JP3149742B2 - Structure and molding method of key with built-in electronic circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and a molding method for a key with a built-in electronic circuit, and more particularly to a key for a key with a built-in electronic circuit in which a grip portion of the key has a built-in electronic circuit covered with a hard resin and a soft resin. It relates to a structure and a molding method.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 3-27957
As disclosed in No. 2, a vehicle key having a built-in electronic circuit in a grip portion is known. In the above-mentioned conventional key, after a holder for holding an electronic circuit is disposed on a grip portion of a metal key plate, first, the electronic circuit portion is covered by low-pressure primary molding with a low molding pressure, and then a high-pressure mold with a high molding pressure is applied. It is manufactured by forming a grip portion having a desired shape by subsequent molding. According to this molding method, the grip portion of the key can be formed by insert molding without directly applying a high molding pressure to the electronic circuit.

[0003]

However, according to the above-described molding method, the electronic circuit built in the grip portion is subjected to thermal stress during both the primary molding and the secondary molding. In particular, at the time of primary molding, a high-temperature resin is guided directly to the outer periphery of the electronic circuit, so that a large thermal stress acts on the electronic circuit. In this sense, the above-described molding method has a disadvantage that the electronic circuit is easily damaged in the key manufacturing process.

[0004] The thermal stress acting on the electronic circuit built in the key is suppressed by forming a case having a space for inserting the electronic circuit by primary molding and then performing secondary molding after inserting the electronic circuit into the case. can do.
From the standpoint of protecting the electronic circuit from impact, the harder the case formed by primary molding, the better. When a hard resin is used as the material of the case in order to satisfy such demands, there is sufficient electronic space in the case for the physique of the electronic circuit so that an undue stress does not act on the electronic circuit due to thermal deformation of the case. It is necessary to form a circuit insertion space.

[0005] When such a dimensional allowance is given to the electronic circuit insertion space, the electronic circuit inserted into the case can be easily moved in the insertion space of the case. In this case, if the secondary molding is performed without restricting the position of the electronic circuit, the electronic circuit may fall off the case during the secondary molding. Therefore, when adopting a structure in which an electronic circuit is inserted into a case made of hard resin, it is necessary to take measures to prevent the electronic circuit from falling off.

If the secondary molding is performed while the insertion space provided in the case is opened, high-temperature resin flows into the case from the opening, and gives a large thermal stress to the electronic circuit. Therefore, in order to suppress the thermal stress acting on the electronic circuit, it is desirable to take measures for preventing the resin from flowing into the case before performing the secondary molding.

[0007] The above two requirements, that is, the requirement for preventing the electronic circuit from falling off and the requirement for preventing the resin from flowing into the case, correspond to the opening of the insertion space for the electronic circuit with the lid prior to the secondary molding. Both can be satisfied by closing. However, the case, the electronics,
In addition, some dimensional errors occur in the lid and the like due to manufacturing. Therefore, in order not to apply undue stress in any case to the electronic circuit housed in the space divided by the case and the lid, it is necessary to allow a certain amount of play in the electronic circuit. Will be.

As described above, in manufacturing a key with a built-in electronic circuit, it is possible to prevent the electronic circuit from falling off in the key manufacturing process, to suppress the thermal stress acting on the electronic circuit in the key manufacturing process, Satisfies all requirements, such as protecting the surrounding area with hard resin, incorporating the electronic circuit in the key without play, and preventing undue stress from acting on the electronic circuit due to thermal deformation. This has been difficult in the past.

The present invention has been made in view of the above points, and has an object to close an opening of a space into which an electronic circuit is to be inserted by using a lid made of a thermoplastic resin having elasticity. Accordingly, an object of the present invention is to provide a structure and a molding method of a key with a built-in electronic circuit that solve the above-mentioned problems.

[0010]

The above object is achieved by the present invention.
As described in the above, the structure of the electronic circuit built-in key incorporating the electronic circuit in the grip portion of the key, a hard resin portion having an electronic circuit insertion space into which the electronic circuit is inserted,
A lid portion made of a thermoplastic resin having elasticity and disposed at an opening of the electronic circuit insertion space, and a soft resin portion covering the hard resin portion and the lid portion ;
First, when the soft resin portion is molded, the lid portion softens and
This is achieved by the structure of the electronic circuit built-in key formed so as to be in close contact with the electronic circuit.

The above object is also a method of forming an electronic circuit built-in key in which an electronic circuit is built in a grip portion of the key, wherein the electronic circuit insertion space into which the electronic circuit is inserted is provided. A hard resin molding process of molding a hard resin portion including: an electronic circuit insertion process of inserting the electronic circuit into an electronic circuit insertion space of the hard resin portion,
After the electronic circuit is inserted, a lid arranging step of arranging a lid made of a thermoplastic resin having elasticity in the opening of the electronic circuit insertion space, so that the lid is heated. Forming a soft resin portion covering the hard resin portion and the lid portion , and at the time of forming the soft resin portion,
The lid is formed so as to soften and adhere to the electronic circuit.
And a soft resin molding step.

In the first and second aspects of the present invention, the electronic circuit is inserted into an electronic circuit insertion space provided in the hard resin portion. The electronic circuit insertion space is closed by the lid after the electronic circuit is inserted. When the soft resin portion is molded, the lid portion includes:
The heat and the molding pressure that accompany the molding of the soft resin portion act. Since the lid is made of a thermoplastic resin,
It softens in a heated environment. Therefore, when heat and a molding pressure act on the lid during molding of the soft resin portion, the lid is deformed so as to be in close contact with the electronic circuit. For this reason, at the time of completion of the molding of the soft resin portion, a state is formed in which the electronic circuit is held without play in a space divided by the lid portion and the electronic circuit insertion space. Since the lid has elasticity,
Even if thermal deformation occurs in the hard resin portion or the like, no undue stress acts on the electronic circuit.

[0013]

FIG. 1 is a front view of an electronic circuit built-in key 10 according to an embodiment of the present invention. An electronic circuit built-in key (hereinafter, simply referred to as a key) 10 includes a metal key plate 12, a hard resin portion 14 covering a grip portion of the key plate 12, and an electronic circuit insertion space 16 formed in the hard resin portion 14. A transponder 18 to be inserted, a lid 20 for closing an opening of the electronic circuit insertion space 16, and a soft resin portion 22 for covering the hard resin portion 14 are provided.

The hard resin portion 14 protects the transponder 18 housed therein from impact, and prevents the grip portion of the key 10 from being unduly greatly deformed when a twisting torque is applied to the grip portion. This is a part formed in order to prevent The material of the hard resin portion 14 is a resin having high hardness, for example, PBT (Polybutylene Terephtal).
ate) and the like.

The transponder 18 has a predetermined I
It is a chip element having a built-in electronic circuit for serially transmitting a signal including a D code. Transponder 18 is key 1
When 0 is inserted into the key cylinder, the above signal is transmitted to the anti-theft device mounted on the vehicle. The antitheft device makes the vehicle movable only when the ID code included in the signal transmitted from the transponder 18 matches a predetermined code.

The lid 20 is a member for closing the opening of the electronic circuit insertion space 16 from outside the transponder 18, and is made of an elastic thermoplastic resin. In this embodiment, a polyester elastomer having a melting point of 154 ° C. is used as a material of the lid 20.

The soft resin portion 22 imparts a soft feeling to the grip portion of the key 10, and in particular, reduces the impact given to the driver when the driver touches the key grip portion, and This is a portion formed to reduce the impact acting on the grip portion. In order to achieve these objects, the soft resin portion has a thickness of 2 mm or more. As the material of the soft resin portion 22, an elastic and flexible resin, for example, vinyl chloride or the like is used.

Referring to FIGS. 2 to 7, the key 10
The structure and molding method of the above will be described in detail. FIG. 2 shows a side view of the key plate 12 and the hard resin portion 14. Also,
FIG. 3 shows the key plate 12 and the hard resin portion 14 as shown in FIG.
FIG. 3 is a cross-sectional view taken along the line III-III shown in FIG.

As shown in FIG. 3, the key plate 12 is an L-shaped metal plate having a long shaft portion 12a in which a key groove is formed and a short shaft portion 12b covered with the hard resin portion 14. By providing the short shaft portion 12b, the rotational torque applied to the grip portion of the key 10 is effectively transmitted to the long shaft portion 12a. In addition, of the key plate 12,
A through hole 12c is provided at a position substantially at the center of the grip portion of the key 10.

As shown in FIG. 3, the hard resin portion 14 is formed so that the through hole 12c is not closed. FIG.
As shown in FIG. 3, the hard resin portion 14 is provided with an electronic circuit insertion space 16 opened on the side surface thereof.
The width W and the height H of the electronic circuit insertion space 16 are set such that values larger than the physique of the transponder 18 by a predetermined value are secured. The above-mentioned predetermined value is determined when the hard resin portion 14 and the transponder 18 undergo any thermal deformation and deterioration with time, and the dimensions of the hard resin portion 14 and the transponder 18 vary within the tolerance range. Is set to a value that does not cause interference between the electronic circuit insertion space 16 and the transponder 18. For this reason, the transponder 18 inserted into the electronic circuit insertion space 16 does not receive an unduly large stress from the hard resin portion 14.

After the step of forming the hard resin portion 14 on the grip portion of the key plate 12 is completed,
As shown in FIG. 4, the transponder 18 is inserted into the electronic circuit insertion space 16 of the hard resin portion 14. On one side of the electronic circuit insertion space 16 facing the opening,
A bent surface 16a is formed. On the other hand, a bent surface 18a is also formed on one side surface of the transponder 18. When a pressing force is applied to the transponder 18 from the opening side of the electronic circuit insertion space 16, the position of the transponder 18 is corrected to a position where the bent surfaces 16a and 18a are in close contact with each other. The bent surfaces 16a and 18a are formed such that the transponder 18 is positioned at the center of the electronic circuit insertion space 16 in the width W direction when both are brought into close contact with each other.

When the step of inserting the transponder 18 into the electronic circuit insertion space 16 is completed, a step of attaching the lid 20 to the opening of the electronic circuit insertion space 16 is performed. FIG. 5 shows a front view of the lid 20. FIG. 6 is a cross-sectional view when the lid 20 is cut along the line VI-VI shown in FIG.

The lid 20 is mounted on the opening of the electronic circuit insertion space 16 so that the surface shown in FIG. The lid 20 has a slightly larger size than the width W and the height H of the opening of the electronic circuit insertion space 16. Therefore, when the lid 20 is attached to the opening of the electronic circuit insertion space 16, the electronic circuit insertion space 16 is closed. Lid 20
A lightening portion 20a is formed at the center of the surface on the side in contact with the transponder 18. When the lightening portion 20a is formed, the heat capacity of the lid portion 20a decreases, so that it is possible to raise the temperature of the lid portion 20a with a smaller amount of heat than when the lightening portion 20a is not formed. Become. Further, when the lightening portion 20a is formed, the strength of the peripheral portion 20b of the lid portion 20, that is, the strength of a portion that comes into contact with the peripheral portion of the transponder 18 decreases, so that the lightening portion 20a is not formed. In comparison with the above, a large deformation can be easily applied to the peripheral edge portion 20b of the lid portion 20.

When the step of attaching the lid 20 to the opening of the electronic circuit insertion space 16 is completed, the hard resin 1
A secondary molding process for forming the soft resin portion 22 covering the fourth resin member 4 is performed. FIG. 7 shows a state where the hard resin portion 14 and the like are set in a molding die 24 used in the secondary molding step.

The molding of the soft resin portion 22 is performed by injecting a heated vinyl chloride resin into a molding die 24. Therefore, high temperature and high pressure act on the hard resin portion 14 set inside the molding die 24 in the process of forming the soft resin portion 22. On the other hand, in the present embodiment, the lid 20 is attached to the opening of the electronic circuit insertion space 16 before the soft resin 22 is molded. For this reason, the electronic circuit insertion space 16
However, despite the fact that the transponder 18 is larger than the physical size of the transponder 18, the transponder 18
Does not fall out of the electronic circuit insertion space 16.
Further, the high-temperature vinyl chloride resin guided into the molding die 24 is prevented from proceeding by the lid 20, and does not flow into the electronic circuit insertion space 16. Therefore, the thermal stress acting on the transponder 18 during the process of forming the soft resin portion 22 is suppressed.

In this embodiment, the molding of the soft resin portion 22 is performed at a molding temperature of 170.degree. As described above, the lid 20 is made of an elastic thermoplastic resin, specifically, a polyester elastomer having a melting point of 154 ° C. Therefore, the lid portion 20 is temporarily in a softened state during the process of molding the soft resin 22.

The molding die 24 is, as shown in FIG.
A gate 26 for injecting resin is provided near the position where 0 is arranged. The resin guided to the molding die 24 has the highest temperature in the vicinity of the gate 26, and has a lower temperature as the distance from the gate 26 increases. Therefore, if the gate 26 is provided near the lid 20 as in the present embodiment, high-temperature resin can be guided near the lid 20,
The lid 20 can be effectively softened. Further, as described above, the heat capacity of the lid portion 20 is suppressed low by providing the lightening portion 20a. For this reason, the lid 20
In the process of molding the soft resin portion 22, it can be sufficiently softened.

In the process of molding the soft resin portion 22, a molding pressure is applied to the lid portion 20 to press the lid portion 20 toward the inside of the electronic circuit insertion space 16. When the molding pressure acts on the lid 20 in a state where the lid 20 is softened, the lid 20 comes into close contact with the transponder 18, and the peripheral portion 20 b of the lid 20 contacts the side wall of the electronic circuit insertion space 16 with the transponder 18. 18 is formed. For this reason, when the molding of the soft resin portion 22 is completed, the transponder 22 is fixed without any play in the space divided by the lid portion 20 and the electronic circuit insertion space 16.

As described above, when the force for pressing the transponder 18 into the electronic circuit insertion space 16 acts, the position of the transponder 18 is corrected to the center of the electronic circuit insertion space 16 in the width W direction. . Therefore, in an environment where a molding pressure accompanying the molding of the soft resin portion 22 acts on the lid portion 20, the transponder 18 is located at the center of the electronic circuit insertion space 16 in the width W direction, that is, the transponder 18 It is fixed at a position that does not interfere with the side wall of the space 16. Further, the polyester elastomer constituting the lid portion 20 is a member having appropriate elasticity even at room temperature. Therefore, if the hard resin portion 14 is deformed due to heat or aging, the deformation of the lid portion 20 ensures that the deformation is absorbed. For this reason, according to the key 10, while the outer periphery of the transponder 18 is covered with the high-strength hard resin portion 14 that is resistant to impact, stress caused by deformation of the hard resin portion 14 and the like is generated.
Can be prevented.

As shown in FIG. 7, the molding die 24 for molding the soft resin portion 22 does not have a core inserted into the through hole 12c of the key plate 12. Therefore, the soft resin portion 2
The vinyl chloride that constitutes No. 2 also enters the inside of the through hole 12c. In the present embodiment, PBT used as the material of the hard resin portion 14 and vinyl chloride used as the material of the soft resin portion 22 have characteristics that are difficult to adhere to each other. Therefore, simply covering the outer periphery of the hard resin portion 14 with the soft resin portion 22 cannot control the displacement between the soft resin portion 22 and the hard resin portion 14. On the other hand, according to the present embodiment, when a part of the soft resin part 22 is penetrated into the through hole 12c penetrating the key plate 12 and the hard resin part 14, the hard resin part 14 and the soft resin part 22 is connected at substantially the center of the grip portion of the key 10, so that an unduly large displacement between the hard resin portion 14 and the soft resin portion 22 can be prevented.

In the above embodiment, the transponder 18 corresponds to the electronic circuit according to the first and second aspects. By the way, in the above embodiment, polyester elastomer is used as the material of the lid 20, but the present invention is not limited to this. That is, the lid is
When the hard resin portion 14 is subjected to thermal deformation or the like, the hard resin portion 14 has elasticity enough to prevent improper stress from acting on the electronic circuit, and can be manufactured from a resin having thermoplastic characteristics. it can. Further, in the above embodiment, the molding temperature of the soft resin portion 22 is set to be higher than the melting point of the material forming the lid portion 20, but the present invention is not limited to this. . That is, the molding temperature of the soft resin part is
It is sufficient that the temperature be higher than the temperature sufficient to soften the lid, and it is not necessary to exceed the melting point of the material of the lid.

[0032]

As described above, according to the first and second aspects of the present invention, during the manufacturing process of the key, the electronic circuit falls off from the hard resin portion, and the high-temperature resin flows around the electronic circuit. Can be prevented. Further, the electronic circuit built in the hard resin portion can be held without play in a space divided by the electronic circuit storage space and the elastic lid portion. Therefore, according to the first and second aspects of the present invention, it is possible to prevent the electronic circuit from falling off during the manufacturing process of the key, to suppress the thermal stress acting on the electronic circuit during the manufacturing process of the key, Satisfies all requirements such as protecting the electronic circuit with a hard resin, incorporating the electronic circuit into the key without play, and preventing undue stress from acting on the electronic circuit due to thermal deformation. it can.

[Brief description of the drawings]

FIG. 1 is a front view of an electronic circuit built-in key according to an embodiment of the present invention.

FIG. 2 is a side view of a key plate and a hard resin part which are components of the electronic circuit built-in key according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a key plate and a hard resin portion, which are components of an electronic circuit built-in key according to one embodiment of the present invention, taken along a line III-III shown in FIG.

FIG. 4 is a cross-sectional view showing a state in which a transponder is inserted into a hard resin portion of the electronic circuit built-in key according to one embodiment of the present invention.

FIG. 5 is a front view of a lid which is a component of the electronic circuit built-in key according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view of the cover, which is a component of the electronic circuit built-in key according to the embodiment of the present invention, taken along a line VI-VI shown in FIG. 5;

FIG. 7 is a view showing a state in which a key plate, a hard resin portion, and the like, which are components of a key with a built-in electronic circuit, according to an embodiment of the present invention, are set in a molding die for a soft resin portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electronic circuit built-in key 12 Key plate 14 Hard resin part 16 Electronic circuit insertion space 18 Transponder 20 Lid 22 Soft resin part 24 Molding die

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-279572 (JP, A) JP-A-7-238722 (JP, A) JP-A-7-317391 (JP, A) JP-A 8- 135263 (JP, A) JP-A-8-184227 (JP, A) JP-A-8-284495 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) E05B 19/00 E05B 49 / 00

Claims (2)

(57) [Claims] 1. A structure of an electronic circuit built-in key in which an electronic circuit is built in a grip portion of the key, wherein the hard resin portion has an electronic circuit insertion space into which the electronic circuit is inserted, and a thermoplastic resin having elasticity. A lid portion disposed in an opening of the electronic circuit insertion space, and a soft resin portion covering the hard resin portion and the lid portion , and, when molding the soft resin portion, The lid is
A structure of a key with a built-in electronic circuit, which is formed so as to be softened and adhere to the electronic circuit. 2. A method for molding an electronic circuit built-in key in which an electronic circuit is built in a grip portion of the key, the method comprising: forming a hard resin portion having an electronic circuit insertion space into which the electronic circuit is inserted; An electronic circuit insertion step of inserting the electronic circuit into the electronic circuit insertion space of the hard resin portion, and after the electronic circuit is inserted, the opening of the electronic circuit insertion space is made of a thermoplastic resin having elasticity. A lid disposing step of disposing the lid , and forming the soft resin part covering the hard resin part and the lid so as to heat the lid , and
At the time of molding the resin part, the lid part softens and
A method of molding a key with a built-in electronic circuit, comprising: a soft resin molding step formed so as to be in close contact therewith .