DE10332669A1 - Braking and traction system for motor vehicles, especially all-wheel drive vehicles, wherein axle or wheel switching systems are controlled hydraulically using the braking system hydraulics - Google Patents

Abstract

Braking and traction system for motor vehicles, especially motor vehicles with all-wheel drive systems, whereby one or more axle or wheel switching systems (5, 6) are provided that can be controlled hydraulically by the braking system hydraulics.

Description

The The invention relates to a braking and traction system for motor vehicles, especially for motor vehicles with four-wheel drive, according to the generic term of Claim 1.

In Modern four-wheel drive vehicles are known to use brake engagement and traction control systems. Modern vehicles are characterized by the fact that these systems are controllable and lead to a drive torque distribution. This controlled intervention takes place in passive mechanical systems, for example with visco-couplings, or with electrically adjustable differential locks or connection devices.

Farther All-wheel control systems are known in which the blocking effect by active brake application, i. by slowing down the spinning wheel is achieved.

One However, pure brake application disadvantageously has the effect of unnecessary energy get lost. Furthermore The handling is perceived by the driver as uncomfortable.

Farther be electronically controlled differential locks or Achszuschaltsysteme used here as a targeted control of the drive torque distribution can be done. Disadvantage of these systems is that in addition to the electronic Input signals also energy in electrical and hydraulic form necessary to control these controllable systems.

From the DE 40 14 863 A1 For example, a system for controlling torque transmission in a four-wheel drive vehicle is known in which wheel slip is regulated in the manner described.

From the DE 40 29 793 C2 a hydraulic vehicle brake system is known in which in a system of hydraulic brake lines, a plurality of valves is arranged, which are each separately controllable. This system is considerably expensive.

From the EP 0 736 431 B1 For example, there is known an antislip fluid pressure control device with a hydraulic device used in automobiles. Here, a plurality of valves is also provided, as in the second-mentioned document from the prior art.

Of the Invention is therefore the object of a braking and traction system for motor vehicles, especially for Motor vehicles with four-wheel drive, to improve that The traction control apparatus is simpler and more effective.

The asked task is in a braking and traction system of the generic type according to the invention the characterizing features of claim 1 solved.

Further advantageous embodiments of the method according to the invention are in the dependent claims specified.

core The invention here is that one or more axle or Radzuschaltsysteme are provided, which hydraulically from the hydraulic pressure reservoir the braking unit can be controlled.

The hydraulic brake unit thus takes over this function and must be extended accordingly. This is done a concentration of functionalities on the brake unit. A separate power supply for the switching systems are eliminated. Further the system becomes compact and inexpensive in production.

In further inventive embodiment is provided that said axle or Radzuschaltsysteme hydraulically controllable differential locks are. Here are now in particular the differential locks in all-wheel drive in this way efficiently controlled.

In further advantageous embodiment is indicated that the said Achs- or Radzuschaltsysteme and / or differential locks via input signals a likewise the wheel brakes actuated control device are controllable.

Farther is advantageously configured that the control device functional the brake and the traction control signals in a common Processing run processed.

In Advantageous embodiment is specified that the control device with a plurality of sensors is connected by data technology, in such a way that both braking and blocking signals as well as traction slip signals equally and are processable in the same control device.

Furthermore, it is advantageously configured that the hydraulic unit for the purpose of loading the brake systems and the axle or Radzuschaltsysteme and the differential locks is applied accordingly to a higher power delivery.

In Another advantageous embodiment is specified that the control device is operable so that with the supplied sensor signals the current traffic situation can be assessed in a forward-looking manner and the axle or Radzuschaltsysteme and possibly the differential locks with control technology Assumption in traffic situation foresight are controllable.

Next the apparatus realization of the invention is also possible the various embodiments according to claims 2 to 7 functionally as digitized measures to drop off, i. as a software program product with the functions one of the claims 1 to 7, in which the mechanical and mechatronic control functions on a disk or are stored in a data file, which in the control device importable according to one of the preceding claims, or from the same is exportable.

In particularly advantageous embodiment of the invention is in handling with the software program product provided that the functions after one of the claims 1 to 7, the said mechanical and mechatronic functions stored on a data file retrievable via data network, which can be imported into the control device according to one of the preceding claims, or is exportable from the same.

The The invention is illustrated in the drawing and described in more detail below.

It shows:

1 a simplified schematic representation of an embodiment of the invention, and

2 : an overview of the aggregates.

1 shows an overview of a modern electro-hydraulic brake a motor vehicle, in which the invention is used. The pedal arrangement, as well as the controlled with the pedal servo or amplifier elements are here symbolically summarized to the position number 10 ,

From there, a Betäitgungssignal is given. Down to the item numbers 20 are the 4 pressure amplifiers to operate each wheel 30 driven. However, these are not only the actuation signal of the pedals 10 controlled, but on the booster also takes an electrical influence, for example, in the anti-skid control and in the suspension control.

However, these elements correspond to the prior art and therefore will not be further elaborated here. The pressure medium system of the brake system also includes a pressure medium reservoir 1 , which is fed by the hydraulic pump or a pumping system and supplied with pressure medium. Starting from this now not only the pressure intensifier in accordance with the invention 20 supplied for direct control of the braking means 30 but, at the same time, the same pressure medium system is used for the axle and wheel switch systems 6 and 7 fed.

About the pressure booster 4 and 5 become two differential locks 6 and 7 driven. The control is carried out via the E / P converter 2 and 3 , which convert electrical signals into pressure signals, and thus the application of the differential locks 6 and 7 influence.

As mentioned above this be switchable or ad hoc switchable differential locks. Important Here is that they have the same pressure medium system of the same pressure medium system be supplied. This eliminates additional pressure medium generating elements.

Important is, of course, that the pressure medium system, in this case the hydraulic pressure medium system of the brake unit can be extended and adjusted by this function got to. For the higher one Need for pressure medium now also said unit has been designed become. That the pumps, and the cable cross sections must be at the higher Need to be adjusted.

In addition to the usually 4 hydraulic outputs for the individual wheel brakes 30 Now a number of additional hydraulic outputs are integrated.

Furthermore receives the hydraulic unit in addition Input signals for controlling these differential locks. Accordingly, that must hydraulic system be designed in the manner described above to the higher one Demand for pressure medium, i. the higher demand for hydraulic Energy to be fair.

It is assumed that the activation of a differential lock, or the connection of an axle occurs only in temporary extreme situations, such as driving on ice or smoothness, or off-road, or in aggressive cornering. However, in ever the situation to have all safety reserves, the hydraulic system must be applied to this inventively higher demand for hydraulic energy.

By the use and expansion of the braking unit as an energy supplier and driving system for Four-wheel components can Vehicle Traction and Stability Features be concentrated on the brake unit. The hydraulic lines can be similar or identical to the brake lines to be installed in the vehicle and being repaired.

The Differential locks or the Zuschaltsysteme can be relatively simple and known hydraulic slats / coupling or locking systems reduced become.

The Differential locks or the connection systems can also be preventive, i.e. be activated before the occurrence of slippage, e.g. by means of a Situational awareness. In this case, sensors are provided, the Fahrzustän de and Record and evaluate environmental parameters, and within one If necessary, evaluate the evaluation unit for traction support.

The Differential locks can thus also proactive, i. before the occurrence of slip the driving dynamics influence positively.

2 shows an overview of the control technology side without the indicated hydraulic control circuits. In the central evaluation unit 40 all signals come together from which the traction and braking and chassis control is calculated or calculated. At the output of the evaluation unit 40 Then the respective wheel-related brake signals are output, and also also the traction control for the control of the two differential locks C1 and C2 shown here or 6 and 7 ,

in this connection It becomes clear that not just a summary on a common hydraulic energy source is beneficial, but that here also summarizes the electronic evaluation.

Depending on the number of clutches or differential locks to be controlled, the evaluation unit designed as an ABS / ESP control unit must be used 40 be supplemented by the appropriate number of hydraulic control loops.

The to be controlled four-wheel drive control components, i. Clutches and differential locks, have to be designed so that they possibly electronically regulated but can be controlled hydraulically and with the system pressures and oil volumes customary for brakes on actuation function.

The Activation takes place as in the wheel brake, e.g. in traction mode. When occurring and expected slip this is based on the control unit detected by speeds and vehicle parameters and depending on the situation by intervention in the wheel brake and / or the four-wheel system, a correction or a countermeasure initiated, so either wheel decelerate or differential lock activate.

In the example mentioned according 1 and 2 The ABS system has been extended by 2 hydraulic control circuits to activate one center and one rear axle lock each. Alternatively, however, active rear axle differentials for braking or even accelerating individual wheels can be controlled.

All in all arise from the inventive design the pressure medium requirement a set of advantages.

So A concentration of functions traction, vehicle stability takes place on the Brake unit and its hydraulic power generation.

Farther there is an elimination of separate control elements / energy supply for the All-wheel components.

In addition, will a weight reduction through the use of said central Hydraulic unit achieved, the so equipped vehicle significantly makes it easier without loss in functionality.

1

Pressure fluid reservoir

2

I / P converter

3

I / P converter

4

booster

5

booster

6

limited slip differential

7

limited slip differential

10

Bremspedalerie

20

booster

30

brakes

40

evaluation

Claims (9)

Braking and traction system for motor vehicles, in particular for motor vehicles with four-wheel drive, characterized in that one or more axle or Radzuschaltsysteme ( 5 . 6 ) are provided which hydraulically from the hydraulic pressure fluid system ( 1 ) of the brake unit are controllable. Braking and traction system according to claim 1, characterized in that said axle or Radzuschaltsysteme ( 5 . 6 ) are hydraulically controllable differential locks (C1, C2). Braking and traction system according to claim 1 or 2, characterized in that the said axle or Radzuschaltsysteme ( 5 . 6 ) and / or differential locks (C1, C2) can be controlled via input signals of a likewise the wheel brakes actuated control device. Braking and traction system according to one of the preceding Claims, characterized in that the control means functionally the Braking and traction control signals in a common processing run processed. Braking and traction system according to one of the preceding Claims, characterized in that the control means comprises a plurality of Sensors, so that both braking and and blocking signals as well as traction slip signals alike and can be processed in the same control device. Braking and traction system according to one of the preceding claims, characterized in that the hydraulic unit for the purpose of loading the brake systems and the axle or Radzuschaltsysteme ( 5 . 6 ) and the differential locks is applied accordingly to a higher power delivery. Braking and traction system according to one of the preceding claims, characterized in that the control device is operable in such a way that the current traffic situation can be assessed in a predictive manner with the sensor signals fed in and the axle or wheel systems ( 5 . 6 ) and, if necessary, the differential locks with control technical Vorhalt in Verkehrssitua tionmäßig foresight can be controlled. Software program product with the functions after one the claims 1 to 6, in which the mechanical and mechatronic functions on a disk or are stored in a data file, which in the control device according to one of the preceding claims importable, or off the same is exportable. Software program product with the functions after one the claims 1 to 7, in which the mechanical and mechatronic functions stored on a data file retrievable via data network, which can be imported into the control device according to one of the preceding claims, or is exportable from the same.