JP2003132736A - Wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economic wire which is used for electric/electronic equipments such as motors wherein a high-frequency current is used, and in which weight-saving and promotion of efficiency of the equipments can be aimed at and effective utilization of the high-frequency current can be aimed at. SOLUTION: This is the wire 1 in which plural layers are provided in the diameter direction, and as for the plural layers, the outer layer is formed by a material having a larger electric conductivity than that of the inner layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire, and more particularly to a wire used in electric / electronic devices such as motors to which high frequency current is applied.

[0002]

2. Description of the Related Art In recent years, electric and electronic devices including motors have been reduced in size and weight. For example, the processing operation / speed of the motor has been increased and the number of poles has been increased accordingly, and the current passed through the wire (winding) wound around the motor has been increased in frequency. Regarding the motor control, for example, when pulse width control (PWM) or inverter control is performed, the winding current used to control the speed of the motor has a high frequency.

At present, copper wires are mainly used as wires used in electric / electronic devices including motors. Copper is characterized by high conductivity and specific gravity. The advantage of high conductivity is that the cross-sectional area of the winding required to pass the same amount of current can be reduced, so when incorporated in electrical equipment, copper wires can be made smaller. Suitable for However, since the copper wire has a large specific gravity, it is not suitable for weight reduction.

Further, a technique of using an aluminum wire as a wire is known, but the conductivity of aluminum is about 62% of copper, which is better than that of other metal materials, and the specific gravity is 1/3 of that of copper. Small and small. In this way, aluminum wire has high conductivity, so it is suitable in terms of weight reduction, but when trying to secure the same electrical resistance as copper wire,
There is an inconvenience that the cross-sectional area becomes large and the winding itself becomes large.

Further, there is known a technique in which a wire is composed of a linear material having a small specific gravity and a large tensile strength and a two-layer material of a conductor material provided on the surface thereof. For example, the linear material is composed of carbon fiber, by coating the outer surface of the carbon fiber with copper which is a conductor material, the specific gravity of the carbon fiber is small,
It is possible to manufacture a wire that is lighter than a copper wire.

When high frequency current is used, the current flows through the copper coating the surface of the carbon fiber,
In addition, since the eddy current loss can be reduced, the current can be effectively used. Therefore, compared with the conventional copper wire, while maintaining the same limiting current density,
It is possible to reduce the weight.

Further, since the carbon fiber having high tensile strength is used, even if the wire is made thinner than the wire made of copper, sufficient tensile strength for winding the coil can be obtained. It is possible to obtain a wire (see Japanese Patent Application Laid-Open No. 5-114311).

[0008]

Generally, when a high frequency current is passed through a winding used in a DC electric motor, if the frequency of the current flowing through the winding increases, the current concentrates near the surface of the winding. Due to the so-called skin effect that flows as a result, a phenomenon occurs in which it becomes more difficult for current to flow closer to the center of the winding.

Therefore, even when a copper wire having a high conductivity is used, the amount of current flowing through the center of the winding is reduced, and the copper wire is not effectively used. for that reason,
The apparent electrical resistance of the windings increased, leading to deterioration of motor characteristics.

Further, a motor armature or other wire using wire is melted in the same furnace as it is without being separated into an iron core and a winding for recycling.
There is a disadvantage that the iron used in the iron core and the copper used in the wire are melted and mixed in the furnace, which significantly deteriorates the material quality of the iron.

Therefore, in order not to deteriorate the quality of the recovered iron, it is necessary to separate the wire from the armature or the like before putting it in the furnace, and it takes time and cost to recycle the wire. There was an inconvenience.

Furthermore, when the wire coated with copper on the surface of the carbon fiber is used in a direct current motor, since a material having high tensile strength but low conductivity is used in the central portion, the wire is The overall electrical resistance increases, which can cause disadvantages. That is, when an overcurrent suddenly flows in the wire, since the core portion has poor conductivity, the load on the outer copper increases, and the allowable current may be exceeded relatively easily. there were.

An object of the present invention is a wire used for electric / electronic equipment such as a motor in which a high frequency current is used. The weight and efficiency of the equipment can be reduced and the high frequency current can be effectively used. It is to provide a wire that can be used and has a large allowable current.

[0014]

According to the wire of claim 1, the above-mentioned problem is a wire having a plurality of layers in a radial direction, the plurality of layers being layers outside the inner layer. Is solved by being formed of a material having higher conductivity.

By providing a plurality of layers in the radial direction and using a material in which the outer layers have a higher conductivity than the inner layer, a wire which can be widely applied from low frequency to high frequency current can be obtained. . That is, when a high frequency current is applied, the current is distributed around the outer good conductor material, and when a low frequency current is applied,
An electric current will flow around the entire wire or the outer layer.

As described above, when a high frequency current is applied to the wire, it is equivalent to a wire made of a single layer material such as a conventional copper wire without deteriorating the performance and efficiency of the electric equipment to be incorporated. Performance and efficiency can be obtained. At the same time, as the material used for the inner layer, an inexpensive material, a material having a high tensile strength, or the like can be selected, and an additional value can be added to the wire.

Further, according to the wire of the present invention, the object is a wire having a plurality of layers in a radial direction, wherein the plurality of layers have a specific gravity in an outer layer rather than an inner layer. It is solved by being formed of a large material.

Since the outer layers of the plurality of layers are made of a material having a larger specific gravity in the outer layer than in the inner layer, the specific gravity of the material of the inner layer is small, so that it is possible to reduce the weight of the wire and to reduce the electricity consumption. -It is suitable because the weight of the electronic device can be reduced.

When a high-frequency current is applied, the current is distributed mainly in the outer layer due to the skin effect. Therefore, if the outer layer is made of a material having a high conductivity, the wire will be a conventional copper wire. Compared with the one-layer wire, it is possible to exhibit the same performance and efficiency without deteriorating the performance and efficiency of the incorporated electric equipment.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail with reference to the drawings. 1 is a partial sectional view of a motor of an embodiment, FIG. 2 is a sectional view of a wire of an embodiment, FIG. 3 is a longitudinal sectional view of a wire of an embodiment, and FIG. 4 is a distance from the center of the wire of the embodiment and conductivity. 5 is a sectional view of a motor of another embodiment, and FIG. 6 is a sectional view of a wire of another embodiment. The arrangement, shape, etc. described below are not intended to limit the present invention, and it goes without saying that various modifications can be made in accordance with the spirit of the present invention.

FIG. 1 shows an example in which the wire 1 of the present invention is applied to a motor 10. The motor 10 includes bearings 16a and 16b.
A rotor 11 supported by the rotor 11, a stator 17 provided on the outer periphery of the rotor 11, a frame 20 and a front cover 21 that accommodate them.

The rotor 11 includes a rotating shaft 12, a cylindrical magnet 15 that rotates integrally with the rotating shaft 12,
Further, a rotor core 1 provided on the outside thereof and integrally rotated
3 and 14 are provided. The stator 17 has a stator core 18
And winding 19 in which the wire 1 is wound around the stator core 18.
Equipped with.

In this motor 10, when the winding 19 is excited by a high frequency control current from a control unit (not shown), a rotating magnetic field is generated on the stator 17 side, and accordingly, the rotor core 1 is generated.
3, 14, the magnet 15, and the rotating shaft 12 rotate.

As shown in FIGS. 2 and 3, the wire 1 is composed of a core material 2, an intermediate layer portion 3, a surface layer portion 4, and an insulating portion (not shown) from the center thereof. In this embodiment, carbon fiber is used for the core material 2, aluminum is used for the middle layer portion 3, and copper is used for the surface layer portion 4.

Carbon fiber has a tensile strength of 3000.
0 kg / cm ² or so, about the electrical resistance 1500 (μΩ · m), in specific gravity of about 1.75, aluminum, tensile strength 1
100 kg / cm ^2, electric resistance 2.77 (μΩ · m) about a specific gravity of about 2.6. Also, copper has a tensile strength of 270.
0 kg / cm ² or so, about electric resistance 1.72 (μΩ · m), a specific gravity of about 8.65. Therefore, the wire 1 is made of a material having a smaller electric resistance in the outer layer, that is, a material having a larger electric conductivity. Further, a material having a smaller specific gravity is used for the outer layer.

Normally, when high frequency currents are used,
A skin effect occurs in which the current concentrates near the surface of the wire through which the high-frequency current is applied. In the wire 1 of the present embodiment, copper having a high electrical conductivity is used for the outermost surface layer portion 4 as a conductor portion and a material having a low electrical conductivity is used for the core material 2 on the premise of the skin effect. There is.

When a high frequency current is applied to the wire 1, the outermost layer of the wire 1, which has a large conductivity, has a large current density due to the skin effect. The central portion of the wire 1 is a portion where the current density originally decreases due to the skin effect when a high frequency current is applied. Therefore, wire 1
In the above, a core material 2 having almost no conductivity is used in the central portion, but a limiting current density almost equal to that of a conventional copper wire is secured.

The carbon fiber used as the material of the core material 2 has a small electric conductivity, but is very lightweight and has a large tensile strength.
It is suitable for use as. That is, the tensile strength of the wire 1 as a whole is increased, and the weight is further reduced.

The aluminum used for the middle layer 3 is
The electrical conductivity is as high as 62% of that of copper, so that the current can efficiently flow together with the surface layer portion 4, and the wire 1 can withstand the overcurrent without being damaged even when the overcurrent flows. Furthermore, since aluminum has a smaller specific gravity than copper, the weight of the wire 1 can be reduced, which is preferable.

Further, even if aluminum is used as the material of the intermediate layer portion 3, since the material of the surface layer portion 4 formed around the intermediate layer portion 3 is copper, when performing a terminal treatment or the like,
It does not require special soldering and can be handled like copper wire.

The materials of the core material 2 and the intermediate layer portion 3 of the present invention are not limited to those of this embodiment, and the conductive material is applied to the skin portion where the current is concentrated by the skin effect which occurs when the high frequency current flows through the wire 1. If a material having a high property is used, the core material 2 and the middle layer portion 3 are not limited to the conductivity such as an inexpensive material, a material having a small specific gravity, a material advantageous in recycling, and the like.
It is also possible to choose freely.

Since the wire 1 as described above is used for the winding 19 wound around the stator 17 of the motor 10, the high frequency control current from the control section has a high conductivity of the winding 19. Although it flows mainly through the surface layer portion 4, since the limiting current density of the winding wire 19 is about the same as that of the conventional copper wire, the motor 1
0 operates without lowering the efficiency as compared with the motor using the conventional copper wire.

Further, since the winding 19 is made of a material having a high conductivity also in the middle layer 3, the permissible current is kept large as a whole. Further, since the winding 19 made of the wire 1 is made lighter than the winding made of the conventional copper wire, the weight of the motor 10 is reduced as a whole.

The wire 1 can be manufactured by die drawing. At that time, the materials of the respective layers are formed in close contact with each other. The wire 1 can be manufactured by subjecting the core material 2 to surface treatment. Examples of the surface processing method include chemical (electroless) plating method, vacuum vapor method, sputtering method, electroplating method, anodizing method, laser alloy method, ion implantation method, ion beam mixing method, cluster (dual) ion beam method. , Ion plating method, plasma CVD method, plasma spraying method and the like.
However, the surface processing method is not limited to the above.

In the above embodiment, the case where the inside of the wire 1 has three layers has been shown, but the number of layers is not limited to three, and it may be two or four or more. FIG. 4 is a conceptual diagram showing the relationship between the distance from the center of the wire and the change in conductivity. In this figure, the material used for each layer is such that the outer layer has a higher conductivity. The wire 1 can be manufactured by combining various alloys having such conductivity.

As shown in FIG. 4, if a material having a higher conductivity is used in the outer layer, it is expected that the skin effect caused by the high frequency current can be used more efficiently in accordance with the frequency.

Further, as described above, the motor 10 has shown the example in which the wire 1 is used for the winding of the stator side armature. However, the motor 10 is not limited to the stator side and the rotor side as in the motor 30 of FIG. It can also be an armature winding.

The motor 30 includes a yoke 40 and a magnet 3
5, the rotor core 33, the winding 39 around which the wire 1 is wound,
Rotor 31 having rotating shaft 32, rotating shaft 3
It is composed of a commutator 42, a brush 43, and the like attached to the No. 2. The yoke 40 includes a cylindrical tubular portion 40a,
It is composed of an end portion 40b that closes one end of the tubular portion 40a on the open side.

One end of the rotary shaft 32 of the rotor 31 has a bearing 44 attached to the center of the end portion 40b.
Is rotatably supported by the shaft hole 45 at the other end.
The rotary shaft 32 functions as an output shaft. The operation control of the motor 30 is performed by supplying a high frequency control current to the brush 43 from a control unit (not shown). Since the motor 1 uses the wire 1 for the armature on the rotor side, the weight of the rotating portion is reduced, which is preferable.

As described above, according to this embodiment,
It has the following effects. (1) In this embodiment, the wire 1 is made of a multi-layered material, the surface layer portion 4 is made of a material having a large conductivity, and the middle layer portion 3 is made of a material having a relatively large conductivity. . Therefore, depending on the frequency of the current used, when the frequency is very high, the current mainly flows through the surface layer portion 4, and when the frequency is not so high, the surface layer portion 4 and the middle layer portion 3
Can be made to flow, and an electric current can be made to flow efficiently. Further, even when an overcurrent flows, the surface layer portion 4, the middle layer portion 3, and the core material 2 can pass the overcurrent, which is preferable.

(2) Conventionally, since the wire is made of a single layer of conductive material, the wire has been selected with an emphasis on conductivity. However, according to the embodiment, since the wire 1 is formed of the surface layer portion 4, the intermediate layer portion 3, and the core material 2 and the multilayer material, it is possible to use only a material having a large conductivity such as a wire of a single layer material. Instead, a material having a small specific gravity, a material having a large tensile strength, or the like can be used in the same single wire.

Since the wire 1 can be formed of a material suitable for the intended use, it is economically preferable. Further, since it is possible to satisfy high conductivity, weight reduction, large tensile strength and the like with one wire, it is possible to obtain an efficient wire.

Therefore, by using the wire 1, the weight can be reduced, and if the tensile strength is large, the armature can be wound without any gap, so that a more efficient motor can be obtained.

(3) In terms of recycling, when the wire 1 is used as an armature winding, and then is put into a furnace to be recovered and melted again, if iron is mixed with copper, the material of iron becomes remarkable. Although it deteriorates, the wire 1 is used in this embodiment.
Is a multilayer, and it is preferable to use a material other than copper other than the outer side because the proportion of copper that deteriorates the iron material is small.

(4) In this embodiment, since the surface layer portion 4 is made of copper, it is possible to prevent electrolytic corrosion caused by connection with the power supply line, for example.

(5) Since the wire 1 of this embodiment uses aluminum for the middle layer 3 and copper for the surface layer 4, it has a large electric conductivity which cannot be obtained by a single-layer aluminum wire. In addition to the above, it is possible to reduce the trouble of treating the surface for preventing electrolytic corrosion, which is required when a single-layer aluminum wire is used.

The embodiment of the present invention may be modified as follows. In the above embodiment, copper is used for the surface layer portion 4 of the wire 1, but the surface layer portion 4 may be made of another material having high conductivity such as silver. For example, by using silver for the surface layer portion 4, the specific gravity is larger than that of copper, but the conductivity is larger than that of copper, so that a more efficient wire can be obtained.

In the above embodiment, carbon fiber is used for the core material 2 of the wire 1, but steel may be used for the core material 2. By using steel for the core material 2, current can be passed through the core material 2 as well, so that it is possible to obtain a wire capable of supplying a more stable current, which corresponds to the use of current from high frequencies to low frequencies. . Also, the core material 2
Since magnetism can be passed along with the electric current, it is possible to miniaturize an electronic device or the like in which the wire 1 is incorporated.

Although the wire 1 has a circular cross section in FIG. 1, it may have a rectangular shape as shown in FIG. By making the wire rectangular, for example, when it is wound in a motor, it is possible to wind the wires 1 without forming a gap between them.

Further, in the above embodiment, an example in which the material is composed of three layers is shown, but the number of layers is not limited to three, and two or more layers may be used. If the outermost layer having high conductivity is used, the wire may be formed in two layers instead of multiple layers.

In the above embodiment, the wire 1 is used for the armature winding of the motor, but it can be used for all electric wires used in electric and electronic equipments, such as transformers and choke coils. Can be used for.

The technical idea will be described below as an example of a device to which the wire that can be grasped from the above-described embodiment can be applied. (1) An armature around which the wire according to claim 1 or 2 is wound. Even when high-frequency current is passed through the armature, the current flows mainly in the outer layer material with high conductivity,
The same amount of current can be passed as an armature made of only the above material, and added values such as weight reduction and high tensile strength can be given by the selected material of the inner layer.
Further, by making the material of the inner layer a material having a small specific gravity, the weight of the armature can be reduced.

(2) A motor having an armature around which the wire according to claim 1 or 2 is wound. By using the wire, the weight of the motor can be reduced and the efficiency thereof can be improved without lowering the efficiency of the motor.

[0054]

As described above, according to the wire of the present invention, the wire has a multi-layered shape, each layer is formed of a different material, and the material used for the outer layer is a material having a high conductivity. Thus, when a high frequency current is passed, the current can be efficiently used and the allowable current can be increased.

In the wire according to the present invention, the material used for the inner layer can be arbitrarily selected. For example, when the material having a small specific gravity is used, the weight of the entire wire can be reduced. Therefore, the electricity used by the wire
It is possible to reduce the weight and efficiency of electronic devices.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a motor according to an embodiment.

FIG. 2 is a cross-sectional view of a wire of an example.

FIG. 3 is a vertical cross-sectional view of a wire of an example.

FIG. 4 is a conceptual diagram showing the relationship between the distance from the center of the wire and the conductivity in the example.

FIG. 5 is a sectional view of a motor according to another embodiment.

FIG. 6 is a cross-sectional view of a wire of another embodiment.

[Explanation of symbols]

1 wire, 2 core material, 3 middle layer part, 4 surface layer part, 10, 30 motor, 11, 31 rotor,
12, 32 rotating shaft, 13, 14, 33 rotor core, 15, 35 magnet, 16a, 16b, 4
4 bearings, 17 stators, 18 stator cores,
19, 39 windings, 20 frame, 21 front cover, 40 yoke, 40a tubular part, 40
b end part, 42 commutator, 43 brush, 45
Shaft hole

Claims (2)

[Claims] 1. A wire provided with a plurality of layers in a radial direction, wherein the plurality of layers are formed of a material having a higher conductivity in an outer layer than in an inner layer. . 2. A wire provided with a plurality of layers in a radial direction, wherein the plurality of layers are formed of a material in which an outer layer has a larger specific gravity than an inner layer.