ACTUATING APPARATUS FOR A MOTOR VEHICLE BRAKE

Abstract

The invention relates to an actuating device for a motor vehicle brake, comprising the following components: an actuating device, in particular in the form of a brake pedal, a pressure supply device (11), in particular a reciprocating pump or double-acting reciprocating pump, driven by an electric motor drive (M), a piston-cylinder unit (main cylinder) (10) that can be actuated by means of the actuating device, that is connected hydraulically with a hydraulic fluid reservoir (BFR) and that forms at least two pressure chambers that are connected with hydraulic brake circuits, a valve assembly (HCU) with valves for adjusting brake pressures in a wheel-specific manner and for disconnecting or connecting the wheel brakes from or to the pressure supply device (11) and the piston-cylinder unit (10), an electronic control unit (ECU), at least one sensor device, having at least one sensor or evaluation element (3, 4, 5, 24, 24a) and a sensor target (5a, 23, 23a), preferably based on an electromagnetic principle,
for sensing a movement of a device component.

According to the invention,

at least one sensor or evaluation element (3, 4, 5, 24, 24a) of the sensor device is arranged on or in the electronic control unit (ECU), in particular on a system printed circuit board (PCB) of the control unit (25), and
that a movement of the device component (10; 45; 46; 48) is transmitted to the electronic control unit (ECU) (25) via a sensor actuating device, in particular via a mechanical actuating mechanism (17, 18, 19) or via a sensor target (5a, 23, 23a) connected with the device component and magnetic flux-conducting components (43, 43, a, 43b) based on ferromagnetic materials.

Claims

1. Actuating apparatus for a motor vehicle brake, comprising the following components: an actuating device, in particular a brake pedal, a pressure supply device (11), in particular a reciprocating pump or double-acting reciprocating pump, driven by an electric motor drive (M), a piston-cylinder unit (main cylinder) (10) that can be actuated by means of the actuating device, that is connected hydraulically with a hydraulic fluid reservoir (VB) and that forms at least two pressure chambers that are connected with hydraulic brake circuits, a valve assembly (HCU) with valves for adjusting brake pressures in a wheel-specific manner and for disconnecting or connecting the wheel brakes from or to the pressure supply device (11) and the piston-cylinder unit (10), an electronic control unit (ECU), and at least one sensor device, having at least one sensor or evaluation element (3, 4, 5, 24, 24a) and a sensor target (5a, 23, 23a), preferably based on an electromagnetic principle, for sensing a movement a device component, characterised in that at least one sensor or evaluation element (3, 4, 5, 24, 24a) of the sensor device is arranged in the electronic control unit (ECU), in particular on a system printed circuit board (PCB) of the control unit (25) or is connected with this, and that a movement of the device component (10; 45; 46; 48) is transmitted to the electronic control unit (ECU) (25) via a sensor actuating device, in particular via a mechanical actuating mechanism (17, 18, 19) or via a sensor target (5a, 23, 23a) connected with the device component and magnetic flux-conducting components (43, 43, a, 43b) based on ferromagnetic materials.

2. Actuating apparatus according to claim 1, characterised in that the sensor or evaluation elements (3, 4, 5, 24, 24a) of at least one sensor device, in particular the pedal travel sensor(s), or of a group of sensor devices, in particular all sensor devices, are arranged on the system printed circuit board (PCB) (25) arranged in the electronic control unit (ECU).

3. Actuating apparatus according to claim 1 or 2, characterised in that at least the sensor or evaluation elements of the sensor device that is relevant in terms of dynamic function with critical reliability and accuracy (pedal movement sensor device, motor rotation angle sensor device, piston movement sensor device) are arranged in the electronic control unit (ECU), in particular on the system printed circuit board (25).

4. Actuating apparatus according to any of the preceding claims, characterised in that a sensor device for determining the movement travel of a piston (10) of the piston-cylinder unit (main cylinder) or of a brake pedal (BP) connected thereto is provided, wherein the actuation of the sensor target (23, 23a) is effected by means of the mechanical actuating mechanism, in particular by means of a linkage and gear arrangement (17, 18, 19).

5. Actuating apparatus according to any of the preceding claims, characterised in that a sensor device for determining the movement travel of a piston (10) of the piston-cylinder unit or of a brake pedal (BP) connected thereto is provided, wherein at least one sensor target (23) is arranged on the piston (10) and wherein the transmission to the associated sensor or evaluation element is effected by means of flux-conducting components (43, 43a, 43b).

6. Actuating apparatus according to any of the preceding claims, characterised in that a sensor device for determining the motor or rotor movement is provided, wherein the actuation of the sensor target (23, 23a) is effected by means of the mechanical actuating mechanism, in particular by means of a linkage and gear arrangement (17, 18, 19, 26, 26a, 34, 34a).

7. Actuating apparatus according to claim 6, characterised in that the gearing is arranged in a separate housing on or in the motor and a frictional coupling with the target drive is provided.

8. Actuating apparatus according to any of the preceding claims, characterised in that a sensor device for determining the motor or rotor movement is provided, wherein at least one sensor target is arranged on the rotor or on an element connected thereto, in particular a pole disc, and the transmission to the electronic control unit (ECU) is effected by means of flux-conducting components (43, 43b).

9. Actuating apparatus according to any of the preceding claims, characterised in that a sensor device for determining the movement of a level sensor is provided, in particular in a float (46) of a reservoir (VB), wherein a sensor target (23) is arranged on a moveable part of the level sensor, in particular on the float, and the transmission from the sensor target (23) to the sensor or evaluation element is effected by means of flux-conducting components (53, 43a, 43b).

10. Actuating apparatus according to any of the preceding claims, characterised in that the distance of the sensor target or the flux-conducting components from the sensor or evaluation element is short, in particular less than 5 mm.

11. Actuating apparatus according to any of the preceding claims, characterised in that at least one of the sensor or evaluation elements is a Hall element, wherein in particular its external and protective circuitry is arranged on the system printed circuit board (PCB) (25).

12. Actuating apparatus according to one of the preceding claims, characterised in that at least one sensor target is actuated via a pinion (9, 9a).

13. Actuating apparatus according to claim 12, characterised in that a play compensation is provided on the pinion (9, 9a) that in particular has an elastic shaft (19).

14. Actuating apparatus for a motor vehicle brake, in particular according to any of the preceding claims, characterised in that the actuating device has at least a first (GH1) and a second (GH2) housing unit, wherein the first housing unit (GH1) accommodates, in particular, all pistons of the piston-cylinder unit (main cylinder) and the pressure supply unit and the second housing unit (HCU)(GH2) accommodates the valve assembly.

15. Actuating apparatus according to claim 12, characterised in that the control unit (ECU) is arranged in a third housing unit (25) that is in particular mounted directly on the second housing unit (HCU) (GH2) and is connected with this.

16. Actuating apparatus according to any of the preceding claims, characterised in that the motor (M) is connected with the first housing unit (GH1) or the pressure supply device (11).

17. Actuating apparatus according to any of the preceding claims, characterised in that the motor (M) of the drive is attached to the first housing unit (GH1), wherein in particular the motor axis is oriented at an angle (alpha) of less than 30 relative to the longitudinal axis of the first housing unit (GH1).

18. Actuating apparatus according to any of the preceding claims, characterised in that the actuation axis or longitudinal axis of the piston-cylinder unit (main cylinder) runs substantially perpendicular to the actuation axis or longitudinal axis of the pressure supply device (11).

19. Actuating apparatus according to any of the preceding claims, characterised in that the reservoir (VB) is arranged at the side of the first housing unit (GH1) and the second housing unit (GH2) as well as the electronic control unit (ECU) and is in particular connected with the suction intake of the pressure supply unit (11).

20. Actuating apparatus according to any of the preceding claims, characterised in that at least one sensor actuating device is arranged partially in the first (GH1) or/and the second housing unit (GH2) and/or the motor housing or is passed through the same.

21. Actuating apparatus according to any of the preceding claims, characterised in that redundant pedal travel sensors are actuated by means of gear racks (26, 26a) that are coupled with a brake pedal, in particular via a piston plate.

22. Actuating apparatus according to any of the preceding claims, characterised in that at least one sensor actuating device has a device for converting a translational movement into a rotational movement.

23. Actuating apparatus according to claim 22, characterised in that that the pedal travel sensors detect a translational movement, in particular of the brake pedal, which is converted into a rotational movement of a target, wherein the target is in particular realised as a N/S permanent magnet.

24. Actuating apparatus according to any of the preceding claims, characterised in that at least one sensor actuating device has a device for changing the direction of movement, in particular perpendicular to the actuation direction.

25. Actuating apparatus according to any of the preceding claims, characterised in that the motor housing has an extension (7) for collecting leaking fluid, wherein in particular a sensor (8) for detecting leaking fluid is provided in the extension.

26. Actuating apparatus for a motor vehicle brake, having an actuating device, in particular a brake pedal, a pressure supply device (pump) driven by an electric motor drive, a piston-cylinder unit (main cylinder) that can be actuated by means of the actuating device, that is connected hydraulically with a pressure medium reservoir and that forms at least two pressure chambers that are connected with hydraulic brake circuits, a valve assembly with valves for adjusting brake pressures in a wheel-specific manner and for disconnecting or connecting the wheel brakes from or to the pressure supply device and the piston-cylinder unit and possibly further valves and an electronic control unit (ECU), in particular according to any of the preceding claims, wherein sensors are provided, characterised in that at least the sensor elements of the pedal travel sensors, in particular all sensor elements, are arranged on a system printed circuit board (PCB).

27. Actuating apparatus according to claim 26, characterised in that sensor actuators are arranged in a first housing unit (GH1) or/and in a second housing unit (GH2) and movements of the actuating device, in particular of the brake pedal and of the motor rotor, are transmitted to a sensor target (in particular a magnet), and wherein an evaluation element of the sensor is arranged on a system printed circuit board (PCB) in the control unit (ECU).

28. Actuating apparatus according to claim 26 or 27, characterised in that the sensor target is actuated via a pinion (9, 9a).

29. Actuating apparatus according to any of claims 26 to 28, characterised in that redundant pedal travel sensors can be actuated by means of gear racks that are coupled with a brake pedal or a piston plate.

Description

[0061] In the drawings:

[0062] FIG. 1: shows a schematic representation of an actuating device for a brake system for a motor vehicle;

[0063] FIG. 2: shows a view of the brake system from the front, with the subdivision and structure of the main components;

[0064] FIG. 3: shows a motor sensor drive;

[0065] FIG. 4: shows a first part of a pedal travel sensor drive (connecting element to the actuating pedal);

[0066] FIG. 4a: shows a second part of a pedal travel sensor drive (connecting element to the target);

[0067] FIG. 5: shows a piston travel measurement with several magnet targets with a flux-conducting component leading to the sensor evaluation element;

[0068] FIG. 5a: shows a piston travel measurement with a magnet target in the piston and several flux-conducting components/sensor evaluation elements;

[0069] FIG. 5b: shows a further piston travel measurement with flux-conducting components;

[0070] FIG. 6: shows the position of the level sensor with flux-conducting components;

[0071] FIG. 7: shows motor sensors with segment sensor and flux-conducting components.

[0072] FIG. 1 shows the structuring and interaction of the individual components of a 1-box brake system. The essential components consist of: [0073] brake pedal (BP) [0074] pedal interface (PI) with tandem main cylinder (THZ) [0075] motor (M) with pressure piston [0076] hydraulic block (HCU or GH2) [0077] control unit (ECU) [0078] plug (connection to vehicle's electrical system for supply and communication) [0079] reservoir or compensating tank

[0080] The interaction with the driver takes place starting from the brake pedal, which acts on the TMC piston via the pedal interface. At all times, the pedal travel is measured by means of two sensors housed in the system for this purpose. The displaced volume from the TMC piston passes on into the hydraulic unit (HCU), which contains solenoid valves (MV) and a pressure sensor. All valves and the pressure sensor as well as all sensor connections are connected with the electrical control unit and combined and enclosed in the housing of the electrical control unit. The connected sensors in the ECU include a motor position sensor, two pedal travel sensors, a pressure sensor, a filling level sensor and, optionally, an electrode for leakage flow detection, with a correspondingly small container, which is for example integrated in the HCU or ECU housing. The housing is fixed to the hydraulic unit (HCU) by means of screws. A sealing ring between the two components (HCU and ECU) prevents the penetration of various foreign bodies. The energy supply and the external communication with other control devices is effected via a plug on the brake system. The system also has a pressure supply, which is driven by an electric motor. This pressure supply can take different forms, which are for example described in DE 10 2014 117 726. In order to supply the whole brake system with the necessary brake fluid, a reservoir or supply container is situated on the system.

[0081] FIG. 2 shows one mechanical structure from the brake system described with reference to FIG. 1, starting from the front in the direction of the bulkhead of a vehicle. Beginning from the bottom, the motor (M) is attached to the housing HU1 by means of the mounting 14. The motor drives a pump 11 connected via suction valves 16 with the reservoir (VB). Possible pump designs are described in the patent specifications DE 10 2014 109 628 and DE 10 2014 117 726. The housing GH1, in which moveable pistons are mounted, is integrated on a mounting flange 13 attached to the bulkhead and is accessible from the engine compartment, which makes possible a so-called front-bolted installation. For this purpose, a corresponding recess for the fastening tool needs to be provided on the side of the reservoir or supply container (VB).

[0082] The drive of a sensor target is mounted in the housing GH2; these are illustrated in detail in FIGS. 3a and 4. The motor rotation angle target can be installed in front of (9a) or behind (9b) the motor and can measure the angular position of the motor. As already described with reference to FIG. 1, the control unit (ECU) is mounted, in a sealed manner, on the housing HU2 with solenoid coils and contacts for all sensors, valves and motor.

[0083] To the side or also to the front there is a connecting element 1 (main plug) with the wiring harness 2 leading to the vehicle's electrical system. Attached on the underside of the motor housing is a housing extension in which the aforementioned electrode for leakage detection is housed. A possible leakage flow is for example conducted from the piston into a bowl on the spindle and downwards through a spindle bore. If the direction of the pedal interface is considered as the axis of rotation, the system can be installed in the vehicle rotated by +/90. Naturally, the position of the brake pedal remains the same; however, the aforementioned collecting container must be rearranged accordingly. Possible positions would be next to the GH1 or even in the ECU.

[0084] Alternatively to the embodiment shown, other conceivable variants of 1-box brake systems exist (for example as described in DE102012213216A1). In this embodiment too, due to the limiting conditions for installation, the motor and pedal stroke or piston travel is arranged in immediate proximity to the PCB of the ECU and a plurality of sensors is to be connected with the ECU. In other words, also in this approach, and in alternative approaches to packaging solutions, the flexible connection of sensor signals via mechanical transmission members or flux-conducting components according to the invention is advantageous and avoids complicated contacting, reduces costs and increases reliability.

[0085] FIG. 3 shows the drive of a motor rotation angle sensor illustrated in FIG. 2. The drive gear wheel 17 is mounted on the shaft in front of or behind the motor. This gear wheel 17 is bevel geared to reduce noise and engages with a drive gear wheel 18, which is pressed onto an anti-rotation lock 20. The shaft is preferably mounted in the housing HU2 in a bearing bush 21. The flexural elasticity provided by the extensive length from the bearing 21 to the gearing 20a is used to ensure that the gear wheel 17 runs without play. On the shaft end nearest the sensor there is a target magnet 23 with a receptacle made of plastic 22, which forms an opposing storage in the housing GH2. The magnet is sensed by means of a sensor element 24 (for example a Hall sensor) on the system printed circuit board 25.

[0086] A gear wheel housing is fixed inside the motor housing that contains the bearings of the drive gear wheel on both sides. The knurled shaft is adequately secured against rotation in the resilient flange of the gear wheel 18, which substantially only needs to withstand the slight bearing friction and moment of inertia during acceleration of the motor. The motor with gear drive can thus also be tested during the final testing of the motor, by plugging a shaft into the measuring device. During the final installation of the assemblies, the shaft 19 with its bearings is fixed in the GH2 and the sensor tested in the assembled state.

[0087] FIG. 4 shows the actuation of the pedal travel sensors. For safety reasons, two pedal travel sensors are used that are used for pedal force measurement via a spring elementsee also the applicant's DE 10 2011 101 655, which will be further addressed and referred to here. Thus, a pedal tappet 27 with a pedal plate 28 is coupled with a piston 31, which acts on a spring element 30. This acts on the piston 31 in order to generate pressure in the main cylinder (THZ) in the pressure chamber 33. In this connection, see the applicant's patent DE 10 2014 117 726, to which reference is made in this respect. This piston 31 is connected with a piston plate 29. In order to actuate the sensor the pedal plate 28 is connected with a first gear rack 26 and a piston plate 29 is connected with a second gear rack 26a. The two gear racks 26, 26a drive a gear wheel each, 24, 34a, as shown in FIG. 4a. The first housing GH1 is fixed in the front wall region with the mounting flange 13.

[0088] FIG. 4a shows a sensor drive for both pedal travel sensors. Gear racks 26 and 26a act on different levels on gear wheels 34 and 34a. The connection to the sensor target very largely corresponds to the motor sensor shown in FIG. 3. Here too, flexurally elastic shafts 19a, 19b are used that are mounted in bearing bushes 21 and 21a and fixed together with the sensor target 22a and with the target 23a (magnet) so as to prevent rotation. The target 23a acts on a sensor element 24a, which is fixed, together with the other sensor elements, on the common system printed circuit board (PCB) 25 in an electrically conductive manner. In line with the proven prior art, the housing 35 of the control unit ECU contains the system printed circuit board (PCB) 25 with all components and the solenoid coils shown in FIG. 2. Due to heat dissipation, the system printed circuit board (PCP) 25 is mounted on an aluminium plate, since the MOSFETs used for the motor control in particular generate heat loss. This can be transferred simply through the aluminium plate, via a thermally conductive strip, to the second housing.

[0089] FIG. 5 shows an arrangement for measuring a movement of a piston 10, which can also be connected with a brake pedal (BP) and thus also measures the pedal travel. The magnetic flux of a target magnet is passed to the sensor via flux-conducting components 43 or 43b by means of a sensor element 24a, which is mounted on the system printed circuit board 25. The magnets are magnetised differently depending on the arrangement of the magnetic circuit with flux-conducting components. The upper and lower halves of the figure show two different possible arrangements or embodiments. The arrangement shown above is based on the change in flux of several magnets 23 of differing polarity and can be measured by means of the sensor element 24a. In contrast, the arrangement shown below and its travel measurement only require one target magnet; however, the magnetic flux must be conducted through the flux-conducting components in a different way. The back iron 43 and the flux-conducting component 43a are configured such that that with the movement of the magnet in the direction of measurement a N/S polarity can be detected. Depending on the arrangement, the air gap, magnets and flux-conducting components must be designed accordingly in order to guarantee a suitable measurement. Ultimately, the linearization and the signal processing of the travel measurement can take place either in the sensor elements or in the ECU. In connection with FIG. 5, the view X of the embodiment shown above in FIG. 5 is illustrated separately below. The piston 10, flux-conducting components 43, permanent magnets 23 and sensor element 24a are shown in the illustration.

[0090] In terms of construction design, different options exist for minimising the air gap, for example in A, gluing or caulking in a recess of the housing 44. The flux-conducting components can be manufactured economically as stamped, pressed or moulded parts. Depending on the requirements in terms of travel and accuracy, different sensor targets can be connected in succession. The signal waveform of the sensor element, for example sinusoidal, is prior art and is not shown separately.

[0091] FIG. 5a shows, in a simplified manner, an alternative for the arrangement of the sensor target 23 and sensor element 24a with flux-conducting components, in that only a single target in the piston 10 with seal 10a activates different sensor elements 24a. The magnetic circuit is described in FIG. 5.

[0092] FIG. 5b shows an arrangement for pedal travel measurement in which the sensor target 23 is mounted on a separate rod 45 or slider in the housing 44 and is connected with the pedal plate 28. The magnetic circuit is shown in the illustration and, with the target magnet 23, which is connected with the rod or bar 45, has a N-S polarity. The flux is passed via the flux-conducting components 43 and 43b to the sensor element 24a. This arrangement allows constructively optimised housing within the overall packaging of the system independently of the main cylinder piston.

[0093] FIG. 6 illustrates the principle of using flux-conducting components to measure the filling level of the brake fluid reservoir VB. For this purpose, the sensor target is mounted in the float 46, and the magnetic flux is passed via the flux-conducting components 43, 43a, 43b to the sensor element 24a, which is in turn mounted on the system printed circuit board (PCB) 25. In this case the flux-conducting components are injection-moulded into a housing connected with and fixed to the housing unit GH1 or GH2. The sealing of the ECU housing is provided by the seal S.

[0094] FIG. 7 illustrates the principle of using flux-conducting components to measure the motor position, as an alternative to FIG. 3. The arrangement has a known magnet ring 48 composed of segment magnets on the motor, which is connected with the rotor 47. The magnet ring is sensed with a sensor element 24a and depending on the number of magnet ring segments can measure a certain rotor angle in absolute terms. This application is widely used, this structure having been modified with flux-conducting components. The magnet ring can have a radial arrangement (upper half of figure) or axial arrangement of the poles (lower half of figure). Here too, the magnetic flux is conducted from the target 23 via flux-conducting components 43, 43a, 43b to the sensor element 24a on the system PCB 25 in the ECU housing. The magnetic circuit can correspond to FIG. 5b, in which the flux-conducting components are arranged in a segment and are mounted in the housing unit 1 or 2. The motor is connected electrically with the system printed circuit board (PCB) 25 via electrical connecting elements 12.

[0095] This sensor concept, in which the sensor element of preferably all the sensors is mounted on the system printed circuit board (PCB) 25, represents an economical solution with a great deal of latitude in terms of constructive design.

LIST OF REFERENCE SIGNS

[0096] 1 connecting element (main plug) [0097] 2 wiring harness [0098] 3 sensor element for pedal travel [0099] 3a actuation target for pedal travel sensor [0100] 4 sensor element for motor rotation [0101] 4a actuation target for motor travel sensor [0102] 5 sensor element for filling level [0103] 5a target for filling level sensor [0104] 6 float in the reservoir [0105] 7 extended motor housing or leak collector [0106] 8 electrode [0107] 9 drive for target actuation of motor encoder in front of the motor rotor [0108] 9a drive for target actuation of motor encoder behind the motor rotor [0109] 10 TMC piston [0110] 10a piston seal [0111] 11 pump or pump piston [0112] 12 electrical connecting element to motor with several cables [0113] 13 flange for mounting on front wall [0114] 14 motor mounting [0115] 15 hydraulic connection to wheel brake [0116] 16 connection to pump suction valve [0117] 17 drive gear wheel [0118] 18 output gear wheel [0119] 19 shaft 1 [0120] 19a/b shaft 2 and 3 [0121] 20 anti-rotation lock (knurl) [0122] 21 bearing bush [0123] 21a bearing bush [0124] 22 target holder [0125] 22a target holder [0126] 23 target (magnet) [0127] 23a target (magnet) [0128] 24 sensor element [0129] 24a sensor element [0130] 25 system printed circuit board PCB [0131] 26 gear rack 1 [0132] 26a gear rack 2 [0133] 27 pedal tappet [0134] 28 pedal plate [0135] 29 piston plate [0136] 30 spring for force-displacement measurement [0137] 31 piston [0138] 32 sealing and bearing bush [0139] 33 pressure chamber for piston [0140] 34 gear wheel 1 [0141] 34a gear wheel 2 [0142] 35 ECU housing [0143] 36 thermally conductive strip [0144] 37 E/E construction units [0145] 38 assemblies, for example air conditioning [0146] 39 front wall [0147] 40 cable compartment [0148] 41 limit stop ring [0149] 42 gear wheel housing [0150] 43 flux-conducting components [0151] 43a back iron flux-conducting component a [0152] 43b ditto b [0153] 44 housing [0154] 45 rod/slider [0155] 46 float [0156] 47 rotor [0157] 48 magnet ring [0158] GH1 first housing unit [0159] GH2 second housing unit [0160] VB brake fluid reservoir [0161] PI pedal interface [0162] MV solenoid valves [0163] LL left-hand drive [0164] RL right-hand drive [0165] PCP circuit board [0166] K.sub.SP magnet coil connection [0167] D seal