DE4227084A1 - Pressure control module for a brake system, especially for commercial vehicles - Google Patents

Description

State of the art

The invention is based on a pressure control module according to the Oberbe handle of claim 1.

Such a pressure control module is known from EP-A 0 467 112, in which an electronic braking system for road vehicles with a for the control of brake pressure modulators electronics is described, which is assigned in several to the individual wheels, with at least one microcomputer provided wheel modules and in at least one superordinate provided with a microcomputer Central module is divided, indicating the possibility combine two wheel modules of one axle into one axle module.

An electronic braking system for road and rail vehicles of the type described above, its wheel-related actuators are provided with their own control electronics and which, starting from centrally arranged electronics, via interfaces be coordinated and also through these interfaces Being able to exchange data is in principle suitable, the demands to meet a modern, electronic braking system. It has  however, demonstrated that the additional cost of such a system of a conventional brake system through the actually achievable functional advantages can not be weighed.

Object of the invention

The object of the invention is based on the prior art based on specifying a pressure control module, its use opposite the well-known bike-related concept by reducing the number of required system components a significant reduction in Manufacturing costs allowed and at the same time system security improved.

Advantages of the invention

A generic pressure control module with the according to the invention realized features of the characterizing part of claim 1 offers the particular advantage that with only one electronics unit individual pressure control at two separate outputs or for two separate brake cylinders or pairs of brake cylinders realized can be. Furthermore, in an embodiment of the invention Possibility of at least one of the solenoid valves for the pressure control at both outputs of the valve unit.

The measures listed in the subclaims provide for partial further training and improvements in the main claim specified air brake system possible.

The configuration of the invention is particularly advantageous Pressure control module according to claim 2, where two pressure control channels a common changeover valve designed as a 3/2 solenoid valve assigned.  

The pressure control module with the features also offers particular advantages of claim 3, according to which a further, two pressure control channels common switching valve in case of failure of the electrical or electronic control how the pressure control module works with a conventional, pneumatic brake system.

Further advantages of the printing module according to the invention in its ver different configurations mentioned above result in that with its help without additional valve devices an "electronic differential lock" can be realized. Furthermore, the pressure control module according to the invention offers the advantage that even when switched off or failed, electronic Brake system is still a fully effective, conventional, pneumatic Brake system is available.

drawing

The invention is illustrated below with the aid of preferred embodiments games explained in more detail in connection with a drawing. It demonstrate:

Fig. 1 shows a first preferred embodiment of a 2-channel pressure control module according to the invention;

Fig. 2, 2a and 3 further preferred embodiments of 2-channel pressure regulator modules according to the invention;

Fig. 4 is a highly schematic representation of a vehicle brake system, which is constructed using pressure control modules according to Fig. 1 or 2 or 2a; and

Fig. 5 is also a highly schematic representation of essential parts of a vehicle brake system constructed using a pressure control module according to the invention.

Description of the embodiments

In particular, FIG. 1 shows a pressure control module 100 which is in accordance with the invention designed as a 2-channel pressure regulator module and includes a valve unit 1, and a so mechanically and electrically directly connected electronic unit 2.

The valve unit 1 has two separate pressure control channels, each of which comprises a separate relay valve 3 or 4 . The pneumatic control input 5 of the relay valve 3 is monitored by a relay valve 3 individually assigned 2/2 solenoid valve 7 . The pneumatic control input 6 of the relay valve 4 is monitored by a further 2/2 solenoid valve 8 which is individually assigned to this relay valve.

The two 2/2-way solenoid valves 7 , 8 are jointly connected upstream of a changeover valve in the form of a 3/2-way solenoid valve 9 , which, as will be described in more detail below, the ventilation of the relay valves 3 , 4 or the brake cylinders connected to them (not shown) via an outside air connection 10 , 11 .

The 3/2-solenoid valve 9 serving for ventilation is preceded by a further 3/2-solenoid valve 12 as a changeover valve, which is just assigned to both pressure control channels together. In its spring-operated basic position shown in FIG. 1 or in its de-energized state, the further 3/2-manget valve 12 connects a connection 13 of the pressure control module 100 , to which a control pressure is applied via lines 14 and 15 and the 3/2-solenoid valve 9 and each of the 2/2 solenoid valves 7 , 8 with the control inputs 5 , 6 of the relay valves 3 and 4 . In the current-charged state, ie when the excitation winding is activated, the further 3/2 solenoid valve 12 connects a connection 17 via lines 16 , 15 to the inlet side of the 3/2 solenoid valve 9 , so that a supply pressure at connection 17 via the solenoid valves 7 , 8 can be placed on the pneumatic control inputs 5 , 6 of the relay valves 3 , 4 .

Each of the two relay valves 3 , 4 has its own Arbeitsan circuit 18 and 19 , which branches into two connections 20 , 22 and 21 , 23 , respectively. Each connection 20 , 22 or 21 , 23 leads to a brake cylinder, not shown, of a vehicle wheel. To monitor the working connections 18 , 19 , as indicated by dashed lines, a pressure transmitter 24 or 25 can optionally be connected to these connections 18 , 19 , the two pressure transmitters 24 , 25 being electrically connected directly to the electronics unit 12 .

The electronics unit 2 comprises at least one microcomputer, which has its own intelligence, as well as further electronic or electrical components, which are not described here in greater detail, which are supplied with a supply voltage UB via a connection 26 and are capable of receiving incoming analog and digital signals to process and exchange information with at least one further electronic system unit via at least one interface and to issue control commands and signals to at least one further electronic or electrical unit, in particular to the valves 7 , 8 , 9 , 12 of the valve unit 1 according to FIG. 1 or to the valves of the modified valve units according to FIGS. 2, 2a and 3.

For this purpose, the electronics unit 2 has interface connections 27 , connections 28 for transmitting and receiving analog and / or digital signals and connections 29 corresponding to the number of sensed vehicle wheels for the wheel turning behavior, reproducing sensor input signals.

The 2-channel pressure control module 100 according to FIG. 1 can be used in different ways both in an electronic and in a conventional brake system and works as follows:

When the brake value transmitter 33 is not actuated (see FIG. 4) - one of the brake value transmitters of this type is described, for example, in an earlier, unpublished application by the applicant (German patent application P 41 41 995.2) - all the magnetically actuatable valve units 7 , 8 are located . 9 , 12 in the state shown in FIG. 1, ie in their spring-actuated basic position. As soon as the tread plate of the brake valve or the brake value transmitter 33 is actuated, the current position of the tread plate is in the form of an electrical signal generated, for example with the aid of a potentiometer, possibly via an electronic system unit - in the exemplary embodiment according to FIG. 4, a central control device 34 - Placed on the interface connections 27 of the pressure control module 100 , the electronics unit 2 of which then generates corresponding electrical signals which result in the 3/2 solenoid valve 12 switching into its working position immediately upon the first, measurable movement of the tread plate of the brake value transmitter 33 . Furthermore, depending on the size of the output signal of the brake value transmitter 33, the electronic unit 2 generates corresponding output signals for the two 2/2 solenoid valves 7 and 8 , which in the exemplary embodiment according to FIG. 1 can be so-called high-cycle valves, for example, and the pneumatic control inputs 5 , 6 of the two relay valves 3 , 4 control accordingly, so that the brake cylinder pressure at the working connections 18 , 19 is "clocked up" according to the position of the tread plate of the brake value transmitter 33 . If the pressure at the working connections 18 , 19 is monitored by the pressure transmitters 24 and 25 shown in broken lines in FIG. 1, a closed pressure control circuit is obtained for monitoring the brake cylinder pressure.

The pressure reduction - releasing the brake - takes place when the tread plate of the brake value transmitter 33 is released for both pressure channels by actuating the 3/2-solenoid valve 9 by the electronics unit 2 in such a way that the solenoid valve 9 moves from its spring-actuated basic position into its solenoid-operated working position while, at the same time, the outside air connection 10 , 11 is connected to the pneumatic control inputs 5 , 6 of the relay valves 3 and 4 , respectively, via the 2/2-way solenoid valves 7 , 8 , which are in their basic position again at this time, whereby the control chamber of the relay valves 3 , 4 is vented, with the result that the respectively connected brake cylinder (not shown) is vented via their reaction chambers.

Also in the event that the brake system works in ABS (anti-lock protection) mode or in ASR (traction control system) mode, the pressure is reduced via the 3/2 solenoid valve 9 , while the holding function and Pressure build-up function can be realized again via the two 2/2 solenoid valves 7 , 8 . It is by a phase-shifted control of these two 2/2-way solenoid valves 7 , 8 easily possible to generate different braking pressures both in the pressure build-up and in the pressure reduction in the two regulated pressure channels.

In the embodiment shown in Fig. 1 embodiment, the valve unit 1, however, it is not possible in the pressure channel to the brake pressure, ie the pressure at the respective work port 18 and build 19 to a pressure channel and to remove these same for the other pressure channel. If such a mode of operation of the brake system is desired or required, then in designing the invention according to FIG. 2 there is the possibility, with the same structure of the valve unit 1, in addition to provide a further 3/2 solenoid valve 9 'as a vent valve and the relay valve 3 to vent via this separate outside air connection 10 ', 11 '. In the valve unit 1 of the embodiment shown in FIG. 2, a separate 3/2 solenoid valve 9 , 9 'and a separate external air connection 10 , 10 ', 11 , 11 'are provided for each relay valve 3 , 4 .

A further variant of the valve unit 1 , which also offers the possibility of simultaneously building up the braking or working pressure in one pressure channel and reducing it in the other pressure channel, is shown in FIG. 2a, according to which the two 3/2 solenoid valves 9 , 9 'are each replaced by a proportional valve 30 , 30 ', the valve unit 1 being constructed in the same way as the valve unit 1 in Fig. 2nd

In the variant according to FIG. 2a, the monitoring of the relay valves 3 , 4 takes place via a proportional valve 30 , 30 ', which as a pilot valve assigns a control pressure to the respectively assigned relay valve 3 , 4 , which is predetermined by a one generated by the electronics unit 2 Control current is directly proportional. In the pressure control module 100 according to the invention shown in FIG. 3 of the drawing, the additional 3/2 solenoid valve 12 provided there is omitted in the valve unit 1 , which is otherwise constructed in the same way as the valve unit 1 of the exemplary embodiment according to FIG. 1 that in this variant on the inlet side of the 3/2-solenoid valve 9 always only the control pressure from port 13 comes, while the supply pressure from port 17 is constantly available directly to the two relay valves 3 , 4 , as is also the case with the Variants according to FIGS. 1, 2 and 2a is the case.

The application of the embodiment according to Fig. 3 is preferably provided for conventional braked trailer vehicles, in which an ABS function has to be realized.

For vehicles with drive axles, however, an ASR function (traction control system) is often required in addition to the ABS function. Regardless of whether this drive axis is conventionally or electronically braked, such an ASR function can be implemented in the simplest way with the valve unit 1 according to FIG. 1 with the aid of the 3/2 solenoid valve 12 present in this variant. As soon as the electronics unit 1 detects different wheel speeds on the drive axle while driving, which cannot be traced back to a difference in wheel speeds caused by cornering, this is interpreted as undesirable slip, whereupon the electronics unit 2 switches the 3/2-way solenoid valve 12 and via the corresponding 2/2-solenoid valve 7 or 8 increases the braking pressure for the faster rotating wheel until both drive wheels have approximately the same wheel speed or speed. The build-up of a corresponding brake pressure for the brake cylinder of the slower rotating wheel is prevented by locking the 2/2 solenoid valve 7 and 8 assigned to this wheel; the corresponding 2/2-way solenoid valve 7 or 8 is therefore not clocked by the electronics unit 2 , but is controlled such that it supplies the compressed air to the pneumatic control input 5 or 6 of the relay valve 3 or 4 in question . The solenoid valve 12 is decisive for the traction control or for achieving an electronic differential lock insofar as when the drive wheels are spinning, especially when starting off, the brake value transmitter 33 is normally not actuated and consequently no control pressure is available at the connection 13 stands.

If, in the event of a fault, the 3/2-solenoid valve 12 can no longer be electrically controlled, ie brought into its switched-on position, the full braking effect can still be achieved via the line connection 13 , 14 , 15 which is open when the valve is not actuated (back-up -Function). In this case, too, the full ABS function of the brake system is retained.

Fig. 4 of the drawing illustrates the use of two pressure control modules 100 , 100 'according to the invention in a complete braking system based on a highly schematic representation. It can be seen that the brake value transmitter 33 has, in addition to its electrical part 33 a, two pneumatic parts 33 b, 33 c and a pressure relief point 33 d. The brake cylinders 40 , 41 , 42 , 43 for the four wheels of the vehicle can be pneumatically controlled in the usual way via the two pneumatic parts 33 b, 33 c. The electrical part 33 a of the brake value transmitter 33 supplies electrical signals, which correspond to the position of the tread plate 33 e, to a central control device 34 , which controls the two pressure control modules 100 , 100 'via corresponding bus lines, which in the manner described above at brake system operating as an electronic brake system take control of the associated brake cylinders 40 , 41 , 42 , 43 .

In FIG. 5, the possibility of using a pressure control module 100 according to FIG. 3 for a three-axle trailer vehicle with a conventional brake system is shown on the basis of a likewise highly schematic Dar position.

With regard to the function of the pressure control module 100 according to FIG. 3 explained above, only one ABS function is possible in the application under consideration. The various solenoid valves 7 , 8 , 9 of the valve unit 1 of the pressure control module 100 are activated in the manner already explained above. Here, in this application, four wheel sensors in the form of speed sensors connected to the pressure control module 100 101, whose output signals are processed by the pressure control module 100 individually, for example the art that due to the speed signals of two wheels which are preferably arranged page by page, an individual pressure control for the brake cylinder 102 in question takes place, in particular on the principle that the speed of the slower rotating wheel is function-determining. Additional central electronics or, generally speaking, another electronic system unit is not required in this case.

Even in the case of using an electronic brake system in a trailer vehicle, no additional central electronics is required except for the variants of a pressure control module according to the invention according to FIG. 1 or 2, since the 2-channel pressure control module provides the information from the towing vehicle directly via its own interface (if necessary . multiple interfaces) can be received and processed internally. Also other signal values, such as. B. the output signals of a load transmitter 35 can be received and processed directly to generate the braking force suitable for the individual case.

From the above description it is clear that considerable advantages can be achieved with the pressure control module according to the invention compared to the prior art. One of these advantages is first of all that one solenoid valve - for example in the embodiment according to FIG. 2 - or two solenoid valves - in the embodiment according to FIG. 1 - can be saved. Above all, however, when using a pressure control module according to the invention, there is the advantage that, in particular compared to the prior art according to EP-A 0 467 112 A2, a wheel module electronics can be saved almost completely. In addition, there are significant savings in electrical and pneumatic lines and line connectors, such as plug components, fittings and the like. Finally, according to the invention, there is also a higher level of security, since less fault-prone assemblies and connecting elements are used.

Claims (8)

1. Pressure control module for a compressed air brake system, in particular for commercial vehicles, with a solenoid valve for the control of at least one relay valve valve unit and with an electronic unit with a microcomputer, which can be connected in particular to at least one further electronic system unit for the exchange of electrical signals, thereby marked that the valve unit ( 1 ) has two channels, each with a relay valve ( 3 , 4 ) per channel and equipped with only one, the control of both relay valves ( 3 , 4 ) serving electronics unit ( 2 ) and at least for the control of the brake cylinder a vehicle axle is provided. 2. Pressure control module according to claim 1, characterized in that each of the two relay valves ( 3 , 4 ) of the valve unit ( 1 ) is assigned a control solenoid valve ( 7 , 8 ) on the aisle side and that the two control solenoid valves ( 7 , 8 ) on the input side together a 3/2 solenoid valve ( 9 ) serving as a vent valve for establishing an outside air connection ( 10 , 11 ) is connected upstream. 3. Pressure control module according to claim 1, characterized in that each of the two relay valves ( 3 , 4 ) of the valve unit ( 1 ) is assigned a control solenoid valve ( 7 , 8 ) on the aisle side and that each of the two control solenoid valves ( 7 , 8 ) on the input side in each case a 3/2 solenoid valve ( 9 , 9 ') serving as a vent valve for producing an outside air connection ( 10 , 11 , 10 ', 11 '). 4. Pressure control module according to claim 1, characterized in that each relay valve ( 3 , 4 ) by a proportional valve ( 30 , 30 ') can be controlled. 5. Pressure control module according to claim 2, 3 or 4, characterized in that a further 3/2-solenoid valve ( 12 ) is provided, through which to supply valve means provided downstream ( 7 , 8 , 9 ) of the valve unit ( 1 ) with a pneumatic pressure in a spring-loaded basic position, a control line ( 14 , 15 ) serving the conventional pneumatic braking operation, in which a control pressure can be transmitted, or a line ( 16 ) charged with a supply pressure can be released in a solenoid-operated working position. 6. Pressure control module according to one of claims 1 to 5, characterized in that the pressure at each of the working connections ( 18 , 19 ) with the aid of an electrically connected to the electronics unit ( 2 ) pressure sensor ( 24 , 25 ) can be detected. 7. Pressure control module according to one of claims 1 to 6, characterized in that the electronic unit ( 2 ) is designed such that up to four wheel speeds can be individually evaluated with their help for controlling the pressures at the two separate work connections ( 18 , 19 ) . 8. Pressure control module according to one of claims 1 to 7, characterized in that the electronic unit ( 2 ) is designed such that with its help to control or regulate the pressures at the two separate work connections ( 18 , 19 ) the output signals of further external Signal transmitters can be evaluated.