Vehicle body fastener structure

Abstract

The purpose of the present invention is to provide a vehicle body fastening section structure in which the rigidity of a fastening section between a vehicle body frame and a sub-frame is not reduced even if a nut is joined to the vehicle body frame by spot welding, and the stability of welding quality can be maintained. A vehicle body fastening portion structure according to the present invention comprises: a vehicle body frame; a sub-frame mounted on the vehicle body frame; a welding pipe nut coupled to the vehicle body frame; and a bolt that fastens the subframe to the welding tube nut, the welding tube nut having: a tube section that is inserted through the vehicle body frame from the outside; a coupling flange part which is formed on the base part of the tube part and is coupled to the outer surface of the vehicle body frame by spot welding; and a boss part which protrudes from the surface of the coupling flange part on the side opposite to the pipe part, the end surface of the boss part is provided with a seat surface, and the subframe abuts against and is fastened to the seat surface.

Description

Technical Field

[0001] The invention relates to a vehicle body fastening portion structure. Background Art

[0002] When the subframe is fastened to the vehicle body frame, if the rigidity of the fastening portion is increased, for example, when the subframe is a suspension cross member, the input from the road surface received by the suspension can be smoothly transmitted to the vehicle body side, thereby improving the delay of steering response and the like.

[0003] In the past, for example, the mounting portion of the suspension cross member abuts against the lower surface of the vehicle body frame and is fastened to a nut welded to the vehicle body frame by a bolt. The nut is often welded to the surface on the opposite side of the mounting portion of the suspension cross member through the vehicle body frame. In addition, a spot welding nut is often used as the nut.

[0004] When spot welding the spot welding nut to the vehicle body frame, the electrodes are clamped between the joint surface of the spot welding nut and the vehicle body frame, and the heat generated by the resistance is used to melt the inside of the joint. When the molten part is cooled, a nugget is formed, and the joint surface of the spot welding nut and the vehicle body frame are joined together through the nugget.

[0005] A depression (dent) caused by thermal deformation is formed in the portion of the body frame and the spot welding nut crimped by the electrode. In addition, a slightly raised indentation is formed around the depression. When the mounting portion of the suspension cross member is brought into contact with the body frame and fastened by bolts, the mounting portion is pressed against the indentation formed on the body frame side. Since the indentation is raised from the body frame, the mounting portion is fastened on the raised indentation.

[0006] When the mounting part is fastened on the raised indentation, the mounting part becomes a state where the portion other than the indentation is raised relative to the joint surface of the vehicle body frame, and the fastening rigidity is reduced. If the fastening rigidity is reduced, when the mounting part of the suspension cross member is twisted due to the suspension stroke or the vibration of the power unit (engine, motor), stress in the prying direction (orthogonal to the center line) is easily concentrated on the fastening part of the mounting part and the indentation.

[0007] The height of the indentation is not uniform at each spot weld. If the height of the indentation is high, the rigidity of the fastening portion is further reduced, which leads to reduced steering safety (steering stability), reduced ride comfort, and reduced steering responsiveness.

[0008] For example, Patent Document 1 (Patent No. 6337342) discloses a technique in which a pipe nut is inserted from below into a through hole formed in a vehicle body frame and protrudes, a flange formed at a base end is brought into contact with the lower surface of the vehicle body frame, and the outer periphery of the flange is joined by arc welding.

[0009] In the technology disclosed in this document, since substantially the entire surface of the flange portion formed at the base of the tube nut can be joined to the vehicle body frame, the rigidity of the fastening portion can be increased.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent No. 6337342 Summary of the invention

[0013] Technical problem to be solved by the invention

[0014] However, in the technology disclosed in Patent Document 1, the flange portion formed on the tube nut is connected to the vehicle body frame by arc welding. However, arc welding has a problem of poor stability of welding quality compared to spot welding.

[0015] In addition, arc welding generates spatter during welding. The flange portion is provided with a seat surface against which the mounting portion of the suspension cross member abuts. Therefore, during arc welding, it is necessary to protect the seat surface with a shielding material to prevent the attachment of spatter. In order to protect the seat surface provided on the flange portion with a shielding material, it is necessary to perform a process of installing and removing the shielding material before and after the arc welding process. In the technology disclosed in Patent Document 1, a process of installing and removing the shielding material is also required, which increases the working hours and reduces the production efficiency.

[0016] An object of the present invention is to provide a vehicle body fastening structure in which the rigidity of the fastening portion between the vehicle body frame and the subframe does not decrease even when the nut is fastened to the vehicle body frame by spot welding, the welding quality can be kept stable, and the productivity is good.

[0017] Technical solutions for solving technical problems

[0018] The vehicle body fastening structure of the present invention comprises: a vehicle body frame, which is provided on a vehicle body; a subframe, which has a mounting portion mounted on the vehicle body frame; a welding pipe nut, which is coupled to the vehicle body frame; and a bolt, which fastens the mounting portion of the subframe to the welding pipe nut, wherein the welding pipe nut comprises: a pipe portion, which is inserted through the vehicle body frame from the outside and has an internal thread portion screwed therein; and a coupling flange portion, which is formed at a base of the pipe portion and coupled to an outer surface of the vehicle body frame, wherein the mounting portion of the subframe is fastened to the welding pipe nut by a bolt screwed into the internal thread portion, wherein in the vehicle body fastening structure, the coupling flange portion is coupled to the outer surface of the vehicle body frame by spot welding, a boss portion is protrudingly provided on a surface of the coupling flange portion on a side opposite to the pipe portion across the coupling flange portion, a seat surface is provided on an end surface of the boss portion, and the mounting portion of the subframe abuts against the seat surface and is fastened by the bolt.

[0019] Effects of the Invention

[0020] According to the present invention, since the connecting flange formed at the base of the pipe portion provided at the welding pipe nut is connected to the outer surface of the vehicle body frame by spot welding, a boss portion is protrudingly provided on the surface of the connecting flange portion opposite to the pipe portion, the mounting portion of the subframe abuts on the boss portion to provide a seat surface, and the mounting portion is fastened to the seat surface by bolts, the mounting portion and the seat surface can be abutted and fastened without being affected by the indentation formed by spot welding. As a result, the rigidity of the fastening portion between the vehicle body frame and the subframe is not reduced, the stability of the welding quality can be maintained, and good productivity can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is an exploded perspective view of a vehicle body front frame and a suspension cross member according to the first embodiment.

[0022] Figure 2 It is the main part front view of the vehicle body front frame.

[0023] Figure 3 It is a perspective view showing a state where the pipe nut for spot welding and the partition plate are connected to the front side frame.

[0024] Figure 4 yes Figure 3 Enlarged view of part IV.

[0025] Figure 5 It is shown from Figure 3 A perspective view of the state where the partition is removed.

[0026] Figure 6 yes Figure 5 Enlarged view of part VI.

[0027] Figure 7 is a three-dimensional diagram of the partition.

[0028] Figure 8 This is a perspective view of the pipe nut for spot welding as viewed from obliquely above.

[0029] Fig. 9 This is a perspective view of the pipe nut for spot welding as viewed obliquely from below.

[0030] Fig.10 yes Figure 8 XX cross-section diagram.

[0031] Fig.11 yes Figure 4 XI-XI section view.

[0032] Fig.12 yes Fig.11 Section XII-XII of the diagram.

[0033] Fig.13 The second embodiment is equivalent to Figure 3 Stereoscopic diagram.

[0034] Fig.14 yes Fig.13 Section XIV-XIV of the.

[0035] Fig.15 yes Fig.14 XV-XV section view. DETAILED DESCRIPTION

[0036] Hereinafter, one embodiment of the present invention will be described based on the drawings.

[0037] [First embodiment]

[0038] Figures 1 to 12 A first embodiment of the present invention is shown in FIG. Figure 1 , Figure 2 The symbol 1 is the front part of the vehicle body. A power unit room 2 is provided in the front part of the vehicle body 1. The power unit room 2 and the rear cab 3 are separated by a footrest 4. In addition, in the following description, when it is recorded as "combination", the method of combining is to adopt the welding method using spot welding unless otherwise specified. In addition, in the figure, only the spot welding points representing the characteristic parts are marked with spot welding symbols, and the marking of spot welding symbols is omitted at other spot welding points.

[0039] The left and right sides of the power unit chamber 2 are divided by a front wheel fender 5. A front side frame (hereinafter referred to as "side frame") 6 as a pair of left and right vehicle body frames is arranged inside the front wheel fender 5. The side frame 6 extends to the front and rear of the vehicle body. The side frame 6 extending to the rear is connected to the footrest 4 in the middle.

[0040] In addition, a strut tower 7 is formed at the rear of the front wheel fender 5. A strut type suspension (hereinafter referred to as "suspension") 7 is accommodated in the strut tower 7. A strut support portion 7a is formed at the upper portion of the strut tower 7. The upper portion of the suspension 8 is supported on the strut support portion 7a via a strut upper mounting member 8a.

[0041] In addition, a suspension cross member 9 as a subframe is provided at the lower part of the power unit chamber 2. The suspension cross member 9 is arranged at a position substantially aligned with the suspension 8 in the vehicle width direction. The peripheral edge of the suspension cross member 9 is formed to be bent downward. Both sides of the suspension cross member 9 in the vehicle width direction are inclined upward. Flat mounting portions 9a are formed at both ends of the suspension cross member 9 in the vehicle width direction. A reinforcement member 10 is coupled to the back of the mounting portion 9a. In addition, although not shown in the figure, a power unit such as an engine and a motor is supported on the suspension cross member 9 via a power unit mounting portion and the like.

[0042] Arm support portions 9c are protrudingly provided on the lower surface of both ends in the vehicle width direction of the suspension cross member 9. The base of a suspension lower arm (hereinafter referred to as "lower arm") 11 is supported on the arm support portion 9c so as to be swingable in the up-down direction. The lower portion of the suspension 8 is supported on the front end side of the lower arm 11, and a wheel hub (not shown) to which the front wheel FH is fixed is rotatably supported on the front end side of the lower arm 11.

[0043] like Figure 1 to Figure 6 As shown, the left and right side frames 6 include an inner frame 12 and an outer frame 13 .

[0044] The inner frame 12 is arranged on the inner side in the vehicle width direction, and the outer frame 13 is arranged on the outer side in the vehicle width direction. Figure 1 In the figure, for convenience, a portion of the outer frame 13 of the left side frame 6 is omitted.

[0045] The inner frame 12 is formed into a hat-shaped cross section. The outer frame 13 is formed into a hat-shaped cross section with a shallower depth than the inner frame 12. The openings of the two frames 12 and 13 face each other, and flanges 12a and 13a formed on the upper and lower sides are connected to form a closed cross section.

[0046] The rear part of the left and right side frames 6 has a step portion whose height direction gradually decreases toward the rear, and the step portion is connected to the footrest 4. In addition, the lower part of the front wheel fender 5 is connected to the outer side surface of the outer frame 13 in the vehicle width direction.

[0047] The mounting portions 9 a formed on both sides of the suspension cross member 9 in the vehicle width direction come into contact with the lower side surfaces 12 b of the inner frames 12 that are components of the side frames 6 .

[0048] like Figure 1As shown in FIG. 1 , a bolt insertion hole 9b is formed in the mounting portion 9a of the suspension cross member 9. The bolt insertion holes 9b are formed at two locations at predetermined intervals in the front-rear direction of the vehicle body. Fig.11 , Fig.12 As shown, a pipe nut insertion hole 12c is bored in the lower side surface 12b of the inner frame 12 corresponding to the bolt insertion hole 9b.

[0049] The pipe portion 14a of the spot welding pipe nut 14 is inserted through the pipe nut insertion hole 12c from the outside (the bottom in the figure), and the pipe portion 14a protrudes into the inner frame 12. Figure 8 , Fig. 9 As shown, the pipe nut 14 for spot welding has a coupling flange 14b formed at the base of the pipe portion 14a. In addition, the pipe nut 14 for spot welding has a boss 14c protrudingly provided on the bottom surface of the coupling flange 14b.

[0050] The connecting flange portion 14b is formed into a rectangular shape with a predetermined plate thickness. The length direction of the connecting flange portion 14b extends along the outer surface of the lower side surface 12b of the inner frame 12 in the front-rear direction of the vehicle body. The boss portion 14c is formed into a circular ring shape. The axis of the pipe portion 14a and the center of the boss portion 14c are arranged at the center of the connecting flange portion 14b. A seat surface 14d is provided on the end surface of the boss portion 14c. The mounting portion 9a of the suspension cross member 9 abuts against the seat surface 14d.

[0051] like Fig.10 As shown in FIG. 1 , a bolt insertion hole 14e is formed in the pipe portion 14a, the connecting flange portion 14b, and the boss portion 14c of the spot welding pipe nut 14. An internal thread portion 14f is screwed in the middle of the bolt insertion hole 14e. Figure 5 , Figure 6 As shown, a coupling flange portion 14b of a spot welding pipe nut 14 and a flange portion 15b of a partition plate 15 described later are coupled to each other in a three-layer overlapping manner with the lower side surface 12b of the inner frame 12 interposed therebetween.

[0052] The pipe portion 14a of the spot welding pipe nut 14 is surrounded by a partition plate 15. Figure 7 As shown, the partition 15 is a sheet metal member bent into a groove shape when viewed from above. The opening side of the partition 15 faces the inner surface 12d of the inner frame 12 in the vehicle width direction (hereinafter referred to as the "frame inner surface"). Fig.12 As shown, the inner width between the side surfaces 15 a provided on the bulkhead 15 in the front-rear direction of the vehicle body is formed to be the same as or slightly wider than the diameter of the pipe portion 14 a.

[0053] In addition, the flange portion 15b is formed to be bent outward at the upper edge, rear edge, and lower edge of the side surface 15a. The flange portion 15b is connected to the upper side surface 12e, the frame inner surface 12d, and the lower side surface 12b of the inner frame 12. The connecting flange portion 14b of the spot welding pipe nut 14 is opposite to the lower surface of the flange portion 15b in the vehicle width direction across the lower side surface 12b of the inner frame 12. The four corners of the connecting flange portion 14b are connected to the lower side surface 12b of the inner frame 12 and the partition plate 15 in a state of overlapping three layers.

[0054] like Fig.12 As shown in FIG. 1 , the flange portion 15b of the partition 15 is formed to have substantially the same width as the coupling flange portion 14b formed on the spot welding pipe nut 14. In addition, the outer surface of the partition 15 in the vehicle width direction is in contact with or close to the inner surface of the outer frame 13. The pipe portion 14a provided on the spot welding pipe nut 14 is supported in the front-rear direction of the vehicle body by being clamped and coupled by the inner surface of the partition 15. Therefore, even when the pipe portion 14a receives vibration in the front-rear direction of the vehicle body from the suspension cross member 9, it can be suppressed from falling in this direction.

[0055] like Fig.11 , Fig.12 As shown, the mounting portion 9a of the suspension cross member 9 abuts against the seat surface 14d formed on the boss portion 14c of the spot welding pipe nut 14. The reinforcement 10 connected to the back of the mounting portion 9a is provided with a bolt insertion hole 10a, which is connected to the bolt insertion hole 9b formed on the mounting portion 9a. In addition, the support bracket 18 abuts against the back of the reinforcement 10 via the collar 17. The support bracket 18 is provided with a bolt insertion hole 18a, which is connected to the bolt insertion hole 17a formed on the collar 17.

[0056] The suspension cross member 9, the reinforcement member 10, the collar 17, and the support bracket 18 are integrated in advance. The bolt insertion holes 9b, 10a, 17a, and 18a formed in the components 9, 10, 17, and 18 are arranged coaxially. In addition, for convenience, the bolt insertion holes 9b, 10a, 17a, and 18a of the components 9, 10, 17, and 18 are collectively referred to as through holes A. In addition, the support bracket 18 supports both ends of a stabilizer extending to the left and right in the vehicle width direction.

[0057] In addition, the mounting portion 9a formed on the suspension cross beam 9 abuts against the seat surface 14d of the spot welding pipe nut 14. A bolt (hereinafter referred to as a "suspension cross beam bolt") 19 for fastening the suspension cross beam 9 is inserted from below into the through hole A formed in the mounting portion 9a. The threaded portion 19a of the suspension cross beam bolt 19 is screwed into the internal threaded portion 14f screwed on the spot welding pipe nut 14. By fastening the suspension cross beam bolt 19, the suspension cross beam 9 is fixed to the side frame 6.

[0058] In such a structure, the connecting flange 14b formed at the base of the spot welding pipe nut 14 abuts against the lower side surface 12b of the inner frame 12, and the four corners thereof are connected to the lower side surface 12b by spot welding, so that not only the productivity is good, but also the stability of the welding quality of each product can be maintained. In addition, since the connecting flange 14b is formed in a rectangular shape that is long in the front-to-back direction along the lower side surface 12b of the inner frame 12, the connecting flange 14b can be fixed to the lower side surface 12b of the inner frame 12 over a large area.

[0059] As a result, even if vibration from the suspension cross member 9 to the front-rear direction of the vehicle body is transmitted to the spot welding pipe nut 14 during driving, the stress caused by the vibration can be dispersed to the inner frame 12 side via a large area. Since the stress caused by the vibration is dispersed to the inner frame 12 side via a large area, it is possible to avoid the problem of stress concentration on the spot welding pipe nut 14. By avoiding the concentration of stress on the spot welding pipe nut 14, the rigidity of the spot welding pipe nut 14 can be relatively improved.

[0060] Furthermore, the coupling flange 14b is coupled to the lower side surface 12b of the inner frame 12 and the flange 15b of the bulkhead 15 abutting against the upper surface thereof in a three-layered manner. Therefore, even if vibration from the suspension cross member 9 is transmitted to the spot welding pipe nut 14 during driving, the stress generated by the vibration can be dispersed more widely toward the inner frame 12 and the bulkhead 15. As a result, the rigidity of the spot welding pipe nut 14 can be further improved.

[0061] In addition, a boss portion 14c is protrudingly provided on the bottom surface of the flange portion 14b of the spot welding pipe nut 14, and a seat surface 14d is formed on the bottom surface of the boss portion 14c. The mounting portion 9a of the suspension cross member 9 abuts against the seat surface 14d. When the flange portion 14b is joined to the lower side surface 12b of the inner frame 12 by spot welding, a slightly raised indentation is formed around the portion where the electrode is pressed. The mounting portion 9a abuts against the seat surface 14d of the boss portion 14c protruding from the flange portion 14b.

[0062] Therefore, the mounting portion 9a can be in surface contact with the seat surface 14d without being affected by the indentation caused by spot welding. As a result, the mounting portion 9a of the suspension cross member 9 can be fastened and fixed to the side frame 6 with high rigidity by the suspension cross member bolts 19.

[0063] The flange 14b is joined to the inner frame 12 by spot welding. Since spot welding is less likely to cause spatter, it is not necessary to cover the seat surface 14d with a masking material. As a result, the process of attaching and detaching the masking material can be omitted, and productivity can be improved.

[0064] In addition, for example, in the production process, Fig.10As shown, when it is determined that the seat surface 14d is inclined at an angle θ with the mounting portion 9a of the suspension cross member 9 and the surface accuracy is not achieved, the inclination of the angle θ can be easily corrected by cutting or grinding the seat surface 14d of the boss portion 14c using a machining center or the like. This can reduce the product defect rate.

[0065] It is known that when the mounting portion 9a of the suspension cross member 9 is fastened to the spot welding pipe nut 14 by the suspension cross member bolt 19, the fastening force (surface pressure) acts on the mounting portion 9a within the range of the impact cone. Fig.10 As shown by the middle dotted line, the influence cone is a cone drawn from the effective diameter near the starting position of the thread of the internal thread portion 14f screwed on the spot welding pipe nut 14 toward the seat surface 14d with a half apex angle (e.g., 45°) determined by the material of the spot welding pipe nut 14.

[0066] According to the theory of the influence cone, the stress generated in the internal thread portion 14f when the bolt is tightened is generated within the range of the conical expansion of the half apex angle. Therefore, on the seat surface 14d, the tightening force of the suspension beam bolt 19 is difficult to be transmitted to the area exceeding the bottom surface diameter Db of the influence cone. For example, compared with the bottom surface diameter Df in the case where the seat surface is formed on the connecting flange portion 14b, the bottom surface diameter Db of the seat surface 14d set on the boss portion 14c is only enlarged by the part higher than the height of the connecting flange portion 14b. As a result, compared with the case where the connecting flange portion 14b is set as the seat surface, by setting the bottom surface of the boss portion 14c as the seat surface 14d, the contact area for generating the surface pressure with the mounting portion 9a becomes larger. Therefore, the tightening rigidity of the contact surface can be improved.

[0067] [Second embodiment]

[0068] Figures 13 to 15 2. The same components as those in the first embodiment are denoted by the same reference numerals, and their descriptions are simplified or omitted.

[0069] In the first embodiment, the coupling flange portion 14 b of the spot welding pipe nut 14 is coupled to the lower side surface 12 b of the inner frame 12 and the flange portion 15 b of the partition plate 15 in a three-layered manner.

[0070] In contrast, the lower portion of the partition plate 15 of this embodiment is cut off. The flange portion 15b of the partition plate 15 is not connected to the lower side surface 12b of the inner frame 12, but is only connected to the frame inner surface 12d and the upper side surface 12e. The other structures are the same as those of the first embodiment described above, so the description is omitted.

[0071] Depending on the vehicle model, the structure can be simplified by using the partition plate 15 of this embodiment. In addition, when spot welding is performed, the coupling flange portion 14b of the spot welding pipe nut 14 is coupled to the lower side surface 12b of the inner frame 12 in a double-layered manner.

[0072] The thickness of the two-layer plate that connects the flange portion 14b and the lower side surface 12b of the inner frame 12 is thinner than the three-layer plate thickness of the first embodiment. Therefore, it is not necessary to increase the pressure or welding current during welding compared with the spot welding of the three-layer plate, and manufacturing becomes easy.

[0073] In addition, the present invention is not limited to the above-mentioned embodiment. For example, the vehicle body frame is not limited to the side frame 6 , and the subframe is not limited to the suspension cross member 9 .

[0074]

Explanation of symbols

[0075] 1...Front part

[0076] 2...Power unit room

[0077] 3... Cab

[0078] 4…Footrest

[0079] 5...Front wheel guard

[0080] 6...Front side frame

[0081] 7… Pillar Tower

[0082] 7a……pillar support

[0083] 8…Suspension

[0084] 8a……Pillar upper mounting piece

[0085] 9...Suspension beam

[0086] 9a……Installation

[0087] 9b, 10a, 17a, 18a... Bolt insertion holes

[0088] 9c... Arm support

[0089] 10...Reinforcement

[0090] 11… Lower arm

[0091] 12...Inner frame

[0092] 12a, 13a... flange portion

[0093] 12b...lower side

[0094] 12c...Tube nut insertion hole

[0095] 12d...Inner surface in vehicle width direction (inner surface of frame)

[0096] 12e... Upper side

[0097] 13...External frame

[0098] 14... Pipe nuts for spot welding

[0099] 14a……Tube

[0100] 14b ... Joint flange portion

[0101] 14c……Boss part

[0102] 14d……Seating surface

[0103] 14f...Internal thread

[0104] 15... Partition

[0105] 15a... Side

[0106] 15b: flange

[0107] 17... Ring

[0108] 18...Support bracket

[0109] 19...Suspension cross member bolts

[0110] 19a...Threaded part

[0111] Db, Df... bottom diameter

[0112] FH...Front wheel

[0113] θ…angle.

Claims

1. A vehicle body fastening structure, Its features include: A vehicle body frame, which is arranged on the vehicle body; a subframe having a mounting portion mounted on the vehicle body frame; a pipe nut for welding, which is combined with the vehicle body frame; and a bolt that fastens the mounting portion of the subframe to the welding pipe nut, Wherein, the welding pipe nut has: a pipe portion which is inserted through the vehicle body frame from the outside and is threadedly provided with an internal thread portion therein; and a coupling flange portion formed at a base of the pipe portion and coupled to an outer surface of the vehicle body frame, The mounting portion of the subframe is fastened to the welding pipe nut by screwing the bolt into the internal thread portion, and in the vehicle body fastening portion structure, The joining flange portion is joined to the outer surface of the vehicle body frame by spot welding, A boss portion is protrudingly provided on a surface of the coupling flange portion on a side opposite to the pipe portion across the coupling flange portion. A seat surface is provided on the end surface of the boss portion. The mounting portion of the subframe is in contact with the seat surface and is fastened by the bolt.

2. The vehicle body fastening structure according to claim 1, characterized in that: A spacer having the pipe portion covering the welding pipe nut, A flange portion formed on the bulkhead is coupled to the subframe.

3. The vehicle body fastening structure according to claim 2, characterized in that: The connecting flange portion of the welding pipe nut is connected to the flange portion formed on the bulkhead via the vehicle body frame by spot welding.

4. The vehicle body fastening structure according to claim 1, characterized in that: The coupling flange portion is formed in a rectangular shape, and a longitudinal direction thereof extends along the vehicle body frame.

5. The vehicle body fastening structure according to any one of claims 1 to 4, characterized in that: The body frame is a front side frame arranged on the left and right sides of the front part of the body in the vehicle width direction. The subframe is a suspension cross member.

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