Riveting method and connector

Abstract

In the present invention, a metal rivet (1a) placed at a position away from the front surface (50b) of a second member to be coupled (50) is moved to the position of a preliminary hole (41), and the rivet (1a) is driven into and reaches the preliminary hole (41) in the order of the second member to be coupled (50) and a first member to be coupled (40). The pre-hole (41) includes a hole portion (43) having a substantially conical or truncated cone-shaped inner wall surface with a thin tapered tip, the rivet (1a) includes a first shaft portion (3) with a thin tip, the depth of the hole portion (43) is deeper than the length of the first shaft portion (3), the first shaft portion (3) has a tip portion (3a1) whose diameter decreases toward the tip side, and the outer peripheral surface of the first shaft portion (3) is provided with an inner wall portion (3a2). A spiral groove (3b) is engraved from the base end side to the tip end side, and the relationship between the depth (H) of the opening (42) and the thickness (T) of the position where the rivet (1a) of the second member (50) to be coupled is 0.25 * T < H < 0.75 * T.

Description

Technical Field

[0001] The present invention relates to a method of driving a rivet and a connector. Background Art

[0002] As a method of mechanically connecting an aluminum alloy lid to an aluminum alloy casting, bolt connection is generally known. In addition, a self-tapping connection (Japanese: セルフタップ締結) is known in which a self-tapping screw is used to form a threaded groove in the joined member while performing connection. On the other hand, as a method of driving a rivet for connecting two members by moving a rivet provided with a spiral groove at high speed, the technique described in Patent Document 1 has been proposed. The technique described in Patent Document 1 is as follows: First, the front surface of one metal plate is overlapped with the back surface of the other metal plate. Next, a metal rivet placed at a position away from the front surface of the other metal plate is moved at high speed without rotation, and the rivet is screwed in while rotating in the order of the other metal plate and one metal plate. The rivet used includes a disk-shaped head and a shaft portion having a thin front end provided at the central portion of the head. Further, a spiral groove is provided on the outer peripheral surface of the shaft portion from the front end side toward the base end side. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-39535 Summary of the Invention Technical Problem to be Solved by the Invention

[0004] However, in the case where the joined members are materials having a thickness such as a plate material or a square timber, when driving a rivet from the front surface of the plate material or the like to connect the two members in a state where the back surface of the plate material or the like is overlapped with the front surface of the square timber or the like, there is a risk of leakage in the connector and insufficient joint strength cannot be obtained. From such a viewpoint, an object of the present invention is to provide a method of driving a rivet and a connector that can suppress the occurrence of leakage in the connector and obtain sufficient joint strength. Technical Solution for Solving the Technical Problem

[0005] In order to solve such a problem, the first invention is a riveting method, comprising: a preparation process, in which the front side of a first connected member having a preparation hole is made to overlap with the back side of a second connected member; and a riveting process, in which a metal rivet placed at a position away from the front side of the second connected member is moved to the position of the preparation hole, so that the rivet is driven into the second connected member and the first connected member in this order and reaches the prepared hole, wherein the prepared hole comprises: a hole portion having a thin conical shape at the front end The rivet comprises a first shaft portion with a thin front end, the first shaft portion having a front end portion with a diameter that decreases toward the front end side, and a groove is engraved on the outer peripheral surface of the first shaft portion from the base end side of the first shaft portion toward the front end side, and when the depth of the opening portion is taken as H and the thickness of the rivet at the insertion position of the second connected member is taken as T, 0.25×T<H<0.75×T is satisfied.

[0006] Furthermore, preferably, the taper angle of the opening is 70° to 110°.

[0007] Preferably, an opening diameter of the hole portion is larger than a diameter of a base end portion of the first shaft portion.

[0008] Preferably, a relationship between an opening diameter φ1 of the hole portion and a diameter φ2 of a base end portion of the first shaft portion is 1.0×φ2<φ1≤1.1×φ2.

[0009] Preferably, the taper angle of the hole is 2° to 10°.

[0010] Preferably, the rivet also includes a head extending from the base end of the first shaft portion, the first shaft portion hangs down from the head, the head has a center portion connected to the first shaft portion and a peripheral portion expanding outward from the center portion, and the diameter of the peripheral portion is larger than the diameter of the first shaft portion.

[0011] Preferably, the head portion is in an umbrella shape in which the peripheral edge portion expands while being inclined toward the first shaft portion.

[0012] Preferably, the thickness of the peripheral portion of the head is 0.1 to 2.0 mm.

[0013] Preferably, the inclination angle of the head is 5° to 30°.

[0014] Preferably, the groove is a spiral groove formed in a spiral shape on the outer surface of the first shaft portion. In the riveting process, the rivet placed at a position away from the front of the second connected part is moved toward the position of the preparatory hole without rotating, so that the rivet is screwed into the preparatory hole while rotating in the order of the second connected part and the first connected part.

[0015] Preferably, the helical angle of the spiral groove is 60° to 360°.

[0016] Preferably, the rivet also includes a second shaft portion extending from the head on the side of the head opposite to the first shaft portion. In the riveting process, an auxiliary component having a retaining portion for retaining the second shaft portion is used, and the rivet is moved to the position of the preparatory hole according to each of the auxiliary components while the second shaft portion is retained by the auxiliary component.

[0017] Preferably, the first coupled member and the second coupled member are formed of aluminum or an aluminum alloy.

[0018] Furthermore, preferably, the first coupled member is formed of aluminum or an aluminum alloy, and the second coupled member is a plate material formed of resin.

[0019] Preferably, the first coupled member is a casting material.

[0020] In addition, the second invention is a connected object, comprising: a first connected member, the first connected member having a preparatory hole; a second connected member, the back side of the second connected member overlaps with the front side of the first connected member; and a rivet, the rivet is made of metal, driven into the preparatory hole in the order of the second connected member and the first connected member; the preparatory hole comprises: a hole portion, the hole portion having an inner wall surface of a substantially conical shape or a substantially truncated cone shape with a tapered tip; and an opening portion, the opening portion expanding in a tapered shape from the hole portion to the front side of the second connected member, the rivet comprises a first shaft portion with a tapered tip, the depth of the hole portion is deeper than the length of the first shaft portion, the first shaft portion is a front end portion having a diameter that decreases toward the front end side, and a groove is engraved on the outer peripheral surface of the first shaft portion from the base end side to the front end side of the first shaft portion. When the depth of the opening portion is H and the thickness of the second connected member at the driving position of the rivet is T, 0.25×T<H<0.75×T is satisfied. Effects of the Invention

[0021] According to the riveting method and the connected object of the present invention, the occurrence of holes in the connected object can be suppressed and sufficient joint strength can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a perspective view of the appearance of a rivet used in an embodiment of the present invention. Figure 2 is a side view of a rivet used in an embodiment of the present invention. Figure 3 1 is a bottom view of a rivet used in an embodiment of the present invention. Figure 4 is corresponding to Figure 3 Longitudinal section view along line IV-IV. Figure 5 This is a side view of another type of rivet used in the embodiment of the present invention. Figure 6 It is a longitudinal sectional view of the connected member used in the embodiment of the present invention. Figure 7 1 is a schematic structural diagram of a riveting device used in a riveting method according to an embodiment of the present invention. Figure 8 This is a diagram showing a state where a rivet is ejected from a riveting device. Fig. 9 It is a longitudinal sectional view of a connected object according to an embodiment of the present invention. Fig. 10A It is a schematic diagram of the method of measuring the pull-out force in the test of the embodiment. Fig. 10B is corresponding to Fig. 10A Longitudinal section view of XB-XB. Fig.11 This is a table showing the experimental results of Experimental Data 1 of the present invention. Fig.12 This is a table showing the experimental results of Experimental Data 2 of the present invention. Fig.13 It is a longitudinal sectional view of a connection object according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are described with reference to the accompanying drawings as appropriate. The present invention is not limited to the following embodiments. In addition, some or all of the components in the embodiments may be appropriately combined. In addition, the accompanying drawings are for conceptually illustrating the present invention, and the sizes and proportions of the components drawn may sometimes differ from the actual situation.

[0024] [About the structure of rivets] The rivet used in the embodiment of the present invention will be described in detail with reference to the drawings. Figures 1 to 4 The rivet 1a shown is driven into two overlapping components of a connection object at high speed and connects the two components. Figure 1As shown, the rivet 1a mainly includes a disc-shaped head 2, a first shaft portion 3 provided in the central portion of one side of the head 2, and a second shaft portion 4 provided in the central portion of the other side of the head 2. The rivet 1a is made of metal, for example, and is manufactured using various materials corresponding to the materials of the components of the connection object. The up and down directions in the following description are appropriately indicated by arrows in each figure. This direction is defined for the convenience of description and does not limit the present invention. In addition, in this specification, the "front side" refers to the side opposite to the back side. Here, although the case of connecting two components using the rivet 1a is described, the connection objects of the rivet 1 can also be more than three components.

[0025] Figure 1 The first shaft portion 3 shown is a portion through which the member of the connection object is penetrated. The first shaft portion 3 has a main body portion 3a hanging down from the head portion 2 and a neck portion 3c formed at the base end of the first shaft portion 3 (the portion connected to the head portion 2). The main body portion 3a has a base end portion 3a2 provided on the base end side and a front end portion 3a1 provided on the front end side. The main body portion 3a is tapered and roughly in the shape of a cannonball. The base end portion 3a2 is roughly cylindrical, and the diameter φ2 of the base end portion 3a2 is constant.

[0026] The tip end portion 3a1 is continuous with the base end portion 3a2 and becomes thinner toward the tip end (the diameter decreases toward the tip end). The tip end portion 3a1 has a larger diameter than the conical portion 6 ( Figure 2 ) is more like a raised portion 5 that bulges outward, and the conical shape 6 is formed by the imaginary bottom surface 3a4 (imaginary interface between the base end 3a2 and the front end 3a1) assumed at the base end of the front end 3a1 and the vertex of the front end 3a3. The raised portion 5 is a portion that contacts the inner wall surface of the preparatory hole 41 described later, and is a portion where the interference is the maximum interference. In this embodiment, although the front end 3a3 is a flat surface, as the front end 3a1 as a whole becomes pointed toward the front end 3a3, the resistance when the connected member 30 is driven in can be reduced. In addition, the front end 3a3 can also be a sharp shape without a flat surface.

[0027] Reference Figure 2 , Figure 4 , Figure 5The shapes of the front end portion 3a1 and the raised portion 5 are described. When the main body 3a is observed in section, the side portion 3a61 on one side of the front end portion 3a1 extends from the end 3a51 on the side of the front end portion 3a1 on the side of the base end portion 3a2 toward the front end 3a3 side, and as the side portion 3a61 moves toward the front end 3a3 side, the arc CA1 that bulges outwards toward the center axis is reduced in diameter. Similarly, the side portion 3a62 on the other side of the front end portion 3a1 also extends from the end 3a52 on the side of the front end portion 3a1 on the side of the other side of the base end portion 3a2 toward the front end 3a3 side, and as the side portion 3a62 moves toward the front end 3a3 side, the arc CA2 that bulges outwards toward the center axis is reduced in diameter. Then, the side portions 3a61 and 3a62 of the front end portion 3a1 extending from the ends 3a51 and 3a52 on both sides of the base end portion 3a2 meet at the front end 3a3. The main body 3 a is a structure having an outer shape of a rotating body obtained by rotating the distal end portion 3 a 1 and the proximal end portion 3 a 2 having the above-described cross-sectional structure.

[0028] More specifically, in the case of cross-sectional observation, the circles connected to the imaginary straight lines L1 and L2 passing through the side surfaces of the base end portion 3a2 at the end portions 3a51 and 3a52 of the side surfaces of the base end portion 3a2 are respectively referred to as imaginary circles VC1 and VC2. The arcs CA1 and CA2 of the side surfaces 3a61 and 3a62 constituting the front end portion 3a1 are part of the imaginary circles VC1 and VC2. The size of the arcs CA1 and CA2 of the side surfaces constituting the front end portion 3a1 can be represented by the radius of the imaginary circles VC1 and VC2, i.e., the curvature radius R1. In the present embodiment, the curvature radius R1 of the arcs CA1 and CA2 constituting the side surfaces of the front end portion 3a1 and the raised portion 5 is 22.27 mm, and the radius R2 of the base end portion 3a2 is 2 mm. The relationship with the radius R2 of the base end portion 3a2 is R1=R2×11.135.

[0029] The curvature radius R1 of the arcs CA1 and CA2 is preferably 14 mm or more, more preferably 18 mm or more, and more preferably 20 mm or more, and preferably 40 mm or less, more preferably 30 mm or less, more preferably 26 mm or less, and particularly preferably 24 mm or less. The relationship between the curvature radius R1 of the arcs CA1 and CA2 constituting the front end portion 3a1 and the raised portion 5 and the radius R2 of the base end portion 3a2 is preferably R2×5≤R1, more preferably R2×7≤R1, more preferably R2×9≤R1, and particularly preferably R2×10≤R1. In addition, the relationship between the curvature radius R1 and the radius R2 is preferably R1≤R2×20, more preferably R1≤R2×15, more preferably R1≤R2×13, and particularly preferably R1≤R2×12. Since the curvature radius R1 is in the relationship above the lower limit, the length of the front end portion 3a1 becomes sufficiently long, and it is easy to ensure the rivet contact length between the inner wall surface of the preparatory hole 41 and the first shaft portion 3. In addition, since the curvature radius R1 is below the above-mentioned upper limit, the protrusion amount of the protrusion 5 becomes sufficiently large, and it is easy to ensure the maximum interference between the inner wall surface of the prepared hole 41 and the first shaft portion 3. Therefore, since the relationship between the curvature radius R1 and the radius R2 satisfies the above-mentioned relationship, the pull-out resistance caused by the contact between the prepared hole 41 and the first shaft portion 3 becomes large, and the leak-proof property can be improved.

[0030] A groove is engraved on the outer peripheral surface of the first shaft portion 3 from the base end side toward the front end side of the first shaft portion 3. More specifically, the groove engraved on the first shaft portion 3 is a spiral groove 3b formed in a spiral shape on the outer surface of the first shaft portion 3. The spiral groove 3b is formed from the front end portion 3a1 of the main body portion 3a toward the base end portion 3a2. Figure 2 As shown, the neck portion 3c is formed to have a smaller diameter than the diameter of the main body portion 3a. In addition, the neck portion 3c may not be provided on the first shaft portion 3. In this case, the spiral groove 3b is preferably formed from the front end to the base end of the first shaft portion 3. In addition, the lengths (ratio of the lengths) of the front end portion 3a1, the base end portion 3a2, and the neck portion 3c can be appropriately set to match the shape of the preparatory hole 41.

[0031] The head 2 is a part used to prevent the rivet 1a from being buried in the member of the connection object and to suppress the leak when the rivet 1a is driven into the member of the connection object. The shape and size of the head 2 are not particularly limited, as long as the energy (kinetic energy) generated by the driving speed of the rivet 1a can be absorbed by the elastic deformation of the head 2. The head 2 here extends from the base end of the first shaft portion 3. The head 2 has a central portion 2a connected to the first shaft portion 3 and a peripheral portion 2b that expands from the central portion 2a to the outside. The diameter of the peripheral portion 2b is larger than the diameter of the first shaft portion 3. Although the shape of the head 2 is not particularly limited, in the present embodiment, the peripheral portion 2b is an umbrella shape that is expanded while tilting downward toward the first shaft portion 3. In the present embodiment, although the head 2 is circular when viewed from above, it can also be elliptical when viewed from above or polygonal when viewed from above.

[0032] The spiral groove 3b is formed so as to rotate rightward (clockwise) when viewed from above when drawn from its base end toward the front end. Alternatively, the spiral groove 3b may be formed so as to rotate leftward (counterclockwise) when viewed from above. When a member of a connection object is driven in, the spiral groove 3b plays a role in digging out the member of the connection object while rotating the rivet 1a.

[0033] In the following description, the angle of the spiral groove 3b around the first shaft portion 3 is represented by "helical angle β" ( Figure 3 ). When the helical angle is 90°, the spiral groove 3b rotates around the first shaft portion 3 by 1 / 4 of a circle, and when the helical angle is 720°, the spiral groove 3b rotates around the first shaft portion 3 by 2 circles. Figures 1 to 4 , the case where the helical angle is 180° is shown, and the helical groove 3b makes a half turn around the first shaft portion 3. The appropriate value of the helical angle β of the helical groove 3b will be described later.

[0034] The cross-sectional shape, width, and depth of the spiral groove 3b can be appropriately set within the range in which the spiral groove 3b can play the role of digging the member of the connection object. Figure 4 As shown, the spiral groove 3b here is roughly arc-shaped when observed in cross-section, and the front end becomes thinner as it moves toward the front end side (a shape in which the width becomes narrower or shallower as it moves toward the front end side). In addition, the spiral groove 3b can also be provided in a part of the main body 3a. In addition, a plurality of spiral grooves 3b can also be provided in the main body 3a.

[0035] The second shaft portion 4 extends from the central portion 2 a of the head portion 2 in a direction opposite to the first shaft portion 3 , and is, for example, a substantially cylindrical portion.

[0036] Figure 5A rivet 1b is shown as a modified example of the rivet 1a. The rivet 1b is different from the rivet 1a in that the thickness of the peripheral edge portion 2b of the head portion 2 of the rivet 1a is substantially constant. Figure 5 The figure shows that a part of the head 2 is cut off, and the thickness of the peripheral edge 2b of the rivet 1b is tapered. The other structures are the same as those of the rivet 1a. Figure 5 Marked with Figures 1 to 4 The same symbols are used and detailed description is omitted.

[0037] [About the connected parts] Figure 6 The connected member 30 shown is a member to be connected by the rivet 1a or rivet 1b. The connected member 30 includes a first connected member 40 and a second connected member 50. That is, the first connected member 40 and the second connected member 50 are connected by driving the rivet 1a or rivet 1b. The first connected member 40 and the second connected member 50 are connected by the rivet 1a or rivet 1b in a state where the back surface 50a of the second connected member 50 overlaps with the front surface 40a of the first connected member 40 having the prepared hole 41.

[0038] In the present embodiment, the first connected member 40 is a block material in the shape of a quadrangular prism. The shape of the first connected member 40 is not particularly limited as long as it is a member having at least a thickness to be able to set the preparatory hole 41 described later, and it may also be other shapes. The first connected member 40 is, for example, a columnar member having a circular, elliptical, polygonal or irregular cross-sectional shape. Preferably, the length of the first connected member 40 is longer than the length of the first shaft portion 3 relative to the direction in which the rivets 1a, 1b are inserted. In addition, the first connected member 40 may also be a member in which two or more plates are overlapped to maintain the thickness.

[0039] The preparatory hole 41 includes an opening portion 42 that opens on the front side 40a of the first connected member 40 and a hole portion 43 that is continuous with the opening portion 42. The hole portion 43 has an inner wall surface that is generally conical or generally truncated cone-shaped with a tapered front end. The opening portion 42 is formed so that the inner wall surface has a taper angle θ2 and is generally conical in shape as the diameter decreases from the front side 40a of the first connected member 40 toward the inner side. The hole portion 43 is formed so that the inner wall surface has a taper angle θ3 and is generally conical or generally truncated cone-shaped as the diameter decreases from the front side 40a of the first connected member 40 toward the inner side. The depth of the hole portion 43 is deeper than the length of the first shaft portion 3. The opening diameter φ1 of the hole portion 43 is greater than the diameter φ2 of the base end portion 3a2 of the first shaft portion 3 ( Figure 2) is larger. In addition, the depth of the preparatory hole 41 may be the same as the length of the first shaft portion 3, or may be shorter than the length of the first shaft portion 3. When the depth of the preparatory hole 41 is made greater than the length of the first shaft portion 3, the rivet 1a can be smoothly inserted. In the case where the depth of the preparatory hole 41 is shorter than the length of the first shaft portion 3, the front end of the first shaft portion 3 is driven into the bottom of the preparatory hole 41 to improve the joining strength, but it is preferably set to a degree that does not hinder insertion. The preparatory hole 41 can be formed in a pre-set manner when forming the first connected member 40, or it can be formed by performing a tapered hole opening process on the first connected member 40 using a tool such as a drill, a reamer or an end mill.

[0040] In the present embodiment, the second connected member 50 is a flat plate. As long as the second connected member 50 is at least long enough for the first shaft portion 3 to pass through, the shape and the like are not limited, for example, it is a plate-shaped member having a thickness thinner than the length of the first shaft portion 3. The materials of the first connected member 40 and the second connected member 50 are not particularly limited, and are formed of metals (for example, aluminum, aluminum alloy, magnesium, magnesium alloy, copper, copper alloy, titanium, titanium alloy, etc.) that can be connected with rivets 1a. The first connected member 40 can be, for example, a casting material. In this case, it is preferred that in the forming process of the first connected member 40, a preparatory hole 41 is also formed in advance by casting. The second connected member 50 can be, for example, a plate formed of metal or resin. In addition, the casting material is a material based on the premise that a liquid metal called molten metal is heated and melted and then injected into a mold and then cooled and hardened. In addition, in this case, the casting material is preferably (composed of) an AlSi-Cu alloy (casting material composed of), and more preferably JI SH5302 ADC 12.

[0041] [About riveting method] A riveting method using the rivets 1a and 1b according to the embodiment of the present invention will be described in detail with reference to the drawings. Figure 7 The riveting device 10 shown drives a rivet 1 a (or a rivet 1 b (hereinafter the same)) at high speed into two overlapping members (joined members 30 ) of a joining object, thereby joining the joined members 30 .

[0042] like Figure 7 As shown, the riveting device 10 includes an air compressor 11, a first needle valve 12, a booster 13, a second needle valve 14, a solenoid valve 15, a rivet ejection unit 16, and a hose 17 connecting these components.

[0043] The air compressor 11 is a device for compressing and delivering air. The first needle valve 12 is a valve for the supercharger 13. The supercharger 13 is a device for supercharging the air delivered from the air compressor 11. The second needle valve 14 and the solenoid valve 15 are valves for regulating the compressed air delivered to the rivet ejection unit 16.

[0044] The riveting method of this embodiment includes a preparation step and a riveting step. In the preparation step, the back surface 50a of the second connected member 50 is overlapped with the front surface 40a of the first connected member 40 having the preparation hole 41 (forming a riveting hole). Figure 6 In the riveting process, the riveting device 10 is used to place the front surface 50b ( Figure 6 ) is moved toward the position of the preparatory hole 41, so that the rivet 1a is driven into the preparatory hole 41 in the order of the second connected member 50 and the first connected member 40.

[0045] That is, the rivet ejection unit 16 is in the shape of a long cylinder, and uses the pressure (air pressure) of compressed air to eject the ejection member 20 contained therein toward the connected member 30. The ejection member 20 may include the rivet 1a or may be composed of only the rivet 1a. Figure 8 As shown, an auxiliary member 21 is attached to the rivet 1a and used as the ejection member 20. The auxiliary member 21 is a member for driving the rivet 1a into the connected member 30 in a stable state. In addition, the auxiliary member 21 is a member for increasing the kinetic energy of the rivet 1a ejected together with the auxiliary member 21. For example, when the rivet 1a is lightweight, the auxiliary member 21 is used to adjust the weight.

[0046] The material, shape, and quality of the auxiliary member 21 can be appropriately set as long as the rivet 1a can be driven into the connected member 30 in a stable state. Figure 8 As shown, the auxiliary member 21 here is cylindrical with a substantially cylindrical inner peripheral surface 21b formed inside, and the second shaft portion 4 is inserted into the inner peripheral surface 21b from the opening portion 21a on one side to fix the rivet 1a to the auxiliary member 21. That is, the inner peripheral surface 21b serves as a retaining portion to retain the second shaft portion 4. Compressed air is sucked into the inside from the opening portion 21c on the other side, and the ejection member 20 is ejected from the rivet ejection portion 16 at a high speed using the pressure of the sucked air. In addition, in advance, the central axis of the first shaft portion 3 of the rivet 1a to which the ejection member 20 in the rivet ejection portion 16 is installed should be aligned with the central axis of the preparatory hole 41 of the connected member 30 located below it. In addition, the rivet 1a can be fixed to the auxiliary member 21 in a form without providing the second shaft portion 4.

[0047] The ejection member 20 ejected from the rivet ejection unit 16 moves at high speed in the air without rotating and reaches the connected member 30. The rivet 1a that reaches the connected member 30 is engraved on the first shaft portion 3 (see Figure 1 ) is screwed into the spiral groove 3b and driven into the connected member 30 while rotating. Then, by inserting the first shaft portion 3 as a whole into the connected member 30, the head portion 2 (see Figure 1 ) abuts against the connected member 30 to complete the riveting. Thus, the connected member 30 consisting of two components is connected. As a result, the connected member 30 is connected by the rivet 1a, and becomes as shown in FIG. Fig. 9 The connection object 60 is shown in a cross-sectional view.

[0048] [About numerical range] Next, the numerical ranges of the respective parts suitable for the riveting method of the present embodiment will be described. First, the height (depth) H ( Figure 6 ) relative to the thickness T of the second connected member 50 at the driving position of the rivets 1a, 1b ( Figure 6 ), usually there is a relationship of "0.25×T<H<0.75×T". The relationship between the height H of the opening 42 and the thickness T of the second connected member 50 is preferably 0.3×T<H, more preferably 0.35×T<H, further preferably 0.4×T<H, and particularly preferably 0.45×T<H. In addition, preferably, the relationship between the height H of the opening 42 and the thickness T of the second connected member 50 is preferably H<0.7×T, more preferably H<0.65×T, further preferably H<0.6×T, and particularly preferably H<0.55×T. The effects produced by the relationship that the height H of the opening 42 exceeds the above lower limit relative to the thickness T of the second connected member 50, and the effects produced by the relationship that the height H of the opening 42 is lower than the above upper limit relative to the thickness T of the second connected member 50 will be described later.

[0049] In addition, the taper angle θ2 ( Figure 6 ) is preferably 70° to 110°, more preferably 75° to 105°, further preferably 80° to 100°, and particularly preferably 85° to 95°. The effects produced by the taper angle θ2 of the opening 42 being above the lower limit and the effects produced by the taper angle θ2 of the opening 42 being below the upper limit will be described later.

[0050] In addition, the diameter (ie, opening diameter) φ1 of the entrance portion of the hole portion 43 of the preliminary hole 41 ( Figure 6 ) and the diameter φ2 of the base end portion 3a2 of the main body portion 3a ( Figure 2 ) is preferably 1.0×φ2<φ1≤1.1×φ2, more preferably 1.01×φ2<φ1≤1.09×φ2, and further preferably 1.02×φ2<φ1≤1.08×φ2.

[0051] In addition, the inclination of the inner wall surface of the hole portion 43 of the preliminary hole 41 (ie, the taper angle θ3) ( Figure 6) is preferably 2° to 10°, more preferably 3° to 9°, and further preferably 4° to 8°.

[0052] In addition, the thickness of the peripheral edge portion 2b of the head portion 2 of the rivet 1a or rivet 1b (see Figure 4 as well as Figure 5 The thickness of the rivet 1b (the thickest part) is preferably 0.2 mm to 2.0 mm, more preferably 0.3 mm to 1.8 mm, and even more preferably 0.5 mm to 1.5 mm.

[0053] In addition, if Figure 4 As shown in FIG. 1 , the inclination angle θ1 of the head 2 of the rivet 1a is the angle from the imaginary plane perpendicular to the axis of the rivet 1a to the lower surface of the peripheral portion 2b. Figure 5 As shown, the inclination angle θ1 of the head 2 of the rivet 1b is the angle from the imaginary plane perpendicular to the axis of the rivet 1b to the lower surface of the peripheral portion 2b. When the inclination angles of the upper surface and the lower surface of the peripheral portion 2b are different, as in the rivet 1b, the inclination angle of the lower surface is adopted. This is because it can be expected that the lower surface side contributes to the leak-proof property. The inclination angle θ1 is preferably 5° to 30°, more preferably 10° to 25°, and further preferably 15° to 20°.

[0054] In addition, the helix angle β (refer to Figure 3 , as mentioned above) is preferably above 60°, more preferably above 120°, further preferably above 180°, and particularly preferably above 240°. In addition, the helix angle β is preferably below 360°, more preferably below 330°, and further preferably below 300°. Since the helix angle β is above the above lower limit value, the tensile strength exerted by the first connected member 40 and the second connected member 50 entering the spiral groove 3b of the rivet 1 and engaging therewith becomes easy to improve. In addition, since the helix angle β is below the above upper limit value, when the rivets 1a and 1b are driven in, the rivets 1a and 1b are affected by the spiral groove 3b and rotate smoothly while becoming easy to screw into the first connected member 40 and the second connected member 50.

[0055] [About the effect] The effects of the above-described embodiments and examples will be described. Conventionally, there is known a method for connecting two plates using a rivet engraved with a spiral groove (Patent Document 1 above). In the case of this background technology, by screwing the rivet in while rotating, the two metal plates enter the spiral groove of the rivet and mesh, thereby increasing the connection force. More specifically, the connected member consisting of the upper plate and the lower plate into which the rivet is driven is deformed in a manner to form a protrusion in the shape of a flame vent facing the driving direction, and the connected member cut by the spiral groove is wound around the shaft along the spiral groove.

[0056] Thus, in this background technology, it is assumed that the plates are connected to each other, but it is not assumed that the connected member on the lower side is a block-shaped square material, etc. Therefore, when trying to connect the plate, etc. and the square material, etc. using a rivet engraved with a groove, sometimes a hole is generated from the connected object after the connection. This is because, when the rivet is driven into the connected member in a state where the plate, etc. and the square material, etc. overlap, the connected member (plate, etc.) on the upper side is deformed in the driving direction, and the square material, etc. on the lower side is cut by the groove and deformed in the square material, etc. around the rivet. That is, there is no space for the components to retreat due to the deformation of the two connected members between the connected member on the upper side and the square material, etc. as the connected member on the lower side. Therefore, since the connected member on the upper side is deformed in a floating manner accompanying the driving of the rivet, and a space is generated between the two connected members, a hole is generated.

[0057] In this embodiment, the rivets 1a and 1b are moved toward the position of the preliminary hole 41 in a state where the front surface 40a of the first connected member 40 having the preliminary hole 41 overlaps with the back surface 50a of the second connected member 50, and the rivets 1a and 1b are driven into the second connected member 50 and the first connected member 40 in the order of the preliminary hole 41. In addition, the preliminary hole 41 includes a hole portion 43 and an opening portion 42, wherein the hole portion 43 has an inner wall surface of a tapered cone-shaped substantially conical shape or a substantially truncated cone shape, and the opening portion 42 expands into a cone shape from the hole portion 43. Then, the height (depth) H of the opening portion 42 is in the relationship of "0.25×T<H<0.75×T" with respect to the thickness T of the driving position of the rivets 1a and 1b of the second connected member 50.

[0058] Thus, according to the present embodiment, the second connected member 50 is driven by the rivets 1a and 1b so that the second connected member 50 into which the rivets 1a and 1b are driven is deformed so that a crater-shaped protrusion is formed toward the first connected member 40. In addition, the rivets 1a and 1b are driven by the first connected member 40 so that the inner wall surface of the component of the preliminary hole 41 of the first connected member 40 into which the rivets 1a and 1b are driven is cut by the groove, and a part of the cut inner wall surface of the component of the preliminary hole 41 is placed in the groove. In addition, in a state where the back surface 50a of the second connected member 50 overlaps with the front surface 40a of the first connected member 40, an opening 42 is provided on the front surface 40a of the first connected member 40, so that the space of the opening 42 surrounded by the opening 42 of the first connected member 40 and the back surface 50a of the second connected member 50 is filled with the component of the second connected member 50 deformed into a crater-shaped protrusion and a part of the cut first connected member 40. At this time, since the relationship of "0.25×T<H" is established, sufficient space can be secured for accommodating the member generated by the deformation of the connected member 30 in the space of the opening 42, so that the second connected member 50 can be prevented from floating due to contact with the member generated by the deformation of the connected member 30 and the space between the first connected member 40 and the second connected member 50 can be prevented from expanding, thereby improving the leakage prevention. In addition, since the relationship of "H<0.75×T", the connected member 30 is connected in a state where the member generated by the deformation of the connected member 30 is filled in the space of the opening 42, thereby improving the leakage prevention. In addition, since the relationship of "H<0.75×T", when the member generated by the deformation of the connected member 30 is filled in the space of the opening 42, an excessive gap will remain in the opening 42 between the first connected member 40 and the second connected member 50, and the second connected member 50 is easily deformed when a load is applied after the connected member 30 is connected, thereby preventing the joint strength from being reduced. In other words, due to the relationship of "H<0.75×T", the second connected member 50 overlapping the first connected member 40 can be supported by the component generated by the deformation of the connected member 30 filled in the opening portion 42. Therefore, the deformation of the second connected member 50 when a load is applied after the connection can be suppressed, thereby improving the joint strength.

[0059] Thus, according to the present embodiment, by making the first connected part 40 and the second connected part 50 contact with the rivets 1a and 1b due to the driving of the rivets 1a and 1b and filling the components thus produced into the opening 42 and the interior of the spiral groove 3b, the rivets 1a and 1b can be made to fit tightly against the first connected part 40 and the second connected part 50, and a method for manufacturing a connecting part having improved leakage resistance and sufficient joint strength and a connecting object 60 can be provided.

[0060] Furthermore, by providing the grooves in the first shaft portion 3, when the rivets 1a and 1b are driven in, the material of the first connected member 40 is cut off by the grooves. Here, in the case of a screw, since the thread teeth are provided, the circumferential length is enlarged according to the height of the thread teeth. In the present embodiment, since the circumferential length of the first shaft portion 3 does not change even when the grooves are provided on the outer circumferential surface of the first shaft portion 3, it is possible to suppress the deformation of the first connected member 40 around when the rivets 1a and 1b are driven in. In addition, part of the material cut off by driving the rivets 1a and 1b is received in the grooves, and the stress generated by the deformation of the first connected member 40 can be alleviated. Therefore, while suppressing the occurrence of cracks in the first connected member 40, the rivets 1a and 1b can be inserted into the prepared holes 41 to connect the connected member 30. In addition, in the case of self-tapping connection using self-tapping screws, the shape of the prepared hole 41 applied to the aluminum alloy casting is not required to be highly accurate, and the shortening of the mold life of the connected member 30 can be suppressed.

[0061] In addition, the taper angle θ2 of the opening 42 is 70° to 110°. Thus, the leak-proofness can be improved. Since the taper angle θ2 of the opening 42 is above the lower limit value, sufficient space can be ensured for accommodating the components generated by the deformation of the connected part 30 in the space of the opening 42, thereby improving the leak-proofness. In addition, since the taper angle θ2 of the opening 42 is below the upper limit value, the connected part 30 can be connected in a state where the components generated by the deformation of the connected part 30 are filled in the space of the opening 42, and the second connected part 50 overlapping the first connected part 40 can be supported, thereby improving the leak-proofness and improving the joint strength.

[0062] The opening diameter φ1 of the hole portion 43 of the preliminary hole 41 is larger than the diameter φ2 of the base end portion 3a2 of the first shaft portion 3. Thus, when the rivets 1a and 1b are driven in, the load between the opening portion 42 of the preliminary hole 41 and the first shaft portion 3 of the rivets 1a and 1b can be suppressed from increasing, and the first shaft portion 3 can be smoothly inserted into the preliminary hole 41.

[0063] In addition, preferably, the relationship between the opening diameter φ1 of the hole portion 43 and the diameter φ2 of the base end portion 3a2 of the first shaft portion 3 is 1.0×φ2<φ1≤1.1×φ2. Thus, when the rivets 1a and 1b are driven in, the load between the opening portion 42 of the preliminary hole 41 and the first shaft portion 3 of the rivets 1a and 1b can be suppressed from increasing, and the first shaft portion 3 can be smoothly inserted into the preliminary hole 41.

[0064] In addition, preferably, the taper angle θ3 of the hole 43 is 2° to 10°. Thus, the inner wall surface of the tapered hole 43 contacts the front end 3a1 whose diameter decreases toward the front end side, thereby deforming the connected member 30 and enabling connection by the rivets 1a and 1b.

[0065] In addition, the rivets 1a and 1b also include a head 2 having a central portion 2a and a peripheral portion 2b, and the diameter of the peripheral portion 2b of the head 2 is larger than the diameter of the first shaft portion 3. Thus, the head 2 is elastically deformed and closely attached to the front of the connected member 30, and the leakage resistance of the connected object 60 can be further improved. That is, the head 2 is a part where the rivets 1a and 1b are firmly attached to the front of the connected member 30 when the connected member 30 is driven. By bearing the energy (kinetic energy) generated by driving the rivets 1a and 1b, the head 2 is elastically deformed and remains firmly in close contact with the front of the connected member 30 to support air tightness. In addition, since the rivets 1a and 1b are connected to the connected member 30, the head 2 remains in an elastically deformed state. In addition, the peripheral portion 2b of the head 2 also serves as a stopper when the rivets 1a and 1b are driven, and can absorb kinetic energy.

[0066] Furthermore, the head 2 has an umbrella shape in which the peripheral edge portion 2b expands while being inclined toward the first shaft portion 3, so that the leakage prevention property of the connection object 60 can be further improved.

[0067] Furthermore, since the thickness of the peripheral edge portion 2b of the head portion 2 is within a numerical range of 0.1 mm to 2.0 mm, the leak-proof property of the connection object 60 can be further improved. Furthermore, since the inclination angle θ1 of the head 2 is within the numerical range of 5° to 30°, the leakage-proof property of the connection object 60 can be further improved.

[0068] Furthermore, the groove engraved on the first shaft portion 3 is a spiral groove 3b formed in a spiral shape on the outer surface of the first shaft portion 3. In the riveting process, the rivet 1a or rivet 1b placed at a position away from the front surface 50b of the second connected member 50 is moved to the position of the prepared hole 41 without rotating, and the rivet 1a or rivet 1b is screwed in the order of the second connected member 50 and the first connected member 40 while rotating and reaching the prepared hole 41. Therefore, by the rotation of the rivet 1a or rivet 1b, the spiral groove 3b can cut off the front material of the connected member 30 and fill the prepared hole 41. In addition, the material of the first connected member 40 and the second connected member 50 cut off by the spiral groove 3b can be kept inside the spiral groove 3b, and the excess material can be suppressed from flowing into the space between the rivets 1a, 1b and the prepared hole 41. Therefore, as the rivets 1a and 1b are driven in, the first connected member 40 is suppressed from expanding and deforming due to the volume of the rivets 1a and 1b interfering with the first connected member 40 and the second connected member 50, and it becomes easy to suppress cracks in the first connected member 40. Here, when the first connected member 40 is a low-stretch aluminum alloy casting, the suppression of cracks caused by the spiral groove 3b is more effective.

[0069] Furthermore, in the riveting process, the auxiliary member 21 having the holding portion (inner peripheral surface 21b) for holding the second shaft portion 4 is used, and the rivet 1a or rivet 1b is moved to the position of the prepared hole 41 according to each auxiliary member 21 while the second shaft portion 4 is held by the auxiliary member 21. Therefore, since the weight of the rivet 1a or rivet 1b is increased by the auxiliary member 21, the kinetic energy when the rivet 1a or rivet 1b is driven in can be increased. Therefore, the rivets 1a and 1b can be driven in more efficiently by using the auxiliary member 21.

[0070] Furthermore, when the first connected member 40 is a cast material, since the preliminary hole 41 can be formed in advance in the casting stage, the step of forming the preliminary hole 41 in the first connected member 40 by drilling can be omitted, and productivity can be improved.

[0071] <Others> Although the embodiment of the present invention has been described above, the design can be appropriately changed within the scope not departing from the gist of the present invention. In the present embodiment, although the rivets 1a and 1b are ejected into the connected member 30 by using the pressure of air, other methods may be used to drive the rivets 1a and 1b into the connected member 30. For example, a substance other than air may be used to apply pressure to the rivets 1a and 1b, and the rivets 1 and 1b may be driven into the connected member 30 by the action of a mechanism (for example, the reciprocating motion of a piston). [Example]

[0072] Next, an embodiment of the present invention is described. In this embodiment, experiments of experimental data 1 and 2 are conducted to understand the characteristics of the rivet 1a and the rivet 1b according to the present invention. In the experimental data 1 and 2, under various conditions, with respect to a plurality of embodiments and a plurality of comparative examples relative to these embodiments, the rivet driving device 10 is used to drive the rivet 1a or the rivet 1b into the connected member 30, and a connected object 60 ( Fig. 9 ), and various evaluations are performed with respect to the connection object 60 ( Figure 11 to Figure 12 ).

[0073] [evaluate] <Presence of cracks> The presence or absence of cracks in the connected product 60 was visually checked. A case where cracks occurred in the connected product 60 was evaluated as "×", and a case where no cracks occurred was evaluated as "○".

[0074] <Vulnerability Testing> On the front side 50b of the second connected part 50 of the connection 60, a resin clamp is arranged in a manner covering the head 2 and the first shaft part 3 as a whole. After the resin clamp is arranged, the test body is prepared by pressurizing the resin clamp toward the second connected part 50 and placing it in a state where air does not leak from between the resin clamp and the second connected part 50. While the test body is immersed in water, air is blown into the inside of the resin clamp at a pressure of 0.3MPa from the front side 50b to perform pressurization. The presence or absence of leaks is evaluated by confirming the generation of bubbles from the joint surface of the first connected part 40 and the second connected part 50. The case where no bubbles are generated within one minute is "good", the case where the number of bubbles generated within one minute is 5 or less is "acceptable", and the case where the number of bubbles generated within one minute is 6 or more is "unacceptable". A vulnerability test was conducted on the three connected objects. If all three connected objects were good, it was evaluated as "○", if at least one of the three connected objects was good and the others were acceptable or unacceptable, it was evaluated as "△", and if all three connected objects were unacceptable, it was evaluated as "×".

[0075] <Tensile Strength> like Fig. 10A , Fig. 10BAs shown, the first connected object 40 of the connection 60 is located on the lower side, the second connected object 50 is located on the upper side, and the lower end side of the second connected object 50 is fixed with a specified clamp (not shown). In this state, a pulling tester (Autograph, AG-50kNX, manufactured by Shimadzu Corporation) is used to apply an upward lifting force to both ends of the first connected member 40 to perform a pull-out test. The crosshead speed of the tensile testing machine is set to 3mm / min. In the pull-out test, the load until the rivet 1a and the second connected member 50 are pulled out from the first connected member 40 is measured, and the numerical value representing the maximum load is used as the pulling strength of the connection 60. As a result, the pulling strength of the connection 60 is evaluated as "○" when it exceeds 2500N, "△" when it is 2000N to 2500N, and "×" when it is less than 2000N.

[0076] [Experimental data 1] In experimental data 1, as referenced Figure 6 As described above, the back surface 50a of the plate-shaped second connected member 50 is overlapped with the front surface 40a of the quadrangular prism-shaped first connected member 40 having the prepared hole 41. In this state, as shown in FIG. Figure 7 , Figure 8 As described, the rivet 1a with the auxiliary member 21 is driven into the second connected member 50 and the first connected member 40 in this order using the riveting device 10 so that the rivet 1a reaches the prepared hole 41. In this way, the first connected member 40 and the second connected member 50 are connected by the rivet 1a to obtain the connected object 60.

[0077] In each embodiment and comparative example of Experimental Data 1, reference Figure 1 to Figure 5 The rivet 1a or rivet 1b described. In the rivets 1a and 1b, the length of the front end portion 3a1 of the main body 3a is 9 mm, and the diameter φ2 of the root portion of the front end portion 3a1 is 4 mm. In addition, when observed in side section, the radius of curvature R1 of the arc constituting the front end portion 3a1 of the first shaft portion 3 and the raised portion 5 is 22.5 (mm). In addition, the length of the base end portion 3a2 of the main body 3a is 3 mm, the diameter φ2 of the base end portion 3a2 is 4 mm, and the radius R2 of the base end portion 3a2 is 2 mm. In addition, the spiral angle β of the spiral groove 3b is 180°. In addition, the length of the neck 3c is 2 mm, and the diameter of the neck 3c is 3 mm. In addition, the length of the second shaft portion 4 is 10 mm, and the diameter of the second shaft portion 4 is 3 mm. In the rivet 1a, the length (height) of the head 2 in the long axis direction is 3 mm, the inclination angle θ1 of the head 2 is 20°, and the thickness of the peripheral portion 2b is 1 mm. In the rivet 1b, the length (height) of the head 2 in the long axis direction is 2.4 mm, the inclination angle θ1 of the head 2 is 10°, the thickness of the peripheral portion 2b near the center is 1 mm, and the thickness at the peripheral end is 0.2 mm.

[0078] The first connected member 50 is a block material having a square cross section of 12 mm in length and 12 mm in width and a quadrangular prism shape of 35 mm in height. The taper angle θ3 of the hole portion 43 of the prepared hole 41 is ( Figure 6 ) is 5°. ADC12 is used as the material of the first connected member 40.

[0079] The second connected member 40 is a plate having a length of 80 mm, a width of 30 mm, and a thickness of 2.0 mm. A5052-H34 is used as the material of the second connected member 50 .

[0080] In the rivet driving device 10, the air pressure of the air compressor 11 was set to 0.75 MPa. In addition, the driving speed of the rivet driving device 10 was set to 70 m / sec. The weight of the auxiliary member 21 is approximately 14.4 g.

[0081] exist Fig.11 In the experimental data 1, in each embodiment and comparative example, the rivet 1a or the rivet 1b is selected, and the inclination angle θ1 of the head 2 of the rivet 1a (or the rivet 1b) is Figure 2 Regarding the rivet 1b, the inclination angle of the lower side of the peripheral portion 2b is defined as the inclination angle θ1), the thickness of the peripheral portion 2b of the head 2 (the thickness of the thinnest peripheral end of the rivet 1b), the opening diameter φ1 of the hole portion 43 of the preparation hole 41 ( Figure 6 ), the taper angle θ2 of the opening 42 of the preparation hole 41 ( Figure 6 ), the height (depth) H of the above-mentioned opening portion 42 was set to various values ​​and experiments were carried out. The results of experimental data 1 are shown in Fig.11 .

[0082] <Example A> In Example A11, a rivet 1a is used, the inclination angle θ1 is 20°, the thickness of the peripheral edge 2b is 1.0 mm, the opening diameter φ1 of the hole 43 is 4.01 mm, the depth is 15 mm, the taper angle θ2 of the opening 42 is 60°, and the height (depth) is 1 mm. In Example A12, the same procedure as in Example A11 was performed except that the taper angle θ2 of the opening 42 was set to 75°. In Example A13, the same procedure as in Example A11 was performed except that the taper angle θ2 of the opening 42 was set to 90°. In Example A14, the same procedure as in Example A11 was performed except that the taper angle θ2 of the opening 42 was set to 105°. In Example A15, the same procedure as in Example A11 was performed except that the taper angle θ2 of the opening 42 was 120°.

[0083] In Example A31, the same procedure as in Example A11 was performed except that the rivet 1b was used, the inclination angle θ1 was 10°, and the thickness of the peripheral edge portion 2b was 0.2 mm. In Example A32, the same procedure as in Example A12 was carried out except that the rivet 1b was used. In Example A33, the same procedure as in Example A13 was carried out except that the rivet 1b was used. In Example A34, the same procedure as in Example A14 was carried out except that the rivet 1b was used. In Example A35, the same procedure as in Example A15 was carried out except that the rivet 1b was used.

[0084] <Comparative Example A> In Comparative Example A21, the same procedure as in Example A11 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A22, the same procedure as in Example A12 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A23, the same procedure as in Example A13 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A24, the same procedure as in Example A14 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A25, the same procedure as in Example A15 was carried out except that the height (depth) of the opening 42 was 2 mm.

[0085] In Comparative Example A41, the same procedure as in Example A31 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A42, the same procedure as in Example A32 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A43, the same procedure as in Example A33 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A44, the same procedure as in Example A34 was carried out except that the height (depth) of the opening 42 was 2 mm. In Comparative Example A45, the same procedure as in Example A35 was carried out except that the height (depth) of the opening 42 was 2 mm.

[0086] In comparative example A51, rivet 1a is used. In comparative example A51, the preliminary hole 41 is that the opening portion 42 is not provided in the first connected member 40, the opening diameter φ1 of the hole portion 43 is 4.1 mm, the taper angle is 5°, and the depth of the hole portion 43 is 16 mm. The hole portion 43 opens directly to the front surface 40a of the first connected member 40. The taper angle θ2 of the opening portion 42 and the height (depth) of the opening portion 42 do not exist. In Comparative Example A52, the same procedure as in Comparative Example A51 was carried out except that the rivet 1b was used.

[0087] <Research> like Fig.11 As shown in the evaluation of each embodiment of the experimental data 1, it can be seen that if the depth (height) of the opening 42 of the preliminary hole 41 is set as H ( Figure 6 ), the thickness of the second connected member 50 at the driving position of the rivets 1a, 1b is taken as T( Figure 6 ) satisfies the relationship of “0.25×T<H<0.75×T”, no cracks are generated in the connected object 60, the generation of holes in the connected object 60 can be suppressed, and sufficient joint strength can be obtained. In addition, it can be seen that the taper angle θ2 ( Figure 6 ) is 70° to 110°, which can suppress the occurrence of holes in the connection object 60.

[0088] Since the thickness of the peripheral portion 2b of the head 2 of the rivet 1a or rivet 1b is approximately in the range of 0.1 to 2.0 mm, the result of the leak test is that the entire connection 60 is leak-free or only has a portion of leaks, so it can be seen that the leak-proofness can be improved to a certain extent. Furthermore, it was found that the evaluation result was good because the inclination angle θ1 of the head 2 of the rivet 1a or the rivet 1b was within the range of 5° to 30°.

[0089] Fig.13 2 is a cross-sectional view of a connection object 60 made by Embodiment A33. Fig.13 As shown, according to this embodiment, it is known that the first connected member 40 and the second connected member 50 are connected without a gap. At this time, it is known that the space of the opening portion 42 surrounded by the opening portion 42 of the first connected member 40 and the back surface 50a of the second connected member 50 is filled with a member generated by the deformation of the second connected member 50. In addition, the first shaft portion 3 and the first connected member 40 are also connected without a gap. In addition, it is known that a part of the first connected member 40 enters the spiral groove 3b of the first shaft portion 3, and the first connected member 40 is inserted while rotating and cutting off.

[0090] [Experimental data 2] In experimental data 2, in each embodiment, except for the helical angle β( Figure 3 ) were set to various numerical values, the experiment was conducted in the same manner as Example A14 of Experimental Data 1. The results of Experimental Data 2 are shown in Fig.12 .

[0091] <Example C> The helical angle β was 53° in Example C11, 105° in Example C12, 180° in Example C13, 210° in Example C14, and 315° in Example C15. In addition, the data of Example A14 and Example C13 are the same.

[0092] <Research> It can be seen from the various embodiments of Experimental Data 2 that when the spiral angle β is approximately in the range of 60° to 360°, it is known that the connector 60 does not produce cracks, the connector 60 has sufficient leakage resistance, and the tensile strength of the connector 60 is sufficiently high and the evaluation result is good. (Explanation of symbols)

[0093] 1a Rivet; 1b Rivet; 2 Head; 2a Central part; 2b peripheral part; 3 first shaft portion; 3a1 front end; 3a2 base end; 3a3 front end; 3b spiral groove (groove); 4 second shaft portion; 5. Protuberance; 21 auxiliary components; 21b inner peripheral surface (holding portion); 30 connected parts; 40 a first connected member; 40a front; 41 Preparation hole; 42 opening; 43 hole; 50 second connected member; 50a back; 50b front; 60 joints; θ1 tilt angle; θ2: cone angle of the opening; θ3: taper angle of the prepared hole; β helix angle.

Claims

1. A riveting method, characterized in that: include: a preparation step, in which the front surface of the first connected member having the preparation hole is overlapped with the back surface of the second connected member; as well as a riveting step, in which a metal rivet placed at a position away from the front face of the second connected member is moved to the position of the prepared hole, so that the rivet is driven into the second connected member and the first connected member in this order and reaches the prepared hole, The prepared hole comprises: a hole portion having an inner wall surface of a substantially conical shape or a substantially truncated cone shape with a tapered front end; and an opening portion, the opening portion expanding in a cone shape from the hole portion toward the front side of the second connected member, The rivet comprises a first shaft portion with a thin front end, The first shaft portion has a front end portion whose diameter decreases toward the front end side. A groove is engraved on the outer peripheral surface of the first shaft portion from the base end side toward the front end side of the first shaft portion, When the depth of the opening is represented by H and the thickness of the second connected member at the position where the rivet is driven is represented by T, 0.25×T<H<0.75×T is satisfied.

2. The riveting method according to claim 1, characterized in that: The cone angle of the opening is 70° to 110°.

3. The riveting method according to claim 1, characterized in that: The opening diameter of the hole portion is larger than the diameter of the base end portion of the first shaft portion.

4. The riveting method according to claim 1, characterized in that: The relationship between the opening diameter φ1 of the hole portion and the diameter φ2 of the base end portion of the first shaft portion is 1.0×φ2<φ1≤1.1×φ2.

5. The riveting method according to claim 1, characterized in that: The taper angle of the hole is 2° to 10°.

6. The riveting method according to claim 1, characterized in that: The rivet further includes a head extending from a base end of the first shaft portion, The first shaft portion hangs down from the head portion, The head portion includes a central portion connected to the first shaft portion and a peripheral portion expanding outward from the central portion. The diameter of the peripheral portion is larger than the diameter of the first shaft portion.

7. The riveting method according to claim 6, characterized in that: The head portion has an umbrella shape in which the peripheral edge portion expands while being inclined toward the first shaft portion.

8. The riveting method according to claim 6, characterized in that: The thickness of the peripheral portion of the head is 0.1 to 2.0 mm.

9. The riveting method according to claim 6, characterized in that: The inclination angle of the head is 5° to 30°.

10. The riveting method according to claim 1, characterized in that: The groove is a spiral groove formed in a spiral shape on the outer surface of the first shaft portion, In the riveting process, the rivet placed at a position away from the front face of the second connected member is moved toward the position of the prepared hole without rotating, so that the rivet is screwed into the prepared hole while rotating in the order of the second connected member and the first connected member.

11. The riveting method according to claim 10, characterized in that: The spiral angle of the spiral groove is 60° to 360°.

12. The riveting method according to claim 6, characterized in that: The rivet further includes a second shaft portion extending from the head on a side of the head opposite to the first shaft portion, In the riveting step, an auxiliary member having a holding portion for holding the second shaft portion is used, and the rivet is moved to the position of the prepared hole for each auxiliary member while the second shaft portion is held by the auxiliary member.

13. The riveting method according to claim 1, characterized in that: The first coupled member and the second coupled member are formed of aluminum or an aluminum alloy.

14. The riveting method according to claim 1, characterized in that: The first connected member is formed of aluminum or an aluminum alloy, and the second connected member is a plate material formed of resin.

15. The riveting method according to claim 1, characterized in that: The first coupled member is a casting material.

16. A connection object, comprising: A first connected member, wherein the first connected member has a prepared hole; a second connected member, wherein the back surface of the second connected member overlaps with the front surface of the first connected member; as well as A rivet, which is made of metal and driven into the second connected member and the first connected member in this order and reaches the prepared hole; The prepared hole comprises: a hole portion having an inner wall surface of a substantially conical shape or a substantially truncated cone shape with a tapered front end; and an opening portion, the opening portion expanding in a cone shape from the hole portion toward the front side of the second connected member, The rivet comprises a first shaft portion with a thin front end, The first shaft portion has a front end portion whose diameter decreases toward the front end side. A groove is engraved on the outer peripheral surface of the first shaft portion from the base end side toward the front end side of the first shaft portion, When the depth of the opening is represented by H and the thickness of the second connected member at the position where the rivet is driven is represented by T, 0.25×T<H<0.75×T is satisfied.

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