Pressure device having a support element

Abstract

In a pressure device (10, 184), in particular for a hydraulics unit (12) of a vehicle brake system, having a piston (22), guided axially displaceably in a cylinder (40), and a motor (14, 186), which selectively displaces the piston (22) axially in two directions and in which the cylinder (40) is designed to have a receptacle (20) that is arranged in a hydraulics housing (18), has a receptacle opening (28) at its end (26) facing the motor (14, 186), and is partly covered by a support element, wherein a component (73) force-transmittingly coupled to the motor (14, 186) is supported on the hydraulics housing (18) by means of the support element (72) and the support element (72) is held on the hydraulics housing (18), the support element (72) is force-transmittingly coupled to the hydraulics housing (18) by means of a sliding seat (97) for absorbing radial and axial forces occurring during operation.

Description

[0001] Description

[0002] title

[0003] Pressing device with a support element

[0004] State of the art

[0005] The invention relates to a pressure device, in particular for a hydraulic unit of a vehicle braking system, with a piston guided axially displaceably in a cylinder and a motor which can optionally axially displace the piston in two directions, in which the cylinder is designed with a receptacle arranged in a hydraulic housing, which has a receptacle opening at its end facing the motor which is partially covered by a support element, wherein by means of the support element a component coupled to the motor in a force-transmitting manner is supported on the hydraulic housing and the support element is held on the hydraulic housing.

[0006] Known vehicle braking systems are used in motor vehicles, such as cars or trucks, to provide a controlled brake pressure to the associated wheel brakes, which is used to implement slip control, for example. The core of such controllable braking systems is a hydraulic unit with hydraulic components that are conventionally connected to a master brake cylinder. A driver indicates a braking request using a pedal, which is then used to regulate the brake pressure generated by an electric motor via a control unit. A pressure device or external force pressure device operated by the electric motor serves as the external power source for generating brake pressure. As is known, the pressure device is designed as a piston-cylinder unit with a piston guided for displacement in a cylinder and an actuator driven by the electric motor that selectively displaces the piston.The resulting brake pressure is transmitted to the wheel brakes via hydraulic or electromechanical actuators. In such a normal braking situation, the master brake cylinder is decoupled from the wheel brakes and serves to detect the driver's braking request.

[0007] Depending on the vehicle type and size, different types of braking systems with different performance, design, and operating modes are required, along with associated components that may be different or of different sizes. The type of pressure device operated by the electric motor must also be designed accordingly. Furthermore, newer vehicle developments enable driving with increasing levels of automation, which places new demands on the braking system. In particular, pressure generation using an external power source must be particularly reliable and safe to operate, eliminating the need for driver intervention.

[0008] It is an object of the invention to provide a printing device with which a particularly compact and safe construction for pressure generation is created, which can also be manufactured as cost-effectively as possible.

[0009] Disclosure of the invention

[0010] According to the invention, a pressure device or a hydraulic module, in particular an external force pressure device, in particular for a hydraulic unit of a vehicle braking system, is created, with a piston guided axially displaceably in a cylinder and a motor which displaces the piston selectively in two directions and which belongs to an actuator, in which the cylinder is designed with a receptacle arranged in a hydraulic housing or casing, which has a receptacle opening at its end facing the motor, which is partially covered by a support element, wherein by means of the support element a component which is coupled to the motor in a force-transmitting manner and which belongs in particular to the actuator and is preferably a bearing of an actuator element, is supported on the housing and the support element is held on the housing.The support element is coupled, in particular directly, to the housing by means of a sliding seat for transmitting force to absorb radial and axial forces occurring during operation. The sliding seat makes the support element particularly suitable for counteracting radial forces. To create the sliding seat, the support element is slid around the receiving opening and onto the housing, in particular. The support element partially covers the receiving opening, in particular in such a way that an axial opening is provided in the support element. For this purpose, the support element is preferably cup-shaped with a cup base in which the opening is arranged.

[0011] With such a force-transmitting coupling of the support element to the housing according to the invention, particularly extensive support of moments acting radially and also transversely to an associated receiving axis that occur during operation of the printing device is achieved. Transverse means perpendicular and oblique to the receiving axis. This creates a particularly stable and durable attachment of the support element to the housing. Particularly advantageously, the sliding fit has a radially inner contact with the housing on the support element and a radially outer contact with a material of the housing that radially surrounds the support element on the outside. The support element is thus radially supported on both sides by the housing. A particularly extensive force transmission of forces acting on the support element during operation to the housing is achieved. The radially outer contact is preferably achieved by means of a material-forming caulking with the housing that encompasses the support element.

[0012] The support element serves to support a component that is coupled to the motor in a force-transmitting manner and that particularly belongs to the actuator. In this case, the component is in particular a bearing of an actuator element and the support element performs the function of a bearing holder or bearing cover. Preferably, the actuator element is a nut that engages positively in a spindle thread of a spindle and can be rotated by means of the motor or electric motor belonging to the actuator. For this purpose, the nut is rotatably mounted, in particular on its front-end axial region, with a pivot bearing as a bearing. In this way, the bearing, in particular, as a component is coupled to the motor in a force-transmitting manner. When the nut is turned, its rotational movement is converted into an axial movement of the spindle by means of the spindle thread. The spindle thereby displaces a piston coupled to it axially in the pressure direction or pressure build-up direction into the receptacle.In this case, pressure is exerted on a pressure medium located in the holder and in an associated working chamber, which is then forced out of the working chamber. The resulting counterforce is transmitted to the housing via the bearing and the support element. The sliding seat according to the invention ensures particularly extensive force dissipation radially, obliquely and also axially onto the housing. In addition, by reversing the direction of rotation of the motor, the spindle and thus the piston are moved axially in the opposite direction to the support element or in the pressure reduction direction. The reversal of the direction of rotation is made possible in particular by different motor windings. Any forces that arise are transmitted to the housing accordingly. In particular, the housing is designed as a hydraulic block, which can be used to absorb any moments that arise in a stable manner. This makes a pressure device or pressure relief device integrated into the housing possible.A torque-transmitting hydraulic module integrated into the housing was created.

[0013] The pressure device is advantageously designed with a cup-shaped piston which can be moved in the receptacle and in which a spindle which is firmly connected to the piston, i.e. which is axially and rotationally secured, and a nut which surrounds the spindle and can be rotated about the spindle by means of the motor are arranged. The nut is preferably surrounded by the piston for more than half of its length. In addition, the support element is provided which is coupled to the housing in a force-transmitting manner by means of the sliding seat and serves as a holder for a bearing for supporting occurring axial forces and for creating concentricity between the rotationally moving nut and the axially moving spindle. The support element is preferably coupled directly to the housing in a force-transmitting manner or is held on the housing.What's particularly special about this design is that the cylinder is formed directly with the housing's mount, rather than the conventional cylinder sleeve that is housed in the mount. This also ensures direct support of any occurring moments on the housing.

[0014] According to the invention, the sliding seat is advantageously designed with a press fit. For this purpose, the support element is preferably cup-shaped and, in the unassembled state, has a supporting cross-section that is the same as or slightly smaller than the diameter of a housing material surrounding the receiving opening, onto which the support element is then pushed and pressed under pressure. This creates a press fit as a force-locking connection that has a particularly effective force-dissipating effect on radial and transverse forces that occur during operation.

[0015] Furthermore, according to the invention, the sliding seat is advantageously designed for particularly easy installation with a positive fit. For such a positive fit, the support element preferably has at least one hook or tooth on its side facing the housing, which engages the housing in a positive fit. Particularly preferably, several hooks or teeth are provided for this purpose, and most preferably, a toothed rim is created between the support element and the housing material surrounding the receiving opening.

[0016] In addition, according to the invention, the support element is advantageously mounted axially on the hydraulic housing with a contact surface. The contact surface runs transversely to the mounting axis. The contact surface preferably extends obliquely and particularly preferably perpendicular to the mounting axis. The support element is thus supported axially on the housing, absorbs corresponding axially acting forces, in particular from a translational movement of the piston, and transfers these forces axially to the housing. In addition, the contact surface or its respective axial position determines a maximum stroke or displacement of the piston. The pressure device is thus characterized radially by a circular cross-section of the mounting and axially, among other things, by the contact surface against which the support element rests.In particular, the support element is axially mounted on the housing with a contact surface in such a way that the support element has a radially projecting collar that is mounted on the contact surface and is preferably axially caulked radially outward to a material of the housing. Particularly preferably, the collar is axially caulked axially around its entire circumference to the material of the housing. Alternatively, the support element is held radially outward to the housing by means of a clamping element around the collar of the support element. The axial mounting, in particular the caulking or fastening by means of the clamping element, determines and maintains the axial alignment of the pressure device relative to a sun associated with the motor.

[0017] Advantageously, a groove running around the receiving opening is arranged in the housing on a housing side facing the motor, and the support element is cup-shaped with a radially outwardly projecting collar, wherein the collar is received in the groove in such a way that the support element is placed radially inward on a groove cheek of the groove by means of the sliding fit and / or the collar is caulked radially outward to a material of the housing surrounding the groove. The support element is placed with its collar on a groove base belonging to the groove, which serves as the axial contact surface of the support element. This creates not only a particularly stable but also a particularly compact force-transmitting coupling of the support element to the housing. In particular, the support element projects beyond the receptacle in a direction facing away from the motor and into the interior of the housing by means of the groove.This allows an axial area of ​​the sliding seat between the support element and the housing to be used as a displacement space within the mount, parallel to the axis. This utilization creates a generous installation space for the cylinder of the printing device, which is also arranged in a space-saving manner in the direction of the mount and its mounting axis. The mounting axis defines a Y-direction of the housing. This saves installation space in the Y-direction.

[0018] Particularly advantageously, the groove is designed with a small radially outer step, against which a forming tool is positioned to caulk the housing to the support element. This guides the forming tool along a remaining axial, radially outer edge region of a radially outer groove cheek, and the step facilitates caulking.

[0019] Furthermore, according to the invention, the receptacle advantageously has at least one axial anti-rotation groove for receiving a guide element protruding radially from the piston. In this case, the sliding fit is interrupted in particular in the region of the at least one axial anti-rotation groove. Surprisingly, it has been found that, despite such an interruption of the sliding fit, the support element is held firmly on the housing in a force-transmitting manner. At the same time, a space-saving design is achieved in which the individual anti-rotation groove serves to receive a guide element protruding radially from the piston, whereby the piston is secured against undesired twisting in its axial movement. In addition, the individual axial anti-rotation groove is preferably open up to the receiving opening, which is located at the end facing the engine.The support element, in particular with its cup wall, encompasses the individual axial anti-rotation groove in such a way that a radial contact area created by the sliding seat is interrupted in the area of ​​the anti-rotation groove and runs axially parallel outside the area of ​​the anti-rotation groove outside the receptacle. The support element, in particular with its cup wall, and the receptacle thus partially overlap in the axial direction. Such an overlap area is axially parallel within the receptacle and, in a space-saving manner, is also used as displacement. In addition, the at least one anti-rotation groove or longitudinal groove has an axial dimension by which the displacement is limited on its side facing away from the engine. This creates a compact arrangement of the support element and the receptacle in the Y direction, in which the at least one axial anti-rotation groove is preferably compactly encompassed by the support element in the radial direction or in the X and Z directions.

[0020] By means of the at least one axial anti-rotation groove, the receptacle has an associated radial bulge in its cross-section, which determines a maximum outer diameter of the receptacle in its cross-section. The sliding seat preferably has an inner diameter in its cross-section that is equal to the maximum outer diameter, so that the sliding seat is interrupted in the region of the individual anti-rotation groove. Alternatively, the sliding seat preferably has an inner diameter that is smaller than the maximum outer diameter. The at least one axial anti-rotation groove thus extends radially beyond the sliding seat and offers additional space there for receiving and, during an insertion process, in particular the associated guide element protruding radially from the piston.In an alternative preferred embodiment, the sliding seat has an inner diameter that is larger than the maximum outer diameter, thus ensuring that the sliding seat runs particularly stably along the entire circumference of the housing. Such a design is advantageous if sufficient space is available in and on the housing.

[0021] According to the invention, the receptacle advantageously has a receptacle axis that extends perpendicularly between two opposite housing sides of the housing and lies in a first fictitious plane that extends parallel to a reservoir side of the housing adjacent to the two housing sides. The at least one axial anti-rotation groove runs with its groove axis or groove center axis parallel to the receptacle axis, wherein the groove center axis and the receptacle axis lie in a second fictitious plane such that the second fictitious plane is rotated around the receptacle axis with respect to the first fictitious plane at an angle of 10° to 50°, preferably 20° to 40°, and particularly preferably 30°. In particular, the angle is directed counterclockwise with respect to the housing side serving as the motor side.This further optimizes the installation space in the X and Z directions on the engine side, preventing collisions with other components. Two axial anti-rotation grooves are preferably provided, arranged according to the specified angle and diametrically opposite the mounting axis. This also ensures a particularly uniform force application to the housing, preventing rotation of the piston.

[0022] In addition, according to the invention, the support element is advantageously encompassed by a motor housing of the motor, which is fastened to the housing by means of two diametrically opposed fastening points, in particular on the housing side or motor side facing the motor. With only two fastening points, a space-saving fastening of the motor housing and thus of the motor to the motor side is created, which, in combination with the sliding fit of the support element that absorbs radial forces, is nevertheless sufficiently stable. A combination of a radially inner press fit and a radially outer caulking of the support element to the housing has proven particularly advantageous. This creates more space on the motor side and therefore in the X and Z directions for additional components, which enables installation space optimization in the X and Z directions.For further optimization, the two attachment points are located in particular on a fictitious straight line which encloses an angle of 10° to 50°, preferably 20° to 40°, and particularly preferably 30°, with a plane in which a housing side opposite the reservoir side lies. The two attachment points are thus arranged in a row which extends diagonally to the housing side opposite the reservoir side and thus runs diagonally on the motor side. Arranged at an angle in this way, the motor housing can be positioned on the motor side particularly far towards a corner of the motor side in a space-saving manner. Sufficient space must only remain for a flange which radially surrounds the motor housing and is attached to the motor side. A seal is preferably provided between the flange and the motor side to prevent moisture from penetrating the motor housing.In particular, the motor housing is designed in a cup shape with a radially circumferential flange that has two diametrically opposed tabs, each of which is screwed to the motor side with a screw.

[0023] According to the invention, the receptacle advantageously has a further receptacle opening at its end facing away from the engine, which is closed by a cup-shaped cylinder cover. In particular, the receptacle has a radial sealing groove between the axial anti-rotation groove and the further receptacle opening, in which a piston seal encompassing the piston is received, preferably in such a way that a working chamber enclosed by the receptacle, the cup-shaped cylinder cover, the piston seal and the piston has no access to a reservoir to be arranged on the housing. By virtue of this lack of access to the reservoir, particularly in the rest or zero position of the piston, more effective use of the displacement is achieved and thus a further reduction in installation space in the Y direction. There is no dead stroke and the associated cylinder volume can be fully utilized, so to speak, gross equal to net.Preferably, pressure equalization in the rest position is then enabled by means of a control valve connected to the working chamber, which is designed as a normally closed solenoid valve, in particular with a hydraulic overflow function.

[0024] In particular, a further radial sealing groove is advantageously provided in the receptacle axially between the axial anti-rotation groove and the radial sealing groove, and a radial guide groove is arranged axially between the two sealing grooves, which guide groove is connected to a pressure medium that is in particular at atmospheric pressure. The guide groove is preferably arranged concentrically to both sealing grooves and serves to connect a pressure-free area to a pressure medium, preferably from the reservoir or from other pressure-free cavities in the housing in which a pressure medium is in particular at atmospheric pressure. For this purpose, the guide groove is preferably connected to the reservoir, in particular in such a way that a region of the guide groove facing away from the piston is radially or obliquely cut into, but not penetrated by, a line connected to the guide groove. This ensures pressure-free equalization of the pressure medium in an area between the two sealing grooves.The sealing groove facing the working chamber accommodates the piston seal, which acts as a high-pressure seal, and the sealing groove facing away from the working chamber accommodates a piston seal, which serves as an isolation seal in a low-pressure area there. The guide groove ensures that both piston seals on a side facing away from the pressure are moistened during operation. This lubricates the piston seals lying on the piston circumference and causes less frictional resistance on the piston, reducing wear. In addition, an annular guide element is preferably accommodated in the guide groove, which projects radially beyond the receptacle slightly so that the piston is guided with a certain amount of play at a distance from the receptacle.

[0025] Furthermore, according to the invention, the working chamber is advantageously fluidically connected by means of at least one axial inlet and outlet flow, each to an associated control valve of an associated brake circuit. For this purpose, a line opening for the at least one inlet and outlet flow is preferably provided radially outwardly close to the receiving opening in the housing side serving as the control unit side. In particular, an axial line section leads from the individual line opening into the housing to a line section which preferably runs transversely to the receiving axis and is connected to the associated control valve. Preferably, a groove is arranged in the control unit side which radially surrounds the receiving opening and in which the individual line opening is arranged. In addition, a housing shoulder is formed between the groove and the receiving opening, around which the cylinder cover is pressed onto its inner cup wall.The radially inner press fit thus formed is only slightly interrupted by the respective inflow and outflow. In this case, the cylinder cover in particular has a radially outwardly projecting collar which is caulked radially on the outside with a material of the housing and is thus reliably held on the housing. Accordingly, when the piston is pushed in towards the cylinder cover or into the working chamber, pressure medium can be axially pushed out of the working chamber through the line opening, or when the piston is moved out, pressure medium can be sucked axially through the line opening into the working chamber. This enables a particularly compact inflow and outflow of pressure medium. In addition, a suction inflow of pressure medium from the reservoir into the working chamber advantageously takes place by means of a recess on one of the at least one axial inflow and outflow of the working chamber, the cutout increasing the cross-section of the inflow and outflow.The recess is preferably kidney-shaped, and the described interference fit is interrupted more by the recess than by the line opening alone. This creates a simple, effective reduction of backpressure for compensating filling or refilling in a so-called single-box brake system, in which an actuation and modulation unit for brake pressure is housed in a single housing.

[0026] In addition, according to the invention, the support element advantageously belongs to a projection element which is adapted to be designed identically across multiple printing device types with regard to its projection from the housing, and the receptacle is adapted to be designed with a different axial dimension across multiple printing device types. The projection is defined by an axial and radial extension protruding from the housing. In particular, the projection is designed identically, at least with its axial extension, across multiple printing device types. Preferably, the projection is also designed identically with its radial extension across multiple such types. Particularly preferably, the support element and / or the projection element are designed to be completely identical in construction, thereby achieving cost-effective volume effects. The support element is preferably encompassed by a cover element in which further transmission components are arranged.In this case, the cover element, in addition to the support element, is preferably designed identically across multiple printing device types with regard to its projection from the housing. The support element and the cover element together form the projection element, which is designed identically across multiple printing device types with regard to its projection and is preferably completely structurally identical.

[0027] In other words, the invention advantageously provides a printing device series comprising at least two printing device types, each designed with a projection element belonging to the support element and a receptacle. The projection elements belonging to the support element are identical in construction for the at least two printing device types, and the receptacles are designed differently in terms of their axial dimensions for the at least two printing device types.

[0028] Such a design enables simple, cost-effective, and at the same time particularly easy-to-install adaptation of such pressure devices to different types of associated vehicle braking systems. The inventive receptacle can be easily varied in terms of its axial dimension. In particular, the axial dimension of the receptacle can be varied by varying the thickness of the associated housing. The housing thickness extends between the engine side and an opposite control unit side of the housing, on which an electronic control unit controlling the engine is to be arranged, and the receptacle is guided with its axial extension from the engine side to the control unit side. Simply by varying the housing thickness, different variants of receptacle lengths and thus also different variants of the resulting cylinder lengths are possible.Different cylinder lengths require different printing device volumes, each with its own associated performance. This requires only minor adjustments to the mount and, if necessary, to a very few other components. The support element, preferably the overhang element, and preferably other components are designed identically. This results in higher production runs and advantageous economies of scale.

[0029] According to the invention, the receptacle advantageously has at least one axial anti-rotation groove for accommodating a guide element projecting radially from the piston, wherein the at least one anti-rotation groove is designed with a different axial dimension across multiple pressure device types. This allows for easy adaptation to the receptacles, each with a different axial dimension.

[0030] Another very simple adaptation is advantageously achieved according to the invention in that the receptacle has at least one radial sealing groove for receiving a respective piston seal, wherein the at least one sealing groove is arranged at a respective different axial position in the receptacle across a plurality of pressure device types. Furthermore, according to the invention, the projection element belonging to the support element is advantageously encompassed by a motor housing of the motor, which is adapted to be designed with a different axial dimension across a plurality of pressure device types in accordance with an engine class or engine power belonging to the engine. This creates a modular concept for receiving a gear belonging to the actuator in the motor housing with the same projection for different receptacle lengths or cylinder lengths and brake systems. Furthermore, with the same projections of the support elements orProjection elements provide a uniform interface to the motor across multiple pressure device types. This enables easy interchangeable use of different motor classes in a braking system, while maintaining the same gear projection at a reasonable cost. This ensures interchangeable motor compatibility.

[0031] Furthermore, according to the invention, the receptacle advantageously has a further receptacle opening at its end facing away from the engine, which opening is closed by the cup-shaped cylinder cover. The cylinder cover is adapted to be structurally identical across multiple pressure device types. This means that the same cylinder cover is always covered by a respective control unit on the control unit side in such a way that a circuit board of the control unit is not affected, regardless of the pressure device type used. Different displacement volumes are realized solely due to the different axial dimensions of the receptacle and thus the different housing thicknesses. The receptacle extends from the engine side to the control unit side and projects through each associated housing type with its housing thickness.

[0032] Overall, this creates a pressure device as an integrated hydraulic module for converting electrical into hydraulic power with a stable axial mounting, which simultaneously achieves housing-side and space-optimized torque support. Furthermore, it enables modular expansion with respect to different braking systems, different volumes, and motor sizes. This allows for the necessary adaptations and requirements of different pressure device types to be varied while still being as cost-effective to manufacture as possible. Accordingly, the invention is also directed to the use of such a pressure device in a hydraulic unit of various hydraulic unit types of a respective vehicle braking system.This makes it particularly cost-effective to use identical elements in a variety of different hydraulic unit types, such as the aforementioned one-box system of a so-called Integrated Power Brake (IPB) or for an actuation unit of a two-box system of a Decoupled Power Brake (DPB), in which the actuation and modulation units of the brake pressure are arranged in two different housings, or for other pressure generation systems.

[0033] In the following, exemplary embodiments of the inventive solution are explained in more detail with reference to the attached schematic drawings. It shows:

[0034] Fig. 1 is a schematic longitudinal section of a first embodiment of a printing device according to the invention,

[0035] Fig. 2 the detail II according to Fig. 1,

[0036] Fig. 3 shows the detail III according to Fig. 1 during a caulking process, Fig. 4 shows a perspective partial view of a hydraulic housing belonging to a second embodiment,

[0037] Fig. 5 shows the section VV according to Fig. 1 of the second embodiment, Fig. 6 shows the view VI according to Fig. 1 of a hydraulic unit belonging to the embodiments,

[0038] Fig. 7 shows a comparative longitudinal section of a third and fourth embodiment of two types of printing devices according to the invention,

[0039] Fig. 8 shows the view according to Fig. 3 of a fifth embodiment of a printing device according to the invention,

[0040] Fig. 9 shows the view IX according to Fig. 1 without cylinder cover of a first variant of an inflow and outflow of pressure medium and

[0041] Fig. 10 the view according to Fig. 9 of a second variant of an inflow and outflow of pressure medium.

[0042] Figs. 1 and 2 illustrate a pressure device 10 of a hydraulic unit 12 (shown in detail) for an electrohydraulic vehicle braking system (not shown in detail) or braking system (not shown) intended for a four-wheeled vehicle (not shown). The braking system is intended to fulfill the functions of an anti-lock braking system (ABS), an electronic stability program (ESP), and / or a traction control system (ASR), as well as functions for at least partially autonomous driving.

[0043] The pressure device 10 is designed as a plunger device that is driven by an electric motor or motor 14 (only a part of which is shown). The motor 14 is part of an actuator 16 and represents an external power drive of the braking system, which is part of a power-driven vehicle braking system. The motor 14 and the pressure device 10 serve as brake pressure generators for generating braking pressure at the associated wheel brakes and form an external pressure source in the braking system. The braking system is designed here as a brake-by-wire braking system, with which the energy required for braking pressure is provided, at least in a normal braking situation, by the motor 14 and not by the driver's muscle power.

[0044] In detail, the hydraulic unit 12 has a hydraulic housing 18 or casing 18 (only partially shown), which is designed as a hydraulic block. Arranged in the housing 18 is a receptacle 20 designed as a stepped bore, which represents a so-called external power cylinder receptacle. Received therein is a piston 22 which serves as an external power piston and is designed as a plunger or plunger piston. The receptacle 20 extends axially completely through the housing 18 with its receptacle axis 24 or Y-axis coinciding with the piston axis. The receptacle 20 is designed with an open receptacle opening 28 at a first end 26 facing the motor 14 or actuator 16. The receptacle opening 28 is thus located in a housing side 30 facing the motor 14 or actuator 16, which serves as the motor side for connecting the motor 14. In addition, the receptacle 20 is provided with a recess 32 at its end facing the motor 14 or actuator 16.The second end 32 facing away from the actuator 16 is designed with a further receiving opening 34, which thus projects into a housing side 35 opposite the housing side 30 and serves as the control unit side.

[0045] On the housing side 35, the receiving opening 34 is closed in a fluid-tight manner by a cup-shaped cylinder cover 36 arranged coaxially to the receiving element 20, thus extending the receiving element 20. The cylinder cover 36 therefore has a projection 37 which projects radially and axially from the housing side 35. In addition, the cylinder cover 36 has a collar 38 which projects radially outwards and is caulked to the housing 18. With the cylinder cover 36 and the receiving element 20, a cylinder 40 is designed as a plunger cylinder, in which the piston 22 is guided so as to be axially displaceable along its axis or the receiving axis 24. The cylinder 40 is therefore partly formed directly with the receiving element 20 and integrated into the housing 18. Inside the cylinder 40 there is a working chamber 42 which is filled with pressure medium or fluid. The working chamber 42 orThe pressure chamber is sealed with a piston seal 46 arranged in a radial sealing groove 44 provided in the receptacle 20 between the piston 22 and the housing 18.

[0046] The piston seal 46 is a high-pressure seal for sealing a high-pressure area 48 defined by the working chamber 42. A further piston seal 52 is provided in a further radial sealing groove 50 of the receptacle 20, facing away from the working chamber 42 and enclosing the piston 22. This piston seal 52 serves as an insulation seal for sealing off any leaks that may occur at the high-pressure seal and ensures a dry area in the direction of the motor 14. Axially between the two piston seals 52 and 46, a radial guide groove 53 is provided with a T-shaped cross-section. The guide groove 53 is intersected at its groove base by a line 54 in the form of a bore, which is connected to a reservoir 55 or

[0047] Brake fluid reservoir is connected to the brake fluid reservoir in a pressure-conducting manner. This creates a low-pressure area 56 or pressure-free area between the two piston seals 46 and 52, in which the pressure medium is at atmospheric pressure. The pressure medium present there and the pressure-conducting connection of the line 54 to the reservoir 55 ensure that the two piston seals 46 and 52 are always moistened. In addition, pressure medium is located axially on both sides of the piston seal 46, which is therefore a particularly low-wear wet-on-wet seal. An annular guide element 57 is arranged in the guide groove 53, which projects slightly radially into the receptacle 20 and circumferentially encompasses the piston 22. The piston 22 is thus guided at a corresponding distance from the receptacle 20, thus preventing friction and jamming of the piston 22 with the receptacle 20 (detailed in Fig. 2).

[0048] From the working chamber 42, the fluid is displaced by means of the piston 22 through a fluid-conducting inflow and outflow 58, shown in Fig. 9, into at least one brake line 59 of at least one brake circuit (not shown) to generate pressure at the associated wheel brakes. In this case, the working chamber 42 has no access to the reservoir 55. Pressure equalization in the rest position of the piston 22 is preferably enabled by a control valve 60 coupled to the inflow and outflow 58 (Fig. 9), which preferably has a hydraulic overflow function (not shown).

[0049] The piston 22 is held on the outside by means of at least one radially projecting, wing-like guide element 61 in a rotationally fixed and simultaneously axially displaceable manner in an associated axial anti-rotation groove 62, in which the individual guide element 61 engages. The anti-rotation groove 62 is formed as a longitudinal groove on the region of the receptacle 20 facing the motor 14, parallel to the receptacle axis 24 in the block-shaped housing 18. Thus, the piston 22, with the guide element 61 in cooperation with the anti-rotation groove 62, is supported against rotation and radial movement relative to its piston axis or the receptacle axis 24.

[0050] Furthermore, a spindle 64 is accommodated inside the cup-shaped piston 22, which has a circular cross-section and is connected to the piston 22 in an axially and rotationally secure manner. The spindle 64 is surrounded by a hollow cylindrical nut 66, which positively engages on the outside in a spindle thread 68 formed on the spindle 64. Balls serving as rolling bearings are preferably provided between the spindle 64 and the nut 66 (not shown). The nut 66 is surrounded on the end face facing the motor 14 by a bearing 70 designed as a pivot bearing, which is held on the outside by a cup-shaped support element 72 fixedly coupled to the housing 18. The nut 66, which is rotatably mounted by the bearing 70, can be rotated by means of the motor 14, wherein the rotational movement via the spindle thread 68 leads to a displacement of the spindle 64 and thus of the piston 22 in the cylinder 40.Thus, the bearing 70 is a component 73 belonging to the actuator 16, and the nut 66 is an actuator element 74, which, together with the motor 14 and the spindle 64, belong to the actuator 16, with which the piston 22 can be selectively displaced in the cylinder 40. The piston 22 is shown in its retracted state in Fig. 1. If the piston 22 is moved completely in the direction of the cylinder cover 36 by means of the actuator 16, the piston 22 is in the extended state. When extended in the pressure direction 75, the piston 22 displaces pressure medium from the working chamber 42. In addition, the actuator 16 includes a gear 76, which is preferably designed as a planetary gear. For this purpose, a drive element 80 designed as a sun gear is provided, which is coupled to a motor shaft 78 of the motor 14. Preferably, three planetary gears 82 engage therein, which are surrounded by a ring gear 83. The gear 76 designed in this way is arranged axially outside the support element 72.For this purpose, the support element 72 has a central opening 84, which is coaxial with the piston 22. Elements 88 projecting axially from the nut 66 are guided through the opening 84, each of which is encompassed by a planetary gear 82. The opening 84 has a circular cross-section and is located in the cup-shaped support element 72's cup base 86, which faces the motor 14.

[0051] With its cup bottom 86 and its associated cup wall 89, the support element 72 engages around the bearing 70 designed as a ball bearing. The cup wall 89 is designed axially opposite the cup bottom 86 with a radially outwardly projecting collar 90 that is caulked to a material 92 of the housing 18. In addition to a radially outer caulking 94 formed in this way, the support element 72 with its cup wall 89 is pushed radially inward around a shoulder 96 of the housing 18, thereby forming a sliding seat 97 that absorbs radial forces occurring during operation. In this case, the support element 72 is pressed around the shoulder 96 so that the sliding seat 97 is designed with a radially inner press fit 98. The support element 72 thus serves as a bearing holder and has a first projection 100 from or to the housing 18. The first projection 100 is determined by a first axial extension 102 and a first radial extension 104.

[0052] Axially in the direction of the motor 14, the support element 72, together with the gear 76 and its gear components, is covered by a cup-shaped cover element 106, which in turn has a coaxial opening 110 in its cup bottom 108 through which the motor shaft 78 is passed. On its open side, the cover element 106 is attached to the housing side 30 with its cup wall 112. The cover element 106 is thus a gear cover, which in other, not shown embodiments can also be attached to the support element 72 with its cup wall 112 and not to the housing 18. The cover element 106 thus has a second projection 114 from the housing 18, which in its second axial extent 116 and second radial extent 118 is greater than the first projection 100.Thus, the cover element 106 and the support element 72 together form a projection element 120, with which the second projection 114 from the housing 18 is fixed, which is the entire projection 114 encompassed by a cup-shaped motor housing 122.

[0053] The motor housing 122 accommodates the motor 14, designed as an electric motor, axially downstream of the cover element 106, opposite the support element 72. Furthermore, the motor housing 122 has a radially projecting flange 126 on its cup wall 124 facing away from the motor 14. Two diametrically opposed tabs 128 are formed on the flange, through each of which a screw 130, preferably designed with an M5 thread, is screwed into the housing 18. This creates two diametrically opposed fastening points 132, with which the motor housing 122 is attached to the housing side 30 in a very space-saving manner (see also Fig. 6).

[0054] Fig. 3, 4 and 5 show in detail that for fastening the support element 72 to the housing side 30, a groove 134 is provided which projects into the block-shaped housing 18 and runs around the receiving opening 28. Thus, the aforementioned shoulder 96 is formed radially between the groove 134 and the receiving opening 28 of the housing 18. The shoulder 96 is formed externally by an inner groove cheek 136 belonging to the groove 134, onto which the support element 72 is pressed with its radially inner cup wall 89, forming the sliding seat 97 designed as a press fit 98. Furthermore, the groove 134 has a step 140 on its radially outer groove cheek 138, onto which a forming tool 142 is applied for caulking the housing 18 to the collar 90 (see Fig. 3). In this case, the material 92 surrounding the housing 18 is formed over the collar 90 and the caulking 94 is formed.

[0055] The inner groove cheek 136 forms an axial region of the sliding seat 97 or axial radial contact region 144, which is an axial press region by means of the press fit 98. The axial radial contact region 144 extends as far as a contact surface 145, against which the support element 72 is axially seated. The contact surface 145 extends essentially perpendicular to the receiving axis 24 and is formed by the groove base of the groove 134. The axial radial contact region 144 thus overlaps axially with the receptacle 20. Such an overlap region is axially parallel within the receptacle 20 and, in a space-saving manner, is also used as a displacement space 146 for a stroke of the piston 22 (see Fig. 1). The support element 72 and the receptacle 20 are thus arranged very compactly, overlapping one another along the receiving axis 24 or in the Y direction. The sliding seat 97 and thus the axial radial contact area 144 are interrupted by at least one anti-rotation groove 62 (see also Fig. 1).

[0056] Fig. 3, 4 and 5 show an embodiment in which, with respect to the receiving axis 24, two diametrically opposed axial anti-rotation grooves 62 are provided as longitudinal grooves in the receptacle 20. A guide element 61 projecting radially from the outside of the piston 22 is received in each anti-rotation groove 62. Designed in this way, the sliding seat 97, in the assembled state (see Fig. 5), is interrupted at two diametrically opposed regions of the anti-rotation grooves 62. In the region of the anti-rotation grooves 62, the receptacle 20 has a radial bulge 148, which defines a maximum outer diameter 150 of the receptacle 20 in its cross-section. The sliding seat 97 has a radial inner diameter 152 in its cross section which is smaller than the maximum outer diameter 150 of the receptacle 20, but larger than a receptacle diameter 154 in the cross section of the receptacle 20 without taking into account any radial bulge 148.Thus, the at least one axial anti-rotation groove 62 extends radially beyond the sliding seat 97 and provides additional space there, particularly as clearance for the associated guide element 61. Furthermore, the axial radial contact area 144 runs parallel outside the receptacle 20 and coaxial with the receptacle 20, so that the support element 72 with its cup wall 89 and the receptacle 20 partially overlap in the axial direction. Thus, the axial overlap area can also be used at least partially as displacement space 146 in the axial extension, creating an axially compact cylinder 40 (see Fig. 1).

[0057] In addition, the described sliding seat 97, which is designed as a press fit 98, and the caulking 94 create a stable and force-transmitting attachment of the support element 72 to the housing 18, with which moments and torques of forces occurring during operation are transmitted directly to the housing 18 in a comprehensive and stabilizing manner and are diverted from there (indicated by arrows in Figs. 1 and 5). By rotating the nut 66, the spindle 64 and thus the piston 22 coupled to it are moved axially into the working chamber 42 in the pressure direction 75 (large arrow). This generates a counterforce, indicated by small arrows and shown only schematically, which is transmitted in particular axially to the piston 22 and the spindle 64 coupled to it, and axially, radially and obliquely via the nut 66 to the bearing 70 and from there to the support element 72.The counterforce is transmitted radially, obliquely and axially from the support element 72 to the housing 18 by means of the sliding seat 97 and is countered by the latter.

[0058] To optimize the available installation space in the housing 18, and in particular on the housing side 30 serving as the motor side and extending in the X direction 156 and the Z direction 158, the two anti-rotation grooves 62 with their groove center axes 160 are not arranged parallel to a housing side 162 adjacent to the two housing sides 30 and 35 and opposite the reservoir 55, but rather obliquely thereto. As shown in detail in Fig. 5, a first fictitious plane 163 is present, which encloses the receiving axis 24 and extends parallel to the housing side 162 and to a reservoir side 164 opposite the housing side 162 (see Fig. 6). Furthermore, each groove center axis 160 is arranged such that a second fictitious plane 165 is formed between the groove center axis 160 and the receiving axis 24, which intersects the first fictitious plane 163 at an angle 166. In this case, the angle 166 is approximately 30°.

[0059] Fig. 6 shows the associated hydraulic unit 12 in the assembled state, looking towards the housing side 30 which serves as the motor side. Adjacent to the housing side 30 is a fastening side 167, to which the hydraulic unit 12 is to be fastened to a vehicle wall (not shown) by means of a fastening 168. In Fig. 6, the described fastening of the motor 14 by means of two diametrically opposed fastening points 132 is clearly visible. The fastening points 132 lie on a fictitious straight line 169 which forms an angle 172 of approximately 30° with a plane 170 in which the housing side 162 lies. The angle 172 is approximately equal to the angle 166, so that the fastening points 132 are located in a radial extension of the two anti-rotation grooves 62 for particularly good force transmission.In addition, the motor housing 122 is arranged on the housing side 30 serving as the motor side in a corner formed by the housing side 182 and the fastening side 167, as far as the flange 126 projecting radially from the motor housing 122 allows. This creates space on the housing side 30 and in the housing 18 for additional receptacles not shown here. The flange 126 is required in its entirety to enclose a full-circumference seal (not shown) between the flange 126 and the housing 18. In addition, the associated tab 128, on the right in Fig. 6, is pulled downward in the direction of the housing side 162 to save space.

[0060] Fig. 7 shows at the top an embodiment of the printing device 10 as a first printing device type 10 or first type of printing device 10 with a first axial dimension 173 of the receptacle 20 and the support element 72 with its first projection 100 and the highly schematically illustrated cover element 106 with its second projection 114. The second projection represents the entire projection 114 of the projection element 120 formed with the cover element 106 and the support element 72. In addition, the motor housing 122, also highly schematically illustrated, is shown with its associated first axial dimension 174. The first axial dimension 173 of the receptacle 20 corresponds to a first housing thickness 176 of the housing 18 extending between the two housing sides 30 and 35. The available volume or pressure volume of the cylinder 40 is determined by the first axial dimension 173 of the receptacle 20, the associated receptacle diameter 154 and the cup-shaped cylinder cover 36.

[0061] Furthermore, the associated at least one axial anti-rotation groove 62 has a first axial dimension 178 (shown only in Fig. 1). In addition, the radial sealing groove 44 is arranged at a first axial position 180 and the radial sealing groove 50 is arranged at an associated first axial position 182 in the receptacle 20.

[0062] In comparison to the first pressure device type 10, Fig. 7 below shows a second pressure device type 184 or second type of pressure device 184, which has a larger volume of the associated cylinder 40 and thus a greater output. Structurally, the second pressure device type 184 differs only slightly from the first pressure device type 10. Both the support element 72 with its first projection 100, as well as the cover element 106 and the projection element 120 with its second projection 114, are designed and attached in the same way. Thus, the entire projection 114 from the housing side 30 serving as the motor side is designed the same. With the same projection 114, an identical engagement depth of the motor shaft 78 in the gear 76 or its sun gear and from the gear 76 to the motor 14 is created. This provides a uniform interface to the motor across multiple pressure device types 10, 184.Depending on requirements, a motor 186 with higher power can be mounted on the uniform interface, the motor housing 188 of which simply has a larger second axial dimension 190 than the corresponding first axial dimension 174 of the first pressure device type 10.

[0063] Furthermore, the cup-shaped cylinder cover 36 is designed and secured identically in both printing device types 10, 184. Thus, the cylinder cover 36 also has a uniform projection 37, which also creates a uniform interface on the housing side 35 serving as the control unit side without affecting a circuit board of a respective associated control unit 192.

[0064] In contrast to the first pressure device type 10, the associated housing 18 of the second pressure device type 184 is designed with a larger second housing thickness 194. Accordingly, the receptacle 20 associated with the second pressure device type 184 has a larger second axial dimension 196 than the first axial dimension 173. Furthermore, the associated axial anti-rotation groove 62 has a second axial dimension (not shown) that is longer than the first axial dimension 178. Furthermore, a second axial position 198 associated with the radial sealing groove 44 is arranged further in the direction of the cylinder cover 36 than the corresponding first axial position 180. Furthermore, a second axial position 200 associated with the radial sealing groove 50 is also arranged further in the direction of the cylinder cover 36 than the corresponding first axial position 182.At the same time, with the larger second housing thickness 194, a receiving area 202 remains from the sealing groove 44 and the piston seal 46 arranged therein in the direction of the cylinder cover 36. The receiving area 202, together with the cylinder cover 36, creates a working chamber 204 of the second pressure device type 184 within it, which is larger than the working chamber 42 of the first pressure device type 10. The respective receiving diameter 154 is designed identically. Thus, a different plunger volume or pressure device volume is created simply by varying the housing thicknesses 176, 194 or the axial dimensions 173, 196 of the receptacle 20. The cylinder 40 is designed in two parts, with a cylinder cover 36 that is always identical in construction and a holder 20 with different axial dimensions 173, 196. Different brake systems can therefore be designed cost-effectively with always the same closure elements, such as the cylinder cover 36 and the support element 72.

[0065] Fig. 8 shows a detail of an embodiment in which the support element 72 is held on the housing 18 by means of a sliding seat 97 designed with a positive fit 206. For this purpose, the cup wall 89, opposite the cup bottom 86, is designed with at least one hook 208 facing radially inward at an angle and engaging positively with the housing 18. The at least one hook 208 forms a contact surface 145 extending obliquely to the receiving axis 24, against which the support element 72 is axially seated. In addition, the radial contact area 144 of the support element is formed by the cup wall 89 and each hook 208.

[0066] Fig. 9 shows a partial plan view of the housing side 35 serving as the control unit side, without the cylinder cover 36 mounted over the receiving opening 34. A groove 210 radially surrounding the receiving opening 34 and projecting into the housing side 35 is provided, forming a housing shoulder 212. In the assembled state, the cylinder cover 36 is pressed around the housing shoulder 212, so that an interference fit is formed on an inner groove wall 214 belonging to the groove 210. The interference fit is slightly interrupted at two diametrically opposite points by an axial inflow and outflow 58, which is formed as an axial opening in the groove 210. From each inflow and outflow 58, a line section 216 leads to the associated control valve 60 of the associated brake line 59.

[0067] Fig. 10 shows a variant in which, in contrast to Fig. 9, one of the two inflow and outflow lines 58 has a kidney-shaped recess 218 that enlarges its cross-section. The kidney-shaped recess 218 is connected to the reservoir 55 (not shown) for a suction inflow of pressure medium from the reservoir 55.

Claims

Claims 1. Pressure device (10, 184), in particular for a hydraulic unit (12) of a vehicle braking system, with a piston (22) guided axially displaceably in a cylinder (40) and a motor (14, 186) which can displace the piston (22) axially in two directions as desired, in which the cylinder (40) is designed with a receptacle (20) arranged in a hydraulic housing (18), which receptacle has, at its end (26) facing the motor (14, 186), a receiving opening (28) which is partially covered by a support element (72), wherein a component (73) coupled to the motor (14, 186) in a force-transmitting manner is supported on the hydraulic housing (18) by means of the support element (72), and the support element (72) is held on the hydraulic housing (18), characterized in that the support element (72) is designed by means of a sliding seat (97) for receiving during during operation, is coupled to the hydraulic housing (18) in a force-transmitting manner to transmit radial and axial forces occurring.

2. Printing device according to claim 1, characterized in that the sliding seat (97) is designed with a press fit (98).

3. Printing device according to claim 1 or 2, characterized in that the sliding seat (97) is designed with a positive fit (206).

4. Printing device according to one of claims 1 to 3, characterized in that the support element (72) is placed axially on the hydraulic housing (18) with a contact surface (145), in particular in such a way that the support element (72) has a radially projecting collar (90) which is placed on the contact surface (145) and is preferably provided radially on the outside with a Material (92) of the hydraulic housing (18) is caulked or is held around the collar (90) of the support element (72) by means of a clamping element.

5. Printing device according to one of claims 1 to 4, characterized in that the receptacle (20) has at least one axial anti-rotation groove (62) for receiving a guide element (61) projecting radially from the piston (22) and in particular in the region of the at least one axial anti-rotation groove (62) the sliding seat (97) is interrupted.

6. Printing device according to claim 5, characterized in that the receptacle (20) has a receptacle axis (24) which extends perpendicularly between two opposite housing sides (30, 35) of the hydraulic housing (18) and lies in a first fictitious plane (163) which extends parallel to a reservoir side (164) of the hydraulic housing (18) adjacent to the two housing sides (30, 35), and the at least one axial anti-rotation groove (62) runs with its groove central axis (160) parallel to the receptacle axis (24), wherein the groove central axis (160) and the receptacle axis (24) lie in a second fictitious plane (165) such that the second fictitious plane (165) is inclined relative to the first fictitious plane (163) at an angle (166) of 10° to 50°, preferably of 20° to 40° and particularly preferably of 30° around the Mounting axis (24) is rotated.

7. Printing device according to one of claims 1 to 6, characterized in that the support element (72) is encompassed by a motor housing (122, 188) of the motor (14, 186), which is fastened to the hydraulic housing (18) by means of two diametrically opposed fastening points (132) and in particular the two fastening points (132) lie on a fictitious straight line (169) which encloses an angle (172) of 10° to 50°, preferably of 20° to 40° and particularly preferably of 30°, with a plane (170) in which a housing side (162) opposite the reservoir side (164) lies.

8. Printing device according to one of claims 1 to 7, characterized in that the receptacle (20) has at its end (32) facing away from the motor (14) a further receiving opening (34) which a cup-shaped cylinder cover (36) is closed, and in particular the receptacle (20) has a radial sealing groove (44) between the axial anti-rotation groove (62) and the further receiving opening (34), in which a piston seal (46) encompassing the piston (22) is received, preferably in such a way that a working chamber (42, 204) enclosed by the receptacle (20), the cup-shaped cylinder cover (36), the piston seal (46) and the piston (22) has no access to a reservoir (55) to be arranged on the hydraulic housing (18) and in particular in the receptacle (20) axially between the axial anti-rotation groove (62) and the radial sealing groove (44) a further radial sealing groove (50) is provided and axially between the two sealing grooves (44, 50) a radial guide groove (53) is arranged, which is connected to pressure medium.

9. Printing device according to claim 8, characterized in that the working chamber (42, 204) is fluidly connected by means of at least one axial inflow and outflow (58) to a respective control valve (59) of an associated brake circuit.

10. Printing device according to claim 8 or 9, characterized in that a suction inflow of pressure medium from the reservoir (55) takes place by means of a recess (218) which enlarges the inflow and outflow (58) in its cross section at one of the at least one axial inflow and outflow (58) of the working space (42, 204).

11. Printing device according to one of claims 1 to 10, characterized in that the support element (72) belongs to a projection element (120) which is adapted to be designed identically across several printing device types (10, 184) with regard to its projection (114) from the hydraulic housing (18) and the receptacle (20) is adapted to be designed with a different axial dimension (173, 196) across several printing device types (10, 184).

12. Printing device according to claim 11, characterized in that the receptacle (20) has at least one axial anti-rotation groove (62) for receiving a respective guide element (61) projecting radially from the piston (22), wherein the at least one Anti-rotation groove (62) is designed with a different axial dimension (178) across several pressure device types (10, 184).

13. Printing device according to claim 11 or 12, characterized in that the receptacle (20) has at least one radial sealing groove (44, 50) for receiving a respective piston seal (46, 52), wherein the at least one sealing groove (44, 50) is arranged across a plurality of printing device types (10, 184) at a respectively associated different axial position (180, 182, 198, 200) in the receptacle (20).

14. Printing device according to one of claims 11 to 13, characterized in that the support element (72) is encompassed by a motor housing (122, 188) of the motor (14, 186), which is adapted to be designed with a different axial dimension (174, 190) across several printing device types (10, 184) in accordance with a motor power associated with the motor (14, 186).

15. Printing device according to one of claims 11 to 14, characterized in that the receptacle (20) has, at its end (32) facing away from the motor (14, 186), a further receptacle opening (34) which is closed by a cup-shaped cylinder cover (36), and the cylinder cover (36) is adapted to be of identical design across several types of printing devices (10, 184).

Images