JPS644237Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a planar electric heating device such as an electric carpet or floor heating heater, and particularly relates to a planar electric heating device using a heater wire and a sensor wire for temperature detection. It is something.

[Prior art and its problems]

Conventionally, as a planar electric heater such as an electric carpet, a heater wire is wired in a meandering manner between a backing material (insulating material) and a surface material, and a sensor wire for temperature detection is installed along the heating wire. It is being In this type of planar electric heater, the sensor wire is wired in contact with the heater wire or as close as possible to the heater wire in order to detect the temperature of the heater wire as accurately as possible. Therefore, the temperature of the sensor wire is almost the same as the temperature of the heater wire, and the temperature regulator detects the impedance of the sensor wire and compares it with a set value to turn on or off the power to the heater wire. Note that the sensor wire has a characteristic that the impedance decreases as the temperature increases.

This type of flat electric heater does not pose any problem if the entire surface is in a state of almost uniform heat dissipation, but if there is a part of it that is in a state of poor heat dissipation, for example, because a cushion is placed on it, the temperature in that part can become very high. This is because the temperature setter detects the impedance of the entire length of the sensor wire, so even if there is a temperature rise in part of the sensor wire, if the temperature in other parts is low,
This is because the impedance over the entire length of the sensor wire does not decrease significantly, and current continues to flow through the heater wire.

[Means for solving problems and their effects]

In order to solve the problems of the prior art as described above, the present invention provides a planar electric heating device including a heater wire wired in a meandering pattern and a sensor wire for detecting temperature. The heater wire is characterized by being separated from the parallel portion of the heater wire and wired in the middle of the parallel portion.

In this way, the temperature of the sensor wire is lower than the temperature of the heater wire under normal heat dissipation conditions, so the temperature controller is set so that the power to the heater wire can be turned on and off while the temperature of the sensor wire is lower than before. It turns out. On the other hand, if a localized area with poor heat dissipation occurs, the temperature of the sensor wire in that area will be almost the same as the temperature of the heater wire, so the temperature change rate of the sensor wire will be extremely large, and the impedance change over the entire length will also change. It will have a big impact. Therefore, current to the heater wire is cut off while the local overheating temperature is lower than before.

〔Example〕

FIG. 1 and FIG. 2 each show an embodiment of the planar electric heater of the present invention. 1 is the back material, 2 is the surface material, 3 is the heater wire wired between them,
4 is a sensor wire. Both embodiments are the same in that the heater wire 3 is wired in a meandering manner. In the embodiment of FIG. 1, the sensor wire 4 enters the parallel section of the meandering heater wire 3 and therein the U
It is wired in a turned shape away from the heater wire 3. In the embodiment shown in FIG. 2, the sensor wire 4 is wired with a larger meandering pitch than the heater wire 3, with its parallel portion passing through the center of the parallel portion of the heater wire 3. The embodiment shown in FIG. 2 is used when the intersection of the heater wire 3 and the sensor wire 4 does not pose a problem, such as when the back surface material 1 and the surface material 2 are soft.

In electric carpets, etc., the distance between the parallel parts of the heater wire is 20 to 50 mm, and if the sensor wire is wired in the middle of the parallel part with a distance of at least one quarter of the distance from the heater wire, the temperature of the sensor wire will be the same as that of the heater wire. 2 to 10 from the temperature (around 50℃)
℃ becomes lower. In other words, the sensor wire controls the temperature of the heater wire at a set temperature that is 2 to 10 degrees Celsius lower than the conventional temperature. On the other hand, if a local overheating occurs, the amount of heat dissipated in that area is extremely small, so the temperature of the sensor wire becomes equal to the temperature of the heater wire, and the rate of temperature rise of the sensor wire (from the set temperature) increases, so the temperature cannot be adjusted. The device operates earlier, and local overheating temperature can be kept lower than before.
In particular, the rate of change in impedance of sensor wires tends to decrease as the temperature increases, so set the temperature by 2 to 10 degrees Celsius at the general control temperature of around 50 degrees Celsius.
Lowering the temperature has the effect of lowering the temperature of locally overheated areas (approximately 70°C or higher) by 10 to several tens of degrees Celsius.

[Effect of idea]

As explained above, according to the present invention, the sensor wire is separated from the parallel part of the meandering heater wire and wired in the middle of the parallel part, so that temperature control is possible even when the temperature of the sensor wire is normally lower than that of the heater wire. On the other hand, when local overheating occurs, the sensor wire in that area reaches the same temperature as the heater wire, so the rate of temperature rise increases and the response to local overheating becomes faster, keeping the temperature rise in the local overheating area lower than before. There are advantages.

[Brief explanation of the drawing]

FIGS. 1 and 2 are partially cutaway plan views showing essential parts of a planar electric heater according to an embodiment of the present invention, respectively. 1... Back material, 2... Surface material, 3... Heater wire, 4... Sensor wire.

Claims (1)

[Claims for Utility Model Registration] (1) A planar electric heating device including a heater wire wired in a meandering pattern and a sensor wire for detecting temperature, wherein the sensor wire is separated from the parallel portion of the heater wire. , a planar electric heating device characterized in that wiring is wired in the middle of the parallel portions. (2) Utility model registration The planar electric heating device according to claim 1, in which the sensor wire is wired at a distance from the heater wire by at least one quarter of the distance between the parallel parts of the heater wire.