JPH0739794A - Painting condition setting device and automatic painting system using the same - Google Patents

Abstract

PURPOSE:To improve the response of a control system by a method wherein the electric signal corresponding to a value larger than the difference between the pressure related to alteration and setting and present pressure is supplied to a static converter when the pressure of compressed air supplied to a spray gun is altered and, thereafter, an electric signal for setting the present pressure to the pressure related to alteration and setting is supplied. CONSTITUTION:In the static converter 80 provided to the supply route of compressed air to a spray gun 101 and setting the pressure of compressed air determining a painting condition corresponding to the input of an electric signal, almost primary delay like response is shown with respect to the step like change of an electric signal for altering pressure. A control means 20 supplies the electric signal corresponding to the value larger than the difference between the pressure related to alteration and setting and present pressure to the static converter 80 at the time of the alteration of pressure and subsequently supplies an electric signal setting the present voltage to the pressure related to alteration and setting. As a result, the response of a control system can be improved and an automatic painting system enhanced in painting work efficiency can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating condition setting device and an automatic coating system using the device.

[0002]

2. Description of the Related Art In a coating system, for example, a so-called reciprocator or a coating robot, in an automatic coating system that uses an automatic gun type spray gun to perform coating, atomization and injection of the paint guided to the tip of the paint nozzle are performed. To the object to be coated, the pressure of the pressurized air that is introduced to cause the adjustment of the pressurized air for controlling the spraying pattern and the means for adjusting the spraying pressure of the paint. Process to set according to the desired conditions, that is, the shape of the object to be coated (work) and the coating pattern (pattern) in which the thickness of the coating film in each work is changed (setting process of coating conditions) Is set on the controller of an automatic painting machine such as a reciprocator or painting robot, and the controller presents information about the work or pattern presented in some signal form. It is desired to be able to be based on.

In order to meet such a request, the applicant of the present invention has proposed a coating condition setting device capable of changing the setting of the coating condition according to the information (1990.1. Commodity composition). When applying such a device to an automatic coating system, it should be supplied to the means for receiving and presenting the information presented by the automatic coating machine controller and the spray gun which is an actuator or the intervening paint valve according to the electric signal. It is conceivable to provide an electro-pneumatic converter for controlling the pressure of the pressurized air and a means for calculating and outputting an electric signal to be supplied to the electro-pneumatic converter according to the above discrimination, and in the catalog etc. It raises the point.

[0004]

However, the electropneumatic converter to be used in such a coating condition setting device or coating system is an intermediate connection such as a spray gun or a pipe or a paint valve arranged in a fluid path leading to the spray gun. It should be selected in consideration of the members and the control characteristics thereof. In other words, if priority is given to stability and the electropneumatic converter that is the direct control target is selected, it has a relatively simple feedback circuit for improving the pressure adjustment accuracy, and
Because of insensitivity to various disturbances and suppression of pressure pulsation (chattering), there is no choice but to select equipment with poor sensitivity.
Therefore, the response characteristics have to be sacrificed. If the response characteristics are inferior, the pressure cannot be changed quickly, and the coating conditions cannot be changed instantaneously, which may lead to waste of the coating material or hinder the control of the coating film formation. On the other hand, if a device is selected with priority given to responsiveness (there are some devices such as electro-pneumatic proportional valves that have excellent responsiveness in practice), stability or pressure adjustment accuracy cannot be avoided. A complicated control system configuration is required, which leads to an increase in the size and cost of the coating condition setting device or the coating system and a reduction in maintainability.

In the first place, responsiveness and stability are inherently contradictory concepts, and in constructing a control system, it is important to select a device having a superior function according to the mode of control required. It becomes a problem. In an automatic coating system, it is not preferable that the desired coating is hindered by disturbance or other influences in order to obtain a uniformly coated product, and therefore, a stable means should be used for changing or setting the air pressure. Should be adopted. In that sense, it can be said that it is preferable to use an electropneumatic converter having excellent stability, but on the other hand, the problem of responsiveness must be solved.

[0006]

To this end, the coating condition setting device of the present invention is provided in the compressed air supply path to the spray gun, and the compressed air for determining the coating condition is determined according to the input of an electric signal. An electropneumatic converter for setting a pressure, the electropneumatic converter showing a response of substantially first-order lag with respect to a stepwise change of the electric signal for changing the pressure, and when the pressure is changed, For the static converter,
The control means supplies an electric signal corresponding to a value larger than the difference between the pressure applied to the change setting and the current pressure, and then supplies an electric signal for stabilizing the pressure related to the change setting. Here, the control means may include means for calculating the value according to the difference and means for determining an output time of the electric signal corresponding to the value. The compressed air is supplied for atomizing the paint introduced to the tip of the paint nozzle of the spray gun, adjusting the spray pattern, and operating the spray pressure adjusting means of the paint. Further, the automatic coating system of the present invention is capable of setting such a coating condition setting device, a coating device for coating an object to be coated by using the spray gun, and an operation control command for the coating device. And a coating control device capable of presenting information on the object to be coated according to the operation control of the coating device, and the coating condition setting device receives the information and is determined corresponding to the information. The change setting process of the pressure is performed according to the present coating conditions.

[0007]

According to the present invention, when the pressure of the compressed air to be supplied to the spray gun is changed, a value larger than the difference between the pressure applied to the change setting and the present pressure (that is, low pressure) is applied to the pneumatic converter. To a high pressure, the pressure is higher than the change value. On the other hand, when changing from a high pressure to a low pressure, a pressure lower than the change value) is supplied, and then the pressure according to the change setting is settled. Since the electric signal is supplied, the responsiveness of the control system is improved even when an electropneumatic converter that exhibits a substantially first-order lag-like response to the stepwise change of the electric signal for changing the pressure is used. it can. Also, this makes it possible to realize an automatic painting system with high painting work efficiency.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of an automatic coating system to which the present invention is applied. Here, 100 is an automatic coating machine that can be in the form of a coating robot, a reciprocator, or the like, and coating is performed using the automatic guns 101 of the number and type according to the form. The automatic gun 101 is attached to a robot hand, a jig of a reciprocator, or the like, and has an air control unit 80 described later.
More paint atomizing air (center air that is introduced to the tip of the spray gun paint nozzle to atomize the paint) and spray pattern adjustment air (which is introduced to the corner of the spray gun to determine the spray pattern. Under the control of the automatic coating machine controller 103, the paint supplied from a paint supply source (not shown) through the paint valve 105 is sprayed to apply the paint to the object to be coated. . here,
The automatic coating machine controller 103 can set an operation control command of the automatic coating machine by teaching, programming, etc., and controls the operation of the automatic coating machine according to the setting contents, and the operation control is performed on any work, pattern, etc. It has a terminal capable of outputting information that indicates whether it is implemented correspondingly to the outside. Also, paint valve 1
Reference numeral 05 has a function of controlling the pressure (discharge pressure) of the paint to be supplied to the spray gun 101 in response to the introduction of paint injection pressure control air or the like.

The coating condition setting device in this example is roughly
An interface (I / F) 10 for transmitting and receiving data to and from the automatic coating machine controller 103, a pressure change control unit 20 which is the main control means of the apparatus, and a compressed air control unit 20 for the desired control. Memory unit 30 used for performing
And a console section 60 which is a man-machine interface having an input section 50 and a display section 40 for an operator to access the coating condition setting device or the automatic coating system, and under the control of the pressure change control section 20, Compressed air source 2
00 for appropriately reducing the pressure of the compressed air introduced from 00 to the spray gun. here,
The pressure change control unit 20 controls each unit according to a processing procedure described later with reference to FIGS. 3 to 5, and includes a single CPU or a plurality of CPUs provided to share a plurality of functions, and a D / A. It may have a required input / output unit such as a converter and a driver. Memory part 3
0 is used as a ROM 32 in which fixed data such as a processing procedure executed by the pressure change control unit 20 is stored, a work area in the control process, and an area for expanding data set by an operator or the like. The RAM 34 may be included. In addition, the predetermined contents expanded in the RAM 34 are stored so that they are saved even when the power is turned off.
The AM 34 can be backed up by the battery 36. Further, an EEPROM or the like may be used instead of the RAM. Next, the console section 60 and the air control section 80 of the coating condition setting device will be described with reference to FIG.

In the console section 60, 41C, 41
P and 41T are atomizing air (center air), respectively.
, 51C, 51P, and 51T, which display the set pressure of the pattern air, the set pressure of the pattern air (square air), and the set pressure of the paint ejection pressure (discharge pressure) control air, are respectively displayed on the display units 41C, 41P, and 41T. Correspondingly, it is an operation input unit for the operator to set the pressure. In the figure, an example is provided in which two sets are provided corresponding to the number of spray guns used in the reciprocator type automatic coating machine. Four
Reference numeral 2 is a display unit for displaying a code appropriately determined corresponding to the shape of the work (work) to be coated, and 52 is an operation input unit for switching the code display. 53 is an automatic mode in which the coating condition setting device follows the information of the work presented from the automatic coating machine controller 103, that is, an automatic mode in which the air pressure change control of each part is online, and the automatic coating machine controller 103 is disconnected and each part is offline. The switches 43A and 43M for switching to the manual mode that enables the change control of the air pressure are indicator lamps that light up when the automatic mode is set and when the manual mode is set, respectively. Reference numeral 44 denotes a display unit for displaying the pressure (primary air pressure) of the compressed air supplied from the compressed air source 200, 4
5 is a display unit for displaying an abnormal value of the primary air pressure, 55
Is an operation input unit for the operator to set the abnormal value (for example, a predetermined low pressure). In this example, the display unit 4
1C, 41P, 41T, 42, 44, and 45 have 7-segment displays arranged in a predetermined number of digits. 5
Reference numeral 6 designates a switch used to start the processing for setting the work code and correspondingly setting the pressure of each part, 46
Is a switch that is turned on during the processing. Reference numeral 57 is a switch used to finalize the set value in the process and finish the process, and 47 is a display lamp that is lit in the finalized state. Further, reference numeral 48 is a warning lamp as an informing means for informing of any abnormality such as a decrease in primary pressure.

Next, in the air controller 80, 81C,
81P and 81T are electric signals for setting the pressure of the atomizing air (center air) and the pressure of the pattern air (square air) output by the pressure change control unit 20 according to the setting in the console unit 60, respectively. An electropneumatic converter that controls the primary air pressure in proportion to the electric signal and the electric signal for setting the pressure of the paint ejection pressure control air, for example, an electropneumatic regulator of SMC Corporation can be used. 83C and 83
P is spray gun 1 from 81C and 81P, respectively.
This is an on-off valve provided in the compressed air supply path up to 01. 8
Reference numeral 5 denotes an air cleaner for keeping compressed air supplied from a compressed air source 200 such as a compressor clean.
Is a pressure reducing valve for reducing the primary air pressure to a pressure suitable for the electropneumatic converters 81C, 81P, 81T and the opening / closing valves 83C, 83P, and 89 is a pressure sensor for detecting the primary air pressure, and the detection output thereof is pressure change control. It is displayed on the display unit 44 via the unit 20. FIG. 3 shows an example of a processing procedure in the coating condition registration mode by the coating condition setting device of this example. When this mode is set by using the switch 56, this procedure is started. First, the operator inputs a code of a work or the like and sets the atomizing air pressure, the pattern air pressure and the discharge pressure corresponding to the code. Accept input (step S
M1 and SM2), the display of the display unit is switched according to the input (step SM3). The input set value is RA
The code is temporarily stored in a predetermined area of M34, and in accordance with the operation of the switch 47 (step SM7), the code and the set value are registered in the table in the RAM 43 which is developed in association with each other (step SM9), and the process is ended. FIG. 4 shows an example of a processing procedure in the operation mode by the coating condition setting device.

This procedure is performed by the automatic coating machine controller 103.
According to the information of the work and the like presented from the above, it is started at an appropriate timing in the automatic operation mode in which the change control of the air pressure of each part is performed in the online state, and it is determined in step SD1 whether the automatic mode or the manual mode. If the automatic mode is selected, the automatic coating machine controller 10 is operated in step SD3.
Read information such as work from 3 and then step SD
At 5, it is determined whether or not a change from the current work or the like has occurred. If the change has not occurred here, the process returns to step SD1. On the other hand, if the change has occurred, in step SD7, the work code corresponding to the presented information on the work and the like and the set value corresponding thereto are stored in the RAM 34. Read from the table. Then, in step SD9, an electric signal necessary for the change is sent to the air control unit 80, and in step SD11, a required display is switched,
Return to step SD1. When it is determined in step SD1 that the manual mode is set, step SD11 is performed after the condition setting is accepted in step SD13.
To move to. In this way, the electro-pneumatic converter 81 of the air control unit 80 can be used in both automatic and manual modes.
The air pressure of each part is changed by sending an electric signal to C, 81P, 81T (generally referred to as reference numeral 81 below), but depending on the response characteristics of the electropneumatic converter 81, the change is not made promptly, and the coating conditions are changed. Since it cannot be changed instantaneously, there is a risk that the paint will be wasted and that good management of the coating film will be hindered. That is, as described above, the responsiveness and the stability are inherently contradictory concepts, but in an automatic coating system such as this example, it is a uniform coated product that the desired coating is hindered by disturbance or other effects. Therefore, the means for changing or setting the air pressure should have excellent stability. In that sense, it can be said that the electropneumatic converter 81 used in this example is suitable for an automatic coating system, but on the other hand, it is difficult to respond. Therefore, in this example, the processing procedure as shown in FIG. 5 is adopted to improve the responsiveness of the system, and the responsiveness and stability are appropriately compromised to optimize the automatic coating system. That is, when the changed set value (target value) is sent to the electropneumatic converter 81 used in this example to change the pressure in the spray gun 101, in response to the stepwise change of the target value Pr from the current value Pc. It is known that the pressure response of the control system exhibits almost a first-order lag characteristic as shown in FIG. 6A, though it depends on factors such as the length of the pipe and the pipe resistance. In order to shorten the time until settling to a predetermined pressure value for a system exhibiting such characteristics, in this embodiment, as shown in FIG. 7B, a value (X) different from the initial target value Pr is set. Is set in the electro-pneumatic converter 81, and a predetermined target value is reset after a lapse of a predetermined time (tx) to realize this. Here, as the value X, a value obtained by subtracting the current value Pc from the target value Pr may be multiplied by a constant K and added to the current value Pc. The constant K and the time tx can be appropriately determined according to the difference between the target value Pr and the current value Pc, the characteristics of the control system determined by the configuration of the piping after the electropneumatic converter 81, and the like.

FIG. 5 shows an example of a processing procedure at the time of pressure change setting by the coating condition setting device. Step SD above
This procedure is started when the setting is switched to the air control unit at 9, and first, at step SC1, the difference between the changed set value and the current value is calculated. Next, in step SC3, the K value and tx value are read corresponding to the difference, and step SC5
X value is calculated at. Then, in step SC7, an electric signal corresponding to the value is output to the electropneumatic converter 81, and in step SC9, the timer is activated, and in step SC
When it is determined in 11 that the timer value has exceeded the tx value, an electric signal corresponding to the desired target value Pr is output (step SC13), and in step SC15 the Pc value is replaced with the Pr value for processing. finish. By subjecting the control system showing the transient response characteristic as shown in FIG. 6 (A) to the processing of this example, the output is settled to the desired target value or allowable range as shown in FIG. 6 (B). The time until is shortened.
That is, the workability can be improved by improving the responsiveness of the automatic coating system. In this example, the intermediate value (X) until the final setting of the target value does not have to be one step as shown in FIG. 6, but may be set in multiple steps. Good. Further, the output time (tx) of the intermediate value (X) does not have to be the time at which overshoot as shown in FIG. 6 occurs.
In addition, in the above example, although an example relating to an automatic coating system of a reciprocator type was mainly described, it goes without saying that the present invention can be applied to other automatic coating systems, and the number of spray guns can be changed according to the system to be applied. Of course, the shape, the electro-pneumatic converter, the number of valves in each part, and the like may be appropriately determined. For example, when applied to a painting robot, the console section 60 can be configured as follows.

FIG. 7 shows an example of the construction of the console section. Corresponding parts are designated by the same reference numerals for parts which can be constructed in the same manner as in FIG. In this example, the set pressure of atomizing air (center air) and the pattern air (square air), respectively
41C, 41P and 41 for displaying the set pressure of the paint and the set pressure of the paint ejection pressure (discharge pressure) control air.
T and the operation input sections 51C, 51P and 51T for the operator to set the pressure corresponding to the display section are a single spray gun for ejecting spray pattern adjusting air in two directions (X, Y). It is provided corresponding to the painting robot used. In addition to the input and output sections provided corresponding to the work, the thickness of the coating film (pattern) can also be changed within one work, so that the pattern A display unit 142 for displaying a code, an operation input unit 152 for switching the code display, an automatic mode for changing the air pressure of each part according to information such as a pattern presented from the automatic coating machine controller 103, and an offline state. A switch 153 for switching to a manual mode that enables change control of the air pressure of each part is provided, and display lamps 43A and 43M that are turned on when the automatic mode is set and when the manual mode is set are provided. Further, 156 is a switch used to start a mode for supplying and jetting thinner or the like to wash the paint supply path and the like, and 146 is a switch which is turned on during the processing. Even when the present invention is applied to such an automatic coating system in the form of a coating robot,
In addition to the same effects as described above, teaching work that takes low responsiveness into consideration is not required, so that the work is easy, and even if the work shape or pattern is complicated, it can be handled sufficiently. . Furthermore, since it is possible to use the color change operation time using a color changer or the like to switch the painting conditions within that time, it is possible to further improve the painting work efficiency.

[0015]

As described above, according to the present invention,
When changing the pressure of compressed air to be supplied to the spray gun,
For the static converter, a value that is larger than the difference between the pressure applied to the change setting and the current pressure (that is, a pressure higher than the change value when changing from low pressure to high pressure. On the other hand, when changing from high pressure to low pressure After the electric signal corresponding to the pressure lower than the change value is supplied, the electric signal for stabilizing the pressure according to the change setting is supplied, so that the stepwise change of the electric signal for changing the pressure is performed. The response of the control system can be improved even when using an electropneumatic converter that exhibits an almost first-order lag-like response. This also allows
An automatic painting system with high painting efficiency can be realized.

[0016]

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an automatic coating system to which the present invention is applied.

FIG. 2 is a schematic diagram showing a configuration example of a console and an air control unit of the coating condition setting device in FIG.

FIG. 3 is a flowchart showing an example of a processing procedure in a registration mode by the coating condition setting device.

FIG. 4 is a flowchart showing an example of a processing procedure in an operation mode by the coating condition setting device.

FIG. 5 is a flowchart showing an example of a processing procedure when a pressure change is set by the coating condition setting device.

6 (A) and 6 (B) are diagrams showing response curves at the time of changing the pressure in the case where the processing procedure as in FIG. 5 is not performed and in the case where the processing procedure is performed, respectively.

FIG. 7 is a front view showing another configuration example of the console section of the coating condition setting device in FIG.

[0018]

[Explanation of symbols]

 10 interface 20 pressure change control unit 30 memory unit 32 ROM 34 RAM 40 display unit 50 input unit 60 console unit 80 air control unit 100 automatic coating machine 101 spray gun 103 automatic coating machine controller 105 paint valve 200 compressed air source Pr pressure change value Pc Current pressure value X Intermediate set value when changing pressure tx Intermediate set value Output time

Claims (4)

[Claims] 1. An electropneumatic converter that is provided in a compressed air supply path to a spray gun and sets the pressure of the compressed air that determines a coating condition in accordance with the input of an electric signal,
The electro-pneumatic converter that exhibits a substantially first-order lag-like response to the step-like change of the electric signal for changing the pressure, and the change setting for the pneumatic-electric converter when the pressure is changed. A coating means, comprising: an electric signal corresponding to a value larger than the difference between the pressure and the current pressure, and a control means for supplying an electric signal for stabilizing the pressure according to the change setting. Condition setting device. 2. The control means includes means for calculating the value according to the difference, and means for determining an output time of the electric signal corresponding to the value.
The coating condition setting device described in. 3. The compressed air is supplied for atomizing the paint introduced to the tip of the paint nozzle of the spray gun, adjusting the spray pattern, and operating the spray pressure adjusting means of the paint. The coating condition setting device according to claim 1 or 2. 4. The coating condition setting device according to claim 1, a coating device for coating an object to be coated with the spray gun, and an operation control command for the coating device. A coating control device capable of controlling the operation of the coating device according to the setting content and capable of presenting information on the object to be coated, wherein the coating condition setting device receives the information and outputs the information. An automatic coating system, characterized in that the pressure change setting process is performed in accordance with the coating conditions defined in accordance with.