Method for manufacturing ion exchanger case

Abstract

To provide a method for manufacturing an ion exchanger case that can suppress deterioration in moldability of the case.SOLUTION: A method for manufacturing a case 20 includes a molding step of integrally molding two housing parts 21 and an inlet pipe 30 by injecting a resin R into a cavity 80a formed in a mold 80 including two first dies 81 that mold inner surfaces of the two housing parts 21, respectively, and a columnar second die 85 that molds an inner surface of the inlet pipe 30. The first die 81 has a first molding part 82 that molds the inner surfaces of the housing parts 21, and a second molding part 83 that protrudes from the first molding part 82 and molds an inlet-side communicating part 35. The second molding part 83 is configured to be able to hold the second die 85 by fitting the second molding die 85 into it. In the molding step, the resin R is injected into the cavity 80a with the second molding die 85 fitted into the second molding part 83.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a case for an ion exchanger. [Background technology]

[0002] Conventionally, fuel cells have been designed to suppress temperature rise during power generation by using cooling water circulating inside the fuel cell. When ions are eluted into the cooling water as the fuel cell generates power, the conductivity of the cooling water increases. This can result in a decrease in the performance of the fuel cell due to electrical leakage through the cooling water. For this reason, fuel cells are connected to ion exchangers that remove ions from the cooling water by passing the cooling water through ion exchange resin.

[0003] The ion exchanger described in Patent Document 1 includes a cylindrical case that opens upward, and a cartridge that is detachably attached to the case. The case has a housing formed by a lower base and a cylindrical portion protruding upward from the lower base. The case has a cooling pipe (referred to as a pipe portion in Patent Document 1) through which cooling water flows. The cooling pipe extends linearly along the lower base and is formed integrally with the housing. The lower base separates the internal space of the cooling pipe from the internal space of the housing. The lower base has inlet and outlet holes that communicate the internal space of the cooling pipe with the internal space of the housing.

[0004] The cartridge includes a cylindrical housing that opens downward, a pipe section that is arranged vertically within the housing, and ion exchange resin that is filled around the pipe section. The pipe section protrudes downward from the inner surface of the top wall of the housing. The upper end of the pipe section has an opening that allows cooling water to pass through. The lower end of the pipe section is connected to the outflow hole.

[0005] The cooling water flows through the cooling pipe from the bottom to the top of the container through the inlet. As the cooling water passes through the ion exchange resin in the cartridge, ions are removed from the cooling water. The cooling water then flows into the pipe through the opening at the top end. The cooling water then flows out of the cooling pipe through the outlet connected to the bottom end of the pipe. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-176935 Summary of the Invention [Problem to be solved by the invention]

[0007] The case of the ion exchanger is manufactured, for example, by integrally molding the housing portion and the cooling pipe by injection molding. That is, the housing portion and the cooling pipe are integrally molded by injecting resin into a cavity formed in a mold including a first mold for molding the inner surface of the housing portion and a second mold for molding the inner surface of the cooling pipe.

[0008] Here, the second mold is columnar in shape to match the shape of the linearly extending cooling pipe. Therefore, the longer the cooling pipe, the longer the second mold. The longer the second mold, the more likely it is to deform due to the pressure of the resin during injection molding. As a result, there is a risk that the moldability of the ion exchanger case will decrease. [Means for solving the problem]

[0009] A method for manufacturing an ion exchanger case for solving the above problem includes a storage section that stores ion exchange resin and a piping that extends linearly and through which cooling water flows, the storage section having a bottom wall, and the piping having a communication section that opens to the bottom wall and connects the internal space of the piping to the internal space of the storage section in the radial direction of the piping. The method includes a molding process in which the storage section and the piping are integrally molded by injecting resin into a cavity formed in a mold that includes a first molding die that molds the inner surface of the storage section and a cylindrical second molding die that molds the inner surface of the piping. The first molding die has a first molding section that molds the inner surface of the storage section and a second molding section that protrudes from the first molding section and molds the communication section. The second molding section is configured to be able to hold the second molding section when the second molding die is fitted into it. In the molding process, the resin is injected into the cavity with the second molding die fitted into the second molding section.

[0010] According to the above configuration, during injection molding of the case, resin is injected into the cavity while the second mold is fitted into the second molding portion of the first mold. This prevents the second mold from being deformed by the pressure of the resin during injection molding, thereby preventing a decrease in moldability of the case.

[0011] A method for manufacturing an ion exchanger case for solving the above-mentioned problems includes a plurality of storage sections that are arranged in parallel and that store ion exchange resin, and a pipe that extends linearly in the arrangement direction of the plurality of storage sections and through which cooling water flows, each of the storage sections having a bottom wall, and the pipe has a plurality of communication sections that open to each of the bottom walls and communicate an internal space of the pipe with an internal space of each of the storage sections in a radial direction of the pipe, the method comprising: a plurality of first molding dies that mold the inner surfaces of the plurality of storage sections, and a cylindrical second molding die for molding the plurality of storage sections and the piping, by injecting resin into a cavity formed in a mold, each of the first molding dies having a first molding section for molding the inner surface of the storage section and a second molding section protruding from the first molding section and for molding the communicating section, each of the second molding sections being configured to be able to hold the second molding section by fitting the second molding die into it, and in the molding process, the resin is injected into the cavity with the second molding die fitted into each of the second molding sections.

[0012] According to the above configuration, during injection molding of the case, resin is injected into the cavity while the second mold is fitted into the second molding portion of each first mold. This prevents the second mold from being deformed by the pressure of the resin during injection molding, thereby preventing a decrease in moldability of the case. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of an ion exchanger according to one embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing an inlet pipe in the ion exchanger of FIG. [Figure 3] FIG. 3 is a perspective cross-sectional view of a case in the ion exchanger of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing an outlet pipe in the ion exchanger of FIG. [Figure 6] FIG. 6(a) is a cross-sectional view showing the state before resin is injected into the cavity that molds the inlet pipe, and FIG. 6(b) is a cross-sectional view showing the state after resin has been injected into the same cavity. [Figure 7] FIG. 7(a) is a cross-sectional view showing the state before resin is injected into the cavity that forms the outflow pipe, and FIG. 7(b) is a cross-sectional view showing the state after resin has been injected into the same cavity. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, one embodiment of a method for manufacturing an ion exchanger casing will be described with reference to FIGS. (Overall configuration of ion exchanger 10) 1, the ion exchanger 10 is connected to a cooling circuit C through which cooling water for cooling a fuel cell flows, for example. The ion exchanger 10 removes ions contained in the cooling water.

[0015] The ion exchanger 10 includes a case 20 and two cartridges 40. Each cartridge 40 is configured to be detachable from the case 20. (Overall configuration of Case 20) The case 20 includes two storage sections 21, a connecting section 27, an inlet pipe 30, and an outlet pipe 36. The two storage sections 21 are arranged in parallel with a gap between them. The connecting section 27 connects the two storage sections 21. The inlet pipe 30 allows cooling water to flow into the two storage sections 21. The outlet pipe 36 allows cooling water to flow out of the two storage sections 21. The case 20 is formed, for example, from a thermoplastic resin material. The inlet pipe 30 is an example of "piping." The outlet pipe 36 is another example of "piping."

[0016] (Configuration of the storage section 21) As shown in FIG. 2 , each storage section 21 has a bottom wall 22, a peripheral wall 23, and a protruding portion 24. The bottom wall 22 is circular in plan view. The peripheral wall 23 protrudes upward from the outer periphery of the bottom wall 22. The protruding portion 24 protrudes upward from around the center of the bottom wall 22. The protruding portion 24 is annular and surrounds the entire center of the bottom wall 22. The peripheral walls 23 of the two storage sections 21 are connected by a connecting portion 27.

[0017] An insertion opening 25, through which the cartridge 40 is inserted, is formed at the end of the peripheral wall 23 opposite the bottom wall 22. The insertion opening 25 opens upward. That is, the housing section 21 has a cylindrical shape with a closed lower end. A female screw 26 is formed on the inner peripheral surface of the insertion opening 25.

[0018] (Configuration of inlet pipe 30) 3, the inflow pipe 30 extends linearly below the two storage sections 21 in the arrangement direction of the two storage sections 21. The inflow pipe 30 extends parallel to an imaginary line connecting the centers of the bottom walls 22 of the two storage sections 21 at a position away from the imaginary line in the surface direction of the bottom walls 22. The cross-sectional shape of the flow path of the inflow pipe 30 perpendicular to the longitudinal direction is circular.

[0019] 2, the inflow pipe 30 is formed integrally with each bottom wall 22. The internal space of the inflow pipe 30 and the internal space of each storage section 21 are separated only by each bottom wall 22. In other words, the inflow pipe 30 has a peripheral wall 31 that forms part of each bottom wall 22. The peripheral wall 31 of the inflow pipe 30 is exposed to the internal space of each storage section 21.

[0020] The inflow pipe 30 has a first connection port 32 connected to the cooling circuit C. The first connection port 32 protrudes further outward from the accommodation portion 21 than the accommodation portion 21. The cooling water flowing through the cooling circuit C flows into the inflow pipe 30 through the first connection port 32.

[0021] Hereinafter, the flow direction of the cooling water flowing through the inlet pipe 30 will be simply referred to as the flow direction. In addition, of the two storage sections 21, the storage section 21 located upstream in the flow direction will be referred to as storage section 21A, and the storage section 21 located downstream will be referred to as storage section 21B. Storage section 21B is the storage section 21 located furthest downstream in the flow direction.

[0022] The inflow pipe 30 has a first tapered section 33 and a second tapered section 34. The first tapered section 33 and the second tapered section 34 are sections in which the cross-sectional area of ​​the flow passage decreases toward the downstream side in the flow direction. The second tapered section 34 is provided continuously downstream from the first tapered section 33. The degree of reduction in the cross-sectional area of ​​the flow passage of the inflow pipe 30 at the second tapered section 34 is greater than the degree of reduction in the cross-sectional area of ​​the flow passage of the inflow pipe 30 at the first tapered section 33. Note that the "degree of reduction in the cross-sectional area of ​​the flow passage" refers to the degree of inclination of the inner surface of the flow passage with respect to the central axis of the flow passage.

[0023] The portion of inflow pipe 30 where peripheral wall 31 is formed by bottom wall 22 of accommodation section 21A is first tapered section 33. The thickness of the portion of bottom wall 22 of accommodation section 21A that forms peripheral wall 31 of inflow pipe 30 is constant. That is, the portion of the inner surface of bottom wall 22 of accommodation section 21A that is the outer peripheral surface of first tapered section 33 is inclined with respect to the central axis of inflow pipe 30 and extends along the inner peripheral surface of first tapered section 33.

[0024] The portion of inflow pipe 30 where peripheral wall 31 is formed by bottom wall 22 of accommodation section 21B is second tapered section 34. The thickness of the portion of bottom wall 22 of accommodation section 21B that forms peripheral wall 31 of inflow pipe 30 is constant. That is, the portion of the inner surface of bottom wall 22 of accommodation section 21B that is the outer peripheral surface of second tapered section 34 is inclined with respect to the central axis of inflow pipe 30 and extends along the inner peripheral surface of second tapered section 34.

[0025] The boundary between the first tapered portion 33 and the second tapered portion 34 of the inflow pipe 30 is located between the two storage portions 21. A part of the boundary between the first tapered portion 33 and the second tapered portion 34 is formed by a connecting portion 27.

[0026] As shown in FIG. 3, the inflow pipe 30 has two inflow side communicating portions 35 that open to each bottom wall 22. Each inflow side communicating portion 35 communicates the internal space of the inflow pipe 30 with the internal space of the storage portion 21 in the radial direction of the inflow pipe 30. The inflow side communicating portion 35 includes a through-hole that penetrates the peripheral wall 31 of the inflow pipe 30. The internal spaces of the two inflow side communicating portions 35 have the same shape and size. The opening of each inflow side communicating portion 35 in the bottom wall 22 is substantially rectangular in plan view. The inflow side communicating portion 35 is an example of a "communicating portion."

[0027] The inlet-side communicating portion 35, which opens into the bottom wall 22 of the storage portion 21A, is located at a position offset from the center of the bottom wall 22 and midway along the length of the first tapered portion 33. In other words, the first tapered portion 33 communicates with the storage portion 21A via the inlet-side communicating portion 35.

[0028] The inlet-side communicating portion 35, which opens into the bottom wall 22 of the storage portion 21B, is located at a position offset from the center of the bottom wall 22 and is provided continuous with the tip end of the second tapered portion 34. In other words, the second tapered portion 34 communicates with the storage portion 21B via the inlet-side communicating portion 35.

[0029] 4, the internal space of each inlet-side communicating section 35 is expanded radially outward more than the internal spaces of the first tapered section 33 and the second tapered section 34. Each inlet-side communicating section 35 bulges downward in a dome shape from the bottom wall 22. The cross-sectional shape and size of each inlet-side communicating section 35 perpendicular to the flow direction are constant in the flow direction.

[0030] (Configuration of Outlet Pipe 36) 3, the outflow pipe 36 extends linearly below the two storage sections 21 in the direction in which the two storage sections 21 are arranged. The outflow pipe 36 extends on an imaginary axis connecting the centers of the bottom walls 22 of the two storage sections 21. The outflow pipe 36 extends parallel to the inflow pipe 30. The cross-sectional shape of the flow path perpendicular to the longitudinal direction of the outflow pipe 36 is circular.

[0031] As shown in Figure 5, the outflow pipe 36 is formed integrally with each bottom wall 22. The internal space of the outflow pipe 36 and the internal space of each storage section 21 are separated only by each bottom wall 22. In other words, the outflow pipe 36 has a peripheral wall 37 that forms part of each bottom wall 22. The peripheral wall 37 of the outflow pipe 36 is exposed to the internal space of each storage section 21.

[0032] The outflow pipe 36 has a second connection port 38 connected to the cooling circuit C. The second connection port 38 protrudes further toward the outer periphery of the accommodation portion 21 than the accommodation portion 21. The cooling water flowing inside the outflow pipe 36 flows into the cooling circuit C through the second connection port 38.

[0033] The second connection port 38 of the outflow pipe 36 faces the opposite side from the first connection port 32 of the inflow pipe 30 in the arrangement direction of the two storage sections 21. Therefore, the cooling water flowing in the outflow pipe 36 flows in the same direction as the cooling water flowing in the inflow pipe 30. For this reason, hereinafter, the flow direction of the cooling water flowing in the outflow pipe 36 as well as the flow direction of the cooling water flowing in the inflow pipe 30 will be simply referred to as the flow direction.

[0034] The cross-sectional area of ​​the flow path of the outflow pipe 36 increases toward the downstream side in the flow direction. In other words, the cross-sectional area of ​​the flow path of the outflow pipe 36 decreases toward the upstream side in the flow direction. The degree of reduction in the cross-sectional area of ​​the flow path of the outflow pipe 36 is the same as the degree of reduction in the cross-sectional area of ​​the flow path of the inflow pipe 30 in the first tapered section 33, for example.

[0035] The thickness of the portion of each bottom wall 22 that forms the peripheral wall 37 of the outflow pipe 36 is constant. That is, the inner surface of each bottom wall 22 that forms the outer peripheral surface of the outflow pipe 36 is inclined with respect to the central axis of the outflow pipe 36 and extends along the inner peripheral surface of the outflow pipe 36. The inner surface of the general portion of each bottom wall 22 that is different from the portions that form the inflow pipe 30 and the outflow pipe 36 is a plane that extends parallel to the central axes of the inflow pipe 30 and the outflow pipe 36.

[0036] As shown in FIG. 3 , the outflow pipe 36 has two outflow-side communicating portions 39 that open to each bottom wall 22. Each outflow-side communicating portion 39 connects the internal space of the outflow pipe 36 to the internal space of the storage portion 21 in the radial direction of the outflow pipe 36. The outflow-side communicating portion 39 includes a through-hole that penetrates the peripheral wall 37 of the outflow pipe 36. The internal spaces of the two outflow-side communicating portions 39 have the same shape and size. The internal space of each outflow-side communicating portion 39 has the same shape and size as the internal space of each inflow-side communicating portion 35. The opening of each outflow-side communicating portion 39 in the bottom wall 22 is substantially rectangular in plan view. The opening of each outflow-side communicating portion 39 is surrounded by the protrusion 24. The outflow-side communicating portion 39 is another example of a "communicating portion."

[0037] The outlet-side communicating portion 39 opening into the bottom wall 22 of the storage portion 21A is provided in the center of the bottom wall 22, at the base end of the outlet pipe 36. The outlet-side communicating portion 39 opening into the bottom wall 22 of the storage portion 21B is provided in the center of the bottom wall 22, midway along the length of the outlet pipe 36.

[0038] The internal space of each outlet-side communicating portion 39 is expanded radially outward compared to the internal space of the remaining portion of the outflow pipe 36. Each outlet-side communicating portion 39 bulges downward in a dome shape from the bottom wall 22. The cross-sectional shape and size of each outlet-side communicating portion 39 perpendicular to the flow direction are constant in the flow direction.

[0039] (Overall configuration of cartridge 40) 2 and 5, the cartridge 40 includes a cap 41, a flow path member 45, a lid member 50, and an ion exchange resin 60. The cap 41 is housed inside the housing portion 21 through the insertion opening 25. The flow path member 45 forms a flow path through which cooling water flows inside the cap 41. The lid member 50 is joined to the cap 41. The ion exchange resin 60 is housed inside the cap 41. The cap 41, the flow path member 45, and the lid member 50 are formed of, for example, a thermoplastic resin material.

[0040] (Cap 41 configuration) The cap 41 has a top wall 42 and a peripheral wall 43. The top wall 42 is circular in plan view. The peripheral wall 43 protrudes downward from the outer periphery of the top wall 42. The cap 41 is cylindrical with a closed upper end.

[0041] A male thread 44 that meshes with the female thread 26 of the accommodating portion 21 is formed on the outer peripheral surface of the peripheral wall 43. By screwing the cap 41 onto the accommodating portion 21, the cartridge 40 is detachably attached to the case 20.

[0042] A first seal ring 71 is attached to a portion of the outer peripheral surface of the peripheral wall 43 above the male threads 44. The first seal ring 71 seals between the outer peripheral surface of the cap 41 and the inner peripheral surface of the accommodating portion 21.

[0043] (Configuration of flow path member 45) The flow path member 45 has a pipe portion 46, an annular portion 47, and a plurality of first support portions 48.

[0044] The pipe portion 46 is cylindrical and extends vertically in the center of the interior of the cap 41. The upper end of the pipe portion 46 opens toward the inner surface of the top wall 42. There is a gap between the upper end of the pipe portion 46 and the top wall 42. The lower end of the pipe portion 46 opens toward the outflow side communication portion 39. The lower end of the pipe portion 46 is located inside the protrusion 24.

[0045] The annular portion 47 is annular and surrounds the upper end of the pipe portion 46. The annular portion 47 is fitted into the interior of the upper end of the cap 41. The first support portions 48 connect the outer peripheral surface of the pipe portion 46 and the inner peripheral surface of the annular portion 47 at multiple locations spaced apart in the circumferential direction of the pipe portion 46 .

[0046] A second seal ring 72 is attached to the outer circumferential surface of the annular portion 47. The second seal ring 72 seals between the outer circumferential surface of the annular portion 47 and the inner circumferential surface of the cap 41. A disk-shaped mesh member is integrated with the flow path member 45 by insert molding. The mesh member is formed from a thin metal plate such as stainless steel. The mesh member covers the lower surfaces of the annular portion 47 and the plurality of first support portions 48. The mesh member has a plurality of through holes that penetrate the mesh member in the thickness direction. Each through hole is sized to allow the passage of cooling water while preventing the passage of ion exchange resin 60.

[0047] (Configuration of the lid member 50) The cover member 50 has an inner annular portion 51, an outer annular portion 52, and a plurality of second support portions 53.

[0048] 5, the inner annular portion 51 is annular and surrounds the lower end of the pipe portion 46. The lower end of the inner annular portion 51 is located inside the protruding portion 24. The outer annular portion 52 is annular and surrounds the inner annular portion 51. The outer annular portion 52 is joined to the cap 41 in a state where it is fitted inside the lower end portion of the cap 41.

[0049] The plurality of second support portions 53 connect the outer peripheral surface of the inner annular portion 51 and the inner peripheral surface of the outer annular portion 52 at a plurality of locations spaced apart in the circumferential direction of the inner annular portion 51 . A third seal ring 73 is attached to the inner circumferential surface of the inner annular portion 51. The third seal ring 73 seals between the inner circumferential surface of the inner annular portion 51 and the outer circumferential surface of the pipe portion .

[0050] A fourth seal ring 74 is attached to the outer peripheral surface of the outer annular portion 52. The fourth seal ring 74 seals between the outer peripheral surface of the outer annular portion 52 and the inner peripheral surface of the cap 41. A disk-shaped mesh member is integrated with the lid member 50 by insert molding. This mesh member covers the lower surface of the lid member 50. This mesh member has the same configuration as the mesh member integrated with the flow path member 45.

[0051] (Configuration of ion exchange resin 60) The ion exchange resin 60 is filled in the space inside the cap 41 around the pipe portion 46 and between the annular portion 47 and the lid member 50 .

[0052] The cooling water that flows into the interior of the storage unit 21 from the inlet pipe 30 through the inlet-side communicating portion 35 passes through a mesh member integrated with the cover member 50, and reaches the region inside the cap 41 filled with ion exchange resin 60. As the cooling water passes through the ion exchange resin 60, ions are removed from the cooling water through ion exchange by the ion exchange resin 60. After passing through the ion exchange resin 60, the cooling water passes through a mesh member integrated with the flow path member 45 and then flows into the interior of the pipe portion 46 through the opening at the upper end of the pipe portion 46. The cooling water then flows into the interior of the outlet pipe 36 from the lower end of the pipe portion 46 and then flows out of the outlet pipe 36 into the cooling circuit C.

[0053] (Manufacturing method of case 20) Next, a method for manufacturing the case 20 will be described. The manufacturing method of the case 20 includes a molding step of integrally molding the two storage portions 21, the inlet pipe 30, and the outlet pipe 36 by injecting resin R into a cavity 80a formed in a mold 80.

[0054] As shown in Figures 6(a) and 7(a), the mold 80 includes two first dies 81, a second die 85, a third die 88, and a fourth die 89. Each first die 81 molds the inner surface of each storage section 21. The second die 85 molds the inner surface of the inlet pipe 30. The third die 88 molds the inner surface of the outlet pipe 36. The fourth die 89 molds the outer surface of the case 20. The first die 81 is an example of a "first molding die." The second die 85 is an example of a "second molding die." The third die 88 is another example of a "second molding die."

[0055] Each first mold 81 has a first molding portion 82 and two second molding portions 83, 84. The first molding portion 82 molds the inner surface of the storage portion 21. The second molding portion 83 molds the inner surface of the inlet side communicating portion 35. The second molding portion 84 molds the inner surface of the outlet side communicating portion 39.

[0056] A portion of the molding surface 82a that molds the inner surface of the bottom wall 22 of each first molding portion 82 extends along the outer peripheral surface of the second mold 85 so that the thickness of the cavity 80a formed between the molding surface 82a and the outer peripheral surface of the second mold 85, i.e., the vertical distance, is constant. In addition, another portion of the molding surface 82a extends along the outer peripheral surface of the third mold 88 so that the thickness of the cavity 80a formed between the molding surface 82a and the outer peripheral surface of the third mold 88, i.e., the vertical distance, is constant.

[0057] As shown in Figures 6(a) and 6(b), the second molding portion 83 protrudes downward from the molding surface 82a. Each second molding portion 83 is configured to be able to hold the second mold 85 by fitting the second mold 85. More specifically, the second molding portion 83 of the first mold 81 that molds the inner surface of the storage portion 21A has a fitting hole 83a into which the second mold 85 fits. The second molding portion 83 of the first mold 81 that molds the inner surface of the storage portion 21B has a fitting recess 83b into which the tip of the second mold 85 fits. The second mold 85 and the fitting recess 83b form a spigot structure.

[0058] As shown in Figures 7(a) and 7(b), the second molding portion 84 protrudes downward from the molding surface 82a. Each second molding portion 84 is configured to be able to hold the third mold 88 by fitting the third mold 88. More specifically, the second molding portion 84 of the first mold 81 that molds the inner surface of the storage portion 21A has a fitting recess 84a into which the tip of the third mold 88 fits. The second molding portion 84 of the first mold 81 that molds the inner surface of the storage portion 21B has a fitting hole 84b into which the third mold 88 fits. The third mold 88 and the fitting recess 84a form a spigot structure.

[0059] As shown in FIGS. 6( a) and 6(b), the second die 85 has a columnar shape corresponding to the shape of the inlet pipe 30. The second die 85 has a first tapered portion 86 and a second tapered portion 87. The first tapered portion 86 forms the inner surface of the first tapered portion 33. The second tapered portion 87 forms the inner surface of the second tapered portion 34. The first tapered portion 86 and the second tapered portion 87 are portions in which the cross-sectional area perpendicular to the longitudinal direction of the second die 85 decreases toward the tip of the second die 85. The second tapered portion 87 is provided continuously from the tip of the first tapered portion 86. The degree of reduction in the cross-sectional area of ​​the second tapered portion 87 is greater than the degree of reduction in the cross-sectional area of ​​the first tapered portion 86.

[0060] When the second die 85 is fitted to each second molding portion 83, the first tapered molding portion 86 fits into the fitting hole 83a, and the tip of the second tapered molding portion 87 fits into the fitting recess 83b. 7(a) and 7(b), the third die 88 has a columnar shape corresponding to the shape of the outflow pipe 36. The cross-sectional area of ​​the third die 88, which is perpendicular to the longitudinal direction of the third die 88, decreases toward the tip of the third die 88.

[0061] The fourth mold 89 is, for example, a split mold divided into a plurality of parts. The fourth mold 89 forms a cavity 80a for molding the case 20 between the first mold 81, the second mold 85, and the third mold 88.

[0062] As shown in Figures 6(a) and 7(a), in the molding process, the mold 80 is clamped to form a cavity 80a between each of the first mold 81, the second mold 85, the third mold 88, and the fourth mold 89.

[0063] As shown in Figures 6(b) and 7(b), in the molding process, the second mold 85 is fitted to each second molding portion 83, and the third mold 88 is fitted to each second molding portion 84, and molten resin R is injected into the cavity 80a in the mold 80.

[0064] Thereafter, the mold 80 is cooled, thereby solidifying the resin R in the cavity 80a, thereby forming the case 20. After molding, the case 20 is removed from the mold 80, which has been opened.

[0065] 6(b), in the molding process, two inlet-side communicating sections 35 having the same shape and size of their internal spaces are molded by each second molding section 83. In other words, in the molding process, an inlet-side communicating section 35 that communicates the internal space of the first tapered section 33 with the internal space of the storage section 21A is molded, and an inlet-side communicating section 35 that communicates the internal space of the second tapered section 34 with the internal space of the storage section 21B is molded.

[0066] 7(b), in the molding process, two outlet-side communicating sections 39 having the same shape and size of the internal space are molded by each second molding section 84. In other words, in the molding process, two outlet-side communicating sections 39 that respectively communicate the internal space of the outflow pipe 36 with the internal spaces of the storage sections 21A and 21B are molded.

[0067] <Operation of this embodiment> During injection molding of the case 20, the resin R is injected into the cavity 80a with the second mold 85 fitted into the second molding portion 83 of each of the first molds 81 and the third mold 88 fitted into the second molding portion 84 of each of the first molds 81. This makes it possible to prevent the second mold 85 and the third mold 88 from being deformed by the pressure of the resin R during injection molding.

[0068] <Effects of this embodiment> (1) In the molding step, with the second mold 85 fitted to each of the second molding portions 83 and the third mold 88 fitted to each of the second molding portions 84, resin R is injected into the cavity 80a.

[0069] According to the above configuration, deterioration in formability of the case 20 can be suppressed. (2) The second molding portion 83 has a fitting recess 83b into which the tip of the second die 85 fits. The second molding portion 84 has a fitting recess 84a into which the tip of the third die 88 fits.

[0070] According to the above configuration, the tip of the second die 85 fits into the fitting recess 83b, which further prevents the second die 85 from being deformed by the pressure of the resin R during injection molding. Also, the tip of the third die 88 fits into the fitting recess 84a, which further prevents the third die 88 from being deformed by the pressure of the resin R during injection molding. Therefore, deterioration in the moldability of the case 20 can be further prevented.

[0071] (3) In the molding process, resin R is injected into the cavity 80a while the second tapered molding portion 87 is fitted into the second molding portion 83, thereby molding an inlet side communication portion 35 that communicates the internal space of the second tapered portion 34 of the inlet pipe 30 with the internal space of the storage portion 21B.

[0072] Due to inertial force, the cooling water flowing inside the inflow pipe 30 tends to flow toward the downstream side of the inflow pipe 30 rather than toward each storage unit 21. In this case, the storage unit 21 that is located more downstream of the inflow pipe 30 out of the two storage units 21 tends to have a greater flow rate of cooling water. Therefore, the storage unit 21 that is located more downstream of the inflow pipe 30 tends to have more rapidly deteriorated ion exchange resin 60 stored in that storage unit 21. As a result, the storage unit 21 that stores more deteriorated ion exchange resin 60 tends to have a greater flow rate of cooling water, which may reduce the ion exchange efficiency of the ion exchanger 10.

[0073] In this regard, according to the above configuration, the inflow pipe 30 is provided with a first tapered portion 33 formed by the first tapered portion 86 and a second tapered portion 34 formed by the second tapered portion 87. The second tapered portion 34 is connected to the accommodation section 21B located furthest downstream in the flow direction via the inflow-side connecting portion 35. The degree of reduction in the flow path cross-sectional area of ​​the inflow pipe 30 is greater in the second tapered portion 34 than in the first tapered portion 33. Therefore, the flow rate of the cooling water flowing through the inflow pipe 30 is lower in the second tapered portion 34 than in the first tapered portion 33. This allows the flow rate of the cooling water flowing into the accommodation section 21B to be reduced compared to a case in which the inflow pipe 30 does not have the second tapered portion 34, for example, when the inflow pipe 30 has only the first tapered portion 33. For this reason, by adjusting the degree of reduction in the flow path cross-sectional area of ​​the inlet pipe 30 in the second tapered section 34, it becomes easier to equalize the flow rates of the cooling water flowing into the two storage sections 21. Therefore, it is possible to suppress a decrease in the ion exchange efficiency in the ion exchanger 10.

[0074] (4) The molding surface 82a of each first molding portion 82 extends along the outer peripheral surface of the second die 85 so that the thickness of the cavity 80a formed between the molding surface 82a and the outer peripheral surface of the second die 85 is constant. According to the above configuration, the thickness of the cavity 80a formed between the molding surface 82a of each first die 81 and the outer peripheral surface of the second die 85 is constant. That is, the thickness of the portion of the peripheral wall 31 of the inflow pipe 30 formed by each bottom wall 22 is constant. Therefore, the occurrence of sink marks due to variations in the thickness of the peripheral wall 31 of the inflow pipe 30 can be suppressed.

[0075] (5) In the molding step, two inlet-side communication portions 35 having the same shape and size of the internal space are molded. According to the above configuration, two inlet-side communicating sections 35 having the same shape and size of the internal space are formed. Therefore, the difference in the flow rate of the cooling water flowing from the inlet pipe 30 into the two storage sections 21 tends to depend on the degree of reduction in the flow path cross-sectional area of ​​the inlet pipe 30 in the second tapered section 34. This makes it easier to adjust the flow rate of the cooling water flowing into the two storage sections 21. Therefore, it is possible to suppress a decrease in the ion exchange efficiency in the ion exchanger 10.

[0076] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0077] In the molding step, two inlet-side communication portions 35 having different shapes and sizes of their internal spaces may be molded. The molding surface 82a of each first die 81 does not have to extend along the outer peripheral surface of the second die 85. In this case, the thickness of the portion of each bottom wall 22 that forms the peripheral wall 31 of the inlet pipe 30 does not have to be uniform.

[0078] The second die 85 does not have to have the second tapered portion 34, or does not have to have both the first tapered portion 33 and the second tapered portion 34. Even in this case, by fitting the second die 85 to each second molding portion 83, an effect equivalent to the above effect (1) can be achieved.

[0079] The first tapered portion 33 and the second tapered portion 34 do not have to be continuous. For example, another tapered portion may be provided between the first tapered portion 33 and the second tapered portion 34. Also, a straight portion extending linearly along the central axis of the inlet pipe 30 may be provided between the first tapered portion 33 and the second tapered portion 34. In these cases, a portion for forming the other tapered portion or straight portion is provided between the first tapered forming portion 86 and the second tapered forming portion 87 of the second mold 85.

[0080] The second molding portion 83 is not limited to having a fitting hole 83a or a fitting recess 83b, as long as the second mold 85 fits into it. For example, the second molding portion 83 may hold the second mold 85 by a groove into which the second mold 85 fits. Furthermore, the second molding portion 83 may hold the second mold 85 by a protrusion that fits into a recess formed in the second mold 85. This modification can also be applied to the second molding portion 84 in the same manner.

[0081] Both of the two second molded portions 83 may have the fitting holes 83a. Both of the two second molded portions 84 may have the fitting holes 84b. The second molding portion 83 may have a groove into which the second die 85 fits. The second molding portion 84 may have a groove into which the third die 88 fits.

[0082] The case 20 may include one storage section 21, an inlet pipe 30, and an outlet pipe 36. Even in this case, by injecting the resin R into the cavity 80a with the second mold 85 fitted to one second molding section 83 and the third mold 88 fitted to one second molding section 84, an effect equivalent to the above effect (1) can be achieved.

[0083] <Additional Notes> The above embodiment includes the configurations described in the following supplementary notes. [Appendix 1] A method for manufacturing an ion exchanger case, comprising: a storage section for storing ion exchange resin; and a piping that extends linearly and through which cooling water flows, the storage section having a bottom wall; and the piping having a communicating section that opens to the bottom wall and communicates the internal space of the piping with the internal space of the storage section in the radial direction of the piping, the method comprising: a molding step of integrally molding the storage section and the piping by injecting resin into a cavity formed in a mold including a first molding die that molds the inner surface of the storage section; and a cylindrical second molding die that molds the inner surface of the piping, the first molding die having a first molding section that molds the inner surface of the storage section and a second molding section that protrudes from the first molding section and molds the communicating section, the second molding section being configured to be able to hold the second molding section when fitted into it, and the molding step of injecting the resin into the cavity with the second molding die fitted into the second molding section.

[0084] [Appendix 2] A method for manufacturing an ion exchanger case, comprising a plurality of storage sections that store ion exchange resin and are arranged in parallel, and piping that extends linearly in the arranging direction of the plurality of storage sections and through which cooling water flows, each of the storage sections having a bottom wall, and the piping having a plurality of communication sections that open to each of the bottom walls and communicate with an internal space of the piping and an internal space of each of the storage sections in a radial direction of the piping, the method comprising: a first molding die that molds the inner surfaces of the plurality of storage sections, respectively; and a columnar second molding die that molds the inner surface of the piping. a molding step of integrally molding the plurality of storage sections and the piping by injecting resin into cavities formed in a first molding die, each of the first molding dies having a first molding portion that molds the inner surface of the storage section and a second molding portion that protrudes from the first molding portion and molds the communicating portion, each of the second molding portions being configured to be able to hold the second molding die when the second molding die is fitted into it, and in the molding step, the resin is injected into the cavities with the second molding die fitted into each of the second molding portions.

[0085] [Appendix 3] The method for manufacturing an ion exchanger case according to [Appendix 1] or [Appendix 2], wherein the second molding part has a fitting recess into which the tip of the second molding die fits. [Appendix 4] The method for manufacturing an ion exchanger casing according to [Appendix 2] or [Appendix 3], wherein the piping is an inlet pipe for introducing cooling water into the plurality of storage units, and the second molding die has a first tapered molding section whose cross-sectional area decreases toward a tip of the second molding die, and a second tapered molding section provided on the tip side of the first tapered molding section and whose cross-sectional area decreases toward the tip, the degree of decrease in the cross-sectional area of ​​the second tapered molding section being greater than the degree of decrease in the cross-sectional area of ​​the first tapered molding section, and when the flow direction of the cooling water flowing through the inlet pipe is simply defined as the flow direction, in the molding step, the second tapered molding section is fitted to the second molding section and the resin is injected into the cavity to form the communicating section that communicates the internal space of the portion of the inlet pipe that is formed by the second tapered molding section with the internal space of the storage unit that is furthest downstream in the flow direction among the plurality of storage units.

[0086] [Appendix 5] A method for manufacturing an ion exchanger case as described in [Appendix 4], wherein the internal space of the inlet pipe and the internal space of each of the storage sections are separated by each of the bottom walls, and the molding surface that molds the inner surface of the bottom wall in each of the first molding sections extends along the outer peripheral surface of the second molding mold so that the thickness of the cavity formed between the outer peripheral surface of the second molding mold and the molding surface is constant.

[0087] [Appendix 6] A method for manufacturing an ion exchanger case according to [Appendix 4] or [Appendix 5], wherein the molding step molds a plurality of the communication parts having the same shape and size of the internal space. [Explanation of symbols]

[0088] C…Cooling circuit R…Resin 10...Ion exchanger 20…case 21, 21A, 21B... Housing section 22...Bottom wall 23...peripheral wall 24...Protruding part 25...insertion slot 26...Female thread 27...Connection part 30…Inflow pipe 31...peripheral wall 32...First connection port 33...First tapered section 34...Second tapered section 35…Inflow side communication part 36...Outflow pipe 37...peripheral wall 38...Second connection port 39…Outflow side communication part 40...Cartridge 41...Cap 42...Top wall 43...peripheral wall 44...Male thread 45...Flow path member 46...Pipe section 47...Ring section 48...First support part 50...Cover member 51...Inner annular part 52...Outer annular part 53…Second support part 60...Ion exchange resin 71...1st seal ring 72...Second seal ring 73...Third seal ring 74...4th seal ring 80...Mold 80a...cavity 81…Type 1 82...First molding section 82a…molding surface 83…Second molding section 83a...Fitting hole 83b...Mating recess 84...Second molding section 84a...Mating recess 84b…Fitting hole 85…2nd type 86...First tapered forming section 87...Second tapered forming section 88…3rd type 89...4th type

Claims

1. A method for manufacturing an ion exchanger case, comprising: a storage section for storing ion exchange resin; and a pipe extending linearly and through which cooling water flows; the storage section having a bottom wall; and the pipe having a communication section that opens to the bottom wall and communicates an internal space of the pipe with an internal space of the storage section in a radial direction of the pipe, a molding step of integrally molding the storage portion and the piping by injecting a resin into a cavity formed in a mold including a first molding die that molds the inner surface of the storage portion and a columnar second molding die that molds the inner surface of the piping; the first molding die has a first molding portion that molds an inner surface of the accommodation portion, and a second molding portion that protrudes from the first molding portion and molds the communication portion, the second molding unit is configured to be able to hold the second molding die by fitting the second molding die thereto, In the molding step, the resin is injected into the cavity in a state where the second molding die is fitted into the second molding portion. A method for manufacturing a case for an ion exchanger.

2. A method for manufacturing an ion exchanger case comprising: a plurality of storage sections each storing an ion exchange resin and arranged in parallel; and piping extending linearly in the direction of arrangement of the plurality of storage sections and through which cooling water flows, each of the storage sections having a bottom wall; and the piping having a plurality of communication sections each opening into the bottom wall and communicating an internal space of the piping with an internal space of each of the storage sections in a radial direction of the piping, a molding step of integrally molding the plurality of storage sections and the piping by injecting resin into a cavity formed in a mold including a plurality of first molding dies that mold the inner surfaces of the plurality of storage sections, respectively, and a columnar second molding die that molds the inner surface of the piping; each of the first molding dies has a first molding portion that molds an inner surface of the accommodation portion and a second molding portion that protrudes from the first molding portion and molds the communication portion; each of the second molding parts is configured to be able to hold the second molding die by fitting the second molding die thereto; In the molding step, the resin is injected into the cavity in a state where the second molding die is fitted to each of the second molding portions. A method for manufacturing a case for an ion exchanger.

3. The second molding portion has a fitting recess into which a tip end portion of the second molding die fits. A method for manufacturing the ion exchanger case according to claim 1 or 2.

4. the piping is an inlet pipe for introducing cooling water into the plurality of accommodation sections, the second molding die has a first tapered molding portion whose cross-sectional area decreases toward a tip end of the second molding die, and a second tapered molding portion provided on the tip end side of the first tapered molding portion and whose cross-sectional area decreases toward the tip end, a degree of reduction in the cross-sectional area of ​​the second tapered portion is greater than a degree of reduction in the cross-sectional area of ​​the first tapered portion; When the flow direction of the cooling water flowing through the inlet pipe is simply defined as the flow direction, In the molding step, the resin is injected into the cavity with the second tapered molding portion fitted to the second molding portion, thereby molding the communication portion that communicates the internal space of the portion of the inlet pipe that is molded by the second tapered molding portion with the internal space of the storage portion that is furthest downstream in the flow direction among the plurality of storage portions. A method for manufacturing the ion exchanger case according to claim 2.

5. an internal space of the inlet pipe and an internal space of each of the storage portions are separated by each of the bottom walls; a molding surface for molding the inner surface of the bottom wall of each of the first molding portions extends along the outer peripheral surface of the second molding mold so that the thickness of the cavity formed between the first molding portion and the outer peripheral surface of the second molding mold is constant; A method for manufacturing the ion exchanger case according to claim 4.

6. In the molding step, a plurality of the communication parts having the same shape and size of the internal space are molded. A method for manufacturing the ion exchanger case according to claim 4 or 5.

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