DE102008064942B3 - Central pressure supply for power take-offs (multiplex operation) - Google Patents

Abstract

Pressure supply device for a motor vehicle, comprising: - at least one piston-cylinder unit (4) for building up hydraulic pressure in at least one hydraulic line (40), - a drive for driving a piston (3) of the piston-cylinder unit (4) The pressure supply device is used to build up and reduce brake pressure in at least one wheel brake, the pressure supply device with the piston-cylinder unit (4) in addition to the wheel brakes at least one hydraulically acting and / or driven device (E1, E2, E3, E4) of the Motor vehicle supplied via a pressure transmitter (41) and / or by means of a pressure accumulator (44), while the at least one device (E1, E2, E3, E4) is being supplied via the pressure transmitter (41) or while the pressure accumulator (44) is being charged a connecting line between the piston-cylinder unit (4) and the wheel brakes can be separated or closed by means of at least one valve (8, 8a).

Description

The present invention relates to a pressure supply device for a motor vehicle with at least one piston-cylinder unit for building up hydraulic pressure in at least one hydraulic line.

State of the art

When faced with the challenge of reducing CO ₂ , many vehicle assemblies and systems are forced to reduce costs and weight. In terms of weight, in addition to the installation weight, the additional energy and CO ₂ load for the production of additional weight must be taken into account. Many functions are now decentralized. These include in particular the starter control management, clutch, level control and the windscreen washer system with a separate electrically operated pump. These drives all have greater power and weight.

Systems with several hydraulic working groups are, for example, from the publication DE 195 38 974 A1 or the patent specification DE 27 03 747 B1 known.

The object of the invention is to save weight and / or costs for drives present in the motor vehicle.

This object is achieved according to the invention with a pressure generating device having the features of claim 1. Advantageous embodiments of the pressure generating device result from the features of the subclaims.

The basic idea of the invention is to use the pressure generating device of the brake system for the provision of pressure or pressure regulation for additional devices of the motor vehicle. Devices within the meaning of the invention can include the clutch, windshield wiper system, level control and starter.

So that there is no pressure change in the wheel brakes while the devices are being pressurized, at least one valve is advantageously provided for hydraulic decoupling. In the simplest case, the wheel switching valves arranged in the hydraulic lines of the respective wheel brakes can be used for decoupling. If the wheel shift valves are closed, the pressure in the wheel brakes cannot change and the pressure generating device with its piston-cylinder unit driven by a drive can be used to provide pressure in the device or devices.

The brake booster (BKV) with its tandem stroke cylinder (THZ), which is controlled in an oscillating manner for the supply of pressure medium, is advantageous as the pressure supply device. The drive of the tandem lift cylinder is advantageously an electric motor with sufficiently high dynamics so that the respective wheel brake pressure can be built up or reduced when the wheel shift valves are open. The pressure in the wheel brakes can take place individually one after the other in the sense of a multiplex method or simultaneously. Corresponding switching means, including the wheel shift valves already described, must be provided. A corresponding braking system is exemplified in FIG DE 10 2007 015 809 A1 previously known.

The invention provides that the at least one additional device, which is supplied with hydraulic medium or hydraulic pressure by means of the pressure supply device of the brake booster, by means of a hydraulic supply line to the working chamber of the piston-cylinder unit or a hydraulic line connecting the piston-cylinder unit to the wheel brakes is connected. This connection can be opened, interrupted or closed by means of a valve. In the simplest case, the valve can be a 2/2-way switching valve. Basically, two possible types of supply are possible, which can be used alternatively or in combination. Thus, an additional pressure storage device and / or a pressure transmitter can be provided. The pressure accumulator device can advantageously be a pressure accumulator which is connected to the connecting line which connects the piston-cylinder unit to at least one device. The pressure accumulator can be charged through the previously described and opened valve. As soon as the valve is closed, charging of the pressure accumulator is temporarily terminated and the piston-cylinder unit can be used again for the braking system. If a control signal is generated for the brake system during charging, the brake system has priority until a certain brake pressure level is reached. After the pressure level has been reached, a short break can be used to recharge the accumulator.

The pressure in one of the hydraulic lines can be determined by means of a pressure transducer, in particular arranged in the hydraulic line to the wheel brakes or in the pressure accumulator, the movement of the piston of the piston-cylinder unit being briefly interrupted for static pressure measurement. If the pressure transducer is arranged in the pressure accumulator, it measures the actual pressure so that the movement of the piston of the piston-cylinder unit only has to be briefly interrupted, if at all, for pressure measurement.

In the embodiment described above, a further pressure build-up valve is to be provided between the pressure accumulator and each device, which regulates the pressure for the respective device, if necessary by means of pulse width modulation. The respective devices or drives for pressure reduction can be connected to a storage container via pressure reduction valves. The reservoir is advantageously the reservoir for the brake system.

If a pressure transmitter is provided, a shut-off valve must also be provided between the pressure transmitter and each device so that the individual devices can be controlled individually. If only one device is supplied with hydraulic medium via the pressure transmitter, the corresponding valve can be dispensed with. A check valve can advantageously be arranged at the outlet of the pressure transmitter, which prevents hydraulic medium from flowing back into the transmitter from the devices. The pressure transmitter advantageously has a strong return spring so that it can follow the THZ piston of the BKV during the return movement and has an equally high dynamic. By means of a further check valve, hydraulic medium can be replenished from a reservoir into the working space of the pressure transmitter on the output side when the piston-cylinder unit is moved back accordingly. The pressure transmitter acts like a hydraulically controlled pump. The delivery volume should be selected to be relatively small so that if the valve 13 for decoupling the devices and the brake circuit fails, there is no significant impairment of the brake circuit. With the system described above, hydraulic volume is conveyed to the pressure transmitter via the pressure piston of the brake booster when the wheel brake valves are closed, which in turn controls the individual drives. When the control via the pressure transmitter is complete, the corresponding volume is fed back into the brake circuit by a return spring of the pressure transmitter. If the control signal for pressure transmission occurs at the same time as the start of braking, the brake has priority until a certain pressure level is reached. Then, if necessary, the braking can be briefly interrupted to control the respective drive.

As already mentioned before, some devices can be supplied with hydraulic pressure or hydraulic medium by means of a pressure accumulator charged by the piston-cylinder unit. Alternatively, the pressure accumulator described can be provided for at least one device. Depending on the requirements, devices can also be supplied via the pressure accumulator and other devices via the pressure transmitter. In this combined embodiment, the two devices are to be decoupled by means of appropriate switching means / valves.

The drives of the devices are selected so that braking priority is not a problem. The memory (s) are only loaded during the braking breaks.

A media separation between the hydraulic medium of the piston-cylinder unit and the medium of the device can advantageously take place in the drive of a device. The media can be separated by means of a piston-cylinder system with two working spaces separated by a piston

At least some or all of the valves and / or the pressure accumulator or the pressure transmitter are advantageously arranged in a module or housing, in particular together with the ABS and / or ESP valves of the vehicle braking system. The wheel shift valves and / or the pressure transducer can also be arranged in the module or housing.

Pressure transmitters and solenoid valves are particularly preferably integrated in one block together with the ABS solenoid valves and screwed onto the THZ, so that the cable set is also reduced. In addition, the functions are fully diagnosable. Similar to the trend of integrating control units into so-called domains, electro-hydraulic integration of the control of various drives is also possible here.

As already stated, a device can be the drive for the starter of the motor vehicle. This replaces the heavy engagement relay of the conventional starter. To start the engine, the pressure transmitter conveys the corresponding volume to a piston via a solenoid valve. This piston is connected with a Bowden cable to the engagement lever of the starter, which then triggers the engagement process and the engine is switched on. The Bowden cable is advantageous compared to the conventional pressure line to the moving or vibrating internal combustion engine. The advantage over the conventional starter drive is a considerable weight reduction. In addition, the timing of the engagement and disengagement can advantageously be changed by appropriate PWM operation of the solenoid valve.

A hydraulic drive for the motor vehicle clutch can also be implemented with the device according to the invention. Here the pressure transmitter replaces the clutch master cylinder with pedal, pedal bracket and position transmitter. The pressure medium reaches the conventional slave cylinder on the clutch, which is usually on the Engaging lever acts. This enables a very cost-effective automatic clutch actuation, which also has advantages for the driver, since the clutch process, as known from the prior art, for example in the Auto Smart®, is controlled automatically. A switch on the gear lever is required for this. With start-stop systems and electric parking brake with starting aid, the drive according to the invention can be automatically engaged and disengaged. The motor vehicle manufacturer also advantageously does not have to provide two variants for manual and automatic transmissions, which also saves weight and costs. Here, too, the brake initially has priority when braking at the same time. If the clutch is to be disengaged in ABS operation at the same time, there is a brief one-time interruption in the pressure build-up for the short activation time of the clutch of less than 30 ms, which does not cause any disadvantages.

The device can also be a drive for the windshield washer system. An electrically driven pump is conventionally used here, which pumps the detergent from a storage container to the spray nozzles. According to the idea of the invention, the pressure transmitter acts on a delivery piston via a solenoid valve, which then injects the corresponding volume. The advantage lies in the lower weight and the possibility of using higher pressures for cleaning the windows.

A level control drive can also be driven. An electromotive pump with control valves is traditionally required. According to the invention, the drive of the level control has a pressure transmitter with a stepped piston, which is used as the oscillating piston pump. This is combined with the storage tank, which also holds a special hydraulic fluid for level control. Here, too, considerable cost and weight are saved.

Two possible embodiments of the invention are explained in more detail below with reference to drawings.

• 1: Erste Ausführungsform der erfindungsgemäßen Druckversorgungseinrichtung für vier Einrichtungen mittels eines Druckübertragers;
• 2: Zweite Ausführungsform der erfindungsgemäßen Druckversorgungseinrichtung für vier Einrichtungen mit einem Druckspeicher.

Show it:

• 1 : First embodiment of the pressure supply device according to the invention for four devices by means of a pressure transmitter;
• 2 : Second embodiment of the pressure supply device according to the invention for four devices with a pressure accumulator.

The 1 shows a section of the electromotive brake booster (BKV) at the top left 2 , the Indian DE 10 2007 0158 094 is disclosed and to which reference is made here in its entirety. The BKV has a THZ 4th as well as a storage container 6th on. Normally, without driver assistance functions such. B. automatic braking, the BKV 2 from the brake pedal 1 with pedal travel sensor 5 activated. The exit line 40 of the THZ 4th with plunger 3 leads on the one hand via the control valves 8th and 8a to the brakes (not shown) and additionally via a hydraulic supply line L ₁ in which a 2/2-way valve 13th is arranged on the input side to the pressure transmitter 41 with stepped piston 9 . This is necessary because the powered drives E1 to E4 have a relatively small volume and a low pressure level, e.g. B. work less than 30 bar and the THZ generates pressures of greater than 200 bar. Therefore are from the DK piston 3 to promote only small tax volumes in the event that z. B. the clutch piston 21st in the "extreme case" must be activated during braking. The pressure transmitter 41 is on the output side with the pressure supply lines 27 connected and promotes through this to the facilities E1 to E4. Funding takes place only when the control valves are closed 8th and 8a so that there is no reaction on the wheel brakes (not shown).

In the pressure supply lines 27 is between the pressure transmitter 41 and the devices E1 to E4 are each a controlled 2/2-way valve 17th , 25th , 28 and 33 arranged so that the devices E1 to E4 can be controlled or driven individually.

To drive the drive of the starter control, the pressure transmitter delivers via the open valve 17th into the working area and adjusts the piston 14th , making the connecting bolt 15th the bowden cable 18th and thus the engagement lever, moved to the gear. In the simplest case, this lever also operates the main switch for the starter motor. After the engine is running, the DK piston moves 3 back while at the same time the return spring 16 the piston 14th adjusted to its initial position and the piston 14th the volume via the return valve 43 back to the pressure transmitter 41 . The brake circuit thus remains closed. The delivery volumes are small, which means that even if the return delivery fails, braking that is subsequently required is not endangered. A replenishment of hydraulic medium from the reservoir 6th can via the check valve 12th by adjusting the piston of the pressure transducer accordingly by activating the THZ drive 4th respectively.

With the solution with a pressure accumulator 44 can use all valves 17th to 45d can be controlled by PWM, so that the time behavior of the drives can be varied within wide limits. With the solution with a pressure transmitter 41 the behavior of the drives of the devices E1 to E4 is determined by the time behavior of the THZ 4th specified by the BKV. Here it is sufficient if only the valves 17th and 35 in the PWM Operation. Braking has first priority in all control processes for the drives. In the rare event that the brake and starter or other subsequent drives are actuated at the same time, the brake continues to have first priority and the starting process is delayed by the time the brake pressure builds up, which is around 50 ms on average. Compared to the entire starting process, 50 ms is only 10% of the time actually required. A starting process starting 50 ms later is therefore not decisive.

The pressure transmitter 7th monitors the control processes. For example, it signals the end of the brake pressure build-up and recognizes the end of the return of the pressure transmitter and controls the speed of the DK piston return during this process 3 so that there is no negative pressure in the THZ 4th arises. The drives or devices described below are controlled similarly.

To control the clutch E2, ie to open the clutch, the piston 21st via the switching valve 25th from the pressure transmitter 41 provided. The way of the piston 21st , the so-called slave cylinder, by means of the sensor 23 measured. After disengaging the pressure transmitter 41 switched off again, ie moved back. Here is the check valve 11 closed and the suction valve 12th open according to the negative pressure during the return movement. The clutch E2 is therefore independent of the pressure transmitter after it has been opened 41 . The same applies to the braking system. The process of clutch actuation with resetting of the pressure transmitter 41 takes less than 50 ms, so z. B. with ABS operation in between in a phase of maintaining constant pressure briefly actuated the clutch or interrupted the pressure build-up. The clutch is closed by opening the valve 24 which is the volume in the return line 47 directs. Here, too, the temporal process can be controlled via PWM operation of the valve 24 be regulated, which is very important for the comfort of the coupling process.

In the case of a conventional clutch, a relatively large electric motor with a gearbox is necessary, since the clutching and disengaging processes take place with rapid regulation. This is the main reason why it is not widely used in the market. The control processes of the automatic clutch are known and will not be described separately.

The third device E3 is the windshield washer system. Here is when the valve is open 28 the volume passed through the piston-cylinder system 26a, whereby the delivery piston 26th the washing liquid from the storage tank 29 conveyed to the spray nozzles. When the washing is finished, the pressure transmitter moves 41 back, since the delivery piston, via the return spring, is identical to the first drive E1 and the volume to the pressure transmitter 41 sends when the return line is open.

The fourth device E4 is the level control, which conventionally requires a complex pump with an electric motor and control. Here, too, comes from the pressure transmitter 41 over the valve 33 Pressure medium to the stepped piston 32 , which from the storage container 30th the volume via the check valve 36 promoted to the hydraulic struts. Since these take up a large volume, the stepped piston needs several piston strokes 32 necessary. The DK piston is for this purpose 3 to drive for an oscillating movement, which is about the transformer 41 on the stepped piston 32 transfers until the required level is reached. The level is reduced via the 2/2 outlet valve 35 .

The electrical connections of the actuators and sensors are marked with an arrow and are connected to a control unit (not shown), which is preferably that of the brake system with BKV and ABS / ESP and is expanded for simple control processes. This also considerably simplifies the cable set and reduces the number of control devices and electrical actuators, since the clutch control and level regulation have previously had separate control devices.

All functions can be diagnosed using the various sensors.

The 2 shows a second embodiment of the pressure supply device according to the invention for four devices with a pressure accumulator 44 . It has been shown that a small low-pressure accumulator is sufficient for the devices E1 to E4 44 of up to 20 cm ^{3 to be} provided. This makes the accumulator cost-effective if it is also designed for medium pressure up to 60 bar in accordance with the coupling. This is filled by activating the BKV accordingly 2 with THZ 4th as they are already in 1 have been described in detail. That from THZ 4th The pumped volume reaches the 2/2-way switching valve 13th to the store 44 , the pressure level via the pressure transmitter 7th is monitored. In the 1 described devices E1 to E4 are from this memory 44 provided. The memory 44 is done by closing the valve 13th not supplied during braking so that braking remains unaffected. All consumers E1 to E4 require a pressure build-up valve and a pressure relief valve.

The drive 14th , 15th , 16 , 17th the device E1 is thus by means of the pressure build-up valve 17th and the pressure relief valve 45a controlled. The drive 21st the Clutch E2 is activated by means of the pressure build-up valve 25th and the pressure relief valve 45b controlled. The drive 26th the spray system E3 is activated by means of the pressure build-up valve 28 and the pressure relief valve 45c controlled. The drive 32 the level control E4 is activated by means of the pressure build-up valve 33 and the pressure relief valve 45d controlled.

All switching valves can have the same structure as the ABS anti-lock braking system and are very inexpensive.

• Ausführungsbeispiel 1:
  • Druckversorgungseinrichtung für ein Kraftfahrzeug mit mindestens einer Kolben-Zylinder-Einheit 3,4 zum Aufbau eines hydraulischen Drucks in mindestens einer Hydraulikleitung 40, wobei der Kolben 3 der Kolben-Zylinder-Einheit 4 von einem Antrieb angetrieben ist, und die Druckversorgungseinrichtung zum Bremsdruckaufbau und Bremsdruckabbau in mindestens einer Radbremse dient, wobei jeder Radbremse ein Radschaltventil 8, 8a zugeordnet ist und der Bremsdruck durch Schließen des der Radbremse zugeordneten Radschaltventils 8, 8a in der Radbremse aufrechterhaltbar und bei geöffnetem Radschaltventil 8, 8a der Druck in der jeweiligen Radbremse mittels entsprechender Ansteuerung des Antriebs einstellbar oder einregelbar ist, wobei die Druckversorgungseinrichtung mit ihrer angetriebenen Kolben-Zylinder-Einheit 3, 4 zusätzlich zu den Radbremsen mindestens eine hydraulisch wirkende und/oder angetriebene Einrichtung E1, E2, E3, E4 des Kraftfahrzeugs über einen Druckübertrager 41 und/oder mittels eines Druckspeichers 44 versorgt, wobei während der Versorgung der mindestens einen Einrichtung E1, E2, E3, E4) über den Druckübertrager oder während des Aufladens des Druckspeichers 44 mittels mindestens eines Ventils 8, 8a die Verbindungsleitung 40a zwischen der Kolben-Zylinder-Einheit 4 und den Radbremsen trennbar bzw. verschließbar ist.
• Ausführungsbeispiel 2:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 1, wobei die Kolben-Zylinder-Einheit 3, 4 mehrere hydraulisch wirkende und/oder angetriebene Einrichtung E1, E2, E3, E4 des Kraftfahrzeugs gleichzeitig, einzeln oder in Gruppen antreibt und/oder mit unter Druck stehendem Hydraulikmedium versorgt und/oder den Hydraulikdruck in den Einrichtungen E1, E2, E3, E4 auf- oder abbaut.
• Ausführungsbeispiel 3:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 1 oder 2, wobei die Trennung der Verbindung der Versorgungshydraulikleitung zu den Radbremsen mittels der Radschaltventile 8, 8a erfolgt.
• Ausführungsbeispiel 4:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 1 oder 2, wobei die Trennung der Verbindung der Versorgungshydraulikleitung zu den Radbremsen mittels eines gesteuerten 3/2-Wege-Ventils zur wahlweisen Verbindung der Kolben-Zylinder-Einheit mit den Radbremsen oder der mindestens einen Versorgungshydraulikleitung erfolgt.
• Ausführungsbeispiel 5:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 1, wobei die Kolben-Zylinder-Einheit 3, 4 mit ihrem Antrieb Teil einer Bremsanlage des Kraftfahrzeugs ist.
• Ausführungsbeispiel 6:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei der Antrieb ein Elektromotor, insbesondere ein hochdynamischer Elektromotor, ist.
• Ausführungsbeispiel 7:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei die Einrichtung E1 der Antrieb für den Anlasser des Fahrzeugs ist.
• Ausführungsbeispiel 8:
  • Druckversorgungseinrichtung nach einem der Ausführungsbeispiele 1 bis 6, wobei die Einrichtung E2 der Antrieb für die Kupplung des Fahrzeugs, insbesondere für eine automatisch gesteuerte Kupplungsbetätigung, ist.
• Ausführungsbeispiel 9:
  • Druckversorgungseinrichtung nach einem der Ausführungsbeispiele 1 bis 6, wobei die Einrichtung E3 die Druckerzeugungseinrichtung für die Reinigungsflüssigkeit der Scheibenwischanlage oder die Druckerzeugungseinrichtung für das Hydraulikmedium der Fahrzeug-Niveauregulierung ist.
• Ausführungsbeispiel 10:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei die mindestens eine Hydraulikversorgungsleitung L₁ mit dem Arbeitsraum der Kolben-Zylinder-Einheit 4 oder über eine Hydraulikleitung 40, die die Kolben-Zylinder-Einheit 4 mit den Radbremsen verbindet, verbunden oder insbesondere mittels eines Ventils verbindbar ist.
• Ausführungsbeispiel 11:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei in der die Kolben-Zylinder-Einheit 4 mit mindestens einer Einrichtung E1, E2, E3, E4 verbindenden Versorgungshydraulikleitung L₁ mindestens ein Ventil 13 zum wahlweisen Verschließen oder Öffnen der Versorgungshydraulikleitung L₁ angeordnet ist.
• Ausführungsbeispiel 12:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei mindestens eine Speichereinrichtung 44, insbesondere ein Druckspeicher, für Hydraulikmedium für mindestens eine Einrichtung E1, E2, E3, E4 vorhanden ist, und die Speichereinrichtung 44 mit einer Versorgungshydraulikleitung L₁ in Verbindung ist oder mit dieser mittels eines Ventils in Verbindung bringbar ist
• Ausführungsbeispiel 13:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 12, wobei mittels des Ventils 13 die Verbindung zwischen Speichereinrichtung 44 und Kolben-Zylinder-Einheit 4 trennbar ist, wobei das Ventil 13 zur Ladung der Speichereinrichtung 44 geöffnet ist.
• Ausführungsbeispiel 14:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei in einer Hydraulikversorgungsleitung L₁ ein Druckübertrager 41 angeordnet ist, wobei der Druckübertrager 41 mit seinem Eingang über eine Hydraulikleitung L₁ mit der Kolben-Zylinder-Einheit 4 in Verbindung ist.
• Ausführungsbeispiel 15:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 14, wobei das Ventil 13 in der die Kolben-Zylinder-Einheit 4 mit dem Eingang des Druckübertragers 41 verbindenden Hydraulikleitung L₁ angeordnet ist.
• Ausführungsbeispiel 16:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 14 oder 15, wobei in der den Ausgang des Druckübertragers 41 mit einer Einrichtung E1, E2, E3, E4 verbindenden Verbindungshydraulikleitung 38 ein Ventil 17, 25, 28, 33 zum wahlweisen Verschließen und Öffnen der Verbindungshydraulikleitung 38 angeordnet ist.
• Ausführungsbeispiel 17:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 12 oder 13, wobei in der die Speichereinrichtung 44 mit einer Einrichtung E1, E2, E3, E4 verbindenden Verbindungshydraulikleitung ein Ventil 17, 25, 28, 33 zum wahlweisen Verschließen und Öffnen der Verbindungshydraulikleitung angeordnet ist.
• Ausführungsbeispiel 18:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei eine erste Hydraulikleitung L₁ den Arbeitsraum der Kolben-Zylinder-Einheit 4 mit einem Eingang eines ersten gesteuerten Ventil 13, insbesondere einem 2/2-Wege-Ventil, verbindet, und dass der Ausgang des Ventils 13 über mindestens eine Hydraulikleitung L₂ mit dem Eingang eines einer Einrichtung E1, E2, E3, E4 vorgeschalteten gesteuerten Ventils 17, 24, 25, 27, 33 in Verbindung ist, wobei entweder ein Druckspeicher 44 mit der Hydraulikleitung L₂ in Verbindung ist oder ein Druckübertrager 41 in der Hydraulikleitung L₂ angeordnet ist.
• Ausführungsbeispiel 19:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 18, wobei die Einrichtungen E1, E2, E3, E4 Kolben-Zylinder-Einheiten 14; 21, 26, 32 aufweisen, deren jeweiliger Arbeitstraum über eine Hydraulikleitung mit dem Ausgang des vorgeschalteten gesteuerten Ventils 17, 25, 28, 33 in Verbindung ist.
• Ausführungsbeispiel 20:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 19, wobei der Arbeitsraum einer Einrichtung E1, E2, E3, E4 mit dem Eingang eines gesteuerten Druckabbauventils 45a, 45b, 45c, 45d in Verbindung ist, dessen Ausgang über eine Hydraulikleitung 39 mit einem Vorratsbehälter 6 für das Hydraulikmedium in Verbindung ist.
• Ausführungsbeispiel 21:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei die Kolben-Zylinder-Einheit 3, 4 im Druckspeicher 44 bei geöffnetem Ventil 13 einen Druck aufbaut, und nach erfolgtem Druckaufbau das Ventil 13 geschlossen ist, wobei die Druckeinregelung in den Einrichtungen mittels der jeweiligen Druckaufbauventile 17, 25, 28, 33 und der jeweiligen Druckabbauventile 24, 45, 45a, 45b wahlweise gleichzeitig, nacheinander, im Sinne eines Multiplexbetriebs, oder zu beliebigen Zeiten, in denen insbesondere kein Druckaufbau im Druckspeicher 44 mittels der Kolben-Zylinder-Einheit 3, 4 erfolgt, erfolgt.
• Ausführungsbeispiel 22:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei mittels der Kolben-Zylinder-Einheit 3, 4 und deren Antrieb Hydraulikmedium in die Einrichtungen E1, E2, E3, E4 oder Druck im Hydraulikmedium für die Einrichtungen E1, E2, E3, E4 nur dann gefördert bzw. auf oder abgebaut wird, sofern die Bremsanlage die Kolben-Zylinder-Einheit 3, 4 nicht benötigt (Prioritätssteuerung).
• Ausführungsbeispiel 23:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei bei Einsatz eines Druckübertragers 41 zwei entgegengesetzt wirkende Rückschlagventile 11, 12 mit einem Arbeitsraum des Druckübertragers 41 in Verbindung sind, wobei über das eine Rückschlagventil 11 Hydraulikmedium mittels des Druckübertragers 41 in die Einrichtungen förderbar ist und mittels des anderen Rückschlagventil 12 Hydraulikmedium mittels des Druckübertragers 41 aus mindestens einer Einrichtung E1, E2, E3, E4 heraus förderbar ist.
• Ausführungsbeispiel 24:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 23, wobei der Druckübertrager 41 eingangsseitig mit der Kolben-Zylinder-Einheit und ausgangsseitig mit den Einrichtungen und einem Vorratsbehälter über zwischengeschaltete gesteuerte Ventile in Verbindung bringbar ist, so dass wahlweise ein Nachfördern von Hydraulikmedium aus dem Vorratsbehälter in die Ausgangsseite des Druckübertragers mittels entsprechender Ansteuerung der Kolben-Zylinder-Einheit möglich ist.
• Ausführungsbeispiel 25:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei in dem Antrieb der Einrichtung E3, E4 eine Medientrennung zwischen Hydraulikmedium der Kolben-Zylinder-Einheit 3, 4 und dem Medium der Einrichtung E3, E4 erfolgt.
• Ausführungsbeispiel 26:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei zumindest einige oder alle Ventile 17, 25, 28, 33, 45a-d, 11, 12, 13 und/oder der Druckspeicher 44 bzw. der Druckübertrager 41 in einem Modul oder Gehäuse, insbesondere zusammen mit den ABS- und/oder ESP-Ventilen des Fahrzeugbremssystems angeordnet sind.
• Ausführungsbeispiel 27:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 26, wobei zusätzlich die Radschaltventile 8, 8a und/oder der Druckgeber 7 mit in dem Modul bzw. Gehäuse angeordnet sind.
• Ausführungsbeispiel 28:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei der Druckaufbau im Druckspeicher 44 während der Zeiten mittels der Kolben-Zylinder-Einheit 4 erfolgt, wo kein Bremsdruckaufbau und/oder Bremsdruckabbau mittels der Kolben-Zylinder-Einheit erfolgt.
• Ausführungsbeispiel 29:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei der im Bremssystem verwendete Druckgeber 7 für die Ermittlung des Druckes in den Hydraulikleitungen L1, L2 und/oder dem Speicher 44 dient.
• Ausführungsbeispiel 30:
  • Druckversorgungseinrichtung nach Ausführungsbeispiel 29, wobei während der Druckermittlung der Kolben 3 der Kolben-Zylinder-Einheit 4 nicht bewegt wird.
• Ausführungsbeispiel 31:
  • Druckversorgungseinrichtung nach einem der vorhergehenden Ausführungsbeispiele, wobei mittels eines, insbesondere im Druckspeicher 44 angeordneten, Druckgebers 7 der Druck in einer der Hydraulikleitungen L₁, L₂ ermittelbar ist, wobei insbesondere die Bewegung des Kolbens der Kolben-Zylinder-Einheit zur statischen Druckmessung kurzzeitig unterbrochen wird.

Further exemplary embodiments of the invention follow:

• Embodiment 1:
  • Pressure supply device for a motor vehicle with at least one piston-cylinder unit 3, 4 for building up hydraulic pressure in at least one hydraulic line 40 , with the piston 3 the piston-cylinder unit 4th is driven by a drive, and the pressure supply device is used to build up and reduce brake pressure in at least one wheel brake, each wheel brake having a wheel switching valve 8th , 8a is assigned and the brake pressure by closing the wheel switching valve assigned to the wheel brake 8th , 8a can be maintained in the wheel brake and with the wheel switching valve open 8th , 8a the pressure in the respective wheel brake can be set or regulated by means of appropriate control of the drive, the pressure supply device with its driven piston-cylinder unit 3 , 4th in addition to the wheel brakes, at least one hydraulically acting and / or driven device E1, E2, E3, E4 of the motor vehicle via a pressure transmitter 41 and / or by means of a pressure accumulator 44 supplied, during the supply of the at least one device E1, E2, E3, E4) via the pressure transmitter or during the charging of the pressure accumulator 44 by means of at least one valve 8th , 8a the connecting line 40a between the piston-cylinder unit 4th and the wheel brakes can be separated or locked.
• Embodiment 2:
  • Pressure supply device according to embodiment 1, wherein the piston-cylinder unit 3 , 4th drives several hydraulically acting and / or driven devices E1, E2, E3, E4 of the motor vehicle simultaneously, individually or in groups and / or supplied with pressurized hydraulic medium and / or increases the hydraulic pressure in devices E1, E2, E3, E4. or dismantle.
• Embodiment 3:
  • Pressure supply device according to embodiment 1 or 2, with the separation of the connection of the hydraulic supply line to the wheel brakes by means of the wheel switching valves 8th , 8a he follows.
• Embodiment 4:
  • Pressure supply device according to embodiment 1 or 2, the connection of the hydraulic supply line to the wheel brakes being separated by means of a controlled 3/2-way valve for the optional connection of the piston-cylinder unit with the wheel brakes or the at least one hydraulic supply line.
• Embodiment 5:
  • Pressure supply device according to embodiment 1, wherein the piston-cylinder unit 3 , 4th with its drive is part of a braking system of the motor vehicle.
• Embodiment 6:
  • Pressure supply device according to one of the preceding exemplary embodiments, the drive being an electric motor, in particular a highly dynamic electric motor.
• Embodiment 7:
  • Pressure supply device according to one of the preceding exemplary embodiments, the device E1 being the drive for the starter of the vehicle.
• Embodiment 8:
  • Pressure supply device according to one of the exemplary embodiments 1 to 6, the device E2 being the drive for the clutch of the vehicle, in particular for automatically controlled clutch actuation.
• Embodiment 9:
  • Pressure supply device according to one of the exemplary embodiments 1 to 6, the device E3 being the pressure generating device for the cleaning fluid of the windshield wiper system or the pressure generating device for the hydraulic medium of the vehicle level control.
• Embodiment 10:
  • Pressure supply device according to one of the preceding exemplary embodiments, the at least one hydraulic supply line L ₁ with the working chamber of the piston-cylinder unit 4th or via a hydraulic line 40 who have favourited the piston-cylinder unit 4th connects to the wheel brakes, or can be connected in particular by means of a valve.
• Embodiment 11:
  • Pressure supply device according to one of the preceding exemplary embodiments, in which the piston-cylinder unit 4th with at least one device E1, E2, E3, E4 connecting hydraulic supply line L ₁ at least one valve 13th is arranged to selectively close or open the hydraulic supply line L ₁ .
• Embodiment 12:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein at least one storage device 44 , in particular a pressure accumulator, for hydraulic medium for at least one device E1, E2, E3, E4 is present, and the storage device 44 is in connection with a hydraulic supply line L ₁ or can be brought into connection therewith by means of a valve
• Embodiment 13:
  • Pressure supply device according to the embodiment 12th , by means of the valve 13th the connection between storage devices 44 and piston-cylinder unit 4th is separable, the valve 13th for charging the storage device 44 is open.
• Embodiment 14:
  • Pressure supply device according to one of the preceding exemplary embodiments, a pressure transmitter in a hydraulic supply line L ₁ 41 is arranged, the pressure transmitter 41 with its input via a hydraulic line L ₁ with the piston-cylinder unit 4th is connected.
• Embodiment 15:
  • Pressure supply device according to embodiment 14, wherein the valve 13th in which the piston-cylinder unit 4th with the input of the pressure transmitter 41 connecting hydraulic line L _{1 is} arranged.
• Embodiment 16:
  • Pressure supply device according to embodiment 14 or 15, in which the output of the pressure transmitter 41 with a device E1, E2, E3, E4 connecting connecting hydraulic line 38 a valve 17th , 25th , 28 , 33 for optionally closing and opening the connecting hydraulic line 38 is arranged.
• Embodiment 17:
  • Pressure supply device according to the embodiment 12th or 13th , in which the storage device 44 with a device E1, E2, E3, E4 connecting connecting hydraulic line a valve 17th , 25th , 28 , 33 is arranged for the optional closing and opening of the connecting hydraulic line.
• Embodiment 18:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein a first hydraulic line L _{1 is} the working space of the piston-cylinder unit 4th with an input of a first controlled valve 13th , in particular a 2/2-way valve, connects, and that the output of the valve 13th via at least one hydraulic line L ₂ to the input of a controlled valve connected upstream of a device E1, E2, E3, E4 17th , 24 , 25th , 27 , 33 is in connection, with either an accumulator 44 with the hydraulic line L _{2 is} in connection or a pressure transmitter 41 is arranged in the hydraulic line L ₂ .
• Embodiment 19:
  • Pressure supply device according to the embodiment 18th , the devices E1, E2, E3, E4 piston-cylinder units 14th ; 21st , 26th , 32 have, their respective working space via a hydraulic line to the output of the upstream controlled valve 17th , 25th , 28 , 33 is connected.
• Embodiment 20:
  • Pressure supply device according to the embodiment 19th , the working space of a device E1, E2, E3, E4 with the input of a controlled pressure reduction valve 45a , 45b , 45c , 45d is connected, the output of which is via a hydraulic line 39 with a storage container 6th for the hydraulic medium is in connection.
• Embodiment 21:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein the piston-cylinder unit 3 , 4th in the accumulator 44 with the valve open 13th builds up a pressure, and after the pressure build-up, the valve 13th is closed, the pressure regulation in the devices by means of the respective pressure build-up valves 17th , 25th , 28 , 33 and the respective pressure relief valves 24 , 45 , 45a , 45b optionally at the same time, one after the other, in the sense of a multiplex operation, or at any time when there is no pressure build-up in the pressure accumulator 44 by means of the piston-cylinder unit 3 , 4th takes place, takes place.
• Embodiment 22:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein by means of the piston-cylinder unit 3 , 4th and whose drive hydraulic medium in the devices E1, E2, E3, E4 or pressure in the hydraulic medium for the devices E1, E2, E3, E4 is only conveyed or built up or reduced if the brake system is the piston-cylinder unit 3 , 4th not required (priority control).
• Embodiment 23:
  • Pressure supply device according to one of the preceding exemplary embodiments, with the use of a pressure transmitter 41 two counter-acting check valves 11 , 12th with a working space of the pressure transmitter 41 are in connection, via which a check valve 11 Hydraulic medium by means of the pressure transmitter 41 can be conveyed into the facilities and by means of the other check valve 12th Hydraulic medium by means of the pressure transmitter 41 can be funded from at least one device E1, E2, E3, E4.
• Embodiment 24:
  • Pressure supply device according to the embodiment 23 , the pressure transmitter 41 Can be brought into connection on the input side with the piston-cylinder unit and on the output side with the devices and a storage container via interconnected controlled valves, so that hydraulic medium can optionally be replenished from the storage container into the output side of the pressure transmitter by means of appropriate control of the piston-cylinder unit is.
• Embodiment 25:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein in the drive of the device E3, E4 a media separation between the hydraulic medium of the piston-cylinder unit 3 , 4th and the medium of the device E3, E4.
• Embodiment 26:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein at least some or all of the valves 17th , 25th , 28 , 33 , 45a-d , 11 , 12th , 13th and / or the pressure accumulator 44 or the pressure transmitter 41 are arranged in a module or housing, in particular together with the ABS and / or ESP valves of the vehicle braking system.
• Embodiment 27:
  • Pressure supply device according to the embodiment 26th , with the addition of the wheel shift valves 8th , 8a and / or the pressure transducer 7th are arranged with in the module or housing.
• Embodiment 28:
  • Pressure supply device according to one of the preceding exemplary embodiments, the pressure build-up in the pressure accumulator 44 during the times by means of the piston-cylinder unit 4th takes place where there is no brake pressure build-up and / or brake pressure reduction by means of the piston-cylinder unit.
• Embodiment 29:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein the pressure transmitter used in the brake system 7th for determining the pressure in the hydraulic lines L1, L2 and / or the accumulator 44 serves.
• Embodiment 30:
  • Pressure supply device according to the embodiment 29 , with the piston during the pressure determination 3 the piston-cylinder unit 4th is not moved.
• Embodiment 31:
  • Pressure supply device according to one of the preceding exemplary embodiments, wherein by means of a, in particular in the pressure accumulator 44 arranged, pressure transducer 7th the pressure in one of the hydraulic lines L ₁ , L ₂ can be determined, in particular the movement of the piston of the piston-cylinder unit being briefly interrupted for static pressure measurement.

List of reference symbols

1

Brake pedal

2

BKV

3

DK piston

4th

Piston-cylinder unit - THZ

5

Pedal travel sensor

6th

Storage container

7th

Pressure transducer

8th

Wheel switching valve also ABS / ESP control valve

8a

Wheel switching valve also ABS / ESP control valve

9

Stepped piston

10

Changeover valve

10a

Pressure line

11

check valve

12

Suction valve

13th

2/2 solenoid valve

14th

piston

15th

Connecting bolt

16

Return spring

17th

2/2 solenoid valve as pressure build-up valve

18th

Bowden cable

19th

Engagement lever

20th

starter

21st

Piston for clutch slave cylinder

22nd

coupling

23

Position indicator

24

2/2 outlet MV as pressure relief valve

25th

2/2 inlet MV as pressure build-up valve

26th

Delivery piston for windscreen washer

27

Pressure supply line

28

2/2 solenoid valve

29

Reservoir with level transmitter

30th

Spray nozzles for windscreen washer

31

Return spring

32

Stepped piston

33

2/2 solenoid valve as pressure build-up valve

34

Reservoir for level regulation

35

2/2-way exhaust valve

36

check valve

37

hydraulic strut

38

Connection line to consumer X

39

Return line

40

Output line

41

Pressure transmitter

42

electrical connection lines to the control unit (line with arrow)

43

Return valve

44

Pressure accumulator

45a-45d

Pressure relief valve

47

Return line to the reservoir

Claims (23)

Pressure supply device for a motor vehicle, comprising: - At least one piston-cylinder unit (4) for building up hydraulic pressure in at least one hydraulic line (40), - A drive for driving a piston (3) of the piston-cylinder unit (4), the pressure supply device serving to build up and reduce brake pressure in at least one wheel brake, wherein the pressure supply device with the piston-cylinder unit (4) in addition to the wheel brakes at least one hydraulically acting and / or driven device (E1, E2, E3, E4) of the motor vehicle via a pressure transmitter (41) and / or by means of a pressure accumulator ( 44), with a connecting line between the pistons during the supply of the at least one device (E1, E2, E3, E4) via the pressure transmitter (41) or during the charging of the pressure accumulator (44) by means of at least one valve (8, 8a) -Cylinder unit (4) and the wheel brakes can be separated or locked. Pressure supply device according to Claim 1 , characterized in that the piston-cylinder unit (4) drives several hydraulically acting and / or driven devices (E1, E2, E3, E4) of the motor vehicle simultaneously, individually or in groups and / or supplies and / or supplies them with pressurized hydraulic medium / or the hydraulic pressure in the devices (E1, E2, E3, E4) builds up or decreases. Pressure supply device according to Claim 1 or 2 , characterized in that the connection of a hydraulic supply line to the wheel brakes is disconnected by means of the wheel switching valves (8, 8a). Pressure supply device according to Claim 1 or 2 , characterized in that the connection of the hydraulic supply line to the wheel brakes is separated by means of a controlled 3/2-way valve for the optional connection of the piston-cylinder unit (4) with the wheel brakes or the at least one hydraulic supply line. Pressure supply device according to Claim 1 , characterized in that the piston-cylinder unit (4) with its drive is part of a braking system of the motor vehicle. Pressure supply device according to one of the preceding claims, characterized in that the drive is an electric motor. Pressure supply device according to one of the preceding claims, characterized in that a device (E1) is the drive for the starter of the vehicle or a device (E2) is the drive for the clutch of the vehicle or a device (E3) is the pressure generating device for the cleaning fluid of the Windshield wiper system or a device (E4) is the pressure generating device for the hydraulic medium of the vehicle level control. Pressure supply device according to one of the preceding claims, characterized in that at least one hydraulic supply line (L1) with the working chamber of the piston-cylinder unit (4) or via a hydraulic line (40) that connects the piston-cylinder unit (4) with the wheel brakes connects, connected or connectable by means of a valve, and / or that in the hydraulic supply line (L1) connecting the piston-cylinder unit (4) with at least one device (E1, E2, E3, E4) connecting at least one valve (13) for optional closing or opening of the hydraulic supply line (L1) is arranged, and / or that a pressure accumulator (44) for hydraulic medium for at least one device (E1, E2, E3, E4) is present, and the pressure accumulator (44) with a hydraulic supply line (L1 ) is in connection or can be brought into connection therewith by means of a valve, the connection between the pressure accumulator (44) and the piston-cylinder unit by means of the valve (13) it (4) is separable, the valve (13) being opened for charging the pressure accumulator (44). Pressure supply device according to one of the preceding claims, characterized in that a pressure transmitter (41) is arranged in one of the hydraulic supply lines (L1), the pressure transmitter (41) having its inlet connected to the piston-cylinder unit (4 ) is connected. Pressure supply device according to Claim 9 , characterized in that a / the valve (13) is arranged in the hydraulic line (40) connecting the piston-cylinder unit (4) to the inlet of the pressure transmitter (41). Pressure supply device according to Claim 9 or 10 , characterized in that in the connecting hydraulic line (38) connecting the output of the pressure transmitter (41) to a device (E1, E2, E3, E4) a valve (17, 25, 28, 33) for the optional closing and opening of the connecting hydraulic line ( 38) is arranged. Pressure supply device according to Claim 8 , characterized in that in the connecting hydraulic line (38) connecting the pressure accumulator (44) to a device (E1, E2, E3, E4) a valve (17, 25, 28, 33) for the optional closing and opening of the connecting hydraulic line (38) is arranged. Pressure supply device according to Claim 1 , characterized in that a first hydraulic line (L1) connects the working space of the piston-cylinder unit (4) with an input of a first controlled valve (13), and that the output of the valve (13) via at least one hydraulic line (L2) is connected to the input of a controlled valve (17, 24, 25, 28, 33) connected upstream of a device (E1, E2, E3, E4), either a pressure accumulator (44) being connected to the hydraulic line (L2) or a pressure transmitter (41) is arranged in the hydraulic line (L2). Pressure supply device according to Claim 13 , characterized in that the devices (E1, E2, E3, E4) have piston-cylinder units (14; 21, 26, 32), the respective working chamber of which is connected to the output of the upstream controlled valve (17, 25, 28, 33) is in connection. Pressure supply device according to Claim 14 , characterized in that the working space of a device (E1, E2, E3, E4) is connected to the input of a controlled pressure reduction valve (45a, 45b, 45c, 45d), the output of which is connected to a storage container (6) via a hydraulic line (39) ) is in connection for the hydraulic medium. Pressure supply device according to one of the preceding claims, characterized in that the piston-cylinder unit (3, 4) in the pressure accumulator (44) builds up a pressure when the valve (13) is open, and after the pressure has built up the valve (13) is closed, with the pressure regulation in the devices by means of respective pressure build-up valves (17, 25, 28, 33) and respective pressure reduction valves (24, 45, 45a, 45b) optionally takes place simultaneously, one after the other, in the sense of a multiplex operation, or at any time. Pressure supply device according to one of the preceding claims, characterized in that by means of the piston-cylinder unit (4) and its drive, hydraulic medium in the devices (E1, E2, E3, E4) or pressure in the hydraulic medium for the devices (E1, E2, E3 , E4) is only promoted or set up or dismantled if the brake system does not require the piston-cylinder unit (4). Pressure supply device according to one of the preceding claims, characterized in that when a pressure transmitter (41) is used, two oppositely acting check valves (11, 12) are connected to a working chamber of the pressure transmitter (41), with hydraulic medium via the one check valve (11) Pressure transmitter (41) can be conveyed into the devices and by means of the other check valve (12) hydraulic medium can be conveyed out of at least one device (E1, E2, E3, E4) by means of the pressure transmitter (41), pressure transmitter (41) on the input side with the piston -Cylinder unit (4) and on the output side with the devices and a storage container (6) can be brought into connection via interconnected controlled valves, so that optionally a subsequent delivery of hydraulic medium from the storage container (6) into the output side of the pressure transmitter (41) by means of appropriate Control of the piston-cylinder unit (4) is possible. Pressure supply device according to one of the preceding claims, characterized in that a media separation between the hydraulic medium of the piston-cylinder unit (4) and the medium of the device (E3, E4) takes place in the drive of a hydraulically acting and driven device (E3, E4). Pressure supply device according to one of the preceding claims, characterized in that at least some or all of the valves (17, 24, 25, 28, 33, 45a-d, 11, 12, 13) and / or the pressure accumulator (44) or the pressure transmitter ( 41) are arranged in a module or housing, namely together with the ABS and / or ESP valves of the vehicle brake system, with the wheel switching valves (8, 8a) and / or the pressure transducer (7) also being arranged in the module or housing are. Pressure supply device according to one of the preceding claims, characterized in that the pressure build-up in the pressure accumulator (44) takes place by means of the piston-cylinder unit (4) during the times when no brake pressure build-up and / or brake pressure reduction by means of the piston-cylinder unit (4) he follows. Pressure supply device according to one of the preceding claims, characterized in that a pressure transducer (7) used in the brake system is used to determine the pressure in the hydraulic lines and / or the pressure accumulator (44), the piston (3) being the piston-cylinder during the pressure determination -Unit (4) is not moved. Pressure supply device according to one of the preceding claims, characterized in that the pressure in one of the hydraulic lines (L1, L2) can be determined by means of a pressure transmitter (7) arranged in particular in the pressure accumulator (44), the movement of the piston (3) of the piston Cylinder unit (4) is briefly interrupted for static pressure measurement.

Images