Manufacturing method of resin tube with connector

Abstract

The manufacturing method of the resin tube (1) with connector includes: an inserting process (S3), in which the ends (21A, 21B) of the resin tube blank (5) having a straight tube portion (24) are inserted into the ends (31, 41) of the cylindrical connector (3, 4); a joining process (S4), in which the ends (21A, 21B) of the inserted resin tube blank (5) are joined to the ends (31, 41) of the connector (3, 4) by laser welding; a heating and holding process (S5), in which a posture holding mold (7) having a bending processing part (71) for bending the straight tube portion (24) is used to hold the straight tube portion (24) in a heated and bent state by the bending processing part (71) of the posture holding mold (7); and a cooling process (S6), in which the straight tube portion (24) is cooled.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a resin tube with a connector. Background Technology

[0002] For example, it is known that long, narrow resin tubes (also called hoses) are used in the fuel supply path of motor vehicles and in paths for the flow of other fluids. Furthermore, in order to connect these resin tubes to other components, connectors for connecting to other components are installed at the ends of the resin tubes.

[0003] For example, Patent Document 1 describes inserting a resin tube into a connector and irradiating it with a laser to join the resin tube and the connector by laser welding. Furthermore, as described in Patent Document 2, the resin tube is generally shaped with a curved portion due to its layout.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 4161823;

[0007] Patent Document 2: Japanese Patent No. 6710058. Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] In methods where a connector is joined to the end of a resin tube by laser welding after a bend is formed, the laser welding equipment becomes larger. For example, in cases where laser welding is performed around the entire circumference of the object, the object being welded is rotated while being irradiated with a laser. Therefore, due to the presence of the bend in the resin tube, the radius of rotation of the resin tube increases. Consequently, the laser welding equipment becomes larger.

[0010] Furthermore, in laser welding equipment, the resin tube needs to be supported during laser welding. To support the resin tube with its bends, a support fixture is positioned to match the bend shape of the resin tube. Therefore, if the shape of the resin tube to be welded changes, the support fixture needs to be changed or adjusted, requiring a significant amount of time.

[0011] The present invention was made in view of the above background, and its object is to provide a method for manufacturing a resin tube with a connector, which enables miniaturization of laser welding equipment and reduces the changeover adjustments of support fixtures in laser welding equipment.

[0012] means for solving problems

[0013] One aspect of the present invention is a method for manufacturing a resin tube with a connector, the resin tube having a bend, wherein...

[0014] The method for manufacturing the resin tube with connector includes:

[0015] The fitting process involves fitting the end of a resin tube blank having a straight section into the end of a cylindrical connector.

[0016] The joining process involves joining the end of the embedded resin tube blank to the end of the connector by laser welding.

[0017] In a heat-holding process, a posture-holding mold having a bending section for bending the straight tube section is used to hold the straight tube section in a heated and bent state using the bending section of the posture-holding mold; and

[0018] The cooling process involves cooling the straight pipe section.

[0019] Invention Effects

[0020] In the process of fitting the end of the resin tube blank to the end of the cylindrical connector, the resin tube blank is formed into a state with a straight tube portion. Furthermore, while the resin tube blank has a straight tube portion, the end of the resin tube blank and the end of the connector are joined by laser welding. Subsequently, in a heat-holding process, the straight tube portion of the resin tube blank is bent using a posture-holding die.

[0021] That is, while the resin tube blank has a straight section, it is joined to the connector by laser welding. Then, the resin tube blank is bent during a heat-holding process. Therefore, during laser welding, the resin tube blank in its state before bending is supported. In other words, when laser welding is performed while rotating the object to be welded, the rotation radius of the resin tube blank before bending is very small compared to the final formed part after bending. Therefore, by performing laser welding on the resin tube blank before bending and the connector, the laser welding equipment can be miniaturized.

[0022] Furthermore, during laser welding, the resin tube blank, before bending, is supported by a support fixture in the laser welding equipment. The straight portion of the resin tube blank can be supported by the support fixture. Even for resin tube blanks of different shapes that constitute the resin tube portion of the connector-equipped resin tube as the final formed part, the straight portion of each resin tube blank before bending can be supported during laser welding. Therefore, sometimes it is not necessary to changeover adjustments to the support fixture in the laser welding equipment. Even if changeover adjustments are required, they can be completed with less time. Thus, the time required for changeover adjustments to the support fixture can be reduced.

[0023] As described above, the support fixture supports the resin tube blank in its state before bending. By configuring it in this way, compared to the case where the support fixture supports only a portion of the resin tube after bending, the space required to secure the support fixture in the laser welding equipment can be reduced. Therefore, miniaturization of the laser welding equipment becomes possible.

[0024] It should be noted that the reference numerals in parentheses in the claims indicate the correspondence between the specific means described in the embodiments described below, and are not intended to limit the technical scope of the present invention. Attached Figure Description

[0025] Figure 1 This is a diagram showing the final form of the resin tube with connector, which is the object of the manufacturing method of the first embodiment.

[0026] Figure 2 This is a flowchart illustrating the manufacturing method of the first embodiment.

[0027] Figure 3 It means Figure 2 A diagram of the mounting process.

[0028] Figure 4 yes Figure 3 An enlarged sectional view of part A.

[0029] Figure 5 Is Figure 2 A top view of the equipment used in the first joining process.

[0030] Figure 6 Is Figure 2 A top view of the equipment used in the second joining process.

[0031] Figure 7 It means in Figure 2 A perspective view of the posture-holding mold used in the heating and holding process.

[0032] Figure 8This is a flowchart illustrating the manufacturing method of the second embodiment.

[0033] Figure 9 Is Figure 8 A top view of the equipment used in the joining process.

[0034] Figure 10 This is a flowchart illustrating the manufacturing method of the third embodiment.

[0035] Figure 11 This is a diagram showing the final form of the resin tube with connector, which is the object of the manufacturing method of the fourth embodiment. Detailed Implementation

[0036] 1. First Implementation Method

[0037] 1-1. Structure of resin tube 1 with connector

[0038] Reference Figure 1 The resin tube 1 with connector, which is the object of the manufacturing method of this embodiment, will be described. The resin tube 1 with connector is used, for example, in various fluid flow paths in motor vehicles, such as fuel supply paths, cooling water flow paths, and lubricating oil flow paths. The resin tube 1 with connector is integrally formed into a long cylindrical shape, with both ends connected to other piping, pipes, or other components. That is, the resin tube 1 with connector allows fluid to flow between a component (not shown) connected to one end and another component (not shown) connected to the other end.

[0039] For example, in the case of a resin tube 1 with a connector being used in a fuel supply circuit, one end of the resin tube 1 with a connector is connected to a fuel delivery pipe connected to an injector of the engine, and the other end is connected to a piping component on the fuel tank side.

[0040] like Figure 1 As shown, the resin tube 1 with connectors includes a resin tube 2, a first connector 3, and a second connector 4. The resin tube 1 with connectors is formed into a single unit by joining the first connector 3 and the second connector 4 to the resin tube 2. It should be noted that in this embodiment, an example is shown where the resin tube 1 with connectors includes both the first connector 3 and the second connector 4, but it may also have only one of the connectors, such as only the first connector 3.

[0041] The resin tube 2 is formed into a long cylindrical shape and has at least one curved section. The number, angle, and distance between adjacent curved sections are appropriately varied depending on the environment in which the resin tube 2 is arranged. Figure 1 The image shows an example where the resin tube 2 is S-shaped, that is, has two U-shaped bends.

[0042] For example, when gasoline is being supplied, the resin tube 2 has a multi-layered structure considering gasoline resistance, fuel permeability resistance, and weather resistance. That is, the resin tube 2 is made of a resin material corresponding to the fluid being supplied. Furthermore, in this embodiment, the resin tube 2 is joined to the first connector 3 and the second connector 4 by laser welding, and therefore is formed from a material with a higher laser absorption rate than the first connector 3 and the second connector 4.

[0043] The resin tube 2 includes a first end portion 21, a second end portion 22, and an intermediate portion 23. The first end portion 21 constitutes one end of the resin tube 2. In this embodiment, the first end portion 21 is formed as a straight tube, specifically a non-corrugated tube. However, the first end portion 21 is not limited to a straight tube shape; for example, it can be formed in any shape, such as corrugated, and is not limited to a non-corrugated tube shape; it can also be formed as a corrugated tube. The open end of the first end portion 21 (hereinafter referred to as "first end 21A") constitutes the first open end of the resin tube 2. Here, "straight tube" refers to a tube with its central axis on a straight line, and the same applies below.

[0044] The second end portion 22 constitutes the other end of the resin tube 2. In this embodiment, the second end portion 22 is formed as a straight tube, specifically a non-corrugated tube. However, the second end portion 22 is not limited to a straight tube shape; for example, it can be formed in any shape, such as a corrugated shape, and it is not limited to a non-corrugated tube shape; it can also be formed as a corrugated tube. The open end portion of the second end portion 22 (hereinafter referred to as "second end portion 22A") constitutes the second open end portion of the resin tube 2.

[0045] The intermediate tube portion 23 constitutes the middle part of the resin tube 2. That is, the intermediate tube portion 23 is the part that connects the first end tube portion 21 and the second end tube portion 22. The intermediate tube portion 23 has a bend. In this embodiment, the intermediate tube portion 23 has two U-shaped bends, forming an S-shape. However, the intermediate tube portion 23 can have any bend. In addition, the intermediate tube portion 23 is formed as a corrugated tube. However, the intermediate tube portion 23 is not limited to a corrugated tube shape and can also be formed as a non-corrugated tube shape.

[0046] The first connector 3 is formed into a cylindrical shape from resin. The first connector 3 is joined to one end side of the resin tube 2, namely the first end portion 21A, by laser welding. The first connector 3 has at least a cylindrical end 31. The first end portion 21A of the first end portion 21 of the resin tube 2 is fitted into the end 31 of the first connector 3, and the end 31 of the first connector 3 is joined to the first end portion 21A of the first end portion 21.

[0047] In this configuration, the first end portion 21A of the first end tube 21 of the resin tube 2 is inserted radially inward to the end portion 31 of the first connector 3. Furthermore, the inner circumferential surface of the end portion 31 of the first connector 3 and the outer circumferential surface of the first end portion 21A of the first end tube 21 are joined by laser welding. However, the first end portion 21A of the first end tube 21 of the resin tube 2 can also be fitted radially outward to the end portion 31 of the first connector 3. In this case, the outer circumferential surface of the end portion 31 of the first connector 3 and the inner circumferential surface of the first end portion 21A of the first end tube 21 are joined by laser welding.

[0048] At least one end 31 of the first connector 3 is formed of a resin material whose laser absorption rate is lower than that of the resin tube 2. Alternatively, the entire first connector 3 may be formed of a resin material whose laser absorption rate is lower than that of the resin tube 2.

[0049] The base resin of the first connector 3 may be, for example, polypropylene, polyamide, polyphenylene sulfide, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polymethylpentene, polyethylene, polyacetal, fluoropolymer, etc. For example, polypropylene with a refractive index of 1.47 to 1.51 is used as the polypropylene. Similarly, for example, polyamide with a refractive index of 1.51 to 1.55 is used as the polyamide.

[0050] The first connector 3 may also contain reinforcing fillers if strength is required. Reinforcing fillers may include, for example, glass fiber, carbon fiber, potassium titanate, glass beads, ground fibers, and talc.

[0051] The first connector 3 can be composed of a single component element or multiple component elements connected to each other. For example, in the case where the first connector 3 is a known quick connector, it is composed of multiple component elements.

[0052] The second connector 4 is formed into a cylindrical shape from resin. The second connector 4 is joined to the other end side of the resin tube 2, namely the second end cylindrical portion 22, by laser welding. The second connector 4 has at least a cylindrical end 41. The second end 22A of the second end cylindrical portion 22 of the resin tube 2 is fitted into the end 41 of the second connector 4, and the end 41 of the second connector 4 is joined to the second end 22A of the second end cylindrical portion 22.

[0053] In this configuration, the second end portion 22A of the second end tube 22 of the resin tube 2 is inserted radially inward to the end portion 41 of the second connector 4. Furthermore, the inner circumferential surface of the end portion 41 of the second connector 4 and the outer circumferential surface of the second end portion 22A of the second end tube 22 are joined by laser welding. However, the second end portion 22A of the second end tube 22 of the resin tube 2 can also be fitted radially outward to the end portion 41 of the second connector 4. In this case, the outer circumferential surface of the end portion 41 of the second connector 4 and the inner circumferential surface of the second end portion 22A of the second end tube 22 are joined by laser welding.

[0054] At least one end 41 of the second connector 4 is formed of a resin material with a lower laser absorption rate than that of the resin tube 2. Alternatively, the entire second connector 4 may be formed of a resin material with a lower laser absorption rate than that of the resin tube 2. The second connector 4 may also be formed of the same resin material as the first connector 3. The second connector 4 may also be formed of a different resin material than the first connector 3. Furthermore, like the first connector 3, the second connector 4 may be composed of a single component element or multiple component elements interconnected.

[0055] 1-2. Manufacturing method of resin tube 1 with connector

[0056] Reference Figures 2-7 The manufacturing method of the resin tube 1 with connector is described. For example... Figure 2 as well as Figure 3 As shown in (A), a resin tube blank 5 is formed (S1: resin tube blank forming process). The resin tube blank 5 is formed, for example, by extrusion molding. It should be noted that the resin tube blank 5 in this embodiment has a corrugated section as described later, and is therefore formed by extrusion molding and corrugation molding. For example, extrusion suction molding, extrusion blow molding, etc. can be applied. It should be noted that the resin tube blank 5 can also be a cylindrical shape without a corrugated section, that is, it is composed of a non-corrugated section throughout its entire length.

[0057] Resin tube blank 5 and Figure 1 The resin tube 2 shown is different; it is a shape in which the intermediate cylindrical portion 24 has not undergone bending processing. For example, as... Figure 3 As shown in (A), the resin tube blank 5 is composed of straight tube sections (straight tubular sections) throughout its entire length. In this case, the first end tubular section 21, the second end tubular section 22, and the intermediate tubular section 24 constituting the resin tube blank 5 are all formed as coaxial straight tubes. Here, for convenience, the straight tubular portions of the resin tube blank 5, namely the first end tubular section 21, the second end tubular section 22, and the intermediate tubular section 24, are referred to as straight tube sections. It should be noted that the resin tube blank 5 is preferably composed of straight tube sections throughout its entire length, but it may also have slightly curved sections.

[0058] The first end cylindrical portion 21 and the second end cylindrical portion 22 are composed of Figure 1 The first end portion 21 and the second end portion 22 of the resin tube 1 with connector shown in the final form are identical. The intermediate portion 24 is the same as that which will constitute... Figure 1 The final form of the resin tube 1 with connector shown corresponds to the middle tube portion 23 being formed as a straight tube. That is, the middle tube portion 24 is a straight tube-shaped corrugated tube portion. Moreover, the middle tube portion 24 is located coaxially with the first end tube portion 21 and the second end tube portion 22.

[0059] Therefore, the resin tube blank 5 has a first end tube portion 21 as a non-corrugated tube portion, a second end tube portion 22 as a non-corrugated tube portion, and an intermediate tube portion 24 as a corrugated tube portion, all of which are located coaxially.

[0060] In the manufacturing method of the resin tube 1 with connector, such as Figure 2 As shown, the first connector 3 and the second connector 4 are formed (S2: connector forming process). The first connector 3 and the second connector 4 are formed, for example, by injection molding. Of course, the first connector 3 and the second connector 4 are not limited to injection molding and can be formed by any method.

[0061] Next, as Figure 2 as well as Figure 3 As shown in (A) and (B), the first end 21A of the resin tube blank 5, which is composed of a straight tube portion throughout its entire length, is fitted into the end 31 of the cylindrical first connector 3 (S3: fitting process). In the fitting process S3 of this embodiment, the first end 21A of the resin tube blank 5 is inserted into the radially inner side of the end 31 of the first connector 3. At this time, the first end 21A of the resin tube blank 5 can be compressed while being pressed into the end 31 of the first connector 3. As a result, the outer peripheral surface of the first end 21A of the resin tube blank 5 is formed to be in close contact with the inner peripheral surface of the end 31 of the first connector 3.

[0062] Reference Figure 4 The mating portion between the first end 21A of the resin tube blank 5 and the end 31 of the first connector 3 will be described in detail. For example... Figure 4 As shown, the end 31 of the first connector 3 is at the open end of the end 31 of the first connector 3 ( Figure 4 The inner circumferential surface of the right end has a guide portion 31A formed in a cone shape.

[0063] The maximum inner diameter of the tapered guide portion 31A is the same as, or slightly larger than, the outer diameter of the first end 21A of the resin tube blank 5 before shrinkage deformation. Conversely, the minimum inner diameter of the tapered guide portion 31A is smaller than the outer diameter of the first end 21A of the resin tube blank 5 before shrinkage deformation. Therefore, when the resin tube blank 5 is inserted into the inner side of the end 31 of the first connector 3, the guide portion 31A abuts against the outer peripheral surface of the resin tube blank 5. Then, the guide portion 31A guides the shrinkage of the resin tube blank 5.

[0064] Furthermore, the end 31 of the first connector 3 has a cylindrical inner circumferential surface 31B formed adjacent to the guide portion 31A on its inner circumferential surface and is formed in the shape of a cylindrical inner circumferential surface. The inner diameter of the cylindrical inner circumferential surface 31B of the end 31 of the first connector 3 is the same as the minimum inner diameter of the guide portion 31A. That is, the inner diameter of the cylindrical inner circumferential surface 31B is smaller than the outer diameter of the first end 21A of the resin tube blank 5 before shrinkage deformation. Therefore, the first end 21A of the resin tube blank 5 is inserted into the radially inner side of the cylindrical inner circumferential surface 31B in a shrinkage state. That is, the cylindrical inner circumferential surface 31B and the outer circumferential surface of the first end 21A of the resin tube blank 5 after shrinkage are formed in a tight fit.

[0065] Furthermore, the end 31 of the first connector 3 has an opening side ( Figure 4 The right side of the resin tube blank 5 is the positioning end face 31C for the normal. The positioning end face 31C positions the resin tube blank 5 by abutting against the front end face of the first end 21A of the resin tube blank 5. In this way, the first end 21A of the resin tube blank 5 is fitted into the end 31 of the first connector 3.

[0066] It should be noted that the first end 21A of the resin tube blank 5 can also be embedded radially outward of the end 31 of the first connector 3. In this case, the first end 21A of the resin tube blank 5 can be expanded while being pressed into the end 31 of the first connector 3. As a result, the inner circumferential surface of the first end 21A of the resin tube blank 5 and the outer circumferential surface of the end 31 of the first connector 3 are in close contact.

[0067] Similarly, the second end 22A of the resin tube blank 5, i.e., the second end portion 22, is fitted into the end 41 of the cylindrical second connector 4 (S3: fitting process). In the fitting process S3 of this method, the second end 22A of the resin tube blank 5 is inserted into the radially inner side of the end 41 of the second connector 4. At this time, the second end 22A of the resin tube blank 5 can be compressed while being pressed into the end 41 of the second connector 4. As a result, the outer peripheral surface of the second end 22A of the resin tube blank 5 is formed to be in close contact with the inner peripheral surface of the end 41 of the second connector 4. Here, the end 41 of the second connector 4 can be formed in the same way as the end 31 of the first connector 3.

[0068] It should be noted that the second end 22A of the resin tube blank 5 can also be embedded radially outward of the end 41 of the second connector 4. In this case, the second end 22A of the resin tube blank 5 can be expanded while being pressed into the end 41 of the second connector 4. As a result, the inner circumferential surface of the second end 22A of the resin tube blank 5 and the outer circumferential surface of the end 41 of the second connector 4 are in close contact.

[0069] like Figure 3 As shown in (B), a one-piece molded body 101 with connectors, in which the first connector 3 and the second connector 4 are embedded in the resin tube blank 5, is formed by the insertion process S3. In the one-piece molded body 101, the resin tube blank 5 and the first connector 3, and the resin tube blank 5 and the second connector 4 are respectively formed into one piece by fitting.

[0070] Next, as Figure 2 As shown, the embedded resin tube blank 5 is joined to the first connector 3 and the second connector 4 by laser welding to form a secondary molded body 201 of the resin tube with connectors (S4: joining process).

[0071] Here, refer to Figure 5 An example of a laser welding device 6 will be described. Device 6 includes, for example, a base 61, multiple support clamps 62 and 63, a guide rail 64, a laser irradiation device 65, and a rotation drive device (not shown). The multiple support clamps 62 and 63 are mounted on the base 61 and their positions can be changed. For example, the multiple support clamps 62 and 63 are mounted on the base 61 in a manner that allows for changing their relative distance.

[0072] Multiple support clamps 62 and 63 support the primary molded body 101 after it has been assembled in the insertion process S3. For example, the multiple support clamps 62 and 63 support a portion of the resin tube blank 5 constituting the primary molded body 101. However, the multiple support clamps 62 and 63 can also support portions of the first connector 3 and the second connector 4 constituting the primary molded body 101. Furthermore, the multiple support clamps 62 and 63 support the primary molded body 101 so that it can rotate.

[0073] A rotary drive device (not shown) rotates the primary molded body 101, which is supported by multiple support jigs 62 and 63. The rotary drive device can be integrated into the support jigs 62 and 63, or it can be a separate component from them. Here, the rotary drive device rotates the primary molded body 101 about its central axis. That is, the radius of rotation of the primary molded body 101 is equal to the radius of the largest outer diameter portion of the resin tube blank 5, the first connector 3, and the second connector 4 constituting the primary molded body 101.

[0074] The guide rail 64 is in the direction of the multiple support clamps 62 and 63 arranged thereon. Figure 5 The position of separation in the direction orthogonal to the left and right directions is set in the direction where multiple support clamps 62 and support clamps 63 are arranged ( Figure 5 It extends in a direction parallel to the left and right sides.

[0075] The laser irradiation device 65 is configured to move along the guide rail 64 and is a device for irradiating the laser RB used for laser welding. It should be noted that the device 6 only needs to be able to move relative to the primary molded body 101 and the laser irradiation device 65 in the direction of the central axis of the primary molded body 101. For example, the device 6 may also be configured to allow the support clamps 62 and 63 supporting the primary molded body 101 to move along the guide rail. In this case, the primary molded body 101 moves relative to the base 61.

[0076] In this method, the joining process S4 includes a first joining process S4A that joins the first end 21A of the resin tube blank 5 with the end 31 of the first connector 3, and a second joining process S4B that joins the second end 22A of the resin tube blank 5 with the end 41 of the second connector 4 after the first joining process S4A.

[0077] Reference Figure 4 as well as Figure 5The first joining process S4A will be described. First, the primary molded body 101 is formed to be supported by a plurality of support jigs 62 and 63. In particular, the plurality of support jigs 62 and 63 support the straight tube portion of the resin tube blank 5 of the primary molded body 101. Then, the laser irradiation device 65 is positioned opposite the mating portion of the first end 21A of the resin tube blank 5 and the end 31 of the first connector 3 in the primary molded body 101. Next, while the primary molded body 101 is rotated about its central axis by a rotation drive device, the laser irradiation device 65 irradiates the primary molded body 101 with laser RB.

[0078] Therefore, the laser irradiation device 65 irradiates the outer peripheral surface of the end 31 of the first connector 3 with laser RB. The irradiated end 31 of the first connector 3 is formed of a resin material with high laser transmittance of laser RB. Thus, laser RB passes through the end 31 of the first connector 3 and reaches the contact surface between the end 31 of the first connector 3 and the first end 21A of the resin tube blank 5. Figure 4 In the process, the laser RB reaches the inner circumferential surface 31B of the cylinder at the end 31 of the first connector 3. At the first end 21A of the resin tube blank 5, the laser RB is absorbed and generates heat.

[0079] Then, the end 31 of the first connector 3 is joined to the first end 21A of the resin tube blank 5 by laser welding. The laser RB irradiates the entire circumference of the outer peripheral surface of the end 31 of the first connector 3. Thus, the end 31 of the first connector 3 is joined to the first end 21A of the resin tube blank 5 by laser welding throughout the entire circumference.

[0080] Next, refer to Figure 6 The second joining process S4B will be described. For the one-piece molded body 101, after joining the end 31 of the first connector 3 to the first end 21A of the resin tube blank 5, the end 41 of the second connector 4 is then joined to the second end 22A of the resin tube blank 5.

[0081] First, the primary molded body 101 is maintained in a state supported by multiple support jigs 62 and 63. Then, the laser irradiation device 65 is positioned opposite the mating portion of the second end 22A of the resin tube blank 5 and the end 41 of the second connector 4 in the primary molded body 101. Next, while rotating the primary molded body 101 about its central axis using a rotation drive device, laser RB is irradiated by the laser irradiation device 65.

[0082] Therefore, the laser irradiation device 65 irradiates the outer peripheral surface of the end 41 of the second connector 4 with laser RB. The irradiated end 41 of the second connector 4 is formed of a resin material with high laser transmittance of laser RB. Thus, laser RB passes through the end 41 of the second connector 4 and reaches the contact surface between the end 41 of the second connector 4 and the second end 22A of the resin tube blank 5. At the second end 22A of the resin tube blank 5, laser RB is absorbed and heat is generated.

[0083] Then, the end 41 of the second connector 4 is joined to the second end 22A of the resin tube blank 5 by laser welding. Laser RB irradiates the entire circumference of the outer peripheral surface of the end 41 of the second connector 4. Therefore, the end 41 of the second connector 4 and the second end 22A of the resin tube blank 5 are joined by laser welding throughout the entire circumference. Thus, a secondary molded body 201 is formed on the resin tube blank 5, with the first connector 3 and the second connector 4 joined thereon. The secondary molded body 201 is a straight tube.

[0084] Next, as Figure 2 As shown, using a posture holding mold 7 for bending a portion of the straight tube portion of the resin tube blank 5, at least a portion of the straight tube portion of the resin tube blank 5 constituting the secondary forming body 201 is held in a heated and bent state (S5: heating and holding process).

[0085] Reference Figure 7 The posture-holding mold 7 will be described. The posture-holding mold 7 includes a bending section 71 for bending a portion of the straight tube portion of the resin tube blank 5 of the secondary molded body 201. In this embodiment, the bending section 71 is a groove into which the secondary molded body 201 can be inserted to maintain its shape. The groove of the bending section 71 is formed to allow the secondary molded body 201 to be inserted along its entire length. However, the groove of the bending section 71 may also be formed only in a portion of the secondary molded body 201, particularly in the area where the bending process is performed. It should be noted that the posture-holding mold 7 only needs to be able to maintain the posture of the secondary molded body 201 in a bent state; the bending section 71 can be formed in any shape other than the groove. Regarding the type of posture-holding mold 7 (bending mold), it is not limited to this embodiment; posture-holding molds of any shape and material can be used.

[0086] Furthermore, in this method, the intermediate cylindrical portion 24 of the straight section of the resin tube blank 5 is bent. That is, the intermediate cylindrical portion 24, which is a corrugated portion, is the part to be bent. Therefore, the bending processing section 71 of the posture holding mold 7 only needs to be able to keep the intermediate cylindrical portion 24, which is a corrugated portion, of the resin tube blank 5 in a bent state.

[0087] Furthermore, the first end section 21 and the second end section 22 of the straight tube portion of the resin tube blank 5 remain in a straight tube state. Therefore, the bending processing section 71 of the posture holding mold 7 holds the entire length of the secondary forming body 201, and a portion of the bending processing section 71, which serves as the first end section 21 and the second end section 22 of the non-corrugated tube portion, remains in a straight tube state.

[0088] In this embodiment, the heating and holding process S5 includes a preheating process S5A and a bending and holding process S5B. The preheating process S5A heats at least the intermediate cylinder portion 24 of the straight tube portion of the resin tube blank 5 that undergoes bending. However, in this embodiment, the preheating process S5A heats the entire length of the resin tube blank 5, i.e., the entire length of the straight tube portion.

[0089] In the bending and holding process S5B, at least the intermediate cylinder portion 24 of the straight tube portion of the heated resin tube blank 5 is placed in the bending processing section 71 of the posture holding mold 7, and the intermediate cylinder portion 24 of the straight tube portion of the resin tube blank 5 is held in a bent state by the bending processing section 71 of the posture holding mold 7.

[0090] The resin tube blank 5 is heated, and the intermediate cylindrical portion 24 of the resin tube blank 5 is held in a bent state for a certain period of time. This bending process is performed on the intermediate cylindrical portion 24 of the resin tube blank 5, and the stress in the bent portion is relieved by heating, thus stabilizing the bent portion. In addition, by heating the entire resin tube blank 5, the stress is relieved even outside the bent portion, and the shape is stabilized.

[0091] Next, as Figure 2 As shown, the secondary formed body 201, which has been heated and bent in the heat holding process S5, is cooled (S6: cooling process). Thus, a... Figure 1 The resin tube 1 with connector shown. Here, cooling can be performed while the secondary molded body 201 is held in the posture holding mold 7, or it can be removed from the posture holding mold 7 for cooling.

[0092] 1-3. Effects

[0093] In the fitting process S3, where the first end 21A and the second end 22A of the resin tube blank 5 are fitted with the ends 31 of the cylindrical first connector 3 and the second connector 4, the resin tube blank 5 is in a state with a straight tube portion. Furthermore, in the state where the resin tube blank 5 has a straight tube portion, the first end 21A and the second end 22A of the resin tube blank 5 are joined with the ends 31 of the first connector 3 and the second connector 4 by laser welding. Afterwards, in the heat holding process S5, the intermediate cylindrical portion 24 in the straight tube portion of the resin tube blank 5 is bent using a posture holding mold 7.

[0094] That is, with the resin tube blank 5 having a straight section, the resin tube blank 5 is joined to the first connector 3 and the second connector 4 by laser welding. Then, the resin tube blank 5 is bent in the heat holding process S5. Therefore, during laser welding, the resin tube blank 5 in its state before bending is supported. That is, when laser welding is performed while rotating the primary forming body 101 to be welded, if the resin tube blank 5 before bending is compared with the resin tube 1 with connectors as the final forming part after bending, the former has a very small radius of rotation. Therefore, by performing laser welding on the resin tube blank 5 before bending and the first connector 3 and the second connector 4, miniaturization of the laser welding equipment 6 can be achieved.

[0095] Furthermore, during laser welding, the resin tube blank 5, before bending, is supported by the support fixtures 62 and 63 in the laser welding equipment 6. The straight sections of the resin tube blank 5 can be supported by the support fixtures 62 and 63. Even for resin tube blanks of different shapes that constitute the resin tube 2 of the connector-equipped resin tube 1 as the final formed part, the straight sections of each resin tube blank 5 before bending can be supported during laser welding. Therefore, sometimes it is not necessary to changeover adjustments to the support fixtures 62 and 63 in the laser welding equipment 6. Even if changeover adjustments to the support fixtures 62 and 63 are required, they can be completed with less time. Therefore, the time required for changeover adjustments to the support fixtures 62 and 63 can be reduced.

[0096] As described above, support fixtures 62 and 63 support the resin tube blank 5 in its state before bending. By configuring it in this way, compared to the case where support fixtures 62 and 63 support a portion of the resin tube 2 after bending, the space required to secure the positions of support fixtures 62 and 63 in the laser welding equipment 6 can be reduced. Therefore, miniaturization of the laser welding equipment 6 is possible.

[0097] In the joining process S4, the first end 21A of the resin tube blank 5 is joined to the end 31 of the first connector 3 by laser welding. Then, the second end 22A of the resin tube blank 5 is joined to the end 41 of the second connector 4 by laser welding. Next, the intermediate cylindrical portion 24 of the resin tube blank 5 is bent in a subsequent process. Therefore, when performing laser welding on two consecutive locations, the laser irradiation device 65 and the resin tube blank 5 can be moved relative to each other along the central axis of the resin tube blank 5. In this way, even using only one laser irradiation device 65, it is easy to perform laser welding on two consecutive locations.

[0098] In particular, in the insertion process S3, the first end 21A and the second end 22A of the resin tube blank 5, which is composed of a straight tube section throughout its entire length, are inserted into the end 31 of the first connector 3 and the end 41 of the second connector 4. That is, in the joining process S4, the resin tube blank 5, which is in a straight tube shape throughout its entire length, and the first connector 3 and the second connector 4 are laser welded. Therefore, when laser welding is performed while rotating the one-piece molded body 101, which is to be welded, the rotation radius is minimized. Therefore, the laser welding equipment 6 can be miniaturized.

[0099] Furthermore, the resin tube blank 5 has an intermediate cylindrical portion 24 that serves as a corrugated section. Moreover, in the heat-holding process S5, the intermediate cylindrical portion 24, which serves as a corrugated section in the straight tube, is held in a heated and bent state by the bending processing section 71 of the posture-holding mold 7. Therefore, the resin tube blank 5 can be easily positioned in the posture-holding mold 7.

[0100] Furthermore, the straight tube portion of the resin tube blank 5 includes a first end tube portion 21 and a second end tube portion 22, which are non-corrugated sections, and an intermediate tube portion 24, which is also a non-corrugated section. Moreover, in the heat-holding process S5, the intermediate tube portion 24, which is a corrugated section, is held in a heated and bent state by the bending processing section 71 of the posture-holding mold 7. On the other hand, the first end tube portion 21 and the second end tube portion 22, which are non-corrugated sections, are held in a straight tube state. Therefore, not only the intermediate tube portion 24, which undergoes bending processing, but also the first end tube portion 21 and the second end tube portion 22, which maintain a straight tube state, are formed into a shape that is stress-relieving and stable.

[0101] Furthermore, the heating and holding process S5 is performed after the preceding heating process S5A, followed by the bending and holding process S5B. After heating the secondary molded body 201, the secondary molded body 201 is held in a bent state in the posture holding mold 7. Since the secondary molded body 201 is heated, it can be easily positioned in the posture holding mold 7.

[0102] Furthermore, in the insertion process S3, the first end 21A and the second end 22A of the resin tube blank 5 are inserted radially inside the end 31 of the first connector 3 and the end 41 of the second connector 4. Then, in the joining process S4, laser RB is irradiated from the radially outer side of the end 31 of the first connector 3 and the end 41 of the second connector 4 towards their outer peripheral surfaces. Using the laser RB that passes through the end 31 of the first connector 3 and the end 41 of the second connector 4, the first end 21A and the second end 22A of the resin tube blank 5 are joined to the end 31 of the first connector 3 and the end 41 of the second connector 4 by laser welding. Since laser RB can be irradiated from the radially outer side, the laser welding device 6 has a simple structure. Moreover, even using a single laser irradiation device 65, laser welding can be easily performed continuously at two locations.

[0103] Furthermore, in the joining process S4, multiple portions of the resin tube blank 5 are supported by multiple support clamps 62 and 63. In particular, multiple portions of the straight tube section of the resin tube blank 5 are supported by multiple support clamps 62 and 63. In this state, the first end 21A and the second end 22A of the embedded resin tube blank 5 are joined to the end 31 of the first connector 3 and the end 41 of the second connector 4 by laser welding. In this way, multiple portions of the straight tube section of the resin tube blank 5 are supported by support clamps 62 and 63. Even if the length of the resin tube blank 5 to be welded changes, the positions of the multiple support clamps 62 and 63 do not need to be changed at all, or if changes are necessary, they only need to be slightly changed.

[0104] In particular, in the joining process S4, the first end 21A and the second end 22A of the resin tube blank 5 are joined to the end 31 of the first connector 3 and the end 41 of the second connector 4 by laser welding while rotating the resin tube blank 5, the first connector 3, and the second connector 4. This allows for easy laser welding throughout the entire circumference of the first connector 3 and the second connector 4. Furthermore, even with this method, the laser welding equipment 6 can be miniaturized.

[0105] In this embodiment, during the joining process S4, the resin tube blank 5, the first connector 3, and the second connector 4 are rotated while being irradiated with laser RB, thereby joining the first end 21A and the second end 22A of the resin tube blank 5 with the end 31 of the first connector 3 and the end 41 of the second connector 4 by laser welding. Alternatively, during the joining process S4, the laser irradiation device 65 may be rotated while being irradiated with laser RB, thereby joining the first end 21A and the second end 22A of the resin tube blank 5 with the end 31 of the first connector 3 and the end 41 of the second connector 4 by laser welding.

[0106] 2. Second Implementation Method

[0107] Reference Figure 8 as well as Figure 9 The manufacturing method of the resin tube 1 with connector according to the second embodiment will be described. For example... Figure 8 As shown, the resin tube blank 5 is formed in step S11, the first connector 3 and the second connector 4 are formed in step S12, and the insertion step S13 is performed. S11, S12 and S13 are the same as S1, S2 and S3 in the first embodiment.

[0108] Next, in the joining process S14, the first joining and the second joining are performed simultaneously. That is, in the joining process S14, while the first end 21A of the resin tube blank 5 is joined to the end 31 of the first connector 3 by laser welding, the second end 22A of the resin tube blank 5 is joined to the end 41 of the second connector 4 by laser welding.

[0109] Here, refer to Figure 9 The equipment 8 used for laser welding in the joining process S14 will be described. The equipment 8 includes two laser irradiation devices 65A and 65B. One laser irradiation device 65A performs laser welding of the first end 21A of the resin tube blank 5 to the end 31 of the first connector 3. The other laser irradiation device 65B performs laser welding of the second end 22A of the resin tube blank 5 to the end 41 of the second connector 4. That is, while rotating the primary molded body 101, laser RB is irradiated at two locations, thereby forming the secondary molded body 201.

[0110] Next, a heating and holding process S15 is performed, followed by a cooling process S16. The heating and holding process S15 follows the preceding heating process S15A, and a bending and holding process S15B is performed afterward. S15, S15A, S15B, and S16 are the same as S5, S5A, S5B, and S6 in the first embodiment. In this way, a resin tube 1 with a connector is manufactured.

[0111] In this method, two laser irradiation devices 65A and 65B are used to perform laser welding at two locations simultaneously. This is achieved because the resin tube blank 5 is laser welded before bending. In particular, this is made easier by making the resin tube blank 5 a straight tube along its entire length. As a result, the time required for laser welding can be shortened.

[0112] 3. Third Implementation Method

[0113] Reference Figure 10 The manufacturing method of the resin tube 1 with connector according to the third embodiment will be described. For example... Figure 10 As shown, the following steps are performed: forming resin tube blank 5 (S21), forming first connector 3 and second connector 4 (S22), inserting (S23), and joining (S24). In joining step S24, a second joining step S24B is performed after the first joining step S24A. Here, S21, S22, S23, S24, S24A, and S24B are the same as S1, S2, S3, S4, S4A, and S4B in the first embodiment.

[0114] Next, a heating and holding process S25 is performed. The heating and holding process S25 is a post-heating process S25B performed after the bending and holding process S25A. In the bending and holding process S25A, at least the intermediate cylindrical portion 24 of the straight tube portion of the resin tube blank 5 is placed in the bending processing section 71 of the posture holding mold 7, and the intermediate cylindrical portion 24 of the straight tube portion of the resin tube blank 5 is held in a bent state by the bending processing section 71 of the posture holding mold 7.

[0115] Then, in the post-heating process S25B, the resin tube blank 5 held in the posture holding mold 7 is heated. That is, the intermediate tube portion 24 in the straight tube section is heated in a bent state. At this time, the parts other than the intermediate tube portion 24, namely the first end tube portion 21 and the second end tube portion 22, are also heated.

[0116] Next, a cooling process S26 is performed. S26 is the same as S6 in the first embodiment. This manufactures the resin tube 1 with the connector. In this embodiment, the same effect as in the first embodiment is achieved. It should be noted that the joining process S24 in this embodiment can also be replaced by the joining process S14 of the second embodiment. That is, the first joining and the second joining are performed simultaneously in the joining process S24.

[0117] 4. Fourth Implementation Method

[0118] Reference Figure 11 The manufacturing method of the resin tube 301 with connector according to the fourth embodiment will be described. Figure 11The image shows a resin tube 301 with a connector, which is the object of the manufacturing method of this embodiment. The resin tube 301 with connector is composed of a non-corrugated cylindrical portion throughout its entire length. That is, the resin tube 9 constituting the resin tube 301 with connector has a first end cylindrical portion 21, a second end cylindrical portion 22, and an intermediate cylindrical portion 25. The first end cylindrical portion 21 and the second end cylindrical portion 22 are the same as in the first embodiment.

[0119] The intermediate cylindrical section 25 is composed of a non-corrugated cylindrical section. This differs from the first embodiment where the intermediate cylindrical section 23 is corrugated; the intermediate cylindrical section 25 in this embodiment is non-corrugated. Even though the intermediate cylindrical section 25 is non-corrugated, it essentially achieves the same effect as the first embodiment.

Claims

1. A method for manufacturing a resin tube (1, 301) with a connector, wherein the resin tube (1, 301) with a connector has a bent portion, wherein, The method for manufacturing the resin tube (1, 301) with connector includes: In the insertion process (S3, S13, S23), the ends (21A, 21B) of the resin tube blank (5) having a straight tube section are inserted into the ends (31, 41) of the cylindrical connector (3, 4). In the joining process (S4, S14, S24), the end of the embedded resin tube blank is joined to the end of the connector by laser welding. In the heating and holding process (S5, S15, S25), a posture holding mold (7) having a bending processing section (71) for bending the straight tube section is used. The bending processing section of the posture holding mold holds the straight tube section in a heated and bent state. Cooling process (S6, S16, S26): In the cooling process (S6, S16, S26), the straight pipe section is cooled.

2. The method for manufacturing the resin tube (1, 301) with connector according to claim 1, wherein, In the mounting process (S3, S23), the first end of the resin tube blank is mounted to the end (31) of the first connector (3) which serves as the connector, and the second end of the resin tube blank is mounted to the end (41) of the second connector (4) which serves as the connector. In the joining process (S4, S24), the first end of the resin tube blank is joined to the end of the first connector by laser welding, and then the second end of the resin tube blank is joined to the end of the second connector by laser welding.

3. The method for manufacturing the resin tube (1, 301) with connector according to claim 1, wherein, In the mounting process (S13), the first end (21A) of the resin tube blank is mounted to the end (31) of the first connector (3) which serves as the connector, and the second end (22A) of the resin tube blank is mounted to the end (41) of the second connector (4) which serves as the connector. In the joining process (S14), while joining the first end of the resin tube blank to the end of the first connector by laser welding, the second end of the resin tube blank to the end of the second connector is joined by laser welding.

4. The method for manufacturing the resin tube (1, 301) with connector according to any one of claims 1 to 3, wherein, In the mounting process (S3, S13, S23), the end of the resin tube blank, which is composed of the straight tube section throughout its entire length, is mounted to the end of the connector.

5. The method for manufacturing the resin tube (1) with connector according to any one of claims 1 to 3, wherein, The straight pipe section has a corrugated section (24) in at least a portion. In the heating and holding process (S5, S15, S15), the bending processing part of the straight tube section (24) is held in a heated and bent state by the bending processing part of the posture holding mold.

6. The method for manufacturing the resin tube (1) with connector according to claim 5, wherein, The straight pipe section has the corrugated section (24) and the non-corrugated section (21, 22). In the heating and holding process (S5, S15, S25), The bending processing section of the mold, using the aforementioned posture, keeps the corrugated section of the straight tube in a heated and bent state. The non-corrugated section is kept in a straight tube state.

7. The method for manufacturing the resin tube (301) with connector according to any one of claims 1 to 3, wherein, The straight pipe section has a non-corrugated section in at least a portion. In the heating and holding process (S5, S15, S25), the bending processing part of the posture holding mold is used to hold the non-corrugated part of the straight tube in a heated and bent state.

8. The method for manufacturing the resin tube (1, 301) with connector according to any one of claims 1 to 3, wherein, The heating and holding process (S5, S15) includes: The preheating process (S5A, S15A) involves heating the straight section of the resin tube blank; and In the bending and holding process (S5B, S15B), the straight tube portion of the heated resin tube blank is placed in the bending processing section of the posture holding mold, and the straight tube portion of the resin tube blank is held in a bent state by the bending processing section of the posture holding mold.

9. A method for manufacturing a resin tube (1, 301) with a connector according to any one of claims 1 to 3, wherein, The heating and holding process (S25) includes: In the bending and holding process (S25A), the straight section of the resin tube blank is positioned in the bending processing section of the posture holding mold, and the bending processing section of the posture holding mold holds the straight section of the resin tube blank in a bent state; and In the post-heating process (S25B), the straight tube section, which is held in the bent state of the mold in the posture, is heated.

10. A method for manufacturing a resin tube (1, 301) with a connector according to any one of claims 1 to 3, wherein, In the insertion process (S3, S13, S23), the end of the resin tube blank is inserted into the radially inner side of the end of the connector.

11. The method for manufacturing the resin tube (1, 301) with connector according to claim 10, wherein, In the joining process (S4, S14, S24), a laser (RB) is irradiated from the radially outer side of the end of the connector toward the outer peripheral surface of the end of the connector, and the end of the resin tube blank is joined to the end of the connector by laser welding using the laser that has passed through the end of the connector.

12. The method for manufacturing the resin tube (1, 301) with connector according to any one of claims 1 to 3, wherein, In the joining process (S4, S14, S24), while multiple parts of the resin tube blank are supported by multiple support clamps (62, 63), the end of the embedded resin tube blank is joined to the end of the connector by laser welding.

13. The method for manufacturing the resin tube (1, 301) with connector according to claim 12, wherein, In the joining process (S4, S14, S24), multiple portions of the straight tube section of the resin tube blank are supported by multiple support clamps.

14. The method for manufacturing the resin tube (1, 301) with connector according to any one of claims 1 to 3, wherein, In the joining process (S4, S14, S24), the resin tube blank and the connector are rotated while being irradiated with a laser, thereby joining the end of the resin tube blank to the end of the connector by laser welding.

15. A method for manufacturing a resin tube (1, 301) with a connector according to any one of claims 1 to 3, wherein, In the heating and holding process (S5, S15, S25), the entire resin tube blank is heated.

Images