WO2007074950A1

WO2007074950A1 - Pressure regulator for fuel system of vehicles

Info

Publication number: WO2007074950A1
Application number: PCT/KR2005/004565
Authority: WO
Inventors: Taehee Lee; Seokyoon Chang; Junwoo Kim; Teahyung Kim
Original assignee: Inzi Controls Co., Ltd.
Priority date: 2005-12-27
Filing date: 2005-12-27
Publication date: 2007-07-05

Abstract

A pressure regulator connected between a fuel return tube and a fuel tank of a vehicle to control pressure of a fuel system by operating in response to pressure of fuel includes a housing having a fuel inlet portion and a fuel outlet portion that are respectively connected to the fuel return tube and the fuel tank to exhaust and introduce the fuel and a fuel storage chamber for storing the fuel introduced through the fuel inlet portion, an opening/closing member for closing a passage of the fuel inlet portion by seating on the fuel inlet portion and opening the passage of the fuel inlet portion by pressure of the fuel introduced from the fuel return tube to the fuel inlet portion, a plate having an inclined arm inclined toward the opening/closing member to elastically support the opening/closing member and having first and second end portions respectively fixed and supported on first and second sides of the housing, and fixing and supporting means for respectively fixing and supporting the first and second end portions on the first and second sides of the housing.

Description

[DESCRIPTION]

[invention Title]

PBESSUPE REGULATOR FOR FUEL SYSTEM OF VEHICLES [Technical Field]

The present invention relates to a pressure regulator for a fuel system of a vehicle, and more particularly, to a pressure regulator connected between a fuel return tube and a fuel tank to regulate pressure of a fuel system. [Background Art]

Generally, a pressure regulator for a fuel system of a vehicle is connected at its first end to a fuel return tube and at its second end to a fuel tank. The pressure regulator returns fuel to the fuel tank only when pressure of the fuel is above a predetermined level so that a hydraulic pressure line of the fuel system can uniformly maintain a predetermined pressure.

A diaphragm type valve having a coil spring and an elastic thin film formed of rubber is generally used as the pressure regulator. However, in the conventional pressure regulator, the coil spring is easily buckled due to its length and is unstably seated since both end portions of the coil spring is deformed by pressure applied by the inflow fuel. Therefore, the conventional pressure regulator cannot precisely regulate the pressure due to the problems caused by the coil spring. In addition, with the conventional pressure regulator, since the elastic thin film is activated by only relatively high pressure, the operation for closing and opening a fluid passage is not effectively realized. Furthermore, the pressure for the elastic thin film cannot be flexibly regulated.

Furthermore, as the elastic thin film is formed of the rubber, it has a poor heat-resistance.

Korean unexamined patent No. 2003-83463 on October 30, 2003 discloses a pressure regulator that is developed to solve the problems of the conventional pressure regulator. FIG. 1 shows the pressure regulator of the patent.

Referring to FIG. 1, when fuel is introduced through a fuel inlet 12, a ball member B opens a fuel inlet 12 so that the introduced fuel can be exhausted through a fuel outlet 14 via a fuel reserving portion 16. At this point, the ball member B opens the fuel inlet 12 while overcoming an elastic force of a leaf spring pressurized by a joint shaft 20. When the pressure of the fuel being introduced is lowered, the ball member B blocks the fuel inlet 12 by the elastic force of the leaf spring 20. Therefore, a fuel supply line (not shown) toward the fuel inlet 12 can maintain a predetermined pressure.

In the pressure regulator, opposite ends of the leaf spring 20 are respectively supported on a housing 1 having upper and lower housings Ia and Ib and the ball member B. At this point, as shown in FIG. 1, one end of the leaf spring 20 is supported on a side of the housing 1 by an elastic adjusting bolt 30. In addition, as the leaf spring 20 is bent about the joint shaft 20 and maintains the bent state. However, in order to assemble the pressure regulator, after the ball member B seats on a valve seat of the fuel inlet 12, the leaf spring 20 must be installed in the housing after being forcedly bent. This is troublesome for a worker. Particularly, since the leaf spring 20 must be bent and positioned around the joint shaft 20 and one end of the leaf spring 20 bent about the joint shaft 20 must be supported on the elastic adjusting bold 30, the assembling property is deteriorated.

In addition, in order to maintain the bent state of the leaf spring 20, the joint shaft 20 must be provided.

Furthermore, since the elastic adjusting bolt 30 penetrates the housing 1, the fuel reserved in the fuel reserving portion 16 defined in the housing 1 may leak through a coupling portion of the elastic adjusting bolt 30. [Disclosure] [Technical Problem]

An object of the present invention is to provide a pressure regulator for a fuel system of a vehicle, in which a bent leaf spring is used so that there is no need to forcedly bent the leaf spring by a worker, the leaf spring is fixed at its one end to a housing so that the leaf spring can be lifted in the housing even when a joint shaft is omitted, and the elastic force can be adjusted while the leak of the fuel out of thee housing is prevented.

[Technical Solution] To achieve the above object, the present invention provides a pressure regulator connected between a fuel return tube and a fuel tank of a vehicle to control pressure of a fuel system by operating in response to pressure of fuel, the pressure regulator including: a housing 50 having a fuel inlet portion 52 and a fuel outlet portion 54 that are respectively connected to the fuel return tube and the fuel tank to exhaust and introduce the fuel and a fuel storage chamber 56 for storing the fuel introduced through the fuel inlet portion 52; an opening/closing member 60 for closing a passage of the fuel inlet portion 52 by seating on the fuel inlet portion 52 and opening the passage of the fuel inlet portion 52 by pressure of the fuel introduced from the fuel return tube to the fuel inlet portion 52; a plate 70 having an inclined arm 72 inclined toward the opening/closing member 60 to elastically support the opening/closing member 60 and having first and second end portions 70a and 70b respectively fixed and supported on first and second sides of the housing 50; and fixing and supporting means for respectively fixing and supporting the first and second end portions 70a and 70b on the first and second sides of the housing 50. [Description of Drawings]

FIG. 1 is a longitudinal sectional view of a conventional pressure regulator for a fuel system of a vehicle; FIG. 2 an exploded perspective view of a pressure regulator according to an embodiment of the present invention;

FIG. 3 is a longitudinal sectional view of the pressure regulator of FIG. 2; FIG. 4 is a graph illustrating a pressure property of the pressure regulator of FIG. 2; and

FIG. 5 is a longitudinal sectional view a modified example of a housing of FIG. 2.

[Best Mode]

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to accompanying drawings. FIG. 2 an exploded perspective view of a pressure regulator according to an embodiment of the present invention, FIG. 3 is a longitudinal sectional view of the pressure regulator of FIG. 2, FIG. 4 is a graph illustrating a pressure property of the pressure regulator of FIG. 2.

Referring to FIG. 2, a pressure regulator of this embodiment includes a housing 50 in which a leaf spring 70 is installed. The housing 50 includes a metal container body 50a and a cap 50b. The body 50a defines a fuel storage chamber 56 for storing fuel. A tube-shaped fuel inlet member 52 around which a packing P is fitted is directly connected to the body 50a. Alternately, the fuel inlet member 52 may be integrally formed with the body 50a. The cap 50b is provided with a fuel outlet 54 through which the fuel stored in the fuel storage chamber 56 is exhausted. The fuel outlet 54 may be preferably formed by through holes formed on side portions of the cap 50b. The cap 50b and the body 50a are integrally coupled to each other. At this point, the fuel inlet member 52 communicates with a fuel return tube (not shown) while the fuel outlet 54 communicates with a fuel tank (not shown) . Therefore, the fuel in the fuel return tube is supplied to the fuel tank via the housing 50 having the body 50a and the cap 50b.

An opening/closing member 60 is installed in the body 50a of the housing 50 to open and close a passage of the fuel inlet member 52. The opening/closing member 60 may be formed of a ball member as shown in FIG. 2. Alternatively, the opening/closing member 60 may be formed of a cone-shaped bar. In this case, a pointed end of the cone-shaped bar is inserted in the passage of the fuel inlet member 52. At this point, an opposite end to the pointed end of the cone-shaped bar has a diameter greater that that of the passage of the fuel inlet member 52 so that the cone-shaped bar can be placed on the fuel inlet member 52. The metal plate 70 is installed in the body 50a of the housing 50. The plate 70 functions as a spring by a thickness and a material property. First and second ends of the plate 70 are respectively fixed and supported on fixing and supporting means.

The fixing means includes through holes 74 formed on a first end portion 70a of the plate and bendable projections 58a integrally extending from a first side of the housing and inserted into the through holes 74. As shown in the drawing, the through holes are formed at both sides of the first end portion 70a of the plate 70.

The supporting means^' includes a fitting hole 58b formed on a second side of the housing 50. A second end portion 70b of the plate 70 is fitted in the fitting hole 58b. At this point, it is preferable that both sides of the second end portion 70b of the plate 70 are cut away so that a middle portion of the second end ^• portion 70b protrudes. Therefore, the plate 70 is supported by the protruding middle portion of the second end portion 70b fitted in the fitting hole 58b. The fixing and supporting means will be described in more detail later.

The plate 70 has an inclined arm 72. The inclined arm 72 is integrally formed with the plate 70. As shown in the drawing, the inclined arm 72 may be formed by cutting a portion of the plate 70. In order to prevent the strength of the plate from being deteriorated, it is preferable that the inclined arm 72 is formed by cutting a central portion of the plate 70.

As shown in the drawing, the inclined arm 72 is bent from the plate 70. That is, the inclined arm 72 has a connecting portion 72a connected to the plate 70 and a contacting portion 72b extending from the connecting portion

72a.

Referring to FIG. 3, the housing 50 is sealed by the body 50a and the cap 50b that are coupled to each other. Therefore, the fuel storage chamber 56 defined in the body

50a is isolated from the external side.

The opening/closing member 60 is placed on an end portion of the passage of the fuel inlet member 52 to selectively open and close the passage. The fuel inlet member 52 has a seat 52 on which the opening/closing member

60 can stably seat. The opening/closing member 60 seats on the seat 52a.

As shown in the drawing, the plate 70 has the first end portion 70a that is fixed by the through holes 74 and the projections 58a of the body 50a. That is, the first end portion 70a of the plate 70 is fixed on the first side of the housing 50. At this point, the linear projection 58a is inserted and then bent to clamp the plate 70. Thus, the first end portion 70a of the plate 70 becomes the fixed end. In addition, the second end portion 70b is inserted in the fitting hole 58b formed on the second side of the body 50a. Therefore, the second end portion 70b of the plate 70 becomes a free end that can move only within a space defined by the fitting hole 58b.

As shown in an enlarge view of FIG. 3, the inclined arm 72 integrally formed with the plate 70 has a first end that is bent downward and a second end portion contacting the opening/closing member 60 to elastically support the opening/closing member 60. At this point, a portion of the inclined arm 72, which contacts the opening/closing member 60, is the contacting portion 72b of the inclined arm 72. That is, the contacting portion 72b contacts the opening/closing member 60.

As the first end of the inclined arm 72 is bent downward at the plate 70 to form an bent angle θ between the plate 70 and the connecting portion 72a. The bent angle θ is less than an obtuse angle, preferably, within a range of 120- 170°, more preferably, 160°.

The inclined arm 72 has another bent portion between the opposite ends thereof so that the contacting portion 72a can maintain the horizontal level on the opening/closing member 60. It is preferable that the bent portion is formed at a boundary portion between the connecting portion 72a and the contacting portion 72a. At this point, the bent angle α between the connecting portion 72a and the contacting portion 72a is less than an obtuse angle, preferably, within a range of 120-170°, more preferably, 150°. That is, the bent angle α may be an alternate angle of the bent angle θ.

By the bent angle α, the contacting portion 72a of the inclined arm 72 contacts the opening/closing member 60 while maintaining a horizontal level relative to a vertical axis Y of the opening/closing member 60. Therefore, the contacting portion 72a stably maintains the contacting state with the opening/closing member 60.

Meanwhile, the plate 70 is curved with a curvature toward the inclined arm 72. By the curvature of the plate 70, the inclined arm 72 supporting the opening/closing member 60 is pressed to bias the inclined arm 72. Therefore, the inclined arm 72 is enhanced in its elastic force.

The reference number 59 of FIG. 2 indicates a ground terminal integrally extending from the housing 50 and connected to a ground portion (not shown) of a fuel pump provided on the fuel tank (not shown) . The ground terminal 59 is connected to the ground portion by a wire. The ground terminal 59 discharges a leakage current such as static electricity generated from the housing 50. Particularly, the ground terminal 59 discharges the leakage current generated from the fuel pump. Therefore, the fuel system including the housing 50 can be protected from the leakage current.

The operation of the above-described pressure regulator of this embodiment will now be described with reference to FIG. 3. The ball type opening/closing member

60 is exampled in the following description.

Fuel in the fuel return tube (not shown) is introduced through the fuel inlet member 52. At this point, the opening/closing member 60 elastically supported by the inclined arm 72 of the plate 70 is lifted when the pressure of the fuel being introduced is greater than the elastic force of the inclined arm 72 and thus the passage of the fuel inlet member 52 is opened. Therefore, the fuel is introduced through the fuel inlet member 52 and stored in the fuel storage chamber 56. Then, the stored fuel is supplied to the fuel tank (not shown) through the fuel outlet 54.

When the pressure of the fuel being introduced is less than the elastic force of the inclined arm 72, the ball type opening/closing member 60 seats on the seat 52a by the elastic force of the inclined arm 72, thereby closing the passage of the fuel inlet member 52.

At this point, the inclined arm 72 transmits the elastic force generated by the bent angle θ to the opening/closing member 60 and thus the contacting portion 72b of the inclined arm 72 presses the opening/closing member 60 while stably supporting the opening/closing member 60 by the bent angle α.

Referring to FIG. 4, the pressure regulator of this embodiment provides a stable pressure property with respect to a flow rate to the fuel system. That is, the pressure regulator of this embodiment has a pressure property that is not steeply varied but gently varied with respect to the flow rate. Therefore, the pressure regulator provides a stable pressure property that is proportional to the flow rate to the fuel system.

FIG. 5 is a longitudinal sectional view a modified example of the housing of FIG. 2. In this modified example, the second side of the housing 50, on which the second end portion 70b of the plate 70 is supported, is modified. Referring to FIG. 5, when the second side of the body 50a, on which the second end portion 70b of the plate 70 is supported, is curved inward, the plate 70 is deformed from a state depicted by a broken line to a state depicted by a solid line. Therefore, the elastic force of the inclined arm 70 integrally formed with the plate 70 is enhanced as the curvature of the plate 70 increases. That is, in order to enhance the elastic force of the inclined arm 70, the second side of the housing 50 is curved inward to increase the curvature of the plate 70. That is, by allowing the second side of the housing 50 to be curved inward, the elastic force of the inclined arm 70 can be adjusted.

While the present invention has been described and illustrated herein with reference to the preferred embodiments thereof, it will be apparent to those skilled in the art that various modifications and variations can be made therein without departing from the spirit and scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention that come within the scope of the appended claims and their equivalents . [industrial Applicability]

According to the pressure regulator of the fuel system of the vehicle of the present invention, unlike the conventional pressure regulator that is a diaphragm type using a spring and a thin rubber film, the inventive pressure regulator does not use the spring and the thin rubber film. Therefore, the pressure can be more precisely controlled to stably apply the pressure to the fuel system and the dispersion of the pressure control can be reduced.

In addition, since no thin rubber film is used, the endurance against the heat-impact and the fatigue can be improved.

Furthermore, since the inclined arm of the plate functioning as the leaf spring is installed in a state where it is bent and the one end of the plate is fixed by the fixing means, the joint shaft that has been used in the prior art can be omitted and the assembling process can be simplified.

In addition, the elastic force of the inclined arm integrally formed on the plate is adjusted by bending a sidewall of the housing, the elastic control bolt that has been used in the prior art to adjust the elastic force of the leaf spring can be omitted and the leakage of the fuel from the housing can be prevented.

Claims

[CLAIMS]

[Claim l]

A pressure regulator connected between a fuel return tube and a fuel tank of a vehicle to control pressure of a fuel system by operating in response to pressure of fuel, the pressure regulator comprising: a housing having a fuel inlet portion and a fuel outlet portion that are respectively connected to the fuel return tube and the fuel tank to exhaust and introduce the fuel and a fuel storage chamber for storing the fuel introduced through the fuel inlet portion ; an opening/closing member for closing a passage of the fuel inlet portion by seating on the fuel inlet portion and opening the passage of the fuel inlet portion by pressure of the fuel introduced from the fuel return tube to the fuel inlet portion ; a plate having an inclined arm inclined toward the opening/closing member to elastically support the opening/closing member and having first and second end portions respectively fixed and supported on first and second sides of the housing ; and fixing and supporting means for respectively fixing and supporting the first and second end portions on the first and second sides of the housing.

[Claim 2]

The pressure regulator of claim 1, wherein the inclined arm is formed by cutting a portion of the plate so that it can be integrally formed with the plate.

[Claim 3]

The pressure regulator of claim 1, wherein the inclined arm is bent at one or more portions between opposite ends thereof such that the inclined arm contacts the opening/closing member while maintaining a horizontal level relative to a vertical axis Y of the opening/closing member.

[Claim 4]

The pressure regulator of claim 1, wherein the fixing means includes through holes formed on a first end portion of the plate and bendable projections integrally extending from a first side of the housing and inserted into the through holes, thereby suppressing the movement of the plate.

[Claim 5]

The pressure regulator of claim 1, wherein the supporting means includes a fitting hole formed on a second side of the housing and a second end portion of the plate supportably fitted in the fitting hole.

[Claim 6]

The pressure regulator of claim 1, wherein the housing further includes a discharge member for discharging abnormal currents such as static electricity or leakage current, the discharge member including a ground terminal integrally protruding from the housing and ground-contacts the ground portion of the fuel tank.

[Claim 7]

The pressure regulator of any one of claims 1 through 6, further comprising means for enhancing elastic force of the inclined arm of the plate, the means for enhancing is formed by a curvature of the plate toward the inclined arm so that the plate presses the inclined arm supporting the opening/closing member.