Check valve

A check valve that can prevent sticking of a valve body and reliably perform an opening and closing action in a check vale having a simple structure and that does not use biasing means on the valve body. A check valve has support pieces of a valve body protruding in the valve body direction on a circular base seat forming an outflow window in the center inserted in a circular groove where a support member (retainer) is formed between an outflow opening and a valve seat and on an open edge of the outflow window formed in the center of the base seat, and the support pieces of the support member (retainer) that support the valve body have linear or planar support parts on the top portion for leveling at least in a radial direction of the base seat.

TECHNICAL FIELD

The present invention relates to a check valve used in a fuel passage of a carburetor for the purpose of, for example, preventing reverse flow of fuel.

BACKGROUND TECHNOLOGY

Check valves that allow fluid to flow out in only one direction and prevent the reverse flow have been known in the past, and various types such as a ball type, swing type, lift type, and disk type according to the structure of a valve have been known. A purpose of the check valve is to prevent the reverse flow of fluid, and since overall the body is not complicated, such as the disk type, it can be provided at a low cost, is easily installed in the middle of a tubular body, and therefore it is suitable for disposing, for example, in a fuel passage of a carburetor or the like.

Further, a disk type check valve forms an inflow opening and an outflow opening by a casing as described in, for example, Japanese Unexamined Patent Application Nos. H10-288265 and H07-101066, and a ring-shaped valve seat is formed there between to dispose a disk-shaped valve body having a larger diameter than the outflow opening and a smaller diameter than the valve seat, that is biased in the outflow opening direction by a coil spring. When the fluid flows in from the inflow opening at a pressure exceeding the biasing force of the coil spring, the valve body slides in the outflow opening direction by a large pressing force larger than the biasing force of the coil spring acting on the valve body so that the fluid that is coming in from the inflow opening through a gap which is formed on the outer periphery of the valve body in the valve seat, flows out. Conversely, when the fluid reverse flows from the outflow opening direction, the valve body slides in the inflow opening direction by the biasing force of the coil spring to close the inflow opening so as to prevent the reverse flow of the fluid.

A check valve using a further simple disk-shaped valve body described in Japanese Unexamined Patent Application No. 2010-60110 has also been known. This check valve, as illustrated inFIG. 5A, is configured such that a valve body332and a valve seat334are inserted to attach in a valve holder320, and assembled by engaging a projecting part324to a groove338of the valve body332. With this check valve330, as illustrated inFIG. 5B, the valve body332becomes an open state by abutting onto a valve stopper326made from a curved longitudinal beam member, and also becomes a close state by abutting the valve body332onto a valve seat336by reverse direction pressure.

Therefore, there is a large difference in the check valves described in Patent Application Nos. H10-288265 and H07-101066 in that an advantageous effect is exhibited with a simple structure without using means for pressing the valve body against the valve seat, for example, such as a coil spring.

Furthermore, a check valve illustrated inFIGS. 6A, 6B and 6Cis a conventionally known check valve having a further simpler configuration than the check valve that exhibits the similar advantageous effect with a simple structure without using biasing means illustrated inFIGS. 5A and 5B. It is configured such that a case body1is made of, for example, aluminum die cast, with a cylindrical inflow opening2and an outflow opening3formed respectively in both ends, as well as a cylindrical valve seat4, having a predetermined length, is formed in the axial direction between the inflow opening2and the outflow opening3, a disk-shaped valve body5with an outer diameter having a slightly smaller diameter than the inner diameter of the valve seat4as well as a larger diameter than the inner diameter of the inflow opening2, is disposed with an ability to move in the axial direction of the valve seat4, and a support member (retainer)6of the valve body5that is disposed between the outflow opening3of the valve seat4and the valve body5.

Moreover, the support member (retainer)6is configured as illustrated inFIGS. 7, 8A, 8B and 8Cwhere a disc-shaped base seat61that forms an outflow window62in the center that is fit into a circular circumferential groove formed between the outflow opening3and the valve seat4as illustrated inFIGS. 6A, 6B and 6C, and support pieces64of the valve body5illustrated inFIGS. 6A, 6B and 6Cthat are provided in an upwardly projecting manner (the valve body5direction) in an open edge63of the outlet window62formed in the center of the base61are projected as illustrated inFIGS. 7, 8A, 8B and 8C.

Also, in a check valve according to the present embodiment, as illustrated inFIG. 6A, a predetermined gap41is formed between the top surface43of the valve seat4because the valve body5disposed in the valve seat4is pressed in the outflow opening3direction by the fluid normally entering from the inflow opening2to be supported by the support pieces64of the support member (retainer)6.

Accordingly, the fluid entered from the inflow opening2flows towards the outflow opening3from the inflow window62of the support member (retainer)6via a space42formed between an inner peripheral surface44of the valve seat4and the support piece64from the gap41.

When the flow of the fluid changes in this condition, in other words, when the fluid that has been flowing toward the outflow opening3flows in reverse and flows in the direction of the inflow opening2, the open end21of the inflow opening2is closed by moving the valve body5in the axial direction within the valve seat4because the fluid that has been flowing toward the outflow opening3flows in reverse to operate the check valve. That is, as illustrated inFIG. 6B, the valve body5tightly contacts the open end21area of the inflow opening2of the valve seat4due to the fluid pressure of the reverse flow and the check valve becomes the close state.

Documents of the Related Art

Japanese Examined Patent Application No. H07-101066

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

However, the conventionally known support member (retainer)6is, for example, machine pressed in a metal circular plate of an appropriate thickness and formed with support pieces64for supporting the center of the outflow window62and the valve body5, and particularly, the tip ends of the support pieces64exhibit a horseshoe shape by bending the side surface upward, and as a result, the valve body5, when releasing, supports the valve body5in a point contact state by respective tip ends of each support piece64.

Accordingly, the valve body5is not supported by the support member (retainer)6in a stable state, and a protruding position of each support piece64on the support member (retainer)6is in a position separated from the inner circumferential surface44of the valve seat4. That is, because there is a large range of play in the valve body, when a fluid is applied to the valve body5at a pressure biased, for example, in a direction toward the outflow opening3with respect to the installation direction, then the valve body will tilt to an angle where one end of the valve5is deeply inserted into a space42positioned between the inner circumferential surface44of the valve seat4and each of the support pieces64as shown inFIG. 6C. Therefore, the valve body5gets stuck due to the 3 points of contact with the inner circumferential surface44of the valve seat4, each of the support pieces64, and the top portion43of the valve seat4, and as a result, there is a problem in that a state which inhibits the opening and closing action of the check valve is induced.

To resolve the above problem, an object of the present invention is to provide a check valve that can prevent sticking of a valve body and reliably perform an opening and closing action in a check vale having a simple structure and that does not use biasing means on the valve body as conventionally known.

Means for Solving the Problem

To resolve the above problems, the present invention is a check valve including: a case body in which a cylindrically shaped valve seat with a cylindrically shaped inflow opening and outlet opening formed respectively on each end and having an inner diameter larger than the inflow opening, and having a predetermined length in an axial direction formed between the inflow opening and the outlet opening; a disk shaped valve body having an outer diameter slightly smaller than the inner diameter of the valve seat and disposed with the ability to move in an axial direction of the valve seat by a larger diameter than the inner diameter of the outflow opening; a support member (retainer) of the valve body disposed between the valve body and the outlet opening of the valve seat; and a plurality of support pieces of the support member (retainer) protruded in the valve body direction on a disk shaped base seat are formed centrally on an open edge of an outflow window formed in the center of the base seat, where the support member (retainer) is inserted in a circular groove formed between the outflow opening and a valve seat; wherein each of the plurality of support pieces of the support member (retainer) supporting the valve body has a linear or planar support part on a top portion for leveling of the base seat at least in a radial direction.

Because each support piece of a support member (retainer) supporting a valve body has a linear or planar support part on the top portion for leveling at least in a radial direction of the base seat, the valve body, when in a released state, can be supported in a stable state to prevent the generation of chattering, can narrow the gap between the support part and the inner circumferential surface of the valve seat to reduce the space formed between the support piece, and can prevent sticking by the valve body by reducing the range of play in the valve body.

Further, in the present invention, when integrally forming the support member (retainer) from a plate member, each support piece forms a linear support part on the top portion for leveling at least in a radial direction of the base seat by raising the support piece so as to face in a direction to intersect a direction toward a center point instead of the method of raising a support piece toward a center point used conventionally.

Effect of the Invention

With the present invention, not only can a support member (retainer) be formed from the same material and process as used conventionally, but because the valve body can be prevented from sticking, a check valve having higher reliability can be provided in a simple structure similar to that used conventionally.

Moreover, in contrast to the support member (retainer) in the conventional technique where contact with the valve body is in point contact because the contact location with the valve body, i.e. the protruding top portion, is a curved surface, the support member (retainer) of the present invention includes a flat protruding top portion as the contact location with the valve body, and therefore, contact with the valve body is planar contact which enables stability when holding the valve body.

Therefore, the valve body can move vertically while remaining parallel to the valve seat, and in performing that function, achieve an excellent effect not available conventionally.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Next, a preferred embodiment of the present invention will be described with reference to drawings.

FIGS. 1A, 1B and 1Cillustrate vertical cross-sectional views of a preferred embodiment of a check valve which is the present invention. The overall configuration is substantially similar to that of the conventional technique shown inFIGS. 6A, 6B and 6Cand is configured in that an inflow opening2and an outflow opening3are formed in a cylindrical shape on both ends, respectively, and include: a case body1made of, for example, an aluminum die cast forming a cylindrically shaped valve seat4having a predetermined length in an axial direction between the inflow opening2and the outflow opening3; a disk shaped valve body5having an outer diameter slightly smaller than the inner diameter of the valve seat4and disposed with the ability to move in an axial direction of the valve seat4by a larger diameter than the inner diameter of the inflow opening2; and a support member (retainer)6of the valve body5disposed between the outflow opening3of the valve seat4and the valve body5.

Further, the support member (retainer)6, as illustrated inFIGS. 2 and 3, is provided with protruding support pieces64on the support member (retainer)6shown inFIG. 1protruding upward (valve body5direction) standing (90°)in this embodiment) at mutually equivalent angles from the center on a circular plate shaped base seat61forming an outflow window62in the center on an open edge63of the outflow window62formed in the center of the base seat61and inserted in a circular groove formed between the valve seat4and the outflow opening3of the check valve shown inFIG. 1.

Further, with the support member (retainer)6as illustrated inFIGS. 2, 3A, 3B and 3C, each support piece64of the support member (retainer)6supporting the valve body5has a linear (or planar) support part on the top portion for leveling at least in a radial direction of the base seat61.

Note that, the support member (retainer)6in this embodiment, similar to the embodiment shown inFIGS. 7, 8A, 8B and 8C, has support pieces64to support the valve body5, formed by being cut out, on the open edge63of the outflow window62of the circular base seat61having a fluid outflow window62with a predetermined diameter in the center formed by, for example, punching a metal plate such as brass or the like having an appropriate thickness, and the support pieces64are erected by bending in an intersecting direction with the base seat61. Particularly, because the support pieces64are raised in a direction to intersect with a radial direction of the base seat61rather than in the radial direction, the support pieces64have a linear (or planar) support part on the top portion for leveling at least in a radial direction of the base seat61.

This embodiment using the support member (retainer)6configured in this manner, as shown inFIG. 1A, is supported by the support pieces64of the support member (retainer)6by fluid flowing in from the inflow opening2pressing the valve body5disposed in the valve seat4in a direction toward the outflow opening3and flowing out to the outflow opening3from the outflow window62of the support member (retainer)6via the space42formed between the support pieces64and the inner circumferential surface44of the valve seat4from the gap41formed with the top surface43of the valve seat4.

At this time, in this embodiment, the support piece64of the support member (retainer)6is in a shape that extends in the radial direction of the base seat61, and instead of point contact against the valve body5as in the conventionally known check valve shown inFIGS. 6A, 6B and 6C, it supports the valve body5with at least linear contact such that the valve body5does not deflect and can move oscillating in an axial direction in an extremely stable disposition reliably in the valve seat4thereby preventing tilt and deflection by the valve body5.

Further, in this embodiment, as illustrated inFIG. 1B, when fluid having flowed through the outflow opening3flows in reverse to flow toward the inflow opening2, the check valve operates so that the fluid having flowed toward the outflow opening3flows in reverse through the valve seat4and moves the valve body5in an axial direction in the valve seat4to block the open end21of the inflow opening2, which is to say, that the check valve is put in a closed state by the valve body5tightly contacting the open end21area of the inflow opening2of the valve seat4by the fluid pressure of the reverse flowing fluid, and because also at this time, the valve body5is supported by the support member (retainer)6in a stable state in advance prior to the reverse flow, even if there is a reverse flow, the valve body5moves toward the inflow opening2direction in a state still retaining a flat disposition.

Moreover, as illustrated inFIG. 1C, with this embodiment, the space43formed between each support piece64of the support member6and the inner circumferential surface44of the valve seat4is formed narrower than the conventionally known check valve shown inFIGS. 6A, 6B and 6C, and therefore, the range of play in the valve body5is reduced and sticking, as in the conventionally known check valve, does not occur even if the valve body5tilts for some reason while open.

In addition,FIGS. 4A and 4Billustrate a different embodiment of the support member (retainer)6used in the embodiment of the present invention, and in this embodiment, the entirety of the support member (retainer)6is formed of, for example, injection molding using a hard synthetic resin material, and because this does not require a step to machine fold the support member, working is easier and a more stable item can be provided. Particularly, it is possible to form the support part of the support piece64flat with a wider width than the thickness of the material different than in the previous example to thereby employ a more stable support member (retainer)6.

In this manner, the support member (retainer)6used in the embodiments is not limited in material or method of manufacture, and as long as the support piece64erected on the base seat61is formed in a linear or planar shape having a length in a radial direction to the base seat61, the effect can be demonstrated.

In many instances entities are described herein as being coupled to other entities. It should be understood that the terms “coupled” and “connected” (or any of their forms) are used interchangeably herein and, in both cases, are generic to the direct coupling of two entities (without any non-negligible (e.g., parasitic) intervening entities) and the indirect coupling of two entities (with one or more non-negligible intervening entities). Where entities are shown as being directly coupled together, or described as coupled together without description of any intervening entity, it should be understood that those entities can be indirectly coupled together as well unless the context clearly dictates otherwise.

DESCRIPTION OF THE REFERENCE NUMERALS