Check valve device

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a check valve device suitable for use in a faucet.

【0002】

[Conventional technology]

Conventionally, a check valve device is provided in the faucet to prevent backflow of water or hot water (hereinafter, simply referred to as water) from the faucet to the water supply source side or to the hot water supply source side. FIG. 8 shows an example of the check valve device. In FIG. 8, 200 is a supply pipe that is arranged under the faucet mounting body such as a counter and supplies water or hot water to the faucet main body installed on the mounting body, and has a water passage 202 inside. doing. A check valve device 204 is provided on the water passage 202 to allow only the flow of water from the water supply source toward the faucet main body side and prevent the flow in the reverse direction.

【0003】

The check valve device 204 has a holding sleeve 206, which is screwed to a cylindrical housing 212 integrally formed with the tubular body 210 via a bottomed cylindrical cap 208. And fixed.

【0004】

The check valve device 204 has a check valve body 214 arranged inside the holding sleeve 206 and a valve rod 216 integrally formed with the check valve body 214, and the check valve rod 216 has the valve rod 216. , The guide portion 218 fixedly provided on the holding sleeve 206 side is slidably fitted to guide the movement. The holding sleeve 206 is also provided with a valve seat 220 on one end side, and the check valve body 214 is urged by a spring member 222 in a direction of contact with the valve seat 220.

【0005】

As described above, when installing a faucet, a check valve device is usually provided on the water passage to prevent backflow. On the other hand, by providing a check valve device in this way, water is provided when the faucet is closed. There is a problem that the hammer is easily evoked.

【0006】

When the faucet is closed while the faucet is opened and spouting water vigorously, the check valve device immediately operates to seal the downstream part of the water passage, that is, the part downstream from the check valve device. Therefore, a sudden high pressure is generated in the same part to cause a water hammer. In particular, when the faucet is a single-lever type faucet, the water hammer is likely to occur because the faucet can be operated suddenly and the faucet can be closed suddenly.

【0007】

In addition to the occurrence of such a water hammer, the arrangement of the check valve device has conventionally caused the following problems. That is, when only hot water is continuously flowed in the hot water mixing faucet, the water is heated in the closed system and expands in the water passage on the water side, and the expansion pressure causes leakage from the faucet seal or the like, or the seal. There was a problem that the part was damaged.

【0008】

Therefore, in order to prevent this, conventionally, a water hammer preventer having an independent form is provided on the water passage together with the check valve device. However, when the water hammer preventer having an independent form is provided in this way, there is a problem that the cost increases, and there is a problem that the man-hours for assembling the water hammer preventer increase.

【0009】

Therefore, the check valve device is also provided with a water hammer prevention function. FIG. 9 shows an example of a check valve device equipped with the water hammer prevention function. In the figure, 224 is a check valve device provided on the supply pipe 200, and 226 is a cylindrical housing integrally formed with the pipe body. The housing 226 is formed by screwing the divided bodies 226A and 226B together.

【0010】

228 is a sleeve that also serves as a pressure relief valve body, and the direction in which the upper end portion of the second spring member 234 abuts on the valve seat portion (second valve seat portion) 232 integrally formed with the housing 226 via the seal member 230. Is being urged to. Inside the sleeve 228, a check valve body 236 and a valve rod 238 integrally formed with the check valve body 236 are arranged, and the check valve body 236 is formed by the first spring member 240 to form the sleeve 228. It is urged in the direction of contact with the valve seat portion (first valve seat portion) 242 formed in. The valve stem 238 is slidably fitted to the guide portion 244, which is formed separately from the sleeve 228 and the housing 226, to guide the movement.

【0011】

In the case of this check valve device 224 with a water hammer prevention function, the check valve body 236 is normally opened by the flow of water in the direction of the arrow (forward direction) to allow the flow of water, but with respect to the flow in the reverse direction. The check valve body 236 abuts and sits on the valve seat portion 242 to prevent the flow in the reverse direction.

【0012】

When the pressure on the downstream side of the check valve device 224 increases, the sleeve 228, which also serves as the pressure relief valve body, slides downward in the figure to move the pressure of the sealed system water, that is, the check valve device 224. It releases the pressure of water on the downstream side and prevents water hammer. At the same time, even when the water in the closed system expands and the pressure rises, it acts to release the pressure.

【0013】

[Problems to be Solved by the Invention]

However, in the case of this check valve device 224 with a water hammer prevention function, the housing 226 must be divided because it is necessary to incorporate the sleeve 228, which also serves as a pressure relief valve body, into the housing 226 so that it can be slidably moved. In addition to this, the check valve device 224 itself inevitably becomes large in size, resulting in an increase in cost, and there is a problem that the check valve device cannot be assembled as it is to the assembly part of the existing faucet or the like. ..

【0014】

In addition, in the case of the check valve device 224, the sleeve 228 faces inward to the housing 226 when the sleeve 228 opens vigorously, that is, when the pressure relief valve body composed of the sleeve 228 opens vigorously. There was a problem that the water hammer was not always surely prevented due to the water hammer stopping operation due to the contact with the spring receiving portion 246 formed in a protruding shape.

【0015】

[Means for solving problems]

The invention of the present application has been made to solve such a problem. Thus, the check valve device of the present invention is provided on the water passage, and substantially allows only the forward flow of water from the upstream side to the downstream side of the water passage, and blocks the reverse flow. A check valve device that (a) holds a holding sleeve that has a flow path that forms part of the water passage inside, and (b) a first valve that is formed on the inner surface side of the holding sleeve and on the flow path. While the seat and (c) are disposed inside the holding sleeve and held by the holding sleeve and separated from the first valve seat in a direction that allows the forward flow of water in the flow path, A check valve body that abuts on the first valve seat portion in a direction that blocks the flow in the reverse direction, and (d) urges the check valve body in a direction that abuts the first valve seat portion. A spring member, (e) a pressure relief passage formed through the check valve body in a state of communicating the upstream side and the downstream side of the check valve body in the water passage, and (f) the said. A second valve seat provided on the pressure relief passage of the check valve body and (g) assembled to the check valve body from the downstream side to the upstream side of the check valve body in the water passage. A pressure relief valve body that separates from the second valve seat portion in a direction that allows water leakage, and abuts against the second valve seat portion in a direction that prevents water leakage from the upstream side to the downstream side. (H) The second spring member is urged by a predetermined spring force in the direction in which the pressure relief valve body is brought into contact with the second valve seat portion (claim 1).

【0016】

In claim 1, the check valve device of another invention of the present application is the pressure relief valve in a state in which the valve rods for common movement guidance of the check valve body and the pressure relief valve body extend in the axial direction thereof. The valve rod is integrally formed on the side of the body, and the valve rod is slidably fitted to a guide portion provided at a fixed position (claim 2).

【0017】

The check valve device of still another invention of the present application is characterized in that, in claim 2, the guide portion is fixedly provided on the holding sleeve (claim 3).

【0018】

In claim 1, 2 or 3, the check valve device of still another invention of the present application has the upstream portion of the holding sleeve following the first valve seat portion in the axial direction of the check valve body. While it is formed as a parallel mating surface, the upstream portion of the check valve body following the contact portion with the first valve seat portion has a predetermined length in the direction parallel to the mating surface. It is characterized in that it extends and is formed as a fitting surface that extends and fits with the fitted surface in a minute gap when the valve is closed (claim 4).

【0019】

In a check valve device of still another invention of the present application, in claim 1, 2, 3 or 4, the second spring member is attached to the pressure relief valve body at one end and the check valve body at the other end. The pressure relief valve body side has a small diameter, the check valve body side has a large diameter, and the diameter gradually increases from the small diameter side to the large diameter side. Further, the spring receiving portion is formed radially outside the pressure relief valve body (claim 5).

【0020】

[Action and Effect of Invention]

As described above, the invention of claim 1 is a pressure relief valve body in which a pressure relief passage is formed in the check valve body arranged and held inside the sleeve in the check valve device, and the pressure relief passage is opened and closed. Is incorporated, and this is urged in a direction in which it is brought into contact with the second valve seat portion from the second spring member.

【0021】

That is, when the pressure in the portion downstream of the check valve device in the water passage rises above a certain pressure, the pressure relief valve body is opened based on the pressure to release the pressure trapped inside. According to the present invention, the generation of a water hammer can be satisfactorily suppressed based on the action of the pressure relief valve body, or the water sealed in the portion downstream of the check valve device is heated and expanded. At that time, the expansion pressure can be satisfactorily released, and damage to the seal portion or the like can be satisfactorily prevented based on the pressure increase.

【0022】

In the device of the present invention, the sleeve itself does not constitute a pressure relief valve body unlike the check valve device shown in FIG. 9, but a pressure relief passage, a pressure relief valve body, etc. are provided in the check valve body inside the sleeve. It is provided. Therefore, according to the present invention, the check valve device can be compactly configured, and the check valve device can be directly assembled to the existing assembly portion.

【0023】

According to the second aspect of the present invention, a valve rod for movement guidance common to the check valve body and the pressure relief valve body is provided, and the valve rod is slidably fitted to the guide portion in the fixed position state. According to the present invention, the check valve body can be smoothly moved and guided together with the pressure relief valve body based on the action of the valve rod and the guide portion, and the pressure relief valve body itself can be used as the check valve body. On the other hand, the relative movement can be smoothly performed. Further, according to the present invention, since only one valve stem is required, there is an advantage that the structure of the device is simple and compact.

【0024】

According to the third aspect of the present invention, the guide portion is fixedly provided on the sleeve, and according to the present invention, the structure of the check valve device is simplified and the check valve device can be easily assembled. Become.

【0025】

In the invention of claim 4, the portion of the holding sleeve on the upstream side following the first valve seat portion is formed as a fitted surface, and the corresponding portion of the check valve body is formed as a fitting surface, and these are formed when the valve is closed. It is formed so as to be fitted with a minute gap over a predetermined length in the axial direction, and according to the present invention, the fitting surface and the fitted surface that were separated when the check valve body was opened Gives resistance to the valve closing operation of the check valve body when mating at the time of valve closing, so that the check valve body operates slowly and slowly, and the check valve body suddenly closes the valve. The advantage is that the motion-based water hammer is effectively suppressed.

【0026】

The invention of claim 5 has a shape in which the diameter of the second spring member for urging the pressure relief valve body gradually increases from the small diameter portion on the pressure relief valve body side to the large diameter portion on the check valve body side. The check valve body is provided with a spring receiving portion that receives an end portion on the larger diameter side in the radial direction outside the pressure relief valve body. According to the present invention, the valve opening operation of the pressure relief valve body is provided. Occasionally, the pressure relief valve body does not come into contact with this spring receiving part to stop water, so it is good to prevent the occurrence of water hammers and to release increased pressure in the part downstream of the check valve device. It can be performed.

【0027】

[Example]

Next, examples of the present invention will be described in detail with reference to the drawings. In FIG. 2, 10 shows a single lever type mixing faucet installed on the counter 12 of the kitchen as an example of the faucet, and has a lever 14 as an operation unit, and the rotation of the lever 14 Hot water or water or a mixture thereof is discharged from the spout 16 based on the operation.

【0028】

From the main body of the faucet 10, as shown in FIG. 3, a pair for supplying hot water or water (hereinafter simply referred to as water except in special cases) to the faucet main body under the counter 12. The supply pipes 18 of the above are extended, and the check valve device 20 with the water hammer prevention function of this example is provided on the supply pipes 18.

【0029】

FIG. 1 shows the specific structure of the check valve device 20. In the figure, reference numeral 22 denotes a cylindrical holding sleeve, which has a male screw on the outer peripheral surface of one end in the axial direction, and is screwed into the female screw on the inner peripheral surface of the cap 24 having a bottomed cylindrical shape. The cap 24 also has a male screw on the outer peripheral surface, and the male screw is screwed into the female screw on the inner peripheral surface of the cylindrical housing 28 integrally formed with the tubular body 26. That is, the holding sleeve 22 is screwed to and fixed to the housing 28 via the cap 24. The holding sleeve 22 is formed with a through hole 23 for communicating the inside and the outside.

【0030】

A check valve body 30 is arranged inside the holding sleeve 22, and the check valve body 30 hits the first valve seat portion 34 formed at the end of the holding sleeve 22 via the seal member 32. It is designed to be touched. The check valve body 30 is oriented in a direction that allows a forward flow of water in the water passage 15, that is, an upward flow from the lower side in the figure toward the faucet body, and blocks the flow in the opposite direction. ing. A valve rod 36, which is a separate body from the check valve body 30, extends to the left in the drawing, and a flanged cylindrical spring receiving member 38 is fixed to the tip of the valve rod 36.

【0031】

On the other hand, inside the holding sleeve 22, a flanged cylindrical guide member (guide portion) 40 is fixedly provided by a retaining ring 42 at a position separated from the spring receiving member 38 by a predetermined distance in the axial direction. A first spring member 44 made of a compression coil spring is interposed between the spring receiving member 38 and the guide member 40 in a precompressed state.

【0032】

That is, the urging force of the first spring member 44 is exerted on the check valve body 30 via the valve rod 36 and the second spring member 46 described later in a direction in which the check valve body 30 is brought into contact with the first valve seat portion 34. ing. The valve stem 36 is slidably fitted to the inner peripheral surface of the guide member 40, and is moved and guided in the axial direction by the guide member 40. Here, the flange portion of the guide member 40 is formed with a communication hole 48 for communicating the upstream side and the downstream side portions thereof.

【0033】

The check valve body 30 is formed with a penetrating pressure relief passage 50 that communicates the upstream side and the downstream side thereof. On the other hand, a disk-shaped pressure relief valve body 52 is integrally formed in the vicinity of the end portion of the valve rod 36, and the pressure relief valve body 52 is formed in the check valve body 30 via the seal member 56. It is designed to be brought into contact with the second valve seat portion 54. That is, the pressure relief passage 50 is opened and closed when the pressure relief valve body 52 comes into contact with or separates from the second valve seat portion 54. Here, the pressure relief valve body 52 is oriented in a direction that allows water to leak from the downstream side to the upstream side and prevents leakage in the opposite direction.

【0034】

One end of a second spring member 46 made of a compression coil spring is brought into contact with the back surface of the pressure relief valve body 52. The second spring member 46 has a tubular shape and a tapered shape as a whole, and the end on the small diameter side is the pressure relief valve body 52, and the end on the large diameter side is the radial direction of the pressure relief valve body 52. On the outside, it is brought into contact with the spring receiving portion 58 formed on the check valve body 30, and its urging force is applied to the pressure relief valve body 52 in a direction in which it is brought into contact with the second valve seat portion 54. ing.

【0035】

As shown in the partially enlarged view of FIG. 1, the portion of the holding sleeve 22 on the upstream side following the first valve seat portion 34 is covered with a cover extending in a predetermined length in a direction parallel to the axis of the check valve body 30. A fitting surface 60 is formed. On the other hand, also in the check valve body 30, a fitting surface 62 extending in a direction parallel to the axis thereof is formed with a predetermined length in a portion on the upstream side following the contact portion with the first valve seat portion 34. The fitting surface 62 is adapted to be fitted to the fitted surface 60 when the check valve body 30 is closed.

【0036】

In the case of the check valve device 20 of this example, when the water in the water passage 15 flows in the direction of the arrow in the figure, that is, when it flows in the forward direction from the water supply source toward the faucet body, it is shown in FIG. 4 (A). The check valve body 30 is separated from the first valve seat portion 34 to open the water passage 15 so as to allow flow in the same direction. On the other hand, with respect to the flow in the opposite direction, as shown in FIG. 4 (B), the check valve body 30 abuts and sits on the first valve seat portion 34 to block the water passage 15 and reverse the direction. Block the flow of. Therefore, when the lever 14 of the faucet 10 is operated to open the valve inside the faucet, the water in the water passage 15 is immediately discharged from the tip of the spout 16 via the passage inside the faucet body.

【0037】

On the other hand, when the lever 14 is operated to stop the water discharge and the valve inside the faucet body is suddenly closed, the check valve body 30 momentarily closes. As a result, the portion downstream of the check valve device 20 becomes sealed and the pressure tends to rise momentarily.

【0038】

However, in the case of the check valve device 20 of this example, when a pressure rise occurs in a portion downstream of this and the pressure reaches a constant pressure, that is, a certain amount or more is provided between the downstream portion and the upstream portion. When a differential pressure of the magnitude of is generated, the pressure relief valve body 52 operates based on the differential pressure as shown in FIG. 5 (in this example, the differential pressure is 3 kgf / cm).²The spring force of the second spring member 46 is set so that the pressure relief valve body 52 opens the valve when the above occurs), and acts to release the pressure trapped in the downstream portion. As a result, it is possible to prevent a large sudden pressure rise from occurring in the portion downstream of the check valve device 20, and thus the generation of a water hammer due to the sudden pressure rise is prevented.

【0039】

In the hot water mixing faucet 10 of this example, when only the hot water side passage is opened with the water side passage inside the faucet body blocked, that is, when only hot water is continuously discharged from the spout 16, water The temperature of the main body of the tap rises due to the heating action of the hot water, and at the same time, the water trapped in the portion downstream of the check valve device 20 in the water passage on the water side heats and expands, and an expansion pressure is generated there.

【0040】

In the check valve device 20 of this example, the pressure relief valve body 52 also operates to open the valve to release the increased pressure, and a high pressure is applied to the downstream portion of the check valve device 20. Prevents becoming muffled. Therefore, due to the pressure increase generated in the downstream portion of the check valve device 20, leakage from the seal portion and damage to the seal portion in the faucet 10 are satisfactorily avoided.

【0041】

In the check valve device 20 of this example, a check valve body 30 arranged and held inside the holding sleeve 22 is provided with a pressure relief passage 50, and the check valve body 30 is provided with a pressure relief valve body 52. According to this example, the check valve device 20 can be compactly configured, and the check valve device 20 can be directly assembled to the existing assembly portion.

【0042】

Further, in the device of this example, a valve rod 36 common to the check valve body 30 and the pressure relief valve body 52 is provided so as to be slidably fitted to the position-fixed guide member 40 to guide the movement. According to this example, when the check valve body 30 and the pressure relief valve body 52 are integrally opened and closed, the pressure relief valve body 52 is independently opened and closed. Even when the valve is operated, the valve opening and closing operations can be smoothly performed. In addition, according to this example, since only one valve rod 36 for movement guidance is required, there is an advantage that the structure of the device is simple and compact.

【0043】

Further, in this example, since the guide member 40 is fixedly provided on the holding sleeve 22, it is not necessary to separately assemble the guide member separately from the holding sleeve 22 when assembling the check valve device 20. The structure of the check valve device 20 is simplified and the assembly work is facilitated.

【0044】

Further, in the case of the check valve device 20 of this example, the fitting surface 62 formed on the check valve body 30 is fitted to the fitted surface 60 formed on the holding sleeve 22 when the check valve body 30 is closed. However, since valve closing resistance to the check valve body 30 is generated at that time, the check valve body 30 operates the valve closing slowly and slowly, which has an advantage that the generation of water hammer is prevented more effectively. There is.

【0045】

Others In the case of the check valve device 20 of this example, the spring receiving portion 58 for receiving the end portion on the large diameter side of the second spring member 46 for urging the pressure relief valve body 52 is larger than the pressure relief valve body 52. Since it is formed on the outer side in the radial direction, there is no problem that the pressure relief valve body 52 hits the spring receiving portion 58 and stops the water during the valve opening operation of the pressure relief valve body 52, and therefore the pressure relief valve does not occur. Even when the body 52 vigorously opens the valve, the water stop operation based on the contact with the spring receiving portion 58 can be reliably avoided, and thus the occurrence of the water hammer can be reliably prevented.

【0046】

FIG. 6 shows another embodiment of the present invention. The hot water mixing faucet 64 in this example is wall-mounted and includes a faucet main body 66, a spout 68, and a pair of legs 70 that also serve as water supply and hot water supply pipes. A check valve device 72 is incorporated in the connecting portion between the foot 70 and the leg 70.

【0047】

As shown in the enlarged view of FIG. 6, the check valve device 72 of this example is fitted to the inner surface of the housing 74 by screwing the bag nut 76 into the cylindrical housing 74 formed in the faucet body 66. It is incorporated in a state of being in contact with the contact portion 78.

【0048】

FIG. 7 shows the specific structure of the check valve device 72. In the figure, reference numeral 80 denotes a cylindrical holding sleeve, in which a check valve body 81 is arranged, and the check valve body 81 is formed at an end of the holding sleeve 80 via a sealing member 82. It is designed to be brought into contact with the first valve seat portion 84. The holding sleeve 80 is formed with a through hole 85 for communicating the inside and the outside.

【0049】

Here, the check valve body 81 abuts upward on the first valve seat portion 84 from the lower side in the drawing, that is, abuts on the first valve seat portion 84 in the direction from the inside to the outside of the holding sleeve 80. It blocks the flow in the opposite direction in the waterway.

【0050】

The check valve body 81 is provided with a penetrating pressure relief passage 86 for communicating the upstream side and the downstream side thereof, and a second valve seat portion 88. The pressure relief valve body 90 abuts or separates from the second valve seat portion 88 via the seal member 92, so that the pressure relief passage 86 is opened and closed. As is clear from FIG. 7, in this example, the pressure relief valve body 90 is brought into contact with the second valve seat portion 88 from the lower side in the figure upward via the seal member 92, and in the opposite direction, the pressure relief valve body 90 is brought into contact with the second valve seat portion 88. It is designed to be separated from the two valve seat portion 88.

【0051】

A valve rod 94 extends downward in the drawing from the pressure relief valve body 90, and the valve rod 94 slides on the inner peripheral surface of a cylindrical guide portion 96 fixedly provided on the holding sleeve 80. It is movably fitted and is designed to be moved and guided.

【0052】

The end of the first spring member 98 made of a compression coil spring is brought into contact with the back surface of the check valve body 81, and the urging force of the first spring member 98 is applied to the check valve body 81. ing. In this example, the urging force of the first spring member 98 is directly exerted on the check valve body 81 in the direction of bringing it into contact with the first valve seat portion 84.

【0053】

On the other hand, the urging force of the second spring member 100 made of the compression coil spring is exerted on the pressure relief valve body 90 in the opposite direction to that of the first spring member 98. That is, the urging force of the second spring member 100 is exerted in the direction in which the pressure relief valve body 90 comes into contact with the second valve seat portion 88.

【0054】

Here, the second spring member 100 has a tubular shape and a tapered shape as a whole, the end portion on the small diameter side is brought into contact with the pressure relief valve body 90, and the end portion on the large diameter side is a check valve. It is in contact with the spring receiving portion 102 formed on the body 81. The spring receiving portion 102 is formed on the radial outer side of the pressure relief valve body 90 so that the spring receiving portion 102 does not hit the pressure relief valve body 90 when the pressure relief valve body 90 is opened. Has been done.

【0055】

In the case of the check valve device 72 of this example, when the faucet 64 is used, the check valve body 81 moves downward in the figure, that is, moves away from the first valve seat portion 84 to open the water passage. On the other hand, when the valve of the faucet 64 is closed, the check valve body 81 comes into contact with the first valve seat portion 84 based on the urging force of the first spring member 98, and shuts off the water passage.

【0056】

At that time, when the pressure on the downstream side of the check valve device 72 rises and reaches a constant pressure, the pressure relief valve body 90 separates from the second valve seat portion 88 and opens the pressure relief passage 86 on the downstream side. Relieve the pressure in the part. In this example as well, the differential pressure between the downstream part and the upstream side of the check valve device 72 is 3 kgf / cm.²The spring force of the second spring member 100 is determined so that the pressure relief valve body 90 opens the valve when the above is achieved.

【0057】

The check valve device 72 of this example can also be configured compactly as the check valve device 20 of the first embodiment, and also has a check valve in the conventional check valve device. The check valve device 72 of this example can be configured by assembling the check valve body 81 with a pressure relief mechanism as it is instead of the body.

【0058】

Furthermore, based on the action of the valve rod 94 and the guide portion 96 for movement guidance, the check valve body 81 and the pressure relief valve body 90 can be integrally and smoothly operated to open and close the valve, and the pressure relief valve can be operated smoothly. It is possible to smoothly perform the valve opening / closing operation of the body 90. In addition, based on the fitting action of the fitted surface 60 formed on the holding sleeve 80 and the fitting surface 62 formed on the check valve body 81, this is slowly performed during the valve closing operation of the check valve body 81. It has the same advantages as in the first embodiment, such as being able to suppress the occurrence of water hammer.

【0059】

Although the examples of the present invention have been described in detail above, this is merely an example, and the present invention can be applied to a check valve device in various forms of faucets other than the above examples. It can be configured in a form with various changes within a range that does not deviate.

[Simple explanation of drawings]

[Figure 1]

It is a figure which shows the check valve device which is one Example of this invention together with the main part of the supply pipe for supply of water or hot water to a faucet.

[Figure 2]

It is a figure which shows the kitchen faucet which receives hot water or water supply by the supply pipe of FIG. 1 in the installed state.

[Fig. 3]

It is a figure which shows the supply path of water or hot water to the kitchen faucet of FIG. 2 and the arrangement position of the check valve device of FIG.

[Fig. 4]

It is explanatory drawing of the operation at the time of the backflow prevention in the check valve device of FIG.

[Fig. 5]

It is explanatory drawing of the operation at the time of water hammer prevention in the check valve device of FIG.

[Fig. 6]

It is a figure which shows the check valve device which is another Example of this invention together with a wall-mounted hot water mixing faucet.

[Fig. 7]

FIG. 6 is an enlarged view showing the structure of the check valve device of FIG.

[Fig. 8]

It is a figure which shows the conventional check valve device together with the main part of a supply pipe.

[Fig. 9]

It is a figure which shows the example different from FIG. 8 of the conventional check valve device.

[Explanation of symbols]

15 waterways 20,72 Check valve device 22,80 Retaining sleeve 30,81 Check valve 34,84 First valve seat 36,94 Valve bar 40 Guide member 44,98 First spring member 46,100 Second spring member 50,86 Pressure relief passage 52,90 Pressure relief valve 54,88 Second valve seat 58,102 Spring receiver 60 Fitted surface 62 Fitting surface 96 Guide section