| 摘要 |
PURPOSE: To manufacture a pressure sensor easily and inexpensively by covering a diaphragm for forming the switch of the pressure sensor with nickel. CONSTITUTION: The pressure sensor 13 has a sensor casing 20, and a pressure room 21 for detecting tire pressure is provided in the casing 20. The pressure room 21 is formed of CrNi stainless steel casing 22 and CrNi stainless steel diaphragm 23. Also, a contact pin 24 is electrically insulated and is extended near the diaphragm 23 through the inside of the casing and constitutes an electrical switch 25 along with the diaphragm 23. When a tire pressure goes below a specific value, the diaphragm 23 is lifted from the contact pin 24, and the switch 25 generates a signal. A nickel layer 30 that electrochemically or chemically covers the diaphragm 23 has a large conductivity and cannot be oxidized easily so that the switch 25 functions positively. |
