Check valve

Patent metadata

Field	Value
Publication number	US-10295074-B2
Application number	US-201615352170-A
Country	US
Kind code	B2
Filing date	Nov 15, 2016
Priority date	Nov 18, 2015
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A check valve includes a valve case, a positive pressure valve, a spring, and a negative pressure valve. The positive pressure valve is slidably disposed in a valve chamber of the valve case. The spring urges the positive pressure valve to abut on a positive pressure valve seat of the valve case. The negative pressure valve is on the positive pressure valve to abut on a negative pressure valve seat of the positive pressure valve. The negative pressure valve closes a communicating passage in the positive pressure valve in a normal state, and opens it when a pressure in the fuel tank falls to a predetermined value or less.

First claim

The invention claimed is:

1. A check valve mounted on a fuel tank of an automobile, the check valve comprising:
a valve case comprising:
a first connecting portion connected with a pipe which is to be communicated with the fuel tank;
a second connecting portion connected with a pipe which is to be communicated with a canister disposed outside the fuel tank;
a valve chamber formed inside the valve case; and
a positive pressure valve seat provided in a portion ranging from the valve chamber to the first connecting portion;

a positive pressure valve slidably disposed in the valve chamber to abut on and separate from the positive pressure valve seat; and
a spring disposed in the valve case configured to urge to make the positive pressure valve abut on the positive pressure valve seat, and to be compressed to thereby open the positive pressure valve when a pressure in the fuel tank rises to a predetermined value or more,
wherein the positive pressure valve comprises:
a valve main body;
an annular sealing member made from an elastic resin material, and mounted on the valve main body so as to abut on and separate from the positive pressure valve seat; and
a retainer mounted on the valve main body so as to sandwich the annular sealing member with the valve main body,

wherein the valve main body comprises:
a placing face on which the annular sealing member is placed,

wherein the retainer comprises:
a communicating passage disposed on an inside diameter side of the annular sealing member;
a sandwiching portion formed to sandwich the annular sealing member with the placing face of the valve main body; and
a negative pressure valve seat which communicates with the communicating passage,

wherein the check valve further comprises a negative pressure valve made from an elastic resin material, and mounted on the retainer so as to abut on and separate from the negative pressure valve seat, such that the negative pressure valve closes the communicating passage in a normal state by abutting on the negative pressure valve seat, and opens the communicating passage when the pressure in the fuel tank falls to a predetermined value or less,
wherein the retainer includes a cylindrical portion,
wherein the sandwiching portion includes a portion having a flange shape which extends radially outward from an outer circumference of the cylindrical portion, and
wherein the negative pressure valve seat is formed in the portion of the sandwiching portion having the flange shape.

2. The check valve according to claim 1 ,
wherein the negative pressure valve comprises a flange portion having a circular shape, and
wherein the flange portion has an outside diameter larger than an inside diameter of the annular sealing member and smaller than an outside diameter of the annular sealing member in a state where an axial center of the valve main body, a center of the annular sealing member and a center of the flange portion of the negative pressure valve are aligned.

3. The check valve according to claim 1 ,
wherein the valve main body comprises a retainer fitting portion disposed at a position corresponding to an inside diameter side of the annular sealing member being placed on the placing face, and configured to fit the retainer.

4. The check valve according to claim 3 ,
wherein the negative pressure valve comprises a flange portion having a circular shape, and a shaft portion extending from a center on a back surface of the flange portion, and
wherein the retainer comprises a negative pressure valve-fitting portion into which the shaft portion of the negative pressure valve fits, the negative pressure valve-fitting portion being disposed on an inner side of a portion of the retainer so as to fit the retainer fitting portion.

5. The check valve according to claim 1 , wherein the valve main body further comprises an abutting protrusion that separates the annular sealing member from the valve main body, and
wherein the abutting protrusion causes the annular sealing member to separate from the placing face with a predetermined space when the positive pressure valve slides against the urging force of the spring and the positive pressure valve seat opens.

6. The check valve according to claim 1 , wherein the negative pressure valve seat and the sandwiching portion form a single member.

7. The check valve according to claim 1 , wherein the annular sealing member comprises:
a first portion; and
a second portion having a thickness less than a thickness of the first portion.

8. The check valve according to claim 7 , wherein the first portion has an annular shape on an inner side, and
wherein the second portion has a flange shape having a thickness less than the thickness of the first portion and extends in a radial outer direction from a rim of the first portion.

9. The check valve according to claim 7 , wherein the sandwiching portion has an outside diameter greater than an outside diameter of the first portion of the annular sealing member, and is disposed so as to reach a top surface of the second portion beyond the outside diameter of the first portion when the first portion is sandwiched between the sandwiching portion and the placing face of the valve main body.

10. The check valve according to claim 1 , wherein the valve main body further comprises a supporting protrusion having an annular shape that protrudes from a rim on a top side of a through-hole of the valve main body, and
wherein the supporting protrusion sandwiches the annular sealing member between the sandwiching portion of the retainer and the placing face in a state where the annular sealing member is placed on the placing face.

11. The check valve according to claim 1 , wherein the sandwiching portion has an outside diameter greater than an outside diameter of a first portion of the annular sealing member, and is disposed so as to reach a top surface of a second portion of the annular sealing member beyond the outside diameter of the first portion when the first portion is sandwiched between the sandwiching portion and the placing face of the valve main body.

Assignees

• Piolax Inc

Inventors

• Yamaguchi Kosei

Classifications

• F16K15/025 Primary

  the valve being loaded by a spring (F16K15/03 - F16K15/12 take precedence) · CPC title

• F16K17/196 Primary

  spring-loaded · CPC title

• B60K15/03519 Primary

  Valve arrangements in the vent line · CPC title

• Y10T137/7773

  Supporting valve only spring biased · CPC title

• F16K15/148

  the closure elements being fixed in their centre · CPC title