Joining method

Abstract

To inhibit stress from acting on a second plate-like part in a plate thickness direction when a first plate-like part and the second plate-like part are joined.SOLUTION: In a joint structure 30, a first plate-like part 32 and a second plate-like part 34 are joined. The joint structure 30 has: a first protrusion part 36 protruding from the first plate-like part 32; a second protrusion part 38 protruding from a tip of the first protrusion part 36; and a through hole 40 formed at the second plate-like part 34. The tip of the first protrusion part 36 is placed in contact with the second plate-like part 34. The second protrusion part 38 is inserted into the through hole 40. A tip of the second protrusion part 38 protrudes from the through hole 40. The tip of the second protrusion part 38 is formed with a swage part 44 which is compressed from both sides as seen in a direction intersecting with a protruding direction of the second protrusion part 38.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention provides Joining method Regarding. [Background technology]

[0002] For example, the following technology is known as a joining structure for joining a first plate-shaped portion and a second plate-shaped portion (see, for example, Patent Document 1). That is, in the known technology, the first plate-shaped portion has a protruding portion protruding from the first plate-shaped portion, and the second plate-shaped portion has a through-hole. The protruding portion is inserted into the through-hole, and a crimped portion compressed in the protruding direction of the protruding portion is formed at the tip of the protruding portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-10675 A [Patent Document 2] Japanese Patent Application Publication No. 2019-187140 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned known technology, for example, when the second plate-shaped portion is a circuit board, there is a risk that stress acts on the circuit board in the plate thickness direction when the tip of the protruding portion is compressed in the protruding direction.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a joining structure and joining method that can suppress stress acting on the second plate-shaped portion in the plate thickness direction when joining a first plate-shaped portion and a second plate-shaped portion. [Means for solving the problem]

[0008] The present invention of The joining method is a first plate-shaped portion, a first protruding portion protruding from the first plate-shaped portion, and a second protruding portion protruding from a tip end of the first protruding portion, wherein the first protruding portion and the second protruding portion are formed in a hollow shape such that the inside of the convex portion is hollow; First plate-shaped part of Second plate-shaped part to A joining method for joining, The aforementioned a tip end of the first protrusion abutting against the second plate-shaped portion; The aforementioned The second protruding portion is inserted into the through hole formed in the second plate-shaped portion, and the tip end of the second protruding portion protruding from the through hole of , and compressing from both sides in a direction intersecting the protruding direction of the second protruding portion. By doing so, the tip end of the second protrusion forming a crimped portion.

[0009] According to this joining method, the crimped portion formed at the tip of the second protrusion is formed by compressing it from both sides in a direction intersecting the protrusion direction of the second protrusion, thereby making it possible to suppress stress acting on the second plate-shaped portion when joining the first and second plate-shaped portions. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an example of a motor. [Figure 2] FIG. 2 is a vertical cross-sectional view showing an example of a joining structure. [Figure 3] FIG. 10 is a vertical cross-sectional view showing an example of a joining method. [Figure 4] FIG. 2 is a vertical cross-sectional view showing an example of a driving device. [Figure 5] FIG. 2 is a vertical cross-sectional view showing an example of a first operating state of the driving device. [Figure 6] FIG. 10 is a vertical cross-sectional view showing an example of a second operating state of the driving device. [Figure 7] FIG. 10 is a vertical cross-sectional view showing an example of a third operating state of the driving device. [Figure 8] FIG. 10 is a vertical cross-sectional view showing an example of a fourth operating state of the driving device. [Figure 9] FIG. 10 is a vertical cross-sectional view showing an example of a fifth operating state of the driving device. [Figure 10] FIG. 10 is a vertical cross-sectional view showing an example of a sixth operating state of the driving device. [Figure 11] FIG. 10 is a vertical cross-sectional view showing an example of a seventh operating state of the driving device. [Figure 12]FIG. 10 is a vertical cross-sectional view showing an example of an eighth operating state of the driving device. [Figure 13] FIG. 13 is a vertical cross-sectional view showing an example of a ninth operating state of the driving device. [Figure 14] FIG. 16 is a vertical cross-sectional view showing an example of a tenth operating state of the driving device. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below.

[0012] FIG. 1 shows, as an example, a motor 10 to which a joining structure 30 according to one embodiment of the present invention is applied. The motor 10 includes a motor shaft 12, a rotor 14, a stator 16, a motor holder 18, a center piece 20, a circuit board 22, a circuit case 24, and a heat sink 26. Except for the joining structure 30, the motor 10 has the same configuration as the motor disclosed in Patent Document 2. As an example, the joining structure 30 is used to join the heat sink 26 and the circuit board 22. As an example, the heat sink 26 is made of a metal such as an aluminum alloy, and the circuit board 22 is a printed circuit board made of resin.

[0013] FIG. 2 shows an example of a joining structure 30. The joining structure 30 is a structure that joins a first plate-shaped portion 32 and a second plate-shaped portion 34. The first plate-shaped portion 32 is a part of the heat sink 26, and the second plate-shaped portion 34 is a part of the circuit board 22. Note that the first plate-shaped portion 32 is a part of the heat sink 26, but may be a part of a member other than the heat sink 26. Also, the second plate-shaped portion 34 is a part of the circuit board 22, but may be a part of a member other than the circuit board 22. Also, the joining structure 30 may be applied to devices or members other than the motor 10.

[0014] The joining structure 30 has a first protruding portion 36 protruding from the first plate-shaped portion 32, a second protruding portion 38 protruding from the tip of the first protruding portion 36, and a through hole 40 formed in the second plate-shaped portion 34. The protruding direction of the first protruding portion 36 and the protruding direction of the second protruding portion 38 both coincide with the plate thickness direction of the first plate-shaped portion 32. The first protruding portion 36 and the second protruding portion 38 are formed by stamping, as will be described later, and form a two-stage stamped portion 42.

[0015] The first protruding portion 36 is formed to have a circular cross section. The first protruding portion 36 is formed to have a hollow shape by being formed by stamping. The portion of the second protruding portion 38 excluding its tip end is also formed to have a circular cross section. The first protruding portion 36 is formed to have a hollow shape by being formed by stamping. In other words, the portion of the second protruding portion 38 excluding its tip end is formed to have a hollow shape. The through hole 40 is formed to have a circular cross section. Note that the first protruding portion 36 and the second protruding portion 38 may be formed to have a solid shape by, for example, cutting, forging, casting, injection molding, or the like.

[0016] The tip of the first protruding portion 36 abuts against the second plate-shaped portion 34, and the second protruding portion 38 is inserted into the through-hole 40. The tip of the second protruding portion 38 protrudes from the through-hole 40, and a crimping portion 44 is formed at the tip of the second protruding portion 38.

[0017] As will be described later, the crimping portion 44 is crimped by being compressed from both sides in a direction intersecting the protruding direction of the second protruding portion 38 (for example, a direction perpendicular to the protruding direction). The crimping portion 44 has a collapsed shape that extends in the longitudinal direction by being compressed from both sides in the direction intersecting the protruding direction of the second protruding portion 38. As shown in the lower diagram of Figure 2, when the crimping portion 44 is viewed in cross section, both ends 44A of the crimping portion 44 in the longitudinal direction are engaged with the peripheral portion of the through hole 40.

[0018] The first protruding portion 36 and the crimping portion 44 (i.e., both end portions 44A in the longitudinal direction) sandwich the second plate-shaped portion 34. The second plate-shaped portion 34 is fixed to the first plate-shaped portion 32 by being sandwiched between the first protruding portion 36 and the crimping portion 44. The second plate-shaped portion 34 may be fixed to the first plate-shaped portion 32 either permanently or temporarily. In the case of temporary fixation, the second plate-shaped portion 34 may be fixed to the first plate-shaped portion 32 by being sandwiched between the first plate-shaped portion 32 and another member (not shown).

[0019] Next, a joining method according to one embodiment of the present invention will be described.

[0020] 3 shows a crimping device 50. The crimping device 50 includes a core bar 52 and a pair of crimping tools 54. The crimping device 50 is used in a joining method according to one embodiment of the present invention.

[0021] A joining method according to one embodiment of the present invention is a method for joining a first plate-shaped portion 32 and a second plate-shaped portion 34. This joining method includes a preparation step and a crimping step. The left diagram of Fig. 3 shows the preparation step, and the right diagram of Fig. 3 shows the crimping step.

[0022] In the preparation step, the tip of the first protruding portion 36 protruding from the first plate-shaped portion 32 abuts against the second plate-shaped portion 34. Furthermore, the second protruding portion 38 protruding from the tip of the first protruding portion 36 is inserted into the through hole 40. In this state, the tip of the second protruding portion 38 protrudes from the through hole 40. A core metal 52 is inserted inside the first protruding portion 36. The tip (i.e., the lower end) of the core metal 52 abuts against the bottom of the first protruding portion 36, and the outer peripheral surface of the core metal 52 contacts the inner peripheral surface of the first protruding portion 36.

[0023] In the crimping process, the tip of the second protruding portion 38 protruding from the through hole 40 is compressed by a pair of crimping tools 54 from both sides in a direction intersecting the protruding direction of the second protruding portion 38 (for example, a direction perpendicular to the protruding direction). Then, the tip of the second protruding portion 38 is compressed by the pair of crimping tools 54, thereby forming a crimped portion 44.

[0024] Next, an embossing method for manufacturing the two-stage embossed portion 42 according to one embodiment of the present invention will be described.

[0025] 4 shows an embossing device 60. The embossing device 60 is a device for manufacturing the two-stage embossed portion 42. The embossing device 60 includes a punch 62, a die 64, and a pressing die 66.

[0026] The punch 62 has a main body 68 and a protrusion 70 protruding from the tip of the main body 68. The die 64 has a first recess 72 whose inner diameter is larger than the outer diameter of the main body 68, and a second recess 74 formed at the bottom of the first recess 72. The first recess 72 and the second recess 74 have shapes corresponding to the first protrusion 36 and the second protrusion 38 described above, and are each formed with a circular cross section. The inner diameter of the second recess 74 is smaller than the outer diameter of the main body 68 and larger than the outer diameter of the protrusion 70. The pressing die 66 has a hole 76 formed therein, and the punch 62 is housed in the hole 76. The protrusion dimension (i.e., height H) of the protrusion 70 relative to the tip of the main body 68 is set to be smaller than the thickness dimension (i.e., thickness T) of a plate material (see FIG. 5 ) described below. In FIG. 4, the clearance between the main body 68 and the pressing die 66 is exaggerated, and in reality, the clearance between the main body 68 and the pressing die 66 is extremely small.

[0027] The peripheral edge 68A at the tip of the main body 68 increases in diameter toward the base end (not shown) of the main body 68, i.e., the side away from the die 64, and is formed by a tapered surface that is convexly curved in vertical cross section. The peripheral edge 70A at the tip of the convex portion 70 increases in diameter toward the base end 70B of the convex portion 70, and is formed by a tapered surface that is convexly curved in vertical cross section. The base end 70B of the convex portion 70 increases in diameter toward the main body 68, and is formed by a tapered surface that is concavely curved in vertical cross section. The term "tapered surface" is a concept that also includes an R-shape.

[0028] A peripheral edge 72A of the opening of the first recess 72 increases in diameter toward the bottom of the first recess 72 and is formed by a tapered surface that is convexly curved in vertical cross section. A peripheral edge 74A of the opening of the second recess 74 increases in diameter toward the bottom of the second recess 74 and is formed by a tapered surface that is convexly curved in vertical cross section. The stamping device 60 having the above configuration is used in a stamping method according to one embodiment of the present invention.

[0029] An embossing method according to one embodiment of the present invention is a method for manufacturing a two-stage embossed portion 42. Figures 5 to 14 show how the two-stage embossed portion 42 is manufactured by this embossing method.

[0030] In this embossing method, as shown in Fig. 5, a plate material 80 is set in a die 64. The plate material 80 corresponds to, for example, the heat sink 26 before the two-stage embossment portion 42 is formed. The plate material is pressed by a presser die 66 from the side opposite the die 64. Then, as shown in Figs. 5 to 14, the punch 62 moves toward the die 64, and the plate material 80 is pressed by the main body portion 68 and the protrusion portion 70. The punch 62 moves toward the die 64 until the two-stage embossment portion 42 is formed.

[0031] As will be described in detail later, when the plate material 80 is pressed by the main body portion 68, a first protrusion 36 protruding from a part of the plate material 80 is formed as shown in FIG. 14. The part of the plate material 80 corresponds to the first plate-shaped portion 32. When the plate material 80 is pressed by the convex portion 70, a second protrusion 38 protruding from the tip of the first protrusion 36 is formed. The dots on the plate material 80 shown in FIGS. 5 to 14 indicate the distribution of stress acting on the plate material 80 during the stamping process. The darker the dots, the higher the stress. Furthermore, in FIGS. 5 to 14, the shape of the plate material 80 is exaggerated based on the stress distribution.

[0032] Fig. 7 shows a state immediately before the main body 68 starts to press the sheet material 80. In this punching method, more specifically, as shown in Fig. 7, immediately before the main body 68 starts to press the sheet material 80, the sheet material 80 is bent, and a gap 82 is formed between the punch 62 and the sheet material from the base end 70B of the convex portion 70 to the tip end of the main body 68 (i.e., the underside of the main body 68). In this way, until the main body 68 starts to press the sheet material 80, the sheet material 80 is pressed by the convex portion 70 so that the gap 82 is formed.

[0033] 10 shows a state immediately before the protrusion 70 begins to be inserted into the second recess 74. In this driving method, more specifically, as shown in FIG. 10, before the protrusion 70 begins to be inserted into the second recess 74, the plate material 80 is compressed between the tip of the main body 68 and the bottom of the first recess 72. Then, by compressing the plate material 80 between the tip of the main body 68 and the bottom of the first recess 72, the tensile force F2 acting on the plate material 80 between the outer peripheral surface of the main body 68 and the inner peripheral surface of the first recess 72 is reduced.

[0034] In addition, in this striking method, more specifically, as shown in Figures 10 to 14, the plate material 80 is compressed by the outer surface of the main body portion 68 and the inner surface of the first recessed portion 72, and in a state in which the plate material 80 is compressed by the tip of the main body portion 68 and the bottom of the first recessed portion 72, the plate material 80 is pressed by the convex portion 70, thereby forming the second protrusion portion 38.

[0035] Next, the effects of one embodiment of the present invention will be described.

[0036] As described above in detail, according to the joining structure 30 according to one embodiment of the present invention, as shown in Fig. 3, the crimping portion 44 formed at the tip of the second protruding portion 38 is formed by being compressed from both sides in a direction intersecting the protruding direction of the second protruding portion 38 (for example, a direction perpendicular to the protruding direction). Therefore, when joining the first plate-shaped portion 32 and the second plate-shaped portion 34, it is possible to prevent stress from acting on the second plate-shaped portion 34 in the plate thickness direction. This makes it possible to prevent deformation of the second plate-shaped portion 34 (for example, a part of the circuit board 22).

[0037] Furthermore, as shown in FIG. 2, the first protrusion 36 and the crimping portion 44 sandwich the second plate-shaped portion 34, and therefore the first protrusion 36 and the crimping portion 44 can fix (e.g., temporarily or permanently fix) the second plate-shaped portion 34 to the first plate-shaped portion 32.

[0038] 3, the first protrusion 36 and the second protrusion 38 are formed to have a hollow shape. Therefore, the first protrusion 36 and the second protrusion 38 can be formed by stamping.

[0039] 4, in the embossing device 60 according to one embodiment of the present invention, the die 64 has a first recess 72 having an inner diameter larger than the outer diameter of the main body 68, and a second recess 74 formed at the bottom of the first recess 72, the second recess 74 having an inner diameter smaller than the outer diameter of the main body 68 and larger than the outer diameter of the protrusion 70. Therefore, as shown in FIGS. 5 to 14, when the punch 62 is moved toward the die 64 with a sheet material 80 set in the die 64, the main body 68 presses the sheet material 80 to form a first protrusion 36 that protrudes from a portion of the sheet material 80, and the protrusion 70 presses the sheet material 80 to form a second protrusion 38 that protrudes from the tip of the first protrusion 36. In other words, a two-stage embossing portion 42 having the first protrusion 36 that protrudes from a portion of the sheet material 80 and the second protrusion 38 that protrudes from the tip of the first protrusion 36 can be formed in the sheet material 80.

[0040] Furthermore, the base end 70B of the protrusion 70 is formed by a tapered surface that increases in diameter toward the main body 68 and is curved concavely in a vertical cross section. Therefore, as shown in Fig. 7, just before the main body 68 starts to press the sheet material 80, the tapered surface of the base end 70B of the protrusion 70 suppresses the flow of the material of the sheet material 80, and the sheet material 80 is curved so that a gap 82 is formed between the punch 62 and the sheet material 80 from the base end 70B of the protrusion 70 to the tip of the main body 68. As a result, for example, the timing at which a tensile force F1 acts on the sheet material 80 due to the pressing by the protrusion 70 can be delayed compared to when the base end 70B of the protrusion 70 does not have a tapered surface.

[0041] 10, before the projection 70 begins to be inserted into the second recess 74, the plate material 80 is compressed between the tip of the main body 68 and the bottom of the first recess 72, thereby reducing the tensile force F2 acting on the plate material 80 between the outer peripheral surface of the main body 68 and the inner peripheral surface of the first recess 72. This reduces the tensile force F2 acting on the plate material 80 due to the pressure from the peripheral edge 68A of the tip of the main body 68, thereby preventing the plate material 80 from breaking.

[0042] 10 to 14, the plate material 80 is compressed by the outer peripheral surface of the main body portion 68 and the inner peripheral surface of the first recessed portion 72, and in a state in which the plate material 80 is compressed by the tip of the main body portion 68 and the bottom of the first recessed portion 72, the plate material 80 is pressed by the convex portion 70, thereby forming the second protruding portion 38. Therefore, at the stage in which the second protruding portion 38 is formed, the material of the plate material 80 flows toward the second protruding portion 38, so that the hollow second protruding portion 38 can be formed while preventing the plate material 80 from breaking.

[0043] Furthermore, peripheral edge 68A at the tip end of main body 68 is formed by a tapered surface that increases in diameter toward the base end of main body 68 and is curved convexly in a vertical cross section. Therefore, as shown in Figures 8 to 11, when plate material 80 is pressed by main body 68 to form first protrusion 36, the material of plate material 80 flows smoothly along peripheral edge 68A at the tip end of main body 68, making it possible to form hollow first protrusion 36 while suppressing breakage of plate material 80.

[0044] Furthermore, peripheral edge 72A of the opening of first recess 72 is formed by a tapered surface that increases in diameter toward the bottom of first recess 72 and is curved convexly in a vertical cross section. Therefore, as shown in Figures 8 to 11, when the plate material 80 is pressed by main body 68 to form first protrusion 36, the material of plate material 80 flows smoothly along peripheral edge 72A of the opening of first recess 72, making it possible to form hollow first protrusion 36 while suppressing breakage of plate material 80.

[0045] Furthermore, peripheral edge 70A at the tip of protrusion 70 is formed by a tapered surface that increases in diameter toward base end 70B of protrusion 70 and is curved convexly in a vertical cross section. Therefore, as shown in Figures 11 to 14, when plate material 80 is pressed by protrusion 70 to form second protrusion 38, the material of plate material 80 flows smoothly along peripheral edge 70A at the tip of protrusion 70, making it possible to form hollow second protrusion 38 while suppressing breakage of plate material 80.

[0046] Furthermore, a peripheral edge 74A of the opening of the second recess 74 increases in diameter toward the bottom of the second recess 74 and is formed by a tapered surface that is convexly curved in a vertical cross section. Therefore, as shown in Figures 11 to 14, when the plate material 80 is pressed by the convex portion 70 to form the second protrusion 38, the material of the plate material 80 flows smoothly along the peripheral edge 74A of the opening of the second recess 74, so that the hollow second protrusion 38 can be formed while preventing the plate material 80 from breaking.

[0047] The above describes one embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention.

[0048] The following additional notes are also disclosed regarding the above-described embodiment of the present invention.

[0049] (Appendix 1) An embossing device including a punch and a die, The punch is a main body; a protrusion protruding from a tip end of the main body; and The die is a first recess having an inner diameter larger than an outer diameter of the main body; a second recess formed at a bottom of the first recess, the second recess having an inner diameter smaller than the outer diameter of the main body and larger than the outer diameter of the protrusion; having Launching device. (Appendix 2) The base end of the protrusion is formed by a tapered surface that increases in diameter toward the main body and is curved concavely in a vertical cross section. 10. The projection device of claim 1. (Appendix 3) a peripheral edge portion of the tip end of the convex portion is formed by a tapered surface that increases in diameter toward the base end side of the convex portion and is curved convexly in a vertical cross section; 10. The projection device according to claim 1 or 2. (Appendix 4) The peripheral edge of the tip end of the main body portion is formed by a tapered surface that increases in diameter toward the base end of the main body portion and is curved convexly in a vertical cross section. 4. A projection device according to any one of claims 1 to 3. (Appendix 5) The peripheral edge of the opening of the first recessed portion is formed by a tapered surface that increases in diameter toward the bottom of the first recessed portion and is curved convexly in a vertical cross section. 5. The projection device according to claim 1, (Appendix 6) The peripheral edge of the opening of the second recessed portion is formed by a tapered surface that increases in diameter toward the bottom of the second recessed portion and is curved convexly in a vertical cross-sectional view. 6. A projection device according to any one of claims 1 to 5. (Appendix 7) A method for embossing using the embossing device according to any one of Supplementary Note 1 to Supplementary Note 6, A plate material is set in the die, While moving the punch toward the die, the plate material is pressed by the main body portion and the protrusion portion, a first protrusion protruding from a part of the plate material is formed by pressing the plate material with the main body portion; a second protruding portion protruding from a tip end of the first protruding portion is formed by pressing the plate material with the convex portion; A method of launching including: (Appendix 8) the plate material is pressed by the convex portion until the main body portion starts to press the plate material, such that a gap is formed between the punch and the plate material from the base end of the convex portion to the tip end of the main body portion by bending the plate material immediately before the main body portion starts to press the plate material; The method of launching described in Appendix 7. (Appendix 9) Before the protrusion begins to be inserted into the second recess, a tensile force acting on the plate material between the outer peripheral surface of the main body portion and the inner peripheral surface of the first recess is reduced by compressing the plate material between the tip end of the main body portion and the bottom of the first recess. 10. The method of claim 7 or 8. (Appendix 10) the plate material is compressed by the outer peripheral surface of the main body and the inner peripheral surface of the first recess, and the plate material is compressed by the tip end of the main body and the bottom of the first recess, and in this state, the plate material is pressed by the convex portion, thereby forming the second protrusion. The method of any one of Supplementary Notes 7 to 9. [Explanation of symbols]

[0050] 10...motor, 12...shaft, 14...rotor, 16...stator, 18...holder, 20...center piece, 22...circuit board, 24...circuit case, 26...heat sink, 30...joint structure, 32...first plate-shaped portion, 34...second plate-shaped portion, 36...first protrusion, 38...second protrusion, 40...through hole, 42...two-stage embossed portion, 44...crimping portion, 50...crimping device, 52...Core metal, 54...Caulking tool, 60...Ejection device, 62...Punch, 64...Die, 66...Pressure die, 68...Main body, 68A...Periphery of tip of main body, 70...Convex portion, 70A...Periphery of tip of convex portion, 70B...Base end of convex portion, 72...First recess, 72A...Periphery of opening of first recess, 74...Second recess, 74A...Periphery of opening of second recess, 76...Hole

Claims

[Claim 1] A joining method for joining the first plate-shaped portion of a press-molded product having a first plate-shaped portion, a first protruding portion protruding from the first plate-shaped portion, and a second protruding portion protruding from a tip end of the first protruding portion, the first protruding portion and the second protruding portion being formed in a hollow shape with the inside of the convex portion being hollow, to the second plate-shaped portion, a tip end of the first protrusion abutting against the second plate-shaped portion; inserting the second protruding portion into a through hole formed in the second plate-shaped portion; a crimping portion is formed at the tip of the second protruding portion by compressing the tip of the second protruding portion from both sides in a direction intersecting the protruding direction of the second protruding portion; A bonding method comprising:

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