Water heater and joint components

Abstract

The present invention provides a water heater and joint components that minimize misalignment of piping in the front-to-back and up-down / left-to-right directions, thereby suppressing water leakage from pipe connections. [Solution] The present invention comprises a hot water storage tank 2, an outer box 3 housing the hot water storage tank 2, an insulating material 6 provided between the outer box 3 and the hot water storage tank 2 connected to the hot water storage tank 2, a partition plate 3a that separates the insulating material 6 from the space in front of it and has through holes 3a1 and 3a2, and a tubular joint member 17 with one end connected to internal pipes 11 and 14 and the other end connected to external pipes 11g and 14g, wherein the joint member 17 has three or more positioning protrusions 17cs, 17ci that abut against the inner circumferential surfaces 3a11 and 3a21 of the through holes 3a1 and 3a2 to position the joint member 17 in the left-right and up-down directions.

Description

Technical Field

[0001] The present invention relates to a water heater and a joint member.

Background Art

[0002] A water heater is configured to include a hot water storage tank unit in which a hot water storage tank is accommodated, and a connection pipe space provided with a connection pipe on the front side of the hot water storage tank unit. The hot water storage tank unit and the connection pipe space in the water heater are covered with an outer box of the outer shell. Inside the outer box, the hot water storage tank unit and the connection pipe space are defined by a partition plate.

[0003] The inside of the outer box forming the hot water storage tank unit and the inside of the partition plate are filled with urethane foam around the water heater. The hot water storage tank is insulated from the external space by urethane foam. A water supply pipe and a hot water outlet pipe are connected to the hot water storage tank. The water supply pipe is a pipe for supplying water from a supply source such as a water supply to the hot water storage tank. The hot water outlet pipe is a pipe for supplying hot water from the hot water storage tank to the outside. The partition plate is provided with a water supply through hole through which the water supply pipe is inserted and a hot water outlet through hole through which the hot water outlet pipe is inserted.

[0004] Here, the inside of the hot water storage tank unit is filled with a foam heat insulating material. Therefore, when the foam heat insulating material is filled, the water supply pipe and the hot water outlet pipe receive an external force, and positional displacement occurs from the water supply through hole and the hot water outlet through hole, respectively. When positional displacement occurs, there is a possibility of water leakage from the pipe connection part. Therefore, Patent Document 1 describes that a retaining jig (70), which is a member for positioning each of the water supply pipe and the hot water outlet pipe so as to be aligned in the axial direction of the water supply through hole and the hot water outlet through hole, is installed.

[0005] The retaining jig (70) of Patent Document 1 (see FIG. 4(c) of Patent Document 1) can be effectively positioned with respect to the front-rear direction of the water heater.

Prior Art Documents

[0006] [Patent Document 1] Patent No. 06296551 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, while the positioning of the water supply and hot water outlet pipes by the retaining jig (70) is effective in the front-to-back direction, its effect is limited in the up-and-down and left-to-right directions. As a result, during the foaming process of the foam insulation material inside the outer box, compressive force is applied to the water supply and hot water outlet pipes, etc., which may cause misalignment between the water supply and hot water outlet pipes and the water supply and hot water outlet penetration holes. In this case, there is a risk of water leakage. The present invention aims to provide a water heater and joint member that can prevent misalignment of piping in the front-to-back and up-down-left-right directions, and suppress water leakage from pipe connections. [Means for solving the problem]

[0008] To solve the aforementioned problems, the hot water storage tank unit of the present invention comprises an outer box for housing the hot water storage tank, internal piping connected to the hot water storage tank, external piping connected to the internal piping, an insulating material provided between the outer box and the hot water storage tank, a partition plate having a through hole that separates the insulating material from the space in front of it, and a tubular joint member having one end connected to the internal piping and the other end connected to the external piping, wherein the joint member has three or more positioning protrusions that abut against the inner circumferential surface of the through hole to position the joint member in the left-right and up-down directions. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a water heater and joint member that can prevent misalignment of piping in the front-to-back and up-down-left-right directions, and suppress water leakage from the piping connection. [Brief explanation of the drawing]

[0010] [Figure 1A] This is a perspective view showing the overall configuration of a water heater equipped with a hot water storage tank unit according to the first embodiment. [Figure 1B] This is a front view showing the positional relationship of each elbow joint of a water heater equipped with a hot water storage tank unit according to the first embodiment, as they are fixed to the partition plate. [Figure 2] This is an enlarged perspective view of section I in Figure 1A. [Figure 3] This is an enlarged perspective view of section I in Figure 1A, showing the elbow fitting of the connecting joint removed. [Figure 4] This is a perspective view showing an elbow fitting and a hot water pipe connected to the elbow fitting. [Figure 5A] This is a view from the direction of arrow II in Figure 4. [Figure 5B] This is a view from the direction of arrow III in Figure 5A. [Figure 5C] This is a view from the direction of arrow IV in Figure 5A. [Figure 5D] Figure 5A is a cross-sectional view of the VV section. [Figure 6] This is a cross-sectional perspective view of the elbow joint fixed to the partition plate, before the external hot water supply pipe is connected. [Figure 7] This is an enlarged side cross-sectional view showing the elbow joint fixed to the partition plate. [Figure 8A] This is a perspective cross-sectional view showing the state in which the elbow joint to which the hot water supply pipe connected to the hot water storage tank is connected to the external hot water supply pipe. [Figure 8B] This is an enlarged side cross-sectional view showing an external hot water pipe connected to a fixed elbow joint. [Figure 9] This is a perspective view of the elbow joint of the second embodiment, viewed from the front upper right. [Figure 10] This is a longitudinal cross-sectional view taken in the direction of arrow VI in Figure 2, showing the state in which the hot water supply pipe is fitted and fixed into the tank piping connection pipe of the elbow joint. [Figure 11] This is a top view of the fixing pin. [Figure 12]It is an enlarged perspective sectional view seen obliquely from above of the VII-VII cross section of FIG. 10. [Figure 13] It is a perspective view seen from the upper left rear showing the process of connecting the hot water supply pipe to the tank pipe connection pipe of the elbow joint. [Figure 14] It is a perspective view showing the state after inserting the fixing pin from the mounting hole of the pin insertion pipe part after connecting the tank pipe connection pipe of the elbow joint and the hot water supply pipe. [Figure 15] It is a perspective view of the W elbow joint according to the third embodiment seen from the front right. [Figure 16] It is a longitudinal sectional view showing the state where the pipe is inserted and fixed to the pipe connection pipe of the joint of the fourth embodiment. [Figure 17] It is a top view of the fixing pin of the fourth embodiment.

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with appropriate reference to the drawings. (First Embodiment) FIG. 1A is a perspective view showing the overall configuration of a water heater K provided with a hot water storage tank unit 1 according to the first embodiment. In FIG. 1A, the outer box 3 is shown in a perspective view. Hereinafter, the vertical direction and the horizontal direction are shown in FIG. 1A, and the front-rear, left-right direction is shown in FIG. 2. The water heater K of the first embodiment includes a hot water storage tank unit 1 and a heat pump unit (not shown). The heat pump unit is a heat source for heating water to make hot water. The hot water storage tank unit 1 is a tank for storing and supplying hot water.

[0012] The hot water storage tank unit 1 includes a hot water storage tank 2, an outer box 3, inner legs 4, and a foamed heat insulating material 6. The inner legs 4 are support members that support the hot water storage tank 2 from below inside the outer box 3. The foamed heat insulating material 6 is filled in the outer space of the hot water storage tank 2 in the outer box 3 to insulate the hot water storage tank 2 from the external space.

[0013] <Hot water storage tank 2> The hot water storage tank 2 is made of, for example, rust-resistant stainless steel with a titanium layer formed on its surface. The hot water storage tank 2 is constructed by welding (for example, arc welding, thermite welding, etc.) at each joint of a central cylindrical shell plate 2a, a roughly bowl-shaped upper end plate 2b that covers the upper opening of the shell plate 2a, and a roughly bowl-shaped lower end plate 2c that covers the lower opening of the shell plate 2a. In addition, multiple temperature sensors (for example, thermistors that detect temperature changes as changes in physical properties (resistance values)) are provided on the outer front surface of the hot water storage tank 2 at intervals in the vertical direction.

[0014] The outer casing 3 forms the outer enclosure that houses the hot water storage tank 2. The outer casing 3 is made of rust-proofed steel plate (e.g., SPC material, SS material, etc.). The steel plate of the outer casing 3 is treated with rust-preventive coatings or hot-dip galvanizing, for example.

[0015] The outer box 3 is constructed in a vertically elongated box shape with a partition plate 3a located in front of the hot water storage tank 2, side plates located to the sides (omitted in Figure 1A), a rear plate 3c located behind, a top plate 3d located above, and a bottom plate 3e located below. As shown in Figure 1A, the partition plate 3a separates the foamed insulation material 6 that encloses the hot water storage tank 2 from the space in front of the partition plate 3a (the space in front of the partition plate 3a shown in Figure 1A houses hot water supply-related components 160, which consist of a part of the water supply pipe 11, a part of the water inlet pipe, a part of the hot water outlet pipe, a hot water supply pipe 14, a reheating pipe, mixing valves 16a and 16b, a shut-off valve, a pressure reducing valve, a bath pump, a water leak detection sensor, a control board, etc.).

[0016] The inner legs 4 statically support the hot water storage tank 2, which stores hot water within the outer casing 3. The inner legs 4 are positioned at approximately 120-degree intervals at the bottom of the hot water storage tank 2. One inner leg 4 is positioned at the front bottom of the hot water storage tank 2, while the other two inner legs 4 are positioned at the rear bottom left and right of the hot water storage tank 2. The number of inner legs 4 is not limited to the minimum of three that support a flat plate; there may be four or more. However, three is most preferable from the viewpoint of reducing material costs and weight. It is desirable that the inner legs 4 be positioned point-symmetrically with respect to the central axis of the hot water storage tank 2 when viewed from below.

[0017] Outer legs 7 are fixed to the underside of the bottom plate 3e of the outer box 3, in positions opposite to each inner leg 4. The outer legs 7 are fixed to the installation location G using anchor bolts or the like (not shown).

[0018] The foamed insulation material 6 is formed by injecting a foaming liquid (undiluted solution) into the space between the hot water storage tank 2 and the outer box 3 and allowing it to foam. For example, rigid polyurethane foam can be used as the foamed insulation material 6. Rigid polyurethane foam is obtained by reacting two urethane stock solutions, a polyol component and an isocyanate component, in the presence of a foaming agent, a catalyst, and a foam stabilizer. The foaming agent is a mixture of cyclopentane, water, carbon dioxide, etc. Note that the foamed insulation material 6 is not limited to rigid polyurethane foam. For example, urethane blocks, urethane plates, urethane sheets, etc., made from recycled waste material of the foamed insulation material 6 after foaming and hardening may be released (block shape, columnar shape, tank top / bottom mirror shape, tank body shape, pipe fixing, etc.) and placed in the filled portion of the foamed insulation material 6 in the hot water storage tank 2, or they may be placed as a flow suppression member for a portion of the urethane.

[0019] Furthermore, the foamed insulation material 6 may be replaced with a pre-molded insulation material such as polystyrene foam. In addition, a part of the hot water pipe 14 (water supply pipe 11) component connected to the elbow joint 17 may be integrally molded with the foamed insulation material 6 in advance using a mold.

[0020] A water supply pipe 11 (piping) is connected to the bottom of the hot water storage tank 2 to supply tap water that will become hot water. The water supplied to the bottom of the hot water storage tank 2 is introduced to a heat pump unit (not shown) via an inlet pipe by a pump (not shown). The hot water heated by the heat pump unit is introduced to the top of the hot water storage tank 2 via an outlet pipe.

[0021] In the hot water storage tank 2, the kinetic energy of the water molecules increases as you move from the bottom vertically upwards, resulting in a higher temperature. In other words, the temperature distribution within the hot water storage tank 2 is relatively low, medium, and high from the bottom to the top. For example, the temperature is approximately 90°C at the top of the tank and approximately 50°C in the middle.

[0022] The heat pump water heater (not shown) of this embodiment consists of a heat pump unit (not shown) that heats water and a hot water storage tank unit 1 that stores hot water. The heat pump unit includes a water-refrigerant heat exchanger that exchanges heat between a high-temperature, high-pressure refrigerant discharged from a variable-capacity compressor and water, which is the heating medium, and an evaporator (air-side heat exchanger) that exchanges heat between a low-temperature, low-pressure refrigerant discharged from an expansion valve that expands the refrigerant discharged from the water-refrigerant heat exchanger to a low-temperature, low-pressure state and air blown by a blower fan. These are connected in a ring shape. Carbon dioxide is used as the refrigerant in this refrigeration cycle. In the first embodiment, a heat pump unit was exemplified as a means of heating water, but other heating means such as resistance heating of an electric heater or heating by the combustion heat of gas may also be used.

[0023] The hot water from the top of the hot water storage tank 2 is supplied through the hot water supply pipe 14. The hot water from the hot water supply pipe 14 is mixed with water from a branch water supply pipe connected to the water supply pipe 11 via a mixing valve 16, and then dispensed from a hot water supply terminal (not shown). In the first embodiment, the case in which the hot water inside the hot water storage tank 2 is used at the hot water supply terminal was described as an example, but this may also be applied to a hot water storage tank unit (direct pressure hot water supply type, direct water supply connection type) in which the hot water from the hot water storage tank 2 is not used as the hot water at the hot water supply terminal, but rather used as a heat transfer medium to heat supplied water by heat exchange.

[0024] As described above, the outer casing 3 contains water supply pipes 11, inlet pipes, outlet pipes, and hot water supply pipes 14, which are connected to the hot water storage tank 2. These pipes (water supply pipes 11, inlet pipes, outlet pipes, and hot water supply pipes 14) are connected to other pipes and valves outside the outer casing 3. Note that the pipes (11, 14) described above are just examples and are not limited to this system.

[0025] Furthermore, the hot water storage tank unit 1 is equipped with a piping cover on the front (front side) of the outer casing 3. In Figure 1A, the piping cover is omitted. The piping, enclosed by partition plate 3a (see Figure 1A) and a pipe cover, houses the hot water outlet pipe leading from the heat pump unit to the hot water storage tank 2, branch water supply pipes (not shown), mixing valve 16, hot water supply pipe 14, control board (not shown), and other components.

[0026] Furthermore, injection ports 8 and 9 for injecting the foaming liquid of the foamed insulation material 6 are formed at the lower and upper parts of the partition plate 3a of the outer box 3. The injection ports 8 and 9 are closed with lids or the like after the foaming liquid of the foamed insulation material 6 is injected and foamed. Here, using Figure 1B (a front view of the partition plate 3a in Figure 1A), the arrangement of the multiple elbow joints 17 (described later) will be explained. Each elbow joint 17 installed on the partition plate 3a connects the internal piping connection pipes that protrude forward from the partition plate 3a to the various external piping connection pipes of the hot water supply related components 160 (hot water pipe, water supply pipe, hot water outlet pipe, branch (water supply, hot water, hot water outlet) pipes, valves (mixing valve, shut-off valve, pressure reducing valve), reheating heat exchanger, pump), etc., for use as a water heating return port 171a, water heating inlet 171b, hot water outlet pipe connection port 171c, relief valve connection port 171d, reheating heat exchanger outlet 171e, reheating heat exchanger inlet 171f, and drain pipe connection port 171g. Furthermore, each elbow joint 17 has a plate-shaped fixing member 17c integrally molded into it, and this fixing member 17c is equipped with positioning means for determining the reference position when attaching it to the partition plate 3a (a pair of rotation-preventing notches (anti-rotation parts) 17c2 are provided at the two diagonal corners). As a result, by installing each elbow joint 17 on the partition plate 3a, the configuration prevents overall misalignment when connecting the hot water supply-related components 160 to each external piping connection pipe.

[0027] Figure 2 is an enlarged perspective view of section I in Figure 1A. Figure 3 is an enlarged perspective view of section I in Figure 1A with the elbow joint 17 of the connecting fitting removed. The partition plate 3a is provided with a round hole 3a1 (heating return port 171a), which is a through-hole for connecting the hot water supply pipe 14 connected to the hot water storage tank 2 and the external hot water supply pipe 14g outside the partition plate 3a. The partition plate 3a is also provided with a round hole 3a2 (heating inlet 171b) (see Figure 3), which is a through-hole for connecting the water supply pipe 11 connected to the hot water storage tank 2 and the external water supply pipe 11g (see Figure 2) outside the partition plate 3a. In this embodiment, as an example of through-holes connecting the external water supply pipe 11g and the external hot water supply pipe 14g, the round holes 3a2 and 3a1 are shown as having the same shape. However, from the viewpoint of preventing incorrect insertion, the two round holes are not limited to having the same shape or diameter, but may be combined with different diameters, or they may be polygonal or oval (vertical and horizontal), or two elbow fittings 17 (described later) or a double elbow fitting 27 (described later) may be installed in one large hole (polygonal or oval (vertical and horizontal)). In other words, the partition plate 3a separates the foamed insulation material 6 from the space in front of it (the space in front of the partition plate 3a in Figure 1A), and is also provided with circular holes 3a1 and 3a2 as through holes.

[0028] As an example, the inner diameter s21 of the circular hole 3a1 and the inner diameter s22 of the circular hole 3a2 shown in Figure 3 have the same dimensions. This allows the use of the same sized elbow joint 17 (see Figures 4 and 9) described later for both circular holes 3a1 and 3a2.

[0029] Figure 4 is a perspective view showing an elbow joint 17 and a hot water pipe 14 connected to the elbow joint 17. As shown in Figure 2, the water supply pipe 11 connected to the hot water storage tank 2 (see Figure 1A) and the external water supply pipe 11g are connected via an elbow joint 17 (see Figure 4). Similarly, the hot water supply pipe 14 connected to the hot water storage tank 2 and the external hot water supply pipe 14g are connected via an elbow joint 17.

[0030] The water supply pipe 11 and the hot water supply pipe 14 are constructed using, for example, stainless steel pipes that are excellent in heat resistance, mechanical strength, and corrosion resistance. The elbow fitting 17, external water supply pipe 11g, and external hot water supply pipe 14g are resin pipes, such as those made of PPS (Polyphenylene sulfide) or PPE (Polyphenylene ether). Furthermore, the resin component (PPS, PPE) is not limited to virgin resin; it may also be a resin molded product composed of virgin resin and recycled resin, or a two-layer molded product (virgin resin on the inside of the pipe, recycled resin on the outside).

[0031] <Elbow joint 17> The elbow joint 17 is molded by injection molding using PPS, PPE, etc. PPS is an engineering plastic with excellent heat resistance and high mechanical strength over a wide temperature range. PPE is an engineering plastic with excellent mechanical and electrical properties, water absorption, etc. The elbow joint 17, the external water supply pipe 11g, and the external hot water supply pipe 14g may be made of any resin material other than PPS or PPE, as long as it has the necessary properties such as heat resistance and high mechanical strength used in the hot water storage tank unit 1.

[0032] The elbow joint 17 shown in Figure 4 is an elbow-shaped joint having a tank piping connection pipe 17a and an external piping connection pipe 17b. As an example, a plate-shaped fixing member 17c is integrally molded to the external piping connection pipe 17b of the elbow joint 17, but it may be a separate, detachable part, and the material is not limited to the same resin material (PPS, PPE), but may also be a plate-shaped fixing member made of metal (stainless steel). The rectangular plate-shaped fixing member 17c formed on the elbow joint 17 is used to fix the elbow joint 17 to the round holes 3a1 and 3a2 of the partition plate 3a. The shape of the fixing member 17c is not limited to a short shape as long as it can seal the round holes 3a1 and 3a2 to prevent the foam insulation material 6 from leaking out. It may also be a circle, ellipse, or polygon that is slightly larger than the round holes, or even a cushioning material such as a soft sealing material wrapped around it may be used as the fixing member instead of a plate shape. One end of the tank piping connection pipe 17a of the upper elbow fitting 17 shown in Figure 2 is connected to the hot water supply pipe 14 of the internal piping. The other end of the external piping connection pipe 17b of the elbow fitting 17 is connected to the external hot water supply pipe 14g of the external piping. One end of the tank piping connection pipe 17a of the lower elbow joint 17 shown in Figure 2 is connected to the water supply pipe 11 of the internal piping. The other end of the external piping connection pipe 17b of the elbow joint 17 is connected to the external water supply pipe 11g of the external piping. Other piping connections may also be provided at the hot water outlet connection port 171c, the relief valve connection port 171d, the reheating heat exchanger outlet 171e, the reheating heat exchanger inlet 171f, and the drain pipe connection port 171g, as shown in Figure 1B. For example, when each external piping connection pipe is connected to the internal piping of the hot water outlet connection port 171c or the relief valve connection port 171d, it is connected to the top of the hot water storage tank 2 via the partition plate 3a and elbow joint 17. On the outside of the partition plate 3a, there are various valves such as a mixing valve 16a for general hot water supply, a mixing valve 16b for bathtub hot water supply, and an electromagnetically operated ON / OFF shut-off valve (not shown). Similarly, when the external piping connection pipe is connected to the internal piping of the reheating heat exchanger outlet 171e and the reheating heat exchanger inlet 171f, it is connected via an elbow joint 17 through a partition plate 3a to one end of a heat exchanger (not shown) installed inside the hot water storage tank 2. The reheating pipe is equipped with a bath pump (not shown) that sends the bath water to the heat exchanger for circulation.

[0033] Figure 5A is a view taken in the direction of arrow II in Figure 4. Figure 5B is a view taken in the direction of arrow III in Figure 5A. Figure 5C is a view taken in the direction of arrow IV in Figure 5A. Figure 5D is a cross-sectional view of the VV section of Figure 5A.

[0034] <Left and right positioning ribs 17ci and upper and lower claw-shaped engaging portions 17cs of the elbow joint 17> The fixing member 17c of the elbow joint 17 shown in Figure 4 is composed of a rectangular plate 17c1 positioned near each of the round holes 3a1, 3a2 (see Figure 2) and projections (17ci, 17cs) for positioning.

[0035] As shown in Figures 4 and 5A, if there are three or more protrusions (17ci, 17cs), positioning in the left, right, up, and down directions is possible, but in the first embodiment, the case with four protrusions will be described. In the first embodiment, the protrusions (17ci, 17cs) shown in Figures 4 and 5B consist of a pair of positioning ribs 17ci on the left and right sides, and a pair of snap-fit ​​claw-shaped engaging parts 17cs on the top and bottom.

[0036] The positioning rib 17ci shown in Figures 4 and 5B is a plate-shaped rib having a tapered portion 17c3 that becomes lower as it moves from the center outward. As shown in Figure 2, when the elbow joint 17 to which the hot water pipe 14 is connected has a pair of upper and lower claw-shaped engaging portions 17cs that elastically deform toward the center and engage with the periphery of the round hole 3a1 of the partition plate 3a when the elbow joint 17 is inserted into the round hole 3a1 of the partition plate 3a from the rear (arrow α10 in Figures 3 and 8A). This temporarily fixes the elbow joint 17 to which the hot water pipe 14 is connected in the round hole 3a1.

[0037] At this time, the outer circumferential surface 17c5 (see Figure 5A) of the engaging portion 17cs of the elbow joint 17 to which the hot water pipe 14 is connected comes into contact with the inner circumferential surface 3a11 (see Figure 3) of the round hole 3a1, and the elbow joint 17 is positioned vertically within the round hole 3a1 of the partition plate 3a. At the same time, the left and right positioning ribs 17ci of the elbow joint 17 shown in Figure 5B have their outer circumferential surfaces 17c4 (see Figures 4 and 5B) in contact with the inner circumferential surface 3a11 (see Figure 3) of the round hole 3a1, thereby positioning the elbow joint 17 in the left-right direction of the round hole 3a1.

[0038] As a result, as shown in Figures 6 and 2, the elbow joint 17 to which the hot water pipe 14 is connected is positioned vertically and horizontally within the round hole 3a1 of the partition plate 3a. Figure 6 is a cross-sectional perspective view of the state before the external hot water supply pipe 14g is connected to the elbow joint 17 fixed to the partition plate 3a. Similarly, when the elbow joint 17 to which the water supply pipe 11 shown in Figure 2 is connected is inserted into the round hole 3a2 of the partition plate 3a from the rear (arrow α10 in Figures 3 and 8), the pair of claw-shaped engaging portions 17cs elastically deform toward the center and engage with the periphery of the round hole 3a2 of the partition plate 3a. This temporarily fixes the elbow joint 17 to which the water supply pipe 11 is connected in the round hole 3a2.

[0039] In this case, as shown in Figure 6, the outer circumferential surface 17c5 (see Figure 5A) of the engaging portion 17cs of the elbow joint 17 to which the water supply pipe 11 is connected comes into contact with the inner circumferential surface 3a21 (see Figure 3) of the round hole 3a2, thereby positioning the elbow joint 17 to which the water supply pipe 11 is connected in the round hole 3a2 of the partition plate 3a in the vertical direction. At the same time, the positioning rib 17ci of the elbow joint 17 to which the water supply pipe 11 shown in Figure 5B is connected, has its outer surface 17c4 (see Figures 4 and 5B) in contact with the inner surface 3a21 (see Figure 3) of the round hole 3a2, thereby positioning the elbow joint 17 to which the water supply pipe 11 is connected in the left-right direction of the round hole 3a2.

[0040] As a result, as shown in Figures 6 and 2, the elbow joint 17 to which the water supply pipe 11 is connected is positioned vertically and horizontally within the round hole 3a2 of the partition plate 3a. <Notch 17c2>

[0041] The rectangular plate 17c1 shown in Figures 4 and 5C has a pair of rotation-preventing notches (anti-rotation parts) 17c2 at the two diagonal corners. On the other hand, the partition plate 3a shown in Figure 2 has positioning projections p1 erected on it using press-fitted pins, screw-in bolts, male screws, etc. Note that the positioning projections p1 may be formed by cutting and bending during sheet metal forming or by drawing.

[0042] As shown in Figure 2, by bringing the notch 17c2 of the plate 17c1 into contact with the positioning projection p1 of the partition plate 3a, it is possible to prevent the elbow joint 17 from rotating around the horizontal axis relative to the partition plate 3a. In other words, the notch 17c2 of the elbow joint 17 forms an anti-rotation mechanism around the horizontal axis.

[0043] Alternatively, protrusions such as projections, pins, bolts, or male screws may be formed on the rectangular plate 17c1, and fitting holes may be formed in the partition plate 3a so that the protrusions of the plate 17c1 abut against each other, thereby forming an anti-rotation mechanism.

[0044] <Packing 19> Figure 7 is an enlarged side cross-sectional view showing the elbow joint 17 fixed to the partition plate 3a. Here, before filling the space between the hot water storage tank 2 and the outer box 3 shown in Figure 1A with foamed insulation material 6, annular packing 19 is set around the upper and lower engaging portions 17cs and the left and right positioning ribs 17ci of the fixing member 17c of the elbow joint 17, as shown in Figures 7 and 6. Similarly, annular packing 19 is set around the upper and lower engaging portions 17cs and the left and right positioning ribs 17ci of the fixing member 17c of the elbow joint 17 that is attached to the round hole 3a2 of the partition plate 3a. The packing 19 may be made of, for example, a flexible and stretchable industrial material, such as a soft insulating sheet. Alternatively, instead of providing the packing 19, a gap may be created, and the foamed polyurethane foam of the foamed insulating material 6 may be allowed to penetrate the gap, thereby forming an adhesive insulating member (packing 19) on the outer circumference between the fixing member 17c of the elbow joint 17 and the round hole 3a2 of the partition plate 3a. Figure 8A is a perspective cross-sectional view showing the state in which the elbow joint 17 to which the hot water supply pipe 14 connected to the hot water storage tank 2 is connected to the external hot water supply pipe 14g. Figure 8B is an enlarged side cross-sectional view showing the external hot water supply pipe 14g connected to the fixed elbow joint 17. As shown in Figures 8A and 8B, a front-to-back positioning space 20 is formed between the fixing member 17c and the partition plate 3a, in which foamed insulation material 6 is provided.

[0045] The annular packing 19 is a component that prevents the foamed insulation material 6 (see Figure 1A), which is filled between the outer box 3 and the hot water storage tank 2, from leaking out through the elbow joint 17 and the round holes 3a1 and 3a2 of the partition plate 3a shown in Figure 6. Thus, the foamed insulation material 6 is filled into the front-to-back positioning space 20 formed between the partition plate 3a and the fixing member 17c of the elbow joint 17, which is located outside the annular packing 19 shown in Figures 6 and 7. In other words, the front-to-back positioning space 20 corresponds to the space in which the thermal insulation material described in the claims (claims 2 and 3) is provided.

[0046] As shown in Figure 7, the front-to-rear positioning space 20 is an annular space having a cross-section with a front-to-rear dimension s31 of approximately 1.5 mm or more and a vertical dimension s32 of approximately 1.5 mm or more. If the front-to-rear positioning space 20 were to have a cross-section with a front-to-rear dimension s31 of approximately 1.0 mm or less and a vertical dimension s32 of approximately 1.0 mm or less, it would be difficult to fill the front-to-rear positioning space 20 with foamed insulation material 6 (see Figures 6 and 7) due to the viscosity of the foamed insulation material 6. In this way, foam insulation material 6 (see Figure 2) is filled between the upper and lower elbow joints 17 and the partition plate 3a, and the elbow joints 17 are positioned in the front-rear direction relative to the partition plate 3a.

[0047] <External hot water pipe 14g> As shown in Figure 6, an annular seal member fitting recess 14g1 is provided at one end of the external hot water supply pipe 14g. A seal member 14o, such as an O-ring, is fitted into the annular seal member fitting recess 14g1. On the central side of the sealing member insertion recess 14g1 at one end of the external hot water supply pipe 14g, a recessed space 14g2 is provided in an annular shape to prevent contact with a part of the elbow joint 17 when the external hot water supply pipe 14g is inserted into the elbow joint 17.

[0048] <Connection between the elbow joint 17 fixed to partition plate 3a and the external hot water supply pipe 14g> As shown in Figure 7, the flange hole 17b1 at one end of the external piping connection pipe 17b has an inner diameter s12 that is slightly larger than the outer diameter s13 (see Figure 8B) of the external hot water pipe connection part 14g7, which is the connection point of the external hot water pipe 14g to be connected.

[0049] Next, we will explain the procedure for connecting the elbow joint 17, which is fixed to the partition plate 3a, to the external hot water supply pipe 14g. As shown by arrow α11 in Figure 6, the worker grasps the external hot water supply pipe 14g with the sealing member 14o fitted to it and inserts it into the flange hole 17b1 of the external piping connection pipe 17b of the elbow joint 17 fixed to the partition plate 3a.

[0050] As shown in Figures 8A and 8B, the external hot water supply pipe 14g, which has a sealing member 14o fitted to it, is fixed by being inserted into the external piping connection pipe 17b of the elbow joint 17 fixed to the partition plate 3a.

[0051] Furthermore, the elbow joint 17 to which the water supply pipe 11 is connected and the external water supply pipe 11g are constructed in the same way as the elbow joint 17 to which the hot water supply pipe 14 is connected and the external hot water supply pipe 14g described above. The external water supply pipe 11g is then connected and fixed to the elbow joint 17, which is fixed to the round hole 3a2 of the partition plate 3a shown in Figure 6 (see Figure 2).

[0052] <Effects and Effects> According to the first embodiment, as shown in Figure 4, the fixing member 17c of the elbow joint 17 has, for example, a pair or multiple asymmetrical, diagonal, or otherwise positioning ribs 17ci on the left and right sides, and a pair or multiple asymmetrical, diagonal, or otherwise snap-fit ​​claw-shaped engaging parts 17cs on the top and bottom sides. Then, as shown in Figure 6, the external piping connection pipe 17b of the elbow joint 17 is fitted into the round hole 3a1 of the partition plate 3a from the rear. As a result, the upper and lower claw-shaped engaging parts 17cs engage with the outer edge of the round hole 3a1 of the partition plate 3a, and the outer surfaces 17c4 of the pair of left and right positioning ribs 17ci and the outer surfaces 17c5 of the upper and lower snap-fit ​​claw-shaped engaging parts 17cs come into contact with the round hole 3a1. This allows the elbow joint 17 to be precisely positioned in the up, down, left and right directions relative to the round hole 3a1 of the partition plate 3a. Specifically, the elbow joint 17, which is a pair of joint members shown in Figure 2, has three or more positioning protrusions that abut against the inner circumferential surfaces 3a11 and 3a21 of the through holes 3a1 and 3a2, respectively, to position the elbow joint 17 of the joint members in the left-right and up-down directions (in the first embodiment, the positioning protrusions have positioning ribs 17ci and engaging portions 17cs).

[0053] Furthermore, as shown in Figures 6 and 7, annular packings 19 are set around the upper and lower engaging portions 17cs and the left and right positioning ribs 17ci of the fixing member 17c of the elbow joint 17. Then, foam insulation material 6 (see Figures 1A and 2) is filled between the fixing member 17c on the outer circumference of the packing 19 and the partition plate 3a. In other words, a space is formed between the fixing member 17c and the partition plate 3a, on the outer periphery of the packing 19, which is a leak-preventing material, where the foamed insulation material 6, i.e., the insulation material, is provided. As a result, as shown in Figure 7, the front-to-back positioning of the partition plate 3a and the elbow joint 17 to which the hot water supply pipe 14 is connected can be precisely controlled. Similarly, the front-to-back positioning of the partition plate 3a and the elbow joint 17 to which the water supply pipe 11 is connected can be precisely controlled.

[0054] Furthermore, since the annular packing 19 is set around the round hole 3a1 of the partition plate 3a, and the foamed insulation material 6 is outside the annular packing 19 and filled between the fixing member 17c of the elbow joint 17 and the partition plate 3a, the elbow joint 17 can be positioned while maintaining a state in which it is pressed against the partition plate 3a in the front-rear direction by the foaming pressure of the foamed insulation material 6. As shown above, the elbow joint 17, to which the hot water supply pipe 14 and the external hot water supply pipe 14g are connected at both ends, can be precisely positioned in the up, down, left, right, front, and back directions within the round hole 3a1 of the partition plate 3a, as shown in Figures 6 and 7. Similarly, as shown in Figure 2, the elbow joint 17, to which the water supply pipe 11 and the external water supply pipe 11g are connected at both ends, can be precisely positioned in the up, down, left, right, front, and back directions within the round hole 3a2 of the partition plate 3a.

[0055] Furthermore, since the annular packing 19 is set around the round holes 3a1 and 3a2 of the partition plate 3a, the filled foam insulation material 6 does not leak out of the partition plate 3a. Furthermore, as shown in Figure 2, positioning protrusions p1 are erected on the front side of the partition plate 3a around the round hole 3a1 and the round hole 3a2, respectively. The rotation-preventing notch 17c2 of the elbow joint 17 is then brought into contact with the positioning protrusions p1.

[0056] This prevents the elbow joint 17 from rotating around the round holes 3a1 and 3a2 of the partition plate 3a (around the horizontal axis). With the above configuration around the elbow joint 17, the piping originating from the elbow joint can be precisely positioned in the front-to-back, up-down, left-to-right, and rotational directions. Therefore, it is possible to provide a water heater K that is less prone to misalignment of the piping and can suppress water leakage from the piping connection.

[0057] (Second Embodiment) As a second embodiment, the connection structure between the elbow joint 17 described in the first embodiment and the internal piping, which is either a hot water pipe 14 or a cold water pipe 11, will be described.

[0058] As shown in Figure 2, the hot water supply pipe 14 connected to the hot water storage tank 2 is fitted into the tank piping connection pipe 17a of the elbow joint 17. Then, a roughly U-shaped fixing pin 18 is inserted into the tank piping connection pipe 17a of the elbow joint 17, thereby fixing the hot water supply pipe 14 to the tank piping connection pipe 17a of the elbow joint 17. The elbow joint 17 to which the hot water pipe 14 is connected is then fitted into the round hole 3a1 of the partition plate 3a and secured with foam insulation material 6.

[0059] Here, the connection structure of the water supply pipe 11 connected to the tank piping connection pipe 17a of the elbow joint 17 fixed to the round hole 3a2 of the partition plate 3a is the same as the connection structure of the hot water supply pipe 14 connected to the tank piping connection pipe 17a of the elbow joint 17 fixed to the round hole 3a1 of the partition plate 3a. Therefore, in the second embodiment, the connection structure of the hot water supply pipe 14 connected to the tank piping connection pipe 17a of the elbow joint 17 will be described, and the explanation of the connection structure of the water supply pipe 11 connected to the tank piping connection pipe 17a of the lower elbow joint 17 will be omitted.

[0060] Figure 9 is a perspective view of the elbow joint 17 of the second embodiment, viewed from the front upper right. The upper end of the tank piping connection pipe 17a of the elbow joint 17 has a tubular piping connection portion 17a1 and a tubular pin-insertion piping portion 17a2 formed therein.

[0061] Figure 10 is a longitudinal cross-sectional view taken in the direction of arrow VI in Figure 2, showing the state in which the hot water supply pipe 14 is fitted into and fixed to the tank piping connection pipe 17a of the elbow joint 17. The pipe connection section 17a1 shown in Figure 10 is where the hot water supply pipe 14 (see Figure 3) is fitted and fixed. The pipe connection section 17a1 is a pipe having an inner diameter s22 (see Figure 10) that is slightly larger than the outer diameter s21 (see Figure 3) of the tip section 14s of the hot water supply pipe 14, and an outer diameter s23 (see Figure 10).

[0062] The pin-insertion piping section 17a2 has an inner diameter s30 that is the same as the inner diameter s22 of the pipe connection section 17a1, as well as a larger inner diameter s31. Furthermore, the pin-insertion piping section 17a2 has an outer diameter s32 that is larger than the outer diameter s23 of the pipe connection section 17a1. As shown in Figure 9, the pin-insertion piping section 17a2 is provided with a mounting hole 17a21 for inserting the fixing pin 18 from the side.

[0063] A mounting surface step 17ad (see Figures 9 and 10) is formed between the inner diameter s30 (see Figure 10) and the outer diameter s32 of the pin-inserted piping section 17a2. A fixing pin 18 (see Figure 11) for securing the hot water supply pipe 14 inserted into the piping connection section 17a1 is attached to the mounting surface step 17ad. Figure 11 is a top view of the fixing pin 18. A pin gripping area 17ae (see Figures 12 and 14) is formed in a part of the mounting surface step 17ad, on which the U-shaped gripping portion 18c (see Figure 11) of the fixing pin 18 is mounted.

[0064] Figure 12 is an enlarged perspective cross-sectional view of the VII-VII section of Figure 10, viewed from diagonally above. By forming the pin gripping region 17ae, the outer circumferential surface 18c1 (see Figure 11) of the U-shaped gripping portion 18c of the fixing pin 18 can be almost housed within the tank piping connection pipe 17a of the elbow joint 17 (see Figures 12 and 14).

[0065] <Fixing pin 18> The fixing pin 18 shown in Figure 11 is a component that secures the tip 14s (see Figure 3) of the hot water supply pipe 14, which is fitted into the elbow joint 17, so that it does not come out of the elbow joint 17. The fixing pin 18 has a filament formed in a roughly U-shape. The fixing pin 18 is manufactured using spring steel (for example, SUS304) which has high hardness and strong toughness. The fixing pin 18 has insertion tip portions 18a, 18a, a pipe restraining arc portion 18b, and a U-shaped gripping portion 18c. The distance s42 between the insertion tip portions 18a, 18a of the fixing pin 18 and the distance s43 between the two arms of the U-shaped gripping portion 18c are both shorter than the outer diameter s20 (Figure 3) of the hot water pipe 14. This allows the fixing pin 18 to restrain the tip portion 14s of the hot water pipe 14 so that it does not come out of the elbow joint 17.

[0066] Furthermore, the diameter of the pipe restraint arc portion 18b is equivalent to or slightly larger than the outer diameter s20 of the hot water supply pipe 14 (see Figure 3). The side circumferential wall 17a20 of the pin-insertion piping section 17a2 of the elbow joint 17 shown in Figure 9 has a mounting hole 17a21 through it for inserting a fixing pin 18. The fixing pin 18 can be inserted into the pin-insertion piping section 17a2 from the side through the mounting hole 17a21 of the pin-insertion piping section 17a2.

[0067] <How to connect the hot water pipe 14 to the elbow fitting 17> Next, we will explain how to connect the hot water pipe 14 to the elbow joint 17, as shown in Figure 2.

[0068] In Figure 3, two annular grooves 14s1 are formed in the tip portion 14s of the hot water supply pipe 14, and sealing members 14o, such as O-rings, are fitted into these grooves by elastic deformation. Next, the tip 14s (see Figure 3) of the hot water supply pipe 14, to which the sealing member 14o is fitted, is inserted into the tank piping connection pipe 17a of the elbow joint 17, as shown by arrow α21 in Figure 4.

[0069] Figure 13 is a perspective view taken from the upper left rear, showing the process of connecting the hot water pipe 14 to the tank piping connection pipe 17a of the elbow joint 17. In Figure 13, the hot water pipe 14 is shown as a dashed line (imaginary line) for ease of understanding. Next, as shown in Figure 13, the U-shaped gripping portion 18c (see Figure 11) of the fixing pin 18 is grasped and inserted into the mounting hole 17a21 of the pin-inserted piping portion 17a2 of the elbow joint 17 into which the tip portion 14s of the hot water pipe 14 is inserted. Then, the insertion tip portion 18a, 18a, the pipe restraining arc portion 18b, and the U-shaped gripping portion 18c of the fixing pin 18 elastically deform outward, and the pipe restraining arc portion 18b is fixed above the tip portion 14s of the hot water pipe 14 (see Figures 10 and 12).

[0070] Subsequently, as shown in Figures 1 and 2, the foaming liquid of the foamed insulation material 6 is injected from inlets 8 and 9 into the outer box 3 and partition plate 3a that house the hot water storage tank 2, and the foamed insulation material 6 is filled and fixed between the outer box 3 and the hot water storage tank 2 (see Figures 2 and 1). In this process, the foamed insulation material 6 also enters the connection between the tank piping connection pipe 17a and the hot water supply pipe 14 of the elbow joint 17 shown in Figures 2 and 10. This ensures that the fixing pin 18 is securely fixed to the connection between the tank piping connection pipe 17a and the hot water supply pipe 14 of the elbow joint 17.

[0071] Unlike the second embodiment described above, when the tank piping connection pipe 17a of the elbow joint 17 and the hot water supply pipe 14 are connected with a quick fastener, the following disadvantages exist: The quick fastener may come off due to the foaming pressure when the foam insulation material 6 is filled. Also, it may be difficult to determine whether the quick fastener is completely detached or partially inserted when the foam insulation material 6 is filled. In addition, a gap may easily form at the joint between the tank piping connection pipe 17a of the elbow joint 17 and the hot water supply pipe 14. Therefore, there is a potential possibility of water leakage from the connection point between the tank piping connection pipe 17a of the elbow joint 17 and the hot water supply pipe 14.

[0072] Figure 14 is a perspective view showing the state after the fixing pin 18 has been inserted through the mounting hole 17a21 of the pin insertion pipe section 17a2 of the elbow joint 17, following the connection of the tank piping connection pipe 17a to the hot water supply pipe 14. When the fixing pin 18 is installed, the outer surface of the side wall 17a20 of the pin-inserted piping section 17a2 and the outer surface 18c1 of the U-shaped gripping section 18c of the fixing pin 18 are configured to be approximately the same plane or on the same plane. As a result, the U-shaped gripping section 18c of the fixing pin 18 is prevented from protruding outward from the tank piping connection pipe 17a of the elbow joint 17.

[0073] A sloping recess 17a22 is provided in the upper center of the mounting hole 17a21 of the pin-insertion piping section 17a2, which slopes downward from top to bottom towards the center. When removing the fixing pin 18 before filling with foam insulation material 6, a flathead screwdriver (not shown) can be inserted into the inclined recess 17a22 shown in Figure 14, into the inside of the U-shaped gripping portion 18c of the fixing pin 18, and the U-shaped gripping portion 18c of the fixing pin 18 can be pulled outward, thereby removing the fixing pin 18 from the pin-inserted piping portion 17a2 of the elbow joint 17.

[0074] <Effects and Effects> According to the second embodiment, as shown in Figure 13, the tip portion 14s (see Figure 3) of the hot water supply pipe 14 is inserted into the pipe connection portion 17a1 of the elbow joint 17, and then the fixing pin 18 is inserted through the mounting hole 1a21 of the pin-insertion pipe portion 17a2 and elastically deformed to fix the tip portion 14s (see Figure 3) of the hot water supply pipe 14 to the central portion 14c (see Figure 14) of the hot water supply pipe by elastic force. At this time, as shown in Figure 14, the fixing pin 18 is constrained in the vertical direction by the pin-insertion pipe portion 17a2. In addition, in the left-right and front-back directions, the dimension s42 between the insertion tips 18a, 18a of the fixing pin 18 shown in Figure 11 and the dimension s43 between the two arms of the U-shaped grip portion 18c are both shorter than the outer diameter s20 (see Figure 3) of the hot water supply pipe 14, so that the fixing pin 18 is fixed around the hot water supply pipe 14 by the elastic force of the fixing pin 18. The fixing pin 18 is restrained in the left, right, front, and rear directions by the elastic force of the fixing pin 18. Therefore, the tip 14s of the hot water supply pipe 14 (see Figure 3) can be securely restrained to the tank piping connection pipe 17a of the elbow joint 17.

[0075] In addition, after inserting the hot water supply pipe 14 into the tank piping connection pipe 17a of the elbow joint 17 and inserting the fixing pin 18 through the mounting hole 1a21 of the pin insertion piping section 17a2, foam insulation material 6 (see Figures 1A and 2) is filled in, so the fixing pin 18 is fixed above the tip 14s of the hot water supply pipe 14 by the foam insulation material 6. As a result, the fixing pin 18 is tightly and securely fixed above the tip 14s of the hot water supply pipe 14 that is inserted into the piping connection section 17a1. Similarly, the tip 11s of the water supply pipe 11 (see Figure 3) is fitted into the pipe connection portion 17a1 of the elbow joint 17 and secured tightly and firmly by the fixing pin 18 and the foam insulation material 6. Therefore, the connection and fixing of the elbow joint 17 and the hot water pipe 14 can be performed with high strength and reliability. Thus, a water heater K can be provided that can reliably suppress water leakage from the pipe connections between the elbow joint 17 and the hot water pipe 14, and between the elbow joint 17 and the cold water pipe 11.

[0076] (Third embodiment) Figure 15 is a perspective view of the W elbow joint 27 according to the third embodiment, viewed from the front right. The W elbow joint 27 of the third embodiment may, for example, be formed vertically with a first elbow joint 17A having the same configuration as the elbow joint 17 of the first and second embodiments, and a second elbow joint 17B having the same configuration as the elbow joint 17 of the first and second embodiments but arranged upside down, and the fixing members for the two first and second elbow joints 17A and 17B may be formed as a single fixing member 17C. However, it is not limited to the vertical arrangement in an upside-down position, and may be arranged in any position such as left and right, diagonally, asymmetrically, or in multiples. Furthermore, the fixing member 17C may be made detachable so that the mounting direction and rotation direction (up, down, left, right) of the first elbow joint 17A and the second elbow joint 17B can be arbitrarily set.

[0077] Since the other components are the same as those in the first and second embodiments, similar components are denoted by the same reference numerals, and detailed descriptions are omitted. The W-elbow fitting 27 is a resin pipe, similar to the first and second embodiments, and is made of materials such as PPS or PPE. The W-elbow joint 27 is integrally molded by injection molding. Alternatively, the W-elbow joint 27 may be formed in sections and then joined together by welding using ultrasonic waves or the like.

[0078] The W-elbow fitting 27 is assembled to the partition plate 3a as follows. Similar to Figure 6, the annular packing 19 (see Figure 6) of the first elbow joint 17A is fitted into the round hole a1 of the partition plate 3a, and the annular packing 19 (see Figure 6) of the first elbow joint 17A is fitted into the annular packing 19 (see Figure 6) of the second elbow joint 17B is fitted into the round hole a2 of the partition plate 3a. Then, the annular packing 19 (see Figure 6) of the second elbow joint 17B is fitted into the annular packing 17b of the second elbow joint 17B. The annular packing 19 (see Figure 6) of the second elbow joint 17B is fitted into the round hole a1 of the partition plate 3a, and the annular packing 19 (see Figure 6) of the second elbow joint 17B is fitted into the round hole a2 of the partition plate 3a. Furthermore, after the external piping connection pipe 17b of the second elbow joint 17B is positioned in the round hole a2 of the partition plate 3a by the left and right positioning ribs 17ci and the upper and lower claw-shaped engaging parts 17cs of the lower part of the fixing member 17C, it is then clamped by the upper and lower claw-shaped engaging parts 17cs.

[0079] Then, similar to Figure 7, foam insulation material 6 is filled between the partition plate 3a and the fixing member 17C on the outer circumference of the left and right positioning ribs 17ci and the upper and lower claw-shaped engaging portions 17cs. This positions the W elbow joint 27 in the front-to-back and left-to-right directions relative to the partition plate 3a.

[0080] <Effects and Effects> According to the third embodiment, the external piping connection pipe 17b of the first elbow joint 17A of the W elbow joint 27 is fitted into the round hole a1 of the partition plate 3a from the rear, and the external piping connection pipe 17b of the second elbow joint 17B of the W elbow joint 27 is fitted into the round hole a2 of the partition plate 3a from the rear, so that rotational positioning with respect to the front-rear axis can be performed.

[0081] Furthermore, it provides the same effects and advantages as the first and second embodiments. In the third embodiment, a configuration was described in which the fixing member 17C is common and the first elbow joint 17A and the second elbow joint 17B are provided. However, a configuration may also be provided in which one common fixing member 17C is used and three or more elbow joints (17A, 17B). This allows for rotational positioning of the multiple elbow joints relative to the partition plate 3a.

[0082] (Fourth Embodiment) Figure 16 is a longitudinal cross-sectional view showing the state in which the pipe 24 is fitted into and fixed in the pipe connecting pipe 27a of the joint 37 of the fourth embodiment. The fourth embodiment applies the connection structure between the internal piping (11, 14) and the elbow joint 17 in the second embodiment to general piping 24 and general joint 37. The other components are the same and are therefore indicated by reference numerals in the 20s.

[0083] Similar to Figure 9, the upper end of the joint 37 is formed with a tubular pipe connection portion 27a1 and a tubular pin-insertion pipe portion 27a2. Note that the fixing member 17c shown in Figure 9 may or may not be provided on the joint 37.

[0084] The pipe connection section 27a1 shown in Figure 16 is the point where the tip 24s of the pipe 24 is fitted and fixed. The pipe connection section 27a1 is a pipe having an inner diameter s52 that is slightly larger than the outer diameter s51 (see Figure 16) of the tip section 24s of the pipe 24, and an outer diameter s53. The pin-inserted piping section 27a2 has an inner diameter s50 that is the same as the inner diameter s52 of the piping connection section 27a1, and an inner diameter s61 that is larger than the inner diameter s52 of the piping connection section 27a1. In addition, the pin-inserted piping section 27a2 has an outer diameter s62 that is larger than the outer diameter s53 of the piping connection section 27a1, excluding one end.

[0085] Between the inner diameter s50 and outer diameter s62 of the pin-inserted piping section 27a2, a mounting surface step portion 27ad (see Figure 16) is formed on which a fixing pin 28 (see Figure 17), which has substantially the same shape as the fixing pin 18 (see Figure 11), is placed.

[0086] Figure 17 is a top view of the fixing pin 28 of the fourth embodiment. The fixing pin 28 shown in Figure 17 is a component that is inserted (attached) above the tip 24s (see Figure 16) of the pipe 24 that is fitted into the joint 37 to fix it in place and prevent it from coming out of the joint 37. The fixing pin 28, like the fixing pin 18 shown in Figure 11, has a wire made of spring steel or the like formed into a roughly U-shape.

[0087] The fixing pin 28 has insertion tip portions 28a, 28a, a pipe restraining arc portion 28b, and a U-shaped gripping portion 28c. The distance s72 between the insertion tip portions 28a, 28a of the fixing pin 28 and the distance s73 between the two arms of the U-shaped gripping portion 18c are both shorter than the outer diameter s80 of the pipe 24 (see Figure 16). Also, the diameter dimension s71 of the pipe restraining arc portion 28b shown in Figure 17 is equal to or slightly larger than the outer diameter s80 of the pipe 24 (Figure 16).

[0088] Similar to Figure 12, the side circumferential wall 27a20 (see Figure 16) of the pin-insertion piping section 27a2 has mounting holes similar to the mounting holes 17a21 (see Figure 12) for inserting the fixing pin 28. The fixing pin 28 can be inserted into the pin-insertion piping section 27a2 from the side through the mounting holes in the pin-insertion piping section 27a2. Furthermore, a pin gripping area similar to the pin gripping area 17ae (see Figure 14) on which the U-shaped gripping portion 28c of the fixing pin 28 is placed is formed on a portion of the mounting surface step portion 27ad of the joint 37. The presence of the pin gripping area allows the U-shaped gripping portion 28c of the fixing pin 28 to be almost completely housed within the pipe connection pipe 27a of the joint 37.

[0089] As a result, as shown in Figure 16, the fixing pin 28 is attached above the tip 24s of the pipe 24, similar to Figures 12 and 13, thereby restraining the tip 24s of the pipe 24 from coming out of the joint 37.

[0090] <How to connect pipe 24 to fitting 37> Next, we will explain how to connect the pipe 24 shown in Figure 16 to the fitting 37. A sealing member 24o, such as an O-ring, is elastically deformed and fitted into each of the two annular grooves 24s1 at the tip 24s of the pipe 24. Next, the tip portion 24s (see Figure 16) of the pipe 24 with the sealing member 24o fitted is inserted into the pipe connection portion 27a1 of the pipe connecting pipe 27a of the joint 37, as shown by arrow α31 in Figure 16.

[0091] Next, grasp the U-shaped gripping portion 28c of the fixing pin 28 shown in Figure 17 and insert it into the mounting hole of the pin-inserted pipe portion 27a2 of the joint 37 to which the tip portion 24s of the pipe 24 is connected, similar to Figure 12. Then, the insertion tip portion 28a, 28a, pipe restraining arc portion 28b, and U-shaped gripping portion 28c of the fixing pin 28 shown in Figure 17 elastically deform outward, and the pipe restraining arc portion 28b is fixed to the pipe 24 above the tip portion 24s of the pipe 24 (see Figure 16).

[0092] As shown in Figure 16, when the fixing pin 28 is attached to the joint 37, the outer surface of the side wall 27a20 of the pin-inserted piping section 27a2 and the outer surface 28c1 (see Figure 17) of the U-shaped gripping portion 28c of the fixing pin 28 are configured to be almost on the same plane (nearly on the same plane). Therefore, the U-shaped gripping portion 28c (see Figure 17) of the fixing pin 28 is prevented from protruding outward from the outer surface of the piping connection pipe 27a of the joint 37.

[0093] Subsequently, if foam insulation material is filled around the connection point between the pipe 24 and the fitting 37, or if molded insulation material is placed, the fixing pin 28 is securely fixed by the connection point between the pipe connecting pipe 27a of the fitting 37 and the pipe 24.

[0094] Here, in the upper center of the mounting hole for the pin-inserted piping section 27a2, there is a recessed inclined area that slopes from top to bottom toward the center, similar to the inclined recess 17a22 in Figure 14. Before filling with foam insulation or before placing molded insulation, when removing the fixing pin 28 shown in Figure 16, insert a flathead screwdriver (not shown) into the inclined recess and pry it into the inside of the U-shaped grip portion 28c (see Figure 17) of the fixing pin 28, and pull the U-shaped grip portion 28c of the fixing pin 28 outwards. This will allow you to remove the fixing pin 28 from the pin-inserted piping portion 27a2 of the joint 37.

[0095] <Effects and Effects> According to the fourth embodiment, similar to Figure 13, after the fitting 37 shown in Figure 16 is fitted into the pipe connection pipe 27a, the fixing pin 28 is inserted through the mounting hole of the pin-fitting pipe section 27a2 and elastically deformed to fix the pin-fitting pipe section 27a2 of the fitting 37, which is located above the tip 24s (see Figure 16) of the pipe 24, by elastic force. In this case, similar to Figure 14, the fixing pin 28 is constrained in the vertical direction by the pin-fitting pipe section 27a2. In the left-right and front-back directions, the dimension s72 between the insertion tips 28a, 28a of the fixing pin 28 shown in Figure 17 and the dimension s73 between the two arms of the U-shaped gripping section 18c are both shorter than the outer diameter s80 (see Figure 16) of the pipe 24. Therefore, the fixing pin 28 is fixed around the pipe 24 by its own elastic force (=EI).

[0096] Therefore, the tip 24s of the pipe 24 can be securely restrained to the pipe connection portion 27a1 of the fitting 37. Furthermore, by inserting the tip 24s of the pipe 24 into the pipe connection portion 27a1 of the fitting 37, and inserting the fixing pin 28 through the mounting hole of the pin-inserting pipe portion 27a2, and then filling with foam insulation material or placing molded insulation material, the fixing pin 28 is tightly and securely fixed to the pipe connection pipe 27a of the fitting 37. As a result, the connection between the fitting 37 and the pipe 24 can be made with high strength and reliability.

[0097] Therefore, water leakage from the connection between the joint 37 and the pipe 24 can be reliably suppressed. Furthermore, the connection between the joint 37 and the pipe 24 may be constructed without filling it with foamed insulation material or placing molded insulation material.

[0098] <<Other Embodiments>> 1. In the fourth embodiment, the case in which the joint 37 and the pipe 24 are connected was described, but the end of one pipe 24 and the end of the other pipe 38 (see Figure 16), or the end of one joint 39 (see Figure 16) and the end of the other joint 40 (see Figure 16) may be configured in the same way as in the fourth embodiment and connected to each other. The area around the end of one pipe 24 and the end of the other pipe 38, or the end of one joint 39 and the end of the other joint 40, may or may not be covered with an insulating material such as foamed insulation or molded insulation.

[0099] 2. The present invention is not limited to the configuration of the embodiments described above, and various modifications and specific forms are possible within the scope of the appended claims. [Explanation of symbols]

[0100] 1. Hot water storage tank unit 2. Hot water storage tank 3. Outer box 3a Partition plate 3a1 Round hole (through hole) 3a11, 3a21 Inner surface 3a2 Round hole (through hole) 6. Foamed insulation material (insulation material) 11 Water supply pipes (internal piping, piping) 11g External water supply pipe (external piping, piping) 14. Hot water pipes (internal piping, pipes) 14g External hot water supply pipe (external piping, plumbing) 14s The end of the hot water pipe (the end of the internal piping) 17 Elbow joint (joint component) 17a2 Pin insertion piping part (wire rod insertion piping part) 17a21 Mounting hole (wire insertion hole) 17a Tank piping connection pipe (one-sided piping connection pipe) 17b External piping connection pipe (other side piping connection pipe) 17c Fixing member 17c2 Notch (anti-rotation part) 17C Fixing member 17ci Positioning rib (positioning projection, convex projection) 17cs Engaging projection (positioning projection, engaging part) 18 Fixing pins (fixing wires) 18a Insertion tip 18b Pipe restraint arc 18c U-shaped grip part 19. Packing (leak-proof material) 20 Positioning space in the front-rear direction (space) s20 Outer diameter of hot water supply pipe (outer diameter of internal piping, outer diameter of pipe) s42 Dimensions between insertion tips s43 Distance between both arms (distance between the ends of the U-shaped gripping section) 27 W-elbow fitting (fitting component) 37, 39, 40 Joints (joint components) 38 Piping

Claims

1. Hot water storage tank and An outer box housing the aforementioned hot water storage tank, Internal piping connected to the aforementioned hot water storage tank, External piping connected to the aforementioned internal piping, An insulating material is provided between the outer box and the hot water storage tank, A partition plate is provided, which separates the aforementioned insulating material from the space in front of it, and has through holes. The system includes a tubular joint member, one end of which is connected to the internal piping and the other end of which is connected to the external piping. The joint member has three or more positioning protrusions that contact the inner circumferential surface of the through hole and position the joint member in the left-right and up-down directions. A hot water storage tank unit characterized by the following features.

2. Hot water storage tank and An outer box housing the aforementioned hot water storage tank, Internal piping connected to the aforementioned hot water storage tank, External piping connected to the aforementioned internal piping, An insulating material is provided between the outer box and the hot water storage tank, A partition plate is provided, which separates the aforementioned insulating material from the space in front of it, and has through holes. The system includes a tubular joint member, one end of which is connected to the internal piping and the other end of which is connected to the external piping. The joint member has a fixing member positioned opposite the partition plate, A space is formed between the fixing member and the partition plate in which the insulating material is provided. A hot water storage tank unit characterized by the following features.

3. In the hot water storage tank unit according to claim 1, The joint member has a fixing member positioned opposite the partition plate, A space is formed between the fixing member and the partition plate in which the insulating material is provided. A hot water storage tank unit characterized by the following features.

4. In the hot water storage tank unit according to claim 2, A leakage prevention material is placed between the periphery of the through hole and the fixing member. A space is formed between the fixing member and the partition plate, where the heat insulating material is provided on the outer periphery of the leakage prevention material. A hot water storage tank unit characterized by the following features.

5. In the hot water storage tank unit according to claim 1 or claim 3, The positioning projection consists of a claw-shaped engaging projection and a convex projection. A hot water storage tank unit characterized by the following features.

6. In the hot water storage tank unit according to claim 1 or claim 3, The positioning projection comprises a pair of claw-shaped engaging projections positioned on either side of the through-hole, and a convex projection positioned on either side of the through-hole. A hot water storage tank unit characterized by the following features.

7. In the hot water storage tank unit according to claim 1 or claim 2, The aforementioned joint member has an anti-rotation portion. A hot water storage tank unit characterized by the following features.

8. Hot water storage tank and An outer box housing the aforementioned hot water storage tank, Multiple internal pipes connected to the aforementioned hot water storage tank, External piping for hot water supply routes, hot water outlet routes, cold water supply routes, and branch routes, including multiple hot water supply-related components connected to the internal piping, An insulating material is provided between the outer box and the hot water storage tank, A partition plate is provided to separate the aforementioned insulating material from the space in front of it, and to have multiple through holes. The system comprises a plurality of tubular joint members, one end of which is connected to the plurality of internal pipes, and the other end of which is connected to the external pipes of the hot water supply route, hot water outlet route, cold water supply route, and branch route, which include the plurality of hot water supply-related components. Each of the multiple tubular joint members connected to the external pipes has a positioning means that uses three or more positioning protrusions that abut against the inner circumferential surface of the multiple through holes and position the multiple joint members in the left-right and up-down directions. The position where the other end of each connecting combination connection with each external pipe, including the hot water supply route, hot water outlet route, cold water supply route, and branch route, which include the multiple hot water supply related components, is in contact with the aforementioned hot water supply related components. A hot water storage tank unit characterized by the following features.

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