JPH10159824A - Part screw stopping structure of case body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a part screw stopping part on a case body without using a fixture or a tool. SOLUTION: A boss part 31 and a pair of circular-arc-shaped engaging holes 32 at the root thereof are formed to a case body 30 by integral molding. A screw stopping member 21 is made of a steel plate, and a screw hole 24 is provided in the upper part of a cylindrical wall 22 having an inside diameter to be put on the boss part 31, and the lower end part of the cylindrical wall is provided with clamping pawls 26 that is formed nearly in an L-shape within the same curved surface. When the screw stopping member 21 is put on the boss part 31 and the clamping pawls 26 are passed through the engaging holes 32 and then turned clockwise, the clamping pawls 26 engage with the case body 30, and the screw stopping member 21 is fixed to the case body 30. This screw stopping member 21 performs the same working as the conventional resin insert and the stud for a steel plate or the like, when the printed circuit board or the like is fitted to a case body by means of screws.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component screwing structure provided on a housing for fixing various components incorporated in the housing of an electric device or the like to the housing with screws.

[0002]

2. Description of the Related Art For example, as shown in FIG. 9, a screw hole 1a made of a brass rod as a material and having a knurled outer periphery for a cylindrical resin is used as a conventional structure for screwing parts of this kind of housing. Using insert 1, or Figure 1
As shown in FIG. 0, there is a type using a steel plate stud 2 provided with a screw hole 2a. The resin insert method shown in FIG. 9 is applied to a resin housing 3. As shown in FIG. 9A, a boss 4 having a fitting hole 4 a is molded integrally with the housing 3. deep. Then, as shown in FIG. 9 (b), the resin insert 1 is placed on the boss portion 4 to cause the soldering iron 5 as a heater to generate heat. Heat is applied to the insert 1, and the heat is used to soften the boss portion 4 and
When the resin insert 1 is pushed to a predetermined depth with
As shown in (c), the resin insert 1 is press-fitted and fixed to the boss portion 4 to obtain the component screwing portion structure 6. A printed circuit board or the like is fixed to the screw hole 1a of the resin insert 1 of the component screwing portion structure 6 with a screw.

[0003] The steel plate stud system shown in Fig. 10 is applied to a case 13 made of a steel plate. As shown in Fig. 10A, a crimp hole 13a is formed in the case 13. And
As shown in FIG. 9 (b), the steel plate stud 2 is placed in the caulking hole 13a, and the steel plate stud 2 is pushed in with the press-fitting tool 15, as shown in FIG. 10 (c). It is press-fitted and fixed,
Is obtained. A printed board or the like is fixed to the screw hole 2a of the steel plate stud 2 of the component screwing portion structure 16 with a screw.

[0004]

In the above-mentioned conventional component screwing structures 6, 16 both use a jig and a tool, so that they are complicated. In addition, since a jig and a tool are used, it is difficult to incorporate each of the electric components and the like into a housing and assemble them into a normal assembly line for assembling a product. The disadvantage is that another special assembly process is required to assemble.

If the resin insert 1 or the steel plate stud 2 is damaged in the special assembling process or due to defective component mounting on a normal product assembly line, the damaged resin There is also a problem that the insert 1 and the steel plate stud 2 cannot be easily replaced. That is, even if the resin insert 1 or the steel plate stud 2 can be removed from the housing, the mounting portion on the housing side is damaged, so that a new resin insert or steel plate stud cannot be mounted, and the housing is discarded. There is a problem that must be disposed of.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional drawbacks, and has been made so that a component screwing portion structure can be provided in a housing without using a jig or a tool. It is possible to incorporate the assembly process into the normal product assembly line, and if the components of the component screw structure are damaged, it is possible to replace the components without damaging the housing, It is an object of the present invention to provide a component screwing structure of a housing that does not require disposal of the housing.

[0007]

According to the present invention, there is provided a component screwing structure for a housing, which has a cover surface on an upper portion of a cylindrical wall and has a screw hole in the center of the cover surface. The lower end is provided with a metal screw fitting having a substantially L-shape within the same curved surface as the cylindrical wall and having a hook portion having a horizontal portion extending in the circumferential direction, and a cylindrical outer peripheral surface on the housing side. A projection having a projection and an arc-shaped engagement hole formed around the projection are provided, and the screw fitting is placed on the projection so that its hooking claw passes through the engagement hole, and then rotated. Thus, the screw fitting is fixed to the housing.

According to a second aspect of the present invention, the screw fitting of the first aspect is formed by pressing a single metal plate, and a screw hole is formed at the center of a generally rectangular plate by burring and tapping. Then, by cutting out the vicinity of both end portions of the strip-shaped flat plate to form an L-shaped portion which becomes a hook claw later, this metal plate material is separated into a cylindrical wall in which a substantially circular portion remains in a central portion which will later become a lid surface and is separated. The metal body and the hooking claw are formed by drawing so that both side portions thereof are each formed into an arc cross section.

A third aspect of the present invention is characterized in that the horizontal extension direction of the hooking claw of the screw fitting in the first aspect is rightward in the circumferential direction when viewed from above.

A fourth aspect of the present invention is characterized in that the housing according to the first aspect is made of a resin, and the projecting portion and the engaging hole are formed during resin molding.

A fifth aspect of the present invention is characterized in that the casing according to the first aspect is made of a metal plate, and burring and drilling are performed on a part of the casing to form the projecting portion and the engaging hole. And

A sixth aspect of the present invention is characterized in that the upper edge of the L-shaped horizontal portion of the hooking claw of the screw fitting according to the first aspect is tapered so as to taper toward the front end.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given with reference to the embodiment of FIG. FIG. 1 is a perspective view of a screw fitting 21 used for a component screwing portion structure of a housing according to an embodiment of the present invention, FIG. 2 is a bottom view, and FIG. 3 is a partially cutaway front view. The screw fitting 21 has a cover surface 23 at the upper part of the cylindrical wall 22, and has a screw hole 24 at the center of the cover surface 23. It has a configuration in which a hooking claw 26 having a shape whose horizontal portion 26a extends in the circumferential direction is provided. As will be described later, the horizontal extension direction of the hooking claw 26 is circumferentially rightward when viewed from above, in relation to the operation of fixing a component such as a printed board to the screw fitting 21 with a screw. . The screw fitting 21 of the illustrated example is manufactured by pressing a steel sheet material 21 ′ having an unfolded shape shown in FIG. 4, and a screw hole 24 is formed in the center of a generally rectangular plate by burring and tapping. L-shaped part 26 'which cuts out the vicinity of both ends of the strip-shaped flat plate and becomes a hook afterwards
This steel sheet material 21 ′ is drawn so that a circular portion remains in a central portion 23 ′ which will later become a lid surface, and both side portions 22 ′ which become a separated cylindrical wall afterwards are each formed into an arc cross section. The metal fitting main body 2 as shown in FIGS.
5 and the hook 26 are formed. Also,
In the hooking claw 26 of the embodiment, the upper edge 26a of the L-shaped horizontal portion is tapered so as to taper toward the front end side so as to firmly engage with a housing described later.

In the component screwing portion structure of the present invention, a projecting portion and an engaging hole are provided on the housing side to mount the screwing metal fitting 21 to the housing. 5 (a) and (b). In the illustrated example, a cylindrical boss portion (projection portion) 31 is formed by integral molding with the housing 30, and arc-shaped engagement holes 32 are formed at two opposing locations around the boss portion 31. . The outer diameter of the cylindrical boss 31 is slightly smaller than the inner diameter of the screw fitting 21, and the shape, size, and position of the arc-shaped engaging hole 32 are the hooking claws 26 that are curved in an arc shape. Shape, size and position that can pass through.

FIG. 6 illustrates the manner in which the screw fitting 21 is attached to the boss portion 31 of the resin housing 30. As shown in FIG. After the hooking claw 26 is passed through the engagement hole 32 by covering the boss portion 31 and further deeply, the screwing metal fitting 21 is moved to the position shown in FIG.
When it is rotated clockwise in (b), the hooking claw 26 of the screw fitting 21 engages with the arc-shaped portion adjacent to the engaging hole 32 of the housing 30, and the screw fitting 21 is moved to the position shown in FIG. Is fixed to the housing 30 in this manner, and thus the component screwing portion structure 3
5 is provided in the housing 30. In this case, the hook 26
Since the upper edge 26a of the L-shaped horizontal portion is tapered so as to taper toward the distal end, the housing 30 is engaged so as to bite the housing 30, and the screw fitting 21 is firmly attached to the housing 30. Fixed.

In the above-described component screwing portion structure 35, since the screwing fitting 21 can be attached to the housing 30 without using a jig or a tool, the process is simplified and the screwing fitting 21 is formed. Can be incorporated into an ordinary product assembly line. Further, in the product assembly line including the mounting process of the screw fitting 21, if the screw fitting 21 is damaged due to various factors, the housing 30 may be damaged simply by turning the screw fitting 21 backward. It is possible to easily remove only the screw fitting 21 without causing the screw 21 to be removed. Therefore, it is easy to replace the damaged screw fitting, the housing 30 can be used, and it is not necessary to dispose.

The screw fitting 21 fixed to the boss portion 31 of the housing 30 as described above has the same function as a conventional resin insert or steel plate stud. That is, when a printed circuit board is attached to the screw fitting 21 fixed to the housing 30 with a screw, for example, the mounting hole 36a of the printed board 36 is screwed into the screw 21 of the screw fitting 21 as shown in FIGS. When the screw 37 is screwed and tightened in accordance with the hole 24, the printed circuit board 36 is fixed to the housing 30 side. In this case, since the extending direction of the hooking claws 26 is rightward in the circumferential direction when viewed from above, even if the screw fittings 21 rotate together when the screw 37 is tightened by turning clockwise, the hooking claws 26 remain in the housing 30. , The fixing to the housing 30 becomes more firm.

When the screw 37 is loosened by turning the screw counterclockwise to remove the printed circuit board 36, the screw fitting 21 is removed.
Even if the screw rotates together with the screw 37, the direction of the rotation is the direction in which the biting of the hooking claw 21 into the housing 30 is released, so that it is easy to remove the screw fitting 21 at the same time.

In the above-described embodiment, the present invention is applied to the case 30 made of resin, but can also be applied to a case made of steel plate. In the case of the case made of a steel plate, as shown in FIGS. 8A, 8B, and 8C,
Burr processing is performed on a predetermined position of the housing 40 to form a protruding portion 41, and arcuate engagement holes 42 are formed at two locations around the protruding portion 41. In this case, the procedure for attaching the screw fitting 21 to the projecting portion 41 of the housing 40 is basically the same as that described with reference to FIG. 5, and a description thereof will not be repeated.

The metal fitting main body 25 in the screw metal fitting 21 of the embodiment has a configuration in which the cylindrical wall 22 is divided into two parts. However, the metal body 25 is formed by a deep drawing process. ), It is also possible to adopt a configuration having a cylindrical wall. In this case, it is preferable that the hook claw be cut out with a mold blade having a special structure after drawing. It is also conceivable to manufacture it by casting. In the case where the cylindrical wall of the metal fitting body is a complete cylinder, it is possible to provide three or more hooking claws.

[0021]

According to the component screwing portion structure of the present invention,
It is possible to provide a component screwing portion structure in the housing without using a jig or a tool, and thus the process is simplified. Also, since no jigs or tools are required, it is possible to incorporate the assembly process of the component screwing portion structure into a normal product assembly line, and it is not necessary to provide another special assembly process. .

Also, in a product assembly line including the assembly of the component screwing portion structure, when the screwing metal is damaged due to various factors, only the screwing metal is easily removed without damaging the housing. Therefore, it is easy to replace the damaged screw fastener, the housing can be used, and the housing does not have to be disposed of.

When discarding a product that is no longer needed, it has been difficult to remove the resin insert or the steel plate stud from the housing in the conventional case, and it is difficult to discard the product separately from the housing. According to this, since the screw fitting can be easily removed from the housing, the housing and the screw fitting can be separately discarded. Therefore, when the housing and the screw fitting are made of different materials, it is possible to avoid a problem in the assessment when the housing and the screw fitting are discarded as they are.

[Brief description of the drawings]

FIG. 1 is a perspective view of a screw fitting used for a component screwing portion structure of a housing according to an embodiment of the present invention.

FIG. 2 is a bottom view of the screw fitting of FIG. 1;

FIG. 3 is a partially cutaway front view of the screw fitting of FIG. 1;

FIG. 4 is a plan view of a material metal plate manufactured by pressing the screw fitting of FIG. 1;

FIGS. 5A and 5B show a boss portion (protruding portion) formed on a resin housing, wherein FIG. 5A is a plan view and FIG.

6A and 6B are perspective views illustrating how to attach the screw fitting of FIG. 1 to the boss of the housing of FIG. 5; FIG. 6A is a view of a stage before the screw fitting is mounted on the boss; ) Is a perspective view of a stage in which the screw fitting is being put on the boss portion.
(C) is a perspective view of a stage in which the screw fitting is rotated after being covered with the boss portion to complete the fixing of the screw fitting to the housing.

FIG. 7 is a perspective view illustrating a procedure for fixing a printed circuit board with screws to a screw fitting fixed to a housing as shown in FIG. 6C, and FIG. 7A is a perspective view before mounting the printed circuit board; FIG. 2B is a view showing a stage in which the printed circuit board is fastened and fixed to the screw fitting with screws.

8A and 8B show a protruding portion of the housing in the embodiment in which the housing is made of a steel plate, wherein FIG. 8A is a plan view and FIG.
Is an AA cross-sectional view, and (c) is a BB cross-sectional view.

FIG. 9 is a perspective view for explaining a structure of a conventional component screw fixing portion of the housing, and is a perspective view illustrating a procedure for attaching a resin insert to a boss portion of a resin housing, and FIG. (B) is a state in which the resin insert is subsequently placed on the boss portion, and (b) is a perspective view of the stage before heating and press-fitting with a soldering iron, and (c) is a heating / It is a perspective view at the stage where press-fitting was completed and the resin insert was fixed to the boss.

FIG. 10 is a perspective view for explaining another conventional component screwing structure of a housing, illustrating a procedure for press-fitting a steel plate stud into a caulking hole of a steel housing, and FIG. Diagram of the stage before placing the steel plate stud in the caulking hole of the housing,
(B) is a perspective view showing a state in which the steel plate stud is placed on the caulking hole and before being press-fitted by the press-fitting jig.
FIG. 4 is a perspective view of a stage in which press-fitting is completed and a steel plate stud is press-fitted and fixed in a caulking hole.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Screw clamp 21 Steel plate material (metal plate material) 22 Cylindrical wall 23 Cover surface 24 Screw hole 25 Metal fitting main body 26 Hook claw 26a Upper edge 30, 40 Housing 31 Boss (projection) 41 Projection 32, 42 Engagement hole 35 Parts screw fixing part structure 36 Printed circuit board 37 Screw

Claims (6)

[Claims] 1. A lower end portion of a metal fitting body having a lid surface at an upper portion of a cylindrical wall and having a screw hole at the center of the lid surface, has a substantially L-shape in the same curved surface as the cylindrical wall, and a horizontal portion thereof is circular. In addition to having a metal screw fitting provided with a hook that has a shape extending in the circumferential direction, a projection having a cylindrical outer peripheral surface on the housing side and an arc-shaped engagement hole formed around the projection are provided. A component screw for a housing, wherein the screw is fixed to the housing by covering the protrusion with the hooking claw passing through the engagement hole, and then rotating the screw to fix the screw to the housing. Stop part structure. 2. The screw fitting according to claim 1, wherein the metal screw is formed by pressing a single metal plate, and a screw hole is formed at a center of the rectangular plate by burring and tapping. An L-shaped portion is formed by notching the vicinity of both end portions and later serving as a hooking claw, and the metal plate material is formed such that a substantially circular portion is left in a central portion which will later become a lid surface and then both side portions which become separated cylindrical walls are respectively formed. 2. The component screwing portion structure for a housing according to claim 1, wherein the metal fitting main body portion and the hooking claw are formed by drawing to form an arc cross section. 3. The horizontal extension direction of the hook claw is circumferentially rightward when viewed from above.
Part screw fastening structure of the described housing. 4. The structure of claim 1, wherein the housing is made of resin, and the protrusion and the engagement hole are formed during resin molding. 5. The housing is made of a metal plate, and a part of the housing is subjected to a burring process and a boring process to form the projecting portion and the engaging hole.
Part screw fastening structure of the described housing. 6. The component screwing portion structure for a housing according to claim 1, wherein an upper edge of the L-shaped horizontal portion of the hooking claw is tapered so as to taper toward a tip end. .