JPS625036Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention is a multilayer induction heating coil using a hollow conductor with a rectangular cross section for use in induction heating devices or induction melting devices used for heating and melting metals. Regarding. [Prior art and its problems] Since such induction heating coils have high operating temperatures, they are generally water-cooled to protect the insulator and for other purposes. In this case, in order to directly cool the coil conductor with water, the coil conductor is often hollow and square in cross section and wound spirally so that the cooling water passage is formed in one piece. By the way, if the heating coil is wound in multiple layers, the coil conductor must ride on top of the first layer when moving from the first layer to the second layer. At this run-up point, the coil conductor must be bent sharply outward and enlarged from the first layer's winding diameter to the second layer's winding diameter. It is difficult to make a sudden bend in the coil conductor, and there is a risk that the insulation in that part may be damaged. Such a conventional example will be explained based on FIGS. 1 and 2, and FIGS. 6 and 7. Figure 1 shows a coil conductor wound spirally to form each layer, then the second layer is wound on top of the first layer, the third layer is wound on top of the second layer, and so on to form a multilayer induction heating coil. FIG. 3 is a front view showing the first layer in the case where the first layer is wound and the part where the winding of the second layer starts after riding on the first layer at the end of winding of the first layer. 1 is a coil conductor, and the coil conductor 1 is spirally wound on a winding frame (not shown) from one end 1' in the order of turns 2 and 3. In the figure, the first layer is formed by winding 8 turns. It was assumed that After winding 8 turns, the second layer is wound in the opposite direction to the first layer and on top of the first layer starting from the part indicated by 9. For this purpose, part 9 overlaps turn 7 of the first layer. I have to climb on top. Figure 2 is a side view (end view) of what is shown in Figure 1.
In the conventional winding method, the winding roll runs over the turn 7 at the portion shown at 9, so that it is suddenly bent outward in the direction of increasing the winding diameter. FIG. 6 is a perspective view showing another conventional example in which a coil is configured in a spiral shape, and FIG. 7 is an end view thereof, with two rows on the left and right, with the central part 21 of the coil conductor as a transition part. Spiral coils 22 and 23 are formed in opposite directions and are arranged in parallel in the axial direction to form a multilayer heating coil. In this case, each coil conductor must run onto the transition portion 21 near the end of winding of the first layer of each row 22, 23. In both of the above two conventional examples, from the first layer to the second layer
When the conductor runs over the layer, the corners of the conductor cross each other, creating a large stress and causing extremely poor insulation at the corners. This phenomenon is not observed in conductors with a round cross section. [Purpose of the invention] The object of this invention is to provide a multilayer induction heating coil made of a hollow conductor with a square cross section, in which there is no risk of damage to the insulator at the corners of the riding part. [Summary of the invention] In order to achieve the above-mentioned object, this invention has a multilayer induction heating coil formed of a hollow coil conductor with a rectangular conductor shape. A guide part that supports the conductor is attached to the part where the winding start part of the upper second layer rides on, and the shape of this guide part has the same thickness and width as the conductor at the transition start position, and the same width toward the front. The coil is configured as a multi-layer induction heating coil characterized in that the height gradually decreases at the top and the width gradually decreases at the same height toward the rear. The guide portion has a shape approximating an elongated tetrahedron. [Embodiments of the invention] Examples illustrating the invention will be described in detail below. FIG. 3 is a front view showing one embodiment of the heating coil according to this invention, and for convenience of explanation, the spirally wound coil as shown in FIG. It was supposed to be bent and rolled at the position shown. The same result can be obtained even if it is wound spirally as shown in Fig. 1. 5, 6, 7, and 8 are the numbers of each turn of the first layer of the first layer of the spirally wound coil, as in FIG. However, unlike Figure 1, Figure 3
In the figure, the height of the second layer is reached at the position indicated by the chain line 10, and the next turn is started from there. Therefore 1
0 is the transition start plane, and 11 is the transition end point. Reference numeral 12 denotes a guide section which is attached to the side surface of the transition section from turn 7 to final turn 8 of the first layer using, for example, adhesive. Its base 13 has the same thickness as the coil conductor and is attached to the side of the part between the dashed lines 10 and 11 of turn 7 (this is the transition part from turn 7 to turn 8) in this case. Time guide part 1
The outer surface 14 of turn 2 is made to coincide with the outer surface of turn 8. The front of the guide portion 12 is an inclined surface 15. FIG. 4 is an end view of the device shown in FIG. 3, and the inclined surface 15 is an inclined surface that becomes thinner toward the front as shown in FIG. is made to stand out. In other words, the shape of the guide portion 12 is such that it has the same thickness and width as the conductor at the transition start position, gradually decreases in height at the same width toward the front, and gradually decreases in width at the same height toward the rear transition end point. It is a shape that approximates an elongated tetrahedron. The end of the winding of the turn 8 is guided by the inclined surface 15 and gradually increases its winding diameter, and when it is wound as the second layer outside the first layer, its inner diameter becomes the second layer. It is made equal to the outer diameter of one layer. Therefore, the winding start 9 of the second layer directly rides on the transition part to the turn 8 of the first layer and is wound on the turn 8 as the first turn of the second layer. It is wound spirally in the opposite direction to the left in the figure. After starting to wind only the first turn of the second layer using the guide portion 12 without making a sharp curvature, no problem occurs because its inner diameter is equal to the outer diameter of the first layer.
Similarly, at the end of the left winding of the second layer, a guide part equivalent to the guide part 12 can be provided, and the third layer can be wound.
When transitioning from the third layer to the fourth layer or from the fourth layer to the fifth layer, by similarly providing a guide portion that is equal to the guide portion 12 , sudden curvature of the coil conductor at the transition portion is avoided. be able to. Information department
When the guide portion 12 is formed of a conductor, a slit S may be provided in the guide portion 12 as shown in FIG. 5 in order to reduce eddy current loss. FIG. 8 is a partial front view showing an embodiment in which this invention is applied to the spirally wound multilayer coil shown in FIG. 6, which is another prior art example, and FIG. 9 is a partial end view thereof. 34 and 37 are equivalent to the guide portions 12 in FIGS. 3 and 4, respectively, and the coil conductor 32
When the first layer has almost finished being wound, by continuing to wind it along the inclined surface 36, it is gradually bent outward and transitions to the second layer with a gentle degree of curvature. The guide portions 34 and 37 can be made of conductors provided with slits S' to reduce eddy current loss, as shown in FIG. [Effects of the invention] As described above, according to this invention, since the structure is as described in the main points of the invention, manufacturing is facilitated, and the insulating material at the corners of the coil conductor is reduced at the transition portion of each layer. This has the effect of eliminating the risk of damage.

[Brief explanation of the drawing]

Figure 1 shows the first example of a conventional multilayer spiral wound coil.
A perspective view showing the transition from one layer to the second layer, FIG. 2 is a side view (end view) of FIG. 1, and FIG. 3 is a partial front view showing one embodiment of the coil conductor according to this invention. 4 is an end view of FIG. 3, FIG. 5 is a front view showing an example of the guide section, FIG. 6 is a partial perspective view showing a conventional spiral heating coil, and FIG.
8 is a partial front view of another embodiment of the invention, FIG. 9 is an end view of FIG. 8, and FIG. 10 is a front view showing one example of the guide section. 5, 6, 7, 8...Each turn of the first layer of the spirally wound coil, 9...Transition part from the first layer to the second layer of the coil conductor, 12 ...Guide part, 13...Each of the guide part Base, 15... Inclined surface, 31... Center part of coil conductor (transition part), 32, 33... Coil conductor, 3
4, 37 ... Guide part, 35, 38... Base of guide part, 36, 39... Inclined surface.

Claims (1)

[Scope of utility model registration request] In a multilayer induction heating coil formed of a hollow coil conductor with a rectangular conductor shape,
A guide part that supports the conductor is attached to the part where the winding end part of the first layer runs over the winding start part of the second layer above it, and the shape of this guide part is such that the cross section has the same thickness and width as the conductor at the transition start position. 1. A multilayer induction heating coil having a shape in which the height gradually decreases at the same width toward the front, and the width gradually decreases at the same height toward the rear.