Cincinnati Milacron Inc.

John C Catanzaro

James E O'Bryan

Ronald M Sparer

David A Topmiller

A method and apparatus for verification of the linear position of a machine element driven by a motor is provided. The actual position of the element is detected and compared to an expected position. When the two positions differ from each other by more than a predetermined tolerance value for a predetermined amount of time, an error signal is generated which deactivates the motor and generates an alarm for the machine operator. Preferably, the linear position of the axis is detected by a transducer and the expected position is determined by detecting the rotary position of the motor through the use of a resolver, which is then converted to a linear equivalent through the use of the gearing ratio. The method and apparatus can detect faulty machine conditions and thereby prevent machine malfunction and/or machine damage. Preferably, the method and apparatus are used to verify the position of machine elements in an injection molding machine.

Method and apparatus for injection molding machine control

A method and apparatus for detecting an aberrant velocity of a motor used to drive an element in a plastics processing machine, such as an injection molding machine, for example. The velocity of the motor is detected by a first sensor and a machine parameter associated with the machine operation is provided. A velocity limit is determined based upon the machine parameter and an error signal is generated when the motor velocity exceeds the velocity limit by more than a predetermined tolerance value. Preferably, the machine parameter comprises the position of the element driven by the motor, which is sensed by a sensor, such as a linear displacement transducer. The velocity limit can be based upon this measured element position as well as data entered for the particular machine, such as a minimum element position, a maximum element position, and a maximum motor velocity, such that a desired motor operating envelope is defined. Also, the motor velocity command is preferably set equal to the velocity limit when it exceeds the limit. In another embodiment, the machine parameter comprises a motor velocity command for controlling the velocity of the motor. The velocity command is compared to the previous velocity command and the velocity limit is set equal to the velocity command when it exceeds the previous command.

Method and apparatus for detecting aberrant motor operation in a

A method for controlling clamping force on an injection molding machine by determining a toggle position at which the molds are in initial contact. That toggle position is determined as a function of a selected clamping force and a selected mold protect force and is effective to produce the desired clamping force when the toggle is fully extended.

Clamp force control

A method and apparatus for controlling the hydraulic pressure in an hydraulic clamping cylinder to correspond with a desired clamping force and to compensate for overshoot of the hydraulic pressure caused by time delays in operating the components in the hydraulic circuit. The control arrangement involves the sensing of the actual hydraulic pressure during the clamp force maintenance portion of a clamping cycle and comparing the actual pressure with a desired pressure to provide a correction signal to be utilized to control the operation of the hydraulic system during the next succeeding cycle so that the actual hydraulic pressure during the clamp maintenance portion of the clamping cycle during the next succeeding cycle results in a clamping force that is closer to the desired clamping force.

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Lebanon, OH, United States of America

John C Catanzaro