Hydraulic unit

Abstract

Hydraulic unit (10) with a control unit housing (14) carrying electrical valve components (12), a hydraulic block (18) carrying hydraulic valve components (16), a device (20) for connecting the control unit housing (14) to the hydraulic block (18), a device (22) for coarse pre-centering and a device (24) for final alignment of the two assemblies (14, 18) to each other, wherein the device (22) for coarse pre-centering comprises at least two pins (26.1, 26.2) supporting themselves on the control unit housing (14), which interact with two bores (28.1, 28.2) provided in the hydraulic block (18), wherein the pins (26.1, 26.2) of the pre-centering device (22) are removable after the final alignment of the two assemblies (14, 18) to each other.

Description

State of the art

[0001] The invention relates to a hydraulic power unit.

[0002] In the manufacture of conventional hydraulic power units, such as those used in an anti-lock braking system (ABS), traction control system (ASR), or electronic stability program (ESP) in a vehicle, the control unit housing is typically bolted to the hydraulic block. The control unit housing is pre-tensioned and secured to the hydraulic block using bolts that engage with corresponding threaded holes in the control unit housing via bushings. The orientation and alignment of the two assemblies relative to each other are determined by the electrical and hydraulic valve components during assembly, although consistent assembly quality is not guaranteed.The control unit housing is screwed to the hydraulic block either without or with the electrical and hydraulic valve components, preferably from the inside or from the outside using a central screw.

[0003] In the patent application WO 2008 / 104412 A1, a hydraulic power unit is described comprising a control unit housing carrying electrical valve components, a hydraulic block carrying hydraulic valve components, and a device for connecting the control unit housing to the hydraulic block. The control unit housing is connected to the hydraulic block by means of screws, with threads provided in the hydraulic block or in the control unit housing for the screws.

[0004] From DE 198 01 234 C2, a valve unit is known which consists of several electrically actuated valves that can be connected in series via opposing connection surfaces to form a package. These valves have at least one pressure medium channel section arranged substantially perpendicular to the connection surface for supplying pressure medium to at least one working port located on an end face of each valve. Corresponding pressure medium channel sections of adjacent valves are connected by series to form a pressure medium channel common to all valves. Each of these channels is pressure-tightly sealed by a closing plate located at the end of the first and last valves of the valve unit. At least one closing plate has corresponding pressure medium connections for supplying pressure medium to each pressure medium channel.The opposing contact surfaces of the disc-shaped valves feature electrical contacts that can be pressed together, allowing for electrical connection between the valves when the valve unit is assembled. A clamping device connecting both end plates and at least partially enclosing the valves presses the electrical contacts together over the valves.

[0005] From EP 0 627 349 A1, a valve block assembly consisting of a valve block and a valve block cover is known. To facilitate assembly and protect the electrical contact pins from bending or damage, the assembly is equipped with an intermediate plate that has guide openings. When the valve block and valve block cover are disassembled, this intermediate plate protectively holds the contact pins. The intermediate plate is held in place by compression springs, which are compressed when the valve block and valve block cover are brought together for assembly. The contact pins then emerge from the protective intermediate plate and engage in the designated contact sockets. This ensures secure and reliable electrical connections within the valve block assembly.

[0006] From DE 195 44 222 A1, a device for connecting a fluid line to a hydraulic block is known. For space-saving installation of the fluid line, an elbow fitting with a one-piece, right-angled pipe stub is proposed, at the end of which a flared end is formed after a union nut has been fitted. The device can be screwed into a bore in the hydraulic block using the union nut. The union nut engages the flared end, which simultaneously provides a seal to the hydraulic block.

[0007] From WO 2008 / 147549 A1, a distributor for directing and controlling fluids in a complex flow circuit of a fluid handling device is known. The distributor comprises a primary distributor block that can be mounted in the device, a secondary distributor block that can be mounted on the primary distributor block, at least one quick-connect fitting for quickly and releasably attaching the secondary distributor block to the primary distributor block, a plurality of flow paths in the primary and secondary distributor blocks, a plurality of flow control devices for controlling the fluid flow in the fluid flow paths of the distributor and the complex flow circuit of the device, and a plurality of distributor connections with connections for external pipes for conveying fluid to and from the fluid flow paths in the distributor.In this design, the majority of the manifold connections with connections for external pipes are insulated and integrated into the primary manifold block, and the multitude of flow control devices are integrated into the secondary manifold block to facilitate the assembly of the manifold in the device during manufacturing and the disassembly and removal of the secondary manifold block during operation without disconnecting external pipes and flow control devices from the manifold.

[0008] From DE 103 22 452 A1, a pressure sensor module for electro-hydraulic brake systems is known, comprising several pressure sensors arranged in a sensor housing, several hydraulic connections on the sensor housing which can be connected to a hydraulic unit by means of a friction-fit element, and a sealing plate between a flange surface of the sensor housing and a connection surface of the hydraulic unit. The sealing plate aligns the sensor housing with the hydraulic unit by means of a positive-locking element.

[0009] The invention is based on the objective of providing a hydraulic power unit that can be assembled easily and quickly. Disclosure of the invention

[0010] This problem is solved by a hydraulic power unit with the features of independent claim 1 and by a hydraulic power unit with the features of independent claim 2.

[0011] In contrast, the hydraulic power unit according to the invention with the features of independent claim 1 and the hydraulic power unit according to the invention with the features of independent claim 2 each have the advantage that a device for coarse pre-centering and a device for final alignment of the two assemblies relative to each other are provided. Advantageously, the device for coarse pre-centering enables a first defined positioning of the control unit housing relative to the hydraulic block in a simple manner and with simple means before the two assemblies are made contact. In the subsequent assembly process, this allows the control unit housing to be brought together with the hydraulic block particularly precisely via the device for final alignment, and the two assemblies can be mounted in a defined manner until they reach their stops.Both the device for rough pre-centering and the device for final alignment enable the improvement of the hydraulic power unit assembly with structurally simple means, thereby increasing production volumes and / or improving the quality of the hydraulic power unit. Such a simplified design of the devices ensures a defined orientation and alignment of the two assemblies relative to each other throughout the entire assembly process and reproducible quality of the assembled hydraulic power unit. This has the advantage that the device according to the invention for rough pre-centering and the device for final alignment enable rapid assembly, which in particular reduces the manufacturing and assembly costs of the hydraulic power unit.Furthermore, due to the improved guidance of the control unit housing to the hydraulic block during assembly, the tight tolerances known from the prior art no longer need to be maintained, thus reducing the manufacturing costs of both assemblies. This also reduces the risk of assembly errors, which in turn further lowers material costs and consequently assembly costs.

[0012] The measures and further developments listed in the dependent claims enable advantageous improvements to the hydraulic unit specified in independent claim 1 and the hydraulic unit specified in independent claim 2.

[0013] A particular advantage is that the device for coarse pre-centering comprises at least two pins that bear against the control unit housing and interact with two bores provided in the hydraulic block. Advantageously, these pins enable initial pre-centering or positioning of the control unit housing relative to the hydraulic block at the beginning of the assembly process, thus ensuring quick and error-free assembly of the hydraulic unit. As mass-produced parts, the pins are particularly cost-effective and easy to manufacture. They are especially well-suited as devices for coarse pre-centering because their simple cylindrical geometry is user-friendly and allows for easy assembly and disassembly. A further advantage is offered by the corresponding installation space for the two pins in the hydraulic block, which also has a cylindrical geometry and is therefore quick and cost-effective to manufacture.

[0014] The pins of the pre-centering device are removable and are removed after the final alignment of the two assemblies relative to each other. Advantageously, the pin is removed after its assigned function has been fulfilled, thus avoiding an unnecessary increase in material mass and enabling the weight-optimized manufacturing of the hydraulic unit according to the invention. Furthermore, this allows the pins to be reused multiple times, thereby further reducing material costs.

[0015] The device for the final alignment of the two assemblies relative to each other comprises at least one dome located on the control unit housing, which can be inserted into a first bore in the hydraulic block for alignment purposes, and a pin provided on the control unit housing, which can be inserted into a second bore in the hydraulic block for alignment purposes. Advantageously, the dome and the pin located on the control unit housing enable quick and easy assembly of the hydraulic unit in a simple design. This allows for optimal alignment of the control unit housing to the hydraulic block in a defined final position, making assembly simple and cost-effective. As a result, a high level of mechanical reliability of the connected assemblies is advantageously ensured right from the start of the assembly process.

[0016] The pin of the control unit housing has knurling on at least part of its outer surface to create a press fit between the two assemblies when the pin is inserted into the second bore of the hydraulic block. This has the advantage that the control unit housing and the hydraulic block can be firmly connected to each other with a short fastener, providing a secure and robust connection. The connection is achieved solely by minimal axial movement into the assembled state. Due to the short length of the pins, the corresponding bores in the hydraulic block that accommodate the pins are advantageously simple and cost-effective to manufacture.

[0017] A preferred embodiment of the hydraulic unit according to the invention provides that the connection between the control unit housing and the hydraulic block is designed as a riveted connection. This has the advantage that a robust connection can be created in a plane of separation between the control unit housing and the hydraulic block using a cost-effective fastening element. This connection, in contrast to conventional connection methods, can be designed to be particularly space-saving and cost-effective. A particular advantage is that the complex design and material costs known in the prior art can be reduced. The originally complex design using screws can be replaced by a cost-effective riveted connection, thereby reducing the number and weight of the fastening components in the control unit housing and eliminating the need for bores in the hydraulic block.This advantageously simplifies the mounting of the control unit housing to the hydraulic block.

[0018] Advantageously, the rivets of the riveted joint can be made of metallic and / or non-metallic material. A high preload can be advantageously achieved in the parting line between the control unit housing and the hydraulic block, whereby, for example, no relaxation phenomena of the rivet occur when using a metallic rivet.

[0019] In a further advantageous embodiment of the hydraulic unit according to the invention, the riveted connection can be designed such that a positive fit exists between at least one rivet of the riveted connection and the control unit housing before riveting. This allows for the particularly advantageous pre-assembly of a component, which greatly simplifies the final assembly of the control unit housing with the hydraulic block. Consequently, assembly costs can be significantly reduced. Furthermore, a rivet positively fitted to the control unit housing is particularly secure against loss, enabling the riveting process to proceed smoothly or even be automated.

[0020] In a further advantageous embodiment of the hydraulic unit according to the invention, the at least one rivet fixed in the control unit housing can be connected to the hydraulic block by gluing and / or welding. A significant advantage is that additional surface treatment of the hydraulic block, such as drilling, can be omitted, since the fastening element, designed as a rivet, can be placed flat on the hydraulic block and does not need to align with a hole in the hydraulic block. Furthermore, the control unit housing and the hydraulic block do not need to adhere to tolerances or be manufactured to precise dimensions in the connection area to ensure a permanently trouble-free connection. This has the advantage that the complex design and machining effort of the connection device according to the invention can be reduced.

[0021] The hydraulic unit can, for example, be used as part of a hydraulic system in a motor vehicle.

[0022] An embodiment of the invention is shown in the drawings and is explained in more detail in the following description. In the drawings, identical reference numerals denote components or elements that perform the same or analogous functions. Brief description of the drawings Fig. Figure 1 shows an exploded view of a hydraulic unit according to the invention, comprising a control unit housing, a hydraulic block connectable to the control unit housing, a device for coarse pre-centering of the two assemblies to each other, and a device for final alignment of the two assemblies to each other. Fig. Figure 2 shows a schematic sectional view of the hydraulic unit. Fig. 1 before mounting the control unit housing to the hydraulic block. Fig. Figure 3 shows a schematic sectional view of the hydraulic unit. Fig. 1 after mounting the control unit housing to the hydraulic block. Fig. Figure 4 shows another schematic sectional view of the assembled hydraulic unit. Fig. 3. Fig. 5 shows a detailed representation of the connection device. Fig. 4 before attaching the control unit housing to the hydraulic block. Fig. Figure 6 shows a further detailed view of the connection device. Fig. 4 after attaching the control unit housing to the hydraulic block. Embodiments of the invention

[0023] As from Fig. As can be seen from Figures 1 to 4, a hydraulic power unit 10 comprises a control unit housing 14 carrying electrical valve components 12 and a hydraulic block 18 carrying hydraulic valve components 16. In the illustrated embodiment, the hydraulic power unit 10 is a component of a motor vehicle's hydraulic system, such as an anti-lock braking system (ABS), an traction control system (ASR), or an electronic stability program (ESP). The control unit housing 14 is preferably designed as a simple plastic component, and the hydraulic block 18 is preferably made of aluminum.

[0024] The hydraulic block 18 has various bores and channels in which, in particular, the hydraulic valve components 16 of solenoid valves 66 are at least partially inserted and preferably crimped. Electrical valve components 12 of the respective solenoid valve 66, in the form of coils 12.1, are axially pushed onto these hydraulic valve components 16.

[0025] A cover 42, which has a printed circuit board 40, can be attached to the rear of the control unit housing 14. The cover 42 can be attached to the control unit housing 14, for example, via a contact surface located on a frame 14.1 surrounding the rear of the control unit housing 14, preferably by means of a weld. The electrical valve components 12 are electrically connected to the printed circuit board 40.

[0026] The hydraulic unit 10 has a device 20 for connecting the control unit housing 14 to the hydraulic block 18, wherein a separating plane XY extends between the control unit housing 14 and the hydraulic block 18. The electrical valve components 12 and the hydraulic valve components 16 extend substantially transversely to this separating plane XY and along a longitudinal axis 44, respectively.

[0027] A seal 46 is arranged in the parting plane XY between the two assemblies 14, 18. The sealing material 58 of the seal 46 is applied in its uncured state to either the control unit housing 14 or the valve side of the hydraulic block 18 before the two assemblies 14, 18 are joined.

[0028] For stiffening, the control unit housing 14 has a bracing device 48, which in the present embodiment consists of ribs 50. The ribs 50 are arranged such that a receiving area 52 for a pressure sensor 54 is formed.

[0029] In order to enable simple and error-free assembly of the hydraulic unit 10 or the control unit housing 14 to the hydraulic block 18, the hydraulic unit 10 according to the invention comprises a device 22 for coarse pre-centering and a device 24 for final alignment of the two assemblies 14, 18 to each other.

[0030] The device 22 for coarse pre-centering comprises at least two pins 26.1 and 26.2 that bear against the control unit housing 14 and interact with two bores 28.1 and 28.2 provided in the hydraulic block 18. During the assembly of the two components 14 and 18, or when the control unit housing 14 is fixed to the hydraulic block 18, the pins 26.1 and 26.2 advance beyond the control unit housing 14. The pre-centering of the control unit housing 14 is achieved via these two advancing pins 26.1 and 26.2, which, through a reference feature in the control unit housing 14, determine the position of the housing 14 on the hydraulic block 18. The pins 26.1 and 26.2 of the pre-centering device 22 can be removed after the final alignment of the two components 14 and 18 with respect to each other.

[0031] The device 24 for the final alignment of the two assemblies 16, 18 relative to each other comprises at least one dome 30 arranged on the control unit housing 14, which can be inserted into a first bore 32 provided in the hydraulic block 18 for alignment purposes, and a pin 34 arranged on the control unit housing 14, which can be inserted into a second bore 36 provided in the hydraulic block 18 for alignment purposes. The dome 30 and the pin 34 are arranged at a defined distance from each other. Preferably, the first bore 32 is designed as a through bore and the second bore 34 as a blind bore. In the present embodiment, the dome 30 and the pin 34 are integrally formed on the control unit housing 14.

[0032] In order to create a press fit between the two assemblies 16, 18 when inserting pin 34 into the second bore 36 of the hydraulic block 18, the pin 34 of the control unit housing 14 has at least partial knurling on its outer surface 34.1 in the illustrated embodiment.

[0033] The dome 30 of the control unit housing 14 has a rib 30.2 on its outer surface 30.1, which, when the dome 30 is inserted into the first bore 32 of the hydraulic block 18, enables a final angular alignment of the axes of symmetry 56 of the control unit housing 14 and the hydraulic block 18. In the present embodiment, the rib 30.2 comprises a rib extending in the direction of the longitudinal axis 44 of the control unit housing 14. Preferably, the dome 30 is designed as a sleeve in which an electrical contact element 38 can be received. The position of the pin 34 and / or the position of the dome 30 is designed such that the circuit board 40 on the control unit housing 14 is correctly positioned relative to the functional elements such as coils 12.1 and pressure sensor 54 of the hydraulic block 18, as well as to the sealing surface or seal 46 of the hydraulic block 18.

[0034] As already explained, the hydraulic unit 10 has a device 20 for connecting the control unit housing 14 to the hydraulic block 18. In the present embodiment, the connecting device 20 is designed as a rivet connection, the rivet connection 20 preferably comprising several rivets 20.1. To connect the control unit housing 14 to the hydraulic block 18, several rivets 20.1 are attached to the control unit housing 14, each of which extends through a through-opening 60 in the control unit housing 14 and is oriented substantially transversely to the parting plane XY, which extends between the control unit housing 14 and the hydraulic block 18. This means that the rivets 20.1 are inserted into the control unit housing 14 with their heads 20.1a facing the circuit board 40. 8 The rivet connection 20 is designed as follows, or the rivets 20.The rivets 20.1 are inserted into the control unit housing 14 in such a way that, prior to riveting, a positive fit exists between at least one rivet 20.1 of the riveted connection 20 and the control unit housing 14. The at least one rivet 20.1 has a collar in its base 20.1b, which creates the positive fit with the control unit housing 14 when the at least one rivet 20.1 is inserted into the through-opening 60 of the control unit housing 14. This means that the rivets 20.1 have a positive fit with the through-openings 60 in the control unit housing 14, with the positive fit being created during pre-assembly of the control unit housing 14.

[0035] The rivets 20.1 of the riveted joint are made of metallic and / or non-metallic material. The rivets 20.1 are made of a material that allows for an adhesive bond and / or a welded connection to the hydraulic block 18. Preferably, the rivets 20.1 are designed as rivet bolts.

[0036] The at least one rivet 20.1 fixed in the control unit housing 14 is preferably connected to the hydraulic block 18 by gluing and / or welding. This creates a permanent connection between the assemblies 14 and 18. For welding, resistance welding or torsional ultrasonic welding is particularly suitable for attaching the control unit housing 14, preferably made of plastic, to the hydraulic block 18, preferably made of aluminum. When using torsional welding, a recess 64 is provided in the control unit housing 14 for each rivet 20.1, which accommodates the material displacement of the rivet 20.1 caused by the torsional welding process. Sonotrodes 62 are used as tools for torsional ultrasonic welding. Fig.6 are required, which are set into resonant vibrations by the introduction of high-frequency mechanical vibrations, the so-called ultrasound. The sonotrodes 62 establish the connection from an ultrasound generator (not shown here) to at least one rivet 20.1 and perform a so-called impedance matching, i.e., the sonotrodes 62 adapt the ultrasound vibration to the machining task.

[0037] To manufacture the hydraulic unit 10, the control unit housing 14 is preferably first molded as a simple plastic component. At least one rivet 20.1 with head 20.1a is inserted into the control unit housing 14, oriented towards the circuit board 40. The at least one rivet 20.1 preferably has a positive fit to the through-hole 60 in the control unit housing 14, which was created during pre-assembly of the control unit housing 14. The at least one rivet 20.1 is made of a material that allows for a welding and / or adhesive bond to the hydraulic block 18. In the present embodiment, several rivets 20.1 are provided. The dome 30 on the control unit housing 14 is designed with ribs 30.2 extending in the direction of the longitudinal axis 44 and simultaneously serves internally as a guide for the electrical contact element 38.Pin 34, located on the control unit housing 14, is positioned at a predetermined distance from the dome 30 and can be either round or knurled. Sealing material 58 is applied in an uncured state to the control unit housing 14 or to the valve side of the hydraulic block 18. The control unit housing 14 is pre-centered by the two leading pins 26.1 and 26.2, which define its position via a reference feature in the control unit housing 14. The control unit housing 14 is then joined to the hydraulic block 18 by aligning pin 34 and dome 30 of the control unit housing 14 with their respective bores 32 and 36 of the hydraulic block 18. The control unit housing 14 is then pressed onto the hydraulic block 18 until it reaches its stop. The knurling of pin 34 of the control unit housing 14 creates a press fit with the hydraulic block 18.The final angular alignment of the symmetry axes 56 of the control unit housing 14 and the hydraulic block 18 is achieved via the ribs 30.2 of the dome 30. The two leading pins 26.1 and 26.2, which defined the pre-centering of the control unit housing 14 on the hydraulic block 18, are retracted and removed. The fastening elements, designed as rivets 20.1, are placed flat on the hydraulic block 18 and do not need to engage a bore in the hydraulic block 18. In a further step, the rivets 20.1 are preferably torsionally welded, with a recess 64, preferably designed as a countersink, being provided in the control unit housing 14 for each rivet 20.1, which accommodates the material displacement of the rivet 20.1 caused by the torsional welding.

Claims

[1] Hydraulic unit (10) with a control unit housing (14) carrying electrical valve components (12), a hydraulic block (18) carrying hydraulic valve components (16), a device (20) for connecting the control unit housing (14) to the hydraulic block (18), a device (22) for coarse pre-centering and a device (24) for final alignment of the two assemblies (14, 18) to each other, wherein the device (22) for coarse pre-centering comprises at least two pins (26.1, 26.2) supporting the control unit housing (14) which interact with two bores (28.1, 28.2) provided in the hydraulic block (18), wherein the pins (26.1, 26.2) of the pre-centering device (22) are removable after the final alignment of the two assemblies (14, 18) to each other. [2] Hydraulic unit (10) comprising a control unit housing (14) carrying electrical valve components (12), a hydraulic block (18) carrying hydraulic valve components (16), a device (20) for connecting the control unit housing (14) to the hydraulic block (18), a device (22) for coarse pre-centering, and a device (24) for final alignment of the two assemblies (14, 18) to each other, wherein the device (24) for final alignment of the two assemblies (16, 18) to each other comprises at least one dome (30) arranged on the control unit housing (14), which can be inserted into a first bore (32) provided in the hydraulic block (18) for alignment, and a pin (34) provided on the control unit housing (14), which can be inserted into a second bore (36) provided in the hydraulic block (18) for alignment, wherein the pin (34) of the control unit housing (14) is located on its outer surface (34.1) at least partially knurling (34.2) has a design to create a press fit between the two assemblies (16, 18) when the pin (34) is inserted into the second bore (36) of the hydraulic block (18). [3] Hydraulic unit (10) according to claim 2, characterized by , that the device (22) for coarse pre-centering comprises at least two pins (26.1, 26.2) which are supported on the control unit housing (14) and which interact with two bores (28.1, 28.2) provided in the hydraulic block (18). [4] Hydraulic unit (10) according to claim 3, characterized by , that the pins (26.1, 26.2) of the pre-centering device (22) can be removed after the final alignment of the two assemblies (14, 18) to each other. [5] Hydraulic unit (10) according to claim 1, characterized by, that the device (24) for the final alignment of the two assemblies (16, 18) to each other has at least one dome (30) arranged on the control unit housing (14), which can be inserted into a first bore (32) provided in the hydraulic block (18) for alignment, and a pin (34) provided on the control unit housing (14), which can be inserted into a second bore (36) provided in the hydraulic block (18) for alignment. [6] Hydraulic unit (10) according to claim 5, characterized by , that the pin (34) of the control unit housing (14) has at least partial knurling (34.2) on its outer surface (34.1) to create a press fit between the two assemblies (16, 18) when the pin (34) is inserted into the second bore (36) of the hydraulic block (18). [7] Hydraulic unit (10) according to any one of claims 1 to 6, characterized by, that the connecting device (20) for connecting the control unit housing (14) to the hydraulic block (18) is designed as a rivet connection. [8] Hydraulic unit (10) according to claim 7, characterized by , that the rivets (20.1) of the riveted joint (20) are metallic and / or non-metallic. [9] Hydraulic unit (10) according to claim 7 or 8, characterized by , that the rivet connection (20) is designed such that a positive fit exists between at least one rivet (20.1) of the rivet connection (20) and the control unit housing (14) before riveting. [10] Hydraulic unit (10) according to one of claims 7 to 9, characterized by , that at least one rivet (20.1) fixed in the control unit housing (14) can be connected to the hydraulic block (18) by gluing and / or welding. [11] Hydraulic unit (10) according to any one of claims 1 to 10, characterized by, that the hydraulic unit (10) is a component of a hydraulic system of a motor vehicle.

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