JP7395184B2 - Water heater - Google Patents

Description

The present invention relates to a water heater.

BACKGROUND ART Conventionally, a water heater is provided with an edge valve unit in a pipe connecting a hot water supply circuit and a circulation heating circuit. The edge valve unit prevents hot water from flowing backward from the circulation heating circuit side to the hot water supply circuit side. The edge valve unit includes a casing including a main channel and a branch channel branching from the main channel. Two check valves are provided in the main flow path in the casing and are biased in the direction of closing the upstream side and the downstream side of the position where the main flow path branches into the branch path from the downstream side. The branch passage is provided with an edge valve that opens the branch passage when the pressure on the circulation heating circuit side increases. As a result, the pressure on the circulation heating circuit side increases relatively, and when hot water crosses the check valve on the downstream side and enters the edge valve unit, the entered hot water flows through a branch path and exits from the edge valve to the outside. is discharged.

As an example of a edge valve unit, a control valve unit is known in which an on-off valve, two check valves, and an atmosphere release valve are assembled in a common cylindrical casing (see, for example, Patent Document 1). In this control valve unit, two check valves are linearly and coaxially assembled into a cylindrical body to form a unit, and the check valve is inserted and fixed into a main flow path in a casing.

JP2018-91396A

However, in the above control valve unit, the body is supported by the casing only on the downstream side of the branch path in the main flow path, so the support position of the check valve on the upstream side and the valve seat provided in the main flow path are different. Since the distance between the valve and the valve is longer, the forward and backward stroke of the check valve had to be lengthened. For this reason, water pressure from the hot water supply circuit is applied to the check valve on the upstream side, causing wobbling of the check valve shaft as it moves downstream, potentially weakening its tight contact with the valve seat in the closed state. there were.

An object of the present invention is to provide a water heater that can maintain close contact with the valve seat of the check valve of the edge valve unit in the closed state.

The water heater according to claim 1 is a water heater, wherein a pipe line connecting a hot water supply circuit and a circulation heating circuit is provided with an edge valve unit for preventing backflow of hot water from the circulation heating circuit side to the hot water supply circuit side. , the edge cutting valve unit has a main flow path that extends linearly from an upstream opening toward a downstream opening in the direction in which hot water flows, and is branched from a branch part provided in the main flow path, and is always kept in the valve opening direction by a spring force. the main flow path and the branch path; a casing in which a first valve seat is provided on the peripheral edge of the upstream opening; a cylindrical part provided in the casing and having the main flow path formed therein; a first check valve that prevents backflow of hot water from the heating circuit side; and a second check valve that is disposed downstream of the first check valve and prevents backflow of hot water from the circulation heating circuit side. and a non-return check inserted into the main flow path from the downstream opening and disposed within the cylindrical portion so that the first check valve faces the first valve seat and can move toward and away from the first valve seat. the check valve unit includes a first member and a second member disposed on the downstream side of the first member, the first member is formed in a cylindrical shape, and the first member is arranged on the upstream side. a first support part that is provided on the inner wall of the first member and that supports the first check valve; a plurality of construction parts supported on the axis of one member; a second valve seat provided on the downstream side of the first support part and in contact with and away from the second check valve; A communication port is provided in the body between the second valve seats and communicates the branch passage with the first member, and the second member includes a second support portion that supports the second check valve. In the check valve unit, the second valve seat is located closer to the second support portion than the branched path, and the plurality of construction portions are located closer to the first valve seat than the branched path. The second valve seat and the plurality of construction parts are supported by the inner wall of the cylindrical part, and the check valve is disposed on the inner wall of the cylindrical part. A fitted portion is provided that fits into a fitting portion provided on the unit and restricts circumferential rotation of the check valve unit with respect to the casing, and the fitting portion A protrusion that protrudes radially outward from the outer circumference of the member and extends parallel to the axial direction of the first member, the fitted portion extending parallel to the axial direction of the casing. It is characterized in that it is a notch or groove that extends and fits into the fitting portion .

The first member of the water heater according to claim 2 includes an annular connecting part that connects with the plurality of construction parts, and the connecting part has a state in which the check valve unit is disposed in the cylindrical part, The cylindrical portion may be in close contact with an inner wall portion on the upstream side of the branch path.

The cylindrical portion of the water heater according to claim 3 includes a cylindrical small diameter portion in which the first member is disposed, and a cylindrical small diameter portion provided downstream of the small diameter portion and having a larger diameter than the small diameter portion. a large diameter part, and a cylindrical medium diameter part provided between the small diameter part and the large diameter part, and on the inside of the cylindrical part, between the large diameter part and the medium diameter part. , a step portion whose diameter decreases radially inward is provided , and the fitted portion is provided in the medium diameter portion and extends parallel to the axial direction of the casing from the step portion to the medium diameter portion. a notch or groove that extends into and fits into the fitting portion, the second member being formed along the inner wall portion of the large diameter portion while disposed within the cylindrical portion; A cylindrical part whose downstream end extends downstream of the medium diameter part, an O-ring disposed downstream of the cylindrical part, and a peripheral edge of the downstream opening of the casing, A cylindrical positioning member is inserted and fixed, and the O-ring is inserted between the downstream end of the cylindrical part and the positioning member, along the inner wall of the downstream opening. It may be clamped from the side and the downstream side.

According to the water heater of the first aspect, since the construction part is located upstream of the branch path, the distance between the first support part and the first valve seat is shortened. As a result, the forward and backward stroke of the first check valve is shortened, so that it is possible to prevent the axis of the first check valve from shifting within the cylindrical portion. Therefore, in the water heater, the edge cutting valve unit can maintain close contact with the first valve seat when the first check valve is in the closed state. Further, since the check valve unit can be prevented from rotating within the cylindrical portion of the casing, the communicating path and the branching path of the first member can be maintained in an overlapping state, and the connection between the inside of the first member and the branching path can be maintained. Communication status can be guaranteed. Thereby, the water heater can improve the performance of discharging backflow water in the branch path when backflow of hot water occurs.

According to the water heater of claim 2, the first support portion is supported from the entire circumference by the upstream inner wall portion of the cylindrical portion via the plurality of construction portions and the connecting portions, so that the shaft of the first check valve Misalignment can be further prevented.

According to the water heater of claim 3 , the fitting portion provided on the outer peripheral portion of the first member extends to the downstream end of the first member, so that the downstream end of the first member has a circular shape. Since a portion of the portion protrudes outward in the radial direction, the shape is not a perfect circle. Therefore, in the present application, the fitting portion is covered from the downstream side by a second member located downstream of the first member, and the O-ring is sandwiched between the second member and the positioning member. Therefore, the sealing performance by the O-ring can be ensured.

1 is a perspective view of a water heater 1. FIG. 1 is an internal configuration diagram of a water heater 1. FIG. FIG. 2 is a perspective view of the edge valve unit 2. FIG. FIG. 4 is a sectional view taken along the line II shown in FIG. 3; 4 is a sectional view taken along the line II-II shown in FIG. 3. FIG. 5 is a partially enlarged view of the upper portion of the edge valve unit 2 shown in FIG. 4. FIG. FIG. 6 is an exploded perspective view of the third casing 5, the check valve unit 20, and the lid member 57.

Embodiments of the present invention will be described below. The structure of the device described below is merely an illustrative example and is not intended to be limiting unless specifically stated. The drawings are used to explain technical features that can be adopted by the present invention.

The configuration of the water heater 1 will be briefly described with reference to FIGS. 1 and 2. As shown in FIG. 1, the water heater 1 includes a housing 1A and a lid 1B. A water supply connection port 37, a hot water supply connection port 36, a gas connection port 38, and a drain port 39 shown in FIG. 2 are provided at the bottom of the housing 1A. When the lid 1B is removed from the front of the housing 1A, the inside of the housing 1A is exposed. As shown in FIG. 2, a hot water supply circuit 11, a circulation heating circuit 12, a hot water supply pipe 206, a border valve unit 2, and the like are provided inside the housing 1A. Note that FIG. 2 illustrates the arrangement of each component within the casing 1A for the sake of clarity and convenience, and the orientation of each piping is partially different from the actual orientation of the piping.

The hot water supply circuit 11 includes an inlet pipe 101, a hot water supply burner 102, a primary heat exchanger 103, a secondary heat exchanger 104, an outlet pipe 105, a branch pipe 106, and the like. A hot water burner 102 , a primary heat exchanger 103 , and a secondary heat exchanger 104 are provided within the combustion chamber 8 . Water flowing in from the water supply connection port 37 flows through the inflow pipe 101, and then flows through the secondary heat exchanger 104 and the primary heat exchanger 103 in this order. The primary heat exchanger 103 recovers sensible heat in the combustion exhaust gas from the hot water supply burner 102, and the secondary heat exchanger 104 recovers latent heat in the combustion exhaust gas from the hot water supply burner 102 to heat the flowing water. The tapping pipe 105 is connected between the outlet of the primary heat exchanger 103 and the connection port 35 (see FIG. 3) of the edge valve unit 2, which will be described later. The hot water heated in the primary heat exchanger 103 and the secondary heat exchanger 104 flows through the hot water outlet pipe 105 and is supplied to the outside from the hot water supply connection port 36 via the edge valve unit 2 (see arrow B in FIG. 3). ). The branch pipe 106 branches on the upstream side of the inflow pipe 101 and is connected to a connection port 67 (see FIG. 3) of an inflow pipe 633 of the edge valve unit 2, which will be described later.

The circulation heating circuit 12 includes a bath return pipe 201, a bath outgoing pipe 202, a bath burner 203, a bath primary heat exchanger 204, a bath secondary heat exchanger 205, a hot water supply pipe 206, a pump 207, and the like. A bath burner 203 , a bath primary heat exchanger 204 , and a bath secondary heat exchanger 205 are provided within the combustion chamber 8 . Bath return pipe 201 is connected between the downstream end of piping 13 extending from bathtub 9 and the inlet of bath secondary heat exchanger 205 . The pump 207 is provided in the middle of the bath return pipe 201. The bath primary heat exchanger 204 mainly recovers sensible heat in the combustion exhaust from the bath burner 203, and the bath secondary heat exchanger 205 mainly recovers latent heat in the combustion exhaust from the bath burner 203. Heat the running water. The bath pipe 202 is connected between the outlet of the bath primary heat exchanger 204 and the upstream end of the piping 14 extending from the bathtub 9. By driving the pump 207, hot water in the bathtub 9 flows in the order of the piping 13, the bath return pipe 201, the bath secondary heat exchanger 205, the bath primary heat exchanger 204, the bath outgoing pipe 202, and the piping 14, and is circulated with the bathtub 9. It circulates between the heating circuits 12.

The hot water supply pipe 206 is provided between the hot water supply circuit 11 and the circulation heating circuit 12, and supplies hot water from the hot water supply circuit 11 to the circulation heating circuit 12. The upstream end of the hot water supply pipe 206 is connected to a connection port 58 of the edge valve unit 2, which will be described later. The downstream end of the hot water supply pipe 206 is connected to the bath return pipe 201 upstream of the pump 207 . The edge valve unit 2 is provided in the hot water supply pipe 206. The edge valve unit 2 prevents hot water from flowing backward from the circulation heating circuit 12 side to the hot water supply circuit 11 side.

Gas flows into the gas pipe 7 from the gas connection port 38 and is supplied to the hot water supply burner 102 and the bath burner 203 in the combustion chamber 8, respectively. Overflow water and drain water are discharged from the drain port 39. The overflow water is hot water that flows back into the edge valve unit 2 from the circulation heating circuit 12 via the hot water supply pipe 206, flows through an overflow pipe 110 (described later), and is discharged to the outside from the drain port 39. Drain water is generated by the secondary heat exchanger 104 and the bath secondary heat exchanger 205.

The structure of the edge valve unit 2 will be explained with reference to FIGS. 3 to 6. As shown in FIGS. 3 and 4, the edge valve unit 2 includes a second casing 4, a third casing 5, and a fourth casing 6 (hereinafter collectively referred to as casings 3 to 6) connected to the first casing 3. ), a check valve unit 20 , a third check valve 72 , and an edge valve 73 . Casings 3 to 6 are made of resin. That is, the edge valve unit 2 is composed of a second casing 4, a third casing 5, and a fourth casing 6, and the first casing 3 connected to the second casing 4 is located downstream of the hot water outlet pipe 105 of the hot water supply circuit 11. It forms part of the side (see Figure 2).

The first casing 3 is formed in a substantially T-shape tilted approximately 90° clockwise when viewed from the right side, and includes a horizontal portion 31 (see FIG. 3) and a vertical portion 32. The lateral portion 31 is formed into a substantially cylindrical shape extending in the front-rear direction, and the rear end portion is closed. A connection port 35 is provided at the front end of the lateral portion 31 . The connection port 35 opens toward the front. A flow path 91 is provided inside the lateral portion 31 . The flow path 91 extends rearward from the connection port 35. The downstream end of the outlet pipe 105 (see FIG. 2) is connected to the connection port 35.

The vertical portion 32 is formed into a substantially cylindrical shape extending in the vertical direction. A substantially middle portion of the vertical portion 32 in the vertical direction is connected to the rear portion of the left surface of the horizontal portion 31 . A hot water supply connection port 36 is provided at the lower end of the vertical portion 32 . The hot water supply connection port 36 opens downward. The hot water supply connection port 36 is provided at the bottom of the water heater 1. A pipe (not shown) connected to a faucet is connected to the hot water supply connection port 36. A flow path 92 (see FIG. 4) is provided inside the vertical portion 32. The flow path 92 extends upward from the hot water supply connection port 36. The flow path 92 communicates with the rear end portion of the flow path 91 of the lateral portion 31 at a substantially intermediate portion in the vertical direction.

The second casing 4 has a substantially T-shape when viewed from the right side, and includes a vertical portion 41 and a horizontal portion 42 . The vertical portion 41 is formed into a substantially cylindrical shape extending in the vertical direction. The lower end of the vertical section 41 is fixed to the upper end of the vertical section 32 of the first casing 3 with two screws 301 . A flow path 93 (see FIG. 4) is provided inside the vertical portion 41. The flow path 93 extends in the vertical direction. A metal filter 44 is provided at the upper end of the flow path 93 . The lateral portion 42 is formed into a substantially cylindrical shape extending in the front-rear direction. The upper end portion of the vertical portion 41 is connected to the lower portion of the horizontal portion 42 at an approximately intermediate portion in the longitudinal direction. A flow path 94 is provided inside the lateral portion 42 . The flow path 94 extends in the front-back direction. The rear end of the flow path 94 communicates with the upper end of the flow path 93 . A solenoid valve 45 is provided at the rear end of the lateral section 42 . The solenoid valve 45 opens and closes the flow path 94 by energizing and de-energizing the electromagnet 451. A water amount sensor 46 is provided on the front end side of the flow path 94 . The water amount sensor 46 measures the amount of hot water flowing through the flow path 94 .

The third casing 5 includes an upper lateral section 51 , a lower lateral section 52 , a longitudinal section 53 , and a connecting section 54 . The upper lateral part 51 has a substantially cylindrical shape extending in the front-rear direction, and is provided coaxially with the lateral part 42 of the second casing 4 . A flow path 95 (see FIG. 4) is provided inside the upper lateral portion 51. The flow path 95 extends in the front-rear direction.

The upper lateral portion 51 includes a small diameter portion 511, a medium diameter portion 512, and a large diameter portion 513 in order from the rear to the front. The small diameter portion 511 forms a portion from the rear end of the upper lateral portion 51 to approximately the middle portion in the longitudinal direction. A branch portion 951 is provided at the lower front end side of the inner wall surface of the small diameter portion 511 (see FIG. 4). The branch portion 951 branches from the flow path 95 to a flow path 97 of the vertical portion 53, which will be described later. An opening 60 (see FIGS. 6 and 7) through which hot water flows from the second casing 4 is provided at the rear end of the small diameter portion 511. A first valve seat 515 (see FIGS. 4 and 6) is provided at the peripheral edge of the opening 60. The first valve seat 515 is formed into a substantially annular shape with a central portion passing through it. A valve body 701 (see FIG. 6) of a first check valve 70 (described later) comes into contact with the front surface of the first valve seat 515. The rear end of the small diameter portion 511 is fixed to the front end of the lateral portion 42 of the second casing 4 with two screws 302 .

The large diameter portion 513 forms the front end side portion of the upper lateral portion 51 and is larger than the diameter of the small diameter portion 511 . An opening 59 is provided at the front end of the large diameter portion 513 (see FIG. 7). A pair of fixing cylindrical portions 517 are provided on both left and right sides of the opening 59. Each of the pair of fixing cylindrical portions 517 extends in the front-rear direction and is formed into a substantially cylindrical shape. A fixing hole 518 extending rearward from the front end is provided in each of the pair of fixing cylinder parts 517. A check valve unit 20, which will be described later, is inserted into the opening 59 from the front inside, and the lid member 57 is fastened to the pair of fixing holes 518 with two screws 303.

The medium diameter portion 512 forms a portion between the small diameter portion 511 and the large diameter portion 513. The medium diameter portion 512 has a larger diameter than the small diameter portion 511 and has a smaller diameter than the large diameter portion 513. A communication hole 952 is provided in the lower part of the inner wall surface of the medium diameter portion 512 . The flow path 95 communicates with an upper end portion of a communication path 541 of the connecting portion 54, which will be described later, via a communication hole 952. Inside the upper lateral portion 51, a step portion 519 is provided between the medium diameter portion 512 and the large diameter portion 513 (see FIG. 7). The stepped portions 519 contract inward in the radial direction and face each other toward the front. A fitting groove 516 is provided on the left front end side of the inner wall surface of the medium diameter portion 512 . The fitting groove 516 extends linearly from the front end of the medium diameter portion 512 toward the rear. The front end of the fitting groove 516 penetrates forward at the stepped portion 519.

The lower lateral section 52 is arranged below the upper lateral section 51 (see FIGS. 3 and 4). The lower lateral portion 52 is formed in a substantially cylindrical shape extending parallel to the upper lateral portion 51 and in the front-rear direction. A flow path 96 is provided inside the lower lateral portion 52 . The flow path 96 extends in the front-rear direction. The lower lateral portion 52 includes a small diameter portion 521 and a large diameter portion 522 in order from the rear to the front. The small diameter portion 521 is disposed below the medium diameter portion 512 of the upper lateral portion 51 and has substantially the same shape as the medium diameter portion 512 . The large diameter portion 522 is disposed below the large diameter portion 513 of the upper lateral portion 51 and is larger than the diameter of the small diameter portion 521 . A connection port 58 is provided at the front end of the large diameter portion 522 . The connection port 58 opens toward the front. The upstream end of a hot water supply pipe 206 (see FIG. 2) extending from the circulation heating circuit 12 side is connected to the connection port 58. A communication hole 961 (see FIG. 4) is provided in the upper part of the inner wall surface of the small diameter portion 521. The flow path 96 communicates with a lower end portion of a communication path 541 of the connecting portion 54, which will be described later, via a communication hole 961.

The connecting portion 54 is provided between the upper lateral portion 51 and the lower lateral portion 52, and connects the upper lateral portion 51 and the lower lateral portion 52 to each other. The connecting portion 54 is provided with a communication path 541 (see FIG. 4) that extends in the vertical direction. The upper end of the communication path 541 communicates with the flow path 95 via a communication hole 952 provided in the inner wall of the medium diameter portion 512 of the upper lateral portion 51 . The lower end of the communication passage 541 communicates with the flow passage 96 via a communication hole 961 provided in the inner wall of the small diameter portion 521 of the lower lateral portion 52 .

The vertical portion 53 extends downward from the lower front portion of the small diameter portion 511 of the upper horizontal portion 51 and is formed in a substantially cylindrical shape. A flow path 97 is provided inside the vertical portion 53 . The flow path 97 extends in the vertical direction. The upper end of the flow path 97 communicates with the flow path 95 via a branch portion 951 provided on the inner wall of the small diameter portion 511 . A communication hole 971 is provided in the inner wall of the vertical section 53 at a position facing the rear end of the lower horizontal section 52 . The flow path 97 communicates with the flow path 96 via the communication hole 971.

The fourth casing 6 includes a vertical section 61, a valve storage section 62, and a lid section 63. The vertical portion 61 has a substantially cylindrical shape extending in the vertical direction. A flow path 98 is provided inside the vertical portion 61 . The flow path 98 extends in the vertical direction. A flow path 99 (see FIGS. 4 and 5) is provided at the lower end of the vertical section 61. The flow path 99 extends rightward from the lower end of the flow path 98. The upper end of the vertical part 61 is fixed to the lower end of the vertical part 53 of the third casing 5 and the lower part of the lower horizontal part 52 with two screws 304 . The flow path 98 communicates with the flow path 97 in the longitudinal section 53 of the third casing 5 .

The valve storage portion 62 is integrally provided at the lower part of the right side surface of the vertical portion 61 (see FIG. 4). The valve accommodating portion 62 has a substantially rectangular shape with a right side surface tilted clockwise, and is formed in a box shape with an open right side surface. A communication hole 621 is provided on the inner left wall surface of the valve storage portion 62 . The inside of the valve storage portion 62 communicates with the right end portion of the flow path 99 via the communication hole 621. A drain pipe 632 (see FIG. 3) is provided on the front side of the valve housing portion 62 and on the side surface facing diagonally downward. The inside of the drain pipe 632 communicates with the inside of the valve storage section 62 . A connection port 66 is provided at the front end of the drain pipe 632. The connection port 66 opens toward the front. The upstream end of the overflow pipe 110 (see FIG. 2) is connected to the connection port 66. The downstream end of the overflow pipe 110 is connected to the drain port 39 (see FIG. 2) at the bottom of the housing 1A.

The lid portion 63 is formed in a substantially rectangular shape tilted clockwise by approximately 45 degrees when viewed from the right side, and is fixed with four screws 305 so as to close the right side surface where the valve storage portion 62 opens. A circular recess 631 is provided approximately at the center of the lid 63 . The recessed portion 631 is formed by recessing the left surface of the lid portion 63 toward the right. An inflow pipe 633 is bent forward and provided on the right side of the lid part 63. The inside of the inflow pipe 633 communicates with the inside of the recess 631 . A connection port 67 is provided at the front end of the inflow pipe 633 . The connection port 67 opens toward the front. A downstream end of a branch pipe 106 (see FIG. 2) extending from the hot water supply circuit 11 is connected to the connection port 67.

The structure of the check valve unit 20 will be explained with reference to FIGS. 6 and 7. As shown in FIG. 6, the check valve unit 20 is inserted into the flow path 95 from the opening 59 of the upper lateral portion 51 of the third casing 5. As shown in FIG. 7, the check valve unit 20 includes a first member 21 and a second member 22 in order from the rear.

The structure of the first member 21 will be explained. The first member 21 is formed into a substantially cylindrical shape extending in the front-rear direction. The first member 21 includes, in order from the front side, a front body part 24, a rear body part 25, and a valve support part 26. The front body portion 24 is formed into a substantially cylindrical shape. A protrusion 242 is provided on the front end side of the left side of the outer peripheral surface of the front trunk 24 . The protrusion 242 protrudes leftward and extends linearly rearward from the front end of the front trunk 24 . A second valve seat 241 is provided at the rear end portion of the front body portion 24 . The second valve seat 241 is formed into a substantially annular shape with a central portion passing through it. A valve body 711 of a second check valve 71, which will be described later, contacts the front surface of the second valve seat 241 from the front. A communication port 243 having a substantially rectangular shape when viewed from the bottom is provided on the rear side of the lower portion of the front body portion 24 . A slit 245 is provided on the front side of the lower part of the front trunk section 24 . The slit 245 extends rearward from the front end of the front trunk 24 and communicates with the communication port 243 . A protrusion 275 provided on the second member 22 and described later is inserted into the slit 245 from the front and fitted therein. A claw portion 246 is provided at the right end of the pair of opposing ends forming the slit 245 . The claw portion 246 projects obliquely upward from the inside of the front body portion 24 . The rear trunk 25 coaxially extends rearward from the rear end of the front trunk 24 and is formed into a substantially cylindrical shape. A communication port 251 having a substantially rectangular shape when viewed from the bottom is provided on the lower side of the rear body portion 25 . A groove 29 having a semicircular arc cross section is provided along the outer periphery of the boundary between the front body part 24 and the rear body part 25 . A resin O-ring 81 having an annular shape when viewed from the front is attached to the groove 29 .

The valve support portion 26 is provided at the rear end portion of the rear body portion 25 . The valve support part 26 includes a connecting part 261, three construction parts 262 (two in FIG. 6, only one in FIG. 7), and an annular support part 263. The connecting portion 261 is formed in an annular shape. The three construction parts 262 each extend in the shape of a beam from three positions equally spaced in the circumferential direction on the inner edge of the connecting part 261 toward the central axis. The annular support portion 263 is arranged at the axis of the connecting portion 261 . The annular support portion 263 extends in the front-rear direction and is formed into a substantially cylindrical shape having a diameter shorter than that of the connecting portion 261. One end of each of the three construction parts 262 is connected to the outer peripheral part of the annular support part 263 . Therefore, the annular support part 263 is supported on the axis of the connecting part 261 by the three construction parts 262.

The valve shaft 702 of the first check valve 70 is inserted into the annular support portion 263 in the front-rear direction. A valve body 701 is provided at the rear end of the valve shaft 702 . The valve body 701 is formed into a substantially cylindrical shape having a larger diameter than the valve shaft 702. The valve body 701 is supported by the annular support portion 263 via the valve shaft 702 so as to be stably movable in the front-rear direction. Thereby, the valve body 701 is arranged so as to be able to come into contact with and separate from the first valve seat 515 provided at the rear end of the upper lateral portion 51 of the third casing 5. A cylindrical spring 705 is attached to the outside of the valve shaft 702. The front end of the spring 705 comes into contact with the rear surface of the three construction parts 262, and the rear end of the spring 705 comes into contact with the front surface of the valve body 701. As a result, the valve body 701 is always urged by the spring force of the spring 705 in a direction (backward) in which it comes into contact with the first valve seat 515 . Therefore, the first check valve 70 blocks hot water flowing backward through the flow path 95 from the front to the rear using the spring force of the spring 705.

The structure of the second member 22 will be explained. The second member 22 is arranged on the front side (downstream side) of the first member 21 . The second member 22 includes a valve support portion 27 . Like the valve support part 26 of the first member 21, the valve support part 27 includes a connecting part 271, three construction parts 272 (only two are shown in FIG. 6), an annular support part 273, and a cylindrical part 274. Be prepared. The connecting portion 271 is formed in an annular shape. The three construction parts 272 extend in a beam shape from three positions equally spaced in the circumferential direction on the inner edge of the connecting part 271 toward the central axis. The annular support portion 273 is arranged at the axis of the connecting portion 271 . The annular support portion 273 extends in the front-rear direction and is formed in a substantially cylindrical shape with a diameter shorter than that of the connecting portion 271, and is connected to one end of each of the three construction portions 272 at its outer peripheral portion. Therefore, the annular support part 273 is supported on the axis of the connecting part 271 by the three construction parts 272.

The valve shaft 712 of the second check valve 71 is inserted into the annular support portion 273 in the front-rear direction. A valve body 711 is provided at the rear end of the valve shaft 712 . The valve body 711 is formed into a substantially cylindrical shape having a longer diameter than the valve shaft 712. The valve body 711 is supported by the annular support portion 273 via the valve shaft 712 so as to be stably movable in the front-rear direction. Therefore, the valve body 711 is arranged so as to be able to come into contact with and separate from the second valve seat 241 of the first member 21. A cylindrical spring 715 is attached to the outside of the valve shaft 712. The front end of the spring 715 contacts the rear surface of the three construction parts 272, and the rear end of the spring 715 contacts the front surface of the valve body 711. As a result, the valve body 711 is always urged by the spring force of the spring 715 in the direction (backward) into contact with the second valve seat 241 . The cylindrical portion 274 protrudes forward from the outer periphery of the front surface of the connecting portion 271 and is formed in a substantially annular shape when viewed from the front. The front end surfaces of the cylindrical portion 274 face forward. A protruding portion 275 is provided at a lower portion of the outer peripheral surface of the connecting portion 271 . The protrusion 275 protrudes downward.

The structure of the lid member 57 will be explained. The lid member 57 has a substantially circular disk shape when viewed from the front. Fixing holes 571 penetrating in the front-rear direction are provided at both left and right ends of the lid member 57, respectively. A substantially cylindrical cylindrical portion 572 that protrudes rearward is provided on the rear surface of the lid member 57 . The cylindrical portion 572 includes a large diameter portion 573 and a small diameter portion 574 (see FIG. 6). The large diameter portion 573 is provided on the front side of the cylindrical portion 572, and the small diameter portion 574 is provided on the rear side of the cylindrical portion 572. A stepped portion 575 (see FIG. 6) is provided between the large diameter portion 573 and the small diameter portion 574. The step portions 575 face each other toward the rear. A resin O-ring 82 is attached to the outside of the small diameter portion 574. O-ring 82 abuts against stepped portion 575 .

A method for attaching the check valve unit 20 to the upper lateral portion 51 of the third casing 5 will be described with reference to FIGS. 6 and 7. As shown in FIG. 7, first, the second member 22 is inserted inside the front body portion 24 of the first member 21 and assembled. At this time, the protrusion 275 provided on the second member 22 is inserted into the slit 245 provided at the lower part of the front body portion 24 of the first member 21 . The protruding portion 275 fits into the slit 245, and the claw portion 246 engages with the protruding portion 275. Thereby, the second member 22 can be prevented from rotating inside the front trunk section 24 of the first member 21. The valve body 711 of the second check valve 71 that protrudes from the rear end side of the second member 22 contacts the second valve seat 241 provided inside the first member 21 from the front. In this way, the check valve unit 20 is completed.

Next, the check valve unit 20 is inserted into the upper lateral part 51 through the opening 59. At this time, the protrusion 242 provided on the outer circumferential surface of the first member 21 is inserted from the front end of the fitting groove 516 provided in the inner step 519 of the upper lateral portion 51 and pushed backward. The protrusion 242 fits into the fitting groove 516. The first member 21 is arranged within the upper lateral section 51 . In the upper lateral portion 51 , the valve support portion 26 of the first member 21 is arranged on the inner wall surface upstream of the flow path 97 . The valve body 701 of the first check valve 70 contacts the first valve seat 515 provided at the rear end of the upper lateral portion 51 (see FIG. 6). Thereby, the check valve unit 20 is arranged within the upper lateral part 51.

Finally, the lid member 57 is fixed to the opening 59 of the upper lateral part 51. At this time, the cylindrical portion 572 of the lid member 57 is inserted into the upper lateral portion 51 from the opening 59. In the upper lateral portion 51 , the O-ring 82 is held between the stepped portion 575 of the cylindrical portion 572 and the front end surface of the cylindrical portion 274 of the second member 22 . The outer periphery of the rear surface of the lid member 57 is brought into contact with the rear end surface of the large diameter section 513 of the upper lateral section 51, and the pair of fixing holes 571 provided in the lid member 57 are provided on the front end side of the large diameter section 513. It is positioned in the pair of fixing holes 514 and fixed by fastening the two screws 303. Thereby, the lid member 57 is fixed so as to close the opening 59 of the upper lateral section 51, and the attachment of the check valve unit 20 to the upper lateral section 51 is completed.

As shown in FIG. 6, when the check valve unit 20 is disposed in the upper horizontal section 51, the communication port 251 of the rear body section 25 of the first member 21 is connected to the flow path 97 side located below. directed towards. As a result, the communication port 251 and the flow path 97 overlap, so that the inside of the first member 21 and the flow path 97 communicate with each other. Further, the communication port 243 of the front body portion 24 of the first member 21 is directed toward the communication path 541 of the connecting portion 54 located below. As a result, the communication port 243 and the communication path 541 overlap, so that the inside of the first member 21 and the communication path 541 communicate with each other.

As shown in FIG. 4 , the third check valve 72 is provided in the flow path 96 inside the small diameter portion 521 of the lower lateral portion 52 of the third casing 5 . Although not described in detail, the third check valve 72 has the same structure as the first check valve 70 and the second check valve 71. The third check valve 72 blocks hot water flowing backward from the flow path 96 toward the flow path 97 of the vertical portion 53 and hot water flowing backward from the flow path 96 toward the communication path 541 using a spring force.

The edge valve 73 is a well-known diaphragm valve, and includes a diaphragm membrane 731 and a spring 732. The spring 732 is arranged inside the flow path 99 provided at the lower end of the vertical section 61 of the fourth casing 6 . The diaphragm membrane 731 is housed inside the valve housing part 62 and is arranged toward the left side of the recessed part 631 of the lid part 63. The edge valve 73 is always biased in the valve-opening direction by the spring force of the spring 732. When water flows into the recess 631 from the branch pipe 106 extending from the hot water supply circuit 11 through the inflow pipe 633 (see FIG. 3) (see arrow D in FIG. 3), back pressure is generated against the diaphragm membrane 731. It takes. The diaphragm membrane 731 receives back pressure from the water and presses down the spring 732. Therefore, the edge cutting valve 73 is biased in the valve closing direction against the spring force of the spring 732 and is closed.

The flow of hot water in the edge valve unit 2 will be explained with reference to FIGS. 3 to 5. First, the case where hot water supplied from the hot water supply circuit 11 is supplied to the circulation heating circuit 12 will be described. A control unit (not shown) of the water heater 1 excites the electromagnet 451 of the second casing 4 and opens the electromagnetic valve 45. Hot water flowing from the hot water supply circuit 11 through the hot water outlet pipe 105 flows into the flow path 91 of the first casing 3 from the connection port 35 (see arrow A shown in FIG. 3), and flows along the flow paths 92 and 93 (see arrow A shown in FIG. 3). 4). Since the electromagnetic valve 45 is open, hot water passes through the filter 44 and flows into the flow path 94 of the second casing 4. Hot water flows forward through the flow path 94, flows into the flow path 95 of the third casing 5, and passes through the first check valve 70. The hot water flows forward through the channel 95, and some of the hot water branches at the branching portion 951 and flows downward through the channel 97 of the vertical section 53. The remaining hot water flows forward through the flow path 95. Hot water flowing forward through the flow path 95 passes through the second check valve 71 and flows into the communication path 541 of the connecting portion 54 via the communication hole 952 . Hot water flows downward through the communication path 541.

The hot water that has flowed downward through the flow path 97 flows through the flow paths 98 and 99 in the vertical portion 61 of the fourth casing 6 and flows into the inside of the valve housing portion 62 . As mentioned above, the edge cutter valve 73 receives back pressure of water from the hot water supply circuit 11 and is biased in the valve closing direction against the spring force. is blocked by Therefore, hot water flowing downward through the flow path 97 flows into the flow path 96 of the lower lateral portion 52 via the communication hole 971. Hot water flows forward through the flow path 96 and passes through the third check valve 72 (see arrow C shown in FIG. 3). In this way, hot water is supplied from the connection port 58 to the circulation heating circuit 12 side via the hot water supply pipe 206 (see FIG. 2).

Next, a case where hot water flows backward from the circulation heating circuit 12 side to the hot water supply circuit 11 side will be described. For example, when the pressure on the circulation heating circuit 12 side becomes higher than the pressure on the hot water supply circuit 11 side to some extent, the spring force in the edge cutter valve 73 overcomes the back pressure on the hot water supply circuit 11 side. Therefore, the edge valve 73 is opened by the spring force. When the pressure on the circulation heating circuit 12 side increases, the hot water in the circulation heating circuit 12 may flow into the flow path 96 from the connection port 58 via the hot water supply pipe 206 and flow backward. Since the third check valve 72 is provided in the flow path 96 , the hot water that flows backward through the flow path 96 is blocked by the third check valve 72 .

Even if the hot water flowing backward through the flow path 96 exceeds the third check valve 72, the flow path 97 in the vertical portion 53 of the third casing 5 and the flow path in the vertical portion 61 of the fourth casing 6 98 both extend in the vertical direction. Therefore, the edge valve unit 2 can cause the hot water that has exceeded the third check valve 72 to fall along the flow paths 97 and 98. The hot water that has fallen along the channels 97 and 98 flows through the channel 99 to the right. As described above, since the border valve 73 is open, the hot water that has flowed through the channel 99 passes through the border valve 73 and is discharged as overflow water from the drain pipe 632 (see arrow E shown in FIG. 3). The overflow water is discharged to the outside from the drain port 39 via the overflow pipe 110 (see FIG. 2).

Then, when the pressure difference between the circulation heating circuit 12 side and the hot water supply circuit 11 side becomes even larger, the hot water that has flowed backward through the flow path 96 will forcefully cross the third check valve 72, and while maintaining its momentum, the hot water will flow back through the flow path 96. , 98 may be infiltrated. Therefore, in the third casing 5 of the edge valve unit 2, a height difference is formed between the flow path 95 and the flow path 96 via the flow path 97 and the communication path 541. Therefore, even if the pressure on the circulation heating circuit 12 side increases and the hot water exceeds the third check valve 72 in the flow path 96, its force weakens until it ascends through the flow path 97 and the communication path 541, respectively. It will be done. The hot water that has flowed into the flow path 97 beyond the third check valve 72 falls along the flow paths 97 and 98 without reaching the flow path 95 of the upper lateral portion 51 . On the other hand, even if the hot water that has flowed into the communication path 541 beyond the third check valve 72 reaches the flow path 95, it is blocked by the second check valve 71. Therefore, the edge valve unit 2 can reliably prevent hot water flowing back from the circulation heating circuit 12 side from entering the hot water supply circuit 11 side.

The support structure of the first check valve 70 and the second check valve 71 by the check valve unit 20 and its effects will be described with reference to FIGS. 6 and 7. As shown in FIG. 6 , within the upper lateral portion 51 , the valve support portion 26 of the first member 21 of the check valve unit 20 is located upstream of the flow path 97 . Thereby, the first check valve 70 supported by the valve support part 26 can be brought closer to the first valve seat 515 side in the upper lateral part 51. Thereby, the edge cutting valve unit 2 can shorten the advancing and retracting stroke of the valve body 701 of the first check valve 70, so that it is possible to prevent the axis shift of the first check valve 70 within the upper lateral portion 51. Further, the annular connecting portion 261 of the valve support portion 26 is in close contact with the inner wall portion of the cylindrical upper horizontal portion 51 on the upstream side of the flow path 97 . As described above, the connecting portion 261 supports the annular support portion 263 via the three construction portions 262. Thereby, the annular support part 263 is supported from the entire circumference by the upstream inner wall part of the upper lateral part 51 via the connecting part 261 and the three construction parts 262. Therefore, the edge valve unit 2 can more effectively prevent the axis shift of the first check valve 70 within the upper lateral portion 51.

Further, the protrusion 242 provided on the left side of the outer peripheral surface of the first member 21 fits into the fitting groove 516 provided on the left side of the inner wall surface of the upper lateral section 51. Thereby, the check valve unit 20 can be prevented from rotating in the circumferential direction within the upper lateral portion 51. Therefore, the edge-cutting valve unit 2 can maintain a state in which the communication port 251 of the first member 21 and the flow path 97 overlap, so that a state of communication between the inside of the first member 21 and the flow path 97 can be ensured. Therefore, the water heater 1 can improve the discharge performance of backflow water in the flow path 97 when backflow of hot water occurs.

Furthermore, since the protrusion 242 extends to the downstream end of the front trunk 24 of the first member 21, a portion of the circular portion of the downstream end of the first member 21 protrudes radially outward. It becomes the shape. For this reason, the downstream end of the first member 21 does not have a perfect circular shape. Therefore, in this embodiment, the protrusion 242 is covered by the second member 22 from the downstream side. Further, the O-ring 82 is sandwiched between the downstream end of the second member 22 and the stepped portion 575 of the cylindrical portion 572 of the lid member 57. Thereby, the edge valve unit 2 can ensure the sealing performance by the O-ring 82.

In the above description, the hot water supply pipe 206 is an example of the "pipe line" of the present invention. The flow path 95 is an example of the "main flow path" of the present invention. The opening 60 is an example of the "upstream opening" of the present invention, and the opening 59 is an example of the "downstream opening" of the present invention. The flow path 97 is an example of a "branch path" according to the present invention. The third casing 5 is an example of the "casing" of the present invention. The upper lateral part 51 is an example of the "cylindrical part" of the present invention. The annular support portion 263 is an example of the “first support portion” of the present invention. The rear body portion 25 is an example of the “body portion” of the present invention. The annular support portion 273 is an example of the “second support portion” of the present invention. The protrusion 242 is an example of the "fitting part" of the present invention, and the fitting groove 516 is an example of the "fitting part" of the present invention. The cylindrical portion 572 of the lid member 57 is an example of the "positioning member" of the present invention.

As described above, the water heater 1 of the above embodiment includes the edge cutoff valve unit 2 in the hot water supply pipe 206 that connects the hot water supply circuit 11 and the circulation heating circuit 12. The edge valve unit 2 prevents hot water from flowing backward from the circulation heating circuit 12 side to the hot water supply circuit 11 side. The edge valve unit 2 includes a third casing 5 and a check valve unit 20. The third casing 5 includes a flow path 95, a flow path 97, and a first valve seat 515. The flow path 95 extends linearly from the opening 60 on the upstream side in the direction in which hot water flows toward the opening 59. The flow path 97 is branched from a branch portion 951 provided in the flow path 95 . A border valve 73 is provided in the flow path 97 . The edge cutting valve 73 is always urged in the valve opening direction by a spring force, and is urged in the valve closing direction against the spring force by receiving back pressure from the hot water supply circuit 11. A first valve seat 515 is provided at the periphery of the opening 60 . The third casing 5 includes a cylindrical upper transverse portion 51 . A flow path 95 is formed within the upper lateral section 51 . The check valve unit 20 supports a first check valve 70 and a second check valve 71. The first check valve 70 comes into contact with and separates from the first valve seat 515 to prevent backflow of hot water from the circulation heating circuit 12 side. The second check valve 71 is arranged downstream of the first check valve 70 and prevents hot water from flowing backward from the circulation heating circuit 12 side. The check valve unit 20 is inserted into the flow path 95 through the opening 59 so that the first check valve 70 can move toward and away from the first valve seat 515, and is disposed within the upper horizontal section 51. be done.

The check valve unit 20 includes a first member 21 and a second member 22. The second member 22 is arranged downstream of the first member 21 . The first member 21 is formed into a cylindrical shape. The first member 21 includes an annular support portion 263, three construction portions 262, a second valve seat 241, and a communication port 251. The annular support portion 263 is provided upstream of the first member 21 and supports the first check valve 70 . The three construction portions 262 extend in the axial direction from three locations spaced apart from each other in the circumferential direction on the inner wall portion of the first member 21 and support the annular support portion 263 on the axis of the first member 21 . The second valve seat 241 is provided downstream of the annular support portion 263 and comes into contact with and separates from the second check valve 71 . The communication port 251 is provided in the rear body portion 25 between the annular support portion 263 and the second valve seat 241 and allows the flow path 97 and the first member 21 to communicate with each other. The second member 22 supports an annular support portion 273.

In the check valve unit 20, the second valve seat 241 is located closer to the annular support part 263 than the flow path 97, and the three construction parts 262 are located closer to the first valve seat 515 than the flow path 97. The second valve seat 241 and the three bridge sections 262 are supported by the inner wall of the upper lateral section 51 .

Since the three construction parts 262 are located upstream of the flow path 97, the distance between the annular support part 263 and the first valve seat 515 is shortened. As a result, the forward and backward stroke of the first check valve 70 is shortened, so that the axis shift of the first check valve 70 can be prevented. Therefore, the water heater 1 can maintain close contact with the first valve seat 515 when the first check valve 70 is in the closed state in the edge cutting valve unit 2.

Note that the present invention is not limited to the above embodiments, and various modifications are possible. Although the edge valve unit 2 has the flow path 95 and the flow path 96 provided vertically in parallel with each other, they may be provided in parallel, for example, in the left-right direction (horizontal direction).

The edge valve unit 2 includes four casings 3 to 6, which are fixed to each other with screws 301 to 305, but the number of casings and the method of fixing them can be changed freely. Furthermore, the directions in which the connection port 35, the hot water supply connection port 36, the connection port 58, the drain pipe 632, and the inflow pipe 633 open are not limited to those in the embodiment described above, and can be freely changed.

The flow path 97 of the edge valve unit 2 is provided along the vertical direction, but as long as it extends downward, it may be entirely or partially oblique or bent.

In the first member 21 of the check valve unit 20, there are three bridging parts 262 that support the annular support part 263, but the number of bridging parts 262 can be changed freely, and is preferably three or more.

In the valve support portion 26, the connecting portion 261 may be omitted. In that case, the outer ends of each of the plurality of construction parts 262 may be brought into contact with the inner wall part of the upper lateral part 51.

Regarding the method of attaching the check valve unit 20 to the upper lateral part 51, in the above embodiment, the first member 21 and the second member 22 are first assembled, and then inserted and arranged in the upper lateral part 51. However, the first member 21 may be inserted into the upper lateral part 51 first, and then the second member 22 may be inserted and arranged into the upper lateral part 51.

1 Water heater 2 Edge cutting valve unit 5 Third casing 11 Hot water supply circuit 12 Circulation heating circuit 20 Check valve unit 21 First member 22 Second member 25 Rear body portion 51 Upper lateral portion 57 Lid member 59 Opening portion 60 Opening portion 70 First check valve 71 Second check valve 73 Edge cutting valve 82 O-ring 95, 97 Channel 206 Hot water supply pipe 241 Second valve seat 242 Projection 261 Connecting portion 262 Erection portion 263 Annular support portion 274 Cylindrical portion 511 Small diameter part 512 Medium diameter part 513 Large diameter part 515 First valve seat 516 Fitting groove 519 Step part 572 Cylindrical part

Claims (3)

In a water heater in which a pipe connecting a hot water supply circuit and a circulation heating circuit is provided with an edge valve unit for preventing backflow of hot water from the circulation heating circuit side to the hot water supply circuit side,
The edge valve unit is
a main flow path extending linearly from an upstream opening to a downstream opening in the direction in which hot water flows;
It is branched from a branch part provided in the main flow path, is always biased in the valve-opening direction by a spring force, and is biased in the valve-closing direction against the spring force upon receiving back pressure from the hot water supply circuit. a branch road provided with a border valve;
a casing including the main flow path and the branch flow path, and a first valve seat provided at a peripheral edge of the upstream opening;
a cylindrical portion provided in the casing and having the main flow path formed inside;
a first check valve that is in contact with and separate from the first valve seat and prevents backflow of hot water from the circulation heating circuit side; and a second check valve that prevents backflow of hot water, and is inserted into the main flow path from the downstream opening so that the first check valve faces the first valve seat and can move toward and away from the first valve seat. and a check valve unit disposed within the cylindrical portion,
The check valve unit includes a first member and a second member disposed downstream of the first member,
The first member is formed in a cylindrical shape,
a first support part provided on the upstream side and supporting the first check valve;
a plurality of construction parts extending in the axial direction from positions spaced apart from each other in the circumferential direction on the inner wall part of the first member, and supporting the first support part on the axis of the first member;
a second valve seat that is provided downstream of the first support portion and that comes into contact with and separates from the second check valve;
a communication port provided in the body between the first support portion and the second valve seat, and communicating the branch path with the first member;
The second member includes a second support part that supports the second check valve,
In the check valve unit, the second valve seat is located closer to the second support portion than the branch path, and the plurality of construction parts are located closer to the first valve seat than the branch path. the second valve seat and the plurality of construction parts are supported by an inner wall part of the cylindrical part,
The inner wall portion of the cylindrical portion is fitted with a fitting portion provided on the check valve unit to restrict circumferential rotation of the check valve unit with respect to the casing. A department has been established,
The fitting portion is a protrusion that protrudes radially outward from the outer peripheral portion of the first member and extends parallel to the axial direction of the first member,
The water heater characterized in that the fitted portion is a notch or groove that extends parallel to the axial direction of the casing and that fits into the fitting portion . The first member includes an annular connecting part that connects with the plurality of construction parts,
The hot water supply according to claim 1, wherein the connecting portion is in close contact with an inner wall portion of the cylindrical portion on an upstream side of the branching path when the check valve unit is disposed within the cylindrical portion. vessel. The cylindrical part is
a cylindrical small diameter portion in which the first member is disposed;
a cylindrical large diameter part provided downstream of the small diameter part and having a larger diameter than the small diameter part;
comprising a cylindrical medium diameter part provided between the small diameter part and the large diameter part,
On the inside of the cylindrical portion, a step portion whose diameter decreases radially inward is provided between the large diameter portion and the medium diameter portion ,
The fitted portion is a notch or groove provided in the medium diameter portion, extending from the stepped portion in parallel to the axial direction of the casing, and fitting with the fitting portion. There it is,
The second member is disposed within the cylindrical portion and includes a cylindrical portion that is formed along the inner wall of the large diameter portion and whose downstream end extends downstream from the medium diameter portion. Prepare,
An O-ring is arranged on the downstream side of the cylindrical part,
A cylindrical positioning member is inserted and fixed to the peripheral edge of the downstream opening of the casing,
The O-ring is
Claim 1 , wherein the cylindrical part is sandwiched between the downstream end of the tubular part and the positioning member from the upstream and downstream sides along the inner wall of the downstream opening. Or the water heater described in 2 .

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