So what exactly are CT effects?
Overview of the Line
This case example involves onboard assembly and test lines with four steps. The cycle time of Step 3, which was taking the longest among them, was reduced.
- Number of air cylinders = 8 units
- Unit 1 - Moves the work table
- Unit 2 - Press-fitts the connector
- Unit 3 - Electric continuity test
- Units 4, 5, 6 - Stamping
- Unit 7 - Connection of wires for inspection
- Unit 8 - Stops the work table at the midpoint
- Product types supported = 10 types (25 types can be supported with 3 lines.)
- Cycle time = 14.0 seconds
Overview of the System
It is a simple semi-automatic system that conducts a performance test of onboard sensors. When the operator sets the work part and presses the start switch, the work table moves forward toward the back of the system. Once steps 1, press-fitting of the connector (assembly): 2, electrical continuity test: and 3, stamping (PASS stamp) are completed, the table comes back to the forward position.
Significant Improvement of Production Efficiency through Motorization
With the air cylinder system, the work table could not be operated faster because it would have increased the shock upon stopping. With the ROBO Cylinder system, on the other hand, the maximum speed can be increased because the actuator stops without generating shock. In addition, the ROBO Cylinder system starts quicker than the air cylinder system, which enabled significant reduction of the cycle time.
With the air cylinder system, an automatic switch was used to determine whether the work part had been pressed to the specified position, which made the operation unstable and required 4 seconds for the press-fitting action to ensure quality. With the ROBO Cylinder system, on the other hand, push-motion operation can be performed using the zone function and consequently the press-fitting time was successfully reduced by 2 seconds.
Number of lines and operators required to produce
5,000 pieces in one 7.5-hour day (27,000 sec.)
3-year total: $261,200
As illustrated above, the reduction of cycle time through the motorization of the air cylinder system yielded a profit of $116,800 for the first year, and $72,200 for the second and subsequent years, resulting in a 3-year total of $261,200.
* Based on case study in IAI Japan. * Exchange Rate: 1 (USD) = 100 (Japanese Yen)