JP2012013149A - Packing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the ease of assembly work of a casing by providing a structure facilitating the positioning of a packing and allowing the packing installed to one of members to be held even when no groove for insertion of the packing is formed in a joint between a first member and a second member.SOLUTION: The packing structure is formed by putting the packing made of an elastic member, which is circular in cross sectional shape, between the first member and the second member. In the packing structure, a clearance at parts for catching the packing between the first member and the second member is formed narrower than the diameter of the packing in its natural state. Lock projections are formed on at least a part of the packing, and lock structures for locking the lock projections are formed on at least either one of the first member and the second member, so that the packing can be locked in a predetermined position without forming a groove for insertion of the packing in both the first member and the second member.

Description

  The present invention relates to a packing structure formed by sandwiching a packing made of an elastic member between a first member and a second member in order to realize a waterproof function or the like.

2. Description of the Related Art Conventionally, a housing of an electronic device having a waterproof function is composed of, for example, a main body member (first member) having an opening and a lid member (second member) that closes the opening. A packing made of an elastic body is sandwiched between the joint surfaces.
Since a substrate on which electronic components are mounted is housed inside the housing of the electronic device, a waterproof structure using the packing is realized, preventing water from entering the housing. .
In the waterproof structure, a groove is formed so as to surround an opening of a housing in which a substrate or the like is stored, and a ring-shaped waterproof packing made of an elastic body is fitted into the groove, and the groove is formed by a lid member covering the opening. The prevention function is realized by crushing the waterproof packing protruding from the top.
The groove is provided around the opening, and the waterproof packing has an endless structure so as to fit into the groove.

In a state where the waterproof packing is fitted in the groove, even if the main body member is turned over, the waterproof packing does not easily fall out of the groove and does not shift its position. Therefore, whether the groove is provided on the main body member side or the lid member side, the waterproof packing can be prevented from falling off when the lid is opened and closed, and the waterproof packing is positioned at a predetermined position. The
Further, in a state where the waterproof packing is fitted in the groove, a part of the waterproof packing protrudes from the groove, and by pressing the cover member with the lid member, the waterproof packing is elastically deformed and crushed. The waterproof function in the gap between the prevention packing and the lid member and the gap between the waterproof packing and the main body member is realized by the repulsive force.
Such a packing structure is not limited to a waterproof structure, but is often employed when realizing a dust-proof structure, an explosion-proof structure, or the like.

JP-A-10-107454

As a packing structure adopted for such a waterproof structure, as disclosed in Patent Document 1, a packing (seal material) is interposed at a joint between a front case and a rear case constituting a casing of an electronic device. In the packing structure of the housing joint portion, one in which a groove for inserting packing is provided in either the front case or the rear case has been proposed.
The groove further has a positioning recess, and is configured to facilitate positioning of the packing when the casing is assembled by mounting the packing.

According to Patent Document 1 described above, it is necessary to form a groove for inserting a packing and to form a positioning recess. However, when it is desired to secure the maximum internal space of the housing, it is desirable that the position of the packing attached to the lid member or the like be as close as possible to the edge. In such a case, since it becomes difficult to ensure a width enough to form a groove in the joint portion, there is a case where a groove for inserting packing is not provided in the joint portion.
As described above, when the width of the joint portion is narrow and there is no space for providing a groove or a positioning recess for inserting the packing, it is difficult to position the packing and the efficiency of the assembly work is poor. There's a problem.
In addition, when the groove for inserting the packing is not provided, in the assembly work, when the packing is attached to one member and the other member is joined, the attached packing is dropped from the one member. Since it is easy, it is necessary to hold the packing, and there is a problem that the efficiency of the assembly work is poor.
Further, in order to crush the packing, it is necessary to fasten the lid member to the main body member with a screw or the like. If the fastening force is weak, the packing is not crushed and a sufficient waterproof effect cannot be obtained.

Therefore, the present invention provides a structure in which the packing can be easily positioned even when the groove for inserting the packing is not formed, and the packing attached to one member is held, and It was made for the purpose of improving assembly workability.

In the packing structure according to claim 1,
In the packing structure formed by sandwiching a packing made of an elastic member having a circular cross section between the first member and the second member,
The gap between the first member and the second member in the portion sandwiching the packing is formed narrower than the diameter in the natural state of the packing,
By forming a locking projection on at least a part of the packing and forming a locking structure for locking the locking projection on at least one of the first member and the second member, It is characterized in that the packing can be locked at a predetermined position without forming a groove into which the packing is fitted in either one member or the second member.
Note that the joint portion refers to a region where the main body member and the lid member face each other in a state where the main body member and the lid member are pressed and joined to each other by a pressing unit, and the first wall surface is The second wall surface belongs to the joint part on the lid member side, and belongs to the joint part on the main body member side.
In claim 2,
The locking projection is T-shaped,
The locking structure is formed to elastically deform and lock at least a part of the locking protrusion.

In claim 3,
The packing has an endless shape, and a linear portion is formed at least in part, and the locking projection is formed near the middle of the linear portion.
In claim 4,
The packing is sandwiched between an outer peripheral surface for packing attachment formed on the first member and an inner peripheral surface formed on the second member and facing the outer peripheral surface for packing attachment. Configured,
The total length of the inner periphery of the packing is shorter than the total length of the outer peripheral surface.

According to the packing structure according to claim 1,
In the packing structure formed by sandwiching a packing made of an elastic member having a circular cross section between the first member and the second member,
Since the gap between the first member and the second member in the portion sandwiching the packing is narrower than the diameter in the natural state of the packing,
The packing interposed in the gap between the first member and the second member is pressed and elastically deformed. Therefore, the contact surface between the packing and the first member and the contact surface between the packing and the second member are brought into a pressure contact state due to the elastic restoring force, so that the sealing effect by the packing can be obtained.
Further, by forming a locking projection on at least a part of the packing, and forming a locking structure for locking the locking projection on at least one of the first member or the second member, Since the packing can be locked at a predetermined position without forming a groove for fitting the packing in any of the first member and the second member, the first member and the second member When the two members are joined and assembled, the packing is positioned and locked at a predetermined position of either one of the members, and the assembly work of the first member and the second member can be performed efficiently. The effect is obtained.
According to claim 2,
The locking projection is T-shaped,
Since the locking structure is formed to elastically deform and lock at least a part of the locking protrusion, the packing is securely locked to the locking structure by the elastic restoring force of the locking protrusion, There is an effect that the assembly work of the first member and the second member can be efficiently performed.

In claim 3,
The packing has an endless shape, and a linear portion is formed at least in part, but the locking protrusion is formed in the vicinity of the middle of the linear portion, so that the packing is easily dropped during assembly work. The straight portion is also locked by the locking protrusion, and an effect is obtained that the assembly work of the first member and the second member can be performed efficiently.
In claim 4,
The packing is sandwiched between an outer peripheral surface for packing attachment formed on the first member and an inner peripheral surface formed on the second member and facing the outer peripheral surface for packing attachment. Because it is configured
The packing is not crushed between the first member and the second member in the fastening direction by screws or the like, but is crushed between the outer peripheral surface and the inner peripheral surface. Even if the intervals such as these are separated, a reliable packing structure can be secured, and the number of fastening points by screws or the like can be reduced.
In addition, since the total length of the inner periphery of the packing is shorter than the total length of the outer peripheral surface, when the packing is mounted on the outer peripheral surface, the packing is elastically deformed and extended. The packing is pressed and locked to the outer peripheral surface by an elastic restoring force. Therefore, the packing is prevented from falling off, so that the assembly work of the first member and the second member can be efficiently performed.

It is a disassembled perspective view of the Example of the packing structure which concerns on this invention. It is the disassembled perspective view which expanded the principal part of the said packing structure. It is a top view of the principal part of the said packing structure. It is sectional drawing of the principal part of the said packing structure.

FIG. 1 is an exploded perspective view of an embodiment of the present invention.
The packing structure according to the present invention is a waterproof packing structure used for a housing of an electronic device having a waterproof function, for example.
In FIG. 1, reference numeral 1 denotes a die-cast main body member having a substantially rectangular opening 11.
Reference numeral 2 denotes a die-cast lid member that is formed so as to close the opening 11 when pressed by the main body member 1.
3 is a waterproof packing made of an elastic body.

  The illustrated body member 1 has a substantially rectangular parallelepiped shape, and a substantially rectangular opening 11 is formed in a part of the top surface 12 thereof. The opening 11 needs a waterproof packing structure to seal an electronic circuit or the like disposed inside. A step portion 13 is formed along the edge of the opening 11, and the step portion 13 includes an inner peripheral surface 131 formed so as to be substantially orthogonal to the top surface 12 and a plane substantially parallel to the top surface 12. 132. (See Figure 4.)

The lid member 2 shown in FIGS. 1 and 2 shows an inverted state, and a step portion 21 is formed along the outer edge of the lid member 2, and the step portion 21 is substantially parallel to the lid member 2. A flat surface 211 and a wall-shaped outer peripheral surface 212 substantially orthogonal to the lid member 2 are formed. (See Figure 4.)
The planar cross-sectional shape of the outer peripheral surface 212 is substantially a quadrilateral.
In the central part of the four sides of the outer peripheral surface 212, a notch 22 is formed in a part of the outer peripheral surface 212, and a space extending from the notch 22 is provided inside the notch 22. 23 is formed, and a surrounding portion 24 is formed around the space 23 by a wall-like structure similar to the outer peripheral surface 212.
Two screw holes 25 are formed in each of two long sides of the four sides of the lid member 2. Similar screw holes 14 are formed at positions of the main body member 1 corresponding to these screw holes 25, and internal screws are formed in these screw holes 14. The screw 4 inserted into the screw hole 25 is fastened by being screwed into the screw hole 14, and the lid member 2 is pressed against the main body member.

The illustrated packing 3 has substantially the same shape as the substantially quadrilateral outer peripheral surface formed on the lid member 2, and the total length of the inner periphery of the packing 3 is slightly shorter than the total length of the outer peripheral surface. .
A T-shaped locking projection 31 extending inward from the packing 3 is formed at the central part of the four sides of the packing 3.
As shown in FIG. 3A, the head portion 311 of the locking projection 31 is formed in a size and shape that can fit into the surrounding portion 24, and the neck portion 312 of the locking projection 31 is thick. The length d is slightly larger than the width b of the notch 22, and the length c of the neck 312 of the locking projection 31 is slightly shorter than the thickness a of the notch 22.
In the above configuration, at least one of the notch portion 22 and the surrounding portion 24 has a structure corresponding to the locking structure described in the claims.

The lid member 2 having the above configuration is turned over as shown in FIG. 1, and the packing 3 is fitted to the outer peripheral surface 212.
At this time, first, one locking protrusion 31 of the packing 3 is fitted into the surrounding portion 24 at a corresponding position. As shown in FIG. 3, the thickness d of the neck 312 of the locking projection 31 is slightly thicker than the width b of the notch 22, so that the locking projection 31 made of an elastic member has a thickness d. The neck 312 is fitted into the notch 22 as shown in FIG. 3B while being elastically deformed by the die-cast hard notch 22. In this state, the neck 312 is fixed to the notch 22 by the elastic restoring force of the neck 312 and the packing 3 is positioned in the left-right direction (X direction) in the drawing.
Further, since the length c of the neck portion 312 of the locking projection 31 is formed slightly shorter than the thickness a of the notch portion 22, the neck portion 312 of the locking projection 31 made of an elastic member is made of die casting. While being elastically deformed by the hard cutout portion 22, the cutout portion 24 is fitted into the cutout portion 24 as shown in FIG. In this state, the packing 3 is positioned in the vertical direction (Y direction) in the figure by sandwiching the notch 22 of the outer peripheral surface 212 between the head 311 and the packing 3 by the elastic restoring force of the neck 312. The
In this way, if one locking projection 31 is fitted and fixed in the surrounding portion 24 at the corresponding position, the packing 3 is positioned on the outer peripheral surface 212, so that the packing 3 is detached or displaced. This makes it easier to carry out the mounting work of the packing 3. By attaching the packing 3 to the outer peripheral surface 212 while fitting the remaining three locking projections 31 to the corresponding surrounding portions 24, excellent workability can be obtained.

As described above, after mounting the packing 3 around the outer peripheral surface 212 of the lid member 2, the lid member 2 is turned over, and the lid member 2 is covered with the opening 11, and the opening 11, the lid member 2 is attached to the main body member 1, the screw 4 is screwed into the screw holes 25 and 14, and the main body member 1 and the lid member 2 are fastened. Forms a waterproof packing structure.
As described above, the housing 10 having the waterproof packing structure is configured.

FIG. 4 is a cross-sectional view of the joint portion of the housing 10 configured as described above.
As shown in FIG. 4, the distance W between the outer peripheral surface 212 of the lid member 2 and the inner peripheral surface 131 of the main body member 1 in the left-right direction in the figure is formed to be narrower than the outer diameter P of the packing 3. Has been.
Therefore, in the state of the casing 10 in which the lid member 2 and the main body member 1 are combined, the packing 3 is a gap between the outer peripheral surface 212 of the lid member 2 and the inner peripheral surface 131 of the main body member 1. They are in a state of being elastically deformed by being crushed in the left-right direction in the figure. Therefore, due to the elastic restoring force of the packing 3, the packing 3 is pressed against the outer peripheral surface 212 of the lid member 2 to obtain a sealed state in which water does not leak, and the packing 3 is pressed against the inner peripheral surface 131 of the main body member 1. As a result, a sealed state in which water does not leak is obtained.
As shown in FIG. 4, the packing 3 is not crushed between the lid member 2 and the main body member 1 in the fastening direction (vertical direction in the figure) by screws or the like, but the outer peripheral surface 212 of the lid member 2. And the inner peripheral surface 131 of the main body member 1 are crushed in the left-right direction in the figure, so that no vertical pressure in the figure is required. Therefore, even if the fastening force by the screw or the like does not sufficiently reach at a position away from the screw or the like for fastening and the lid member 2 is pushed back somewhat in the reverse direction of the fastening direction by the elastic restoring force of the packing 3, a reliable waterproof packing The structure can be secured, and the number of fastening points by screws or the like can be reduced.
As described above, a waterproof packing structure is formed by interposing the packing 3 at the joint between the main body member 1 and the lid member 2.

Although the locking structure is formed on the lid member 2, the locking structure may be formed on the body member 1 if an installation space is obtained.
Moreover, although the said notch part 22 was provided in the said outer peripheral surface 212 as a latching structure, you may provide the latching structure similar to the said notch part 22 in the said inner peripheral surface 131. FIG. When provided on the outer peripheral surface 212, the opening area of the opening 11 can be increased, and when provided on the inner peripheral surface 131, there is no projecting structure toward the opening 11 and the structure of the lid member 2 is simplified. it can.
The locking structure may be provided on at least one of the flat surface 211 and the flat surface 132. Providing on the flat surface 211 eliminates the protruding structure toward the opening 11, and providing the flat surface 132 simplifies the structure of the lid member 2.
Further, an outer peripheral surface is formed toward the lid member 2 and an inner peripheral surface is formed toward the main body member 1, but if an installation space is obtained, an outer peripheral surface is formed toward the main body member 1, An inner peripheral surface may be formed toward the lid member 2.
Further, the pressing means is not limited to a screw and a screw hole, and any other means such as a spring can be adopted as long as it is a means for pressing the main body member 1 and the lid member 2 with each other.
Further, although the locking projection is T-shaped, the shape is not limited to the T-shape as long as it can be locked to the locking structure. Also good.
Moreover, the said latching structure should just be elastically deformed and latched at least one part, such as the head or neck part of the said latching protrusion.
Furthermore, the packing need not be endless. Further, as long as a straight portion is formed on at least a part of the packing and the locking projection is formed in the vicinity of the middle of the straight portion, a triangular shape, a polygonal shape or a fan may be used even if it is not a quadrilateral shape. It may be shaped.

DESCRIPTION OF SYMBOLS 10 Housing | casing 1 Main body member, 1st member 11 Opening part 131 Inner peripheral surface 14 Screw hole, press means 2 Lid member, 2nd member 22 Notch part, Locking structure 24 Enclosure part, Locking structure 25 Screw hole, Press Means 212 Outer peripheral surface 3 Packing 31 Locking projection 311 Head 312 Neck 4 Screw, pressing means

Claims (4)

In the packing structure formed by sandwiching a packing made of an elastic member having a circular cross section between the first member and the second member,
The gap between the first member and the second member at the joint that sandwiches the packing is formed narrower than the diameter in the natural state of the packing,
By forming a locking projection on at least a part of the packing and forming a locking structure for locking the locking projection on at least one of the first member and the second member, A packing structure characterized in that the packing can be locked at a predetermined position without forming a groove into which the packing is fitted in either one member or the second member. The locking projection is T-shaped,
The packing structure according to claim 1, wherein the locking structure is formed so as to be elastically deformed to lock at least a part of the locking protrusion. 3. The packing according to claim 1, wherein the packing has an endless shape, a linear portion is formed at least in part, and the locking projection is formed near the middle of the linear portion. The packing structure described in 1. The packing is sandwiched between an outer peripheral surface for packing attachment formed on the first member and an inner peripheral surface formed on the second member and facing the outer peripheral surface for packing attachment. Configured,
The packing structure according to claim 3, wherein a total length of an inner periphery of the packing is shorter than a total length of the outer peripheral surface.

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