Resin connector connection structure and manufacturing method thereof

Abstract

The resin connector (10) comprises: a cylindrical connector body (11) formed by containing a reinforcing filler in a matrix resin for the body; and a cylindrical connector end portion (12) formed by not containing a reinforcing filler but being formed by a matrix resin for the end portion, or formed by containing a reinforcing filler in a matrix resin for the end portion at a lower ratio than that of the connector body (11), and directly or indirectly joined to the connector body (11) to form the cylindrical end portion of the resin connector (10). A resin tube (20) is formed of a material having a higher laser absorption rate than the connector end portion (12), is embedded in the connector end portion (12), and is welded to the inner peripheral surface or outer peripheral surface of the connector end portion (12), and is also welded to the connector body (11).

Description

Technical Field

[0001] The invention relates to a resin connector connection structure and a manufacturing method thereof. Background Art

[0002] Patent Document 1 describes inserting a tube into a cylindrical band made of plastic that is translucent to laser light, and welding the band and the tube using a laser.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Patent No. 4503966 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] When connecting a resin connector and a resin tube (also called a resin hose or resin piping), laser welding as described in Patent Document 1 is considered. In this case, the resin connector is connected to the resin tube at its first opening and to another connected component at its second opening. To increase the flexural modulus (strength against deformation), this connector contains a filler such as glass fiber in the base resin.

[0008] However, the transmittance of laser light varies depending on the presence or absence of fillers. Furthermore, the transmittance of laser light varies depending on the density of the fillers. Therefore, when laser light is applied to the welded joint between the resin connector and the resin tube, the heat energy generated at the welded joint varies due to the influence of the fillers, potentially leading to variations in joint strength depending on the location.

[0009] The present invention has been made in view of this background and provides a resin connector connection structure and a manufacturing method thereof, which can suppress variations in the joining strength between the resin connector and the resin pipe and ensure the bending modulus of the resin connector.

[0010] Means used to solve problems

[0011] One embodiment of the present invention is a resin connector connection structure, wherein:

[0012] The resin connector connection structure comprises:

[0013] a resin connector formed in a cylindrical shape and having connecting objects connected at both ends; and

[0014] A resin tube, which constitutes one of the connection object members, is formed into a cylindrical shape and is fitted into the first opening side of the resin connector.

[0015] The resin connector comprises:

[0016] The cylindrical connector body is formed by containing a reinforcing filler in a base resin for the body, and

[0017] A cylindrical connector end portion, which does not contain the reinforcing filler and is formed from an end base resin, or is formed so that the reinforcing filler is contained in the end base resin at a lower ratio than that of the connector body portion, and is directly or indirectly joined to the connector body portion, constituting the end portion on the first opening side of the resin connector,

[0018] The resin tube is formed of a material having a higher laser absorption rate than the connector end, is embedded in the connector end, and is welded to the inner circumferential surface or the outer circumferential surface of the connector end, and is welded to a position in the resin connector other than the axial position of the connector main body.

[0019] Another aspect of the present invention is a method for manufacturing a resin connector connection structure.

[0020] A method for manufacturing the above-mentioned resin connector connection structure, wherein:

[0021] In a state where the resin tube is fitted in the connector end, laser light is irradiated from the connector end side in a radial direction, thereby welding radially opposing surfaces of the resin tube and the connector end.

[0022] Effects of the Invention

[0023] According to the above-described resin connector connection structure and manufacturing method, the connector body of the resin connector contains reinforcing filler, thereby having a high flexural modulus. The connector end portion of the resin connector forms the welded portion with the resin tube. The connector end portion does not contain reinforcing filler, or contains a lower proportion of reinforcing filler than the connector body. Consequently, the flexural modulus of the connector end portion is lower than that of the connector body.

[0024] However, high joint strength and minimal variation in joint strength achieved by the fusion of the connector end and the resin tube are more important than a high bending modulus. The connector end does not contain reinforcing filler, or the proportion of reinforcing filler contained in it is lower than that in the connector body. Therefore, the connector end has a higher laser transmittance than the connector body. Furthermore, this can suppress any variation in joint strength between the fusion site between the connector end and the resin tube caused by laser irradiation due to filler.

[0025] In other words, the resin connector functionally separates the connector body from the connector end. Furthermore, the connector body serves as a portion for maintaining a high flexural modulus, while the connector end serves as a portion for ensuring the joint strength achieved through fusion with the resin tube. Therefore, the overall connection structure between the resin connector and the resin tube can suppress variations in the joint strength between the two, while maintaining the resin connector's high flexural modulus.

[0026] In addition, the reference numerals in parentheses in the claims indicate the corresponding relationship with the specific means described in the embodiments described later, and do not limit the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is an axial cross-sectional view showing the resin connector connection structure according to the first embodiment.

[0028] Figure 2 This is a flowchart showing a method for manufacturing the resin connector connection structure according to the first embodiment.

[0029] Figure 3 It is an axial cross-sectional view showing a resin connector connection structure according to a second embodiment.

[0030] Figure 4 It is an axial cross-sectional view showing a resin connector connection structure according to a third embodiment.

[0031] Figure 5 It is an axial cross-sectional view showing a resin connector connection structure according to a fourth embodiment. DETAILED DESCRIPTION

[0032] 1. First Implementation

[0033] 1-1. Structure of Resin Connector Connection Structure 1

[0034] Reference Figure 1 The structure of the resin connector connection structure 1 is described. Figure 1 As shown, a resin connector connection structure 1 includes a resin connector 10, a resin tube 20 (also referred to as a resin hose or resin piping) constituting one of the connected components, and a piping 30 constituting the other of the connected components. The resin connector 10 functions as a member that mediates the connection between the resin tube 20 and the piping 30. Furthermore, the resin connector 10, the resin tube 20, and the piping 30 are each formed into a cylindrical shape for fluid circulation, allowing fluid to flow between the resin tube 20 and the piping 30 via the resin connector 10.

[0035] The resin connector 10 is formed into a cylindrical shape by resin. However, the resin connector 10 is not limited to a straight cylindrical shape, and can also be a curved cylindrical shape. The resin tube 20 and the pipe 30 as the connecting object components are connected to each other at both ends of the cylindrical shape of the resin connector 10. In this embodiment, the resin connector 10 and the resin tube 20 are connected by using a laser B (with Figure 1 On the other hand, the resin connector 10 and the pipe 30 are connected by locking with claws or the like. However, the connection between the resin connector 10 and the pipe 30 is not limited to locking, and they can be connected by any method.

[0036] The resin tube 20 is formed into a long cylindrical shape. The resin tube 20 is formed into a long shape that is at least longer than the resin connector 10. The resin tube 20 is embedded in the first opening side ( Figure 1 on the right side of the Figure 1 In FIG. 1 , the resin tube 20 is shown as being inserted into the inner side of the first opening side of the resin connector 10 , but the resin tube 20 may be attached to the outer side of the first opening side of the resin connector 10 .

[0037] Resin tube 20 is formed from a material with a high absorption rate for laser light B. In other words, resin tube 20 generates heat when irradiated with laser light B. For example, when gasoline is flowing through resin tube 20, it has a multilayer structure, taking into account gasoline resistance, fuel permeation resistance, and weather resistance. Resin tube 20 can be straight or curved.

[0038] The pipe 30 is formed into a cylindrical shape by metal or resin. The pipe 30 is embedded in the second opening side ( Figure 1 In this embodiment, the pipe 30 is inserted into the inner side of the second opening of the resin connector 10, but it can also be embedded outside the second opening of the resin connector 10. In addition, the pipe 30 has an annular flange 31 that protrudes radially outward at a position spaced apart from the front end. The annular flange 31 of the pipe 30 is a portion that is locked to the resin connector 10 along the axial direction of the second opening of the resin connector 10.

[0039] 1-2. Detailed Structure of Resin Connector 10

[0040] Reference Figure 1 The detailed structure of the resin connector 10 will be described. The resin connector 10 includes a connector body 11 and a connector end 12 .

[0041] The connector body 11 is arranged at least in the middle portion of the axial direction of the resin connector 10 (the central axial direction of the cylindrical shape of the resin connector 10). However, in this embodiment, in addition to being arranged in the middle portion of the axial direction of the resin connector 10, the connector body 11 is also arranged in the portion constituting the second opening end. Moreover, the connector body 11 corresponds to a portion having a high bending elastic modulus. In particular, the connector body 11 has a high bending elastic modulus in order to exert sufficient locking force with the piping 30. Here, the resin tube 20 is not welded to the connector body 11. That is, in the resin connector 10, the resin tube 20 is not welded at the axial position where the connector body 11 is located.

[0042] The connector body 11 is formed into a cylindrical shape and is locked to the pipe 30. For example, the connector body 11 includes a locking claw 11a that locks onto the annular flange 31 of the pipe 30. The locking claw 11a elastically deforms to allow insertion of the pipe 30 and then locks onto the annular flange 31 after the pipe 30 is inserted. In other words, the locking claw 11a functions as a member that prevents the pipe 30 from falling out.

[0043] In addition, the connector body 11 has an end ( Figure 1 The right end of the connector 12 has a mating surface 11b for direct engagement with the connector end 12, and a positioning end surface 11c for positioning relative to the resin tube 20 by abutting against the front end surface of the resin tube 20. In this embodiment, the positioning end surface 11c is located radially inward of the mating surface 11b. Furthermore, in this embodiment, the mating surface 11b and the positioning end surface 11c are formed in the same planar shape, but they can also be formed at different axial positions.

[0044] The connector body 11 is required to have strength against deformation in order to be locked with the pipe 30. Therefore, the connector body 11 is formed by containing a reinforcing filler in the base resin for the body.

[0045] The main body base material resin may be, for example, polypropylene, polyamide, polyphenylene sulfide, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polymethylpentene, polyethylene, polyacetal, or a fluororesin. For example, polypropylene having a refractive index of 1.47 to 1.51 may be used. For example, polyamide having a refractive index of 1.51 to 1.55 may be used.

[0046] Reinforcing fillers include glass fiber, carbon fiber, potassium titanate, glass beads, milled fiber, and talc. Since the connector body 11 is not irradiated with the laser light B used for welding, the reinforcing filler used in the connector body 11 does not need to consider the transmittance of the laser light B. Therefore, the reinforcing filler can be applied regardless of the refractive index.

[0047] Furthermore, the resin connector connection structure 1 may include an annular sealing member 40 such as an O-ring between the inner circumference of the connector body 11 and the outer circumference of the pipe 30. The sealing member 40 ensures sealing between the connector body 11 and the pipe 30.

[0048] The connector end portion 12 constitutes the first opening side portion of the resin connector 10, that is, the end portion on the side into which the resin tube 20 is inserted. The connector end portion 12 corresponds to the welded portion with the resin tube 20. The connector end portion 12 is formed into a cylindrical shape.

[0049] In addition, in this embodiment, the connector end portion 12 has a mating surface 11b of the connector body portion 11 and a directly mating mating surface 12a at the axial end portion. The connector end portion 12 is directly joined to the connector body portion 11 by, for example, two-color molding, friction welding, etc. That is, the mating surface 12a of the connector end portion 12 is directly joined to the mating surface 11b of the connector body portion 11. However, the connector end portion 12 may also be indirectly joined to the connector body portion 11 via other components. In addition, the mating surface 12a of the connector end portion 12 is not limited to the axial end portion and can also be set as the outer peripheral surface or the inner peripheral surface.

[0050] Furthermore, the outer and inner circumferential surfaces of the connector end portion 12 are exposed throughout at least a portion in the axial direction. In particular, the outer and inner circumferential surfaces of the portion of the connector end portion 12 facing the first opening of the resin connector 10 are exposed. This means that the connector body 11 is not present in this exposed portion of the connector end portion 12.

[0051] The connector end portion 12 includes a guide portion 12b formed into a tapered shape on the inner circumferential surface of the open end of the connector end portion 12. The maximum inner diameter of the tapered shape in the guide portion 12b is approximately the same as, or slightly larger than, the outer diameter of the distal end portion of the resin tube 20. Furthermore, the minimum inner diameter of the tapered shape in the guide portion 12b is smaller than the outer diameter of the distal end portion of the resin tube 20. Therefore, when the resin tube 20 is inserted into the connector end portion 12, the guide portion 12b contacts the outer circumferential surface of the resin tube 20. Furthermore, the guide portion 12b guides the shrinkage of the resin tube 20.

[0052] Furthermore, the connector end portion 12 is formed adjacent to the guide portion 12b on the inner circumferential surface of the connector end portion 12 and includes a cylindrical inner circumferential surface 12c formed in the shape of a cylindrical inner circumferential surface. The cylindrical inner circumferential surface 12c is formed to extend over the entire axial range between the tapered guide portion 12b and the mating surface 12a directly mated with the connector body portion 11.

[0053] The inner diameter of the cylindrical inner circumferential surface 12c of the connector end 12 coincides with the minimum inner diameter of the guide portion 12b. In other words, the inner diameter of the cylindrical inner circumferential surface 12c is smaller than the outer diameter of the distal end of the resin tube 20. Therefore, the distal end of the resin tube 20 is inserted radially inward of the cylindrical inner circumferential surface 12c in a reduced state. In other words, the cylindrical inner circumferential surface 12c is in close contact with the reduced outer circumferential surface of the resin tube 20.

[0054] The connector end 12 and the resin tube 20 require strong bonding strength. As described above, the connector end 12 and the resin tube 20 are welded and bonded by irradiation with laser light B. Here, the resin tube 20 is formed of a material having a higher absorption rate for the laser light B than the connector end 12.

[0055] Furthermore, for the connector end portion 12, the higher the transmittance of laser light B, the better. Furthermore, the smaller the deviation in the transmittance of laser light B, the better. The higher the transmittance of laser light B, the easier it is to irradiate the welded portion with laser light B. The smaller the deviation in the transmittance of laser light B, the smaller the deviation in the joint strength caused by the weld. In particular, fillers are known to affect the deviation in the transmittance of laser light B. Therefore, the connector end portion 12 is formed so that the matrix resin for the end portion does not contain reinforcing fillers, or the matrix resin for the end portion contains reinforcing fillers at a lower ratio than that of the connector body portion 11.

[0056] When no reinforcing filler is included, the end base material resin may be any resin material that transmits the laser light B. When no reinforcing filler is included, the end base material resin is not affected by the reinforcing filler, and therefore, there is no deviation in the transmittance of the laser light B due to the reinforcing filler. Examples of the end base material resin in this case include polypropylene, polyamide, polyphenylene sulfide, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polymethylpentene, polyethylene, polyacetal, and fluororesin.

[0057] Here, from the perspective of the bonding strength between the connector body 11 and the connector end 12, the main body matrix resin of the connector body 11 and the end matrix resin of the connector end 12 can be the same polymer. However, even if they are different polymers, mechanical or chemical bonding is possible if they have similar melting points and contain functional groups (such as anhydrous maleic acid).

[0058] When reinforcing fillers are included in the connector end 12, they must not impede the transmission of laser light B and must not significantly affect the transmittance of laser light B. Therefore, firstly, it is effective to significantly reduce the reinforcing filler content; secondly, it is also possible to bring the refractive index of the end base resin and the reinforcing filler closer together. For example, the refractive index difference can be within 0.02. However, even when reinforcing fillers with similar refractive indices are used, it is preferable to keep the reinforcing filler content low.

[0059] When reinforcing fillers are included, polypropylene or polyamide is used as the base resin for the end portion. For example, polypropylene with a refractive index of 1.47 to 1.51 is used. For example, polyamide with a refractive index of 1.51 to 1.55 is used.

[0060] Glass fiber fillers are used as reinforcing fillers with a refractive index close to that of the matrix resin used for the end portion. The refractive index of the glass fiber filler is, for example, 1.4 to 1.7. Examples of glass fiber fillers include D glass (low dielectric constant glass), NE glass (acid-resistant alkali glass), A glass (alkali glass), S glass (high-strength, high-elasticity glass), and alkali-resistant glass.

[0061] The connector end 12 and the resin tube 20 are welded by laser B. In this embodiment, the cylindrical inner circumferential surface 12c of the connector end 12 and the outer circumferential surface of the front end of the resin tube 20 are welded. In detail, the welded portion of the connector end 12 and the resin tube 20 is formed into a ring shape that is closed throughout the entire circumference. For example, the welded portion can be formed at multiple positions in the axial direction or at one position in the axial direction. In order to ensure the joint strength brought about by welding, the width of the welded portion can be ensured to be greater than a specified width. In addition, the welded portion formed at multiple positions refers to a plurality of discontinuous annular welded portions.

[0062] The welded portion is located at a position separated from the boundary between the connector body 11 and the connector end 12. In other words, the welded portion does not include the connector body 11. In other words, the resin tube 20 is welded to a position outside the axial position of the connector body 11 within the resin connector 10. In other words, the resin tube 20 is welded to portions of the connector end 12 that are exposed on the outer and inner circumferential surfaces. Furthermore, while the resin tube 20 is welded to the cylindrical inner circumferential surface 12c of the connector end 12, it is not welded to the guide portion 12b.

[0063] 1-3. Manufacturing Method of Resin Connector Connection Structure 1

[0064] Next, refer to Figure 1 as well as Figure 2 The manufacturing method of the resin connector connection structure 1 is described. Figure 2 As shown, the resin connector 10 is manufactured (S1). In this embodiment, the connector body 11 and the connector end 12 are integrally formed by two-color molding. In this way, the connector body 11 and the connector end 12 are directly joined.

[0065] Next, the front end portion of the resin tube 20 is inserted (S2) from the opening (first opening) on ​​the connector end portion 12 side of the resin connector 10. Compared to the relationship between the maximum and minimum inner diameters of the guide portion 12b of the connector end portion 12 and the outer diameter of the front end portion of the resin tube 20, the outer peripheral edge of the front end portion of the resin tube 20 abuts against the guide portion 12b.

[0066] When the resin tube 20 is inserted into the connector end portion 12, the outer peripheral edge of the front end of the resin tube 20 abuts the guide portion 12b while the front end of the resin tube 20 is shrunk. In this shrunk state, the front end of the resin tube 20 is in close contact with the cylindrical inner circumferential surface portion 12c of the connector end portion 12. The resin tube 20 is inserted until the front end of the resin tube 20 abuts the positioning end surface 11c of the connector body 11.

[0067] Next, while the resin tube 20 is embedded (inserted in this embodiment) in the connector end 1, laser B is irradiated radially from the connector end 12 side, i.e., radially outward, to weld the radially opposing surfaces of the connector end 12 and the resin tube 20 (S3).

[0068] The connector end portion 12 is formed of a material that transmits the laser light B, and the resin tube 20 is formed of a material that absorbs the laser light B. Furthermore, in S2, the cylindrical inner circumferential surface portion 12c of the connector end portion 12 is in close contact with the outer circumferential surface of the front end portion of the resin tube 20. The axial portion of the connector end portion 12 that is in close contact with the resin tube 20 corresponds to the portion of the connector end portion 12 that is exposed on the outer and inner circumferential surfaces.

[0069] In this state, laser light B is irradiated from the radially outer side of the connector end portion 12. That is, laser light B is irradiated on the exposed portions of the outer and inner peripheral surfaces of the connector end portion 12 in the resin connector 10. In other words, the portion irradiated with laser light B is a portion of the resin connector 10 that is composed solely of the connector end portion 12 and extends over the entire radial width. As a result, most of the laser light B is transmitted through the connector end portion 12 and generates heat on the facing surfaces (closely contacting surfaces) of the connector end portion 12 and the resin tube 20, thereby fusing the connector end portion 12 and the resin tube 20. In particular, the fusion portions of the connector end portion 12 and the resin tube 20 are formed at multiple locations along the axial direction, and are irradiated with laser light B so as to form a closed ring extending over the entire circumference.

[0070] For example, by irradiating laser B at multiple locations in the axial direction, annular welds having the same width as the irradiation width of laser B can be formed at multiple locations in the axial direction. Alternatively, laser B can be irradiated in a spiral pattern so that the irradiation ranges of laser B partially overlap, thereby forming a single annular weld having an axial length longer than the irradiation width of laser B. Furthermore, if the irradiation width of laser B is greater than a predetermined width for ensuring joint strength, laser B can be irradiated only at one location in the axial direction, thereby forming an annular weld having the same width as the irradiation width of laser B at one location in the axial direction.

[0071] Next, the pipe 30 is inserted into the connector main body 11 (S4). In this way, the resin connector connection structure 1 is manufactured.

[0072] 1-4. Effect

[0073] According to resin connector connection structure 1, connector body 11 of resin connector 10 contains reinforcing filler, resulting in a high flexural modulus. Connector end 12 of resin connector 10 forms a welded portion with resin tube 20. Connector end 12 does not contain reinforcing filler, or contains a lower proportion of reinforcing filler than connector body 11. Therefore, connector end 12 has a lower flexural modulus than connector body 11.

[0074] However, high joint strength and minimal variation in joint strength are required over flexural modulus, resulting from the welding of connector end portion 12 and resin tube 20. Here, connector end portion 12 does not contain reinforcing filler, or contains a lower proportion of reinforcing filler than connector body 11. Therefore, connector end portion 12 has a higher transmittance of laser light B than connector body 11. Furthermore, variations in joint strength at the welded portion between connector end portion 12 and resin tube 20 caused by irradiation with laser light B due to the reinforcing filler can be suppressed.

[0075] That is, the resin connector 10 functionally separates the connector body 11 from the connector end 12. Furthermore, the connector body 11 functions as a portion for maintaining a high flexural modulus, while the connector end 12 functions as a portion for maintaining the joint strength achieved by welding with the resin tube 20. Therefore, the connection structure of the resin connector 10 and the resin tube 20 can suppress variations in the joint strength between the resin connector 10 and the resin tube 20 as a whole, while maintaining the high flexural modulus of the resin connector 10.

[0076] In particular, by excluding reinforcing filler from the connector end 12, variations in the joint strength at the welded portion can be further suppressed. If reinforcing filler is present, its content can be reduced, and the end base resin can have a refractive index close to that of the reinforcing filler.

[0077] Furthermore, the resin tube 20 is inserted radially inwardly of the connector end 12, and the outer circumference of the resin tube 20 is welded to the inner circumference of the connector end 12. This configuration allows for irradiation with the laser B from the radially outer side, simplifying both the equipment and the irradiation with the laser B. In particular, the resin tube 20 can be inserted radially inwardly of the connector end 12 in a shrunken state. This improves the close contact between the resin tube 20 and the connector end 12, facilitating welding with the laser B and suppressing variations in joint strength.

[0078] Furthermore, the welded portion is the cylindrical inner circumferential surface portion 12c of the connector end portion 12, not the tapered guide portion 12b. If the tapered guide portion 12b were used as the welded portion, the radial thickness of the connector end portion 12 would vary in the axial direction, and the heat energy generated by irradiation with laser light B would likely vary depending on the location. However, by using the cylindrical inner circumferential surface portion 12c as the welded portion, variations in joint strength can be suppressed.

[0079] Furthermore, the welded portion is located away from the boundary between the connector body 11 and the connector end 12. This prevents the laser beam B from being affected by the reinforcing filler contained in the connector body, thereby suppressing variations in the joint strength.

[0080] Furthermore, the welded portion is formed in a closed ring shape throughout the entire circumference. This ensures a seal between the connector end 12 and the resin tube 20. Furthermore, multiple welded portions are formed along the axial direction. This ensures high joint strength and a strong seal.

[0081] 2. Second Implementation

[0082] Reference Figure 3 A resin connector connection structure 2 according to a second embodiment will now be described. Resin connector connection structure 2 of this embodiment differs from resin connector connection structure 1 of the first embodiment in the connector body 51 and the connector end 52. However, in resin connector connection structure 2, components identical to those of resin connector connection structure 1 of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0083] The connector body 51 includes a cylindrical body jaw portion 51b extending along the side of the connector end portion 52. The body jaw portion 51b protrudes axially from the radially outer portion of the axial end surface. Surface 51c constitutes a joint surface for direct connection with the connector end portion 52, and the surface 51c has the axial end surface of the body jaw portion 51b, the inner peripheral surface of the body jaw portion 51b, and the axial direction of the base of the body jaw portion 51b as normal lines. In other words, the joint surface is formed in a stepped shape. The connector body 51 includes a positioning end surface 51d having an axial normal line on the radial inner side of the body jaw portion 51b. In this embodiment, the surface 51c and the positioning end surface 51d are located on the same plane.

[0084] The connector end portion 52 includes a cylindrical end jaw portion 52a extending toward the connector body 51. The end jaw portion 52a protrudes axially from the radially inner portion of the axial end surface. A surface 52b forms a joint surface for direct engagement with the connector body 51. This surface 52b has its normals oriented to the axial end surface, the outer circumference, and the axial direction of the base of the end jaw portion 52a. In other words, this joint surface is formed in a stepped shape.

[0085] According to this embodiment, the area of ​​the joint surface between the connector main body 51 and the connector end 52 can be increased. Therefore, the joint strength between the connector main body 51 and the connector end 52 can be improved.

[0086] Here, the welded portion is a portion of the connector end portion 52 that is closer to the open end of the connector end portion 52 (the first opening side of the resin connector 10) than the end jaw portion 52a. In other words, the portion irradiated with the laser beam B is a portion of the resin connector 10 consisting solely of the connector end portion 52 over the entire radial width.

[0087] 3. Third Implementation

[0088] Reference Figure 4 The resin connector connection structure 3 of the third embodiment will be described. The resin connector connection structure 3 includes a resin connector 60, a first resin tube 70, and a second resin tube 80. The resin connector 60 includes a connector body 61, a first opening side ( Figure 4 The first connector end portion 62 on the right side of the resin connector 60 and the second opening side ( Figure 4 ) on the left side of the second connector end 63.

[0089] The connector body 61 needs a bending elastic modulus for fixing to an object member. The first connector end 62 and one end of the connector body 61 in the axial direction ( Figure 4 The second connector end portion 63 is directly connected to the other axial end ( Figure 4The left end of the connector body 61 is directly joined to the left end of the connector body 62. In this way, the connector body 61, the first connector end 62, and the second connector end 63 are integrally formed. The first connector end 62 is joined to the first resin tube 70 by welding using laser B. The second connector end 63 is joined to the second resin tube 80 by welding using laser B.

[0090] Here, the first connector end portion 62 and the first resin tube 70, and the second connector end portion 63 and the second resin tube 80 are substantially the same as those between the connector end portion 12 and the resin tube 20 in the first embodiment. Figure 4 In the figure, the reference numerals of the respective parts in the first embodiment are marked.

[0091] 4. Fourth embodiment

[0092] Reference Figure 5 A resin connector connection structure 4 according to a fourth embodiment will be described. In the following description, components of the resin connector connection structure 4 identical to those of the resin connector connection structure 3 according to the third embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0093] The resin connector connection structure 4 includes a resin connector 90, a first resin tube 70, and a second resin tube 80. The resin connector 90 includes a connector body 91, a low-strength intermediate portion 92, and a first opening side ( Figure 5 The first connector end portion 93 on the right side of the resin connector 90 and the second opening side ( Figure 5 ) on the left side of the second connector end 94.

[0094] Connector body 91 is formed into a cylindrical shape and constitutes the outer layer of the axially intermediate portion of resin connector 90. Connector body 91 requires a sufficient flexural modulus for securing to a mating member, for example. Therefore, connector body 91 is formed by incorporating reinforcing fillers into the base resin of the body.

[0095] The low-strength middle portion 92 is formed into a cylindrical shape and constitutes the inner layer of the middle portion in the axial direction of the resin connector 90. The low-strength middle portion 92 is directly bonded to the inner peripheral surface of the connector body portion 91. The low-strength middle portion 92 has a first opening side ( Figure 5 The positioning end face 92a is normal to the right side of the second opening ( Figure 5 The positioning end surface 92a is positioned relative to the first resin tube 70 by contacting the front end surface of the first resin tube 70. The positioning end surface 92b is positioned relative to the second resin tube 80 by contacting the front end surface of the second resin tube 80.

[0096] The low-strength intermediate portion 92 does not need to have a high flexural modulus like the connector body 91; it only needs to maintain the shape of the positioning end faces 92a and 92b. Therefore, the low-strength intermediate portion 92 is formed so that the matrix resin does not contain reinforcing filler, or the matrix resin contains a lower proportion of reinforcing filler than the connector body 91.

[0097] The first connector end portion 93 is formed in a cylindrical shape and is integrally formed at one axial end ( Figure 5 In this embodiment, for example, the first connector end portion 93 can be integrally formed with the low-strength middle portion 92 by injection molding or the like. However, the first connector end portion 93 can also be formed of a different material from the low-strength middle portion 92 and joined thereto.

[0098] Here, the first connector end portion 93 is configured similarly to the first connector end portion 62 in the third embodiment. Therefore, the first connector end portion 93 is joined to the first resin tube 70 by welding using laser light B.

[0099] The second connector end portion 94 is formed in a cylindrical shape and is integrally formed at the other axial end ( Figure 5 In this embodiment, for example, the second connector end portion 94 can be integrally formed with the low-strength middle portion 92 by injection molding or the like. However, the second connector end portion 94 can also be formed of a different material from the low-strength middle portion 92 and joined thereto.

[0100] Here, the second connector end portion 94 is configured similarly to the second connector end portion 63 in the third embodiment. Therefore, the second connector end portion 94 is joined to the second resin tube 80 by welding using laser light B.

[0101] In this embodiment, the first connector end portion 93 is arranged to be continuous with the low-strength intermediate portion 92 and connected to the connector body 91 via the low-strength intermediate portion 92. That is, the first connector end portion 93 is directly joined only to the low-strength intermediate portion 92, and not directly joined to the connector body 91. Therefore, the first connector end portion 93 is indirectly joined to the connector body 91 via the low-strength intermediate portion 92. Furthermore, the first connector end portion 93 may be directly joined to both the connector body 91 and the low-strength intermediate portion 92, or may be directly joined only to the connector body 91.

[0102] Similarly, in this embodiment, the second connector end portion 94 is arranged to be continuous with the low-strength intermediate portion 92 and connected to the connector body 91 via the low-strength intermediate portion 92. That is, the second connector end portion 94 is directly joined only to the low-strength intermediate portion 92, and not directly joined to the connector body 91. Therefore, the second connector end portion 94 is indirectly joined to the connector body 91 via the low-strength intermediate portion 92. Furthermore, the second connector end portion 94 may be directly joined to both the connector body 91 and the low-strength intermediate portion 92, or may be directly joined only to the connector body 91.

[0103] This embodiment also achieves the same effects as the third embodiment. Furthermore, since the volume of the connector body 91 can be reduced, costs can be reduced. Furthermore, when the low-strength intermediate portion 92, the first connector end portion 93, and the second connector end portion 94 are integrally formed by injection molding or the like, the area of ​​the joining surface between the integrally formed body and the connector body 91 can be increased. Consequently, the joining strength between the connector body 91 and the integrally formed body, specifically the joining strength between the connector body 91 and the connector ends 93 and 94, can be increased.

[0104] 5. Others

[0105] In the first embodiment, the connector end 12 and the resin tube 20 are welded together by irradiating the laser beam B from the radially outer side with the resin tube 20 inserted inside the connector end 12. Alternatively, the connector end 12 and the resin tube 20 are welded together by irradiating the laser beam B from the radially inner side, i.e., in the radial direction, with the resin tube 20 fitted outside the connector end 12.

[0106] In the first embodiment, the connector body 11 is configured to include claws that engage with the pipe 30. Alternatively, the following configuration may be employed: Multiple radially protruding annular projections may be formed on the outer circumference of the connector body 11. The pipe 30 may be fitted onto the outer circumference of the connector body 11 by expanding the pipe, and then engaged axially with the multiple annular projections.

[0107] In the fourth embodiment, the resin connector 90 is configured to include the low-strength intermediate portion 92. In the first and second embodiments, a member corresponding to the low-strength intermediate portion 92 may be provided.

Claims

1. A resin connector connection structure (1, 2, 3, 4), wherein: The resin connector connection structure (1, 2, 3, 4) comprises: A resin connector (10, 60, 90) is formed into a cylindrical shape and has connecting object members (20, 30, 70, 80) connected at both opening ends thereof; and A resin tube (20, 70, 80) constituting one of the connection object members is formed into a cylindrical shape and is embedded in the first opening side of the resin connector. The resin connector comprises: A cylindrical connector body (11, 51, 61, 91) is formed by including a reinforcing filler in a base resin for the body; and A cylindrical connector end portion (12, 52, 62, 63, 93, 94) is formed of an end base resin without containing the reinforcing filler, or is formed so that the reinforcing filler is contained in the end base resin at a lower ratio than that of the connector body portion, and is directly or indirectly joined to the connector body portion, constituting the end portion on the first opening side of the resin connector. The resin tube is formed of a material having a higher laser absorption rate than the connector end portion, is embedded in the connector end portion, and is welded to the inner circumferential surface or the outer circumferential surface of the connector end portion, and is welded to a position in the resin connector other than the axial position of the connector main body portion. In the resin connector, the outer peripheral surface and the inner peripheral surface of the connector end portion are exposed over the entire circumference in at least a portion in the axial direction.

2. The resin connector connection structure (1, 2, 3, 4) according to claim 1, wherein: The connector end portion does not contain the reinforcing filler.

3. The resin connector connection structure (1, 2, 3, 4) according to claim 1 or 2, wherein: The resin tube is inserted radially inward of the connector end portion, and an outer peripheral surface thereof is welded to an inner peripheral surface of the connector end portion.

4. The resin connector connection structure (1, 2, 3, 4) according to claim 3, wherein: The resin tube is inserted radially inward of the connector end portion in a shrunk state.

5. The resin connector connection structure (1, 2, 3, 4) according to claim 4, wherein: The connector end has: A guide portion (12b) formed in a tapered shape on the inner peripheral surface of the open end of the connector end portion to guide the shrinkage of the resin tube; and a cylindrical inner peripheral surface portion (12c) formed on the inner peripheral surface of the connector end portion so as to be adjacent to the guide portion and formed in the shape of a cylindrical inner peripheral surface, The resin tube is welded to the cylindrical inner peripheral surface portion of the connector end portion and is not welded to the guide portion.

6. The resin connector connection structure (1, 2, 3, 4) according to claim 1 or 2, wherein: A welded portion between the resin tube and the connector end portion is located at a position separated from a boundary portion between the connector main body portion and the connector end portion.

7. The resin connector connection structure (1, 2, 3, 4) according to claim 1 or 2, wherein: The welded portion between the resin tube and the connector end is formed in a closed ring shape over the entire circumference.

8. The resin connector connection structure (1, 2, 3, 4) according to claim 1 or 2, wherein: The main body base material resin and the end portion base material resin are the same polymer.

9. A method for manufacturing a resin connector connection structure, which is a method for manufacturing the resin connector connection structure (1, 2, 3, 4) according to any one of claims 1 to 8, wherein: When the resin tube (20, 70, 80) is embedded in the connector end (12, 52, 62, 63, 93, 94), laser light is irradiated radially from the connector end side, thereby welding radially opposing surfaces of the resin tube and the connector end (S3).

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