JPH0889860A - Color switching device - Google Patents

Abstract

PURPOSE: To provide a color switching device which can be arranged near a coating gun even when a coating robot is used, and reduce the loss of coating and the consumption of a thinner for cleaning during color change on account of the shortening of a common tubular path. CONSTITUTION: This color switching device comprises a coating gun connected to coating feed sources 2, and a single coating gun 1 applies a variety of color coatings. In addition, this device is equipped with a check valve unit 4 comprising a check valve arranged in each bifurcated tubular path part of a manifold with a trunk tubular path part having one end connected to a coating gun side and the other end being closed, and the bifurcated tubular path parts having one end being open to the trunk tubular path part and the other end connected to each coating feed source part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color changing device for supplying a plurality of paints having different colors to a coating gun and applying multicolored coatings with one coating gun.

[0002]

2. Description of the Related Art Conventionally, in a coating line for automobiles,
A color changing device that sequentially switches and supplies paint of a desired color to the coating gun so that one paint gun can paint multi-color paints when sequentially painting car bodies with different coating colors. Is provided.

As shown in FIG. 5, a conventional paint supply device having such a color changing device includes a paint gun 51 fixed to an automatic painter (painting robot) in a paint booth and a paint gun outside the paint booth. A paint supply source (paint tank, paint pump, etc.) 52 installed in a paint store, and a color change valve (CCV), which is a color changing device, between the paint gun 51 and the paint supply source 52. 54 are arranged and connected by paint pipes 53a and 53b. Although not shown, a trigger valve (discharge valve) that opens when the paint is discharged is provided inside the coating gun.

The color change valve 54 that has been conventionally used is provided with a main conduit portion communicating with the paint pipe 53b, a plurality of branch conduit portions branching from the main conduit portion, and the branch conduit portions, respectively. The plurality of open / close valves are unitized, and paints A, B, ... Having different colors are connected to the respective branch pipe portions, and the color change valve 54 to the painting gun 51 are connected. Piping 53b
Cleaning thinner and cleaning air 55 for cleaning the inside
Is connected. Then, the switching valve in the color change valve 54 is selected by the air signal sent from the control unit 56 of the color changing device, and desired paint, thinner or air is supplied to the coating gun 51 side. (For example, refer to JP-A-1-317569, 2-261565, and 5-300335.)

[0005]

However, a color changing device including such a color change valve has a large opening / closing valve itself and requires an air hose for sending an air signal for operating the opening / closing valve. ,
The size was large. Therefore, when painting with a painting robot, the color change valve cannot be installed near the painting gun,
It was installed near the base of the robot arm, and the length of the paint pipe connecting the color change valve and the painting gun was long. At the time of color change, since the paint remaining in the paint pipe is washed and removed as described above, there is a problem that the loss of the paint and the thinner for cleaning increases.

Therefore, it is an object of the present invention to provide a color changing device which is lightweight and miniaturized. The present invention further provides a color changing device which can be arranged in the vicinity of a coating gun even when a painting robot is used, and which can reduce the loss of paint during color changing and the amount of thinner used for cleaning. It is an issue.

[0007]

SUMMARY OF THE INVENTION The present invention for solving the above-mentioned problems is a color changing device in which a plurality of paint supply sources are connected to a coating gun to apply multi-colored paint with one coating gun. A main conduit portion connected to the coating gun side and closed at the other end; and a plurality of branch conduit portions having one end opened to the main conduit portion and the other end connected to each paint supply source side. It is a color changing device having a check valve unit in which a check valve is arranged at each of the branch conduits of the manifold.

In the color changing device of the present invention, a circulation pipe branching from this supply pipe and returning to the paint supply side is provided in the middle of each paint supply pipe connecting each paint supply source and the check valve unit. It is desirable that a three-way valve that is provided and that switches between the supply line side and the circulation line side is provided at this branch portion.

In the color changing device of the present invention, it is also preferable that the check valve unit is installed near the coating gun.

In the color changing device of the present invention, the check valve unit is open at one end to the closed other end of the trunk conduit and is connected to the cleaning fluid source side at the other end. It is desirable that the cleaning fluid further includes a cleaning fluid pipe provided with an opening / closing valve.

In the color changing device of the present invention, the diameter of each branch conduit in the check valve unit is 0.8 to 3.0 m at least at the opening portion to the trunk conduit.
It is desirable that it is m.

[0012]

In the color changing device of the present invention, by using the check valve unit as described above, from the pipe line specific to each color paint, which is continuous from each paint supply source, to the common pipe line connected to the coating gun. A check valve is installed in each inflow part to prevent backflow of other colors to the pipe line unique to each color paint, enabling color change painting, equipped with an on-off valve that controls opening and closing with conventional air Unlike the CCV unit, since the air hose for operating the valve is not required and the valve itself is small, the check valve unit is small and lightweight. Therefore, in the mode in which the coating robot is used, the degree of freedom of movement of the robot can be secured even if the check valve unit is installed near the coating gun. In addition, by installing it near the coating gun in this way, the common pipeline can be shortened, and the loss of paint and cleaning thinner can be reduced when cleaning and removing the paint remaining in this common pipeline during color change. it can.

Further, in the color changing device of the present invention, the paint is selectively supplied from each paint supply source to the coating gun through the check valve unit in a predetermined period. This operation is performed by each paint supply source. In the middle of each paint supply pipe connecting the check valve unit and the check valve unit, a circulation pipe branching from this supply pipe and returning to the paint supply source side is provided, and the branch pipe is connected to the supply pipe side and the circulation pipe side. If a three-way valve for switching is provided, the switching can be performed only by switching the three-way valve, and the color changing operation can be performed easily and stably without the need to sequentially operate and stop the pressure pump.

Further, the check valve unit is provided with an opening / closing valve which is open at one end to the closed other end of the trunk conduit and is connected to the cleaning fluid source side at the other end. If the washing line is further provided, it can be applied to a color change in which a color mixture such as red to white is noticeable.

Further, it is desirable that the diameter of each branch conduit in the check valve unit is as thin as 0.8 to 3.0 mm at least at the opening portion to the trunk conduit. When the thickness is 3.0 mm or less, it is possible to more reliably prevent the coating material from mixing into the main pipeline portion which is the common pipeline, and when it exceeds 0.8 mm, it is possible to prevent the coating material from being clogged.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a piping system diagram showing the overall configuration of an embodiment of the present invention, FIGS. 2 (a) to 2 (c) are three-sided views showing the configuration of a check valve unit used in the same embodiment of the present invention, and FIG. FIG. 4 is a schematic diagram showing the configuration in the vicinity of the coating gun of the same embodiment, and FIG. 4 is a color change time chart of the same embodiment.

As shown in FIG. 1, the color changing device of the present embodiment is provided with a color A and a color B installed outside the coating booth and in the paint storage.
A check valve unit 4 is provided between a paint supply source (paint tank and paint pump, etc.) 2 of 8 colors having different colors such as C, C, D, ... And a paint gun 1 fixed to a paint robot in a paint booth. It is connected by paint pipes 3a and 3b via. In FIG. 1, for simplification, the A and D color pipes are mainly drawn.

This check valve unit 4 is shown in FIG.
As shown in (a) to (c), the trunk line portion 5 having one end connected to the coating gun 1 side (paint pipe 3b) and the other end closed.
And each branch of the manifold 7 having one branch opening 6 at one end and eight branch conduits 6 having the other end connected to the paint supply source 2 side (paint pipe 3a). A check valve 9 is arranged in the pipe section 6. In this embodiment, eight check valves are unitized so as to correspond to the eight paint supply sources 2, but the number thereof is not limited at all, and it depends on the number of paint supply sources 2. It is changed appropriately. Compared with the open / close valve used in the conventional color changing device, the check valve 9 itself is sufficiently small, and an air hose or the like for controlling the open / close operation thereof is not required. Even if it is unitized, it can be sufficiently miniaturized. Further, in this embodiment, as shown in FIG. 2 (c), each branch conduit 6 is alternately arranged to the right in a cross section perpendicular to the axis of the trunk conduit 5 with respect to the trunk conduit 5. The unit is miniaturized by using a so-called V-shaped array in which the units are connected at an equal interval from diagonally above or diagonally above, but the arrangement of the branch pipe section 6 or the check valve 9 is not particularly limited. As described above, since the check valve unit 4 is extremely small and lightweight, it can be mounted together with the coating gun 1 on the coating gun mounting portion 11 at the arm tip of the coating robot 10, as shown in FIG. The paint pipe 3b connecting the paint gun 1 and the check valve unit 4 can be made very short. Even if the check valve unit 4 is installed in the vicinity of the coating gun 1, the degree of freedom of movement of the coating robot 10 can be sufficiently ensured.

The diameter of each branch conduit 6 depends on the viscosity of the paint used, but is 0.8 to 3.0 at least at the opening to the trunk conduit 5.
mm is desirable. It is desirable that the diameter of each branch conduit 6 is 3.0 mm or less, which is sufficiently small in order to prevent color mixture due to leakage of the non-selective paint into the trunk conduit 5, and 0.8 mm. It is desirable to exceed the above value in order to prevent the paint from clogging.

In addition, in the check valve unit 4 of this embodiment, one end is opened at the other closed end of the trunk conduit 5, and the other end is provided with cleaning air and a cleaning thinner supply part. There is further provided a wash fluid line section 13 with an on-off valve 12 connected to 17. The cleaning fluid conduit 13 is provided for cleaning the common conduit (the main conduit 5, the paint pipe 3b, and the paint gun 1 inner conduit).

By having the check valve 9 as described above, in the color changing device of the present invention, the backflow of other colors from the common pipeline side is prevented, and the unselected (unpressurized) coating material is prevented. Leakage to the common pipeline will be suppressed, but since it does not have a complete opening / closing function, it is necessary for each paint supply source side to pump the paint when it is selected and to stop the pumping when it is not selected. You have to do it. In the present embodiment, a circulation pipe line 14 that branches from the paint pipe 3a and returns to the paint supply source 2 side is provided in the middle of each paint pipe 3a from the paint supply source 2 to the check valve unit 4. A three-way valve 15 is arranged at the branch portion, and by selectively switching the three-way valve 15, the paint can be selectively supplied, and the operability and the structure are simplified. A gear pump 1 operated by a drive unit 15 as a paint pressure feeding means is provided in the circulation line 14.
6 is arranged.

Although not shown, a trigger valve that opens when the paint is discharged is provided inside the coating gun 1.

The paint color change using the color change device of this embodiment is performed as follows. For example, when changing the color from A to D, as shown in FIG. 4, first, the three-way valve 15 in the middle of the A color paint pipe 3a is shown in synchronization with the opening and closing of the trigger valve in the coating gun 1. A signal from the control mechanism is switched from the circulation line 14 side to the coating gun 1 side, and the color A is coated with a predetermined discharge amount. When this A-color coating is completed (T ₀ ), the three-way valve 15 in the middle of the A-color paint pipe 3a is switched to the circulation pipe line 14 side, and the opening / closing valve 12 of the cleaning fluid pipe line 13 is opened to switch not shown. By operating the valve, the cleaning air and the cleaning thinner are alternately supplied from the supply unit 17 to the main pipeline section 5, and the A color paint remaining in the main pipeline section 5, the paint pipe 3b and the coating gun 1 is applied to the coating gun. Dispose from the tip of 1 in the coating booth. Since the change valve unit 4 is arranged close to the coating gun 1 as described above, the common pipe (paint pipe 3b) is very short, and therefore the amount of A-color paint remaining here is small and required for cleaning. The thinner amount is small and the cleaning time (T _{0 to} T ₁ ) is shortened. At the stage (T ₁ ) where these washings are completed, the trunk line portion 5 and the paint pipe 3b
The inside of the coating gun 1 is washed with the A-color paint and filled with only the washing air. Then, in order to supply the D color to be applied next, the on-off valve 12 of the cleaning fluid line 13 is closed, and the three-way valve 15 in the middle of the D color paint pipe 3a is opened from the circulation side to the gun side with the trigger valve opened. Switch to the, paint gun with D color paint from the viewpoint of preventing color mixing and stabilizing the discharge rate 1
After discarding a little from the tip of (T _{1 to} T ₂ ), the three-way valve 15 in the middle of the D color paint pipe 3 a is synchronized with the opening and closing of the trigger valve in the same way as in the case of A color coating, and the gun Switch to the side and apply D color with a predetermined discharge amount. A color changing operation to another color is similarly performed.

The washing process (T _{0 to} T ₁ ) performed during the color change as described above takes a relatively long time to change the color change from conspicuous color mixture, for example, red to white. Change the process time appropriately according to the combination of the current paint color and the next paint color in the color change, for example, it takes a relatively short time to change the color from dark green to dark blue. You can also do it. Further, in the color change in which the color mixture is not conspicuous, such a washing step (T _{0 to} T ₁ ) is omitted, and after the color change, before the actual coating, the paint is slightly applied from the tip of the coating gun 1 to a coating booth or the like. It is also possible to deal only with the operation to be discarded. In the color changing device of the present invention, as described above, the common pipe is very short and the amount of residual paint is small,
It is possible to sufficiently deal with such an operation alone.

The color changing apparatus of the present invention as described above can be used for color change in various kinds of painting such as car body painting, but especially, the color of the intermediate coating paint (including co-color painting) in car body painting. It can be preferably used for color change of replacement and clear paint coating.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments and can be appropriately modified within the scope of the present invention. For example, in the above embodiment, the check valve unit is provided with the cleaning fluid pipeline having the opening / closing valve, but such a cleaning fluid pipeline may not be provided, and the cleaning fluid pipeline may also be checked. It is also possible to use a valve. Further, in the color changing device of the present invention, the pipe line configuration other than having such a check valve unit, or the presence or absence of the arrangement of auxiliary equipment such as a flow meter and a flow controller is optional.

[0027]

As described above, according to the present invention, a trunk conduit portion having one end connected to the coating gun side and the other end closed,
A check valve is arranged in each of the branch conduits of a manifold having one end opened to the trunk conduit and the other end having a plurality of branch conduits connected to the paint supply source side. Since the check valve unit is configured to connect multiple paint sources to the coating gun, the valve unit (branching from the common pipeline to each paint source without sacrificing the robot's freedom of movement even when using a painting robot) It is possible to dispose the branch portion) that is close to the coating gun, and to reduce the loss of paint and cleaning thinner when changing colors.

Further, in the color changing device of the present invention, a circulation pipe branching from this supply pipe to the paint supply source side in the middle of each paint supply pipe connecting each paint supply source and the check valve unit. If a three-way valve that switches between the supply line side and the circulation line side is provided at this branch part, it is possible to perform a simple and stable color change operation without the need to sequentially operate and stop the pressure pump. Can be done.

Further, in the color changing device of the present invention, the check valve unit is opened at one end to the closed other end of the trunk conduit and is connected to the cleaning fluid source side at the other end. If the cleaning fluid pipe having the opening / closing valve is provided, it can be sufficiently applied to the color change in which the color mixture is conspicuous.

Furthermore, in the color changing device of the present invention, the diameter of each of the branch conduits in the check valve unit is at least 0.
When the thickness is 8 to 3.0 mm, it is possible to more reliably prevent the mixture of the paint from entering the common conduit, prevent the clogging of the paint, and achieve a better color change coating.

[Brief description of drawings]

FIG. 1 is a piping system diagram showing an overall configuration of an embodiment of a color changing device of the present invention,

2A is a plan view showing the configuration of a check valve unit used in the embodiment of the present invention, FIG. 2B is a front view of the check valve unit, and FIG. 2C is a side view of the check valve unit. ,

FIG. 3 is a schematic diagram showing the configuration in the vicinity of the coating gun of the same embodiment,

FIG. 4 is a color change time chart of the embodiment,

FIG. 5 is a piping system diagram showing a configuration of an example of a conventional color changing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Painting gun, 2 ... Paint supply source, 3a, 3b ... Paint piping, 4 ... Check valve unit, 10 ... Painting robot.

Claims (5)

[Claims] 1. A method for connecting a plurality of paint sources to a coating gun,
A color changing device for applying multicolor paints with one coating gun, one end of which is connected to the coating gun side and the other end of which is closed, and one end of which is open to the main conduit and the other end. A color changer having a check valve unit in which a check valve is arranged in each of the branch pipe lines of a manifold having a plurality of branch pipe lines connected to the paint supply source side. apparatus. 2. A circulation pipe line that branches from this supply pipe line and returns to the paint supply source side is provided in the middle of each paint supply pipe line connecting each paint supply source and the check valve unit, and this branch line is provided. The color changing device according to claim 1, wherein the part is provided with a three-way valve for switching between the supply pipeline side and the circulation pipeline side. 3. The color changing device according to claim 1, wherein the check valve unit is installed near a coating gun. 4. The check valve unit includes an opening / closing valve that opens at one end of the closed other end of the trunk conduit and is connected to the cleaning fluid source side at the other end. The color changing device according to claim 1, further comprising a cleaning fluid pipe line. 5. The check valve unit, wherein the diameter of each branch conduit is 0.8 to 3.0 mm at least at an opening portion to the trunk conduit.
4. The color changing device according to any one of 4.