| 摘要 |
PURPOSE:To facilitate working of the cylinder provided with recess on the internal circumference thereof by a method wherein an inner tubular body is formed by piling multiple elements having the same configuration and the positions of all elements are deviated sequentially in the circumferential direction thereof to arrange the recesses on the internal circumferential surfaces into spiral configuration. CONSTITUTION:Engaging recesses 12 are semi-circular or square and are engaged with a pin 14 or a key provided on the inner peripheral surface of an outer tubular body 7 to preclude the turning of the elements 10 with respect to the outer tubular body 7. The engaging recesses 12 of respective elements 10 are deviated slightly in the phases with respect to the recesses 13 of respective elements and when the engaging recesses 12 of respective elements 10 are engaged with one piece of pin 14, the recesses 13 are arranged so as to describe a screw in the axial direction of the cylinder and more than one set of continuous spiral recesses are formed by all of the elements 9. The cylinder is formed by inner and outer tubular bodies in such manner and the inner tubular body is formed by piling multiple elements of the same configuration in the axial direction thereof, therefore, the cylinder may be worked simply by a conventional machine tool. |
