EFFECTIVE CHAIN-TYPE CVT DYNAMICS ANALYZING METHOD

Abstract

An effective chain-type CVT dynamic analysis method according to the present invention is capable of extracting stiffness data and deformation amount for each position from the pulley configuring in a flexible body and inputting into the pulley of the continuously variable transmission (CVT) system configuring in a rigid body to quickly and accurately calculate the deformation of the pulley due to contact with the pins of the chain.

Claims

1. An effective chain-type CVT dynamic analysis method, performed by a CVT dynamics analysis system, and extracting stiffness data and deformation amount for each position from a pulley configuring in a flexible body and inputting into a pulley of a continuously variable transmission (CVT) system configuring in a rigid body to quickly and accurately calculate deformation of a pulley due to contact with a pin, comprising: a pulley stiffness analysis step of calculating the influence of stiffness of a point located around the point in which stiffness data is measured when the stiffness data of the pulley configuring in the flexible body is measured, wherein the pulley stiffness analysis step comprises: a flexible body configuration step of configuring the pulley to be subjected to stiffness analysis in a flexible body, an analysis reference point setting step of setting an analysis reference point that is a reference point for analysis on the pulley, a stiffness analysis performing step of applying a load to each of the analysis reference point to perform stiffness analysis, a stiffness data extraction step of extracting load data according to a displacement of the analysis reference point to which the load is applied, and a deformation amount data extraction step of calculating the influence according to a stiffness of the point around the analysis reference point to which the load is applied.

2. The method of claim 1, wherein the analysis reference point is set in plural at predetermined intervals along a radial direction of the pulley.

3. The method of claim 2, wherein the analysis reference point is set in plural at predetermined intervals along a circumferential direction of the pulley.

4. The method of claim 1, wherein, in the deformation amount data extraction step, the deformation amount according to a stiffness of the point located in a circumferential direction based on the analysis reference point to which the load is applied is calculated.

5. The method of claim 1, wherein the effective chain-type CVT dynamics analysis method performed by a CVT dynamics analysis system further comprises: a system model configuration step of configuring a model of a continuously variable transmission based on multi-body dynamics, a stiffness data application step of mapping data calculated in the pulley stiffness analysis step for each position of the pulley configured in the system model configuration step, and an analysis result calculation step of calculating the deformation amount of the pulley due to the contact with a chain pin of a continuously variable transmission.

6. The method of claim 5, wherein, in the stiffness data application step, the stiffness data and deformation amount data of the analysis reference point calculated in the stiffness analysis step are mapped to a point corresponding to the analysis reference point.

7. The method of claim 6, wherein, in the stiffness data application step, the stiffness data and the deformation amount data of the analysis reference point located in the same radial direction are mapped in plural at predetermined intervals along a circumferential direction with respect to a center of the pulley.

8. The method of claim 5, wherein, in the analysis result calculation step, the deformation amount of the pulley generated around the analysis reference point is added and calculated.

9. The method of claim 8, wherein, in the analysis result calculation step, the deformation amount of the pulley according to the position on a circumferential direction based on the analysis reference point is added and calculated.

10. (canceled)

11. (canceled)

Description

DESCRIPTION OF DRAWINGS

[0040] FIG. 1 is a diagram of an effective chain-type CVT dynamic analysis method according to an embodiment of the present invention.

[0041] FIG. 2 is a diagram of a pulley stiffness analysis step according to another embodiment of the present invention.

[0042] FIG. 3 is a diagram of another analysis reference point setting step according to still another embodiment of the present invention.

[0043] FIG. 4 is a graph illustrating stiffness according to a position of an analysis reference point according to still another embodiment of the present invention.

[0044] FIG. 5 is a graph illustrating a deformation ratio in a circumferential direction of an analysis reference point according to still another embodiment of the present invention.

[0045] FIG. 6 is a graph illustrating a deformation amount of a pulley according to a position of the analysis reference point calculated in the analysis result calculation step according to still another embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0046] Hereinafter, preferred embodiments of an effective chain-type CVT dynamic analysis method according to the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, when detailed description of a known function or configuration is deemed to unnecessarily blur the gist of the present disclosure, the detailed description will be omitted. Unless otherwise specified, all terms in this specification are the same as the general meaning of the term understood by a person skilled in the art to which the present invention belongs, and when there is a conflict with the meaning of the term used in the present specification, it follows the definition used in the specification.

[0047] FIG. 1 is a diagram of an effective chain-type CVT dynamic analysis method according to an embodiment of the present invention.

[0048] An effective chain-type CVT dynamic analysis method (hereinafter referred to as an analysis method) according to the present invention may be performed by a CVT dynamics analysis system, and includes a pulley stiffness analysis step S1, a system model configuration step S2, a stiffness data application step S3, and an analysis result calculation step S4.

[0049] FIG. 2 is a diagram of a pulley stiffness analysis step according to another embodiment of the present invention, FIG. 3 is a diagram of another analysis reference point setting step according to still another embodiment of the present invention, FIG. 4 is a graph illustrating stiffness according to a position of an analysis reference point according to still another embodiment of the present invention, and FIG. 5 is a graph illustrating a deformation ratio in a circumferential direction of an analysis reference point according to still another embodiment of the present invention.

[0050] Hereinafter, a radial direction P-P′ refers to a direction in a straight line extending from a center of the pulley to an outside of the pulley, and a circumferential direction Q-Q′ refers to a direction of maintaining a predetermined distance from a center of the pulley and drawing a circle along a circumference of the pulley.

[0051] The pulley stiffness analysis step S1 is a step of configuring the pulley to be analyzed in a flexible body, and then calculating a stiffness value and a deformation amount according to a position of the pulley to be input to the pulley on the system model configured based on the multi-body dynamics.

[0052] As shown in FIG. 2, the pulley stiffness analysis step S1 further includes a flexible body configuration step S11, an analysis reference point setting step S12, a stiffness analysis performing step S14, a stiffness data extraction step S14, and a deformation amount data extraction step S15.

[0053] The flexible body configuration step S11 is a step of configuring the pulley to be subjected to the stiffness analysis with a flexible body for the stiffness analysis performing step S14 to be performed later.

[0054] The analysis reference point setting step S12 is a step of setting an analysis reference point that is a reference for analysis on the pulley. The analysis reference point may be regarded as a point in which the analysis for calculating the stiffness data and the deformation amount data is necessary among the points in which the pins constituting the chain of the CVT system is in contact with the pulley. The analysis reference point may be a plurality of any points on the pulley to be analyzed, and the setting may be different depending on required accuracy of analysis and analysis time, user setting, convenience of analysis, and the like. Preferably, as shown in FIG. 3, the analysis reference point may be set as a node on a grid forming predetermined intervals along a radial direction P-P′ and circumferential direction Q-Q′ of the pulley. More preferably, as shown in FIG. 3, the analysis reference point may be some nodes A11, B11, C11, and the like located on the same radial direction P-P′ among nodes on the grid.

[0055] Since this is because a shape of a general pulley has a symmetrical shape with respect to a center of the pulley, the stiffness data and deformation data measured at analysis reference points A11, B11, C11, and the like located on the same radial direction P-P′ may be mapping equally at predetermined intervals with respect to a center of the pulley in the stiffness data application step S3 to be described later, so that interpretation of other positions on the pulley may be omitted. That is, an entire analysis process via the analysis using the symmetry of the pulley may be simplified and analysis time may be reduced.

[0056] However, the setting of the analysis reference point is only an example, and various setting methods such as setting the analysis reference point or the like in a grid format at predetermined intervals throughout all surfaces on the pulley may be performed.

[0057] The stiffness analysis performing step S14 is a step of applying a load in a vertical direction to the analysis reference point to perform a stiffness analysis. Preferably, the stiffness analysis may be performed by using a flexible body-based finite element analysis (FEM) or Meshfree.

[0058] The stiffness data extraction step S14 is a step of extracting load data according to a displacement of each analysis reference point derived by the stiffness analysis performing step S14. The load data according to the displacement may be calculated in plural depending on the number of analysis reference points in the analysis reference point setting step S12. Preferably, the load data according to the displacement may be calculated in a form of a constant value k, a stiffness matrix such as full matrix or diagonal matrix, or a displacement-load graph as shown in FIG. 4.

[0059] The deformation amount data extraction step S15 is a step of calculating a deformation amount of the points around the analysis reference point. Preferably, a deformation amount in a circumferential direction of each analysis reference point located along a radial direction may be calculated in a deformation ratio. As shown in FIG. 3, considering that a pin of the chain of a CVT system is in contact along the circumferential direction Q-Q′ of the pulley, the deformation ratio may be extracted along the circumferential direction Q-Q′ of the analysis reference point. Preferably, as shown in FIGS. 3 and 5, the deformation ratio may be extracted at 15° intervals A11, A12, A13, and the like, A21, A22, A23, and the like, and A31, A32, A33, and the like along a circumferential direction of the analysis reference points A11, A21, A31, and the like, and a circumferential deformation ratios of the analysis reference point A1 may be expressed as α.sub.1, α.sub.2, α.sub.3 to α.sub.n.

[0060] As shown in FIG. 5, the deformation ratio α.sub.1, α.sub.2, α.sub.3 to α.sub.n is inversely proportional to the distance in the circumferential direction Q-Q′ of the analysis reference point, and in general, when more than 60 degrees along the circumferential direction with respect to a center of a pulley is far away, the deformation ratio α.sub.1, α.sub.2, α.sub.3, α.sub.n, and the like converges to zero.

[0061] The system model configuration step S2 is a step of configuring a continuously variable transmission (CVT) in a system model based on multi-body dynamics. The system model based on multi-body dynamics may include a rigid body, a connection configuration (joint), a load element, and the like, and each pulley and a chain are formed in contact.

[0062] The stiffness data application step S3 is a step of mapping the stiffness data and deformation data for each position calculated in the pulley stiffness analysis step S1 to the pulleys of the model configured in the system model configuration step S2. The stiffness data and the deformation amount data of the analysis reference point are mapped to corresponding positions on the pulley configured in the system model configuration step S2. As described above, the stiffness data and the deformation amount may be mapped by using symmetry of the pulley. Preferably, the stiffness data and deformation amount data of the analysis reference point located in the same radial direction are mapped in plural at predetermined intervals along the circumferential direction Q-Q′ with respect to a center of the pulley configured in the system model configuration step S2. More preferably, the stiffness data and deformation amount data of the analysis reference point located in the same radial direction P-P′ are mapped at 15 degree intervals along the circumferential direction Q-Q′ with respect to a center of the pulley configured in the system model configuration step S2.

[0063] FIG. 6 is a graph illustrating a deformation amount of a pulley according to a position of the analysis reference point calculated in the analysis result calculation step S4 according to still another embodiment of the present invention.

[0064] The analysis result calculation step S4 is a step of using the multi-body dynamics model system on which the mapping in the stiffness data application step S3 is reflected to calculate the deformation amount of the pulley due to contact with the chain pins of the CVT. Preferably, the deformation amount of the pulley calculated in the analysis result calculation step S4 may be calculated by reflecting the deformation amount of the pulley generating along the circumferential direction Q-Q′ based on the analysis reference point. More preferably, the deformation amount of the pulley calculated in the analysis result calculation step S4 may be calculated by reflecting the deformation amount along the circumferential direction of another analysis reference point located on the same circumferential direction Q-Q′ based on the analysis reference point.

[0065] Hereinafter, a process of calculating the actual deformation amount of the pulley by reflecting the deformation amount according to the circumferential deformation ratio of each analysis reference point will be described as an example.

[0066] In the configuration of the actual CVT, the points in which the chain pins come into contact with the pulley exist in plural at predetermined intervals along the circumferential direction Q-Q′ of the pulley, and accordingly, the actual deformation amount at any contact points is calculated by adding the deformation amount in the circumferential direction of the neighboring contact points.

[0067] When described with reference to FIG. 3, each point A12 to An marked in a circumferential direction of the analysis reference point A11 represents points to which the load is applied onto the pulley or points in contact with the chain pin, and is located at 15 degree intervals along a circumferential direction with respect to a center of the pulley.

[0068] For example, when a load is applied to point 1 A11 on the pulley, the deformation amount at that point (δ.sub.1, hereinafter referred to as ‘unit deformation amount’) may be expressed as

[00001]${\delta }_{1=}\frac{F}{k_1}$

(F is the magnitude of the load, and k.sub.1 is the stiffness value measured at point 1).

[0069] In the same manner, when a load is applied to the remaining points A12 to An on the pulley, the unit deformation amount at the remaining points A12 to An may also be expressed as each

[00002]${\delta }_{2=}\frac{F}{k_2},{\delta }_{3=}\frac{F}{k_3}\mathrm{.Math.},{\delta }_{7=}\frac{F}{k_7}.$

[0070] As described above, k1 to k7 representing the stiffness values may be values derived in the stiffness data extraction step S14 of the pulley stiffness analysis step S1 and have different values depending on a setting of the analysis reference point, user's designation, or the like in the analysis reference point setting step S12 respectively but be used by commonly by using the symmetry of the pulley to apply the stiffness value (k1=k2 to=kn=k) calculated at one analysis reference point A11.

[0071] On the other hand, the actual deformation amount at any contact points on the pulley is calculated by reflecting the deformation amount or the deformation ratio α.sub.1, α.sub.2, α.sub.3 to αn in the circumferential direction of neighboring contact points.

[0072] Accordingly, when a load is applied from points 1 A11 to point 7 A11 on the pulley, when an is the deformation ratio according to the position on the circumferential direction of the analysis reference point A11 calculated in the pulley stiffness analysis step S1, the deformation amount (δ.sub.1′, hereinafter referred to as ‘actual deformation amount)’) at point 1 in consideration of the deformation ratio in the circumferential direction of each analysis reference point becomes

δ.sub.1′=δ.sub.1×α.sub.1+δ.sub.2×α.sub.2+ . . . +δ.sub.7×α.sub.7.sub.(α1=1).

[0073] However, the contact points of the chain pins marked as the analysis reference points of FIG. 3 may be located at 15 degree intervals along a circumferential direction with respect to a center of the pulley, and in general, considering that the load at a point more than 60 degrees away from the reference point A11 in a circumferential direction is not influence on the deformation amount of the reference point, the actual deformation amount at point A11 may be δ.sub.1′=δ.sub.1×α.sub.1+δ.sub.2×α.sub.2+ . . . +δ.sub.5×α.sub.5 excluding after 6th deformation amount.

[0074] In the same manner, the actual deformation amount δ.sub.2′, δ.sub.3′ to δ.sub.7′ may be calculated for each of the remaining analysis reference points A12, A13, A14 to A17, and this may be expressed as a graph shown in FIG. 6.

[0075] As a result, in the same manner as above, the deformation amount of the pulley due to contact with the chain pin for the remaining analysis reference points B11, B12, B13, and the like and C11, C12, C13, and the like on the pulley may be calculated, and the entire deformation amount of the pulley due to contact with the chain pin based on the amount of deformation at each analysis reference point may be calculated.

[0076] The foregoing detailed description illustrates the present invention. In addition, the foregoing is intended to illustrate and describe the preferred embodiments of the invention and the invention may be utilized in various other combinations, modifications and environments. That is, it is possible to make changes or modifications within the scope of the concept of the invention disclosed herein, within the scope of equivalents to the above-described disclosure, and/or within the skill and knowledge of the art. The above-described embodiments are intended to describe the best mode for carrying out the technical spirit of the present invention and various modifications required in the specific applications and uses of the present invention are possible. Accordingly, the foregoing detailed description is not intended to limit the invention to the embodiments disclosed. Also, the appended claims should be understood to include other embodiments.

INDUSTRIAL APPLICABILITY

[0077] The present invention relates to a chain-type CVT dynamics analysis method and is applicable to a simulation analysis method for components in the automobile industry, etc.