JP3024892B2 - Coating condition setting device and automatic coating system using the same - Google Patents

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 same.

[0002]

2. Description of the Related Art In a coating system, for example, a so-called reciprocator or a coating robot, an automatic coating system for performing coating using a spray gun in the form of an automatic gun performs atomization and spraying of a paint guided to a paint nozzle tip. The pressure of the pressurized air for controlling the spray pressure of the paint and the pressure of the pressurized air introduced to the means for adjusting the jetting pressure of the paint for controlling the spray pattern is applied to the object to be coated. Processing to set each according to the desired conditions, that is, the shape of the work to be coated (work) and the different coating (pattern) in which the thickness of the coating film in each work is changed (coating condition setting processing) Is set in a controller of an automatic coating machine such as a reciprocator or a coating robot, and the controller presents information on workpieces and patterns presented in some signal form. It is desired to be able to be based on.

[0003] In order to meet such a demand, the present applicant has proposed a coating condition setting device capable of changing the setting of the coating condition according to the information (1990.1. A collect system issued by CKD). Commodity composition). In applying such an apparatus to an automatic coating system, information presented by the automatic coating machine controller should be accepted and supplied to a spray gun as an actuator or an interposed paint valve in response to an 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 determination. It raises a point.

[0004]

However, an electropneumatic converter to be used in such a coating condition setting device or coating system is provided with an intermediate connection such as a spray gun or piping or a paint valve disposed in a fluid path leading to the spray gun. The selection should be made in consideration of the members and the control characteristics thereof. That is, if the electropneumatic converter to be directly controlled is selected with priority given to stability, it has its own relatively simple feedback circuit for improving pressure adjustment accuracy,
Insensitive to various disturbances and pressure pulsation (chattering) must be suppressed to select equipment with low 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. This may cause waste of the paint or hinder the management of the coating film formation. On the other hand, if equipment is selected with priority on responsiveness (actually excellent equipment such as electro-pneumatic proportional valves also exist), stability or pressure adjustment accuracy cannot be reduced. This requires a complicated control system configuration, which results in an increase in the size and cost of the coating condition setting device or the coating system, and a reduction in the maintainability.

In the first place, the responsiveness and the stability are inherently contradictory concepts, and in configuring a control system, it is important to select a device having an excellent function in accordance with a required control mode. Issues. In an automatic coating system, it is not preferable that the desired coating is hindered by disturbances or other influences in obtaining a uniform coating product.Therefore, a means for changing or setting the air pressure should be one having excellent stability. Should be adopted. In that sense, it may be preferable to use an electropneumatic converter having excellent stability, but the problem of responsiveness must be solved.

[0006]

For this purpose, a coating condition setting device according to the present invention is provided in a supply path of compressed air to a spray gun, and determines the coating condition according to an input of an electric signal. An electro-pneumatic converter for setting pressure, the electro-pneumatic converter showing a substantially first-order lag-like response to a step-like change in the electric signal for changing the pressure, and when changing the pressure, For the static converter,
After supplying an electric signal corresponding to a value greater than the difference between the pressure according to the change setting and the current pressure, a control unit that supplies an electric signal for stabilizing the pressure according to the change setting. Here, the control means may include means for calculating the value in accordance with the difference, and means for determining an output time of the electric signal corresponding to the value. Further, the compressed air is supplied for atomizing the paint guided to the tip of the paint nozzle of the spray gun, adjusting a spray pattern, and operating a paint ejection pressure adjusting means. Further, the automatic coating system of the present invention can set such a coating condition setting device, a coating device that performs coating on an object to be coated using the spray gun, and an operation control command of the coating device. A control device that controls the operation of the coating device according to the present invention, and a coating control device capable of presenting information on the object to be coated.The coating condition setting device receives the information and is determined in accordance with the information. The change setting process of the pressure is performed according to the 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 current pressure (ie, the low pressure) is supplied to the electrostatic converter. To change the pressure to a high pressure from the change value. On the other hand, to change the pressure from the high pressure to the low pressure, a pressure lower than the change value is supplied. Since an electric signal is supplied, the response of the control system is improved even in the case of using an electropneumatic converter that exhibits a substantially first-order lag-like response to a step-like change in the electric signal for changing pressure. it can. In addition, 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 below in detail with reference to the drawings. FIG. 1 shows an embodiment of an automatic coating system to which the present invention is applied. Here, reference numeral 100 denotes an automatic coating machine which can be in the form of a coating robot, reciprocator, or the like, and performs the coating by using the automatic gun 101 of the number and the shape corresponding to the shape. The automatic gun 101 is attached to a jig of a robot hand or a reciprocator, and an air control unit 80 described later.
Air for atomizing paint (center air for spraying paint at the tip of paint nozzle of spray gun) and air for adjusting spray pattern (introducing to corner of spray gun to determine spray pattern Under the control of the automatic coater controller 103, the paint supplied from the paint supply source (not shown) via the paint valve 105 is injected under the control of the automatic coater controller 103, and the paint is applied to the workpiece. . here,
The automatic coating machine controller 103 can set the operation control command of the automatic coating machine by teaching, programming, etc., and controls the operation of the automatic coating machine according to the set contents, and the operation control is performed for any work, pattern, or the like. It has a terminal capable of outputting to the outside information indicating whether the operation is performed in response. 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 spray pressure control air or the like.

[0009] 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 serving as a main control unit of the apparatus, and the compressed air control unit 20 controlling the intended operation. Unit 30 used for performing
A console unit 60 which is a man-machine interface having an input unit 50 and a display unit 40 for an operator to access a coating condition setting device or an automatic coating system, and under the control of a pressure change control unit 20, Compressed air source 2
And an air control unit 80 for appropriately reducing the pressure of the compressed air introduced from 00 and supplying the compressed air to the spray gun. here,
The pressure change control unit 20 controls each unit in accordance with a processing procedure described later with reference to FIGS. 3 to 5, and includes a single CPU or a plurality of CPUs provided to respectively 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
Reference numeral 0 denotes a ROM 32 storing processing data and other fixed data executed by the pressure change control unit 20 and an area for developing data and the like set by an operator and the like in addition to being used as a work area in the process of control. Having the RAM 34. In addition, the predetermined contents developed in the RAM 34 are stored even when the power is turned off.
The AM 34 can be backed up by a battery 36. Further, instead of the RAM, an EEPROM or the like may be used. Next, the console unit 60 and the air control unit 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.
The display units 51C, 51P, and 51T for displaying the set pressure of the pattern air (square air) and the set pressure of the paint ejection pressure (discharge pressure) control air are displayed on the display units 41C, 41P, and 41T, respectively. It is an operation input unit for the operator to set the pressure correspondingly, and the figure shows an example in which two sets are provided corresponding to the number of spray guns used in the reciprocator type automatic coating machine. 4
Reference numeral 2 denotes a display unit for displaying a code appropriately determined according to the shape or the like of a workpiece (work), and reference numeral 52 denotes an operation input unit for switching the code display. Reference numeral 53 denotes an automatic mode in which the coating condition setting device controls the change of air pressure in each part in an online state according to information on a work or the like presented from the automatic coating machine controller 103, and separates each part in the offline state from the automatic coating machine controller 103. Switches 43A and 43M for switching between a manual mode and an air pressure change control are display lamps that are turned on when an automatic mode is set and when a manual mode is set, respectively. Reference numeral 44 denotes a display for displaying the pressure (primary air pressure) of the compressed air supplied from the compressed air source 200.
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 each have a 7-segment display with a predetermined number of digits. 5
Reference numeral 6 denotes a switch used for activating a process for setting a work code and setting a pressure of each part corresponding to the work code.
Is a switch that lights up during the process. Reference numeral 57 denotes a switch used when the set value in the process is determined and the process is completed, and 47 denotes a display lamp which is lit when in the determined state. Reference numeral 48 denotes a warning lamp as notification means for notifying the occurrence of any abnormality such as a decrease in primary pressure.

Next, in the air control unit 80, 81C,
81P and 81T are pressure setting electric signals of atomizing air (center air) and pressure setting of pattern air (square air) output by the pressure change control unit 20 according to the settings 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 manufactured by 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 a compressed air supply path leading to 01. 8
5 is an air cleaner for cleaning compressed air supplied from a compressed air source 200 such as a compressor, 87
Is a pressure reducing valve for reducing the primary air pressure to a pressure suitable for the electropneumatic converters 81C, 81P, 81T and the on-off valves 83C, 83P. 89 is a pressure sensor for detecting the primary air pressure. The information 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 the present embodiment. 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), display switching of the display unit is performed according to the input (step SM3). The input setting value is RA
The code is temporarily stored in a predetermined area of M34, and is registered in a table in the RAM 43 in which the code and the set value are developed in association with the operation of the switch 47 (step SM7) (step SM9), and the process ends. 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.
Is started at an appropriate timing in the automatic operation mode in which the air pressure change control of each section is performed in an online state according to the information such as the work presented from the computer. If the automatic mode is selected here, the automatic coating machine controller 10 is set in step SD3.
Read information such as work from 3 and then go to Step SD
At 5, it is determined whether a change from the current work or the like has occurred. If the change has not occurred, the process returns to step SD1. If the change has occurred, in step SD7, the work code corresponding to the information of the presented work and the corresponding set value are stored in the RAM 34. Read from table. Then, in step SD9, an electric signal required for the change is transmitted to the air control unit 80, and in step SD11, a required display is switched.
It returns to step SD1. If it is determined in step SD1 that the mode is the manual mode, after accepting the condition setting in step SD13, the process proceeds to step SD11.
To move to As described above, in both the automatic and manual modes, the electropneumatic converter 81 of the air control unit 80 is used.
By sending electric signals to C, 81P, and 81T (hereinafter collectively denoted by reference numeral 81), the air pressure of each part is changed. However, depending on the response characteristics of the electropneumatic converter 81, a quick change is not made, 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. However, in an automatic coating system such as this example, it is not uniform coating product that the desired coating is hindered by disturbance or other influence. Therefore, the means for changing or setting the air pressure should be one having excellent stability. In that sense, the electropneumatic converter 81 used in the present example can be said to be suitable for an automatic coating system, but has poor responsiveness. Therefore, in this example, the processing procedure shown in FIG. 5 is adopted to improve the responsiveness of the system, and the responsiveness and the stability are appropriately compromised to optimize the automatic coating system. That is, when a change set value (target value) is sent to the electropneumatic converter 81 used in this example and the pressure is changed in the spray gun 101, the change in the target value Pr from the current value Pc in a step-like manner is obtained. It is known that the pressure response of the control system exhibits a substantially first-order lag characteristic as shown in FIG. 6A, although it depends on factors such as the length of the pipe and the pipe resistance. In order to reduce the time required for the system exhibiting such characteristics to settle to a predetermined pressure value, in the present embodiment, as shown in FIG. 7B, a value (X) different from the initial target value Pr is used. Is set in the electropneumatic converter 81, and after a predetermined time (tx) elapses, the desired target value is reset and this is realized. Here, the value X can be a value obtained by multiplying a value obtained by subtracting the current value Pc from the target value Pr by a constant K, and adding this 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 when a pressure change is set 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 the tx value are read in accordance with the difference, and in step SC5
To calculate the X value. Then, in step SC7, an electric signal corresponding to the value is output to the electropneumatic converter 81, and in step SC9, a timer is started, and in step SC9,
When it is determined in step 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 to perform the processing. finish. By performing the processing of this example on a control system exhibiting a transient response characteristic as shown in FIG. 6A, the output is settled to an intended target value or an allowable range as shown in FIG. 6B. Time is reduced.
That is, the work efficiency can be improved by improving the response of the automatic coating system. In this example, the value (X) set in the middle before the target value is finally set does not have to be one stage as shown in FIG. Good. Also, the output time (tx) of the intermediate value (X) does not have to be the time at which the overshoot occurs as shown in FIG.
In the above example, the embodiment relating to the automatic coating system in the form of a reciprocator has been mainly described. However, it is needless to say that the present invention can be applied to other automatic coating systems, and the number of spray guns may vary depending on the system to be applied. Needless to say, the configuration, the electropneumatic 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 unit 60 can be configured as follows.

FIG. 7 shows an example of the configuration of the console unit. Portions that can be configured in the same manner as in FIG. 2 are denoted by the same reference numerals. In this example, the set pressure of the atomizing air (center air) and the pattern air (square air)
Units 41C, 41P and 41 for displaying the set pressure of the air for controlling the paint ejection pressure and the paint ejection pressure (discharge pressure).
The operation input units 51C, 51P, and 51T for the operator to set the pressure corresponding to T and the display unit use a single spray gun that sprays the spray pattern adjustment air in two directions (X, Y). It is provided corresponding to the painting robot used. Further, in addition to the input and output sections provided corresponding to the work, the thickness and the like (pattern) of the coating film can be changed within one work, so that the pattern of the pattern can be changed. A display unit 142 for displaying a code, an operation input unit 152 for switching the code display, an automatic mode for controlling air pressure change of each unit according to information such as a pattern presented from the automatic coating machine controller 103, and an offline state A switch 153 is provided for switching between manual modes that enable control of changing the air pressure of each section, and display lamps 43A and 43M that are turned on when the automatic mode is set and when the manual mode is set. Reference numeral 156 denotes a switch used to start a mode in which thinner or the like is supplied and ejected to wash the paint supply path and the like, and reference numeral 146 denotes a switch which is turned on during the process. Even when the present invention is applied to such an automatic painting system in the form of a painting robot,
In addition to providing the same effects as described above, teaching is not required in consideration of low responsiveness, so that the work becomes easy, and it is possible to sufficiently cope with a complicated work shape and pattern. . Furthermore, since the coating condition can be switched within the time by utilizing the color change operation time using a color changer or the like, the coating work efficiency can be further improved.

[0015]

As described above, according to the present invention,
When changing the pressure of the compressed air to be supplied to the spray gun,
For the static converter, a value 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 supplying an electric signal corresponding to the pressure (lower than the change value), an electric signal for setting the pressure according to the change setting is supplied, so that a step-like change in the electric signal for changing the pressure is provided. The response of the control system can be improved even when using an electropneumatic converter exhibiting an almost first-order lag-like response. This also gives
An automatic painting system with high painting work efficiency can be realized.

[0016]

[Brief description of the drawings]

FIG. 1 is a block diagram showing one 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 illustrating an example of a processing procedure in a registration mode by the coating condition setting device.

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

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

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

7 is a front view showing another example of the configuration of the console unit of the coating condition setting device in FIG. 1. FIG.

[0018]

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Interface 20 Pressure change control part 30 Memory part 32 ROM 34 RAM 40 Display part 50 Input part 60 Console part 80 Air control part 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 at pressure change tx Intermediate set value output time

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-31849 (JP, A) JP-A-63-267467 (JP, A) JP-A-4-114756 (JP, A) 44068 (JP, U) JP-A 64-44067 (JP, U) JP-A-4-41755 (JP, U) JP-A-3-90650 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B05B 12/00

Claims (4)

(57) [Claims] 1. An electro-pneumatic converter provided in a supply path of compressed air to a spray gun and for setting a pressure of the compressed air for determining a coating condition according to an input of an electric signal,
The electropneumatic converter showing a substantially first-order lag-like response to the step change of the electric signal for changing the pressure, and, when the pressure is changed, the pneumatic converter is set to the change setting. Coating means for supplying an electric signal corresponding to a value larger than the difference between the pressure and the current pressure, and then supplying an electric signal for stabilizing the pressure according to the change setting. Condition setting device. 2. The control device according to claim 1, wherein the control unit includes a unit that calculates the value in accordance with the difference, and a unit that determines an output time of the electric signal corresponding to the value.
The coating condition setting device described in 1. 3. The method according to claim 1, wherein the compressed air is supplied for atomizing paint, adjusting a spray pattern, and operating a paint ejection pressure adjusting means guided to a paint nozzle tip of the spray gun. The coating condition setting device according to claim 1 or 2, wherein 4. A coating condition setting device according to claim 1, wherein the coating device performs coating on an object to be coated using the spray gun, and an operation control command of the coating device is set. A coating control device capable of controlling the operation of the coating device according to the setting contents and presenting information on the object to be coated, the coating condition setting device receiving the information, An automatic coating system, wherein the pressure change setting process is performed in accordance with a coating condition determined in accordance with (1).