WO2018025667A1

WO2018025667A1 - Member machining method and member joining method

Info

Publication number: WO2018025667A1
Application number: PCT/JP2017/026474
Authority: WO
Inventors: 康裕前田; 徹橋村; 渡辺　憲一
Original assignee: 株式会社神戸製鋼所
Priority date: 2016-08-02
Filing date: 2017-07-21
Publication date: 2018-02-08
Also published as: JP2018020338A

Abstract

The member joining method according to the present invention comprises: preparing a steel component 10 having a hole 11, an aluminum pipe 20 having a strength different from that of the steel component 10 and having a hollow shape extending in an axis L direction, and a rubber 30 having an elongation of at least 300% and a Shore A of at least 40 degrees; inserting the aluminum pipe 20 in the hole 11 of the steel component 10; inserting the rubber 30 into the aluminum pipe 20; enlarging and deforming the aluminum pipe 20 by compressing the rubber 30 in the axis L direction and by expanding the rubber 30 radially outward with respect to the axis L; and joining the aluminum pipe 20 and the steel component 10 together.

Description

Member processing method and member joining method

The present disclosure relates to a member processing method and a member joining method.

A low specific gravity and high strength metal called high tension steel is used to reduce the weight and safety of automobiles. High-tension steel is effective in reducing weight and improving safety, but is heavier than low specific gravity materials such as aluminum. Further, when high tension steel is used, problems such as a decrease in formability, an increase in forming load, and a decrease in dimensional accuracy occur due to high strength. In order to solve these problems, in recent years, multi-materials have been used in which extruded products, cast products, and press-formed products using aluminum having a specific gravity lower than steel are used together with steel parts. .

The problem with multi-materials is the joining of dissimilar metals such as steel parts and aluminum parts. For example, Patent Literature 1 discloses a member joining method that enables joining of dissimilar metals in multi-materials by using an elastic body. In the member joining method of Patent Document 1, a tubular body (first member) is inserted into a through hole of a wall surface body (second member), an elastic body is inserted inside the tubular body, and the elastic body is pressurized. The tubular body is bulged, and the tubular body and the wall surface are in pressure contact.

JP 51-133170 A

However, in the joining method disclosed in Patent Document 1, the characteristics of the elastic body used are not considered in detail. That is, a preferable range is not mentioned about characteristics, such as elongation and hardness of an elastic body.

The embodiment of the present invention has been made under such circumstances, and the object thereof is to reduce the residual strain and cracking of the elastic body and to make it easy to cut in the member processing method using the elastic body. The body is used to enlarge and deform the first member.

The member processing method according to the first aspect of the present invention provides a first member that extends in the axial direction and has a hollow shape, and an elastic body having an elongation of 300% or more and a Shore A of 40 degrees or more. The elastic body is inserted into the inside, and the elastic body is compressed in the axial direction and expanded outward in the radial direction of the axial line, thereby expanding and deforming the first member.

In the method for joining members according to the second aspect of the present invention, a hole is provided, the second member having a strength different from that of the first member is further prepared, and the first member is provided in the hole of the second member. Including inserting a member, joining the first member and the second member by enlarging and deforming the first member using the member processing method.

According to these methods, the elastic body is expanded outward in the radial direction of the axis to uniformly expand and deform the first member, thereby preventing local deformation and reducing the load on each member. This is because the first member can be uniformly deformed by utilizing the property that the elastic body compressed in the axial direction expands uniformly toward the outside in the radial direction of the axial line. Therefore, the fitting accuracy between the second member and the first member is improved, and the bonding strength can be improved. Further, it is simpler than a joining method in which electromagnetic forming or other processing is performed. Here, the strength of the first member and the second member indicates general properties related to deformation and fracture of the material such as yield strength, tensile strength, ductility, rigidity, or bending strength.

The inventor of the present application has examined the characteristics of the elastic body used in these methods in detail, and as a result, discovered the following four problems. First, if the elastic body is strongly compressed, permanent deformation may remain in the elastic body and the cross-sectional area of the elastic body may increase, making it difficult to insert and remove the elastic body from the first member. Second, the frictional force generated on the contact surface between the elastic body and the first member may cause the elastic body surface to be locally subjected to shear deformation, and the elastic body may be cracked. Thirdly, when pressurization is performed using a press device such as an indenter, the cross-sectional area of the elastic body becomes large, so that the press device may bite into the elastic body and cracks may occur in the elastic body. Fourth, it is difficult to cut a soft elastic body.

In response to these four problems, this method uses an elastic body having an elongation of 300% or more and a Shore A of 40 degrees or more. Here, the measuring method prescribed in JIS-K-6251 is used as the measuring method of elongation. As a hardness measurement method, Shore A defined in JIS-K-6253 is used. In addition to these properties, there are many other properties such as tensile strength and specific gravity. However, the present inventor has found that the above four problems can be solved by specifying only the elongation and hardness (Shore A), and an elastic body suitable for the above method can be selected. For the first problem, if an elastic body having a large elongation is used, the residual strain can be suppressed. Therefore, an elastic body having an elongation of 300% or more that does not affect the insertion and extraction of the elastic body is used. is doing. For the second and third problems, if an elastic body having a high hardness is used, cracking can be suppressed. Therefore, an elastic body having a hardness of 40 degrees Shore A or higher, which is a hardness required for joining, is used. For the fourth problem, the use of a high-hardness elastic body can suppress the difficulty of cutting, so use an elastic body of Shore A 40 ° C. or higher, which is a hardness that does not make cutting difficult. Yes.

The shape of the hole of the second member and the cross-sectional shape of the portion inserted through the hole of the first member may be similar.

According to this method, since the second member and the first member are similar to each other, the first member can be uniformly enlarged and deformed, and a local load is applied to the second member and the first member. It can be prevented from occurring. Here, the similar shape indicates a case seen from the axial direction.

When compressing the elastic body, the first member may also be compressed in the axial direction.

According to this method, the first member can also be compressed in the axial direction to assist the expansion deformation in the outer direction of the first member. That is, the first member can be expanded and deformed more reliably in the outer direction in combination with the expansion deformation force from the inside of the first member by the elastic body.

The edge of the hole of the second member may be burring processed.

According to this method, by burring the edge of the hole of the second member, the strength of the hole of the second member can be improved and the deformation of the second member can be prevented. Moreover, since the joining area of a 2nd member and a 1st member increases by burring process, joining strength can be improved.

A mold may be disposed outside the first member, and at least a part of the first member may be molded and joined along the mold.

</ RTI> According to this method, the first member can be deformed into an arbitrary shape by using molds having various inner shapes. The shape to be deformed can be appropriately selected from the viewpoint of component performance, etc., and can be made into a shape according to the application.

An outer frame mold may be disposed outside the first member, and the outer frame mold may partially restrict the enlarged deformation of the first member and join them.

According to this method, by using the outer frame mold, it is possible to define a region where the first member is expanded and deformed, and to control the expanded deformation region with high accuracy. Here, the enlarged deformation region refers to a region where the first member is enlarged and deformed outward.

According to the present invention, in the member processing method and joining method using an elastic body, the first member can be enlarged and deformed by using an elastic body that suppresses residual strain and cracking of the elastic body and is easy to cut. Further, it can be joined to the second member.

The perspective view before joining of steel components and aluminum pipes which apply the joining method of the member concerning a 1st embodiment of the present invention. The perspective view after joining of steel parts and the aluminum pipe which applied the joining method of the member concerning a 1st embodiment of the present invention. Sectional drawing before joining of the joining method of the member which concerns on 1st Embodiment. Sectional drawing before joining of the joining method of the member which concerns on 1st Embodiment. Sectional drawing in the process of joining of the joining method of the member which concerns on 1st Embodiment. Sectional drawing after joining of the joining method of the member which concerns on 1st Embodiment. The perspective view which shows an example of the rubber | gum before and behind compression. The fragmentary sectional view showing an example of rubber under compression. The fragmentary sectional view showing an example of rubber under compression. A graph showing the relationship between the elongation and hardness of rubber. The graph which shows the relationship between the tensile strength and hardness of rubber. Sectional drawing before joining of the 1st modification of 1st Embodiment. Sectional drawing after joining of the 1st modification of 1st Embodiment. Sectional drawing before joining of the 2nd modification of 1st Embodiment. Sectional drawing after joining of the 2nd modification of 1st Embodiment. The perspective view before joining of the hat-shaped steel components and aluminum pipe which the joining method of the member which concerns on 2nd Embodiment applies. The perspective view after joining of the hat-shaped steel components and the aluminum pipe to which the joining method of the member concerning a 2nd embodiment was applied. Sectional drawing before joining of the joining method of the member which concerns on 2nd Embodiment. Sectional drawing in the process of joining of the joining method of the member which concerns on 2nd Embodiment. Sectional drawing in the process of joining of the joining method of the member which concerns on 2nd Embodiment. Sectional drawing after joining of the joining method of the member which concerns on 2nd Embodiment. Sectional drawing before joining of the joining method of the member which concerns on 3rd Embodiment. Sectional drawing in the process of joining of the joining method of the member which concerns on 3rd Embodiment. The perspective view of the aluminum pipe shape | molded by the circular tube shape. The perspective view of the aluminum pipe shape | molded by the regular hexagonal tube. The perspective view of the aluminum pipe shape | molded by the cross pipe. Sectional drawing before joining of the joining method of the member which concerns on 4th Embodiment. Sectional drawing in the process of joining of the joining method of the member which concerns on 4th Embodiment. Sectional drawing before joining of the modification of 4th Embodiment. Sectional drawing after joining of the modification of 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
With reference to FIGS. 1A to 2D, a method of joining members that join the steel part (second member) 10 and the aluminum pipe (first member) 20 will be described. In the following, as an example of joining dissimilar metals, an example in which the steel part 10 and the aluminum pipe 20 are joined is shown, but the material of the member to be joined is not particularly limited. It may be other than aluminum. Here, the strength indicates general properties related to deformation and fracture of a material such as yield strength, tensile strength, ductility, rigidity, or bending strength. The same applies to the following second to fourth embodiments.

As shown in FIG. 1A, the steel part 10 is a flat plate made of high-tension steel. The steel part 10 is provided with a hole 11 through which the aluminum pipe 20 can be inserted. The aluminum pipe 20 is made of an aluminum alloy, has a hollow tubular shape with 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 11 of the steel part 10.

As shown in FIG. 1B, when the aluminum pipe 20 expands radially outward, the aluminum pipe 20 is pressed into the hole 11 of the steel part 10. The shape and dimensions of the hole 11 of the steel part 10 are preferably 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. Here, the similar shape indicates a case seen from the direction of the axis L.

As shown in FIGS. 2A to 2D, rubber (elastic body) 30 is used for joining the steel part 10 and the aluminum pipe 20.

First, as shown in FIG. 2A, the aluminum pipe 20 is inserted into the hole 11 of the steel part 10 and the rubber 30 is inserted into the aluminum pipe 20 to constitute the assembly 1 before joining. At this time, the aluminum pipe 20 may be inserted through the hole 11 of the steel part 10 with the rubber 30 inserted therein. Then, as shown in FIG. 2B, the assembly 1 in that state is set in the press device 40.

The pressing device 40 includes an indenter 41 and a seat 42. The indenter 41 includes a columnar convex portion 41a extending downward, and a collar portion 41b provided around the convex portion 41a. The lower surface 41c of the convex portion 41a of the indenter 41 is a flat surface. The receiving seat 42 includes a columnar convex portion 42a extending upward and a flange portion 42b provided around the convex portion 42a. The upper surface 42c of the convex portion 42a of the receiving seat 42 is a flat surface, and the rubber 30 is placed on the upper surface 42c of the convex portion 42a of the receiving seat 42.

The rubber 30 has a cylindrical shape with a diameter that can be inserted into the aluminum pipe 20. The length of the rubber 30 may be a length that can deform the aluminum pipe 20 in the vicinity of the joint. The rubber 30 to be used has characteristics of elongation of 300% or more and Shore A of 40 degrees or more. The measuring method defined in JIS-K-6251 is used as the measuring method of elongation. As a hardness measurement method, Shore A defined in JIS-K-6253 is used. The characteristics of the rubber 30 will be described later.

Next, as shown in FIG. 2C, the rubber 30 is sandwiched between the lower surface 41c of the convex portion 41a of the indenter 41 and the upper surface 42c of the convex portion 42a of the seat 42, and is compressed in the direction of the axis L. As the size of the rubber 30 in the direction of the axis L decreases, the size in the radial direction increases. In this manner, the rubber 30 is elastically deformed so as to expand from the axis L toward the radially outer side, and the aluminum pipe 20 is expanded and deformed so as to be in pressure contact with the steel part 10.

After joining, as shown in FIG. 2D, the rubber 30 from which the compressive force of the press device 40 has been removed is restored to its original shape by its own elastic force. Therefore, the rubber 30 can be easily removed from the aluminum pipe 20.

As a result of examining the characteristics of the rubber 30 in detail with respect to such a member joining method, the present inventor has found the following four problems. First, when the rubber 30 is strongly compressed, permanent deformation remains in the rubber 30 and the cross-sectional area of the rubber 30 increases, making it difficult to insert and remove the rubber 30 from the aluminum pipe 20 (see FIG. 3A). Secondly, the frictional force generated at the contact surface between the rubber 30 and the aluminum pipe 20 causes the surface of the rubber 30 to undergo local shear deformation, and the rubber 30 is cracked (see FIG. 3B). Third, when the press device 40 such as the indenter 41 is used for pressurization, the cross-sectional area of the rubber 30 increases, so that the press device 40 bites into the rubber 30 and the rubber 30 is cracked (see FIG. 3C). ). Fourth, it is difficult to cut the soft rubber 30.

In response to these four problems, this method uses a rubber 30 having an elongation of 300% or more and a Shore A of 40 degrees or more. The properties of rubber 30 include tensile strength and many other properties. However, the present inventor has found that the above four problems can be solved by defining only the elongation and hardness (Shore A). For the first problem, since the residual strain can be suppressed by using the rubber 30 having a large elongation, the rubber 30 having an elongation of 300% or more that does not affect the insertion and extraction of the rubber 30 is used. is doing. For the second and third problems, the use of the high-hardness rubber 30 can suppress cracking, so the rubber 30 having a hardness of 40 degrees Shore A or higher, which is a hardness required for joining, is used. For the fourth problem, the use of the rubber 30 having a high hardness can suppress the difficulty of cutting, so the rubber 30 having a hardness of 40 degrees Shore A or higher, which is a hardness that does not make the cutting difficult. Yes.

In order to verify the properties of the rubber 30 suitable for the above method, the inventors of the present application have considered the properties of various types of rubber 30. Table 1 below summarizes the rubber 30 to be considered and its characteristics.

The verification was performed on the assumption that the pipe expansion of the aluminum pipe 20 made of a 6000 series aluminum alloy was performed on various types of rubber 30 shown in Table 1. As conditions, it is assumed that the rubber 30 has a diameter of 55 mm and a length of 50 mm, the aluminum pipe 20 has a diameter of 60 mm and a thickness of 2 mm, and compresses the rubber 30 by 20% (10 mm).

The hardness, elongation, and tensile strength are considered as the properties of the rubber 30. As a hardness measurement method, Shore A defined in JIS-K-6253 is used. The measuring method defined in JIS-K-6251 is used as the measuring method of elongation. The measuring method used for JIS-K-6251 is used as the measuring method of tensile strength.

As the evaluation items of the rubber 30, the persistence of permanent strain, the presence or absence of cracks on the upper and lower surfaces of the rubber 30, and the machinability were considered. The persistence of permanent strain is indicated by the symbol x when the outer diameter of the rubber 30 after compression is measured and assumed to be larger than the inner diameter (56 mm) of the aluminum pipe 20. When the outer diameter of the rubber 30 becomes larger than this, the insertion and removal of the rubber 30 becomes difficult. The presence or absence of cracks on the upper and lower surfaces of the rubber 30 is indicated by the symbol x when it is assumed that the cracks can be visually confirmed. The machinability is indicated by the symbol x when the maximum roughness Ry when the side surface of the columnar rubber 30 is turned is 0.5 or more. When the rubber 30 is soft, the surface roughness is deteriorated by escaping when the cutting tool is pressed or by the cutting tool biting into the rubber 30. When the surface roughness is deteriorated, the frictional resistance between the rubber 30 and the aluminum pipe 20 is increased, and uniform tube expansion deformation is difficult. In addition, the volume of the rubber 30 cannot be maintained constant, and the amount of pipe expansion cannot be defined with respect to the amount of compression.

Considering the relationship between the properties of the rubber 30 and the evaluation items from Table 1 above, the preferable properties of the rubber 30 are an elongation of 300% or more and a hardness (Shore A) of 40 degrees or more. Specifically, the elongation of the permanent strain may be 300% or more, and the cracking property and the machinability may be hardness (Shore A) of 40 degrees or more. That is, the above first to fourth problems can be solved by defining only the elongation and the hardness, regardless of the tensile strength.

4A and 4B are graphs showing the results of Table 1 above. As shown in FIG. 4A, there is a correlation between elongation (elongation at break) and hardness (Shore A). That is, as the hardness increases, the elongation tends to decrease. Accordingly, elongation and hardness are not independent parameters, and it is necessary to select a rubber 30 made of a specific material that simultaneously satisfies the above-described conditions for elongation and hardness. As shown in FIG. 4B, there is no correlation between tensile strength and hardness (Shore A).

Moreover, in this embodiment, since the indenter 41 and the receiving seat 42 have the

flange portions

41b and 42b, respectively, when the rubber 30 is compressed, the aluminum pipe 20 may also be compressed in the axis L direction by the

flange portions

41b and 42b. .

The aluminum pipe 20 can also be compressed in the direction of the axis L to assist the expansion deformation in the outer direction of the aluminum pipe 20. That is, in combination with the expansion deformation force from the inside of the aluminum pipe 20 by the rubber 30, the aluminum pipe 20 can be more reliably expanded and deformed outwardly and joined.

Further, as shown in FIGS. 5A and 5B, as a first modification of the present embodiment,

outer frames

41d and 42d are arranged outside the portion of the aluminum pipe 20 that is not enlarged and deformed (the end in this modification). May be. The

outer frames

41d and 42d are cylindrical and are arranged around both ends of the aluminum pipe 20. By disposing the

outer frames

41d and 42d, deformation of both end portions of the aluminum pipe 20 can be restricted, only the joint portion can be deformed, and the shape according to the intended use can be obtained.

As shown in FIGS. 6A and 6B, burring may be performed on the edge of the hole 11 of the steel part 10 as a second modification of the present embodiment. By burring the edge of the hole 11 of the steel part 10, the strength of the hole 11 of the steel part 10 can be improved and the deformation of the steel part 10 can be prevented. Moreover, since the joining area of the steel part 10 and the aluminum pipe 20 is increased by burring, the joining strength can be improved.

The processing method for enlarging and deforming the aluminum pipe 20 used in the member joining method of the present embodiment may be used independently of the joining. That is, the aluminum pipe 20 can be enlarged and deformed by the rubber 30 regardless of the joining with the steel part 10 to obtain a desired shape.

(Second Embodiment)
7A to 8D show a method for joining members according to the second embodiment of the present invention. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 7A, the steel part 10 has a channel shape made of high tension steel. The steel part 10 includes a bottom wall 12, two side walls 13 that extend vertically upward from the bottom wall 12, and an upper wall 14 that extends outward from each of the two side walls 13 in the horizontal direction. The bottom wall 12 is provided with a hole 11 through which the aluminum pipe 20 can be inserted.

As shown in FIG. 7B, the aluminum pipe 20 is expanded and deformed radially outward, and is joined to the hole 11 of the steel part 10 by crushing the upper end portion in the drawing. In this way, the

members

10 and 20 may be joined not only by deforming and expanding the aluminum pipe 20 but also by crushing the ends.

This joining method will be described in detail. As shown in FIG. 8A, the aluminum pipe 20 is inserted into the hole 11 of the steel part 10, the rubber 30 is inserted into the aluminum pipe 20, and set in the press device 40. . However, the aluminum pipe 20 may be inserted through the hole 11 with the rubber 30 inserted therein. The press device 40 includes an indenter 41 and a receiving seat 42. The indenter 41 has a flat lower surface 41c. The seat 42 has a flat upper surface 42c, and the steel part 10 and the rubber 30 are placed on the upper surface 42c. The rubber 30 has a cylindrical shape with a diameter that can be inserted into the aluminum pipe 20, and has a longer overall length than the aluminum pipe 20. Therefore, in the set state, the rubber 30 partially protrudes from the upper end of the aluminum pipe 20. For this reason, when the press device 40 starts pressing and the seat 42 and the indenter 41 relatively approach 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 accommodated in or flush with the upper end of the aluminum pipe 20.

Next, as shown in FIG. 8B, the rubber 30 is compressed in the direction of the axis L by the press device 40. As the size of the rubber 30 in the direction of the axis L decreases, the size in the radial direction increases. Thus, the rubber 30 is expanded outward from the axis L, and the aluminum pipe 20 is expanded and deformed. Then, as shown in FIG. 8C, the aluminum pipe 20 is further expanded and deformed by further compression by the pressing device 40, and at the same time, the upper end in the drawing of the aluminum pipe 20 is bent toward the steel part 10 and pushed. Crushing and joining with the steel part 10.

After the joining, as shown in FIG. 8, the rubber 30 from which the compressive force of the press device 40 has been removed is restored to its original shape by its own elastic force. Therefore, the rubber 30 can be easily removed from the aluminum pipe 20.

As in this embodiment, the shape of the steel part 10 may be a hat shape or other shapes, and is not particularly limited. Moreover, the aspect of joining including the aspect of the press apparatus 40 is not specifically limited, It can variously, such as pipe expansion joining or the joining which crushed the edge part.

(Third embodiment)
9A and 9B show a method for joining members according to the third embodiment of the present invention. In the present embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 9A, in this embodiment, the steel part 10 and the aluminum pipe 20 are joined using the mold 43. The mold frame 43 has a cylindrical shape concentric with the aluminum pipe 20. The mold 43 is disposed between the seat 42 and the steel part 10 and outside the aluminum pipe 20. When set in the pressing device 40, a gap is provided between the aluminum pipe 20 and the mold frame 43. In this state, as shown in FIG. 9B, by pressing with the indenter 41, the inner shape of the mold 43 can be adjusted when the aluminum pipe 20 is expanded and deformed.

According to this method, as shown in FIGS. 10A to 10C, the shape of the inner surface of the mold 43 is not limited to a cylindrical shape (see FIG. 10A) but a hexagonal shape (see FIG. 10B) or a cross shape (see FIG. 10C). Various polygonal shapes can be used. These shapes may be appropriately selected from the viewpoint of component performance. In addition to these, for example, in the case where the aluminum pipe 20 is a bumper stay which is one of the automobile parts, if the minute unevenness is given to the inner surface of the mold 43, the minute uneven shape is transferred to the aluminum pipe 20. As a result, it is possible to improve the performance of absorbing collision energy at the time of collision.

(Fourth embodiment)
11A and 11B show a method for joining members according to the fourth embodiment of the present invention. In the present embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals and description thereof is omitted.

As shown in FIGS. 11A and 11B, in this embodiment, a cylindrical outer frame mold 44 that partially restricts expansion deformation is disposed around the aluminum pipe 20. The outer frame mold 44 has an enlarged diameter portion 44a having a large inner diameter in the vicinity of the joint portion at the upper end so that only the vicinity of the joint portion is enlarged and deformed. The inner diameter other than the enlarged diameter portion 44a is approximately equal to the outer diameter of the aluminum pipe 20.

When the outer frame mold 44 is used, the enlarged deformation region can be controlled with high accuracy so that only the vicinity of the joint portion of the aluminum pipe 20 is enlarged and deformed. Here, the enlarged deformation region refers to a region in which the aluminum pipe 20 is enlarged and deformed outward.

As shown in FIG. 12A, the indenter 41 provided in the press device 40 may have a truncated cone shape that is tapered downward in the drawing. A high forming force may be required for the enlarged deformation of the end of the aluminum pipe 20 protruding upward in the drawing of the steel part 10. In such a case, the shape of the indenter 41 that can directly deform the aluminum pipe 20 by the indenter 41 is effective.

As shown in FIG. 12B, at the end of molding, the upper end portion of the aluminum pipe 20 protruding upward from the steel part 10 is directly pushed outward by the indenter 41 without the rubber 30 interposed therebetween. It is bent towards the steel part 10. Thereby, it can join more firmly. Further, since an excessive load does not act on the rubber 30, the durability of the rubber 30 is improved.

As described above, specific embodiments of the present invention and modifications thereof have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, what combined suitably the content of each embodiment is good also as one Embodiment of this invention.

1 Assembly 10 Steel parts (second member)
11 hole 12 bottom wall 13 side wall 14 upper wall
20 Aluminum pipe (first member)
30 Rubber (elastic body)
40 Pressing device 41 Indenter 41a Protruding part

41b Collar part

41c Lower surface

41d Outer frame 42 Receiving seat

42a Convex part

42b Collar part

42c Upper surface

42d Outer frame 43 Mold frame 44 Outer frame mold 44a Expanding part

Claims

A first member extending in the axial direction and having a hollow shape, and an elastic body having an elongation of 300% or more and a Shore A of 40 degrees or more are prepared.
Inserting the elastic body into the first member;
A member processing method, comprising: compressing the elastic body in the axial direction and expanding the elastic body toward a radially outer side of the axis, thereby expanding and deforming the first member.
A hole is provided, and a second member having a different strength from the first member is further prepared,
Inserting the first member into the hole of the second member;
A member joining method comprising: enlarging and deforming the first member using the member processing method according to claim 1 to join the first member and the second member.
The method for joining members according to claim 2, wherein the shape of the hole portion of the second member and the cross-sectional shape of the portion inserted through the hole portion of the first member are similar.
The member joining method according to claim 2 or 3, wherein when compressing the elastic body, the first member is also compressed in the axial direction.
The member joining method according to claim 2 or 3, wherein an edge of the hole portion of the second member is burring processed.
The member joining method according to claim 2 or 3, wherein a mold is disposed outside the first member, and at least a part of the first member is molded and joined along the mold.
4. The member according to claim 2, wherein an outer frame mold is disposed outside the first member, and the expansion deformation of the first member is partially limited by the outer frame mold to be joined. 5. Joining method.