Method for controlling an electric cylinder and a control system for the electric cylinder

A method for controlling an electric cylinder in a device, wherein

• the device comprises
• an electric cylinder that moves a rod,
• a load detector attached to the rod that detects the load for pressurizing applied to a material to be pressed,
• a servo motor that drives the electric cylinder,
• a servo amplifier that is electrically connected to the servo motor and a servo controller and that controls the drive of the servo motor, wherein
• the servo controller is electrically connected to the load detector and the servo amplifier and outputs a speed control command to the servo amplifier so as to control the speed of the servo motor,
• the method comprising:
• a step S1 in which the servo controller
• sets the speed of the rod,
• sets a load for stopping that is a load set to less than or equal to a target load, and that is used for determining whether the rod should be stopped or whether the rod should be driven in the reverse direction to that for pressurizing so that the load for pressurizing does not exceed the target load, and
• provides a speed command signal from the servo controller to the servo amplifier based on the speed of the rod wherein the speed is input into the servo controller,
• a step S2 in which the servo amplifier provides current for driving a motor to the servo motor based on the speed command signal,
• a step S3 in which a servo motor is driven so as to drive the rod by the current for driving a motor,
• a step S4 in which a signal for a load for pressurizing, wherein the signal corresponds to the load for pressurizing detected by the load detector, is provided by the load detector to the servo controller,
• a step S5 in which the servo controller determines whether the load for pressurizing is bigger than or equal to the load for stopping based on the signal for the load for pressurizing,
• a step S6 in which when it is determined that the load for pressurizing is bigger than or equal to the load for stopping the servo controller stops providing the speed command signal to the servo amplifier, or provides a reverse signal that drives the rod in the reverse direction to that for pressurizing, and
• a step S7 in which based on the stopping of the speed command signal or based on the reverse signal the servo amplifier stops providing the current for driving a motor to the servo motor, or provides a current that drives the rod in the reverse direction to that for pressurizing.

A control system for an electric cylinder in a device, wherein

• the device comprises
• an electric cylinder that moves a rod,
• a load detector attached to the rod that detects the load for pressurizing applied to a material to be pressed,
• a servo motor that drives the electric cylinder,
• a position detector attached to the servo motor that is electrically connected to a servo amplifier, wherein
• the servo amplifier is electrically connected to the servo motor and a servo controller and controls the drive of the servo motor,
• the servo controller is electrically connected to the load detector and the servo amplifier and outputs a position control command to the servo amplifier so as to control the position of the servo motor, wherein
• the servo controller can set the speed of the rod and set a load for stopping that is a load set to less than or equal to a target load, and that is used so that the load for pressurizing does not exceed the target load, and
• further, the servo controller
• drives the rod based on the speed of the rod under the position control mode, and
• determines whether the load for pressurizing is bigger than or equal to the load for stopping, wherein
• if it determines that the load for pressurizing is bigger than or equal to the load for stopping, it provides a reverse command pulse signal that drives the rod in the reverse direction to that for pressurizing, and
• causes the number of stored pulses in the servo amplifier to decrease, to thereby stop the rod.

A system for controlling an electric cylinder in a device, wherein

• the device comprises
• an electric cylinder that moves a rod,
• a load detector attached to the rod that detects the load for pressurizing applied to a material to be pressed,
• a servo motor that drives the electric cylinder,
• a servo amplifier that is electrically connected to the servo motor and a servo controller and that controls the drive of the servo motor, wherein
• the servo controller is electrically connected to the load detector and the servo amplifier and outputs a speed control command to the servo amplifier so as to control the speed of the servo motor, wherein
• the servo controller can set
• the speed of the rod and set
• a load for stopping that is a load set to less than or equal to a target load, and that is used so as to determine whether the rod should be stopped or whether the rod should be driven in the reverse direction to that for pressurizing so that the load for pressurizing does not exceed the target load, and,
• further, the servo controller
• drives the rod in a speed-control mode based on the speed set for driving the rod,
• determines whether the load for pressurizing detected by the load detector is bigger than or equal to the load for stopping, and
• when it is determined that the load for pressurizing is bigger than or equal to the load for stopping the servo controller stops providing the speed command signal to the servo amplifier or provides a reverse signal that drives the rod in the reverse direction to that for pressurizing, and
• stops the rod or drives it in the reverse direction.