JP2014139528A - Flow rate detection unit and hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flow rate detection unit that is hardly affected by foreign materials and is more preferably obtained at low cost and a hot water supply system.SOLUTION: A flow rate detection unit is a unit for detecting a flow rate of liquid flowing in a pipe. The flow rate detection unit comprises: a check valve 66 for providing flow resistance against liquid flowing through a pipe; and a flow sensor 68 that is arranged in parallel with the pipe and detects a flow rate of liquid by sensing differential pressures between upstream side pressures and downstream side pressures of the check valve 66.

Description

  The present invention relates to a flow rate detection unit for detecting a flow rate of a fluid flowing through a pipe, and a hot water supply system having a flow rate detection function.

  In general, a hot water supply apparatus is provided with a reheating circulation path for replenishing hot water stored in the bathtub in addition to a dropping hot water supply path for dropping hot water adjusted to an appropriate temperature into the bathtub. In such a hot water supply apparatus, a flow sensor is provided in the dropping hot water supply passage, and the flow rate dropped into the bathtub is monitored when filling the hot water. In addition, a similar flow sensor or flow switch is provided for detecting the circulating flow rate of hot water in the circulation path. However, such an increase in sensors and switches leads to an increase in size and complexity of the apparatus and an increase in manufacturing cost. Therefore, a configuration is also proposed in which a common flow rate detection device for detecting the dropped flow rate and the recirculation circulation flow is provided at the connecting portion between the drop hot water supply channel and the recirculation circulation route (see, for example, Patent Document 1). . Such a flow rate detection device generally includes an impeller that rotates in response to a flow, and detects the flow rate from the number of rotations.

JP-A-10-185636

  However, since chasing is usually performed after a person takes a bath, the circulating hot water is dirty water containing dirt such as skin and foreign matters such as hair. For this reason, when a foreign material flows due to the circulation of the sewage, there is a concern that the foreign material adheres to the rotating part or the movable part of the impeller for detecting the flow rate, and the impeller is fixed or locked.

  The present invention has been made in view of such a problem, and one of its purposes is to provide a flow rate detection unit and a hot water supply system that are not easily affected by foreign matter and can be realized at low cost.

  In order to solve the above problems, a flow rate detection unit according to an aspect of the present invention is a flow rate detection unit for detecting a flow rate of a fluid flowing through a pipe, and is a reverse flow unit that is installed in the pipe and prevents a reverse flow of the fluid. A stop valve, and a detection unit that is provided in parallel with the pipe and detects the flow rate of the fluid by sensing a differential pressure between the upstream pressure and the downstream pressure of the check valve.

  According to this aspect, a unit in which a differential pressure type flow rate detection function that uses a check valve provided in the flow path as it is in order to prevent a back flow in the pipe is configured. Since the flow rate detection unit is a differential pressure type, it is not necessary to provide a rotating part such as an impeller in the flow path for detecting the flow rate, and a configuration that is resistant to foreign matters can be provided. In addition, paying attention to the fact that the check valve is fully open when a normal flow is formed in the piping, and the check valve also functions as a fixed orifice in the fully open state, differential pressure type flow rate detection using this I could devise a method. In other words, there is an advantage that the number of parts can be reduced because a check valve installed in the pipe is used as it is, instead of providing a separate throttle for detecting the flow rate.

  Another aspect of the present invention is a hot water supply system. This hot water supply system includes a circulation circuit for circulating hot water in a bathtub, a hot water supply pipe connected to the circulation circuit for supplying temperature-controlled hot water to the bathtub through the circulation circuit, and a circulation circuit in the hot water supply pipe. A check valve provided on the upstream side of the connection point and a hot water supply pipe are installed in parallel to sense the differential pressure between the upstream and downstream pressures of the check valve and output a detection signal corresponding to the differential pressure. And a determination unit that calculates a fluid flow state based on a detection result of the detection unit.

  According to this aspect, the differential pressure type flow rate detection unit is configured such that the check valve installed to prevent the back flow of hot water from the circulation circuit to the hot water supply pipe is used as it is. For this reason, it becomes unnecessary to provide rotating parts, such as an impeller, in the flow path, and the structure strong against a foreign material can be provided. In addition, there is an advantage that the number of parts can be reduced because an existing check valve installed in the pipe is used as a fixed orifice instead of separately providing a throttle for detecting the flow rate.

  According to the present invention, it is possible to provide a flow rate detection unit and a hot water supply system that are hardly affected by foreign matter and can be realized at low cost.

It is a system figure showing composition of a hot water storage type hot-water supply device concerning an embodiment. It is sectional drawing showing the whole structure of a control valve unit. It is a partial expanded sectional view showing the structure of a control valve and its periphery. It is a partial expanded sectional view showing the structure of a flow sensor and its periphery.

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 according to an embodiment. 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 “pipe” such as the following water supply pipe means a conduit through which a fluid can flow, and includes a flow path in the apparatus in addition to a member connecting the apparatus and components. The hot water supply device supplies hot water adjusted to an appropriate temperature by the hot water storage unit 10 to water supply equipment such as the bathtub 13 and the currant 15. The hot water supply device includes a hot water supply circuit that drops hot water sent from the hot water storage tank 14 and adjusted to an appropriate temperature into the bathtub 13, and a reheating circulation circuit for replenishing hot water stored in the bathtub 13.

  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 into a first water supply pipe 17, a second water supply pipe 18 and a third water supply pipe 19 in the hot water storage unit 10. Among these, the first water supply pipe 17 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. Note that low temperature water is supplied to the currant 15 through a water supply pipe 16 in a separate system from the hot water supply apparatus.

  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 portion, intermediate temperature water is present in the middle portion, and low temperature water is present in the lower portion. The cold / hot water accumulated in the lower part of the hot water storage tank 14 is subjected to heat exchange by the heat pump unit 12 to become high temperature water, and is returned to the hot water storage tank 14. The outlet pipe 20 is provided with a pump 23 for promoting circulation of hot water in such a boiling circulation circuit.

  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.

  A reheating heat source circuit for reheating is also connected to the hot water storage tank 14. That is, the heating circuit 24 that connects the upper part and the lower part of the hot water storage tank 14 is provided, and the heat exchanger 70 and the pump 72 are provided in the middle thereof. The pump 72 is driven at the time of chasing. Thereby, the high-temperature water accumulated in the upper part of the hot water storage tank 14 is led to the heat exchanger 70, and heat exchange is performed with the hot water flowing through the circulation passage 82 on the bathtub 13 side. Hot water whose temperature has decreased due to heat exchange is returned to the hot water storage tank 14.

  On the other hand, a hot water supply pipe 25 for deriving high temperature water is connected to the upper part of the hot water storage tank 14. The hot water supply pipe 25 is branched into a first hot water supply pipe 26 and a second hot water supply pipe 28. The first hot water supply pipe 26 is connected to the second water supply pipe 18, and the second hot water supply pipe 28 is connected to the third water supply pipe 19. The high-temperature water flowing through each hot water supply pipe and the low-temperature water flowing through each water supply pipe are mixed at a connection portion (merging portion) of those pipes. The hot water having an appropriate temperature by mixing the high temperature water in the first hot water supply pipe 26 and the cold and hot water in the second water supply pipe 18 is supplied to the currant 15 such as a kitchen via the pipe 30. On the other hand, the hot water having an appropriate temperature by mixing the hot water in the second hot water supply pipe 28 and the cold and hot water in the third water supply pipe 19 is supplied to the bathtub 13 through the pipe 32.

  A first mixing valve 36 is provided at a connection point between the first hot water supply pipe 26, the second water supply pipe 18 and the pipe 30. The first mixing valve 36 adjusts the mixing ratio between the high-temperature water supplied through the first hot water supply pipe 26 and the low-temperature water supplied through the second water supply pipe 18, and supplies hot water with an appropriate temperature to the pipe 30. To derive. A check valve 40 is provided upstream of the first mixing valve 36 in the first hot water supply pipe 26. A check valve 42 is provided on the upstream side of the first mixing valve 36 in the second water supply pipe 18. The pipe 30 is provided with a temperature sensor 48 and a flow sensor 50 from the upstream side. A control unit (not shown) acquires the temperature of the temperature sensor 48 and controls the opening degree of the first mixing valve 36 so as to be a hot water supply temperature set by a user with a remote controller (not shown). The check valve 40 prevents hot water from the junction from flowing back to the first hot water supply pipe 26 when hot water supply is stopped. The check valve 42 prevents hot water from the junction from flowing back to the second water supply pipe 18 when hot water supply is stopped.

  On the other hand, a second mixing valve 38 is provided at a connection point between the second hot water supply pipe 28, the third water supply pipe 19 and the pipe 32. The second mixing valve 38 adjusts the mixing ratio between the high temperature water supplied via the second hot water supply pipe 28 and the low temperature water supplied via the third water supply pipe 19, and supplies hot water with an appropriate temperature to the pipe 32. To derive. A check valve 44 is provided upstream of the second mixing valve 38 in the second hot water supply pipe 28. A check valve 46 is provided upstream of the second mixing valve 38 in the third water supply pipe 19. The piping 32 is provided with a temperature sensor 52 and a control valve unit 54 from the upstream side. A control unit (not shown) acquires the temperature of the temperature sensor 52 and controls the opening degree of the second mixing valve 38 so as to be a hot water supply temperature set by a user using a remote controller (not shown). The check valve 44 prevents hot water from the junction from flowing back to the second hot water supply pipe 28 when hot water supply is stopped. The check valve 46 prevents the hot water in the junction from flowing back to the third water supply pipe 19 when the hot water supply is stopped.

  A check valve 55, a pressure reducing valve 56, and a shutoff valve 58 are provided upstream of the branch point of the water supply pipe 16 with the first water supply pipe 17. The pressure reducing valve 56 appropriately reduces the pressure of the cold / hot water supplied through the water supply pipe 16. That is, pressure adjustment is appropriately performed so that the hot water storage tank 14 and the like are not damaged by water pressure. The shutoff valve 58 shuts off the water supply pipe 16 when predetermined hot water has accumulated in the hot water storage tank 14 and appropriately stops the supply of cold / hot water. The check valve 55 prevents back flow of hot water in the water supply pipe 16 when water supply to the hot water storage unit 10 is stopped.

  The control valve unit 54 is provided with a control valve 60, a check valve 62, an atmosphere release valve 64, a check valve 66, and a flow sensor 68 from the upstream side. The control valve 60 is an electromagnetic valve, and allows or blocks the supply of hot water to the bathtub 13 by opening and closing the pipe 32. The check valve 66 and the check valve 62 prevent the backflow of hot water from the bathtub 13 toward the hot water storage tank 14 in a stepwise manner. The atmosphere release valve 64 opens the space between the check valve 62 and the check valve 66 to the atmosphere in response to a pressure drop on the upstream side (primary side).

  That is, for example, when the bathtub 13 is installed at a position higher than the hot water storage unit 10, when the check valve 66 disposed on the side of the bathtub 13 has poor watertightness due to the biting of foreign matter, The sewage in the bathtub 13 flows back to the atmosphere release valve 64 through the check valve 66 due to the water head pressure. Even in such a case, since the sewage is discharged to the atmosphere by the atmosphere release valve 64, the sewage in the bathtub 13 can be prevented from flowing back to the hot water storage unit 10 and thus to the water supply.

  The pipe 32 branches at a branch point P on the downstream side of the control valve unit 54 into a connection passage 80 directly connected to the bathtub 13 and a circulation passage 82 forming a recirculation circuit. A pump 84 is provided in the connection passage 80, and a heat exchanger 70 is provided in the middle of the circulation passage 82. The pump 84 is driven only when reheating. That is, when filling the bathtub 13 with hot water, the control valve 60 is opened, and hot water adjusted to an appropriate temperature by the second mixing valve 38 is supplied. The hot water branches at a branch point P, and is supplied to the bathtub 13 through the connection passage 80 on the one hand and to the bathtub 13 through the circulation passage 82 on the other hand, as indicated by the solid arrow in the figure. However, since the pump 72 is not driven at the time of hot water filling, reheating is not performed. The amount of hot water supplied during hot water filling is calculated based on the detection value of the flow sensor 68. When the supply of hot water of a predetermined flow rate is completed, the control valve 60 is closed and hot water filling is stopped.

  On the other hand, the pumps 72 and 84 are driven at the time of reheating. As a result, as indicated by a dotted arrow in the figure, hot water in the bathtub 13 is sent out toward the heat exchanger 70 and circulates in the recirculation circuit. The cooled hot water discharged from the bathtub 13 is heat-exchanged by the heat exchanger 70 to be heated, and returned to the bathtub 13 again. By this reheating, the hot water in the bathtub 13 is warmed to an appropriate temperature. In addition, since the control valve 60 is closed and the check valve 66 is maintained in the closed state at the time of reheating, the sewage in the bathtub 13 does not flow back to the pipe 32.

  In the present embodiment, when hot water filling is performed, an integrated value of the flow rate of hot water detected by the flow sensor 68 is calculated, and the control valve 60 is closed when the integrated value reaches a set hot water amount. . Thereby, hot water filling is completed. In addition, when performing reheating, the flow sensor 68 detects whether hot water is circulating in the recirculation circuit. That is, the flow sensor 68 provided in the control valve unit 54 functions as a flow sensor for detecting the amount of hot water when the hot water is filled, and the flow switch for detecting whether or not the hot water is circulated during reheating. Also works. When the flow sensor 68 functions as the latter flow switch, it is also possible to obtain a guide for the renewal end time based on the circulation duration time. Details of the configuration and operation of the flow sensor 68 will be described later.

Next, a specific configuration of the control valve unit 54 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 cross-sectional view illustrating the overall configuration of the control valve unit 54. The control valve unit 54 includes a control valve 60, a check valve 62 (first check valve), an atmosphere release valve 64, a check valve 66 (second check valve) in a common body 100 obtained by molding a resin material. Valve) and flow sensor 68 are integrally assembled. The body 100 includes an introduction tube portion 104 that is continuous with a side portion of the cylindrical main body 102 and a lead-out tube portion 106 that is continuously provided below the main body 102. Further, a body 108 of the atmosphere release valve 64 and a body 110 of the flow sensor 68 are integrally provided on the side portion of the main body 102.

  The introduction pipe portion 104 is connected to the main body 102 at a right angle. The outlet tube portion 106 is connected to the main body 102 coaxially. The opening end portion of the introduction pipe portion 104 functions as an introduction port for introducing hot water from the upstream side, and the opening end portion of the outlet pipe portion 106 functions as an outlet port for leading hot water to the downstream side. The upper end opening of the main body 102 is sealed by assembling the control valve 60. A circular boss 112 extending concentrically with the main body 102 is provided at a connection portion between the main body 102 and the outlet pipe portion 106. For this reason, the side part of the circular boss part 112 is located on the axis of the introduction pipe part 104. The hot water introduced into the introduction pipe portion 104 flows into the main body 102 so as to go around the circular boss portion 112. In the vicinity of the opening end portion of the introduction pipe portion 104, a strainer 114 for suppressing the inflow of foreign matter is disposed.

FIG. 3 is a partially enlarged cross-sectional view showing the configuration of the control valve 60 and its surroundings.
The control valve 60 is configured by integrally assembling a valve main body 116 having a valve mechanism and a solenoid 118 serving as a drive unit. The upper part of the main body 102 constitutes the body of the valve main body 116. The upper end opening of the main body 102 is sealed from above by assembling the solenoid 118. The control valve 60 includes a main valve 120 that controls the flow of hot water flowing from the upstream side passage to the downstream side passage, and a pilot valve 122 that controls the open / closed state of the main valve 120.

  A main valve hole 124 is formed by the inner peripheral portion of the circular boss portion 112 described above, and a main valve seat 126 is formed at an upstream opening end portion thereof. A space surrounding the circular boss portion 112 is a pressure chamber 128 communicating with the introduction pipe portion 104, and a large-diameter main valve body 130 is disposed in the pressure chamber 128. The main valve body 130 is attached to and detached from the main valve seat 126 to open and close the main valve 120.

  The main valve body 130 is supported by a flexible diaphragm 132 that is sandwiched between the body 100 and the solenoid 118. The diaphragm 132 has a central portion attached to the bottom of the main valve body 130, and a thick portion along the bottom constitutes a part of the main valve body 130 that is attached to and detached from the main valve seat 126. The main valve body 130 and the diaphragm 132 define a back pressure chamber 134 on the side opposite to the circular boss portion 112. Further, the main valve body 130 is provided with an orifice 136 (leak passage) through which the inside and outside of the back pressure chamber 134 are communicated and a part of hot water from the introduction pipe portion 104 can be introduced into the back pressure chamber 134.

  A boss portion protruding toward the back pressure chamber 134 is provided at the center of the main valve body 130, and a pilot valve seat 138 is formed by the upper end surface of the boss portion. A pilot valve hole 140 is formed so as to penetrate the central portion of the main valve body 130 in the axial direction. The back pressure chamber 134 is provided with a pilot valve body 142 driven by a solenoid 118. The pilot valve body 142 is attached to and detached from the pilot valve seat 138 to open and close the pilot valve 122. The pilot valve body 142 is made of an elastic body (rubber in this embodiment), and is fixed to the plunger 144 of the solenoid 118.

  On the other hand, the solenoid 118 is provided on the outside of the sleeve 146, a bottomed stepped cylindrical sleeve 146 attached to seal the upper end opening of the body 100, a plunger 144 disposed in the sleeve 146, and the sleeve 146. A bobbin 150 and an electromagnetic coil 152 wound around the bobbin 150. The pilot valve body 142 is fitted to the lower end portion of the plunger 144 and operates integrally with the plunger 144. Between the bottom of the sleeve 146 and the plunger 144, a spring 154 (corresponding to an “urging member”) for biasing the pilot valve body 142 in the valve closing direction via the plunger 144 is interposed.

  In such a configuration, a passage connecting the introduction pipe portion 104 and the lead-out pipe portion 106 without the back pressure chamber 134 forms a main passage, and the lead pipe portion 104 and the lead-out pipe portion 106 are connected to the back pressure chamber 134. A passage connecting through the lanes constitutes a secondary passage. The pressure in the back pressure chamber 134 varies depending on the open / close state of the pilot valve 122.

  With such a configuration, when the solenoid 118 is turned off (non-energized state), the pilot valve 122 is closed to close the sub-passage, and the main valve 120 is closed to shut off the main passage. That is, since the solenoid force does not act, the pilot valve body 142 is urged in the valve closing direction by the spring 154, and the pilot valve 122 is closed. At this time, the pressure in the back pressure chamber 134 and the upstream pressure of the main valve 120 become substantially equal, and the differential pressure between the upstream pressure and the downstream pressure of the main valve 120 acts on the main valve body 130 in the valve closing direction. To do. In a normal state in which the upstream pressure (primary pressure) is high, the main valve body 130 is pushed down and seated on the main valve seat 126 to close the main valve 120.

  On the other hand, in a state where the solenoid 118 is turned on (energized state), the pilot valve 122 opens to open the auxiliary passage, and the main valve 120 opens to open the main passage. That is, since the solenoid force acts, the pilot valve body 142 is driven in the valve opening direction against the biasing force of the spring 154, and the pilot valve 122 is opened. At this time, the pressure in the back pressure chamber 134 and the downstream pressure of the main valve 120 are substantially equal, and the differential pressure between the upstream pressure and the downstream pressure of the main valve 120 acts on the main valve body 130 in the valve opening direction. To do. In a normal state where the upstream pressure (primary pressure) is high, the main valve body 130 is pushed up, and is separated from the main valve seat 126 to open the main valve 120.

  When filling the bathtub 13, the solenoid 118 is turned on, and the main valve 120 is opened to allow water flow. When the bath 13 is not filled with water, the solenoid 118 is turned off and the main valve 120 is closed to shut off the water flow.

  The check valve 62 and the check valve 66 are configured as a check valve unit incorporated in the outlet pipe portion 106. That is, this check valve unit is configured by coaxially assembling the first valve body 162 and the second valve body 164 to a stepped cylindrical body 160. The body 160 is press-fitted into the outlet pipe portion 106 via an O-ring 166. A valve hole 90 is provided at the lower end of the circular boss portion 112, and a valve seat 92 is formed at the downstream opening end thereof. Circular boss-shaped bearing portions 168 and 170 are provided at the upstream opening end and the downstream opening end of the body 160. The first valve body 162 is slidably supported by the bearing portion 168, and is attached to and detached from the valve seat 92 from the downstream side to open and close the check valve 62. A spring 172 that urges the first valve body 162 in the valve closing direction is interposed between the first valve body 162 and the bearing portion 168. The bearing portion 168 is provided with a communication hole 174 for communicating the upstream side and the downstream side thereof.

  The second valve body 164 has the same configuration as the first valve body 162. The upper half of the body 160 has a reduced diameter, and a valve hole 176 is formed by the inner periphery thereof. A valve seat 178 is formed by the downstream opening end of the valve hole 176. The second valve body 164 is slidably supported by the bearing portion 170, and is attached to and detached from the valve seat 178 from the downstream side to open and close the check valve 66. A spring 180 that biases the second valve body 164 in the valve closing direction is interposed between the second valve body 164 and the bearing portion 170. The bearing portion 170 is provided with a communication hole 182 that allows the upstream side and the downstream side to communicate with each other. In order to suppress unnecessary pressure loss during normal flow rate control, the spring load of each spring 172, 180 is set to be relatively small.

  The air release valve 64 is provided on the opposite side of the body 100 from the introduction pipe portion 104. The body 108 of the atmosphere release valve 64 is configured by assembling a main body 192 integrally formed with the body 100 and a housing 194 that seals the main body 192 from the side through an O-ring 196 and a diaphragm 198. The body 108 is divided into a pressure sensitive chamber 200 and an open chamber 202 by a diaphragm 198. The pressure sensing chamber 200 communicates with the pressure chamber 128 of the main body 102 through the pressure detection passage 204 and the small hole 206 and introduces a primary pressure of hot water introduced from the introduction pipe portion 104.

  On the one hand, the open chamber 202 communicates with the outlet pipe portion 106 via a slightly smaller diameter connecting passage 210, and on the other hand, is opened to the atmosphere via a discharge passage 212. The connection passage 210 communicates with a position downstream of the valve hole 90 in the outlet pipe portion 106 and upstream of the valve hole 176. A valve seat 214 is formed at the step between the open chamber 202 and the connection passage 210.

  A valve body 216 is disposed in the open chamber 202 so as to be supported on one side surface of the diaphragm 198. That is, the central portion inside the diaphragm 198 is recessed so as to be fitted with a convex portion formed on the opposed end surface of the valve body 216, and the valve body 216 is positioned at the center of the open chamber 202. A valve member 218 made of a ring-shaped elastic body (for example, rubber) is fitted on a surface of the valve body 216 facing the valve seat 214, and the valve member 218 is attached to and detached from the valve seat 214 to be connected to the atmosphere release valve 64. Open and close. Between the valve body 216 and the body 108, a spring 220 (functioning as an “urging member”) that biases the valve body 216 in the valve opening direction is interposed.

FIG. 4 is a partially enlarged cross-sectional view showing the configuration of the flow sensor 68 and its surroundings.
The flow sensor 68 has a body 110 connected to a side portion of the outlet tube portion 106. The body 110 is configured by joining the first housing 222 and the second housing 224 so that the openings of each other face each other, and forms a pressure-sensitive chamber. A diaphragm 226 as a pressure-sensitive member is provided so that the peripheral edge is sandwiched between the first housing 222 and the second housing 224. A diaphragm 226 divides the pressure sensitive chamber in the body 110 into a first chamber 232 and a second chamber 234. The first chamber 232 communicates with the upstream side of the check valve 66 in the outlet pipe portion 106 via the first communication path 236. On the other hand, the second chamber 234 communicates with the downstream side of the check valve 66 in the outlet pipe portion 106 via the second communication passage 238.

  A stepped columnar support member 240 is joined to the surface of the diaphragm 226 on the first chamber 232 side. The support member 240 is disposed so as to be supported on one side surface of the diaphragm 226. That is, the central portion of the diaphragm 226 is recessed so as to be fitted with the convex portion formed on the opposing end surface of the support member 240, and the support member 240 is positioned at the center of the first chamber 232. The support member 240 extends coaxially in a direction away from the diaphragm 226, and a magnet 242 (permanent magnet in the present embodiment) is fixed to the distal end portion thereof.

  On the other hand, a magnetic sensor 244 is embedded in a portion of the first housing 222 facing the magnet 242. On the surface of the first housing 222 facing the magnet 242, a circular boss-shaped guide part 246 protrudes. The support member 240 is slidably supported by the guide portion 246. Accordingly, the magnet 242 is stably displaced in the axial direction together with the diaphragm 226, and approaches or separates from the magnetic sensor 244. On the other hand, a disk 248 is attached to the surface of the diaphragm 226 on the second chamber 234 side. A spring 250 is interposed between the bottom of the second housing 224 and the disk 248.

  With such a configuration, the diaphragm 226 detects and displaces the differential pressure across the check valve 66, that is, the differential pressure (P1-P2) between the upstream pressure P1 and the downstream pressure P2. The magnetic sensor 244 outputs a detection signal corresponding to the displacement of the magnet 242 accompanying the displacement of the diaphragm 226. Diaphragm 226 is positioned approximately at the center (operation reference position) of body 110 when differential pressure (P1-P2) does not act due to its own elastic force and biasing force of spring 250. And according to differential pressure | voltage (P1-P2), it is arrange | positioned so that a displacement is possible in both the 1st chamber 232 and the 2nd chamber 234 with respect to the reference position. As a result, the magnet 242 is displaced from the initial position corresponding to the reference position. The spring 250 is provided to elastically support the diaphragm 226, but may be replaced with any elastic member such as rubber.

  When the hot water is filled, the control valve 60 is opened, and the temperature-controlled hot water flows from the introduction pipe portion 104 toward the outlet pipe portion 106. At this time, the check valve 66 is fully opened, but a pressure loss due to flow resistance is generated, so that a differential pressure (P1-P2) is generated between the upstream side and the downstream side. At that time, the upstream pressure P1 becomes higher than the downstream pressure P2 (P1> P2), and the diaphragm 226 is displaced to the second chamber 234 side from the reference position. That is, the magnet 242 is displaced in a direction away from the magnetic sensor 244 from the initial position. However, since the value of the differential pressure (P1-P2) can change according to the flowing state of hot water, the positions of the diaphragm 226 and the magnet 242 change according to the value of the differential pressure (P1-P2).

  The magnetic sensor 244 outputs a detection signal corresponding to the displacement. A control unit (determination unit) (not shown) samples the detection value of the magnetic sensor 244 during filling and calculates the flow rate of hot water flowing through the pipe 32 by integrating the values. When the calculated value reaches the set amount of hot water, energization of the solenoid 118 is stopped, the control valve 60 is closed, and hot water supply is stopped. That is, in this embodiment, the check valve 66 whose opening degree is constant in the fully opened state is used as a fixed orifice, and the flow sensor 68 is made to sense the differential pressure. Then, by integrating the detection values of the flow sensor 68 based on the differential pressure, it is possible to calculate the amount of hot water supplied during hot water filling.

  On the other hand, since the control valve 60 is in the closed state at the time of reheating, both the check valve 62 and the check valve 66 maintain the closed state. On the other hand, since the pump 84 is driven, hot water is led out from the bathtub 13 and flows through the recirculation circuit. As a result, the downstream pressure P2 of the check valve 66 becomes higher than the upstream pressure P1 (P2> P1), and the differential pressure (P2-P1) acts on the diaphragm 226. As a result, the diaphragm 226 is displaced toward the first chamber 232 from the reference position. That is, the magnet 242 is displaced in a direction closer to the magnetic sensor 244 than the initial position. A control unit (determination unit) (not shown) determines whether hot water is circulating in the bathtub 13 based on the detection value of the magnetic sensor 244.

  That is, when the detection value of the magnetic sensor 244 is a value opposite to that when filling the water, that is, a value indicating that the magnet 242 is closer to the magnetic sensor 244 than the initial position, the control unit It is determined that the hot water in the bathtub 13 is circulating in the recirculation circuit (reheating or the reheating function is operating normally). When the detection value of the magnetic sensor 244 is a value indicating that the magnet 242 is in the initial position or is further away from the magnetic sensor 244 than the initial position, the control unit Is determined not to circulate in the recirculation circuit (not replenishing or retreat function is not operating normally).

  That is, the flow sensor 68 functions as a flow sensor for detecting the amount of hot water discharged when filling with water, and also functions as a flow switch for detecting the presence or absence of hot water circulation during reheating. The control unit can also identify whether the detected hot water flow is pouring or circulating. When the flow sensor 68 functions as a flow switch, it is also possible to obtain a guide for the renewal end time based on the circulation duration time. That is, the check valve 66 and the surrounding configuration and the flow sensor 68 in the present embodiment constitute a detection unit for detecting the flowing state of hot water in the hot water supply system.

Next, the operation of the control valve unit 54 will be described.
When the hot water is filled, the solenoid 118 is energized and the control valve 60 is kept fully open. At this time, hot water is introduced from the upstream side into the introduction pipe section 104, and the check valve 62 and the check valve 66 are opened by the water pressure. On the other hand, at the time of such water flow, the primary pressure introduced from the introduction pipe portion 104 is higher than the secondary pressure derived from the lead-out pipe portion 106, so that the atmosphere release valve 64 remains closed. To do.

  On the other hand, when the hot water filling is stopped, the energization to the solenoid 118 is turned off. As a result, the suction force by the solenoid 118 is lost, and the pilot valve body 142 is seated on the pilot valve seat 138 by the biasing force of the spring 154, and the pilot valve 122 is closed. As a result, the main valve 120 is seated on the main valve seat 126, and the control valve 60 is closed.

  At this time, since the introduction of hot water is blocked by the control valve 60, the check valve 62 and the check valve 66 are closed by the urging force of the springs 172 and 180. On the other hand, as long as the device is normal, the pressure introduced from the introduction pipe portion 104 is higher than the pressure between the check valve 62 and the check valve 66, so that the atmosphere release valve 64 remains closed. maintain.

  In the state where hot water is supplied to the bathtub 13 in this way, the primary pressure upstream of the control valve 60 is introduced into the pressure sensing chamber 200 of the air release valve 64 via the pressure detection passage 204. Since this primary pressure is usually greater than the secondary pressure downstream of the control valve 60, the atmosphere release valve 64 remains closed. However, when a negative pressure is generated in the water supply pipe 16 or the hot water supply pipe 25 due to, for example, a power failure or a water stoppage, the air release valve 64 detects the decrease in the primary pressure and opens the valve. The water in the space between them is released to the atmosphere. At this time, if the check valve 66 has become watertight due to some cause such as the biting of foreign matter, the sewage in the bathtub 13 flows back to the atmosphere release valve 64 via the check valve 66 due to the water head pressure. However, since the sewage is released to the atmosphere by the atmosphere release valve 64, it does not flow back to the water supply pipe 16 or the hot water supply pipe 25.

  As described above, according to the present embodiment, the two functions of measuring the amount of pouring water into the bathtub 13 and detecting the circulation operation can be realized by one flow sensor. In the existing hot water supply system, generally, a flow sensor for measuring the amount of pouring water and a flow switch for detecting circulation operation are provided, respectively. According to the present embodiment, they are combined into one differential pressure type flow sensor. It can be combined. Thereby, reduction of a number of parts and simplification of piping connection are realizable, and it can lead to the price reduction of the whole hot water supply system. In addition, the hot water supply apparatus can be reduced in size and weight. Furthermore, since the flow sensor 68 is of the differential pressure type, it is not necessary to expose the rotating parts such as the impeller to the pipe line as in the conventional case. Advantages such as excellent resistance to foreign substances are also obtained.

  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, as shown in FIG. 4, an example in which the magnet 242 to be detected and the support member 240 that supports the magnet 242 are provided in the first chamber 232 has been described. In a modified example, these may be provided in the second chamber 234. However, when the flow sensor 68 is applied to the hot water supply system as shown in the above embodiment, the sewage flowing through the recirculation circuit flows into the downstream side of the check valve 66 and foreign matter enters the second chamber 234. In consideration of the possibility, the first chamber 232 is preferably provided with the magnet 242 and the support member 240 that supports the magnet 242.

  That is, the lead-out pipe section 106 does not constitute a part of the recirculation circuit, and the flow sensor 68 is located at a position slightly away from the recirculation circuit, so that foreign matter can enter the second chamber 234. Sex may not be so high. However, when the magnet 242 and the support member 240 are disposed in the second chamber 234, if a foreign object enters the second chamber 234, the sensitivity of the magnet 242 decreases due to the foreign object, or the support member 240 and the guide portion 246 There is a risk of malfunction due to biting into the sliding part. In this regard, since the check valve 66 is closed during reheating, as long as the hot water supply device is functioning normally, the sewage flows back to the upstream side of the check valve 66, and foreign matter further flows into the first chamber 232. Never invade. Therefore, the magnet 242 and the support member 240 that supports the magnet 242 are preferably provided in the first chamber 232 as in the above embodiment.

  In the above-described embodiment, the example in which the flow sensor 68 is provided so as to sense the differential pressure across the one check valve 66 arranged in the pipe has been described. In a modification, the flow sensor 68 may be provided so that a plurality of check valves arranged in series can sense a differential pressure between the upstream pressure and the downstream pressure of the check valves. For example, in FIG. 4, the first communication path 236 of the flow sensor 68 is connected to the downstream side of the control valve 60 and the upstream side of the check valve 62 (first check valve), and the second communication path 238 is checked. The valve 66 (second check valve) may communicate with the downstream side. The flow sensor 68 detects the flow rate of the fluid (hot water) by sensing the differential pressure between the upstream side of the first check valve and the downstream side of the second check valve arranged in series. May be.

  In the above embodiment, an example in which a diaphragm is used as the pressure-sensitive member has been described. However, other pressure receiving displacement bodies such as a bellows and a piston may be provided, or any movable member that can be moved by a differential pressure may be used. Good. The sensor for detecting the position of the movable member is not limited to a magnetic sensor, and may be another non-contact displacement sensor such as a capacitance type sensor or a contact type sensor. Moreover, although the sensor which detects the displacement amount of the movable member (magnet) displaced with a diaphragm was shown in the said embodiment, you may use the pressure sensor which senses a differential pressure from distortion of a pressure-sensitive member. Specifically, a strain gauge is attached to one side surface of the diaphragm 226 shown in FIG. 4 (for example, the surface on the first chamber 232 side), and the diaphragm 226 according to the differential pressure between the first chamber 232 and the second chamber 234 is attached. You may output the detection signal according to distortion (deformation amount). In this case, the pressure-sensitive member is not limited to a diaphragm, and may be a member that deforms due to a differential pressure to cause distortion. Needless to say, various sensors (differential pressure detection sensors) can be used as long as the differential pressure between the first chamber 232 and the second chamber 234 can be detected.

  The example which applied the control valve unit of this invention to the 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, the working fluid may be other than hot water and may be applied to a fluid circulation device that requires adjustment or blocking of the flow rate of the working fluid.

  In addition, this invention is not limited to the said embodiment and modification, A component can be deform | transformed and embodied in the range which does not deviate from a summary. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. Moreover, you may delete some components from all the components shown by the said embodiment and modification.

  DESCRIPTION OF SYMBOLS 10 Hot water storage unit, 12 Heat pump unit, 13 Bathtub, 14 Hot water storage tank, 15 Karan, 16 Water supply pipe, 24 Heating circulation path, 25 Hot water supply pipe, 26 1st hot water supply pipe, 28 2nd hot water supply pipe, 30, 32 piping, 36 1st 1 mixing valve, 38 second mixing valve, 54 control valve unit, 60 control valve, 62 check valve, 64 atmospheric release valve, 66 check valve, 68 flow sensor, 70 heat exchanger, 72 pump, 80 connecting passage, 82 Circulating passage, 84 Pump, 90 Valve hole, 92 Valve seat, 100 Body, 104 Inlet pipe part, 106 Outlet pipe part, 110 Body, 118 Solenoid, 120 Main valve, 122 Pilot valve, 124 Main valve hole, 126 Main valve Seat, 130 main valve body, 132 diaphragm, 134 back pressure chamber, 40 Pilot valve hole, 142 Pilot valve body, 162 First valve body, 164 Second valve body, 176 Valve hole, 178 Valve seat, 198 Diaphragm, 210 Connection passage, 212 Discharge passage, 214 Valve seat, 216 Valve body, 222 First housing, 224 Second housing, 226 Diaphragm, 232 First chamber, 234 Second chamber, 236 First communication path, 238 Second communication path, 240 Support member, 242 Magnet, 244 Magnetic sensor, 246 Guide part, 248 Disc, 250 spring.

Claims (8)

A flow rate detection unit for detecting the flow rate of fluid flowing through a pipe,
A check valve installed in the pipe to prevent backflow of fluid;
A detection unit that is arranged in parallel with the pipe and detects the flow rate of the fluid by sensing a differential pressure between the upstream pressure and the downstream pressure of the check valve;
A flow rate detection unit comprising: The detector is
A pressure sensing chamber arranged in parallel with the pipe;
The pressure sensing chamber is partitioned into a first chamber communicating with the upstream side of the check valve and a second chamber communicating with the downstream side of the check valve, and an upstream pressure and a downstream pressure of the check valve, A diaphragm that senses and displaces the differential pressure of
A magnet that is integrally displaceable with the diaphragm;
A magnetic sensor that outputs a detection signal corresponding to the displacement of the magnet;
The flow rate detection unit according to claim 1, comprising:   The flow rate detection unit according to claim 2, wherein the diaphragm is disposed so as to be displaceable on both the first chamber side and the second chamber side with respect to an operation reference position.   The flow rate detection unit according to claim 2, wherein the magnet is provided in the first chamber. A hot water supply system comprising: a circulation circuit for circulating hot water in a bathtub; and a hot water supply pipe connected to the circulation circuit for supplying temperature-controlled hot water to the bathtub through the circulation circuit. Configured as part of the detection unit,
The check valve is provided on the upstream side of a connection point with the circulation circuit in the hot water supply pipe,
The detection unit is arranged in parallel with the hot water supply pipe, and calculates the flow rate of hot water flowing through the hot water supply pipe according to the differential pressure when the check valve is opened when hot water is supplied to the bathtub. When the check valve that closes the supply of hot water to the bathtub is closed, a detection signal for determining the presence or absence of hot water circulation in the bathtub is output according to the differential pressure. The flow rate detection unit according to any one of claims 1 to 4. A circulation circuit for circulating hot water in the bathtub;
A hot water supply pipe connected to the circulation circuit to supply conditioned hot water to the bathtub through the circulation circuit;
A check valve provided on the upstream side of the connection point with the circulation circuit in the hot water supply pipe;
A detection unit that is arranged in parallel with the hot water supply pipe, senses a differential pressure between the upstream pressure and the downstream pressure of the check valve, and outputs a detection signal corresponding to the differential pressure;
A determination unit that calculates a fluid flow state based on a detection result of the detection unit;
A hot water supply system comprising: The determination unit
When the check valve is opened to supply hot water to the bathtub, the flow rate of hot water flowing through the hot water supply pipe is calculated based on the detection result of the detection unit,
7. The presence / absence of circulation of hot water in the bathtub is determined based on a detection result of the detection unit when the check valve is closed when supply of hot water to the bathtub is stopped. Hot water system. The detector is
A pressure sensing chamber arranged in parallel with the hot water supply pipe;
The pressure sensing chamber is partitioned into a first chamber communicating with the upstream side of the check valve and a second chamber communicating with the downstream side of the check valve, and an upstream pressure and a downstream pressure of the check valve, A diaphragm that senses and displaces the differential pressure of
A magnet that is integrally displaceable with the diaphragm;
A magnetic sensor that outputs a detection signal corresponding to the displacement of the magnet;
With
The hot water supply system according to claim 6 or 7, wherein the magnet is provided in the first chamber.

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