Search Results

Through CAE (Computer Aided Engineering) analysis, a method in verifying the reliability of wire harnesses has been developed. The relative displacement of the engine causes the battery cable to bend repeatedly; this may result in cable breakage. By investigating the breakage mechanism of battery cables, we have found a correlation between the strain change and cable breakage. Furthermore, the dynamic profile through CAE analysis has been established, and it is also possible to calculate its strain. Using this method, we can limit the amount of actual tests and predict the bending life of battery cables.

Sumitomo Electric Industries (SEI), which has been producing its first generation ABS since 1987, has continued its R & D efforts to develop a second generation ABS better suited to a wider range of vehicles. A Compact ABS has been successfully developed, which has realized the smallest and lightest 3/4-channel hydraulic unit known to the authors, taking full advantage of the newly developed flow control valve.

The high reliability silicon nitride sintered body and the mirror finish grinding machining technique have been developed, which improved fuel efficiency by reducing weight and friction loss of the valve systems. This ceramics, consists of finer grains (mean grain size:1-3μm) has high strength (σ 3b=1600MPa) and high Weibull modulus (m>20). In the case of motoring test by using this ceramics as the cam follower of the valve systems, it has a durability of more than 10,000rpm., which is approx. 30% higher than that of conventional silicone nitride, against the impact load to which the cam followers were subjected at occurrence of valve bouncing.

Fiber-optic data links have been developed for use in vehicle navigation systems, especially for the communication of CD data. The links consist of transmitters, receivers, and cable assemblies. The transmitters, which include only LEDs, must have driver circuits on their exteriors. In the receiver section, a PD, an amplifier, and a TTL compatible comparator are all integrated into the custom designed IC which is hermetically sealed into an originally developed metal package. Small optical connectors and heat-resistant plastic fiber cords with sufficient reliability and good operability for automotive uses have also been developed.

The joining process of silicon nitride (S13N4) turbine rotor and steel metal shaft was investigated. The process consists of brazing procedures with multi-layer metallizing and complementary steps involving shrink fitting and non-destructive tests. In the course of the brazing steps, preliminary investigations using small specimens were conducted on the formation of a highly strengthened interface at high temperature and thermal stress reduction, and superior high temperature strength and heat cycle resistance were obtained. Rotary tests at high temperature were successfully completed using the rotor joined by this process.

Sumitomo Electric Industries (SEI) has developed the “Variable Flow Valve” (= VFV), which is small, low cost, and suitable for the precise control of hydraulic systems. With the VFV, the hydraulic flow can be regulated continuously by controlling the electric current. The VFV is able to regulate the flow of low viscosity fluid: under high pressure; in the low flow range; smoothly, quietly, and with quick response. We are confident that the performance and reliability of the VFV allow it to be applied to vehicle brake systems, and also hopes to find applications to other hydraulic systems.

We developed a remote control unit (Hereinafter referred to as the controller) employing mainly an eight-directional joystick with push-button function. And it has good operational feeling. As previous joysticks generated operator feeling via springs, so the click sensation could not be felt. We thought that a good click feeling can be obtained by applying rubber contacts to the switch element of the joystick. Additionally, in order to include the push-button functions, we supported the operant unit with biaxial bearing and employed a sliding-knob structure penetrating this operant unit. Also in order to obtain a uniform operator feeling for all eight directions, we applied eight rubber contacts and gave the switches eight contacts. In order to restrain the rise in IC costs with the increase to eight contacts, we introduced an eight-contact four- output switch matrix and a one-contact three-electrode pattern.

An internal gear-type pump has advantages compared with an external involute gear-type pump, for example, higher mechanical or volumetric efficiency, considerable reduction of weight and dimension in the oil-pump system[1]. This paper presents characteristics of the internal gear type rotors with a modified trochoidal profile in the oil-pump system, and new P/M(Powder Metallurgy) aluminum alloys which satisfy required wear properties as the lubrication oil-pump rotors. Also, the advantage of high volumetric efficiency and discharge performance and excellent properties of the oil-pump rotor with a modified trochoid profile were combined with a R/S (Rapidly Solidified) aluminum alloy in the scavenging pump for racing car engine. Good results without wear or damage after an actual race are also reported.

Recently, powder metal parts have been used in a lot of automobiles. One typical powder metal part is a helical gear. Compacting helical gears is much different from conventional compacting, because a part of the tool rotates on its own axis. The important points are as follows: (1) how to guide the upper punch into a die smoothly and to fit in it, (2) how to rotate the die/punch smoothly in order that the part of gear trains may not be broken by twisting stress during pressing process and (3) how to prevent green compacts from having crack/lamination. The larger the helix angle, the more difficult its compacting. The compacting of complicated shapes such as helical gears with an irregular shape or another helical gear is more difficult. Powder metal helical gears are produced because powder metal is suitable for mass production at low cost. Most powder metal helical gears are simple shapes such as helical gears only outside or inside.

Oil-pump rotors with a trochoidal tooth shape have many advantages compared with others, but the trochoidal tooth shape has not been sufficiently analyzed theoretically. So it is very difficult for the pump designer to decide the specifications for the trochoidal tooth shape, and it is also difficult for the supplier to meet the pump designer's requirements. We have been conducting theoretical analyses of trochoidal gears for several years, and have developed a system for designing the tooth shape. We can rapidly design the tooth shape, which meets the requirements of the pump designer, and develop the market for trochoidal gears by using this system. This paper shows the outline of the theoretical analysis, the outline of oil-pump rotors attached to crank shafts in automobiles as an example of the development of trochoidal gears, and some test results.

Recently, SiCr clean steel wire for springs on automotive engine valves has been developed. This report describes the characteristics of valve springs subjected to a new manufacturing process using SiCr clean steel wire. The process developed by the authors is as follows: First, form a helical spring with SiCr clean steel wire. Next, quench using the distortion preventing technic --Marquenching--. Temper at a temperature lower than the conventional temperature. Shot peen to the surface layer of the spring. And lastly, polish electrolytically to remove micro surface defects formed through shot peening. Using this new manufacturing process, a valve spring with high fatigue resistance can be produced. At the test stress of 588MPa(τm)±490MPa (τa), the number of cycles to fracture was above 100 million, while the number of cycles to fracture was 4 million using the conventional process with the SiCr clean steel which has the best fatigue resistance for commercial use.

The first SUMITOMO ELECTRONIC ANTILOCK SYSTEM (ALS), a 4-Sensor 3-Channel System for sophisticated FWD vehicles, has been in production since 1987. Further developments have lead to systems suitable for 4W vehicles and compact cars, showing increased control quality and reduced size, weight and production cost. Reliability, one of the major targets in the development of the First system's Electronic Control Unit (ECU) since 1982, was successfully achieved. Recent work has been geared toward reducing the size and production cost of ECU hardware, whilst maintaining the system's reliability. This paper describes the basic design of the current 1987 ECU and further details developments of the hardware.

ABS sensor rings for automotive use are becoming smaller and thinner because of the demand for low cost and light weight. Such small thin parts are easier to break as they must withstand the same severe conditions as larger heavier parts. Superior elongation properties, after corrosion testing, are necessary for avoiding breakage and to obtain superior corrosion resistance. We have, therefore, developed such high performance P/M stainless steel with superior elongation and corrosion resistance. Conventional stainless steel has uniform pores on its inner surface which makes allows water penetration thus making corrosion worse and decreasing elongation. It is possible to increase corrosion resistance by changing pore structure (e.g. decrease continual pores) through the addition of special alloys that accelerate the sintering process.