JP2009260502A - On-vehicle antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily attach an antenna to a wireless receiver. <P>SOLUTION: The antenna is connected to the reception circuit of a printed board housed inside the case of the wireless receiver through a connector mounted on the printed board, the antenna is formed of a metal wire wound around the electric wire group of a wire harness connected to the connector, a metal wire wired and bound together with the electric wire group or a metal wire fixed to the exterior tube of the wire harness, and a terminal connected to one end of the metal wire to be the antenna is connected through the connector to the reception circuit of the printed board. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vehicle-mounted antenna, and more particularly to an antenna connected to a wireless device mounted on an automobile, and is suitably used for wireless communication of a remote keyless entry system or a tire pressure monitoring system.

Recently, there has been provided a remote keyless entry system for locking and unlocking a car door without inserting a key into the keyhole and operating the system. This system receives a radio signal from a portable device owned by a user. It is received by an antenna of a radio device on the automobile side, and doors are locked / unlocked remotely.
Further, the automobile is also equipped with a wireless device such as a wireless device in a tire pressure monitoring system that includes a tire sensor mounted on a tire and a sensor receiver mounted on the vehicle body side.
For example, Japanese Patent Application Laid-Open No. 2001-352587 (Patent Document 1) has been proposed as an antenna structure necessary for this type of wireless device.

As shown in FIG. 9, the wireless receiver disclosed in Patent Document 1 has antennas 4a and 4b projecting from left and right ends of a printed circuit board 3 housed in a case 2, and the bases of these antennas 4a and 4b are provided. The end is soldered to a predetermined circuit on the printed circuit board 3.
In this way, the antennas 4a and 4b are integrated with the circuit of the printed circuit board 3 by soldering.
Since it is most desirable that the total length of the dipole antenna is about λ / 2 of the wavelength λ of the received radio wave, the received radio wave intended for the total length of the antennas 4a and 4b (for example, a remote keyless entry system) The length of each of the antennas 4a and 4b is set to about λ / 4.

  The frequency received by the wireless receiver is different between Japan and overseas, but when receiving a radio wave with a frequency of 300 MHz, the antenna length with the best reception efficiency is the length λ / 4 of each antenna element in the case of a dipole antenna. Is 20 cm to 25 cm.

  The antenna that requires the length can be obtained by projecting it from the printed circuit board and placing it at a high position. However, as in Patent Document 1, the antenna is integrated with the printed circuit board by soldering. When housed in the case, a space for antenna placement is required in the case, which increases the size. Since vehicle-mounted wireless devices are required to be miniaturized, it is necessary to make the antenna fit within the case, and the antenna cannot be sufficiently high from the printed circuit board. There is a problem that lowers the antenna gain. Further, if a space is used to improve the antenna gain, the number of parts increases. Furthermore, a fastener is required to fix the other end of the antenna connected to the printed circuit board and one end in the case, increasing the number of components and increasing the cost.

Furthermore, Japanese Patent Laying-Open No. 2005-45625 (Patent Document 2) proposes a configuration in which an antenna connected to a printed circuit board is integrally formed on the wall surface of the case.
However, in this case as well, there is a problem in that it is affected by noise from the IC chip and the receiving circuit on the printed circuit board accommodated in the case, and a separate shield must be performed to reduce the influence.

JP 2001-352587 A Japanese Patent Laid-Open No. 2005-45625

  The present invention has been made in view of the above problems, and provides an in-vehicle antenna capable of obtaining a high antenna gain without increasing the size of the case of the wireless device and without increasing the number of components of the wireless device. Is an issue.

In order to solve the above problems, the present invention is an antenna that is connected to a receiving circuit of a printed circuit board housed in a case of a wireless receiver via a connector mounted on the printed circuit board,
An antenna is formed with a metal wire wound around a wire group of a wire harness connected to the connector, a metal wire wired together with the wire group, or a metal wire fixed to an outer tube of the wire harness, and the metal wire used as the antenna A vehicle-mounted antenna is provided in which a terminal connected to one end of the antenna is connected to a receiving circuit of the printed circuit board through the connector.

  The vehicle-mounted antenna of the present invention is a novel antenna that is completely different from the antenna disposed inside the case of a conventionally provided wireless device, and as described above, a connector mounted on a printed circuit board in the wireless device It is comprised from the metal wire wound around the electric wire group of the wire harness to connect, the metal wire wired with the electric wire group, and bound with tape etc., or the metal wire attached to the tube exterior to the electric wire group of a wire harness.

Thus, when the antenna is arranged outside the case instead of inside the case of the wireless device, it is not necessary to provide a space for antenna placement inside the case, and the size of the wireless device can be reduced. In addition, when the antenna is wound around the electric wire group and fixed to the outer tube of the electric wire group in advance, it is not necessary to provide a support material for supporting the antenna. Furthermore, since the metal wire that becomes the antenna outside the case is simply placed on the wire harness connected to the case, the height of the antenna is not restricted, the antenna gain does not decrease, and the antenna is placed inside the case. It does not receive noise from the receiving circuit that occurs when it is placed.
Furthermore, since the wire group around which the antenna is wound is connected to the printed circuit board mounted connector inside the case, the tip of the antenna can be easily connected to the receiving circuit of the printed circuit board together with the wire group.

  When the metal wire is wired together with the wire group constituting the wire harness and bound together with the wire group with a tape or the like, it is not necessary to bend the metal wire. Moreover, when a metal wire is provided along the length direction on the exterior tube material, the metal wire is not bent. Furthermore, even when a metal wire is wound around the electric wire group, the bending angle is smaller than when the wire is bent at a right angle inside the case. Therefore, the antenna gain does not decrease, the antenna shape can be made close to a monopole type, and the antenna gain can be improved.

Specifically, the metal wire used as the antenna is in the form of a band covered with an insulating resin film, and an adhesive layer is provided on the outer surface of the insulating resin film, and is wound around and adhered to the wire group of the wire harness in a spiral manner. It is also preferable to use it as a bundling material.
With the above configuration, since it is only necessary to spirally form the belt-shaped antenna around the group of wires on the connector connection side, the antenna can be attached very easily. In the case where the electric wire group is previously wound with an insulating resin tape and bound, the band-shaped antenna is wound spirally around the outer peripheral surface of the insulating resin tape.
In addition, even when the wire group is not wrapped and tied with an insulating resin tape, the antenna metal wire is covered with the insulating resin film. It becomes a binding material.

Alternatively, the antenna of the present invention may be preliminarily coiled by molding the metal wire into a coiled resin piece. If it is this structure, if the electric wire group of a wire harness is inserted in the hollow part of a coil-shaped resin piece, an electric wire group can be bundled with the elastic force of a coil-shaped resin piece.
Moreover, you may form the conductor used as a metal wire in the said coil-shaped resin piece by plating, vapor deposition, etc.

Furthermore, a metal wire serving as an antenna may be fixed to a corrugated tube that is widely used as an exterior material for the wire group of the wire harness or a round tube without unevenness.
Specifically, a metal wire is fixed to the outer peripheral surface or inner peripheral surface of a corrugated tube made of a resin molded product in which annular convex portions and concave portions are alternately provided in the axial direction. At that time, the metal wire may be fixed linearly along the length direction of the tube, or may be wound spirally around the corrugated tube. Similarly, in the case of a round tube, a metal wire may be fixed linearly on the outer peripheral surface or inner peripheral surface of the tube in the length direction of the tube, or may be fixed by being wound spirally.
In any case, since the inner peripheral surface of the outer tube is in contact with the electric wire group, it is preferable to attach a metal wire to the outer peripheral surface.

  The metal wire used as the antenna of the present invention may be circular in cross section, rectangular, or flat, but the length is about λ / 4 of the reception wavelength, specifically 20 cm to 25 cm. The metal wire may be any of copper, aluminum, copper and an alloy mainly composed of aluminum (geralmin, brass, etc.).

The antenna of the present invention is suitably used for receiving a transmission signal from a remote key or smart key carried by an occupant or for receiving a detection signal of a tire sensor attached to a tire.
In the case of receiving a wireless signal from the keyless entry portable device, the wireless device may be housed in a keyless receiver unit mounted on a body-side instrument panel, etc. You may install in.

As described above, in the present invention, the antenna connected to the wireless device is sheathed on the metal wire that is wired and bundled together with the wire group of the wire harness connected to the wireless device, the metal wire wound around the wire group, or the wire group. It is formed of a metal wire fixed to the tube and is not housed inside the case of the wireless device.
Therefore, when the antenna is provided inside the case, it is not necessary to increase the size of the case in order not to reduce the antenna gain. In addition, since the antenna is provided outside the case, the antenna is not limited in height and is not affected by noise from the printed circuit board, so the antenna gain does not decrease. And since it attaches to the electric wire group of a wire harness, or the exterior tube of an electric wire group, the exclusive component for fixing antenna fixation is not required, but the cost reduction by reduction of a number of parts can be aimed at.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a first embodiment.
An in-vehicle wireless receiver 10 shown in FIG. 1 receives a transmission signal from a remote key dedicated for transmission, and is mounted on an instrument panel of an automobile.
Inside the case 12 of the wireless receiver 10, a printed circuit board 11 having a wireless reception circuit 11a provided on the circuit board 11b is fixed as shown in FIG. On the printed circuit board 11, a power supply circuit connected to the wireless IC 11c connected to the wireless reception circuit 11a, a ground circuit, and a transmission circuit 11e for transmitting the received signal to the wire harness connected to the wireless receiver 10 are provided. .

A connector 13 is mounted along one edge of the printed circuit board 11, and an L-shaped terminal 14 connected to the wireless receiving circuit 11 a, the power feeding circuit, and the ground circuit is accommodated and locked in the connector 13. The terminal 14 and the circuit of the printed board 11 may be connected by soldering, welding, or piercing a pin protruding from the terminal.
The connector 13 is disposed on the inner surface of the connector insertion opening opened in the side wall of the case 12 so that it can be fitted with a mating connector inserted from the outside.

As shown in FIG. 3, a connector 15 connected to the end of the wire harness W / H is fitted to the connector 13 as a mating connector.
The electric wire group w constituting the wire harness W / H is composed of a covered electric wire in which a core wire is covered with an insulating resin layer, and a terminal (not shown) is connected to each end of each of the covered electric wires. It is housed and locked in the connector 15. When the connector 15 is fitted to the connector 13, the terminals of the wire group are connected to the terminals 14 in the connector 13.

  As shown in FIG. 1, the antenna 20 is spirally wound around the outer periphery of the wire group w of the wire harness W / H. The antenna 20 is a metal wire made of copper wire and has a length of 20 to 25 cm. As shown in FIG. 2, the antenna 20 made of this metal wire is formed in a band shape in which an insulating coating is formed by sticking or fusion-bonding to the center of a pair of band-shaped insulating resin films 21. And the adhesion layer is provided in the outer surface side of the insulating resin film 21 of the one surface side, and it adheres in the state which wound the antenna 20 around the outer peripheral surface of the electric wire group w.

  The connection side with the connector 15 on the other end side of the antenna 20 projects a metal wire without covering the insulating resin film 21 and crimps and connects the terminals 22. The terminal 22 is housed and locked in the connector 15 together with the terminal connected to the wire group w.

  In a state where the connector 15 connected to the end of the wire harness W / H and the connector 13 in the case 12 are fitted, the terminals of the electric wire group w are fed to the power supply circuit of the printed board 11 via the terminals 14 in the connector 13. The terminal accommodating positions in the connectors 13 and 15 are set so that the terminal 22 of the metal wire terminal connected to the ground circuit and the transmission circuit and the antenna 20 is connected to the terminal 14A connected to the reception circuit.

In the above configuration, the antenna 20 is not housed in the case 12 of the wireless receiver 10, and is wound around the wire group w of the wire harness W / H connected to the connector 13 in the case 12 and arranged outside. There is no need to provide an antenna housing space in the case 12, and the case 12 can be miniaturized. Further, since the antenna 20 is not arranged in the case 12, the influence of noise from the printed circuit board 11 side can be eliminated, and the antenna gain can be increased.
Further, since the antenna 20 made of a metal wire is wound around and adhered to the wire group w, the antenna mounting component is not required and can be easily mounted.
Furthermore, when the connector 15 of the terminal of the wire harness W / H is fitted and connected to the connector 13 of the wireless receiver 10, the antenna 20 can also be connected to the wireless reception circuit of the printed board 11 in the case 12 at the same time.

  Although the first embodiment is a wireless receiver that receives transmissions from a remote key dedicated to transmission, the antenna of the present invention is attached to a wireless device that transmits / receives data to / from a smart key that can be transmitted / received, and transmission from the smart key is performed. And an antenna for transmitting to the smart key.

FIG. 4 shows a modification of the first embodiment. In the modification, the antenna 20 made of a metal wire covered with the insulating resin film 21 is not wound spirally around the wire group w, but is kept in a straight line shape. Wiring with w.
When the wire group w is wound around the outer periphery of the wire group w with the adhesive tape T and bound, the antenna covered with the insulating resin film 21 is simultaneously wound and bound together with the wire group w.
With this configuration, it is not necessary to bend the metal wire serving as the antenna 20 in a spiral shape.
Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

5A and 5B show the antenna of the second embodiment.
An antenna 20 made of a metal wire is integrally provided on a coil-shaped resin piece 25 that is previously formed into a coil shape. That is, the metal wire is molded when the coiled resin piece 25 is molded.
The configuration for connecting to the connector of the wireless receiver is the same as in the first embodiment.

With this configuration, when the central space surrounded by the coil-shaped resin piece 25 is widened, the wire group w constituting the wire harness W / H is passed, and after insertion, the coil-shaped resin piece 25 is returned to the original state, the coil-shaped resin The piece 25 is elastically restored and can be fixed to the outer periphery of the electric wire group w by an elastic force, and the electric wire group w itself can be bound.
Therefore, it is not necessary to wind and spirally adhere to the outer peripheral surface of the wire group w of the wire harness W / H.

  Instead of insert-molding the metal wire used as the antenna to form the coil-shaped resin piece 25, as shown in FIG. 5C, after the coil-shaped resin piece 25 is formed, the length direction is formed on the outer surface side thereof. Then, a conductive material may be plated or vapor-deposited to form a metal conductor 20 ′ serving as an antenna.

6A and 6B show a third embodiment.
The antenna 20 made of a metal wire according to the third embodiment is attached to a corrugated tube 30 that is mounted on the wire group w of the wire harness W / H.
The corrugated tube 30 is made of a resin molded product, and is provided with annular convex portions 30a and concave portions 30b alternately in the axial direction.
As shown in FIG. 6A, the antenna 20 made of a metal wire is arranged linearly along the length direction of the corrugated tube 30 on the outer peripheral surface side of the corrugated tube 30 and connected to the outer surface of the convex portion 30a. It is fixed with an agent.
The corrugated tube 30 may be spirally wound around the outer peripheral surface and fixed with a connecting agent.
Further, when the antenna 20 is attached to the outer surface of the corrugated tube 30, the antenna 20 made of a metal wire is covered with an insulating resin film as in the first embodiment.

Furthermore, as shown in FIG. 6B, the antenna 20 made of a metal wire may be fixedly attached to the inner surface side of the corrugated tube 30 with a connecting agent. Since it is accommodated in the corrugated tube 30, it is not necessary to cover the antenna 20 made of a metal wire with an insulating coating film.
Further, the tip is projected outside from a hole or slit provided in the corrugated tube 30.

7A and 7B show a fourth embodiment of the antenna.
The fourth embodiment is different from the third embodiment only in that the antenna 20 made of a metal wire is attached to the round tube 35 having no unevenness.
Since other configurations and operations are the same as those of the third embodiment, description thereof is omitted.

FIG. 8 shows a fifth embodiment.
In the fifth embodiment, the wireless receiver 10 of the first embodiment is used for reception from a tire pressure sensor (TPMS sensor) mounted on a vehicle tire.
Specifically, TPMS sensors 56A to 56D that detect tire air pressure are attached to the front and rear, left and right four tires 55 attached to the vehicle 50, and the detection signals from these TPMS sensors 56A to 56D are transmitted wirelessly. The signal is received by the antenna 20 attached to the wire harness W / H connected to the receiving device 10 and transmitted to a receiving circuit for monitoring the air pressure of the printed circuit board in the wireless receiving device 10.

FIG. 2A is a perspective view showing a first embodiment of the present invention. An antenna is shown, (A) is sectional drawing, (B) is drawing of a connection part with a terminal. It is a perspective view which shows the connector connection part of the printed circuit board in a radio | wireless receiver, and an antenna. It is the schematic which shows the modification of 1st Embodiment. A 2nd embodiment is shown, (A) is a perspective view of an antenna, and (B) is a perspective view in the state where an antenna was attached to an electric wire group. (A) and (B) are perspective views of a third embodiment. (A) and (B) are perspective views of a fourth embodiment. It is a perspective view at the time of using the wireless receiver provided with the antenna of 1st Embodiment for a tire pressure monitoring system which shows 5th Embodiment. It is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 In-vehicle wireless receiver 11 Printed circuit board 11a Reception circuit 12 Case 13, 15 Connector 14, 22 terminal 20 Antenna 21 made of metal wire Insulating resin film 25 Coiled resin piece 30 Corrugated tube 35 Round tube W / H Wire harness w Wire group

Claims (5)

An antenna connected to a receiving circuit of a printed circuit board housed in a case of a wireless receiver via a connector mounted on the printed circuit board,
An antenna is formed of a metal wire wound around a wire group of a wire harness connected to the connector, a metal wire wired together with the wire group, or a metal wire fixed to an outer tube of the wire harness, and the metal wire used as the antenna A terminal connected to one end of the printed circuit board is connected to the receiving circuit of the printed circuit board via the connector.   The metal wire has a belt-like shape coated with an insulating resin film, an adhesive layer is provided on the outer surface of the insulating resin film, and is wound around and adhered to a wire group of the wire harness, and is also used as a converging material for the wire group. Item 2. The vehicle-mounted antenna according to Item 1.   The metal wire is molded into a coil-shaped resin piece, or a conductor to be a metal wire is plated or vapor-deposited on the coil-shaped resin piece, the wire group of the wire harness is inserted, and the wire group is formed into a coil-shaped resin piece. The in-vehicle antenna according to claim 1, which is bound by the elastic force of the vehicle.   The metal wire is fixed to an outer peripheral surface or an inner peripheral surface of the outer tube of the electric wire group composed of a corrugated tube or a resin-made cylindrical round tube in which annular convex portions and concave portions are alternately provided in the axial direction. The in-vehicle antenna according to claim 1.   The vehicle-mounted antenna according to any one of claims 1 to 4, which receives a transmission signal from a remote key or a smart key or a detection signal of a tire sensor attached to a tire.

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