JP3056363U - Rotary transformer - Google Patents

Abstract

(57) [Problem] To provide a rotary transformer which realizes a structure for preventing a magnetic core from cracking and preventing a coil from floating. SOLUTION: A step for preventing cracks is formed on the outer peripheral portion of a disc-shaped core 1 having a concentric coil groove 2 on which an annular coil 20 is mounted and a coil extracting groove 5 from which a lead 21 of the annular coil 20 is led out. A part 4 is formed, and the crack preventing step is formed along the coil drawing groove 5 from the end of the crack preventing step 4 reaching the coil drawing groove 5 toward the outermost coil groove 2. An extension 4a of the step portion 4 is formed, and a protrusion lower than the bank 3 outside the outermost coil groove 2 during a period from the tip of the extension 4a to the outermost coil groove 2. This is a configuration in which the unit 10 is provided.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a flat type rotary transformer used for a VTR or the like, and more particularly to a rotary transformer having a structure for preventing a core from cracking and a coil from floating.

[0002]

[Prior art]

 Conventionally, the width of the outermost bank of a disk-shaped core used in a flat-type rotary transformer has tended to be narrow in order to satisfy electrical characteristics. Cracks tend to concentrate on the outermost bank due to contact with jigs and tools. A structure in which a step portion for preventing cracks is provided on the outermost periphery in order to prevent the occurrence of cracks is disclosed.

FIG. 6 shows a conventional example of a disk-shaped core for a rotary transformer provided with a step portion for preventing cracks at the outermost periphery. Reference numeral 1 denotes a disk-shaped magnetic core such as sintered ferrite, and a concentric coil. A groove 2 is formed. Both sides of the coil groove 2 are annular banks (projections) 3, and a step portion 4 for preventing cracks, which is one step lower, is formed on the periphery of the outermost bank 3. . Note that a coil extraction groove 5 is formed in the radial direction of the core 1.

In Japanese Utility Model Application Laid-Open No. 6-34217, the crack preventing step is provided on the outer peripheral portion of the core, and the crack preventing step on the outer peripheral portion of the core is arranged along the coil drawing groove. There is also disclosed a structure extending to the groove. That is, as in the other conventional example shown in FIG. 7, a crack preventing step 4 is formed on the peripheral edge of the outermost bank 3 of the core 1 and the crack preventing step 4 is formed at the end of the coil extraction groove 5. The extension 4a of the step portion 4 for preventing cracks is formed along the coil lead-out groove 5 from the portion where the portion reaches the portion to the outermost coil groove 2.

[0005]

However, in the conventional example shown in FIG. 6, since the end 3a of the bank 3 facing the coil extraction groove 5 remains sharp, there is a possibility that this portion may be chipped off. Yes, it is incomplete as a crack countermeasure. On the other hand, in the other conventional example of FIG. 7 (Japanese Utility Model Laid-Open No. Hei 6-34217), the cracks of the conventional example of FIG. 6 can be prevented, but as shown in the phantom line of FIG. There is a danger that the coil 20 mounted on the coil groove 2 will float on the extension 4a of the step 4 for preventing cracks provided at the end of the outermost bank. Also, when soldering the coil terminal to a tape head, a board, or the like, since the coil lead wire 21 is moved at all, there is a problem that the lead wire portion of the coil runs over the step at the end of the bank. easy.

[0006] In view of the above problems, an object of the present invention is to provide a rotary transformer that realizes a structure for preventing core cracking and coil floating.

[0007] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides an outer peripheral portion of a disc-shaped core having a concentric coil groove on which an annular coil is mounted and a coil lead-out groove leading out a lead wire of the annular coil. A rotary transformer having a step portion for preventing cracks formed on the rotary member, the end portion of the step portion for preventing cracks extending from the end reaching the groove for coil drawing, and extending along the groove for coil drawing toward the outermost coil groove. Forming an extension of the step portion for preventing cracks, and between the tip of the extension and the outermost coil groove, a projection lower than the bank portion outside the outermost coil groove. It is characterized by having

In the rotary transformer, it is preferable that a chamfer is formed on an outer peripheral end of the core of the coil extraction groove.

[0010] By using the core for the rotary transformer having the structure as described above, the effect of preventing cracks and improving the strength of the mold and the positioning of the coil lead wire when mounting the coil in the coil groove of the core become easy. It is easy to fit in the coil groove. Also, the floating of the lead wire is eliminated, and the assembly yield is improved.

[0011]

[Embodiment of the invention]

 Hereinafter, embodiments of the rotary transformer according to the present invention will be described with reference to the drawings.

FIG. 1 is an embodiment of the present invention and is a plan view showing the structure of one side of a rotary transformer, FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1, FIG. FIG. 4 is a sectional view of the core of the same part. In these figures, reference numeral 1 denotes a disk-shaped magnetic core such as sintered ferrite, and a plurality of coil grooves 2 are formed concentrically. On both sides of the coil groove 2, an annular bank portion (projection portion) 3 is formed, and on the outer peripheral portion (peripheral portion) of the outermost bank portion 3, a step portion 4 for preventing cracks having a lower height is formed. Have been. A plurality of coil extraction grooves 5 are formed in the radial direction of the core 1. The crack preventing step 4 extends along the coil extracting groove 5 from the end where the crack preventing step 4 reaches the end of the coil extracting groove 5 to the vicinity of the outermost coil groove 2. A protruding portion 10 lower than the bank portion 3 (the upper surface of the core) outside the outermost circumferential coil groove 2 is formed between the distal end of the extending portion 4a and the outermost coil groove 2. It is formed. As shown in the enlarged sectional view of FIG. 4, the extension 4 a of the step portion 4 for preventing cracks is connected to the upper end surface 11 of the projection 10 by an inclined surface 12. Further, a tapered portion 6 is formed on a ridge portion of the bank portion 3 inside the outermost coil groove 2 and in contact with the coil extraction groove 5, and a chamfer is formed on an end portion of the coil extraction groove 5 on the outer peripheral side of the core. 7, the stepped portion 4 of the core outer peripheral portion, the extended portion 4a of the stepped portion 4, and the convex portion 10 serve as components for preventing the core 1 from cracking.

An annular coil 20 is placed in each coil groove 2 (however, the inner coil is not shown in FIGS. 1 and 3), and the protrusion 10 is formed with a lead wire 21 of the coil 20. The guide serves as a guide for preventing the coil 1 from being protruded from the coil extracting groove when the coil 1 is stored in the coil extracting groove 5 and pulled out of the core 1.

FIGS. 1 and 2 show one structure of a regular rotary transformer. To construct the transformer, the structures shown in FIGS. 1 and 2 are concentrically arranged as shown in FIG. To face.

According to this embodiment, the following effects can be obtained.

(1) Providing the disc-shaped magnetic core 1 made of sintered ferrite or the like with the crack preventing step 4 and the extension 4a thereof has the effect of preventing the core from cracking and improving the mold strength. In addition to the fact that the protrusion 10 is provided, when the annular coil 20 is mounted on the core 1, the positioning of the coil lead wire 21 is facilitated, and the coil 20 is placed in the coil groove 2 and the lead wire 21. In the coil extraction groove 5. In addition, the lifting of the lead wire 21 is eliminated, and the assembly yield is improved.

(2) The extension 4 a of the step portion 4 for preventing cracks is connected to the upper end surface 11 of the protrusion 10 by an inclined surface 12, so that the protrusion 10 itself can be prevented from being chipped.

(3) Since the chamfering 7 is formed on the outer peripheral end of the core of the coil extraction groove 5, it is possible to prevent the portion where the coil extraction groove 5 is open toward the outer periphery of the core 1 from being chipped. .

(4) Since the taper 6 is applied to the ridge portion of the bank portion 3 inside the coil groove 2 on the outermost periphery, which is in contact with the coil extraction groove 5, the ridge portion of the bank portion 3 inside the coil groove is not chipped. Can be prevented.

The number of coil grooves and coil lead-out grooves can be appropriately increased or decreased according to the application.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0022]

[Effect of the invention]

 As described above, according to the present invention, it is possible to realize a rotary transformer that minimizes the occurrence of cracks in the core, prevents the coil lead wires from floating, and improves the assembly yield.

[Brief description of the drawings]

FIG. 1 is a plan view showing a structure of one side of a rotary transformer according to an embodiment of the present invention.

FIG. 2 is a front sectional view taken along the line II-II of FIG.

FIG. 3 is a partial perspective view of an outer peripheral side of a core.

FIG. 4 is a sectional view of the same part.

FIG. 5 is a front sectional view showing a normal rotary transformer configuration in which a pair of structures shown in FIGS. 1 and 2 are arranged to face each other.

FIG. 6 is a partial perspective view showing a conventional example of a rotary transformer.

FIG. 7 is a partial perspective view showing another conventional example of a rotary transformer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc-shaped magnetic core 2 Coil groove 3 Bank part 4 Crack prevention step part 4a Extension part 5 Coil extraction groove 6 Taper 7 Chamfer 10 Convex part 11 Top end surface 12 Inclined surface 20 Coil 21 Lead wire

Claims (2)

[Utility model registration claims] A step for preventing cracks is formed on an outer peripheral portion of a disc-shaped core having a concentric coil groove on which an annular coil is mounted and a coil extraction groove for leading out a lead line of the annular coil. A rotary transformer, wherein an extension of the crack preventing step portion extends along the coil extracting groove from an end of the crack preventing step portion that has reached the coil drawing groove toward an outermost coil groove. And a protrusion lower than a bank portion outside the outermost coil groove is provided between the tip of the extension portion and the outermost coil groove. . 2. The rotary transformer according to claim 1, wherein the outer periphery of the core of the coil drawing groove is chamfered.