JPH0684330U - Dial thermometer - Google Patents

Abstract

(57) [Abstract] [Purpose] Minimize the temperature gradient in the insulating layer between the winding 5 and the temperature sensing part 1 and the measurement error contained in it. [Structure] Temperature sensing part 1, display part 3 and conduit 2 connecting them
And at least the temperature sensitive portion 1 is made of an electrical insulator. In this case, not only the temperature sensing part 1 but also the conduit 2 can be made of an electrically insulating material. Further, the sealed liquid filled in the temperature sensitive portion 1 may be an organic liquid.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dial thermometer including a temperature sensing part, a display part, and a conduit connecting them.

[0002]

[Prior art]

 The dial thermometer is the most common device for temperature monitoring, and as a structure, it consists of a temperature sensitive part placed at the place to be measured, a display part for indicating the measured temperature, and a conduit connecting them. It is made up.

The temperature sensing part is made of a cylindrical metal, and a working liquid such as mercury that expands and contracts in proportion to a change in ambient temperature is pressurized and sealed inside. The pressure change due to the temperature change of the temperature sensing part is transmitted to the Bourdon tube installed in the display part via a conduit. The operation of the Bourdon tube is proportional to the pressure change, and is instructed on the indicator surface of the instrument via gears, pointers, etc.

[0004]

[Problems to be solved by the device]

 For example, when the temperature is monitored by embedding the temperature sensing part of a conventional dial thermometer in a mold coil for a molded transformer coil whose winding is molded with resin, the thermometer temperature sensing part is made of metal. Therefore, it is necessary to secure a space for insulation corresponding to the working voltage, that is, a resin layer, between the winding and the winding. Even though the temperature sensing part is made of metal with good heat transfer, an insulating layer with a high thermal resistance between the temperature sensing part and the object to be measured is provided. The temperature monitored at is low with a large temperature gradient in the insulating layer subtracted. In this case, as a matter of course, the temperature control during operation of the transformer is performed by correcting the temperature gradient in this insulating layer with respect to the thermometer reading. However, the temperature gradient in the insulating layer, that is, the magnitude of the heat flow from the winding, which is the heating element, to the temperature-sensitive part is, by its nature, easily influenced by environmental conditions such as the temperature around the mold coil and the wind speed. It causes a big error. This becomes a problem because the insulating layer is wider and the mold coil is larger, that is, the transformer has a higher voltage and a larger capacity. An object of the present invention is to provide a dial thermometer in which a temperature gradient in an insulating layer between a charging section such as a winding and a temperature sensing section and a measurement error included in the temperature gradient are minimized.

[0005]

[Means for Solving the Problems]

 The present invention is a dial thermometer comprising a temperature sensing part, a display part, and a conduit connecting them, and at least the temperature sensing part is made of an electrically insulating material. In this case, not only the temperature sensing part but also the conduit can be made of an electrically insulating material. Further, the sealed liquid filled in the temperature sensitive portion may be an organic liquid.

[0006]

[Action]

 According to the above configuration, the temperature sensing part can be mounted closer to the winding, the temperature gradient in the insulating layer between the winding and the winding can be reduced, and the measurement error can be further suppressed. Becomes

[0007]

【Example】

 An embodiment of the present invention will be described below. In FIG. 1, reference numeral 1 is a cylindrical temperature-sensitive portion, which is made of an electrically insulating material such as plastic, glass, or porcelain. Reference numeral 2 is a conduit for transmitting a pressure change due to a temperature change of the temperature sensing unit 1 to a Bourdon tube mounted in the display unit 3. The operation of the Bourdon tube is proportional to the pressure change and is instructed on the pointing surface of the instrument via gears, pointers, etc.

Since the temperature sensing part 1 is made of an electrically insulating material as described above, when the temperature sensing part 1 is embedded in the molded coil 4 as shown in FIG. It can be made smaller than the case where 1 is made of metal. In this case, by making the temperature sensing part 1 an electrical insulator, the thermal resistance of this part is large compared to the case of metal, so the temperature gradient from the winding cannot be greatly reduced, but By reducing the distance from the winding 5, the error due to the change in the heat flow distribution during this period can be suppressed to that extent.

As another embodiment of the present invention, in the dial thermometer in the above embodiment, the conduit portion 2 may be made of an electrically insulating material such as plastic. With this configuration, it is possible to eliminate the ground metal part from the molded coil 4, and it is possible to safely mount the temperature-sensitive part 1 by embedding and swirl the conduit 2 from the temperature-sensitive part 1. .

Further, as another embodiment, mercury is generally used as the working liquid that is usually sealed in the temperature sensing part, and an organic liquid such as alcohol is used as the working liquid. That is, the temperature sensing part 1, the conduit 2 and the liquid enclosed in the temperature sensing part 1 of the dial thermometer are all made of an electrical insulator. In this way, when mounting the temperature sensitive part 1 in the molded coil 4, it is not necessary to consider the insulation of the winding 5, and the temperature sensitive part 1 can be mounted close to the winding 5. Therefore, the temperature gradient from the winding 5 becomes extremely small, and the temperature can be monitored with little error.

[0011]

[Effect of device]

 As is clear from the above description, according to the present invention, at least the temperature sensing part is made of an electrically insulating material. The temperature gradient in the insulating layer between the winding and the temperature sensing portion and the measurement error contained in it can be minimized, and the temperature monitoring of the charged electric device can be performed accurately and safely.

[Brief description of drawings]

FIG. 1 is a schematic structural diagram showing an embodiment of a dial thermometer according to the present invention.

FIG. 2 is a schematic perspective view showing a state in which a temperature sensing part of the dial thermometer shown in FIG.

[Explanation of symbols]

Reference numeral 1 is a temperature sensitive portion, 2 is a conduit, 3 is a display portion, 4 is a molded coil, and 5 is a winding.

Claims (3)

[Scope of utility model registration request] 1. A dial thermometer comprising a temperature sensing part, a display part and a conduit connecting them, wherein at least the temperature sensing part is made of an electrically insulating material. 2. The dial thermometer according to claim 1, wherein the temperature sensing part and the conduit are made of an electrically insulating material. 3. The dial thermometer according to claim 1, wherein the sealed liquid filled in the temperature sensing portion is an organic liquid.