1.AGV and the cell production
Since our engines (ENG) and transaxles (T/A) are the products for mass market, we had been assembling them by the conveyer lines. However, the variation of the products increased as the history was piled up, and the losses due to combined production in a same line has been actualized.
Then, diverse models with large man-hour difference and low-volume production model were separated from the mass production model, and the mass production model was moved to a line with high productivity. At the same time, we pursued a profitable, non-mass production line no way inferior to the mass production line.
As a result, we were able to construct the cell-production line with simple Auto Guided Vehicle (AGV) based on below concepts. The non-mass production line must be
- ・no losses related to the structure of the line, even the production models are not consistent:
- ・flexible about volume changes:
- ・easy to handle for everyone and human friendly:
- ・low-priced and flexible
We hereto introduce it.
2.What is the assembly line by simple AGV?
Set up a cell production
(self contained)assembly line.
Since the non-mass production line has models with big man-hour difference and volume change,it generally enjoys advantages of the cell production system. AGV can minimize disadvantages of the cell production system. Therefore, we adopted a circuit method that enhances pace management and self operation by using AGV.
(bench production)
Conveyer Method (one process a person) |
Cellular manufacturing | ||||
Division meth (partial round) |
round method (so called “Rabbitchasing”in Japanese) |
||||
Loss |
Organization efficiency |
▲ |
○ | ◎ | ◎ |
Part and tool handling |
○ | ○ | ○ | ▲ | |
Model arrangements | ▲ | ▲ | ○ | ○ | |
Work skill | ○ | ○ | ▲ | ▲ | |
Helping | ○ | ○ | ▲ | ▲ | |
Easiness of automation | ○ | ○ | ○ | ▲ | |
Installation cost (I・C) | ○ | ○ | ○ | ▲ | |
Flexibility | ▲ | ○ | ◎ | ◎ | |
Flexibility for volume change | ▲ | ○ | ◎ | ◎ | |
Optimal production in each factor | Production volume | large ←←←←←←← small | |||
Number of models | few →→→→→→→ many | ||||
net man-hour | many ←←←←←←← few |
Multifunctional AGV is not necessary, as long as the automatic machine has the stop position accuracy. Therefore a low-priced, simple typed AGV around 500,000 yen with the basic specification was adopted this time.
3.A case with non-mass production assembly line
1Launching of T/A non-mass production line ・・・ The AGV is used from Parts collection to finish test throughout the processes.
When the line of a new unit was set up, even picking (part collection) process of the gear parts (13 parts) and test process that falls on the process before and after assembly were incorporated in the line. Then a one-person conclusion by AGV was advanced, and it was able to be a line saved labor, processed one by one.
(From the layout based on the function to the layout based on the products. )
2)Launching of ENG non-mass production line ・・・ Introduction of defect-free (Poka-yoke) line regulated by AGV
The target product is with many kinds, small volume, large man-hour and variety of processes. In such case, a defect-free system is absolutely necessary from the point of view of the quality assurance. So, a regulated, not human-attention typed defect-free was adopted for the new line.
defect-free management BOX | Start restriction sensor |
3)Launching of CVT assembly line ・・・connection with automatic machine by making detachable of the assembly jig
4.Improvement using AGV for the rest of assembly
1)Transportation improvement at T/A mass production line
By using AGV as a transporter between processes that means the basic function of AGV, the sub works in the mass production line of T/A, were moved among the processes to balance the organization of job and reduce the loss of organization.
2)Gear processing (processing -- heat-treatment -- processing)
3)Foundry (LPC casting- cooling - finishing)
In the foundry of a bad environment, the work is transported between casting process, cooling process and finishing process. To cover the condition that the work is very hot and core sands are scattered, the AGVs with sweeping function were adopted.
5.Introduction of AGV used this time
6.Aiming at the improvement for tomorrow
・Working environment that doesn't give worker stress
・The stock in the line is small due to the high productive efficiency like average mass production, even it is non-mass production.
・It doesn't dig into one's purse.The improvement is advanced aiming at such a line now.