JPS58158889A - Induction heating coil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] This invention relates to improvements in induction heating coils.

By equipping a plurality of 7J0 heating coils in one block or larger size, and applying an arbitrary AC voltage to each coil, an induced current is induced in the heated object passing through the heating coil, and the hysteresis of the heated object is reduced. In induction heating equipment that heats and raises the temperature of the heated object through loss and eddy current loss, a single-layer heating film has generally been used, but in response to recent demands for energy saving, two or more layers have been used. Multilayer wraps have been developed and are beginning to be used.

Figure 1 is an example of this, in which arbitrary layers are wound one after the other, and the number of turns is stacked one after the other, and (1) is AC 1! (2) is a heating coil block, (8) is a DO heated object, and (2) is a multi-layered fill conductor, and the one shown is a two-layered one. This coil conductor is molded with an insulator to prevent short circuits between layers or winding phases.

By the way, in such conventional devices, the coil conductor (
Since the coils are wound in the same winding direction, the coil current flows through the coil conductor (c) as shown in Figure 2. Magnetic flux Φ is generated in the direction of the arrow. Therefore, the object to be heated (3) K-induced electric current is the coil conductor (
2) Current flow. The current vector flows in the opposite direction to the heated object (8), and is divided into the radial current vector Fruel and the longitudinal current vector E! of the heated object (8). When the heated object (8) is decomposed into 2, a potential difference corresponding to the electric current 2 will be generated in the longitudinal direction of the heated object (8). Therefore,
When the object to be heated (Jl) becomes a continuum and is connected to the same metal body or conductor at the inlet and outlet sides of the heating fill block (2) to form a circuit configuration, there is a When the object to be heated is a continuous aggregate such as a billet steel billet, when a shift or gap occurs between the billet steel billets during the transportation process, There is a concern that sparks will occur and product defects will occur due to arc marks and the like.

For this reason, generally, as shown in Figure 8, the outlet side of the heating coil block (2) is inclined, and the objects to be heated (8) are separated by the natural fall of the objects to be heated (3), and the circuit configuration is not established. Alternatively, as shown in FIG. 4, it was necessary to take measures such as forcibly separating the objects to be heated (8) using a delivery pinch roller (6) provided with insulation. Roughly, the same phenomenon also occurs on the skid rail (4) provided as a conveyance guide for the object to be heated (1) in the heating coil block (2), so the heating coil block (2)
It was also necessary to take measures such as insulating either the inlet or outlet end or both ends.

This invention reduces the potential difference induced in the longitudinal direction of the object to be heated by alternately combining each layer of multi-layered coils with right-handed and left-handed winding for each layer, thereby eliminating the drawbacks of the conventional method described above. This is what I am trying to do.

FIG. 5 shows an embodiment of the present invention, in which (1) is an AC power source, (2) is a heating coil block, and (8) is an object to be heated. @ is a right-handed coil conductor wound in the first layer f'I, @ is a left-handed fill conductor wound in the second layer,
The second layer is unwound from the end of the winding of the first layer, and an AC power source (1) is connected between one end of the first layer's coil conductor and one end of the second layer's coil conductor. (7) is an insulating layer.

Here, the induced current W generated in the object to be heated (8) from the coil conductor (A) that is being watched is 2v! JK shows a similar vector configuration, and the induced current W generated in the heated object (3) by the left-handed coil conductor (to) is the 6th
The vector configuration is as shown in the figure, and the induction generated by both coil conductors (81K) is caused by the current vectors in the axial direction of the flow (E1, HFi) being in opposite directions and canceling each other out. The longitudinal potential difference that occurs is eliminated or significantly reduced.

In one example, the number of turns of the heating coil in each layer was the same and the calendar number was an even number, but if the current values of the opposing induced current vectors generated in the object to be heated are the same or equivalent, right-handed, Even if the number of left-handed windings is different or the calendar number is an odd number layer, the effect of the present invention will not change in any way. Further, although an insulating layer (7) is provided between each layer in FIG. 5, the above-mentioned insulating layer can be omitted if the insulation of the molded insulator of the coil conductor is reinforced. Further, even if the coil conductor is taped with insulating tape or the like instead of the molded insulator, the insulating effect remains the same and the effects of the present invention are not diminished.

As described above, according to the present invention, the drawbacks of the conventional device can be eliminated very easily and the entire induction heating device can be simplified.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional heating filter, 2nd FgJ is an explanatory diagram of the configuration of a right-handed heating coil, Figs. 8 and 4 are a front view of an induction DO heating device using a conventional heating coil, and Fig. 5 6 is a sectional view showing one embodiment of the present invention, and FIG. 6 is a diagram illustrating the configuration of a left-handed heating coil. In the figure, (1) is an AC power supply, (2) t- is a heating coil block, (8) is an object to be heated, (2) is a right-handed fill conductor,
@ is a left-handed coil conductor, and (7) is an insulating layer. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno −

Claims (1)

[Claims] (In a heating coil with multiple turns of 1 to 1 or more and multi-layered of 2 or more layers, the winding direction is changed for each layer of the coil, such as right-handed winding and left-handed winding, and each coil An induction heating coil 0 characterized in that an AC power source is connected to the coils so that current flows in the same rotational direction. The induction heating coil according to claim 1, characterized in that the number of turns of the coil is such that current vectors in the winding axis direction cancel each other out. (8) Between each layer of the multi-layered heating coil. The induction heating coil according to claim 1 or 2, characterized in that an insulating layer is provided on the induction heating coil.