JPH0480482A - Key device - Google Patents

Abstract

PURPOSE:To prevent the breaking of a circuit element by electrically connecting an external terminal to a key body through a Zener diode. CONSTITUTION:When a key body 1 is inserted into the key cylinder of a car door under the state in which a finger is brought into contact with a push-button 8, static electricity charged on a human body is made to flow through the key body 1 through a grounding plate 13, and falls to a ground 16 on the car body side. When the key body 1 is inserted into the door cylinder of the car under the state in which the finger is brought into contact with a charging terminal 10a, the static electricity of the human body is made to flow through the key body 1 through Zener diodes 12a, 14 and the grounding plate 13, and falls to the ground 16.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides an electric circuit such as a transmitting circuit for locking and unlocking a locking device in a resin case provided in the grip of a mechanical key body. The present invention relates to a key device that is housed therein.

(Prior Art) This type of key device has already been proposed in, for example, Japanese Utility Model Application Publication No. 115466/1983, and is well known. This type of key device has a push button exposed on the surface of the case.
By pressing this push button, a wireless signal is transmitted to remotely lock/unlock a locking device of a vehicle or the like.

(Question to be solved by the invention! II) By the way, when the key body is inserted into the key cylinder when the human body is charged with static electricity, even if the key gripping part is made of a resin case with relatively high dielectric strength, Regardless of the situation, a surge current may flow from the human body to the vehicle body through the metal key.

One of the reasons for this is thought to be that, since the push button portion is made of flexible thin rubber or the like, discharge is discharged into the key body through the thin wall portion of the push button.

If the transmitting circuit is placed close to the pushbutton, the surge current may flow into the transmitting circuit, destroying the IC chip or other circuit elements and damaging the function of the key device. There is. Additionally, if the key device has an external terminal that is electrically connected to the vehicle, such as a charging terminal, this external terminal has an exposed structure and is connected to the electrical circuit of the key device. Furthermore, when a discharge occurs from the human body to an external terminal, a surge current flows into the transmitting circuit, and in this case, the same problem as described above also occurs.

(Means for Solving the Problems) The present invention aims to solve the above-mentioned problems in the prior art, and as a means thereof, provides a key body and a grip portion of the key body. A case made of resin, an electric circuit housed in the case, and an external terminal for electrically connecting the electric circuit to a vehicle-side circuit when the key body is inserted into a key cylinder. In the key device,
The external terminal is electrically connected to the key body via a Zener diode.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a plan sectional view of the key device according to the present invention, FIG. 2 is a side sectional view thereof, and FIG. 3 is an explanatory diagram of the operation of the key device according to the present invention.

As shown in FIGS. 1 and 2, a circuit board 3 is attached to the key body 1 over both sides of its base 2, and a resin case is placed over the entire surface of the circuit board Fi. 4
is installed. The circuit board 3 is made of a flexible film-like printed circuit board on which electronic components such as an IC chip 5 incorporating a transmitting circuit and the like and a push button switch 6 for operating the transmitting circuit are mounted. It is folded so as to cover both sides of the base 2. Then, on the surface opposite to the surface on which the IC chip 5 etc. are mounted,
A power supply unit including a built-in battery 7 that can be charged and discharged is formed.

A push button 8 made of flexible rubber is exposed on the surface of the case 4, and the pressing force applied to the push button 8 is applied via a disk spring 15 to the push button 8. The signal is transmitted to the button switch 6. In addition, the case 4
has a pair of light emitting diodes 17a and 17b in its front part.
are provided, and the light emitting diodes 17a, 17b are electrically connected to the transmitting circuit. Then, by pressing the pushbutton 8, a transmission circuit is activated via the pushbutton switch 6, and an infrared code signal is transmitted from the light emitting diodes 17a and 17b by the output signal of the transmission circuit, and the locking device on the vehicle side is activated. can be locked and unlocked remotely.

As shown in FIGS. 1 to 3, a pair of charging terminals 10a and 10b are exposed at the base of the key body 1, and the key body 1 is inserted into the ignition key cylinder of the vehicle. When moved to the on position, the charging terminals lOa and 10b are connected to the terminal on the ignition key cylinder side, and as a result, the voltage of the vehicle battery is applied to the built-in battery 7 of the key body l, and the built-in battery 7 is activated. It is supposed to be charged. In addition, charging terminal 10
a.

10b is attached to the key body l with insulating resins 11a and llb interposed therebetween. The charging terminal 10a10b is connected to four diodes 12 arranged on the circuit board 3.
It is connected to the built-in battery 7 through a rectifier circuit consisting of a, 12b, 12c, and 12d, so that the polarity of the charging voltage is constant regardless of the direction in which the key body l is inserted into the ignition key cylinder. Here, the diode 12a,
12b is a Zener diode, charging terminal 10a,
When a voltage of a certain value or higher is applied from 10b, a current flows in the opposite direction.

Inside the case body 4, a donut-shaped ground plate 13 is arranged close to the lower end of the push button 8, and the ground plate 13 has three leg pieces 13a, 1
3b and 13c are formed. And the leg piece 13a
, 13b are provided in direct contact with the key body 1, and the leg piece 13c is soldered to one end of a Zener diode 14 arranged on the circuit board 3. The other end of this Zener diode 14 is connected to the negative side of the charging circuit, which allows the surge current from the charging terminal 10a to flow to the key body 1 via the earth plate 13. Current is prevented from flowing to the earth plate 13.

Next, the operation of this embodiment will be explained.

When the key body l is inserted into the key cylinder of the vehicle door with a finger in contact with the push button 8, the static electricity charged on the human body is transferred to the inside of the case 4 through the thin part of the push button 8 (see Fig. 2). However, this static electricity flows to the key body 1 via the ground plate 13, and finally falls to the ground 16 on the vehicle body side (arrow A in Figure 3). 1 is inserted into the door cylinder of a vehicle, the static electricity charged on the human body flows to the key body 1 via the Zener diodes 12a, 14 and the ground plate 13, and finally falls to the ground 16 on the vehicle body ( In the case of the charging terminal 10b, it falls to the ground 16 in the same way.

In this way, the static electricity that has been charged on the human body hardly flows into the transmitting circuit or the like, so that the circuit elements are not destroyed.

In the above embodiment, the Zener diode 14 connected to the charging terminal 10a is connected to the key body 1 via the ground plate 13, but the structure is not limited to this. The key body 1 may be connected directly to the key body 1 without going through the key body 13.

(Effects of the Invention) With the above-described configuration, the present invention prevents static electricity charged on the human body from flowing into the electric circuit of the key device when the key body is inserted into the key cylinder, so that the circuit elements It has an excellent effect in that it will not be destroyed and the function of the key device will be impaired.

[Brief explanation of the drawing]

FIG. 1 is a plan sectional view of the key device according to the present invention, FIG. 2 is a side sectional view thereof, and FIG. 3 is an explanatory diagram of the operation of the key device according to the present invention. 1...Key body 3...Circuit board 4.
...Case 5...IC chip 6...
・・Push button switch 7・・Built-in battery 8・・・・
Push buttons 10a, 10b...Charging terminal 13...Earth plate 14...Zener diode

Claims (4)

[Claims] (1) A key body, a resin case provided in the grip of the key body, and an electric circuit housed within the case;
In the key device, the external terminal is electrically connected to the key body via a Zener diode. A key device characterized in that it is connected to a key. (2) A switch section for controlling the electric circuit is provided on the surface of the case, and an earth plate is provided inside the case near the bottom of the switch section and electrically connected to the key body, and the Zener 2. The key device according to claim 1, wherein a diode is connected to the key body via the ground plate. (3) The key device according to claim (2), wherein the electric circuit includes a transmitting circuit that remotely locks and unlocks a locking device on the vehicle side by transmitting a wireless signal by operating the switch section. . (4) The key device according to claim 1, wherein the electric circuit includes a charging circuit that is supplied with power from a vehicle-side power source via an external terminal and charges the key device-side power source.