JPH0414856B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a plate molded product, which involves forming a synthetic resin frame on the outer periphery of a plate-like member made of inorganic glass by injection molding. be.

BACKGROUND ART In general, examples of vehicle accessories as this type of plate molded product include front windows, sunroofs, quarter windows, and back windows.

Conventionally, in manufacturing these plate molded products, after molding a plate-like member having a desired outer shape from inorganic glass, it is placed inside the core mold or cavity mold of an injection molding mold. The frame portion is integrally molded around the periphery of the plate-like member by injecting synthetic resin that has been heated and melted in advance into the cavity space of the mold.

Problems to be Solved by the Invention However, with this manufacturing method, problems such as breakage are unlikely to occur if the plate-like member is flat, but if it is curved to a predetermined curvature, cracks will occur. The percentage will become high. In addition, when the frame is removed from the mold after molding, the frame shrinks due to natural cooling, and this contraction generates excessive internal stress in the frame, which may cause cracks in the frame over time. There is also a drawback that there is large variation in the sealability or adhesiveness between the frame and the glass surface.

Means for Solving the Problems In the method for manufacturing a plate molded product having a frame according to the present invention, from the peripheral side to the peripheral edge of a plate-shaped member formed with a predetermined curvature and a predetermined outer shape using inorganic glass. After applying adhesive to the board surface and heating the plate-shaped member to such an extent that the applied adhesive semi-cures and the entire surface of the plate-shaped member softens and thermally expands, the plate-shaped member is heated to this still high temperature and expanded state. A plate-shaped member is inserted into an injection mold and the mold is clamped, and molten resin is injected into the cavity space along the periphery of the plate-shaped member in the mold to integrate the frame with the periphery of the plate-shaped member. It is designed to be formed in a specific manner.

Function: In this method of manufacturing plate molded products, a plate-like member is heated from the peripheral side together with the adhesive attached to the plate surface near the periphery, and when the plate-like member is still in a high temperature and expanded state, the inside of the injection molding mold is heated. Therefore, even if the plate-like member is sandwiched between the molds when the mold is clamped, the plate-like member will not crack due to bending and deformation, and the frame will not shrink after the mold is removed. Since both the plate-like member and the plate-like member contract, internal stress is not generated in the frame portion, and the frame portion can be tightly fixed and molded to the plate-like member using an activated adhesive.

Embodiments The following description will be made with reference to the accompanying drawings.

The illustrated embodiment exemplifies the case where a quarter window for a vehicle is manufactured as a plate molded product, and the plate-like member 1 has a predetermined curvature and a predetermined outer shape as shown in FIG. As shown in a, it is formed by attaching an opaque print layer 2 to the back surface near the periphery. This plate-like member 1 is shaped so as to have a predetermined curvature in the vertical direction, as shown in FIG. 2b.

First, the plate-like member 1 includes the third and fourth parts.
As shown in the figure, adhesive 3 is applied from the peripheral side to the front and back surfaces near the peripheral edge. A thermosetting acrylic adhesive is preferably used as the adhesive 3, and the coating width is preferably slightly narrower than the molding width of the frame portion, which will be described later.

After the adhesive 3 is left to dry at room temperature or in an undried state, the plate-shaped member 1 is inserted into a heating furnace 10 and heated as shown in FIG. This heating furnace 10 can be either a hot air type or a side radiation type, and it is preferable to uniformly heat the entire plate-shaped member 1 within the furnace. The heating temperature is set within a temperature range in which the adhesive 3 is semi-cured and does not deteriorate, and is actually preferably about 80 to 120°C from the viewpoint of thermal expansion, softening, workability, etc. of the plate-shaped member 1. With this heating, the adhesive 3 is semi-hardened, and the plate-like member 1 is somewhat softened and at the same time expands outward to some extent. While maintaining this state, the plate-like member 1 is inserted into an injection mold and the mold is clamped. Even if the plate-like member 1 is slightly deformed due to variations in curvature due to this mold clamping, the amount by which the plate-like member 1 is bent within the mold is smaller than that at room temperature, as shown in FIG. Since it is quite large, it absorbs deformation and does not break. As shown in FIG. 7, even when heated to 80°C, the amount of deflection displacement is considerably larger than that at room temperature, and can be further increased by heating to 100°C to 120°C. After this mold clamping, heated molten resin is injected into the cavity space along the periphery of the plate-shaped member inserted into the mold to form the frame portion 4 as shown in FIG. As the molten resin
PVC resin heated and melted at about 180°C is preferably used, and PP elastomer, ABS resin, etc. can also be used. The injection molded frame 4
Since the plate-shaped member 1 is also heated and does not absorb the heat of the molten resin, the adhesive 3 is heated to a higher temperature and can be sufficiently cured, so that it can be firmly fixed to the plate-shaped member 1. When the mold is opened and the plate molded product is taken out after molding the frame portion 4, the frame portion 4 contracts as it cools naturally, and at the same time, the plate-like member 1 also contracts as a whole, causing the frame portion 4 to shrink. The internal stress due to the difference in the amount of shrinkage is reduced. Therefore, the frame portion 4 can be integrally attached to the plate-like member 1 so as to exhibit a tight sealing property with a large adhesive force combined with the fixation by the adhesive 3. In order to further improve the adhesion or sealing properties, it is preferable to apply an appropriate primer to the plate-shaped member 1 before applying the adhesive 3.

Incidentally, a mold as shown in FIG. 9 can be used for the injection molding of the frame portion 4 described above. This mold consists of a core mold 20 and a cavity mold 21.
A space 22 in which the plate-like member 1 can be positioned and mounted, and a cavity space 23 in which the frame portion 4 is formed are formed between the opposing surfaces. The resin flow path for filling the cavity space 23 with synthetic resin is
A first runner 25a is formed continuously from the nozzle touch part 24 of the cavity mold 21 on the split mold surface.
A plurality of first sprues 25b are formed in the cavity mold 21 along the longitudinal direction of the runner 25a, and a plurality of first sprues are formed substantially parallel to each side of the plate-like member 1 on the opposing surfaces of the cavity mold 21 and the core mold 20. 2
Runner 25c, second runner 25 on core mold 20
and a plurality of second sprues 25d formed along the longitudinal direction of c. The second resin flow path
From sprue 25d, submarine gate 25
It is preferable to inject the synthetic resin from the back side of the frame portion 4 formed within the cavity space 23 via the hole e. In addition, with this mold, as shown in FIG. 10, the dam rubber part 4a that is adhesively fixed to the object to be attached can also be molded integrally with the frame part 4, and an excess sprue part 4b remains on the inner flange side. But,
Even if this is cut out afterwards, it is located on the back side of the frame portion 4, so the cut marks will not spoil the appearance. In the case where the object to be attached is fixed or temporarily fastened by bolting, the stud bolt 5 can be installed at the same time as the frame 4 is formed by embedding and fixing the head as shown in FIG. Furthermore, the present invention is applicable not only to the manufacture of various types of windows for vehicles as described above, but also to the manufacture of residential windows and the like.

Effects of the Invention As described above, according to the method of manufacturing a plate molded product having a frame portion according to the present invention, it is possible to prevent the plate-like member from cracking within the mold, and to form the frame portion with greater adhesive force or sealing performance. It can be molded in one piece.
This is particularly effective when glass containing internal stress due to heat treatment, such as tempered glass, is used as a plate-shaped member.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a plate-like member at a stage before applying the method according to the present invention, FIG. 2a is a partial cross-sectional view taken along the line A-A in FIG. 1, and FIG. -B
3 is a perspective view of a plate-like member coated with adhesive, FIG. 4 is a partial cross-sectional view taken along line C-C in FIG. 3, and FIG. 5 is a heat treatment process of the plate-like member. FIG. 6 is an explanatory diagram showing the state of deflection displacement of the heat-treated plate-like member, FIG. 7 is a graph showing the amount of displacement of the plate-like member corresponding to the heating temperature, and FIG. 8 is a graph showing the displacement of the plate-like member according to the present invention. FIG. 9 is a sectional view of an injection molding die applicable to the same method; FIG. 10 is a partial perspective view of the plate molded product shown in FIG. 8;
FIG. 1 is a partial sectional view showing a modification of the plate molded product. 1: Plate-shaped member, 3: Adhesive, 4: Frame,
10: Heating furnace, 20, 21: Injection mold, 23: Cavity space.

Claims (1)

[Scope of Claims] 1. An adhesive is applied from the circumferential side of a plate-like member formed in an inorganic glass to a predetermined outer shape with a predetermined curvature to the plate surface near the periphery, and the applied adhesive is half-filled. After heating the entire surface of the plate-like member to the extent that it hardens and softens and thermally expands, the plate-like member, which is still at high temperature and in an expanded state, is placed inside an injection mold and clamped. and a plate having a frame portion, characterized in that the frame portion is integrally formed with the periphery of the plate-like member by injecting molten resin into a cavity space along the periphery of the plate-like member within the mold. Method of manufacturing molded products. 2. The method of manufacturing a plate molded product according to claim 1, wherein the heating is performed at a temperature of about 80 to 120°C.