KR100745095B1 - Manhole cover made of composite materials, mold and manufacturing method thereof - Google Patents

Abstract

A manhole cover is provided to reduce the whole weight by manufacturing with composite materials of a metal core and plastics, and to increase durability and to prevent the accident from electric shock by keeping a metal core concealed. The manhole cover(100) is manufactured with plastics and composed of a horizontal plate(100a) exposed to the outside and a stiffening rib(100b) formed on the lower side of the horizontal plate to reinforce and support the horizontal plate, wherein a metal core(110) is located in the stiffening rib to be manufactured with metal and plastics integrally and to enhance the stiffening resistance of the stiffening rib. The horizontal plate is composed of a primary plastic layer(120), a fiber mat(130) formed between a primary plastic layer and a secondary plastic layer to keep a primary plastic layer and a secondary plastic layer not to be mixed and to prevent interface delamination, and a secondary plastic layer(140) formed on the fiber mat and mixed with luminous or noctilucent materials to maximize luminous or noctilucent effect, and surface-treated with reinforcing fiber cloth(150) to prevent the abrasion caused by motor vehicle friction.

Description

Composite manhole cover, mold for its manufacture and composite manhole cover manufacturing method using the same {Manhole cover made of composite materials, mold and manufacturing method

1 is a view showing a conventional manhole cover.

2 is a view showing a mold used in the molding of a conventional plastic manhole cover.

3 is a view showing a composite manhole cover according to the present invention.

4 is a view showing a metal core applied to the composite manhole cover of FIG.

5 is a view showing a mold for molding the composite manhole cover of FIG.

6 is a flowchart illustrating a method of manufacturing a composite manhole cover using the mold of FIG. 5.

<Description of the symbols for the main parts of the drawings>

100: manhole cover 100a: horizontal plate

100b: reinforcement 110: metal core

120: first plastic layer 130: fiber mat

140: second plastic layer 150: reinforcing fiber cloth

210: lower frame 220: upper frame

230: ejector pin

The present invention relates to a manhole cover in which a metal core and plastic are combined, a mold for easily manufacturing the same, and a method of manufacturing a composite manhole cover using such a mold.

Manholes are installed below the floor of urban roads and sidewalks for maintenance of various urban infrastructure such as sewerage, waterworks, telecommunications, and power line facilities. And the upper manhole cover exposed to the ground.

The manhole cover is most commonly made of steel castings of carbon steel, and the manhole cover of such a material is very heavy, which makes installation and maintenance difficult. In addition, it is easy to recycle because it is made of a single material, and theft accidents are inconvenient, and as a result, unnecessary additional installation costs, as well as damage to vehicles and lives. In addition, it may act as a cause of electric shock in rainy weather. In order to solve the problem of the manhole cover, a manhole cover of plastic has been developed, but it has a disadvantage of weak strength. In addition, the manhole cover of a composite material composited with plastic and steel as shown in Figure 1 has been developed and has been filed as a patent application No. 2004-5093, but such a manhole cover has a structure in which the steel is exposed to the outside to avoid the electric shock problem You still have it.

On the other hand, Figure 2 is a view showing a mold used in the molding of the conventional plastic manhole cover, the conventional mold is configured in a form in which the lower frame is accommodated as the upper frame, the mold is a state in which the lower frame and the upper frame is aligned Used in That is, a plastic manhole cover is manufactured by filling the molten plastic in a state where the lower frame and the upper frame are aligned and then compressing the upper frame. Such a mold adopts a conventional plastic fabrication mold in which a molten plastic flows down the lower frame to induce a neat treatment of the upper part of the molded article, which is not preferable for manufacturing a complicated manhole cover. . Because it is difficult to check whether the molten plastic is properly filled, there was a difficulty in securing the quality, and because the bonding area between the upper mold and the molded product is large, it is not easy to demould.

SUMMARY OF THE INVENTION The present invention has been made to improve the above-described problems, and an object thereof is to provide a composite manhole cover which reduces the total weight by compounding a metal core and plastic.

It is another object of the present invention to provide a composite manhole cover that improves durability by preventing corrosion by preventing external exposure of the metal core and further suppresses the occurrence of electric shock accidents in rainy weather.

Still another object of the present invention is to provide a mold and a method of manufacturing a manhole cover using the same, which enables to manufacture a manhole cover formed of a metal core and plastic with excellent quality, as well as to easily demold the molded manhole cover. It is.

The present invention for achieving the above object is a manhole cover formed of plastic to include a horizontal plate; and a reinforcing bar formed on the lower surface of the horizontal plate, the metal and the plastic while placing the metal core inside the reinforcing bar It provides a composite manhole cover, characterized in that integrally manufactured.

In addition, the present invention is a mold for manufacturing a manhole cover comprising a horizontal plate; and a reinforcement bar formed on the lower surface of the horizontal plate,

A manhole cover groove is formed in the center of the upper surface to form a horizontal plate groove and a reinforcement rib-shaped reinforcement groove, and a through hole having a smaller size than the reinforcement groove so as to extend from the reinforcement groove to the bottom of the lower surface. A lower frame formed; An upper frame having a crimping portion projecting to fit into the horizontal plate groove of the lower frame; And an ejector pin inserted into the through-hole of the lower frame, and provides a mold for manufacturing the composite manhole cover.

In addition, the present invention in the manufacture of a composite manhole cover, (a) preparing a metal core having a thickness for the manufacture of a composite manhole cover and a thickness smaller than the width of the reinforcement groove of the mold lower frame and less than the through-hole ; (b) inserting and placing the metal core into the reinforcement groove of the mold lower frame; (c) filling the molten plastic into the reinforcing rib groove and the horizontal plate groove of the mold lower frame; (d) arranging the mold upper mold above the mold lower mold and pressing the molten plastic filled in the mold lower mold by the crimping portion of the mold upper mold; (e) removing the mold top frame; And, (f) pushing the ejector pin to demold the mold lower frame provides a composite manhole cover manufacturing method comprising a.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments.

3 is a view showing a composite manhole cover according to the present invention. As shown, the manhole cover 100 of the present invention is a manhole cover formed of plastic to include a horizontal plate (100a); and a reinforcement (100b) formed on the lower surface of the horizontal plate (100a), Positioning the metal core 110 inside the reinforcing bar (100b) is characterized in that the metal and plastic to be manufactured integrally. Plastic has the advantage that it can be produced with a clean surface finish while freeing its shape, but has a disadvantage in that it is inferior to steel in strength such as bending performance, in order to complement this material property in the present invention to provide a metal core (110) By integrating both plastic and metal materials, the advantages of quantum properties are maximized and the disadvantages are compensated for.

In the manhole cover 100 of the present invention, the horizontal plate 100a is a top plate whose upper surface is exposed to the outside, and the reinforcement bar 100b is a support for supporting the horizontal plate 100a. Such a configuration of the horizontal plate (100a) and reinforcement (100b) is a structure for maximizing the strength while reducing the thickness of the entire manhole cover (100). In particular, in the present invention, by placing the metal core 110 inside the reinforcement bar (100b) to further strengthen the reinforcement strength of the reinforcement bar (100b), the metal core 110 protrudes over the reinforcement bar (100b) If it extends to the inside of the flat plate 100a, the reinforcing effect by the metal core 110 will be increased.

In the manhole cover 100 of the present invention, the horizontal plate 100a includes a first plastic layer 120 on the reinforcement bar 100b; And, the fiber mat 130 on the first plastic layer 120; And a second plastic layer 140 formed by mixing a luminous body or a photoluminescent body on the fiber mat 130. The fibrous mat 130 provided between the first plastic layer 120 and the second plastic layer 140 may prevent the first plastic layer 120 and the second plastic layer 140 from being mixed and prevent interfacial peeling. In order to maximize the luminous or photoluminescent effect with a small amount of luminous material or luminous material by allowing the luminous material or the luminous material to be mixed only in the second plastic layer 140, the fiber mat 130 serves to reinforce the plastic. Sometimes. In particular, the horizontal plate (100a) can be a surface reinforcement treatment of the upper surface with the reinforcing fiber cloth 150, which is to suppress the wear caused by friction, such as vehicle progress. At this time, if you configure a variety of colors, designs of the surface-treated reinforcing fiber cloth 150 will be able to easily produce a manhole cover 100 is finished in a variety of designs.

FIG. 4 is a view illustrating a metal core 110 applied to the composite manhole cover of FIG. 3, and shows a metal core 110 having a grating structure of a lattice. The metal core 110 preferably uses cast steel. In particular, the metal core 110 may form a connection hole 111a or a connection groove 111b. The connection hole 111a or the connection groove 111b may increase integration of the metal core 110 and the plastic. It serves as a connection key.

5 is a view showing a mold for molding the composite manhole cover of FIG. The mold includes a lower mold 210, an upper mold 220 and an ejector pin 230, and has a structure in which the upper mold 220 is accommodated in the lower mold 210. It is different from the mold.

The lower frame 210 is a groove of the shape of a manhole cover 100 in the center of the upper surface is formed with a horizontal plate groove 210a and a reinforcement groove 210b in the shape of a reinforcement 100b as a horizontal plate 100a. The through-hole 211 having a smaller size than the reinforcement groove 210b is formed to extend from the reinforcement groove 210b to the bottom of the lower surface. When the molten plastic is filled and cured in the horizontal plate groove 210a and the reinforcement groove 210b of the lower frame, the manhole cover 100 of the plastic molding is completed. The lower frame 210 is preferably formed of an inclined reverse slope that becomes narrower as the horizontal plate groove (210a) and the reinforcement groove (210b) is lowered, which is a molded manhole cover 100 the lower frame This is for easily demolding at 210.

The upper frame 220 is configured to have a crimping portion 221 protruding to fit into the horizontal plate groove 210a of the lower frame. The upper frame 220 is completed in a structure in which the upper frame 220 is accommodated in the lower frame 210 by the configuration of the crimping unit 221, and as a result, the joining area of the upper frame 220 and the manhole cover 100 molded and manufactured can be minimized. It becomes easy to demould the upper frame 220.

Ejector pin 230 is a configuration that is inserted into the through-hole 211 of the lower frame, it is used to demold the molded manhole cover 100 completed in the lower frame (210). In other words, when the molten plastic is cured and the manhole cover 100 of the plastic molding is completed, the ejector pin 230 is lifted to lift the reinforcement bar 100b of the manhole cover, thereby lowering the manhole cover 100 from the lower frame 210. ) Will be demolded. In particular, the present invention proposes two types of the first pin 230a and the second pin 230b as the ejector pin 230. The first pin 230a is disposed only in the through hole 211 of the lower frame. To lift the bottom of the reinforcement bar 100b of the manhole cover, and the second pin 230b extends through the through hole 211 of the lower frame to the reinforcement bar groove 210b and the horizontal plate groove 210a. Is arranged to extend to serve to lift the bottom and side of the reinforcement (100b) of the manhole cover at the same time. At this time, the second pin (230b) reinforcement should be formed in the middle position of the reinforcing rib groove 210b while the first end 231 is formed in a position matching the bottom of the reinforcing rib groove 210b. The bottom 100b of the flesh 100b may be raised at the same time. However, since the second pin 230b extends to the horizontal plate groove 210a, a hole is naturally formed in the manhole cover horizontal plate 100a at the position where the second pin 230b is disposed. Is formed as a step by the second end 232 of the second pin (230b) to the reinforcement bar (100b) can be utilized as a locking hole (100c) for catching the latch when installing or removing the manhole cover (100) Will be.

FIG. 5 is a flowchart illustrating a method of manufacturing a composite manhole cover using the mold of FIG. 4, and a method of manufacturing the composite manhole cover will be described with reference to the drawing.

(a) Material preparation

A metal core 110 having a thickness having a thickness greater than the width of the through-hole 211 and smaller than the width of the reinforcement groove 210b of the mold and the mold lower frame is prepared.

The metal core 110 may be provided to be coated with plastic, which is advantageous for integrating the metal core 110 and plastic.

When a mold including an ejector pin 230 composed of a first pin 230a and a second pin 230b is adopted as a mold as shown in FIG. 4, when the metal core 110 is installed in the mold lower frame 210, The stepped grooves 112 are formed in the part of the ejector pin 230 that meets the second pin 230b.

(b) Metal core placement

The metal core 110 is inserted into the reinforcement groove 210b of the mold lower frame. The through hole 211 formed in the mold lower frame 210 is closed by the arrangement of the metal core 110.

However, in the case of the ejector pin 230 composed of the first pin 230a and the second pin 230b, the reinforcing groove 210b of the mold lower frame is preliminarily formed before the metal core 110 is disposed. ) To be inserted. Thus, the metal core 110 may be installed such that the stepped groove 112 of the metal core is caught by the second end 232 of the second pin. Of course, the first pin 230a may also be inserted into the through hole 211 of the mold lower frame in advance to support the metal core 110. When the first pin and the second pin are pre-installed in this way, the metal core 110 has its bottom contact 112 with its bottom contacting the first pin 230a and the first end 231 of the second pin. It may be inserted into the reinforcing rib groove 210b of the mold lower frame so as to span the second end 233 of the second pin.

(c) melt plastic filling

The molten plastic is filled in the reinforcing bar groove 210b and the horizontal plate groove 210a of the mold lower frame. Since the reinforcement rib groove 210b and the horizontal plate groove 210a are completely exposed, the molten plastic is filled, so that the filling operation can be carried out in a tight manner while directly checking with the naked eye, thereby making it possible to manufacture a manhole cover 100 of excellent quality. . At this time, it is advantageous to ensure the strength of the manhole cover 100 to adopt a reinforced plastic as the molten plastic.

In particular, the horizontal plate (100a) of the manhole cover the first plastic layer (120); Fiber mat 130; Second plastic layer 140; Reinforcing fiber cloth (150); when the laminated structure of the first step of filling the molten plastic according to the stacking order; Covering the fiber mat 130; Secondly filling the molten plastic; Step of laying the reinforcing fiber cloth 150; to be subdivided.

(d) Crimping mold upper frame 220

The mold upper mold 220 is placed on the mold lower mold 210 to compress the molten plastic filled in the mold lower mold 210 by the pressing part 221 of the mold upper mold. The compacted plastic tissue will be compacted and thus will be completed with a manhole cover 100 of increased strength.

(e) Removing the mold upper frame 220

When the compressed molten plastic is cured, the upper mold 220 is removed. Since the mold upper mold 220 is accommodated in the mold lower mold 210, the bonding area between the upper mold 220 and the plastic is minimized, and the removal of the upper mold 220 is easily performed.

(f) Mold Subframe 210

The ejector pin 230 is pushed to demold the mold lower mold 210. Since the eject pin 230 contacts only the metal core 110, the mold lower mold 210 may be demolded without damaging the plastic. This completes the manufacture of the plastic manhole cover 100 reinforced with the metal core 110.

In particular, when demolding using the eject pin including the second pin 230b, the locking hole may be naturally formed in the manhole cover horizontal plate 100a by the second pin 230b. Furthermore, the engaging hole 100c formed in the horizontal plate 100a is formed as a stepped portion while leading to the lower reinforcement bar 100b and the metal core stepped groove 112 contacting the second end of the second pin 230b is exposed. Since the clasp is caught by the stepped groove 112 of the exposed metal core through the catching hole 100c, the manhole cover 100 can be installed and dismantled while suppressing damage to the plastic. .

Although the present invention has been described in detail with reference to the described embodiments, those skilled in the art to which the present invention pertains will be capable of various substitutions, additions and modifications without departing from the technical spirit described above. It is to be understood that such modified embodiments are also within the protection scope of the present invention as defined by the appended claims below.

According to the present invention as described above, the following effects can be expected.

First, the metal core and the plastic are combined to reduce the weight of the entire manhole cover, and since the external exposure of the metal core is blocked, the manhole cover can suppress electric shock accidents in rainy weather while improving durability due to corrosion protection.

Second, by using a mold having a structure in which the upper frame is accommodated as the lower frame, the manhole cover which is combined with the metal core and the plastic can be manufactured with excellent quality, and can be easily produced while easily demolding the molded manhole cover.

Claims (12)

As a manhole cover formed of plastic to include a horizontal plate (100a) and a reinforcement (100b) formed on the lower surface of the horizontal plate (100a), Composite manhole cover, characterized in that the metal and plastic are produced integrally while placing the metal core 110 inside the reinforcement bar (100b). In claim 1, The horizontal plate 100a A first plastic layer 120 on the reinforcement bar 100b; A fibrous mat 130 on the first plastic layer 120; And, A second plastic layer 140 formed by mixing a luminous body or a photoluminescent body on the fiber mat 130; Composite manhole cover, characterized in that comprising a. In claim 2, The horizontal plate (100a) is a composite manhole cover, characterized in that the upper surface is reinforced with a reinforcing fiber cloth (150). The method according to any one of claims 1 to 3, Composite manhole cover, characterized in that the metal core 110 is produced so as to protrude above the reinforcement bar (100b) to be located inside the horizontal plate (100a). The method according to any one of claims 1 to 3, The metal core 110 is a composite manhole cover, characterized in that the connection hole (111a) or connecting groove (111b) is formed. As a mold for manufacturing the manhole cover of claim 1, comprising a horizontal plate (100a) and a reinforcement (100b) formed on the lower surface of the horizontal plate (100a), A horizontal plate groove 210a and a reinforcement groove 100b in the shape of a horizontal plate 100a are formed as a manhole cover groove in the center of the upper surface, and in the reinforcement groove 210b. A lower frame 210 having a through hole 211 having a size smaller than the width of the reinforcement groove 210b so as to extend to the bottom of the lower surface; An upper frame 220 having a crimping portion 221 protruding to fit into the horizontal plate groove 210a of the lower frame; And, An ejector pin 230 inserted into the through hole 211 of the lower frame; Mold for the production of composite manhole cover, characterized in that comprising a. In claim 6, The ejector pin 230 A first pin 230a disposed only in the through hole 211 of the lower frame; and The first end 231 is formed at a position coincident with the bottom of the reinforcing rib groove 210b by passing through the through-hole 211 of the lower frame and extending to the reinforcing rib groove 210b and the horizontal plate groove 210a. A second pin 230b having a second end 232 formed at an intermediate position of the reinforcement groove 210b; Mold for the production of composite manhole cover, characterized in that comprising a. In claim 6 or 7, The lower frame 210 is a mold for the production of a composite manhole cover, characterized in that the horizontal plate groove 210a and the reinforcement groove groove 210b is formed with a reverse slope that becomes narrower as the width goes down. In manufacturing the composite manhole cover, (A) preparing a metal core 110 having a thickness less than the width of the through-hole 211 while the mold for manufacturing the composite manhole cover of claim 6 and the reinforcement groove 210b of the mold lower frame. step; (b) inserting the metal core 110 into the reinforcement groove 210b of the mold lower frame; (c) filling the molten plastic into the reinforcing bar groove 210b and the horizontal plate groove 210a of the mold lower frame; (d) arranging the mold upper mold 220 over the mold lower mold 210 to press the molten plastic filled in the mold lower mold 210 with the pressing part 221 of the mold upper mold; (e) removing the mold upper mold 220; And, (f) demolding the mold lower mold 210 by pushing the ejector pin 230; Composite manhole cover manufacturing method characterized in that it comprises a. In claim 9, The metal core 110 is a composite manhole cover manufacturing method, characterized in that the plastic coating. The method of claim 9 or 10, Step (c) is Firstly filling the molten plastic; Covering the fiber mat 130; Secondly filling the molten plastic; And, Covering the reinforcing fiber cloth 150; Composite manhole cover manufacturing method characterized in that it comprises a. The method of claim 9 or 10, The ejector pin 230 of the mold has a first pin 230a disposed only in the through hole 211 of the lower frame; and the reinforcing rib groove 210b and the horizontal plate groove passing through the through hole 211 of the lower frame. The second pin having a second end 232 formed at an intermediate position of the reinforcing rib groove 210b while being formed to extend to 210a and having the first end 231 formed at a position coinciding with the bottom of the reinforcing rib groove 210b. 230b; The metal core 110 has a stepped groove 112 formed at a portion of the mold ejector pin 230 that meets the second pin 230b, so that the stepped groove is the second end 232 of the second pin 230b. The composite manhole cover manufacturing method, characterized in that is inserted into the reinforcement rib groove (210b) of the mold lower frame.

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