Papers by Author: Masayuki Okabe

Abstract: The safety system is defined in BS/EN764-7(2002) (Safety systems for unfired pressure equipment) European Standard which is equipped with pressure releasing means (e.g, safety valve, reliefe valve, rapture disk). However, this safety system is not adequately functional as a safety system because the pressure releasing means cannot ensure the security for safe-side failures or degradation characteristics. In view of this, this paper presentation an interlock system applicable to pneumatic driving systems based on the safety (confirmation) principle. This system in the Safety-related parts (system) without giving (harm) the effects of hazardous side of error to stop the run of the load by the power source shut off from the possibility of hazardous side of error, it is practical there is no contradiction in ISO12100, ISO13849 international standard. The interlock system discussion about the suitability of the safety system defined in BS/EN764-7. As a result, the consideration for ensuring the reliability in “Safety of the control” by BS/EN764-7 is requested by adopting the safety system of the interlock system.

Abstract: In this study, covering for the skill training centers in Japan, we performed surveillance study about the functions required for the general purpose milling machines for educational skill training. As a result, it was found that the function of recognizing machining state is desired for milling machines besides higher stiffness, higher accuracy, and the ease of chip treatment. Based on this fact, the general purpose vertical milling machine was developed for educational skill training. First, a beginner's work analysis was conducted and the functions which control the mishandling were developed. The operation mistake has decreased by this function. In addition, the cutting power inspection system was built by using high sensitive micro-wattmeter. And, the possibility of judgment of tool wear was found by inspecting the change of the wave profile in the wattmeter.

Abstract: The measuring method for thermal effects in NC machine tools was drawn-up as ISO 230-3 in 2001. After that, this international standard was introduced as JIS B 6193 in 2003. In connection with this, the measurement of thermal effects becomes achievable also not only in a machine tool builder but in a user side. Therefore, in this research, practical measurement and evaluation of thermal behavior in CNC lathe are performed from a user's viewpoint. Primarily in the experimental measurement, the spindle speed required for turning of the workpiece for a trial-production was given as a load pattern. Then the thermal displacement between cutting tool and workpiece was measured based on the above-mentioned standard and the evaluation result was reported. Secondarily, the consideration was done for the modification of the turning process of the most influential thermal effect. The thermal behavior by applying the modified load pattern was re-measured successively, and comparative evaluation was carried out. As a result, it was verified that an extensive reduction of the thermal effects was possible in the sensitive direction to the accuracy.