CN102323063B - Method for testing oil-film force of piston assembly based on crankshaft vibration signal and system - Google Patents

Abstract

The invention discloses a method for testing the oil-film force of a piston assembly based on a crankshaft vibration signal. By using an offline emulation module of lubrication mechanics and dynamics equations of each component in an established piston-shaft system, the oil-film force (friction force and bearing force) of an internal combustion engine piston assembly can be obtained on line through a crankshaft vibration signal; the strong coupling of the lubrication mechanics and dynamics of each component in the piston-shaft system is considered comprehensively, and a new two-dimensional hybrid lubrication model is used, so that the online prediction operability of the oil-film force is enhanced, the two-dimensional oil-film force (circumferential and axial) of the internal combustion engine piston assembly can be obtained accurately simultaneously, and the problem of low accuracy of the oil-film force of the internal combustion engine piston assembly obtained with the conventional method is solved; and the oil-film force of the internal combustion engine piston assembly can be safely, reliably and accurately obtained on line by using each module of the system, a computer and a sensor in an online test analysis device, and the oil-film force obtaining cost is saved remarkably.

Description

Piston component oil-film force method of testing and system based on the crankshaft vibration signal

Technical field

The present invention relates to the oil-film force field tests, particularly a kind of on-line testing method of the piston component oil-film force based on the crankshaft vibration signal also relates to a kind of piston component oil-film force Online Transaction Processing by the crankshaft vibration signal simultaneously.

Background technology

The history in existing more than 100 year of the use of internal combustion engine becomes the widest propulsion system of range of application.The piston of internal combustion engine-axle system (comprising piston ring, piston, connecting rod, crank and bent axle) is the core institution system of internal combustion engine transferring power, also is the main source of power loss simultaneously, and the quality of its performance directly affects efficient and the life-span of complete machine.The utilization of internal combustion engine practice shows that piston-axle is the disabler of each parts, usually is Internal-Combustion Engine Maintenance and the main reason of scrapping.It is estimated that only in China, the loss that annual all kinds of internal combustion engines bring because of friction problem is up to over ten billion Yuan.Concerning all internal combustion engines, piston component oil-film force (friction force and bearing capacity) is directly connected to friction power loss and the serviceable life of internal combustion engine complete machine.Because internal combustion engine is a very complicated system, and the restriction of current Measurement and Computation condition, it is very difficult that accurate description internal combustion engine assembly oil-film force seems.Therefore, the obtaining of further investigation internal combustion engine assembly oil-film force, to design, the maintenance of internal-combustion engines, improve its operational efficiency and the life-span significant.

Obtain problem for solving internal combustion engine assembly oil-film force, once occurred putting perforate at cylinder of internal-combustion engine, then by the method for sensor measurement piston component oil-film force, but because perforate has caused the leakage of cylinder combustion gas and lubricating oil, and the impact such as Vibration Cylinder Body, this has caused the accuracy of measurement of piston component oil-film force to be had a greatly reduced quality, so this method seldom adopts in practice.

The method of piston component oil-film force has further appearred predicting with computing technique.Yet these methods or isolated study the lubricated mechanical property that piston-axle is each parts, or isolated study the dynamic performance that piston-axle is each parts, be each component lubrication mechanics and dynamic (dynamical) strong coupling characteristic and ignore piston-axle.And the various factors in the employed mixed lubrication equation in these researchs, be only applicable to the piston component rough surface of desirable Gaussian, do not consider elastic deformation that these are surperficial and the cavitation of lubricant simultaneously yet.In addition, the one dimension lubrication model has been used in overwhelming majority research, only can obtain circumferential or axial oil-film force.Above-mentioned reason causes the oil-film force of predicting the piston component that obtains by the computer technology of routine, often differs larger with its actual measured value.Because the analysis time of this method is long, be difficult to online use simultaneously.

Therefore, need a kind of new method of testing the piston component oil-film force, namely do not destroy the integrality of IC engine cylinder block, measure the piston component oil-film force to accuracy online again simultaneously, and simple, highly versatile.

Summary of the invention

In view of this, one of purpose of the present invention provides a kind of piston component oil-film force method of testing based on the crankshaft vibration signal, the method is mainly utilized the vibration signal on the bent axle, can determine the oil-film force of piston component, thereby simplified the test of piston component oil-film force, characteristics with measurement accuracy height and highly versatile, and can use online; Two of purpose of the present invention provides a kind of piston component oil-film force test macro based on the crankshaft vibration signal.

One of purpose of the present invention is achieved through the following technical solutions:

Should based on the piston component oil-film force method of testing of crankshaft vibration signal, may further comprise the steps:

1) set following parameter:

A. gaseous-pressure, the engine speed in the cylinder of internal-combustion engine;

B. the number of piston ring, physical dimension and quality;

C. the physical dimension of piston and quality;

D. the physical dimension of connecting rod and crank, moment of inertia, centroid position and quality;

E. the physical dimension of bent axle, moment of inertia, centroid position and quality;

F. the viscosity of lubricant, density and comprehensive roughness;

2) adopting piston-axle is the mixed lubrication equation of each parts and the Coupling Design of kinetics equation, obtains acting on the vibration displacement on the bent axle under the different operating modes of internal combustion engine;

3) with step 2) the crankshaft vibration signal that obtains is through neural network input and output relationship analysis, obtains online the two-dimentional oil-film force of piston and rings.

Further, described two-dimentional mixed lubrication equation is:

Described two-dimentional mixed lubrication equation is:

$\frac{\&PartialD;}{\&PartialD;x}\left({\mathrm{\&phi;}}_{\mathrm{<figure-callout\; id="3"\; label="x\; h"\; filenames="HDA0000064791880000011.png"\; state="\{\{state\}\}">x</figure-callout>}}\frac{h^{}}{}\frac{{}^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;x}\right)+\frac{\&PartialD;}{\&PartialD;y}\left({\mathrm{\&phi;}}_y\frac{{\mathrm{<figure-callout\; id="3"\; label="h"\; filenames="HDA0000064791880000011.png"\; state="\{\{state\}\}">h</figure-callout>}}^3}{12u}\frac{\&PartialD;p}{\&PartialD;y}\right)=6U{\mathrm{\&phi;}}_c\frac{\&PartialD;h}{\&PartialD;x}+6\mathrm{U\&sigma;}\frac{\&PartialD;{\mathrm{\&phi;}}_s}{\&PartialD;x}+{\mathrm{\&phi;}}_c\frac{\&PartialD;h}{\&PartialD;t},---\left(1\right)$

In the following formula, μ is lubricant viscosity, and p is lubricant pressure, and h is oil film thickness, and x is the circumferencial direction coordinate, and y is axial coordinate, the pressure flow factor φ of x direction _x, the oil film thickness direction pressure φ _y, and shear flow factor φ _sElastic deformation and cavitation have been considered, the contact factor φ that redefines _cCan be used for dissimilar surfaces, σ is comprehensive roughness, and U is the movement velocity of piston ring/piston or bent axle; In the above parameter, p is obtained by above-mentioned two-dimentional mixed lubrication equation according to the parameter of setting, and μ sets φ in advance _x, φ _y, φ _sAnd φ _cCalculate according to σ, U determines according to the engine speed of setting, and h determines during to be the coupling of mixed lubrication equation and kinetics equation calculate automatically.

Further, described kinetics equation comprises the force and moment equation between each parts, and each equation is:

1. piston mechanical equation

Piston at the mechanical equation of x and y direction is:

In formula (2): piston mass is m _pThe power that connecting rod acts on piston is respectively-F at the component of x and y direction _RpxWith-F _RpyOil film action is respectively F in the power of piston at the component of x and y direction _OpxAnd F _Opy, F wherein _OpyThat piston is in the bearing capacity of y direction oil film and making a concerted effort of piston swing; Piston is r in the displacement of x direction ₁, speed is

Acceleration is

Piston is r in the displacement of y direction ₂, its speed is

Acceleration is

F _gBe the acting force of combustion gas in the cylinder to piston.

2. connecting rod mechanical equation

Connecting rod at the mechanical equation of x and y direction is:

$\left.\begin{array}{c}-F_{\mathrm{rcx}}+F_{\mathrm{rpx}}=m_r{a}_{\mathrm{rx}}\\ -F_{\mathrm{rcy}}+F_{\mathrm{rpy}}=m_r{a}_{\mathrm{ry}}\end{array}\right\},---\left(3\right)$

Moment to barycenter d is:

F _rpx(L _r-r _r)sinθ _r+F _rpy(L _r-r _r)cosθ _r-F _rcxr _rsinθ _r-F _rcyr _rcosθ _r＝I _rα _r ，(4)

In formula (3) and formula (4): connecting rod quality is m _r, its moment of inertia is I _r, length is L _r, barycenter to crank movable end distance is r _r, the barycenter acceleration is respectively a at x and y direction _RxAnd a _Ry, it is θ with axial angle _r, rotational angular velocity is α _rThe power that crank acts on connecting rod is respectively-F at the component of x and y direction _RcxWith-F _RcyPiston action is respectively F in the power of crank at the component of x and y direction _RpxAnd F _Rpy

3. crank mechanical equation

$\left.\begin{array}{c}-F_{\mathrm{mcx}}+F_{\mathrm{rcx}}=m_c{a}_{\mathrm{cx}}\\ -F_{\mathrm{mcy}}+F_{\mathrm{rcy}}=m_c{a}_{\mathrm{cy}}\end{array}\right\},---\left(5\right)$

Moment to centre of gyration o is:

-F _rcxR _csinθ _c+F _rcyR _ccosθ _c+M _c＝I _cα _c，(6)

In formula (5) and formula (6): the crank quality is m _c, its moment of inertia is I _c, length is R _c, barycenter b acceleration is respectively a at x and y direction _CxAnd a _Cy, it is θ with axial angle _c, crank angle of rotation acceleration is α _c, its suffered rotating torque is M _cThe power that bent axle acts on crank is respectively F at the component of x and y direction _McxAnd F _McyThe power that connecting rod acts on crank is respectively F at the component of x and y direction _RcxAnd F _Rcy

4. crankshaft lubrication mechanical equation

Use equation (1) to calculate;

5. crankshaft vibration equation

Bent axle at the vibration equation of x and y direction is:

In formula (7): the bent axle quality is M, and C is the crankshaft vibration damping, and K is crankshaft vibration rigidity, F _x(t) and F _y(t) be respectively stressed in x and y direction of bent axle, namely-F _McxOr-F _Mcy

Two of purpose of the present invention is achieved through the following technical solutions:

Should based on the piston component oil-film force test macro of crankshaft vibration signal, comprise off-line simulation device and on-line testing analytical equipment;

Described off-line simulation device comprises:

Cylinder combustion pressure acquisition module is used for record cylinder combustion pressure;

Piston ring/piston oil-film force analysis module according to the correlation parameter of input, is used for analyzing the oil-film force of piston ring and piston;

The oil-film force data base access module is used for the access oil-film force and analyzes data;

The neural training module of oil-film force is used for that the oil-film force of oil-film force data base access module output is analyzed data and carries out neural metwork training, obtains the oil-film force after training;

The link motion analog module is used for receiving the oil-film force data after training, obtains link motion data and output after simulation;

The crank-motion analog module is used for receiving the exercise data that the link motion analog module is exported, and obtains crank-motion data and output after simulation;

Crankshaft lubrication mechanical analysis module is used for receiving the crank-motion data of crank-motion analog module output, and through bent axle is lubricated mechanics property analysis, obtains crankshaft lubrication mechanics related data;

The crankshaft vibration analysis module is used for receiving aforesaid crank-motion data and crankshaft lubrication mechanics related data and to above-mentioned data analysis, obtains the crankshaft vibration signal under different working conditions;

Described on-line testing analytical equipment comprises:

The crankshaft vibration signal acquisition module is used for obtaining the crankshaft vibration signal under the aforesaid different working condition;

Crankshaft vibration signal analysis of neural network module is used for the crankshaft vibration signal that obtains is carried out neural network input and output relationship analysis;

Oil-film force on-line prediction module is used for the related data that obtains through analysis of neural network is processed, and obtains the two-dimentional oil-film force data of piston ring and piston.

The invention has the beneficial effects as follows:

1. oil-film force method of testing of the present invention, utilizing piston-axle is the strong coupling design of lubricated mechanical equation and the kinetics equation of each parts, has used new two-dimentional mixed lubrication equation, can carry out the on-line testing of piston component two dimension oil-film force; Because pressure flow factor, shear flow factor and contact factor in the employed mixed lubrication equation have comprised surperficial elastic deformation and the cavitation of lubricant, and can be fit to the surface that various types of piston-axles are each parts, and taken into full account tribology and dynamic (dynamical) strong coupling effect between each parts, thereby the two-dimentional oil-film force that piston component is obtained approaches more actual;

2. of the present invention owing to adopt artificial neural network module prediction oil-film force, the piston component oil-film force numerical evaluation of replacement transmission has significantly reduced the oil-film force acquisition time;

3. the present invention only utilizes the crankshaft vibration signal can calculate the piston component oil-film force, compares conveniently and economical with the internal combustion engine oil film method of testing of transmission, and fault that simultaneously also can the on-line prediction piston component is in order in time take to suppress the measure that fault occurs.

Other advantages of the present invention, target and feature will be set forth to a certain extent in the following description, and to a certain extent, based on being apparent to those skilled in the art to investigating hereinafter, perhaps can obtain from the practice of the present invention instruction.Target of the present invention and other advantages can realize and obtain by following instructions and claims.

Description of drawings

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with accompanying drawing, wherein:

Fig. 1 is the connection diagram of each module of off-line simulation device;

Fig. 2 is the connection diagram of each module of on-line testing analytical equipment;

Fig. 3 be among the embodiment when engine speed is 1500rpm, obtain bent axle length travel synoptic diagram by off-line simulation device and experiment;

Fig. 4 be among the embodiment when engine speed is 1500rpm, obtain bent axle transversal displacement synoptic diagram by off-line simulation device and experiment;

Fig. 5 be among the embodiment when engine speed is 1000rpm, the piston component oil-film force that is obtained by on-line testing analytical equipment and experiment is synoptic diagram relatively.

Embodiment

Hereinafter with reference to accompanying drawing, the preferred embodiments of the present invention are described in detail.Should be appreciated that preferred embodiment only for the present invention is described, rather than in order to limit protection scope of the present invention.

Should based on the piston component oil-film force test macro of crankshaft vibration signal, comprise off-line simulation device and on-line testing analytical equipment;

As shown in Figure 1, described off-line simulation device comprises cylinder combustion pressure acquisition module 1, piston ring/piston oil-film force analysis module 2, oil-film force data base access module 3, the neural training module 4 of oil-film force, link motion analog module 5, crank-motion analog module 6, crankshaft lubrication mechanical analysis module 7 and crankshaft vibration analysis module 8:

Wherein, the effect of each module is as follows:

Cylinder combustion pressure acquisition module 1 is used for record cylinder combustion pressure;

Piston ring/piston oil-film force analysis module 2 according to the correlation parameter of input, is used for analyzing the oil-film force of piston ring and piston;

Oil-film force data base access module 3 is used for the access oil-film force and analyzes data;

The neural training module 4 of oil-film force is used for that the oil-film force of oil-film force data base access module output is analyzed data and carries out neural metwork training, obtains the oil-film force after training;

Link motion analog module 5 is used for receiving the oil-film force data after training, obtains link motion data and output after simulation;

Crank-motion analog module 6 is used for receiving the exercise data that the link motion analog module is exported, and obtains crank-motion data and output after simulation;

Crankshaft lubrication mechanical analysis module 7 is used for receiving the crank-motion data of crank-motion analog module output, and through bent axle is lubricated mechanics property analysis, obtains crankshaft lubrication mechanics related data;

Crankshaft vibration analysis module 8 is used for receiving aforesaid link motion data, crank-motion data and crankshaft lubrication mechanics related data and to above-mentioned data analysis, obtaining the crankshaft vibration signal under different working conditions;

When the oil-film force off-line simulation is analyzed, obtained the cylinder combustion atmospheric pressure that changes with internal-combustion engine rotational speed by cylinder combustion pressure acquisition module 1, analyze and obtain piston ring and piston oil-film force through piston ring/piston oil-film force analysis module 2, these data deposit in the oil-film force data base access module 3.Further, oil-film force data in the oil-film force data base access module 3 are taken out the input as the neural training module 4 of oil-film force, oil-film force data after can obtaining training behind the neural metwork training by the neural training module 4 of oil-film force, next, these oil-film force data of being trained are as the input of link motion analog module 5, crank-motion analog module 6, crankshaft lubrication mechanical analysis module 7, through module 5,6 and 7 analyzing and processing, just can obtain the vibration signal of the bent axle under the different operating modes.

As shown in Figure 2, the on-line testing analytical equipment comprises crankshaft vibration signal acquisition module 9, crankshaft vibration signal analysis of neural network module 10 and oil-film force on-line prediction module 11:

Crankshaft vibration signal acquisition module 9 is used for obtaining the crankshaft vibration signal under the aforesaid different working condition;

Crankshaft vibration signal analysis of neural network module 10 is used for the crankshaft vibration signal that obtains is carried out neural network input and output relationship analysis;

Oil-film force on-line prediction module 11 is used for the related data that obtains through analysis of neural network is processed, and obtains the two-dimentional oil-film force data of piston ring and piston.

Neural network is from Neuropsychology and cognitive science achievement in research, and a kind of parallel distributed mode treatment system that application of mathematical method grows up has highly-parallel computing power, self-learning ability and fault-tolerant ability.Nerual network technique has been showed the superiority that it is outstanding at aspects such as pattern recognition and classification, identification filtering, automatically control, predictions.The structure of neural network is comprised of an input layer, several middle hidden layers and an output layer.The analysis of neural network method can be found its rule by unceasing study from a large amount of complex data of unknown pattern.Neural net method has overcome the complicacy of traditional analysis process and has selected the difficulty of suitable pattern function form, and it is a kind of natural Nonlinear Modeling process, need not distinguish to have which kind of nonlinear relationship, brings great convenience for modeling and analysis.

Piston component oil-film force method of testing based on the crankshaft vibration signal of the present invention may further comprise the steps:

1) set following parameter:

A. gaseous-pressure, the engine speed in the cylinder of internal-combustion engine;

B. the number of piston ring, physical dimension and quality;

C. the physical dimension of piston and quality;

D. the physical dimension of connecting rod and crank, moment of inertia, centroid position and quality;

E. the physical dimension of bent axle, moment of inertia, centroid position and quality;

F. the viscosity of lubricant, density and comprehensive roughness;

2) adopting piston-axle is the two-dimentional mixed lubrication equation of each parts and the Coupling Design of kinetics equation, obtains acting on the vibration displacement on the bent axle under the different operating modes of internal combustion engine;

A. described two-dimentional mixed lubrication equation is:

$\frac{\&PartialD;}{\&PartialD;x}\left({\mathrm{\&phi;}}_{\mathrm{<figure-callout\; id="3"\; label="x\; h"\; filenames="HDA0000064791880000011.png"\; state="\{\{state\}\}">x</figure-callout>}}\frac{h^{}}{}\frac{{}^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;x}\right)+\frac{\&PartialD;}{\&PartialD;y}\left({\mathrm{\&phi;}}_{\mathrm{<figure-callout\; id="3"\; label="y\; h"\; filenames="HDA0000064791880000011.png"\; state="\{\{state\}\}">y</figure-callout>}}\frac{h^{}}{}\frac{{}^3}{12u}\frac{\&PartialD;p}{\&PartialD;y}\right)=6U{\mathrm{\&phi;}}_c\frac{\&PartialD;h}{\&PartialD;x}+6\mathrm{U\&sigma;}\frac{\&PartialD;{\mathrm{\&phi;}}_s}{\&PartialD;x}+{\mathrm{\&phi;}}_c\frac{\&PartialD;h}{\&PartialD;t}$

In the following formula, μ is lubricant viscosity, and p is lubricant pressure, and h is oil film thickness, and x is the circumferencial direction coordinate, and y is axial coordinate, the pressure flow factor φ of x direction _x, the oil film thickness direction pressure φ _y, and shear flow factor φ _sElastic deformation and cavitation have been considered, the contact factor φ that redefines _cCan be used for dissimilar surfaces, σ is comprehensive roughness, and U is the movement velocity of piston ring/piston or bent axle.In the above parameter, p is obtained by above-mentioned two-dimentional mixed lubrication equation according to the parameter of setting, and μ sets (particularly, be after having selected the lubricant that uses, can obtain by the characterisitic parameter of inquiring about this lubricant), φ in advance _x, φ _y, φ _sAnd φ _cCalculate according to σ, U determines according to the engine speed of setting, and h determines during to be the coupling of mixed lubrication equation and kinetics equation calculate automatically.

B. described kinetics equation comprises the force and moment equation between each parts, and each equation is:

(1) piston mechanical equation

Piston at the mechanical equation of x and y direction is:

Wherein: piston mass is m _pThe power that connecting rod acts on piston is respectively-F at the component of x and y direction _RpxWith-F _RpyOil film action is respectively F in the power of piston at the component of x and y direction _OpxAnd F _Opy, F wherein _OpyThat piston is in the bearing capacity of y direction oil film and making a concerted effort of piston swing; Piston is r in the displacement of x direction ₁, speed is

Acceleration is

Piston is r in the displacement of y direction ₂, its speed is Acceleration is

F _gBe the acting force of combustion gas in the cylinder to piston.

(2) connecting rod mechanical equation

Connecting rod at the mechanical equation of x and y direction is:

$\left.\begin{array}{c}-F_{\mathrm{rcx}}+F_{\mathrm{rpx}}=m_r{a}_{\mathrm{rx}}\\ -F_{\mathrm{rcy}}+F_{\mathrm{rpy}}=m_r{a}_{\mathrm{ry}}\end{array}\right\}$

Moment to barycenter d is:

F _rpx(L _r-r _r)sinθ _r+F _rpy(L _r-r _r)cosθ _r-F _rcxr _rsinθ _r-F _rcyr _rcosθ _r＝I _rα _r

In upper two formulas: connecting rod quality is m _r, its moment of inertia is I _r, length is L _r, barycenter to crank movable end distance is r _r, the barycenter acceleration is respectively a at x and y direction _RxAnd a _Ry, it is θ with axial angle _r, rotational angular velocity is α _rThe power that crank acts on connecting rod is respectively-F at the component of x and y direction _RcxWith-F _RcyPiston action is respectively F in the power of crank at the component of x and y direction _RpxAnd F _Rpy

(3) crank mechanical equation

$\left.\begin{array}{c}-F_{\mathrm{mcx}}+F_{\mathrm{rcx}}=m_c{a}_{\mathrm{cx}}\\ -F_{\mathrm{mcy}}+F_{\mathrm{rcy}}=m_c{a}_{\mathrm{cy}}\end{array}\right\}$

Moment to centre of gyration o is:

-F _rcxR _csinθ _c+F _rcyR _ccosθ _c+M _c＝I _cαx

In upper two formulas: the crank quality is m _c, its moment of inertia is I _c, length is R _c, barycenter b acceleration is respectively a at x and y direction _CxAnd a _Cy, it is θ with axial angle _c, crank angle of rotation acceleration is α _c, its suffered rotating torque is M _cThe power that bent axle acts on crank is respectively F at the component of x and y direction _McxAnd F _McyThe power that connecting rod acts on crank is respectively F at the component of x and y direction _RcxAnd F _Rcy

(4) crankshaft lubrication mechanical equation

The mixed lubrication equation that uses with piston is identical.

(5) crankshaft vibration equation

Bent axle at the vibration equation of x and y direction is:

Wherein: the axoplasm amount is M, and C is the crankshaft vibration damping, and K is crankshaft vibration rigidity, F _x(t) and F _y(t) be respectively stressed in x and y direction of bent axle, namely-F _McxOr-F _Mcy

3) with step 2) the crankshaft vibration signal that obtains is through neural network input and output relationship analysis, obtains online the two-dimentional oil-film force of piston and rings.

Embodiment

Take the DL190-12 engine as example, at first use the crankshaft vibration signal under the different working conditions of off-line simulation device.Be under the 1500rpm in engine speed, obtain cylinder combustion pressure by cylinder combustion pressure acquisition module; By piston ring/piston oil-film force analysis module, analyze the oil-film force of piston ring and piston according to the engine correlation parameter; Analyze data according to oil-film force data base access module access oil-film force; Obtain oil-film force after training by the neural training module of oil-film force; According to the oil-film force data of link motion analog module reception after training, after simulation, obtain link motion data and output again; Receive the exercise data that the link motion analog module is exported by the crank-motion analog module, after simulation, obtain crank-motion data and output; By crankshaft lubrication mechanical analysis module, be used for receiving the crank-motion data of crank-motion analog module output, and through bent axle is lubricated mechanics property analysis, obtain crankshaft lubrication mechanics related data; By the crankshaft vibration analysis module, be used for receiving aforesaid link motion data, crank-motion data and crankshaft lubrication mechanics related data and to above-mentioned data analysis, obtaining the crankshaft vibration signal under different working conditions again.When engine speed is 1500rpm, Fig. 3 and Fig. 4 are the bent axle vertical and horizontal displacements by using the off-line simulation device to obtain, can find out by the off-line simulation device obtain bent axle vertical/transversal displacement and actual record bent axle vertical/transversal displacement is very approaching, this has illustrated the validity of off-line simulation.

Further, the crankshaft vibration signal acquisition module in the use on-line testing analytical equipment obtains the bent axle on-line vibration signal under the different working conditions; Crankshaft vibration signal analysis of neural network module in the on-line testing analytical equipment, the crankshaft vibration signal that obtains, and carry out the analysis of neural network that input and output concern; Oil-film force on-line prediction module in the final online device for testing and analyzing is processed the related data that obtains through analysis of neural network, obtains the two-dimentional oil-film force data of piston ring and piston.When engine speed is 1000rpm, Fig. 5 has provided the horizontal and vertical displacement of bent axle of using the on-line testing analytical equipment to obtain, can find out by oil-film force on-line prediction module to obtain the piston component oil-film force and actual to record the piston component oil-film force very approaching, this has illustrated the validity of on-line testing analytical equipment design.

Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although with reference to preferred embodiment the present invention is had been described in detail, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement technical scheme of the present invention, and not breaking away from aim and the scope of the technical program, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (4)

1. based on the piston component oil-film force method of testing of crankshaft vibration signal, it is characterized in that: may further comprise the steps:

1) set following parameter:

A. gaseous-pressure, the engine speed in the cylinder of internal-combustion engine;

B. the number of piston ring, physical dimension and quality;

C. the physical dimension of piston and quality;

D. the physical dimension of connecting rod and crank, moment of inertia, centroid position and quality;

E. the physical dimension of bent axle, moment of inertia, centroid position and quality;

F. the viscosity of lubricant, density and comprehensive roughness;

2) adopting piston-axle is the two-dimentional mixed lubrication equation of each parts and the Coupling Design of kinetics equation, calculates by the crankshaft vibration equation in the kinetics equation and acts on the vibration displacement on the bent axle under the different operating modes of internal combustion engine;

3) utilize step 2) setup parameter and the vibration displacement relationship map pattern that obtain, the crankshaft vibration signal that actual measurement is obtained carries out neural network input and output relationship analysis, thereby obtains online the two-dimentional oil-film force of piston and rings.

2. the piston component oil-film force method of testing based on the crankshaft vibration signal according to claim 1, it is characterized in that: described two-dimentional mixed lubrication equation is:

$\frac{\&PartialD;}{\&PartialD;x}\left({\mathrm{\&phi;}}_x\frac{h^3}{12\mathrm{\&mu;}}\frac{\&PartialD;p}{\&PartialD;x}\right)+\frac{\&PartialD;}{\&PartialD;y}\left({\mathrm{\&phi;}}_y\frac{h^3}{12u}\frac{\&PartialD;p}{\&PartialD;y}\right)=6U{\mathrm{\&phi;}}_c\frac{\&PartialD;h}{\&PartialD;x}+6\mathrm{U\&sigma;}\frac{{\&PartialD;\mathrm{\&phi;}}_s}{\&PartialD;x}+{\mathrm{\&phi;}}_c\frac{\&PartialD;h}{\&PartialD;t},$

In the following formula, μ is lubricant viscosity, and p is lubricant pressure, and h is oil film thickness, and x is the circumferencial direction coordinate, and y is axial coordinate, the pressure flow factor φ of x direction _x, the oil film thickness direction pressure φ _y, and shear flow factor φ _sElastic deformation and cavitation have been considered, the contact factor φ that redefines _cCan be used for dissimilar surfaces, σ is comprehensive roughness, and U is the movement velocity of piston ring/piston or bent axle; In the above parameter, p is obtained by above-mentioned two-dimentional mixed lubrication equation according to the parameter of setting, and μ sets φ in advance _x, φ _y, φ _sAnd φ _cCalculate according to σ, U determines according to the engine speed of setting, and h determines during to be the coupling of mixed lubrication equation and kinetics equation calculate automatically.

3. the piston component oil-film force method of testing based on the crankshaft vibration signal according to claim 1, it is characterized in that: described kinetics equation comprises the force and moment equation between each parts, and each equation is:

(1) piston mechanical equation

Piston at the mechanical equation of x and y direction is:

$\left.\begin{array}{c}-F_{\mathrm{rpx}}+F_g+F_{\mathrm{opx}}=m_p{\stackrel{\&CenterDot;\&CenterDot;}{r}}_1\\ -F_{\mathrm{rpy}}+F_{\mathrm{opy}}=m_p{\stackrel{\&CenterDot;\&CenterDot;}{r}}_2\end{array}\right\},$

Wherein: piston mass is m _pThe power that connecting rod acts on piston is respectively-F at the component of x and y direction _RpxWith-F _RpyOil film action is respectively F in the power of piston at the component of x and y direction _OpxAnd F _Opy, F wherein _OpyThat piston is in the bearing capacity of y direction oil film and making a concerted effort of piston swing; Piston is r in the displacement of x direction ₁, speed is

Acceleration is

Piston is r in the displacement of y direction ₂, its speed is

Acceleration is

F _gBe the acting force of combustion gas in the cylinder to piston;

(2) connecting rod mechanical equation

Connecting rod at the mechanical equation of x and y direction is:

$\left.\begin{array}{c}{-F}_{\mathrm{rcx}}+F_{\mathrm{rpx}}=m_r{a}_{\mathrm{rx}}\\ {-F}_{\mathrm{rcy}}+F_{\mathrm{rpy}}=m_r{a}_{\mathrm{ry}}\end{array}\right\},$

Moment to barycenter d is:

F _rpx(L _r-r _r)sinθ _r+F _rpy(L _r-r _r)cosθ _r-F _rcxr _rsinθ _r-F _rcyr _rcosθ _r=I _rα _r

In upper two formulas: connecting rod quality is m _r, its moment of inertia is I _r, length is L _r, barycenter to crank movable end distance is r _r, the barycenter acceleration is respectively a at x and y direction _RxAnd a _Ry, it is θ with axial angle _r, rotational angular velocity is α _rThe power that crank acts on connecting rod is respectively-F at the component of x and y direction _RcxWith-F _RcyPiston action is respectively F in the power of crank at the component of x and y direction _RpxAnd F _Rpy

(3) crank mechanical equation

$\left.\begin{array}{c}{-F}_{\mathrm{mcx}}+F_{\mathrm{rcx}}=m_c{a}_{\mathrm{cx}}\\ {-F}_{\mathrm{mcy}}+F_{\mathrm{rcy}}=m_c{a}_{\mathrm{cy}}\end{array}\right\},$

Moment to centre of gyration o is:

-F _rcxR _csinθ _c+F _rcyR _ccosθ _c+M _c=I _cα _c

In upper two formulas: the crank quality is m _c, its moment of inertia is I _c, length is R _c, barycenter b acceleration is respectively a at x and y direction _CxAnd a _Cy, it is θ with axial angle _c, crank angle of rotation acceleration is α _c, its suffered rotating torque is M _cThe power that bent axle acts on crank is respectively F at the component of x and y direction _McxAnd F _McyThe power that connecting rod acts on crank is respectively F at the component of x and y direction _RcxAnd F _Rcy

(4) crankshaft lubrication mechanical equation

The mixed lubrication equation that uses with piston is identical;

(5) crankshaft vibration equation

Bent axle at the vibration equation of x and y direction is:

$\left.\begin{array}{c}M\stackrel{\&CenterDot;\&CenterDot;}{X}+C\stackrel{\&CenterDot;}{X}+\mathrm{KX}=F_x\left(t\right)\\ M\stackrel{\&CenterDot;\&CenterDot;}{Y}+C\stackrel{\&CenterDot;}{Y}+\mathrm{KY}=F_y\left(t\right)\end{array}\right\},$

Wherein: the axoplasm amount is M, and C is the crankshaft vibration damping, and K is crankshaft vibration rigidity, F _x(t) and F _y(t) be respectively stressed in x and y direction of bent axle, namely-F _McxOr-F _Mcy

4. based on the piston component oil-film force test macro of crankshaft vibration signal, it is characterized in that: this test macro comprises off-line simulation device and on-line testing analytical equipment;

Described off-line simulation device comprises:

Cylinder combustion pressure acquisition module is used for record cylinder combustion pressure;

Piston ring/piston oil-film force analysis module according to the correlation parameter of input, is used for analyzing the oil-film force of piston ring and piston;

The oil-film force data base access module is used for the access oil-film force and analyzes data;

The neural training module of oil-film force is used for that the oil-film force of oil-film force data base access module output is analyzed data and carries out neural metwork training, obtains the oil-film force through being trained;

The link motion analog module is used for receiving the oil-film force data of being trained, and obtains link motion data and output after simulation;

The crank-motion analog module is used for receiving the exercise data that the link motion analog module is exported, and obtains crank-motion data and output after simulation;

Crankshaft lubrication mechanical analysis module is used for receiving the crank-motion data of crank-motion analog module output, and through bent axle is lubricated mechanics property analysis, obtains crankshaft lubrication mechanics related data;

The crankshaft vibration analysis module is used for receiving aforesaid crank-motion data and crankshaft lubrication mechanics related data and to above-mentioned data analysis, obtains the crankshaft vibration signal under different working conditions;

Described on-line testing analytical equipment comprises:

The crankshaft vibration signal acquisition module is used for obtaining the crankshaft vibration signal under the aforesaid different working condition;

Crankshaft vibration signal analysis of neural network module is used for the crankshaft vibration signal that obtains is carried out neural network input and output relationship analysis;

Oil-film force on-line prediction module is obtained bent axle on-line vibration signal by sensor, by through analysis of neural network, obtains the two-dimentional oil-film force data of piston ring and piston.

Images