JP6230906B2 - Functional molded parts - Google Patents

Description

  The present invention relates to a functional molded part formed by insert molding a thermoplastic resin on the surface of a metal body.

The following Patent Document 1 shows a secondary battery in which a plurality of single cells are electrically connected by a metal body, and a resin support is integrally provided on the surface of the metal body. The body is fixed to the battery casing. Here, a seal structure is employed in order to prevent liquid and gas from leaking between the battery interiors adjacent to each other through a minute gap between the metal body and the support. In this case, the environment between the single cells is similar to each other, and the required level of sealing performance is not high.
However, when the environments of the spaces on both sides of the seal structure are greatly different and it is desired to prevent liquid or gas in one space from leaking into the other space at a high level, high sealing performance is required. Therefore, in some cases, for example, a groove is formed on the outer circumference of the metal body, a seal material is fitted into the groove, and the seal structure is configured by performing resin insert molding using the metal body as an insert material. Yes.

JP-A-11-120963

However, even with the above-described seal structure, the required sealability may not be maintained when the usage environment is severe, such as a vehicular part, such as a wide use temperature range.
In view of such problems, an object of the present invention is to provide an adhesive strength of a sealing material to the surface of a metal body that requires sealing performance in a functional molded part formed by insert molding a thermoplastic resin on the surface of the metal body. This is to improve the sealing performance between the surface of the metal body and the thermoplastic resin.

The first invention is a functional molded part formed by insert-molding a thermoplastic resin on the surface of a metal body, and is hot at a site where sealability is required between the metal body and the thermoplastic resin. A melt-type adhesive is inserted.
According to the first invention, the hot melt adhesive has a strong adhesive force to the surface of the metal body and is integrated with the thermoplastic resin to be insert-molded. Therefore, the sealing property between the metal body surface and the thermoplastic resin can be maintained at a high level even when the use environment is severe.

A second invention is characterized in that, in the first invention, the thermoplastic resin is a thermoplastic resin that has a higher melting point than the hot melt adhesive and can be melted and compatibilized in the insert molding step. To do.
According to the second invention, the degree of integration between the thermoplastic resin and the hot melt adhesive is increased by compatibilization, and the sealing performance between the metal body surface and the thermoplastic resin is further enhanced.

According to a third invention, in the first or second invention described above, the metal body surface of a portion where sealability is required between the metal body and the thermoplastic resin intersects the direction where sealability is required. An extending groove is formed, and the hot melt adhesive is filled in the groove.
According to the third invention, since the hot melt adhesive is adhered in the concave groove, even if the thermoplastic resin is subjected to insert molding, the hot melt adhesive adheres in the concave groove. In addition, it is not peeled off from the groove during the insert molding process, and is integrated with the thermoplastic resin. Therefore, the sealing property between the metal body surface and the thermoplastic resin can be maintained at a high level even when the use environment is severe.

According to a fourth aspect of the present invention, in the first or second aspect of the invention, the hot-melt adhesive has a shape that spreads at the bottom so as to suppress receiving pressure due to the flow of the thermoplastic resin in the insert molding step. It is bonded to the surface of the metal body.
According to the fourth invention, when a thermoplastic resin is insert-molded into a metal body to which the hot melt adhesive is bonded, the thermoplastic resin flows on the surface of the hot melt adhesive. The agent is suppressed from receiving the flow pressure of the thermoplastic resin due to its flared shape. For this reason, the hot melt adhesive is prevented from flowing during insert molding of the thermoplastic resin. Therefore, the sealing performance between the metal body surface and the thermoplastic resin is maintained.

It is sectional drawing of 1st Embodiment of this invention. It is sectional drawing of 2nd Embodiment of this invention. It is sectional drawing of 3rd Embodiment of this invention. It is sectional drawing of 4th Embodiment of this invention. It is sectional drawing of 5th Embodiment of this invention. It is sectional drawing of the test piece for a sealing performance test.

FIG. 1 shows the structure of an electric wiring portion of an electric motor (not shown) used in an oil mist atmosphere as a first embodiment of the present invention. Here, 40 is the casing of the electric motor, the lower side of the casing 40 in the figure is the space inside the electric motor, and the upper side is the outside of the electric motor. And either the inside or the outside of the electric motor is a space in an oil mist atmosphere. The casing 40 is provided with an opening through which wiring for supplying electricity to the electric motor is passed, and this opening is covered with a polyphenylene sulfite (PPS) resin (corresponding to the thermoplastic resin of the present invention) 30. Three column-shaped conductors (corresponding to the metal body of the present invention) 10 made of NEWM are fixed. The PPS resin 30 is selected as being suitable for the use environment in this embodiment in that it has heat resistance and electrical insulation.
The PPS resin 30 has a flange portion 31 formed on the periphery thereof, and the flange portion 31 is fixed to the casing 40 by bolts 51. Here, in order to ensure the sealing performance between the casing 40 and the flange portion 31, an O-ring 53 is fitted into an annular groove formed on the lower surface of the flange portion 31 so as to surround the three conductors 10. ing. A metal collar 52 is fitted between the bolt 51 and the flange portion 31 so that the tightening force of the bolt 51 is not concentrated on a part of the flange portion 31. Further, an annular recess for receiving the PPS resin 30 is formed on the upper surface of the casing 40, and the labyrinth structure in which the flange portion 31 of the PPS resin 30 is fitted in this recess makes the PPS resin 30 and the casing 40 have a A seal structure is formed between them.

The conductor 10 is formed in a cylindrical shape as a whole, and a concave groove 11 is formed on the outer circumferential circle, and a polyester elastomer hot melt having enhanced adhesion as a hot melt adhesive is formed in the concave groove 11. An adhesive (hereinafter simply referred to as an adhesive) 20 is filled. In addition, crimp terminals 61 and 62 are fastened to the upper and lower ends of the three conductors 10, respectively, and electric wiring of the electric motor is performed.
The PPS resin 30 is molded around the conductor 10 by setting the conductor 10 in a state where the adhesive 20 is filled in the concave groove 11 as an insert material in the mold and filling the PPS resin 30 in the mold. Is done. In this case, as the adhesive 20, a high adhesion grade (GM-955-RK20) of Viroshot (registered trademark) manufactured by Toyobo Co., Ltd. is used. This adhesive 20 is slow in crystallization, highly flexible even at room temperature, and has a property that the adhesive force to the surface of the conductor 10 is uniformly high rather than partially. The PPS resin 30 is a thermoplastic resin that has a higher melting point than the adhesive 20 and can be melted and compatibilized in the insert molding process.

  According to the above embodiment, since the adhesive 20 is adhered in the concave groove 11 of the conductor 10, the adhesive 20 remains in the concave groove 11 even if insert molding of the PPS resin 30 is performed thereon. Even if the PPS resin 30 flows along the axial direction on the outer peripheral surface of the conductor 10 in the process of insert molding, the PPS resin 30 is not peeled off from the concave groove 11 and is compatible with the PPS resin 30 and integrated. It becomes. Therefore, the sealing property between the surface of the conductor 10 and the PPS resin 30 can be maintained even in a severe usage environment, and oil mist is prevented from leaking into the space of the electric motor or outside the electric motor. Can do.

なお、表１中の各試験条件は次のとおり。
初期試験は、成形後、常温状態で所定時間放置したテストピースに対して試験を実施した。
冷熱試験は、上記初期試験で漏れが発生しなかったテストピースに対して、−４０度〜１５０度の温度変化を１０００サイクル繰り返した後に試験を実施した。
油中試験は、１５０度の油の中に５００時間曝した後に試験を実施した。
熱劣化試験は、１５０度の空気中に５００時間曝した後に試験を実施した。
シール性の評価は、導電体１０とＰＰＳ樹脂３０との界面に、２０キロパスカルのヘリウムガスをリークチェックスプレーにより１秒間噴射して、噴射側の反対側から気泡が発生するか否かにより判定した。表１において、気泡が発生しなかった場合を○で示した。
このように本発明の第１実施形態と同等のテストピースによるシール性確認試験の結果、全ての試験条件において各テストピースともシール性に問題のないことが確認できた。 As shown in FIG. 6, a test piece is formed by filling a polyester elastomer hot melt adhesive 20 into a groove 11 on the outer circumference of an aluminum conductor 10 and insert-molding a PPS resin 30 thereon. As a result of conducting a test of sealing properties between the conductor 10 and the PPS resin 30, the results are shown in the following table. Two types of test pieces are prepared. (A) shows only one groove 11 and (B) shows three grooves 11 formed in the axial direction of the conductor 10.

The test conditions in Table 1 are as follows.
In the initial test, the test was performed on a test piece that was left at room temperature for a predetermined time after molding.
The cold test was performed after 1000 cycles of a temperature change of −40 ° C. to 150 ° C. were performed on a test piece that did not leak in the initial test.
The in-oil test was conducted after exposure to 150 degree oil for 500 hours.
The thermal deterioration test was conducted after exposure to 150 degrees air for 500 hours.
Evaluation of sealability is made by determining whether or not bubbles are generated from the opposite side of the injection side by injecting 20 kilopascals of helium gas at the interface between the conductor 10 and the PPS resin 30 with a leak check spray for 1 second did. In Table 1, the case where bubbles were not generated is indicated by ◯.
As described above, as a result of the sealability confirmation test using the test piece equivalent to that of the first embodiment of the present invention, it was confirmed that there was no problem in the sealability of each test piece under all test conditions.

FIG. 2 shows a second embodiment of the present invention. The feature of the second embodiment over the first embodiment described above is that the relative size of the PPS resin 30a and the conductor 10a is changed, and that only one conductor 10a is provided. It is. Other configurations are basically unchanged. That is, in 2nd Embodiment, the conductor 10a is comprised long so that the both ends may protrude from PPS resin 30a. A concave groove 11a is formed on the outer circumference of the conductor 10a, and the concave groove 11a is filled with an adhesive 20a. The shape and size of the concave groove 11a are changed compared to the concave groove 11 in the first embodiment, but exhibit the same performance with respect to the sealing property between the surface of the conductor 10a and the PPS resin 30a. Can do.
The components of the second embodiment may be used alone or in combination of three as in the first embodiment.

FIG. 3 shows a third embodiment of the present invention. A feature of the third embodiment over the second embodiment described above is that the adhesive 20b is bonded to the outer circumference of the conductor 10b by projecting it on the outer circumference without providing a concave groove. is there. Other configurations have not changed. The adhesive 20b that is bonded onto the outer circumference of the conductor 10b is formed in a shape in which both side edges are widened.
According to the third embodiment, when the PPS resin 30b is insert-molded, the PPS resin 30b flows on the surface of the adhesive 20b along the axial direction of the conductor 10b. Since the portion is formed in the shape of the skirt spread, the degree of receiving the flow pressure of the PPS resin 30b is suppressed as compared with the case where the shape of the skirt spread is not formed. Therefore, the adhesive 20b is prevented from flowing during the insert molding of the PPS resin 30b. Accordingly, the sealing performance between the surface of the conductor 10a and the PPS resin 30a is maintained as in the first and second embodiments. Moreover, in the case of the third embodiment, since the conductor 10b is not provided with the concave grooves as in the first and second embodiments, the conductivity of the conductor 10b is not lowered.

FIG. 4 shows a fourth embodiment of the present invention. The feature of the fourth embodiment over the second embodiment described above is that the grooves 11c provided on the outer circumference of the conductor 10c are arranged in three rows. In addition, the shape of one groove 11c is different from the groove 11a in the second embodiment, and is the same as the groove 11 in the first embodiment.
According to the fourth embodiment, since the adhesive 20c is filled in each of the three concave grooves 11c, the sealing property between the surface of the conductor 10c and the PPS resin 30c is further improved as compared with the case of the second embodiment. Enhanced.

FIG. 5 shows a fifth embodiment of the present invention. A feature of the fifth embodiment over the above-described third embodiment is that the adhesive 20d bonded on the outer circumference of the conductor 10d has three rows. The three rows of adhesives 20d are arranged in parallel with each other so as to intersect in a direction that requires sealing performance. One adhesive 20d has a hem-like shape similar to the adhesive 20a in the second embodiment, but has a small dimension in a direction that requires sealability.
According to the fifth embodiment, since the three rows of adhesives 20d are bonded, the sealing performance between the surface of the conductor 10d and the PPS resin 30d is further enhanced as compared with the case of the third embodiment.

As mentioned above, although specific embodiment was described, this invention is not limited to those external appearances and structures, A various change, addition, and deletion are possible in the range which does not change the summary of this invention. For example,
1. The functional molded part of the present invention is not limited to the conductor portion of the electric wiring portion of the electric motor as in the above embodiment. It can be applied to parts that need to seal two different spaces such as oil and air, and is widely applied to waterproof connectors consisting of an insulating part and a conductive member, a terminal part of a computer built-in housing, a battery electrode part, etc. it can. When the component is an electrical component, the current that is energized is not particularly limited from a weak current that transmits an electrical signal to a strong current for driving the motor.
2. In the above embodiment, a polyester elastomer hot melt adhesive is used as the hot melt adhesive, but a polyamide adhesive may be used.
3. The concave grooves may be formed by forming two rows of convex portions in parallel on the surface of the metal body and forming a concave groove between the pair of convex portions.
4). As the thermoplastic resin, in addition to the PPS resin, a resin such as polybutylene terephthalate (PBT), polyphthalamide (PPA), or syndiotactic polystyrene (SPS), or a liquid crystal polymer may be used.

10 Conductor (metal body)
11 Concave groove 20 Polyester elastomer hot melt adhesive (hot melt adhesive)
30 Polyphenylene sulfite (PPS) resin (thermoplastic resin)
40 Casing 51 Bolt 52 Collar 53 O-ring 61, 62 Crimp terminal

Claims (3)

A functional molded part constituted by insert molding of a thermoplastic resin on the surface of a metal body, wherein a hot melt adhesive is provided at a site where a sealing property is required between the metal body and the thermoplastic resin. Is inserted,
On the surface of the metal body where sealing performance is required between the metal body and the thermoplastic resin, a concave groove extending in a direction that requires sealing performance is formed, and the thermoplastic resin is It is located along the surface of the metal body so as to cover the groove, and the hot melt adhesive is filled in the groove, and the hot melt adhesive adheres to the inner wall of the groove. And a functional molded part integrated with a portion of the thermoplastic resin that covers the concave groove . A functional molded part constituted by insert molding of a thermoplastic resin on the surface of a metal body, wherein a hot melt adhesive is provided at a site where a sealing property is required between the metal body and the thermoplastic resin. Is inserted,
The hot melt adhesive is bonded to the surface of the metal body in a shape of spreading at the bottom so as to suppress the pressure accompanying the flow of the thermoplastic resin in the insert molding step. Functional molded parts to do. In claim 1 or 2 ,
The functional molded part, wherein the thermoplastic resin is a thermoplastic resin having a higher melting point than the hot-melt adhesive and can be melted and compatibilized in the insert molding process.

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