JPH0422458A - Paint supply apparatus - Google Patents

Abstract

PURPOSE:To reduce paint loss at the time of color change by providing an integrating flowmeter and a paint confirming means to the paint piping connecting a color change valve and a painting gun, and measuring the flow rate of the paint flowing through the paint piping and quantitatively supplying a washing solvent from the upstream part of the residual paint, when the measured value reaches a predetermined value. CONSTITUTION:A color change valve 4 is opened to supply A-color paint to piping 31. At this time, for example, a three-way valve 44 is opened to the direction passing through pipings 32, 33 and the A-color paint reaches a painting gun 1 through pipings 36, 37. During the period from the painting start time t0 of the A-color paint to a time t1, the A-color paint is supplied to the paint pipings 31, 32, 33, 36, 37, but the time t1 is automatically detected by pressure sensors 70, 71, an integrating flowmeter 26 and a control means 72 to change over the change valve 4, and extrusion air and a washing thinner 28 are alternately supplied to the paint piping 31 to wash the paint pipings 31, 32. By this method, the number of processes required in the maintenance of the apparatus can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a paint supply device that supplies paint to a paint gun, and in particular is configured to automatically change the switching point when changing paint colors. This is what I did.

(Prior art) In the top coating process of automobiles, etc., a paint supply device is equipped with a color changing device in order to apply multiple colors of paint with one paint gun. For this purpose, a device has been proposed that stops the supply of paint during painting and injects air behind the paint remaining in the paint hose (for example, Japanese Utility Model Application No. 63-63.144).
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As shown in Figure 5, this paint supply device consists of a paint gun 1 fixed to an automatic paint machine inside the paint booth and a paint supply source (a paint tank and a paint pump) installed on the paint floor outside the paint booth. etc.) 2, and paint pipes 3a and 3b are provided between the paint gun 1 and the paint supply source 2. A color change valve (CCV) 4, which is a color change device, is attached to the pipes 3a and 3b.

The color change valve 4 is connected to paints of different colors (only two colors are shown in FIG. 5 for convenience), and the inside of the piping 3b from the color change valve 4 to the tip of the paint gun 1 is connected to the color change valve 4. Thinner 5 for cleaning pots
and extrusion air 6 are connected via a three-way valve 7 at the cleaning end, and this three-way valve 7 is connected to a paint pipe 9 that supplies another cleaning thinner 8 with a gear pump 14, and a discharge pipe 10.
The paint pipe 9 is also connected to an air injection path 11 via an air supply unit 12 for guiding air 13 used for pushing out the paint during color change.

On the other hand, a pressure regulating plumber 5 is connected to the paint pipe 9 to adjust the pressure of the cleaning thinner in the pipe to adjust the pressure of the air injected behind the residual paint, and the cleaning thinner 16 is connected to a regulator. The pressure is regulated by 17 and the paint is supplied to the paint pipe 9. The adjustment of the regulator 17 is performed by transmitting a signal from the pressure transducer 18 attached to the paint pipe 3b to the converter 19 and the CPU.
The air is inputted to the electro-pneumatic converter 21 via the unit 20, and the pressure of the control air 22 is adjusted.

Color changing in the conventional paint supply device configured as described above is performed as follows.

That is, after the air 13 is supplied in advance to the paint pipe 9 between the air supply unit 12 and the three-way valve 7, the pressure regulating pipe 15 is
A cleaning thinner 16 is supplied from the paint pipe 3b to adjust the pressure of the injected air according to the paint pressure in the paint pipe 3b. When changing the color from this state, the color change valve 4 stops the supply of the previous color paint, the three-way valve 7 connects the paint pipes 9 and 3b, and the three-way valve 23
is activated so that the cleaning thinner 8 flows through the paint pipe 9. This causes the cleaning thinner 8 to extrude a fixed amount of the residual paint, but since the air injected behind the residual paint in the paint pipe 3b is regulated according to the discharge pressure, when the paint is supplied, Painting can be continued under the same painting conditions as before, and the remaining paint can be used effectively.

Then, after most of the remaining paint has been used for painting, the three-way valve 7 is operated to bring the paint pipe 9 and the discharge pipe 10 into communication, thereby completing the quantitative extrusion.

After this, extrusion air 6 and cleaning thinner 5 are alternately supplied to the color change valve 4 to clean the inside of the paint pipe 3b. Then, the paint to be applied next is supplied to the color change valve 4, and the process waits for the workpiece to arrive.

(Problem to be Solved by the Invention) However, in this paint supply device, the point of stopping the paint supply from the color change valve 4 and switching to constant extrusion painting using the cleaning thinner 8 is that the control device of the paint supply device is set in advance. It is necessary to enter the information, and
Since the amount of paint discharged usually differs for each color, the switching pound also needs to be set for each color. In particular, since the setting of the paint discharge amount is changed according to seasonal variations, the switching point must be set again every time the setting is changed, which is extremely complicated.

On the other hand, setting a constant switching point regardless of the paint color is not preferable because it deviates from the original purpose of effectively utilizing residual paint.

The present invention was made in view of the problems of the prior art, and it is possible to effectively utilize the paint remaining in the paint pipe and to automatically set the switching point to quantitative extrusion painting. The purpose is to provide a paint supply device that can.

(Means for Solving the Problems) To achieve the above object, the paint supply device of the present invention provides a color change valve in the middle of a paint pipe connecting a paint supply source and a paint gun, and uses this color change valve to paint a paint. The paint is configured to select the paint discharged from the gun, and furthermore, the supply of the paint is stopped in the middle of painting, and the painting is continued by supplying a fixed amount of cleaning solvent from the upstream side of the paint remaining in the paint pipe. In the paint supply device configured to When the measured value reaches a predetermined value, a paint discontinuation signal is output to the color change valve, and the cleaning solvent is quantified from the upstream side of the remaining paint. It is characterized by supplying

(Function) The present invention configured as described above supplies paint from the color change valve to the paint gun in advance, and checks the amount of paint in the paint pipe using the paint confirmation means, since the amount of paint discharged from the paint gun differs depending on the paint color. After confirming its presence, measure the flow rate using an integrated flowmeter.

In the subsequent painting process, when the paint is supplied from the color change valve, the presence of paint in the paint piping is confirmed by the paint confirmation means, and the flow rate is measured by the integrated flowmeter.
When the measured flow rate reaches the reference value mentioned above, it outputs a signal to stop the paint supply to the color change valve, and
Painting is continued by supplying a fixed amount of cleaning solvent from the upstream side of the remaining paint.

This not only makes it possible to effectively use the residual paint in the paint pipes, but also automatically sets and executes the switchover point to extrusion painting using solvents, even if the discharge rate changes. .

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

Figure 1 is a piping system diagram showing one embodiment of the present invention, and is an example of a paint supply system in which it is not preferable to use a gear pump, such as for metallic base paints, and Figure 2 shows the amount of paint used in the same embodiment. FIG. 3 is a flowchart when executing automatic measurement of 1, FIG. 3 is a flowchart when executing thinner extrusion in the same embodiment, and FIG. 4 is a color change time chart in the same embodiment.

First, as shown in FIG. 1, the paint supply device of this embodiment consists of a paint gun l fixed to an automatic paint machine inside the paint booth, and a paint supply source 2 installed outside the paint booth in the paint storage.
The paint gun 1 and the paint supply source 2 are connected by a plurality of paint pipes. This piping includes a color change valve (CCV) 4 that is a color change device, a paint regulator 25 that is a discharge amount control device, a paint flow meter 26, and an ON-OF valve that controls paint discharge and shutoff.
An F valve 27 is attached.

The color change valve 4 and the paint supply source 2 are connected by a paint pipe 30, and paints A and B, each having a different color, are connected to each other by a paint pipe 30.
, . . . are connected to each switching valve (valve member) of the color change valve 4. In addition, the color change valve 4 is supplied with δ for cleaning the inside of the paint pipes 31, 32, 34 leading from the color change valve 4 to the switching valve 40, 41, which will be described later. Air 29 is connected. Then, a switching valve in the color change valve 4 is selected by an air booster sent from a control section of a color change device (not shown), and a desired paint, paint, or air is supplied to the painting gun 1 side.

Control air 45 for controlling the paint regulator is supplied to the paint regulator 25 installed downstream of the color change valve 4 via an electro-pneumatic converter (not shown), etc., and the control air 45 controls the paint gun 1. The discharge amount of paints A, B, . . . to be supplied to is determined.

On the other hand, the 0N-OFF valve 27 performs 0N10FF operation based on the IQ control signal from the air source 46, and controls the supply and stop of the paint supplied from the paint regulator 25 to the painting gun 1 side.

The paint pipe 3 unit according to this embodiment is configured to be branched into two parts toward the downstream side by a three-way valve 44, and to be joined again at a switching valve 42.

Another switching valve 40 is provided in one of the branched paint pipes 32, and in addition to the paint, a cleaning thinner 28 (piping 92) for cleaning the inside of the paint pipe 33 and extrusion air 29 are connected. ing. The paint and the like supplied through the paint pipe 32 can be switched between the paint pipe 33 side and the waste 51 side. Further, the other pipe 34 is provided with a switching valve 41, and this switching valve 41 is also connected to not only paint but also cleaning thinner 28 (piping 93) and extrusion air 29 for cleaning the inside of the paint pipe 35. The paint and the like supplied through the paint pipe 34 can be switched between the paint pipe 35 side and the waste 52 side.

Furthermore, these switching valves 40.41 are connected to the paint supplied from the color change valve 4 through the piping 32.34.
The cleaning thinner, the extrusion air, the cleaning thinner supplied through the pipes 92 and 93, and the extrusion air are selectively switched.

The paint pipes 33 and 35 are each connected to a switching valve 42, and to the switching valve 42, a cleaning thinner 28 (piping 94) for cleaning the inside of the pipe 36 and extrusion air 29 are connected. And the paint pipe 33
．． It is configured so that the paint etc. supplied by 35 can be switched between the paint pipe 36 side and the waste disposal 5B, 54 side. This switching valve 42 selectively switches between the paint, cleaning thinner, and extrusion air supplied through the paint piping 33 and 35, and the cleaning thinner and extrusion air supplied through the piping 94.

The paint pipe 36 is connected to a switching valve 43, and a cleaning thinner 28 (piping 95) for cleaning the inside of the pipe 37 and extrusion air 29 are connected to the switching valve 43. The paint and the like supplied through the paint pipe 36 can be switched between the paint pipe 37 side and the waste 55 side. Furthermore, this switching valve 4
3 selectively switches between the paint, cleaning thinner, and extrusion air supplied by the paint pipe 36 and the cleaning thinner and extrusion air supplied by the pipe 95.

The paint supply device of this embodiment uses the cleaning thinner 28 described above.
In addition, it has a thinner source 60 for quantitative extrusion, which is connected to the cleaning thinner pipe 90 described above through a pipe 61. The piping 61 of this thinner source 60 for quantitative extrusion includes
A regulator 62 and a gear pump 63 are provided, and a recirculation pipe 65 is connected via a three-way valve 64 . In addition, "66" is a flow meter, and "67" is a check valve.

A valve 96 provided in the cleaning thinner pipe 90
When closed, the regulator 62 and gear pump 63 discharge cleaning thinner at a fixed amount to the pipes 92 to 95.
It is now possible to supply On the other hand, when this valve 96 is opened, thinner pumped from the cleaning thinner 28 side at a predetermined pressure is supplied to the pipes 92 to 95.

In the paint supply device of this embodiment, the paint pipe 33.3
A pressure sensor (paint confirmation means) 70, 71 is attached to the flow meter 26 to determine whether or not the flow meter 26 is filled with paint. That is, if air enters the flowmeter 26, the flow rate indication value will show an abnormal value, so this pressure sensor 70.
At step 71, this detection signal is input to the control means 72 in order to detect the presence of paint in the paint pipe. and,
The flow meter is configured to read only when paint is present in the pipe. The flow meter 26 is capable of performing flow integration, and this integrated value data is transmitted to the control means 72. This control means 72 uses pressure data from the pressure sensors 70 and 71 mentioned above and the integrated flow meter 26.
Color change valve 4 based on flow data from
The switching point is calculated and output to the color change valve 4.

In the control means 72 of the paint supply device of this embodiment, when a new color or the like is to be applied, the standard usage amount [V] of this paint is calculated and stored.

That is, as shown in FIG. 2, with the fixed amount extrusion from the cleaning thinner 60 stopped (step 1), the color change valve 4 is switched, and the paint pipes 31, 32, 33, 3
Start supplying paint at 6.37 (Step 2). At this time, immediately after confirming that the paint pipe is filled with paint using the pressure sensor 70 (step 3), the flow meter starts integrating the flow rate (step 4). When the painting is completed, the flow meter integrated value V. is read and the reference usage amount [Vl is calculated using the following formula (steps 5 to 7).

[Vl = Vo + v3 - V1 Note that Vl is the volume of paint in the pipe from the flow meter 26 to the pressure sensor 70, and v3 is the margin for fluctuations in the discharge transmission.

The new paint color standard use ffi calculated in this way
[Vl is stored in the control means 72 (step 8).

Therefore, when changing the discharge amount setting due to seasonal variations not only for new colors but also for conventional colors, the standard usage amount can be easily calculated automatically by performing the above operation.

Next, a description will be given of control for calculating the point at which to switch to thinner extrusion painting at the time of color change using the reference use fi [Vl of each of the above-mentioned paint colors.

As shown in Fig. 3, when changing the color, switch the color change valve 4 and apply the paint to the piping
．． 36 and 37, and when the paint reaches the pressure sensor 70 and indicates a predetermined pressure, the flow meter 26 starts integrating (steps 1 to 5). Then, while spraying paint from the paint gun 1 onto the workpiece, it is confirmed that the integrated value V detected by the flow meter 26 has reached the reference usage amount [Vl] (steps 6 to 7). , the supply of paint from the color change valve 4 is stopped, the valve 96 is closed, and the three-way valve 64 is operated to supply the thinner 60 for quantitative extrusion to the rear side of the residual paint via the pipes 61 and 92 (step 8).

On the other hand, if you do not change the color, that is, if you apply the same paint color continuously (steps 1-2 → 9),
When the painting starts from the painting gun, flow rate integration is started (steps 9 to 10), and the integrated value is detected by the pressure sensor 70.
If the paint capacity in the pipe from 1 to the tip of painting gun 1 is V4, continue to supply paint from color change valve 4 until [V-V4] is reached, and confirm that it is [V-V4]. (Steps 11 and 12) Stop the paint supply from the color change valve 4. At the same time, a fixed amount of extrusion thinner 60 is supplied into the pipe (step 8).

Furthermore, the overall operation of the paint supply device of this embodiment will be explained with reference to the color change time chart of FIG. Note that this color change time chart shows the effect when changing the color from color A to color B.

First, the color change valve 4 is opened and the paint of color A is supplied to the pipe 31. At this time, the three-way valve 44 opens in the direction of passing through the pipes 32 and 33, for example, and the A-colored paint passes through the pipes 32 and 33.
6.37 to the paint gun 1.

According to the conventional paint supply device, the color change valve 4 is open while the workpiece is being painted, but in this embodiment, the supply of color A paint from the color change valve 4 is stopped in the middle of painting. , instead, paint piping 33, 36
．． The A color paint at 37 is extruded using quantitative extrusion thinner 60.

In other words, the time t when color A coating starts. From tl to tl, A color paint is supplied to the paint pipes 31, 32.33, 36.37, but as mentioned above at time t1, the pressure sensors 70, 71
, the color change valve 4 is automatically detected by the integrated flow meter 26 and the control means 72, and the color change valve 4 is switched.
1, extrusion air 29 and cleaning thinner 28 are alternately supplied to clean the inside of the paint pipes 31 and 32, and this cleaning thinner 28 and the like are discarded from the waste pipe 51.

On the other hand, between t and t3, the valve 96 is closed, the switching valve 40 is switched to the thinner for quantitative extrusion, and the gear pump 63 supplies the thinner 60 for quantitative extrusion to the paint pipe 33 via the pipe 6192. As a result, the residual paint of color A supplied from the paint pipe 33 onward is pushed back by the quantitative extrusion thinner 60, and since the discharge teeth of this quantitative extrusion thinner 60 are controlled by the gear pump 63, , the discharging teeth of the color A paint from the paint gun 1 are maintained as they are, and painting can be continued.

1,) to t3, the valve 96 is completed.
is opened and the cleaning thinner 28 is supplied to the pipes 92, 94, and 95. That is, the paint pipe 33 is cleaned by supplying the cleaning thinner 28 through the pipe 92, and at the same time, the pipe 36 is cleaned by supplying the cleaning thinner through the pipe 94. The pipe 37 is cleaned by supplying cleaning thinner. When cleaning such paint pipes, cleaning thinner and extrusion air are supplied alternately, as in the conventional cleaning cycle. Note that, as shown in the color change time chart, the paint pipe 33°35 is generally the longest, so sufficient cleaning time is taken.

The next color is supplied in parallel with such cleaning of the paint piping. That is, since cleaning of the paint pipe 31 is performed between t1 and t2, when this cleaning is completed, the color change valve 4 is switched and the three-way valve 44 is switched to the paint pipe 3.
Switching to the 4th side, the next 8 colors of paint are supplied into the paint pipes 31, 34, and 35 (t2 to t4). On the other hand, since the cleaning of the paint pipes 36 and 37 ends at time t4, after this cleaning is completed, color B is supplied to the paint pipes 36 and 37 (t4 to ts).

As described above, the paint supply device of this embodiment is configured to automatically detect and switch to the switching point at which the paint supply during painting is stopped and transitioned to thinner extrusion painting in order to effectively utilize the remaining paint. , compared to the conventional manual switching point setting operation,
The effort spent on maintenance of the paint supply device can be reduced.

Note that the present invention is not limited to the embodiments described above, and can be modified in various ways. For example, in the above-mentioned embodiment, a paint supply device was explained in which it is not preferable to use a gear pump for pressure pumping, such as for metallic base paints, but even if a gear pump is used for solid paints or clear paints, the paint It can also be embodied by a paint supply device which can be applied to paints that do not require any support during cleaning.

(Effects of the Invention) As described above, according to the paint supply device of the present invention, the residual paint in the paint pipe can be effectively used, and the switching point to thinner extrusion painting can be automatically set. This makes it possible to reduce the number of man-hours required for equipment maintenance.

[Brief explanation of the drawing]

Fig. 1 is a piping system diagram showing one embodiment of the present invention, Fig. 2 is a flowchart for automatically measuring the amount of paint used in the same embodiment, and Fig. 3 is a flowchart for executing thinner extrusion in the same embodiment. FIG. 4 is a color change time chart of the same embodiment, and FIG. 5 is a piping system diagram showing a conventional paint supply device. DESCRIPTION OF SYMBOLS 1... Paint gun, 2... Paint supply source, 4... Color change valve, 26... Integral flow meter, 30-37... Paint piping, 7
0.71...Pressure sensor (paint confirmation means), 72...
- Control means.

Claims (1)

[Claims] A color change valve is provided in the middle of a paint pipe connecting a paint supply source and a paint gun, and the color change valve is configured to select the paint to be discharged from the paint gun. In addition to discontinuing the supply of the paint,
In the paint supply device configured to continue painting by supplying a fixed amount of cleaning solvent from the upstream side of the paint remaining in the paint pipe, an integrated flow meter is installed in the paint pipe connecting the color change valve and the paint gun. and a paint confirmation means, and with the paint confirmation means confirming the presence of paint in the paint pipe, the flow rate of the paint flowing through the paint pipe is measured, and when this measured value reaches a predetermined value. A paint supply device characterized in that, at the same time, a paint discontinuation signal is output to the color change valve and a cleaning solvent is supplied in a fixed amount from an upstream side of residual paint.