ACTUATION DEVICE FOR A HYDRAULIC ACTUATION SYSTEM, IN PARTICULAR A MOTOR VEHICLE BRAKE OR AN ELECTRIFIED CLUTCH ACTUATOR, OPTIONALLY WITH GEAR ACTUATOR

Abstract

An actuation device for a hydraulic actuation system, e.g., a motor vehicle brake or an electrified clutch actuator, may include a connection for an actuation device; a pressure supply device, driven by an electromotor drive, in the form of a piston or double-stroke piston pump; a piston cylinder unit that may be actuated by means of the actuation device; and an electronic control unit. An axis of the piston cylinder unit and an axis of the pressure supply device may be arranged in parallel.

Claims

1. An activation device for a hydraulic activation system of a vehicle, the activation device including: a pressure supply device with a piston cylinder unit, an electric motor drive arranged to drive a piston of the pressure supply device via a ball screw drive, wherein the ball screw drive comprises a spindle and a nut, and a four-point bearing arranged to receive axial forces in an axial direction of the ball screw drive that occur when the piston is driven, wherein either: the spindle is axially fixed by the four-point bearing and is set in a rotary motion by the electric motor drive, so that the nut adjusts the piston in the axial direction of the ball screw drive, or the nut is axially fixed by the four-point bearing and is set in a rotary motion by the electric motor drive, so that the spindle adjusts the piston in the axial direction of the ball screw drive.

2. The activation device according to claim 1, wherein the four-point bearing is arranged to one side in relation to the ball screw drive in the axial direction of the ball screw drive.

3. The activation device according to claim 1, wherein the four-point bearing is arranged in the axial direction of the ball screw drive adjacent to a stator of the electric motor drive.

4. The activation device according to claim 1, wherein the four-point bearing is pressed in a motor housing of the electric motor drive.

5. The activation device according to claim 1, wherein the ball screw is formed inside a rotor of the electric motor drive and the spindle or the nut rotates with the rotor.

6. The activation device according to claim 5, wherein the four-point bearing cooperates with the rotor in a force-transmitting manner to receive the axial forces.

7. The activation device according to claim 1, wherein the piston is arranged next to the ball screw drive in the axial direction of the ball screw drive.

8. The activation device according to claim 1, wherein the piston is connected to the nut or the spindle in a torque-proof manner.

9. The activation device according to claim 1, wherein the piston cylinder unit comprises a piston or a double-stroke piston pump.

Description

IN THE DRAWINGS

[0066] FIG. 1 schematically shows a representation of the block of the most important elements;

[0067] FIG. 1a shows the corresponding side view;

[0068] FIG. 2 shows an alternative arrangement to FIG. 1;

[0069] FIG. 2a shows the corresponding side view;

[0070] FIG. 2b shows the sound-damping arrangement to the bulkhead;

[0071] FIG. 3 shows a sectional drawing with motor, sensor, electric connection of HCU and ECU with magnetic coil, pressure piston with suction valves;

[0072] FIG. 4 shows a perspective representation of a possible arrangement; and

[0073] FIG. 4a shows a sectional drawing of a possible arrangement of components.

[0074] FIG. 1 shows a possible embodiment of the actuation device according to the invention for use in a vehicle for pressure supply of the vehicle brake system or a clutch and gear actuator. The motor M is in this case arranged on a second horizontal axis H1 parallel to the axis H of the first cylinder piston unit. The pedal plunger 26 acts on this axis H which can be connected to the brake pedal not represented. In addition to the motor M, the piston 11 of the pressure supply device can also be arranged on the axis H1.

[0075] The pedal interface P1 and the master cylinder arrangement 10 with the pressure pistons for the two brake circuits, e.g. usually a THZ or an arrangement corresponding to EP2015/068696 are also arranged in the main axis H. They are part of the housing unit GH1 together with the components of the pressure supply device, e.g. piston cylinder arrangement 11. The motor M, which drives the pressure supply device 11, is flanged to the first housing GH1. The valve arrangement HCU with front-side connections 15 to the wheel brakes and reservoir VB is positioned above or in the vertical direction. The control and regulating unit ECU with plug 1, which is connected to the PCB 25 via the contacts KS, is arranged below.

[0076] FIG. 1a shows the part section XX of the actuation device of FIG. 1. The control and regulating unit ECU designed in the cross-section in a U shape hereby comprises the housing unit GH1 from below, wherein the THZ piston 10 is arranged above the piston 11 of the pressure supply device. The valve arrangement HCU is arranged above the first housing GH1, said valve arrangement receives the solenoid valves MV with vertical axis VMV on both sides of the first housing GH1. The solenoid valves MV are electrically connected at their underside with the contacts KSP to the circuit board PCB of the control and regulating unit ECU. Alternatively to the front side, the plug 1 can also be arranged laterally on the control and regulating unit ECU. An extremely narrow design results by way of the previously-described features with the vertical stacking of control and regulating unit ECU, pressure supply device 11 and piston cylinder unit 10 and valve arrangement HCU. This also results in an extremely compact design with good ventilation of all hydraulic components.

[0077] FIG. 2 shows an alternative arrangement of the main components and housing structures with axis H1 of motor M and pressure supply 11 parallel to the actuation axis H, wherein the pedal plunger 26 here acts on the pedal interface P1 and said pedal interface is connected to at least one pressure piston and the pedal path sensor actuation device. Detail will not be given here on the sensors. Hall elements are usually used.

[0078] The motor M is connected via an intermediate part 14 made of sound-damping material to the housing unit GH1 by means of the fastening screw 14a. The high-frequency vibrations of motor M and piston drive e.g. KGT are reduced by the intermediate part 14. The first housing unit GH1 has an L-shaped construction in the cross-section in the case of this embodiment and is connected at the front side to the flange 13. Said flange is fastened to the front wall with screws 42.

[0079] The motor M acts with its drive preferably via KGT on the piston 11 of the pressure supply unit. A double stroke piston, which allows a particularly short construction length, is particularly advantageous here in the case of the piston solution since the piston stroke can be kept low in the case of continuous volume delivery via forward and return stroke. The double stroke piston has two suction valves SV1 and SV2 for forward and return stroke which are connected to the reservoir VB. Only one suction valve is necessary in the case of a single piston. The connections 15 are provided on the front side for the wheel brake cylinders whereby they are optimally accessible. The plug 1 is arranged above the first housing GH1 with preferably lateral outlet 2 of the cable set. A short cable length to the vehicle's electrical system is therefore possible. The reservoir VB extends partially over and beside the plug and on the rear side of the arrangement. This leads to the vehicle's electric system box located in front or behind the spring dome. The foregoing is represented more comprehensibly in FIG. 2a, the view of pedal plunger in direction x.

[0080] The first housing unit GH1 is represented on the right in FIG. 2a which receives the piston cylinder unit 10 (axis H) and the pistons 11 (axis H1) of the pressure supply unit.

[0081] Piston cylinder units 10, 11 are preferably arranged on a vertical axis and the path simulator WS and the switching valves SV1, SV2 are arranged at the shortest possible distance from the valve arrangement HCU which substantially receives the solenoid valves MV and the pressure sensor(s). In accordance with the system design, approx. 10-25 solenoid valves MV are necessary for the ABS/ESP pressure regulation, the controlling of the pressure supply device 11 and the piston cylinder unit 10 and the path simulator WS. To this end, non-return valves must be provided from the piston cylinder unit to the reservoir VB and pressure sensors. Only small hole lengths are necessary due to the arrangement according to the invention when e.g. the solenoid valve MV connected to the path simulator circuit is arranged beside the path simulator piston. Low costs and current resistances are therefore achieved. The control and regulating unit ECU is flanged beside the valve arrangement HCU, the circuit board PCB 25 of said ECU is connected via the coil contacts KSP to the solenoid valve coils. The motor M is also connected with the electric connecting element 12 to the circuit board PCB. This arrangement is described in detail using FIG. 3.

[0082] It has already been mentioned that detail is not given here on the sensor description of pedal path, motor rotation, level of the hydraulic fluid. It should be the aim for all sensor elements to be arranged on the system circuit board PCB 25 and the targets of the sensors to be arranged in proximity to the system circuit board and to be a short distance from the system element (<5 mm). The plug part provided with the contacts is preferably connected here via so-called press-in contacts to the PCB. The plug 1 is inserted laterally with the usual mechanics. It is particularly easily accessible at the point shown in FIGS. 2 and 2a. The reservoir VB has a recess in the plug region 1. The hydraulic consumer connections, in particular wheel brakes 15 can be arranged both on top of one another in the vertical direction and beside one another horizontally. In the case of horizontal arrangement, connection holes must be provided in the first housing.

[0083] The two housing parts GH1 and GH2 can together form a housing or be designed separately.

[0084] The actuation device can be fastened to the front wall of the vehicle by means of the housing flange 13. In this case, so-called front bolted screws can be used easily accessible on the right-hand side and rear bolted screws on the left-hand side of the flange. It is sufficient for e.g. only one screw front bolted to be accessible i.e. from the front of the vehicle. All installation possibilities can therefore be implemented.

[0085] Since, as is well know, any seal can leak and the leakage may no longer appear on the outside, a leakage reservoir 50 can be formed on the underside of the first housing GH1, e.g. combined with 14c.

[0086] The heat from the circuit board PCB and the electronic components can be dissipated via a heat-conducting body 26 to the valve arrangement HCU. The control and regulating unit ECU can be designed flat or, in the case of a larger space requirement for the circuit board, below at right angles.

[0087] To assess the construction space gained, the outline contour of the small vacuum BKV is drawn in here. An additional volume for electric units, such as e.g. a battery results on the right-hand side. This construction space gained is particularly important for right-hand drives since the transversely-located motor requires significant space.

[0088] The path simulator of the brake system with pistons and springs can also be housed in the housing part GH1 or GH2. The path simulator can be arranged axially-parallel to the axis of the main cylinder and also perpendicular thereto.

[0089] The outline contour 52 of the 2-chamber vacuum brake booster with a section of the THZ (e.g. small vacuum booster with 9 diameter) is represented in a dot-dashed manner in FIG. 2. The possible space gained by the arrangement according to the invention is immediately obvious. A construction length gain of almost 50% and in the case of BKV of almost 40% is possible here. The outline contour of the small vacuum BKV with approx. 9 is represented in FIG. 2a as circle 51. The notable construction space gained of the brake booster according to the invention is clear determined by the housing parts GH1 and GH2 with reservoir VB.

[0090] FIG. 3 shows a transverse representation of the motor, drive, the pressure supply device DK, valve arrangement HCU and the control and regulating unit ECU with its essential components. The representation is a mirror image of the representation according to FIG. 2.

[0091] The motor housing 16 is connected via the intermediate part 32 made preferably of sound-damping material to the first housing part GH1, wherein the centring can take place via projection 14b. Motor housing 16 and intermediate part 14 and ECU housing 35 are sealed, e.g. with surfaces shaded at right angles which are not described individually. A four-point bearing 20 is pressed in the motor housing 16 which receives the axial forces in both directions from the spindle 25 and rotor 22 and centres them. The rotor 22 is secured via an axial support 29 and carries the other rotor sheets 19 with magnets 20 in the stator region.

[0092] The rotor 22 is also connected on the front side to a cone gear wheel 28 which drives the second cone gear wheel 29 with shaft 41 and target 38. This acts on the sensor element 37 which evaluates the rotor rotation. The sensor element in this case sits on the system circuit board PCB and is particularly cost-effective and interference-free. Alternatively to the mechanical solution, a solution, not represented, can be implemented in the case of which the rotor, instead of being connected to a cone wheel, is connected to a sleeve which contains the magnets and therefore forms the target 38 for the evaluation of the rotational angle of the motor. The target magnetic field can in this case be detected by corresponding arrangement of the sensor element in proximity to the target (e.g. by plug connection to the ECU) or be guided via magnetic flow conductive elements to the remote sensor element on the PCB.

[0093] The cone gear wheel 29 is mounted in a housing 40 which is connected to the motor housing 16. The gear wheel 29 is mounted in the housing with radial clearance SR so that the flexible drive shaft 41 does not generate any tooth clearance with corresponding tensioning. The shaft is in this case mounted in the bearing bushing 41 which is fastened in the intermediate part 14. The shaft 41 is connected in a torque-proof manner to the gear wheel 29, e.g. via a corresponding profile with rotation lock. The flexible rod BS is fastened on the rotor 22 via the nut 23. It is connected in a torque-proof manner to the spindle 25, e.g. by means of a weld 30. The spindle 25 acts on the KGT nut 26 which is connected in a torque-proof manner to the piston 11 via e.g. a thread 27. In the case of the rotation of rotor and spindle, the radial tolerances cause a spindle impact which generates correspondingly high transverse forces on the piston which are critical for the running surfaces of the seals DK. The bending elasticity of the flexible rod BS reduces this to a small value. This principle can also be applied in the case of a fixed spindle and circumferential nut not represented. The piston is designed here as a stepped piston and provides a short construction length in the case of short stroke. As the sectional drawing illustrates, the construction length is composed of stroke H1+H2=2?H1+L of KGT nut. Since this is inside the motor corresponding to DE 10 2008 063 772 from the applicant, a hollow shaft motor, the actual motor construction length, which is composed of stator and bearing, is not included in the construction length. The clearance of the stroke portion H1 is not used for the leadframe 31 of the winding that is connected to the winding wires. In addition, the motor sensing 28-29 can still be housed here, as already mentioned.

[0094] The piston is sealed via three seals DK in order to seal the corresponding pressure chambers about which no further detail is given, nor the design of the intermediate part 14 and GH1 which is optimal for this purpose.

[0095] The KGT nut with piston requires a rotation lock which is applied on the front side here. A corresponding part 33 with square or multi-edged profile is connected in a torque-proof manner to GH1 and is supported on a slide bearing 34 which is connected in a torque-proof manner to the piston. This sliding guide benefits from the small lubricating effect of the brake fluid. The piston drive can also be designed with fixed spindle and rotating KGT nut. The suction valves SV1 and SV2 are housed on the one side of the GH1 which are connected with corresponding connections to the VB. As indicated in a dot-dashed manner, they can be arranged on the H2 plane in a tubular element. The GH2 HCU is arranged on the opposite side, which, as described, receives the MV and other valves with pressure sensors. Very short connection holes of GH1 and GH2 are clearly discernible above and also below here.

[0096] The ECU housing is connected to the GH2 which receives the PCB with the structural elements BE. The short connection to the motor from leadframe 31 to motor contact KM is also described here, in whose proximity to the PCB are arranged the power contacts of the plug 1 with the BE to the motor controller. The corresponding power loss is dissipated by the PCB via a heat-conducting body to the valve block 56 of the HCU. The ECU housing can be designed parallel and laterally to the motor. This arrangement allows an advantageous compact solution to be implemented cost-effectively which takes into account many requirements.

[0097] FIG. 4 shows in perspective representation particularly clearly the compactness of the arrangement in the embodiment for an E-BKV in the case of which the ABS/ESP unit is arranged outside in the unit compartment. This is why only two hydraulic lines for the two brake circuits of the ABS/ESP unit are labelled with 15a in comparison to four to the wheel brakes in the case of the integrated version, as represented in FIG. 2, 2a. Essential differences in the arrangement of the main components motor with pressure supply corresponding to FIG. 3, housing unit GH1 and GH2 and ECU do not exist for AX5 such that both versions can be modularly built and manufactured. The number of components in ECU, GH2, e.g. solenoid valves and GH3 design of the pistons of the pressure supply only differ with the number of suction valves.

[0098] The plug 1c shows only the so-called male part connected to the ECU. The reservoir is connected only to a suction valve SV1. The second connection THZ with the main cylinder in the housing flange is a screw 42 front bolted for fastening from the front and the other 1 to 3 in the case of 42r are provided as rear bolted.

[0099] FIG. 4a shows the arrangement of the hydraulic circuit board HLP50 between the housing parts GH1 and GH2 which are screwed together. This replaces the many holes and blind stops at the outlet of a hole in the valve block with corresponding channels. They are necessary for connecting the hydraulic lines from e.g. THZ, pressure supply, solenoid valves. The HLP reduces the number, in particular length, and enables a thinner valve block (GH2) which saves weight. For sealing, lip seals D1 or rectangular seals can be used which are preferably injection-moulded to the HLP.