Pressure measuring unit and connection unit for a motor vehicle transmission

Abstract

The example embodiment relates to a pressure measuring unit for determining the oil pressure in a motor vehicle transmission, including a circuit carrier, a pressure sensor, an electrical interface, a mechanical interface and a hydraulic interface. The pressure sensor is electrically connected to the circuit carrier by means of the electrical interface and mechanically connected to the circuit carrier by means of the mechanical interface on the first side of the circuit carrier. The hydraulic interface connecting the pressure measuring unit to a user hydraulic component is arranged on a side of the circuit carrier that is situated opposite the first side, and wherein an opening is arranged in the circuit carrier for pressure equalization between the pressure sensor and the hydraulic interface.

Claims

1. A pressure measuring unit for determining the oil pressure in a motor vehicle transmission, comprising a circuit carrier, a pressure sensor, an electrical interface, a mechanical interface and a hydraulic interface, wherein the pressure sensor is electrically connected to the circuit carrier by the electrical interface and mechanically connected to the circuit carrier by the mechanical interface on the first side of the circuit carrier, wherein the hydraulic interface configured to connect the pressure measuring unit to a user hydraulic component is arranged on a side of the circuit carrier that is situated opposite the first side, wherein an opening is arranged in the circuit carrier for pressure equalization between the pressure sensor and the hydraulic interface, an opening formed as part of the mechanical interface which is in fluid communication with the opening arranged in the circuit carrier; wherein the pressure sensor is embodied as a surface mount device (SMD) component.

2. The pressure measuring unit as claimed in claim 1, wherein the electrical interface comprises an electrical connecting part of the pressure sensor and a contact area of the circuit carrier.

3. The pressure measuring unit as claimed in claim 1, wherein the mechanical interface is an adhesive bond.

4. The pressure measuring unit as claimed in claim 1, wherein the circuit carrier is a constituent part of a transmission control unit.

5. A connection unit comprising: a pressure measuring, further comprising: a circuit carrier, a pressure sensor, an electrical interface, a mechanical interface and a hydraulic interface, wherein the pressure sensor is electrically connected to the circuit carrier by the electrical interface and mechanically connected to the circuit carrier by the mechanical interface on the first side of the circuit carrier, wherein the hydraulic interface configured to connect the pressure measuring unit to a user hydraulic component is arranged on a side of the circuit carrier that is situated opposite the first side, wherein an opening is arranged in the circuit carrier for pressure equalization between the pressure sensor and the hydraulic interface, an opening formed as part of the mechanical interface which is in fluid communication with the opening arranged in the circuit carrier; wherein the pressure sensor is embodied as a surface mount device (SMD) component; wherein a user hydraulic component is connected to the pressure measuring unit by the hydraulic interface.

6. The connection unit as claimed in claim 5, wherein the hydraulic interface is connected to the user hydraulic component in a gas- or liquid-tight manner with respect to its surroundings by an annular sealing part.

7. The connection unit as claimed in claim 5, the electrical interface further comprising an electrical connecting part of the pressure sensor and a contact area of the circuit carrier.

8. The connection unit as claimed in claim 5, the mechanical interface further comprising an adhesive bond.

9. The connection unit as claimed in claim 5, wherein the circuit carrier is a constituent part of a transmission control unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail below with reference to an example embodiment. In the associated drawings

(2) FIG. 1 shows a schematic illustration of the 1. pressure measuring unit, and

(3) FIG. 2 shows a schematic illustration of the 2. connection unit.

DETAILED DESCRIPTION

(4) FIG. 1 shows a pressure measuring unit 1 including a circuit carrier 2 and including a pressure sensor 3. The pressure measuring unit 1 also has an electrical, a mechanical and a hydraulic interface.

(5) The pressure sensor 3 is electrically connected to the circuit carrier 2 by means of the electrical interface 4 and mechanically connected to the circuit carrier 2 by means of the mechanical interface 5 on the first side 2.1 of the circuit carrier 2, here the top side. A pressure sensor which is embodied as an SMD component is used as the pressure sensor 3.

(6) Here, the electrical interface 4 has an electrical connecting part 4.1 of the pressure sensor 3, for example a leadframe, and a contact area 4.2 of the circuit carrier, for example a solder pad. For the sake of simplicity, the mechanical interface 5 is embodied by means of an adhesive bond here. For example, a standard epoxy resin may be used as the adhesive.

(7) The hydraulic interface 6 for connecting the pressure measuring unit 1 to a user hydraulic component is arranged on the side 2.2 of the circuit carrier 2 that is situated opposite the first side 2.1, here the bottom side.

(8) The hydraulic interface 6 may be implemented, for example, by the circuit carrier 2 or else by an additional component.

(9) An opening 2.3 is arranged in the circuit carrier 2 in order to enable pressure equalization between the pressure sensor 3 on the top side of the circuit carrier 2 and the hydraulic interface 6 on the bottom side of the circuit carrier 2. To this end, the adhesive bond 5 between the pressure sensor 3 and the circuit carrier 2 has a corresponding opening 5.1.

(10) FIG. 2 shows a connection unit with a pressure measuring unit 1 according to FIG. 1. A user hydraulic component 7 to be monitored is connected to the pressure measuring unit 1 by means of the hydraulic interface 6.

(11) To this end, the user hydraulic component 7 is fastened to the hydraulic interface 6 in a pressure-tight manner such that an external pressure cannot act on the pressure sensor 3. For this purpose, the hydraulic interface 6 is connected to the user hydraulic component 7 in a gas- or liquid-tight manner with respect to its surroundings by means of an annular sealing part 8. An elastic O-ring is used for the seal 8.