Study on Non-Axisymmetric 3D Curved Surface Turning by Driven-Type Rotary Tool Synchronized With Spindle

2021 ◽  
Author(s):  
Akane Ishizuka ◽  
Narimasa Ueda ◽  
Yoshitaka Morimoto ◽  
Akio Hayashi ◽  
Yoshiyuki Kaneko ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Curved Surface ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Cam Mechanism ◽  
Rotary Tool ◽  
Variable Valve ◽  
New System

Abstract Since shifting to electric vehicles as a countermeasure against global warming is not always easy to complete, the hybrid car has been considered as another possible solution. However, based on the calculation of total CO2 emissions, all hybrid cars which will constitute 90% of all cars are expected to be equipped with an internal combustion engine even after 2030. Therefore, further efficiency improvement of the internal combustion engine is necessary. One of the key factors is the variable valve timing and variable lift with the 3D cam mechanism. Since conventional technology uses a complicated link mechanism and servo motor control, this leads a problem to set into small cars or motorcycles because they cannot afford to install the variable valve timing and variable lift with cam mechanism. To solve this problem, a cam shape with a three-dimensional curved surface has been proposed. In order to create this shape, the machining method for non-axisymmetric curved surface turning (NACS-Turning) is required. To build the new system, our research group has proposed a new machining method using a driven type rotary tool and a linear motor driven moving table to enable to achieve NACS-Turning. In this new system, a new tool rotation axis (B axis) is adopted to synchronize its rotational position with the rotational position of the spindle (C axis) holding the workpiece, the X1-, X2-, and Z-Axis positions in total. In this paper, the new hardware configuration is proposed to overcome the present machining accuracy.

Study on Non-Axisymmetric 3D Curved Surface Turning by Driven-Type Rotary Tool Synchronized With Spindle

2020 ◽  
Author(s):  
Akane Ishizuka ◽  
Kensuke Nakagawa ◽  
Yoshitaka Morimoto ◽  
Akio Hayashi ◽  
Yoshiyuki Kaneko ◽  
...  
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Curved Surface ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Cam Mechanism ◽  
Rotary Tool ◽  
Variable Valve ◽  
New System

Abstract Since shifting to electric vehicles as a countermeasure against global warming is hard to complete, the hybrid car has been considered as another possible solution. However, based on the calculation of total CO2 emissions, all hybrid cars which will constitute 90% of all cars are expected to be equipped with an internal combustion engine even after 2030. Therefore, further efficiency improvement of the internal combustion engine is necessary. One of the key factors is the variable valve timing and variable lift of the cam mechanism. Since conventional technology uses a complicated link mechanism and servo motor control, this creates a problem to build small cars or two-wheeled vehicles because they are not big enough for the size and weight of the two important parts: the variable valve timing and variable of cam mechanism, which won’t fit. To solve this problem, a cam shape with a three-dimensional curved surface has been proposed. In order to create this shape, the machining method for non-axisymmetric curved surface turning (NACS-Turning) is required. To build the new system, our research group has proposed a new machining method using a driven rotary tool and a linear motor driven moving table to enable to achieve NACS-Turning. In this new system, a new tool rotation axis (B axis) is adopted to synchronize its rotation position with the rotation position of the spindle (C axis) holding the workpiece and the X1-, X2-, and Z-Axis positions in total. In this paper, the new hardware configuration is proposed to overcome the present machining accuracy from the point of non-circular machining method.

Study of the Variable Valve Timing Effects on Combustion Quality and Fuel Consumption of an Internal Combustion Engine

2020 ◽  
Author(s):  
Augusto César Teixeira Malaquias ◽  
Nilton Antonio Diniz Netto ◽  
José Guilherme Coelho Baêta ◽  
Alysson Fernandes Teixeira ◽  
Sérgio Augusto Passos Costa
Keyword(s):  
Internal Combustion Engine ◽  
Fuel Consumption ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Timing Effects ◽  
Variable Valve

scholarly journals Optimal Degree of Hybridization for Spark-Ignited Engines with Optional Variable Valve Timings

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8151
Author(s):  
Andyn Omanovic ◽  
Norbert Zsiga ◽  
Patrik Soltic ◽  
Christopher Onder
Keyword(s):  
Internal Combustion Engine ◽  
Fuel Consumption ◽  
Fuel Economy ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Valve Train ◽  
Effective Measure ◽  
Optimal Degree ◽  
Variable Valve Train ◽  
Variable Valve

The electric hybridization of vehicles with an internal combustion engine is an effective measure to reduce CO2 emissions. However, the identification of the dimension and the sufficient complexity of the powertrain parts such as the engine, electric machine, and battery is not trivial. This paper investigates the influence of the technological advancement of an internal combustion engine and the sizing of all propulsion components on the optimal degree of hybridization and the corresponding fuel consumption reduction. Thus, a turbocharged and a naturally aspirated engine are both modeled with the additional option of either a fixed camshaft or a fully variable valve train. All models are based on data obtained from measurements on engine test benches. We apply dynamic programming to find the globally optimal operating strategy for the driving cycle chosen. Depending on the engine type, a reduction in fuel consumption by up to 32% is achieved with a degree of hybridization of 45%. Depending on the degree of hybridization, a fully variable valve train reduces the fuel consumption additionally by up to 9% and advances the optimal degree of hybridization to 50%. Furthermore, a sufficiently high degree of hybridization renders the gearbox obsolete, which permits simpler vehicle concepts to be derived. A degree of hybridization of 65% is found to be fuel optimal for a vehicle with a fixed transmission ratio. Its fuel economy diverges less than 4% from the optimal fuel economy of a hybrid electric vehicle equipped with a gearbox.

scholarly journals GAS DISTRIBUTION PHASES HYDRAULIC CONTROLLED INTERNAL COMBUSTION ENGINE VALVES

2022 ◽  
Vol 16 (4) ◽  
pp. 47-52
Author(s):  
Nail Adigamov ◽  
Andrey Negovora ◽  
Larisa Zimina ◽  
Alexey Maximov
Keyword(s):  
Internal Combustion Engine ◽  
High Speed ◽  
Combustion Engine ◽  
Hydraulic Drive ◽  
Internal Combustion ◽  
Valve Timing ◽  
Gas Distribution ◽  
Time Section ◽  
Engine Valves ◽  
Opening And Closing

The efficiency of an agricultural car or tractor depends on the characteristics of the engine determined by the gas distribution mechanism (GRM). Traditional timing with fixed valve timing does not provide high-quality gas exchange at all engine operating modes. The aim of the work is to improve the characteristics of the engine by using the hydraulic drive of the timing valves. The drive allows you to turn off individual valves, set the moments of their opening and closing in an arbitrary way, provide several triggering of the internal combustion engine valves during the operating cycle. The drive is controlled by an electronic control unit (ECU). The advantage of the drive is its ease of integration into the internal combustion engine. The hydraulic drive ensures that the timing valves are lifted to a height of about 14 mm. The law of displacement of the valve, revealed experimentally, is close to trapezoidal. The use of a hydraulic valve drive has a positive effect on the "time-section" factor in the area of low and medium crankshaft rotational speeds. The increment of the factor "time-section" is due to the significant speeds of opening and closing the valves. Due to the peculiarities of the kinematic characteristics of the movement of the valves when using a hydraulic drive for their movement, the use of serial phases of gas distribution of the engine is impractical. Numerical modeling of the operation of the internal combustion engine determined the regularity of the change in valve timing from the high-speed operating mode of the engine. Optimization criterion is the achievement of maximum engine power. When choosing the valve timing, the possibility of meeting the intake and exhaust valves with the engine piston was excluded. The use of optimal phases leads to an increase in power up to 4.5% at a low crankshaft speed. With an increase in the speed mode, the increase in power decreases, and with a high frequency of rotation of the crankshaft, its slight decrease (1.4%) is observed. An increase in torque, up to a power utilization factor of 0.9, and its subsequent decrease, allow stabilizing the vehicle speed on a road with variable resistance. An increase in the working pressure in the hydraulic drive of the valves makes it possible to intensify gas exchange even at a high speed of rotation of the crankshaft

Influence of the combustion chamber geometry on the scavenging of a four-stroke internal-combustion engine during the valve overlap period

2016 ◽  
Vol 230 (14) ◽  
pp. 1873-1890
Author(s):  
Nicolas-Ivan Hatat ◽  
David Chalet ◽  
François Lormier ◽  
Pascal Chessé
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
One Dimensional ◽  
Digital Testing ◽  
The One ◽  
Small Engines ◽  
Variable Valve ◽  
Valve Overlap ◽  
The Impact

The performance of an internal-combustion engine is directly related to the fuel quantity that can react with the oxygen in the air during the exothermic oxidation step, also called combustion. Thus, the amount of fuel introduced is intrinsically linked to the air volume that can be admitted into the cylinder (air filling of the cylinder). Hence keeping the air in the cylinder is one of the most important concepts to predict in simulations. Nevertheless, the phenomenon of air filling depends on many parameters. Also, the discharge coefficients, and the impact of the piston presence near the valves on the flow, during valve overlap are investigated. For this, a digital flow bench is constructed to reproduce a series of tests carried out on a flow test bench functioning as a result of the reduction in the pressure. In this paper, the engine studied is a 125 cm3 single-cylinder four-stroke atmospheric type with two valves. Thus, the idea of this paper is to treat the case of engines with large valve overlaps as small engines or engines with variable valve timing. First, traditional tests through a single valve are performed. The forward and reverse directions are systematically tested to ensure proper operation of the digital testing, and to determine the differences between tests and simulations in the case of conventional configurations. Then, the flow through the entire cylinder head, i.e. the intake valve–cylinder with piston–exhaust valve system, is tested and studied. The aim is to compare the results obtained by the tests and the simulations during the valve overlap period. Significant differences were highlighted between the rates measured in one-dimensional simulations and in the tests. It was noteworthy that the one-dimensional code overestimated the mass passing through the system during valve overlap by about one fifth of the estimated mass passing through the system from the results obtained with the test rig.

Sign in / Sign up

Export Citation Format

Share Document