Jingzhou, China
Jingzhou, China

Time filter

Source Type

Zhou L.R.,Nanchang University | Wan H.M.,Jiangling Motors Co.
Advanced Materials Research | Year: 2011

On the basis of the traditional geometric method for blank expansion of rectangular box, the deformation characteristic in drawing process of rectangular box is analyzed. A new calculation formula for blank expansion of rectangular box is presented, and blank expansion graph of rectangular box is more precise than that of the traditional geometric method. The edge of rectangular box is flatter without trim by experiment. The calculation of blank expansion is useful for application. © (2011) Trans Tech Publications, Switzerland.

Deng G.-T.,Ningbo University | Deng G.-T.,Jiang Ling Motors Co. | Wang H.-R.,Ningbo University | Chen D.-N.,Ningbo University
Gongcheng Lixue/Engineering Mechanics | Year: 2014

Tensile split Hopkinson bar (TSHB) tests for QP980CR steel sheet specimens were optimized by using numerical simulation. The static tensile tests on an 810 material test system (MTS) and the dynamic tensile tests on TSHB at different strain rates and temperatures were performed for these specimens. Based on the stress-strain data obtained from static and dynamic tensile tests, J-C type tensile constitutive equation of this material was determined. The effects of specimen scale on the experimental results were also analyzed.

Tan S.L.,Nanchang Hangkong University | Zhou Q.,Nanchang Hangkong University | Fu J.B.,Jiangling Motors Co. | Fu H.,Nanchang Hangkong University
Advanced Materials Research | Year: 2014

The influences of different pulse voltage, discharging frequency, pouring temperature and mold temperature on marostructure of Mg97Y2Cu1 alloy under pulsed direct current magnetic field (PDCMF) were studied and the related mechanism was also discussed. The results show that grains of Mg97Y2Cu1 alloy can be refined greatly by PDCMF treatment. Macrostructure of the alloy is changed from coarsened grains to complete fine equiaxed grains. When the pulse voltage is at 0-250V, grain size of the alloy decreases dramatically as pulse voltage increases. When the discharging frequency is at 1-10Hz, grain size of the alloy increases firstly, then decreases, and the turning point is 5 Hz. The change of grain size is not obvious, when the discharging frequency increases from 1 Hz to 5 Hz. When the discharging frequency reaches 10 Hz, the effect of grain refinement is the best. When the mold temperature is at 20-600°C or the pouring temperature is at 660-750°C, grain size of the alloy with PDCMF treatment decreases grossly with the increase of the mold temperature or the pouring temperature. The higher the pouring temperature or the mold temperature, the better the effect of grain refinement with PDCMF treatment. © (2014) Trans Tech Publications, Switzerland.

Hu T.,Jiangling Motors Co. | Teng H.,Jiangling Motors Co. | Luo X.,Jiangling Motors Co. | Chen B.,Jiangling Motors Co.
SAE International Journal of Engines | Year: 2015

Turbocharged gasoline direct injection (TGDI) engines often have a flat torque curve with the maximum torque covering a wide range of engine speeds. Increasing the high-speed-end torque for a TGDI engine provides better acceleration performance to the vehicle powered by the engine. However, it also requires more fuel deliveries and thus longer injection durations at high engine speeds, for which the multiple fuel injections per cycle may not be possible. In this study, results are reported of an experimental investigation of impact of fuel injection on dilution of the crankcase oil for a highly-boosted TGDI engine. It was found in the tests that the high-speed-end torque for the TGDI engine had a significant influence on fuel dilution: longer injection durations resulted in impingement of large liquid fuel drops on the piston top, leading to a considerable level of fuel dilution. Test results indicated that the higher the torque at the rated-power, the greater the level of fuel dilution. In a cyclic-load engine test simulating the customer drives of a target vehicle powered by the engine, the maximum level for fuel dilution was found to be up to 9%, causing significant drop in the oil viscosity. The causes for fuel dilution and impacts of it on the oil consumption and formation of carbon deports on the piston ring area, and methods for mitigating impacts of fuel dilution are discussed in the paper. Copyright © 2015 SAE International.

Luo X.,JiangLing Motors Co. | Teng H.,JiangLing Motors Co. | Hu T.,JiangLing Motors Co. | Miao R.,JiangLing Motors Co. | Cao L.,JiangLing Motors Co.
SAE International Journal of Engines | Year: 2015

The biggest challenge in developing Turbocharged Gasoline Direct Injection (TGDI) engines may be the abnormal combustion phenomenon occurring at low speeds and high loads, known as low-speed pre-ignition (LSPI). LSPI can trigger severe engine knocks with intensities much greater than those of spark knocks and thus characterized as super knocks. In this study, behavior and patterns of LSPI were investigated experimentally with a highly-boosted 1.5L TGDI engine. It was found that LSPI could occur as an isolated event, a couple of events in sequence, or a trail of events. Although occurring randomly among the engine cylinders, LSPI took place frequently when the engine was operated at low speeds and high loads in the zone where scavenging was employed for boosting engine torques at low speeds, typically < 2500 rpm. Frequencies and patterns for LSPI were found to be influenced considerably by engine operation parameters, such as excess air coefficient, engine coolant temperature, valve timing, etc. Intensities of super knocks triggered by LSPI varied with the timing for the pre-ignition. Based on findings in this study, it was proposed that the oil particles as oil loading in the blowby recirculation could be the root cause for LSPI as they cause dirtiness of the combustion chamber roof where the oil particles could be attached and then initiate LSPI in the late compression stroke. It was demonstrated that although LSPI may not be eliminated due to the nature of the triggers, TGDI engines can be operated super-knock free through controlling conditions for combustion and engine cooling. As long as the values of the maximum peak firing pressure in LSPI events and their frequencies are under the design criteria, the engine can tolerate the LSPI events with acceptable knock intensities. Copyright © 2015 SAE International.

Zhao X.,Nanchang Hangkong University | Zhao X.,Jiang Ling Motors Corporation | Ke L.,Nanchang Hangkong University | Xu W.,Nanchang Hangkong University | Liu G.,Nanchang Hangkong University
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2011

In order to prepare composites with fine grains, uniform microstructure, and improving the mechanics performance significantly, different contents of carbon nanotubes (CNTs) reinforced aluminum matrix composites were prepared by friction stir processing (FSP). The microstructure, tensile properties and morphologies of tensile fracture surface were analyzed. The results show that CNTs are embedded in the aluminum matrix. The grain size is fine in the center of the friction stir zone. CNTs and matrix have a good combination. There are no obvious defects in the composites. CNTs improve the mechanics performance of the matrix. The tensile strength of aluminum matrix increases with the increasing of CNTs contents. The tensile strength reaches to 201 MPa when the volume fraction of CNTs is 7%, which is 2.2 times than that of matrix. The composites show the characteristics of brittle fracture at the macrostructure and plastic fracture at the microstructure. The fracture mechanism dominates by CNTs/Al interface debonding, matrix tearing and reinforced fiber fracturing.

Xiao Q.,East China Jiaotong University | Xiao Q.,Southwest University | Xu H.,Jiangling Motors Co. | Huang B.,East China Jiaotong University | Zhang H.,East China Jiaotong University
Zhongguo Tiedao Kexue/China Railway Science | Year: 2014

On the basis of wheel-rail rolling contact theory and by using the method of mixed Lagrangian/Eulerian with nonlinear finite element software ABAQUS, the large-scale finite element model of wheel-rail steady-state rolling contact was established. The creep force and creepage of CRH2 EMU running on CHN60 rail straight line with the lateral displacement of wheelset ranging from 0 to 6 mm were analyzed. Results show that, the maximum resultant force of the longitudinal creep force within wheel contact patch is 24.4 times of the minimum value with the increase of wheelset lateral displacement. The total longitudinal creep force of train decreases rapidly and almost linearly, which indicates that the traction performance of train will be reduced with the increase of wheelset lateral displacement. The difference between the maximum and minimum resultant force of lateral creep force is about 42.4%, and the change is lower than that of the resultant force of longitudinal creep force. The total lateral creep force of left wheel and right wheel of train decreases with the increase of wheelset lateral displacement, accordingly, both the lateral stability and derailment coefficient of train are affected. The difference between the maximum and minimum longitudinal creepage is 124.8%. Comparing with the longitudinal creepage, the value of lateral creepage is very small and hardly changes with the lateral displacement of wheelset, so the lateral displacement has little effect on the lateral creepage.

Hu T.,Jiangling Motors Co. | Teng H.,STA Energy Technologies Ltd | Luo X.,Jiangling Motors Co. | Lu C.,Jiangling Motors Co. | Luo J.,Jiangling Motors Co.
SAE Technical Papers | Year: 2015

The relationship between fuel dilution of the crankcase oil and low-speed pre-ignition (LSPI) was studied experimentally with a highly-boosted 1.8L turbocharged gasoline direct injection (TGDI) engine fueled with RON93 gasoline. It was found that properties of oil particles entered the engine cylinder were affected significantly by fuel dilution. The gasoline content in the oil represents those with long carbon chain or heavy species in gasoline, with much lower boiling points and auto ignition temperatures than those for the undiluted engine oil. Thus, dilution of the engine oil by these gasoline species lowers the volatility and the minimum auto ignition temperature of the engine oil. With 15% fuel content in the oil, the flash point and the fire point of the SAE 5W30 oil dropped from 245°C to 90°C and from 265°C to 150°C, respectively. The initial boiling point for the diluted oil could be lower than the wall temperatures for some locations on the combustion chamber roof or on the cylinder wall above the top piston ring reverse location. Once attached onto these hot areas, the oil particles entering the engine cylinder could form self-ignitable gaseous mixture easily, and become self ignited in late of the compression stroke under high loads, triggering pre-ignition. It was demonstrated that frequency of LSPI is linked strongly to the minimum auto ignition temperature of the oil particles. © Copyright 2015 SAE International.

Xu W.,Nanchang Hangkong University | Ke L.,Nanchang Hangkong University | Xing L.,Nanchang Hangkong University | Zhao X.,Jiangling Motors Corporation Ltd.
Materialwissenschaft und Werkstofftechnik | Year: 2011

The friction stir process (FSP) can be used to prepare carbon nanotubes (CNTs) forming reinforced Al matrix composites. The effect of CNTs content on the wear behaviour and hardness of aluminium based composites was studied. Adding CNTs effectively strengthens the matrix, and significantly improves the hardness of the composites. Composite wear test results showed that the addition of CNTs could enhance the wear resistance of the matrix. With increasing CNTs content, the wear resistance of the matrix markedly improved. The wear curve of the materials is a smooth curve. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Luo X.,Jiangling Motors Co. | Teng H.,Jiangling Motors Co. | Hu T.,Jiangling Motors Co. | Miao R.,Jiangling Motors Co. | Cao L.,Jiangling Motors Co.
SAE Technical Papers | Year: 2015

Turbocharged gasoline direct injection (TGDI) engines can achieve a very high level of brake mean effective pressure and thus the engines can be downsized. The biggest challenge in developing highly-boosted TGDI engines may be how to mitigate the pre-ignition (PI) triggered severe engine knocks at high loads and low engine speeds. Since magnitudes of cylinder pressure fluctuations during aforementioned engine knocks reach those for peak firing pressures in normal combustion, they are characterized as super knocks. It is widely believed that the root cause for super knocks is the oil particles entering the engine cylinder, which pre-ignite the cylinder mixture in late of the compression stroke. It is neither possible nor practical to completely eliminate the oil particles from the engine cylinder; a reasonable approach to mitigate super knocks is to weaken the conditions favoring super knocks. This paper reports the results of an experimental investigation on the conditions that potentially lead to PI and methods to suppress super knocks. Various parameters that could affect engine combustion were studied. It was found that intensities of super knocks varied considerably with the air-fuel ratio for the mixture, the engine cooling temperature, and volatility of the crankcase oil. It was demonstrated that through an appropriate control of the engine operation parameters, the TGDI engine can be operated super-knock free. Copyright © 2015 SAE International and Copyright © 2015 TSAE.

Loading JiangLing Motors Co. collaborators
Loading JiangLing Motors Co. collaborators