JPH0978907A - Waterproof construction of key with built-in electronic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water from penetrating into a grip part along a key blank in a key having an electronic circuit board within the grip part of the key formed by combining cases. SOLUTION: An electronic circuit board 6 placed on the upper surface of an intermediate case 3 is housed between the case 3 and an upper case 4, and both the cases 3, 4 are adhesively fixed over the whole circumference, a battery 8 provided on the lower surface side of the intermediate case 3 is sealed by an O-ring, and a lower case 5 is screwed to the intermediate case 3, whereby the grip part of a key 1 is formed by each case 3-5. The base end part of a key blank 2 is insert-molded to the middle case 3. Thus, water apt to penetrate into the grip part along the key blank can be surely prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for an electronic circuit built-in key in which an electronic circuit board is provided in a grip portion which is integral with a key blank.

[0002]

2. Description of the Related Art Conventionally, a key for locking and unlocking an automobile is not only inserted into a key cylinder to lock and unlock a door or the like, but also a transmitter / receiver is provided on each of the key and the key cylinder side so that the key can be locked. There is one that can be unlocked without inserting it into the cylinder. When mounting the circuit board on the key side in such a key device,
For example, as disclosed in Japanese Utility Model Publication No. 3-35823, the key gripping portion is composed of a halved case, and the circuit board is housed in the case.

[0003]

By the way, it is necessary to integrate the key blank and the case. However, in the key having the above structure, the key blank is inserted into a slit provided in one of the two divided cases, and the inside of the case is inserted. I fixed the key blank with screws. However, if there is a gap between the key blank and the slit due to a tolerance at the time of molding the case, there is a risk that water will enter the case.

[0004]

In order to solve the above problems and ensure the waterproofness of the key provided with the case for receiving the electronic circuit board in the grip portion, in the present invention, the key is The grip unit, which is integrated with the blank, comprises an intermediate case on which an electronic circuit board for transmitting an unlocking signal is placed, and a pair of outer cases attached so as to sandwich the intermediate case. Insert molding is performed on the intermediate case.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the invention showing specific examples of the present invention will be described in detail below.

FIG. 1 is an exploded perspective view showing a key for an automobile ignition switch as a key with a built-in electronic circuit to which the present invention is applied. As shown in FIG.
The key 1 includes a key blank 2, an intermediate case 3 integrally having the key blank 2, and upper and lower cases 4 and 5 as outer cases attached so as to sandwich the intermediate case 3. Middle case 3 and upper case 4
An electronic circuit board 6 for transmitting an unlocking signal between
And a battery 7 as a power source for the electronic circuit board 6 is received between the intermediate case 3 and the lower case 5. Then, the intermediate case 3 is assembled so as to be received by the upper and lower cases 4 and 5, and the grip portion of the key 1 is formed.

The electronic circuit board 6 is provided with two push button type switches 6a and 6b, and elastic switch covers 4a and 6b are provided at two corresponding positions of the upper case 4.
4b is adhered. For example, in the assembled state, every time the switch 6a is pushed through the one switch cover 4a, the door is locked and unlocked repeatedly, and every time the switch 6b is pushed through the other switch cover 4b, the trunk is locked and unlocked. There is.

According to the present invention, as shown in FIG.
The base end of the key blank 2 is insert-molded in the intermediate case 3. Further, in the illustrated example, the electronic circuit board 6 placed on the upper surface of the intermediate case 3 in FIG. 1 and adhered and fixed by a double-sided tape is covered with the intermediate case 3 and the upper case 4, and the entire circumference of the intermediate case 3 is covered. The adhesive peripheral groove 3a provided as a result is filled with an adhesive, and the peripheral wall 4c provided on the upper case 4 corresponding to the adhesive peripheral groove 3a is fitted into the adhesive peripheral groove 3a as shown in FIG. Then, the intermediate case 3 and the upper case 4 are bonded together.

An engaging piece 3b having a hook portion 5a provided upright in the vicinity of the rear end portion of the lower case 5 at the rear end edge of the intermediate case 3.
The O-ring which is received in the annular groove 3c recessed in the lower surface of the intermediate case 3 while receiving the battery 7 between the intermediate case 3 and the lower case 5 while the intermediate case 3 is embedded in the lower case 5. The intermediate case 3 and the lower case 5 are overlapped with each other so that 10 is compressed and deformed between the lower case 5 and the bottom surface of the lower case 5, and the battery 7 and the electronic circuit board 6 are shielded from the outside. It prevents water from entering between the intermediate case 3 and the lower case 5 from reaching the battery 7 and the electronic circuit board 6. Then, a screw 9 is screwed into the female screw 8 formed in the insert mold portion of the key blank 2 to tighten the intermediate case 3 and the lower case 5 together, and as shown in FIG. And integrate the grip part.

Since the grip portion of the key 1 is formed in this manner, the intrusion of water into the mating surfaces of the upper and lower cases 4 and 5 is prevented.
This can be completely prevented by the bonding state in the bonding circumferential groove 3a and the peripheral wall 4c between the middle and upper cases 3 and 4 and the O-ring 10 between the middle and lower cases 3 and 5, and the base end of the key blank 2 can be prevented. Water that is transmitted and tries to enter the grip portion can be reliably blocked by the insert-molded state of the key blank 1. Further, even if water is flooded into the case from the mating surfaces of the cases 4 and 5 above and below the portion sandwiching the key blank 2, the key blank 2 is molded into the intermediate case 3 received in the cases 4 and 5 above and below. Therefore, it is possible to prevent water from flowing through the key blank 2.

[0011]

As described above, according to the present invention, the intermediate case is sandwiched between the pair of outer cases, and the key blank is insert-molded in the intermediate case at the gripping portion receiving the electronic circuit board in the case. Thus, it is possible to reliably prevent water that travels through the key blank and enters the grip portion, and to ensure waterproofness of the grip portion having a structure in which the electronic circuit board is provided in the grip portion.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an ignition key to which the present invention is applied.

FIG. 2 is an enlarged side cross-sectional view of a main part showing an assembling procedure of an intermediate case and a lower case of an ignition key to which the present invention is applied.

FIG. 3 is an enlarged side sectional view of an essential part showing an assembled state of an ignition key to which the present invention is applied.

[Explanation of symbols]

 1 key 2 key blank 3 middle case 3a peripheral groove 3b engaging piece 3c annular groove 4 upper case 4a / 4b switch cover 4c peripheral wall 5 lower case 5a hook 6 electronic circuit board 6a / 6b switch 7 battery 8 female screw 9 screw 10 O-ring

Claims (1)

[Claims] 1. An intermediate case, on which an electronic circuit board for transmitting an unlocking signal is mounted, and a pair of outer cases mounted so as to sandwich the intermediate case. A waterproof structure for a key with a built-in electronic circuit, wherein the key blank is insert-molded in the intermediate case.