JP2023120520A - Bolt implantation structure, bolt implantation method, and upper mount of vehicle applied with bolt implantation structure - Google Patents

Abstract

To provide a bolt implantation structure capable of suppressing a plastic deformation part from protruding outward while securing sufficient binding strength between a bolt and a plate material.SOLUTION: A bolt implantation structure has a first insertion hole 10 and a second insertion hole 11 formed in two upper and lower metal fittings 8 and 9 lapped one over the other, for fixing a bolt to an inner peripheral surface 10a of the first insertion hole formed in the upper metal fittings. The root part of the bolt 12 between a shaft part 15 and a head part 14 is provided with a large-dimeter part 16 which is larger than the outer diameter of the shaft part, an inner diameter d of the inner peripheral surface of the first insertion hole is made larger than the outer diameter of an outer peripheral surface 16d of the large-diameter part 16, and the large-diameter part inserted into the first insertion hole and the second insertion hole is crushed from the axial direction of the shaft part to form a crushed deformation part 17, which enters the first insertion hole to be pressed against the inner peripheral surface of the first insertion hole.SELECTED DRAWING: Figure 5

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt planting structure and a bolt planting method for planting bolts in insertion holes of plate members, and a vehicle upper mount to which the bolt planting structure is applied.

As a conventional bolt installation structure, the one described in Patent Document 1 below, which is applied to an upper mount of a vehicle, is known.

In the conventional bolt installation structure described in Patent Document 1, as shown in FIG. 9, an outer metal fitting 21 of an upper support consists of an iron-based metal plate-like upper metal fitting 22 which is superimposed on each other in the vertical direction, and an aluminum alloy material. and the lower metal fitting 23 of .

The upper metal fitting 22 is formed in a hexagonal shape and has three first bolt insertion holes 22a penetrating therethrough at equally spaced positions in the circumferential direction. The lower metal fitting 23 has three arm-shaped fixing portions 23a protruding radially from the outer periphery of the cup-shaped main body, and positions corresponding to the respective first bolt insertion holes 22a at the tip portions of the fixing portions 23a. are formed with three second bolt insertion holes 23b.

The first bolt insertion hole 22a and the second bolt insertion hole 23b are set to have the same inner diameter on the inner peripheral surface thereof, and three bolts are fastened to each of the first and second insertion holes 22a and 23b. A bolt 24 is inserted respectively.

Each of the fastening bolts 24 has a large-diameter portion 27 having a male spline formed on its outer periphery at the base of the shaft portion 26 and the head portion 25. The large-diameter portion 27 is connected to each other via the male spline. While being press-fitted into the insertion holes 22a and 23b from below, the upper end portion of the large-diameter portion 27 in the axial direction is crushed by a pressing machine, and the upper metal fitting 22 is crimped and fixed by the fastening bolt 24 at the fixing portion 23a. .

JP 2010-14133 A

However, in the bolt installation structure of Patent Document 1, as shown in FIG. 9, the upper end portion of the large diameter portion 27 of the shaft portion 26 of the fastening bolt 24 is pressed downward by a press machine to be crushed. However, the crushed plastically deformed portion 27a is formed in a disk convex shape around the upper hole edge of the first bolt insertion hole 22a, and protrudes from the upper surface of the upper metal fitting 22 by this thickness. It has a shape.

For this reason, for example, when there is a different fastening member such as a suspension member on the vehicle body side placed on the upper surface of the upper metal fitting 22, a disc convex plastically deformed portion is formed on the lower surface of this fastening member. It is necessary to form a recess or the like for escaping 27a. Further, since the male spline is formed on the outer peripheral surface of the large diameter portion 27, the manufacturing work becomes complicated and the manufacturing work cost rises unavoidably.

The present invention has been devised in view of the technical problems of the conventional bolt installation structure. To provide a bolt installation structure capable of suppressing projection of a plastically deformed portion to the outside while securing a sufficient bonding force between a bolt and a plate material by pressing the bolt into an insertion hole and crimping the bolt.

The invention according to claim 1 of the present application has a first insertion hole and a second insertion hole formed in at least two upper and lower plate members that are superimposed, and the first insertion hole formed in at least the upper plate member. A bolt installation structure for fixing bolts to an inner peripheral surface,
A large-diameter portion having a larger diameter than the outer diameter of the shaft portion is provided at the joint portion between the head portion of the shaft portion of the bolt,
The inner diameter of the inner peripheral surface of the first insertion hole is formed larger than the outer diameter of the large diameter portion,
The large-diameter portion inserted into the first insertion hole and the second insertion hole is crushed in the axial direction of the shaft portion to form a plastically deformed portion, and the plastically deformed portion forms the first insertion hole. It is characterized in that it enters inside and comes into pressure contact with the inner peripheral surface of the first insertion hole.

ADVANTAGE OF THE INVENTION According to this invention, formation of the protrusion to the outside of a plastically deformed part can be suppressed, ensuring sufficient coupling force of a board|plate material and a bolt. In this way, as a result of avoiding the protrusion of the plastically deformed portion to the outside, there is no need to form a relief such as a recess in the separate upper fastening member as in the prior art, which complicates the manufacturing work and increases the cost. soaring prices can be suppressed.

1 is a vertical cross-sectional view of a main part of an upper mount of a vehicle to which a bolt installation structure according to a first embodiment of the invention is applied; FIG. FIG. 4 is an enlarged view of a main portion showing a state in which the bolt used in the embodiment is inserted into the first insertion hole and the second insertion hole; 1 shows a bolt used in the present embodiment, where (a) is a front view of the bolt, and (b) is a plane portion of the bolt viewed from the tip side of the shaft. 2A shows a step of crushing the large-diameter portion of the bolt according to the present embodiment, FIG. FIG. 3C is a cross-sectional view of the main parts showing a state immediately before the tip of the large diameter portion is crushed by the punch of the press machine; FIG. 5 is a cross-sectional view of a main part showing a state in which the plastically deformed portion is pushed into the outer peripheral surface of the first insertion hole; FIG. 8 is a cross-sectional view of a main part showing a second embodiment of the present invention and showing a state in which the plastically deformed portion is pushed into the first insertion hole and the second insertion hole; Fig. 8 shows a third embodiment of the present invention, where (a) is a front view of a bolt having a projection on its large diameter portion, and (b) is a plan view of the bolt viewed from the tip side of the shaft. FIG. 5 is a cross-sectional view of a main part showing a state in which projections of the large-diameter portion of the bolt according to the present embodiment have bitten into the inner peripheral surface of the second insertion hole; and FIG. 10 is a cross-sectional view showing a state in which a conventional bolt installation structure is applied to an upper mount of a vehicle.

An embodiment in which a bolt installation structure according to the present invention is applied to an upper mount of a vehicle will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a main part of a vehicle upper mount to which a bolt installation structure according to a first embodiment of the present invention is applied. FIG. FIG. 3 is an enlarged view of the essential part showing the state inserted into the insertion hole, FIG. 3 shows the bolt used in this embodiment, (a) is a front view of the bolt, and (b) is the bolt viewed from the tip side of the shaft. is the flat part of

The upper mount 1 connects the upper end of a shock absorber used in a vehicle suspension device to the vehicle body. In this embodiment, in FIG. 1, the upper side is the upward direction of the vehicle body, and the lower side is the downward direction of the vehicle body.

The shock absorber has a cylinder (not shown) and a piston rod 2 extending upward from the upper end of the cylinder. It is designed to be connected to

The upper mount 1 includes a metal inner member 3 fixed to the upper end of the piston rod 2, a metal outer member 4 fixed to the vehicle body, and interposed between the inner member 3 and the outer member 4. and a vibration-isolating member 5 that has been formed. A rubber elastic body is used for the vibration isolating member 5 , and this rubber elastic body is vulcanized and bonded to the inner member 3 .

A bound stopper (not shown) made of an elastic material is held by the outer member 4 via a holding metal fitting 6. When the shock absorber is excessively expanded or contracted, the bound stopper comes into contact with the cylinder and stops the shock absorber. It is designed to suppress excessive expansion and contraction movement of the.

As shown in FIG. 1, the inner member 3 is formed substantially in the shape of a disk, and has an insertion hole 3a in the center thereof, into which the upper end portion 2a of the piston rod 2 is inserted. The upper end portion 2a of the piston rod 2 inserted into the insertion hole 3a is fixed to the inner member 3 by a nut 7. As shown in FIG.

The vibration isolating member 5 is formed in a substantially cylindrical shape and is integrally fixed to the inner member 3 by vulcanization bonding so as to wrap the outer peripheral portion of the inner member 3 at a substantially intermediate position in the vertical direction.

As shown in FIG. 1, the outer member 4 is composed of an upper metal fitting 8 which is an upper plate material made of an iron-based metal material, and an iron-based metal material disposed on the lower surface of the upper metal fitting 8 in an overlapping state. and a lower metal fitting 9 which is a lower plate material.

The upper metal fitting 8 is entirely formed by press molding, and has a substantially cup-shaped main body 8a and a flange-shaped fixing portion 8b integrally provided at the lower end edge of the main body 8a. The vibration isolating member 5 is vulcanized and bonded to the inside of the main body 8a, and the inner member 3 is integrally fixed. The fixed portion 8b is formed in a disc shape and has three first insertion holes 10 vertically penetrating therethrough at equally spaced positions in the circumferential direction.

As shown in FIG. 2, each first insertion hole 10 is formed in a substantially perfect circular shape, and the inner peripheral surface 10a has an inner diameter d larger than an outer diameter d2 of a large diameter portion 16 of a bolt 12, which will be described later. With the bolt 12 inserted, an annular first gap C1 is formed between the inner peripheral surface 10a and the outer peripheral surface 16b of the large diameter portion 16. As shown in FIG.

As shown in FIGS. 1 and 2, the lower metal fitting 9 is formed in a flat plate shape, and its wall thickness (width length) is set to be substantially the same as that of the upper metal fitting 8. A rod insertion hole 13 through which the upper end portion 2a of the piston rod 2 can be inserted is vertically formed through the central position. A hole edge portion 13 a of the rod insertion hole 13 is formed by bending the hole edge portion of the through hole formed in the upper end wall of the metal retainer 6 from the outside in a folded shape to fix the metal retainer 6 .

Further, the lower metal fitting 9 has three second insertion holes 11 vertically penetrating therethrough at positions corresponding to the three first insertion holes 10 . Each of the second insertion holes 11 is formed in a substantially perfect circular shape, and as shown in FIG. It is

A second annular gap C2 is formed between the inner peripheral surface 11a of the second insertion hole 11 and the outer peripheral surface 16b of the large diameter portion 16 when the bolt 12 is inserted.

3(a) and 3(b), the bolt 12 has a head portion 14 and a shaft portion extending upward in the drawing from an upper surface 14a of the head portion 14, as shown in FIGS. 15 and a large-diameter portion 16 integrally provided at the base of the shaft portion 15 with the head portion 14 .

The head portion 14 is formed in a substantially disk shape, and has an annular cut portion 14b formed on the outer peripheral edge thereof, and the upper surface 14a is seated around the lower hole edge of the second insertion hole 11. As shown in FIG. ing. The shaft portion 15 has a male screw portion 15a formed on its outer peripheral surface excluding the large-diameter portion 16, into which a nut 18, which will be described later, is screwed.

As shown in FIGS. 2 and 3, the large-diameter portion 16 is formed in a truncated cone shape, and the outer peripheral surface 16b is formed in a tapered shape in which the diameter gradually decreases from the head portion 14 side toward the shaft portion 15. As shown in FIG. That is, the outer peripheral surface 16b is formed to have a gradually decreasing diameter from the head portion 14 side toward the shaft portion 15, and has an outer diameter larger than the inner diameters d and d1 of the first insertion hole 10 and the second insertion hole. formed small. Therefore, as shown in FIG. 2 and FIG. 4A, which will be described later, the shaft portion 15 is inserted into the first and second insertion holes 10 and 11 in the pre-implantation stage (immediately before). When the head 14 is seated on the lower surface of the lower metal fitting 9, it is inserted into the first insertion hole 10 and the second insertion hole 11 via the first gap C1 and the second gap C2. It has become so.

In addition, the axial length L of the large-diameter portion 16 is the tip of the minimum diameter on the shaft portion 15 side when the shaft portion 15 is inserted into the first and second insertion holes 10 and 11 . A portion 16 a protrudes from the upper edge of the first insertion hole 10 . In other words, the axial length L of the large-diameter portion 16 is formed to be greater than the overall thickness and width of the superimposed upper metal fitting 8 and lower metal fitting 9, and protrudes from the first insertion hole 10. The tip portion 16a thus formed constitutes a plastically deformed portion 17 which is axially crushed and pushed into the first insertion hole 10 when the bolt 12 is implanted, which will be described later.

That is, the pressing volume of the tip portion 16a of the large-diameter portion 16 is larger than the first gap C1 formed between the inner peripheral surface 10a of the first insertion hole 10 and the outer peripheral surface of the large-diameter portion 16. The entirety of the plastic deformation portion 17 is pushed into the first gap C1 by crushing the tip portion 16a from the axial direction.

Further, as shown in FIG. 1, a suspension member 01 on the vehicle body side having high rigidity is superimposed on the upper surface of the upper metal fitting 8, and is fastened and fixed to the suspension member 01 via bolts 12 and nuts 18. It's like

FIG. 4 shows the process of crushing the large diameter portion of the bolt in this embodiment, (a) is a cross-sectional view of the main part showing the state in which the shaft portion of the bolt is inserted into the first and second insertion holes, (b) the bolt FIG. 4C is a cross-sectional view of the main parts showing a state immediately before the tip of the large-diameter portion of the shaft is crushed by the punch of the pressing machine; . FIG. 5 is a cross-sectional view of essential parts showing a state in which the plastically deformed portion is pushed into the outer peripheral surface of the first insertion hole.
[Bolt installation method according to the present embodiment]
4(a) to 4(c), the process of implanting the bolt 12 into the upper metal fitting 8 and the lower metal fitting 9 through the first insertion hole 10 will be described below.

First, as shown in FIGS. 2 and 4A, the upper metal fitting 8 is superimposed on the upper surface of the lower metal fitting 9 while aligning the first insertion hole 10 with the second insertion hole 11 . Thereafter, the shaft portion 15 of the bolt 12 is inserted into the respective insertion holes 10 and 11 from below, and the upper surface 14a of the head portion 14 is seated around the lower hole edge of the second insertion hole 11, and the bolt 12 is assembled.

Subsequently, as shown in FIG. 4B, the lower surface of the head 14 of the bolt 12 is placed and supported on the upper surface of the base 02. It is pushed down from above in the axial direction while being set on the portion 15 . That is, the punch 19 inserts the shaft portion 15 into the central cylindrical space portion 19a formed in the axial direction, and the large-diameter portion 16 is moved by the annular protrusion 19b formed at the lower end opening edge of the cylindrical space portion 19a. is crushed downward by applying a load of, for example, about 100 kg.

Then, as shown in FIGS. 4(c) and 5, the distal end portion 16a of the large diameter portion 16 is crushed and plastically deformed, and the plastically deformed portion 17 is formed between the inner peripheral surface 10a of the first insertion hole 10 and the large diameter portion. It enters into the first gap C1 between the outer peripheral surface of the portion 16 and strongly presses against the inner peripheral surface 10a of the first insertion hole 10 . As a result, the shaft portion 15 of the bolt 12 is firmly fastened and fixed to the inner peripheral surface 10 a of the first insertion hole 10 .

In addition, the plastically deformed portion 17 is arranged and held within the inner peripheral surface 10a of the first insertion hole 10 without protruding from the upper hole edge of the first insertion hole 10, that is, the upper surface of the upper metal fitting 8. Unlike the prior art disclosed in the publication, it is not necessary to form a relief recess or the like in a separate member covering the upper plate member. As a result, the complication of the bolt 12 installation work and the increase in cost can be sufficiently suppressed.

When the tip 16a of the large-diameter portion 16 is crushed by the punch 19, the annular protrusion 19b of the punch 19 also presses the upper hole edge of the first insertion hole 10. An annular recess 10b is formed. Since this annular concave portion 10b is formed by being pushed in by a punch 19, the meat portion on the inner peripheral surface 10a side of the first insertion hole 10 moves in the direction of the plastically deformed portion 17. The bonding strength with the diameter portion 16 is further increased.

Note that the tip portion 16a of the large diameter portion 16 is crushed by the pressing force of the punch 19 to the same height as the top surface of the annular recess 10b.

Further, in this embodiment, since the inner diameter d1 of the second insertion hole 11 is formed larger than the inner diameter d of the first insertion hole 10, it is not necessary to increase the accuracy of the dimensional tolerance of the hole position. , the rise in the drilling cost of the second insertion holes 10 and 11 can be suppressed. Furthermore, since the inner diameter d1 of the second insertion hole 11 is formed to be larger than the inner diameter d of the first insertion hole 10, the diameters of the insertion holes 10 and 11 expand downward. When inserting the shaft portion 15 and the large diameter portion 16 from below into the second insertion hole 11, it becomes easy to insert, and the insertion workability is improved.
[Second embodiment]
FIG. 6 shows a second embodiment of the present invention. In this second embodiment, the load applied by the punch 19 causes the plastically deformed portion 17 to deform in addition to the first clearance C1 on the first insertion hole 10 side. 2, it is pushed into the second gap C2 on the insertion hole 11 side.

That is, the pressing volume of the tip portion 16a of the large-diameter portion 16 is larger than the total volume of the first gap C1 and the second gap C2, and the tip portion 16a is crushed by the punch 19 from the axial direction. As a result, the entire plastic deformation portion 17 is pushed into the first gap C1 and the second gap C2.

As a result, the plastically deformed portion 17 enters not only the first gap C1 but also the second gap C2 of the second insertion hole 11 and comes into pressure contact with the respective inner peripheral surfaces 10a and 11a. Therefore, the frictional resistance between the bolt 12 and the inner peripheral surfaces 10a, 11a of the insertion holes 10, 11 increases, and the coupling force between the bolt 12 and the upper and lower metal fittings 8, 9 further increases. .

Since the coupling force between the bolt 12 and the fittings 8 and 9 is increased in this manner, unnecessary rotation of the bolt 12 due to the accompanying rotation of the bolt 12 due to the tightening torque of the nut 18 screwed onto the shaft portion 15 of the bolt 12 can be sufficiently prevented. can be regulated.
[Third Embodiment]
7 and 8 show a third embodiment of the present invention. The basic configuration is the same as that of the first embodiment, but the plastically deformed portion 17 is formed at the joint between the large diameter portion 16 of the bolt 12 and the head portion 14. is formed integrally with a protrusion 20 for stopping rotation, which bites into the inner peripheral surface 11a of the second insertion hole 11 of the lower metal fitting 9 when the .

Three projections 20 are provided at equal intervals of about 120° in the circumferential direction of the large-diameter portion 16, and are formed in an approximately isosceles triangle shape when viewed from the front. 12, the head 14 is connected to the upper surface while the leading edge 20b extends perpendicularly in the direction of the shank 15. FIG. The lower edge 20a of the projecting portion 20 is set at the height of the outer peripheral surface of the head portion 14 of the bolt 12, and is gradually lowered from there to the tip edge 20b. The amount of protrusion from the leading edge 20b to the lower edge 20a is formed to be larger than the radial width of the second gap C2 of the second insertion hole 11. As shown in FIG.

Therefore, as described above, the front end portion 16a of the large diameter portion 16 is crushed by the punch 19, and the plastically deformed portion 17 enters the first gap C1 and is strongly pressed against the inner peripheral surface 10a of the first insertion hole 10. As a result, the plastically deformed portion 17 of the bolt 12 and the shaft portion 15 are firmly fastened and fixed to the inner peripheral surface 10a of the first insertion hole 10. By the downward pressing force acting on the lower metal fitting 9 via the inner peripheral surface 11a of the second insertion hole 11, the three protrusions 20 are crushed and bit into the inner peripheral surface 11a.

In other words, the inner peripheral surface 11a of the second insertion hole 11 presses the outer surface of each protrusion 20 from the tip end edge 20b to the lower end edge 20a thereof radially inward and bites them. Therefore, each protrusion 20 is pressed against the inner peripheral surface 11a of the second insertion hole 11, and the coupling force of the bolt 12 to the lower metal fitting 9 is increased. This makes it possible to restrict the occurrence of unnecessary co-rotation when the nut 18 is tightened to the shaft portion 15 of the bolt 12 with a predetermined tightening torque. Therefore, the work of tightening the nut 18 to each bolt 12 is facilitated, and a sufficient tightening force can be increased.

Further, the protrusion 20 is formed so that its height gradually increases from the lower end edge 20a to the tip end edge 20b, and is formed in a triangular shape. 2) It becomes easy to bite into the inner peripheral surface 11a of the insertion hole 11, and the biting workability is improved.

Further, in the present embodiment, three protrusions 20 are provided on the outer peripheral surface of the large diameter portion 16, and are in contact with the inner peripheral surface 11a of the second insertion hole 11 at three points. You get connectivity.

The present invention is not limited to the configuration of the above embodiment. For example, it is possible to form the inner diameters of the first insertion hole 10 and the second insertion hole 11 to have the same size. It is also possible to form the large-diameter portion 16 in the shape of a column having a uniform outer diameter instead of the shape of a truncated cone. Also, two or more upper and lower metal plates may be superimposed.

Also, in the third embodiment, three protrusions 20 are provided on the outer peripheral surface of the large-diameter portion 16, but it is also possible to provide two or four or more protrusions.

Furthermore, it is also possible to apply the bolt planting structure to devices and devices other than the vehicle upper mount as in the present embodiment.

1...Upper mount 8...Upper bracket (upper plate)
8a...Main body 9...Lower metal fitting (lower plate material)
DESCRIPTION OF SYMBOLS 10... 1st insertion hole 10a... Inner peripheral surface 10b... Annular recessed part 11... 2nd insertion hole 11a... Inner peripheral surface 12... Bolt 14... Head 14a... Upper surface 15... Shaft part 16... Large diameter part 16a... Tip part 17 Plastic deformation portion 20 Protruding portion 20a Bottom edge 20b Tip edge C1 First gap C2 Second gap

Claims (7)

A bolt having a first insertion hole and a second insertion hole formed in at least two superimposed plate members, the bolt being fixed to the inner peripheral surface of the first insertion hole formed in at least the upper plate member. An implant structure,
A large-diameter portion having a larger diameter than the outer diameter of the shaft portion is provided at the joint portion between the head portion of the shaft portion of the bolt,
The inner diameter of the inner peripheral surface of the first insertion hole is formed larger than the outer diameter of the large diameter portion,
The large-diameter portion inserted into the first insertion hole and the second insertion hole is crushed in the axial direction of the shaft portion to form a plastically deformed portion, and the plastically deformed portion forms the first insertion hole. A bolt installation structure characterized in that it enters inside and presses against the inner peripheral surface of the first insertion hole. The bolt installation structure according to claim 1,
The inner diameter of the inner peripheral surface of the second insertion hole formed in the lower plate member is formed to be larger than the inner diameter of the inner peripheral surface of the first insertion hole, and the plastically deformed portion is formed in the second insertion hole. and presses against the inner peripheral surface of the second insertion hole. The bolt installation structure according to claim 1 or 2,
A rotation-stopping protrusion that bites into the inner peripheral surface of the second insertion hole of the lower plate member when the plastically deformed portion is formed on the outer peripheral surface of the base of the large-diameter portion of the bolt with the head. A bolt planting structure characterized by providing a The bolt installation structure according to any one of claims 1 to 3,
An annular concave portion is formed on an upper side of the hole edge of the first insertion hole when the plastically deformed portion is formed by crushing the large diameter portion of the shaft portion from the axial direction of the shaft portion with a press machine. bolt installation structure. A bolt installation method comprising: a first insertion hole and a second insertion hole formed in at least two superimposed plate members; hand,
With the positions of the first insertion hole and the second insertion hole aligned, the shaft portion of the bolt is inserted into each of the insertion holes from below, and the head portion of the bolt is placed and fixed on the base. process and
A plastically deformed portion formed by crushing a large-diameter portion formed in advance at the base of the bolt shaft from above with a punch of a press inserted from above in the axial direction of the shaft. a second step of pushing into the first insertion hole as it is;
A bolt installation method comprising: The bolt installation method according to claim 5,
A method of installing a bolt, wherein the second step includes a step of continuously pushing the plastically deformed portion into both the first insertion hole and the second insertion hole. A bolt installation structure is applied which has a first insertion hole and a second insertion hole formed in at least two superimposed plate materials, and a bolt is installed in the hole edge of the first insertion hole on at least the upper side. A vehicle upper mount comprising:
A large-diameter portion having a larger diameter than the outer diameter of the shaft portion is provided at the joint portion between the head portion of the shaft portion of the bolt,
The inner diameter of the inner peripheral surface of the first insertion hole is formed larger than the outer diameter of the large diameter portion,
The large-diameter portion inserted into the first insertion hole and the second insertion hole is crushed in the axial direction of the shaft portion to form a plastically deformed portion, and the plastically deformed portion forms the first insertion hole. An upper mount for a vehicle to which a bolt installation structure is applied, which is characterized by entering inside and press-contacting with an inner peripheral surface of a first insertion hole.

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