JPH0652115U - Coaxial rotary transformer core - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a coaxial rotary transformer core with few cracks and cracks. A coaxial type rotary transformer core in which a rotor core 1 having a coil fixing groove 2b and a lead-out groove 2a and a lead-out groove of a stator core having a lead-out groove and a coil-fixing groove are formed in a substantially semicircular shape.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary transformer core installed inside the cylinder of a VTR, and particularly to the shape of a coaxial rotary transformer core.

[0002]

[Prior art]

 Conventionally, this type of rotary transformer core has a rotor core 5 in which a plurality of extraction grooves 6a and coil fixing grooves 6b are arranged on the cylindrical inner surface of FIG. 3, and a plurality of rotor cores on the cylindrical outer surface of FIG. The stator core 7 provided with the drawing groove 8a and the coil fixing groove 8b are each wound and combined to be used as a rotor transformer. However, such a shape is obtained by powder molding, sintering and grinding. When the drawing groove is in the state of a square groove like the drawing grooves 6a and 8a of FIGS. 3, 4, and 7 during the manufacturing, the powder molding, the sintered body, and the product after processing are handled. In addition, defects such as cracks and cracks occur, and moreover stress concentrates on the corners of the drawing groove during grinding of the outer and inner diameters of the process, and again cracks and cracks occur, resulting in more than 15%. Has the drawback of causing It was.

[0003]

[Problems to be solved by the device]

 In order to solve these drawbacks, the present invention changes the shape of the extraction groove of the coaxial rotary transformer core into a substantially semi-circular shape to make the core strong against external stress. The purpose is to provide a coaxial rotary transformer core that can reduce the power consumption.

[0004]

[Means for Solving the Problems]

 The present invention is characterized in that the plurality of lead-out grooves arranged in the coaxial rotary transformer core are semicircular in shape. That is, the present invention is a coaxial type rotary transformer core in which a plurality of coil fixing coil grooves and a drawing groove for drawing a coil wire are provided on the side surface of a cylindrical ferrite core, and the drawing groove has a cross-sectional shape perpendicular to the drawing direction. It is a coaxial rotary trance core characterized by having a substantially semicircular shape.

[0005]

[Action]

 By forming the draw-out grooves of the multiple coils of the coaxial rotary transformer core in a substantially semi-circular shape, stress and concentration during molding are prevented, and a coaxial rotary transformer core that does not crack or crack is provided. it can.

[0006]

【Example】

1 and 2 show a coaxial rotary transformer core according to the present invention, in which a plurality of coil fixing grooves 2b and a coil wire drawing groove 2a of the present invention are arranged in a rotor core 1, and a stator core 3 is provided. It has a shape in which a plurality of coil fixing grooves 4b and a coil wire drawing groove 4a of the present invention are arranged. By the powder molding, first, the rotor core 1 and the stator core 3 are provided with the lead-out grooves 2a and 4a. This molded body is formed by compressing ferrite powder (containing polyvinyl alcohol). Since it is only for the sake of strength, it is very brittle in terms of strength and difficult to handle, but no cracks or cracks occurred at this stage. Next, when processing the sintered body obtained by sintering, in the conventional shape, upper and lower surface grinding,
Cracks and cracks were generated in 15% or more in each of the outer and inner diameter grinding and the groove grinding (showing the coil fixing grooves 2b and 4b), but in the present invention, an improvement of 5% or less was clearly obtained. The above results show that the semi-circular drawing groove of the present invention has a shape with rounded corners for each of the powder compact which is very brittle in terms of strength and the processing with large initial stress. By so doing, the action of reducing the stress concentration works, and the strength is increased. However, the substantially semi-circular shape of the present invention is not a semi-circle whose radius can be L / 2 when the groove width is L and the groove depth is t in FIG. 5, and is not less than L / 2 (excluding L / 2). It is desirable to have an arc having a radius of 4) and a flat portion of 0.10 mm or more in the groove depth t direction. This is because when the radius of the semicircle is L / 2, it is difficult to fix the coil and pull out the coil wire. Further, although it was carried out also when the lead-out groove 9 as shown in FIG. 6 was triangular, on the contrary, it resulted in one-point stress concentration, and cracks and cracks were generated by 30%, which was not practical. In addition to the coaxial rotary transformer core, the above contents can be applied to the improvement of cracks and cracks in the flat plate type rotary trans core.

[0007]

[Effect of device]

 As described above, by forming the plurality of coil lead-out grooves of the coaxial rotary transformer core in a semi-circular shape, it is possible to suppress cracks and cracking defects of 15% or more to 5% or less. did it.

[Brief description of drawings]

FIG. 1 is a perspective view of a rotor core of the present invention.

FIG. 2 is a perspective view of a stator core of the present invention.

FIG. 3 is a perspective view of a conventional rotor core.

FIG. 4 is a perspective view of a conventional rotor core.

5 is an enlarged plan view of part A in FIG.

FIG. 6 is an enlarged plan view of a V-shaped drawing groove.

FIG. 7 is an enlarged plan view of a conventional B portion.

[Explanation of symbols]

 1,5 Rotor cores 2a, 4a, 6a, 8a, 9 Lead-out grooves 2b, 4b, 6b, 8b Coil fixing grooves 3,7 Stator core

Claims (1)

[Scope of utility model registration request] 1. A coaxial rotary transformer core having a coil groove for fixing a plurality of coils and a lead-out groove for drawing out a coil wire on a side surface of a cylindrical ferrite core.
A coaxial type rotary transformer core having a drawing groove formed in a substantially semicircular shape.