JPS643700B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control valve unit for an antilock system of a motor vehicle brake, of the type operated by a single control pressure. Pressure control valve units of this type are known (see German Patent Application No. 2,625,502).
In this known example, the relay valve merely monitors the outside air connection.

It is also known to design antilock pressure control valves as functionally complete relay valves (see German Patent Application No. 1630544). In addition to the elimination of special relay valves or quick release valves, which are often required, such valve configurations offer the following main advantages: Normal braking (without anti-lock control) ( 1) Rapid air supply and exhaust even in long brake lines (2) Rapid release action when the brake is released (3) Movement of the switching element during all braking operations (4) Small flow when used in control circuits Controlled braking in the form of a load-related controller with a cross-sectional area (in case of anti-lock control) (1) Pressure gradient independent of wheel cylinder volume.
That is, wheel cylinders of different sizes or cylinder volumes increased due to lining wear do not affect control performance.

(2) Connection and simultaneous control of multiple wheel cylinders is possible (for example, control of each axle).

However, the relatively large constructional volume of such a relay valve itself is detrimental to the control function. This means that the large switching times due to the large construction volume cause a pressure drop, which makes it impossible to supply sufficient control forces for individual wheel control.

Also, in terms of cost, relay-type pressure control valves for individual wheel control are too expensive. This is because one relay pressure control valve is required for each wheel.

Therefore, the relay pressure control valve is used exclusively as an axle-specific control valve, that is, for a control system in which a plurality of brake cylinders are controlled simultaneously to a common braking pressure level.

Instead, for wheel-specific control, switching valves (switching valves without relay function and without proportional action) that produce rapid switching with a small volume and simple structure are used, but these switching valves have different functional characteristics. Therefore, it does not have the desirable advantages of a relay-type pressure control valve for wheel-specific control.

The object of the present invention is to improve the pressure control valve unit for antilock devices of the conventional type so that it is possible not only to control each axle but also to control each wheel separately.
Moreover, it is to be possible to utilize it for purposes beyond the anti-lock mechanism.

The present invention solved this problem as follows.
That is, with one 3-port 2-position directional control valve for the purpose of controlling a single flow path or multiple flow paths, and one 2-port 2-position directional control valve for each flow path,
In both of these directional control valves of the type operated via piloted magnet valves, an additional 3-port 2-position directional control valve is provided; It has two inlets and one outlet, each inlet being connected to a control conduit from the brake valve and a reservoir respectively, and the outlet being connected to one of the pressure control valve units via one pilot magnet valve. It is configured so that it can be connected to two control rooms.

In such a configuration, an additional three-port, two-position directional control valve would monitor the control conduit from the brake valve and the reservoir pressure conduit. Both of these conduits can optionally be connected via the additional directional valve to the inlet of the pilot-magnet valve, so that, depending on the position of the additional directional valve, the pressure can be connected via the pilot-magnet valve. The control chamber of the control valve unit can be supplied with pressure from the brake valve or with reservoir pressure from a reservoir.

As a result of this configuration, braking pressure is introduced into the wheel cylinders not only by the brake valve but also by an additional three-port, two-position directional control valve.

Also, by utilizing an additional 3-port, 2-position directional control valve, it can be used for purposes other than the anti-lock function via a simple additional circuit.

In an embodiment of the invention, one additional three-port, two-position directional control valve may be located inside or outside the pressure control valve unit, and may also be located anywhere in the vehicle. This three-port, two-position directional control valve is preferably designed as a magnet valve. The introduction of the desired pressure into the individual wheel cylinders can also take place via a standard mechanically operated 3/2-way directional control valve, which can be activated by the driver, for example. During the control period 1
It can be locked via two locking levers.

An additional anti-theft mechanism is obtained if a locking button with a removable key is provided instead of a locking lever. That is, by braking the correspondingly connected wheel cylinders, it is possible to prevent the vehicle from running away.

Furthermore, when using magnet valves, the design according to the invention has the advantage that all valve parts, including the magnet valve itself, can be tested under pressure. In this case, although it is true that pressure is introduced into the relay valve by all the magnet valves working simultaneously, the generation of braking pressure in the wheel cylinder is prevented by the blockage of the directional control valve. Two test cycles will pass.

Furthermore, it is advantageous that the brake valve pressure is connected to the control chamber of the pressure control valve unit upon braking via the brake valve. This makes it possible to simultaneously release the required brake by applying the brakes by the driver and independently of the valve or magnet position; I needed a guarantee.

A further advantage is that only a small control chamber needs to be insufflated or evacuated in each case via a magnet valve or a mechanically operated 3/2-way directional control valve. These valves can therefore be manufactured with a small flow cross-section, which is also advantageous in terms of cost.

Such advantages also apply if an automatically load-dependent brake pressure regulator is used for pressure control in the control circuit.

Along with these advantages, significant cost savings are achieved by reducing the number of relay valves that are often required. For example, in the case of the rear axle of a towed vehicle, one relay valve, one anti-lock pressure control valve and one quick release valve can be omitted or significantly reduced in size from the conventionally used anti-lock pressure control valves.

Additionally, a single mechanical differential locking device can also be omitted, and an expensive separate anti-theft mechanism can also be omitted. The brake pressure regulating device, which acts in conjunction with the possibly required loads, can also be made considerably more compact.

The invention will now be explained with reference to the embodiment shown in the drawing: The reservoir 1 is connected on the one hand to a foot-operated brake valve 2 and on the other hand via a reservoir conduit 3 to a pressure control valve unit 4. has been done.
A control line 5 also leads from this brake valve 2 to a pressure control valve unit 4.

The reservoir line 3 leads in the pressure control line unit 4 into a reservoir pressure chamber 6 which has a valve seat 7 for a closing body 8 of a relay valve 9 . The pressure-free stem 10 of the closure body 8 passes through the valve seat 7 and carries a diaphragm disk 11 at its tip. This diaphragm disk 11 cooperates with a switching diaphragm 12 .

The diaphragm disk 11 and the stem 10 are located in a pressure exchange chamber 13, which is delimited by a valve seat 14, when the switching diaphragm 12 comes into contact with this valve seat 14. When exposed to reservoir pressure and separated from the valve seat 12, the switching diaphragm 12 is connected to the outside air via one ring passage 15 (see also FIGS. 2 and 3). Valve seat 14 and switching diaphragm 12 thus form one outlet valve. A control chamber 12' is provided below the switching diaphragm 12.

In the case of the two-channel structure shown in FIG. 1, the pressure exchange chamber 13 has two 2-port 2-position directional control valves 18,
It has two valve seats 16 and 17 for 9. The diaphragm closure members 20, 21 of these two-port, two-position directional control valves 18, 19 are arranged in a chamber 22, 23, respectively.
Wheel cylinder conduits 26, 27 leading to wheel cylinders 24, 25 are connected to 23. Control chambers 33, 34 are provided on the opposite side of the diaphragm closures 20, 21.

Inside the lower casing half 28 are three magnet valves 2.
9, 30, and 31 are arranged, and the magnet valve 30 in the center is a 3-port 2-position directional control valve,
The two magnet valves 29, 31 on both sides are two-port, two-position directional control valves. These magnet valves 29, 30,
Reference numeral 31 denotes a control chamber 1 provided on the casing upper half 50 side that covers the casing lower half 28 from above.
2', 33, and 34.
At the lower end of the lower casing half 28, one fresh air connection 32 with non-return valve monitoring is provided.

The mode of action is as follows: via the control line 5 the control chamber 12' connects to the magnet valve 30.
Pressure is supplied when there is no current. This causes the switching diaphragm 12 to move upward as seen in the figure, contacting the valve seat 14 and severing the connection between the reaction pressure and the air vent (see also FIG. 2).

The pressure-free stem 10 is then pushed up via the diaphragm disk 11, and the closing body 8 is moved away from its valve seat 7. Reservoir air enters reservoir pressure chamber 6
2-port 2-position directional control valve 1 opened from
8 and 19 to the wheel cylinders 24 and 25. Thus it is braked.

A pressure is generated as a reaction pressure in the pressure exchange chamber 13 and increases until it reaches the pressure level of the control pressure in the control chamber 12'. Due to the force balance produced in this case on the switching diaphragm 12, the spring-loaded stem 10 moves downwards so that the closing body 8 comes into contact with the valve seat 7. At this time, the switching diaphragm 12 remains in contact with the valve seat 14.
This causes the reservoir pressure, wheel cylinder pressure and air vent to be disconnected from each other.

As soon as the control pressure under the switching diaphragm 12 is reduced, for example via the brake valve 2 or the magnet valve 30, the switching diaphragm 12 is pushed away from the valve seat 14 by the reaction pressure in the pressure exchange chamber 13 and its The resulting reaction pressure, and therefore 2
If the port 2 position directional control valves 18, 19 are not closed, the braking pressure in the wheel cylinders 24, 25 will also decrease until a balance of forces occurs again.

In addition to controlling the wheel cylinder pressure by means of the control pressure, the pressure is controlled by two-port, two-position directional control valves 18, 19, which can control the pressure via pilot magnet valves 29, 31. It is also possible to disconnect the braking pressure in the cylinders 24, 25 from the pressure exchange chamber 13. Since the 2-port position directional control valves 18 and 19 can be used to cut the pressure independently of the respective position (pressure decrease or pressure increase) of the relay valve 9, the following pressure effects can be produced at the same time. Possible: (1) Pressure drop in both wheel cylinders 24, 25 (2) Pressure drop in one wheel cylinder and maintain pressure in the other wheel cylinder (3) Pressure maintain in one wheel cylinder and pressure in the other wheel cylinder Increase (4) Pressure increase in both wheel cylinders 24, 25 and also at different pressure heights.

In this way, common wheel control or individual wheel control can be carried out using just one pressure control valve unit 4, and in the case of individual wheel control, a switching valve that has been commonly used in the past can be used. An additional functional advantage is obtained by the relay action.

FIGS. 2 and 5 show a further advantageous embodiment of the two-channel pressure control valve according to FIG. This embodiment can also be applied to a three-pass system.

In the example of FIG. 2, a fourth magnet valve 51 is used, which magnet valve 51 is also arranged in the housing of the pressure control valve unit. This magnetic valve 5
1 allows the reservoir pressure to be introduced directly through the magnet valve 30 into the control chamber 12' via one internal reservoir pressure conduit 52. This means that
As a result, in addition to the brake valve 2, the magnet valve 51
This means that braking pressure can also be introduced into the wheel cylinder. In this case, on the one hand, the pressure introduced by the brake valve 2 is effective for all axles, while on the other hand, the pressure can also be controlled by the magnet valve 51 for the individual wheel cylinders 24, 25. .

With this one additional solenoid valve 51 and a relatively simple extension of the antilock logic circuit, drive slip control can be effected, for example, for the drive axle of a traction motor vehicle. In this case, the idling wheel detected by the antilock logic circuit via the wheel sensor is braked by the magnet valve 51, and at the same time the increase in braking pressure of the non-idling wheel is controlled by the associated 2-port 2-position directional control valve. occlusion.
By controlling both wheels to equal slip or rotational speed in this manner, the mechanical differential locking device can function precisely and at a significantly reduced cost.

The slip control can also be triggered by the driver in the conventional manner, for example via a switch or by means of an extended antilock logic circuit,
This can be done automatically by means of an anti-lock logic circuit which detects a spinning wheel through a positive slip limit and produces automatic slip control.

Of course, the magnet valve 51 does not necessarily need to be provided within the pressure control valve unit, and may be arranged elsewhere in the vehicle as a magnet valve 51', as shown in FIG. 3, for example.

Instead of one such magnet valve, the individual wheel cylinders can also be isolated by using one standard mechanically operated three-port two-position directional control valve 53 as illustrated in FIG. A desired pressure control can be effected, and this directional control valve can be kept locked, for example by the driver, by means of a lever 54 during drive slip control.

Instead of one lever 54, one locking button 5 with an extraction key as illustrated in FIG.
5, an additional anti-theft function is obtained via the 3/2-position directional control valve 53. That is, by applying braking pressure to the wheel cylinder, it is possible to prevent the vehicle from running away.

FIG. 6 shows the circuit of an antilock system with one pressure control valve unit 56, 57 for each axle 58, 59. In this case, the pressure control valve units 56, 57 are not constructed as relay valves, but are switch valves having an opening/closing function.
Instead of using one two-passage valve as shown, two single-passage valves may be used.

One 3-port, 2-position directional control valve 60 is constructed with one throttle point 61 in its switching position, so that the reservoir pressure rise when this directional control valve is switched is lower than when it is not switched. It is done slowly.

[Brief explanation of the drawing]

1 is a longitudinal sectional view of a pressure control valve unit according to the invention, FIG. 2 is a circuit diagram of a pressure control valve unit with one additional magnet valve inside, and FIG. 3 is a diagram of a pressure control valve unit with one additional magnet valve inside. A circuit diagram of a pressure control valve unit equipped with an external valve. Figure 4 is a circuit diagram when the directional control valve has an operating lever. Figure 5 is a circuit diagram when the directional control valve has a lock button. FIG. 6 is a circuit diagram of an antilock device equipped with two pressure control valve units. DESCRIPTION OF SYMBOLS 1... Reservoir, 2... Brake valve, 3... Reservoir conduit, 4... Pressure control valve unit, 5... Control conduit,
6... Reservoir pressure chamber, 7... Valve seat, 8... Closing body, 9
...Relay valve, 10...Stem, 11...Diaphragm disk, 12...Switching diaphragm, 12'...Control room,
13...Pressure exchange chamber, 14...Valve seat, 15...Ring passage, 16, 17...Valve seat, 18, 19...2 port 2
Position and direction control valve, 20, 21... diaphragm type closing member, 22, 23... chamber, 24, 25... wheel cylinder, 26, 27... wheel cylinder conduit,
33, 34...control room, 28...casing lower half,
29, 30, 31...Magnet valve, 32...Outside air connection part,
50... Upper half of casing, 51... Magnet valve, 52...
Reservoir pressure conduit, 53...3 port 2 position directional control valve, 54...Lever, 55...Lock button.

Claims (1)

[Scope of Claims] 1. A pressure control valve unit for an anti-lock device of an automobile brake, which is operable by one control pressure and is intended for controlling a single passage or multiple passages. One 3-port, 2-position directional control valve is provided in the interior, one 2-port, 2-position directional control valve is provided for each flow path, and both directional control valves are one additional 3-port 2-position directional control valve 5.
1, 51', 53, 53', 60, this additional directional control valve has two inlets and one outlet, each inlet being connected to a brake valve control conduit 5 and a reservoir. 1 are connected to each other, and the outlet is connected to one control chamber 12' of the pressure control valve unit via one pilot magnet valve 30.
characterized by being configured so that it can be connected to
Pressure control valve unit. 2. The additional 3-port, 2-position directional control valve is a magnetic valve, which in the de-energized state causes a connection between the control chamber 12' of the pressure control valve unit and the brake valve line and in the energized state. A pressure control valve unit according to claim 1, which is constructed to create a connection between the reservoir 1 and the control chamber 12'. 3 Additional 3-port 2-position directional control valve 53,5
2. A pressure control valve unit according to claim 1, wherein the pressure control valve unit 3' and 60 are arranged outside the lower half of the casing. 4 Additional 3-port 2-position directional control valve 53,5
A pressure control valve unit according to claim 1, wherein 3' is mechanically operable. 5 Additional 3-port 2-position directional control valve 53
Two locking levers 54 or one locking button 5
Claim 4 lockable via 5
Pressure control valve unit as described in . 6 Additional 3-port 2-position directional control valve 51,5
1', 53, 53' enables driving slip control in combination with one anti-lock logic circuit. 7 Additional 3-port 2-position directional control valve 53,5
2. The pressure control valve unit according to claim 1, wherein one anti-theft mechanism is provided by 3'. 8. Pressure control valve unit according to claim 1, characterized in that a constriction 61 is provided in the additional three-port two-position directional control valve 60 for retarding the build-up of reservoir pressure in the switching position.