JP5388642B2 - Dissimilar joint structure manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a dissimilar joint structure in which joint parts are integrally formed when a vehicle part is molded.

As a dissimilar material joint structure, in order to join one side part and the other side part formed of dissimilar metals, a joint part made of the same material as that of the one side part is integrally formed at the time of molding the other side part. Casting objects are known.
This kind of dissimilar joint structure improves the joint strength between parts formed of different metals. As such a dissimilar joint structure, one in which a steel joint part is integrally formed at the time of forming an aluminum die cast part is known (for example, see Patent Document 1).

  As shown in FIG. 13, the dissimilar joint structure 200 of Patent Document 1 (in which the reference is changed) has a bonding force between a light metal die-cast part 201 such as aluminum and a steel joint part 203. A plurality of anchor holes 211 are formed on the steel joint component 203 side so as to be secured without depending on the joining force generated at the interface between the component 201 and the joint component 203, and when the die cast is formed, the plurality of anchor holes 211 are formed. This is a mechanical fastening structure in which the molten metal on the die-cast component 201 side wraps around and an anchor portion 212 is formed on the die-cast component 201 side.

  Further, FIG. 14 shows a dissimilar joint structure 220 as a specific example similar to the dissimilar joint structure 200 of Patent Document 1. The dissimilar joint structure 220 is formed by integrally forming a steel joint part 223 on the damper housing body 221 side, which is a die-cast part of light metal such as aluminum, at the time of die-casting. In the dissimilar joint structure 220, the anchor hole 231 is formed in the joint component 223, and the anchor portion 232 is formed in the main body 221 of the damper housing.

  15 (a) and 15 (b) illustrate a joint portion having the anchor holes 211 and 231 and the anchor portions 212 and 232 of the dissimilar joint structure 200 and 220 (see FIGS. 13 and 14) cut out into a strip shape and simulated. A structural example shown in the figure will be described as a dissimilar joint structure 100.

  In addition, (a) is a side view of the dissimilar joint structure 100, (b) is a bb sectional view of (a). 15A and 15B, a light metal die-cast part such as aluminum will be described as “base material (die-cast part) 101”, and a steel joint part will be described as “iron member 103”.

As shown in FIGS. 15A and 15B, a plurality of anchor holes 111 are formed in the iron member 103 in advance, and the base material 101 has anchor portions 112 respectively formed in the plurality of anchor holes 111 during molding. Is formed.
The plurality of anchor holes 111 are simple holes (piercings).

  When breaking loads P1 and P1 are applied to the upper end and the lower end of the base material 101 and the iron member 103, the base material 101 and the iron member 103 have “base material break A1 in the base material 101”, “anchor”. "Shear fracture A2 at the part 112", "Main body part fracture A3 at the main body part 104 of the iron member 103", "End part fracture A4 of the iron member 103", "Inter-anchor hole fracture A5 of the anchor hole 111" can be considered. . Said fracture | rupture A1-A5 shows a fracture | rupture form (a fracture | rupture position is also included).

  Generally, the strength variation of the base material 101 which is a die-cast part of light metal such as aluminum is larger than the strength variation of the iron member 103. Accordingly, the diameter of the anchor portion 112 is set to be large in consideration of the safety factor of the anchor portion 112.

However, when the diameter of the anchor portion 112 is increased, the tensile strength of the iron member 103 is lowered. The order of the tensile strength at which the material breaks is “base material fracture A1 at base material 101”> “main body part fracture A3 at main body part 104 of iron member 103”, “shear fracture A2 at anchor part 112”> It is considered that “main body part breakage A3 at the main body part 104 of the iron member 103”. Further, it is considered that “main body part breakage A3 at the main body part 104 of the iron member 103”> “end part breakage A4 of the iron member 103”> “anchor hole breakage A5 of the anchor hole 111”. That is, “anchor hole break A5 of the anchor hole 111” is considered to be the worst.
Accordingly, even when the diameter of the anchor portion 112 is set to be large, it is preferable that the decrease in the breaking load of “anchor breakage A5 of the anchor hole 111” can be prevented.

JP 2006-312192 A

  In the present invention, even when the diameter of the anchor portion is set large, it is possible to prevent a decrease in the breaking load of the anchor hole breakage between the anchor holes, and comprehensively, light metal die-cast parts such as aluminum and steel ( It is an object of the present invention to provide a dissimilar joint structure capable of ensuring the balance of strength between the steel member and the joint component.

  The invention of the manufacturing method of the dissimilar joint structure according to claim 4 is a manufacturing method of the dissimilar joint structure in which the iron member is cast with a light alloy, and when the anchor hole is provided in the iron member and the anchor hole is formed in the burring hole. Further, the diameter of the burring hole is set to be small until the tensile strength of the light alloy injection portion of the anchor hole becomes substantially the same as that of the simple hole.

The present invention has the following effects.
In the invention which concerns on Claim 1, the dissimilar-material joint structure which casts an iron member with a light alloy is manufactured. An anchor hole is provided in the iron member, and this anchor hole is formed as a burring hole. At this time, the diameter of the burring hole is set to be small until the tensile strength of the light alloy injection portion into the anchor hole becomes substantially the same tensile strength as in the case of the simple hole. The distance between the anchor holes that is expected to be the weakest on the iron member side can be set long. Thereby, the tensile strength around the anchor hole can be increased. As a result, the strength of the dissimilar joint structure can be further increased as a whole.

It is a perspective view of the damper housing which employ | adopted the dissimilar material joint structure which concerns on this invention. It is a perspective view of the iron member of the dissimilar joint structure shown by FIG. It is a front view of the iron member of the dissimilar-material joint structure shown by FIG. It is a front view of the iron member of another Example of the dissimilar material joint structure shown by FIG. It is the front view cut out in the strip shape of the dissimilar-material joint structure shown by FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is a comparison examination figure of the dissimilar joint structure shown in FIG. It is action | operation explanatory drawing of the dissimilar joint structure shown by FIG. FIG. 2 is an explanatory diagram for comparison operation of the dissimilar joint structure shown in FIG. 1. FIG. 2 is a comparative study showing an increase in tensile strength in the dissimilar joint structure shown in FIG. 1. FIG. 2 is a diagram for explaining a comparative action when the burring diameter is reduced in the dissimilar joint structure shown in FIG. 1. FIG. 2 is a comparative study showing an increase in tensile strength when the burring diameter is reduced in the dissimilar joint structure shown in FIG. 1. It is a front view of the dissimilar joint structure of patent document 1. It is sectional drawing which shows the conventional different material joint structure. It is explanatory drawing which represented typically patent document 1 or the conventional different material joint structure.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

  As shown in FIG. 1, the damper housing 16 has an upper left portion connected to the upper member 13 and the lower member 14, and a lower right portion connected to the front side frame 12. The vehicle body frame 10 includes an upper member 13, a lower member 14, a damper housing 16, and a front side frame 12 as main components at the front of the vehicle body. Further, the body frame 10 is made of a steel material such as steel, with the exception of the housing main body (die-cast part) 21 of the damper housing 16. Specifically, the front side frame 12, the upper member 13, and the lower member 14 are all closed cross-sectional bodies having a substantially rectangular cross section when viewed from the front. For example, the front side frame 12 is a press-formed product made of a steel plate. The upper member 13 and the lower member 14 are formed of square pipes (steel pipes).

  The upper member 13 and the lower member 14 are steel body skeleton members that form a part of the vehicle body 10.

  The front side frame 12 extends in the front-rear direction on both left and right sides of the front portion of the vehicle body. The front side frame 12 has an extension (not shown) extending rearward from the rear end. This extension portion is connected to a floor frame (not shown). The front side frame 12 has a structure in which the outer member 17 and the inner member 18 are joined, and a flange portion 19 to which the damper housing 16 is joined is formed at an upper portion.

  The upper member 13 is located on the upper side of the front side frame 12 and on the outer side in the vehicle width direction, and extends in the front-rear direction on both the left and right sides of the front portion of the vehicle body. The rear end of the upper member 13 is joined to the front end of a front pillar (not shown) by welding.

  The lower member 14 is located directly below the upper member 13 and extends in the front-rear direction on both the left and right sides of the front portion of the vehicle body. The front end portion of the lower member 14 is integrally connected to the lower surface of the upper member 13 at the position of the damper housing 16 by welding. The rear end portion of the lower member 14 is joined to the front lower end portion of a front pillar (not shown) by welding.

  The damper housing 16 houses a damper of a front suspension (not shown) and fixes the upper end of the damper. The damper housing 16 is coupled to the front side frame 12 via a lower coupling portion (iron member) 23 in which an upper end portion is coupled to the upper member 13 and the left lower member 14 and a lower end portion is integrally formed. Yes. The damper housing 16 shows the left damper housing, and the right damper housing (not shown) has the same configuration as the left damper housing 16.

  The damper housing 16 is a cast product (die-cast component or the like) mainly composed of a light alloy such as aluminum. For example, an aluminum alloy (including aluminum) is employed as the light alloy. The damper housing 16 is an integrally molded product including a housing main body (die-cast part) 21 and a lower coupling part 23. The housing main body 21 includes an upper coupling portion 22, a top plate 24, and a peripheral wall portion 25.

  The top plate 24 is a substantially flat plate-like portion having a substantially rectangular shape in plan view, and includes a hole 24a for attaching the upper end portion of the damper and a plurality of damper flange mounting holes 24b.

  The peripheral wall portion 25 is a vertical wall that extends in an approximately U shape from the upper coupling portion 22 that contacts the upper member 13 and the lower member 14 toward the lower coupling portion 23 that joins the front side frame 12. The peripheral wall 25 includes a front wall 27 formed in the front, a rear wall 28 formed in the rear, a side wall 29 formed in the side, and a front corner wall connecting the side wall 29 and the front wall 27. 31 and a rear corner wall 32 connecting the side wall 29 and the rear wall 28. Specifically, the lower joint portion 23 is a portion that is integrally cast into the housing body 21 at the lower end of the side wall 29.

  By forming the front and rear corner walls 31 and 32 on the housing body 21, stress concentration at the corners of the housing body 21 can be reduced. As a result, the rigidity of the damper housing 16 can be increased.

  The upper coupling portion 22 is a portion that holds the upper member 13 and the lower member 14 by casting, and is provided on the upper side portion of the damper housing 16.

  The lower coupling portion (iron member) 23 is formed of the same material as that of the front side frame 12. That is, the lower joint portion 23 is made of a steel material such as steel and is welded to the front side frame 12 at a plurality of welding locations. Further, as shown in FIG. 2, when the light metal melted at the time of die casting is poured into the lower joint portion 23, an anchor hole in which an anchor portion 42 is formed on the housing body 21 side is formed in the burring hole 41. Is formed. A plurality of anchor portions 42 and burring holes 41 are provided. The lower coupling part 23 is a joint part formed integrally with the die cast part 21.

  The dissimilar joint structure 40 is configured by the housing main body 21, the lower coupling portion 23, the anchor portion 42, and the burring hole 41 described above. Hereinafter, the housing body 21 is referred to as “die-cast component 21”, and the lower coupling portion 23 is referred to as “iron member 23”.

  As shown in FIG. 3, in the dissimilar joint structure 40, the burring holes 41 of the iron member 23 are arranged in a staggered manner. Thus, the tensile strength between the iron member 23 and the light alloy die-cast part 21 can be further increased.

  As shown in FIG. 4, in the iron member (lower coupling portion) 48 of another embodiment, the burring holes 49 are arranged in a plurality of rows. Accordingly, the tensile strength between the iron member 48 and the light alloy die-cast part 21 can be further increased.

  As shown in FIGS. 5 and 6, in the dissimilar joint structure 40, the iron member 23 is cast by a light alloy die-cast part 21. Since the anchor hole 41 is provided in the iron member 23 and the anchor hole 41 is formed as a burring hole, the tensile strength is increased by increasing the cross-sectional area between the adjacent anchor holes 41 on the iron member (steel) 23 side. be able to. Furthermore, stress concentration of the iron member (steel) 23 can be prevented, and the area around the anchor hole 41 that is expected to be weakest on the iron member 23 side can be reinforced. Thereby, the fracture | rupture expected location of the iron member 23 can be strengthened.

  As a result, even when the diameter of the anchor portion 42 of the light alloy such as aluminum (die-cast part 21) formed in the anchor hole 41 is set large, a decrease in the breaking load of the anchor hole 41 between the anchor holes is prevented. Overall, it is possible to ensure a balance in strength between the light-alloy die-cast component 21 and the iron member (joint component) 23 that casts the iron member 23.

FIG. 7A shows the iron member 103 of the dissimilar joint structure 100 of the comparative example. In addition, the dissimilar joint structure 100 of a comparative example describes the dissimilar joint structure 100 shown by FIG. 15 (a), (b) as a comparative example.
The anchor hole 111 on the iron member 103 side is formed by a simple hole (pierce) having a diameter d. In the iron member 103 of the comparative example, the height in the drawing direction of the simple hole (pierce) 111 is h1.

  FIG. 7B shows the iron member 23 of the dissimilar joint structure 40 of the embodiment. The anchor hole 41 on the iron member 23 side is formed by a burring hole (burring) having a diameter d. In the iron member 23 of the embodiment, the height in the pulling direction of the burring hole (burring) 41 is h2.

7 (c) and 7 (d), the cross-sectional area S1 between the inner walls of the adjacent simple holes 111, 111 of the iron member 103 of the dissimilar joint structure 100 of the comparative example, the adjacent burring holes of the iron member 23 of the embodiment are shown. The cross-sectional area S2 between the inner walls of 41 and 41 is shown.
The cross-sectional area S1 between the inner walls of the simple holes is represented by Lxh1, and the cross-sectional area S2 between the inner walls of the burring holes is approximated to Lxh1 + 2h1 (h2-h1). Since h2> h1, the sectional area S2 between the inner walls of the burring holes 41, 41 is larger than the sectional area S1 between the inner walls of the simple holes 111, 111 (S2> S1).

  Thus, by forming a burring hole, the cross-sectional area S2 between the inner walls of the burring holes 41 and 41 of the iron member 23 is larger than the cross-sectional area S1 between the inner walls of the adjacent simple holes 111 and 111 of the iron member 103. be able to.

That is, the tensile strength of the iron member 23 itself can be improved and the prevention of breakage of the iron member 23 can be enhanced. As a result, it is possible to increase the tensile strength until the end portion break A4 of the iron member 103 and the break A5 between the anchor holes 111 shown in FIG.
The above-described “increase in tensile strength due to an increase in cross-sectional area (S2-S1) between inner walls of adjacent burring holes 41, 41 of the iron member 23” will be referred to as a first effect.

  8A and 8B show dissimilar joints when a tensile load is applied to the die-cast part 21 and the iron member 23 as indicated by the white arrows B1 and B1 in a direction orthogonal to the direction in which the burring hole 41 is pulled out. Structure 40 is shown. 2A is a perspective view of the dissimilar joint structure 40, and FIG. 2B is a cross-sectional view of the dissimilar joint structure 40.

  When a tensile load is applied to the die-cast part 21 and the iron member 23 as indicated by the white arrows B1 and B1 in a direction orthogonal to the direction in which the burring hole 41 is drawn, the burring of the iron member 23 is performed as shown in FIG. The vertical wall 41a of the hole 41 generates a pressing force N1 that presses the inside 21a of the die cast part 21 that is located on the left side of the drawing and contacts the interface, and the inside 21a of the die cast part 21 has a reaction force N2 that pushes back the burring hole 41. Occur. 8B, a bent portion 43 is formed on the lower surface of the burring hole 41. As shown in FIG.

  In the dissimilar joint structure 40, since the pressing force N1 and the reaction force N2 can be greatly increased as compared with the dissimilar joint structure 100 of the comparative example (see FIG. 7A), the tensile strength up to the fracture on the iron member 23 side. Can be improved. As a result, it is possible to increase the tensile strength until the end portion break A4 of the iron member 103 and the break A5 between the anchor holes 111 shown in FIG. The “increase in tensile strength by the vertical wall 41a of the burring hole 41 on the iron member 23 side” described above is referred to as a second effect.

FIG. 9A shows the dissimilar joint structure of the comparative example, and FIG. 9B shows the dissimilar joint structure of the example.
In the dissimilar joint structure 100 of the comparative example, when a tensile load is applied to the die cast member (base material) 101 and the iron member 103 in a direction orthogonal to the direction in which the simple hole 111 is drawn, the anchor portion 112 of the die cast component 101 is applied. A shear load f1 is generated on the upper surface of the die cast part, and a shear load f2 equal to the shear load f1 is generated on the lower surface of the anchor portion 112 of the die cast part 101. f3 occurs.

  In the dissimilar joint structure 40 of the embodiment, when a tensile load is applied to the die cast part 21 and the iron member 23 in a direction orthogonal to the pulling direction of the burring hole 41, the upper surface of the anchor part 42 of the die cast part 21 is sheared. A load f4 is generated, a shear load f5 is generated on the lower surface of the anchor portion 42 of the die-cast part 21, and a reaction force f6 that is balanced with the shear load f4 + f5 is generated in the opposite direction of the shear loads f4 and f5.

  When comparing the dissimilar joint structure 100 of the comparative example and the dissimilar joint structure 40 of the example, the shear load f1 = shear load f4. In the dissimilar joint structure 40 of the embodiment, the shear load f5 on the lower surface is larger than the shear load f2 (f5> f2) because the bent portion 43 is present on the lower surface of the burring hole 41.

  That is, in the dissimilar joint structure 40 of the embodiment, the shear load f <b> 5 on the lower surface can be earned by increasing the shear area due to the bent portion 43 of the burring hole 41. That is, the tensile strength of the anchor portion 41 of the die cast part 21 can be improved. Thereby, the tensile strength up to the fracture of the shear fracture A2 at the anchor portion 111 shown in FIG. 15B can be increased. The above-described “increase in tensile strength due to increase in shear area due to the bent portion 43 of the anchor portion 42 on the die-cast part 21 side” is described as a third effect.

FIG. 10A shows a shear fracture A2 at the anchor portion 112 of the dissimilar joint structure 100 of the comparative example, an end portion fracture A4 of the iron member 103, and an anchor hole fracture A5 of the anchor hole 111. In FIG. 10A, the vertical axis represents the tensile strength.
The tensile strength a2 at the shear fracture A2 at the anchor portion 112, the tensile strength a4 at the end fracture A4 of the iron member 103, and the tensile strength a5 at the anchor hole fracture A5 of the anchor hole 111 are represented.

FIG. 10B shows a shear fracture B2 at the anchor portion 42 of the dissimilar joint structure 40 of the embodiment, an end portion fracture B4 of the iron member 23, and an anchor hole fracture B5 of the anchor hole 41. In FIG. 10B, the vertical axis represents the tensile strength.
The tensile strength b2 at the shear break B2 at the anchor portion 42, the tensile strength b4 at the end portion break B4 of the iron member 23, and the tensile strength b5 at the anchor hole break B5 of the anchor hole 41 are represented. Note that the breaks B2, B4, and B5 are the same break forms (including break positions) as the breaks A2, A4, and A5 shown in FIG.
As shown in FIG. 10B, in the dissimilar joint structure 40 (see FIG. 5) of the embodiment, the tensile strength b2 is represented by a2 + α2, and the shear fracture A2 at the anchor portion 112 (see FIG. 10a). On the other hand, the tensile strength α2 is improved.
The tensile strength b4 is represented by a4 + α4, and is improved by the tensile strength α4 with respect to the end break A4 (see FIG. 10A) of the iron member 103.
The tensile strength b5 is represented by a5 + α5, and is improved by a tensile strength α5 with respect to the anchor hole break A5 (see FIG. 10A).

  That is, in the dissimilar joint structure 40 (see FIG. 5), the anchor hole 41 is a burring hole. Therefore, the shear breaking load A2 (see FIG. 10A) at the anchor portion 112 of the dissimilar joint structure 100 of the comparative example can be increased by the tensile strength α2 by the effect 3 described above. The end fracture A4 of the iron member 103 can be increased by the tensile strength α4 due to the effects 1 and 2 described above. The anchor hole breakage A5 of the anchor hole 111 can be increased by the tensile strength α5 due to the effects 1 and 2 described above.

11 (a) to 11 (d) and FIG. 12, the dissimilar joint structure 50 of Example 2 will be described. The dissimilar joint structure 50 is the same structure as the dissimilar joint structure 40 except for the diameter d2 of the burring hole 61 and the diameter d2 of the anchor portion 62. That is, as shown in FIG. 11A, the dissimilar joint structure 50 shows the idea of reducing the diameter of the burring hole 61. The vertical axis represents the tensile strength.
The tensile strength c2 at the shear break C2 at the anchor portion 62 and the tensile strength c5 at the anchor hole (burring hole) 61 at the anchor hole break C5 are represented. The breaks C2 and C5 have the same breakage form (including breakage positions) as the breaks A2 and A5 shown in FIG.

Moreover, the dissimilar joint structure 100 of a comparative example is shown by FIG.11 (b). FIG. 11C shows the dissimilar joint structure 40 of the embodiment. FIG. 11D shows the dissimilar joint structure 50 according to the second embodiment.
In the dissimilar joint structure 50 of Example 2, the diameter d of the burring hole 41 of the dissimilar joint structure 40 was reduced to the diameter d2 (d2 <d).

For example, the aim of the dissimilar joint structure 40 of the example is to improve the tensile strength a5 of the anchor hole break A5 of the anchor hole 111 which is the weakest in the dissimilar joint structure 100 of the comparative example. For this purpose, in the dissimilar joint structure 40 of the embodiment, a method of reducing the diameter d of the burring hole 41 and improving the tensile strength a5 of the shear fracture A2 at the anchor portion 112 is conceivable.
By the way, in the dissimilar joint structure 50 of Example 2, the burring hole 61 was reduced to the diameter d2. Therefore, since the burring hole 61 is reduced to the diameter d2, the tensile strength c2 of the anchor portion 62 in the shear fracture C2 is greater than the tensile strength b2 in the shear fracture B2 of the anchor portion 42 of the dissimilar joint structure 40 of the embodiment. Also decreases.

  However, if the tensile strength c2 of the shear fracture C2 of the anchor portion 62 is equal to the tensile strength a2 of the shear fracture A2 at the anchor portion 112 of the dissimilar joint structure 100 of the comparative example, the anchor portion 62 The tensile strength c2 of the shear break C2 is sufficiently higher than the anchor hole break A5 of the anchor hole 111. That is, as long as the tensile strength a2 of the shear fracture A2 at the anchor portion 112 can be maintained, there is no problem as a dissimilar joint structure (joint).

  In the dissimilar joint structure 50 of Example 2, the distance between the anchor holes 61 can be increased, and the tensile strength c5 at the anchor hole (burring hole) 61 between the anchor holes C5 is determined as the dissimilar joint structure 100 of the comparative example. The tensile strength c5 can be improved by α6 as compared to the tensile strength a5 of the anchor hole 111 up to the fracture A5 between the anchor holes. The “increase in the tensile strength of the break between the anchor holes 61” described above is referred to as a fourth effect.

  Thus, in the idea of reducing the diameter d2 as in the burring hole 61, the shear fracture B2 at the anchor portion 41 is improved by the burring hole 41 as in the dissimilar joint structure 40 of the embodiment. The anchor diameter (same as the diameter d2 of the burring hole 61) can be reduced. Therefore, the diameter of the burring hole 61 of the iron member 53 can be reduced to a level at which the tensile strength of the anchor portion 112 of the simple hole 111 of the dissimilar joint structure 100 of the comparative example can be maintained.

  Thereby, the tensile strength c5 at the anchor hole break C5 of the anchor hole (burring hole) 61 on the iron member 51 side can be improved, and the tensile strength of the iron member 51 can be improved comprehensively. it can. In addition, the anchor hole (burring hole) 61 has a first and second effects, as will be described later, in the break C5 between the anchor holes.

As shown in FIG. 12, in the dissimilar joint structure 50 of Example 2, the tensile strength c2 of the shear fracture C2 of the anchor portion 62 is different from that of the dissimilar joint structure 100 of the comparative example (see FIG. 10A). The tensile strength a2 is maintained. In the end portion break C4 of the iron member 53, the first and second effects are added, and the tensile strength c4 can be improved. At the anchor hole (burring hole) 61 between the anchor holes C5, the first and second effects are added in addition to the fourth effect described above, and the tensile strength c5 can be improved.
In FIG. 12, the vertical axis represents the tensile strength. Moreover, the edge part fracture | rupture C4 of the iron member 53 is a fracture | rupture form (a fracture | rupture position is also included) similar to fracture | rupture A4 shown by Fig.15 (a).

  The dissimilar joint structure 50 of Example 2 explains the manufacturing method of a dissimilar joint structure. That is, in the manufacturing method of the dissimilar joint structure, the iron member 53 is casted with a light alloy to manufacture the dissimilar joint structure 50. An anchor hole 61 is provided in the iron member 53, and this anchor hole 61 is formed as a burring hole. At this time, the diameter of the burring hole 61 is set to be small until the tensile strength of the light alloy injection portion into the anchor hole (burring hole) 61 becomes substantially the same as that of the simple hole 111. The distance between the anchor holes 61, which is expected to be the weakest on the iron member 53 side, can be set longer as the diameter d2 is reduced, thereby increasing the tensile strength around the anchor holes 61. it can. As a result, the strength of the dissimilar joint structure 50 can be further increased as a whole.

  As shown in FIG. 1, the dissimilar joint structure according to the present invention is composed of a housing body (die-cast part) 21 and a lower coupling member (iron member) 23, but is not limited thereto.

In the dissimilar joint structure according to the present invention, as shown in FIG. 1, the die-cast part 21 is not limited to aluminum but may be other light metals such as magnesium.
Further, the member cast on the die-cast component 21 is not limited to an iron member, but may be another metal such as aluminum.

  The dissimilar joint structure according to the present invention is suitable for use in passenger cars such as sedans and wagons.

  21, 51 ... Die-cast parts, 23, 53 ... Iron members, 40, 50 ... Dissimilar joint structure, 41, 61 ... Anchor holes (burring holes), 42, 62 ... Anchor parts.

Claims (1)

A method for manufacturing a dissimilar joint structure in which an iron member is cast with a light alloy,
When the anchor hole is provided in the iron member and the anchor hole is formed in the burring hole, the diameter of the burring hole is substantially the same as the case where the tensile strength of the light alloy injection portion of the anchor hole is a simple hole. A method for manufacturing a dissimilar joint structure, characterized in that the setting is made small until the tensile strength is reached.

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