Automatic Sorting System
Changing the speed during movement to reduce the cycle time by 20%
System Overview
1. Explanation of Process
Cardboard boxes containing CDs travel on a conveyor. There are five different types of cardboard boxes, and each type contains different CDs. Boxes are sorted by type and transferred onto five product conveyors.
2. Explanation of Operation
- A cardboard box moves on the transfer conveyor and passes the product identification unit. The unit reads the bar code on the cardboard box and identifies the type of CDs packed in it.
- As the cardboard box arrives in front of the applicable conveyor, it is pushed by the sorting air cylinder onto the conveyor.
Problems Experienced While Using the Air Cylinder
The cycle time can be shortened by increasing the speed of the sorting air cylinder.
However, a higher speed may cause the sorting push-out plate to bump the cardboard box and damage the products inside.
This is why the company couldn’t shorten the cycle time by increasing the air cylinder speed.
When they were using an air cylinder for their system, the cycle time was 5 seconds.
Improvements Achieved by the ROBO Cylinder
1. Changing the speed during movement to reduce the cycle time
The ROBO Cylinder lets you set the speed, acceleration, and deceleration separately.
Using the ROBO Cylinder, the company was able to shorten the cycle time by 1 second by setting a low speed in the range where the sorting push-out plate contacts a cardboard box and setting a high speed in the range where the plate subsequently performs push-out operation.
Effect of shorter cycle time
Cycle time |
|
Air cylinder:5.0 seconds |
ROBO Cylinder:4.0 seconds |
Line operating hours a day |
|
Air cylinder:11.5 hours |
ROBO Cylinder:9.2 hours |
Line operating hours a year |
|
Air cylinder:2,875 hours |
ROBO Cylinder:2,300 hours |
2. No more damaged product
On checking the returned boxes, the company found damaged CD cases. The investigation of the damage cause revealed that the air cylinder of the automatic sorting system was bumping the cardboard boxes upon contact.
After changing the Air Cylinder to the ROBO Cylinder, bumping stopped, and there are no more reports of damaged product.
Process Improvement with the Seven Benefits of the ROBO Cylinder
- With the ROBO Cylinder, the speed, acceleration, and deceleration can be set for each position. A stable movement is possible by setting the best speed, acceleration, and deceleration.
- You can also change the speed during movement.
Cost Cutting Effect
1. Conditions
One operator oversees three lines.
Production volume |
8,300 boxes |
Labor cost |
$18*/hour |
Annual operating days |
250 days |
Exterior View after Improvement (ROBO Cylinder adopted)
2. Comparison of Air Cylinder and ROBO Cylinder
| Item | System using air cylinder | System using ROBO Cylinder | |
| Cycle time | 5.0 seconds | 4.0 seconds | |
| Line operating hours (day) | 11.5 hours/day Cycle time 5.0 seconds x 8,300 boxes = 11.5 hours |
9.2 hours/day Cycle time 4.0 seconds x 8,300 boxes = 9.2 hours |
|
| Labor cost (annual) | $17,250* 11.5 hours/day x $6*/hour x 250 days/year = $17,250* |
$13,800* 9.2 hours/day x $6*/hour x 250 days/year = $13,800* |
|
Note: One operator oversees three lines, so the labor cost per hour is calculated as $18* / 3 lines = $6*.
3. Cost Cutting Effect
| Air cylinder | ROBO Cylinder | ||
| Labor Cost (annual) | $55,800* – | $38,250* = | $17,550* |
| Difference = | $17,550* |
Result
By adopting the ROBO Cylinder, the cycle time was reduced
by 20% , and annual cost savings of $3,450* was
achieved.
* Exchange Rate: 1(USD) = 100(Japanese Yen)