Tool Changer

摘要

A tool changer includes a holding member having a tool change arm, a rotating mechanism for rotating the holding member, a forward/backward moving mechanism for moving the holding member forward and backward, and a controller controlling the mechanisms. A zero return controller determines whether the tool change arm is holding tools. When it is not holding tools, the tool change arm is rotated to a predetermined non-interference angle, the tool change arm is translated to a forward/backward movement zero point, and the tool change arm is rotated to a rotation zero point. When it is holding tools, the tool change arm is translated to a forward end, the tool change arm is rotated to position it on an expected path, and the tool change arm is moved along the expected path, thereby moving the tool change arm to the rotation zero point and the forward/backward movement zero point.

主权项

1. A tool changer changing a tool attached to a spindle of a machine tool with a next tool positioned at a standby position, comprising:
a holding member disposed to have a center axis parallel to an axis of the spindle and provided to be rotatable about the center axis and to be movable in a direction along the axis of the spindle; a rotating mechanism including a rotation servo motor and rotating the holding member in normal and reverse directions about the center axis by using power of the rotation servo motor; a forward/backward moving mechanism including a forward/backward movement servo motor and moving the holding member forward and backward in the direction along the axis of the spindle by using power of the forward/backward movement servo motor; a tool change arm having at least two arm portions each disposed on the holding member to extend in a radial direction with respect to the center axis of the holding member and each having a tool holding part having an opening in a side surface thereof facing the normal rotation direction of the holding member, the arm portions holding the tools with the tool holding parts in such a manner that axes of the tools are parallel to the center axis of the holding member; and a controller numerically controlling the rotation servo motor with respect to a rotation zero point set at a predetermined angular position in a rotational direction about the center axis to rotate the holding member and the tool change arm, and numerically controlling the forward/backward movement servo motor with respect to a forward/backward movement zero point set at a predetermined position in the direction along the axis of the spindle to move the holding member and the tool change arm forward and backward, thereby causing the tool change arm to execute a change operation in which the tool holding parts of the tool change arm move on a predetermined path, the controller further including a zero return controller returning the tool change arm to the rotation zero point and the forward/backward movement zero point when the change operation executed by the tool change arm is stopped halfway, the zero return controller being configured to execute a first processing of determining whether the tool holding parts of the tool change arm are holding the tools, a second processing of, when it is determined in the first processing that the tool holding parts are not holding the tools, rotating the tool change arm to a non-interference angle, and subsequently moving the tool change arm backward to the forward/backward movement zero point and then rotating the tool change arm to the rotation zero point, the non-interference angle being a predetermined angle to which the tool change arm can be rotated without interference with other structures and at which the tool change arm does not interfere with the other structures even when the tool change arm is moved forward or backward, and a third processing of, when it is determined in the first processing that the tool holding parts are holding the tools, moving the tool change arm to a position corresponding to a forward end of the path along the forward/backward movement direction, and, if the tool holding parts are not positioned on the path, subsequently rotating the tool change arm so as to position the tool holding parts on the path, and then moving the tool change arm so that the tool holding parts follow the path, thereby moving the tool change arm to the rotation zero point and the forward/backward movement zero point.