JPH0744819U - Panel heater - Google Patents

Abstract

(57) [Summary] [Purpose] Even if a carbon fiber mixed paper heating element is used, it does not run out of temperature due to the decrease in resistance value due to heat generation, and is practical as a panel heater, and is lightweight and thin. By utilizing the above, a portable panel heater is provided, and a stand is provided so that this panel heater can be stably erected, and a practical panel heater is provided. [Structure] A carbon fiber-mixed paper sheet prepared by mixing carbon fibers, bast fibers, and a viscous agent, and at least a part of the carbon fibers covered with a viscous agent solid content is embedded in a resin, and electrodes are attached. The heat generating element 2 is formed, and the frame elements 3 and 4 are formed in an arbitrary shape by sandwiching both sides of the heat generating element. A panel heater is configured by fixing the panel heater on the upper surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a panel heater having a stand for standing a thin panel heater formed by using a carbon fiber mixed paper.

[0002]

[Prior art]

 Various types of indoor heating appliances have been used in the past, but in recent years far infrared rays, which have long wavelengths, provide a soft heating effect that is less irritating to the human body, and can penetrate clothing. Radiant heating from a low-temperature heating element, which has a large heating effect, is drawing attention.

Various types of radiant heating appliances using low-temperature heating elements have been developed. In addition to embedding a heating element in a wall surface or floor surface, a panel heater is installed on the floor surface as a wall-mounting type or a portable type. There is.

On the other hand, various heat sources are used as the low-temperature heating element, and research and development have been carried out to heat a solid having a high heat capacity such as a heat storage material with a nichrome wire or a heat sink. Those that heat the non-flammable oil have already been developed. It is also considered to use the conductivity and exothermicity of carbon fiber as a heat source for radiant heating. This carbon fiber is mixed with papermaking pulp to make paper, and an electrode is laid on this paper to conduct electricity. This is being researched and developed.

[0005]

[Problems to be solved by the device]

 When a heating element containing carbon fiber obtained by mixing the above-mentioned carbon fiber with papermaking pulp is energized, when the heating element is energized, the electrical resistance of the carbon fiber significantly decreases with the temperature rise due to energization heat generation, and an excessive current flows. However, the calorific value increases synergistically and eventually reaches an uncontrollable high temperature. Moreover, the carbon fibers in the heating element must be shortened in order to distribute them as evenly as possible over the entire surface.However, if the fibers are shortened, the amount of heat generated will decrease, making them unsuitable for practical use. Then, while sufficient calorific value is obtained, the carbon fibers are not evenly distributed over the entire surface, causing unevenness. Therefore, there are high temperature parts and low temperature parts on the surface of the heating element, and even if the thermostat is used to prevent the abnormal temperature rise of the heating element as described above, it is economical to place many thermostats on the entire surface. However, it is not practical in terms of wiring and wiring.

Further, when a heating element made of carbon fiber mixed paper is made thermostatically controllable, and a current is conducted by sandwiching it between synthetic resin layers in order to put the heating element into practical use as a panel heater, heat generation that tends to rise as described above. Since the body is turned on and off frequently with a thermostat, the temperature of the heating element changes drastically, and the synthetic resin sandwiching the heating element rapidly deteriorates due to repeated thermal expansion and contraction. I can't. Attempts have also been made to improve the strength by mixing glass fibers into this synthetic resin, but glass fibers also gradually shred when the temperature change is repeated for a long period of time, and become brittle with the synthetic resin.

Since the conventional heating element made of carbon fiber mixed paper has many drawbacks as described above, its application range is extremely limited. For example, a hem is attached to a wall surface and a large number of thermostats are arranged on the back surface. Also, an opaque cover is provided on the surface so that it cannot be seen from the outside even if resin cracks. Also, since it is a wall-embedded type, a large force does not act from the outside, and even if resin cracks, it will function as a heating element. It was limited to the extent that it could maintain the function of. Therefore, the conventional carbon fiber mixed paper heating element cannot fully utilize the features of this heating element that are light, thin, and easy to handle, and the above-mentioned features can be utilized most. As a portable panel heater, it was not possible to stand up close to the user and obtain effective heating using far infrared rays.

Therefore, according to the present invention, even if a carbon fiber mixed paper heating element is used, it does not run out of temperature due to resistance decrease due to heat generation, has practical utility as a panel heater, and is lightweight and thin. Taking advantage of the above, a portable panel heater is provided, and a stand is provided so that this panel heater can be stably erected, and a practical panel heater is provided.

[0009]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention uses a carbon fiber-blended sheet prepared by mixing carbon fiber, bast fiber and a viscous agent, wherein at least a part of the carbon fiber is covered with a viscous agent solid content. It has a frame plate that is embedded in the inside of it to form a heating element by attaching electrodes, and has a frame plate that is formed in an arbitrary shape by sandwiching both sides of the heating element. The panel heater is constructed by fixing the side spacers on the base.

[0010]

[Work]

 Since the present invention is configured as described above, when the viscous solid component covering the surface of the carbon fibers is energized to the carbon fibers, direct contact between the carbon fibers is prevented, and the carbon fibers are prevented from contacting each other. There is no change in contact resistance due to temperature rise at the contact area, stable heat generation is achieved, deterioration due to thermal fluctuations of the surrounding resin is prevented, and it is assumed that this is a practical heating element for panel heaters. Both sides are sandwiched by frame plates to form an arbitrary shape and are held in an optimal shape according to the usage condition. By providing a spacer in the outer circumferential gap between these two frame plates, the The stress on the heating element due to the deformation of the shape is reduced and the appearance is improved, and the lower end side spacer is fixed on the base to hold the heating element upright on the base with a simple structure.

[0011]

【Example】

 An embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, the entire structure of the panel heater 1 is such that the surface of the heating element 2 is exposed on the front side, and both sides of the heating element 2 are sandwiched by a front frame plate 3 and a rear frame plate 4. It is rare. Both frame plates are formed in parallel and curved in a concave shape toward the front, both side parts 5 are bent backward, and the upper end member 7 is placed in the upper end gap of both frame plates and the lower end part is placed in the lower end gap. By mounting the lower end member 8 and fixing the lower end member 8 on the base 9, the panel heater 1 is vertically held.

The heating element 2 is made by cutting carbon fiber made of rayon or polyacrylonitrile as raw material, and as bast fiber such as Kozo, Mitsumata and Manila hemp as Japanese paper pulp, and polyacrylamide, polyethylene oxide, carboxymethyl cellulose and the like. A heating element is used as a carbon fiber-blended sheet by mixing a synthetic viscous agent or a natural viscous agent such as totorooi and making it into a paper. In the heat-generating sheet thus produced, at least a part of the inner carbon fibers is covered with the solid adhesive content, and a portion in which the solid solid content is present is present at the contact portion between the carbon fibers. There is no change in contact resistance due to temperature rise in the contact area between carbon fibers, and stable heat generation is possible.

In the production of this heating element, as an example, 0.5% by weight of carbon fiber (6 mm length, 6 μ diameter) starting from rayon and pulp 99. Water is added to 5% by weight and stirred well to disperse the carbon fibers in the pulp well. Then, 630 cc of polyacrylamide is added and further stirred, and then the paper material is poured onto a paper making net having a width of about 1 m to make a paper having a basis weight of 40 g / m ² . The thickness of the formed paper after passing through the drying drum was 80 μm. The electrical resistance of this mixed paper was 50 Ω / □, and the tensile strength was 4.0 kg / 15 mm in the longitudinal direction (paper feeding direction) and 3.5 kg / 15 mm in the lateral direction (right angle to the feeding direction). In the dry papermaking, the carbon fiber is 3% of the total weight of the papermaking.

In the above formulation, the mixed paper obtained by substituting the same amount of Manila hemp for Mitsumata also had almost the same properties. When Mitsumata was replaced with Kozo, the same properties were obtained, except that the paper strength was slightly increased.

A carbon fiber cut into a fixed size of 3 mm or less did not have a required calorific value because the mixed sheet had insufficient conductivity. On the contrary, carbon fibers cut to a size of 15 mm or more, for example 20 mm, are not well dispersed in the pulp, resulting in carbon fiber unevenness in the mixed paper, unstable temperature characteristics, and excessive heating. Was given. In addition, for example, even if 10 mm of carbon fiber is mixed so as to be 15% of the sheet weight, it is recognized that if the basis weight is 80 g / m ² and the thickness is 200 μm, the temperature curve exceeds the set value and control becomes difficult. It was

Next, FIG. 4 is a plan view showing an embodiment of a practical surface heating element of the present invention manufactured from the carbon fiber mixed paper sheet manufactured as described above. This surface heating element 10 was obtained by cutting a mixed paper sheet (40 g / m ² , 80 μ thick) 11 into a size of width W = 900 mm and length L = 1800 mm, and a width of about 10 mm along the long side (L). A pair of electrodes 12 is provided so that each electrode 12 can be appropriately connected to a power source (DC or AC) via a lead wire 13 and a plug 14. The surface heating element 10 is set so that a voltage of 100 V is applied between the electrodes, a current of about 4 A (or less) is applied, and a surface temperature of less than 50 ° C. is stably maintained for a long time. .

The electrode 12 can be formed by various methods, but it is practical that the silver paste is preferably attached by screen printing along the sides of the mixed paper sheet 11. FIG. 5 is an enlarged partial cross-sectional view showing the electrode portion thus formed, in which the silver paste 15 forming the electrode 12 has penetrated to about half the paper thickness T (= 80 μm). Preferably, a copper foil 16 is adhered to a surface of the silver paste electrode 12 at a key portion, and a lead wire 13 is welded thereto.

The results of the energization heat generation test for the above surface heating element 10 are shown in the graph of FIG. The graph A in FIG. 6 represents the temperature (C) measured at intervals of 30 minutes at the central point A (FIG. 4) on the surface of the surface heating element 10. A voltage of 100 V was applied between the electrodes 12 and 12, and measurement was performed at room temperature of 20 ° C. for 14 hours. As can be seen from Graph A, the temperature rises rapidly to 40 ° C in about 10 minutes after energization, and after 30 minutes, the temperature rises gradually, becoming almost stable in 1 hour and never exceeding 50 ° C even after several hours. . The graph of the temperature value measured on the point A ′ (FIG. 4) at the end of the surface heating element 10 almost overlaps with the graph A, and there is no great difference. Including the other tests, it was confirmed that the surface heating element 10 had a substantially uniform temperature distribution at each point on its surface.

The graph B in FIG. 6 shows the temperature (° C.) measured under the same condition at 30 minutes intervals at the point A (FIG. 4) at the center of the surface of the product as the panel heater. . Graph B also behaves similarly to graph A.

A broken line graph C in FIG. 6 is a graph of the temperature measured at the point C (FIG. 4) on the electrode 12. The temperature graphs measured at the opposite ends and the center of the electrode also overlap with Graph C. The temperature of the electrode is stable at a level of about 35 ° C., and it is considered that this is due to the heat generated by the surface-heated mixed sheet 11 rather than the heat generated by the electrode itself.

Graph D in FIG. 6 is an actual measurement value of the current flowing between the electrodes 12 and 12, which is almost stable on the line of 3.8 to 4 A, contrary to the conventional technical common sense, and carbon fiber mixed paper. It has been demonstrated that the electrical resistance of the material does not change with temperature and time. In this way, it was completely unpredictable in the conventional common sense that conventional large-scale carbon fiber mixed sheet, which corresponds to one tatami mat, maintains stable heat generation without runaway for a long time exceeding 10 hours. That is.

For comparison, a mixed paper made without the use of a sticking agent and prepared with a blending ratio of normal sulfite pulp and carbon fiber was tested under the same conditions (100 V, 20 ° C. room temperature). A chain line graph X in FIG. 6 shows this result, but the temperature exceeded 50 ° C. in about 30 minutes after energization, and thereafter, the temperature continued to rise and showed no tendency to stabilize. Such a heat generating sheet has not been practically used as a surface heating element even if the on / off control is performed by a thermostat or the like.

The carbon fiber mixed papermaking heat generating sheet as described above is further subjected to the following processing so that it can be installed upright as a panel heater. That is, as shown in FIG. 7, the carbon fiber mixed sheet 22 obtained as described above is introduced from the raw material carrying-in end 21 of the vacuum chamber 20 into the central part thereof, and the glass fiber A resin prepreg 23 in which a semi-cured epoxy resin is impregnated at a low temperature state is continuously introduced into the fiber fabric.

In the vacuum chamber 20, rollers 24, 24 heated to about 180 ° C. are rotatably provided so as to face each other while maintaining an appropriate pressing force. Therefore, the material introduced from the material carrying-in end 21 of the vacuum chamber 20 is integrally pressed in a heated state, and the semi-cured epoxy resin enters from both sides of the carbon fiber mixed sheet 22 and is thermally cured. As a result, the heating element 2 that is wholly integrated is molded. When the molded heating element 2 is carried out of the vacuum chamber 20 and left to cool outside, as shown in the cross section of FIG. 8, there is a carbon fiber mixed sheet 22 in the center and epoxy resin layers on both sides. The heating element 2 is formed. If necessary, as shown in the same figure, a flocking cloth 24 'having an appropriate color, pattern and texture is attached to enhance the design effect, improve the feel of the skin, diffuse the radiant heat and further soften. You may make it obtain a heating effect.

When energizing the heat generating sheet, as shown in FIG. 9, when the two electrodes 12 provided on the heat generating sheet 22 as described above and the power cord 25 are connected, the heat generating sheet 22 is omitted. By connecting via the thermostat 26 provided in the central portion, the energization can be temporarily cut off in case the temperature of the heat generating sheet rises. As described above, the thermostat 26 performs on / off control so as to keep a constant temperature as a measure against the temperature runaway of the conventional carbon fiber mixed paper sheet like the conventionally used thermostat. Not the one.

As described above, the heating element 2 obtained as described above is sandwiched between the front frame plate 3 and the rear frame plate 4, and the front frame plate 3 and the rear frame plate 4 are sandwiched between them. Both are made of metal plate and have the same shape by being pressed by the same mold. Therefore, the front frame plate 3 and the rear frame plate 4 are arranged in parallel.

The front frame plate 3 has an opening 30 for exposing the heating element 2 in the center thereof, and the two frame plates 3 and 4 arranged in parallel as described above face the front at the center thereof. The heating element 2 sandwiched between the frame plates is also bent into the same shape due to its elasticity. When the synthetic resin layer covering the heating element 2 is made thicker and the heating element 2 becomes thicker and it is difficult to bend due to its elasticity, in the molding step of the heating element described above, before the semi-cured resin is completely cured, It is also possible to cure in a mold having a concave shape to form the predetermined concave shape.

As shown in FIG. 3 (b), the two frame plates 3 and 4 that sandwich the heating element 2 are fixed with an adhesive or the like with the rubber pieces 31 sandwiched between them as shown in FIG. Maintain the horizontal arrangement of both frame plates 3 and 4 and adjust the appearance of the ends. Both side portions 5 of both frame plates 3 and 4 are bent rearward, and are self-supporting in combination with the shape of the central recess. The degree of bending and the length of the side portions 5 can be set arbitrarily.

As shown in FIG. 3A, an upper end member 7 and a lower end member 8 made of an elastic member such as rubber are provided in the upper and lower gaps of the frame plates 3 and 4 arranged and fixed in parallel as described above. It is fitted. The upper end member 7 is composed of a fitting portion 34 that fits into the gap between the frame plates 3 and 4, and a lid portion 35 whose lower end abuts on the upper ends of the frame plates 3 and 4. A screw through hole 36 is formed therethrough, and a circular groove 37 into which a screw head is fitted is provided on the surface of the lid 35. Further, a screw hole 38 is provided at a position corresponding to the screw through hole 36 on the upper end surface of the heating element 2 which is solidified with a synthetic resin, and the screw is screwed through the screw through hole 36 from above the lid portion 35. The upper end member is integrated with the heating element 2 by screwing it into the hole 38, and the upper end portions of both the frame plates 3 and 4 are integrated with the fitting portions 34 while maintaining a stable distance therebetween.

Like the upper end member 7, the lower end member 8 also includes a fitting portion 40 that fits into the gap between the frame plates 3 and 4, and a lid portion 41 whose upper end abuts the lower ends of the frame plates 3 and 4, A screw hole 42 penetrating the lower end member 8 from the lid 41 is provided at an appropriate position thereof. On the other hand, as shown in FIG. 3 (a), the base 9 supporting the erected heater portion is formed into a trapezoid by pressing a metal plate, and the upper end supporting surface 43 thereof has the lower end member of the above lower end member. A screw through hole 44 is provided at a position corresponding to the screw through hole 42. Further, a screw hole 45 is provided at a position corresponding to the screw through hole 42 on the lower end surface of the heating element 2 which is solidified with a synthetic resin, and the screw holes 45 and 42 are passed through from the lower surface side of the base 9. By screwing into the screw hole 45, the base 43, the lower end member 8 and the heating element 2 are integrated, and the lower ends of both the frame plates 3 and 4 are integrated while the spacing is stably maintained by the fitting portion 40.

As shown in FIG. 2, the power cord 46 connected to the lead wire of the heating element 2 is led out from a bush 47 of a through hole provided in the lower part of the rear frame plate 4, and an on-line is provided in the middle thereof. An off switch 48 is provided. Thereby, when the plug 49 is inserted into the outlet and the switch 48 is turned on, the heating element 2 is stably maintained at a predetermined temperature. In addition, in order to adjust the temperature of the heating element 2 to a desired value, a current regulator that is conventionally used for adjusting the temperature of various electric heating elements can be used. It can be attached at any position such as the portion 5.

In the above-described embodiment, the panel heater is formed so as to have a gentle concave shape toward the front surface, but it can be formed into various shapes as shown in FIG. 10, for example. As shown in (a) in the figure, it is bent in a concave direction at the center, or as shown in (b) in a largely concave shape, either at the ticket gates at stations or outdoors. It may have a shape suitable for heating the feet of individuals at the ticket gates of various venues, guards, parking lots, toll gates such as expressways, etc. Also, as shown in Fig. (C), it is curved in a convex direction in the center. Alternatively, the radiant heat may be radiated to a wide area in the room by forming a curved shape in a convex shape in the central portion or in the vicinity thereof as shown in FIGS. In addition, the above-described shape change can be performed in the vertical direction as well, and various modifications can be made, for example, the inside and outside of the spherical surface can be formed.

[0033]

[Effect of device]

 Since the present invention is configured and operates as described above, a carbon fiber mixed heating element is used to prevent a temperature runaway due to a reduction in resistance due to heat generation, and can be made into a practical panel heater. In addition, it is possible to obtain a portable panel heater by taking advantage of the features of the light weight and thin heating element. In addition, by forming the frame plate in any shape, it is possible to adopt the optimum shape that is suitable for the place where the panel heater is used, and the shape is maintained by the deformation of the frame plate that sandwiches the heating element. The spacer is used to maintain the gap between both frame plates and their fixing, and the panel heater can be fixed simply by fixing the lower end side spacer on the base without excessive force being applied to the heating element. It can be stably installed upright and can be made inexpensive with a small number of parts.

[Brief description of drawings]

FIG. 1 is a front perspective view of an embodiment of the present invention.

FIG. 2 is a rear side perspective view of the same.

3A is a vertical sectional view of the same, and FIG. 3B is a horizontal sectional view of the same portion.

FIG. 4 is a plan view of the heating element portion.

FIG. 5 is a cross-sectional view of a connecting portion between the heating element and a lead wire.

FIG. 6 is a graph showing the use time of the heating element and the characteristics of current and temperature.

FIG. 7 is a manufacturing process drawing of the same heat disassembly.

FIG. 8 is a cross-sectional view of the heating element.

FIG. 9 is a diagram showing a wiring example in the same heating element.

FIG. 10 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Panel heater 2 Heating element 3 Front frame 4 Rear frame 5 Side part 7 Upper end member 8 Lower end member 9 Base 10 Heating element 11 Mixed sheet 12 Electrode 13 Lead wire 14 Plug 15 Silver paste 16 Copper foil 20 Vacuum chamber 21 Material carry-in end 22 Carbon fiber mixed paper sheet 23 Resin prepreg 24 Roller 25 Power coat 26 Thermostat 30 Opening 34 Fitting portion 35 Lid portion 36 Screw through hole 37 Circular groove 38 Screw hole 40 Fitting portion 41 Lid portion 42 Screw through hole 43 Top support surface 44 Screw through Hole 45 Screw hole 46 Power cord 47 Bushing 48 Switch 49 Plug

Claims (3)

[Scope of utility model registration request] 1. A carbon fiber-mixed sheet, which is produced by mixing carbon fibers, bast fibers, and a viscous agent, and at least a part of the carbon fibers is covered with a viscous agent solid content, is embedded in a resin, and an electrode is provided. To form a heating element, and to have a frame plate formed in an arbitrary shape by sandwiching both sides of the heating element, providing a spacer in the outer peripheral gap of both frame plates, and fixing the lower end side spacer on the base. Panel heater characterized by. 2. A carbon fiber mixed paper sheet is made of carbon fiber 0.5.
2. The panel heater according to claim 1, wherein the panel heater is composed of wt% and pulp obtained from Mitsumata 99.5 wt%. 3. The panel heater according to claim 1, wherein the carbon fiber mixed paper sheet is obtained by laminating a resin prepreg impregnated with an epoxy resin on a glass fiber woven fabric.