JPH11153120A - Screw fixing structure and screw fixing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a screw fixing structure and a screw fixing method, which can enhance the workability of attachment, and which can highly restrain a screw from loosening even though a spring washer is not used. SOLUTION: A thread part 10b of a male thread 10 is inserted through an attaching hole 30b formed in a lower casing 30, and is threadedly engaged with a buried column 20 provide on the upper casing 40 side. In this screw fixing structure, resilient protrusion 30a is formed on the lower casing 30 in a position facing the screw head part 10a of the screw 10. Further, the protrusions 30 are integrally molded with the lower casing 30 made of a resin, and a recess 30c is formed in rear of the protrusion 30a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw fixing structure and a screw fixing method for forming a housing by joining upper and lower cases with screws in a portable electronic device such as a pager.

[0002]

2. Description of the Related Art Conventionally, in a joint structure of a housing or the like applied to a portable electronic device such as a pager, for example,
2. Description of the Related Art There is known a joint structure in which cases are joined and fixed by screws as shown in FIG. In FIG. 6, 50 is a spring washer, 51 is a male screw, 52 is a knurled support, 53 is a lower case, and 54 is an upper case.
In the lower case 53, at the joint with the upper case 54,
A knurl provided with a mounting hole 55 through which the male screw 51 can be inserted, and a female screw portion provided in the upper case 54 at a position facing the mounting hole 55 when joined to the lower case 53 so as to be paired with the male screw 51. A support 52 is buried. Male screw 5
Reference numeral 1 denotes a joint for fixing the lower case 53 and the upper case 54 together with the knurl support 52, and includes a spring washer 50 and a mounting hole 55 for the lower case 53.
Are screwed into the knurled support 52 of the lower case 53 in a state of being sequentially inserted. The spring washer 50
This is to prevent the loosening of the screw from occurring, and the reaction force generated due to its own elastic deformation increases the pushing force of the male screw 51 against the knurled support 52 in the axial direction, that is, the resistance to the loosening of the screw. I have. As described above, in the above-described joining structure, the upper case is fixed to the lower case by the male screw 51 and the knurled support 52, and the spring washer 50 prevents the screw from being loosened against impact, vibration, heat, and the like.

[0003]

However, the screw fixing structure using the above-described joint structure prevents the screw from being loosened, but the number of members increases by using a spring washer. Therefore, the cost of the member and the cost of assembling the member are higher than when the spring washer is not used. In particular, in a portable electronic device such as a pager, the spring washer itself is very small, so that the mounting is not easy, and the workability at the time of mounting is poor.

An object of the present invention is to solve the above-described problems. For example, in a joining structure applied to joining casings, the attaching workability is good and a spring washer is not required. However, it is an object of the present invention to provide a screw fixing structure and a screw fixing method in which loosening hardly occurs.

[0005]

According to a first aspect of the present invention, there is provided a method for fixing a male screw, wherein a threaded portion of a male screw is inserted through a mounting hole formed in a member to be fixed and is provided on the side of the fixing member. And a screw fixing structure to be screwed to the knurled support, wherein an elastic convex portion is provided on the fixed member at a position facing the head of the male screw.

As described above, according to the first aspect of the present invention, the convex member having elasticity is provided on the fixed member at a position facing the head of the male screw. At the time of screwing, the convex portion is compressed between the head of the male screw and the fixed member and undergoes compression deformation, and the reaction force generated by the compression deformation of this convex portion is generated in the axial direction of the male screw with respect to the knurl support. Since the push-up force is increased, loosening of the screw hardly occurs. In addition, by providing a convex portion having elasticity at a position facing the head of the male screw of the member to be fixed, the screw can be easily attached as compared with the screw fixing structure using the spring washer, and the assembly work can be produced. Performance can be improved.

Here, the screw may be a parallel screw having a cylindrical screw portion or a tapered screw having a conical shape. The material, shape and number of the protrusions are not limited as long as they can be elastically deformed by the fastening force of the screw. The position at which the protrusion is provided may be any position as long as the position faces the head of the male screw of the fixing member.

[0008] The invention described in claim 2 is based on claim 1.
The screw fixing structure described above, wherein the convex portion is formed integrally with the fixed member by a resin.

According to the second aspect of the present invention, since the convex portion is formed of resin integrally with the member to be fixed, the number of members for screw fixing is reduced, and the cost and cost of the member are reduced. In addition, the cost of assembling the members can be reduced.

According to a third aspect of the present invention, there is provided a screw fixing method in which a screw portion of a male screw is inserted through a mounting hole formed in a member to be fixed and is screwed with a knurled support provided on the fixing member. The fixed member has a convex portion having elasticity at a position facing the head of the male screw, and when the male screw is screwed to the knurled support, the head of the male screw and The fixing member is screw-fixed to the fixing member by compressively deforming the fixing member with the fixing member interposed therebetween.

Thus, according to the third aspect of the present invention, when the male screw is screwed into the knurled support, the male screw is compressed and deformed by sandwiching the convex portion between the head of the male screw and the fixed member. By fixing the member to be fixed to the fixing member with a screw, the reaction force generated due to the compression deformation of the convex portion increases the pushing force of the male screw against the knurled column in the axial direction, so that the screw is less likely to be loosened. Become.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a screw fixing structure according to the present invention will be described below with reference to FIGS.

First, FIG. 1 shows a pager as an example to which the screw fixing structure according to the present invention is applied.
Is a front view, (b) is a side view of (a) viewed from the direction A,
(C) shows a rear view.

A pager 100 as a portable electronic device
As shown in FIGS. 1 (a), 1 (b), and 1 (c), an upper case 40 whose casing is exemplified as a fixing member,
Lower case 30 illustrated as a member to be fixed, and battery cover 7
0, each of which is formed of an elastic resin. Further, the upper case 40 and the lower case 30 are joined to each other by a screw fixing structure described below at a portion B in FIGS. 1B and 1C.

FIG. 2 is a sectional view taken along the line C--C of a joint B between the upper case and the lower case constituting the case of the pager.

In FIG. 2, 10 is a male screw, 20 is a knurled support, 30 is a lower case, and 40 is an upper case. The male screw 10 includes a screw head 10a and a screw portion 10b, and is screwed with a knurled support 20 provided in the upper case 40 in a state where the mounting hole 30b of the lower case 30 is inserted. Is fixed to the upper case 40. The knurl support 20 is made of metal and has a knurl on an adhesive surface with the upper case 40 so that it does not rotate in the tightening direction when screwed with the male screw 10. The lower case 30 is provided with a mounting hole 30b at a joint with the upper case 40.
Are formed at positions facing the screw head 10a of the male screw 10, and concave portions 30c are formed on the back surface of these convex portions 30a.

FIG. 3 is a top view showing the vicinity of the mounting hole of the lower case 30, and FIG. 4 is a sectional view taken along the line DD of FIG.

As shown in FIG. 3, four projections 30a are formed around the mounting hole 30b of the lower case 30 so as to surround four sides of the mounting hole 30b. Mounting hole 30b
Is formed so as to be larger than the maximum outer circumference of the screw portion 10b of the male screw 10, and the screw portion 10b of the male screw 10 can be inserted through this mounting hole 30b.

The protruding portions 30a are integrally formed with the lower case 30 as shown in FIG.
0 protrudes toward the screw head 10a. The projections 30a have concave portions 30c on the rear side, and elastically deform in the direction of the concave portions 30c on the rear side with respect to the pressing force (the fastening force of the screw) from the screw head 10a of the male screw 10. It is supposed to. That is, the protrusions 30a ...
Has elasticity depending on the shape and the characteristics of the material.

As described above, when the male screw 10 and the knurled support 20 are screwed together, the projections 30a are elastically deformed, and the pushing force of the male screw 10 against the knurled support 20 in the axial direction is increased as follows. ing.

FIG. 5 is a sectional view showing a screwed state of the knurled support and the male screw.

As shown in FIG. 5, when the thread and the groove of the knurled support 20 and the male screw 10 are screwed together, they are alternately fitted. Knurl support 20
When the male screw 10 and the male screw 10 are screwed together, the convex portions 30a contacting the screw head 10a are elastically deformed, and the convex portions 30a. Occurs. This reaction force increases the pushing force of the male screw 10 against the knurled support 20 in the axial direction, that is, the surface pressure on the contact surface between the knurled support 20 and the screw portion 10b of the male screw 10, so that the resistance to the loosening of the screw is reduced. It also acts to make the screw less likely to loosen against heat and vibration.

As described above, according to the screw fixing structure of this embodiment, the lower case 30 and the upper case are formed by providing the convex portions 30a at the positions where the screw heads 10a of the lower case 30 contact. When 40 and 40 are fixed, the projection 3
0a are elastically deformed toward the recess 30c... Side of the back surface, and a reaction force is generated. The reaction force increases the pushing force of the male screw 10 against the knurled support 20 in the axial direction, that is, the resistance force against the loosening of the screw. Loosening is less likely to occur. In addition, by forming the protrusions 30a integrally with the lower case 30 with resin, the number of members can be reduced, and the cost of the members and the cost of assembling the members can be reduced.

In the above-described embodiment, the case of the pager is described as an example to which the screw fixing structure is applied. However, the present invention is not limited to this. The present invention is also applicable to a housing and the like. The convex portions 30a have an arch shape and the number of moldings is four. However, the shape and the number of moldings are arbitrary, and other specific detailed structures can be appropriately changed. Of course.

[0025]

As described above, according to the screw fixing structure according to the first aspect of the present invention, the convex portion having elasticity is provided on the fixed member at a position facing the head of the male screw. Therefore, when the male screw is screwed into the knurled support, the convex portion is sandwiched between the head portion of the male screw and the member to be fixed and undergoes compressive deformation. In this case, since the pushing force of the knurled support against the knurling column in the axial direction is increased, the screws are less likely to be loosened. In addition, by providing a convex portion having elasticity at a position facing the head of the male screw of the member to be fixed, the screw can be easily attached as compared with the screw fixing structure using the spring washer, and the assembly work can be produced. Performance can be improved.

According to the screw fixing structure according to the second aspect of the present invention, since the convex portion is formed integrally with the member to be fixed by the resin, the number of members for screw fixing is reduced, and the member is fixed. And the cost of assembling the members can be reduced.

According to the third aspect of the present invention, when the male screw is screwed into the knurled support, the convex portion is sandwiched between the head of the male screw and the member to be fixed. By compressing and deforming the fixed member to the fixing member with a screw, the reaction force generated due to the compressive deformation of the convex portion increases the pushing force of the male screw against the knurled column in the axial direction. Is less likely to occur.

[Brief description of the drawings]

FIG. 1 shows a pager as an example to which the present invention is applied, wherein (a) is a front view, (b) is a side view, and (c) is a rear view.

FIG. 2 is a cross-sectional view taken along a line CC of a joint B between an upper case and a lower case constituting a housing of the pager of FIG. 1;

FIG. 3 is a top view showing the vicinity of a mounting hole of a lower case in FIG. 2;

FIG. 4 is a sectional view taken along line DD of FIG. 3;

FIG. 5 is a cross-sectional view showing a screwed state of the knurl support and the male screw of FIG. 2;

FIG. 6 is a sectional view showing a screw fixing structure using a conventional spring washer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Male screw 10a Screw head 10b Screw part 20 Knurl support 30 Lower case (fixed member) 30a Convex part 30b Mounting hole 30c Concave part 40 Upper case (fixed member) 100 Pager

Claims (3)

[Claims] 1. A screw fixing structure in which a screw portion of a male screw passes through a mounting hole formed in a fixed member and is screwed with a female screw portion provided on a fixing member side. A screw fixing structure, characterized in that an elastic convex portion is provided at a position facing the head of the male screw. 2. The screw fixing structure according to claim 1, wherein the convex portion is formed integrally with the fixed member by a resin. 3. A screw fixing method in which a screw portion of a male screw is inserted through a mounting hole formed in a member to be fixed and screwed into a female screw portion provided on a fixing member side, wherein the member to be fixed is provided. Has a convex portion having elasticity at a position facing the male screw, and at the time of screwing the male screw to the female screw portion, between the head of the male screw and the fixed member. A method for fixing a screw, comprising compressing and deforming the convex portion to fix the member to be fixed to the fixing member with a screw.