Valve position detector
First Claim
1. A valve position detector for detecting a position of a poppet valve driven by a valve operating mechanism, a valve stem of said valve being slidably supported by a cylinder head, said detector comprising:
- a variable capacitance electrode of an electrostatic capacitance sensor configured for detecting a position of said valve by detecting a variation in electrostatic capacitance when said valve is moved, said variable capacitance electrode being provided between said cylinder head or a stationary member integrally formed therewith, and said valve or a member which follows said valve, wherein an electromagnetic actuator is provided to move the valve up and down, and wherein an external thread is formed at a lower end of said electromagnetic actuator, and an external thread is formed at an upper end valve, and wherein said two external threads are connected by a connecting member, said variable capacitance electrode comprising a fixed electrode carried by the cylinder block and a moving electrode carried by the valve to form an electrostatic capacitance valve displacement sensor.
0 Assignments
0 Petitions
Accused Products
Abstract
A poppet valve moves up and down in a valve operating mechanism in an internal combustion engine. A cylindrical fixed electrode is fixed to a support plate on a cylinder head, and a cylindrical moving electrode is mounted to the lower surface of a valve spring retainer which is mounted to the poppet valve via a cotter. The fixed electrode is connected to a circuit which comprises a variable condenser and a resistance. The valve moves up and down during firing operation of the engine. Thus, variation in electrostatic capacity is detected by the two electrodes, transmitted to a circuit via a lead mounted to the fixed electrode, and converted to a voltage by the circuit, thereby detecting valve position exactly.
30 Citations
3 Claims
-
1. A valve position detector for detecting a position of a poppet valve driven by a valve operating mechanism, a valve stem of said valve being slidably supported by a cylinder head, said detector comprising:
a variable capacitance electrode of an electrostatic capacitance sensor configured for detecting a position of said valve by detecting a variation in electrostatic capacitance when said valve is moved, said variable capacitance electrode being provided between said cylinder head or a stationary member integrally formed therewith, and said valve or a member which follows said valve, wherein an electromagnetic actuator is provided to move the valve up and down, and wherein an external thread is formed at a lower end of said electromagnetic actuator, and an external thread is formed at an upper end valve, and wherein said two external threads are connected by a connecting member, said variable capacitance electrode comprising a fixed electrode carried by the cylinder block and a moving electrode carried by the valve to form an electrostatic capacitance valve displacement sensor. - View Dependent Claims (2, 3)
Specification