JP2020179556A - Structure and manufacturing method of same - Google Patents

Abstract

To provide a structure in which hollow cylindrical tubular members formed of a resin are firmly and highly accurately joined to each other by a simple method without using an adhesive, and a manufacturing method for the same.SOLUTION: In a structure in which hollow cylindrical first tubular member and second tubular member are joined, the first tubular member contains a first resin material capable of transmitting laser light, and the second tubular member contains a second resin material capable of absorbing laser light. The first tubular member is inserted into the second tubular member so that an inner peripheral surface of an end region of the second tubular member overlaps an outer peripheral surface of an end region of the first tubular member. The outer peripheral surface of the end region of the first tubular member and the inner peripheral surface of the end region of the second tubular member are welded by a laser weld formed so as to orbit with a predetermined width.SELECTED DRAWING: Figure 1

Description

The present invention relates to a structure in which hollow cylindrical tubular members are joined to each other, and a method for manufacturing the same.

Conventionally, when joining cylindrical resin pipes to each other, it is common to use an adhesive for resin bonding. For example, when connecting a flexible pipe made of soft vinyl chloride and a socket made of hard vinyl chloride into which an end portion of the flexible pipe can be inserted, they are joined using a urethane-based adhesive.

However, from a resin containing a large amount of plasticizer such as soft vinyl chloride, there is a problem that the plasticizer elutes with time and the bonding strength tends to decrease due to the eluted plasticizer.

In order to solve these problems, for example, the sleeve of the socket is provided with a convex portion, the flexible tube is provided with a concave portion, and the concave portion of the flexible tube is fitted to the convex portion, and the adhesive is used. A method of joining the socket and the flexible pipe can be considered. For example, in Patent Document 1, an annular recess is formed in a pipe joint connecting a hose, and a connecting ring that can be bonded with an adhesive is used with the end of the hose inserted in the annular recess to form a hose. The connection structure to be joined is disclosed.

Japanese Unexamined Patent Publication No. 11-37378

However, even with the hose connection structure disclosed in Patent Document 1, an adhesive is still used for joining the socket and the flexible pipe, and the adhesive is used during the insertion of the hose into the annular recess of the pipe joint. It was not always possible to completely solve problems such as insufficient bonding strength and uneven overall length after bonding when the hose solidified. In addition, if an adhesive is used for bonding, it is necessary to improve the working environment when performing the bonding work, such as requiring ventilation equipment for volatilization of the solvent contained in the adhesive.

The present invention has been made in consideration of such circumstances, and the hollow cylindrical tubular members formed of resin can be firmly and highly accurately formed by a simple method without using an adhesive. It is an object of the present invention to provide a structure joined to the above, and a method for producing the same.

In order to solve the above problems, the present invention proposes the following means.
That is, the structure of the present invention is a structure in which a hollow cylindrical first tubular member and a second tubular member are joined, and the first tubular member is a first resin capable of transmitting laser light. The second tubular member contains a second resin material capable of absorbing laser light, and the outer peripheral surface of the end region of the first tubular member has an end region of the second tubular member. The first tubular member is inserted into the second tubular member so that the inner peripheral surfaces overlap, and the outer peripheral surface of the end region of the first tubular member and the end region of the second tubular member are overlapped. The inner peripheral surface of the above is characterized in that it is welded by a laser welding portion formed so as to orbit in a predetermined width.

Further, in the present invention, the second tubular member may be a flexible tube that can be flexed.

Further, in the present invention, the second tubular member may have heat shrinkage.

Further, in the present invention, the second resin material may contain at least a soft vinyl chloride resin.

The method for manufacturing a structure of the present invention is the method for manufacturing a structure according to each of the above items, wherein the end region of the second tubular member is formed on the outer peripheral surface of the end region of the first tubular member. The insertion step of inserting the first tubular member into the second tubular member and the inner peripheral surface of the second tubular member from the inside of the first tubular member so as to overlap the inner peripheral surfaces. By irradiating the laser beam as described above, the outer peripheral surface of the end region of the first tubular member and the inner peripheral surface of the end region of the second tubular member are welded so as to orbit in a predetermined width. It is characterized by including at least a laser light welding step of forming a laser welded portion.

Further, in the present invention, which is a pre-process of the insertion step, the outer peripheral surface of the end region of the first tubular member or the inner peripheral surface of the end region of the second tubular member is at least one of them. , The lubricant coating step of applying the lubricant may be further provided.

Further, in the present invention, it is a pre-process of the insertion step, and is on at least one of the outer peripheral surface of the end region of the first tubular member or the inner peripheral surface of the end region of the second tubular member. A resin paste application step of applying a resin paste that fills the irregularities formed on the outer peripheral surface or the inner peripheral surface may be further provided.

Further, in the present invention, in the laser light welding step, laser light may be irradiated so as to orbit the inner peripheral surface of the second tubular member a plurality of times.

According to the present invention, there is provided a structure in which hollow cylindrical tubular members formed of resin are joined to each other firmly and with high precision by a simple method without using an adhesive, and a method for manufacturing the same. can do.

It is sectional drawing along the central axis of the structure which is one Embodiment of this invention. It is sectional drawing which is perpendicular to the central axis of the structure which is one Embodiment of this invention. It is sectional drawing which showed the manufacturing method of the structure which is one Embodiment of this invention step by step. It is a photograph which shows the result of the verification example. It is a photograph which shows the result of the verification example. It is a perspective view which shows an example of the laser welding apparatus which can be applied to the laser light welding process of this embodiment.

Hereinafter, the structure of one embodiment of the present invention and the manufacturing method thereof will be described with reference to the drawings. It should be noted that each of the following embodiments is specifically described in order to better understand the gist of the invention, and is not limited to the present invention unless otherwise specified. Further, in the drawings used in the following description, in order to make the features of the present invention easy to understand, the main parts may be enlarged for convenience, and the dimensional ratios of the respective components are the same as the actual ones. Is not always the case.

(Structure)
FIG. 1 is a cross-sectional view taken along the central axis of the structure according to the embodiment of the present invention. Further, FIG. 2 is a cross-sectional view perpendicular to the central axis of the structure according to the embodiment of the present invention.
The structure 10 of the present embodiment is formed by joining a socket (first tubular member) 11 and a flexible pipe (second tubular member) 12.

The socket (first tubular member) 11 is formed in a hollow cylindrical shape, and is formed of a first resin material capable of transmitting laser light used when forming the laser welding portion 14 described later in one end region E1. ing. Examples of such a first resin material include a transparent hard vinyl chloride resin.

The flexible tube (second tubular member) 12 is formed, for example, in a bellows shape around it, and is flexible in any direction. One end region E2 of such a flexible tube 12 is formed in a hollow cylindrical shape. One end region E2 of the flexible tube 12 is made capable of inserting one end region E1 of the socket 11 inside. That is, the structure 10 of the present embodiment has the socket 11 and the flexible pipe 12 so that the inner diameter φ2 in the end region E2 of the flexible pipe 12 is larger than the outer diameter φ1 in the end region E1 of the socket 11. Is formed. The structure 10 is configured such that the outer peripheral surface 11a of the end region E1 of the socket 11 overlaps the inner peripheral surface 12a of the end region E2 of the flexible pipe 12.

The flexible tube (second tubular member) 12 has at least an end region E2 formed of a second resin material capable of absorbing laser light used when forming the laser welding portion 14 described later. Examples of the second resin material include an opaque soft vinyl chloride resin. The soft vinyl chloride resin is a thermosetting resin, and in the present embodiment, the inner diameter φ2 of the flexible tube 12 is reduced by raising the temperature to a predetermined temperature or higher by heating. Here, "capable of absorbing laser light" means a state in which when the laser light is irradiated, the energy becomes heat and the second resin material constituting the flexible tube 12 is heated to raise the temperature.

In the present embodiment, the outer diameter φ1 in the end region E1 of the socket 11 is, for example, about 80 mm to 120 mm. Further, the inner diameter φ2 in the end region E2 of the flexible pipe 12 is, for example, about 80 mm to 120 mm. The gap Δ1 (see FIG. 3) between the outer peripheral surface 11a in the end region E1 of the socket 11 and the inner peripheral surface 12a in the end region E2 of the flexible pipe 12 before joining is, for example, Excluding local unevenness, it exists in a range of 0.0 mm to a maximum of about 1.3 mm.

The outer peripheral surface 11a of the end region E1 of the socket (first tubular member) 11 and the inner peripheral surface 12a of the end region E2 of the flexible pipe (second tubular member) 12 rotate with a predetermined width W. It is welded by the laser welding portion 14 formed so as to perform the welding.

The laser welding portion 14 is melted in a strip shape with a predetermined width W so as to orbit the inner peripheral surface 12a of the flexible tube (second tubular member) 12, and the outer peripheral surface of the socket (first tubular member) 11 is formed. This is the portion welded to 11a. The laser welding portion 14 is a portion where the inner diameter φ2 of the flexible tube 12 is reduced by melting a part of the thermosetting resin (soft vinyl chloride resin) constituting the flexible tube 12.

Then, by forming the socket 11 and the flexible tube 12 with a hard vinyl chloride resin and a soft vinyl chloride resin whose structures are similar to each other, the socket 11 and the flexible tube 12 are formed in the laser welding portion 14. It is integrated and firmly joined. Such a laser welding portion 14 is formed by irradiation with laser light, as will be described later.

According to the structure 10 of the present embodiment having the above configuration, the hollow cylindrical socket (first tubular member) 11 and the flexible tube (second tubular member) 12 formed of resin are formed. It has a laser welded portion 14 formed by melting a part by irradiation with a laser beam. As a result, the socket (first tubular member) 11 and the flexible tube (second tubular member) 12 are joined more firmly and with high precision than when they are bonded with an adhesive, and the durability is high. A tall structure 10 can be realized.

In the above-described embodiment, the socket 11 is exemplified as an example of the first tubular member, and the flexible tube 12 is exemplified as an example of the second tubular member, but the first tubular member and the second tubular member are exemplified. Is not limited to this, and any hollow cylindrical member may be used.

Further, in the above-described embodiment, a transparent hard vinyl chloride resin is used as the first resin material constituting the socket (first tubular member) 11, and a second flexible tube (second tubular member) 12 is formed. Although opaque soft vinyl chloride resin has been exemplified as the resin material, the first resin material and the second resin material are not limited to these, and the first resin material is a resin capable of transmitting laser light and a second resin. The material may be a resin capable of absorbing laser light.

Further, in the above-described embodiment, a method of applying the shrinkage property of the resin material to the joining of the pipes is described. Can be used for. In this case, a part of the tubular member is formed so as to intentionally leave residual stress such as bending or tightness. At the time of joining, the portion where the residual stress remains is irradiated with a laser beam, and the residual stress is released by using the absorption of the laser beam as a trigger. As a result, the member whose residual stress is released contracts, so that the pipes can be joined to each other. There are various molding methods for intentionally forming such residual stress, and for example, blow molding and the like can be applied.

Further, in the above-described embodiment, the structure 10 in which the socket (first tubular member) 11 and the flexible tube (second tubular member) 12 are joined by the laser welding portion 14 has been illustrated. In addition to the above, for example, in addition to the first tubular member and the second tubular member, another tubular member may be joined.

(Manufacturing method of structure)
Next, a method of manufacturing a structure having the above-described configuration will be described.
FIG. 3 is a cross-sectional view showing stepwise a method for manufacturing a structure according to an embodiment of the present invention.
When manufacturing the structure 10 shown in FIGS. 1 and 2, first, the end region E1 of the socket (first tubular member) 11 is set to the end region of the flexible pipe (second tubular member) 12. It is inserted inside E2 (insertion step: see FIG. 3A). As a result, the inner peripheral surface 12a of the flexible pipe 12 overlaps the outer peripheral surface 11a of the socket 11.

When the gap Δ1 between the outer diameter φ1 of the socket 11 and the inner diameter φ2 of the flexible tube 12 is small, the outer peripheral surface 11a of the end region E1 of the socket 11 prior to the above-mentioned insertion step, Alternatively, a lubricant coating step of applying the lubricant to at least one of the inner peripheral surfaces 12a of the end region E2 of the flexible pipe 12 may be performed.

In this lubricant coating step, a semi-solid or liquid lubricant that reduces friction is applied in advance to the outer peripheral surface 11a of the socket 11 and the inner peripheral surface 12a of the flexible pipe 12. As the lubricant used in the lubricant coating step, for example, V soap (registered trademark: manufactured by Kubota-Chemix Co., Ltd.) or the like can be used.

As a result, even when the gap Δ1 between the outer diameter φ1 of the socket 11 and the inner diameter φ2 of the flexible tube 12 is small, the end region E1 of the socket 11 is inserted into the flexible tube 12 in the insertion step. It can be easily inserted into the end region E2.

If the outer peripheral surface 11a of the socket 11 or the inner peripheral surface 12a of the flexible tube 12 has irregularities, a resin paste that fills the irregularities is applied to the outer peripheral surface 11a of the socket 11 or the inner peripheral surface 12a of the flexible tube 12. The resin paste coating step of coating may be performed.

In this resin paste coating step, the resin paste is solidified by the laser beam irradiated in the laser light welding step, which is a subsequent step, and can be integrated with the first resin constituting the socket 11 and the second resin constituting the flexible tube 12. A paste sol of 1 resin or a paste sol of 2nd resin can also be used as a lubricant. For example, in the present embodiment, a vinyl chloride resin paste sol agent obtained by solizing the same resin as the second resin constituting the flexible tube 12 can be used. By applying such a vinyl chloride resin paste sol agent, not only the insertability of the flexible tube 12 is improved by reducing friction, but also the inner peripheral surface 12a of the flexible tube 12 or the outer peripheral surface 11a of the socket 11 is uneven. Even if it is flattened, the bonding strength can be further increased.

Next, a laser beam is irradiated from the inside of the socket (first tubular member) 11 so as to orbit the inner peripheral surface 12a of the flexible tube (second tubular member) 12, and the end region E1 of the socket 11 is irradiated. A laser welded portion 14 is formed by welding the outer peripheral surface 11a and the inner peripheral surface 12a of the end region E2 of the flexible tube 12 so as to orbit with a predetermined width W (laser light welding step: FIG. 3 (Fig. 3). b) See).

In this laser light welding step, the cylindrical socket (first tubular member) 11 and the flexible tube (second tubular member) 12 are rotated to emit the laser light L from the inside of the socket 11 to the inside of the socket 11. Irradiate toward the peripheral surface 11b. As a result, the laser beam L is irradiated along the circumferential direction of the inner peripheral surface 11b of the socket 11. As the laser light used for welding, for example, infrared laser light having a wavelength in the range of 800 nm to 1100 nm, which is slightly longer than visible light, is preferable. Examples of the laser device include a diode laser and a YAG laser.

When such a laser beam L is irradiated from the inside of the socket 11 toward the inner peripheral surface 11b of the socket 11, the socket 11 is formed of a transparent hard vinyl chloride resin (first resin material) capable of transmitting the laser beam. Therefore, the irradiated laser beam L transmits the socket 11 from the inner peripheral surface 11b toward the outer peripheral surface 11a, and is incident on the inner peripheral surface 12a of the flexible tube 12.

Since the flexible tube 12 is formed of an opaque soft vinyl chloride resin (second resin material) capable of absorbing laser light, the laser light L incident on the inner peripheral surface 12a of the flexible tube 12 is flexible here. It is absorbed by the tube 12 and the irradiated portion of the laser beam L generates heat. Then, the irradiated portion of the laser beam L in the flexible tube 12 melts. Further, the portion of the flexible tube 12 irradiated with the laser beam L contracts due to heat generation.

As a result, the inner diameter φ2 of the flexible pipe 12 is reduced in diameter due to heat shrinkage of the soft vinyl chloride resin, and the gap (gap) Δ1 between the outer peripheral surface 11a of the socket 11 and the inner peripheral surface 12a of the flexible pipe 12 is eliminated. .. Then, the soft vinyl chloride resin melted by the irradiation of the laser beam L in the flexible tube 12 is fused and integrated with the hard vinyl chloride resin constituting the socket 11, and the laser welded portion 14 is formed.

Then, when the laser beam L is irradiated so as to orbit the inner peripheral surface 11b of the socket 11, the outer peripheral surface 11a of the end region E1 of the socket 11 and the inner peripheral surface 12a of the end region E2 of the flexible tube 12 are irradiated. A laser welded portion 14 orbiting with a predetermined width W is formed (see FIG. 3C).

FIG. 6 shows an example of a laser welding apparatus applicable to the laser light welding step of the present embodiment.
The laser welding device M has a hollow cylindrical shape capable of holding the socket (first tubular member) 11 and the flexible tube (second tubular member) 12 from the laser light oscillating unit 101 and the laser light oscillating unit 101 side. A work fixing jig 102 and a work rotating jig 103 for rotating the work fixing jig 102 around the central axis C are provided.

The laser light oscillator 101 is mainly composed of a rod-shaped optical head 104 connected to a light source (not shown) and a plate-shaped optical head support 105 that supports the optical head 104. The optical head support portion 105 has an opening 105a through which the optical head 104 is inserted.

The optical head 104 includes an insertion portion 106 inserted into the socket (first tubular member) 11 and the flexible tube (second tubular member) 12, and a mirror (reflection) attached to the tip portion of the insertion portion 106. It has a laser light guiding unit 108 including a member) 107. The tip portion of the insertion portion 106 is bent at an angle of, for example, 45 ° with respect to the extension direction of the rotation center axis C of the socket (first tubular member) 11 and the flexible tube (second tubular member) 12. ..

As a result, the reflection surface of the mirror (reflection member) 107 is fixed at an angle of, for example, 45 ° with respect to the extension direction of the rotation center axis C. Then, the laser beam L emitted from the optical head 104 along the extension direction of the rotation center axis C is reflected by the mirror (reflection member) 107 toward the inner peripheral surface 12a of the flexible tube 12.

The socket 11 and the flexible tube 12 are fixed inside such a cylindrical work fixing jig 102, the work fixing jig 102 is rotated by the work rotating jig 103, and a laser is used from the optical head 104 via the mirror 107. By irradiating the light L toward the inner peripheral surface 12a of the flexible tube 12, the outer peripheral surface 11a of the end region E1 of the socket 11 and the inner peripheral surface 12a of the end region E2 of the flexible tube 12 are fused. , The laser welding portion 14 is formed along the laser irradiation interface that orbits with a predetermined width W (see FIG. 2).

In the above-mentioned laser welding step, the structure in which the socket 11 and the flexible tube 12 are integrally rotated to irradiate the inner peripheral surface of these with laser light has been described. , A laser beam is introduced inside the socket 11 and the flexible tube 12, and the laser beam itself is scanned along the inner peripheral surface of the socket 11 and the flexible tube 12 to form a laser welded portion 14. You can also. For example, a laser head capable of irradiating a laser beam is arranged in the space inside the socket 11 and the flexible tube 12, and the laser head itself is used as the socket (first tubular member) 11 and the flexible tube (second). It is also possible to rotate the inside of the tubular member (12) 12 along the circumferential direction, or to scan the laser beam emitted by the rotating mirror along the inner peripheral surface 11b of the socket 11.

According to the method for manufacturing the structure of the present embodiment, the socket (first tubular member) 11 and the flexible tube (second tubular member) 12 are fused using laser light, as in the conventional case. There is no need for large-scale ventilation equipment in the work environment, which is necessary when adhering to the laser with an adhesive, and the socket (first tubular member) 11 and the flexible pipe (second tubular member) 12 are joined. It is possible to improve the production efficiency of the process and the working environment.

Further, if the flexible tube (second tubular member) 12 is formed of a thermosetting resin, the diameter of the flexible tube 12 can be reduced by heat generated by irradiation with laser light. As a result, in the insertion step, the gap Δ1 between the socket 11 and the flexible tube 12 can be increased to facilitate insertion, and in the laser light welding step, such a gap Δ1 is eliminated and the socket 11 and the flexible tube 12 are brought into close contact with each other. Therefore, the socket 11 and the flexible tube 12 can be reliably and firmly joined by the laser welding portion 14.

Further, if the socket (first tubular member) 11 is made of a hard vinyl chloride resin and the flexible tube (second tubular member) 12 is made of a soft vinyl chloride resin, the compatibility is high because both are vinyl chloride resins. Therefore, laser welding can be easily performed.

In the present embodiment, the width W of the laser welding portion 14, which is the portion where the socket (first tubular member) 11 and the flexible tube (second tubular member) 12 are welded, is the end portion of the socket 11. Although it is made smaller than the region E1 and the end region E2 of the flexible tube 12, the laser welding portion 14 may be formed so that the end region E1 and the end region E2 are welded over the entire area.

Further, the orbital speed and the number of orbits of the laser beam L inside the socket (first tubular member) 11 are arbitrary at any speed so that the socket 11 and the flexible tube 12 are surely welded. The laser beam L may be irradiated with the number of laps. Further, in order to form the laser welded portion 14 having the set width W, the laser beam L can be scanned parallel to the axial direction of the socket (first tubular member) 11.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention as well as the invention described in the claims and the equivalent scope thereof.

In the method for producing a structure of the present invention, the effect of using a lubricant was verified.
In the verification, as an example, the following two types of lubricants (resin paste sol) were used, and a flexible tube (second tubular member) was inserted into the socket (first tubular member). Further, as a comparative example, a flexible tube (second tubular member) was inserted into the socket (first tubular member) without using a lubricant.

Resin paste sol 1: Polyvinyl chloride 40-50%, bis (2-ethylhexyl) phthalate 37%, calcium carbonate 10-20%
Resin paste sol 2: Polyvinyl chloride 50-60%, non-phthalic acid plasticizer 40-50%
Outer diameter of socket: 100 mm
Inner diameter of flexible tube (maximum): Molded so that the outer diameter of a socket of 100 mm can be inserted Laser light source: L13920-511 manufactured by Hamamatsu Photonics Co., Ltd., Irradiation output: 34A (≈55W) Rotation setting: 29.3 ( ≈120 rpm), number of irradiations: 5, spot diameter: φ3.2 mm, irradiation pitch: 5 mm

FIG. 4 shows the insertion results of Example 1 and Comparative Example. FIG. 5 shows photographs of the laser beam irradiation unit of Example 1 and Example 2.

According to the results shown in FIG. 4, in the comparative example in which the resin paste sol was not applied, the flexible tube could not be inserted to the end of the socket due to friction with each other. On the other hand, in Example 1 in which the resin paste sol was applied, the flexible tube could be inserted up to the end of the socket. It was confirmed that the flexible tube can be easily inserted into the socket by applying a lubricant (resin paste sol).

Further, according to the result of FIG. 5, it was confirmed that by applying the resin paste sol, the gap between the socket and the flexible tube can be filled and solidified by the heat of laser welding. As a result, the unevenness of the flexible pipe can be eliminated and the joint strength can be improved.

10 ... Structure 11 ... Socket (first tubular member)
12 ... Flexible pipe (second tubular member)
14 ... Laser welding part

Claims (8)

It is a structure in which a hollow cylindrical first tubular member and a second tubular member are joined.
The first tubular member contains a first resin material capable of transmitting laser light.
The second tubular member contains a second resin material capable of absorbing laser light.
The first tubular member is inserted into the second tubular member so that the inner peripheral surface of the end region of the second tubular member overlaps the outer peripheral surface of the end region of the first tubular member. ,
The outer peripheral surface of the end region of the first tubular member and the inner peripheral surface of the end region of the second tubular member are welded by a laser welded portion formed so as to orbit in a predetermined width. A structure characterized by being present. The structure according to claim 1, wherein the second tubular member is a flexible tube that can be bent. The structure according to claim 1 or 2, wherein the second tubular member has heat shrinkage. The structure according to claim 3, wherein the second resin material contains at least a soft vinyl chloride resin. The method for manufacturing a structure according to any one of claims 1 to 4.
The first tubular member is inserted into the second tubular member so that the inner peripheral surface of the end region of the second tubular member overlaps the outer peripheral surface of the end region of the first tubular member. Insertion process and
A laser beam is irradiated from the inside of the first tubular member so as to orbit the inner peripheral surface of the second tubular member, and the outer peripheral surface of the end region of the first tubular member and the second cylinder. A method for manufacturing a structure, which comprises at least a laser light welding step of forming a laser welded portion in which an inner peripheral surface of an end region of a shaped member is welded so as to orbit in a predetermined width. In the pre-process of the insertion step, the lubricant is applied to at least one of the outer peripheral surface of the end region of the first tubular member and the inner peripheral surface of the end region of the second tubular member. The method for manufacturing a structure according to claim 5, further comprising a lubricant coating step. A pre-process of the insertion step, the outer peripheral surface or the outer peripheral surface or the outer peripheral surface of the outer peripheral surface of the end region of the first tubular member or the inner peripheral surface of the end region of the second tubular member. The method for manufacturing a structure according to claim 5, further comprising a resin paste coating step of applying a resin paste that fills the irregularities formed on the inner peripheral surface. The structure according to any one of claims 5 to 7, wherein in the laser light welding step, laser light is irradiated so as to orbit the inner peripheral surface of the second tubular member a plurality of times. Production method.