JP2556507Y2 - Electric heater - Google Patents

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 a semiconductor heater as a heating element.

[0002]

2. Description of the Related Art In recent years, an electric hot air blower using a semiconductor heater as a heating element has been frequently used. When a hot air outlet is covered with an obstacle, an abnormal temperature rise is sensed and an automatic operation is performed. A safety device to stop the operation is incorporated.

Conventionally, this type of electric warm air blower will be described with reference to FIG. As shown in FIG.
01 is provided with a lattice-shaped intake port 102 at the front, a dust filter 103 is attached behind the intake port 102, and the blower 1
04. The blower 104 includes a motor 105, a fan 106, and a spiral casing 107. On the discharge side of the blower 104, a heating element 108 using a semiconductor heater is provided. Here, the air is heated and discharged into a room through a duct 109 as a warm air from a warm air outlet 110. In the vicinity of the hot air outlet 110 of the duct 109, an opening 111 is provided on the upper surface, and the opening 111 is provided.
A temperature sensor 112 is mounted above the device.

[0004] In the above configuration, when an obstacle 113 is placed near the front of the hot air outlet 110, the warm air coming out of the hot air outlet 110 is blocked by the obstacle 113.
Although the area around the outlet is exposed to high temperature, warm air is sucked into the main body from the opening 111 of the duct 109, and the temperature sensor 1
At 12, it is detected that the ambient temperature has reached the set temperature or higher, and the power supply to the heating element 108 is stopped to avoid operation in a dangerous state.

[0005]

However, in the above-mentioned conventional structure, the heat of the heating element 108 passes through the mounting wall surface, the ambient temperature of the temperature sensor 112 rises, and the warm air flowing from the opening 111 during normal use is used. Therefore, the temperature sensor 1
It is necessary to set the set temperature of 12 higher than the temperature of the hot air flowing out. On the other hand, when there is an obstacle 113 in front of the hot air outlet 110, the hot air temperature rises, but the hot air temperature does not rise rapidly due to the self-temperature control action of the heating element 108. There is a problem that it takes time to reach the set temperature of 112, and during that time, the main body case 101 and the intake port 102 made of resin are deformed. Conversely, there is a method in which the detection temperature is set low while maintaining the normal atmospheric temperature low while taking a distance from the mounting surface of the heater 108 and the opening 111 of the duct 109. There is a problem that the high-temperature air flowing in from 111 diffuses into the low-temperature atmosphere in the main body, takes a long time to reach a predetermined detection temperature, and the main body case and the intake port are thermally deformed.

The present invention solves the above-mentioned conventional problems. In normal operation, the ambient temperature of the temperature sensor is kept low, and when an obstacle is placed in front of the hot air outlet, the ambient temperature is quickly reduced. Temperature rise is detected by a temperature sensor,
An object of the present invention is to provide an electric hot air blower that can prevent overheating of a main body case and the like.

[0007]

In order to achieve the above object, an electric hot air blower according to the present invention comprises a blower comprising a fan, a motor and a casing housed in a main body case, and a front opening of the main body case through a discharge port of the blower. A hot air duct communicating with a hot air outlet that opens to a heating element provided with a gap on one side of an inner wall surface of the hot air duct; and and opening on the downstream extension plane of the side wall surface has a configuration that includes a temperature sensor provided in the suction side of the blower in the vicinity of the opening.

[0008]

With this configuration, a high-temperature wind passing through the heating element is provided.
Low-temperature air passing through the gap next to the heating element is generated.In normal operation, low-temperature air mainly leaks from the opening of the hot air duct and is detected by the temperature sensor, and it is determined that normal operation is performed. When an abnormality such as an obstacle is placed in the wind, the flow of the wind is blocked, so there is a backflow of high-temperature wind and a mixture of high-temperature and low-temperature air, and the temperature sensor immediately detects high-temperature hot air, An abnormal state can be detected in a short time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.

As shown in the figure, a box-shaped main body case 1, a grid-like intake port 2, a dust filter 3, a motor 4 and a fan 5
A blower 7 composed of a spiral casing 6 and a heating element 8 provided on the discharge side of the blower 7 have the same configuration as the conventional example. The outlet of the blower 7 has a hot air duct 10 bent to a hot air outlet 9 opened at the lower front of the main body case 1.
It is communicated with. An opening 11 is provided on the downstream side of the heating element 8 of the hot air duct 10, and near the opening 11,
A temperature sensor 12 is provided on the negative pressure side of the blower 7.
The heating element 8 is attached with a space 13 interposed between a part of the hot air duct 10 and the heating element 8. Further, as shown in the sectional view of FIG. 2, the gap 13 is provided on the temperature sensor 12 side of the hot air duct 10 to reduce the amount of heat transfer to the temperature sensor 12.

The operation of the electric hot air blower of the present embodiment configured as described above will be described below.

When operation is started, the fan 5 is driven by the motor 4
, And the room air is drawn into the main body case 1 from the intake port 2 through the dust filter 3. The inhaled air is circulated along the spiral casing 6 and guided from its outlet to a heating element 8 installed in a hot air duct 10, where the air is heated by the heating element 8 and is heated as hot air from a hot air outlet 9 into the room. Is discharged to Part of the wind from the blower 7 is
After passing through the gap 13 of 0, the heating element 8 heads toward the hot air outlet 9 or the opening 11 with little heating. The temperature sensor 12 mainly detects the temperature of the low-temperature air that has passed through the gap 13 and determines that the temperature is normal.

If there is an obstacle 14 near the hot air outlet 9, the flow of the hot air is obstructed, and the temperature in the hot air duct 10 increases around the hot air outlet 9, and
The high-temperature wind that has passed through the heating element 8 is strongly mixed with the wind that passes through the gap 13 and is directed toward the hot-air outlet 9 while maintaining a low temperature, so that the temperature of the hot air around the opening 11 increases. The rising warm air flows out of the opening 11. At this time, the temperature sensor 12 detects that the temperature has reached the set temperature or more, and stops the heating element 8 or the heating element 8 and the blower 7 to prevent the main body case 1 and the intake port 2 from reaching a high temperature.

As described above, according to the present embodiment, the heating element 8
An opening is provided on the top surface of the hot air duct where the heater is installed, and on the downstream side of the heating element. , The detection temperature of the temperature sensor is several tens d from the average temperature of the hot air at the outlet.
Therefore, if there is an obstacle in front of the air outlet, the average temperature of the hot air at the air outlet flows out from the opening to the temperature sensor, so that a high temperature can be detected in a short time. In addition, it is possible to reduce the adverse effect of the warm air heat on the main body case and the intake port.

Further, as shown in FIG. 2, since the air gap is provided on the side of the heating element 8 facing the temperature sensor 12, the amount of heat transmitted from the heating element 8 to the temperature sensor 12 is greatly reduced, and the temperature is reduced. This suppresses a rise in the ambient temperature of the sensor 12 and keeps the sensitivity of the temperature sensor 12 good.

[0016]

As described above, according to the present invention, the opening is provided on the upper surface of the hot air duct on the downstream side of the heating element, and the heating element does not pass through the wall of the hot air duct having the opening. Since the air gap is provided, the sensitivity is improved by suppressing the ambient temperature of the temperature sensor in the vicinity of the opening, and the decrease in the calorific value of the heating element is slightly suppressed, so that the heating performance does not decrease. The temperature change when there is an obstacle can be detected by the temperature sensor in a short time, preventing the thermal deformation of the resin main body case and the intake port, and improving the safety. It is possible to realize an excellent electric hot air blower.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of an electric hot air blower according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the main part.

FIG. 3 is a longitudinal sectional view of a conventional electric hot air blower.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body case 4 Motor 5 Fan 6 Spiral casing 7 Blower 8 Heating element 9 Hot air outlet 10 Hot air duct 11 Opening 12 Temperature sensor 13 Air gap

Claims (1)

(57) [Scope of request for utility model registration] 1. A blower comprising a fan, a motor and a casing housed in a main body case, a hot air duct communicating from a discharge port of the blower to a hot air outlet opening on a front surface of the main body case, a heating element which is apparatus is provided a gap on one side of the inner wall surface located at the air outlet near the warm air duct, and the opening on the downstream extension plane of the gap side wall surface, the opening And a temperature sensor provided on the negative pressure side of the blower near the unit.