Magnetostrictive element for measuring knock in engines
First Claim
1. A method for measuring and evaluating combustion knocking during operation of an externally-ignited combustion engine having a combustion chamber in which a physical magnitude changes during combustion knocking, the method comprising providing a magnetostrictive element having a maximum diameter of 2 mm and a length-to-diameter ratio of more than 100 in communication on with the combustion chamber, measuring pressure changes occurring during knocking which have frequencies of greater than 100 kHz with the magnetostrictive element, and transferring such measurements to a processing apparatus for the engine.
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Accused Products
Abstract
A method and device for measuring combustion knocking in the combustion chamber of an externally-ignited internal combustion engine, the device comprising a magnetostrictive element with a maximum diameter of 2 mm and a length-to-diameter ratio of greater than 100, the device being mounted in the engine so as to be exposed to the combustion chamber. The device can include a coil to which the magnetostrictive element is connected for converting changes in magnetic conductability in the magnetostrictive element, due to pressure increases in the combustion chamber to which it is exposed, into electrical signals. The coil in turn can be connected to an electronic switching system for the engine.
11 Citations
19 Claims
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1. A method for measuring and evaluating combustion knocking during operation of an externally-ignited combustion engine having a combustion chamber in which a physical magnitude changes during combustion knocking, the method comprising providing a magnetostrictive element having a maximum diameter of 2 mm and a length-to-diameter ratio of more than 100 in communication on with the combustion chamber, measuring pressure changes occurring during knocking which have frequencies of greater than 100 kHz with the magnetostrictive element, and transferring such measurements to a processing apparatus for the engine.
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2. A method for measuring and evaluating combustion knocking during operation of an externally-ignited combustion engine having a combustion chamber in which a physical magnitude changes during combustion knocking, the method comprising providing a magnetostrictive element having a maximum diameter of 2 mm and a length-to-diameter ratio of more than 100 in communcation on with the combustion chamber, measuring pressure increases occuring during knocking which are greater than 10 bar/microsecond with the magnetostrictive element, and transferring such measurements to a processing apparatus for the engine.
- 3. A device for measuring combustion chamber in a combustion chamber of an externally-ignited combustion engine during operation thereof, the device comprising a magnetostrictive element with a maximum diameter of 2 mm and a length-to-diameter ratio of greater than 100, and having an end for exposure to said combustion chamber, and a vibration-decoupling material around said end of said magnetostrictive element for decoupling said magnetostrictive element from vibrations in the walls of said combustion chamber.
- 14. An externally-ignited internal combustion engine comprising a combustion chamber comprising a cylinder, a device for measuring a physical magnitude in said chamber which changes during combustion knocking, and a processing apparatus for said device, the device including a magnetostrictive element with a maximum diameter of 2 mm and a length-to-diameter ratio of more than 100.
Specification