JP2003165433A - Redundant pressure selector valve for electropneumatic braking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for selecting a redundant pressure with considerably reduced cost and number of components as compared with a known redundant pressure selector valve for an electropneumatic braking device. <P>SOLUTION: In the redundant pressure selector valve, a wheel EBS braking pressure modulator is extended in regard to a redundancy function in a simple form, and at least an existing composition unit is used in a braking pressure modulator itself for that purpose. Since generation of the redundant pressure comprises a partial function of a brake value generator and consequently a braking pressure is formed for a wheel brake cylinder, there is no need for a device other than the modulator. A redundancy selector valve is formed as a small cylindrical member, it is attached in a brake modulator, and it can be very easily screwed as a cartridge in a blind hole provided with a screw. In redundancy, the redundant pressure is applied to a terminal which can be accessed from the outside of the redundancy selector valve, the pressure is enhanced via a relay valve portion of the braking pressure modulator, and it is transferred to the wheel brake cylinder. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a redundant pressure produced in a mechanical-pneumatic manner in the event of an electronically controlled brake pressure failure, which is used especially for vehicle braking. Valve device for an integrated electronic pneumatic braking device.

[0002]

2. Description of the Prior Art In the prior art there is provided a series of solutions for switching the brake pressure from electronically controlled brake pressure [EBS brake pressure] to redundant pressure; It must be configured to automatically activate in case of failure.

WABCO-published "EBS (EP
B) -Elektronisis gergelte
s Bremssystem ”[Wabcodruck
815,000 231 3 / 02.98], a redundant valve “480 205 ... 0” is known [here page 13/14], where redundancy in an intact electropneumatic braking circuit is described. A 3/2 directional control valve function is utilized to suppress. The EBS brake pressure is input to the input terminal [here (4
2)] and through the pressure passage in the magnet and through the valve seat of the 2/2 ABS solenoid valve that opens in the case of non-ABS, the 3/2 directional control valve switching piston [here the upper piston] Reach the control plane.

By this pressure actuation, the switching piston is moved downwards, so that the valve seat of the plate valve located above and operated by it is closed and the redundant pressure input terminal [here (41)] is connected. The redundant pressure exerted is cut off; the control of the brake pressure itself is thereby effected by the axial modulator exerting pressure on the pneumatic brake conduit [here (21), (22)], so that EBS brake pressure is present. , The function of the redundant valve is cut off.

In the case of ABS control, it is supplemented that a current flows through the magnets of the 2/2 ABS solenoid valve, its valve seat is closed and the pressure exerted on the switching piston is thereby confined; The undesired opening of the plate valve results when the brake pressure is dismantled within the control framework.

If no pressure is applied to the control surface of the switching piston, the plate valve is open and the redundant pressure is arranged in the relay part of the redundant valve, ie spatially below the switching piston. Reached the control ring surface of the relay piston. This relay part outputs a redundant pressure by increasing the amount of air, but with a pressure decrease of 2: 1 (area ratio, feedback ring face to control ring face) at the redundant pressure output terminal [(2) here]. Output, and this is
From here it is transferred to the shaft modulator and the brake conduit.

The well-known WABC shown in cross section in FIG.
O device "Einfach-Redundanz 480
EBS with a fault in 205 104 0 "
In the (redundant case), the redundant pressure applied to the control pressure input terminal 52 and generated by the brake value generator is
The air is increased from the relay valve output terminal 51 and output.
In this switching position, no air flows through the coil of the 3/2 solenoid valve 55, which acts as a pilot valve, so that the air relief seat 56 is closed; on the contrary, the ventilation seat 57 is open, so that the control pressure The pressure applied to the input terminal 52 reaches the relay valve control space above the relay valve piston 53 via the pressure passage 58 inside the control electromagnet and the open vent valve seat 57. By manipulating the outlet valve 54 by means of the relay valve piston 53, an amount of air is flow-controlled towards the relay valve output terminal 52 such that the pressure just controlled always results in a pressure equal to the redundant pressure.

In case of EBS without failure (in the case of EBS)-
This condition is shown in FIG. 5—the vent seal 57 is closed; the control space of the relay valve 57 is now vented via the open air vent seal 56 and the device air vent 59. Relay piston 53 is returned to its spring-loaded basic position. Since the control valve 54 remains at the spring-loaded basic position and shutoff position,
The relay valve output terminal 51 is cut off from the supply pressure input terminal 50.

Therefore, the above-mentioned valve device can utilize the redundant brake pressure with the increased air amount even in the case of the redundant condition. A separate valve means is required for the supply of brake pressure into the brake cylinder of the braking device or for the supply of electronically generated brake pressure in the case of EBS.

In the case of generating redundant braking pressures according to the prior art, these devices require a large construction space and the required precision of the components imposes a comparatively high manufacturing cost. It is a disadvantage. In addition, on the one hand, for producing brake pressure, on the other hand for EBS or in the case of redundancy brake pressure switching, and finally for supply into the brake cylinder,
Various modalities of equipment are required.

[0011]

SUMMARY OF THE INVENTION The object of the invention is therefore to provide a device for redundant pressure switching, which has a considerable cost reduction and a reduced number of parts over the known solutions. To provide.

[0012]

This problem is solved by the invention described in claim 1 as follows. That is, a) a first terminal is provided as an atmospheric pressure input terminal, to which a redundant pressure of an electronic pneumatic braking device can be applied; b) a second terminal is provided as a pneumatic air release output terminal. C) a third terminal is provided, which is formed as a pressure input terminal and as a pressure output terminal; d) the third terminal forms an electronically controlled pneumatic brake pressure. Is connected to the output terminal of a valve pre-control unit provided for this purpose; e) two valve switching positions are provided;
f) the first valve switching position, the redundant position, is occupied when pressure is applied to the first terminal; g) the second valve switching position, the electronic braking position, the pressure at the first terminal. Occupied when not present and at least temporarily applying pressure to the third terminal. Variants and advantageous embodiments of the invention are described in the dependent claims.

The invention has the advantage that it can be integrated directly into the brake pressure modulator of an electronic pneumatic braking device, which additionally reduces the construction space.

By being integrated into the brake pressure modulator,
Advantageously, devices which are in any case provided in the brake pressure modulator are used together; devices for boosting the air quantity in this way are present only on one side and these devices depend on the mode of construction. Used for EBS and redundancy.

Finally, only two components are still needed for the electronic pneumatic braking system, namely a brake value generator (or motor vehicle brake valve) for generating electrical and pneumatic braking schedules, And a brake pressure modulator equipped with a switching valve device according to the invention is needed.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows a redundant directional control valve 4 according to the invention when a brake pressure modulator is configured as the EBS wheel modulator 1, the redundant directional control valve having a different brake pressure modulator configuration. Supplementally, it can also be used in.

For the formation of an electrically controlled pneumatic brake pressure, a solenoid valve pre-control unit 2 is provided, which pre-control unit comprises two 2/2 operating in a clocked manner. 2 A solenoid valve, that is, a vent solenoid valve 5 that is connected to the pressure supply unit 20 and closes when no current flows, and a current that is connected to the air escape unit 21 via a redundant switching valve 4 described later does not flow. It consists of an air release solenoid valve 6 that opens.

In this front-end control unit part of the EBS wheel modulator, the brake control pressure is created in the control space of the relay valve 3 by the operation of the solenoid valves 5 and 6, which control pressure is increased by the relay valve. It is pneumatically connected to the relay valve part 3 for output to the brake pressure output terminal 22; this arrangement is pneumatically connected to the brake cylinder of the wheel provided with the EBS wheel modulator.

The redundant switching valve 4 is pneumatically controlled 3
It is configured as a / 2-way control valve, i.e. has two switching positions and three terminals. This is shown in FIG. 1 in its first switching position, the electronic braking position.

The first terminal 7 is designed as an input terminal and a redundant pressure is applied to this input terminal. Separation line 23 represents that the application of redundant pressure to EBS wheel modulator 1 is effected externally; redundant pressure 10 is
3/2 solenoid valve provided here, which is generated in the vehicle brake valve of the vehicle and which opens when no current flows
Is output via and is connected to the first terminal 7 at atmospheric pressure.

The second terminal 8 is designed as a pneumatic air escape output terminal; this, as alluded to before, is the terminal 2 of the air escape solenoid valve 6 in this switching position.
Connected to 5.

The third terminal 9 of the redundant switching valve 4 is used as an output terminal or an input terminal depending on the switching position; in the electronic braking position, the third terminal 9 acts as an input terminal and escapes air. Due to its atmospheric coupling with the terminal 25 of the solenoid valve 6, an air escape of the control space of the relay valve 3 is caused.

In the second valve switching position, in the redundant position, the third terminal 9 acts as an output terminal, which is connected to the first terminal 7 at this time and thus joins the terminal 7. Redundant pressure 10 is the terminal 2 of the air release solenoid valve 6.
5 is transmitted.

The switching position of the redundant switching valve 4 is the first.
(7) and the pressure applied to the third (9) terminal: when the first terminal receives a pressure action, it occupies a redundant position [first valve switching position] via the pre-control section 11.
When pressure is applied to the third terminal 9, the electronic brake position [second valve switching position] is occupied via the front control unit 12. In the drawings, the front controller 11 is shown to be larger than the front controller 12. This implies that the working surface of the front control part 11 is formed larger than that of the front control part 12 and therefore occupies a redundant position when pressure is applied to both terminals 7 and 9. Is implied. In addition, this shows in a formulation that the electronic brake position is occupied only when no pressure is applied to the first terminal 7 and at least partially to the third terminal 9. . The meaning of at least a temporary pressure effect on the third terminal 9 will be explained further below.

In actual operation, when the EBS brake control is activated, the 3 /
Since the two solenoid valves 24 are supplied with current, no pressure is applied to the first input terminal 7 of the redundant switching valve 4. However, as soon as the 3/2 solenoid valve is returned to its spring-loaded basic position [eg due to a malfunction of the electronic device], the redundant pressure 10 is immediately applied to the first terminal 7 of the redundant switching valve 4 and the redundant switching is performed. The valve occupies a redundant position.

A sectional view of the redundant switching valve 4 in FIG.
It shows its structural construction: redundant pressure switching valve 4
Consists of a cylindrical member 13, which is screwed into a threaded blind hole in the EBS wheel modulator housing and which realizes the first terminal 7 and pressure. It has holes [configured as stepped holes] that extend from end to end for transfer. On the side of the cylindrical member facing away from the terminal 7,
A sliding surface 14 is provided, and on this sliding surface,
A valve switching member 15 having a hollow cylindrical side wall and formed as a hollow-shaped component is movably supported. The hollow cylindrical side wall of the valve switching member 15 is formed as a circulating sealing piece 16.

The valve switching element 15 is realized as a metal-reinforced elastomeric component [metal-reinforced part 3].
0]], which at the same time guarantees the requisite shape stability due to the elastic and pressure effects required for the sealing element.

In a perspective view of the valve switching member according to FIG. 4, it is shown that a centrally arranged circulating sealing ridge 17 is integrally formed at the bottom of the valve switching member 15 facing outwards. There is. In order to improve the sliding characteristics and prevent the inclination, the valve switching member 15 has a cylindrical outer surface,
Formed integrally are a plurality of nodal centering pieces 18 used as guide elements [at least three are required]. Preferably, three spacing elements 19 are integrally injection-moulded on the inner bottom of the valve switching element 15 in the direction of the valve switching element in the direction of the first terminal 7 according to FIG. Ensuring that a sufficient air space is formed between the cylindrical member 13 and the valve switching member 15 for the subsequent pressure action when moving the valve and that the valve switching member is not deformed by pressure loading. Guarantee. At least 1
It is necessary to note that one spacing element 19 is required, this spacing element being centrally mounted.

FIG. 2 shows the operation of the valve device when a redundant pressure is applied to the first input terminal 7 of the redundant switching valve 4: the valve switching member 15 is located behind the blind hole. Has been moved up to the interface 26, whereby the sealing ridge 17 seals the hole of the second terminal 8
No air escape is done.

Since the sealing piece 16 can be expanded to some extent,
The inner valve air space is vented and the air reaches via the third terminal 9 of the redundant switching valve 4 an air relief solenoid valve 6 which is open when no current flows.

At this time, the redundant pressure is due to the pressure action of the relay valve control piston provided here by the pressure passage 27 in the magnet of the air release solenoid valve 6, so that the relay valve is opened via the open valve seat (not shown). In the same manner as in No. 3, the control space (not shown) is connected. [The pressure action of the relay valve control piston (not shown) is such that the redundant valve "480 205
... corresponds to the pressure effect mentioned at the beginning of the switching piston at 0 "].

As mentioned above, in order to occupy the electronic brake position according to FIG. 3, it is first necessary that there is no pressure at the first terminal 7 of the redundant pressure switching valve 4. Similarly, as described above, the solenoid valves 5 and 6, ie the precontrol solenoid valve, are controlled in order to establish the brake control pressure. In this way, within the framework of this control pressure generation, the air-releasing solenoid valve 6 is first operated temporarily, and the air-releasing impact is carried out via the pressure passage 27 by each such operation. The air escape pressure shock causes the third terminal 9 to be at least temporarily pressurized.

During this first air relief pressure shock at the third input terminal 9, the ring surface outside the circulating ridge 17 at the outwardly facing bottom of the valve switching member 15 [FIG. 4]. 28 is under pressure. This causes the valve switching member 15 to move from its redundant position corresponding to FIG. 2 to its electronic braking position corresponding to FIG. 3; this valve switching member then once again receives the redundant pressure on the first input terminal 7. Stay in this position until you join.

Therefore, in the electronic braking position, the circulating sealing ridge 17 is lifted from the rear blind hole boundary surface 26, and the hole of the second terminal 8 is opened, so that the connection to the air escape portion 21 is performed. ing.

The above-mentioned working surface of the front control part 11 corresponds to the surface of the inner pot bottom 29 according to FIG. 4, and this surface is more than the working surface of the front control part 12, namely the ring surface 28. large.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a brake pressure modulator configured in the form of an EBS wheel modulator that includes redundant pressure switching valves.

FIG. 2 is a cross-sectional view of a portion of an EBS wheel modulator including an indication of a redundant pressure switching valve in a redundant position when EBS control is not activated.

FIG. 3 is a cross-sectional view of a portion of an EBS wheel modulator including a display of redundant pressure switching valves in an electronic brake position when EBS control is activated.

FIG. 4 is a perspective view of a valve switching member used as a valve switching element in a redundant pressure switching valve.

FIG. 5: Well-known WABCO device "Ei" already mentioned above
nfach-Redundanz 480 205 1
It is a sectional view of 040 ".

[Explanation of symbols]

1 EBS wheel modulator 2 Solenoid valve front control unit 3 relay valve 4 Redundant switching valve 5 Ventilation solenoid valve 6 Air relief solenoid valve 7 First terminal 8 Second terminal 9 Third terminal 10 Redundant pressure 11 Front controller 12 Front control unit 20 Pressure supply unit 21 Air release section 22 Brake pressure output terminal

Continued front page    (72) Inventor Werner Dreell             Federal Republic of Germany Garbsen-Lapsewe             Ark 1 (72) Inventor Bernd Kyle             Wunstorf Barnesi, Federal Republic of Germany             Utrase 40 (72) Inventor Heinz-Werner-König             Barsinghausen Be, Federal Republic of Germany             Unzenhof 5 (72) Inventor Hartmut Syaprell             Hannover Frobe, Federal Republic of Germany             Nius Vueke 12 F-term (reference) 3D046 BB01 CC03 HH16 LL22 LL26

Claims (9)

[Claims] 1. A) a first terminal is provided as an atmospheric pressure input terminal, to which a redundant pressure of an electronic pneumatic braking device can be applied; b) a second terminal as an atmospheric pressure air release output terminal. A terminal is provided; c) a third terminal is provided, which is formed as an atmospheric pressure input terminal and as an atmospheric pressure output terminal; d) a third terminal is electronically controlled atmospheric pressure Connected to an output terminal of a valve pre-control unit provided for forming a brake pressure; e) two valve switching positions are provided; f) a first valve switching position, a redundant position, Occupied when pressure is applied to the first terminal; g) the second valve switching position, the electronic brake position, when there is no pressure at the first terminal and at least temporarily at the third terminal. Occupies when adding: A switching valve device, in particular for an electronic pneumatic braking device. 2. The switching valve device according to claim 1, wherein a movable valve switching member is provided in a cylindrical member as the valve switching element. 3. A switching valve device according to claim 2, characterized in that the valve switching member is formed as a vase-shaped component with a circular bottom and a hollow cylindrical side wall. 4. The hollow cylindrical side wall of the valve switching member is formed as a circulating sealing piece.
The switching valve device according to claim 3. 5. The valve-switching member according to claim 3, characterized in that it has a centrally arranged ring-shaped sealing ridge on its outwardly facing bottom. Switching valve device. 6. The switching valve device according to claim 5, wherein at least three node-shaped centering pieces are provided on the cylindrical outer surface of the valve switching member. 7. A switching valve arrangement according to claim 6, characterized in that at least one spacing element is provided at the inner bottom of the valve switching member. 8. The valve switching member is realized as a metal-reinforced elastomeric component,
The switching valve device according to claim 1. 9. The switching valve device is structurally integrated with a brake pressure modulator provided for producing an electronically controlled pneumatic braking pressure. A switching valve device according to one of the items