JPS6371340A - Correction of tire uniformity - Google Patents

Abstract

PURPOSE:To correct a tire once set with respect to many items at the same time, by pressing a drum to the rotating tire and measuring the rigidity of said tire by the load cell mounted on the shaft of the drum and performing wave form processing by a control apparatus and altering the angle of a grindstone to perform buffing processing. CONSTITUTION:The rigidity in an X-axis direction and that in a Y-axis direction of both shoulder parts of a tire W, a radial force variation (RFV), lateral force variation (LFV) and conicity are measured by X-and Y-load cells 3a, 3b and comparative operation is performed by a computer 5 and, when RFV and unicity are out of standards, the a-point position of the tire W is shaven by definite quantity. Thereafter, the shaving positions of rubstones 6a, 6b are altered and moved to the outside of the tire W to again perform shaping with respect to the same item. Next, when LFV is out of a standard, the first correction of RFV of the rigidity in the X-axis direction of both shoulder parts is performed and the grindstones 6a, 6b are moved to b-point positions at the second time to correct LFV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for correcting tire uniformity, and more particularly to an improvement in a method for correcting lateral force variation (LFV) of tire uniformity.

[Prior art]

One of the uniformity characteristics of a tire is, for example, the characteristics of tire rigidity, that is, the radial force variation of the tire (the variation of the force in the tire radial direction under the condition of the tire installation is called RF), the lateral force variation of the tire, and the lateral force variation of the tire. There are force variations (variations in the force in the width direction of the tire depending on the tire mounting condition; hereinafter referred to as LFV) and conicity force (the force that occurs when the tire is considered to be conical), and these RFV, In order to correct LFV and conicity, it is generally known that buffing the tire shoulder area is highly effective.

By the way, conventional RFV modification methods include, for example,
As disclosed in Japanese Patent No. 4-31239, there is a method of correcting the part where radial force (hereinafter referred to as RF, which refers to the crab in the tire radial direction in the tire mounting condition) is generated, and there is also a method similar to this. As a matter, Japanese Patent Application Laid-Open No. 1973-
83976, JP-A-54-129071, etc.

However, when modifying the conventional RFV, the LF
Since V is not taken into consideration, LFV may deteriorate, and when buffing is performed with the whetstone always in a constant state,
It was difficult to modify the LFV.

[Purpose of the invention]

This invention was devised by focusing on the conventional problems, and its purpose is to correct the uniformity of a tire by fixing a fixed position, especially in response to rigidity fluctuations occurring from the shoulder part of the tire. A tire uniformity correction method that allows you to correct multiple items at the same time on a set tire by changing the position of buffing with a grindstone, focusing on the fact that buffing only produces a certain effect. It is intended to provide a selection of

[Structure of the invention]

In order to achieve the above object, the present invention presses a drum against a rotating tire, and uses a load cell attached to a drum shaft that supports the drum to control the RFV, LFV, etc. of the tire.
The conicity and stiffness of the shoulder parts on both sides of the tire are measured, and each of these measured values is processed into a waveform by the control device. The gist of this method is to correct the LFV of a tire by operating a grindstone angle adjustment motor in response to a command, changing the angle of the grindstone, and performing buffing.

[Embodiments of the invention]

The present invention will be described in detail below based on the accompanying drawings.

FIG. 1 shows a schematic configuration diagram of a uniformity machine embodying the present invention, where W is a tire rotatably supported on a support shaft 1, 2 is a rotatable drum pressed against the tire W,
3a and 3b are X- mounted on both ends of the drum shaft 2a.
This X-Y load cell 3a shows a Y load cell (a sensor that converts a change in force into a change in voltage and outputs it).

3b, the stiffness in the X-axis direction (RF force direction components: Ax, Bx) and the stiffness in the Y-axis direction (LF force direction component: AY) of both shoulder parts Wl and W2 of the tire W.

By) and the data detected by shoulder stiffness detector 4 (
It is detected by the arithmetic device 4) and output to the computer 5 (control device 5).

In this calculator 5, the rigidity in the X-axis direction (RF force direction components: Ax, Bx), RFV, LFV.

Process the conicity waveform and calculate the shoulder stiffness (Ax, BX) l RFV, LFV from this calculator 5
, the (-) part of conicity is processed by grinding wheel 6 based on the waveform.
A signal is sent to the servo controllers 9a, 9b so that the positional deviation between a, 6b and the drum 2 is corrected, and the load current of the load current detectors 8a, 8b connected to the grindstone motors 7a, 7b is within a certain range at the buffing target location. is output and controlled via the grindstone feed motors 10a and 10b.

In addition, lla and llb in FIG. 1 are the grindstone motors 7a and 7b.
and the load current detectors 8a and 8b, and this grindstone angle adjustment motor lla
, llb are the data calculated by the computer 5 (rigidity in the X-axis direction (RF force direction components: Ax, Bx), RFV, LF
The tire W is buffed in the same foreground by changing the grinding wheel angle and changing the buffing position for the standard failure item (V, conicity). In addition, 12 is a whetstone 6a
, 6b is corrected by 11z, a motor for the front and rear stops of the entire device, 13 is a stopper, and 14 is a cylinder for front and rear of the main body of the device.

Next, a method for correcting tire uniformity will be explained.

First, the X-Y load cells 3a and 3b measure the rigidity of both shoulder parts -1 and -2 of the tire W in the X-axis direction (RF force direction components: Ax, Bx) and the Y-axis direction stiffness (LF force direction component: Ay, By), RFV, LFV, and conicity are measured, and the calculator 5 compares and calculates whether or not the measured values correspond to the standard to calculate the standard failure items, and the grinding wheel 6a,
6b determines the priority order of modifications.

First, if the first item such as RFV and conicity falls below the standard, after grinding the point a position in Fig. 2 by a certain amount, adjust the grinding position of the grinding wheels 5a and 5b, that is, the grinding angle. The motors 11a and llb are changed, moved to the outside of the tire, and grinding is performed again using the same items.

Next, if the second item of LFV is out of specification,
The first RFV correction of the rigidity in the X-axis direction of both shoulder parts -1 and -2 is carried out, and the second LFV correction is carried out by moving the grindstones 6a and 6b to the position of point b in Fig. 2. It is something.

As mentioned above, both shoulder parts of tire W -1,
The stiffness in the axial direction is measured, and if this measured value does not fall within the standard, the grinding wheel 5a is
, 5b are sequentially moved and buffed,
Once the tire W is set, RFV, LFV, and conicity can be corrected by simply moving and grinding the grindstones 5a and 5b.

〔Effect of the invention〕

This invention presses a drum against a rotating tire as described above, and uses a load cell attached to the drum shaft that supports the drum to measure the rigidity of the tire's RFV, LFV, conicity, and shoulder portions on both sides of the tire. The measured values are processed into waveforms by the control device, and if any of the above data is out of specification, the LFV
In this case, the LFV of the tire is corrected by operating the grinding wheel angle adjustment motor in response to a command from the control device to change the angle of the grinding wheel and performing buffing, which provides the following excellent effects. It is.

(a) Since the grinding position is simply changed, the remarkable effect of grinding several times with a constant grinding amount can be obtained.

(b) In order to change the cutting position, the RFV is corrected at the -th time, and multiple items can be corrected at the same time at the same time as the second LFV.

(C) Since LFV depends on the shape of the ground plane, grinding at the same location will only have a certain effect, but by changing the grinding position, the effect of grinding multiple locations can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a uniformity machine embodying the present invention, and FIG. 2 is an explanatory diagram of a uniformity correction method according to the present invention. 2...Drum, 2a...Drum shaft, 3a, 3b...
・X-yo-docel, 6a, 6b・-Whetstone, 11a. 11b... Grinding wheel angle adjustment motor, W... Tire, W
Lura 2... Shoulder part of the tire, Ax, Bx...
Rigidity in the X-axis direction (RF force direction component), Ay, By...
Stiffness in the Y-axis direction (LF force direction component).

Claims (1)

[Claims] A drum is pressed against a rotating tire, and a load cell attached to the drum shaft that supports the drum measures the tire's RFV, LFV, conicity, and stiffness at the shoulders on both sides of the tire. The waveform is processed by the control device, and if the standard failure item in the above data is LFV, the grindstone angle adjustment motor is operated according to the command from the control device to change the angle of the grindstone and perform buffing. Due to tire LFV
A method for correcting tire uniformity, characterized by correcting.