JP2001303819A - Keyless entry device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of the whole device by ensuring required sensitivity by an antenna at a comparatively low cost in a keyless entry device for an automobile. SOLUTION: The antenna 7 for starting transmitting a starting signal to an electronic key from at least a receiver is installed to an internal surface on the cabin side of a car-body side pillar 1 positioned in front or in rear of a door. Accordingly, the comparatively large-sized air-core antenna, which does not use an expensive ferrite core, can be mounted at a place not covered with the iron plate of the pillar, thus reducing cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyless entry device for a motor vehicle, and more particularly to an antenna arrangement thereof.

[0002]

2. Description of the Related Art An automobile which unlocks a lock device when it is detected that an electronic key is within a predetermined distance from a receiver, and locks the lock device when it is not detected that it is within a predetermined distance. Keyless entry devices are known (see, for example, JP-A-9-125776).
In this type of device, an activation signal transmitted from a receiver mounted on an automobile to an electronic key and a response signal including an identification code transmitted from the electronic key in response to the activation signal are properly transmitted and received. In general, it is determined whether or not the electronic key is within a predetermined distance depending on whether the electronic key is within a predetermined distance.In the above-mentioned publication, high sensitivity using a ferrite core is used to secure a predetermined transmission / reception distance. Using a small antenna,
This is attached to the outer handle of the door.

[0003] However, since the ferrite core is considerably expensive, it is desirable to use an air-core antenna to reduce the cost of the entire device.
It cannot be attached to the outer handle.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of this point, and has been made to enable use of a relatively large air-core antenna.

[0005]

In order to achieve the above object, according to the present invention, in a keyless entry device for a vehicle having the above-mentioned structure, a starting antenna for transmitting a starting signal from at least a receiver to an electronic key. Is mounted on the vehicle interior side surface of the vehicle body side pillar located in front of or behind the door, that is, the vehicle body side pillar overlapping the window frame portion of the door. The pillars may be front pillars, center pillars, or rear pillars, but since these pillars can secure a considerably large space compared to the outer handle, such a configuration can be used to attach even relatively large antennas Can be. Moreover, since the interior surface of the pillar inside the cabin is not covered with an iron plate, and the front and rear are glass windows, even when a driver with an electronic key is outside the vehicle, signal waves can be transmitted and received with sufficient sensitivity.

Further, the above antenna is constituted by an air-core coil, and the shortest distance between the coil and the iron plate of the pillar is selected to be 15 mm or more, so that sufficient sensitivity can be obtained.

[0007]

Next, an embodiment of the present invention in which an antenna is mounted on a center pillar will be described. 1 is a schematic perspective view of a vehicle interior showing a portion where an antenna is arranged, FIG. 2 is a plan view of an automobile showing the position of the antenna, FIG. 3 is a cross-sectional view of a center pillar to which the antenna is attached, and FIG. FIG. 5 is an enlarged cross-sectional view of a main part thereof, FIG. 5 is a diagram showing a mounting procedure of the antenna, and FIG.

1 and 2, 1 is a center pillar, 1a is an inner iron plate of a pillar, 1b is an upper pillar cover, 1c is a lower pillar cover, 2 is a front door on the driver's seat side, 2a is a window glass thereof, 3 Is the driver's seat side rear door,
3a is a window glass, 4 is an antenna box containing an antenna, 5 is a vehicle body, and 5a is an outer handle. The illustrated example is for a right-hand drive vehicle, and the antenna box 4 is attached to the right center pillar 1, but may be attached to the passenger seat side, that is, the left center pillar 1.

3 to 6, reference numeral 1d denotes an outer iron plate of the pillar, 1e denotes a mounting recess formed in the upper pillar cover 1b, 6 denotes a seat belt, and 7 denotes an antenna which is used for both starting and receiving. . As shown in FIG. 3, the center pillar 1 has a structure in which pillar covers 1b and 1c made of resin or the like are attached to the inside of two iron plates of an outer iron plate 1d and an inner iron plate 1a, and the antenna box 4 has an upper pillar cover. Dimensions that can be stored in the mounting recess 1e of 1b, for example, width 1
The upper ear piece 4a has a size of about 00 mm, a height of 150 mm, and a depth of about 20 mm.
e, and is fixed to the mounting recess 1e by fixing the lower screw stopper 4b to the screw hole 4d of the mounting recess 1e with a screw 4c. 4e is a connector for connecting the antenna box 4 to a control device (not shown).

In addition to the antenna 7, the antenna box 4 appropriately incorporates a start-up transmission circuit, an identification code discrimination circuit, and the like, and constitutes a keyless entry device integrally with a control device (not shown). As shown in FIG. 6, the antenna 7 is an air-core coil wound on a circular bobbin 7a,
The outer diameter is selected to be the largest dimension that can be stored in the antenna box 4. By the way, when the start signal is transmitted by electromagnetic induction at a frequency of 130 kHz, the diameter of the air-core coil needs to be 80 to 100 mm, but the antenna box 4 having the above dimensions can sufficiently cope with it. When the antenna box 4 is mounted in the mounting recess 1e, the distance A between the shortest portion between the antenna 7 and the inner iron plate 1a of the center pillar 1 is at least 15 mm or more, preferably 20 mm or more.

The operation itself of the keyless entry device according to the present invention is not particularly different from a conventionally known device. That is, when the distance between the antenna 7 and the electronic key (not shown) is within a range in which the start signal and the response signal can be transmitted and received, the lock device is unlocked, and when the distance cannot be transmitted and received, the lock device is locked. . Here, the sensitivity of the antenna affects the possible transmission / reception distance. However, in the illustrated example according to the present invention, the antenna portion is configured as described above, and the antenna 7 is an air-core coil that does not use a ferrite core. Also, the sensitivity of the antenna 7 can be secured to a sufficient value.

That is, since the antenna 7 is mounted on the center pillar 1 having a sufficient space,
The sensitivity can be increased by increasing the coil diameter, and the shortest part of the center pillar 1 between the inner iron plate 1a and
By selecting 5 mm or more, the degree of interference of the radio waves, particularly the radio waves of the start-up signal, with the iron plate is reduced, so that the antenna can be operated without hindrance at the same sensitivity as an antenna using a ferrite core. When a person puts the electronic key in the breast pocket, the antenna 7
Since the height becomes almost the same as the distance and the distance becomes short, it is convenient to obtain sufficient sensitivity.

In such a keyless entry device, the driving of the ignition switch may be controlled by transmission and reception with an electronic key. In this case, the antenna 7 may be used for transmission and reception inside the vehicle compartment. it can. Also in this case, if the electronic key is placed in the breast pocket, the distance from the antenna 7 becomes short, so that it is convenient to obtain sufficient sensitivity.

In the above example, since the antenna 7 is used for both transmitting the start signal and receiving the response signal, only one antenna is required to be mounted. May be provided. The illustrated structure of the center pillar 1 is an example, and an appropriate mounting structure may be adopted for a vehicle having a different structure. In the above example, an example is shown in which an antenna is attached to the center pillar of a four-door car,
The antenna 7 can be attached to a front pillar in front of the front door or a rear pillar behind the rear door.

[0015]

As is apparent from the above description, the keyless entry device of the present invention unlocks the lock device when it is detected that the electronic key is within a predetermined distance from the receiver, and releases the lock device at the predetermined distance. In a keyless entry device for an automobile configured to lock a lock device when it is not detected that the vehicle is located within the vehicle body, at least a start antenna for transmitting a start signal from a receiver to an electronic key is provided on a vehicle body located in front of or behind a door. It is designed to be attached to the interior surface of the pillar on the passenger compartment side.

Therefore, it is easy to mount a relatively large antenna at a position not covered with an iron plate, and a signal is hindered without lowering the sensitivity while using an air-core antenna not using an expensive ferrite core. Data can be transmitted and received without any cost, and the cost of the apparatus can be reduced. In addition, the antenna can be mounted on the pillar without damaging the design.Furthermore, since it is not necessary to wire the antenna to the movable part as in the case where the antenna is mounted on the outer handle of the door, wiring work is easy and door There is no possibility that the wiring will be damaged by opening and closing.

Further, in the case where the above-mentioned antenna is constituted by an air-core coil and the shortest distance between the coil and the iron plate of the pillar is selected to be 15 mm or more, transmission and reception are hardly hindered by the iron plate, and the antenna using the ferrite core is used. It is easy to operate with the same sensitivity as the above without any trouble.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a vehicle interior showing a portion where an antenna of a keyless entry device according to the present invention is disposed.

FIG. 2 is a plan view of the automobile showing a position of an antenna of the above device.

FIG. 3 is a sectional view of a center pillar to which the antenna of the above device is attached.

FIG. 4 is an enlarged sectional view of a main part of the above.

FIG. 5 is a diagram showing a procedure for mounting an antenna in the above device.

FIG. 6 is an explanatory diagram regarding the arrangement of antennas in the above device.

[Explanation of symbols]

 Reference Signs List 1 pillar (center pillar) 1a inner iron plate 1e mounting recess 4 antenna box 5 body 7 antenna

Claims (3)

[Claims] When the electronic key is detected within a predetermined distance from the receiver, the lock device is unlocked, and when the electronic key is not detected within the predetermined distance, the lock device is locked. A keyless entry device for a vehicle, wherein a starting antenna for transmitting a starting signal from at least a receiver to an electronic key is attached to a vehicle interior side surface of a vehicle body side pillar located in front of or behind a door. Entry device. 2. The keyless entry device for an automobile according to claim 1, wherein an activation antenna for transmitting an activation signal to the electronic key is mounted on an inner surface of the center pillar located between the front door and the rear door on the passenger compartment side. 3. The antenna has an air-core coil, and the shortest distance between the coil and the iron plate of the center pillar is 15 mm.
The keyless entry device for an automobile according to claim 1 or 2, which is selected as described above.