Manufacturing method of the structure

Abstract

To suppress occurrence of an appearance defect in a structure body that is an object to be processed.SOLUTION: There is provided a method for manufacturing a structure body, which comprises an ultrasonic welding process. The structure body comprises first and second members, in which the first member is a member made of solid resin, and the second member is a member made of foamed resin. In the ultrasonic welding process, a horn is pressed against the first member arranged so as to be in contact with the second member to ultrasonically weld the first and second members, in which the horn has a spike portion and a base portion, in which the spike portion is formed to taper in a direction in which the horn is pressed against the first member, and provided on a tip side of the base portion.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Patent Document 1 discloses a method of connecting metal members by deforming the metal members so as to expand their diameters.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a resin member is deformed in shape as in Patent Document 1, it will be damaged. Therefore, when connecting resin members, for example, a method using a hot melt adhesive can be considered. However, in the method using a hot melt adhesive, it is necessary to appropriately handle the adhesive having fluidity. That is, in this method, there is a problem that it is necessary to apply the adhesive to a desired position of the resin member so as not to protrude to non-connected portions, and the burden of the process of connecting the resin members increases.

[0005] The present invention has been made in view of such circumstances, and an object thereof is to suppress the working burden of connecting members made of resin.

Means for Solving the Problems

[0006] The present invention provides a method for manufacturing a structure, comprising an ultrasonic welding step, wherein the structure comprises a first and a second member, the first member being made of a solid resin, and the second member being made of a foamed resin, and in the ultrasonic welding step, a horn is pressed against the first member which is positioned to be in contact with the second member, thereby ultrasonically welding the first and second members, the horn having a spike portion and a base portion, the spike portion being formed to taper in the direction in which the horn is pressed against the first member and provided on the tip side of the base portion.

[0007] In this invention, the first and second members can be joined by ultrasonic welding by pressing the horn against the first member which is positioned to contact the second member, thereby reducing the workload of joining the first and second members.

[0008] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other. Preferably, the first member has a thin-walled portion and a thick-walled portion, the thin-walled portion is connected to the thick-walled portion and is thinner than the thick-walled portion, and in the ultrasonic welding process, the horn is pressed against the thin-walled portion. Preferably, the first member has a recess, the recess has a bottom surface and an inner surface, the bottom surface is formed in the thin-walled portion, the inner surface is formed to stand upright on the bottom surface, and an inclined surface is formed on the inner surface, the inclined surface is inclined from the thick-walled portion side to the bottom surface side, and a method is provided. Preferably, the horn has at least three or more spikes, and the spikes are arranged to be located concentrically. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing the outline configuration of an ultrasonic welding apparatus 100 according to an embodiment. [Figure 2]Figure 2A is a perspective view of the vibration transmission section 2 of the horn 1. Figure 2B is a front view of the vibration transmission section 2 shown in Figure 2A. Figure 2C is a bottom view of the vibration transmission section 2 shown in Figure 2A. [Figure 3] Figure 3 is a perspective view of structure 10 (the structure after ultrasonic welding has been completed). [Figure 4] Figure 4A is an enlarged view of region A shown in Figure 3. Figure 4B is a cross-sectional view along the dashed line BB shown in Figure 4A. [Figure 5] Figure 5 is a perspective view of the first member 11 (the first member before ultrasonic welding). [Figure 6] Figure 6 is a cross-sectional view showing the state after the arrangement step of the manufacturing method of the structure 10 according to the embodiment has been completed. In Figure 6, the arrangement table 8 is omitted from the illustration. [Figure 7] Figure 7 shows the ultrasonic welding process of the manufacturing method of the structure 10 according to the embodiment, in which the horn 1 is brought into contact with the first member 11, and then the horn 1 is pressed into the first member 11, resulting in the second member 12 being compressed in the thickness direction. [Figure 8] Figure 8 shows the state in the ultrasonic welding process where the spike portion 2b is embedded in the first member 11 up to the base portion 2b1. [Figure 9] Figure 9 shows the state in which the horn 1 shown in Figure 8 has been retracted from the first member 11 during the retraction step of the manufacturing method of the structure 10 according to the embodiment. [Figure 10] Figure 10A is a perspective view of the vibration transmission unit 2 according to a modified example. Figure 10B is a side view of the vibration transmission unit 2 shown in Figure 10A. Figure 10C is a front view of the vibration transmission unit 2 shown in Figure 10A. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below. The various features shown in the embodiments below can be combined with each other.

[0011] 1. Description of the configuration of the ultrasonic welding apparatus 100 As shown in Figure 1, the ultrasonic welding apparatus 100 comprises a horn 1 having a vibration transmission section 2 and a connecting section 3, a transducer 4, an oscillator 5, a cable 6, a pressurizing mechanism 7, a mounting base 8, and a holding section 9. The ultrasonic welding apparatus 100 also includes a control device (not shown) for controlling the oscillator 5 and the pressurizing mechanism 7. The ultrasonic welding apparatus 100 can manufacture a structure 10 as shown in Figure 3 by ultrasonic welding the first and second members 11 and 12. The first member 11 is a member made of solid resin, and the second member 12 is a member made of foamed resin.

[0012] 1-1. Horn 1 Horn 1 is a tool for transmitting vibrations transmitted from vibrator 4 to first and second members 11 and 12, and for welding the first and second members 11 and 12 together. Horn 1 is provided so as to protrude from the holding part 9. The upper end of horn 1 is fixed within the holding part 9. Horn 1 is made of, for example, a metal material. Examples of metal materials that can be used include aluminum, iron, and titanium.

[0013] 1-1-1. Vibration transmission section 2 As shown in Figures 1 and 2A to 2C, the vibration transmission unit 2 is a rod-shaped member, with its upper end connected to the connecting unit 3. The vibration transmission unit 2 can be manufactured, for example, by processing a metal member with an NC (numerical control) machine. The vibration of the vibrator 4 is transmitted to the vibration transmission unit 2 via the connecting unit 3. The vibration transmission unit 2 comprises a base 2a and a spike portion 2b. The vibration transmission unit 2 comprises a plurality (four in this embodiment) of spike portions 2b. In this embodiment, an example is described in which the vibration transmission unit 2 comprises four spike portions 2b, but it is not limited to this. For example, by providing three or more spike portions 2b in the vibration transmission unit 2, it is possible to suppress the tilting of the posture of the first member 11 when the spike portions 2b are pressed against the first member 11.

[0014] <Base 2a> As shown in Fig. 2A, the base 2a has a columnar portion 2a1 and an end face portion 2a2. The columnar portion 2a1 is formed in a cylindrical shape, and an end face portion 2a2 is formed on the tip side thereof. Four spike portions 2b are provided on the end face portion 2a2, and in the embodiment, it is composed of a flat surface. As shown in Fig. 2A, an annular tapered surface 2a11 is formed on the edge of the tip of the columnar portion 2a1. The diameter R1 (mm) of the columnar portion 2a1 shown in Fig. 2C is specifically, for example, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and it may be within the range between any two of the numerical values exemplified here.

[0015] <spike portion 2b> As shown in Figs. 2A to 2C, the spike portion 2b is formed to taper in the direction of pressing the horn 1 against the first member 11. The spike portion 2b is provided on the tip side (end face portion 2a2) of the base 2a. As shown in Fig. 2C, the vibration transmission portion 2 has a spike portion 2b arranged in the center and three spike portions 2b arranged so as to surround this spike portion 2b. As shown in Figs. 2B and 2C, the three spike portions 2b are arranged such that the position Ot corresponding to the top portion 2b2 forms a triangle (an equilateral triangle in the embodiment). Note that the positions Ot corresponding to the top portions 2b2 of the three spike portions 2b are arranged concentrically. Also, the position O corresponding to the top portion 2b2 of the central spike portion 2b is arranged to coincide with the position of the centroid of the triangle formed by the positions Ot of the three spike portions 2b. In other words, the lengths between the position O and each position Ot are equal. Note that when the vibration transmission portion 2 has only three spike portions 2b, the spike portion 2b arranged in the center may be omitted.

[0016] As shown in FIGS. 2A and 2B, the spike portion 2b is formed in a conical shape. The spike portion 2b has a root portion 2b1, a top portion 2b2, and a side surface portion 2b3. Specifically, for example, the height width h (mm) of the spike portion 2b shown in FIG. 2B is 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, and it may be within the range between any two of the values exemplified here.

[0017] The root portion 2b1 is connected to the end face portion 2a2 and is formed in an annular shape. Here, specifically, for example, the width R2 (mm) of the root portion 2b1 (spike portion 2b) shown in FIG. 2C is 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, and it may be within the range between any two of the values exemplified here.

[0018] The top portion 2b2 is formed at the tip of the spike portion 2b. Specifically, for example, the angle θ (degrees) of the top portion 2b2 shown in FIG. 2B is 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, and it may be within the range between any two of the values exemplified here. Note that the angle θ (degrees) of the top portion 2b2 corresponds to the angle sandwiched by the side surface portion 2b3 when the spike portion 2b is viewed in a vertical cross-section passing through the top portion 2b2.

[0019] The side surface portion 2b3 is formed from the root portion 2b1 to the top portion 2b2. The side surface portion 2b3 is formed to taper in the direction of pressing the horn 1 against the first member 11, and in the embodiment, it is formed in a conical shape.

[0020] 1-1-2. Connecting portion 3 The connecting portion 3 has the function of amplifying the amplitude of the vibration when transmitting the vibration of the transducer 4 to the horn 1. The connecting portion 3 is a rod-shaped member, with its lower part provided on the vibration transmission portion 2, and its upper part housed together with the transducer 4 within the holding portion 9.

[0021] 1-2. Transducer 4 The oscillator 4 is configured to vibrate in response to power supplied from the oscillator 5. The oscillator 4 can be made of, for example, an electrostrictive piezoelectric ceramic oscillator.

[0022] 1-3. Cable 6 and oscillator 5 The oscillator 5 supplies power at the ultrasonic frequency to the transducer 4 via the cable 6.

[0023] 1-4. Pressurization mechanism 7 and holding part 9 The pressurizing mechanism 7 is configured to allow the holding part 9 to move in a predetermined direction. The pressurizing mechanism 7 can be composed of, for example, a motor or a mechanism that moves the holding part 9 using the power of the motor. The predetermined direction is the direction from the holding part 9 side toward the mounting base 8 side, and in this embodiment, it is the vertical direction. Since the vibrator 4 and the horn 1 are held directly or indirectly by the holding part 9, when the holding part 9 is moved by the pressurizing mechanism 7, the horn 1 moves together with the holding part 9.

[0024] 1-5. Placement stand 8 The placement platform 8 is a platform for placing the second member 12. The pressurizing mechanism 7 is fixed by connecting its lower end to the placement platform 8, but the pressurizing mechanism 7 may be fixed at other locations.

[0025] 2. Description of the structure of structure 10 As shown in Figure 3, the structure 10 manufactured by the manufacturing method according to the embodiment comprises first and second members 11 and 12. The structure 10 is constructed by fixing the first member 11 to the second member 12 by welding the first member 11 to the second member 12 by ultrasonic welding. As shown in Figure 4A, a concave portion 11C is formed in the structure 10. The concave portion 11C is formed when the spike portion 2b of the horn 1 is pressed against the first member 11 during ultrasonic welding.

[0026] 2-1. First member 11 The first member 11 is a solid resin component, and the resin constituting the first member 11 can be, for example, polypropylene. However, the resin constituting the first member 11 is not limited to polypropylene, and can be composed of a resin composition including a thermoplastic resin such as polyolefin. Examples of polyolefins include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and mixtures thereof.

[0027] As shown in Figure 3, the first member 11 has a main body 11a and a plurality (three in this embodiment) fixing portion 11b. Although this embodiment shows an example with a plurality of fixing portion 11b, it is not limited to this and may have only one.

[0028] 2-1-1. Main body 11a The shape and function of the main body 11a are not particularly limited, but in this embodiment, the main body 11a corresponds to a retainer, which is a component of the vehicle's back door trim. The main body 11a is connected to the fixing part 11b and is provided to protrude from the fixing part 11b.

[0029] 2-1-2. Fixed part 11b As shown in Figures 4A to 5, the fixing portion 11b is configured in a plate shape. The fixing portion 11b has a thin-walled portion 11A and a thick-walled portion 11B. In addition, a recess 11b1 is formed in the fixing portion 11b.

[0030] <Thin section 11A> As shown in Figure 4B, the thin-walled portion 11A is connected to the thick-walled portion 11B, and the thickness t2 of the thin-walled portion 11A is thinner than the thickness t1 of the thick-walled portion 11B. The thin-walled portion 11A and the thick-walled portion 11B are arranged on the second member 12. In this embodiment, the entire thin-walled portion 11A and the entire thick-walled portion 11B are in contact with the second member 12, but the embodiment is not limited to this configuration. For example, only the area of ​​the thin-walled portion 11A that is welded by the ultrasonic welding device 100 may be in contact with the second member, and the other areas may not be in contact. Also, a part of the thick-walled portion 11B may be in contact with the second member 12, or the entire thick-walled portion 11B may not be in contact with the second member 12.

[0031] The thickness t2 of the thin-walled portion 11A shown in Figure 4B is preferably smaller than the height and width h of the spike portion 2b shown in Figure 2B. As a result, when the horn 1 is pressed against the thin-walled portion 11A and ultrasonic welding is performed, the thin-walled portion 11A melts due to the heat and the spike portion 2b not only penetrates the thin-walled portion 11A but also penetrates the second member 12. Consequently, the resin constituting the thin-walled portion 11A enters the second member 12, and the first and second members 11 and 12 are firmly welded together by the anchoring effect. The thickness t2 (mm) of the thin-walled section 11A shown in Figure 4B is specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, and may also be within the range of any two of the values ​​exemplified here.

[0032] In the manufacturing method according to this embodiment, a thin-walled portion 11A is formed on the fixing portion 1b, so that appropriate ultrasonic welding can be performed with low power and in a short time. In addition, in the manufacturing method according to this embodiment, since the thin-walled portion 11A is partially formed on the fixing portion 1b, it is also possible to suppress a decrease in the rigidity of the first member 11.

[0033] <Thick part 11B> As shown in Figures 4A and 4B, in this embodiment, the thickened portion 11B is arranged to surround the thinned portion 11A. The thickness t1 of the thickened portion 11B is, for example, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, or 5.0 times the thickness t2 of the thinned portion 11A, and may be within the range of any two of the values ​​exemplified here.

[0034] <Recess 11b1> In this embodiment, the recess 11b1 is formed in a circular shape, but is not limited to this, and may be, for example, an n-sided polygon (where n is an integer of 3 or more). The recess 11b1 has an inner surface 11b2 and a bottom surface 11b3.

[0035] As shown in Figures 4A and 4B, the inner surface 11b2 is formed to stand upright on the bottom surface 11b3. The inner surface 11b2 is also formed in an annular shape. Furthermore, an inclined surface Sr is formed on the inner surface 11b2. The inclined surface Sr slopes from the upper side of the thickened portion 11B towards the bottom surface 11b3. In this embodiment, the inclined surface Sr is formed over the entire inner surface 11b2, but this is not limited to this, and the inclined surface Sr may be formed on only a part of the inner surface 11b2. Specifically, the inclination angle α (degrees) of the inclined surface Sr shown in Figure 4B is, for example, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, and may be within the range of any two of the values ​​exemplified here. For example, if the inner surface 11b2 is connected to the bottom surface 11b3 at a 90-degree angle, the connection between the inner surface 11b2 and the bottom surface 11b3 is prone to damage when the horn 1 abuts against the bottom surface 11b3 during ultrasonic welding. In contrast, in this embodiment, an inclined surface Sr is formed on the inner surface 11b2, which helps to suppress damage to the connection between the inner surface 11b2 and the bottom surface 11b3 during ultrasonic welding.

[0036] In this embodiment, the inclined surface Sr is described as a surface forming a constant angle, but it is not limited to this, and may be formed in the shape of an arc that is convex downwards. In this case, the radius (mm) of this arc may be, for example, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, and may be within the range of any two of the values ​​exemplified here.

[0037] The bottom surface 11b3 of the recess 11b1 is the upper surface of the thin-walled portion 11A. In this embodiment, the bottom surface 11b3 is a circular flat surface. The spike portion 2b of the horn 1 is pressed against the bottom surface 11b3. The diameter r (mm) of the bottom surface 11b3 shown in Figure 5 is preferably R1 (mm) + x (mm) of the columnar portion 2a1. Here, x (mm) is specifically, for example, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range of any two of the values ​​exemplified here.

[0038] 2-2. Second member 12 The second member 12 is a member made of foamed resin, and the resin constituting the second member 12 can be, for example, polypropylene. The foaming agent for the foamed resin is not particularly limited, but for example, physical foaming agents, chemical foaming agents and mixtures thereof can be used. The resin constituting the second member 12 is not limited to polypropylene, and can be made of a resin composition containing a thermoplastic resin such as polyolefin. Examples of polyolefins include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer and mixtures thereof. Specifically, the foaming ratio (times) of the foamed resin constituting the second member 12 can be, for example, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, and may be within the range of any two of the values ​​exemplified here.

[0039] The thickness T1 of the second member 12 shown in Figure 4B is preferably greater than the height and width h of the spike portion 2b shown in Figure 2B. This prevents the spike portion 2b from penetrating the second member 12 when the horn 1 is pressed into the first member 11 during ultrasonic welding. The ratio of the thickness T1 of the second member 12 to the height and width h of the spike portion 2b (T1 / h) is specifically, for example, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, and may be within the range of any two of the values ​​exemplified here. Furthermore, the thickness t2 of the thin-walled portion 11A is, for example, 2 times or more the thickness T1 of the second member 12, and preferably 3 times or more.

[0040] 3. Method for manufacturing the structure This method comprises a placement step and an ultrasonic welding step. Each step will be described below.

[0041] 2-1. Placement process In the placement process, the second member 12 is placed on the placement stand 8. Then, as shown in Figure 6, the first member 11 is placed on the second member 12. In this embodiment, the horn 1 of the ultrasonic welding apparatus 100 is described as being movable in the vertical direction and the placement stand 8 and the second member 12 are arranged parallel to the horizontal plane, but this is not the only configuration. For example, the horn 1 may be movable in the left-right direction and the placement stand 8 and the second member 12 may be arranged parallel to a plane perpendicular to the horizontal plane. In this case, it is preferable to have means for fixing the second member 12 to the placement stand 8 and means for fixing the first member 11 to the second member 12.

[0042] 2-2. Ultrasonic welding process In the ultrasonic welding process, the oscillator 5 is driven to vibrate the horn 1. The oscillator 5 may be started during the placement process. Next, the horn 1 is moved downwards, and as shown in Figure 7, the spike portion 2b of the horn 1 is pressed against the thin-walled portion 11A of the first member 11. Here, by controlling the pressurizing mechanism 7, the spike portion 2b pushes the thin-walled portion 11A downwards, and the second member 12, which is made of foamed resin, is pressurized and compressed. Specifically, as shown in Figure 7, the thickness of the second member 12 changes from the thickness T1 in the placement process to the thickness T2 in the ultrasonic welding process. That is, the compression amount D can be expressed as thickness T1 - thickness T2. Note that when the second member 12 is compressed, the overall thickness of the second member 12 does not need to decrease. For example, the thickness of the portion of the second member 12 placed below the thin-walled portion 11A changes from thickness T1 to thickness T2.

[0043] The compression amount D (mm) is specifically, for example, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, and may also be within the range of any two of the values ​​exemplified here. Furthermore, the ratio of the amount of compression D to the thickness T1 of the second member 12 (D / T1) preferably satisfies the relationship 0.1 ≤ D / T1 ≤ 0.5, and more preferably satisfies the relationship 0.2 ≤ D / T1 ≤ 0.44.

[0044] In the ultrasonic welding process, it is preferable, but not limited to, that the amount of compression D is maintained from the time the second member 12 is compressed to a thickness T2 until the horn 1 moves upward and retracts. The amount of compression D may decrease between the time the second member 12 is compressed to a thickness T2 and the time the horn 1 moves upward and retracts.

[0045] As vibrations are transmitted from the spike portion 2b to the first and second members 11 and 12, frictional heat is generated between the first member 11 and the second member 12. As a result, as shown in Figure 8, the thin-walled portion 11A melts, the spike portion 2b penetrates into the thin-walled portion 11A, and then penetrates and pierces the second member 12.

[0046] Subsequently, as shown in Figure 9, the horn 1 is moved upward to retract it from the first member 11. When the horn 1 is retracted from the first member 11, a mortar-shaped concave portion 11C is formed in the first and second members 11 and 12. In this embodiment, since the first member 11 has three fixing portions 11b, the second member 12 is moved and the above operation is repeated for the two fixing portions 11b as well. Once the ultrasonic welding of the three fixing portions 11b is completed, the structure 10 can be manufactured.

[0047] 3. Operation and Effects of the Embodiments In the manufacturing method according to this embodiment, the first and second members 11 and 12 can be connected by ultrasonic welding by pressing the horn 1 against the first member 11 which is positioned to contact the second member 12. In other words, the first and second members 11 and 12 can be connected by the simple operation of pressing the horn 1 against the first member 11, thereby reducing the burden of the connection work for the first and second members 11 and 12.

[0048] In the manufacturing method according to this embodiment, the spike portion 2b penetrates not only the thin-walled portion 11A but also into the second member 12, forming a concave portion 11C in the structure 10. As a result, the resin constituting the thin-walled portion 11A enters the second member 12, and the first and second members 11 and 12 are firmly welded together by the anchoring effect.

[0049] Since the first component 11 is a solid resin component, it is less likely to melt compared to the second component 12, which is made of foamed resin. Therefore, if the thickness of the area on the first component 11 where the horn 1 is pressed is large, the worker may increase the output of the oscillator 5 too much or press the horn 1 against the first component 11 for too long in an attempt to ensure sufficient welding strength. If this happens, the second component 12, which melts more easily than the first component 11, may melt too much, potentially causing defects such as cosmetic imperfections on the underside of the second component 12 (the side opposite to the side where the first component 11 is placed). If the worker lowers the output of the oscillator 5 to avoid such defects, the welding strength may not be sufficient. In the manufacturing method according to this embodiment, ultrasonic welding is performed by pressing the horn 1 against the thin-walled portion 11A rather than the thick-walled portion 11B. As a result, when the horn 1 is pressed against the thin-walled portion 11A, the thin-walled portion 11A melts smoothly, the spike portion 2b smoothly penetrates the second member 12, and the thin-walled portion 11A and the second member 12 are quickly ultrasonically welded together. Therefore, in the manufacturing method according to this embodiment, the output of the oscillator 5 and the time the horn 1 is pressed against the first member 11 can be reduced, and defects on the lower surface of the second member 12 can be suppressed. Furthermore, in the manufacturing method according to this embodiment, since the thin-walled portion 11A melts smoothly, it is also possible to suppress the loss of welding strength.

[0050] In the manufacturing method according to the embodiment, as described above, the output of the oscillator 5 can be reduced during ultrasonic welding, thereby suppressing the generation of burrs caused by excessive melting of the resin. Furthermore, in the manufacturing method according to the embodiment, as described above, the time for which the horn 1 is pressed against the first member 11 during ultrasonic welding can be reduced, thereby shortening the welding cycle.

[0051] Furthermore, since the first member 11 has a thin-walled portion 11A (recess 11b1), the first member is partially thinned. Therefore, in the manufacturing method according to this embodiment, a decrease in the rigidity of the first member 11 can be suppressed. Also, if the entire fixing portion 11b is a thin-walled portion, not only will the rigidity of the first member 11 decrease, but warping may occur during the molding of the first member 11. In the manufacturing method according to this embodiment, the first member is partially thinned, which can suppress warping of the first member 11 during molding. [Examples]

[0052] 4. Examples and Comparative Examples 4-1. Regarding the amount of compression D We checked whether any defects occurred in the structure 10 depending on the compression amount D, and whether the welding strength of the structure 10 was sufficiently ensured. The compression amount D was tested in four patterns: 0.6 mm, 1.0 mm, 1.3 mm, and 1.5 mm. Other conditions are as follows.

[0053] Ultrasonic output (output of oscillator 5): 25J Diameter R1 (mm) of the columnar part 2a1 of horn 1: 10 mm Horn 1 spike section 2b width R2: 2mm The height and width (h) of the spike portion 2b of horn 1 is 2 mm. Diameter r (mm) of base 11b3: 20mm Thickness t2 of the thin-walled portion 11A of the first member 11: 1 mm Thickness T1 of the second member 12: 3 mm

[0054] No appearance defects were observed when the compression amount D was 0.6 mm, 1.0 mm, or 1.3 mm. On the other hand, when the compression amount D was 1.5 mm, ultrasonic welding was performed on 10 sets of first and second members 11 and 12. While 8 sets were good products, 2 sets showed appearance defects, with the gloss of the second member 12 being lost. Although ultrasonic welding is possible even with a compression amount D of 1.5 mm, increasing the compression amount D can more effectively suppress the occurrence of appearance defects. Tensile tests (test speed 50 mm / min) were performed on the first member 11 welded to the second member 12 when the compression amount D was 1.0 mm and 1.3 mm. The testing machine used was a TENSILON universal testing machine. The test results showed that in both cases, the maximum point load when separating the first member 11 from the second member 12 was 200 N or more, confirming that sufficient welding strength was ensured.

[0055] 4-2. Horn without spike section 2b We investigated whether proper ultrasonic welding could be achieved when ultrasonic welding of the first and second members 11 and 12 was performed using a horn without a spike portion 2b. In the case of a horn without a spike portion 2b, its tip portion is composed of a flat end face portion 2a2. When ultrasonic welding was performed on 10 sets of first and second members 11 and 12 using a horn without a spike portion 2b, the second member 12 was overheated in all sets of first and second members 11 and 12, causing the lower surface of the second member 12 to melt and resulting in a defect in the appearance of the second member 12.

[0056] 5. Variations In this embodiment, the horn 1 was provided with a conical spike portion 2b, but it is not limited to this configuration. As shown in Figures 10A to 10C, the top portion 2b2 may be formed to extend in a straight line. In this modified example, three spike portions 2b are provided. The direction in which the top portion 2b2 extends is perpendicular to the direction parallel to the axial direction of the base portion 2a. The root portion 2b1 extends parallel to the top portion 2b2. The side portion 2b3 is formed in a planar shape from the root portion 2b1 to the top portion 2b2. Even with a modified horn 1, the same effects as in the embodiment can be obtained. [Explanation of Symbols]

[0057] 1: Horn 1b:Fixed part 2: Vibration transmission section 2a: base 2a1: Columnar part 2a11: Tapered surface 2a2: End face part 2b: Spikes 2b1: Root part 2b2 :Top 2b3: Side part 3:Connection part 4: Oscillator 5: Oscillator 6: Cable 7: Pressurization mechanism 8: Placement stand 9: Holding part 10 :Structure 11: First member 11A: Thin wall part 11B:Thick part 11C: Concave part 11a: Main body 11b: Fixed part 11b1: recess 11b2: Inner self 11b3: Bottom 12: Second member 100:Ultrasonic welding equipment D: Compression amount Sr: Inclined surface T1: Thickness T2: Thickness h: height width r: diameter t1: Thickness t2: Thickness α: Inclination angle θ: angle

Claims

1. A method for manufacturing a structure, comprising an ultrasonic welding process, The aforementioned structure comprises a first and a second member, The first component is a component made of solid resin, The second component is a component made of foamed resin. In the ultrasonic welding process, the horn is pressed against the first member, which is positioned to contact the second member, and the first and second members are ultrasonically welded together. The horn has a spike portion and a base portion. The spike portion is formed to taper in the direction in which the horn is pressed against the first member, and is provided on the tip side of the base. The first member has a thin-walled portion and a thick-walled portion. The thin-walled portion is connected to the thick-walled portion and is thinner than the thick-walled portion. In the ultrasonic welding process, the top of the spike portion is pressed against the thin-walled portion.

2. A method for manufacturing a structure, comprising an ultrasonic welding process, The aforementioned structure comprises a first and a second member, The first component is a component made of solid resin, The second component is a component made of foamed resin. In the ultrasonic welding process, the horn is pressed against the first member, which is positioned to contact the second member, and the first and second members are ultrasonically welded together. The horn has a spike portion and a base portion. The spike portion is formed to taper in the direction in which the horn is pressed against the first member, and is provided on the tip side of the base. The first member has a thin-walled portion and a thick-walled portion. The thin-walled portion is connected to the thick-walled portion and is thinner than the thick-walled portion. In the ultrasonic welding process, the horn is pressed against the thin-walled portion. A method in which the thin-walled portion is brought into contact with the second member before the horn is pressed against the thin-walled portion.

3. A method according to claim 1 or claim 2, The first member has a recess, The recess has a bottom surface and an inner surface. The bottom surface is formed in the thin-walled portion, The inner surface is formed to stand upright on the bottom surface, In the ultrasonic welding process, the top of the spike portion is pressed against the bottom surface of the thin-walled portion.

4. The method according to claim 3, An inclined surface is formed on the inner surface. The method wherein the inclined surface is sloped from the thickened portion side to the bottom surface side.

5. A method according to any one of claims 1 to 4, The horn has at least three or more of the spike portions, The method wherein the spike portions are arranged so as to be located on concentric circles.

Images