seat frame

Abstract

To provide a seat frame which can achieve both of strength against shear load and strength against peeling load.SOLUTION: In a seat frame, a plate-like member and a rod-like member, which has a plane part on at least a partial side face, are joined. Such joining is performed by a welding part having a base part which extends in a longer direction of the rod-like member, and of which a center line is positioned on a side where a load from a user is added during use of the seat frame with respect to a midship part in a direction orthogonal to the longer direction of the rod-like member, in a contact face of the plate-like member and the plane part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a seat frame.

Background Art

[0002] Conventionally, a seat frame for an automobile has ensured the strength of the seat frame by welding a pipe to a plate material (for example, see Patent Document 1). In Patent Document 1, a seat frame is manufactured by joining a square pipe having a square cross section with a cutting plane perpendicular to the longitudinal direction of the pipe and a round pipe having a circular cross section to a plate material. Generally, the pipe and the plate material are joined at the central portion of the pipe, for example, at the central portion in the radial direction in the cross section in the case of a circular pipe.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the above-described seat frame, a shear load and a peeling load are applied to the plate material and the pipe during use. In a seat frame, it is required to achieve both strength against shear and strength against peeling.

[0005] The present invention has been made in view of the above, and an object thereof is to provide a seat frame capable of achieving both strength against a shear load and strength against a peeling load.

Means for Solving the Problems

[0006] To solve the above-mentioned problems and achieve the objective, the present invention provides a sheet frame comprising a plate-shaped member and a rod-shaped member having a flat surface on at least a portion of its side surface, characterized in that the base portion extending in the longitudinal direction of the rod-shaped member is joined by a welded portion having a center line located on the side where the load from the user is applied when the sheet frame is in use, rather than the center of the contact surface between the plate-shaped member and the flat surface in a direction perpendicular to the longitudinal direction of the rod-shaped member.

[0007] Furthermore, the sheet frame according to the present invention is characterized in that, in the above invention, the welded portion is provided on the side opposite to the outer edge of the plate-shaped member, rather than on the central portion in a direction perpendicular to the longitudinal direction of the rod-shaped member.

[0008] Furthermore, the sheet frame according to the present invention is characterized in that the welded portion has a first extension portion extending from one end of the base portion in a direction intersecting the longitudinal direction of the rod-shaped member, and a second extension portion extending from the other end of the base portion in a direction intersecting the longitudinal direction of the rod-shaped member.

[0009] Furthermore, the sheet frame according to the present invention is characterized in that, in the above invention, the welded portion further comprises a third extending portion extending in the longitudinal direction of the rod-shaped member from the end of the first extending portion opposite to the side connected to the base portion, and a fourth extending portion extending in the longitudinal direction of the rod-shaped member from the end of the second extending portion opposite to the side connected to the base portion.

[0010] Furthermore, the sheet frame according to the present invention is characterized in that the first and second extending portions extend in a straight line.

[0011] Furthermore, the sheet frame according to the present invention is characterized in that the first and second extending portions extend in an arc shape.

[0012] Furthermore, the sheet frame according to the present invention is characterized in that, in the above invention, the welded portion further has a connecting portion that connects the end of the first extension portion opposite to the side connected to the base portion and the end of the second extension portion opposite to the side connected to the base portion.

[0013] Furthermore, the sheet frame according to the present invention is characterized in that, in the above invention, the rod-shaped member has a rectangular cross-section with a plane perpendicular to the longitudinal direction as the cutting surface.

[0014] Furthermore, the sheet frame according to the present invention is characterized in that, in the above invention, the rod-shaped member is cylindrical.

[0015] Furthermore, the sheet frame according to the present invention is characterized in that, in the above invention, the plate-shaped member and the rod-shaped member are each made of aluminum or an aluminum alloy. [Effects of the Invention]

[0016] According to the present invention, it is possible to achieve both strength against shear load and strength against peeling load. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a front view of an automobile seat frame according to one embodiment of the present invention. [Figure 2] Figure 2 is a view of the underside of the automotive seat frame shown in Figure 1. [Figure 3] Figure 3 is an enlarged view of region R shown in Figure 2. [Figure 4] Figure 4 is a partially enlarged cross-sectional view of line AA in Figure 3. [Figure 5] Figure 5 is a diagram illustrating the joining method of an automobile seat frame according to Modification 1. [Figure 6] Figure 6 is a diagram illustrating the joining method of an automobile seat frame according to Modification 2. [Figure 7]FIG. 7 is a diagram for explaining the joining mode of the seat frame for an automobile according to Modification Example 3. [Figure 8] FIG. 8 is a diagram for explaining the joining mode of the seat frame for an automobile according to Modification Example 4. [Figure 9] FIG. 9 is a diagram for explaining the joining mode of the seat frame for an automobile according to Modification Example 5. [Figure 10] FIG. 10 is a diagram for explaining the joining mode of the seat frame for an automobile according to Modification Example 6. [Figure 11] FIG. 11 is a diagram for explaining the joining mode of the seat frame for an automobile according to Modification Example 7. [Figure 12] FIG. 12 is a diagram for explaining the welding position according to the embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing the change ratio of the shear strength and the peel strength in Embodiments 2 and 3 and Comparative Examples 1 and 2 with respect to Embodiment 1.

MODE FOR CARRYING OUT THE INVENTION

[0018] Hereinafter, the mode for carrying out the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by the following embodiments. Also, each drawing referred to in the following description only schematically shows the shape, size, and positional relationship to the extent that the content of the present invention can be understood. That is, the present invention is not limited only to the shape, size, and positional relationship illustrated in each drawing.

[0019] (Embodiment) First, the seat frame for an automobile according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of the seat frame for an automobile according to an embodiment of the present invention. FIG. 2 is a rear view of the seat frame for an automobile in FIG. 1. FIG. 3 is an enlarged view of the region R shown in FIG. 2. FIG. 4 is a partially enlarged cross-sectional view taken along the line A-A in FIG. 3.

[0020] The seat frame 1 for automobiles (hereinafter simply referred to as seat frame 1) comprises a back panel 2 made of aluminum or an aluminum alloy and a frame tube 3 made of aluminum or an aluminum alloy. The seat frame 1 is fixed to the back panel 2 by joining the back panel 2 and the frame tube 3 together.

[0021] The back panel 2 is a thin sheet of aluminum or aluminum alloy, formed by press working or the like. While high-strength aluminum alloys are preferred for the back panel 2, from the viewpoint of ease of molding, for example, the 5000 series (Al-Mg series) and 6000 series (Al-Mg-Si series) are suitable.

[0022] The frame tube 3 is a pipe made of aluminum or an aluminum alloy with a rectangular cross-section (see Figure 4). Because the frame tube 3 has a rectangular cross-section, it has flat surfaces on part of its surface. Specifically, the outer edge of the frame tube 3 in cross-section has four flat surfaces and four corners arranged alternately. The corners are chamfered to form an arc shape. The frame tube 3 is joined to the back panel 2 with its flat surfaces in contact. Furthermore, a high-strength aluminum alloy is preferred for the frame tube 3, such as the 2000 series (Al-Cu-Mg series), 5000 series, 6000 series, and 7000 series (Al-Zn-Mg series). The frame tube 3 may have a polygonal cross-section other than a rectangle. In addition to being a cylindrical member, the frame tube 3 may also be a solid member. The back panel 2 and frame tube 3 are not limited to aluminum or aluminum alloy; other metals such as iron or other alloys can be used.

[0023] The back panel 2 and the frame tube 3 are joined by a weld 4. The weld 4 is in a straight line extending in the longitudinal direction of the frame tube 3. The weld 4 is formed, for example, by laser welding. The back panel 2, the frame tube 3, and the weld 4 form a joint. The weld 4 may be formed as a single row of straight weld marks, or as multiple rows (for example, three rows) of weld marks arranged perpendicular to the longitudinal direction of the frame tube 3.

[0024] In this embodiment, the direction perpendicular to the longitudinal direction of the frame tube 3, extending along the surface of the frame tube 3 that contacts the back panel 2, is defined as the width direction of the frame tube 3. In contrast, the direction extending upward relative to the back panel 2 is defined as the thickness direction of the frame tube 3. The longitudinal direction corresponds to the direction perpendicular to the cross-section described above, and in the case of a pipe, it is the direction in which the hollow space extends.

[0025] Next, we will explain the method of joining the back panel 2 and the frame tube 3. The seat frame 1, which connects the back panel 2 and the frame tube 3, is subjected to loads during use. Specifically, loads are applied to the seat frame 1 when a passenger leans on the seat or when it receives an impact from the cargo area. When it receives an impact from the cargo area, a shear load F1 is applied between the back panel 2 and the frame tube 3. Also, when a passenger leans on the seat, a peeling load F2 is applied between the back panel 2 and the frame tube 3. The shear load F1 and the peeling load F2 act on the back panel 2 and the frame tube 3 in opposite directions. Specifically, the shear load F1 is a load applied in a direction that shifts the joint position between the back panel 2 and the frame tube 3. In contrast, the peeling load F2 is a load applied in a direction that separates the back panel 2 and the frame tube 3 from each other.

[0026] The joint position between the back panel 2 and the frame tube 3 in the seat frame 1 is determined according to the position of the frame tube 3 relative to the back panel 2. Specifically, the back panel 2 and the frame tube 3 are joined on the inside side of the back panel 2 relative to the central axis N in the width direction of the frame tube 3. Here, the inside side of the back panel 2 refers to the side toward the opposite outer edge of the connection surface of the frame tube 3 on the back panel 2, and is the side on which the load is applied. That is, the inside of the load is, for example, the side of the back panel 2 closer to the point of force application of the load when a load is applied to the back panel 2 from a passenger sitting on the seat, with the central axis N of the frame tube 3 as the boundary. Conversely, the side opposite the point of force application with respect to the central axis N of the frame tube 3 is the outside of the load. The welded joint 4 is formed in the portion where the flat surfaces of the back panel 2 and the frame tube 3 are in contact (for example, the area d shown in Figure 4). Furthermore, although Figure 3 illustrates a configuration in which the welded joint 4 is located inside the load from the central axis N of the frame pipe 3, it is sufficient that the center line L of the welded joint 4 is located inside the load from the central axis N of the frame pipe 3, and a portion of the welded joint may overlap with the central axis N.

[0027] In the embodiment described above, the sheet frame 1 is manufactured by joining a back panel 2 and a frame tube 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame tube 3. According to this embodiment, by forming a welded joint 4 at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined. Furthermore, by making the back panel 2 and the frame tube 3 from aluminum or an aluminum alloy, the weight can be reduced compared to using iron.

[0028] In Figure 2, the welded joint 4 was described as an example of a weld formed by performing laser welding at multiple points in a straight line, but it is not limited to this, and for example, it may be a configuration of welding at only one point. Also, the joint between the back panel 2 and the frame pipe 3 is not limited to a straight line, as long as the joint is on the inside of the load. Other forms of welded joints will be described below.

[0029] (Variation 1) Figure 5 is a diagram illustrating the joining method of an automobile seat frame according to Modification 1. In this Modification 1, the seat frame is provided with a welded joint 4A instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0030] The welded section 4A is located on the interior side of the back panel 2 relative to the central axis N of the frame tube 3 and has a linear base section 41 extending in the longitudinal direction of the frame tube 3, a first extension section 42 extending linearly from one end of the base section 41 toward the exterior side of the back panel 2, and a second extension section 43 extending linearly from the other end of the base section 41 toward the exterior side of the back panel 2. Both the first extension section 42 and the second extension section 43 extend to the exterior side of the central axis N of the frame tube 3.

[0031] In the modified example 1 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4A. In the welded joint 4A, the base portion 41, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 1, by forming the welded joint 4A at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined.

[0032] Furthermore, in the modified example 1, the strength against shear can be further increased by providing a first extended portion 42 and a second extended portion 43 that extend in the direction in which the shear load is applied.

[0033] (Modification 2) Figure 6 is a diagram illustrating the joining method of an automobile seat frame according to Modification 2. In this Modification 2, the seat frame is provided with a welded joint 4B instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0034] The welded portion 4B, like the welded portion 4A, has a base portion 41, a first extension portion 42, and a second extension portion 43, and also has a third extension portion 44 extending in the longitudinal direction of the frame pipe 3 from the end of the first extension portion 42 opposite to the side connected to the base portion 41, and a fourth extension portion 45 extending in the longitudinal direction of the frame pipe 3 from the end of the second extension portion 43 opposite to the side connected to the base portion 41.

[0035] In the modified example 2 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4B. In the welded joint 4B, the base portion 41, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 2, by forming the welded joint 4B at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined.

[0036] Furthermore, in the modified example 2, the strength against shear can be further increased by providing a first extended portion 42 and a second extended portion 43 that extend in the direction in which the shear load is applied, and the strength against peeling can be further increased by providing a third extended portion 44 and a fourth extended portion 45 that extend in the direction in which the peeling load is applied.

[0037] In the modified example 2, a configuration was described in which the third extending portion 44 and the fourth extending portion 45 extend in a direction toward each other. However, a configuration in which the third extending portion 44 and the fourth extending portion 45 extend in a direction toward each other is also possible.

[0038] (Variation 3) Figure 7 is a diagram illustrating the joining method of an automobile seat frame according to Modification 3. In this Modification 3, the seat frame is provided with a welded joint 4C instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0039] The welded section 4C, like the welded section 4A, has a base section 41, a first extension section 42, and a second extension section 43, and also has a connecting section 46 that connects the end of the first extension section 42 opposite to the side connected to the base section 41, and the end of the second extension section 43 opposite to the side connected to the base section 41. The welded section 4C forms a rectangle and joins the back panel 2 and the frame pipe 3.

[0040] In the modified example 3 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4C. In the welded joint 4C, the base portion 41, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 3, by forming the welded joint 4C at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined.

[0041] Furthermore, in the modified example 3, the strength against shear can be further increased by providing a first extended portion 42 and a second extended portion 43 that extend in the direction in which the shear load is applied, and the strength against peeling can be further increased by providing a connecting portion 46 that extends in the direction in which the peeling load is applied.

[0042] (Modification 4) Figure 8 is a diagram illustrating the joining method of an automobile seat frame according to Modification 4. In this Modification 4, the seat frame is provided with a welded joint 4D instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0043] The welded section 4D has a base section 41 similar to that of the welded section 4A, a first extension section 47 extending in an arc shape from one end of the base section 41 to the outside of the back panel 2, and a second extension section 48 extending in an arc shape from the other end of the base section 41 to the outside of the back panel 2. Both the first extension section 47 and the second extension section 48 extend beyond the central axis N of the frame tube 3.

[0044] In the modified example 4 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4D. In the welded joint 4D, the base portion 41, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 4, by forming the welded joint 4D at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined while also being lightweight.

[0045] Furthermore, in the modified example 4, the strength against shear and peeling can be further increased by providing the first extended portion 47 and the second extended portion 48 which extend in an arc shape.

[0046] (Variation 5) Figure 9 is a diagram illustrating the joining method of an automobile seat frame according to Modification 5. In this Modification 5, the seat frame is provided with a welded joint 4E instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0047] The welded portion 4E, like the welded portion 4D, has a base portion 41, a first extension portion 47, and a second extension portion 48, as well as a connecting portion 49 that connects the end of the first extension portion 47 opposite to the side connected to the base portion 41, and the end of the second extension portion 48 opposite to the side connected to the base portion 41. The welded portion 4E is approximately elliptical in shape and joins the back panel 2 and the frame pipe 3.

[0048] In the modified example 5 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4E. In the welded joint 4E, the base portion 41, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 5, by forming the welded joint 4E at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined.

[0049] Furthermore, in modified example 5, the strength against shear and peeling can be further increased by providing the first extended portion 47, the second extended portion 48, and the connecting portion 49.

[0050] (Experimental variation 6) Figure 10 is a diagram illustrating the joining method of an automobile seat frame according to Modification 6. In this Modification 6, the seat frame is provided with a welded joint 4F instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0051] The welded section 4F has the base section 41 described above and an extended section 50 that extends from the longitudinal center of the base section 41. The welded section 4F is T-shaped and joins the back panel 2 and the frame pipe 3.

[0052] In the modified example 6 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4F. At the welded joint 4F, the base portion 41, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 6, by forming the welded joint 4F at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined.

[0053] Furthermore, in the modified example 6, the strength against shear can be further increased by providing an extended portion 50 that extends in the direction in which the shear load is applied.

[0054] (Example 7) Figure 11 is a diagram illustrating the joining method of an automobile seat frame according to Modification 7. In this Modification 7, the seat frame is provided with a welded joint 4G instead of the welded joint 4 described above. The following description of the same configuration as in the above embodiment (back panel 2 and frame tube 3) will be omitted.

[0055] The welded joint 4G has a base portion 51 that extends in the longitudinal direction of the frame pipe 3 and an extended portion 52 that extends through the longitudinal center of the base portion 51. The welded joint 4G joins the back panel 2 and the frame pipe 3 in a plus (+) shape.

[0056] In the modified example 7 described above, the back panel 2 and the frame pipe 3 are joined by a welded joint 4G. In the welded joint 4G, the base portion 51, similar to the embodiment, joins the back panel 2 and the frame pipe 3, each made of aluminum or an aluminum alloy, on the interior side of the back panel 2 relative to the central axis N of the frame pipe 3, thereby creating a sheet frame. According to this modified example 7, by forming the welded joint 4G at a position that satisfies the above-mentioned relationship, the strength against shear and peeling can be increased, and as a result, the plate-shaped member and the pipe-shaped member can be firmly joined.

[0057] Furthermore, in the modified example 7, the strength against shear can be further increased by providing an extended portion 52 that extends in the direction in which the shear load is applied.

[0058] Furthermore, the welded joint is not limited to the T-shape and +-shape described above; H-shape and other shapes can also be applied.

[0059] Thus, the present invention may include various embodiments not described herein, and various design modifications can be made without departing from the technical idea specified by the claims. [Examples]

[0060] The following describes embodiments of the automobile seat frame according to the present invention. However, the present invention is not limited to these embodiments.

[0061] In the examples, joints consisting of an aluminum alloy back panel for strength measurement and a frame tube were fabricated with varying joint positions (weld formation positions) relative to the frame tube, and the shear strength and peel strength of each joint were measured. The materials, shapes, welding conditions (beam pattern, power, irradiation time, etc.), and weld shapes of the back panel and frame tube used in each example were the same. In these examples, joints for measurement were fabricated using a 5000 series aluminum alloy back panel and a 7000 series aluminum alloy frame tube.

[0062] Figure 12 is a diagram illustrating the welding position according to an embodiment of the present invention. In the width direction of the frame tube 300, the position through which the central axis N passes is defined as zero. Also, in the width direction, the inside of the load is defined as the positive direction, and the outside of the load is defined as the negative direction.

[0063] (Example 1) The weld was formed at the zero position (on the central axis N) in the width direction of the frame tube 300, when viewed from the thickness direction of the frame tube 300. In this embodiment 1, the shear strength and peel strength were measured.

[0064] (Example 2) The widthwise length of the frame tube 300 was denoted as W (see Figure 4), and the weld was formed at a position shifted by W / 8 in the positive widthwise direction from the zero position. In this Example 2, the shear strength and peel strength were measured, and the percentage change in strength compared to Example 1 was calculated. The calculation results are shown in Table 1. [Table 1]

[0065] (Example 3) The weld was formed at a position shifted by W / 4 in the positive width direction from the zero position. In this Example 2, the shear strength and peel strength were measured, and the percentage change in strength compared to Example 1 was calculated.

[0066] (Comparative Example 1) The weld was formed at a position shifted by W / 8 in the negative width direction from the zero position. In this Comparative Example 1, the shear strength and peel strength were measured, and the percentage change in strength compared to Example 1 was calculated.

[0067] (Comparative Example 2) The weld 4 was formed at a position shifted by W / 4 in the negative direction in the width direction from the zero position. In this Comparative Example 1, the shear strength and peel strength were measured, and the percentage change in strength compared to Example 1 was calculated.

[0068] Figure 13 shows the percentage change in shear strength and peel strength in Examples 2 and 3 and Comparative Examples 1 and 2 compared to Example 1. It can be seen that the joints in Examples 2 and 3 show increased shear and peel strengths compared to Example 1, in which the weld was formed on the central axis N. On the other hand, the joints in Comparative Examples 1 and 2 show decreased shear and peel strengths compared to Example 1. From these results, it can be said that by placing the weld 4 on the inside of the load, the strength against shear and peel can be increased compared to the case where the weld is formed on the central axis N.

[0069] As described above, the joint and the seat frame for automobiles according to the present invention are suitable for achieving both strength against shear load and strength against peel load. [Explanation of Symbols]

[0070] 1. Automotive seat frame 2 Back Panels 3 Frame tubes 4, 4A~4F Welded Sections 41 Base section 42, 47 1st extension part 43, 48 2nd extension part 44 Third extension part 45 4th extension part 46, 49 Connection part 50 Extension

Claims

1. A sheet frame formed by joining a plate-shaped member and a rod-shaped member having a flat portion on at least a part of its side surface, A base portion extending linearly in the longitudinal direction of the rod-shaped member, wherein the center line is located on the side where the load from the user is applied when the seat frame is in use, rather than the center portion in the direction perpendicular to the longitudinal direction of the rod-shaped member at the contact surface where the plate-shaped member and the flat portion overlap, and is joined by a welded joint having a base portion formed by solidifying a part of the plate-shaped member and the rod-shaped member. A seat frame characterized by the following features.

2. The welded portion is provided on the side opposite to the outer edge of the plate-shaped member, rather than on the central part in the direction perpendicular to the longitudinal direction of the rod-shaped member. The seat frame according to feature 1.

3. The aforementioned welded joint is A first extending portion extends from one end of the base portion in a direction intersecting the longitudinal direction of the rod-shaped member, A second extending portion extends from the other end of the base portion in a direction intersecting the longitudinal direction of the rod-shaped member, A seat frame according to claim 1 or 2, characterized by having the following features.

4. The aforementioned welded joint is A third extension extends from the end of the first extension opposite to the side connected to the base portion, in the longitudinal direction of the rod-shaped member, A fourth extension extends from the end of the second extension opposite to the side connected to the base, in the longitudinal direction of the rod-shaped member, The seat frame according to claim 3, further characterized by having the following:

5. The first and second extensions extend in a straight line, The seat frame according to feature 3.

6. The first and second extending portions extend in an arc shape, The seat frame according to feature 3.

7. The aforementioned welded joint is A connecting portion that connects the end of the first extension portion opposite to the side connected to the base portion and the end of the second extension portion opposite to the side connected to the base portion, The seat frame according to claim 3, further characterized by having the following:

8. The rod-shaped member has a rectangular cross-section, with the cutting plane being perpendicular to the longitudinal direction. A seat frame according to any one of features 1 to 7.

9. The aforementioned rod-shaped member is cylindrical, A seat frame according to any one of features 1 to 8.

10. The plate-shaped member and the rod-shaped member are each made of aluminum or an aluminum alloy. A seat frame according to any one of features 1 to 9.

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