| 摘要 |
PURPOSE:To surely prevent a gas compressor from being operated while being unloaded at the time of abnormal conditions by providing a means which introduces high pressure gas into an operating chamber when abnormal conditions are detected in a capacity control device. CONSTITUTION:In a capacity control device for a multi-cylinder type gas compressor, each cylinder is provided with an unloader cylinder 9, and an unloader piston 10 coupled in the unloader cylinder 9 is vertically moved in response to the pressure difference between the pressure of control gas in an operating chamber 16 and the average cylinder pressure within a chamber 19. This thereby allows the capacity of the gas compressor to be continuously changed in a stepless manner. In this case, a passage change over valve 31 is disposed onto a gas pipe line 30 which leads control gas to the operating chamber 16, and discharge gas within a discharge chamber 8 is introduced into the passage change-over valve 31 by means of a pipe line 32. When the abnormal conditions of the capacity control device are detected by a controller 33 based on outputs from various sensors 34, 35 and the like, the passage change-over valve 31 is switched, and high pressure gas within the discharge chamber 8 is introduced into respective working chambers 16, so that a gas compressor is thereby operated while being fully loaded. |
