Abstract:
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.

Description:
TECHNICAL FIELD 
       [0001]    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 
       [0002]    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. 
         [0003]    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. 
         [0004]    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 in  FIG. 5A , is configured such that a valve body  332  and a valve seat  334  are inserted to attach in a valve holder  320 , and assembled by engaging a projecting part  324  to a groove  338  of the valve body  332 . With this check valve  330 , as illustrated in  FIG. 5B , the valve body  332  becomes an open state by abutting onto a valve stopper  326  made from a curved longitudinal beam member, and also becomes a close state by abutting the valve body  332  onto a valve seat  336  by reverse direction pressure. 
         [0005]    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. 
         [0006]    Furthermore, a check valve illustrated in  FIGS. 6A ,  6 B and  6 C is 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 in  FIGS. 5A and 5B . It is configured such that a case body  1  is made of, for example, aluminum die cast, with a cylindrical inflow opening  2  and an outflow opening  3  formed respectively in both ends, as well as a cylindrical valve seat  4 , having a predetermined length, is formed in the axial direction between the inflow opening  2  and the outflow opening  3 , a disk-shaped valve body  5  with an outer diameter having a slightly smaller diameter than the inner diameter of the valve seat  4  as well as a larger diameter than the inner diameter of the inflow opening  2 , is disposed with an ability to move in the axial direction of the valve seat  4 , and a support member (retainer)  6  of the valve body  5  that is disposed between the outflow opening  3  of the valve seat  4  and the valve body  5 . 
         [0007]    Moreover, the support member (retainer)  6  is configured as illustrated in  FIGS. 7 ,  8 A,  8 B and  8 C where a disc-shaped base seat  61  that forms an outflow window  62  in the center that is fit into a circular circumferential groove formed between the outflow opening  3  and the valve seat  4  as illustrated in  FIGS. 6A ,  6 B and  6 C, and support pieces  64  of the valve body  5  illustrated in  FIGS. 6A ,  6 B and  6 C that are provided in an upwardly projecting manner (the valve body  5  direction) in an open edge  63  of the outlet window  62  formed in the center of the base  61  are projected as illustrated in  FIGS. 7 ,  8 A,  8 B and  8 C. 
         [0008]    Also, in a check valve according to the present embodiment, as illustrated in  FIG. 6A , a predetermined gap  41  is formed between the top surface  43  of the valve seat  4  because the valve body  5  disposed in the valve seat  4  is pressed in the outflow opening  3  direction by the fluid normally entering from the inflow opening  2  to be supported by the support pieces  64  of the support member (retainer)  6 . 
         [0009]    Accordingly, the fluid entered from the inflow opening  2  flows towards the outflow opening  3  from the inflow window  62  of the support member (retainer)  6  via a space  42  formed between an inner peripheral surface  44  of the valve seat  4  and the support piece  64  from the gap  41 . 
         [0010]    When the flow of the fluid changes in this condition, in other words, when the fluid that has been flowing toward the outflow opening  3  flows in reverse and flows in the direction of the inflow opening  2 , the open end  21  of the inflow opening  2  is closed by moving the valve body  5  in the axial direction within the valve seat  4  because the fluid that has been flowing toward the outflow opening  3  flows in reverse to operate the check valve. That is, as illustrated in  FIG. 6B , the valve body  5  tightly contacts the open end  21  area of the inflow opening  2  of the valve seat  4  due to the fluid pressure of the reverse flow and the check valve becomes the close state. 
       Documents of the Related Art 
       [0011]    Japanese Unexamined Patent Application No. H10-288265 
         [0012]    Japanese Examined Patent Application No. H07-101066 
         [0013]    Japanese Unexamined Patent Application No. 2010-60110 
       SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
       [0014]    However, the conventionally known support member (retainer)  6  is, for example, machine pressed in a metal circular plate of an appropriate thickness and formed with support pieces  64  for supporting the center of the outflow window  62  and the valve body  5 , and particularly, the tip ends of the support pieces  64  exhibit a horseshoe shape by bending the side surface upward, and as a result, the valve body  5 , when releasing, supports the valve body  5  in a point contact state by respective tip ends of each support piece  64 . 
         [0015]    Accordingly, the valve body  5  is not supported by the support member (retainer)  6  in a stable state, and a protruding position of each support piece  64  on the support member (retainer)  6  is in a position separated from the inner circumferential surface  44  of the valve seat  4 . That is, because there is a large range of play in the valve body, when a fluid is applied to the valve body  5  at a pressure biased, for example, in a direction toward the outflow opening  3  with respect to the installation direction, then the valve body will tilt to an angle where one end of the valve  5  is deeply inserted into a space  42  positioned between the inner circumferential surface  44  of the valve seat  4  and each of the support pieces  64  as shown in  FIG. 6C . Therefore, the valve body  5  gets stuck due to the 3 points of contact with the inner circumferential surface  44  of the valve seat  4 , each of the support pieces  64 , and the top portion  43  of the valve seat  4 , 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. 
         [0016]    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 
       [0017]    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 support piece of the valve body protruded in the valve body direction on a disk shaped base seat where the support member (retainer) is formed centrally inserted in a circular groove formed between the outflow opening and a valve seat and on an open edge of an outflow window formed in the center of the base seat; wherein each support piece of the support member (retainer) supporting the 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. 
         [0018]    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. 
         [0019]    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 
       [0020]    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. 
         [0021]    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. 
         [0022]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIGS. 1A ,  1 B and  1 C illustrate vertical cross-sectional views of a check valve according to a preferred embodiment of the present invention. 
           [0024]      FIG. 2  is a perspective view illustrating a support member used in the embodiment illustrated in  FIGS. 1A ,  1 B and  1 C. 
           [0025]      FIGS. 3A ,  3 B and  3 C illustrate the support member shown in  FIG. 2 , while  FIG. 3A  is a top view,  FIG. 3B  is a bottom view, and  FIG. 3C  is a side view. 
           [0026]      FIGS. 4A and 4B  illustrate a different support member used in the embodiment illustrated in  FIGS. 1A ,  1 B and  1 C, while  FIG. 4A  is a top view and  FIG. 4B  is a vertical cross-sectional view. 
           [0027]      FIGS. 5A and 5B  are a cross-sectional views of a state of use of the check valve of the conventional technique described in Japanese Unexamined Patent Application No. 2010-60110. 
           [0028]      FIGS. 6A ,  6 B and  6 C are vertical cross-sectional views illustrating the conventional example. 
           [0029]      FIG. 7  is a perspective view illustrating a support member used in the conventional example illustrated in  FIGS. 6A ,  6 B and  6 C. 
           [0030]      FIGS. 8A ,  8 B and  8 C illustrate the support member shown in  FIG. 7 , while  FIG. 8A  is a top view,  FIG. 8B  is a bottom view, and  FIG. 8C  is a side view. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0031]    Next, a preferred embodiment of the present invention will be described with reference to drawings. 
         [0032]      FIGS. 1A ,  1 B and  1 C illustrate 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 in  FIGS. 6A ,  6 B and  6 C and is configured in that an inflow opening  2  and an outflow opening  3  are formed in a cylindrical shape on both ends, respectively, and include: a case body  1  made of, for example, an aluminum die cast forming a cylindrically shaped valve seat  4  having a predetermined length in an axial direction between the inflow opening  2  and the outflow opening  3 ; a disk shaped valve body  5  having an outer diameter slightly smaller than the inner diameter of the valve seat  4  and disposed with the ability to move in an axial direction of the valve seat  4  by a larger diameter than the inner diameter of the inflow opening  2 ; and a support member (retainer)  6  of the valve body  5  disposed between the outflow opening  3  of the valve seat  4  and the valve body  5 . 
         [0033]    Further, the support member (retainer)  6 , as illustrated in  FIGS. 2 ,  3 A,  3 B and  3 C, is provided with protruding support pieces  64  on the valve body  5  shown in  FIGS. 1A ,  1 B and  1 C protruding upward (valve body  5  direction) standing (90° in this embodiment) at mutually equivalent angles from the center on a circular plate shaped base seat  61  forming an outflow window  62  in the center on an open edge  63  of the outflow window  62  formed in the center of the base seat  61  and inserted in a circular groove formed between the valve seat  4  and the outflow opening  3  of the check valve shown in  FIGS. 1A ,  1 B and  1 C. 
         [0034]    Further, with the support member (retainer)  6  as illustrated in  FIGS. 2 ,  3 A,  3 B and  3 C, each support piece  64  of the support member (retainer)  6  supporting the valve body  5  has a linear (or planar) support part on the top portion for leveling at least in a radial direction of the base seat  61 . 
         [0035]    Note that, the support member (retainer)  6  in this embodiment, similar to the embodiment shown in  FIGS. 7 ,  8 A,  8 B and  8 C, has support pieces  64  to support the valve body  5 , formed by being cut out, on the open edge  63  of the outflow window  62  of the circular base seat  61  having a fluid outflow window  62  with 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 pieces  64  are erected by bending in an intersecting direction with the base seat  61 . Particularly, because the support pieces  64  are raised in a direction to intersect with a radial direction of the base seat  61  rather than in the radial direction, the support pieces  64  have a linear (or planar) support part on the top portion for leveling at least in a radial direction of the base seat  61 . 
         [0036]    This embodiment using the support member (retainer)  6  configured in this manner, as shown in  FIG. 1A , is supported by the support pieces  64  of the support member (retainer)  6  by fluid flowing in from the inflow opening  2  pressing the valve body  5  disposed in the valve seat  4  in a direction toward the outflow opening  3  and flowing out to the outflow opening  3  from the outflow window  62  of the support member (retainer)  6  via the space  42  formed between the support pieces  64  and the inner circumferential surface  44  of the valve seat  4  from the gap  41  formed with the top surface  43  of the valve seat  4 . 
         [0037]    At this time, in this embodiment, the support piece  64  of the support member (retainer)  6  is in a shape that extends in the radial direction of the base seat  61 , and instead of point contact against the valve body  5  as in the conventionally known check valve shown in  FIGS. 6A ,  6 B and  6 C, it supports the valve body  5  with at least linear contact such that the valve body  5  does not deflect and can move oscillating in an axial direction in an extremely stable disposition reliably in the valve seat  4  thereby preventing tilt and deflection by the valve body  5 . 
         [0038]    Further, in this embodiment, as illustrated in  FIG. 1B , when fluid having flowed through the outflow opening  3  flows in reverse to flow toward the inflow opening  2 , the check valve operates so that the fluid having flowed toward the outflow opening  3  flows in reverse through the valve seat  4  and moves the valve body  5  in an axial direction in the valve seat  4  to block the open end  21  of the inflow opening  2 , which is to say, that the check valve is put in a closed state by the valve body  5  tightly contacting the open end  21  area of the inflow opening  2  of the valve seat  4  by the fluid pressure of the reverse flowing fluid, and because also at this time, the valve body  5  is supported by the support member (retainer)  6  in a stable state in advance prior to the reverse flow, even if there is a reverse flow, the valve body  5  moves toward the inflow opening  2  direction in a state still retaining a flat disposition. 
         [0039]    Moreover, as illustrated in  FIG. 1C , with this embodiment, the space  43  formed between each support piece  64  of the support member  6  and the inner circumferential surface  44  of the valve seat  4  is formed narrower than the conventionally known check valve shown in  FIGS. 6A ,  6 B and  6 C, and therefore, the range of play in the valve body  5  is reduced and sticking, as in the conventionally known check valve, does not occur even if the valve body  5  tilts for some reason while open. 
         [0040]    In addition,  FIGS. 4A and 4B  illustrate a different embodiment of the support member (retainer)  6  used in the embodiment of the present invention, and in this embodiment, the entirety of the support member (retainer)  6  is 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 piece  64  flat 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 . 
         [0041]    In this manner, the support member (retainer)  6  used in the embodiments is not limited in material or method of manufacture, and as long as the support piece  64  erected on the base seat  61  is formed in a linear or planar shape having a length in a radial direction to the base seat  61 , the effect can be demonstrated. 
         [0042]    All features, elements, components, functions, and steps described with respect to any embodiment provided herein are intended to be freely combinable and substitutable with those from any other embodiment. If a certain feature, element, component, function, or step is described with respect to only one embodiment, then it should be understood that that feature, element, component, function, or step can be used with every other embodiment described herein unless explicitly stated otherwise. This paragraph therefore serves as antecedent basis and written support for the introduction of claims, at any time, that combine features, elements, components, functions, and steps from different embodiments, or that substitute features, elements, components, functions, and steps from one embodiment with those of another, even if the following description does not explicitly state, in a particular instance, that such combinations or substitutions are possible. Express recitation of every possible combination and substitution is overly burdensome, especially given that the permissibility of each and every such combination and substitution will be readily recognized by those of ordinary skill in the art upon reading this description. 
         [0043]    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. 
         [0044]    While the embodiments are susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that these embodiments are not to be limited to the particular form disclosed, but to the contrary, these embodiments are to cover all modifications, equivalents, and alternatives falling within the spirit of the disclosure. Furthermore, any features, functions, steps, or elements of the embodiments may be recited in or added to the claims, as well as negative limitations that define the inventive scope of the claims by features, functions, steps, or elements that are not within that scope. 
       DESCRIPTION OF THE REFERENCE NUMERALS 
       [0000]    
       
         
           
               1  case body 
               2  inflow opening 
               3  outlet opening 
               4  valve seat 
               5  valve body 
               6  support member (retainer) 
               21  open end 
               41  gap 
               42  space 
               43  top portion 
               44  inner circumferential surface 
               61  base seat 
               62  outflow window 
               63  open edge 
               64  support piece