JPH07230914A - High-frequency coil for automobile glass antenna and glass antenna for automobile - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of the inductance value of a coil by regularizing the shape of bobbins, and dispensing with the necessity of changing the magnitude of magnetic substances and changing the number of turns, diameter, etc., of a conductor. CONSTITUTION:The title high-frequency coil for car glass antenna is composed of a recession 9 provided on the side surface of a bobbin made of a columnar substance having an insulating ability, a magnetic substance 3 kept in the recession 9, a lead wire 2 wound on the side surface of the bobbin 1, and two conductive joining parts 4 fitted to both bottoms of the bobbin 1 respectively, and the ends of the lead wire 2 are fixed to the conductive joining parts 4. And the title high-frequency coil for car glass antenna is formed by providing grooves 5 in the conductive joining parts 4 and fixing the lead wire 2 to the insides of the grooves 5, or uniting the bobbin 1 and the conductive joining parts 4 into a body. As a result of this, the electric characteristic of the coil is regularized, and characteristic precision is made higher. And it becomes possible to maintain a stable electric characteristic.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency coil for a glass antenna of an automobile, which is used for preventing leakage of radio waves received by a glass antenna of an automobile and preventing noise.

[0002]

2. Description of the Related Art An electrically heated defogger 14 having a heater wire 15 and bus bars 13a and 13b for supplying power to the heater wire 15 on a glass plate 11 of a rear window of an automobile, as shown in FIG. 3, and an antenna conductor having a predetermined pattern. 16 are provided, and the defogger 14 and the antenna conductor 16 are capacitively coupled to each other at a predetermined interval so that direct current is not transmitted / received between them but high frequency current is transmitted / received between them. Automotive glass antennas are known.

Reference numeral 10 is a high frequency coil for an automobile glass antenna for cutting high frequency components.

The frequency of the FM broadcast band cannot be cut only by the choke coil 19 because the choke coil 19 originally for the AM broadcast band does not function sufficiently in the FM broadcast band. Therefore, in the FM broadcast band, the defogger 14 is not completely insulated from the grounded body, and the defogger 1
When 4 is used as an antenna, the receiving sensitivity becomes poor.

Therefore, in order to cut the frequency of the FM broadcasting band which cannot be completely cut by the choke coil 19 alone, the coil 10 is inserted between the bus bars 13a and 13b and the choke coil 19 as shown in FIG. . In FIG. 3, 17 is a battery.

However, in the conventional coil 10, the coil 10 is simply made of a magnetic material, and a conductor is wound around the magnetic material, or a cylindrical bobbin is provided with the magnetic material. It was a wire wound around a bobbin.

With a bobbin made of a magnetic material, the size of the magnetic material is almost fixed once the required coil shape is fixed, and it is difficult to adjust the inductance value of the coil. If you do not want to increase the size of the magnetic material that affects the magnetic field, the bobbin made of the magnetic material becomes smaller, which reduces the accuracy of the winding process of the conductive wire, making it impossible to manufacture a coil with uniform electrical characteristics. There was a drawback that the strength was insufficient.

Further, when a magnetic body is put inside a cylindrical bobbin to form a coil, it is difficult to fix the magnetic body inside the bobbin if the magnetic body is smaller than the inner diameter of the bobbin. There was a drawback that the electric characteristics of the coil were not constant due to the movement of the inside of the bobbin.

[0009]

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned drawbacks of the prior art, and newly provides a high frequency coil for an automobile glass antenna, which has not been heretofore known. It is a thing.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is accommodated in a concave portion provided on the side surface of a bobbin formed of a columnar body having an insulating property and the concave portion. Automotive glass characterized by comprising a magnetic body, a conductor wire wound around the side surface of a bobbin, and two conductive coupling parts attached to both bottom surfaces of the bobbin, and the ends of the conductor wire being fixed to the conductive coupling part. A high frequency coil for an antenna is provided.

Further, the present invention provides the above high-frequency coil for an automobile glass antenna, characterized in that a groove is provided in the conductive coupling portion and a conductor is fixed in the groove.

Further, the present invention provides a high frequency coil for an automobile glass antenna, characterized in that the bobbin and the conductive coupling portion are integrally molded.

Further, an electrically heated defogger having a heater wire and a plurality of bus bars for supplying power to the heater wire and an antenna conductor having a predetermined pattern are provided on the glass plate of the rear window of the automobile, and the defogger and the antenna conductor are further provided. In at least a part of them, in a glass antenna for an automobile in which a direct current is not transmitted and received between the two, but a high frequency current is transmitted and received, the glass antenna for an automobile is closely coupled at a predetermined interval and one bus bar is connected. There is provided a glass antenna for an automobile, wherein a choke coil and the high frequency coil for an automobile glass antenna are inserted in series in at least one of a positive electrode of a battery and another bus bar and a ground.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a typical example of the coil of the present invention. 1
Is a bobbin, 2 is a lead wire, 3 is a magnetic body, 4 is a conductive coupling portion, 5
Is a groove portion, 6 is a connecting portion between the conductor wire 2 and the lead wire 8, and 9 is a recess portion provided on the side surface of the bobbin 1. Figure 2 shows longitudinal and 9
It is sectional drawing of the bobbin 1 of 0 degree direction.

The bobbin 1 needs to be made of a material having an insulating property, and ceramics, hard rubber, synthetic resin or the like can be used. Among them, it is desirable to use a synthetic resin excellent in strength.

Among the synthetic resins, usually epoxy resin,
Polycarbonate resin or the like is used. However, when the strength of the synthetic resin is insufficient, it is preferable to use the synthetic resin containing glass fiber. Regarding the material of the conductive coupling portion 4, the same material as that of the bobbin 1 is usually used.

The shape of the bobbin 1 is preferably a cylinder, an elliptic cylinder, a polygonal cylinder, or the like, but it is preferable to use a cylinder in order to improve the winding precision of the conductor 2.

The diameter of the bobbin 1 is 3.0 mm to 30 mm.
The range is preferable for reasons of reception characteristics and the like. 3.
If it is less than 0 mm, it will be difficult to wind the coil, and
If it exceeds mm, the required inductance cannot be obtained in the high frequency region. More desirable range is 3.5 mm to 20 mm
Is.

The conductor 2 may have a circular or elliptical cross section, a triangle, a quadrangle, a polygon, or the like.
A circular wire is desirable for convenience of processing.

The cross-sectional area of the conductor portion of the conductor 2 is 0.1 mm ²
The range of 23.8 mm ² is preferable, and any shape having a cross-sectional area that satisfies the power consumption of the Defogger can be used. 0.
If it is less than 1 mm ² , the current required for the defogger cannot be passed, and if it exceeds 23.8 mm ² , the shape becomes too large, which is not preferable. 1.0mm ² ~5.0mm ² about is more desirable. A polymer material is suitable for the insulating coating of the conductive wire 2. Enamel and high polymer materials such as polyurethane are preferable. The conductive wire 2 is not limited to this material, and any conductive wire whose surface is insulation-coated can be used.

It is suitable that the number of turns of the conductor wire 2 is usually about 2 to 30 times. When the windings of the conductor wire 2 are in contact with each other, the self-resonance frequency is 50 MH in the range of 3 to 15 turns.
z ~ 100MHz, and the more the winding space is opened,
The self-resonant frequency becomes high.

The magnetic material 3 was used to adjust the electrical characteristics of the coil of the present invention. The use of the magnetic body 3 increases the inductance, and the coil shape can be reduced. Ferrite, carbonyl iron, sendust, or the like can be used as the material of the magnetic body 3. As the magnetic characteristics of the magnetic material used for the magnetic body 3, the maximum magnetic permeability μ _max is preferably 10 to 10 ^{6 in view} of reception characteristics, and more preferably 10 ² to 10 ⁴ . 1
If it is less than 0, the effect of using the magnetic material 3 cannot be obtained, and 10 ⁶
If it exceeds, magnetic saturation occurs in the material of the magnetic body 3 or high frequency characteristics deteriorate, and the effect of using the magnetic body 3 cannot be obtained.

As the magnetic characteristics of the magnetic body 3, the loss coefficient (1 / μiQ) is preferably in the range of about 1 × 10 ^{-8 to} 1.0. If it is less than 1 × 10 ⁻⁸ , the usable frequency becomes narrow and it becomes difficult to use it in the entire reception frequency band. If it exceeds 1.0, the loss is large and the effect of using the magnetic material 3 cannot be obtained. The diameter of the magnetic body 3 is preferably larger than 0.2 mm. This is because if it is less than 0.2 mm, the effect of using the magnetic body 3 cannot be obtained.

The length of the magnetic body 3 is preferably in the range of 2 to 30 mm, and if it is less than 2 mm, the effect of using the magnetic body 3 cannot be obtained, and if it exceeds 30 mm, the strength becomes brittle, which is not desirable.

A recess 9 for accommodating the magnetic body 3 is provided on the side surface of the bobbin 1. The recess 9 usually has a long shape in the longitudinal direction of the bobbin 1, and the shape is determined according to the size of the magnetic body 3.

The conductive coupling portion 4 may be molded integrally with the bobbin 1, but it is preferable that the conductive coupling portion 4 is not integrated with the bobbin 1 and is a separate component. The reason for this is that if the conductor 2 is wound in a coil shape in advance by a winding machine and then inserted into the bobbin 1, the electrical characteristic accuracy can be obtained. Further, in this case, if the conductive coupling portion 4 is fitted to the bobbin 1 after the winding is completed and attached by screwing or the like, the productivity is improved.

A connecting portion 6 for connecting the conducting wire 2 and the lead wire 8
May be provided on the surface of the conductive coupling portion 4 where the groove portion 5 is not provided, but it is desirable to provide the groove portion 5 provided in the conductive coupling portion 4 in order to improve the safety of the connection, and thereby the high frequency characteristics are obtained. Is stably obtained, and productivity is also improved.

It is preferable that the groove 5 is provided with a conductive terminal adhered thereto by an adhesive or the like. This is because if the end portion of the conductor wire 2 is adhered to this terminal with solder or the like and the lead wire 8 is adhered to this terminal with solder or the like, the conductor wire 2 and the lead wire 8 can be easily adhered. When the terminal is not provided, the lead wire 2 and the lead wire 8 may be connected by crimping or crimping terminals, or may be connected by soldering or the like. In this case, the connecting portion 6 is directly connected to the conductive coupling portion by an adhesive or the like. Bonded to 4.

It is preferable that the diameter of the conductive wire connecting portion 4 according to the present invention is larger than the diameter of the bobbin because the coil of the present invention can be easily attached. Usually diameter 3.5-35m
m is used.

It is preferable to cover the entire coil of the present invention with a synthetic resin tube or the like because the weather resistance is increased and the dielectric strength voltage can be further increased. It is desirable to use a heat shrinkable tube as the synthetic resin tube from the viewpoint of improving productivity.

[0032]

EXAMPLE A coil as shown in FIGS. 1 and 2 was manufactured. The bobbin was made of epoxy resin and had a cylindrical bobbin size of 5.0 mmφ × 20 mm. The conductive coupling portion 4 is made of the same material as the bobbin, has a cylindrical shape, and has a size of 8.4φ × 5 mm.
And In addition, the concave portion provided on the bobbin has a size of 3.5 mm.
φ × 17 mm. The magnetic body was made of ferrite and had a size of 3.5φ × 17 mm, and the magnetic body was fitted and fixed in the recess. Further, the maximum magnetic permeability μ _max of the magnetic material was 5000 and the loss coefficient was 6 × 10 ⁻⁵ .

A 1.6 mmφ copper wire with a polyurethane coating was used as the conducting wire, and the number of turns was 6 times. After the conductor wire was mechanically wound, the conductive coupling portion was fitted and adhered to the bobbin. The connection portion was fixed to the groove portion of the conductive coupling portion with an adhesive.

The coil of the example manufactured as described above exhibited the performance of a self-resonance frequency of 78 MHz and a rated current of 20 A. The tensile strength of the lead wire was 20 kg or more.

When the coil of the embodiment is used as the coil 10 shown in FIG. 3, it is F when compared with the case without the coil.
The reception sensitivity was improved by an average of 3 dB over the entire M broadcasting band.

Incidentally, 100 coils of the embodiment were manufactured,
When the self-resonant frequency was measured, the variation was ± 0.
It was in the range of 5 MHz.

[0037]

According to the present invention, since the shape of the bobbin is constant, it is not necessary to change the size of the magnetic body or the winding number, diameter, etc. of the conductive wire, so that the inductance value of the coil can be adjusted. It's easy. Furthermore, since the magnetic body is stably fixed to the bobbin, the electric characteristics of the coil are constant. Furthermore, when the bobbin and the conductive coupling portion are not integrally molded and are molded separately, the coiled wire of the conductor can be inserted into the bobbin in advance, so that the electric Characteristic accuracy is improved and there are few variations in the electrical characteristics of the coil. Further, by fixing the connecting portion between the lead wire and the conducting wire to the conductive coupling portion, the conducting wire does not move even when a force is applied to the lead wire, so that it is also possible to maintain stable electrical characteristics.

[Brief description of drawings]

FIG. 1 is a perspective view showing a typical example of a coil of the present invention.

FIG. 2 is a cross-sectional view of the bobbin in the longitudinal direction and the 90 ° direction of the coil of FIG.

FIG. 3 is a basic configuration diagram of a glass antenna device for an automobile in which the coil of the present invention is used.

[Explanation of symbols]

 1: Bobbin 2: Conductive wire 3: Magnetic material 4: Conductive coupling portion 5: Groove portion 6: Connection portion 8: Lead wire 9: Recessed portion

Claims (4)

[Claims] 1. A concave portion provided on a side surface of a bobbin formed of an insulating columnar body, a magnetic body housed in the concave portion, a conductor wire wound on the side surface of the bobbin, and both bottom surfaces of the bobbin. Consists of two conductive couplings attached to
A high frequency coil for an automobile glass antenna, characterized in that an end portion of a conductor wire is fixed to a conductive coupling portion. 2. A high frequency coil for an automobile glass antenna according to claim 1, wherein a groove is provided in the conductive coupling portion, and a conductor is fixed in the groove. 3. The high frequency coil for an automobile glass antenna according to claim 1, wherein the bobbin and the conductive coupling portion are integrally molded. 4. An electrically heated defogger having a heater wire and a plurality of bus bars for supplying power to the heater wire, and an antenna conductor having a predetermined pattern are provided on a glass plate of a rear window of an automobile, and the defogger and the antenna conductor are further provided. In at least a part of them, in a glass antenna for an automobile in which a direct current is not transmitted and received between the two, but a high frequency current is transmitted and received, the glass antenna for an automobile is closely coupled at a predetermined interval and one bus bar is connected. A choke coil and the high frequency coil for an automobile glass antenna according to claim 1, claim 2 or claim 3 are inserted in series in at least one of the positive electrode of the battery and the other bus bar and the ground. A glass antenna for automobiles.