JPH118480A - Sealing structure of electric wire leader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an electric wire leader to be surely and easily sealed up with a simple structure by a method, wherein a recess is provided between the sidewall inner surface of a housing case and an opposed surface, a backup ring and an O-ring are housed in the recess, and a backup spacer is press-fitted into a space between the backup ring and the surface facing the sidewall inner surface. SOLUTION: An electric wire 18 is inserted into an electric wire insertion hole 5 provided to the sidewall of a housing case from the outside, a backup ring 14 and an O-ring 15 are housed in a recess provided to the inner face of the insertion hole 5, and the electric wire 18 is inserted into the center holes of the backup ring 14 and the O-ring 15. Thereafter, a backup spacer 21 is inserted between a surface 22 opposite to the sidewall inner surface where the recess is provided and the backup ring 14. Then, the O-ring 15 is pressed against the sidewall inner surface with a force induced by the insertion of a backup spacer 21, the O-ring is crushed and deformed by the pressure so as to press the periphery of the electric wire 18 which penetrates through the center hole of the O-ring. Through this setup, an electric wire leader is surely sealed up at the electric wire insertion hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure at a portion where an electric wire is drawn out from a case in which an electronic component or an electric circuit is housed.

[0002]

2. Description of the Related Art An electric circuit is widely used for controlling various devices, and various electronic components are used in this circuit. If water, dust, various gases, or the like adhere to such electronic components, the circuit malfunctions and stops operating. Therefore, in the control device such as equipment used in places where water is likely to be splashed, equipment used in an environment where there is a lot of dust, or equipment attached to a part where a chemical solution or the like is present around and various gases are generated. It is necessary to house electronic components and an electric circuit for the control device in a sealed case so that water, dust and chemical liquid gas do not enter the case from outside.

[0003] When housing electronic components and electric circuits in such a waterproof and dustproof case, the container and lid of the case can have a strong seal structure by various arbitrary seal structures. It is necessary to supply power to electronic components and electric circuits in the case, or to supply arbitrary signals from an external main controller, or to output signals from the electric circuit in the case to external devices, etc. It is necessary to connect devices outside the case to electric circuits and electronic components inside the case with electric wires.

[0004] Therefore, since there is a possibility that water, dust and the like may enter from a portion where the electric wire is drawn out of the case, it is necessary to seal this portion, and various proposals have been made so far. It has been proposed to adopt a structure in which the structure is sealed by passing through a packing or a bush and tightening with a cap nut, or a structure in which the inside and outside of the case are connected by a connector which can easily adopt a seal structure.

[0005]

As a conventional sealing means for drawing out the electric wire from the case as described above, the electric wire is passed through a packing or a bush and fastened with a cap nut. In addition, it was difficult to adjust the degree of tightening, and the sealing property was still uncertain, and the development of more reliable sealing means was desired. In addition, if the connector is used for the connection, the sealability will be assured.However, when used in an atmosphere of a chemical solution, when a commercially available connector is used, the material is inferior in chemical resistance and short-term. The connector part is corroded between them and cannot be used. Moreover, the connector is expensive, and furthermore, the number of assembling steps increases, and the price of the entire device increases.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a seal structure for a wire lead-out portion which has a simple structure, can be reliably and easily sealed, is easy to assemble, and has excellent chemical resistance. And

[0007]

According to the present invention, in order to solve the above-mentioned problems, a recess is formed between an inner surface of an electric wire insertion hole provided in a side wall of a storage case and a surface facing the inner surface of the side wall. A backup ring and an O-ring are housed in the concave portion, and a seal structure of an electric wire lead-out portion in which a backup spacer is press-fitted between the backup ring and a surface facing the inner surface of the side wall is constituted.

According to the present invention, the electric wire is inserted from the outside of the storage case into the electric wire insertion hole provided in the side wall of the case, and the backup ring and the O-ring are formed in the concave portion formed on the inner surface side of the electric wire insertion hole. The ring is housed, and an electric wire is inserted through the center hole of the backup ring and the center hole of the O-ring. Thereafter, when the backup spacer is press-fitted between the surface facing the inner surface of the side wall formed in the concave portion and the backup ring, the O-ring is pressed against the inner surface of the side wall by the force, and the O-ring is deformed by the collapse of the O-ring due to the pressing. The outer periphery of the electric wire passing through the center hole is pressed. Thus, the electric wire is securely sealed at the electric wire insertion hole provided in the side wall of the electric circuit storage case, and water, dust, chemical liquid gas, and the like do not enter the case.

[0009]

Embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1, 2 and 3, the upper part of the electric circuit storage case 1 for storing electronic components and electric circuits therein is opened, and a cover (not shown) is covered with a seal 9 interposed therebetween. On one of the side walls 2 of the storage case 1, a side wall 2 provided with a protrusion 3 is formed, and on the inner surface side of the storage case 1 of the protrusion 3, a recess 4 is formed. The projecting portion 3 formed on the side wall 2 is provided with an electric wire insertion hole 5.
A concave back surface 7 is provided at a predetermined distance from the inner surface 6 of the protruding portion 3 so as to face the inner surface 6, and the concave portion 4 provided between the inner surface of the protruding portion 3 and the concave back surface 7 will be described later. Backup ring is stored. A notch 11 is formed in the rear wall 10 forming the concave back 7 so as to face the electric wire insertion hole 5 of the protruding portion.

On the other hand, as shown in FIG.
A backup ring 14 having a center hole 12 at the center and an O-ring housing groove 13 formed on one surface is connected to a protruding portion 3 as shown in FIG.
Is housed in such a manner as to face the inner surface 6. At this time, the center hole 12 of the backup ring 14 and the wire insertion hole 5 formed in the protruding portion 3 are set so that their centers coincide. O-ring storage groove 13 for backup ring 14
Accommodates an O-ring 15 as shown in FIG. The O-ring 15 is set so as to protrude by a predetermined amount from the surface of the backup ring 14 in the stored state, and the center hole 16 side thereof is connected to the backup ring 1.
4 is set to be equal to or slightly inward from the inner peripheral surface of the center hole 12. The O-ring 15 is accommodated in the O-ring accommodating groove 13 of the backup ring 14 to form an O-ring assembly 17 as shown in FIG. 6, and is accommodated in the backup-ring accommodating recess 4 as shown in FIG. Is done.

In this state, the electric wire 18 is inserted from outside the case into the electric wire insertion hole 5 of the projecting portion 3 formed on the side wall 2 of the case 1. At this time, the center hole 12 of the backup ring 14
Then, the front end 19 of the electric wire 18 is inserted into the case 1 through the cutout portion 11 of the back wall 10 of the backup ring storage recess 4. Next, as shown in FIG. 8, a substantially U-shaped backup spacer 21 having an electric wire insertion groove 20 in which the lower portion is released in a U-shape is provided. As shown in FIG. Press-fit between the rear walls 10 to be formed. In order to facilitate this press-fitting, a tapered taper 23 is formed at the lower end of the backup spacer 21.

The press-fitting of the backup spacer 21 causes the O-ring 15 to be protruded from the surface 15 of the backup ring 14 by a predetermined amount with the O-ring 15 stored in the O-ring storage groove 13 of the backup ring 14 as shown in FIGS. Therefore, the protrusion is crushed and swells toward the center hole 16 where the elastic electric wire exists. Accordingly, the outer periphery of the electric wire 18 is strongly pressed by the O-ring 15, and the outer periphery of the electric wire and the inner surface 6 of the protruding portion 3 are strongly pressed, so that the portion of the electric wire insertion hole 5 is strongly sealed.

The ends of the wires inserted into the case in this manner are soldered to the respective predetermined wire connection portions. Also,
If necessary, form a binding portion on the inside of the case of the back wall 10 or provide a resin or metal member that strongly presses the outer periphery of the wire so that the wire does not come out when pulled strongly from the outside. Can be prevented from falling off. After all these operations are completed, a lid (not shown) is placed over the case. At this time, the seal 9 is interposed between the upper surface of the case and the lid and is firmly fixed with screws or the like, so that the sealing property of this portion is sufficiently ensured.

In the above-described embodiment, an example is shown in which the backup ring 14 is formed as a separate member. However, the backup ring 14 is provided in a protruding state at a predetermined position on the back surface of the lid, and automatically seals the wire insertion hole when the lid is closed. Can be performed.

[0015]

The present invention is configured as described above.
The O-ring is pressed against the inner surface of the side wall by the press-in only by the operation of press-fitting the backup spacer between the surface facing the inner surface of the side wall formed in the recess and the back surface of the backup ring.
Since the outer periphery of the wire passing through the center hole of the ring is pressed, the wire insertion hole is securely sealed, and water, dust,
Alternatively, a chemical gas or the like does not enter the case.
Therefore, the seal can be securely and easily made with a simple structure, and the assembly is easy. In addition, it is superior in chemical resistance as compared with the conventional connector, and the design of chemical resistance can be achieved only by selecting the material of the case, the O-ring and the coating of the cable. Is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of the inside of a case showing an assembled state of an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a portion A in FIG. 1 near a protruding portion of the case side wall.

FIG. 3 is a plan view of the case.

FIG. 4 is a plan view of a backup ring according to the embodiment of the present invention.

FIG. 5 is a plan view of an O-ring according to the embodiment of the present invention.

6 shows a state in which the backup ring of FIG. 3 and the O-ring of FIG. 4 are assembled, and FIG. 6 (a) is a plan view,
(B) shows a cross-sectional view.

7 is a cross-sectional view of the same portion as FIG. 2 showing a state where the member of FIG. 5 is incorporated in a case.

FIG. 8 is a plan view of a backup spacer according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Storage case 2 Side wall 3 Protrusion part 4 Concave part 5 Electric wire insertion hole 6 Inner surface 7 Concave back surface 9 Seal 10 Back wall 11 Notch part 12 Center hole 13 O-ring storage groove 14 Backup ring 15 O-ring 16 Center hole 17 O-ring assembly 18 Electric Wire 19 Tip 20 Electric Wire Insertion Groove 21 Backup Spacer 22 Back 23 Taper

Claims (3)

[Claims] 1. A recess is formed between an inner surface of an electric wire insertion hole provided in a side wall of a storage case and a surface facing the inner surface of the side wall, and a backup ring and an O-ring are stored in the recess, and a backup ring and the side wall are formed. A seal structure for an electric wire lead-out portion, wherein a backup spacer is press-fitted between the inner surface and a surface facing the inner surface. 2. The sealing structure of an electric wire lead-out part according to claim 1, wherein an O-ring housing groove is formed in the backup ring. 3. The sealing structure for an electric wire lead-out part according to claim 1, wherein the backup spacer has a substantially U-shape with a lower end opened and a tapered surface formed at the lower end.