จำนวน Repository ( 71 )

การศึกษาการใช้พลังงานในเครื่องอัดไฮดรอลิก
การศึกษาการใช้พลังงานในเครื่องอัดไฮดรอลิก

Recently Hydraulic Press has been generally used as a labor-saving device in several functions through industrial section. Previously most of the factory merely concern about using this powerful device and that caused so much electric energy wasted during the pending process on equipment transformation. Therefore our team initiated a conceptual study of energy consumption on using hydraulic press. The invention of hydraulic press for the study of electric energy requires hydraulic devices installation. This includes 3.7 kW 3 phases system induction motor and VSD hydraulic pump single shaft 2 sets set 1 low flow high pressure at flow rate 3.65 liters per minute and set 2 high flow low pressure at flow rate 6.79 liters per minute and total flow rate 10.44 liters per minute pressure relief valve and 2 ports 2 positions Bypass control valve and 4 ports 3 positions directional control valve double acting cylinder 100 mm diameter and 250 mm stroke and pressure gauge. The experiment on energy consumption using hydraulic press has been considered in 5 cases. Each case operated by different hydraulic devices in order to observe the differences of energy consumption. The result of experiment showed that case 1 had electric energy lost the most the rate of loss will increase as a percentage of the increase in pending. Case 2 to 4 with the lost of electric energy are similar. Case 5 is bringing the case 4 added VSD to adjust the speed of the electric motor is reduced to 435 rpm during the waiting period so this case had the lost of energy is minimal. After comparative experiment between case 1 and the other 4 cases during the pending process on equipment transformation at 20% - 200% it revealed that case 2 reduced electric energy wasted more than case 1 accounted for 17.07% - 30.46% while case 3 to 5 reduced electric energy wasted more than case 1 accounted for 16.06% - 29.52% 17.37% - 30.80% and 23.90% - 50.55% respectively

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การศึกษาจุดศูนย์กลางมวลและสัดส่วนการเบรกที่ส่งผลกระทบต่อเสถียรภาพการบังคับยานยนต์ : เครื่องทดสอบจุดศูนย์กลางมวลสำหรับรถยนต์
การศึกษาจุดศูนย์กลางมวลและสัดส่วนการเบรกที่ส่งผลกระทบต่อเสถียรภาพการบังคับยานยนต์ : เครื่องทดสอบจุดศูนย์กลางมวลสำหรับรถยนต์

The aim of this research is to create the center of mass testing machine for vehicles with maximum mass 3000 kilograms. By the performance of this machine is able to determine the center of mass 3 axis by horizontal longitudinal and vertical. On the other hand the verities of mass from 50 to 250 kilograms and the several of weight distribution at horizontal and longitudinal are applied to the condition of testing for reasonable to the position of the center of gravity for vehicle. The result of research discovered to the performance of center of mass tester was activated following to test conditions. Furthermore the position of the horizontal of center of gravity depends on the weight distribution at horizontal axis and an increasing of mass under non-uniform along the longitudinal and horizontal axis. In term of the position of the longitudinal of center of gravity the weight distribution at longitudinal axis and an increasing of mass rate are points. Otherwise the weight distribution at longitudinal axis and an increasing of mass are effect to the position of the vertical of center of gravity.

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การวิเคราห์ความน่าเชื่อถือได้ในการทำงานของเครื่องจักร และหาสาเหตุของเครื่องจักรเสีย: กรณีศึกษาโรงงานผลิตชิ้นส่วนรถยนต์
การวิเคราห์ความน่าเชื่อถือได้ในการทำงานของเครื่องจักร และหาสาเหตุของเครื่องจักรเสีย: กรณีศึกษาโรงงานผลิตชิ้นส่วนรถยนต์

This research proposes reliability analysis in order to find the probability that a machine will work properly the failure rates of a machine and the factors related to the failure rates. The data were collected from 8 types of machines in an autoparts manufacturing factory. They consist of the times measured from the first day of the study until the machine produces defective product workers and production steps. The study duration is 90 days. The results show that the probability that the machine type 4 will work properly more than days is 0.40 machine type 5 more than 68 days is 0.32 machine type 6 more than 72 days is 0.31 machine type 8 more than 85 days is 0.26 machine type 9 more than 109 days is 0.80 machine type 10 at more than 52 days is 0.38 machine type 11 more than 71 days is 0.32 and the probability that the machine type 12 will work properly more than 85 days is 0.26. The failure rate of the machine type 4 at day 51 is 6.61 machine type 5 at day 68 is 1.61 machine type 6 at day 72 is 0.77 machine type 8 at day 85 is 1.26 machine type 9 at day 109 is 1.31 machine type 10 at day 52 is 0.92 machine type 11 at day 71 is 1.24 and the failure rate of the machine type 12 at day 85 is 2.15. The factors influencing on the failure rates are worker group 2 and production step 3 at the significance of 0.05.

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Research and development on paddy washing machine for households rice milling machines
Research and development on paddy washing machine for households rice milling machines

The objectives of this study were to develop the paddy washing machine for community rice milling machines to extend this technology to rural community and introduce to commercial production. The experiments were conducted at the Department of Agricultural Engineering and Technology Faculty of Agriculture and Natural Resource Rajamangala University of Technology Tawan-ok Bangpra Campus Sriracha Chonburi. The results showed that paddy washing machine was suitable for high moisture content paddy between 20-25 % and washing for 1-3 minutes demonstrated better milling quality than unwashed paddy. Performance test of this developed paddy washing machine using drum speed at 35 rpm drum slopes of 1 2 and 3 degree and 21.60 % MC KDML 105 paddy could reach capacity about 150-200 kg/hr. The milling quality was significantly different at 95% confidence level from unwashed paddy. Furthermore this machine provided 1% better in purity and 11% better head rice yield at the same milling degree. From the study it can be concluded that increasing drum slope gave higher capacity higher power efficiency and lower water usage. The best condition was working with drum slope of 3 degree. The paddy washing process gave higher purity of paddy head yield and power efficiency of washing process while the color property was not significantly different from unwashed paddy at the same milling degree.

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Optimization for sewing machine setup using experimental design technique
Optimization for sewing machine setup using experimental design technique

The objective of the research was to identify the optimized thread tensile values for the setup of Model D – We 1218-55 computerized 18-needles sewing machine in order to minimize a number of times the machine halts. The cause of the sewing machine halting which reduced the efficiencies of the machine was found to be torn threads. In order to maximize the efficiencies the experimental design technique was utilized to find the optimal values for five types of cloth: polo tc-cool cotton jacket and shirt. The method involved three nested designs which are the type of thread number of sewing layers and thread-hole size. The three thread tensile levels experimented were low (2 oz.) medium (5 oz.) and high (8 oz.) and the response was the number of times the machine halted in the span of 30 minutes. The ANOVA (Analysis of Variance) used for the experimental design showed that the three factors significantly affected the machine’s halt. The number of times the machine halted was used to create Surface Plot with polynomial trend-lines and the quadratic equation was applied to determine the optimal value for each type of thread number of sewing layers and thread-hole size. The values obtained were then set for another experiment the results of which were that the sewing machine halted less frequently and the efficiencies thus increased about by 77.01%.

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