Automatic opening and closing device for channel cover plate

An automatic channel cover plate opening and closing device comprises a cover plate arranged on a platform channel opening and hinged to a platform through a bearing, a crawling ladder passing through the channel opening and a climbing-free device sliding up and down on the crawling ladder, a rack is arranged on the top of one side of the climbing-free device, and a first synchronous gear is arranged on a crawling ladder holder below the platform. A second synchromesh gear and a gear shaft are arranged on the ladder stand retainer above the platform, the gear shaft is sequentially sleeved with a spring and a gear, a third synchromesh gear is arranged at one end of the bearing, the first synchromesh gear is meshed with the third synchromesh gear through a first chain, and the third synchromesh gear is meshed with the second synchromesh gear through a second chain; the rack moves up and down on the crawling ladder along with the climbing-free device and is discontinuously meshed with the first synchronous gear