Method and apparatus for predicting life of air filter cartridges
First Claim
1. Method of predicting the remaining service life of an air filter element for the combustion air induction system of an internal combustion engine powering a motor vehicle, said filter element having a maximum permitted pressure drop across the filter element representing the maximum service life of said element at which pressure drop said element is no longer usable, means for measuring the pressure drop across said filter element, and means for establishing the usage of said filter element from the initial use of such filter element, comprising the steps of measuring the pressure drop across the filter element at the end of successive usage intervals, memorizing the pressure drop and the usage at the end of each such usage interval, determining from the pressure drop measured at the end of each usage interval and the accumulated usage at the end of each such usage interval the rate at which the pressure drop is increasing, determining from said rate of increase the predicted usage at which said maximum permitted pressure drop will occur, and selectively displaying the usage at which the maximum pressure drop will occur.
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Accused Products
Abstract
A method and apparatus for predicting the remaining service life of an air filter element reads the pressure drop across the filter element at regular usage intervals (such as engine run time or distance the vehicle has traveled). An approximation of the rate at which the pressure drop is increasing is made, which is used to calculate the usage at which the maximum pressure drop will be attained.
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Citations
12 Claims
- 1. Method of predicting the remaining service life of an air filter element for the combustion air induction system of an internal combustion engine powering a motor vehicle, said filter element having a maximum permitted pressure drop across the filter element representing the maximum service life of said element at which pressure drop said element is no longer usable, means for measuring the pressure drop across said filter element, and means for establishing the usage of said filter element from the initial use of such filter element, comprising the steps of measuring the pressure drop across the filter element at the end of successive usage intervals, memorizing the pressure drop and the usage at the end of each such usage interval, determining from the pressure drop measured at the end of each usage interval and the accumulated usage at the end of each such usage interval the rate at which the pressure drop is increasing, determining from said rate of increase the predicted usage at which said maximum permitted pressure drop will occur, and selectively displaying the usage at which the maximum pressure drop will occur.
- 9. Apparatus for predicting the remaining service life of an air filter element for filtering the combustion air of an internal combustion engine for powering a motor vehicle comprising means for measuring the pressure differential across said filter element and generating a signal proportional thereto, means for measuring usage of the engine, a read only memory connected to said pressure differential measuring means, a microprocessor connected to said read only memory, said usage measuring means, and a display device, said microprocessor including means causing said read only memory to record the value of said signal at the end of usage intervals measured by said usage measuring means and being programmed to calculate the rate of increase of said pressure differential across said filter element and to calculate the usage at which a predetermined pressure drop across the filter element will be attained, said display device being caused by said microprocessor to display the difference between the usage at which the predetermined pressure drop will be attained and the usage recorded at the time the calculation is made.
Specification