DE2406169A1 - PRESSURE REGULATING DEVICE FOR ANTI-LOCK REGULATOR - Google Patents

Description

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98 vol. Victor Hugo 8 = February 1974

9 2 Clichy, France Amialt file M-2954

Pressure control device for anti-lock regulator

The invention relates to a pressure control device for anti-blocking devices for vehicles.

I In anti-lock braking systems for motor vehicles, the 'The speed at which the fluid pressure in the brakes!

increases, so that e.g. the risk of blocking

I ^!

j of a vehicle wheel is not displayed prematurely. This is emergency;

| Manoeuvrable, as too rapid a pressure increase can lead to

j brake the wheels so hard that an anti-lock braking cycle

j is conducted before the greatest possible adhesion of the wheel to the ground

! which is reached.

Sometimes the speed of pressure increase in the brakes controlled in that calibrated or throttling openings are provided in the lines between the brake pressure generator and the wheel brake cylinders. Delay these throttling passages However, the main factor is the reaction of the brake system when the brake pedal is pressed and released.

j To avoid this real-

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In case of delay, a solenoid valve can be arranged in the brake system in order to short-circuit the calibrated or restricting passages, wherein the bypass valve is closed by an electromagnet, which ii conventional form in the pressure regulator is built in. In this case, the solenoid is operated at the same time as the solenoid that controls the pressure relief and isolation valve controls, and remains under tension during the entire anti-lock braking phase, which results from a series of anti-lock modulation cycles consists.

This solution has several disadvantages, the most serious of which are the following. First, the solenoid valve must be the Bypass shut off, operated practically at the same time as the well-known pressure relief and isolation valve. Because the latter one is a fast working valve, the bypass valve must have a very short response time and is therefore expensive. Second should the electronic anti-lock braking unit has also been modified accordingly and consequently their price increases.

According to the invention there is provided a pressure regulator for an anti-lock brake system proposed, which in a housing with an inlet port, an outlet port and a relief port

Which
first chamber is connected to the inlet opening by a first conduit with a first constriction, to the outlet opening by a second conduit and to the relief opening by a third conduit, furthermore has an electromagnetically controlled valve in the first chamber which

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lines is pressed into a first position in which the third line shut off and the first line is opened, xfobei the valve under the influence of one of the first spring devices counteracting Magnetic member reaches a second position in which the third line is opened and the first line is closed as well as a second chamber in connection with the inlet port, a fourth lei connecting the second chamber to the outlet opening and bypassing the first constriction and the first chamber device, a second valve in the second chamber which is urged into an open position by second spring devices, wherein the second valve is brought to a closed position by a piston, and the piston to fluid pressure responds in a cavity which opens into the third conduit between the first chamber and a second constriction, wherein the second valve in its closed position to the pressures acting in each case on one of its end faces responds in the second chamber and in the fourth line.

As explained in detail in the description, the closing of the second valve achieved during the brake pressure relief phase by reducing the pressure in the fourth Line (e.g. downstream of the second valve) and by an increase in pressure in the cavity.

In the following an embodiment of the invention is based on the single figure of the drawing described in which an inventive and in a hydraulic anti-lock brake system

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- 4 is shown for a vehicle inserted pressure regulator.

In the drawing, the pressure regulator 1o according to the invention has a Inlet 14, outlet 16 and relief port 18. Of the Inlet 14 is connected by a line to a brake pressure control valve V, which is operated by a pedal P and from a container R is supplied with fluid. The outlet 16 is connected to the brake actuators F. The relief opening 18 is in connection with a low pressure tank ß.

The pressure regulator 1o consists of a housing 12, which consists of several Share can exist and in which a first chamber 2o through a line 22 having a throttle point 24 to the inlet 14 and through a second line 26 to the outlet 16 and through

72
a third line 28 having a second throttle point, the effective cross section of which is adjustable, is connected to the opening 18.

The first chamber 2o contains a first valve 32. The valve is electromagnetically controlled and is operated by first spring devices 34 held in a first position in which the third line 28 is closed and the first line 22 is open. A magnetic one Member 33 can, against the force of the spring devices 34, bring the valve 32 into a second position in which the line 28 is open and line 22 is closed.

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The line 28 contains a space 36 in which a valve 4o is housed which is held in its open position by spring devices 4 2. A displaceable in a bore 46 in the housing 12 Piston 44 is exposed to the fluid pressure prevailing in the second line 26 and acts against the force of the Spring device 4 2 on the valve 4o. If the fluid pressure in the brake F is higher than a predetermined value, it is Valve 4o is closed and the fluid flowing from the chamber 2o passes through a throttle point 3o, bypassing it

3o of the valve 4o in the return 18. The throttle point has a smaller effective cross-section than that of the throttling point 7 2. In another embodiment of the invention, the throttle point 3o provided as a bypass to the throttle point 72.

In addition, the pressure regulator in the housing 12 contains a second chamber 48 which connects to the inlet 14 and through a fourth conduit 5ö is connected to the outlet 16. A second valve 5 2 is housed in the chamber 48 and is operated by spring devices 54 held in its open position.

A stepped piston 56 is arranged so as to be sealingly displaceable in a stepped bore in the housing 12. The piston face 6o with the larger area divides a cavity 58 in the offset bore, which with the third line 28 at a connection point 38 is connected above the valve 4o and the two throttle points 3o and 7 2. The piston face 6 2 with the smaller area cooperates with valve 52 and is therefore

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half exposed to the fluid pressure prevailing in chamber 48. The stepped piston 56 moves the third valve 5 2 into a closed position in which the fourth passage 5o is closed, when the pressure acting on the valve overcomes the spring devices 54 and presses the valve against a seat 64.

The pressure regulator described above works as follows:

the
When the logic unit (not shown) controlling the anti-lock device initiates a braking cycle, the armature 33 is activated and moves the valve 32 upward in the drawing. This prevents fluid from valve V from reaching brake F via inlet 14, restriction 24, line 26 and outlet 16. The brake is then relieved via line 26, chamber 2o, line 28, throttle point 7 2 and opening 18. The relief is controlled by the piston 44, by means of which the valve 4o can be closed when the pressure in the line 26 is sufficiently high. In such a case, as a result of the difference in the effective cross sections 3o and 72 of the throttle points, the speed of the pressure relief is reduced, as is known.

During pressure relief, a pressure P- builds up above the throttle point 7 2 or the throttle point 3o. This pressure P ₁ is used as a control pressure in order to actuate the stepped piston 56, which in turn controls the closing of the bypass valve 52. The pressure P ₁ causes the piston 56 (in the figure) to move upwards and against the force of the spring devices 54 that

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to press the valve 5 2 on the seat 64, which is at the entrance to line 5o is located. Due to the fact that the valve 5 2 is responsive to the fluid pressure applied to both of its wide sides The closing of the valve 5 2 is effected by a suction effect in the line 5o xu during the relieving of the brakes.

For the system to work satisfactorily, the valve 5 2 cooperate with the seat 64 in a sealing manner. Through a suitable Choice of the effective areas of the valve seat 64 and the end faces 6o and 62 of the stepped piston 56 is also made with a relatively small one

Brake pressure value (approx. 10 kg / cm) at the moment of activation of the solenoid valve 33 ensures that the valve 5 2 closes with ease. When the logical unit has determined the Ending brake pressure relief will energize the valve armature ended, the valve 32 is moved back into the position shown in the drawing and the valve 5 2 is by the difference the pressures acting on its two sides are kept closed, creating a direct connection between the control valve V and the brake F is prevented, which therefore via the throttle point 24 the line 22, the chamber 2o and the line 26 with Pressure medium is supplied. Consequently, during the successive * lowing cycles of the same braking process, the brake pressure slowly increases again. In the preferred embodiment now described According to the invention, the valve 5 2 is transmitted in front of an opposite * from the brake F in the line 5o Load the fluid pressure by arranging a check valve 66

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Known construction in the line 5o protected so that the line only transport fluid from the chamber 48 to the opening 16 can. In addition, a line 68 is provided between the inlet 14 and the line 26 with a check valve 7o, which prevents fluid from flowing from port 14 into conduit 26, allowing rapid and indefinite degradation brake pressure is possible during normal braking when the anti-lock braking system does not intervene.

If the driver of the vehicle now lets go of the brake pedal, the input pressure supplied by the control valve V is low and the spring devices 54 push the valve 5 2 from its seat. The pressure regulator 1o is then again in a position in which the Valve V directly via inlet 14, chamber 48, line, check valve 66 (if present) and port 16 directly is connected to the brake, and consequently guarantees a rapid increase in the brake pressure in the event of a further braking process is.

It should be noted, however, that when refilling the brake F, consequently after closing the valve 32 in the in the Drawing position shown, the fluid located in the chamber 58 continues to flow into the container B, so that the pressure in the chamber is very similar to the pressure in B. Therefore, the fluid pressure coming from the brake F drops quickly when the valve 32 is turned on again, as when the brake F for a very short period of time directly with the container B would be connected as the liquid rapidly enters chamber 58

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flows. This phenomenon is used during the anti-lock braking process to compensate for part of the delay in opening the electromagnetic valve.

Although the fluid pressure regulator has been described with reference to a hydraulic brake circuit, it could of course can also be used in a pneumatic system without departing from the scope of the invention.

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Claims (4)

Societe Anonyme D.ß.A. "': ·: Λ siK Bd. Victor Hugo February 8, 1974 2 Clichy, France Attorney's file M-2954 patent claims 1. Pressure control device for anti-lock regulator contained in one Housing with an inlet opening, an outlet opening and a relief opening a first chamber which is passed through a first conduit containing a first constriction with the inlet opening, through a second conduit with the outlet opening and is connected to the relief port by a third conduit containing an electromagnetically controlled valve which is housed in the first chamber and is pressed by first spring devices into a first position in which the third Line is closed and the first line is opened, the valve being counteracted under the influence of a magnetic member the force of the first spring device can assume a second position in which the third line is open and the first line is closed, characterized by a second with the inlet opening (14) communicating chamber (48), by a fourth line (5o), which connects the second chamber (48) to the outlet opening (16) and the first constriction (24) and the first chamber (2o) bypasses by a second, housed in the second chamber (48) and by a second spring device (54) held in an open position valve (5 2), where- -11-409833 / 0831 at the second valve (5 2) by one on the fluid pressure in a cavity (58), which opposite the third line (28) between the first chamber (2o) and a second The constriction (72) is open, the responsive piston (56) is brought into a closed position, the valve (5 2) in the closed position on the jevreils acting on one of its two end faces fluid pressures in the second chamber (48) and in the fourth line (5o) responds. 2. Pressure regulator according to claim 1, characterized in that the piston (56) is a stepped piston whose larger effective Area (6o) into the cavity (58) and its smaller effective area (5 2) also protrudes into the chamber (48). 3. Pressure regulator according to claim 1 or 2, characterized in that that a third valve (4o) is provided, which is in the third line (28) between the connection point (38) of the Cavity (58) and the relief opening (18) and a third constriction (3o) through which the third valve (4o) is bypassed, the third constriction (3o) having a smaller effective area than the second constriction (72), and wherein the third valve (4o) is held in an open position by a spring device (42) and by an open the piston (44) responsive to the fluid pressure at the outlet port (16) is brought into a closed position. 4. Pressure regulator according to one of the preceding claims, characterized in that that a first check valve (66) in the 409833/0831 fourth line (5o) is provided, which allows a flow of fluid from the chamber (48) to the outlet opening (16), and a second check valve (7o) through which on the one hand the first constriction (24) and the first chamber (2o) and on the other hand the second chamber (48) and the first check valve (66) are bypassed, the second check valve (7o) normally allowing fluid flow from the exit port (16) to the entry port (14). 409833/0831