JP2001289730A - Air pressure leak detection device of pneumatic tire assembly, and air pressure leak detection method of pneumatic tire assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air pressure leak detection device of a pneumatic tire assembly, capable of detecting the leak of an air pressure accurately in a short time. SOLUTION: A dedicated valve adapter 62 is mounted on a valve 60 of the pneumatic tire assembly 58. A two-way valve 56 is opened to supply air to the pneumatic tire assembly 58 from a compressor 57. Thereafter the air pressure of the pneumatic tire assembly 58 is measured at prescribed intervals by a pressure sensor. Then, it is determined whether the measured air pressure of the pneumatic tire assembly 58 is in a prescribed range set by using the pressure before start of the measurement as a standard by a CPU. When the pressure is in the prescribed range, the absence of an air pressure leak is recognized, and when the pressure is out of the prescribed range, the existence of the air pressure leak is recognized. Hereby, a worker can decide on the existence of the air pressure leakage rapidly and accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire assembly air pressure leak detecting device and method for detecting pneumatic tire assembly air pressure leaks.

[0002]

2. Description of the Related Art In general, as a method of detecting air pressure leak of a pneumatic tire assembly (tire + wheel (rim)), a method of placing a pneumatic tire assembly in water and determining whether or not bubbles are generated. This was done by visually checking.

As another method, bubbles are continuously generated by applying an aqueous solution containing a surfactant (leak finder) or the like to a fitting portion of a rim and a tire, a valve mounting portion, or a valve. Whether or not it was confirmed visually.

[0004]

However, with the above method, it has been difficult to confirm accurately in a short time. That is, in the above method, it is necessary to detect a delicate air pressure leak that cannot be confirmed.

In view of the above, it is an object of the present invention to provide a pneumatic tire assembly air pressure leak detecting device and a pneumatic leak detecting method capable of detecting air pressure leaks in a short time and with high accuracy. I do.

[0006]

According to a first aspect of the present invention, there is provided a pneumatic tire assembly having a pneumatic tire assembly having a pneumatic tire assembly, wherein the pneumatic tire assembly has a pneumatic tire assembly. And determining means for recognizing that there is no air pressure leak when the measured air pressure is within a predetermined range based on the pressure before the start of measurement, and recognizing that there is no air pressure leak when the measured air pressure is not within the predetermined range. It is characterized by having.

Next, an apparatus for detecting pneumatic leakage of a pneumatic tire assembly according to claim 1 will be described.

According to this structure, the air pressure of the pneumatic tire assembly is measured by the measuring means connected to the pneumatic tire assembly. At this time, the air pressure may be measured only once, or may be measured a plurality of times over time. Then, the determining means determines whether or not the measured air pressure is within a predetermined range based on the pressure before the start of the measurement.

As a result, if the measured air pressure is within a predetermined range, it can be recognized that the air pressure of the pneumatic tire assembly is not leaking, and if it is not within the predetermined range, it can be recognized that the air pressure is leaking. Therefore, the leak of air pressure can be quickly and accurately recognized as compared with the conventional visual detection method.

According to a second aspect of the present invention, there is provided a pneumatic tire assembly pneumatic leak detecting apparatus for detecting at least one of the inside of the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the air temperature near the pneumatic tire assembly. A temperature measuring means for measuring the temperature of at least one of the temperature of the inside of the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the temperature of the air near the pneumatic tire assembly at the time of measurement;
(K) At least one of the temperatures of the air inside the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the air near the pneumatic tire assembly before the start of the measurement is set to T0.
(K) When the measured air pressure of the pneumatic tire assembly is PN, the air pressure PE after temperature correction is determined by the following equation: PE = T0 / TN × PN (1), and the air pressure PE after correction. Is to be determined by the determination means.

Next, an apparatus for detecting pneumatic leakage of a pneumatic tire assembly according to a second aspect will be described.

In general, Boyle-Charles' law is established as a relationship between the temperature and the pressure of a gas. This also applies to the air filled inside the pneumatic tire assembly. That is, as the temperature of the air increases, the air pressure also increases. Therefore, since the air pressure also changes with the temperature change at that time, if the temperature change is ignored, an accurate air pressure cannot be obtained.

Here, for example, the temperature inside the pneumatic tire assembly (air) is measured by the temperature measuring means, and the air pressure to be discriminated by the discriminating means is corrected by the above equation to obtain the air pressure due to the temperature change. Change can be canceled. As a result, the determination by the determining means as to whether or not there is an air leak is accurate.

According to a third aspect of the present invention, there is provided an apparatus for detecting pneumatic leakage of a pneumatic tire assembly, further comprising a display unit for displaying a determination result.

Next, a description will be given of a pneumatic tire assembly detecting apparatus according to a third aspect of the present invention.

According to this configuration, the result of the discrimination by the discriminating means is displayed on the display unit, so that the operator can recognize the result of the discrimination at a glance, and the speed of the operation can be improved.

According to a fourth aspect of the present invention, there is provided an air pressure leak detecting device for a pneumatic tire assembly, comprising alarm means for visually and / or audibly informing an operator when the air pressure is not within a predetermined range. It is characterized by the following.

Next, an apparatus for detecting pneumatic leakage of a pneumatic tire assembly according to a fourth aspect will be described.

According to this configuration, when the air pressure is not within the predetermined range, that is, when the air pressure is leaking, the operator is visually or audibly notified by alarm means such as a buzzer or a bell. Can be. This is effective when it is visually restricted at the work site, for example, when the display unit that displays the determination result by the determination unit is obstructed by an object or the like.

According to a fifth aspect of the present invention, there is provided a method for detecting a pneumatic tire assembly air pressure leak, comprising the steps of: inputting measurement conditions of the pneumatic tire assembly air pressure; Measuring at least one of the temperature of the air inside the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the air in the vicinity of the pneumatic tire assembly, and the pneumatic tire set at the time of measurement for the measurement result of the air pressure At least one of the temperature of the inside of the three-dimensional structure, the surface of the pneumatic tire assembly and the temperature of the air in the vicinity of the pneumatic tire assembly is defined as TN (K), and the inside of the pneumatic tire assembly before the measurement is started, the surface of the pneumatic tire assembly, and The temperature of at least one of the temperatures of the air near the pneumatic tire assembly is T0 (K), and the measured air pressure of the pneumatic tire assembly is In case of the N, the air pressure PE after temperature correction, PE = T0 / TN × PN ...... (2)
The temperature correction step determined by the air pressure after the temperature correction and the measurement conditions are compared, and if the air pressure after the temperature correction is within a predetermined range based on the pressure before the start of the measurement, there is no air pressure leak. A step of recognizing and, if not within a predetermined range, recognizing as air pressure leak.

Next, a description will be given of a method for detecting air pressure leakage of a pneumatic tire assembly according to a fifth aspect.

According to this method for detecting a pneumatic tire assembly pneumatic leak, first, in the setting step, how much time elapses after injecting the pneumatic tire assembly measurement conditions, for example, the pneumatic set value. For example, whether to start the measurement, how often the air pressure of the pneumatic tire assembly and the temperature at that time are measured, a predetermined range in which the measured air pressure is to be entered, and the like are input.

Next, in the measuring step, the air pressure of the pneumatic tire assembly and the temperature at that time are measured in accordance with the above-mentioned measuring conditions. At this time, the air pressure and the temperature may be measured only once, or may be measured a plurality of times over time.

Next, in the temperature correction step, the measured air pressure is temperature corrected by the above equation.

Next, in the determination step, if the temperature-corrected air pressure is within the predetermined range set in the setting step, it is recognized that there is no air pressure leak, and if not, the air pressure leak is recognized.

By recognizing the air pressure leak of the pneumatic tire assembly through each of the above steps, the operator can quickly and accurately determine whether or not the air pressure leak has occurred, as compared with the conventional visual detection method. can do.

[0027]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a pneumatic tire assembly according to an embodiment of the present invention. FIG. 1 is an overall configuration diagram of a device for detecting pneumatic leakage of a pneumatic tire assembly. FIG. 2 is a front view of a high-precision pressure measuring module constituting the air pressure leak detecting device, and FIG. 3 is a rear view thereof.

As shown in FIG. 1, a pneumatic tire assembly air pressure leak detecting device 10 (hereinafter simply referred to as a "detecting device 1
0 ". ) Is a high-precision pressure measurement module 12
(MU101, manufactured by Yokogawa Electric Corporation). The measurement range of the high-precision pressure measurement module 12 is 0 to 10
KPa (L range), 0 to 130 KPa (M range),
0 to 700 KPa (H range), 0 to 3 MPa (A range), and resolutions of 0.0008 KPa (L range), 0.003 KPa (M range), 0.03 KP
a (H range) and 0.06 KPa (A range).

As shown in FIG. 2, a keyboard 14 is provided in front of the high-precision pressure measuring module 12. In addition, P on the left side in the drawing of the keyboard 14
POWER switch 16, POWER indicator 18,
An “OK” lamp 20 and an “NG” lamp 22 are provided. Further, on the upper part of the keyboard 14, an LCD is provided.
A display unit 24 is provided, and a pressure sensor 26 is provided on the left side of the LCD display unit 24.

On the other hand, as shown in FIG. 3, the pneumatic tire assembly 58
A printer 28 for printing out the measurement result of the air pressure (see FIG. 1) is provided. Further, a buzzer 30, an extension connector 32, and a power supply 38 for notifying an operator of an air pressure leak are provided.

As shown in FIG. 4, the high-precision pressure measurement module 12 is provided with a CPU board 36.
6, temperature sensor 27, printer 28 and DIO board 4
0 is electrically connected. Also, the DIO board 40
, An LCD display unit 24, a buzzer 30, and a terminal block are electrically connected.

Here, as shown in FIG. 5, a silicon vibration type pressure sensor is used as the pressure sensor 26. This silicon vibration type pressure sensor is provided with a single crystal silicon diaphragm 44 as a pressure receiving element. Further, a micron-sized H-shaped vibrator 46 is provided above the diaphragm 44. This vibrator 4
Reference numeral 6 is formed by semiconductor micromachining technology. The vibrator 46 is also made of single-crystal silicon and formed in a vacuum shell 48. Further, the silicon vibration type pressure sensor is provided with a detection terminal 50 and an excitation terminal 52.

When pressure is applied to the silicon diaphragm 44, stress is generated on the surface of the diaphragm 44, and the vibrator 46
, The tension at both ends changes, and the resonance frequency changes. The vibrator 46 vibrates at a resonance frequency in an excitation circuit. Since the change in the pressure corresponds to the change in the resonance frequency, the pressure can be obtained from the resonance frequency.

Further, as shown in FIG.
Is connected to one end of a pipe 54 made of resin. At a substantially center of the pipe 54, a two-way valve 56 is provided. The two-way valve 56 is connected to a compressor 57 for filling the pneumatic tire assembly 58 with air. By opening the two-way valve 56, the tire 58 can be filled with air by connecting to the pipe 54. By closing the two-way valve 56, the tire 54 is disconnected.

The other end of the pipe 54 is connected to a dedicated valve adapter 62 mounted on a valve 60 of the pneumatic tire assembly 58. The surface of the pneumatic tire assembly 58 is provided with a temperature sensor 27 for measuring the temperature of air supplied to the pneumatic tire assembly 58.

Next, the operation and effect of the air pressure leak detecting device 10 will be described with reference to the flowchart shown in FIG.

First, the special valve adapter 62 is attached to the valve of the pneumatic tire assembly 58, and the two-way valve 56 is mounted.
To supply air from the compressor 57 into the pneumatic tire assembly 58. Pneumatic tire assembly 58
When the air pressure reaches a predetermined pressure value, the two-way valve 57 is closed and the supply of air is stopped.

Then, the POWER switch 16 of the high-precision pressure measuring module 12 is turned "ON". POWER
When the switch 16 is turned “ON”, the POWER indicator 18 lights up, and “Leak” is displayed on the LCD display unit 24.
"Detector Version" (initial screen) is displayed.

Next, in step 100, measurement conditions are input. When the D button on the keyboard 14 is pressed, “Name ****” is displayed on the LCD display unit 24. Here, the name of the condition to be saved is input. When the name is entered, the name entered in "****" is displayed.

When the B button is pressed, the LCD display unit 2 is pressed.
4, "S Press ****" is displayed. Here, the pressure value (kPa) before the start of the measurement is input.
When this pressure value is input, the input pressure value is displayed in “****”.

When the B button is pressed, the LCD display 2
4 displays “Stability *****”.
Here, a stabilization wait time t1 (sec) is input. When the stabilization wait time t1 is input, the timer T0 operates.

When the B button is pressed, the LCD display section 2 is pressed.
4 displays "End Time ****". Here, the measurement end time t20 (sec) is input.

When the B button is pressed, the LCD display unit 2 is pressed.
4, "Interval ****" is displayed. Here, a measurement interval (sampling interval) Δt (sec) is input.

When the B button is pressed, the LCD display section 2 is pressed.
4, "P1 Max ****" is displayed. Here, the upper limit value P1A (kP) of the pressure appropriate range of P1 (first measurement. Here, the numerical value indicates the number of measurement).
a, see FIG. 7).

When the B button is pressed, the LCD display section 2 is pressed.
4, "P1 Min ****" is displayed. Here, the lower limit value P1B (kPa of FIG.
Refer to). The upper limit value and the lower limit value of the appropriate pressure range are determined in consideration of the stabilization waiting time t1 based on the air pressure of the tire 58 before the start of measurement.

Thereafter, this is repeated in the same manner for each of the measurement points P2 to P20, and the upper limit value (P2A to P20) of the appropriate pressure range at each measurement point is obtained.
A) and the lower limit (P2B to P20B) are set. The upper limit value and the lower limit value are set by directly inputting numerical values, and any one of the pressures at the measurement points is set as an initial value, and the upper limit is set based on the allowable value of the initial value and the initial value that have been input in advance. It may be set by obtaining a value and a lower limit. Similarly, the upper limit value (P2A to P20A) and the lower limit value (P2B to P20B) of the appropriate pressure range at the measurement point (P2 to P20) are similarly based on the air pressure of the pneumatic tire assembly 58 before the start of the measurement. It is determined in consideration of the elapsed time.

These input data are stored in the CPU.
It is stored in a memory (not shown) of the board 36. Then, after the input is completed, the user presses the D button. By pressing the D button, the LCD display unit 24 returns to the initial screen.

Next, at step 110, it is determined whether or not the apparatus has waited for the stabilization wait time t1 set as the measurement condition. If it is determined that the apparatus has waited, the process proceeds to step 120.

Next, at step 120, the temperature sensor 27
Thus, the temperature T0 of the surface of the pneumatic tire assembly 58 before the start of the measurement is measured.

Next, at step 130, the measurement point P
Temperature T of pneumatic tire assembly 58 at 1 (at the start of measurement)
Start measurement of N and pressure PN. At this time, the temperature TN is measured first, and then the pressure PN is measured.

In this embodiment, the temperature of the surface of the pneumatic tire assembly 58 or the temperature of the pneumatic tire assembly 5
Although the temperature near 8 may be measured, it is preferable to measure the temperature inside the pneumatic tire assembly 58.

Next, at step 140, the timer T1 is started and waits until the measurement interval Δt set as the measurement condition elapses. When the measurement interval Δt has elapsed, step 15
Go to 0.

Next, in step 150, it is determined whether or not the temperatures TN and the pressures PN at all the measurement points (P1 to P20) have been measured. Temperature TN of all measurement points,
If the pressure PN has not been measured, the process returns to step 130. Then, the temperature TN and pressure P at the next measurement point P2
Measure N. In this way, the temperature TN and the pressure PN at all the measurement points (P1 to P20) are measured.

Next, all the measurement points (from P1 to P2
When it is determined that the temperature TN and the pressure PN of 0) have been measured, the routine proceeds to step 160, where the air pressure PN at each measurement point (P1 to P20) is temperature corrected by the following pressure correction formula (3).

That is, the measured air pressure PN (kPa)
Is the pneumatic tire assembly 5 measured at each measurement point
8 is TN (K, Kelvin), and the temperature of the air inside the pneumatic tire assembly 58 before the measurement is started is T0.
When (K, Kelvin) is used, the pressure value PE after temperature correction is calculated by the following equation: PE = T0 / TN × PN (pressure correction equation) (3)

The pressure correction equation (3) is stored in a memory (not shown) provided on the CPU board 36.

Next, at step 170, the pressure value P after the temperature correction at each measurement point (P1 to P20) is obtained.
E is the pressure upper limit (P1A to P20) at each measurement point (P1 to P20) set as the measurement condition.
A, collectively represented by PNA. ) And lower limit (P1B to P
20B, collectively represented by PNB. ) Is determined (within a predetermined range).

As a result, if the pressure value PE is not within the above-mentioned predetermined range, the routine proceeds to step 180, where the buzzer 30 sounds and the operator is informed that there is an air pressure leak, and the measuring operation is completed. In this case, the “NG” lamp 22 of the high accuracy measurement module 12 is turned on. In addition, the buzzer 30
Stop by pressing any button.

On the other hand, if the pressure value PE is within the predetermined range, that is, "OK", there will be no air pressure leakage.

As a result, each measurement point (from P1 to P2
If all the measurement results in 0) are “OK”, the process proceeds to step 190, and the “OK” lamp 20 of the high accuracy measurement module 12 is turned on. The operator can determine that there is no air pressure leak by confirming that the “OK” lamp 20 is lit.

Note that all measurement points (from P1 to P2
When the determination in step 0) is completed, these measurement results are output from the printer 28. On the recording paper output from the printer 28, a determination result (“OK” or “NG”) and the like are displayed.

Here, FIG. 7 shows each measurement point (P1
To P20, and P1 to P5 in FIG. 7) are graphs showing the relationship between the corrected air pressure PE (kPa) of the pneumatic tire assembly 58 and the elapsed time (S). In this graph, at each of the measurement points (P1 to P5), since the air pressure PE is within the predetermined range set as the measurement condition, it can be seen that no air pressure leaks from the pneumatic tire assembly 58.

As described above, the presence or absence of air pressure leak of the pneumatic tire assembly 58 is measured by measuring the air pressure at each measurement point (P1 to P20) and determining whether or not the measurement result is within a predetermined range. By doing so, the detection can be performed quickly and with high accuracy as compared with the detection method by visual observation.

In particular, although there is a certain relationship between the air pressure and the temperature, the measured air pressure can be more accurately determined by correcting the difference between the temperature before the start of the measurement and the temperature at the time of the measurement.

Further, the present invention detects an air leak not only at the time of initial air leak detection when the pneumatic tire is mounted on the rim and the internal pressure is filled, but also at the time of subsequent use of the pneumatic tire assembly. It can also be used to control the internal pressure of pneumatic tires.

[0066]

According to the apparatus and method for detecting a pneumatic leak of a pneumatic tire assembly of the present invention, the leak of the pneumatic pressure can be detected accurately in a short time.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a pneumatic leak detection device for a pneumatic tire assembly according to an embodiment of the present invention.

FIG. 2 is a front view of a high-precision pressure measurement module included in the pneumatic tire assembly air pressure leak detection device according to one embodiment of the present invention.

FIG. 3 is a rear view of a high-precision pressure measurement module constituting the pneumatic leak detection device for a pneumatic tire assembly according to one embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a high-precision pressure measurement module constituting a pneumatic leak detection device for a pneumatic tire assembly according to one embodiment of the present invention.

FIG. 5 is a configuration diagram of a pressure sensor built in the high-precision pressure measurement module.

FIG. 6 is a flowchart illustrating a method for detecting a pneumatic leak of a pneumatic tire assembly according to the present invention.

FIG. 7 is a graph showing a relationship between air pressure and time of a pneumatic tire assembly after temperature correction.

[Explanation of symbols]

 Reference Signs List 10 air pressure leak detection device 20 "OK" lamp (display unit) 22 "NG" lamp (display unit) 26 pressure sensor (measuring unit) 30 buzzer (alarm unit) 36 CPU board (discriminating unit) 58 pneumatic tire assembly 60 valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuaki Kono 155 Takamurocho, Kofu City, Yamanashi Prefecture (72) Inventor Kei Kei Kawamura 1-19-18 Nakamachi, Musashino City, Tokyo F-term (reference) 2G067 AA48 BB11 DD02

Claims (5)

[Claims] 1. A measuring means connected to a valve of a pneumatic tire assembly for measuring the air pressure of the pneumatic tire assembly, wherein the measured air pressure is within a predetermined range based on the pressure before the start of the measurement. In some cases, it recognizes that there is no air pressure leak,
A determination means for recognizing a pneumatic leak if the air pressure is not within a predetermined range; and a pneumatic tire assembly air pressure leak detecting device. 2. A pneumatic tire assembly comprising: a temperature measuring means for measuring at least one of the inside of the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the temperature of air near the pneumatic tire assembly; The temperature of at least one of the temperature of the air inside the three-dimensional interior, the surface of the pneumatic tire assembly, and the air near the pneumatic tire assembly is TN
(K) measuring at least one temperature T0 (K) of the temperature of the inside of the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the temperature of the air near the pneumatic tire assembly before the start of measurement. When the air pressure of the pneumatic tire assembly is PN, the air pressure PE after temperature correction is determined by PE = T0 / TN × PN (1), and the corrected air pressure PE is determined by the determination means. The pneumatic tire assembly air pressure leak detecting device according to claim 1, wherein: 3. The apparatus according to claim 1, further comprising a display unit for displaying the result of the determination. 4. When the air pressure is not within a predetermined range,
The pneumatic tire assembly air pressure leak detecting device according to any one of claims 1 to 3, further comprising alarm means for visually and / or audibly informing an operator. 5. A setting step of inputting a measurement condition of the air pressure of the pneumatic tire assembly, an air pressure of the pneumatic tire assembly, an inside of the pneumatic tire assembly, a surface of the pneumatic tire assembly and the air. A measuring step of measuring at least one of the temperatures of the air in the vicinity of the pneumatic tire assembly, and the measurement result of the air pressure, the inside of the pneumatic tire assembly at the time of measurement, the surface of the pneumatic tire assembly, and the At least one of the temperatures of the air in the vicinity of the pneumatic tire assembly is defined as TN (K), and the inside of the pneumatic tire assembly, the surface of the pneumatic tire assembly, and the vicinity of the pneumatic tire assembly before the measurement is started. When at least one of the air temperatures is T0 (K) and the measured air pressure of the pneumatic tire assembly is PN. There are, the air pressure PE after temperature correction, PE = T0 /
TN × PN: The temperature correction step determined by (2) is compared with the air pressure after the temperature correction and the measurement condition, and the air pressure after the temperature correction is a predetermined range based on the pressure before the start of the measurement. Determining that there is no air pressure leak when the air pressure is within the predetermined range, and recognizing the air pressure leak if the air pressure is not within the predetermined range.