For increasing the accuracy and applicability of the simulation that has been developed to predict the pressure pulsation response in a power steering system and uses of the transfer matrix method, this report studies the influence of the viscoelastic model parameters, the hose material and the pressure intensity.
Then this report compares the simulated and experimented frequency responses of realistic automotive power steering lines which have pressure hoses with tuning cables and verifies the validity of the simulation.

View full abstract

Compare to the former systems, recent hydraulic systems are designed on requirement as High Pressured, Miniaturise and High Controlability. Applying the usual antiwear type hydraulic fluid to the said recent hydraulic systems, troubles have been increasing such as filter or circuit stick due to the sludge occuring at an early point we have never considered. Therefore we have developed a no-sludge antiwear type hydraulic fluid made with a non-Zn-contained extreme-pressure additive and several kind of particular oxidation inhibitor. In this presentaiton, we will inform you about the comparison of practical efficiency with usual antiwear type hydraulic fluid and no-sludge antiwear type hydraulic fluid

View full abstract

The Rotary Blade Coupling (RBC) is a type of torque split couplings for 4-Wheel Drive (4WD) vehicles. RBC unit mainly consists of a wet multi-disk clutch and a pressure chamber with the blade rotating in high viscosity silicone oil. The pressure chamber generates clutch engaging hydraulic force, which depends on the differential speed between the input and the output shaft. The high viscosity silicone oil in the pressure chamber exhibits non-Newtonian fluid properties. This report presents the simplified flow analysis as the practical designing tool. Effects of non-Newtonian fluid properties of silicone oil are considered. Also the heat transfer modeling during the coupling operation is included in the calculation. Typical blade shape calculations and the experimental results to insure the analysis are shown.

View full abstract

NACHI CCV (hereinafter called CCV) is a miniature-sized vehicular transmission valve operated by solenoid for high speed applications. The design is a culmination of NACHI's probe into hydraulic control technologies, materialized in the form of a product through the precision machining expertise nurtured for more than a century by way of ball bearing production.
In the case of automatic transmission (hereinafter called AT), gear shift operations are controlled hydraulically by computer. Hydraulic valves open or close according instructions emanated by the computer to make gear shift happen.
The paper discusses a three-way valve design, developed and commercialized by NACHI which manifests appreciably better performance over the conventional two-way design.

View full abstract

The use of electrohydraulic control systems in vehicles has increased considerably in recent years, and these systems are continually becoming more advanced and sophisticated. In developing these systems, it is essential to conduct in-vehicle tests to evaluate vehicle dynamics and operation of the hydraulic system under development. With the aim of evaluating such systems in detail in bench tests, the authors have developed a real-time hardware-in-the-loop simulator. With this simulator, a vehicle numerical model is linked to an actual electrohydraulic control system to calculate the model in real time in combination with the operation of the system. As a result, experimental data nearly equal to the results of in-vehicle testing can be obtained in bench tests. Trial use of the simulator shows that it can be applied to many kinds of performance evaluations, except “feel” assessments, and is a useful tool in system development work.

View full abstract

Formed bellows accumulators have been mass produced for pulse absorbers of the vehicle active suspension systems since 1989, because of the features of no-gas-leakage and high-frequency-response. By these days' needs, pursuing more intensive space efficiency, we begin to design it so that some modes of input pressure may be in the range beyond the fatigue limit. On the other hand, we must make it clear that how the accumulator gets damaged by using within range beyond the fatigue limit.
In this report, we present a sample analysis and prognosis of the fatigue life of our accumulator. The prognosis is based on precise prediction of the system life and the Miner's law. We can apply this method to designing accumulators for automobile parts which we must guarantee for the entire period of the system life.

View full abstract

The basic subjects which are required for the hydraulic equipment such as noise, efficiency, high-pressure, leakage, operateability, function improvement, global standard and so on. Various research and development are carried forward to these subject. It introduces about the new generation switching valve with focusing on the operate-ability and function improvement.

View full abstract

Hydraulic cylinders are used to drive the car tilting mechanism equipped on the 300X next-generation body of the Shinkansen, which is currently being tested by the JR Tokai, Co., Ltd.
The 300X has been designed to achieve a maximum speed of 450 km/hr. It incluedes, as test elements, various stat-of-the-art technologies. The tilt of car must be maintained to reduce the centrifugal force which is generated when the tarin runs on a curve.(Fig. 1) The latest tilting mechanism is different from the conventional pendulum mechanism in which the natural swaying otion of the pendulum is used.
Instead, the new hydraulic cylinders activly control the tilting ofthe body of the train.

View full abstract

This report is about:
Electro-magnetic proportional valve used for water-hydraulic system
Explanation of structures of pilot and main valves, and regulator.

View full abstract

Various types of pneumatic servo valves are being used in practical applications in recent years. Most of them are however an adaptation of hydraulic servo valves and there have been no valves which can make the best use of pneumatic pressure characteristics. Use of nozzle flapper valves is only an exceptional case. Kolvenbach servo valves are developed for pneumatic applications and are provided with good static and dynamic characteristics. They are compact in size and low prices too.
This short abstract reports about their features and several examples of applications of the Kolvenbach servo valves in control systems.

View full abstract

ADEX VALVE is newly developed as new generation solenoid valves on the theme of downsizing and high speed operating according to the current market requrements. It composes of 4 series 62 types of valves and 9 series 42 types of manifolds such as A00, A05, Al2 and A20.
It is originally the so-called miniature range of valves to be designed 18mm body wide and narrower, its capability to operate a cylinder of φ40 in diameter. We have succeeded indeveloping ADEX VALVE downsizing and operating up to a cylinder of φ100 in diameter with the same 18mm wide of valves. Moreover it provides more variety to use them for the users in order to let ADEX VALVE have the variation of high response time, piping, wiring, etc. It progresses the production costs to minimize the parts range and make them in common in series.

View full abstract

The Series-F solenoid valves have been developed based on an entirely new concept by using KOGANEI's long-term accumulated technologies and they should become a great innovation in solenoid valves.
The Series-F solenoid valves have a versatility;(1) two tube sizes of an incorporated quick fitting (2) single or double solenoid (3) two piping directions, base piping or direct piping; therefore, they can be used in the various specifications without exchanges whichever function is needed.

View full abstract

When super limited express trains swing around one of the many curves on these older rail systems at high speed, centrifugal force can bounce passengers about. In order to keep passengers comfortable, they must slow down to negotiate curves. The active tilting trains controlled by pneumatic servo actuators keeps high speed and passengers comfortable. This whole system is composed of a curve detector, curve data memories, microcomputers making control signals, feedback circuits on swing angles and pneumatic servo actuators.

View full abstract

The NCR Regulator is an air pressure control system, in which a controller plays the major role to cause the pressure transmitter to detect the pressure in the air pressure circuit, compare the control pressure with the detected pressure and judge the comparison data, thereby providing the operation signals to make the predetermined pressure.
The Explosion S. V. combines the barrier which is capable of limiting both voltage and current with an energy-saving type of solenoid valve, thus providing the intrinsic safety solenoid valve.

View full abstract

Pneumatic Servo System has been studied and developed in Europe in the latter half of ‘80’s by the great progress of micro electronics and the develdpment of control software. At the same time, we (FESTO), one of the most biggest pneumatic manufacturers in the world, started to supply Pneumatic Servo System which can keep appropriate positioning accuracy, be operated rather easily and be supplied to the market with reasonable prices, and the no. of applications reached over thousand axes.
FESTO Pneumatic Servo System was introduced to the Japanese market in the beginning of 1994. Currently, it is used in the automobile industry, metal working machine, electric machine, handling machine, wood working machine, chemical machine, construction machine, packaging machine, food processing machine, and robot, etc.
The outline of FESTO Pneumatic Servo System, the examples of measurement results of control signals and the response comparison with the case driven with the normal solenoid valve are introduced here.

View full abstract

Pneumatic instruments have coped with new industries and new trend of technology. Hereinafter, express the flexible pneumatic instruments as “Smart Pneumatics”. Explain “Smart Pneumatics” through pneumatics relating semiconductor, i.e., pneumatics for clean room.

View full abstract

The nailing system consists of an air compressor, elastic tube, pressure reducing valve and a pneumatic nailing machine. As the pneumatic nailing machine of this system instantaneously consumes consumes a large quantity of air which exceeds the supply capacity of the compressor, the supply pressure of the compressor may become lower than the pressure initially set by the reducing valve in case of continuous nailing works. This paper discusses a very unstable system coupled with pulsatory motions as well as the difference between the conventional system and the high pressure system.

View full abstract

This paper describes a control technique and analysis of transient phenomena of Air Over Hydraulic (AOH) brake system. A deceleration coefficient, which is defined as a ratio of deceleration of a vehicle to control input fed to a braking component, was measured experimentally. On-line estimation of the deceleration coefficient was examined. Adaptive control using the estimated coefficient was carried out. From experiment using a test vehicle, it has been demonstrated that braking process was precisely controlled by the adaptive control technique. It became clear thatthe transient characteristics of AOH brake system are subject to the compressibility of air and the mass of brake oil.

View full abstract

This report describes the main features of a high precision actuator that is now required for assembling or testinghigh-tech products. The production equipments are highly sophisticated and there are more demands for accurate andcompact actuating units. Along with the demands, linear ball bearing guides are widely used in coupling with air cylindertype actuators. We introduce here the new concept linear guide unit driven by compact magnetically coupled aircylinder, which offers full specifications of the guide in the utmost compactness.

View full abstract

The variable speed rodless cylinder system has tow magnet type rodless cylinders which aremechanically coupled with both slide tables mounted on the cylinder tubes. One cylinder is drivenby pneumatic pressure, and the other is filled with the ER fluid. The bypass piping is laid such thatthe ER fluid circulates as the piston move. An electrode which located in the middle of this bypasspiping is applies an electric field to the ER fluid. The viscous resistance of the ER fluids againstthe pneumatic driving force is operated by the applied electric field to the ER fluid. In consequencethis system enable the pneumatic cylinder to be controlled smoothly any speed setting not only atstart up and stoppage but also any position of the stroke.

View full abstract

OHC-Sim is an innovative program for oil-hydraulic circuit simulation, which is being developed with the support ofJapan Hydraulics and Pneumatics Society (JHPS). OHC-Sim includes a user friendly GUI (Graphical User Interface) inMicrosoft Windows 95 environment. OHC-Sim provides not only easy design of oil hydraulic circuits, but also quickevaluation of dynamic performance.

View full abstract