JP3457452B2 - Manufacturing method of grating - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skeletal member and a through hole used for a drain lid, a sash lid, a decorative lid, a sidewalk, an entrance mat, a tree go round, and the like. More particularly, the present invention relates to a method for producing grating with a skeletal portion reinforced. 2. Description of the Related Art Conventionally, gratings used for drainage gutters or the like are formed by crossing a cross bar, which is a longitudinal skeletal member constituting a grating, and a bearing bar, which is a skeletal member in a width direction, into a girder shape. It has a combined structure. As a manufacturing method of the grating, there are a method of drilling holes one by one in a metal flat plate, and a method of combining the flat plates with a cross beam to make the grating. However, the manufacturing requires a lot of labor. [0003] When manufacturing grating made of FRP for the purpose of weight reduction, a non-molding method such as a so-called hand lay-up method or a spray-up method is also employed. In addition, there is a problem that strict environmental management needs to be performed in order to use a large amount of organic solvent. Furthermore, a filament diameter of 10
~ 13μm, Tex per strand is 40 ~ 15
A glass fiber cut product obtained by cutting a glass fiber of 0 Tex to a length of 12 to 50 mm (hereinafter referred to as “chopped land” CS) is dispersed and contained at a content of 15 to 55% by weight with respect to the entire compound. There is also a method in which a sheet molding compound (hereinafter referred to as "SMC") is supplied into a lower half mold having a predetermined shape, and compression molded under heating to produce FRP grating. However, in such an FRP grating formed integrally by a compression molding method using only the SMC, a bearing bar, which is a longitudinal skeleton member constituting the grating, and a skeleton member in the width direction. When a load such as a person or a vehicle is applied to the crossbar, especially the bearing bar that is in a state of being bridged at both ends of the drain,
The bearing bar may be greatly warped in the load direction and the entire grating may be dented, or the bearing bar may be broken by a strong impact or the like. The reason for this is that the glass fiber contained in the SMC of the molding material is a short glass fiber cut to 12 to 50 mm, so that the reinforcing function as a composite material does not work sufficiently. . If the thickness of each bar is made sufficiently large to prevent this, dents and the like can be reduced to some extent, but the compression molding time will be lengthened by the increased thickness, and no additional material such as SMC will be used. However, there is a problem that the cost increases. [0005] Therefore, the present invention is to reduce the strength of the bearing bar and / or the crossbar constituting the grating in the case of manufacturing the grating by using the hot compression molding method having a fast molding cycle. It is an object of the present invention to provide a method of manufacturing a grating at a low cost without sufficiently lengthening the compression molding time while maintaining it sufficiently. [0006] In order to achieve the above-mentioned object, the present invention provides a sheet molding compound comprising a thermosetting resin composition and glass fiber as a reinforcing material. In a method for producing a grating, which is supplied into a mold having a compression molding under heating, is composed of a skeleton member and a through hole, and continuous glass fibers are disposed as a reinforcing material over the entire length of the skeleton member, The mold comprises an upper mold and a lower mold having at least two opposing side surfaces opened, and at least a part of an upper mold inner surface and a lower mold open surface constituting a cavity for molding an outer skeleton member of grating. A mold having a sliding portion that slides tightly with each other.
16 μm, Tex per strand is 500-60
00Tex continuous glass fiber (roving) alone or the continuous glass fiber
A step of projecting and placing the sheet molding compound contained in a fixed direction at a content of 5 to 55% by weight at the opening of the lower mold, a filament diameter of 10 to 13 μm, and a Tex per strand of 40 to 150 Tex. Placing a sheet molding compound containing a glass fiber cut product obtained by cutting the glass fiber into a length of 12 to 50 mm at a content of 15 to 55% by weight with respect to the entire compound on the upper surface of the lower mold; Lowering the upper mold and the lower mold while fitting the upper mold and the lower mold with the edges of the upper mold and the lower mold provided in the sliding portion, and cutting and cutting off the protruding reinforcing material; and And a step of subjecting the lower mold to clamping and compression molding under heating. [0007] In the present invention, the mold comprises an upper mold and a lower mold having two open sides facing each other, and the inner surface of the upper mold and the opening of the lower mold for forming the outer skeleton member of the grating. A continuous glass fiber (roving) alone or a sheet molding compound thereof is protruded and placed on the lower mold opening portion by using a mold having a sliding portion in which a part of the surface slides tightly with each other. . Next, the SMC containing CS is placed on the upper surface of the lower die, and the upper die and the lower die are fitted together while lowering the upper die. The protruding reinforcement is cut and cut off by the edge portion. Furthermore, when the upper mold and the lower mold are clamped and compression-molded under heating, a grating in which the skeleton member is sufficiently reinforced with continuous glass fibers can be produced. In the grating manufactured by the method of the present invention, since the continuous glass fiber is provided as a reinforcing material over the entire length of the skeletal member, the strength of the bearing bar, which is one of the skeletal members, is improved, Do not deform or bend easily. Further, the continuous glass fiber as the reinforcing material can be used alone or used as an SMC, and the skeleton member is made of FRP to reduce the weight. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The form of grating produced by the method of the present invention is shown in FIGS. FIG. 1 is a perspective view showing an example of draining-gutter lid grating, in which a through-hole 3 is provided surrounded by a skeletal member 2 constituting the grating 1, and the through-hole 3 is a rectangle having a length of 30 mm and a width of 12 mm. It is. In the grating 1, an outer skeleton member 2 serving as a frame fits into a drain groove (not shown) and serves as a drain groove lid. FIG. 2 is a view showing a cutaway portion taken along the line AA in FIG. As shown in the cross section in the width W direction, the skeletal member 2 is configured by a combination of a skeletal member 2A made of only SMC using CS as a reinforcing material or a skeleton member 2B made of SMC using roving as a reinforcing material. FIG. 3 is a partial perspective view showing an upper mold of a mold used in the manufacturing method of the present invention, and FIG. 4 is a partial perspective view showing an example of a lower mold. In FIG. 3, the upper die 5 is the outer skeleton member 2 of the grating 1.
Is mainly composed of a vertical wall 5F and a plane 5B. In FIG. 4, the lower mold 6 mainly includes a core 6B forming the through hole 3 and a cavity 6F forming the skeleton member 2. When the upper mold 5 is attached to a vertical device (not shown) and descends, The parting lines 5B and 6B, 5C and 6C, and 5D and 6D of the mold and the lower mold are joined to form the cavity of the grating 1.
When the upper die is fitted into the lower die by the lowering of the upper die, the sliding portion 5A of the upright wall portion 5F is preliminarily worked so as to slide tightly with the sliding portion 6A of the lower die. , Edge part 5
E and 6E are provided, and when a molding material such as SMC is extraly disposed outside the lower mold, the edge portions 5E and 6E are connected to each other when the upper mold and the lower mold are fitted. Excessive molding compound can be cut out and cut off. Next, a method for manufacturing grating according to the present invention will be described. Continuous glass fiber (roving) alone or continuous glass fiber (roving) as a reinforcing material is formed in a certain direction so as to form the skeleton member 2B at any one or more locations of the cavity 6F of the lower mold 6 shown in FIG. The SMC contained therein, that is, the SMC using roving as a reinforcing material, is preliminarily formed into a strip-shaped skeleton member 2B1, and this skeleton member 2B
The terminal part of 1 extends out of the lower mold and the terminal part 2B2 of the reinforcing agent
Is disposed in the cavity 6F. In this case, the continuous glass fiber (roving) has a filament diameter of 6 to 16 μm and a Tex per strand.
Is 500 to 6000, preferably 4000 to 4700T
ex of the continuous glass fiber (roving) is 15 to 55, preferably 20 to 35% by weight based on the whole sheet molding compound. Next, in order to form a skeletal member 2A composed of only SMC using CS as a reinforcing material, C corresponding to 60 to 90% of the projected area of the lower die,
An SMC containing S as a reinforcing material is placed on a core 6B provided in a lower mold. Next, FIG. 5 shows the form of the upper die 5 and the lower die 6 and the above-mentioned SMC which is a molding material during the forming of the grating. When the upper mold 5 starts descending, the edge portion 5E comes into contact with the terminal portion 2B2 of the skeleton member disposed in the cavity 6E immediately before the sliding portions 5A and 6A are fitted.
Further, with the lowering of the upper die, the cutting is started while the terminal portion 2B2 is sandwiched between the edge portions 5E and 6E, and the edge portion 5B is cut.
When E passes through the edge portion 6E, the terminal portion 2B2 is cut off from the skeletal member 2B and removed out of the mold, while the skeletal member 2 can contain sufficient continuous glass fibers to both outsides. When the terminal portion 2B2 is cut off, FIG.
As shown in FIG. 5, a cutout 4 which is a cross section of the cut continuous glass fiber remains on the grating product surface as a trace. By further lowering the upper die 5 in this manner, the upper die 5 and the lower die 6 are respectively brought into contact with the sliding surfaces 5A and 6A.
The SMC placed on the core portion 6B and having CS as a reinforcing material is compressed by the upper die flat portion 5B and the core portion 6B and extended to form the skeletal member 2 while sliding relative to A. Filling the cavity 6F. After the lowering of the upper mold 5 is completed, it is heated and compressed under the conditions of a temperature of 140 ° C., a pressure of 50 kgf / cm 2, and a holding time of 5 minutes, and then the upper mold 5 is raised to release the molded product, whereby grating 1 is obtained. . The grating 1 produced by the method of the present invention can be used for drainage ditch lids, sash lids, decorative lids, sidewalks, entrance mats, tree go rounds and the like. The through-hole 3 and the grating 1 are not limited to a square, but may be set to any shape such as a rhombus, a circle, and a heart, and the number thereof may be set arbitrarily. Also, the height of the anti-slip projection can be arbitrarily set as required. As described above, according to the method of manufacturing a grating according to the present invention, a skeletal member provided in at least one direction constituting the grating is provided with a reinforcing material as a reinforcing material.
Since the continuous glass fiber (roving) alone or the SMC containing the continuous glass fiber (roving) in a certain direction is provided, it is possible to obtain a grating sufficiently reinforced with the continuous glass fiber (roving) over the entire length of the skeletal member. it can. In the case of manufacturing the grating, the mold comprises an upper mold and a lower mold having two opposing side surfaces opened, and one of the upper mold inner surface and the lower mold open surface for molding the outer frame member of the grating. A continuous glass fiber (roving), which is a reinforcing material, or a sheet molding compound thereof is protruded from an opening of the lower mold and placed on a lower mold using a mold having a sliding part in which the parts slide tightly with each other. I do. Next, CS
Is placed on the upper surface of the lower mold, and the upper mold and the lower mold are fitted together while lowering the upper mold, and these edges of the upper mold and the lower mold provided in the sliding portion, The protruding end portion of the reinforcing material is cut and cut off. Furthermore, when the upper mold and the lower mold are clamped and compression-molded under heating, a grating in which the skeleton member is sufficiently reinforced with continuous glass fibers can be produced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a grating manufactured by the method of the present invention. FIG. 2 is a partially cutaway perspective view of the grating manufactured by the method of the present invention. FIG. 3 is a partial perspective view showing an example of an upper mold of a mold used in the manufacturing method of the present invention. FIG. 4 is a partial perspective view showing an example of a lower mold of a mold used in the manufacturing method of the present invention. FIG. 5 is a partial perspective view showing an example during molding of a mold used in the manufacturing method of the present invention. [Description of Signs] 1 Grating 2, 2A, 2B, 2B1 Frame member 2B2 Terminal part 3 Through hole 4 Cutout part 5 Upper die 6 Lower die 5A, 6A Sliding part 5B Flat part 5C, 5D, 6C, 6D Parting line 5E, 6E Edge 5F Standing wall 6B Core 6F Cavity L Grating length W Grating width

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI E03F 5/06 E03F 5/06 Z // B29K 101: 10 B29K 101: 10 105: 08 105: 08 B29L 31:00 B29L 31: 00 (58) Field surveyed (Int. Cl. ⁷ , DB name) E04C 2/00-2/54

Claims (1)

(57) [Claims 1] A sheet molding compound obtained by blending glass fiber as a reinforcing material with a thermosetting resin composition is supplied into a mold having a predetermined shape, and heated under heating. A method for producing a grating comprising compression-molding a skeletal member and a through-hole, wherein continuous glass fibers are disposed as a reinforcing material over the entire length of the skeletal member, wherein the mold is an upper mold and at least faces each other. A sliding portion, which comprises a lower mold having two open sides and at least a part of an inner surface of the upper mold and a lower mold opening surface which form a cavity for forming the outer skeleton member of the grating slide tightly with each other; A continuous glass fiber (roving) having a filament diameter of 6 to 16 μm and a Tex per strand of 500 to 6000 Tex as a reinforcing material. A step of projecting and placing a sheet molding compound containing the continuous glass fiber in a fixed direction at a content of 15 to 55% by weight with respect to the entire compound to the lower mold opening, and a filament diameter of 10 to 50%. 13 µm, glass fiber of Tex 40-150 Tex per strand 12-
A step of placing a sheet molding compound containing a glass fiber cut product cut to 50 mm at a content of 15 to 55% by weight with respect to the whole compound on the lower mold upper surface, and lowering the upper mold while lowering the upper mold. When mating with the mold,
By the upper and lower edge portions provided on the sliding portion,
A step of cutting and cutting the protruding reinforcing material, and a step of clamping the upper mold and the lower mold and compression molding under heating,
A method for producing grating, comprising: