| 摘要 |
The present invention relates to an engineering plastic manhole structure which utilizes mechanical properties of engineering plastics having a strength, an elasticity, and a heat resistance superior than those of steel to overcome the problems of conventional manholes produced through a casting process, such as assembly errors, movements of manholes caused by the impact loads of vehicles, water leakage and noise, and the problems of locking devices. Also, it is an object of the present invention to produce an engineering plastic manhole structure of consistent quality in an efficient and economically advantageous manner. The engineering plastic manhole structure of the present invention is characterized in that it has an elastic force of engineering plastic, and an extremely small assembly error between a manhole frame and a manhole cover, and characterized in that a locking rim and a locking groove are tightly assembled with each other with no gaps, thus enabling the present invention to function as a locking device against the impact loads of vehicles, and perfectly preventing the ingress of rainwater into the insertion space of a support frame. The assembly of the manhole frame and the manhole cover of the present invention serves as a locking device to eliminate the necessity of a locking device which might otherwise be needed for conventional manholes produced through a casting process. As the manhole frame and the manhole cover of the present invention have no gaps therebetween, noises caused by loads of vehicles in conventional manholes produced through a casting process can be prevented. |
