JP2003010742A - Discharge quantity control apparatus and discharge quantity monitoring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge quantity control apparatus and a discharge quantity monitoring method, by which the number of revolution of a coating material gear pump is monitored to rapidly detect the occurrence of abnormality with a simple configuration. SOLUTION: A coating material supply apparatus 20 for supplying the prescribed quantity of a coating material to the tip of a gun of a coating machine 23 with the coating material gear pump 22 to apply includes a servomotor 24 for rotating the coating material gear pump 22 and a control part 30 for controlling the rotation of servomotor, the servomotor 24 is provided with an encoder and the discharge quantity control apparatus is constituted so that the control part 20 detects the number of revolution of the coating material gear pump 22 based on the detected signal from the encoder and the detected number of revolution is compared to the set number of revolutions to monitor the discharge quantity of the coating material gear pump.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge amount control device and a discharge amount monitoring method for controlling the discharge amount of paint in a paint supply device for automatic painting on the body of an automobile.

[0002]

2. Description of the Related Art Conventionally, such a paint supply device is constructed, for example, as shown in FIG. In FIG. 5, the paint supply device 1 is composed of a paint tank 2 that contains paint, and a paint discharge amount control device 5 that is connected to the paint tank 2 via a pump 3 and a regulator 4. . The regulator 4 controls the pressure of the paint supplied by the pump 3 to control the amount of paint supplied to the paint discharge amount control device 5.

The paint discharge amount control device 5 comprises a paint gear pump 6 and a painting machine 7 having a painting gun tip 7a. The paint gear pump 6 is rotationally driven by the servo motor 6a, and controls the amount of paint discharged to the coating machine 7 based on the number of rotations thereof to supply the paint to the gun tip 7a of the coating machine 7. It is like this. Here, the servo motor 6a is rotated at a predetermined number of revolutions by being controlled by a control unit (not shown), and the paint gear pump 6 is rotationally driven.

According to the paint supply device 1 having such a configuration, the supply amount of the paint 2a contained in the paint tank 2 is controlled by the regulator 4 and is supplied to the paint discharge amount control device 5 by the pump 3. . Then, in the paint discharge amount control device 5, the servomotor 6a is driven and controlled to a predetermined rotation speed, whereby the paint gear pump 6 is rotationally driven at a predetermined rotation speed. As a result, the paint gear pump 6
The paint is supplied from the paint tank 2 to the coating machine 17 at a predetermined discharge amount corresponding to a predetermined rotation speed, and the gun tip 7 of the coating machine 7 is supplied.
The paint is discharged from a.

[0005]

By the way, in such a paint supply device 1, the paint gear pump 6 is rotationally driven at a predetermined number of revolutions by using the servomotor 6a to obtain a predetermined discharge amount. However, since the actual discharge amount of the paint from the gun tip 7a of the coating machine 7 is not guaranteed, even if the discharge amount varies, it cannot be detected. Therefore, the coating quality cannot be easily controlled, and the failure of the paint gear pump 6 cannot be predicted.

On the other hand, there is also a paint discharge amount control device 5 in which an encoder is provided in the paint gear pump 6 to detect the rotation of the paint gear pump 6 and hold the rotation speed at a set rotation speed. However, in this case, the paint gear pump 6
When it becomes impossible to rotate due to some reason such as a failure or the number of rotations decreases, control is performed to maintain the number of rotations by increasing the number of rotations of the servo motor 6a. Therefore, as a result, the rotation of the servo motor 6a and the paint gear pump 6 is abnormally stopped due to the heating of the servo motor 6a or the deviation abnormality of the encoder, and the servo motor 6a may be damaged in some cases.

In view of the above points, the present invention provides a discharge amount control device and a discharge amount monitoring method with a simple structure for monitoring the number of revolutions of a paint gear pump to quickly detect the occurrence of an abnormality. Is intended.

[0008]

According to the present invention, the above object is to supply a paint supplied from a paint tank to a gun tip of a coating machine by a paint gear pump at a predetermined discharge amount for coating. With respect to the apparatus, including a servomotor for rotationally driving the paint gear pump, and a control unit for rotationally controlling the servomotor, further, the servomotor includes an encoder, the control unit,
A discharge amount control device, which detects the rotation speed of the paint gear pump based on a detection signal from the encoder, compares the detected rotation speed with a set rotation speed, and monitors the discharge quantity of the paint gear pump. Achieved by

In the discharge rate control device according to the present invention, preferably, the control section detects the number of revolutions of the paint gear pump on the basis of a detection signal from the encoder during coating, and monitors the discharge rate of the paint by the paint gear pump. To do.

In the discharge rate control device according to the present invention, preferably, the control section detects the number of revolutions of the paint gear pump based on a detection signal from the encoder at the time of cleaning to determine the discharge rate of the cleaning agent by the paint gear pump. Monitor.

In the discharge amount control device according to the present invention, preferably, the control section monitors the discharge amount by the paint gear pump at every predetermined sampling time.

In the discharge amount control device according to the present invention, preferably, when the control unit monitors the discharge amount by the paint gear pump, an error of the detected rotation speed with respect to the set rotation speed exceeds a predetermined abnormality detection level. , Detect the abnormality of the discharge amount by the paint gear pump.

In the discharge amount control device according to the present invention, preferably, the control unit outputs an abnormality detection signal when the number of detections of discharge amount abnormality by the paint gear pump exceeds a predetermined number.

In the discharge rate control device according to the present invention, preferably, the control unit starts monitoring the discharge rate by the paint gear pump after a predetermined time has passed since the paint supply device was started.

Further, according to the present invention, the above object relates to a paint supply device for supplying paint supplied by a pump from a paint tank to a gun tip of a coating machine at a predetermined discharge amount by a paint gear pump for coating. , The control unit controls the rotation of the servomotor to drive the paint gear pump to rotate by the servomotor, and the control unit controls the rotation speed of the paint gear pump based on the detection signal from the encoder provided in the servomotor. The discharge amount monitoring method characterized in that the discharge amount by the paint gear pump is monitored by comparing the detected rotation speed with the set rotation speed.
To be achieved.

According to the above construction, the encoder provided in the servomotor detects the rotation speeds of the servomotor and the paint gear pump to monitor the discharge amount of the paint gear pump. Thus, when the rotation speed becomes impossible or the rotation speed decreases, the control unit can detect the change in the rotation speed of the paint gear pump, and can promptly detect an abnormality such as a failure of the paint gear pump. Therefore, when such an abnormality occurs, the encoder is controlled to increase the rotation speed of the servo motor, and the servo motor and the paint gear pump are not abnormally stopped. Early detection and prediction can be performed, and the actual discharge amount can be monitored, which facilitates analysis of coating defects.

When the control section detects the number of revolutions of the paint gear pump on the basis of the detection signal from the encoder at the time of coating and monitors the discharge amount of the paint by the paint gear pump, The discharge rate can be monitored.

When the control section detects the number of revolutions of the paint gear pump based on the detection signal from the encoder at the time of cleaning and monitors the discharge amount of the cleaning agent by the paint gear pump, the cleaning at the time of cleaning The discharge amount of the agent can be monitored.

When the control unit monitors the discharge amount by the paint gear pump at every predetermined sampling time,
By appropriately selecting the sampling time, the discharge amount by the paint gear pump is monitored every predetermined time, thereby reducing the load on the control unit and detecting the occurrence of an abnormality such as a failure of the paint gear pump relatively quickly. be able to.

When the control unit detects an abnormality in the discharge amount by the paint gear pump when the error of the detected rotation speed with respect to the set rotation speed exceeds a predetermined abnormality detection level when monitoring the discharge amount by the paint gear pump. By appropriately setting the abnormality detection level, it is possible to ignore a slight variation in the detected rotation speed and prevent erroneous detection of an abnormality occurrence.

When the control section outputs an abnormality detection signal when the number of times of detecting the discharge amount abnormality by the paint gear pump exceeds a predetermined number, when the number of times of detecting abnormality is small, the operation of the paint discharging device is continued as it is. As a result, it is possible to prevent the stop due to the abnormality detection and prevent the decrease of the movable ratio.

When the control unit starts monitoring the discharge amount by the paint gear pump after a lapse of a predetermined time from the start of the paint supply device, when the paint supply device is started, the discharge amount is unstable. It is possible to prevent erroneous detection of an abnormality occurrence without monitoring the quantity.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 1 shows the configuration of a paint supply device incorporating an embodiment of a paint discharge amount control device according to the present invention. In FIG. 1, the paint supply device 10 includes a paint tank 11 that contains paint, and a paint discharge amount control device 20 that is connected to the paint tank 11 via a pump 12 and a regulator 13. . The regulator 13 controls the pressure of the paint supplied by the pump 12 to control the amount of paint supplied to the paint discharge amount control device 20. Note that, for example, a coating color switching valve (not shown) that switches and discharges a plurality of colors of coating material may be appropriately inserted downstream of the regulator 13.

The paint discharge amount control device 20 includes a paint gear pump 22 and a painting machine 23 having a painting gun tip 23a.
And a control unit 30. The paint gear pump 22 has a built-in washable gear, and this gear is rotationally driven by a servomotor 24, and the amount of paint discharged from the paint tank 11 to the painting machine 23 is controlled based on the number of revolutions of the paint, thereby performing painting. A controlled fixed amount of paint is supplied to the gun tip 23a of the machine 23. Here, the servo motor 24 is driven and controlled by the control unit 30 to rotate at a predetermined number of revolutions, and the paint gear pump 22 is rotationally driven.

As shown in FIG. 2, the control unit 30 is composed of an input device 31, a sequencer 32, and a control panel 33. The input device 31 uses, for example, a personal computer or the like, and various parameters for controlling the discharge amount, such as a set rotation speed, an abnormality detection level,
The sampling time, the number of times of detection, the non-detection time, etc. are set.

Here, the set rotational speed determines the discharge amount of the paint from the gun tip 23a of the coating machine 23 of the paint discharge amount control device 20. Also, the abnormality detection level is
It is indicated by the ratio (%) of the actual rotation speed of the servo motor 24 to the set rotation speed, and is set to 85 to 90%, for example. The abnormality detection level can be set in multiple stages.

The above sampling time is a time interval for monitoring the actual rotation speed of the servo motor 24. The number of detections sets the number of detections of the abnormality detection level for abnormality detection, and is set to, for example, 2 times. The non-detection time is the time during which the rotation speed monitoring operation is not performed at the start of the operation.

The sequencer 32 outputs a control signal to the control panel 33 based on each parameter set by the input device 31 so that each operation of the discharge amount control is sequentially performed.

The control board 33 controls the drive of the servo motor 24 based on the control signal from the sequencer 32. At that time, the control board 33 controls the drive of the servo motor 24 based on the detection signal of the encoder 24a provided in the servo motor 24.

The paint supply device 10 according to the embodiment of the present invention is configured as described above. The supply amount of the paint 11a contained in the paint tank 11 is controlled by the regulator 13 and the paint discharge amount is controlled by the pump 12. It is supplied to the device 20. In the paint discharge amount control device 20, the paint gear pump 22 is rotationally driven by the control unit 30 drivingly controlling the servo motor 24. As a result, the paint gear pump 22 supplies the paint from the paint tank 11 to the coating machine 23 at a predetermined discharge amount, and the coating machine 2
The paint is discharged from the gun tip 23a of No. 3.

Here, the control unit 30 has various parameters set in advance by the input device 31, and drives and controls the servo motor 24 as follows based on the discharge amount control method according to the present invention.

First, at the time of coating, as shown in FIG. 3, the control panel 33 receives a coating ON signal from the sequencer 32 at the same time when coating is started, and controls the servo motor 24 to drive at a set rotation speed to set the coating gear pump to a predetermined value. It is rotationally driven so as to obtain the discharge amount. Thereby, the paint is discharged.

Thereafter, the control panel 33 detects the abnormality in which the execution rotation speed is set in advance based on the detection signal from the encoder 24a of the servo motor 24 corresponding to the actual rotation speed of the servo motor 24 at every predetermined sampling time. If it is out of the level (ratio to the set speed), the error occurrence is counted.

When the count number of occurrence of this abnormality exceeds the preset detection number, the control panel 33
Output an abnormality detection signal. By outputting this abnormality detection signal to the outside, for example, an alarm is issued or the paint supply device 10 is stopped.

Further, the servo motor 24 rises in FIG. 3 and the execution rotation speed gradually rises to approach the set rotation speed. Therefore, the predetermined non-detection time until the execution rotation speed approaches the set rotation speed. During t1, the control panel 33 does not monitor the rotation of the servo motor 24 described above. As a result, the rotation of the servo motor 24 and the paint gear pump 22 by the control unit 30, that is, the control panel 33 is monitored only during the time t0 of the total coating time T excluding the non-detection time t1. After that, when the coating off signal is input from the sequencer 32 when the coating is completed, the control panel 33 stops the servo motor 24. Then, when the paint-on signal is input again from the sequencer 32, the control panel 33 repeats the above-mentioned operation again.

Next, at the time of cleaning, as shown in FIG. 4, the control panel 33 receives a cleaning ON signal from the sequencer 32 at the start of coating, drives and controls the servo motor 24 at a set number of revolutions, and sets the paint gear pump 22 to a predetermined value. It is rotationally driven so as to obtain the discharge amount. In this case, instead of the paint tank 11,
A cleaning tank (not shown) filled with the cleaning agent is connected to the paint discharge amount control device 20 to discharge the cleaning agent.

Thereafter, the control panel 33 sets the execution rotation speed in advance based on the detection signal corresponding to the actual rotation speed of the servo motor 24 from the encoder 24a of the servo motor 24 at every predetermined sampling time. If the value is out of the abnormality detection level (ratio to the set speed), the occurrence of abnormality is counted.

When the count number of occurrence of this abnormality exceeds the preset detection number, the control panel 33
Output an abnormality detection signal. This abnormality detection signal is
By being output to the outside, for example, an alarm is issued,
Alternatively, the paint supply device 10 is stopped.

In this case as well, the servo motor 24 is similarly operated.
4 rises in FIG. 4 and the execution rotation speed gradually increases to approach the set rotation speed. Therefore, during the predetermined non-detection time t2 until the execution rotation speed reaches the vicinity of the set rotation speed, the control panel 33
Does not monitor the rotation of the servo motor 24 described above. At the time of cleaning, the set rotation speed (discharge amount), rotation time (that is, cleaning time t3), non-detection time t2, etc. are set to values different from those at the time of coating suitable for cleaning.

In the above-described embodiment, only one abnormality detection level is set, but the present invention is not limited to this. For example, 85-90% and 5-10% may be set in a plurality of stages.
At, the abnormality detection level may be set respectively. In this case, for each abnormality detection level, the number of detections is set to, for example, twice from the abnormality detection level 85 to 90% and once to the abnormality detection level 5 to 10%, so that a larger fluctuation of the rotation speed can be prevented. In this case, if the control panel 33 outputs the abnormality detection signal with a smaller number of detections, it is possible to take more appropriate countermeasures depending on the degree of the abnormality that has occurred.

[0041]

As described above, according to the present invention, the encoder provided in the servomotor detects the rotation speeds of the servomotor and the paint gear pump to monitor the discharge amount of the paint gear pump. When the paint gear pump cannot rotate or the rotation speed has dropped due to some reason such as a failure, the control unit detects the change in the rotation speed of the paint gear pump and promptly detects an abnormality such as a failure of the paint gear pump. be able to. Therefore, when such an abnormality occurs, the encoder is controlled to increase the rotation speed of the servo motor, and the servo motor and the paint gear pump are not abnormally stopped. Early detection and prediction can be performed, and the actual discharge amount can be monitored, which facilitates analysis of coating defects. As described above, according to the present invention, a discharge amount control device and a discharge amount monitoring method are provided which have a simple structure and are capable of promptly detecting the occurrence of an abnormality by monitoring the rotation speed of the paint gear pump.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a paint supply device incorporating an embodiment of a paint discharge amount control device according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a control unit in the paint discharge amount control device of FIG.

FIG. 3 is a time chart showing a control state at the time of coating by the control unit of FIG.

FIG. 4 is a time chart showing a control state at the time of cleaning by the control unit of FIG.

FIG. 5 is a schematic diagram showing a configuration of an example of a conventional paint supply device.

[Explanation of symbols]

10 Paint supply device 11 paint tank 11a paint 12 pumps 13 Regulator 20 Paint discharge rate control device 22 Paint gear pump 23 Painting machine 24 Servo motor 24a encoder 30 control unit 31 Input device 32 sequencer 33 control panel

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Akira Takarajima             1-1-1, Fujikoshihonmachi, Toyama City, Toyama Prefecture             Fuji Koshinai Co., Ltd. F-term (reference) 4D075 AA01 AA71 AA83 AA85 BB65Y                       CA47 DC11 EA07                 4F035 AA01 AA03 BA15 BA22 BB12                       BC06

Claims (8)

[Claims] 1. A paint supply device for supplying paint supplied from a paint tank to a gun tip of a coating machine by a paint gear pump at a predetermined discharge amount for coating, and a servomotor for rotationally driving the paint gear pump. And a control unit that controls rotation of the servo motor, the servo motor further includes an encoder, and the control unit detects the rotation speed of the paint gear pump based on a detection signal from the encoder. The discharge amount control device is characterized in that the discharge amount by the paint gear pump is monitored by comparing the detected rotation speed with the set rotation speed. 2. The control unit detects the number of revolutions of the paint gear pump based on a detection signal from the encoder during coating, and monitors the discharge amount of the paint by the paint gear pump. 1. The discharge amount control device according to 1. 3. The cleaning unit, when cleaning, detects the number of revolutions of the paint gear pump based on a detection signal from the encoder and monitors the discharge amount of the cleaning agent by the paint gear pump. Item 3. The discharge amount control device according to item 1 or 2. 4. The discharge amount control device according to claim 1, wherein the control unit monitors the discharge amount by the paint gear pump every predetermined sampling time. 5. The control unit detects an abnormality in the discharge amount by the paint gear pump when an error in the detected rotation speed with respect to the set rotation speed exceeds a predetermined abnormality detection level when monitoring the discharge amount by the paint gear pump. The discharge amount control device according to claim 4, wherein: 6. The discharge amount control device according to claim 5, wherein the control unit outputs an abnormality detection signal when the number of detections of discharge amount abnormality by the paint gear pump exceeds a predetermined number. 7. The discharge amount according to claim 1, wherein the control unit starts monitoring the discharge amount by the paint gear pump after a predetermined time has passed since the paint supply device was started. Control device. 8. A paint supply device for supplying paint supplied from a paint tank by a pump to a gun tip of a coating machine by a paint gear pump at a predetermined discharge amount to control rotation of a servomotor by a control unit. Then, the paint gear pump is rotationally driven by a servo motor, and the control unit detects the rotation speed of the paint gear pump based on a detection signal from an encoder provided in the servo motor, and detects the detected rotation speed and the set rotation speed. A discharge amount monitoring method, characterized in that the discharge amount by a paint gear pump is monitored by comparing with.