JPH04369325A - Thin panel heater using ptc ceramic element - Google Patents

Abstract

PURPOSE:To provide a panel heater wherein heat production is stabilized, and uneven temperature is unlikely to be caused, and further there is higher the degree of positional freedom of striking any fixing tool such as a nail into a floor and the like, by accommodating and disposing parts such as a heater and conductor wires in a concave portion of a pedestal and covering the upper surface of the pedestal with a heat radiation plate. CONSTITUTION:A pedestal 1 is formed by sticking two plywoods 2, 3 such as veneer plates, and the lower plywood 2 is employed as a substrate and in the upper plywood 3 cutout plates 3a, 3b, 3c are provided which plates 3a, 3b, 3c serve to accommodate parts such as a plurality of band-shaped heaters 4 and a conductor wire 5. A band-shaped heater 5, a conductor wire 5, and a temperature fuse 6 are accommodated and wired in the cutout plates 3a, 3b, 3c. Thereafter, a heat radiation plate 7 is covered from the upper portion and bonded to form a panel heater. Further, a plug 8 to which a power supply plug receptacle is inserted. The band shaped heater 4 is formed by arranging a plurality of PTC ceramic elements between upper and lower electrode plates at an equal space, and joinning them with the electrode plates.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin panel heater that can be used for general heating, floor heating, etc.

0002

[Prior Art] Panel heaters are characterized by their thinness, so they are used for general heating, floor heating, etc., but as a heating element, they have a self-temperature control function for safety reasons. PTC (positive characteristic thermistor) heaters are often used.

Among these, the PTC heater used for floor heating has conventionally been a planar heater made of a heat-resistant and insulating organic material mixed with a conductive material such as carbon particles.

0004

However, such conventional planar heaters have the following problems. 1) When the temperature changes, the contact state between the conductive material particles in the organic material changes, and there is no guarantee that the original contact state will return even if the temperature returns, so the stability of heat generation is lacking, especially after long-term use. change over time cannot be avoided. 2) Due to the above, the contact state of the conductive material particles tends to vary, and as a result, the electrical resistance varies depending on the location, which tends to cause temperature unevenness. 3) Since the heating element is located almost in front of the panel heater, the positions for nailing to fix it to the floor are very limited from the standpoint of safety, making installation difficult.

[0005] The problem to be solved by the present invention is to provide a panel heater that generates heat stably, is less likely to cause temperature unevenness, and has a high degree of freedom in the positioning of fixing devices such as nails on the floor. The purpose is to shorten the time required for inrush current to the panel heater from when the power is turned on.

[0006]

[Means for Solving the Problems] In order to solve this problem, a thin panel heater using a PTC ceramic element of the present invention has a base having a recess formed on the upper surface for accommodating a heating element, a conducting wire, etc. The pedestal is characterized by comprising a plurality of heating elements such as ceramic heaters and parts such as conductive wires housed and arranged in the recessed portion of the pedestal, and a heat sink covering the upper surface of the pedestal.

In this configuration, a plurality of PTC ceramic elements bonded between the upper and lower electrode plates are divided into a plurality of groups, and a heating element is used in which the PTC ceramic elements belonging to one group are brought thermally close to each other. Can be done.

[0008]

[Operation] In the present invention, a PTC ceramic heater, for example, barium titanate (BaTiO3) is used as a heating element.
) is used. Barium titanate is a semiconductor ceramic having positive resistance-temperature characteristics, and when this sintered body is heated with electricity, its electrical resistance increases rapidly by more than 10,000 times at a temperature above the Curie point. Therefore, it becomes an insulator, and no electricity will flow even if it is energized any further, and as a result, the temperature of the sintered body remains constant at a certain temperature, slightly higher than the Curie point. It is well known that this Curie point can be freely selected by adding lead or strontium elements.

[0009] This PTC ceramic element has the excellent safety of self-temperature control function and the energy-saving effect of self-output control function. It is used as a heating element, and its stability and durability have been proven. For this reason, the PTC ceramic element can be said to be the most suitable heating element for panel heaters for floor heating for general households.

[0010] It is preferable to use a plurality of small blocks of PTC ceramic elements constituting the heating element for manufacturing reasons and for ease of temperature control. In that case, the general idea is to arrange the PTC ceramic elements at equal intervals with predetermined intervals. In such a case, the heat generated in each PTC ceramic element is absorbed by the electrode plate, which has a large area, so that it takes a long time to reach the Curie point. Therefore, many PTs
A heat generating device using a C element has the disadvantage that when the power is turned on, a current having a value larger than the current flowing in a steady state, that is, an inrush current flows for a long time. As a solution to this problem, the PTC ceramic elements are not arranged at regular intervals, but are arranged in groups, and within the group, the PTC ceramic elements are placed close together to speed up the rate of temperature rise between the elements, and turn on the power. It is possible to shorten the inrush current time from when the temperature reaches a steady state.

[0011]

EXAMPLES The present invention will be specifically explained below based on examples. FIG. 1 is an exploded perspective view showing an embodiment of the present invention, and 1 is a pedestal. In this example, the pedestal 1 is formed by pasting together two plywood sheets 2 and 3 such as plywood boards, the lower plywood 2 is used as a substrate, and the upper plywood 3 has a plurality of (two in this example)
A notch 3a for storing parts such as a band-shaped heating element and conductive wires.
, 3b, and 3c are provided. These notches 3a, 3b
, 3c, the band-shaped heating element 4, the conductive wire 5, and the thermal fuse 6 are housed and wired, respectively. Thereafter, a heat dissipation plate 7 such as an aluminum plate is placed on top and bonded to form a panel heater. Note that 8 is a plug that is inserted into a power outlet.

FIG. 2 is a perspective view showing each example of the band-shaped heating element 4. (a) shows an example in which a plurality of PTC ceramic elements 11 are arranged between upper and lower electrode plates 12 and 13 with equal spaces 14 therebetween, and are bonded to the electrode plates 12 and 13. (b) shows an example in which a plurality of PTC ceramic elements 11 are divided into three or more groups, and the PTC ceramic elements 11 in each group are arranged close to each other. (c) is an extreme example,
An example is shown in which the PTC ceramic elements 11 are divided into two groups and arranged close to each other on both sides.

FIG. 3 shows the change in current when a rated voltage is applied to the panel heater having the PTC ceramic element 11 arranged in this manner. As you can see from this figure, Figure 2
When the PTC ceramic elements are arranged at regular intervals as shown in (a), it takes more than 300 seconds for the initial current to increase from 3 to 4 A to 2 A. In the example of b), this time is shortened to about 60 seconds, and in the example of dividing the time into two as shown in FIG. 2(c), it is shortened to about 40 seconds. The reason for this is that the thermal conductivity of the PTC ceramic element is low, so if the element configuration is as shown in Figures 2(b) and (c), the generated heat will be difficult to diffuse, and the temperature of the element will rise quickly. , the PTC element reaches the Curie point quickly, and the inrush current time becomes shorter.

However, in the example of FIG. 2(c), although the time during which the inrush current flows is shortened, it is difficult to obtain uniformity in temperature distribution. The number of groups is determined by considering the following.

[0015]

[Effects of the Invention] As described above, the present invention provides the following effects.

(1) Since a PTC ceramic element is used as a heating element, the stability of heat generation is improved, and a panel heater that is safe and has a long life can be provided.

(2) Since plywood is used for the pedestal, a panel heater that is easy to process and inexpensive can be provided.

(3) Since the heating element is embedded between the plywood, the load of the floor is not applied to the heating element, and even heavy objects can be supported.

(4) Since it is embedded in plywood, it has excellent heat retention and insulation properties.

(5) Nails can be driven into most parts of the panel heater, making the work of fixing the panel heater to the floor much easier.

(6) By arranging the plurality of PTC ceramic elements constituting the heating element in groups, the inrush current time can be shortened, so even when using a large number of panel heaters, A predetermined temperature can be quickly reached without tripping the breaker.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the configuration of an embodiment of a panel heater of the present invention.

FIG. 2 is a perspective view showing various configuration examples of a band-shaped heating element.

3 is a graph showing changes in current of heating elements in each arrangement of FIG. 2. FIG.

[Explanation of symbols]

1 Pedestal, 2, 3 Plywood, 3a, 3b, 3c Notch, 4 Band-shaped heating element, 5 Conductive wire, 6 Temperature fuse, 7 Heat sink, 8 Plug, 11 PTC ceramic element, 12, 13 Electrode plate, 14 Space

Claims (2)

[Claims] 1. A pedestal having a recess formed in its upper surface for accommodating a heating element, a conductive wire, etc., a plurality of parts such as a plurality of heating elements and conductive wires stored and arranged in the recess of the pedestal, and the pedestal. A thin panel heater using a PTC ceramic element and equipped with a heat sink that covers the top surface of the heater. [Claim 2] A plurality of PTC ceramic elements joined along the longitudinal direction between upper and lower electrode plates are divided into a plurality of groups, and the PTC ceramic elements belonging to one group are brought thermally close to each other to generate heat. A thin panel heater using the PTC ceramic element according to claim 1.