JPH0255107B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for controlling the amount of paint discharged in automatic painting. The method according to the invention is used, for example, in automatic painting of automobiles.

[Prior art and problems to be solved by the invention]

Generally, in automatic painting technology, an air operated regulator is used as a paint discharge amount adjustment mechanism when painting is performed while changing the paint discharge amount. In an air-operated regulator, a needle linked to a diaphragm is moved due to changes in operating air pressure, and when the pressure of the paint flowing from the needle and the operating air are balanced on the diaphragm, the paint discharge pressure is balanced, thereby increasing the amount of paint discharged. Equilibrate.

Air-operated regulators have low accuracy in areas where the amount of paint discharged is small, and they cannot completely stop the discharge, especially when setting the amount of paint discharged to zero, so they are usually used as air-operated regulators. , and a metering valve that has a paint on/off function. In the metering valve, a spring is used as a reaction force to the operating air pressure to open and close the paint passage.

Conventionally, when controlling the amount of paint discharged by combining an air operated regulator and a metering valve, the following operations are performed. Here,
AOR operating air represents air operated regulator operating air, and MV operating air represents metering valve operating air.

(A) In the case of discharge amount A ₁ → A ₂ , it is as follows.

AOR operation air: P (A ₁ ) → P (A ₂ ) MV operation air: P (OPEN) (B) When the discharge amount A ₁ → 0, the following is true.

AOR operation air: P (A ₁ ) → 0 MV operation air: P (OPEN) → 0 (C) When the discharge amount is 0 → A ₁ , the following is the case.

AOR operation air: 0 → P (A ₁ ) MV operation air: 0 → P (OPEN) Here, P (A ₁ ) and P (A ₂ ) are the air operation regulators corresponding to the discharge amounts A ₁ and A ₂ controller operating pressure,
P(OPEN) is the air pressure required to open the metering valve.

Now, since both air-operated regulators and metering valves are operated by air pressure signals, there is a certain degree of response delay, but generally speaking, metering valves that turn on and off high-pressure operating air It is known that the response is faster than that of an air operated regulator.

Taking this fact as a premise and looking at the three cases listed above, in case (A) it is unavoidable, but in case (C) the actual discharge amount change is due to the slow response of the air operated regulator. The problem of being dominated by response speed is recognized.

In actual painting systems, case (A) is rare;
In most cases, cases (B) and (C) are repeated alternately, and at that time, the value of A ₁ itself changes due to the circumstances.
In most cases, this is the case.

In the case of (C) above, there is a risk of problems with the quality of the coating until the discharge rate stabilizes, so as a practical countermeasure, spraying is carried out, and after the discharge rate has stabilized, , the product is sprayed onto the actual application area. However, from the viewpoint of resource saving and operability, faster response is preferable. The purpose of the present invention is to optimize the timing of changing the operating air pressure of both the air operated regulator and the metering valve when painting while changing the paint discharge amount using the combination of the air operated regulator and the metering valve. The object of the present invention is to increase the response speed, improve responsiveness in controlling the amount of paint discharged, reduce the amount of wasted paint, improve workability in setting coating conditions, and realize appropriate control of the amount of paint discharged.

[Means and actions for solving problems]

In the present invention, when performing automatic painting while adjusting the paint discharge amount by cooperating with the air operated regulator and the metering valve, the paint discharge amount is changed from a first value to a zero value to a second value. When changing from the first value to the zero value, applying an off signal to the metering valve and a signal corresponding to the second value to the air operated regulator, Paint discharging in automatic painting, characterized in that at the time of change from the zero value to the second value, an on signal is applied to the metering valve while the signal of the air operated regulator is maintained. A method of controlling quantity is provided.

In the paint discharge rate control method according to the present invention, an air operated regulator and a metering valve are combined to change the paint discharge rate, and the paint discharge rate is changed from a first value through a zero value to a second value. When changing from the first value to the zero value, the control device sends an off signal to the metering valve, and the control device sends an off signal to the air operated regulator at the time of the change from the first value to the zero value. Corresponding signals are applied respectively, and at the time of change from the zero value to the second value, the signal from the control device to the air operated regulator is maintained, and the ON signal is sent from the control device to the metering valve. is applied.

〔Example〕

FIG. 2 shows a paint discharge rate control device to which a paint discharge rate control method according to an embodiment of the present invention is applied.

FIG. 1 is a waveform diagram showing the change in discharge amount in the device shown in FIG.

In the apparatus shown in FIG. 2, an air operated regulator 1 and a metering valve 2 are provided along a paint P distribution path. The air operated regulator 1 and the metering valve 2 are controlled by air 41, 42 through operating air hoses from the control device 3.

Air operated regulator 1 is case 1
1, a diaphragm 12, and a needle 13. The paint P flows in from the lower inlet and flows out from the right side outlet. Usually the needle 13 is the slit 14
is closed to prevent the inflow of paint P. When a predetermined air pressure is applied by the air 41, the needle 13 descends due to the deformation of the diaphragm 12, the slit 14 is opened, and the paint P flows in. Since the inflowing paint P acts to push up the diaphragm 12, the opening degree of the slit 14 is determined under the condition that the air pressure and the paint pressure are equal. That is, the operating air pressure of the operating air 41 controls the opening degree of the slit 14 and, in turn, the amount of paint discharged.

In the air operated regulator 1, the amount of paint discharged is adjusted in an analog manner.

The metering valve 2 has a case 21, a cylinder 22, and a spring 23. When the operating air pressure of the operating air 42 overcomes the elastic force of the spring 23 and pushes down the cylinder 22, the paint P flows in through the left inlet and flows out through the right outlet.

In the metering valve 2, paint discharge is digitally turned on and off.

The operation of the apparatus of FIG. 2 will be described below with reference to the waveform diagram of FIG. 1 in FIG. 1 shows a model for changing the discharge amount. In this example, the discharge amount is changed from A ₁ to 0 at time t ₁ and from 0 to A ₂ at time t ₂ .

2, 3, and 4 in Figure 1 are conventional operations; 1
According to the setting, the operating air pressure of the air operated regulator is changed from P (A ₁ ) → 0 → P (A ₂ ), while the operating air pressure of the metering valve is changed to the pressure P (OPEN) when the discharge amount is not 0. That is, when the metering valve opens and the discharge amount is 0, the pressure is 0. In this case, response delays d ₁ and d ₂ occur when the actual discharge amount changes, but d ₁ is equal to the on/off change response speed of the metering valve, and d ₂ is 0 → P (A ₂ ) of the air operated regulator. Controlled by change response speed.

In Fig. 1, numbers 5, 6, and 7 are cases in which the method of the present invention is used _.
P(A ₁ ) → P(A ₂ ) at time t ₂
There is a point where it does not change.

As a result, the response delay d ₃ at time t ₂ is dominated by the off->on response speed of the metering valve. Therefore, the difference in the method of changing the operating air pressure of the air operated regulator between conventional cases 2, 3, and 4 and cases 5, 6, and 7 of the present invention is the difference in response delays d ₂ and d ₃ at time t ₂ . It appears as.

As mentioned above, since d ₃ > d ₂ in general, 5, 6, and 7 in the case of the present invention are 2, 3, and 4 in the case of the conventional type.
This results in improved responsiveness compared to . This improved responsiveness is an advantage of the method of the present invention.

The operations 5, 6, and 7 in the case of the present invention are a little more complicated than the operations 2, 3, and 4 in the conventional case, but the operations are made relatively easy by using microcomputer control. It can be carried out. Regarding microcomputer control, reference may be made to Japanese Patent Application No. 141365/1983 by the present applicant.

Furthermore, it is even more effective to combine the method of the present invention with a method for correcting the response delay of the air controller. The reason for this is that while the response delay of an air-operated regulator is affected by the range of change in discharge amount, the response delay of a metering valve is almost entirely determined by physical conditions such as metering valve capacity and operating air hose length. This is because the response delay of the air control equipment can be corrected very easily and with high accuracy because the In addition to the difference in response delay time itself, the ease of correction can be cited as an advantage of the method of the present invention. Furthermore, regarding the method of correcting the response delay of the air control equipment mentioned above, reference can be made to Japanese Patent Application No. 140558/1983 filed by the present applicant.

〔Effect of the invention〕

According to the present invention, the timing of changing the operating air pressure of both the air operated regulator and the metering valve is optimized, and the response speed is increased.
The responsiveness in controlling the amount of paint discharged is improved, the amount of wasted paint is reduced, the workability of setting painting conditions is improved, and appropriate control of the amount of paint discharged is realized.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating changes in the air operated regulator operating air pressure, metering valve operating air pressure, and paint discharging amount in a method for controlling the paint discharging amount in automatic painting as an embodiment of the present invention, and FIG. 1 is a diagram showing a device used to execute a method for controlling the amount of paint discharged in automatic painting as an embodiment of the present invention. FIG. 1... Air operated regulator, 11... Case, 12... Diaphragm, 13... Needle, 14
...Slit, 2...Metering valve, 21...Case, 22...Cylinder, 23...Spring, 3...Control device, 41, 42...Operation air, P...Paint.

Claims (1)

[Scope of Claims] 1. When performing automatic painting while adjusting the paint discharge amount by cooperating an air operated regulator and a metering valve, the paint discharge amount is changed from a first value to a zero value to a second value.
When changing from the first value to the zero value, an off signal is applied to the metering valve and a signal corresponding to the second value is applied to the air operated regulator. Then, from zero value to the second
A method for controlling a paint discharge amount in automatic painting, characterized in that at the time of change to the value of , an on signal is applied to the metering valve while the signal of the air operated regulator is maintained.