Vehicle fastening structure

Abstract

To avoid the occurence of galvanic corrosion between dissimilar metals due to water immersion in an inner space of a conventional vehicle fastening part structure.SOLUTION: In a vehicle fastening part structure 10 of the present invention, an annular projection 31 and an annular recessed portion 32 are formed on an upper end surface 14C of a height adjustment spacer 14. Then, a bolt 12 is tightened into a weld nut 13, and thereby a part of the projection 31 is compressed and deformed into the recessed portion 32. Thus, a water stop wall 42 formed from the projection 31 is formed on the upper end surface 14C. With such a structure, water is prevented from being immersed into an insertion hole 14A of the height adjustment spacer 14 during traveling or the like of a vehicle Accordingly, the occurence of galvanic corrosion between dissimilar metals is avoided, and hydrogen embrittlement fracture of the bolt 12 is avoided.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a fastening structure for a vehicle. [Background technology]

[0002] Patent Document 1 discloses a conventional vehicle fastening structure in which a drive unit is connected to a suspension member via a connector and a pivot shaft. To increase the connection strength between the connector and the suspension member, the suspension member is provided with upper and lower plate members, bulkheads that connect the upper and lower plate members to each other, and reinforcing members that connect the upper and lower plate members and the bulkhead.

[0003] The pivot shaft includes a collar disposed between the reinforcing members and a fastener that fastens the reinforcing members and the suspension member together. A plurality of plate members that constitute the reinforcing members and the suspension member are sandwiched between the upper end of the collar and the nut and between the lower end of the collar and the head of the bolt. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-253642 Summary of the Invention [Problem to be solved by the invention]

[0005] In the fastening structure described above, water may seep in between the upper end of the collar and the plate member, or between the head of the nut or bolt and the plate member, and the infiltrated water may accumulate inside the collar. If water accumulates inside the collar, galvanic corrosion occurs between the bolt and the surrounding dissimilar metal parts, generating hydrogen. This hydrogen may then be adsorbed by the bolt, diffuse into the grain boundaries, and cause fracture due to hydrogen embrittlement fatigue.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to provide a fastening structure for a vehicle that prevents hydrogen embrittlement fracture of bolts constituting the fastening structure due to galvanic corrosion between dissimilar metals caused by water infiltration into the fastening structure. [Means for solving the problem]

[0007] In the fastening structure of a vehicle of the present invention, a height-adjusting spacer is interposed between a first body frame and a second body frame, and the first body frame and the second body frame are fixed by bolt fastening using a bolt and a nut, and the fastening structure of a vehicle has a first insertion hole into which the bolt is screwed, and is welded to the inner surface of the first body frame. do the height-adjustable spacer has the nut to be fixed to the first body frame, a second insertion hole through which the bolt is inserted and is arranged in contact with the outer surface of the first body frame, a mounting hole in the second body frame, the second insertion hole, the mounting hole in the first body frame and the bolt inserted into the first insertion hole, and the contact surface of the height-adjustable spacer with the first body frame is formed with a protrusion formed around the second insertion hole all the way around, and a recessed portion formed around the second insertion hole near the protrusion all the way around. [Effects of the Invention]

[0008] The vehicle fastening structure of the present invention has a protrusion and a recess formed around the second insertion hole on the contact surface of the height adjustable spacer with the first body frame. When the bolt is tightened into the nut, a portion of the protrusion is compressed and deformed into the recess. A water blocking wall formed from the protrusion is formed on the contact surface, and the top surface of the water blocking wall abuts against the first body frame. This structure prevents water from penetrating into the height adjustable spacer while the vehicle is traveling, etc. This also prevents galvanic corrosion between dissimilar metals and hydrogen embrittlement failure of the bolts that make up the fastening structure. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view illustrating a fastening structure for a vehicle according to an embodiment of the present invention. [Figure 2] 1 is an exploded perspective view illustrating a fastening structure for a vehicle according to an embodiment of the present invention; [Figure 3] 1 is a top view illustrating a fastening structure for a vehicle according to an embodiment of the present invention; [Figure 4] 1 is a cross-sectional view illustrating a fastening structure for a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle fastening structure 10 according to one embodiment of the present invention will be described in detail below with reference to the drawings. In the description of this embodiment, the same components will generally be designated by the same reference numerals, and repeated description will be omitted. In the following description, the up-down direction refers to the height direction of the vehicle, the left-right direction refers to the width direction of the vehicle as viewed from the front, and the front-rear direction refers to the length direction of the vehicle.

[0011] Fig. 1 is a cross-sectional view illustrating a vehicle fastening structure 10 according to this embodiment. Fig. 2 is an exploded perspective view illustrating the vehicle fastening structure 10 according to this embodiment. Fig. 3 is a top view illustrating a height-adjusting spacer 14 of the vehicle fastening structure 10 according to this embodiment. Fig. 4 is a cross-sectional view illustrating a height-adjusting spacer 14 of the vehicle fastening structure 10 according to this embodiment.

[0012] 1 and 2, a vehicle fastening structure 10 is used to fasten a suspension member 17 and a suspension frame 18 when, for example, changing the ground clearance of a vehicle according to each vehicle model using a common standard suspension. The suspension member 17 corresponds to the first body frame of the present invention, and the suspension frame 18 corresponds to the second body frame of the present invention.

[0013] Here, automobiles with different vehicle heights are manufactured according to the specifications of each vehicle model, depending on the intended use, etc. Manufacturing a unique suspension for each vehicle model would increase manufacturing costs. Therefore, by inserting the height-adjustable spacer 14 between the suspension member 17 and the suspension frame 18, a standardized suspension is realized, thereby suppressing increases in manufacturing costs.

[0014] As shown in the figure, the vehicle fastening structure 10 mainly includes a bolt 12, a weld nut 13, a height-adjusting spacer 14, a plate nut 15, and a bushing 16. The vehicle fastening structure 10 fixes the suspension member 17 and the suspension frame 18 by fastening the bolts together, with the height-adjusting spacer 14 interposed between the suspension member 17 and the suspension frame 18.

[0015] Weld nut 13 is inserted into mounting hole 17A provided in suspension member 17 and is welded to an inner surface 17D of suspension member 17. Furthermore, an insertion hole 13A for threaded engagement with bolt 12 is formed in the center of weld nut 13. The dotted-chain line indicates an axis 21 of bolt 12, and the center of insertion hole 13A of weld nut 13 is located on the axis 21 indicated by the dotted-chain line. The centers of mounting holes 17A, 17B of suspension member 17 are located on the axis 21 indicated by the dotted-chain line. Furthermore, insertion hole 13A corresponds to the first insertion hole of the present invention.

[0016] With this structure, weld nut 13 is welded and fixed to suspension member 17, and its upper side is clamped by suspension member 17 through mounting hole 17A. By being welded and fixed to suspension member 17 in advance, weld nut 13 functions as a positioning part when assembling suspension frame 18 to suspension member 17.

[0017] The height-adjustable spacer 14 is generally cylindrical, with its upper end surface 14C and lower end surface 14B formed as circular flat surfaces. The height-adjustable spacer 14 is made of aluminum or an aluminum alloy, which reduces its weight. The material for the height-adjustable spacer 14 is not limited to aluminum or an aluminum alloy; light metals such as zinc and magnesium, or light metal alloys, can also be used. Steel can also be used as the material by applying an anti-rust treatment.

[0018] An insertion hole 14A is formed in the center of the height-adjustable spacer 14, through which the bolt 12 is inserted. The inner diameter of the insertion hole 14A is approximately the same as the outer diameter of the bolt 12. The center of the insertion hole 14A of the height-adjustable spacer 14 is located on the axis 21 indicated by the dashed dotted line. The insertion hole 14A corresponds to the second insertion hole of the present invention.

[0019] An annular locking protrusion 22 is formed on the lower end surface 14B of the height-adjustable spacer 14 around the insertion hole 14A. The locking protrusion 22 is fitted into an inner cylinder 24 of the bushing 16. This structure makes it difficult for the height-adjustable spacer 14 to fall off the bushing 16 or become misaligned relative to the bushing 16 during assembly or transportation. Meanwhile, as will be described in detail later, the upper end surface 14C of the height-adjustable spacer 14 comes into contact with an outer surface 17C of the suspension member 17. An annular protrusion 31 (see FIG. 3) and a recess 32 (see FIG. 3) are formed on the upper end surface 14C around the insertion hole 14A.

[0020] The bushing 16 mainly comprises an inner cylinder 24 and an outer cylinder 25 made of steel, and a vibration-isolating rubber portion 23. The centers of the inner cylinder 24 and the outer cylinder 25 are arranged so as to be positioned on the axis 21 indicated by the dashed dotted line. The vibration-isolating rubber portion 23 is interposed between the inner cylinder 24 and the outer cylinder 25.

[0021] The bushing 16 is press-fitted and fixed at a desired location on the suspension frame 18. Then, the bolt 12 is inserted into the inner tube 24 of the bushing 16. In other words, the inner tube 24 of the bushing 16 is used as the mounting hole 11 of the suspension frame 18. As shown in the figure, the bolt 12 is inserted into the plate nut 15 from below with the bushing 16 placed on the top surface of the plate nut 15.

[0022] The bolt 12 is, for example, a high-strength steel bolt. The bolt 12 is inserted from below the plate nut 15 upward in the vehicle height direction, successively through the insertion hole 15A of the plate nut 15, the mounting hole 11 of the suspension frame 18, the insertion hole 14A of the height-adjusting spacer 14, the mounting hole 17B of the suspension member 17, and the insertion hole 13A of the weld nut 13. The bolt 12 is threaded into the weld nut 13, thereby fixing the suspension frame 18 to the suspension member 17.

[0023] As shown in Fig. 3, the upper end surface 14C of the height-adjustable spacer 14 is a flat surface that is approximately horizontal with respect to the axis 21 indicated by the dashed-dotted line. An insertion hole 14A is formed in the center of the upper end surface 14C. A protrusion 31 and a recess 32 are formed around the insertion hole 14A on the upper end surface 14C. The protrusion 31 and the recess 32 are formed in an annular shape around the entire circumference of the insertion hole 14A. For example, as shown by the dotted line 41 in Fig. 4, the recess 32 is formed between the insertion hole 14A and the protrusion 31, and the protrusion 31 is formed continuous with the recess 32.

[0024] The area indicated by the dotted circle indicates a welding area 33 where the weld nut 13 is projection-welded to the inner surface 17C of the suspension member 17. When the weld nut 13 is projection-welded to the suspension member 17, the welding area 33 of the suspension member 17 protrudes toward the height-adjusting spacer 14.

[0025] That is, the outer surface 17C (see FIG. 4) of the suspension member 17 is formed as a flat surface, but the welding process causes it to become somewhat uneven. As a result, it becomes difficult for the outer surface 17C of the suspension member 17 and the upper end surface 14C of the height-adjusting spacer 14 to be in close contact over substantially the entire surface after fastening. Furthermore, there is a risk of water entering the gap 43 (see FIG. 4) between the outer surface 17C of the suspension member 17 and the upper end surface 14C of the height-adjusting spacer 14 from the external space.

[0026] As shown in the figure, an alignment protrusion 34 is formed on the outer side of the protrusion 31 on the upper end surface 14C. As will be described in detail later, an alignment recess 35 (see FIG. 4) is formed on the suspension member 17 from its outer surface 17C side.

[0027] 4, by tightening the bolt 12 into the weld nut 13, the upper end surface 14C of the height-adjustable spacer 14 and the outer surface 17C of the suspension member 17 are brought into pressure contact with each other. As described above, the suspension member 17 is made of steel, and the height-adjustable spacer 14 is made of aluminum or an aluminum alloy.

[0028] With this structure, in the height-adjustable spacer 14, as shown by hatching 44, due to the difference in hardness between the suspension member 17 and the protrusion 31, most of the protrusion 31 is crushed by compressive deformation toward the recess 32. Meanwhile, the recess 32 is embedded in the crushed protrusion 31. At this time, not all of the protrusion 31 is compressively deformed toward the recess 32, and part of the protrusion 31 remains as an annular water blocking wall 42 on the upper end surface 14C around the recess 32. As a result, in the gap 43, the insertion hole 14A is separated from the external space by the water blocking wall 42. The outer surface 17C of the suspension member 17 abuts against the top surface of the water blocking wall 42 in an annular shape.

[0029] For example, even if the vehicle is traveling in the rain and water seeps into the gap 43, the water is blocked by the water blocking wall 42 and prevented from flowing into the insertion hole 14A. This prevents galvanic corrosion from occurring between the height-adjustable spacer 14 and the suspension member 17 or the bolt 12 in the gap 43 or insertion hole 14A inside the water blocking wall 42. As a result, the generation of hydrogen due to the galvanic corrosion is also suppressed, preventing the bolt 12 from losing strength or breaking due to hydrogen embrittlement fatigue.

[0030] Furthermore, as shown in the figure, when the protrusion 31 is compressed and deformed, the alignment protrusion 34 on the upper end surface 14C of the height-adjusting spacer 14 is housed in the alignment recess 35 of the suspension member 17. Therefore, the alignment protrusion 34 is not compressed and deformed by the suspension member 17, and maintains its shape even after the vehicle fastening structure 10 is fastened.

[0031] When a vehicle is repaired after an accident, the height-adjustable spacer 14 is also removed when the suspension frame 18 is removed from the suspension member 17. After the repair work is completed, the same height-adjustable spacer 14 can be reused when assembling the suspension frame 18 to the suspension member 17. In other words, the alignment protrusion 34 of the height-adjustable spacer 14 maintains its current shape without undergoing compressive deformation, allowing it to be aligned with the outer surface 17C of the suspension member 17. As a result, the height-adjustable spacer 14 can be reused, reducing manufacturing costs.

[0032] In this embodiment, the height-adjustable spacer 14 has been described as having the protrusion 31 formed continuously with the recess 32 and formed outside the recess 32, but this is not limited to this. For example, the protrusion 31 may be formed inside the recess 32. Also, it is sufficient that the protrusion 31 is compressed and deformed and moves into the recess 32; the protrusion 31 and the recess 32 do not need to be formed continuously, but may be located adjacent to each other.

[0033] Furthermore, although the vehicle fastening structure 10 has been described as being used in a fastening portion between a suspension member 17 and a suspension frame 18, it is not limited to this case. The vehicle fastening structure 10 can also be used in other fastening locations where the vehicle height is adjusted using a height-adjusting spacer 14, for example, and is effective in preventing water from entering the interior. Various other modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0034] 10 Vehicle fastening structure 11 Mounting hole 12 volts 13 Weld Nut 13A Insertion hole 14 Height adjustment spacer 14A Insertion hole 14C Top surface 15 Plate Nut 15A Insertion hole 16 Bush 17 Suspension member 17A, 17B mounting holes 17C External surface 17D inner surface 18 Suspension frame 21 Axis center 22 Locking protrusion 23 Anti-vibration rubber part 24 Inner cylinder 31 Protrusion 32 recess 34 Alignment protrusion 35 Alignment recess 42 Water cutoff wall 43 Gap

Claims

1. A vehicle fastening structure in which a height-adjustable spacer is interposed between a first body frame and a second body frame, and the first body frame and the second body frame are fastened together by bolt fastening using bolts and nuts, the nut having a first insertion hole into which the bolt is screwed and fixed to an inner surface of the first vehicle body frame by welding; the height adjustment spacer having a second insertion hole through which the bolt is inserted and disposed in contact with an outer surface of the first vehicle body frame; the bolt is inserted into the mounting hole of the second body frame, the second insertion hole, the mounting hole of the first body frame, and the first insertion hole, A vehicle fastening structure characterized in that a protrusion formed around the second insertion hole and a recess formed around the second insertion hole in the vicinity of the protrusion is formed on the contact surface of the height adjustment spacer with the first vehicle body frame.

2. The contact surface of the height-adjusting spacer is formed with a positioning protrusion, 2. The fastening structure for a vehicle according to claim 1, wherein the first body frame has an alignment recess formed therein into which the alignment protrusion is inserted.

3. 3. The vehicle fastening structure according to claim 1, wherein the height-adjusting spacer is made of aluminum or an aluminum alloy.

4. 4. The vehicle fastening structure according to claim 1, wherein the mounting hole of the second body frame is formed by an inner cylinder of a bushing fixed to the second body frame.

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