JPH1117363A - Seal structure for member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal structure for a member which can maintain a high sealability regardless of variation in products and installation by thermally expanding a thermally expanding packing for sealing. SOLUTION: Electric power is supplied to a heating wire 26 from a power source through an electric wire 27. A controller controls the electric power supplied to the heating wire 26 so that a thermally expanding packing 21 may be heated for a prescribed period of time at a temperature of <=300 deg.C. When the heated packing 21 expands, the gap between the packing 21 and a cable 9 is sealed. Since the gap between the packing 21 and cable 9 is sealed by heating the packing 21 in the above-mentioned way, a high sealability can be maintained regardless of the parts variation and different tightening states, etc., of parts among products. Namely, the airtightness of a case 13 can be maintained without strictly controlling the dimensional accuracy and the installed states of parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing structure for sealing an opening of a member.

[0002]

2. Description of the Related Art Generally, in an automatic meter reading system, a network control device is provided between a center and a microcomputer meter. The network control device is housed in a case, and a cable connected to the network control device is taken out of the case through an opening provided in the case. At this time, the opening is sealed to make the case airtight.

FIG. 4 is a view showing a conventional sealing structure. As shown in FIG. 4, when the cable 103 is penetrated through the opening provided in the case 101 to seal the opening, a cable gland 105 in which a packing 111 is provided is attached to the opening. Ground fixing screw 1
09 is screwed with the cable gland 105, and the packing retainer 113 is screwed with the cable gland 105.

[0004] Then, the cable 103 is connected to the packing 111.
Penetrate inside. 107 is an O-ring. Further, the cable gland 105 is fixed to the case 101 by tightening the gland fixing screw 109 and the packing retainer 113.

[0005]

However, in such a sealing structure, there are variations in the shape of the cable, the size of the through hole of the packing, the hardness of the rubber material forming the packing, and the like. There has been a problem that such variations due to the product and variations due to the work such as the tightness of the packing press affect the sealing performance of the opening.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a sealing structure of a member capable of maintaining high sealing performance irrespective of variations due to products and construction. is there.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a member sealing structure for sealing an opening of a member by passing a cable through an opening provided in the member. Provided cable glands,
A sealing structure for a member, comprising: a thermal expansion packing provided inside the cable gland; and the cable passed through the thermal expansion packing, wherein the thermal expansion packing is thermally expanded and sealed.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Embodiments will be described in detail. FIG. 1 is a schematic configuration diagram of the automatic meter reading system. As shown in FIG. 1, the center 1 is connected to a network control device 5 via a public line network 3, and the network control device 5 is connected to a microcomputer meter 7. Public network 3
The network controller 5 and the network controller 5 are connected by a cable 9, and the network controller 5 and the microcomputer meter 7 are connected by a cable 11.
The center 1 sends commands such as automatic meter reading to the microcomputer meter 7, and the microcomputer meter 7 sends data such as meter reading values to the center 1.

FIG. 2 shows a case 1 for accommodating the network control device 5.
FIG. As shown in FIG. 2, the network control device 5 is housed in a case 13, and the case 13 is provided with two openings. Cable glands 15 in each opening
a, the cable glands 15b are attached, and the cables 9 and 11 pass through the insides of the respective cable glands 15a and 15b.

Next, a member sealing structure according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, a cable gland 15a provided with a thermal expansion packing 21 therein is attached to the opening 16 of the case 13, a gland fixing screw 19 is screwed to the cable gland 15a, and the cable gland 15a is fixed to the case 13. Let it. Thermal expansion packing retainer 2 on cable gland 15a
3 are screwed together, and the cable 9 is inserted into the thermal expansion gasket 23, the thermal expansion gasket 21, and the cable gland 15a.
Through.

A sensor 25 is mounted on the thermal expansion packing 21, and this sensor 25 is connected to a control unit (not shown) (not shown).
Connected to. A heating wire 2 is provided inside the thermal expansion packing 21.
6 is provided, and the heating wire 26 is connected to a power supply (not shown) by an electric wire 27. The controller adjusts the power supplied from the power supply to the heating wire 26 according to the temperature measured by the sensor 25.

The O-ring 17 is a ring-shaped rubber packing used to make the case 13 and the cable gland 15a adhere to each other. The ground fixing screw 19
A ring-shaped screw for fixing the cable gland 15a to the case 13.

The heat expansion packing 21 has a hole having a size approximately equal to the outer diameter of the cable 9 and is made of a heat expansion rubber material which expands in volume by heating. Thermal expansion packing holder 23
Has a hole approximately the same size as the outer diameter of the cable 9.
The sensor 25 is a thermocouple, a thermistor, or the like, and detects the temperature of the thermal expansion packing 21.

The procedure for sealing the opening 16 will now be described. Electric power is supplied to the heating wire 26 from a power supply via an electric wire 27. Using the sensor 25, the control device controls the supplied power so that the temperature of the thermal expansion packing 21 is heated to 300 degrees or less for a predetermined time. The heated thermal expansion packing 21 expands, and the gap between the thermal expansion packing 21 and the cable 9 is sealed.

As described above, according to the present embodiment, since the heat-expandable packing 21 is heated to expand and seal,
High sealing performance can be maintained without being affected by differences in construction such as variations in parts between products and tightening conditions. In other words, the case 13 can maintain high confidentiality without strict control of the dimensional accuracy of components and the contents of construction.

Further, since the thermal expansion packing 21 is expanded by supplying electric power from an external power supply device, the construction is easy. Although the seal structure in the case 13 of the network control device 5 has been described, the present invention relates to the case 1 of the network control device 5.
It can also be used for members other than 3.

[0017]

As described above in detail, according to the present invention, it is possible to provide a sealing structure of a member capable of maintaining high sealing performance irrespective of variations due to products and construction.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an automatic meter reading system.

FIG. 2 is a view showing a case 13 for storing the network control device 5;

FIG. 3 is a diagram illustrating a member sealing structure according to an embodiment of the present invention.

FIG. 4 is a diagram showing a conventional sealing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Center 3 ... Public line network 5 ... Network controller 7 ... Microcomputer meter 9, 11 ... Cable 13 ... Case 15 ... Cable gland 16 ... Opening 17 … O-ring 19… Ground fixing screw 21… Thermal expansion packing 23… Thermal expansion packing holder 25… Sensor 26… Heating wire 27… Electric wire

Claims (3)

[Claims] 1. A sealing structure for a member that seals an opening of the member by passing a cable through an opening of the member, the cable gland provided on the member, and a thermal expansion provided inside the cable gland. A sealing structure for a member, comprising: a packing; and the cable passed through the inside of the thermal expansion packing, wherein the thermal expansion packing is thermally expanded and sealed. 2. The member sealing structure according to claim 1, wherein the member is a case of a net control device. 3. The network control device according to claim 2, wherein the network control device is provided between a public line and a microcomputer meter.