JP2014004801A - Resin molded product obtained by integrating metal member and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the airtightness and liquid tightness of the joint between a metal member and a resin member without devising the shape of fine irregularities given to the metal member surface by laser light irradiation without increasing the number of processing steps by laser light irradiation To do.
A resin molded product in which a metal member and a resin member are joined and integrated in the same plane by molding the resin member. On the joint surface of the metal member with the resin member, an aggregate region of grooves having a fine width dimension by laser light irradiation is provided. The groove assembly region is an assembly of closed-loop grooves in which both ends of the grooves are connected to each other, and is configured by arranging similar-shaped grooves at the same center. Each groove is formed by repeating scanning with a laser beam spot a plurality of times so as to go around the groove with a feed pitch smaller than the diameter of the laser beam spot. The adjacent grooves having the same center are separated from each other by continuous protrusions having a fine width dimension of 30% or more of the diameter of the laser beam spot.
[Selection] Figure 3

Description

  The present invention relates to a resin molded product in which a metal member is inserted or outsert, and particularly to a resin molded product in which a part of the metal member is exposed to the outside from a resin member constituting the resin molded product. Moreover, it is related with the manufacturing method.

  Various resin molded products in which a resin member and a metal member are integrated are employed as automobile parts and electrical equipment parts. When the resin molded product is manufactured by, for example, injection molding, in order to secure the bonding strength at the interface between the metal member and the resin member, the surface of the metal member integrated with the resin member is finely irradiated by laser light irradiation. Concavity and convexity are imparted.

Specifically, Patent Document 1 (Japanese Patent No. 4020957) and Patent Document 2 (Japanese Patent Laid-Open No. 2010-167475) disclose the following configurations.
That is, laser scanning is performed on the surface of the metal member in one scanning direction, and laser scanning is performed in another scanning direction that intersects the scanning direction in the same plane (cross-scanning processing). A technique for imparting irregularities to a metal surface is disclosed. The cross-scanning process is performed multiple times in a superimposed manner, and the applied fine unevenness is a concave portion formed in a fine three-dimensional network shape and a convex portion in which at least a part forms a bridge shape or an overhang shape. ing. Here, the bridge shape is a shape in which the tops of the generated convex portions are melted and connected to form an arch shape and a hole is opened in the lower portion.
When the resin material is injection-molded on the metal surface with the fine irregularities described above, the resin material enters the concave portion of the fine three-dimensional mesh shape and the pores below the bridge portion, so that the metal surface (joint surface) and the resin material are in contact with each other. It is said that an extremely high anchor effect can be obtained at the same time as the surface area increases.

  Patent Document 3 (Japanese Patent Laid-Open No. 10-294024) discloses that a metal surface is irradiated with laser light to roughen the surface into a striped, dotted, wavy, knurled, or satin-like uneven shape. It is disclosed. However, Patent Document 3 does not specifically disclose the technique and the roughened surface properties.

  Further, Patent Document 4 (Japanese Patent Laid-Open No. 2008-087409) discloses that a laser beam is irradiated on the surface of a metal material to form a recessed portion having a plurality of fine holes. However, Patent Document 4 does not specifically disclose the technology and the shape of the fine holes.

Japanese Patent No. 4020957 JP 2010-167475 A JP-A-10-294024 JP 2008-087409 A

  Since the techniques disclosed in Patent Document 1 and Patent Document 2 perform cross-scanning processing, the number of processing steps increases.

  The problem to be solved by the present invention is to devise the shape of fine irregularities provided on the surface of a metal member by laser light irradiation, and to increase the airtightness of the joint between the metal member and the resin member without increasing the number of processing steps by laser light irradiation. It is to ensure the property and liquid tightness.

The present invention is directed to a resin molded product in which a metal member and a resin member are joined and integrated in the same plane by molding the resin member.
And, the joint surface of the metal member with the resin member is provided with an aggregate region of grooves having a fine width by laser light irradiation, and the aggregate region of the grooves is a closed loop groove in which both ends of the groove are connected to each other It is an assembly of the above, and each groove having a similar shape is arranged in the same center. Each groove is formed by repeating scanning with a laser beam spot a plurality of times so as to go around the groove with a feed pitch smaller than the diameter of the laser beam spot, and adjacent to the same center. The grooves are separated from each other by continuous ridges having a fine width of 30% or more of the diameter of the laser beam spot (claim 1).
The closed loop groove has a sufficient depth because it is formed by scanning the laser beam spot around the groove multiple times at a feed pitch smaller than the diameter of the laser beam spot. In addition, at the tops of the continuous ridges that separate the adjacent grooves from each other, complicated unevenness is generated by cooling and adhering the metal that has sublimated and scattered when the grooves are formed. These complex irregularities are formed by repeatedly forming fine metal masses that have been sublimated, cooled, and deposited each time scanning around the closed-loop groove is repeated. ing. When the resin member is integrated with the metal member by molding, the resin material penetrates deeply into the groove, and on the other hand, the resin material penetrates into the complicated and fine uneven gaps at the top of the ridges and becomes complicated and fine. Hold the unevenness securely.
In the above, the width of the continuous ridge that separates the grooves from each other in parallel is 30% or more of the diameter of the laser light spot. This is because it is not possible to secure a sufficient width to provide unevenness. The upper limit of the ratio of the width dimension of the ridges to the diameter of the laser beam spot is preferably a value that does not leave a portion of the surface of the metal member that does not have complex and fine irregularities on the top of the ridges. Set. This is determined by the output level of the laser beam, the material of the metal member, and the like.

  In the first aspect of the present invention, each groove constituting the groove collection region may be one selected from a circle, a rectangle, or a polygon (invention 2).

  In the manufacturing method according to the present invention, a joining region between a metal member and a resin member is irradiated with a laser beam to form an aggregate region of grooves having fine widths separated by continuous ridges. The groove collecting region is an aggregate of closed loop grooves in which both ends of each groove are connected to each other, and each groove having a similar shape is arranged with the same center. Each groove is formed by setting the feed pitch of the laser light spot smaller than the diameter of the laser light spot, and repeating scanning with the laser light spot a plurality of times around the groove, with the same center. Adjust the movement pitch distance to the adjacent groove formation so that the continuous ridges of the fine width dimension separating the adjacent grooves from each other remain, and the width of the continuous ridges is set to the diameter of the laser beam spot. 30% or more (Claim 3).

  In the plural times of scanning around the groove by the laser beam spot, first, in order to demarcate the whole area of the groove, a predetermined pitch is moved to the adjacent groove formation every time the laser beam spot is scanned. Thus, it is preferable to repeat the operation of moving to adjacent groove formation and repeat scanning with the same laser beam spot while tracing the same locus (claim 4).

  In the present invention, each groove of the aggregate region of the grooves provided at the joint portion of the metal member performs scanning with the laser light spot a plurality of times so as to go around the groove with a feed pitch smaller than the diameter of the laser light spot. Since it is formed repeatedly and has a sufficient depth, the resin material penetrates deeply into the groove by molding the resin member to ensure high airtightness and liquid tightness at the joint interface Can do. In addition, since the resin material penetrates into the gaps between the complex and fine irregularities generated on the tops of the continuous ridges, and the resin material securely holds the complex and minute irregularities, the metal member and the resin member Bonding strength is also increased. Furthermore, since the scanning direction by the laser beam spot is a direction around the groove, unlike the cross-scanning process shown in Patent Document 1 and Patent Document 2, the number of processing steps can be reduced.

  As in the invention according to claim 2, when each groove constituting the groove collecting region is selected from a circle, a rectangle, or a polygon, the groove collecting region is a ring shape, a rectangle, or a polygon. When the inner shape is exposed from the resin molded product, high airtightness and liquid tightness between the inner side and the outer side of the ring shape or frame shape can be ensured.

In the example equivalent to this invention and the prior art example 1, it is the photograph figure which expanded and showed the aggregate | assembly area | region of the groove | channel of the fine width dimension provided to the joint surface of the metal member. In the example equivalent to this invention and the prior art example 1, it is the photograph figure which expanded and showed the cross section of the junction part of a metal member and a resin member. In the Example which concerns on this invention, and the prior art example 1, the top view ((A) is a metal member in an Example, (B) which showed typically the gathering area | region of the groove | channel of the fine width dimension provided to the joint surface of the metal member ) Is a cross-sectional view of a metal member in Conventional Example 1) and a resin molded product. In the Example which concerns on this invention, it is explanatory drawing which illustrated the positional relationship of the scanning direction by the laser beam spot for groove formation, and the irradiation direction from the light source of a laser beam.

Embodiments of the present invention will be described below with reference to the drawings.
In the resin molded product according to the present invention, the metal member is inserted or outserted, the resin member is injection-molded, for example, and the metal member and the resin member are joined and integrated. When no treatment is applied to the metal member, the metal member and the resin member are simply in contact with each other, and there is no bonding at the interface between them, so that they are easily peeled off. I cannot keep it dense. Therefore, in the present invention, as will be described below, a collective region of parallel fine width grooves formed by irradiating a laser beam is provided on the joint surface of the metal member.

The photographs shown at each scale in the upper example of FIG. 1 are cases where the groove collection region is configured in a ring shape by a collection of parallel grooves, and thus is not an example itself but a photograph corresponding to the example. I refuse to be. Although it is a photograph corresponding to the example, the properties observed in the enlarged photographs (c) and (d) are the same in the embodiment according to the present invention. I will explain.
Each groove (vertical stripe appearing in a black color tone in the photograph) was formed by repeating scanning with a laser beam spot so as to go around the groove multiple times at a feed pitch smaller than the diameter of the laser beam spot. Is. The adjacent grooves are separated from each other by continuous protrusions (longitudinal stripes appearing in a grayish white color tone in the photograph) having a fine width of 30% or more of the diameter of the laser beam spot. Yes.

  The diameter of the laser beam spot is 20 to 100 μm and is usually employed. The scanning feed pitch by the laser beam spot that circulates in the closed loop groove is preferably 10 to 50% of the diameter of the laser beam spot, and the periphery of the irradiated laser beam spot is irradiated with the previous laser beam spot. Adjust so that it partially overlaps the periphery.

  Moreover, the width dimension of the continuous protrusion is set to 30% or more of the diameter of the laser beam spot. In other words, the moving pitch distance in the center direction when moving from one closed loop groove to the next adjacent closed loop groove formation is set to 130% or more of the diameter of the laser beam spot. The width dimension of the ridge is preferably 20 μm or more. However, the width dimension of the ridge is set too large so that the portion of the metal member that does not have complicated and fine irregularities on the top of the ridge does not remain. The condition of the complex and fine irregularities given to the top of the ridge changes depending on the laser beam output, the metal material, etc., so it depends on the laser beam output, the metal member, etc. The upper limit of the width dimension of the ridge is appropriately determined.

  Each of the closed-loop grooves is formed by setting the feed pitch of the laser light spot to be smaller than the diameter of the laser light spot and repeating the scanning around the groove a plurality of times. Here, a plurality of repetitions of scanning around the groove are first performed every time scanning with a laser light spot is performed once (a closed loop groove is turned once) in order to partition the entire groove collection region. A method of repeating the scanning with the same laser light spot while tracing the same locus by repeating the operation of moving a predetermined pitch in the direction and moving to adjacent groove formation is adopted. In this case, the scanning that goes around the groove is repeated a plurality of times to complete the groove formation by repeating the scanning that goes around until a predetermined groove depth is obtained for each groove of one closed loop, and then moves by a predetermined pitch toward the center. Although it does not prevent the adoption of the method of partitioning the aggregate region of the grooves by the method of moving to the adjacent groove forming step, it is preferable to adopt the former method. Further, the movement toward the center by a predetermined pitch may be either movement toward the center or movement away from the center.

As can be understood from the photograph (c) seen from above and the photograph (d) seen from above at an angle of 45 degrees in the upper embodiment of FIG. 1, as a result of the repeated scanning with the laser beam spot, the grooves provided are sufficient. It has a depth, and both the groove wall surface and bottom surface have a relatively uniform and fine uneven shape. On the other hand, the top of the ridge that separates the grooves from each other is extremely complicated because fine metal lumps that are sublimated, scattered, cooled, and deposited each time scanning with a laser beam spot is repeated. And fine irregularities are generated.
The depth of the groove is preferably 50 to 100 μm, and the number of scanning repetitions is determined in consideration of the output level of the laser beam and the material of the metal member.

As shown in FIG. 3A, the collective region 2 of parallel fine width grooves provided on the joint surface of the metal member 1 has, for example, a ring shape. Each groove is formed by the repeated scanning with the laser beam spot described above, and the ring shape partitioned by the aggregate of the grooves is the aggregate area 2 of the grooves. Alternatively, a rectangular or polygonal frame shape partitioned by similar groove aggregates is the groove aggregate region. The ring-shaped or rectangular or polygonal frame-shaped groove collection region may be provided by being surrounded by double or more at the same center.
Then, for example, as shown in FIG. 3C, a resin molded product 4 in which the resin member 3 is integrated on one surface of the metal member 1 is formed. The resin member 3 is firmly bonded to the groove collecting region 2 of the metal member 1.

The photograph of the upper example in FIG. 2 shows the cross section of the joint between the metal member and the resin member in the upper example of FIG. 1 on each scale. This is an enlarged photograph of the cross section in the direction intersecting the groove, the upper part that appears in grayish white color tone is a metal member, and the lower part that appears in black and grayish white spots is a resin member is there. Also, the photograph (b) shows the two rightmost grooves in the photograph (a) in an enlarged manner, the photograph (c) shows the enlarged groove on the left side in the photograph (b), and the photograph (d) shows a photograph ( The right groove in b) is shown enlarged.
As can be understood from the cross-sectional photograph of the upper embodiment of FIG. 2, each groove in the groove assembly region is scanned with a laser beam spot a plurality of times so as to go around the groove with a feed pitch smaller than the diameter of the laser beam spot. Since it is formed repeatedly and has a sufficient depth, the resin material penetrates deeply into the groove by molding the resin member. This contributes to ensuring high air tightness and liquid tightness at the interface of the joint. Moreover, the resin material penetrates into the gaps between the complex and fine irregularities generated at the tops of the continuous ridges, and the resin material surely holds the complex and minute irregularities. This contributes to increasing the bonding strength between the metal member and the resin member. In the example shown in FIG. 3C, the resin member 3 has a cylindrical portion, and the airtightness and liquid tightness between the inner side and the outer side of the cylindrical portion are kept good.

As described above, each of the closed loop grooves is formed by setting the scanning feed pitch by the laser light spot to be smaller than the diameter of the laser light spot and repeating the scanning around the groove a plurality of times. FIG. 4 illustrates the positional relationship between the scanning direction of the laser beam spot 5 for forming a closed loop groove and the irradiation direction of the laser beam from the light source.
FIG. 4A shows the case where the light source is located above the metal member 1 and in the center of the closed loop groove. In this case, as shown in FIG. 4B, the closed-loop groove 6 having a depth direction substantially perpendicular to the surface of the metal member, and the surface of the metal member that separates the adjacent groove 6 from the groove 6. A substantially vertical ridge 7 is formed.
FIG. 4C shows a case where the light source is not located above the center of the closed loop groove. In this case, as shown in FIG. 4D, the adjacent grooves 6 and the ridges 7 separating the grooves 6 are formed in an inclined state with respect to the surface. In this example, a greater bonding strength between the metal member and the resin member can be expected. Further, the aggregate region of the grooves can be divided into arbitrary sections, and the light source can be moved relative to each section, and irradiation can be performed from two or more directions. In this case, the ridges 7 are formed in a state of being inclined in two or more directions with respect to the surface for each section. In this example, a greater bonding strength between the metal member and the resin member can be expected.

  In the present invention, the metal member can be appropriately selected from metal materials such as aluminum, aluminum alloy, copper, copper alloy, steel, and stainless steel according to the purpose and application, and the surface has nickel, tin, chromium, other Metal plating may be applied.

  Further, in the present invention, the resin member can be appropriately selected according to the purpose and use from a resin material such as a thermoplastic resin such as polyphenylene sulfide and ABS resin, a thermosetting resin such as an epoxy resin and a phenol resin, What blended various resin and what added fibrous and granular fillers suitably may be used. In addition, molding means such as injection molding and compression molding can be appropriately employed for molding the resin member.

  Examples of the present invention will be described below in comparison with conventional examples.

〔Example〕
As shown in FIG. 3 (A), a groove aggregate region 2 (ring shape) having a fine width was provided on the surface of the metal member 1 (aluminum plate). The ring has an inner diameter of 8 mm and an outer diameter of 10 mm, and the width dimension of the groove collecting region 2 is 1 mm.
The laser beam to be irradiated is a Yb fiber laser, a wavelength of 1070 nm, and an output of 42 W.
In the scanning with the laser beam spot, the diameter of the laser beam spot was set to 70 μm, and the scanning feed pitch by the laser beam spot circulating around the groove was set to 20 μm. The scanning speed is 1000 mm / second.
Further, the moving pitch distance in the ring center direction (the distance between the centers in the width direction of adjacent grooves) when moving from one closed loop groove to the next adjacent groove formation was set to 100 μm.
Under the above conditions, first, in order to demarcate the entire groove collecting region 2, the laser beam spot moves 100 μm toward the center of the ring every time scanning around the groove is performed, and the next groove formation is started. The same operation was repeated and the same laser beam irradiation scan was repeated 10 times while tracing the same locus. Note that the positional relationship between the scanning direction of the laser beam spot 5 for groove formation and the irradiation direction of the laser beam from the light source was as shown in FIG.
The groove 6 formed as described above has a width of about 55 μm and a depth from the surface of the metal member 1 of about 60 μm. The formed protrusion 7 has a width dimension of about 45 μm and a height from the groove bottom of about 110 μm. The top of the ridge 7 protrudes from the surface of the metal member 1, which is attached to the fine metal lump that is sublimated and scattered and cooled and deposited each time the scanning around the groove by the laser light spot is repeated. (See the cross-sectional photograph (a) of the upper example in FIG. 2).
A resin member 3 (polyphenylene sulfide) was formed on the metal member 1 by injection molding to obtain a resin molded product 4 in which both of the shapes shown in FIG.

[Conventional example 1]
As shown in FIG. 3 (B), a groove aggregate region 2 ′ (ring shape) having a fine width was provided on the surface of the metal member 1 ′ (aluminum plate). The dimensional shape of the ring is the same as in the above embodiment.
This conventional example is different from the above-described embodiment in that the scanning by the laser beam spot is from two directions orthogonal to each other (in this embodiment, only the scanning around the groove of the closed loop) and the scanning by the laser beam spot is repeated. The number of points is 5 times in each direction (in the example, only 10 times of scanning that goes around the closed-loop groove).
In this conventional example, as can be understood from the observation of the enlarged photograph of the lower conventional example in FIG. 1, the orthogonal grooves are not clearly formed by scanning with the laser beam spots from the two orthogonal directions. As a result of the formation of the recessed portion around the periphery, the remaining portion appears as a convex portion (see the photographs (c) and (d) of the lower conventional example in FIG. 1). And the top part of the said convex part remains substantially the same height as the surface of metal member 1 '(refer the cross-sectional photograph (a) of a lower stage conventional example of FIG. 2).

[Conventional example 2]
In the conventional example 1, the width of the ring was set to 3 mm, and the others were the same as in the conventional example 1.

[Conventional example 3]
In the conventional example 1, the width of the ring was set to 5 mm, and the others were the same as in the conventional example 1.

[Conventional Example 4]
In the conventional example 1, a ring having a width of 1 mm is arranged in a concentric manner at intervals of 1 mm, and the others are the same as in the conventional example 1.

The resin molded products of the above examples and conventional examples were subjected to an airtightness / liquidtightness evaluation test.
Airtightness is evaluated by connecting an air pipe to the cylindrical part of the resin molded product, submerging it in water, applying a maximum of 0.6 Mpa higher than the external pressure in the cylinder, and leaking air from the cylinder to the outside of the cylinder. The presence or absence was confirmed.
Liquid tightness evaluation is performed by injecting a penetrant (Microcheck penetrant, manufactured by Taiho Kosai Co., Ltd.) into the cylinder of a resin molded product, and letting it stand for two weeks at room temperature. The presence or absence of dispensing was confirmed.
Table 1 shows a comparison of the results of the above evaluation test and the processing time for providing the groove aggregate region.

  As is apparent from Table 1, in the examples according to the present invention, it can be seen that airtightness and liquid tightness are ensured in a short processing time. When the photographs (c) and (d) of the lower conventional example in FIG. 2 are observed, the concave portion formed by scanning with the laser beam spot has a complicated and fine irregular shape, and an unfilled portion where the resin material cannot enter is confirmed. it can. Although the resin material can hold a complicated and fine concavo-convex shape and can secure a large bonding strength between the metal member and the resin member, the presence of the resin material unfilled portion is particularly insufficient to ensure airtightness. It is guessed.

1, 1 'metal member 2, 2' groove gathering region 3 resin member 4 resin molded product 5 laser beam spot 6 groove 7 ridge

Claims (4)

A resin molded product in which the metal member and the resin member are joined and integrated in the same plane by molding the resin member,
The joint surface of the metal member with the resin member is provided with a collection region of grooves having a fine width by laser light irradiation,
The groove collecting region is an aggregate of closed loop grooves in which both ends of each groove are connected to each other, and each groove having a similar shape is arranged with the same center,
Each groove is formed by repeating scanning with a laser beam spot a plurality of times so as to go around the groove with a feed pitch smaller than the diameter of the laser beam spot,
Adjacent grooves and grooves having the same center are separated by continuous ridges having a fine width of 30% or more of the diameter of the laser beam spot.   The resin molded product according to claim 1, wherein each groove constituting the aggregate region of the grooves is one selected from a circle, a rectangle, or a polygon. A method for producing a resin molded product in which a metal member and a resin member are joined and integrated in the same plane by molding a resin member,
Irradiating a laser beam on the joint surface of the metal member with the resin member to form an aggregate region of grooves having a fine width dimension separated by continuous ridges,
The groove collecting region is an aggregate of closed loop grooves in which both ends of each groove are connected to each other, and each groove having a similar shape is arranged with the same center,
Each groove formation is performed by setting the feed pitch of the laser light spot smaller than the diameter of the laser light spot, and scanning with the laser light spot by repeating the operation of circling the groove a plurality of times,
Adjusting the moving pitch distance to adjacent groove formation so that the continuous ridges with the same fine width separating the adjacent grooves from each other remain, the width of the continuous ridges is adjusted with the laser beam. A method for producing a resin molded product, characterized in that it is 30% or more of the spot diameter.   A plurality of times of scanning with the laser beam spot, first, in order to delimit the entire aggregate region of the groove, every time scanning with the laser beam spot that goes around the groove is performed once, a predetermined pitch is moved to the adjacent groove formation, 4. The method of manufacturing a resin molded product according to claim 3, wherein the operation of moving to adjacent groove formation is repeated, and scanning with the same laser beam spot is repeated while tracing the same locus.