CN101144755A - Measuring method for removing tyre uniformity test device systematic eccentricity - Google Patents

Abstract

The invention relates to a measuring method for a system eccentric center of a removing tire uniformity test set. In order to solve the problem, the invention utilizes the characteristic that the composite force of a plurality of groups of radial forces and lateral forces of a tire is zero, and measures the non uniform data existing in the chief axis system itself to label the non uniform value of the test set itself before the tire uniformity test is made and in the way that a plurality of actual measurement data is overlapped and the average value is acquired. During a normal measurement, when the data collection is completed, the collected data deducts an inherent eccentric center data of the system, an effective tire uniformity data can be acquired, therefore, the accuracy of the uniformity data calculation and the reliability of the judging of the tire quality can be improved.

Description

Remove the measuring method of tyre uniformity test device systematic eccentricity

Technical field

The present invention relates to a kind of measuring method, is the method for the systematic error that exists in the tire uniformity measurement system being measured and calibrated occurrence, belongs to the tire checking technical field.

Background technology

Tire is that member is carried out in the main action of motor vehicles, and stablizing and whether meeting the Safety Design standard of tyre performance will directly determine to use the personal security of motor vehicles.Tire is the rotatable body of a kind of circular ring type of tubular section, and it is to be processed through applying, moulding, sulfuration typing by rubber preformed material, compounded rubber preformed material that multilayer has an all-steel cord.The tire of described structure, its constituent material exist density unevenness inevitably, problem such as geometric deformation is arranged, and just the tire of often saying is inhomogeneous.According to relevant mechanics principle, there is to a certain degree uneven tire, under the high speed rotating situation, must produce radial force, the side force of alternation, thereby can cause the vibration or the noise of automobile, also can have influence on speed, comfort level or the smoothness of automobilism.

For a uniform tire of profile in theory, radial force should be invariable, and side force is 0.But can't really there be tire fully uniformly in tire in the reality because constituent material exists density unevenness inevitably, problem such as geometric deformation is arranged.Because tire is inhomogeneous, so tire will produce the fluctuation of radial force and the fluctuation of side force when rotated by constant load pressure and constant speed.

But when using uniformity test device and detect, by sensor measurement to radial force fluctuation and side force fluctuation be not only owing to tire inhomogeneous causes, some is that reason owing to axis system self causes.This shows that in the main shaft rotation process, each step radius of wheel rim is not a definite value up and down, himself just exists to beat, and when tire is clamped in the wheel rim and after the inflation, the beating of the wheel rim tire that can be added to gets on.Perhaps, the axis of main shaft and loading wheel axis are also not parallel but have an angle, can produce taper effect to detected tyre equally.Also having a kind of may be that the pivot center of last wheel rim does not overlap with the axis of main shaft, then can produce angular effect etc. to detected tyre.

More than since the off-centre that axis system produces all can the True Data of tire be impacted because the homogeneity off-centre that the factor of system itself causes radial force extra under the normal measurement situation and side force to be called as system.

Therefore, in inhomogeneity measuring process, the packet that is collected during normal the measurement contains two kinds of compositions, and a kind of is the caused radial force of unevenness and the side force fluctuation of tire itself, and another kind is because inhomogeneous radial force that causes that axis system itself exists and side force fluctuation.Whether the homogeneity of directly utilizing above-mentioned data of gathering to calculate tire is inaccurate, can directly have influence on the detection for the tire production quality usually.

Summary of the invention

The measuring method of removal tyre uniformity test device systematic eccentricity of the present invention, its purpose is to address the above problem and utilizes that same tire forms that radial force and side force are made a concerted effort is zero characteristic more, before carrying out uniformity test of tire, superpose and ask average mode by will organize measured data more, measure the inhomogeneous data that exist by axis system itself, thereby calibrate the inhomogeneous amount of himself for test unit.When normal measurement, after image data is finished, the data of gathering are deducted the eccentric data of the intrinsic homogeneity of system, effective tyre evenness data be can obtain, thereby the accuracy of homogeneity data computation and the confidence level of judge tire quality improved.

For achieving the above object, before carrying out uniformity test of tire, use the measuring method of described removal tyre uniformity test device systematic eccentricity, select for use a tire to carry out actual measurement arbitrarily.

The radial force of described tire, be when proper testing tire radially, be equal to stressed perpendicular on the main shaft axial direction; The lateral force of described tire, be tire when proper testing side direction, be equal to stressed on the main shaft axial direction.

For same detected tyre, by the many compositions that draw after 180 ° of rotations right radial force or side force numerical value, all have equal and opposite in direction, characteristic that direction is opposite, promptly making a concerted effort is zero, just aggregate value is zero.

As long as many combining abilities that this detected tyre produces are removed, can obtain remaining axis system homogeneity off-centre, with the eccentric data measuring and calculating of the homogeneity of this axis system and identify, just can use any one tire of uniformity test device to carry out uniformity test, the test radial force or the side force that obtain only are the stressed formation of detected tyre, are comparatively pure and measurement result accurately.

The measuring method of described removal tyre uniformity test device systematic eccentricity is installed on a standard tire on the axis system, and tire and axis system with permanent rotating speed forward and reverse rotation, are just changeed radial force value RF to record _f(1, i) (i=1,2 ..., m), just changeing side force value LF _f(1, i) (i=1,2 ..., m), counter-rotating radial force value RF _Cf(1, i) (i=1,2 ..., m), counter-rotating side force value LF _Cf(1, i) (i=1,2 ..., m);

Tire is rotated 360 °/n (n is an even number, and the number of times for measuring) on axis system, repeat the above-mentioned actual measurement power that rotates and reverse value, measure and record data until n time to tire;

The result who measures for n time carried out the stack of n point and ask on average, then measure and calibrate, meet following expression formula by the caused eccentric parameter of the intrinsic unevenness of above-mentioned axis system:

Just changeing radial force off-centre is,

${\mathrm{RF}}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}R{F}_f(j,i)(i=\mathrm{1,2},\·\·\·,m);$

Counter-rotating radial force off-centre is,

$R{F}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}R{F}_{\mathrm{cf}}(j,i)(i=\mathrm{1,2},\·\·\·,m);$

Just changeing side force off-centre is,

$L{F}_a\left(i\right)\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}L{F}_f(j,i)(i=\mathrm{1,2},\·\·\·,m);$

Counter-rotating side force off-centre,

$L{F}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}L{F}_{\mathrm{cf}}(j,i)(i=\mathrm{1,2},\·\·\·,m);$

In the uniformity test process of reality, the just commentaries on classics radial force that records by sensor, just change after side force, counter-rotating radial force and the counter-rotating side force data, the eccentric data of the axis system that deducts above-mentioned measurement respectively and calibrate, promptly deduct just changeing radial force off-centre, just change side force off-centre, the counter-rotating radial force is eccentric and counter-rotating side force off-centre, just can obtain that sensor records, by the caused parameter value of tire unevenness.

The measuring method of described removal tyre uniformity test device systematic eccentricity, employed tire uniformity measurement device, the shell of its main shaft do not rotate and have the strong point, so that main shaft is in unsettled and semi-free state; Sensor is close on the shell of main shaft, to detect the vibration situation of main shaft; The axis of loading wheel remains parallel with the axis of main shaft;

Described sensor is a heterogeneous sensor, can measure simultaneously tire radially with side direction on stress data;

Described rotary encoder is used for sending equably at each rotation period the pulse of fixed number.

Content to sum up, the described advantage that scaling method had that is applied to tyre uniformity test is, improve the accuracy of result of calculation, homogeneity correction for tire has direct directive function, the reason that produces amount of unbalance for tire is analyzed, improve tire quality, theoretical foundation is provided, thereby correspondingly improved tire checking efficient, reduced production cost.

Description of drawings

Now the present invention is described further in conjunction with the accompanying drawings:

Fig. 1 is the device synoptic diagram that carries out uniformity test of tire;

Embodiment

Embodiment 1, and as shown in Figure 1, described tyre uniformity test device comprises that one is rotatably supported in one by the main shaft 1 in the main shaft housing of non-yielding prop, and described tire 4 is fixedly mounted on the described main shaft; And loading wheel 5 that the simulation tire ground is exerted pressure to detected tyre.

In process of the test, loading wheel contact wheel tire tread applies certain pressure to tire 4, and tire and main shaft rotate by the friction force that acts on the tire by loading wheel; At least 1 heterogeneous piezoelectric force transducer 6 is installed on the main shaft housing.

Wherein, the shell of main shaft 1 does not rotate and has the strong point, so that main shaft 1 is in unsettled and semi-free state.

In the tire uniformity measurement process, small vibration can take place in main shaft 1, and sensor 6 is close on the shell of main shaft 1, and sensor 6 will detect the vibration situation of main shaft.

Remove the main shaft portion of shell, comprise that wheel rim 3 can freely rotate.Upper and lower wheel rim is in order to the wheel hub of simulation wheel, and plays the clamping tire, prevents the effect of losing heart behind the inflation of tire.

It is parallel that the axis of loading wheel 5 and the axis of main shaft 1 remain, and the material of loading wheel 5 is even, and symmetrical geometry can move horizontally left and rightly.

In test, loading wheel 5 simulation ground also apply for main shaft 1 and necessarily load with lotus, are equivalent to the pressure that car body forms tire 4 in tire 4 driving process.

Sensor 6 is a heterogeneous sensor, promptly can measure radial force and the side force of tyre side on (it is axial to be parallel to main shaft) on the tire radial direction (perpendicular to main-shaft axis) simultaneously, and can provide the both direction measurement data simultaneously.

In following content, when sensor 6 is finished and during the outputting radial data, is referred to as radial transducer; Finish and outgoing side during when sensor 6, be referred to as the side direction sensor to data.Sensor 6 can be one or more.

Rotary encoder 7, be used for sending equably the pulse of fixed number at each rotation period, utilize the equal angles of scrambler 7, this characteristic of pulse of sending at interval, just can reach equal angles, compartment of terrain data sampling, guarantee in each rotation period to sensor 6 signals sampling it is uniform.

Upper and lower wheel rim overlaps with the axis of main shaft 1, and following wheel rim 2 is an one with main shaft 1, last wheel rim 3 be upper and lower can be free-moving.

Go up wheel rim 3, loading wheel 5 before the test away from main shaft, be in origin position separately respectively.During test, tire 4 is loaded into down on the wheel rim 2, and last wheel rim 3 descends.

Upper and lower wheel rim is oppositely arranged and is locked, with clamping tire 4.Tire 4 is inflated, and made tire 4 internal pressures keep constant.Tire 4 relies on charge pressures and upper and lower wheel rim to fix, and like this in the main axis rotation process, the relative dislocation of tire 4 and upper and lower wheel rim can not take place.

Loading wheel 5 flatly near and contact tire 4, tire 4 is applied a constant pressure, loading wheel 5 is with uniform rotation, tire 4 under the friction force of loading wheel 5 also with uniform rotation.

Because main shaft 1 is constant with the relative position of tire 4, then main shaft 1 rotates with same angular velocity with tire 4.

In each rotation period, scrambler 7 sends the pulse of fixed number equably, whenever sends pulsatile once, the signal that computer recording is once exported by sensor 6.

After several rotation periods, loading wheel is with same rotating speed backward rotation, and tire is the constant speed counter-rotating under loading wheel drives.In each rotation period, scrambler evenly sends the pulse of fixed number, whenever sends pulsatile once, the signal that computer recording is once exported by sensor.

After several rotation periods, loading wheel and tire stop operating, and bleed a tire, and last wheel rim and loading wheel level return to reset position, and all data that collect are calculated to obtain every uniformity index of detected tyre, finish inhomogeneity test.

The measuring method of described removal tyre uniformity test device systematic eccentricity, when being installed on detected tyre on the main shaft, can be repeatedly by 180 ° of rotation detected tyres, to record form right radial force or side force measured values more.And this many group radial forces or side force measured value are the radial force of axis system and detected tyre and the value of closing of side force.

For same detected tyre, by the many compositions that draw after 180 ° of rotations right radial force or side force numerical value, all have equal and opposite in direction, characteristic that direction is opposite, promptly making a concerted effort is zero, just aggregate value is zero.

As long as many combining abilities that above-mentioned detected tyre produces are removed, can obtain remaining axis system homogeneity off-centre, with the eccentric measuring and calculating of the homogeneity of this axis system and identify, just can use any one tire of uniformity test device to carry out uniformity test, the test radial force or the side force that obtain only are the stressed formation of detected tyre, are comparatively pure and measurement result accurately.

The measuring method of described removal tyre uniformity test device systematic eccentricity has following steps:

The first step is got a standard tire and is placed on main measurement unit and is installed on the axis system, inflates; Loading wheel is by the close tire of origin position, and the contact wheel tire tread, and tire is applied constant force load;

Loading wheel is by certain rotational speed, thereby driving tire and axis system is rotated in the forward with permanent rotating speed, rotary encoder evenly sends the pulse of m point in each rotation period, (this fixed angle can be used as the zero point that main shaft rotates to some fixed angles when main axis rotation, this null position can be discerned by rotary encoder) time, rotary encoder whenever sends a pulse, and computing machine is just gathered the numerical value of radial transducer and side direction sensor, is recorded as respectively

RF _f(1，i) (i＝1，2，…，m)

LF _f(1，i) (i＝1，2，…，m)

Just changeing to measure and finish, loading wheel drives tire and main shaft backward rotation, and when the main shaft angle reached null position, rotary encoder whenever sent a pulse, and computing machine is just gathered the numerical value of radial transducer and side direction sensor, is recorded as respectively

RF _cf(1，i) (i＝1，2，…，m)

LF _cf(1，i) (i＝1，2，…，m)

Data acquisition finishes, and loading wheel stops the rotation, and returns to origin position, bleeds a tire, and last wheel rim rises;

In second step, tire is rotated 360 °/n (n is an even number, and the number of times for measuring, practical application general n≤10) on axis system;

Repeat above-mentioned first step operation, last wheel rim descends, be installed tire and inflation, and inner gas pressure remains unchanged, and loading wheel contact wheel tire tread also applies permanent load, repeats the action and the data acquisition of above-mentioned steps 1, and writes down positive revolution respectively according to being

RF _f(2，i) (i＝1，2，…，m)

LF _f(2，i) (i＝1，2，…，m)

Reversal data is

RF _cf(2，i) (i＝1，2，…，m)

LF _cf(2，i) (i＝1，2，…，m)

Repeat above-mentioned action, until n time is measured;

The 3rd step, the eccentricity values of measuring and calculating axis system;

The result of n measurement is carried out the stack of n point and asks average, and formula is as follows:

Just changeing radial force off-centre: $R{F}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}R{F}_f(j,i)$ (i＝1，2，…，m)

Counter-rotating radial force off-centre: $R{F}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}R{F}_{\mathrm{cf}}(j,i)$ (i＝1，2，…，m)

Just changeing side force off-centre: $L{F}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}L{F}_f(j,i)$ (i＝1，2，…，m)

Counter-rotating side force off-centre: $L{F}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}L{F}_{\mathrm{cf}}(j,i)$ (i＝1，2，…，m)

Above-mentioned just changeing radial force off-centre, just change side force off-centre, the counter-rotating radial force is eccentric and counter-rotating side force off-centre, is the caused eccentric data by the intrinsic unevenness of axis system.

In the uniformity test process of reality, the just commentaries on classics radial force that records by sensor, just changeing side force, after counter-rotating radial force and the counter-rotating side force data, the eccentric data of the axis system that deducts above-mentioned measurement respectively and calibrate, promptly deduct and just changeing radial force off-centre, just changeing side force off-centre, eccentric and the counter-rotating side force off-centre of counter-rotating radial force, just can obtain that sensor records, by the caused parameter value of tire unevenness, thereby improve the accuracy of result of calculation greatly, homogeneity correction for tire has direct directive function, the reason that produces amount of unbalance for tire is analyzed, improve tire quality, theoretical foundation is provided.

Claims (3)

1. measuring method of removing tyre uniformity test device systematic eccentricity is characterized in that: a standard tire is installed on the axis system, tire and axis system with permanent rotating speed forward and reverse rotation, are just changeed radial force value RF to record _f(1, i) (i=1,2 ..., m), just changeing side force value LF _f(1, i) (i=1,2 ..., m), counter-rotating radial force value RF _Cf(1, i) (i=1,2 ..., m), counter-rotating side force value LF _Cf(1, i) (i=1,2 ..., m);

Wherein, tire is just transferring to and rotating counterclockwise, and is reversed to clockwise rotate;

With 360 °/n of axis system rotation (n is an even number, and the number of times for measuring), repeat the above-mentioned actual measurement power that rotates and reverse value to tire, measure and record data until n time;

The result who measures for n time carried out the stack of n point and ask on average, then measure and calibrate, meet following expression formula by the caused eccentric parameter of the intrinsic unevenness of above-mentioned axis system,

Just changeing radial force off-centre is,

${\mathrm{RF}}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{RF}}_f(j,i)(i=\mathrm{1,2},...,m);$

Counter-rotating radial force off-centre is,

${\mathrm{RF}}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{RF}}_{\mathrm{cf}}(j,i)(i=\mathrm{1,2},...,m);$

Just changeing side force off-centre is,

${\mathrm{LF}}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{LF}}_f(j,i)(i=\mathrm{1,2},...,m);$

Counter-rotating side force off-centre,

${\mathrm{LF}}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{LF}}_{\mathrm{cf}}(j,i)(i=\mathrm{1,2},...,m).$

2. the measuring method of removal tyre uniformity test device systematic eccentricity according to claim 1, it is characterized in that: employed tire uniformity measurement device, the shell of its main shaft does not rotate and has the strong point, so that main shaft is in unsettled and semi-free state; Sensor is close on the shell of main shaft, to detect the stressing conditions of main shaft; The axis of loading wheel remains parallel with the axis of main shaft;

Described sensor is a heterogeneous sensor, with measure simultaneously tire radially with side direction on stress data;

Described rotary encoder is used for sending equably at each rotation period the pulse of fixed number.

3. the measuring method of removal tyre uniformity test device systematic eccentricity according to claim 1 and 2 is characterized in that: have following performing step,

The first step is got a standard tire and is placed on main measurement unit and is installed on the axis system, inflates; Loading wheel is by the close tire of origin position, and the contact wheel tire tread, and tire is applied constant force load;

Loading wheel is by certain rotational speed, thereby driving tire and axis system is rotated in the forward with permanent rotating speed, rotary encoder evenly sends the pulse of m point in each rotation period, when 360 °/m of the every rotation of main shaft, rotary encoder sends a pulse, computing machine is just gathered the numerical value of radial transducer and side direction sensor, is recorded as RF respectively _f(1, i) (i=1,2 ..., m), LF _f(1, i) (i=1,2 ..., m);

Just changeing to measure and finishing, loading wheel drives tire and main shaft backward rotation, and when the main shaft angle reached null position and main shaft and reaches the rotating speed of regulation, rotary encoder whenever sent a pulse, computing machine is just gathered the numerical value of radial transducer and side direction sensor, is recorded as RF respectively _Cf(1, i) (i=1,2 ..., m), LF _Cf(1, i) (i=1,2 ..., m);

Data acquisition finishes, and loading wheel stops the rotation, and returns to origin position, bleeds a tire, and last wheel rim rises;

In second step, tire is rotated 360 °/n (n is an even number, and the number of times for measuring) on axis system;

Repeat above-mentioned first step operation, last wheel rim descends, be installed tire and inflation, and inner gas pressure remains unchanged, and loading wheel contact wheel tire tread also applies permanent load, repeats the action and the data acquisition of above-mentioned steps 1, and writes down positive revolution respectively according to being RF _f(2, i) (i=1,2 ..., m), LF _f(2, i) (i=1,2 ..., m);

Reversal data is RF _Cf(2, i) (i=1,2 ..., m), LF _Cf(2, i) (i=1,2 ..., m);

Repeat above-mentioned action, until n time is measured;

The 3rd step, the eccentricity values of measuring and calculating axis system;

The result of n measurement is carried out the stack of n point and asks average,

Just changeing radial force off-centre: ${\mathrm{RF}}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{RF}}_f(j,i)$ (i＝1，2，…，m)

Counter-rotating radial force off-centre: ${\mathrm{RF}}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{RF}}_{\mathrm{cf}}(j,i)$ (i＝1，2，…，m)

Just changeing side force off-centre: ${\mathrm{LF}}_a\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{LF}}_f(j,i)$ (i＝1，2，…，m)

Counter-rotating side force off-centre: ${\mathrm{LF}}_{\mathrm{ca}}\left(i\right)=\frac{1}{n}\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{\mathrm{LF}}_{\mathrm{cf}}(j,i)$ (i＝1，2，…，m)。