Control device for a motor vehicle

• US 20050109156A1
• Filed: 11/24/2004
• Published: 05/26/2005
• Est. Priority Date: 11/24/2003
• Status: Active Grant

• Current Assignee: Melecs EWS GmbH & Co. KG
• Original Assignee: Siemens AG
• Inventors: Neumann, Gerhard, Hellinger, Leopold
• Granted Patent: US 7,174,778 B2
• Time in Patent Office: Days
• US Class Current: 74/608
• CPC Class Codes: B60R 16/0239 Electronic boxes
• CPC Class Codes: F16H 2059/683 Sensing pressure in control systems or in fluid controlled devices, e.g. by pressure sensors for hydrostatic transmissions F16H2059/6861
• CPC Class Codes: F16H 59/68 Inputs being a function of gearing status
• CPC Class Codes: F16H 61/0006 Electronic control units for transmission control, e.g. connectors, casings or circuit boards
• CPC Class Codes: H05K 5/0082 specially adapted for transmission control units, e.g. gearbox controllers
• CPC Class Codes: Y10T 74/219 Guards

Abstract

Control device for a motor vehicle, particularly for controlling a gearbox, with an electronic control circuit arranged on a support plate in a housing; for measurement of the hydraulic pressure, a measuring transducer is connected to a hydraulic unit of the gearbox by a pressure channel, wherein a spring element is formed in a region of the support plate and is a portion of the measuring transducer; the spring element is connected for force transmission via a connecting member to a diaphragm which sealingly spans the aperture of the pressure channel leading to the spring element.

Claims

1. A control device for a motor vehicle gearbox, comprising:

a support plate in a housing;

an electronic control circuit provided on the support plate;

a pressure channel connected to a hydraulic unit of the gearbox, the pressure channel having an aperture;

a measuring transducer for measuring hydraulic pressure in the pressure channel, the measuring transducer having a spring element formed in the vicinity of the support plate;

a diaphragm which sealingly spans over the aperture of the pressure channel; and

a connecting element to connect the spring element to the diaphragm for force transmission.

2. The device according to claim 1, wherein

edge cuts are present in the support plate to define a tongue in the support plate, and

the spring element is formed from the tongue.

3. The device according to claim 1, wherein

a strain gauge strip is installed on the spring element to detect deflection of the spring element.

4. The device according to claim 1, further comprising:

a permanent magnet provided on the spring element; and

a magnetic field dependent sensor provided on the support plate to detect deflection of the spring element through the permanent magnet.

5. The control device according to claim 1, wherein

the housing has a base provided on a wall of the gearbox,

the gearbox has an aperture,

the pressure channel is formed from a hollow cylindrical projection from the base of the housing, the hollow cylindrical projection projecting through the aperture in the gearbox.

6. The control device according to claim 5, wherein the diaphragm, the connecting member and the base of the housing are produced integrally as an injection molded part.

7. The control device according to claim 5, wherein

the base of the housing has a floor plate, and

the diaphragm extends through the hollow cylindrical projection in the vicinity of the floor plate.

8. The control device according to claim 6, wherein

the diaphragm is injection molded into the hollow cylindrical projection, and

the diaphragm is formed from a polymeric material which has a Shore hardness smaller than the Shore hardness of the material of the base of the housing.

9. The control device according to claim 5, wherein annular grooves for receiving annular sealing elements are provided on an outer envelope surface of the hollow cylindrical projection.

10. The control device according to claim 1, wherein

the pressure channel has an end that extends away from the hydraulic unit, and

the end of the pressure channel conducts hydraulic fluid in a direction substantially perpendicular to the plane of the support plate.

11. The control device according to claim 1, wherein

the housing has a base,

the support plate is connected to the base of the housing with screws provided in the vicinity of the pressure channel.

12. The device according to claim 1, wherein the spring element is formed from a portion of the support plate.

13. The device according to claim 12, wherein

edge cuts are present in the support plate to define a tongue in the support plate, and the spring element is formed from the tongue.

14. The device according to claim 13, wherein

a strain gauge strip is installed on the spring element to detect deflection of the spring element.

15. The device according to claim 14, further comprising:

a permanent magnet provided on the spring element; and

a magnetic field dependent sensor provided on the support plate to detect deflection of the spring element through the permanent magnet.

16. The control device according to claim 15, wherein

the housing has a base provided on a wall of the gearbox,

the gearbox has an aperture,

the pressure channel is formed from a hollow cylindrical projection from the base of the housing, the hollow cylindrical projection projecting through the aperture in the gearbox.

17. The control device according to claim 16, wherein the diaphragm, the connecting member and the base of the housing are produced integrally as an injection molded part.

18. The control device according to claim 17, wherein

the base of the housing has a floor plate, and

the diaphragm extends through the hollow cylindrical projection so as to be substantially co-planar with the floor plate.

19. The control device according to claim 18, wherein

the diaphragm is injection molded into the hollow cylindrical projection, and

the diaphragm is formed from a polymeric material which has a Shore hardness smaller than the Shore hardness of the base of the housing.

20. The control device according to claim 19, wherein annular grooves for receiving annular sealing elements are provided on an outer envelope surface of the hollow cylindrical projection.

21. The control device according to claim 20, wherein

the pressure channel has an end that extends away from the hydraulic unit of the gearbox, and

the end of the pressure channel conducts hydraulic fluid in a direction substantially perpendicular to the plane of the support plate.

22. The control device according to claim 21, wherein

the housing has a base,

the support plate is connected to the base of the housing with screws provided in the vicinity of the pressure channel.