JP2001276716A - Coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus capable of suppressing fluctuations in the temperature and pressure of a paint to enhance coating quality and capable of enhancing the efficiency of coating work, and also provide a coating method using the same. SOLUTION: In the coating apparatus having a main tank 21 housing a paint P, a coating means 100 for coating an object with the paint P and first circulating piping 29 arranged so as to pass the paint P in the main tank 21 through the coating means 100 to house the same again in the main tank 21, a sub-tank 31 housing the paint P, second circulating piping 35 forming a circulating route for housing the paint P of the sub-tank 31 again in the sub-tank 31, the replenishing piping 40 connected to a flow channel changeover means 34 to replenish the main tank 21 with the paint P of the subtank 31 and the flow channel changeover means 34 provided to the second circulating piping 35 and controlling a flow channel to supply the paint P flowing through the second circulating piping 35 to the replenishing piping 40 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method for applying a paint to an object while circulating the paint.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a conventional coating apparatus. The coating apparatus 1 will be described with reference to FIG. 4 has a paint tank 2, a stirrer 3, a pump 4, a heater 5, an accumulator 6, a regulator 7, a coating gun 8, and the like. The paint tank 2 contains a paint to be applied to an object. Here, the paint is, for example, a mixture of ceramics, protein resin, and other fillers (aggregate), and is adjusted to an appropriate concentration by a solvent.

A stirrer 3 is attached to the paint tank 2, and the stirrer 3 includes, for example, a motor 3a and fins 3b. Then, the fins 3 are driven by the motor 3a.
When b rotates, the paint P in the paint tank 2 is stirred. This is to prevent the filler mixed with the paint P from settling at the bottom of the paint tank 2.
The pump 4 has a function of storing and circulating the paint P from the paint tank 2 to the paint tank 2 again through the circulation pipe 9.

[0004] The heater 5 heats the paint P circulating in the circulation pipe 9 to a constant temperature, and has a temperature detection sensor 5a. For example, an operator grasps the temperature of the paint P in the circulation pipe 9 by using the temperature detection sensor 5a and adjusts the temperature of the heater 5. The accumulator 6 smoothes the pressure of the paint P in the circulation pipe 9, and the regulator 7 adjusts the pressure of the paint P in the circulation pipe 9. The coating gun 8 discharges and applies the coating material P supplied through the circulation pipe 9 to an object.

Next, an example of the operation of the conventional coating apparatus 1 will be described with reference to FIG. First, the paint P is supplied from the paint tank 2 to the paint gun 8 through the circulation pipe 9 by the operation of the pump 4. At this time, the temperature of the paint P is adjusted by the heater 5, and the pressure in the circulation pipe 9 is adjusted by the accumulator 6 and the regulator 7. And paint P
Is discharged toward the nozzle 8a of the coating gun 8 to apply the coating material P to the object. On the other hand, the paint P not discharged by the paint gun 8 is sent again from the circulation pipe 9 into the paint tank 2.

As described above, the paint P contained in the paint tank 2 circulates between the paint tank 2 and the coating gun 8 through the circulation pipe 9. Thus, when the paint P is a solvent mixed with a filler (aggregate), the filler does not precipitate or clog in the circulation pipe 9. Therefore, a change in the pressure in the circulation pipe 9 can be prevented, and the amount of application to the object by the coating gun 8 can be made uniform.

[0007]

In the coating apparatus 1 shown in FIG. 4, after the paint P is heated to a predetermined temperature by the heater 5, it is discharged by the coating gun 8. By setting the temperature of the paint P to a predetermined temperature as described above, the viscosity of the paint P is adjusted to stabilize the application of the paint P by the coating gun 8. In addition, the paint P which has reached a certain temperature by the heater 5
Are circulated and accommodated in the paint tank 2, so that the paint P in the paint tank 2 is also heated to a predetermined temperature.

On the other hand, when the paint P stored in the paint tank 2 runs out, it is necessary to replenish the paint tank 2 with new paint P. Here, if new paint P is supplied to the paint tank 2, the paint temperature in the paint tank 2 will decrease.
This change in the paint temperature causes the viscosity of the paint P to change and the paint ejection from the paint gun 8 to become unstable, resulting in a decrease in paint quality. Therefore, when a new paint P is replenished, the painting operation must be suspended for a long time until the paint P is stabilized at a predetermined temperature, which causes a problem that the work efficiency is reduced.

The paint P in the paint tank 2 is supplied to the stirrer 3.
However, when the amount of the paint P in the paint tank 2 decreases, bubbles are generated by the agitation. If these bubbles enter the circulation pipe 9, the paint pressure will fluctuate. Due to this pressure fluctuation, the discharge of the paint from the coating gun 8 becomes unstable, and the paint quality is reduced. Therefore, in order to prevent the generation of air bubbles by maintaining the paint P in the paint tank 2 at a certain amount or more, there is a problem that the paint work must be frequently interrupted to supply the paint P.

In particular, in recent years, the thickness of the paint P to be applied to an object has been required to be thinner.
In some cases, the thickness needs to be set to 0 μm ± 2 μm. At this time, the pressure fluctuation and the temperature fluctuation of the paint P in the circulation pipe are sensitive to the film thickness fluctuation of the paint. Therefore, in order to obtain a high-precision and high-quality paint film thickness, the pressure fluctuation and the temperature fluctuation are suppressed as much as possible. There is a need.

Accordingly, the present invention solves the above-mentioned problems, and provides a coating apparatus and a coating method capable of suppressing a temperature fluctuation and a pressure fluctuation of a coating material to improve the quality of the coating and improving the efficiency of the coating operation. It is intended to be.

[0012]

According to a first aspect of the present invention, there is provided a main tank containing a paint, a coating means for discharging the paint, and the paint circulating between the main tank and the coating means. In the coating apparatus having the first circulation pipe arranged as described above, a sub-tank for storing the paint, a second circulation pipe for storing the paint in the sub-tank again in the sub-tank, and connected to the main tank And a flow switching means provided in the second circulation pipe and supplying the paint flowing in the second circulation pipe to the supply pipe side.

According to a second aspect of the present invention, in the configuration of the first aspect, there is provided a coating apparatus in which a filler is mixed with the paint.

According to the first or second aspect, the paint in the main tank is circulated from the first circulation pipe through the coating means so as to be again stored in the main tank. On the other hand, the paint contained in the sub tank is circulated in the second circulation pipe so as to be contained again in the sub tank. In this state, the paint in the main tank is applied to the object from the painting means through the first circulation pipe. Then, since the paint in the main tank decreases, it is necessary to supply the paint to the main tank. At this time, the passage switching means is operated, and the paint circulating in the second circulation pipe is supplied to the supply pipe side to be supplied to the main tank.

[0015] This eliminates the need to interrupt the painting operation to replenish the paint, thereby improving work efficiency. Further, since it is possible to prevent the temperature fluctuation and the pressure fluctuation of the paint which occur before and after the replenishment operation as in the related art, the paint discharged from the coating means can be stabilized. Therefore, the coating quality of the object can be improved. Further, when the filler is mixed with the paint, the paint in the main tank and the sub tank is circulated respectively, thereby preventing the first circulation pipe and the second circulation pipe from being clogged.

[0016] The invention of claim 3 is claim 1 or claim 2.
In any of the above structures, the coating apparatus is characterized in that the main tank is provided with a remaining amount detection unit that detects the remaining amount of the stored paint.

According to the third aspect of the present invention, the main tank is provided with the remaining amount detecting section, and the remaining amount detecting section detects the remaining amount of the paint in the main tank. Thus, the remaining amount of the paint stored in the main tank can be always grasped, and the supply of the paint from the sub tank to the main tank can be performed at an appropriate amount and timing. Thereby, the temperature control of the paint in the main tank and the pressure control in the first circulation pipe can be easily performed.

According to a fourth aspect of the present invention, in the configuration of the third aspect, the remaining amount detection unit has a function of sending the detected remaining amount of paint to a control unit, and the control unit determines the remaining amount of paint. A coating apparatus having a function of operating the flow path switching means on the basis of the above.

According to the fourth aspect of the present invention, the remaining amount of paint detected by the remaining amount detection unit is sent to the control unit, and the control unit operates the flow path switching means based on the remaining amount of paint to operate the main unit. Supply paint to the tank. Thereby, the replenishment of the paint from the sub tank to the main tank is automatically performed, so that the replenishment work of the paint can be improved.

According to a fifth aspect of the present invention, in the configuration of the fourth aspect, when the paint remaining amount reaches the lower limit remaining amount threshold value, the control section operates the flow path switching means to move the paint supply side to the supply pipe side. The coating apparatus is characterized in that the paint is supplied, and when the paint remaining amount reaches the upper limit remaining amount threshold, the flow passage switching means is operated to control the paint to circulate through the second circulation pipe.

According to the fifth aspect of the present invention, the lower limit threshold value and the upper limit threshold value of the paint remaining amount are set in the control unit in advance. , The paint is replenished from the sub tank to the main tank, and when the upper limit remaining amount threshold is reached, the replenishment of the paint from the sub tank to the main tank is stopped. Therefore, the main tank is replenished by the amount from the lower limit remaining threshold to the upper limit remaining threshold. Thereby, the temperature fluctuation of the paint in the main tank can be minimized, the discharge of the paint from the painting means can be stabilized, and the painting quality on the object can be improved.

When a filler is mixed with the paint, the paint in the main tank may be stirred by a stirrer in order to prevent the filler from settling at the bottom of the main tank. At this time, when the remaining amount of the paint in the main tank becomes small, bubbles are generated in the paint by stirring. Here, if the lower limit threshold value is set so that no bubbles are generated, the pressure fluctuation is suppressed by preventing the generation of bubbles in the paint, and the stability of the paint discharged from the coating means is secured. can do.

According to a sixth aspect of the present invention, the paint contained in the main tank is circulated using the first circulation pipe between the main tank and a coating means for applying the paint to the subject using the first circulation pipe. In the coating method for applying, the paint contained in the sub-tank is circulated again using the second circulation pipe so as to be contained in the sub-tank, and the remaining amount of the paint in the main tank is detected. When the remaining amount is equal to or less than the threshold, the coating method is characterized in that the paint contained in the sub tank is supplied to the main tank from the second circulation pipe through a supply pipe.

The invention according to claim 7 is characterized in that, in the constitution according to claim 6, a coating method in which a filler is mixed in the coating material.

According to the configuration of claim 6 or 7, the paint contained in the main tank is circulated between the paint means and the first circulation pipe. On the other hand, the paint contained in the sub tank is also circulated from the second circulation pipe so as to be contained again in the sub tank. In this state, when the paint is applied from the painting means, the paint in the main tank decreases. Therefore, when the remaining amount of paint in the main tank becomes equal to or less than the lower limit threshold value, the paint in the second circulation pipe is supplied to the main tank.

Thus, the painting operation is not interrupted when the paint is replenished, so that the work efficiency can be improved. Further, since it is possible to prevent the temperature fluctuation and the pressure fluctuation of the paint before and after the replenishment work as in the related art, the paint discharged from the painting means can be stabilized. Therefore, the coating quality of the object can be improved. Further, when the filler is mixed with the paint, the paint in the sub tank is circulated in the second circulation pipe, so that it is possible to prevent the paint from clogging the first circulation pipe and the second circulation pipe. it can.

The invention of claim 8 is the invention of claim 6 or claim 7.
In any one of the above structures, the supply of the paint to the main tank is stopped when the upper limit remaining amount threshold is reached.

According to the eighth aspect of the invention, the supply of the paint to the main tank is started when the paint remaining amount is equal to or smaller than the lower limit threshold value, and is stopped when the paint remaining amount is equal to or larger than the upper limit threshold value. Therefore, the main tank is replenished by the amount from the lower limit remaining threshold to the upper limit remaining threshold. Thereby, the temperature fluctuation of the paint in the main tank can be minimized, the discharge of the paint from the painting means can be stabilized, and the painting quality on the object can be improved.

[0029]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing a preferred embodiment of a coating apparatus according to the present invention. A coating apparatus 10 will be described with reference to FIG. The coating apparatus 10 in FIG. 1 can be roughly divided into a main tank system 20 and a sub tank system 30. The main tank system 20 and the sub tank system 30 are connected by a supply pipe 40. The main tank system 20 includes a main tank 21, a stirrer 22, a pump 23, a heater 24, an accumulator 2
5. Regulator 26, coating gun 100 as a coating means
Etc. The paint tank 21 stores a paint P to be applied to an object. The paint P is a paint adjusted to an appropriate concentration by a solvent, for example, and is mixed with a filler (aggregate) composed of ceramics such as alumina and zirconia, calcium carbonate and other inorganic compounds, and organic compounds such as protein resins. It was done.

A stirrer 22 is attached to the main tank 21. The stirrer 22 prevents the filler contained in the paint P contained in the paint tank 21 from settling at the bottom of the paint tank 21 and includes, for example, a motor 22a and fins 22b. And fin 2
The inside of the paint tank 21 is agitated by the rotation of the motor 2b by the operation of the motor 22a.

Further, a first circulation pipe 29 is connected to the main tank 21. The first circulation pipe 29 supplies the paint P from the main tank 21 to the coating gun 100 and sends the paint P to the coating gun 100. A circulation path is formed such that the paint P is stored in the main tank 21 again. The pump 23 is a power for circulating the paint P stored in the paint tank 21 through the first circulation pipe 29.

Further, a remaining amount detecting section 27 is disposed in the main tank 21, and the remaining amount detecting section 27 has a function of detecting a remaining paint amount Pr 1 of the paint P stored in the main tank 21. . As the remaining amount detecting unit 27, for example, a unit that detects the remaining amount of paint Pr1 by applying ultrasonic waves to the liquid surface of the paint P, a unit that reads the display of the weight scale attached to the main tank 21 with an optical sensor, and the like. Used. Further, the remaining amount detection unit 27 has a function of transmitting the detected paint remaining amount Pr1 to the control unit 200.

The heater 24 heats the circulating paint P to a constant temperature, and has a temperature sensor 2 on its output side.
4a is attached. An operator can adjust the temperature of the heater 24 based on the temperature sensor 24a, for example. The accumulator 25 includes a first circulation pipe 29
To smooth the internal pressure. That is, since the paint P is circulated in the first circulation pipe 29 by the pump 23, the paint pressure in the first circulation pipe 29 is in a state of being pulsated by the pump 23. Accumulator 25
Is to smooth the pressure of the pulsating paint P.
The regulator 26 adjusts the pressure of the paint P in the first circulation pipe 29.

The coating gun 100 discharges the coating material P sent from the first circulation pipe 29 and applies the coating material to the object. Here, in order to spray the filler-containing paint P, the spray gun 100 is, for example, a two-fluid spray gun provided with a gas outlet for controlling the spray range and spray shape. And painting gun 100
The paint P that is not discharged from the main tank 21 is again stored in the main tank 21 through the first circulation pipe 29.

As described above, the paint P in the paint tank 21 passes through the first circulation pipe 29 by the pump 23,
4 heats to a predetermined temperature. After that, paint P
The pressure is adjusted to a predetermined pressure by the accumulator 25 and the regulator 26 and sent to the coating gun 100. Then, the paint P is discharged onto the object by the paint gun 100 or circulates through the first circulation pipe 29 into the paint tank 21. As described above, by performing the coating with the coating gun 100 while the paint P is circulating, even if the filler is mixed in the paint P, the first circulation pipe 29 is not clogged, and the stable paint can be performed. it can.

Next, the sub-tank system 30 will be described with reference to FIG. The sub-tank system 30 in FIG. 1 includes a sub-tank 31, a stirrer 32, a pump 33, a three-way valve 34 as a flow path switching unit, and the like. The sub tank 31 stores the same paint P as the paint P stored in the paint tank 21. The sub tank 31 has a stirrer 32.
Is attached. The stirrer 32 stirs the paint P in the sub tank 31 by rotating the fins 32b by the motor 32a. Thereby, when the filler is mixed in the paint P, the filler can be prevented from settling at the bottom of the sub tank 31.

Further, the remaining amount detecting unit 3
6 is disposed, and the remaining amount detection unit 36
Has a function of detecting the remaining amount Pr2 of the sub-paint in the paint P stored in the sub-paint P. As the remaining amount detecting unit 36, for example, a unit that applies ultrasonic waves to the liquid surface of the coating material P to detect the remaining amount of sub coating material Pr2, a unit that reads the display of the weighing scale attached to the sub tank 31 with an optical sensor, and the like. Used.
Further, the remaining amount detection unit 36 has a function of sending the detected remaining amount of sub paint Pr2 to the control unit 200.

The pump 33 circulates the paint P from the sub tank 31 to the second circulation pipe 35 through the three-way valve 34 to the sub tank 31 again. The three-way valve 34 is provided in the second circulation pipe 35 and is connected to one side 40 a of the supply pipe 40. The three-way valve 34 switches the paint P circulating in the second circulation pipe 35 to flow to the supply pipe 40. The other side 40b of the supply pipe 40
Is connected to the main tank 21, and supplies the paint P flowing through the second circulation pipe 35 through the supply pipe 40 to the main tank 2.
1 can be sent. The operation of the three-way valve 34 is controlled by the control unit 200.

Here, in the sub tank system 30, the paint P in the sub tank 31 is circulated in the second circulation pipe 35 by the pump 33. Then, the paint P is circulated in the second circulation pipe 35 by the three-way valve 34 or is supplied to the main tank 21 through the supply pipe 40. In this way, by circulating the paint P in the sub tank 31, it is possible to prevent the filler contained in the paint P from causing clogging in the second circulation pipe 35.

Here, the control section 200 has a function of controlling the operation of the three-way valve 34 based on the paint remaining amount Pr1 sent from the remaining amount detection section 27. Specifically, upper limit remaining amount threshold value Pmax and lower limit remaining amount threshold value Pmin are set in control unit 200 in advance. When the paint remaining amount Pr1 in the main tank 21 becomes equal to or less than the lower limit remaining threshold value Pmin (Pr1 ≦ Pmin), the three-way valve 34 is operated to supply the paint P to the main tank 21. And
The paint P in the main tank 21 is at the upper limit remaining amount threshold Pmax.
When it becomes the above (Pr1 ≧ Pmax), the three-way valve 34 is operated to stop the supply of the paint P to the main tank 21. Further, when the sub paint remaining amount Pr2 sent from the remaining amount detection unit 36 decreases to a predetermined value, the control unit 200 can output, for example, a signal to replenish the sub tank 31 with the paint P to the operator.

FIG. 2 is a flowchart showing a preferred embodiment of the coating method of the present invention. The coating method will be described with reference to FIGS. First, in ST1 of FIG. 2, the coating by the coating apparatus 10 of FIG. 1 is started, and the paint P in the main tank 21 circulates in the first circulation pipe by the operation of the pump 23. The paint P, which has reached the predetermined paint temperature by the heater 24, is pressure-adjusted by the accumulator 25 and the regulator 26, and
Sent to 0. Then, the paint P is discharged by the nozzle 101 of the coating gun 100 and the paint P is applied to the target object.

On the other hand, in the sub-tank system 30, the pump 33 is operated, and the paint P in the sub-tank 31 circulates in the second circulation pipe 35. At this time, the three-way valve 34 controls the control unit 20 so that the paint P circulates in the second circulation pipe 35.
It is controlled by 0. Further, while the coating by the coating gun 100 is being performed, the paint remaining amount Pr1 of the main tank 21 detected by the remaining amount detecting unit 27 is stored in the control unit 20.
Monitored by 0.

Then, in ST2, the remaining amount detecting section 27
When the paint remaining amount Pr1 detected by the above becomes equal to or less than the lower limit remaining amount threshold value Pmin (Pr1 ≦ Pmin), ST
In 3, the three-way valve 34 is operated by the control unit 200 so that the paint P circulating in the sub-tank system 30 is supplied to the main tank 21 through the supply pipe 40. That is, the paint P stored in the sub tank 31 is supplied to the main tank 21.

Thereafter, the paint remaining amount Pr in the main tank 21
1 is equal to or greater than the upper limit remaining amount threshold value Pmax (Pr1 ≧
In Pmax) and ST5, the control unit 200 operates the three-way valve 34 so that the paint P circulates in the second circulation pipe 35, and stops the supply of the paint P to the main tank 21. Then, the paint remaining amount Pr in the main tank 21
When 1 falls below the lower limit threshold value Pmin, the paint P is supplied from the sub tank 31 to the main tank 31 again (ST2 to ST5). Further, when the remaining amount Pr2 of the sub-paint in the sub-tank 31 decreases, the control unit 200 outputs a signal to the outside, for example, to urge the worker to supply the paint P to the sub-tank 31.

As described above, the paint P in the main tank 21
Is the amount from the lower limit threshold value Pmin to the upper limit threshold value Pmax, so that the temperature of the paint P in the main tank 21 does not change rapidly. Therefore,
By minimizing the temperature change of the paint P when refilling the paint P into the main tank 21, the main tank 2
1 can be replenished without stopping the painting operation, and continuous painting on the object can be performed, thereby dramatically improving the productivity. Further, since the change in the paint temperature when the paint P is supplied to the main tank 21 can be minimized, the paint P discharged from the coating gun 100 can stably achieve high quality paint. .

Also, the paint remaining amount Pr1 in the main tank 21
Is lower than the lower threshold Pmin.
Is supplied, the remaining paint amount Pr in the main tank 21
It is possible to prevent bubbles from being generated due to the decrease of 1. That is, when the paint remaining amount Pr1 decreases, bubbles are generated by the fins 22b of the stirrer 22, but by setting the lower limit remaining amount threshold Pmin such that bubbles do not occur, the inside of the main tank 21 is always constant. This means that more paint P is present. Therefore, the generation of air bubbles can be prevented, the pressure in the first circulation pipe 17 can be kept constant, the paint P discharged from the coating gun 100 can be stabilized, and the paint P with a uniform film thickness can be formed on the object. Can be applied.

FIG. 3 is a graph showing a change in paint pressure, a change in paint temperature, and a change in paint film thickness with respect to time when coating is performed using the coating apparatus 10 in FIG. 1 and the coating apparatus 1 in FIG. 4, respectively. This will be specifically described with reference to FIG. In addition,
In FIG. 3, the capacity of the main tanks 2 and 21 is 15 liters, the paint pressure setting of the circulation pipes 9 and 29 is 79 KPa,
The temperature of the paint P was set at 31.5 ° C.

FIG. 3A is a graph showing the state of the change in the paint pressure. In FIG.
It can be seen that pressure fluctuation occurs at time t1 when is used. This is because bubbles were generated by the stirrer 3 in the paint tank 2 and entered into the pipe 9. At this time, the paint remaining amount Pr1 in the paint tank 2 was 4 liters.

Thereafter, as shown in FIG.
At 2 the painting work was stopped and 26.4 was added to paint tank 2.
° C paint P was supplied to the main tank 2. Then, after a lapse of about 30 minutes, the temperature of the coating material rose to 32.1 ° C., and the coating operation was restarted from time t3. The time from time t2 to time t3 was about 45 minutes. At this time, FIG.
As shown in (C), the film thickness of the paint applied to the object fluctuated by about 4.2 μm due to the pressure fluctuation and the temperature fluctuation before and after the supply of the paint P.

As described above, in the conventional coating apparatus 1 shown in FIG. 4, when the paint P is replenished, the work must be interrupted until the paint temperature reaches a constant temperature, resulting in a decrease in work efficiency. Further, pressure fluctuations and temperature fluctuations before and after the supply of the paint P cause variations in the coating film thickness, and high-quality coating cannot be performed.

On the other hand, in the coating apparatus 10 shown in FIG. 1, when the lower limit threshold value Pmin is set to 9.7 liters and the upper limit threshold value Pmax is set to 10.7 liters, FIG.
As shown in (A) and FIG. 3 (B), pressure fluctuation and temperature fluctuation due to the paint P were not observed. For this reason, FIG.
As shown in (C), the coating film thickness on the object was stable, and the variation was 1.9 μm, which enabled extremely stable coating.

As described above, in the coating apparatus 10 shown in FIG. 1, the coating operation is not interrupted, so that the coating operation can be performed efficiently. In addition, since there is no change in temperature and pressure before and after the replenishment of the paint P as in the related art, a stable painting operation can be performed, and the quality of the paint can be improved.

According to the above embodiment, the main tank 2
In a state where the paint P in the first and sub tanks 31 is circulated, the paint P circulating in the second circulation pipe 35 is supplied to the supply pipe 40 by the operation of the three-way valve 34 and supplied to the main tank 21. For this reason, it is possible to prevent the interruption of the painting operation to replenish the paint P, thereby improving the working efficiency, and prevent the temperature fluctuation and the pressure fluctuation, thereby improving the coating quality of the object. Furthermore, when a filler is mixed in the paint P, the paint in the main tank 21 and the sub tank 31 is circulated,
It is possible to prevent the first circulation pipe 29 and the second circulation pipe 35 from being clogged.

Further, the remaining amount detecting section 27 is provided in the main tank 21.
Is provided, the remaining amount of paint Pr1 stored in the main tank 21 can always be grasped, and the supply of the paint P from the sub tank 31 to the main tank 21 can be performed with an appropriate amount and timing. Become. Therefore, the temperature control of the paint P in the main tank 21 and the pressure control in the first circulation pipe 29 can be easily performed.

Further, based on the remaining paint amount Pr1 detected by the remaining amount detection unit 27, the control unit 200 operates the three-way pump to supply the paint P to the main tank 21. The supply of the paint P to the paint P is automatically performed, and the work of supplying the paint P can be improved.

Further, a lower limit remaining amount threshold value Pmin and an upper limit remaining amount threshold value Pmax are set in advance in the control unit 200. When the paint remaining amount Pr1 reaches the lower limit remaining amount threshold value Pmin, the sub tank 31 is moved to the main tank 21. When the paint is replenished and the upper limit remaining amount threshold value Pmax is reached, the supply of the paint P from the sub tank 31 to the main tank 21 is stopped, so that the temperature fluctuation of the paint P in the main tank 21 is minimized, and the paint gun The ejection of the coating material P from 100 can be stabilized, and the coating quality on the target object can be improved.

The embodiment of the present invention is not limited to the above embodiment. For example, although the case where the filler is mixed in the paint P is mentioned, the coating apparatus 10 in FIG. 1 and the coating method in FIG. 2 can be used for the paint in which the filler is not mixed. Further, as the coating means 100 in FIG. 1, a coating gun that discharges the paint P is illustrated, but various coating means such as a dispenser or a roller may be used.

[0058]

As described above, according to the present invention,
It is possible to provide a coating apparatus and a coating method capable of suppressing the temperature fluctuation and the pressure fluctuation of the coating material to improve the quality of the coating and improving the efficiency of the coating operation.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a preferred embodiment of a coating apparatus of the present invention.

FIG. 2 is a flowchart showing an embodiment of the coating method of the present invention.

FIG. 3 is a graph showing changes in paint pressure, paint temperature, and paint film thickness in the paint apparatus of the present invention in FIG. 1 and the conventional paint apparatus in FIG. 4;

FIG. 4 is a configuration diagram showing an example of a conventional coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Coating apparatus 20 ... Main tank system 21 ... Main tank 23 ... Pump 24 ... Heater 28 ... 1st circulation pipe 29 ... Remaining amount detection part 30 ... Sub tank System 31 ... Sub-tank 33 ... Pump 34 ... Three-way valve (flow path switching means) 35 ... Second circulation pipe 36 ... Remaining amount detection unit 100 ... Coating gun 200 ... Control Part P: Paint Pmax: Upper threshold Pmin: Lower threshold Pr1: Paint remaining

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D073 AA01 BB03 CA01 CA02 CA06 DC06 DC07 DC22 4D075 AA01 AA72 AA85 CA48 EA05 EC13 4F042 AA01 BA09 BA12 CA01 CA06 CB02 CB08 CB11 CB20 CB26 CC07 CC14 CC30

Claims (8)

[Claims] 1. A main tank containing a coating material, a coating means for discharging the coating material, and a first circulation pipe arranged so as to circulate the coating material between the main tank and the coating means. In the coating apparatus, a sub-tank for storing the paint, a second circulation pipe for storing the paint in the sub-tank again in the sub-tank, a supply pipe connected to the main tank, and a second circulation pipe A coating device provided with a flow path switching means for supplying the paint flowing in the second circulation pipe to the supply pipe side. 2. The coating apparatus according to claim 1, wherein a filler is mixed in the paint. 3. The coating according to claim 1, wherein the main tank is provided with a remaining amount detecting unit that detects a remaining amount of the stored paint. apparatus. 4. The remaining amount detecting section has a function of sending the detected remaining amount of paint to a control section, and the control section has a function of operating the flow path switching means based on the remaining amount of paint. The coating apparatus according to claim 3, comprising: 5. The control section operates the flow path switching means to supply the paint to the supply pipe side when the paint remaining amount reaches the lower limit remaining amount threshold, and the paint remaining amount becomes the upper limit remaining amount. 5. The coating apparatus according to claim 4, wherein when the amount reaches a threshold value, the flow path switching unit is operated to control the paint to circulate through the second circulation pipe. 6. 6. A coating method for applying the paint to an object while circulating the paint contained in a main tank between the main tank and an application means for applying the paint to the object using a first circulation pipe. Circulating the paint contained in the sub-tank again using the second circulation pipe so as to be contained in the sub-tank, detecting a remaining amount of the paint in the main tank, and detecting a remaining amount of the paint in a lower limit threshold. When the value is equal to or less than the value, the paint stored in the sub tank is supplied to the main tank from the second circulation pipe through a supply pipe. 7. The coating method according to claim 6, wherein a filler is mixed in the paint. 8. The coating method according to claim 6, wherein the supply of the paint to the main tank is stopped when an upper limit remaining amount threshold is reached.