Toyoda Koki Kabushiki Kaisha

Akihiro Matsuura

Hiroyuki Nakano

Toshiharu Takashima

Takani Yoshimi

Tomoyasu Imai

Kunimichi Nakashima

Tetsuro Yamakage

Minoru Enomoto

Toshihiro Tsutsui

Yoshio Doi

Shinji Tange

A machine tool having a grinding wheel for grinding a workpiece mounted on a table. The machine tool is provided with a truing apparatus for truing the grinding wheel and a measuring device for measuring the diameter of the grinding wheel after every truing operation. Both of the truing apparatus and the measuring device are mounted on a movable base. The movable base is moved between its retract position at the outside of the table and a forward position above the table. The movable base is move to the forward position to bring the truing apparatus and the touch sensor into predetermined positions for truing and measuring operations. After the truing and measuring operations, the movable base is moved away from the table and is retracted to its retract position. The truing apparatus is provided with a truer support shaft whose rotational shaft intersects with a horizontal plane with an angle of 45.degree., and a truer attached to the truer support shaft. The truer has a cylindrical abrasive layer formed at periphery thereof and extending along a conical plane having a top angle of 90.degree..

Machine tool capable of grinding a workpiece with a truing apparatus

A thermal displacement compensating apparatus capable of compensating for the thermal displacement of the main spindle of a machine tool is disclosed. A feed back scale and a measuring head are provided in order to detect the actual position of the front end portion of the spindle head. Furthermore, a distance sensor is provided for detecting the thermal extension of the main spindle with respect to the spindle head. The output signal from the distance sensor is used for modifying the present position detected by the measuring head or modifying a commanded target position. With this arrangement, a tool attached to the front end portion of the main spindle is moved to the commanded position regardless of the thermal displacement of the spindle head and the main spindle. Another type of compensation apparatus is also disclosed, wherein the measuring head is mounted on a mounting rod, and the mounting rod is automatically moved so as to maintain the distance between the measuring head and the front end surface of the main spindle at a constant distance. With this arrangement, actual position of the front end surface of the main spindle can directly be detected regardless of the thermal displacement of the spindle head and the main spindle.

Apparatus for compensating for the thermal displacement of the main

A machine tool having an automatic tool changer for transferring tools between a tool magazine and a horizontal tool spindle rotatably mounted in a spindle head and which includes a vertical head which rotatably carries a vertical tool spindle and a horizontal drive shaft connected thereto is removably mounted on a vertical head support. In advance of a machining operation on a top surface of a workpiece, relative movement between the vertical head support and the spindle head is effected in a vertical direction and first and second horizontal directions, so that the vertical head is mounted on the spindle head, with the drive shaft being drivingly connected with the horizontal tool spindle. A tool support station mounted on the vertical head support is provided with two tool grippers each for vertically holding a tool. The tool support station is brought under the vertical head being mounted on the spindle head and selectively presents the two tool grippers in vertical axial alignment with the vertical tool spindle. In this state, the spindle head is moved in the vertical direction and the axial direction of the horizontal tool spindle and enables the vertical tool spindle to return a used tool therefrom to one of the tool grippers and then, to receive therein a new tool from the other tool gripper. A tool transfer device, which cooperates with the tool changer to receive a new tool therefrom and hand over a used tool thereto, is provided between the tool changer and the tool support station and transfers tools therebetween.

Machine tool with tool change function

A digitally controlled grinding machine provided with a rest apparatus which is opposed to a wheel head, carrying a grinding wheel, for supporting against grinding resistance a workpiece rotatable on a support device, and with a measuring device, which outputs first and second size signals to a digital feed controller respectively when the workpiece is ground to first and second predetermined sizes. The feed controller controls a first servomotor to advance a pair of shoes of the rest apparatus until the first size signal is output and also controls a second servomotor to advance the wheel head until the second size signal is output. The controller, when receiving the second size signal, controls the first servomotor to retract each of the shoes by a predetermined retraction amount, being set in a digital switch, from an advanced end position which is adjusted in dependence upon the first size signal and in a successive grinding cycle, controls the first servomotor to start the advance feed of each of the shoes from a retracted end position which is spaced by the predetermined retraction amount from the advanced end position, so that compensation is made for wear of the shoes.

Digitally controlled grinding machine with rest apparatus

An apparatus for preventing circumferential overspeeding of a grinding wheel is provided in which first and second rejection members, pivotably carried respectively on a motor base and a wheel head, are connected with each other through a transmitting mechanism. The mechanism is arranged to prevent, by the first rejection member, the attachment of a large diameter pulley to a motor on the motor base when a grinding wheel with a maximum useable diameter, or one having a diameter greater than a predetermined pulley exchange diameter, is on a wheel spindle of a wheel head, without interference with the second rejection member. A parallel motion mechanism is incorporated in the transmitting mechanism so that the same may transmit pivotal movement of the first rejection member to the second rejection member without being affected by movement of the motor base on the wheel head.

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Chiryu, Japan

Akihiro Matsuura