| 摘要 |
PROBLEM TO BE SOLVED: To provide a blower capable of sufficiently adapting to pressure accuracy required for a blast device or the like using a pressure switch that is inexpensive as a pressure detecting means and is not affected by noise,and the blast device allowing high machining accuracy using the blower. SOLUTION: The blower 5 has a frequency converter 14 capable of adjusting output frequency and the pressure detecting means 12 for detecting pressure of a suitable part on the discharge side and controls driving rotation speed. In discharge control of the blower 5, as the pressure detecting means 12, at least two pressure switches for detecting whether or nor the pressure lies within a pressure detecting range between preset upper limit and lower limit and outputs on or off are used. The pressure detecting ranges detected by the respective pressure switches are set to be partially overlapped, a discriminable pressure area is fragmented by combining outputs from respective pressure switches, and the output frequency of the frequency converter 14 is adjusted in response to the respective fragmented pressure areas, thereby controlling the driving rotation speed of the blower 5.
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