KR0148483B1 - Hydraulic vehicle brake system with anti-skid apparatus - Google Patents

Abstract

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Description

Hydraulic Motor Vehicle Braking System With Anti Skid Device

1 shows an illustration of a first embodiment of a motor vehicle brake system according to the invention.

2 shows a second embodiment of a motor vehicle brake system according to the invention.

FIG. 3 is a detailed view of the third embodiment starting from the motor vehicle brake system according to FIG. 2. FIG.

4 shows a fourth embodiment of a vehicle brake system according to the invention.

5 shows a fifth embodiment of a vehicle brake system according to the invention.

6 shows a sixth embodiment of a vehicle brake system according to the invention.

7 shows a seventh embodiment of a vehicle brake system according to the invention.

* Explanation of symbols for main parts of the drawings

8: Breakline 9: Anti skid device

12: return pump 17: bypass throttle

19: control unit 28: pump element

30: outlet 37: valve seat

41, 46: opening spring

The present invention relates to a hydraulic motor vehicle system with an anti skid device.

In the motor vehicle brake system according to FIG. 1 of DE-OS 3107963, the valve formed in the brake line from the brake master cylinder is in the form of a one-way valve. This one-way valve is openable in at least one wheel brake direction by the pressure from the master brake cylinder. Pressure-compensating bypass in the form of a line forming a throttle bypasses the one-way valve. This throttling bypass acts to completely reduce any residual brake pressure in the wheel brake cylinder following release of the brake pedal, in accordance with the purpose of the present invention, for rapid emptying of the wheel brake cylinder. It cannot be achieved by the provided non-return valve method. For stability, such check valves are equipped with a closure spring, which hinders the complete embossing of the wheel brake cylinder. The one-way valve mounted to the brake line according to the object of the present invention prevents pressure surge from the brake master cylinder caused during anti-skid operation. Thus, continuous jolts to the driver's feet and movement of the brake pedal are prevented. Since the entire pressure medium in anti skid operation to be retracted from the wheel brake has to be collected in the high pressure accumulator, the accumulator is larger, heavy and expensive than necessary.

This type of motor vehicle brake system, known from DE-OS 2643860, has an exit in communication with a damper chamber and a return connected to the brake master cylinder and the anti skid valve device by means of a throttle means installed downward of the damper chamber. Have a pump. The damper chamber coupled with the throttle damps the vibration generated from the return pump so that it is no longer difficult. However, if not reduced by the wheel brakes, the amount of pressure medium flowing through the throttle causes a very difficult brake pedal stroke. This may irritate the timid driver and undesirably attempt to partially release the brake pedal.

A motor vehicle brake system according to the invention comprises a brake master cylinder, at least one wheel brake and at least one anti skid device inserted between the brake master cylinder and the wheel brake and having at least one anti skid valve device, The anti skid valve device is connected to the master brake cylinder and the wheel brake and also to the inlet of the return pump, a damper chamber and a damper throttle are disposed past the outlet of the return pump and the damper throttle is in communication with the anti skid valve device. In the brake system,

An at least partially closeable valve is installed between the brake master cylinder and the coupling portion of the damper throttle and the anti skid valve device and is controlled during anti skid operation, wherein the damper chamber has an enlarged pressure medium capacity.

The motor vehicle brake system with the features of the invention and its independent claims has the advantage over the motor vehicle brake system of the general type according to DE-OS2643860, in which the reaction effect on the brake master cylinder is reduced at low cost during anti skid operation. The brake pedal is no longer displaced. The suppression of the complete response effect as achieved by the high technical cost in the motor vehicle brake system according to DE-OS 3107963 is not desirable on its own, because the driver is adjusted by the driver by such a brake pedal. This is because the brake pressure must be appropriately recognized by the brake pedal when the brake pressure is too high for at least one vehicle wheel. An additional advantage of the motor vehicle brake system according to the invention is that the amount of pressure medium flows in a throttled manner from the brake master cylinder to the wheel brake in order to return the brake pressure in the wheel brake during anti skid operation.

With suitable features, improvements and additional beneficial improvements to the motor vehicle brake system are possible.

In one embodiment, the controllable valve is in the form of a two port two position electric control valve, which is opened when no current flows through the valve and is coupled with a bypass which acts as a throttle with the valve. This has the advantage that the configuration in a simple manner is possible, for example, depending on the existing solenoid valves and throttles. Moreover, at the start of normal braking operation, the brake force in the wheel brakes rises rapidly, whereas in anti skid operation for full or partial return of the brake pressure the amount of pressure medium is reduced from the brake master cylinder to prevent rapid pressure rise. Flows in a throttle manner. In one embodiment, the valve is in the form of a valve which can be at least partially hydraulically closed against the opening of the opening spring and has a control inlet in communication with the outlet of the return pump. This has the advantage that the valve additionally acts as a throttle controllable by the supply pressure of the return pump. Thus, the reaction effect increases less than the supply pressure of the return pump.

In an additional feature, the valve is in the form of a pressure compensating seat valve with an open spring stressed in an manner such that a return pressure of 30 bar is required to overcome the evi stress. This means that when braking on an icy surface using a braking pressure carefully selected by the driver, any return movement of the brake pedal with a relatively short return movement will result in suppressed throttling in such cases. It has the added advantage of being clearly apparent and recognizable.

In one embodiment, the stiffness of the opening spring is preselected in such a way that the supply pressure of the 60 bar return pump causes complete closure of the valve. This represents an advantageous dimension in the case of low brake pressure and low pedal force which gives the driver a clear indication of early anti skid operation. On the other hand, in the situation of high brake pressure, the reactivation effect on the brake pedal does not significantly increase so that the driver reduces the operation of the brake pedal, and therefore the braking interval is also increased.

In one embodiment, the bypass throttle with the remaining cross section open consists of a hydraulically closeable valve. The integration of the throttle into this hydraulically closeable valve ensures that the remaining cross section remains reliably open, which has the advantage that progressive pressure compensation occurs between the brake master cylinders.

In one embodiment, the bipiece throttle has a cross section substantially up to 0.2 mm 2. This represents the use of the proposed dimensions, which may be possible after only a few attempts to achieve proper adoption for existing requirements. In one embodiment, the opening spring is configured in a prestressed manner in which a return pressure of at least 10 bar is required to overcome its closing force. It also represents the dimensional determination that results from initial reduction in pedal reaction.

In one embodiment, the valve has a second control inlet permanently connected to the brake master cylinder, the valve counteracting the control force from the pressure of the return pump supplied with control force from the pressure of the brake master cylinder to the first control inlet. Are arranged in such a way. This has the advantage that the valve can be opened and closed again to the starting position with high reliability. This is particularly advantageous if the valve opening spring is not actuated. This form also has the advantage that the valve can use a large flow through cross section when the pressure of the brake master cylinder is increased by the driver.

In one embodiment, the pump protection valve is disposed between the outlet of the return pump and the brake master cylinder. This has the advantage that the overload of the return pump can be avoided, for example in the case of some significant clogging of the throttle, which occurs simultaneously due to rubber wear. In an embodiment, said pump protection valve is in the form of a pressure limiting valve. This represents a pump protection valve whose opening pressure is independent of the prevailing pressure of the brake master cylinder. In another embodiment, the pump protection valve is in the form of a non-return valve that can be opened in the direction of the brake master cylinder against spring force. This provides a more cost effective pump protection valve, but additionally has the advantage that the blockage is reliably prevented due to the construction. In an embodiment, the at least partially closed valve is received in a block that can be secured to the anti skid device. This has the advantage that an improvement in the sense of reducing the reactivation of the pedal according to the invention with the wide use of the anti skid device produced is possible in a cost effective manner.

In one embodiment between the damper chamber and the first contact portion of the anti skid valve arrangement, a check valve is arranged which is opened by pressure from a return pump in the direction of the anti skid valve arrangement. This provides a known advantage at the start of the braking operation to prevent the pressure medium from flowing out of the master brake cylinder in the damper.

In one embodiment, the wheel brake relief valve in the form of a return valve and open toward the brake master cylinder is connected to the brake master cylinder at at least one wheel brake. In spite of the aforementioned combination of valves or a combination of throttles and valves, it provides the advantage that the brake force rapidly disappears when the brake pedal is released.

By way of example only, seven specific embodiments of a motor vehicle braking system according to the present invention will be described with reference to the accompanying drawings.

The motor vehicle braking system 2 according to the embodiment of the present invention as shown in FIG. 1 includes a brake pedal 3, a brake force booster 4 disposed on the pedal side, and a brake force booster 4. And a brake master cylinder 5 having brake circuits I and II, wheel brakes 6 and 7 belonging to brake circuit I, brake lines 8 and an anti skid device 9.

Although not shown, the anti skid device 9 may be connected to the brake circuit II in the same manner. For simplicity, this anti-skid device and the wheel brakes associated with it are not shown.

The anti skid device 9 is a joint anti skid valve device 10, a low pressure accumulator 11, a return pump 12, a damper chamber 913, a damper throttle 14, a check for two wheel brakes 6, 7. Wheel rotation sensor 20 of controller 19 as well as valve 15, two-port two-position electrical control valve 16, bypass throttle 17, wheel brake relief valve 18 in the form of a check valve. , 21). The anti-skid valve device 10 is, for example, in the form of a three-port three-position solenoid valve, as shown, from the brake master cylinder 5 to the two-port two-position valve 16 and the brake line 8. Both the first connection portion 22 supplied via the brake pressure, the second connection portion 23 connected to the wheel brakes 6, 7, the low pressure accumulator 11 and the inlet 25 of the return pump 12. It has a third connection portion 24 connected thereto. Instead of these three-port three-position solenoid valves, a specialist may use a combination of more simply designed solenoid valves, for example a two-port two-position solenoid valve. The return pump 12 has an inlet valve 26, an outlet valve 27, and a pump element 28 therebetween, for example, a conventional cylinder, a moving piston, an electric motor (not shown), for example. 29) and an eccentric to be driven. Downstream of the outlet valve 27, the return pump 12 has an outlet 30. The outlet 30 is connected to the damper chamber 13 and to the damper throttle 14. The damper chamber 13 may be in the form of a hollow chamber, the interior of which is a metallic housing, as proposed in DE-OS 2643860. The damper chamber 13 may also be in other forms, for example in the form of a piston accumulator or a thin film accumulator. As seen from the outlet 30 of the return pump 12, the check valve 15 is connected via a damper throttle 14. The check valve 15 is connected to both the first connection portion 22 and the bypass throttle 17 of the anti skid valve device 10. The bypass throttle 17 is in turn connected permanently to the brake master cylinder via the brake line 8 of the brake circuit I. Bypass throttle 17, in the normal state, bypasses around the two-port two-position valve 16, which connects the brake master cylinder 5 to the first inlet 22 of the anti skid valve device 10. Forming, but closed during anti skid operation.

In the basic position of the anti skid valve device 10, the pressure medium flows between the first connection 22 and the second connection 23 and is damped by the brake master cylinder 5 and / or the return pump 12 by the damper throttle. It can be pressed through 14 to reach the wheel brakes 6, 7. The check valve 18 can be inserted between the wheel brakes 6 and 7 and the brake master cylinder 5 to open from the wheel brakes 6 and 7 toward the brake master cylinder 5 by a sufficient pressure gradient. The residual pressure remaining on the wheel brakes 6, 7 depends on the spring 31 force provided to seal off the pressure coming from the brake master cylinder 5.

The control device 19 is used to detect the wheel rotation signal from the wheel rotation sensors 20 and 21 and infer that at least one of the wheel rotation sensors 20 or 21 has exceeded a predetermined slip threshold. It is used to emit a control signal when providing a signal sequence from the control device 19. The control device 19 controls the two-port two-position valve, the anti skid valve device 10 and the electric motor 29.

[Operation of Motor Vehicle Braking System]

When the brake pedal 3 is not actuated, the valves 10 and 16 are in the basic position shown. The brake pedal 3 actuates the brake pressure via the brake line booster 4 and the brake master cylinder 5 via the brake line 8, the two-port two-position valve 16 and the anti-skid valve device 100. The wheel brakes 6 and 7 are reached.If there is sufficient frictional engagement between the wheels connected with the wheel brakes 6 and 7, and the road surface, the anti skid device 9 is not activated.

If, as a result of the progressively strong actuation of the brake pedal 3 or the reduction of the frictional engagement, the sensor signal from the wheel rotation sensors 20, 21 where the control device 19 is in danger of the wheel block. If it is set based on the sequence of the second connector 23 controls the anti skid valve device 10 to the second switch position is connected to the third connector (24). As a result, the amount of pressure medium flows from the wheel brakes 6, 7 to the low pressure accumulator 1, so that the brake pressure in the wheel brakes 6, 7 actually drops. The control device 19 opens and closes the electric motor 29 of the pump, so that the amount of pressure medium flowing from the low pressure accumulator 11 through the inlet 25 and the inlet valve 26 causes the outlet valve 27 and the outlet 30 to flow. Conveyed directly in the direction of the damper throttle 14. This damper throttle 14 exhibits a flow resistance, as is known in the art, and in part a pressure increase occurs leaving the outlet 30 of the return pump 12 and flowing into the damper chamber 13. In addition, the controller 19 switches the two-port two-position valve 16 to the closed position. As a result, the outlet 30 of the return pump 12 is only connected to the brake master cylinder 5 via the bypass throttle 17. On the other hand, however, the outlet 30 is connected to the first inlet 22 of the anti skid valve device. In the second switching position of the anti skid valve device 10 described above, the connection between the first connector 22 and the second connector 23 is interrupted. Thus, since the amount of the pressure medium leaving the outlet of the return pump 12 flows into both the damper chamber 13 and the brake master cylinder 5 in a throttle manner, the brake master cylinder causes the brake pedal 3 to be initially damped in a damper manner. Move in the direction of the position. This occurs against the driver's foot forces. The larger the damper chamber 13, the easier the movement of the brake pedal 3 is.

If the control device 19 recognizes that the risk of lock has been eliminated through the acceleration of rotation of the wheel or wheels, the damper chamber 13 is controlled by controlling the anti skid valve device 10 to return to the default position. The amount of pressure medium from) flows to the wheel brakes 6, 7, where the wheel brakes increase the brake pressure again. In such a case, if the consumption of the contents of the damper chamber 13 occurs, the amount of pressure medium is transferred in a retarded manner from the brake master cylinder 5 through the bypass throttle 17. Flow up to (6, 7). If the control device 19 is set such that the brake slip is likely to increase in an unreasonable manner, the second connection 23 is initially closed with respect to the first connection 22 and the third connection 24. It is also possible to control the anti-skid valve apparatus 10 to a first control position which is to be made or into a second control position already described above as a pressure reducing shock position. In the first case, another increase in brake pressure is reduced to avoid the risk of increasing wheel lock. In the second case, the initial risk of wheel locks is essentially prevented.

The anti skid valve device can be terminated by releasing the brake pedal, provided that the anti skid valve device 10 is in the second control position to block the brake pressure from the wheel brakes 6, 7. In this case, the check valve 18 is opened against the spring 31 force as a result of the initial sufficiently large pressure differential between the wheel brakes 6, 7 and the brake master cylinder 5.

When the control device 19 terminates the anti skid operation, the anti skid valve device 10 and the two port two position valve 16 return to the basic position shown. As a result, the system is in the normal brake operating state, which initially described the brake operation.

As shown in FIG. 2, the second embodiment of the motor vehicle brake system 2a according to the present invention is a two-port two-position hydraulic control valve 16a having a brake line 8 and an anti skid valve device 10. As shown in FIG. It is different from the embodiment shown in FIG. The two-port two-position hydraulic control valve 16a may have a control inlet 32 as is known in the art. This control inlet 32 is connected to the damper chamber 13 by a control line 33. As mentioned, if the damper chamber 13 is not shown but the interior of the housing block is in the form of a hollow seal, and the two-port two-position valve 16a is coupled to the housing block, the control line 33 is an example. For example, it may be formed from any connecting bore between the two-port two-position valve 16a and the damper chamber 13. Of course, the control line 33 can be led to another arrangement between the outlet valve 27 of the return pump 12 and the damper throttle 14. In all of the above cases, the control pressure required to close the two-port two-position valve 16a is controlled by the flow-hrough resistance of the damper throttle 14, so that the return pump is capable of sufficient pressure rise. And thus generates a control pressure.

The two-port two-position valve 16a to the closed position by the pressure medium from the low pressure accumulator 11 used to switch on the return pump 28 and increase the pressure past the outlet valve 27. By hydraulic control, the control device 19a can have a simpler form than the control device 19 of the first embodiment. A simple variant is used for the simultaneous switch-on of the two-port two-position valve 16 and the electric motor 29 of the first embodiment using a common output stage not shown in the control signal. In this case, it means that the cable connection is omitted.

With respect to normal brake operation, the second embodiment is operated in the same manner as the first embodiment. In anti skid operation, the only difference is the already known difference that the two-port two-position valve 16a provided for the actuation of the brake pedal 3 is continuously hydraulically controlled by the return pump 12. When the two-port two-position valve 16a is in turn closed, the bypass throttle 17 is anti-lock with the outlet 30 of the return pump 12 and the brake master cylinder 5 and / or the brake master cylinder 5. A throttled amount of pressure medium is provided to flow between the skid valve device 10.

The third embodiment of the present invention according to FIG. 3 uses a proportional valve 16b instead of the valve 16a in the form of an on / off valve. Different. This is not only a housing 34 having a control cylinder 35 and a valve chamber 36 having a valve seat 37 but also a control piston 38 movable in the control cylinder 35, an actuating rod 39 connected to the control piston. , A closing member 40 and an opening spring 41. The closing member 40 is disposed inside the valve chamber 36 and guided toward the valve seat 37. The control piston 38 is fixedly connected to the closing member 40 via the actuating rod 39. The opening spring 41 is incorporated into the valve chamber 36 in a manner actuated by the actuation rod 39, which presses the closing member 40 away from the valve seat 37 into the open position and thereby controls the piston 38. Determines the default location of

The valve chamber 36 is connected to the brake master cylinder 5 by a first connecting portion 42. The valve 16b is connected to the anti skid valve device 10 and the check valve 15 via a second connecting portion 43 in communication with the valve seat 37. For this reason, the return pump 12 can pressurize the pressure medium to the valve seat 37 via the damper throttle 14. The control cylinder 35 is also connected to the outlet 30 of the return pump 12 via a third connection 44.

Advantageously, the diameter of the actuating rod 39 is selected to be substantially the same size as the diameter of the valve seat 37 at the position where the closing member 40 can contact. As a result, the pressure is compensated for the first connection 42 when the valve 16b is in the substantially closed position.

Advantageously, the opening spring 41 is sized in such a way as to have an initial stress upon insertion into the valve chamber 36 and the control piston 38 must be operated in the region of 30 bar by pressure to overcome the initial stress. . The closing member 40 is moved in the direction of the valve seat when the return pump 12 is connected and a sufficient pressure medium is available for the low pressure accumulator 11. In order to close the valve 16b completely because the opening spring 41 is pressurized above its initial stress, a pressure greater than the pressure mentioned above is required for the control cylinder 35. By appropriate selection of the rigidity of the opening spring 41, the valve 16b is completely closed when the pressure generated from the return pump 12 actually rises in the control cylinder 35 against a pressure level of 60 bar. It will therefore be appreciated that as the initiation of each anti skid operation increases the configuration of the flow through cross section between the valve seat 37 and the closing member 40 as the return pressure is increased.

In the situation of low return pressure, which can also apply only a slight force on the brake pedal 3, the valve 16b is substantially fully open. Since the low return pressure is generally a result of the low brake pressure, the brake pedal movement is generally short. However, if the high brake pressure is reduced it also leads to high return pressure and involves a significant amount of pressure medium. This amount then flows into the master brake cylinder 5 in a larger throttle manner as a result of the throttle effect controlled by the throttle effect result in the valve 16b. Thus, inactive movement of the brake pedal 3 in the direction of the starting position is prevented. However, the damper chamber 13 must then additionally accommodate the amount of pressure medium that is prevented from flowing in the brake master cylinder. As a result the pressure in the damper chamber 13 continues to rise and the higher driving pressure is effective in the damper throttle 14 and therefore the brake as a result of continuous closing of the valve 16 which persists for this reason. Inactive movement of the pedal 3 is continuously prevented.

In the embodiment according to FIG. 3, the bypass throttle 17 of the second embodiment according to FIG. 2 can be selected and used in a similar manner. As a result, there is a residual cross section between the return pump 12 and the master brake cylinder 5 which can be optimized by testing. On the other hand, the valve seat 37 can be set up in a manner that does not require the separation device of the bypass throttle 17.

This embodiment is disclosed with respect to the anti skid valve device 10 and the wheel brakes 6, 7 connected thereto. The anti skid devices 9 and 9a therefore describe the form of a single passage brake pressure regulator, respectively. This single channel brake pressure regulator is used to joint the pressure regulation in the rear gnlf brake. Of course, if the brake circuit II does not become a single through type, two anti skid valve arrangements 10 can be provided, with the result that it is clear that two regulating passages designed according to the knowledge of the prior art are provided in one brake circuit. As a result, for example, the left and right wheel brakes of the front wheel can be supplied with a suitable brake pressure, respectively. Furthermore, for example, one regulating passage can be connected to the front wheel brake and the other regulating passage is diagonal. It can be connected to the rear brake which is placed opposite. All embodiments of the brake circuit can be implemented using the teachings of the present invention, in which an economical motor vehicle braking system equipped to prevent the risk of wheel blocks with low technical cost is advantageous to use and possibly the brake pedal. It can be formed in such a way as to protect the vehicle user from anxiety caused by the considerably large deflection of (3).

When the damper chamber 13 continues to increase, the check valve 15 device is even more important. Primarily the check valve prevents the empty damper chamber 13 from filling the pressure medium from the brake master cylinder 5 when the brake pedal 3 is operated in a known manner. This leads to undesirable long movement of the brake pedal 3.

The fourth embodiment of the motor vehicle brake system 2b according to FIG. 4 comprises only a brake pedal 3, a brake force booster 4, a brake master cylinder 5, and at least two wheel brakes 6, 7. It also has a brake line 8 and an anti skid device 9b for the brake circuit I.

The anti skid device 9b differs from the anti skid device 9 described above in that the anti skid valve device 10a comprises two two port two position solenoid valves 10b, 10c as described above. In such a case, the two port two position solenoid valve 10b is normally open and the two port two position solenoid valve 10b is normally closed. The first connecting portion 22a is associated with the anti skid valve device 10a similarly to the embodiment described above. The connection is associated with a two port two position valve 16b. The connection is connected similarly to the two port two position valve 16b. The second connecting portion 23a of the solenoid valve device 10a is connected to the wheel brake 6 in this embodiment. The third connecting portion 24a is again connected to the low pressure accumulator 11 and the inlet 25 of the return pump 12. Damper chamber 13 of suitable dimensions is also connected to the outlet of the return pump. Downstream of the damper chamber 12, 13 of the appropriate dimensions there is a damper throttle 14 to which the check valve 15 of the first embodiment is connected, which in turn is the first of the anti skid valve device 10a. It is connected to the narrow part 22a. The check valve 15 is similar to the embodiment described above as well as additionally connected to a two port two position valve 16b. However, the two port two position valve 16b is also connected to the other by the brake line 8 of the brake circuit I with respect to the brake master cylinder 5. Between the wheel brake 6 and the brake master cylinder 5 a wheel brake relief valve 18 with the spring 31 described above is located.

In this embodiment, the bypass throttle 17a is integrated with the two port two position valve 16a. The two port two position valve 16b has a control inlet 32a, which communicates with the damper throttle 14 via the control line 33a and in this way the outlet of the return pump 12. The control pressure is received from 30. During the anti skid operation, the return pump 12 is connected as in the above-described embodiment so that control pressure passes to the control inlet 32a of the two port two position valve 16b, the changeover of which is the bypass throttle 17a. From a flow through cross section that is not throttled relative to the end face of The bypass throttle 17a may have, for example, a throttle bore having a diameter of 0.3 to 0.5 mm.

According to the respective sizes of the two wheel brakes 6, 7, that is, the wheel brakes are supplied from the brake master cylinder 5 to the pressure medium via the two-port two-position valve 16b and the selected of the return pump 12. Depending on the supply capacity, each application or optimization of such bypass throttle 17a may be performed by a test that is easily performed.

As mentioned, the second wheel brake 7 is associated with a two port two position valve 16b. In this embodiment, the second wheel brake 7 has its own anti skid valve device 10a. For this reason, the wheel brake 7 is associated with its own wheel brake relief valve 18. The above embodiment no longer needs to be described since part of the prior art relates to a brake circuit I valve arrangement for independent brake pressure regulation in two wheel brakes.

The brake circuit II of this embodiment also includes wheel brakes 6a and 7a. In a similar manner, these wheel brakes 6a, 7a are, if appropriate, damper chambers with their own anti skid valve device 10a and similar with its own return pump 12, damper throttle 14, 13) and its own two port two position valve 16b with an integrated bypass throttle 17a.

The operation of the bypass throttle 17a corresponds to the operation of the bypass throttle 17 of the earlier embodiment during anti skid operation.

The anti skid device 9b must be economical and is in the form of a basic embodiment of distributing comfort achieved using the present invention. The two port two position valve 16b can be accommodated in a special block 45 which can be coupled to the basic embodiment of the anti skid device 9a by, for example, a screw. The result is a modular type construction that can fulfill different execution requirements.

The fifth embodiment of the motor vehicle brake system 2c according to FIG. 5 also includes a brake pedal 3, a brake master cylinder 5 and brake circuits I and II. The brake hero I comprises two wheel brakes 6, 7 as an embodiment according to FIG. 2, the wheel brake pressure of which can be changed in common by the anti skid valve device 10. Again, the low pressure emulator 11 and the return pump 12 are connected to the anti skid valve device 10. Also on the outlet side of the return pump 12 are damper chambers 13 and damper throttles 14 of suitable dimensions. The damper throttle 14 is again connected to both sides of the anti skid valve device 10 and the two-port two-position valve 16c via a check valve 15.

In contrast to the embodiment according to FIG. 4, the two port two position valve 16c has a first control inlet 32b and a second inlet 32c. The control inlet 32b is connected to the damper chamber 13 via a control line 33 as in the embodiment according to FIG. 2. The second control inlet 32c communicates with the brake line 8 and with a portion of the brake master cylinder 5. The bypass throttle 17a is integrated as described in the embodiment according to FIG.

The opening spring 46 associated with the two-port two-position valve 16c is, for example, from a normal position that is not throttled when the 10 bar control pressure supplied to the control inlet 32b is free of pressure at the control inlet 32c. It is only dimensioned enough for a switch-over of the two port two position, valve 16c, into the throttle position that allows the bypass throttle 17a to flow through the amount of pressure medium.

Again, as soon as the return pump 12 is connected to the method described above for performing anti skid operation, the control pressure is returned by the return pump 12 via the damper chamber 13 and the control line 33 to the two port 2. Can be supplied to the position valve 16c. Since the pressure generated in the brake master cylinder 5 is acted through the second control inlet 32c with respect to the prevailing pressure of the first control inlet 32b, when the pressure in the brake master cylinder 5 is sufficiently high, the two ports The two position valve 16c may be connected again to the open basic position. This has the advantage that the driver can arbitrarily provide a large brake pressure to the wheel brakes 6, 7 during the anti skid operation process by increasing the pressure in the brake master cylinder 5. This is the case when the driver first drives his car on a smooth surface. On skids where anti skid action is initiated and finally with a large skid resistance characteristic, the large skid resistance characteristic is substantially high brake deceleration. Allow. As already mentioned herein, the two-port two-position valve 16c having such a form has the advantage that it can still increase the pressure in the wheel brakes 6, 7 even if the opening spring 46 is weakened. Has

Of course, a two port two position valve 16c with two control inlets 32b, 32c can be similarly used in the embodiments described below and in the embodiments described above.

In another particular form of the above-described embodiment in the FIG. 5, a pump protection valve is provided between the return pump 12 and the brake master cylinder 5. In FIG. 5, the pump protection valve is shown as a pressure limiting valve 47 as a standard symbol. The pressure control valve 47 opens when a preselected pressure enters its control inlet 48. The pressure of the return pump 12 acts as a control pressure. A pump protection valve having such a form is technically complex in itself, but may have the advantage that the pressure limitation is carried out irrespective of the pressure always present in the brake master cylinder 5.

In the sixth embodiment of the motor vehicle brake system 2d according to FIG. 6, it is in the form of a pump protection valve valve 49, which valve may comprise a spring 50. As a result of the same shape as the check valve 49, the pump protection valve opens when a predetermined pressure difference is reached between the outlet 30 of the return pump 12 and the brake master cylinder 5. The pressure difference can be determined by the design of the spring 50. Since the check valve 49 is very economical and reliable, the return pump 12 can be protected from overload in an economical way.

In spite of the embodiment, if the bypass throttle is somewhat clogged by dust, the overload of the return pump 12 will occur, as a result of which the return pressure and return pump 12 present in the brake master cylinder 5 at any time. There is a greater pressure difference between the return pressures supplied.

The seventh embodiment of the motor vehicle brake system 2e according to FIG. 7 is another of the embodiment according to FIG. 2 through the above pump protection valve arrangement. In the example according to FIG. 7, the pump protection valve is shown in the form of a pressure limiting valve 47. However, as described above, a check valve 49 may be inserted instead of such a pressure limiting valve 47 if necessary. Thus, the overload of the return pump 12 can be avoided in that the amount of the pressure medium is switched from the outlet 30 into the brake master cylinder 5 which bypasses any of the bypass throttles described above.

Claims (15)

At least between the brake master cylinder 5 and at least one wheel brake 6, 7 and the brake cylinder 5 and the wheel brakes 6, 7 and having at least one anti skid valve device 10. One anti skid device (9, 9a, 9b) is provided, which is connected to the brake master cylinder (5) and the wheel brakes (6, 7) and has an inlet (25) of the return pump (12, 28). And a damper chamber 13 and a damper throttle 14 are disposed past the outlets 30 of the return pumps 12 and 28, and the damper throttle 14 communicates with the anti-skid valve device 10. In a hydraulic motor vehicle brake system with an anti skid device, the partially closeable valves 16, 16a, 16b, 16c are provided with a brake master cylinder 5 and a damper throttle 14 and an anti skid valve device 10. Is installed between the joints of the control and controls during anti skid operation It said, the damper chamber (13) is a motor vehicle brake system, characterized in that it has an enlarged capacity of the pressure medium. The control valve (16) according to claim 1, wherein the control valve (16) is in the form of a two-port two-position electric control valve, which opens when no current flows through the valve and operates as a throttle with the valve; Motor vehicle brake system, characterized in that related. 2. The valve (16) of claim 1, wherein the valves (16a, 16b, 16c) are in the form of hydraulic valves that are at least partially closeable against the force of the opening springs (41, 46) and the outlets (30) of the return pumps (12, 28). And a control inlet (32, 32a, 32b) in communication with the motor vehicle brake system. 4. The motor according to claim 3, wherein the valve (16b) is in the form of a pressure-compensated seat valve with an open spring (41) prestressed in such a way that a return pressure of 30 bar is required to overcome the evi stress. Vehicle brake system. 5. The motor vehicle brake system according to claim 4, wherein the rigidity of the opening spring is preselected in such a way that the supply pressure of the 60 bar return pumps 12, 28 causes a complete closure of the valve 16b. . 6. The motor vehicle brake system according to any one of claims 3 to 5, wherein the bypass throttle (17a), which leaves the residual cross section open, is formed by a hydraulically closeable valve (16b). 7. The motor vehicle brake system according to claim 6, wherein the bypass throttle (17a) has a cross section up to 0.2 mm2. 4. The motor vehicle brake system of claim 3, wherein the opening spring is configured to be prestressed in a manner that requires a return pressure of 10 bar to overcome its closing force. 8. The valve (16c) according to claim 3 or 7, wherein the valve (16c) has a second control inlet (32c) permanently connected to the brake master cylinder (5), the valve (16c) being the pressure of the brake master cylinder (5). Motor vehicle brake system, characterized in that it is arranged in a manner that acts on the control force from the pressure of the return pump (12,28) supplied to the first control inlet (32b). 2. Motor vehicle brake system according to claim 1, characterized in that the pump protection valve (47, 49) is installed between the outlet (30) of the return pump (12, 28) and the brake master cylinder (5). 11. Motor vehicle brake system according to claim 10, characterized in that the pump protection valve (47) is in the form of a pressure limiting valve. 11. Motor vehicle brake system according to claim 10, characterized in that the pump protection valve (49) is in the form of a check valve openable in the direction of the brake master cylinder (5) against spring force. 2. Motor vehicle brake system according to claim 1, characterized in that the partially closeable valve (16, 16a, 16b, 16c) is housed in a block fixed to the anti skid device. The check according to claim 1, wherein the damper chamber (13) and the first connection portion (22) of the anti skid valve device (10) are openable by pressure from the return pumps (12, 28) in the direction of the artisl valve device. Motor vehicle brake system, characterized in that the valve (15) is arranged. 2. The wheel brake relief valve (18) according to claim 1, wherein the wheel brake relief valve (18) in the form of a check valve openable towards the brake master cylinder (5) engages at least one wheel brake (6, 7) with the brake master cylinder (5). Motor vehicle brake system, characterized in that.