FUEL VAPOR RECOVERY APPARATUS

• US 20160258389A1
• Filed: 01/29/2016
• Published: 09/08/2016
• Est. Priority Date: 03/06/2015
• Status: Active Grant

• Current Assignee: Aisan Kogyo Kabushiki Kaisha
• Original Assignee: Aisan Kogyo Kabushiki Kaisha
• Inventors: MAKINO, Katsuhiko
• Granted Patent: US 9,989,019 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02M 25/0836 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

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.

Claims

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.