Abstract: A waste exhaust ventilation door automatic control device comprises a core body (8), an inner door body (2) and an outer door body (1); wherein the core body is fixed on a ventilation opening of the waste exhaust ventilation door, a top of the outer door body is movably hinged on an outer side of the core body, and a bottom of the inner door body is movably hinged on an inner side of the core body; when there is no pressure fluctuation outside the core body, the outer door body and inner door body will open, and when there is pressure fluctuation outside the core body, the outer door body and/or the inner door body will be closed automatically due to a pressure difference between inside and outside the core body. A vehicle body comprising the waste exhaust ventilation door automatic control device is also provided.

Abstract: A waste exhaust ventilation door automatic control device comprises a core body (8), an inner door body (2) and an outer door body (1); wherein the core body is fixed on a ventilation opening of the waste exhaust ventilation door, a top of the outer door body is movably hinged on an outer side of the core body, and a bottom of the inner door body is movably hinged on an inner side of the core body; when there is no pressure fluctuation outside the core body, the outer door body and inner door body will open, and when there is pressure fluctuation outside the core body, the outer door body and/or the inner door body will be closed automatically due to a pressure difference between inside and outside the core body. A vehicle body comprising the waste exhaust ventilation door automatic control device is also provided.

Abstract: A vehicle body structure and a rail train with the vehicle body. The vehicle body structure includes a vehicle body, an air duct and a maintenance portion, wherein the air duct is provided at the bottom of the vehicle body, the air duct has a maintenance port, the maintenance portion is connected to the air duct and located at the maintenance port, and the maintenance portion has an opening position for opening the maintenance port and a closing position for closing the maintenance port. By operating a maintenance portion on an air duct at the bottom of a vehicle body, a maintenance port of the air duct is at an opened or closing position, in order to detect or repair the interior of the air duct, thus prolonging the life of the air duct of the vehicle body structure and improving the reliability.