both the wheel brakes and other automatic braking systems in hydraulic brake systems closed systems
    • B60T8/4872—Traction control, stability control, using both the wheel brakes and other automatic braking systems in hydraulic brake systems closed systems pump-back 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
    • B60T8/42—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 having expanding chambers for controlling pressure, i.e. closed systems
    • B60T8/4275—Pump-back 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
    • B60T8/42—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 having expanding chambers for controlling pressure, i.e. closed systems
    • B60T8/4275—Pump-back systems
    • B60T8/4291—Pump-back systems having means to reduce or eliminate pedal kick-back
    • 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
    • B60T8/88—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 with failure responsive means, i.e. means for detecting and indicating faulty operation of the speed responsive control means
    • B60T8/92—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 with failure responsive means, i.e. means for detecting and indicating faulty operation of the speed responsive control means automatically taking corrective action
    • B60T8/94—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 with failure responsive means, i.e. means for detecting and indicating faulty operation of the speed responsive control means automatically taking corrective action on a fluid pressure regulator

Definitions

  • the present invention relates to a slip-controlled hydraulic brake system according to the preamble of claim 1.
  • Slip-controlled brake systems that work on the return flow principle form a closed system during an anti-lock control system, e.g. in DE 37 28 480 AI. This means that the amount of brake fluid available for such anti-lock control is limited. So that this limited amount of pressure medium is sufficient for brake slip control, a correspondingly large volume must be conveyed into the brake circuits by the master cylinder when the brake pedal is actuated. If pressure medium is lost in the event of a defect due to a leakage during anti-lock control, this volume cannot be drawn from the storage container in closed systems.
  • the object of the present invention is to provide an anti-lock brake system which works on the return conveyor principle and which works reliably even in the event of a leak during anti-lock control.
  • a brake system according to the preamble of claim 1 is known for example from WO 91/18776.
  • the reserve memory of the known brake system is only used to provide an additional volume for traction control.
  • a switching valve in the pump feed line should therefore only open when the traction control system is active.
  • the volume of the reserve memory should always be made available even when the volume of the master cylinder is exhausted and a further pressure build-up is desired. If, due to a leak, the pressure medium volume available for slip control becomes smaller and the brake pedal is depressed accordingly, the
  • the need to connect the reserve storage is expediently indicated by a displacement sensor which is attached to the brake pedal, to the brake booster or to the master cylinder.
  • An isolation valve is the brake line between the master cylinder and the mouth of the pressure line can be used for various purposes. It can separate the master cylinder from the brake circuit during braking, to which the reserve memory is switched on, so that the pedal feeling for the driver remains unaffected. Such a separating valve can also be used for traction control or for charging the reserve memory - as described in more detail below.
  • the reserve memory can be loaded in that a storage charging power between the master cylinder and the isolating valve branches off from the brake line and the isolating valve remains closed during a pedal operation. Then the master cylinder volume is not conveyed into the brake circuits, but into the reserve storage via the storage charging line.
  • a further possibility for loading the accumulator is that a accumulator charging line branches off from the brake line or from the pressure line of the pump below the isolating valve. In this case, charging cycles are provided in which the isolating valve is closed and the pump brings pressure medium, which it has sucked out of the storage container, into the reserve storage via the pressure line and the storage charging line.
  • a throttle point can be provided between the branching of the accumulator charging line and the confluence of the pressure line in the brake line, which provides a pressure drop between the
  • the isolating valve can also be closed, if available.
  • the reserve storage is to be filled by the pump, there are various ways of connecting the pump to the reservoir.
  • the simplest option would be a direct connection to the storage container. This would result in an open system in which the amount of pressure medium is not limited anyway, so that an auxiliary pressure accumulator is unnecessary.
  • the invention is intended to avoid the disadvantages of open systems. For this reason, it is advisable to open the outlet valve in the return line and the inlet valve in the brake line, for example, so that the pump is connected to the reservoir via the return line and the brake line as well as the master cylinder. This option is suitable for brake systems without a isolation valve. Another possibility is to equip the pump feed line with two switching valves instead of just one, between which a feed line branches.
  • the brake line is connected directly to the reservoir above the isolating valve so that the pump can suck in unhindered.
  • a closed system still remains.
  • a further variant for charging the reserve store consists of laying a store charging line to the suction line, a check valve being inserted into this store charging line, which opens in the direction of filling the store. Then he can Reserve memory can be loaded either by opening the outlet valve in the return line and pressing the pedal, or by stopping a brake slip. Traction control the pressure medium released gets into the reserve memory.
  • Fig. 1 a brake system according to the invention
  • Accumulator charging line branches from the brake line between the master cylinder and the isolation valve.
  • FIG. 2 shows a brake system according to the invention in which the accumulator charging line branches off from the pressure line
  • Fig. 3 shows a brake system according to the invention
  • Storage charging line branches off from the pressure line and which has an additional follow-up line from the master cylinder to the suction side of the pump and
  • FIG. 4 shows a brake system according to the invention, the accumulator charging line of which is connected to the suction line.
  • the second wheel brake per brake circuit provided in a four-wheel vehicle connects to the brake circuit in a known manner, the second brake circuit being constructed analogously to the first brake circuit.
  • 1 is similar in structure to the circuit known from the prior art (WO 91-18776).
  • the master cylinder 1 is connected in a known manner to the reservoir 2, the brake line 3 runs from the master cylinder 1 to the wheel brake 4.
  • the return line 5 leads to the low-pressure accumulator 6.
  • the low-pressure accumulator 6 is connected to the suction side of the pump 8 via the suction line 7 connected, the pressure line 9 opens into the brake line 3.
  • the pump feed line 10 is connected to the suction line 7 and connects the reserve memory 11 to the suction side of the pump 8.
  • An accumulator charging line 12 branches off from the brake line 3 immediately below the master cylinder 1 and leads to the reserve memory 11.
  • the brake line 3 is provided with a isolating valve 13 between the branching of the accumulator charging line 12 and the confluence of the pressure line 9.
  • the isolating valve 13 is an electromagnetically actuated, normally open 2/2-way valve which, when the electromagnet is energized, switches a pressure relief valve into the brake line 3, which opens to the master cylinder 1 at an admission pressure which, for example, is sufficient for traction control in the wheel brake 4.
  • the pressure relief valve can of course also be set up separately in parallel to the isolating valve 13, in which case the isolating valve 13 blocks the brake line 3 in its switching position.
  • a check valve 14 is also connected in parallel with the isolating valve 13.
  • the inlet valve 15 is arranged in the brake line 3.
  • This is a normally open solenoid valve, which is a Check valve is connected in parallel, which opens from the wheel brake 4 to the master cylinder 1.
  • an outlet valve 16 is inserted, a normally closed solenoid valve.
  • the pump feed line 10 can be blocked via a 2/2-way solenoid valve, the switching valve 17, which is also closed when de-energized. So that the reserve memory 11 cannot drain into the storage container 2 when the master cylinder 1 is not actuated, the accumulator charging line 12 has a check valve 18, which opens from the master cylinder 1 to the reserve memory 11.
  • the master cylinder 1 is actuated by the brake pedal 19 to build up pressure in the brake line 3.
  • a distance sensor 20 detects the pedal travel.
  • This displacement sensor 20 can, for example, be coupled to the working piston of a vacuum amplifier as shown.
  • the connection of the master cylinder 1 to the reservoir 2 is disconnected and pressure medium is brought out of the working chambers of the master cylinder 1 into the associated brake circuits.
  • a brake pressure is built up in the wheel brake 4 via the brake line 3.
  • the displacement sensor '20 signals due to the advanced position of the brake pedal 19 that an additional volume of pressure medium is required.
  • the isolating valve 13 is closed, and the switching valve 17 is opened, so that the volume of the reserve memory 11 reaches the suction side of the pump 8, which also starts to run when the valves 13 and 17 are switched.
  • the pump 8 conveys the reserve volume into the brake line 3 from which it gets into the wheel brake 4. Since the pump pressure is generally higher than the required brake pressure, a further brake pressure control takes place through the circuit of the inlet valve 15 and the outlet valve 16, which is known per se.
  • the brake system then works like a known anti-lock brake system according to the return flow principle.
  • the reserve memory 11 can again provide pressure medium when braking later, it must be reloaded in the meantime. In all likelihood, after a full stop, there will be several light stops before the reserve volume is needed again. In the case of such lighter brake applications in which the master cylinder volume is not exhausted, a partial amount of the pressure medium displaced from the master cylinder 1 reaches the reserve memory 11 via the check valve 18, from which it cannot escape as long as the switching valve 17 is closed.
  • an optical signal can also be provided, which recommends that the vehicle driver actuates the brake pedal.
  • the isolation valve may possibly be closed manually.
  • the reserve memory 11 can of course also be used in this brake system for the purposes known from the prior art for traction control. If the pump 8 is designed as a self-priming pump, it can additionally draw in further pressure medium volume beyond that of the reserve reservoir, since the isolating valve 13 is in its switching position during traction control and the master cylinder 1 has a free connection to the reservoir 2.
  • the storage charging line 12 then serves as an intake line for traction control.
  • the brake system according to FIG. 2 differs from that according to FIG. 1 essentially in how the reserve memory 11 is loaded.
  • the accumulator charging line 21 branches off from the pressure line 9 and leads to the reserve switch 11 via the switching valve 22 designed as a 4/2-way valve. The filling of the reserve accumulator 11
  • the outlet valve 16 is switched to its open position, so that the pump 8 through the suction line 7, via the outlet valve 16 and the inlet valve 15 through the brake line 3 and the master cylinder 1 from the Storage container 2 can suck in pressure medium and convey it into the reserve memory 11.
  • the switching valve 22, which blocks either the pump feed line 10 or the accumulator charging line 21, is in its basic position, which blocks the pump feed line 10.
  • the pump 8 cannot pump in a circle when filling the reserve memory 11 and thereby empty the reserve memory 11 again.
  • the accumulator charging line 21 branches off from the pressure line 9 between the pressure side of the pump and a throttle point 23, which generates the required dynamic pressure so that the pressure medium volume delivered by the pump does not immediately return to the main part cylinder 1 flows off.
  • the maximum filling pressure of the reserve reservoir 11 is therefore determined by the delivery pressure of the pump 8, the back pressure of the throttle point 23 and the admission pressure of the check valve 18.
  • the switching valve 22 switches over, so that the reserve memory 11 is now connected to the suction side of the pump 8 via the pump feed line 10.
  • the connection of the pressure line 9 to the reserve memory 11 is interrupted at the same time.
  • the pump 8 therefore only conveys the volume of the reserve storage 11 into the brake line 3.
  • the further functioning of the brake system results from the previous description of FIG. 1 and from the prior art.
  • Fig. 3 a brake system is shown, the reserve memory 11 is filled by the pump 8 as in Fig. 2.
  • the pressure medium path, via which the pump 8 sucks the pressure medium from the storage container 2, is different here.
  • the pump feed line 10 has a further switching valve 24 between the switching valve 22, which is already used in FIG.
  • the switching valve 24 is an electromagnetically operated 2/2-way valve which is closed in its de-energized position.
  • a feed line 25 branches off from the pump feed line 10 and leads to the brake line 3 directly below the master cylinder 1.
  • a isolating valve 13 is again inserted into the brake line 3 here . If the reserve memory 11 has to be refilled, this isolating valve 13 is switched into its blocking position while the second switching valve 24 is opened.
  • the first switching valve 22 remains in its basic position shown, so that the accumulator charging line 21 connects the pressure side of the pump 8 to the reserve accumulator 11, while the suction side of the pump is only connected to the supply line 25, but not to the reserve accumulator 11.
  • the pump 8 now sucks pressure medium from the reservoir 2 via the open switching valve 24, the supply line 25 and the master cylinder 1 and conveys it into the storage charging line 21.
  • the closed isolation valve 13, the integrated pressure relief valve of which only opens when the pressure is higher than the required filling pressure of the reserve accumulator 11 prevents pressure medium from flowing out into the master cylinder 1.
  • either the inlet valve 15 can be closed or the Throttle point 23 are again designed so that the dynamic pressure is sufficient to fill the reserve memory 11. It is obvious that the brake system shown can also be used for traction control in a manner known per se.
  • FIG. 4 A further variant of how the reserve memory 11 can be filled is shown in FIG. 4.
  • the storage charging line 12 is here laid parallel to the pump supply line 10. It connects to the suction line 7 between the suction side of the pump 8 and the outlet valve 16. This arrangement enables automatic filling of the reserve memory 11.
  • a slip-controlled braking is ended, that is to say if the outlet valve 16 is opened to reduce the pressure and the volume of the low-pressure accumulator 6 no longer has to be available for further slip control, the pump 8 is switched off immediately, so that the volume of the low-pressure device pressure accumulator 6 and the escaping from the wheel brake 4 via the outlet valve 16 pressure medium in the
  • Accumulator charge line 12 arranged check valve 18 reaches the reserve memory 11.
  • the switching valve 17 remains in its closed position, so that the pressure medium cannot escape from the reserve memory 11 until it is required.

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

Abstract

ABS hydraulic brake systems which operate on the recirculation principle during an ABS operation, form a closed system. This means that no pressurised medium can get into the brake circuits from the reservoir during an ABS operation. In order to ensure reliable braking even if there is leakage into the brake circuits, the invention proposes that a reserve reservoir (11) should be provided and connected to the vacuum side of the recirculating pump (8) only if a travel sensor (20) signals that the main cylinder (1) is nearly exhausted. Various embodiments pertain to different ways of filling the reserve reservoir (11).

Description

Schlupfgeregelte hydraulische BremsanlageSlip-controlled hydraulic brake system
Die vorliegende Erfindung betrifft eine schlupfgeregelte hydraulische Bremsanlage gemäß dem Oberbegriff des Anspruchs 1.The present invention relates to a slip-controlled hydraulic brake system according to the preamble of claim 1.
Schlupfgeregelte Bremsanlagen, die nach dem Rückförderprinzip arbeiten, bilden während einer Blockierschutzregelung ein geschlossenes System, wie z.B. in der DE 37 28 480 AI. Das heißt, daß die Bremsflüssigkeitsmenge, die zu einer solchen Blockierschutzregelung zur Verfügung steht, begrenzt ist. Damit diese begrenzte Druckmittelmenge zur Bremsschlupfregelung ausreicht, muß bei einer Bremspedalbetätigung durch den Hauptzylinder ein entsprechend großes Volumen in die Bremskreise befördert werden. Wenn bei einem Defekt durch Leckage während einer Blockierschutzregelung Druckmittel verlorengeht, kann bei geschlossenen Systemen dieses Volumen nicht aus dem Vorratsbehalter nachgesaugt werden.Slip-controlled brake systems that work on the return flow principle form a closed system during an anti-lock control system, e.g. in DE 37 28 480 AI. This means that the amount of brake fluid available for such anti-lock control is limited. So that this limited amount of pressure medium is sufficient for brake slip control, a correspondingly large volume must be conveyed into the brake circuits by the master cylinder when the brake pedal is actuated. If pressure medium is lost in the event of a defect due to a leakage during anti-lock control, this volume cannot be drawn from the storage container in closed systems.
Die Aufgabe der vorliegenden Erfindung ist es, eine blockiergeschützte Bremsanlage, welche nach dem Rück¬ förderprinzip arbeitet, zu schaffen, die auch bei einer Leckage während der Blockierschutzregelung zuverlässig arbeitet.The object of the present invention is to provide an anti-lock brake system which works on the return conveyor principle and which works reliably even in the event of a leak during anti-lock control.
Diese Aufgabe wird gelöst mit einer gattungsgemäßen Bremsanlage, welche die kennzeichnenden Merkmale des Anspruchs 1 aufweist.This object is achieved with a generic brake system which has the characterizing features of claim 1.
Eine Bremsanlage nach dem Oberbegriff des Anspruches 1 ist beispielsweise aus der WO 91/18776 bekannt. Der Reservespeicher der bekannten Bremsanlage dient aber lediglich dazu, ein zusätzliches Volumen zur Antriebsschlupfregelung bereitzustellen. Ein Schaltventil in der Pumpenspeiseleitung soll daher nur bei einer Antriebsschlupfregelung öffnen. Gemäß der vorliegenden Erfindung soll das Volumen des Reservespeichers immer auch dann zur Verfügung gestellt werden, wenn das Volumen des Hauptzylinders erschöpft ist und ein weiterer Druckaufbau erwünscht ist. Wenn also aufgrund einer Leckage das zur Schlupfregelung zur Verfügung stehende Druckmittelvolumen geringer wird und das Bremspedal entsprechend tief durchgetreten wird, wird dieA brake system according to the preamble of claim 1 is known for example from WO 91/18776. The reserve memory of the known brake system is only used to provide an additional volume for traction control. A switching valve in the pump feed line should therefore only open when the traction control system is active. According to the present invention, the volume of the reserve memory should always be made available even when the volume of the master cylinder is exhausted and a further pressure build-up is desired. If, due to a leak, the pressure medium volume available for slip control becomes smaller and the brake pedal is depressed accordingly, the
Pumpenspeiseleitung geöffnet, so daß das Reservespeichervolumen zur Saugseite der Pumpe gelangt, von welcher es in die Bremskreise befördert wird. Aufgrund des hohen Pumpendruckes wird dann eine Bremsdruckregelung erfolgen, die von den Einlaß- und Auslaßventilen gesteuert wird.Pump feed line opened so that the reserve storage volume reaches the suction side of the pump, from which it is conveyed into the brake circuits. Due to the high pump pressure, brake pressure control will then take place, which is controlled by the inlet and outlet valves.
Zweckmäßigerweise wird die Notwendigkeit einer Zuschaltung des Reservespeichers von einem Wegsensor angezeigt, der am Bremspedal, am Bremskraftverstärker oder am Hauptzylinder angebracht ist.The need to connect the reserve storage is expediently indicated by a displacement sensor which is attached to the brake pedal, to the brake booster or to the master cylinder.
Ein Trennventil ist der Bremsleitung zwischen dem Hauptzylinder und der Einmündung der Druckleitung kann zu verschiedenen Zwecken verwendet werden. Es kann während einer Bremsung, zu welcher der Reservespeicher zugeschaltet wird, den Hauptzylinder vom Bremskreis abtrennen, so daß das Pedalgefühl für den Fahrer unbeeinträchtigt bleibt. Auch zu einer Antriebsschlupfregelung oder zur Ladung des Reservespeichers - wie unten näher beschrieben - kann ein solches Trennventil verwendet werden.An isolation valve is the brake line between the master cylinder and the mouth of the pressure line can be used for various purposes. It can separate the master cylinder from the brake circuit during braking, to which the reserve memory is switched on, so that the pedal feeling for the driver remains unaffected. Such a separating valve can also be used for traction control or for charging the reserve memory - as described in more detail below.
Der Reservespeicher kann dadurch geladen werden, daß eine Speicherladeleistung zwischen Hauptzylinder und Trennventil von der Bremsleitung abzweigt und das Trennventil während einer Pedalbetätigung geschlossen bleibt. Dann wird das Hauptzylindervolumen nicht in die Bremskreise, sondern über die Speicherladeleitung in den Reservespeicher befördert. Eine weitere Möglichkeit zum Laden des Speichers besteht darin, daß eine Speicherladeleitung unterhalb des Trennventils von der Bremsleitung bzw. von der Druckleitung der Pumpe abzweigt. In diesem Falle sind Ladezyklen vorgesehen, in denen das Trennventil geschlossen wird und die Pumpe Druckmittel, welche sie aus dem Vorratsbehalter angesaugt hat, über die Druckleitung und die Speicherladeleitung in den Reservespeicher verbringt.The reserve memory can be loaded in that a storage charging power between the master cylinder and the isolating valve branches off from the brake line and the isolating valve remains closed during a pedal operation. Then the master cylinder volume is not conveyed into the brake circuits, but into the reserve storage via the storage charging line. A further possibility for loading the accumulator is that a accumulator charging line branches off from the brake line or from the pressure line of the pump below the isolating valve. In this case, charging cycles are provided in which the isolating valve is closed and the pump brings pressure medium, which it has sucked out of the storage container, into the reserve storage via the pressure line and the storage charging line.
Für den Fall, daß in der Bremsleitung kein Trennventil vorgesehen ist und die Speicherladeleitung von der Druckleitung der Pumpe abzweigt, kann zwischen der Abzweigung der Speicherladeleitung und der Einmündung der Druckleitung in die Bremsleitung eine Drosselstelle vorgesehen sein, welche ein Druckgefälle zwischen der In the event that no isolating valve is provided in the brake line and the accumulator charging line branches off from the pressure line of the pump, a throttle point can be provided between the branching of the accumulator charging line and the confluence of the pressure line in the brake line, which provides a pressure drop between the
Druckleitung und der Bremsleitung herstellt, so daß der entstehende Staudruck zur Befullung des Reservespeichers genutzt werden kann. Zum Aufbau des nötigen Staudrucks kann aber auch, falls vorhanden, das Trennventil geschlossen werden.Produces pressure line and the brake line so that the resulting dynamic pressure can be used to fill the reserve memory. To build up the necessary dynamic pressure, the isolating valve can also be closed, if available.
Wenn der Reservespeicher von der Pumpe gefüllt werden soll, gibt es verschiedene Möglichkeiten, die Pumpe an den Vorratsbehalter anzuschließen. Die einfachste Möglichkeit wäre ein direkter Anschluß an den Vorratsbehalter. Hierdurch entstünde aber ein offenes System, bei welchem die Druckmittelmenge ohnehin nicht begrenzt ist, so daß ein Hilfsdruckspeicher überflüssig ist. Die Nachteile von offenen Systemen sollen mit der Erfindung gerade vermieden werden. Deshalb bietet sich an, zur Befullung des Reservespeichers beispielsweise das Auslaßventil in der Rücklaufleitung und das Einlaßventil in der Bremsleitung zu öffnen, so daß die Pumpe über die Rücklaufleitung und die Bremsleitung sowie den Hauptzylinder an den Vorratsbehalter angeschlossen ist. Diese Möglichkeit ist für Bremsanlagen ohne Trennventil geeignet. Eine andere Möglichkeit besteht darin, die Pumpenspeiseleitung statt mit nur einem mit zwei Schaltventilen auszurüsten, zwischen denen eine Zuführleitung abzweigt. Diese kann beispielsweise an die Bremsleitung zwischen Hauptzylinder und Trennventil anschließen. Bei unbetätigtem Hauptzylinder steht die Bremsleitung oberhalb des Trennventils direkt mit dem Vorratsbehalter in Verbindung, so daß die Pumpe ungehindert ansaugen kann. Bei betätigtem Hauptzylinder bleibt trotzdem ein geschlossenes System bestehen.If the reserve storage is to be filled by the pump, there are various ways of connecting the pump to the reservoir. The simplest option would be a direct connection to the storage container. This would result in an open system in which the amount of pressure medium is not limited anyway, so that an auxiliary pressure accumulator is unnecessary. The invention is intended to avoid the disadvantages of open systems. For this reason, it is advisable to open the outlet valve in the return line and the inlet valve in the brake line, for example, so that the pump is connected to the reservoir via the return line and the brake line as well as the master cylinder. This option is suitable for brake systems without a isolation valve. Another possibility is to equip the pump feed line with two switching valves instead of just one, between which a feed line branches. This can connect to the brake line between the master cylinder and the isolation valve, for example. When the master cylinder is not actuated, the brake line is connected directly to the reservoir above the isolating valve so that the pump can suck in unhindered. When the master cylinder is actuated, a closed system still remains.
Eine weitere Variante zur Ladung des Reservespeichers besteht darin, eine Speicherladeleitung zur Saugleitung zu legen, wobei in diese Speicherladeleitung ein Rückschlagventil eingefügt ist, welches in Speicherfüllrichtung öffnet. Dann kann der Reservespeicher entweder dadurch geladen werden, daß das Auslaßventil in der Rücklaufleitung geöffnet wird und eine Pedalbetätigung erfolgt oder daß bei Beendigung einer Bremsschlupfbzw. Antriebsschlupfregelung das frei werdende Druckmittel in den Reservespeicher gelangt.A further variant for charging the reserve store consists of laying a store charging line to the suction line, a check valve being inserted into this store charging line, which opens in the direction of filling the store. Then he can Reserve memory can be loaded either by opening the outlet valve in the return line and pressing the pedal, or by stopping a brake slip. Traction control the pressure medium released gets into the reserve memory.
Eine nähere Erläuterung der Erfindung erfolgt nun durch die Beschreibung von vier Ausführungsbeispielen anhand von Zeichnungen.A more detailed explanation of the invention will now be given by the description of four exemplary embodiments with reference to drawings.
Es zeigt:It shows:
Fig. 1 eine erfindungsgemäße Bremsanlage, derenFig. 1 a brake system according to the invention, the
Speicherladeleitung von der Bremsleitung zwischen Hauptzylinder und Trennventil abzweigt.Accumulator charging line branches from the brake line between the master cylinder and the isolation valve.
Fig. 2 eine erfindungsgemäße Bremsanlage bei welcher die Speicherladeleitung von der Druckleitung abzweigt,2 shows a brake system according to the invention in which the accumulator charging line branches off from the pressure line,
Fig. 3 eine erfindungsgemäße Bremsanlage, derenFig. 3 shows a brake system according to the invention, the
Speicherladeleitung von der Druckleitung abzweigt und die eine zusätzliche Nachlaufleitung vom Hauptzylinder zur Saugseite der Pumpe aufweist undStorage charging line branches off from the pressure line and which has an additional follow-up line from the master cylinder to the suction side of the pump and
Fig. 4 eine erfindungsgemäße Bremsanlage, deren Speicher¬ ladeleitung an die Saugleitung angeschlossen ist.4 shows a brake system according to the invention, the accumulator charging line of which is connected to the suction line.
In allen Fig. tragen gleiche Funktionselemente dieselben Bezugszeichen. Der Übersichtlichkeit halber ist in jeder Fig. nur ein Bremskreis dargestellt und in diesem auch nur eine Radbremse. Die bei einem vierrädrigen Fahrzeug vorgesehene zweite Radbremse pro Bremskreis schließt sich in bekannter Weise an den Bremskreis an, wobei der zweite Bremskreis analog zum ersten Bremskreis aufgebaut ist. Die hydraulische Schaltung nach Fig. 1 ähnelt in ihrem Aufbau der aus dem Stand der Technik (WO 91-18776) bekannten Schaltung. Der Hauptzylinder 1 ist auf bekannte Weise an den Vorratsbehalter 2 angeschlossen, vom Hauptzylinder 1 verläuft die Bremsleitung 3 zur Radbremse 4. Von der Radbremse 4 führt die Rücklaufleitung 5 zum Niederdruckspeicher 6. der Niederdruckspeicher 6 ist über die Saugleitung 7 mit der Saugseite der Pumpe 8 verbunden, deren Druckleitung 9 in die Bremsleitung 3 einmündet. An die Saugleitung 7 ist die Pumpenspeiseleitung 10 angeschlossen, die den Reservespeicher 11 mit der Saugseite der Pumpe 8 verbindet. Eine Speicherladeleitung 12 zweigt von der Bremsleitung 3 unmittelbar unterhalb des Hauptzylinders 1 ab und führt zum Reservespeicher 11. Zwischen der Abzweigung der Speicherladeleitung 12 und der Einmündung der Druckleitung 9 ist die Bremsleitung 3 mit einem Trennventil 13 versehen. Das Trennventil 13 ist ein elektromagnetisch betätigtes, stromlos geöffnetes 2/2-Wegeventil, das bei bestromten Elektromagneten ein Überdruckventil in die Bremsleitung 3 schaltet, welches zum Hauptzylinder 1 hin bei einem Vordruck öffnet, welcher beispielsweise zu einer Antriebsschlupfregelung in der Radbremse 4 ausreicht. Das Überdruckventil kann selbstverständlich auch separat parallel zum Trennventil 13 angelegt sein, wobei dann das Trennventil 13 in seiner Schaltstellung die Bremsleitung 3 sperrt. Um bei geschaltetem Trennventil 13 ein Einbremsen vom Hauptzylinder 1 zur Radbremse 4 zu ermöglichen, ist dem Trennventil 13 weiterhin ein Rückschlagventil 14 parallelgeschaltet.In all the figures, the same functional elements have the same reference symbols. For the sake of clarity, only one brake circuit is shown in each figure and only one wheel brake in this. The second wheel brake per brake circuit provided in a four-wheel vehicle connects to the brake circuit in a known manner, the second brake circuit being constructed analogously to the first brake circuit. 1 is similar in structure to the circuit known from the prior art (WO 91-18776). The master cylinder 1 is connected in a known manner to the reservoir 2, the brake line 3 runs from the master cylinder 1 to the wheel brake 4. From the wheel brake 4, the return line 5 leads to the low-pressure accumulator 6. The low-pressure accumulator 6 is connected to the suction side of the pump 8 via the suction line 7 connected, the pressure line 9 opens into the brake line 3. The pump feed line 10 is connected to the suction line 7 and connects the reserve memory 11 to the suction side of the pump 8. An accumulator charging line 12 branches off from the brake line 3 immediately below the master cylinder 1 and leads to the reserve memory 11. The brake line 3 is provided with a isolating valve 13 between the branching of the accumulator charging line 12 and the confluence of the pressure line 9. The isolating valve 13 is an electromagnetically actuated, normally open 2/2-way valve which, when the electromagnet is energized, switches a pressure relief valve into the brake line 3, which opens to the master cylinder 1 at an admission pressure which, for example, is sufficient for traction control in the wheel brake 4. The pressure relief valve can of course also be set up separately in parallel to the isolating valve 13, in which case the isolating valve 13 blocks the brake line 3 in its switching position. In order to enable braking from the master cylinder 1 to the wheel brake 4 when the isolating valve 13 is switched on, a check valve 14 is also connected in parallel with the isolating valve 13.
Zwischen der Einmündung der Druckleitung 9 und der Radbremse 4 ist in der Bremsleitung 3 das Einlaßventil 15 angeordnet. Dieses ist ein stromlos offenes Magnetventil, welchem ein Rückschlagventil parallelgeschaltet ist, das von der Radbremse 4 zum Hauptzylinder 1 hin öffnet. In die Rücklaufleitung 5 ist ein Auslaßventil 16 eingefügt, ein stromlos geschlossenes Magnetventil. Die Pumpenspeiseleitung 10 ist über ein ebenfalls stromlos geschlossenes 2/2-Wegemagnetventil, das Schaltventil 17 sperrbar. Damit der Reservespeicher 11 sich bei unbetätigtem Hauptzylinder 1 nicht in den Vorratsbehalter 2 entleeren kann, weist die Speicherladeleitung 12 ein Rückschlagventil 18 auf, welches vom Hauptzylinder 1 zum Reservespeicher 11 hin öffnet.Between the mouth of the pressure line 9 and the wheel brake 4, the inlet valve 15 is arranged in the brake line 3. This is a normally open solenoid valve, which is a Check valve is connected in parallel, which opens from the wheel brake 4 to the master cylinder 1. In the return line 5, an outlet valve 16 is inserted, a normally closed solenoid valve. The pump feed line 10 can be blocked via a 2/2-way solenoid valve, the switching valve 17, which is also closed when de-energized. So that the reserve memory 11 cannot drain into the storage container 2 when the master cylinder 1 is not actuated, the accumulator charging line 12 has a check valve 18, which opens from the master cylinder 1 to the reserve memory 11.
Der Hauptzylinder 1 wird zum Druckaufbau in der Bremsleitung 3 vom Bremspedal 19 betätigt. Ein Wegsensor 20 erfaßt den zurückgelegten Pedalweg. Dieser Wegsensor 20 kann beispielsweise mit dem Arbeitskolben eines Vakuumverstärkers wie dargestellt gekoppelt sein.The master cylinder 1 is actuated by the brake pedal 19 to build up pressure in the brake line 3. A distance sensor 20 detects the pedal travel. This displacement sensor 20 can, for example, be coupled to the working piston of a vacuum amplifier as shown.
Für die dargestellte Bremsanlage ergibt sich folgende Funktionsweise:The following mode of operation results for the brake system shown:
Bei Betätigung des Bremspedals 19 wird die Verbindung des Hauptzylinders 1 zum Vorratsbehalter 2 getrennt und Druckmittel aus den Arbeitskammern des HauptZylinders 1 in die zugehörigen Bremskreise verbracht. Über die Bremsleitung 3 wird in der Radbremse 4 ein Bremsdruck aufgebaut. Für den Fall, daß das Hauptzylindervolumen nahezu erschöpft ist, obwohl ein weiterer Bremsdruckaufbau erwünscht wird, signalisiert der Wegsensor '20 aufgrund der weit vorgefahrenen Position des Bremspedals 19, daß ein zusätzliches Druckmittelvolumen benötigt wird. Das Trennventil 13 wird geschlossen, und das Schaltventil 17 wird geöffnet, so daß das Volumen des Reservespeichers 11 zur Saugseite der Pumpe 8 gelangt, welche zugleich mit der Umschaltung der Ventile 13 und 17 zu laufen beginnt. Die Pumpe 8 befördert das Reservevolumen in die Bremsleitung 3 von welcher es in die Radbremse 4 gelangt. Da der Pumpendruck in der Regel höher liegt als der nötige Bremsdruck, erfolgt eine weitere Bremsdruckregelung durch die an sich bekannte Schaltung des Einlaßventils 15 und des Auslaßventils 16. Die Bremsanlage arbeitet dann wie eine bekannte blockiergeschützte Bremsanlage nach dem Rückförderprinzip.When the brake pedal 19 is actuated, the connection of the master cylinder 1 to the reservoir 2 is disconnected and pressure medium is brought out of the working chambers of the master cylinder 1 into the associated brake circuits. A brake pressure is built up in the wheel brake 4 via the brake line 3. In the event that the master cylinder volume is almost exhausted, although a further increase in brake pressure is desired, the displacement sensor '20 signals due to the advanced position of the brake pedal 19 that an additional volume of pressure medium is required. The isolating valve 13 is closed, and the switching valve 17 is opened, so that the volume of the reserve memory 11 reaches the suction side of the pump 8, which also starts to run when the valves 13 and 17 are switched. The pump 8 conveys the reserve volume into the brake line 3 from which it gets into the wheel brake 4. Since the pump pressure is generally higher than the required brake pressure, a further brake pressure control takes place through the circuit of the inlet valve 15 and the outlet valve 16, which is known per se. The brake system then works like a known anti-lock brake system according to the return flow principle.
Damit bei einer späteren Bremsung der Reservespeicher 11 erneut Druckmittel zur Verfügung stellen kann, muß er zwischenzeitlich nachgeladen werden. Aller Wahrscheinlichkeit nach erfolgen nach einer Vollbremsung zunächst mehrere leichte Bremsungen, bevor zum nächsten Mal das Reservevolumen benötigt wird. Bei solchen leichteren Bremsbetätigungen, bei welchem das Haupt¬ zylindervolumen nicht ausgeschöpft wird, gelangt über das Rückschlagventil 18 jeweils eine Teilmenge des aus dem Hauptzylinder 1 verdrängten Druckmittels in den Reservespeicher 11, aus welchem es nicht entweichen kann, solange das Schaltventil 17 geschlossen ist.So that the reserve memory 11 can again provide pressure medium when braking later, it must be reloaded in the meantime. In all likelihood, after a full stop, there will be several light stops before the reserve volume is needed again. In the case of such lighter brake applications in which the master cylinder volume is not exhausted, a partial amount of the pressure medium displaced from the master cylinder 1 reaches the reserve memory 11 via the check valve 18, from which it cannot escape as long as the switching valve 17 is closed.
Zum Nachladen des Reservespeichers kann auch ein optisches Signal vorgesehen sein, das dem Fahrzeuglenker eine Betätigung des Bremspedals empfiehlt. Dabei kann eine Schließung des Trennventils möglicherweise manuell ausgelöst werden.To recharge the reserve memory, an optical signal can also be provided, which recommends that the vehicle driver actuates the brake pedal. The isolation valve may possibly be closed manually.
Der Reservespeicher 11 kann bei dieser Bremsanlage selbstverständlich auch zu den aus dem Stand der Technik bekannten Zwecken zur Antriebsschlupfregelung herangezogen werden. Wenn die Pumpe 8 als selbstansaugende Pumpe ausgelegt ist, kann sie zusätzlich weiteres Druckmittelvolumen über das des Reservespeichers hinaus ansaugen, da während einer Antriebsschlupfregelung das Trennventil 13 in seiner Schaltstellung ist und der Hauptzylinder 1 eine freie Verbindung zum Vorratsbehalter 2 besitzt. Die Speicherladeleitung 12 dient dann als Ansaugleitung zur Antriebsschlupfregelung. Die Bremsanlage nach Fig. 2 unterscheidet sich von der nach Fig. 1 im wesentlichen dadurch, wie der Reservespeicher 11 geladen wird. Die Speicherladeleitung 21 zweigt von der Druckleitung 9 ab und führt über das als 4/2-Wegeventil gestaltete Schaltventil 22 zum Reserveschalter 11. Die Befullung des Reservespeichers 11 The reserve memory 11 can of course also be used in this brake system for the purposes known from the prior art for traction control. If the pump 8 is designed as a self-priming pump, it can additionally draw in further pressure medium volume beyond that of the reserve reservoir, since the isolating valve 13 is in its switching position during traction control and the master cylinder 1 has a free connection to the reservoir 2. The storage charging line 12 then serves as an intake line for traction control. The brake system according to FIG. 2 differs from that according to FIG. 1 essentially in how the reserve memory 11 is loaded. The accumulator charging line 21 branches off from the pressure line 9 and leads to the reserve switch 11 via the switching valve 22 designed as a 4/2-way valve. The filling of the reserve accumulator 11
erfolgt hier nicht durch Pedalbetätigung, sondern über die Pumpe 8. Dazu wird das Auslaßventil 16 in seine Durchlaßstellung geschaltet, so daß die Pumpe 8 durch die Saugleitung 7, über das Auslaßventil 16 und das Einlaßventil 15 durch die Bremsleitung 3 und den Hauptzylinder 1 aus dem Vorratsbehalter 2 Druckmittel ansaugen und in den Reservespeicher 11 befördern kann. Hierzu ist das Schaltventil 22, welches entweder die Pumpenspeiseleitung 10 oder die Speicherladeleitung 21 sperrt, in seiner Grundstellung, welche die Pumpenspeiseleitung 10 sperrt. So kann die Pumpe 8 beim Befüllen des Reservespeichers 11 nicht im Kreis fördern und dabei den Reservespeicher 11 wieder leeren. Da in der Bremsleitung 3 kein Trennventil vorgesehen ist, zweigt die Speicherladeleitung 21 von der Druckleitung 9 zwischen der Druckseite der Pumpe und einer Drosselstelle 23 ab, welche den erforderlichen Staudruck erzeugt, damit das -von der Pumpe geförderte Druckmittelvolumen nicht gleich wieder in den Haupt¬ zylinder 1 abfließt. Der maximale Fülldruck des Reserve¬ speichers 11 ist also durch den Förderdruck der Pumpe 8, den Staudruck der Drosselstelle 23 sowie den Vordruck des Rückschlagventils 18 bestimmt.takes place here not by pedal actuation, but via the pump 8. For this purpose, the outlet valve 16 is switched to its open position, so that the pump 8 through the suction line 7, via the outlet valve 16 and the inlet valve 15 through the brake line 3 and the master cylinder 1 from the Storage container 2 can suck in pressure medium and convey it into the reserve memory 11. For this purpose, the switching valve 22, which blocks either the pump feed line 10 or the accumulator charging line 21, is in its basic position, which blocks the pump feed line 10. Thus, the pump 8 cannot pump in a circle when filling the reserve memory 11 and thereby empty the reserve memory 11 again. Since no isolating valve is provided in the brake line 3, the accumulator charging line 21 branches off from the pressure line 9 between the pressure side of the pump and a throttle point 23, which generates the required dynamic pressure so that the pressure medium volume delivered by the pump does not immediately return to the main part cylinder 1 flows off. The maximum filling pressure of the reserve reservoir 11 is therefore determined by the delivery pressure of the pump 8, the back pressure of the throttle point 23 and the admission pressure of the check valve 18.
Wenn der Wegsensor 20 anzeigt, daß das Volumen des Reser¬ vespeichers 11 zur Schlupfregelung benötigt wird, schaltet das Schaltventil 22 um, so daß der Reservespeicher 11 nunmehr über die Pumpenspeiseleitung 10 mit der Saugseite der Pumpe 8 verbunden ist. Die Verbindung der Druckleitung 9 zum Reservespeicher 11 wird zugleich unterbrochen. Die Pumpe 8 fördert also das Volumen des Reservespeichers 11 nur noch in die Bremsleitung 3. Die weitere Funktionsweise der Bremsanlage ergibt sich aus der vorherigen Beschreibung von Fig. 1 sowie aus dem Stand der Technik. In Fig. 3 ist eine Bremsanlage dargestellt, deren Reservespeicher 11 wie in Fig. 2 von der Pumpe 8 aufgefüllt wird. Der Druckmittelweg, über welchen die Pumpe 8 das Druckmittel aus dem Vorratsbehalter 2 ansaugt, ist jedoch hier ein anderer. Die Pumpenspeiseleitung 10 weist zwischen dem Schaltventil 22, welches schon in Fig. 2 Verwendung findet, ein weiteres Schaltventil 24 auf, welches zwischen, dem ersten Schaltventil 22 und der Saugseite der Pumpe 8 angeordnet ist. Das Schaltventil 24 ist ein elektromagnetisch betätigtes 2/2-Wegeventil welches in seiner stromlosen Stellung geschlossen ist. Zwischen den beiden Schaltventilen 22 und 24 zweigt eine Zuführleitung 25 von der Pumpenspeiseleitung 10 ab und führt zur Bremsleitung 3 unmittelbar unterhalb des Hauptzylinders 1. Zwischen der Anknüpfung der Zuführleitung 25 und der Einmündung der Druckleitung 9 ist in die Bremsleitung 3 hier wiederum ein Trennventil 13 eingefügt. Wenn der Reservespeicher 11 nachgefüllt werden muß, wird dieses Trennventil 13 in seine Sperrstellung umgeschaltet, während das zweite Schaltventil 24 geöffnet wird. Das erste Schaltventil 22 verbleibt in seiner dargestellten Grundstellung, so daß die Speicherladeleitung 21 die Druckseite der Pumpe 8 mit dem Reservespeicher 11 verbindet, während die Saugseite der Pumpe lediglich mit der Zuführleitung 25, nicht aber mit dem Reservespeicher 11 verbunden ist. Die Pumpe 8 saugt nun über das geöffnete Schaltventil 24, die Zuführleitung 25 und den Hauptzylinder 1 Druckmittel aus dem Vorratsbehalter 2 an und fördert es in die Speicherladeleitung 21. Das geschlossene Trennventil 13, dessen integriertes Überdruckventil erst bei einem Überdruck öffnet, der höher liegt als der erforderliche Fülldruck des Reservespeichers 11, verhindert ein Abströmen von Druckmittel in den Hauptzylinder 1. Damit das von der Pumpe 8 geförderte Druckmittel nicht in die Radbremse 4 gelangt, kann entweder das Einlaßventil 15 geschlossen werden oder aber die Drosselstelle 23 wieder so ausgelegt werden, daß der Staudruck zur Befullung des Reservespeichers 11 ausreicht. Daß die dargestellte Bremsanlage auf an sich bekannte Weise auch zur Antriebsschlupfregelung herangezogen werden kann, liegt auf der Hand.If the displacement sensor 20 indicates that the volume of the reserve memory 11 is required for slip control, the switching valve 22 switches over, so that the reserve memory 11 is now connected to the suction side of the pump 8 via the pump feed line 10. The connection of the pressure line 9 to the reserve memory 11 is interrupted at the same time. The pump 8 therefore only conveys the volume of the reserve storage 11 into the brake line 3. The further functioning of the brake system results from the previous description of FIG. 1 and from the prior art. In Fig. 3, a brake system is shown, the reserve memory 11 is filled by the pump 8 as in Fig. 2. The pressure medium path, via which the pump 8 sucks the pressure medium from the storage container 2, is different here. The pump feed line 10 has a further switching valve 24 between the switching valve 22, which is already used in FIG. 2, which is arranged between the first switching valve 22 and the suction side of the pump 8. The switching valve 24 is an electromagnetically operated 2/2-way valve which is closed in its de-energized position. Between the two switching valves 22 and 24, a feed line 25 branches off from the pump feed line 10 and leads to the brake line 3 directly below the master cylinder 1. Between the connection of the feed line 25 and the confluence of the pressure line 9, a isolating valve 13 is again inserted into the brake line 3 here . If the reserve memory 11 has to be refilled, this isolating valve 13 is switched into its blocking position while the second switching valve 24 is opened. The first switching valve 22 remains in its basic position shown, so that the accumulator charging line 21 connects the pressure side of the pump 8 to the reserve accumulator 11, while the suction side of the pump is only connected to the supply line 25, but not to the reserve accumulator 11. The pump 8 now sucks pressure medium from the reservoir 2 via the open switching valve 24, the supply line 25 and the master cylinder 1 and conveys it into the storage charging line 21. The closed isolation valve 13, the integrated pressure relief valve of which only opens when the pressure is higher than the required filling pressure of the reserve accumulator 11 prevents pressure medium from flowing out into the master cylinder 1. In order that the pressure medium conveyed by the pump 8 does not get into the wheel brake 4, either the inlet valve 15 can be closed or the Throttle point 23 are again designed so that the dynamic pressure is sufficient to fill the reserve memory 11. It is obvious that the brake system shown can also be used for traction control in a manner known per se.
Eine weitere Variante, wie der Reservespeicher 11 aufgefüllt werden kann, zeigt Fig. 4. Die Speicherladeleitung 12 ist hier parallel zur Pumpenspeiseleitung 10 angelegt. Sie knüpft also an die Saugleitung 7 zwischen Saugseite der Pumpe 8 und dem Auslaßventil 16 an. Durch diese Anordnung wird eine automatische Befullung des Reservespeichers 11 ermöglicht. Bei Beendigung einer schlupfgeregelten Bremsung, wenn also das Auslaßventil 16 zum Druckabbau geöffnet wird und das Volumen des Niederdruckspeichers 6 nicht mehr für eine weitere Schlupf¬ regelung zur Verfügung stehen muß, wird die Pumpe 8 un¬ verzüglich abgeschaltet, so daß das Volumen des Nieder¬ druckspeichers 6 sowie das über das Auslaßventil 16 aus der Radbremse 4 entweichende Druckmittel über das in der A further variant of how the reserve memory 11 can be filled is shown in FIG. 4. The storage charging line 12 is here laid parallel to the pump supply line 10. It connects to the suction line 7 between the suction side of the pump 8 and the outlet valve 16. This arrangement enables automatic filling of the reserve memory 11. When a slip-controlled braking is ended, that is to say if the outlet valve 16 is opened to reduce the pressure and the volume of the low-pressure accumulator 6 no longer has to be available for further slip control, the pump 8 is switched off immediately, so that the volume of the low-pressure device pressure accumulator 6 and the escaping from the wheel brake 4 via the outlet valve 16 pressure medium in the
Speicherladeleitung 12 angeordnete Rückschlagventil 18 in den Reservespeicher 11 gelangt. Das Schaltventil 17 verbleibt in seiner geschlossenen Stellung, so daß das Druckmittel aus dem Reservespeicher 11 nicht entweichen kann, bis es benötigt wird. Accumulator charge line 12 arranged check valve 18 reaches the reserve memory 11. The switching valve 17 remains in its closed position, so that the pressure medium cannot escape from the reserve memory 11 until it is required.
BezugszeichenlisteReference list
1 Hauptzylinder1 master cylinder
2 Vorratsbehalter2 storage containers
3 Bremsleitung3 brake line
4 Radbremse4 wheel brake
5 Rücklaufleitung5 return line
6 Niederdruckspeicher6 low pressure accumulators
7 Saugleitung7 suction line
8 Pumpe8 pump
9 Druckleitung9 pressure line
10 Pumpenspeiseleitung10 pump feed line
11 Reservespeicher11 reserve memory
12 Speicherladeleitung12 storage charging line
13 Trennventi113 isolation valve 1
14 Rückschlagventil14 check valve
15 Einlaßventil15 inlet valve
16 Auslaßventil16 exhaust valve
17 Schaltventil17 switching valve
18 Rückschlagventil18 check valve
19 Bremspedal19 brake pedal
20 Wegsensor20 displacement sensor
21 Speicherladeleitung21 storage charging line
22 Schaltventil22 switching valve
23 Drosselstelle23 throttling point
24 Schaltventil24 switching valve
25 Zuführleitung 25 supply line

Claims

Patentansprüche claims
Schlupfgeregelte hydraulische Bremsanlage mit einem von einem Vorratsbehalter (2) gespeisten, pedalbetätigten Hauptzylinder (1) , mit mindestens einer Radbremse (4) , mit einer Bremsleitung (3) vom Hauptzylinder (1) zur Radbremse (4), mit einem Niederdruckspeicher (6), mit einer Rücklaufleitung (5) von der Radbremse (4) zum Niederdruckspeicher (6) mit einer Pumpe (8) , deren Saugseite über eine Saugleitung (7) mit dem Niederdruckspeicher (6) und deren Druckseite über eine Druckleitung (9) mit der Bremsleitung (3) in Verbindung steht und mit einem Einlaßventil (15) in der Bremsleitung (3) und einem Auslaßventil (16) in der Rücklaufleitung (5) sowie mit einem über eine sperrbare Pumpenspeiseleitung (10) an die Saugleitung (7) angeschlossenen Reservespeicher (11), dadurch g e k e n n z e i c h - n e t, daß der Reservespeicher (11) zugeschaltet wird, wenn ein Sensor (20) signalisiert, daß das Hauptzylindervolumen nahezu erschöpft ist.Slip-controlled hydraulic brake system with a pedal-operated master cylinder (1) fed by a reservoir (2), with at least one wheel brake (4), with a brake line (3) from the master cylinder (1) to the wheel brake (4), with a low-pressure accumulator (6) , with a return line (5) from the wheel brake (4) to the low pressure accumulator (6) with a pump (8), the suction side of which via a suction line (7) with the low pressure accumulator (6) and the pressure side via a pressure line (9) with the Brake line (3) is connected and with an inlet valve (15) in the brake line (3) and an outlet valve (16) in the return line (5) and with a reserve reservoir connected to the suction line (7) via a lockable pump feed line (10) (11), characterized in that the reserve memory (11) is switched on when a sensor (20) signals that the master cylinder volume is almost exhausted.
Bremsanlage nach Anspruch 1, dadurch g e ¬ k e n n z e i c h n e t, daß der Sensor ein Wegsensor (20) ist.Brake system according to claim 1, characterized in that the sensor is a displacement sensor (20).
Bremsanlage nach Anspruch 1 oder 2, dadurch g e ¬ k e n n z e i c h n e t, daß in der Bremsleitung (3) zwischen Hauptzylinder (1) und Einmündung der Druck¬ leitung (9) ein Trennventil (13) angeordnet ist. Brake system according to claim 1 or 2, characterized in that a separating valve (13) is arranged in the brake line (3) between the master cylinder (1) and the mouth of the pressure line (9).
4. Bremsanlage nach Anspruch 3, dadurch g e - k e n n z e i c h n e t, daß der Reservespeicher (119) über eine Speicherladeleitung (12) an die Bremsleitung (3) zwischen Hauptzylinder (1) und Trennventil (13) angeschlossen ist.4. Brake system according to claim 3, characterized in that the reserve memory (119) is connected to the brake line (3) between the master cylinder (1) and the isolating valve (13) via a memory charging line (12).
5. Bremsanlage nach einem der Ansprüche 1 bis 3, dadurch g e k e n n z e i c h n e t, daß der Reservespeicher (11) über eine Speicherladeleitung (21) an die Druckleitung (9) angeschlossen ist, wobei Mittel (23) vorgesehen sind, die bei laufender Pumpe (8) und unbetätigtem Hauptzylinder (1) ein Druckgefälle zwischen Pumpe (8) und Hauptzylinder (1) erzeugen.5. Brake system according to one of claims 1 to 3, characterized in that the reserve memory (11) is connected via a memory charging line (21) to the pressure line (9), means (23) being provided which are in operation when the pump (8) is running. and unactuated master cylinder (1) generate a pressure drop between pump (8) and master cylinder (1).
6. Bremsanlage nach Anspruch 5, dadurch g e ¬ k e n n z e i c h n e t, daß das Druckgefälle von einer Drosselstelle (23) in der Druckleitung (9) erzeugt wird.6. Brake system according to claim 5, characterized in that the pressure gradient is generated by a throttle point (23) in the pressure line (9).
7. Bremsanlage nach Anspruch 5, dadurch g e k e n n ¬ z e i c h n e t, daß das Druckgefälle durch ein Trennventil (13) in der Bremsleitung (3) erzeugt wird.7. Brake system according to claim 5, characterized in that the pressure drop is generated by a isolating valve (13) in the brake line (3).
8. Bremsanlage nach einem der Ansprüche, dadurch g e k e n n z e i c h n e t, daß in der Pumpen¬ speiseleitung (10) zwei Schaltventile (22,24) angelegt sind, zwischen denen eine Zuführleitung (25) abzweigt, die zumindest bei unbetätigtem Hauptzylinder (1) mit dem Vorratsbehalter (2) in Verbindung steht. Bremsanlage nach einem der Ansprüche 1 bis 3, dadurch g e k e n n z e i c h n e t, daß eine Speicherladeleitung (26) von der Saugleitung (7) abzweigt und mit einem zum Reservespeicher (11) hin öffnenden Rückschlagventil (18) versehen ist. 8. Brake system according to one of the claims, characterized in that in the Pumpen¬ feed line (10) two switching valves (22, 24) are created, between which a feed line (25) branches off, which at least when the master cylinder (1) is not actuated, with the reservoir (2) communicates. Brake system according to one of claims 1 to 3, characterized in that a storage charging line (26) branches off from the suction line (7) and is provided with a check valve (18) opening towards the reserve storage (11).
PCT/EP1995/002671 1994-07-01 1995-07-08 Abs hydraulic brake system WO1997002973A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DE4423086A DE4423086A1 (en) 1994-07-01 1994-07-01 Slip control hydraulic brake mechanism
DE59505314T DE59505314D1 (en) 1995-07-08 1995-07-08 SLIP-CONTROLLED HYDRAULIC BRAKE SYSTEM
PCT/EP1995/002671 WO1997002973A1 (en) 1994-07-01 1995-07-08 Abs hydraulic brake system
EP95925851A EP0784554B1 (en) 1995-07-08 1995-07-08 Abs hydraulic brake system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4423086A DE4423086A1 (en) 1994-07-01 1994-07-01 Slip control hydraulic brake mechanism
PCT/EP1995/002671 WO1997002973A1 (en) 1994-07-01 1995-07-08 Abs hydraulic brake system

Publications (1)

Publication Number Publication Date
WO1997002973A1 true WO1997002973A1 (en) 1997-01-30

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1995/002671 WO1997002973A1 (en) 1994-07-01 1995-07-08 Abs hydraulic brake system

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DE (1) DE4423086A1 (en)
WO (1) WO1997002973A1 (en)

Families Citing this family (4)

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Publication number Priority date Publication date Assignee Title
JP2000335391A (en) 1999-03-25 2000-12-05 Aisin Seiki Co Ltd Vehicle braking force control device
DE19939035B4 (en) * 1999-08-18 2006-04-20 Knorr-Bremse Systeme für Nutzfahrzeuge GmbH Brake system for vehicles, especially commercial vehicles
DE10337957A1 (en) * 2003-08-19 2005-03-17 Bayerische Motoren Werke Ag Hydraulic vehicle brake system comprises a further hydraulic effective pressure storage which can be coupled to the hydraulic connection between the separation valve and the main brake cylinder
DE102012023319A1 (en) 2012-11-29 2014-06-05 Lucas Automotive Gmbh Braking system for a land vehicle and method for controlling the braking system

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