JP4723980B2 - Check valve - Google Patents

Description

  The present invention relates to a backflow prevention valve suitable for use in preventing backflow of fluid.

  2. Description of the Related Art Conventionally, for example, a tubular housing in which an upper end and a lower end are connected to two pipe members piped up and down, and a valve body disposed in the housing, the upper pipe member from the lower pipe member is provided. There is known a backflow prevention valve that allows the passage of fluid toward the reverse and vice versa. The upper end portion of the housing is formed with a retaining portion for preventing the valve body from coming out of the housing. An annular valve seat that receives the valve element is provided at the lower end of the housing. The valve seat is made of a material that can be elastically deformed, such as rubber, in order to improve adhesion to the valve body.

  When the fluid flows from the lower pipe member into the housing through its lower end, the valve body is pushed upward by the pressure received from the fluid and is separated from the valve seat. Thereby, the fluid can pass through the housing, and the fluid flows into the upper pipe member through the housing. When the inflow of fluid from the lower pipe member into the housing stops or the amount of inflow decreases, the valve body descends in the housing due to the pressure received from the fluid in the upper pipe member in addition to its own weight and hits the valve seat. Touch. Thereby, since the lower end of the housing is closed by the valve body, the passage of the fluid in the housing is blocked, and the fluid is prevented from flowing from the upper tube member to the lower tube member.

  However, the axial thickness of the housing of the valve seat is relatively thick so that the valve seat is not easily deformed by the pressure received from the fluid flowing into the housing. For example, when the valve seat is attached to the housing, When the valve seat is mounted in a deformed state, only the pressure due to the weight of the valve body acting on the valve seat from the valve body and the pressure received from the fluid in the upper pipe member will follow the shape of the valve body. Cannot be deformed. For this reason, a gap is formed between the valve body and the valve seat, and the water stoppage between the valve body and the valve seat is lowered.

  Therefore, in order to ensure the water stoppage between the valve body and the valve seat, a spring for urging the valve body toward the valve seat is provided on the valve body, and the valve body is forced to the valve seat. It has been proposed to impose. According to this, even when the valve seat is attached in a deformed state when the valve seat is attached to the housing, the spring of the spring is applied in addition to the pressure from the valve body to the valve seat when the valve body comes into contact with the valve seat. Since the force acts, the deformed valve seat can be deformed so as to follow the shape of the valve body.

  However, the structure of the backflow prevention valve provided with the spring is complicated, which increases the manufacturing cost.

Therefore, in order to ensure water-stopping without increasing the manufacturing cost, instead of the above-described valve seat, an annular valve seat is integrally formed in the housing in the vicinity of the lower end thereof, and the valve body is formed. It has been proposed to mold with rubber or resin, or to coat the outer peripheral surface with rubber or resin (see, for example, Patent Documents 1 and 2). According to this backflow prevention valve, the valve body is made of rubber or the like. Since it is shape | molded by this, or is coat | covered with rubber | gum etc., a valve body and a valve seat can be closely_contact | adhered at the time of contact | abutting of the valve body to a valve seat. Thereby, the water stop between a valve body and a valve seat is securable with a simple structure.
Japanese Patent Laid-Open No. 2002-267032 (page 2-3, FIG. 1) Japanese Patent Laid-Open No. 10-231941 (page 3, FIG. 1)

  However, in order to improve the close contact between the valve body and the valve seat, the valve body is molded with rubber or resin, or the outer peripheral surface is made of rubber or resin. Since it is covered, when the valve body moves in the housing when fluid flows into the housing, friction between the valve body and the inner peripheral surface of the housing may cause so-called slippage. is there. If the valve body slips, a gap may be formed between the valve seat and the valve body depending on the contact posture of the valve body with the valve seat, and water stoppage between the valve body and the valve seat should be secured. I can't.

  Therefore, an object of the present invention is to provide a backflow prevention valve that can ensure high water-stopping without causing an increase in manufacturing cost.

In order to solve the above-mentioned problem, the invention according to claim 1 is arranged in a cylindrical housing in which one end and the other end are connected to two pipe members, and is movable in the axial direction in the housing. A valve seat having a seat surface for receiving the valve body is formed at the one end portion of the housing, and the other end portion of the housing has the valve seat from the inside of the housing. A retaining portion for preventing the valve body from coming off is formed, from one of the tube members connected to the one end of the housing toward the other tube member connected to the other end. A backflow prevention valve that allows passage of fluid and blocks passage in a reverse direction, and the housing has a water stop property between the valve body and the valve seat on the other end side of the housing of the valve seat. Elastically deformable annular to ensure And a seal member that covers the seating surface from the inner edge of the support portion to the inside of the support portion to receive the valve body. And an annular receiving portion that is sandwiched between the valve body and the seat surface when the valve body is seated on the valve seat, and the receiving portion has a thickness that is the thickness of the receiving portion. The thinner thin-walled portion is formed with a concave groove extending in the circumferential direction on the support portion side in the radial direction and at least on the seating surface side of the receiving portion in the axial direction .

  According to a second aspect of the present invention, in the first aspect of the present invention, the housing includes a first housing portion in which the retaining portion is formed and a second housing portion in which the valve seat is formed. The valve body is housed in the first housing portion, and the seal member has a support portion between the opposing end surfaces of the first housing portion and the second housing portion. It is supported by the housing by being sandwiched.

  According to a third aspect of the present invention, in the second aspect of the present invention, an annular protrusion that protrudes toward the support portion of the seal member is formed on the end surface of the first housing portion. It is characterized by being.

  According to the first aspect of the present invention, since the seal member receiving portion for securing water-stopping between the valve body and the valve seat is formed with a thin portion whose thickness is thinner than the thickness of the receiving portion, The rigidity with respect to the external force in the thin part of the receiving part is smaller than the rigidity in the part other than the thin part of the receiving part. Thereby, when the receiving portion of the seal member receives the valve body, the thickness of the receiving portion is reduced by the pressure due to its own weight received from the valve body and the pressure received through the valve body from the fluid in the upper pipe member. Compared to a uniform case, the receiving portion can be easily bent and deformed at the thin portion. Thereby, for example, even when the seal member is attached in a deformed state when the seal member is attached to the housing, it is deformed by bending and deforming the receiving portion at the thin portion when the valve body contacts the receiving portion. The receiving part of the seal member can easily follow the shape of the valve body. Therefore, a gap is formed between the seat surface and the outer peripheral surface of the valve body when the receiving portion of the seal member is sandwiched between the seat surface of the valve seat and the valve body when the valve body is seated on the valve seat. Since the sealing member is deformed at the time of mounting, the sealing member between the valve body and the valve seat is not lowered without causing a decrease in water stoppage between the valve body and the valve seat as in the prior art. Water can be reliably stopped at the receiving part.

  Further, even when the seal member is deformed when the seal member is attached to the housing, the valve body and the valve seat can be securely connected to each other by forming a thin portion in the receiving portion of the seal member without using a conventional spring. Since they can be brought into close contact with each other, the structure is simpler than that of the prior art, and therefore, the water stoppage can be secured between the valve body and the valve seat without increasing the manufacturing cost.

  Furthermore, since the sealing member according to the present invention is provided in the housing, it is possible to ensure water-stopping between the valve body and the valve seat. Therefore, in order to increase the water-stopping between the valve body and the valve seat, In order to improve the degree of adhesion, it is not necessary to mold the valve body with rubber or resin as before, or to coat the outer peripheral surface with rubber or resin. Accordingly, since the valve body can be prevented from being slipped as in the prior art by molding the valve body with rubber or the like and covering it with rubber or the like, the valve body and the valve caused by the side slip of the valve body are prevented. A decrease in the water stoppage between the seats can be reliably prevented.

  According to the invention described in claim 2, the housing has a first housing part in which a retaining part is formed, and a second housing part in which a valve seat is formed, Since the seal member is housed in the housing portion and the support portion is supported by the housing by being sandwiched between the opposite end surfaces of the first housing portion and the second housing portion, the seal member By sandwiching the supporting portion between the opposing end surfaces of the first housing portion and the second housing portion, the seal member can be easily incorporated into the housing.

  According to the third aspect of the present invention, since the annular protrusion protruding toward the support portion of the seal member is formed on the end surface of the first housing portion, the support portion of the seal member is And when pinched | interposed between 2nd housing parts, the projection part formed in the end surface of the 1st housing part can be made to bite into the support part of a sealing member. As a result, even if the seal member is deformed when the seal member is attached to the housing, the gap between the support portion and the end surface of the first housing portion when the support portion of the seal member is sandwiched between both housing portions. Can be prevented from being formed. Accordingly, water can be stopped between the end surface of the first housing portion and the support portion of the seal member, so that fluid leaks from the space between the first housing portion and the support portion of the seal member to the outside of the housing. This can be surely prevented. In particular, in the seated state of the valve body, that is, in the closed state of the backflow prevention valve, the pressure in the first housing portion increases, so that fluid easily leaks from between the first housing portion and the seal member to the outside of the housing. The outer leakage preventing action of the protrusion can reliably prevent fluid from leaking from between the first housing portion and the seal member when the check valve is closed.

  The present invention will be described with reference to the illustrated embodiments.

  FIG. 1 shows an example in which the present invention is applied to a backflow prevention valve 10 disposed between two pipe members 11a and 11b that are vertically connected.

  As shown in FIG. 1, the backflow prevention valve 10 according to the present invention includes a tubular housing 13 that has connecting ends 13 a and 13 b into which pipe members 11 a and 11 b are inserted at the upper end and the lower end, respectively, and the housing And a valve body 12 disposed therein. The valve body 12 is made of a resin sphere in the illustrated example.

  In the illustrated example, the housing 13 is mounted on the first housing portion 14 from below with a cylindrical first housing portion 14 having one connection end 13a as an upper end, and the other connection end 13b as a lower end. And a cylindrical second housing part 15.

  An annular retaining portion 16 for preventing the valve body 12 from coming out of the first housing portion 14 is formed at the upper end portion 14 a of the first housing portion 14. The retaining portion 16 protrudes inward from the inner peripheral surface 14 b of the first housing portion 14. A valve chamber 17 for accommodating the valve body 12 is defined in the first housing portion 14 below the retaining portion 16. The valve chamber 17 is open below the first housing part 14. The cross-sectional shape of the valve chamber 17 is substantially equal to the cross-sectional shape of the valve body 12, and the length dimension along the axis of the first housing portion 14 of the valve chamber 17 is larger than the diameter of the valve body 12. Thereby, the valve body 12 can move along the axis of the first housing portion 14 in the valve chamber 17. A groove portion 18 extending from the valve chamber 17 along the axis of the first housing portion 14 is formed on the inner peripheral surface 14 b of the retaining portion 16. The groove portion 18 allows passage of fluid from the lower end to the upper end of the first housing portion 14 in an open state of the backflow prevention valve 10 which will be described later. A male screw portion 19 is formed on the outer peripheral surface 14 d of the lower end portion 14 c of the first housing portion 14.

  The second housing part 15 is arranged with its axis line coinciding with the axis line of the first housing part 14, and has an outer diameter smaller than the outer diameter of the first housing part 14. In the illustrated example, the second housing portion 15 is connected to the first housing portion 14 by a connecting member 20.

  As shown in FIG. 1, the connecting member 20 has a cylindrical shape having an outer diameter substantially equal to the outer diameter of the first housing portion 14. A female screw portion 21 that can be screwed into the male screw portion 19 of the first housing portion 14 is formed on the inner peripheral surface of the upper end portion 20 a of the connecting member 20. In addition, a protruding portion 22 that protrudes inward in the radial direction of the connecting member 20 is formed at the lower end portion 20 b of the connecting member 20. The overhang amount of the overhang portion 22 is set so that the diameter of the circle defined by the tip of the overhang portion is approximately equal to the outer diameter of the second housing portion 15. At the upper end portion 15 a of the second housing portion 15, an annular engagement portion 23 that is engaged with the overhanging portion 22 of the connection member 20 from the inside of the connection member 20 is located outside the radial direction of the second housing portion 15. It protrudes in the direction.

  With the protruding portion 22 of the connecting member 20 engaged with the engaging portion 23 of the second housing portion 15 from below, the connecting member 20 is fitted to the lower end portion 14c of the first housing portion 14 from the outside. The second housing portion 15 is connected to the first housing portion 14 via the connecting member 20 by screwing the female screw portion 21 of the connecting member 20 into the male screw portion 19 of the first housing portion 14. The

  An annular valve seat 24 for receiving the valve body 12 is formed at the upper end portion 15 a of the second housing portion 15. The valve seat 24 protrudes inward in the radial direction of the second housing portion 15. On the upper surface of the valve seat 24, there is a seat surface 24a against which the outer peripheral surface 12a of the valve body 12 abuts when the valve body 12 is seated on the valve seat. In the illustrated example, the seat surface 24 a is formed in a mortar shape in which the inner diameter of the valve seat 24 gradually decreases from the upper side to the lower side of the second housing portion 15.

  When a fluid flows into the second housing part 15 from the pipe member 11b located on the lower side of the backflow prevention valve 10, that is, when the fluid flows in the forward direction, the valve body is caused by the upward pressure received from the fluid. 12 separates from the valve seat 24 and the upper end of the second housing part 15 is opened. At this time, the groove 18 extending along the axis of the first housing portion 14 is formed on the inner peripheral surface 14b of the retaining portion 16 from the valve chamber 17 as described above. Even when the valve body 12 is pressed against the retaining portion 16, a gap is formed between the valve body 12 and the inner peripheral surface 14 b of the first housing portion 14. Thereby, the fluid flows into the first housing part 14 from the second housing part 15, passes through the groove part 18, passes through the upper end of the first housing part 14, and enters the pipe member 11 a located above the upper part. Flow into.

  On the other hand, when the inflow of the fluid from the lower pipe member 11b to the second housing portion 15 is stopped or the amount of the inflow is reduced, the valve element 12 receives the pressure received from the fluid in the upper pipe member 11a in addition to its own weight. The valve chamber 17 is lowered and seated on the valve seat 24. In the seated state of the valve body 12, the upper end of the second housing portion 15 is closed by the valve body 12. Accordingly, the fluid is prevented from flowing into the second housing portion 15 from the first housing portion 14, that is, the fluid is prevented from flowing in the direction opposite to the forward direction.

  Therefore, the backflow prevention valve 10 is opened when the fluid flows from the lower pipe member 11b, and allows the fluid to pass from the lower pipe member 11b to the upper pipe member 11a, and the lower pipe member 11b. When the inflow of fluid from the pipe stops or the amount of inflow decreases, the closed state is established, and the passage of fluid from the upper pipe member 11a to the lower pipe member 11b is blocked.

  The backflow prevention valve 10 according to the present invention is provided with an annular seal member 25 between the valve body 12 and the valve seat 24 to ensure water-stopping.

  The seal member 25 is made of an elastically deformable material such as rubber, and is supported between the first housing part 14 and the second housing part 15. As shown in FIGS. 1 and 2, the seal member 25 protrudes inward of the support portion 26 from the inner edge of the support portion 26 and the annular support portion 26 supported by the housing portions 14 and 15. And an annular receiving portion 27 for receiving.

  The protruding amount of the receiving portion 27 is set to a size that covers the seat surface 24 a of the valve seat 24. The receiving portion 27 is formed with a thin portion 28 whose thickness is thinner than the thickness of the receiving portion 27. In the illustrated example, the thin portion 28 is formed in the receiving portion 27 by forming grooves extending in the circumferential direction of the receiving portion 27 on the upper surface and the lower surface of the receiving portion 27, respectively. The thickness dimension of the thin portion 28 is set to 0.7 to 1.2 mm in the illustrated example.

  The support member 26 is sandwiched between the lower end surface 14e of the first housing portion 14 and the upper end surface 15b of the second housing portion 15 so that the seal member 25 is interposed between the housing portions 14 and 15. It is supported.

  When the receiving portion 27 receives the valve body 12 when the valve body 12 is seated on the valve seat 24, due to the pressure due to the weight of the valve body received from the valve body 12 and the pressure received from the fluid in the upper pipe member 11a, As shown in FIG. 3, the receiving portion 27 is inclined toward the seating surface 24 a of the valve seat 24 when the thin portion 28 is bent and deformed, and is sandwiched between the valve body 12 and the valve seat 24. Thereby, since the receiving part 27 closely_contact | adheres to the outer peripheral surface 12a of the valve body 12, and the seat surface 24a of the valve seat 24, the water stop property between the valve body 12 and the valve seat 24 is ensured.

  In order to ensure that the water stop between the valve body 12 and the valve seat 24 is properly secured, the seat surface 24a is used to ensure that the receiving portion 27 is in close contact with the outer peripheral surface 12a of the valve body 12 and the seat surface 24a of the valve seat 24. Is preferably set to 45 ° or less.

  Furthermore, in the backflow prevention valve 10 according to the present invention, a protrusion 29 is formed on the lower end surface 14e of the first housing portion 14 so as to extend along the lower end surface 14e and protrude downward. In the illustrated example, the protrusion 29 has a hemispherical tip. The projecting portion 29 bites into the support portion 26 of the seal member 25 disposed between the housing portions 14 and 15 when the connection member 20 is tightened when the second housing portion 15 is attached to the first housing portion 14. . Thereby, the water stop between the 1st housing part 14 and the sealing member 25 increases.

  According to the present embodiment, as described above, the receiving portion 27 of the annular elastically deformable seal member 25 for securing the water stoppage between the valve body 12 and the valve seat 24 is more than the thickness of the receiving portion. Since the thin thin portion 28 is formed, the rigidity of the receiving portion 27 with respect to the external force in the thin portion 28 is smaller than the rigidity of the receiving portion 27 other than the thin portion 28.

  As a result, when the receiving portion 27 receives the valve body 12, the pressure of the weight received from the valve body and the pressure received through the valve body 12 from the fluid in the upper pipe member 11a are reduced. Compared to the case where the thickness is uniform, the receiving portion 27 can be easily bent and deformed by the thin portion 28.

  Thereby, for example, even when the seal member 25 is attached in a deformed state when the check valve 10 is assembled, the receiving portion 27 is bent and deformed by the thin portion 28 when the valve body 12 contacts the receiving portion 27. The receiving portion 27 of the deformed seal member 25 can easily follow the shape of the valve body 12.

  Accordingly, when the receiving portion 27 of the seal member 25 is sandwiched between the seat surface 24 a of the valve seat 24 and the valve body 12 when the valve seat 24 is seated, the seal member 25 is connected to the seat surface 24 a and the outer peripheral surface 12 a of the valve body 12. Can be brought into close contact with each other without forming a gap therebetween, so that the sealing performance between the valve body 12 and the valve seat 24 due to deformation of the seal member 25 at the time of attachment is not reduced. The water between the valve body 12 and the valve seat 24 can be reliably stopped by the receiving portion 27 of the seal member 25.

  Further, even when the seal member 25 is deformed when the check valve 10 is assembled, the valve body 12 and the valve seat 24 are securely connected to each other by forming the thin portion 28 in the receiving portion 27 without using a spring as in the prior art. Therefore, it is possible to ensure water-stopping between the valve body 12 and the valve seat 24 without causing an increase in manufacturing cost.

  Furthermore, since the sealing member 25 according to the present invention is provided between the housing parts 14 and 15, water-tightness can be secured between the valve body 12 and the valve seat 24. In order to improve the adhesion between the valve body 12 and the valve seat 24 in order to improve the water-stopping performance, the valve body 12 is made of a conventional sphere formed of rubber or resin, or the outer peripheral surface is made of rubber or resin. There is no need to consist of coated metal spheres. Therefore, since the valve body 12 is prevented from being partly bent by molding the valve body 12 with rubber or the like, or by covering the valve body 12 with rubber or the like, the valve caused by the side slip of the valve body 12 is prevented. A decrease in the water stoppage between the body 12 and the valve seat 24 can be reliably prevented.

  In addition, as described above, the seal member 25 has the support portion 26 sandwiched between the lower end surface 14e of the first housing portion 14 and the upper end surface 15b of the second housing portion 15 so that both housing portions are supported. Since it is supported between 14 and 15, the seal member 25 can be easily incorporated into the housing 13.

  Further, as described above, the protrusion that bites into the support portion 26 when the support portion 26 of the seal member 25 is sandwiched between the first and second housing portions 14 and 15 on the lower end surface 14e of the first housing portion 14. Since the portion 29 is formed, even if the seal member 25 is deformed when the check valve 10 is assembled, the support portion 26 is sandwiched between the housing portions 14 and 15 when the support portion 26 of the seal member 25 is sandwiched. It is possible to prevent a gap from being formed between the lower end surface 14e of the first housing portion 14 and the first housing portion 14. Accordingly, the gap between the lower end surface 14e of the first housing part 14 and the support part 26 of the seal member 25 can be stopped, so that the gap between the first housing part 14 and the support part 26 of the seal member 25 can be stopped. It is possible to reliably prevent the fluid from leaking out of the housing 13.

  In particular, in the closed state of the backflow prevention valve 10, the pressure in the first housing portion 14 increases, so that fluid easily leaks from the space between the first housing portion 14 and the seal member 25 to the outside of the housing 13. The anti-leakage action of the protrusion 29 can surely prevent fluid from leaking from between the first housing part 14 and the seal member 25 when the backflow prevention valve 10 is closed.

  Further, as described above, since the tip of the projection 29 is hemispherical, the pressure acting on the support 26 from the projection 29 when the projection 29 bites into the support 26 of the seal member 25 is applied. Since it is dispersed, damage to the support portion 26 due to the protrusion 29 biting into the support portion 26 can be reliably suppressed.

  In the present embodiment, an example in which the tip of the protrusion 29 is hemispherical has been shown, but instead, for example, a protrusion having a trapezoidal longitudinal section can be applied to the present invention.

  Further, in the present embodiment, the example in which the present invention is applied to the backflow prevention valve 10 in which the housing 13 includes the first housing portion 14 and the second housing portion 15 is shown, but instead of this, FIG. As shown in FIG. 4, the present invention can be applied to the backflow prevention valve 100 in which the housing 30 includes a first housing part 31, a second housing part 32, and a third housing part 33.

  In the example shown in FIG. 4, the valve body 34 is accommodated in the first housing portion 31. The second housing portion 32 and the third housing portion 33 are connected to the upper end portion 31a and the lower end portion 31b of the first housing portion 31 by connection members 35 and 36, respectively, similarly to the example shown in FIG. Yes. Between the 1st housing part 31 and the 2nd housing part 32, the O-ring 37 for stopping water between them is provided.

  In the example shown in FIG. 4, a seat surface 38 that receives the valve body 34 is defined at the inner edge portion of the upper end surface 33 a of the third housing portion 33.

  An annular member 39 that allows insertion of the valve body 34 is fitted to the lower end portion 31 b of the first housing portion 31. An O-ring 40 is provided between the annular member 39 and the first housing portion 31 to stop water between them. The annular member 39 supports a seal member 41 for ensuring water stoppage between the valve body 34 and the seat surface 38.

  In the illustrated example, the seal member 41 is made of an elastically deformable material such as rubber, and has an annular support portion 42 inserted into a groove 39b formed in the lower surface 39a of the annular member 39, and the support portion. A receiving portion 43 is provided so as to cover the seating surface 38 from the lower end thereof and to be spaced upwardly from the seating surface 38 to receive the valve element 34. Further, the seal member 41 is formed with a thin portion 44 between the support portion 42 and the receiving portion 43 having a thickness smaller than those thicknesses.

  When the valve body 34 is seated, the receiving portion 43 is the example shown in FIG. 1 due to the pressure due to the weight of the valve body received from the valve body 34 and the pressure received through the valve body 34 from the fluid in the upper pipe member 11a. In the same manner as described above, the thin portion 44 is bent and deformed to be inclined toward the seating surface 38, and is sandwiched between the valve body 34 and the seating surface 38. Thereby, since the receiving part 43 closely_contact | adheres to the outer peripheral surface 34a and the seat surface 38 of the valve body 34, the water stop property between the valve body 34 and the seat surface 38 is ensured.

  The backflow prevention valve 10 shown in FIG. 1 and the backflow prevention valve 100 shown in FIG. 4 are connected to the pipe members 11a and 11b, respectively. Table 1 shows the measurement results of the water stoppage. In Table 1, the backflow prevention valve 10 shown in FIG. 1 is shown as Example 1, the backflow prevention valve 100 shown in FIG. 4 is shown as Example 2, and the backflow prevention valve shown in FIG. A comparative example is shown in which the protruding portion 29 is not formed on the lower end surface 14e of the first housing portion 14 in the valve 10.

表１に示された測定結果によれば、実施例２において、水圧０．０３ＭＰａで流体を順方向に流したとき、弁体３４を押し上げることができず、すなわち、逆流防止弁１００を開状態にすることができず、流体を流すことができなかったが、水圧を上げることにより、流体を流すことができた。また、実施例１、実施例２及び比較例の全てにおいて、逆流防止機能を確認することができた。更に、実施例１と比較例との比較において、流体を逆方向に流したときに、第一のハウジング部１４の下端面１４ｅに形成された突起部２９による第一のハウジング部１４及びシール部材２５間の外漏れ防止効果を確認することができた。

According to the measurement results shown in Table 1, in Example 2, when the fluid was flowed in the forward direction at a water pressure of 0.03 MPa, the valve body 34 could not be pushed up, that is, the check valve 100 was opened. However, the fluid could not be flowed, but the fluid could be flowed by increasing the water pressure. Moreover, the backflow prevention function was able to be confirmed in all of Example 1, Example 2, and a comparative example. Further, in the comparison between the first embodiment and the comparative example, when the fluid is flowed in the opposite direction, the first housing portion 14 and the seal member due to the protrusion 29 formed on the lower end surface 14e of the first housing portion 14 are used. The effect of preventing leakage between 25 was confirmed.

  In the example shown in FIGS. 1 to 4, the thickness of the thin portions 28 and 44 of the seal members 25 and 41 is set to 0.7 to 1.2 mm. The wall thicknesses 28 and 44 can be set within a range of 0.5 to 3 mm. Within this range, the seal members 25 and 41 are not easily broken at the thin portions 28 and 44 due to bending deformation, and the receiving portions 27 and 34 and the seating surfaces 24a and 38 are received by the receiving portions 27 and 44, respectively. The seal members 25, 41 can be sufficiently bent and deformed by the thin portions 28, 44 in order to bring 43 into close contact.

  In the example shown in FIGS. 1 to 4, the thin portions 28 and 44 form grooves along the circumferential direction of the receiving portions 27 and 43 on the upper and lower surfaces of the receiving portions 27 and 43, respectively. Although the example formed in 27,44 was shown instead, by forming a groove in either one of the upper surface and the lower surface of the receiving portions 27, 43, the thin-walled receiving portions 27, 43 are formed. Can be formed.

  Furthermore, in the example shown in FIGS. 1 to 4, the example in which the valve bodies 12 and 34 are made of resin spheres has been shown, but instead, the valve bodies 12 and 34 are made of a material other than resin and are spherical. It can comprise with the valve body which makes shapes other than.

  Moreover, in the example shown in FIGS. 1 to 4, the example in which the present invention is applied to the backflow prevention valve 10 arranged between the pipe members 11 a and 11 b that are piped up and down is shown. The present invention can be applied to a backflow prevention valve disposed between two pipe members that are piped in the lateral direction.

1 is a longitudinal sectional view schematically showing a backflow prevention valve according to the present invention. It is a cross-sectional view which shows schematically the sealing member which concerns on this invention. It is a longitudinal cross-sectional view which shows roughly the seating state of the valve body to the valve seat which concerns on this invention. It is a longitudinal cross-sectional view which shows the other Example of a backflow prevention valve schematically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,100 Backflow prevention valve 12,34 Valve body 11a, 11b Pipe member 13 Housing 14 First housing part 15 Second housing part 16 Detachment part 24 Valve seat 24a, 38 Seat surface 25, 41 Seal member 26, 42 Support Part 27, 43 Receiving part 28, 44 Thin part 29 Projection part

Claims (3)

A cylindrical housing in which one end and the other end are connected to two pipe members;
A valve body disposed in the housing so as to be movable in the axial direction thereof,
A valve seat having a seating surface for receiving the valve body is formed at the one end portion of the housing, and the other end portion of the housing is for preventing the valve body from slipping out of the housing. The retaining part is formed,
A backflow prevention valve that allows passage of fluid from one tube member connected to the one end of the housing to the other tube member connected to the other end and blocks passage in the opposite direction. There,
The housing is provided with an elastically deformable annular seal member on the other end portion side of the housing of the valve seat for securing water stoppage between the valve body and the valve seat. The member includes an annular support portion supported by the housing;
The valve body projects from the inner edge of the support portion to the inside of the support portion so as to receive the valve body, and is sandwiched between the valve body and the seat surface when the valve body is seated on the valve seat. An annular receiving part,
The receiving part has a thin part whose thickness is thinner than the thickness of the receiving part ,
A backflow prevention valve characterized in that a concave groove extending in the circumferential direction is provided on the support portion side in the radial direction and at least on the seating surface side of the receiving portion in the axial direction .   The housing has a first housing part in which the retaining part is formed and a second housing part in which the valve seat is formed, and the valve body is housed in the first housing part. The seal member is supported by the housing by the support portion being sandwiched between the opposing end surfaces of the first housing portion and the second housing portion. The backflow prevention valve according to claim 1.   3. The backflow prevention valve according to claim 2, wherein an annular protrusion that protrudes toward the support portion of the seal member is formed on the end surface of the first housing portion.

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