Sanyo Seisakusho Co. Ltd.

Technology Development Case Studies

Manufacturing Processes

Part	Usage	Example
Separating Plate	4-Wheeled vehicles	Switched to producing with a press instead of a grinder.
Clutch Lifter	2-Wheeled vehicles	Switched from using clips (clips and pins) to press and molding.
Tappet Shim	2-Wheeled vehicles	Switched from using cutting techniques to pressing
Sprocket	2-Wheeled vehicles	Switched from using cutting techniques to pressing
Locker Arm	2-Wheeled vehicles	Switched from producing with heat tempering and cutting to using presses.
Valve Spring Retainer	Machinery	Switched from producing with cold tempering and cutting to using presses.

Introducing New Machinery and Processes

Bearing pressure apparatus

We have developed apparatus for a press that automatically measures the pressure-free smoothness of rotation and load-bearing qualities of the ball bearings used in the bearing holders in electronic throttle valve axles.

In order to keep costs down, we also harnessed an innovative approach that allows us to guarantee the pressure-free load-bearing and rotation figures at the time of pressing.

Chamfer Cutter with Built-in Guide

We have developed a special cutter with a built-in guide that has a longer working life and can guarantee a smooth surface even when chamfering an SPCC t1.0 pressed item 0.8 deep at a 94 degree angle.

This is achieved by first forcing a guide bush that is slightly smaller than the intended lower diameter of the hole into the underside of the press-formed part. Then, before chamfering is begun, the cutter guiding mechanism is fitted into the guide hole created by the guide bush, thus ensuring that any vibration caused by the cutting process is reduced to zero. As a result, we have seen a jump in the working life of the cutter as well as an improvement in the surface quality of the cut surface.

Rounded surface pressure shaping process using load cells

We are able to press-form rounded surfaces within a tolerance of R0.2±0.02 by using load cells to monitor the weight applied with each application of the press.

There is always going to be movement of the metal sheet used in press forming and it is impossible to make fine adjustments with the normal method of regulating the load through the use of hydraulic fluid pressure adjustments. However, by employing load cells it has now become possible to make incredibly accurate rounded finishes.

Bridge Press

A high-precision die-cut surface is vital for the sprockets and other parts driving the camshafts of two-wheeled vehicles, and in order to achieve this it is necessary to have both a high-precision die and a high-accuracy, immensely rigid press. However, since using a high-precision, highly-rigid press would result in a huge cost increase, we instead focused on how we could adapt a low-cost press to achieve high levels of precision and rigidity. We teamed up with a press maker to analyze the weaknesses of the basic press design and simulated various solutions to improve it at the lowest possible cost. The result of this development work is the bridge press. We now employ 6 bridge presses, allowing us to produce excellent high-precision parts for our customers.

In addition, as a result of our research into the flexing of slides and bolsters that is a particular characteristic of double-conrod presses, we have been able to implement methods to narrow the amount of pitch and reduce flexing in the conrods to produce a press that is even more rigid.

Laser marking apparatus

In the past, workers had to manually adjust the tappet clearance for the 16 inlet and outlet valves used in the engines of medium and large motorbikes. However, now it has become possible to automate this process through the insertion of a part called a tappet shim. Unfortunately, as a result of this development it also became impossible to keep track of the production process. The reason is that tappet shims are 0.025mm thick and come in 94 different types, and it is impossible to imprint any sort of identifying symbols on the surface of the tappet shims themselves. To solve this problem, we developed an automated quality control machine that uses both a YAG laser to mark each one with individual codes and two linear guages to automatically measure the thickness of each part and decide whether to accept or reject it.