JPH06266447A - Control method for paint concentration - Google Patents

Abstract

PURPOSE:To execute automatic control of high control performance according to output of a concentration sensor by storing a relation of a target dilution water flow rate, a paint concentration value and a dilution water flow rate value in a knowledge base as production rules. CONSTITUTION:In the knowledge base of a controller 15, production rules for setting a paint concentration value and a dilution water flow rate value as condition values, and also, prescribing an optimal target dilution water flow rate for adjusting paint concentration to set paint concentration as an operation value in the paint concentration value and the dilution water flow rate value as an operation value, are stored in advance. The present paint concentration value is detected by a concentration sensor 5, the present dilution water flow rate is detected by a flowmeter 13, and both of those which are detected are inputted to the controller 15. In the controller 15, by a fuzzy inference engine, the production rule is executed successively and an optimal target dilution water flow rate in the present paint concentration value and the present dilution water flow rate value is calculated. Subsequently, an instruction for opening is given to a flow rate control valve 12 so as to have the calculated target dilution water flow rate, and the dilution water flow rate is controlled to an optimal value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint concentration control method in a paint applying / collecting facility provided in a manufacturing process of building materials for houses such as roofing materials and wall materials.

[0002]

2. Description of the Related Art Conventionally, in the manufacturing process of roof materials and wall materials, which are building materials for houses, coating materials are applied to the surface of building materials while the building materials are being carried by a carrying device such as a conveyor.
Then, the excess paint is returned to the paint recovery tank through a paint receiving member provided below the transport device and is recycled.
At this time, since the building material is heated to about 60 ° C., the water in the paint that returns to the paint recovery tank evaporates, and the paint concentration gradually increases when left standing. For this reason, an operator periodically adjusts the paint concentration by sampling the paint, measuring the paint concentration, and injecting dilution water into the paint recovery tank based on the measurement result.

Further, a concentration sensor capable of measuring the concentration in real time is installed in the circulation route of the paint, and the flow rate of dilution water is controlled by PID control according to the output of the concentration sensor to adjust the paint concentration.

[0004]

However, in the above-mentioned conventional configuration, it takes a lot of manpower to control the concentration by the worker, and the operation may be different for each worker.
There was a problem that the range of paint concentration values managed increased.

Further, P performed based on the output of the density sensor
The ID control has a problem that control performance against disturbance is poor, excessive dilution is caused, the paint concentration fluctuates up and down within a constant width including an appropriate value, and it takes time to settle to the appropriate value.

The present invention solves the above problems and provides a paint concentration control method capable of performing automatic control on the basis of the output of a concentration sensor and performing control with good control performance. To aim.

[0007]

In order to solve the above-mentioned problems, the paint concentration control method of the present invention collects excess paint applied to an object to be coated in a paint recovery tank and reuses it. In a paint application / recovery facility that supplies dilution water to a paint recovery tank to adjust the paint concentration to a set concentration, the paint concentration value and the dilution water flow rate value are used as condition values in the knowledge base of the control device in advance. A concentration sensor installed in the middle of the paint circulation path that stores the production rule that regulates the optimum target dilution water flow rate for adjusting the paint concentration to the set paint concentration at the paint concentration value and the relevant dilution water flow rate value. The current paint concentration value is detected by the current paint flow rate value supplied to the paint recovery tank by the flow meter provided in the middle of the dilution water supply path The concentration value and the current dilution water flow rate value are input to the control device, and the knowledge base production rule is sequentially executed in the control device to calculate the optimum target dilution water flow rate for the current paint concentration value and the current dilution water flow rate value. ,
The configuration is such that the opening degree of the flow rate control valve provided in the middle of the dilution water supply path is controlled so that the calculated target dilution water flow rate is obtained.

[0008]

With the above configuration, unlike the conventional PID control, the target dilution water flow rate is not uniquely set by the paint concentration value at that time, and the target dilution water flow rate, paint concentration value and dilution water are set. By storing the relationship between the flow rate values as a production rule in the knowledge base of the control device, it is possible to set a different target dilution water flow rate when the dilution water flow rate is different even if the paint concentration value is the same.

For example, when the current paint concentration is far from the set paint concentration and the current dilution water flow rate is large, the target dilution water flow rate is set smaller than when the current dilution water flow rate is small.

Therefore, the target dilution water flow rate changes momentarily depending on the paint concentration value at each moment, and also changes momentarily depending on the dilution water flow rate value at each moment, so that the dilution water supplied to the paint recovery tank becomes excessive or too small. It is possible to control the paint concentration to the set paint concentration with high accuracy.

[0011]

[Embodiment] Hereinafter, coating material application in one embodiment of the present invention
The recovery facility will be described with reference to the drawings. 1 and 2, a conveyor 1 conveys a roof material or a wall material of a building material as a coating object 2 and has a blind-shaped conveyor belt. A paint application unit 4 is arranged above the transport conveyor 1 so as to be connected to the tip of the paint supply pipe 3, and a concentration sensor 5, a pulsating flow prevention unit 6, and a pump 7 are provided in the middle of the paint supply pipe 3. I am intervening. Furthermore, a paint recovery tank 8 is provided in communication with the base end of the paint supply pipe 3.

The paint recovery tank 8 has a transfer conveyor 1
The surplus paint receiving portion 9 arranged below is communicated with the dilution water supply pipe 10 and the paint supply pipe 11. A dilution water flow control valve 12 and a flow meter 13 are provided in the middle of the dilution water supply pipe 10, and a paint flow control valve 14 is provided in the middle of the paint supply pipe 11.

The concentration sensor 5, the dilution water flow rate control valve 12, the flow meter 13, and the paint flow rate control valve 14 are connected to a control device 15 via signal lines, and as shown in FIG. 2, a fuzzy control system is used. Make up 20.

The fuzzy control system 20 includes a detection unit 21 including a concentration sensor 5 and a flow meter 13 and the like, an operation unit 22 including a dilution water flow rate adjusting valve 12 and a paint flow rate adjusting valve 14, and a program in the controller 15. It is composed of a knowledge base 23 and a fuzzy inference engine 24 as a functional circuit formed by.

In the knowledge base 23, the paint concentration value and the dilution water flow rate value are set as the condition values in advance, and the optimum target for adjusting the paint concentration to the set paint concentration at the paint concentration value and the dilution water flow rate value is set. Stores the production rule that regulates the dilution water flow rate as the operating value. The fuzzy inference engine 24 executes production rules in order based on the detection result input from the detection unit 21,
The operation value is instructed to the operation unit 22.

The operation of the above structure will be described below.
The coating object 2 is transported to a position corresponding to the coating material application section 4 by the conveyor 1, and the coating material supplied from the coating material supply pipe 3 by the pump 7 is applied to the coating object 2 by the coating material application section 4. Then, the excess paint dripping from the transport conveyor 1 is collected in the paint collecting tank 8 through the paint receiving portion 9 and is recycled. The excess paint returning to the paint recovery tank 8 has a high concentration due to evaporation of water to some extent because the coating object 2 is heated to room temperature or higher, and the paint concentration in the paint recovery tank 8 is high. Always changes to become thicker. Therefore, the dilution water is supplied through the dilution water supply pipe 10 to control the paint concentration to the set paint concentration. Further, the paint is supplied from the paint supply pipe 11 as needed.
This control will be described below.

The current paint concentration value of the paint passing through the paint supply pipe 3 is detected by the concentration sensor 5 and the current flow rate of the dilution water is detected by the flow meter 13. The detected current paint concentration value and the current dilution water flow rate value are input to the control device 15, and the fuzzy inference engine 24 sequentially executes the production rules of the knowledge base 23 in the control device 15 to sequentially execute the current paint concentration value and the current dilution water. Calculate the optimal target dilution water flow rate for the flow rate value. Then, the opening degree is instructed to the flow rate control valve 12 so that the calculated target dilution water flow rate is obtained, and the dilution water amount is controlled to an optimum value.

Therefore, since the target dilution water flow rate changes momentarily depending on the paint concentration value at each moment, and also changes depending on the dilution water flow rate value at each moment, the dilution water supplied to the paint recovery tank 8 becomes excessive or too small. Therefore, the paint concentration can be controlled to the set paint concentration with high accuracy.

[0019]

As described above, according to the present invention, the relationship between the target dilution water flow rate, the paint concentration value, and the dilution water flow rate value is stored in the knowledge base of the control device as a production rule, so that the paint concentration value Even if the same, the target dilution water flow rate can be set to a different value if the dilution water flow rate is different, and the target dilution water flow rate is unique depending on the paint concentration value at that time, as in conventional PID control. Since the target dilution water flow rate can be set to the most appropriate value for the paint concentration value and the dilution water flow rate value at each time, the dilution water supplied to the paint recovery tank becomes excessive and excessive. It is possible to control the paint concentration to the set paint concentration with high accuracy.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of a coating material application / recovery facility according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a fuzzy control system in the embodiment.

[Explanation of symbols]

 2 Coating object 3 Paint supply pipe 5 Concentration sensor 8 Paint recovery tank 10 Diluting water supply pipe 12 Diluting water flow control valve 13 Flowmeter 15 Control device

[Procedure amendment]

[Submission date] April 21, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art Conventionally, in the manufacturing process of roof materials and wall materials, which are building materials for houses, coating materials are applied to the surface of building materials while the building materials are being carried by a carrying device such as a conveyor.
Then, the excess paint is returned to the paint recovery tank through a paint receiving member provided below the transport device and is recycled.
At this time, since the building material is heated to room temperature or higher, the water content in the paint that returns to the paint recovery tank evaporates, and the paint concentration gradually increases when left standing. For this reason, an operator periodically adjusts the paint concentration by sampling the paint, measuring the paint concentration, and injecting dilution water into the paint recovery tank based on the measurement result.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B05C 11/10 6804-4D

Claims (1)

[Claims] 1. A paint application for adjusting the paint concentration to a set concentration by collecting excess water applied to an object to be coated in a paint collection tank for recycling and supplying dilution water to the paint collection tank. Optimum for setting the paint concentration value and the dilution water flow rate value as the condition value in advance in the knowledge base of the controller in the recovery facility, and adjusting the paint concentration to the set paint concentration at the paint concentration value and the dilution water flow rate value. Stores a production rule that regulates a target target dilution water flow rate as an operation value, detects the current paint concentration value with a concentration sensor installed in the paint circulation path, and uses a flow meter installed in the dilution water supply path. The current dilution water flow rate value to be supplied to the paint recovery tank is detected, and the detected current paint concentration value and current dilution water flow rate value are input to the control device, and the knowledge base is entered in the control device. Sequentially executing the production rules of the system to calculate the optimum target dilution water flow rate for the current paint concentration value and the current dilution water flow rate value, and set it in the middle of the dilution water supply route so that it becomes the calculated target dilution water flow rate. A method for controlling a paint concentration, which comprises controlling the opening of a flow control valve.