Pump housing for a motor vehicle hydraulic unit

Abstract

Pump housing (22) for a motor vehicle hydraulic unit in which a reservoir connection (108) is provided for supplying brake fluid from a reservoir (62), wherein two brake circuits (18, 20) are formed with the pump housing (22), characterized in that the reservoir connection (108) is assigned to a first of the two brake circuits (20).

Description

State of the art

[0001] The invention relates to a pump housing for a motor vehicle hydraulic unit. Furthermore, the invention relates to the use of such a pump housing in a vehicle braking system.

[0002] Hydraulic units are used in motor vehicles, such as passenger cars or trucks, to provide regulated brake pressure to their braking systems. In particular, such hydraulic units implement the functions of an anti-lock braking system (ABS), an anti-skid control system (ASR), and / or an electronic stability program (ESP). In the braking system, braking pressure is generated at a master brake cylinder, particularly by a driver of the vehicle via a brake pedal. For this purpose, brake fluid is fed from a reservoir to the master brake cylinder, which then supplies it under pressure to the hydraulic unit and through it to the associated wheel brake cylinders. To meter the brake fluid, the hydraulic units have a pump with several pump pistons or pump elements, a motor, and a plurality of valves.The valves are usually electromagnetically controlled, allowing different brake pressures to be provided to several brake circuits at the wheel brake cylinders. At least one master brake cylinder connection port is provided on the hydraulic unit to hydraulically connect the hydraulic unit to the master brake cylinder.

[0003] The pump housing of such a hydraulic unit is usually essentially cuboid or block-shaped and made of aluminum with flat or stepped side surfaces and is provided with holes for the arrangement of the components and lines.

[0004] From WO 2004 / 048 173 A2 a pump housing for a motor vehicle hydraulic unit is known, in which a reservoir connection is provided for supplying brake fluid from a reservoir.

[0005] It is an object of the invention to provide a motor vehicle hydraulic unit with a pump housing which, compared to known pump housings, has a greater range of functions at similar manufacturing costs. Disclosure of the invention

[0006] This object is achieved with a pump housing for a motor vehicle hydraulic unit, in which a reservoir connection for supplying brake fluid from a reservoir is provided according to claim 1. According to the invention, brake fluid is therefore provided to the pump housing separately, immediately, and directly from the reservoir. With this type of pump housing design, it is particularly possible for brake fluid to be made available to it in a pressureless manner from a reservoir through an associated line. The brake fluid thus provided can be used in the pump housing to provide a "brake-by-wire" function, i.e., braking without direct force feedback between the wheel brake cylinder and the brake pedal, at least on individual wheels.For this purpose, the brake fluid, which is supplied without pressure, is brought to increased pressure in the pump housing by means of the associated pump elements and metered to the wheel brake cylinders via the associated valves. The pump housing forms two brake circuits, and the reservoir connection is assigned to the first of the two brake circuits.

[0007] The pump housing advantageously has a first side surface on which a storage opening is provided and on which the reservoir connection is also located. Selecting the side surface on a block-shaped pump housing that also has a storage opening is advantageous in that a particularly advantageous drilling pattern for the associated line routing can then be created inside the pump housing. In particular, a drilling pattern can be selected that largely corresponds to the drilling pattern of previous pump housings, so that all the knowledge gained from these pump housings regarding specifications, manufacturing, and operation can be reused.

[0008] The pump housing according to the invention forms two brake circuits, and the reservoir connection is assigned to a first of the two brake circuits, in particular a rear-wheel brake circuit. This development is advantageous in that a "brake-by-wire" function can be used particularly advantageously on a rear wheel and in particular on a rear axle.

[0009] The accumulator opening is particularly preferably assigned to the second brake circuit, in particular a front-wheel brake circuit. This type of pump housing can generate a conventional braking function on the front wheel, and in particular on a front axle, with a pass-through between the brake pedal and the wheel brake cylinder, thus ensuring emergency braking functionality even if the brake-by-wire function fails. Alternatively, the accumulator opening can also be assigned to the rear axle, in which case the brake-by-wire function is then implemented by the front-wheel brake circuit.

[0010] The reservoir connection is also advantageously positioned in each spatial area of ​​the pump housing for the first brake circuit in which the accumulator opening for the second brake circuit is positioned. This type of arrangement of a reservoir connection on a pump housing is particularly advantageous because the remaining bores and connections of the respective brake circuits can then be left largely the same as in conventional pump housings. Furthermore, such an arrangement can particularly advantageously achieve a valve position inside the pump housing at which an outlet control valve for the "brake-by-wire" function can be placed, replacing a conventional master brake cylinder switching valve.The outlet control valve is used to establish the connection between the pump housing and the reservoir when the corresponding wheel brake cylinders are not to be actuated by means of the master brake cylinder but by means of the “brake-by-wire” function.

[0011] The pump housing advantageously has a second side surface with at least two inlet valve openings and at least two outlet valve openings, which extends substantially perpendicular to the first side surface on which the reservoir connection is provided. With this design, the connections for certain valves on the pump housing are arranged on a different side surface than the reservoir connection. This design is significantly advantageous with regard to the overall bore pattern in the hydraulic unit and with regard to its engine and wheel brake cylinder connections.

[0012] At least one high-pressure switching valve opening and / or at least one switching valve opening and / or at least one outlet control valve opening and / or at least one isolating valve opening are preferably provided on the second side surface. For an advantageous drilling pattern inside the pump housing according to the invention, a pump element opening for receiving an associated pump element is preferably positioned on a further side surface.

[0013] Furthermore, a pressure sensor connection is preferably provided on the pump housing, which is assigned, in particular, to each of the two brake circuits, to which the reservoir connection is also assigned. The associated pressure sensor can be used to determine the brake pressure in the pump housing for the "brake-by-wire" function.

[0014] With regard to the bore pattern design inside the pump housing, the pressure sensor connection is advantageously positioned on the side surface of the pump housing on which at least two inlet valve openings and at least two outlet valve openings are also provided.

[0015] The invention is further directed to the use of such a pump housing according to the invention in a vehicle brake system according to claim 10, wherein a connecting line to a reservoir of the vehicle brake system is connected to the pump housing's reservoir connection. The associated reservoir for brake fluid is advantageously arranged on the master brake cylinder of the vehicle brake system itself.

[0016] An exemplary embodiment of the inventive solution is explained in more detail below with reference to the attached schematic drawings. It shows: Fig. 1 a hydraulic diagram of a vehicle braking system according to the invention and Fig. 2 a perspective view of a pump housing of the vehicle brake system according to Fig. 1.

[0017] One in Fig. The vehicle brake system 10 shown in Figure 1 comprises a brake pedal 12 with odometer, a brake booster 14 and a master brake cylinder 16 connected thereto. The master brake cylinder 16 is connected to two brake circuits 18 and 20, which are essentially located in a common pump housing 22 (see Fig. 2). In an embodiment of the inventive solution (not shown), no brake booster 14 is provided. Instead, in this embodiment, a brake boosting effect is depicted with pump elements explained in more detail below.

[0018] Brake circuit 18 is assigned to a front axle of the associated vehicle (not shown in detail). In brake circuit 18, a line 24 leads from the master brake cylinder 16 to a high-pressure switching valve 26 and a changeover valve 28. A pressure sensor 30 is also connected to line 24. From the high-pressure switching valve 26, a line 32 leads to the suction side of three pump elements 34 and to a check valve 36. From the changeover valve 28, a line 38 leads to the pressure side of the pump elements 34 and to a first inlet valve 40 and a second inlet valve 42. From the check valve 36, a line 44 leads to a first outlet valve 46 and a second outlet valve 48. An accumulator 50 is also connected to line 44. From the first inlet valve 40, a line 52 leads to a first wheel brake cylinder 54 assigned to the front axle and to the first outlet valve 46.From the second inlet valve 42, a line 56 leads to a second wheel brake cylinder 58, also assigned to the front axle, and to the second outlet valve 48.

[0019] On the left side of the Fig. 1 illustrates brake circuit 20. This brake circuit implements a "brake-by-wire" function on the vehicle's braking system for an assigned rear axle (not shown further). For this purpose, a line 60 leads from a reservoir 62 for brake fluid to an outlet control valve 64. The reservoir 62 is arranged on the master brake cylinder 16 and provides pressureless brake fluid, which can be fed into the master brake cylinder 16 and also into the line 60. From the outlet control valve 64, a line 66 leads to the suction side of three pump elements 68 as well as to a third outlet valve 70 and a fourth outlet valve 72. From the master brake cylinder 16, a line 74 leads to an isolating valve 76. From the isolating valve 76, a line 78 leads to the pressure side of the pump elements 68, to the outlet control valve 64, to a pressure sensor 79, and to a third inlet valve 80 and a fourth inlet valve 82.No accumulator is connected to line 78. A line 84 leads from the third inlet valve 80 to a third wheel brake cylinder 86 assigned to the rear axle and to the third outlet valve 70. A line 88 leads from the fourth inlet valve 82 to a fourth wheel brake cylinder 90, also assigned to the rear axle, and to the fourth outlet valve 72.

[0020] In Fig. Figure 2 shows the pump housing 22, which is essentially formed from a cuboid-shaped aluminum block with an optional step at the top. Openings are formed in the aluminum block by drilling or milling.

[0021] Thus (relative to Fig. 2) on a rear side 92 of the aluminum block, four wheel brake cylinder openings 94 for receiving the connections for the wheel brake cylinders 54, 58, 86 and 90.

[0022] On an underside 96 of the aluminum block (which, in the sense of the claims, represents a second side surface of the aluminum block), four intake valve openings 98 for accommodating the intake valves 40, 42, 80, and 82 are arranged in a first row. Next to these, in a second row, are four exhaust valve openings 100 for accommodating the exhaust valves 46, 48, 70, and 72. Next to these, in a third row, are another four openings 102 for accommodating the high-pressure switching valve 26, the changeover valve 28, the exhaust control valve 64, and the isolation valve 76.

[0023] On a front side 104 of the aluminum block (which, in the sense of the claims, represents a first side surface of the aluminum block), on the right, in the area of ​​the pump housing 22 assigned to the brake circuit 18, there is a reservoir opening 106 for receiving the aforementioned accumulator 50. On the left, in the area of ​​the pump housing 22 assigned to the brake circuit 20, there is a reservoir connection opening at the same position as the reservoir connection 108, relative to the surface of the front side. Line 60, which leads from the reservoir 62 to the outlet control valve 64, is connected to this reservoir connection 108.

[0024] On an upper side 110 of the pump housing 22 according to Fig. 2, finally, a motor connection 112 is provided for an associated drive motor (not shown) for driving the pump elements 34 and 68 to be arranged in pump element openings 114.

Claims

[1] Pump housing (22) for a motor vehicle hydraulic unit in which a reservoir connection (108) is provided for supplying brake fluid from a reservoir (62), wherein two brake circuits (18, 20) are formed with the pump housing (22), characterized by that the reservoir connection (108) is assigned to a first of the two brake circuits (20). [2] Pump housing according to claim 1, wherein the pump housing (22) has a first side surface (104) on which a storage opening (106) is provided, and furthermore the reservoir connection (108) is located on this first side surface (104). [3] Pump housing according to claim 1 or 2, wherein the first of the two brake circuits (20) associated with the reservoir connection (108) corresponds to a rear wheel brake circuit. [4] Pump housing according to one of claims 1 to 3, wherein the storage opening (106) is assigned to the second brake circuit (18), in particular a front wheel brake circuit. [5] Pump housing according to claim 4, wherein the reservoir connection (108) is positioned in each spatial region of the pump housing (22) for the first brake circuit (20) in which the storage opening (106) is positioned for the second brake circuit (18). [6] Pump housing according to one of claims 2 to 5, wherein the pump housing (22) has a second side surface (96) with at least two inlet valve openings (98) and at least two outlet valve openings (100) which extends substantially perpendicular to the first side surface (104). [7] Pump housing according to claim 6, wherein at least one further opening (102) for a high-pressure switching valve (26), a changeover valve (28), an outlet control valve (64) and / or a separating valve (76) is provided on the second side surface (96). [8] Pump housing according to one of claims 1 to 7, in which a pressure sensor connection is provided, which is assigned in particular to each brake circuit of two brake circuits (18, 20), to which the reservoir connection (108) is also assigned. [9] Pump housing according to claim 8, wherein the pressure sensor connection of a plurality of side surfaces of the pump housing is positioned on that side surface (96) on which at least two inlet valve openings (98) and at least two outlet valve openings (100) are also provided. [10] Use of a pump housing (22) according to one of claims 1 to 9 in a vehicle brake system (10), wherein a connecting line (60) to a reservoir (62) of the vehicle brake system (10) is connected to the pump housing (22) at its reservoir connection (108) and two brake circuits (18, 20) are formed with the pump housing (22), characterized bythat the reservoir connection (108) is assigned to a first of the two brake circuits (20).

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