JP3380990B2 - Temperature abnormality monitoring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for monitoring an abnormal temperature in a bus duct or the like. 2. Description of the Related Art Bus ducts are widely used as a power distribution material suitable for large currents in buildings and factories, but if a conductor connection bolt is loosened or forgotten to be tightened at a connection portion thereof, the conductor becomes abnormal. It is necessary to monitor the temperature rise, which may cause dielectric breakdown or short-circuit to ground. Conventionally,
In such monitoring, a temperature monitoring system using a thermo label or a temperature monitoring system that performs centralized management by a monitoring panel is known. A thermo label is a label that changes its color irreversibly due to a rise in temperature. The label is attached to a connection portion, the discoloration is visually checked, and an abnormal rise in temperature is detected. In addition, the temperature monitoring system attaches a sensor box containing a thermostat using bimetal to a predetermined location of the bus duct, connects each sensor box with a signal cable, connects it to a monitoring panel, and monitors intensively here Things. When the temperature becomes higher than the set temperature, the alarm lamp of each sensor box is turned on, and the monitoring panel notifies the abnormality by sounding a buzzer and lighting the lamp. However, bus ducts are often laid at high places such as ceilings in buildings and factories, and thermolabels are generally small in size (1 cm diameter).
Therefore, there is a risk of overlooking even if discolored by visual observation from the floor. In addition, since the discoloration is irreversible, once the discoloration is changed, it must be replaced and cannot be reused. On the other hand, in a temperature monitoring system using a bimetal, wiring of a signal cable connecting each sensor box is required, and the work is troublesome. In addition, there is a problem that large-scale equipment such as a monitoring panel and a power supply for centralized management is required, which increases costs. SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention aims to provide a temperature monitoring device which is easily noticeable and does not require wiring or a power supply. In the sensor box, a bimetal, a slide plate integrated with the bimetal, and an alarm band with a weight attached to the tip are provided, and the weight is dropped in response to the movement of the slide plate due to the bimetal warpage. is there. An embodiment of the present invention will be described below. FIG. 1 is a schematic diagram showing the internal structure of the device of the present invention, and FIG. 2 is a schematic diagram showing the appearance of a sensor box of the device. As shown in the figure, the apparatus of the present invention mainly includes a slide plate 2 that moves due to warpage of a bimetal 1 caused by a temperature change, an alarm band 4 having a weight 5 attached to a tip thereof, and a weight support plate 3 on which the weight 5 is placed. Components. The bimetal 1 is formed by integrating a metal having a large coefficient of linear expansion and a metal having a small coefficient of linear expansion by bonding, and in this example, a long plate-shaped metal is used. The sensor box is attached to the inner wall of the sensor box front surface 21 (installation surface: surface that comes in contact with the monitoring target) shown in FIG. If there is a temperature change, slide plate 2 described later
1 was installed such that the metal on the left side of FIG. 1 was a metal having a small linear expansion coefficient and the right side was a metal having a large linear expansion coefficient. The mounting position of the bimetal is not particularly limited, but is preferably inside the sensor box installation surface where heat from the monitoring target easily conducts. An L-shaped slide plate 2 is fixed to the tip of the bimetal 1. The slide plate is composed of a vertical portion 2A fixed to the left side of the bimetal 1 in FIG. 1 and a horizontal portion 2B with its upper portion bent to the right.
An angled curved portion 2C is formed at the tip of 2B. The angled curved portion 2C is configured to reduce the contact area with the weight support plate 3 described below and reduce friction. Further, in this example, the horizontal portion 2B of the slide plate is bent in a step shape and the support piece 7 fixed to the bottom surface 22 of the sensor box.
Supported. The fixing of the support piece 7 may be performed on any surface of the sensor box. On the other hand, a weight support plate 3 is hinged to the extending direction of the horizontal portion 2B, that is, the inner wall of the right side surface 23 of the sensor box (see FIG. 2). The weight support plate 3 is a rectangular plate having a hemispherical concave portion 8 on which the weight is placed substantially at the center, and has a shaft core insertion portion 9 folded at one end, into which the shaft core 10 is inserted. Further, both ends of the shaft core 10 are held by hinges 11 attached to the right side surface of the sensor box. Normally, the other end of the weight support plate 3 is supported by the angled curved portion 2C of the slide plate. However, when an abnormal temperature rise occurs, the bimetal 1 warps with the mounting bracket 6 as a base point. As the slide plate 2 moves backward (moves to the left), it comes off the chevron curved portion 2C and rotates downward. On the inner wall of the sensor box upper surface 24, the alarm band 4 is wound and held in a roll shape via the hanging metal fittings 12. When an abnormal temperature rise occurs, the alarm zone 4 hangs down with the rotation of the weight support plate 3,
In this example, a red cloth tape (width 10 to 15 mm, length 1 m or more) was used to stand out, and a spherical weight 5 was attached to the tip thereof. The hanging bracket 12 holding the alarm band 4 faces the L-shaped metal piece 12A,
In the meantime, the roll core 12B is pivotally supported, and one end of the alarm band 4 is fixed to the roll core 12B. The alarm band 4 does not have to be wound up in a roll shape, but may be simply rolled and placed on the weight support plate. The concave portion 8 of the weight support plate is provided so that the weight does not roll on the support plate, but is not essential.
A flat weight support plate may be used, and the shape of the weight may be a cube or the like that is difficult to roll. In addition, using a flat weight support plate and a spherical weight, the weight support plate 2 is mounted on the inner wall of the sensor box.
It is also possible to attach a flat plate substantially parallel to the above, to provide a hole such as a circle in this flat plate, and to surround the weight with this hole. The apparatus of the present invention having such an internal configuration uses a rectangular box 20 as shown in FIG. The front surface 21 serving as the installation surface has magnets 25 attached to the four outer corners, and is configured to be easily attached to the monitoring target. An opening 26 is formed in the center so that the temperature from the object to be monitored is easily conducted into the sensor box. On the other hand, an opening 27 for hanging the alarm band 4 is formed in the bottom surface 22. Each surface of the sensor box is preferably made of a material having excellent thermal conductivity such as a metal. If the above-mentioned device is mounted at a predetermined location such as a bus duct connection where temperature monitoring is required, if an abnormal temperature rise occurs, the bimetal 1 warps to the left side in FIG. 1 and slides accordingly. Since the plate 2 moves to the left, the other end of the weight support plate 3 is disengaged from the chevron curved portion 2C and pivots downward. As a result, the weight 5 also falls downward, and the alarm band 4 is pulled out. If this is visually confirmed, the temperature can be monitored. Unlike the conventional thermo label, the alarm band 4 has a size that is easily noticeable, so that it is not overlooked. When resetting after the alarm band 4 hangs down, the alarm band 4 is rolled up again in a roll shape, and the weight holding plate 3 is placed on the slide plate 2 (mountain-shaped curved portion). May be set in the recess 8. At this time, roll core
Connect the handle (not shown) to 12B to the sensor box
The alarm band 4 is provided outside of the 20 and the handle is turned.
May be configured to be able to be wound. Although the above configuration uses the weight support plate 3, it is not necessary to use this. For example, the slide plate 2 is expanded, and instead of the weight support plate 3, the weight 5 is directly placed on the slide plate. In this case, a flat plate having a hole such as a circle may be attached to the inner wall of the sensor box in parallel with the slide plate 2, and the hole may surround the weight. When the bimetal is warped due to the temperature rise, the slide plate moves, but the weight slides on the slide plate because it is surrounded by the holes, and falls off when it comes off from the slide plate to pull out the alarm band 4. It is desirable to attach the warning duct 4 to the side or bottom of the bus duct so that the alarm band 4 hangs down without any trouble. As shown in FIG. 3, an opening 32 is formed in a lid plate 31 on the side of the bus duct 30, and a sensor box is attached to the opening 32 so that the opening 26 on the front corresponds to the opening 32. The inside of the bus duct is communicated,
It is configured such that both temperatures are equal without time lag. Openings 32, 2 on the installation surface of the bus duct and sensor box
6 is not essential, and may be provided as needed. In addition,
When the sensor box is installed on the bottom side plate 33 in the bus duct 30 shown in FIG.
24, and the bimetal 1 is also installed on the upper surface 24. FIG. 4 shows the connection of two insulated bus ducts of Al-Fe, 3W, 1000A, closing of both ends to allow a rated current to flow, and measuring the temperature of the center of the conductor and the junction with a thermocouple.
This shows how the temperature of each part changes until it becomes substantially constant. In the figure, is the conductor, is the temperature inside the case, is the case side plate, is the temperature of each part of the case cover plate,
Indicates the outside temperature. Here, a surface parallel to the flat bus duct conductor and penetrated by the connection bolt is a case side plate, and a surface arranged in a direction orthogonal to the case side plate is a case cover plate. This graph shows a normal temperature rise curve without abnormal heat generation. As shown, the temperature rise of the side plate is more remarkable than that of the cover plate. Is easy to detect. Since the temperature inside the bus duct also shows a temperature rise substantially similar to that of the side plate, it is apparent that it is preferable to connect the inside of the bus duct and the inside of the sensor box as described above. There are cases where the bus duct is placed vertically (side plate is on the side and the lid plate is on the bottom side) or horizontally (the side plate is on the bottom side and the lid plate is on the horizontal side). Is preferred. Although the above embodiment has been described by taking as an example the case where the present invention is applied to a bus duct, the present invention is not limited to the bus duct, but can be applied to any other places where temperature monitoring is required. As described above, according to the apparatus of the present invention, an abnormal temperature can be monitored by a device having a simple configuration without requiring a power supply or wiring. In addition, by using an easily visible alarm band, oversight can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an internal configuration of the device of the present invention. FIG. 2 is a schematic view showing the appearance of a sensor box of the device of the present invention. FIG. 3 is a schematic view of a bus duct to which the device of the present invention is attached. FIG. 4 is a graph showing a temperature rise curve near a bus duct connection part. [Description of Signs] 1 Bimetal 2 Slide plate 2A Vertical portion 2B Horizontal portion 2C Angled curved portion 3 Weight support plate 4 Alarm band 5 Weight 6 Mounting bracket 7 Supporting piece 8 Depression 9 Axis insertion part 10 Axis 11 butterfly fitting
12 Hanging bracket 12A L-shaped metal piece 12B Roll core 20 Sensor box
21 Front 22 Bottom 23 Right side 24 Top 25 Magnet 26 Opening
27 Opening 30 Bus duct 31 Cover plate 32 Opening 33 Side plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) G01K 5/00-5/72 G08B 21/00 H02G 5/06 311

Claims (1)

(57) [Claims 1] A sensor box includes a bimetal, a slide plate integrated therewith, and an alarm band having one end fixed to the sensor box and a weight attached to the other end. A temperature abnormality monitoring device, wherein the slide plate or the sensor box is hinged,
A temperature abnormality, wherein the weight is placed on a weight support plate whose end is supported by a slide plate, and the weight is dropped in response to movement of the slide plate due to warpage of the bimetal. Monitoring device.