Abstract: In a method of machining a work in a numerically controlled lathe, it is possible to reduce machining cost by shortening idle time at the time of switching and to enhance the lifetime by lessening a load on a feeding mechanism of a tool rest. After completion of the machining of a work W with a tool T1 on one tool rest (13), the one tool rest (13) is moved to a standby position B and, at the same time, the other tool rest (15) is moved from a standby position D and the feed speed of the other tool rest (15) is controlled such that the one and the other tool rests (13, 15) simultaneously reach positions C and F preset between the work W and the standby positions B and D.

Abstract: An automatic lathe is provided which is capable of rapidly and easily switching between machining of a material with a guide bush and machining of the material without the guide bush. The automatic lathe has a head stock (6) and a guide bush support table (1). The head stock (6) is provided with a spindle drive motor (8). The guide bush support table (1) is provided with a guide bush rotating motor (11). There are provided: support table fixing means (15) for positioning and fixing the guide bush support table (1); a guide member (12) rotatably installed on the guide bush support table (1) and regulated so as not to move forward and backward and having a through-hole formed for a spindle (3) to be inserted therein; a guide bush (4) detachably fitted to the tip of the guide member (12); and spindle fixing means (37) for positioning and fixing the spindle (3) on the guide bush support table (1) at a specified position when the guide bush (4) is removed from the guide member (12).

Abstract: At the time of two-dimensionally moving a mobile body of a machine tool, to a predetermined position, a speed of the mobile body is gently increased/decreased at an acceleration/deceleration equal to or less than the maximum acceleration/deceleration, from the time when the mobile body reaches a direction change point. Therefore, the moving time is shortened and a rapid acceleration/deceleration may be avoided.

Abstract: An automatic lathe is provided which is capable of rapidly and easily switching between machining of a material with a guide bush and machining of the material without the guide bush. The automatic lathe has a head stock (6) and a guide bush support table (1). The head stock (6) is provided with a spindle drive motor (8). The guide bush support table (1) is provided with a guide bush rotating motor (11). There are provided: support table fixing means (15) for positioning and fixing the guide bush support table (1); a guide member (12) rotatably installed on the guide bush support table (1) and regulated so as not to move forward and backward and having a through-hole formed for a spindle (3) to be inserted therein; a guide bush (4) detachably fitted to the tip of the guide member (12); and spindle fixing means (37) for positioning and fixing the spindle (3) on the guide bush support table (1) at a specified position when the guide bush (4) is removed from the guide member (12).

Abstract: A method of machining a work in a numerically controlled lathe is provided which is capable of reducing the machining cost by shortening idle time at the time of switching and which is capable of enhancing the lifetime by lessening a load on a feeding mechanism of a tool rest. After completion of the machining of a work W with a tool T1 on one tool rest (13), the one tool rest (13) is moved to a standby position B and, at the same time, the other tool rest (15) is moved from a standby position D and the feed speed of the other tool rest (15) is controlled such that the one and the other tool rests (13, 15) simultaneously reach positions C and F preset between the work W and the standby positions B and D.