Title:
SCREW COMPRESSOR, AND CONTROL METHOD THEREOF
Document Type and Number:
Japanese Patent JP3516108
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To prevent reduction of discharge pressure even when used air quantity exceeds a rated value in the case where a discharge pressure set value is lowered by determining the number of the highest rotation of a motor in accordance with the discharge pressure set value in a compressor main body.
SOLUTION: Compression air compressed to a specified pressure in a compressor main body 3 is discharged from discharge pipings 6. At this time, a pressure sensor 7 detects pressure of the compression air to be fed back to the number of rotation control device 8. The number of rotation control device 8 operates the operation number of rotation in accordance with used air quantity in a demanding apparatus, and an inverter 1 is controlled to control rotation of a motor 2. For a control range of the operation number of rotation in this case, the number of rotation number preliminarily set in the heighest number of rotation control device 9 based on a set pressure by a discharge pressure setting device 10 is taken as the upper limit. In this constitution, in the case where it is set at a lower pressure than a rated pressure, air quantity exceeding rated air quantity can be obtained within a motor load capacity range. Discharge pressure can thus be prevented from lowering even when the rated air quantity is exceeded.
Inventors:
Maeda, Junji
Kamiya, Yuji
Shiiki, Kazuaki
Kamiya, Yuji
Shiiki, Kazuaki
Application Number:
JP1723596A
Publication Date:
April 05, 2004
Filing Date:
February 02, 1996
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F04C18/16; F04C28/08; F04C28/28; (IPC1-7): F04C18/16; F04C29/10
Attorney, Agent or Firm:
鵜沼 辰之 （外１名）
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