By the microinterferometers employing fringes of constant thickness, it is found that the angle of incidence to the reference mirror and the specimen is normal or very nearly so. Therefore, the difference of height corresponding to the fringe spacing obtained is λ/2. (λ is the wave length of the monochromatic light employed.)
In this method, the fringes are obtained by employing the oblique incidence to the reference mirror and the specimen, and are observed by a microscope in the light of the regular reflection. The fringe spacing is accepted as equivalent to λ/2 cos θ by the simple computation which is confirmed by experiment (θ is the angle of the incidence or the reflection. 0°<θ<90°)
Since the fringe spacing is 1/cosθ times as large as λ/2, the measurement of the surfaces rougher than those which can be measured by normal incidence type is possible.

View full abstract

From the experiments on the cutting of 0.4% carbon steel, in which cutting speed, rake angle, feed and workpiece temperature (hot machining) were varied, following relations were found :
ω≡φ+β-α=f(α) … (1)
m=k_mt₁sinω/sinφcosβ, k_m_??_2.0… (2).
Notations are shown in Fig. 1.
Applying the total reflection method to the cutting of lead by a glass prism, it was found that the ratio of the true tool-chip contact area to the apparent contact area, k_c, was nearly equal to 1.
Considering the balance of force and equation (2), the following was obtained.
k_ck_nτ_c/τ_s=sin2β/sin2ω, k_ck_m_??_2.0… (3)
where, τ_c and τ_s are the shear flow stress of the work material at tool face and shear plane. Then, τ_c and τ_s, which should be determined by the temperature, the strain and the strain rate at both zones, are known, β and φ can be determined from the equation (1) and (3).

View full abstract

In the previous paper the characteristics of the single pneumatic element was described.
This paper presents the results of the experimental investigation on the characteristics of the hydraulic element and on those of the control system.
The results of the frequency response experiments are shown by the Bode diagrams and then the stability of this control system is discussed.
Finally the errors of the actual cutting condition by this method are considered.

View full abstract

The accuracy of precision parts of phosphor bronze wire sometimes decreases due to aging, and this is considered owing to the residual stress of the wire induced by drawing and forming. I tried to find the heating temperature to relieve the residual stress without lowering the elastic limit by checking the residual stress, elastic limit, micro-hardness and microstructure of 0.7 mmo phosphor bronze wire heated at various temperatures ranging from 100° to 500°C.
Strictly speaking, I could not find the temperature at which the residual stress of the wire can be relieved without lowering the elastic limit. But the heating at the temperature ranging from 230° to 300°C is effective for practical purpose, if slight lowering of elastic limit is allowed.

View full abstract

The important role that coolants play in metal cutting is to reduce the tool-face temperature and increase the tool life. The procedure in computing of tool-face temperature under cooling is guided by equating the mean temperature along tool-chip interface from chip side and that from tool side. As reported in the previous papers, the former is obtained from the analytical study that is the application of the difference method for the flow of heat in chip cooling, and the latter is lead from the electrical study treating the cooled tool as a electrolytic tank. The relative importance of several variables, especially the cooling power and supplying device of coolant, influencing tool-face temperature is discussed. This shows that, even if new coolant or supplying method may be contrived, so far as heat transfer coefficients are not widely different from those of the present, they will not be able to meet our requirement to reduce tool-face temperature. But, it is effective means to cool the work-piece enough and strongly and to lower the temperature of coolant itself.

View full abstract