Tube bundling method

Abstract

Controls deformation of the tube end. [Solution] The method includes an inner sleeve fitting step of fitting an inner sleeve 32 made of heat-fusible resin onto at least one of the ends of each of a plurality of tubes 2, an outer sleeve fitting step of fitting an outer sleeve 33 made of heat-shrinkable resin onto the end of a tube bundle 31 formed by bundling a plurality of tubes 2, a pin insertion step of inserting pins 34 into each end of the plurality of tubes 2, and a heating step of heating the end of the tube bundle 31 after the inner sleeve fitting step, outer sleeve fitting step, and pin insertion step to shrink the outer sleeve 33 and melt the inner sleeve 32.

Description

[Technical Field]

[0001] The present invention relates to a tube bundling method for bundling the ends of a plurality of tubes. [Background technology]

[0002] Patent Document 1 describes a method for bundling the ends of multiple fluororesin tubes. In this method, multiple fluororesin tubes, each with a heat-shrinkable tube made of a heat-flowable fluororesin fitted around its end, are bundled together, a fluororesin sleeve is fitted around the end of the bundle of fluororesin tubes, and the end is heated to a temperature above the melting point of the heat-shrinkable tube to melt and shrink the heat-shrinkable tube. The heat-flowable fluororesin of the heat-shrinkable tube is then cooled and solidified, bonding the fluororesin tube and the fluororesin sleeve together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 01-131392 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes that the heat-shrinkable tube shrinks when heated, thereby suppressing the expansion of the fluororesin tube due to heating and melting while preventing deformation of the fluororesin tube.

[0005] However, when the present inventors bundled the ends of multiple tubes using the method described in Patent Document 1, they discovered that, depending on the materials, heating temperature, and other conditions, the shrinkage of the heat-shrinkable tube or fluororesin sleeve would crush the ends of the fluororesin tubes, causing irregular deformation.

[0006] Therefore, one aspect of the present invention aims to provide a tube bundling method that can control deformation of the tube ends. [Means for solving the problem]

[0007] A tube bundling method according to one aspect of the present invention is a tube bundling method for bundling the ends of a plurality of tubes, and includes an inner sleeve fitting step of fitting an inner sleeve made of heat-fusible resin onto at least one of the ends of the plurality of tubes, an outer sleeve fitting step of fitting an outer sleeve made of heat-shrinkable resin onto the end of a tube bundle formed by bundling a plurality of tubes, a pin insertion step of inserting pins into the ends of each of the plurality of tubes, and a heating step of heating the end of the tube bundle after the inner sleeve fitting step, outer sleeve fitting step, and pin insertion step to shrink the outer sleeve and melt the inner sleeve.

[0008] In this tube bundling method, an inner sleeve is fitted over at least one of the ends of a plurality of tubes, an outer sleeve is fitted over the end of the tube bundle formed by bundling the plurality of tubes, and the end of the tube bundle is heated to shrink the outer sleeve and melt the inner sleeve, so that the ends of the plurality of tubes are gathered by the shrinking outer sleeve and bound together by the heat-melting resin of the inner sleeve. Then, a pin is inserted into each end of the plurality of tubes, and the end of the tube bundle is heated to shrink the outer sleeve and melt the inner sleeve. When the outer sleeve shrinks, the ends of the plurality of tubes abut against the pin and deform to match the outer shape of the pin. This allows for controlled deformation of the ends of the plurality of tubes.

[0009] The method may further include a pin removal step of removing the pins from the ends of the plurality of tubes after the heating step. In this tube bundling method, by removing the pins from the ends of the plurality of tubes, it is possible to pass a fluid such as a liquid or a gas through each of the bundled tubes.

[0010] In the pin removal step, the pins may be removed from the ends of the tubes after the molten heat-fusible resin of the inner sleeve has cooled and hardened. In this tube bundling method, by removing the pins from the ends of the tubes after the molten heat-fusible resin of the inner sleeve has cooled and hardened, deformation of the ends of the tubes due to the heat-fusible resin cooling and hardening can be suppressed.

[0011] In the pin inserting step, a pin longer than the inner sleeve and the outer sleeve may be inserted into each end of the plurality of tubes. In this tube bundling method, by inserting a pin longer than the inner sleeve and the outer sleeve into each end of the plurality of tubes, deformation of each end of the plurality of tubes when the outer sleeve shrinks can be appropriately controlled.

[0012] The outer diameter of the pin may be smaller than the inner diameter of each of the plurality of tubes. In this tube bundling method, by making the outer diameter of the pin smaller than the inner diameter of each of the plurality of tubes, the pin can be easily inserted into the ends of each of the plurality of tubes.

[0013] The outer diameter of the pin may be 96% to 99.9% of the inner diameter of each of the plurality of tubes. In this tube bundling method, by making the outer diameter of the pin 96% to 99.9% of the inner diameter of each of the plurality of tubes, it is possible to ensure ease of insertion of the pin into the ends of each of the plurality of tubes while suppressing deformation of each of the ends of the plurality of tubes when the outer sleeve shrinks.

[0014] The outer diameter of the pin may be 75% or more and less than 96% of the inner diameter of each of the multiple tubes. In this tube bundling method, by making the outer diameter of the pin 75% or more and less than 96% of the inner diameter of each of the multiple tubes, it is possible to create one or more protrusions at the end of each of the multiple tubes while ensuring internal space at the end of each of the multiple tubes. This allows the multiple tubes to be arranged closely together, thereby improving the bundling force of the multiple tubes.

[0015] The pins may be made of metal. In this tube bundling method, using metal pins can prevent the pins from breaking in the internal spaces of the tubes. This can prevent the negative effects of pin fragments being left in the internal spaces of the tubes. Furthermore, when the end of the tube bundle is heated, the inner sleeve can be heated and melted from the internal spaces of the tubes via the pins.

[0016] At least a portion of the pin may be coated with a release layer. In this tube bundling method, by coating at least a portion of the pin with a release layer, the pin can be easily removed from each end of the multiple tubes. Furthermore, by coating the pin with a release layer, even if gas is generated by heating the end of the tube bundle, corrosion of the pin due to the gas can be suppressed.

[0017] The release layer may be made of a fluororesin. In this tube bundling method, by using a release layer made of a fluororesin, it is possible to ensure ease of removal of the pins from the ends of the multiple tubes while suppressing the generation of residue in the internal space of each of the multiple tubes. Furthermore, by coating the pins with a fluororesin, even if gas is generated by heating the ends of the tube bundle, corrosion of the pins by the gas can be further suppressed.

[0018] The release layer may have one or more recesses. In this tube bundling method, forming one or more recesses in the release layer reduces the contact resistance between the ends of each of the multiple tubes and the pin. This makes it easier to remove the pin from the ends of each of the multiple tubes.

[0019] In the heating step, the heat-fusible resin of the molten inner sleeve may seal between the outer sleeve and the ends of the plurality of tubes and between the plurality of tubes. In this tube bundling method, the heat-fusible resin of the molten inner sleeve seals between the outer sleeve and the ends of the plurality of tubes and between the plurality of tubes, so that when a fluid such as a liquid or gas is supplied to the end faces of the bundled plurality of tubes, the fluid can be prevented from leaking between the plurality of tubes.

[0020] The heat-shrinkable resin of the outer sleeve may have a higher melting point than the heat-fusible resin of the inner sleeve, and in the heating step, the end of the tube bundle may be heated at a temperature higher than the melting point of the heat-fusible resin of the inner sleeve but lower than the melting point of the heat-shrinkable resin of the outer sleeve. In this tube bundling method, by heating the end of the tube bundle at a temperature higher than the melting point of the heat-fusible resin of the inner sleeve but lower than the melting point of the heat-shrinkable resin of the outer sleeve, the end of each of the multiple tubes can be bundled with the heat-fusible resin of the inner sleeve while properly maintaining the outer sleeve fitted over each end of the multiple tubes.

[0021] The inner sleeve fitting step may include a first inner sleeve fitting step of fitting a first inner sleeve, which is an inner sleeve, onto each end of the plurality of tubes. In this tube bundling method, by fitting the first inner sleeve, which is an inner sleeve, onto each end of the plurality of tubes, the heat-melting resin of the inner sleeve is disposed between the ends of the plurality of tubes, thereby preventing the ends of the plurality of tubes from abutting against each other.

[0022] The inner sleeve fitting step may include a second inner sleeve fitting step of dividing the plurality of tubes into a plurality of small bundles and fitting a second inner sleeve, which is an inner sleeve, onto the ends of the small bundles. In this tube bundling method, by dividing the plurality of tubes into a plurality of small bundles and fitting a second inner sleeve, which is an inner sleeve, onto the ends of the small bundles, the tubes can be easily bundled even when there are a large number of tubes, thereby improving workability. [Effects of the Invention]

[0023] According to one aspect of the present invention, deformation of the end of the tube can be controlled. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 2 is a schematic cross-sectional view showing an example of a degassing module. [Figure 2] FIG. 2 is a schematic perspective view showing an example of a tube unit. [Figure 3] FIG. 2 is a schematic end view showing an example of a tube unit. [Figure 4] FIG. 4 is a schematic cross-sectional view taken along line IV-IV shown in FIG. [Figure 5] 5(a), 5(b) and 5(c) are diagrams for explaining a tube bundling method. [Figure 6] 6(a), 6(b) and 6(c) are diagrams for explaining the tube bundling method. [Figure 7] 7(a), 7(b) and 7(c) are diagrams for explaining the tube bundling method. [Figure 8] 8(a), 8(b), and 8(c) are schematic cross-sectional views showing examples of metal rods. [Figure 9] FIG. 7 is a schematic cross-sectional view showing the state of FIG. 6(c). [Figure 10] FIG. 7(b) is a schematic cross-sectional view showing the state of FIG. 7(a). [Figure 11] FIG. 11(a) is an example of a schematic cross-sectional view taken along line XI-XI shown in FIG. 10, and FIG. 11(b) is a partially enlarged view of FIG. 11(a). [Figure 12] FIG. 12(a) is an example of a schematic cross-sectional view taken along line XI-XI shown in FIG. 10, and FIG. 12(b) is a partially enlarged view of FIG. 12(a). [Figure 13] 13(a), 13(b) and 13(c) are diagrams showing the relationship between a plurality of tubes, an inner sleeve and an outer sleeve. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, a tube bundling method according to an embodiment will be described in detail with reference to the drawings. In this embodiment, the tube bundling method of the present invention is applied to a method for bundling multiple tubes when manufacturing a tube unit used in a degassing module that degasses a liquid. In all drawings, the same or corresponding parts are designated by the same reference numerals, and duplicate explanations will be omitted.

[0026] FIG. 1 is a schematic cross-sectional view showing an example of a degassing module. As shown in FIG. 1, the degassing module 1 includes a tube unit 3 in which a plurality of tubes 2 are bundled at both ends, and a housing 4 that accommodates the tube unit 3. The degassing module 1 has the housing 4 divided by the plurality of tubes 2 into a first region, which is the internal space 2A of each of the plurality of tubes 2 (see FIG. 4), and a second region, which is a space 4A outside the plurality of tubes 2. The first region is a region to which liquid is supplied, and the second region is a region to which air is sucked. The degassing module 1 degasses the liquid by supplying the liquid to the internal space 2A of each of the plurality of tubes 2 (first region) and sucking air from the space 4A outside the plurality of tubes 2 (second region).

[0027] The tube 2 is a tubular membrane that is permeable to gas but not to liquid. The material, membrane shape, membrane form, etc. of the tube 2 are not particularly limited. Examples of materials for the tube 2 include polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ethylene copolymer resin) (ETFE), polychlorotrifluoroethylene (PCTFE), amorphous fluoropolymer (non-crystalline fluorine resin; AF), fluororesins such as polyvinylidene fluoride (PVDF), polypropylene (PP), polymethylpentene (PMP), silicone, polyimide, and polyamide. Examples of amorphous fluoropolymers include Teflon (registered trademark) AF.

[0028] FIG. 2 is a schematic perspective view showing an example of a tube unit, and FIG. 3 is a schematic end view showing an example of a tube unit. FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 3. Note that, in the drawings, as an example, the tube unit 3 is illustrated as being composed of seven tubes 2, but the number of tubes 2 is not particularly limited. As shown in FIGS. 2 to 4, the tube unit 3 is composed by bundling both ends of a plurality of tubes 2. That is, the tube unit 3 includes a plurality of tubes 2 and a pair of bundling parts 5, 5 that respectively bundling one end and the other end of the plurality of tubes 2. Note that the pair of bundling parts 5, 5 are also attached to the housing 4. Note that, since the pair of bundling parts 5, 5 have the same configuration, the following description will be given by representing one bundling part 5. However, the pair of bundling parts 5, 5 may have different configurations.

[0029] The bundling portion 5 includes an outer tube 6 fitted onto the end portions of each of the plurality of tubes 2, and a sealing portion 7 filled between the outer tube 6 and the end portions of each of the plurality of tubes 2.

[0030] The outer cylinder 6 is formed in a substantially cylindrical shape and forms the outermost layer of the binding part 5. The outer cylinder 6 is attached to the housing 4.

[0031] The sealing portion 7 is filled between the ends of the multiple tubes 2 and the outer casing 6, bundling the ends of the multiple tubes 2 and sealing the gap between the ends of the multiple tubes 2 and the outer casing 6. In other words, the sealing portion 7 is not filled in the internal space 2A of each of the multiple tubes 2, but is filled between the multiple tubes 2 and between the multiple tubes 2 and the outer casing 6 (see FIG. 3). Therefore, only the internal space 2A of each of the multiple tubes 2 is open from the end face of the sealing portion 7.

[0032] As shown in FIG. 1, the housing 4 includes a housing body 11, a cover portion 12, a first connector 13, and a second connector .

[0033] The housing body 11 is a portion in which the tube unit 3 is housed. The housing body 11 is a cylindrical container having an opening on one end face. The lid part 12 is a lid that is airtightly joined to the housing body 11 and closes the opening of the housing body 11. The lid part 12 can be joined to the housing body 11 by, for example, welding, screwing, fitting, etc. If there are no manufacturing problems, the housing 4 may not be divided into the housing body 11 and the lid part 12, but may be formed integrally.

[0034] A first connector 13 and a second connector 14 are airtightly joined to the lid portion 12. A first opening 15 that penetrates the inside and outside of the lid portion 12 (housing 4) is formed in the first connector 13, and a second opening 16 that penetrates the inside and outside of the lid portion 12 (housing 4) is formed in the second connector 14. The first connector 13 and the second connector 14 can be joined to the lid portion 12 by, for example, welding, screwing, fitting, etc.

[0035] The first connector 13 is airtightly joined to one bundling portion 5 of the tube unit 3, and airtightly connects the one bundling portion 5 of the tube unit 3 and the housing 4. The first connector 13 is formed, for example, in a stepped cylindrical shape and is disposed between the one bundling portion 5 of the tube unit 3 and the housing 4. A first pipe 18 that communicates with each internal space 2A of the multiple tubes 2 is joined to the first connector 13. The first connector 13 can be joined to the one bundling portion 5 of the tube unit 3 by, for example, welding, screwing, fitting, etc. The first connector 13 can be joined to the first pipe 18 by, for example, welding, screwing, fitting, etc.

[0036] The second connector 14 is airtightly joined to the other bundling portion 5 of the tube unit 3, and airtightly connects the other bundling portion 5 of the tube unit 3 to the housing. The second connector 14 is formed, for example, in a stepped cylindrical shape and is disposed between the other bundling portion 5 of the tube unit 3 and the housing 4. A second pipe 19 that communicates with each internal space 2A of the multiple tubes 2 is joined to the second connector 14. The second connector 14 can be joined to the other bundling portion 5 of the tube unit 3 by, for example, welding, screwing, fitting, etc. The second connector 14 can also be joined to the second pipe 19 by, for example, welding, screwing, fitting, etc.

[0037] An air intake port 20 is formed in the housing body 11. The air intake port 20 is an opening formed in the housing body 11 for drawing air from a space 4A outside the plurality of tubes 2 inside the housing 4. A third pipe 21 that communicates with the space 4A outside the plurality of tubes 2 inside the housing 4 is joined to the air intake port 20. Therefore, by connecting a suction pump (not shown) to the third pipe 21 and drawing air through the air intake port 20 using the suction pump, the pressure in the space 4A outside the plurality of tubes 2 inside the housing 4 can be reduced. The third pipe 21 can be joined to the air intake port 20 by, for example, welding, screwing, fitting, or the like.

[0038] When degassing a liquid using the degassing module 1 configured as described above, the suction pump connected to the third tube 21 suctions the space 4A outside the plurality of tubes 2 in the housing 4, while supplying the liquid to the first tube 18 and discharging the liquid from the second tube 19. The liquid supplied to the first tube 18 is then supplied to the internal spaces 2A of the plurality of tubes 2 via the first connector 13. At this time, the space 4A outside the plurality of tubes 2 in the housing 4 is in a depressurized state. Therefore, as the liquid passes through the internal spaces 2A of the plurality of tubes 2, dissolved gas and air bubbles in the liquid permeate each of the plurality of tubes 2 and are drawn into the space 4A outside the plurality of tubes 2 in the housing 4. This degassing of the liquid is then performed. The degassed liquid is then discharged to the second tube 19 via the second connector 14. Alternatively, the liquid may be supplied from the second tube 19 and discharged from the first tube 18.

[0039] The liquid to be degassed is not particularly limited, but examples thereof include organic solvents and water.

[0040] Next, a tube bundling method for bundling the ends of a plurality of tubes 2 will be described.

[0041] This tube bundling method includes an inner sleeve fitting step, an outer sleeve fitting step, a pin insertion step, a heating step, and a pin removal step. In the following description, the steps are performed in the order of the inner sleeve fitting step, the outer sleeve fitting step, the pin insertion step, the heating step, and the pin removal step, but the inner sleeve fitting step, the outer sleeve fitting step, and the pin insertion step may be performed in any order.

[0042] As shown in Figures 5(a) and 5(b), in the inner sleeve fitting step, an inner sleeve 32 made of a heat-fusible resin is fitted onto each end of the plurality of tubes 2. The number of the plurality of tubes 2 onto which the inner sleeve 32 is fitted is the number of tubes 2 constituting the tube unit 3. In this case, workability can be improved by bundling the plurality of tubes 2 into a tube bundle 31 and then fitting the inner sleeve 32 onto each end of the plurality of tubes 2. The tube bundle 31 may be formed by bundling the plurality of tubes 2 with a work tape such as a fluororesin tape.

[0043] The inner sleeve 32 becomes the sealing portion 7 by being heated and melted. The heat-melting resin forming the inner sleeve 32 is a resin that melts and becomes fluid when heated above its melting point. This heat-melting resin is preferably a resin that shrinks when heated close to its melting point and melts when heated above its melting point. The melting point of this heat-melting resin is preferably lower than the melting points of the multiple tubes 2 and is also preferably lower than the decomposition temperature of the multiple tubes 2. Examples of this heat-melting resin include fluororesins such as FEP and PFA. The inner diameter of the inner sleeve 32 is equal to or larger than the outer diameter of each of the multiple tubes 2, and is preferably larger than the outer diameter of each of the multiple tubes 2.

[0044] In the inner sleeve fitting step, after fitting the inner sleeve 32 onto the ends of each of the multiple tubes 2, the inner sleeve 32 is heated and shrunk as shown in FIG. 5( c), thereby temporarily fixing the inner sleeve 32 to the ends of each of the multiple tubes 2. The heating temperature for temporarily fixing the inner sleeve 32 is equal to or lower than the melting point of the inner sleeve 32, and preferably lower than the melting point of the inner sleeve 32. This makes it possible to prevent the inner sleeve 32 from falling off the ends of each of the multiple tubes 2. However, if falling off of the inner sleeve 32 is not an issue, it is not necessary to heat-shrink the inner sleeve 32 to temporarily fix it.

[0045] As shown in FIG. 6(a), in the outer sleeve fitting step, an outer sleeve 33 made of heat-shrinkable resin is fitted onto the end of a tube bundle 31 formed by bundling a plurality of tubes 2 together.

[0046] The outer sleeve 33 is heat-shrunk to become the outer tube 6. The heat-shrinkable resin forming the outer sleeve 33 is a resin that shrinks when heated to near its melting point and melts and becomes fluid when heated above its melting point. The melting point of this heat-shrinkable resin is higher than the melting point of the heat-fusible resin forming the inner sleeve 32. The melting point of this heat-shrinkable resin is preferably lower than the melting point of the multiple tubes 2 and also lower than the decomposition temperature of the multiple tubes 2. Examples of this heat-shrinkable resin include fluororesins such as PFA and PTFE. The inner diameter of the outer sleeve 33 is equal to or greater than the outer diameter of the tube bundle 31, and is preferably larger than the outer diameter of the tube bundle 31.

[0047] 6(b), 6(c), and 9, in the pin insertion step, pins 34 are inserted into the ends of the plurality of tubes 2 constituting the tube bundle 31. At this time, it is preferable that the pins 34 inserted into the ends of the plurality of tubes 2 are longer than the inner sleeve 32 and the outer sleeve 33.

[0048] The pin 34 is a member for controlling deformation of the ends of each of the multiple tubes 2 when the inner sleeve 32 and the outer sleeve 33 are contracted. The pin 34 is formed in a long, thin rod shape. From the viewpoint of making it easy to insert the pin 34 into the ends of each of the multiple tubes 2, it is preferable that the outer diameter of the pin 34 be smaller than the inner diameter of each of the multiple tubes 2.

[0049] The material of the pin 34 is not particularly limited, but is preferably a material that is corrosion-resistant, flexible, and resilient. In particular, if gas is generated by heating the ends of the multiple tubes 2, the material is preferably corrosion-resistant to this gas. Examples of materials for the pin 34 include metals that can be used as spring materials, such as SUS304 and SUS316. However, the material for the pin 34 does not have to be a spring material.

[0050] The pin 34 may be, for example, as shown in Fig. 8(a), constituted only by a metal pin body 35, or as shown in Figs. 8(b) and 8(c), the surface of the pin body 35 may be coated with a release layer 36. The release layer 36 is a layer that makes it easier to remove the pin 34 from the respective ends of the multiple tubes 2 when the inner sleeve 32 and the outer sleeve 33 are contracted. The material of the release layer 36 is not particularly limited, and examples include fluororesins such as PTFE.

[0051] It is preferable that the release layer 36 covers at least the portions of the pin bodies 35 that are inserted into the respective ends of the multiple tubes 2. In this case, the surface of the release layer 36 may be formed to be smooth overall, as shown in Fig. 8(b), or one or more recesses 37 may be formed on the surface of the release layer 36, as shown in Fig. 8(c). The recesses 37 may be recesses 37A that do not expose the pin bodies 35, or recesses 37B that expose the pin bodies 35.

[0052] In the heating step, the end of the tube bundle 31 is heated to shrink the outer sleeve 33 and melt the inner sleeve 32. In the heating step, the end of the tube bundle 31 is heated at a temperature higher than the melting point of the heat-fusible resin of the inner sleeve 32 but lower than the melting point of the heat-shrinkable resin of the outer sleeve 33. As a result, as shown in FIGS. 7( a) and 10, the outer sleeve 33 shrinks, narrowing the gap between the outer sleeve 33 and the multiple tubes 2 and narrowing the gap between the multiple tubes 2. Furthermore, the heat-fusible resin of the inner sleeve 32 melts and flows, sealing the gap between the outer sleeve 33 and the multiple tubes 2 and between the multiple tubes 2. At this time, by adjusting the thickness of the inner sleeve 32, the gap between the outer sleeve 33 and the multiple tubes 2 and the gap between the multiple tubes 2 can be appropriately sealed. In other words, if the area between these gaps is large, the thickness of the inner sleeve 32 should be increased. Furthermore, if the amount of heat-fusible resin in the inner sleeve 32 alone is insufficient to seal the gap, the gap can be sealed by arranging multiple inner sleeves 32 or by arranging additional members made of the same heat-fusible resin as the inner sleeve 32.

[0053] At this time, the outer sleeve 33 attempts to crush the ends of the multiple tubes 2 as it shrinks, but the ends of the multiple tubes 2 are deformed to match the outer shape of the pin 34 as they abut against the pin 34. For example, by changing the outer diameter of the pin 34 relative to the inner diameter of the multiple tubes 2, it is possible to shrink the ends of the multiple tubes 2 into a roughly circular shape that matches the outer shape of the pin 34, as shown in Figures 11(a) and 11(b), or to shrink the ends of the multiple tubes 2 by creating one or more protrusions 2B at each end, as shown in Figures 12(a) and 12(b).

[0054] Specifically, by setting the outer diameter of the pin 34 to 96% or more and 99.9% or less of the inner diameter of each of the plurality of tubes 2, it is possible to ensure ease of insertion of the pin 34 into each end of the plurality of tubes 2 while suppressing deformation of each end of the plurality of tubes 2 when the inner sleeve 32 and the outer sleeve 33 are contracted. In other words, by setting the outer diameter of the pin 34 to 99.9% or less of the inner diameter of each of the plurality of tubes 2, it is possible to ensure ease of insertion of the pin 34 into each end of the plurality of tubes 2. On the other hand, by setting the outer diameter of the pin 34 to 96% or more of the inner diameter of each of the plurality of tubes 2, it is possible to suppress sagging (loosening) of each end of the plurality of tubes 2 when the inner sleeve 32 and the outer sleeve 33 are contracted, thereby suppressing deformation of each end of the plurality of tubes 2. As a result, as shown in FIGS. 11( a) and 11(b), it is possible to form the end of each of the plurality of tubes 2 into a substantially circular shape that matches the outer shape of the pin 34.

[0055] On the other hand, by setting the outer diameter of the pin 34 to 75% or more and less than 96% of the inner diameter of each of the multiple tubes 2, it is possible to create one or more protrusions 2B at each end of the multiple tubes 2 while ensuring an internal space 2A at each end of the multiple tubes 2. In other words, by setting the outer diameter of the pin 34 to 75% or more of the inner diameter of each of the multiple tubes 2, it is possible to ensure an internal space 2A at each end of the multiple tubes 2. On the other hand, by setting the outer diameter of the pin 34 to less than 96% of the inner diameter of each of the multiple tubes 2, it is possible to actively make the ends of the multiple tubes 2 sag when the inner sleeve 32 and the outer sleeve 33 contract, thereby forming a cylindrical portion that extends cylindrically in the extension direction of the tube 2 and a protrusion that protrudes radially outward from this cylindrical portion at each end of the multiple tubes 2. The protrusions are formed by the sagging portions at the ends of the multiple tubes 2.

[0056] In order to prevent the outer sleeve 33 from falling off from the tube bundle 31, the outer sleeve 33 may be heated and slightly shrunk before the heating step to temporarily fix the outer sleeve 33 to the tube bundle 31. In this case, the heating temperature of the outer sleeve 33 is preferably equal to or lower than the melting point of the outer sleeve 33. However, if falling off of the outer sleeve 33 is not an issue, it is not necessary to heat-shrink the outer sleeve 33 to temporarily fix it.

[0057] 7(b) and 7(c), in the pin removal step, the pins 34 are removed from the respective ends of the plurality of tubes 2. In the pin removal step, the pins 34 may be removed from the respective ends of the plurality of tubes 2 before the molten heat-fusible resin of the inner sleeve 32 cools and hardens, but from the viewpoint of suppressing deformation of the respective ends of the plurality of tubes due to the cooling and hardening of the heat-fusible resin, it is preferable to remove the pins 34 after the molten heat-fusible resin of the inner sleeve 32 cools and hardens.

[0058] Then, the molten heat-fusible resin of the inner sleeve 32 cools and hardens, and all the pins 34 are removed, completing the tube unit 3 in which the ends of the plurality of tubes 2 are bound together.

[0059] As described above, in the tube bundling method according to this embodiment, an inner sleeve 32 is fitted onto each end of a plurality of tubes 2, an outer sleeve 33 is fitted onto the end of a tube bundle 31 formed by bundling the plurality of tubes 2, and the end of the tube bundle 31 is heated to shrink the outer sleeve 33 and melt the inner sleeve 32, so that the ends of the plurality of tubes 2 are gathered by the shrinking outer sleeve 33 and bound together by the heat-melting resin of the inner sleeve 32. Then, pins 34 are inserted into each end of the plurality of tubes 2, and the end of the tube bundle 31 is heated to shrink the outer sleeve 33 and melt the inner sleeve 32. Therefore, when the outer sleeve 33 shrinks, the ends of the plurality of tubes 2 abut against the pins 34 and deform to match the outer shape of the pins 34. This allows for controlled deformation of the ends of the plurality of tubes 2.

[0060] Then, by removing the pins 34 from the ends of each of the plurality of tubes 2, it is possible to allow fluids such as liquids and gases to flow through each of the plurality of bundled tubes 2.

[0061] In addition, by removing the pins 34 from the ends of each of the multiple tubes 2 after the molten heat-fusible resin of the inner sleeve 32 has cooled and hardened, it is possible to prevent the ends of each of the multiple tubes 2 from deforming as the heat-fusible resin cools and hardens.

[0062] Furthermore, by inserting pins 34 that are longer than the inner sleeve 32 and the outer sleeve 33 into the ends of each of the multiple tubes 2, deformation of the ends of each of the multiple tubes 2 when the outer sleeve 33 contracts can be appropriately controlled.

[0063] Furthermore, by making the outer diameter of the pin 34 smaller than the inner diameter of each of the plurality of tubes 2, the pin 34 can be easily inserted into the end portions of each of the plurality of tubes 2.

[0064] Furthermore, by making the outer diameter of the pin 96% or more and 99.9% or less of the inner diameter of each of the multiple tubes 2, it is possible to ensure ease of insertion of the pin 34 into the ends of each of the multiple tubes 2 while suppressing deformation of the ends of each of the multiple tubes 2 when the outer sleeve 33 shrinks.

[0065] On the other hand, by making the outer diameter of the pin 75% or more and less than 96% of the inner diameter of each of the multiple tubes, it is possible to create one or more protrusions 2B at each end of the multiple tubes 2 while ensuring an internal space 2A at each end of the multiple tubes 2. This allows the multiple tubes 2 to be arranged closely together, thereby improving the binding force of the multiple tubes 2.

[0066] Furthermore, by making the pins 34 out of metal, it is possible to prevent the pins 34 from breaking in the internal spaces 2A of the multiple tubes 2. This prevents the negative effects caused by fragments of the pins 34 being left in the internal spaces 2A of the multiple tubes 2. Furthermore, when the end of the tube bundle 31 is heated, the inner sleeve 32 can be heated and melted from the internal spaces 2A of the multiple tubes 2 via the pins 34.

[0067] Furthermore, by covering at least a portion of the pin 34 with the release layer 36, the pin 34 can be easily removed from each end of the multiple tubes 2. Moreover, by covering the pin 34 with the release layer 36, even if gas is generated by heating the end of the tube bundle 31, corrosion of the pin 34 due to the gas can be suppressed.

[0068] Furthermore, by making the release layer 36 from a fluororesin, it is possible to ensure ease of removal of the pins 34 from the ends of the plurality of tubes 2, while also preventing residue from being generated in the internal spaces 2A of the plurality of tubes 2. Moreover, by covering the pins 34 with a fluororesin, even if gas is generated by heating the ends of the tube bundle 31, corrosion of the pins due to the gas can be further prevented.

[0069] Furthermore, by forming one or more recesses 37 in the release layer 36, the contact resistance between the pin 34 and each end of the plurality of tubes 2 is reduced. This makes it possible to more easily remove the pin 34 from each end of the plurality of tubes 2.

[0070] Furthermore, the heat-melting resin of the molten inner sleeve 32 seals the gap between the outer sleeve 33 and the ends of the plurality of tubes 2 and the gap between the plurality of tubes 2, so that when a fluid such as a liquid or gas is supplied to the end faces of the bundled plurality of tubes 2, the fluid can be prevented from leaking between the plurality of tubes 2. In other words, in the degassing module 1, when a liquid is supplied to the first pipe 18, the liquid is supplied only to the internal spaces 2A of the plurality of tubes 2, and can be prevented from leaking into the space 4A outside the plurality of tubes 2 within the housing 4.

[0071] Furthermore, by heating the ends of the tube bundle 31 at a temperature higher than the melting point of the heat-fusible resin of the inner sleeve 32 and lower than the melting point of the heat-shrinkable resin of the outer sleeve 33, the ends of the multiple tubes 2 can be bundled together with the heat-fusible resin of the inner sleeve 32 while maintaining the outer sleeve 33 properly fitted onto each end of the multiple tubes 2.

[0072] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

[0073] For example, in the above embodiment, the number of tubes constituting the tube unit is described as seven, but the number of tubes constituting the tube unit is not particularly limited and may be, for example, several tens or several hundreds.

[0074] In addition, in the above embodiment, the inner sleeve 32 is described as being fitted onto the end of each of the multiple tubes 2, but the inner sleeve 32 may also be fitted onto at least one of the ends of each of the multiple tubes 2.

[0075] 13(a), only the first inner sleeve fitting step of fitting a first inner sleeve 32A, which is an inner sleeve 32, onto the ends of each of the plurality of tubes 2 may be performed, or as shown in FIG. 13(b), both this first inner sleeve fitting step and a second inner sleeve fitting step of dividing the plurality of tubes 2 into a plurality of small bundles and fitting a second inner sleeve 32B, which is an inner sleeve 32, onto the ends of the small bundles may be performed, or as shown in FIG. 13(c), only the second sleeve fitting step may be performed. The inner sleeve fitting step shown in FIG. 13(a) is the same as the inner sleeve fitting step in the above embodiment.

[0076] As shown in the first inner sleeve fitting step in Figures 13(a) and 13(b), by fitting the first inner sleeve 32A, which is the inner sleeve 32, onto each end of the multiple tubes 2, the heat-melting resin of the inner sleeve 32 is placed between each end of the multiple tubes 2, thereby preventing the ends of the multiple tubes 2 from abutting against each other.

[0077] As shown in the second inner sleeve fitting step in Figures 13(b) and 13(c), by dividing multiple tubes 2 into multiple small bundles and fitting the second inner sleeve 32B, which is an inner sleeve 32, onto the ends of the small bundles, it becomes easier to bundle the tubes 2 when there are a large number of tubes 2, thereby improving workability.

[0078] Furthermore, when the tube bundling method of the present invention is not applied to the manufacture of the tube unit of the above-mentioned degassing module, that is, when applied to other tube units, etc., it is not necessarily necessary to seal between the outer sleeve and the ends of the multiple tubes, and between the multiple tubes, with the heat-melting resin of the molten inner sleeve. [Explanation of symbols]

[0079] 1...degassing module, 2...tube, 2A...internal space, 2B...protrusion, 3...tube unit, 4...housing, 4A...space, 5...binding portion, 6...outer tube, 7...sealing portion, 12...lid portion, 13...first connector, 14...second connector, 15...first opening, 16...second opening, 18...first tube, 19...second tube, 20...intake port, 21...third tube, 31...tube bundle, 32...inner sleeve, 32A...first inner sleeve, 32B...second inner sleeve, 33...outer sleeve, 34...pin, 35...pin body, 36...release layer, 37...recess.

Claims

1. A tube bundling method for bundling ends of a plurality of tubes, comprising: an inner sleeve fitting step of fitting an inner sleeve made of a heat-meltable resin onto at least one of the ends of each of the plurality of tubes; an outer sleeve fitting step of fitting an outer sleeve made of heat-shrinkable resin onto an end of the tube bundle obtained by bundling the plurality of tubes; a pin insertion step of inserting a pin into each end of the plurality of tubes; a heating step of heating the end of the tube bundle after the inner sleeve fitting step, the outer sleeve fitting step, and the pin insertion step, to shrink the outer sleeve and melt the inner sleeve. Tube bundling method.

2. The method further includes a pin removal step of removing the pins from the ends of each of the plurality of tubes after the heating step. The tube bundling method according to claim 1.

3. In the pin removal step, the pins are removed from the ends of the tubes after the molten heat-fusible resin of the inner sleeve has cooled and hardened. The tube bundling method according to claim 2.

4. In the pin inserting step, a pin having a length greater than that of the inner sleeve and the outer sleeve is inserted into each end of the plurality of tubes. The tube bundling method according to claim 1.

5. The outer diameter of the pin is smaller than the inner diameter of each of the plurality of tubes. The tube bundling method according to claim 1.

6. an outer diameter of the pin that is 96% or more and 99.9% or less of the inner diameter of each of the plurality of tubes; The tube bundling method according to claim 1.

7. an outer diameter of the pin that is equal to or greater than 75% and less than 96% of the inner diameter of each of the plurality of tubes; The tube bundling method according to claim 1.

8. The pin is made of metal. The tube bundling method according to claim 1.

9. At least a portion of the pin is coated with a release layer. The tube bundling method according to claim 1.

10. The release layer is made of a fluororesin. The tube bundling method according to claim 9.

11. The release layer has one or more recesses. The tube bundling method according to claim 9 or 10.

12. In the heating step, the heat-melting resin of the molten inner sleeve seals the gaps between the outer sleeve and the ends of the plurality of tubes and the gaps between the plurality of tubes. The tube bundling method according to claim 1.

13. the heat-shrinkable resin of the outer sleeve has a melting point higher than that of the heat-melt resin of the inner sleeve, In the heating step, the end of the tube bundle is heated at a temperature higher than the melting point of the heat-fusible resin of the inner sleeve and lower than the melting point of the heat-shrinkable resin of the outer sleeve. The tube bundling method according to claim 1.

14. The inner sleeve external fitting step includes a first inner sleeve external fitting step of externally fitting a first inner sleeve, which is the inner sleeve, onto each end of the plurality of tubes. The tube bundling method according to claim 1.

15. The inner sleeve fitting step includes a second inner sleeve fitting step of dividing the plurality of tubes into a plurality of small bundles and fitting a second inner sleeve, which is the inner sleeve, onto ends of the small bundles.

15. The tube bundling method according to claim 13 or 14.

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