Evaporative emission leak detection system with brushless motor
First Claim
1. An evaporative emission leak detection system for detecting a leakage of a fuel vapor evaporating in a fuel tank, the system comprising:
- a pump for providing a pressure difference between an inside and outside of the fuel tank;
a brushless motor for operating the pump;
a first passage having an adsorbent for adsorbing the fuel vapor, the first passage connecting to the fuel tank;
a second passage connecting to the outside of the fuel tank;
a switching device for switching connections between the pump and at least one of the first passage and the second passage;
a detector disposed in a passage between the pump and the switching device for detecting a pressure; and
a housing;
wherein the pump, the brushless motor, the switching device and the detector are accommodated in the housing.
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Accused Products
Abstract
An evaporative emission leak detection system provides for detecting a leakage of a fuel vapor evaporating in a fuel tank by using a pressure difference between an inside and outside of the fuel tank. The system includes a pump for providing the pressure difference between the inside and outside of the fuel tank, a brushless motor for operating the pump, a first passage connecting to the fuel tank, a second passage connecting to the outside of the fuel tank, and a switching device for switching connections between the pump and at least one of the first passage and the second passage. The first passage has an adsorbent for adsorbing the fuel vapor. This system ensures a long life time and high accuracy of the leak detection.
48 Citations
31 Claims
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1. An evaporative emission leak detection system for detecting a leakage of a fuel vapor evaporating in a fuel tank, the system comprising:
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a pump for providing a pressure difference between an inside and outside of the fuel tank; a brushless motor for operating the pump; a first passage having an adsorbent for adsorbing the fuel vapor, the first passage connecting to the fuel tank; a second passage connecting to the outside of the fuel tank; a switching device for switching connections between the pump and at least one of the first passage and the second passage; a detector disposed in a passage between the pump and the switching device for detecting a pressure; and a housing; wherein the pump, the brushless motor, the switching device and the detector are accommodated in the housing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An evaporative emission leak detection system for detecting a leakage of a fuel vapor evaporating in a fuel tank, the system comprising:
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a pump for providing a pressure difference between an inside and outside of the fuel tank; a brushless motor for operating the pump; a first passage having an adsorbent for adsorbing the fuel vapor, the first passage connecting to the fuel tank; a second passage connecting to the outside of the fuel tank; an electromagnetic switching device for switching connections between the pump and at least one of the first passage and the second passage; a housing; and a load detector for detecting a load of the brushless motor as an operation characteristic of the pump; wherein the pump, the brushless motor and the electromagnetic switching device are accommodated in the housing. - View Dependent Claims (15, 16, 17)
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18. An evaporative emission leak detection system for detecting a leakage of a fuel vapor evaporating in a fuel tank, the system comprising:
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a pump for providing a pressure difference between an inside and outside of the fuel tank; a brushless motor for operating the pump; a first passage having an adsorbent for adsorbing the fuel vapor, the first passage connecting to the fuel tank; and a second passage connecting to the outside of the fuel tank; and a switching device for switching connections between the pump and at least one of the first passage and the second passage; wherein the pump and the brushless motor are disposed at a higher position than the fuel tank and the adsorbent.
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19. A method of detecting a leakage of a fuel vapor evaporating in a fuel tank, the method comprising:
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providing a pressure difference between an inside and outside of the fuel tank through operation of a pump; operating the pump using a brushless motor; adsorbing the fuel vapor with an adsorbent in a first passage connected to the fuel tank; connecting a second passage to the outside of the fuel tank; switching connections between the pump and at least one of the first passage and the second passage; and disposing the pump and the brushless motor at a higher position than the fuel tank and the adsorbent.
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20. A method of detecting a leakage of a fuel vapor evaporating in a fuel tank, the method comprising:
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providing a pressure difference between an inside and outside of the fuel tank through operation of a pump; operating the pump using a brushless motor; adsorbing the fuel vapor with an adsorbent in a first passage connected to the fuel tank; connecting a second passage to the outside of the fuel tank; switching connections between the pump and at least one of the first passage and the second passage; detecting a pressure using a pressure detector in a passage between the pump and a switch that performs said switching; detecting a load of the brushless motor as an operation characteristic of the pump; and arranging at least the brushless motor, the pressure detector and the pump in a housing. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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30. An evaporative emission leak detection system for detecting a leakage of a fuel vapor evaporating in a fuel tank, the system comprising:
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a pump for providing a pressure difference between an inside and outside of the fuel tank; a motor for operating the pump; a first passage having an adsorbent for adsorbing the fuel vapor, the first passage connecting to the fuel tank; a second passage connecting to the outside of the fuel tank; and a switching device for switching connections between the pump and at least one of the first passage and the second passage; wherein the pump and the motor are disposed at a higher position than the fuel tank and the adsorbent.
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31. A method of detecting a leakage of a fuel vapor evaporating in a fuel tank, the method comprising:
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providing a pressure difference between an inside and outside of the fuel tank through operation of a pump; operating the pump using a motor; adsorbing the fuel vapor with an adsorbent in a first passage connected to the fuel tank; connecting a second passage to the outside of the fuel tank; switching connections between the pump and at least one of the first passage and the second passage; and disposing the pump and the motor at a higher position than the fuel tank and the adsorbent.
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Specification