JPH07310725A - Screw falling prevention structure - Google Patents

Abstract

PURPOSE:To properly prevent a screw from being loosened and falling via the application of simple constitution without any need of forming a screw recess section. CONSTITUTION:An elastic member 21 having a mounting hole 24 of diameter (d) smaller than the male thread outer diameter D of a screw 7 is laid on the surface of a panel 2 and fastened with a cap 20. Then, the screw 7 is threaded into the mounting hole 24 of the member 21 and the tapped hole 5 of a frame 4, thereby fastening the panel 2 to the frame 4. In this case, the member 21 is elastically deformed in a direction for diameter expansion, and holds the screw 7 with the restoring force thereof. The screw 7 is thereby prevented from being loosened and falling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw falling prevention structure suitable for fixing a panel or the like to a frame.

[0002]

2. Description of the Related Art In various electric devices, measuring instruments, etc., panels are fixed to a frame by screws. The screws are easily loosened due to vibration and the like, and may be lost if they are dropped. Therefore, various types of captive prevention structures have been conventionally proposed and implemented, and as a typical example thereof, the screw captive prevention structures shown in FIGS. 3 and 4 are known. In FIG. 3, a small-diameter shaft portion 1C is provided between the male screw portion 1A and the head portion 1B of the screw 1, and the tap hole 3 and the frame 4 formed in the panel 2 are formed.
The male screw portion 1A is screwed into the screw hole 5 of (1) to fix the panel 2 to the frame 4. When the male screw portion 1A of the screw 1 is projected from the tap hole 3 and the small diameter portion 1C is inserted into the tap hole 3, the tap hole 3 forms a slip-out preventing hole of the male screw portion 1A even if the screw 1 is loosened. ,
It is possible to prevent the screw 1 from falling off. In FIG. 4, a retaining ring 8 is attached to a normal screw 7 screwed into the screw hole 5 of the frame 4 from the screw mounting hole 6 of the panel 2. The retaining ring 8 is formed of an E-ring, resin, or the like, and has a hole having a hole diameter smaller than the outer diameter of the screw 7. Located between and. Therefore, movement of the retaining ring 8 is restricted by the panel 2, and the screw 7 is prevented from loosening and falling off.

In the conventional structure for preventing the screws from falling off as described above, when the panel 2 is fastened and fixed with a plurality of screws 1, all the screws are uniformly tightened, and the panel 2 is stably attached unless loosened. There was a problem that it could not be removed. That is, in the drop-out prevention structure shown in FIG. 3, the male screw portion 1A hits the rear surface of the panel and is not screwed into the tap hole 3, and the panel 2 is pushed up and bent. On the other hand, in the fall prevention structure shown in FIG. 4, since the retaining ring 8 pushes up the panel 2 during removal, all the screws 7
If you do not loosen on average, the panel 2 will bend.

Therefore, in order to solve such a problem,
Usually, it is necessary to provide a relief portion for the screw in the panel 2 or the frame 4 as shown in FIGS. 5 (a) and 5 (b). That is, (a) is provided with a relief portion 9 formed of a convex portion on the panel 2 side, and (b) is a relief portion 1 formed of a concave portion on the surface of the frame 4.
In such a structure, since the gap 11 is formed on the back surface side of the panel, even if all the screws 1 or 7 are unevenly tightened or loosened, the panel 2 is The panel 2 can be securely fixed and removed without being bent by being pushed up by the male screw portion 1A or the retaining ring 8.

[0005]

However, in the conventional captive prevention structure in which the panel 2 or the frame 4 is provided with a screw escape portion, the captive prevention can be prevented, but the screw itself can be loosened. There was a problem that could not be prevented. Further, when the escape portion 9 for the screw is provided on the panel 2, it is necessary to provide a place where the escape portion can be provided. It was necessary to perform a punching process for the relief part for a thick plate and press work for a thin plate.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a loose screw with a simple structure without providing a relief portion for the screw. The purpose of the present invention is to provide a screw fall-out prevention structure which can surely prevent the fall-out.

[0007]

In order to achieve the above object, the invention according to claim 1 is a screw falling prevention structure for fixing a fixed member to the mounting member by being screwed into a screw hole of the mounting member, An elastic member having a mounting hole into which the screw is screwed is arranged in the fixed member with a hole diameter smaller than the outer diameter of the male screw portion of the screw, and the mounting hole holds the screw and prevents the screw from loosening. It is characterized by doing.

[0008]

In the present invention, the mounting hole of the elastic member has a hole diameter smaller than the outer diameter of the male screw portion of the screw, and expands when the male screw portion is screwed. The restoring force of the elastic member due to this diameter expansion acts to hold the male screw portion and prevents the screw from loosening.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of a screw falling prevention structure according to the present invention, in which (a) is a state in which a screw is screwed in,
(B) is sectional drawing which shows the state before screwing in a screw.
It should be noted that, in the drawings, the same components as those in FIGS. 3 to 5 are denoted by the same reference numerals, and the description thereof will be omitted. In this figure, in this embodiment, a cap 20 accommodating an elastic member 21 made of rubber, synthetic rubber, silicone or the like is arranged on the surface of a panel 2 which is a member to be fixed, and a screw 7 is attached via the elastic member 21. The panel 2 is fixed to the surface of the frame 4 by being screwed into the screw holes 5 of the frame 4, which is a member. The screw mounting portion of the panel 2 has a flat plate shape, does not have a screw escape portion, and a screw mounting hole 22 through which the screw 7 is inserted is formed corresponding to the screw hole 5.
The cap 20 is made of resin or the like, has an insertion hole 23 at the center of the upper surface through which the screw 7 is inserted, and is fixed to the panel surface by screws or the like. The elastic member 21 has a mounting hole 24 formed of a through hole having a hole diameter d smaller than the outer diameter D of the male screw portion 7A of the screw 7, and the screw 7 is screwed into the mounting hole 24.

Thus, according to the screw drop-preventing structure having such a structure, it is possible to prevent the screw 7 from loosening and dropping. That is, when the male screw portion 7A of the screw 7 is screwed into the mounting hole 24 of the elastic member 21, the elastic member 21 elastically deforms in the radial direction due to D> d. And
The restoring force of the elastic member 21 due to this elastic deformation is the male screw portion 7
Since it works to hold A, it is possible to prevent the screw 7 from loosening and falling off. Further, the screw 7 may be an ordinary screw, and it is not necessary to provide a retaining ring or to form a tap hole or an escape portion for the screw on the panel 2 side. Therefore, when fixing the panel 2 with a plurality of screws Even if all the screws are not evenly tightened or loosened, the panel 2 can be securely attached and detached, and the panel 2 is not pushed up and bent when detached. Further, in this embodiment, since it is only necessary to dispose the elastic member 21 on the surface of the panel, it is not necessary to form the escape portion of the screw 7 on the panel 2 or the frame 4, and the manufacturing cost can be reduced.

FIG. 2 is a sectional view showing another embodiment of the present invention. In this embodiment, the relief portion provided in the conventional panel 2 is used as the mounting portion 31 of the elastic member 21. In such a configuration, the cap 20 shown in FIG. 1 is not necessary, and there is an advantage that it can be simplified. Further, since the mounting portion 31 is integrally formed at the time of molding the panel 2, no post-processing is required, and an unnecessary manufacturing cost is not required.

[0012]

As described above, according to the structure for preventing the screw from falling off according to the present invention, the elastic member having the mounting hole into which the screw is screwed with the hole diameter smaller than the outer diameter of the male screw portion of the screw is fixed. Since it is arranged on the member, when the screw is screwed into the mounting hole, the elastic member is elastically deformed in the radial direction, and the screw can be held by the restoring force. Therefore, the fixed member can be securely fixed without loosening or dropping of the screw. Further, it is not necessary to provide a relief portion for the screw, and even when fixing with a plurality of screws, it is easy to attach and remove the fixed member without uniformly tightening or loosening all the screws. .

[Brief description of drawings]

1 (a) and 1 (b) are a cross-sectional view showing a screw falling-in prevention structure according to an embodiment of the present invention in a state where a screw is screwed in and a cross-sectional view before the screw is screwed in.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a conventional example of a screw falling prevention structure.

FIG. 4 is a cross-sectional view showing another conventional example of a screw dropout prevention structure.

5A and 5B are cross-sectional views showing a conventional example in which a screw relief portion is provided.

[Explanation of symbols]

1 ... Screw, 2 ... Panel, 3 ... Tap hole, 4 ... Frame,
5 ... screw hole, 7 ... screw, 7A ... male screw part, 8 ... retaining ring, 9 ... escape part, 10 ... escape part, 20 ... cap,
21 ... Elastic member, 24 ... Mounting hole, 31 ... Mounting portion.

Claims (1)

[Claims] 1. A structure for preventing a screw from falling to fix a fixed member to the mounting member by screwing the screw into a screw hole of the mounting member, wherein the screw is screwed with a hole diameter smaller than an outer diameter of a male screw portion of the screw. An elastic member having a mounting hole is disposed on the fixed member, and the mounting hole holds the screw and prevents the screw from loosening.