JP2563556B2 - Digging kotatsu heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a digging kotatsu heater embedded in a floor.

2. Description of the Related Art A conventional digging heater has a structure generally shown in FIG.

That is, the heater unit 2 is fixed on the bottom surface of the kotatsu body 1 embedded in the floor, and power is supplied to the heater unit 2 through the power cord 3, the controller 4, and the connection cord 5 in sequence. . The controller 4 has a built-in control device such as a triac for controlling the amount of electricity to the heater unit 2, and has a large radiating fin for radiating the triac, a choke coil for preventing electric noise, a condenser, etc. ing.

However, with such a configuration, the controller 4 becomes hot due to the heat generated by the control device such as a triac, which causes the user to feel uneasy. In addition, when the controller 4 is covered with the brim 6 or the like, sufficient heat is not dissipated from the surface of the controller 4, and the control device is burned out. In particular, the greater the power consumption of the heater unit 2, the more remarkable the above-mentioned drawbacks become.

Therefore, an object of the present invention is to provide a dug-tat heater capable of eliminating the anxiety caused by the heat generation of the control device and appropriately radiating the heat of the control device.

Means for Solving the Problems In order to solve the above problems, the digging heater of the present invention uses a metal case as a lower part of a control box having a control device for controlling energization of a heater unit, and power control of the control device. The element is thermally bonded to a metal case, and the metal case is made to face under the floor under the bottom of the kotatsu body.

Action With the above configuration, since the control box containing the control device for generating heat is provided on the bottom surface of the kotatsu body, the user does not feel anxiety due to heat generation. Also, the lower part of the control box is a metal case, the power control element is thermally coupled to this metal case, and the metal case is exposed under the floor under the bottom of the kotatsu body, so the heat generated from the power control element is
It is surely released from the metal case into the low temperature atmosphere under the floor, and the control device cannot be burnt.

Embodiment One embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an installation diagram of an excavator heater according to one embodiment of the present invention. Reference numeral 7 denotes a kotatsu body embedded in the floor surface 8. The kotatsu body 7, the yagura body 9 and the bunten 10 constitute a heating space 11. 12 The bottom of the kotatsu body 7 13
It is a heater unit fixed on the top, and is adapted to generate heat to warm the heating space 11. Reference numeral 14 is a control box attached to the bottom surface 13 and is electrically connected to the heater unit 12 via a relay cord 15. Control box
The mounting position of 14 is on the lower side portion of the heater unit 12, is not easily affected by the heat convection by the heater unit 12, and is the position where the temperature is the lowest in the kotatsu body 7, but in order to further enhance the heat radiation effect, the control box The bottom case 16 of 14 is the bottom
It projects downward from an opening 17 provided in 13 and faces the low temperature atmosphere of the underfloor space below the bottom surface 13. Control box 14
A connection cord 18 is connected to the operation unit 19 led out of the heating space 11.

Reference numeral 20 is a power outlet attached to the side surface of the kotatsu body 7, and power is supplied to the control box 14 by a power cord 21.

FIG. 2 is an enlarged main part sectional view of the control box 14. An outer shell of the control box 14 is constituted by a lower case 16 and an upper case 22. The lower case 16 is made of metal, and is a box with no gaps so that moisture in the space under the floor does not enter. The upper case 22 is made of synthetic resin to shut off the temperature inside the kotatsu body 7. A control circuit 23 and a triac 24 which is a power control element for controlling the electric power of the heater unit 12 are provided inside the control box 14, and the triac 24 is mounted on the lower case 22 and a metal mount 25.
Is fixed through.

FIG. 3 shows an embodiment of an electric circuit diagram of the excavation heater of the present invention. 26 is a heating element, 27 is a temperature sensor that detects the temperature in the vicinity of the heating element 26, and 28 is a temperature fuse that prevents abnormal temperature rise when the temperature sensor 27 is abnormal.
The temperature sensor 27 and the temperature fuse 28 are provided in the heater unit 12.

Reference numerals 29, 30, and 31 are a volume, a fixed resistor, and a capacitor, which are sequentially connected to the temperature sensor 27 in series. Reference numeral 32 is a diac which is a switching element connected from the connection point 33 of the fixed resistor 30 and the capacitor 31 to the gate terminal of the triac 24. When the voltage at the connection point 33 exceeds a certain level, it conducts and a gate pulse is given to the triac 24. To turn on TRIAC 24. 34a, 34b, and 35 are two choke coils and capacitors that prevent electrical noise from the circuit.
Is a power switch. The temperature sensor 27 has a positive temperature resistance coefficient in which the resistance value is small when the temperature is low and increases when the temperature is high. The volume 29 and the power switch 36 are housed in the operation unit 19, and the triac
All 24 and other electronic components are contained within the control box 14.

 Next, the operation of the configuration of the present embodiment will be described.

When the user turns on the power switch 36 of the operation unit 19, the temperature of the heating space 11 is still low, so the resistance value of the temperature sensor 27 is small, and therefore the voltage applied to the capacitor 31 becomes high and the capacitor 31 is Charges quickly. That is, the potential of the connection point 33 rises quickly, the switching voltage of the diac 32 is quickly reached, the diac 32 is turned on, the triac 24 is turned on with a large conduction angle, and the heating element is close to full energization. Current flows to 26. When the temperature of the temperature sensor 27 rises due to the heat generated by the heating element 26, the resistance value of the temperature sensor 27 increases and the voltage applied to the capacitor 31 decreases, so that the connection point 33
The delay in reaching the switching voltage of the diac 32 is delayed, so that the triac 24 is turned on with a small conduction angle, and the current to the heating element 26 is narrowed. That is, as the temperature of the temperature sensor 27 increases, the triac
The conduction angle of 24 is reduced, the current flowing through the heating element 26 is reduced, the amount of heat generation is reduced, and the temperature of the heating space 11 is kept constant.

Further, the user can adjust the temperature of the heating space 11 by operating the volume 29 of the operation unit 19.
As the resistance value of the volume 29 increases, the current flowing through the heating element 26 decreases, and the temperature of the heating space 11 decreases.

In this way, the triac 24 controls the electric power by the phase control as described above, but in this case, a large amount of heat is generated. This heat is surely radiated from the surface of the lower case 16 of the control box 14 to the underfloor space which is a low temperature atmosphere under the bottom surface 13 of the kotatsu body 7 via the mount 25. Therefore, even if an abnormality such as a blanket is covered on the control box 14, it does not interfere with heat dissipation.
It is possible to keep the control circuit 24 and the control circuit 23 in a proper atmosphere, and there is no fear of burning.

Moreover, since the lower case 16 of the control box 14 is used for heat dissipation of the triac 24, a dedicated heat dissipation fin is not required, and the cost is reduced. Since the lower case 16 faces the underfloor space, it does not come into contact with human hands, and even if such a configuration is adopted, there is no safety problem at all.

In addition, the operating unit 19 has a volume 29 that generates almost no heat.
Since only the power switch 36 and
Does not become hot, does not give the user a sense of thermal anxiety, and the operating unit 19 is compact and light, which greatly improves usability.

EFFECTS OF THE INVENTION As is clear from the above description of the embodiments, the present invention uses a metal case as the lower part of the control box that contains the control device for controlling the energization of the heater unit, and uses a metal power control element for the control device. Since the metal case is thermally joined to the case so that the metal case faces under the floor under the bottom of the kotatsu body, the user does not feel anxiety due to the heat generated by the operation unit.

Further, since the heat generated by the power control element can be surely released, the control device including the power control element can be kept in an appropriate atmosphere, and there is no fear of burning.

Further, since the lower metal case of the control box is used for heat dissipation of the power control element, a dedicated heat dissipation fin is not required, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an installation drawing of a digging heater according to an embodiment of the present invention,
FIG. 2 is a sectional view of a main part of a control box of the same kotatsu heater, FIG. 3 is an electric circuit diagram used for the same kotatsu heater, and FIG. 4 is an installation diagram of a conventional kotatsu heater. 7 ... Kotatsu body, 12 ... Heater unit, 14 ... Control box, 19 ... Operating part, 24 ... Triac (power control element), 16 ... Lower case (metal case).

Claims (1)

(57) [Claims] 1. A heater unit embedded in a floor surface and provided on a bottom surface of a kotatsu body having a box shape and an upper opening, and a control box having a control device for controlling energization to the heater unit. A lower part of the control box has a metal case, a power control element of the control device is thermally bonded to the metal case, and the metal case faces the underfloor under the bottom of the kotatsu main body. .