CN110842092B

CN110842092B - Method for joining members

Info

Publication number: CN110842092B
Application number: CN201911105193.6A
Authority: CN
Inventors: 前田康裕; 岩谷二郎; 内藤纯也; 胜间秀人
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 2015-02-06
Filing date: 2016-01-04
Publication date: 2021-05-07
Anticipated expiration: 2036-01-04
Also published as: US20190210088A1; EP3254781A1; JP6628858B2; EP3254781B1; JP2016147309A; CN107206464A; JP2019055431A; JP6454233B2; US20180015527A1; CN107206464B; CN110842092A; US20190210089A1; EP3254781A4

Abstract

The invention provides a method for joining members. In the method for joining the members, a steel member (10) having a bottom wall (11) provided with holes (15) and a hollow aluminum pipe (20) are prepared. Then, an aluminum pipe (20) is inserted through a hole (15) of a steel member (10) to pass the aluminum pipe (20) through the bottom wall (11), rubber (30) is inserted into the aluminum pipe (20), and the rubber (30) is compressed in the direction of the axis (L) of the aluminum pipe (20) to expand the rubber (30) from the inside to the outside, whereby at least the portion of the aluminum pipe (20) inserted through the hole (15) is deformed to expand and is caulked to the bottom wall (11). The method for joining members can reduce the load on each member, improve the joining strength, and reduce the cost, thereby joining two members.

Description

Method for joining members

This application is a divisional application of an invention patent application having an international application date of 2016, 04/01/2016, an international application number of PCT/JP2016/050046 (national application number of 201680008666.9), and an invention name of "method for joining members".

Technical Field

The present invention relates to a method of joining members.

Background

In order to reduce the weight of an automobile and improve safety, a thin steel sheet called high-strength steel having high strength is used. The high-strength steel is effective in terms of weight reduction and improvement in safety, but is still heavier than low specific gravity materials such as aluminum. Further, high-strength steel has problems such as a reduction in formability, an increase in forming load, and a reduction in dimensional accuracy due to its high strength. In order to solve these problems, in recent years, a multi-material product has been made by using an extrusion molded product, a cast product, and a press molded product using aluminum having a lower specific gravity than a steel sheet together with a steel member.

This multi-material formation is problematic in the joining of a steel plate member and an aluminum member. In welding techniques represented by spot welding, since a brittle intermetallic compound (IMC) is generated at the interface between a steel plate and an aluminum plate, joining techniques such as electromagnetic forming joining, screw fastening represented by a bolt and a nut, friction stir joining (FSW), a rivet, a self-piercing rivet (SPR), mechanical clinching, and adhesion have been put into practical use.

In the caulking by electromagnetic forming, a solenoid-formed coil is inserted into a tubular member fitted to a target member, and a varying magnetic field generated by an impulse current flowing through the coil induces an induction current in a tube of a conductor. When an electromagnetic force is generated between a magnetic field generated by a primary current of the coil and an induced current flowing in a direction opposite to the circumferential direction of the tube, the tube receives a force directed outward, deforms and expands, and is caulked and joined to the target member. This joining method is suitable for copper and aluminum having good electrical conductivity, and has been partially put into practical use also in joining automobile parts.

Patent document 1 discloses a caulking joining technique by electromagnetic forming for multi-material formation. In patent document 1, a bumper reinforcement made of a metal material having a hollow cross section is deformed and expanded by electromagnetic forming, and is fitted into a hole provided in a bumper stay made of an aluminum alloy, thereby performing joining.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-284039

Disclosure of Invention

Problems to be solved by the invention

As in patent document 1, electromagnetic forming is suitable for caulking and joining a hollow member of copper or aluminum having good electrical conductivity and an object member, and is preferably circular in shape according to the joining mechanism.

However, in joining by electromagnetic forming, the solenoid coil used needs to be smaller than the inner diameter of an aluminum member (aluminum pipe). When joining small-diameter members, the diameter of the coil is reduced, which causes problems in terms of difficulty in manufacturing the coil, performance, and durability. Regarding the difficulty of manufacturing, it is difficult to form the wire into a coil shape, restrictions on the material and the cross-sectional shape of the wire become severe, and the wire cross-section deforms when formed into a coil shape. Further, a new equipment investment requiring a capacitor with a large capacity and a high voltage becomes necessary. Further, it is impossible to join the aluminum member formed with a square cross section, a hole, or a slit.

The invention provides a method for joining members, which can reduce the load relative to each member, improve the joining strength and join two members at low cost.

Means for solving the problems

The present invention provides a method for joining members, wherein a first member having a first portion provided with a first hole portion and a hollow second member are prepared, the second member is inserted into the first hole portion of the first member to pass through the first portion, an elastic body is inserted into the second member, the elastic body is compressed in an axial direction of the second member to expand the elastic body from inside to outside, and at least a portion of the second member inserted into the first hole portion is deformed to expand and is caulked to the first portion.

According to this method, the elastic body is expanded outward to uniformly expand the deformation of the second member, thereby preventing local deformation and reducing the load on each member. This is because the second member can be deformed uniformly by the property that the elastic body compressed in the axial direction expands uniformly from the inside to the outside. Therefore, the fitting accuracy can be improved, and the bonding strength can be improved. Further, the method is simpler than electromagnetic forming and other processing methods. Electromagnetic forming can only be applied to conductive materials, and the cross-sectional shape and size are also limited by the coil used. In contrast, this method is not dependent on the material, nor is there any limitation concerning the cross-sectional shape and size. Further, since the compression force can be applied to the elastic body by a device, an electric device requiring a capacitor having a large capacity is not required. Thus, the two members can be joined at low cost.

In addition, the first hole of the first member may have a shape similar to a cross-sectional shape of a portion of the second member inserted into the first hole.

According to this method, the first member and the second member have similar shapes to each other, and thus the second member can be joined by being deformed to be equally enlarged, and local load can be prevented from being applied to the first member and the second member.

Further, an outer frame mold may be disposed outside the second member, and at least a part of the second member may be formed along the outer frame mold and then joined by caulking.

According to this method, the second member can be deformed into an arbitrary shape by using outer frame molds having various inner surface shapes. The shape of the deformation is appropriately selected from the viewpoint of the performance of the member, and can be formed into a shape according to the application.

Further, an outer frame mold may be disposed outside the second member, and the outer frame mold may be used to partially restrict the expansion and deformation of the second member to perform the caulking joining.

According to this method, the region of the second member that is deformed by expansion can be defined by disposing the outer frame mold, and the region of deformation by expansion can be controlled with high accuracy. The region of enlarged deformation here means a region of enlarged deformation of the second member toward the outside.

Further, when the elastic body is compressed, the second member may be compressed in the axial direction as well.

According to this method, the second member is also compressed in the axial direction, whereby the expanding deformation in the outer direction of the second member can be assisted. That is, the second member can be more reliably deformed to be enlarged and caulked in accordance with the enlarging deformation force from the inside of the second member by the elastic body.

Further, the edge of the first hole may be flanged.

According to this method, the strength of the hole portion and the first portion of the first member can be improved by burring the edge of the hole portion of the first member. Thus, it is possible to prevent deformation of the first member, prevent damage of the second member, and improve the joining strength of both members.

Further, a bead portion may be formed in a convex shape in the axial direction on a surface different from the surface on which the first hole portion is provided, and the bead portion may be caulked and joined together.

According to this method, by performing caulking joining including the crimping portion, both members can be further fixed, and the joining strength can be further improved. In particular, in the case where the second member has a circular cross section, the second member can be prevented from rotating relative to the first member.

Further, the first member may include a second portion having a second hole, and the second member may be caulked and joined to the first hole and the second hole.

According to this method, by performing caulking at two locations, the joint strength can be further improved as compared with the case of performing caulking at one location.

Further, the elastic body may be separated at a joint portion between the first member and the second member.

According to this method, the deformation of the joint portion of the first member can be prevented by separating the elastic body at the joint portion. Specifically, the elastic body is separated so that the elastic body is not arranged in the vicinity of the joint portion, and therefore, the second member does not receive an expanding deformation force from the elastic body in the vicinity of the joint portion and does not expand and deform in the vicinity of the joint portion. Therefore, the first member is not subjected to a force from the second member in the vicinity of the joint portion, and the shape of the joint portion can be maintained.

Further, a flat plate may be interposed between the separated elastic bodies.

According to this method, the flat plate exists at the joint portion, whereby the deformation of the joint portion of the first member can be prevented more reliably. Since the flat plate is not subjected to the compressive force in the axial direction and is not subjected to the expansion deformation, the original shape of the joint portion can be maintained more reliably without applying the expansion deformation force to the joint portion.

Further, the second member may be provided with a partition wall on an inner side thereof, and an outer wall extending in the axial direction, and a plurality of the elastic bodies may be inserted into a space partitioned by the partition wall and then joined by caulking.

According to this method, since the caulking joining is performed using the plurality of elastic bodies, it is possible to prevent concentration of stress due to deformation and reduce a load on the first member and the second member.

Further, the second member may include an end surface inclined with respect to the axis, and both end surfaces of the elastic body in the axial direction may be parallel to the inclined end surface.

According to this method, it is possible to cope with caulking joining of the first member and the second member in a mutually inclined state, which is common in practical use. In particular, by setting both end surfaces of the elastic body to be the same as the joining angle, the elastic body is uniformly deformed to be expanded, and the second member can be uniformly expanded.

Further, the first member may include a standing wall portion parallel to the axis, and deformation of the standing wall portion may be restrained by a fixing jig to perform caulking joining.

According to this method, since the deformation of the first member is restrained by the jig, the deformation of the first member accompanying the pipe expansion deformation of the second member can be suppressed.

Effects of the invention

According to the present invention, the elastic body is expanded from the inside toward the outside to uniformly deform and expand the second member, thereby preventing local deformation and reducing the load on each member. Therefore, the fitting accuracy can be improved, and the bonding strength can be improved. Further, since the method is simple as compared with electromagnetic forming or other processing methods, two members can be joined at low cost.

Drawings

Fig. 1A is a perspective view of a channel-type steel member having a circular hole and an aluminum pipe having a circular section.

Fig. 1B is a perspective view of caulking and joining the steel member of fig. 1A to an aluminum pipe.

Fig. 2A is a sectional view before caulking of the first embodiment of the present invention.

Fig. 2B is a cross-sectional view in the middle of caulking according to the first embodiment of the present invention.

Fig. 2C is a sectional view after caulking of the first embodiment of the present invention.

Fig. 2D is a sectional view of the first embodiment of the present invention when the rubber is pulled out after caulking.

Fig. 3A is a cross-sectional view before caulking in the case where the rubber of the modification of the first embodiment of the present invention is a fluid enclosing member.

Fig. 3B is a cross-sectional view after caulking in the case where the rubber of the modification of the first embodiment of the present invention is a fluid enclosing member.

Fig. 4A is a perspective view of a steel member having a circular hole and an aluminum pipe having a quadrangular cross section.

Fig. 4B is a perspective view of a steel member having a quadrangular hole and an aluminum pipe having a circular cross section.

Fig. 5A is a cross-sectional view of an example of a joint of steel members subjected to burring.

Fig. 5B is a cross-sectional view of another example of the joint portion of the steel member subjected to the burring.

Fig. 5C is a cross-sectional view of another example of the joint portion of the steel member subjected to the burring.

Fig. 6A is a perspective view of a joint portion of a steel member having a round hole subjected to burring.

Fig. 6B is a perspective view of a joint portion of a steel member having a quadrangular hole subjected to burring.

Fig. 7A is a sectional view before caulking using an outer frame mold according to a second embodiment of the present invention.

Fig. 7B is a sectional view after caulking using an outer frame mold according to the second embodiment of the present invention.

Fig. 8A is a perspective view of an aluminum pipe shaped into a circular pipe shape.

Fig. 8B is a perspective view of an aluminum pipe formed into a regular hexagonal tubular shape.

Fig. 8C is a perspective view of an aluminum pipe shaped into a cross-pipe shape.

Fig. 9A is a cross-sectional view of the third embodiment of the present invention before caulking by disposing rubber only in the vicinity of the joint portion.

Fig. 9B is a cross-sectional view of the third embodiment of the present invention after caulking with rubber disposed only in the vicinity of the joint.

Fig. 10A is a sectional view before the aluminum pipe is partially expanded by using the outer frame die to perform caulking in a modification of the third embodiment of the present invention.

Fig. 10B is a sectional view after the aluminum pipe is partially expanded by using the outer frame die and caulked according to a modification of the third embodiment of the present invention.

Fig. 11A is a cross-sectional view of a press piece having a truncated cone shape according to a fourth embodiment of the present invention before caulking.

Fig. 11B is a cross-sectional view after caulking by a pressing piece having a truncated cone shape according to a fourth embodiment of the present invention.

Fig. 12A is a sectional view of a fifth embodiment of the invention before caulking by compressing an aluminum pipe in the axial direction.

Fig. 12B is a sectional view after caulking by axially compressing the aluminum pipe according to the fifth embodiment of the invention.

Fig. 13A is a cross-sectional view of a tablet with an outer frame according to a modification of the fifth embodiment of the present invention before caulking.

Fig. 13B is a cross-sectional view of a tablet with an outer frame according to a modification of the fifth embodiment of the present invention after caulking.

Fig. 14A is a perspective view of a steel member having a circular hole and an aluminum pipe having a circular cross section in the case of caulking at two places according to a sixth embodiment of the present invention.

Fig. 14B is a perspective view of a steel member having a quadrangular hole and an aluminum pipe having a quadrangular cross section in a case where caulking is performed at two places according to a sixth embodiment of the present invention.

Fig. 15A is a perspective view of a cap channel-type steel member having a circular hole and an aluminum pipe having a circular cross section in the case of caulking at two places in a modification of the sixth embodiment of the present invention.

Fig. 15B is a perspective view of a cap channel-shaped steel member having a quadrangular hole and an aluminum pipe having a quadrangular cross section in a case where two portions are caulked in a modification of the sixth embodiment of the present invention.

Fig. 16 is a cross-sectional view of the middle of caulking of fig. 15A and 15B.

Fig. 17A is a sectional view after caulking of fig. 16.

Fig. 17B is a sectional view of fig. 16 after being partially expanded and caulked.

Fig. 18A is a cross-sectional view after caulking the steel member and the aluminum pipe at the surface where the crimping portion is formed in the modification of the seventh embodiment of the present invention.

Fig. 18B is a cross-sectional view taken along line XVIII-XVIII of fig. 18A.

Fig. 19 is a sectional view after caulking using separated rubber in the eighth embodiment of the present invention.

Fig. 20A is a sectional view after caulking with a flat plate interposed between separated rubbers according to a modification of the eighth embodiment of the present invention.

Fig. 20B is a cross-sectional view of a modified example of the eighth embodiment of the present invention after caulking the joint portions using rubbers having different hardness.

Fig. 21A is a perspective view of a resin cylinder member and an aluminum pipe according to a ninth embodiment of the present invention before caulking.

Fig. 21B is a perspective view after caulking of the resin cylinder member and the aluminum pipe of fig. 21A.

Fig. 22A is a sectional view before caulking of the resin cylinder member and the aluminum pipe of fig. 21A.

Fig. 22B is a sectional view after caulking of the resin cylinder member and the aluminum pipe of fig. 21A.

Fig. 23 is a perspective view of a steel bumper beam and an aluminum stay according to a tenth embodiment of the present invention.

Fig. 24A is a sectional view of a projection jig according to a tenth embodiment of the present invention.

Fig. 24B is a sectional view of an aluminum stay in a state where a steel bumper beam and a protrusion jig are inserted according to a tenth embodiment of the present invention.

Fig. 25A is a sectional view before caulking of the tenth embodiment of the present invention.

Fig. 25B is a sectional view after caulking of the tenth embodiment of the present invention.

Fig. 26A is a cross-sectional view of the tenth embodiment of the present invention after removing the jig for projections after caulking.

Fig. 26B is a sectional view taken along line XXVI-XXVI of fig. 26A.

Figure 27A is a perspective view of an aluminum pipe according to an eleventh embodiment of the present invention.

Fig. 27B is a cross-sectional view before caulking of the lines XXVII-XXVII of fig. 27A.

Fig. 27C is a sectional view after caulking of the lines XXVII-XXVII of fig. 27A.

FIG. 27D is a plan view of an aluminum pipe and rubber in an eleventh embodiment of the invention.

Fig. 27E is a plan view of the aluminum pipe of the eleventh embodiment of the invention together with rubber of other shapes.

Fig. 27F is a plan view of the aluminum pipe, rubber, and L-shaped angle member according to the eleventh embodiment of the present invention.

Fig. 28A is a sectional view before caulking of the twelfth embodiment of the present invention.

Fig. 28B is a sectional view after caulking of the twelfth embodiment of the present invention.

Fig. 29A is a front and rear plan view of caulking according to a thirteenth embodiment of the present invention.

Fig. 29B is a front and rear plan view of caulking according to the thirteenth embodiment of the present invention.

Fig. 29C is a front view before caulking of the thirteenth embodiment of the present invention.

Fig. 29D is a front view of the thirteenth embodiment of the present invention after caulking without using a fixing jig.

Fig. 29E is a front view after caulking using a fixing jig according to the thirteenth embodiment of the present invention.

Description of reference numerals:

10 Steel component (first component)

11 bottom wall (first part)

12. 13 side wall

12a, 13a edge pressing part

14 Upper wall (second part)

15 hole part (first hole part)

15a shoulder

15b corner part

15c straight edge part

17 hole part (second hole part)

18 standing wall part

20 aluminum pipe (second component)

21 end of the tube

22 expanding the deformation zone

23 partition wall

24 outer wall

25 end face

30 rubber (elastomer)

30a high hardness part

30b, 30c end face

31 flat plate

32 fluid enclosing member

40 stamping device

41 outer frame die

42 bearing seat

42a convex part

42b flange part

42c inclined surface

43 tabletting

43a convex part

43b raised edge portion

43c cut part

43d pressing surface

44 outer frame die

44a diameter expanding part

45 outer frame

46L-shaped angle piece

47 fixing clamp

50 resin cylinder part

110 steel bumper beam (first component)

111 separator

112 hole (hole part)

113 opening part

114 a top plate;

120 aluminum stay (second component)

130 rubber (elastomer)

131 flat plate

132 counter bore

140 round bar

141 convex edge

150 protruding anchor clamps of using

151 pressing jig

152 lower mold.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, terms indicating directions and positions (for example, "upper side" and "lower side") are sometimes used, but these terms are made for easy understanding of the present invention, and the technical scope of the present invention is not limited by the meaning of these terms. The following description is merely exemplary of one embodiment of the present invention, and is not intended to limit the present invention, its applications, or its uses.

In the embodiments described below, materials of the respective members are exemplified, but the materials of the respective members in all the embodiments are not limited to those specifically exemplified, and the present invention can be applied to any material.

(first embodiment)

A joining method of caulking and joining the steel member (first member) 10 and the aluminum pipe (second member) 20 will be described with reference to fig. 1A to 2D.

As shown in fig. 1A, the steel member 10 is made of high-strength steel and has a channel-like shape. The steel member 10 includes a bottom wall (first portion) 11, two

side walls

12 and 13 extending vertically upward from the bottom wall 11, and an upper wall 14 extending horizontally outward from the two

side walls

12 and 13, respectively. The bottom wall 11 is provided with a hole portion (first hole portion) 15 through which the aluminum pipe 20 can be inserted. The aluminum pipe 20 is made of an aluminum alloy, is hollow, has a circular cross section, and extends in the direction of the axis L. The axis L passes through the center of the aluminum pipe 20 and the center of the hole portion 15 of the steel member 10.

As shown in fig. 1B, the aluminum pipe 20 and the steel member 10 are crushed by expanding and deforming the aluminum pipe 20 from the inside to the outside, and the upper end 21 in the drawing is caulked and joined to the hole portion 15 of the steel member 10. The shape and size of the hole 15 of the steel member 10 are similar to the cross-sectional shape of the aluminum pipe 20, and are preferably as small as possible within a range in which the aluminum pipe 20 can be inserted.

Caulking joining of the steel member 10 to the aluminum pipe 20 is performed in the following order.

As shown in fig. 2A to 2D, rubber (elastomer) 30 is used for caulking joining of the steel member 10 and the aluminum pipe 20.

First, as shown in fig. 2A, the aluminum pipe 20 is inserted into the hole 15 of the steel member 10, and the rubber 30 is inserted into the aluminum pipe 20 and set in the press machine 40. The aluminum pipe 20 may be inserted into the hole 15 with the rubber 30 inserted therein. The press device 40 includes a pressing piece 43 and a receiving base 42. The pressing piece 43 has a flat lower surface, and presses the steel member 10 or the rubber 30 with the lower surface. The receiving seat 42 has a flat upper surface, and the steel member 10 or the rubber 30 is placed on the upper surface. The rubber 30 has a cylindrical shape having a diameter capable of being inserted into the aluminum pipe 20, and a rubber having a longer overall length than the aluminum pipe 20 is used. Thus, in the set state, the rubber 30 partially protrudes from the upper end of the aluminum pipe 20. Therefore, when the pressing device 40 starts pressing and the receiving seat 42 and the pressing piece 43 are relatively close to each other, the rubber 30 is pressed first. However, the rubber 30 does not necessarily have to protrude from the upper end of the aluminum pipe 20, and may be coplanar with the upper end of the aluminum pipe 20 or housed inside the aluminum pipe 20.

Next, as shown in fig. 2B, an external force for compressing the rubber 30 is applied in the direction of the axis L by the pressing device 40. The rubber 30 expands in the radial direction as the dimension in the direction of the axis L decreases. This elastically deforms (expands) the rubber 30 from the axis L toward the outside, and the aluminum pipe 20 is deformed to expand. Then, as shown in fig. 2C, the aluminum pipe 20 is further expanded and deformed by further compression by the pressing device 40, and the upper end 21 of the aluminum pipe 20 in the drawing is bent and crushed toward the steel member 10, and is caulked and joined to the steel member 10.

After the caulking joint, as shown in fig. 2D, the rubber 30 from which the compression force of the pressing device 40 is removed is restored to its original shape by its own elastic force, and can be easily removed from the aluminum pipe 20.

According to this method, the rubber 30 is expanded outward to uniformly expand and deform the aluminum pipe 20, thereby preventing local deformation and reducing the load on the

members

10 and 20. This is because the aluminum pipe 20 can be deformed uniformly by utilizing the property that the rubber 30 compressed in the direction of the axis L expands uniformly from the inside toward the outside. Therefore, the fitting accuracy can be improved, and the joining strength can be improved. Further, the method is simpler than electromagnetic forming or other processing methods.

Electromagnetic forming can only be applied to conductive materials, and the cross-sectional shape and size are also limited by the coil used. In contrast, this method is not dependent on the material, nor is there any limitation concerning the cross-sectional shape and size. Further, since the compression can be performed by a device that applies a compressive force to the rubber 30, an electric device that requires a capacitor having a large capacity, such as electromagnetic molding, is not necessary.

As described above, according to this method, two members can be joined, and the multi-material manufacturing can be easily performed at low cost. Therefore, as described above, this method can be applied to members of various materials in addition to two members made of high-strength steel and aluminum alloy. The same applies to the following embodiments.

As a material of the rubber 30 inserted into the aluminum pipe 20, for example, any one of urethane rubber, chloroprene rubber, CNR rubber (chloroprene rubber + nitrile rubber), and silicone rubber is preferably used. Further, the hardness of these rubbers 30 is preferably 30 or more in shore a.

The member inserted into the aluminum pipe 20 is not limited to the rubber 30. For example, as shown in fig. 3A and 3B, a fluid-filled member 32 in which a gas or a liquid is filled may be used instead of the rubber 30. In addition, any other member may be used as long as it can expand outward by a compressive force to expand and deform the aluminum pipe 20. Preferably, the member deforms uniformly like the rubber 30 when expanding outward in accordance with the compression force.

As shown in fig. 4A and 4B, the shape and size of the hole 15 provided in the bottom wall 11 of the steel member 10 may not be similar to the cross-sectional shape of the aluminum pipe 20 to be fitted. Specifically, as shown in fig. 4A, the steel member 10 having the circular hole 15 can be joined by caulking to the aluminum pipe 20 having a square cross section, and as shown in fig. 4B, the steel member 10 having the square hole 15 can be joined by caulking to the aluminum pipe 20 having a circular cross section.

Further, as shown in fig. 5A to 5C, in order to prevent deformation of the steel member 10, reduce damage to the aluminum pipe 20, and improve the caulking strength, the hole portion 15 may be subjected to burring (flanging up). As the shape of the burring, various cross-sectional shapes such as those shown in fig. 5A to 5C are considered. The radius of the shoulder 15A is increased in fig. 5A. The shoulder 15a is chamfered in fig. 5B. In fig. 5C, roll processing is employed. According to these, even when the strength of the steel member 10 is high, the work crack of the steel member 10 can be effectively prevented.

The direction of the burring may be either upward or downward in the drawing. Preferably, the portion bent and raised by the burring is formed downward in the drawing as indicated by a two-dot chain line in fig. 2A so as not to appear on the surface of the steel member 10.

As shown in fig. 6A and 6B, the shape of the hole 15 to be subjected to the burring may be a circular shape (see fig. 6A), a square shape (see fig. 6B), or the like. In particular, when the hole 15 is polygonal, as shown in fig. 6B, the corner 15B is notched, and only the straight portion 15c is bent and raised, thereby preventing the corner 15B from being broken.

(second embodiment)

In the joining method of the present embodiment shown in fig. 7A and 7B, the configuration except for the portion related to the outer frame mold 41 is the same as that of the first embodiment of fig. 2A to 2D. Therefore, the same components as those in the configuration shown in fig. 2A to 2D are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 7A, in the present embodiment, the steel member 10 and the aluminum pipe 20 are caulked and joined using an outer frame mold 41. The outer frame mold 41 is cylindrical concentric with the aluminum pipe 20. The outer frame mold 41 is disposed between the receiving base 42 and the steel member 10 and outside the aluminum pipe 20. In a state where the aluminum pipe 20 is set in the press device 40, a gap is provided between the aluminum pipe 20 and the outer frame mold 41. In this state, as shown in fig. 7B, the pressing by the pressing piece 43 allows the shape of the inner surface of the outer frame mold 41 to be followed when the aluminum pipe 20 is subjected to expansion deformation.

According to this method, as shown in fig. 8A to 8C, the inner surface of the outer frame mold 41 may be formed into a cylindrical shape (see fig. 8A), or may be formed into various polygonal shapes such as a hexagonal shape (see fig. 8B) and a cross shape (see fig. 8C). These shapes can be appropriately selected from the viewpoint of component performance and the like. For example, in the case where the aluminum pipe 20 is a bumper stay which is one of automobile parts, when minute irregularities are provided to the inner surface of the outer frame mold 41, the minute irregularities are transferred to the aluminum pipe 20, and the absorption performance of collision energy at the time of collision can be improved.

(third embodiment)

In the joining method of the present embodiment shown in fig. 9A to 10B, the structure other than the portion relating to the enlarged deformation region 22 of the aluminum pipe 20 is the same as that of the first embodiment of fig. 2A to 2D. Therefore, the same components as those in the configuration shown in fig. 2A to 2D are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 9A, in the present embodiment, the length of the rubber 30 inserted into the aluminum pipe 20 is shortened, and the rubber 30 is disposed only in the vicinity of the joint of the aluminum pipe 20. Further, the receiving seat 42 has a columnar projection 42a extending upward, and the projection 42a is inserted into the aluminum pipe 20 and supports the rubber 30. That is, the lower end of the rubber 30 abuts against the upper end of the projection 42a, and the upper end of the rubber 30 abuts against the lower end of the pressing piece.

According to this method, no outward expanding deformation force acts on the portion where the rubber 30 is not disposed. Therefore, as shown in fig. 9B, the enlargement deformation region 22 of the aluminum pipe 20 is restricted, and only the vicinity of the joint portion of the aluminum pipe 20 is enlarged and deformed, so that the aluminum pipe can be caulked and joined to the steel member 10. Whether to deform the aluminum pipe 20 substantially entirely as in the first and second embodiments or to locally deform the aluminum pipe 20 as in the present embodiment is appropriately selected depending on the relationship with the component performance or the like.

As shown in fig. 10A and 10B, a cylindrical outer frame mold 44 for restricting expansion deformation may be disposed around the aluminum pipe 20. The outer frame mold 44 has an enlarged diameter portion 44a formed with a large inner diameter near the joint portion at the upper end, so that only the vicinity of the joint portion is enlarged and deformed. The inner diameter of the portion other than the enlarged diameter portion 44a is substantially equal to the outer diameter of the aluminum pipe 20. Thus, when the outer frame mold 44 is used, the enlarged deformation region 22 can be controlled with high accuracy so that only the vicinity of the joint portion of the aluminum pipe 20 is enlarged and deformed.

(fourth embodiment)

In the joining method of the present embodiment shown in fig. 11A and 11B, the configuration except for the portion relating to the shape of the pressing piece 43 is the same as that of the third embodiment shown in fig. 10A and 10B. Therefore, the same components as those in the configuration shown in fig. 10A and 10B are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 11A, the pressing piece 43 provided in the pressing device 40 of the present embodiment has a truncated cone shape tapered downward at the tip, and has a convex portion 43a and a convex edge portion 43 b. In some cases, a high forming force is required to expand and deform the end 21 of the aluminum pipe 20 protruding toward the upper side of the steel member 10 in the drawing, and therefore, sufficient caulking cannot be performed only by deformation of the rubber 30, or the rubber 30 is largely deformed, which may cause a problem in durability. In this case, the method of the present embodiment is effective.

As shown in fig. 11B, at the end of the forming, the end 21 on the upper side in the drawing of the aluminum pipe 20 protruding toward the upper side of the steel member 10 is directly pushed and expanded outward by the convex portion 43a of the presser piece 43 without passing through the rubber 30, and is further bent toward the steel member 10. This enables more firm caulking and joining. Further, since no excessive load is applied to the rubber 30, the durability of the rubber 30 is improved.

(fifth embodiment)

In the joining method of the present embodiment shown in fig. 12A and 12B, the configuration except for the portions relating to the shapes of the pressing piece 43 and the receiving seat 42 is the same as that of the first embodiment of fig. 2A to 2D. Therefore, the same components as those in the configuration shown in fig. 2A to 2D are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 12A, in the present embodiment, the receptacle 42 includes a columnar convex portion 42A extending upward, and a brim portion 42b provided around the convex portion 42A. The pressing piece 43 includes a cylindrical protrusion 43a extending downward, and a flange portion 43b provided around the protrusion 43 a. The

projections

42a, 43a are inserted into the aluminum pipe 20, respectively.

As shown in fig. 12B, when the pressing is performed, the beads 42B, 43B abut against the respective ends of the aluminum pipe 20. Thereby, the aluminum pipe 20 is given a compressive force in the direction of the axis L by the

beads

42b, 43 b.

According to this method, the aluminum pipe 20 is also compressed in the direction of the axis L, whereby the expanding deformation in the outside direction of the aluminum pipe 20 can be assisted. That is, the aluminum pipe 20 can be further reliably deformed by expansion and caulking in accordance with the expansion deformation force of the rubber 30 for expanding and deforming the aluminum pipe 20 from the inside.

As shown in fig. 13A and 13B, it is also effective to dispose the outer frame 45 outside the portion of the aluminum pipe 20 which is not subjected to extensive deformation (the end portion 21 in the present embodiment). The outer frame 45 is cylindrical and is disposed around the end 21 of the aluminum pipe 20. By disposing the outer frame 45, the deformation of the end 21 of the aluminum pipe 20 is regulated and formed into a shape corresponding to the use purpose.

(sixth embodiment)

In the joining method of the present embodiment shown in fig. 14A to 17B, the configuration except for the number of the joining portions is the same as that of the first embodiment of fig. 2A to 2D. Therefore, the same components as those in the configuration shown in fig. 2A to 2D are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 14A, in the present embodiment, the steel member 10 and the aluminum pipe 20 are caulked at two locations. The steel member 10 includes a bottom wall 11 having a closed cross section, an upper wall (second portion) 14 disposed parallel to the bottom wall 11, and two

side walls

12 and 13 connecting the upper wall and the lower wall. The bottom wall 11 is provided with a hole 15 (first hole). The upper wall 14 is provided with a hole 17 (second hole). As shown in fig. 14B, the aluminum pipe 20 is caulked to the

hole portions

15, 17 at the two locations.

Fig. 16 shows a cross-sectional view at the time of caulking. In the upper hole 17 in the drawing in caulking joining to the two

holes

15 and 17, the end 21 of the aluminum pipe 20 is bent and crushed toward the steel member 10 by the pressing piece 43, and the aluminum pipe 20 is further enlarged and deformed to perform caulking joining, as in the first embodiment. In the figure, the lower hole portion 15 is caulked by expanding and deforming only the aluminum pipe 20.

By performing caulking at two locations as in the present embodiment, the joining strength can be further improved as compared with the case of caulking at one location. In particular, the method of caulking using the rubber 30 is effective because it can easily cope with caulking at a plurality of places as in the case of caulking at one place using a facility.

The shape of the steel member 10 or the aluminum pipe 20 at the time of joining at two places is not limited thereto. For example, the steel member 10 may be a cap channel type as shown in fig. 15A and 15B, or may have another shape.

Further, as shown in fig. 17A, the entire aluminum pipe 20 can be freely deformed to be enlarged at the time of caulking. As shown in fig. 17B, the outer frame mold 41 described with reference to fig. 7A and 7B may be used to perform caulking joining by enlarging and deforming only the vicinity of the joint portion of the aluminum pipe 20.

(seventh embodiment)

In the joining method of the present embodiment shown in fig. 18A and 18B, the configuration except for the portions related to the joining site and the crimping

portions

12a and 13a is the same as that of the sixth embodiment of fig. 16. Therefore, the same components as those in the configuration shown in fig. 16 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 18A and 18B, in the present embodiment, crimping

portions

12a and 13a are provided on both

side walls

12 and 13 of the steel member 10, respectively. The crimping

portions

12a, 13a are inwardly convex and extend in the direction of the axis L. The aluminum pipe 20 is caulked to the hole portion 15 of the bottom wall 11 and all of the crimping

portions

12a, 13a of the two

side walls

12, 13.

As shown in fig. 18B, the joint strength can be further improved by performing the caulking joint including the crimping

portions

12a and 13a of the

side walls

12 and 13. Further, since the caulking joining is performed including the crimping

portions

12a, 13a, the rotation of the aluminum pipe 20 with respect to the component member 10 can be restricted. In this way, the

beads

12a, 13a are also effective in preventing rotation of the aluminum pipe 20. Instead, in order to prevent the rotation of the aluminum pipe 20, it is also effective to provide the edge of the hole portion 15 with a notched shape or a shape other than a circular shape.

(eighth embodiment)

In the joining method of the present embodiment shown in fig. 19, the configuration except for the portion relating to the case where the rubber 30 is separated is the same as that of the seventh embodiment of fig. 18A. Therefore, the same components as those in the configuration shown in fig. 18A are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 19, in the present embodiment, the rubber 30 is separated in the vicinity of the hole 15. According to this method, the rubber 30 is separated in the hole 15, that is, the joint, and thus deformation of the hole 15 and the bottom wall 11 of the steel member 10 can be prevented. Specifically, since the rubber 30 is separated, the hole 15 is not subjected to an expanding deformation force, and the original shapes of the hole 15 and the bottom wall 11 can be maintained.

Further, as shown in fig. 20A, a plate-like flat plate 31 is preferably inserted between the rubbers 30 inserted toward the aluminum pipe 20 and separated at the joint portion. The material of the flat plate 31 may be any of metal, resin, and the like as long as it has a strength not to be deformed by the compressive force received from the rubber 30, and the thickness thereof is preferably 15mm or less.

According to this method, the flat plate 31 is present at the joint portion, whereby deformation of the hole portion 15 and the bottom wall 11 of the steel member 10 can be more reliably prevented. Since the flat plate 31 is not deformed to be enlarged, the hole 15 is not subjected to an enlarging deformation force, and the original shapes of the hole 15 and the bottom wall 11 can be maintained.

In fig. 20A, the rubber 30 is separated and the flat plate 31 is disposed therebetween, but instead, as shown in fig. 20B, a rubber 30 having a locally different material may be used. In fig. 20B, the rubber is not separated but integrated, but has a high hardness portion 30a in the vicinity of the joint. That is, in the rubber 30, only the vicinity of the joint portion is formed to have high hardness. Therefore, the high-hardness portion 30a functions similarly to the flat plate 31, and the original shapes of the hole 15 and the bottom wall 11 can be maintained.

(ninth embodiment)

In the joining method of the present embodiment shown in fig. 21A to 22B, the configuration except for the portion related to replacement of the steel member 10 with the cylindrical resin cylindrical member 50 is the same as that of the fifth embodiment of fig. 9A and 9B. Therefore, the same components as those in the configuration shown in fig. 9A and 9B are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 21A and 21B, in the present embodiment, a cylindrical resin tubular member 50 having a flange at the upper end is caulked and joined to the aluminum pipe 20. As in the case of the resin tubular member 50, the target member may not be plate-shaped, and may not be made of metal. As described above, the rubber 30 deforms in the outside direction when a compressive force in the direction of the axis L is applied, thereby expanding and deforming the aluminum pipe 20. Therefore, unlike electromagnetic molding, the shape is not limited to a conductive material, and the shape is not limited to a plate shape even if the resin material can be used.

Fig. 22A and 22B are sectional views of the resin cylinder member and the aluminum pipe of fig. 21A taken in front and rear directions of caulking. As shown in fig. 22A and 22B, the aluminum pipe 20 is deformed and caulked at both ends of the cylindrical resin cylindrical member 50.

(tenth embodiment)

An example of implementing the present invention will be described with respect to a bumper, which is one of automobile parts.

As shown in fig. 23, a steel bumper beam (first member) 110 having a closed cross section with a spacer 111 at the center is caulked to a cylindrical aluminum stay (second member) 120. The steel bumper beam 110 has

openings

113 and 113 at both sides, and the

openings

113 and 113 are divided by a partition 111. Fig. 23 shows a state in which a top plate 114 (see fig. 26A) of the steel bumper beam 110 is removed for the sake of explanation. As shown in fig. 24A, a raising jig 150 including a round bar-shaped rubber 130, a steel plate-shaped flat plate 131, and a steel thin round bar 140 is used in the implementation. A through hole 112 into which the thin round bar 140 can be inserted is provided at the center of the rubber (elastic body) 130 and the plate-like flat plate 131. A flange 141 for preventing the rubber 130 from falling is provided at one end of the round bar 140. The rubber 130 is divided into two parts, and a counter bore 132 capable of being locked by a flange 141 of the round bar 140 is provided in one of the two parts. Then, a plate-like flat plate 131 is placed on the rubber 130 with the counterbore 132 facing downward, the other rubber 130 is placed on the flat plate 131, and the round bar 140 is inserted from below. The flat plate 131 has a circular shape with an outer diameter of 83.5mm and a thickness of 10mm, and a circular shape with an outer diameter of 83.5mm, a length of 50mm, and a hardness of 90 Shore A are used as the rubber 130.

Fig. 24B shows a state in which aluminum stay 120 is inserted through hole (hole portion) 112 (see fig. 23) provided in steel bumper beam 110, and projection jig 150 described above is inserted into aluminum stay 120. As shown in fig. 23, a 1470MPa grade cold-rolled steel plate having a plate thickness of 1.4mm is roll-formed into a closed cross-sectional shape having a spacer 111 at the center, and a circular hole 112 having an outer diameter of 90.2mm is bored in a joint portion with an aluminum stay 120. At this time, the central separator 111 is also partially removed. Aluminum stay 120 was a circular tube made of a6063 aluminum alloy and having a plate thickness of 3mm, an outer diameter of 90mm, and a length of 150 mm.

Next, the caulking process shown in fig. 25A and 25B will be described. Fig. 25A shows a state in which the steel bumper beam 110, the aluminum stay 120, and the protrusion jig 150 are provided on the lower die 152, and the pressing jig 151 is disposed above. In this state, the pressing device is set in the pressing device 40 (see fig. 2A to 2D), and the slider provided with the pressing jig 151 is lowered to apply a compression force to the rubber 130. At this time, the aluminum pipe 20 shown in fig. 9A and 9B is not pressed in the direction of the axis L.

Fig. 25B shows a condition where the slider is at the bottom dead center. The pressing jig 151 compresses the rubber 130 to expand and deform the rubber in the horizontal direction, and the aluminum stay 120 is subjected to expansion molding. Since the plate-like flat plate 131 is inserted, unnecessary deformation is suppressed without applying an excessive force to the joining surface of the steel bumper beam 110, and caulking joining with high fitting accuracy can be completed.

Fig. 26A and 26B show the steel bumper beam 110 and the aluminum stay 120 after caulking. Fig. 26A is a sectional view of the steel bumper beam 110 and the aluminum stay 120 in a state of being caulked, and fig. 26B is a sectional view taken along line XXVI-XXVI. This embodiment is characterized in that the joint strength is high by caulking the center spacer 111 in addition to caulking provided in the hole 112 of the steel bumper beam 110 based on the deformation of the aluminum stay 120 due to the rubber 130 as shown in fig. 26B.

(eleventh embodiment)

In the joining method of the present embodiment shown in fig. 27A to 27F, the structure except for the portion relating to the insertion of the plurality of rubbers 30 into the aluminum pipe 20 having the partition wall 23 inside the aluminum pipe 20 is the same as that of the fifth embodiment of fig. 9A and 9B. Therefore, the same portions as those of the structure shown in fig. 9A to 9B are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 27A, the aluminum pipe 20 of the present embodiment has an outer wall 24 extending in the direction of the axis L and having a quadrangular cross section, and a partition wall 23 provided inside the outer wall 24. The space inside the aluminum pipe 20 is divided into four parts by partition walls 23 which are cross-shaped in plan view. By providing the partition walls 23 in this manner, the strength of the aluminum pipe 20 can be improved. The cross-sectional shape is not limited to a quadrangle, and may be any shape.

As shown in fig. 27B and 27C, the pressing piece 43 of the present embodiment is provided with a notch 43C conforming to the shape of the partition wall 23. By providing the notch portion 43c, caulking can be completed without interfering with the aluminum pipe 20 even when the rubber 30 is pressed.

In this way, since the caulking joining is performed using the plurality of rubbers 30 (4 in the present embodiment), concentration of stress associated with the deformation can be prevented, and the load on the steel member 10 and the aluminum pipe 20 can be reduced.

The shape of the rubber 30 of the present embodiment is not particularly limited. For example, as shown in fig. 27D, the corners of the inserted 4 rubbers 30 may be R-chamfered to reduce the load applied to the corners of the aluminum pipe 20, thereby preventing breakage and damage. As shown in fig. 27E, C chamfering may be performed similarly to R chamfering. As shown in fig. 27F, the 4 pieces of rubber 30 inserted have a cylindrical shape, but an L-shaped angle 46 made of steel may be disposed along the partition wall 23 inside the aluminum pipe 20. This reduces the load applied to the partition wall 23 and suppresses deformation.

(twelfth embodiment)

In the joining method of the present embodiment shown in fig. 28A and 28B, the structure except for the portion relating to joining of the component member 10 and the aluminum pipe 20 in a mutually inclined state is the same as that of the fifth embodiment of fig. 9A and 9B. Therefore, the same portions as those of the structure shown in fig. 9A to 9B are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 28A and 28B, the aluminum pipe 20 of the present embodiment has an end surface 25 inclined with respect to the axis L. The component 10 is bent and placed on the inclined surface 42 c. The aluminum pipe 20 is placed with the inclined end face 25 in contact with the inclined face 42c, and is caulked to the component member 10. Thus, the constituent member 10 and the aluminum pipe 20 are caulked in a mutually inclined state. Both end faces 30b, 30c of the rubber 30 of the present embodiment are formed and arranged in parallel with the inclined end face 25 of the aluminum pipe 20. The pressing surface 43d of the pressing piece 43 is also formed parallel to the end surfaces 30b and 30c of the rubber 30.

With this structure, it is possible to cope with caulking joining of the structural member 10 and the aluminum pipe 20 in a mutually inclined state, which is common in practical use. Specifically, by setting both

end surfaces

30b, 30c of the rubber 30 to be the same as the joining angle, the rubber 30 is uniformly deformed to be enlarged, and the aluminum pipe 20 can be uniformly expanded.

(thirteenth embodiment)

In the joining method of the present embodiment shown in fig. 29A to 29D, the configuration except for the portion relating to joining in a state where deformation of the constituent member 10 is restrained by the fixing jig 47 is the same as that of the fifth embodiment of fig. 9A and 9B. Therefore, the same portions as those of the structure shown in fig. 9A to 9B are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 29A and 29B, the component 10 of the present embodiment includes a bottom wall 11 and an upright wall portion 18 extending from the bottom wall 11 in the direction of the axis L. The cross-sectional shape of the aluminum pipe 20 before caulking may be circular (see the broken line in fig. 29A) or quadrangular (see the broken line in fig. 29B), and the shape is not particularly limited. A fixing jig 47 for suppressing deformation is provided on the outer side of the component 10. The fixing jig 47 is disposed along the standing wall portion 18, and is fixed from the arrow direction of the figure so as not to move outward. In the present embodiment, the plate-shaped fixing jig 47 is used, but the shape of the fixing jig 47 is not limited thereto, and may be any shape capable of suppressing deformation.

As shown in fig. 29C to 29E, when the fixing jig 47 is not provided, the component 10 may be deformed to warp when caulking is performed (see fig. 29D). However, by restricting the deformation of the component 10 by the fixing jig 47, the deformation such as the warp of the component 10 caused by the expansion deformation of the aluminum pipe 20 can be suppressed (see fig. 29E).

Claims

1. A method of joining members, wherein,

a first member having a first portion provided with a first hole and a hollow second member are prepared,

inserting the second member into the first hole of the first member to penetrate the first portion,

an elastic body is inserted into the interior of the second member,

compressing the elastic body in the axial direction of the second member and expanding the elastic body from the inside to the outside, thereby expanding and deforming at least a portion of the second member inserted into the first hole portion and caulking-joining the portion to the first portion,

the second member has an end surface inclined with respect to the axis,

both end surfaces of the elastic body in the axial direction are parallel to the inclined end surfaces.

2. A method of joining members, wherein,

a first member having a bottom wall provided with a first hole and a hollow second member are prepared,

the second member is inserted into the first hole of the first member and penetrates the bottom wall,

an elastic body is inserted into the interior of the second member,

compressing the elastic body in the axial direction of the second member and expanding the elastic body from the inside to the outside, thereby expanding and deforming at least a portion of the second member inserted into the first hole and caulking-joining the bottom wall,

the first member includes upright wall portions extending from the bottom wall in parallel with the axis and formed on both sides of the bottom wall,

the deformation of the standing wall portion is restrained by a fixing jig to perform caulking joining.

3. The joining method of members according to claim 1 or 2,

the first hole of the first member has a shape similar to a cross-sectional shape of a portion of the second member inserted into the first hole.

4. The joining method of members according to claim 1 or 2,

an outer frame mold is disposed outside the second member, and at least a part of the second member is formed along the outer frame mold and is caulked and joined,

in a state where the second member is provided in the pressing device, a gap between the second member and the outer frame mold is larger than a gap between the second member and the first hole of the first member, and the second member can be brought into close contact with an inner surface shape of the outer frame mold when being deformed in an enlarged manner.

5. The joining method of members according to claim 1 or 2,

an outer frame mold is disposed outside the second member, and expansion and deformation of the second member are locally restricted by the outer frame mold to perform caulking joining.

6. The joining method of members according to claim 1 or 2,

when the elastic body is compressed, the second member is also compressed in the axial direction.

7. The joining method of members according to claim 1 or 2,

and flanging the edge of the first hole part.

8. The joining method of members according to claim 1 or 2,

the first member has a second portion having a second hole portion, and is caulked and joined to the second member at the first hole portion and the second hole portion.

9. The joining method of members according to claim 1 or 2,

the elastic body is separated at a joint portion of the first member and the second member.

10. The joining method of members according to claim 9,

a flat plate is inserted between the separated elastic bodies.

11. The joining method of members according to claim 1 or 2,

the second member is provided with a partition wall on the inner side and an outer wall extending in the axial direction,

the elastic bodies are inserted into the spaces partitioned by the partition walls and are caulked together.