Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
214 words
A fuel injection timing detecting apparatus for Diesel engines comprising: a preliminarily-magnetized pressure pin disposed within a body of a fuel injection nozzle of a Diesel engine and responsive to a pressure of pressurized fuel supply to be displaced against a spring force of a pressure spring which is in engagement with said pressure pin; magnetic sensing means disposed outside of said fuel injection nozzle body and fixed to the same to sense a magnetic variation caused by the displacement of said pressure pin, thereby detecting the displacement of said pressure pin; and a signal processing circuit for amplifying and processing an output signal of said magnetic sensing means, wherein said magnetic sensing means comprises a flux-gate magnetometer including a toroidal magnetic core, an excitation coil and a sensing coil wound on said magnetic core; said signal processing circuit includes an excitation circuit including an oscillator circuit for generating an exciting signal having a predetermined frequency and supplied to said excitation coil and a detecting circuit responsive to an output signal of said sensing coil to generate a detection signal indicative of a magnetic variation caused by the displacement of said pressure pin; and all the component parts of said fuel injection timing detecting apparatus other than said magnetic sensing means are magnetically shielded.
Claim 2
Dependent Claim
214 words
A fuel injection timing detecting apparatus for Diesel engines comprising: a preliminarily-magnetized pressure pin disposed within a body of a fuel injection nozzle of a Diesel engine and responsive to a pressure of pressurized fuel supply to be displaced against a spring force of a pressure spring which is in engagement with said pressure pin; magnetic sensing means disposed outside of said fuel injection nozzle body and fixed to the same to sense a magnetic variation caused by the displacement of said pressure pin, thereby detecting the displacement of said pressure pin; and a signal processing circuit for amplifying and processing an output signal of said magnetic sensing means, wherein said magnetic sensing means comprises a flux-gate magnetometer including a toroidal magnetic core, an excitation coil and a sensing coil wound on said magnetic core; said signal processing circuit includes an excitation circuit including an oscillator circuit for generating an exciting signal having a predetermined frequency and supplied to said excitation coil and a detecting circuit responsive to an output signal of said sensing coil to generate a detection signal indicative of a magnetic variation caused by the displacement of said pressure pin; and all the component parts of said fuel injection timing detecting apparatus other than said magnetic sensing means are magnetically shielded.
Claim 3
Dependent Claim
24 words
An apparatus according to claim 1, wherein each of said fuel injection nozzle body and said pressure spring is made of a nonmagnetic material.
Claim 4
Dependent Claim
193 words
A fuel-injection timing detecting apparatus for a Diesel engine comprising: a fuel injection nozzle body mounted on said Diesel engine and including therein a nozzle for opening in response to the pressurized fuel to effect fuel injection, a movable member associated with said nozzle and a spring engaged with said movable member for normally biasing said nozzle in a closed position via said movable member, said movable member being magnetized to provide a magnetic field; a magnetic sensor positioned outside said fuel injection nozzle body to be responsive to the magnetic field provided by said movable member, said magnetic sensor including a magnetic core, an excitation coil and a sensing coil wound on said core, said excitation coil being excited periodically to provide a periodic magnetic field, and said sensing coil generating an electric signal corresponding to the composite magnitude of said magnetic fields provided by said movable member and said excitation coil; a sample-hold circuit for sample-holding said electric signal in synchronism with each excitation of said excitation coil; and a pulse circuit for generating a pulse indicative of the fuel injection timing when said sample-held electric signal reaches a predetermined level.
Claim 5
Dependent Claim
193 words
A fuel-injection timing detecting apparatus for a Diesel engine comprising: a fuel injection nozzle body mounted on said Diesel engine and including therein a nozzle for opening in response to the pressurized fuel to effect fuel injection, a movable member associated with said nozzle and a spring engaged with said movable member for normally biasing said nozzle in a closed position via said movable member, said movable member being magnetized to provide a magnetic field; a magnetic sensor positioned outside said fuel injection nozzle body to be responsive to the magnetic field provided by said movable member, said magnetic sensor including a magnetic core, an excitation coil and a sensing coil wound on said core, said excitation coil being excited periodically to provide a periodic magnetic field, and said sensing coil generating an electric signal corresponding to the composite magnitude of said magnetic fields provided by said movable member and said excitation coil; a sample-hold circuit for sample-holding said electric signal in synchronism with each excitation of said excitation coil; and a pulse circuit for generating a pulse indicative of the fuel injection timing when said sample-held electric signal reaches a predetermined level.