JP2012255471A - Check valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a check valve to be used in a pipe of a water heater or the like and endures a high back pressure even without increasing a plate thickness and secures a desired flow rate.SOLUTION: In the check valve 1 included in a pipe whose diameter is 12 to 22 mm includes: a cylindrical body 2 having a valve seat 2b; a valve stem 4 slidably disposed on the body and equipped with a flange 4b; a periphery 5a entirely formed into a disc shape with a hot water durable general rubber material and coming in contact with and separated from the valve seat; and a disc-like center 5b thicker in the plate thickness than the periphery. The center includes a valve 5 abutting on the flange of the valve stem, and a coil spring 6 pressing the flange of the valve stem to the valve seat side. The leakage of a fluid between the valve and the valve seat is 0.5 cm/min or smaller, and t≤0.4L-0.04 and t≥0.8 is satisfied, when t (mm) is the plate thickness of the periphery of the valve, D1 (mm) is the outer diameter of the center of the valve, D2 (mm) is the opening diameter of the valve, and the length L of the seal is (D2-D1)/2.

Description

  The present invention relates to a check valve disposed inside a pipe or the like through which hot water flows, such as a pipe of a water heater.

  As a check valve used in a low-pressure cold / hot water circuit, a hot water supply circuit that separates miscellaneous water and clean water, etc., Patent Document 1 discloses a valve seat formed in a cylindrical case, and the inside of the case. A check valve for preventing a back flow of fluid between the valve stem and a disc-shaped elastic valve body that abuts the top of the peripheral wall of the valve seat on the valve stem, and this disc-shaped elastic valve body is connected to the peripheral wall of the valve seat. There is disclosed a check valve provided with a pressing means for pressing in a direction and a receiving portion for supporting a disk-like elastic valve element.

Japanese Patent No. 3876297

  The conventional check valve can prevent water leakage even when pressure (back pressure) is applied in the backflow direction by pressing the disk-like elastic valve body in the direction of the peripheral wall of the valve seat by the pressing means. By constituting the disc-like elastic valve body with a rubber-like material having low adhesion, low hardness, and high strain, the water leakage preventing effect can be reliably maintained even when hair or the like is caught. That is, the rubber valve body used for the check valve needs to use a rubber material with low hardness, and is not described directly in Patent Document 1, but when using, for example, an FKM material for hot water as rubber. It was necessary to use a low hardness, for example, a rubber hardness of about 60 Hs.

  However, the low-stickiness, low-hardness, and high-distortion rubber-like material is not a general-purpose material, so it easily deteriorates when used in warm water and is inferior in durability, so it is not suitable for incorporation in piping such as a water heater. In addition, since this material is easy to bend and difficult to withstand high-pressure reverse pressure, it is necessary to increase the plate thickness, and accordingly, the lift amount of the valve body is reduced and the flow rate is restricted. It was.

  Therefore, the present invention has been made in view of the problems in the above-described conventional check valve, and can be suitably used inside a pipe such as a water heater in which hot water flows, and without increasing the plate thickness. An object of the present invention is to provide a check valve that can withstand a high back pressure and can secure a desired flow rate.

In order to achieve the above object, the present invention is a check valve incorporated in a pipe having a diameter of 12 mm or more and 22 mm or less, and a cylindrical main body having a valve seat, and a slidable arrangement on the main body. A valve shaft provided with a flange portion, a general-purpose rubber material having durability with hot water, and formed into a disc shape as a whole, and an outer peripheral portion contacting and separating from the valve seat, and a disc thicker than the outer peripheral portion A valve body that contacts the flange portion of the valve shaft, and a coil spring that presses the flange portion of the valve shaft toward the valve seat side, In both cases where the pressure at which the fluid existing inside presses the valve body toward the valve seat is weak and strong, the amount of fluid leakage between the valve body and the valve seat is 0.5 cm. in ^{3 /} min or less and comprising a check valve, the plate thickness of the outer peripheral portion of the valve body [mm], when the outer diameter of the central portion of the valve body is D1 [mm], the opening diameter of the valve seat is D2 [mm], and the seal length L is L = (D2−D1) / 2 Further, t ≦ 0.4L−0.04 and t ≧ 0.8 are satisfied.

According to the present invention, the valve body is formed of a general-purpose rubber material having hot water durability, and the thickness t of the outer peripheral portion of the valve body, the outer diameter D1 of the central portion of the valve body, and the opening diameter D2 of the valve seat are By configuring so as to have the above-mentioned predetermined relationship, the fluid between the valve body and the valve seat can be removed when the pressure that the fluid existing inside the pipe presses the valve body toward the valve seat is weak or strong. The amount of leakage can be 0.5 cm ³ / min or less. Accordingly, it can be suitably used in a pipe such as a hot water heater through which hot water flows, and can withstand a high-pressure counter pressure without increasing the plate thickness, and a desired flow rate can be secured.

  In the check valve, when the pressure that presses the valve body toward the valve seat is weak by the fluid existing in the pipe, the pressure can be set to 1.0 kPa or less and exists in the pipe. When the pressure that presses the valve element toward the valve seat is high by the fluid to be applied, the pressure can be set to 0.6 MPa to 3.5 MPa.

  In the check valve, the general-purpose rubber material can have a rubber hardness of 70 Hs, and the rubber can be a general-purpose material for a hot water FKM material.

  Furthermore, in the above-described check valve, the distance between the opposing surfaces of the flange portion of the valve shaft and the outer peripheral portion of the valve body can be 1 mm or less, and the outer diameter D3 of the valve body is 9 to 15 mm. The opening diameter D2 of the valve seat can be 8 to 14 mm, and the seal length L can be 2.1 mm or more.

  In the check valve, the valve shaft includes a rod-like base portion, and the base portion can be slidably disposed in a guide hole provided in the main body.

  In the check valve, the guide hole may be formed such that the inner surface of the guide hole has a smaller inner diameter on the center side than both end surfaces of the guide hole.

  Furthermore, in the check valve, a through path that penetrates in the axial direction can be formed between the guide hole and the base portion.

  As described above, according to the present invention, it can be suitably used in piping such as a hot water heater or the like through which hot water flows, and can withstand high pressure reverse pressure without increasing the plate thickness, ensuring a desired flow rate. A check valve that can be provided can be provided.

It is sectional drawing which shows one Embodiment of the non-return valve concerning this invention. It is sectional drawing for demonstrating operation | movement of the non-return valve of FIG. It is a graph for demonstrating the test example of the non-return valve of FIG. It is sectional drawing which shows the modification of the valve body of the non-return valve concerning this invention. It is sectional drawing which shows the structural example of the base part of the valve shaft of the check valve concerning this invention, and the guide hole of a guide.

  Next, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a check valve according to the present invention. The check valve 1 is mounted on a cylindrical case 2 having a valve seat 2b and a left opening of the case 2, and the valve A guide 3 that slidably guides the shaft 4, a valve shaft 4 that is guided in the left-right direction by the guide 3, a valve body 5 that is mounted adjacent to the flange portion 4b of the valve shaft 4, the guide 3 and the valve The coil spring 6 is interposed between the shaft 4 and presses the valve shaft 4 toward the valve seat 2b.

  The case 2 is located between the cylindrical base portion 2a, the valve seat 2b that protrudes to the left in a cylindrical shape within the base portion 2a, the flange portion 2c, and the base portion 2a and the flange portion 2c. 1 is comprised by the recessed part 2d for mounting | wearing with a sealing material, when it arrange | positions inside piping etc. of a water heater.

  The guide 3 includes a flange portion 3 a attached to the left circular opening of the case 2, a guide hole 3 b for guiding the base portion 4 a of the valve shaft 4, a recess 3 c for receiving the left end portion of the coil spring 6, and the guide 3. And a plurality of fluid passages 3d penetrating in the left-right direction. Here, in order to surely press the valve body 5 against the valve seat 2b of the case 2, the length L1 of the guide hole 3b of the guide 3 is set to ½ or more of the sliding length L2 of the valve shaft 4. For the same purpose, the inner surface of the guide hole 3b is formed so as to protrude from both end surfaces of the guide hole 3b, that is, the inner diameter on the center side is smaller than both end surfaces. Further, the clearance between the base 4a and the guide hole 3b is adjusted so that the base 4a of the valve shaft 4 can smoothly slide in the guide hole 3b of the guide 3 without being caught.

  The valve shaft 4 includes a rod-like base portion 4a, a disk-like flange portion 4b, and a hemispherical portion 4c located at the right end of the base portion 4a. A valve body 5 is mounted between the flange portion 4b and the hemispherical portion 4c, and the flange portion 4b is urged toward the valve seat 2b side of the case 2 by the coil spring 6. In this example, the base 4a is cylindrical.

  The valve body 5 is formed in a disc shape as a whole by a general-purpose rubber material having durability with hot water, and an outer peripheral portion 5a contacting and separating from the valve seat 2b, and a disc-shaped center thicker than the outer peripheral portion 5a. Part 5b, and the left side surface of the central part 5b contacts the right side surface of the flange part 4b of the valve shaft 4. Here, the general-purpose rubber material having hot water durability can be, for example, a general-purpose material of hot water FKM (highly durable hot water FKM material), and the rubber hardness thereof is about 70 Hs.

  That is, in the conventional check valve, a rubber material having a low hardness (rubber hardness of about 60 Hs) is used as a valve body, whereas in this embodiment, by using a harder general-purpose material, Durability is improved.

  The coil spring 6 is disposed between the concave portion 3c of the guide 3 and the flange portion 4b of the valve shaft 4, and biases the flange portion 4b of the valve shaft 4 in the direction of the valve seat 2b of the case 2, thereby The outer peripheral portion 5a of the body 5 is pressed against the valve seat 2b.

  In the state shown in FIG. 1, the check valve 1 having the above configuration urges the flange portion 4 b of the valve shaft 4 to the right by the coil spring 6, thereby pressing the valve body 5 against the valve seat 2 b of the case 2. Even if the pressure of the valve chamber 2e inside the case 2 increases, the fluid inside the valve chamber 2e is opened by the contact between the valve seat 2b of the case 2 and the outer peripheral portion 5a of the valve body 5. To flow to the right after passing through.

  On the other hand, when the pressure of the fluid in the right space 2f of the case 2 is higher than that of the valve chamber 2e, the outer peripheral portion 5a of the valve body 5 is separated from the valve seat 2b as shown in FIG. Fluid flows to the left. When the pressure of the fluid in the right space 2f is further increased than the valve chamber 2e and a force larger than the elastic force of the coil spring 6 is applied to the valve shaft 4 via the valve body 5, the base portion 4a of the valve shaft 4 is guided by the guide 3 The entire valve shaft 4 moves to the left while being guided by the guide hole 3b, and the distance between the valve seat 2b and the outer peripheral portion 5a is further increased, so that more fluid flows.

  Next, a test example of the check valve 1 will be described with reference to FIG.

  As shown in FIG. 1, the plate thickness of the outer peripheral portion 5a of the valve body 5 is t [mm], the outer diameter of the central portion 5b is D1 [mm], and the opening diameter of the valve seat 2b of the case 2 is D2 [mm]. The seal length L is defined as L = (D2−D1) / 2.

  The check valve 1 used for the test is incorporated in a pipe having a bore (inner diameter) of 20 mm (that is, the outer diameter of the check valve 1 is slightly smaller than 20 mm). The distance from the portion 4b is about 1 mm, the outer diameter D3 of the valve body 5 is 13 mm, the opening diameter D2 of the valve seat is 12 mm, and the material of the valve body 5 is the FKM material for hot water having a rubber hardness of 70 Hs as described above (general-purpose Material).

The seal length L and the plate thickness t of the outer peripheral portion 5a of the valve body 5 are changed, and a plurality of relatively weak predetermined pressures are applied to the valve chamber 2e of the case 2 so that the valve body 5 and the valve seat 2b The case where the amount of fluid leakage during the period was 0.5 cm ³ / min or less was plotted in FIG. In the figure, a case where a plurality of kinds of pressures having a Δ mark of 1.0 kPa or less is applied, and a case where a plurality of kinds of pressures having a □ mark exceeding 1.0 kPa are applied.

From the same figure, when t ≦ 0.4L−0.04, when a pressure of 1.0 kPa or less is applied, the amount of fluid leakage between the valve body 5 and the valve seat 2b is 0.5 cm ³ / It can be seen that the amount of leakage can be suppressed to a predetermined value or less when the pressure at which the fluid present in the valve chamber 2e presses the valve body 5 toward the valve seat 2b is weak.

Next, the seal length L and the plate thickness t of the outer peripheral portion 5a of the valve body 5 are changed, and a plurality of relatively strong predetermined pressures are applied to the valve chamber 2e of the case 2 to thereby apply the valve body 5 and the valve seat. The case where the amount of fluid leakage between 2b is 0.5 cm ³ / min or less is plotted in FIG. In the figure, a case where a plurality of types of pressures in which * is less than 0.6 MPa is applied, and a case where a plurality of types of pressures in which a circle is 0.6 MPa or more and 3.5 MPa or less is applied.

From the same figure, when t ≧ 0.8, when a pressure of 0.6 MPa or more and 3.5 MPa or less is applied, the amount of fluid leakage between the valve body 5 and the valve seat 2b is 0.5 cm ^3. / Min or less, and it can be seen that the amount of leakage can be suppressed to a predetermined value or less when the pressure in which the fluid existing in the valve chamber 2e presses the valve body 5 toward the valve seat 2b is strong.

  In the above embodiment, the valve body 5 is provided with the outer peripheral portion 5a and the disk-shaped central portion 5b thicker than the outer peripheral portion 5a, and the central portion 5b is formed from both surfaces of the outer peripheral portion 5a. As shown in FIG. 4, the valve body 15 is used instead of the valve body 5, and the central portion 15b of the valve body 15 is configured to protrude from one surface of the outer peripheral portion 15a. May be. Even in this configuration, a gap is formed between the flange portion 4 b of the valve shaft 4 and the outer peripheral portion 15 a of the valve body 15, and the same effect as in the case of using the valve body 5 is achieved.

  Now, the embodiment of the check valve 1 attached to the pipe having a diameter of 20 mm has been described above. However, the present invention is not limited to the check valve having this diameter, and the seal length L and the plate shown in FIG. Of course, as long as the relationship of the thickness t is satisfied, it may be applied to pipes having a diameter other than 20 mm.

  For example, in a check valve incorporated in a pipe having a diameter of 12 mm or more and 22 mm or less, the outer diameter D3 of the valve body may be 9 to 15 mm and the opening diameter D2 of the valve seat may be 8 to 14 mm.

  The relationship between the base 4a of the valve shaft 4 of the check valve 1 and the guide hole 3b of the guide 3 can be variously employed as shown in FIGS. These drawings correspond to the AA cross section of FIG. 1, and illustration of components other than the valve shaft 4 and the guide 3 is omitted.

  Fig.5 (a) shows the base 4a of the valve shaft 4 and the guide hole 3b of the guide 3 in the said test example, FIG.5 (b)-(e) shows another structural example. In these, the base portion 4a of the valve shaft 4 is configured to be able to slide smoothly in the guide hole 3b of the guide 3, and between the base portion 4a and the guide hole 3b, the axial direction of the base portion 4a (the valve shaft 4 The through passages 4d to 4g penetrating in the axial direction) are formed, and even if foreign matter enters between the base portion 4a and the guide hole 3b, it can be easily escaped, and the sliding failure of the base portion 4a in the guide hole 3b can be prevented. This is preferable because it can be prevented.

  In the example of FIG. 5B, a groove having a rectangular cross section is formed in the base portion 4a of the valve shaft 4 in the axial direction, so that a through-passage having a rectangular cross section is formed between the groove and the guide hole 3b. 4d is formed.

  In the example of FIG. 5C, the base portion 4a is configured to have a triangular cross section, so that three through passages 4e are formed between the base portion 4a and the guide hole 3b.

  In the example of FIG. 4D, the base portion 4a is formed in a cross-shaped cross section, so that four through passages 4f are formed between the base portion 4a and the guide hole 3b.

  In the example shown in FIG. 6E, the guide hole 3b is configured to have a hexagonal cross section, so that six through passages 4g are formed between the columnar base 4a and the guide hole 3b.

  In any case, the foreign matter mixed in the fluid passing through the check valve is discharged downstream through the through passages 4d to 4g.

  In any case, the inner surface of the guide hole 3b may be formed so as to protrude from both end faces of the guide hole 3b, that is, the inner diameter on the center side is smaller than both end faces.

DESCRIPTION OF SYMBOLS 1 Check valve 2 Case 2a Base 2b Valve seat 2c Flange 2d Recess 2e Valve chamber 2f Right space 3 Guide 3a Flange 3b Guide hole 3c Recess 3d Fluid passage 4 Valve shaft 4a Base 4b Flange 4c Hemispherical part 4d 4g Through-passage 5 Valve body 5a Outer peripheral part 5b Central part 6 Coil spring 15 Valve body 15a Outer peripheral part 15b Central part

Claims (12)

A check valve incorporated in a pipe having a diameter of 12 mm or more and 22 mm or less,
A cylindrical body having a valve seat;
A valve shaft slidably disposed on the main body and provided with a flange portion;
A general-purpose rubber material with durability against hot water is formed in a disc shape as a whole, and includes an outer peripheral portion that contacts and separates from the valve seat, and a disc-shaped central portion that is thicker than the outer peripheral portion. A valve body that abuts against the flange portion of the valve shaft;
A coil spring that presses the flange portion of the valve shaft toward the valve seat,
The amount of fluid leakage between the valve body and the valve seat is small in both cases where the pressure of the fluid existing inside the pipe pressing the valve body toward the valve seat is weak and strong. In a check valve that is 0.5 cm ³ / min or less,
The plate thickness of the outer peripheral portion of the valve body is t [mm], the outer diameter of the central portion of the valve body is D1 [mm], the opening diameter of the valve seat is D2 [mm], the seal length L, When L = (D2−D1) / 2,
A check valve characterized by satisfying t ≦ 0.4L−0.04 and t ≧ 0.8.   2. The check valve according to claim 1, wherein the pressure is 1.0 kPa or less when the pressure that presses the valve body toward the valve seat by the fluid existing in the pipe is weak.   3. The pressure according to claim 1, wherein the pressure when the pressure for pressing the valve body toward the valve seat is high by a fluid present in the pipe is 0.6 MPa or more and 3.5 MPa or less. Check valve.   The check valve according to claim 1, wherein the general-purpose rubber material has a rubber hardness of 70 Hs.   The check valve according to any one of claims 1 to 4, wherein the general-purpose rubber material is a general-purpose material of a hot water FKM material.   The check valve according to any one of claims 1 to 5, wherein a distance between opposite surfaces of the flange portion of the valve shaft and the outer peripheral portion of the valve body is 1 mm or less.   The check valve according to any one of claims 1 to 6, wherein an outer diameter D3 of the valve body is 9 to 15 mm.   The check valve according to any one of claims 1 to 7, wherein an opening diameter D2 of the valve seat is 8 to 14 mm.   The check valve according to any one of claims 1 to 8, wherein the seal length L is 2.1 mm or more.   The check valve according to any one of claims 1 to 9, wherein the valve shaft includes a rod-like base portion, and the base portion is slidably disposed in a guide hole provided in the main body.   11. The check valve according to claim 10, wherein the inner surface of the guide hole is formed such that the inner diameter of the guide hole is smaller than both end surfaces of the guide hole.   The check valve according to claim 10 or 11, wherein a through passage penetrating in the axial direction is formed between the guide hole and the base portion.

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