CN101110093A - Crankshaft dynamic balance design method - Google Patents

Abstract

The invention discloses a design method for dynamic balance of crankshaft, which is characterized in that: conduct slicing analysis on a model of crankshaft model, that is, segment the model of crankshaft component for limited times to a plurality of slices and then extract corresponding data of the crankshaft component model; compare the data with the preset data to judge whether the dynamic balance of the crankshaft component model is within the scope of production requirements. This method, with convenient operation, accurate and fast calculation and analysis, is able to conduct the analysis on the dynamic balance of the modeled crankshaft component and reflect in time the status of component dynamic balance, so that the design personnel are able to modify the crankshaft design in time to reach the required dynamic balance and completely prevent the testing of finished products via a dynamic balance machine. Therefore, compared with conventional method, this method not only enhances the calculation precision but also saves much investment and materials.

Description

Crankshaft dynamic balance design method

Technical field

The present invention relates to dynamic balancing measurement method, particularly a kind of design method for dynamic balance of crankshaft that is used to test crankshaft part to crankshaft part.

Background technology

Traditional crankshaft part designs often, and the designer relies on the practical experience of self to design, take the enterprising action balance check of dynamic balancing machine according to designer's design again after with crankshaft part machine-shaping then, this is the present domestic method of generally taking, and therefore the improvement to this step of dynamic balancing measurement all is confined to improvement on the dynamic balancing machine and design.For dynamic balancing machine, its dynamically balanced computational accuracy is not high, and the time of designing and developing is also longer, and input is also more.

Therefore the method for designing of just finishing dynamic balancing measurement in the design process of crankshaft part is in still relatively more blank at present field.

Summary of the invention

The invention provides a kind of design method for dynamic balance of crankshaft, after crankshaft part can being designed, just finish the dynamically balanced test to this design immediately, the crankshaft part finished product that can obtain moulding so almost is to conform with designing requirement fully.

Technical scheme of the present invention is as follows:

Design method for dynamic balance of crankshaft, it is characterized in that: with the analysis of cutting into slices of the model of crankshaft part, model with crankshaft part carries out axially cutting apart of limited number of time exactly, the crankshaft part model is divided into several sections, extract the corresponding data that carries out the bent axle part model then, judge that with resulting corresponding data and predefined data relatively, at last the transient equilibrium that obtains the crankshaft part model is whether in the scope of production requirement.

Described corresponding data comprises quality, radius vector.

Described section analytical procedure is to have set two balances according to the principle of rigid rotator dynamic balance analysis to correct face A, B, reference datum, and analytical procedure is as follows:

A, the benchmark when at first selecting two balance correction faces to calculate as transient equilibrium behind the balance correction face, are selected another one balance correction face by rotation or mobile part again;

B, user select an end face of crankshaft part to be used as part to carry out the reference datum of finite element when time cutting apart again, and this reference datum must be selected at last;

Whether C, affirmation previous step benchmark are selected correct, if it is incorrect then need to reselect, after benchmark is selected correctly, the length and the precision of being divided (the different of dividing precision will produce different influences to analysis result) of crankshaft part to be analyzed are set again, also have the rotating speed of corresponding balance quality and bent axle;

D, obtain corresponding data by entity analysis crankshaft part model, the dynamic balance analysis that carries out the bent axle part model again calculates;

E, obtain the Calculation results data, the data that all clearing analysis results and step C is set contrast, and obtain this crankshaft part model and whether satisfy dynamically balanced conclusion.

The dynamic balance analysis calculating of the model of crankshaft part described in the above-mentioned steps D just is meant corresponding data is put in the operational formula of rigid rotator dynamic balance analysis, calculate the balance mass-radius product, judge that by resulting balance mass-radius product the transient equilibrium of crankshaft part model is whether in the scope of production requirement.

The Calculation results data of described step e are included in uneven barycenter, mass-radius product, mass radius and the equivalent unbalance mass, on two balance correction faces.

The conclusion of described step e is a crankshaft part model when not satisfying transient equilibrium, and the balance of carrying out equivalent quality by the computing method of rigid rotator dynamic balance analysis is corrected and calculated, and draws the transient equilibrium numerical value that reaches production requirement.

Described balance is corrected and is calculated conclusion with 3-D view and numerical value demonstration result of calculation.

The computing method of described rigid rotator dynamic balance analysis are as follows:

For the mass distribution rotor in the same surface of revolution not, the centrifugal force that is produced when it rotates no longer is a plane concurrent force system, but space force system.Therefore, depend merely on the method that in a certain plane of rotation, adds, subtracts balance mass and can not solve the problem of unbalance dynamic.

When carrying out transient equilibrium calculating, need the inertial force that unbalance mass, produces is decomposed into two power in the given plane.This just need use the decomposition and the replacement of mass-radius product.

According to the synthetic and decomposition principle of parallel force, a power on a certain plane can replace it by two power in two selected arbitrarily parallel planes.Selected two balance basal plane A and B in the both sides on plane, unbalance mass, m place, the distance of establishing they and plane, m place is respectively a and b, and the distance between two balance basal planes of A and B is L.Be used for replacing two quality of m to be respectively m _AAnd m _B, in A and two balance basal planes of B, its radius vector is respectively r respectively for they _AAnd r _B, and m, m _AAnd m _BThe three is in same axial plane.Then m, m _AAnd m _BThe centrifugal force P, the P that are produced _AAnd P _BConstitute three parallel forces in the same plane.P _AAnd P _BThe condition that can replace fully is suc as formula (1).

$\left\{\begin{array}{c}{P}_A+P_B=P\\ P_{B}b=P_{A}a\end{array}\right.---\left(1\right)$

Add the relation between L and a, b, thereby can get formula (2).

$\left\{\begin{array}{c}{m}_A{r}_A+m_B{r}_B=\mathrm{mr}\\ m_B{r}_{B}b=m_A{r}_{A}a\\ L=a+b\end{array}\right.---\left(2\right)$

Separate following formula and can get formula (3).

$\left\{\begin{array}{c}{m}_A{r}_A=\mathrm{mrb}/L\\ m_B{r}_B=\mathrm{mra}/L\end{array}\right.---\left(3\right)$

If the unbalance mass, m of a rigid rotator ₁, m ₂And m ₃Lay respectively in plane 1,2 and 3 r ₁, r ₂And r ₃Be respectively its radius vector.When this rotor turns round with constant angular velocity ω, the centrifugal intertia force p that they produce ₁, p ₂And p ₃Constitute a space force system.In order to be translated into two static equilibrium problems in the plane of rotation, select two balance basal plane A and B, the distance of establishing between the two is L.Plane 1,2,3 is respectively b to the distance of balance basal plane B ₁, b ₂And b ₃, be respectively a to the distance of balance basal plane A ₁, a ₂And a ₃Work as m _iIn the time of between plane A and B, a _iAnd b _iJust be; Work as m _iWhen being positioned at outside plane A and the B, a _iAnd b _iBe negative.According to the decomposition and the replacement of the mass-radius product of narrating among the 1.2.1, with unbalanced weight mass-radius product m ₁r ₁, m ₂r ₂, m ₃r ₃Respectively by the m in balance basal plane A and the B ₁ ^Ar ₁And m ₁ ^Br ₁, m ₂ ^Ar ₂And m ₂ ^Br ₂, m ₃ ^Ar ₃And m ₃ ^Br ₃Replace (they are respectively in same axial plane).The radius vector of the unbalance mass, that replaces because of being decomposed equates with radius vector after the decomposition, so can get formula (4) by formula (3).

$\left\{\begin{array}{c}{m}_i^A=b_i{m}_i/L\\ m_i^B=a_i{m}_i/L\end{array}\right.,(i=\mathrm{1,2,3})---\left(4\right)$

After decomposing replacement, be the unbalance mass, problem reduction in three parallel planes the unbalance mass, problem that concentrates in two parallel balancing planes of A and B just.In like manner, there is unbalance mass, problem in four, five even the more a plurality of parallel plane to use the same method to be reduced to unbalance mass, problem in two selected arbitrarily surfaces of revolution.Thereby can in balance basal plane A, B, solve imbalance problem respectively according to the situation of mass distribution in the same surface of revolution.

In balance basal plane A, suppose m _b ^ABe the balance mass that should add, its radius vector and phasing degree are respectively r _b ^AAnd β _b ^A, the x and the y of the resultant vector of uneven vector are respectively C to component _x ^AAnd C _y ^A, the phasing degree of resultant vector is β ^AThe phasing degree of each unbalance mass, is β _i, then get formula (5).

$\left\{\begin{array}{c}{m}_b^A{r}_b^A\cos {\mathrm{\β}}_b^A=-C_x^A=-\mathrm{\Σ}{m}_i^A{r}_i\cos {\mathrm{\β}}_i\\ m_b^A{r}_b^A\sin {\mathrm{\β}}_b^A=-C_y^A=-\mathrm{\Σ}{m}_i^A{r}_i\sin {\mathrm{\β}}_i\end{array}\right.---\left(5\right)$

Similarly, at balance basal plane B Nei Kedeshi (6).

$\left\{\begin{array}{c}{m_b}^B{r}_b^B\cos {\mathrm{\β}}_b^B=-C_x^B=-\mathrm{\Σ}{m}_i^B{r}_i\cos {\mathrm{\β}}_i\\ m_b^B{r}_b^B\sin {\mathrm{\β}}_b^B=-C_y^B=-\mathrm{\Σ}{m}_i^B{r}_i\sin {\mathrm{\β}}_i\end{array}\right.$

Beneficial effect of the present invention is as follows:

This method is easy to operate, and computational analysis accurately, rapidly; When crankshaft part when designing, can carry out dynamic balance analysis to the crankshaft part that designs moulding apace, and can reflect the dynamically balanced situation of part in time, be convenient to the designer and in time crankshaft designs made corresponding modification, to reach dynamically balanced requirement, avoided utilizing dynamic balancing machine to finish test job fully to finished product; The relative classic method of this method not only computational accuracy is improved, but also has saved a large amount of financial resources, material resources.

Description of drawings

Fig. 1 is a workflow diagram of the present invention

Fig. 2 is the inertia resolution of force and replacement synoptic diagram of rigid rotator dynamic balance analysis computing method of the present invention

Fig. 3 is converted into two static equilibrium synoptic diagram on the surface of revolution for the transient equilibrium of a rotor in the rigid rotator dynamic balance analysis computing method of the present invention

Embodiment

A kind of design method for dynamic balance of crankshaft, with the analysis of cutting into slices of the model of crankshaft part, model with crankshaft part carries out axially cutting apart of limited number of time exactly, the crankshaft part model is divided into several sections, extract the corresponding data that carries out the bent axle part model then, at last relatively, with resulting corresponding data and predefined data judge at last obtain the crankshaft part model transient equilibrium whether in the scope of production requirement.

Described corresponding data comprises quality, radius vector.

Described section analytical procedure is to have set two balances according to the principle of rigid rotator dynamic balance analysis to correct face, reference datum, and analytical procedure is as follows:

A, the benchmark when at first selecting two balance correction faces to calculate as transient equilibrium behind the balance correction face, are selected another one balance correction face by rotation or mobile part again;

B, user select an end face of crankshaft part to be used as part to carry out the reference datum of finite element when time cutting apart again, and this reference datum must be selected at last;

Whether C, affirmation previous step benchmark are selected correct, if it is incorrect then need to reselect, after benchmark is selected correctly, the length and the precision of being divided (the different of dividing precision will produce different influences to analysis result) of crankshaft part to be analyzed are set again, also have the rotating speed of corresponding balance quality and bent axle;

D, obtain corresponding data by entity analysis crankshaft part model, the dynamic balance analysis that carries out the bent axle part model again calculates;

E, obtain the Calculation results data, the data that all clearing analysis results and step C is set contrast, and obtain this crankshaft part model and whether satisfy dynamically balanced conclusion.

The dynamic balance analysis calculating of the model of crankshaft part described in the above-mentioned steps D just is meant corresponding data is put in the operational formula of rigid rotator dynamic balance analysis, calculate the balance mass-radius product, judge that by resulting balance mass-radius product the transient equilibrium of crankshaft part model is whether in the scope of production requirement.

The Calculation results data of described step e are included in uneven barycenter, mass-radius product, mass radius and the equivalent unbalance mass, on two balance correction faces.

The conclusion of described step e is a crankshaft part model when not satisfying transient equilibrium, and the balance of carrying out equivalent quality by the computing method of rigid rotator dynamic balance analysis is corrected and calculated, and draws the transient equilibrium numerical value that reaches production requirement.

Described balance is corrected and is calculated conclusion with 3-D view and numerical value demonstration result of calculation.

The computing method of described rigid rotator dynamic balance analysis are as follows:

For the mass distribution rotor in the same surface of revolution not, the centrifugal force that is produced when it rotates no longer is a plane concurrent force system, but space force system.Therefore, depend merely on the method that in a certain plane of rotation, adds, subtracts balance mass and can not solve the problem of unbalance dynamic.

When carrying out transient equilibrium calculating, need the inertial force that unbalance mass, produces is decomposed into two power in the given plane.This just need use the decomposition and the replacement of mass-radius product.

According to the synthetic and decomposition principle of parallel force, a power on a certain plane can replace it by two power in two selected arbitrarily parallel planes.As shown in Figure 2, selected two balance basal plane A and B in the both sides on plane, unbalance mass, m place, the distance of establishing they and plane, m place is respectively a and b, and the distance between two balance basal planes of A and B is L.Be used for replacing two quality of m to be respectively m _AAnd m _B, in A and two balance basal planes of B, its radius vector is respectively r respectively for they _AAnd r _B, and m, m _AAnd m _BThe three is in same axial plane.Then m, m _AAnd m _BThe centrifugal force P, the P that are produced _AAnd P _BConstitute three parallel forces in the same plane.P _AAnd P _BThe condition that can replace fully is suc as formula (1).

$\left\{\begin{array}{c}{P}_A+P_B=P\\ P_{B}b=P_{A}a\end{array}\right.---\left(1\right)$

Add the relation between L and a, b, thereby can get formula (2).

$\left\{\begin{array}{c}{m}_A{r}_A+m_B{r}_B=\mathrm{mr}\\ m_B{r}_{B}b=m_A{r}_{A}a\\ L=a+b\end{array}\right.---\left(2\right)$

Separate following formula and can get formula (3).

$\left\{\begin{array}{c}{m}_A{r}_A=\mathrm{mrb}/L\\ m_B{r}_B=\mathrm{mra}/L\end{array}\right.---\left(3\right)$

As shown in Figure 3, establish the unbalance mass, m of a rigid rotator ₁, m ₂And m ₃Lay respectively in plane 1,2 and 3 r ₁, r ₂And r ₃Be respectively its radius vector.When this rotor turns round with constant angular velocity ω, the centrifugal intertia force p that they produce ₁, p ₂And p ₃Constitute a space force system.In order to be translated into two static equilibrium problems in the plane of rotation, select two balance basal plane A and B, the distance of establishing between the two is L.Plane 1,2,3 is respectively b to the distance of balance basal plane B ₁, b ₂And b ₃, be respectively a to the distance of balance basal plane A ₁, a ₂And a ₃Work as m _iIn the time of between plane A and B (as the m among Fig. 3 ₁, m ₂And m ₃), a _iAnd b _iJust be; Work as m _iWhen being positioned at outside plane A and the B, a _iAnd b _iBe negative.According to the decomposition and the replacement of the mass-radius product of narrating among the 1.2.1, with unbalanced weight mass-radius product m ₁r ₁, m ₂r ₂, m ₃r ₃Respectively by the m in balance basal plane A and the B ₁ ^Ar ₁And m ₁ ^Br ₁, m ₂ ^Ar ₂And m ₂ ^Br ₂, m ₃ ^Ar ₃And m ₃ ^Br ₃Replace (they are respectively in same axial plane).The radius vector of the unbalance mass, that replaces because of being decomposed equates with radius vector after the decomposition, so can get formula (4) by formula (3).

$\left\{\begin{array}{c}{m}_i^A=b_i{m}_i/L\\ m_i^B=a_i{m}_i/L\end{array}\right.,(i=\mathrm{1,2,3})---\left(4\right)$

After decomposing replacement, be the unbalance mass, problem reduction in three parallel planes the unbalance mass, problem that concentrates in two parallel balancing planes of A and B just.In like manner, there is unbalance mass, problem in four, five even the more a plurality of parallel plane to use the same method to be reduced to unbalance mass, problem in two selected arbitrarily surfaces of revolution.Thereby can in balance basal plane A, B, solve imbalance problem respectively according to the situation of mass distribution in the same surface of revolution.

In balance basal plane A, suppose m _b ^ABe the balance mass that should add, its radius vector and phasing degree are respectively r _b ^AAnd β _b ^A, the x and the y of the resultant vector of uneven vector are respectively C to component _x ^AAnd C _y ^A, the phasing degree of resultant vector is β ^AThe phasing degree of each unbalance mass, is β _i, then get formula (5).

$\left\{\begin{array}{c}{m}_b^A{r}_b^A\cos {\mathrm{\β}}_b^A=-C_x^A=-\mathrm{\Σ}{m}_i^A{r}_i\cos {\mathrm{\β}}_i\\ m_b^A{r}_b^A\sin {\mathrm{\β}}_b^A=-C_y^A=-\mathrm{\Σ}{m}_i^A{r}_i\sin {\mathrm{\β}}_i\end{array}\right.---\left(5\right)$

Similarly, at balance basal plane B Nei Kedeshi (6).

$\left\{\begin{array}{c}{m_b}^B{r}_b^B\cos {\mathrm{\β}}_b^B=-C_x^B=-\mathrm{\Σ}{m}_i^B{r}_i\cos {\mathrm{\β}}_i\\ m_b^B{r}_b^B\sin {\mathrm{\β}}_b^B=-C_y^B=-\mathrm{\Σ}{m}_i^B{r}_i\sin {\mathrm{\β}}_i\end{array}\right.---\left(6\right)$

Claims (7)

1. design method for dynamic balance of crankshaft, it is characterized in that: with the analysis of cutting into slices of the model of crankshaft part, model with crankshaft part carries out axially cutting apart of limited number of time exactly, the crankshaft part model is divided into several sections, extract the corresponding data that carries out the bent axle part model then, judge that with resulting corresponding data and predefined data relatively, at last the transient equilibrium that obtains the crankshaft part model is whether in the scope of production requirement.

2. according to the described design method for dynamic balance of crankshaft of claim 1, it is characterized in that: described corresponding data comprises quality, radius vector.

3. according to the described design method for dynamic balance of crankshaft of claim 1, it is characterized in that: described section analytical procedure is to have set two balances according to the principle of rigid rotator dynamic balance analysis to correct face A, B, reference datum, and analytical procedure is as follows:

A, the benchmark when at first selecting two balance correction faces to calculate as transient equilibrium behind the balance correction face, are selected another one balance correction face by rotation or mobile part again;

B, user select an end face of crankshaft part to be used as part to carry out the reference datum of finite element when time cutting apart again, and this reference datum must be selected at last;

Whether C, affirmation previous step benchmark are selected correct, if it is incorrect then need to reselect, after benchmark is selected correctly, the length and the precision of being divided (the different of dividing precision will produce different influences to analysis result) of crankshaft part to be analyzed are set again, also have the rotating speed of corresponding balance quality and bent axle;

D, obtain corresponding data by entity analysis crankshaft part model, the dynamic balance analysis that carries out the bent axle part model again calculates;

E, obtain the Calculation results data, the data that all clearing analysis results and step C is set contrast, and obtain this crankshaft part model and whether satisfy dynamically balanced conclusion.

4. according to the described design method for dynamic balance of crankshaft of claim 3, it is characterized in that: the dynamic balance analysis calculating of the model of crankshaft part described in the above-mentioned steps D just is meant corresponding data is put in the operational formula of rigid rotator dynamic balance analysis, calculate the balance mass-radius product, judge that by resulting balance mass-radius product the transient equilibrium of crankshaft part model is whether in the scope of production requirement.

5. according to the described design method for dynamic balance of crankshaft of claim 3, it is characterized in that: the Calculation results data of described step e are included in uneven barycenter, mass-radius product, mass radius and the equivalent unbalance mass, on two balance correction faces.

6. according to the described design method for dynamic balance of crankshaft of claim 3, it is characterized in that: the conclusion of described step e is that the crankshaft part model is not when satisfying transient equilibrium, carry out the balance of equivalent quality by the computing method of rigid rotator dynamic balance analysis and correct calculating, draw the transient equilibrium numerical value that reaches production requirement.

7. according to claim 1 or 3 described design method for dynamic balance of crankshaft, it is characterized in that: described balance is corrected and is calculated conclusion with 3-D view and numerical value demonstration result of calculation.