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Technical Paper

Analysis of Milling Mechanism by Ball End-Mill and Development of High Speed Die-Sinking Method

1988-11-01
881742
Various dies have been used for producing many internal and external parts of an automobile. This paper describes the method of ‘High Speed Die-sinking’ that is one of the key technologies for die-making. We analyzed the milling mechanism of a typical Ball End-Mill used for die-sinking and performed cutting tests. As a result, we have achieved high speed and fine quality die-sinking technology. Its feed speed is about four or five times as fast as before, and the irregularity of the milled surface is under one-fifth as compared with previous level. In addition, we will propose the new method for estimating finishing performance by ball end-mill.
Technical Paper

Computation of Vehicle Center of Gravity

1988-11-01
881741
A simplified method has been developed for determining the vertical center-of-gravity using selected vehicle dimensions and weights. The equations used to compute both horizontal and vertical C.G.s are presented along with a computer program written in BASIC. Results for selected vehicles are compared with C.G.s determined from more complex tests. A technique is presented showing how dimensions can be obtained from a simple photograph of the vehicle. An empirical formula for estimating the vertical C.G. is presented.
Technical Paper

Discharge Regulator of Painting Robot and Establishment of CAD Teaching System

1988-11-01
881747
Abstract The current spray painting system is hardly considered that the thickness is controlled enough, because the temperature greatly influence on the viscosity of paint. We noticed the problem and detected the temperature at a nozzle of a spray unit. We tried that the paint flow is controlled to get stable thickness more accurately by the temperature feedback system. We also tried to develop the new programming method of robots. This new offline programming system provided us an ideal positions and orientations of the spray gun mounted on a robot wrist, after several simulation in the CAD system. We checked and debugged the office taught date with a trial robot in a trial area, and then loaded down with the date to a target robot. We eventually provided a better production technology with the paintflow control system together with the new CAD based offline programming system.
Technical Paper

Nonlinear Analysis Theory of Single Leaf Steel Springs

1988-11-01
881744
The analytical methods for single leaf steel springs should at least include two areas: (1) allowance for any curved or tapered shape, and (2) technologies to precisely predict the geometrical configuration due to large deflection. The last item is an outstanding consideration in automotive application because of the parts alignment requirement. In this paper, a practical analytical method is presented to achieve the goals mentioned above. Basically, the. flexibility method of finite element was employed in the solution technique. In the spring application, this approach can save computer time because of the elimination of matrix inversion in the internal computation. An integration form of the flexibility matrix for each element was given in this paper to allow for a tapered spring shape. This integration-formed flexibility matrix can be approximately evaluated by the Gaussian Quadrature Formula.
Technical Paper

Computational Study on Flow through a Torque Converter

1988-11-01
881746
The computation of the Navier-Stokes equations through the three torque converter components (i.e., the pump, the turbine and the stator) is shown. A third-order-upwind scheme is used in the computation. The flow in each component is first calculated individually. Then, the calculation results for each outlet condition are used as the inlet condition of the next component, and the flow in each component is calculated again. This iterative procedure is terminated when the loss of flow pressure in the three components reaches a steady state. The torque converter performance predicted with this method agrees well with experimental data.
Technical Paper

Front-End Airflow Rate Simulation

1988-11-01
881748
Front-end airflow predictions are generally carried out at the styling stage in the development process for vehicle cooling systems. These predictions have taken on increasing importance in recent years in studying the heat radiation capacities of the radiator. This paper presents a method for simulating front-end airflow rates. Two- and three-dimensional front-end airflow simulations are iirst analyzed experimentally. A technique for predicting a three-dimensional airflow from a numerical analysis of a two-dimensional airflow is then examined, and a comparison is made with actual vehicle data. A sample application of this simulation method is presented and a comparison is made with experimental data. Good quantitative agreement is seen between the calculated and experimental results. This paper also discusses the present status of three-dimensional analysis which is expected to become a major trend in the future.
Technical Paper

Accident Experience of Older AAA Drivers in Michigan

1988-11-01
881750
Older drivers typically are involved in certain types of multi-vehicle accidents. This paper studies one year of accident data from the AAA Michigan claim files involving drivers aged 55-64, 65-70, and 70+ to determine whether there is a pattern of increasing involvement in these accident modes. Of significance is that only those collisions were studied that could be cross-referenced with a police report to verify their accuracy as well as determine blame. The data indicate that there is a pattern of increasing frequency of involvement in four of seven accident types selected. More importantly, there is a perceptible increase in the rate at which drivers over the age of 71 are considered to be at fault in each of the accident types considered regardless of gender.
Technical Paper

Computer Simulation of Passenger Compartment Airflow

1988-11-01
881749
Numerical simulation of two-dimensional and three-dimensional air flow in automobile passenger compartments is described. The flow can be expressed by means of an incompressible Navier-Stokes equation for a narrow temperature range. The results were represented visually using animation and a color graphics system. The two-dimensional simulation showed that heat ansfer takes place chiefly by convection in vortices, and that the effects of heat transfer are minimal. In the three-dimensional analysis, shading was used to show the shape inside the compartment, and instantaneous stream lines and temperature distribution were depicted. The three-dimensional stream lines swirl upward at the front seat, and do not reach the back seat. The results gained from this study show that present theoretical flow analysis methods are close to being perfected. Further advances will require additional refinement of supercomputers and graphic engineering workstations.
Technical Paper

Instrument Panel Vibration, Durability and Structural Testing Approaches

1988-11-01
881788
The use of sinusoidal swept and random vibration testing for instrument panels (I/P's) and other automotive components is described. Random vibration, unlike sinusoidal swept testing, inputs energies from a broad band of frequencies. Means of establishing correlation between laboratory tests vs. Proving Ground results is presented.
Technical Paper

An Approach to Software Development of an Automotive Multiplex System

1988-11-01
881789
The paper describes the approach used to develop software for an automotive multiplex system. With reference to well-known techniques used in high-performance multiprocessor systems, our approach tries to solve problems related to operating low performance micro-controllers. In the first part of this paper we briefly describe the system structure on which the software is implemented. A detailed description of principles used in the software organization in given. Particular attention is placed on the data structure which is the assential reference for the description of the implemented program. We also treat in detail, the methods used for reading the inputs and driving the outputs in an automotive environment. A significant aspect of this study are the techniques followed for the design of the system functions. In conclusion, as a complementary topic, we briefly describe the transmission protocol used for data exchange.
Technical Paper

Rheological Characteristics of ER Fluids and Their Application to Anti-Vibration Devices with Control Mechanism for Automobiles

1988-11-01
881787
ER Fluids (Electro-Rheological Fluid) whose solidity or apparent viscosity varies very rapidly and reversibly to changes of electric field strength have been studied for a long time, chiefly in the UK, and the recent remarkable developments of electronics technology have made many engineers interested in its application to control devices, particularly in the automotive field. In this paper, the rhelogical characteristics of ER Fluids are first described on the basis of experimental data measured with the coaxial cylindrical rotatory viscometer that can be operated under electric fields and at different temperatures. Then, the semi-active control mounting system incorporating ER Fluid into a hydraulic mount on the basis of the “Pseudo-Sky Hook Model” is discussed both theoretically using the harmonic linearization method and experimentally, with a one degree of freedom vibration model.
Technical Paper

Progress Towards a Hydraulic Semiconductor for Vehicle Application

1988-11-01
881786
This paper contains a review of the development of a liquid semi-conductor and the reasons for it, especially with regard to the provision of electronically programmable hydraulic gear, as may be used in conjunction with vehicle ride and drive management systems. The progress towards this end is evidenced in terms of the characteristics of presently available Electro-Rheological or Winslow Effect fluids, along with an explanation of the methods of calculating their potential for automobile applications. Attention is drawn to some of the pitfalls that the designer will encounter in respect of the evaluation of fluid performance data and shortcomings of the presently available liquids.
Technical Paper

An Electric Vehicle Design Based on a High-Power, Sealed, Lead-Acid Battery

1988-11-01
881790
A passenger electric vehicle which can travel 100 miles at freeway speeds (55 mph) appears to be the most competitive, electric alternative to the conventional automobile. This paper discusses an electric vehicle design which uses a number of emerging technologies that, when taken together, provide the 100-mile range. The vehicle design takes advantage of technologies in sealed, lead-acid batteries; power electronics; aerodynamics; tires; and lightweight structures. A novel, high-power, sealed, lead-acid battery is used for energy storage and is the basis for the design. The battery is paired with a 60Kw. A.C. drive for the vehicle's power train. The A.C. drive consists of a transistorized inverter and induction motor. The batteries are thermally managed and charged with an on-board, non-isolated charger.
Technical Paper

Experimental Analysis of Transient Response in Motorcycle-Rider Systems

1988-11-01
881783
An experimental analysis has been made concerning rider sensation using several motorcycles. More specifically, the sensations evaluated are those which are related to the transient motions which are generated by a rider in an attempt to make two transient running patterns, one is to avoid obstacles and the other is lane change. Measurements were made of the steering torque, the accelerations of the major portions of the motorcycle, and the yaw and roll rates. This experimental analysis has revealed an indicator in this system which may be of value in the analysis of rider's awareness and reaction to transient mechanical motions. We have been able to obtain results from the measurement of delay of the motorcycle-rider system in its response to the yaw rate as related to the steering torque, and power spectral density of roll rate, and these may be effective equivalent for the indexes of analysis.
Technical Paper

Actively Controlled Damping in Electrorheological Fluid-Filled Engine Mounts

1988-11-01
881785
An adaptive engine mounting system is discussed that uses mounts filled with electrorheological (ER) fluid. The damping in the mounts is actively controlled based on feedback from sensors monitoring engine movement. Data are presented that demonstrate the performance of the adaptive system in controlling transient shocks superimposed on steady-state vibrations. These results were obtained using a custom-built test machine designed to simulate real-world operating conditions.
Technical Paper

MBT Control through Individual Cylinder Pressure Detection

1988-11-01
881779
Making use of spark-plug-washer type cylinder pressure sensors and a high-performance 16-bit microprocessor, the authors have developed a new control system (Nissan ECCS) of ignition timing for gasoline engine. Use of this system results in effective control, enabling each engine to deliver maximum torque and minimum fuel consumption at all conditions, regardless of changes in environmental conditions, etc.
Technical Paper

Analysis of the Behavior of Liquid in a Fuel Tank

1988-11-01
881782
The behavior of the liquid in the motorcycle fuel tank is an interesting theme from the viewpoint of the fuel meter construction, as effected by variance in the fuel pressure resulting from acceleration or deceleration, etc. It can be assumed that the behavior of the liquid in the fuel tank will be affected by the running pattern, the shape and capacity of the fuel tank, etc. Here is a report on an experiment recently made to observe how the liquid behaves in a partially fully enclosed tank. We simplified the tank shape and the involved conditions (to actually observe the behavior of the inside liquid by the suspension method.) Then we have analized the effectes according to different liquid containers, to different velocities, and to different liquid volumes as well as the time history variance in the internal pressure.
Technical Paper

Copper Cored Ground Electrode Spark Plug Design

1988-11-01
881777
New engine designs are placing an increasing demand on spark plug performance. The quest for higher specific power output and improved fuel economy has prompted advances in areas such as lean burn, fuel injection, turbocharging and valve train design. The spark plug must now ignite leaner mixtures and operate under more severe combustion chamber conditions. The copper-cored ground electrode facilitates spark plug designs which meet these increased performance demands. Performance criteria such as service life, ignitability, preignition protection and fouling resistance are greatly improved with copper-cored ground electrode spark plugs. These improvements are realized with leaded and unleaded fuels including those having high additive levels.
Technical Paper

Stability Analysis of Engine Revolution by a Chassis and Powertrain Dynamics Simulator

1988-11-01
881778
This paper discusses causes and the mechanism of surging, back and forth chassis oscillation which occurs in cars with electronically controlled multi-point gasoline injection systems. This occurs during sharp acceleration, engine braking deceleration, and low speed coasting, at rather low ratio gear positions. We conclude that the mechanism of surging is parametric coupled oscillation. This conclusion is based on experimental data analysts and parameter sensitivity analysis using a chassis and engine dynamics simulator. The elements of parametric coupled oscillation are: a forcing system composed of engine control systems, engine and power transmission systems; a resonance system composed of axle and frame-body translation systems; a feedback system composed of axle translation systems and wheel revolution systems.
Technical Paper

Development of a New Multi-Link Rear Suspension

1988-11-01
881774
Nissan is installing a newly developed multi-link rear suspension in its new 240SX model. This suspension achieves maximum improvement in handling and stability through unique toe control, enhanced dynamic geometry and optimized alignment. The incorporation of attitude control also works to provide flat ride characteristics by greatly mitigating jacking up and squatting motions. This paper discusses the development objectives, results of CAD/CAE analyses and experimental data obtained in tests of the new suspension installed in the 240SX.
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