JPS6347238B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heating coil used in an induction heating device.

Conventional configurations and their problems Conventionally, in order to make it easier to spirally wind a heating coil, a Ritsutsu wire is generally used, which is a collection of twisted wires with an insulating layer on a conductor such as copper wire. Was. A conventional example is shown in FIG. 1, in which a heating coil is constructed by providing a wire 2 on a coil base 1 and fixing it with an adhesive 3 such as varnish.

As shown in the lead portion 4, the strands are twisted into tens to hundreds of strands, so that the collective cross section of the strands after the strands is circular. This circular wire was spirally wound to obtain a predetermined diameter and inductance. This is because circular wire is easier to wind when winding, and dimensional accuracy can be obtained.

OBJECT OF THE INVENTION An object of the present invention is to solve the following disadvantages of the conventional wire by using a wire having a fusion layer provided on the outer periphery.

The first purpose is to reduce the twist pitch of the strands, save resources by reducing the weight of the heating coil, and reduce loss in the heating coil.

Furthermore, since the wire assembly of the wires is not circular, it is possible to firmly fuse the wires with the adjacent wires. The second objective is not to use adhesive varnish. Since it is fixed mechanically, it is securely fixed to the base and ensures long-term reliability.

In addition, the work environment can be improved without the generation of strange odors, and the curing time of adhesives such as varnishes generally takes a long time, but these problems are solved all at once.

Structure of the Invention In order to achieve the above object, the present invention uses a wire having a fusion layer on an insulating layer covered with a conductor, and the diameter of the wire, the number of wires gathered, and the number of twists. This uses clustered lines whose product is approximately 70 or less per 30cm length.

DESCRIPTION OF THE EMBODIMENTS FIG. 2 shows a sectional view of a wire according to the present invention, and shows a wire 8 having an insulating layer b covering the entire circumference of the conductor 5 and further comprising a fusion layer 7.

High-frequency current flows through the conductor 5, but due to the skin effect, the current concentrates only on the surface, so use the penetration depth determined by the frequency as a guide and decide on an effective diameter.
Furthermore, the required number of strands is determined based on the cross-sectional area required for the entire current to flow, and the wires are assembled.

The insulating layer 6 has a heat resistance temperature that can withstand the operating temperature. Furthermore, when the fusion layer 7 is heated to the fusion temperature, adjacent parts are fused and the strands or clustered strands are bonded.In order to achieve fusion bonding, in which the strands are heated to a fusion temperature, electric current is passed through the strands and the strands themselves act as a heater, or This is possible by increasing the temperature of the welding layer from the outside.

FIG. 3 shows an embodiment using a heating coil.

A heating coil 9 is constructed by sequentially winding a set of tens of wires 8 in a spiral shape starting from the center.

The heating coil 9 has a disc-like shape because the parts where the fusion layers are in contact with adjacent lines are fused. The heating coil 9 is fixed to the coil base 1 with a coil holder 10 and caulking 11. The coil holder 10 is located on the circumference of the heating coil 9 and fixes the heating coil 9 from the periphery. Since stress is applied to the lead part 4 during assembly, the coil holder 10 is provided at a position to cover the stress so that the fused part at the lead outlet does not come off. Although the lead portion 4 does not need to be twisted, it is desirable to provide twisting in order to facilitate assembly and wiring. This twisting is effective for threading through tubes and for tasks such as soldering the tip. This twist pitch is an embodiment in which the twist pitch is made considerably small so that the wires do not fall apart when the lead portion is bent onto the wiring.

In the above case, the heating coil 9 is not twisted at all and only the lead portion 4 is twisted, but if the heating coil 9 is developed in a straight line, the lengths between the individual wires will be uneven, and the wires on which the current will concentrate will be twisted. may occur.

To solve this problem, the heating coil section may also be twisted appropriately. On the other hand, if the twist pitch is further added, the assembled lines will have a circular cross section as shown in the conventional example in FIG. 1, and the fusion strength between the assembled lines will be extremely deteriorated. The relationship between this fusion force and the coefficient K is shown in FIG.

If the product K of the diameter of the strands, the number of assembled wires, and the number of twists is set to 50 to 70 or less per 30 cm length, the fusion strength between the assembled wires will not be extremely deteriorated. For example, if 0.5φ x 20 pieces x 2 (number of pitches/30cm), K = 20, and as shown in Figure 4, the distance between each element wire and between the collective wires is almost 100%.
However, if the value exceeds 90 to 100, the cross section of the assembled lines becomes circular, and the fusing force between the assembled lines deteriorates. On the other hand, since the lead portion 4 comes apart, it is twisted at the pitch required for the work as described above. In this case, the fusion force between the set lines can be set independently. When the twist pitch is set as in the present invention and K is set to approximately 70 or less, a degree of freedom is obtained due to the gap between the strands, so forming the assembled wire can be done relatively easily without destroying the insulating layer.

FIG. 5A shows another embodiment in which the heating coil 9 is fixed to the coil base 1 by forming the clustered wires of the strands 8 into an elliptical shape, expanding the adjoining range between the clustered wires and increasing the fusion force. It shows the case.

FIG. 5B shows still another embodiment, in which a group of wires 8 at the lowest pitch where no current concentrates is formed into a substantially square shape to increase the welding force in the same way as in FIG. 5A. and attach the heating coil 9 to the coil base 1.
This is the case where it is fixed to .

Figures A and B are the conditions for forming,
It is possible to make the diameter of the entire heating coil relatively precise.

Effect of the invention 1: Since the heating coil is made of wire bundles wound at the lowest pitch to ensure fusion bonding strength, the length of each strand can be shortened, and therefore the weight can be reduced. At the same time, it is effective as a resource saving measure.

2. The overall length of the heating coil can be short, reducing loss. Therefore, the thermal efficiency of the entire device increases.

3. There is no need to use varnish as the entire heating coil can be fused together with a fusing layer. Therefore, no strange odor is generated due to varnish.

4. Because it is mechanically fixed to the coil base, only the coil can be replaced. Previously, it was glued together, so the entire coil base had to be replaced.

5. Since the coil base and heating coil are fixed mechanically, there is no thermal deterioration of varnish, etc., and long-term reliability can be ensured.

6. The twist pitch of the wire assembly between the heating coil and the lead part is different, making it easier to wire the lead part.

7. The coil holder fixes the coil at the outer periphery, so it holds the heating coil over a wide area.
The coil part can be fixed to withstand drops and vibrations using only fusion strength.

8. Since the coil holder fixes the exit part of the lead, the holder can withstand external stress and there is no need to rely solely on fusion strength.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a heating coil showing a conventional example, Fig. 2 is a cross-sectional view of a heating coil, Fig. 3 is a cross-sectional view of a heating coil showing an embodiment of the present invention, and Fig. 4 is a fusion force and coefficient. 5A and 5B are sectional views showing other embodiments of the present invention. 1...Coil base, 2...Ritutsu wire, 3...
Adhesive, 4... Lead portion, 5... Conductor, 6... Insulating layer, 7... Fusion layer, 8... Element wire, 9... Heating coil, 10... Coil holder.

Claims (1)

[Claims] 1. Using a wire that further has a fusion layer on an insulating layer covered with a conductor, the product of the diameter of the wire (mm), the number of wires to be assembled, and the number of twists is 30 cm. per length,
A heating coil used for high-frequency induction heating consisting of wires with a diameter of approximately 70 or less. 2. A heating coil as set forth in claim 1, in which the twist pitch of the assembled wires of the spirally wound portion and the lead portion is changed.