Flow rate control valve and fuel vapor processing apparatus including the same

Patent metadata

Field	Value
Publication number	US-9803593-B2
Application number	US-201414900724-A
Country	US
Kind code	B2
Filing date	Jun 26, 2014
Priority date	Jul 2, 2013
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A flow rate control valve includes: a valve casing forming a fluid passage; a valve seat provided in the fluid passage; a stepping motor; a valve guide stroke-controlled by the stepping motor via a feed screw mechanism; a valve body configured to be placed and separated on and from the valve seat; a connector connecting the valve guide and the valve body so as to allow them to move in an axial direction within a predetermined range; a valve spring biasing the valve body in a closing direction. When closing the valve body, ECU controls the motor to a closed state such that a connection between the valve guide and the valve body by the connector is released, with the valve body being seated on the valve seat, and the valve guide being situated at a non-contact position spaced away from the valve seat.

First claim

The invention claimed is:

1. A flow rate control valve comprising:
a valve casing forming a fluid passage;
a valve seat provided in the fluid passage of the valve casing;
an electric motor mounted on the valve casing and drive-controlled by a controller;
a valve guide stroke-controlled in an axial direction by the electric motor via a feed screw mechanism;
a valve body configured to be placed and separated on and from the valve seat;
a connector connecting the valve guide and the valve body so as to allow them to move in the axial direction within a predetermined range;
a biasing means configured to bias the valve body in a closing direction; and
a contact portion provided on the valve casing and configured to limit the movement in the closing direction of the valve guide through contacting the valve guide,
wherein when closing the valve body, the controller controls the electric motor to attain a closed state such that a connection between the valve guide and the valve body by the connector is released, with the valve body being seated on the valve seat, and the valve guide being situated at a non-contact position spaced away from the contact portion of the valve casing.

2. The flow rate control valve of claim 1 wherein, when closing the valve body, the controller controls the electric motor to perform a valve closing operation to thereby place the valve body on the valve seat, and then the valve guide is further moved in the closing direction, whereby the connection between the valve guide and the valve body through the connector is released and the valve closing operation of the electric motor is stopped before the valve guide comes into contact with the contact portion of the valve casing, thereby to attain the closed state.

3. The flow rate control valve of claim 1 wherein, when closing the valve body, the controller controls the electric motor to perform a valve closing operation to thereby place the valve body on the valve seat, and then the valve guide is further moved in the closing direction, whereby the connection between the valve guide and the valve body through the connector is released, further the controller controls the electric motor to perform a valve opening operation after the valve guide contacts the contact portion of the valve casing to thereby place the valve guide at a position spaced away from the contact portion of the valve casing, and then the valve opening operation of the electric motor is stopped, thereby to attain the closed state.

4. The flow rate control valve of claim 1 wherein the connector includes a connection protrusion provided on one of the valve guide and the valve body and a connection recess provided on the other and configured to be engaged with the connection protrusion so as to allow movement in the axial direction within the predetermined range.

5. The flow rate control valve of claim 4 wherein:
the connection recess includes an opening configured to allow the connection protrusion to get in and out through relative displacement around an axis while the valve body is moved in an opening direction with respect to the valve guide; and
the opening of the connection recess and the connection protrusion are arranged in a positional relationship in which they are not aligned in an opening and closing operation.

6. The flow rate control valve of claim 5 wherein the valve body includes a tool engagement portion configured to be detachably engaged with a tool for rotating the valve body.

7. The flow rate control valve of claim 4 wherein:
the valve guide includes a tubular tube wall portion;
the valve body includes a tube wall portion to be fit-engaged with the tube wall portion of the valve guide;
the connector is provided between the tube wall portion of the valve guide and the tube wall portion of the valve body;
the connection protrusion protrudes radially outwards from the tube wall portion of the valve body; and
the connection recess is open radially inwards on an inner peripheral side of the tube wall portion of the valve guide.

8. The flow rate control valve of claim 7 wherein:
the valve guide is divided into two so that the connection recess is opened in the axial direction; and
resultant two members are bonded together while accommodating the connection protrusion in the connection recess.

9. The flow rate control valve of claim 1 wherein the biasing means is an elastic member provided between the valve guide and the valve body.

10. The flow rate control valve of claim 9 wherein the elastic member is a coil spring arranged concentrically with respect to the valve guide and the valve body.

11. The flow rate control valve of claim 10 wherein:
the valve body includes a tubular tube wall portion arranged on an outer peripheral side of the coil spring; and
the valve guide includes a wall portion to be fit-engaged with an outer peripheral side of the tube wall portion of the valve body.

12. A fuel vapor processing apparatus comprising:
a canister capable of adsorbing and desorbing vapor generated in a fuel tank of a vehicle with an internal combustion engine mounted therein;
a vapor passage configured to allow fluid communication between the fuel tank and the canister;
a purge passage configured to allow fluid communication between the canister and an intake passage of the internal combustion engine;
a purge valve capable of opening and closing the purge passage;
a closing valve capable of opening and closing the vapor passage;
a controller configured to control the purge valve and the closing valve, and a flow rate control vale according to claim 1 as the closing valve.

Assignees

• Aisan Ind

Inventors

• Kimoto Junya
• Murai Shinji

Classifications

• F16K17/048

  combined with other safety valves, or with pressure control devices · CPC title

• F16K31/047

  characterised by mechanical means between the motor and the valve, e.g. lost motion means reducing backlash, clutches, brakes or return means (F16K31/043 takes precedence) · CPC title

• F02M25/0854

  Details of the absorption canister · CPC title

• F16K31/508

  the actuating element being rotatable, non-rising, and driving a non-rotatable axially-sliding element · CPC title

• F02M37/00

  Apparatus or systems for feeding liquid fuel from storage containers to carburettors or fuel-injection apparatus; Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines · CPC title