JP7428589B2 - How to join structural members - Google Patents

Description

The present invention relates to a method for joining structural members.

In recent years, the development of electric vehicles (including electric vehicles, hybrid vehicles, etc.) has progressed. A battery system mounted on such a vehicle generally has a configuration in which a large number of batteries (batteries, battery cells) are housed in a member made of a predetermined frame or the like.

Patent Document 1 discloses that a plurality of vehicle body frame members are arranged in a row in the horizontal direction of a vehicle and constitute a part of the lower frame of the vehicle body, each of which includes a plurality of battery cells, and each of which includes a plurality of vehicle body members. A battery mounting structure is disclosed that includes a plurality of battery stacks that are restrained to a vehicle body by being sandwiched between frame members directly or via separate members.

Patent Document 2 discloses an automobile tray component that includes a tray base plate and a mounting beam disposed around the tray base plate, and is capable of mounting a power battery, the tray base plate having an upper plate portion, a middle plate portion, and a lower plate portion. A configuration is disclosed including a plate portion, a cooling cavity disposed between an upper plate portion and a middle plate portion, and a buffer cavity disposed between the middle plate portion and the lower plate portion.

JP2018-202946A Special Publication No. 2019-531955

Incidentally, it is desired that the structure housing the battery described in Patent Documents 1 and 2 be manufactured by joining structural members such as extruded materials or plate materials with high precision, but in the current technology, structural members It was difficult to join with high precision due to distortion of the material itself.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for joining structural members that can join structural members with high precision.

The present invention consists of the following configuration.
a flange forming step of forming a flange on the welded surface of the first structural member by applying friction stirring to the welded surface;
Positioning a second structural member relative to the first structural member so that at least a portion of the second structural member is in contact with the flange while facing the modified portion formed on the surface to be joined by the friction stirring process. process and
a joining step of joining the second structural member to the first structural member using the flange as a joining material;
including,
Method of joining structural members.

According to the method for joining structural members of the present invention, structural members can be joined with high precision.

1 is a perspective view of a battery tray manufactured by a bonding method according to an embodiment of the present invention. FIG. 3 is a perspective view of the frame assembly and floor panel that constitute the battery tray. FIG. 3 is a perspective view illustrating a jig placement step in a method of joining side members and cross members that constitute a frame assembly. FIG. 2 is a diagram illustrating each step in a method for joining a cross member to a side member, in which (A) is a plan view of the side member showing a flange forming process, and (B) is a cross-sectional view of the cross member showing a positioning process. (C) is a plan view of the side member in which the cross member is viewed in cross section, showing the joining process. 4A is a cross-sectional view taken along line AA in FIG. 4A, and FIG. 4B is a BB cross-sectional view taken in FIG. 4B. The cross-sectional view (C) is a CC cross-sectional view in (C) of FIG. FIG. 3 is a sectional view of a positioning location showing a positioning state of an end of a cross member with respect to a surface to be joined of a side member. FIG. 3 is a sectional view of a positioning location showing a positioning state of an end of a cross member with respect to a surface to be joined of a side member. It is a perspective view showing a friction stir processing device used in a flange forming process. FIG. 2 is a perspective view of the friction stirring processing device as seen from the tip side. FIG. 2 is a cross-sectional view along the axial direction of the friction stir processing device. It is a perspective view explaining the jig arrangement process in the joining method of a frame assembly and a floor panel. FIG. 2 is a diagram illustrating each step in a method for joining a floor panel to a frame assembly, in which (A) is a sectional view of the frame assembly showing a flange forming process, and (B) is a sectional view of the frame assembly and floor panel showing a positioning process. (C) is a cross-sectional view of the positioning location of the frame assembly and the floor panel, showing the joining process. FIG. 3 is a diagram illustrating another example of joining the floor panel to the frame assembly, in which (A) is a sectional view of the frame assembly showing a flange forming process, and (B) is a sectional view of the frame assembly and floor panel showing a positioning process. (C) is a cross-sectional view of the positioning location, and (C) is a cross-sectional view of the joint location of the frame assembly and floor panel showing the joining process. FIG. 3 is a diagram illustrating another example of joining the floor panel to the frame assembly, in which (A) is a sectional view of the frame assembly showing a flange forming process, and (B) is a sectional view of the frame assembly and floor panel showing a positioning process. (C) is a cross-sectional view of the positioning location, and (C) is a cross-sectional view of the joint location of the frame assembly and floor panel showing the joining process. FIG. 7 is a cross-sectional view of the positioning location of the cross member relative to the side member, explaining Reference Example 1; FIG. 7 is a cross-sectional view of the positioning location of the floor panel with respect to the frame assembly for explaining Reference Example 2; FIG. 3 is a diagram showing a pattern of friction stirring processing applied to a side member, and (A) to (K) are schematic plan views of side members each subjected to friction stirring processing.

Embodiments of the present invention will be described in detail below with reference to the drawings.
FIG. 1 is a perspective view of a battery tray manufactured by a bonding method according to an embodiment of the present invention. FIG. 2 is a perspective view of the frame assembly and floor panel that constitute the battery tray.

As shown in FIGS. 1 and 2, the method for joining structural members according to this embodiment is employed, for example, when manufacturing a structure such as a battery tray 1 for use in a vehicle. The battery tray 1 is capable of storing a plurality of batteries, and is disposed under the floor of the vehicle body of a vehicle (including an electric vehicle, a hybrid vehicle, etc.) driven by electric power, and is fixed to the vehicle body.

The battery tray 1 includes a frame assembly 3 forming an outer frame and a floor panel 5 forming a bottom surface. The battery tray 1 is attached to the vehicle body with the floor panel 5 disposed on the lower side. A plurality of batteries (not shown) are housed in the battery tray 1 in a space surrounded by the frame assembly 3 on the back side of the floor panel 5.

The frame assembly 3 includes a side member (structural member) 10 and a cross member (structural member) 20. The side members 10 are arranged parallel to each other and spaced apart from each other. Both ends of the cross member 20 are joined to one side of each side member 10.

The side members 10 and the cross member 20 are members molded by extrusion molding. Specifically, the side members 10 and the cross member 20 are constructed from hollow extruded sections made of aluminum or aluminum alloy and having a rectangular hollow cross section with a thickness of about 2 to 5 mm. Vertical ribs may be formed inside the hollow cross sections of these side members 10 and cross members 20.

The types of aluminum alloys used for the side members 10 and cross members 20 are aluminum alloys such as 5000 series, 6000 series, and 7000 series as defined by JIS or AA because they have excellent strength and can be made thinner. Applicable. These hollow extruded aluminum alloy sections are manufactured by appropriately combining casting (DC casting method or continuous casting method), homogenization heat treatment, hot extrusion, solution treatment and quenching treatment, and if necessary artificial aging treatment. Manufactured. By manufacturing the side members 10 and cross members 20 by extrusion molding of an aluminum alloy, weight reduction can be achieved.

The floor panel 5 is a member that constitutes the bottom surface of the battery tray 1, and is a plate material made of aluminum, aluminum alloy, or the like. The floor panel 5 has a peripheral edge portion joined to a side surface of a side member 10 constituting the frame assembly 3 and a side surface of a cross member 20 disposed on the outside.

Next, a method for joining structural members according to this embodiment will be explained.
First, a case where the cross member 20 is joined to the side member 10 will be described.
FIG. 3 is a perspective view illustrating a jig placement step in a method for joining side members and cross members that constitute a frame assembly. 4 and 5 are diagrams illustrating each step in the method of joining the cross member to the side member. 6 and 7 are cross-sectional views of positioning points showing the positioning state of the end of the cross member with respect to the surface to be joined of the side member.

(Jig placement process)
As shown in FIG. 3, the side member 10 is placed on a jig 30. The jig 30 is made of stainless steel, for example, and includes a flat plate part 31 and side wall parts 33 provided on both sides of the flat plate part 31. The side members 11 are arranged along both side walls 33 of the jig 30.

(Flange forming process)
As shown in FIGS. 4(A) and 5(A), one side of the side member 10 to which the cross member 20 is to be joined is defined as a joined surface 41, and a flange 43 is formed on this joined surface 41. This flange 43 is formed by performing friction stir processing by friction stir processing (FSP) using a friction stir processing tool 100 at the joining position where the cross member 20 is to be joined on the joined surface 41 of the side member 10. do. Specifically, friction stirring processing is performed by rotating and moving the friction stirring processing tool 100 along the welding position of the cross member 20 on the welded surface 41 of the side member 10. Then, the welded surface 41 of the side member 10 is friction-stirred by the friction-stir processing tool 100 to generate plastic flow and a modified portion 45 is formed, and at the same time, a modified portion 45 is formed on the retreating side of the moving friction-stir processing tool 100. , a flange 43 on which the plastic fluid of the side member 10 is raised is formed.

(Positioning process)
As shown in FIGS. 4(B) and 5(B), the end portion 47 of the cross member 20 is positioned on the joined surface 41 of the side member 10 on which the flange 43 is formed. Specifically, as shown in FIG. 6, the end 47 of the cross member 20 is placed against the surface to be joined 41 of the side member 10, and the flange 43 is brought into contact with the outer peripheral surface of the end 47 of the cross member 20. In this way, the cross member 20 has its end face facing the modified portion 45 formed on the surface to be joined 41 and is positioned by the flange 43 on the surface to be joined 41 of the side member 10 . At this time, the end face of the cross member 20 is brought into contact with the reforming section 45. Note that the flange 43 protrudes from the surface 41 to be joined. Therefore, as shown in FIG. 7, even if the end surface of the cross member 20 is slightly spaced apart from the reforming section 45, it is positioned by the flange 43 abutting the outer peripheral surface.

(Joining process)
As shown in FIGS. 4(C) and 5(C), the corners of the surface 41 to be joined of the side member 10 and the end portion 47 of the cross member 20 are joined. Then, a joint portion 49 is formed at the corner of the joined surface 41 of the side member 10 and the end portion 47 of the cross member 20, and the cross member 20 is firmly joined to the side member 10.

This joining may be performed, for example, by welding using MIG, TIG, or laser, or by friction stir welding (FSW). When joining by welding, the flange 43 becomes a filler metal, and when joining by friction stir welding, the flange 43 becomes a plastic fluid. That is, in any case of joining, the flange 43 is used as a joining material that forms the joining part 49.

Here, the friction stir machining tool 100 suitable for forming the flange 43 will be described.
FIG. 8 is a perspective view showing a state in which a flange is being formed using a friction stir processing tool. FIG. 9 is a perspective view of the friction stir machining tool. FIG. 10 is a cross-sectional view of the friction stir machining tool along the axial direction.

As shown in FIGS. 8 to 10, the friction stir machining tool 100 is used by being attached to a friction stir machining device (not shown). The friction stirring processing tool 100 includes a rotating tool 111 and an abutment block 131.

The rotating tool 111 is formed into a rod shape and is rotated in one rotational direction α. The rotary tool 111 has a main body part 113 and a small diameter pin part 115 formed at the tip of the main body part 113. This pin portion 115 has a spiral protrusion 117 formed on its outer periphery.

Further, the rotary tool 111 has a shoulder portion 121 at the root portion of the pin portion 115 having a small diameter. The shoulder portion 121 is formed to have a smaller diameter than the main body portion 113 and has a larger diameter than the pin portion 115. The surface of the shoulder portion 121 between the shoulder portion 121 and the pin portion 115 is inclined radially outward from the pin portion 115 toward the distal end side. As a result, a recess is formed in the shoulder portion 121 at the root portion of the pin portion 115, and this recess is used as a holding recess 123.

The contact block 131 is formed into a substantially cubic shape. This contact block 131 has an insertion hole 133 penetrating the front and back sides. The rotation tool 111 is inserted into the insertion hole 133 from above the contact block 131. An annular locking portion 135 is formed at the lower edge of the insertion hole 133 and extends in an annular shape toward the inner circumference. The annular locking portion 135 has an inner diameter slightly larger than an outer diameter of the shoulder portion 121 of the rotary tool 111.

The lower surface of the contact block 131 is a contact surface 141, and this contact surface 141 is brought into contact with the surface to be joined 41 when the surface to be joined 41 is processed. One flange forming groove 143 is formed in the abutment surface 141 of the abutment block 131 . This flange forming groove 143 is formed in a straight line. One end of the flange forming groove 143 communicates with one location in the circumferential direction of the insertion hole 133, and the other end reaches one side surface of the contact block 131. This flange forming groove 143 extends in a tangential direction toward the front side of the rotation direction α of the rotary tool 111. Since the flange forming groove 143 communicates with the insertion hole 133, a notch 137 is formed in the annular locking portion 135 at one location in the circumferential direction.

The rotary tool 111 inserted into the insertion hole 133 of the contact block 131 from above has its shoulder portion 121 passed through the inner peripheral side of the annular locking portion 135, and the step between the main body portion 113 and the shoulder portion 121 is inserted into the rotation tool 111 from above. portion is locked by the annular locking portion 135. As a result, the rotary tool 111 is arranged such that the pin part 115 and part of the shoulder part 121 protrude from the contact surface 141 of the contact block 131. This abutment block 131 is fixed to the friction stirring processing apparatus by a fixing means (not shown). As a result, in the friction stirring processing tool 100, only the rotary tool 111 is rotated in the rotation direction α with respect to the fixed abutment block 131.

In order to form the flange 43 on the surface to be welded 41 using the friction stir machining tool 100, first, the rotary tool 111 is moved so that the extending direction of the flange forming groove 143 is tangential to the front side of the rotation direction α. Rotate. Next, the friction stirring processing tool 100 is moved toward the welded surface 41 of the side member 10, and the rotated rotary tool 111 is pressed against the welded surface 41. This causes the pin portion 115 of the rotary tool 111 to bite into the surface to be welded 41, and further brings the abutment surface 141 of the abutment block 131 into contact with the surface to be welded 41.

In this state, the friction stirring processing tool 100 is moved relative to the side member 10 in a direction opposite to the direction in which the flange forming groove 143 extends. Then, the welded surface 41 of the side member 10 is friction-stirred by the friction-stir processing tool 100 to generate plastic flow and a modified portion 45 is formed. , a flange 43 on which the plastic fluid of the side member 10 is raised is formed.

By using this friction stirring processing tool 100, it is possible to easily form a flange 43 having a shape suitable for positioning, for example, at any position in the center of the surface to be joined 41 consisting of the side surface of the side member 10. Therefore, it is possible to increase the degree of freedom in designing a structure such as the frame assembly 3, which is manufactured by positioning and joining the end of the cross member 20 to the flange 43 formed on the surface to be joined 41.

Further, the rotary tool 111 has a spiral protrusion 117 formed on the outer periphery of the pin portion 115. Therefore, the spiral protrusion 117 allows the plastic fluid to flow better, and the flange 43 can be formed more smoothly in the flange forming groove 143.

Furthermore, the rotary tool 111 has a holding recess 123 in the shoulder portion 121 that holds the plastic fluid. As a result, the plastic fluid of the side member 10 that has been plastically fluidized by the pin portion 115 is once held in the holding recess 123 of the shoulder portion 121 and sent out to the flange forming groove 143. Therefore, the plastic fluid can be stably sent to the flange forming groove 143, and the flange 43 having a uniform shape in the longitudinal direction can be formed on the joined surface 41 of the side member 10.

Next, the case where the floor panel 5 is joined to the frame assembly 3 will be explained.
FIG. 11 is a perspective view illustrating a jig placement process in a method for joining a frame assembly and a floor panel. FIG. 12 is a diagram illustrating each step in a method for joining a floor panel to a frame assembly.

(Jig placement process)
As shown in FIG. 11, the frame assembly 3 in which the cross member 20 is joined to the side member 10 is placed on a jig 30. Note that if the floor panel 5 is to be joined subsequent to the fabrication of the frame assembly 3, the frame assembly 3 will be placed on the jig 30.

(Flange forming process)
As shown in FIG. 12(A), the side surface of the outer frame portion made up of the side members 10 and cross members 20 constituting the frame assembly 3 is the surface to be joined 51, and the floor panel 5 on this surface to be joined 51 is joined. The flange 53 is formed at the joining position by applying friction stirring processing using the friction stirring processing tool 100. The joining position in the frame assembly 3 is the inner edge portion of the outer frame portion of the frame assembly 3 consisting of the side members 10 and the cross member 20. That is, friction stirring processing is performed by rotating and moving the friction stirring processing tool 100 along the inner edge portion of this outer frame portion. Then, the welded surface 51 of the frame assembly 3 is friction stirred by the friction stir machining tool 100 and plastic flow is generated to form a modified portion 55, and the retreating side of the moving friction stir machining tool 100 is formed. Then, the flange 53 of the frame assembly 3 having a raised plastic fluid is formed. At this time, the inner side wall 52 of the side member 10 or cross member 20 constituting the frame assembly 3 is placed at a position where the friction stirring processing tool 100 is pressed and pressurized. Therefore, the pressing force from the friction stirring processing tool 100 is received by the side wall 52, and deformation of the welded surface 51 due to pressurization is suppressed. In addition, when vertical ribs are formed inside the hollow cross sections of the side members 10 and cross members 20, the modified portions 55 are formed on the upper portions of the vertical ribs, and a flange is formed on the retreating side of the moving friction stir machining tool 100. 53 may be molded. Also at this time, it is preferable to use the friction stir machining tool 100 having the rotary tool 111 and the contact block 131 described above.

(Positioning process)
As shown in FIG. 12(B), the edge 57 of the floor panel 5 is positioned on the surface 51 to be joined of the frame assembly 3 on which the flange 53 is formed. Specifically, the floor panel 5 is placed on the frame assembly 3, and the edge 57 of the floor panel 5 is brought into contact with the flange 53 toward the surface 51 of the frame assembly 3 to be joined. In this way, the edge 57 of the floor panel 5 faces the modified portion 55 formed on the surface 51 to be joined, and the floor panel 5 is positioned on the surface 51 to be joined of the frame assembly 3 by the flange 53.

(Joining process)
As shown in FIG. 12C, the corners of the surface 51 to be joined of the frame assembly 3 and the edge 57 of the floor panel 5 are joined. Then, a joint 59 is formed at the corner between the surface 51 of the frame assembly 3 to be joined and the edge 57 of the floor panel 5, and the floor panel 5 is firmly joined to the frame assembly 3.

This joining may also be performed by, for example, welding using MIG, TIG, or laser, or by friction stir welding (FSW). When joining by welding, the flange 53 becomes a filler metal, and when joining by friction stir welding, the flange 53 becomes a plastic fluid. That is, in any case of joining, the flange 53 is used as a joining material that forms the joint portion 59. Note that (C) in FIG. 12 shows a cross-sectional shape when joined by welding.

Next, another example of joining the floor panel 5 to the outer frame portion of the frame assembly 3 will be described.
FIGS. 13 and 14 are process diagrams each illustrating another example of joining the floor panel to the frame assembly.

(When the outer edge part of the outer frame part of the frame assembly 3 is the joining position)
As shown in FIG. 13A, the friction stirring processing tool 100 is pressed and moved while rotating against the welded surface 51 consisting of the side surface of the outer frame portion of the frame assembly 3 placed on the jig 30. As a result, the flange 53 is formed along the outer edge of the outer frame portion (flange forming step). At this time, the outer side wall 52 of the side member 10 or cross member 20 constituting the frame assembly 3 is arranged at the outer edge position of the outer frame portion against which the friction stirring processing tool 100 is pressed and pressurized. becomes. Therefore, the pressing force from the friction stirring processing tool 100 is received by the side wall 52, and deformation of the welded surface 51 due to pressurization is suppressed.

Thereafter, as shown in FIG. 13(B), the floor panel 5 is superimposed on the frame assembly 3, and the edge 57 of the floor panel 5 is applied to the surface 51 of the frame assembly 3 to be joined to the flange 53. Bring them into contact (positioning process). Then, as shown in FIG. 13C, the corners of the surface 51 to be joined of the frame assembly 3 and the edge 57 of the floor panel 5 are joined (joining step).

(When vertical ribs are provided inside the hollow sections of the side members 10 and cross members 20)
As shown in FIG. 14A, the friction stirring processing tool 100 is rotated and moved against the welded surface 51, which is the side surface of the outer frame portion of the frame assembly 3 placed on the jig 30. As a result, a flange 53 is formed between the inner edge and outer edge of the outer frame portion (flange forming step). At this time, a vertical rib 54 provided inside the hollow cross sections of the side members 10 and cross members 20 is arranged at an intermediate position between the inner edge and the outer edge against which the friction stirring processing tool 100 is pressed and pressurized. The Rukoto. Therefore, the pressing force from the friction stirring processing tool 100 is received by the vertical ribs 54, and deformation of the welded surface 51 due to pressurization is suppressed. At this time, it is sufficient that at least a portion of the friction stirring processing tool 100 is disposed over the top of the vertical rib 54 so that at least a portion of the modified portion 55 is formed above the vertical rib 54 . The friction stirring processing tool 100 forming the modified portion 55 is preferably disposed over the entire width of the vertical rib 54 at the upper part of the vertical rib 54, and its center position is disposed at the center of the vertical rib 54 in the width direction. It is more preferable to

Thereafter, as shown in FIG. 14(B), the floor panel 5 is superimposed on the frame assembly 3, and the edge 57 of the floor panel 5 is aligned with the surface 51 of the frame assembly 3 to be joined to the flange 53. Bring them into contact (positioning process). Then, as shown in FIG. 14C, the corners of the surface 51 to be joined of the frame assembly 3 and the edge 57 of the floor panel 5 are joined (joining step).

Here, a reference example will be explained.
FIG. 15 is a cross-sectional view of the positioning location of the cross member relative to the side member, explaining Reference Example 1. FIG. 16 is a sectional view of the positioning location of the floor panel with respect to the frame assembly, explaining Reference Example 2.

As shown in FIG. 15, in this reference example 1, a groove 61 is formed in the joined surface 41 of the side member 10, and the end 47 of the cross member 20 is disposed in this groove 61. Then, the outer circumferential surface of the end portion 47 of this cross member 20 is brought into contact with the outer inner surface of the groove portion 61 for positioning.

As shown in FIG. 16, in this second embodiment, a notch 65 is formed in the surface 51 to be joined of the frame assembly 3, and the edge 57 of the floor panel 5 is disposed in the notch 65. Then, the edge 57 of the floor panel 5 is brought into contact with the stepped portion of the notch 65 for positioning.

In both Reference Examples 1 and 2, the groove portion 61 and the notch portion 65 are formed by cutting the surfaces 41 and 51 to be joined. Therefore, the thickness of the surfaces 41, 51 to be joined becomes thinner, resulting in a decrease in strength. Furthermore, in order to suppress a decrease in strength due to thinning of the wall thickness, it is necessary to increase the wall thickness of the side members 10 and the cross member 20 in advance, which increases the weight. Moreover, in these Reference Examples 1 and 2, a filler metal is required when joining by welding in the joining process, resulting in an increase in cost.

As described above, according to the method for joining structural members according to the present embodiment, a flange formed by friction stir processing on the joined surfaces 41 and 51 of the first structural member consisting of the side member 10 and the frame assembly 3 is used. 43 and 53, a second structure consisting of the cross member 20 and the floor panel 5 is brought into contact with, positioned and joined. Thereby, the first structural member and the second structural member can be joined with high precision, and structures such as the frame assembly 3 and the battery tray 1 can be manufactured.

In addition, compared to the case where grooves 61 and notches 65 for positioning are formed on the surfaces 41, 51 to be joined by cutting as in Reference Examples 1 and 2, the surfaces 41, 51 to be joined are thinned and strengthened. It can be joined without causing any deterioration.

Moreover, the toughness of the modified portions 45, 55 of the welded surfaces 41, 51 formed by friction stirring processing is increased. Therefore, by connecting the cross member 20 and the floor panel 5 to the modified portions 45 and 55 so as to face each other, it is possible to suppress damage when an impact is applied. Thereby, a structure with excellent impact resistance can be manufactured.

Furthermore, with the first structural member consisting of the side member 10 and the frame assembly 3 mounted on the jig 30, the flanges 43, 53 are formed on the surfaces 41, 51 to be joined using the friction stirring processing tool 100. Even if one structural member is twisted or distorted, the flanges 43 and 53 can be formed with high precision to improve the accuracy of joining with the second structural member consisting of the cross member 20 and the floor panel 5.

In addition, in the joining process, when welding and joining the first structural member consisting of the side member 10 and the frame assembly 3 to the second structural member consisting of the cross member 20 and the floor panel 5, the positioning flange 43 and 53 can be welded as filler metals. Therefore, welding can be performed easily and at low cost without using a separate filler metal.

Furthermore, in the joining process, in the case where the first structural member consisting of the side member 10 and the frame assembly 3 and the second structural member consisting of the cross member 20 and the floor panel 5 are friction stir welded, the positioning flange 43 , 53 become plastic fluids and are well joined. Furthermore, since the flange forming process and the joining process can be performed by friction stirring processing, the flange forming process and the joining process can be easily performed using the same equipment by simply replacing the friction stirring processing tool.

In the above embodiment, when joining the cross member 20 to the side member 10, the flange 43 is formed by performing friction stirring processing in a rectangular shape across the width direction on the side surface of the side member 10, but the flange 43 is formed by friction stirring processing. are processed in a pattern according to the cross-sectional shape of the cross member 20 to be joined.

Next, the pattern of the friction stirring process when forming the flange 43 on the side member 10 will be explained.
FIG. 17 is a diagram showing a pattern of friction stirring processing on the side member.

FIG. 17A shows a pattern when rectangular cross members 20 having a width smaller than the width of the side members 10 are joined. Friction stir processing is performed using the following pattern.

FIG. 17B shows a pattern for joining a cross-sectional cross member 20 having a plate portion at the center. Friction stirring processing is performed in a sun-shaped pattern having a modified portion 45 and a modification portion 45.

FIG. 17(C) shows a pattern in which the cross member 20 is joined to the side member 10 at an inclination angle of, for example, 45 degrees. Perform stirring processing.

(D) in FIG. 17 is a pattern when joining the cross member 20 having a U-shaped cross-section. In this case, friction stirring processing is performed in a U-shaped pattern according to the cross-sectional shape of the cross member 20. .

(E) of FIG. 17 is a pattern when joining the cross member 20 which has a width dimension smaller than that of the side member 10 and has a U-shaped cross-sectional shape. Friction stirring processing is performed in a U-shaped pattern with a small width dimension in accordance with the cross-sectional shape of No. 20. In this case, the end portion of the cross member 20 having a rectangular cross section may be partially positioned by a flange 34 formed in a U-shaped pattern.

(F) in FIG. 17 is a pattern in which friction stirring processing is performed in parallel to each other in the width direction and longitudinal direction of the side member 10. In this case, the corners of the rectangular portion can be made at right angles, compared to the case where the friction stirring processing tool 100 is continuously processed while changing its orientation.

FIG. 17G shows a pattern in which friction stirring is performed at four locations where the corners of the rectangular cross member 20 are arranged relative to the side member 10. In this way, the end 47 of the cross member 20 may be partially positioned.

(H) in FIG. 17 is a pattern in which friction stirring processing is performed parallel to each other at intervals in the length direction of the side member 10. In this case, both sides of the end 47 of the cross member 20 can be positioned.

17(I) is a pattern in which friction stirring processing is performed in parallel to each other at intervals in the width direction of the side member 10. In this case, the upper and lower portions of the end portion 47 of the cross member 20 can be positioned.

(J) in FIG. 17 shows a pattern when joining the circular cross member 20, and in this case, friction stirring processing is performed in a circular pattern according to the cross-sectional shape of the cross member 20.

(K) in FIG. 17 is a pattern when joining the circular cross member 20, and friction stirring processing is performed in an arc shape along a part of the end portion 47 of the cross member 20. In this case, the circular cross member 20 is partially positioned.

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.

As mentioned above, the following matters are disclosed in this specification.
(1) a flange forming step of forming a flange on the welded surface of the first structural member by applying friction stirring to the welded surface;
Positioning a second structural member relative to the first structural member so that at least a portion of the second structural member is in contact with the flange while facing the modified portion formed on the surface to be joined by the friction stirring process. process and
a joining step of joining the second structural member to the first structural member using the flange as a joining material;
A method for joining structural members, including:

According to this method of joining structural members, the second structural member is brought into contact with the flange formed on the surface to be joined of the first structural member, and the second structural member is positioned and joined. A structure can be manufactured by joining structural members with high precision.
In addition, compared to the case where a positioning groove or notch in which the second structural member is fitted and positioned is formed on the surface of the first structural member to be joined by cutting, the surface to be joined is made thinner. It is possible to join without causing a decrease in strength.
Furthermore, the toughness of the modified portion of the welded surface of the first structural member formed by friction stirring processing is increased. Therefore, by joining the second structural member to the modified portion so as to face each other, damage caused when an impact is applied between the first structural member and the second structural member can be suppressed. Thereby, a structure with excellent impact resistance can be manufactured.

(2) The method for joining structural members according to (1), wherein the first structural member is mounted on a jig in advance in the flange forming step.

According to this method for joining structural members, a flange is formed on the surface of the first structural member to be joined using a friction stir machining tool while the first structural member is mounted on a jig. Even if the member is twisted or distorted, the flange can be formed with high precision and the precision of joining with the second structural member can be increased.

(3) The method for joining structural members according to (1) or (2), wherein in the joining step, the first structural member and the second structural member are joined by welding.

According to this structural member joining method, the first structural member and the second structural member can be joined with high precision by welding. At this time, since the positioning flange can be welded as a filler metal, welding can be performed easily and at low cost without using a separate filler metal.

(4) The method for joining structural members according to (1) or (2), wherein in the joining step, the first structural member and the second structural member are friction stir welded.

According to this structural member joining method, the first structural member and the second structural member can be joined with high precision by friction stirring. At this time, the positioning flange becomes a plastic fluid and is well joined. Further, since the flange forming process and the joining process can be performed by friction stirring processing, the flange forming process and the joining process can be easily performed using the same equipment by simply replacing the friction stirring processing tool.

(5) The first structural member and the second structural member are each extruded materials,
The flange is formed using the side surface of the first structural member made of the extruded material as the surface to be joined, and the end of the second structural member made of the extruded material is positioned by abutting against the flange. The method for joining structural members according to any one of (1) to (4), wherein the structural members are joined.

According to this structural member joining method, the end portion of a second structural member made of an extruded material is joined to the side surface of a first structural member made of an extruded material, for example, a structure such as an outer frame constituting a battery tray. The body can be manufactured easily and with high precision.

(6) The first structural member is an extruded material, and the second structural member is a face plate,
The flange is formed using the side surface of the first structural member made of the extruded material as the surface to be joined, and the edge of the second structural member made of the face plate is brought into contact with the flange and positioned and joined. The method for joining structural members according to any one of (1) to (4).

According to this method of joining structural members, the edge of a second structural member made of a face plate is joined to the side surface of a first structural member made of an extruded material, such as a battery tray with a panel joined to an outer frame. structure can be manufactured easily and with high precision.

(7) A friction stir processing tool for forming the flange on the surface to be joined in the flange forming step,
a rotary tool that is pressed by the surface to be joined and moved along the surface to be joined, thereby frictionally stirring the first structural member along the moving direction;
an abutment block having an insertion hole through which the rotary tool is inserted, abutting the surface to be joined and moving in the moving direction together with the rotary tool;
Equipped with
The rotary tool is
A small diameter pin part provided at the tip,
a shoulder portion provided at the root of the pin portion and configured to send out a plastic fluid generated from the welded surface that is friction stirred by the pin portion and flows plastically to an outer peripheral side;
has
The abutment block is
a contact surface that contacts the surface to be joined;
one flange forming groove formed on the abutment surface, communicating with one location in the circumferential direction of the insertion hole and extending in a tangential direction toward the front side in the rotational direction of the rotary tool;
The method for joining structural members according to any one of (1) to (6), comprising:

According to this method for joining structural members, the contact surface of the contact block of the friction stir processing tool is brought into contact with the surface to be joined, and the rotated rotary tool is pressed against the surface to be joined to cause the pin portion to bite. Then, the friction stirring processing tool is moved relative to the surface to be joined in a direction opposite to the direction in which the flange forming groove extends. Thereby, a flange having a shape suitable for positioning can be easily formed at an arbitrary position in the central portion of the surfaces to be joined. Therefore, the degree of freedom in designing a structure produced by positioning and joining the second structural member to the flange formed on the surface to be joined can be increased.

3 Frame assembly (first structural member)
5 Floor panel (second structural member)
10 Side member (first structural member)
20 Cross member (second structural member)
30 Jig 41, 51 Surface to be joined 43, 53 Flange 45, 55 Modified part 100 Friction stirring tool 111 Rotary tool 115 Pin part 121 Shoulder part 131 Contact block 133 Insertion hole 141 Contact surface 143 Flange forming groove α rotation Direction

Claims (7)

A flange forming step of forming a flange along the welded surface of the first structural member by performing friction stirring processing in which a friction stir processing tool is rotated and moved along the welded surface;
a flange forming step of forming a flange on the welded surface of the first structural member by applying friction stirring to the welded surface;
Positioning a second structural member relative to the first structural member so that at least a portion of the second structural member is in contact with the flange while facing the modified portion formed on the surface to be joined by the friction stirring process. process and
a joining step of joining the second structural member to the first structural member using the flange as a joining material;
including,
Method of joining structural members. In the flange forming step, the first structural member is mounted on a jig in advance;
The method for joining structural members according to claim 1. In the joining step, the first structural member and the second structural member are welded and joined;
A method for joining structural members according to claim 1 or 2. In the joining step, the first structural member and the second structural member are friction stir welded;
A method for joining structural members according to claim 1 or 2. The first structural member and the second structural member are each extruded materials,
The flange is formed using the side surface of the first structural member made of the extruded material as the surface to be joined, and the end of the second structural member made of the extruded material is positioned by abutting against the flange. to join,
The method for joining structural members according to any one of claims 1 to 4. The first structural member is an extruded material, the second structural member is a face plate,
The flange is formed using the side surface of the first structural member made of the extruded material as the surface to be joined, and the edge of the second structural member made of the face plate is brought into contact with the flange and positioned and joined. let,
The method for joining structural members according to any one of claims 1 to 4. The friction stir processing tool for forming the flange on the surface to be joined in the flange forming step,
a rotary tool that is pressed by the surface to be joined and moved along the surface to be joined, thereby frictionally stirring the first structural member along the moving direction;
an abutment block having an insertion hole through which the rotary tool is inserted, abutting the surface to be joined and moving in the moving direction together with the rotary tool;
Equipped with
The rotary tool is
A small diameter pin part provided at the tip,
a shoulder portion provided at the root of the pin portion and configured to send out a plastic fluid generated from the welded surface that is friction stirred by the pin portion and flows plastically to an outer peripheral side;
has
The abutment block is
a contact surface that contacts the surface to be joined;
one flange forming groove formed on the abutment surface, communicating with one location in the circumferential direction of the insertion hole and extending in a tangential direction toward the front side in the rotational direction of the rotary tool;
has,
A method for joining structural members according to any one of claims 1 to 6.

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