Shinsaku Hanasaki

Tool Wear of Coated Tools when Machining a High Nickel Alloy

Summary A high nickel alloy is well known as a difficult-to-machine material. A tool injury occurs severely in cutting of this material, especially in screw thread turning. Then, in this paper, four representative coated tools were used in turning of a high nickel alloy and the tool wear was investigated in detail. The main results obtained are as follows: In using coated tools, the flank groove wear is reduced and the tool life is decided by the boundary wear instead of the flank groove wear. An Al 2 O 3 coated tool is effective for the boundary wear. A TiC/Al 2 O 3 coated tool on the cemented carbide K10 has the least groove wear among the coated tools on the four kinds of cemented carbide.

Study on Manufacturing Technology of Middle and Small Sized Motors with Dividing Stator Cores. Development of a Brushless DC Motor Which Saves Energy with High Efficiency.

This paper reports the study on manufacturing technology of a brushless DC motor for saving energy with high efficiency. This motor has a joint-lapped core which is able to warp for the reverse freely. First, the joint-lapped core is formed with the high-speed press machine by cylindrical shape. In coil winding, the joint-lapped core is warped for the reverse by bending the joints and wound the coil under the condition of the alignment. After winding, the joint-lapped core is bent as a similar conventional circular stator. This manufacturing method brings the coil of the high density by using the thick magnet wire and the stator of a high degree of a right circle. As a result, it can be realized the efficiency of 96% of the motors in the compression machine for the air conditioner.

Study on Manufacturing Technology of Middle and Small Sized Motors with Dividing Stator Cores. Development of a Small and Powerful AC Servo Motor Used for Industrial Devices.

This paper reports the study on manufacturing technology of a small and powerful AC servo motor which used for industrial devices. This motor has a linear shaped core which is divided among teeth and connected by thin bridges. In coil winding the linear shaped core is wound by several nozzles. After winding, the linear shaped core is bent as a similar conventional circular stator. This manufacturing method brings the coil density to improvement of 30-40% and the optimization of the width of the slot opening. As a result, it can be realized that 40-60% of the motor capacity has decreased in comparison with before.

Electromechanical grinding at high work feed rate

Abstract Electromechanical grinding (EMG) of alloy tool steel and some other alloys was investigated at a higher work feed rate than that used in electrochemical grinding (ECG), with particular consideration of grinding mechanisms. An experimental analysis of grinding forces reduced by applied electrolytic action showed a slight decrease in mechanical removal and a severe loss of mechanical properties. Additional contributions of the electrolytic action to a reduction of grinding forces were clarified as the preferential dissolution of the hardened second phase and the suppression of the frictional component of grinding forces between material and wear flats. Theoretical consideration of the electrolytic action suggested an appropriate grinding mechanism on the basis of the experimental results.

TiN-Coated Twist Drill Drillable Deep Hole Under Continuous High Feed Rate

Non-coated normal drill generates long pitch helix type chip at the deeper drilling position than 7-8 times of drill diameter. TiN-coated normal drill has long tool life and lowers cutting resistance. However, it generates less long pitch helix type chip. TiN-coating decreases the long pitch helix type chip. Yet, it has been found that a TiN-coated twist drill which has narrow face of small rake angle shows good characteristics. The results are as follows : (1) The TiN-coated twist drill which has narrow face of 5-degree rake angle generates the long pitch helix type chip three times as much as the non-coated normal twist drill in 100 mm wet drilling. (2) And it generates the long pitch helix type chip which is connected with the conical helix type chip in 60 mm dry drilling. (3) The TiN-coated twist drill which has narrow face of 0 or 5-degree rake angle generates fragile chip that seems to be connected segment type chips with small area. These chips are exhausted out of the drilling hole very well. In case of these twist drills all chips are exhausted out of the drilling hole very well, the segment type chip occurs by fracture of this fragile chip after exhausting out of the drilling hole.

A Study of the Machining Accuracy of the Round-Off Truing Method: Effects of the Set-Up Angle for the Brake Truer

The round-off truing method for precision form grinding was proposed by the authors. The circular motion of a CNC grinding machine is utilized together with an abrasive stick or a brake truer. In previous studies, experiments and simulations were performed to clarify the mechanism and appropriateness of this method. Accurate truing for the precision form grinding, however, could not be realized through these studies. In this study, the mechanism of the round-off truing when there is a set-up angle between the truer spindle and the grinding-wheel spindle z has been clarified through vector analysis. The appropriateness of vector analysis and effect of z on the truing accuracy has been confirmed experimentally. The form error of the trued wheel surface shows the minimum value when z is in the range 10-20 degrees. Introduction A part of information technology, IT, is supported by optical devices such as aspherical lenses and mirrors, which require the super-precession machining technology in production. In order to generate non-axisymmetric aspherical lenses and their dies, precision form grinding using a grinding wheel with round-off (toroidal shape) is necessary [1-2]. In this case, the form error of the grinding wheel directly affects the form accuracy of the generated shape. In the previous studies [3-5], the authors proposed a very simple round-off-truing method utilizing the circular motion of a CNC grinding machine. In this method, a brake truer (or an abrasive stick) is set on the machine table and a grinding wheel is moved around the truing wheel along the circular path as shown in Figure 1. Effects of the circular-motion radius, G, thickness of the truing wheel and the grinding wheel, Ts, Tg, on the generated curvature radius of the grinding-wheel surface, Rg2, and error factors introduced in the truing process were examined by computer simulations and experiments [3-7]. Through these studies following results were obtained. Regardless of size and wear ratio of a truing wheel, , Rg2 settles into the value that can be calculated by ). 1 ( 1 1 + = Tg Ts G Rg (1) A brake truer has the capability of efficient round-off truing in comparison with an abrasive stick. Truing wheel Ts Grinding wheel Tg Rs2 Brake truer Rg2 G Fig.1 Setup for the round-off truing Key Engineering Materials Online: 2003-04-15 ISSN: 1662-9795, Vols. 238-239, pp 321-326 doi:10.4028/www.scientific.net/KEM.238-239.321

Moldability of Long Glass Fiber Mat Reinforced Polypropylene Resin Sheet to a Cupped Part.

Long glass fiber mat reinforced polypropylene resin sheet is one type of stampable sheets. The stampable sheet is easily formed into a part, but it has some problems in the processing. So, in this report, the effects of molding conditions on the moldability were investigated. That is to say, the effect of the heating temperature, the heating time, the mold temperature and the charge pattern on the strength and the surface roughness were investigated in details, when the cupped parts were molded. The main results obtained are as follows: 1) The most suitable heating conditions of the stampable sheet blank are 230°C and 5 min. 2) The part made from 4 pieces of ply has the highest strength. 3) In the case of the mold temperature below 100°C, the higher the mold temperature is, the better the surface rouhness of part is. 4) The part under the mold temperature 150°C had the highest strength.

Effect of surface-pretreatment on adhesive strength of hard chromium plating.

Testing the adhesion between chromium plating and the base metal involves many difficulties, and the conventional test is too inaccurate to permit analysis of adhesion. For this reason an improved adhesion test, based on the drawing method developed by R. A. F. Hammond et al., was used to measure the strength of adhesion of chromium plating to the base metal. As the hydrogen overvoltage on the base metal surface to be plated seems to have a great effect on the mechanism of electrodeposition in chromium plating, it was measured to clarify the chemical characteristics of the surfaces, and the adhesion mechanism was considered.It is considered that the condition of the base metal surface to be plated influences the structure of the metal deposited at the first stage of the electrodeposition, and that the strength of adhesion of the plating to the base metal varies. If the base metal surface is etched by counterelectrolysis in the chromium plating bath just before plating, the base metal surface becomes favorable for plating. This etching process causes stronger adhesion of chromium plating to the base metal.