JP2021110495A - Hot water storage type water heater, heat insulation material mold, and heat insulation material manufacturing method - Google Patents

Abstract

To provide a hot water storage type water heater which is advantageous in preventing an underfill part from generating during molding of a urethane foam heat insulation material having an avoidance hole in which a pipeline connected to a hot water storage tank is inserted, to provide a heat insulation material mold, and to provide a heat insulation material manufacturing method.SOLUTION: A hot water storage type water heater includes: a cylindrical hot water storage tank 1; an outer case for storing the hot water storage tank 1; a pipeline connected to the hot water storage tank 1; and a urethane foam heat insulation material (front surface heat insulation material 14) for covering the hot water storage tank 1 in the outer case. The urethane foam heat insulation material includes: an inner wall surface facing the hot water storage tank; an outer wall surface 14b facing the opposite side from the inner wall surface; and an avoidance hole 19 penetrating from the inner wall surface to the outer wall surface 14b, and for passing the pipeline. The avoidance hole 19 includes: an outside opening 19b which opens on the outer wall surface 14b; and an inside opening which opens on the inner wall surface. The shape of the outside opening 19b is an elliptical shape.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a hot water storage type water heater, a heat insulating material molding mold, and a heat insulating material manufacturing method.

Conventionally, styrofoam has been the mainstream as a material for a heat insulating material that covers a hot water storage tank of a hot water storage type water heater, but in recent years, urethane foam heat insulating material having higher heat insulating performance has been attracting attention. According to Patent Document 1 below, in the lower mold of a foam molding mold for molding a polyurethane foam, when the polyurethane raw material injected into the lower bottom surface of the lower mold flows and spreads on the bottom surface of the lower mold at the corner where the wall surfaces intersect. It is disclosed that a flow velocity adjusting portion is provided so that the flow of the raw material in the central portion flowing toward the corner portion is faster than the flow of the raw material on the outer side thereof.

Japanese Unexamined Patent Publication No. 2008-213160

The heat insulating material that covers the hot water storage tank needs to be provided with an avoidance hole through which a pipe connected to the hot water storage tank is passed. As a problem when using urethane foam insulation as a heat insulating material to cover the hot water storage tank, when the urethane raw material is injected into the mold to foam and mold, the urethane raw material spreads over the entire mold due to the influence of unevenness in the mold. There is a problem that the heat insulating performance and the appearance are affected by the lack of meat in the molded product due to the lack of spread. For example, the lower mold of the mold for molding the heat insulating material is provided with a convex portion for forming an avoidance hole, and the convex portion comes into contact with the upper mold when the mold is closed. Therefore, the convex portion becomes an obstacle to the flow of the urethane raw material, and a thin portion is likely to occur in the molded product.

The present disclosure has been made to solve the above-mentioned problems, and in order to prevent a missing portion from being generated during molding of a urethane foam heat insulating material having an avoidance hole through which a pipe connected to a hot water storage tank is passed. It is an object of the present invention to provide a hot water storage type water heater, a heat insulating material molding mold, and a heat insulating material manufacturing method, which are advantageous in the above.

The hot water storage type water heater according to the present disclosure includes a cylindrical hot water storage tank, an outer case for storing the hot water storage tank, a pipe connected to the hot water storage tank, and a urethane foam heat insulating material that covers the hot water storage tank in the outer case. The urethane foam heat insulating material has an inner wall surface facing the hot water storage tank, an outer wall surface facing the opposite side of the inner wall surface, and an avoidance hole for penetrating from the inner wall surface to the outer wall surface to allow piping to pass through. The hole has an outer opening that opens to the outer wall surface and an inner opening that opens to the inner wall surface, and the shape of the outer opening is elliptical.
The heat insulating material molding die according to the present disclosure is a heat insulating material molding die that molds a urethane foam heat insulating material that covers a cylindrical hot water storage tank, and forms an avoidance hole penetrating from an inner wall surface to an outer wall surface of the urethane foam heat insulating material. The convex part of the mold for the purpose is projected from the inner surface of the mold of the heat insulating material molding mold, and the shape of the convex part of the mold is a cone shape in which the cross-sectional area perpendicular to the protruding direction gradually decreases as the distance from the inner surface of the mold increases. It exhibits, or exhibits an elliptical columnar shape having an elliptical cross section whose major axis is the direction along the flow direction of the urethane raw material in a cross section perpendicular to the protruding direction.
The heat insulating material manufacturing method according to the present disclosure is a heat insulating material manufacturing method in which a urethane foam heat insulating material covering a cylindrical hot water storage tank is molded by a heat insulating material molding die, and penetrates from an inner wall surface to an outer wall surface of the urethane foam heat insulating material. The convex portion of the mold for forming the avoidance hole protrudes from the inner surface of the mold of the heat insulating material molding mold, and the convex portion of the mold has an elliptical cross-sectional shape perpendicular to the protruding direction of the convex portion of the mold. The urethane raw material is injected so that the urethane raw material flows along the longitudinal direction of the oval shape in the vicinity.

According to the present disclosure, a hot water storage type water heater and a heat insulating material molding mold, which are advantageous in preventing the occurrence of a missing portion during molding of a urethane foam heat insulating material having an avoidance hole through which a pipe connected to a hot water storage tank is passed. , And a method for producing a heat insulating material can be provided.

It is a front view which shows the hot water storage type water heater according to Embodiment 1. FIG. It is a perspective view of the hot water storage tank provided in the hot water storage type water heater according to Embodiment 1. FIG. It is an exploded perspective view of the hot water storage tank and the heat insulating material covering the hot water storage tank. It is a perspective view which shows the state which the hot water storage tank is covered with a heat insulating material. It is a perspective view of the front insulation material. It is a front view of the front insulation material. It is sectional drawing of the front insulation material. It is a figure which shows a part of the lower mold of the heat insulating material molding mold by Embodiment 1. FIG.

Hereinafter, embodiments will be described with reference to the drawings. The elements common to or corresponding to each other in the drawings are designated by the same reference numerals to simplify or omit the description. In addition, when referring to an angle in the present disclosure, when there is a superior angle and an inferior angle in which the sum is 360 degrees, in principle, the angle of the inferior angle is referred to. In the following description, the description of "water" means, in principle, liquid water, and may include low-temperature water to high-temperature hot water.

Embodiment 1.
FIG. 1 is a front view showing a hot water storage type water heater 100 according to the first embodiment. As shown in FIG. 1, the hot water storage type water heater 100 of the present embodiment has a hot water storage tank unit 30 having a built-in hot water storage tank 1 and a heating means 4 capable of heating water to generate hot water. ing. The hot water storage tank unit 30 and the heating means 4 are connected by a water inlet pipe 3 and a hot water outlet pipe 5. The hot water storage tank unit 30 is connected to a water supply pipe 2 for supplying water from a water source such as an external water supply, a bath hot water supply pipe 6, and a hot water supply pipe 7. The water stored in the hot water storage tank 1 is led out from the lower part of the hot water storage tank 1 and is conveyed to the heating means 4 through the water inlet pipe 3. The heating means 4 is composed of, for example, a heat pump unit that heats water using a refrigeration cycle. The water conveyed to the heating means 4 is heated to become hot water. This high-temperature hot water returns to the hot water storage tank unit 30 through the hot water outlet pipe 5, flows into the hot water storage tank 1 from the upper part of the hot water storage tank 1, and is stored. Inside the hot water storage tank unit 30, a mixing valve for mixing the hot water taken out from the hot water storage tank 1 and the water supplied from the water supply pipe 2 to control the temperature is provided. The hot water whose temperature is controlled by the mixing valve is supplied to the bathtub 40 of the bathroom via the bath hot water supply pipe 6, or is supplied to the hot water supply terminal such as a shower, kitchen, or washroom faucet via the hot water supply pipe 7. Will be done. The heating means in the present disclosure is not limited to the above-described configuration, and for example, a heating means such as an electric heater may be arranged in the hot water storage tank 1.

The hot water storage tank unit 30 includes a box-shaped outer case 10 having a rectangular parallelepiped outer shape. The hot water storage tank 1 is housed in the outer case 10 in a state of being covered with a heat insulating material described later for suppressing heat dissipation. A plurality of tank unit legs 12 are installed below the outer case 10. The hot water storage tank unit 30 is supported and fixed to the ground or a pedestal by these tank unit legs 12.

FIG. 1 shows a state in which the front plate of the outer case 10 is removed. By performing as shown in FIG. 1, it is possible to perform maintenance of equipment such as pipes, pumps, valves, reheating heat exchangers, and control boards arranged in the hot water storage tank unit 30.

Inside the hot water storage tank 1, a temperature stratification can be formed in which the upper side is high temperature and the lower side is low temperature due to the difference in the specific gravity of water due to the difference in temperature. When the hot water storage type water heater 100 is used, a temperature distribution of, for example, a high temperature water layer above, a low temperature water layer below, and a medium hot water layer between them is formed inside the hot water storage tank 1.

FIG. 2 is a perspective view of a hot water storage tank 1 included in the hot water storage type water heater 100 according to the first embodiment. As shown in FIG. 2, the hot water storage tank 1 has a cylindrical shape. The hot water storage tank 1 is made of a metal material such as stainless steel. When the hot water storage tank unit 30 is installed at the installation location, the cylindrical axial direction of the hot water storage tank 1 is substantially parallel to the vertical line. The hot water storage tank 1 includes a body portion 1a having a constant diameter along the cylindrical axis direction, an upper portion 1b provided above the body portion 1a, and a lower portion 1c provided below the body portion 1a. Each of the upper part 1b and the lower part 1c is formed by, for example, a hemispherical or bowl-shaped end plate.

A medium temperature water port 17 is provided in the body 1a of the hot water storage tank 1. A pipe through which medium-temperature water passes (not shown) is connected to the medium-temperature water port 17. The medium-temperature water flows into the hot water storage tank 1 from the medium-temperature water port 17, and the medium-temperature water in the hot-water storage tank 1 flows out from the medium-temperature water port 17. In the illustrated example, two medium temperature water outlets 17 are provided. The two medium-temperature water ports 17 are located at different positions with respect to the cylindrical axial direction of the hot water storage tank 1, and are at the same position with respect to the circumferential direction of the hot water storage tank 1. The number of medium-temperature water ports 17 included in the hot water storage tank 1 is not limited to this example, and may be only one, for example.

A high temperature water port 18 is provided in the upper portion 1b of the hot water storage tank 1. In the illustrated example, two high-temperature water ports 18 are provided, one high-temperature water port 18 is connected to the hot water outlet pipe 5, and the other high-temperature water port 18 is connected to the hot water supply pipe 7. The high-temperature water passing through the hot water outlet pipe 5 flows into the hot water storage tank 1 from one of the high-temperature water outlets 18. The high-temperature water in the hot water storage tank 1 flows out from the other high-temperature water port 18 to the hot water supply pipe 7. The number of hot water outlets 18 included in the hot water storage tank 1 is not limited to this example, and may be only one, for example.

Although not shown, the water supply pipe 2 and the water inlet pipe 3 are connected to the low temperature water port provided in the lower portion 1c of the hot water storage tank 1. The low-temperature water passing through the water supply pipe 2 flows into the hot water storage tank 1 from the low-temperature water port. The low-temperature water in the hot water storage tank 1 flows out from the low-temperature water port to the water inlet pipe 3. Further, on the surface of the hot water storage tank 1, a plurality of hot water storage temperature sensors (not shown) are installed at positions having different heights from each other. By detecting the water temperature distribution along the vertical direction in the hot water storage tank 1 with these hot water storage temperature sensors, the amount of residual hot water and the amount of heat storage in the hot water storage tank 1 can be detected. When the amount of remaining hot water or the amount of heat stored becomes small, a hot water storage operation of storing hot water in the hot water storage tank 1 is executed by using the heating means 4.

FIG. 3 is an exploded perspective view of the hot water storage tank 1 and the heat insulating material covering the hot water storage tank 1. FIG. 4 is a perspective view showing a state in which the hot water storage tank 1 is covered with a heat insulating material. As shown in FIG. 3, the hot water storage type water heater 100 of the present embodiment has a vacuum heat insulating material 11, an upper heat insulating material 13, a front heat insulating material 14, and a back heat insulating material 15 as heat insulating materials for covering the hot water storage tank 1. And the lower heat insulating material 16. The vacuum heat insulating material 11 covers the body portion 1a of the hot water storage tank 1. In the illustrated example, two vacuum heat insulating materials 11 are provided, one vacuum heat insulating material 11 covers the left half circumference of the outer circumference of the body portion 1a, and the other vacuum heat insulating material 11 covers the body portion 1a. Cover the right half of the outer circumference.

The upper heat insulating material 13 covers the upper portion 1b of the hot water storage tank 1. The front heat insulating material 14 and the back heat insulating material 15 cover the body portion 1a of the hot water storage tank 1 from above the vacuum heat insulating material 11. The front heat insulating material 14 covers a half circumference on the front side of the outer circumference of the body portion 1a. The back heat insulating material 15 covers a half circumference on the back side of the outer circumference of the body portion 1a. The lower heat insulating material 16 covers the lower part 1c of the hot water storage tank 1. Each of the upper heat insulating material 13, the front heat insulating material 14, the back heat insulating material 15, and the lower heat insulating material 16 is made by molding foamed plastic.

As shown in FIGS. 3 and 4, each of the upper heat insulating material 13, the front heat insulating material 14, the back heat insulating material 15, and the lower heat insulating material 16 has a complicated shape. There are two main reasons for this. One reason is to avoid the piping connected to each part of the hot water storage tank 1. Another reason is to support equipment such as heat exchangers or circulation pumps. For these reasons, each heat insulating material is provided with an avoidance hole for passing a pipe, a convex portion for supporting the device, and the like.

In the hot water storage type water heater 100, it is important to reduce the amount of heat dissipated from the hot water stored in the hot water storage tank 1 in order to improve the energy saving performance. Therefore, the heat insulating performance of the heat insulating material covering the hot water storage tank 1 is important. As a material for a heat insulating material that is widely used in general, there is expanded polystyrene (hereinafter referred to as EPS). Further, the urethane foam heat insulating material having a lower thermal conductivity than EPS is excellent in heat insulating performance. Generally, the thermal conductivity of EPS is about 33 mW / (m · K) to 38 mW / (m · K), and the thermal conductivity of urethane foam heat insulating material is 20 mW / (m · K) to 24 mW /. It is about (m · K). Therefore, the urethane foam heat insulating material has about 1.5 to 2 times the heat insulating performance as compared with the EPS of the same thickness.

The vacuum heat insulating material 11 is, for example, a core material made of glass wool placed in a bag made of a laminated film having a gas barrier property, and the inside is put into a vacuum state (hereinafter, referred to as "vacuum state") close to vacuum. .. The vacuum heat insulating material 11 can achieve high heat insulating performance by eliminating the air in the bag as much as possible and creating a vacuum state. The thermal conductivity of the vacuum heat insulating material 11 is, for example, about 1.8 mW / (m · K) to 2.8 mW / (m · K). Such a vacuum heat insulating material 11 has 15 to 20 times the heat insulating performance as compared with EPS of the same thickness. On the other hand, the vacuum heat insulating material 11 is vulnerable to impact, and when the vacuum state is released by making a hole in the bag, its thermal conductivity is about 30 mW / (m · K) to 40 mW / (m · K). It will rise.

As described above, the urethane foam heat insulating material is superior to the EPS in terms of heat insulating performance, but the EPS is superior to the urethane foam heat insulating material in terms of moldability. EPS softens the resin by applying steam to the styrene raw material beads, and at the same time, expands the gas contained in the beads to pre-foam them, and then fuses the beads filled in the mold to each other. Mold with. In EPS molding, beads are distributed to the details of the mold, so that a thin portion is unlikely to occur. On the other hand, in the urethane foam heat insulating material, two stock solutions containing each of the raw materials polyol and isocyanate as main components are mixed by a foaming machine, and then injected in a liquid state into the filling space for foaming and curing. In the molding of such a urethane foam heat insulating material, since the raw material is a highly viscous liquid, if the shape of the molded product is complicated, it may not be possible to correspond to the detailed shape and a missing portion may occur.

In the present embodiment, the front heat insulating material 14 is a urethane foam heat insulating material. By using the urethane foam heat insulating material for the front heat insulating material 14, the heat insulating performance is improved as compared with the case where the front heat insulating material 14 is made of EPS. As shown in FIG. 4, the front heat insulating material 14 has an avoidance hole 19 for passing a pipe connected to the medium temperature water port 17. In the present embodiment, two avoidance holes 19 are formed in the front heat insulating material 14 corresponding to the two medium temperature water outlets 17.

FIG. 5 is a perspective view of the front heat insulating material 14. FIG. 6 is a front view of the front heat insulating material 14. FIG. 7 is a cross-sectional view of the front heat insulating material 14. The cross section of FIG. 7 is a cross section cut by a plane passing through the cylindrical shaft of the hot water storage tank 1 and the avoidance hole 19. As shown in these figures, the front heat insulating material 14 has an inner wall surface 14a facing the surface of the hot water storage tank 1 and an outer wall surface 14b facing the side opposite to the inner wall surface 14a. The avoidance hole 19 penetrates from the inner wall surface 14a to the outer wall surface 14b. As shown in FIG. 7, the avoidance hole 19 has an outer opening 19b that opens to the outer wall surface 14b and an inner opening 19a that opens to the inner wall surface 14a. As shown in FIG. 6, the shape of the outer opening 19b is elliptical. Here, the "elliptical shape" in the present disclosure is not limited to the shape of an ellipse that is mathematically defined as one of the conic sections. The term "oval" in the present disclosure broadly includes a rounded shape having a longitudinal direction, and for example, both ends of a semicircle and both ends of another semicircle are connected via two line segments. It may be shaped like this, or it may be shaped like a vertical cross section of a rugby ball.

In the present embodiment, the following effects can be obtained by making the outer opening 19b of the avoidance hole 19 oval. When the work of connecting the pipe to the medium temperature water port 17 after attaching the front heat insulating material 14 to the hot water storage tank 1, a margin is created in the space inside the avoidance hole 19, so that the work is easy and the medium temperature water port 17 It is possible to reliably prevent the fastener (not shown) for fixing the pipe from coming into contact with the front heat insulating material 14. From these things, workability is improved.

The heat insulating material manufacturing method according to the present embodiment is a method of molding the front heat insulating material 14 by injecting a urethane raw material into a heat insulating material molding mold, foaming and curing the urethane raw material. FIG. 8 is a diagram showing a part of the lower mold 21 of the heat insulating material molding mold according to the present embodiment. As shown in FIG. 8, the lower mold 21 has a mold inner surface 21a and a mold convex portion 22 protruding from the mold inner surface 21a. The upper view in FIG. 8 is a cross-sectional view cut along a plane perpendicular to the inner surface 21a of the mold, and the lower figure in FIG. 8 is a convex portion 22 of the mold from a direction perpendicular to the inner surface 21a of the mold. It is the figure which saw. The inner surface 21a of the mold is a surface for forming the outer wall surface 14b of the front heat insulating material 14. The mold convex portion 22 is a convex portion for forming the avoidance hole 19. At the time of molding, the upper mold (not shown) overlaps the lower mold 21, and the upper mold comes into contact with the upper surface of the convex portion 22 of the mold.

The shape of the mold convex portion 22 corresponds to the shape of the avoidance hole 19. The mold convex portion 22 has an elliptical base portion 22a. The base portion 22a is a portion of the mold convex portion 22 that is in contact with the mold inner surface 21a. The outer opening 19b is formed by the base 22a. The oval shape of the base 22a corresponds to the oval shape of the outer opening 19b. The mold convex portion 22 has an elliptical cross-sectional shape perpendicular to the protruding direction thereof. In FIG. 8, the flow direction of the urethane raw material during molding is indicated by an arrow. As described above, in the heat insulating material manufacturing method of the present embodiment, the urethane raw material is injected near the mold convex portion 22 so that the urethane raw material flows along the longitudinal direction of the ellipse of the mold convex portion 22. .. As a result, the urethane raw material easily wraps around to the back side of the convex portion 22 of the mold, so that the occurrence of a missing portion can be reliably prevented.

The front heat insulating material 14 has a shape in which the cylindrical axial direction of the hot water storage tank 1 is the longitudinal direction. At the time of molding, the urethane raw material flows along the longitudinal direction of the front heat insulating material 14. As shown in FIG. 6, the longitudinal direction of the outer opening 19b in the present embodiment is parallel to the cylindrical axial direction of the hot water storage tank 1. Therefore, since the urethane raw material flows along the longitudinal direction of the ellipse of the convex portion 22 of the mold, it is possible to reliably prevent the occurrence of the missing portion.

As shown in FIG. 8, the mold convex portion 22 in the present embodiment has a top portion 22b for forming the inner opening 19a. As shown in FIG. 6, the shape of the inner opening 19a in the present embodiment is circular. Therefore, the shape of the top 22b is circular. In the present embodiment, the circular shape of the top 22b makes it easier for the urethane raw material to wrap around the top 22b. Therefore, it is more advantageous in preventing the occurrence of a missing portion. The shape of the inner opening 19a and the top 22b may be elliptical. Even in that case, the same effect can be obtained.

As shown in FIGS. 6 and 7, the area of the outer opening 19b in the present embodiment is larger than the area of the inner opening 19a. As a result, the following effects can be obtained. Since the area of the outer opening 19b is large, the space inside the avoidance hole 19 becomes wider, which is more advantageous in improving workability when connecting the pipe to the medium temperature water port 17. Further, since the area of the inner opening 19a is small, it is more advantageous in suppressing the heat of the hot water storage tank 1 from leaking from the avoidance hole 19.

As shown in FIG. 8, the shape of the mold convex portion 22 in the present embodiment exhibits a frustum shape in which the cross-sectional area perpendicular to the protruding direction gradually decreases as the distance from the inner surface 21a of the mold increases. As a result, the following effects can be obtained. Since the angle between the side surface 22c of the mold convex portion 22 and the mold inner surface 21a is an obtuse angle, the urethane raw material is more likely to wrap around the mold convex portion 22. Therefore, it is more advantageous in preventing the occurrence of a missing portion. Since the shape of the convex portion 22 of the mold has a frustum shape, the shape of the internal space of the avoidance hole 19 also has a frustum shape as shown in FIG.

In particular, in the example shown in FIG. 8, the side surface 22c of the mold convex portion 22 is formed by a line segment connecting a point in the space above the mold convex portion 22 and each point on the outer circumference of the elliptical base portion 22a. It has a shape along an elliptical thruster. This makes it easier for the urethane raw material to wrap around the convex portion 22 of the mold. Therefore, it is more advantageous in preventing the occurrence of a missing portion. The shape of the internal space of the avoidance hole 19 is an elliptical frustum.

Instead of the example shown in FIG. 8, the shape of the convex portion 22 of the mold exhibits an elliptical columnar shape having an elliptical cross section having a long axis in the direction along the flow direction of the urethane raw material in a cross section perpendicular to the protruding direction thereof. It may be one. Even in that case, since the urethane raw material easily wraps around the convex portion 22 of the mold, it is more advantageous in preventing the occurrence of the missing portion.

In the present embodiment, the back surface heat insulating material 15 is preferably a urethane foam heat insulating material. By using the urethane foam heat insulating material for the back heat insulating material 15, the heat insulating performance is improved as compared with the case where the back heat insulating material 15 is EPS. When the back heat insulating material 15 is a urethane foam heat insulating material, the front heat insulating material 14 corresponds to the first urethane foam heat insulating material, and the back heat insulating material 15 is a second urethane foam heat insulating material arranged adjacent to the front heat insulating material 14. Corresponds to the material.

As shown in FIGS. 3 and 5, the front heat insulating material 14 has a curved first notch 20 formed in a part of an edge 14c in contact with the back heat insulating material 15. The back heat insulating material 15 has a curved second notch 23 formed in a part of the edge 15a in contact with the front heat insulating material 14. In the illustrated example, each of the first notch portion 20 and the second notch portion 23 has an arc-shaped edge portion having a central angle of 180 degrees. As shown in FIG. 4, when the front heat insulating material 14 and the back heat insulating material 15 are attached to the hot water storage tank 1 and the edge 14c comes into contact with the edge 15a, the first notch portion 20 and the second notch portion 23 are combined. A circular opening is formed. A part of the vacuum heat insulating material 11 can be visually recognized from this opening. When the vacuum state is released by making a hole in the bag of the vacuum heat insulating material 11 and allowing air to enter, the vacuum heat insulating material 11 is inflated with air. Therefore, if a part of the vacuum heat insulating material 11 is visually confirmed from the opening to see if it is inflated, it is checked whether or not there is a hole in the bag of the vacuum heat insulating material 11, that is, the heat insulating performance of the vacuum heat insulating material 11. Can be checked to see if it has decreased. In the present embodiment, it is possible to easily check whether or not the heat insulating performance of the vacuum heat insulating material 11 is deteriorated without removing the front heat insulating material 14 and the back heat insulating material 15. In the present embodiment, since a part of the vacuum heat insulating material 11 can be visually recognized from the opening formed by the combination of the first notch portion 20 and the second notch portion 23, the visible range becomes large and the vacuum is formed. It is easy to inspect the heat insulating material 11.

Instead of the illustrated example, the back heat insulating material 15 is not provided with the second notch 23, and a part of the vacuum heat insulating material 11 can be visually recognized only from the first notch 20 of the front heat insulating material 14. You may do so. Alternatively, the front heat insulating material 14 may not be provided with the first cutout portion 20, and a part of the vacuum heat insulating material 11 may be made visible only from the second cutout portion 23 of the back heat insulating material 15.

When the independent holes are provided in the front heat insulating material 14, the raw materials merge during the molding of the front heat insulating material 14, so that a weld line may occur. On the other hand, in the molding of the first notch portion 20, the raw materials do not merge, so that the occurrence of weld lines can be prevented. In particular, since the first completely notched portion 20 has a curved shape, the convex portion of the mold for forming the first completely notched portion 20 also has a curved shape, so that the resistance to the flow of the urethane raw material is reduced, and the missing portion has a curved shape. The occurrence can be prevented more reliably. The same effect as described above can be obtained with respect to the second notch portion 23 of the back heat insulating material 15.

At least one of the upper heat insulating material 13 and the lower heat insulating material 16 may be a urethane foam heat insulating material. In the present embodiment, an example in which the avoidance hole 19 through which the pipe is passed is formed in the front heat insulating material 14 has been described, but the present invention is used in at least one of the upper heat insulating material 13, the back heat insulating material 15, and the lower heat insulating material 16. The avoidance hole 19 may be formed in the same manner as in the embodiment.

1 hot water storage tank, 1 hot water storage tank, 1a body, 1b upper part, 1c lower part, 2 water supply pipe, 3 water inlet pipe, 4 heating means, 5 hot water outlet pipe, 6 bath hot water supply pipe, 7 hot water supply pipe, 10 outer case, 11 vacuum heat insulation Material, 12 tank unit legs, 13 upper heat insulating material, 14 front heat insulating material, 14a inner wall surface, 14b outer wall surface, 14c edge, 15 back heat insulating material, 15a edge, 16 lower heat insulating material, 17 medium hot water outlet, 18 high temperature water outlet, 19 Avoid hole, 19a inner opening, 19b outer opening, 20 first notch, 21 lower mold, 21a inner surface of mold, 22 convex part of mold, 22a base, 22b top, 22c side surface, 23 second notch, 30 hot water storage tank unit, 40 bathtub, 100 hot water storage type water heater

Claims (9)

Cylindrical hot water storage tank and
An outer case for storing the hot water storage tank and
The piping connected to the hot water storage tank and
A urethane foam heat insulating material that covers the hot water storage tank in the outer case,
With
The urethane foam heat insulating material has an inner wall surface facing the hot water storage tank, an outer wall surface facing the side opposite to the inner wall surface, and an avoidance hole for penetrating from the inner wall surface to the outer wall surface and passing the piping. Have and
The avoidance hole has an outer opening that opens to the outer wall surface and an inner opening that opens to the inner wall surface.
A hot water storage type water heater whose outer opening has an oval shape. The hot water storage type water heater according to claim 1, wherein the longitudinal direction of the outer opening is parallel to the cylindrical axial direction of the hot water storage tank. The hot water storage type water heater according to claim 1 or 2, wherein the shape of the inner opening is circular or elliptical. The hot water storage type water heater according to any one of claims 1 to 3, wherein the area of the outer opening is larger than the area of the inner opening. The hot water storage type water heater according to any one of claims 1 to 4, wherein the avoidance hole has a frustum-shaped internal space. Further provided with a vacuum heat insulating material arranged between the hot water storage tank and the urethane foam heat insulating material,
The urethane foam heat insulating material further has an edge and a curved notch formed in a part of the edge.
The hot water storage type water heater according to any one of claims 1 to 5, wherein a part of the vacuum heat insulating material can be visually recognized from the notch. The urethane foam heat insulating material is the first urethane foam heat insulating material.
A second urethane foam heat insulating material arranged adjacent to the first urethane foam heat insulating material and covering the hot water storage tank in the outer case, and a second urethane foam heat insulating material.
A vacuum heat insulating material arranged between the hot water storage tank, the first urethane foam heat insulating material, and the second urethane foam heat insulating material,
With more
The first urethane foam heat insulating material has a first notch formed in a part of an edge in contact with the second urethane foam heat insulating material.
The second urethane foam heat insulating material has a second notch formed in a part of an edge in contact with the first urethane foam heat insulating material.
The invention according to any one of claims 1 to 5, wherein a part of the vacuum heat insulating material can be visually recognized from the opening formed by the combination of the first notch and the second notch. Hot water storage type water heater. A heat insulating material molding mold that molds urethane foam heat insulating material that covers a cylindrical hot water storage tank.
The convex portion of the mold for forming the avoidance hole penetrating from the inner wall surface to the outer wall surface of the urethane foam heat insulating material protrudes from the inner surface of the mold of the heat insulating material molding mold.
The shape of the convex portion of the mold has a cone shape in which the cross-sectional area perpendicular to the protruding direction gradually decreases as the distance from the inner surface of the mold increases, or the flow of the urethane raw material in the cross section perpendicular to the protruding direction. A heat insulating material molding die having an elliptical columnar cross section having an elliptical cross section with a long axis along the direction. It is a heat insulating material manufacturing method in which a urethane foam heat insulating material covering a cylindrical hot water storage tank is molded by a heat insulating material molding mold.
The convex portion of the mold for forming the avoidance hole penetrating from the inner wall surface to the outer wall surface of the urethane foam heat insulating material protrudes from the inner surface of the mold of the heat insulating material molding mold.
The convex portion of the mold has an elliptical cross-sectional shape perpendicular to the projecting direction.
A method for producing a heat insulating material, in which the urethane raw material is injected so that the urethane raw material flows along the longitudinal direction of the ellipse near the convex portion of the mold.

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