JP6611077B2 - FV measuring apparatus and FV measuring method - Google Patents

Description

  The present invention relates to an FV measuring apparatus and an FV measuring method for measuring FV of a pneumatic tire.

  In the production process of pneumatic tires, force variation (FV: Force Variation) that indicates fluctuations in load due to tire rigidity and dimensional non-uniformity is measured for quality control of product tires. (Patent Document 1).

  FIG. 3 is a diagram schematically showing a conventional FV measuring apparatus. As shown in FIG. 3, in the FV measuring device 50, after the tire T is held by the pair of rims 52, 54 and the tire T is filled with air and inflated to a predetermined internal pressure, The FV is measured by rotating the tire T in the freight state with the road wheel 58 around the axis L of the spindle 56. At this time, since the pressing state of the tire T by the road wheel 58 changes due to increase / decrease of the tire internal pressure (inflation pressure), it is necessary to keep the tire internal pressure constant during the FV measurement.

JP 2010-185709 A

  However, there are cases where air leaks from the tire T rotating in contact with the road wheel 58 and the tire internal pressure changes. Therefore, conventionally, the tire internal pressure is maintained by continuously supplying air into the tire T against this air leakage. However, if the amount of air leakage increases, the tire internal pressure cannot be maintained, and the FV measurement result. May cause inaccurate measurement results.

  Accordingly, the present invention provides an FV measuring apparatus and an FV measuring method capable of preventing an inaccurate measurement result from being obtained due to an increase in the amount of air leakage in FV measurement of a product tire. And

The invention described in claim 1
An FV measuring device that fills air into a tire held by a pair of upper and lower rims and measures the FV of the tire in a state where the tire is inflated,
A flow meter for measuring a flow rate of air supplied into the tire is provided in an air supply pipe for supplying the air into the tire,
Furthermore, when the measurement result of the air flow rate by the flow meter exceeds a predetermined threshold, determination means is provided for determining that air leakage has occurred from the tire,
In the FV measuring apparatus, the predetermined threshold value is a fluctuation threshold value that reflects a flow rate measured in the past of the tire of the same size.

The invention described in claim 2
2. The FV measuring apparatus according to claim 1, further comprising a stopping unit that stops the FV measurement of the tire when the determining unit determines that the air leakage has occurred. is there.

The invention according to claim 3
An FV measurement method for performing FV measurement of a tire using the FV measurement device according to claim 1 or 2,
Using the flow meter, measure the flow rate of air supplied to the tire during FV measurement,
When the measurement result of the air flow rate by the flow meter exceeds a predetermined threshold, it is determined that an air leak has occurred from the tire.

The invention according to claim 4
The FV measurement method according to claim 3, wherein the FV measurement of the tire is stopped when it is determined that the air leakage has occurred during the FV measurement of the tire.

  ADVANTAGE OF THE INVENTION According to this invention, the FV measuring apparatus and FV measuring method which can prevent that an inaccurate measurement result is obtained by the amount of air leaks increasing can be provided.

It is a figure which shows typically the FV measuring apparatus which concerns on one embodiment of this invention. It is a figure which shows typically the FV measuring apparatus which concerns on one embodiment of this invention. It is a figure which shows the conventional FV measuring apparatus typically.

  The present embodiment will be described below with reference to the drawings.

1. Configuration of FV Measuring Device According to this Embodiment FIGS. 1 and 2 are diagrams schematically showing an FV measuring device according to this embodiment. Specifically, FIG. 1 is a view showing a state in which an air leak F occurs between the rims 12 and 14 and the tire T, and FIG. 2 shows an air leak F generated from a hole formed in the tire T. It is a figure which shows a state.

  As shown in FIGS. 1 and 2, the FV measurement device 10 according to the present embodiment is held by a pair of upper and lower rims 12 and 14 that hold a tire T to be measured, and the rims 12 and 14, as in the past. A spindle 16 that rotates the tire T, and a road wheel (not shown) that presses the inflated tire T during FV measurement.

  An air supply pipe 20 that supplies air into the tire T is connected to the upper rim 12, and the tire T is inflated by supplying air from the air supply pipe 20 into the tire T. The configuration so far is the same as that of the conventional FV measuring apparatus.

  However, in the present embodiment, the above-described air supply pipe 20 is provided with a flow meter 22 for measuring the flow rate of the air supplied into the tire T, and further the air flow rate measured by the flow meter 22 is measured. The measurement result is compared with a predetermined threshold value, and is different from the conventional one in that determination means 30 is provided for determining whether or not an air leak F has occurred from the tire T based on the result.

  In general, the air leak F from the tire T may be a mechanical factor or a tire factor, and since it is unclear at which position it is occurring, the vicinity of the location where the air leak has occurred It is difficult to detect the occurrence of air leak directly.

  For this reason, in this Embodiment, the flowmeter 22 is provided in the air supply piping 20 by the side of an air supply, and the flow volume of the supplied air is measured in order to maintain a tire internal pressure with respect to an air leak. In addition, the flowmeter 22 can use the apparatus which measures a general air flow rate, and is not specifically limited.

  The determination unit 30 compares the air flow rate measured by the flow meter 22 with a threshold value, determines that normal FV measurement cannot be performed when the measured value exceeds the threshold value, and sounds an alarm to give the operator an alarm. Is configured to prompt the stop of the FV measurement.

2. FV Measurement Method According to the Present Embodiment Next, an FV measurement method using the above-described FV measurement device 10 will be described. The basic measurement method is the same as the conventional FV measurement method.

  First, after attaching the tire T to the pair of rims 12 and 14 of the FV measuring device 10, the tire T is inflated by filling the tire T with air from the air supply pipe 20. Then, the road wheel (not shown) is brought into contact with the tire T, and the road wheel is pressed against the tire T until the load set value is reached.

  In this state, the tire T is rotated about the axis L of the spindle 16 to measure FV. At this time, FV measurement is performed while supplying air into the tire T so that the internal pressure of the tire T is maintained at the set pressure. The steps so far are the same as in the prior art.

  However, in the present embodiment, the flow rate of air supplied during the FV measurement described above is measured by the flow meter 22, and the determination unit 30 compares the flow rate of air measured by the flow meter 22 with a threshold value. It is determined whether or not the air flow rate is normal, and this is not done conventionally.

  If the amount of air leakage from the tire T is large in the FV measuring device, the amount of air supplied increases in order to maintain the internal pressure of the tire T, and therefore the measured value by the flow meter 22 becomes larger than usual. And when this measured value exceeds a threshold value, a determination means determines with it being abnormal. Then, an alarm indicating that an abnormality has occurred is sounded to prompt the operator to stop the FV measurement.

  As described above, according to the present embodiment, the amount of air leakage F is detected by measuring the flow rate of air supplied to the tire T during FV measurement. Since it can be stopped, it is possible to prevent an inaccurate measurement result from being obtained due to fluctuations in tire internal pressure due to a large amount of air leakage.

  Further, in the present embodiment, the flow rate of air supplied to the tire is measured, and it is possible to estimate the abnormal content from the amount of the flow rate. For example, when the tire has a hole or a nonstandard tire is mounted, the air supply amount tends to increase.

  Note that, as the threshold value set in the determination unit 30, it is preferable to employ a fluctuation threshold value that varies reflecting the flow rate measured in the past. Depending on the size, the tire T may be easy to inflate or may be difficult, and even tires of the same size have individual differences. For this reason, by adopting the above-described variation threshold and setting a threshold reflecting the past flow rate of the same size, it is possible to detect air leakage from the tire under an appropriate threshold.

  Further, in the above-described embodiment, when the determination unit 30 determines that a large amount of air leakage has occurred, an alarm is sounded to prompt the operator to stop the FV measurement. For example, the FV measurement may be automatically stopped.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to said embodiment. Various modifications can be made to the above-described embodiment within the same and equivalent scope as the present invention.

10, 50 FV measuring device 12, 14, 52, 54 Rim 16, 56 Spindle 20 Air supply pipe 22 Flow meter 30 Judging means 58 Road wheel F Air leak T Tire L Spindle shaft

Claims (4)

An FV measuring device that fills air into a tire held by a pair of upper and lower rims and measures the FV of the tire in a state where the tire is inflated,
A flow meter for measuring a flow rate of air supplied into the tire is provided in an air supply pipe for supplying the air into the tire,
Furthermore, when the measurement result of the air flow rate by the flow meter exceeds a predetermined threshold, determination means is provided for determining that air leakage has occurred from the tire,
The FV measuring apparatus, wherein the predetermined threshold value is a fluctuation threshold value that changes in accordance with a flow rate measured in the past of a tire of the same size.   2. The FV measurement device according to claim 1, further comprising a stop unit that stops the FV measurement of the tire when the determination unit determines that the air leakage has occurred. An FV measurement method for performing FV measurement of a tire using the FV measurement device according to claim 1 or 2,
Using the flow meter, measure the flow rate of air supplied to the tire during FV measurement,
An FV measurement method, wherein when the measurement result of the air flow rate by the flow meter exceeds a predetermined threshold, it is determined that air leakage has occurred from the tire.   The FV measurement method according to claim 3, wherein the FV measurement of the tire is stopped when it is determined that the air leakage has occurred during the FV measurement of the tire.

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