JP3568664B2 - Manufacturing method of grating - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a grating used for drainage ditch lids, scab lids, decorative lids, sidewalks, entrance mats, tree go lands, and the like, and a method for producing the same, and more particularly, to a method for producing grating subjected to a non-slip treatment. .
[0002]
[Prior art]
Heretofore, many gratings used for drainage ditch lids or the like do not take into account slipperiness during walking or the like. On the other hand, there is a method in which fine unevenness is provided on the surface of the grating to prevent slipping, but much labor is required to make the unevenness.
[0003]
As a method of manufacturing these gratings, there are a method of drilling holes one by one in a flat plate, a method of combining flat plates with a cross beam, and the like, and the manufacturing requires a great deal of labor. . Furthermore, when manufacturing grating made of FRP, a sheet molding compound (hereinafter, referred to as "SMC") or a bulk molding compound (hereinafter, referred to as "BMC") is supplied into a half mold having a predetermined shape as in the related art. However, in the method of compression molding under heating, there is a problem in the treatment of burrs 12 generated in the center of the through hole 3 as shown in FIG. 5, and each of the burrs between the frame members 4 constituting the grating has a problem. Non-molding methods such as a hand lay-up method and a spray-up method have been employed because the processing requires a great deal of labor.
[0004]
In other words, burrs due to molding are generated at the center of the through-hole which is the mating surface of the half mold, so that the burrs in the through-holes are vertically removed in each of the through-holes by a cutter for deburring. However, there is a problem that the number of man-hours required according to the number of through holes is required, and much labor is required.
[0005]
[Problems to be solved by the invention]
Therefore, the present invention provides a simple shape and effective anti-skid treatment, can remove all burrs at once in the hot compression molding of a rapid molding cycle, and can greatly improve productivity. An object of the present invention is to provide a method for manufacturing grating.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method for producing a grating comprising a skeleton member and a through-hole by supplying SMC or BMC into a mold having a predetermined shape, and compression-molding under heating. Burrs generated by compression molding are generated in a convex shape at the edge of the skeletal member, and then the burrs are removed from the outer surface of the skeletal member in a range of 0.1 mm or more and 7 mm or less to remove the convex portion. This is a method of manufacturing a grating that is formed. More specifically, the SMC or the BMC is cut by 15% or more and 55% or less of a glass fiber having a cut length of 1/16 inch or more and 1 inch or less. The unsaturated polyester resin composition contained.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
The grating obtained according to the present invention can be easily manufactured because only the convex portion surrounding the through hole is provided at the edge of the skeletal member constituting the grating, and can be easily walked in a slippery condition such as in rainy weather. Even when a person walks on the grating, the soles of the shoes are caught by the protruding portions, so that the soles are reliably prevented from slipping and do not fall.
[0008]
In the manufacturing method of the present invention, the grating is manufactured by hot compression molding with a high molding cycle, and the upper mold and the lower mold are divided not at the center of the mold but at the outside of the grating as a product. A cutter for deburring by generating burrs accompanying compression molding outwardly on the mating surface of the mold outside the skeleton member and leaving the burrs within a range of 0.1 mm to 7 mm from the outer surface of the skeleton member. If it moves, etc., it becomes possible to cut the burrs protruding from the outer surface of the skeletal member at once, leaving a convex part that will prevent slipping, and it is necessary to remove each burr of each through hole. As a result, productivity is greatly improved. In this case, it is preferable to project the inner angle between the inner surface of the convex burr and the outer surface of the through hole so as to be 5 degrees or more and 90 degrees or less.
[0009]
Further, by using, as SMC or BMC, an unsaturated polyester resin composition containing 15% or more and 55% or less of glass fibers having a cut length of 1/16 inch or more and 1 inch or less, each skeleton member of grating is provided. A lot of glass fiber penetrates into the inside, improving the strength and appearance. Here, if the cut length of the glass fiber is less than 1/16 inch, the reinforcing effect by the glass fiber cannot be obtained, and if it is longer than 1 inch, it becomes difficult for the glass fiber to enter each lattice, The strength and appearance of the panel decrease. On the other hand, if the glass fiber content is less than 15%, the reinforcing effect of the glass fiber cannot be obtained, and if it is more than 55%, the fluidity of the SMC or BMC becomes poor, and a predetermined shape of each lattice is obtained. It becomes difficult.
[0010]
【Example】
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing an example of grating for drainage ditch lid obtained by the manufacturing method of the present invention, and a projection 13 surrounding a through hole 3 is provided at an edge of a skeletal member 4 constituting the grating 1. Is provided. The width d1 of the skeletal member 4 is 7 mm, and the through hole 3 is a rectangle having a length of 30 mm and a width of 12 mm. The projection 13 has a height of 0.7 mm, a width of 1 mm, and a rising angle of 15 °. In the grating 1, the frame body 2 fits into a drain groove (not shown), and serves as a drain groove lid. FIG. 2 is a diagram showing a cutout portion of the AA portion in FIG.
[0011]
FIG. 3 is a perspective view showing a state before deburring of the grating obtained by the manufacturing method according to the present invention, and burrs 12 generated by compression molding are generated in a convex shape outside the frame member 4. I have. Thereafter, by moving a cutter (not shown) in the direction of the arrow, the intermediate molded product is removed at a time with the burr 12 remaining 0.7 mm from the outer surface 7 of the skeleton member 4. The remaining burrs 12 finally form the anti-skid projections 13, and the grating 1 of the present invention is obtained. The height of the antiskid projection 13 can be easily adjusted only by changing the deburring position.
[0012]
FIG. 4 is a partial cross-sectional view showing an example of a mold used in the manufacturing method of the present invention. The intermediate molded product in FIG. 3 contains 25% of glass fibers having a cut length of 1/8 inch. The SMC comprising the unsaturated polyester composition is supplied into the mold 5 and subjected to heat compression molding at a temperature of 140 ° C., a pressure of 50 kg / cm ² , and a holding time of 5 minutes. The mold includes an upper mold 5a and a lower mold 5b, and the upper and lower mold divided surfaces 6 coincide with the outer surface 7 of the skeleton member 4. The rising angle 8 of the lower mold 5b on the division surface 6 is 85 degrees, and the angle 9 up to the upper mold 5a is 90 degrees. With the heating and compression of the SMC, the SMC flows into the cavities 10 and 11 formed by the upper mold 5a and the lower mold 5b, and the skeleton member 4 is formed by the cavity 10 and the burr 12 is formed by the cavity 11. . A convex burr 12 as shown in FIG. 3 remains in the intermediate molded product taken out from the mold 5, and the inner angle between the inner surface of the burr 12 and the outer surface 7 of the skeleton member 4 is determined by the height of the lower mold 5 b. The raising angle is 8, that is, 85 degrees. In addition, if the width of the cavity 10 is reduced as it goes downward, it is easy to extract the cavity 10 from the mold.
[0013]
The grating 1 obtained by the production method of the present invention can be used for a drain cover, a sash cover, a makeup cover, a sidewalk, an entrance mat, a tree goland, and the like. The through-hole 3 and the grating 1 are not limited to a quadrangle, but may be any shapes such as a rhombus, a circle, and a heart, and the number thereof may be arbitrarily set. Also, the height of the anti-slip projection can be arbitrarily set as needed.
[0014]
【The invention's effect】
As described above, according to the grating manufacturing method of the present invention, it is possible to easily manufacture a structure in which a convex portion surrounding a through hole is provided at an edge portion of a skeletal member constituting the grating. Even if a pedestrian walks on the grating in a situation where it is easy to slip, the sole of the shoe is caught by the convex portion, so that the shoe is reliably prevented from slipping and does not fall.
[0015]
In addition, since the grating is supplied into a mold having a predetermined shape of SMC or BMC and is compression-molded integrally under heating, the molding cycle becomes faster, so that the upper mold and the lower mold are not at the center of the mold, Divide by the outside of the grating, which is the product, and generate burrs due to compression molding on the mating surface of the outer mold of the skeletal member in a convex shape, and the burrs are 0.1 mm to 7 mm from the outer surface of the skeletal member Since the burrs were removed while leaving the burrs, it was possible to cut the burrs protruding from the outer surface of the skeletal member at a time while leaving a convex portion serving as a non-slip, and deburring each of the through holes. Since there is no need, productivity is greatly improved. If an unsaturated polyester resin composition containing 15% or more and 55% or less of glass fibers having a cut length of 1/16 inch or more and 1 inch or less is used as the SMC or BMC, the inside of each skeleton member is reduced. Glass fiber penetrates a lot to improve strength and appearance.
[Brief description of the drawings]
FIG. 1 is a perspective view showing grating obtained by the present invention.
FIG. 2 is a perspective view in which the grating shown in FIG. 1 is partially cut away.
FIG. 3 is a perspective view showing a state before deburring a grating manufactured according to the present invention.
FIG. 4 is a partial cross-sectional view illustrating an example of a mold used in the manufacturing method of the present invention.
FIG. 5 is a perspective view showing a state in which burrs are generated by a conventional grating manufacturing method.
[Explanation of symbols]
1 {Grating 2} Frame 3} Through Hole 4} Skeleton Member 5> Die 5a> Upper Die 5b> Lower Die 6> Upper and Lower Mold Separation Surface 7> Skeleton Member Outer Surface 8> Die Division Surface The rising angle of the lower mold at 9 ° The angle to the upper mold at the split surface of the mold at 10, 11 ° Cavity 12 composed of the upper and lower molds {Burr 13} Projection

Claims (2)

In a method of supplying a sheet molding compound or a bulk molding compound into a mold having a predetermined shape, and compression-molding under heating to produce a grating composed of a skeleton member and a through hole, a burr generated along with the compression molding. Is generated in a convex shape at the edge of the skeletal member, and thereafter, the burrs are removed from the outer surface of the skeletal member in a range of 0.1 mm or more and 7 mm or less to form a convex portion. Grating manufacturing method. The sheet molding compound or the bulk molding compound is an unsaturated polyester resin composition containing 15% or more and 55% or less of glass fibers having a cut length of 1/16 inch or more and 1 inch or less. Manufacturing method of grating.

Images