JP2613548B2 - Method and system for controlling coating amount of viscous coating material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a system for controlling a coating amount of a viscous coating material such as a primer, a sealer, a paint or an adhesive.

[0002]

2. Description of the Related Art Conventionally, when a viscous application material is discharged from a nozzle and applied to a material to be applied, the amount of application is controlled in order to maintain the uniformity of the application position and the bead shape.

For example, in assembling an automobile body, a plurality of panels pressed into a predetermined shape are connected to each other by spot welding, and a sol-shaped sealer is applied to the connection portion in advance in a predetermined bead shape. Is being done. In this case, by making the application amount of the sealer uniform, a sufficient sealing effect can be obtained with a small application amount.

Conventionally, in order to control the amount of application to be uniform, a heater is installed in a hose, a pipe, a nozzle, or the like, which is a path for pressure-feeding the application material, so that the temperature of the application material becomes constant. Temperature control.

That is, the viscosity of the viscous coating material is kept constant by controlling the temperature, and under the premise that the viscosity is constant, the pumping pressure, rotation speed, nozzle opening degree, and the like are controlled. .

[0006]

However, in order to keep the temperature of the viscous coating material flowing in the pressure feeding path constant, it is necessary to circulate the viscous coating material even when the ejection from the nozzle is not performed. There is a possibility that the characteristics of the viscous coating material may be deteriorated, and there is also a problem that the coating system becomes large due to the necessity of the circulation path and its control device.

As described above, it is not easy to keep the temperature of the viscous coating material constant. Even if the temperature can be kept constant, the viscosity of the viscous coating material does not actually become constant.

That is, in the flow path of the viscous coating material, the flow path area is reduced at a joint or a bent portion of the pipe, a connection portion with a hose, and the like. It will fall.

[0009] Even if the temperature conditions and the like are the same, there may be some variation in the viscosity due to the difference in the production lot of the viscous coating material. The present invention has been made in view of the above-described problems, and provides a method and system for controlling a coating amount of a viscous coating material that can be relatively easily and highly accurately controlled so that the coating amount of the viscous coating material is uniform. Aim.

[0010]

According to a first aspect of the present invention, there is provided a method for applying a viscous material to a material to be applied by pressure-feeding a viscous material by means of a pressure-feeding device and discharging from a tip of a nozzle. , A cylinder near the nozzle
A piston sliding in the cylinder;
Cylinder and nozzle having an inner diameter smaller than
An extrusion port fluidly connected to the
A drive source that moves at a constant speed, and both ends of the extrusion port
A pressure sensor for detecting pressure, and the pressure sensor
A meter that measures viscosity based on the pressure detected by a sensor
A viscosity measurement device having a measurement operation unit is provided, the viscosity of the viscous application material is measured by the viscosity measurement device , and the application amount of the viscous application material is controlled based on the measured viscosity.

According to a second aspect of the present invention, the control of the application amount is performed by controlling a pressure fed from the pumping device. According to a third aspect of the invention, the control of the application amount is performed by controlling a relative movement speed between the nozzle and the material to be applied.

According to a fourth aspect of the present invention, there is provided a system for pressure-feeding a viscous application material, a nozzle for discharging the viscous application material and applying the viscous application material to the surface of the material to be applied, and a nozzle and the nozzle. A moving device for relatively moving the coating material and a viscosity of the viscous coating material in the vicinity of the nozzle ;
Based on the flow rate and differential pressure of the viscous coating material passing through the orifice
And a control unit for controlling at least one of the pumping pressure of the pumping device or the moving speed of the moving device based on the measured viscosity.

[0013] In the system according to the fifth aspect of the present invention, the viscosity measuring device includes a cylinder, a piston that slides in the cylinder, and an inner diameter smaller than the cylinder, and is fluidly connected to the cylinder and the nozzle. Extruded port, a driving source for moving the piston at a predetermined speed, pressure sensors for detecting pressures at both ends of the extruded port, and measurement for measuring viscosity based on the pressure detected by the pressure sensor And an operation unit.

[0014]

The coating material fed from the pressure feeding device is discharged from the nozzle and applied to the surface of the coating material in a predetermined bead shape by the relative movement of the nozzle and the coating material by the moving device.

In the vicinity of the nozzle, the viscosity of the coating material is measured by a viscosity measuring device, and the amount of coating is controlled according to the measured viscosity. The application amount is controlled by controlling the pressure of the pumping device or the moving speed of the moving device. Alternatively, it is performed by controlling the discharge amount of the viscosity measuring device.

In measuring the viscosity, a coating material having a constant flow rate is sucked or discharged from the extrusion port by moving the piston. At that time, the pressure generated at both ends of the extrusion port is detected, and the viscosity is measured based on the pressure difference.

[0017]

FIG. 1 is a block diagram showing a coating system 1 according to the present invention. In FIG. 1, a coating system 1 includes a pumping device 11 for pumping a coating material TZ, a piping 12,
13, an electromagnetic stop valve V1, a nozzle 14,
It comprises a viscosity measuring device 15, a moving device 16 for moving the nozzle 14 with respect to the work W, and a control unit 17 for controlling the whole.

The pressure feeding device 11 uses a plunger pump or the like to pressure-feed the coating material TZ filled in a tank or the like at a predetermined pressure P0. The pipe 12 is a fixed flow path for feeding the coating material TZ from the discharge port of the pressure feeding device 11 to the vicinity of the moving device 16, and the pipe 13 is configured to transfer the coating material TZ to the tip of the arm 16 a of the moving device 16. This is a flexible flow path using a hose or the like for at least a part of the flow path for sending to the nozzle 14 attached to the nozzle.

The nozzle 14 is moved by the moving device 16 so as to apply the coating material TZ discharged from the tip of the nozzle 14 on the surface of the work W in a predetermined locus. The viscosity measuring device 15 includes a cylinder 21 having an inner diameter d (for example, 20 mm), a piston 22 that seals and slides the inner surface of the cylinder 21, and an orifice having an inner diameter D (for example, 1 to 4 mm) and a length L. The push-out port 23, a screw-type moving mechanism 24 connected to the piston 22, a motor M for moving and driving the piston 22 via the moving mechanism 24, a driver 25 for controlling the speed of the motor M, and detecting a stroke position of the piston 22. Sensors LS1 and LS2 and pressure sensor P
S1, S2, a measurement control unit 26, a display unit 27, and the like.

The viscosity measuring device 15 measures the flow rate Q passing through the extrusion port 23 and the differential pressure ΔP between both ends of the extrusion port 23 for the coating material TZ on the upstream side immediately before the stop valve V2 provided in the nozzle 14. Is used to measure the viscosity μ. The measurement by the viscosity measuring device 15 is performed when the coating material TZ is sucked into the cylinder 21 and when the cylinder 21
This is performed both at the time of discharge from the nozzle (at the time of extrusion). At the time of discharge from the cylinder 21, the coating material TZ is discharged from the nozzle 14 by this.

That is, first, with the stop valve V2 closed, the motor M rotates at a constant speed,
The piston 22 moves upward in FIG. 1 at the speed Vp. Then, the coating material TZ flows into the cylinder 21 via the extrusion port 23 by the pressure P0 of the pressure feeding device 11.
At this time, the flow rate Q is determined by the rotation speed of the motor M, and the differential pressure ΔP is determined as the difference between the detected pressures of the pressure sensors PS1 and PS2. From these, the viscosity μ is determined based on the following equation (1). Can be

[0022] ΔP = A × μ × Q × L / D 4 ...... (1) where, A: correction coefficient The flow rate Q is determined from the following equation (2).

[0023] ^{Q = (πd 2/4)} × Vp ...... (2) In response to such a viscosity determined in the mu, the control unit 17 and the driver 25 from the measurement control unit 26 RS232
The signal SD by the 2C interface is output.

The signals SD are, for example, six-stage signals SD1 to SD6 corresponding to the level of the viscosity μ.
The rotation speed of the motor M at the time of discharging from the cylinder 21 is controlled.

That is, in a state where the stop valve V2 is opened and the stop valve V1 is closed, the motor M rotates in the opposite direction to the above, and the coating material TZ is discharged from the extrusion port 23 and discharged from the nozzle 14. Is done. At this time, when the measured viscosity μ is low, the rotational speed of the motor M, that is, the speed Vp, is controlled to be low, and when the viscosity μ is high, the speed Vp is controlled to be high. Is controlled to be constant.

While the coating material TZ is being discharged from the nozzle 14, the nozzle 14 is moved at a constant speed v with respect to the work W by the moving device 16, and a bead having a predetermined locus is formed on the surface of the work W. You.

When the coating material TZ in the cylinder 21 is discharged, the viscosity μ is obtained in the same manner as when suctioning. The obtained viscosity μ is displayed on the display unit 27. The position sensors LS1 and LS2 determine the speed V of the piston 22.
It is used as a timing for detecting a section in which p is constant and detecting the viscosity μ in that section.

Further, the coating material TZ is discharged from the nozzle 14 without being discharged from the cylinder 21.
The discharge may be performed by the pressure from the pressure feeding device 11. In that case, the pressure P0 of the application material TZ by the pressure feeding device 11 is controlled by the six-stage signals SD1 to SD6 corresponding to the level of the viscosity μ.

That is, in this case, the pressure P0 is controlled so as to decrease when the viscosity μ is low, and to increase the pressure P0 when the viscosity μ is high. , 2 open and nozzle 1
4 discharges the coating material TZ.

That is, upon discharging from the nozzle 14, first, the stop valve V1 is opened, and after a short delay, the stop valve V2 is opened. Further, the stop valve V2 is closed slightly after the stop valve V1 is closed. Since the coating material TZ is discharged from the nozzle 14 at a constant flow rate while the stop valve V2 is open, the nozzle 14 is moved at a constant speed v with respect to the work W by the moving device 16 during that time. A bead having a predetermined locus is formed on the surface of W.

As described above, when the coating material TZ is applied to the work W by the nozzle 14, the viscosity μ of the coating material TZ near the nozzle 14 is measured each time the coating is performed, and the measured viscosity is measured. The rotation speed of the motor M or the pressure P0 from the pressure feeding device 11 is controlled in accordance with μ to control the discharge amount from the nozzle 14 to be constant.

Therefore, it is possible to easily and precisely control the amount of application to the work W without controlling the temperature of the application material TZ. Further, even when the viscosity changes due to a change in the cross-sectional area in the pipe lines 12, 13 or a variation in the characteristics of the coating material TZ, the changed viscosity is measured by the viscosity measuring device 15, and the discharge amount is controlled accordingly. Is performed, so that the amount of application can be always constant.

Thus, the amount of the coating material TZ applied to the work W can be made close to the optimum value, the consumption of the coating material TZ can be reduced, and the excess amount of the coating material TZ can be reduced.
Dirt can be prevented. Further, since it is not always necessary to perform temperature control, and it is not necessary to circulate the coating material TZ, the configuration of the coating system 1 is simplified, and equipment costs can be reduced.

Since the discharge amount from the nozzle 14 is constant, the usage amount of the coating material TZ can be accurately grasped.
The supply of the coating material TZ in the pressure feeding device 11 can be accurately performed.

In the above embodiment, the opening and closing timings of the two stop valves V1 and V2 are slightly shifted at the time of application by the nozzle 14, so that pressure builds up in the pipe line 13 due to expansion of the pipe line 13. Is prevented, and the coating material TZ is prevented from jumping out of the nozzle 14.

In the above-described embodiment, when outputting the signal SD, a table for outputting the signals SD1 to SD6 according to the level of the viscosity μ is stored in the measurement control unit 26, and the table is referred to. You may do so. Although the signal SD of six steps corresponding to the viscosity μ was output, it may be five steps or less, seven steps or more, or no step.

In the above-described embodiment, it is not always necessary to calculate the viscosity μ itself when measuring the viscosity μ by the measurement control unit 26. That is, data corresponding to the measured differential pressure ΔP or to the differential pressure ΔP or the viscosity μ,
The speed Vp or the pressure P0 can be controlled by obtaining data corresponding to a change in the differential pressure ΔP or the viscosity μ.

In the above-described embodiment, in order to make the coating amount uniform, the discharge amount is controlled to be constant in accordance with the measured viscosity μ. However, without controlling the discharge amount, or The moving speed v of the nozzle 14 by the moving device 16 may be controlled. That is, when the viscosity μ is low, the discharge amount increases, so that the speed v is increased. Conversely, when the viscosity μ is high, the speed v is decreased.

In the above embodiment, the work W
The viscosity μ was measured each time the coating was performed.
The viscosity μ may be measured once or more than once each time the coating is performed.

In the above embodiment, the measurement control unit 26
Can be realized by a CPU board or the like having an appropriate interface circuit. In FIG. 1, the driver 25 and the measurement control unit 26 of the viscosity measurement device 15 and the overall control unit 17 of the coating system 1 are shown as different configurations, but they may be configured by a single control unit. Good.

In the above embodiment, the position sensor LS
As 1 and 2, photoelectric type, magnetic sensitive type and other various types are used. The configuration and operation timing of the pumping device 11, the nozzle 14, the viscosity measuring device 15, the moving device 16, the control unit 17, and the like can be variously changed according to the gist of the present invention.

[0042]

According to the present invention, control can be performed relatively easily and with high accuracy so that the application amount of the viscous application material is uniform. For example, even when the viscosity changes due to a change in the cross-sectional area in the piping or a variation in the characteristics of the coating material, the coating amount can be controlled uniformly.

Accordingly, the amount of the coating material applied to the material to be coated can be made closer to the optimum value, the consumption of the coating material can be reduced, and the excess coating material can be prevented from dripping and dirt. . Further, since it is not always necessary to control the temperature and it is not necessary to circulate the coating material, the configuration of the coating amount control system is simplified, and the equipment cost can be reduced.

Further, it is possible to accurately grasp the usage amount of the coating material while keeping the discharge amount from the nozzle constant, so that the supply of the coating material in the pressure feeding device can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a coating system according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating system (coating amount control system) 11 pressure feeding device 12 pipe line 14 nozzle 15 viscosity measuring device 16 moving device 17 control unit 21 cylinder 22 piston 23 extrusion port 26 measurement control unit (measurement calculation unit) PS1, PS2 pressure sensor TZ coating Material (viscous coating material) W Workpiece (material to be coated) M Motor (drive source)

Claims (5)

(57) [Claims] When a viscous application material is pressure-fed by a pressure-feeding device and discharged from a tip of a nozzle to be applied to a material to be coated , a cylinder is provided near the nozzle, and a cylinder is provided inside the cylinder.
The piston that slides inside the cylinder smaller than the cylinder
Having a diameter and fluidly connected to the cylinder and nozzle.
And the piston is moved at a predetermined speed.
The drive source and the pressure at both ends of the extrusion port are detected, respectively.
And a pressure sensor detected by the pressure sensor.
A measuring operation unit for measuring the viscosity based on the pressure.
A viscosity measuring device is provided, the viscosity of the viscous coating material is measured by the viscosity measuring device , and the application amount of the viscous coating material is controlled based on the measured viscosity. Quantity control method. 2. A coating amount control method according to claim 1, wherein the control of the coating amount, the coating amount control method of the viscous coating material, which comprises carrying out by controlling the pressure for pumping from the pumping device. 3. The method according to claim 1, wherein the control of the coating amount is performed by controlling a relative moving speed between the nozzle and the material to be coated. Application amount control method. 4. A pressure feeding device for feeding a viscous application material, a nozzle for discharging the viscous application material and applying the viscous application material to a surface of the material to be applied, and a relative movement between the nozzle and the material to be applied. a moving device, the viscosity of the viscous coating material in the vicinity of the nozzle, Orifice
A viscosity measuring device for measuring based on the flow rate and the differential pressure of the viscous coating material passing through the disk, and a pressure of the pumping device or a movement of the moving device based on the measured viscosity. And a control unit for controlling at least one of the speeds. 5. The coating amount control system according to claim 4, wherein the viscosity measuring device includes: a cylinder; a piston that slides in the cylinder; and a fluid having an inner diameter smaller than the cylinder and being supplied to the cylinder and the nozzle. An extrusion port, which is connected in series, a drive source that moves the piston at a predetermined speed, pressure sensors that detect the pressures at both ends of the extrusion port, and a viscosity based on the pressure detected by the pressure sensor. A measurement operation part for measuring, and a coating amount control system for a viscous coating material, comprising: