JP2601226Y2 - Flat core for rotary transformer - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary transformer, and more particularly to a flat core for a rotary transformer.

[0002]

2. Description of the Related Art A rotary transformer is used as a means for transmitting an electric signal from a rotary head or a sensor for a rotating body in a video recorder to a circuit in a stationary portion. FIG. 1 is a principle diagram of a rotary transformer, showing a rotary transformer for transmitting a signal from a head of a two-head video recorder as an example. In this figure, the coils 2 and 3 connected to the magnetic head H _1, H ₂ are disposed in the rotor 1 is rotated by the shaft
Acts magnetically with the coils 5 and 6 of the stator 4 disposed opposite to each other via the surface of the rotor 1, and an electric signal from the head is taken out to an external circuit. Thus, the rotary transformer consists of a rotor rotated by a central shaft and a fixed stator arranged opposite to this rotor, and these rotors and stators, as shown in FIG. A concentric coil groove 8 and a radial coil lead-out groove 9 are provided on one surface of the plate core 7, and a coil conductor is disposed in the coil groove. It consists of

[0003]

Conventionally, in this type of ferrite lithographic core for a rotary transformer, after firing, during work such as polishing, or during transportation, the cores collide with each other or collide with a gauge or the like. Cracks 10 and 11 (also referred to as mountain cracks) may occur as shown in FIG. In particular, the outermost tip of the coil drawing groove tends to form a bulge 12 as shown in FIG. 4 (enlarged view of the circle B in FIG. 2) due to the nature of ferrite, and this is the reason for the other core. In many cases, and cracks 10 were generated. In particular, as the number of grooves on the core increases and the number of draw-out grooves increases, the corners increase and the possibility increases. The present invention is intended to prevent the occurrence of cracks at the outermost end of the coil extraction groove.

[0004]

In the flat core for a rotary transformer according to the present invention, the radius of the core near the outermost end of the coil lead wire groove existing in the radial direction is gradually reduced toward the lead groove. By forming a concave portion in this portion, the possibility that the outermost corner of the drawing groove violently collides with another member to reduce the possibility of cracking in this portion is reduced.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 5 and 6 are a plan view and a cross-sectional view of one embodiment of the present invention, respectively.
Flat core 17 for rotary transformer made of ferrite
Are a plurality of coil grooves 1 for inserting coil conductors.
8 and a groove 19 for drawing out the coil. If the rotary transformer is used in connection with a rotary head, for example for a video recorder, the number of grooves can be increased or decreased arbitrarily depending on the number of heads used. According to the present invention, the diameter of the coil is gradually reduced in the vicinity of the outermost end of the coil drawing groove 19, and a recess or depression is formed.
The shape of the recess is shown in more detail in FIG. 7 (an enlarged view of the circled portion C in FIG. 5) and is indicated at 20. Note that it is preferable that the corner formed by the inclined portion and the peripheral surface, the corner formed by the inclined portion, and the coil extraction groove be rounded as much as possible.

FIG. 8 shows a state in which the flat core of the present invention collides with, for example, the peripheral surface of the same kind of flat core.
The outermost tip of the draw-out groove of the present invention has a large possibility of cracking because the corners do not directly collide with other members and the recesses hit the other members without much impact so as to accept them. It will be understood that it is reduced to.

[0007]

As described above in detail, according to the present invention, the peripheral edge caused by collision between cores or collision with other members such as a gauge during work or transportation of the product of the flat core for a rotary transformer. The possibility of occurrence of cracks in the part, especially near the outermost tip of the coil drawing groove, is greatly reduced, and the yield of the product is improved. Very big.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a rotary transformer.

FIG. 2 is a plan view of a conventional flat core for a rotary transformer showing the occurrence of cracks.

FIG. 3 is a partially enlarged view of the vicinity of the outermost distal end of a lead wire groove of the flat plate core shown in FIG. 2;

FIG. 4 is a partially enlarged view showing a mode of a tendency of deformation occurring at an outermost end portion of a lead wire groove of the flat plate core shown in FIG. 2;

FIG. 5 is a plan view of the embodiment of the flat core for a rotary transformer according to the present invention;

FIG. 6 is a sectional view of the flat core of the present invention shown in FIG. 5;

FIG. 7 is a partially enlarged view of the flat plate core showing a recess or depression of the flat plate core of the present invention.

FIG. 8 is a diagram showing a state of collision of the planographic core of the present invention with another core.

[Explanation of symbols]

 17 Flat core 18 Coil groove 19 Coil lead-out groove 20 Depression or depression

Claims (1)

(57) [Scope of request for utility model registration] In a flat core for a rotary transformer having a concentric coil groove and a coil extraction groove in a radial direction and having no step in the outer peripheral portion, a diameter of an outer peripheral surface near an outermost end portion of the coil extraction groove. a reduced gradually, slow in the part
A flat core for a rotary transformer, wherein a shallow concave portion or dent is formed.