EP0038883A1

EP0038883A1 - Covered coil, process for manufacturing the same, and device for manufacturing the same

Info

Publication number: EP0038883A1
Application number: EP80301335A
Authority: EP
Inventors: Toshiro Hatanaka
Original assignee: Takachiho Electric Co Ltd
Current assignee: Takachiho Electric Co Ltd
Priority date: 1980-04-24
Filing date: 1980-04-24
Publication date: 1981-11-04

Abstract

covered coil comprises a loop-shaped insulating tube (1) having a given length and diameter, and a coil formed by winding an insulated wire (2) through the loop-shaped insulating tube by a given number of turns, with inlet and outlet terminal sections (2a,2b) of the insulated wire, in the gap between the open ends of the tube (1). The tube (1) provides insulation and protection for the coil.

The coil is made by first arranging a wire-shaped guide in the tube (1) to which the wire (2) is attached. Rolling-in rollers then rotate the guide with the wire around the tube for a desired number of turns.

The covered coil is for use as a degaussing coil, a stator coil for an underwater motor, a coil for an outdoor antenna, or the like.

Description

This invention relates to a covered coil for use in electrical equipments or telecommunication equipments, and particularly relates to a covered coil which is formed by winding an insulated wire ( hereinafter simply referred to as wire ) through a loop-shaped insulating tube, so that an insulating distance and space distance therearound can readily be selected as required, and can safely be isolated from unfavorable environments, and relates to a process for manufacturing the covered coil and a device for manufacturing the covered coil.
The conventional covered coil, for example, a degaussing coil for use in a color television image receiver is prepared by a process in which an insulating tube is cut longitudinally to be opened in the circumferential direction so as to fit therein a coil formed by winding wire to cover, and after the coil is covered with the cut insulating tube the cut is sealed, or a process in which a coil formed by winding wire is wrapped with an insulating tape.
However, any conventional processes for manufacturing a covered coil have the following drawbacks to be solved.
The conventional processes mentioned above make it very difficult to obtain an insulated coil covered with an insulating material uniform in thickness, and also make it difficult to select as required the insulating distance as well as the space distance therearound.
Further the conventional processes mentioned above are responsible for pinholes formed in sealing the insulated tube cut as above.
Therefore, the conventional covered coil is very difficult to be manufactured due to the complicated processes therefor as mentioned above, which results in a high manufacturing cost.
Moreover, a particular attention must be taken for insulation as to be moistureproof or waterproof with respect to a stator coil for an underwater motor for use in a pump under water or seawater, a coil for an outdoor antenna, or the like.
Therefore, it is desirable to provide a highly reliable covered coil for use in electrical equipments or telecommunication equipments such that the insulating tube used for insulation thereof is uniform in thickness, the insulating distance or the space distance therearound can readily be selected as required, an insulating tube free of defects such as pinholes can be obtained for use, and the coil therein can be completely isolated from unfavorable environments.
It is also desirable to provide a process for manufacturing and a device for manufacturing the highly reliable covered coil mentioned above, in which the covered coil can readily be manufactured at low cost by a simple process.
The present invention provides a covered coil comprising a loop-shaped insulating tube having a given length and diameter, a coil formed by winding an insulated wire through the loop-shaped insulating tube by a given number of turns, an inlet and outlet open tips of the loop-shaped insulating tube, and an inlet and outlet terminal sections of the insulated wire.
The present invention also provides a covered coil comprising a loop-shaped insulating tube having a given length and diameter, a coil formed by winding an insulated wire through a loop-shaped insulating tube by a given number of turns, an inlet and outlet open tips of the loop-shaped insulating tube, and an inlet and outlet terminal sections of the insulated wire, the loop-shaped insulating tube being a loop-shaped composite insulating tube which is composed of a loop-shaped insulating tube A and a loop-shaped insulating tube B which has the same length as that of the loop-shaped insulating tube A and has an inner diameter greater than the outer diameter of the loop-shaped insulating tube A, and into which the loop-shaped insulating tube A is inserted and fitted concentrically therein.
In accordance with the covered coil of the present invention, with the loop-shaped insulating tube uniform in thickness, the insulating distance and space distance therearound can readily be selected as required,and the loop-shaped insulating tube free of defects such as pinholes can be employed directly as an insulating covering for a coil to be insulated.
The present invention also provides a process for manufacturing a covered coil, which process comprises inserting a wire-shaped material of a given length into a loop-shaped insulating tube having a given length and diameter from the inlet open tip thereof to the outlet open tip thereof, detachably fixing the head tip of the wire-shaped material to a tail section of the wire-shaped material at a given point thereof between the tail tip thereof and the inlet open tip of the loop-shaped insulating tube to form a wire-shaped guide having a loop and a tail section thereof, fixing a wire to the tail tip of the wire-shaped guide, and rolling in by the rotating force of a pair of rolling-in rollers provided face to face to each other the wire-shaped guide so formed and the wire fixed thereto in order through the loop-shaped insulating tube to effect winding by a given number of turns, while holding therebetween the wire-shaped guide so formed and the wire fixed thereto by means of a pair of rolling-in rollers.
Thus, the covered coil according to the present invention can readily be manufactured at low cost by a simple process such that the wire is rolled in the loop-shaped insulating tube by the application of the rotation of a pair of rolling-in rollers, and the wire-shaped guide so formed and the wire fixed thereto are rolled in together by means of the rolling-in rollers in oder to make it easy to roll in the wire through the loop-shaped insulating tube.
The present invention further provides a process for manufacturing a covered coil, which process comprises inserting a wire-shaped material of a given length into a loop-shaped insulating tube having a given length and diameter from the inlet open tip thereof to the outlet open tip thereof, detachably fixing the head tip of the wire-shaped material to a tail section of the wire-shaped material at a given point thereof between the tail tip thereof and the inlet open tip of the loop-shaped insulating tube to form a wire-shaped guide having a loop and a tail section thereof, fixing a wire to the tail tip of the wire-shaped guide, and rolling in by the rotating force of a pair of rolling-in rollers provided face to face to each other the wire-shaped guide so formed and the wire fixed thereto in order through the loop-shaped insulating tube to effect winding by a' given number of turns, while holding therebetween the wire-shaped guide so formed and the wire fixed thereto by means of the rolling-in rollers, winding a string for use in binding a winding so formed around the winding, while turning the winding in the peripheral direction through the loop-shaped insulating tube by the application of the rotating force of the rolling-in rollers to bind the winding helically.
The present invention also provides a device for manufacturing a covered coil, which device comprising a means for fixing a loop-shaped, insulating tube, a pair of rolling-in rollers provided face to face to each other for rolling in a wire through the loop-shaped insulating tube, while holding the wire therebetween, a drive means for the rolling-in rollers, a pair of leading-in rollers linked to the rolling-in rollers and for making uniform the tension applied to the wire by the rolling-in rollers, and a pair of counter rollers for counting the number of turns of winding from the total length of the wire lead therein.
In accordance with the device for manufacturing the covered coil of the present invention, the tension applied to the wire by the rolling-in rollers can be set at a low and uniform value to maintain the rolling-in force, and in counting the number of turns of winding, a uniform tension applied to the wire and the counter rollers combine to permit displaying the number of turns of winding, setting a given number of turns of winding, and stopping the operation for counting.
Figures 1 and 2 show one embodiment of the present invention, and Figure 1 is a perspective view of a degaussing coil according to the present invention, and Figure 2 is an explanatory view of a process and device for manufacturing a covered coil according to the present invention.
Figure 1 shows a degaussing coil as an example of the present invention. In Figure 1, an enameled wire or insulated wire 2 is rolled in to form a loop therein a given number of times through a loop-shaped insulating tube 1 having a uniform wall thickness, the inlet and outlet terminal sections 2a, 2b of the insulated wire 2 are covered with a pair of inlet and outlet small insulating tubes 3a, 3b respectively, and one open tip of the small insulating tube sealed to be insulated by heat bonding or the like integrally to the open tip of the loop-shaped insulating tube.
Thus, the covered coil with a insulating covering uniform in thickness can be obtained, and the insulating distance as well as the space distance therearound can readily be selected as required, which results in making it possible to manufacture a highly reliable covered coil.
The loop-shaped insulating tube having a given length and diameter of the present invention should be construed to include a loop-shaped composite insulating tube.
For example, a highly reliable improved degaussing coil with a doubly insulated coil may be obtained by rolling in a wire through a loop-shaped composite insulating tube which is composed of a loop-shaped insulating tube A and a loop-shaped insulating tube B which has the same length as that of the loop-shaped insulating tube A and has an inner diameter greater than the outer diameter of the loop-shaped insulating tube A, and into which the loop-shaped insulating tube A is inserted and fitted therein concentrically.
Thus, material, wall thickness, shape and dimension for the loop-shaped insulating tubes A and B can be arbitrarily selected as required, which makes it very easy to design and manufacture a doubly insulated coil.
With such a covered coil that the covered coil is obtained by winding a wire through a loop-shaped heat shrinkable plastic tube as a loop-shaped insulating tube used or as an inner loop-shaped insulating tube for the loop-shaped 'composite insulating tube mentioned above, and thereafter heating the covered coil in an oven or the like for heat shrinking the loop-shaped heat shrinkable plastic tube, an improved covered coil having an insulating covering or double insulating covering uniform in thickness, and having a well arranged coil as above and consequently less vibration humming can be obtained advantageously.
The loop-shaped insulating tube may cover two or more coils, or may cover one coil having one or more intermediate taps.
The process for manufacturing the covered coil and the device therefor according to the present invention will be further illustrated with reference to Figure 2.
In Figure 2, a wire-shaped material of a given length is inserted into a loop-shaped insulating tube 1 uniform in thickness and having a given length and diameter from the inlet open tip thereof to the outlet open tip thereof. The head tip of the wire-shaped material is fixed to the tail section of the wire-shaped material at a given point thereof between the tail tip thereof and the inlet open tip of the loop-shaped insulating tube 1 to form a wire-shaped guide composed of a loop and a tail section thereof.
The wire-shaped material is formed into a loop through the loop-shaped insulating tube as mentioned above in order to make wire length uniform for each turn of a coil, and prevent the wire rolled in from being broken or bent. Therefore, the wire-shaped material should have an appropriate elasticity and stiffness.
In the case where the wire used for winding is suitable as a wire-shaped material, the wire may be used as the wire-shaped material, where a loop may be formed by soldering to fix, and after a coil is formed a guide section of the wire may be removed.
A wire-shaped material made of an insulating material such as plastics has such an advantage that the material used as a guide may be allowed to remain in the coil after the coil is formed.
Thereafter, the loop-shaped insulating tube 1 is fixed in place along a guide groove 5 formed in a workbench 4, and a wire is fixed to the tail tip of the wire-shaped guide so formed. The wire-shaped guide so formed and the wire fixed thereto are rolled in through a loop-shaped insulating tube 1 by the application of a rolling-in roller 7 rotated by a driving source such as a motor and a rolling-in roller 8 linked to the roller 7 to rotate. When rolled in, the wire 2 is lead in to the rolling-in rollers 7,8 by means of a pair of leading-in rollers 9,9¹ linked to the rolling-in rollers 7,8 to rotate so that an unfavorable tension may not be applied to the wire 2,-which makes it possible to keep the rolling-in force of the rolling-in rollers 7,8 at an appropriately high level to be rolled in easily. In forming a winding as mentioned above, a number of times of winding, that is, a number of turns is counted by means of a pair of counter rollers 10, 10' located between the rolling-in rollers 7,8 and a pair of leading-in rollers 9,9', and the value of a number of turns of winding is displayed by means of a winding number display counter 11. The winding number display counter 11 is provided with a memory storage attached thereto such that a predetermined number of turns of winding is set, and when the set number is reached the operation thereof is stopped by means of a driving source 6. A uniform tension applied to the wire by means of the leading-in rollers 9,9' makes it possible for the counter rollers 10,10' to count accurately the number of turns of winding.
After the completion of the winding procedure as mentioned above, the resultant winding is bound to arrange the coil covered by the loop-shaped insulating tube 1. That is, after the completion of the winding procedure, the wire is cut to length to form an inlet terminal section thereof. A string for use in binding set in a winding binding head 13 is rolled a few times around the coil to bind it and to fix a head section of the string to the coil, and then while the coil is turning in the peripheral direction through the loop-shaped insulating tube 1 by means of the rolling-in rollers 7,8, a winding binding mechanism 12 is operated to bind helically the coil automatically by means of the winding binding head 13. After the binding procedure is completed, a tail section of the string for use in binding is fixed to the coil. Thus, the coil covered by the loop-shaped insulating tube 1 is bound and arranged as mentioned above so that a humming due to vibration may be reduced. Besides binding the coil as mentioned above, the coil may be arranged by covering tightly the coil with heat shrinkable plastics as mentioned above, or by encapsulating and setting therein an encapsulant such as an elastic oil-modified polyester varnish or cold-setting silicone rubber. The method of encapsulating and setting the elastic oil-modified polyester varnish or cold-setting silicone rubber has such advantages that the loop-shaped insulating tube 1 covering the coil can be employed directly as a mold for encapsulation, and after encapsulating, the encapsulant can be set to form easily a coil having a specified shape as required.
After the completion of the binding procedure mentioned above, the loop-shaped insulated coil is removed from the guide groove 5. The wire fixed to the tail tip of the wire-shaped guide is removed, and a pair of small insulating tubes 3a,3b at least enough to cover the wire are inserted into the inlet and outlet terminal sections 2a,2b of the wire 2 rolled in respectively. Then one open tip of the small insulating tube is sealed to be insulated integrally to the open tip of the loop-shaped insulating tube 1 to obtain a covered coil as a final product.
The coil so formed can not be covered entirely with the loop-shaped insulating tube due to the rolling-in rollers 7,8 and the winding binding head 13 used.
A large insulating tube having a given length and enough to cover tightly the loop-shaped insulating tube 1 may be fitted thereon before starting the winding procedure mentioned above, and may be fitted over a coil section not to be covered with the loop-shaped insulating tube 1 after the sealing procedure mentioned above is completed by shifting it thereover to seal entirely the uncovered coil section, so that the covered coil may be completely isolated from unfavorable environments.
The rolling-in roller 8 is fitted rotatably to a shaking rod 14 mounted shakably on the workbench 4. Movements of the shaking rod 14 as shown in Figure 2 makes it possible to hold the wire therebetween, or to release the wire from being held simply and easily.
Therefore, in accordance with a process for manufacturing a loop-shaped covered coil and a device for manufacturing the loop-shaped covered coil of the present invention, a loop-shaped covered coil as final product can readily be manufactured at low cost by a simple process without needing highly complicated manufacturing facilities, because the winding procedure is carried out directly in a loop-shaped insulating tube, which makes it unnecessary to seal a cut in an indulating tube as in the conventional covered coil, or to wrap an coil with an insulating tape as in the prior art.
In accordance with the present invention, a. loop-shaped covered coil such as a degaussing coil or the like can readily be manufactured at low cost by a simple process without needing high manufacturing techniques, while a loop-shaped insulating tube used has such a uniform wall thickness that the insulating distance and space distance therearound can readily be selected as required, and the loop-shaped covered coil thus obtained is free from defects such as pinholes on the insulating tube and is isolated safely from unfavorable environments, which results in a highly reliable final product as well.

Claims

1. A covered coil characterised by a loop-shaped insulating tube (1) having a given length and diameter, a coil formed by winding an insulated wire (2) through the loop-shaped insulating tube by a given number of turns, inlet and outlet open tips of the loop-shaped insulating tube, and inlet and outlet terminal sections (2a,2b) of the insulated wire.

2. A covered coil according to claim 1 wherein said loop-shaped insulating tube is a composite loop-shaped insulating tube which is composed of a first loop-shaped insulating tube, and a second loop-shaped insulating tube which has the same length as the first loop-shaped insulating tube and has an inner diameter greater than the outer diameter of the first loop-shaped insulating tube, and into which the first loop-shaped insulating tube is inserted and fitted therein concentrically.

3. A covered coil according to claim 1 or 2, wherein said loop-shaped insulating tube (1) comprises a heat shrinkable plastic tube, said heat shrinkable plastic tube being heat shrinked to arrange a coil covered therewith, or wherein the winding of the coil covered with the loop-shaped insulating tube.is bound helically with a string, or wherein the winding of the coil covered with the loop-shaped insulating tube is arranged by encapsulating an encapsulant into the loop-shaped insulating tube and setting the encapsulant therein.

4. A covered coil according to any one of claims 1 to 3, wherein a coil section not to be covered with the loop-shaped insulating tube (1) between the inlet and outlet open tips thereof is covered with such an insulating tube as to cover said coil section entirely.

5. A process for manufacturing a covered coil, characterised by inserting a wire-shaped material of a given length into a'loop-shaped insulating tube (1) having a given length and diameter from the inlet open tip thereof to the outlet open tip thereof, detachably fixing the head tip of the wire-shaped material to a tail section of the wire-shaped material at a given point thereof between the tail tip thereof and the inlet open tip of the loop-shaped insulating tube to form a wire-shaped guide composed of a loop and a tail section thereof, fixing a wire (2) to the tail tip of the wire-shaped guide, and rolling the wire-shaped guide and the wire fixed thereto through the loop-shaped insulating tube to effect winding of a given number of turns, by means of the rotating force of a pair of rolling-in rollers (7,8) provided face to face to each other, between which the wire-shaped guide and the wire are held.

6. A process for manufacturing a covered coil according to claim 5, further including winding string around the winding so formed, while turning the winding in the peripheral direction through the loop-shaped insulating tube by the application of the rotating force of the rolling-in rollers (7,8.), to bind the winding helically.

7. A process for manufacturing a covered coil according to claim 5 or claim 6, wherein said wire-shaped material is made of an insulating material.

8. A process for manufacturing a covered coil according to claim 5 or claim 6, wherein said insulated wire (2) is used as the wire-shaped material, a guide section of the insulated wire being removed after completion of the winding procedure.

9. A process for manufacturing a covered coil according to any one of claims 5 to 8, wherein said loop-shaped insulating tube (1) is a composite loop-shaped insulating tube which is composed of a first loop-shaped insulating tube, and a second loop-shaped insulating tube which has the same length as that of the first loop-shaped insulating tube and has an inner diameter greater than the outer diameter of the first loop-shaped insulating tube, and into which the first loop-shaped insulating tube is inserted and fitted therein concentrically, said first tube being of heat shrinkable plastics material, the process including the step of heating said first tube to shrink it onto the winding formed within it.

10. A device for manufacturing a covered coil, which device comprises a means (5) for fixing a loop-shaped insulating tube (1), a pair of rolling-in rollers (7,8) provided face to face to each other for rolling in a wire (2) through the loop-shaped insulating tube, while holding the wire therebetween, a drive means for the rollinq-in rollers, a pair of leading-in rollers (9,9') .linked to the rolling-in rollers and for making uniform the tension applied to the wire by the rolling-in rollers, and a pair of counter rollers (10,10') for counting the number of turns of.winding from the total length of the wire lead therein.