| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the holding amount of the end part of a needle thread by a needle thread holder changes when the rotation speed of a main shaft suddenly changes during the operation of a needle thread holding operation.SOLUTION: When a main shaft rotation angle A is equal to A3 in S10 (S10;Yes), a controller turns a speed change flag F1 to 1 (S16), and determines whether or not the rotation angle B of a pulse motor for needle thread holding is equal to B0 (S17). When the rotation angle B of the pulse motor for needle thread holding is equal to B0 (S17;Yes), the controller inhibits the change of the rotation speed of a sewing machine motor. Thus, processing is shifted to S12 while the main shaft maintains the present rotation speed. Meanwhile, when the rotation angle B of the pulse motor for needle thread holding and B0 are not equal (S17;No), the controller changes the rotation speed of the main shaft by changing the rotation speed of the sewing machine motor so as to reach the rotation speed of the main shaft indicated by a setting value. |
