JP2001311456A - Vibration analysis method and design aid method for transmission belt driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of the vibration analysis in performing analysis by using the vibration analysis model of engine auxiliary element driving system T wherein the auxiliary element driving belt 8 consisting of a V ribbed belt is wrapped around a crank pulley 1 having a V ribbed pulley on an engine crankshaft 2 and an alternator pulley 3 having the same V ribbed pulley on an alternator shaft 4, and wherein an autotensioner 10 is arranged to give the belt 8 a tension. SOLUTION: The vibration analysis is conducted by using the vibration analysis model in which each nodal point is linked with an elastic body element or a rigid element, wherein the crank pulley 1, the alternator pulley 3, idler pulleys 5, 6 and the autotensioner 10 are arranged as per actual layout and the auxiliary element driving belt 8 wrapped around the pulleys 1, 5, 6 and the tension pulley 21 of the autotensioner 10 is divided into infinitesimal segments by nodal points. The contacts between each pulley 1, 3, 5, 6, 21 and the belt 8 are modeled based on shear rigidity and frictional force, and each pulley 1, 3, 5, 6, 21 is modeled as an elastic body or a rigid body which rotates and/or vibrates. The autotensioner 10 is modeled as an element which maintains elastoplasticity after yielding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a method for analyzing a vibration of a drive belt drive system when a rotation fluctuation or a torque fluctuation is applied, and a method for supporting a design.

[0002]

2. Description of the Related Art In general, when designing a drive system for transmitting power using a power transmission belt, a power transmission belt is considered in consideration of a load, a belt tension, a pulley rotation speed, a belt speed, a pulley diameter, a pulley layout, and the like. Is devised so as not to have a short life. The contrivance includes, for example, changing the belt layout, pulley diameter, belt type, or changing the belt width and the number of belts.

Above all, engine accessory belts for driving engine accessories used in automobiles and the like (compressors for air conditioners, oil pumps for power steering, water pumps for cooling water, alternators for power generation, oil pumps for engine lubrication, etc.) In a drive system or a camshaft belt drive system using a timing belt for driving a camshaft, the crankshaft of the engine is used as a drive source. This causes fluctuation, torsional vibration of the crankshaft, and fluctuation of torque at each pulley. In particular, in an engine such as a diesel engine or a direct injection engine, in which the rotation fluctuation of the crankshaft is large, the auxiliary drive belt drives an auxiliary machine such as an alternator or a water pump while receiving a large rotation fluctuation. Due to this rotation fluctuation and torque fluctuation, the accessory drive belt is repeatedly vibrated in the longitudinal direction of the belt while rotating, and due to this repeated stimulation, the maximum tension of the belt is increased and the life is shortened,
Alternatively, the slip between the auxiliary pulley and the auxiliary drive belt occurs due to a decrease in the belt tension, and the slip does not play its role.
Problems such as generation of slip noise due to increase in belt slip, heat generation due to slip, and shortening of service life occur.

Although a tensioner is used to hold the tension of the accessory drive belt, it is difficult to accurately design the belt because the system acting on the belt differs depending on the layout of the accessory and the characteristics of the engine. , Need many verification experiments.

To solve these problems, Japanese Patent Application Laid-Open No. 1-2886
No. 56 discloses a method of detecting a slip ratio that causes abnormal noise of a belt. The whole transmission belt drive system is made into a vibration model, modal parameters are calculated by eigenvalue analysis, and a fluctuation tension is calculated using the modal parameters. There is known a method of performing a composite tension calculation together with a static tension calculation result.

However, according to this conventional method, when the fluctuating tension becomes large and the combined tension becomes zero or less, the transmission belt is calculated to support the compressive load.

In general, a power transmission belt uses a wire, cloth, film, or the like as its core wire, so that it can hold a tensile load but cannot hold a compressive load. That is, since the transmission belt has low bending stiffness, the transmission belt easily buckles when a compressive load is applied, and can hardly hold the compressive load.

As described above, in the actual phenomenon, although the power transmission belt cannot hold the compression load, there is a problem that the calculation load causes the difference that the compression load is applied. For this reason, in the calculation of the belt tension in the above proposed example, when the belt tension is zero, the force applied to the transmission belt drive system does not become close to the actual state, and a difference occurs between the calculation result and the actually measured value. As a result, it is not possible to accurately judge a fluctuation in belt tension or the like.

Accordingly, the applicant of the present application has a configuration in which the spring in the belt span portion is changed during the calculation, and when the strain applied to the spring element in the belt span portion is tensile strain,
While the spring constant of the belt span part is calculated as the value of the spring element, if the strain applied to the spring element of the belt span part is a compressive strain, the spring constant of the belt span part is made smaller than the spring constant of the belt span part. It has been proposed that the calculation be performed in a state where the spring element has been removed only when a low value or zero or a compressive strain has occurred (see Japanese Patent No. 2868995).

[0010]

However, the above proposal is not without problems. In other words, in the vibration calculation model of the proposed example, it is assumed that the belt does not slip on the pulley, and the two are inseparably contacted integrally. It is difficult to accurately reproduce (driving).

In addition, when an auto-tensioner for applying belt tension to the transmission belt drive system is provided, the auto-tensioner is modeled by a spring, so that the model of the auto-tensioner is a characteristic of the actual auto-tensioner. It is far from

From these points, it is difficult to accurately calculate the tension, acceleration, speed, displacement, and the like applied to the transmission belt drive system to accurately analyze the vibration of the drive belt drive system, and there is room for improvement. Was.

The present invention has been made in view of the above-mentioned points, and a main object of the present invention is to accurately predict a vibration generated in a belt with respect to a transmission belt drive system such as the engine accessory belt drive system. In order to improve the reliability of the analysis, the actual applied tension, acceleration, speed, displacement, etc. can be analyzed more accurately, and the numerical values are used to analyze the driving system of the transmission belt according to the actual situation, thereby increasing the reliability of the analysis. The aim is to reduce man-hours and shorten the development period.

[0014]

In order to achieve the above object, according to the present invention, when a vibration analysis of a drive belt drive system is performed, the vibration analysis model is wound around pulleys arranged according to a layout. The obtained transmission belt is divided into minute sections in the length direction, and a vibration analysis model in which the nodes are connected by an elastic element or a rigid element is used.

That is, according to the first aspect of the present invention, there is provided a method for analyzing vibration of a transmission belt driving system including at least a pulley composed of a driving and driven pulley and a transmission belt wound around the pulley. A vibration analysis model in which pulleys are arranged according to the layout and the power transmission belt is wound around the power transmission belt, and the wound power transmission belt is divided into small sections in the length direction and connected between the nodes with elastic elements or rigid elements It is characterized by performing vibration analysis.

According to the above configuration, in performing the vibration analysis of the transmission belt drive system, the pulley is arranged according to the layout and the transmission belt is wound around the transmission belt. Since a vibration analysis model is used in which the nodes are divided and the nodes are connected by elastic elements or rigid elements, the belt can contact or separate from the pulley, and the rotation of the pulley and the rotation of the belt can be set freely. For example, the vibration analysis of the transmission belt drive system can be obtained only by directly inputting the rotation characteristics of the drive pulley. Therefore, the tension, acceleration, speed, displacement, and the like applied to the transmission belt driving system can be analyzed with higher accuracy, and the vibration analysis of the transmission belt driving system can be accurately performed with higher accuracy in actuality.

According to the second aspect of the present invention, the contact between the pulley and the transmission belt is modeled by shear rigidity and frictional force, and the pulley is modeled as an elastic body or a rigid body that rotates, vibrates, or vibrates while rotating. In this case, the contact between the pulley and the transmission belt is caused by shear rigidity and frictional force.
In addition, since the pulley is modeled as an elastic body or a rigid body that rotates, vibrates, or rotates and vibrates, the vibration analysis model approximates the operation of the actual transmission belt driving system, and the analysis of the vibration of the transmission belt driving system can be improved. Can be done with precision.

According to the third aspect of the present invention, the transmission belt drive system includes an auto-tensioner for applying tension to the transmission belt, and the auto-tensioner is modeled as an element having elasto-plasticity even after yielding. In this case, the auto-tensioner in the vibration analysis model is modeled by an elasto-plastic body, so that the model of the auto-tensioner is closer to the actual auto-tensioner,
Vibration analysis of the transmission belt drive system can be performed with higher accuracy.

According to a fourth aspect of the present invention, in the transmission belt drive system, an auxiliary pulley including a V-ribbed pulley provided on a shaft of an auxiliary machine is used as a drive pulley and a crank pulley including a V-ribbed pulley provided on a crankshaft of the engine. Is a driven pulley, and an engine accessory belt drive system is an auxiliary accessory drive belt including at least an auxiliary drive belt formed of a V-ribbed belt wound around the crank and the accessory pulley as a transmission belt.
With this configuration, the vibration analysis of the engine accessory belt drive system can be performed with higher accuracy.

According to a fifth aspect of the present invention, there is provided a design support method for a power transmission belt drive system. In this invention, the power transmission is performed based on the analysis result of the vibration analysis method for the power transmission belt drive system according to any one of the first to fourth aspects. It is characterized by supporting the design of the belt drive system. According to the present invention, the transmission belt drive system can be designed with high precision and accuracy.

[0021]

FIG. 3 shows an engine accessory belt drive system T as a transmission belt drive system according to an embodiment of the present invention. Reference numeral 1 denotes a crank pulley composed of a V-ribbed pulley as a drive pulley. The crank pulley 1 is integrally mounted on a crankshaft 2 of an engine (not shown in its entirety). It rotates clockwise in the figure with fluctuations.

Reference numeral 3 denotes an alternator pulley composed of a V-ribbed pulley as a driven pulley (auxiliary pulley) disposed substantially above the crankshaft 2. The alternator pulley 3 is an input shaft of an alternator (not shown in its entirety). It is attached to a certain alternator shaft 4 in a rotating manner.

Reference numeral 5 denotes a first idler pulley disposed at a position slightly lower than the alternator pulley 3, and 6 denotes a crank pulley 1 and an alternator pulley 3.
The idler pulleys 5 and 6 are also V-ribbed pulleys.

Between the crank pulley 1 (drive pulley), the alternator pulley 3 (driven pulley), and the first and second idler pulleys 5 and 6, there is provided a V having a plurality of ribs (not shown) on an inner peripheral portion. An accessory drive belt 8 as a transmission belt composed of a ribbed belt is wound around the inner surface, and the layout is a serpentine drive layout.

The slack side span 8a between the crank pulley 1 and the second idler pulley 6, that is, the slack side of the accessory drive belt 8 rotating clockwise in FIG. 8 is provided with a proportional damping dry auto tensioner 10 which is constantly pressed by a tension pulley 21 formed of a flat pulley toward the inner surface side to automatically adjust the belt tension.

As shown in an enlarged detail in FIG. 4, the auto tensioner 10 is a tapered cylindrical spindle which is disposed in parallel with the crankshaft 2 and is fixed to a fixed portion (for example, an engine body) so as not to rotate. The spindle 11 has a rear end portion integrally formed with a rear end of the spindle 11. A double cylindrical rotating member 14 is externally fitted to the spindle 11 via an insert bearing 13 made of resin or the like having a predetermined friction coefficient so as to be rotatable from the distal end side. The rotating member 14 is used for the spindle 1
1, a cylindrical inner cylindrical portion 15 externally fitted via the insert bearing 13, a cylindrical outer cylindrical portion 16 disposed concentrically outside the inner cylindrical portion 15, and an inner and outer cylindrical portion 15. 1
A disk-like flange portion 17 connecting the base members 6 to each other on the base end side (the tip end side of the spindle 11) is integrally formed. The flange 17 prevents the front plate 18 from slipping off and connects the flange 17.
A disc-shaped thrust washer 19 made of resin or the like having a predetermined friction coefficient is interposed between the front plate 18 and the front plate 18. An arm 20 extending in the radial direction is formed integrally with the outer cylindrical portion 16 of the rotating member 14, and the tension pulley 21 is attached to a tip end of the arm 20 via a bearing 22 around a rotation axis parallel to the spindle 11. The slack-side span 8a of the accessory drive belt 8 is wound around the tension pulley 21 on the outer surface.

Further, a cylindrical spring support 23 is externally fitted to the outer surface of the inner cylindrical portion 15 of the rotating member 14,
The spring support 23 has a flange portion 23a on the base end side of the spindle 11 for contacting the rear cup portion 12 of the spindle 11. A spring 24 composed of a torsion coil spring is disposed around the spring support 23 in the inner and outer cylindrical portions 15 and 16 of the rotating member 14, and one end of the spring 24 is connected to the rear cup portion 12 of the spindle 11, and The other end is engaged with the base end side of the outer cylindrical portion 16 of the rotating member 14, and the rotating member 14, the arm 20 and the tension pulley 21 are moved in one direction around the spindle 11 by the torsion spring force of the spring 24. (In the counterclockwise direction in FIG. 3), the tension pulley 21 constantly presses the loose side span 8a of the accessory drive belt 8, and the spring force of the spring 24 and the accessory drive belt 8 When the rotating member 14, the arm 20, and the tension pulley 21 rotate around the spindle 11 due to the reaction force of By attenuating the braking at a predetermined damping ratio by ring 13 and thrust washer 19, and the belt tension so as to automatically adjust.

A description will be given of a method of performing a vibration analysis using a vibration analysis model in the belt longitudinal direction of the engine accessory belt drive system T having the above configuration, and a method of supporting the design of the engine accessory belt drive system T based on the analysis result. I do. FIG.
FIG. 1 schematically shows a vibration analysis system of the engine accessory belt drive system T. The analysis system has a calculation unit 30. The arithmetic unit 30 is configured to input the engine characteristics, the characteristics of the auxiliary equipment (alternator), the characteristics of the belt 8 itself, the characteristics of the auto tensioner 10, and the layout of the engine auxiliary equipment belt drive system T as data. . Specifically, the data of the engine characteristics include the number of cylinders of the engine, the number of cycles of the combustion stroke, the number of rotations, and the waveform of the rotation fluctuation or rotation speed, and the data of the accessory characteristics include the average load and fluctuation of the alternator. Load and inertia, data on belt characteristics include tensile stiffness, shear stiffness, damping and density, and data on tensioner characteristics include spring rate, damping rate and inertia. The layout data includes pulley position, auto tensioner 1
There is a zero position and belt tension.

When the vibration analysis of the engine accessory belt drive system T is performed by the vibration analysis model in the arithmetic section 30, the crank pulley 1, the alternator pulley 3, the idler pulleys 5, 6 and the auto tensioner 10 are used as shown in FIG. 3, the accessory drive belt 8 is wound around the pulleys 1, 5, 6 and the tension pulley 21 of the auto tensioner 10, and the wound accessory drive belt 8 is lengthened. Vibration analysis is performed using a vibration analysis model in which nodes are divided into minute sections in the vertical direction and the nodes are connected by an elastic element or a rigid element.

At this time, each pulley 1, 3, 5, 6, 21
The contact between the belt and the belt 8 is modeled by shear rigidity and frictional force, and the pulleys 1, 3, 5, 6, and 21 are modeled as an elastic body or a rigid body that rotates or vibrates or vibrates while rotating. On the other hand, the auto tensioner 10 is modeled as an element having elasto-plasticity even after yielding.

Further, the vibration analysis based on such a vibration analysis model allows, for example, the tension of the belt 8, the displacement, speed and acceleration of the alternator pulley 3, the slip between the belt 8 and each of the pulleys 1, 3, 5, 6, 21 and the layout. , The displacement, speed, acceleration, and the like of the auto tensioner 10 are output. Further, the design of the engine accessory belt drive system T is supported based on the analysis result of the vibration analysis method of the same.

More specifically, FIG. 1 shows a vibration analysis model used for analyzing the vibration of the engine accessory belt drive system T. In this vibration analysis model, the span portion of the belt 8 is controlled by springs K1 to K5. Modeling. In the belt drive system, pulleys 1, 3, 5, 6, 2
1 and the pulley 1,
Since the rubber portion located between the pulleys 1, 3, 5, 6 and 21 also functions as a spring, the core of the belt 8 wound around the pulleys 1, 3, 5, 6, 21 and the pulleys 1, 3, 5 ,
Springs K6 to K10 at the rubber portion between the first and second rubbers 6 and 21 are added. Further, damping elements C1 to C10 for expressing internal damping of the vibration model and friction elements S1 to S5 for expressing friction are added, and the belt 8 and each pulley 1,
The contact is defined between 3, 5, 6, 21 and the model is driven by frictional force. Also, the auto tensioner 1
For 0, the spring K11 and the friction element S6 are added.

FIG. 2 shows an FEM analysis model (finite element analysis model) of the analysis model of FIG.
Each site in the M analysis model is as shown in Table 1, and details thereof will be described below. In the figure, ● indicates a clause,
− Represents a beam element, ■ represents an inertia element, and 〇 represents a rigid element. 2, and extend in a direction perpendicular to the plane of FIG.

[0034]

[Table 1]

Accessory Drive Belt The accessory drive belt 8 is modeled by dividing nodes into small sections in the length direction and connecting the nodes with a beam element having a rectangular cross section as an elastic element or a rigid element. . The accessory drive belt 8 has a very high rigidity in the longitudinal direction in the plane and a small rigidity in the out-of-plane direction. Therefore, in order to achieve both tensile rigidity and bending rigidity, the beam cross-sectional shape is extremely large. It is thin. In addition, the length of the beam element is
Of the minimum pulley winding length.

Alternator pulley (auxiliary pulley) The alternator pulley 3 (auxiliary pulley) is modeled by a rigid body. The outer diameter of the alternator pulley 3 is set at the position of the core wire when the accessory drive belt 8 is wound around the pulleys 1, 3, 5, 6, and 21.

The shear rigidity between the auxiliary drive belt and the auxiliary pulley is the shear rigidity between the auxiliary drive belt 8 and the auxiliary pulley when the auxiliary drive belt 8 is wound around the alternator pulley 3 (the auxiliary pulley). And the shear rigidity of the ribs of the accessory drive belt 8 that are sandwiched between the core wire and the alternator pulley 3. This is a beam element that is necessary because the accessory drive belt 8, which is originally a V-ribbed belt, is modeled as a beam element having a rectangular cross section, that is, a flat belt. The shape of the beam element is set so that the torsional spring constant and the longitudinal elastic modulus are the same value, and the relationship between the torsional shear strain and the torsional torque is the same as the relationship between the circumferential portion shear strain and the load. I have to.

The moment of inertia of the accessory here is determined by the alternator body,
The moment of inertia including the alternator pulley 3 and the alternator shaft 4 is represented by one inertia element.

The damping characteristic of the auto tensioner The proportional damping dry type auto tensioner 10 includes a spring 24
6 shows the friction damping characteristic as shown in FIG. When the accessory drive belt 8 of the nominal length is applied to the accessory layout, the rotation angle of the arm 20 of the tensioner 10 in a state where the belt tension and the tension of the tensioner 10 are balanced is referred to as a nominal angle. Is given to the belt 8 by a nominal torque A. The spring rate indicates a rate at which the tension of the tensioner 10 on the belt 8 increases as the rotation angle of the arm 20 of the tensioner 10 increases. Further, the damping ratio represents the amount of attenuation of the tensioner 10, and is obtained by the following equation. B
Is the difference between the torques during loading and unloading. Damping ratio (%) = (B / 2A) × 100 The damping characteristic of the auto tensioner 10 is the same as the shear rigidity between the accessory drive belt and the accessory pulley.
By setting a beam element extending in the direction perpendicular to the plane of the drawing from the center of oscillation of 0, and giving an element having elasticity and plasticity even after yielding as shown in FIG. A characteristic having spring stiffness and friction damping as shown in FIG. 2 is reproduced. FIG. 7 substitutes for the hatched portions in FIG.

Friction Characteristics A dynamic friction coefficient μ between the accessory drive belt 8 and the alternator pulley 3 uses an actually measured value.

Here, the characteristics of the auto tensioner 10 will be described in detail. Since the auto tensioner 10 employs a method of applying damping by friction, as shown in FIG. 6, the relationship between the force applied to the tension pulley 21 and the displacement is represented by points P1 and P2 during loading and points P3 and P2 during unloading.
Pass through each of the four. Point P when the direction of force changes
A movement is performed that connects the upper and lower lines through a line having a larger inclination than the line connecting the points P1, P2 and the points P3, P4. The former points P1, P2 and points P3, P4
The movement on the line connecting the two is caused by the movement of the arm 20 of the auto tensioner 10 and the friction member (the insert bearing 1).
3 and the thrust washer 19) are generating a slip force, and the latter is a state in which the friction member does not slip and other members are deformed.

The following conditions are provided for modeling the state of the spring of the tensioner 10 as described above. (1) A kinematic hardening rule that models plastic deformation of a material is used to model a spring constant when a friction member slides. (2) To represent the spring 24 composed of a torsion spring, a torsion bar is set up on a pivot to model it. (3) The course on the line connecting the points P1 and P2 and the points P3 and P4 is treated as a plastic state (Plastic state), and the deformation connecting these upper and lower courses is regarded as an elastic state (E).
(last state). (4) Defining a model only with elasto-plasticity requires a belt 8
Since the initial tension of the arm 20 becomes zero, a torsional force corresponding to the initial tension is applied to the pivot of the arm 20 as an external force.

With such a modeling, as the damping characteristics of the auto tensioner 10, a characteristic in which the history of the torque and the torsion angle substantially matches the actual auto tensioner 10 is obtained.

Therefore, in this embodiment, when performing the vibration analysis of the engine accessory belt drive system T,
As a vibration analysis model, a crank pulley 1, an alternator pulley 3, idler pulleys 5, 6 and an auto tensioner 10 are arranged according to an actual layout, and an accessory drive belt 8 made of a V-ribbed belt is wound around them. 8 is divided into minute sections in the length direction, and a model in which the nodes are connected by an elastic element or a rigid element is used, so that the accessory drive belt 8 contacts the pulleys 1, 3, 5, 6 Can move away from it,
The rotation of the pulleys 1, 3, 5, 6 and the rotation of the belt 8 can be set freely. Therefore, the vibration analysis of the engine accessory belt drive system T can be obtained only by directly inputting, for example, the rotation characteristics of the crank pulley 1 and therefore the rotation characteristics of the engine.

In addition, each of the pulleys 1, 3, 5, 6, 2
1 and the accessory drive belt 8 are modeled by shear stiffness and frictional forces, and the pulleys 1, 3, 5, 6, 21 are modeled as rotating, oscillating or rotating and oscillating elastic or rigid bodies. Therefore, the vibration analysis model approximates the operation of the actual transmission belt drive system.

Since the auto-tensioner 10 in the vibration analysis model is modeled by an element having elasticity and plasticity even after yielding, the model of the auto-tensioner 10 is also approximated by the actual auto-tensioner 10. .

From the above, the tension, acceleration, speed, displacement, and the like applied to the engine accessory belt drive system T can be analyzed with higher accuracy, and the vibration analysis and design of the drive system of the accessory drive belt 8 can be actually performed. According to the above, it is possible to accurately and accurately perform the analysis, to improve the reliability of analysis and design, and to shorten the development period by reducing the number of experimental steps.

In the above-described embodiment, the alternator is used as an auxiliary machine, but a pump for a power steering device of an automobile, a compressor for an air conditioner, a water pump, an oil pump, or the like may be used as an auxiliary machine. Further, in the above-described embodiment, the engine accessory belt drive system T including the auto tensioner 10 has been described.
It is needless to say that the present invention can be applied to a transmission belt drive system without the auto tensioner 10 and a transmission belt drive system other than the engine accessory belt drive system T as in the above-described embodiment.

[0049]

Next, a specific embodiment will be described. (Analysis conditions) The accessory drive belt 8 has a V having six ribs.
It was a ribbed belt. The rotation speed (engine rotation speed) of the crank pulley 1 was 1000 ± 50 rpm, and the crank pulley 1 (engine) was rotating with a fluctuation of ± 5%. As the rotation output data of the crank pulley 1, data in an experiment described later was directly input. The load of the alternator was 40 A (ampere). The moment of inertia of the alternator pulley 3 is 4.35 × 10 ^-2 N
M, idler pulleys 5, 6 and tension pulley 21
Were set to 4.90 × 10 ⁻³ N · m. The moment of inertia of the auto-tensioner 10 at the swing center was 3.30 × 10 ⁻² N · m. The auto tensioner 10 has a spring rate of 0.54 N · m / de.
g, damping rate 20%, nominal torque 15.2N
m.

(Analysis Procedure) Analysis was performed according to the following procedure. (1) The crank pulley 1, which is a fixed pulley, the alternator pulley 3, the idler pulleys 5, 6, and the tension pulley 21 are arranged in the layout shape shown in FIG. , 21 in the layout shape. (2) A forced displacement is applied to the auto tensioner 10 to apply an initial tension to the accessory driving belt 8. (3) A forced rotational displacement of 180 ° or more is applied to the crank pulley 1 to make the tension of the accessory drive belt 8 that is uneven on the alternator pulley 3 due to friction constant. (4) Apply load torque to the alternator pulley 3. (5) Set the crank pulley 1 from 0 rpm to 1000 rpm
m, the acceleration was increased at a constant acceleration, and thereafter, the measured angular velocity history in an experiment described later was given. Incidentally, the above (1) to (4)
Is a static analysis, and (5) is a dynamic analysis.

(Experiment) Each data was measured to verify the analysis result. As shown in FIG. 3, the crank pulley 1,
Electromagnetic pickups 32 are arranged around the alternator pulley 3 and the first idler pulley 5, respectively.
The number of rotations of 5 was measured. The displacement of the tension pulley 21 in the auto tensioner 10 is measured by a laser displacement meter 33.
Was measured. The strain gauges 34, 34 are attached to the two idler pulleys 5, 6, respectively.
The tension of the accessory drive belt 8 was calculated from the distortion amount of No. 4.
The accessory drive belt 8, the alternator pulley 3, the tensioner 10, and the test conditions used in this experiment are the same as in the above analysis.

(Consideration of Analysis Results) The analysis results together with the experimental results are shown in FIGS. 8 shows the rotational speed (rotation speed) of the crank pulley 1 and the alternator pulley 3, FIG. 9 shows the tension of the tension side span of the accessory drive belt 8, and FIG. 10 shows the displacement of the tension pulley 21. ing. In each figure, “Cal.” Indicated by a thick solid line indicates an analysis result (analysis value), and “Ex.” Indicated by a thin solid line.
p. Indicates the experimental results (experimental values). Further, “C / S” in FIG. 8 indicates the rotation speed of the crank pulley 1 and “ALT” indicates the rotation speed of the alternator pulley 3, respectively.

In the analysis result of the rotation speed of the alternator pulley 3 shown in FIG. 8, although there is a slight phase difference, the experimental result can be accurately reproduced. Under this condition, the slip ratio of the alternator pulley 3 is 0.05% (experimental value), which means that there is almost no slip. However, since the slip between the accessory drive belt 8 and the alternator pulley 3 is reproduced slightly larger in the analysis value, it is considered that a phase difference occurs in the rotation speed.

Also, the analysis result of the belt tension shown in FIG. 9 can be analyzed with high accuracy as in the case of the above-mentioned rotation speed. According to the analysis result of the belt tension, the accessory drive belt 8 is always in a state where the tension is applied. It is the minimum condition that the layout of the engine accessory belt drive system T is satisfied if the tension on the tension side span of the belt 8 does not become 0 (zero) N or less as described above. Is considered to hold.

Regarding the displacement amount of the tension pulley 21 of the auto tensioner 10 in FIG. 10, the damping characteristics of the auto tensioner 10, such as the spring constant and the damping rate, can be faithfully reproduced on the carrier of the beam element. Analysis results are small. This is considered to be due to factors such as the contact state between the alternator pulley 3 and the accessory drive belt 8 and string vibration.

In any case, the overall analysis result is equivalent to the experimental value, and has sufficient accuracy for designing the engine accessory belt drive system T (transmission belt drive system), its auto tensioner 10, and its layout. It is supported by doing.

[0057]

As described above, according to the first aspect of the present invention, at least the pulley including the driving and driven pulleys,
When analyzing the vibration of the transmission belt drive system having the transmission belt wound around these pulleys, the pulleys are arranged according to the layout, the transmission belt is wound, and the wound transmission belt is moved in the length direction. Vibration analysis was performed using a vibration analysis model in which nodes were divided into minute sections and the nodes were connected by an elastic element or a rigid element. Further, in the invention of claim 2, the contact between the pulley and the transmission belt is modeled by shear rigidity and frictional force, and the pulley is modeled as an elastic body or a rigid body that rotates, vibrates or rotates and vibrates. According to these inventions, the transmission belt is modeled so as to be in contact with or separated from the pulley, the rotation of the pulley and the rotation of the belt can be set freely, and the analysis of the drive system of the transmission belt can be performed more accurately and accurately. In addition, it is possible to accurately analyze fluctuations in belt tension and fluctuations in rotation on the driven side, thereby improving the reliability of vibration analysis and shortening the development period by reducing the number of experimental steps.

According to the third aspect of the present invention, when the transmission belt drive system has an auto tensioner, the auto tensioner is modeled as an element having elasto-plasticity even after yielding, so that the model of the auto tensioner is reduced. The model can be approximated by an actual auto-tensioner, and the vibration analysis of the transmission belt drive system can be performed with higher accuracy.

According to the fourth aspect of the present invention, the transmission belt drive system comprises a crank pulley comprising a V-ribbed pulley provided on the crankshaft of the engine and a V-shaped pulley provided on the shaft of the auxiliary machine.
The vibration analysis of the engine accessory belt drive system is further improved by providing an accessory pulley consisting of a ribbed pulley and an accessory drive belt consisting of at least a V-ribbed belt wound around the crank and the accessory pulley. It can be performed accurately with accuracy.

According to the fifth aspect of the present invention, the design of the transmission belt drive system is supported on the basis of the analysis result of the vibration analysis method, so that the design of the transmission belt drive system can be accurately and accurately performed. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a diagram showing a vibration analysis model of an engine accessory belt drive system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a finite element analysis model of an engine accessory belt drive system.

FIG. 3 is a schematic diagram showing an engine accessory belt drive system.

FIG. 4 is an enlarged cross-sectional view of the auto tensioner.

FIG. 5 is a diagram showing a configuration of a vibration analysis system for an engine accessory belt drive system.

FIG. 6 is a diagram illustrating damping characteristics of an auto tensioner.

FIG. 7 is a diagram for use in a calculation example when modeling a friction plate slip force of an auto tensioner.

FIG. 8 is a characteristic diagram showing analysis results of rotational speeds of a crank pulley and an alternator pulley together with experimental results.

FIG. 9 is a characteristic diagram showing an analysis result of a tension in a tension side span of the belt together with an experimental result.

FIG. 10 is a characteristic diagram showing an analysis result of a displacement amount of a tension pulley of the auto tensioner together with an experimental result.

[Explanation of symbols]

 T Engine accessory belt drive system (drive belt drive system) 1 Crank pulley (drive pulley) 2 Crank shaft 3 Alternator pulley (driven pulley, accessory pulley) 4 Alternator shaft 5, 6 Idler pulley 8 Auxiliary drive belt (drive belt) 8a Loose side span 10 Auto tensioner 13 Insert bearing 19 Thrust washer 20 Arm 21 Tension pulley 24 Spring 30 Calculation part

Claims (5)

[Claims] 1. A method for analyzing vibration of a transmission belt drive system including at least a pulley composed of a driving and driven pulley and a transmission belt wound around the pulley, wherein the pulley is arranged in a layout. The power transmission belt is wound around the power transmission belt, and the wound power transmission belt is divided into minute sections in the length direction, and vibration analysis is performed using a vibration analysis model in which the nodes are connected by an elastic element or a rigid element. Analysis method for power transmission belt drive system. 2. The vibration analysis method for a power transmission belt drive system according to claim 1, wherein the contact between the pulley and the power transmission belt is modeled by shear rigidity and frictional force, and the pulley rotates or vibrates or vibrates while rotating. A vibration analysis method for a transmission belt drive system characterized by modeling as a body or a rigid body. 3. The vibration analysis method for a power transmission belt drive system according to claim 1, wherein the power transmission belt drive system includes an auto-tensioner for applying tension to the power transmission belt. A vibration analysis method for a transmission belt drive system characterized by modeling as a plastic element. 4. The vibration analysis method for a transmission belt drive system according to claim 1, wherein the transmission belt drive system uses a crank pulley including a V-ribbed pulley provided on a crankshaft of an engine as a drive pulley, An engine accessory belt having an accessory pulley composed of a V-ribbed pulley provided on a shaft of the accessory as a driven pulley, and an accessory drive belt composed of at least the V-ribbed belt wound around the crank and the accessory pulley as a transmission belt. A vibration analysis method for a transmission belt drive system, which is a drive system. 5. A design support for a power transmission belt drive system based on an analysis result of the vibration analysis method for a power transmission belt drive system according to any one of claims 1 to 4. Method.