Toyoda Koki Kabushiki Kaisha

Hideo Nishimura

Minoru Enomoto

Takao Yoneda

Kunihiko Eto

Kuniyuki Niwa

Hisaji Nakao

Haruo Ohmura

Kunihiko Unno

Kunimichi Nakashima

Toshihiko Yomogida

Akira Tsuboi

Tamaki Tomita

Norihiko Shimizu

Yoji Kamiya

Shigeo Noda

Yasufumi Tokura

Fumihiko Ohkoshi

Kunihiko Etoh

Ikuo Otsu

Tamotsu Ishigaki

Isamu Yokoe

Masaharu Fujisaki

Kazuo Eguchi

Yasushi Yamamoto

A contact detecting apparatus for detecting the contact of a workpiece with a tool in a machine tool which includes a magnetic coil mounted on the periphery of a spindle head and connected to an AC power source for generating an induced current in a looped secondary circuit including the workpiece, a work table, a machine body, a spindle head, a tool spindle and the tool, when the workpiece and the tool are moved relatively into contact with each other. A first conductive wire forming a secondary winding of one turn is arranged in a parallel relationship with the looped secondary circuit and a current induced therein by energization of the magnetic coil. A second conductive wire is connected at one end thereof to the looped secondary circuit. A detecting device is connected to the first and second conductive wires for detecting contact between the workpiece and the tool based on the voltage induced across the first and second conductive wires.

Contact detecting apparatus

A tool position offsetting system for a spare tool, including a tool life detecting device provided for detecting a broken or substantially worn tool and for replacing the same by a spare tool, and a detecting device which detects whether the spare tool is inserted in the tool spindle. If the detecting device makes a detection, an input controlling circuit applies several signals to a numerical controller so as to instruct the same to introduce the dimensional data for the spare tool into the memory of the numerical controller, resulting in amending the offset data stored in the memory before a machining operation. After the machining operation, the input controlling circuit applies several signals so as to remove the dimensional data from the memory, resulting in restoring the tool offset data to its original setting.

Tool position offsetting system for a spare tool

A numerical control device for controlling rotation of a servomotor in response to numerical control data to move a movable member by a commanded feed amount at a commanded feed rate. A velocity detector detects an actual feed rate of the movable member. A register stores an allowable feed rate data. A comparator compares an allowable feed rate data from the register and an actual feed rate from the velocity detector to output an abnormal signal when the actual feed rate exceeds the allowable feed rate. The allowable feed rate data is set into the register each time the commanded feed rate is changed.

Numerical control device

A sequence block display system used with a programmable sequence controller for displaying a sequence block on a screen of a cathode-ray tube display unit in the form of ladder diagram. The sequence block display system is provided with a data processor and a buffer memory which includes first, second and third memories. The first memory is capable of storing the whole of sequence programs stored in the sequence controller and the second memory is capable of storing at least one sequence block. The third memory is adapted to store output instructions, which are used to designate a sequence block, in the same order as each designated sequence block is displayed on the screen and further to read out the output instructions in the reverse order for displaying the sequence blocks which are put out of the screen.

Sequence block display system

A numerical controller having a digital computer with a memory device, a feed control device responsive to feed control data supplied from the computer for controlling the servomechanisms of a grinding machine, a data write-in device manually operable for inputting various data and instructions, and a plurality of pilot lamps controllable by the computer. The write-in device is operable to input grinding mode designation data, responsive to which the computer serves to illuminate one by one those of the lamps which request the operator to input control parameters necessary for the grinding control in the designated grinding mode. The write-in device is further operable to input the control parameters designated by the illuminated lamps for storage in the memory device. The memory device has stored therein a number of operational sequence programs prescribing the manners in which the grinding machine is to be operated in respective grinding modes. The computer, when receiving an automatic grinding instruction, serves to read out from the memory device the control parameters and one of the operational sequence programs necessary for the grinding control in a designated one of the grinding modes and then, to supply to the feed control device the feed control data after calculating the same from the read-out control parameters and the read-out one of the operational sequence programs.

Numerical controller for a grinding machine

A feed control apparatus wherein a servomotor control device responsive to feed pulses distributed from a numerical controller controls a d.c. servomotor to advance a grinding wheel carriage of a grinding machine through the rotation of a feed screw successsively at a speed-up feed rate, a rapid feed rate, a slow-down feed rate and a grinding feed rate. A detection device is provided, which outputs a velocity checking signal to an abnormality confirmation device when the carriage reaches a velocity checking point defined within a slow-down feed range. When confirming that the feed rate of the carriage has exceeded a reference feed rate lower than the rapid feed rate, the abnormality confirmation device applies a stop signal to an emergency stop control circuit in response to the velocity checking signal, so that the rotation of the servomotor is immediately discontinued.

Feed control apparatus for a machine tool carriage

A contact detecting apparatus for detecting the contact of a workpiece with a tool in a machine tool which comprises a coil mounted on the periphery of a spindle head and connected to an AC power source for generating an induced current in a looped secondary circuit including the workpiece, a work table, a machine body, a spindle head, a tool spindle and the tool, when the workpiece and the tool are moved relatively into contact with each other. Bypassing elements are included in the secondary circuit for bypassing an electric resistance in spindle bearings. A detector is connected between the AC power source and the coil for detecting a change in an electric signal caused by the contact between the workpiece and the tool.

In a pallet exchange apparatus for a machine tool, a rotary member carried to be rotatable in a horizontal plane mounts thereon a pallet support means which in turn supports a pallet unloaded from the machine tool and a pallet to be loaded into the machine tool. Each pallet is provided with an engaging hook. A transfer member is provided with a transfer hook engageable with the engaging hook to move the pallet to be loaded on the machine tool toward the machine tool. A fixed hook is provided to be engageable with the engaging hook. The rotary member is rotated to move the engaging hook of the pallet to be loaded on the machine tool into engagement with the transfer hook and to move the engaging hook of the pallet unloaded from the machine tool into engagement with the fixed hook.

Pallet exchange apparatus for machine tool

A cam grinding machine rotates a workpiece by using a servomotor which is capable of being rotated at a variable speed. A memory device stores data of rotational speeds of the workpiece corresponding to angular positions thereof in order to maintain the circumferential speed of the workpiece constant. A detecting device detects an angular position of the workpiece. A counter is responsive to the detecting device and reads out rotational speed data stored in the memory device in order to apply the same to the servomotor.

Cam grinding machine

A dressing apparatus for dressing a grinding wheel having straight and circular portions by a dressing tool which is moved by a pair of servomotors. A mode counter designates a mode of dressing operation on the straight and circular portions. A memory device stores numerical information to move the dressing tool along the circular portion. A gate circuit distributes clock pulses to both the servomotors in accordance with the content of the mode counter and the memory device, when the mode counter designates a dressing operation on the circular portion and distributes clock pulses to one of the servomotors in accordance with the content of the mode counter, when the mode counter designates a dressing operation on the straight portion.

Dressing apparatus for grinding wheel

A control apparatus for a machine tool having a tool support for supporting a tool for machining a workpiece movable relative to the workpiece is disclosed. The control apparatus includes pulse generating means for generating a train of pulse signals, a drive motor for moving the tool support relative to the workpiece in response to the pulse signals, first means for causing the drive motor to be actuated to move the tool support away from the workpiece, detecting means actuated when the tool support is moved into an original position and second means responsive to the actuation of the detecting means for causing the drive motor to be actuated to move the tool support toward the workpiece. The control apparatus further includes counter means responsive to the second means for counting the number of the pulse signals supplied to the drive motor, setting means for digitally setting a distance between the original position and a start position, and comparing means for comparing the contents of the counter means and the setting means and for generating a coincidence signal when the contents coincide to thereby stop the movement of the tool support.

Control apparatus for a machine tool

A feed control device is disclosed for controlling the feed speed of a tool relative to a workpiece to be machined. The device includes a load detector for generating an output signal in response to a load applied to the tool, a circuit responsive to the output signal generated by the load detector when the load is higher than a predetermined value for successively decreasing the feed speed until the load reaches the predetermined value, and a circuit responsive to the output signal generated by the load detector when the load is not more than the predetermined value for successively increasing the feed speed until the feed speed reaches a predetermined value.

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Aichi, Japan

Hideo Nishimura