JPH0724386A - Method and device for controlling coated pattern width of sealing agent - Google Patents

Abstract

PURPOSE:To constantly maintain a coated pattern width of a sealing agent in the case a viscosity or injection pressure of the sealing agent is varied. CONSTITUTION:The coating pattern width of a sealing agent 1 injected out of a coating spray gun 12 is sensed, and the sensed coated pattern width is compared with an objective coated pattern width. The feeding flow rate of the sealing agent 1 to the coating gun 12 is controlled based on the deviation between the sensed coated pattern width and the target coated pattern width, and the coated pattern width of the sealing agent 1 jetted out of the coating spray gun 12 is made to conform with the objective coated pattern width.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating pattern width control method and apparatus capable of maintaining a constant coating pattern of a sealing agent even when the viscosity or discharge pressure of the sealing agent changes.

[0002]

2. Description of the Related Art Sealing agents for the purpose of preventing water from entering, vibration and soundproofing are applied to welded parts and floors of automobile bodies. The application of the sealing agent is automatically performed by a robot. The application position is taught to the robot in advance, and the sealing agent discharged from the application gun is applied along the seam of the welded portion of the vehicle body.

As a method of applying the sealing agent, there are a method of extruding the sealing agent in the shape of a rod and a method of applying it in the form of a spray. In the method of applying the sealing agent by extruding it in a rod shape, since the application gun is brought close to the application target site, there is a problem that the optimal application posture cannot be taken due to the restriction of the shape of the robot. Further, in the case of the method of extruding the sealing agent in a rod shape, there is a problem that the joint which is the application target site cannot be sufficiently filled in when the discharge pressure of the sealing agent is low.

Therefore, in recent years, spray coating, which can absorb the positional deviation of the target point by the coating pattern width and has good penetrability to the seam, is spreading. As a technique related to spray application of a sealing agent, there is known a nozzle aiming point confirmation device for confirming whether or not the reaching point of the sealing agent ejected from an application gun is accurate (Japanese Patent Publication No. 3-883).
4 publication).

[0005]

However, there are the following problems when the sealant is applied by spraying. The sealing agent has viscosity, and if the viscosity of the sealing agent changes with temperature, there is a problem that the preset coating pattern width changes. If the coating width of the sealing agent is too narrow, it will not be possible to reliably apply the sealing agent to the application target area, and if it is too wide, the sealing agent will adhere to areas other than the application target area due to overspray, or the sealing agent The coating film thickness becomes thin, and it becomes impossible to secure sufficient sealing property.

Further, the coating pattern width of the sealing agent changes depending on the fluctuation of the discharge pressure of the sealing agent. As described above, when spray-applying the sealing agent, in order to maintain the coating pattern width constant, it is necessary to adjust the temperature of the sealing agent with high accuracy and a fine adjustment of the discharge pressure by the operator. Become.

An object of the present invention is to provide a coating pattern width control method and apparatus capable of maintaining the coating pattern width of the sealing agent constant even when the viscosity and discharge pressure of the sealing agent are changed. .

[0008]

To achieve this object, a sealing agent coating pattern width control method and coating pattern width control apparatus according to the present invention are configured as follows. (1) Detecting the coating pattern width of the sealing agent ejected from the coating gun, comparing the detected coating pattern width with a preset target coating pattern width, and comparing the coating pattern width with the target coating pattern width. Controlling the supply flow rate of the sealing agent to the coating gun based on the deviation so that the coating pattern width of the sealing agent ejected from the coating gun matches the target coating pattern width. Consist of way. (2) A coating gun for ejecting a sealing agent, an imaging means for detecting a coating pattern width of the sealing agent ejected from the coating gun, a flow rate varying means for varying a supply flow rate of the sealing agent to the coating gun, The coating pattern width of the sealing agent detected by the imaging means is compared with a preset target coating pattern width, and the flow rate of the sealing agent supplied by the flow rate varying means is determined based on the deviation between the pattern width and the target coating pattern width. Control means for controlling and matching the coating pattern width of the sealing agent ejected from the coating gun with the target coating pattern width.

[0009]

In the method and apparatus for controlling the coating pattern width of the sealing agent thus configured, the sealing agent is sprayed from the coating gun in a spray form, and the sprayed coating pattern width of the sealing agent is detected. The detected coating pattern width is compared with a preset target pattern width, and the supply flow rate of the sealing agent to the coating gun is controlled based on the deviation between the coating pattern width and the target coating pattern width.

When the flow rate of the sealing agent supplied to the coating gun is controlled, the coating pattern width of the sealing agent ejected from the coating gun is corrected so as to match the target coating pattern width. In this way, the coating pattern width of the sealing agent ejected from the coating gun is adjusted by proportional control so as to match the target coating pattern width, so that the viscosity of the sealing agent changes depending on the temperature and the sealing agent is discharged. Even if the pressure fluctuates, it becomes possible to keep the coating pattern width constant.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a sealing agent coating pattern width control method and coating pattern width control apparatus according to the present invention will be described below with reference to the drawings.

FIG. 1 to FIG. 8 show an embodiment of the present invention, in particular, a case where the present invention is applied to a sealing agent applying operation by a robot. First, the configuration of the coating pattern width control device 11 will be described. 1 and 2
In the figure, 10 indicates a robot. Robot 10
An application gun 12 is attached to the tip of the arm 10a. The sealing agent 1 supplied from the plunger pump 13 is ejected in a spray form from the tip mounted on the tip of the coating gun 12. As the sealing agent 1, for example, a sealer or vinyl chloride sol is used.

The plunger pump 13 is adapted to supply a predetermined flow rate of the sealing agent 1 toward the coating gun 12. A flow rate varying means 15 including a gear pump 15a and a servomotor 15b is provided in the supply passage 14 between the plunger pump 13 and the coating gun 12. The gear pump 15a is connected to the output shaft of the servo motor 15b, and the gear pump 15a is rotated by the rotational driving force of the servo motor 15b.

Gear pump 15 connected to supply passage 14
The rotation speed of a can be adjusted by the servomotor 15b. When the rotation speed of the servo motor 15b changes, the flow rate of the sealing agent 1 discharged from the gear pump 15a changes. A flow meter 16 for measuring the flow rate of the sealing agent 1 discharged from the flow rate varying means 15 is provided between the flow rate varying means 15 in the supply passage 14 and the coating gun 12. The flow meter 16 has a function of converting the flow rate of the sealing agent 1 into an electric signal.

The coating pattern width of the sealing agent 1 ejected from the coating gun 12 is detected by a CCD camera 17 as an image pickup means. The CCD camera 17 is a one-dimensional camera, and has a function of measuring the coating pattern width as a monotonous light. CC
A light source 18 that uniformly irradiates the ejected sealing agent 1 with light is provided at a position facing the D camera 17.

FIG. 4 shows a coating pattern width of the sealing agent 1 ejected from the coating gun 12, which is electrically captured by the CCD camera 17. In the voltage waveform of FIG. 4, the light from the light source 18 passes through and the CCD camera 1
The portion captured by 7 shows a voltage near zero, and the portion blocked by both edge portions 1a of the sealing agent 1 shows a certain voltage value. The voltage changes corresponding to the edge portion 1a because the material density of the edge portion 1a is higher than that of the other portions, and the light from the light source 18 is less likely to pass therethrough.

When the slice level V of the voltage value shown in the voltage waveform of FIG. 4 is set to a predetermined value, the coating pattern width becomes CCD.
Within the field of view of the camera 17, two portions showing a voltage value equal to or higher than the slice level V occur in the voltage waveform.
The pattern width can be measured by measuring the number of bits between two locations showing a voltage equal to or higher than the slice level and converting it into the length. For example, if the field of view of the CCD camera 17 is 50 mm and the resolution is 2048 bits, then 50 mm
÷ 2048 bits = 0.024, which is 24 microns per bit. Therefore, the coating pattern width can be obtained by counting the number of bits.

Output signal of CCD camera 17 and flow meter 16
The output signal of is input to the controller 20 as a control unit. The controller 20 has a sealing agent 1
The target coating pattern width yd of is entered in advance. The controller 20, as shown in FIG.
Coating pattern width y of the sealing agent 1 detected by
(T) is compared with the target coating pattern width yd, and the deviation e between the coating pattern width y (t) and the target coating pattern width yd
Servo motor 15 of flow rate control means 15 based on (t)
It has a function of adjusting the number of revolutions of b and controlling so that the coating pattern width of the sealing agent 1 actually ejected from the coating gun 12 matches the target coating pattern width.

In this embodiment, the coating pattern width control device 1
The CCD camera 17 of No. 1 is arranged at a position slightly away from the vehicle body (not shown) that is the application target, and before the actual application of the sealing agent 1 to the vehicle body, Correction control is performed.

Next, the coating pattern width control device 1 of FIG.
The coating pattern width control method and operation according to No. 1 will be described. FIG. 5 shows a procedure of control processing of the coating pattern width. In step 100, the target pattern width y
The setting of d is performed. When the target pattern width yd is input to the controller 20, the process proceeds to step 110, where the sealing agent 1 is sprayed (trimmed), and at the same time, the pattern width of the sealing agent 1 is controlled.

In step 120, the spraying of the sealing agent 1 is performed for a predetermined time, and the control of the pattern width ends at the same time when the gun signal of the coating gun 12 is turned off. When the control of the pattern width is completed, the routine proceeds to step 130, where the rotation speed of the gear pump 15a and the rotation speed of the servomotor 15b at step 120 are stored as command values. Next, in step 140, the actual coating work is started. Here, when the gun open signal of the coating gun 12 is turned on, the gear pump 15a rotates at the number of rotations according to the stored command value, and the sealing agent 1 is discharged from the coating gun 12 with a target coating pattern width. Erupted.

FIG. 6 shows the processing procedure in step 110 of FIG. In step 110-1,
The CCD camera 17 determines whether or not the coating pattern width can be recognized. Here, when it is determined that the coating pattern width cannot be recognized, the process proceeds to step 110-4, and it is determined based on the signal from the flow meter 16 whether or not the discharge flow rate value of the sealing agent 1 is abnormal. . here,
If the flow rate is judged to be zero, the coating gun 12
It is regarded as a clogging of the chip attached to the tip of the, and the process proceeds to step 110-6, and a warning that the chip is abnormal is issued.

When it is determined in step 110-4 that the flow rate of the sealing agent 1 is normal, the process proceeds to step 110-5, and the number of edges of the voltage waveform shown in FIG. 4 is confirmed. Here, when it is determined that the number of edges is one, it is considered that the coating pattern is displaced, the process proceeds to step 110-6, and a warning that there is an abnormality is issued. When it is determined in step 110-5 that there is no edge, it is considered that the coating pattern width is too wide, and the process proceeds to step 110-7. Step 110-
In 7, the controller 20 outputs a command to the servo motor 15b to decrease the rotation speed, and the supply amount of the sealing agent 1 to the coating gun 12 is reduced.

If it is determined in step 110-1 that the coating pattern width can be recognized by the CCD camera 17, the process proceeds to step 110-2, the coating pattern width is corrected by proportional control, and step 110 is executed. −
Proceed to step 3 and proceed to the next processing.

FIG. 7 shows the processing procedure of the proportional control in step 110-2 of FIG. Step 1 of FIG.
In 10-2-1, the rotation instruction of the gear pump 15a and the servomotor 15b is given by the tabulated initial rotation speed R ₀ . The reason why the tabled initial rotation speed R ₀ is given is as follows.

Since the sealing agent 1 has a viscosity, the viscosity changes even if a fixed amount is supplied, if the temperature changes.
The coating pattern width changes. Therefore, in order to make the coating pattern width constant, as shown in FIG. 8, the relationship between the temperature and the flow rate (the rotation speed of the gear pump 15a by the servo motor 15b) is previously obtained by an experiment, and the relationship is stored in the controller 20 as table data. You are typing.

Gear pump 15a according to the initial rotation value R ₀
Is started, the process proceeds to step 110-2-2, where the actual coating pattern width y (t) and the target coating pattern yd are compared, and the coating pattern width y (t) and the target coating pattern yd are compared. The deviation e (t) from When it is determined in step 110-2-2 that the deviation e (t) = 0, the process proceeds to step 110-2-4 and proceeds to the next process.

In step 110-2-2, the deviation e
When (t) has occurred, the routine proceeds to step 110-2-3, and the control rotation speed of the servo motor 15b based on the deviation e (t) is obtained. Then, step 110-2-2
And step 110-2-3, the coating pattern width comparison and the rotation speed determination are repeated, and step 110-2-
When the deviation approaches 2 infinitely in 2, the proportional control ends.

In this way, the coating gun 12 is controlled by the proportional control.
Pattern width y of the sealing agent 1 ejected from the
Since (t) is controlled so as to match the target coating pattern width yd, the coating pattern width is kept constant even if the viscosity of the sealing agent 1 changes due to temperature change or the supply pressure of the sealing agent 1 changes. It is possible to maintain.

In this embodiment, after the coating operation of the sealing agent 1 by the robot 10 is completed, the coating pattern width due to the squirting is corrected at the waiting position of the robot 10. If the coating pattern is detected by the CCD camera 17 during movement of 12, the coating pattern can be corrected in real time.

[0031]

According to the present invention, the following effects can be obtained. (1) The coating pattern width of the sealing agent ejected from the coating gun is detected, the detected coating pattern width is compared with a preset target coating pattern width, and the deviation between the coating pattern width and the target coating pattern width is detected. Based on the control, the flow rate of the sealing agent supplied to the coating gun is controlled so that the coating pattern width of the sealing agent ejected from the coating gun matches the target coating pattern, so the viscosity of the sealing agent changes depending on the temperature, Even if the discharge pressure of the sealing agent varies, the coating pattern width of the sealing agent can be maintained constant. Therefore, the coating pattern width of the sealing agent does not become narrow or too wide due to external factors, and the quality of the sealing portion by the sealing agent can be improved. (2) It is not necessary to use a temperature control facility for adjusting the temperature of the sealing agent with high precision as in the conventional case, and the operator is not required to adjust the discharge pressure of the sealing agent. (3) Since the coating pattern width is stable, it is not necessary to use a masking material, and the preparation work and the masking material removal work in the sealing agent application work can be eliminated. Moreover, since the application of the sealing agent to the unnecessary area is eliminated, the consumption of the sealing agent can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a coating pattern width control device used to carry out a coating pattern width control method for a sealing agent according to an embodiment of the present invention.

FIG. 2 is a control system diagram of the apparatus shown in FIG.

3 is a block diagram of proportional control in the apparatus of FIG.

4 is a characteristic diagram showing the relationship between the coating pattern width of the sealing agent ejected from the coating gun of the apparatus of FIG. 1 and its voltage waveform.

5 is a flowchart showing a control process of a coating pattern width in the apparatus of FIG.

FIG. 6 is a flowchart showing a control process in step 110 of FIG.

FIG. 7 is a flowchart showing a processing procedure of proportional control in step 110-2 of FIG.

8 is a characteristic diagram showing the relationship between the temperature of the sealing agent ejected from the coating gun of the apparatus of FIG. 1 and the supply flow rate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing agent 1a Edge part 10 Robot 11 Coating pattern width control device 12 Coating gun 15 Flow rate changing means 17 Imaging means 20 Control means

Claims (2)

[Claims] 1. A coating pattern width of a sealing agent ejected from a coating gun is detected, the detected coating pattern width is compared with a preset target coating pattern width, and the coating pattern width and the target coating pattern width are compared. The sealing agent coating pattern is characterized by controlling the supply flow rate of the sealing agent to the coating gun on the basis of the deviation from the above, and matching the coating pattern width of the sealing agent ejected from the coating gun with the target coating pattern width. Width control method. 2. A coating gun for ejecting a sealing agent, an image pickup means for detecting a coating pattern width of the sealing agent jetted from the coating gun, and a flow rate varying means for varying a supply flow rate of the sealing agent to the coating gun. , Comparing the coating pattern width of the sealing agent detected by the image pickup means with a preset target coating pattern width, and supplying the sealing agent by the flow rate varying means based on the deviation between the pattern width and the target coating pattern width. A sealing agent coating pattern width control device, comprising: a control unit that controls a flow rate and matches a coating pattern width of the sealing agent ejected from the coating gun with a target coating pattern width.