JP3064546B2 - Bolt fastening structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt fastening structure, for example, a bolt fastening structure used for an engine mount.

[0002]

2. Description of the Related Art As a conventional bolt fastening structure, for example, a structure described in Japanese Patent Publication No. 47-4362 is known and is shown in FIG. In FIG. 4, members 1,
2 are mutually fastened by bolts 3 and nuts 4, and such a fastening structure is generally used. Here, when the nut 4 is a member having a screw hole, such a fastening structure can be used for the fastening structure of the front cover in the engine mount portion, and is shown, for example, in FIG.

In FIG. 5, 11 is a fastening bracket, 12 is a front cover, and 13 is an engine block. The fastening bracket 11 is a bracket connected to an insulator of an engine mount (not shown), that is, the fastening bracket 11 is connected to a vehicle body side member (not shown) via the insulator. The front cover 12 is fastened to the engine block 13 by bolts 14, and a lubricating oil is stored together with a timing chain 16 in a chamber 15 defined by both members. The lubricating oil is sealed by a seal ring 17.

[0004]

However, in the conventional bolt fastening structure, for the following reasons,
There have been problems that the layout of the fastening positions becomes difficult and the assembling work becomes complicated. That is, when a force indicated by an arrow F in FIG. 5 is applied to the fastening bracket 11,
Sliding easily occurs between the fastening bracket 11 and the front cover 12. When such slippage occurs, the fastening bracket 11 and the bolt 14 hit at the point a, and a bending force having a span of the distance from the point a to the engine block 13 is applied to the bolt 14. When this bending force is repeated in the forward and reverse directions, the bolt 14
Is easy to loosen. Conventionally, in order to prevent such loosening, the axial force of the bolt 14 has been increased. Specifically, the bolt size is increased from, for example, M10 to M12 or M14, or the bolt strength is increased from 7T to 12T.
However, as a result of such measures, the layout of the fastening position becomes difficult and the assembling work becomes complicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bolt fastening structure capable of preventing a bolt from being loosened while facilitating a layout of a fastening position and assembling work.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a fastening bracket having a first through hole through which a shaft portion of a bolt is penetrated, and a press-fitted fitting bracket which is disposed on the same axis as the bolt. A collar having a second through-hole through which the shaft of the bolt having passed through the first through-hole is inserted, and an insertion hole into which the other end of the collar is inserted; A to-be-fastened member having a third through-hole penetrating the shaft of the bolt that has passed through the second through-hole, and a fastening support member that is screwed to the shaft of the bolt that has passed through the first, second, and third through-holes. the provided, the difference between the diameter of the insertion hole of the outer diameter and the fastened member of said collar, the difference between the diameter of the shaft portion in the radial bolt of the first through-hole of the fastening bracket Contact
And a difference between the diameter of the second through hole of the collar and the diameter of the shaft portion of the bolt .

[0007]

According to the present invention, when a force is applied to the fastening bracket in a direction perpendicular to the axial direction of the bolt and slippage occurs between the fastening bracket and the member to be fastened, the inner peripheral surface of the fastening bracket is attached to the shaft of the bolt. Without contacting the part, the outer peripheral surface of the collar press-fitted into the fastening bracket and the inner peripheral surface of the insertion hole of the member to be fastened abut, thereby preventing the bending force from being applied to the bolt.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of a bolt fastening structure according to the present invention. First, the configuration will be described. 1 to 3, reference numeral 21 denotes a fastening bracket, and the fastening bracket 21 includes:
It has a first through hole 21a through which the shaft portion 22b of the bolt 22 passes. The head 22a of the bolt 22 abuts on the fastening bracket 21 and is locked. Reference numeral 23 denotes a collar disposed on the same axis as the bolt 22. One end of the collar 23 is press-fitted into the fastening bracket 21, and a second through-hole of the shaft 22b of the bolt 22 that has passed through the first through hole 21a. It has a through hole 23a. The other end of the collar 23 is inserted into an insertion hole 24a of a front cover (member to be fastened) 24. The front cover 24 is provided with a shaft portion 22b of a bolt 22 that has passed through the first through hole 21a and the second through hole 23a. Has a third through-hole 24b through which a hole is formed. First
The shaft portion 22b of the bolt 22 that has passed through the through hole 21a, the second through hole 23a, and the third through hole 24b is screwed to an engine block (fastening support member) 25. A timing belt 27 and its lubricating oil are stored in a chamber 26 defined by the front cover 24 and the engine block 25.

The difference between the outer diameter R _{1 of the} collar 23 and the diameter R ₂ of the insertion hole 24 a of the front cover 24 is L ₁ , and the _first diameter of the fastening bracket 21 is
When the difference between the diameter R ₄ of the shaft portion 22b of the diameter R ₃ and bolt 22 through hole 21a and L _2, L ₁ <the relationship of L ₂ holds. The diameter of the second through hole of the collar 23 and the
The difference between the diameter of the shaft portion of the belt (hereinafter referred to as L ₃₎ for also
Set so that L ₁ <L ₃ as in L ₂ above
Have been. R ₁ to R ₄ in this embodiment, is set to _{2 · R 1 = φ15.9 ± 0.3mm} 2 · R 2 = φ16.7 ± 0.3mm 2 · R 3 = φ11.5mm 2 · R 4 = φ10mm ing.

On the other hand, as shown in FIG. 2, the fastening bracket 21 is connected to a vehicle body side member (not shown) via an engine mount 41, and the engine mount 41 is a mount on the right side of the vehicle. 42 is a center member, 43 is a front engine mount, 44 is a rear engine mount,
Illustration of the left engine mount is omitted. The front cover 24 is fastened to the engine block 25 at a number of bolting positions 51 to 63 as shown in FIG.

Next, the operation will be described. At the time of sudden start of the vehicle, when a force F indicated by an arrow in FIGS. 1 and 2 is applied to the fastening bracket 21, slip occurs on the contact surface between the fastening bracket 21 and the front cover 24. At this time, the dimensions L ₁ and L ₂ are L ₁
<Satisfies the relationship of L _2, also color 23 signed bracket 2
Because it is pressed into 1, the dimension L _1, L ₃ is of L ₁ <L ₃
Satisfies the relationship, Oyo first through hole 21a of the fastening bracket 21
The inner peripheral surface of the second through hole 23a of
The outer peripheral surface of the collar 23 abuts on the inner peripheral surface of the insertion hole 24a of the front cover 24 without abutting on the inner surface b. As a result, the force F is transmitted to the front cover 24 without being transmitted to the bolt 22, and the sliding of the fastening bracket is stopped by the contact between the collar 23 and the front cover 24. Therefore, it is possible to prevent the bending force from being applied to the bolt 22 due to the sliding of the fastening bracket 21. Since the front cover 24 is fastened to the engine block 25 at a number of bolting positions 51 to 63, no slippage occurs between the front cover 24 and the engine block 25.

As described above, in this embodiment, when the force F in the direction perpendicular to the axial direction of the bolt 22 acts on the fastening bracket 21 and slippage occurs between the fastening bracket 21 and the front cover 24, the fastening is performed. Bracket 21 is shaft part 22b of bolt 22
Without contact, the sliding stops due to the contact between the collar 23 and the front cover 24, so that the bending force caused by the sliding can be prevented from acting on the bolt 22. Therefore, even if the above-mentioned slippage occurs repeatedly in the forward and reverse directions, it is possible to prevent the bolt 22 from being loosened without increasing the axial force of the bolt 22. As a result, it is not necessary to increase the bolt size, increase the bolt strength, or extend the screwing allowance of the bolt to increase the axial force of the bolt, thereby facilitating the layout of the fastening positions and the assembling work. be able to.

[0013]

According to the present invention, the difference and color difference between the diameter of the insertion hole of the outer diameter and the fastened member of the collar, the diameter of the shaft portion in the radial bolt of the first through-hole of the fastening bracket Second kan
Since the difference between the diameter of the through hole and the diameter of the shaft of the bolt is smaller, when slippage occurs between the fastening bracket and the member to be fastened,
It is possible to prevent a bending force from being applied to the bolt, and it is not necessary to increase the axial force of the bolt. Therefore, it is possible to prevent the bolt from being loosened while facilitating the layout of the fastening positions and the assembling work.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a bolt fastening structure according to the present invention.

FIG. 2 is a schematic diagram showing an engine mount to which the bolt fastening structure in FIG. 1 is applied.

FIG. 3 is a plan view of the front cover of FIG. 1;

FIG. 4 is a sectional view of a conventional bolt fastening structure.

FIG. 5 is a sectional view of another conventional bolt fastening structure.

[Explanation of symbols]

 21 Fastening bracket 21a First through hole 22 Bolt 22b Bolt shaft 23 Collar 23a Second through hole 24 Front cover (member to be fastened) 24a Insertion hole 24b Third through hole 25 Engine block (fastening support member)

Claims (1)

(57) [Claims] 1. A fastening bracket having a first through hole through which a shaft portion of a bolt penetrates, and one end portion disposed on the same axis as the bolt and press-fitted into the fastening bracket, and penetrating through the first through hole. A collar having a second through-hole through which the shaft of the bolt is inserted, and an insertion hole into which the other end of the collar is inserted,
A member to be fastened having a third through-hole penetrating the shaft of the bolt penetrating the first and second through-holes, and a fastening screwed to the shaft of the bolt penetrating the first, second and third through-holes comprising a support member, the difference between the diameter of the insertion hole of the outer diameter and the fastened member of said collar,
Diameter of the shaft portion of the diameter of the shaft portion of the first diameter of the through hole and bolt fastening bracket and <br/> difference and the second diameter of the through hole and bolt collar
And a bolt fastening structure characterized by being smaller than the difference .