JP7317553B2 - Seat frame and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a seat frame and a method of manufacturing the same, and more particularly to a seat frame and a seat frame that can ensure welding strength between a wire and a frame body while absorbing variations in the distance between a first frame and a second frame and the length of the wire. It relates to a manufacturing method.

2. Description of the Related Art A seat frame mounted on a vehicle such as an automobile has a plurality of wires stretched over a first frame and a second frame separated from each other in a frame-like frame body, and both ends of the wire are connected to the first frame and the second frame. Each welded to the frame. For example, in the technique disclosed in Patent Document 1, both ends of a wire are bent with a curvature smaller than the curvature of the outer peripheral surface of a cylindrical first frame or a second frame to form a curved portion, and the curved portion is They are welded to the first frame and the second frame, respectively. As a result, even if the gap between the first frame and the second frame and the length of the wire vary due to manufacturing errors, etc., by shifting the contact position with the bending portion in the circumferential direction of the first frame and the second frame, the The curved portion can be welded to the 1st frame or the 2nd frame.

JP 2013-35333 A

However, in the technique disclosed in Patent Document 1, the curvature of the outer peripheral surface of the first frame and the second frame and the curvature of the curved portion are positively different from each other. The length of the contact portion between the and the curved portion is shortened. Since the welded portion formed by welding the contact portion becomes short, there is a problem that sufficient welding strength cannot be secured between the wire and the frame body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and secures the welding strength between the wire and the frame main body while absorbing variations in the distance between the first frame and the second frame and the length of the wire. It is an object of the present invention to provide a seat frame and a method for manufacturing the same.

To achieve this object, the seat frame of the present invention comprises a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; a wire whose both ends are welded to the first frame and the second frame, respectively, wherein at least one of the first frame and the second frame includes an inclined surface inclined inwardly of each other; The wire includes a body portion extending in the first direction and a bent end portion bent in the second direction with respect to the body portion, and a first weld is provided between the inclined surface and the bent end portion. part is formed.

According to the seat frame of claim 1, one of the first frame and the second frame, which are separated from each other in the first direction and extend in the second direction, has an inclined surface inclined toward the other . A first welded portion is formed between this inclined surface and a bent end bent in the second direction with respect to the main body. As a result, even if the gap between the first frame and the second frame and the length between both ends of the wire vary, the variation can be absorbed by shifting the bent end in the first direction along the inclined surface. A first weld can be formed between the inclined surface and the bent end.

Furthermore, since the bent ends are provided so as to bend in the second direction in which the first frame and the second frame extend, the length of the contact portion between the bent ends and the inclined surface can be ensured during welding. Since the length of the first welded portion formed by welding the contact portion can be ensured, the welding strength of the first welded portion can be ensured. As a result, the welding strength between the wire and the frame main body can be ensured while absorbing variations in the distance between the first frame and the second frame and the length of the wire.
The other of the first frame and the second frame is provided with a cylindrical portion extending in the second direction. The wire is provided with a curved end curved along the outer peripheral surface of the cylindrical portion as viewed from the second direction and curved in an arc so as to be in line contact with a portion of the outer peripheral surface of the cylindrical portion. A third welded portion is formed between the outer peripheral surface of the cylindrical portion and the curved end portion. As a result, when the wire is welded to the frame body, a force perpendicular to the first direction and the second direction (e.g., gravity) is applied from the curved end to the cylindrical portion. The contact position can be kept substantially constant. As a result, variation in the position of the third weld formed between the cylindrical portion and the curved end portion can be suppressed, thereby facilitating welding of the cylindrical portion and the curved end portion.

According to the seat frame of claim 2, in addition to the effects of the seat frame of claim 1, the following effects are obtained. Since the slanted surface is a part of the cylindrical surface, when bending the end of the wire perpendicular to the slanted surface (cylindrical surface) along the slanted surface and welding the end to the slanted surface, If the wire is not bent precisely, the length of the contact portion between the end of the wire and the inclined surface tends to vary. On the other hand, since the first welded portion is formed by welding the bent end portion bent in the second direction with respect to the main body portion to the inclined surface, the bent end portion is bent along the inclined surface which is a part of the cylindrical surface. Even if it deviates in the first direction, variations in the length of the contact portion between the inclined surface and the bent end can be suppressed. As a result, variations in welding strength between the inclined surface and the wire can be suppressed.

According to the seat frame of claim 3, in addition to the effects of the seat frame of claim 1 or 2, the following effects are obtained. In the state where the third welded portion is formed, the outer peripheral surface of the cylindrical portion and the curved end portion move away from the portion where the curved end portion and part of the outer peripheral surface of the cylindrical portion are in line contact with each other in the circumferential direction of the cylindrical portion. The gap between is gradually increased. Thereby, when forming the third welded portion, it is possible to guide the cylindrical portion and the curved end portion to come into contact with each other at a substantially constant contact position.

A seat frame manufacturing method according to claim 4 includes a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; and a wire welded at each end to a second frame. Each of the first frame and the second frame includes inclined surfaces that are inclined inwardly of each other . The wire includes a main body portion extending in the first direction, and bent end portions provided at both ends of the wire and bent in the second direction with respect to the main body portion . In the first jig step, in a state in which the frame body is fixed to the jig body with the inclined surface oriented in the vertical direction, the body is positioned in the second direction while being movable in the first direction with respect to the frame body by the first jig. do. In a fourth jig step after the first jig step, a pair of fourth jigs that are formed symmetrically in the first direction and move vertically in conjunction with each other are used to bend each end of the wire in contact with the inclined surface. It restricts the downward movement of the edge. In the welding process after such a fourth jig process, the bent ends are welded to the inclined surfaces at both ends of the wire to form the first welded parts. Easy to do. Also, during welding, variations in the distance between the first frame and the second frame and the length of the wire can be dispersed and absorbed at both ends of the wire, and the gap between the first and second frames and both ends of the wire can be absorbed. The welding strength can be secured and the welding strength between the wire and the frame main body can be further improved.

A seat frame manufacturing method according to claim 5 includes a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; and a wire welded at each end to a second frame . One of the first frame and the second frame has an inclined surface that inclines toward the other. The other of the first frame and the second frame has a planar portion whose cross section perpendicular to the second direction is formed in a straight line extending in the first direction. The wire includes a body portion extending in a first direction, a bent end portion bent in a second direction with respect to the body portion, and a straight end portion extending in the first direction. In the first jig step, with the frame main body fixed to the jig main body, the main body portion is positioned in the second direction while being movable in the first direction with respect to the frame main body by the first jig. In the second jig step after the first jig step, the bent end is sandwiched in the first direction between the second jig and the inclined surface. In the welding step after the second jig step, the bent end is welded to the inclined surface to form the first welded portion. Facilitates welding work with surfaces. Furthermore, in the welding process, the straight end portion is welded to the flat portion at a preset position on the jig body to form the second weld portion, so that the straight end portion and the flat portion can be easily welded. As a result, welding of the wire to the frame body can be made easier.

A seat frame manufacturing method according to claim 6 includes a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; and a wire welded at each end to a second frame . One of the first frame and the second frame has an inclined surface that inclines toward the other. The other of the first frame and the second frame has a cylindrical portion extending in the second direction. The wire has a body portion extending in a first direction, a bent end portion bent in a second direction with respect to the body portion, and a curved end portion curved along the outer peripheral surface of the cylindrical portion when viewed from the second direction. Prepare. In the first jig step, with the frame body fixed to the jig body with the inclined surface facing upward, the curved end portion is placed on the cylindrical portion, and the body portion is moved in the first direction with respect to the frame body by the first jig. Positioning in the second direction while allowing movement to. In the third jig step after the first jig step, downward movement of the bent end in contact with the inclined surface is restricted by a vertically movable third jig. Accordingly, it is possible to prevent the wire from shifting in the first direction due to the bent end portion moving downward along the inclined surface, and the state in which the curved end portion is in contact with the uppermost portion of the cylindrical portion can be maintained. In the welding step, the bent end is welded to the inclined surface to form the first welded portion, and the curved end is welded to the cylindrical portion to form the third welded portion. In this manner, welding can be performed in a state in which the position of the wire with respect to the frame body is determined by the first jig and the third jig, so welding of the wire with respect to the frame body can be facilitated.

It is a front view of a seat frame in a 1st embodiment. (a) is a cross-sectional view of the back frame along line IIa-IIa in FIG. 1, and (b) is a cross-sectional view of the back frame along line IIb-IIb in FIG. FIG. 4 is a plan view of a frame body and wires set in a welding jig; FIG. 4 is a cross-sectional view of the frame body and wires taken along line IV-IV of FIG. 3; 4(a) is a schematic diagram illustrating a method of positioning a wire with respect to a frame body, and (b) is a schematic cross-sectional view of the frame body and the wire taken along line Vb-Vb of FIG. 3. FIG. (a) is a schematic diagram showing the shortest dimension of wire permissible with respect to the space between side frames, and (b) is a schematic diagram showing the longest dimension of wire permissible with respect to the space between side frames. It is a diagram. (a) is a cross-sectional view of the back frame in the second embodiment, (b) is a schematic diagram illustrating a method of positioning the wire with respect to the side frame, and (c) is a wire positioned with respect to the side frame. It is a schematic diagram explaining a state. (a) is a cross-sectional view of a welding jig and a side frame in a third embodiment; (b) is a schematic diagram illustrating a method of positioning a wire with respect to the side frame; is a schematic diagram for explaining a state in which the is positioned.

Preferred embodiments are described below with reference to the accompanying drawings. First, a seat frame 1 according to the first embodiment will be described with reference to FIG. As shown in FIG. 1, a seat frame 1 is a frame provided on a seat mounted in a vehicle such as an automobile. The seat frame 1 includes a cushion frame 2, a back frame 3 arranged at the rear end portion of the cushion frame 2, and a connecting device 4 connecting the rear end portion of the cushion frame 2 and the lower end portion of the back frame 3. Prepare. The connecting device 4 is a reclining device capable of changing the angle of the back frame 3 with respect to the cushion frame 2 .

The arrow UD direction, the arrow FB direction, and the arrow LR direction shown in each drawing are the up-down direction, the front-rear direction, and the left-right direction of the back frame 3, respectively. The vertical and longitudinal directions of the back frame 3 do not change even if the angle of the back frame 3 with respect to the cushion frame 2 changes. In the description of the back frame 3 with reference to FIGS. 1 and 2, the up-down direction, front-rear direction, and left-right direction of the back frame 3 are simply referred to as up-down direction, front-back direction, and left-right direction.

The cushion frame 2 is a steel frame of a seat cushion on which a seated person sits. The cushion frame 2 is formed in a substantially square frame shape and attached to a vehicle body (not shown). A cushion frame 2 supports a cushion pad (not shown) made of foamed synthetic resin such as elastic soft polyurethane foam, and a cover (not shown) made of fabric, synthetic leather, leather, or the like covers the cushion pad. A seat cushion is formed over it.

The back frame 3 is a steel frame of a seat back that serves as a backrest for a seated person. A back pad (not shown) made of foamed synthetic resin such as elastic soft polyurethane foam is supported by the back frame 3, and the back pad is covered with a cover (not shown) made of fabric, synthetic leather, leather, or the like. A seat back is formed over it.

The back frame 3 includes a substantially rectangular frame-shaped frame body 10 and a plurality of columnar wires 15 , 16 , 17 that span the frame body 10 . The frame main body 10 includes a pair of side frames 11 and 12 which are arranged apart from each other in the horizontal direction and extend in the vertical direction, and an upper frame 13 which connects the upper portions of the pair of left and right side frames 11 and 12 to each other and extends in the horizontal direction. and a lower frame 14 extending in the left-right direction connecting lower portions of the side frames 11 and 12 to each other.

The side frame 11 is arranged on the right side of the back frame 3 , and the side frame 12 is arranged on the left side of the back frame 3 . The side frames 11 and 12 respectively include cylindrical portions 11a and 12a whose upper portions are connected to the upper frame 13, and plate portions 11b and 12b which are welded to the lower portions of the cylindrical portions 11a and 12a. The axial direction of the cylindrical portions 11 a and 12 a is the vertical direction of the back frame 3 .

The plate portions 11b and 12b are members formed by bending a steel plate. The plate portions 11b and 12b have flanges projecting inward in the left-right direction of the pair of side frames 11 and 12 from the front and rear edges. The rigidity of the side frames 11 and 12 can be ensured by the flanges while reducing the weight of the lower portions of the side frames 11 and 12 by the plate portions 11b and 12b.

The upper frame 13 is a cylindrical portion, and the left end thereof is formed integrally with the cylindrical portion 12 a of the side frame 12 . A fixture 8 for fixing a headrest (not shown) is attached to the upper frame 13 .

The lower frame 14 is a plate material that connects the lower portions of the pair of side frames 11 and 12 to each other along the vertical direction. Both ends of the lower frame 14 in the left-right direction are superimposed on the rear flanges of the plate portions 11b and 12b, and the plate portions 11b and 12b are welded at a plurality of points in the vertical direction.

The wires 15 , 16 , 17 are for supporting a back pad as a cushion material attached to the back frame 3 . Two wires 15 are bridged between an upper frame (first frame) 13 and a lower frame (second frame) 14 which are arranged apart from each other in the vertical direction. Both ends of the wire 15 are welded to the upper frame 13 and the lower frame 14, respectively. Both ends of the wire 16 are welded to the cylindrical portion 11a of the side frame (first frame) 11 and the cylindrical portion 12a of the side frame (second frame) 12, respectively.

Both ends of the wire 17 are welded to rear flanges of the plate portions 11b and 12b of the side frames 11 and 12, respectively. Since the flanges of the plate portions 11b and 12b are formed on flat surfaces that allow line contact with both ends of the wire 17, it is easy to secure welding strength between the wire 17 and the plate portions 11b and 12b. Further, even if the distance between the plate portions 11b and 12b and the length of the wire 17 vary due to manufacturing errors, etc., the wire 17 can be shifted in the left-right direction with respect to the flanges of the plate portions 11b and 12b. wire 17 can be welded to.

Next, with reference to FIGS. 2(a) and 2(b) in addition to FIG. 1, welding portions between the wires 15 and 16 and the frame body 10 will be described. In FIGS. 2(a) and 2(b), the side frame 12, the upper frame 13, and the like, which are visible on the back side of the paper, are omitted, and the central portions of the main bodies 15a and 16a are omitted.

As shown in FIGS. 1 and 2A, the wire 15 includes a main body portion 15a extending in the vertical direction (first direction), a bent end portion 15b connected to the upper end of the main body portion 15a, and the lower end of the main body portion 15a. and a straight end portion 15c that continues to the . The bent end portion 15 b is a linear portion bent in the left-right direction (second direction) with respect to the main body portion 15 a and formed substantially parallel to the upper frame 13 . Specifically, the bent end portion 15b is bent substantially perpendicularly to the right with respect to the main body portion 15a. This bent end portion 15 b is welded to the upper frame 13 .

The upper frame 13 has an inclined surface 13a that inclines inward (toward the lower frame 14) in the vertical direction. The inclined surface 13 a is part of the outer peripheral surface (columnar surface) of the cylindrical upper frame 13 . More specifically, the inclined surface 13a is a part of the outer peripheral surface of the upper frame 13 that extends rearward from the inner edge in the vertical direction closest to the lower frame 14 to a quarter of the circumference. The bent end portion 15b is welded to the inclined surface 13a to form a first welded portion 21 between the inclined surface 13a and the bent end portion 15b.

A lower end portion of the body portion 15a bends forward from the central portion of the body portion 15a toward the front of the lower frame 14 while avoiding the lower frame 14 . The straight end portion 15c extends downward from the lower end portion of the body portion 15a. The straight end portion 15c is slightly slanted forward with respect to the central portion of the body portion 15a. The straight end portion 15c is welded to the central portion of the lower frame 14 in the left-right direction.

A central portion of the lower frame 14 is formed to have a substantially uniform cross-sectional shape in the left-right direction. The central portion of the lower frame 14 includes a vertically extending web 14a, a first flange 14b extending forward from the upper edge of the web 14a, a second flange 14c extending forward from the lower edge of the web 14a, and a second flange 14c. and a flat portion 14d bent downward from the front edge of the . The rigidity of the central portion of the lower frame 14 can be ensured by the web 14a, the first flange 14b and the second flange 14c.

The plane portion 14d has a cross section perpendicular to the left-right direction formed in a linear shape extending in the up-down direction. The straight end portion 15c is welded to the flat portion 14d to form a second welded portion 22 between the flat portion 14d and the straight end portion 15c. The second welded portion 22 is formed along the vertical direction along which the linear end portion 15c extends, and is long in the vertical direction. The second welded portion 22 is located away from the tip 15d of the straight end portion 15c.

As shown in FIGS. 1 and 2B, the wire 16 includes a body portion 16a extending in the left-right direction (first direction), a bent end portion 16b connected to the right end of the body portion 16a, and the left end of the body portion 16a. and a curved end 16c that continues to the . The bent end portion 16b is a linear portion bent in the vertical direction (second direction) with respect to the main body portion 16a, and is formed substantially parallel to the cylindrical portion 11a of the side frame 11. As shown in FIG. Specifically, the bent end portion 16b is bent substantially perpendicularly downward with respect to the main body portion 16a. This bent end portion 16b is welded to the cylindrical portion 11a.

The cylindrical portion 11a has an inclined surface 11c that inclines inward in the left-right direction (toward the side frame 12). The inclined surface 11c is part of the outer peripheral surface (cylindrical surface) of the cylindrical portion 11a. More specifically, the inclined surface 11c is a part of the outer peripheral surface of the cylindrical portion 11a that extends forward from the left-right inner end portion closest to the side frame 12 for a quarter of the circumference. The bent end portion 16b is welded to the inclined surface 11c to form a first welded portion 23 between the inclined surface 11c and the bent end portion 16b.

The curved end portion 16c is a portion orthogonal to the cylindrical portion 12a of the side frame 12 when viewed in the front-rear direction shown in FIG. 1, and overlaps in front of the cylindrical portion 12a. The curved end portion 16c curves along the outer peripheral surface of the cylindrical portion 12a when viewed in the vertical direction shown in FIG. The curved end portion 16c is curved so as to make line contact with a portion of the front side of the outer peripheral surface of the cylindrical portion 12a. The curved end portion 16c is welded to the cylindrical portion 12a to form a third welded portion 24 between the outer peripheral surface of the cylindrical portion 12a and the curved end portion 16c. The distance between the outer peripheral surface of the cylindrical portion 12a and the curved end portion 16c gradually increases as the distance from the third welded portion 24 increases in the circumferential direction of the cylindrical portion 12a.

According to the seat frame 1 (back frame 3) as described above, the inclined surface 13a of the upper frame 13 (first frame) extending in the left-right direction (arrow LR direction, second direction) is different from the upper frame 13. A bent end portion 15b inclined in the vertical direction (direction of arrows UD, first direction) toward the lower frame 14 (second frame) and bent in the horizontal direction with respect to the main body portion 15a forms the inclined surface 13a. Welded. Therefore, even if the distance between the upper frame 13 and the lower frame 14 and the length between the ends of the wire 15 vary due to manufacturing errors, the bending end 15b can be vertically displaced along the inclined surface 13a. Variations can be absorbed to form the first welded portion 21 between the inclined surface 13a and the bent end portion 15b.

Further, since the bent end portion 15b is provided by bending in the left-right direction along which the upper frame 13 extends, the contact portion between the bent end portion 15b and the inclined surface 13a during welding (when forming the first welded portion 21) length can be secured. As a result, the length of the first welded portion 21 formed by welding the contact portion between the bent end portion 15b and the inclined surface 13a can be secured, so that the welding strength of the first welded portion 21 can be secured. Note that the contact portion in this specification may be a gap between the two members that does not affect welding even if the two members are not in strict contact with each other.

Similarly, the inclined surface 11c of the cylindrical portion 11a of the side frame 11 (first frame) extending in the vertical direction (arrow UD direction, second direction) is different from the side frame 11 in the horizontal direction (arrow LR direction, A bent end portion 16b inclined toward the side frame 12 (second frame) away in the first direction) and bent vertically with respect to the main body portion 16a is welded to the inclined surface 11c. Therefore, even if the spacing between the side frames 11 and 12 or the length between the ends of the wire 16 varies due to manufacturing errors, the variation is absorbed by shifting the bent end 16b in the left-right direction along the inclined surface 11c. Then, a first welded portion 23 can be formed between the inclined surface 11c and the bent end portion 16b. Furthermore, since the contact portion between the bent end portion 16b and the inclined surface 11c during welding and the length of the first welded portion 23 can be secured, the welding strength of the first welded portion 23 can be secured.

Since the inclined surfaces 11c and 13a are part of the cylindrical surface, the ends of the wire perpendicular to the inclined surfaces 11c and 13a (cylindrical surfaces) are curved along the inclined surfaces 11c and 13a, and the ends are bent into the inclined surfaces 11c and 13a. When welding to 13a, the length of the contact portion between the end of the wire and the inclined surfaces 11c and 13a tends to vary unless the end of the wire is bent with high precision. In particular, when the bent ends of the wires are shifted along the inclined surfaces 11c and 13a, the lengths of the contact portions between the ends of the wires and the inclined surfaces 11c and 13a vary greatly.

On the other hand, in the present embodiment, a bent end portion 16b bent in the vertical direction is welded to the inclined surface 11c inclined inward in the horizontal direction, and the inclined surface inclined inward in the vertical direction. A bent end portion 15b bent in the left-right direction is welded to 13a. Therefore, even if the bent ends 15b and 16b are displaced along the inclined surfaces 11c and 13a, variations in the length of the contact portions between the inclined surfaces 11c and 13a and the bent ends 15b and 16b can be suppressed. As a result, variations in welding strength between the inclined surfaces 11c, 13a and the bent ends 15b, 16b can be suppressed.

In particular, the bent end portion 15b is substantially parallel to the upper frame 13, and the bent end portion 16b is substantially parallel to the cylindrical portion 11a. Therefore, regardless of the contact position of the bent ends 15b, 16b with respect to the inclined surfaces 11c, 13a, the length of the contact portion between the inclined surfaces 11c, 13a and the bent ends 15b, 16b can be made substantially constant. As a result, variations in welding strength between the inclined surfaces 11c, 13a and the bent ends 15b, 16b can be further suppressed.

The curved end portion 16c of the wire 16 is curved along the outer peripheral surface (cylindrical surface) of the cylindrical portion 12a. Since the bent end portion 16b and the inclined surface 11c can absorb, the contact position between the curved end portion 16c and the cylindrical portion 12a can be kept substantially constant. Therefore, variations in the length of the contact portion between the curved end portion 16c and the cylindrical portion 12a and the length of the third weld portion 24 can be suppressed, so variations in the welding strength between the curved end portion 16c and the cylindrical portion 12a can be suppressed. .

In addition, even if the welding strength between the curved end portion 16c and the cylindrical portion 12a varies a little, as described above, while ensuring the welding strength between the inclined surface 11c and the bent end portion 16b, the variation in the welding strength is sufficiently suppressed. can. As a result, even if one end of the wire 16 is the curved end portion 16c, if the other end of the wire 16 is the bent end portion 16b, the welding strength between the wire 16 and the frame body 10 can be sufficiently secured, and the welding can be performed. Variation in strength can be sufficiently suppressed.

On the other hand, a linear end portion 15c extending in the vertical direction (first direction) is provided at the end portion of the wire 15 opposite to the bent end portion 15b. The plane portion 14d between which the second welded portion 22 is formed with the linear end portion 15c has a linear cross section perpendicular to the left-right direction (second direction) extending vertically. Therefore, when the flat portion 14d and the straight end portion 15c are welded together (when the second weld portion 22 is formed), the straight end portion 15c is displaced vertically with respect to the flat portion 14d so that the upper frame 13 and the lower frame 14 are welded together. , and variations in the length of the wire 15 can be absorbed to form the second welded portion 22 . In addition, the combination of the flat portion 14d and the straight end portion 15c and the combination of the inclined surface 13a and the bent end portion 15b can reduce variations in the distance between the upper frame 13 and the lower frame 14 and the length of the wire 15 to both ends of the wire 15. It can be dispersed and absorbed on the part side.

Next, a method of welding the wires 15, 16, 17 to the frame body 10, that is, a method of manufacturing the back frame 3 will be described with reference to FIGS. 3 to 6(b). In FIG. 4, the side frame 12 and the like seen on the back side of the paper are omitted, and the central portion of the main body portion 15a is omitted. 5(a) to 6(b), the upper frame 13, the first jig 33 and the like, which are visible on the back side of the paper, are omitted. 5(a) to 6(b) are schematically illustrated by shortening the space between the side frames 11 and 12 and the body portion 16a.

As shown in FIG. 3, while the frame body 10 and the wires 15, 16 and 17 are held and positioned by the welding jig 30, the contact portions between the frame body 10 and the wires 15, 16 and 17 are arc-welded. to manufacture the back frame 3. The method of welding the frame body 10 and the wires 15, 16, 17 is not limited to arc welding, but may be resistance welding, laser welding, or the like.

The welding jig 30 includes a jig body 31 that holds the frame body 10 , first jigs 32 , 33 , 34 that hold main body portions 15 a and 16 a of the wires 15 and 16 and the wire 17 , respectively, and bent end portions of the wire 15 . A second jig 35 that holds the wire 15b and a third jig 36 that holds the bent end portion 16b of the wire 16 are provided. The jig body 31 holds the frame body 10 with the front of the back frame 3 (frame body 10 ) facing vertically upward. That is, the direction of arrow F shown in FIGS. 3 to 6 is vertically upward, and the direction of arrow B is vertically downward.

The first jigs 32 , 33 , 34 are portions protruding from the jig main body 31 in the arrow F direction (vertically upward) and fixed to the jig main body 31 . A U-shaped groove is formed in the upper end face of the first jig 32 (the end face in the direction of arrow F) along the direction of arrow UD (the vertical direction of the frame body 10). By inserting the main body portion 15a of the wire 15 into the groove of the first jig 32, the main body portion 15a can be moved in the direction of the arrow UD with respect to the frame body 10, and the direction of the arrow LR (of the frame body 10). left-right direction).

U-shaped grooves are formed in the upper end surfaces of the first jigs 33 and 34 along the direction of the arrows LR. By inserting the body portion 16a of the wire 16 into the groove of the first jig 33, the body portion 16a can be moved in the direction of the arrows LR and positioned in the direction of the arrows UD with respect to the frame body . Similarly, by inserting the wire 17 into the groove of the first jig 34, the wire 17 can be moved relative to the frame body 10 in the direction of the arrows LR and positioned in the direction of the arrows UD.

As shown in FIGS. 3 and 4, the second jig 35 is a substantially rectangular parallelepiped portion projecting from the jig main body 31 in the arrow F direction. The second jig 35 is moved in the direction of arrow UD with respect to the jig body 31 by a moving mechanism (not shown). In the second jig 35, a stepped notch 35a is formed by notching the corner between the end face in the direction of arrow F and the side face in the direction of arrow U (the corner on the upper frame 13 side) along the direction of arrows LR. ing.

In order to weld the wire 15 to the frame body 10 (the upper frame 13 and the lower frame 14), first, the frame body 10 is fixed to the jig body 31, the body portion 15a is held by the first jig 32, and the frame body 10 is welded. , the wire 15 is positioned in the direction of the arrows LR (first jig step). When the main body portion 15a is held by the first jig 32, the bent end portion 15b is placed on the notch portion 35a of the second jig 35 separated from the upper frame 13, and the straight end portion 15c is placed on the flat portion 14d of the lower frame 14. put it on

With the body portion 15a held by the first jig 32 (after the first jig step), the second jig 35 is moved in the direction of arrow U, and the notch portion 35a of the second jig 35 and the inclined surface 13a of the upper frame 13 are separated. and sandwich the bent end 15b in the direction of the arrow UD (second jig step). When the bent end portion 15b placed on the second jig 35 is moved in the direction of the arrow U, the straight end portion 15c placed on the plane portion 14d also moves in the direction of the arrow U. In this manner, the wire 15 is positioned in the arrow UD direction with respect to the frame body 10 by sandwiching the bent end portion 15b between the second jig 35 and the inclined surface 13a. Further, since the bent end portion 15b contacts the inclined surface 13a inclined toward the lower frame 14, and the straight end portion 15c rests on the flat portion 14d, the wire 15 is directed to the frame main body 10 in the direction of the arrow FB. is positioned at

With the bent end portion 15b sandwiched between the second jig 35 and the inclined surface 13a (after the second jig step), the contact portion between the bent end portion 15b and the inclined surface 13a is welded, and the contact portion between them is welded. A first welded portion 21 (see FIG. 2A) is formed, and a second welded portion 22 is formed by welding a contact portion between the linear end portion 15c and the planar portion 14d (welding step). During welding (when forming the first welded portion 21 and the second welded portion 22), the wire 15 is positioned in each direction with respect to the frame body 10 by the first jig 32 and the second jig 35. Welding work of the wire 15 to the main body 10 can be facilitated.

In particular, even if the distance between the upper frame 13 and the lower frame 14 and the length of the wire 15 vary, the second jig 35 presses the bent end portion 15b against the inclined surface 13a of the upper frame 13 so as to straighten the flat portion 14d. The first welded portion 21 and the second welded portion 22 can be formed with the end portion 15c shifted in the direction of the arrow UD. Thereby, the contact position between the bent end portion 15b and the inclined surface 13a during welding (the position where the first welded portion 21 is formed) can be made substantially constant. As a result, the welding operation between the inclined surface 13a and the bent end portion 15b can be facilitated.

Furthermore, even if the gap between the upper frame 13 and the lower frame 14 varies, by fixing the frame body 10 to the jig body 31 with the upper frame 13 as a reference, the formation position of the first welded portion 21 can be adjusted with respect to the jig body 31. can be preset. This makes it easier to weld the inclined surface 13a and the bent end portion 15b. In addition, since the formation position of the first welded portion 21 is set in advance with respect to the jig main body 31, when the first welded portion 21 is formed by automatic welding by a robot or the like, the distance between the upper frame 13 and the lower frame 14 is reduced. It is possible to improve the accuracy of automatic welding without detecting variations in

Further, the formation position of the second welded portion 22 indicated by a two-dot chain line in FIG. 4 is located away from the tip 15d of the straight end portion 15c. By changing the distance from the second welded portion 22 to the tip 15d of the straight end portion 15c, variations in the distance between the upper frame 13 and the lower frame 14 and the length of the wire 15 can be absorbed. For example, the distance between the upper frame 13 and the lower frame 14 and the length of the wire 15 vary, and the position of the tip 15d with respect to the plane portion 14d changes between the position indicated by the solid line in FIG. 4 and the position indicated by the two-dot chain line. However, the formation position of the second welded portion 22 can be kept unchanged. As a result, the welding work between the linear end portion 15c and the flat portion 14d can be facilitated.

In particular, the formation position of the second welded portion 22 is set in advance with respect to the jig main body 31 . This makes it easier to weld the linear end portion 15c and the flat portion 14d. In addition, since the formation position of the second welded portion 22 is set in advance with respect to the jig body 31, when the second welded portion 22 is formed by automatic welding by a robot or the like, the distance between the upper frame 13 and the lower frame 14 is reduced. It is possible to improve the accuracy of automatic welding without detecting variations in

As shown in FIGS. 3 and 5A, the third jig 36 is a substantially rectangular parallelepiped portion projecting from the jig main body 31 in the arrow F direction. The third jig 36 restricts the movement of the bent end portion 16b in contact with the inclined surface 11c of the cylindrical portion 11a vertically downward (in the direction of arrow B). The third jig 36 moves in the arrow FB direction (vertical direction) with respect to the jig main body 31 by an elevation mechanism (not shown).

In the third jig 36, the corner between the side surface 36a in the direction of the arrow R (the side of the cylindrical portion 11a) and the end surface in the direction of the arrow F is cut in the direction of the arrow UD to form a first restricting surface 36b and a A second restricting surface 36c is formed. The side surface 36a slides against the cylindrical portion 11a (inclined surface 11c) when the third jig 36 is moved in the arrow FB direction while the cylindrical portion 11a is fixed to the jig body 31. FIG. That is, when the cylindrical portion 11a is fixed to the jig main body 31, the side surface 36a is on the tangential plane at the innermost portion of the inclined surface 11c in the direction of the arrow L. As shown in FIG.

The first restricting surface 36b is a flat surface that continues to the end of the side surface 36a in the arrow F direction and is perpendicular to the side surface 36a and the second restricting surface 36c. The dimension of the first restricting surface 36b in the direction of the arrows LR is set substantially equal to the diameter of the wire 16 (bent end 16b). The second restricting surface 36c is a flat surface that rises vertically from the end of the first restricting surface 36b in the direction of arrow L. As shown in FIG.

In order to weld the wire 16 to the frame body 10 (side frames 11 and 12), first, the frame body 10 is fixed to the jig body 31, the body portion 16a is held by the first jig 33, and the frame body 10 is welded. position the wire 16 in the direction of the arrow UD (first jig step). When the main body portion 16a is held by the first jig 33, the bent end portion 16b is placed on the first restricting surface 36b of the third jig 36, and the curved end portion 16c is placed on the cylindrical portion 12a. In addition, before placing the bent end portion 16b on the first restricting surface 36b, the third jig 36 is moved so that the bent end portion 16b placed on the first restricting surface 36b comes into contact with the innermost side of the inclined surface 11c in the direction of the arrow L. Move in the FB direction.

In the state shown in FIG. 5A, the bent end 16b is in contact with the innermost part of the inclined surface 11c in the direction of the arrow L, and the curved end 16c is not in contact with the uppermost part of the cylindrical part 12a in the vertical direction. The curved end portion 16c is in contact with the inner side in the arrow R direction (the cylindrical portion 11a side) of the uppermost portion. In this case, the third jig 36 is moved in the arrow F direction in the third jig process after the first jig process. When the third jig 36 moves in the arrow F direction from the state shown in FIG. 5A, the bent end portion 16b can move in the arrow R direction. Therefore, the curved end portion 16c moves in the direction of the arrow R along the inclination of the cylindrical portion 12a due to gravity, and the bent end portion 16b also moves in the direction of the arrow R to maintain contact with the inclined surface 11c.

As shown in FIG. 5B, the third jig 36 is moved until the curved end portion 16c contacts the uppermost portion of the cylindrical portion 12a. Even if the bent end portion 16b is placed on the inclined surface 11c inclined in the arrow L direction while facing the arrow F direction, the third jig 36 prevents the bent end portion 16b from moving in the arrow B direction along the inclined surface 11c. can be regulated. Therefore, it is possible to prevent the wire 16 from shifting in the direction of arrow L with respect to the frame body 10 due to movement of the bent end portion 16b in the direction of arrow B along the inclined surface 11c. As a result, the curved end portion 16c can be kept in contact with the uppermost portion of the cylindrical portion 12a. That is, the wire 16 can be positioned in the LR direction and the FB direction with respect to the frame body 10 .

The curved end portion 16c is brought into contact with the uppermost portion of the cylindrical portion 12a, and the movement of the curved end portion 16b in the direction of the arrow B is restricted by the third jig 36 (after the third jig step). The contact portion with the surface 11c is welded to form a first weld portion 23 (see FIG. 2(b)) therebetween. Further, the contact portion between the curved end portion 16c and the cylindrical portion 12a is welded to form the third weld portion 24 (welding step). During welding (when forming the first welded portion 23 and the third welded portion 24), the wire 16 is positioned in each direction with respect to the frame body 10 by the first jig 33 and the third jig 36. The welding operation of the wire 16 to the body 10 can be facilitated.

In the first jig step, the curved end portion 16c may be placed on the cylindrical portion 12a and the bent end portion 16b may be placed on the inclined surface 11c so that the curved end portion 16c is in contact with the uppermost portion of the cylindrical portion 12a. In this case, in the second jig step after the first jig step, the third jig 36 is moved in the arrow F direction until it contacts the bent end portion 16b.

In either case, since the curved end portion 16c is curved along the outer peripheral surface of the cylindrical portion 12a, a force (gravitational force) in the direction of the arrow B is applied from the curved end portion 16c to the cylindrical portion 12a. The curved end portion 16c can be easily brought into contact with the uppermost portion of the . Therefore, the contact position between the cylindrical portion 12a and the curved end portion 16c can be kept substantially constant during welding, and variations in the formation position of the third welded portion 24 can be suppressed. can be done.

Further, as shown in FIG. 6(a), the bent end portion 16b comes into contact with the most inner side of the inclined surface 11c in the direction of the arrow L, and the first restricting surface 36b prevents the bent end portion 16b from falling off downward. The shortest dimension of the wire 16 that is allowable for the spacing between the side frames 11 and 12 is when the curved end 16c contacts the top of the cylindrical portion 12a. If the wire 16 is shorter than this, the curved end 16c cannot be brought into contact with the top of the cylindrical portion 12a while the bent end 16b is brought into contact with the inclined surface 11c. As a result, the length of the contact portion between the cylindrical portion 12a and the curved end portion 16c cannot be sufficiently secured, and the welding strength of the third welded portion 24 cannot be sufficiently secured.

When the bent end portion 16b placed on the first restricting surface 36b contacts the innermost portion of the inclined surface 11c in the direction of the arrow L, the bent end portion 16b also contacts the second restricting surface 36c. Therefore, if the wire 16 is shorter than the allowable shortest dimension, when the curved end portion 16c is brought into contact with the uppermost portion of the cylindrical portion 12a, the bent end portion 16b interferes with the end surface of the third jig 36 in the arrow F direction. As a result, the bent end portion 16b cannot be placed on the first restricting surface 36b. In this way, it can be easily recognized by the third jig 36 that the length of the wire 16 is not within the allowable range with respect to the spacing between the side frames 11 and 12 .

As shown in FIG. 6B, when the bent end 16b in contact with the inclined surface 11c contacts the side surface 36a of the third jig 36, and the curved end 16c contacts the top of the cylindrical portion 12a, the side It is the longest dimension of wire 16 that is allowable for the spacing between frames 11,12. Therefore, when the curved end portion 16c is brought into contact with the uppermost portion of the cylindrical portion 12a, if the bent end portion 16b is at a position away from the side surface 36a in the direction of the arrow R, the space between the side frames 11 and 12 will be reduced. It is readily seen by the third fixture 36 that the length of 16 is not within an acceptable range.

If the wire 16 is longer than the permissible maximum dimension, the third jig 36 cannot restrict the movement of the bent end portion 16b in the arrow B direction while bringing the curved end portion 16c into contact with the uppermost portion of the cylindrical portion 12a. . As a result, the state in which the curved end portion 16c is in contact with the uppermost portion of the cylindrical portion 12a cannot be reliably maintained, and the length of the contact portion between the cylindrical portion 12a and the curved end portion 16c cannot be sufficiently secured, resulting in the third welding. A sufficient welding strength by the portion 24 cannot be ensured.

Next, a second embodiment will be described with reference to FIGS. 7(a), 7(b) and 7(c). In the first embodiment, only one end of the wire 16 is the bent end 16b. On the other hand, in the second embodiment, both ends of the wire 41 are the bent ends 16b and 42, respectively. The same reference numerals are given to the same parts as in the first embodiment, and the following description is omitted.

As shown in FIG. 7A, the back frame 40 has a wire 41 between the cylindrical portion 11a of the side frame 11 and the cylindrical portion 12a of the side frame 12, which are separated from each other in the direction of the arrows LR (first direction). is bridged. The wire 41 includes a body portion 16a extending in the direction of arrows LR, a bent end portion 16b connected to the end of the body portion 16a in the direction of arrow R, and a bent end connected to the end of the body portion 16a in the direction of arrow L. 42 and .

The bent end portion 42 is a linear portion bent in the direction of the arrow UD (second direction) with respect to the body portion 16a, and is formed substantially parallel to the cylindrical portion 12a. Specifically, the bent end portion 42 is bent substantially perpendicularly in the direction of arrow D with respect to the main body portion 16a. This bent end portion 42 is welded to the cylindrical portion 12a.

The cylindrical portion 12a has an inclined surface 12c that inclines inward (toward the side frame 11) in the direction of the arrows LR. The inclined surface 12c is part of the outer peripheral surface (cylindrical surface) of the cylindrical portion 12a. More specifically, the inclined surface 12c is a quarter portion of the outer peripheral surface of the cylindrical portion 12a extending in the arrow F direction from the end closest to the side frame 11 in the arrow R direction. The bent end portion 42 is welded to the inclined surface 12 c to form a first welded portion 43 between the inclined surface 12 c and the bent end portion 42 . The first welded portion 43 is formed similarly to the first welded portion 23 formed between the inclined surface 11c and the bent end portion 16b.

According to the back frame 40, even if the interval between the side frames 11 and 12 and the length between the ends of the wire 41 vary due to manufacturing errors, etc., the inclined surface 11c can be welded. , 12c, the bent ends 16b, 42 can be displaced in the direction of the arrows LR. As a result, the variations can be absorbed and the first welded portions 23, 43 can be formed between the inclined surfaces 11c, 12c and the bent ends 16b, 42, respectively. Furthermore, since the contact portions between the bent end portions 16b, 42 and the inclined surfaces 11c, 12c and the length of the first welded portions 23, 43 can be secured during welding, the welding strength of the first welded portions 23, 43 can be secured. can.

In particular, since the wire 41 has the bent ends 16b and 42 at both ends thereof, variations in the interval between the side frames 11 and 12 and the length between the wire 41 and the wire 41 are dispersed at both ends of the wire 41 during welding. can be absorbed by Furthermore, compared to the case where the wire 41 has only one of the bent ends 16b and 42, the welding strength between the side frames 11 and 12 and both ends of the wire 41 can be ensured. , 12 can be further improved.

As shown in FIGS. 7B and 7C, the welding jig for holding the side frames 11 and 12 and the wire 41 during welding consists of a jig main body 31 (see FIG. 3) and a first jig 33 (see FIG. 3). 3), a third jig 45 that restricts the movement of the bent end 16b in contact with the inclined surface 11c vertically downward (arrow B direction), and a vertically downward movement of the bent end 42 in contact with the inclined surface 12c (arrow B). and a third jig 46 that restricts movement in the B direction).

The third jig 45 is configured in the same manner as the third jig 36 of the first embodiment, except that the first regulation surface 45b is vertically downwardly inclined from the second regulation surface 36c toward the side surface 36a. Also, the third jig 46 is formed symmetrically with respect to the third jig 45 in the direction of the arrows LR. The third jigs 45 and 46 move together in the direction of the arrow FB so that the heights of the third jigs 45 and 46 become the same.

In order to weld the wires 41 to the side frames 11 and 12, first, the side frames 11 and 12 are attached to the jig main body 31 (FIG. 3) so that the arrow F direction faces vertically upward and the inclined surfaces 11c and 12c face vertically upward. (see FIG. 3), and the main body portion 16a is held by the first jig 33 (see FIG. 3) (first jig step). Before holding the body portion 16a on the first jig 33, the bent ends 16b and 42 placed on the first restricting surfaces 45b and 46b are brought into contact with the innermost sides of the inclined surfaces 11c and 12c in the direction of the arrows LR. , the third jigs 45 and 46 are moved in the arrow FB direction.

When the main body portion 16a is held by the first jig 33, the bent end portion 16b is placed on the first restricting surface 45b or the inclined surface 11c, and the bent end portion 42 is placed on the first restricting surface 46b or the inclined surface 12c. In the description of FIG. 7B, the bent end portion 16b is placed on the first restricting surface 45b, and the bent end portion 42 is placed on the inclined surface 12c.

When the third jigs 45 and 46 are moved in the direction of arrow F from the state shown in FIG. 7B, the bent end portion 42 moves in the direction of arrow R along the inclined surface 12c, and the inclination of the first restricting surface 45b increases. , the bent end portion 16b moves in the direction of the arrow R, and the contact between the bent end portion 16b and the inclined surface 11c is maintained. As shown in FIG. 7C, while the bent end portion 16b contacts both the inclined surface 11c and the third jig 45, the bent end portion 42 contacts both the inclined surface 12c and the third jig 46. The third jigs 45, 46 are moved.

As a result, even if the bent ends 16b and 42 are placed on the slanted surfaces 11c and 12c that face the direction of the arrow F and are slanted inward in the direction of the arrows LR, the bent ends 16b and 42 are placed along the slanted surfaces 11c and 12c. Movement of 42 in the direction of arrow B can be restricted by third jigs 45 and 46 . As a result, the wire 41 can be positioned with respect to the side frames 11 and 12 in the LR and FB directions.

The third jigs 45 and 46 may be moved in the arrow F direction with the bent end 16b placed on the inclined surface 11c and the bent end 42 placed on the first restricting surface 46b. In this case also, the wire 41 can be moved in the direction of the arrow L along the inclination of the inclined surface 11c and the first restricting surface 46b, and the wire 41 can be moved in the LR and F- directions with respect to the side frames 11 and 12. It can be positioned in the B direction.

In addition, since the first restricting surfaces 45b, 46b are inclined toward the inclined surfaces 11c, 12c, the bent ends 16b, 42 moving in the direction of the arrow B along the first restricting surfaces 45b, 46b are moved toward the inclined surfaces 11c, 46b. 12c can be reliably contacted. As a result, the wires 41 can be easily positioned with respect to the side frames 11 and 12 in the LR and FB directions.

In this way, with the wire 41 positioned in each direction with respect to the side frames 11 and 12 by the first jig 33 and the third jigs 45 and 46 (after the third jig step), the bent end portion 16b and the inclined surface 11c are bent. are welded to form a first weld 23 therebetween. Further, the contact portion between the bent end portion 42 and the inclined surface 12c is welded to form a first weld portion 43 therebetween (welding step). By using the first jig 33 and the third jigs 45 and 46 in this way, the welding operation of the wire 41 to the side frames 11 and 12 can be facilitated.

In particular, since the third jigs 45 and 46 are formed symmetrically, the body portion 16a can be adjusted by bringing the bent ends 16b and 42 into contact with the third jigs 45 and 46 and the inclined surfaces 11c and 12c, respectively. can be substantially parallel to the direction of the arrows LR. As a result, it is possible to prevent the wire 41 from being welded to the side frames 11 and 12 in a state of being inclined with respect to the direction of the arrows LR.

If the interval between the bent ends 16b and 42 is smaller than the interval between the second restricting surfaces 36c and 46c of the third jigs 45 and 46, both the bent ends 16b and 42 are formed on the inclined surfaces 11c and 12c. Since the wire 41 cannot be brought into contact, the wire 41 is regarded as a defective product. When the interval between the bent ends 16b and 42 is larger than the interval between the side surfaces 36a and 46a of the third jigs 45 and 46, both the bent ends 16b and 42 are brought into contact with the third jigs 45 and 46. Therefore, the wire 41 is regarded as a defective product. Thus, it is possible to easily determine whether the wire 41 is defective or not by the third jigs 45 and 46 .

Next, a third embodiment will be described with reference to FIGS. 8(a), 8(b) and 8(c). In the second embodiment, the method of welding the wire 41 to the side frames 11 and 12 using the third jigs 45 and 46 has been described. In contrast, in the third embodiment, a method of welding the wire 41 to the side frames 11 and 12 using the third jigs 51 and 52 will be described. The same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description below is omitted.

As shown in FIG. 8A, the welding jig for holding the side frames 11 and 12 and the wire 41 during welding includes a jig body 31 (see FIG. 3), a first jig 33 (see FIG. 3), and side A third jig 51 provided on the frame 12 side and a third jig 52 provided on the side frame 11 side are provided. The side frames 11 and 12 are fixed to the jig main body 31 so that the arrow F direction faces vertically downward and the inclined surfaces 11c and 12c face vertically downward.

Since the third jig 51 and the third jig 52 are formed symmetrically, the third jig 51 will be mainly described below, and the description of the third jig 52 will be partially omitted. The third jig 51 is a portion protruding in the arrow B direction from the jig main body 31 . The third jig 51 restricts the movement of the bent end portion 42 in contact with the inclined surface 12c vertically downward (in the direction of the arrow F). The third jig 51 moves in the arrow FB direction (vertical direction) with respect to the jig main body 31 by an elevating mechanism (not shown).

The third jig 51 includes a facing surface 51a facing the cylindrical portion 12a in the arrow FB direction, a curved surface 51b curved from the facing surface 51a in the arrow R direction and the arrow B direction, and an inclined surface 12c that is closest to the arrow R direction. and a second restricting surface 51c with which the bent end portion 42 in contact with the inner side of the second restricting surface 51c can contact. The third jig 52 includes a facing surface 52a facing the cylindrical portion 11a in the arrow FB direction, a curved surface 52b curved from the facing surface 52a in the arrow L direction and the arrow B direction, and an inclined surface 11c extending in the arrow L direction. and a second restricting surface 52c with which the bent end portion 16b in contact with the inner side of the .

The facing surface 51a is formed substantially perpendicular to the arrow FB direction. The second restricting surface 51c is formed substantially the same as the second restricting surface 46c in the second embodiment. The radial dimension of the cylindrical portion 12a between the curved surface 51b and the inclined surface 12c gradually increases from the facing surface 51a toward the second restricting surface 51c. The radial dimension (the dimension in the direction of arrows LR) between the curved surface 51b and the inclined surface 12c at the boundary between the curved surface 51b and the second restricting surface 51c is set substantially equal to the diameter of the bent end .

In order to weld the wires 41 to the side frames 11 and 12, the side frames 11 and 12 are fixed to the jig main body 31 (see FIG. 3) so that the arrow B direction faces vertically upward, and the first jig 33 (see FIG. 3) is ) to hold the body portion 16a (first jig step). Before this first jig step, the bent ends 16b and 42 are placed on the curved surfaces 51b and 52b, respectively, and the facing surfaces 51a and 52a of the third jigs 51 and 52 are sufficiently separated from the cylindrical portions 11a and 12a. The third jigs 51 and 52 are moved. After the first jig step, the third jigs 51 and 52 symmetrical in the direction of arrows LR are moved in the direction of arrow B together.

As shown in FIG. 8(b), for example, when the wire 41 is shifted in the direction of arrow L with respect to the side frames 11 and 12, when the third jigs 51 and 52 are moved in the direction of arrow B, first, the inclined The bent end 42 is sandwiched between the surface 12c and the curved surface 51b. At this time, the bent end 16b placed on the curved surface 52b is not in contact with the inclined surface 11c.

When the third jigs 51 and 52 are further moved in the direction of arrow B from the state shown in FIG. It moves so as to be pushed out in the direction of arrow R where the radial dimension between it and the curved surface 51b is large. At the same time, the bent end portion 16b moves in the arrow R direction along the curved surface 52b.

Then, as shown in FIG. 8(c), when the bent end 16b is caught between the inclined surface 11c and the curved surface 52b, the movement of the third jigs 51 and 52 is stopped. As a result, the third jigs 51 and 52 can restrict the movement of the bent ends 16b and 42 in contact with the inclined surfaces 11c and 12c in the directions of the arrows FB and LR.

In this way, in a state where the wire 41 is positioned in each direction with respect to the side frames 11 and 12 by the first jig 33 and the third jigs 51 and 52 (after the third jig step), the bent end portion 16b and the inclined surface 11c are bent. are welded to form a first weld 23 therebetween. Further, the contact portion between the bent end portion 42 and the inclined surface 12c is welded to form a first weld portion 43 therebetween (welding step). By using the first jig 33 and the third jigs 51 and 52, welding work of the wire 41 to the side frames 11 and 12 can be facilitated.

In the welding process, the bent ends 16b and 42 are welded to the inclined surfaces 11c and 12c at positions away from the third jigs 51 and 52 in the direction of the arrows UD. The welding operation can be facilitated compared to the case where the bent ends 16b and 42 are welded to the inclined surfaces 11c and 12c in the narrow gaps between the cylindrical portions 11a and 12a and the third jigs 51 and 52, respectively.

In the third jig step, the bent end portion 42 is sandwiched between the inclined surface 12c and the curved surface 51b, and the bent end portion 16b is sandwiched between the inclined surface 11c and the curved surface 52b. 52 movement can be stopped. Therefore, it is possible to prevent the welding positions of the bent ends 16b and 42 from changing with respect to the inclined surfaces 11c and 12c due to excessive movement of the third jigs 51 and 52. FIG.

The present invention has been described above based on the embodiments, but the present invention is not limited to the above-described embodiments, and it is easily understood that various modifications and improvements are possible without departing from the scope of the present invention. It can be inferred. The shapes of the side frames 11 and 12, the upper frame 13, and the lower frame 14 may be changed as appropriate. For example, the inclined surfaces 11c, 12c, and 13a are not limited to being part of the cylindrical surface, and the inclined surfaces may be formed flat.

In the above-described first embodiment, the arrow LR direction is the first direction, the arrow UD direction is the second direction, the side frame 11 is the first frame, and the side frame 12 is the second frame. Although the present invention has been described with the D direction as the first direction, the arrow LR directions as the second direction, the upper frame 13 as the first frame, and the lower frame 14 as the second frame, the present invention is not necessarily limited to this. isn't it. A first frame and a second frame extending in the second direction may be arranged apart from each other in the first direction, and the side frame 12 may be the first frame and the side frame 11 may be the second frame. Alternatively, the lower frame 14 may be the first frame and the upper frame 13 may be the second frame. In addition, each part of the frame main body 10 of the back frame 3 is not limited to the first frame and the second frame, and each part of the cushion frame 2 may be the first frame and the second frame.

Furthermore, at least one of the first frame and the second frame may have an inclined surface to which the bent end portion is welded. Both frames 12) may be provided with inclined surfaces. Further, when only one of the first frame and the second frame is provided with an inclined surface, the other of the first frame and the second frame may be provided with a flat portion whose straight end is welded, or a cylindrical portion whose curved end is welded. You can set up a department. For example, the lower frame 14 may be cylindrical and provided with an inclined surface. Alternatively, the side frame 12 may be formed into a rectangular tubular shape and the flat portion may be provided on the side frame 12 .

Moreover, if the body portions 15a and 16a of the wires 15 and 16 extend entirely in the first direction, the body portions 15a and 16a are not limited to being straight, and the body portions 15a and 16a are partially bent. can be For example, the body portions 15a and 16a may be formed in a wavy shape.

In the above embodiment, a case where the seat frame 1 is mounted on a vehicle such as an automobile has been described, but the present invention is not necessarily limited to this. The seat frame 1 may be mounted on vehicles other than automobiles, such as industrial vehicles, railroad vehicles, ships, and aircraft. Also, the seat frame 1 may be provided on a seat placed indoors or outdoors other than a vehicle.

The shapes of the first jigs 32, 33, 34, the second jig 35, and the third jigs 36, 45, 46, 51, 52 described in the above embodiments may be changed as appropriate. Also, the wires 15, 16, 17, 41 held by the worker are attached to the frame main body 10 without using the first jigs 32, 33, 34, the second jig 35, and the third jigs 36, 45, 46, 51, 52. It can be welded.

1 seat frame 10 frame body 11, 12 side frame (first frame or second frame)
11a, 12a cylindrical portion 11c, 12c, 13a inclined surface 13 upper frame (first frame or second frame)
14 Lower frame (1st frame or 2nd frame)
14d plane portion 15, 16, 17, 41 wire 15a, 16a body portion 15b, 16b, 42 bent end portion 15c straight end portion 15d tip 16c curved end portion 21, 23, 43 first welded portion 22 second welded portion 24 second 3 welding part 31 jig body 32, 33, 34 first jig 35 second jig 36, 45, 46, 51, 52 third jig

Claims (6)

a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction;
a wire whose both ends are welded to the first frame and the second frame, respectively;
one of the first frame and the second frame has an inclined surface that inclines toward the other;
the other of the first frame and the second frame has a cylindrical portion extending in the second direction;
The wire has a main body portion extending in the first direction;
a bent end bent in the second direction with respect to the main body;
a curved end curved along the outer peripheral surface of the cylindrical portion as viewed from the second direction and curved in an arc so as to be in line contact with a portion of the outer peripheral surface of the cylindrical portion;
A first weld is formed between the inclined surface and the bent end,
A seat frame, wherein a third welded portion is formed between the outer peripheral surface of the cylindrical portion and the curved end portion. 2. The seat frame according to claim 1, wherein said inclined surface is part of a cylindrical surface. In the state in which the third welded portion is formed, the outer circumference of the cylindrical portion increases as it separates from the portion where the curved end portion and part of the outer peripheral surface of the cylindrical portion are in line contact to both sides in the circumferential direction of the cylindrical portion. 3. A seat frame according to claim 1 or 2, wherein the distance between the surface and the curved end gradually increases. a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; and both ends of which are welded to the first frame and the second frame, respectively. A method of manufacturing a seat frame comprising:
each of the first frame and the second frame includes an inclined surface that inclines toward the inside of each other;
the wire includes a main body portion extending in the first direction and bent end portions provided at both ends of the wire and bent in the second direction with respect to the main body portion;
In a state in which the frame body is fixed to the jig body with the inclined surface directed in the vertical direction, the body portion is positioned in the second direction while being movable in the first direction with respect to the frame body by a first jig. a first jig step to
After the first jig step, a pair of fourth jigs, which are symmetrically formed in the first direction and move vertically in conjunction with each other, move the bent end of the wire, which is in contact with the inclined surface at each end of the wire. a fourth jig step for regulating downward movement of the part;
After the fourth jig step, a welding step of welding the bent end portions of both ends of the wire to the inclined surface to form a first weld portion. Production method. a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; and both ends of which are welded to the first frame and the second frame, respectively. A method of manufacturing a seat frame comprising:
one of the first frame and the second frame has an inclined surface that inclines toward the other;
the other of the first frame and the second frame has a planar portion whose cross section perpendicular to the second direction is formed in a straight line extending in the first direction;
the wire includes a body portion extending in the first direction, a bent end portion bent in the second direction with respect to the body portion, and a straight end portion extending in the first direction;
a first jig step of positioning the main body in the second direction while allowing the main body to move in the first direction with respect to the frame main body with a first jig in a state where the frame main body is fixed to the jig main body;
After the first jig step, a second jig step of sandwiching the bent end portion in the first direction between the second jig and the inclined surface;
After the second jig step, the bent end portion is welded to the inclined surface to form a first weld portion, and the linear end portion is welded to the flat portion at a preset position with respect to the jig body. and a welding step of forming a second welded portion. a frame body having a first frame and a second frame spaced apart from each other in a first direction and extending in a second direction perpendicular to the first direction; and both ends of which are welded to the first frame and the second frame, respectively. A method of manufacturing a seat frame comprising:
one of the first frame and the second frame has an inclined surface that inclines toward the other;
the other of the first frame and the second frame has a cylindrical portion extending in the second direction;
The wire has a main body portion extending in the first direction, a bent end portion bent in the second direction with respect to the main body portion, and curved along an outer peripheral surface of the cylindrical portion when viewed from the second direction. a curved end;
With the frame main body fixed to the jig main body with the inclined surface facing upward, the curved end portion is placed on the cylindrical portion, and the main body portion is moved to the frame main body by the first jig. a first jig step of positioning in the second direction while allowing movement in the direction;
After the first jig step, with the curved end in contact with the uppermost portion of the cylindrical portion, the bent end in contact with the inclined surface is moved downward by a vertically movable third jig. A third jig step for regulating
After the third jig step, a welding step of welding the bent end portion to the inclined surface to form a first weld portion and welding the curved end portion to the cylindrical portion to form a third weld portion; A method of manufacturing a seat frame, comprising:

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