JPH0820998A - Grating and manufacture thereof - Google Patents

Abstract

PURPOSE:To make it possible to cut down the manhour of welding or the like and hold a sophisticated grating shape for a long time by constituting a grating made of cast steel which contains a specified % or below of carbon on which a letter or a figure is viewed at a lattice part, on a road surface or a floor surface. CONSTITUTION:A grating is 350mm in outside length and 250mm in width and 18mm in thickness and has a lattice of 23 rows in the longitudinal direction and 6 rows in the lateral direction in outside dimension where a 3mm wide and 1mm deep recessed part, which is an outline of an arrow, is partially installed to the lattice of 3mm thick gratings, is manufactured with a precision casting mold which is in conformity with the shape of the grating where a JIS 304-based stainless steel is heated to 1000 deg.C and then poured into a molding form. The composition of the SUS 304 stainless steel used herein is specified as follows: CO, 0.5 S 10.4, Mn 0.8, N 18.6 Cr 18.5 the rest Fe in weight percentage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grid surface that penetrates a gutter of a road or a sidewalk, a step of a staircase, a drainage floor of a kitchen, or a floor serving as a ventilation port for dust removal. And a manufacturing method thereof.

[0002]

2. Description of the Prior Art Gratings used for lids of gutters on roads and sidewalks, drainage floors of kitchens, etc. are generally made by combing a plate material called a bearing bar in a frame at predetermined intervals. It is manufactured by crossing rod-shaped members called cross bars and welding them. Stainless steel is used in such a field where corrosion resistance is particularly required. When corrosion resistance is not so required, a ductile cast iron grating produced by a sand mold is used. It is desirable that the above-mentioned grating is light in terms of handling, and when it is installed on a road or the like, it must have a strength that can withstand the load of an automobile or the like. Furthermore, it is necessary to have a safe structure that prevents pedestrians from slipping or falling and falling.

[0003]

Among the above-mentioned gratings, the grating made by welding stainless steel not only requires a great number of welding steps but also has a drawback that it is difficult to obtain a complicated shape suitable for a landscape. . Further, in the case of grating as a groove cover of a road for general pedestrians, the width of the through holes formed by the lattice is preferably 15 mm or less, and if it exceeds this, there is a risk that the heels of high heels may get caught. If a grid portion having such a narrow width is manufactured by welding, the number of welding steps is further increased, which is not preferable.

On the other hand, the ductile grating has the advantage that various shapes can be selected by sand mold casting, but usually 2 to 3% of C and 2 is used in order to secure castability.
Since it contains ˜7% of Si and the balance is substantially Fe, it is inferior in corrosion resistance and it is difficult to maintain the grating of complicated shape without rusting. Also, if stainless steel is produced by sand casting, the stainless steel
However, since it usually contains 1% or less and contains 10% or more of Cr, castability is poor, and there is a problem that a grating having a lattice shape cannot be manufactured. Further, in order to reduce the weight of grating, it is required to reduce the thickness of the lattice portion to 5 mm or less, which makes it more and more difficult to manufacture the grating by casting.

In addition, the ordinary grating does not provide any information other than the information that the grating exists, only the lattice is visible on the surface. In view of the above-mentioned problems, an object of the present invention is to provide a method for obtaining a grating having a lattice part and a display part for displaying meaningful information from a steel having poor castability with C of 1% or less, and to manufacture by this method. It is to provide a new grating.

[0006]

In order to reduce the thickness of the grating portion required for the grating to be lighter, the present inventor poured molten metal into a heated precision casting mold to form the grating grating portion. It was found that it is good, and that by this method, it is possible to obtain a grating with steel having a castability of C1% or less and having poor castability. Furthermore, they have found that extremely precise characters or figures can be cast by applying the above-mentioned precision casting method.

That is, the present invention is a grating on a road surface or a floor surface, in which characters or figures are cast on a lattice portion, and is composed of a cast steel product containing 1% or less of C. It is the grating.

Further, according to the present invention, by casting a convex portion or a concave portion on the lattice portion, a character or a graphic can be displayed on the grating surface. In the present invention, it is effective to cast characters or figures for evacuation or guidance of people or vehicles. Further, in the present invention, it is also effective to cast characters or figures extended in the traveling direction of a person or a vehicle.

Further, in the manufacturing method of the present invention for obtaining the above-mentioned grating of the present invention, a molten metal of steel containing 1% or less of C is poured into a heated precision casting mold to form a grating lattice portion, In addition, it is a method for manufacturing a grating, which is characterized by casting characters or figures.

[0010]

One of the greatest features of the present invention is that a grating having a lattice portion of a cast-integrated product is obtained from steel having a castability of C1% or less and having poor castability. In order to cast a steel having C1% or less, the present inventor applied a method of forming a grating lattice portion by pouring the molten metal into a heated precision casting mold. By this method, it is possible to obtain a grating by casting even stainless steel having excellent corrosion resistance, and a grating having a complicated shape can be retained for many years.

In the present invention, a character or graphic can be cast as it is. However, by casting a convex or a concave in the grating portion forming the grating, the character or graphic can be cast when the grating surface is viewed. It may be recognizable. In this case, particularly large characters or figures can be easily expressed without changing the grating lattice shape, which is effective.

Further, if characters or figures for evacuation or guidance in case of fire or the like are cast and displayed on the grating of the floor surface or the like according to the present invention, safe actions can be taken accordingly. Will be things. Furthermore, if the characters or figures are painted with a luminous paint, it will be possible to take even safer actions even at night during an emergency or during a power outage. That is, by casting characters or figures on the surface of the grating, the grating itself becomes the grating for transmitting information, and the information suitable for the place of use can be cast on the grating.

On the road surface, when viewed from the traveling direction of a car or a person, when a character or a graphic is cast in the grating as it is, it is recognized that the character or the graphic shrinks in the traveling direction. Some of them are difficult to read, but if the characters and figures can be read by extending them in the direction of travel, the safe action described above will be in a more certain direction. In addition, the grating in a place where a landscape is required, such as in a housing complex or a park, can be made into a grid shape that matches the landscape around it, and letters and figures can be cast on it.

The application of the precision casting method in the manufacturing method of the present invention is suitable for obtaining a thin cast product from a steel having a poor castability of C1% or less. By this method, it is possible to obtain a grating having a lattice portion with a wall thickness of 5 mm or less, and it is possible to further reduce the weight. Also, when this precision casting method is applied, the grating part of the grating becomes a skin with minute irregularities accompanied by a thin oxide film peculiar to precision casting, and as a result, it is difficult for pedestrians and automobiles passing over the grating to be slippery. Can provide grating. The unevenness of the surface roughness of the desirable grating portion is Rmax 10 μm specified in JIS B0610.
That is all.

In the present invention, C is defined as 1% or less because the crystallization temperature becomes lower as the C content increases.
This is because the castability is improved and it becomes unnecessary to manufacture the grating by applying the precision casting method. In the manufacturing method of the present invention, it is specified that casting is performed in a heated precision casting mold. This is an indispensable technique for the grating having a thin and complicated shape by the precision casting method, and it is impossible to obtain the grating having the lattice portion by the casting mold which is not heated. As the heating condition, it is desirable to heat the precision casting mold to 800 ° C. or higher.

[0016]

【Example】

Example 1 Outer dimensions shown in FIG. 1 length 350 mm, width 2
It has a grid of 50 mm and a thickness of 18 mm, and has 23 rows in the length direction and 6 rows in the width direction. A part of a grating grid having a thickness of 3 mm has a width of 3 mm and a depth of 1 mm to be an outline of an arrow.
The grooved groove was manufactured by pouring JIS 304 stainless steel after heating it to 1000 ° C. using a precision casting mold corresponding to the grating shape in FIG. The composition of the SUS 304 stainless steel used was C0.05, Si0.4, Mn0.
8, Ni8.6, Cr18.5, and the balance Fe.

The surface of the grating surface of the obtained grating is
In addition to having a fine uneven surface texture with a surface roughness Rmax of 18 μm, the concave portion of the contour forming the arrow has a width of 2.1 mm and a depth of 1.1 mm as a cast product, and the radius of curvature of the corner from the grating surface to the concave portion. When R was 0.25 mm, the recess was clearly cast, and it was possible to obtain the grating in which the arrow can be easily recognized from the virtual line connecting the recesses.

(Embodiment 2) The outer dimensions and the grid similar to those of the grating of Embodiment 1 are provided, and a recess having a depth of 1 mm is provided in a part of the grating of the grating, and from an imaginary line connecting the recesses,
The grating shown in FIG. 2 in which the arrow can be recognized as a concave shape was manufactured in the same manner as in Example 1. The surface texture of the obtained grating has a surface roughness Rmax of 19 μm, the concave depth of the arrow portion is 1.0 mm, and the radius of curvature R of the corner portion from the grating surface to the concave portion is in the range of 0.25 to 0.3 mm. Inside, the corners were extremely small and precise to form the outline of the arrow.

(Embodiment 3) The outer dimensions are the same as those of the grating shown in Embodiment 1, part of the surface of the lattice part is connected in a plate shape, and characters and figures are expressed by unevenness in this part. The grating shown in 1 was manufactured in the same manner as in Example 1. In the obtained grating, characters and figures are displayed by forming recesses at a depth of 1 mm in the plate-shaped part for displaying characters and figures. The radius of curvature R of the corner portion from the surface showing the outline of the character portion and the graphic portion to the concave portion is 0.3 mm
With that, I was able to obtain a grating that allows me to check characters and figures at a glance.

The surface roughness of the character surface and the concave surface is Rmax2.
The thickness is 1 μm, and the fine irregularities have an anti-slip effect when a person walks, which is effective in terms of safety. In addition, when the luminous surface of the concave portions of the characters and figures in FIG. 3 was painted, it became possible to recognize the figures and characters at night, which was effective for evacuation and guidance in an emergency.

(Embodiment 4) As shown in FIG. 4, small holes of φ5 mm are cast in the recesses connected to each other in the plate shape of the grating shown in FIG. 1mm difference between the low and
A grating was devised in the same manner as in Example 3 such that water was collected toward the small holes. According to the present invention, all the holes can be cast without blocking the small holes, and it is possible to obtain the grating that allows early drainage.

(Embodiment 5) The grating shown in FIG. 5 is manufactured in the same manner as in Embodiment 1 in a shape in which the grating portion forming the grating is left as it is and the numbers are convex. At this time, the display of the numbers is made vertically long at a ratio of 3 in the traveling direction with the width of the number being 1 with respect to the traveling direction of the vehicle or the person. The thickness of the number part is 3 mm, which is the same as the lattice part, and only the number part is 1 mm from the whole lattice surface.
The convex shape makes it easier to understand the numbers, and at the same time, the outer 1 mm convex outer corner of the number may damage the tires of cars, etc. if the corners are rounded, or trip over when people walk. It is rounded with a radius of curvature R 0.8 mm so as not to do so. If you cast a normal number as it is, it will be difficult to read because it will be recognized as a contracted number from the traveling direction, but the obtained grating is a number arranged vertically in the traveling direction. It became easy to read and was able to provide effective information. Further, the roughness of the surface of the numeral was Rmax of 20 μm, so that fine irregularities were obtained, and it became less slippery and was preferable in terms of safety.

Example 6 The same procedure as in Example 1 was carried out except that the molten metal was poured into a precision casting mold in which patterns were arranged on the entire grating having the irregularly shaped lattice shown in FIG. It was possible to clearly cast jagged edges and veins with delicate contours that show the leaf pattern of a figure. The thickness of the entire leaf of the figure is 2.5 mm, which is flush with the grating surface. The contour of the leaf has a radius of curvature R
The height of the protrusions corresponding to the contour of the jagged edges forming the leaves of the figure and the veins of the leaves of the figure is 0.4 to 0.4 mm.
It was in the range of 0.5 mm, and there was no problem in the risk of human walking. As described above, according to the present invention, a character design or a graphic motif is used, and various combinations such as a wavy shape or a ring shape can be used for the lattice shape in accordance with the surrounding landscape using grating.

[0024]

EFFECTS OF THE INVENTION According to the present invention, since a novel grating made of steel having C1% or less, which has conventionally been problematic in castability, can be provided as a cast product, the number of man-hours required for conventional welding can be reduced and the stainless steel can be reduced. It can also be applied to steel, allowing complex grid shapes to be retained for many years.
In addition, since the letters and figures are cast, it is possible to provide grating suitable for the landscape outdoors, and it is possible to evacuate and guide people in an emergency on floors indoors and outdoors. It is particularly effective in terms of safety. Also,
By applying the precision casting method, the thickness of the lattice part can be reduced to 5 mm or less, and the grating can be made lighter. For example, the grating removing operation performed for cleaning road grooves or the like. It is also extremely effective for the purpose of reducing. In addition, since the surface of the grating obtained by the precision casting manufacturing method has fine irregularities, it is possible to provide a grating that is difficult for pedestrians and automobiles to pass when it is used as a road grating, which is preferable for traffic safety. Become.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a grating produced by casting a figure of the present invention.

FIG. 2 is a diagram showing another example of grating representing a graphic according to the present invention.

FIG. 3 is a diagram showing an example of a grating formed by casting characters and figures according to the present invention.

FIG. 4 is a diagram showing another example of the grating in which the characters and figures of the present invention are cast.

FIG. 5 is a diagram showing an example of a grating formed by casting characters extended in the traveling direction of a person or a vehicle according to the present invention.

FIG. 6 is a diagram showing an example of a grating formed by casting a figure of the present invention.

Claims (5)

[Claims] 1. A grating for a road surface or a floor surface, in which characters or figures are cast in a lattice portion, and C is 1
%, Which is composed of a steel casting containing less than or equal to%. 2. The grating according to claim 1, wherein characters or figures are displayed on the grating surface by casting convex or concave portions on the lattice portion. 3. The grating according to claim 1 or 2, wherein characters or figures for evacuating or guiding a person or a vehicle are cast. 4. A character or graphic extended in the traveling direction of a person or a vehicle is cast.
4. The grating according to any one of items 1 to 3. 5. A method for producing a grating, which comprises pouring a molten steel containing 1% or less of C into a heated precision casting mold to form a grating lattice portion and casting a character or a figure. Method.