JPH0648213Y2 - Valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a valve body used in a valve cap such as a fuel cap of an automobile.

<Prior Art> In the valve element used in the conventional fuel cap,
There is one shown in FIG. 9 (see JP-A-60-116974).

The valve body 7 is formed of a rubber-like elastic material such as rubber or a thermoplastic elastomer into a substantially disc shape, and the valve body holding plate 6 as a holding member for the valve body 7 is attached to the lower central portion so as to be mounted downward. A protrusion 7c having a bulged tip is formed so as to be assembled in the hole 6a.

In addition, a lip part protruding upward is provided on the entire outer peripheral edge of the upper surface.
7b had been formed. The lip portion 7b is provided on the periphery of the passage hole 2b with the lower surface of the periphery of the passage hole 2b formed at the center of the top plate portion 2a of the cap body 2 facing the valve body holding plate 6 as a sealing portion. It was pressed by the biasing force of the coil spring 5. The lower end of the coil spring 5 is held by a spring holding plate 4 which is undercut near the lower portion of the inner peripheral surface of the cap body 2, and the upper end of the coil spring 5 is brought into contact with the lower surface of the valve holding plate 6 to hold the valve holding plate 6. The valve body 7
Along with it, it is urged upward.

Further, the peripheral portion of the valve body 7 is formed thin so that the lower side is cut away, and when the valve body 7 is assembled to the valve body holding plate 6, a gap is formed between the valve body 7 and the valve body holding plate 6. Was provided, and the thin portion thereof was configured to bend in the axial direction of the valve body 7 with the connecting portion with the thick portion near the center as a fulcrum.

Reference numeral 3 is an upper lid fitted on the upper portion of the cap body 2, and 10 is a fuel tank filler.

When the fuel cap 1 is in use, when the inside of the fuel tank is in a negative pressure state above a predetermined level, the valve body 7 is lowered together with the valve body holding plate 6 against the biasing force of the coil spring 5. Since the lip portion 7b is separated from the lower surface of the peripheral edge of the flow passage hole 2b of the cap body top plate portion 2a to open the flow passage hole 2b, air flows into the fuel tank through the flow passage hole 2b, and the fuel tank It was to eliminate the negative pressure inside.

<Problems to be Solved by the Invention> In the conventional valve body 7, an annular lip portion is provided on the entire outer peripheral edge of the upper surface.
Since the 7b is formed so as to project, the portion where the rip portion 7b is formed is naturally thicker than the portion continuous with the rip portion 7b.

When molding a valve body 7 of this type, for example, when a gate is provided below the central protrusion 7c, the rubber-like elastic material moves from the holding portion 7a to the lip portion 7b in the mold cavity. Since it flows to the molded part, the lip part 7b
Is thick, the filling pressure of the rubber-like elastic material is
It suddenly dropped, and there was a risk of air trapping. When air is trapped, the lip part is pressed against the seal area from the viewpoint of valve opening sensitivity and seal characteristics.
7b The surface accuracy (smoothness, about ± 5 μm) required for the top 7h was not secured, resulting in a defective product.

This invention solves the above-mentioned problems, prevents air from forming in the rip portion during molding of the valve body, makes it easy to obtain the surface accuracy required at the top of the rip portion, and reduces the incidence of defective products. An object is to provide a valve body that can be reduced.

<Means for Solving Problems> A valve body according to the present invention is held by a holding member, is made of a rubber-like elastic material, and is provided on a top surface or a bottom surface so as to project in a substantially annular shape, and a top portion thereof has a predetermined sealing portion. In the valve body having a lip portion that is pressed into contact with the lip portion, by forming an annular lightening portion at a position within the annular width where the lip portion is formed, on the lower surface or the upper surface that is the top back surface side of the lip portion, It solves the problem described above.

<Operation and Effect of Invention> In the valve body according to the invention, an annular lightening portion is formed at a position within the annular width where the lip portion is formed on the lower surface or the upper surface which is the top back surface side of the annular lip portion. Thus, the thickness of the lip portion is thinner than that of the conventional one.

Therefore, when molding the valve body, the filling pressure of the rubber-like elastic material filled in the mold cavity does not drop sharply at the rip portion, so it is possible to prevent air accumulation in the rip portion. can do. Then, the surface accuracy required for the top of the lip portion is easily obtained, and the occurrence rate of defective valve bodies can be reduced.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. The same members as those of the related art are designated by the same reference numerals.

The valve body 17 of the first embodiment shown in FIGS. 1 and 2 is disposed in the fuel cap 11 similar to the conventional one, and is formed in a substantially disc shape from a rubber-like elastic material such as rubber or thermoplastic elastomer. In addition, a protrusion 17c similar to the conventional one is provided at the lower center portion.

An annular lip portion 17b protruding upward is formed on the entire outer peripheral edge of the upper surface of the valve body 17. This lip 17b
Has a substantially triangular shape and its top 17h is pressed against the lower surface of the peripheral edge of the flow path hole 2b in the cap body top plate 2a, which is a sealing portion. Also, on the lower surface corresponding to the back surface of the top portion 17h, a position within the annular width where the lip portion 17b is formed, that is, just below the top portion 17h, a shape (substantially triangular) substantially similar to the shape of the lip portion 17b is formed. The lightening portion 17d is formed. The lightening portion 17d of the first embodiment has a size such that the thickness of the lip portion 17b is substantially the same as the thickness of the portion continuous with the lip portion 17b. Therefore, when the valve body 17 of the first embodiment is molded in the same manner as in the prior art, the filling pressure of the rubber-like elastic material filled in the mold cavity is kept substantially constant without abruptly decreasing. Therefore, the lip part
It is possible to prevent the accumulation of air in 17b.
From the standpoint of valve opening sensitivity and sealing characteristics, the lip portion 17
b The surface accuracy (smoothness, about ± 5 μm) required for the top portion 17h is easily obtained, the incidence of defective products of the valve body 17 can be reduced, and the product cost can be reduced. .

A thin portion is formed on the peripheral edge of the valve body 17 as in the conventional case. Further, a concave portion 17f is formed on the entire upper surface of the valve body 17 in the vicinity of the lip portion 17b, and that portion serves as a bending fulcrum of the lip portion 17b.

Then, the valve body 17 is assembled and held on the valve body holding plate 6 which is a holding member via the projection 17c, and is assembled in the cap body 2 together with the coil spring 5 and the spring holding plate 4, and the fuel cap 11 is used as a fuel. Tank filler 10
When the valve body 17 is normally used after being tightened, the lip portion 17b is pressed against the lower surface of the peripheral edge of the flow passage hole 2b in the cap body top plate portion 2a, which is the sealing portion, by the biasing force of the coil spring 5. The flow path hole 2b is closed. At this time, the lip portion 17b has two bending fulcrums, that is, a connecting portion between a thin portion at the peripheral portion of the valve body 17 and a thick portion at the center and a portion on the upper surface of the valve body 17 where the recess 17f is formed. Therefore, it is possible to absorb an error in the undulation accuracy of the cap body top plate portion 2a, which is the sealing portion of the lip portion 17b, and facilitate the accuracy control of the top plate portion 2a.

By the way, when the inside of the fuel tank is in a negative pressure state above a predetermined level, the valve body 17 is lowered together with the valve body holding plate 6 against the negative force of the coil spring 5, and the flow path of the cap body top plate portion 2a is lowered. The lip portion 17b is separated from the lower surface of the peripheral edge of the hole 2b, and the flow path hole 2b
Since the air is opened, the air flows into the fuel tank through the flow path hole 2b to eliminate the negative pressure state in the fuel tank.

Further, in the first embodiment, the valve element 17 that operates at the time of negative pressure has been described. However, as in the second embodiment shown in FIGS. 3 and 4, the valve element 27 that operates at the time of positive pressure and negative pressure can be used. May be applied.

The valve body 27 of the second embodiment is formed of a material similar to that of the valve body 17 of the first embodiment in a substantially disc shape, has a flow passage hole 27g in the center, and a valve body holding plate whose upper surface is a holding member. 26 It is attached to the lower surface and held.

An annular outer peripheral lip portion 27b and an inner peripheral lip portion 27c projecting downward are formed on the outer peripheral edge and the inner peripheral edge around the lower surface of the valve body 27, respectively. Outer and inner peripheral lip parts 27b ・ 2
7c is a projecting substantially triangular shape, the site where the outer peripheral lip portion 27b seals is a step portion 22a projecting on the inner peripheral surface of the cap body 22, and the portion where the inner peripheral lip portion 27c seals is
The valve plate 28 is biased upward from a spring seat 22b below the step portion 22a via a coil spring 25B. Further, on the upper surface of the valve body 27, which is the rear surface side of the tops 27h and 27i of the outer and inner lip parts 27b and 27c, the position within the annular width where the outer and inner lip parts 27b and 27c are formed, that is, Top 27h / 27i
Immediately above the outer peripheral lip portion 27b and the inner peripheral lip portion 27c, the thickness of the outer peripheral lip portion 27c is substantially semicircular so that the outer peripheral lip portion 27c and the inner peripheral lip portion 27c have substantially the same thickness as the portions continuous with the respective lip portions 27b and 27c.・
Since each of the inner peripheral lightening portions 27e is formed, the first
The same effect as that of the embodiment is obtained.

By the way, the operation mode of the fuel cap 21 at the time of positive pressure and negative pressure will be described.When the pressure inside the fuel tank is positive, the valve body 27 and the valve body 27 are resisted against the biasing force of the coil spring 25A. The holding plate 26 rises, the outer peripheral lip portion 27b of the valve body 27 separates from the cap body step portion 22a, and a gap is created there, so that fluid such as air in the fuel tank can flow through the spring seat 22b. 22c, through the flow passage hole 29a of the spring seat plate 29, it flows out into the atmosphere from between the elastic finger 22e formed on the upper flange portion 22d of the cap body 22 and the upper lid 23 (see FIG. 6), The positive pressure state in the fuel tank is eliminated. In addition, this elastic finger 22e
Is for regulating the tightening torque of the fuel cap 21 in cooperation with a plurality of protrusions 23a provided on the lower surface of the upper lid 23.

If the fuel tank is under negative pressure, the coil spring 25
The valve plate 28 descends against the urging force of B, the inner peripheral lip portion 27c of the valve element 27 separates from the valve plate 28, and a gap is created there, so that a fluid such as air can be elastic finger 22e.
The negative pressure state in the fuel tank is eliminated from between the upper lid 23 and the upper cover 23 through the flow passage hole 29a of the spring seat plate 29 and the flow passage hole 26b of the valve body holding plate 26.

Next, the valve element 37 of the third embodiment shown in FIGS. 6 and 7 will be described.

The valve body 37 of the third embodiment is formed of a material similar to that of the valve body 17 of the first embodiment into a substantially umbrella shape, and the top plate portion of the cap body 32.
32a.

The valve body 37 is fitted and held in an assembly hole 32b formed in the center of the top plate portion 32a, which is a holding member, and a flow path hole 37g is provided in the center.

A lip portion 37b protruding downward (inward) is formed on the entire outer peripheral edge of the lower surface of the valve body 37. Lip part 37b
Is a valve plate 38 having a substantially hemispherical shape, which is protruded in a substantially triangular shape and a portion sealed by the lip portion 37b. The valve plate 38 is a top plate portion of the cap body 32 holding the valve body 37.
The coil spring 35 is disposed so as to face the portion 32a and be biased upward by the coil spring 35. The coil spring 35 is a cap body 32.
The lower end is held by a spring holding plate 34, which is undercut by a plurality of ribs 32c protruding from the inner circumference.

Further, on the upper surface of the valve body 37, which is the rear surface side of the top portion 37h of the lip portion 37b, at a position within the annular width where the lip portion 37b is formed, the wall thickness of the lip portion 37b is a portion continuous with the lip portion 37b. The semi-circular shaped cutout 37 so that the thickness is approximately the same.
Since the d is formed, the same effect as that of the first embodiment can be obtained, and the valve element 37 may be configured in this way.

In the valve body 37 of the third embodiment, an annular concave portion 37f is formed on the upper surface in the vicinity of the lip portion 37b, and the lip portion 37b is easily bent by using that portion as a bending fulcrum. Therefore, the error of the undulation accuracy of the valve plate 38, which is the sealing portion of the lip portion 37b, can be absorbed, and the accuracy control of the valve plate 38 can be facilitated.

By the way, the operation mode of the fuel cap 31 of the third embodiment will be described. When the inside of the fuel tank becomes a negative pressure more than a predetermined value, the valve plate 38 is lowered against the urging force of the coil spring 35, and the valve body The valve plate 38 separates from the lip portion 37b of 37,
Since the flow passage hole 37g of the valve element 37 is opened, the negative pressure state in the fuel tank is eliminated via the flow passage hole 37g.

[Brief description of drawings]

1 is a sectional view showing a valve body of a first embodiment of the present invention, FIG. 2 is a sectional view of a fuel cap in which the valve body of the first embodiment is used, and FIG. 3 is a sectional view of a second embodiment. FIG. 4 is a sectional view of the fuel cap in which the valve body is used, FIG. 4 is a sectional view showing the valve body of the second embodiment, and FIG. 5 is a top view of the fuel cap in which the valve body of the second embodiment is used. Top view of detached state, No. 6
FIG. 7 is a sectional view of a fuel cap in which the valve body of the third embodiment is used, FIG. 7 is a sectional view of the valve body of the third embodiment, and FIG. 8 is a sectional view of a conventional valve body. FIG. 9 is a sectional view of a fuel cap in which a conventional valve body is used. 7 ・ 17 ・ 27 ・ 37 …… Valve disc, 7b ・ 17b ・ 27b ・ 27c ・ 37b …… Rip part, 17d ・ 27d ・ 27e ・ 37d …… Lightening part, 7h ・ 17h ・ 27h ・ 27i ・ 37h …… The top.

Continuation of the front page (72) Joji Kasugai Joji Kasugai, Kasuga-mura, Aichi, Japan 1 Ochiai, Nagahata, Ochiai, Toyoda Gosei Co., Ltd. (56) Reference: JP-A-60-116974 (JP, A) 96857 (JP, U) Actual public Sho 56-6688 (JP, Y2)

Claims (1)

[Scope of utility model registration request] 1. A valve body comprising a lip portion which is held by a holding member and is made of a rubber-like elastic material, and which has a substantially annular projection on an upper surface or a lower surface and whose top portion is pressed against a predetermined sealing portion. The valve body is characterized in that an annular lightening portion is formed at a position within the annular width where the lip portion is formed on the lower surface or the upper surface corresponding to the top rear surface of the portion.