JPH06105648B2 - Coaxial rotary transformer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coaxial rotary transformer that can be used in video tape recorders and the like.

Conventional technology Conventionally, the fixed side of this type of coaxial rotary transformer is
It had the configuration shown in FIG.

FIG. 4 is a side view of a fixed side of a conventional coaxial rotary transformer. An outer peripheral groove 1a and a vertical groove 1b are provided on the outer peripheral surface of the cylindrical core 1 made of ferrite. In the outer peripheral groove 1a, the signal coil 2 of the channel 1, the signal coil 3 of the channel 2 and the short ring 4 are wound in different outer peripheral grooves 1a. The short ring 4 is a bare tinned copper wire, and the signal coils 2 and 3 are polyurethane copper wires.
The cylindrical core 1 is attached and fixed to the terminal plate 5, and the terminal 6 is planted.

Lead wires at the beginning and end of winding of the signal coils 2 and 3 pass through the vertical groove 1b and are connected to the terminal 6. The connecting portion 4a of the short ring 4 is folded and housed in the vertical groove 1b.

Problems to be Solved by the Invention The short ring configured as described above requires a large number of man-hours in manufacturing and has a risk of affecting the reliability of the product. The reason is as follows.

This will be described with reference to a partial side view of the product in the connecting step at the beginning and end of winding of the short ring 4 shown in FIG.

After the winding and wiring of the signal coil 2 are completed, the twisted portion 4b of the short ring 4 winds the tinned copper wire around the outer peripheral groove 1a of the cylindrical core 1 for one turn, and then starts and ends the winding. Twist together. Then, the cylindrical core 1 is cut in a direction perpendicular to the outer periphery with a size larger than the outer diameter and having a margin. After this, soldering is performed up to the base of the twisted portion 4b.

Next, when the twisted portion 4b is previously folded and stored in the vertical groove 1b, the twisted portion 4b is cut to a size such that it does not come into contact with the signal coil 2 on the bending direction side, and is bent and stored in the vertical groove 1b.

As described above, the work is complicated, and the bending work of the twisted portion 4b cannot be easily performed when it is housed in the vertical groove 1b due to the elasticity of the tinned copper wire. Further, since the work is performed in a small dimension, the workability is poor and the number of work steps is large. In terms of reliability, if soldering at the twisted portion 4b is not done securely to the root, when cutting and removing unnecessary parts at the tip, the unsoldered twisted portion 4b remains and the connection is complete. However, there is a risk that the electrical characteristics will become unstable. In addition, a tinned copper wire is used for connection at the twisted portion 4b because of ease of soldering, but the lead wire 2a at the beginning and end of winding of the signal coil 2 passing through the vertical groove 1b is pressed down to form the cylindrical core 1 Since the signal coil is wound so as not to protrude from the outer periphery of the short ring 4 and the short ring 4 is wound after the wiring, the winding portion of the short ring 4 may come into contact with the lead wire 2a. Therefore, the twisted part
When 4b is soldered, heat may be transmitted through the short ring 4, deteriorating the insulating film of the lead wire 2a and shorting both ends of the signal coil 2.

Furthermore, when storing the twisted portion 4b in the vertical groove 1b, the twisted portion 4b
Due to variations in cutting dimensions and work, the signal coil 2
There is a risk of scratching the cutting edge at the tip of the twisted portion 4b due to the contact with, and there is also a risk of adversely affecting the reliability including the above.

The present invention solves such a problem, and an object thereof is to obtain a coaxial rotary transformer which can be easily assembled.

Means for Solving the Problems The technical means of the present invention for solving the above problems is configured such that the conductive material of the short ring is formed of the same member as the signal coil, and the same winding and terminal connection method are used. Is used.

Action The action of this technical means is as follows. By connecting the conductive material of the short ring and the winding with the same material and method as the signal coil for signal transmission, winding and wiring can be performed by the same winding wire machine as the signal coil.

Further, the number of steps can be reduced as compared with the conventional case by connecting the short ring together with other signal coils by solder dipping.

Further, since the connecting work of the connecting portion of the short ring is unnecessary, there is no fear of scratching the signal coil and the reliability is improved.

Embodiment FIG. 1 is a side view of a fixed side of a coaxial rotary transformer according to an embodiment of the present invention.

The cylindrical core 7 is provided with several peripheral grooves 7a and vertical grooves 7b. In each outer peripheral groove 7a, a signal coil 8 for channel 1 and a signal coil 9 for channel 2, and a short ring 10 are provided.
Each is made by winding the same polyurethane copper wire.

A cylindrical core 7 is attached and fixed to the terminal plate 11, and terminals 12 are further implanted. Lead wires at the beginning and end of winding of the signal coil 8 of channel 1, the signal coil 9 of channel 2 and the short ring 10 are wired to the terminal 12 through the vertical groove 7b. However, the lead wires of the signal coils 8 and 9 are
Connect one to each terminal 12 and short ring 10
The lead wire is a dedicated terminal 1 separate from the signal coils 8 and 9.
The beginning and end of the book are connected to the book.

With the above configuration, since the winding of the short ring 10 and the connection to the terminal can be continuously performed in the same equipment as the signal coils 8 and 9, the number of work steps can be reduced, and in terms of reliability,
Since there is no need to connect the short ring 10 separately, and the short ring 10 uses a conductive material with an insulating film,
Even if the lead wires of the signal coils 8 and 9 come into contact with each other, there is no risk of short-circuiting and reliability is improved.

Next, another embodiment of the present invention will be described.

FIG. 2 is a side view of a fixed side coil of a coaxial rotary transformer in another embodiment. In this embodiment, the lead wires at the beginning and end of the short ring 10 are connected to the terminal 12 at the beginning or end of the signal coil 9 and the terminals 12 are shared. This makes it possible to obtain the same effect as that of the above-described embodiment with the conventional number of signal terminals without increasing the number of terminals.

Next, FIG. 3 shows another embodiment of the present invention, which is a wiring diagram of the fixed side coil of the coaxial rotary transformer, in which the winding start and the winding end of the short ring 10 are either the winding start or the winding end of the signal coil 8. The terminal shared with the winding end terminal is grounded.
As a result, it is possible to prevent unwanted noise and crosstalk signal components from the signal coils 9 of other channels from entering the signal coil 8 from the short ring 10.

As described above, according to the present invention, the short ring and the signal coil are made of the same conductive material, and the short ring and the signal coil are continuously provided in the same equipment by using the same winding and connection method. Therefore, the number of manufacturing steps can be reduced and the manufacturing cost can be reduced.

Furthermore, since twisting and soldering of the short ring and cutting and bending work are not required, there is no risk of scratching the signal coil. Further, since the conductive material of the short ring uses the conductive material having the same insulating film as that of the signal coil, there is no risk of short-circuiting even if it comes into contact with the signal coil, and the reliability is improved.

In the future, video tape recorders will tend to have high image quality as the standard, which increases the number of coaxial rotary transformer channels, which in turn increases the number of short rings. Become.

[Brief description of drawings]

FIG. 1 is a side view of a fixed side coil of a coaxial rotary transformer according to an embodiment of the present invention, FIG. 2 is a side view of another embodiment of the present invention, and FIG. 3 is a side view of another embodiment of the present invention. The wiring diagram of the fixed side coil, FIGS. 4 and 5 are a side view and an enlarged view of a main part of a conventional coaxial rotary transformer. 7 ... Cylindrical core, 8, 9 ... Signal coil, 10 ... Short ring, 11 ... Terminal board, 12 ... Terminal.

Claims (3)

[Claims] 1. A conductive material for at least one of a fixed ring and a rotating side of a cylindrical core is formed of the same member as a signal coil, and two lead wires at a winding start and a winding end are provided as one terminal. A coaxial rotary transformer that is connected to and used as a short ring. 2. A coaxial rotary according to claim 1, wherein the two lead wires of the winding start and the winding end of the short ring are connected to one terminal of the winding start or the winding end of one signal coil. Trance. 3. The coaxial rotary transformer according to claim 1, wherein the terminal of the signal coil connected to the lead wire of the short ring is grounded.