JPH08330771A - Anti-dew condensation heat insulating mechanism of equipment equipped with electric circuit - Google Patents

Abstract

PURPOSE: To prevent dewdrops from being formed inside the case of an equipment equipped with an electric circuit by a method wherein a heater is brought into contact with the metal frame of an equipment case. CONSTITUTION: Arm anti-dew condensation heat insulating mechanism is composed of an equipment case metal frame 2 which keeps an equipment at a certain temperature always, a heater 8 treats the metal frame 2 coming into contact with it, a temperature detector 4 which detects the temperature of the equipment case metal frame 2, a control 5 which controls the heater 8 in temperature, an electrical circuit 3 which conducts heat coming into contact with the equipment case metal frame 2, an electrical circuit board 10 which conducts heat coming into contact with the electrical circuit 3, an operational switch 9 which is controlled by the control 5 to operate the electrical circuit 3, and an equipment case housing 1 which protects the equipment case metal frame 2. The heater 8 coming into contact with the equipment case metal frame 2 is made to release heat, the equipment case metal frame 2 is heated so as to be kept at a set temperature, and the equipment case metal frame 2 is brought into contact with the electric circuit board 10 of the electrical circuit 3 to heat the inside of an equipment case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat retaining mechanism for preventing dew condensation on equipment having an electric circuit.

[0002]

2. Description of the Related Art Conventionally, this kind of dew condensation preventing mechanism is to always fill the inside of the casing with dry air as shown in the dew condensation preventing mechanism for the casing of electronic equipment in Japanese Utility Model Laid-Open No. 59-070398. Are used for the purpose of preventing the occurrence of condensation caused by changes in the environment.

FIG. 5 is an explanatory view showing an example of a conventional housing of an electronic device concerning dew condensation prevention. In FIG. 5, an exhaust hole 21 having a check valve on one side surface of a housing 20 of an electronic device, a blower fan 23 arranged inside the housing 20 and coupled to the exhaust hole 21, and a housing 20 of the housing 20. An outside air introduction hole 24 having a backflow prevention valve on the other side surface, a dehumidifier 25 arranged inside the housing 20 and coupled to the outside air introduction hole 24, and a dehumidifier 2
5 for introducing air into the housing 20 connected to
6 and an opening / closing door 27 forming a part of the housing 20 of the electronic device.
And a switch 28 having a timer which is located between the housing 20 and the opening / closing door 27 (the opening position of the opening / closing door 27 is indicated by 27A) and which operates in conjunction with the timer of the switch 28. There is a housing of an electronic device composed of the blower fan 23. The operation is such that an electronic circuit and an electronic component mounted inside the housing 20 raise or lower the temperature inside the housing 20 when the electronic device is energized or de-energized to cause expansion or contraction of air, and A pressure difference occurs inside the body 20.

By utilizing the pressure difference, when the air inside the housing 20 expands and the pressure increases, the amount of the expanded air is exhausted from the exhaust hole 21 and the air inside the housing 20 contracts and the pressure drops. Occasionally, the outside air is sucked in from the outside air introduction hole 24 and the dehumidified air passes through the dehumidifier 25 and is guided to the inside of the housing 20 by the introduction hole 26, so that the inside of the housing 20 is always filled with dry air. State is maintained.

[0005] Further, as shown in the dew condensation preventing mechanism of the housing of electric equipment in Japanese Utility Model Laid-Open No. 01-054395. In an electrical equipment housing in which a housing is formed from a resin material, a mesh braided using a plurality of types of metal wires is mounted so as to provide a gap with the inner surface of the housing, and the mesh is provided in a part of the housing. An electric device housing which is bonded to a body and further applies a voltage to a mesh, and is used for the purpose of preventing the occurrence of dew condensation caused by an environmental change.

FIG. 6 is a block diagram showing an example of a conventional electrical equipment casing for preventing dew condensation. In FIG. 6, a metal mesh 47 is a mesh braided with a plurality of types of metal wires, is protected by an insulating material 48 as necessary, and is mounted with a gap provided between the inner surface of the housing 41 and the metal mesh 47.
Is connected to a metal body 49 provided on a part of the housing by, for example, soldering.

The electric equipment casing configured as described above has one
When shielding a wide frequency band from 00 Hz to 100 MHz, a conductive metal mesh 47 is connected to a metal body 49 provided on a part of the housing, and this metal body 49 is connected to a good ground to the outside of the housing. By performing (grounding), an effect of shielding electromagnetic waves in a wide frequency band can be obtained. Therefore, the conductive metal mesh 47 can cover the wall surface of the non-conductive casing 41, the non-conductive opening can be made as small as possible, and a wide range of frequencies can be obtained due to the electromagnetic wave shielding effect of each metal. The effect of shielding electromagnetic waves in the band is obtained.

Further, the electric component 4 mounted in the housing 41
If the connection cable for wiring between the two is sewn between the meshes of the metal mesh 47, the optimum mounting position can be obtained even if the number of the electric components 42 is increased or decreased or the shape is changed. After determining, the wiring route can be freely determined, making it an extremely convenient connection cable connection method.

Further, by applying a voltage to the metal mesh 47 to prevent dew condensation at low temperatures, Joule heat is generated to prevent dew condensation. Regarding the voltage application of the metal mesh 47, a thermoswitch or the like is installed inside the housing so that the voltage can be applied only at a low temperature (for example, −40 ° C.).

[0010]

Problems to be Solved by the Invention
The casing of the electronic device disclosed in Japanese Patent Publication No. 98 has a structure in which the dehumidified air is filled in the casing to prevent dew condensation in the casing. However, even the dehumidified air contains water that cannot be dehumidified due to the air temperature at the time of dehumidification. Therefore, there is a problem that dew condensation occurs in the air inside the housing as the temperature outside the housing rises and falls.

Further, in the electric equipment casing of Japanese Utility Model Laid-Open No. 01-054395, a voltage is applied to the metal mesh to generate Joule heat to warm the casing, but the temperature inside the casing is not controlled and the equipment is not. There is a problem that a temperature difference inside and outside the housing causes a difference in temperature inside and outside the housing, which causes a dew condensation action.

When power is supplied and electric equipment is operated in the dew condensation state as described above, there is a problem that a short circuit or the like occurs in an electric circuit portion in the electric equipment due to the dew condensation action.

[0013]

In order to solve the above-mentioned problems, a device housing metal frame for always keeping electric equipment warm, a heating element for contacting and warming the device housing metal frame, and the device housing. Temperature detecting means for detecting the temperature of the body metal frame, control means for controlling the temperature of the heating element from the temperature detecting means, an electric circuit section in which heat is transferred in contact with the equipment housing metal frame, and the electric circuit An electric circuit board that transfers heat by contacting the housing, an operation switch that is operated by the control means to operate the electric circuit portion, and an equipment housing exterior portion that protects the equipment housing metal frame. It

In the heat insulation mechanism for preventing dew condensation of a device having an electric circuit according to a second aspect of the present invention, the heating element comprises a heat conductor made of an aluminum plate or a copper plate and a heating wire. It is constructed by contacting the equipment and warming the metal frame of the equipment.

According to a third aspect of the invention, there is provided a heat retaining mechanism for preventing dew condensation of a device having an electric circuit, wherein the electric circuit board is made of a heat conductor surrounding the electric component, and is in contact with the metal frame of the device housing. It is configured by contacting an electric circuit part to which heat is transmitted and warming electric parts.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an outline of one embodiment of the present invention, FIG. 2 is an explanatory view showing the constitution of one embodiment of FIG. 1, and FIG. 3 is an explanatory view showing the structure of the heater of FIG. 4 is a schematic diagram showing the structure of the electric circuit board of FIG.

As shown in the block diagram of FIG. 1 and the explanatory view of FIG. 2, a heat retaining mechanism for preventing dew condensation of a device having an electric circuit unit according to the present invention includes a device housing metal frame 2 for constantly keeping the device warm. A heat conductor 11 made of a copper plate and a heating wire 1 of the heating element for contacting and warming the device housing metal frame 2 shown in FIG.
2, a temperature detector 4 for setting a set temperature for keeping the device housing warm and detecting the temperature of the device housing metal frame 2, and controlling the temperature of the heater 8 with a signal from the temperature detector 4. A control unit 5, an electric circuit unit 3 which conducts heat by contacting with the device housing metal frame 2, and an electric component unit 1 shown in FIG.
An electric circuit board 10 having a heat conductor 14 that conducts heat in contact with the electric circuit unit 3 so as to surround the electric circuit unit 3; an operation switch 9 controlled by the control unit 5 to operate the electric circuit unit 3;
A noise filter 6 for removing noise from power supplied to the control unit 5 and the electric circuit unit 3, a power supply unit 7 for supplying power to the control unit 5 and the electric circuit unit 3, and protection of the device housing metal frame 2 And a device housing exterior part 1.

Next, the operation of this embodiment will be described with reference to FIGS. The temperature detection unit 4 is set to a set temperature that is the room temperature in which the device having the electric circuit unit is installed. When the temperature of the equipment housing metal frame 2 is lower than the set temperature of the temperature detection unit 4, the temperature detection unit 4 sends a signal to the control unit 5, and the control unit 5 supplies power to the heater 8 to warm the heater 8. When the heater 8 is warmed, the device housing metal frame 2 in contact with the heater 8 is heated by conducting heat. The control unit 5 supplies power to the heater 8 until the temperature detection unit 4 reaches the set temperature, and keeps the device housing metal frame 2 warmed.

Further, the equipment casing metal frame 2 and the electric circuit portion 3 are in contact with each other, and the heat of the warmed equipment casing metal frame 2 is transferred to the electric circuit portion 3 to warm the electric circuit portion 3. The electric circuit board 10 surrounds the electric component 13 with a heat conductor 14, and the heat conductor 14 and the electric circuit 3
The heat conductor 14 is warmed by the contact of the heat conductor, and the air around the heat conductor 14 is warmed. Heat conductor 14
When the ambient air of the
3 is warmed indirectly. When the temperature of the equipment housing metal frame 2 becomes higher than the set temperature by the temperature detecting section 4, the temperature detecting section 4 detects that the temperature becomes higher than the set temperature, and confirms that the temperature detecting section 4 does not need to supply electricity. The control unit 5 is notified by a signal. The control unit 5 stops supplying power to the heater 8 and stops heating the heater 8. By repeatedly performing this operation, the device having the electric circuit unit can always maintain the set temperature.

By the operation described above, the metal frame 2 of the equipment housing
Is notified from the temperature detection unit 4 to the control unit 5 that the temperature is higher than the set temperature, and the control unit 5 operates the operation switch 9 in the electric circuit unit 3 so that the electric circuit unit 3 can operate only when the temperature is higher than the set temperature. Control. The control unit 5 and the electric circuit unit 3 are supplied with power output from the power supply unit 7 and from which noise has been removed by the noise filter 6. A device having an electric circuit unit operates by turning on and off the operation switch.

By thus replacing the power supply unit 7 of the present mechanism with the portable power supply, the device having the electric circuit unit can be kept warm even during transportation.

[0023]

As described above, according to the present invention, in a device having an electric circuit section, the control section keeps the housing temperature at the same temperature as the outside air temperature or at least the outside air temperature, so that the outside air temperature becomes excessive. This has the effect of preventing the occurrence of dew condensation so that the heat retention temperature in the housing becomes the set temperature even if the temperature changes up and down. This makes it possible to use the equipment in an installation environment where dew condensation is likely to occur by always keeping the temperature higher than the outside air temperature, and in an installation environment in a cold region.

Further, the power supply unit 7 of the present mechanism is replaced with a portable power supply, and the apparatus having the electric circuit unit and the portable power supply are packed in a transport box, so that the mechanism can be used for portable transportation of equipment in cold regions. It can be used as such means.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an embodiment of the present invention.

FIG. 2 is an explanatory view showing a structure of one embodiment of FIG. 1;

FIG. 3 is an explanatory view showing the structure of the heater of FIG. 1;

FIG. 4 is a schematic diagram showing the structure of the electric circuit board of FIG. 1;

FIG. 5 is an explanatory view showing an example of a housing of an electronic device related to the prevention of dew condensation in the related art.

FIG. 6 is an explanatory diagram showing an example of a conventional electrical device housing relating to dew condensation prevention.

[Explanation of symbols]

 1 Equipment Housing Exterior Part 2 Equipment Housing Metal Frame 3 Electric Circuit Section 4 Temperature Detection Section 5 Control Section 6 Noise Filter 7 Power Supply Section 8 Heater 9 Operation Switch 10 Electric Circuit Board 11 Heat Conductor 12 Heating Wire 13 Electrical Parts Section 14 Heat conductor 20 Housing 21 Exhaust hole 23 Blower fan 24 Outside air introducing hole 25 Dehumidifier 26 Introducing hole 27 Opening door 28 Switch 41 Housing 42A / 42B Electrical component 47 Metal mesh 48 Insulating material 49A / 49B Metal body

Claims (3)

[Claims] 1. A device casing metal frame for always keeping an electric device warm, a heating element for contacting and warming the device casing metal frame, a temperature detecting means for detecting a temperature of the device casing metal frame, Control means for controlling the temperature of the heating element from a temperature detecting means, an electric circuit part in contact with the equipment housing metal frame to transfer heat, an electric circuit board in contact with the electric circuit part to transfer heat, and A heat insulation for preventing dew condensation of a device having an electric circuit, comprising: an operation switch controlled by the control means to operate the electric circuit part; and a device case exterior part for protecting the device case metal frame. mechanism. 2. The heating element comprises a heat conductor made of an aluminum plate or a copper plate and a heating wire, and contacts the equipment casing metal frame to warm the equipment casing metal frame. A heat insulation mechanism for preventing dew condensation of a device having the electric circuit according to 1. 3. The electric circuit board is composed of a heat conductor surrounding the electric component, and contacts the metal frame of the equipment casing to contact an electric circuit portion for transmitting heat to heat the electric component. A heat retention mechanism for preventing dew condensation of a device having an electric circuit according to claim 1.