JPH10335052A - Skin current heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a skin current heating device suitable for small-scale use. SOLUTION: A skin current heating device is provided with an electric power adjusting circuit 10 and a skin current heating body 12. The electric power adjusting circuit 10 is provided with a transformer 14 and a selector switch 16, the transformer 14 decreases voltage of a commercial power supply and can take out plural kinds of second voltages from a plurality of selective terminals 28. Applying voltage to the skin current heating body 12 is switched by switching of the selector switch 16 into a plurality of stages, and electricity input is adjusted. In the skin current heating body 12, a plurality of steel pipes are arranged in parallel, a plurality of insulating wires are inserted through each steel pipe, the ends of a plurality of insulating lines inserted through mutually adjacent steel pipes are connected by an independent connecting member, and therefore, all directions of current of the insulating wires inserted through one steel pipe are made same, and a plurality of short insulating wires are connected in series.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin current heating device, and more particularly to a skin current heating device suitable for small-scale use.

[0002]

2. Description of the Related Art A skin current heating apparatus includes a ferromagnetic tube, such as a steel tube, which has an insulated wire passed through it and an AC current from an AC power source, such as a commercial power supply, passed through the insulated wire. A device that generates electric current and generates heat. A ferromagnetic tube is a tube made of a ferromagnetic material such as steel.
A conductive wire whose surface is electrically insulated by an organic insulating material, an inorganic insulating material, or the like. The skin current heating device was initially developed for keeping the pipeline warm, but later it became known
No. 931, Japanese Patent Publication No. Sho 52-14854, etc., heating devices for melting snow and preventing freezing of roads, floors, walls, etc., industrial heat sources such as boilers, hot water supply facilities, plating baths, etc. It has been widely used in consumer heating devices such as panel heaters and heating mats.

However, the skin current heating device is particularly effective when used on a large scale, and the thermal inertia (heat capacity)
It has not been suitable for small-scale use because it has been developed for large-scale equipment with large size. Because the skin current heating device has a simple structure, it is easy to obtain a strong and durable one, and if you pay attention to that point, it is suitable for small-scale use, but the conventional skin current heating device is It cannot be said to be suitable for small-scale use. For example, ON / OFF control is adopted for temperature control, and fine-grained temperature control is impossible. In addition, in order to dispose the ferromagnetic tube and the insulated wire in a relatively narrow place, it is necessary to bend the conductor in a zigzag manner. Was not easy. Furthermore, in recent years, it has been pointed out that electromagnetic waves may have an adverse effect on the human body, but such measures cannot be said to be sufficient.

[0004]

DISCLOSURE OF THE INVENTION Problems to be solved by the invention, means of solution, operation and effects The present invention has been made in view of the above circumstances as an object to obtain a skin current heating device suitable for small-scale use. According to the present invention, the skin current heating device of each of the following embodiments can be obtained. As in the case of the claims, each aspect is divided into sections, each section is numbered, and if necessary, the other sections are cited in a form in which the numbers are cited. This is to clarify the possibility of combining the features described in each section. (1) A skin current heating device that generates a skin current on an inner surface of a ferromagnetic tube by passing an AC current from an AC power supply through an insulating wire in the ferromagnetic tube, and generating heat by passing an AC current from the AC power supply through the insulating wire. O between the connection terminal to the AC power supply and the insulated wire.
A skin current heating device including a power adjusting device capable of adjusting power in a plurality of stages in an N state (claim 1). In a large-scale skin current heating device having a large thermal inertia, the O
Although stable control with a small temperature change can be performed by N and OFF control, ON and OFF control is insufficient for a small-scale skin current heating device having small thermal inertia. Therefore, in the present invention, the insulated wire is connected to an AC power supply via a power adjustment device capable of adjusting power in a plurality of stages in the ON state. In this way, the temperature of the skin current heating device can be controlled more finely than in the case of ON / OFF control, and stable temperature control can be performed even in a small-scale skin current heating device. Here, "the power can be adjusted to a plurality of levels in the ON state" means that the power can be controlled to two or more levels, and the continuous adjustment is considered to be an infinite number of steps. (2) The power adjusting device includes a primary winding and a secondary winding, both ends of the primary winding are connected to a connection terminal to the AC power supply, and one end of the secondary winding is connected to one end of the insulated wire. And a switch having a plurality of selection terminals at a plurality of locations having different numbers of windings and a changeover switch for selectively connecting the plurality of selection terminals of the transformer to the other end of the insulation wire.
The skin current heating device according to (1). In small-scale skin current heating devices, the overall length of the insulated wire tends to be shorter, and the voltage that can be applied to both ends of the insulated wire is often lower than 100 to 200 volts of a commercial power supply. Therefore, the voltage is reduced by using a transformer, the transformer is provided with a plurality of selection terminals, and an insulation wire is selectively connected to the selection terminal by a changeover switch, and a voltage applied to both ends of the insulation wire is reduced. It is reasonable to be able to adjust in multiple steps. (3) The skin current heating device according to (1), wherein the power adjusting device includes an autotransformer with a sliding brush. The same operation and effect as described above can be obtained by an autotransformer with a sliding brush (Slidac). However, from the viewpoint of improving the safety of the skin current heating device, in particular, in order to improve the safety of the series-type skin current heating device in which the ferromagnetic tube is connected to the power supply in series with the insulated wire, the primary winding and the secondary winding are required. With the next winding,
A transformer having a function of electrically insulating the primary side and the secondary side is more preferable. (4) The power adjustment device includes a phase control type power adjustment circuit that allows the flow of the AC current in the set phase range of the AC current and has a variable set phase range.
The skin current heating device according to (1). (5) The skin current heating device according to (1), wherein the power adjustment device includes an inverter. It is also possible to adjust the calorific value of the skin current heating device by the power variable function of the inverter. (6) A plurality of the ferromagnetic tubes are provided, and the ends of the insulated wires passed through each of the ferromagnetic tubes are connected to each other by a connecting member separate from the insulated wires. (1) to (5) The skin current heating device according to any one of the above items (Claim 2).
In this aspect, one end of an insulated wire penetrating each of the plurality of parallel ferromagnetic tubes is connected to each other by a separate connection member, so that one insulated wire connects a plurality of parallel ferromagnetic tubes in series. A circuit equivalent to that penetrating into the skin current heater can be formed, and the manufacture of the skin current heating device becomes easy. This effect increases as the number of ferromagnetic tubes and the number of insulated wires passed through one ferromagnetic tube (referred to as the number of insulated wires) increase. In a small-scale skin current heating device installed in a narrow space, the number of ferromagnetic tubes is usually large, and the total length of the insulated wire is increased to increase the voltage that can be applied to both ends of the insulated wire. This embodiment is particularly suitable for a small-scale skin current heating device because the number of insulated wires is often increased in order to achieve this. Note that the features of this section can be adopted separately from the features of section (1). (7) The skin current heating device according to (6), wherein the connection member includes a threaded connection member having two fixing screws for fixing an end of the insulated wire. If the connecting member is provided with two fixing screws, the ends of the two insulated wires are fixed to the connecting member by respective fixing screws, so that the two insulated wires are electrically connected by the connecting member. Connection can be made, and connection work becomes easy. It is also possible to provide two through holes or notches in the connection member that allow the insulation wire to penetrate, and solder the insulation wire to the connection member in a state where these through holes and the like are penetrated. (8) The skin current heating device according to (6) or (7), wherein a plurality of the connection members are fixed in a relative position unchanged by a fixing member made of an electrically insulating material. If a plurality of connecting members are fixed to each other with a fixing member made of an electrically insulating material, the plurality of connecting members can be arranged in a narrow space while reliably electrically insulating the connecting members, so that the apparatus can be made compact. Becomes (9) The skin current heating device according to (8), wherein the fixing member includes a fixing unit for fixing the ferromagnetic tube. If the fixing member is provided with fixing means for fixing to the ferromagnetic tube, the relative position of the insulating wire passed through the ferromagnetic tube and the connecting member connecting the same can be reliably fixed, and a stable skin current can be obtained. A heating device is obtained. (10) An insulated wire is wound one or more times in the longitudinal direction of the elongate member made of a ferromagnetic material, and the length of the elongate member is set so as to surround each of two portions of the wound insulated wire extending in the elongate direction of the elongate member. The ferromagnetic tube and the insulated line are formed by forming two ferromagnetic material tube portions extending in the directions, and the skin current heating device according to any one of (1) to (9). (Claim 3). In this aspect, after the insulated wire is wound in the longitudinal direction of the elongated member, the ferromagnetic tube portions surrounding the two portions of the insulated wire are formed, so that it is easy to pass the insulated wire through the ferromagnetic tube portion. It is. This is because the winding operation can be easily performed since the ferromagnetic tube portion has not yet been formed at the time of winding the insulated wire. Note that the features of this section can be adopted separately from the features of section (1) and (6). (11) The longitudinal member is made of a ferromagnetic material and has a cross-sectional shape of an S-shape. After the insulating wire is wound around the center of the S-shape, the S-shape is formed at two positions. (10). The skin current heating device according to (10), wherein the cross-sectional shape is formed into an eight-shape by closing the opening. (12) The longitudinal member is a member made of a ferromagnetic material and having a cross-sectional shape of a shape of ω. After the insulating wire is wound around the center of the shape of ω, two portions of the shape of ω are formed. By closing the opening, the cross-sectional shape was changed to the figure of 8 (1
The skin current heating device according to the item 0). (13) The longitudinal member has a C-shaped cross section 2
The members are fixed back-to-back, and after the insulated wire is wound around the back portion of the combined C-shape, the opening portions of both C-shapes are closed to form an eight-shaped cross section. The skin current heating device according to the above (10). (14) The skin current heating device according to any one of (11) to (13), wherein the opening of the elongated member is closed by a closing member that is a separate member from the elongated member. In this embodiment, the elongate member does not need to have a deformability as in the following embodiment. The closing member may be simply brought into contact with the longitudinal member, but is preferably integrated by welding or the like. (15) The long member is formed by bending a long rectangular plate, and the two openings are welded after being closed by deformation (plastic deformation or elastic deformation) of the long member ( 11) The epidermal current heating device according to any one of the paragraph (13). According to this aspect, the number of welding lines can be reduced as compared with the case where the closing member is welded to the longitudinal member, so that the manufacturing cost and the magnetic resistance of the ferromagnetic tube can be reduced. Since a ferromagnetic tube functions as a magnetic path of a magnetic field formed by a current flowing through an insulating wire, it is desirable that the magnetic resistance be as small as possible. According to welding, the magnetic resistance can be reduced as compared with a case where the longitudinal member and the closing member are simply brought into contact with each other. However, since the welded portion generally has a lower magnetic permeability than the base material, the welded portion is The smaller the number, the lower the magnetic resistance. (16) The longitudinal member is a longitudinal rectangular member, and after the insulating wire is wound around the rectangular member, cover members made of a ferromagnetic material separately from the rectangular member are provided on both side surfaces of the rectangular member. Fixed to surround adjacent space (10)
Skin current heating device according to the item. (17) In the paragraph (16), a groove extending in the longitudinal direction is formed on another side surface of the rectangular member located between the two side surfaces, and a side edge of the cover member is fitted into the groove. A skin current heating device as described. (18) The number of the cover members is two, the two grooves are formed in parallel with each other, and the respective side edges of the two cover members are fitted into each of the two grooves (17). The skin current heating device according to the item (2). (19) The cover member is a single tubular body, and is fitted to the outside of the rectangular plate member, and the inner side surface of the tubular body and the opposite side surfaces of the rectangular member are different from each other. The skin current heating device according to item (16), which is fixed. (20) The skin current heating device according to any one of (16) to (19), wherein the rectangular plate member and the cover member are integrated by welding. In particular, in a mode in which two grooves are formed on one side surface of the elongated member, the gap between the side edges of the two cover members can be increased by increasing the interval between the grooves. If the wide gap is welded, the longitudinal member and the cover member can be joined to each other by a weld having a large area, and the magnetic resistance of the ferromagnetic tube can be reduced. (21) The skin current heating device according to any one of (1) to (20), wherein the ferromagnetic tube is covered with an electromagnetic shield made of aluminum. Aluminum has the ability to reflect or absorb electromagnetic waves, so if the ferromagnetic tube is covered with an electromagnetic shield made of aluminum, electromagnetic waves can be effectively prevented from going outside, and the human body due to electromagnetic waves can be prevented. Can be avoided. The features of this section can be adopted separately from the features of (1), (6), (10) and the like. (22) The skin current heating device according to (21), wherein the electromagnetic shield covers the ferromagnetic tube in close contact. If the electromagnetic shield closely covers the ferromagnetic tube, heat is transmitted from the ferromagnetic tube to the electromagnetic shield by conduction, and the temperature of the ferromagnetic tube when releasing the same amount of heat to the atmosphere is It is lower than when an air layer exists between the electromagnetic shield and the ferromagnetic tube. The temperature to which the insulated wire is exposed can be low, and the use of the organic insulating material is facilitated. Further, if both are in close contact with each other, the electromagnetic shield also plays a role of reinforcing the ferromagnetic tube, so that a heating element having high strength can be obtained. (23) The skin current heating device according to (22), wherein the electromagnetic shield is cast around the ferromagnetic tube. According to the cast-in technique, a heating element in which an aluminum electromagnetic shield closely covers a ferromagnetic material can be easily manufactured. (24) The skin current heating device according to (21), wherein the electromagnetic shield includes the ferromagnetic tube with a gap therebetween. The number of ferromagnetic tubes included in the electromagnetic shield can be easily changed, and it becomes easy to manufacture heating elements having different heating values for the same heat radiation area. (25) The electromagnetic shield includes a radiation fin (21) to
The skin current heating device according to any one of (24). (26) The skin current heating device according to any one of (21) to (25), wherein the electromagnetic shield includes a plate-shaped portion parallel to a tangent plane to the outer peripheral surface of the ferromagnetic tube. According to this aspect, a heating element suitable for heating a floor or a wall can be obtained. This is because a flat heat dissipation surface can be obtained by arranging a plurality of plate portions. (27) The insulation layer of the insulation wire is made of an inorganic insulation material
The skin current heating device according to any one of (1) to (26). Since the inorganic insulating material generally has higher heat resistance than the organic insulating material, it becomes easy to increase the heat generation density of the ferromagnetic tube. The features of this section are (1), (6), (10),
Although it is possible to adopt the features separately from the features of the item (21), it is convenient to adopt the features of the item (6) in combination. According to the present invention, the following skin current heating tube and a method for manufacturing the skin current heating tube are also obtained. (28) At least one insulated wire is passed through the ferromagnetic tube, and both ends of the insulated wire are fixed to both ends of the ferromagnetic tube in an electrically insulated state, and protrude from both ends to the outside. Skin current heating tube. The heating tube of this embodiment is
It can be suitably used for the production of the skin current heating device described in (6). (29) At least one insulating tube made of an electrically insulating material is fixedly provided in the ferromagnetic tube in parallel with the axial direction of the ferromagnetic tube, and a bare wire having no insulating coating is inserted therein. The heating tube according to item (28). An insulated wire can be formed by inserting a bare wire through the insulating tube. It is also possible to provide a plurality of insulating tubes, and in that case, it is possible to form a plurality of through-holes in one rod-shaped body and integrate the plurality of insulating tubes. (30) An insulated wire is wound one or more times in the longitudinal direction of the elongate member made of a ferromagnetic material, and the wound insulated wire is encircled in the longitudinal direction of the elongate member so as to surround each of two portions extending in the elongate direction of the elongate member. A method for manufacturing a skin current heating tube in which two extending ferromagnetic tubes are formed mainly of a longitudinal member.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing a configuration of a skin current heating device according to an embodiment of the present invention. The skin current heating device includes a power adjustment circuit 10 and a skin current heating element 12. The power adjustment circuit 10 includes a transformer 14 and a changeover switch 16, and is connected to a commercial power supply 20 via a main switch 18 and a connection terminal 19. Transformer 14
Comprises a primary winding 22 and a secondary winding 24, and a secondary winding 24
Has one common terminal 26 and a plurality of selection terminals 28 drawn from a plurality of locations having different numbers of turns.

[0006] Instead of the power adjustment circuit 10,
It is also possible to employ the power adjustment circuits shown in FIGS. The power adjusting circuit shown in FIG. 2 includes a single winding transformer 36 having a sliding brush having a single winding 32 and a brush 34 sliding on the single winding 32. The power adjustment circuit of FIG. 3 includes a transformer 38 and a forward / reverse parallel single-phase AC switch 40. The transformer 38 is provided for transforming and insulating the commercial power supply 20, and the forward / reverse parallel single-phase AC switch 40 includes a thyristor 42 connected in parallel in the forward and reverse directions. By controlling the firing phase of the thyristor 42, the phase range in which the current can flow is controlled. The forward / reverse parallel single-phase AC switch 40 is a kind of a phase control type power adjustment circuit. 4 includes a transformer 38 and an inverter 44.
The inverter 44 converts the alternating current into a direct current and then converts it back into an alternating current. In the meantime, the inverter 44 changes the output power by changing at least one of the voltage and the frequency.

FIG. 5 conceptually shows an example of the skin current heating element 12. In the figure, reference numeral 50 denotes a steel tube as a ferromagnetic tube. The steel pipe 50 is commercially available and has an inner diameter D and a thickness T.
And the length L, the shape and dimensions satisfy the relationship of T ≧ 2S, D≫S, L お よ び D. Where S is S =
5030√ρ / μf is the skin depth (cm), ρ is the resistivity (Ω / cm), μ is the magnetic permeability, and f is the AC frequency (Hz).

[0008] A plurality of steel pipes 50 are welded together by a plurality of connecting members 52 to form a steel pipe assembly 54 as a ferromagnetic tube assembly. A plurality of insulated wires 56 are passed through each steel pipe 50, and the ends of two insulated wires 56 passed through adjacent steel pipes 50 are connected to each other by connecting members 58, so that all of the insulated wires are connected. 56 are connected in series. Although the number of insulating wires 56 passing through each steel pipe 50 is set to two in the figure, it should be appropriately determined according to a desired calorific value or the like. Both ends of the series connection of the insulated wires 56 are connected to the connection terminals 60 and 62, respectively. When tracing the series connection body from one connection terminal 60 side to the other connection terminal 62, the insulation wires 56 are connected so that the traveling directions of the plurality of insulation wires in each steel pipe 50 are all the same. . The insulated wire 56 is 1
In practice, the wire is shown as a single wire, but in practice, a stranded wire composed of multiple fine copper wires is covered with an electrically insulating layer made of an organic insulating material such as butyl rubber insulated vinyl, or a stranded wire or body. The single wire is covered with an electric insulating layer such as an insulator tube made of an inorganic insulating material such as magnesia. The former is preferable when the heat generation density (for example, the amount of heat generated per unit length) in the steel pipe 50 is low, and the latter is preferable when the heat generation density is high.

When an alternating current is supplied to the insulated wire 56 and the current flows in the direction shown by the arrow, a magnetic field is formed around the insulated wire 56, and an opposite current flows through each steel pipe 50 under the influence of the magnetic field. . This current flows through the inner skin of the steel pipe 50 in the opposite direction to the current of the insulated wire 56 by a well-known skin action, and then flows in the outer peripheral portion of the steel pipe 50 in the opposite direction. As a result, the inner skin of the steel pipe 50 having a large current density mainly generates heat, is transmitted to the outer peripheral side portion by conduction, and the temperature of the entire steel pipe 50 is increased. Eventually, the supply of alternating current to the series connection of the insulated wires 56 causes the steel pipe assembly 54 to generate heat.

In the above embodiment, the ferromagnetic tube is constituted by a commercially available steel tube 50, and the insulating wire 56 cut to a certain length longer than the steel tube 50 is inserted in the axial direction. It is not essential that the magnetic tube has a circular cross-sectional shape and that the insulating wire is inserted in the axial direction. For example, the configuration shown in any of FIGS. 6 to 12 can be adopted.

The skin current heating tube 68 shown in FIG. 6 has two C-shaped members 70 having a C-shaped cross section as shown in (1).
The present embodiment uses a longitudinal member 72 which is joined by appropriate means such as electric resistance welding in a state where the letter C is back-to-back. An insulated wire 76 is wound one or more times (a plurality of times in the illustrated example) along the longitudinal direction of the joint 74 of the elongated member 72. This winding operation of the insulated wire 76 can be performed easily because the insulated wire 76 can be passed through the opening 78 of the C-shaped member 70. After the winding operation is completed, as shown in (2), the opening 78 of each C-shaped member 70 is closed by the closing member 80, and the C-shaped member 70
The two ferromagnetic tube portions 82 are formed by integrating the and the closing member 80 by welding. Each ferromagnetic tube portion 82 is formed so as to surround two portions of the insulated wire 76 wound around the coupling portion 74, each extending along the longitudinal direction of the coupling portion 74. Is a closed curve and forms a completely closed magnetic path. The symbol shown in the upper ferromagnetic tube portion 82 in (2) indicates that the insulated wire 76 extends from the near side to the far side, and is indicated in the lower ferromagnetic tube portion 82. The symbol shown indicates that the insulated wire 76 extends from the far side to the near side. The same applies to other figures.

As shown in (1), a skin current heating tube 88 shown in FIG. 7 includes a rectangular member 90 made of steel, which is a kind of longitudinal member.
After the insulated wire 92 is wound one or more times (a plurality of times in the illustrated example) along the longitudinal direction of the rectangular member 90, as shown in (2), two steel cover members 94 are fixed by welding. It was done. The insulating wire 92 is wound along a pair of side surfaces of the rectangular member 90, and two grooves 96 are formed on each of the other pair of side surfaces in parallel with each other. The cover member 94 is a long member having a C-shaped cross-sectional shape, and both side edges corresponding to both ends of the C-shape of each cover member 94 are fitted into the respective grooves 96. It is integrated with the rectangular member 90 by welding. By this integration, two ferromagnetic tube portions 98 are integrally formed. The welding bead fills the two grooves formed by the two cover members 94 and the rectangular member 90, and has a wide cross-sectional area. Has a small magnetic resistance. However,
It is not always necessary to weld the rectangular member 90 and the cover member 94. For example, the magnetic resistance can be reduced by bringing the two members into a pressed state with a wide area.

As shown in (1), the skin current heating tube 104 shown in FIG. 8 has a longitudinal member 106 having a cross section of an S-shape.
After the insulation wire 108 is wound around the center of the letter S, (2)
As shown in the figure, the longitudinal member 106 was plastically deformed until both ends of the S-shape respectively contacted the central portion, and then welded, so that the cross-sectional shape was formed into a figure-eight shape. Things. As a result, the two ferromagnetic tubes 11
0 surrounds the two portions extending in the longitudinal direction of the insulated wire 108, respectively. The longitudinal member 106 can be manufactured by, for example, plastically processing a rectangular steel plate or extruding or drawing a molten steel.

As shown in (1), a skin current heating tube 116 shown in FIG. 9 is a longitudinal member 118 having a transverse cross-sectional shape of ω.
After the insulated wire 120 is wound around the center of the ω-shape, (2)
As shown in FIG. 7, the longitudinal member 118 is plastically deformed until both ends of the character ω contact the center, respectively, and then welded. As a result, the two ferromagnetic tube sections 12
2 are formed integrally, and the cross-sectional shape becomes a figure eight. The elongated member 118 can also be manufactured by plastic working, extrusion, drawing, or the like. However, the illustrated longitudinal member 11
Numeral 8 is manufactured by plastic working of a rectangular plate.

The skin current heating tube 130 shown in FIG. 10 uses a longitudinal member 132 manufactured by casting or the like. The cross-sectional shape of the elongated member 132 is an E-shape.
After the insulated wire 134 is wound around the central protrusion of the letter "U", the two openings 136 of the letter "E" are closed by a closing member 138, respectively, and then integrated by welding. As a result, the two ferromagnetic tube sections 140 are integrally formed. The skin current heating tubes 68, 88, 10 described above
The ferromagnetic tubes, which may also be referred to as twin tubes constituting 4,116,130, can be used alone, but these can be used together with a bonding material 52 like a steel tube 50 in FIG.
To form a ferromagnetic tube assembly.

In the skin current heating tube 144 shown in FIG. 11, after an insulated wire 148 is wound around a strip-shaped elongated member 146, a cover member 150 made of a steel pipe is fitted on the outside of the elongated member 146, and resistance welding is performed. , Laser welding or the like. As a result, two ferromagnetic tube portions 151 each surrounding an appropriate number of insulated wires are formed.

The skin current heating tube 152 shown in FIG.
53 is provided with an insulating tube 154 made of synthetic resin or ceramics having excellent heat resistance inserted therein. Insulation tube 15
Reference numeral 4 has a plurality of through holes penetrating in the axial direction, and an insulated wire is formed by passing a bare wire 155 through each of these through holes. Plugs 156 made of an electrically insulating material such as a synthetic resin having excellent heat resistance are fixed to the openings at both ends of the steel pipe 153 by appropriate means such as press fitting. A plurality of through holes are formed in the plug 156, and each bare wire 155 protrudes from each through hole to the outside.

The ferromagnetic tube such as the steel tube 50 described above can be coated with aluminum (including an aluminum alloy) as illustrated in FIGS. In the heating element 158 of FIG. 13, the outer peripheral surfaces of the plurality of steel tubes 50 are respectively covered with outer tubes 159 made of aluminum, and are connected by the plurality of fins 160. The outer tube 159 and the fin 160 are
Is formed by a casting technique in which molten aluminum is poured into a mold in which is set. The fins 160 are mainly provided to increase the heat radiation area, but also have a function of integrally connecting the plurality of steel pipes 50. The outer tube 159 and the fin 160
May be formed by plastic working of an aluminum plate or the like.

In the heating element 162 of FIG. 14, an aluminum portion formed by casting a plurality of steel pipes 50 has an outer pipe portion 163 that closely covers the outer peripheral surface of the steel pipe 50;
A flat plate 164 and a leg 165 are formed integrally with the outer tube 163. The flat plate portion 164 has a plane 166 parallel to a common tangent plane to the plurality of steel pipes 50.
The leg 165 is projected from the lower surface of the flat plate 164 at right angles to the flat plate 164. Flat plate part 1
64 is generally in the shape of an elongated rectangular plate, and has legs 165.
Are formed at intervals in the longitudinal direction of the flat plate portion 164. Therefore, when the plurality of heating elements 162 are arranged in a state where the leg 165 is supported on a horizontal plane, the relatively narrow plurality of planes 166 cooperate to form a wide plane and constitute a heating plate having a flat plate shape as a whole. . Similarly, leg 1
If a plurality of heating elements 162 are arranged with the 65 supported on a vertical surface, a heating wall can be formed. Although these heat generating floors and heat generating walls can be used as they are, it is desirable to cover them with a plate material, wallpaper, a synthetic resin sheet or the like. Painting is also possible. The heat generating floor and the heat generating wall are collectively referred to as a heat generating plate as necessary.

In the heating element 170 shown in FIGS. 15 and 16, a plurality of steel pipes 50 are made of an outer pipe 17 made of aluminum.
2 housed. The outer pipe 172 has a thickness capable of accommodating the plurality of steel pipes 50 with a gap left therebetween.
74 are filled. As the filler 174, a synthetic resin having excellent heat resistance and thermal conductivity is suitable. In the present embodiment, a material obtained by pouring and curing an epoxy resin is used as the filler 174. Although it is possible to omit the filler, in that case, heat is transmitted from the steel pipe 50 to the outer pipe 172 by radiation and convection, and the heat transfer becomes poor as compared with the case of conduction. Inevitably, the temperature of the steel pipe 50 and the temperature of the insulated wire inside the steel pipe 50 are increased. Since both ends of the outer pipe 172 are closed by aluminum covers 176 and 178, respectively, and the entire steel pipe 50 is covered with an aluminum layer,
Leakage of the electromagnetic wave to the outside of the heating element 170 can be favorably prevented. 13 and 14, the insulated wire 1 is used.
Although 80 is shown as one continuous line, in practice, as shown in FIG. 5, it is also possible to connect the ends of a plurality of insulated wires with separate connection members.

In FIG. 5, the connecting member 58 for connecting the ends of the plurality of insulated wires 56 is conceptually shown. However, actually, the connecting members 58 are connected by means shown in FIGS. 17 to 21, for example. . The connecting member 186 of FIG. 17 includes a main body 188 made of a copper alloy and two fixing screws 190. The main body 188 has a generally flat shape,
It has two notches 192 and two female screw holes (not shown), and a fixing screw 190 is screwed into the female screw hole. An end 194 of the insulated wire 56 from which the insulating layer has been removed is engaged with the notch 192 to position the loosened fixing screw 190, and is wound around the loosened fixing screw 190.
When the fixing screw 190 is tightened, the ends 194 can be electrically connected to each other.

In the connecting means shown in FIGS. 18 to 20, a connecting member 200 for connecting a plurality of steel pipes 50 to each other and a connecting member 202 for connecting ends of a plurality of insulated wires 56 are fixed to each other. Things. The coupling member 200 is a metal rod-shaped member, and has a plurality of fitting holes 204 into which the ends of the steel pipe 50 can be fitted exactly. Steel pipe 50
Are fitted in the fitting holes 204 and are fixed by bolts 206 as shown in FIG. A groove 208 having a rectangular cross section is formed on the surface of the coupling member 200 opposite to the side where the fitting hole 204 is formed, and the groove 208 is filled with a heat-resistant synthetic resin 210. A plurality of connection members 202 are embedded in the resin 210. Each connection member 2
Numeral 02 is provided integrally with a cylindrical portion 214 at both ends and a lead portion 212 connecting the cylindrical portions 214,
10 is buried when filling the groove 208. The relative position between the plurality of connection members 202 and the relative position between the connection member 202 and the coupling member 200 are determined by the heat-resistant synthetic resin 210.
, And electrical insulation between them is also achieved by the heat-resistant synthetic resin 210. The connection of the insulated wire 56 to the connection member 202 is performed by inserting each end of the insulated wire 56 from which the insulating layer has been removed into each cylindrical portion 214 and soldering the same. As shown in FIG. 21, the cylindrical portion 214 is made to protrude from the heat-resistant synthetic resin 210 by a predetermined length, and after inserting the end of the insulating wire 56 into the cylindrical portion 214, the projecting portion of the cylindrical portion 214 is pinched. The connection may be made by crushing with a tool such as.

The skin current heating device according to the present invention is, for example, a heating element 158, 16 shown in FIGS.
2 and 170 alone, or as shown in FIG.
A plurality of heating elements 162 shown in FIG.
As shown in FIG. 5, a plurality of heating tubes shown in FIG. 12 and the like are arranged in a plane to form a heating bar, or a heating bar is housed in a hollow plate-like frame to be used as a heating plate. Can be. It can be used for various purposes. For consumer use, it can be used for house parts such as warming linings, simple and small auxiliary heaters, warming furniture such as warming chairs, etc. For industrial use, it can be used for warming storage and warming liquid tanks. It can be used as a heat source. Hereinafter, a part thereof will be specifically described.

FIG. 22 shows a footrest provided under a counter in a bar, a dining room or the like. This footrest is obtained by attaching a plurality of legs 220 to the long heating element 170 shown in FIG. If the leg 220 is fixed to the floor, it can be easily installed, and the foot can be rested while warming.

An experiment was conducted to confirm the performance of the skin current heating device according to the present invention. As shown in FIG. 23, the insulation wire 243 is passed through the two steel pipes 242 a plurality of times, and the voltage of the commercial power of 60 Hz is applied to the insulation wire 243 in the atmosphere of 12 ° C. by the autotransformer 244 with a sliding brush as appropriate. FIG. 24 and FIG. 25 show the results of measuring the voltage, current, and power with a voltmeter 245, an ammeter 246, and a wattmeter 247 by applying a voltage. However, the conditions in each case are as follows. In the case of Fig. 24 Steel pipe 242 Type JIS G3452 SGP-B-20A Length 1000mm Outside diameter 27.2mm Wall thickness 2.8mm Insulated wire 243 JIS C3306 vinyl flat cord (VFF 2 core
1.25 mm ² 50 / 0.18) Total conductor resistance of about 0.56 Ω for 16 turns, total conductor resistance of about 0.28 Ω for 8 turns In the case of FIG. 25 Steel pipe 242 Type JIS G3452 SGP-B- 15A Length 1000 mm Outer diameter 21.8 mm Wall thickness 2.8 mm Insulated wire 243 Same as in FIG. It should be noted that the total conductor resistance in the case of 12 turns is about 0.42Ω. From the results of this experiment, it can be seen that a small-scale skin current heating device is sufficiently feasible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a skin current heating device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram showing a skin current heating device according to another embodiment of the present invention.

FIG. 3 is a configuration diagram showing a skin current heating device according to still another embodiment of the present invention.

FIG. 4 is a configuration diagram showing a skin current heating device according to still another embodiment of the present invention.

FIG. 5 is a front sectional view conceptually showing an example of a skin current heating element of the skin current heating device according to one embodiment of the present invention.

FIG. 6 is a view for explaining the manufacture of a skin current heating element different from the skin current heating element of FIG. 5;

FIG. 7 is a view for explaining the manufacture of a skin current heating element different from the skin current heating element of FIG. 6;

FIG. 8 is a view for explaining the production of still another skin current heating element.

FIG. 9 is a view for explaining the production of still another skin current heating element.

FIG. 10 is a view for explaining the production of still another skin current heating element.

FIG. 11 is a view for explaining the production of still another skin current heating element.

FIG. 12 is a front sectional view showing a skin current heating element of a skin current heating device according to another embodiment of the present invention.

FIG. 13 is a perspective view showing a heating element of a skin current heating device according to still another embodiment of the present invention.

FIG. 14 is a perspective view showing a heating element of a skin current heating device according to still another embodiment of the present invention.

FIG. 15 is a perspective view showing a skin current heating element of a skin current heating device according to still another embodiment of the present invention.

16 is a front sectional view of the skin current heating element of FIG.

FIG. 17 is a front view showing an example of a connecting member used in the skin current heating element shown in FIG.

FIG. 18 is a front sectional view showing another example of the connection member used in the skin current heating element shown in FIG. 5;

FIG. 19 is a right side view of the connection member of FIG. 18;

FIG. 20 is a plan sectional view of the connecting member of FIG. 18;

FIG. 21 is a view corresponding to FIG. 18 showing still another example of the connection member used in the skin current heating element shown in FIG. 5;

FIG. 22 is a perspective view showing a footrest which is an application example of the skin current heating device using the skin current heating element shown in FIGS. 15 and 16;

FIG. 23 is a perspective view showing a device used in an experiment for testing the performance of the skin current heating device according to the present invention.

FIG. 24 is a graph showing the results of the above experiment.

FIG. 25 is a graph showing another result of the above experiment.

[Explanation of symbols]

10: Power adjustment circuit 12: Skin current heating element 1
4: Transformer 16: Changeover switch 36: Single-turn transformer with sliding brush 40: Forward / reverse parallel single-phase AC switch
42: thyristor 44: inverter 50: steel pipe 52: connecting member 54: steel pipe assembly 56:
Insulated wire 58: connection member 60, 62: connection terminal
68,88,104,116,130,144,15
2: Skin current heating tube 72, 106, 118, 13
2,146: Longitudinal members 76,92,108,12
0, 134, 148: insulated wires 82, 98, 110,
122, 140, 151: Ferromagnetic tube section 80, 13
8: closing member 153: steel pipe 154: insulating pipe
155: bare wire 158, 162, 170: heating element
172: outer tube

Claims (4)

[Claims] 1. A skin current heating apparatus for generating a skin current on an inner surface of a ferromagnetic tube by passing an AC current from an AC power supply through an insulating wire in the ferromagnetic tube and generating heat by passing an AC current from the AC power supply through the insulating wire. Between the connection terminal to the AC power supply and the insulated wire.
A skin current heating device comprising a power adjusting device capable of adjusting power in a plurality of stages in a state. 2. The ferromagnetic tube according to claim 1, wherein a plurality of said ferromagnetic tubes are provided, and ends of said insulated wires passing through each of said ferromagnetic tubes are connected to each other by a connecting member separate from said insulated wires. A skin current heating device as described. 3. An insulated wire is wound one or more times in the longitudinal direction of a longitudinal member made of a ferromagnetic material, and each of the wound insulated wires surrounds each of two portions extending in the longitudinal direction of the elongate member. 2. The ferromagnetic tube and the insulating wire are formed by forming two ferromagnetic material tube portions extending in the longitudinal direction of the ferromagnetic tube.
Or the skin current heating device according to 2. 4. The skin current heating device according to claim 1, wherein the ferromagnetic tube is covered with an electromagnetic shield made of aluminum.