JPS60261760A - Brake gear for automobile with antiskid device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a motor vehicle brake system with an anti-skid device, comprising: a pressure source; a brake pressure control valve operated via a pedal and a distance simulator;
and a mask cylinder connected to the brake circuit, the mask cylinder having a main piston, a secondary chamber, an emergency brake protrusion, and a secondary chamber. Further, the above-mentioned and subsequent chambers are connected to the brake pressure control valve via a switching valve, and are disconnected from the brake pressure control valve and connected to the return container during anti-skid, and are further configured to Sometimes it is of the type in which the main piston is moved via the emergency brake protrusion by means of a pedal.

2. Prior Art A motor vehicle brake system with an anti-skid device of the type described above is disclosed in German Patent Application No. 25312.
No. 64, it is known from the specification No. 1. In such known devices, the distance simulator and the brake pressure control valve are housed in the emergency brake piston, and in addition there is an emergency brake ram that projects into the next chamber and is defined for the movement of the main piston. is fixed to the emergency brake piston. A high degree of driving safety can be achieved with such an automobile brake system.

Furthermore, in the known motor vehicle brake system from DE 31 51 292 A1, the distance simulator and the brake pressure control valve can be arranged close to the emergency brake two-stroke and the emergency brake for the main piston The ram and the ram for the emergency brake piston can be combined into one configuration.

In the case of the first-mentioned known automobile braking device,
The disadvantageously high slippage of the wheels controlled by the closed brake circuit is reduced by the pressure drop in the primary chamber of the mask cylinder. The pressure drop is effected by controlling a switching valve which supplies pressure to the secondary chamber from the brake pressure control valve, so that the main piston is moved in the direction of the emergency brake ram. This causes the brake pressure in the secondary chamber to drop. During such a pressure drop, if the pedal is further depressed so that full braking is introduced, for example in an emergency, the emergency brake stone is moved and then the main piston is
- Collision with the emergency brake protrusion that moves further inside the next room. This results in the disadvantage that the stroke of the main piston is limited and therefore it is not possible to achieve a sufficient brake pressure drop, especially if the road grip varies considerably.

It is possible to increase the exit distance between the emergency brake ram and the main piston structurally, but this results in a significantly longer distance in the event of a failure of the pressure source. In this case, unnecessary stepping distance is inconvenient.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automobile brake system of the type mentioned above, which eliminates the above-mentioned drawbacks and is capable of producing sufficient braking in an emergency, for example, even if the slipperiness of the road surface varies significantly. It is to provide.

Means for Solving the Problem The measures taken to solve the aforementioned problem are such that the brake circuit, which is always connected to the braking device, has a pressure accumulator, which pressure accumulator is connected at least as long as there is a risk of locking. The only thing to do is to close the brakes so that they are depressurized.

If there is a risk of locking, a partial amount of the pressure medium present in the closed brake circuit flows into the pressure accumulator. At the end of braking, the pressure accumulator returns a partial quantity into the closed braking circuit.

ADVANTAGES OF THE INVENTION The advantage obtained by the invention is that the main piston does not approach the emergency brake ram during the pressure drop required to reduce the main piston return zero and wheel speed. The only opening with a closed brake circuit is the adjustment hole of the mask cylinder, which is connected during braking. The motor vehicle brake system according to the invention therefore has high driving safety.

Embodiment The accumulator filling valve has a hydraulic control inlet and is configured as a hydraulically controlled two-point, two-position valve, and the hydraulic control inlet is connected directly to a pressure source. Being connected is advantageous and inexpensive. Furthermore, the embodiment according to claim 6 provides a high braking safety in the event of a failure of the pressure source during normal braking. Furthermore, the embodiment according to claim 4 provides an inexpensive control for the switching valve. With the embodiment according to claim 5, the brake pressure decreases extremely quickly during anti-skid.

Embodiment 1 A first embodiment of the automobile brake system 2 shown in FIG. 7
, pedal lever 8, pedal 9, cylinder 10, emergency brake piston 11, plunger 12, mask cylinder 1
3. Main piston 14, main piston return spring 15, emergency brake protrusion 16, return container 17, first anti-skid valve 18, switching valve 19, second separate anti-skid valve 2
0.2LI pressure vessel 22, pressure accumulator filling valve 23 and check valve 2
It has 4. mask cylinder 13, switching valve 19,
Second separate anti-skid valve 20.21 and accumulator 22
belongs to the closed brake circuit ■. The emergency brake stone 11 and the first anti-skid valve 18 belong to the open brake circuit (2).

A conduit 25 leads from the pressure source 3 to a check valve 26, which opens towards the brake pressure control valve 4 and is fixed to it, for example. The brake pressure control valve 4 has a control cylinder 27 in which a control piston 28 springs 29 in a known manner.
It is possible to slide against the A protruding rod 30 is placed on the opposite side of the spring 29.
is located. The bar 30 is arranged longitudinally movably in a spring guide tube 31 which projects into the control cylinder 27 . A spring guide tube is fixed to the lateral main member 6. A distance simulator 5 is arranged between this main lateral member 6 and the protrusion bar 30, and this distance simulator is formed in the shape of a compression spring 32.

The sealing ring 33 prevents losses of pressure medium between the spring guide tube 31 and the control cylinder 27. Horizontal main member 6
is connected to a pedal lever 8 via a pedal lug 7, so that the pedal 9 causes the control piston 28 of the distance simulator 5 to be moved against the spring 29 via the compression spring 32.

A passage 34 leads from the control cylinder 27 into the cylinder 10 . The emergency brake stone 11 is slidable within the cylinder 10 and is sealed by a sealing ring 35, so that there is no loss of pressure medium. cylinder 1
0 is arranged parallel to the control cylinder 27.

The syringer 12 is oriented in the same direction as the emergency brake piston 11 and in its extension, and furthermore the lateral main member 6
Fixed. Such alignment of the lateral main members 6
This is the starting position created by spring 36. A thin emergency brake protrusion rod 16 is attached to the extension of the plunger 12 in the same direction.

An emergency brake protrusion 16 passes through the emergency brake piston 11 and is sealed relative to the emergency brake piston by a sealing ring 37. A mask cylinder 13 is arranged in an extension of the cylinder 10 and is separated therefrom by a wall 38 .

An emergency brake bar 16 passes through said wall 38 and is sealed relative to this wall by a sealing ring 39. The master cylinder 1 cylinder 13 has an adjustment hole 40.
It is connected to the return container 17 via 41.

The brake circuit ■ is connected to the cylinder 10 and has connecting lines 42, 43, which are arranged starting from the cylinder 10 behind the anti-skid valve 18 and for example at the rear axle. It ends with a wheel brake cylinder (not shown) that is assigned to.

The switching valve 19 is designed as an electromagnetically controlled filter port two-position valve and connects the brake circuit (2) with the combustion chamber 44 in its base position. -The firebox 44 is on the wall 3
8 and the main piston 14. On the opposite side of the main piston 14 the mask cylinder 13 surrounds a secondary chamber 45 which receives the main piston return spring 15. The brake circuit {circle around (2)} has connecting lines 46,47 connected to the secondary chamber 45 and downstream of the anti-skid valve 20,21, these connecting lines
For example, there are wheel players (not shown) attached to the front axle. 1 The pressure accumulator 22 is, for example, in a known manner with a cylinder 48;
It consists of a piston 49 that is slidable within this cylinder and a spring 50 that loads the piston 49. The accumulator light valve 23 is designed as a two-point, two-position valve and can be hydraulically controlled and has a hydraulic control valve 51 for this purpose. The spring 52 switches the pressure accumulation type light valve 23 to the locking position. When a sufficiently large hydraulic pressure is introduced into the hydraulic control valve 51, the pressure accumulator type light valve 23 connects the brake circuit I to the pressure accumulator 22. The reversal valve 24 is arranged as a bypass on the pressure accumulator valve 23 and is opened starting from the pressure accumulator 22 in the direction of the brake circuit (2). A hydraulic control port 51 is connected to the pressure source 3 via a line 53 .

The automobile brake system operates as follows.

At the start of operation of a motor vehicle in which the motor vehicle brake system 2 is installed, the pressure source 3 of the motor vehicle brake system 2 is connected. Due to the pressure generated in the pressure source 3, the pressure is passed through the conduit 53 to the hydraulic control valve 5 of the accumulator type light valve 23.
1 to switch this pressure accumulation type light valve to its passing position. When the pedal 9 is operated, the distance simulator 5
moves the control stone 28 by its spring 32;
The pressure that builds up in the conduit 25 thus reaches the passage 34 and the cylinder 10 partially or at full height, depending on the position of the pedal. If the road surface beneath the vehicle has sufficient dip properties for the respective controlled pressure, the pressure generated in the cylinder 10 can be applied by the brake circuit
The anti-skid valve 18 and the connecting lines 42, 43 of the brake circuit (1) in the basic position also act in the wheel brake cylinders. As long as there is no risk of rocking,
The switching valve 19 is in the basic position shown and thereby connects the brake circuit (1) with the first firebox 44. As a result, the main piston 14 is loaded and forced to slide against the main piston return spring 15. In this case adjustment hole 40
, and thus eventually a brake pressure is created in the secondary chamber 45.

This brake pressure is transmitted into the brake circuit I and by means of the antiskid valve 20.21 into the connecting line 46.47 and finally to the wheel brake cylinder, not shown. Since the pressure accumulating type light valve 23 controlled to the passing position applies brake pressure against the piston 49, the pressure in the brake circuit I is increased. Such brake pressure causes piston 49 to move against spring 50. In this case, the pressure accumulator 22 receives a volume corresponding to the travel distance of the piston 49 and the cross-section of the piston. As a result,
After closing the adjustment bore 40, the main piston 14 is returned by a distance which is limited by the capacity reception of the wheel brake cylinders and which is additionally limited to the said capacity absorbed by the pressure accumulator. In short, it is easy to see that the main piston 14 has to be returned a longer stroke if the pressure accumulator 22 is insufficient in order to produce a completely defined brake pressure. As a result of this, there is a spacing 54 between the emergency brake ram 16, which is also moved by the pedal 9, and the main piston 14, which causes the brake control valve to Control pressure without bumping. When the pedal 9 is released, the main piston is returned to the starting position shown and the cover spring 5
0 force causes the pressure accumulator 22 to close to the pressure accumulation type light valve 23 and/or
or the secondary chamber 45 by the check valve 24 and the brake circuit ■
Pressure is released inward.

If the pressure source 3 fails while the vehicle is running, the spring 52 moves the pressure accumulation type light valve 23 to a predetermined locking position. When braking is now introduced, the main piston 1 is activated by the pedal 9 via the pedal lever 8, the pedal ram 7 and the emergency brake ram 16.
4 is moved for brake pressure build-up. As already mentioned, since the pressure accumulation type light valve 23 is closed,
In this case, the main piston 140 stroke corresponds to the main piston stroke in a conventional type of brake system.

If one of the wheels belonging to the closed brake circuit I has a tendency to lock, that one of the antiskid valves 20, 21 whose associated wheel is not in danger of locking is closed.

At the same time, the switching valve 19 is controlled to the second position. In this position, - the firebox 44 is disconnected from the opening brake circuit (2) and - the firebox 44 is connected to the return container 17. However, the anti-skid valve 20 or 21 and the switching valve 1
Such switching at 9 takes place only if the pressure monitoring device 55 housed in the pressure source 3 indicates a sufficiently high pressure.

By switching the switching valve 19 , the pressure in the firebox 44 is reduced and the main piston 14 is thereby moved in the direction of the emergency brake ram 16 . Therefore, the brake pressure also drops in the secondary chamber 45, and the anti-skid valve 20.2
The pressure in the wheel brake cylinder is also reduced by the one of the valves belonging to the wheel at risk of locking. As already mentioned, in the case of a normally operating pressure source, the pressure accumulator 22 absorbs the amount of pressure medium present in the brake circuit I.

Correspondingly, if the spacing 54 is greater than the spacing in a brake system without an accumulator 22, the main piston 1
4 collides with the emergency brake protrusion 16, the pedal 9
is avoided even if the emergency brake protrusion 16 travels relatively large distances in the direction of the secondary chamber 45 by being swiveled power-driven from its rest position. The large distance of the emergency brake protrusion 16 occurs particularly when braking is performed dynamically on a grippy road surface. The capacity of the pressure accumulator 22 must be determined so that even in the case of the above-mentioned relatively large travel distances for moving the emergency brake protrusion 16, there is a sufficient pressure drop to accelerate again the wheels at risk of locking. A return stroke distance is designed to be available for the main piston 14. In this case, when such a wheel reaches a sufficiently high rotational speed, the switching valve 19 is controlled back into its starting position.

As a result, the pressure is again led into the first fire chamber 44 from the brake circuit I which is opened, and a high braking force is supplied to the brake circuit I through the anti-skid valve 20 or 21 which is still closed. do. When no more risk of locking is detected, the other anti-skid valve 21 or 20 is opened again. The control of the brake circuit ni antiskid valve 18 takes place in a known manner.

When the pressure source 3 fails, the pedal 9 and the plunger 12
is sufficiently rotated against the emergency brake piston 11,
Therefore, emergency brake pressure is also created in the brake circuit (2).

A second embodiment of the automobile brake system 2a according to FIG.
This embodiment differs from the first embodiment already described in the following points. A conduit 53a thus originates from the pressure source 3 and leads to an electromagnetically controlled two-point/two-position valve which serves as a pre-control valve 56. The hydraulic control inlet of the pressure accumulator type light valve 23 is connected to the pre-control valve 56 via a conduit 53b.

The pressure accumulator of the first embodiment can be connected to this pressure accumulation type light valve 23. The illustrated pressure accumulator 2.2a has a different construction from the pressure accumulator of the first embodiment, with a cylinder 48a, a piston 49a, a spring 50a and an additional adjusting piston 57.
and an adjustment cylinder 58 surrounding it.

The adjusting cylinder 58 has a larger diameter than the cylinder 48a, and the adjusting stone 57 is connected to the two stones 49a. The adjusting cylinder 58 has two connections 59.
60.

Connecting portion 59 is connected to conduit 53b via conduit 61. A conduit 62 leads from the connection 60 to a hydraulic control port 63 of the hydraulically controllable switching valve 19a. In another embodiment, the switching valve 19a is designed as a three-point/two-position valve, and during normal control, the brake pressure is guided from the brake circuit (2) into the first fire chamber 44, and during anti-skid, one is conducted. It serves to connect the firebox 44 with the return channel 17. If there is a risk of locking of the wheels assigned to the closing brake circuit (2), the front control valve 56 is electromagnetically activated into the passing position. The pressure source 3 is thereby connected via lines 53a and 53b to the hydraulic control inlet 51 of the switching valve 19, so that the pressure in the brake circuit 2 loads the piston 48a. At the same time, the adjusting stone 57 is loaded in the adjusting cylinder 58 via the conduit 61 and the connection 59.

Both loads cause a compression of the spring 50a, so that the pressure accumulator 22a, like the pressure accumulator 22 of the first embodiment, takes up a volume of pressure medium and the main piston 14 therefore maintains a specified brake pressure drop. It is returned in the direction of the emergency brake protrusion 16 a short distance in order to obtain it. The pressure accumulator 22a has the advantage that a defined volume is forced into the closing brake circuit I by forcing the piston 48a via the regulating piston 57. At the same time, due to the load of the adjusting piston 57, the connection 60 and the conduit 62
The hydraulic control valve 63 of the switching valve 19a is loaded via the switching valve 19a. This means that the switching valve 19 of the first embodiment
As well as allowing for sufficient pressure drop to load wheels prone to rocking. The automobile brake device 2a is
It has the advantage that the pressure accumulator 22a is filled only in the event of a locking hazard. Therefore, in the event of a failure of the pressure source 3 during braking, a relatively short distance of the pedal 9 is sufficient for emergency braking. The hydraulic control of the switching valve 19a is performed using the switching valve 1 which is electromagnetically controlled in the case of the first embodiment.
It has the advantage of being able to take over electrical switching useful for the operation of 9. In a second embodiment, instead of the electromagnet of the switching valve, the electromagnet 64 of the precontrol valve 56 is connected to the electrical control. Once the risk of locking has passed, the pre-control valve 56 is returned to its basic position, thereby closing the valve 19a.

23 and piston 48a are returned to their respective home positions. The pressure medium which is no longer required for this purpose is returned to the pressure source 3 by means of the precontrol valve 56 and the return conduit 65. At the end of braking, the pressure in the pressure accumulator 22a is released by the check valve 24 into the brake circuit (2) or into the secondary chamber 45.

Furthermore, in addition to the mask cylinder 13, a mask cylinder with a pressure accumulator 22 for a further closing brake circuit can also be installed. In this case, the master cylinder 13
For example, the left-hand front wheel brake can be connected to the left-hand front wheel brake, and the right-hand front wheel brake can be connected to the additional mask cylinder. The two mask cylinders are arranged in series, as shown for example in DE 29 08 480 A1. Furthermore, three master cylinders can be arranged in series for the six connected brake circuits, and all six brake circuits are each provided with one pressure accumulator 22.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first embodiment of an automobile brake system according to the present invention, and FIG. 2 is a longitudinal sectional view showing a second embodiment. 2.2a...Automobile brake device, 3...Pressure source,
4... Brake pressure control valve, 5... Distance simulator, 6... Side main member, 7... Pedal protrusion rod, 8...
Pedal lever, 9...petal, 10...cylinder,
DESCRIPTION OF SYMBOLS 11... Emergency brake piston, 12... Plunger, 13... Master cylinder, 14... Main piston, 15... Main piston return spring, 16... Emergency brake protrusion rod, 17... Return container, 18... First anti-skid valve, 19... Switching valve, 2021... Second anti-skid valve, 22/22a... Pressure accumulator, 2
3...Pressure accumulation type light valve, 24...Check valve, 25...
- Conduit, 26... Check valve, 27... Control cylinder,
28... Control piston, 29 Spring, 30... Protrusion rod,
31... Spring guide tube, 32... Compression spring, 33...
... Seal ring 34... Passage, 35... Seal ring, 36... Spring, 37... Seal ring, 38
...Wall, 39...Seal ring, 40/41...
Adjustment hole, 4243... Connection conduit, 44... Primary chamber,
45...Secondary chamber, 46.47...Connecting conduit, 48.
48a cylinder, 49/49a piston, 50/50a
... Spring, 51 ... Control inlet, 52 ... Spring, 5
3'53a, 53b... Conduit, 55... Pressure monitoring device, 56 Front control valve, 57 Adjustment piston, 58... Adjustment cylinder, 59, 60... Connection part, 61, 62...
Conduit, 63... Control inlet, 64... Electromagnet, 65.
・Return conduit

Claims (1)

[Claims] 1. An automobile brake system with an anti-skid device, comprising: a pressure source'; a brake pressure control valve operated via a pedal and a distance simulator; at least one closed brake circuit; It has a mask cylinder connected to a brake circuit, and the mask cylinder includes:
It has two main stones, a secondary chamber, an emergency brake protrusion rod, and a secondary chamber, and further, the secondary chamber is connected to a brake pressure control valve via a switching valve, and the anti-skid chamber is connected to a brake pressure control valve via a switching valve. The brake pressure control valve is disconnected from the brake pressure control valve and connected to the return container at times, and the main piston is moved by the pedal through the emergency brake protrusion in the event of an emergency. - in which the brake circuit (2, 2a) K, which is always connected, has a pressure accumulator (22, 22a) which, at least during the risk of locking, is connected to the closed brake circuit (I ) An automobile brake system having an anti-skid device, characterized in that the anti-skid device is connected to the K circuit (r) and is depressurized to the K circuit (r). 2. The pressure accumulator light valve (23) is configured as a hydraulically controlled two-point, two-position valve having a hydraulic control inlet (51); 2. Motor vehicle braking system according to claim 1, wherein the control inlet (51) is directly connected to the pressure source (3). 6 Pressure accumulator light valve (23) is connected to hydraulic control inlet (51
) with hydraulically controlled two-point and two-position valves,
and is connected to an electromagnetic pre-control valve (56), which is connected to a pressure source (3) and to a return conduit (65) leading to this pressure source. An automobile brake device according to claim 1. 4. - A switching valve (1) for supplying pressure medium to the next chamber (44)
7. Motor vehicle braking system according to claim 6, characterized in that 9a) is hydraulically controllable and is connected to a pre-control valve (56) of the accumulator filling valve (23). 5. It consists of a pressure accumulator (22a), a cylinder (48a), a piston (49a), and a return spring (50a), which acts on the piston (49a) and a return spring (50a).
0a), which has an adjusting piston (57) acting against the pre-control valve (56), which is movable in an adjusting cylinder (58) connected to the pre-control valve (56). Automobile brake equipment as described in Scope No. 7.