JP2979782B2 - Assembly method of ultrasonic sensor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for assembling an ultrasonic sensor device used for predictive maintenance of gas-insulated power equipment.

[0002]

2. Description of the Related Art Generally, a power device such as a conductor is housed in a tank, and a sensor device for predictive maintenance is attached to a gas-insulated power device in which an insulating gas is sealed in the tank to detect a partial discharge in the tank. That is being done. The sensor device for predictive maintenance is arranged outside the tank so that the reliability of the power equipment is not reduced by the presence of the sensor.

Recently, a sensor is arranged inside the tank to detect sufficient information before failure such as partial discharge generated inside the tank in distinction from noise, and a lead wire is drawn out of the tank to connect with a measuring instrument. A connection configuration has been proposed. As described above, the ultrasonic sensor device for installing the ultrasonic sensor inside the tank and detecting gas corona discharge, movement of metal particles, adhesion to an insulator surface, or poor contact of a conductor is shown in FIG. Have been proposed. In this case, as shown in the sectional view of FIG. 6, a thick cylindrical sound absorbing material 22 made of polyurethane foam is arranged inside a cylindrical metal case 21. Then, the ultrasonic sensor main body 23 is arranged in the hollow portion of the sound absorbing material 22. A metal net 24 for shielding is arranged at the front opening of the metal case 21, and a rear end 25 of the metal case 21 is fixed to a mounting flange 26. A terminal 27 for connection to the outside is provided on the mounting flange 26.

[0004] The ultrasonic sensor device 2 configured as described above.
8, the metal case 21 is inserted into the opening 30 provided in the housing 29 of the power device, and the mounting flange 26 is screwed to the housing 29 for installation. Note that a packing member 31 is provided to protect the airtightness between the housing 29 and the mounting flange 26. The lead terminals 32 of the ultrasonic sensor main body 23 and the terminals 33 of the connection terminal 27 are connected by lead wires 34.

Thus, the ultrasonic sensor body 23 is
It is put inside the metal case 21 and the metal case 21 and the shielding wire mesh 24 prevent the noise from being mixed by the electromagnetic action and the electrostatic action. At the same time, the noise of the ultrasonic vibration propagating from the metal case 21 is absorbed and prevented by the sound absorbing material 22, thereby enabling accurate detection.

[0006]

However, in the conventional ultrasonic sensor device as described above, the metal case 21 in which the ultrasonic sensor main body 23 is installed has the mounting flange 26.
And must be firmly fixed so that it does not fall into the housing 29. Therefore, the rear end 25 of the metal case 21 is welded to the mounting flange 26. However, according to this, there is a problem that the sound absorbing material 22 made of urethane foam melts out due to the heat at the time of welding, and does not function as the sound absorbing material. Therefore, the metal case 21 is attached to the mounting flange 26.
It is attempted to fix the rear end portion 25 by spot welding at several places. However, according to this, the heat at the time of welding may damage the sound absorbing material 22 or reduce the strength of the joint. There was a problem that it was enough.

The present invention has been made in view of the above points, and an object of the present invention is to prevent a sound absorbing material installed in a metal case from being damaged by heat, and to make the metal case and the It is an object of the present invention to provide an ultrasonic sensor device that can firmly adhere to a supporting flange.

[0008]

According to the ultrasonic sensor device of the present invention, a lead wire of an ultrasonic sensor main body which is inserted into and adhered to the inside of a hollow hole of a first sound absorbing material formed of an elastic material into a cylindrical shape. Is connected to the terminal of the connection terminal portion of the mounting flange, and then a second cylindrical member having a predetermined length is provided between the first sound absorbing material around the lead wire and the mounting flange. Arranging the sound absorbing material with the first sound absorbing material, and then winding a porous Teflon pipe around the outer circumference of the first and second sound absorbing materials;
Furthermore, a cylindrical metal case with a shielding wire mesh attached to the front opening is placed on the outer periphery of the porous Teflon pipe, and the rear end of the metal case is partially welded to the flange to assemble the apparatus. It is characterized by having done.

[0009]

With this configuration, the distance between the welded portion of the metal case and the ultrasonic sensor main body is increased to prevent damage to the sound absorbing material of the ultrasonic sensor main body due to heat during welding. Further, the metal case and the flange supporting the metal case can be firmly fixed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the method for assembling an ultrasonic sensor device according to the present invention will be described below with reference to FIGS.

First, as shown in FIG. 1, a front opening 2 of a cylindrical metal case 1 is bent inward, and a shielding wire mesh 3 is brazed. The rear end 4 of the metal case 1 is open.

Next, as shown in FIG. 2, the lead wire 8 of the ultrasonic sensor body 7 which is inserted into and adhered to the inside of the hollow hole 6 of the first sound absorbing material 5 formed of an elastic material in a cylindrical shape. Is connected to the terminal 11 of the connection terminal portion 10 of the mounting flange 9.

Next, as shown in FIG.
A second sound-absorbing material 12 having a predetermined length, for example, divided into one portion in the circumferential direction, is formed between the first sound-absorbing material 5 and the mounting flange 9 around the periphery of the first sound-absorbing material 5. Next to the sound absorbing material 5, a porous (for example, Teflon) pipe 13 is wound around the first and second sound absorbing materials 5 and 12.
One end of this porous pipe 13 is
It is inserted into the ring-shaped groove 15 inside the ring groove 14.

Further, as shown in FIG. 4, the outer periphery of the porous pipe 13 is covered with the metal case 1 shown in FIG. Partial welding is performed on the inner side of the ring groove 14 by spot welding or the like.

Finally, as shown in FIG. 5, the mounting flange 9 is disposed inside the housing 16 through the opening 17 provided in the housing 16 in which the metal case 1 housing the ultrasonic sensor body 7 is provided. As described above, the housing 16 is hermetically attached to the housing 16 by bolts 19 via O-rings 18.

As described above, according to the present invention, the lead wire of the ultrasonic sensor main body which is inserted into and adhered to the inside of the hollow hole of the first sound absorbing material formed into a cylindrical shape is connected to the connecting terminal portion of the mounting flange. Terminal and then the first
Of a predetermined length between the sound absorbing material and the mounting flange.
Is formed into a cylindrical shape, and then the first and second
A porous pipe is wound around the outer periphery of the sound absorbing material, and a cylindrical metal case having a shielding wire mesh attached to a front opening is covered on the outer periphery of the porous pipe. The ultrasonic sensor device is formed by connecting to an attachment flange.

[0017]

As described above, according to the present invention, (1) since the ultrasonic sensor and the flange can be integrated, the ultrasonic sensor device can be easily mounted.

(2) Since it is structured to be mounted from the outside of the gas-insulated power equipment tank, it can be easily replaced even in case of breakage.

(3) When the metal case and the flange are spot-welded, the sound-absorbing material does not deform due to heat because the porous Teflon pipe separates from the ultrasonic sensor main body and the welded portion.

(4) Since the inclination of the ultrasonic sensor can be adjusted while the porous pipe is attached, variations in the inclination of the sensor are reduced, and the detection sensitivity of the ultrasonic wave is stabilized.

The following effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a metal case of the present invention.

FIG. 2 is an explanatory view of an assembling process according to one embodiment of the present invention.

FIG. 3 is an explanatory view of an assembling process according to an embodiment of the present invention.

FIG. 4 is an explanatory view of an assembling process according to one embodiment of the present invention.

FIG. 5 is an explanatory view of an assembling process according to an embodiment of the present invention.

FIG. 6 is a sectional view of a main part showing a conventional ultrasonic sensor device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal case 2 front opening of metal case 3 wire mesh for shielding 4 rear end of metal case 5 sound absorbing material 6 hollow hole of sound absorbing material 7 ultrasonic sensor body 8 lead wire 9 mounting Flange for connection 10 ... Terminal for connection 11 ... Terminal 12 ... Sound absorbing material 13 ... Pipe 14 ... O-ring groove 15 ... Ring-shaped groove 16 ... Housing 17 ... Opening of housing 18 ... O-ring 19 ... Bolt

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01N 29/24 G01R 31/12 H02B 13/065 H02G 5/06

Claims (1)

(57) [Claims] 1. A lead wire of an ultrasonic sensor main body, which is inserted into and adhered to a hollow hole of a first sound absorbing material formed in a cylindrical shape, is connected to a terminal of a connection terminal portion of a mounting flange. Next, a cylindrical second sound absorbing material having a predetermined length is arranged between the first sound absorbing material and the mounting flange around the lead wire, and then the first and second sound absorbing materials are arranged. A porous pipe is wound around the outer periphery of the sound absorbing material of No. 2, and a cylindrical metal case with a shielding wire mesh attached to the front opening is put over the outer periphery of the porous pipe. A method for assembling an ultrasonic sensor device, wherein the ultrasonic sensor device is formed by partially welding the mounting flange.