Patent ID: 8876582

Claim:
A ventilation device comprising: a body, a fan disposed in the body, and an adapter connected with an air outlet of the body, wherein: a first pipe coupling part, a first protruding circular ring, a second pipe coupling part and a second protruding circular ring are disposed in sequence from a side of an air outlet of the adapter to a side of an air inlet of the adapter, and the first and second pipe coupling parts are provided with the first and second protruding circular rings, respectively, wherein the each of the first and second protruding circular rings of the respective first and second pipe coupling parts has a diameter larger than a diameter of the respective first and second pipe coupling part at a root of the respective first and second pipe coupling part; an air guide structure is disposed in the adapter, a pipe is fitted over one of the first and second pipe coupling parts and is abutted against one of the first and second protruding circular rings at the root of the one of the first and second pipe coupling parts so that the pipe is fixed, and the air guide structure has an end, wherein the end of the air guide structure is engaged to an inside of the first protruding circular ring, wherein the first pipe coupling part is located on the side of the air outlet of the adapter, wherein a diameter difference between the first pipe coupling part and the first protruding circular ring is smaller than a diameter difference between the first protruding circular ring and the second pipe coupling part, and a diameter difference between the second pipe coupling part, and the second protruding circular ring is smaller than a diameter difference between the first protruding circular ring and the second pipe coupling part, and wherein a first inner diameter of the air guide structure at a first end of the air guide structure is the same as an inner diameter of the first pipe coupling part, and a second inner diameter of the air guide structure at a second end of the air guide structure is the same as an inner diameter of the air body outlet of the ventilation device, so that air smoothly transits between the body air outlet and the first pipe coupling part, and wherein the second inner diameter of the air guide structure is larger than the first inner diameter of the air guide structure.