Maintenance window locking device

A maintenance window locking device, comprising:

• a maintenance window body, a maintenance window cover, a fastening plate, a first limiting mechanism comprising a groove, and a roller, wherein
• the fastening plate comprises a fastening plate body and a pin which are of an integrated structure;
• the pin is rotatably connected to the roller;
• the maintenance window body is hinged to a first end of the maintenance window cover;
• the fastening plate body is rotatably connected to a second end of the maintenance window cover;
• the first limiting mechanism is located on the maintenance window body;
• the fastening plate body is configured for driving the maintenance window cover to move toward the maintenance window body, so as to allow the roller to roll along the first limiting mechanism until the roller is clamped into the groove, to tightly attached the maintenance window cover with the maintenance window body;
• wherein a latching device is arranged on the fastening plate body, and a second limiting mechanism matched with the latching device is arranged on the maintenance window cover, and
• wherein the latching device comprises a spring lock hook, and the second limiting mechanism is a baffle plate.