EVAPORATIVE FUEL PROCESSING SYSTEM

• US 20150285170A1
• Filed: 03/30/2015
• Published: 10/08/2015
• Est. Priority Date: 04/07/2014
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: NANBA, Kunio
• Granted Patent: US 9,689,325 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02D 2200/021 Engine temperature
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 41/004 Control of the valve or purge actuator, e.g. duty cycle, closed loop control of position

Abstract

A purge pump is installed in a purge conduit, which forms a purge passage that communicates between an inside of a canister and an air intake passage. When a pressure of the air intake passage is equal to or smaller than a predetermined pressure, a large quantity of evaporative fuel, which is larger than a predetermined purge quantity, is introduced into the air intake passage. At this time, a pump electric power supply device supplies a relatively small amount of the electric power to the purge pump to run the purge pump. When the pressure of the air intake passage is larger than the predetermined pressure, the purge pump is driven to pump the evaporative fuel into the air intake passage. At that time, the pump electric power supply device supplies a relatively large amount of the electric power to the purge pump.

Claims

1. An evaporative fuel processing system that guides evaporative fuel generated in an inside of a fuel tank, which stores fuel of an internal combustion engine, to an air intake system of the internal combustion engine, the evaporative fuel processing system comprising:

a canister that is communicated with the inside of the fuel tank and recovers the evaporative fuel of the fuel tank;

a purge conduit that forms a purge passage, which communicates between an inside of the canister and an air intake passage of the air intake system;

a purge valve that is installed in the purge conduit to communicate or discommunicate between the inside of the canister and the air intake passage;

a purge valve control device that controls the purge valve to open or close the purge valve;

a purge pump that is installed in one of;

an atmosphere communication conduit, which forms an atmosphere communication passage that communicates between the inside of the canister and atmosphere; and

the purge conduit, wherein the purge pump pumps the evaporative fuel, which is recovered by the canister, to the air intake system;

a pump electric power supply device that supplies an electric power to the purge pump; and

a pressure sensing device that senses a pressure of the air intake passage and outputs a signal, which corresponds to the pressure of the air intake passage, wherein;

the pump electric power supply device supplies the electric power to the purge pump to form a flow of gas from the inside of the canister to the air intake passage during a running period of the internal combustion engine; and

the pump electric power supply device changes an amount of the electric power supplied to the purge pump based on the signal outputted from the pressure sensing device at a time of opening the purge valve during the running period of the internal combustion engine.

2. The evaporative fuel processing system according to claim 1, wherein the purge pump is installed in the atmosphere communication conduit.

3. The evaporative fuel processing system according to claim 1, wherein:

when the pressure of the air intake passage is larger than a predetermined pressure, the pump electric power supply device supplies a relatively large amount of the electric power to the purge pump to increase a quantity of the evaporative fuel, which is supplied from the canister to the air intake passage, beyond a predetermined purge quantity; and

when the pressure of the air intake passage is smaller than the predetermined pressure, the pump electric power supply device supplies a relatively small amount of the electric power to the purge pump to run the purge pump synchronously with a flow of the gas in the purge passage.

4. The evaporative fuel processing system according to claim 1, comprising a coolant temperature sensing device that senses a temperature of a coolant fluid of the internal combustion engine and outputs a signal, which corresponds to the temperature of the coolant fluid, to the purge valve control device, wherein:

the purge valve control device controls the purge valve to open or close the purge valve based on the signal outputted from the coolant temperature sensing device.