JPH0927428A - Rotary transformer and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the turn of a rotor side winding in a rotary transformer substantially one turn and provide a rotary transformer of extremely easy handling of a coil including mounting thereof on a core. SOLUTION: After a line material 15 is wound for a plurality of turns and both ends thereof are made extraction lines 16, a part of a coil 14 is dipped in a solder dip bath and a winding part of the coil 14 is connected electrically. Thereafter, the coil 14 is mounted on a rotor side core 11, a winding part is inserted to a ring-like groove 12 and the extraction line 16 is inserted to an extraction groove 13. Then, the line material 15 positioned between both extraction lines 16 is cut inside the ring-like groove 12 and the coil 14 is made a one-turn-coil electrically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary transformer suitable for use in a rotary head provided in a VTR, a DAT or the like, and a manufacturing method thereof, and more particularly to a coil mounted on a rotor side core of the rotary transformer.

[0002]

2. Description of the Related Art In a VTR, a DAT, etc., a recording band is wider and a recording wavelength is very smaller than that of a general audio cassette tape recorder. A method of mounting a head on a rotating cylinder and performing high-speed scanning while rotating the head is widely used for the recording medium thus obtained.
A rotary transformer is generally used to exchange signals with the rotating head.

An example of a conventional rotary transformer will be described with reference to FIGS. 4 and 5. FIG. 4 is a sectional view showing an example of a conventional rotary transformer, and FIG. 5 is a plan view showing its rotor side. The rotary transformer 1 is mounted in a rotor-side coil 4 mounted in a ring-shaped groove 3 formed in a rotating rotor-side core 2 and a ring-shaped groove 6 formed in a fixed stator-side core 5. It is composed of a stator side coil 7. In such a rotary transformer 1, the number of turns of the stator side coil 7 which is the secondary side coil is set to the booster when the electric signal is transmitted from the rotor side to the stator side. More than 4 turns.

On the other hand, in consideration of cost reduction of a head provided with such a rotary transformer, it is effective to reduce the number of windings of the head and to reduce the winding process of the head, which requires skill. A head having a winding with a reduced number of turns, for example, 6 to 8 turns, has been proposed along the line. In order to achieve matching between the head and the rotary transformer or between the rotary transformer and the head amplifier, the number of turns of the rotor side coil 4 is 1 turn. And the stator coil 7
There is also proposed a rotary transformer in which the number of turns is, for example, 4 turns.

[0005]

However, the wire used for the coil of the rotary transformer is thin, and the one-turn coil as described above has a weak rigidity, is difficult to handle, and is difficult to be attached to the core and is not bonded. There are drawbacks in manufacturing, such as difficulty, and the cost becomes high, and as a result, the effect of reducing the cost of the head is weakened.

The present invention has been made in view of the circumstances of the prior art as described above. A first object of the present invention is to attach the rotor side coil to the core while the number of turns of the coil is substantially one. It is to provide a rotary transformer that is extremely easy to handle.

A second object of the present invention is to provide a method of manufacturing a rotary transformer in which the handling such as mounting on the core is extremely easy and the number of turns is substantially one turn.

[0008]

A first object of the present invention is to provide a coil mounted in a ring-shaped groove of a rotor-side core, and a winding portion formed by winding a plurality of wire rods and leading from the winding portion. A pair of lead wire portions, at least a part of the winding wire portion is electrically connected by soldering or fusing, and the winding wire portion between the lead wire portions is electrically turned by one turn coil. It is achieved by the first means cut so that

A second object of the present invention is to form a winding part by winding a plurality of wire rods, draw out a pair of lead wire parts from the winding part, and then solder at least a part of the winding part. Alternatively, the wire of the winding portion is electrically connected by fusion, and then the winding portion is inserted into a ring-shaped groove formed in the rotor side core, and the lead wire portion is connected to the rotor side core. By a second means in which the wire rod of the winding portion between the lead wire portions is cut to electrically form the winding portion into one turn coil. To be achieved.

[0010]

In the first means, the coil mounted in the ring-shaped groove of the rotor core is composed of a plurality of windings, but at least a part of the winding portion is soldered or Since it is electrically connected and fixed by fusion, the strength of this portion is increased, and by cutting the winding wire located between the pair of lead wire portions, the winding portion is substantially one winding. Will make up the line. Therefore, it is possible to provide a rotary transformer which is significantly improved in handling compared with the conventional one, and it is possible to reduce the manufacturing cost.

Further, in the second means, since a part of the winding part in which the wire is wound a plurality of times is electrically connected and fixed, the strength of the coil can be increased, and in the next step. The coil can be extremely easily inserted into the ring-shaped groove of the rotor-side core. Then, after the coil is thus inserted into the ring-shaped groove, the wire material of the winding portion located between the pair of lead portions is cut, so that the winding portion substantially forms one winding. As a result, a one-turn coil can be realized at a lower cost than before.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a rotor-side coil according to a first embodiment of the present invention together with a core, and a stator-side configuration is the same as that of a conventional one, and therefore illustration and description thereof will be omitted.

As shown in FIG. 1, the rotor-side core 11 is formed with a ring-shaped groove 12 and a drawing-out groove 13 connecting a part of the ring-shaped groove 12 and the outer peripheral surface of the core 11. In the ring-shaped groove 12, the wire 15 of the coil 14 is
A winding part wound by turns is inserted, and both ends of the wire material 15 are lead-out wire parts 16 that are led out to the outside through the lead-out groove 13. A fixed portion 17 is formed on a portion of the wire 15 in the ring-shaped groove 12 by immersing the wire 15 in a solder dip tank (not shown) to electrically connect the wire 15 at that portion. The coil 14 constitutes a substantially one-turn coil in which two wire rods 15 are electrically connected by a fixing portion 17 by cutting a wire rod 15 located between a pair of lead wire portions 16. .

Such a coil 14 can be manufactured according to the manufacturing process shown in FIG. That is, as shown in FIG. 2A, first, the wire 15 is wound two turns to form a winding portion, and both ends of the wire 15 are led out from the winding portion to form a pair of lead wire portions 16. , Then the leader 16
With the upper side facing up, a part of the coil 14 is immersed in a solder dip tank (not shown) to form a fixing portion 17 on a part of the coil 14 as shown in FIG. 2B. Here, the winding portion of the coil 14 is formed by winding the wire 15 for two turns, and since a part of the wire 15 is fixed by soldering, the strength of the coil 14 becomes high. Handling 14 is extremely simple.

Next, as shown in FIG. 2C, after mounting the winding portion of the coil 14 in the ring-shaped groove 12 of the core 11 and the lead wire portion 16 in the lead-out groove 13, respectively, an adhesive or the like is used. Then, the core 11 and the coil 14 are bonded and fixed. Finally, FIG.
(D), the wire 15 located between the lead wire portions 16 is cut in the ring-shaped groove 12. As a result, the winding portion of the coil 14 substantially constitutes a one-turn winding, and a one-turn coil can be realized at a lower cost than before, and the cost of head winding reduction can be easily implemented. it can. In addition, the cutting of the wire 15 is performed by the ring-shaped groove 12
Since it is performed inside, the wire 15 does not come apart due to the cutting, and the cutting operation can be easily performed.

FIG. 3 is a plan view showing the rotor side coil according to the second embodiment of the present invention together with the core, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals.

This embodiment is different from the above-mentioned first embodiment in that the burr 21 generated in the fixing portion 17 of the coil 14 is inserted into the groove 22 connected to the ring-shaped groove 12 formed in the rotor side core 11. The other configurations are basically the same. That is, if a part of the coil 14 is dipped in a solder dip tank to form the fixing portion 17 on the winding portion of the coil 14, a burr 21 may be generated in the fixing portion 17 when the coil 14 is pulled up from the dipping tank. is there. When such a burr 21 occurs, the winding portion of the coil 14 cannot be inserted into the ring-shaped groove 12, so that the burr 21 is removed by cutting or the like in the first embodiment described above.
The coil 14 may be deformed by the force applied in this cutting operation. Therefore, in the second embodiment, when a part of the coil 14 is dipped in a solder dip bath, burrs 21 are generated when soldering is performed under the same conditions, for example, pulling the lead wire portion 16 right above. Focusing on the fact that the location is constant, the location where the burr 21 is generated and the position of the groove 22 of the core 11 are set to coincide with each other. This groove 22 is the coil 1
Although a known groove can be used as the pull-out preliminary groove of No. 4, it may be separately formed at an appropriate position, and in this embodiment, it is formed in a portion facing the pull-out groove 13. This allows
By inserting the burr 21 into the groove 22 when inserting the winding portion of the coil 14 into the ring-shaped groove 12, the winding portion of the coil 14 can be attached to the core 11 without removing the burr 21. it can.

In each of the above-described embodiments, the case of a one-channel head has been described, but it goes without saying that the invention can also be applied to a plurality of channels of heads. Further, in each of the above embodiments, the case where the fixing portion 17 is formed by soldering has been described, but the fixing portion 17 may be formed by another fusing means such as spot welding. Further, in each of the above embodiments, the case where the wire 15 is wound two turns to form the winding part of the coil 14 has been described, but the number of turns of the winding part is set to 3 turns or more depending on the wire diameter of the wire 15. Is also good.

[0019]

As described above, according to the present invention,
The winding part of the coil is formed of a plurality of wire rods, and at least a part of the winding part is electrically connected and fixed by soldering or fusion and is located between the pair of lead wire parts. Since the winding portion is cut, the strength can be increased even though the coil has substantially one turn. Therefore, the coil can be easily handled and the manufacturing cost of the rotary transformer can be reduced. Also, if the wire rod is cut in this groove after inserting the coil before cutting into the ring-shaped groove formed in the rotor-side core, handling when mounting the coil in the groove is extremely easy. Not only that, but the wire does not come apart due to the cutting, and the cutting work can be performed easily.

[Brief description of drawings]

FIG. 1 is a plan view showing a rotor-side coil according to a first embodiment of the present invention together with a core.

FIG. 2 is an explanatory diagram showing a manufacturing process of a rotor side coil in the example.

FIG. 3 is a plan view showing a rotor side coil according to a second embodiment of the present invention together with a core.

FIG. 4 is a sectional view showing an example of a conventional rotary transformer.

FIG. 5 is a plan view showing the rotor-side core.

[Explanation of symbols]

 11 rotor side core 12 ring-shaped groove 13 lead-out groove 14 coil 15 wire rod 16 lead-out wire portion 17 fixed portion 21 burr 22 groove for burr accommodation

Claims (3)

[Claims] 1. A coil mounted in a ring-shaped groove of a rotor-side core has a winding portion around which a plurality of wire rods are wound, and a pair of lead wire portions led out from the winding portion. At least a part of the winding wire portion is electrically connected by soldering or fusing, and the winding wire portion between the lead wire portions is electrically cut so as to form a one-turn coil. And a rotary transformer. 2. The rotary transformer according to claim 1, wherein a groove connected to the ring-shaped groove is formed in the rotor-side core, and a burr generated in the fixing portion is inserted into the groove. 3. A winding part is formed by winding a plurality of wire rods, and a pair of lead wire parts is led out from the winding part, and then at least a part of the winding part is soldered or fused. The wire of the winding portion is electrically connected, and then the winding portion is inserted into the ring-shaped groove formed in the rotor side core, and the lead wire portion is formed on the outer peripheral portion of the rotor side core. Into the drawn-out groove, and then the wire material of the winding portion between the lead-out wire portions is cut to electrically form the winding portion into a one-turn coil. .