Fuel vapor leak detecting apparatus, and fuel supplying apparatus to be applied to the same
First Claim
1. A fuel vapor leak detecting apparatus, comprising:
- a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system;
a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and
an internal-pressure measuring section which detects an internal pressure of the vapor purge system;
wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that a leak occurs, andwherein the pressurizing section is a jet pump using a gasoline flow from a fuel pump which is submerged in the fuel tank.
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Accused Products
Abstract
A fuel vapor leak detecting apparatus, includes: a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system. The pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed. When the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that leak occurs.
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Citations
16 Claims
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1. A fuel vapor leak detecting apparatus, comprising:
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a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system; wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that a leak occurs, and wherein the pressurizing section is a jet pump using a gasoline flow from a fuel pump which is submerged in the fuel tank. - View Dependent Claims (2, 3)
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4. A fuel vapor leak detecting apparatus, comprising:
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a bypass valve which is openable and closable, which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which bypasses a two-way valve interposed between the fuel tank and the canister; a reference orifice which is connected in series to the bypass valve; a communication valve which controls communication between the canister and an ambient area; a pressurizing section which introduces atmospheric air into the fuel tank; and an internal-pressure measuring section which detects an internal pressure of the fuel tank; wherein a reference pressure rise rate at a timing when the pressurizing section supplies the air for a second predetermined time in a state where the communication valve and the bypass valve are opened is set, and, when a pressure rise rate at a timing when a time which is twice the second predetermined time has elapsed after the communication valve is closed is equal to or smaller than the reference pressure rise rate, it is judged that a leak occurs. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11)
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12. A fuel vapor leak detecting apparatus, comprising:
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a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system; wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that a leak occurs, wherein an elapsed time from beginning of pressurization to a time when a difference in a pressure rise rate between two pressure rise curves becomes large is set as a second predetermined time, the two pressure rise curves being respectively in cases where a leak hole corresponding to leak criterion exists, and where a leak hole does not exist, a pressure rise rate at a timing of an elapse of the second predetermined time in the case where a leak hole exists is previously stored as a predetermined pressure rise rate, and, when a pressure rise rate in a case where the pressurizing section performs pressurization for the second predetermined time in a state where the vapor purge system is closed is equal to or smaller than the predetermined pressure rise rate, it is judged that a leak occurs.
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13. A fuel vapor leak detecting apparatus, comprising:
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a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system; wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that a leak occurs, and wherein the pressurizing section is a jet pump using a discharge flow from a pressure regulator which adjusts a pressure of gasoline supplied from a fuel pump submerged in the fuel tank to the internal combustion engine.
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14. A fuel vapor leak detecting apparatus, comprising:
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a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system; wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that leak occurs, and wherein the pressurizing section is a jet pump using a flow of return gasoline which is residual as a result of consumption of gasoline in the internal combustion engine, the gasoline being supplied from a fuel pump submerged in the fuel tank to the internal combustion engine.
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15. A fuel vapor leak detecting apparatus, comprising:
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a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; and an internal-pressure measuring section which detects an internal pressure of the vapor purge system; wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that leak occurs, and wherein the fuel tank is a saddle type fuel tank and a jet pump is provided which transfers gasoline from a chamber of the saddle type fuel tank by a flow of excess gasoline from a fuel pump, the jet pump functions as the pressurizing section by, when a leak is detected, switching a suction portion of the jet pump to a pipe for introducing atmospheric air.
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16. A fuel vapor leak detecting apparatus, comprising:
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a valve which is in a vapor purge system including a canister that is communicated with a fuel tank and an internal combustion engine, and which controllably closes the vapor purge system; a bypass valve which is openable and closable, and which bypasses a two-way valve interposed between the fuel tank and the canister; a pressurizing section which introduces atmospheric air into the vapor purge system to pressurize the vapor purge system; an internal-pressure measuring section which detects an internal pressure of the vapor purge system; a reference orifice which is connected in series to the bypass valve; and a communication valve which controls communication between the canister an ambient area; wherein the pressurizing section supplies the air for a predetermined time in a state where the vapor purge system is closed, and, when the internal pressure measured by the internal-pressure measuring section at the air supply is equal to or lower than a preset criterion pressure, it is judged that a leak occurs, wherein the pressurizing section is a jet pump using a gasoline flow from a fuel pump which is submerged in the fuel tank, wherein a reference pressure rise rate at a timing when the pressurizing section supplies the air for a second predetermined time in a state where the communication valve and the bypass valve are opened is set, and when a pressure rise rate at a timing when a time which is twice the second predetermined time has elapsed after the communication valve is closed is equal to or smaller than the reference pressure rise rate, it is judged that a leak occurs.
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Specification