1995 Vol.8(4)
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1995, 9(4).
Abstract:
The theory of shared control combines organically the control of every controlled elements and with it all the controlled elements share the same control element. Applying the schemes of shared control searched by assembly programs, an integrated control of all the elements is fulfilled. The distinguishing point of the method is that the maximum control output can be obtained with the least input information. Hence it is the optimum for the conversion of combination states. Finally, a shared rotary valve is designed, and it is the simplest with only one group of cintrol holes.
The theory of shared control combines organically the control of every controlled elements and with it all the controlled elements share the same control element. Applying the schemes of shared control searched by assembly programs, an integrated control of all the elements is fulfilled. The distinguishing point of the method is that the maximum control output can be obtained with the least input information. Hence it is the optimum for the conversion of combination states. Finally, a shared rotary valve is designed, and it is the simplest with only one group of cintrol holes.
1995, 9(4).
Abstract:
Based upon the methods for the calculation of load capacity of involute cylindrical gears (ISO/DIS6336), the new method system that can be adapted for applying condition is found by applying regression analysis and stochastic time series analysis to the prediction of pitting life for the gears, the function is established between pitting area and revolving period of gear, the theoretical model is advanced for prediction the pitting fatigue life of gear, the problem is solved for obtaining the applying model by establishing the residue model, the method is put forward the model about predicting pitting fatigue life of gear with damaged condition under middle/low speed and heavy duty.
Based upon the methods for the calculation of load capacity of involute cylindrical gears (ISO/DIS6336), the new method system that can be adapted for applying condition is found by applying regression analysis and stochastic time series analysis to the prediction of pitting life for the gears, the function is established between pitting area and revolving period of gear, the theoretical model is advanced for prediction the pitting fatigue life of gear, the problem is solved for obtaining the applying model by establishing the residue model, the method is put forward the model about predicting pitting fatigue life of gear with damaged condition under middle/low speed and heavy duty.
1995, 9(4).
Abstract:
The transient viscosity response of a lubricant following the pressure change in a EHD contact is considered in the line-contact isothermal elastohydrodynamic lubrication analysed. So obtained pressure distribution and the oil film thichness are different from those obtained with equilibrium viscosity.
The transient viscosity response of a lubricant following the pressure change in a EHD contact is considered in the line-contact isothermal elastohydrodynamic lubrication analysed. So obtained pressure distribution and the oil film thichness are different from those obtained with equilibrium viscosity.
1995, 9(4).
Abstract:
By using dropped stress creep method a new testing technique for measurement of the fatigue-creep interaction resistance is developed. At varied adjusted mean stresses the creep testing was performed repeatedly. When an unlimited extensive incubation period with zero creep rate occurred, the stress causing zero creep rate is defined as fatigue-creep resistance. The developped testing technique was used to measure the fatigue-creep resistance in F and C regions. The dynamic effective stress could yield a better description of fatigue and creep interaction. The fatigue-creep rate equations with varied exponents in F or C region are established. The different deformation mechanisms in F or C regions are indicated.
By using dropped stress creep method a new testing technique for measurement of the fatigue-creep interaction resistance is developed. At varied adjusted mean stresses the creep testing was performed repeatedly. When an unlimited extensive incubation period with zero creep rate occurred, the stress causing zero creep rate is defined as fatigue-creep resistance. The developped testing technique was used to measure the fatigue-creep resistance in F and C regions. The dynamic effective stress could yield a better description of fatigue and creep interaction. The fatigue-creep rate equations with varied exponents in F or C region are established. The different deformation mechanisms in F or C regions are indicated.
1995, 9(4).
Abstract:
The formula for the engaging curve of the pinion cutter with pinoion and the formula for the theoretical tooth profile of the pinion cutter for the generating gearing of pinholes are developed based on the engaging theory. The substitute curve of the theoretical tooth profile of the pinion cutter is determined by the least square method.
The formula for the engaging curve of the pinion cutter with pinoion and the formula for the theoretical tooth profile of the pinion cutter for the generating gearing of pinholes are developed based on the engaging theory. The substitute curve of the theoretical tooth profile of the pinion cutter is determined by the least square method.
1995, 9(4).
Abstract:
The key techniques of modular design of heavy duty NC machine tools are described. A module definition model for modular design and manufacturing of heavy duty NC machine tools is bulit and the essential composition of the module definition model (MDM) is discussed in detail. It is composed of two model: the part definition model (MDM) is composed of two models: the part definition model (PDM) and the module assembly model (MAM). The PDM and MAM are built and their structrues are given. Using object-oriented knowledge representation and based on these models, and intelligent support system of modular design for geavy duty NC machine tools is developed and implemented. This system has been aapplied to the practical use of Wuhan Heavy Duty Machine Tool Works.
The key techniques of modular design of heavy duty NC machine tools are described. A module definition model for modular design and manufacturing of heavy duty NC machine tools is bulit and the essential composition of the module definition model (MDM) is discussed in detail. It is composed of two model: the part definition model (MDM) is composed of two models: the part definition model (PDM) and the module assembly model (MAM). The PDM and MAM are built and their structrues are given. Using object-oriented knowledge representation and based on these models, and intelligent support system of modular design for geavy duty NC machine tools is developed and implemented. This system has been aapplied to the practical use of Wuhan Heavy Duty Machine Tool Works.
1995, 9(4).
Abstract:
The performances of mixed ceramic and sialon ceramic tools in machining nickel based alloy are tested. The negative cutting edge inclination and small tool lead angle are recommended for reducing ceramic tool failure. So called "notching at depth of cut" is not actually at the depth of cutting line, but out of cutting area. The real reason of notching is caused by shocking of "sawtooth" on sawtooth-shaped burr and fin-shaped edges of chip.
The performances of mixed ceramic and sialon ceramic tools in machining nickel based alloy are tested. The negative cutting edge inclination and small tool lead angle are recommended for reducing ceramic tool failure. So called "notching at depth of cut" is not actually at the depth of cutting line, but out of cutting area. The real reason of notching is caused by shocking of "sawtooth" on sawtooth-shaped burr and fin-shaped edges of chip.
PREDICTION OF PUMP CHARACTERISTICS ACCORDING TO GEOMETRICAL PARAMETERS OF IMPELLER AND VOLUTE CASING
1995, 9(4).
Abstract:
The geometrical parameters of impeller or volute casing (including guide vane of multistage pump) have a great effect on pump characteristics, but ultimately, the pump characteristics are determined by the geometrical parameters of impeller and volute casing cooperatively. In this essay, the effect of impeller and volute casing on pump characteristics will be studied quantiatively from the angle of optimal matching of them.
The geometrical parameters of impeller or volute casing (including guide vane of multistage pump) have a great effect on pump characteristics, but ultimately, the pump characteristics are determined by the geometrical parameters of impeller and volute casing cooperatively. In this essay, the effect of impeller and volute casing on pump characteristics will be studied quantiatively from the angle of optimal matching of them.
1995, 9(4).
Abstract:
The cold box plus process is discussed in principle. When the proper heating to the core box is given (65℃±2℃), the binder lever can be saved, also the core strength and surface hardness are improved, the moisture-sensitivity is reduced. The mechanism of the cold box plus process is that the proper heat increases the activity of resin function groups and promotes the crosslinking reaction. The result of a scanning electron microscope analysis shows that the core surface strength is improved by heat.
The cold box plus process is discussed in principle. When the proper heating to the core box is given (65℃±2℃), the binder lever can be saved, also the core strength and surface hardness are improved, the moisture-sensitivity is reduced. The mechanism of the cold box plus process is that the proper heat increases the activity of resin function groups and promotes the crosslinking reaction. The result of a scanning electron microscope analysis shows that the core surface strength is improved by heat.
1995, 9(4).
Abstract:
Taking double-die ironing for example, the plastic deformation behavior of the workpiece in multidie ironing process is analysed by the rigid-plastic finite element method (RPFEM). Considering the strain hardening of the material, the distributions of the effective strain rate and hydrostatic stress are obtained. Calculated results and the effect of die angles on the deformation and ironing force are discussed. The comparison of calculated results with those of experiment shows a good agreement.
Taking double-die ironing for example, the plastic deformation behavior of the workpiece in multidie ironing process is analysed by the rigid-plastic finite element method (RPFEM). Considering the strain hardening of the material, the distributions of the effective strain rate and hydrostatic stress are obtained. Calculated results and the effect of die angles on the deformation and ironing force are discussed. The comparison of calculated results with those of experiment shows a good agreement.
1995, 9(4).
Abstract:
A new view of characteristic zone classification of fusion welding joint has been put forward on the base of a number of metallograpic observations and researches. The characteristic zones of the joint inculde(1) homogenous mixture region, (2) heterogenous mixture zone, (3) partically melting zone, and (4) heat-affected zone. (1) and (2) consist of the weld metal, (2) and (3) compose the bond, the boundary between (2) and (3) is the fusion line. Four kinds of characteristic appearences in the "heterogenous mixture zone" are induced. The formation process of the Savage's one are compared, to hoping that the formation essence and composition feature of fusion welding joint can be reasonably reflected.
A new view of characteristic zone classification of fusion welding joint has been put forward on the base of a number of metallograpic observations and researches. The characteristic zones of the joint inculde(1) homogenous mixture region, (2) heterogenous mixture zone, (3) partically melting zone, and (4) heat-affected zone. (1) and (2) consist of the weld metal, (2) and (3) compose the bond, the boundary between (2) and (3) is the fusion line. Four kinds of characteristic appearences in the "heterogenous mixture zone" are induced. The formation process of the Savage's one are compared, to hoping that the formation essence and composition feature of fusion welding joint can be reasonably reflected.
1995, 9(4).
Abstract:
On the basis of study on the mathematical model of 3-dimensional ruled surface (RS), this paper introduces a new cincept of distance parameter (DP) and also puts forward that the method of modeling a RS depends on not only two boundary curves but also DP. According to above theory, the formulas to calculate corresponding point coordinates to any kind of top and bottom profile of a workpiece and formulas to calculate the maximum inclination angle of ruling line have been obtained. Then a different top and bottom RS machining method including profile with line-are combination as well as parametric curves has been achieved by 4-axes simulatneous control programming proposed.
On the basis of study on the mathematical model of 3-dimensional ruled surface (RS), this paper introduces a new cincept of distance parameter (DP) and also puts forward that the method of modeling a RS depends on not only two boundary curves but also DP. According to above theory, the formulas to calculate corresponding point coordinates to any kind of top and bottom profile of a workpiece and formulas to calculate the maximum inclination angle of ruling line have been obtained. Then a different top and bottom RS machining method including profile with line-are combination as well as parametric curves has been achieved by 4-axes simulatneous control programming proposed.
1995, 9(4).
Abstract:
The speeds of output shaft of a machine tool nj=niψE are expressed by the exponent values Ej of series ratio ψ. Based on this expression, the inherent law of differences between exponents of driven points from the same drive pair and the same driving point and of corresponding driving points. A method for finding out the exponents of the range ratio has been given according to the law and it is called coordinate diagram method. Finally, a mathematical model is constructed and a computer programme is designed.
The speeds of output shaft of a machine tool nj=niψE are expressed by the exponent values Ej of series ratio ψ. Based on this expression, the inherent law of differences between exponents of driven points from the same drive pair and the same driving point and of corresponding driving points. A method for finding out the exponents of the range ratio has been given according to the law and it is called coordinate diagram method. Finally, a mathematical model is constructed and a computer programme is designed.
1995, 9(4).
Abstract:
A ceramic rocker arm is proposed. Thst for ICE performance and numerical analysis of valve system were earried out. The results show that ceramic rocker arm can replace ordinary steel ones and meet the requiements of ICE practical operation, and reduce both the wear between contact surface and the vibration of valve system.
A ceramic rocker arm is proposed. Thst for ICE performance and numerical analysis of valve system were earried out. The results show that ceramic rocker arm can replace ordinary steel ones and meet the requiements of ICE practical operation, and reduce both the wear between contact surface and the vibration of valve system.
1995, 9(4).
Abstract:
The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply. The tooth surface equation of EBCBG manufactured by end milling cutter with involute profile is derived. The tooth form error is analyzed on the basis of spherical involute.
The basic principle of equal base circle bevel gear (EBCBG) is illustrated simply. The tooth surface equation of EBCBG manufactured by end milling cutter with involute profile is derived. The tooth form error is analyzed on the basis of spherical involute.
1995, 9(4).
Abstract:
Sequential melting theory is applied to reveal that fluctuation of chemical composition of melted iron in cupola is caused by the process of sequential melting. Fluctuation is inevitable and cyclic. Using microcomputer dynamic simulation has confirmed that the fluctuation situation of chemical composition of melted iron is consistent with actual production on the whole.
Sequential melting theory is applied to reveal that fluctuation of chemical composition of melted iron in cupola is caused by the process of sequential melting. Fluctuation is inevitable and cyclic. Using microcomputer dynamic simulation has confirmed that the fluctuation situation of chemical composition of melted iron is consistent with actual production on the whole.
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