JPH01300624A - Case for sensor with radio transmitter - Google Patents

Abstract

PURPOSE:To attain the safety not in contact with a high voltage charging part by installing an antenna of a radio transmitter to the inside of an insulation protection plate of a metallic case. CONSTITUTION:A radio transmitter 5, an antenna 6 and a temperature sensor employing a sensor switch 7 made of a shape memory alloy or the like are contained in a metallic case 2. Then the antenna 6 is arranged to the inside of an insulation protection plate 4 made of a glass plate or a ceramic plate fitted to an antenna opening window 3 of the metallic case 2. Thus, even when the metallic case 2 is fitted in contact with a high voltage conductor 30 or the like, the antenna 6 is not in contact with the high voltage charging part and the danger of the transmitter 5 destroyed by a high voltage is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sensor gage with a wireless transmitter for high voltage surge resistance.

[Prior Art] A system that detects the status of various devices using various sensors such as a temperature sensor, magnetic sensor, pressure sensor, or limit switch, and transmits the detection signal to a monitoring station by wireless method for various monitoring and control purposes. In some cases, a battery-powered wireless transmitter and various sensors are combined, and the detected output signal is transmitted from the antenna of the wireless transmitter and received by a wireless receiver for monitoring and control.

Such a radio transmitter is housed in a plastic case and provided with an antenna, or as shown in FIGS. 9 and 10 showing the front and side views, a part of the metal case 40 is insulated and the antenna 41 is installed in the metal case. It is exposed from 40.

[Problems to be Solved by the Invention] When it is necessary to attach the above-mentioned sensor to a high-voltage conductor to detect abnormal temperatures, etc., the plastic case deteriorates due to tracking caused by corona discharge of the high-voltage conductor. Since they cannot withstand long-term use, metal cases are used for high-voltage charging parts. However, conventional wireless transmitters housed in metal cases cannot transmit radio waves unless the antenna is exposed, and the slanted antenna is exposed.Therefore, there is a risk that the antenna may come into contact with a high-voltage charging part and be destroyed. . Therefore, the wireless detection system described above has a problem in that it cannot safely detect abnormal temperatures of high voltage conductors, etc.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a case for a sensor with a wireless transmitter that can withstand high voltage and is safe and free from the above-mentioned dangers for a high voltage charging unit.

[Means for Solving the Problems] In order to achieve the above object, the sensor case with a wireless transmitter of the present invention uses a wireless transmitter, an antenna, and a sensor switch such as a shape memory alloy in a metal case. The antenna is placed inside an insulating protection plate such as a glass plate or a ceramic plate attached to the antenna opening window of the metal case, and the antenna comes into contact with the high voltage charging part to which the metal case is attached. This is to prevent discharge from occurring from the high voltage charging part to the antenna.

[Function] The above-mentioned sensor with a wireless transmitter is attached to a high-voltage charging part such as a high-voltage conductor, and the sensor switch is installed to turn on or off in response to an abnormal rise in temperature at the location. The detection operation causes the wireless transmitter to output a detection signal, and the detection signal radio wave is radiated from the antenna through the insulating protection plate in the opening window. A receiver receives this detection signal and issues an alarm of abnormal temperature rise.

The antenna is installed inside the insulating protection plate of the antenna opening window of the metal case and is not exposed, so even if a sensor with a wireless transmitter is attached to a high-voltage live part, the antenna will not come into contact with the high-voltage live part. Furthermore, since there is no discharge from the high voltage charging part to the antenna, the danger of the transmitter being destroyed by high voltage is prevented.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the first case of a sensor case with a wireless transmitter of the present invention.
FIG. 2 shows the front side of the embodiment, and FIG. 2 shows a partial cross section of the side surface, where l is a sensor with a wireless transmitter, 2 is its metal case, and 3 is an antenna opening window on the front side of the metal case 2. , 4 is an insulating protection plate such as a glass plate or a ceramic plate which is airtightly attached to the antenna opening 3.

5 is a radio transmitter housed in the metal case 2; 6 is its antenna; this antenna 6 is placed inside the insulating protection plate 4 in the antenna opening 3, and emits radio waves through the insulating protection plate 4; do.

Reference numeral 7 denotes a sensor switch serving as a temperature sensor, which is made of a shape memory alloy and configured to respond to a predetermined temperature, and is installed in the metal case 2. This sensor switch 7 generates a detection signal of abnormal temperature rise by closing or opening a detection circuit in response to an abnormal rise in temperature at the place where it is attached due to contact with the metal case 2, and this detection signal output is transmitted wirelessly. It is radiated from the antenna 6 of the aircraft 5 as a signal radio wave.

8 is an indicator light such as an LED provided on the side surface of the metal case 2 to display during operation, and 9 is a mounting plate that protrudes from the bottom of the metal case 2.

FIGS. 3 and 4 are cross-sectional views of other embodiments, and the same reference numerals as in FIGS. An antenna opening window in the case 2; 4 an insulating protection plate such as a glass plate or a ceramic plate airtightly attached to the antenna opening window 3;
is a radio transmitter housed in a metal case 2, and 6 is an antenna.

Reference numeral 7 denotes a sensor switch serving as a temperature sensor, which is composed of a switch using a shape memory alloy such as a Ni-Ti alloy, a switch using an inclination of a mercury surface, or the like. 9 is a mounting plate at the bottom of the metal case; 10 is a circuit element component of the wireless transmitter 5; 11
is a battery such as a lithium battery.

FIG. 5 shows still another embodiment, 2 is a metal case of the sensor 1 with a wireless transmitter, 3 is an antenna opening window of the metal case 2, 4 is a glass plate airtightly attached to the antenna opening window 3, and 4 is a ceramic plate. An insulation protection plate such as a board, 5 is a wireless transmitter, 6
7 is an antenna, and 7 is a sensor switch composed of a shape memory alloy spring 71, a bias spring 72, and an opening/closing contact 73. 8 is an indicator light such as an LED, 9 is a plate attached to the bottom of the metal case, 10 is a crystal oscillator, a coil, a transistor, and other circuit elements of the wireless transmitter 5, and 11 is a battery.

FIG. 6 shows yet another embodiment, in which 2 is a metal case of a sensor 1 with a wireless transmitter, 3 is an antenna aperture window, 4 is an insulation protection plate for the antenna aperture window 3, 5 is #, a wire transmitter, 6 is an antenna, 7 is a sensor switch using shape memory alloy, etc.
9 is mounted on a board.

FIG. 7 shows the sensor 1 with a wireless transmitter and the receiver on the receiving station side that receives the detection signal radio waves transmitted from the sensor and issues an alarm. includes a radio transmitter 5, an antenna 6,
A sensor switch 7 using a shape memory alloy or the like and a battery 11 are housed, and the radio waves radiated from the antenna 6 through the insulating protection plate 4 of the antenna opening window 3 of this metal case 2 are as follows.
The signal is received by the antenna 22 of the receiver 21 of the receiving station 2011'ill, and the relay 23 outputs an alarm signal Ov. 24 is an AC power supply section.

As shown in FIG. 8, the sensor 1 with a wireless transmitter for temperature detection is equipped with the sensor switch 7 and the wireless transmitter 5 as described above. Attach with etc.

If the sensor switch 7 serving as a temperature sensor is installed in contact with the high voltage conductor etc. 30 in this way, the high voltage conductor etc.
When the temperature rises abnormally, the shape memory alloy sensor switch 7 inside the metal case 2 responds, causing the wireless transmitter 5 to output a detection signal of abnormal temperature rise, and the detection signal radio wave is radiated from the antenna 6. . At the same time, the LED
An indicator light 8 such as the above blinks to notify an abnormal temperature rise.

The detection signal transmitted from the wireless transmitter-equipped sensor 1 is received by the antenna 22 at the receiving station 20 and alerts the high voltage conductor 30 to an abnormal temperature rise. If a large number of sensors 1 with wireless transmitters are attached to a high voltage conductor 30 at appropriate intervals and the oscillation frequencies of their detection signals are made different,
It is possible to know at which point of the high voltage conductor 30 the temperature has increased abnormally.

The radio transmitter 5 avoids the broadcast frequency band and uses the oscillation frequency in the 140 MHz band, or in some cases 300 to 3308 H2.
etc., the oscillation output is 15μV / at a distance of 1001
m or less, the carrier ON-OFF control method is used, the receiver 21 uses a superheterodyne method, and signal detection is performed using a squelch signal. Further, the operating temperature of the shape memory alloy sensor switch is, for example, about 75° C., so that it can operate stably without malfunction.

The size of the metal case is 30mm high, 30Iu+ wide,
The length is preferably about 501 m.

As described above, if the sensor with a wireless transmitter of the present invention is used to detect an abnormal rise in temperature of a high voltage conductor, the antenna 6 can be attached to the open window 3 even if the metal case 2 is attached in contact with the high voltage conductor. Since it is provided inside the insulating protection plate 4 and is not exposed, there is no possibility of contact with high voltage charging parts, and there is no possibility of discharge from the high voltage charging parts to the antenna, so there is a risk of the transmitter being destroyed by high voltage. It is possible to use the present invention safely and for a long period of time even with a high voltage charging part of 60 KV, and it becomes possible to realize a wireless system for detecting abnormal temperatures of high voltage conductors, etc.

Note that the above-mentioned detection of abnormal temperatures of high voltage charging parts by the sensor with a wireless transmitter can be applied not only to the high voltage conductor 30 but also to detecting overheating of high voltage charging parts such as transformers, power receiving equipment, motors, etc. I can do it.

[Effects of the Invention] As mentioned above, in the present invention, the antenna of the wireless transmitter is installed inside the insulating protection plate of the metal case, so it is safe because it does not come into contact with the high voltage charging part, and it is safe to use. Detection can be performed using a sensor with a wireless transmitter.

[Brief explanation of the drawing]

FIG. 1 is a front view of one embodiment of the present invention, FIG. 2 is a side view thereof, FIGS. 3 and 4 are sectional views of other embodiments, and FIG. 5 is a sectional view of another embodiment of the invention. , FIG. 6 is a perspective view of yet another embodiment, FIG. 7 is a diagram showing a sensor with a wireless transmitter and a receiver of the present invention, FIG. 8 is a diagram showing the state of use, and FIGS. 9 and 10. These are a front view and a sectional view of a conventional example. 1: Sensor with wireless transmitter 2: Metal case 3: Opening window for antenna 4: Insulation protection plate Patent applicant Furukawa Electric Co., Ltd. Agent Patent attorney Oka 1) Kikudomari Figure 1 Figure 3 Figure 2 Figure 4 Figure 5 Figure 6127 Figure 7 Broom 81!1 Figure 9 Figure 10

Claims (1)

[Claims] A radio transmitter having an antenna and a sensor switch are housed in a metal case, an insulating protection plate is provided in the antenna opening window of the metal case, and the antenna is arranged inside the insulating protection plate. Case for sensor with wireless transmitter.