JPH0781433B2 - Key with built-in electronic circuit and its molding method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a key having an electronic circuit incorporated in a grip portion, and particularly to a key structure suitable for increasing torsional strength and eliminating damage to electronic circuit components. And the molding method.

[Conventional technology and its problems]

Conventionally, a key having an electronic circuit built therein is formed by insert molding a key plate 100 as shown in FIG.
10 has a space 120 for accommodating the circuit. In this key plate 100, the key is weak in strength because the plate expansion portion 140 that is continuously provided from the insertion portion 130 hangs only on a part of the grip. Especially when turning the key
If a strong twisting force acts on the grip, the key will break.

Further, in a vehicle key device that communicates information by magnetically coupling a key and a key cylinder to control an object, for example, an engine is driven, as shown in FIG.
Is arranged in the key plate 200, when magnetic coupling is performed between the ring coil 220 and the key coil 210, the magnetic flux a created by the ring coil passes through the key plate before flowing into the key coil 210. As a result, magnetic flux causes an eddy current in the metal key plate, which causes a loss of magnetic energy. Due to this loss, the resonance energy on the key side decreases, and the Q of the resonance circuit decreases. Therefore, resonance does not occur sharply, and S /
N ratio gets worse.

Further, when the grip portion is resin-molded, in the normal high-pressure molding, the electronic parts of the grip portion are separated due to the pressure at the time of molding, and the grip portion does not function. For this reason, low-pressure molding must be used, but this method has the problems of low productivity, poor external appearance, post-treatment, and extremely high cost.

An object of the present invention is to provide a key device having a high torsion strength and a high Q value in a key device for exchanging information by magnetic coupling.

Yet another object is to provide a method of molding a key that improves the productivity while incorporating electronic circuit components without damage.

[Means for Solving the Problems]

In order to achieve the above object, the present invention is a key of a device for exchanging information by magnetic coupling between a key and a key cylinder, which includes a key coil which is integrated through a part of a key plate and is substantially U-shaped. A grip part in which an electronic circuit is built in, an expansion part located at the grip part and continuing to the insertion part of the key plate, a plate extension part extending from both ends of the expansion part, the expansion part and the plate extension part. And a notch formed at a position facing the ring coil of the key cylinder between the key cylinders, and the core portions at both ends of the key coil are located in the notch.

According to a preferred embodiment, the electronic circuit including the key coil is sandwiched between the upper holder and the lower holder.

Further, the molding method of the present invention is a key which is integrated through a part of a key plate and has a grip portion in which an electronic circuit is built in the storage space of the key plate, which is incorporated in the storage space of the key plate. The surroundings of the electronic circuit are covered with low pressure primary molding, and then the grip portion is formed by high pressure secondary molding.

[Action]

When the key is turned, the twisting stress applied to the grip portion is dispersed in the plate extension portion, so that the key is not broken.

Further, since no metal portion is interposed between the key coil and the ring, no eddy current flows in the key plate when the magnetic circuit is formed, so that the Q value does not decrease and a sharp resonance can be obtained. Judgment becomes easy.

Also, by protecting the components of the electronic circuit by low-pressure primary molding and then molding the external shape in high-voltage secondary molding, damage to the above-mentioned components is eliminated and the appearance is beautiful.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. First
The figure is a block diagram of the key of the present invention.

The key plate 1 is composed of an insertion portion 2 to be inserted into the rotor on the key cylinder side and a head portion 4 for accommodating an electronic circuit component 3, such as an inductor and a capacitor. The head portion 4 of the key plate is formed in a shape in which the center is removed as shown in FIG. 2 or in a shape in which a part thereof is released as shown in FIG. That is, the key plate 1
Is composed of a plate expansion part 5 following the insertion part 2 and plate extension parts 6 and 7 extending from both ends of the plate expansion part and facing each other. The storage space 8 for electronic circuit components is surrounded on all sides in the key plate shown in FIG. 2, and in the one shown in FIG. 3, the side portion facing the enlarged plate portion is open.

The plate enlarging portion 5 is provided with key coil positioning portions 9 and 10 which will be described later and are orthogonal to the insertion portion. The positioning portion is open from approximately the middle to the outside including the side end surface of the plate expansion portion, and a notch is provided between the plate expansion portion and the plate extension portion at a position facing the ring coil of the key cylinder. A portion (a in the figure) is formed. The core portions at both ends of the U-shaped key coil are located in the cutout portion.

The key coil 20 is composed of a bar core made of ferrite, a winding provided on the bar core, and a resonance circuit including electronic circuit parts. As shown in FIG. 4, the bar core 21 is a core portion at both ends that is magnetically coupled to the key cylinder.
22 and 23 are fitted into the positioning portions 9 and 10 by aligning with the notch portion a of the key plate.

The electronic circuit component 3 is arranged on a printed circuit board, and is incorporated in the key plate storage space 8 via the printed circuit board. After the key plate, the key coil, and the printed circuit board are assembled, they are sandwiched by the holders from both sides of the key plate to integrate the three parts.

The holder is composed of a resin upper holder 30 and a lower holder 40.

The upper holder 30 has a first portion 32 on which the printed circuit board is located and the key coil 20 are located on the inner side surrounded by the ribs 31 on the three sides, and a second portion 33 is formed by cutting out the winding portion of the key coil. A pair of bosses 34a and 34b for attachment are formed between these two parts. Reference numeral 35 is a stopper that is in contact with the inner surface of the key coil and restricts the movement of the key coil.

The lower holder 40 is formed in a frame shape in which a portion facing the first portion 32 of the upper holder is removed, and a lower rib 41 matching the upper rib 31 is formed on the inner edge of the frame, and the lower rib is opened. A thick portion 42 is provided at the end. The thick portion 42 is provided with a hole 43, and the boss of the upper holder is press-fitted into this hole to integrate the both holders.

The front surface of the thick portion is brought into contact with the outer surface of the key coil and regulates the movement in the key insertion direction by the cooperation of the stopper of the upper holder.

Here, a procedure for assembling each component will be described. The key coil and the printed circuit board are connected in advance, and the printed circuit board is arranged in the first portion of the upper holder and the key coil is arranged in the second portion. After mounting the key plate, the lower holder is covered over the key plate and the boss of the upper holder is press-fitted into the hole of the lower holder.

The grip portion 50 is configured by covering an electronic circuit component incorporated in the head portion 4 of the key plate with a resin material. Especially when the grip part is completely molded,
Since the plate extension allows a large amount of the portion where the key plate and the resin are in contact with each other, it is possible to provide sufficient strength against twisting, and further, it is excellent in water resistance and impact resistance.

According to this embodiment, the core portions 22 and 23 at both ends of the key coil are
As shown in FIG. 7, since is located outside the metal portion, there is little energy loss and a sharp resonance is obtained when the key coil 20 and the ring coil 220 are magnetically coupled.

Next, the molding of the grip portion will be described.

FIG. 8 is a process drawing of forming the grip portion on the key plate. The figure shows the plane of the key.

First, the electronic circuit component is assembled to the key plate (state of FIG. (A)), and the entire periphery of this electronic circuit component is covered by low pressure primary molding (state of FIG. (B)). This allows
The electronic circuit components do not fall apart and are held in place.
Further, the grip portion is formed by covering the entire primary molding portion with high pressure secondary molding (state of FIG. (C)).

According to this molding method, since no high voltage is applied to the electronic circuit parts, no damage occurs.

〔The invention's effect〕

As described above, according to the present invention, since the plate extension portions extending from both ends of the enlarged portion of the key plate are provided, the twisting stress applied to the key is dispersed in the plate extension portion, and the key is not broken.

Further, since the key plate (metal part) is not interposed between the key coil and the ring coil, loss of magnetic energy during magnetic coupling is prevented. Further, by making the key coil U-shaped, the coupling distance with the ring coil can be shortened. Therefore, the magnetic coupling becomes dense and the S / N ratio for detecting the resonance point can be increased.

Further, according to the molding method of the present invention, during high-pressure molding, damage to electronic circuit parts is eliminated, and primary and secondary molding can be performed continuously with one molding machine, improving productivity. Can be made.

Further, by performing the secondary molding at high pressure, the appearance can be finished neatly.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, (a) is a plan view, (b) is a sectional view taken along the line I-I, FIG. 2 is a key plate, and (a) is a plan view. , (B) is a side view, FIG. 3 is a plan view showing another embodiment of the key plate, FIG. 4 is a bar core of a key coil, (a) is a plan view,
(B) is a front view, FIG. 5 shows an upper holder,
(A) is a plan view, (b) is a sectional view taken along line II-II, FIG. 6 shows a lower holder, (a) is a plan view, and (b) is III-.
A sectional view taken along line III, FIG. 7 is a view for explaining the action of the key coil of the present invention, FIG. 8 is a process drawing of the key forming method of the present invention, and FIG.
The figure shows a conventional key structure. (A) is a side view showing a partial cross section, (b) is a plan view, and FIG. 10 is a diagram for explaining the influence of a key plate on a magnetic circuit. 1 …… Key plate, 5 …… Plate expansion part, 6,7 ……
Plate extension part, 8 ... Storage space, 9, 10 ... Positioning part, 20 ... Key coil, 30 ... Upper holder, 40 ......
Lower holder, 50 …… Grip part.

Claims (3)

[Claims] 1. A key of an apparatus for exchanging information by magnetic coupling between a key and a key cylinder, which incorporates an electronic circuit including a substantially U-shaped key coil integrated through a part of a key plate. Grip part,
An enlarged portion located at the grip portion and continuing from the insertion portion of the key plate, a plate extension portion extending from both ends of the enlarged portion, and a ring coil of the key cylinder between the enlargement portion and the plate extension portion. A key having a built-in electronic circuit, comprising a notch formed at a position facing each other, wherein core portions at both ends of the key coil are located in the notch. 2. An electronic circuit including a key coil is sandwiched between an upper holder and a lower holder.
The listed key. 3. The key plate is integrated through a part of the key plate,
A key provided with a grip portion in which an electronic circuit is housed in a storage space of the key plate, wherein a periphery of the electronic circuit incorporated in the storage space of the key plate is covered by a low pressure primary molding, and then a high voltage is formed. A key molding method that forms the grip by subsequent molding.