JP2973281B2 - Plastic manhole cover - Google Patents
Plastic manhole coverInfo
- Publication number
- JP2973281B2 JP2973281B2 JP7347644A JP34764495A JP2973281B2 JP 2973281 B2 JP2973281 B2 JP 2973281B2 JP 7347644 A JP7347644 A JP 7347644A JP 34764495 A JP34764495 A JP 34764495A JP 2973281 B2 JP2973281 B2 JP 2973281B2
- Authority
- JP
- Japan
- Prior art keywords
- plastic
- manhole cover
- metal
- metal rod
- reinforced
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Landscapes
- Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は補強材をインサート
して補強したプラスチック製マンホール蓋に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic manhole cover reinforced by inserting a reinforcing material.
【０００２】[0002]
【従来の技術】現在、マンホールの蓋は鋳鉄製が主流で
あるが、軽量化やコストダウンを目指してプラスチック
化したものもある。しかしながら、プラスチックは鋳鉄
に比較して剛性が大幅に劣るので、グラスファイバーで
補強した所謂強化プラスチック材を使用し、さらに肉厚
を大幅に厚くすることで剛性を持たせている。2. Description of the Related Art At present, manhole covers are mainly made of cast iron, but some are made of plastic in order to reduce the weight and cost. However, plastics have much lower rigidity than cast iron. Therefore, a so-called reinforced plastic material reinforced with glass fiber is used, and the rigidity is increased by further increasing the wall thickness.
【０００３】上記のようにグラスファイバーで強化した
強化プラスチックは廃棄するときのリサイクルが難し
く、なお且つ、焼却処分もグラスファイバーが残渣とな
りその処分が困難となるので、できるだけグラスファイ
バー強化プラスチックは使用しない方向に進んでいる。
また、肉厚を厚くすることはプラスチック材を用いるこ
とによるコスト面でのメリットが著しく減少するという
問題もある。[0003] Reinforced plastic reinforced with glass fiber as described above is difficult to recycle when discarded, and glass fiber residue remains in incineration, making disposal difficult. Therefore, glass fiber reinforced plastic is not used as much as possible. You are moving in the direction.
In addition, there is a problem that increasing the thickness significantly reduces the cost advantage of using a plastic material.
【０００４】[0004]
【発明が解決しようとする課題】そこで、プラスチック
のＲＩＭ成形（反応射出成形）の長所を利用し、グラス
ファイバーを含まない非強化プラスチックに金属パイプ
等の金属製棒状体の補強材をインサートして上記問題の
解決を図ろうとした。しかしながら、単純に厚肉部にパ
イプ等の補強材を全長にわたってインサートしたので
は、プラスチックの成形収縮のため、該プラスチックと
補強材との間に大きな応力が掛かり、製品にかなりの反
りが発生するという問題がある。Therefore, taking advantage of the advantages of plastic RIM molding (reaction injection molding), a metal rod-like reinforcing material such as a metal pipe is inserted into a non-reinforced plastic containing no glass fiber. We tried to solve the above problem. However, if a reinforcing material such as a pipe is simply inserted into the thick part over the entire length, a large stress is applied between the plastic and the reinforcing material due to the molding shrinkage of the plastic, and the product is considerably warped. There is a problem.
【０００５】本願発明は上述の点に鑑みてなされたもの
で上記問題点を除去し、製品に反りが発生することのな
い金属製棒状体で補強したプラスチック製マンホール蓋
を提供することを目的とする。[0005] The present invention has been made in view of the above points, and has as its object to provide a plastic manhole cover reinforced by a metal rod-like body which does not warp the product, eliminating the above problems. I do.
【０００６】[0006]
【課題を解決するための手段】上記課題を解決するため
請求項１に記載の発明は、補強材をインサートして補強
したプラスチック製マンホール蓋であって、補強材に金
属製棒状体を用い、該金属製棒状体をマンホール蓋の裏
面側に部分的にインサートすると共に、インサート部分
の外周にプラスチックが成形収縮する際、該プラスチッ
クと該金属製棒状体との間に掛かる応力を吸収する金属
テープ又は樹脂テープ又は潤滑材からなる応力吸収部材
を設けたことを特徴とする。According to the first aspect of the present invention, there is provided a plastic manhole cover reinforced by inserting a reinforcing material, wherein a metal rod is used as the reinforcing material. the metallic rod-shaped body with partially inserted into the rear surface side of the manhole cover, the insert part
When plastic shrinks around the periphery of the plastic, the plastic
Metal that absorbs the stress applied between the metal and the metal rod
Stress absorbing member made of tape or resin tape or lubricant
Is provided .
【０００７】[0007]
【０００８】[0008]
【０００９】[0009]
【発明の実施の形態】以下、本願発明の実施の形態を図
面に基づいて説明する。図１は本願発明に係るプラスチ
ック製マンホール蓋の構造を示す図で、図１（ａ）は平
面図、図１（ｂ）はＡ−Ａ断面、図１（ｃ）はＢ−Ｂ断
面である。図示するように、マンホール蓋１はＲＩＭ成
形法で形成したプラスチック製であり、表側には格子状
の凹凸模様２が形成され、裏側には幅方向に複数本（図
では４本）の補強リブ３が設けられ、該補強リブ３を貫
通して金属製棒状体（例えばＳＵＳ３０４パイプ）４が
インサートされている。Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are views showing the structure of a plastic manhole cover according to the present invention. FIG. 1A is a plan view, FIG. 1B is an AA section, and FIG. 1C is a BB section. . As shown in the figure, the manhole cover 1 is made of plastic formed by a RIM molding method, a lattice-shaped uneven pattern 2 is formed on the front side, and a plurality of (four in the figure) reinforcing ribs are arranged on the back side in the width direction. A metal rod (for example, SUS304 pipe) 4 is inserted through the reinforcing rib 3.
【００１０】金属製棒状体４の補強リブ３を貫通する部
分の外表面にはアルミニウム等の金属テープ５が貼付ら
れている。このように金属製棒状体４の補強リブ３を貫
通する部分の外表面に金属テープ５を貼付ることによ
り、ＲＩＭ成形法でマンホール蓋１を成形した場合、金
属テープ５はその表面が滑らかなため、プラスチックの
成形収縮による該プラスチックと金属製棒状体４との間
に発生する応力が吸収され、マンホール蓋１に反りが発
生しない。A metal tape 5 made of aluminum or the like is attached to an outer surface of a portion of the metal rod 4 penetrating the reinforcing rib 3. When the manhole cover 1 is formed by the RIM molding method by attaching the metal tape 5 to the outer surface of the portion of the metal rod 4 penetrating the reinforcing rib 3 as described above, the metal tape 5 has a smooth surface. Therefore, the stress generated between the plastic and the metal rod 4 due to the plastic shrinkage is absorbed, and the manhole cover 1 does not warp.
【００１１】次に、プラスチック製マンホール蓋の製造
方法を図２を用いて簡単に説明する。図２に示すように
上型枠１０１と下型枠１０２の間にマンホール蓋１と同
形状の間隙１０３、リブ３と同形状の間隙１０４及び金
属製棒状体４が収容される間隙１０５が一体に形成され
ている。間隙１０５に図３に示すように、補強リブ３を
貫通する部分の外表面に金属テープ５を貼付た金属製棒
状体４を収容し、上記間隙１０３及び間隙１０４に、例
えば二液を混合した樹脂液を射出することにより、該二
液の樹脂液が反応凝固して金属製棒状体４で補強された
プラスチック製マンホール蓋が完成する。Next, a method of manufacturing a plastic manhole cover will be briefly described with reference to FIG. As shown in FIG. 2, a gap 103 having the same shape as the manhole cover 1, a gap 104 having the same shape as the rib 3, and a gap 105 for accommodating the metal rod 4 are integrally formed between the upper mold frame 101 and the lower mold frame 102. Is formed. As shown in FIG. 3, a metal rod 4 having a metal tape 5 attached to the outer surface of a portion penetrating the reinforcing rib 3 is accommodated in the gap 105, and, for example, two liquids are mixed in the gap 103 and the gap 104. By injecting the resin liquid, the two liquid resin liquids solidify by reaction, and a plastic manhole cover reinforced with the metal rod 4 is completed.
【００１２】上記のように金属製棒状体４の補強リブ３
を貫通する部分の外表面に金属テープ５を貼付ることに
より、上記のように金属テープ５はその表面が滑らかな
ため樹脂液が反応凝固して収縮する際、金属製棒状体４
と補強リブ３の間に応力が発生するが、該応力は滑らか
な金属テープ５の表面を補強リブ３が収縮により移動し
吸収され、マンホール蓋１に反りが生じない。As described above, the reinforcing ribs 3 of the metal rod 4
The metal tape 5 is adhered to the outer surface of the portion penetrating the metal rod 5 so that the metal tape 5 has a smooth surface as described above, and when the resin liquid reacts and solidifies and contracts, the metal tape 5
A stress is generated between the metal rib 5 and the reinforcing rib 3, but the stress is absorbed by the smooth movement of the reinforcing rib 3 on the surface of the metal tape 5 due to the shrinkage, and the manhole cover 1 does not warp.
【００１３】なお、上記例では補強リブ３を貫通する全
箇所（図では４箇所）に金属テープ５を貼付た例を示し
たが、両端部に金属テープ５を貼付ただけでも、反りは
殆ど発生しないことが確認できた。また、金属製棒状体
４の表面が滑らかである場合は、金属テープ５を設けな
くとも反りは発生しない。また、金属テープ５に替えて
表面の滑らかな樹脂テープを貼付たり、例えばシリコン
グリス等の潤滑材を塗布しても金属テープ５の場合と略
同様な作用効果が得られる。In the above example, the metal tape 5 is applied to all the locations (four locations in the figure) penetrating the reinforcing ribs 3. However, even if the metal tape 5 is applied to both ends, the warp is almost eliminated. It was confirmed that it did not occur. In addition, when the surface of the metal rod 4 is smooth, no warpage occurs even if the metal tape 5 is not provided. Further, even if a resin tape having a smooth surface is attached instead of the metal tape 5 or a lubricant such as silicon grease is applied, substantially the same operation and effect as in the case of the metal tape 5 can be obtained.
【００１４】上記のように金属製棒状体４で補強された
マンホール蓋１を実際にマンホール開口にかぶせ、該マ
ンホール蓋１に乗用車を乗せて、変形状態を調べたが、
実用上問題とならない範囲の変形しか観測できなかっ
た。The manhole cover 1 reinforced with the metal rods 4 as described above was actually put over the manhole opening, and a passenger car was placed on the manhole cover 1 to examine the deformation state.
Only deformation within a range that did not pose a problem in practice could be observed.
【００１５】なお、上記実施の形態例では、マンホール
蓋１の裏側中央部に一本の金属製棒状体４を用いる例を
示したが、該金属製棒状体は一本に限定されるものでは
なく、複数本の金属製棒状体を部分的にインサートする
構造としても良い。この場合のインサート部分の外周面
に金属テープ等の応力吸収部材を設ける。In the above embodiment, an example is shown in which one metal rod 4 is used at the center of the back side of the manhole cover 1; however, the number of metal rods is not limited to one. Instead, a structure in which a plurality of metal rods are partially inserted may be used. In this case, a stress absorbing member such as a metal tape is provided on the outer peripheral surface of the insert portion.
【００１６】[0016]
【発明の効果】以上説明したように請求項１に記載の発
明によれば、補強材に金属製棒状体を用い、該金属製棒
状体をマンホール蓋の裏面側に部分的にインサートする
と共に、インサート部分の外周にプラスチックが成形収
縮する際、該プラスチックと該金属製棒状体との間に掛
かる応力を吸収する金属テープ又は樹脂テープ又は潤滑
材からなる応力吸収部材を設けたので、金属製棒状体で
補強され且つ反りの小さいプラスチック製マンホール蓋
を提供できるという優れた効果が得られる。As described above, according to the first aspect of the present invention , a metal rod is used as a reinforcing material , and the metal rod is partially inserted into the back surface of the manhole cover.
At the same time, plastic is molded around the insert
When shrinking, it is hung between the plastic and the metal rod.
Metal or resin tape or lubrication to absorb such stress
Since the stress absorbing member made of a material is provided, an excellent effect of being able to provide a plastic manhole cover reinforced with a metal rod and having a small warpage can be obtained.
【００１７】[0017]
【図１】本願発明に係るプラスチック製マンホール蓋の
構造を示す図で、図１（ａ）は平面図、図１（ｂ）はＡ
−Ａ断面、図１（ｃ）はＢ−Ｂ断面である。FIGS. 1A and 1B are views showing the structure of a plastic manhole cover according to the present invention, wherein FIG. 1A is a plan view and FIG.
FIG. 1C is a cross section taken along line BB in FIG.
【図２】本願発明に係るプラスチック製マンホール蓋の
製造方法を説明するための図である。FIG. 2 is a view for explaining a method of manufacturing a plastic manhole cover according to the present invention.
【図３】補強用の金属製棒状体を示す図である。FIG. 3 is a view showing a metal rod for reinforcement.
１ マンホール蓋 ２ 格子状の凹凸模様 ３ 補強リブ ４ 金属製棒状体 ５ 金属テープ DESCRIPTION OF SYMBOLS 1 Manhole cover 2 Lattice-like uneven pattern 3 Reinforcement rib 4 Metal rod 5 Metal tape
Claims (1)
チック製マンホール蓋であって、 前記補強材に金属製棒状体を用い、該金属製棒状体を前
記マンホール蓋の裏面側に部分的にインサートすると共
に、インサート部分の外周にプラスチックが成形収縮す
る際、該プラスチックと該金属製棒状体との間に掛かる
応力を吸収する金属テープ又は樹脂テープ又は潤滑材か
らなる応力吸収部材を設けたことを特徴とするプラスチ
ック製マンホール蓋。1. A reinforcing member a plastic manhole cover which is reinforced by inserts, using a metal rod-shaped member to the reinforcement, prior to the metal rod-shaped body
Co when partially inserted into the back side of the serial manhole cover
Plastic shrinks around the insert
When it hangs between the plastic and the metal rod
Metal or resin tape or lubricant that absorbs stress
A plastic manhole cover provided with a stress absorbing member .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7347644A JP2973281B2 (en) | 1995-12-14 | 1995-12-14 | Plastic manhole cover |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7347644A JP2973281B2 (en) | 1995-12-14 | 1995-12-14 | Plastic manhole cover |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09165770A JPH09165770A (en) | 1997-06-24 |
| JP2973281B2 true JP2973281B2 (en) | 1999-11-08 |
Family
ID=18391622
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7347644A Expired - Lifetime JP2973281B2 (en) | 1995-12-14 | 1995-12-14 | Plastic manhole cover |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2973281B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4964667B2 (en) * | 2007-05-16 | 2012-07-04 | 公益財団法人鉄道総合技術研究所 | Lid with excessive internal pressure release valve |
-
1995
- 1995-12-14 JP JP7347644A patent/JP2973281B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09165770A (en) | 1997-06-24 |
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