JP2001012440A - Locking structure for screw fastening body, and locking structure for fastened member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a cost only slightly compared to one without locking structure. SOLUTION: This locking structure has a screw 1, a first fastened member 2 with a through hole 9 formed to insert the screw 1 and a second fastened member 3 having an internal thread part 12 formed to fasten the screw 1 thereto, and fastened to the first fastened member 2 by the screw 1. Either a portion including the through hole 9 in the first fastened member 2 or a portion including the internal thread part 12 in the second fastened member 3 takes a deformed part 11 recessed in an opposite direction to a fastening direction and deformed in the fastening direction when fastened. At least a part of this deformation is elastically deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing loosening of a screw fastener and a structure for preventing loosening of a material to be fastened.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a screw from being loosened when two or more workpieces (parts to be fastened) are fastened by screws, conventionally, for example, as shown in FIGS. A locking structure was employed. That is, in the one shown in FIG. 8, the screw 21 for fastening the two workpieces 22 and 23 is used.
, A spring washer 24 for preventing loosening is fitted. In the embodiment shown in FIG. 9, the screw 21 is formed integrally with a frustum-shaped spring washer 25. Further, in the one shown in FIG. 10, the screw 21 after the fastening is attached to one of the workpieces 22 by the adhesive 2.
6 are adhered.

[0003]

However, in the above-described conventional locking structure, a. The number of parts increases due to the provision of the spring washer 24, b. Use of a special screw 21 having a spring washer 25 formed thereon, c. Use of the adhesive 26, d. Screw 21
There is a problem that the cost increases due to an increase in the number of working steps due to fitting of the spring washer 24 to the spring, application of the adhesive 26, and the like.

An object of the present invention is to provide a structure for preventing loosening of a screw fastening body and a structure for preventing loosening of a material to be fastened, which can solve the above problems.

[0005]

In order to achieve the above object, the feature of the locking structure of the screw fastener according to the present invention is as follows. Screws and B. A first member to be fastened having an insertion hole through which the screw is inserted; A female screw portion formed with a first member to be fastened and screwed with a screw is formed, and the screw fastening body having a second member to be fastened to the first member to be fastened by the screw, One of a portion including the insertion hole of the member to be fastened and a portion of the second member to be screwed including the female screw portion is recessed in a direction opposite to the fastening direction, and is deformed in the fastening direction at the time of fastening. The point is that at least a part of the deformation is a deformed portion that is elastically deformed. At the time of fastening, the bottom of the deformed portion may come into contact with the workpiece to which the deformed portion is not formed. In some cases, the material to be fastened on which the deformed portion is formed may be thinner than the other material to be fastened.
Further, there is a case where a fitting portion which is recessed in the fastening direction and which fits in the deformed portion is formed on the workpiece to which the deformed portion is not formed. Further, the deformed portion and the fitting portion may be formed by drawing. Further, the feature of the structure for preventing loosening of the material to be fastened according to the present invention is that a female screw portion to which a screw is screwed is formed, and a portion including the female screw portion in the material to be fastened by the screw. The point is that it is recessed in the direction opposite to the fastening direction and is deformed in the fastening direction at the time of fastening so that at least a part of the deformation is a deformed portion that is elastically deformed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention applied to audio / visual equipment (AV equipment), various electric and mechanical devices, etc. will be described below with reference to FIGS. 1 and 2. The body has a screw 1 and first and second fastened members (fastened parts) 2, 3 and the like.

In the illustrated example, the screw 1 is a flat screw,
It comprises a head 5 and a shaft 6. On the upper surface of the head 5, a minus or plus operation groove (not shown) with which a driver is engaged is formed. The portion of the outer peripheral surface of the shaft portion 6 other than the upper end portion (base end portion) is a male screw portion 7 on which a male screw is formed.

[0008] The first fastening member 2 is, for example, a mounting portion provided for various components such as electronic and electrical components, and is made of an iron plate or the like, and a screw 1 is inserted through a predetermined portion thereof from above. A hole 9 is formed to penetrate vertically.

The second fastening member 3 is superposed below the first fastening member 2 and is fastened to the first fastening member 2. For example, the second fastening member 3 is formed as a chassis or the like and has an elastic zinc steel plate. Etc., and are manufactured by press molding. Second fastening member 3
Is thinner than the first fastening member 2, and a portion of the second fastening member 3 corresponding to the insertion hole 9 of the first fastening member 2 and a circular portion around the portion are the first fastening member. 2 are simultaneously drawn at the time of press forming, and are recessed downward, that is, in the direction opposite to the fastening direction (the side opposite to the first workpiece 2, the direction in which the screw 1 is inserted (threaded, screwed)). , And a deformed portion 11 having a bottomed cylindrical shape (it may be formed into another bottomed cylindrical shape such as a square tubular shape). A hole is formed in the center of the bottom of the deformed portion 11 so as to penetrate in the vertical direction, and the inner peripheral surface of the hole is formed with a female screw and the male screw portion 7 of the screw 1 is screwed into the female screw portion. It is assumed to be 12.

According to the above example, when the first and second workpieces 2 and 3 are fastened, as shown in FIG.
The first fastening member 2 is superimposed on the second fastening member 3 having the lower side, so that the insertion hole 9 of the first fastening member 2 and the second fastening member 3
Then, the screw 1 is inserted into the insertion hole from above and screwed into the female screw portion 12. Then, the screw 1 is screwed downward to fasten the two fastened members 2 and 3. By this fastening, as shown in FIG. 2, the deformed portion 11 of the second fastened member 3, particularly, The bottom side thereof is deformed upward, that is, in the fastening direction (the first fastened member 2 side, the retreating direction of the screw 1), and the center portion thereof comes into contact with the first fastened member 2.

By the way, in the above case, the deformed portion 1
Part of the above deformation 1 is elastic deformation, and the rest is plastic deformation. Due to the above-mentioned elastic deformation, the members to be fastened 2 and 3 are urged in a direction away from each other after fastening, and a tensile force acts on the screw 1 in the axial direction. You.

Further, since the deformed portion 11 is formed on the second fastened member 3 which is thinner than the first fastened member 2, the deformed portion 11 can be easily deformed, and the deformed portion 11 is deformed at the time of fastening. Therefore, it is not necessary to apply a large operating force to the screw 1.

Further, in the above-described example, a. Increase in the number of parts due to equipment such as spring washers, b. Use of special screws with spring washers, etc. c. Use of an adhesive, d. There is no increase in the number of work steps due to fitting of a spring washer or the like to the screw 1 or application of an adhesive, etc., and as a loosening prevention structure, the deformed portion 11 is only drawn at the same time as the press forming of the entire second fastening member 3. Is fine. That is,
In the above example, the processing for the deformed portion 11 only needs to be performed on the pressing mold, so that the cost can be slightly increased as compared with the case where there is no loosening prevention structure.

Also, when this embodiment is applied to a mounting device for various parts in audiovisual equipment (AV equipment), various electric and mechanical devices, etc., it is the same as the conventional one (that is, one having no loosening prevention structure). If the first fastening member 2 having a structure is a mounting portion provided for various components, general-purpose components can be used as various components, and therefore, the cost can be slightly increased.

In the above example, the second fastening member 3 is manufactured by press molding, and the deformed portion 11 is formed by drawing. However, the second fastening member 3 is manufactured by a method other than the above-described processing. In some cases, the deformed portion 11 may be formed. In addition, the bottom portion of the deformed portion 11 abuts on the first fastening member 2 when the fastening members 2 and 3 are fastened to each other. Further, the entire deformation of the deformable portion 11 may be elastic deformation.

FIGS. 3 and 4 show a second embodiment of the present invention.
An example is shown, in which the circular portion (the portion corresponding to the deformed portion 11) of the first fastening member 2 around the insertion hole 9 is downward, that is, in the fastening direction (the second fastening member 3 side, the screw). 1 is inserted (screwed, screwed) direction)) by drawing.
The recessed portion 14 has a bottomed cylindrical shape (it may be another bottomed cylindrical shape such as a square tubular shape), and the recessed portion 14 is tightly fitted to the deforming portion 11 (that is, the recessed portion 14 is tightly fitted). , Almost without any gaps)
Mated. The recess 14 may be formed by a method other than drawing.

According to the above example, when the first and second workpieces 2 and 3 are fastened, as shown in FIG.
The first fastening member 2 having the recessed portion 14 on the lower side is superimposed on the second fastening member 3 on which the lower portion 1 is located, and the recessed portion 14 is fitted into the deformed portion 11. The insertion hole 9 of the first fastening member 2 corresponds to the female screw portion 12 of the second fastening member 3. Next, the first
Similarly to the example, the screw 1 is inserted into the insertion hole 9 from above, the screw 1 is screwed into the female screw portion 12, and the screw 1 is screwed downward to fasten the two fastening members 2 and 3. As a result of this fastening, as shown in FIG.
1. In particular, the bottom side is deformed upward, that is, in the fastening direction, and the center side is in contact with the recessed portion 14. In this example, the bottom of the deformed portion 11 may not contact the recess 14 at the time of fastening.

According to the above example, by fitting the recessed portion 14 of the first fastening member 2 into the deformed portion 11 of the second fastening member 3, the two fastening members 2 and 3 are aligned. Yes, this allows
The screw 1 can be easily inserted into the insertion hole 9 and screwed into the female screw portion 12 in a short time, and the fastening operation can be performed easily and in a short time.

FIGS. 5 and 6 show a third embodiment of the present invention.
For example, the first fastening member 2 is made thinner than the second fastening member 3, and a circular portion of the first fastening member 2 centering on the insertion hole 9 is located upward, that is, is fastened. The deformed portion 11 is formed by drawing in a direction opposite to the direction (the side opposite to the second fastening member 3, the retreating direction of the screw 1) by drawing. In this example, the recessed portion 14 may be formed in the second workpiece 3 as in the second example.

[0020]

Next, in order to confirm the effect of the loosening prevention structure of the first example of the embodiment of the present invention, the screw fastener of the first example is used as an example, and FIG. As shown in FIG. 7, the following test was performed using the screw-fastened body having no deformed portion of the first example as a conventional example. In the embodiment and the conventional example,
The screws 1 and 21 are flat screws, the diameter of the shaft portion 6 is 3 mm, the length is 8 mm, the first fastening member 2 is an iron plate having a thickness of 2 mm, and the second fastening member 3 is It was a zinc steel sheet having a thickness of 1 mm. The deformed portion 11 was formed in a cylindrical shape having a diameter of 20 mm and a depth of 1.5 mm.

In each of the screw fasteners of the embodiment and the comparative example, after the screw 1 was fastened with a fastening torque of 17 Kgf, the screws 1 and 21 were loosened with a torque driver, and a test for measuring the loosening torque was performed. The measurement was performed 10 times, and the average value was obtained. Table 1 below shows the test results.

[0022]

[Table 1]

It can be seen from Table 1 that the embodiment of the present invention has a larger loosening torque than the comparative example and has an effect of preventing loosening.

[0024]

As described in detail above, according to the present invention,
The following effects are obtained. A. Looseness after fastening of the screw can be favorably prevented. B. Also, as compared with the one without the loosening prevention structure, b. Increase in the number of parts due to equipment such as spring washers, b. Use of special screws with spring washers, etc. c. Use of an adhesive, d.
There is no increase in the number of working steps due to fitting of a spring washer or the like to a screw, application of an adhesive, or the like, and it is only necessary to form a deformed portion at the same time as manufacturing the second member to be fastened as a loosening prevention structure. Therefore, the cost can be slightly increased as compared with the case where there is no loosening prevention structure. C. Furthermore, the present invention relates to audio-visual equipment (AV
Even when the present invention is applied to a device for mounting various components in various devices such as equipment, various electric devices, and mechanical devices, the first fastening member having the same structure as that of a conventional device (that is, a device having no locking structure) is provided in each component. With such a mounting portion, general-purpose components can be used as various components, and therefore, the cost can be slightly increased.

According to the third aspect, since the deformed portion is formed on the second fastening member thinner than the first fastening member, the deformed portion can be easily deformed, and the deformed portion is deformed at the time of fastening. Therefore, it is not necessary to apply a large operating force to the screw.
According to the fourth aspect, by fitting the recessed portion into the deformed portion, at least rough positioning of both the members to be fastened can be performed. Can be easily and quickly screwed into the female screw portion of the second fastening member, and the fastening operation can be easily and quickly performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a state before fastening in a first example of an embodiment of the present invention.

FIG. 2 is a sectional view showing a state after fastening in FIG. 1;

FIG. 3 is a sectional view showing a state before fastening in a second example of the embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a state after fastening in FIG. 3;

FIG. 5 is a sectional view showing a state before fastening in a third example of the embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a state after fastening of FIG. 5;

FIG. 7 is a cross-sectional view showing a conventional example without a loosening prevention structure.

FIG. 8 is a cross-sectional view showing an example of a conventional locking structure.

FIG. 9 is a cross-sectional view showing an example of a conventional locking structure.

FIG. 10 is a cross-sectional view showing an example of a conventional locking structure.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 screw 2, 3 first and second fastening members 7 male screw portion 9 insertion hole 11 deformed portion 12 female screw portion 14 concave portion

Claims (6)

[Claims] 1. A. First Embodiment A screw; B. a first fastening member having an insertion hole through which the screw is inserted; A female threaded part, which is superposed on the first material to be fastened and into which a screw is screwed, is formed, and has a second material to be fastened to the first material to be fastened by the screw. One of a portion including the insertion hole of the member to be fastened and a portion of the second member to be screwed including the female screw portion is recessed in a direction opposite to the fastening direction, and is deformed in the fastening direction at the time of fastening. A loosening prevention structure for a screw-fastened body in which at least a part of the deformation is a deformable portion that is elastically deformed. 2. The locking structure according to claim 1, wherein a bottom portion of the deformed portion comes into contact with a workpiece on which the deformed portion is not formed. 3. The loosening prevention structure for a screw-fastened body according to claim 1, wherein the material to be fastened in which the deformed portion is formed is thinner than the other material to be fastened. 4. The fixing member according to claim 1, wherein the material to be fastened is provided with a fitting portion which is recessed in the fastening direction and fitted into the deformation portion. Structure to prevent loosening of screw fasteners. 5. The structure according to claim 4, wherein the deformed portion and the fitting portion are formed by drawing. 6. A member to be fastened by forming a female screw portion into which a screw is screwed and fastening with the screw, the portion including the female screw portion is: Sometimes, the material to be fastened is deformed in the fastening direction and at least a part of the deformation is elastically deformed.