| 摘要 |
Disclosed is a built in warning device for monitoring tire pressure wherein a housing (1) is provided with a reference chamber (4) therein an inlet pipe (402) is extended from the reference chamber (4) to a valve stem (2) the inlet pipe (402) is provided therein with a reference chamber valve (7) able to seal and open the inlet pipe (402) and a valve core (702) of the reference chamber valve (7) is directly abutted tightly against a core stem (301) of a valve core (3). When inflating the valve core (3) is pushed to be open the core stem (301) of the valve core (3) is pushed against the valve core (702) and then the reference chamber valve (7) is opened such that the reference chamber (4) is inflated. After the inflation is accomplished the valve core (3) is restored and the reference chamber valve (7) is closed such that the reference chamber (4) is sealed off. When the pressure within the tire is much lower an elastic metal film (401) of the reference chamber wall face can form an outward deformation due to the pressure difference and when the deformed film comes into contact with the anode contact point of an alarm signal transmitting module (5) the alarm signal transmitting module (5) is electrified and sends out a signal then the signal is received by the warning device on board a vehicle and an alarm is sent out thereby. The warning device is of mechanical sensing type has a stable and reliable operation can be used in a severe operation environment has a low failure rate and further has relatively low costs. |
