JP3674479B2 - Plastic molded product - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin molded product. Specifically, a transparent resin material that is transparent to laser light and a non-transparent resin material that is not transparent to the laser light are integrally formed by laser welding. The present invention relates to a joined resin molded product.
[0002]
[Prior art]
In recent years, from the viewpoints of weight reduction and cost reduction, it has been frequently performed to resin parts of various fields such as automobile parts to form resin molded products. Further, from the viewpoint of increasing the productivity of resin molded products, it is often the case that a resin molded product is divided into a plurality of parts and molded, and these divided molded products are joined together.
[0003]
Here, as a method for joining resin materials, a laser welding method has been conventionally used. For example, in JP-A-60-214931, a transparent resin material that is transmissive to laser light and a non-transmissive resin material that is not transmissive to the laser light are superimposed, A laser welding method is disclosed in which laser light is irradiated from the transmissive resin material side to heat and melt the contact surfaces of the transmissive resin material and the non-permeable resin material so as to integrally bond the two. Yes.
[0004]
In this laser welding method, the laser light transmitted through the transmissive resin material reaches the contact surface of the non-transmissive resin material and is absorbed, and the laser light absorbed on the contact surface is accumulated as energy. As a result, the contact surface of the non-permeable resin material is heated and melted, and the contact surface of the transparent resin material is heated and melted by heat transfer from the contact surface of the non-permeable resin material. In this state, if the contact surfaces of the permeable resin material and the non-permeable resin material are pressure-bonded together, they can be joined together.
[0005]
[Problems to be solved by the invention]
By the way, in the laser welding as described above, in order to surely weld the contact surfaces of the transparent resin material and the non-permeable resin material to obtain sufficient bonding strength, the contact surface of the non-permeable resin material. It is necessary that the energy of the laser beam is sufficiently absorbed by the (absorption surface).
[0006]
However, depending on the type of the transmissive resin material and the laser beam, specifically, depending on the laser beam transmittance of the transmissive resin material, the wavelength of the laser beam used as a heating source, etc., the contact surface of the non-transmissive resin material There is a problem that it is difficult to reach and absorb a sufficient amount of laser light.
[0007]
The present invention has been made in view of the above circumstances, and by devising the shape at the contact end portion of the transparent resin material and the non-transparent resin material, more lasers can be applied to the contact surface of the non-transparent resin material. It is a technical problem to be solved to provide a resin molded product that is advantageous in improving the bonding strength by reaching and absorbing light.
[0008]
[Means for Solving the Problems]
(1) The resin molded product according to claim 1 is composed of a transparent resin material that is transparent to laser light as a heating source, and an impermeable resin material that is not transparent to the laser light. In the resin molded product in which the contact end portions of the transparent resin material and the non-permeable resin material are welded and joined by irradiation of the laser light from the transparent resin material side, A concave portion is provided on the laser light incident surface at the contact end portion.
[0009]
(2) The resin molded product according to claim 2 is the resin molded product according to claim 1, wherein a fitting recess is provided on the laser light absorbing surface at the abutting end of the non-permeable resin material. A fitting convex portion that can be fitted to the fitting concave portion is provided at the abutting end portion of the transparent resin material.
[0010]
(3) The resin molded product according to claim 3 is the resin molded product according to claim 1 or 2, wherein the concave portion has a substantially trapezoidal shape in which an opening gradually expands from a bottom surface toward a side irradiated with the laser beam. It has a cross-sectional shape, and a part of the incident surface of the laser beam is constituted by the bottom surface and the inclined side surface of the recess.
(4) The resin molded product according to claim 4 is the resin molded product according to claim 2 or 3, wherein the fitting recess has a substantially base in which an opening gradually expands from a bottom surface toward the side irradiated with the laser beam. A cross-sectional shape is formed, and a part of the laser light absorption surface is formed by the bottom surface and the inclined side surface of the fitting recess.
(5) The resin molded product according to claim 5 is the resin molded product according to claim 1, 2, 3 or 4, wherein the non-permeable resin material and the permeable resin material are in contact with each other in alignment with each other. Each of the contact end portions is formed of a flange portion, and the corresponding contact end portions are integrally joined by laser welding to form a hollow body .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The resin molded product of the present invention comprises a transparent resin material that is transmissive to laser light as a heating source, and a non-transmissive resin material that is not transmissive to the laser light. The contact ends of the material and the non-permeable resin material are integrally joined by laser welding. This laser welding is performed by irradiating laser light from the transparent resin material side in a state where the contact end portions of the transparent resin material and the non-permeable resin material are in contact with each other. The laser light irradiated from the transparent resin material side passes through the transparent resin material, reaches the contact surface (absorption surface) of the non-transmissive resin material, and is absorbed. As a result of the laser light absorbed on the contact surface of the non-permeable resin material being accumulated as energy, the contact surface of the non-permeable resin material is heated and melted, and the contact surface of the non-permeable resin material The contact surface of the permeable resin material is heated and melted by heat transfer from. In this state, if the contact surfaces of the permeable resin material and the non-permeable resin material are pressure-bonded together, they can be joined together.
[0012]
In the joint part obtained in this manner, the joint surfaces are melted and joined, and between the joint surfaces, both resins constituting both molded members are melted and are intertwined with each other. It has a strong bonding state and a high pressure strength by constituting a strong bonding state.
[0013]
Here, in the resin molded product according to the first aspect, the laser light incident surface at the contact end portion of the transparent resin material is provided with a recess. The shape and size of the recess are not particularly limited. For example, it can be a cross-sectional shape such as a substantially trapezoidal shape, a substantially semicircular shape, or a substantially triangular shape.
[0014]
However, if the laser light transmittance in the transparent resin material during laser welding is 26% or more, the welding strength by laser welding can be remarkably improved. For this reason, at least a part of the laser light incident from the concave portion is 26% or more according to the transmittance of the resin used for the transparent resin material with respect to the laser light, the wavelength of the laser light used as the heating source, or the like. It is preferable to set the shape and size (transmission distance) of the recess so as to ensure the transmittance. The laser beam transmittance is a percentage of the energy of the laser beam that has passed through the transparent resin material with respect to the energy of the incident light.
[0015]
Thus, by providing the concave portion on the incident surface of the laser light at the contact end portion of the transparent resin material, the transmission distance of the laser light in the transparent resin material is shortened by the amount corresponding to the concave shape. For this reason, the energy loss of the laser beam while passing through the transparent resin material is reduced. Therefore, more laser light can reach and be absorbed by the contact surface of the non-transparent resin material, and the contact surfaces of the transparent resin material and the non-transparent resin material are sufficiently heated and melted to perform laser welding. It is possible to improve the bonding strength.
[0016]
The resin molded product according to claim 1, wherein a fitting recess is provided in the laser light absorption surface at the contact end portion of the non-permeable resin material, and the contact end portion of the transparent resin material is provided. It is preferable to provide a fitting projection that can be fitted to the fitting depression. The shape and size of the fitting recess and the fitting projection are not particularly limited, and can be a cross-sectional shape such as a substantially trapezoidal shape, a substantially semicircular shape, or a substantially triangular shape, similar to the recessed portion.
[0017]
However, a laser in which at least a part of the laser light reaching the fitting recess is 26% or more depending on the transmittance of the resin used for the transparent resin material with respect to the laser light and the wavelength of the laser light used as a heating source. It is preferable to set the shape and size (transmission distance) of the fitting recess and the fitting protrusion so as to ensure light transmittance.
[0018]
As described above, when the fitting recess is provided in the non-permeable resin material and the fitting convex portion is provided in the transparent resin material, the fitting recess of the non-permeable resin material and the fitting convex portion of the transparent resin material Since the concavo-convex fitting provides a mechanical bonding force between the permeable resin material and the non-permeable resin material, the bonding strength between the two can be further improved.
[0019]
Further, since the warp and the like at the contact end portion of the permeable resin material and the non-permeable resin material are corrected by the mechanical coupling force due to the uneven fitting, the contact surface of the permeable resin material and the non-permeable resin Generation | occurrence | production of a clearance gap between the contact surfaces of material can be suppressed. For this reason, heat generated on the contact surface of the non-permeable resin material can be reliably transferred to the contact surface of the transparent resin material, and the contact surface of the transparent resin material can be reliably heated and melted. Therefore, it is possible to reliably laser weld the contact surfaces of the transmissive resin material and the non-permeable resin material.
[0021]
Then, by adding a dye as a colorant to the transparent resin material and changing the addition amount in various ways, the laser light transmittance in the transparent resin material is changed variously, and the laser light transmittance in the transparent resin material The relationship between welding strength and welding strength was investigated. The results are shown in FIG.
[0022]
As can be seen from FIG. 5 , when the laser light transmittance in the transparent resin material is 26% or more, the welding strength is 45 MPa or more, and it is understood that sufficient welding strength can be achieved.
[0025]
The type of resin used for the transparent resin material is not particularly limited as long as it has thermoplasticity and can transmit laser light as a heating source at a predetermined transmittance or higher. For example, polyamide (PA) such as nylon 6 (PA6) and nylon 66 (PA66), polyethylene (PE), polypropylene (PP), styrene-acrylonitrile copolymer, polyethylene terephthalate (PET), polystyrene, ABS, acrylic (PMMA) ), Polycarbonate (PC), polybutylene terephthalate (PBT), and the like. In addition, you may use what added reinforcing fibers and coloring materials, such as glass fiber and carbon fiber, as needed.
[0026]
The type of resin used for the non-permeable resin material is not particularly limited as long as it has thermoplasticity and can absorb laser light as a heating source without transmitting it. For example, polyamide (PA) such as nylon 6 (PA6) and nylon 66 (PA66), polyethylene (PE), polypropylene (PP), styrene-acrylonitrile copolymer, polyethylene terephthalate (PET), polystyrene, ABS, acrylic (PMMA) ), Polycarbonate (PC), polybutylene terephthalate (PBT), PPS, and the like, and carbon black, a predetermined colorant such as a dye or pigment, and the like. In addition, you may use what added reinforcement fibers, such as glass fiber and carbon fiber, as needed.
[0027]
Moreover, about the combination of resin used for the said permeable resin material and resin used for the said non-permeable resin material, it is set as the combination of mutually compatible things. Examples of such combinations include combinations of resins of the same kind such as nylons 6 and 66, combinations of nylon 6 and nylon 66, combinations of PET and PC, combinations of PC and PBT, and the like. it can.
[0028]
In addition, as the type of laser light used as a heating source, the transmittance in the transparent resin material is a predetermined value in relation to the absorption spectrum, plate thickness (transmission length), etc. of the transparent resin material that transmits the laser light. What has the wavelength which becomes the above is selected suitably. For example, a YAG: Nd ³⁺ laser (laser light wavelength: 1060 nm) or a semiconductor laser (laser light wavelength: 500 to 1000 nm) can be used.
[0029]
Irradiation conditions such as laser output, irradiation density, and processing speed (moving speed) can be set as appropriate according to the type of resin.
[0030]
【Example】
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.
[0031]
(Example 1)
In this embodiment shown in FIGS. 1 to 3, the resin molded product of the present invention is applied to an intake manifold made of synthetic resin, and the resin molded product according to claim 1 , 3 or 5 is embodied. It is.
[0032]
FIG. 1 is a plan view of the intake manifold. FIG. 2 is an enlarged view of the cut end surface of the intake manifold taken along line AA in FIG.
[0033]
The intake manifold 10 is divided into two parts in the vertical direction, and is a hollow body composed of a first molded member 11 that is an upper divided body and a second molded member 12 that is a lower divided body. The 1st shaping | molding member 11 and the 2nd shaping | molding member 12 have contact | abutting edge part 11a and 12a which consist of a flange part which mutually aligns and contacts, respectively. The contact surfaces 11b and 12b of the contact end portion 11a of the first molding member 11 and the contact end portion 12a of the second molding member 12 are integrally joined by laser welding.
[0034]
The first molded member 11 is made of a transparent resin that is transparent to laser light as a heating source, and in this embodiment, 30 wt% of glass fiber as a reinforcing material is added to nylon 6 as the transparent resin. The reinforced plastic added was used. However, by adding 30 wt% of glass fiber, the transmittance of laser light is reduced by 30% as compared with plastic made of nylon 6 not added with glass fiber. The laser beam used for irradiation is a YAG: Nd ³⁺ laser (wavelength: 1060 nm).
[0035]
Moreover, the 2nd shaping | molding member 12 consists of non-permeable resin which is not transmissive with respect to the laser beam as a heating source, and this non-permeable resin is made of nylon 6 in this embodiment as a reinforcing material. A reinforced plastic obtained by adding 30 wt% of fiber and an appropriate amount of carbon black as an auxiliary agent (coloring material) was used.
[0036]
The first molded member 11 and the second molded member 12 are both made of nylon 6 as a base material resin and are compatible with each other.
[0037]
The first molded member 11 has a substantially semi-cylindrical cross-sectional shape as shown in the enlarged view of the portion indicated by the line AA in FIG. An abutting end portion 11a made of a flange portion that bulges in the centrifugal direction is provided at the opening end portion of the first molding member 11 having a substantially semi-cylindrical shape.
[0038]
Further, as shown in FIG. 3 in which this portion is further enlarged, an annular recess 11c is provided on the upper surface of the contact end portion 11a. The concave portion 11c has a substantially trapezoidal cross-sectional shape in which the opening gradually widens from the bottom surface toward the upper side (the side irradiated with the laser beam). As will be described later, the upper surface of the contact end portion 11a becomes the incident surface of the laser beam. The recess 11c has a laser beam transmittance of at least 26% (specifically, about 30%) of the laser beam incident from the recess 11c. The shape and size (transmission distance) are set.
[0039]
On the other hand, the second molded member 12, like the first molded member 11, has a substantially semi-cylindrical cross section, and swells in the centrifugal direction at the open end of the second molded member 12 having a substantially semi-cylindrical shape. A contact end portion 12a made of a protruding flange portion is provided.
[0040]
Then, the abutting end portion 11a of the first molding member 11 and the abutting surfaces 11b and 12b of the abutting end portion 12a of the second molding member 12 are joined together by laser welding in a state where they abut against each other. .
[0041]
The resin molded product of the present example having the above-described configuration was manufactured as follows. First, the 1st shaping | molding member 11 and the 2nd shaping | molding member 12 were injection-molded previously to the predetermined shape using the predetermined | prescribed injection molding die. Then, the contact surfaces 11b and 12b of the contact end portion 11a of the first molding member 11 and the contact end portion 12a of the second molding member 12 are brought into contact with each other. In this state, a laser torch (not shown) is used to irradiate laser light from the first molding member 11 side. That is, the laser beam is irradiated from the upper surface side of the contact end portion 11a of the first molding member 11 and the laser beam is incident from the upper surface of the corresponding contact end portion 11a, whereby the contact end portion 11a of the first molding member 11 is obtained. The contact surfaces 11b and 12b of the second molded member 12 and the contact end portion 12a of the second molding member 12 were heated and melted all over and joined together by laser welding.
[0042]
In the joint portion thus obtained, the contact surfaces 11b and 12b are completely melted and joined to each other, and both resins constituting the molding members 11 and 12 are melted between the contact surfaces 11b and 12b. As a result, the entangled state is formed, so that a strong joined state is formed and high joint strength and pressure strength are provided.
[0043]
In particular, in the resin molded product of the present embodiment, since the concave portion 11c is provided on the incident surface of the laser beam at the contact end portion 11a of the first molded member 11 made of a transparent resin material, the amount corresponding to the concave shape is provided. The transmission distance of the laser light in the transparent resin material is shortened.
[0044]
That is, the laser beam incident with the bottom surface and the inclined side surface of the concave portion 11c as the incident surface has the other surface of the first molding member 11 (the upper surface of the contact end portion 11a of the portion where the concave portion 11c is not provided) as the incident surface. A transmission distance that passes through the first molding member 11 made of a transmissive resin material before reaching the contact surface 12b (absorption surface) of the second molding member 12 made of a non-transmissive resin material, rather than the incident laser light. It tends to be shorter.
[0045]
For this reason, the energy loss of the laser beam while passing through the first molded member 11 made of a transparent resin material is reduced. Therefore, a lot of laser light can reach and be absorbed by the laser light absorption surface at the contact end portion 12a of the second molded member 12 made of the non-permeable resin material, that is, the contact surface 12b of the contact end portion 12a. In addition, the contact surfaces 11b and 12b of the first molding member 11 and the second molding member 12 can be sufficiently heated and melted to improve the bonding strength by laser welding.
[0046]
Further, the recess 11c has a substantially trapezoidal cross-sectional shape in which the opening gradually expands upward (from the side irradiated with the laser beam) from the bottom surface, so that the laser beam having the bottom surface of the recess 11c as the incident surface. In addition, the transmission distance of many laser beams having the inclined side surface of the concave portion 11c as an incident surface is shortened. Therefore, it is advantageous to sufficiently heat and melt the contact surfaces 11b and 12b of the first molding member 11 and the second molding member 12 over a wider range.
[0047]
Further, the shape and size of the concave portion 11c are set so that at least 26% or more of the laser light incident from the bottom surface of the laser beam incident from the concave portion 11c can secure a laser light transmittance. Therefore, the welding strength can be remarkably improved.
[0048]
(Example 2)
This embodiment shown in FIG. 4 embodies the resin molded product according to claim 1 , 2, 3, 4 or 5. In the intake manifold of the first embodiment, the first and second molded members 11 are used. The shape of the contact end portions 11a and 12a is changed.
[0049]
That is, the contact end portion 11a of the first molding member 11 is provided with an annular recess 11c having a substantially trapezoidal cross-sectional shape on the upper surface (laser light incident surface) as in the first embodiment. An annular fitting convex portion 11d that protrudes downward is provided on the lower surface (contact surface 11b). The fitting convex portion 11d has a substantially trapezoidal cross-sectional shape that gradually shrinks and projects toward the tip side (downward side).
[0050]
On the other hand, on the contact end portion 12a of the second molding member 12, an annular fitting recess 12d that can be fitted to the fitting projection 11d on the upper surface (the contact surface 12b serving as a laser light absorbing surface). Is provided. The fitting recess 12d has a shape that matches the fitting projection 11d, and has a substantially trapezoidal cross-sectional shape in which the opening gradually expands upward (from the side irradiated with the laser beam) from the bottom surface.
[0051]
Here, the fitting convex portion 11d, the fitting concave portion 12d, and the concave portion 11c are incident from the bottom surface and the inclined side surface of the concave portion 11c, and reach the bottom surface and the inclined side surface of the fitting concave portion 12d. The shape and size (transmission distance) are set so that the laser beam transmittance of 26% or more (specifically, about 30%) can be secured.
[0052]
Then, the fitting convex portion 11d of the first molding member 11 and the fitting concave portion 12d of the second molding member 12 are fitted to each other, and the contact surface 11b of the first molding member 11 (the inclination of the fitting convex portion 11d). The contact surface 12b (including the inclined side surface and the bottom surface of the fitting recess 12d) of the second molding member 12 and the contact surface 12b of the second molding member 12 are integrally joined by laser welding.
[0053]
When manufacturing the resin molded product of the present embodiment having the above-described configuration, the fitting projection 11d of the first molding member 11 and the fitting recess 12d of the second molding member 12 are fitted together, and the first molding is performed. In a state where the contact surfaces 11b and 12b of the member 11 and the second molding member 12 are in contact with each other, laser light is irradiated from the first molding member 11 side. That is, the laser beam is irradiated from the upper surface side of the contact end portion 11a of the first molding member 11 and the laser beam is incident from the upper surface of the corresponding contact end portion 11a, whereby the contact end portion 11a of the first molding member 11 is obtained. And the contact surfaces 11b and 12b of the second forming member 12 with the contact end portion 12a are heated and melted all over and are integrally joined by laser welding.
[0054]
Therefore, in addition to the effects of the resin molded product of Example 1, the resin molded product of the present example also exhibits the following effects.
[0055]
That is, in this resin molded product, a mechanical coupling force is imparted between the fitting projection 11d of the first molding member 11 and the fitting recess 12d of the second molding member 12 due to the concave and convex fitting. The joint strength between the two can be further improved.
[0056]
Further, since the warp and the like at the contact end portions 11a and 12a of the first molding member 11 and the second molding member 12 are corrected by the mechanical coupling force due to the uneven fitting, the first molding member 11 and the second molding are corrected. Generation of a gap between the contact surfaces 11b and 12b of the member 12 can be suppressed. For this reason, the heat generated in the contact surface 12b of the second molding member 12 made of the non-permeable resin material is reliably transferred to the contact surface 11b of the first molding member 11 made of the transparent resin material, so that the first molding is performed. The contact surface 11b of the member 11 can be reliably heated and melted. Therefore, the contact surfaces 11b and 12b of the first molding member 11 and the second molding member 12 can be reliably laser-welded.
[0057]
Further, by the concave / convex fitting, the contact surface 11b of the first molding member 11 (including the inclined side surface and the tip surface of the fitting convex portion 11d) and the contact surface 12b of the second molding member 12 (the fitting concave portion). 12d (including the inclined side surface and bottom surface), that is, the bonding area by laser welding is also increased, so that the bonding strength can also be improved.
[0058]
In addition, since the fitting convex portion 11d is provided in the first molding member 11 made of a permeable resin material and the fitting concave portion 12d is provided in the second molding member 12 made of a non-permeable resin material, The fact that part of the laser beam is reflected by the inner surface (bottom surface and inclined side surface) of the fitting recess 12d can be used, which is advantageous for more uniform laser welding.
[0059]
The fitting convex portion 11d, the fitting concave portion 12d, and the concave portion 11c are incident on the bottom surface and the inclined side surface of the concave portion 11c, and the laser beam that reaches the bottom surface and the inclined side surface of the fitting concave portion 12d. Since the shape and size are set so that the laser light transmittance of 26% or more can be secured, the welding strength can be remarkably improved.
[0073]
(Relationship between laser light transmittance and welding strength)
A 3 mm thick transparent resin material made of nylon 6 reinforced with 30 wt% glass fiber added and a non-permeable resin material 3 mm thick made of nylon 6 with a predetermined amount of carbon black added, A YAG: Nd ³⁺ laser (wavelength: 1060 nm) was irradiated from the transparent resin material side and bonded integrally by laser welding. The laser output was 400 W and the processing speed was 4 m / min.
[0074]
Then, by adding a dye as a colorant to the transparent resin material and changing the addition amount in various ways, the laser light transmittance in the transparent resin material is changed variously, and the laser light transmittance in the transparent resin material The relationship between welding strength and welding strength was investigated. The result is shown in FIG.
[0075]
As can be seen from FIG. 6, when the laser light transmittance in the transmissive resin material is 26% or more, the welding strength is 45 MPa or more, and it is understood that sufficient welding strength can be achieved.
[0076]
The laser light transmittance was measured by calculating the incident energy based on the presence or absence of a workpiece, and the welding strength was measured by pulling and breaking the welded portion.
[0077]
【The invention's effect】
As described above in detail, according to the resin molded product of the present invention, since the transmission distance of the laser beam that passes through the transmissive resin material is shortened when laser welding is performed, the amount of contact with the non-permeable resin material is increased. The laser beam can reach and be absorbed, which is advantageous in improving the bonding strength by laser welding.
[0078]
In addition, if the transmission distance of the laser light through the transmissive resin material is shortened, the energy of the laser light can be used more efficiently for laser welding, which can contribute to cost reduction by saving energy consumption.
[Brief description of the drawings]
FIG. 1 is a plan view of a synthetic resin intake manifold to which a resin molded product according to the present invention is applied according to Embodiment 1;
2 is a cross-sectional view of a portion indicated by an arrow AA line in FIG. 1 according to the first embodiment.
FIG. 3 is an enlarged partial cross-sectional view illustrating a joint structure between a first molded member and a second molded member according to the first embodiment.
FIG. 4 is an enlarged partial cross-sectional view illustrating a joint structure between a first molded member and a second molded member according to the second embodiment .
FIG. 5 is a diagram showing the relationship between laser light transmittance and welding strength in a transmissive resin material.
[Explanation of symbols]
11 ... 1st shaping | molding member (permeable resin material)
12 ... Second molded member (non-permeable resin material)
11a, 12a ... contact end portions 11b, 12b ... contact surface 11c ... recess 11 d ... fitting projection
1 2d ... fitting recess

Claims (5)

A transparent resin material that is transmissive to laser light as a heating source and a non-transmissive resin material that is not transmissive to the laser light, and the transmissive resin material and the non-transmissive resin material In the resin molded product in which the contact end portions are welded and bonded by irradiation of the laser light from the transparent resin material side,
A resin molded product, wherein a concave portion is provided on an incident surface of the laser beam at the contact end portion of the transparent resin material.   A fitting recess is provided in the laser light absorption surface at the abutting end of the non-permeable resin material, and a fitting that can be fitted with the fitting recess at the abutting end of the transparent resin material. The resin molded product according to claim 1, wherein a joint convex portion is provided.   The concave portion has a substantially trapezoidal cross-sectional shape in which the opening gradually expands from the bottom surface toward the side irradiated with the laser light, and a part of the laser light incident surface is configured by the bottom surface and the inclined side surface of the concave portion. The resin molded product according to claim 1 or 2, wherein   The fitting recess has a substantially trapezoidal cross-sectional shape in which the opening gradually expands from the bottom surface toward the side irradiated with the laser beam, and one of the laser light absorption surfaces is formed by the bottom surface and the inclined side surface of the fitting recess. The resin molded product according to claim 2, wherein a portion is configured. The non-permeable resin material and the permeable resin material each have the contact end portion formed of a flange portion that is in contact with each other in alignment, and the corresponding contact end portions are integrally joined by laser welding. The resin molded product according to claim 1, 2, 3, or 4, wherein a hollow body is formed by the above .

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