YANMAR AGRIBUSINESS CO., LTD. - Yanmar's Strengths

Torque Control System

Torque wrenches are used on products such as combine harvesters and tractors to ensure that all bolts are tightly fastened on the undercarriage and other parts crucial to product quality. With the torque control system, the bolts to be fastened on each part undergoing assembly are recorded and displayed on a computer. As the torque wrench tightens each bolt, it sends a signal to the computer to confirm the fastening of the bolt. This ensures that no bolts are missed before a part is sent to the next process on the production line.
The Okayama Plant is currently verifying this system's effectiveness.

Work Flow of Torque Control System

The torque check points (sections of a part where bolts occur) are recorded for each part undergoing assembly. These check points are indicated as they come up during the production process.
There are currently about 70 check points that are confirmed using the torque control system.

Large-Scale Undercarriage Parts Assembly Line

Because a flaw in the undercarriage of a large combine can be a matter of life and death, the assembly section of the Okayama Plant uses a torque control system to prevent improperly fastened bolts. The torque control system is located next to each assembly location in the plant, where it indicates the check points on the part and determines whether these are fastened with the proper torque.

To prevent improperly fastened nuts and bolts on crucial sections of parts undergoing assembly, a torque check is conducted on sections indicated by the computer. Items are sent to the next process of production only after they are verified by the system.

The torque wrench has a transmitter that sends a signal to the computer after each section is checked. The computer sends this information to a host computer for permanent storage. Plans are underway to further improve quality by gradually installing torque control systems, starting with production processes that are most important to safety.

Crawler Assembly

The torque control system has proved effective for crawler assembly as well. It is also used to prevent errors in assembly order.

Computer Check System

Large tractors, combine harvesters, and rice transplanters contain many controllers, sensors, and actuators. Quality control of these parts is done manually, making them susceptible to human error or oversight. With the computer check system, the product being manufactured is connected to the computer which carries out an electronic inspection.

Because the computer conducts inspections automatically and assists personnel doing them manually, inspections can be conducted with consistently high quality and in the same time frame no matter who is in charge.

Automatic Transport Vehicle

Within each unit in the factory, this vehicle efficiently transports semi-finished items, parts, and components between assembly lines, painting lines, and other workplaces. Each vehicle moves automatically along a fixed track to save energy while ensuring safety.