JPS6317349A - Hot air type heater - Google Patents

Abstract

PURPOSE:To prevent the overheat of a heating element part due to the trouble in the parts of a heater or a motor by a method wherein a safety switch placed at the opposite side of a heater is installed on the windward side of an air stream guided by a guide part from the center in the longitudinal direction of a heater. CONSTITUTION:A safety switch 8 is in contact with the part of a reflecting plate 1 facing a rod-shaped heater 4 in the space between the plate 1 and a base plate 11 and installed on the windward side of an air stream generated at a guide part 17. The insertion of a plug 14 for an appliance into a heating element part 18 allows electricity to flow and a fan 7 is driven and air is sucked in from the neighborhood of the center of an outer wire screen 5 installed at the lower part of the part 18 to prevent inner damages. An air stream which passes through the suction holes of a motor fixing plate 3 and the space between the plate 3 and a cover 2 for the heating element and then through the space between the cover 2 and the plate 1 via the fan 7 and an air stream which flows in the same direction as the rotating direction of the fan after a part of an air stream is guided by the part 17 are generated and an air stream (b) guided along the longitudinal direction of the heater 4 and an air stream (a) flowing in the tangential direction to the fan 7 are generated. The installation of the switch 8 on the windward side of the air stream (b) enables the switch to be operated more safely and fire etc. can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is useful for blowing out warm air by applying air generated by a fan to a heater, such as in an electric tower kotatsu, and also installing a safety device to prevent the heater from overheating. This relates to the hot air heater installed.

BACKGROUND OF THE INVENTION It has been desired to make electric tower kotatsu as thin as possible in order to increase the space inside the kotatsu. In order to achieve this thinness, the diameter of the heater was reduced.1 The structure of the heating element was designed to minimize the dimensions between the reflector and the heater, and between the heater and the protective guard. In order to prevent this from happening, a fan is provided inside the heating element, and the fan forcibly releases the hot air inside the heating element to the outside of the heating element.

Then, the fan stops rotating, or one of the multiple heaters connected in parallel stops generating heat due to a disconnection, etc.
A safety device was installed inside the heating element as a safety measure in case other heaters overheated abnormally.

For example, as shown in Japanese Utility Model Application Publication No. 57-195053, a safety device such as a temperature fuse was provided on a reflector at a position facing the heater on the leeward side of the fan.

Problems to be Solved by the Invention However, in the configuration in which the safety device is provided on the reflector plate facing the heater as described above, the fan rotates and forces the hot air generated from the heater to the outside of the heating element. Even in normal use, when the safety device emits heat, the temperature of the heater detected by the safety device is high because the safety device faces the heater. Therefore, if the heater overheats abnormally or the fan stops rotating and the heating element overheats, the operating temperature at which the safety device operates is set high to prevent the safety device from malfunctioning during normal use. . However, if the operating temperature of the safety device is raised, there are problems such as abnormal overheating of the heater, or even if the fan stops rotating and the inside of the heating element overheats, the safety device will not operate immediately, creating a risk of fire. .

The present invention solves the above-mentioned problems, and provides a safer hot-air heater by preventing overheating of the heating element due to component failure of the heater or motor.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention has the following features: It is composed of a reflector provided opposite to the heater, a guide section that guides the air flow in the longitudinal direction of the heater, and a safety device provided opposite to the heater. It is arranged on the windward side of the air flow guided by the guide part from the center in the longitudinal direction, so as to ensure safety.

Function: With this configuration, even in the event of a component failure, the safety device is placed opposite each rod-shaped heater, so the sensitivity of the safety device will not be degraded, and furthermore, the safety device can be used in relatively low temperature areas. Since the safety device is placed on the windward side of the air flow guided by the guide section from the longitudinal center of the rod-shaped heater, the operating temperature of the safety device can be maintained even if it is installed in a position facing the rod-shaped heater. Settings can be made and the reliability of the safety device under normal product usage conditions can be improved.

EXAMPLE A hot air type kotatsu according to an example of the present invention will be described below with reference to the accompanying drawings. In FIG. 3, the main body of the tower consists of a wooden frame 12, a wooden board 11 placed in the center thereof,
It is composed of four wooden legs 13 that receive the frame 12. A heating element section 18 that generates hot air is provided below the substrate 11.

FIG. 1 is a partially cutaway plan view of the heating element section 18, and FIG. 2 is a sectional front view of the main part of the heating element section. The configuration will be explained below using these figures. Beneath the reflector 1 disposed below the substrate 1 is a motor fixing plate 3 on which a drive motor 6 made of aluminum 77 is disposed, and rod-shaped heaters are positioned on both outsides of the motor fixing plate 3. 4, and the rod-shaped heater 4
A U-shaped heating element cover 2 is provided on the side facing the reflector 1 across the reflector 1, and a guide 16 is provided along the rod-shaped heater 4 and located between the rod-shaped heater 4 and the motor 6. The heating element cover 2 and the guide 16 form a guide portion 17 that generates an air flow along the longitudinal direction of the rod-shaped heater 4. The safety device 8 is in contact with the part of the reflector 1 facing the rod-shaped heater 4 in the space between the reflector 1 and the substrate 11, and is arranged on the windward side of the air flow generated in the guide part 17. There is. Next, the operation will be explained. Heating element part 1
When the appliance plug 14 is inserted into the fan 7, it is energized and the fan 7 is turned on.
is driven. As a result, air is sucked in from the vicinity of the center of the external wire mesh 5 provided below the heating element part 18 to prevent damage to the inside of the heating element part 18 from external forces, and through the suction hole of the motor fixing plate 3 and the motor fixing plate 3, which generates heat. The airflow that passes between the heat generating body cover 2 and the reflector plate 1 via the fan 7 and the air flow that passes between the heat generating body cover 2 and the reflecting plate 1 through the heat generating body cover 2 and the guide portion 17 consisting of the heat generating body cover 2 and the guide 16 are combined. When the fan 7 is guided, an air flow is generated in the same direction as the fan rotation direction, and when the air is guided along the longitudinal direction of the rod-shaped heater 4, an air flow a flowing in the tangential direction of the fan 7 is generated.

The important part of the present invention is that the airflow generated via the fan 7 is heated by the rod-shaped heater 4 and turned into warm air, and that at least the directionality of the air flow allows the space between the rod-shaped heaters 4 in the longitudinal direction to be This is because a temperature difference occurs. Here, the temperature difference occurring in the reflecting plate 1 facing the rod-shaped heater 4 will be explained using FIG. 1, FIG. 4, and FIG. 6. In FIG. 1, a reflector 1 facing a rod-shaped heater 4
As for the position of the safety device disposed in contact with the space side of the reflector 1 and the substrate 11, the windward side of the air flow when the fan rotates is designated as part A, and the leeward side is designated as part B. In FIG. 6, the length of the rod-shaped heater is l, and the zero point is from the windward side on the back surface of the reflector facing the rod-shaped heater 4.

When 1/21 points and 1 points are taken, the 0 point indicates the A section, the j point indicates the B section, and the //21 point indicates the middle upper part in the longitudinal direction of the rod-shaped heater 4. In the figure, a temperature characteristic 23 showing the temperature distribution in the part of the reflector facing the heater when the fan 7 rotates.
A temperature characteristic 24 showing the temperature distribution at the portion of the reflector 1 facing the heater when the fan is stopped is depicted. When the fan is stopped, if the 0 point is 11℃, the //2I! point is the peak value 22℃, and the j point is
The temperature is 11°C, which is the same as the 0 point. Also, when the fan is rotating, it is 0.
If the point is T1°C, the temperature increases as it approaches the 1st point, and at the 1st point it becomes T2. Therefore, the most preferable setting position for safety device 8 in terms of temperature is low in normal use and high in abnormal conditions. 7/ from the point! 1
It can be seen that up to the point is appropriate as the placement position. Next, FIG. 4 is a temperature characteristic diagram showing the time-temperature relationship in parts A and B when a normal temperature test during fan rotation according to the Electrical Appliance and Material Control Law was conducted. The difference between the peak value of temperature characteristic B in part A and the peak value of temperature characteristic 21 in part B is about 20°C (T2-T1). Here, for example, B
Assuming that the operating temperature margin for the safety device is approximately 15°C from the peak value of oil temperature characteristics 21, the margin of approximately 16°C under normal conditions may be lost until the safety device operates due to external factors such as voltage fluctuations. , there is a risk that the safety device 8 may malfunction and stop the power supply to the rod-shaped heater 4. However, by arranging the safety device 8 in the A section, a margin of about 35° C. can be provided, so that the reliability of the safety device 8 can be improved. It goes without saying that the operating temperature setting of the safety device 8 for distinguishing between an abnormal usage state and a normal usage state can be arbitrarily set depending on the difference in structure. therefore,
By arranging the safety device 8 facing each rod-shaped heater 4 and on the windward side of the air flowing from the longitudinal center of the rod-shaped heater 4, the heat of each rod-shaped heater 4 can be easily sensed. Part of the wire was disconnected, and 77-7 stopped, etc. (f
C, the safety device can be operated more safely before each part of the product reaches an abnormal temperature, and fires can be prevented.

Needless to say, although the position of the safety device 8 has been explained on the back side of the reflector plate 1, the same effect can be obtained even if it is provided in a position where the safety device 8 is placed in the flow of air or in a position where heat is taken away by the flow of air, for example, in the guide portion 17 or the like.

Effects of the Invention As described above, the heating element of the present invention includes a heating element (rotated by a motor), a rod-shaped heater provided on the leeward side of the air flow generated by the fan, and a rod-shaped heater provided opposite to the heater. a guide section for guiding the air flow in the longitudinal direction of the heater; and a safety device provided opposite to the heater; By disposing the safety device on the windward side of the air flow guided by the guide portion, the operating temperature setting position of the safety device can be properly set, improving the reliability of the safety device and stabilizing the quality of the product. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view showing the heating element of a hot air heater according to an embodiment of the present invention, FIG. 2 is a sectional front view of the main parts of the heating element of the hot air heater, and FIG. 3 4 is a temperature characteristic diagram showing the time-temperature relationship of the heating element of the hot air heater, and Figure 5 is the heating element of the hot air heater. FIG. 3 is a temperature characteristic diagram showing the temperature distribution of a rod-shaped heater in FIG. 1...Reflector plate, 2...Heating element cover,
3...Motor fixing plate, 4...Rod heater, 5...External wire mesh, 6...Motor, 7
...Fan, 8...Safety device, 9...
... Part A, 10 ... Part B, 11 ... Board, 16 ... Guide guide, 17 ... Guide section, 18 ... Heating element part, 21... Part A 1 Visibility characteristics, 22... Part B temperature characteristics 0 Name of agent Patent attorney Toshio Nakao and 1 other person t-
--ti@I 2--12 outside 4r,'- 3-1-motor round oj mutual 8-4 included 1 nakamisaki ν

Claims (2)

[Claims] (1) The heating element section includes a fan rotated by a motor, a rod-shaped heater provided on the leeward side of the airflow generated by the fan, a reflector provided opposite to the rod-shaped heater, and the airflow. The safety device includes a guide portion that guides the rod-shaped heater in the longitudinal direction of the rod-shaped heater, and a safety device provided opposite to the rod-shaped heater. A hot air heater characterized by being placed on the windward side of the air flow. (2) The hot air heater according to claim 1, wherein the safety device is provided on the back surface of the reflector at a position facing the rod-shaped heater.