JP7415659B2 - housing - Google Patents

Description

The present invention relates to a housing in which a first case and a second case are connected by a drop-off prevention screw.

BACKGROUND ART Conventionally, as a case of an electronic device, there is a case including an upper case and a lower case, as described in Patent Document 1, for example. The upper case and lower case disclosed in Patent Document 1 are stacked so that their openings face each other, and are fastened together using a plurality of fastening screws. In order to prevent the fastening screws from being lost, some of these types of casings use drop-off prevention screws that prevent the screws from falling out of the case even if the screws are loosened.

In such a case, in order to replace the internal battery or perform maintenance, the inside of the case may be opened by loosening the tightened screws. In the case of a case in which the upper case is screwed to the lower case from above, in order to open the case, the threaded portions of all the screws must be removed from the female threaded portions of the lower case. Normally, loosen multiple screws one by one, and then remove the upper case from the lower case after all screws have been loosened.

When loosening multiple screws one by one to open the housing, the screw loosened first rests on the female thread due to its own weight, enters the female thread due to vibration, and the threads of the male thread and the thread of the female thread engage. There is. In such a case, the upper case cannot be removed from the lower case even after all the screws have been loosened.

Japanese Patent Application Publication No. 2012-230998

If the screw becomes engaged with the female thread after loosening the screw, the operator must loosen the screw again with a screwdriver or pinch and pull it with his or her fingers to release the engaged state. When there are a large number of screws, or when the operator is forced to take an awkward posture in order to loosen the screws, the task of disengaging the screws becomes complicated.

An object of the present invention is to provide a housing that can hold screws that connect cases together in a loosened state and prevent the screws from engaging with female threads.

In order to achieve this object, the casing according to the present invention includes a first case having a through hole for screw insertion, and a drop-off prevention screw inserted into the through hole and held in the first case. , a casing comprising: a second case combined with the first case; and a female threaded portion provided on the second case and into which the falling-off prevention screw is screwed, the first case An engagement rib that protrudes inward of the first case is provided on the inner surface of the part where the through hole opens, and the engagement rib is arranged in a direction in which the fall prevention screw is pulled out from the first case. The screw is configured to come into contact with a male threaded portion of the falling-off prevention screw by moving to a position where the falling-off preventing screw is turned in a direction in which the falling-off preventing screw is loosened while the male threaded portion of the falling-off preventing screw is in contact with the engagement rib. Therefore, the male thread portion bites into the engagement rib.

In the case, the engaging rib has an inclined surface connected to a hole wall surface of the through hole, and the inclined surface gradually penetrates the through hole as it goes inside the first case. It may be inclined toward the outside in the radial direction of the hole.

In the present invention, in the case, the engagement ribs may be provided at a plurality of positions surrounding the through hole.

In the present invention, the falling-off preventing screw is held in the first case with the male threaded portion of the falling-off preventing screw biting into the engagement rib. Therefore, it is possible to provide a housing that can hold the screws that connect the cases together in a loosened state and prevent the screws from engaging with the female threads.

FIG. 1 is an exploded perspective view of a casing according to the present invention. FIG. 2 is a sectional view of the main parts in the fastened state. FIG. 3 is a sectional view of the main parts in a state where the falling-off prevention screw is loosened. FIG. 4 is a sectional view of the main part in a state where the drop-off prevention screw is held. FIG. 5 is a cross-sectional view showing a state in which the male thread portion bites into the engagement rib. FIG. 6 is an enlarged plan view showing a part of the inner surface of the first case. FIG. 7 is a partially cutaway perspective view of the first case.

Hereinafter, one embodiment of the casing according to the present invention will be described in detail with reference to FIGS. 1 to 7. The housing 1 shown in FIG. 1 includes a first case 2 located on the upper side in FIG. The first case 2 and the second case 3 according to this embodiment are each formed into a rectangular tube shape with a bottom, and as shown in FIG. They are connected by screws 4.

As shown in FIG. 1, the first case 2 has through holes 5 for screw insertion at four corners, respectively. Falling prevention screws 4 are passed through these through holes 5, respectively. As shown in FIG. 7, the through hole 5 opens into a cylindrical boss 6 that projects from the inner surface 2a of the first case 2. As shown in FIG. As shown in FIG. 6, four reinforcing ribs 7 are provided on the outer periphery of the boss 6. As shown in FIG. The fracture position in FIGS. 2 and 7 is the position indicated by the line II-II in FIG.

The inner diameter of the boss 6 is larger than the hole diameter of the through hole 5. Therefore, a part of the inner surface 2a of the first case 2 is exposed in an annular shape between the inside of the boss 6 and the through hole 5. An engaging rib 11 according to the present invention is provided on this annular portion 2b. A detailed description of the engagement rib 11 will be given later.

As shown in FIG. 1, the second case 3 is provided with cylindrical bosses 12 at four corners, respectively. These bosses 12 come into contact with the reinforcing ribs 7 of the bosses 6 of the first case 2 when the first case 2 is attached to the second case 3, as shown in FIG. Nut members 13 are inserted into and fixed to the four bosses 12 of the second case 3, respectively. The nut member 13 constitutes a "female threaded portion" in the present invention. The drop-off prevention screw 4 passed through the through hole 5 of the first case 2 is screwed onto this nut member 13, as shown in FIG. A plurality of bosses 14 are provided at the center of the second case 3 to attach electronic components (not shown).

The fall prevention screw 4 is for fixing the first case 2 to the second case 3, and as shown in FIG. It has 23. The diameter of the through hole 5 of the first case 2 is smaller than the outer diameter of the male threaded portion 21 and larger than the outer diameter of the shaft portion 23. When this drop-off prevention screw 4 is passed through the through hole 5, the male threaded portion 21 is screwed into the through hole 5. After the male threaded portion 21 passes through the through hole 5, the thin shaft portion 23 enters the through hole 5. When the shaft portion 23 is inserted into the through hole 5 in this manner, the male thread portion 21 and the head portion 22 essentially act as a stopper, so that the fall prevention screw 4 can be easily removed from the first case 2. cannot be removed. That is, the fall prevention screw 4 is movably held in the first case 2.

As shown in FIG. 7, the engagement rib 11 provided on the first case 2 is a portion of the inner surface 2a of the first case 2 where the through hole 5 opens (an annular portion 2b inside the boss 6). It protrudes from the inside of the first case 2. The engagement ribs 11 according to this embodiment are provided at a plurality of positions surrounding the through hole 5, respectively. In this embodiment, as shown in FIG. 6, engaging ribs 11 are provided at positions dividing the circumference of the through hole 5 into three equal parts. These engaging ribs 11 have an inclined surface 11a connected to the hole wall surface of the through hole 5. The inclined surface 11a is gradually inclined toward the outer side in the radial direction of the through hole 5 as it goes toward the inside of the first case 2 (the front side of the page in FIG. 6).

When disassembling the casing 1 constructed in this way, first loosen the drop-off prevention screw 4 from the assembled state shown in FIG. Then, as shown in FIG. 3, with the male threaded portion 21 removed from the nut member 13, an operator (not shown) grasps the falling-off prevention screw 4 with his or her fingers and pulls it out of the first case 2. When the falling-off prevention screw 4 moves in the direction in which it is pulled out from the first case 2, the male threaded portion 21 comes into contact with the inclined surface 11a of the engagement rib 11.

Next, while the male threaded portion 21 is in contact with the engagement rib 11, the fall prevention screw 4 is turned in the loosening direction. By turning the fall prevention screw 4 in this manner, the thread 21a (see FIG. 5) of the male threaded portion 21 is guided radially inside the through hole 5 by the inclined surface 11a and bites into the engagement rib 11. It becomes like this. That is, the male threaded portion 21 performs a so-called thread cutting operation on the engagement rib 11, and the male threaded portion 21 bites into the engagement rib 11, as shown in FIGS. 4 and 5.

As the male threaded portion 21 bites into the engagement rib 11 in this way, even if the operator releases his/her finger from the fall prevention screw 4, the fall prevention screw 4 remains detached from the nut member 13 and remains in the first case 2. Retained. After all four fall-off prevention screws 4 are held in the first case 2 as described above, by removing the first case 2 from the second case 3, the fall-off prevention screws 4 are caught on the nut member 13. The housing 1 is disassembled without any trouble.
Therefore, according to this embodiment, it is possible to hold the fall prevention screw 4 that connects the cases in a loosened state and prevent the fall prevention screw 4 from engaging with the female thread (nut member 13). A housing can be provided.

The engagement rib 11 according to this embodiment has an inclined surface 11 a connected to the hole wall surface of the through hole 5 . The inclined surface 11a is gradually inclined toward the outer side in the radial direction of the through hole 5 as it goes toward the inside of the first case 2. Therefore, the threads 21a of the male threaded portion 21 come into contact with the engagement ribs 11 and are guided inward in the radial direction of the through hole 5, making it easier for the threads 21a to bite the engagement ribs 11. As a result, the fall prevention screw 4 can be easily held.

The engagement ribs 11 according to this embodiment are provided at a plurality of positions surrounding the through hole 5, respectively. Therefore, since the thread cutting operation by the male threaded portion 21 can be started at a small rotation angle, the falling-off prevention screw 4 can be held quickly. In addition, compared to the case where the engagement rib 11 is provided all around the through hole 5, the resistance when the thread 21a crosses the engagement rib 11 can be reduced, so it can be prevented from falling off with a small amount of force. The screw 4 can be held in the first case 2.

In the embodiment described above, an example was shown in which the engaging ribs 11 are provided at three locations around the through hole 5. However, the number of engagement ribs 11 can be changed as appropriate, such as one, two, four or more.
Further, in the embodiment described above, an example was shown in which the sloped surface 11a is formed on the engagement rib 11, but the sloped surface 11a does not need to be formed. Even in this case, the thread 21a of the male threaded portion 21 can bite into the engagement rib 11, so that the same effect as in the embodiment described above can be obtained.

DESCRIPTION OF SYMBOLS 1... Housing, 2... First case, 2b... Annular part, 3... Second case, 4... Falling prevention screw, 5... Through hole, 11... Engagement rib, 11a... Inclined surface, 13... Nut member (Female threaded portion), 21...Male threaded portion, 22...Head, 23...Shaft.

Claims (2)

a first case having a through hole for screw insertion;
a fall-off prevention screw having a shaft portion thinner than the male threaded portion between the male threaded portion and the head, and inserted into the through hole and held in the first case;
a second case combined with the first case;
A casing comprising a female threaded part provided in the second case and into which the falling-off prevention screw is screwed,
An engaging rib that protrudes inward of the first case is provided on the inner surface of the first case at a portion where the through hole opens,
The engaging rib is configured to come into contact with the male threaded portion of the falling-off preventing screw when the falling-off preventing screw moves in a direction in which the falling-off preventing screw is pulled out from the first case, and the engaging rib is configured to come into contact with the male threaded portion of the falling-off preventing screw, and is also configured to contact the male threaded portion of the falling-off preventing screw. has an inclined surface connected to
The inclined surface gradually slopes toward the outside in the radial direction of the through hole as it goes inside the first case,
A casing characterized in that when the male threaded portion of the falling-off prevention screw is turned in a direction in which the falling-off preventing screw is loosened while the male threaded portion is in contact with the engaging rib, the male threaded portion bites into the engaging rib. . The housing according to claim 1 ,
The housing, wherein the engagement ribs are provided at a plurality of positions surrounding the through hole.

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