JPH029975B2 - - 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 was used to measure the tire's internal pressure, and an air filling machine was used to fill the air. . In the conventional air filling machine, as shown in FIG. 1, a ball valve 2, an air filter 3, and a pressure reducing valve 4 are connected to an air pressure source 1, and a solenoid valve 6 is connected downstream of the pressure reducing valve 4 via a pipe joint 5. and an air chuck 7, 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. Incidentally, when there are many set pressures, a large number of pressure switches are provided corresponding to each set pressure. When filling air, the air filling machine connects the air chuck 7 to the valve (not shown) of the tire 11, and in this state switches the solenoid valve 6 to the air pressure source 1.
The tire 11 is filled with air set at a constant pressure through the air filter 3 and the pressure reducing valve 4 for a predetermined period of time to near the specified pressure as shown by the solid line in FIG.
Thereafter, the solenoid valve 6 is switched to stop the air supply, and if the specified pressure is high, the internal pressure of the tire 11 is measured by the high pressure pressure switch 10, and if the filling amount is not output below the specified pressure, the After the operation is performed again to fill the tire 11 with air for a predetermined period of time, the internal pressure of the tire 11 is measured using the pressure switch 10. 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 is turned off and outputs a completion signal, the air chuck 7 is removed from the valve of the tire 11 in preparation for the next work. In the case of a tire with a low specified pressure, the low pressure pressure switch 9 is used to fill the tire with air in the same manner as described above.

As mentioned above, in the conventional filling machine, a large number of pressure switches had to be installed in accordance with the specified pressure of the tire, which resulted in a large size of the device and the problem that the piping was time-consuming. Furthermore, since the pressure switches 9 and 10 cannot measure dynamic pressure, it is necessary to stop the air supply and measure the internal pressure of the tire 11 after supplying air for a predetermined period of time. In the conventional filling method, since an OK signal is always output, the air may be filled above the specified pressure as shown by the chain line in Figure 2 due to an error in the air filling time, resulting in poor filling accuracy. For this reason, it is necessary to set the initial air filling time so that the pressure is below the specified pressure. As shown in the figure, the pressure must be set to a value lower than the specified pressure for low-pressure tires.By doing this, when filling air into high-pressure tires, the amount of air replenishment increases, and usually Since the amount of replenishment is constant, air replenishment must be repeated many times, resulting in very poor workability.

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

C. Structure of the Invention This invention supplies a fixed amount of air to a tire, measures the internal pressure of the tire after the air is supplied with a pressure transducer, and supplies air based on this measured value and the specified pressure of the tire. The required amount is calculated and air corresponding to this calculated value is supplied to the tire to fill it up to a specified 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
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 small specified pressure tires to large specified pressure tires. 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 a valve (not shown) of a 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 is an arithmetic control unit that receives a signal from the pressure transducer 21 and adjusts the tire 24 based on this measured value.
The difference between the measured value and the tire's specified pressure is calculated, the time required to fill the tire with air is calculated from this calculated value, and the solenoid 19 of the solenoid valve 19 is
A and 19b are operated to supply or return air.

The operation of the above configuration will be explained with reference to the flowchart shown in FIG. First, the air chuck 2 is inserted into the valve of the tire 24 to be filled with air.
0, set the specified pressure P0 of the tire 24 in the arithmetic and control unit 23, and store it. After that, when the ball valve 16 is opened, one solenoid 19a of the solenoid valve 19 is turned on and the valve is switched to the air supply position, and a fixed amount of air from the pneumatic source 15 is instantaneously supplied to the tire 24. Turn off solenoid 19a and turn off solenoid valve 1
9 to the air stop position to temporarily stop the air supply. Then, the internal pressure Px of the tire 24 at this time is measured (read) by the pressure transducer 21,
It is transmitted to the calculation control section 23. The calculation control unit 23 determines the size of the tire 24 based on the measured value Px sent from the pressure transducer 21, and also determines the size of the tire 24 based on the measured value Px sent from the pressure transducer 21.
It determines whether Px is high pressure or not, and if the pressure is high as shown by the dashed-dotted line in Figure 5, it detects that the air chuck 20 is installed incorrectly and issues an alarm, and if the pressure is low, it detects that the device is in good condition. do. If the air chuck 20 is installed properly, then the specified pressure is
Calculate the difference ΔP between P0 and the measured value Px, and then divide the calculated value ΔP by the air supply amount per unit time from the pressure reducing valve 18 to obtain the air supply amount corresponding to the calculated value ΔP. Calculate the filling time ΔT. After that, the solenoid 19a is turned ON, the solenoid valve 19 is switched to the air supply position, the air from the pneumatic source 15 is supplied to the tire 24, and after the filling time ΔT has passed, the solenoid 19a is turned OFF and the solenoid valve 19 is stopped. Switch to the position to stop the air supply and complete the filling operation. After this, the air chuck 20 is removed from the valve of the tire 24 in preparation for the next filling operation. The above-mentioned filling operation is shown in the relationship between time and internal pressure of the tire 24.
The result will be as shown by the solid line in the figure.

In the above explanation, air is supplied to the tire 24 from a low pressure state until it reaches a specified pressure, but other tires such as steel radial tires, etc.
When air is supplied into the tire to a pressure sufficiently higher than the specified pressure, and then the pressure is reduced to the specified pressure, as shown by the chain line in Figure 5, the air chuck 2
After detecting whether the mounting condition of the tire is good or bad, set the filling time arbitrarily, and during that time, switch the solenoid valve 19 to the air supply device and supply the air chuck to increase the internal pressure to above the specified pressure. Measure the internal pressure P, After that, the solenoid 19b of the solenoid valve 19 is turned on and the valve 19 is switched to the air return position to exhaust air from the tire. After the exhaust period has elapsed, the solenoid valve 1 is turned on.
9 to the air stop position to stop the exhaust.

E. Effect of the Invention According to this invention, after filling a tire with a certain amount of air, the internal pressure of the tire is measured by a pressure transducer, and based on this measurement value, the difference from the specified pressure and the air supply up to the specified value are determined. It calculates the time and automatically supplies air up to the specified pressure based on the calculation result, so there is no need to repeatedly stop the air supply and measure the internal pressure of the tire, significantly reducing work time. At the same time, the internal pressure of the tire can be accurately measured using a pressure transducer, which improves air supply accuracy, and by applying it to the air filling line in the manufacturing process, work efficiency can be greatly improved. Further, unlike the conventional method, a large number of pressure switches are not required, and a single pressure transducer can handle a plurality of types of tires having different specified pressures, and the equipment becomes smaller.

[Brief explanation of drawings]

Fig. 1 is a drawing showing an air filling device, Fig. 2 is a drawing showing the relationship between the time during air filling and the internal pressure of a tire in a conventional device, and Fig. 3 is a drawing showing an air filling device applied to an embodiment of the method of the present invention. FIG. 4 is a flowchart of the air filling device, and FIG. 5 is a drawing 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 converter, calculate the required amount of air supply based on this measurement value and the specified tire pressure, A method for filling air into a tire, characterized in that air corresponding to this calculated value is supplied to the tire to fill it up to a specified pressure.