JPS6153108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a coating device for spraying paint.
The present invention relates to a device for converting the solvent used in paint to be supplied to a sprayer.

In general, the quality of the coating depends on the coating environment temperature inside the coating booth, so in each season when the coating environment temperature changes significantly, a so-called external solvent is added to the coating to create a solvent with an evaporation rate suitable for that season. is being exchanged. However, in the morning, afternoon,
Conventionally, the same solvent is used throughout the day due to the complexity of replacing the solvent, even though the temperature of the painting environment changes at night. Therefore, the quality of the coating is not constant, and coating defects such as orange skin and sagging may occur.

In order to eliminate such coating defects, it is possible to control the temperature inside the coating booth at a constant level.
However, since the air inside the painting booth contains gas from volatilized solvents, it is difficult to reuse the air inside the painting booth to maintain the health of workers and prevent fires. Installing a temperature control device to maintain a constant temperature of the large amount of fresh air flowing into the system requires enormous operating and equipment costs.

SUMMARY OF THE INVENTION In view of the conventional situation as described above, an object of the present invention is to provide a solvent conversion device for a coating apparatus that can automatically convert a solvent without requiring complicated operations.

The present invention connects a plurality of solvent passages supplying different types of solvents to a paint passage supplied to a sprayer, and operates a valve provided in each solvent passage to convert the solvent added to the paint. This is what I did.

First Invention The present invention provides a coating apparatus in which a paint supply device 6 is connected to a sprayer 1 via paint passages 7 and 13, as illustrated in the principle diagram of an embodiment in FIG. A plurality of solvent supply devices 1
6, 21, 26 are connected to the paint passage 7 via solvent passages 17, 22, 27 provided with valves 19, 24, 29, respectively, and a stirring device 10 is provided in the paint passage 13 at a position downstream of this connection. This is a solvent conversion device characterized by being provided with a solvent conversion device 33 that sequentially opens the valves 19, 24, and 29 of the solvent passage according to a preset time.

In this solvent conversion device, if the time to open the valve of each solvent passage is set in the solvent conversion control device based on the predicted temperature change for that day, the type of solvent suitable for the temperature at that time is supplied at each time of the day. It can be added to the paint that is fed to the sprayer. Therefore, the solvent can be automatically converted to one suitable for the coating environment temperature at the time without the need for complicated operations, so that high-quality coating can be performed efficiently.

Next, an embodiment of the first invention will be described with reference to FIGS. 1 to 3.

As shown in FIG. 2, the apparatus of this example uses an air atomizing paint gun 1 as an atomizer, and a solvent supply device with three types of thinners, first, second, and Third solvent supply device 16, 21, 2
As shown in FIG. 3, the solvent conversion control device has three first and second agitators. , a solvent conversion control device that sequentially operates the third electromagnetic switching valves 35, 36, and 37 for the time set in each timer by three first, second, and third timers _T1 , _T2 , and _T3 . 33 is used. As shown in FIG. 2, the paint supply device 6 is connected to the first
It is connected to the tank 12 of the stirring device through the paint passage 7, and the tank 12 is connected to the pump 14 and the flow rate regulating valve 1.
The first, second, and third solvent supply devices 16, 21, and 26 are connected to the paint supply path 2 of the coating gun through a second paint passage 13 provided with a flow rate regulating valve 1.
8, 23, 28 and control valves 19, 24, 29
and a first provided with operating on-off valves 20, 25, 30;
It is connected to the tank 12 of the stirring device via second and third solvent passages 17, 22, 27. Also, the first
An air supply path 4 for operating a needle valve 3 provided with a high-pressure air supply device 31 in the paint supply path 2 of the painting gun and the air supply path 5 for atomization and pattern adjustment.
and connected to the pneumatically operated on-off valve 9 of the first paint passage and the pneumatically operated on-off valves 20, 25, 30 of the first, second and third solvent passages, respectively. 2. A high-pressure air supply device 32 is connected to the air supply path 5 for atomization and pattern adjustment of the coating gun. Furthermore, as shown in Figures 3 and 2, the third
The high-pressure air supply device 34 is connected to the pneumatically operated control valve 19 of the first solvent passage through the first electromagnetic switching valve 35 and to the pneumatically operated control valve 19 of the second solvent passage via the second electromagnetic valve 36. The control on-off valve 24 is connected to the pneumatically operated control on-off valve 29 of the third solvent passage via a third electromagnetic switching valve 37. In Figure 3, SS is the power supply, SW is the switch, and _t11 and _t12 are the first
Normally closed and normally open contacts of timer T ₁ , t ₂₁ and t ₂₂ are the second
Normally closed and normally open contacts of timer T ₂ , t ₃ is the third timer
T ₃ normally closed contact.

When using the apparatus of this example, the paint supply device 6 and the first, second, and third solvent supply devices 16, 21, 26
and driving the first high-pressure air supply device 31 and the third high-pressure air supply device 34, respectively.
At the same time as opening the on-off valve V of the first high-pressure air supply device 31, the switch SW is closed. Additionally, the stirring device 10 is driven. Then, by opening the on-off valve V, high-pressure air for operating the needle valve 3 is supplied to the coating gun 1, and at the same time, the on-off valve 9 of the first paint passage and the first, second, and third solvent passages are activated. The on-off valves 20, 25, and 30 are opened, and paint is supplied into the tank 12 of the stirring device. In addition, when the switch SW is closed, the first timer T ₁ is excited, the first electromagnetic switching valve 35 is switched, the control opening/closing valve 19 of the first solvent passage is opened, and the first solvent is stirred. It is fed into the tank 12 of the device. When a predetermined amount of the paint and the first solvent have flowed into the tank 12 at a desired ratio, the first high-pressure air supply device 31
Close the on-off valve V.

When painting, the pump 14 in the second paint passage is driven to drive the second high-pressure air supply device 32, and the on-off valve V of the first high-pressure air supply device 31 is opened.
Then, by driving the second high-pressure air supply device 32, high-pressure air is supplied to the air supply passage 5 for atomization and pattern adjustment of the coating gun, and by opening the above-mentioned on-off valve V, the on-off valve for the first paint passage is opened. 9 and 1st, 2nd,
Opening/closing valves 20, 25, 30 for operating the third solvent passage
are opened, and high pressure air is supplied to the air supply 4 for operating the needle valve of the painting gun.
Needle valve 3 that was closing the paint supply path 2 of the paint gun and the air supply path 5 for atomization and pattern adjustment
is opened, while the first in the tank 12 of the stirring device
The paint to which the solvent has been added and stirred is supplied to the paint supply path 2 of the paint gun by driving the pump 14. Therefore, paint is ejected from the paint gun 1, the paint is atomized by high-pressure atomizing air, the pattern is adjusted by high-pressure pattern-adjusting air, and evaporation is performed to suit the painting environment temperature at that time. The coating is done with a paint to which a speed thinner or first solvent is added. When the set time of the first timer T ₁ has elapsed since the first timer T 1 was energized, in other words, when the coating environment temperature becomes unsuitable for the first solvent, the normally closed contact t _{11 of the first timer opens and the normally closed contact t 11} of the first timer opens. The open contact t ₁₂ closes and the normally closed contact t ₁₁ opens to restore the first solenoid switching valve 35, while the normally open contact
When _t12 is closed, the second timer _T2 is energized and the second electromagnetic switching valve 36 is operated, and when the first electromagnetic switching valve 35 is restored, the control opening/closing valve 19 for the first solvent passage is closed. , the control on-off valve 24 for the second solvent passage is switched by the switching operation of the second electromagnetic switching valve 36.
is opened, and instead of stopping the supply of the first solvent to the tank 12, the second solvent is supplied to the tank 12, and the paint to which the second solvent has been added and stirred is supplied to the paint gun 1 and sprayed. The coating is then coated with a paint to which a thinner, ie, a second solvent, is added with an evaporation rate suitable for the coating environment temperature at that time. Further, when the set time of the second timer T ₂ has elapsed after the second timer T 2 is energized, so to speak, when the coating environment temperature becomes unsuitable for the second solvent, the normally closed contacts t ₂₁ and t ₂₂ of the second timer is switched and the second electromagnetic switching valve 36 is restored, while the third timer _T3 is excited and the third electromagnetic switching valve 37 is switched,
While the control on-off valve 24 of the second solvent passage is closed, the control on-off valve 29 of the third solvent passage is opened, and instead of stopping the supply of the second solvent to the tank 12, the third solvent is The paint is supplied to the tank 12 and added with a thinner, ie, a third solvent, having an evaporation rate suitable for the coating environment temperature at that time, and is supplied to the coating gun 1 and sprayed. Furthermore, when the set time of the third timer T ₃ has elapsed since it was energized, in other words, when the coating environment temperature becomes unsuitable for the third solvent, the normally closed contact t ₃ of the third timer opens; The third electromagnetic switching valve 37 is restored, the control valve 29 for the third solvent passage is closed, and the third solvent is no longer supplied to the tank 12. Note that by the time the supply of the third solvent is stopped, the painting work for that day has been completed.

In the apparatus of this example, the change in the coating environment temperature on that day is predicted, and based on the prediction, the first, second, and
By setting the time for using the third solvent in the first, second, and third timers, it is possible to use the first, second, or third solvent suitable for the coating environment temperature at each time.

Second Invention The present invention provides a coating material supplying device 47 or 87 to a sprayer 41 or 81 via a coating passage 49 or 89, as illustrated in the principle diagram of the first or second embodiment in FIG. 4 or FIG. In a coating device connected to a plurality of solvent supply devices 5 that supply different types of solvents
3, 56, 59 or 90, 94 respectively as valve 5
5, 58, 61 or 92, 96 to the paint passage 49 or 89 via the solvent passage 54, 57, 60 or 91, 95, and the stirring device 50 or 8
3 in Figure 4, depending on the coating environment temperature.
In the case shown in the principle diagram of the embodiment, the valves 55, 58, and 61 of any of the solvent passages are opened.
In the case shown in the principle diagram of the embodiment, the valve 9 of each solvent passage
2, 96, i.e., the valve 5 of the solvent passage.
5, 58, 61 or 92, 96 is provided.

In this solvent conversion device, the valve of the solvent passage is operated according to the coating environment temperature, so that a type of solvent suitable for the coating environment temperature can be added to the paint supplied to the sprayer. Therefore, it is possible to automatically convert the solvent into one suitable for the coating environmental temperature without requiring any complicated work, so that high-quality coating can be performed efficiently.

Further, unlike the apparatus of the first invention, there is no need to predict the daily temperature change and set the time to open the valves of each solvent passage based on the prediction.

Next, an embodiment of the second invention will be described.

First Embodiment (See FIGS. 4 to 7) The apparatus of this example uses a rotary atomizing electrostatic atomizer 40 as a sprayer, as shown in FIG. 5, and as shown in FIG. Three first, second, and third solvent supply devices 53, 56, and 59 are used to supply three types of thinners with different evaporation rates to the solvent supply device, and paddle-shaped blades rotated by a motor are used in the stirring device. Using a built-in stirring device 50 or a stirring device 51 with built-in propeller-like blades rotated by a motor, as shown in FIG. 3 solenoid switching valve 6
Solvent conversion control device 64 that opens 7, 68, 69
is used. Then, as shown in FIG. 6, the paint supply device 47 is connected to the paint passage 4 through the switching valve 48.
9, a stirring device 50 or 51 and an on-off valve 52 operated by pneumatic pressure are provided in the middle of the paint passage 49, and the terminal end of the paint passage 49 is connected to the paint supply passage 42 of the electrostatic coating machine. The first, second, and third solvent supply devices 53, 56, and 59 are connected to switching valves 55, 58, and 59, respectively.
61 provided with first, second and third solvent passages 54,5
7 and 60 to the starting end of the paint passage. Further, as shown in FIG. 5, the first high-pressure air supply device 62 is connected to the pattern adjustment air supply path 43 of the electrostatic atomizer 49, and the air motor for driving the level type paint ejector 45 of the electrostatic atomizer is connected. The DC high pressure generator 63 is connected to a terminal 46 that connects to a bell-shaped paint ejector 45 which also serves as a charging electrode of an electrostatic coating machine. Furthermore, as shown in FIGS. 7 and 6, a second high pressure air supply device 6 is provided.
5 to the paint supply device 47 via the electromagnetic switching valve 66.
and a pneumatically operated switching valve 48 between the paint passage 49 and the paint passage 49;
to the pneumatically operated switching valve 55 of the first solvent passage via the first electromagnetic switching valve 67 and to the pneumatically operated switching valve 58 of the second solvent passage via the second electromagnetic switching valve 68;
Each of the pneumatically operated switching valves 61 of the third solvent passage is connected through a third electromagnetic switching valve 69, and a manually operated normally closed valve 7 is connected to the electromagnetic switching valve 66 as shown in FIG.
0 are connected in parallel, and manually operated normally closed valves 7 are connected to the first, second, and third electromagnetic switching valves 67, 68, and 69, respectively.
1, 72, and 73 are connected in parallel, and the electromagnetic switching valve 66
Connect to a power supply (not shown) via switch S,
As shown in FIG. 4, a painting environment temperature detection section 75 installed in a painting booth 74 is connected to a comparison circuit 77 via an amplifier circuit 76, as shown in FIG. Connected comparison circuit 7
7 as the first, second and third electromagnetic switching valves 67, 68, 6
9 respectively, and the coating environment temperature detection unit 75
The temperature detected by the reference temperature setting circuit 78
When the temperature is higher than the first reference temperature set in the reference temperature setting circuit 78, the first solenoid switching valve 67 is operated by the output of the comparison circuit 77, and when the second reference temperature is higher than the second reference temperature set in the reference temperature setting circuit 78 and the first reference temperature is reached, the second electromagnetic switching valve 67 is switched on. Solenoid switching valve 68
When the second reference temperature is reached, the third electromagnetic switching valve 69 is operated.

When using the device of this example, the paint supply device 47
and first, second, and third solvent supply devices 53, 56, 5
9 respectively, and the first high pressure air supply device 62
is driven to supply high-pressure air for pattern adjustment to the electrostatic atomizer 41, and the bell-shaped paint ejector 45 is driven by the air motor, and the DC high-pressure generator 63 is driven to supply high-pressure air for pattern adjustment to the electrostatic atomizer 41. The bell-shaped paint ejector 45 is charged and the second high-pressure air supply device 6
5, closes the switch S, switches the electromagnetic switching valve 66, switches the switching valve 48 between the paint supply device 47 and the paint passage 49, and switches the stirring device 50.
or 51 to open the paint passage opening/closing valve 52. Then, while the paint is supplied to the electrostatic coating machine 41 through the paint passage 49, when the temperature detected by the painting environment temperature detection section 75 is equal to or higher than the first reference temperature set in the reference temperature setting circuit 78, ,
The first electromagnetic switching valve 67 is controlled by the output of the comparison circuit 77.
is switched, the switching valve 55 of the first solvent passage is switched, and the thinner, that is, the first solvent, having an evaporation rate suitable for the coating environment temperature equal to or higher than the first reference temperature is supplied to the paint passage 49, and the first solvent The paint to which has been added is stirred by the stirring device 50 or 51 and supplied to the electrostatic coating machine 41, and is atomized and charged by the bell-shaped paint emitter 45 that also serves as a charging electrode, and the paint is painted with the paint. It is done. In addition, the coating environment temperature detection section 7
5 is the reference temperature setting circuit 7.
When the temperature is higher than the second reference temperature set to 8 and less than the first reference temperature, the output of the comparison circuit 77
The solenoid valve 68 is switched, and the switching valve 58 of the second solvent passage is switched, and the thinner, that is, the second solvent, has an evaporation rate suitable for the coating environment temperature that is higher than the second reference temperature and less than the first reference temperature. is supplied to the paint passage 49,
The paint to which the second solvent has been added is stirred by the stirring device 50 or 5.
1 and supplied to an electrostatic coating machine 41, where the coating is applied. Further, the temperature detected by the painting environment temperature detection section 75 is the second temperature.
When the reference temperature is below the reference temperature, the output of the comparison circuit 77 causes the third electromagnetic switching valve 69 to switch.
The switching valve 61 of the solvent passage is operated to switch, and a thinner, that is, a third solvent having an evaporation rate suitable for the painting environment temperature below the second reference temperature is supplied to the paint passage 49, and the third solvent is supplied to the paint passage 49.
The paint to which the solvent has been added is supplied to the electrostatic coating machine 41.

In the apparatus of this example, a first, second, or third solvent suitable for the coating environment temperature at that time is added to the paint. When the coating environment temperature changes, a solvent suitable for the changed temperature is added to the paint according to the change.

Second Embodiment (See Figures 8 to 11) As shown in Figure 9, the apparatus of this example uses an air atomizing electrostatic coating gun 82 with a built-in stirring device 83 in the sprayer. As shown in FIG. 10, two types of thinners with different evaporation rates are supplied to the solvent supply device using a stirring device 83 that rotates screw-shaped blades using an air motor built into the electrostatic coating gun 81. As shown in FIG. 11, the first and second solvent supply devices 90 and 94 of
A solvent conversion controller 110 is used which operates servo actuators 114,115. Then, as shown in FIGS. 10 and 9, the paint supply device 87
is connected to the stirring device 83 of the paint supply path 82 of the electrostatic coating gun 81 via the switching valve 88 and the paint passage 89, and the first and second solvent supply devices 90 and 94 are connected to each other as shown in FIG. Flow rate adjustment valves 92, 96
The tank 98 is connected to a paint passage 89 through a common solvent passage 99 equipped with a pump 100 and a switching valve 101. is connected to. Further, as shown in FIG. 9, the first high-pressure air supply device 102 is connected to the air supply path 85 for adjusting the atomization pattern of the electrostatic coating gun, and the second high-pressure air supply device 103 is connected to the electrostatic coating gun. The DC high pressure generator 104 is connected to a high resistor 86 connected to a charging electrode of an electrostatic coating gun. Further, as shown in FIG. 10, the third high-pressure air supply device 105 is connected to a pneumatically operated switching valve 88 between the paint supplying device 87 and the paint passage 89, and a pneumatically operated switching valve 101 in the common solvent passage. The fourth high-pressure air supply device 106 is connected to the pneumatically operated on-off valves 93 and 97 of the first and second solvent passages via the electromagnetic switching valve 107, respectively, and the electromagnetic switching valve 107 is connected to the tank 98. The electromagnetic switching valve 107 is connected to a power source (not shown) through a liquid level detection switch 108 provided in the tank 98 to operate the electromagnetic switching valve 107 when the liquid level of the solvent in the tank 98 becomes lower than a set height. Further, as shown in FIG. 8, a coating environment temperature detection section 111 installed in the coating booth 109 is connected to a ratio setting device 113 via an amplifier circuit 112 as shown in FIG. 113 are connected to the first and second servo actuators 114 and 115, respectively, the first servo actuator 114 is connected to the flow rate adjustment valve 92 of the first solvent passage, and the second servo actuator 115 is connected to the second solvent passage. flow rate adjustment valve 96
and drives both the first and second servo actuators 114 and 115, respectively, according to the ratio set in the ratio setting device 113 according to the temperature detected by the coating environment temperature detection section 111. Then, the opening degrees of the flow rate adjustment valves 92 and 96 of both the first and second solvent passages are adjusted, respectively, and the mixing ratio of both the first and second solvents is adjusted to the ratio set in the ratio setting device 113. It is equipped like this.

When using the device of this example, the paint supply device 87
and the first and second solvent supply devices 90 and 94, respectively, and the first high-pressure air supply device 102 to supply high-pressure air for atomization and pattern adjustment to the electrostatic coating gun 81. 2 High pressure air supply device 10
3 to drive the stirring device 83 of the electrostatic coating gun, drive the DC high pressure generator 104 to charge the charging electrode of the electrostatic coating gun 81, and drive the fourth high pressure air supply device 106. Then, when the liquid level of the solvent in the tank 98 is lower than the set height, the liquid level detection switch 108 closes, the electromagnetic switching valve 107 switches, and the opening/closing valves 93 and 9 of the first and second solvent passages are switched.
7 open together. Common solvent passage pump 100
, the third high-pressure air supply device 105 is driven, and both the switching valves 88 and 101 are switched. Then, while the paint is supplied to the electrostatic coating gun 81 via the switching valve 88 and the paint passage 89, the flow rates of the first and second solvent passages are changed depending on the temperature detected by the painting environment temperature detection section 111. The opening degrees of the regulating valves 92 and 96 are determined by the first and second servo actuators 11, respectively.
4 and 115, both the first and second solvents flow into tank 98 at flow rates regulated by their flow rate regulating valves 92 and 96, respectively.
Both solvents in 8 flow into the paint passage 89 through a common solvent passage 99, and the two solvents having different evaporation rates mixed at a ratio set in the ratio setting device 113 according to the painting environment temperature at that time perform electrostatic coating. Both solvents are added to the paint supplied to the gun 81, and the paint is stirred by the stirring device 83 for painting. If the coating environment temperature changes, both solvents are mixed in a ratio set according to the temperature after the change and are added to the paint, so that painting is always done with paint that has added the solvent suitable for the coating environment temperature at that time. It can be done.

If the on-off valve V of the third high-pressure air supply device 105 is temporarily closed during painting, the painting is temporarily interrupted and paint is cut. Therefore, the on-off valve V may be opened and closed in conjunction with a reciprocator (not shown) that reciprocates the electrostatic coating gun 81.

In each of the above embodiments, a manual airless spray gun may be used as the atomizer, and a static mixer may be used as the stirring device.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram of the embodiment of the first invention, Figs. 2 and 3 are system diagrams of the same device, Fig. 4 is a principle diagram of the first embodiment of the second invention, and Fig. 5 is a diagram of the principle of the first embodiment of the second invention. The figure is a partially cutaway side view of the atomizer used in the device of the same example, FIGS. 6 and 7 are system diagrams of the device of the same example, and FIG.
A principle diagram of a second embodiment of the invention, FIG. 9 is a partially cutaway side view of a sprayer used in the device of the same example, and FIGS. 10 and 11 are system diagrams of the device of the same example. Explanation of symbols in the drawings, Figures 1 to 3, Figure 1
Embodiments of the invention, 1: Paint gun, 6: Paint supply device, 7: First paint passage, 10: Stirring device, 13:
Second paint passage, 16: First solvent supply device, 17:
1st solvent passage, 19: control on-off valve, 21: 2nd
Solvent supply device, 22: Second solvent passage, 24: Control on-off valve, 26: Third solvent supply device, 27: Third
Solvent passage, 29: Control on-off valve, 33: Solvent conversion control device, FIGS. 4 to 7, 1st embodiment of the second invention, 41: Electrostatic coating machine, 47: Paint supply device,
49: Paint passage, 50, 51: Stirring device, 53:
First solvent supply device, 54: First solvent passage, 55:
switching valve, 56: second solvent supply device, 57: second solvent passage, 58: switching valve, 59: third solvent supply device, 60: third solvent passage, 61: switching valve, 64:
Solvent conversion control device, FIGS. 8 to 11, second embodiment of the second invention, 81: electrostatic coating gun, 83: stirring device, 87: paint supply device, 89: paint passage,
90: first solvent supply device, 91: first solvent passage,
92: Flow rate adjustment valve, 94: Second solvent supply device, 9
5: second solvent passage, 96: flow rate adjustment valve, 110:
Solvent exchange control device.

Claims (1)

[Scope of Claims] 1. In a coating device in which a paint supply device is connected to a sprayer through a paint passage, a plurality of solvent supply devices for supplying different types of solvents are connected to the paint passage through solvent passages each having a valve. A solvent conversion device characterized in that a stirring device is provided in a paint passage located downstream of the connection, and a solvent conversion control device is provided that sequentially opens valves of the solvent passage according to a preset time. 2. In a coating device in which a paint supply device is connected to a sprayer through a paint passage, a plurality of solvent supply devices that supply different types of solvents are connected to the paint passage through a solvent passage each equipped with a valve, and this connection part What is claimed is: 1. A solvent conversion device comprising: a stirring device provided in a paint passage at a downstream position; and a solvent conversion control device for operating a valve in the solvent passage according to the coating environment temperature.