JPS63142228A - Method of balancing pneumatic tire for passenger car - Google Patents

Abstract

PURPOSE:To suppress the increase in radial runout (RR) at the time of high speed rotation and to prevent the deterioration of high speed uniformity, by taking balance by a tire alone. CONSTITUTION:At first, the unbalance of a tire alone is measured to calculate the unbalance quantity of the tire and the position thereof. Then, a balance wt. having the same wt. as the unbalance quantity is adhered to the back surface of the tread of the tire at a position shifted by 180 deg. from the unbalance position. For example, when there is tire balance at position A, the position A becomes large in RR at a high speed because of centrifugal force of unbalance and high speed uniformity become large. When the balance wt. is adhered to a position B shifted by 180 deg. from the position A, the unbalance force actinging on the whole of the tread is cancelled and the increase in RR can be prevented at a high speed. By this method, the increase in high speed uniformity causing high speed vibration can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for improving the balance in a single pneumatic tire for a passenger car.

This invention relates to a method for reducing vibrations and the like.

(Prior art) Pneumatic tires for passenger cars are manufactured through various manufacturing processes, but due to errors in manufacturing methods and errors in dimensions and weight of materials used in each process, there is a certain degree of unbalance. is unavoidable.

Therefore, as a countermeasure against this unbalance, it is necessary to eliminate this unbalance when using tires, including vibration problems.

Therefore, a balancing method using an off-the-car balancer is currently being implemented.

This method involves attaching the tire to the rim on a balancer as shown in Figure 1, measuring the unbalanced force when idling, and then canceling this unbalanced force as shown in Figure 2. In addition, balance weights (usually made of lead) were attached to the front and back of the rim flange to the rim 7 lunge using a balancing method (dynamic balance method).

However, even if this method is implemented, vibration problems that are considered to be caused by unbalance occur, and improvements in the balancing method have been desired.

(Problems to be Solved by the Invention) The unbalance of a normal pneumatic tire mainly occurs in the tread portion. For this reason, even if the conventional method of balancing is done by attaching weights to the rim flange, the tire cannot be balanced.

Therefore, when the tires shift at high speed, this unbalanced portion protrudes, resulting in radial runout (hereinafter referred to as RR).
) increases, and high-speed uniformity also increases.

As described above, although the conventional balance method can cancel the centrifugal force due to unbalance, it cannot prevent the increase in RR due to unbalance. Therefore, the conventional balance method alone is not sufficiently effective against high-speed vibration.

(Means for solving the problem) This is due to the fact that the conventional balancing method uses a weight on the rim flange to achieve balance, so the tire itself is not balanced.

Therefore, in the present invention, by balancing the tire alone, the increase in radial runout RR is suppressed even during high-speed transfer, and the deterioration of high-speed uniformity is prevented.

In a method for balancing a pneumatic passenger car tire in which a pneumatic passenger car tire is combined with a wheel, a balance weight of the same weight as the amount of unbalance is placed at a position offset by 180' from the unbalanced position of the pneumatic passenger car tire alone. This is a method of balancing a pneumatic passenger car tire by gluing it to the back of the tire tread, then assembling the tire to the rim and using an off-the-car balancer to correct the dynamic imbalance as a tire assembly. Measures the static unbalance of a single unit and determines the amount of tire unbalance and its position. A balance weight with the same weight as the amount of unbalance is glued to the back side of the tread at a position 180 degrees offset from the unbalance position. This balance weight may be made of rubber or adhesive tape, and the adhesive used is a material that can withstand long-term high-speed running.

As a result of the above, the tire itself has been balanced. Next, before actually mounting the tire on the vehicle, balance it using a conventional off-the-car balancer. This is mainly to remove the imbalance of the rim.

(Function) In Fig. 3, if there is a tire unbalance at the A position, when the speed increases, the radial runout becomes large due to the unbalanced centrifugal force at the A position, and the RFV has high speed uniformity.
, TFV will both increase. Here, in the present invention, since the balance weight is pasted at position B, which is 180 degrees offset from position A shown in Fig. 4, the unbalanced force acting on the entire tread is canceled, thereby preventing an increase in radial runout even at high speeds. becomes possible. This results in high-speed uniformity, R, which is the cause of high-speed vibration.
It is possible to suppress increases in FV and TFV.

Next, as shown in FIG. 5, the tire is attached to the rim, and an off-the-car balancer is used to measure and correct the imbalance between the tire and the rim.

(Example) A case where the conventional balancing method is applied to a tire having an imbalance as shown in Fig. 1, that is, only the method of loading a weight on the rim 7 lunge Fig. 2 A case where the balancing method of the present invention is carried out Measure the high-speed uniformity when carrying out the procedure shown in Fig. 5.

The effectiveness of the present invention is confirmed by the method shown in FIG. The test conditions are as follows.

Tire: PSR175/709R13 drum direct:
2000mm drum transfer speed: 15Ok layers/h Tire load: 345kg Measurement, 11: RFV (Radial force variation) TFV (Tangential force variation) As shown in Figure 7, the measured amount RFV, TFV is evaluated by the peak-to-peak value of one blow component of tire rotation.

(Effects) As shown in FIG. 8, when the balance method of the present invention is performed, the speed dependence of RR becomes smaller compared to the conventional method. As a result, as shown in Figures 8 and 10, the high-speed uniformity RFV
The value of TFV, especially at high speeds, was smaller than that of the conventional method alone, proving that the present invention is an effective balance method for countering high-speed vibrations.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the unbalance position of a conventional pneumatic tire for a passenger car, which was measured for unbalance. FIG. 2 shows the unbalance position of a conventional pneumatic tire for a passenger car where the unbalance was measured, and at the same time shows a balance weight attached to the rim flange. FIG. 3 is a diagram showing the state in which the tire protrudes when the balance of only a pneumatic tire for a passenger car is measured and the tire is rotated at high speed in an unbalanced position. FIG. 4 is a diagram in which the balance of only the pneumatic tire for a passenger car of the present invention was measured, and A shows the unbalanced position, and B shows a balance weight adhered to the back surface of the tread at a position shifted by 1806 points of the tire. Figure 5 shows that the balance of only the pneumatic tire for a passenger car of the present invention is corrected, and then the balance is measured after mounting it on the rim.
It is a diagram in which the balance between the two was measured and a balance weight was attached to the unbalanced position. 8th rl! J is a diagram of a method for measuring RFV, ↑FV, in order to evaluate the effect of the balancing method for a pneumatic tire for a passenger car according to the present invention. Figure 7 shows RFV and TFV measured using the method shown in Figure 6.
, is a diagram of one blowing component when the tire rotates once. 8th. 8th. FIG. 10 is a diagram showing the effect of the balancing method for a pneumatic tire for a passenger car according to the present invention. FIG. 3 is a diagram showing the speed dependence of RFV and TFV. Patent applicant Brideston Co., Ltd. Figure 1 Weight Figure 3 Figure 4 Figure 5 Balance method of the present invention Figure 8 Speed dependence of RH 5PEED (at M/l-13

Claims (1)

[Claims] In a method for balancing a pneumatic tire for a passenger car in which the pneumatic tire for a passenger car is combined with a foil, the amount of unbalance is determined at a position offset by 180 degrees from the unbalance position of the pneumatic tire for a passenger car alone. A pneumatic tire for a passenger car is balanced by bonding a balance weight of the same weight to the back side of the tire tread, and then the tire is assembled to a rim, and an off-the-car balancer is used to correct the dynamic imbalance as a tire assembly. How to balance pneumatic tires for passenger cars.