Drain switching unit

Abstract

This invention provides a drain switching unit that offers a high degree of flexibility in placement, further improving ease of installation. [Solution] The drain switching unit 1 comprises a case 60 having a rectangular parallelepiped shape, a flow path switching valve 61 for switching the flow path of the bath circulation circuit 3, a connection port 62 communicating with the flow path switching valve 61, and a mounting flange 63 for attaching the drain switching unit to the wall surface 40 of the bathroom 4. The connection port has a first connection port 62a provided on the top or bottom surface of the case to which the heat exchanger side piping 8a of the bath circulation supply pipe 8 is connected, a second connection port 62b provided on the top or bottom surface of the case to which the bathtub side piping 8b of the bath circulation supply pipe 8 is connected, and a third connection port 62c provided on the bottom surface of the case to which a drain drain pipe 10 for discharging drain into the bathroom is connected. The mounting flange (63L, 63R) is provided on one side of the case and on the other side of the case opposite to this side.

Description

Technical Field

[0001] The present invention relates to a drain switching unit for discharging the drain generated in the secondary heat exchanger of a water supply device to a bathroom by using a bathtub circulation circuit.

Background Art

[0002] Conventionally, there is a drain switching unit that flows the drain generated in the secondary heat exchanger of a water supply device into a bathtub circulation circuit and discharges it to a bathroom by switching the flow path of the bathtub circulation circuit (Patent Document 1). The conventional drain switching unit houses a three-way valve for switching the flow path in a case having a rectangular parallelepiped outer shape, and on the upper surface, bottom surface, and side surface of the case, there are provided connection ports for the heat exchange side pipe of the bathtub circulation forward pipe, connection ports for the bathtub side pipe of the bathtub circulation forward pipe, and connection ports for the drain drain pipe, respectively, and it is installed in the space between the wall surface of the bathroom and the bathtub.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, the drain switching unit is installed by attaching a mounting flange to one side of the narrow side of the case, and then attaching the mounting flange to the bathroom wall via a mounting plate. The installation pattern of the drain switching unit was such that, depending on the available space between the bathroom wall and the bathtub, the mounting plate corresponding to the mounting flange could be changed, allowing for two installation patterns: a first installation pattern in which the wider side of the case is positioned parallel to the bathroom wall, and a second installation pattern in which the wider side of the case is positioned perpendicular to the bathroom wall. However, with the conventional configuration of the drain switching unit, the mounting position of the drain switching unit to the bathroom wall was limited to the side with the mounting flange. In addition, the pipe connection ports are provided on the top, bottom, and side of the case, and pipes are connected from three directions. Therefore, even when installed in the first or second installation pattern, one pipe may cross over other pipes, making it difficult to install the drain switching unit in narrow spaces.

[0005] The present invention has been made in view of the above circumstances, and aims to provide a drain switching unit that allows for a high degree of freedom in the placement of the drain switching unit and further improves ease of installation. [Means for solving the problem]

[0006] The drain switching unit according to embodiment 1 of the present invention is A drain switching unit installed in the bathroom and connected to the bath circulation circuit of the hot water heater, which discharges the drain generated by the secondary heat exchanger of the hot water heater into the bathroom through the bath circulation circuit, The device comprises a case having a rectangular parallelepiped shape, a flow path switching valve housed within the case for switching the flow path of the bath circulation circuit, a connection port provided on the structural wall of the case for communicating with the flow path switching valve, and a mounting flange provided on the structural wall of the case for attaching the drain switching unit to the bathroom wall. The aforementioned connection port portion is A first connection port is provided on the top or bottom surface of the case, to which the heat exchanger side piping of the bath circulation supply pipe in the bath circulation circuit is connected, A second connection port is provided on the top or bottom surface of the case, to which the bathtub-side piping of the bath circulation supply pipe in the bath circulation circuit is connected, It has a third connection port located on the bottom of the case, to which a drain pipe for discharging drain water into the bathroom is connected, The aforementioned mounting flange is provided on one side of the case and on the other side of the case opposite to this side.

[0007] According to the above configuration, since mounting flanges are provided at two locations on one and the other side of the case, the drain switching unit can be mounted to the bathroom wall using one of the mounting flanges by reversing the orientation of the unit. This increases the number of options for the orientation of the drain switching unit, and improves the degree of freedom in placement. Therefore, by reversing the drain switching unit, for example, the bathtub-side piping and the drain drain pipe (or the heat exchanger-side piping and the drain drain pipe if the first connection port is provided on the bottom of the case) connected to the second and third connection ports on the bottom of the case can be installed so that they do not cross, improving the ease of installation of the drain switching unit in narrow spaces.

[0008] Furthermore, if the connection port is located on the side of the case, as in conventional designs, inverting the drain switching unit would bring the side of the case with the connection port closer to the bathroom wall, making it difficult to connect the piping. However, in the configuration of the present invention, the connection port is located on the top and bottom surfaces of the case, and not on the sides, so even if the drain switching unit is inverted, the piping can be easily connected.

[0009] The drain switching unit according to embodiment 2 of the present invention, in embodiment 1, The mounting flange can be configured to be provided at an intermediate position in the lateral direction on one side and the other side of the case.

[0010] With this configuration, the distance between the mounting flange and the bathroom wall does not change even when the drain switching unit is reversed, making installation easier even when reversing the drain switching unit.

[0011] The drain switching unit according to embodiment 3 of the present invention, in embodiment 1 or 2, The mounting flange can be configured by having projections provided on the upper and lower sides of one and the other side of the case, with holes for screw fastening provided in the projections.

[0012] With this configuration, even when the drain switching unit is installed upside down on the bathroom wall, it can be easily installed by screw fixing. In addition, since the mounting flange consists of upper and lower protrusions, the drain switching unit can be mounted on the bathroom wall in a stable position without rotating in the vertical direction.

[0013] The drain switching unit according to embodiment 4 of the present invention, in embodiment 3, The mounting flange on one or the other side of the case is connected by screw fastening, and has a mounting plate for attaching the drain switching unit to the bathroom wall. The mounting plate may have a mounting surface portion for mounting to the bathroom wall, a parallel surface portion parallel to the mounting surface portion, and a vertical surface portion perpendicular to the mounting surface portion, with fixing holes for screw fastening to the mounting flange provided in the parallel surface portion and the vertical surface portion.

[0014] With this configuration, by screwing the mounting flange to the parallel or vertical surface of the mounting plate, the drain switching unit can be mounted in a first installation pattern where the wider side of the case is parallel to the bathroom wall, and in a second installation pattern where the wider side of the case is perpendicular to the wall. Furthermore, the drain switching unit can also be mounted on the bathroom wall in an installation pattern where one side of the narrower side of the case is reversed. In this way, since one type of mounting plate can be used in common for each installation pattern, the ease of installation of the drain switching unit is further improved. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing the configuration of a hot water supply system. [Figure 2] It is an external view showing a drain switching unit according to an embodiment. [Figure 3] It is a cross-sectional view showing a drain switching unit according to an embodiment. [Figure 4] It is a perspective view showing a mounting plate of a drain switching unit according to an embodiment. [Figure 5] It is an explanatory view showing an installation pattern of a drain switching unit according to an embodiment, where FIG. (a) shows the first installation pattern and FIG. (b) shows the third installation pattern with the drain switching unit inverted. [Figure 6] It is an explanatory view showing an installation pattern of a drain switching unit according to an embodiment, where FIG. (a) shows the second installation pattern and FIG. (b) shows the fourth installation pattern with the drain switching unit inverted.

MODE FOR CARRYING OUT THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The water supply device 2 shown in FIG. 1 is a latent heat recovery type gas water supply device provided with a secondary heat exchanger 22 and a bath circulation circuit 3. In such a water supply device 2, in the secondary heat exchanger 22, combustion exhaust gas is cooled and condensed by heat exchange for latent heat recovery, thereby generating drain (condensed water). The drain switching unit 1 of the present embodiment is a device that discharges the drain generated in the secondary heat exchanger 22 of the water supply device 2 to the bathroom 4 through the bath circulation circuit 3. The water supply device 2 is installed outdoors, and the bath circulation circuit 3 of the water supply device 2 penetrates the outer wall of the house and the wall of the bathroom 4 and is drawn into the bathroom 4 and connected to the circulation adapter 42 of the bathtub 41.

[0017] The drain switching unit 1 is installed in the bathroom 4 by being connected to the bath circulation circuit 3 of the water supply apparatus 2. Specifically, the drain switching unit 1 is installed in the empty space S between the wall surface 40 of the bathroom 4 and the bathtub 41 (see FIGS. 5 and 6), the heat exchange side pipe 8a of the bath circulation forward pipe 8 in the bath circulation circuit 3 and the bathtub side pipe 8b are connected, and a drain drain pipe 10 for discharging the drain to the bathroom 4 is connected. Note that the heat exchange side pipe 8a of the bath circulation forward pipe 8 refers to the pipe portion connecting the drain switching unit 1 and the bath heat exchanger 16 in the bath circulation forward pipe 8, and the bathtub side pipe 8b of the bath circulation forward pipe 8 refers to the pipe portion connecting the drain switching unit 1 and the circulation adapter 42 of the bathtub 41 in the bath circulation forward pipe 8. The drain drain pipe 10 is extended and disposed from the drain switching unit 1 to the drain port 12 of the waterproof pan 11 of the bathtub 41. And the drain switching unit 1 switches the flow path so that the heat exchange side pipe 8a of the bath circulation forward pipe 8 is in a state of being communicated with the drain drain pipe 10 during the drain discharge operation.

[0018] The water supply apparatus 2 includes a gas burner 13 that generates combustion exhaust gas, a fan 14 that supplies combustion air to the gas burner 13, a water supply heat exchanger 15 and a bath heat exchanger 16 that absorb heat from the combustion exhaust gas to heat hot water. A gas supply pipe 17 for supplying fuel gas is connected to the gas burner 13. The gas supply pipe 17 is provided with an original gas solenoid valve 18, a gas proportional valve 19, and a switching gas solenoid valve 20 in order from the upstream side. The water supply heat exchanger 15 and the bath heat exchanger 16 include a primary heat exchanger 21 that recovers sensible heat from the combustion exhaust gas and a secondary heat exchanger 22 that recovers latent heat from the combustion exhaust gas.

[0019] Furthermore, the hot water supply system 2 is equipped with a neutralizer 23 for neutralizing the drain generated in the secondary heat exchanger 22. The neutralizer 23 has a neutralization treatment tank 24 for neutralizing the drain and a drain tank section 25 for temporarily storing the drain after neutralization. The drain tank section 25 is equipped with a water level detector 26 for detecting the water level of the stored drain. The secondary heat exchanger 22 is equipped with a drain collection pan 221 for collecting the drain, and a drain introduction pipe 27 drawn from the drain collection pan 221 is connected to the neutralizer 23. The drain tank section 25 is connected to a drain outlet pipe 28 for discharging the stored drain, and the drain outlet pipe 28 is equipped with a check valve 29 to prevent backflow of drain to the drain tank section 25.

[0020] The hot water heat exchanger 15 is connected to an inlet pipe 30 and an outlet pipe 31. The inlet pipe 30 is equipped with a water flow sensor 32, a water supply temperature sensor 33, and a water flow servo 34, in that order from the upstream side. The outlet pipe 31 is equipped with a heat exchanger temperature sensor 35 on the upstream side and an outlet temperature sensor 36 on the downstream side. The bath heat exchanger 16 is connected to a bath circulation return pipe 9 and a bath circulation supply pipe 8, which constitute the bath circulation circuit 3. The bathtub side ends of the bath circulation return pipe 9 and the bath circulation supply pipe 8 are connected to a circulation adapter 42 of the bathtub 41. The bath circulation supply pipe 8 is equipped with a drain switching unit 1 and a bath supply temperature sensor 37, in that order from the bathtub 41 side. The bath circulation return pipe 9 is equipped with a bath return temperature sensor 38, a switching valve 5, a pump P, and a bath water flow switch 51, in that order from the bathtub 41 side. The bath circulation return pipe 9 is connected to a hot water filling pipe 52 drawn from the outlet pipe 31 between the switching valve 5 and the pump P. The hot water filling pipe 52 is equipped with a hot water filling solenoid valve 53, check valves 54a and 54b, and a hot water volume sensor 55, in that order from the outlet pipe 31 side. A drain outlet pipe 28, drawn from the drain tank section 25 of the neutralizer 23, is connected to a switching valve 5 installed in the bath circulation return pipe 9. The switching valve 5 connects the pump P and the drain outlet pipe 28 during drain discharge operation, and switches the flow path to connect the pump P and the bathtub side piping 9b of the bath circulation return pipe 9 during hot water filling operation, reheating operation, and cleaning operation. The bathtub side piping 9b of the bath circulation return pipe 9 refers to the piping portion in the bath circulation return pipe 9 that connects the pump P and the circulation adapter 42 of the bathtub 41, and the heat exchanger side piping 9a of the bath circulation return pipe 9 refers to the piping portion in the bath circulation return pipe 9 that connects the pump P and the bath heat exchanger 16.

[0021] The hot water supply system 2 includes a control unit 6 that controls the operation of each part of the hot water supply system 2. The control unit 6 also controls the drain switching unit 1. The hot water supply system 2 performs various operations such as hot water supply operation, bath filling operation, reheating operation, drain discharge operation, and cleaning operation.

[0022] In hot water supply operation, water supplied to the inlet pipe 30 is heated in the hot water heat exchanger 15 to produce hot water, and this hot water is supplied to the hot water destination such as a faucet through the outlet pipe 31. Note that during hot water supply operation, the flow path position in the switching valve 5 and the flow path position in the drain switching unit 1 can be in any position. In bath filling operation, the switching valve 5 is set to connect the pump P and the bathtub side piping 9b of the bath circulation return pipe 9, and the drain switching unit 1 is set to connect the heat exchanger side piping 8a of the bath circulation supply pipe 8 and the bathtub side piping 8b. In this state, the bath filling solenoid valve 53 is opened, and the hot water produced in the hot water heat exchanger 15 is supplied from the outlet pipe 31 to the bath circulation return pipe 9 of the bath circulation circuit 3 via the bath filling pipe 52, and this hot water is supplied to the bathtub 41 from the circulation adapter 42 through the bath circulation circuit 3. In the reheating operation, the switching valve 5 is set to connect the pump P and the bathtub-side piping 9b of the bath circulation return pipe 9, and the drain switching unit 1 is set to connect the heat exchanger-side piping 8a of the bath circulation supply pipe 8 and the bathtub-side piping 8b. In this state, the pump P is driven to draw the bathtub water in the bathtub 41 from the circulation adapter 42, heat it in the bath heat exchanger 16 via the bath circulation return pipe 9 of the bath circulation circuit 3, and return this heated bathtub water from the circulation adapter 42 to the bathtub 41 via the bath circulation supply pipe 8 of the bath circulation circuit 3.

[0023] During the drain discharge operation, the switching valve 5 is set to connect the pump P and the drain outlet pipe 28, and the drain switching unit 1 is set to connect the heat exchanger side piping 8a of the bath circulation supply pipe 8 and the drain drain pipe 10. In this state, the pump P is driven to cause the drain from the drain tank section 25 to flow from the drain outlet pipe 28 into the bath circulation return pipe 9, and from the bath circulation return pipe 9 through the bath circulation supply pipe 8 to the drain switching unit 1. The drain supplied to the drain switching unit 1 is discharged through the drain drain pipe 10 to the drain port 12 of the waterproof pan 11. After the drain discharge operation is completed, a cleaning operation is performed to clean the bath circulation circuit 3 through which the drain has flowed. During the cleaning operation, the switching valve 5 is set to connect the pump P and the bathtub side piping 9b of the bath circulation return pipe 9, and the drain switching unit 1 is set to connect the heat exchanger side piping 8a of the bath circulation supply pipe 8 and the drain drain pipe 10. In this state, the hot water filling solenoid valve 53 is opened to supply clean hot water or water from the hot water filling pipe 52 to the bath circulation return pipe 9 of the bath circulation circuit 3, and the cleaned hot water or water supplied to the drain switching unit 1 is discharged through the drain drain pipe 10 to the drain port 12 of the waterproof pan 11. Alternatively, during the cleaning operation, the drain switching unit 1 may be configured to connect the heat exchanger side pipe 8a and the bathtub side pipe 8b of the bath circulation supply pipe 8, and the cleaned hot water or water supplied to the drain switching unit 1 may be discharged through the bathtub side pipe 8b to the bathtub 41 and to the drain port 12 through the drain plug of the bathtub 41.

[0024] Next, we will describe the drain switching unit 1. As shown in Figures 2 and 3, the drain switching unit 1 comprises a case 60 having a rectangular parallelepiped shape, a flow path switching valve 61 housed within the case 60 for switching the flow path of the bath circulation circuit 3, three connection ports 62a, 62b, 62c (62) provided on the structural wall of the case 60 for connecting to the flow path switching valve 61, and mounting flanges 63L, 63R provided on the structural wall of the case 60 for attaching the drain switching unit 1 to the wall surface 40 of the bathroom 4.

[0025] The case 60 has walls formed by two opposing wide sides (front side and rear side) and four narrow sides (top, bottom, right side, and left side) provided on the periphery of the wide sides. The case 60 consists of a roughly rectangular parallelepiped case body 64 having an opening on one of the wide sides (the front side) and a rectangular lid plate 65 that covers the opening of the case body 64. The case body 64 is made of resin, and the lid plate 65 is made of metal such as stainless steel. The lid plate 65 is attached to the opening of the case body 64 by screw fastening with a sealing gasket (not shown) interposed between them. In this specification, when the case 60 is placed horizontally and standing upright, the upper and lower sides on the narrow side are referred to as the top and bottom sides, the left and right sides on the narrow side are referred to as one side and the other side, and the front and rear sides on the wide side are referred to as one side and the other side.

[0026] As shown in Figure 3, the flow path switching valve 61 has a housing 67 provided with three flow path ports 66a, 66b, and 66c (66), and a valve body 68 housed within the housing 67. The flow path ports 66 include a first flow path port 66a located at the top of the housing 67, and a second flow path port 66b and a third flow path port 66c located at the bottom of the housing 67. The valve body 68 is attached to a valve shaft 69, which is connected to a motor (drive source) M housed in a case 60. The motor M is electrically connected to a control device C housed in the case 60. The control device C is electrically connected to the control unit 6 of the hot water supply device 2 via electrical wiring. Driven by the motor M, the valve body 68 moves forward and backward via the valve shaft 69. This flow path switching valve 61 can switch between a state in which the upper first flow path port 66a and the lower second flow path port 66b are in communication, and a state in which the upper first flow path port 66a and the lower third flow path port 66c are in communication, by driving the motor M in response to a command from the control device C to move the valve body 68.

[0027] The connection port 62 is made up of a pipe protruding from the structural wall of the case 60 and has a first connection port 62a provided on the upper surface of the case 60, and a second connection port 62b and a third connection port 62c provided on the bottom surface of the case 60. The first connection port 62a communicates with the first flow port 66a of the flow path switching valve 61 inside the case 60 and is connected to the heat exchanger side piping 8a of the bath circulation supply pipe 8 in the bath circulation circuit 3 outside the case 60. The second connection port 62b communicates with the second flow port 66b of the flow path switching valve 61 inside the case 60 and is connected to the bathtub side piping 8b of the bath circulation supply pipe 8 in the bath circulation circuit 3 outside the case 60. The third connection port 62c communicates with the third flow port 66c of the flow path switching valve 61 inside the case 60 and is connected to the drain pipe 10 outside the case 60. Therefore, the drain switching unit 1 can switch the flow path between a state in which the heat exchanger side piping 8a of the bath circulation supply pipe 8 connected to the first connection port 62a is in communication with the bathtub side piping 8b of the bath circulation supply pipe 8 connected to the second connection port 62b, and a state in which the heat exchanger side piping 8a of the bath circulation supply pipe 8 connected to the first connection port 62a is in communication with the drain drain pipe 10 connected to the third connection port 62c, using the flow path switching valve 61. In this embodiment, the flow path switching valve 61 is configured to switch the flow paths 66a, 66b, and 66c provided on the upper and lower parts of the housing 67 by moving the valve body 68 back and forth, making it easier to provide the connection ports 62a, 62b, and 62c of the drain switching unit 1 on the upper and lower parts of the case 60.

[0028] The mounting flanges 63L and 63R are provided so as to protrude from one narrow side of the case 60 and the other narrow side of the case 60 opposite to this side, and are provided on both the left and right sides of the case 60. The mounting flanges 63L and 63R are composed of projections T that protrude outward from the outer surface of the case body 64, and the mounting flanges 63L and 63R on the left and right sides are provided vertically on one side and the other side of the case 60, and are located at the midpoint in the lateral width direction of the narrow side (see Figure 2). Each projection T that forms the mounting flanges 63L and 63R is provided with a hole h for screw fixing to a mounting plate 7 used for attaching the drain switching unit 1 to the wall surface 40 of the bathroom 4.

[0029] As shown in Figure 4, the mounting plate 7 is attached to the wall surface 40 of the bathroom 4 by screw fixing, and one of the mounting flanges 63L and 63R provided on one side and the other side of the case 60 is connected by screw fixing. In this way, the drain switching unit 1 is attached to the wall surface 40 of the bathroom 4 via the mounting plate 7. The mounting plate 7 is made of sheet metal and is formed by bending it into a roughly Z shape. The mounting plate 7 has a mounting surface portion 71 that is attached to the wall surface 40 of the bathroom 4, a vertical surface portion 72 perpendicular to the mounting surface portion 71, and a parallel surface portion 73 parallel to the mounting surface portion 71. The mounting surface portion 71 has fixing holes k1 at the top and bottom for screw fixing to the wall surface 40 of the bathroom 4. The vertical surface portion 72 and the parallel surface portion 73 have fixing holes k2 and k3 at the top and bottom for screw fixing to the holes h of the mounting flanges 63L and 63R.

[0030] Next, we will explain the installation patterns for the drain switching unit 1. To install the drain switching unit 1 onto the wall surface 40 of the bathroom 4, the mounting plate 7 is attached to the wall surface 40 of the bathroom 4. To attach the mounting plate 7 to the wall surface 40 of the bathroom 4, the mounting surface portion 71 is brought into contact with the wall surface 40 of the bathroom 4, and a screw N is inserted through the fixing hole k1 of the mounting surface portion 71 and secured with a screw (see Figure 4).

[0031] The drain switching unit 1 can be installed with the wider side of the case 60 parallel to the wall surface 40 of the bathroom 4 via the mounting plate 7, or with the wider side of the case 60 positioned perpendicular to it. Specifically, referring to Figures 5(a)(b) and 6(a)(b), the drain switching unit 1 can be installed in two ways: a first installation pattern (see Figure 5(a)) in which the mounting flange 63L on one side is brought into contact with the parallel surface portion 73 of the mounting plate 7 attached to the wall surface 40 of the bathroom 4, a screw N is inserted through the hole h of the mounting flange 63L and the fixing hole k3 of the mounting plate 7 and fixed with a screw to connect them, and the case 60 is installed with its wider side parallel to the wall surface 40 of the bathroom 4; and a second installation pattern (see Figure 6(a)) in which the mounting flange 63L on one side is brought into contact with the vertical surface portion 72 of the mounting plate 7, a screw N is inserted through the hole h of the mounting flange 63L and the fixing hole k2 of the mounting plate 7 and fixed with a screw to connect them, and the case 60 is installed with its wider side perpendicular to the wall surface 40 of the bathroom 4.

[0032] Furthermore, the drain switching unit 1 can be installed in two ways: a third installation pattern (see Figure 5(b)) in which one side is reversed and the mounting plate 7 attached to the wall surface 40 of the bathroom 4 is fitted with the mounting flange 63R on the other side against the parallel surface portion 73 of the mounting plate 7, and a screw N is inserted through the hole h of the mounting flange 63R and the fixing hole k3 of the mounting plate 7 to secure it with a screw, with the wider side of the case 60 positioned parallel to the wall surface 40 of the bathroom 4; and a fourth installation pattern (see Figure 6(b)) in which the mounting flange 63R on the other side is fitted with the vertical surface portion 72 of the mounting plate 7, and a screw N is inserted through the hole h of the mounting flange 63R and the fixing hole k2 of the mounting plate 7 to secure it with a screw, with the wider side of the case 60 positioned perpendicular to the wall surface 40 of the bathroom 4.

[0033] As described above, with the drain switching unit 1 of this embodiment, since the mounting flanges 63L and 63R are provided at two locations on opposite sides of the case 60, the drain switching unit 1 can be reversed and attached to the bathroom wall 40 by one of the mounting flanges (63L or 63R). In other words, in addition to the first and second installation patterns in which the mounting flange 63L on one side of the drain switching unit 1 is connected to the mounting plate 7, it is also possible to install the drain switching unit 1 in a third and fourth installation pattern in which the mounting flange 63R on the other side of the drain switching unit 1 is reversed and attached to the mounting plate 7. Therefore, the selection of the orientation of the drain switching unit 1 is increased, and the degree of freedom in placement is enhanced. Therefore, by reversing the drain switching unit 1, for example, it can be installed so that the bathtub-side piping 8b connected to the second connection port 62b and the drain pipe 10 connected to the third connection port 62c do not cross at the bottom surface of the case 60, thereby improving the ease of installation of the drain switching unit 1 in a narrow space S.

[0034] Furthermore, in conventional drain switching units, if the connection port is located on the side of the case, inverting the drain switching unit brings the side of the case with the connection port close to the wall 40 of the bathroom 4, making it difficult to connect the piping. However, in the drain switching unit 1 of this embodiment, the first, second, and third connection ports 62a, 62b, and 62c are located on the top and bottom surfaces of the case 60, and not on the side, so even if the drain switching unit 1 is inverted, the piping can be easily connected.

[0035] Furthermore, according to the drain switching unit 1 of this embodiment, the mounting flanges 63L and 63R (projections T) are provided at intermediate positions in the lateral direction on one side and the other side of the case 60. Therefore, even if the drain switching unit 1 is inverted, the distance between the mounting flanges 63L and 63R and the wall surface 40 of the bathroom 4 does not change. Thus, even when the drain switching unit 1 is inverted, the same mounting plate 7 can be used to easily perform the installation.

[0036] Furthermore, according to the drain switching unit 1 of this embodiment, the mounting flanges 63L and 63R are composed of projections T provided on the upper and lower sides of one and the other sides of the case 60, and the projections T are provided with holes h for screw fixing, so even when the drain switching unit 1 is installed upside down on the wall surface 40 of the bathroom 4, it can be easily installed by screw fixing. In addition, by composing the mounting flanges 63L and 63R with upper and lower projections T, the drain switching unit 1 can be attached to the wall surface 40 of the bathroom 4 in a stable position without rotating in the vertical direction.

[0037] Furthermore, the mounting plate 7 used to attach the drain switching unit 1 to the wall surface 40 of the bathroom 4 has a mounting surface portion 71 that attaches to the wall surface 40 of the bathroom 4, a vertical surface portion 72 perpendicular to the mounting surface portion 71, and a parallel surface portion 73 parallel to the mounting surface portion 71. The vertical surface portion 72 and the parallel surface portion 73 are provided with fixing holes k2 and k3 for screw fixing to the holes h of the mounting flanges 63L and 63R. Therefore, this mounting plate 7 allows the drain switching unit 1 to be attached to the wall surface 40 of the bathroom 4 in a first installation pattern in which the wider side of the case 60 is positioned parallel to the wall surface 40 of the bathroom 4, and in a second installation pattern in which the wider side of the case 60 is positioned perpendicular to the wall surface 40. In addition, the drain switching unit 1 can also be attached to the wall surface 40 of the bathroom 4 in third and fourth installation patterns in which one side of the narrow side of the case 60 is reversed. In this way, since one type of mounting plate 7 can be used in common for each installation pattern, the ease of installation of the drain switching unit 1 is further improved.

[0038] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims. For example, in the drain switching unit 1, a second connection port 62b for connecting the bathtub-side piping 8b of the bath circulation supply pipe 8 may be provided on the upper surface of the case 60, and a first connection port 62a for connecting the heat exchanger-side piping 8a of the bath circulation supply pipe 8 may be provided on the bottom surface of the case 60. A third connection port 62c for connecting the drain pipe 10 is provided on the bottom surface of the case 60. In this case, the flow path switching valve inside the case 60 is configured such that, during drain discharge operation, the first connection port 62a, which connects to the heat exchanger side piping 8a at the bottom of the case 60, and the third connection port 62c, which connects to the drain drain pipe 10 at the bottom of the case 60, are in communication, and during hot water filling operation and reheating operation, the valve is configured such that the first connection port 62a, which connects to the heat exchanger side piping 8a at the bottom of the case 60, and the second connection port 62b, which connects to the bathtub side piping 8b at the top of the case 60, are in communication. Furthermore, the flow path switching valve 61 provided in the drain switching unit 1 may be a three-way valve having an L-shaped flow path inside. [Explanation of Symbols]

[0039] 1. Drain switching unit 2. Hot water supply system 3. Bath circulation circuit 4 Bathroom 5. Switching valve 6 Control Unit 7 Mounting plate 8. Bath circulation supply pipe 8a Heat exchanger side piping 8b Piping on the bathtub side 9 Bath circulation return pipe 10 Drain pipe 11 Waterproof tray 12 Drain 15. Hot water heat exchanger 16. Bath heat exchanger 21 Primary heat exchanger 22 Secondary heat exchanger 23 Neutralizer 40 Wall surface 41 Bathtub 60 cases 61 Flow path switching valve 62a First connection port 62b Second connection port 62c Third connection port 63L, 63R Mounting flange 64 Case body 65 Lid plate 66a 1st channel mouth 66b 2nd channel mouth 66c 3rd channel mouth 67 Housing 68 Valve body 69 Valve stem 71 Mounting surface 72 Vertical surface section 73 Parallel plane part C Control equipment h hole k1, k2, k3 fixing holes M Motor N Screw P Pump S (empty space) T protrusion

Claims

1. A drain switching unit installed in the bathroom and connected to the bath circulation circuit of the hot water heater, which discharges the drain generated by the secondary heat exchanger of the hot water heater into the bathroom through the bath circulation circuit, The device comprises a case having a rectangular parallelepiped shape, a flow path switching valve housed within the case for switching the flow path of the bath circulation circuit, a connection port provided on the structural wall of the case for communicating with the flow path switching valve, and a mounting flange provided on the structural wall of the case for attaching the drain switching unit to the bathroom wall. The aforementioned connection port portion is A first connection port is provided on the top or bottom surface of the case, to which the heat exchanger side piping of the bath circulation supply pipe in the bath circulation circuit is connected, A second connection port is provided on the top or bottom surface of the case, to which the bathtub-side piping of the bath circulation supply pipe in the bath circulation circuit is connected, It has a third connection port located on the bottom of the case, to which a drain pipe for discharging drain water into the bathroom is connected, The aforementioned mounting flange is provided on one side of the case and on the other side of the case opposite to this side, in a drain switching unit.

2. In the drain switching unit according to claim 1, The aforementioned mounting flange is provided at an intermediate position in the lateral direction on one side and the other side of the case, in the drain switching unit.

3. In the drain switching unit according to claim 1 or 2, The drain switching unit comprises a mounting flange composed of projections provided vertically on one side and the other side of the case, with holes for screw fixing provided in the projections.

4. In the drain switching unit according to claim 3, The mounting flange on one or the other side of the case is connected by screw fastening, and has a mounting plate for attaching the drain switching unit to the bathroom wall. The aforementioned mounting plate has a mounting surface portion for mounting to the bathroom wall, a parallel surface portion parallel to the mounting surface portion, and a vertical surface portion perpendicular to the mounting surface portion, and fixing holes for screw fastening to the holes of the mounting flange are provided in the parallel surface portion and the vertical surface portion, wherein the drain switching unit.

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