Takeshi Ohuchi

Milling of wood and wood-based materials with a computerized numerically controlled router IV: Development of automatic measurement system for cutting edge profile of throw-away type straight bit

In industrial machining of timber, the method in which the operator visually inspects both wear and chippings of router bits after stopping the machine is generally adopted. However, many working hours are lost in this method and productivity suffers. Therefore, the development of a system that can automatically measure wear or chippings without stopping the machine is desirable. In this study, a laser measuring instrument was installed in a computerized numerically controlled (CNC) router, and an automatic measurement system for the cutting edge profile of throw-away-type straight bits with single-edged blades was developed. The main results are summarized as follows: (1) an automatic measurement system for the cutting edge profile of the bit was constructed; (2) this system was composed of a laser measuring instrument, a control personal computer (PC) for the CNC router, and a monitoring PC to control some devices and collect sampling data; (3) the system could measure the cutting edge profile of the bit without stopping the CNC router.

Milling of wood and wood-based materials with a computerized numerically controlled router V: development of adaptive control grooving system corresponding to progression of tool wear

A laser measuring instrument was installed in a computerized numerically controlled (CNC) router, and an automatic measurement system, which was developed in a previous study, was used to automatically measure the cutting edge profile of throw-away type straight bits without stopping the CNC router. In addition to the above-mentioned system, in this study, an adaptive control program based on experimental data was installed, and an adaptive control grooving system that improved machining accuracy and controlled the burr formation corresponding to the progression of tool wear under processing was developed. Verification experiments of this system were carried out. The main results obtained are summarized as follows: (1) the between-process method was adopted for this system, and three types of processing methods (type 1, 2, 3), which consisted of a combination of an up-milling surface and a down-milling surface after processing, were investigated; (2) from the results of verification experiments, type 2 and type 3 methods showed remarkable ability to improve the machining accuracy and control the burr formation; and (3) it was found that the system employing adaptive control processing corresponding to the progression of tool wear in grooving is very effective.

Cross-sectional cutting of bamboo with a pair of shearing blades for bamboo cube production

As a new use of bamboo, bamboo cubes may be useful as a shot-blast material for surface treatments. However, a suitable processing technique for bamboo cubes has not been established. In this study, to obtain basic knowledge regarding the processing technology for bamboo cubes, we installed shearing blades (upper and lower blades) in a universal testing machine to test cross-sectional shearing of bamboo. The shearing force generated in this shearing was composed of a vertical component (Fv), a forward component (Ff), and a side component (Fs). This shearing force (Fv, Ff, and Fs) and the machining accuracy were investigated under various processing conditions. The shearing force became larger as the thickness of bamboo increased. In particular, Fv showed a tendency to increase rapidly. Changes in the shear angle of the upper blade had a remarkable influence on Fv. This result suggests that the shearing force could be greatly decreased by adjusting the shear angle. The shearing force within bamboo of 3mm in thickness was almost unaffected by the blade angle, and the change of shearing force with increasing clearance was almost indiscernible. It was clearly demonstrated that a large number of bamboo cubes could be made when the shear angle was large and cross-sectional shearing was performed from the bark side. However, a consequence of a large shear angle is that burr area increases.