Fuel vapor recovery apparatus

Patent metadata

Field	Value
Publication number	US-2016258389-A1
Application number	US-201615010743-A
Country	US
Kind code	A1
Filing date	Jan 29, 2016
Priority date	Mar 6, 2015
Publication date	Sep 8, 2016
Grant date	—

Abstract

A fuel vapor recovery apparatus includes an adsorbent canister capable of capturing fuel vapor, a vapor passage connecting the adsorbent canister to a fuel tank. In addition, the apparatus includes an atmospheric air passage communicating the adsorbent canister with the atmosphere, a purge passage coupling the adsorbent canister to an intake pipe of an internal combustion engine, a purge pump configured to generate a gas flow from the adsorbent canister to the intake pipe through the purge passage, and a flow control valve provided at the purge passage downstream of the purge pump in a direction of the gas flow and configured to regulate the gas flow through the purge passage. Further, the apparatus includes a decompressor configured to decrease pressure upstream of the flow control valve when the pressure upstream of the flow control valve in the direction of the gas flow is higher than the atmospheric pressure.

First claim

What is claimed is:

1 . A fuel vapor recovery apparatus comprising:
an adsorbent canister capable of capturing fuel vapor; a vapor passage connecting the adsorbent canister to a fuel tank; an atmospheric air passage communicating the adsorbent canister with the atmosphere; a purge passage coupling the adsorbent canister to an intake pipe of an internal combustion engine; a purge pump configured to generate a gas flow from the adsorbent canister to the intake pipe through the purge passage; a flow control valve provided at the purge passage downstream of the purge pump in a direction of the gas flow and configured to regulate the gas flow through the purge passage; and a decompressor configured to decrease pressure upstream of the flow control valve in the direction of the gas flow when the pressure upstream of the flow control valve in the direction of the gas flow is higher than the atmospheric pressure.

2 . The fuel vapor recovery apparatus according to claim 1 , wherein the decompressor is configured to carry out at least one of decreasing a rotation number of the purge pump, decreasing pressure in the intake pipe of the engine, and increasing a valve opening amount of the flow control valve in order to decrease the pressure upstream of the flow control valve.

3 . The fuel vapor recovery apparatus according to claim 1 , further comprising:
a pressure sensor configured to measure the pressure upstream of the flow control valve in the direction of the gas flow, wherein the purge pump is provided at the purge passage; wherein the pressure sensor is located at the purge passage between the flow control valve and the purge pump.

4 . The fuel vapor recovery apparatus according to claim 1 , wherein the decompressor is configured to estimate the pressure upstream of the flow control valve based on a valve opening amount of the flow control valve, a rotation number of the purge pump, and pressure in the intake pipe of the engine.

5 . The fuel vapor recovery apparatus according to claim 4 ,
wherein the decompressor stores a map that is prepared based on a relationship between the pressure upstream of the flow control valve, the valve opening amount of the flow control valve, the rotation number of the purge pump, and the pressure in the intake pipe of the engine, and wherein the decompressor is configured to estimate the pressure upstream of the flow control valve based on the map.

Assignees

• Aisan Ind

Inventors

• Makino Katsuhiko

Classifications

• F02M25/089 Primary

  Layout of the fuel vapour installation · CPC title

• F02M25/0854

  Details of the absorption canister · CPC title

• F02M25/0836 Primary

  Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold · CPC title