| 摘要 |
PURPOSE:To prevent a microwave from leaking, to improve operability and to improve safety by covering the opening of a circular waveguide with a metal cylinder when a cover is closed, and bringing it into pressure contact with an elastic material. CONSTITUTION:A cover 6 is opened, a microwave permeable vessel 1 filled with cereal grains 2 such as corn is disposed on a retainer 9 in a circular waveguide 8, and the cover 6 is then closed. Since a cylinder 10 is biased downward by springs 19, 20, its lower edge is brought into pressure contact with a body 7, and a microwave is effectively prevented from leaking by the operation of a choke 18. When a magnetron 4 is energized to be oscillated, generated microwave is passed through a rectangular waveguide 5 to be propagated into the waveguide 8 for forming a heating chamber 3. The grains of the corn 2 in the vessel 1 absorbs the microwave to be heated, and exploded to become popcorn. In this case, the grains 2 jumped above the cylinder 10 are returned to the vessel 1 since a ring 22 having a taper is disposed directly above the vessel 1. |
