PENYUSUNAN (FITTING) DATA TITIK (POINT CLOUD) DARI PROSES PEMINDAIAN (SCANNING) 3 DIMENSI PADA PRODUK CYLINDER HEAD COVER

Mesin pemindai tiga dimensi merupakan suatu alat pemindai titik-titik pada permukaan suatu obyek benda kerja. Keluaran dari alat pemindai ini adalah data titik (point cloud) yang merupakan suatu set data titik titik dalam sistem koordinat. Data-data titik ini digunakan untuk membuat model CAD 3 dimensi. Pemodelan 3 dimensi ini dapat digunakan dalam proses manufaktur, metrologi/inspeksi, visualisasi, animasi dan lain-lain. Makalah ini bertujuan untuk menyusun data-data titik yang didapatkan dari proses pemindaian produk cylinder head cover sehingga data yang diperoleh dapat disusun mirip perwujudan produk contoh yang dipindai. Tahapan yang dilakukan adalah pemindaian 3 dimensi, perbaikan, penyusunan berkas data, analisa simpangan, dan penyatuan berkas. Dengan tahapan-tahapan itu hasil yang didapatkan diharapkan memiliki deviasi rata-rata yang optimum. Hasil analisis deviasi dari data titik-titik (point clouds) menunjukkan bahwa pemindaian berkas pada bagian permukaan luar memiliki batas deviasi rata-rata yang lebih kecil (-0.1983 ~ 0.1912) bila dibandingkan dengan pemindaian berkas pada permukaan bagian dalam dari cylinder head cover (-0.6769 ~ 0.6319).

Study on Low Profile SMC for the Production of Cylinder Head Cover

In this paper, one kind of low profile SMC (Sheet Moulding Compound) has been introduced and used to produce the cylinder head cover. Two kinds of low profile additives (polystyrene and polyester resin) were blended and added to the resin to compensate for the cure shrinkage. The cure shrinkage of obtained low profile SMC was only 0.05%, which met the requirements for class A surfaces. Test sample were prepared by mould pressing. Properties testing of SMC were conducted according to the National standards. Results showed that all of the indexes of the low profile SMC met the specifications for the production of cylinder head cover. Some properties of cylinder head cover products have been investigated in detail. Experimental and performance testing results showed that this kind of cylinder head cover is suitable for the automotive application.

Application of the AGST Method to the Vibration Analysis of the Diesel Engine Cylinder Head Cover

The vibration signal of diesel engine is typically non-stationary and time-varying signal, with complicated transient components. With adaptive concentration method controlled by an additional parameter m, an adaptive generalized S transform (AGST) is developed in this paper. The simulation shows that the AGST method has a better time-frequency resolution than S transform. The AGST method is then applied to analyze the vibration signal of the cylinder head cover of a four-cylinder diesel engine. The result indicates that the time-frequency representation of the vibration signal obtained by AGST has a good resolution, and the vibration components, such as combustion shock and valve-slap, can be exactly identified. The research is of great significance for the structural optimization and vibration control for the diesel engine.

Modeling the Automotive Engine Components With Viscoelastic Gasket Elements

The present paper presents a methodology to model the automotive engine components using newly developed viscoelastic gasket elements. The viscoelastic gasket element is one-dimensional element with load and deflection defined in the thickness direction only, thus has great computational efficiency. In addition, this element has the ability to incorporate the frequency-dependent viscoelastic properties of the materials and thus can be used to model the vibration and acoustic performance of the engines and subsystems. In the present study, an elastomer isolated engine cylinder-head cover assembly is modeled. The results obtained are consistent with the experimental measurements and with the work done earlier using viscoelastic shell elements.

Microstructure Simulation of Die Casting AZ91D Alloy

Physical and mathematical models of microstructure evolution during the solidification process of die casting AZ91D alloy were investigated in this paper. Coupled with solute concentration, a modified three-dimensional cellular automaton (CA) model was proposed. Considering the solute enrichment and the formation of eutectic microstructure, these models can reproduce the whole microstructure evolution process of Mg alloy, from the formation of primary phase to the eutectic transformation. The microstructure of the AZ91D alloy cylinder head cover die casting was simulated with the proposed models. The simulated results are in agreement with the experimental.

Development of High Temperature Creep Resistant Magnesium Alloys for Die Casting

A series of high temperature creep resistant magnesium alloys for die casting based on AZ91 were successfully developed by the addition of Rare Earth, and Calcium. The original target of magnesium alloy development was aimed at cylinder head cover of high power diesel engine, and tried to satisfy the temperature demands of gear-box house. The tensile property at room temperature, creep behavior at 150ı，and analysis of microstructure were discussed in this paper. The results showed that these alloys has potential for die casting to produce power-train parts, and greatly decrease the weigh of parts.