Method and apparatus for detecting combustion pressure in engine
First Claim
1. A combustion chamber pressure detecting apparatus comprising a combustion pressure detecting sensor which includes a diaphragm with a light reflecting surface which is deformable under the combustion pressure in the engine, light emitting means, light detecting means, optical fibers for introducing light from the light emitting means to the reflecting surface and introducing light reflected from said reflecting surface to the light detecting means, means for detecting said combustion pressure from the output of said light detecting means, comparator means for receiving as an input the output of the detecting means and as another input a reference value, said comparator means comparing the inputs applied thereto and producing a correcting signal on the basis of the output of the light detecting means at a predetermined angle of rotation of the engine, and means for applying the correcting signal to said light emitting means whereby the difference in value of the inputs to the comparator means are brought to zero.
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Accused Products
Abstract
A combustion pressure detecting apparatus for generating an electrical signal in response to a combustion pressure of an internal combustion engine, wherein an electrical signal based on said combustion pressure is detected at a predetermined angle of rotation of said engine, the detected value being compared with a predetermined reference value to derive a difference therebetween, including correcting means for executing correcting operations in dependence on said difference.
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Citations
10 Claims
- 1. A combustion chamber pressure detecting apparatus comprising a combustion pressure detecting sensor which includes a diaphragm with a light reflecting surface which is deformable under the combustion pressure in the engine, light emitting means, light detecting means, optical fibers for introducing light from the light emitting means to the reflecting surface and introducing light reflected from said reflecting surface to the light detecting means, means for detecting said combustion pressure from the output of said light detecting means, comparator means for receiving as an input the output of the detecting means and as another input a reference value, said comparator means comparing the inputs applied thereto and producing a correcting signal on the basis of the output of the light detecting means at a predetermined angle of rotation of the engine, and means for applying the correcting signal to said light emitting means whereby the difference in value of the inputs to the comparator means are brought to zero.
- 3. In an internal combustion engine, a chamber pressure detecting apparatus comprising a light sensor means, a portion of said light sensor means being positioned in the combustion chamber for detecting pressure in said chamber, a comparator having one input thereof connected to receive signals from the light sensor means and another input thereof connected to receive a reference signal value, and timing means for enabling an electrical signal from the light sensor means representative of a known combustion pressure produced at a predetermined angle of rotation of said engine to be applied to the comparator, whereby said electrical signal is compared with said reference signal value by said comparator to produce a difference value and an output of said comparator is connected to means for adjusting the light sensor means to bring said difference value toward zero so that error in said apparatus when detecting another electrical signal produced at pressures other than said known pressure is reduced.
- 7. A method of detecting pressure in an internal combustion engine by apparatus for generating an electrical signal representative of a known combustion pressure at a predetermined angle of rotation of said engine and another electrical signal representative of a pressure at an angle of rotation of said engine other than said predetermined angle, including the steps of using a light sensor means, a portion of said light sensor means being positioned in the combustion chamber for detecting pressure in said chamber and to produce said electrical signal based on the combustion pressure at said predetermined angle of rotation of said engine, comparing the electrical signal with a predetermined reference signal value to derive a difference signal therebetween, and using said difference signal to vary the operating parameters of said light sensor means to bring said difference signal toward zero so that error in the apparatus is reduced when said another electrical signal is generated.
Specification