JPH05154418A - Coating device and method for using the device - Google Patents

Abstract

PURPOSE:To reduce the consumption of thinners for washing and coating materials. CONSTITUTION:The device has a color change valve 1 connected with plural coating material supplying systems 2, 2,... and a coating gun 4 connected to the color change valve 1 via a coating material supplying path 5. A bypass passage 6 provided with a flow meter 7 is connected in parallel with the coating material supplying passage 5 and selector valves 18, 19 which are synchronously selected in such a manner that the coating materials flow either of the coating material supplying passage 5 and the bypass passage 6 are provided. The coating materials are passed only to the bypass passage 6 by selecting the selector valves 18, 19 prior to the start of coating and the flow rates are measured by the flow meter 7 for each of the respective coating material supplying systems 2, 2,... at the time of use. The bypass passage 6 and the flow meter 7 are internally washed after the end of the measurement. The coating is started by selecting the selector valves 18, 19 and passing the coating materials only to the coating material supplying passage 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for changing a coating color by selectively opening a plurality of coating supply systems and a method of using the coating apparatus.

[0002]

2. Description of the Related Art Conventionally, as a coating apparatus of this type,
There is known one provided with a color change valve for converting the color of the paint blown out from the coating gun (see, for example, JP-A-60-61076). Further, generally, in a coating apparatus, a flow meter for measuring the discharge flow rate from the coating gun is interposed in series in a coating material supply passage to the coating gun (for example, Japanese Patent Laid-Open No. 56-139162).
(See the official gazette). In the case of such a coating apparatus, every time the coating color is changed by the color change valve according to the coating target, the coating material of the previous color remaining in the coating material supply passage is washed away by the cleaning liquid such as thinner. The paint of this color is passed through the paint supply passage.

[0003]

However, in the above-mentioned conventional coating apparatus, not only the paint supply passage is cleaned but also the inside of the flow meter interposed in the paint supply passage is cleaned every time the coating color is changed. There is a need. The inside of this flowmeter is relatively complicated, and extra cleaning liquid is required for that amount.
The paint that remains in the flowmeter and is washed away is wasted. Moreover, when the object to be coated is a vehicle body on a production line of an automobile, in order to make the number of vehicle bodies of each color uniform, it is necessary to convert the coating color for each vehicle body sequentially conveyed to the coating line of the production line. The number of cleanings also increases in proportion to the number of conversions. That is, when the coating color is converted for each vehicle body, even if the type of the coating color is, for example, 4 to 7, it is necessary to wash as many as the number of vehicle bodies to be coated. The consumption of cleaning thinner and the loss of residual paint are considerable.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the loss of paints and thinners for cleaning, and to reduce the amount of consumption. ..

[0005]

In order to achieve the above object, the invention according to claim 1 is such that a plurality of paint supply systems corresponding to paints for respective colors are connected, and only one paint supply system is selectively selected. A color change valve for switching to an open state and a coating gun to which the paint is supplied from each of the paint supply systems via the color change valve. Further, a paint supply passage connecting the paint gun and the color change valve is provided with a bypass passage branched from the upstream side position and joined at the downstream side position, and a flow meter is provided in the bypass passage, At the branching and merging points,
Two switching valves which are synchronously switched so that the paint from the color change valve to the coating gun is allowed to flow into only one of the paint supply passage and the bypass passage are provided.

Further, in the method of using the coating apparatus according to the first aspect of the present invention, after the switching valve is switched to a flow rate measuring state in which the paint flows only in the bypass passage before the start of coating, the color change valve is opened. The coating material supply system is sequentially switched and the flow rate of the coating material supplied to each coating material supply system is measured by a flow meter, and after the flow rate measurement of all the paint supply systems is completed, the inside of the bypass passage and the flow meter are cleaned. Then, after this, the switching valve is switched to a paint supply state in which the paint flows only in the paint supply passage, and coating is started.While the coating is continued, the switching valve is maintained in the paint supply state even if the coating color is changed. It is configured to

[0007]

With the above construction, in the invention according to claim 1,
Since a bypass passage is provided separately from the paint supply passage for supplying paint from the color change valve to the coating gun, and a flow meter is provided in this bypass passage, the paint is switched to flow only through the paint supply passage during painting. Even if the coating color is changed by switching the valve to shut off the bypass passage, only the paint supply passage needs to be washed, and it is not necessary to wash the bypass passage and the flow meter every time the coating color is changed.

According to the second aspect of the present invention, before the coating is started, the flow rate is switched to the flow rate measuring state and the paint is supplied to the bypass passage provided with the flow meter to measure the flow rate of each paint supply system to start the coating. After that, since the paint supply state is switched to shut off the bypass passage, the flow meter need only be cleaned once when the flow rate measurement is completed. No need to clean the meter.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a coating apparatus according to an embodiment of the present invention, in which 1 is a color change valve, 2, 2, ...
Is a plurality of (seven in the illustrated example) paint supply systems for supplying paint to the color change valve 1 for each color, 3 is a cleaning fluid supply passage for supplying a cleaning fluid such as thinner to the color change valve 1, 4 is a A coating gun to which the color change valve 1 supplies a paint of a fixed color for each vehicle body to be coated, 5 is a paint supply passage for supplying the paint gun 4 with paint from the color change valve 1, and 6 is this paint. Bypass passage provided in the supply passage 5, 7 is a flow meter provided in the bypass passage 6, and 8 is the coating gun 4
Is a curing agent supply passage for supplying the curing agent to. Note that FIG.
Now, the configuration of only one coating supply system 2 of the plurality of coating supply systems 2, 2, ... Is shown in detail, and the other six coating supply systems have the same configurations as those described above. Illustration is omitted.

The color change valve 1 has seven inlet ports (not shown), one outlet port and one cleaning port, and each of the seven paint supply systems 2, 2, ... The paint supply passage 5 is connected to the outlet port, and the cleaning fluid supply passage 3 is connected to the cleaning port. The color change valve 1 selectively opens only the paint supply system 2 of the paint of a predetermined color for each vehicle body, and the paint of that color is applied to the coating gun 4 through the paint supply passage 5. The paint supply system 2, 2, ... Is supplied and the paints of other colors are closed.

Each of the paint supply systems 2 supplies a paint for each color from a paint mixing room (not shown) to the pressure adjusting valve 9 at a relatively high pressure (for example, about 3.0 Kg / cm ² ). 2a, a secondary side paint supply passage 2b for supplying the paint whose pressure is adjusted to a relatively low pressure (for example, about 1.0 kg / cm ² ) by the pressure adjusting valve 9 to the color change valve 1, and the pressure adjusting valve. 9, a primary return passage 2c that branches from the primary-side paint supply passage 2a on the upstream side to return the paint in the primary-side paint supply passage 2a, and a secondary side that branches from the upstream side of the color change valve 1 A secondary return passage 2d for returning the paint in the side paint supply passage 2b to the downstream side of the pressure control valve 9 and a pump for pumping the paint provided in the secondary paint supply passage 2b. 10 and a pulsation absorbing accumulator 11. The pump 10 is composed of a piston pump, and pressure-feeds the paint by repeating the suction stroke and the discharge stroke. The pulsation absorbing accumulator 11 is the pump due to the cushioning action of the compressed air filled inside. The pulsation associated with the suction and discharge strokes of 10 is absorbed. In FIG. 1, 12 is a filter provided on the outlet side of the pressure regulating valve 9 for removing fine dust in the paint, and 13 is a regulator.

The cleaning fluid supply passage 3 comprises a thinner supply passage 3a, an air supply passage 3b, an opening / closing valve 14a for opening / closing the thinner supply passage 3a, and an opening / closing valve 14b for opening / closing the air supply passage 3b. .. Both of the on-off valves 14a and 14b are switched to the open state by introducing air signals 16a and 16b (shown only in FIG. 2) as ON signals based on the opening operation on the control panel 15.

A static mixer 17 is interposed in a paint supply passage 5 between the coating gun 4 and the color change valve 1, and a downstream end of a curing agent supply passage 8 is connected to the static mixer 17.

The bypass passage 6 branches off from the paint supply passage 5 at a portion between the static mixer 17 and the color change valve 1 by a three-way switching valve 18 provided at an upstream position of the paint supply passage 5. 3-way switching valve 1 installed in
They are connected so that they merge at 9. These two three-way switching valves 18, 19 are supplied with air signals 18a, 19a (shown only in FIG. 2) as ON signals based on the paint supply state as the normal position and the switching operation on the control panel 15. It is possible to mutually switch synchronously between the flow rate measurement state in which the valve is driven. In the paint supply state, the paint supply passage 5 is communicated by the two three-way switching valves 18 and 19 and the inflow to the bypass passage 6 is blocked, and as a result, the paint from the color change valve 1 is blocked. Is supplied to the static mixer 17 through the paint supply passage 5 between the two three-way switching valves 18 and 19, and the bypass passage 6 is closed at its upper and lower ends. Further, in the flow rate measuring state, the paint supply passage 5 is shut off by the both three-way switching valves 18 and 19 and the bypass passage 6 is communicated, and as a result, the color change valve 1 The paint is supplied to the static mixer 17 through the bypass passage 6 and the flow meter 7, and the paint supply passage 5 between the two three-way switching valves 18 and 19 is closed.

The flow meter 7 is connected to the control board 15, and measures the flow rate of the paint passing through the flow meter 7 and inputs the measured value to the control board 15. The flow rate measured value is displayed on the control panel 15, and the stroke of the pump 11 of each paint supply system 2 is adjusted based on the flow rate measured value so that the paint supplied from each paint supply system 2 is predetermined. It is adjusted to the set flow rate value.

The hardener supply passage 8 includes a primary-side hardener supply passage 8a for supplying the hardener from a hardener container (not shown) to the pressure adjusting valve 20 at a relatively high pressure as in the case of the above-mentioned paint. The secondary side hardener supply passage 8b for supplying the hardener adjusted to a relatively low pressure by the pressure adjusting valve 20 to the static mixer 17 is provided. A pump 21, a pulsation absorbing accumulator 22, a regulator 23 and a flow meter 24 are provided from the upstream side in the secondary side hardener supply passage 8b. Then, the static mixer 17 mixes the coating material as the main component supplied from the color change valve 1 with the curing agent supplied from the secondary side curing agent supply passage 8b, and the mixed coating material is applied to the coating gun 4. It is supposed to be supplied.

Next, a method of using the coating apparatus having the above structure will be described.

In the above coating apparatus, one unit of operation from the start of operation to the end of operation of the coating line, for example, one operation every one night or five days and night continuous operation from Monday to Friday is one operation. The flow rate measurement work is performed as a preparatory process before the coating process is started and the above operation is started.

In the first step of the flow rate measuring work, the three-way switching valves 18 and 19 are switched to the paint supply state, and the color change valve 1 is used to select one of the seven paint supply systems 2, 2, ... Is opened and the paint of the paint supply system 2 is supplied to the coating gun 4 to fill the paint supply passage 5 with the paint. After that, as a second step, the three-way switching valves 18 and 19 are switched to the flow rate measuring state, and the flow rate is measured for each of the seven paint supply systems 2, 2 ,. That is, after switching to the flow rate measuring state to make the bypass passage 6 communicate with each other, first, the paint of the one paint supply system 2 is passed through the bypass passage 6. Then, the initial flow rate of this paint is measured by the flow meter 7, and the flow rate measurement value is measured by the control panel 1.
5, the stroke amount of the pump 10 of the paint supply system 2 is adjusted based on the measured flow rate value until a predetermined flow rate value is reached. As a result, the flow rate measurement of one paint supply system 2 is completed, then the color change valve 1 is switched so that the other paint supply system 2 is opened, and the flow rate measurement of this paint supply system 2 is completed. Do. After performing the flow rate measurement on all of the seven paint supply systems 2, 2, ..., As a third stage, the paint remaining on the bypass passage 6 and the flow meter 7 is washed.

In this cleaning, the on-off valve 14a of the cleaning fluid supply passage 3 is first opened with the three-way switching valves 18 and 19 maintained in the flow rate measuring state, and the thinner from the thinner supply passage 3a is changed to the color change valve 1. Through the bypass passage 6. After the paint in the bypass passage 6 and the flow meter 7 is pushed out by the thinner and discharged from the coating gun 4, the on-off valve 14a is then closed.
The other on-off valve 14b is opened to introduce air from the air supply passage 3b into the bypass passage 6 and the flow meter 7 to discharge the residual thinner. When the cleaning of the bypass passage 6 and the like is completed, the three-way switching valves 18 and 19 are switched to the paint supply state, and the paint supply passage 5
The cleaning is performed in the same manner as the cleaning described above by using a thinner or the like from the cleaning fluid supply passage 3. This completes the flow rate measurement work, which is a preparation process.

In the above-mentioned coating process, for each vehicle body to be coated which is transported through the coating line, the above-mentioned coating material is applied so that the coating material of the color corresponding to the coating color predetermined by the vehicle body is sent to the static mixer 17. Only one corresponding paint supply system 2 is switched to the open state, and the other paint supply systems 2, 2, ... Are closed. As a result, the corresponding paint is sent from the paint supply system 2 in the open state to the static mixer 17 through the paint supply passage 5,
The static mixer 17 mixes the hardener from the hardener supply passage 8 and the mixed paint is sprayed from the coating gun 4 onto the vehicle body. Further, in the paint supply systems 2, 2, ... Which are closed, the paint in the primary-side paint supply passage 2a is returned through the primary-side return passage 2c and circulated, and the paint in the secondary-side paint supply passage 2b is circulated. Is returned through the secondary side return passage 2d and circulates.

When the painting of the vehicle body is completed, the paint supply system 2 for the paint of the color corresponding to the next vehicle body is switched to the open state by the color change valve 1 and the thinner from the cleaning fluid supply passage 3 is supplied with the paint. Supply to passage 5.
The previous paint remaining in the paint supply passage 5, the static mixer 17, the coating gun 4, etc. from the color change valve 1 is washed away by the mixed liquid of the paint of this time and the thinner supplied to the paint supply passage 5. After this cleaning, the cleaning fluid supply passage 3 is closed and the coating is performed only with the current paint. Hereinafter, the conversion of the coating color and the cleaning of the residual paint are repeated according to the vehicle body to be transported.

Before the operation is completed, the paint supply passage 5 is formed by the thinner and air from the cleaning fluid supply passage 3.
Etc. are washed and the operation of the above 1 unit is completed.

In the case of the above coating apparatus, since the flow meter 7 is provided in the bypass passage 6 different from the paint supply passage 5, the switching valves 18 and 19 are switched to the flow rate measuring state only when the flow rate measurement is necessary. It suffices to pass the paint through the bypass passage 6. By switching to the paint supply state during coating and shutting off the bypass passage, the coating color can be compared to the case where a flow meter is interposed in series in the conventional paint supply passage. It is possible to reduce the consumption of paint and thinner, which is the cleaning liquid, by the amount that the residual paint in the flow meter does not have to be washed each time the conversion is performed.

Further, in the case of using the above-mentioned coating apparatus, the thinner consumed for cleaning the inside of the flow meter 7 is only one time at the end of the flow rate measuring work before the operation, and the conversion of the coating color during the operation is performed. Sometimes it is not necessary to clean the flowmeter 7, so
The thinner consumption can be reduced to the necessary minimum amount as compared with the conventional coating device and the method of use in which the flowmeter must be washed every time the coating color is changed. Also, since the paint does not enter the inside of the flowmeter 7 during painting,
It is possible to reduce not only the thinner but also the consumption amount of the paint as compared with the case where the conventional flowmeter is interposed in series in the paint supply passage. Moreover, since the flow rate of the paint supplied from each paint supply system 2 is adjusted to a predetermined flow rate value before the operation, a constant flow rate of the paint can be discharged from the coating gun 4.

The present invention is not limited to the above embodiment, but includes various other modifications. For example, in the above embodiment, the flow rate is adjusted by adjusting the stroke amount of the pump 10 of the paint supply system 2, 2, ... Based on the flow rate measurement value by the flow meter 7, but the present invention is not limited to this. For example, it may be performed by operating or controlling other flow rate adjusting means such as a flow rate adjusting valve or a flow rate control valve.

Further, in the above embodiment, the curing agent supply passage 8
In the above description, the coating apparatus is shown as an example, but the present invention is not limited to this, and the coating apparatus may be configured except for the curing agent supply passage 8.
In this case, the static mixer 17 is also omitted inevitably. Therefore, if the bypass passage 6 provided with the flow meter 7 is provided so as to bypass the paint supply passage 5 between the color change valve 1 and the coating gun 4. Good.

Further, in the above embodiment, the case where the seven paint supply systems 2, 2, ... Are connected to the color change valve 1 has been described, but the number of paint supply systems is not limited to this, and may be two or more, for example. Even if the paint colors are converted by the two paint supply systems, it is possible to reduce the consumption of thinner and paint as in the above embodiment, as compared with the case where the flowmeter is washed every time the paint colors are converted. it can.

[0030]

As described above, according to the coating apparatus of the present invention, the bypass passage is provided separately from the paint supply passage for supplying the paint from the color change valve to the coating gun. Since the flow meter is installed, the flow meter is interposed in series in the conventional paint supply passage by switching the switching valve so that the paint flows only in the paint supply passage during coating and shutting off the bypass passage. As compared with the above case, it is not necessary to wash the residual paint in the flow meter each time the coating color is changed, so that it is possible to reduce the consumption of paint and thinner as a cleaning liquid.

According to the method of use according to the second aspect of the present invention, the flow rate is measured in each paint supply system by switching to the flow rate measurement state before the start of coating and supplying the paint to the bypass passage provided with the flow meter. After the start of coating, the flow is switched to the paint supply state and the bypass passage is shut off. Therefore, the flowmeter can be cleaned only once when the flow rate measurement is completed. Even if it is performed, it is not necessary to clean the above flowmeter, and it is necessary to eliminate the loss of paint and thinner when cleaning the residual paint in the flowmeter every time the coating color is changed, and to reduce the consumption of them. You can

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a coating apparatus according to an embodiment of the present invention.

FIG. 2 is a partial configuration diagram mainly showing a color change valve, a paint supply passage, a bypass passage and the like of the above embodiment.

[Explanation of symbols]

 1 Color Change Valve 2 Paint Supply System 4 Coating Gun 5 Paint Supply Passage 6 Bypass Passage 7 Flow Meter 18, 19 Three Way Switching Valve

Claims (2)

[Claims] 1. A color change valve to which a plurality of paint supply systems corresponding to paints of respective colors are connected, and which selectively switches only one paint supply system to an open state, and each of the paints via the color change valves. A coating gun to which the paint from the supply system is supplied, and a bypass passage branching from a position on the upstream side of the paint supply passage connecting the coating gun and the color change valve and joining at a position on the downstream side of the paint supply passage, The flow meter provided in the bypass passage and the branching portion and the merging portion of the bypass passage are respectively provided, and the paint from the color change valve to the painting gun flows into only one of the paint supply passage and the bypass passage. The coating apparatus is provided with two switching valves that can be switched in synchronization with each other. 2. A color change valve to which a plurality of paint supply systems corresponding to paints of respective colors are connected, and only one paint supply system is selectively switched to an open state, and each of the above-mentioned color change valves through the color change valves. A coating gun to which the coating material is supplied from a coating material supply system, and a bypass passage branching from a position upstream of the coating material supply passage connecting the coating gun and the color change valve and joining at a position downstream of the coating material supply passage. , A flow meter provided in the bypass passage and a branch portion and a merging portion of the bypass passage, respectively, and the paint from the color change valve to the painting gun is applied to only one of the paint supply passage and the bypass passage. A method of using a coating device having two switching valves that can be switched in synchronism with each other so that the coating valve is protected before starting coating. After switching to the flow rate measurement state that flows only through the flow passage, open the color change valve to switch the paint supply system in sequence and measure the flow rate of the paint supplied to each paint supply system with a flow meter. After the measurement of the flow rate of the supply system is completed, the inside of the bypass passage and the inside of the flow meter are cleaned, and then the switching valve is switched to a paint supply state in which the paint flows only in the paint supply passage to start coating, and while the coating is continuing, A method of using a coating apparatus, characterized in that the switching valve is maintained in a paint supply state even if the coating color is changed.