JPH07318079A - Electric heater - Google Patents

Abstract

PURPOSE:To increase a heating effect by providing auxiliary electrodes aside from electrodes at both the ends of a planar heater, changing an electric current feed to the auxiliary electrodes depending on room temperature and changing an applied voltage to the planar heater based on electric current feeding positions. CONSTITUTION:In a 'strong' operation, an electric current is fed to electrodes 4a and 4b at both the ends of a planar heater 4. When room temperature is detected and the 'strong' operation is switched to 'intermediate' and ''weak'' operations by a thermostat or switches or the like, the electric current feed to the electrode 4b at the lower end of the heater 4 and auxiliary electrodes 4c to 4e is sequentially switched while changing applied voltage sequentially from the upper part to the lower part. Accordingly, the heating part of the planar heater 4 sequentially shifts downward from the upper part. For example, in the case of a ceramic planar heater 4, the base material of the heater is conductive and the temperature of a part which is not heated is not extremely lowered due to natural convection heat, since heat is transferred from the heating part and the heating part is located in the lower part. Thus, a heating effect can be increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heater using radiant heat using a flat heater.

[0002]

2. Description of the Related Art A conventional electric heater of this type is provided with an opening on the front surface of a main body 10 of the heater as shown in FIGS. 5 and 6, and the inside of the main body 10 is made of ceramic or mica. A plurality of heaters 11 are provided vertically so that one surface of the planar heater 11 is directed toward the opening side so that one surface of the heater 11 can be radiated to the outside of the main body 10, and spaces 12, 1 through which air can be ventilated in the upper and lower positions.
3, the heat shield plate 1 is provided with a certain distance between the rear and upper portions of the planar heater 11 and the main body 10.
4 is provided, and the operation switch 15 is provided on the upper surface of the main body 10.

The electric heater having the above-mentioned structure is provided in the main body 10
When the operation switch 15 of the flat heater 1 is turned on.
1 is energized and heated to radiate far infrared rays and the like from a radiation surface, and at the same time, warm air on the back surface of the planar heater 11 is released into the room by natural convection, and the room is heated by radiant heat and natural convection. Is.

A thermostat (not shown) and a change-over switch 16 are provided for automatically stopping the energization of one flat heater when the room is warmed, and the "strong" is switched to the "weak" to heat the room. The area and heating output were reduced.

[0005]

In the electric heater having the above-mentioned structure, since the flat heater 11 is provided with a heater made of ceramic or mica, the temperature of the heater rises even during heating operation. It takes time, and radiant heat does not come out immediately. In addition, it took a long time for the room temperature to rise.

Similarly, even if the changeover switch 16 or a thermostat (not shown) is used to re-energize the planar heater 11 after the energization of the heater 11 is stopped, the above-mentioned problem occurs. Further, since the radiation area is small, there are problems that it feels cold and that the room temperature drops immediately.

[0007] To solve this, the actual Kaihei 2-88
As described in Japanese Patent Laid-Open No. 94-94, one or more resistors are formed on a sheet in a strip shape and over the entire surface, an intermediate terminal is formed at an intermediate position of the resistor, and the terminals are arbitrarily selected to be energized and heated. Although a method of changing the output without changing the area has been considered, there are problems that productivity is low and cost is high because several resistors are formed over the entire surface.

[0008]

The electric heater according to the present invention solves the above-mentioned problems, and the invention according to claim 1 provides electrodes on both ends of a planar heater made of ceramic or mica. An auxiliary electrode is formed in the middle, and a means is provided for energizing the lower electrode and each auxiliary electrode, and changing the applied voltage depending on the energized portion to the auxiliary electrode.

In addition to the invention according to claim 1, the invention according to claim 2 is such that the energization point on the common side of the planar heater is always under the planar heater.
In addition to the invention according to claim 1, the invention according to claim 3 has a structure in which, in addition to the operation switch, a quick warming switch for changing the voltage and energizing the lower electrode and the auxiliary electrode is provided.

[0010]

With the above construction, in the invention described in claim 1, in the case of "strong" operation, the electrodes at both ends of the planar heater are energized to sense the room temperature, and a "medium" temperature is detected by a thermostat or a changeover switch. , When switching to "weak", the energization to the electrode at the lower end of the heater and the auxiliary electrode are switched from top to bottom while changing the applied voltage, so the heat generating part of the planar heater goes down from top to bottom. In a ceramic flat heater, the heater substrate itself is a conductor, and even in a place where heat does not occur, the heat conduction and heat generation from the heat generating part are at the bottom, so the temperature does not drop extremely due to natural convection heat. There is no.

Since the planar heater made of mica has a resistor wound around the mica insulator, the heat conduction is small, but a certain temperature remains even in a place where heat is not generated by convective heat. As a result, even if the output of the electric heater drops, heat is generated from the entire heater, and therefore the radiation area does not decrease.

Further, even when the operation of the electric heater is switched to "strong", the heat remains in the entire heater, so that the time from the start up to the stabilization is shortened and the heating of the room can be accelerated.

Further, in the invention according to claim 2, since the common electrode is at the bottom, "medium", "weak", "rapid warming"
In this case, there is an advantage that the heat generating part is located below the heater and heat is easily transferred to the upper part, and the heat distribution of the entire heater is less likely to be unbalanced.

According to the invention of claim 3,
If the quick heating switch is turned on while the operation of the electric heater is stopped, only the lower part of the heater generates heat in the same manner as above, and the temperature of the heater rises due to heat conduction or convection heat. Then, when the operation switch is turned on, the heat remains in the heater itself, so that the time from the start up to the stabilization is shortened, and the heating of the room can be accelerated.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the electric heater of the present invention will be described below with reference to FIGS. In the electric heater of the present invention, an opening is provided in the front surface of the main body 2 fixed on the stand 1, a protective guard 3 is attached, and a planar heater 4 made of ceramic is vertically or somewhat inclined in the main body 2. The flat heater 4 is provided and installed with electrodes 4a and a common electrode 4b on both ends thereof, and auxiliary electrodes 4c, 4d and 4e for "medium", "weak" and "quick warming" are provided between them. And lead plates 5a, 5b, 5c, 5d, which are crimped with lead wires,
A heat shield plate 6 is arranged at a constant interval between the rear side and the upper side of the flat heater 4 on which the 5e is formed. 9 is provided and configured.

The electric circuit of the electric heater constructed as described above is constructed as shown in FIG. In FIG. 4, 20 is a current fuse, 21 is a fast-warming transformer, and 22 is a "medium" / "weak" transformer.

Next, the operation of the electric heater constructed as above will be described. First, when the operation switch 7 is turned on and the changeover switch 8 is set to "strong", the electrodes 4a and the common electrode 4b at both ends of the planar heater 4 are energized to heat the entire surface of the heater. Then, heating is performed by radiant heat and convective heat. Next, when the changeover switch 8 is set to "middle", the common electrode 4b at the lower end of the planar heater 4 and "middle" are set.
The auxiliary electrode 4c is energized to generate heat only between the two electrodes. Since the heater base material itself of the planar heater 4 is a conductor,
Even in a place where heat is not generated, the temperature does not drop due to heat conduction and convection heat from the heat generating portion, and radiant heat is generated from the entire heater.

Then, when the changeover switch 8 is changed to "weak", the common electrode 4b at the lower end of the planar heater 4 and
The "weak" auxiliary electrode 4d is energized to generate radiant heat from the entire heater in the same manner as above. If the voltage applied to each electrode is the same, the watt density increases as the heater heating area decreases, and the surface temperature of the heater increases, so it is necessary to lower the voltage and decrease the output as the heating area decreases. (This does not apply if there is a margin with respect to the temperature of the heater base or the main body 2) Generally, the applied voltage to 4a> the applied voltage to 4c> the applied voltage to 4d.

Next, the quick warm switch will be described.
When the quick heating switch 9 is turned on while the operation is stopped, the common electrode 4b at the lower end of the planar heater 4 and the "quick heating" auxiliary electrode 4e are energized, and the entire heater generates heat as described above. At this time, the voltage is lowered so that the temperature of the main body 2 rises and the heater heats up so that radiant heat is hardly felt (4e).
Voltage applied to the electrode <voltage applied to 4d) is applied between the electrodes.

When the operation switch 7 is turned "ON" (when the changeover switch 8 is "strong"), the common electrode 4b at the lower end of the planar heater 4 and the "quick warming" auxiliary electrode 4e are connected to the electrodes at both ends. And the heating operation is started.
Since the heater has already generated heat, the temperature rises from the start to the stabilization quickly, and radiant heat comes out quickly and the room can be heated quickly. Also, because the voltage is dropped, it saves electricity bills.

[0021]

Since the electric heater of the present invention is constructed as described above, in the invention of claim 1, the heat is generated from the entire heater even when the heating output is lowered, so that the radiation area is increased. The heating effect can be improved without decreasing. In addition, even when the power is switched to "strong", the time from the start up to the stabilization is short, and the heating of the room can be quick.

According to the second aspect of the invention, since the heat generating portion in the heater is at the bottom, the heat distribution of the heater is uniform and the heat radiating area is not narrowed except "strong". In addition, the start-up of the operation at the time of quick warming becomes faster.

In the invention according to claim 3,
Even when the operation is stopped, if the quick-warming switch is turned on, the heater is energized, and the time from the start-up to the stabilization after the start of operation is shortened and the heating of the room can be accelerated.

[Brief description of drawings]

FIG. 1 is a perspective view of essential parts showing an embodiment of an electric heater of the present invention.

FIG. 2 is a cross-sectional view of essential parts showing an embodiment of the electric heater of the present invention.

FIG. 3 is a perspective view of an essential part showing one embodiment of the back surface of the planar heater of the electric heater of the present invention.

FIG. 4 is an electric circuit diagram of an embodiment of the electric heater of the present invention.

FIG. 5 is a perspective view of a main part of a conventional electric heater.

FIG. 6 is a sectional view of a main part of a conventional electric heater.

[Explanation of symbols]

 2 main body 4 planar heaters 4a, 4b electrodes 4c, 4d, 4e at both ends auxiliary electrodes 7 operation switch 8 changeover switch 9 fast warm switch

Claims (3)

[Claims] 1. An electric heater having a flat heater vertically installed in a main body having a front opening, wherein auxiliary electrodes are formed separately from electrodes at both ends of the flat heater, and the auxiliary electrodes are formed depending on room temperature. An electric heater comprising means for changing the energization of the heater and changing the voltage applied to the planar heater according to the energized portion. 2. The electric heater according to claim 1, wherein an energization point on the common side of the planar heater is always provided from a lower portion of the planar heater. 3. The electric heater according to claim 1, wherein a quick warming switch for changing the voltage and energizing the auxiliary electrode is provided separately from the operation switch of the main body.