JPH029976B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air filling method for automatically filling air at a specified pressure into a tire.

B. Prior Art For example, when filling a tire with air at a specified pressure on a production line, conventionally, a pressure switch set to the specified pressure is used to measure the internal pressure of the tire, and an air filling machine is used to fill the air. was. That is, the conventional air filling machine, as shown in FIG. A valve 6 and an air chuck 7 are connected, and a piping 8 between the solenoid valve 6 and the air chuck 7 is provided with, for example, two types of pressure switches 9 and 10 having different set pressures. In addition, when there are many set pressures, a large number of pressure switches are provided corresponding to each set pressure.

When the air filling machine is filling air, the air chuck 7 is connected to the valve 12 of the tire 11, and in this state, the solenoid valve 6 is switched to set a constant pressure from the air pressure source 1 through the air filter 3 and the pressure reducing valve 4. The tire 11 is filled with air for a predetermined time as shown by the solid line in FIG.
The high pressure pressure switch 10 is used to measure the filling amount, and if the filling amount is not output below the specified pressure, the above operation is performed again to fill the tire 11 with air for a predetermined period of time, and then the pressure switch 10 is used to fill the tire 11 with air.
Measure the internal pressure of The above operation is repeated several times, and when the internal pressure of the tire 11 reaches the specified pressure and the pressure switch 10 switches to output, the air chuck 7 is removed from the valve 12 of the tire 11 in preparation for the next operation. In the case of a tire with a low specified pressure, air is filled by performing the same operation as described above using the low pressure pressure switch 9.

As described above, the conventional filling machine has the problem that a large number of pressure switches must be provided corresponding to the specified pressure of the tire 11, resulting in a large-sized device and time-consuming piping. In addition, since the pressure switches 9 and 10 cannot measure dynamic pressure, they stop the air supply after supplying air for a predetermined period of time.
In addition, the pressure switches 9 and 10 always output if a pressure higher than the set pressure is applied, so in the conventional filling method, due to errors in air filling time, etc. As shown, filling accuracy was poor because it was OK to fill the air above the specified pressure. For this reason, the initial air filling time must be set so that the pressure is below the specified pressure, and when refilling, the filling time must be shortened.
Moreover, if the specified pressure of the tire is high pressure and low pressure, the air filling machine must adjust the initial air filling time to the specified pressure of the low pressure tire, as shown by the dashed line in Figure 2. As a result, when filling air into a high-pressure tire, the amount of air replenishment becomes large, and air replenishment must be repeated many times, resulting in very poor workability.

B. Purpose of the Invention The object of the present invention is to provide an air filling method that has high filling accuracy when filling air into tires, has good workability, and can easily accommodate multiple types of tires with different specified pressures. It is something to do.

C. Structure of the Invention A fixed amount of air is supplied to the tire in advance, the internal pressure of the tire after this air supply is measured with a pressure transducer, and the remaining air filling time is determined based on this measured value and the specified pressure of the tire. Air is supplied based on the calculation result, and then the internal pressure of the tire is measured with a pressure transducer, and the differential pressure between this measured value and the tire's specified pressure is determined, and this differential pressure is determined as the allowable value. If the differential pressure is within the error range, the air supply is stopped, and if the differential pressure is outside the tolerance range, if it is lower than the measured value, calculate the air filling time to compensate for the ear pressure, and calculate the calculation result. When the measured value is higher than the specified pressure, the air bleed time is calculated to remove the differential pressure, and the air is bleed based on the calculation result to specify the internal pressure of the tire. It was designed to create pressure.

D. Example FIG. 3 is a diagram showing an apparatus used for carrying out the method of the present invention, in which 15 is a pneumatic source, 16
1 is a ball valve, 17 is an air filter, and 18 is a pressure reducing valve, which sets the high pressure air sent from the air pressure source 15 to a pressure that can sufficiently supply air from a small specified pressure tire to a large specified pressure tire. Numeral 19 is a 4-port, 3-position solenoid valve, and by operating the solenoids 19a and 19b, air supply, air stop, and air return are switched. 20 is an air chuck attached to the valve 25 of the tire 24. A pressure transducer 21 is installed in the middle of a pipe 22 connecting the solenoid valve 19 and the air chuck 20, and measures the internal pressure of the tire 24 and generates an electric signal. 23
receives the signal from the pressure transducer 21 in the arithmetic control section, determines the size of the tire 24 based on this measured value, calculates the differential pressure from the measured value to the specified pressure of the tire 24, and further calculates the pressure difference from the measured value to the specified pressure of the tire 24. The air filling time required to fill air into the tire 24 or the air release time required to remove air is determined, and either one of the solenoids 19a and 19b of the solenoid valve 19 is operated based on these calculation results. It supplies air or bleeds air.

The operation of the above configuration will be explained with reference to the flowchart shown in FIG. First, the air chuck 20 is attached to the valve 25 of the tire 24 to be filled with air, and the specified pressure (Po) of the tire 19 is set and stored in the arithmetic and control unit 23. After this, the ball valve 16 is opened, and one solenoid 19a of the solenoid valve 19 is turned on to switch the valve 19 to the air supply position, and the air pressure source 15 is turned on.
A fixed amount of air sent from the air filter 17 and the pressure reducing valve 18 is momentarily supplied to the tire 24, and then the solenoid 19a is turned off and the solenoid valve 19 is switched to the air stop position to temporarily stop the air supply. let Then, the internal pressure (Px) of the tire 24 at this time is measured (read) by the pressure converter 21 and transmitted to the calculation control section 23. This measured value (Px) is a value that correlates with the size of the tire 24. The arithmetic control unit 23 determines whether the measured value (Px) sent from the pressure transducer 21 is high pressure or not, and if the pressure is high as shown by the dashed line in FIG. If the pressure is low, it will detect that the device is properly attached. If the air chuck 20 is properly installed, then calculate the differential pressure (ΔP) between the specified pressure (Po) of the tire 24 and the measured value (Px), and then apply the differential pressure (ΔP) to the pressure reducing valve. The air filling time (Δt) required to fill the differential pressure (ΔP) is calculated by dividing by the air supply amount per unit time from 18. After this, solenoid 19a
Turn on and switch the solenoid valve 19 to the air supply position to supply air from the pneumatic source 15 to the tire 24.
After filling time (ΔT) has elapsed, solenoid 1
9a is turned OFF and the solenoid valve 19 is switched to the air stop position to stop the air supply.
Then, the internal pressure of the tire 24 after refilling is measured by the pressure transducer 21 and transmitted to the calculation control section 23. The calculation control unit 23 calculates the differential pressure (ΔP') between the sent measurement value (PX') and the specified pressure (Po) of the tire 24, and this differential pressure (ΔP') is calculated as a preset tolerance. If it is within the tolerance range (0.1%), for example, as shown by the two-dot chain line in Figure 5, the work is completed, the air chuck 20 is removed from the valve 25 of the tire 24, and the next step is performed. Prepare for filling work. If the differential pressure (ΔP') is outside the tolerance range, then it is determined whether the differential pressure (ΔP') is greater or less than 0, that is, the measured value (Px') is less than the specified pressure of the tire 24. Determine whether the pressure is low or high, and if the pressure is low as shown by the solid line in Figure 5, calculate the air filling time (ΔT') required to fill the differential pressure (ΔP'), and Based on the calculation result, turn on solenoid 19a and turn on solenoid valve 1.
9 to the air supply position to supply air to the tire 24, and after the air filling time (ΔT') has elapsed, turn off the solenoid 19a and turn off the solenoid valve 19.
is switched to the air stop position to stop the air supply, after which the internal pressure of the tire 24 is measured, and the differential pressure (ΔP') between this measured value (Px') and the specified pressure (Po) of the tire 24 is determined. If this is within the tolerance, the work is completed. Also, as shown by the chain line in Figure 5, if the measured value (Px') is a high pressure, the air release time (ΔT') required to remove the differential pressure (ΔP') is calculated, and the calculated result is Solenoid 19b based on
Turn ON, switch the solenoid valve 19 to the air bleed position, bleed air from the tire 24, and turn off the solenoid 19b after the air bleed time (ΔT') has elapsed.
Then, switch the solenoid valve 19 to the air stop position to stop air bleeding, then measure the internal pressure of the tire 24, and compare this measured value (Px') with the tire 24.
Find the differential pressure (ΔP') between the specified pressure (Po) and complete the work if it is within the tolerance. In this way, the tire 24 is filled with air by supplying or removing air so that the internal pressure (Px) of the tire 24 approaches the specified pressure (Po) of the tire 24 within the tolerance range.

E. Effects of the Invention According to this invention, the internal pressure of the tire is measured with a pressure transducer, and based on this measurement value, the differential pressure up to the specified pressure of the tire, the air filling time to fill this differential pressure, or the differential pressure are determined. It calculates the air return time to remove the air, and automatically supplies or returns air based on the calculation result to set the tire internal pressure to the specified pressure within the tolerance range, improving air filling accuracy. This is a significant improvement, and there is no need to keep the air filling time constant according to the tire with the lowest specified pressure as in the past, and there is no need to perform air filling blindly, and it is possible to quickly reach the specified pressure based on the calculation results. Air can be supplied or returned with a single button, which greatly improves work time. Further, there is no need to use a large number of pressure switches as in the past, and one pressure transducer can handle a plurality of types of tires with different specified pressures, and the equipment becomes smaller.

[Brief explanation of drawings]

Fig. 1 is a drawing showing a conventional air filling device, Fig. 2 is a drawing showing the relationship between air filling time and tire internal pressure in the conventional device, and Fig. 3 is a drawing used to implement the method of the present invention. Drawing of air filling device, 4th
The figure is a flowchart of the air filling device, and FIG. 5 is a diagram showing the relationship between the time during air filling and the internal pressure of the tire according to the present invention. 15... Air pressure source, 18... Pressure reducing valve, 19... Solenoid valve, 20... Air chuck, 21
...Pressure transducer, 23...Arithmetic control section, 24...
tire.

Claims (1)

[Claims] 1. Supply a certain amount of air to the tire in advance, measure the internal pressure of the tire after this air supply with a pressure transducer, calculate the remaining air filling time based on this measured value and the specified tire pressure, and calculate the remaining air filling time. Air is supplied based on the calculation results, and then the internal pressure of the tire is measured using a pressure transducer, the differential pressure between this measured value and the tire's specified pressure is determined, and this differential pressure is determined within the allowable error range. If it is, stop the air supply,
If the differential pressure is outside the allowable error range, and if the measured value is lower than the specified value, an air filling time is calculated to fill the differential pressure, air is supplied based on the calculation result, and the measured value is lower than the specified value. If the value is higher than the specified pressure, an air release time is calculated to remove the differential pressure, and air is removed based on the calculation result to bring the internal pressure of the tire to the specified pressure. How to fill air into tires.