JP5768238B2 - Check valve and compound valve - Google Patents

Description

  The present invention relates to a check valve for preventing a backflow of a working fluid from a secondary pressure side to a primary pressure side, and a mixing valve including the check valve.

  In recent years, hot water storage type hot water supply apparatuses are becoming widespread for reasons such as being environmentally friendly and keeping utility costs relatively low. This hot water storage type hot water supply device, for example, pumps heat in the atmosphere by a heat pump system using carbon dioxide, which is a natural refrigerant, and uses it as heat energy necessary for hot water supply. It is used in a heat pump unit as a heat source and a hot water storage tank. (For example, refer to Patent Document 1).

  A water supply pipe is connected to the lower part of the hot water storage tank, and low temperature water is supplied from the water supply. This low-temperature water is sent to the heat pump unit for heat exchange and returned to the upper part of the hot water storage tank as hot water. As a result, in the hot water storage tank, a temperature stratification is formed in which high temperature hot water (high temperature water) is present in the upper portion, intermediate temperature hot water (medium temperature water) is present in the middle portion, and low temperature hot water (low temperature water) is present in the lower portion. A hot water supply pipe is connected to the high temperature layer of the hot water storage tank, and merges with the water supply pipe on the downstream side. A mixing valve is provided at the junction of the hot water supply pipe and the water supply pipe, and the temperature of the hot water flowing downstream is adjusted by adjusting the mixing ratio of the high temperature water flowing through the hot water supply pipe and the low temperature water flowing through the water supply pipe. In such a configuration, a check valve is often provided on the upstream side of the mixing valve so that hot water mixed through the mixing valve does not flow backward to the water supply pipe or the hot water supply pipe.

  By the way, in many check valves used in such a hot water supply apparatus, a flexible packing is attached to the valve body in order to enhance the sealing performance (see, for example, Patent Document 2). The seal is kept high by bringing the packing into close contact with the valve seat when the valve is closed. However, in order to prevent excessive deformation of the packing and to ensure stability when the valve is closed, a support portion made of a rigid body is provided at the back of the packing in the valve body so as to leave a predetermined gap.

JP 2007-32996 A JP 2010-96298 A

  By the way, since such a check valve has a small support structure on the side opposite to the support portion of the packing, if a large back pressure is unexpectedly generated due to some factor, the packing may drop from the valve seat. was there. If such a drop occurs, the check valve cannot perform its function, and it is necessary to take measures against it. In addition, it is thought that such a problem may arise not only in a hot water supply apparatus but also in other fluid devices.

  The present invention has been made in view of such problems, and one of its purposes is to provide a sealing performance when the valve is closed even when a large back pressure is applied to the valve body constituted by the flexible member. It is in providing the check valve which can maintain stably.

  In order to solve the above-described problems, a check valve according to an aspect of the present invention includes a body provided with a fluid passage that connects a primary pressure side and a secondary pressure side, and an annular valve seat provided integrally with the body. The valve seat is opened / closed from the secondary pressure side to open / close the valve seat, and when the differential pressure between the primary pressure and the secondary pressure becomes smaller than the valve opening differential pressure, the valve is closed and the forward direction of the working fluid is And a valve body for blocking the flow. The valve body includes a main body that is slidably supported by the body, a flexible disk-shaped valve member that is supported by the main body and is attached to and detached from the valve seat, and extends radially outward from the main body. Supporting the member on the side opposite to the valve seat, and a support portion formed with a notch surface that is spaced away from the valve member toward the radially outward position at a predetermined radial position on the surface facing the valve seat; including. When the diameter of the contact portion between the valve member and the valve seat is D1, the diameter of the base end portion of the notch surface is D2, and the outer diameter of the valve member is D3, the relationship of D1 <D2 <D3 is established. To do.

  According to this aspect, since the flexible valve member is seated on the valve seat when the valve is closed, the sealing performance as a check valve can be maintained high. On the other hand, when the diameter of the contact portion between the valve member and the valve seat is D1, the diameter of the base end portion of the notch surface in the support portion is D2, and the outer diameter of the valve member is D3, D1 <D2 <D3 A relationship is established. For this reason, even if a large unexpected pressure is applied to the check valve, the vicinity of the peripheral edge of the valve member is firmly held between the contact portion of the valve seat and the base end portion of the support portion. Thus, it is possible to prevent the valve member from falling off the valve seat. Moreover, since the clamping location in a valve member is compressed at this time, the thickness of a peripheral part becomes relatively larger than the clamping part. As a result, the peripheral portion exhibits the function of a stopper to suppress the displacement of the valve member inward in the radial direction, thereby further enhancing the effect of preventing the valve member from falling off. At this time, since the valve member is in close contact with not only the valve seat but also the support portion at the clamping portion, it is possible to prevent reverse pressure (secondary pressure) from acting between the valve member back portion, that is, between the valve member and the support portion. Or at least the effect can be considerably reduced. As a result, it is possible to prevent the valve member from dropping from the valve seat due to a large back pressure. That is, according to the check valve of this aspect, even when a large back pressure is applied to the valve body, the sealing performance can be stably maintained.

  Another aspect of the present invention is a compound valve. The composite valve is provided between the first introduction passage for introducing the first working fluid, the second introduction passage for introducing the second working fluid, and the first introduction passage and the second introduction passage. A common body formed with a merging chamber for mixing the first working fluid and the second working fluid, a lead-out passage for deriving the mixed working fluid, and a first introduction passage and a first passage provided in the merging chamber. 2. A mixing valve body that adjusts an opening ratio with the introduction passage and a drive unit that is attached to the body and drives the mixing valve body, and adjusts the mixing ratio of the first working fluid and the second working fluid. And a check valve provided in at least one of the first introduction passage and the second introduction passage.

  The check valve includes an annular valve seat provided integrally with the body, a valve seat that is attached to and detached from the valve seat from the mixing chamber side, and a primary pressure and mixing chamber on the side where the working fluid is introduced. And a valve body that closes when the pressure difference from the secondary pressure on the side becomes smaller than the valve opening differential pressure and blocks the forward flow of the working fluid. The valve body includes a main body that is slidably supported by the body, a flexible disk-shaped valve member that is supported by the main body and is attached to and detached from the valve seat, and extends radially outward from the main body. Supporting the member on the side opposite to the valve seat, and a support portion formed with a notch surface that is spaced away from the valve member toward the radially outward position at a predetermined radial position on the surface facing the valve seat; including. When the diameter of the contact portion between the valve member and the valve seat is D1, the diameter of the base end portion of the notch surface is D2, and the outer diameter of the valve member is D3, the relationship of D1 <D2 <D3 is established. To do.

  According to this aspect, it is possible to provide a composite valve that is easy to handle by assembling the mixing valve and the check valve into a common body to form a unit. And the effect similar to the above can be acquired about the non-return valve integrated in the composite valve.

  ADVANTAGE OF THE INVENTION According to this invention, even if a big back pressure is applied to the valve body comprised by the flexible member, the non-return valve which can maintain the sealing performance at the time of valve closing stably can be provided.

It is a system figure showing composition of a hot water storage type hot water supply device to which a check valve of an embodiment is applied. It is a fragmentary sectional view showing the whole control valve unit composition. It is sectional drawing showing the structure of a 1st check valve. It is sectional drawing showing operation | movement of a 1st check valve. It is sectional drawing showing the drop-off prevention function of a main valve body. It is an expanded sectional view showing the comparative example when the drop-off prevention function of the embodiment does not act. It is sectional drawing showing the structure of a 2nd non-return valve.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system diagram illustrating a configuration of a hot water storage type hot water supply apparatus to which the check valve of the embodiment is applied. The hot water supply apparatus of this embodiment includes a hot water storage unit 10 and a heat pump unit 12. The hot water storage unit 10 includes a hot water storage tank 14, piping for circulating or supplying hot water, a control valve for controlling the flow of hot water, a sensor for detecting the temperature and flow rate of the hot water, and the like.

  The low-temperature water supplied from the water supply is supplied to the hot water storage unit 10 through the water supply pipe 16. The water supply pipe 16 branches in the hot water storage unit 10, and a first water supply pipe 18, which is one of them, is connected to the lower part of the hot water storage tank 14. A boiling circulation circuit is formed between the hot water storage tank 14 and the heat pump unit 12. That is, the outlet pipe 20 connected to the lower part of the hot water storage tank 14 is connected to the heat pump unit 12, and the return pipe 22 connected to the heat pump unit 12 is connected to the upper part of the hot water storage tank 14.

  With such a configuration, the hot water storage tank 14 is formed with a temperature stratification in which high-temperature water is present in the upper part, intermediate-temperature water in the middle part, and low-temperature water in the lower part. The cold / hot water accumulated in the lower part of the hot water storage tank 14 is heat-exchanged by the heat pump unit 12 to be converted into high temperature water and returned to the hot water storage tank 14. The outlet pipe 20 is provided with a pump 24 for promoting circulation of hot water in such a boiling circulation circuit.

  On the other hand, a hot water supply pipe 26 for deriving high temperature water is connected to the upper part of the hot water storage tank 14. The second water supply pipe 28 and the hot water supply pipe 26, which are the other branched from the water supply pipe 16, are connected on the downstream side, and high temperature water and cold / hot water are mixed at their junction. And the hot water which became suitable temperature by the mixing is supplied to a bathtub, a kitchen, or other hot water supply equipment via the piping 30. A control valve unit 32 is provided at a connection point between the hot water supply pipe 26 and the second water supply pipe 28.

  The control valve unit 32 is a composite valve in which a mixing valve 34, a first check valve 36, and a second check valve 38 are integrally assembled in a common body. The mixing valve 34 adjusts the mixing ratio between the high-temperature water supplied through the hot water supply pipe 26 and the low-temperature water supplied through the second water supply pipe 28, and derives hot water at an appropriate temperature into the pipe 30. The piping 30 is provided with a temperature sensor 40 and a flow rate sensor 42 from the upstream side. A control unit (not shown) acquires the temperature of the temperature sensor 40 and controls the opening degree of the mixing valve 34 so as to be a hot water supply temperature set by a user using a remote controller (not shown). On the other hand, the first check valve 36 prevents the hot water in the junction from flowing back into the second water supply pipe 28 when the hot water supply is stopped. The second check valve 38 prevents hot water from the junction from flowing back to the hot water supply pipe 26 when hot water supply is stopped. The specific configuration of the control valve unit 32 will be described later.

  On the other hand, the heat pump unit 12 includes a refrigeration cycle that uses carbon dioxide as a refrigerant. This refrigeration cycle includes a refrigerant circulation circuit including a compressor, a heat exchanger, an expansion valve, and an evaporator. However, since the configuration and operation thereof are known, a detailed description thereof will be omitted. The low-temperature water flowing through the above-described boiling circulation circuit is boiled up into the high-temperature water when passing through the heat exchanger.

Next, a specific configuration of the control valve unit 32 will be described. In the following description, for the sake of convenience, the positional relationship of members may be expressed with reference to the illustrated state.
FIG. 2 is a partial cross-sectional view showing the overall configuration of the control valve unit 32.
The control valve unit 32 has a body 50 obtained by integrally molding a resin material, and is configured by integrally assembling a mixing valve 34, a first check valve 36, and a second check valve 38 on the body 50. ing. In the center of the body 50, a merging chamber 52 for merging high-temperature water and low-temperature water is provided, the mixing valve 34 is assembled in the upper part, and a lead-out passage 54 extending in a cylindrical shape is provided in the lower part. A first introduction passage 56 extending in a cylindrical shape is provided on one side of the body 50, and a second introduction passage 58 extending in a cylindrical shape is provided on the other side. The first introduction passage 56 and the second introduction passage 58 are provided coaxially and are connected to the outlet passage 54 at a right angle. The first introduction passage 56 is connected to the second water supply pipe 28, the second introduction passage 58 is connected to the hot water supply pipe 26, and the outlet passage 54 is connected to the pipe 30.

  The mixing valve 34 includes a valve body 60 having a valve portion for adjusting the opening degrees of the first introduction passage 56 and the second introduction passage 58, and a motor unit 62 as a drive portion for driving the valve portion. The valve body 60 includes a cylindrical guide member 64 that is press-fitted into the upper end opening of the body 50, and a stepped cylindrical valve driver 66 that is rotatably supported by the guide member 64. An O-ring for sealing is interposed between the outer peripheral surface of the guide member 64 and the inner peripheral surface of the body 50.

  The valve drive body 66 has a shaft support portion 67 supported by a guide member 64 so that the upper half of the valve drive body 66 is slidable, and the outer peripheral surface of the shaft support portion 67 ensures a sealing property with the guide member 64. An O-ring is inserted for this purpose. The lower half of the valve driver 66 is expanded in diameter to form a valve body 68 (functioning as a “mixing valve body”), and a merging chamber 52 is formed inside the valve body 68. A rhomboid flow rate adjusting hole 69 is provided in the side portion of the valve body 68 to communicate the inside and outside. The flow rate adjusting hole 69 is formed over about 210 degrees in the circumferential direction of the valve body 68, and when the central portion in the circumferential direction faces one of the first introduction passage 56 and the second introduction passage 58, the other introduction passage is provided. Is configured to be blocked. By controlling the rotational position of the flow rate adjusting hole 69, the opening ratio of the first introduction passage 56 and the second introduction passage 58 can be adjusted, and the mixing ratio of high temperature water and low temperature water can be adjusted.

  The motor unit 62 is configured as a stepping motor including a rotor and a stator (not shown), and is attached so as to seal the upper end opening of the body 50. The upper end portion of the valve body 60 is connected to the rotor, and the rotation of the rotor appears as a rotation operation of the valve body 68. Based on the temperature detected by the temperature sensor 40, the control unit controls the rotational position of the valve body 68 so that the hot water supplied to the hot water supply facility becomes the hot water supply temperature set by the user.

  Each of the first introduction passage 56 and the second introduction passage 58 is formed in a stepped cylindrical shape whose diameter is reduced by one step inward. The first check valve 36 is press-fitted into the large diameter portion of the first introduction passage 56 via an O-ring, and one end thereof is locked to the step portion of the first introduction passage 56. Similarly, the second check valve 38 is press-fitted into the large diameter portion of the second introduction passage 58 via an O-ring, and one end thereof is locked to the step portion of the second introduction passage 58.

FIG. 3 is a cross-sectional view illustrating the configuration of the first check valve 36.
The first check valve 36 coaxially accommodates a large-diameter main valve (first valve portion) and a small-diameter subvalve (second valve portion) inside a body 70 made of a resin material. Configured as follows. The main valve prevents the flow of working fluid from the secondary pressure side to the primary pressure side, and the sub valve opens when the differential pressure between the secondary pressure and the primary pressure exceeds the set differential pressure. A part of the reverse flow is allowed, and the secondary pressure is prevented from rising rapidly. Here, the “primary pressure side” corresponds to the second water supply pipe 28 side (upstream side), and the “secondary pressure side” corresponds to the pipe 30 side (downstream side). A main valve body 72 that opens and closes the main valve is disposed inside the body 70, and a sub-valve body 74 that opens and closes the sub-valve is disposed inside the main valve body 72.

  The body 70 has a cylindrical main body 76. One end of the main body 76 is reduced in diameter to form a main valve hole 78, and the secondary pressure side opening edge projects inward to form an annular main valve seat 80. A ring-shaped guide portion 82 is press-fitted into the other end portion of the main body 76. The central portion of the guide portion 82 projects in a circular boss shape toward the inside of the main body 76, and supports the main valve body 72 so as to be slidable in the axial direction. Around the circular boss portion 83 in the guide portion 82, a plurality of through holes 84 parallel to the axis are provided at equal intervals.

  The main valve body 72 has a main body 86 made of a resin material that is slidably supported by the body 70. The main body 86 has a stepped cylindrical shape, and a support portion 88 extending radially outward is provided at an intermediate portion in the axial direction. The support portion 88 has a disc shape, and the peripheral corner portion thereof is chamfered in a tapered shape (for example, C chamfer of about 0.1 to 1.0 mm). The main body 86 has a tapered portion 90 whose outer diameter gradually increases toward the tip from the support portion 88 on the main valve seat 80 side, and the valve member 92 is fitted to the tapered portion 90. It is assembled.

  The valve member 92 is made of a disc-shaped rubber having flexibility, and has a circular fitting hole formed at the center thereof with the same diameter in the axial direction. The fitting hole is formed in the tapered portion 90. It is assembled to the main body 86 so as to be externally fitted. For this reason, the interference with respect to the valve member 92 of the main body 86 increases as the distance from the support portion 88 increases. In the valve member 92, the thickness of the outer half portion is smaller than that of the inner half portion in the radial direction, and a gap is formed between the outer half portion and the support portion 88. This gap is set to a size that allows the outer half of the valve member 92 to be appropriately bent when the valve is closed.

  A spring receiver 94 is fitted to the distal end portion of the main body 86. The spring receiver 94 has a bottomed cylindrical shape, and an opening end portion thereof is fitted and fixed to a distal end portion of the main body 86. The spring receiver 94 is provided with a through hole 96 along the axis. The valve member 92 is supported such that its inner half is sandwiched between the support portion 88 and the spring receiver 94. The main valve body 72 opens and closes the main valve when the valve member 92 is attached to and detached from the main valve seat 80 at the peripheral edge thereof. A spring 98 (functioning as an “urging member”) that biases the main valve body 72 in the valve closing direction is interposed between the support portion 88 and the guide portion 82.

  On the other hand, in the main body 86, a sub-passage is provided by the axial through-hole, and a partition portion 100 extending inward in the radial direction is provided at the central portion in the axial direction. And the subvalve hole 102 is formed by the inner peripheral part of the division part 100, and the subvalve seat 104 is formed by the primary pressure side opening edge part. The sub valve body 74 is disposed inward of the main body 86, and attaches and detaches from the sub valve seat 104 from the primary pressure side to open and close the sub valve. The sub valve body 74 is a sub body made of a support body 106 made of a resin material slidably inserted into the main valve body, and a flexible member (rubber in the present embodiment) press-fitted into the center of the end surface of the support body 106. A valve member 108 is provided.

  The support 106 has a stepped columnar shape, and a circular recess is formed at the center of the surface facing the sub valve seat 104. The sub-valve member 108 has a cylindrical shape, and is press-fitted into the concave portion so as to partially protrude from the support 106. That is, since the deformation of the sub-valve member 108 is restricted by the support body 106 made of a rigid body, the slidability in the axial direction of the sub-valve element 74 is stable regardless of the valve closing pressure of the sub-valve. Can be maintained. A plurality of communication grooves 110 parallel to the axis are provided on the outer peripheral surface of the auxiliary valve member 108 at equal intervals in the circumferential direction to ensure the flowability of the working fluid. A spring 112 (functioning as a “biasing member”) that biases the auxiliary valve body 74 in the valve closing direction is interposed between the support body 106 and the spring receiver 94.

  In such a configuration, the diameter of the contact portion between the valve member 92 and the main valve seat 80 is D1, and the diameter of the base end portion (starting portion of the tapered surface) of the support portion 88 is as shown in the drawing. When the outer diameter of D2 and the valve member 92 is D3, the relationship of D1 <D2 <D3 is established. As a result, even if an unexpected large back pressure is applied to the first check valve 36, the peripheral portion of the valve member 92 is firmly held between the main valve seat 80 and the support portion 88. The valve member 92 can be prevented from falling off from the main valve seat 80. Hereinafter, the operation of the first check valve 36 and such a drop-off preventing function will be described in detail.

  FIG. 4 is a cross-sectional view illustrating the operation of the first check valve 36. (A) shows the opened state of the first check valve 36 (main valve), (B) shows the closed state of the main valve and the auxiliary valve, (C) shows the opened state of the auxiliary valve, (D) shows a state in which the back pressure is excessive.

  During the operation of the hot water supply apparatus in the present embodiment, as described above, the opening ratio between the hot water supply pipe 26 and the second water supply pipe 28 is adjusted by the mixing valve 34, so that the hot water adjusted to an appropriate temperature at the junction. Is supplied to the hot water supply equipment. At this time, the differential pressure across the first check valve 36 is larger than the differential valve opening pressure (the differential pressure capable of opening the main valve body 72 against the biasing force of the spring 98). As shown to 4 (A), the 1st non-return valve 36 will be in a valve open state (fully opened state). Here, the “open state of the first check valve 36” means a state before the first check valve 36 operates its backflow prevention function, that is, the open state of the main valve.

  On the other hand, when the hot water supply device is stopped, the differential pressure across the first check valve 36 becomes smaller than the valve opening differential pressure. For this reason, as shown to FIG. 4 (B), the 1st non-return valve 36 will be in a valve closing state. However, the counter pressure (the differential pressure between the secondary pressure and the primary pressure) acting on the first check valve 36 in the closed state is the set differential pressure (the sub valve body 74 is opened against the biasing force of the spring 112). 4 (C), the sub valve is opened while the main valve is maintained in the closed state, as shown in FIG. Thereby, the sudden rise of the upstream pressure of the first check valve 36 can be suppressed, and the stability of the hot water storage unit 10 can be ensured.

  In such a situation, if an unexpected large back pressure is applied, the valve member 92 is strongly pressed against the main valve seat 80 as shown in FIG. It is displaced in the direction of being pulled into the hole 78. However, since the above-described valve configuration in the main valve body 72 has a drop-off preventing function, the drop-off of the valve member 92 from the main valve seat 80 is prevented. Details of this drop-off prevention function will be described below.

  FIG. 5 is a cross-sectional view illustrating the main valve body falling-off preventing function. (A) is the A section enlarged view of FIG.4 (C), (B) is the A section enlarged view of FIG.4 (D). FIG. 6 is an enlarged cross-sectional view illustrating a comparative example having a configuration in which the dropout prevention function of the embodiment does not act. (A) shows the normal valve closing state of the main valve, and corresponds to FIG. (B) and (C) show a state in which the back pressure is excessive, and corresponds to FIG.

  As described above, in this embodiment, as shown in FIG. 5A, the diameter of the contact portion between the valve member 92 and the main valve seat 80 is D1, and the diameter of the proximal end portion of the tapered surface of the support portion 88 is as follows. Is D2, and the outer diameter of the valve member 92 is D3, the relationship of D1 <D2 <D3 is established. For this reason, even if unexpected large back pressure is applied to the first check valve 36 as shown in FIG. 5B, the contact portion P1 between the valve member 92 and the main valve seat 80, and the support portion The vicinity of the peripheral edge of the valve member 92 is firmly sandwiched between the base end portion P2 of the tapered surface 88, and the function of preventing the valve member 92 from dropping into the valve member 92 is exhibited. Further, at this time, the sandwiched portion of the valve member 92 is compressed in the width direction, so that the thickness of the outer portion (peripheral portion) becomes larger than the sandwiched portion. As a result, the peripheral portion further exerts a stopper function against the radially inward movement of the valve member 92, thereby further enhancing the effect of preventing the valve member 92 from falling off.

  Further, since the valve member 92 comes into close contact with not only the main valve seat 80 but also the support portion 88 in the clamping portion, the back pressure (secondary pressure) is applied to the back portion of the valve member 92, that is, the valve member 92. It becomes possible to suppress acting on the gap between the outer half portion and the support portion 88. As a result, it is possible to prevent the valve member 92 from dropping into the main valve hole 78 due to the back pressure. That is, even if a large back pressure is applied to the main valve body 72, the sealing performance can be stably maintained.

  Furthermore, in the present embodiment, as described above, the outer diameter of the tapered portion 90 gradually increases from the boundary position with the support portion 88 toward the distal end side (the upper end side in the figure), whereas the valve Since the inner diameter of the member 92 is formed to be constant, the tightening allowance of the tapered portion 90 with respect to the valve member 92 increases as the distance from the support portion 88 increases. For this reason, even if a back pressure acts on the valve member 92 to displace the valve member 92, the valve member 92 and the tapered portion 90 come into closer contact with the displacement. For this reason, both sealing properties are further improved, and it is possible to prevent a situation in which the working fluid flows backward through the clearance between the two.

  On the other hand, for example, as shown in FIG. 6A, a comparative example without a drop-off prevention function as in this embodiment is assumed. In the check valve according to this comparative example, a tapered surface is not provided on the peripheral edge portion of the support portion 188 in the main valve body 172, and a tapered portion is also provided on the outer peripheral surface 190 to which the valve member 192 is fitted. Not.

  For this reason, as shown in FIG. 6 (B), if an unexpected large back pressure is applied to the check valve, the valve member 192 comes into contact with the flat surface of the support portion 188 at the outer peripheral edge P3. The clamping force by the opposing convex part like the said embodiment cannot be made to act between the main valve seat 80 and the support part 188. FIG. In addition, the reverse pressure (secondary pressure) acts on the back portion of the valve member 192 and the valve member 192 is pushed up in a direction away from the support portion 188. As a result, as shown in FIG. 6C, the valve member 192 is easily dropped into the main valve hole 78. When such dropout occurs, the check valve cannot effectively perform its function. In other words, according to the present embodiment, such a problem can be solved by the drop-off prevention structure described above.

  FIG. 7 is a cross-sectional view illustrating the configuration of the second check valve 38. The second check valve 38 has substantially the same configuration as the first check valve 36 except that the second check valve 38 is not provided with a sub valve. For this reason, the same components as those of the first check valve 36 are denoted by the same reference numerals, and the description thereof is omitted.

  The second check valve 38 is configured to accommodate only the large-diameter main valve inside the body 70. The main valve prevents the flow of working fluid from the secondary pressure side to the primary pressure side. Here, the “primary pressure side” corresponds to the hot water supply pipe 26 side (upstream side), and the “secondary pressure side” corresponds to the pipe 30 side (downstream side). A main valve body 120 that opens and closes the main valve is disposed inside the body 70.

  The main valve body 120 has a main body 122 made of a resin material that is slidably supported by the body 70. The main body 122 has a stepped columnar shape, and a support portion 88 is provided at an intermediate portion in the axial direction. The main body 122 is a tapered portion 90 whose outer diameter gradually increases from the support portion 88 toward the tip, and the valve member 92 is assembled to the tapered portion 90. The front end portion of the main body 122 is a flange-shaped locking portion 124, and the inner peripheral portion of the valve member 92 is fitted into a recess formed between the support portion 88 and the locking portion 124. Similar to the first check valve 36, the tightening allowance of the main body 122 with respect to the valve member 92 increases as the distance from the support portion 88 increases.

  In such a configuration, as shown in the figure, the diameter of the contact portion between the valve member 92 and the main valve seat 80 is D1, the diameter of the proximal end portion of the tapered surface of the support portion 88 is D2, and the outside of the valve member 92 When the diameter is D3, the relationship of D1 <D2 <D3 is established. As a result, even if an unexpected large back pressure is applied to the second check valve 38, the peripheral portion of the valve member 92 is firmly held between the main valve seat 80 and the support portion 88. The valve member 92 can be prevented from dropping into the main valve hole 78. Since the dropout prevention function is the same as that of the first check valve 36, the description thereof is omitted.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the technical idea of the present invention. Nor.

  In the above embodiment, an example in which the peripheral portion of the support portion 88 has a tapered surface by C chamfering is shown as an example of the structure of the support portion 88, but for example, a curved surface shape by R chamfering may be used. Various shapes can be adopted as long as they are notched surfaces that are separated from each other. Moreover, in the said embodiment, the thickness of the outer half part of the valve member 92 was made smaller than the inner half part, and the example which made the flat surface from the center to the base end part of the taper surface about the support part 88 was shown. In the modified example, conversely, the valve member may be formed with a constant thickness, while the surface of the support portion facing the valve member may have a stepped shape. Specifically, a stepped shape in which the outer half of the support portion is lowered by one step relative to the inner half, and a predetermined gap may be provided between the outer half of the valve member. However, also in this case, a notch surface that is separated from the valve member toward the outer periphery in the radial direction is provided at the peripheral portion of the support portion, and the diameter of the contact portion between the valve member and the valve seat is D1, and the notch surface When the diameter of the base end portion is D2 and the outer diameter of the valve member is D3, the relationship of D1 <D2 <D3 is established.

  In the above embodiment, as shown in FIG. 2, the first check valve 36 having a main valve and a sub valve in the first introduction passage 56 (that is, the introduction passage on the second water supply pipe 28 side) of the control valve unit 32. The second check valve 38 having only the main valve in the second introduction passage 58 (that is, the introduction passage on the hot water supply pipe 26 side) is shown. In the modified example, conversely, the second check valve 38 may be disposed in the first introduction passage 56 and the first check valve 36 may be disposed in the second introduction passage 58. Alternatively, the first check valve 36 may be disposed in both the first introduction passage 56 and the second introduction passage 58. Alternatively, the second check valve 38 may be disposed in both the first introduction passage 56 and the second introduction passage 58. In addition, any one of the check valves may be provided only in one of the first introduction passage 56 and the second introduction passage 58.

  In the said embodiment, the check valve of this invention was comprised as a control valve which prevents the backflow of hot water as a working fluid, and the example applied to a hot water storage type hot-water supply apparatus was shown. In a modification, you may apply to the required location of an instant type hot-water supply apparatus. Further, for example, a system that needs to prevent backflow from the secondary pressure side to the primary pressure side, such as a refrigeration cycle using a refrigerant as a working fluid, can be similarly applied.

  DESCRIPTION OF SYMBOLS 10 Hot water storage unit, 12 Heat pump unit, 14 Hot water storage tank, 16 Water supply pipe, 18 1st water supply pipe, 20 Outlet pipe, 22 Return pipe, 26 Hot water supply pipe, 28 2nd water supply pipe, 30 Piping, 32 Control valve unit, 34 Mixing Valve, 36 first check valve, 38 second check valve, 50 body, 52 merging chamber, 54 outlet passage, 56 first introduction passage, 58 second introduction passage, 60 valve body, 62 motor unit, 68 valve body 69 Flow adjustment hole, 70 Body, 72 Main valve body, 74 Sub valve body, 78 Main valve hole, 80 Main valve seat, 86 Main body, 88 Support part, 90 Taper part, 92 Valve member, 102 Sub valve hole, 104 Sub valve seat, 106 support body, 108 sub valve member, 120 main valve body, 122 main body.

Claims (5)

A body provided with a fluid passage connecting the primary pressure side and the secondary pressure side;
An annular valve seat provided integrally with the body;
The valve seat is opened and closed by attaching and detaching to the valve seat from the secondary pressure side, and when the differential pressure between the primary pressure and the secondary pressure becomes smaller than the valve opening differential pressure, the valve is closed and the forward direction of the working fluid is increased. A valve body for blocking the flow;
With
The valve body is
A main body slidably supported by the body;
A disc-shaped valve member having flexibility to be attached to and detached from the valve seat supported by the body;
Extending radially outward from the main body, supporting the valve member on the opposite side of the valve seat, and toward the predetermined radial direction on the surface facing the valve seat, A support portion formed with a notch surface spaced from the valve member;
Including
When the diameter of the contact portion between the valve member and the valve seat is D1, the diameter of the base end portion of the notch surface is D2, and the outer diameter of the valve member is D3, the relationship of D1 <D2 <D3 A check valve characterized by the fact that The valve body is
Having the support part in the axial direction intermediate part of the columnar or cylindrical body,
A taper portion whose outer diameter gradually increases toward the tip side of the support portion of the main body toward the valve seat side;
The valve member is
It has a circular fitting hole that is penetrated and formed with the same diameter in the axial direction,
The fitting hole is attached to the main body so as to be fitted to the tapered portion,
2. The check valve according to claim 1, wherein the check valve is supported by the main body such that an inner half portion in a radial direction abuts on the support portion and an outer half portion is separated from the support portion. The valve member is formed such that the outer half in the radial direction has a smaller thickness than the inner half, and is attached to and detached from the valve seat at the outer half.
3. The check according to claim 2, wherein the support portion abuts the valve member on a flat surface perpendicular to the axis of the main body, and has a tapered surface as the notch surface on an outer edge portion thereof. valve. A main valve seat as the valve seat;
A main valve body that opens and closes the first valve portion by attaching to and detaching from the main valve seat as the valve body;
A sub-valve seat provided in a sub-passage that penetrates the main valve body in the axial direction;
The second valve portion is opened and closed by contacting and separating from the sub-valve seat from the primary pressure side, and the differential pressure between the secondary pressure and the primary pressure becomes larger than the set differential pressure when the first valve portion is closed. A sub-valve that opens to allow back flow of the working fluid when
Further comprising
The auxiliary valve body is
A flexible auxiliary valve member that attaches and detaches to and from the auxiliary valve seat and opens and closes the second valve portion; and
A support body that is slidably inserted into the main valve body and supports the sub valve member so as to be accommodated in a central portion of the surface facing the sub valve seat;
The check valve according to claim 1, comprising: A first introduction passage for introducing a first working fluid; a second introduction passage for introducing a second working fluid; and the first introduction passage and the second introduction passage provided between the first introduction passage and the first introduction passage. A common body formed with a merging chamber for mixing the working fluid and the second working fluid, and a lead-out passage for leading the mixed working fluid;
A mixing valve body that is provided in the merging chamber and adjusts an opening ratio of the first introduction passage and the second introduction passage; and a drive unit that is attached to the body and drives the mixing valve body, A mixing valve that adjusts a mixing ratio of the first working fluid and the second working fluid;
A check valve provided in at least one of the first introduction passage and the second introduction passage;
A composite valve comprising:
The check valve is
An annular valve seat provided integrally with the body;
The valve seat is opened and closed by attaching and detaching to the valve seat from the mixing chamber side, and the differential pressure between the primary pressure on the side introducing the working fluid and the secondary pressure on the mixing chamber side is smaller than the valve opening differential pressure. A valve body that is sometimes closed to block the forward flow of the working fluid;
With
The valve body is
A main body slidably supported by the body;
A disc-shaped valve member having flexibility to be attached to and detached from the valve seat supported by the body;
Extending radially outward from the main body, supporting the valve member on the opposite side of the valve seat, and toward the predetermined radial direction on the surface facing the valve seat, A support portion formed with a notch surface spaced from the valve member;
Including
When the diameter of the contact portion between the valve member and the valve seat is D1, the diameter of the base end portion of the notch surface is D2, and the outer diameter of the valve member is D3, the relationship of D1 <D2 <D3 A composite valve characterized by the fact that

Images