DE2726465A1 - CENTRAL CONTROL FOR VEHICLES - Google Patents

Description

-e-? .726A65

State of the art

The invention is based on a central control according to the preamble of the main claim. Such a central control is known (DT-OS 1 928 620). In this known type, a lubricating oil pump is used to all hydraulic To supply systems on a motor vehicle with the same hydraulic pressure medium. The known control has the Disadvantage that if there is a leak in one system, the other systems soon suffer from a lack of pressure, and the risk of There is a failure of the entire facility.

Advantages of the invention

In the central control with the characterizing features of the main claim, it is advantageous that in the event of a leak in one system this can be shut off from the energy source and the other systems that are still intact can thus be secured are. If the leak causes only a small loss of pressure medium, it is also possible, e.g. with gaseous pressure medium, to keep pressure medium in the faulty pressure medium system and to be supplied in an increased amount. This is also the case when using electrical or electronic peeling agents advantageous, e.g. to monitor the important braking system with the help of a priority logic, so that the vehicle is on everyone Case retains its braking power.

Further advantages of the invention emerge from the description and the subclaims.

drawing

Several exemplary embodiments of the invention are shown in the drawing and explained in the description below. It show: Pig. I a first embodiment of a central controller, FIG. 2 shows a detail of the type according to the FIGS. 1 and 3 show another type of central control.

809851/0287

'ζ " F726A65

Description of the invention

In Fig. 1, a central control is shown, the several hydraulic or pneumatic systems are assigned. The systems are in detail: A hydraulic brake system, for example 1 with a central control 37 j further with a pedal-operated brake booster 2 and with two brake circuits I and ll; the supply of the braking system is from a 2/2-way valve 3 monitors;

a hydraulic actuating piston system 4 with an actuating cylinder 5 for driving a flap 6 or levers or the like; the supply of the setting piston system H is monitored by a 3/2-way valve 7;

a hydraulic power steering system 8 with a steering valve 9 with steering cylinder 9 ¹ »its own pressure accumulator 10, including pressure switch 11 and check valve 12; the supply of the steering system 8 is monitored by a 2/2-way valve 13;

a hydro-pneumatic suspension system lh with a suspension cylinder 15 and a double valve arrangement l6 for supplying and discharging energy into and out of the corresponding circuits I and II;

a hydraulic actuating system 17 with an actuating cylinder l8 to operate a switch 19

and finally a separation system 20 with a pump cylinder with a separate refill container 22 and a check valve 23; the pump piston is to increase the pressure under the pressure in the hydraulic central control, the relief of the actuating system 17 is controlled by a 2/2-way valve 24 supervised.

809851/0287

A fluid container 25 with a level switch 26 is provided on the brake booster 2. The central control also includes a pump 27 and a memory 28 as well as an electronic control unit 29, the electrical connecting lines 30, 31, 32 and 33 to the level switch 26, a pedal switch 34, a position switch 35 on the actuating cylinder and a position switch 36 on the suspension cylinder 15 Has. The hydraulic systems 1, 4, 8, 14, 17 and 20 work in a known manner and will not be described in more detail here. The systems 1, 4, 8 and 14 can be switched on and off by means of the multi-way valves 3 »7 _{5 13» 16, which can be actuated electrically or also by pressure medium.} In the case of the system 17, this is carried out directly by the central control 37, and in the case of the system 20, the multi-way valve 24 takes over the shutdown.

Each system is shut down if a leak or other fault occurs in the system. Various options for leak detection are shown in FIG. It is the refill container shown in FIG. 1 again 25 shown, and it can be seen that in the container not just one but several level switches 38, 39> 40 and 41 and three, separated by two partitions 42 and 43 Chambers 44, 45 and 46 are provided. The partition wall 43 is located between the two brake circuits I and II and is less high than the partition wall 42. The container 25 is on The brake booster 2 is attached and has a connecting line for each brake circuit I and II and a connecting line 47 to the pump 27.

With such a design, the leak detection works in a test program as follows:

If the switch 38 shows empty, a first warning is given, which should preferably work intermittently to prevent the To make the error clearer to the driver by means of a flashing warning lamp, e.g. when starting the car.

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ORIGINALJNSPECTED

3 3 "P

2726'46S

If the switch ^ l responds, the brake is defective. It takes place full warning.

When the switch 39 responds, a second or the same warning lamp flashes. It is a different consumer than the brake malfunction. It is also possible to carry out a test program without the switch 38.

When using the switch ² JO, which is preferably designed as a multiple level switch for all auxiliary consumers, the switch ^ l can be omitted. Then the test program runs as follows:

If the switch 38 shows empty, the individual auxiliary consumers are switched off one after the other, i.e. the pressure feed für.die secondary consumers are interrupted one after the other. For example, if one of the secondary consumers is switched on and if the level continues to drop, it can be seen that this secondary consumer has the leak sought.

A simplified solution to the last-mentioned embodiment is to give priority to the brakes and steering. if then the switch 38 responds, only the brake is switched on. If the test result is positive for the brake, then so the steering is then tested. If this test does not indicate a leak either, then the secondary consumers remain from that Energy supply switched off.

FIG. 3 shows a modification of the design according to FIG. 1, therefore the same reference numbers are used here for the same parts.

Here, however, a pressure switch 51 is also used as a pressure sensor and a 2/2-way solenoid valve 52, which is connected to the electronic control unit 29 is connected.

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Test sequence: If the switch 26 switches off as a result of falling levels in the container 25, this takes place via the central control 37 a blocking of the flow of energy to the central control via the solenoid valve 52 and from the pump 27 to the memory 28. The valve 7 is closed. If the test is positive, i.e. no pressure drop is measured, all the valves in the brake system are off tight. Then the next consumer, the hydraulic actuating piston system 4, is switched on via the valve 7. If no leak can be found there either, the system 4 is switched off again. That way, all of them become secondary consumers tested until the leak that is to blame for the drop in level is found.

The test logic can be influenced, for example, by a speed signal from the vehicle, in which case the brake test only at a standstill has the advantage that in such a case the full brake pressure can be applied. To this end is also the use of an additional accelerator pedal signal is conceivable. It is also possible to use compressed air systems for leak detection to use pneumatic pressure sensors.

It is conceivable that the level and / or the pressure sensor a have linear measured value acquisition or measured value evaluation. However, it is also possible to record or evaluate the measured values in stages.

809851/0287

Claims (13)

R. 39 · ■■■?
2.5.1977 He / Thu Robert Bosch GmbH, Stuttgart Expectations "1.1 Central control for vehicles, especially motor vehicles, Jit a central energy source for at least two different, Pressure medium systems equipped with consumers, characterized in that pressure medium or electrically controlled Valves (3j7> 13> l6,24,5,2,) are used over which after an actuating command to the corresponding pressure medium system (1,4,8, 14,17,20) with his (n) consumer) energy can be supplied or the energy source (27) can be shut off from this pressure medium system (1, 4, 8, 13, 17, 20). 2. Central control according to claim 1, characterized in that the control command from an electronic control device (29) can be created. 3. Central control according to claim 1 or 2, characterized in that that electrical or electronic switching means are used in a hydraulic central control (37), with which the faulty system can be separated from the other systems in the event of a leak in one of the pressure medium systems or can be switched off. 809851/0287 ORIGINAL INSPECTED "> ο * t 4. Central control according to claim 3, characterized in that the electronic switching means assigned a priority logic is. 5 · Central control according to one of claims 1 to 4, characterized characterized in that directly or indirectly acting sensors are used for leak detection. 6. Central control according to one of claims 1 to 5, characterized in that hydraulic is used as the pressure medium. 7. Central control according to one of claims 1 to 5, characterized in that the pressure medium is a gaseous pressure medium is used. 8. Central control according to claim 6, characterized in that level sensors (switches 26,38,39,40, Ui) are used for leak detection. 9. Central controller according to claim 6, characterized in that for Lecksensierung a combination of level sensors (switch 26,38,39j4O, 4l) and Druckfühlerc is used (51) (Fig. 3). 10. Central control according to claim 7, characterized in that (51) that pneumatic pressure sensors are used for leak detection 80985 1 / Π 2 8 7 11. Central control according to one of claims 8 to 10, characterized in that the level and / or pressure sensor have a linear recording or evaluation of measured values. 12. Central control according to one of claims 8 to 10, characterized in that the level and / or pressure sensor have a graded acquisition or evaluation of measured values. 13. Central control according to one of claims 8 to 12, characterized in that a warning lamp is used which can be controlled intermittently if the components which have an insignificant influence on the safety of the vehicle fail. 809851/0287