JP2012111103A - Method of bonding sheet molding compound (smc) molded product to metal fitting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bonding method that can eliminate the need of a bonding jig when bonding metal fittings to an SMC molded product, and can reduce man hours.SOLUTION: In a method of bonding the SMC molded product to the metal fittings, adhesives are provided between an SMC molded product and the metal fittings, and the metal fittings are fixed to the SMC molded product and bonding curing is carried out. In this bonding method, the SMC molded product has a convex (protrusion) part or a concave (recess) part and a pin shape; the metal fittings have a hole or a convex (protrusion) part which contact to the convex (protrusion) part or the concave (recess) part, and has one or more opening parts with convex (protrusion) shape of the shape of one or more pairs of flat springs which fits to the pin shape; and a gap with flat spring convex (protrusion) shape of the opening part is narrow to width of the fitting pin shape.

Description

  The present invention relates to a method for bonding an SMC molded product and a metal fitting.

  In automotive parts, when mounting a resin molded product to a frame or body, clips, nuts, bolts, etc. are often pre-assembled to a sheet molding compound (hereinafter SMC) molded product. A seat is provided on the molded product. However, since this mounting seat causes sink marks in the molded product, it cannot be made thick and structurally has low rigidity and strength. For this reason, it is common to integrate metal parts by joining such as welding, fusing, and adhesion at a portion where high strength is required.

  Applications of SMC molded products are mainly for residential and automotive applications, but the characteristics of automotive SMC molded products are that they have a beautiful appearance comparable to steel plates, and have a higher specific rigidity than steel plate products ( It is light when it is made to have the same bending rigidity as a steel plate product, it is relatively easy to form complex shapes that are difficult to plate with steel plate products, and the product cost is high, but the mold cost is low. Suitable for manufacturing.

  Currently, automotive SMC molded products are mainly used for outer panels such as hoods, fenders, and spoilers, but the rigidity and strength of the mounting part with the vehicle body are important characteristics, minimizing cost increase. It is necessary to maintain or improve these characteristics while limiting to the limit. As a means to improve the rigidity and strength, there is a method in which a hole is formed in the molded product and a bolt is passed through the hole and the metal fitting is tightened with a nut, and the bolt or nut is exposed on the surface of the molded product. It cannot be used for the outer plate that is important.

  In addition, there is a method of applying an adhesive to the back of the molded product and attaching and attaching a metal fitting to it. However, adhesion processing occurs after molding, and removal of surface irregularities due to adhesion treatment and shrinkage of the adhesive The cost is increased due to the time required. In contrast to these methods, as a method of attaching the convex metal fittings to the back surface while maintaining the appearance, there is a method of insert-molding fastening convex metal fittings such as bolts and nuts. It cannot be used when you want to use it. When using a clip, a convex bracket is required to fix the clip to the molded product. However, it has been difficult to attach the bracket to the molded product by using an adhesive. It was an increase in cost.

  Further, in the method of manufacturing an SMC molded product having a fixed convex metal fitting, a nesting of a shape corresponding to the convex part shape is put inside the convex part of the convex metal fitting provided with through holes at both ends, It is loaded into a mold having a cavity shape corresponding to the convex metal fitting and having recesses at the outer peripheral positions of both ends of the through hole and the convex metal fitting, and an SMC is disposed thereon. A method of manufacturing an SMC molded product that is heated and pressurized is disclosed (for example, see Patent Document 1).

  SMC molded product is a thermosetting resin material reinforced with glass fiber, and has high reliability in terms of dimensional stability and rigidity. Therefore, it is used for large exterior parts of automobiles and has high strength requirements for mounting seats. A structure is often used in which a metal fitting that can be bolted is joined with an adhesive. Adhesives are mainly epoxy-based, but adhesives that require high strength and high reliability require a long curing time, requiring heating for 24 hours at room temperature and about 10 minutes even at 140 ° C. . For this reason, when attaching a metal fitting to an SMC molded product, an adhesive jig for heating and holding is required, which is a problem in terms of man-hour and cost.

JP 2002-137239 A

  The present invention provides a bonding method that eliminates the need for a bonding jig for bonding a metal fitting to an SMC molded product and can reduce the number of steps.

The present invention is as follows.
(1) A method of adhering an SMC molded product to a metal fitting, in which an adhesive is provided between the sheet molding compound molded product (SMC molded product) and the metal fitting, and the metal fitting is fixed to the SMC molded product and adhesively cured. The molded product includes a convex (protruding) portion or a concave (depressed) portion and a pin shape, and the metal fitting comes into contact with the convex (protruding) portion or the concave (depressing) portion. And one or more pairs of leaf spring-like convex (projection) shapes that fit with the pin shape, and the leaf spring shape with respect to the pin-shaped width to be fitted. A bonding method characterized in that an interval between opening portions having a convex shape is narrow.
(2) Further, the SMC molded product has a hook shape for inserting a metal fitting, and the metal fitting or the SMC molded product has a protrusion corresponding to the adhesive thickness. Bonding method.

  According to the present invention, it is possible to provide an adhesion method that eliminates the need for an adhesion jig when attaching a metal fitting to an SMC molded product and can reduce the number of steps.

It is the schematic diagram which showed the outline | summary of this invention, (a) is a center sectional view of the adhesive goods which consist of a metal fitting and a SMC molded product, (b) is a top view. It is the schematic diagram which showed the outline | summary of this invention, and is a perspective view of the adhesive goods which consist of a metal fitting and a SMC molded product. It is the schematic diagram which showed the outline | summary of this invention, (a) is a center sectional view of the adhesive goods which consist of a metal fitting and a SMC molded product, (b) is a top view. It is the schematic diagram which showed the outline | summary of this invention, and is a perspective view of the adhesive goods which consist of a metal fitting and a SMC molded product.

Hereinafter, embodiments of the present invention will be described in detail.
The SMC molded product used in the present invention has a convex (protruding) portion or a concave (depressed) portion, and the metal fitting has a hole or convex (protruding) portion that contacts the convex (protruding) portion or the concave (depressing) portion. The position is determined with respect to the SMC molded product. Further, in contrast to the pin shape provided in the SMC molded product, the metal fitting is provided with one or more opening portions having one or more pairs of leaf spring-like protrusions that fit into the pin shape.
In addition, in the metal fitting, it is preferable in terms of stability that the opening portion having the leaf spring-like projecting shape is further two or more. Note that the number of the opening portions having the leaf spring-like protrusions is usually 5 or less. Moreover, in a metal fitting, the hole or convex (protrusion) part which contact | abuts to the convex (protrusion) part or concave (dent) part of a SMC molded product is 1-5 places normally. Moreover, the diameter of the hole or convex (projection) part which contact | abuts is 0.1-5 mm normally. Moreover, the thickness of a metal fitting is 0.5-10 mm normally.

By adopting this structure, an adhesive is applied between the SMC molded product and the metal fitting, and then the metal fitting is assembled to the SMC molded product, so that the metal fitting is positioned and held at a predetermined position and is stable. Adhesion becomes possible. The gap between the opening portions with a leaf spring-like convex (projection) shape relative to the pin-shaped width is narrow, so when the metal fitting is pushed into the pin shape, the periphery of the convex (projection) -shaped opening portion Since the part and the tip bite into the side surface of the pin, after being pushed in, even if there is a reaction force from below, it will not be pushed back or lifted. For example, the width of the pin shape is 0.5 to 5 mm, while the interval between the leaf spring-shaped convex (projection) shapes is narrower than that, and is 0.45 to 4.5 mm. Therefore, it is preferable that the space | interval of a leaf | plate spring-like convex (protrusion) shape is 0.05-0.5 mm narrow with respect to the pin-shaped width | variety.
Here, the pin shape is not limited to the cylindrical shape, and any pin portion having a pair of leaf spring-like convex (protruding) shapes may be used as long as it bites and fits, for example, a rectangular parallelepiped, a polygonal solid, a plate It may be in shape. The adhesive thickness can be controlled by providing a protrusion for regulating the thickness on the metal fitting side or the molded product side as has been conventionally done. About adhesive thickness, it is 0.1-10 mm normally.
For example, the adhesive may be cured by being left at room temperature (25 ° C.) in a state where the adhesive is pressed and held. Furthermore, when there is a coating in the subsequent process, it is possible to cure in a shorter time with heat due to the baking temperature of the coating. Although it depends on the paint specifications, for example, if the curing temperature after painting is 120 ° C., the adhesive curing is usually completed when the coating curing for about 20 minutes is completed.

  Although it does not specifically limit as an adhesive agent used by this invention, For example, an epoxy-type adhesive agent, an acrylic adhesive agent, a urethane type adhesive agent is mentioned, A thermosetting adhesive agent is especially preferable, and normal temperature (25 degreeC) A type that cures with is more preferable. The material of the metal fitting used in the present invention is not particularly limited, and examples thereof include iron, iron alloy, aluminum, aluminum alloy, and copper.

It is preferable that the SMC molded product used in the present invention is provided with a protrusion for controlling the adhesive thickness and a hook shape for inserting a metal fitting in addition to the positioning shape as described above. Further, a protrusion for controlling the adhesive thickness, that is, a protrusion corresponding to the adhesive thickness may be provided on the metal fitting. The height of the protrusion corresponding to the adhesive thickness is preferably 0.1 to 10 mm. In contrast to the pin shape provided in the SMC molded product, the metal fitting is provided with at least one opening portion having a leaf spring-like convex shape that fits with the pin shape. By adopting this structure, after providing an adhesive between the SMC molded product and the metal fitting, etc., the metal fitting is inserted into the hook shape of the SMC molded product and then pushed in and assembled to fit into the pin shape. The metal fitting is positioned and held at a predetermined position, and stable adhesion becomes possible. In addition, the said hook shape has a clearance gap of 0.5-5 mm normally.
The hook shape is not particularly limited, but may be any of a circle, a square, a triangle, and a polygon. In addition, it is preferable in terms of stability that the hook shape of the SMC molded product is two or more for one metal fitting.
The hook shape prevents the metal fitting from being lifted by the reaction force of the adhesive, and the protrusion secures the adhesive thickness. The thickness can be secured by providing the metal fitting or the SMC molded product with a protrusion corresponding to the adhesive thickness. For example, when the adhesive thickness is 1 mm, the height of the protrusion is 1 mm and is provided at one or more locations. However, it is preferable to provide three or more locations to ensure the adhesive thickness. By providing the protrusions, the contact area with the adhesive increases, so that the adhesive force is improved. Protrusions can be provided in several places to secure the adhesive thickness and many other protrusions that are lower than the adhesive thickness. In this case, the amount of adhesive used can be reduced and the contact area can be increased. The adhesive strength can be increased. For example, when the adhesive thickness is 1 mm, the height of the protrusion is 1 mm, and when the thickness of the metal fitting is 1 mm, the adhesive thickness can be controlled by setting the hook-shaped gap in the perpendicular direction to 2 mm. Therefore, it is preferable. When assembled into a hook shape, it can be easily inserted if one end of the metal fitting is approached obliquely from above. When there is no hook shape, the structure that fits with the pin shape preferably has two or more combinations that fit with the pin shape, but in this case it may be one location.

EXAMPLES Hereinafter, although the suitable Example of this invention is described, this invention is not limited to these Examples. Embodiments of the present invention will be described with reference to the drawings.
Example 1
As shown in FIGS. 1 and 2, the SMC molded product 1 is a thermosetting resin material reinforced with glass fiber, has a convex portion 2, and has a thickness of 1.0 mm. 4 is provided with a hole 5 in contact with the convex (protruding) portion 2, so that it is positioned with respect to the SMC molded product 1 during bonding. Here, although it is the shape of the convex (projection) portion 2 of the SMC molded product 1, a concave (dent) shape is not a problem as long as it can be positioned and positioned in contact with the metal fitting 4.
On the other hand, the SMC molded product 1 is provided with a pin shape 3, and the metal fitting 4 is provided with one or more opening portions 6 having one or more pairs of leaf spring-like protrusions to be fitted with the pin shape 3.
The opening size of the main opening 6 is minus tolerance (−0.2 mm) because the metal fitting 4 is held and bonded to the width of the pin shape 3 of the SMC molded product 1 when it is pushed into the SMC molded product 1. ). There were two opening portions having a leaf spring-like protrusion shape of the metal fitting, the opening size of the opening portion was 1 mm, and the pin-shaped width of the SMC molded product was 1.2 mm.
When bonding the metal fitting 4 to the SMC molded product 1, the bonding surface 7 of the SMC molded product 1 was sanded as a pretreatment, and the bonding surface 7 and the bonding surface 8 of the metal fitting 4 were degreased. Thereafter, an adhesive 11 is applied to the bonding surface 8 of the metal fitting 4, and a contact hole 5 having a diameter of 1 mm of the metal fitting 4 is fitted and positioned on the convex (projection) portion 2 of the SMC molded article 1. An opening portion 6 having a leaf spring-like protruding shape of the metal fitting 4 was pushed into and fitted into the pin shape 3 to hold and adhere the metal fitting 4.
The adhesive 11 to be used is a thermosetting epoxy adhesive, so the metal fitting 4 may be pushed into the SMC molded product 1 and held at room temperature (25 ° C.). In this case, curing can be completed at the baking temperature and curing time. Therefore, coating curing (heating) at 120 ° C. for 30 minutes was performed to complete the curing, and a desired adhesive product was obtained.

(Example 2)
As shown in FIGS. 3 and 4, the SMC molded product 1 includes a hook shape 9 having a gap of 1.5 mm and an adhesive thickness adjustment in addition to the metal fitting positioning shape similar to the first embodiment. A protrusion 10 having a height of 0.5 mm was provided, and a metal fitting 4 having a thickness of 1.0 mm was used. The target adhesive thickness was 0.5 mm. The relationship between the pin shape 3 and the opening portion 6 is the same as that of the first embodiment, but is only one.
Pretreatment is performed in the same manner as in Example 1, and the same adhesive 11 as in Example 1 is applied to the adhesive surface 8 of the metal fitting 4, and one end of the metal fitting 4 is placed in the gap of the hook shape 9 of the SMC molded product 1. Inserting and fitting the convex (protrusion) portion 2 of the SMC molded product 1 and the hole 5 in which the metal fitting 4 abuts, secures the thickness of the adhesive 11 with the projection 10 for adjusting the adhesive thickness, and positions the SMC molded product. An opening portion 6 having a leaf spring-like protruding shape of the metal fitting 4 was pushed into and fitted into the pin shape 3 of 1 to hold and adhere the metal fitting 4.
As a result of leaving it to stand at room temperature (25 ° C.) and confirming after 24 hours, curing was completed and predetermined adhesion was achieved.

  By using the method for bonding a metal fitting to an SMC molded product according to the present invention, the bonding process can be shortened and a bonding jig for heating and holding can be eliminated. As a result, preparation man-hours and periods for manufacturing can be shortened. This means cost reduction in terms of development man-hours, capital investment and processing. Further, the method for bonding a metal fitting according to the present invention can be applied to all structural products in which the metal fitting is bonded to the back surface of an SMC molded product.

1 SMC molded product, 2 SMC molded product protrusion or depression, 3 SMC molded product pin shape, 4 metal fittings, 5 metal hole or projection, 6 leaf spring-like projection opening, 7 SMC molding Product adhesive surface, 8 metal fitting adhesive surface, 9 SMC molded product hook shape, 10 SMC molded product adhesive thickness adjustment protrusion, 11 adhesive.

Claims (2)

  An adhesive is provided between a sheet molding compound molded product (hereinafter referred to as an SMC molded product) and a metal fitting, and the metal fitting is fixed to the SMC molded product and adhesively cured. The SMC molded product includes a convex (protruding) portion or a concave (depressed) portion and a pin shape, and the metal fitting is a hole or convex (protruding) that contacts the convex (protruding) portion or the concave (depressing) portion. ) Portion and one or more pairs of leaf spring-like convex (projection) shapes that fit with the pin shape, and the leaf springs with respect to the width of the pin shape to be fitted. A bonding method characterized in that an interval between openings having a convex shape is narrow.   The bonding method according to claim 1, wherein the SMC molded product has a hook shape into which a metal fitting is inserted, and the metal fitting or the SMC molded product has a protrusion corresponding to the adhesive thickness.

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