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                  ENGINEERING NEWS IN BRIEF
                        E-Mail Newsletter

                               No.93
             Issued by the Asian TOP Panel, September 2009

           The Chinese Mechanical Engineering Society (CMES)
           The Institution of Engineers, Indonesia (PII)
           The Japan Society of Mechanical Engineers (JSME)
           The Korean Society of Mechanical Engineers (KSME)

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    According to the agreement made in the 2nd Asian TOP Panel Meeting,
the ENGINEERING NEWS IN BRIEF (E-mail newsletter) has now been edited
by the JSME for the year 2009.

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[Contents]

1)@Hydraulic-Mechanical Transmission for Motorcycle (Source: JSME)
2)@Shape evaluation of 3D Micro Products Using SFS Method (Source: JSME)
3)@Development of the Sound Absorber Panel Composed of Micro Perforated Aluminum @@Plate and Foil (Source: JSME)
4)@Okayama Biomedical Engineering Professional (OBEP) -for the company having hope @to develop medical devices instruments- (Source: JSME)
5)   Design and Performance Characteristic Analysis of Servo Valve-type Water Hydraulic @Poppet Valve (Source: KSME)
6)   The Measurement of Thermal Conductivities Using the Photothermal Deflection @Method for Thin Films with Varying Thickness (Source: KSME)
7)    An Investigation on the Fuel Behavior for a PFI Type Motorcycle Engine (Source: @KSME)

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1) Hydraulic-Mechanical Transmission for Motorcycle (Source: JSME)

     Yoshihiro Yoshida, Honda R&D Co., Ltd. Motorcycle R&D Center

 An automatic transmission for motorcycle of the new design that added the efficiency improvement mechanism and the automatic start clutch mechanism was developed based on the hydraulic mechanical transmission with an original one axis structure.
 The efficiency improvement at Top ratio was realized by the reduction of the quantity of leak oil and the reduction of the friction losses in hydraulic motor. It depends on blocking of high pressure inflow to the hydraulic motor piston by the distributor spool valves on the hydraulic motor side.
 The main structure of the automatic start clutch consists of the oil passage connecting the high-pressure chamber and the low-pressure chamber, spool valve clutch for controlling connection and disconnection of the oil passage, and mechanical governor for controlling the movement of the spool valve clutch with the number of input revolutions. This clutch had the sensing structure of the driving force and realized the start characteristic in proportion to the throttle opening.
 This Automatic transmission provides multi-functions with excellent efficiency in a compact body, and is the optimum CVT for motorcycles.

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2) Shape Evaluation of 3D Micro Products Using SFS Method (Source: JSME)

     Takashi Maekawa, Yokohama National University

 We present a method to evaluate the shape of 3D micro products from several 2D images of an object taken from different views. The data acquisition system consists of a digital microscope, and a computer controlled turntable. We employ the Shape-From-Silhouette (SFS) method, which constructs a voxel-based 3D model from silhouette images. The concave shapes are further carved by the space carving technique. In order to make the resulting model compatible with the CAD/CAM system, the voxel model is converted into a triangular mesh using the Marching Cubes algorithm. Since the mesh generated from the voxel model by using the Marching Cubes algorithm inherits the staircase effect, the mesh is adjusted to recover the object precisely by using silhouette images. Finally, we evaluate the accuracy of the proposed method. The reconstructed models of complex objects show the effectiveness of the proposed inexpensive 3D shape evaluation system for micro products.

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3) Development of the Sound Absorber Panel Composed of Micro Perforated Aluminum Plate and Foil (Source: JSME)

     Ichiro Yamagiwa, Kobe Steel, Ltd.

 The fiber sound absorbing material often has subjects, such as a health issue by scattering of the fiber produced by the aged deterioration and falure of a protection film, the application difficulty resulting from a hardness, weatherability, a heat resisting property, independence nature, recycling efficiency, etc. Moreover, in the motor-car and the railway-vehicle field, environmental preservation and improvement in the speed are demanded, and importance is attached to the weight saving and the sound-noise problem as an antimonial subject. In order to solve these subjects, research and development of the sound absorbing material constituted from an aluminum micro-perforated panel have been furthered. By applying the attenuation theory of the air which passes along a hole part to the transfer-matrix method based on one-dimensional wave motion theory, the method of predicting the frequency response characteristics of an acoustic absorption coefficient from the dimensions of a perforated panel was drawn, and it applied to the sound structural design technology of the perforated panel. The noise barrier made from aluminum micro-perforated panel developed using this design technique is explained.

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4) Okayama Biomedical Engineering Professional (OBEP) -for the company having hope to develop medical devices instruments- (Source: JSME)

     Takeru Naiki, Okayama University of Science

 There are some paticular steps to develop medical devices and medical instruments, such as safety test, animal test, clinical trials, manufacturing approval, and so on.  These severe hurdle prevents the embarkation of new commers upon health care industry.  This year we started the educational program for engineers to tutor the basical method for developing medical devices and instruments with the supportment by Japan Science and Technology Agency (JST).  This program named gOkayama Biomedical Engineering Professional (OBEP)h has been looking widely around Okayama Prefecture for the engineers who wants to learn about the above.  This program will be held on untill 2014.  Please contact to our Home Page, http://www.bme.ous.ac.jp/~OBEP/.

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5) Design and Performance Characteristic Analysis of Servo Valve-type Water Hydraulic Poppet Valve (Source: KSME)

     Sung-Hwan Park, Pusan National University

 For water hydraulic system control, the flow or pressure control using high-speed solenoid valve controlled by PWM control method could be a good solution for prevention of internal leakage. However, since the PWM control of on-off valves cause extensive flow and pressure fluctuation, it is difficult to control the water hydraulic actuators precisely. In this study, the servo valve-type water hydraulic valve using proportional poppet as the main valve is designed and the performance characteristics of the servo valve-type water hydraulic valve are analyzed. Furthermore, it is demonstrated through experiments that a decline in control chamber pressure that follows the change of pilot flow is caused by the occurrence of cavitation around the proportional poppet, and that fundamental characteristics of the developed valve remain unaffected by the occurrence of cavitation.

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6) The Measurement of Thermal Conductivities Using the Photothermal Deflection Method for Thin Films with Varying Thickness (Source: KSME)

     H. J. Kim(1)/J. H. Kim(1)/P. S. Jeon(2)/J. Yoo(2)
     (1)Ajou University
     (2) KIBO Technology Fund

 This study considers non-contact methods that obviate the causes of measurement error, such as thermal contact resistance and the unnecessary destruction of samples. Among the methods, the photothermal deflection method has been adopted and developed to measure the thermal conductivities of thin-film materials. To apply the developed method for thin films, bi-layered materials are manufactured by depositing the film on Corning 7740 glass plates. The study also investigates the optimal modulation frequency, as related to the thermal diffusion length of the sample, for measuring thermal conductivities of thin films.. Aluminum, TiO2, and Si3N4 films with micro/nanometer thickness were selected as the objects for measurement; the thermal conductivities of these films were experimentally measured. Samples of thickness ranging from 1 ? to 200 ? were prepared to measure the variations in thermal conductivities with thickness. It was observed that the thermal conductivity in submicroscale films decreased as the thickness was reduced.

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7) An Investigation on the Fuel Behavior for a PFI Type Motorcycle Engine (Source: KSME)

     Hyungmin Kim/Kihyung Lee,
     Hanyang University

 Recently, the electrically controlled fuel injection type motorcycle has been emphasized in order to meet regulations for exhaust emissions. However, there are many difficulties in selecting the control parameters because the pulsation phenomenon occurs in the intake port due to the higher speed operating range and the smaller layout than for a passenger car. Therefore, we investigated the injector spray characteristics which are applied to a 4-valve motorcycle gasoline engine. The spray characteristics were visualized by using a CCD camera synchronized with the stroboscope at 6000 rpm. Furthermore, we compared the simulation results using the VECTIS code with experimental results. The results showed that the trajectory of the spray was directed towards the lower wall of the intake port when the fuel was injected at closed valve timing. On the other hand, when the fuel was injected at open valve timing, a large portion of the fuel was lifted towards the upper half of the port. In addition, open valve injection makes fuel evaporation time short; this resulted in better mixture formation than a closed valve injection. From this result, we found that injection timing has a great effect on the mixture formation within a motorcycle cylinder.


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Editor : International Affairs Committee
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