Resin casting mold and method for manufacturing a hot water storage tank unit
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- MITSUBISHI ELECTRIC CORP
- Filing Date
- 2020-06-25
- Publication Date
- 2026-07-09
AI Technical Summary
Conventional methods for manufacturing heat-insulating components for hot water storage tanks using resin molding dies face issues with gas entrapment in the cavity, leading to incomplete distribution of resin material and insufficient moldability.
The resin molding die is designed with a lower die having a recess and an upper die with a protrusion, featuring vents that connect the cavity's highest portion to the exterior, ensuring even distribution of resin material and improved moldability by allowing gas escape.
This design enhances the moldability of heat-insulating components, preventing gas accumulation and ensuring complete resin distribution, resulting in improved formability and thermal insulation performance of the hot water storage tank unit.
Abstract
Description
Technical field
[0001] The present disclosure relates to a resin mold, a method for manufacturing a hot water storage tank unit using the resin mold, and a hot water storage tank unit. Technological background
[0002] Traditionally, a heat-insulating component for a hot water storage tank unit of a hot water storage tank type is formed by dividing it into several parts, each shaped to match the outer form of the hot water storage tank, and then attaching them to the circumference of the hot water storage tank. The heat-insulating component is made of a heat-insulating foam material, such as rigid polyurethane foam or styrene foam, and is foamed using a resin mold consisting of an upper and a lower die (see, for example, PTL1). Citation reads patent literature
[0003] [PTL1] JP 2008-107015 A Brief description: Technical task
[0004] However, the conventional method for manufacturing the heat-insulating component using the resin mold presents the problem that during the foaming of the heat-insulating component, gas is trapped in the upper part of the cavity of the resin mold, and the resin material is not distributed throughout the entire cavity, leading to insufficient formability.
[0005] The purpose of the present disclosure is to provide a resin mold and a hot water storage tank unit in which a resin material is distributed throughout the entire cavity of the resin mold and the formability of the heat-insulating component is improved.
[0006] A resin mold according to the present disclosure is used for foaming a heat-insulating component. The resin mold comprises: a lower mold with a recess and a first outer edge as the outer edge of the recess; and an upper mold with a protrusion fitting into the recess and a second outer edge as the outer edge of the protrusion. When the lower mold is closed with the upper mold, the protrusion is received into the recess to form a cavity, and several vents, namely points where the first outer edge and the second outer edge face each other via gaps, connect the uppermost section of the cavity and the exterior of the resin mold.
[0007] A hot water storage tank unit according to the present disclosure comprises: a hot water storage tank for storing water; and a foamed thermally insulating component covering one circumference of the hot water storage tank. The foamed thermally insulating component comprises several partitioned thermally insulating components and has several ridges formed on a side opposite the hot water storage tank along a dividing surface between the partitioned thermally insulating components. Advantageous effects of the invention
[0008] The resin mold according to the present disclosure has the effect of improving the formability of the heat-insulating component during foaming.
[0009] The hot water storage tank unit according to the present disclosure has the effect that the thermal insulation performance of the entire hot water storage tank unit can be improved by improving the formability of the thermally insulating component. List of characters Fig. Figure 1 is a perspective view showing a hot water storage tank type water heater with a hot water storage tank unit according to a first embodiment. Fig. Figure 2 is a circuit diagram of the hot water storage tank unit of the hot water storage type. Fig. Figure 3 is a perspective view showing a hot water storage tank unit according to the first embodiment. Fig. Figure 4 is a cross-sectional view showing the hot water storage tank unit according to the first embodiment. Fig. Figure 5 is a perspective view showing a foamed heat-insulating component of the hot water storage tank unit according to the first embodiment. Fig. Figure 6 is a cross-sectional view showing the foamed heat-insulating component of the hot water storage tank unit according to the first embodiment. Fig. Figure 7 is a perspective view showing a resin mold for forming a heat-insulating component for the front part according to the first embodiment. Fig. Figure 8 is a top view showing the resin mold for forming a heat-insulating component for the front part according to the first embodiment. Fig. Figure 9 is a perspective view to illustrate a manufacturing process for the hot water storage tank unit according to the first embodiment. Fig. Figure 10 is a cross-sectional view to illustrate the manufacturing process for the hot water storage tank unit using the resin mold for forming the heat-insulating component for the front part according to the first embodiment. Fig. Figure 11 is a schematic view showing the heat-insulating component for the front part formed by means of the resin casting mold according to the first embodiment. Fig. Figure 12 is a top view showing a resin mold for forming an upper heat-insulating component according to the first embodiment. Fig. Figure 13 is a cross-sectional view to illustrate a manufacturing process for the hot water storage tank unit using the resin mold for forming the upper heat-insulating component according to the first embodiment. Fig. Figure 14 is a schematic view showing the upper heat-insulating component formed by means of the resin casting mold according to the first embodiment. Fig. Figure 15 is a perspective view to illustrate modifications of the heat-insulating components of the hot water storage tank unit according to the first embodiment. Fig. Figure 16 is a top view showing a modification of the resin mold for forming the heat-insulating component for the front part according to the first embodiment. Fig. Figure 17 is a top view showing a first modification of the resin casting mold for forming the upper heat-insulating component according to the first embodiment. Fig. Figure 18 is a top view showing a second modification of the resin mold for forming the upper heat-insulating component according to the first embodiment. Fig. Figure 19 is a perspective view showing a resin mold for forming a heat-insulating component for the front part according to a second embodiment. Fig. Figure 20 is a top view showing the resin mold for forming a heat-insulating component for the front part according to a second embodiment. Fig. Figure 21 is a cross-sectional view to illustrate a manufacturing process of the hot water storage unit using the resin casting mold for forming the heat-insulating component for the front part according to a second embodiment. Fig. Figure 22 is a perspective view showing a resin mold for forming a heat-insulating component for the front part according to a third embodiment. Fig. Figure 23 is a top view showing the resin mold for forming the heat-insulating component for the front part according to the third embodiment. Fig. Figure 24 is a cross-sectional view to illustrate the manufacturing process of the hot water storage unit using the resin mold for forming the heat-insulating component for the front part according to the third embodiment. Description of embodiments
[0010] The following descriptions illustrate embodiments with reference to the drawings. In subsequent drawings, the same or corresponding parts are designated by the same reference numerals, and their descriptions are not repeated. In the following description, the term "water" generally means liquid water and can include water ranging from low temperature to high temperature hot water. First embodiment
[0011] A resin mold, a manufacturing process for a hot water storage unit using the resin mold, and a hot water storage unit according to a first embodiment are described with reference to the Fig. 1 to Fig. 11 described.
[0012] First, the overall configuration of the water heater equipped with the hot water storage unit according to the first embodiment is described with reference to the Fig. 1 and Fig. 2 described. Fig. Figure 1 is a perspective view showing a hot water heater 1000 of the hot water storage type with a hot water storage tank unit 100 according to a first embodiment, and Fig. Figure 2 is a circuit diagram of the 1000 hot water heater of the hot water storage type.
[0013] As in Fig. 1 and Fig. As shown in Figure 2, the hot water storage tank 1000 comprises a heat pump unit 110, which serves as a heater for heating water, and the hot water storage tank unit 100 for storing and distributing the water heated by the heat pump unit 110. The heat pump unit 110 and the hot water storage tank unit 100 are connected to each other by a heat pump supply line 21, a heat pump return line 22, and electrical wiring (not shown). Fig. Figure 1 does not show the heat pump supply line 21 and the heat pump return line 22.
[0014] As in Fig. As shown in Figure 2, the hot water storage tank unit 100 includes a hot water storage tank 10 for storing water, a pressure reducing valve 23, a drain valve 24, a mixing valve 25, a switching valve 26, and a check valve 27, as functional valves of the hot water storage tank 1000 for performing various functions such as boiling, hot water supply, and hot water filling. A cold water line 28, to which water is supplied from a water source such as the waterworks, is connected to a lower section of the hot water storage tank 10.
[0015] The water stored in the lower section of the hot water storage tank 10 is supplied to the heat pump unit 110 via the heat pump supply line 21 by a heat source pump 29. The water, heated to a high temperature by the heat pump unit 110 using atmospheric heat, is then returned to the upper section of the hot water storage tank 10 via the heat pump return line 22 and stored there.
[0016] The temperature in the hot water storage tank 10 rises from the lower to the upper section, so that water with a temperature distribution of low, medium, and high temperatures accumulates and is stored in the hot water storage tank 10 from the lower to the upper section. Several temperature sensors 30 for measuring the temperature of the water in the hot water storage tank 10 are provided vertically on the outer surface of the hot water storage tank 10. A thermistor, for example, is used as a temperature sensor 30.
[0017] The heat pump 110 is a heating medium for heating the low-temperature water coming from the hot water storage tank 10 to a high temperature. The heat pump unit 110 includes: a compressor for compressing a refrigerant, such as carbon dioxide (CO2), to a high temperature and high pressure; a condenser for condensing the refrigerant discharged by the compressor and exchanging heat with the low-temperature water coming from the hot water storage tank 10 to heat the water using the heat of condensation; a pressure reducing valve for reducing the pressure of the refrigerant from the condenser; and an evaporator for absorbing heat from the atmosphere and evaporating the depressurized refrigerant. Note that the internal configuration of the heat pump unit 110 is not shown.
[0018] Water heated by the heat pump unit 110 and stored in the hot water storage tank 10 is drawn from the upper section of the hot water storage tank 10, routed through the hot water line 31 to the mixing valve 25, and mixed by the mixing valve 25 with water from a branched water supply line 32, which branches off from the cold water line 28, to the desired temperature. The mixed water is then discharged from a hot water connection 34 through a hot water supply line, such as a faucet or shower, and thus used.
[0019] Next, the hot water storage tank unit 100 will be described with reference to the Fig. 3 to Fig. 6 described. Fig. Figure 3 is a perspective view showing the hot water storage tank unit 100, and Fig. Figure 4 is a cross-sectional view showing the hot water storage tank unit 100. Fig. 3 is part of an outer casing 50 of which is in Fig. The hot water storage tank unit 100 shown in the diagram has been omitted, and mainly the interior of the outer casing 50 is shown. Fig. Figure 5 is a perspective view to illustrate a foamed heat-insulating component 40 of the hot water storage tank unit 100, and Fig. Figure 6 is a cross-sectional view along line AA in Fig. 5.
[0020] In addition to the reference to Fig. 2 described configuration of the hot water storage tank 10 (in Fig. (3 not shown) the hot water storage tank unit 100 further includes a foamed heat-insulating component 40, which is provided in such a way that it supports the hot water storage tank 10, the outer casing 50 for receiving the foamed heat-insulating component 40, and feet 60 provided under the outer casing 50.
[0021] The outer casing 50 houses the hot water storage tank 10 and the foamed heat-insulating component 40, and serves for design purposes as a device, protection of the hot water storage tank 10, thermal insulation, and the like. The outer casing 50 is made, for example, of a thin sheet of steel or a resin with weather resistance and flame resistance.
[0022] As in Fig. As shown in Figure 1, the outer casing 50 is formed in the form of a box extending vertically in the height direction of the hot water storage unit 100, the outer casing 50 comprising: a front plate 51 arranged in front of the hot water storage tank 10, which can be opened and closed for maintenance and the like; a riser plate 52 for connecting external piping provided outside the hot water storage tank unit 100 for the supply of water, the supply of hot water, and the inlet and return to and from the heat pump and a bathtub; two side plates 53, 54 arranged on the sides of the hot water storage tank 10; a rear plate 55 arranged behind the hot water storage tank 10; a cover plate 56 arranged above the hot water storage tank 10; and a bottom plate 57 arranged below the hot water storage tank 10.The front plate 51, the riser plate 52, the side plates 53, 54, the rear plate 55, the top plate 56 and the bottom plate 57 are connected to each other at the required places by fitting, riveting or the like to the outer housing 50.
[0023] The feet 60 are provided in the outer housing 50 such that an inner foot, provided under the hot water storage tank 10, and an outer foot, attached under the base plate 57 of the outer housing 50, are secured to hold the hot water storage tank 10. In the present embodiment, as shown in Fig. 3 shown, an example with three feet 60 shown.
[0024] As in Fig. As shown in Figure 4, the hot water storage tank 10 is formed by welding together three components: a main plate 11 shaped cylindrically using a material such as stainless steel; an upper curved plate 12 with a curved shape and a bowl-like curvature that covers the upper opening of the main plate 11; and a lower curved plate 13 with a curved shape and a bowl-like curvature that covers the upper opening of the main plate 11. The upper curved plate 12 and the lower curved plate 13 of the hot water storage tank 10 are provided with connections 12a and 13a for connecting the cold water line 28 and the hot water line 31, respectively.
[0025] As in the Fig. 4 and Fig. As shown in Figure 5, the foamed heat-insulating component 40 covers the circumference of the hot water storage tank 10 and is formed from four separate heat-insulating components, which are an upper heat-insulating component 41, a heat-insulating component 42 for the front part, a heat-insulating component 43 for the rear part and a lower heat-insulating component 44.
[0026] The upper heat-insulating component 41 and the lower heat-insulating component 44 are each positioned to cover the upper curved plate 12 and the lower curved plate 13 of the hot water storage tank 10, respectively, with the bowl-like curvature, and the inner surface of each of the upper heat-insulating component 41 and the lower heat-insulating component 44 has a bowl-like shape and is curved. As shown in Fig. As shown in Figure 4, the upper heat-insulating component 41 and the lower heat-insulating component 44 can each have a structure in which part of the hot water storage tank 10 is exposed, and the piping can be connected to each of the connections 12a, 13a.
[0027] As in Fig. 6 in a cross-sectional view along line AA of Fig. As shown in Figure 5, the heat-insulating component 42 for the front part and the heat-insulating component 43 for the rear part are formed such that the main plate 11, which has a cylindrical shape (i.e., a circular shape in cross-sectional view), is covered by the heat-insulating component 42 for the front part and the heat-insulating component 43 for the rear part. Line BB indicates the dividing point of the two divided heat-insulating components. The heat-insulating component 42 for the front part is designed to cover the front of the hot water storage tank 10, and the heat-insulating component 43 for the rear part is designed to cover the rear of the hot water storage tank 10. Note that the front and rear of the hot water storage tank 10 are not limited to the directions described in the present embodiment.
[0028] In the upper thermally insulating component 41, the thermally insulating component 42 for the front part, the thermally insulating component 43 for the rear part, and the lower thermally insulating component 44, several burrs are formed on at least one of the divided thermally insulating components that are in contact with each other at a dividing surface, i.e., a contact surface with another divided thermally insulating component. The dividing surface is, for example, the surface at the point defined by line BB in Fig. 6 specified division point, and in Fig. In Figure 6, the heat-insulating component 42 for the front part is in contact with the heat-insulating component 43 for the rear part at the surface indicated by line BB. Note that the details of the ridges will be described later when a method for manufacturing the foamed heat-insulating components 40 is described.
[0029] Each of the four divided heat-insulating components, i.e., the upper heat-insulating component 41, the heat-insulating component 42 for the front part, the heat-insulating component 43 for the rear part and the lower heat-insulating component 44, is preferably formed with a thickness of 1 mm or more and 400 mm or less, in view of the ease of attachment to the outer surface of the hot water storage tank 10.
[0030] Various necessary components are attached externally to each of the upper thermally insulating component 41, the thermally insulating component 42 for the front part, the thermally insulating component 43 for the rear part, and the lower thermally insulating component 44, and consequently each component has a feature as shown in Fig. Figure 5 shows an uneven surface. Note that a split thermal insulation component without an uneven surface can be used.
[0031] In the case of foamed thermal insulation components 40, the upper thermal insulation component 41, the thermal insulation component 42 for the front part, and the thermal insulation component 43 for the rear part are made of rigid polyurethane foam, and the lower thermal insulation component 44 is made of styrene foam. Because rigid polyurethane foam has low thermal conductivity, particularly excellent thermal insulation can be achieved by using the thermal insulation components 40 made of rigid polyurethane foam. Furthermore, as described above, the lower part of the hot water storage tank 10 is at a low temperature, so the lower thermal insulation component 44 does not need to provide as good thermal insulation as the upper thermal insulation component 41, the thermal insulation component 42 for the front part, and the thermal insulation component 43 for the rear part.Thus, the lower heat-insulating component 44 can be made of styrene foam, which has a higher mechanical strength than rigid polyurethane foam, in order to stably support the hot water storage tank 10.
[0032] In the present embodiment, a case is described in which the foamed heat-insulating component 40 is formed from rigid polyurethane foam and styrene foam, but the present disclosure is not limited thereto, and the foamed heat-insulating component 40 can be formed entirely from rigid polyurethane foam or can be formed from another foamed resin material.
[0033] Now, rigid polyurethane foam will be described. Polyurethane foam has a foam (cell) structure and is classified into flexible polyurethane foam and rigid polyurethane foam. Of these, flexible polyurethane foam has a cell structure with interconnected bubbles (open-cell) and a perforated cell wall. Due to its structure, which allows heat to dissipate easily, it has low thermal insulation and is used for mattresses, car seats, and the like, where elastic properties are required. On the other hand, rigid polyurethane foam has a cell structure with independent bubbles (closed-cell) and a continuous cell wall. It has excellent strength and thermal insulation and is therefore used as a heat-insulating material. Therefore, if polyurethane foam is used as the material for the foamed heat-insulating component 40 in the present embodiment, only rigid polyurethane foam is suitable.
[0034] Next, the resin mold and the process for manufacturing the hot water storage tank unit using the resin mold will be described with reference to the Fig. 7 to Fig. 14 described.
[0035] The configuration of the resin casting mold is described below.
[0036] First, with reference to the Fig. 7 and Fig. 8 a resin casting mold 500 for forming the heat-insulating component 42 for the front part of the heat-insulating component 40, described as a resin component. Fig. Figure 7 is a perspective view showing a resin mold 500 for forming a heat-insulating component 42 for the front part according to the present embodiment, and Fig. Figure 8 is a top view showing the resin casting mold 500.
[0037] As in Fig. Figure 7 shows that the resin mold 500 for forming a heat-insulating component 42 for the front part consists of a lower mold 510 and an upper mold 520, and by closing the lower mold 510 with the upper mold 520 it is possible to form a resin material which fills a cavity formed and limited by the lower mold 510 and the upper mold 520.
[0038] The lower form 510 has a recess 512 encompassed by a first outer edge 511. More precisely, the recess 512 is a region projecting back from the first outer edge 511 of the lower form 510. The recess 512 has a shape obtained by cutting a substantially cylindrical form in half vertically. Note that the surface in which the recess 512 is formed is not limited to a curved or flat surface, but may have an unevenness.
[0039] The upper form 520 has a projection 522 encompassed by a second outer edge 521. More precisely, the projection 522 is a region that extends from the second outer edge 521 of the upper form 520. The projection 522 has a shape obtained by cutting an essentially cylindrical form in half vertically. When the lower form 510 is closed with the upper form 520, the first outer edge 511 and the second outer edge 521 are brought into contact, and the projection 522 is received into the recess 512, forming a cavity 501 between the recess 512 and the projection 522. Note that the surface on which the protrusion 522 is formed is not limited to a curved surface or a flat surface, but may have an unevenness.
[0040] Now, cavity 501 will be described in more detail. As shown in the cross-sectional view in Fig. As shown in Figure 10, the cavity 501 is a region bounded and formed by the lower mold 510 and the upper mold 520, and is formed within the recess 512 of the lower mold 510. In other words, the cavity 501 is formed only within the recess 512 of the lower mold 510 and is not formed on the side of the upper mold 520. At the location of the highest region of the cavity 501, a vent 502 is provided, extending horizontally perpendicular to the vertical direction of gravity and parallel to the surfaces of the first outer edge 511 and the second outer edge 521. The vent 502 connects the highest region of the cavity 501 to the exterior of the resin mold 500.
[0041] The first outer edge 511 of the lower form 510 and the second outer edge 521 of the upper form 520 are areas that face each other and partially contact each other when the lower form 510 is closed with the upper form 520, and several recessed surfaces 513 and 523, which act as vents, are arranged at intervals at points where the lower form 510 and the upper form 520 face each other. As shown in Fig. 8(A) in a top view of the upper form 520 and in Fig. 8(B) shown in a top view of the lower form 510, the recessed surfaces 513, 523 have the same width and the same distance from other, adjacent recessed surfaces 513, 523.
[0042] Now, the vent 502 will be described in more detail. As in Fig. As shown in Figure 10, when the lower mold 510 is closed with the upper mold 520, a vent 502 is formed at the point where the first outer edge 511 and the second outer edge 521 face each other via a gap formed by the recessed surfaces 513, 523, and in the highest region of the cavity 501. That is, several vents 502 of the same width are formed by the multiple recessed surfaces 513, 523. The vent 502 connects the highest region of the cavity 501 with the exterior of the resin mold 500. Therefore, the vent 502 releases gas present in the cavity 501 of the resin mold 500 to the outside of the resin mold 500. Furthermore, the cavity 501 formed in the recess 512 of the lower mold 510, as shown in Figure 10, is also connected to the upper mold 500. Fig. 8 shown, rectangular in plan view, and the recessed surfaces 513 are provided in the four corners, i.e., in the corner areas of the area defined by the dashed lines in Fig. 8(B) indicated rectangle, so that the vents 502 connecting the corner areas of the rectangle and the exterior of the resin mold 500 are formed when the lower mold 510 is closed with the upper mold 520.
[0043] Next, a resin mold 600 is used to form the upper heat-insulating component 41 of the foamed heat-insulating components 40 as a resin component with reference to the Fig. 12 described in more detail. Fig. Figure 12 is a top view showing a resin mold for forming the upper heat-insulating component 41 according to the present embodiment.
[0044] The resin casting mold 600 for shaping the upper heat-insulating component 41 consists of a Fig. 12(A) shown upper form 620 and one in Fig. 12(B) lower form shown, and by closing the lower form 610 with the upper form 620 it is possible to pour a resin material that fills a cavity encompassed and formed by the lower form 610 and the upper form 620.
[0045] As in Fig. As shown in Figure 12(B), the lower form 610 has a recess 612 encompassed by a first outer edge 611. More precisely, the recess 612 is a region projecting from the first outer edge 611 of the lower form 610. Furthermore, the recess 612 has a substantially circular, bowl-like shape when viewed from above. Note that the surface in which the recess 612 is formed is not limited to curved or flat surfaces, but may have an unevenness.
[0046] As in Fig. As shown in Figure 12(A), the upper form 620 has a projection 622 encompassed by a second outer edge 621. More precisely, the projection 622 is a region projecting from the second outer edge 621 of the upper form 620. Furthermore, the projection 622 is substantially circular in plan view and has a shape exhibiting a curved surface. When the lower form 610 is closed with the upper form 620, the first outer edge 611 and the second outer edge 621 are brought into contact with each other, and the projection 622 is received into the recess 612, thereby forming a cavity 601 between the recess 612 and the projection 622. Note that the surface on which the protrusion 622 is formed is not limited to curved or flat surfaces, but may have an unevenness.
[0047] Now, cavity 601 will be described in more detail. As shown in the cross-sectional view of Fig. As shown in Figure 13, the cavity 601 is a region encompassed by the lower mold 610 and the upper mold 620 and formed in the recess 612 of the lower mold 610. In other words, the cavity 601 is formed only in the recess 612 of the lower mold 610 and is not formed on the side of the upper mold 620. At the location of the highest region of the cavity 601, a vent 602 is provided, extending horizontally perpendicular to the vertical direction of gravity and parallel to the surfaces of the first outer edge 611 and the second outer edge 621, and the vent 602 connects the highest region of the cavity 601 to the exterior of the resin mold 600.
[0048] The first outer edge 611 of the lower form 610 and the second outer edge 621 of the upper form 620 are areas that face each other and partially contact each other when the lower form 610 is closed with the upper form 620, and several recessed surfaces 613 and 623, which act as vents, are arranged at intervals at locations where the lower form 610 and the upper form 620 face each other. As shown in Fig. As shown in Figure 12, the recessed surfaces 613, 623 have the same width and the same distance from other, adjacent recessed surfaces 613, 623.
[0049] Now, the vent 602 will be described in more detail. As in Fig. As shown in Figure 13, when the lower mold 610 is closed with the upper mold 620, a vent 602 is formed at the point where the first outer edge 611 and the second outer edge 621 face each other via a gap formed by the recessed surfaces 613, 623, and in the highest region of the cavity 601. That is, several vents 602 of the same width are formed by the multiple recessed surfaces 613, 623. The vent 602 connects the highest region of the cavity 601 with the exterior of the resin mold 600. Therefore, the vent 602 releases any gas present in the cavity 601 of the resin mold 600 to the outside of the resin mold 600.
[0050] The following describes a method for manufacturing the hot water storage tank unit 100 using the two resin casting molds 500, 600.
[0051] In the process for manufacturing the hot water storage tank unit 100, the hot water storage tank 10, the outer housing 50 that accommodates the hot water storage tank 10, and the resin molds 500, 600 for foaming the foamed heat-insulating components 40 are first produced. Note that the hot water storage tank 10 has the structure described above.
[0052] Next, the resin molds are used to foam the upper heat-insulating component 41, the heat-insulating component 42 for the front part, the heat-insulating component 43 for the rear part and the lower heat-insulating component 44, which form the foamed heat-insulating component 40.
[0053] Now, a method for shaping the heat-insulating component 42 for the front part using the resin casting mold 500 is described with reference to the Fig. 9 to Fig. 11 described. Fig. Figure 9 is a perspective view to illustrate the manufacturing process for the hot water storage tank unit 100 using the resin casting mold 500, and Fig. Figure 10 is a cross-sectional view to illustrate the manufacturing process for the hot water storage tank unit 100 using the resin casting mold 500. Fig. Figure 11 is a schematic view showing the heat-insulating component 42 for the front part, formed using the resin casting mold 500.
[0054] First, as in Fig. Figure 9 shows the resin mold 500 being produced, and while a spray head 900 is moved to inject a resin as indicated by the arrow, a resin material, as a liquid mixture, is injected into the recess 512 of the lower mold 510. This involves overfilling, i.e., filling with a larger quantity of resin material than that obtained by multiplying the volume of the product shape by the free-form density of the resin material, i.e., the density after foaming in an unloaded state.
[0055] After the resin material has been injected into the recess 512 of the lower mold 510, the lower mold 510 is closed with the upper mold 520 to be pressurized. Then a resin material 400 foams up, as shown in Fig. As shown in Figure 10, the resin material 400 expands and fills the cavity 501 between the upper mold 520 and the lower mold 510. The gas present in the cavity 501 is released from the vent 502 to the outside of the resin mold 500 as the resin material 400 foams and fills the cavity 501 from the bottom to the top. Due to the overfilling with the resin material 400, when the entire cavity 501 is filled, the vent 502 formed by the upper mold 520, the lower mold 510, and the recessed surfaces 513, 523 is also filled, and then the resin material 400 hardens.
[0056] The gas in the cavity 501 is released into the exterior of the resin mold 500 through the several vents 502 connected to the highest area of the cavity 501, thus eliminating the need for pumping. Therefore, a mold with a simpler structure can be used.
[0057] The heat-insulating component 42 for the front part is formed as described above and then removed from the resin mold 500. As shown schematically in Fig. As shown in Figure 11, the removed heat-insulating component 42 for the front part has several burrs 42b from the resin material forming the vent 502 of the resin mold 500. That is, the heat-insulating component 42 for the front part has several burrs 42b of a parting surface 42a in contact with the heat-insulating component 44 for the rear part. Since the vent 502 has the same width, the several burrs 42b also have the same width W. The height H of the in Fig. For example, the burr shown in section 42b is 1 mm or more and 20 mm or less.
[0058] The ridge 42b is a region formed in such a way that, when the outside of the hot water storage tank 10 is covered with the respective divided heat-insulating component, a part of the division surface 42a of the heat-insulating component 42 protrudes for the front part parallel to the division surface 42a on the side facing away from the hot water storage tank 10.
[0059] Similarly, the heat-insulating component 43 for the rear section can be foamed using a resin mold with the same configuration as the resin mold 500. Like the heat-insulating component 42 for the front section, the heat-insulating component 43 for the rear section also has several ridges formed on the side facing away from the hot water storage tank 10, parallel to the parting surface and in contact with the heat-insulating component 42 for the front section.
[0060] In this case, the parting surfaces can be joined to cover the hot water storage tank 10 even if each of the ridges has a small thickness, even if the ridges 42b formed on the parting surface 42a of the heat-insulating component 42 for the front part and the ridges formed on the parting surface of the heat-insulating component 43 for the rear part are in contact with each other. To prevent the contact surfaces containing the parting surfaces and the ridges between the heat-insulating component 42 for the front part and the heat-insulating component 43 for the rear part from interfering with each other, the vents in the respective resin molds can be provided alternately, and the ridges can be formed alternately when attached to the hot water storage tank.
[0061] Now, a method for forming the upper heat-insulating component 41 using the resin casting mold 600 is described with reference to the Fig. 13 and Fig. 14 described. Fig. Figure 13 is a cross-sectional view to illustrate the manufacturing process for the hot water storage tank unit 100 using the resin casting mold 600. Fig. Figure 14 is a schematic view showing the upper heat-insulating component 41 formed using the resin casting mold 600.
[0062] First, the resin mold 600 is produced, and a resin material, as a liquid mixture, is injected into the recess 612 of the lower mold 610 using a resin injection head. This involves overfilling, i.e., filling with a larger quantity of resin material than that obtained by multiplying the volume of the product shape by the free-form density of the resin material (i.e., the density after foaming in an unloaded state).
[0063] After the resin material has been injected into the recess 612 of the lower mold 610, the lower mold 610 is closed with the upper mold 620 to be pressurized. Then a resin material 400 foams up, as described in Fig. As shown in Figure 13, the resin material 400 expands and fills the cavity 601 between the upper mold 620 and the lower mold 5610. The gas present in the cavity 601 is released from the vent 602 into the exterior of the resin mold 600 as the resin material 400 foams and fills the cavity 601 from the bottom to the top. Due to the overfilling with the resin material 400, when the entire cavity 601 is filled, the vent 602 formed by the upper mold 620, the lower mold 610, and the recessed surfaces 613, 623 is also filled, and then the resin material 400 hardens.
[0064] The gas in the cavity 601 is released into the exterior of the resin mold 500 through the several vents 502 connected to the highest area of the cavity 501, thus eliminating the need for pumping. Therefore, a mold with a simpler structure can be used.
[0065] The upper heat-insulating component 41 is formed as described above and then removed from the resin mold 600. As shown schematically in Fig. As shown in Figure 14, the removed upper heat-insulating component 41 has several burrs 41b from the resin material forming the vent 602 of the resin mold 600. That is, the upper heat-insulating component 41 has several burrs 41b on a parting surface 41a in contact with the heat-insulating component 42 for the front part and the heat-insulating component 43 for the rear part. Since the vent 602 has the same width, the several burrs 41b also have the same width. The height of the burr 41b is, for example, 1 mm or more and 20 mm or less.
[0066] The ridge 41b is a region formed in such a way that, when the outside of the hot water storage tank 10 is covered with the respective divided heat-insulating component, a part of the division surface 41a of the upper heat-insulating component 41 protrudes parallel to the division surface 41a on the side facing away from the hot water storage tank 10.
[0067] In this arrangement, the dividing surface of the upper thermally insulating component 41 can be formed with a projection in contact with the thermally insulating component 42 for the front part and the thermally insulating component 43 for the rear part, a portion of which projects towards the thermally insulating component 42 for the front part or the thermally insulating component 43 for the rear part, for the purpose of alignment with the thermally insulating component 42 for the front part and the thermally insulating component 43 for the rear part. A portion of the dividing surface of the thermally insulating component 42 for the front part or of the thermally insulating component 43 for the rear part corresponding to the projection is formed in a pressed shape, whereby the projection and the portion of the dividing surface engage to facilitate alignment.Note that the projection serves to facilitate alignment between the split heat-insulating components and is formed in such a way that it protrudes beyond the thickness of the ridge formed on the split surface.
[0068] Similarly, the lower heat-insulating component 44 can be foamed using a resin mold with the same configuration as the resin mold 600. Like the upper heat-insulating component 41, the lower heat-insulating component 44 also has several ridges formed on the side facing away from the hot water storage tank 10, parallel to the parting surface, in contact with the heat-insulating component 42 for the front part and the heat-insulating component 43 for the rear part.
[0069] Note that the burrs formed on the respective split thermal insulation components can be cut off as needed, leaving base areas intact. This ensures the suitability of the split foamed thermal insulation component 40 for installation and reduces the risk of burr breakage due to contact with other parts, resulting in a hot water storage tank unit 100 with improved thermal insulation.
[0070] After each of the divided thermally insulating components has been foamed in this manner, the foamed thermally insulating component 40, consisting of the upper thermally insulating component 41, the thermally insulating component 42 for the front part, the thermally insulating component 43 for the rear part, and the lower thermally insulating component 44, is attached to the outside of the hot water storage tank 10. The dividing surface 42a of the thermally insulating component 42 for the front part and the dividing surface of the thermally insulating component 43 for the rear part are joined together.The dividing surfaces of the upper areas of the thermally insulating component 42 for the front part and of the thermally insulating component 43 for the rear part, and the dividing surface of the upper thermally insulating component 41, and the dividing surfaces of the lower areas of the thermally insulating component 42 for the front part and of the thermally insulating component 43 for the rear part, and the dividing surface of the lower thermally insulating component 44 are joined together. Then the hot water storage tank 10 and the foamed thermally insulating component 40 are placed in the outer housing 50. In this way, the hot water storage tank unit 100 is manufactured.
[0071] A description is given of the effects of the resin casting mold, the method for manufacturing the hot water storage tank unit and the hot water storage tank unit according to the present embodiment.
[0072] In the conventional method for manufacturing the heat-insulating component using a resin mold, the problem was that during the foaming process, gas was trapped in the upper part of the mold cavity, preventing the resin material from spreading throughout the entire cavity. In the resin mold of the present embodiment, a vent connected to the highest part of the cavity prevents gas from accumulating there, allowing the resin material to spread evenly and thus improving the formability of the heat-insulating component.
[0073] In the hot water storage tank unit of the present invention, although the surface of each divided heat-insulating component is as in Fig. Figure 5 shows a complicated uneven shape, and by using the resin casting mold described above, a vent is formed in connection with the highest area of the cavity to prevent the accumulation of gas, so that the effect of improving formability is particularly great.
[0074] Furthermore, in the method for manufacturing the hot water storage tank unit according to the present embodiment, because the resin material is able to reach the point of the parting surface and is then shaped, the effect is achieved that it is possible to avoid the formation of a gap at the parting point of the heat-insulating component and to obtain a hot water storage tank unit with improved heat insulation.
[0075] Furthermore, the ridges formed in the hot water storage tank unit of the present embodiment are characterized in that they extend parallel to the dividing surface towards the side facing away from the hot water storage tank. This prevents the ridges from interfering with another divided heat-insulating component at the interface, thus facilitating installation on the outside of the hot water storage tank. Because the ridges extend parallel to the dividing surface, the contact area is increased due to their alignment with ridges formed on another divided heat-insulating component, further simplifying installation.
[0076] In particular, the cavity 501 in the resin casting mold 500 is formed in the rectangular recess 512 for foaming the heat-insulating component 42 for the front part and the heat-insulating component 43 for the rear part, but in this case there is a concern that in the four corner areas, which are the points, of the Fig. Gas could be trapped in the rectangle indicated by the dashed lines in Figure 8(B). Therefore, in the resin mold 500 of the present embodiment, the vents 502 connected to the exterior are formed in the four corner regions, i.e., the corner regions of the rectangle, so that the effect of further improving the formability at the end of the parting surface is achieved.
[0077] Furthermore, in the method for manufacturing the resin mold and the hot water storage tank unit according to the present embodiment, because the vents are provided with the same width, the effect is achieved that the flow of the resin material during foaming can be made uniform and the formability is further improved.
[0078] In order to ensure a uniform flow of the resin material, in addition to ensuring that the vents are of the same width, it is advantageous to provide adjacent vents at equal intervals, as described in the present embodiment.
[0079] For example, as in the case of the split thermally insulating components forming the foamed thermally insulating component 40 shown in the present embodiment, the width of the vent can be increased in areas where the thickness is greater and a large amount of resin material is required, if the surface has irregularities and the overall thickness is not uniform. This makes it easier for the resin material to spread uniformly even if the thickness of the split thermally insulating component varies considerably overall, thereby improving the formability of the dividing surface.
[0080] In the present embodiment, a configuration has been described in which the hot water storage tank 10 is covered and thermally insulated with the foamed heat-insulating component 40, but a vacuum thermal insulation material can be provided to improve the thermal insulation.
[0081] Modifications to the hot water storage tank unit according to the first embodiment are described with reference to Fig. 15 described. Fig. Figure 15 is a perspective view to illustrate the division positions of the heat-insulating components of the hot water storage tank unit according to each modification of the present embodiment.
[0082] For the hot water storage tank unit 100 of the present embodiment, the case has been described in which the foamed heat-insulating component 40 consists of four divided heat-insulating components, namely the upper heat-insulating component 41, the heat-insulating component 42 for the front part, the heat-insulating component 43 for the rear part, and the lower heat-insulating component 44. However, the present disclosure is not limited to this, and the dividing point can be, as in the Fig. 15(A) to Fig. 15(D) shown, can be modified, and the foamed heat-insulating component 40 can be divided into two or more parts and foamed.
[0083] In Fig. 15(A) is a foamed heat-insulating component 410 formed from two components, namely a front heat-insulating component 411 and a rear heat-insulating component 412. In this case as well, by using a resin casting mold in which vents connected to the highest area of the cavity are formed, burrs are formed on the parting surface, and a hot water storage tank unit with improved heat insulation can be obtained.
[0084] In Fig. 15(B) is a foamed heat-insulating component 420 formed from three components, namely a heat-insulating component 421 for the front part, a heat-insulating component 422 for the rear part, and a lower heat-insulating component 423. In this case as well, by using a resin mold in which vents connected to the highest area of the cavity are formed, burrs are formed on the parting surface, and a hot water storage tank unit with improved heat insulation can be obtained.
[0085] In Fig. 15(C) is a foamed thermally insulating component 430 formed from three components, namely an upper thermally insulating component 431, a thermally insulating main component 432 and a lower thermally insulating component 423. In this case as well, by using a resin casting mold in which vents connected to the highest area of the cavity are formed, burrs are formed on the parting surface, and a hot water storage tank unit with improved thermal insulation can be obtained.
[0086] In Fig. 15(D) is a foamed thermally insulating component 440 formed from two components, namely an upper thermally insulating component 441 and a lower thermally insulating component 442. In this case as well, by using a resin mold in which vents connected to the highest area of the cavity are formed, ridges are created on the parting surface, and a hot water storage tank unit with improved thermal insulation can be obtained. In particular, a design modification can be easily made if required, such as a modification in which the upper thermally insulating component 441 is formed from rigid polyurethane foam and the lower thermally insulating component 442 is formed from styrene foam.
[0087] Note that the location of the dividing surface is not limited to the one mentioned above. For manufacturing efficiency, the number of parts of the divided thermal insulation component to be attached to a hot water storage tank 10 is preferably smaller, because the number of attachment steps is reduced.
[0088] Modifications to the resin casting mold according to the first embodiment are described with reference to the Fig. 16 to Fig. 18 described. For the resin casting molds 500, 600 of the present embodiment, the case has been described in which the recessed surfaces for forming the vents are formed uniformly in the first outer edge and the second outer edge. However, the present description is not limited to this, and as in the Fig. 16 to Fig. As shown in Figure 18, the position and distance of the vents can be changed.
[0089] Fig. Figure 16 shows a top view of the lower mold 510 in a modification of the resin mold 500 for forming the heat-insulating component 42 for the front part. Note that the top view of the upper mold 520 corresponds to the top view of the lower mold 510 and is therefore omitted. In the heat-insulating component 42 for the front part, the vents can be arranged at least at locations on the parting surface 42a that are in contact with the heat-insulating component 43 for the rear part, that is, on the long-axis side, and no vent is formed on the short-axis side. With this configuration, the parting surface 42a can be formed with improved formability. The vents in the resin mold for forming the heat-insulating component 43 for the rear part can also be provided at similar locations.
[0090] Fig. 17 and Fig. Figure 18 are top views showing the lower mold 610 in a modification of the resin mold 600 for foaming the upper heat-insulating component 41. Note that the top view of the upper mold 620 corresponds to the top view of the lower mold 610 and is therefore omitted. In the upper heat-insulating component 41, with the parting surface 41a provided in top view around the entire outer circumference of the recess 612, it is sufficient that the vents are provided on the entire surface. It should be mentioned that the number of multiple vents does not depend on the one shown in Figure 1. Fig. The number shown in Figure 12 is limited. Similarly, vents can be provided in similar locations on the resin mold used to form the lower heat-insulating component 44. Second embodiment
[0091] A resin mold, a method for manufacturing a hot water storage tank unit using the resin mold, and a hot water storage tank unit according to a second embodiment are described with reference to the Fig. 19 to Fig. 21 described. Fig. Figure 19 is a perspective view showing a resin mold 500 for forming a heat-insulating component for the front part, which is provided in the hot water storage tank unit according to the present embodiment, and Fig. Figure 20 is a top view showing the resin casting mold 500. Fig. Figure 21 is a cross-sectional view to illustrate a manufacturing process for the hot water storage unit using the resin casting mold 500.
[0092] As in Fig. As shown in Figure 19, the resin mold 500 of the present embodiment differs from the resin mold 500 of the first embodiment in that the second outer edge 521 of the upper mold 520 further comprises a flat surface 524 for forming a flat parting surface. Other configurations of the resin mold, the method for manufacturing the hot water storage tank unit using the resin mold, and the hot water storage tank unit according to the present embodiment are the same as those of the first embodiment, and therefore the main difference is described below.
[0093] As in Fig. 19 and Fig. As shown in Figure 20, the flat surface 524 is part of the second outer edge 521 of the upper shape 520 and is located on the inner circumferential side of the outer circumferential side where the vent 502 is formed. That is, if, as in Fig. As shown in Figure 21, where the lower form 510 is closed with the upper form 520, the flat surface 524 is an area that forms the upper surface of the cavity 501, and an area formed in contact with the flat surface 524 is the dividing surface of the heat-insulating component 42 for the front part. The recessed surface 523 provided at the second outer edge 521 of the upper form 520 is provided such that it is recessed further than the flat surface 524.
[0094] Therefore, when the lower form 510 is closed with the upper form 520, the flat surface 524 of the recess 512 of the lower form 510 faces the recess, while the outer circumferential area of the second outer edge 521, excluding the flat surface 524, faces the first outer edge 511 of the lower form 510. The recessed surface 513 provided at the first outer edge 511 of the lower form 510 faces the recessed surface 523 provided at the second outer edge 521 of the upper form 520, thus, as shown in Fig. 21 shows that the vent 502 is formed, and the upper surface of the vent 502 is arranged above the highest area of the cavity 501.
[0095] This can, as in Fig. Figure 21 shows that the heat-insulating component 42 for the front part, formed by means of the resin mold 500 of the present embodiment, exhibits a level difference between the parting surface and the burrs due to the height difference between the flat surface 524 and the recessed surface 523. Even in this case, the level difference between the parting surface and the burrs is small, and it can therefore be said that the burrs are formed along the parting surface. To prevent the burrs at the boundary between the heat-insulating component for the front part and the heat-insulating component for the rear part from interfering with each other, the locations where the vents are formed in the respective resin molds can alternate; however, if the thickness H of the burr filling the vent 502 is small, there is no problem even if the locations of the vents do not alternate.
[0096] Similarly, the resin mold 600 described in the first embodiment for foaming the upper heat-insulating component can be configured to have a flat surface on the inner circumferential side of the second outer edge 621 of the upper mold 620.
[0097] With the resin mold configured as described above, the method for manufacturing a hot water storage tank unit using the resin mold, and the hot water storage tank unit according to the present embodiment, not only can the same effects be achieved as with the first embodiment, but the parting surface can be formed flat, so that the further effect of obtaining a heat-insulating component with further improved thermal insulation can be achieved. Third embodiment
[0098] A resin mold, a method for manufacturing a hot water storage tank unit using the resin mold, and a hot water storage tank unit according to a third embodiment are described with reference to the Fig. 22 to Fig. 24 described. Fig. Figure 22 is a perspective view showing a resin mold 500 for forming a heat-insulating component for the front part, which is provided in the hot water storage tank unit according to the present embodiment, and Fig. Figure 23 is a top view showing the resin casting mold 500. Fig. Figure 24 is a cross-sectional view to illustrate a manufacturing process for the hot water storage unit using the resin casting mold 500.
[0099] As in Fig. 22 to Fig. As shown in Figure 24, the resin mold 500 of the present embodiment differs from the resin mold 500 of the first embodiment in that the second outer edge 521 of the upper mold 520 does not have a recessed surface 523. Other configurations of the resin mold, the method for manufacturing the hot water storage tank unit using the resin mold, and the hot water storage tank unit according to the present embodiment are the same as those of the first embodiment, and therefore the main difference is described below.
[0100] The second outer edge 521 of the upper shape 520 is formed with no recessed surface and is therefore a flat surface without irregularities. In the Fig. 22 to Fig. 24 is a region corresponding to the flat surface 524 of the second embodiment, as shown in the flat surface 524, but there is no level difference or the like at its boundary. The flat surface 524 is a surface for forming a parting surface and is located at a position facing the recess 512 of the lower shape 510. On the other hand, the outer circumferential region of the second outer edge 521, excluding the flat surface 524, faces the first outer edge 511 of the lower shape 510. Therefore, the recessed surface 513 of the flat surface provided at the first outer edge 511 of the lower shape 510 faces the outer circumferential side of the second outer edge 521 of the upper shape 520, whereby, as shown in Fig. 24 shows the vent 504 being formed.
[0101] Similarly, the resin mold 600 described in the first embodiment for foaming the upper heat-insulating component can be configured such that it does not have a recessed surface 623 at the second outer edge 621 of the upper mold 620.
[0102] With the resin mold configured as described above, the method for manufacturing a hot water storage tank unit using the resin mold, and the hot water storage tank unit according to the present embodiment, not only can the same effects be achieved as with the first embodiment, but the parting surface can be formed flat, and because the ridges are formed parallel along the parting surface, the effect is achieved that the alignment of the divided heat-insulating components becomes easy, and a heat-insulating component with further improved thermal insulation can be obtained.
[0103] Note that suitable combinations, modifications and omissions of the embodiments are within the scope of the present disclosure. Reference symbol list 10 hot water storage tanks 21 Heat pump supply line 22 Heat pump return line 23 Pressure reducing valve 24 Relief valve 25 Mixing valve 26 Switching valve 27 Check valve 28 Cold water pipe 29 Heat source pump 30 Temperature sensor 31 Hot water pipe 32 branched water supply lines 33 Hot water supply line 34 Hot water supply line connection 40, 410, 420, 430, 440 heat-insulating components 41 upper heat-insulating component 41a Division surface 41b Grat 42 heat-insulating component for the front part 42a Division surface 42b Grat 43 heat-insulating component for the rear part 44 lower heat-insulating component 50 outer casing 51 Front panel 52 Base plate 53, 54 Side panel 55 Backplate 56 Cover plate 57 Base plate 60 feet 100 Hot water storage tank unit 110 Heat pump unit 400 resin material 411 front heat-insulating component 412 rear heat-insulating component 421 heat-insulating component for the front part 422 Heat-insulating component for the rear part 423 lower heat-insulating component 431 upper heat-insulating component 432 heat-insulating component for the main part 433 lower heat-insulating component 441 upper heat-insulating component 442 lower heat-insulating component 500, 600 resin casting mold 501, 601 cavity 502, 602 Ventilation 510, 610 lower form 511, 611 first outer edge 512, 612 Exclusion 513, 613 receding surface 520, 620 upper form 521, 621 second outer edge 522, 622 Emphasis 523, 623 receding surface 524 flat surface 1000 hot water heaters of the hot water storage type QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] JP 2008107015 A
[0003]
Claims
[1] Resin mold for foaming a heat-insulating resin component, comprising the resin mold: a lower form with a recess and a first outer edge as the outer edge of the recess; an upper shape with a protrusion that fits into the recess, and a second outer edge as the outer edge of the protrusion; wherein the protrusion, when the lower form is closed with the upper form to form a cavity, is incorporated into the recess and wherein several vents, as places where the first outer edge and the second outer edge face each other via a gap, connect the uppermost section of the cavity and the exterior of the resin casting mold. [2] Resin casting mold according to claim 1, wherein each of the multiple vents has the same width. [3] Resin casting mold according to claim 1 or 2, wherein the multiple vents are provided such that they extend in a horizontal direction. [4] Resin mold according to one of claims 1 to 3, wherein a recessed surface provided at the first outer edge and a recessed surface provided at the second outer edge are facing each other to form the multiple vents. [5] Resin mold according to any one of claims 1 to 3, wherein a recessed surface provided at the first outer edge and a flat surface provided at the second outer edge are facing each other to form the multiple vents. [6] Resin mold according to any one of claims 1 to 5, wherein the cavity is rectangular in plan view and the vents are provided such that they connect four corners of the cavity and the exterior of the resin mold. [7] Method for manufacturing a hot water storage tank unit, the method comprising the following steps: Injecting a resin material into the recess of the lower form of the resin casting mold according to one of claims 1 to 6; Foaming the resin component by sealing the lower mold with the upper mold, pressurizing it, foaming the resin material, filling the cavity and vents, and then curing the resin material; and Attaching the foamed resin component to the circumference of a hot water storage tank. [8] Hot water storage tank unit comprising: a hot water storage tank for storing water, and a heat-insulating foam component covering the circumference of the hot water storage tank, wherein the heat-insulating foam component is divided into several heat-insulating components and has several ridges formed on a side opposite the hot water storage tank along a dividing surface between the divided heat-insulating components. [9] Hot water storage tank unit according to claim 8, wherein the multiple ridges are provided such that they extend in a direction parallel to the dividing surface. [10] Hot water storage tank unit according to claim 9, wherein the split heat-insulating component comprises: an upper heat-insulating component that covers an upper section of the hot water storage tank; a lower heat-insulating component that covers a lower section of the hot water storage tank; a heat-insulating component for the front part, which is provided in contact with the upper heat-insulating component and the lower heat-insulating component and covers a front side of the body of the hot water storage tank; and a heat-insulating component for the rear part, which is provided in contact with the upper heat-insulating component, the lower heat-insulating component and the heat-insulating component for the front part, and covers a rear side of the body of the hot water storage tank. [11] Hot water storage tank unit according to claim 10, wherein the upper heat-insulating component, the front heat-insulating component and the rear heat-insulating component are formed from rigid polyurethane foam. [12] Hot water storage tank unit according to claim 10 or 11, wherein the lower heat-insulating component is formed from styrene foam. [13] Hot water storage tank unit according to any one of claims 8 to 12, wherein each of the multiple ridges has the same width. [14] Hot water storage tank unit according to one of claims 8 to 13, wherein the multiple ridges are provided such that adjacent ridges are equally spaced apart. [15] Hot water storage tank unit according to any one of claims 8 to 14, wherein the multiple ridges are cut off while their base sections remain.