Uniformity rectifier

2019-06-11 17:31:43

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Uniformity rectifier

 

01

Uniformity


Tire uniformity has a direct impact on vehicle handling stability and driving safety. Modern road traffic and automobile industry have increasingly higher requirements on tire uniformity and excellent performance. Improvement on pass rate of the tire making has no doubt in bring more profits for the tire manufacturer.

 


Tire uniformity test indicators include RFV(RADIAL FORCE VARIATION), RFV  1ST HAR., LFV(LATERAL FORCE VARIATION), RRO(Radial Run Out), LRO(Lateral Run Out), BPS(Bumpy Side).

 


In general, four indicators :RFV;  LFV; CONY; CRRO are need to be controlled well.

02


RFV(RADIAL FORCE VARIATION):


When a certain appropriate load is applied to the tire, the distance between the center of the tire and the center of the loadwheel is kept constant, and when the force of the radial direction changes, the waveform is generally obtained as shown in the figure. The difference between the highest and lowest points is called RFV and the unit is kgf.

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RFV  1ST HAR.

When the tire rotates one revolution, the highest point on the radial force-based harmonics is marked with red dots on the tire.

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03

Reasons for causing RFV/RFV1

 

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04

Solution-Uniformity rectifier


When the tire uniformity test fails, under the traditional technology,The current simillar machine reducing RFV and RFV1H value by polishing tire shoulder and local heating would cause damage to tire appearance, reduce tire quality and affect tire sales.


a new solution - tire uniformity rectifier that avoids adverse effects on tire appearance and other performance, reduces RFV and RFV1H values, improving tire uniformity, and reducing rejection rate.

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After the rectification, the RFV and RFV1H values of tires can be reduced by 2.5~3.5kgf 

 

Item

Parameters

Tire specifications

16〞—24

Outer diameter

500mm≤D≤1300mm

Section width

140mm≤B≤400mm

QTY of tire loading

Max.4

Dimension

L4000*W1700*H2350

Weight

2T

 

05

Eqiupment Highlights

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◆Zero damage to tires: There is no side-effect on appearance and internal parts.

◆Reduced RFV and RFV1H - has no effect on other values

◆Fully automatic rectification: 10 machines could be operated by only one operator.

◆Reduce Planned production and inventory

◆Reduce in the number of rejects 

◆Small area occupied and independent control

◆High ROI (return on investment): Only 6 months are needed for Cost-recovering

06 Working principle


Get the tire bead rectified to a proper concentricity and reduce the RFV and RFV1H values by stretching and pressurizing the tire bead and by heating it regularly

 

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By comparing the waveforms before and after correction, it can be seen that the waveform shape changes little and the amplitude changes obiviously.

07

Experimental data

01

A  205/55R16

 

 


The average change of RFV1H value  for 30 pieces of tire is 3.57kgf.

02

 195/60R16

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The average change of radial force RFV value  for 36 pieces of tire is 3.43kgf.

03

C轮胎   225/60R18

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The average change of radial force RFV value is 2.5kgf;

The average change of RFV1 value is 4kgf.

 Normal Quantie Plot for value of RFV、RFV1H after and before the rectification.

 

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2.5~3.5kgf 

After the rectification, the RFV and RFV1H values of tires can be reduced by 2.5~3.5kgf.

08

Test data shows

1After many experiments and tests, the rectification has no significant effect on tire LFV, LFV1H CONY dynamic balance and so on.

2According to the bead tripping, strength, hydraulic blasting, durability, low pressure, high speed test, tire performances before and after rectificion are basically the same

3The measured values of RFV and RFV1H after correction do not rebound and can maintain a stable state.

4There is no side-effect on tire ppearance and internal parts.