JP4267951B2 - coil - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coil used for a transformer, a solenoid, a motor, an antenna, and the like, and more specifically, relates to a wound coil that is fixed in a state in which a coil wire is spirally wound around a substrate.
[0002]
[Prior art]
FIG. 2 shows a conventional example of a coil fixed in a state in which a coil wire is spirally wound around a substrate. A coil 20 in FIG. 2 is a coil in which a coil wire such as an enamel wire is fixed to a substrate (not shown), a coil main body 22 in which a coil wire 21 is wound in a spiral shape (spiral shape), and a coil The coil wire 21 has a lead-out portion 23 for connecting an external terminal, which is drawn out linearly from the inner end of the main body 22 to the outside of the coil main body 22. The wire rod of the lead-out portion 23 contacts the wire rod of the coil main body 22 at all cross points 24, and both wire rods intersect at a substantially right angle. The wire material of the coil main body 22 and the wire material of the lead-out portion 23 are fixed to the substrate by receiving pressure from above and below during manufacture (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-273967
[Problems to be solved by the invention]
In the conventional coil 20, the drawn portion 23 is drawn linearly, and the wire rod of the coil main body 22 and the wire rod of the drawn portion 23 intersect at substantially right angles at each cross point 24, so that both wires are in point contact. For this reason, when pressure is applied to the coil body 22 and the lead-out portion 23 from above and below, or external pressure is applied through the substrate, the point contact portion has a very small contact area. A large stress is applied intensively, the wire rod of the coil body 22 and the conductor of the wire rod 23 are deformed, or the insulating layer is crushed, causing a short circuit between the coil rod 22 and the wire rod 23. There was a problem that it was easy.
[0005]
In order to avoid the occurrence of such a problem, for example, as shown in FIG. 3, a groove 26 for accommodating the lead-out portion 23 is formed in the substrate 25 for fixing the coil body 22 and the lead-out portion 23 in order to avoid pressure applied during manufacture. The method of providing may be employ | adopted. In addition, as shown in FIG. 4, a method of inserting an insulating sheet 27 between the coil body 22 and the lead portion 23 may be employed. However, in these methods, the manufacturing process of the coil 20 becomes complicated, and a new problem of increasing the cost arises.
[0006]
The cross point 24 where the wire rod of the coil body 22 and the wire rod of the lead-out portion 23 contact is an electrical weak point of the coil 20, and it is desirable that the distance between the weak points is long. However, in the conventional coil 20, since the lead-out portion 23 is drawn out linearly, the cross points 24 are aligned on a straight line with the line pitch of the coil body 22 as a pitch, and the distance between the cross points 24 is short. Therefore, also in this respect, there is a problem that a short circuit is likely to occur between the wire bodies of the coil body 22 and the lead portion 23.
[0007]
The present invention has been made in view of the above-described circumstances, and is a coil that is fixed in a state in which a coil wire is spirally wound around a substrate, and between the wire of the coil body and the wire of the lead portion. An object of the present invention is to provide a coil that is less likely to cause a short circuit.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention is a coil in which a coil wire is fixed to a substrate with a wiring, and a coil main body in which a coil wire is spirally wound, and a coil wire is disposed on the coil main body. A coil part having a lead-out portion that is drawn out from the inner end to the outside, and the coil wire of the coil body and the coil wire of the lead-out part intersect at a plurality of cross points, and the lead-out part has a curved shape Provided is a coil that is formed.
[0009]
In the coil of the present invention, the lead portion is formed in a curved shape. Therefore, at each cross point, the wire rod of the coil body and the wire rod of the lead-out portion cross each other at an angle, and both wires are in line contact. Therefore, when pressure is applied to the coil body and the lead-out portion, the line contact portion has a larger contact area than point contact, so that the force applied to the contact portion is dispersed and the stress applied per unit area is reduced. Therefore, the wire of the coil body and the conductor of the wire of the lead portion are not deformed or the insulating layer is not crushed or reduced, and a short circuit between the coil body and the wire of the lead portion is less likely to occur.
[0010]
Moreover, in the coil of this invention, since the drawer | drawing-out part is drawn out in curve shape, the distance between the cross points which are an electrical weak point of a coil becomes long compared with the case where it is drawn out linearly. Therefore, also in this respect, a short circuit between the coil main body and the wire of the lead portion is less likely to occur.
[0011]
In the present invention, there is no particular limitation on the curved shape of the lead-out portion, but it is appropriate to use a spiral shape or an arc shape. A spiral is a plane curve that keeps turning around a certain point.
[0012]
In addition, the crossing angle between the coil wire of the coil body and the coil wire of the lead-out portion at each cross point is preferably in the range of 5 to 60 degrees. Here, the crossing angle refers to the smaller one of the angles between the tangent at the cross point of the curve formed by the coil wire of the coil body and the tangent at the cross point of the curve formed by the coil wire of the lead-out portion. If the crossing angle is larger than 60 degrees, the contact area of the wire at the crossing point cannot be increased. Therefore, the stress per unit area applied to this portion is the same as in the case of FIG. The layers may be crushed and the distance between the cross points is also short, which has no effect on the short circuit. When the crossing angle is smaller than 5 degrees, the length of the lead portion becomes too long, which is not economical.
[0013]
In the coil of the present invention, any wire such as enameled wire can be used as the coil wire, and any material such as a synthetic resin substrate can be used as the substrate. Further, as a method of fixing the substrate and the coil wire is bonded by wiring, Ru using a viscous adhesive.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to the following examples. FIG. 1 is a plan view showing an example of a coil according to the present invention. The coil 10 of this example is a coil in which a coil wire is fixed to a substrate (not shown), a coil body 12 in which a coil wire 11 is spirally wound, and a coil wire from the inner end of the coil body 12. 11 has a lead-out portion 13 that is drawn out in a curved shape (in this example, a spiral shape) on the outside of the coil body 12. The wire rod of the lead-out portion 13 intersects with the wire rod of the coil body 12 at all cross points 14 and intersects. Moreover, the crossing angle (alpha) of the wire rod of the coil main body 12 and the wire rod of the drawer | drawing-out part 13 is the range of 5-60 degrees in all the cross points 14. FIG.
[0015]
The coil wire 11 includes a conductor and an insulating layer covering the periphery of the conductor. The coil main body 12 and the lead-out part 13 receive pressure from above and below when the coil is formed and attached to the substrate.
[0016]
The coil 10 of this example is manufactured as follows, for example. A coil body having a conductor diameter of 0.15 mm as a coil wire 11 and having an inner diameter a of 10 mm, an outer diameter b of 30 mm, a line pitch ρ of 1.0 mm, and a number of turns of 10 on the lower substrate. 12 and a lead-out portion 13 drawn out spirally from the inner end of the coil body 12 to the outside of the coil body 12 are formed by wiring (see WO 00/69234). Subsequently, on the lower substrate on which the coil main body 12 and the lead-out portion 13 are formed, the upper substrate is fixed with a vertical pressure of 3.0 kg, and the coil main body 12 and the lead-out portion 13 are sandwiched between the two substrates, The coil 10 is completed.
[0017]
In the coil 10 of this example, since the crossing angle α between the wire rod of the coil body 12 and the wire rod of the lead-out portion 13 at each cross point 14 is within 5 to 60 degrees, the contact area between both wires is large, and the contact The stress applied per unit area in the portion is reduced. Moreover, in the coil 10 of this example, the distance Cn between the adjacent cross points 14 becomes large, and the short circuit between both wire materials can be prevented effectively also in this point. Therefore, the coil 10 of this example effectively suppresses the occurrence of a short circuit at the cross point 14 and realizes a highly reliable coil.
[0018]
Furthermore, the coil 10 of the present example is relatively simple to manufacture without requiring a complicated and costly process such as forming a groove for accommodating the lead portion or providing an insulating tape for preventing a short circuit as in the conventional case. Since the method can suppress the occurrence of a short circuit between the wires, the cost can be reduced.
[0019]
A coil (conventional coil) similar to the coil 10 of the present example except that the coil 10 of the present example described above and the lead-out portion are made linear as in the conventional case is prepared, and a short circuit between the wire members in each coil is produced. The ease of occurrence was investigated. Specifically, the breakdown voltage of each coil was measured. As a result, the conventional coil had an average breakdown voltage of 4.3 kV and a standard deviation of 0.98 kV, whereas the coil 10 of this example had an average breakdown voltage of 5.6 kV and a standard deviation. Was 0.14 kV.
[0020]
As described above, in the coil 10 of this example, the average value of the breakdown voltage is greatly improved as compared with the conventional coil. In addition, the standard deviation of breakdown voltage was greatly reduced, and the variation of breakdown voltage was greatly reduced. Therefore, it can be evaluated that the coil 10 of this example is less likely to cause a short circuit and has higher reliability than the conventional coil.
[0021]
【The invention's effect】
As described above, the coil according to the present invention is less likely to cause a short circuit between the wire of the coil body and the wire of the lead portion.
[Brief description of the drawings]
FIG. 1 is a plan view showing an example of a coil according to the present invention.
FIG. 2 is a plan view showing an example of a conventional coil.
FIG. 3 is a perspective view showing a conventional coil having a groove for accommodating a lead portion.
FIG. 4 is a perspective view showing a conventional coil provided with an insulating tape.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Coil 11 Coil wire 12 Coil body 13 Lead-out part 14 Cross point

Claims (3)

A coil in which a coil wire is fixed on a substrate with a wiring, and has a coil main body in which the coil wire is wound in a spiral shape, and a lead-out portion that draws the coil wire from the inner end of the coil main body to the outside. In the coil in which the coil wire of the coil body and the coil wire of the lead portion intersect at a plurality of cross points, the lead portion is formed in a curved shape.   The coil according to claim 1, wherein the lead-out portion is formed in a spiral shape or an arc shape.   The coil according to claim 1 or 2, wherein the crossing angle between the coil wire of the coil body and the coil wire of the lead portion at the cross point is 5 to 60 degrees.

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