Molding Operations - Tending Injection Molding Machines

This page demonstrates an application regarding tending an injection molding machines and provides detailed information about the task development.

Contents

• Contents
• Application – Video
• Scenario
• Gripper Information
• Task Overview
• Create and Set Up Signals and Variables
• Key Task Elements

Application – Video

Scenario

• Re-register landmarks during initialize procedure.
• Wait for input from part presents sensor on right or left conveyor.
  • If both are present, pick from the right conveyor first.
• Pick part and move to a pneumatic cutter.
• Trigger cutter to remove excess material from part.
• Move part to final place location.
  • Final place location is two stacks of 40.
  • Contact place is used for the stacks.
• While placing in the stack locations, command the pneumatic cutter to rotate and drop the scrap into a bin.
• After both stacks are full, move to a wait location and wait for the operator to restart the sequence using a force push.

Gripper Information

Note: EOAT was designed and built by the end user with off the shelf parts from 3rd party suppliers and minimal machine work and build time.

• Tool Center Point = (X)-63.5mm, (Y)0mm, (Z)114mm
• Mass = 1769g
• COM = (X)-30mm, (Y)0mm, (Z)50.8mm

Task Overview

Create and Set Up Signals and Variables

Signals

Four different signals are required for this application:

All four signals are configured with the default value set to false. See the image below for an example of the configuration.

Variables

Three different variables are used in this task:

The image below shows the final configuration of one of the variables.

Key Task Elements

Task Work Flow

Pick Sequence

Notes:

• A Wait Until node is used to prevent to robot from moving to a pick location until the left or right conveyor has a part available.
• A Priority node and Do If nodes are used to force the robot to the right conveyor if both parts are available and also ensure the robot does not perform both pick sequences at once.

Cut Sequence

Notes:

• Similar to the pick sequence, a Priority node is used to determine which of 2 sequences to follow.
  • The Pick Option variable controls which sequence will run.
  • Different sequences are required because the excess material is a different size depending on which machine produces the part.

Place Sequence

Notes:

• Contact detection is used to place the parts in stacks with only one move to node.
• The Place Count variable is used to determine if the parts should be placed in stack one or two based on current count.
  • Based on the condition shown in the Do If node, it can be seen that the parts are placed in stacks of 40.

Stacks Full Sequence

Notes:

• This sequence will only run if the Place Count has reach 80 meaning both stacks are full.
• This sequence moves the arm to a safe position and waits for a force push by the operator to continue.
• After the force push is received, the sequence resets the Place Count to 0 and begins moving back to home.

Empty Cut Sequence

Notes:

• This sequence runs in parallel to the robot sequence and is controlled by the Empty Gate Cut variable.
• When the variable is set to 1 in the primary task, the sequence starts.
• Output signals are used to command the pneumatic cutter to rotate, open, and rotate back.
• The Empty Gate Cut variable is then reset.