JPH0624308A - Brake device - Google Patents

Abstract

PURPOSE: To obtain an inexpensive braking system composed of a small number of components by a method wherein a bypass which bypasses a line between a solenoid valve and a wheel brake cylinder to a brake line or a master brake cylinder and bypasses an electromagnetic edge and has a check valve is provided. CONSTITUTION: Solenoid valves 6 and 7 are connected to the front sides of the wheel brake cylinders 2 and 2 of front and rear wheels. Behind the brake cylinders 2 and 2, connection pipes 8 and 9 are made to join and connected to a brake line 5. A solenoid valve 10 is installed in the brake line 5. Bypasses 13 and 14 are installed for units composed of the solenoid valve 10 and composed of the solenoid valves 6 and 7 respectively and check valves 15 and 16 are installed in the bypasses 13 and 14 respectively. The check valves 15 and 16 are opened in a direction returning to a master brake cylinder 1. As a result, only the supply line of a return guide pump 18 is necessary for a middle/small size vehicle and hence two accumulators are eliminated and a buffer chamber 20 and two solenoid valves can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake device having a master brake cylinder connected to a wheel brake cylinder via a brake conduit and a connecting conduit, and an antiskid control is provided in the brake conduit and the connecting conduit. The present invention relates to a type in which a solenoid valve for performing and a return guide pump are interposed.

[0002]

2. Description of the Prior Art Circuits of this type are known in different types and configurations which are generally antiskid control systems. In the German patent application DE 38 19 812 A1, for example, an anti-skid control device is simultaneously connected to a traction slip control. Furthermore, starting from a hydraulically driven return-guiding pump without a low-pressure accumulator, this known device has three solenoid valves each for one anti-skid controller and one brake circuit each. is doing. Of course, also in this known braking device, a large number of constituent members, particularly check valves, are arranged,
Due to these numerous components, the overall construction cost of the brake system is high.

[0003]

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks in the prior art,
The purpose is to provide a low-cost brake device.

[0004]

According to the present invention, which has solved this problem, the conduit between the solenoid valve and the wheel brake cylinder is diverted towards the brake conduit or the master brake cylinder, which in turn bypasses the solenoid valve. , A bypass with a check valve is provided.

[0005]

According to the structure of the present invention, even if the solenoid valve is closed during the anti-skid control operation, the driver can rapidly reduce the brake pressure by releasing his foot from the brake pedal at any time. it can. When the foot is released from the brake pedal, the pressure medium flows from the wheel brake cylinder into the master brake cylinder through a separate return guide conduit. Such a low-cost circuit device is suitable for mounting in a mass class vehicle and an intermediate class vehicle.

If the brake pressure rises to an unacceptable level, the regulating device detects that the brake slip on at least one wheel is too great and closes the associated solenoid valve. Nevertheless,
If the slip continues, the motor for the return guide pump is started, the solenoid valve leading to the master brake cylinder is closed and, as mentioned above, the solenoid valve assigned to the wheel is opened again. . As a result, the master brake cylinder is separated and the pressure medium is guided back, so that the pressure in the wheel brake cylinder drops. In order to control the three solenoid valves in each circuit, the pressure in the wheel brake cylinders is controlled at the lock limit by means of a corresponding (not described here) regulating algorithm.

In the illustrated embodiment, the construction of the solenoid valve and, in particular, the installed state of the corresponding check valve in the solenoid valve is important. The non-return action is provided by the sealing lip in this embodiment. The sealing lip surrounds the corresponding valve element and is inserted, for example, in the blind hole of the casing. The sealing lip separates the annular chamber from the chamber and allows the brake fluid to flow in only one direction. The other flow direction is blocked by the sealing lip.
That is, when the counter pressure is applied to the outer lip portion of the seal lip, the lip portion is applied to the inner wall of the bag hole, so that the other flow is blocked.

In a solenoid valve which is connected to the front side of a wheel brake cylinder and performs the original anti-skid control, a conduit from the wheel brake cylinder is opened in the annular chamber, and a brake conduit or master from the bypass chamber. Returned to the brake cylinder. This means that when the solenoid valve is closed, the reverse flow path of the brake fluid is
It means that it is maintained open via a check valve configured as a cylinder lip. Of course, in this case the chamber is effectively decoupled from the connecting conduit to the solenoid valve or the return guide pump. This is done by the connection conduit opening at the bottom of the blind hole, which opening is sealed to the chamber by a seal. In this case, the lower part of the valve body is pressed axially against this seal, or this seal is wrapped around the lower part of the valve body into a radial seal and is supported against the wall of the blind hole.

That is, according to the present invention, the three brake circuits are used.
It only requires one configuration for all one valve. This arrangement, of course, has a built-in valve that is electromagnetically operated to open and close the brake flow. This valve is preferably arranged in the valve body and connects the annular chamber with a chamber at a solenoid valve connected to the rear side of the master brake cylinder or directly connected to the front side of the wheel brake cylinder. At the valve it is connected to a connecting conduit. For simplicity of construction, the valve consists of a ball valve, which is mounted on a push rod which is electromagnetically operated and which is assigned to the corresponding valve seat in the axial bore of the valve body. ing. In this case, the push rod is supported via a coil spring. This coil spring is designed to lift the ball valve from its seat when the solenoid valve fails and to keep the flow of brake fluid from the master brake cylinder to the wheel brake cylinder open anyway. This ensures the required positive actuation of the braking device.

The braking device of the present invention has an advantage over the known braking device in that the number of components is reduced and the structure of the solenoid valve is simplified.

The solenoid valve which is provided between the original solenoid valve directly connected to the front side of the wheel brake cylinder and the master brake cylinder and which has one connecting conduit leading to the two solenoid valves is a check valve. Can be diverted through the intervening bypass of the. In this case, a connecting conduit opens into the annular chamber, whereas a bypass leads from the chamber to the bridge conduit. This allows the solenoid valve to be bypassed in the direction towards the master brake cylinder when the pressure is high, even when in its closed position.

The return guide pump is directly connected to a connecting conduit leading to two solenoid valves connected to the front side of the wheel brake cylinder, and on the other hand opens into a brake conduit leading to the master brake cylinder.

In this case, it is sufficient to interpose one diaphragm. This throttling reduces the pulsations that occur when the brake fluid is guided back to the master brake cylinder, which in turn increases the quietness of the brake system. In a very simple embodiment, the additional buffer chamber is omitted. Furthermore, no additional accumulators are provided, as in known braking systems with antiskid control devices.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the brake system according to one embodiment of the present invention shown in FIG. 1, a master brake cylinder 1 is connected to a wheel brake cylinder 2 via two brake circuits I and II. These wheel brake cylinders are only shown schematically. A pedal 3 is connected to a piston rod 4 for producing a brake pressure, which acts on the master brake cylinder 1 and applies a pressure to the brake fluid in the corresponding brake chamber in this master brake cylinder 1. It is supposed to be added. Then, this brake fluid reaches the wheel brake cylinders 2 of the left front wheel (VL) and the right rear wheel (HR) in the brake circuit I.

As a part of this circuit device, one solenoid valve 6 or 7 is provided in front of the wheel brake cylinder 2 for the left front wheel and the wheel brake cylinder 2 for the right rear wheel, respectively.
On the rear side of these solenoid valves 6 and 7, corresponding connecting conduits 8 and 9 join and connect to the brake circuit 5. A further solenoid valve 10 is connected in the brake conduit 5.

As shown in FIG. 5, the solenoid valve 10 is further assigned a bypass 11 having a check valve 12.

For the unit consisting of the solenoid valve 10 and the solenoid valve 6 or 7, there is also a bypass 13 each.
And 14 are provided, and the bypasses 13 and 14 are provided.
A check valve 15 or 16 is arranged in each case. The check valve 15 or 16 can be opened in a direction returning toward the master brake cylinder 1.

The connecting conduits 8 and 9 are connected by a return guide pump 18
The outlet conduit 19 of this return guide pump 18 reopens into the brake conduit 5 between the solenoid valve 10 and the master brake cylinder 1 in front of this opening. In addition, a buffer chamber 20 and a diaphragm 21 can be provided in the.

Since the brake circuit II has the same shape as the brake circuit I, a description of the brake circuit II will be omitted, but a corresponding return guide pump 18a of the brake circuit II is connected to the motor 22. It should be pointed out that this motor 22 is also adapted to operate the return guide pump 18 of the brake circuit I.

The mode of operation of the brake system according to the present invention will be described below.

In the normal brake operation process, pressure is applied to the pedal 3 and the piston rod 4 in the brake chamber (not shown) is operated to feed the brake fluid into the brake circuits I and II. This pumped brake fluid reaches the wheel brake cylinder 2 via the brake conduit 5 in the brake circuit I by the opened solenoid valves 10 and 6 or 7. A brake actuation process is carried out via the wheel brake cylinder 2.

When a sensor (not shown in detail) confirms that the left front wheel (VL) is locked, the circuit device is activated. When the solenoid valve 6 is closed, no further pressure is built up in the wheel brake cylinder 2 of the left front wheel. This is because the connecting conduit 8 is disconnected from the brake conduit 5.

When the braking slip on the left front wheel becomes larger, the motor 2 is started and the return guide pump 1
8 is activated. Solenoid valve 10 and solenoid valve 7 are closed,
The solenoid valve 6 is opened again. As a result, the master brake cylinder 1 is disconnected from the wheel brake cylinders 2 of the left front wheel and the right rear wheel, and the connection between the left front wheel and the right rear wheel is interrupted.

Thus, through the return guide pump 18,
Too high brake pressure in the wheel brake cylinder 2 of the left front wheel is reduced and brake fluid is supplied again to the master brake cylinder. This is the buffer chamber 20 and the diaphragm 2.
However, if the condition in which the buffer chamber 20 is not provided can be accepted, the buffer chamber 20 may be omitted.

According to the regulation algorithm not described here, the solenoid valve 6 is closed again and the solenoid valve 1 is closed.
Since 0 and 7 are released again, a further increase in brake pressure in the wheel brake cylinder 2 of the right rear wheel is possible. Since the rear wheel on the right side becomes unstable during the course of the braking operation, the same anti-skid control as on the front wheel on the left side is performed. The subsequent pressure increase and further modulation is carried out as described above.

As is known, the conventional anti-skid control system in the K-brake circuit division has the following components.

Two return guide pumps Two accumulators Two buffer chambers Four solenoid valves in the wheel brake cylinder Four solenoid valves in the brake conduit This eliminates at least two accumulators. This is because the supply conduit of the return guide pump is sufficient for small and medium-sized vehicles. Furthermore, the buffer chamber 20 may be omitted if the buffer chamber 20 is not provided. In any case, two additional solenoid valves in the brake conduit can be omitted.

A separate return guide conduit 13 or 14 leading to the master brake cylinder is required to avoid post-braking after de-braking.

In the TT-brake circuit division as shown in FIG. 2, the following corresponding circuit arrangement is provided.

A) K- for the brake circuit of the front axle
The arrangement of the members is selected according to the division (see FIG. 2).

B) The brake circuit for the rear axle is provided with an inlet solenoid valve and an outlet solenoid valve as in the prior art, but the accumulator is omitted.

In this case, the braking device comprises two return guide pumps, two conventional solenoid valves, one solenoid valve in the brake conduit and two solenoid valves modified before the wheel brake cylinder. Have This brake system requires only five solenoid valves as a whole, eliminating the accumulator and the buffer chamber.

In order to be able to fulfill the functions of the modified solenoid valves 6 and 7, these solenoid valves 6, 7
Must have a special structure. Two embodiments for such a type of valve are shown in FIGS.

The solenoid valve 6/7 is arranged in the casing block 23. For this purpose the casing block 23
A bag hole 24 is provided inside. The connecting conduit 8 branches from the bottom portion 25 of the blind hole 24 and extends to the return guide pump 18. A bypass conduit 13/14 opens laterally near the bottom 25 and extends to the master brake cylinder 1. A conduit 26 leading to the wheel brake cylinder 2 is provided above the bypass conduit 13/14 at a distance.
Is provided.

The solenoid valve 6/7 together with the valve body 27 has a blind hole 24.
Inside this blind hole 24 an annular chamber 28 for the opening of the conduit 26 is formed. This annular chamber 28
Is separated from the chamber 30 by a sealing lip 29, from which the bypass 13/14 opens. The seal lip 29 guides the brake fluid from the wheel brake cylinder back to the chamber 30 via the seal lip or to the master brake cylinder 1 via the bypass 13/14 when the pressure in the conduit 26 rises. Work as you can. For this reason, the valve body does not at least partially abut the wall of the blind hole 24. The outer portion of the seal lip 29 is flexibly bent to open the space between the seal lip 29 and the wall portion of the bag hole 24. On the other side of the seal lip 29, the annular chamber 2
8 is sealed by an O-ring 31.

The lower part 32 of the valve body 27 presses against the bottom 25 of the blind hole 24, in which case according to the invention an additional sealing element, in particular a sealing ring 33, is inserted.
In this way, the connecting conduit 8 leading to the return guide pump 8
/ 9 is connected to the conduit 26 leading to the wheel brake cylinder 2 only when the valve 34 in the valve body 27 is opened.

In order to construct such a valve 34, the valve body 2
A stepped hole 35 is provided in 7. This stepped hole 3
5 is closed by a filter 36 towards the connecting conduit 8/9. A sleeve 37 is inserted in the stepped hole 35, and the sleeve 37 has an opening 38. This opening 38 forms a valve seat for a ball valve 39 supported by a push rod 40.

A valve chamber 41 is formed between the push rod 40 and the sleeve 37. In this case, the valve chamber 4 is formed.
In FIG. 1, the push rod 40 is supported by the sleeve 37 via the coil spring 42.

The valve chamber 41 is connected to the annular chamber 28 via the lateral hole 43 and the filter seat 44.

A mover 45 is in contact with the push rod 40, and the mover 45 is arranged in an airtight casing 46 and surrounded by a coil package 47. This coil package 47 has a connection lug 48
A current is supplied via the. The coil package 47 is
It acts to move the push rod 40 within the stepped hole 35. In this case, the ball valve 39 is mounted on the opening 38. On the other hand, when no current is supplied to the coil package 47, the ball valve 39 is forced to move its seat or opening 38 by the counter pressure of the coil spring 42.
Be lifted from. In this way, the connection between the wheel brake cylinder and the return guide pump is closed or opened.

Further, when the seal lip is used, it is not necessary to arrange the check valves 15 and 16 separately. Then
The seal lip 29 acts as a check valve. Because, via the bypass 13 or 14, the brake fluid flows through the chamber 30.
This is because it does not reach the annular chamber 28.

The structure of the solenoid valve 6a / 7a shown in FIG.
It differs from the solenoid valve shown in FIG. 2 only in that the seal 33a is configured as a radial seal rather than an axial seal. Therefore, the lower portion 32 of the valve body 27a is
a is of long construction and is located in the additional hole 49. A connecting conduit 8/9 opens at the bottom 50 of this hole.

Furthermore, the solenoid valve 10 is also constructed accordingly. In this case, the connecting conduit 8/9 opens as a conduit 26 into the annular chamber 28. The bypass 11 is separated from the annular chamber 28 by a seal lip 29. In this embodiment as well, the seal lip 29 acts as the check valve 12. In this way, the brake conduit 5 is located at the bottom 25 of the blind hole 24.
Or it opens in 50. The valve device is otherwise the same as that of the above-mentioned embodiment.

By selecting the algorithm accordingly, it is possible, according to the construction of the braking device of the invention, to increase the brake pressure of one wheel with one brake circuit while at the same time reducing the brake pressure of the other wheel. With the only exception that it is not possible, it is comparable to the operation of a conventional anti-skid controller. However, reduced pressure is generally a priority. That is, the partner wheels in the same brake circuit are maintained in the pressure-holding state during depressurization. The same thing as this pressure increase (hydraulic-
This also applies to multiplexes. With such a method, 97% of the antiskid-brake efficiency that is currently common
Antiskid-brake efficiency up to is obtained.

Another advantage of the circuit arrangement according to the invention lies in the fact that a gradient curve switch for pressure increase takes place immediately after the return guide pump in the brake circuit carries out the pumping operation. It is proved by the electrical schematics and equations shown below.

[0046]

[Equation 1]

[0047]

[Outer 1]

[0048]

[Equation 2]

[0049]

[Outside 2]

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a brake device including a circuit device for K-brake circuit division (diagonal division).

FIG. 2 is a block circuit diagram of a braking device having a circuit device for TT-brake circuit splitting (front axle, rear axle-split).

FIG. 3 is a longitudinal sectional view of a 2/2 stroke-solenoid valve according to the present invention in a use position.

FIG. 4 is a longitudinal sectional view of a 2/2 stroke-solenoid valve in a use position according to another embodiment of the present invention.

5 is a schematic diagram showing a bypass that bypasses an electromagnetic valve of the circuit device shown in FIGS. 1 and 2. FIG.

[Explanation of symbols]

1 master brake cylinder, 2 wheel brake cylinder, 3 pedal, 4 piston rod, 5 brake conduit, 6, 7; 6a, 7a solenoid valve, 8, 9 connection conduit, 10 solenoid valve, 11 bypass, 12
Check valve, 13, 14 bypass conduit, 15, 16 check valve, 17 connecting conduit, 18, 18a return guide pump, 19 outlet conduit, 20 throttle, 2
1 buffer chamber, 22 motor, 23 casing block, 24 blind hole, 25 bottom part, 26 conduit, 2
7, 27a valve body, 28 annular chamber, 29 seal lip, 30 chamber, 32, 32a lower part of valve body 27a, 33, 33a seal ring, 34 valve, 35
Stepped hole, 36 filter, 37 sleeve, 3
8 openings, 39 ball valves, 40 push rods, 41 valve chambers, 42 coil springs, 43 lateral holes,
44 filter sheet, 45 mover, 46 casing, 47 coil package, 48 connecting lug, 50 bottom

Claims (10)

[Claims] 1. A brake device comprising a master brake cylinder connected to a wheel brake cylinder via a brake conduit and a connecting conduit, wherein a solenoid valve for performing anti-skid control is provided in the brake conduit and the connecting conduit. In the type in which the return guide pump is interposed, the conduit between the solenoid valve (6, 7) and the wheel brake cylinder (2) is diverted to the brake conduit (5) or the master brake cylinder (1). The brake device is further provided with a bypass (13, 14) having a check valve (15, 16) that bypasses the solenoid valve (6 or 7, 10). 2. At least one solenoid valve (6, 7, 1)
0) has a valve body (27) inserted into the blind hole (24), and the valve body (27) has a radius relative to the blind hole (24) via a seal lip (29). Directionally supported to allow brake fluid to flow from the annular chamber (28) toward the chamber (30), thereby forming a check valve (12, 15, 16). The brake device according to item 1. 3. An annular chamber (2) in a solenoid valve (6, 7).
A conduit (26) extending from the wheel brake cylinder (2) is opened in 8), and a bypass (13, 14) from the chamber (30) is guided back to the brake conduit (5) or the master brake cylinder (1). Claim 2
The described braking device. 4. A connecting conduit (8, 9) in which the chamber (30) of the solenoid valve (6, 7) extends on the other side of the sealing lip (29) to the solenoid valve (10) via a seal (33, 33a). 4. The braking device according to claim 3, which is partitioned off with respect to the return guide pump (18). 5. A valve body (27) of a solenoid valve (6, 7) is supported by a bottom portion (25) of a blind hole via an axial seal (33) and a lower portion (32). The brake device according to claim 4. 6. The lower part (32a) of the valve body (10) of the solenoid valve (6, 7) is engaged in the hole (49) and laterally through the radial seal (33a). The braking device according to claim 4, which is supported by (49). 7. A connecting conduit (8, 9) is connected to the annular chamber (28) in the valve body (27) via a valve (34).
The brake device according to any one of claims 4 to 6. 8. A solenoid valve (10) intervenes a check valve (12) in a brake conduit (5) where two connecting conduits (8, 9) with solenoid valves (6, 7) branch off. Bridged by a bypass (11),
The brake device according to any one of items 1 to 7. 9. An annular chamber (28) in a solenoid valve (10).
9. The braking device according to claim 8, wherein the connecting device (8, 9) is open therein and the bypass (11) extends from the chamber (30) to the brake conduit (5). 10. The connecting conduit (8, 9) is a connecting conduit (1).
7) connected to a return guide pump (18) via an outlet conduit (1) of the return guide pump (18)
Brake device according to any one of claims 1 to 9, characterized in that 9) is guided back to the master brake cylinder (1) via a throttle (21).