Body frame parts

Abstract

Provided is a vehicle framework component (10) that can be reduced in weight. The vehicle framework component comprises: a metal first member (20) that includes a body (21) and a plate-like rib (22) protruding from the body; a metal second member (30) that includes a plate-like end part (31); and a joining member (40) that, in a state in which the rib and the end part are overlapped, penetrates the rib and / or the end part at a portion where the rib and the end part overlap, and mechanically joins the rib and the end part. The rib comprises: a root (22a) connected to the body; and a joint (22c) in which the plate thickness decreases with an increase in distance from the root side toward a distal end (22b) on the other side and in which the joining member is disposed. A joint center line (L1) passing through the centroid of the joint intersects an end-part center line (L2) passing through the centroid of the end part.

Description

Technical Field

[0001] The present invention relates to a vehicle body skeleton component that supports a vehicle body. Background Art

[0002] In members constituting a vehicle body, a joining structure is known in which a plate-shaped metallic first plate material and a plate-shaped metallic second plate material are mechanically joined by a joining member (self-piercing rivet) in a state where they are overlapped in the plate thickness direction. Patent Document 1 discloses a prior art in which the joining member penetrates the first plate material in a state where inclined surfaces (joining surfaces) provided on both the first plate material and the second plate material are in contact with each other, and non-joining surfaces located on the opposite side of the inclined surfaces are parallel to each other. Prior Art Documents Patent Documents

[0003] Patent Document 1 Japanese Unexamined Patent Publication No. 2016-142296 Summary of Invention Problems to be Solved by the Invention

[0004] The prior art has a problem that the non-joining surfaces on the opposite side of the inclined surfaces are parallel to each other, and the main body portion connected to the joint portion where the joining member is arranged is thicker than the joint portion, which hinders weight reduction.

[0005] The present invention has been made to solve this problem, and an object thereof is to provide a vehicle body skeleton component that can achieve weight reduction. Means for Solving the Problems

[0006] To achieve this objective, a first aspect of the present invention provides a vehicle body frame component comprising: a first metal member including a main body and a plate-shaped rib protruding from the main body; a second metal member including a plate-shaped end; and a joining member for mechanically joining the rib and the end in a state where the rib and the end are overlapped, wherein the rib comprises a root connected to the main body and a joint portion where the plate thickness decreases from the root side toward the opposite tip side and where the joining member is positioned, and the center line of the joint portion passing through the centroid of the joint portion intersects the center line of the end portion passing through the centroid of the end.

[0007] A second aspect is that, in the first aspect, the joining member comprises a shaft portion and a head portion to which the base of the shaft portion is connected, wherein the shaft portion at least penetrates the end portion, the tip portion of the shaft portion is located within the joining portion in a manner that is flared out relative to the base of the shaft portion, and the angle between the center line of the joining portion and the center line of the end portion is 1.5° or less.

[0008] In the third embodiment, in the second embodiment, in a cross-section obtained by cutting with a plane that includes the center line of the joining member and is aligned with the direction in which the plate thickness of the joining portion decreases, the distance between the outer surface of the root of the shaft portion and the tip of the shaft portion in the direction in which the end center line extends is longer on the tip side of the rib than on the root side of the rib, and the distance between the root of the shaft portion and the tip of the shaft portion in the direction perpendicular to the end center line is longer on the root side of the rib than on the tip side of the rib. [Effects of the Invention]

[0009] According to the first embodiment, the center line of the joint passing through the centroid of the joint intersects with the center line of the end passing through the centroid of the end, so the thickness of the second member can be reduced compared to the prior art. As a result, the weight of the vehicle body frame component can be reduced.

[0010] According to the second embodiment, the shaft portion penetrates at least the end portion, the tip of the shaft portion is positioned within the joint portion in a state that spreads out relative to the base of the shaft portion, and furthermore, the center line of the joint portion passing through the centroid of the joint portion intersects with the center line of the end portion passing through the centroid of the end portion. As a result, the first member and the second member can be joined in a state where the joining member (shaft portion) is positioned along the direction in which the first member extends. Consequently, compared to the case where the center line of the joint portion passing through the centroid of the joint portion is parallel to the center line of the end portion passing through the centroid of the end portion, the amount to which the tip of the shaft portion is positioned within the joint portion in the direction in which the first member extends can be increased. Therefore, the joint strength against the direction in which the joining member comes out can be improved.

[0011] Furthermore, since the angle between the center line of the joint and the center line of the end is 1.5° or less, it is difficult to create a gap between the head of the joint member and the upper surface of the second member (end). This makes it easier to secure the length over which the shaft is joined to the first and second members. As a result, a decrease in joint strength can be suppressed. Therefore, the joint strength of the first and second members can be secured against the direction in which the joint member comes loose.

[0012] According to the third embodiment, in a cross-section cut by a plane containing the center line of the joining member and along the direction in which the plate thickness of the joining portion decreases, the distance between the outer surface of the root of the shaft portion and the tip of the shaft portion in the direction in which the end center line extends is longer on the tip side of the rib than on the root side of the rib, and the distance between the root of the shaft portion and the tip of the shaft portion in the direction perpendicular to the end center line is longer on the root side of the rib than on the tip side of the rib. Therefore, the shaft portion extends long in the vertical direction relative to the thicker portion of the first member and extends horizontally along the thinner portion of the first member, allowing the first member (joint portion) and the second member (end) to be joined. As a result, the joining area of ​​the first member and the second member with respect to the joining member can be secured. Thus, the joining strength of the first member and the second member in the direction in which the joining member comes loose can be improved. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic perspective view of a vehicle body frame component in one embodiment. [Figure 2]This is a longitudinal cross-sectional view of the vehicle body frame components along line II-II in Figure 1. [Figure 3] (a) is a partial cross-sectional view of a vehicle frame component before it is joined by a connecting member, and (b) is a partial cross-sectional view of a vehicle frame component after it has been joined by a connecting member. [Figure 4] This is a longitudinal cross-sectional view of the test specimen in the embodiment. [Modes for carrying out the invention]

[0014] Hereinafter, preferred embodiments of the present invention will be described with reference to Figure 1. Figure 1 is a schematic perspective view of a vehicle body frame component 10 in one embodiment. In Figure 1, the arrows U, D, F, B, L, and R directions are described as the upward, downward, forward, rearward, leftward, and rightward directions of the vehicle, respectively (the same applies in Figures 2 and 3). The vehicle body frame component 10 is a component that supports the vehicle body, excluding the power system such as the engine and motor, the drive system such as the transmission and gears, the running system such as the chassis, and auxiliary equipment components.

[0015] As shown in Figure 1, in this embodiment, the vehicle body frame component 10 is, as an example, a component on the rear side of the vehicle, where the first member 20 is the rear frame and the second member 30 is a floor member joined to the rear frame.

[0016] The vehicle body frame component 10 comprises a pair of left and right first members 20, and a second member 30 positioned between the pair of first members 20, with both ends in the width direction joined to each of the first members 20. The second member 30 is joined to the first members 20 by a plurality of joining members 40. The vehicle body frame component 10 may or may not be symmetrical. Furthermore, the left first member 20 and the right first member 20 of the vehicle body frame component 10 may have different shapes.

[0017] The material of the first member 20 and the material of the second member 30 are not limited as long as they are metallic. For example, steel-based materials, aluminum-based materials, or magnesium-based materials may be adopted. Further, the first member 20 and the second member 30 may be made of the same material, or may be made of different materials. In the present embodiment, a material having a higher specific gravity than the material of the first member 20 is adopted as the material of the second member 30. Note that a material having a lower specific gravity than the material of the first member 20 or a material having the same specific gravity may also be adopted as the material of the second member 30.

[0018] With reference to Figure 2, the joining structure of the first member 20 and the second member 30 of the vehicle body skeleton component 10 in the present embodiment will be described. Figure 2 is a longitudinal cross-sectional view of the vehicle body skeleton component 10 taken along line II-II in Figure 1. In Figure 2, the left side of the vehicle body skeleton component 10 is omitted from illustration (the same applies to Figure 3). In Figure 2, the lower side of the C-shaped cross-section main body 21 on the right side of the vehicle body skeleton component 10 is also omitted from illustration.

[0019] As shown in Figure 2, the first member 20 is a member made of aluminum alloy, and includes a plate-shaped main body 21 that is bent and has a C-shaped cross section opening to the vehicle outer side, and a rib 22 that stands upright from one surface 21a which is the surface of the main body 21 facing the vehicle inner side. Vehicle undercarriage components (not shown) such as a suspension tower and a tire are connected to the other surface 21b side which is the surface of the main body 21 facing the vehicle outer side. The main body 21 has improved strength by being provided with the rib 22. Note that ribs other than the rib 22 may be provided on the main body 21 as necessary. The shape of the main body 21 can be freely changed according to the shape of the vehicle body.

[0020] The first member 20 is manufactured by die casting using a fixed mold and a movable mold that is movable relative to the fixed mold. That is, the first member 20 is formed by filling a cavity formed between the fixed mold and the movable mold with a molten aluminum alloy, and pressurizing the molten metal to form a molded product (the first member 20). At this time, one surface 21a of the main body 21 of the first member 20 is in contact with the cavity surface of the fixed mold, and the other surface 21b is in contact with the cavity surface of the movable mold. After pressurization, the movable mold retreats relative to the fixed mold, and the molded first member 20 is demolded from the movable mold. In order to improve demoldability, the rib 22 of the first member 20 is provided with a draft angle of 1.5° on the upper surface and -1.5° on the lower surface with respect to the moving direction of the movable mold (the mold release direction). The draft angles of the upper surface and the lower surface of the rib 22 may be other angles than these.

[0021] The draft angles of the upper surface and the lower surface of the rib 22 are preferably set to 1.5° or less and -1.5° or less. In this case, the plate thickness at the root 22a of the rib 22 can be easily set to be thin. As a result, the weight of the rib 22 can be reduced. In the present embodiment, the plate thickness of the rib 22 is set to 3 to 5 mm, and the plate thickness of the end portion 31 is set to 1.5 mm.

[0022] The rib 22 includes a root 22a connected to the main body 21, and a joint portion 22c whose plate thickness decreases from the root 22a side toward the tip 22b side. The joint portion 22c is a portion that is joined to the end portion 31 of the second member 30, which will be described later in an overlapped state. The joint portion 22c is formed with a raised portion 22f that protrudes from the non-joint surface 22e. In the present embodiment, a portion obtained by extending the root 22a toward the tip 22b side is defined as the joint portion 22c. In the raised portion 22f, the step difference with the non-joint surface 22e on the side where the plate thickness of the joint portion 22c is reduced is set to be larger than that on the side where the plate thickness of the joint portion 22c is increased.

[0023] In recent years, as part of efforts to improve development efficiency and reduce manufacturing costs, there has been a trend towards standardizing parts so that they can be used regardless of the type of automobile. In the case of the vehicle body frame part 10, when the first member 20 is manufactured by press molding, the main body 21 is manufactured by pressing the material between a pair of molds to cause plastic deformation, and a separate plate material (rib 22) is used to position the separate plate material and weld it to the main body 21.

[0024] In contrast, in this embodiment, since the first member 20 is manufactured by casting, the position of the ribs 22 relative to the main body 21 can be freely designed. Therefore, it is easier to accommodate design changes (for example, changes in model) related to changes in the arrangement of the ribs 22 relative to the main body 21. As a result, even if there is a design change, the process of positioning and joining (welding) another plate material (rib 22) to the main body 21 can be eliminated by appropriately changing the arrangement of the ribs 22 of the first member 20 relative to the main body 21 and the shape of the ribs 22.

[0025] The center line that bisects the thickness of the joint 22c is defined as the joint center line L1, which passes through the centroid of the joint 22c. However, the centroid of the joint 22c is defined as the centroid of the joint 22c ignoring the raised portion 22f of the joint 22c.

[0026] The second member 30 is a steel press-formed product and comprises a flat end portion 31 joined to each rib 22 (joint portion 22c) of a pair of left and right first members 20, and a plate-shaped base portion 32 connected between the end portions 31. The end portion 31 is bent upward relative to the base portion 32. The joining surface 22d of the joint portion 22c faces the joining surface 31b of the end portion 31, and the non-joint surface 22e of the joint portion 22c and the non-joint surface 31a of the end portion 31 face outward from each other. The recessed portion 31c is the part of the end portion 31 that protrudes downward from the joining surface 31b. The base portion 32 may be bent, curved, or have a corrugated surface. This can improve the strength of the base portion 32.

[0027] The plate thickness of the end portion 31 is constant, and the center line that bisects the plate thickness of the end portion 31 is the end portion center line L2, which passes through the centroid of the end portion 31. In this embodiment, in the joined state where the joint portion 22c and the end portion 31 are joined, the angle θ1 between the end portion center line L2 and the joint portion center line L1 is 1.5°. The vehicle body frame component 10 is joined by the end portion 31 of the second member 30 and the joint portion 22c of the first member 20 using a joining member 40. Because the plate thickness of the end portion 31 is constant and the angle θ1 is 1.5°, the plate thickness of the end portion 31 can be made thinner compared to the prior art. As a result, the vehicle body frame component 10 can be made lighter.

[0028] As described above, since the material used for the second member 30 has a higher specific gravity than the material used for the first member 20, if the plate thickness is reduced, the impact of the second member 30 on the overall weight of the vehicle body frame component 10 is greater than the impact of the first member 20 on the overall weight of the vehicle body frame component 10. Therefore, compared to the case where the material used for the first member 20 has a higher specific gravity than the material used for the second member 30, it is easier to further lighten the vehicle body frame component 10.

[0029] In this embodiment, the joining member 40 is a metal self-piercing rivet comprising a cylindrical shaft portion 41 extending from one end 41a to the other end 41b, and a substantially disc-shaped head portion 42 that forms the bottom of the shaft portion 41 on the one end 41a side. The shaft portion 41 is the part that penetrates the end portion 31 and is positioned in the joining portion 22c, and the head portion 42 is the part that is pressed by the punch 54, which will be described later. The shaft portion 41 has an R-chamfer on the inner edge of the other end 41b. In the joining process described later, the joining member 40 is driven into the joining portion 22c and the end portion 31 and plastically deformed.

[0030] The connecting member 40 has a shaft portion 41B on the tip 22b side of the inclination of the connecting portion 22c that extends outward more than the shaft portion 41A on the base 22a side of the inclination of the connecting portion 22c. Also, the shaft portion 41A on the base 22a side of the inclination of the connecting portion 22c has a longer vertical distance than the shaft portion 41B on the tip 22b side of the inclination of the connecting portion 22c. As a result, the vehicle body frame component 10 is shaped so that the shaft portion 41B, which is positioned in the thinner part of the connecting portion 22c, bites into the connecting portion 22c, thereby improving the joint strength between the connecting portion 22c and the end portion 31 in the direction from which the connecting member 40 can be pulled out (vertically above the non-jointed surface 31a of the end portion 31).

[0031] Referring to Figure 3, the method for joining the first member 20 and the second member 30 will be described. Figure 3(a) is a partial cross-sectional view of the vehicle body frame component 10 before it is joined by the joining member 40, and Figure 3(b) is a partial cross-sectional view of the vehicle body frame component 10 after it has been joined by the joining member 40.

[0032] As shown in Figures 3(a) and 3(b), the first member 20 and the second member 30 are joined together using a riveting machine 50. The riveting machine 50 is attached to the tip of a multi-joint robot (not shown) equipped with three or more rotary joints.

[0033] The riveting machine 50 comprises a main body (not shown) attached to the tip of an articulated robot, a C-shaped frame 51 connected to the main body, a cylindrical receiver 53 connected to one end 51a of the frame 51, and a cylindrical die 52 connected to the other end 51b of the frame 51. The tip surface 53a of the receiver 53 faces the upper surface 52a of the die 52.

[0034] The receiver 53 is driven by an electric servo motor and moves to and from the upper surface 52a of the die 52 in a vertical direction. This allows the tip surface 53a of the receiver 53 and the upper surface 52a of the die 52 to clamp the member to be joined (in this embodiment, the joint portion 22c and the end portion 31). The outer diameter of the receiver 53 is set to be approximately the same as the outer diameter of the die 52, or smaller than the outer diameter of the die 52.

[0035] A punch 54 that can move up and down along the inner circumferential surface is disposed inside the receiver 53, and a joining member 40 is positioned on the tip surface 54a side of the punch 54 with its head 42 facing the tip surface 54a of the punch 54. A magazine into which multiple joining members 40 are loaded is connected to the receiver 53. The joining members 40 are transported one by one into the inside of the receiver 53 by the magazine, and the transported joining members 40 are pressed toward the die 52 side by the downward movement of the punch 54, thereby driving the joining members 40 into the members to be joined.

[0036] The die 52 is a cylindrical member, and a groove 52b is formed in the center of its upper surface 52a. In this embodiment, the bottom of the groove 52b is flat, and the inner diameter of the groove 52b is set to be larger than the outer diameter of the shaft portion 41 of the joining member 40. The frame 51 is made of a material that has sufficient rigidity to withstand the clamping action between the receiver 53 and the die 52 and the punch load of the punch 54.

[0037] A joining method for mechanically joining a first member 20 and a second member 30 comprises a fixing step of fixing the joint portion 22c and the end portion 31 in a state where they are overlapped with the joining surface 31b facing the joining surface 22d of the joint portion 22c, and a joining step of joining the joint portion 22c and the end portion 31 fixed in the fixing step by bringing the upper surface 52a of the die 52 into contact with the non-joining surface 22e of the joint portion 22c and pressing the joining member 40 with the punch 54 toward the non-joining surface 31a of the end portion 31.

[0038] In the joining process, the receiver 53 is brought close to the die 52 with the upper surface 52a of the die 52 in contact with the non-joining surface 22e, and the joining portion 22c and end portion 31 are sandwiched between the die 52 and the receiver 53. This causes at least a portion of the joining portion 22c and end portion 31 to elastically deform so that the joining surface 22d of the joining portion 22c and the non-joining surface 31a of the end portion 31 are aligned with the tip surface 53a of the receiver 53. The following describes in detail each step (fixing step, joining step) in the joining method.

[0039] As shown in Figure 3(a), in the fixing process, the joint portion 22c of the first member 20 and the end portion 31 of the second member 30 are overlapped, and the main body 21 of the first member 20 and the base portion 32 of the second member 30 are fixed together using a fixing jig or the like (not shown).

[0040] Subsequently, as shown in Figure 3(b), in the joining process, with the main body 21 and the base 32 fixed in place by the fixing process, the riveting machine 50 is moved by an articulated robot so that the receiver 53 and the die 52 are positioned to clamp the overlapping portion of the joint 22c and the end portion 31. From that position, the receiver 53 of the riveting machine 50 moves toward the upper surface 52a of the die 52. As a result, the joint 22c and the end portion 31 are clamped between the tip surface 53a of the receiver 53 and the upper surface 52a of the die 52.

[0041] Next, with the joint portion 22c and end portion 31 sandwiched between the tip surface 53a of the receiver 53 and the upper surface 52a of the die 52, the punch 54 descends toward the die 52. The tip surface 54a of the punch 54 descends to a position where it is flush with the tip surface 53a of the receiver 53. As a result, the joint member 40, which was positioned closer to the die 52 than the punch 54, is pressed by the punch 54 and driven toward the die 52 toward the end portion 31 and joint portion 22c.

[0042] When the joint member 40 is driven in, the shaft portion 41 penetrates the end portion 31, and the other end portion 41b of the shaft portion 41 is inserted into the joint portion 22c. As a result, the portion of the end portion 31 in which the joint member 40 is driven in (particularly the portion inside the inner surface 41d of the shaft portion 41) is plastically deformed toward the joint portion 22c, forming a recessed portion 31c.

[0043] The other end 41b of the shaft portion 41 of the driven-in joining member 40 causes the joining portion 22c to plastically deform downward. The plastically deformed joining portion 22c enters the groove 52b of the die 52, forming a raised portion 22f. The other end 41b of the shaft portion 41 is restricted from plastically deforming downward by the groove bottom of the groove 52b, causing it to plastically deform to spread horizontally. As a result, the shaft portion 41 of the joining member 40 penetrates the end portion 31 and bites into the joining portion 22c horizontally, thus joining the end portion 31 and the joining portion 22c by the joining member 40.

[0044] In the joining process, with the main body 21 and the base 32 fixed in place by the fixing process, the joint portion 22c, which is separated from the main body 21, and the end portion 31, which is separated from the base 32, are sandwiched together. At that moment, the sandwiched joint portion 22c and end portion 31 elastically deform so as to bend along the tip surface 53a of the receiver 53. In this state, the joining member 40 is driven into the end portion 31 and the joint portion 22c.

[0045] According to the joining method and the vehicle body frame component 10 of this embodiment, the joining member 40 is positioned on the end 31 and the joint 22c in a state in which the shaft portion 41 of the joining member 40 penetrates the end 31, and the other end 41b of the shaft portion 41 is plastically deformed to bite into the joint 22c in a horizontal direction (parallel to the direction in which the end 31 extends). This improves the joining strength between the end 31 and the joint 22c in the direction in which the joining member 40 can be pulled out (perpendicular to the direction in which the end 31 extends).

[0046] Since the joining surface 22d of the joint portion 22c and the non-joint surface 31a of the end portion 31 are elastically deformed so that they align with the front end surface 53a of the receiver 53, at least a portion of the rib 22 (joint portion 22c) and the end portion 31 is elastically deformed, even if the non-joint surface 22e of the joint portion 22c that abuts the die 52 and the non-joint surface 31a that abuts the receiver 53 are inclined, the joining member 40 can be driven into the end portion 31 and the joint portion 22c with the head 42 and the non-joint surface 31a of the end portion 31 being substantially parallel. As a result, the end portion 31 and the joint portion 22c can be joined with a small gap between the head 42 and the non-joint surface 31a of the end portion 31. Therefore, compared to the case where the rib 22 and the end portion 31 do not elastically deform, a larger area can be secured for the joining member 40 to be driven into the end portion 31. Thus, the joining strength of the joint between the end portion 31 and the joint portion 22c can be improved.

[0047] According to the joining method and the vehicle body frame component 10 of this embodiment, the non-joining surface 22e of the joining portion 22c and the non-joining surface 31a of the end portion 31 are joined while they are inclined. Therefore, it is not necessary to process the cast surface of the joining portion 22c (the upper or lower surface of the draft rib 22) so that the joining surface 22d of the joining portion 22c and the joining surface 31b of the end portion 31 are parallel. Thus, the joining portion 22c can be joined to the end portion 31 using its cast surface as is. As a result, corrosion resistance can be improved compared to the case where the cast surface is processed after casting the first member 20. [Examples]

[0048] The present invention will be described in more detail with reference to Figure 4, but the present invention is not limited to this embodiment. Figure 4 is a longitudinal cross-sectional view of the test piece 60 in the embodiment. Figure 4 shows a cross-section cut by a plane that includes the center line of the joining member 40 and is aligned with the inclination direction of the joining portion 61b (left-right direction in the plane of Figure 4). In Figure 4, the directions of arrows U and D are described as the upward and downward directions of the test piece 60, respectively.

[0049] (Preparation of test specimen 60) As shown in Figure 4, a plate-shaped first test piece 61 with a width of 50 mm, a length of 150 mm, and a thickness of 1.0 or 1.2 mm was placed on a plate-shaped second test piece 62 with a width of 50 mm, a length of 150 mm, and a thickness of 3.5 mm or 5.0 mm. The first test piece 61 and the second test piece 62 were intersected at a 90° angle, with their central portions overlapping (so that the joining surface 61c of the first test piece 61 and the joining surface 62b of the second test piece 62 face each other), and then joined using the joining method described above to obtain six test pieces 60 each for Examples 1, 2, and the Comparative Example. Note that the test pieces 60 for Examples 1, 2, and the Comparative Example were prepared under the same conditions as the first test piece 61 and the second test piece 62, except for the material and thickness.

[0050] In Example 1, the following first and second test specimens 61 and 62 were used. The first test specimen 61 was made of an A365 series alloy, which is an aluminum alloy die-cast material specified by the AA (Aluminium Association), with a thickness of 5.0 mm for its flat portion 61a and a thickness of 4.5 mm for the central portion (hereinafter referred to as the joint portion) into which the joining member 40 is driven. The second test specimen 62 was made of JSC780Y, a high-tensile steel material specified in the JFS standard (Japan Iron and Steel Federation standard) A2001, with a thickness of 1.2 mm.

[0051] In Example 2, the following first and second test specimens 61 and 62 were used. The first test specimen 61 was the same as the first test specimen 61 used in Example 1. The second test specimen 62 was JAC590R-45 / 45, a high-tensile steel material specified in JFS standard (Japan Iron and Steel Federation standard) A2001, with a thickness of 1.0 mm. Note that 45 / 45 is a symbol indicating the amount of zinc plating on both sides, and the minimum amount of plating on both sides measured by the three-point method in accordance with the provisions of JIS (Japanese Industrial Standard) H0401:2021 was 60 g / m². 2 This indicates that...

[0052] In the comparative example, the following first test specimen 61 and second test specimen 62 were used. The first test specimen 61 was an A365 series alloy (the same alloy as used in Examples 1 and 2), which is an aluminum alloy die-cast material specified by the AA (Aluminium Association), and its thickness was a constant 3.5 mm. The second test specimen 62 was the same as the second test specimen 62 used in Example 1.

[0053] In Examples 1 and 2, the first test piece 61 before joining had a non-joined surface 61d processed in the 50 mm central part of the longitudinal direction so that the plate thickness decreased from one end (left side of Figure 4) to the other end (right side of Figure 4) in the longitudinal direction, thereby forming a joint 61b. Both ends of the joint 61b in the longitudinal direction were flat plate sections 61a. In Examples 1 and 2, the test piece 60 was set such that the center line (not shown) passing through the centroid of the joint 61b of the first test piece 61 intersects with the center line (not shown) passing through the centroid of the second test piece 62, and the angle at which these center lines intersect is 1.5°.

[0054] In Examples 1 and 2 and the Comparative Example, the first test piece 61 and the second test piece 62 underwent partial heat treatment by irradiating the bonded surface 61c and the non-bonded surface 62a with laser light using the same laser device and under the same conditions before joining.

[0055] After the partial heat treatment described above, the first test piece 61 and the second test piece 62 were joined by driving in the joining member 40 (self-piercing rivet) using the rivet driving machine 50. The joining member 40 was made of steel and cylindrical in shape, with a head 42 diameter of 7.75 mm, a head 42 thickness of 0.6 mm, an overall length (length in the driving direction) of 6 mm, a shaft portion 41 length of 4.5 mm, an outer diameter of the shaft portion 41 of 5.3 mm, and an inner diameter of the shaft portion 41 of 2.9 mm. The die 52 was made of steel and cylindrical in shape, with a groove 52b inner diameter of 12 mm, a groove 52b depth of 0.6 mm, and a flat bottom shape for the groove 52b.

[0056] In Examples 1 and 2 and the Comparative Example, the test specimen 60 had a raised portion 61e formed on the non-jointed surface 61d as the joint portion 61b was deformed by the jointing member 40.

[0057] (Cross-sectional measurements and results) Three of the six test pieces 60 in each of Examples 1 and 2 and the Comparative Example were cut along a plane that includes the center line of the joining member 40 and is aligned with the direction in which the joint portion 61b is inclined (left-right direction on the page of Figure 4). The distances D1 to D4 at the cut surface were measured, and the results are shown in Table 1.

[0058] Distance D1 is the distance between the outer surface 41c of the base (one end 41a) of the shaft portion 41 and the tip (other end 41b) of the shaft portion 41, and is a distance that extends parallel to the width direction (left-right direction on the paper in Figure 4) of the second test piece 62. Distance D2 is the distance between the base (one end 41a) of the shaft portion 41 and the tip (other end 41b) of the shaft portion 41, and is a distance that extends perpendicularly to the second test piece 62. Distance D3 is the distance at which the head portion 42 rises perpendicularly from the non-jointed surface 62a of the second test piece 62. Distance D4 is the distance from the tip (other end 41b) of the shaft portion 41 to the lower end of the raised portion 61e, where a perpendicular line drawn perpendicularly to the second test piece 62 extends. This distance is measured over the shorter of the two shaft portions 41: the shaft portion 41A on the thicker side of the joint portion 61b and the shaft portion 41B on the thinner side of the joint portion 61b.

[0059] For distances D3 and D4, the average of the three measured values ​​is shown in Table 1. For distances D1 and D2, the shaft portion 41A and shaft portion 41B at the cross-section were compared, and the measurement where the shaft portion 41A was more often larger was marked A, and the measurement where the shaft portion 41B was more often larger was marked B. If the quantities were approximately the same, or if all three were approximately the same size, it was marked as the same.

[0060] (Cross tensile strength test and results) The remaining three test specimens from Examples 1 and 2 and the Comparative Example (60 specimens) were tested in accordance with the specimen dimensions and test method for cruciate tensile testing of resistance spot and projection welded joints as specified in JIS (Japanese Industrial Standard) Z3137:1999. The average values ​​of the three cruciate tensile strength measurements obtained are shown in Table 1.

[0061] [Table 1]

[0062] As shown in Table 1, in Examples 1 and 2, the distance D1 was greater on the shaft portion 41A side than on the shaft portion 41B side, and the distance D2 was greater on the shaft portion 41B side than on the shaft portion 41A side.

[0063] In Examples 1 and 2, the test specimen 60 showed a cross-tensile strength approximately 20% higher than that of the test specimen 60 in the comparative example. In particular, comparing Example 1 with the comparative example, the material of the first test specimen 61 and the second test specimen 62 was the same, and furthermore, the plate thickness of the joint portion (joint portion 61b) of the first test specimen 61, which is a factor that reduces joint strength, was thicker in the test specimen 60 of Example 1 than in the test specimen 60 of the comparative example, yet the cross-tensile strength was higher in Example 1. It is presumed that the increased distance D1 on the shaft portion 41B side and the increased distance D2 on the shaft portion 41A side contributed to the improvement in cross-tensile strength (i.e., the joint strength of the first test specimen 61 and the second test specimen 62 in the direction in which the joint member 40 comes loose).

[0064] In Examples 1 and 2 and the Comparative Example, the test specimen 60 had a distance D3 of 0.33 to 0.36 mm. The distance D3 of the test specimen 60 in Examples 1 and 2 was equivalent to that of the test specimen 60 in the Comparative Example, and the distance D3 did not increase even with the test specimen 60 in Examples 1 and 2, which was good.

[0065] Furthermore, in Examples 1 and 2, the test specimen 60 had a distance D4 of 1.92 to 2.03 mm, while the test specimen 60 in the comparative example had a distance D4 of 1.28 mm. In Examples 1 and 2 and the comparative example, the distance D4 of the test specimen 60 was 10% or more of the plate thickness of the first test specimen 61, so in all cases there was little risk of the shaft portion 41 penetrating the first test specimen 61, and the bonding state was good.

[0066] According to this embodiment, in the test piece 60 in Embodiments 1 and 2, where the center line (not shown) passing through the centroid of the joint 61b of the first test piece 61 intersects with the center line (not shown) passing through the centroid of the second test piece 62, and the angle at which these center lines intersect is set to 1.5°, it was revealed that the distance D1 of the shaft portion 41B on the side of the joint 61b with a thicker plate thickness (the base side of the inclination of the joint 61b) is greater than the distance D1 of the shaft portion 41A on the side of the joint 61b with a thinner plate thickness (the tip side of the inclination of the joint 61b), and the distance D2 of the shaft portion 41A is greater than the distance D2 of the shaft portion 41B.

[0067] Furthermore, due to the relationship between the shaft portions 41A and 41B and the distances D1 and D2, it became clear that the test piece 60 in Example 1 could achieve a higher cross-tensile strength than the test piece 60 in the comparative example.

[0068] Although the present invention has been described above based on embodiments and examples, it can be easily inferred that the present invention is not limited in any way to the above embodiments and examples, and that various improvements and modifications are possible without departing from the spirit of the present invention.

[0069] In the embodiment described, the case in which the first member 20 is a rear frame and the second member 30 is a floor member was explained, but it is not limited to this as long as the first member 20 has a plate-shaped joint portion 22c and the second member 30 has a plate-shaped end portion 31. For example, the first member 20 may have a block-shaped main body 21, and the second member 30 may have a block-shaped base portion 32.

[0070] In this embodiment, the first member 20 is described as a die-cast product, but it may also be a cast product, an extruded product, or a press-formed product. Also, although the first member 20 is described as being made of an aluminum alloy, it may also be made of steel.

[0071] In the embodiment, the second member 30 was described as a pressed member, but it may also be a die-cast product, other castings, or an extruded product. In this case, the second member 30 is preferably made of an aluminum alloy.

[0072] In the embodiment, the case in which the vehicle body frame component 10 is joined by joining two plate-shaped portions (joint portion 22c and end portion 31) of the first member 20 and the second member 30, is described, but in addition to the joint portion 22c and end portion 31, it is also possible to join them with one or more plate-shaped members sandwiched between the joint portion 22c and the end portion 31.

[0073] In the embodiment, the case where the joining member 40 is an SPR (self-piercing rivet) was described, but the joining member may also be other rivets such as rivets for full-piercing rivet joining or blind rivets, or other mechanical joining methods such as FDS (registered trademark).

[0074] In the embodiment described, the die 52 is positioned on the joint portion 22c side and the receiver 53 is positioned on the end portion 31 side, and the joint portion 22c and the end portion 31 are sandwiched together. However, the die 52 and the receiver 53 may be positioned in the opposite direction when sandwiching each other.

[0075] In the embodiment, a case was described in which the joint portion 22c and the end portion 31 are joined by elastically deforming them so that they flex along the tip surface 53a of the receiver 53. However, the joint portion 22c and the end portion 31 may also be joined without elastically deforming them so that they flex along the tip surface 53a of the receiver 53. In this case, with the tip surface 53a of the receiver 53 parallel to the non-jointed surface 31a of the end portion 31 and the upper surface 52a of the die 52 inclined with respect to the non-jointed surface 22e of the joint portion 22c, the receiver 53 moves toward the upper surface 52a of the die 52 to clamp the joint portion 22c and the end portion 31. [Explanation of Symbols]

[0076] 10. Body frame components 20 First Member 21 Main unit 22 Ribs 22a Base 22c joint 30 Second Member 31 End 40 Joining members 41 Shaft 41a One end (root) 41b Other end (tip) 42 Head 61 First test specimen (first component) 61b Joint 62. Second test specimen (second member, end portion) D1 Distance D2 distance L1 Joint center line L2 End center line θ1 angle

Claims

1. A first metal member comprising a main body and plate-shaped ribs protruding from the main body, A second metal member including a plate-shaped end, The system includes a joining member that mechanically joins the rib and the end when the rib and the end are overlapped, The rib comprises a base connected to the main body, and a joint portion where the thickness of the plate decreases from the base side toward the opposite tip side, and where the joining member is positioned. A vehicle body frame component whose joint centerline, passing through the centroid of the joint, intersects with the end centerline, which passes through the centroid of the end.

2. The connecting member comprises a shaft portion and a head portion to which the base of the shaft portion is connected. The shaft portion penetrates at least the end, The tip of the shaft portion is located within the joint portion in a state that is spread out relative to the base of the shaft portion. The vehicle body frame component according to claim 1, wherein the angle between the center line of the joint and the center line of the end is 1.5° or less.

3. In a cross-section obtained by cutting along a plane that includes the center line of the joining member and is aligned with the direction in which the plate thickness of the joining portion decreases, The distance between the outer surface of the root of the shaft portion and the tip of the shaft portion in the direction in which the end centerline extends is such that the tip side of the rib is longer than the root side of the rib. The vehicle body frame component according to claim 2, wherein the distance between the root of the shaft portion and the tip of the shaft portion in the direction perpendicular to the end center line is such that the root side of the rib is longer than the tip side of the rib.

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