JPH07269526A - Member fastening method - Google Patents

Abstract

PURPOSE:To enable a product to be assmbled or decomposed with ease in a short time only by heating or cooling a fastening member to a specified temperature. CONSTITUTION:A fastening pin 1 made of a shape memory alloy is stretched out straight in a condition that it is heated up to temperature higher than room temperature or temperature when a product is operating, under which condition, the fastening pin 1 is inserted into the fastening hole 2a of an inner packaging panel 2 and the fastening hole 3a of a frame member 3. After that, the tip end of the fastening pin 1 is opened as it is returned to room temperature or temperature when the product is operating, so that the inner packaging panel 2 is thereby fastened to the frame member 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of fastening members,
In particular, the present invention relates to a method of fastening members suitable for facilitating assembly or disassembly of products and shortening working time.

[0002]

2. Description of the Related Art Conventionally, bolts and nuts have been used as a fastening method for disassembling members of a product.
No. 096 method using screws, mechanism design data book (Douglas C, Nikkan Kogyo Shimbun, 1976,
There is a method using the snap fit described in P232).

Further, as a concrete example, a method of mounting an interior panel of an outfitting component of a railway vehicle will be described with reference to FIG.
Conventionally, the interior panel 2 of a railway vehicle has been screwed to the frame member 3 or the like of the vehicle structure with bolts or screws 4. In this case, when mounting or removing the interior panel 2, there is a problem that it takes time to tighten or release the screw.

[0004]

In the prior art, when bolts and screws were used, there was a drawback that it took a lot of time to set up and release the screws. In addition, when the snap fit is used, a snap fit structure must be used, and when disassembling the snap fit, a handle or an exclusive disassembling jig is required, which has a drawback that the product structure is limited.

An object of the present invention is to use a shape memory alloy or a shape memory plastic for a fastening part to heat or cool the fastening part to deform the fastening part so that the members can be fastened or disassembled easily to assemble a product. And shorten the disassembly work time.

[0006]

In order to achieve the above object, the present invention is modified by heating or cooling a fastener made of a shape memory alloy or shape memory plastic to a certain set temperature when assembling or disassembling a product. This makes it easy to fasten or disassemble the members.

Further, according to the present invention, the fastening parts are combined with materials having different linear expansion coefficients, and the fastening parts are deformed by heating or cooling to a certain set temperature to facilitate the fastening or disassembling of the members.

[0008]

The method of fastening members having the above technical means will be described below.

In the method of assembling or disassembling a product,
When the members are fastened, a shape memory alloy or shape memory plastic is used for the fastening parts, and the fastening parts are deformed by heating or cooling to a certain set temperature. That is, at the time of assembling or disassembling the product, the fastening parts are heated or cooled to deform the member into a shape that is easy to fasten or disassemble, and conversely, the member is deformed to a shape that is easily caulked or fixed at room temperature or during operation of the product. .

Further, materials having different coefficients of linear expansion are joined or joined to the fastening parts, and the fastening parts are heated or cooled to a certain set temperature at the time of assembling or disassembling the product so that the members are deformed into a shape which is easy to fasten or disassemble. Conversely, at room temperature or at the operating temperature of the product, the member is deformed into a shape that can be easily caulked or fixed.

[0011]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 12.

First, FIG. 2 shows the inside of a railway vehicle structure shown as a specific example of the product. As shown in the figure, the interior panel 2 is fixed to the frame member 3 of the vehicle with bolts or screws 4.

FIG. 1 is a cross-sectional view of a fastening portion according to an embodiment of the present invention. FIG. 1 (a) shows an interior panel 2 with a vehicle bone member 3
Shows the state of being fastened with the fastening pin 1. That is, FIG.
As shown in (b), the fastening pin 1, which is a fastening component made of a shape memory alloy, is straight when heated to a certain set temperature (heating means is not shown), and in this state the fastening pin 1 is straight. 1 is inserted into the fastening hole 2a of the interior panel 2 and the fastening hole 3a of the bone member 3. Thereafter, as shown in FIG. 1A, the pin tip 1b of the fastening pin 1 opens as the temperature returns to room temperature or the temperature during product operation, and the interior panel 2 is fastened to the bone member 3 with the fastening pin 1.

On the contrary, when removing the interior panel 2, the fastening pin 1 is heated again to a certain set temperature to close the pin tip 1b of the fastening pin 1, and the fastening pin 1 is removed in a straight state.

FIG. 3 shows an embodiment of the present invention. In the embodiment shown in FIG. 1, a rubber packing 5 for vibration isolation is attached to a fastening hole 3 of a bone member 3.
It is attached to a. Further, in this embodiment, the head 1a of the fastening pin 1 has a flat shape and is embedded in the interior panel 2.

FIG. 4 is an embodiment of the present invention, and is a cross-sectional view of a shape memory alloy fastening pin 1 having a different shape from the embodiment shown in FIG. FIG. 4A shows an interior panel 2
1 shows a state in which is fastened to the bone member 3 of the vehicle with the fastening pin 1. That is, as shown in FIG. 4B, the shape memory alloy fastening pin 1 is straight when heated to a certain set temperature (heating means is not shown). Are inserted into the fastening holes 2a of the interior panel 2 and the fastening holes 3a of the bone member 3. Thereafter, as shown in FIG. 4A, the pin tip 1b of the fastening pin 1 is cracked and opened as the temperature returns to room temperature or the temperature during product operation, and the interior panel 2 is fastened to the bone member 3 with the fastening pin 1. It

On the contrary, when removing the interior panel 2, the fastening pin 1 is heated again to a certain set temperature to close the pin tip 1b of the fastening pin 1, and the fastening pin 1 is removed in a straight state.

FIG. 5 shows an embodiment of the present invention and shows a cross section of a fastening portion before assembling of a housing such as a home electric appliance or an office automation equipment. The fastening method is a snap fit method, and the lower housing 7 to which the shape memory plastic hook 6 is attached
Then, the upper housing 8 having the recess 8a into which the hook-shaped projection 6a is fitted is pushed down to be assembled. At this time, the hook-shaped projection 6a has a shape that is easily fitted into the recess 8a. The shape of the hook-shaped projections 6a is maintained at the shape shown in the figure at normal temperature or when the product is in operation.

FIG. 6 shows a state when the assembly is completed in the embodiment of FIG. In this state, the hook-shaped protrusion 6a
Is fitted into the recess 8a of the upper housing 8, and the shape of the hook-shaped projection 6a is kept in a shape that makes it difficult to remove the upper housing 8. Therefore, the upper housing 8 and the lower housing 7 are not disassembled. There is.

FIG. 7 shows a cross section of the fastening portion of the housing before disassembly in the embodiment of FIG. That is, the hook 6 made of shape memory plastic is heated to a certain set temperature, and the lower housing 7 and the upper housing 8 are deformed so that the lower housing 7 and the upper housing 8 are easily disassembled. The body 8 can be easily separated.

FIG. 8 shows the embodiment of FIG. 7 in which the lower housing 7 and the upper housing 8 are disassembled. At this time, when the temperature of the shape memory plastic hook 6 returns to room temperature or the temperature during operation over time, the shape of the hook-shaped projection 6a returns to the shape shown in FIG.

FIG. 9 is an example diagram showing the relationship between temperature and flexural deformation of shape memory alloy and bimetal (advanced material application encyclopedia,
Industrial Research Council Encyclopedia Publishing Center, 1990. 1.20, P16
In 3), both are reversibly deformed by heating or cooling. Particularly, in the case of a shape memory alloy, one of the characteristics is that the deformation rapidly increases at the transformation temperature of the alloy. One of the inventions utilizes this phenomenon of material.

Table 1 shows examples of alloys showing a shape memory effect (Advanced Materials Application Encyclopedia, Industrial Research Encyclopedia Publishing Center, 1990.1.20, P164).

[0024]

[Table 1]

As shown in the table, a desired transformation temperature can be selected by selecting the kind of alloy or the composition ratio. Therefore, the shape memory alloy material can be selected as the fastening part material depending on the material of the product or the use condition of the product, and it can be heated or cooled so as to bring the fastening part to a certain set temperature when fastening or disassembling the member. Become.

Table 2 shows examples of plastics having a shape memory effect (Advanced Materials Application Encyclopedia, Industrial Research Encyclopedia Publishing Center, 1990.1.20, P285).

[0027]

[Table 2]

As shown in the table, the desired transformation temperature can be selected by selecting the kind or composition ratio of the plastic. Therefore, the shape memory plastic material can be selected as the fastening component material depending on the material of the product or the method of using the product.

Further, the shape memory alloy or the shape memory plastic can be properly used as the fastening component material according to the material of the member to be fastened or the usage method of the product.

Furthermore, in the above-mentioned embodiment, an example of heating the shape memory material is shown, but depending on the combination of the environment of the product and the transformation temperature of the shape memory material, the fastening part may be at room temperature or lower than the temperature at the time of product operation. It can also be cooled to a set temperature and operated.

FIG. 10 is a sectional view of a fastening portion according to an embodiment of the present invention. FIG. 10A shows a state in which the interior panel 2 is fastened to the frame member 3 of the vehicle with the fastening pin 1. That is,
As shown in FIG. 10B, the fastening pin 1 is a bimetal in which a material 1d having a larger linear expansion coefficient than the material of the pin tip 1c of the fastening pin 1 is entirely bonded. This fastening pin 1
In the state in which is heated to room temperature or to a certain set temperature higher than the temperature at the time of product operation (heating means is not shown), the fastening pin 1
It is straight, and the fastening pin 1 is inserted into the fastening hole 2a of the interior panel 2 and the fastening hole 3a of the bone member 3 in this state. After that, as shown in FIG. 10A, the shrinkage amount of the pin tip 1d of the fastening pin 1 is larger than the shrinkage amount of the pin tip 1c of the fastening pin 1 as the temperature returns to room temperature or the temperature during product operation. The pin tip 1c is entirely bent and deformed, and the interior panel 2 is fastened to the skeleton member 3 with the fastening pin 1.

On the other hand, when the interior panel 2 is removed, the fastening pin 1 is heated again to a certain set temperature and the tip 1 of the fastening pin 1 is removed.
Remove the bending deformation of c and remove the fastening pin 1 while keeping it straight.

Here, the combination of the material 1d having a higher linear expansion coefficient than the material of the pin tip 1c of the fastening pin 1 and the method of heating the fastening pin 1 have been described. In short, the material of the pin tips 1c and 1d of the fastening pin 1 is It suffices if the linear expansion coefficient is different,
Further, the fastening pin 1 may be straight when heated to a certain set temperature higher than the room temperature or the temperature during product operation or cooled to a certain set temperature lower than the room temperature or the temperature during product operation. Therefore, when the temperature returns to room temperature or the temperature at which the product is operating, the fastening pin 1 is bent and deformed,
The interior panel 2 can be fastened to the bone member 3 of the vehicle with the fastening pin 1.

On the other hand, in the case of disassembling, the bending deformation of the pin tip 1c of the fastening pin 1 is removed again by heating or cooling to a certain set temperature, and the fastening pin 1 is straightened.
Remove.

FIG. 11 is a sectional view of a fastening portion according to an embodiment of the present invention. FIG. 11A shows a state in which the interior panel 2 is fastened to the bone member 3 of the vehicle with the fastening pin 1. That is, as shown in FIG. 11B, the fastening pin 1 has the pin tip 1e.
Material with a smaller coefficient of linear expansion and lower rigidity than other materials 1
f is joined or connected at the local portions 1g and 1h. When the fastening pin 1 is heated to room temperature or a certain set temperature higher than the temperature at which the product is in operation (the heating means is not shown), the fastening pin 1 is straight, and in this state, the fastening pin 1 is used as an interior panel. 2 and the fastening hole 3a of the bone member 3. Thereafter, as shown in FIG. 11 (a), the shrinkage amount of the pin tip 1e of the fastening pin 1 becomes larger than the shrinkage amount of the pin tip 1f as the temperature returns to room temperature or the temperature at the time of product operation. The interior panel 2 is fastened to the skeleton member 3 by the fastening pin 1 due to buckling deformation and bending.

On the contrary, when the interior panel 2 is removed, the fastening pin 1 is heated again to a certain set temperature to close the pin tip 1f of the fastening pin 1, and the fastening pin 1 is removed straight.

FIG. 12 is a sectional view of a fastening portion according to an embodiment of the present invention. FIG. 12A shows a state in which the interior panel 2 is fastened to the bone member 3 of the vehicle with the fastening pin 1. That is,
As shown in FIG. 12B, the fastening pin 1 has a pin tip 1
The material 1j having a larger linear expansion coefficient and higher rigidity than the material i is joined or bonded at the local portions 1k and 1l. When the fastening pin 1 is heated to room temperature or a certain set temperature higher than the temperature at which the product is in operation (the heating means is not shown), the fastening pin 1 is straight, and in this state, the fastening pin 1 is used as an interior panel. 2 and the fastening hole 3a of the bone member 3. Thereafter, as shown in FIG. 12 (a), the shrinkage amount of the pin tip 1j of the fastening pin 1 is larger than the shrinkage amount of the pin tip 1i as the temperature returns to room temperature or the temperature during product operation. The interior panel 2 is fastened to the skeleton member 3 by the fastening pin 1 due to buckling deformation and bending.

On the contrary, when the interior panel 2 is removed, the fastening pin 1 is heated again to a certain set temperature to close the pin tip 1i of the fastening pin 1, and the fastening pin 1 is removed in a straight state.

The method of fastening or disassembling the product by heating the fastening pin 1 has been described above with reference to FIGS. 11 and 12, but it is also possible to conversely cool it. That is, FIG.
In, a material having a linear expansion coefficient lower than that of the pin tip 1e and having a linear expansion coefficient larger than that of the pin tip 1e is selected. Further, in FIG. 12, the pin tip 1i
A material having a higher linear rigidity than the material of the pin tip 1j having a smaller linear expansion coefficient than that of the pin tip 1i is selected.

[0040]

According to the present invention, as a method of fastening members to each other, a fastener made of shape memory alloy or shape memory plastic is used, or a fastener made of a combination of materials having different linear expansion coefficients is used. The product can be assembled or disassembled easily and in a short time only by heating or cooling the fastening parts to a certain set temperature.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a fastening portion showing a situation after assembling and before assembling according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing the inside of a railway vehicle structure.

FIG. 3 is a sectional view of a fastening portion showing a state after assembly in the second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a fastening portion showing a situation after assembling and before assembling in the third embodiment of the present invention.

FIG. 5 is a sectional view of a fastening portion showing a condition before assembly in a fourth embodiment of the present invention.

6 is a cross-sectional view of a fastening portion showing a state after assembly in the embodiment of FIG.

FIG. 7 is a sectional view of the fastening portion showing a state before disassembly in the embodiment of FIG.

8 is a sectional view of the fastening portion showing the situation after disassembly in the embodiment of FIG.

FIG. 9 is an explanatory view showing the relationship between temperature and flexural deformation of shape memory alloy and bimetal.

FIG. 10 is a cross-sectional view of a fastening portion showing a condition after assembling and before assembling according to a fifth embodiment of the present invention.

FIG. 11 is a cross-sectional view of a fastening portion showing a situation after assembling and before assembling in a sixth embodiment of the present invention.

FIG. 12 is a cross-sectional view of a fastening portion showing a situation after assembling and before assembling in a seventh embodiment of the present invention.

[Explanation of symbols]

1 ... Fastening pin, 2 ... Interior panel, 3 ... Bone member, 5 ... Anti-vibration rubber packing, 6 ... Hook, 7 ... Lower case, 8 ... Upper case.

Front page continuation (72) Inventor Takeshi Takenaka 794 Higashitoyoi, Kudamatsu City, Yamaguchi Prefecture Inside the Nitate Manufacturing Co., Ltd. Kasado Plant

Claims (1)

[Claims] 1. A method for fastening a decomposable member of a product, wherein a shape memory alloy or a shape memory plastic is used as a material for a fastening part, so that the fastening part is heated or cooled when the product is assembled or disassembled. The method for fastening a member is characterized in that the member is deformed so that the member can be easily fastened and disassembled.