JP2890672B2 - Paint supply device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION (Industrial Application Field) The present invention relates to a paint supply device for supplying paint to a paint gun, and in particular, is configured to be able to automatically perform a switching point at the time of paint color change. It was done.

(Prior art) In the top coating process of automobiles, etc., a color changing device is provided in the paint supply device to apply multi-color paint with one coating gun. For this purpose, an apparatus has been proposed in which the supply of paint is stopped during coating and air is injected behind paint remaining in the paint hose. (For example, JP-A-63-63,144).

As shown in FIG. 5, the paint supply apparatus includes a paint gun 1 fixed to an automatic painting machine in a paint booth and a paint supply source (paint tank and paint pump) installed outside the paint booth and in a paint storage. 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 as a color changing device is attached to the pipes 3a and 3b.

To the color change valve 4, paints having different colors (only two colors are shown for convenience in FIG. 5) are connected, and the inside of a pipe 3b from the color change valve 4 to the tip of the coating gun 1 is cleaned. The cleaning thinner 5 and the extrusion air 6 are connected via a three-way valve 7 at the cleaning end. The three-way valve 7 has a paint pipe 9 for supplying another cleaning thinner 8 by a gear pump 14, The paint pipe 9 is connected to the paint pipe 9 via an air supply unit 12 through which an air injection path 11 for guiding air 13 used for pushing out paint at the time of color change.

On the other hand, the paint pipe 9 is connected to a pressure regulating pipe 15 for adjusting the pressure of the cleaning thinner in the pipe to adjust the pressure of the air injected behind the residual paint.
The pressure 16 is regulated by the regulator 17 and supplied to the paint pipe 9. And this regulator 17
Is adjusted by inputting a signal from the pressure transducer 18 attached to the paint pipe 3b to the electropneumatic converter 21 via the converter 19 and the CPU unit 20, and adjusting the pressure of the control air 22. .

The color change of the conventional paint supply device configured as described above is performed as follows.

That is, after the air 13 is supplied to the paint pipe 9 between the air supply unit 12 and the three-way valve 7 in advance, the cleaning is performed from the pressure regulating pipe 15 to regulate the pressure of the injection air according to the paint pressure in the paint pipe 3b. A thinner 16 is supplied. When the color change is performed from this state, the supply of the previous color paint is stopped by the color change valve 4, and at the same time, the paint pipes 9 and 3b are brought into conduction by the three-way valve 7, and the three-way valve 23 is operated. The cleaning thinner 8 flows through the paint pipe 9. As a result, a constant amount of the residual paint is pushed out by the cleaning thinner 8, but since the air injected behind the residual paint in the paint pipe 3b is regulated in accordance with the discharge pressure, the paint is supplied at the time of supply. The coating can be continued under the same coating conditions as above, and the residual coating can be used effectively.

Then, after the residual paint is almost used for painting, the three-way valve 7 is operated to make the paint pipe 9 and the discharge pipe 10 conductive, and the fixed amount extrusion is completed. Thereafter, the extrusion air 6 and the cleaning thinner 5 are alternately supplied to the color change valve 4 to clean the inside of the paint pipe 3b. And
Next, the paint to be painted is supplied to the color change valve 4 to wait for the workpiece to arrive.

(Problems to be Solved by the Invention) However, the point at which the paint supply device stops the supply of paint from the color change valve 4 and switches to quantitative extrusion coating by the cleaning thinner 8 is input to the control device of the paint supply device in advance. In addition, since the amount of paint to be ejected usually differs for each paint color, it is necessary to set a switching point for each paint color. In particular, since the setting of the paint discharge amount is changed in accordance with the seasonal variation, the switching point must be reset 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 effective use of the residual paint.

The present invention has been made in view of such problems of the related art, and it is possible to effectively use the paint remaining in the paint pipe and automatically set a switching point to the quantitative extrusion coating. It is an object of the present invention to provide a paint supply device which can be used.

(Means for Solving the Problems) In order to achieve the above object, a paint supply device of the present invention is provided with a color change valve in the middle of a paint pipe connecting a paint supply source and a paint gun. And the supply of the paint is stopped during the painting, and the painting is continued by quantitatively supplying the cleaning solvent from the upstream side of the paint remaining in the paint pipe. In the paint supply device configured as described above, the paint pipe connecting the color change valve and the paint gun is provided with an integrating flow meter and paint checking means, and the paint checking means confirms that paint is present in the paint pipe. The flow rate of the paint flowing through the paint pipe is measured at a predetermined time, and when the measured value reaches a predetermined value, a paint cutoff signal is sent to the color change valve. It is characterized in that dispensing the cleaning solvent from an upstream side of the residual paint outputs.

(Operation) In the present invention configured as described above, since the discharge amount discharged from the coating gun varies depending on the coating color, the paint is supplied to the coating gun from the color change valve in advance, and the paint in the paint pipe is checked by the paint checking means. After confirming the presence, measure the flow rate with an integrating flow meter.

In the subsequent coating, when the paint was supplied from the color change valve, the flow rate was measured by the integrating flow meter with the paint confirmation means confirming the presence of the paint in the paint pipe, and the measured flow rate reached the above-mentioned reference value. At this time, a signal for terminating the supply of the paint is output to the color change valve, and the solvent for cleaning is supplied quantitatively from the upstream side of the residual paint to continue the coating.

As a result, not only can the residual paint in the paint pipe be used effectively, but even when the discharge amount changes, the switching point to the extrusion painting by the solvent can be automatically set and executed. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

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

First, as shown in FIG. 1, a paint supply device according to the present embodiment includes a coating gun 1 fixed to an automatic coating machine in a coating booth.
And a paint supply source 2 installed outside the paint booth and in a paint storage. The paint gun 1 and the paint supply source 2 are connected by a plurality of paint pipes. In this plumbing,
Color change valve (CCV) 4 as a color changing device, paint regulator 25 as a discharge amount control device, paint flow meter 26, ON-OFF valve 2 for discharging and shutting off paint
7 is installed.

The color change valve 4 and the paint supply source 2 are connected by a paint pipe 30, and paints A, B,.
Are connected to each switching valve (valve member) of the color change valve 4. Also, the color change valve 4 has
From this color change valve 4 to a switching valve 4 described later
A cleaning thinner 28 (pipe 91) for cleaning the inside of the paint pipes 31, 32, 34 reaching 0, 41 and an extrusion air 29 are connected. Then, a switching valve in the color change valve 4 is selected by an air signal sent from a control unit of a color changing device (not shown), and desired paint, thinner, or air is supplied to the coating gun 1 side.

A control air 45 for controlling the paint regulator is supplied to a paint regulator 25 attached downstream of the color change valve 4 via an electropneumatic converter or the like (not shown).
The amount of paint A, B,.

On the other hand, the ON-OFF valve 27 performs ON / OFF operation according to a control signal from the air source 46, and controls supply and stop of the paint supplied from the paint regulator 25 to the paint gun 1 side.

The paint pipe 31 according to the present embodiment is configured to be branched into two downstream by a three-way valve 44 and to be joined again by 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 (pipe 92) for cleaning the inside of the paint pipe 33 and an extrusion air 29
Is connected. The paint and the like supplied by the paint pipe 32 can be switched between the paint pipe 33 side and the waste 51 side. In addition, a switching valve 41 is provided in the other pipe 34.
Cleaning thinner 28 (Piping 9
3) and the extrusion air 29 are connected, and paint piping 3
The paint and the like supplied by 4 are configured to be switched between the paint pipe 35 side and the waste 52 side.

Further, the switching valves 40 and 41 are connected to the paint, the cleaning thinner and the extrusion air supplied from the color change valve 4 by the pipes 32 and 34, the cleaning thinner supplied by the pipes 92 and 93, and the extrusion air. It is designed to switch selectively.

The paint pipes 33 and 35 are connected to a switching valve 42, respectively. The switching valve 42 has a cleaning thinner 28 (piping 94) for cleaning the inside of the pipe 36 and an air 29 for extrusion.
Is connected. The paint and the like supplied by the paint pipes 33 and 35 can be switched between the paint pipe 36 side and the waste 53 and 54 sides. Further, the switching valve 42 selectively switches between the paint supplied by the paint pipes 33 and 35, the cleaning thinner and the extrusion air, and the cleaning thinner supplied by the pipe 94 and the extrusion air.

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

The paint supply device of this embodiment is the same as the cleaning thinner 28 described above.
In addition, a thinner source 60 for quantitative extrusion is provided, and a pipe 61
Is connected to the cleaning thinner pipe 90 described above.
A regulator 62 and a gear pump 63 are provided in a pipe 61 of the thinner source 60 for quantitative extrusion, and a reflux pipe 65 is connected by a three-way valve 64. “66” is a flow meter, and “67” is a check valve.

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

In the paint supply device of the present embodiment, paint piping 33, 35
Pressure sensors (paint checking means) 70 and 71 are attached to the controller, and it is determined whether or not the paint is filled in the flowmeter 26. That is, when air enters the flow meter 26, the flow rate indicated value indicates an abnormal value, so that the presence of paint in the paint pipe is detected by the pressure sensors 70, 71. To enter. The flow meter is read only when the paint exists in the pipe. The flow meter 26 can perform flow integration,
This integrated value data is transmitted to the control means 72. The control means 72 calculates a switching point of the color change valve 4 based on the pressure data from the pressure sensors 70 and 71 and the flow rate data from the integrating flow meter 26, and outputs the calculated change point to the color change valve 4.

When a new color or the like is newly applied, the control means 72 of the paint supply device of this embodiment first calculates and stores a reference usage amount [V] of the paint. That is, as shown in FIG. 2, in a state where the constant-rate extrusion from the cleaning thinner 60 is stopped (step 1), the color change valve 4 is switched to supply the paint to the paint pipes 31, 32, 33, 36, and 37. Start (step 2). At this time, it is confirmed by the pressure sensor 70 that the paint is filled in the paint pipe (step 3).
Immediately after that, the flow meter starts integrating the flow rate (step 4). When the paint has finished reading the flow meter integrated value V _0, it calculates a reference amount [V] by the following equation (step 5-7).

[V] = V ₀ + V ₃ −V ₁ Here, V ₁ is the capacity of the paint in the pipe from the flow meter 26 to the pressure sensor 70, and V ₃ is the margin capacity for fluctuation in the discharge amount.

The reference usage amount [V] of the new paint color calculated in this manner is stored in the control means 72 (step 8). Therefore, when the discharge amount setting is changed due to seasonal variation not only for the new color but also for the conventional color, the reference operation amount can be automatically calculated simply by performing the above operation.

Next, using the reference usage amount [V] of each coating color described above,
The control for calculating the point at which to switch to the thinner extrusion coating at the time of color change will be described.

As shown in FIG. 3, when performing a color change, the color change valve 4 is switched to apply the paint to the pipes 31, 32, 33, 36, 37.
When the paint reaches the pressure sensor 70 and indicates a predetermined pressure, the flow meter 26 starts integration (steps 1 to 5).
5). The integrated value V detected by the flow meter 26 while the paint is sprayed from the coating gun 1 on the workpiece.
Is confirmed to have reached the reference usage amount [V] described above (steps 6 and 7), the supply of the paint from the color change valve 4 is stopped, the valve 96 is closed, and the three-way valve 64 is operated. Pipeline 61, 9
It is supplied to the rear side of the residual paint through 2 (step 8).

On the other hand, when the color change is not performed, that is, when the paint of the same paint color is continuously applied (Steps 1 → 2 → 9), the flow rate integration is started with the start of the coating from the coating gun (Step 9). 10), the integrated value is the pressure sensor 70
The pipe coating capacity up spray gun 1 tip when the V ₄ from continuing to supply paint from the color change valve 4 until [V-V4], to confirm that a [V-V4] (Steps 11 and 12), the supply of the paint from the color change valve 4 is stopped. At the same time, a thinner 60 for quantitative extrusion is supplied into the pipe (step 8).

Further, the operation of the whole paint supply apparatus of this embodiment will be described with reference to a color change time chart of FIG. In addition,
This color change time chart shows the operation when the color is changed from A to B.

First, the color change valve 4 is opened to supply the color A paint to the pipe 31. At this time, the three-way valve 44
Opening in the direction passing through 2, 33, the paint of A color reaches the coating gun 1 via the pipes 36, 37.

According to the conventional paint supply apparatus, the color change valve 4 is opened while the work is being painted. In this embodiment, the supply of the color A paint of the color change valve 4 is stopped during the painting. Instead of paint piping 33,36,37
Is extruded with a thinner 60 for quantitative extrusion.

That is, while the A color paint at the start t ₀ of t ₁ is the paint pipe
The 31,32,33,36,37 Although color A paint is supplied, as described above o'clock t _1, automatically detected by the pressure sensor 71, the integrated flow meter 26 and the control unit 72, color The change valve 4 is switched, and the air 29 for extrusion and the washing thinner 28 are alternately supplied to the paint pipe 31 to wash the inside of the paint pipes 31 and 32, and the washing thinner 28 and the like are discarded from the waste pipe 51. On the other hand, in between t ₁ ~t _3, while closing the valve 96 switches the switching valve 40 to the thinner side for quantitatively extruding, the paint pipe 33 for quantitatively extruding thinner 60 via a pipe 61,92 by Kiyaponpu 63 Supply. As a result, the residual paint of color A supplied after the paint pipe 33 is pushed by the thinner 60 for quantitative extrusion, and moreover,
Since the discharge amount of the thinner 60 for fixed-quantity extrusion is controlled by the gear pump 63, the discharge amount of the A-color paint from the coating gun 1 is maintained as it is, and the coating can be continued.

When finished painting of color A at t ₀ ~t _3, supplies a cleaning thinner 28 to the pipe 92, 94, 95 by opening the valve 96. That is,
The paint pipe 33 is cleaned by supplying the cleaning thinner 28 via the pipe 92, and at the same time, the pipe 36 is cleaned by supplying the cleaning thinner via the pipe 94. The pipe 37 is cleaned by supplying a thinner. When cleaning such a paint pipe, the cleaning thinner and the air for extrusion are alternately supplied as in the conventional cleaning cycle. Generally, as shown in the color change time chart, paint piping 33, 35
Is the longest, so that sufficient cleaning time is taken.

The next color supply is performed in parallel with the cleaning of the paint pipe. That is, since the washing of the paint pipe 31 is performed between t ₁ and t ₂ , when this washing is completed, the color change valve 4 is switched, and the three-way valve 44 is switched to the paint pipe 34 side. supplies color B paint is the next color in the 34,35 (t ₂ ~t _4). On the other hand, cleaning of paint piping 36 and 37
Since at _4:00 and ends, after which the washing is finished, and supplies the B color paint pipe 36,37 (t ₄ ~t _5).

As described above, according to the paint supply device of the present embodiment, in order to effectively use the residual paint, the paint supply during the painting is stopped and the switching point to shift to the thinner extrusion painting is automatically detected and switched. In addition, the labor required for maintenance of the paint supply operation can be reduced as compared with the operation of setting the switching point, which is conventionally performed manually.

The present invention can be variously modified without being limited to the above-described embodiments. For example, in the above-described embodiment, a paint supply apparatus in which it is not preferable to use a gear pump for a pressure pump, such as a metallic base paint, has been described. The present invention can also be embodied by a paint supply device that can be applied to paint that does not cause any support for cleaning.

(Effect of the Invention) As described above, according to the paint supply device of the present invention, the paint remaining in the paint pipe can be effectively used, and the switching point to the thinner extrusion coating is automatically set. This makes it possible to reduce the man-hour required for device maintenance.

[Brief description of the drawings]

FIG. 1 is a piping system diagram showing one embodiment of the present invention, FIG. 2 is a flowchart in executing automatic measurement of paint usage amount in the embodiment, and FIG. 3 is executing thinner extrusion in the embodiment. FIG. 4 is a color change time chart of the embodiment, and FIG. 5 is a piping diagram showing a conventional paint supply device. DESCRIPTION OF SYMBOLS 1 ... Painting gun, 2 ... Paint supply source, 4 ... Color change valve, 26 ... Integrated flow meter, 30-37 ... Paint piping, 70, 71 ... Pressure sensor (paint confirmation means), 72 ... Control means.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B05B 12 / 14,15 / 02 B05C 11/10

Claims (1)

(57) [Claims] A color change valve is provided in a paint pipe connecting a paint supply source and a paint gun, and a paint discharged from the paint gun is selected by the color change valve. In the paint supply device configured to discontinue the supply of the paint and to continue the coating by quantitatively supplying the cleaning solvent from the upstream side of the paint remaining in the paint pipe, the color change valve and the coating gun are provided. An integrating flow meter and paint checking means are provided in the paint pipe to be connected, and the flow rate of the paint flowing through the paint pipe is measured with the paint checking means confirming that the paint is present in the paint pipe. When a predetermined value is reached, a paint cutoff signal is output to the color change valve and a cleaning solvent is supplied from the upstream side of the residual paint in a fixed amount. A paint supply device, characterized in that: