JP2001315816A - Synthetic resin manhole cover for septic tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin manhole cover for a septic tank which is improved in strength and can be recycled satisfactorily. SOLUTION: The manhole cover 7 to be set for covering the manhole of a septic tank is formed in a structure wherein the outer circumference of its core material 7a made of FRP(fiber reinforced plastics) is made up from a surrounding material 7b made of PP(polypropylene).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin manhole cover for a septic tank.

[0002]

2. Description of the Related Art Conventionally, manhole covers used in septic tanks for home use or the like are often made of PP (polypropylene) or FRP. The FRP manhole cover is sticky and excellent in strength, but when it is treated as waste material, it needs to be incinerated or landfilled, which has a problem in waste material treatment.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a resin manhole cover for a septic tank which has high strength and can be recycled. The first gist of the present invention is to provide a manhole cover for covering a manhole opening of a septic tank, wherein the manhole cover is formed by forming an outer periphery of a core material made of FRP by PP (polypropylene). is there. A second gist is that the core material is a cut material that is cut and separated when the manhole opening of the septic tank main body is formed.

[0004]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective configuration diagram of a septic tank made of FRP used for home use or the like. The septic tank 1 is divided into an upper member 2 and a lower member 4, and is integrated later.
Manhole openings 3a, 3b, 3c are formed on the upper surface of the upper member 2.

The upper member 2 of the septic tank 1 is manufactured by using a mold 5 shown in a schematic view of FIG. 2, and is provided on a surface of the mold 5 in which manholes M1, M2 and M3 are integrally formed one step higher. , FRP is sprayed to form an FRP layer P,
After the FRP layer P is formed, the manhole portions M1, M2, and M3 are cut vertically so that the manhole portions 3a, 3b, and 3c are formed through the manhole portions M1, M2, and M3. However, at this time, the manhole 3a,
The cut materials corresponding to the dimensions and shapes of 3b and 3c are separated.

As shown in FIG. 3, the manhole openings 3a, 3b, 3c are respectively provided with manhole frames 6, 6,
6 is fixed, and for these manhole frames 6, 6, 6,
Manhole covers 7, 7, 7 are attached from above, respectively, and the manhole covers 3, 7, 7
a, 3b and 3c are covered.

In this embodiment, each manhole cover 7 has a cross-sectional structure as shown in the cross-sectional enlarged view of FIG. 4, and has a core material 7a made of FRP at a central portion, and its outer periphery is made of PP (polypropylene). It is formed of a peripheral member 7b made of stainless steel. That is, the outer periphery of the core material 7a is coated with PP (polypropylene) using a mold to form the manhole cover 7 as shown in the sectional view of FIG.
As the core material 7a, the cut material separated at the time of forming the manhole openings 3a, 3b, 3c is used as it is.

Conventionally, manhole openings 3a, 3b, 3c
The cut material separated at the time of formation was incinerated or landfilled as a waste material. By making effective use of this cut material and forming the core material 7a of the manhole cover 7, the whole is made of PP. The manhole cover 7 is more sticky than the manhole cover 7, and the strength is increased as a whole, and the stickiness is increased, and when it is broken, it does not crack and the safety is improved.

Incidentally, as shown in FIG. 4, in addition to forming an outer peripheral member 7b made of PP around the outer periphery of the core member 7a, PP and F
In order to prevent the RP from peeling off, the core material 7a may be formed with an uneven portion or a structure in which a hole is formed. In short, the cut material that has been conventionally discarded is effectively used,
The manhole cover can be formed using the cut material as a core material.

The manhole cover 7 using such a core material 7a made of FRP can be used as a fuel for producing cement at a cement factory, for example, at the time of disposal, and the outer peripheral material 7b can be used as a heat source. Since it is a plastic PP, the calorific value becomes large, and it can be used as a good fuel.

Incidentally, in the case of only FRP, the heat source is about 2000 to 3000 Kcal / kg due to the influence of the filler, which is too small as a heat source for producing cement.
In the case of PP only, the heat source is about 9000 Kcal
/ kg and 500 by mixing FRP and PP.
A heat source of 0 Kcal / kg or more can be secured, and it can be an acceptable fuel for cement production.

[0012] The remaining scum after incineration as a fuel is mainly composed of silica (SiO ₂ ) and charcoal (Ca).
O) and other materials such as alumina and magnesium oxide (Mg)
O), and the silica (SiO ₂ ) and calcium carbonate (CaO) are raw material components of cement.
The remaining scum can be effectively used as a cement raw material. Thus, the manhole cover 7 can be effectively recycled and can be effectively used as a fuel and a raw material at the time of cement production or the like.

[0013]

According to the present invention, there is provided a manhole cover for covering a manhole opening of a septic tank, wherein the manhole cover is made of FRP.
Since the core material is made of PP (polypropylene), the core material is made of FRP, it is sticky, has increased strength and does not crack with "crispness" and improves safety It will be.

Further, since the core material is a cut material which is cut and separated at the time of forming the manhole opening of the septic tank main body, the cut material which has been conventionally discarded material is favorably used, and the manhole cover is formed. It has the effect that it can be reused as a core material.

[Brief description of the drawings]

FIG. 1 is a perspective configuration diagram of a septic tank.

FIG. 2 is a schematic cross-sectional configuration diagram showing a manufacturing process of an upper member of the septic tank in FIG.

FIG. 3 is a schematic cross-sectional configuration diagram in a state where a manhole opening is cut and formed after demolding and a manhole cover is attached.

FIG. 4 is an enlarged cross-sectional configuration diagram of a manhole cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Septic tank 2 Upper member 3a, 3b, 3c Manhole opening 6 Manhole frame 7 Manhole cover 7a Core material 7b Outer peripheral material

Claims (2)

[Claims] 1. A manhole cover for covering a manhole opening of a septic tank, wherein the manhole cover is made of a core material made of FRP and made of PP (polypropylene). Resin manhole cover. 2. The resin manhole cover for a septic tank according to claim 1, wherein the core material is a cut material that is cut and separated when the manhole opening of the septic tank body is formed.