JP2001057313A - Coaxial non-contact transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the transfer efficiency of a coaxial non-contact transformer using an electromagnetic induction system. SOLUTION: Formed materials consisting of a coil 2a formed by winding a wire material and two magnetic material cores, which pinch-in the coil 2a between them from the upper and lower sides and are formed into an annular discoid form, are used for a coaixal non-contact transformer, and these formed materials having different diameters are combined to each other into a concentrical form and in close proximity to the diametrical direction of the transformer, whereby the transfer efficiency of the transfomer is increased. Moreover, it is preferable that magnetic material sleeves 5a and 5b formed by winding a strip plate-shaped magnetic steel plate are provided on at least either of the inner peripheral part, which is formed on the innermost side of the core, and the outer peripheral part, which is formed on the outermost side of the core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction type electronic component for supplying power and transmitting a signal between a movable portion and a fixed portion around a rotating shaft, and more particularly to a steering wheel portion of a four-wheel vehicle. And a non-contact type transformer suitable for power supply and signal transmission at the handle portion.

[0002]

2. Description of the Related Art At present, four-wheeled vehicles are widely used worldwide, and almost all of them are equipped with an electric system such as an air conditioner and a car navigation system, and most of them are near a front panel or near a base of a steering wheel. The operation system is concentrated in For this reason, when operating the electrical system, one hand is temporarily removed from the steering wheel, and there is a high possibility that a wrong operation of the steering wheel may lead to a large accident during high-speed running. In order to improve this point, recently, a four-wheeled vehicle which has a control switch of an electric system in a steering wheel portion and which does not need to be released from the steering wheel even at the time of operation and which is considered in consideration of safety has been widely used. In this case, a wired system is used for power supply and reception to and from the operation system in the handle portion, and a flexible wire having spring properties is used so as not to be disconnected by the rotation operation of the handle. This is a rounded flat cable in which a plurality of wires are arranged in parallel, so that even if the handle is rotated, no tension is applied to the wires and the wires are not broken.

[0003] However, this wire must be installed in a neutral position because it is necessary to be able to rotate left and right evenly when operating the handle. Position adjustment is a very time-consuming operation during assembly. ing. In addition, some users argue that the wires are rubbed at the time of operation, so that the product life is short, and that the sound generated when the wires are rubbed and the comfort is impaired due to slight resistance generated when operating the steering wheel.

In order to solve these problems, conventionally, a facing non-contact type transformer as shown in FIG. 4 has been used. It is composed of a pair of opposing ferrite cores 21 and 22, wires 23 and 24 disposed on opposing surfaces of the cores, and magnetic sleeves 25 and 26 made of a magnetic steel plate. Power supply and signal transmission.

[0005]

However, the transmission efficiency of power supply and signal transmission by the opposed type non-contact type transformer is only about 40%. In the present invention,
It is an object to improve the transmission efficiency of a non-contact type transformer using an electromagnetic induction method.

[0006]

According to the present invention, there is provided a coaxial non-contact type transformer comprising a wire wound around a wire and two magnetic cores having an annular flat plate shape sandwiching the wire from above and below. The transmission efficiency is increased by using the formed products having different diameters and combining the formed products having different diameters concentrically and closely in the radial direction.

Further, it is preferable to provide a magnetic sleeve formed by winding a strip-shaped magnetic steel sheet on at least one of the inner peripheral portion and the outer peripheral portion of the innermost magnetic core.

[0008]

FIG. 3 schematically shows the configuration of a coaxial non-contact transformer according to the present invention. 11a, 11b, 13a, 13b
Is a ferrite core, 12a and 12b are winding portions, 15a and
15b is a magnetic sleeve.

By employing a coaxial type non-contact transformer, the positional accuracy of each portion of the magnetic core is determined substantially depending on the processing accuracy of the magnetic core. Therefore, the distance between the magnetic cores, that is, the gap length can be reduced to about 1 mm.

As a result, since the magnetic path length can be shortened, the inductance value of the magnetic core increases, the exciting current can be suppressed low, and the Joule loss due to the electric resistance of the winding portion is reduced. Since the magnetic flux density generated in the magnetic core decreases as the exciting current value decreases, iron loss such as hysteresis loss of the magnetic core also decreases. By reducing the gap length, the leakage magnetic flux is reduced, and the transmission efficiency is improved.

Further, at least one of the inner peripheral portion of the innermost magnetic core and the outer peripheral portion of the outermost core,
By providing the magnetic sleeve formed by winding a strip-shaped magnetic steel plate, the magnetic coupling between the pair of magnetic cores sandwiching the wire loop is further improved, and the leakage of magnetic flux is reduced. That is, the transmission efficiency is improved by reducing the copper loss and the leakage magnetic flux. In addition, most of the external noise is shielded by this part due to the interposition of the magnetic sleeve, so that a highly reliable non-contact type transformer which is hardly affected by the external noise can be obtained.

[0012]

Embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 shows an embodiment of a non-contact type transformer according to the present invention. This transformer is 52.7
_{mol% Fe 2 O 3 -39.3mol%} NiO-8.0m
ol% ZnO Mn-Zn ferrite material, made of the same material as the disk-shaped cores 1b and 3b having an outer diameter of 70 mm, an inner diameter of 60 mm, and a thickness of 3 mm, and having an outer diameter of 58 m.
m, inner diameter 48 mm, thickness 3 mm, disk-shaped core 1a, 3
a, and winding portions 2a and 2b formed by winding a formal coated copper wire having a diameter of 0.4 mm for 30 turns.

In this embodiment, the windings 2a to 2b
Power is being transmitted. The core 1a and the core 1b and the core 3a and the core 3b are each a pair, and the winding portions 2a and 2b are sandwiched by the cores 1a and 3a and the cores 1b and 3b, respectively. It is embedded with silicon resins 4a and 4b having excellent insulating properties. These are concentrically combined to form a coaxial non-contact transformer.

Using this non-contact transformer, the transmission efficiency was measured. The input was 16 V / 15 W, and a sine wave input having a frequency of 20 kHz was used by a function generator. The output is measured by a spectrum analyzer,
When the output power was determined, an output power of 6.5 W was obtained, and the transmission efficiency was 43%.

Further, in the same manner, in the conventional non-contact type non-contact transformer shown in FIG. 4, the opposing interval between the ferrite cores 21 and 22 is set to 3 mm which is the shortest interval allowable in this shape. In addition, for comparison under the same conditions as those of the present embodiment, measurement was made with the magnetic sleeve removed, and the output power was 4.9 W and the transmission efficiency was 33%. By the way, when the same measurement was performed for a conventional facing non-contact type transformer having a magnetic sleeve, the output power was 6.0 W and the transmission efficiency was 40%.

(Embodiment 2) FIG. 2 shows a coaxial non-contact type transformer according to another embodiment of the present invention. This transformer is obtained by adding magnetic sleeves 5a and 5b formed by winding a 45% Ni-Fe magnetic steel sheet having a thickness of 0.1 mm to the coaxial non-contact transformer described in the first embodiment. The magnetic sleeves 5a and 5b are respectively provided on the inner peripheral portion of the molded body in which the winding portion 2a is sandwiched between the cores 1a and 3a and on the outer peripheral portion of the molded body in which the winding portion 2b is sandwiched between the cores 1b and 3b. The layers are wound and the silicone resin 4a, 4b
It is fixed by bonding.

Using this coaxial non-contact transformer, the transmission efficiency was measured. The input was 16 V / 15 W, and a sine wave input having a frequency of 20 kHz was used by a function generator. The output was measured by a spectrum analyzer, and the output power was obtained. As a result, an output power of 7.5 W was obtained, and the transmission efficiency was 50%.

In the same manner, in the conventional opposed-type non-contact type transformer shown in FIG. 4, the opposed interval between the ferrite cores 21 and 22 is set to 3 mm which is the shortest interval allowable in this shape. The case was measured. As a result, as described in the first embodiment, the output power is 6.0 W
And its transmission efficiency was 40%. It is considered that the transmission efficiency can be improved by arranging the ferrite cores in such a coaxial shape in other magnetic cores.

[0020]

According to the present invention, by adopting a coaxial type as the non-contact type transformer, the interval between cores, that is, the gap length can be reduced.
Since the magnetic path length can be shortened, the inductance value of the core increases, and the exciting current value can be suppressed low.
As a result, a non-contact type transformer with reduced iron loss and copper loss and improved transmission efficiency can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view showing a coaxial non-contact type transformer according to a first embodiment of the present invention.

FIG. 2 is a sectional perspective view showing a coaxial non-contact type transformer according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a coaxial non-contact transformer according to the present invention.

FIG. 4 is a sectional perspective view showing a schematic configuration of a conventional opposed-type non-contact transformer.

[Explanation of symbols]

 1a, 1b Ferrite core 2a, 2b Winding section 3a, 3b Ferrite core 4a, 4b Silicon resin 5a, 5b Magnetic sleeve 11a, 11b Ferrite core 12a, 12b Winding section 13a, 13b Ferrite core 15a, 15b Magnetic sleeve 21 , 22 Ferrite core 23, 24 Winding part 25, 26 Magnetic sleeve

Claims (2)

[Claims] 1. A structure comprising a wire wound around a wire and two magnetic cores having an annular flat plate shape sandwiching the wire from above and below, and the concentric circles having different diameters. A coaxial non-contact type transformer characterized by being combined in a radially close proximity. 2. The coaxial non-contact transformer according to claim 1, wherein a strip-shaped magnetic steel sheet is wound around at least one of an inner peripheral portion and an outer peripheral portion of the innermost magnetic core. A coaxial non-contact type transformer having a magnetic sleeve formed by rotation.