JP2024031998A - structural members - Google Patents

Abstract

The present invention provides a structural member manufactured with high precision while ensuring sufficient rigidity. A structural member (100) includes an extruded material panel (11) and a joint portion (31). The joint part 31 has a total wall thickness of the extruded material panel 11 of 15 mm or less, and includes a first stirring joint part 33 and a second stirring joint part 35 formed on the front side and the back side of the extruded material panel 11, and a shoulder stirring surface. has. The extruded material panel 11 is a hollow shaped member in which a welded part having a bonding interface between materials formed by extrusion molding is formed in a part of the thickness direction, and the surface side of the extruded material panel 11 in the thickness direction A first stirring joint 33 is formed in the range from 11b to the interface WL of the weld, and a second stirring joint 35 is formed in the range from the back side surface 11c to the interface WL of the weld. The part 33 and the second stirring joint part 35 are formed without spanning the interface WL of the weld part. [Selection diagram] Figure 15

Description

The present invention relates to structural members.

BACKGROUND ART Conventionally, there has been a demand for improving the safety of occupants in vehicles, and for this purpose, the strength of vehicle bodies has been improved. On the other hand, moves to improve the fuel efficiency of automobiles are accelerating against the backdrop of worsening problems such as global warming. It is known that reducing the weight of a vehicle body is effective in improving fuel efficiency. Further, progress is being made in the development of vehicles that run on electricity (including electric vehicles, hybrid vehicles, etc.) and devices such as self-propelled robots. A battery system mounted on such a vehicle or device generally has a configuration in which a large number of batteries (batteries, battery cells) are housed in a battery tray.

Patent Document 1 discloses, as a battery pack structure that accommodates a plurality of battery packs, an outer frame body in which a pair of front frames and a rear frame are connected by left and right side frames, respectively, and a bottom side of the outer frame body. A cooling member is disclosed in which the cooling member has an upper cooling layer and a lower cooling layer stacked on top of each other to form a cooling flow path inside.

Further, Patent Document 2 discloses a battery storage structure in which a battery storage portion is formed inside by a bottom portion and a side wall portion erected from the bottom portion, and the bottom portion has a heat pipe structure.

Further, Patent Document 3 discloses a vehicle battery case structure in which a battery module accommodating portion is formed by a first side member and a second side member that are arranged to face each other. In this battery case structure, one or both of the first side member and the second side member has a skeleton hollow part located on the side side of the battery module and an under hollow part located on the lower side of the battery module. A clearance hollow part is provided between the housing bottom part of the housing part of the battery module and the under hollow part, and the skeleton hollow part, the clearance hollow part, and the under hollow part are integrally formed.

Further, Patent Document 4 discloses a technique for joining members together by friction stir welding the joint portions from the front and back sides.

JP 2021-140863 Publication Japanese Patent Application Publication No. 2020-19291 JP 2021-70386 Publication Patent No. 4838385

By the way, in the structure described in Patent Document 1, since the cooling member serving as the bottom thereof is formed by stacking thin plate-shaped upper cooling layer and lower cooling layer, sufficient rigidity cannot be ensured. is difficult.

In addition, when the structures described in Patent Documents 2 to 4 form the bottom by butting and joining the end surfaces of a plurality of extruded materials, heat and stress are concentrated at the joints, which tends to cause distortion, and the structure is expensive. It is difficult to manufacture with precision.

Therefore, an object of the present invention is to provide a structural member manufactured with high precision while ensuring sufficient rigidity.

The present invention consists of the following configuration.
A structural member having a plurality of extruded material panels, at least one of which has a plurality of rows of hollow portions along the extrusion direction, and a joint portion in which edges of the extruded material panels are butted and friction stir welded,
The joint portion is
The total thickness of the extruded material panel in the thickness direction is 15 mm or less,
a first stirring joint formed on the front side of the extruded material panel;
a second stirring joint formed on the back side of the extruded material panel;
Shoulder stirring surfaces formed along the edges on the front side and the back side of the extruded material panel, respectively;
has
The extruded material panel is a hollow shaped member in which a welded part having a bonding interface between materials by extrusion molding is formed in a part of the thickness direction,
Regarding the thickness direction, the first stirring joint is formed in a range from the front side surface of the extruded material panel to the interface of the welded part, and the range from the back side surface to the interface of the welded part. The second stirred joint is formed in the weld, and the first stirred joint and the second stirred joint are formed without spanning the interface of the welded part.
Structural members.

According to the present invention, it is possible to provide a structural member manufactured with high precision while ensuring sufficient rigidity.

FIG. 1 is a perspective view of a structural member according to this configuration example. FIG. 2 is a side view of the structural member according to this configuration example. FIG. 3 is a side view of a portion of the structural member. FIG. 4 is a perspective view of the joint portion of the structural member. FIG. 5 is a side view of the joint portion of the structural member. FIG. 6A is a perspective view of the extruded material panel placed on the base for explaining the first placement step and the first pressing step. FIG. 6B is a side view of the extruded material panel placed on the base for explaining the first placement step and the first pressing step. FIG. 7A is a perspective view of the extruded material panel placed on the base for explaining the first pressing step. FIG. 7B is a side view of the extruded material panel placed on the base for explaining the first pressing step. FIG. 8 is a side view of the extruded material panel placed on the base for explaining a reference example of the pressing method using the pressing jig in the first pressing step. FIG. 9A is a perspective view of the extruded material panel placed on the base for explaining the first bonding step. FIG. 9B is a side view of the extruded material panel placed on the base for explaining the first bonding step. FIG. 10 is a side view of the extruded material panel placed on the base, with the pressing jig and holding jig removed. FIG. 11 is a side view of the extruded material panel placed on the base for explaining the second placement step, the second pressing step, and the second pressing step. FIG. 12 is a side view of the extruded material panel placed on the base for explaining the second bonding step. FIG. 13 is a side view of the extruded material panel placed on the base for explaining machining after joining the extruded material panels. FIG. 14 is a perspective view of a machined structural member. FIG. 15 is a partially enlarged sectional view of a structural member in which the edges of extruded material panels are friction stir welded together. FIG. 16 is a photograph of a cross section when friction stir welding is performed from one surface of an extruded material panel to an area beyond the welded part. FIG. 17 is a photograph of a cross section when friction stir welding is performed on both sides of an extruded material panel within a range not exceeding the welded portion.

Embodiments of the present invention will be described in detail below with reference to the drawings.
FIG. 1 is a perspective view of a structural member 100 according to this configuration example. FIG. 2 is a side view of the structural member 100 according to this configuration example.
As shown in FIGS. 1 and 2, the structural member 100 according to this configuration example is a plate-shaped structure, and is composed of a plurality of (two in this example) extruded material panels 11. . The structural member 100 is constructed by joining the side surfaces of the extruded material panel 11 along the extrusion direction to each other. The shapes of the extruded material panels 11 illustrated here are all rectangular in plan view. Hereinafter, the thickness direction of the extruded material panel 11 will be referred to as the Z direction, the direction parallel to the extrusion direction and along one side of the rectangle will be referred to as the Y direction, and the direction along the other side of the rectangle perpendicular to that one side, orthogonal to the Y and Z directions. will be explained assuming that it is the X direction.

As the extruded material panel 11, a plate-shaped extruded material made of aluminum or an aluminum alloy is used. The aluminum alloy used for the extruded material panel 11 is preferably an aluminum alloy such as 5000 series, 6000 series, or 7000 series according to JIS or AA standards, since it has excellent strength and can be made thinner. These hollow extruded aluminum alloy sections are produced by appropriately combining heat treatment such as casting (DH casting method or continuous casting method), homogenization heat treatment, hot extrusion, solution treatment and quenching treatment, and if necessary, artificial aging treatment. The manufactured product can be suitably used. According to this, the structural member 100 can be made lightweight and have a high strength structure.

FIG. 3 is a side view of a portion of structural member 100. The structural member 100 includes a plurality of extruded material panels 11, at least one of which has a plurality of rows of hollow portions 13A, 13B, and 13C along the extrusion direction, and the edges of the extruded material panels 11 are butted against each other and friction stir welded. It has a joint part 31. In the extruded material panel 11 of the structural member 100 shown in FIG. 3, a plurality of rows of hollow parts 13A, 13B, and 13C are formed in the center of the thickness direction (Z direction) along the extrusion direction (Y direction). There is. Ribs 15 are formed between the hollow parts 13A and 13B that are adjacent to each other in the extruded material panel 11, and between the hollow parts 13B and 13C that are adjacent to each other.

In the extruded material panel 11, a wide hollow portion 13A, a narrow hollow portion 13B, and a wide hollow portion 13B are formed in line in this order from the edges facing each other toward the pressing jig 45. , the width, thickness, shape, etc. of each hollow portion 13A, 13B, 13C can be set arbitrarily.

The extruded material panel 11 is, for example, formed into a flat thin plate shape with a thickness T1 of 15 mm or less. The thickness T2 of the hollow part 13A (the same applies to the hollow parts 13B and 13C) of the extruded material panel 11 is about half the thickness T1 of the extruded material panel 11, and the width of the rib 15 of the extruded material panel 11 in the X direction. It is preferable that Wr is at least half the thickness T2 of the hollow portions 13A, 13B, and 13C.
This ensures sufficient strength of the extruded material panel 11 having the hollow portions 13A, 13B, and 13C.

Next, the structure of the joints between the extruded material panels 11 will be described in detail.
FIG. 4 is a perspective view of the joint portion 31 of the structural member 100. FIG. 5 is a side view of the joint portion 31 of the structural member 100.

As shown in FIGS. 4 and 5, in the structural member 100, the edges of the extruded material panels 11 are butted against each other and friction stir welded. This friction stir welded portion becomes the joint portion 31. The joint portion 31 includes a first stirring joint portion 33 formed on one side, which is the front side, and a second stirring joint portion 35, formed on the back side, which is the other side, in the plate thickness direction (Z direction). and has. The first stirring joint part 33 and the second stirring joint part 35 each have a shoulder stirring surface 37 formed in the longitudinal direction (Y direction) along the edge. The shoulder stirring surface 37 is a stirring surface formed on the surface layer of the joint when the shoulder part of the friction stirring tool rotates, presses, and slides, and is also called a shoulder mark, and is a stirring surface that extends over the entire length of the joint part 31 in the longitudinal direction. It is formed.

The joint portion 31 has a total wall thickness T3 of the extruded material panel 11 in the thickness direction of 15 mm or less (see FIG. 3), preferably 12 mm or less, more preferably 10 mm or less, and a depth D1 of the first stirring joint portion 33. The lower limit of the depth D2 of the second stirring joint portion 35 is 2 mm or more, preferably 3 mm or more, and the upper limit is 5 mm or less, preferably 4 mm or less. Thereby, sufficient bonding strength in the joint portion 31 is ensured on the front and back sides. Note that the total thickness T3 of the joint portion 31 is the same or approximately the same as the thickness T1 of the extruded material panel 11.

A solid portion 17 is formed at the edge of the extruded material panel 11. The width L of this solid portion 17 from the end face of the edge of the extruded material panel 11 to the edge side end of the hollow portion 13A disposed closest to this edge in the X direction is equal to the width L of the joint portion 31. The half value (Wtf/2) of the width Wtf of the shoulder stirring surface 37 formed on the front and back sides of The total dimension including the width Wr in the X direction (see FIG. 3) is greater than or equal to (L≧Wtf/2+Wr).

As a result, the structural member 100 has a well-balanced and stable bonding strength between the extruded material panels 11 on the front and back sides at the joint 31 having the first stirred joint 33 on the front side and the second stirred joint 35 on the back side. It is joined. Therefore, a structural member 100 with sufficient strength in the joint portion 31 and its surroundings can be obtained.

Next, a method for manufacturing the above structural member 100 will be explained.
6A and 6B are perspective views of the extruded material panel placed on the base for explaining the first placement step and the first pressing step. 7A and 7B are perspective views of the extruded material panel placed on the base for explaining the first pressing step.

As shown in FIGS. 6A and 6B, two extruded material panels 11 to be joined to each other are set on the base 41 (first placement step). Specifically, two extruded material panels 11 are arranged side by side in a flat shape on the smooth surface 43 consisting of the upper surface of the base 41, and the edges of these extruded material panels 11 are butted against each other.

Next, the two extruded material panels 11 placed on the smooth surface 43 of the base 41 are pressed in a direction toward each other within the smooth surface 43 so that their edges butt together (first pressing step). Specifically, pressing jigs 45 are attached to the opposite edges of the extruded panels 11 placed on the base 41, and the extruded panels 11 are pressed together by these pressing jigs 45. Push them closer together. The pressing jig 45 is formed into a long prismatic shape and has a holding recess 46 on the extruded material panel 11 side. The pressing jig 45 is attached to the base 41 so that the edge of the extruded material panel 11 is fitted into the holding recess 46 . As a result, the edge of the extruded material panel 11 is held by the pressing jig 45 over the entire length in the longitudinal direction. The extruded material panel 11 held by the pressing jig 45 is pressed in the abutting direction by one side wall 46a forming the holding recess 46, and is further pressed against the smooth surface 43 of the base 41 by the other side wall 46b forming the holding recess 46. be forced to.

Then, as shown in FIGS. 7A and 7B, the extruded panels 11 with their edges butted against each other are pressed against the smooth surface 43 from the other side of the base 41 with the extruded panels 11 interposed therebetween (first pressing step). . In order to press the extruded material panel 11 onto the smooth surface 43 of the base 41, a pair of pressing jigs 47 and a pair of pressing jigs 49 are used.

The pair of holding jigs 47 are formed into a flat plate shape that is elongated in the Y direction, and at least the surface that contacts the extruded material panel 11 is a flat portion 47a. Each holding jig 47 is arranged at a position corresponding to the hollow part 13B at the center of the extruded material panel 11 in the Z direction, and has a width dimension larger than the width of the hollow part 13B in the X direction. The holding jig 47 is placed so that both ends of the holding jig 47 in the X direction touch the rib 15 at a position corresponding to the hollow part 13B of each extruded material panel 11, that is, so that it overlaps the rib 15 in the thickness direction of the extruded material panel 11. Placed.

The pair of holding jigs 49 are formed in the shape of a long rod in the Y direction, and at least the surface that contacts the extruded material panel 11 is a flat portion 49a. Each holding jig 49 is arranged near the edges of the extruded material panel 11 that are butted against each other, at a position that spans the solid portion 17, that is, so as to overlap the solid portion 17 in the thickness direction of the extruded material panel 11. Ru. A pair of presser jigs 49 placed on each extruded material panel 11 are spaced apart from each other in the X direction from the butt portions of the extruded material panels 11 .

In this way, a load is applied to each of the holding jigs 47 and 49 placed on the extruded material panel 11 toward the base 41 by a load applying means such as a clamper or a weight. As a result, the extruded material panel 11 on the base 41 is pressed against the smooth surface 43 of the base 41 over its entire length in the longitudinal direction (Y direction) by the holding jigs 47 and 49 without any gaps.

In addition, it is preferable that the pressing jig 45 as well as the holding jigs 47 and 49 apply a load toward the base 41 by a load applying means.

FIG. 8 is a side view of the extruded material panel placed on the base for explaining a reference example of the pressing method using the pressing jig in the first pressing step.
In the reference example shown in FIG. 8, two flat pressing jigs 47 are arranged on the top of each extruded material panel 11. One holding jig 47 is disposed above the hollow portion 13C, and the other holding jig 47 is disposed at a position where the center of the width in the X direction is directly above the rib 15. These pressing jigs 47 are arranged at positions where both ends in the X direction do not overlap the ribs 15, that is, do not overlap with the ribs 15 in the thickness direction of the extruded material panel 11. Further, the holding jig 49, which is placed near the edges of the extruded material panels 11 that are butted against each other, is placed on the hollow portion 13A.

As described above, in the case of the reference example in which both ends of the holding jig 47 in the X direction are arranged at positions where they do not overlap the ribs 15 and the holding jig 49 is arranged above the hollow part 13A, the hollow part 13A in the extruded material panel 11 , 13B, and 13C, there is a risk that the thinner portions may be deformed by the load from the holding jigs 47, 49.

In contrast, in this configuration example, as shown in FIGS. 7A and 7B, the holding jig 47 is arranged so that both ends of the holding jig 47 in the It is arranged so as to cover part 17. Therefore, even if the extruded material panel 11 is pressed toward the base 41 by these pressing jigs 47 and 49, the load is received by the ribs 15 and the solid portion 17, so that the extruded material panel 11 can be made thin. Deformation of the area can be suppressed.

9A and 9B are perspective views of the extruded material panel 11 placed on the base 41 for explaining the first joining step. FIG. 10 is a side view of the extruded material panel 11 placed on the base 41, with the pressing jig 45 and holding jigs 47, 49 removed.

As shown in FIGS. 9A and 9B, the abutted edges of the extruded material panels 11 are friction stir welded from the front side (one side on the holding jig 49 side) using the friction stir tool Tf (first joining step). Specifically, the friction stirring tool Tf is inserted from above between the pair of holding jigs 49, and the joining line formed by the butted edges of the extruded material panels 11 (the edges along the Y direction The friction stir tool Tf is moved along an imaginary line (not shown) to friction stir join the abutted edges. As a result, first stirring joints 33 are formed at each edge of the extruded material panel 11. Then, a joint portion 31 joined from one side by the first stirring joint portion 33 is formed at the butt portion of the extruded material panel 11. In addition, when performing friction stir welding using the friction stir tool Tf, first, the ends of the joining line are temporarily joined by friction stir welding along the Y direction with a length of about 50 mm, and then the temporary joining location is It is preferable to perform friction stir welding over the entire length of the joining line.

After the first stirring joint portion 33 is formed by the friction stirring tool Tf, the pressing jig 45 and the holding jigs 47 and 49 are removed or moved to retreat. Then, as shown in FIG. 10, due to the stress applied by the friction stir welding, the extruded panels 11 that are joined to each other are warped, with both ends in the X direction lifting up from the base 41, with the joint portion 31 as the center of bending. Occurs slightly. The warping that occurs on one side and the other of the two extruded panels 11 with this joint portion 31 as a boundary can be avoided by pressing the extruded panels 11 against the smooth surface 43 of the base 41 using holding jigs 47 and 49 during friction stir welding. It can be suppressed. However, it is difficult to completely eliminate warping, and the two extruded panels 11 friction stir welded to each other on one side in the thickness direction are It gradually rises slightly upward from the smooth surface 43 of the base 41 toward the outer edge. As a result, a small gap G remains between the outer edge of the extruded material panel 11 and the smooth surface 43 of the base 41.

Therefore, a step is performed to eliminate the remaining gap G. FIG. 11 is a side view of the extruded material panel placed on the base for explaining the second placement step, the second pressing step, and the second pressing step. FIG. 12 is a side view of the extruded material panel placed on the base for explaining the second bonding step.

As shown in FIG. 11, the two extruded material panels 11 joined on the front side are turned over and placed again on the smooth surface 43 of the base 41 (second placement step). Then, the extruded material panels 11 are pressed in a direction toward each other within the smooth surface 43 using the pressing jig 45, so that the ends are butted against each other (second pressing step). Furthermore, the pressing jigs 47 and 49 are brought into contact with the extruded material panel 11 again from the other side of the base 41 with the extruded material panel 11 interposed therebetween, and the extruded material panel 11 is pressed against the base 41 (second pressing step).

At this time, in the two extruded material panels 11 joined to each other, there is a slight warp on one side and the other side of the two extruded material panels 11 with the joint portion 31 as a boundary. Therefore, when the two extruded panels 11 joined to each other are turned over and placed again on the smooth surface 43 of the base 41, the central portion having the joint portion 31 is slightly raised. However, by pressing the extruded material panel 11 against the base 41 using the holding jigs 47 and 49, the slight lifting of the central portion can be eliminated. Thereby, the extruded material panel 11 with the front and back reversed can be placed on the base 41 in a flattened state.

As shown in FIG. 12, the joint portion 31 joined at the first stir joint portion 33 of the extruded material panel 11 is friction stir welded from the above-mentioned back side using the friction stir tool Tf. That is, friction stir welding is performed along the joining line from one side of the extruded material panel 11 on the presser jigs 47 and 49 side (second joining step). As a result, a second stirring joint portion 35 is formed at the joint portion 31 of the extruded material panel 11. In addition, when performing friction stir welding on the back side, first, the end portion of the joining line is temporarily joined by friction stirring welding along the Y direction with a length of about 50 mm, and then the joining line including the temporary joining location is It is preferable to perform friction stir welding over the entire length.

After the second stirring joint portion 35 is formed by the friction stirring tool Tf, the pressing jig 45 and the holding jigs 47 and 49 are removed or moved to retreat. As a result, a structural member 100 in which two extruded material panels 11 are joined at the joint portion 31 is obtained. In the structural member 100 obtained in this way, the warpage caused by friction stir welding is canceled out on the front and back sides, so that there is almost no deformation such as warpage.

As described above, according to this configuration example, it is possible to manufacture the structural member 100 in which the extruded material panels 11 are joined on the front and back sides in a well-balanced manner at the joint portion 31. In addition, when performing friction stir welding, the extruded panels 11 are pressed in the direction toward each other, and the extruded panels 11 are also pressed against the base 41 in the thickness direction. Warpage that occurs can be suppressed. Moreover, by performing friction stir welding from the front and back sides, it is possible to offset the warpage that occurs at the joining location. As a result, a high-quality structural member 100 in which warping is suppressed and the extruded material panels 11 are joined together in a flat manner can be obtained.

Note that after forming the second stirring joint portion 35 in the joint portion 31, mechanical processing such as deburring or trimming may be performed on the extruded material panel 11 as necessary.

Here, machining of the extruded material panels 11 after joining will be explained. FIG. 13 is a side view of the extruded material panel 11 placed on the base 41 for explaining machining after the extruded material panels 11 are joined. FIG. 14 is a perspective view of a structural member 100 that has been machined.

As shown in FIG. 13, after the second agitation bonding portion 35 is formed through the steps described above, some of the holding jigs 47 and 49 are removed or moved to retreat. For example, in a machine tool such as a machining center, a cutting tool Tc such as a reamer is replaced with the friction stirring tool Tf, and the structural member 100 is machined using this cutting tool Tc. For example, as shown in FIG. 14, a portion of one side of the structural member 100 is removed to form a concave portion 11a.

That is, after friction stir welding is performed by attaching the friction stir tool Tf to the main shaft of a machine tool for machining such as a machining center, machining is performed by replacing the cutting tool Tc such as a reamer with the main shaft. According to this, friction stir welding and machining can be performed continuously while the structural member 100 is supported by the base 41. Therefore, the machining process is simplified and the takt time can be shortened, and high-precision machining is possible without causing positional deviation when attaching and detaching the workpiece. Moreover, by performing machining on the structural member 100 restrained by the base 41, stress in the structural member 100 is released, so that deformation caused by friction stir welding can be further reduced.

Next, a case will be described in which the extruded material panel 11 described above is a hollow member formed by porthole extrusion.
Porthole extrusion is a method in which two dies, a male die and a female die, are set together and the material (billet) is pressed and extruded.The material is divided and supplied from the male die's entry port, and the female die The chamber formed in combination with is filled. As a result, the divided materials are re-integrated (solid phase welding) under pressure and plastic deformation to form a hollow material. A welded portion having a bonding interface between the materials formed by extrusion molding described above is formed at the integrated joint.

FIG. 15 is a partially enlarged sectional view of a structural member in which the edges of extruded material panels are friction stir welded together. A welded portion is formed in a part of the extruded material panel 11 formed by porthole extrusion. When the welded portion is formed, for example, at the edge of the structural member 100 that becomes the joint portion 31, the interface of the welded portion is located at an intermediate position in the thickness direction at the edge of each extruded material panel 11, as shown in FIG. Produces WL. Since the interface WL of this welded part becomes a discontinuous part with respect to the base material, if plastic deformation occurs again at the interface and around the interface, there is a high possibility that an unexpected incomplete part will be formed. Therefore, forming friction stir welding across the interface WL of the welded portion should be avoided.

Therefore, when friction stir welding is performed from the front side of the extruded material panel 11 and when friction stir welding is performed from the back side, the depth is kept within a range that does not reach the depth position of the interface WL of the welded portion. That is, with respect to the thickness direction of the extruded material panel 11, the first stirring joint 33 is formed in the range from the front surface 11b of the extruded material panel 11 to the interface WL of the welded part, and from the back surface 11c to the interface WL of the welded part. A second stirring joint portion 35 is formed in the range up to WL. In this way, both the first stirring joint part 33 and the second stirring joint part 35 are formed without straddling the welded part.

According to this structural member 100, the first stirred joint part 33 and the second stirred joint part 35 are formed without deforming the interface WL of the welded part, so that the welded part which is a discontinuous part is not plastically deformed. Therefore, the occurrence of incomplete bonding (voids) and cracks can be suppressed.

The above-described welded portion can be formed at any position during the design stage of the extruded material panel 11. Therefore, if the position of the joint portion 31 is determined in advance, the design may be such that the joint portion 31 is not formed with a welded portion. Furthermore, if the position of the welded portion has been determined, the portion that will become the joint portion 31 may be determined while avoiding the welded portion. Further, the position of the welded portion and the position of the joint portion 31 may be adjusted together to prevent mutual interference.

For such porthole extrusion, stable processing is possible by using, for example, JIS 1000 series aluminum, 3000 series, and 6000 series aluminum alloys.

FIG. 16 is a photograph of a cross section when friction stir welding is performed from one surface of an extruded material panel to an area beyond the welded part. In FIG. 16, friction stir welding is performed from the back side (lower side) of the extruded material panel 11 toward the front side (upper side). In this case, the welded portion is pushed up toward the surface side, and the interface WL of the welded portion is stirred and decomposed, creating a void VD.

FIG. 17 is a photograph of a cross section when friction stir welding is performed on both sides of an extruded material panel within a range not exceeding the welded portion. In FIG. 17, friction stir welding is performed from the back side (lower side) and the front side (upper side) of the extruded material panel 11, both of which are kept within a range that does not exceed the interface WL of the welded part. As a result, the interface WL of the welded portion was not deformed and no defects were observed.

As described above, the present invention is not limited to the embodiments described above, and those skilled in the art can combine the configurations of the embodiments with each other, modify and apply them based on the description of the specification and well-known techniques. It is also contemplated by the present invention to do so, and is within the scope for which protection is sought.

For example, in the above configuration example, the structural member 100 in which two extruded panels 11 are joined together and the manufacturing method thereof are described, but the number of extruded panels 11 to be joined is not limited to two, but may be three or more. Good too. In that case, structural members of various shapes can be easily manufactured.

Further, the arrangement of the extruded material panel 11 and the base 41 is not limited to the above-described horizontal arrangement, but may be arranged vertically or at an angle depending on the form of the processing apparatus. In that case, the size of the extruded material panel 11 that can be processed can be increased.

Furthermore, the support surface of the base 41 that supports the extruded material panel 11 is not limited to a smooth surface. The support surface may be a surface that supports the extruded material panel 11 at a plurality of contact surfaces, such as a structure in which grooves are formed on a plane and a contact surface consisting of a plurality of convex portions, or a large number of contact points. good. In that case, even if a large contact area is required, the support surface can be formed at low cost.

As mentioned above, the following matters are disclosed in this specification.
(1) A structural member having a plurality of extruded material panels, at least one of which has a plurality of rows of hollow sections along the extrusion direction, and a joint portion in which the edges of the extruded material panels are butted and friction stir welded. There it is,
The joint portion is
The total thickness of the extruded material panel in the thickness direction is 15 mm or less,
a first stirring joint formed on the front side of the extruded material panel;
a second stirring joint formed on the back side of the extruded material panel;
Shoulder stirring surfaces formed along the edges on the front side and the back side of the extruded material panel, respectively;
has
The length in the width direction perpendicular to the longitudinal direction and the thickness direction of the shoulder stirring surface is Wtf, and the length in the width direction of a rib formed between the adjacent hollow parts in the extruded material panel. When Wr is
The length L in the width direction from the edge of the extruded material panel to the edge-side end of the hollow portion located closest to the edge is:
L≧Wtf/2+Wr
A structural member that is
According to this structural member, the extruded material panels are joined with well-balanced and stable joint strength on the front and back sides in the joint having the first friction stir joint on the front side and the second friction stir joint on the back side. We can provide high quality structural members. In addition, the joint part has a total wall thickness of 15 mm or less, and the edge of the extruded material panel having a hollow part on the joint part side is equal to half the width of the shoulder stirring surface and the thickness of the rib between the hollow parts. It has a solid part with a length dimension greater than the total dimension. Therefore, a structural member with sufficient strength at the joint and its surroundings can be obtained.

(2) The structural member according to (1), wherein the first stirring joint portion and the second stirring joint portion each have a thickness of 2 mm or more and 5 mm or less in the thickness direction.
According to this structural member, since the thickness of the first friction stir welded portion and the second friction stir welded portion is set to be 2 mm or more and 5 mm or less, sufficient bonding strength at the joint portion can be ensured on the front and back sides.

(3) The structural member according to (1), wherein the rib has a thickness that is half or more of the thickness of the hollow portion in the thickness direction.
According to this structural member, since the thickness of the rib is at least half the thickness of the hollow portion, sufficient strength of the extruded material panel itself having the hollow portion can be ensured.

(4) The extruded material panel is a hollow shaped member in which a welded part having a bonding interface between materials formed by extrusion molding is formed in a part of the thickness direction,
Regarding the thickness direction, the first stirring joint is formed in a range from the front side surface of the extruded material panel to the interface of the welded part, and the range from the back side surface to the interface of the welded part. (1) to (3), wherein the second stirred joint is formed, and the first stirred joint and the second stirred joint are formed without spanning the interface of the welded part. The structural member according to any one of the above.
According to this structural member, the first stirred joint part and the second stirred joint part are formed without deforming the welded part, so the welded part which is a discontinuous part is not plastically deformed, and there are no incompletely joined parts. (voids) and cracks can be suppressed.

(5) The structural member according to (4), wherein the extruded material panel is made of aluminum or an aluminum alloy.
According to this structural member, a hollow shaped member can be stably formed by porthole extrusion.

(6) A method for manufacturing a structural member in which a plurality of extruded panels, at least one of which has a plurality of rows of hollow portions along the extrusion direction, are friction stir welded by butting the edges of the extruded panels together,
a first arrangement step of arranging the plurality of extruded material panels in a flat manner on a base;
a first pressing step in which the extruded material panels are pressed in a direction in which they approach each other within the plane in which the extruded material panels are arranged in a flat shape, and the edges are brought into contact with each other;
a first pressing step of bringing a pressing jig into contact with the extruded material panel from the other side of the base with the extruded material panel sandwiched therebetween, and pressing the extruded material panel against the base;
A first joining step of performing friction stir welding from one side of the extruded material panel on the holding jig side along the joining line between the edges of the plurality of extruded material panels butted against each other;
a second placement step of retracting the holding jig from the extruded material panel whose one side is friction stir welded, and reversing the extruded material panel and placing it on the base again;
a second pressing step of pressing the extruded material panels in a direction closer to each other within the plane to butt the ends;
a second pressing step of bringing the pressing jig into contact with the extruded material panel again from the other side of the base across the extruded material panel, and pressing the extruded material panel against the base;
a second joining step of performing friction stir welding from one side of the extruded material panel on the holding jig side along the joining line;
A method for manufacturing a structural member, including:
According to this manufacturing method for structural members, when performing friction stir welding, the extruded panels are pressed in a direction toward each other and the extruded panels are pressed against the base, so it is possible to suppress warpage that occurs at the joint location. can. Furthermore, by performing friction stir welding from the front and back sides, it is possible to offset the warpage that occurs at the joining location. As a result, a high-quality structural member in which extruded material panels are joined to each other with suppressed warpage can be obtained.

(7) The pressing jig is provided to extend in the longitudinal direction of the hollow portion of the extruded material panel, and in the first pressing step and the second pressing step, the holding jig is provided to extend in the longitudinal direction of the hollow portion of the extruded material panel, and in the first pressing step and the second pressing step, The method for manufacturing a structural member according to (6), wherein the ribs formed between the extruded material panels are arranged so as to overlap in the thickness direction of the extruded material panel.
According to this method of manufacturing a structural member, it is possible to suppress deformation of the extruded material panel when the extruded material panel is pressed against the base using the pressing jig.

(8) In the first pressing step and the second pressing step, the extruded material panel is pressed against the base over the entire length of the joining line of the friction stir welding by the holding jig, according to (6) or (7). A method for manufacturing a structural member.
According to this method of manufacturing a structural member, since the extruded material panels are pressed over the entire length in the joining direction using the pressing jig, the extruded material panels can be bonded well over the entire length.

(9) The extruded material panel is a hollow shaped member in which a welded part having a bonding interface between materials formed by extrusion molding is formed in a part of the thickness direction,
With respect to the thickness direction of the extruded material panel, a first stirring joint is formed in the range from one surface of the extruded material panel to the interface of the welded portion by the first joining step, and forming a second stirred joint by the second joining step in a range from the surface to the interface of the welded part, and connect the first stirred joint and the second stirred joint without straddling the interface of the welded part; The method for manufacturing a structural member according to any one of (6) to (8), wherein the structural member is formed as follows.
According to this method of manufacturing a structural member, the first stirred joint and the second stirred joint are formed without deforming the weld, so the weld, which is a discontinuous part, is not plastically deformed and the weld is joined. The occurrence of imperfections (voids) and cracks can be suppressed.

(10) The method for manufacturing a structural member according to any one of (6) to (9), wherein the extruded material panel is subjected to machining after the second joining step.
According to this method of manufacturing a structural member, after performing friction stir welding by attaching a friction stir tool to a machine tool for machining such as a machining center, machining can be easily performed by replacing a cutting tool such as a reamer. Can be done.

11 Extruded material panel 11a Concave portion 11b Front surface 11c Back surface 13A, 13B, 13C Hollow portion 15 Rib 17 Solid portion 31 Joint portion 33 First stirring joint 35 Second stirring joint 37 Shoulder stirring surface 41 Base 43 Smooth surface 47, 49 Pressing rib (pressing jig)
47a, 49a Plane part 100 Structural member D1 Depth of first stirred joint D2 Depth of second stirred joint L Width of solid part T2 Thickness of hollow part T3 Total wall thickness Tr Width of rib Tc Cutting tool Tf Friction stirring tool Wtf Width of shoulder stirring surface WL Interface of welded part Wr Width of rib

Claims (5)

A structural member having a plurality of extruded material panels, at least one of which has a plurality of rows of hollow portions along the extrusion direction, and a joint portion in which edges of the extruded material panels are butted and friction stir welded,
The joint portion is
The total thickness of the extruded material panel in the thickness direction is 15 mm or less,
a first stirring joint formed on the front side of the extruded material panel;
a second stirring joint formed on the back side of the extruded material panel;
Shoulder stirring surfaces formed along the edges on the front side and the back side of the extruded material panel, respectively;
has
The extruded material panel is a hollow shaped member in which a welded part having a bonding interface between materials by extrusion molding is formed in a part of the thickness direction,
Regarding the thickness direction, the first stirring joint is formed in a range from the front side surface of the extruded material panel to the interface of the welded part, and the range from the back side surface to the interface of the welded part. The second stirred joint is formed in the weld, and the first stirred joint and the second stirred joint are formed without spanning the interface of the welded part.
Structural members. The first stirring joint part and the second stirring joint part each have a thickness of 2 mm or more and 5 mm or less in the thickness direction,
A structural member according to claim 1. A length of a rib formed between adjacent hollow parts in the extruded material panel in a width direction perpendicular to the extrusion direction and the thickness direction is at least half the thickness of the hollow part. ,
A structural member according to claim 1 or 2. 3. The structural member according to claim 1, wherein at least one of the structural members has a concave portion in which the hollow portion is exposed by removing a portion of one side. 4. The structural member according to claim 3, wherein at least one of the structural members has a concave portion in which a portion of one side of the structural member is removed to expose the hollow portion.

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