Hydraulic block for a hydraulic assembly of a power-assisted vehicle brake device

Abstract

In order to prevent the assistance piston (7) of an assistance brake pressure generator (3) of a hydraulic assistance-vehicle brake system from being twisted, axial parallel twist-stop grooves (23) are provided on the circumference of an assistance cylinder bore (6) in a hydraulic block (1) of a hydraulic assembly of the assistance-vehicle brake system, into which twist-stop grooves a lug (21) of the assistance piston (7) projects.

Description

TECHNICAL FIELD

[0001] The invention relates to a hydraulic block for a hydraulic assembly of a hydraulic power- assisted vehicle brake device according to the invention and to a method for producing said hydraulic block. Such a hydraulic block serves to mechanically fasten and hydraulically connect hydraulic structural elements for generating a brake pressure with power assistance and for regulating or controlling a brake pressure and / or for carrying out a slip regulation. In the case of an equipment with said hydraulic structural elements, the hydraulic block forms a hydraulic assembly. BACKGROUND

[0002] The patent application DE 10 2017 214 593 A1 discloses a hydraulic assembly for a hydraulic power- assisted vehicle brake device with a square hydraulic block, which has a power cylinder bore in which a power piston for generating a hydraulic brake pressure with power assistance is received in an axially movable manner. At the bore opening of the power cylinder bore, an electric motor is fastened on the hydraulic block, with which the piston can be moved in the power cylinder bore of the hydraulic block by means of a worm gear drive. The worm gear drive is arranged between the electric motor and the power piston. By means of the movement of the power piston in the power cylinder bore, a brake pressure can be generated and / or brake fluid can be delivered. With an electromagnetic valve arranged at or in the hydraulic block, a brake pressure can be regulated and / or a wheel brake pressure in a hydraulic wheel brake connected to the hydraulic block by means of a brake line can be regulated for carrying out a slip regulation.

[0003] For the torsion-proofing of the power piston, the known hydraulic block has three cylindrical pins, which are arranged on the inner circumference of the power cylinder bore in a circumferential range in an axially parallel manner to the power cylinder bore, so that they project inwards by approximately half of their diameter. On the end facing the electric motor, a ring surrounding the power piston is fitted onto the power piston. The ring has three inwardly projecting lugs, which project into complementary recesses of the power piston and thereby hold the ring torsion-proof on the power piston, and it has three semicircular recesses on its outer circumference, into which the cylindrical pins are inserted, so that the power piston is held in an axially movable and torsion-proof state by the cylindrical pins and the ring. SUMMARY

[0004] The hydraulic block according to the invention is configured in a hydraulic assembly for a hydraulically assisted vehicle braking system, which in particular has a slip adjustment mechanism. The core component of the hydraulically assisted vehicle braking system with a slip adjustment mechanism is the hydraulic assembly with the hydraulic block, to which the hydraulic wheel brakes of the vehicle braking system are connected via brake lines. The slip adjustment mechanism is particularly an anti-lock braking system, actuation slip, and / or driving dynamics adjustment mechanism / electronic stability program, commonly abbreviated as ABS, ASR, and / or FDR / ESP. The latter is also colloquially referred to as an "anti-slip adjustment mechanism." The slip adjustment mechanism is well-known and will not be explained in detail here. The hydraulic assembly is used to generate braking pressure with assistance and to adjust the braking pressure.

[0005] The hydraulic block is used to mechanically fix and hydraulically connect the hydraulic structural elements of a vehicle braking device or its slip adjustment mechanism. Such hydraulic structural elements include, in particular, solenoid valves, check valves, hydraulic accumulators, damping chambers, pressure sensors, and power-assisted braking pressure generators, wherein the power-assisted braking pressure generator has a piston-cylinder unit housed in the power-assisted cylinder bore of the hydraulic block. The power-assisted piston of the piston-cylinder unit of the power-assisted braking pressure generator is often also referred to as a plunger piston, and the power-assisted cylinder bore is referred to as a plunger receiver, plunger bore, plunger cylinder, or similar names. To generate pressure with assistance, the power-assisted piston of the power-assisted braking pressure generator is moved electromechanically within the cylinder or in the power-assisted cylinder bore by means of an electric motor mounted outside the hydraulic block via a helical gear transmission mechanism, wherein a mechanical reducer, particularly a planetary gear transmission mechanism, can be arranged between the electric motor and the helical gear transmission mechanism. The power-assisted cylinder bore in the hydraulic block can form the cylinder of the power-assisted braking pressure generator, or a cylinder, cylinder liner, etc., can be arranged at or within the power-assisted cylinder bore. The booster cylinder bore can also be understood as a receiving part for the piston or piston-cylinder unit of the booster braking pressure generator.

[0006] The hydraulic structural element is fixed in a receiving portion within the hydraulic block, which is typically constructed as a cylindrical through-hole or blind hole with stepped diameters. "Connection" means that the receiving portion, or the hydraulic structural element fixed therein, is connected via piping within the hydraulic block according to the hydraulic wiring diagram of the vehicle's braking system or its slip adjustment mechanism. This piping is typically drilled into the hydraulic block.

[0007] In the case of a hydraulic structural element equipped with the vehicle braking device or its slip adjustment mechanism, the hydraulic block forms a hydraulic assembly, wherein “equipped” means that the hydraulic structural element is fixed in a receiving portion provided for it in the hydraulic block.

[0008] The hydraulic block according to the application is in particular square and preferably drilled in a Cartesian manner and consists in particular of metal. "Drilled in a Cartesian manner" means that the receptacles for the structural elements for the hydraulic and the lines connecting them are arranged in the hydraulic block parallel to and perpendicular to one another and parallel to and perpendicular to the surface and edges of the hydraulic block. Individual inclined receptacles and / or lines are possible.

[0009] The hydraulic block according to the application has a torsion stop groove for the power piston, which is arranged on the circumference of the power cylinder bore. The torsion stop groove runs in the longitudinal direction of the power cylinder bore, that is to say axially parallel or possibly at an angle, such as wavelike or helical, to the axial plane of the power cylinder bore. The torsion stop groove is open towards the power cylinder bore, so that a torsion stop element of the power piston, which supports the power piston in a torsion-proof and axially movable manner in the torsion stop groove, can be fitted into the torsion stop groove. The torsion stop element of the power piston can be, for example, a lug which protrudes outward from the power piston and into the torsion stop groove.

[0010] The hydraulic block according to the application can have a plurality of torsion stop grooves, which are arranged uniformly or non-uniformly distributed over the circumference of the power cylinder bore.

[0011] The application achieves the torsion stop of the power piston in a simple manner and without additional parts with the one or more torsion stop grooves.

[0012] Further subjects of the application are improvements and advantageous design options of the application as specified in the claims.

[0013] A preferred design option of the application provides a centring groove which surrounds the bore opening of the power cylinder bore concentrically, the inner wall and / or the outer wall of which form a centring surface for a rotary bearing of a worm gear drive for moving the power piston in the power cylinder bore. An improvement provides a rotary bearing carrier which is held on the inner wall of the centring groove in a press fit and is thereby centred relative to the power cylinder bore.

[0014] The circumferential surface of the power cylinder bore, which axially movably guides the power piston, and the centring groove or in any case the groove wall which forms the centring surface are preferably manufactured or in any case finished with the tooling at the same time, thereby ensuring the concentricity of the centring surface relative to the circumferential surface of the power cylinder bore.

[0015] All features disclosed in the specification and drawings can be implemented individually or in virtually any combination in embodiments of the invention. Embodiments of the invention, not having all the features of the claims or embodiments, but having only one or more of those features, are possible in principle. Attached Figure Description

[0016] The invention will now be explained in detail with the aid of an embodiment shown in the accompanying drawings. Wherein:

[0017] Figure 1 A perspective view shows the hydraulic block according to the invention;

[0018] Figure 2 It shows having Figure 1 A cross-section of the hydraulic assembly of the hydraulic block in the axial plane of the booster cylinder bore;

[0019] Figure 3 It shows Figure 1 The hydraulic block, relative to the booster cylinder bore Figure 2 An axial section in an axial plane that has been twisted by 90°;

[0020] Figure 4 The finishing of the booster cylinder bore and the manufacture of the centering groove surrounding the booster cylinder bore according to the invention are shown; and

[0021] Figure 5 The schematic diagram illustrates the drilling of the pilot hole and the milling of the torsion stop groove according to the invention. Detailed Implementation

[0022] exist Figure 1 The hydraulic block 1 shown in the figure is configured for hydraulic operation and has a slip adjustment mechanism in the hydraulic assembly 2 of the power-assisted vehicle braking device. Figure 2 A cross-section of the hydraulic assembly 2 in the axial plane of the power steering cylinder bore 6 is shown. Slip adjustment mechanisms, particularly anti-lock braking, actuation slip, and / or ride power adjustment mechanisms / electronic stability programs, are commonly abbreviated as ABS, ASR, and / or FDR / ESP. Hydraulic power-assisted vehicle braking systems with slip adjustment mechanisms and their hydraulic wiring diagrams are known and not explained here.

[0023] In this embodiment, the hydraulic block 1 is a narrow, square metal block whose large, opposing sides are almost square. "Narrow" means that the distance between the two large sides is no greater than half the length or width of the large side. In this embodiment, the distance between the two large sides is approximately one-third to one-quarter of the length or width of the large side. Other side proportions are possible. The described shape of the hydraulic block 1 is not mandatory for this invention.

[0024] The hydraulic block 1 serves to mechanically fix and hydraulically connect hydraulic structural elements with a force-assisted brake pressure generation mechanism during force- assisted braking and / or during slip regulation and for brake pressure regulation. Such hydraulic structural elements are, inter alia, solenoid valves, non-return valves, hydraulic accumulators, hydraulic pumps and force- assisted brake pressure generators 3. The hydraulic structural elements are fixed in receptacles in the hydraulic block 1. The receptacles are cylindrical depressions, blind holes and / or also through-holes, which can have diameter steps and into which the hydraulic structural elements are inserted and fixed airtight, for example by a surrounding press-in portion (Verstemmung). The hydraulic structural elements can be sunk into the receptacles or protrude from the hydraulic block 1. In the case of equipping with hydraulic structural elements, the hydraulic block 1 forms a hydraulic assembly 2 for force- assisted brake pressure generation and brake pressure regulation of the force-assisted vehicle brake system.

[0025] Hydraulic connection means that the receptacles for the hydraulic structural elements are connected to one another by means of lines which pass through the hydraulic block 1 according to the hydraulic circuit diagram of the force-assisted vehicle brake system or of its slip regulation mechanism. The receptacles and lines form a so-called "verbohrung" of the hydraulic block 1, wherein the receptacles and lines can also be produced in a manner different from drilling.

[0026] The hydraulic block 1 according to the application has a force cylinder bore 6 which passes through the hydraulic block 1 perpendicular to two opposite large sides of the hydraulic block 1. The force cylinder bore 6 can be drilled or produced in a manner different from drilling. The force cylinder bore 6 forms a cylinder of a cylinder-piston unit of a force- assisted brake pressure generator 3 and serves to movably receive a force piston 7 of the force- assisted brake pressure generator 3, which is often also referred to as a plunger piston. The force piston 7 can be guided in an axially movable manner directly in the force cylinder bore 6 or indirectly in a cylinder sleeve or cylinder which is arranged in the force cylinder bore 6.

[0027] The electric motor 4 for driving, i.e. for moving the force piston 7 in the force cylinder bore 6, is arranged coaxially to the force cylinder bore 6 outside one of the two large sides of the hydraulic block 1, which is referred to here as the motor side 8 of the hydraulic block 1. The electric motor 4 moves the force piston 7 by means of a planetary gear transmission as a reduction gear 9 and a helical gear transmission 10 which is produced as a ball screw transmission in the present embodiment. The electric motor 4, the reduction gear 9, the helical gear transmission 10, the force piston 7 and the force cylinder bore 6 form a force- assisted brake pressure generator 3 for generating a hydraulic brake pressure for force- assisted braking.

[0028] The assist piston 7 is a cylinder-shaped hollow piston with a closed end facing the closed end of the assist cylinder bore 6. The helical gear transmission mechanism 10 is coaxially arranged in the assist piston 7, which is constructed as a hollow piston, wherein the main shaft 11 is rigidly connected to the piston base 13 at the closed end of the assist piston 7 by means of a tenon joint 12. A tubular main shaft nut 14 extends into the annular gap between the main shaft 11 and the assist piston 7, which is constructed as a hollow piston, and protrudes from the open end of the assist piston and from the opening of the assist cylinder bore 6 on the motor side 8 of the hydraulic block 1. Outside the assist piston 7, the main shaft nut 14 is rotatably supported on the hydraulic block 1 by a ball bearing as a rotary bearing 15.

[0029] The rotary bearing 15 is fixed to the hydraulic block 1 by a short, cylinder-sleeve-shaped bearing support 16 in the axial direction. The bearing support 16 extends into a circular centering groove 17, which is located in the motor side 8 of the hydraulic block 1 and concentrically surrounds the auxiliary cylinder bore 6 at its opening. In this embodiment, the centering groove 17 has a rectangular cross-section. A cylinder-sleeve-shaped centering flange 18 is formed in the axial direction through the centering groove 17, the outer circumferential surface of which forms a centering surface 19 for the bearing support 16 and the rotary bearing 15. The outer circumferential surface of the centering flange 18 forming the centering surface 19 is also the inner wall of the centering groove 17.

[0030] The bearing bracket 16 is pressed against the centering flange 18 until it touches the bottom of the centering groove 17, so that the bearing bracket is held on the centering flange 18 by press fit.

[0031] At the bottom of the groove, the bearing support 16 has an outwardly extending radial flange 20 on which the bearing support is held on the hydraulic block 1 by a surrounding pressing part 43, through which the material of the hydraulic block 1 is plastically formed onto the radial flange 20.

[0032] The centering groove 17 is as follows Figure 4 As simplified and schematically shown, the auxiliary cylinder bore 6 is manufactured simultaneously with the finishing of the circumferential surface using a milling tool 42 (in this embodiment, a crown milling cutter 39) and the auxiliary cylinder bore 6, provided that the auxiliary cylinder bore guides the auxiliary piston 7 in an axially movable manner. Therefore, the centering groove 17 is manufactured simultaneously with the finishing of the circumferential surface of the auxiliary cylinder bore 6 using a tool (in this embodiment, a milling tool 42), thereby ensuring that the centering groove 17 and the centering surface 19 for the rotary bearing 15 are precisely coaxial with the circumferential surface of the auxiliary cylinder bore 6.

[0033] If it is possible Figure 1As can be seen, the booster piston 7 has two radially outwardly projecting lugs 21 on its end facing the orifice of the booster cylinder bore 6, a cap-shaped slide 22 of plastic is fitted onto the lugs. The lugs 21 and the slide 22 are fitted into a torsion stop groove 23 which is arranged axially parallel at opposite circumferential positions of the booster cylinder bore 6 in the hydraulic block 1. Thereby, the booster piston 7 is held torsionally and can be moved axially. The torsion stop groove 23 is open towards the booster cylinder bore 6. The outwardly projecting lugs 21 of the booster piston 7 can generally also be understood as torsion stop elements. In Figure 2 The torsion stop groove 23 is drawn in the present embodiment in such a way that it is offset by 90° around the axis of the booster cylinder bore 6, so that the torsion stop groove can be seen.

[0034] In the present embodiment, the torsion stop groove 23 is open at the orifice of the booster cylinder bore 6 and ends axially approximately at the centre of the booster cylinder bore 6. The torsion stop groove has in the present embodiment groove walls which are parallel to one another and a semicylindrical groove bottom. The shape, arrangement and number of the torsion stop grooves 23 are not compulsory for the invention.

[0035] The planetary gear mechanism forming the reduction gear 9 is arranged in a transmission cover 24 which is fitted onto the bearing carrier 16 of the rotary bearing 25 of the worm gear mechanism 10. In the present embodiment, the transmission cover 24 likewise has the shape of a short cylinder sleeve in axial direction, which has a bottom which in turn has a central hole for the motor shaft 25 of the electric motor 4. The sun wheel 26 of the planetary gear mechanism is arranged rigidly on the motor shaft 25 and the ring gear 27 of the planetary gear mechanism is arranged rigidly in the transmission cover 24. The planet wheels 28 of the planetary gear mechanism are arranged rotatably on cylindrical pins which project axially parallel from the end side of the spindle nut 14 of the worm gear mechanism 10. The spindle nut 14 forms the planet wheel carrier of the planetary gear mechanism.

[0036] The electric motor 4, together with the planetary gear mechanism forming the reduction gear 9, the worm gear mechanism, the booster piston 7 and the booster cylinder bore 6, is fixed coaxially on the motor side 8 of the hydraulic block 1, in the present embodiment the motor housing of the electric motor 4 is screwed together with the hydraulic block 1.

[0037] In order to generate a hydraulically boosted brake pressure, the spindle nut 14 of the worm gear mechanism 10 is driven rotationally by the electric motor 4 via the planetary gear mechanism, whereby the spindle 11 moves the booster piston 7 in the booster cylinder bore 6.

[0038] For regulating the brake pressure, where "regulating" also means controlling, an electromagnetic valve 29 is arranged at or in the valve side 30 of the hydraulic block 1 opposite the motor side 8. The electromagnetic valve 29, which is drawn as a line symbol, is arranged in a blind hole, which is placed in the valve side 30 of the hydraulic block 1. The blind hole can have diameter steps and form a receptacle for the electromagnetic valve 29. The electromagnetic valve 29 is, for example, an inlet valve and an outlet valve of a slip regulation and can also be used for brake pressure regulation during power braking. The brake pressure itself is regulated during power braking by the movement of the power piston 7 in the power cylinder bore 6. The electromagnet 31 of the electromagnetic valve 29, which is also shown as a line symbol in the drawing, is outside the hydraulic block 1 in a valve arch 32, which projects from the valve side 30 of the hydraulic block 1.

[0039] The hydraulic block 1 has a main brake cylinder bore 33, in which a not shown main brake cylinder piston is received in a movable manner. The main brake cylinder piston, which can also be called a rod piston or primary piston, can be moved in the main brake cylinder bore by a muscle force with a not shown foot brake pedal or hand brake lever by means of a pedal lever. For the construction as a dual-circuit main brake cylinder, a second so-called floating piston or secondary piston can be arranged in the main brake cylinder bore 33. The main brake cylinder bore 33 runs through the hydraulic block 1 parallel to the two large sides of the hydraulic block 1 and in the center between the two large sides. The main brake cylinder piston or the main brake cylinder pistons can be guided in an axially movable manner directly in the main brake cylinder bore 33 or indirectly in a cylinder sleeve, which is arranged, for example, in the main brake cylinder bore 33.

[0040] The power cylinder bore 6 is drilled into the hydraulic block 1 or otherwise, in particular cut, manufactured. The so-called pilot bore 44 is drilled into the hydraulic block 1 or otherwise, in particular cut, manufactured in axial parallel to the power cylinder bore 6 on the motor side 8 beforehand, simultaneously or thereafter. The drilling of the pilot bore 44 is in the region of the power cylinder bore 6. Figure 5The left side is indicated by drill bit 34. The pilot hole 44 is drilled at the edge of the transition between the torsion stop groove 23 and the centering groove 17, with the two sides facing each other radially. Preferably, the torsion stop groove 23 and the centering groove 17 are formed after the pilot hole 44. The pilot hole 44 avoids the sharp, cutting edge at the transition between the torsion stop groove 23 and the centering groove 17, which could damage the slide 22 on the lug 21 of the booster piston 7. The pilot hole 44 is located at the edge where a crown cutter 39 or other tool exits from the centering groove 17 and enters the torsion stop groove 23 during the formation of the centering groove 17. At the edge where a pilot hole is not required, the crown cutter 39 or other tool re-enters the centering groove 17 from the torsion stop groove 23; however, pilot holes can still be formed at these edges. The rotation direction of the crown end mill 39 or other tool is determined when manufacturing the centering groove 17: at which two edges the pilot hole 44 should be placed. Preferably, the centering groove 17 and the torsion stop groove 23 are manufactured after the pilot hole 44.

[0041] After manufacturing the booster cylinder bore 6, the surrounding groove 35 for sealing the piston seal 36 (sealing ring) used to seal the booster piston 7 and the through-hole 37 extending in a limited circumferential section along the circumferential direction are milled into the circumferential surface of the booster cylinder bore 6, for example, using a disc milling cutter (not shown), or they are otherwise formed, particularly by cutting. The groove 35 and through-hole 37 for the piston seal 36 can be manufactured before, during, or after manufacturing the pilot bore and the torsion stop groove 23.

[0042] Preferably, after manufacturing the groove 35 and through-hole 37 for the piston seal 36, the circumferential surface of the booster cylinder bore 6 is precision-machined or finished, for example, using a finish milling cutter 38 or a reamer. The axial section of the circumferential surface of the booster cylinder bore 6 is to be precision-machined or finished, guiding the booster piston 7 in an axially movable manner. The same tool, in this embodiment, the finish milling cutter 38 used for precision machining or finishing the circumferential surface of the booster cylinder bore 6, has a crown cutter 39 mentioned above in conjunction with the pilot hole 44, or other mechanisms for specifically cutting the centering groove 17. The tool having the finish milling cutter 38 and the crown cutter 39 is also referred to herein as a milling tool 42. For example, it can be... Figure 4As can be seen, at the same time and with only one tool, in this embodiment with the milling tool 42 with the crown milling cutter 39 and the finish milling cutter 38 together with the centering groove 17, the peripheral surface of the power cylinder bore 6 is produced. In any case, with the tool together with the peripheral surface of the power cylinder bore 6, the centering surface 19 of the rotary bearing 15 of the spindle nut 14 for the helical gear transmission 10 is finished, whereby the centering surface 19 is precisely coaxial with the peripheral surface of the power cylinder bore 6.

[0043] Preferably after the production of the centering groove 17, the torsion stop groove 23 is milled or otherwise cut. Here, the milling tool 40 can be moved alternately axially parallel and radially inwards and outwards as shown with arrows in Figure 5 The milling tool 40 has a bevel milling cutter 41 which, in the last movement of the milling tool 40, mills a bevel radially inwards at the edge at the open end of the torsion stop groove 23 at the transition of the torsion stop groove into the motor side 8 of the hydraulic block 1.

Claims

1. Hydraulic block for a hydraulic assembly of a power-assisted vehicle brake device, wherein the hydraulic block (1) has a power cylinder bore (6), characterized in that The hydraulic block (1) has a torsion stop groove (23) for torsionally fixing a power cylinder piston (7) which extends along the longitudinal direction of the power cylinder bore (6) on the circumference of the power cylinder bore (6) and which opens towards the power cylinder bore (6), wherein the hydraulic block (1) has a centering groove (17) which concentrically surrounds the aperture of the power cylinder bore (6), the inner wall and / or the outer wall of which forms a centering surface (19) for a rotary bearing (15) of a worm gear drive (10) for moving the power cylinder piston (7).

2. The hydraulic block of claim 1, wherein, The bearing support (16) of the rotary bearing (15) bears with a press fit against the inner wall of the centering groove (17).

3. The hydraulic block of claim 1, wherein, The torsion stop groove (23) has a rounded groove bottom.

4. The hydraulic block of claim 1, wherein, The hydraulic block (1) has two torsion stop grooves (23) which are opposite one another.

5. The hydraulic block of claim 1, wherein, The hydraulic block (1) has a main brake cylinder bore (33).

6. Method for manufacturing a hydraulic block according to any one of claims 1 to 5, characterized in that, The circumference of the power cylinder bore (6) and the centering surface (19) are finished at the same time with tools (38, 39, 42).

7. Method for manufacturing a hydraulic block according to any one of claims 1 to 5, characterized in that, At the same time as the end faces of the torsion stop groove (23) are finished in the hydraulic block (1) and with tools (40, 41) on the end of the torsion stop groove (23), a chamfer is produced on the end edge of the torsion stop groove (23) at the aperture of the power cylinder bore (6).

8. Method for manufacturing a hydraulic block according to any one of claims 1 to 5, characterized in that, Before the centering groove (17) and the torsion stop groove (23) are produced, a pilot hole (44) is placed on the edge at the transition from the centering groove (17) to the torsion stop groove (23) in the hydraulic block (1).

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