Welding method, resin-bonded body, and square housing

Abstract

While the first resin component (2) and the second resin component (3) are under pressure, they are welded by laser irradiation. The first resin component (2) is a light-absorbing resin component that absorbs laser light, and the second resin component (3) is a light-transmitting resin component that transmits laser light. The second resin component (3) has a lower inclined surface (31) that is inclined relative to the direction of pressure, and the first resin component (2) has an opposing surface (21) that is opposite to the lower inclined surface (31) and comes into contact with the lower inclined surface (31) due to pressure. In the welding process, the first resin component (2) and the second resin component (3) are welded by irradiating the contact portion (53) between the lower inclined surface (31) and the opposing surface (21) from a direction intersecting the direction of pressure, in a manner that transmits through the second resin component (3). During the welding process, the first resin component (2) that was irradiated by the laser was heated and softened, thereby increasing the contact area between the lower inclined surface (31) and the opposing surface (21).

Description

Technical Field

[0001] This invention relates to a welding method for welding multiple resin components, a resin joint, and a square housing. Background Technology

[0002] Previously, resin joints, which were formed by joining multiple resin components together using laser welding, were used for various purposes.

[0003] The motor described in Patent Document 1 includes a resin housing that houses the rotor and stator, and a resin cover that covers the upper part of the housing. The cover is joined to the housing by laser welding. The cover integrally has a disc-shaped top plate portion and a cylindrical peripheral wall portion, the peripheral wall portion surrounding the outer periphery of the upper cylindrical portion of the housing. The welded portion based on laser welding is continuously formed into an annular shape between the outer peripheral surface of the upper cylindrical portion and the inner peripheral surface of the peripheral wall portion.

[0004] In the vehicle fluid filtration device of Patent Document 2, an upper housing component made of laser-transparent resin and a lower housing component made of laser-non-transparent resin are joined by laser welding to form a resin housing that houses the filter element. Laser welding is performed by irradiating a laser from above the upper flange towards the lower flange with the upper flange of the upper housing component abutting against the lower flange of the lower housing component.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-58001

[0006] Patent Document 2: Japanese Patent Application Publication No. 2006-231875

[0007] In the motor described in Patent Document 1, there is a concern that laser welding cannot be properly performed on the gaps caused by the difference between the outer diameter of the upper cylinder of the housing and the inner diameter of the peripheral wall of the cover. In the device described in Patent Document 2, the resin housing is enlarged due to the provision of upper and lower flange portions, raising concerns about reduced vehicle compatibility. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a welding method, a resin joint, and a square housing that can reliably perform laser welding while suppressing large-scale production.

[0009] To achieve the aforementioned objective, the present invention provides a welding method in which a light-transmitting resin component and a light-absorbing resin component are welded together by laser irradiation while the two components are in contact and under pressure. In this method, one component of the light-transmitting resin component and the light-absorbing resin component has an inclined surface that is tilted relative to the direction of pressure, and the other component has a opposing surface facing the inclined surface. While the light-transmitting resin component and the light-absorbing resin component are under pressure and the inclined surface is in contact with the opposing surface, the laser is irradiated from a direction intersecting the direction of pressure toward the inclined surface and the opposing surface, allowing the laser to penetrate the light-transmitting resin component. During the welding process, the portion of the light-absorbing resin component irradiated by the laser is heated and softened, thereby increasing the contact area between the inclined surface and the opposing surface. The light-transmitting resin component and the light-absorbing resin component are welded while the contact area is increased.

[0010] In addition, in order to achieve the above-mentioned objective, the present invention provides a resin bond comprising a light-transmitting resin component and a light-absorbing resin component, wherein a portion of each of the light-transmitting resin component and the light-absorbing resin component is melted and bonded together by laser irradiation, wherein the shape of the joint portion of the light-transmitting resin component and the light-absorbing resin component in a cross-section along the stacking direction of the light-transmitting resin component and the light-absorbing resin component is curved and inclined relative to the stacking direction.

[0011] In addition, to achieve the above-mentioned objective, the present invention provides a square shell comprising a light-transmitting resin component and a light-absorbing resin component, wherein a portion of each of the light-transmitting resin component and the light-absorbing resin component is melted and joined together by laser irradiation. The shell has a square-shaped base plate portion and a plurality of side plate portions extending from the base plate portion in a direction perpendicular to the base plate portion. The shape of the joint portion of the light-transmitting resin component and the light-absorbing resin component in a cross-section along the direction perpendicular to the base plate portion is curved and inclined relative to the direction perpendicular to the base plate portion.

[0012] According to the welding method, resin joint, and square housing of the present invention, laser welding can be reliably performed while suppressing enlargement. Attached Figure Description

[0013] Figure 1 This is an external view of a battery module having a square casing according to the first embodiment.

[0014] Figure 2 It is an exploded 3D view of the square shell.

[0015] Figure 3 This is a cross-sectional view of the battery module.

[0016] Figure 4 yes Figure 3 An enlarged view of part A.

[0017] Figure 5 yes Figure 3 An enlarged view of part B.

[0018] Figure 6 It is a cross-sectional view showing a portion of the first resin component and a portion of the second resin component before the first resin component is welded to the second resin component.

[0019] Figure 7 It is a cross-sectional view showing the state in which the first resin component and the second resin component are pressurized in the vertical direction in a manner that they are in contact with each other.

[0020] Figure 8 It is a cross-sectional view showing a portion of the second resin component and a portion of the third resin component before the second resin component is welded to the third resin component.

[0021] Figure 9 It is a cross-sectional view showing that the second resin component and the third resin component are pressurized in the vertical direction in a manner that they are in contact with each other.

[0022] Figure 10 This is an explanatory diagram showing the welding process in which a second resin component is welded to a first resin component and a third resin component by irradiating with a laser.

[0023] Figure 11A This is a graph showing an example of the intensity curve of a cap-shaped laser.

[0024] Figure 11B This is a graph representing an example of the intensity curve of a Gaussian laser.

[0025] Figure 11C This is an illustrative diagram showing an example of the shape of a laser beam.

[0026] Figure 11D This is an illustrative diagram showing an example of the shape of a laser beam.

[0027] Figure 12 This is an explanatory diagram showing the state in which a portion of the first resin component softens due to laser irradiation.

[0028] Figure 13 This is an explanatory diagram showing the state in which a portion of the third resin component softens due to laser irradiation.

[0029] Figure 14 This is an explanatory diagram of a variation of the first embodiment, Example 1.

[0030] Figure 15 This is an explanatory diagram of a variation of the first embodiment, Example 2.

[0031] Figure 16 This is an explanatory diagram of variation 3 of the first embodiment.

[0032] Figure 17 This is an explanatory diagram showing the welding process during the manufacturing of the square outer shell according to the second embodiment.

[0033] Figure 18 It is an enlarged representation Figure 17 A magnified view of a portion of it. Detailed Implementation

[0034] [First Implementation Method]

[0035] Reference Figures 1 to 13 The first embodiment of the present invention will be described. Furthermore, the embodiments described below are preferred examples for carrying out the present invention. While various technically preferred aspects are also specifically illustrated, the scope of the present invention is not limited to these specific embodiments.

[0036] Figure 1 This is an external view of the battery module 1 having the square casing 10 of the first embodiment. Figure 2 This is an exploded perspective view of the square outer shell 10. Figure 3 This is a cross-sectional view of battery module 1. Figure 4 yes Figure 3 An enlarged view of part A. Figure 5 yes Figure 3 An enlarged view of part B. Battery module 1 is used, for example, as a power source for a vehicle that has an electric motor as its driving force.

[0037] Battery module 1 has a square resin casing 10 and multiple pouch-type batteries 11. Figure 3 (As shown), and a circuit board 12 on which multiple electronic components 121 are mounted. Multiple pouch batteries 11 and the circuit board 12 are housed in a square housing 10. The square housing 10 is one type of resin bonding assembly of the present invention. The pouch batteries 11 are rechargeable and dischargeable secondary batteries, and more specifically, are lithium-ion batteries or lithium-ion capacitors having a laminated film as the outer casing material.

[0038] In this embodiment, four pouch cells 11 are housed in a square casing 10, and the positive and negative electrodes of these pouch cells 11 are connected in series. A circuit board 12 is equipped with multiple electronic components 121, such as ICs, resistors, and capacitors, for monitoring and controlling the charging state, current, and temperature of each pouch cell 11.

[0039] The square casing 10 has a square-shaped base plate portion 100 and a plurality of side plate portions 101 to 104 extending from the base plate portion 100 in a direction perpendicular to the base plate portion 100. In this embodiment, the base plate portion 100 is rectangular. Hereinafter, the direction perpendicular to the base plate portion 100 will be referred to as the vertical direction, and the direction perpendicular to the vertical direction and perpendicular to the thickness direction of each of the side plate portions 101 to 104 will be referred to as the horizontal direction. However, the vertical direction and the horizontal direction do not necessarily correspond to the vertical and horizontal directions when the battery module 1 is in use.

[0040] Of the multiple side plate portions 101-104, the two side plate portions 101 and 103 extending upward and downward from the long side of the base plate portion 100 have a wider lateral width than the other two side plate portions 102 and 104 extending upward and downward from the short side of the base plate portion 100. Four pouch-type batteries 11 are arranged between the two side plate portions 101 and 103 with the wider lateral width. Figure 3 The image shows a cross-section of the bottom plate portion 100 and the two side plate portions 101 and 103 along the vertical direction.

[0041] In this embodiment, the square outer shell 10 has a three-piece structure, consisting of first to third resin components 2 to 4 made of thermoplastic resin. The first to third resin components 2 to 4 are arranged vertically, and a second resin component 3 is disposed between the first resin component 2 and the third resin component 4. A portion of the first resin component 2 and the second resin component 3, and a portion of the second resin component 3 and the third resin component 4 are hermetically welded together by laser welding based on laser irradiation. Figure 3 The cross-section shown is a cross-section along the stacking direction of the first to third resin components 2 to 4.

[0042] The first resin component 2 forms the base plate portion 100 and a plurality of side plate portions 101 to 104 of the square outer shell 10. The second resin components 3 are continuously disposed at the ends of the side plate portions 101 to 104 of the first resin component 2 opposite to the base plate portion 100. The third resin component 4 is a rectangle whose length in the long side direction is shorter than that of the base plate portion 100, and covers the opening on the upper side of the second resin components 3.

[0043] like Figure 2As shown, the second resin component 3 is provided with a connecting hole 300 that connects the internal space of the first resin component 2 with the internal space of the second resin component 3. The third resin component 4 is provided with a through hole 400, which is sealed by a cover 13. The cover 13 prevents foreign objects from entering the interior of the square outer casing 10 through the through hole 400. When the pressure difference between the inside and outside of the square outer casing 10 increases, air flows through the through hole 400, thus mitigating the pressure difference.

[0044] In this embodiment, the second resin component 3 is a light-transmitting resin component made of a light-transmitting resin, which has the light-transmitting property of allowing laser light to pass through. The first resin component 2 and the third resin component 4 are light-absorbing resin components made of a light-absorbing resin, which has the light-absorbing property of absorbing laser light. That is, in this embodiment, a square outer shell 10 is formed by one light-transmitting resin component (second resin component 3) and two light-absorbing resin components (first resin component 2 and third resin component 4). One light-transmitting resin component (second resin component 3) is sandwiched between two light-absorbing resin components (first resin component 2 and third resin component 4).

[0045] Preferably, the resin material of the second resin component 3 has high compatibility with the resin materials of the first resin component 2 and the third resin component 4, and more preferably, it is the same resin. Furthermore, the resin materials of the first to third resin components 2-4 preferably have high strength that can withstand vibrations and impacts during vehicle operation and low moisture absorption. In this embodiment, the second resin component 3 is made of PBT (polybutylene terephthalate), and the first resin component 2 and the third resin component 4 are made of PBT containing laser-absorbing materials such as carbon black. However, the resin materials of the first to third resin components 2-4 are not limited to PBT; for example, PPS (polyphenylene sulfide) or PP (polypropylene) can also be used.

[0046] Figure 4 The junction 51 between the first resin component 2 and the second resin component 3, and its surrounding portion, are shown. The junction 51 is the portion where a part of the first resin component 2 and a part of the second resin component 3 are fused together and cured. Figure 4 The shape of the joint 51 in the cross-section shown is curved and inclined relative to the stacking direction of the first to third resin components 2 to 4 and the direction perpendicular to the base plate portion 100. The joint 51 is formed in a ring shape across multiple side plate portions 101 to 104.

[0047] Figure 5 The junction 52 between the second resin component 3 and the third resin component 4, and its surrounding portion, are shown. The junction 52 is the portion where a part of the second resin component 3 and a part of the third resin component 4 are fused together and cured. Figure 5The shape of the joint 52 in the cross-section shown is curved and inclined relative to the stacking direction of the first to third resin components 2 to 4 and the direction perpendicular to the base plate portion 100. The joint 52 is formed in a ring shape along the periphery of the third resin component 4.

[0048] The first resin component 2 and the second resin component 3 are sandwiched between the first resin component 2 and the third resin component 4, and the first to third resin components 2 to 4 are pressurized in the vertical direction. The welding of the first resin component 2 and the second resin component 3, and the welding of the second resin component 3 and the third resin component 4 are performed. The second resin component 3 has a lower welding portion 301 corresponding to the end on the side of the first resin component 2, and an upper welding portion 302 corresponding to the end on the side of the third resin component 4.

[0049] Next, refer to Figures 6 to 13 The welding method of the second resin component 3 to the first resin component 2 and the third resin component 4 is described in detail.

[0050] Figure 6 This is a cross-sectional view showing a portion of the first resin component 2 and the second resin component 3 before they are welded together. Figure 7 This is a cross-sectional view showing the state in which the first resin component 2 and the second resin component 3 are pressurized in the vertical direction in a manner that they are in contact with each other. Figure 6 as well as Figure 7 A cross-section perpendicular to the transverse direction is shown for the side panel portion 101 of the square housing 10.

[0051] The lower welding portion 301 of the second resin component 3 is provided with a conical lower inclined surface 31 that is inclined relative to the direction of pressure applied during welding. The lower inclined surface 31 is formed into a ring shape corresponding to each of the multiple side plate portions 101 to 104, and faces towards the inner side of the square outer casing 10. Figure 6 In the example shown, the tilt angle θ1 of the lower inclined surface 31 relative to the direction of pressure (vertical direction) is 30°. However, the tilt angle θ1 is not limited to 30°, for example, it can be above 20° and below 70°.

[0052] Furthermore, a lower sidewall portion 32 is provided on the lower welding portion 301 of the second resin component 3, which is parallel to the lower inclined surface 31 in a direction perpendicular to the direction of pressure. A gap 303 is formed between the lower inclined surface 31 and the lower sidewall portion 32. The lower sidewall portion 32 is formed to protrude downward (towards the base plate portion 100) from the upper end of the lower inclined surface 31. A guide surface 321 for easily guiding the welding portion 20 of the first resin component 2 (described below) into the gap 303 is formed at the front end of the lower sidewall portion 32 at an angle relative to the vertical direction.

[0053] The welding portion 20 of the first resin component 2, which is welded to the lower welding portion 301 of the second resin component 3, has a counter surface 21 opposite to the lower inclined surface 31. The counter surface 21 is a convex shape protruding towards the lower inclined surface 31 of the second resin component 3. More specifically, the counter surface 21 is formed as a convex curved surface. Figure 6 as well as Figure 7 The opposing surface 21 in the cross-section shown has an arc shape.

[0054] When the first resin component 2 and the second resin component 3 are pressurized, the portion of the first resin component 2 with the opposing surface 21, i.e. the welding portion 20, is disposed between the lower inclined surface 31 and the lower side wall portion 32. A portion of the lower inclined surface 31 of the second resin component 3 and a portion of the opposing surface 21 of the first resin component 2 are in linear contact at the contact portion 53.

[0055] An abutment surface 22 is formed in the weld portion 20 of the first resin component 2. This abutment surface 22 is opposite to the lower sidewall portion 32 of the second resin component 3 in the thickness direction and abuts against the lower sidewall portion 32 when the first resin component 2 undergoes elastic deformation due to pressure. The lower sidewall portion 32 restricts the warping of the weld portion 20 in the thickness direction caused by the contact and pressure between the opposing surface 21 and the lower inclined surface 31.

[0056] Figure 8 This is a cross-sectional view showing a portion of each of the second resin component 3 and the third resin component 4 before they are welded together. Figure 9 This is a cross-sectional view showing the state in which the second resin component 3 and the third resin component 4 are pressurized in the vertical direction in a manner that they are in contact with each other.

[0057] The upper welding portion 302 of the second resin component 3 is provided with a conical upper inclined surface 33 that is inclined relative to the direction of pressure applied during welding (vertical direction). The upper inclined surface 33 faces the inner side of the square outer casing 10. Figure 8 In the middle, the tilt angle θ2 of the upper inclined surface 33 relative to the direction of pressure is 30°. However, the tilt angle θ2 is not limited to 30°, for example, it can be above 20° and below 70°.

[0058] Furthermore, an upper sidewall portion 34 is provided on the upper welding portion 302 of the second resin component 3, which is parallel to the upper inclined surface 33 in a direction perpendicular to the direction of pressure. A gap 304 is formed between the upper inclined surface 33 and the upper sidewall portion 34. The upper sidewall portion 34 is formed to protrude upward (towards the third resin component 4) from the lower end of the upper inclined surface 33. A guide surface 341 for easily guiding the welding portion 40 of the third resin component 4 (described below) into the gap 304 is formed at the front end of the upper sidewall portion 34 at an angle relative to the vertical direction.

[0059] The welding portion 40 of the third resin component 4, which is welded to the upper welding portion 302 of the second resin component 3, has a counter surface 41 opposite to the upper inclined surface 33. The counter surface 41 is a convex shape protruding towards the upper inclined surface 33 of the second resin component 3. More specifically, the counter surface 41 is formed as a convex curved surface. Figure 8 as well as Figure 9 The opposing surface 41 in the cross-section shown has an arc shape.

[0060] When the second resin component 3 and the third resin component 4 are pressurized, the portion of the third resin component 4 in which the opposing surface 41 is formed, namely the welding portion 40, is disposed between the upper inclined surface 33 and the upper side wall portion 34. A portion of the upper inclined surface 33 of the second resin component 3 and a portion of the opposing surface 41 of the third resin component 4 are in linear contact at the contact portion 54.

[0061] Furthermore, an abutment surface 42 is formed on the weld portion 40 of the third resin component 4. This abutment surface 42 is opposite to the upper sidewall portion 34 of the second resin component 3 in the thickness direction and abuts against the upper sidewall portion 34 when the third resin component 4 elastically deforms due to pressure. The upper sidewall portion 34 restricts the warping in the thickness direction of the weld portion 40 caused by the contact and pressure between the opposing surface 41 and the upper inclined surface 33.

[0062] Figure 10 This diagram illustrates a welding process in which a second resin component 3 is welded to the first resin component 2 and the third resin component 4 by irradiation with a laser. In this welding process, lasers 610 and 620 are irradiated from the outer portion corresponding to the square outer casing 10 towards the first to third resin components 2-4, simultaneously welding the first resin component 2 to the second resin component 3 and welding the second resin component 3 to the third resin component 4. Furthermore, the first to third resin components 2-4 are pre-molded through an injection molding process performed prior to the welding process. Figure 10 In the diagram, arrow F1 indicates the direction of pressurization for the first to third resin components 2 to 4.

[0063] Pressurize the first resin component 2 and the second resin component 3 in the vertical direction, so that a portion of the lower inclined surface 31 of the second resin component 3 and a portion of the opposing surface 21 of the first resin component 2 are in linear contact at the contact portion 53. Then, the first laser head 61 irradiates the first resin component 2 and the second resin component 3 through the contact portion 53 from the direction intersecting the pressurization direction.

[0064] Pressurize the second resin component 3 and the third resin component 4 in the vertical direction, so that a portion of the upper inclined surface 33 of the second resin component 3 and a portion of the opposing surface 41 of the third resin component 4 are in linear contact at the contact portion 54. Then, the second laser head 62 irradiates the second resin component 3 and the third resin component 4 through the contact portion 54 from the direction intersecting the pressurization direction.

[0065] exist Figure 10 In the example shown, the optical axes 610a and 620a of lasers 610 and 620 are perpendicular to the vertical direction, but this is not a limitation. For example, laser 610 can be irradiated from the first laser head 61 in a manner where the optical axis 610a is perpendicular to the lower inclined surface 31 of the second resin component 3, and laser 620 can be irradiated from the second laser head 62 in a manner where the optical axis 620a is perpendicular to the upper inclined surface 33 of the second resin component 3.

[0066] In the welding process, the first to third resin components 2-4 are clamped vertically by a pressure fixture, and pressure is applied to the first resin component 2 and the second resin component 3, and also to the second resin component 3 and the third resin component 4. Furthermore, during the welding process, while irradiating with lasers 610 and 620, the first and second laser heads 61 and 62 are rotated relative to the first to third resin components 2-4 about the central axis C of the square housing 10. During this relative rotation, the distance between the first and second laser heads 61 and 62 and the first to third resin components 2-4 is adjusted so that the distance between them is an appropriate distance corresponding to the focal length of the lasers 610 and 620. Alternatively, for example, the focal length of the lasers 610 and 620 can be adjusted by adjusting the position of the lenses within the first and second laser heads 61 and 62.

[0067] Generally speaking, intensity curves representing the energy density distribution of laser light are known to be either top-hat type or Gaussian type. Figure 11A This is a graph representing an example of the intensity curve for a cap-shaped structure. Figure 11B These are graphs representing an example of Gaussian intensity curves. The horizontal axis of these graphs represents the distance from the center position O of the laser, and the vertical axis represents the laser intensity. A top-hat type intensity curve is a rectangular distribution where the laser intensity is approximately constant within a specified distance from the center position O, and decreases sharply beyond that distance. On the other hand, a Gaussian type intensity curve is a normal distribution where the laser intensity gradually decreases with distance from the center position O.

[0068] In this embodiment, an energy density distribution such as Figure 11AThe top-hat type lasers 610 and 620 are used for welding. In the direction of pressure application to the first to third resin components 2-4, the widths of the laser 610 irradiating the opposing surface 21 of the first resin component 2 and the widths of the laser 620 irradiating the opposing surface 41 of the third resin component 4 are... Figure 11A The value W0 is shown above. W0 is twice the specified value. The size of W0 is, for example, about 6 mm, but is not limited to this; for example, it can be between 3 mm and 12 mm. The shape of the lasers 610 and 620 in the plane perpendicular to the optical axes 610a and 620a of the lasers 610 and 620 can be circular, elliptical, square, rectangular, or other quadrilateral shapes. Hereinafter, the shape of the lasers 610 and 620 in the plane perpendicular to the optical axes 610a and 620a of the lasers 610 and 620 will be referred to as the laser shape.

[0069] Figure 11C as well as Figure 11D This is an illustrative diagram showing an example of the shape of a laser beam. Figure 11C This is an example of a laser beam with an elliptical shape. Figure 11D This is an example of a laser beam that is rectangular in shape. Figure 11C as well as Figure 11D The solid line in the curve represents the portion of the laser's intensity curve where the intensity changes abruptly. In other words, in the cap-shaped intensity curve... Figure 11C as well as Figure 11D The intensity of the laser inside the solid line is approximately constant, while the intensity of the laser decreases sharply outside the solid line.

[0070] exist Figure 11C as well as Figure 11D In the diagram, arrow A1 indicates the direction of pressurization of the first to third resin components 2 to 4, and arrow A2 indicates the direction perpendicular to the direction of pressurization of the first to third resin components 2 to 4. Figure 11C as well as Figure 11D The laser shape shown is different in width in the direction of pressure of the first to third resin components 2 to 4 and in width in the direction perpendicular to the direction of pressure of the first to third resin components 2 to 4.

[0071] exist Figure 11C as well as Figure 11D In the example shown, the width Wa in the direction of arrow A2 (the direction perpendicular to the direction of pressure) is wider than the width Wb in the direction of arrow A1 (the direction of pressure). However, Wa can also be narrower than Wb. Figure 11C as well as Figure 11DIn the example shown, the width Wb of the laser shape in the short side direction is, for example, 3 mm or more and 12 mm or less. The width Wa in the long side direction is, for example, 3 mm or more and less than the length of each side of the welded workpiece, i.e., the square shell 10. Furthermore, the dimensions of Wa and Wb mentioned above are the dimensions of the portions of the light-absorbing resin components, i.e., the opposing surfaces 21 and 41 of the first resin component 2 and the third resin component 4, irradiated by the lasers 610 and 620.

[0072] The width W0 of the lasers 610 and 620 in the pressurization direction of the first to third resin components 2 to 4 ( Figure 11C as well as Figure 11D The width Wb in the figure is the width in the direction of pressure applied to the welded portions of the lower inclined surface 31 and the upper inclined surface 33 and the opposing surfaces 21 and 41 during the final stage of welding. In other words, the width W0 of the lasers 610 and 620 in the direction of pressure applied to the first to third resin components 2 to 4 is... Figure 4 The width W1 in the same direction of the joint 51 and Figure 5 The width W2 of the joint 52 in the same direction is equal. Here, equal means that the width W0 of the lasers 610 and 620 is more than 0.8 times and less than 1.5 times the widths W1 and W2 of the joints 51 and 52.

[0073] Therefore, if the first and second laser heads 61 and 62 are rotated relative to the first to third resin components 2 to 4 about the central axis C of the square housing 10 at least one revolution, the second resin component 3 can be welded to the first resin component 2 and the third resin component 4 around the entire circumference without changing the vertical position of the first and second laser heads 61 and 62 relative to the first to third resin components 2 to 4.

[0074] During the laser welding process based on laser irradiation 610 and 620, the first resin component 2 and the third resin component 4, which are irradiated by laser 610 and 620, are heated and softened, thereby increasing the contact area between the lower inclined surface 31 and the upper inclined surface 33 and the opposing surfaces 21 and 41. The second resin component 3 is welded to the first resin component 2 and the third resin component 4 under the condition of increased contact area.

[0075] Figure 12 This shows a state in which a portion of the first resin component 2 is softened by irradiation with laser 610, and the contact area between the opposing surface 21 of the first resin component 2 and the lower inclined surface 31 of the second resin component 3 is increased. Figure 13 This shows a state where a portion of the third resin component 3 is softened by irradiation with laser 620, and the contact area between the opposing surface 41 of the third resin component 4 and the upper inclined surface 33 of the second resin component 3 is increased.

[0076] If a portion of the first resin component 2 and the third resin component 4 are heated due to irradiation by lasers 610 and 620, the contact portion of the second resin component 3, which is in contact with the heated portion, also softens due to the temperature rise. In this state, the cross-sectional shape of the contact portion between the lower inclined surface 31 and the upper inclined surface 33 and the opposing surfaces 21 and 41 corresponds to the convex shape of the opposing surfaces 21 and 41. Furthermore, by welding the first to third resin components 2 to 4 in this state, the shapes of the joints 51 and 52 become curved and inclined relative to the stacking direction of the first to third resin components 2 to 4 and the direction perpendicular to the base plate portion 100, as described above.

[0077] Furthermore, during laser welding, the first and second laser heads 61 and 62 rotate relative to the first to third resin components 2 to 4, so the softened portions of the first resin component 2 and the third resin component 4, as well as the portions of the second resin component 3 that are fused and welded to the first resin component 2 and the third resin component 4, gradually extend along the direction of relative rotation.

[0078] (Effects of the first implementation method)

[0079] According to the first embodiment described above, since the lasers 610 and 620 are irradiated while the first to third resin components 2 to 4 are under pressure in the vertical direction, welding can be performed while the lower inclined surface 31 of the second resin component 3 is in reliable contact with the opposing surface 21 of the first resin component 2, and the upper inclined surface 33 of the second resin component 3 is in reliable contact with the opposing surface 41 of the third resin component 4. In other words, even if the first to third resin components 2 to 4 develop irregular shapes such as warping during the injection molding process, the pressure during pressurization causes the first to third resin components 2 to 4 to elastically deform so that the lower inclined surface 31 and the upper inclined surface 33 are in contact with the opposing surfaces 21 and 41, and the lasers 610 and 620 can be irradiated toward the contact portions 53 and 54 where these surfaces are in contact with each other, thus enabling reliable welding. In addition, since it is not necessary to provide a flange portion for welding, as described in Patent Document 2, the square housing 10 can be miniaturized.

[0080] Furthermore, according to the first embodiment, the energy density distribution of lasers 610 and 620 is a top-cap type, and the width W0 of lasers 610 and 620 corresponds to the width in the direction of pressure applied to the welded portions of the lower inclined surface 31 and the upper inclined surface 33 and the opposing surfaces 21 and 41 in the final stage of welding, thus enabling efficient laser welding. Additionally, since the energy density distribution of lasers 610 and 620 is a top-cap type, burn-off or charring of the first resin component 2 and the third resin component 4 can be suppressed.

[0081] Furthermore, according to the first embodiment, the second resin component 3 is welded to the first resin component 2 and the third resin component 4 while the parts of the first resin component 2 and the third resin component 4 that have been irradiated by lasers 610 and 620 are heated and softened, thereby increasing the contact area between the lower inclined surface 31 and the upper inclined surface 33 and the opposing surfaces 21 and 41. Therefore, the bonding strength between the second resin component 3 and the first resin component 2 and the third resin component 4 can be improved.

[0082] [Variation Example 1]

[0083] Next, refer to Figure 14 A variation of the first embodiment, namely Example 1, will be described. In the first embodiment, the case where the opposing surface 21 of the welding portion 20 of the first resin component 2 is formed into a convex curved surface was described, but... Figure 14 In the modified example 1 shown, the opposing surfaces 21 of the welding portion 20 of the first resin component 2 are composed of a pair of inclined surfaces 21a and 21b, and the corner between the pair of inclined surfaces 21a and 21b contacts the lower inclined surface 31. The inclined surface 21a, located inside the gap 303, has an inclination angle relative to the vertical direction that is greater than the inclination angle θ1 of the lower inclined surface 31 (see reference). Figure 6 The other inclined surface 21b has a smaller inclination angle relative to the vertical direction than the inclination angle θ1 of the lower inclined surface 31. The angle θ3 formed by the pair of inclined surfaces 21a and 21b is an obtuse angle, for example, greater than 120° and less than 170°.

[0084] Furthermore, in the first embodiment, the case where the opposing surface 41 of the welding portion 40 of the third resin component 4 is formed into a convex curved surface was described, but... Figure 14 In the modified example 1 shown, the opposing surfaces 41 of the welded portion 40 of the third resin component 4 are composed of a pair of inclined surfaces 41a and 41b, and the corner between the pair of inclined surfaces 41a and 41b contacts the upper inclined surface 33. The inclined surface 41a, located inside the gap 304, has an inclination angle relative to the vertical direction that is greater than the inclination angle θ2 of the upper inclined surface 33 (see reference). Figure 8 The other inclined surface 41b has a smaller inclination angle relative to the vertical direction than the inclination angle θ2 of the upper inclined surface 33. The angle θ4 formed by the pair of inclined surfaces 41a and 41b is an obtuse angle, for example, greater than 120° and less than 170°.

[0085] When welding the second resin component 3 with the first resin component 2 and the third resin component 4 in Modified Example 1, as in the first embodiment, under the condition of applying pressure to the first to third resin components 2 to 4 in the vertical direction, lasers 610 and 620 are simultaneously irradiated toward the contact portion 53 between the lower inclined surface 31 of the second resin component 3 and the opposing surface 21 of the first resin component 2, and the contact portion 54 between the upper inclined surface 33 of the second resin component 3 and the opposing surface 41 of the third resin component 4, to perform laser welding.

[0086] Through this modified example 1, the same effect as the first embodiment can also be obtained.

[0087] [Variation Example 2]

[0088] Next, refer to Figure 15 A variation 2 of the first embodiment will be described. In the first embodiment, a lower inclined surface 31, which is inclined at a constant angle θ1 with respect to the vertical direction, is formed on the lower side weld portion 301 of the second resin component 3, and the opposing surface 21 of the weld portion 20 of the first resin component 2, which is formed in a convex curved surface, contacts the lower inclined surface 31. In variation 2, an inclined surface 23, which is inclined at a constant angle θ5 with respect to the vertical direction, is formed on the weld portion 20 of the first resin component 2, and an opposing surface 35, which is formed in a convex curved surface, is formed and contacts the inclined surface 23.

[0089] In addition, in the first embodiment, the case where the upper inclined surface 33 of the upper welding portion 302 of the second resin component 3 is inclined at a constant angle θ2 relative to the vertical direction, and the opposing surface 41 of the welding portion 40 of the third resin component 4, which is formed in a convex curved surface, is in contact with the upper inclined surface 33, was described. However, in the modified example 2, the welding portion 40 of the third resin component 4 is formed in an inclined surface 43 inclined at a constant angle θ6 relative to the vertical direction, and the upper welding portion 302 of the second resin component 3 is formed in a convex curved surface and is in contact with the inclined surface 43.

[0090] When welding the second resin component 3 with the first resin component 2 and the third resin component 4 in Modified Example 2, laser welding is performed by simultaneously irradiating the contact portion 55 between the inclined surface 23 of the first resin component 2 and the opposing surface 35 of the second resin component 3, and the contact portion 56 between the inclined surface 43 of the third resin component 4 and the opposing surface 36 of the second resin component 3, while the first to third resin components 2 are under pressure in the vertical direction.

[0091] This modified example 2 also achieves the same effect as the first embodiment.

[0092] [Variation Example 3]

[0093] Next, refer to Figure 16 Modification 3 of the first embodiment will now be described. In Modification 3, a light-shielding portion 24 is provided in the welding portion 20 of the first resin component 2, which blocks leakage light from the laser irradiated during the welding process. Furthermore, a light-shielding portion 44 is provided in the welding portion 40 of the third resin component 4, which also blocks leakage light from the laser irradiated during the welding process. The other configurations are the same as in the first embodiment.

[0094] The light-shielding portion 24 of the first resin component 2 is formed to protrude upward toward the inside of the gap 303 compared to the opposing surface 21 of the welding portion 20. The light-shielding portion 44 of the third resin component 4 is formed to protrude downward toward the inside of the gap 304 compared to the opposing surface 41 of the welding portion 40. The light-shielding portions 24 and 44 block the leakage light of the laser from the joint portions 51 and 52 that are detached from the second resin component 3, and suppress the laser from irradiating components inside the second resin component 3 (such as wiring components such as busbars connected to the positive or negative electrode of the pouch cell 11).

[0095] According to this Modification 3, in addition to the effects of the first embodiment, it is also possible to suppress the heating of components inside the second resin component 3 by laser irradiation. Furthermore, the configuration of Modification 3 (light-shielding parts 24, 44) can be added to the configuration of Modification 1 or Modification 2.

[0096] [Second Implementation]

[0097] Next, refer to Figure 17 as well as Figure 18 The second embodiment of the present invention will now be described. Figure 17 This is an explanatory diagram showing the welding process during the manufacturing of the square outer shell 10A of the second embodiment. Figure 18 It is an enlarged representation Figure 17 A magnified view of a portion of it.

[0098] In the first embodiment, the case where the second resin component 3 is a light-transmitting resin component and the first resin component 2 and the third resin component 4 are light-absorbing resin components was described. However, in the second embodiment, the second resin component 8 is a light-absorbing resin component, and the first resin component 7 and the third resin component 9 are light-transmitting resin components. That is, in this embodiment, the square housing 10A is constructed using one light-absorbing resin component (the second resin component 8) and two light-transmitting resin components (the first resin component 7 and the third resin component 9). The light-absorbing resin component (the second resin component 8) is sandwiched between the two light-transmitting resin components (the first resin component 7 and the third resin component 9).

[0099] The square outer shell 10A is the same as the square outer shell 10 of the first embodiment, having a square-shaped base plate portion 100 and multiple side plate portions 101 to 104. The second resin component 8 has a lower weld portion 801 at its end on the side of the first resin component 7 and an upper weld portion 802 at its end on the side of the third resin component 9. The first resin component 7 has a weld portion 70 that is welded to the lower weld portion 801 of the second resin component 8. The third resin component 9 has a weld portion 90 that is welded to the upper weld portion 802 of the second resin component 8. Similar to the first embodiment, the first to third resin components 7 to 9 are welded by irradiation with lasers 610 and 620 while under pressure in the vertical direction.

[0100] The welding portion 70 of the first resin component 7 is provided with an inclined surface 71 that is inclined relative to the direction of pressure (vertical direction) and a wall portion 72 that is parallel to the inclined surface 71 in a direction perpendicular to the direction of pressure. The lower welding portion 801 of the second resin component 8 is disposed in the gap 701 between the inclined surface 71 and the wall portion 72. The lower welding portion 801 of the second resin component 8 has a counter surface 81 that is opposite to the inclined surface 71, and the inclined surface 71 and the counter surface 81 are in contact by pressure.

[0101] The opposing surface 81 is a convex shape that protrudes toward the inclined surface 71. When pressure is applied to the first resin component 7 and the second resin component 8 in a direction that brings them closer together, a portion of the inclined surface 71 and the opposing surface 81 respectively come into linear contact. The wall portion 72 restricts the warping in the thickness direction of the lower weld portion 801 caused by the contact and pressure between the opposing surface 81 and the inclined surface 71.

[0102] The welding portion 90 of the third resin component 9 is provided with an inclined surface 91 that is inclined relative to the direction of pressure and a wall portion 92 that is parallel to the inclined surface 91 in a direction perpendicular to the direction of pressure. The upper welding portion 802 of the second resin component 8 is disposed in the gap 901 between the inclined surface 91 and the wall portion 92. The upper welding portion 802 of the second resin component 8 has a counter surface 82 that is opposite to the inclined surface 91, and the inclined surface 91 and the counter surface 82 are in contact by pressure.

[0103] The opposing surface 82 has a convex shape that protrudes toward the inclined surface 91. When pressure is applied to the second resin component 8 and the third resin component 9 in a direction that brings them closer together, a portion of the inclined surface 91 and the opposing surface 82 respectively come into linear contact. The wall portion 92 restricts the warping in the thickness direction of the upper weld portion 802 caused by the contact and pressure between the opposing surface 82 and the inclined surface 91.

[0104] In the welding process of welding the first to third resin components 7 to 9, lasers 610 and 620 are irradiated onto the first to third resin components 7 to 9 from a portion corresponding to the outer side of the square outer shell 10A. The first and second laser heads 61 and 62 are rotated relative to the first to third resin components 7 to 9 about the central axis C of the square outer shell 10A, so that welding of the first resin component 7 to the second resin component 8 and welding of the second resin component 8 to the third resin component 9 are performed simultaneously. The intensity curves and widths of the lasers 610 and 620 are the same as in the first embodiment.

[0105] The first laser head 61 irradiates a laser 610 from a direction intersecting the pressurization direction toward the contact portion 57 between the inclined surface 71 of the first resin component 7 and the opposing surface 81 of the second resin component 8. The laser 610 passes through the first resin component 7 and irradiates the opposing surface 81 of the lower welding portion 801 of the second resin component 8. As a result, a portion of the second resin component 8 melts into molten resin, and due to the heat of the molten resin, a portion of the first resin component 7 melts, and portions of the first resin component 7 and the second resin component 8 fuse together.

[0106] The second laser head 62 irradiates a laser 620 from a direction intersecting the pressurization direction toward the contact portion 58 between the inclined surface 91 of the third resin component 9 and the opposing surface 82 of the second resin component 8. The laser 620 passes through the third resin component 9 and irradiates the opposing surface 82 of the upper welding portion 802 of the second resin component 8. As a result, a portion of the second resin component 8 melts into molten resin, and due to the heat of the molten resin, a portion of the third resin component 9 melts, and portions of the third resin component 9 and the second resin component 8 fuse together.

[0107] During laser welding based on laser irradiation 610 and 620, the portion of the second resin component 8 irradiated by laser 610 and 620 is heated and softened, thereby increasing the contact area between the inclined surfaces 71 and 91 and the opposing surfaces 81 and 82. The second resin component 8 is then welded to the first resin component 7 and the third resin component 9 in this increased contact area state. The shape of the joint of the first to third resin components 7 to 9 in the cross-section along the stacking direction of the first to third resin components 7 to 9 is the same as in the first embodiment, becoming a curved and inclined shape relative to the stacking direction.

[0108] The same effects as the first embodiment can be obtained through this second embodiment. Furthermore, the configurations of variations 1 to 3 of the first embodiment can also be applied to the second embodiment.

[0109] (Postscript)

[0110] The present invention has been described above based on the first and second embodiments and modifications, but these embodiments and modifications do not limit the invention to which the technical solution pertains. Furthermore, it should be noted that not all combinations of features described in the embodiments and modifications are necessary combinations for solving the problem of the invention. Additionally, the present invention can be appropriately modified by omitting some components, or by adding or substituting components, without departing from its spirit. Furthermore, it is possible to combine some components of the above-described multiple embodiments with each other, and modifications can be made, for example, as described below.

[0111] In the above embodiments, the structure and welding method of the square housings 10 and 10A were described as an example of a resin bond, but the welding method of the present invention is not limited to the square housings 10 and 10A and can be used as a manufacturing method for various resin products. Furthermore, although the above embodiments described a three-piece structure for the square housings 10 and 10A, this is not a limitation; the present invention can also be applied to the manufacture of a two-piece resin bond formed by welding a light-transmitting resin component to a light-absorbing resin component. Additionally, the present invention can also be applied to the manufacture of resin bonds with a structure formed by welding multiple alternately arranged light-transmitting resin components to multiple light-absorbing resin components.

[0112] Furthermore, in the first embodiment described above, the lower inclined surface 31 and the upper inclined surface 33 are described as being inclined at a constant angle relative to the vertical direction, but this is not a limitation. For example, the lower inclined surface 31 and the upper inclined surface 33 may also be curved surfaces with a curvature smaller than that of the opposing surfaces 21 and 41. Similarly, in the second embodiment, the inclined surfaces 71 and 91 may also be curved surfaces with a curvature smaller than that of the opposing surfaces 81 and 82.

[0113] Explanation of reference numerals in the attached figures

[0114] 10, 10A…Square outer shell (resin joint); 100…Bottom plate; 101-104…Side plates; 2, 7…First resin component; 21…Opposing surface; 23…Inclined surface; 24…Light-shielding part; 3, 8…Second resin component; 31…Lower inclined surface; 32…Lower side wall; 33…Upper inclined surface; 34…Upper side wall; 35…Opposing surface; 36…Opposing surface; 4, 9…Third resin component; 41…Opposing surface; 43…Inclined surface; 44…Light-shielding part; 51, 52…Joint; 53-58…Contact part; 610, 620…Laser; 71…Inclined surface; 72…Wall; 81, 82…Opposing surface; 91…Inclined surface; 92…Wall.

Claims

1. A welding method comprising welding a light-transmitting resin component and a light-absorbing resin component together by laser irradiation while the two components are in contact and under pressure, wherein... One of the aforementioned light-transmitting resin components and the aforementioned light-absorbing resin components has an inclined surface that is tilted relative to the direction of pressure, and the other component has an opposing surface that is opposite to the inclined surface. With the light-transmitting resin component and the light-absorbing resin component under pressure and the inclined surface in contact with the opposing surface, the laser is irradiated from a direction intersecting the pressure direction toward the inclined surface and the opposing surface in a manner that allows light to pass through the light-transmitting resin component, thereby welding the light-transmitting resin component and the light-absorbing resin component. During the welding process, the light-absorbing resin component that was irradiated by the laser is heated and softened, thereby increasing the contact area between the inclined surface and the opposing surface. The light-transmitting resin component and the light-absorbing resin component are welded together while the contact area is increased.

2. The welding method according to claim 1, wherein, The width of the laser irradiating the light-absorbing resin component in the pressure direction is the width corresponding to the width of the welded portion in the pressure direction, which is the welded portion of the inclined surface and the opposing surface in the final stage of the welding process.

3. The welding method according to claim 1, wherein, The width of the laser irradiating the light-absorbing resin component in the pressurized direction is equal to the width of the portion in the pressurized direction where the light-transmitting resin component and the light-absorbing resin component are welded together.

4. The welding method according to claim 1, wherein, The width of the laser irradiating the light-absorbing resin component in the pressurized direction is 0.8 times or more and 1.5 times or less the width of the portion in the pressurized direction where the light-transmitting resin component and the light-absorbing resin component are welded.

5. The welding method according to any one of claims 2 to 4, wherein, The energy density distribution of the laser described above is top-hat shaped.

6. The welding method according to claim 5, wherein, The shape of the laser in the plane perpendicular to the optical axis is a shape whose width in the direction of pressure application is different from the width in the direction perpendicular to the direction of pressure application.

7. The welding method according to claim 1, wherein, The aforementioned opposing surface is a convex shape that protrudes towards the aforementioned inclined surface. When the light-transmitting resin component and the light-absorbing resin component are pressurized, a portion of each of the inclined surface and the opposing surface comes into linear contact.

8. The welding method according to claim 7, wherein, The aforementioned opposing surfaces are formed into convex curved surfaces.

9. The welding method according to claim 1, wherein, One of the aforementioned components is provided with a wall portion, which is arranged parallel to the aforementioned inclined surface in a direction perpendicular to the aforementioned pressurization direction. When the light-transmitting resin component and the light-absorbing resin component are pressurized and brought into contact, the portion of the other component having the opposing surface is disposed between the inclined surface and the wall portion.

10. The welding method according to claim 1, wherein, A light-shielding portion is provided in the light-absorbing resin component to block the leakage light of the laser light that has detached from the joint with the light-transmitting resin component.

11. A welding method for welding one of the aforementioned light-transmitting resin components to two of the aforementioned light-absorbing resin components sandwiching the one of the aforementioned light-transmitting resin components, wherein, The welding method of claim 1 allows for the simultaneous welding of one of the light-absorbing resin components to one of the light-transmitting resin components, and the welding of the other of the two light-absorbing resin components to one of the light-transmitting resin components.

12. A welding method for welding one of the aforementioned light-absorbing resin components to two of the aforementioned light-transmitting resin components sandwiching the one of the aforementioned light-absorbing resin components, wherein, The welding method of claim 1 is used to simultaneously weld one of the two light-transmitting resin components to one of the light-absorbing resin components, and to weld the other of the two light-transmitting resin components to one of the light-absorbing resin components.

13. A resin bond comprising a light-transmitting resin component and a light-absorbing resin component, wherein a portion of each of the light-transmitting resin component and the light-absorbing resin component is melted and bonded together by laser irradiation, wherein... The shape of the joint between the light-transmitting resin component and the light-absorbing resin component in the cross-section along the stacking direction of the light-transmitting resin component and the light-absorbing resin component is curved and inclined relative to the stacking direction.

14. A square housing comprising a light-transmitting resin component and a light-absorbing resin component, wherein a portion of each of the light-transmitting resin component and the light-absorbing resin component is melted and bonded together by laser irradiation, wherein... It has a square-shaped base plate and multiple side plate portions extending from the base plate in a direction perpendicular to the base plate. The shape of the junction between the light-transmitting resin component and the light-absorbing resin component in a cross-section perpendicular to the base plate is curved and inclined relative to the direction perpendicular to the base plate.

Images