Resin Structure and Method for Producing Resin Structure

Abstract

To provide a resin structure and a method for manufacturing the resin structure that can improve welding strength while suppressing reduction in overall rigidity.SOLUTION: A resin structure 2 includes a first resin member 21 and a second resin member 22 welded to each other. The first resin member 21 and the second resin member 22 respectively include: main body portions 213 and 222; and low crystalline layers 214 and 223 formed on a surface portion and having lower crystallinity than the main body portions 213 and 222. The first resin member 21 and the second resin member 22 are welded to each other in the low crystallinity layers 214 and 223 of the first resin member 21 and the second resin member 22.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a resin structure and a method for manufacturing the resin structure.

Background Art

[0002] Patent Document 1 discloses a laser welding method in which a permeable resin member made of an amorphous resin and an absorbent resin member made of a crystalline resin are laser welded. In the laser welding method described in Patent Document 1, laser light is irradiated onto the surface of the absorbent resin member through the permeable resin member. As a result, the surface of the absorbent resin member absorbs the laser light and generates heat, and this heat welds the absorbent resin member and the translucent resin member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, since the heat of crystal fusion of a resin member tends to increase as the crystallinity is higher, when attempting to weld a resin member with high crystallinity such as a crystalline resin, it is necessary to generate high heat. Therefore, when welding a resin member with high crystallinity, there is a risk that the resin member deteriorates beyond the thermal decomposition temperature or voids are generated, resulting in a decrease in welding strength. On the other hand, if a resin member with simply low crystallinity is adopted as the resin member to be welded, there is a risk that the rigidity of the resin itself cannot be ensured.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resin structure and a method for manufacturing the resin structure that can improve the welding strength while suppressing a decrease in overall rigidity.

Means for Solving the Problems

[0006] In order to achieve the above object, the present invention provides a resin structure including a first resin member and a second resin member welded to each other, wherein at least one of the first resin member and the second resin member has a main body portion and a low-crystalline layer formed on a surface portion and having lower crystallinity than the main body portion, and the first resin member and the second resin member are welded in the low-crystalline layer of at least one of the first resin member and the second resin member.

[0007] Further, in order to achieve the above object, the present invention provides a method for manufacturing a resin structure obtained by welding a first resin member and a second resin member, the method including: forming, in at least one of the first resin member and the second resin member, a low-crystalline layer having lower crystallinity than a main body portion at a portion to be a welding portion on a surface portion; and welding the first resin member and the second resin member in the low-crystalline layer of at least one of the first resin member and the second resin member. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin structure and a method for manufacturing the resin structure that can improve the welding strength while suppressing a decrease in the overall rigidity. [Brief Description of the Drawings]

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0010] [First Embodiment] The first embodiment of the present invention will be described with reference to FIGS. 1 to 8. Note that the embodiments described below are shown as preferred specific examples for carrying out the present invention, and although there are parts that specifically exemplify various technically preferable technical matters, the technical scope of the present invention is not limited to this specific aspect.

[0011] (Rotational Speed Sensor 1) In this embodiment, an example in which the resin structure 2 is applied to the rotational speed sensor 1 is shown. FIG. 1 is a cross-sectional view of the rotational speed sensor 1 of this embodiment. FIG. 2 is an exploded cross-sectional view of the rotational speed sensor 1 of this embodiment.

[0012] The rotational speed sensor 1 is a sensor for detecting the rotational speed of a rotating body mounted on, for example, an automobile. For example, the rotational speed sensor 1 can detect the rotational speed of the wheels of an automobile and can be an ABS sensor used in an ABS (antilock braking system). Further, the rotational speed sensor 1 may be a rotational speed sensor that detects the rotational speed of a rotating body other than the wheels mounted on an automobile, such as a compressor wheel of a turbocharger. Note that the resin structure 2 is applicable to devices other than the rotational speed sensor 1. As an example, it is possible to use the resin structure 2 as a housing and a cover for housing various electronic components. Further, the resin structure 2 does not have to constitute a housing and a cover.

[0013] The rotational speed sensor 1 includes a first resin member 21 and a second resin member 22 welded to each other, a sensor IC 3 as an electronic component housed in the first resin member 21 and the second resin member 22, and a cable 4 connected to the sensor IC 3.

[0014] The first resin member 21 is a housing that houses the sensor IC 3, and the second resin member 22 is a cover that closes the opening of the first resin member 21. Each of the first resin member 21 and the second resin member 22 is made of a thermoplastic resin having electrical insulation properties. For example, each of the first resin member 21 and the second resin member 22 can use an engineering plastic such as polyamide (PA) or polybutylene terephthalate (PBT), or a super engineering plastic such as polyphenylene sulfide (PPS). Further, the engineering plastic and the super engineering plastic may contain glass fiber or the like as a reinforcing material. In the present embodiment, the first resin member 21 and the second resin member 22 are made of the same type of resin material. Note that as the resin materials constituting the first resin member 21 and the second resin member 22, a combination of different resin materials that can be welded to each other can also be adopted.

[0015] The first resin member 21 has a housing portion 211 that opens on one side and houses the sensor IC 3, and a mounting portion 212 that protrudes from the housing portion 211 to the outer peripheral side. The housing portion 211 has a cup shape that opens toward the second resin member 22 side. The mounting portion 212 has a bolt insertion hole 212a formed therein and is fixed to a vehicle body or the like using a bolt.

[0016] The second resin member 22 is provided on the outer peripheral portion of the cable 4. The second resin member 22 is integrally formed with the cable 4 by insert molding in which the cable 4 is inserted into a mold for molding the second resin member 22. The second resin member 22 has a substantially cylindrical shape and has a large-diameter portion 221 at the end on the first resin member 21 side, with the entire circumference protruding toward the outer peripheral side. The large-diameter portion 221 abuts against the surface on the second resin member 22 side of the first resin member 21 and closes the housing portion 211. And the large-diameter portion 221 is welded over the entire circumference around the opening of the housing portion 211 in the first resin member 21.

[0017] Each of the first resin member 21 and the second resin member 22 includes a main body portion 213, 222 and a low-crystallinity layer 214, 223 having lower crystallinity than the main body portion 213, 222. The low-crystallinity layers 214, 223 are formed on the surface portions of the first resin member 21 and the second resin member 22, respectively. The "surface portion" referred to here is a portion of the first resin member 21 or the second resin member 22 that constitutes the surface of the first resin member 21 or the second resin member 22 and has a predetermined thickness, and is a portion that contacts the mold during the molding of the first resin member 21 or the second resin member 22.

[0018] In this embodiment, the main body parts 213 and 222 are crystalline resins. The low-crystallinity layers 214 and 223 are made of a low-crystallinity resin that does not reach an amorphous state without a crystal structure but has lower crystallinity than the main body parts 213 and 222. The crystallinity of each of the main body parts 213 and 222 and the low-crystallinity layers 214 and 223 can be evaluated by, for example, the degree of crystallinity. Also, the crystallinity can be evaluated by, for example, the heat of crystal melting. That is, it can be evaluated that the higher the heat of crystal melting, the higher the crystallinity. The method of forming the main body parts 213 and 222 and the low-crystallinity layers 214 and 223 in each of the first resin member 21 and the second resin member 22 will be described later. In FIGS. 1 and 2, for the sake of convenience, the thickness of the low-crystallinity layers 214 and 223 is exaggerated. Also, for the sake of convenience, in FIGS. 1 and 2, the thickness of the low-crystallinity layers 214 and 223 is shown as uniform throughout, but it does not have to be uniform.

[0019] In this embodiment, the first resin member 21 and the second resin member 22 are fixed to each other by laser welding. The first resin member 21 is an absorber to which a colorant is added in order to have laser absorbability. As the colorant, for example, a carbon-based material such as carbon black can be used. The second resin member 22 is a transmissive material configured to have laser transmissibility. Note that the second resin member 22 does not have to be visually transparent as long as it transmits the laser light used during laser welding. Details will be described later, but the welded portion 10 between the first resin member 21 and the second resin member 22 is formed in the low-crystallinity layers 214 and 223 of the first resin member 21 and the second resin member 22, respectively. A sensor IC 3 is housed in the region surrounded by the first resin member 21 and the second resin member 22.

[0020] The sensor IC 3 includes, for example, a magnetic detection element such as a GMR (Giant Magneto Resistive effect) element, an AMR (Anisotropic Magneto Resistive) element, a TMR (Tunneling Magneto Resistive) element, or a Hall element. The detection signal of the sensor IC 3 is output to a control device or the like arranged inside the vehicle through a cable 4.

[0021] The cable 4 includes a pair of electric wires 41 connected to the sensor IC 3 and a sheath 42 that collectively covers the pair of electric wires 41. The pair of electric wires 41 are connected to a pair of terminals 31 of the sensor IC 3. The sheath 42 is made of an insulating resin or the like. The sheath 42 and the second resin member 22 are integrated by the above-described insert molding of the second resin member 22.

[0022] (Manufacturing method of the rotational speed sensor 1) Next, a manufacturing method of the rotational speed sensor 1 will be described. The manufacturing method of the rotational speed sensor 1 includes a step of manufacturing the first resin member 21, a step of manufacturing the second resin member 22 so as to be integrated with the cable 4, and a step of welding the first resin member 21 and the second resin member 22.

[0023] In the step of manufacturing the first resin member 21, a high-temperature molten resin that constitutes the first resin member 21 is injected into a mold for molding the first resin member 21, and the molten resin is cooled, whereby the first resin member 21 is molded. Here, when manufacturing the first resin member 21, it is devised such that a portion of the first resin member 21 that is welded to the second resin member 22 becomes a low-crystalline layer 214. As such a device, it is conceivable to provide a water hole for flowing low-temperature cooling water at a temperature equal to or lower than a predetermined temperature in the mold in the vicinity of a portion of the first resin member 21 that is welded to the second resin member 22. When the low-crystalline layer 214 is formed on substantially the entire surface of the first resin member 21 as in the present embodiment, the position of the water hole in the mold and the temperature of the cooling water are designed such that the temperature of the entire surface that constitutes the cavity in the mold becomes a low temperature equal to or lower than a predetermined temperature. Thereby, a low-crystalline layer 214 having low crystallinity is formed at a portion of the molten resin that contacts the mold, that is, a surface portion of the first resin member 21. Then, the molten resin located at a position away from the mold is cooled at a relatively low speed and becomes a main body portion 213 having higher crystallinity than the low-crystalline layer 214.

[0024] Incidentally, conventionally, water holes are provided in the mold to cure the molten resin in the mold. However, in order to form the low-crystalline layer 214 on the surface of the first resin member 21, it is necessary to design the position of the water holes in the mold and the temperature of the cooling water so as to cool the surface portion of the molten resin at a cooling rate equal to or higher than a predetermined rate. That is, in this embodiment, in order to intentionally form the low-crystalline layer 214 at a desired position of the first resin member 21, the manufacturing method of the first resin member 21 is devised compared with the conventional method. The cooling rate required to form the low-crystalline layer 214 varies depending on the resin material constituting the first resin member 21. The faster the cooling rate of the molten resin near the mold in the mold, the thicker the low-crystalline layer 214 tends to be formed.

[0025] In the process of manufacturing the second resin member 22, the cable 4 is inserted into the mold of the second resin member 22, and the high-temperature molten resin constituting the second resin member 22 is injected into the mold and cooled, whereby the second resin member 22 is molded. When manufacturing the second resin member 22, it is devised such that the portion of the second resin member 22 that is welded to the first resin member 21 becomes the low-crystalline layer 223. Such a device is the same as the device for forming the low-crystalline layer 214 in the first resin member 21. In the second resin member 22, the low-crystalline layer 223 is formed on the surface portion, and the main body portion 222 is formed other than the surface portion. Note that, among the surface portions of the second resin member 22, the portion that touches the cable 4 and does not touch the mold during molding does not form the low-crystalline layer 223 and becomes the main body portion 222 with high crystallinity.

[0026] Figure 3 is a photograph of the cross-section of the first resin member 21 taken with an optical microscope. The first resin member 21 shown in Figure 3 is a PA resin containing glass fibers. A scale of 500 μm is shown in the lower right of Figure 3. In the main body portion 213 and the low-crystallinity layer 214, when the cross-section is viewed with an optical microscope, the layer structures appear different. That is, by observing the cross-section of the first resin member 21 with an optical microscope or the like, it is possible to determine whether the main body portion 213 and the low-crystallinity layer 214 are formed in the first resin member 21. The same applies to the main body portion 222 and the low-crystallinity layer 223 in the second resin member 22. In Figure 3, the surface of the first resin member 21 is represented by reference numeral 210 for easy understanding of the surface position of the first resin member 21. Also, in Figure 3, above the surface 210, a pedestal on which the first resin member 21 was placed during the cross-section photographing of the first resin member 21 appears.

[0027] Figure 4 is a perspective view showing the process of welding the first resin member 21 and the second resin member 22. In this embodiment, laser light 51 is applied to the surface of the first resin member 21 through the second resin member 22, and the first resin member 21 and the second resin member 22 are laser-welded. At this time, while the laser device 5 that emits the laser light 51 makes one round or a plurality of rounds around the cable 4, the first resin member 21 and the second resin member 22 are laser-welded over the entire circumference around the cable 4. As the laser device 5, a gas laser such as a CO2 laser, a solid laser such as a YAG laser or a Yb fiber laser, etc. can be used. In Figure 4, the location where the laser light 51 is to be applied is represented by a two-dot chain line.

[0028] Figures 5 to 8 are schematic diagrams sequentially showing the state in which the welded portion 10 is formed in the laser welding process. In Figures 5 to 8, for convenience, the boundaries between the main body portion 213 and the low-crystallinity layer 214 of the first resin member 21 and the boundaries between the main body portion 222 and the low-crystallinity layer 223 of the second resin member 22 are each represented by a broken line. Figures 6 and 7 show the state during the irradiation of the laser light 51. The irradiation range of the laser light 51 is shown by a two-dot chain line, and the irradiation direction of the laser light 51 is represented by a white arrow.

[0029] As shown in Fig. 6, when the surface of the first resin member 21 is irradiated with laser light 51 through the second resin member 22, first, the low-crystalline layer 214 of the first resin member 21 absorbs the laser light 51 and generates heat, and a molten portion 100 is formed in the low-crystalline layer 214. Then, as indicated by the thin arrows emerging from the molten portion 100 of the first resin member 21 in Fig. 6, the heat generated by the absorption of the laser light 51 in the first resin member 21 is transmitted from the first resin member 21 to the second resin member 22 side. Due to this heat transfer, as shown in Fig. 7, the low-crystalline layer 223 of the second resin member 22 melts together with the low-crystalline layer 214 of the first resin member 21, and the molten portion 100 spreads. Then, as shown in Fig. 8, by terminating the irradiation of the laser light 51, the heat generation stops, and the molten portion 100 of the low-crystalline layer 214 of the first resin member 21 and the low-crystalline layer 223 of the second resin member 22 hardens, and a welded portion 10 is formed. In this way, the first resin member 21 and the second resin member 22 are welded to each other at their low-crystalline layers 214 and 223.

[0030] The welded portion 10 is formed so as to be within the formation range of the low-crystalline layer 214 of the first resin member 21 and the low-crystalline layer 223 of the second resin member 22, and it is preferably not formed on the main body portion 213 of the first resin member 21 and the main body portion 222 of the second resin member 22. Note that a part of the welded portion 10 may be formed so as to protrude from at least one of the main body portion 213 of the first resin member 21 and the main body portion 222 of the second resin member 22. In this case, it is preferable that more than half (more preferably, 80% or more) of the volume portion of the welded portion 10 is within the formation region of the low-crystalline layer 214 of the first resin member 21 and the low-crystalline layer 223 of the second resin member 22.

[0031] It is preferable that the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 223 of the second resin member 22 is larger than the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 214 of the first resin member 21. As described above, since the low-crystalline layer 223 of the second resin member 22 is melted by indirectly receiving the heat of the laser beam 51 when the heat generated on the first resin member 21 side is transmitted, it is more difficult to melt than the low-crystalline layer 214 of the first resin member 21 during laser welding. Therefore, by forming the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 223 of the second resin member 22 to be thick, the low-crystalline layer 223 of the second resin member 22 can be easily melted during laser welding. Note that the present invention is not limited to this, and for example, the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 214 of the first resin member 21 and the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 223 of the second resin member 22 may be equal. Also, the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 214 of the first resin member 21 may be larger than the thickness of the portion where the welded portion 10 is formed in the low-crystalline layer 223 of the second resin member 22.

[0032] (Operation and Effect of the First Embodiment) In this embodiment, each of the first resin member 21 and the second resin member 22 has a main body portion 213, 222 and a low-crystalline layer 214, 223 formed on the surface portion and having lower crystallinity than the main body portion 213, 222. The first resin member 21 and the second resin member 22 are welded to each other at their respective low-crystalline layers 214, 223. By welding the first resin member 21 and the second resin member 22 in the low-crystalline layer 214, 223 that melts at a relatively low temperature in this way, the heat required during welding can be reduced. Therefore, during welding, it is possible to suppress the first resin member 21 and the second resin member 22 from exceeding the thermal decomposition temperature and the first resin member 21 and the second resin member 22 from deteriorating or voids from occurring in the welded portion 10. Thereby, the welding strength between the first resin member 21 and the second resin member 22 can be improved. Further, since the heat required during welding is reduced, the energy required during welding (for example, the irradiation energy of the laser light when laser welding is performed) can be reduced. Furthermore, by forming the main body portions 213, 222 having higher crystallinity than the low-crystalline layers 214, 223 in the first resin member 21 and the second resin member 22, it is possible to suppress a decrease in the rigidity of the entire resin structure 2 having the first resin member 21 and the second resin member 22. The above-described effects can be obtained if a main body portion and a low-crystalline layer are formed in at least one of the first resin member and the second resin member, and the first resin member and the second resin member are welded in the low-crystalline layer. And the above-described effects are more significantly obtained when, as in this embodiment, the main body portions 213, 222 and the low-crystalline layers 214, 223 are formed in each of the first resin member 21 and the second resin member 22, and the first resin member 21 and the second resin member 22 are welded to each other at their respective low-crystalline layers 214, 223.

[0033] Further, the first resin member 21 is made of an absorber that absorbs the laser light 51, the second resin member 22 is made of a transmissive material that transmits the laser light 51, and the first resin member 21 and the second resin member 22 are laser-welded to each other by the laser light 51. Therefore, it is possible to suppress the heat generated during welding from spreading over a wide area.

[0034] Further, the first resin member 21 made of an absorbent material and the second resin member 22 made of a permeable material are made of the same type of resin material. That is, the melting points of the first resin member 21 and the second resin member 22 are equivalent. Here, as described above, during laser welding, the first resin member 21 generates heat upon receiving laser light irradiation, causing the first resin member 21 to melt, and this heat is transmitted to the second resin member 22, causing the second resin member 22 to melt. Due to such a mechanism, in order to melt both the first resin member 21 and the second resin member 22 made of the same resin material, it is necessary to make the heat generated in the first resin member 21 somewhat higher than the melting points of the first resin member 21 and the second resin member 22 respectively. Therefore, if no special measures are taken, there is a risk that the first resin member 21 will exceed the thermal decomposition temperature, deteriorate, or voids will occur in the melted portion. Thus, by performing laser welding of the first resin member 21 and the second resin member 22 made of the same type of resin material as in this embodiment between these low-crystalline layers 214 and 223, the heat required for welding can be reduced. As a result, it is possible to suppress the deterioration of the first resin member 21 and the occurrence of voids in the welded portion 10, and improve the welding strength between the first resin member 21 and the second resin member 22.

[0035] Also, the resin structure 2 composed of the first resin member 21 and the second resin member 22 is used to accommodate an electronic component (a sensor IC 3 in this embodiment). As described above, according to this embodiment, since the heat generated during welding can be reduced, it is possible to suppress the electronic component housed in the resin structure 2 from being affected by the heat during welding.

[0036] As described above, according to this embodiment, it is possible to provide a resin structure and a method for manufacturing the resin structure that can improve the welding strength while suppressing a decrease in overall rigidity.

[0037] [Second Embodiment] FIG. 9 is an enlarged cross-sectional view of a part of the rotational speed sensor 1 in this embodiment.

[0038] This embodiment is a form in which the formation locations of the low-crystalline layers 214 in the first resin member 21 and 223 in the second resin member 22 are changed with respect to the first embodiment. In this embodiment, the low-crystalline layers 214 and 223 are formed only in the vicinity of the welded portion 10 between the first resin member 21 and the second resin member 22.

[0039] In manufacturing the first resin member 21 and the second resin member 22 of this embodiment, for example, by devising the mold for forming the first resin member 21 and the mold for forming the second resin member 22, the low-crystalline layers 214 and 223 can be formed at desired positions. For example, by forming the water holes of the mold only near the regions where the low-crystalline layers 214 and 223 are formed in the mold, the low-crystalline layers 214 and 223 can be formed at desired positions.

[0040] Other configurations of this embodiment are the same as those of the first embodiment. Among the reference numerals used in the second and subsequent embodiments, those that are the same as the reference numerals used in the previously described embodiments represent the same components and the like as those in the previously described embodiments unless otherwise specified.

[0041] (Actions and Effects of the Second Embodiment) In this embodiment, except for the welded portions 10 of the first resin member 21 and the second resin member 22 respectively, the main body portions 213 and 222 with relatively high crystallinity are used, so the rigidity of the resin structure 2 having the first resin member 21 and the second resin member 22 can be increased. In addition, in this embodiment as well, it has the same actions and effects as the first embodiment.

[0042] (Summary of Embodiments) Next, the technical ideas grasped from the embodiments described above will be described by referring to the reference numerals and the like in the embodiments. However, each reference numeral and the like in the following description are not limited to the members and the like that specifically show the components in the claims in the embodiments.

[0043] [1] A resin structure (2) comprising a first resin member (21) and a second resin member (22) welded to each other, wherein at least one of the first resin member (21) and the second resin member (22) has a main body portion (213, 222) and a low-crystallinity layer (214, 223) formed on the surface portion and having lower crystallinity than the main body portion (213, 222), and the first resin member (21) and the second resin member (22) are welded to each other in the low-crystallinity layer (214, 223) of at least one of the first resin member (21) and the second resin member (22).

[0044] [2] The first resin member (21) is made of an absorber that absorbs laser light (51), the second resin member (22) is made of a transmissive material that transmits the laser light (51), and the first resin member (21) and the second resin member (22) are laser-welded to each other by the laser light, the resin structure (2) according to [1].

[0045] [3] At least the second resin member (22) of the first resin member (21) and the second resin member (22) has the main body portion (222) and the low-crystallinity layer (223), and the low-crystallinity layer (223) of the first resin member (21) and the second resin member (22) is laser-welded to each other by the laser light (51), the resin structure (2) according to [2].

[0046] [4] The first resin member (21) and the second resin member (22) are made of the same resin material as each other, the resin structure (2) according to [3].

[0047] [5] Each of the first resin member (21) and the second resin member (22) has the main body portion (213, 222) and the low-crystallinity layer (214, 223), and the first resin member (21) and the second resin member (22) are welded to each other between the low-crystallinity layers (214, 223) of each other, the resin structure (2) according to any one of [1] to [4].

[0048] [6] The resin structure (2) according to any one of [1] to [5], which is used for housing the electronic component (3).

[0049] [7] A method for manufacturing a resin structure (2) formed by welding a first resin member (21) and a second resin member (22), the method comprising: forming, in at least one of the first resin member (21) and the second resin member (22), a low-crystalline layer (214, 223) having lower crystallinity than the main body part (213, 222) at a part on the surface part that becomes a welding part; and welding the first resin member (21) and the second resin member (22) in the low-crystalline layer (214, 223) of at least one of the first resin member (21) and the second resin member (22).

[0050] [8] The first resin member (21) is made of an absorber that absorbs laser light (51), the second resin member (22) is made of a transmissive material that transmits the laser light (51), and in the step of welding the first resin member (21) and the second resin member (22), the first resin member (21) and the second resin member (22) are laser-welded to each other by the laser light (51). The method for manufacturing a resin structure (2) according to [7].

[0051] [9] At least the second resin member (22) of the first resin member (21) and the second resin member (22) has the main body part (222) and the low-crystalline layer (223), and in the step of welding the first resin member (21) and the second resin member (22), the first resin member (21) and the low-crystalline layer (223) of the second resin member (22) are laser-welded to each other by the laser light (51). The method for manufacturing a resin structure (2) according to [8].

[0052] (Appended Claim) As described above, the embodiments of the present invention have been explained. However, the above-described embodiments do not limit the invention according to the claims. Also, it should be noted that not all combinations of features described in the embodiments are essential means for solving the problems of the invention. Further, the present invention can be appropriately modified and implemented without departing from its gist.

[0053] For example, in each of the above embodiments, an example in which the low-crystalline layer is formed on both the first resin member and the second resin member has been shown. However, the present invention is not limited to this, and it may be formed on only one of the first resin member and the second resin member. At this time, similar to each of the above embodiments, when the first resin member is composed of an absorbent material and the second resin member is composed of a permeable material, and these are laser-welded, it is preferable to form a low-crystalline layer on the second resin member. As described above, since the second resin member melts by receiving the heat generated in the first resin member, the second resin member is less likely to reach a high temperature than the first resin member. By forming a low-crystalline layer on the second resin member, it becomes easier to melt the second resin member during welding.

[0054] Also, in each of the above embodiments, an example in which the first resin member and the second resin member are fixed by laser welding has been shown. However, it is also possible to adopt a welding method other than laser welding. For example, it is also possible to fix the first resin member and the second resin member by vibration welding, ultrasonic welding, high-frequency welding, thermal welding, or the like. Even in these cases, by performing welding on at least one of the low-crystalline layers of the first resin member and the second resin member, it is possible to reduce the temperature of the heat required during welding and the energy (for example, in the case of vibration welding or ultrasonic welding, the energy for generating vibration, etc.).

Explanation of Reference Numerals

[0055] 2... Resin structure 21... First resin member 213... Main body part 214... Low-crystalline layer 22... Second resin member 222... Main body part 223... Low-crystalline layer 3…Sensor IC

Claims

1. A resin structure comprising a first resin member and a second resin member welded to each other, The first resin member made of an absorbent material that absorbs laser light has a first main body portion and a first low-crystallinity layer formed on the surface portion and having lower crystallinity than the first main body portion, The second resin member made of a transmissive material that transmits the laser light has a second main body portion and a second low-crystallinity layer formed on the surface portion and having lower crystallinity than the second main body portion, The first low-crystallinity layer and the second low-crystallinity layer are laser-welded to each other by the laser light, The thickness of the second low-crystallinity layer is larger than the thickness of the first low-crystallinity layer, Resin structure.

2. The first resin member and the second resin member are made of the same type of resin material, The resin structure according to claim 1.

3. The resin material is a PA resin containing glass fibers, The resin structure according to claim 2.

4. Used for accommodating electronic components, The resin structure according to any one of claims 1 to 3.

5. A method for manufacturing a resin structure by welding a first resin member and a second resin member, In the first resin member made of an absorbent material that absorbs laser light, a first step of forming a first low-crystallinity layer having lower crystallinity than the first main body portion at a first portion that is a welding location on the surface portion, In the second resin member made of a transmissive material that transmits the laser light, a second step of forming a second low-crystallinity layer having lower crystallinity than the second main body portion at a second portion that is a welding location on the surface portion, A third step of laser-welding the first low-crystallinity layer and the second low-crystallinity layer to each other by the laser light, and The thickness of the second low-crystallinity layer is formed to be larger than the thickness of the first low-crystallinity layer, Method for manufacturing a resin structure.

6. The first step is performed by preparing a first mold provided with a water hole for flowing cooling water in the vicinity of the first part so that the first part becomes the first low-crystalline layer, injecting the molten resin constituting the first resin member into the first mold, and cooling it. The second step is performed by preparing a second mold provided with a water hole for flowing cooling water in the vicinity of the second part so that the second part becomes the second low-crystalline layer, injecting the molten resin constituting the second resin member into the second mold, and cooling it. The method for manufacturing a resin structure according to claim 5.

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