JPH0552206A - Parts assembled structure - Google Patents

Abstract

PURPOSE:To prevent the looseness of a bolt or a pressed-in material by restraining the deformation due to creeping at the peripheral portion of a bolt insertion hole or a press-in hole. CONSTITUTION:In such a structure that a fastened part 3 which is made of metal such as Al, Mg, Zn, etc., or such metal based alloy is fastened and fixed to a specified part 1 with a bolt, a cap-shaped reinforcing member 11 is fitted to the boss portion 2 of the fastened part 3 with a bolt insertion hole 4. In the state that the peripheral portion of the bolt insertion hole 4 is locked by the reinforcing member 11, the fastened part 3 is fastened and fixed to the specified part 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly structure of two parts assembled and fixed by bolting or press fitting.

[0002]

2. Description of the Related Art For example, as shown in FIG. 6, when another component 3 having a boss portion 2 is bolted to the component 1 using the boss portion 2, a screw hole 1a is formed in the component 1. The other parts 3 are each provided with a bolt insertion hole 4 penetrating the boss portion 2, and the screw part of the bolt 5 inserted into the bolt insertion hole 4 is screwed into the screw hole 1a of the part 1 and its head is washer. The boss portion 2 is seated via 6 to generate a predetermined tightening force. Further, for example, as shown in FIG. 7, when a shaft-shaped component 9 is press-fitted into the component 8 having the boss portion 7 by using the boss portion 7, the boss portion 7 is slightly smaller than the shaft-shaped component 9. A press-fitting hole 10 having a small diameter (for example, about 60 μm) is provided, and the component 8 is forcibly driven into the press-fitting hole 10 to generate a predetermined tightening force.

[0003]

By the way, in the above-mentioned assembly structure, another component (fastened component) 3 to be bolted to one component 1 or one component (press-fitted component).
When the other component 8 into which 9 is press-fitted is formed of a metal such as Zn, Mg, or Al or an alloy based on these, generally, these materials have low high temperature creep strength, and therefore, when used in a high temperature environment. Bolt insertion hole 4 (Fig. 6)
Alternatively, the material around the press-fitting hole 10 (Fig. 7) creeps, and the bolt insertion hole 4 or the press-fitting hole 10 is deformed in a direction to alleviate the tightening force, so that the bolt 5 or the press-fitted part 9 is loosened. There was a problem that it would end up.

The present invention has been made to solve the above-mentioned conventional problems, and its purpose is to suppress deformation due to creep by reinforcing around the bolt insertion hole or the press-fitting hole. An object of the present invention is to provide an assembly structure of parts that greatly contributes to prevention of loosening of bolts or press-fitted parts.

[0005]

In order to achieve the above object, the present invention provides a part around a bolt insertion hole of another component bolted to one component, or another component into which one component is press-fitted. It is characterized in that an annular reinforcing member is integrated with a portion around the press-fitting hole of the component.

[0006]

In the assembling structure of the parts constructed as described above, since the periphery of the bolt insertion hole or the press-fitting hole is pressed by the reinforcing member, the deformation of the portion due to creep is suppressed, and the bolt or the press-fitted hole is pressed. There is no slack in the parts.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the present invention. In the figure, the same parts as those shown in FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted. A feature of the first embodiment is that a cap-shaped reinforcing member 11 is fitted to the boss portion 2 of another component (fastened component) 3 that is bolted to the first component 1. This reinforcing member 11
Is an annular standing wall portion 1 from the inner and outer peripheral edges of the annular bottom plate portion 12.
By extending 3 and 14, an annular groove 15 is formed between the wall portions 13 and 14 at the same time, and the boss portion 2 of the component to be fastened 3 is fitted into the groove 15. The width of the annular groove 15 is substantially the same as the annular thickness of the boss portion 2, and therefore the vertical wall portion 13 on the inner peripheral side of the reinforcing member 11 is formed in the bolt insertion hole 4 of the boss portion 2.
While the inner wall of the boss 2 is in close contact with the inner wall of the boss 2, the outer wall 14 of the outer wall is in close contact with the outer peripheral surface of the boss 2, and the boss 2 is restrained from the inside and the outside.

However, the reinforcing member 11 is made of a material having a higher high temperature creep strength and a smaller thermal expansion coefficient than the fastened component 3. As an example, when the component to be fastened 3 is formed of a metal such as Zn, Mg, Al or an alloy based on these, the reinforcing member 11 is formed of a steel material. The height h of the reinforcing member 11 is set to be half (1/2) or more of the height H of the boss portion 2.

In the component assembly structure constructed as described above, since most of the boss portion 7 having the bolt insertion hole 4 is restrained by the reinforcing member 11, the area around the bolt insertion hole 4 creeps during use. Even if an attempt is made to deform by, the deformation is suppressed, and therefore, the bolt 5 is not loosened.

Here, the part 1 is made of aluminum alloy casting (JIS AC2B), the part to be fastened 3 is magnesium die cast (JIS MDC1), and the reinforcing member 11 is used.
Are formed from mild steel plates (JIS SPHC), and the height h of the reinforcing member 11 is 1/2 of the height H of the boss portion 2.
Then, using the M8 steel bolt 5, the two parts 1, 3 are fastened with a tightening force of 1250 kg as shown in FIG. The sample was left in the atmosphere for a long time, and the change over time in the tightening force (axial force) of the bolt 5 was measured. For comparison, the height h of the reinforcing member 11 is set to be ⅓ of the height H of the boss portion 2 and the comparative product fastened in the same manner as described above, and the general-purpose product as shown in FIG. The same measurement test as described above was also performed on the conventional product fastened using the washer 5. The results are shown in Figure 2. In the figure,
A is the product of this example, B is the comparative product, and C is the conventional product.

From the results shown in FIG. 2, in the conventional product C using the general-purpose washer 6, the axial force of the bolt 5 suddenly decreases with the passage of time (test time), and after 300 hours, the initial axis is reduced. The power has fallen to about 30%. On the other hand, it was confirmed that the product A of this example maintained an axial force of 80% or more of the initial value even after 300 hours had passed, and there was no fear that the bolt 5 would loosen. On the other hand, in the comparative product B in which the height of the reinforcing member 11 is set to be relatively small, the axial force is less decreased than that of the conventional product C, but the initial value is obtained after 300 hours.
It is reduced to about 60%, and it is clear that the bolt 5 may be loosened.

When the component to be fastened does not have the boss portion 2 (FIG. 1), a cap-shaped reinforcing member 11 similar to the above is prepared as shown in FIG. 14 is cast around the portion around the bolt insertion hole 4 of the member 3'to be fastened having no boss. Even in such a mode, the reinforcing member 11 suppresses the deformation around the bolt insertion hole 4 due to the creep, and the bolt 5 is not loosened.

In the first embodiment (FIG. 1) and its modification (FIG. 3), the reinforcing member 11 has a bottomed cap shape. Instead of this, the outer peripheral side standing wall portion is used. It is possible to use a cylindrical one made of only 14.
Further, in the modification, the reinforcing member 11 is partially embedded in the fastened component 3'by casting, but instead of this, the reinforcing member 11 is partially pressed into the fastened component 3'by press fitting. You may make it press-fit into.

FIG. 4 shows a second embodiment of the present invention. In the figure, the same parts as those shown in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. A feature of the second embodiment is that a cap-shaped reinforcing member 21 is fitted to the boss portion 7 of another component 8 into which one component (press-fitted component) 9 is press-fitted. This reinforcing member 21 is
The standing wall portion 23 is extended from the outer peripheral edge of the annular bottom plate portion 22, and the boss portion 7 of the component 8 is tightly fitted in the recess 24 surrounded by the standing wall portion 23. The reinforcing member 21 is made of a material having a high temperature creep strength and a coefficient of thermal expansion smaller than that of the component 8, and the height h of the standing wall portion 23 is half the height H of the boss portion 7 (1 / 2) or more. In the second embodiment, since most of the boss portion 7 of the component 8 is restrained by the reinforcing member 21, even if the material around the press-fitting hole 10 is deformed due to creep during use at high temperature, The deformation is suppressed, so that the press-fitted part 9 does not loosen.

In the second embodiment, the press-fitted part 9 is a carbon steel pipe having an outer diameter of 10 mm (JIS STKM1).
From 1), the other parts 8 are magnesium die cast (JI
From S MDC1), the reinforcing member 21 is provided with a mild steel plate (JIS S
Reinforcing member 21
Is set to be 1/2 of the height H of the boss portion 2, and the press-fitted part 9 is press-fitted into the press-fitting hole 10 of the part 8 with a press-fitting margin of 60 μm. In the atmosphere of
The withdrawal load of the press-fitted part 9 after standing for 300 hours was measured. For comparison, a comparative product in which the height h of the reinforcing member 21 is set to 1/3 of the height H of the boss portion 7, and the reinforcing member 21 is simply used without using the reinforcing member as shown in FIG. The same measurement test as described above was performed on the press-fitted conventional product. The results are shown in the table below.

[0017]

【table】

From the results shown in the above table, in the conventional product which does not use the reinforcing member, the drawing load is reduced to about 1/4 of the product of this embodiment. Further, the comparative product in which the height of the reinforcing member 21 is set to be relatively small shows a pulling load more than double that of the conventional product, but it is significantly lower than that of the product of this embodiment. By the way, the pulling load of the conventional product, which is not left in a high temperature atmosphere, is about 200 kg, which clearly shows that the product of this example has excellent creep resistance.

When the above component does not have the boss portion 7 (FIG. 4), a tubular (single annular) reinforcing member 21 'is prepared as shown in FIG. No parts 8 '
Around the press-fitting hole (10), which is to be cast or press-fitted. Even in such a mode, the reinforcing member 21 'suppresses the deformation around the press-fitting hole 10 due to the creep, and the press-fitted part 9 does not loosen.

[0020]

As described above in detail, according to the assembly structure of parts according to the present invention, since the reinforcing member suppresses the deformation of the portion around the bolt insertion hole or the press-fitting hole due to creep, The bolt or the press-fitted part will not loosen over time, and the durability and reliability will be significantly improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of an assembly structure of parts according to the present invention.

FIG. 2 is a graph showing the change over time of the axial force of the bolt in the first example, compared with the comparative example.

FIG. 3 is a cross-sectional view showing a modified example of the assembly structure of the present component in accordance with the first embodiment.

FIG. 4 is a sectional view showing a second embodiment of the assembly structure of the present component.

FIG. 5 is a cross-sectional view showing a modified example of the assembly structure of the present component according to the second embodiment.

FIG. 6 is a cross-sectional view showing an example of a conventional assembly structure of parts.

FIG. 7 is a cross-sectional view showing another example of a conventional assembly structure of parts.

[Explanation of symbols]

 1 One part 2 Boss part 3 Other part 3'Other part 4 Bolt insertion hole 5 Bolt 7 Boss part 8 Other part 8'Other part 9 One part 10 Press fit hole 11 Reinforcement member 21 Reinforcement member 21 'Reinforcement Element

Claims (2)

[Claims] 1. An assembling structure of a part, wherein an annular reinforcing member is integrated with a part around the bolt insertion hole of another part which is bolted to the one part. 2. An assembly structure of a member, wherein an annular reinforcing member is integrated with a portion around the press-fitting hole of another component into which one component is press-fitted.