JP6611466B2 - Metal part-resin bonding method and metal part-resin integrated molding - Google Patents

Description

  The present invention relates to a method for joining a metal part and a resin and an integrally molded product of the metal part and the resin.

  An integrally molded product of a metal part and a resin is manufactured, for example, by injecting a molten resin onto the surface of the metal part. In order to strengthen the bonding between the metal part and the resin, a method of forming fine irregularities on the surface of the metal part prior to the injection of the molten resin has been proposed as described in Patent Documents 1 and 2. . In Patent Document 1, micron-level irregularities are formed on a metal surface by pressing using a mold having fine irregularities formed thereon. In Patent Document 2, nano-level fine holes are formed on the metal surface by chemical treatment (chemical etching). By filling molten resin into fine recesses formed by these methods, the adhesion at the metal / resin interface can be enhanced by the anchor effect (throwing effect).

  In Patent Document 3, in order to obtain a desired bonding strength with little variation in the bonding strength between the metal and the resin due to the anchor effect, the axis of the metal substrate surface is inclined at a predetermined angle with respect to the perpendicular to the metal substrate surface. A method of forming a plurality of inclined holes and filling the inclined holes with a resin composition has been proposed.

JP 2012-64880 A Japanese Patent No. 4903881 JP 2009-51131 A

  In Patent Document 1, the metal surface is roughened by pressing, the contact area between the resin and the contact angle is increased, and the contact angle is randomized to increase the bite between the metal and the resin. Since it is not mechanical joining by the anchor effect like 3, the joining force in the peeling direction becomes a problem. Furthermore, it is necessary to form microscopic irregularities on the press mold, which complicates the manufacture of the mold, makes it difficult to duplicate, and deteriorates and determines the mold.

  As described in Patent Document 2, when micron-level fine irregularities and nano-level micropores are formed on a metal surface to give an anchor effect, a high initial adhesive strength can be obtained. The anchor effect due to fine unevenness and fine holes is that when an integrally molded product of metal parts and resin is subjected to thermal and mechanical repetitive stress such as heat cycle, the fine anchor part is broken due to breakage of resin part or resin creep. It is assumed to deteriorate due to loss of function. For example, since a metal and a resin have different linear expansion coefficients, a large thermal stress is generated at the interface between the two due to a temperature change. In general, since a resin has a larger linear expansion coefficient than that of a metal, thermal stress resulting from a difference in the linear expansion coefficient between the resin and the metal increases in an environment with a temperature change. For this reason, there is a possibility that interface peeling between the surface of the metal part and the resin occurs due to heat shock.

  In addition, when the molten resin does not sufficiently flow into fine irregularities and fine holes during insert molding, it is assumed that the bonding force is reduced or deteriorated. Therefore, special molding conditions are required such as increasing the temperature of the molten resin and increasing the injection pressure during insert molding in order to facilitate the flow of the resin into fine irregularities and fine holes. As a result, an increase in manufacturing cost, addition of device functions, generation of resin burrs, deterioration of shape accuracy, and the like can be problems.

  Furthermore, a chemical wet process (etching process) and its pre-treatment process are necessary for the metal surface, and the cost, lead time, environmental load, and the like are problems. In addition, there is a problem that the storage period from the etching process to the resin molding is limited.

  In Patent Document 3, an inclined hole having an opening diameter of about 0.05 to 1 mm and a depth of about 0.5 to 5 mm is formed. In Patent Document 3, when subjected to a heat cycle, thermal stress is generated between the resin and the metal due to the difference in linear expansion coefficient, but the fine irregularities and micropores described in Patent Documents 1 and 2 Unlikely, it is considered that the anchoring effect by the resin filled in the inclined hole and the inclined hole on the surface of the metal part is hardly deteriorated.

  However, in Patent Document 3, since the anchor effect is obtained by the holes, it is necessary to form a large number of inclined holes in order to obtain a desired bonding strength between the metal and the resin. In Patent Document 3, in order to obtain stable bonding, a large number of inclined holes having different inclination directions are formed. For example, inclined holes having different inclination directions are formed annularly on the surface of the metal part. It is difficult to easily form a large number of inclined holes having different inclination directions. Further, since the inclined hole is a closed hole, it is difficult to reliably fill the resin. Due to the air layer remaining in the blocking hole, there is a concern about the occurrence of peeling due to temperature change.

  An object of the present invention is to make it difficult for the bonding strength between a metal part and a resin to deteriorate even when subjected to a heat shock, and to relatively easily bond the metal part and the resin by an anchor effect. An object of the present invention is to provide a method for joining resin and resin and an integrally molded product of metal part and resin.

The present invention forms a press groove inclined with respect to a normal to the metal part surface by press working on the surface of the metal part , flows a resin into the metal part surface on which the press groove is formed, joins the metal part and the resin , The press working is performed so as to push in the overhang portion of the press groove formed on the surface of the component .

According to the present invention, even when subjected to a heat shock, the bonding strength between the metal part and the resin is hardly deteriorated, and the metal part and the resin can be bonded relatively easily by the anchor effect.
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

The schematic diagram of the joining cross section of the metal component and resin for demonstrating the concept of this invention. The figure explaining an example of the formation method of the press groove | channel in this invention. The figure explaining the formation condition of the press groove | channel in this invention. The figure explaining the formation condition of the press groove | channel in this invention. The perspective view of the metal component explaining the formation condition of the press groove | channel in this invention. The figure explaining another example of the formation method of the press groove | channel in this invention. The figure explaining the example of the shape of the press groove | channel in this invention. The figure explaining the example of the shape of the press groove | channel in this invention. The figure explaining the formation condition of the press groove | channel in the other Example of this invention. The figure explaining the formation condition of the press groove | channel in the other Example of this invention. The figure explaining the formation condition of the press groove | channel in the other Example of this invention. The figure explaining the formation condition of the press groove | channel in the other Example of this invention. The figure explaining the formation condition of the press groove | channel in the other Example of this invention. The figure explaining the example of a shape of the pushing part formed in the press groove | channel in the other Example of this invention.

Embodiments of the present invention will be described below with reference to the drawings.
The resin basically does not have chemical bonding with the metal member, and the interface between the two easily peels off due to thermal stress and mechanical stress generated between the metal part and the resin. For this reason, a method for strongly integrating the metal component surface and the resin by the anchor effect is required. The present invention makes it difficult for the bonding strength between the metal part and the resin to deteriorate even when subjected to repeated stress such as heat shock, and allows the metal part and the resin to be bonded relatively easily by the anchor effect. To do.

  The concept of the present invention will be described based on Example 1. A first embodiment will be described with reference to FIGS.

  In this embodiment, a press groove inclined with respect to the normal to the metal part surface is formed by pressing on the surface of a metal part (a metal part such as aluminum), and resin (normal injection) is formed on the surface of the metal member on which the press groove is formed. A thermoplastic resin composition, polyphenylene sulfide resin (PPS resin, etc.) used for molding is poured, and the metal part and the resin are joined. In addition, resin pouring is performed by inserting a metal part in which a press groove is formed in a mold and injecting the resin into the mold, as in normal injection molding.

  In this embodiment, in order to fix the resin to the surface of the metal part by the anchor effect, a press groove inclined by pressing is formed on the surface of the metal part. As shown in FIG. 1, a press groove 1g inclined on the surface of the metal part 1 is formed by pressing as described later, a resin is poured into the surface of the metal part, and a resin filling portion 3f is formed in the inclined press groove 1g. . Since the press groove 1g is inclined, an overhang portion 5 having an overhang amount O is formed in the press groove 1g. An anchor effect is obtained by the overhang portion 5. This anchor effect can be effectively exhibited by a unique configuration of the press groove 1g formed by press working as described later.

FIG. 2 shows a method of forming the inclined press groove 1g. 3 and 4 are enlarged schematic views showing the formation state of the inclined press groove 1g.
As shown in FIG. 2, the grooving blade (press tool) 2 is driven to be inclined with respect to the surface of the metal part 1.
Specifically, as shown in FIG. 3, the grooving blade 2 is driven into the surface of the metal part 1 at an inclination angle α with respect to the perpendicular 1 p with respect to the metal part surface 1 s. When the grooving blade 2 is driven into the surface of the metal part 1, the overhang portion is raised (rolled up) and a raised portion (protrusion) 1r is formed. The raised portion 1r increases the overhang amount O and enhances the anchor effect. Further, the raised portion 1r has an effect of preventing relative movement between the resin 3 and the metal part surface 1s.

  Further, since the grooving blade (press tool) 2 is somewhat elastic, as shown in FIG. 4, the grooving blade tip 2t is elastically deformed when driven into a metal part. The grooving blade 2 illustrated by the dotted line in FIG. 4 shows the case where the grooving blade tip 2t is not elastically deformed, but actually, as illustrated by the solid line in FIG. The blade tip 2t is elastically deformed to the surface side of the metal part. Thus, the grooved blade tip 2t is positioned on the raised portion 1r side by the length of M. Therefore, it means that the overhang amount O becomes larger. Further, the inclination angle of the formed press groove 1g is also increased. In addition, the size of the bulge of the bulge 1r becomes larger. As a result, the anchor effect can be obtained more effectively.

  Conventionally, it was difficult to form a bag-like (ridge-shaped) anchor portion in a groove formed by press working, and it was considered difficult to form an anchor portion by press working. As described above, it has been found that the anchor effect can be obtained by forming the inclined grooves by press working.

  Further, unlike the fine irregularities and fine holes described in Patent Documents 1 and 2, since the inclined press groove 1g becomes a large anchor portion (concave portion), the resin can be poured into the press groove 1g without fail, Unlike a fine structure, the structure is maintained even when subjected to a heat shock. Therefore, the anchor structure of the present embodiment is resistant to heat shock, and even when subjected to heat shock, the bonding strength between the metal part and the resin is unlikely to deteriorate.

  The inclined press groove 1g is formed to have a groove depth D of about 0.2 mm and a groove entrance width W of about 0.2 mm, for example, when the thickness of the metal part 1 is about 0.4 mm. Is done. Further, the angle β of the tip of the grooving blade (press tool) 2 is about 30 degrees, and the grooving blade 2 is driven into a metal part with an inclination angle α of about 35 to 55 degrees. If the inclination angle α is large, the grooved blade 2 may slide up with respect to the metal component surface 1s depending on the metal, and if it is small, a sufficient anchor effect cannot be obtained. In addition, these are illustrations and this invention is not limited to these.

  FIG. 5 shows a metal part 1 having an inclined press groove 1g formed in this way on the surface. As shown in FIG. 5, in order to obtain a sufficient anchor effect, the groove length L2 of the press groove 1g is made sufficiently large. For example, the length L2 of the press groove 1g with respect to the length L1 of the surface of the metal part 1 is at least about half. Thereby, unlike an inclined hole, an anchor part for obtaining a desired joint strength can be formed by a relatively simple operation, and the metal part and the resin can be joined relatively easily by the anchor effect. It becomes possible.

  Further, unlike the inclined hole, the press groove having the groove length as shown in FIG. 5 can be reliably and easily filled with resin, and no air layer remains in the press groove. The joining of the metal part and the resin by the anchor effect can be easily made strong.

  In FIG. 5, a pair of parallel press grooves 1g are formed on the surface of the metal part 1, but the present invention is not limited to this. In order to effectively obtain the anchor effect, it is preferable to form a plurality of inclined press grooves, and the plurality of inclined press grooves are, for example, presses orthogonal to each other in addition to the press grooves in a parallel relationship. A groove, a press groove having an oblique relationship, a press groove formed at random, and the like are conceivable. Further, the press groove 1g may be formed in a curved shape instead of a linear shape in the groove length direction.

  In FIG. 2, the press groove 1g is formed by moving the grooving blade 2 obliquely (moving linearly) with respect to the surface of the metal part. However, as shown in FIG. The grooving blade 2 may be moved in a circular arc shape with the rotation center 2c as the rotation center to be struck against the surface of the metal part. In this case, the raised portion (protrusion) 1r rises more. Thereby, the effect of preventing the relative movement between the resin 3 and the metal part surface 1s by the raised portion 1r is improved. Such an effect of preventing movement becomes more effective when the press groove 1g has a length different from the hole as shown in FIG. Such an effect can hardly be expected with an inclined hole.

  In the embodiment shown in FIGS. 2 and 6, two grooving blades 2 are simultaneously driven into the metal component surface. In addition, the direction in which the two grooving blades 2 are driven obliquely oppose each other (the moving components in the horizontal direction oppose each other). By doing in this way, when driving the grooving blade 2 against the metal component surface, it becomes possible to suppress the movement of the metal component 1, that is, the displacement of the metal component 1 with respect to the grooving blade 2, The inclined press groove 1g can be reliably press-formed.

7 and 8 show examples of various press groove shapes.
In the above example, the inclined press grooves 1g are opposed to each other (the grooves are formed inward), but the inclined press grooves 1g are formed in a direction away from each other as shown in FIG. (The groove is formed outward). FIG. 7B shows an example in which the outward press groove 1g is formed in the same manner as in FIG. However, it is difficult to form such press grooves at the same time, and forming the two press grooves inward is superior in workability. In FIG. 7C, an outward press groove 1g1 is formed on the inner side, and an inward press groove 1g2 is formed on the outer side thereof. Thus, the anchor effect becomes more reliable by forming many press grooves.

FIG. 8 shows another example of the shape of the press groove.
The tip (bottom) of the press groove can have any shape, and for example, it may be a flat surface as shown in FIG. 8 (a) or a curved surface as shown in FIG. 8 (b). In short, a press groove inclined so as to form an overhang portion may be press-molded. Further, as shown in FIG. 8C, the inclination angles of the two press grooves may be made different. Moreover, as shown in FIG.8 (d), it is good also as what provided the metal component protrusion part 10 instead of the plane on the surface of the metal component 1. FIG. In other words, any shape may be used, such as a shape other than a plate shape, a bent plate, a shape by another processing, and the like. In FIG. 8D, a groove forming surface 11 that is orthogonal to the driving direction is provided in order to facilitate driving of the grooving blade 2. In this case, the surface of the metal part serving as a reference for the perpendicular is not the groove forming surface 11 but is indicated by reference numeral 1s. FIG. 8E shows a case where press grooves 1gT and 1gU are formed on both surfaces of a metal part, and resins 3T and 3U are bonded to both surfaces, respectively.

  The press operation for forming the press groove 1g in this embodiment is the formation of micro holes by etching or the like, and is one of the processes such as bending and punching of the metal parts pressing process (such as progressive die pressing process). It can be incorporated and can be inlined into the progressive die press process.

  Another embodiment of the present invention will be described with reference to FIGS. The present embodiment is based on the first embodiment, and the description of the contents described in the first embodiment is omitted.

  In this embodiment, a bag-like space is formed in the press groove 1g by crushing (pressing) the overhang portion 5 (the raised portion 1r) in the inclined press groove 1g formed in the first embodiment. is there. Specifically, press working (indentation) is performed in a direction intersecting with the longitudinal direction of the press groove 1g so as to crush the press groove 1g formed on the surface of the metal part.

  9, FIG. 10 (A), FIG. 10 (B), FIG. 10 (C), and FIG. 10 (D) show a method of forming the press groove 1g in this embodiment. FIG. 10 (A) shows the shape of the press groove 1g after the grooving blade is driven obliquely, and FIG. 10 (B) shows the state where the raised portion 1r of the press groove 1g is pushed from above. 10 (C) shows an example of the shape of the press groove after pressing, and FIG. 10 (D) shows the pressing portion in an enlarged manner.

  FIG. 9A and FIG. 10A show a state in which the press groove 1g is formed by pressing with the grooving blade 2 as in the first embodiment. At this time, as described above, the raised portion 1r (overhang portion 5) is formed. As shown in FIG. 10B, the raised portion 1r (overhang portion 5) is pushed downward from above using a pushing portion forming tool (press tool) 4. FIG. 9C to FIG. 9E show the pressing state.

  The pushing of the raised portion 1r (overhang portion 5) may be stopped in the state shown in FIGS. 9C and 9D, and the tip of the overhang portion 5 is a groove as shown in FIG. You may push it in until it contacts the other side. If pushed deeper than the metal surface, a bag-like space with a high anchor effect is formed in the press groove.

  FIG. 10C shows a state where the push-in portion 1d is formed, and FIG. 10D shows an enlarged main portion thereof. In this example, only one point is pushed in at a pin point, and the pushing is made to the same height as the metal surface. In this way, a part of the press groove 1g in the longitudinal direction is crushed to form a pushing portion 1d. A bag-like space is formed around the pushing portion 1d.

  As shown in FIG. 9D, when the pushing is stopped in a situation where the tip of the overhang portion 5 does not contact the opposite side of the groove, the pushing amount is adjusted so that the groove width w is about 30 μm, for example.

  As shown in FIG. 9 (e), when the overhang portion 5 is pushed in until the tip of the overhang portion 5 contacts the opposite side of the groove, the portion to be pushed and crushed is partial with respect to the length of the groove, so that the opening is wide. However, since the resin flows from there, there is no particular problem from the viewpoint of filling the resin into the bag-like space, and on the other hand, an improvement in the anchor effect can be expected.

In FIG. 11, the example of a shape of the pushing part formed in a press groove | channel is shown.
FIG. 11A shows the pushing portion d as one point, which is the same as that shown in FIGS. 10A to 10D. FIG. 11 (b) shows several pushing parts. If there are many pushing parts, an anchor effect will improve more. FIG. 11 (c) shows a case where a part of the press groove 1g in the longitudinal direction is pushed in, and FIG. 11 (d1) shows a case where the whole part is pushed. In the case of FIG. 11D, in order to flow the resin into the bag-like space, the amount of pushing is adjusted so that a gap (opening) 1a is formed as shown in FIG. 11D2. On the other hand, in the case where the pushing portion is partial, in addition to stopping pushing in the middle as shown in FIG. 11 (e), the tip of the overhanging portion is brought into contact with the opposite side of the groove as shown in FIG. 11 (e2). Anyway. Even if the gap is further pushed in as shown in FIG. 11 (e2), the gap (opening) 1a may be ensured in the peripheral area of the crushing.

  The present invention can be applied to metal parts and resin integrated molded products having various uses and shapes, and can be used for various applications such as industrial equipment, automobiles, aircraft equipment, consumer products, and household appliances. It is applicable to typical mechanical parts. For example, a resin-made electronic circuit protective case member having a metal conductive terminal therein, a resin-made cover partially having a metal electromagnetic shield, a heat radiating plate, and the like.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Metal part, 1a ... Gap part, 1d ... Push-in part, 1g, 1g1, 1g2, 1gT, 1gU ... Press groove, 1p ... Perpendicular, 1r ... Raised part, 1s ... Metal parts surface, 2 ... Grooving blade (press tool), 2t ... Grooving blade tip, 2c ... Grooving blade rotation center, 3,3T, 3U ... Resin, 3f ... Resin filling part, 4 ... Push-in part forming tool (press tool), 5 ... Overhang part, 10 ... Metal part protruding part, 11 ... Groove forming surface.

Claims (5)

A metal part-resin joining method that integrates a metal part and resin,
A press groove inclined with respect to a perpendicular to the surface of the metal part is formed by pressing on the surface of the metal part, and the resin is poured into the surface of the metal part on which the press groove is formed, and the metal part and the resin And
A method of joining a metal part and a resin, wherein pressing is performed so as to push in an overhang portion of the press groove formed on the surface of the metal part. In the joining method of the metal component and resin of Claim 1 ,
The method of joining a metal part and a resin, wherein the overhang portion is pushed in by pushing a part of the press groove in the longitudinal direction. In the joining method of the metal component and resin of Claim 2 ,
The method of joining the metal part and the resin is characterized in that the overhang portion is pushed in such a manner that the tip of the overhang portion contacts the opposite side of the press groove. An integrally molded product of metal parts and resin,
The metal part and the resin are joined by an anchor effect,
A press groove inclined with respect to a perpendicular to the metal part surface is formed on the metal part surface where the metal part is bonded to the resin, and an overhang portion is formed in the press groove,
The resin has a filling portion filled in the press groove,
The metal part and resin integral molded product, wherein the overhang portion is pushed into a part of the press groove in the longitudinal direction. In the integrally molded product of the metal part and the resin according to claim 4 ,
A raised part is formed on the overhang part so as to rise from the surface of the metal part.

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