Method for manufacturing curved resin tubes with connectors

Abstract

To reduce length variation in curved resin tubing with resin connectors.SOLUTION: A manufacturing method for a curved resin tube with a connector comprises a bending process, a cooling process, an end cutting process, and a welding process. The bending process heats a resin tube and performs bending processing. The cooling process cools the resin tube after the bending process. The end cutting process cuts an end of the resin tube at a specified position after the cooling process. The welding process laser-welds the connector to the end of the resin tube after the end cutting process.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a bent resin tube having connectors joined to both ends. [Background technology]

[0002] In recent years, thermoplastic resins have come to be used as materials for constructing vacuum tubes, air tubes, and other components for automobiles in order to reduce the weight and cost of automobiles. Due to the increasing density of various devices in the engine compartment, these resin tubes are required to have complex three-dimensional bent shapes. Connectors are joined to both ends of these resin tubes, and the tubes are connected to mating components such as fuel pump units and fuel filters via these connectors.

[0003] For example, Patent Document 1 describes a method of joining the end of a resin tube material having a straight pipe section to the end of a cylindrical connector by laser welding, and then bending the straight pipe section of the resin tube material, in order to reduce the size of laser welding equipment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7155325 Summary of the Invention [Problem to be solved by the invention]

[0005] In general, resin tubes are bent by heating, bending, and then cooling, which causes the resin tube to expand and / or contract, potentially resulting in variations in the length of the bent resin tube.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing a curved resin tube with a connector that can reduce variations in length. [Means for solving the problem]

[0007] The manufacturing method for a bent resin tube with a connector includes a bending process, a cooling process, an end cutting process, and a welding process. The bending process involves heating and bending the resin tube. The cooling process involves cooling the resin tube after the bending process. The end cutting process involves cutting the end of the resin tube at a specified position after the cooling process. The welding process involves laser welding a connector to the end of the resin tube after the end cutting process. [Effects of the Invention]

[0008] According to the above-described method for manufacturing a curved resin tube with a connector, it is possible to reduce variations in length. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing an example of a curved resin tube 100 with a connector. [Figure 2] 3 is a flowchart showing a method for manufacturing the curved resin tube with connector 100 according to the first embodiment. [Figure 3] FIG. 10 is an explanatory view showing a state in which the resin tube 1 is fitted into a mold 101 for fixing the bend. [Figure 4] 10 is a flowchart showing a method for manufacturing the curved resin tube with connector 100 according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] [First embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (Configuration of the bent resin tube 100 with connector) The curved resin tube with connector 100 is used to circulate a fluid from a connection source to a connection destination. For example, the curved resin tube with connector 100 is used as a vacuum tube or air tube for an automobile. As shown in FIG. 1 , the curved resin tube with connector 100 of this embodiment has a resin tube 1 and connectors 2 and 3.

[0012] The resin tube 1 is formed in a tubular shape having a flow path through which a fluid passes in the longitudinal direction. The resin tube 1 is made of resin, such as polyamide. More specifically, the resin tube 1 is made of polyamide 6, polyamide 66, polyamide 612, polyamide 12, or the like. The resin tube 1 has a bent portion 1a that has been bent. There may be one bent portion 1a, or two or more bent portions 1a. The bent portion 1a may be formed by bending or curving.

[0013] The connectors 2 and 3 are used to connect the resin tube 1 to a connection source and a connection destination. The connectors 2 and 3 are provided at both ends of the resin tube 1. The connectors 2 and 3 may have the same shape. Alternatively, the connectors 2 and 3 may have different shapes depending on the connection source and the connection destination. The connectors 2 and 3 have weld portions 2a and 3a into which the resin tube 1 is fitted, as shown in FIG. 1, for example. The connectors 2 and 3 are made of resin, such as polyamide. More specifically, the resin tube 1 is made of polyamide 6, polyamide 66, polyamide 612, polyamide 12, or the like. The connectors 2 and 3 are joined to the resin tube 1 with the resin tube 1 fitted into the weld portions 2a and 3a.

[0014] The bent resin tube with connector 100 may have a plurality of resin tubes 1, and the plurality of resin tubes 1 may be connected by another connector (not shown).

[0015] (Manufacturing method of the bent resin tube with connector 100) Next, a method for manufacturing the curved resin tube with connector 100 will be described. As shown in FIG. 2, first, the resin tube 1 is molded (S10). The resin tube 1 molded in step S10 has a cylindrical shape that does not have a bent portion 1a and is straight throughout its entire length. For example, the resin tube 1 may be molded by extrusion molding or by other methods. Next, the connectors 2 and 3 are molded (S20). For example, the connectors 2 and 3 may be molded by injection molding or by other methods.

[0016] Next, a bending process is performed in which the resin tube 1 is bent (S30). For example, the bending process may include a pre-bending process (S31) and a final bending process (S32). The pre-bending process is a process in which the resin tube 1 is heated and then bent using a mechanically operated bending device (not shown). The final bending process is a process in which the resin tube 1 is heated while being fitted into a mold 101 as shown in FIG. 3. This allows the temporary bend imparted to the resin tube 1 by the bending device to become fixed. For example, in the final bending process, heating is performed within a range that does not melt the resin materials. Note that the pre-bending process may not be performed. For example, the resin tube 1 may be pre-heated, then bent manually, and fitted into the mold 101 as described above.

[0017] Next, as shown in FIG. 2, a cooling step is performed to cool the resin tube 1 (S40). The cooling step is performed after the bending step. In the cooling step, the resin tube 1 fitted into the mold 101 (see FIG. 3) is air-cooled for, for example, 20 minutes or more. Then, a resin tube removal step is performed (S45). The resin tube removal step is a step in which the resin tube 1 is removed from the mold 101.

[0018] Next, an end cutting process is performed (S50), in which the end of the resin tube 1 is cut at a specified position. The end cutting process is performed after the bending process and the cooling process. In the end cutting process, the resin tube 1 is cut in a plane perpendicular to the longitudinal direction to adjust the longitudinal length of the resin tube 1. The resin tube 1 expands and / or contracts in its longitudinal length due to heating and cooling. By performing the end cutting process, the variation in the length of the resin tube 1 between products is reduced. For example, the variation in the length from the bent portion 1a to the joint with the connector 2 (see FIG. 1) and the length from the bent portion 1a to the joint with the connector 3 (see FIG. 1) between products is reduced. Note that in the end cutting process, both ends of the resin tube 1 may be cut, or only one end may be cut.

[0019] Next, an end processing step is performed (S60). The end processing step is a step for correcting variations in the outer diameter and flattening at the end of the resin tube 1 caused by extrusion molding, the end cutting step, etc. The end processing step may be performed by cutting or by tube shrinking. This corrects the shape of the end portion of the resin tube 1 so that it can be fitted into the connectors 2 and 3. Note that the end processing step does not necessarily have to be performed.

[0020] Next, a welding process is performed (S70) in which the connectors 2 and 3 are laser-welded to the end of the resin tube 1. In the welding process, a laser beam is irradiated from the periphery by a laser beam irradiation device (not shown) onto the weld portion 2a (see FIG. 1) of the connector 2 fitted onto the end of the resin tube 1. This joins the connector 2 to the resin tube 1. The connector 3 is joined in the same manner. In this way, the connector-equipped curved resin tube 100 is manufactured.

[0021] [Second embodiment] Next, a manufacturing method of the bent resin tube with connector 100 of the second embodiment will be described with reference to the drawings. Note that a description of the configuration common to the first embodiment and the effects achieved thereby will be omitted, and the following mainly describes the differences from the first embodiment. Note that the same components as in the first embodiment are assigned the same reference numerals as in the first embodiment.

[0022] 4, first, the resin tube 1 is molded (S110) in the same manner as in the first embodiment, and then the connectors 2 and 3 are molded (S120) in the same manner as in the first embodiment.

[0023] Next, a drying step is performed to dry the resin tube 1 and / or the connectors 2 and 3 (S121). The drying step is a step of adjusting the moisture content of the resin tube 1 and / or the connectors 2 and 3 to a predetermined level or less. The drying step is preferably performed before the pre-bending welding step and / or the bending step. For example, one drying step may be performed before the pre-bending welding step and the bending step. For example, a drying step may be performed before each of the pre-bending welding step and the bending step.

[0024] Table 1 shows whether or not the resin tube 1 changed in length and whether or not peeling occurred in the welded portion relative to the moisture content of the resin tube 1 and the connectors 2 and 3. Specifically, Table 1 shows whether or not the change in length of the resin tube 1 due to heating and cooling in the bending and cooling processes was within a predetermined range. Table 1 also shows whether or not peeling occurred in the welded portion after the welding process. In Table 1, a circle indicates that the change in length of the resin tube 1 was within the predetermined range and that peeling did not occur in the welded portion. In the example of Table 1, the predetermined range for the change in length of the resin tube 1 due to heating and cooling is -3.5% to +2.5%. An × indicates that the change in length of the resin tube 1 was not within the predetermined range or that peeling occurred in the welded portion. As shown in Table 1, it is preferable to keep the moisture content of the resin tube 1 to 0.5% or less in the drying process before the welding process before the bending process. It is also preferable to keep the moisture content of the resin tube 1 to 1.0% or less in the drying process before the bending process.

[0025] [Table 1]

[0026] Next, a first terminal processing step is performed (S122). As in the first embodiment, the first terminal processing step is a step for correcting variations in outer diameter and flattening at the terminal of the resin tube 1 due to extrusion molding, the above-mentioned terminal cutting step, etc. In the first terminal processing step, only one terminal of the resin tube 1 is processed. In this embodiment, this is the terminal on the connector 2 side, but this is not limited to this. Also, the first terminal processing step does not have to be performed.

[0027] Next, a first end welding process (pre-bending welding process) is performed (S123) to laser-weld the connector 2 to one end of the resin tube 1. In the first end welding process, the connector 2 is laser-welded to one end of the resin tube 1 processed in the first end processing process.

[0028] Next, as in the first embodiment, a bending process is performed in which the resin tube 1 is bent (S130). As in the first embodiment, the bending process may include, for example, a pre-bending process (S131) ​​and a final bending process (S132). Alternatively, the resin tube 1 may be preheated and then manually bent to perform the final bending process. Although not shown, the above-described drying process may be performed again before the bending process, for example.

[0029] Next, as in the first embodiment, a cooling step is performed to cool the resin tube 1 (S140). Then, as in the first embodiment, a resin tube removal step is performed to remove the resin tube 1 from the mold 101 (S145). Then, as in the first embodiment, an end cutting step is performed to cut the end of the resin tube 1 at a specified position (S150). Note that the end cutting step in this embodiment is performed on the other end of the resin tube 1 to which the connector 2 is not welded.

[0030] Next, a second terminal processing step is performed (S160). In the second terminal processing step, the other terminal of the resin tube 1 to which the connector 2 is not welded is processed. Then, a second terminal welding step is performed on the other terminal of the resin tube 1 to which the connector 2 is not welded (S170). In the second terminal welding step, the connector 3 is laser welded to the other terminal of the resin tube 1. Although not shown, for example, the above-mentioned drying step may be performed again before the second terminal welding step. Also, the second terminal processing step may not be performed. In this manner, the curved resin tube with connector 100 is manufactured.

[0031] Although examples of the present invention have been described above, they are merely illustrative examples and do not particularly limit the present invention, and specific configurations, etc., can be appropriately modified in design. Furthermore, the actions and effects described in the embodiments of the invention are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments of the present invention.

[0032] For example, the drying process in the second embodiment (see Figure 4) may be performed before the bending process in step S30 in the first embodiment, before the terminal processing process in step S60, or before the welding process in step S70.

[0033] (Effects of the first invention) The advantages of the manufacturing method for the curved resin tube with connector 100 shown in FIG. 2 are as follows.

[0034] [Configuration 1] The manufacturing method of the bent resin tube with connector 100 includes a bending process, a cooling process, an end cutting process, and a welding process. In the bending process, the resin tube 1 is heated and bent. In the cooling process, the resin tube 1 is cooled after the bending process. In the end cutting process, the end of the resin tube is cut at a specified position after the cooling process. In the welding process, the connectors 2 and 3 are laser-welded to the end of the resin tube 1 after the end cutting process.

[0035] According to the above [Configuration 1], after the bending process, the end cutting process is performed, and then the welding process is performed. As a result, even if the length of the resin tube 1 expands or contracts due to heating or cooling in the bending process, the length can be adjusted in the end cutting process. This reduces the variation in the length of the resin tube 1 from product to product.

[0036] (Effects of the second invention) [Configuration 2] The manufacturing method of the bent resin tube with connector 100 includes a pre-bending welding step of laser-welding a connector 2 to one end of the resin tube 1 before the bending step. In the welding step, a connector 3 is laser-welded to the other end of the resin tube 1.

[0037] According to the above [Configuration 2], by first laser welding only one side of the resin tube 1, even if the shape of one side after bending is difficult to laser weld, if it is only one side, laser welding can be performed before the bending process.

[0038] (Effect of the third invention) [Configuration 3] The manufacturing method of the bent resin tube 100 with connector includes a bending process that includes a temporary bending process in which a bending device is used to give the resin tube 1 a temporary bend, and a final bending process in which the resin tube 1 is fitted into a mold 101 and the bend is fixed.

[0039] According to the above [Configuration 3], by first performing provisional bending using a bending device, manual bending is no longer necessary, and the wire can be easily fitted into the mold 101.

[0040] (Effect of the fourth invention) [Configuration 4] The manufacturing method of the bent resin tube with connector 100 includes a drying step of drying the resin tube 1 and / or the connectors 2 and 3 before the pre-bending welding step and / or the bending step.

[0041] The above [Configuration 4] can reduce expansion and contraction of the resin tube 1 caused by heating and cooling in the bending process and peeling of the welded portion in the welding process. [Explanation of symbols]

[0042] 1: Resin tube 1a: Bend section 2: Connector 2a: Welded part 3: Connector 3a: Welded part 100: Bent resin tube with connector 101: Type

Claims

1. a bending process for heating and bending the resin tube; a cooling step of cooling the resin tube after the bending step; an end cutting step of cutting an end of the resin tube at a specified position after the cooling step; a welding step of laser welding a connector to the end of the resin tube after the end cutting step; having A manufacturing method for bent resin tubes with connectors.

2. 2. A method for manufacturing a bent resin tube with a connector according to claim 1, a pre-bending welding step of laser-welding the connector to one end of the resin tube before the bending step; and In the welding step, the connector is laser-welded to the other end of the resin tube. A manufacturing method for bent resin tubes with connectors.

3. A method for manufacturing the bent resin tube with connector according to claim 1 or 2, The bending process includes a temporary bending process in which a bending device is used to impart a temporary bend to the resin tube, and a main bending process in which the resin tube is fitted into a mold and the bend is fixed. A manufacturing method for bent resin tubes with connectors.

4. 3. A method for manufacturing a bent resin tube with a connector according to claim 2, a drying step of drying the resin tube and / or the connector before the pre-bending welding step and / or the bending step; having A manufacturing method for bent resin tubes with connectors.

Images