DE102011017436A1 - Actuating device for a vehicle brake system - Google Patents

Abstract

The invention relates to an actuating device for a vehicle brake system, with a first piston-cylinder unit, the at least one working space of which is to be connected to at least one wheel brake of the vehicle via at least one hydraulic line, furthermore with an electro-mechanical drive device and an actuation device, in particular a brake pedal. According to the invention, a sensor device (31) is provided which is at least partially arranged in the area of the piston-cylinder unit (13).

Description

The invention relates to an actuating device for a vehicle brake system.

State of the art

• • Fehlersicherheit
• • Kosten und Gewicht
• • Funktionalität ABS/ESP und für alle Assistenzfunktionen
• • Baugröße und Baulänge

The trend of future brake force and control systems is to integrate all functions into one unit. In the foreground are:

• • Failure safety
• • Cost and weight
• • Functionality ABS / ESP and for all assistance functions
• • Size and length

An important component that determines the size and cost are the sensors. The above-mentioned systems generally require at least sensors for pedal travel, motor rotation angle, pressure, brake fluid level and possibly also piston position. The signals from these sensors must be supplied to an electronic control unit (ECU). A connection with wiring harness and plug is complex and reduces the reliability. The size is mainly determined by pedal interface, actuator and tandem master cylinder (THZ).

In Pedalinterface Wegsimulatoren are often used, as in the DE 10 2008 063 771 the applicant or auxiliary piston in as in the DE 10 2010 045 617.9 The applicant is described (to which reference is hereby made), which determine the length very much. In addition, the pedal stroke with a factor of 3.5 very much determines the overall length. Also the sensors, preferably to a module ( DE 10 2010 045 617.9 ), determine the size when housed in the pedal interface.

Future vehicle concepts require short dimensions both in the footwell (pedal interface) and in the engine or engine compartment (actuator + THZ).

Object of the invention

The invention has for its object to reduce the cost of sensors and electrical connection and to optimize the overall length of the integrated unit.

Solution of the task

The solution of this object is achieved according to the invention, characterized in that a sensor device is provided, which is arranged at least partially in the region of the piston-cylinder unit. With the solution according to the invention an actuating device for a motor vehicle brake system is created, which offers significant advantages over the known solutions in terms of structural conditions in terms of cost.

Advantageous embodiments or embodiments of the invention will become apparent from the other claims, to which reference is made here.

The cost of the sensors, starting from the summary of the sensors on a circuit board in DE 10 2010 045 617.9 for angle and pedal travel sensors, can be reduced by extending to more and ultimately all the sensors needed for the braking system. These are the brake fluid level sensor, an additional position sensor for the piston position and the integration of the brake light switch. This is nowadays used redundantly for the pressure signal ESP, since the brake signal is used fail-safe by many motor, gearbox and assistance functions.

Today, these sensors have a separate wiring harness to the corresponding ECU. Advantageously, all cable sets are replaced by direct connection via a plug connection from the sensor module to the ECU. The ECU itself then has only one wiring harness for the power supply and the onboard power supply control unit. This also simpler installation is connected.

• 1. Verlagerung des Sensormoduls vom Pedalinterface zum THZ oder Aktuator mit entsprechenden Betätigungselementen durch den Motor.
• 2. Entfernung aller Komponenten wie Stufenkolben und Wegsimulator vom Pedalinterface. Damit ist der Abstand von Aktuator zur Pedalplatte nur noch gleich dem Pedalhub.
• 3. Reduzierung des Pedalhubs durch Vergrößerung der Pedalübersetzung.

A reduction in the overall length of the integrated structural unit is achieved according to advantageous embodiments of the invention by:

• 1. Displacement of the sensor module from the pedal interface to the THZ or actuator with corresponding actuators by the motor.
• 2. Removal of all components such as stepped piston and travel simulator from the pedal interface. Thus, the distance from the actuator to the pedal plate is only equal to the pedal stroke.
• 3. Reduction of the pedal stroke by increasing the pedal ratio.

Embodiments of the invention and their embodiments are illustrated in the drawings and described in more detail below.

Description of the figures

Show it:

1 a structure of the actuator DE 10 2010 045 617.9 with displacement of the sensor module to the THZ, with direct electrical connection to the ECU;

2 a length optimized interface with displacement of the auxiliary piston to the THZ, also with displaced sensor module;

2a the arrangement of the sensor module of the HCU and ECU parallel to the actuator;

3 a section through the stator with position of the sensor shaft and actuators;

4 a section of the power transmission from the pedal to the actuator with over force protection; and

5 - 5a various circuits with integration of the brake light switch.

In the 1 illustrated actuating device for a motor vehicle brake has a brake pedal 1 with pedal ram 2 on. The pedal ram 2 acts via a preloaded elastic member 33a and flange sleeve 33 with an (auxiliary) piston 4 together, which is arranged axially displaceably in a cylinder and forms a working space, which with a travel simulator 17 connected is. The piston 4 has a central extension which is sealed in a partition wall of the cylinder. This central extension acts on a transfer ram 11 that has a clutch, in particular a magnetic clutch 12 fixed, but releasable via the coupling with a piston 18 a piston-cylinder unit 13 connected is.

Axial to the cylinder 4a closes a housing 5 a Fremdkraftaktuators for the brake booster (BKV) and preferably the pressure modulation for ABS, ESP and the like. This can, as in the example described here z. B. an electric motor with stator 6 with rotor 7 have, which are arranged in the housing. The rotor 7 that by means of storage 8th . 9 in the case 5 is stored, is part of a ball screw transmission. The spindle belonging to this gear 10 is in the rotor 7 rotatably mounted and has a central bore in which the transfer ram 11 is stored. The transfer ram 11 acts with its ends on the clutch 12 with permanent magnets according to the DE 10 2010 045 617.9 the assignee (incorporated herein by reference) associated with the DK pistons 18 a clutch 12 forms. This is part of the piston-cylinder unit or tandem master cylinder described below.

The tandem master cylinder 13 is axially adjacent to the housing 5 attached and has in known manner a cylinder and two pistons displaceably arranged therein 18 and 19 that form two working spaces. From the workrooms, hydraulic lines lead to a surge tank 13a and hydraulic lines 27 . 28 via a valve system to the wheel brakes (not shown) of the brake system. The illustrated in the drawing hydraulic actuator HCU can be constructed differently, according to different system or applications. An example of this is in the DE 10 2007 062 839 to which reference is made here for disclosure. It may also include the components of pressure control for an electro-hydraulic brake (EHB) (such as in the Brake Manual, Edition 1, Viehweg Verlag described) may be provided.

The following describes the mode of action and the resulting additional features and advantages:
The brake pedal 1 acts on the pedal ram 2 on the piston 4 , wherein the displaced volume of this via the hydraulic line to a hydraulic Wegsimulator 17 arrives. With the movement of the piston 4 are redundant displacement sensors S2, S4 via actuators 15 . 15a coupled. These then act on the sensors through the engine. The displacement sensors S2, S4 control the engine via an evaluation device (ECU) 6 and at the same time actuate a normally open 2/2-way solenoid valve 24 , The auxiliary piston is via a return spring 29 returned to the starting position. All other functions such as throttle check valve 23 and engine in case of engine failure are in the DE 10 2010 045 617.9 (to which reference is hereby made for disclosure).

The following description is therefore focused on the sensor module.

In the o. G. Patent application, the sensors are arranged in the pedal interface. This is connected via a wiring harness to the ECU, which is usually connected to the HCU. This wiring is expensive because the sensor lines must be shielded and also sealed when exiting the pedal interface and entering the ECU.

When displaced parallel to the THZ or actuator, all sensors can be combined with electrical cables in a sensor module and connected via a plug 30 be connected directly to the ECU. Since the cost of the electrical connection are low, z. B. the sensors are operated with reduced power supply.

Therefore, another advantage is that z. B. a third pedal travel sensor S2a can be used. This makes it possible to monitor the two pedal travel sensors S2 and S4 in a certain path range, or this S2a can also be used as a redundant brake light switch. In addition, from this position of the sensor module, both the level of the brake fluid by a magnetic flux-sensitive sensor, in particular Hall sensor S5 with magnet S5a in the float of the surge tank 13a are detected as well as the piston position of the SK piston via a magnetic flux-sensitive sensor, in particular Hall sensor S6 and magnet S6a in SK piston.

So that the angle of rotation of the rotor is also detected in the sensor module via the rotary encoder S1, the rotor rotation is via a gear 3 over a wave 20 to the target 22 (Permanent magnet) transmitted. Within the stator, the shaft is protected in the bobbin as the 3 shows. The shaft is in the housing of the actuator on both sides in bearings 21 stored.

Also protected in the stator and mounted on both sides in the actuator are the actuators 15 . 16 for the pedal travel sensors. These preferably act via racks on a gear with target, so that the two rotation angle Hall sensors S2 and S4 provide the pedal travel signal. Alternatively, it is conceivable that the actuation elements with a corresponding target act on different linear Hall sensors whose signals are converted by an evaluation circuit into a pedal-path-proportional signal. The sensor module is preferably attached to the THZ, has a dense, stable housing and is not shown on the front side together with the THZ on the flange z. B. the motor housing pressed. In the sensor module return spring act 32 on the actuators and flange of the pedal interface. The sensor signals are calibrated over a small free travel at the beginning of braking so that all tolerances are also compensated by temperature. The sensor module is with a plug 30 directly connected to the ECU without intermediate lines. The entire wiring harness for the integrated system only has one main connector 41 , which is connected to a vehicle power supply control unit and preferably gateway for the bus line.

At the in 2 illustrated embodiment is the actuator with motor 6 and housing 5 , Spindle, rotor and THZ same as 1 , Differences are those of the position of preferably two auxiliary cylinders or pistons, which are arranged in the axial direction at least partially in the region of the THZ and in particular combined or integrated with THZ. This eliminates the external connecting line from the piston 4 to the path simulator 17 , These pistons are over bars 35 and 35a pressed, with the pedal plate 34 connected and in the housing 5 are stored.

It is also possible only a piston which is connected via rigid actuating elements with the piston and the rods.

In the pedal plate is embedded the elastic member 33a with the flange sleeve 33 ,

In the drawing, the main dimensions are entered, which determine the total length. These show that the pedal travel is approximately 3.5 times in the overall length. The minimum distance of the pedal plate 34 to the housing 5 corresponds to the stroke and thus the main dimension of the pedal interface.

In the following dimensional chain, the pedal stroke again determines the spindle length next to the ball screw (KGT), the length of which depends on the piston force in addition to the stroke. The immersion of the DK piston in the housing 5 is also stroke-dependent like the rest of the THZ. An effective way to shorten the pedal stroke is to increase the pedal ratio.

The sensor module corresponds to that of 1 ,

2a shows the arrangement of the sensor module 31 parallel to the actuator housing, in which the ECU and HCU are mainly in the range of the actuator. Again, there is a direct contacting of the sensor module to the ECU. The latter also has a main plug 41 to the electrical system. The sensor module includes the sensors S2, S4 and S2a. To integrate the sensors S1, S5 and S6, the sensor module requires corresponding extensions to the brake fluid reservoir 14 , the THZ 13 and the gear 3 of the rotary encoder. The sensors S2, S4 and S2a are over the rod 35a with the actuators 15 . 15a activated. For this, the rod can 35a be formed as a tube.

Thus, essential facts are shown, which lead to a short-lasting actuator and at the same time reduce the cost of the pedal interface and sensor module. The assembly is easy.

3 shows a section through the stator of the electric motor with winding 36 , Bobbin 37 and 37a , Stator tooth 38 , Rotor 7 and outer casing (outer casing) 39 , According to the prior art, the stator teeth are pressed with coils in the outer jacket. The bobbins are designed so that they through recesses the actuators 15 and 6 take up. The profile can be round or, as at 16 also be rectangular. The wave 20 To the gear is provided in the middle. To prevent jamming, a game is provided. Through the recess in the bobbins, the elements are protected in the engine. With an additional encapsulation of the coils, the casting mold has the corresponding contour.

4 shows the design of the support of the sensor actuator. The sensors have very small actuating forces, the reset takes place via the in 1 shown return springs, which act in the sensor module. Should now be a terminal occur, so is in the sensor pad, which with the pedal interface 33 . 34 is connected, a predetermined breaking point 40 provided, which is effective when the operating force exceeds about 10 times the spring force.

5 - 5b show possible ECU architectures for the sensors, motor and valve control. The microcontrollers MC1 and MC2 are standard on all ABS and ESP systems. The microcontrollers are switched redundantly. By comparing different safety-related signals, errors are detected, and in the event of an error, the system is shut down. The output signals drive the solenoid valves MV and the pump motor, the latter if the invention is used in a system in which a conventional ABS / ESP is connected in parallel with the electric motor brake booster (BKV). In the present integrated system, where the EC motor does both BKV and the ABS function, an additional MC3 is used, which in turn is monitored by MC1 and MC2. The methods of monitoring and switching off microcontrollers MC1 and MC2, MC3 of MC1 and MC2 are known and therefore will not be described here.

The MC have a red. _Power supply and U _stab2 , which preferably from terminal 15 be supplied to the electrical system.

Furthermore, the functional and safety-related sensors are plotted as DG (pressure transducer) and S2, S4 and S2a pedal travel sensors.

The function of the brake signals, traditionally generated by the brake light switch, is extremely safety relevant to many systems such as engine and transmission control. Therefore, today, in all brake systems, either a fully redundant brake light switch or via the bus line the signal of the pressure transducer in conjunction with a non-redundant brake light switch available. The installation causes additional costs together with the wiring harness and the brake light switch. The present integrated brake system with two Pedalweggebern and additionally a pressure transducer dispenses with the above-mentioned additional effort. There are several ways to do this:
5 , The MC1, MC2 and MC3 are connected to a redundant power supply, as are the pedal travel sensors S2 and S4. The brake signal is fed redundantly from MC1 and MC3 the output BS to the onboard supply control unit. The signal from the pressure transmitter DG is sent from the MC1 to the bus z. B. CAN supplied. If the MC1 and MC2 fail, the MC3 can still operate the BKV in emergency mode. As a substitute for the pressure transducer and not shown phase current measurement can serve over a shunt.

The solution presented here of generating the brake signal is much safer and at the same time less expensive than the conventional method.

5a shows a further alternative in that the signal of the pedal travel sensor is fed directly to the output BS, but must still be processed separately for output to the onboard power supply control unit.

5b uses an additional pedal travel sensor, preferably a switching signal, which does not need to be processed separately for output at BS. This third sensor allows the detection of the failure of S2 or S4, so that then in case of failure of a sensor S2 or S4 in emergency operation of the BKV can be operated. The failure of the BKV is safety-relevant, since switching to the fallback level requires considerably higher pedal forces for a specific braking action.

LIST OF REFERENCE NUMBERS

1

brake pedal

2

pedal tappet

3

Gear for rotary encoder

4

auxiliary piston

4a

Auxiliary piston cylinder

5

casing

6

electric motor

7

rotor

8th

camp

9

camp

10

spindle

11

transfer ram

12

clutch

13

Tandem Master Cylinder (THZ)

13a

surge tank

14

surge tank

15

actuator

15a

actuator

16

actuator

17

hydraulic path simulator

18

SD-piston

19

SK-piston

20

wave

21

camp

22

target

23

Flow control valve

24

2/2-way solenoid valve (MV)

25

Magnet in the float

26

Magnet in SK piston

27

hydraulic line

28

hydraulic line

29

Return spring

30

sensor connector

31

sensor module

32

Return springs

33

flanged

33a

elastic member

34

pedal plate

35

Rod 1

35a

Rod 2

36

winding

37

bobbins

37a

bobbins

38

Statorzahn (yoke tooth)

39

Outer casing (outer casing)

40

Breaking point

41

main connector

MC1

Microcontroller MC for ABS / ESP

MC2

dto. redundant

MC3

dto. for engine control

Ustab1 / 2

voltage stabilization

DG

thruster

BS

Output circuit brake signal to onboard supply control unit

S1

Rotation angle sensor

S2

Pedal travel sensor

S4

Pedal travel sensor

S2a

Pedal travel sensor

S5

Brake fluid level sensor (magnetflußsensitiver sensor, such as Hall sensor)

S6

Piston position sensor (magnetflußsensitver sensor, such as Hall sensor)

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008063771 [0004]
• DE 102010045617 [0004, 0004, 0009, 0014, 0021, 0023]
• DE 102007062839 [0022]

Cited non-patent literature

• Brake Manual, Edition 1, Viehweg Verlag [0022]

Claims (27)

Actuating device for a vehicle brake system, with a first piston-cylinder unit, the at least one working chamber to be connected via at least one hydraulic line with at least one wheel brake of the vehicle, further comprising an electro-mechanical drive means and an actuating device, in particular a brake pedal, characterized in that a sensor device ( 31 ) is provided which at least partially in the region of the piston-cylinder unit ( 13 ) is arranged. Actuating device according to claim 1, characterized in that the sensor device is a sensor module ( 31 ), which comprises at least two sensors (S1, S2, S2a, S4) in a structural unit, in particular on a common printed circuit board. Actuating device according to claim 1 or 2, characterized in that the sensor device ( 31 ) has at least one, in particular two or three pedal stroke sensors (S2, S2a, S4) and / or rotary encoder (S1). Actuating device according to one of the preceding claims, characterized in that at least one (linear or rotary) sensor by means of a parallel to the axis of the drive means, in particular by the drive means or the housing extending or mounted actuating element ( 15 . 16 ) is operable. Actuating device according to one of the preceding claims, characterized in that for resetting at least one linear sensor actuating element, a spring device ( 29 ) is provided. Actuating device according to one of the preceding claims, characterized in that the sensor actuating device ( 31 ) an over-force protection, in particular predetermined breaking point ( 40 ) () having. Actuating device according to one of the preceding claims, characterized in that the sensor device has at least one further sensor, in particular liquid level sensor (S5) and / or piston position sensor (S6). Actuating device according to one of the preceding claims, characterized in that the sensor device ( 31 ) on the piston-cylinder unit ( 13 ) is attached. Actuating device according to one of the preceding claims, characterized in that the sensor device ( 31 ) connected to an electronic control unit (ECU), in particular contacted directly. Actuating device according to one of the preceding claims, characterized in that a redundant power supply is provided for the sensors. Actuating device for a vehicle brake system, having a first piston-cylinder unit whose at least one working space is to be connected via at least one hydraulic line with at least one wheel brake of the vehicle, further comprising an electro-mechanical drive device and an actuating device, such as a brake pedal, in particular according to one of the preceding claims, characterized in that the actuating device at least one further piston-cylinder unit ( 4 ) having a hydraulic path simulator ( 17 ) acted upon at least partially in the region of the first piston-cylinder unit ( 13 ) is arranged, the piston ( 4 ) by means of the actuating device ( 1 . 2 ) and which via a connecting device with a piston of the first piston-cylinder unit ( 13 ) connected is. Actuating device according to claim 11, characterized in that the force of the actuating device, in particular the pedal force, by means of plunger or rod ( 35a ) to at least one of the further piston-cylinder units ( 4 ) is transmitted. Actuating device according to claim 12, characterized in that the or the plunger ( 35a ) run parallel to the axis of the drive device, in particular by the drive means, preferably by the bobbin of the winding of the electric motor. Actuating device according to one of claims 11 to 13, characterized in that for transmitting the force of the actuating device, in particular the pedal force, a pedal plate ( 34 ) is provided. Actuating device according to claim 14, characterized in that an elastic device ( 33 . 33a ), via which the operation of the pedal travel sensor takes place, on the pedal plate ( 34 ) is attached or integrated in this. Actuating device according to one of claims 11 to 15, characterized in that the further piston-cylinder unit ( 4 ) with the first piston-cylinder unit ( 13 ), in particular integrated. Actuating device according to one of claims 11 to 16, characterized in that for resetting the / the piston of the further piston-cylinder unit (s) a spring device, in particular a central return spring, is provided. Actuating device according to one of the preceding claims, characterized in that a separate brake light switch is avoided by a suitable sensor or motor control. Actuating device according to claim 18, characterized in that a separate brake light switch is replaced by using redundant pedal travel sensors and redundant power supply. Actuating device according to claim 18, characterized in that by using a third pedal travel sensor, preferably Hall switch, a separate brake light switch is replaced. Actuating device according to claim 20, characterized in that the third sensor is used for monitoring the other two pedal travel sensors. Actuating device, in particular according to one of the preceding claims, characterized in that the ECU outputs to the onboard power supply control units a pressure or motor current proportional signal predominantly via the phase current line and a pedal position proportional signal through a redundant power supply via a separate line. Actuating device, in particular according to one of the preceding claims, characterized in that a separate brake light switch is replaced by using a third microcontroller (MC) for motor control and generation of the brake signal. Actuating device, in particular according to one of the preceding claims, characterized in that redundant Pedalweggeber and a pressure transducer are used to generate braking signals. Sensor module, in particular for use in an actuating device according to one of the preceding claims, characterized in that at least two pedal travel sensors (S2, S2a, S4) and a rotary encoder (S1) are combined to form a structural unit, in particular on a printed circuit board. Sensor module according to claim 25, characterized in that the structural unit has at least one further sensor, such as a liquid level sensor (S5), piston position sensor (S6) and / or pedal travel sensor (S2a). Sensor module according to claim 18 or 19, characterized in that a direct contact to the ECU, in particular a plug connection ( 30 ), is provided.

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