Powder coating apparatus

Abstract

To provide a powder coating apparatus easy to clean at the time of color change and capable of performing high quality coating hard to stick foreign matter or refuse to an object to be coated.SOLUTION: The powder coating device 10 of the present embodiment includes a coating gun 50 that sprays powder coating material to an object to be coated W accommodated in a coating chamber 20, a support portion 60 that supports the coating gun 50, an air supply portion 70 that supplies air to the coating chamber 20, and an exhaust portion 80 that exhausts air from the coating chamber 20, wherein the coating chamber 20 includes a workpiece accommodation portion 23 that accommodates the object to be coated W, a coating machine accommodation portion 24 that accommodates the support portion 60, and a first partition wall 25 that partitions the workpiece accommodation portion 23 and the coating machine accommodation portion 24, in the coating gun 50 supported by the support part 60, at least a part of the coating gun 50 is disposed in the workpiece accommodation part 23 through the 25a of the opening part provided in the first partition wall 25, and the first partition wall 25 is connected to the 20c of the upper wall of the coating chamber 20 without a gap.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a powder coating apparatus for powder coating an object to be coated. [Background technology]

[0002] In powder coating, not all of the powder paint sprayed onto the object to be coated adheres to the object, so it is necessary to prevent the powder paint that does not adhere to the object from scattering. Therefore, powder coating has conventionally been performed using a powder coating device that includes a paint booth that houses the object to be coated, a paint sprayer installed outside the paint booth, an air supply device that supplies air into the paint booth, and an exhaust device that exhausts the air from the paint booth (see, for example, Patent Documents 1 and 2 below).

[0003] In such a powder coating device, the paint gun of the sprayer is inserted into the paint booth through an opening provided in the booth, and the powder paint is sprayed onto the object to be coated from the paint gun inside the paint booth while the air supplied to the paint booth by the air supply device is exhausted from the paint booth by the exhaust device, and the powder paint that does not adhere to the object to be coated is collected. The collected powder paint is either discarded or, after removing foreign matter, is supplied to the paint gun of the sprayer and reused.

[0004] Furthermore, Patent Document 3 listed below describes a method in which the interior of a painting booth is partitioned by inner walls, the object to be painted is transported into the space partitioned by the inner walls, and powder paint is sprayed onto the object from a painting gun within the space. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-255916 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-156488 [Patent Document 3] Japanese Patent Application Publication No. 11-216404 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when changing the color of powder paint using the same powder coating equipment, the powder paint that has accumulated in the coating booth is blown away with an air blower to clean the booth before powder coating with a different color is carried out.

[0007] When cleaning a paint booth, powder paint that adheres to the booth can spread outside through the openings in the booth and adhere to the sprayer and its surroundings. If powder paint remains on the outside of the booth after a color change, it can re-enter the booth through the openings and cause different colors of powder paint to mix, resulting in poor coating results. Therefore, to perform high-quality powder coating, it is necessary to clean the exterior of the paint booth as well as the interior when changing colors.

[0008] However, conventional powder coating equipment does not take into consideration the ease of cleaning the exterior of the paint booth, making it more difficult to clean the exterior than the interior of the paint booth, and color change operations require a lot of time.

[0009] In addition, Patent Document 3 describes a technique in which the interior of a paint booth is partitioned by an inner wall, and the workpiece is placed in the space, and powder coating is performed. However, in Patent Document 3, a reciprocator for moving the paint gun is provided at the top of the paint booth, and the upper end of the inner wall of the booth is separated from the upper wall of the paint booth. As a result, powder paint may splash outside the inner wall of the booth through the gap between the upper end of the inner wall of the booth and the upper wall of the paint booth.

[0010] The present invention has been made in consideration of the above points, and its object is to provide a powder coating device that makes it easy to clean the inside and outside of the painting booth and can shorten the time required for color change operations. [Means for solving the problem]

[0011] The present invention includes the embodiments shown below.

[0012] [1] A powder coating apparatus comprising a coating chamber for accommodating objects to be coated, a coating gun for spraying powder paint onto the objects to be coated accommodated in the coating chamber, an air intake section for supplying air to the coating chamber, and an exhaust section for discharging air from the coating chamber, wherein the exhaust section comprises an exhaust chamber located below the coating chamber for receiving air discharged downward from the coating chamber, a plurality of spray devices for blowing off powder paint accumulated on the bottom surface of the exhaust chamber, and a recovery section for recovering the powder paint blown off by the spray devices, and wherein, in a plan view, the plurality of spray devices are arranged at intervals in the spray direction in which the air is sprayed.

[0013] [2] A powder coating apparatus according to [1] above, wherein a plurality of the spraying devices are provided at intervals in a direction perpendicular to the spraying direction in a plan view.

[0014] [3] A powder coating apparatus according to [1] or [2] above, wherein the recovery section is positioned further away from the spraying device in the spraying direction.

[0015] [4] A powder coating apparatus as described in [3] above, wherein the plurality of spray devices spray air in sequence, with staggered timing, from the spray device located farther from the collection section to the spray device located closer to the collection section. [Effects of the Invention]

[0016] According to the present invention, the paint gun and its support are installed along with the object to be painted in a painting chamber where air is supplied and exhausted by an air supply section and an exhaust section, which makes cleaning easier when changing colors and shortens the time required for color changes. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a powder coating apparatus according to a first embodiment of the present invention; [Figure 2] Cross section AA of Figure 1 [Figure 3] FIG. 1 is a plan view showing a schematic configuration of an exhaust chamber of a powder coating apparatus according to a first embodiment of the present invention. [Figure 4] Block diagram showing the control configuration of the powder coating device of FIG. 1. [Figure 5] FIG. 1 is a cross-sectional view showing a schematic configuration of a powder coating apparatus according to a second embodiment of the present invention. [Figure 6] Cross section B-B of Figure 5 [Figure 7] CC cross section of Figure 6 [Figure 8] FIG. 10 is a plan view showing a schematic configuration of an exhaust chamber of a powder coating apparatus according to a second embodiment of the present invention. [Figure 9] 1A is a cross-sectional view of a powder coating device according to a first modified example, and FIG. 1B is a cross-sectional view of a powder coating device according to another modified example of the first modified example. [Figure 10] Cross-sectional view of powder coating device of modified example 3 [Figure 11] Cross-sectional view of a powder coating device showing another example of modified example 3 DETAILED DESCRIPTION OF THE INVENTION

[0018] 1. First embodiment A powder coating apparatus according to a first embodiment of the present invention will now be described with reference to FIGS.

[0019] (1) Overall configuration of powder coating device 10 The powder coating apparatus 10 of this embodiment comprises a coating chamber 20, a coating gun 50, a support section 60, an air intake section 70, an exhaust section 80, a purification device 90, and a control device 100, and is an apparatus in which the coating gun 50 sprays powder paint onto the object to be coated W inside the coating chamber 20 to coat the object to be coated W.

[0020] (2) Paint Room 20 As shown in Figures 1 and 2, the coating chamber 20 comprises a front wall 20a with an entrance 21, a rear wall 20b with an exit 22, an upper wall 20c connecting the upper ends of the front wall 20a and the rear wall 20b, a lower wall 20d connecting the lower ends of the front wall 20a and the rear wall 20b, and a pair of side walls 20e connecting the left and right side ends of the front wall 20a and the rear wall 20b, and an approximately rectangular parallelepiped space is formed inside to accommodate the workpiece W, the coating gun 50, and the support part 60.

[0021] In this specification, the terms "front-rear direction," "left-right direction," and "up-down direction" refer to directions when viewed from the front of the entrance 21 of the coating room 20. Unless otherwise specified, the terms "right," "left," "up," "down," "front," and "rear" refer to positions or sides when viewed from the front of the entrance 21.

[0022] Inside the painting chamber 20, there are a work storage section 23 that stores the object to be painted W, a painting machine storage section 24 that stores the support section 60, and a partition wall 25 that separates the work storage section 23 from the painting machine storage section 24.

[0023] The workpiece storage section 23 is a space that is surrounded by the front wall 20a, rear wall 20b, upper wall 20c, and lower wall 20d that make up the coating chamber 20, and a partition wall 25, and forms a coating booth where the object to be coated W is coated. The workpiece storage section 23 is connected to the outside of the coating chamber 20 via an entrance 21 provided in the front wall 20a and an exit 22 provided in the rear wall 20b. A transport rail 26 that extends in the front-to-rear direction from the entrance 21 to the exit 22 is provided at the top of the workpiece storage section 23.

[0024] A hanger 27 for suspending the object to be coated W is attached to the transport rail 26. The hanger 27, together with the transport rail 26 and a drive unit 29 (see FIG. 4), constitutes a transport unit. The hanger 27 receives a driving force from the drive unit 29 and moves back and forth along the conveying rail 26, thereby transporting the workpiece W from the entrance 21 into the work storage section 23, moving the workpiece W back and forth from the entrance 21 to the exit 22 within the work storage section 23, and then transporting the workpiece W from the exit 22 to the outside of the work storage section 23.

[0025] In addition, a blocking device 28 is provided near the entrance 21 and the exit 22. The blocking device 28 blows air across the entrance 21 and the exit 22, thereby forming an air curtain that suppresses air circulation between the inside and outside of the coating chamber 20.

[0026] The sprayer housing section 24 is a space located on both the left and right sides of the workpiece housing section 23 inside the coating chamber 20, and is surrounded by a front wall 20a, a rear wall 20b, an upper wall 20c, a lower wall 20d, and a side wall 20e that constitute the coating chamber 20, as well as a partition wall 25. The sprayer housing section 24 is provided with a support section 60 that supports a coating gun 50.

[0027] The partition wall 25 is a wall provided between the workpiece storage section 23 and the coater storage section 24 so as to connect the upper wall 20c and the lower wall 20d, and is provided so as to separate the workpiece storage section 23 and the coater storage section 24 into left and right sections over the entire front-to-rear direction of the workpiece storage section 23 and the coater storage section 24. The partition wall 25 may be connected to the upper wall 20c and the lower wall 20d without any gaps, or may be provided with a gap between the partition wall 25 and the lower wall 20d.

[0028] Air purified by the purification device 90 flows from the upper wall 20c into the workpiece accommodating section 23 and the coater accommodating section 24. The air that flows from the upper wall 20c into the workpiece accommodating section 23 flows downward within the workpiece accommodating section 23 and is discharged from the lower wall 20d. The air that flows from the upper wall 20c into the coater accommodating section 24 flows downward within the coater accommodating section 24 and is discharged from the lower wall 20d. The flow rate of air flowing through the workpiece accommodating section 23 is preferably greater than that of the coater accommodating section 24.

[0029] In addition, from the viewpoint of preventing powder paint from scattering outside the painting chamber 20 from the entrance 21 or exit 22 of the painting chamber 20, it is preferable that the air pressure in the work storage section 23 and the paint sprayer storage section 24 be in a negative pressure state lower than the air pressure outside the painting chamber 20.

[0030] The partition wall 25 has an opening 25a that connects the workpiece accommodating section 23 and the paint sprayer accommodating section 24. The opening 25a of the partition wall 25 has a vertically elongated slit shape, and the paint gun 50 supported by the support part 60 is inserted through the opening 25a, with at least a portion of the paint gun 50 protruding from the paint sprayer accommodating section 24 through the opening 25a into the workpiece accommodating section 23 so that a nozzle provided at the tip of the paint gun 50 is positioned in the workpiece accommodating section 23.

[0031] In this embodiment, a paint sprayer storage section 24 for storing the support section 60 is provided on both the left and right sides of the work storage section 23, and the paint gun 50 protrudes from both the left and right sides of the work storage section 23, but it is also possible to provide the paint sprayer storage section 24 on only one of the left and right sides of the work storage section 23 and have the paint gun 50 protrude from only one of the left and right sides of the work storage section 23.

[0032] (3) Paint gun 50 and support unit 60 The paint gun 50 is an electrostatic powder paint gun, and is connected via piping to a paint supply device 52 (see FIG. 4). The paint gun 50 receives a supply of powder paint from the paint supply device 52 and sprays the powder paint from a nozzle onto the workpiece W in the workpiece storage section 23. The charging method of the paint gun 50 may be either a friction charging type or a corona charging type.

[0033] The support unit 60 is a reciprocator that supports one or more paint guns 50 and moves the supported paint guns 50 up and down.

[0034] (4) Air Intake Section 70 and Exhaust Section 80 An air intake section 70 and an exhaust section 80 are connected to the painting chamber 20, and air purified by a purification device 90 is supplied to the painting chamber 20 through the air intake section 70, and the air in the painting chamber 20 is discharged to the outside through the exhaust section 80. In this embodiment, air circulates between the painting chamber 20 and the purification device 90 so that the air exhausted from the painting chamber 20 by the exhaust section 80 is purified by the purification device 90, and then the purified air is supplied from the air intake section 70 to the painting chamber 20.

[0035] Specifically, the air supply section 70 includes an air supply chamber 72 provided above the coating chamber 20, and an air supply duct 71 connecting the air supply chamber 72 with the purification device 90. An air outlet 73 communicating with the air supply chamber 72 and the workpiece housing section 23, and an air outlet 74 communicating with the air supply chamber 72 and the coater housing section 24 are provided in the upper wall 20c that separates the air supply chamber 72 from the coating chamber 20.

[0036] The air purified in the purification device 90 is supplied to the air supply chamber 72 through the air supply duct 71, and then supplied to the work storage section 23 through the air outlet 73 and to the paint sprayer storage section 24 through the air outlet 74.

[0037] The exhaust section 80 includes an exhaust chamber 82 provided below the coating chamber 20, and an exhaust duct 81 connecting the exhaust chamber 82 to the purification device 90. The lower wall 20d, which separates the exhaust chamber 82 from the coating chamber 20 into upper and lower sections, is made of a grating floor with many holes, and the workpiece storage section 23 and the coating machine storage section 24 of the coating chamber 20 communicate with the exhaust chamber 82 through the many holes provided in the lower wall 20d.

[0038] When the fan 92 provided in the purification device 90 operates to suck in air from the exhaust duct 81, the air from the workpiece housing section 23 and the coater housing section 24 flows into the exhaust chamber 82 through the holes in the lower wall 20d. The air that has flowed into the exhaust chamber 82 passes through the exhaust duct 81 and is taken into the purification device 90, where the powder paint is removed, and the air is then introduced back into the air intake section 70.

[0039] Such air intake section 70 and exhaust section 80 may be provided with flow straightening materials 75, 83 that straighten the flow of air supplied from the air intake section 70 to the coating chamber 20 and air exhausted from the coating chamber 20 to the exhaust section 80.

[0040] For example, air supply chamber 72 may be provided with a flow straightening material 75 made of a material such as nonwoven fabric that generates pressure loss when passing through. By providing flow straightening material 75 so as to cover air outlet 73 and air outlet 74, the air supplied from air supply duct 71 to air supply chamber 72 is equalized in pressure before being supplied to workpiece housing section 23 and coater housing section 24, thereby forming a uniform air flow without turbulence in workpiece housing section 23 and coater housing section 24.

[0041] Furthermore, a flow straightening member 83 made of a flat metal or resin member may be provided in the exhaust chamber 82. The flow straightening member 83 is disposed below the bottom wall 20d at a distance, and by adjusting the distance from the bottom wall 20d and the area facing the bottom wall 20d, the flow rate of air exhausted from the workpiece accommodating section 23 and the coater accommodating section 24 is adjusted, thereby adjusting the flow rate of air flowing through the workpiece accommodating section 23 and the coater accommodating section 24.

[0042] When adjusting the flow rate of air flowing through the work accommodating section 23 and the coater accommodating section 24, it is preferable to adjust the flow rate of air exhausted from the work accommodating section 23 to the exhaust chamber 82 so that it is greater than the flow rate of air supplied from the air supply chamber 72 to the work accommodating section 23, and to adjust the air pressure in the work accommodating section 23 to a negative pressure lower than the air pressure outside the coating chamber 20. It is also preferable to provide flow straightening materials 75, 83 so that the flow rate of air supplied from the air supply chamber 72 to the work accommodating section 23 is greater than the flow rate of air supplied from the air supply chamber 72 to the coater accommodating section 24, and the flow rate of air flowing through the work accommodating section 23 is greater than that of the coater accommodating section 24.

[0043] 1 and 3, the exhaust chamber 82 may be provided with a plurality of sprayers 84 that spray air in a predetermined direction (for example, to the right in this embodiment), and a collection unit 85. Specifically, in a plan view as shown in FIG. 3, the plurality of sprayers 84 may be provided at intervals in the predetermined direction, that is, at intervals in the direction in which the sprayers 84 spray air (hereinafter, this direction may also be referred to as the spraying direction). The sprayers 84 may also be provided at intervals in a direction perpendicular to the spraying direction of the sprayers 84 (in the front-to-rear direction in this embodiment). The collection unit 85 is located further away from the sprayers 84 in the spraying direction, and collects powder paint blown away by the air sprayed from the sprayers 84.

[0044] The purification device 90 includes a dust collector 91 and a fan 92. An exhaust duct 81 is connected to the dust collector 91, and air exhausted from the coating chamber 20 is introduced into the dust collector 91 via the exhaust duct 81. The dust collector 91 removes powder paint contained in the introduced air using a bag filter or the like. The powder paint removed by the dust collector 91 is collected in a collection tank 93 provided below the dust collector 91.

[0045] In the recovery tank 93, recyclable powder paint is selected from the recovered powder paint, and the selected recyclable powder paint is supplied to the paint supply device 52 via a pipe.

[0046] (5) Control device 100 4, the powder coating apparatus 10 is equipped with a control device 100 that controls the operation of the powder coating apparatus 10. The shutoff device 28, the drive device 29, the paint supply device 52, the support part 60, the spray device 84, and the fan 92 are electrically connected to the control device 100, and controls the operation of each device.

[0047] (6) Operation of the powder coating device 10 Next, the operation of the powder coating apparatus 10 of this embodiment will be described.

[0048] First, an unpainted object W to be painted is hung on a hanger 27 outside the painting chamber 20, and the driving device 29 transports the object W along the conveying rail 26 from the entrance 21 of the painting chamber 20 into the work storage section 23 of the painting chamber 20.

[0049] The workpiece W carried into the work storage section 23 is sprayed with powder paint from the paint gun 50 while moving from the entrance 21 to the exit 22 within the work storage section 23. The control device 100 drives the paint supply device 52 to spray a predetermined amount of powder paint from the paint gun 50. During this process, the control device 100 moves the paint gun 50 up and down using the support part 60 as necessary.

[0050] Then, when the painting of the workpiece W is completed, the control device 100 drives the driving device 29 to carry the painted workpiece W out of the painting chamber 20 through the exit 22.

[0051] When the workpiece W is being painted in the work storage section 23, some of the powder paint discharged from the paint gun 50 does not adhere to the workpiece W and remains in the painting chamber 20. Therefore, the control device 100 drives the fan 92 of the purification device 90 to suck the air in the workpiece storage section 23 and the paint sprayer storage section 24 through the exhaust section 80, and the floating powder paint is discharged from the workpiece storage section 23 and the paint sprayer storage section 24 together with the air.

[0052] The air containing powder paint discharged from the workpiece storage section 23 and the coater storage section 24 flows into the purification device 90 through the exhaust duct 81, and the powder paint is removed by the dust collector 91. The air from which the powder paint has been removed flows into the air supply chamber 72 through the air supply duct 71 by the blowing action of the fan 92, and is supplied to the workpiece storage section 23 and the coater storage section 24 through the air outlets 73, 74.

[0053] The powder paint separated from the air by the dust collector 91 is collected in a collection tank 93, and after foreign matter is removed, it is returned to the paint supply device 52 and used again for painting.

[0054] In addition to during painting of the workpiece W, when an unpainted workpiece W is carried into the work storage section 23 or when a painted workpiece W is carried out of the painting chamber 20 from the work storage section 23, the control device 100 may drive the fan 92 of the purification device 90 to circulate air in the workpiece storage section 23 and the paint sprayer storage section 24. When carrying in an unpainted workpiece W or carrying out a painted workpiece W, the rotation speed of the fan 92 may be reduced compared to when the workpiece W is being painted, or the fan 92 may be stopped.

[0055] Furthermore, during color change operations or cleaning of the coating room 20, the control device 100 drives the fan 92 of the purification device 90 to suck air from the workpiece storage section 23 and the coater storage section 24 through the exhaust section 80, while the air blower blows away the powder paint that has accumulated in the workpiece storage section 23 and the coater storage section 24. As a result, the powder paint blown away by the air blower is discharged together with the air from the workpiece storage section 23 and the coater storage section 24 and is collected in the purification device 90.

[0056] At this time, the control device 100 may inject air from the spray devices 84. Specifically, the control device 100 injects air at different times in order from the spray device 84 located farther from the collection section 85 to the spray device 84 located closer to the collection section 85, so that the powder paint accumulated at the bottom of the exhaust chamber 82 is blown away in the direction of injection of the spray devices 84 and sent to the collection section 85.

[0057] In this embodiment, the powder paint recovered in the recovery tank 93 is supplied to the paint supply device 52 for reuse, but the recovered powder paint may be discarded without being reused.

[0058] (7) Effects In the powder coating apparatus 10 of this embodiment, the paint gun 50 and support unit 60 are provided in the coating chamber 20, which is connected to the air intake unit 70 and exhaust unit 80 and supplied with purified air, and no opening is provided in the wall separating the coating chamber 20 from the outside to allow insertion of the paint gun 50. This makes it difficult for foreign matter to enter the workpiece storage unit 23 from outside the coating chamber 20, enabling high-quality powder coating to be performed.

[0059] In addition, in the powder coating apparatus 10 of this embodiment, the exhaust section 80 is connected not only to the work storage section 23 where the workpiece W is painted, but also to the painter storage section 24 which is provided with a support section 60 that supports the paint gun 50, so that the internal air of the painter storage section 24 can be exhausted.

[0060] In such powder coating apparatus 10, when changing colors or cleaning the coating chamber 20, the accumulated powder paint can be blown away with an air blower not only in the workpiece storage section 23 but also in the coating machine storage section 24, and recovered from the exhaust section 80 without diffusing outside the coating chamber 20. This makes cleaning easier when changing colors and shortens the time required for color changes.

[0061] In the powder coating apparatus 10, the workpiece storage section 23 and the coater storage section 24 are separated by a partition wall 25, and the nozzle of the paint gun 50 is placed in the workpiece storage section 23 through an opening 25a provided in the partition wall 25. This makes it difficult for the air flowing through the workpiece storage section 23 to be affected by the support section 60 and other factors, making it difficult for turbulence to occur in the workpiece storage section 23. As a result, high-quality powder coating can be performed in which the powder paint is sprayed evenly onto the workpiece W.

[0062] In the powder coating device 10, by providing flow straightening materials 75, 83 in the air supply chamber 72 and the exhaust chamber 82, it is possible to control the air flow rate flowing through the work storage section 23 and the paint sprayer storage section 24, and to generate a uniform air flow in the work storage section 23 and the paint sprayer storage section 24.

[0063] In the powder coating apparatus 10, when the air is circulated so that the powder paint is removed from the air discharged from the coating chamber 20 and then returned to the coating chamber 20, it is difficult for air to flow into the coating chamber 20 from the outside, making it easier to maintain constant temperature and humidity environments within the coating chamber 20. This makes it easier to stabilize the coating environment and improve the coating quality. When an operator works in the coating chamber 20, it becomes easier to control the interior of the coating chamber 20 to create a comfortable environment that is easy for the operator to work in.

[0064] In the powder coating device 10, by providing a plurality of spray devices 84 in the exhaust chamber 82 at intervals in the spray direction of the spray devices 84, the powder paint accumulated at the bottom of the exhaust chamber 82 can be blown away and collected in a recovery section 85.

[0065] In the powder coating apparatus 10, by providing a blocking device 28 at the entrance 21 and exit 22 of the coating chamber 20, it is possible to prevent poor coating caused by foreign matter entering the coating chamber 20 from the outside and to prevent powder paint from diffusing outside the coating chamber 20.

[0066] In the powder coating apparatus 10, when the air intake section 70 supplies air from the upper side of the coating chamber 20 and the exhaust section 80 exhausts air from the lower side of the coating chamber 20, a uniform air flow from the upper wall 20c to the lower wall 20d is easily generated within the work storage section 23, making it possible to perform high-quality powder coating in which the powder paint is sprayed evenly onto the object to be coated W.

[0067] In this embodiment, the air pressure in the work storage section 23 is adjusted to a negative pressure state lower than the air pressure outside the coating chamber 20, thereby preventing the powder paint sprayed into the work storage section 23 from scattering outside the coating chamber 20 from the inlet 21 or outlet 22.

[0068] In this embodiment, the flow rate of air supplied from the air supply chamber 72 to the work storage section 23 is greater than the flow rate of air supplied from the air supply chamber 72 to the paint sprayer storage section 24, so the powder paint sprayed into the work storage section 23 can be quickly discharged into the exhaust chamber 82.

[0069] 2. Second embodiment The second embodiment will be described mainly with reference to Figures 5 to 8. In this embodiment, elements that are the same as or correspond to those in the first embodiment are given the same reference numerals, and duplicated descriptions will be omitted.

[0070] As shown in Figures 5 to 8, the powder coating apparatus 210 of this embodiment differs from the first embodiment in that the workpiece storage section 23 provided inside the coating chamber 20 has an exhaust area 231 and an air supply area 232.

[0071] (1) Paint Room 20 The coating chamber 20 is provided with an exhaust area 231 in the center of the workpiece storage section 23 in the front-to-rear direction, where powder paint is sprayed onto the workpiece W to coat the workpiece W, and air supply areas 232 are provided on both front-to-rear directions of the exhaust area 231. The air supply area 232 is connected to the outside of the coating chamber 20 via an inlet 21 provided in the front wall 20a and an outlet 22 provided in the rear wall 20b.

[0072] A partition wall 25 (hereinafter sometimes referred to as the first partition wall 25) separating the workpiece accommodation section 23 from the sprayer accommodation section 24 has a vertically elongated slit-shaped opening 25a in a portion facing the exhaust area 231. A paint gun 50 supported by a support section 60 is inserted into the opening 25a of the first partition wall 25, and at least a portion of the paint gun 50 protrudes from the sprayer accommodation section 24 through the opening 25a into the exhaust area 231 so that a nozzle provided at the tip of the paint gun 50 is positioned in the exhaust area 231.

[0073] Two second partition walls 233 are provided in the workpiece accommodating section 23, spaced apart in the front-rear direction. The second partition walls 233 are provided facing the front wall 20a and the rear wall 20b of the coating chamber 20 in the front-rear direction, dividing the workpiece accommodating section 23 into front and rear sections. An exhaust area 231 is formed between the two second partition walls 233. An air supply area 232 is formed between the front wall 20a and one of the second partition walls 233, and between the rear wall 20b and the other second partition wall 233. The second partition walls 233 are provided with communication ports 234 at positions facing the inlet 21 of the front wall 20a and the outlet 22 of the rear wall 20b in the front-rear direction. The exhaust area 231 is in communication with the air supply area 232 via the communication ports 234 provided in the second partition walls 233.

[0074] It is preferable that the second partition wall 233 is connected without any gaps to the left and right first partition walls 25. It is also preferable that the second partition wall 233 is connected without any gaps to the upper wall 20c, and it is more preferable that the second partition wall 233 is connected without any gaps to the upper wall 20c and the lower wall 20d.

[0075] A transport rail 26 provided at the top of the workpiece storage section 23 extends in the front-rear direction from the entrance 21 in the front wall 20a through the communication opening 234 in the second partition wall 233 to the exit 22 in the rear wall 20b. The hanger 27 attached to the transport rail 26 receives a driving force from the drive unit 29 and moves back and forth along the transport rail 26. As a result, the hanger 27 transports the workpiece W from the entrance 21 into the workpiece accommodating section 23, moves the workpiece W through the air supply area 232 on the entrance 21 side, the exhaust area 231, and the air supply area 232 on the exit 22 side in that order within the workpiece accommodating section 23, and then transports the workpiece W from the exit 22 to the outside of the workpiece accommodating section 23.

[0076] (2) Air intake section 270 and exhaust section 280 The painting chamber 20 is connected to an air intake section 270 and an exhaust section 280. The air purified by the purification device 90 is supplied through the air intake section 270 to the air intake area 232 of the workpiece housing section 23 and the coater housing section 24 provided in the painting chamber 20, and the air inside the painting chamber 20 is discharged from the exhaust area 231 of the workpiece housing section 23 to the exhaust section 280. The air exhausted from the painting chamber 20 is purified by the purification device 90, and then circulates between the painting chamber 20 and the purification device 90 so that it is supplied from the air intake section 270 to the air intake area 232 and the coater housing section 24.

[0077] Specifically, the air supply section 270 includes an air supply chamber 272 provided above the coating chamber 20, and an air supply duct 271 connecting the air supply chamber 272 with the purification device 90. An upper wall 20c that separates the air supply chamber 272 from the coating chamber 20 vertically is provided with an air outlet 273 (see FIG. 7) that communicates with the air supply chamber 272 and the air supply region 232 of the workpiece housing section 23, and an air outlet 274 (see FIG. 5) that communicates with the air supply chamber 272 and the coater housing section 24.

[0078] The exhaust section 280 includes an exhaust chamber 282 provided below the coating chamber 20, and an exhaust duct 281 connecting the exhaust chamber 282 and the purification device 90. In this embodiment, as shown in Fig. 8, the exhaust chamber 282 is provided below the exhaust area 231 of the coating chamber 20. A suction port 286 (see Figs. 5 and 7) communicating with the exhaust chamber 282 and the exhaust area 231 is provided in the lower wall 20d that separates the exhaust chamber 282 from the exhaust area 231 of the workpiece accommodating section 23 into upper and lower sections.

[0079] In addition, the lower wall 20d provided in the exhaust area 231 of the work storage section 23 consists of a grating floor with a large number of holes, and the large number of holes function as suction ports 286 that connect the exhaust area 231 of the work storage section 23 to the exhaust chamber 282.

[0080] In the powder coating apparatus 210 of this embodiment, when the fan 92 provided in the purification device 90 operates to suck in air from the exhaust duct 281, the air in the exhaust area 231 of the workpiece housing section 23 flows into the exhaust chamber 282 through the suction port 286 in the lower wall 20d. The air that has flowed into the exhaust chamber 282 passes through the exhaust duct 281 and is taken into the purification device 90, where the powder paint is removed and purified.

[0081] The air purified in the purification device 90 is supplied to the air supply chamber 272 through the air supply duct 271, and then supplied to the air supply area 232 of the work storage section 23 through the air outlet 273, and also supplied to the paint sprayer storage section 24 through the air outlet 274.

[0082] In this embodiment, by the operation of the fan 92 provided in the purification device 90, the air in the exhaust area 231 of the work storage section 23 is discharged to the exhaust section 280, and the air in the air supply area 232 and the paint sprayer storage section 24 flows into the exhaust area 231 through the opening 25a of the first partition wall 25 and the communication port 234 of the second partition wall 233 and is discharged from the exhaust area 231 to the exhaust section 280, but part of the air in the air supply area 232 and the paint sprayer storage section 24 may also be discharged to the exhaust section 280 from an intake port provided in the lower wall 20d.

[0083] When part of the air in the air supply area 232 or the paint machine storage section 24 is discharged to the exhaust section 280 from the intake port provided in the lower wall 20d, the flow rate of air discharged from the air supply area 232 of the work storage section 23 or the paint machine storage section 24 to the exhaust section 280 is set to be less than the flow rate of air discharged from the exhaust area 231 of the work storage section 23 to the exhaust section 280.

[0084] In addition, in this embodiment, air is supplied from the air intake section 270 to the air intake area 232 and the paint sprayer housing section 24 by operation of the fan 92 provided in the purification device 90, and air is supplied from the air intake area 232 and the paint sprayer housing section 24 to the exhaust area 231, but part of the air from the air intake section 270 may also be supplied to the exhaust area 231.

[0085] When part of the air in the air intake section 270 is supplied to the exhaust area 231, the flow rate of the air supplied from the air intake section 270 to the exhaust area 231 is less than the flow rate of the air supplied from the air intake section 270 to the air intake area 232 and the paint sprayer storage section 24.

[0086] The air pressure in the air supply area 232 of the work storage section 23 and the paint sprayer storage section 24 is higher than the air pressure in the exhaust area 231 of the work storage section 23, and a pressure difference occurs between the exhaust area 231 and the air supply area 232, and between the exhaust area 2231 and the paint sprayer storage section 24.

[0087] Due to a pressure difference generated between the exhaust area 231 and the air supply area 232, the air supplied to the air supply area 232 of the workpiece accommodating section 23 flows into the exhaust area 231 through a communication port 234 provided in the second partition wall 233. In addition, due to a pressure difference generated between the exhaust area 231 and the coater accommodating section 24, the air supplied to the coater accommodating section 24 flows into the exhaust area 231 through an opening 25a provided in the first partition wall 25.

[0088] The air that flows into the exhaust area 231 from the air intake area 232 or the paint sprayer housing section 24 flows into the exhaust chamber 282 through the intake port 286 provided in the lower wall 20d, and is taken into the purification device 90 through the exhaust duct 281.After the powder paint is removed in the purification device 90, the air is introduced back into the air intake section 70.

[0089] It is preferable that the flow rate of air supplied to the exhaust area 231 (in this embodiment, the flow rate of air flowing into the exhaust area 231 from the air supply area 232 and the coater housing section 24) is less than the flow rate of air discharged from the exhaust area 231 to the exhaust chamber 282 of the exhaust section 280, and that the air pressure in the exhaust area 231 is in a negative pressure state lower than the air pressure outside the coating chamber 20. By putting the exhaust area 231 in a negative pressure state, powder paint remaining in the exhaust area 231 without adhering to the workpiece W is less likely to diffuse outside the exhaust area 231.

[0090] Furthermore, it is preferable that the flow rate of air supplied from the air supply section 270 to the air supply area 232 be greater than the flow rate of air supplied from the air supply section 270 to the coater housing section 24. By increasing the flow rate of air supplied to the air supply area 232, powder paint remaining in the exhaust area 231 without adhering to the workpiece W is less likely to diffuse into the air supply area 232.

[0091] It is also preferable that the air pressure in the air supply region 232 be adjusted to a positive pressure state higher than the air pressure outside the coating chamber 20. This makes it possible to prevent foreign matter from entering the coating chamber 20 from the outside.

[0092] (3) Operation of the powder coating device 210 Next, the operation of the powder coating apparatus 210 of this embodiment will be described.

[0093] First, the control device 100 operates the fan 92 provided in the purification device 90. As a result, the air purified in the purification device 90 is supplied to the air supply area 232 of the workpiece housing section 23 and the coater housing section 24. The air supplied to the air supply area 232 and the coater housing section 24 flows into the exhaust area 231 from the communication port 234 of the second partition wall 233 and the opening 25a of the first partition wall 25, and is discharged from the exhaust area 231 to the exhaust chamber 282.

[0094] Then, the fan 92 provided in the purification device 90 is operated to circulate air through the air supply area 232, the paint machine storage section 24, and the exhaust area 231, and the unpainted workpiece W suspended from the hanger 27 is moved from the entrance 21 of the painting chamber 20 to the work storage section 23. The uncoated object W that has been moved to the workpiece storage section 23 is carried into the exhaust area 231 through the air supply area 232 on the inlet side.

[0095] Then, with air circulating through the air supply area 232, the sprayer housing 24, and the exhaust area 231, the control device 100 drives the paint supply device 52 to spray a predetermined amount of powder paint from the paint gun 50 onto the workpiece W that has been carried into the exhaust area 231. At this time, the control device 100 moves the paint gun 50 up and down using the support part 60 as necessary.

[0096] When powder paint is sprayed onto the workpiece W in the exhaust area 231 of the work storage section 23, some of the powder paint ejected from the paint gun 50 does not adhere to the workpiece W but remains in the exhaust area 231.

[0097] When the paint supply device 52 sprays powder paint onto the workpiece W, the fan 92 provided in the purification device 90 is operating, so that air purified in the purification device 90 is supplied to the air supply area 232 of the workpiece housing section 23 and the coater housing section 24, and air in the exhaust area 231 is discharged to the exhaust chamber 282. As a result, the powder paint remaining in the exhaust area 231 is discharged from the exhaust area 231 to the exhaust chamber 282 together with the air.

[0098] In addition, when the fan 92 of the purification device 90 is driven, the air pressure in the air supply area 232 of the work storage section 23 and the paint sprayer storage section 24 becomes higher than the air pressure in the exhaust area 231 of the work storage section 23, resulting in a pressure difference between the exhaust area 231 and the air supply area 232 and between the exhaust area 231 and the paint sprayer storage section 24.

[0099] This pressure difference causes the air supplied to the air supply area 232 of the workpiece accommodating section 23 to flow into the exhaust area 231 through the communication port 234 provided in the second partition wall 233, thereby preventing powder paint that does not adhere to the workpiece W from diffusing from the communication port 234 through the air supply area 232 to the outside of the coating chamber 20 via the inlet 21 or outlet 22. In addition, the air supplied to the coater accommodating section 24 flows into the exhaust area 231 through the opening 25a provided in the first partition wall 25, thereby preventing powder paint that does not adhere to the workpiece W from entering the coater accommodating section 24 through the opening 25a of the first partition wall 25.

[0100] Then, when painting of the workpiece W is completed, the control device 100 drives the drive device 29 while operating the fan 92 provided in the purification device 90 to transport the coated workpiece W from the communication port 234 of the second partition wall 233 through the outlet-side air supply area 232 to the outside of the painting chamber 20. Furthermore, if necessary, simultaneously with the transport of the coated workpiece W, an unpainted workpiece W is transported into the exhaust area 231, and the next workpiece W is sprayed with powder paint to paint it.

[0101] In this embodiment, the fan 92 provided in the purification device 90 is operated to circulate air through the air intake area 232, the paint sprayer storage section 24, and the exhaust area 231 not only while the workpiece W is being painted, but also while the unpainted workpiece W is being transported and the painted workpiece W is being transported. However, while the unpainted workpiece W is being transported and the painted workpiece W is being transported, the fan 92 may be stopped or the rotation speed of the fan 92 may be reduced compared to when the workpiece W is being painted.

[0102] (4) Effects In the powder coating apparatus 210 of this embodiment, the work storage section 23 is divided into an exhaust area 231 and an air supply area 232, and the air supply area 232 and the paint sprayer storage section 24 are set to a higher air pressure than the exhaust area 231, so that the powder paint can be prevented from diffusing outside the coating chamber 220 without installing a blocking device 28 such as an air curtain near the entrance 21 or exit 22 of the coating chamber 220.

[0103] In the powder coating apparatus 210 of this embodiment, a second partition wall 233 is provided between the exhaust area 231 and the air supply area 232, thereby preventing powder paint that has not adhered to the workpiece W from diffusing from the exhaust area 231 to the air supply area 232.

[0104] 3. Example of changes Next, modified examples will be described. Various modifications can be made to the above embodiment without departing from the spirit of the invention. Several modified examples will be described below, and any one of the modified examples described below may be applied to the above embodiment, or any two or more of the modified examples described below may be applied in combination. In addition to the modified examples below, various omissions, substitutions, and modifications can be made without departing from the gist of the invention. Note that components with the same configuration as the above embodiment will be assigned the same reference numerals, and descriptions of those configurations will be omitted.

[0105] (1) Change example 1 In the first embodiment described above, the air intake section 70 supplies air from the upper side of the coating chamber 20, and the exhaust section 80 exhausts air from the lower side of the coating chamber 20. However, as shown in Fig. 9(a), the air intake section 170 may supply air from the upper side of the coating chamber 20, and the exhaust section 180 may exhaust air from one side in the front-rear direction of the coating chamber 20. Alternatively, as shown in Fig. 9(b), the air intake section 270 may supply air from one side in the front-rear direction of the coating chamber 20, and the exhaust section 190 may exhaust air from the other side in the front-rear direction of the coating chamber 20.

[0106] (2) Change example 2 In the first and second embodiments described above, the air exhausted from the painting chamber 20 is purified by the purification device 90, and then the purified air is circulated between the painting chamber 20 and the purification device 90 so that it returns to the painting chamber 20. However, the air exhausted from the painting chamber 20 may be purified by a purification device before being released outside the painting chamber 20, and the air outside the painting chamber 20 may be supplied to the painting chamber 20 after foreign matter and dust have been removed using a filter such as a nonwoven fabric.

[0107] (3) Change example 3 In the first and second embodiments described above, the painting chamber 20 is provided with a work storage section 23 and a paint sprayer storage section 24, but as shown in Figure 10, a working section 130 may be provided in addition to the work storage section 23 and the paint sprayer storage section 24.

[0108] The working section 130 is provided, for example, at the rear side (exit 22 side) of the work storage section 23 and the paint machine storage section 24 within the painting chamber 120, and the object to be painted W that has been painted by spraying powder paint in the work storage section 23 is transported in by a hanger 27.

[0109] In the powder coating apparatus 140 of this modified example, air purified by the purification device 90 is supplied from the air intake sections 70, 270 to the work storage section 23, the coater storage section 24, and the working section 130, and the air in the work storage section 23, the coater storage section 24, and the working section 130 is exhausted to the exhaust section 80 and sent to the purification device 90, where the powder paint is removed before being supplied to the work storage section 23, the coater storage section 24, and the working section 130 via the air intake sections 70, 270.

[0110] In the powder coating apparatus 140 of this modified example, an operator can inspect the coated object W and repaint any defectively painted areas in the working section 130. When the working section 130 where the operator works is provided in the coating room 20 as in this modified example, it is preferable to provide air conditioners in the working section 130 and the air intake sections 70, 270 to make the working environment comfortable.

[0111] In this modified example, the working section 130 is provided within the painting chamber 20, but as shown in Figure 11, the working section 150 may be provided at a distance behind the painting chamber 20, and the working section 150 and the painting chamber 20 may be connected by a connecting section 160.

[0112] Specifically, the working section 150 includes a front wall 150a having an entrance 151, a rear wall 150b having an exit 152, an upper wall connecting the upper ends of the front wall 150a and the rear wall 150b, a lower wall connecting the lower ends of the front wall 150a and the rear wall 150b, and a pair of side walls 150e connecting the left and right side ends of the front wall 150a and the rear wall 150b.

[0113] An entrance 151 provided in the front wall 150a of the working section 150 is connected to the exit 22 of the coating chamber 20 by a connecting section 160. The connecting section 160 is surrounded by upper and lower walls and left and right side walls that connect the rear wall 20b of the coating chamber 20 and the front wall 150a of the working section 150.

[0114] The object to be painted W is transported by the hanger 27 from the exit 22 of the painting chamber 20 through the connecting section 160, transported into the working section 150 through the entrance 151 in the front wall 150a, and then transported through the working section 150 and out through the exit 152 in the rear wall 150b.

[0115] (4) Change Example 4 In the second embodiment described above, an air outlet 273 communicating with the air supply chamber 272 and the air supply area 232 of the work storage section 23, and an air outlet 274 communicating with the air supply chamber 272 and the paint sprayer storage section 24 are provided in the upper wall 20c. However, in addition to the air outlets 273 and 274, an air outlet communicating with the air supply chamber 272 and the exhaust area 231 may also be provided in the upper wall 20c.

[0116] By providing an air outlet in the upper wall 20c that communicates with the air supply chamber 272 and the exhaust area 231, an air current is generated in the exhaust area 231 that flows downward from the upper wall 20c toward the lower wall 20d, allowing for high-quality powder coating in which the powder paint is sprayed evenly onto the workpiece W.

[0117] In addition, when an air outlet is provided to supply air from the air supply chamber 272 to the exhaust area 231 as in this modified example, the flow rate of air supplied from the air supply chamber 272 to the exhaust area 231 through the air outlet is preferably less than the flow rate of air supplied from the air supply chamber 272 to the air supply area 232, and is preferably less than the flow rate of air supplied from the air supply chamber 272 to the paint sprayer housing section 24.

[0118] Furthermore, when an outlet is provided to supply air from the air supply chamber 272 to the exhaust area 231 as in this modified example, it is preferable that the flow rate of air supplied to the exhaust area 231, that is, the sum of the flow rate of air flowing into the exhaust area 231 from the air supply chamber 232 and the paint sprayer housing section 24 and the flow rate of air supplied from the air supply chamber 272 to the exhaust area 231, is less than the flow rate of air discharged from the exhaust area 231 to the exhaust chamber 282 of the exhaust section 280, and that the air pressure in the exhaust area 231 is in a negative pressure state lower than the air pressure outside the painting chamber 20.

[0119] In this modified example, the flow rate of air supplied from the air supply chamber 272 to the exhaust region 231 may be greater at the center in the front-rear direction of the exhaust region 231 than at both ends in the front-rear direction so that the flow rate is greater on the paint gun 50 side than on the communication port 234 side. This makes it less likely that the flow of air flowing from the air supply region 232 through the communication port 234 into the exhaust region 231 will be obstructed.

[0120] (5) Change Example 5 In the second embodiment described above, the suction port 286 communicating with the exhaust chamber 282 and the exhaust area 231 of the work storage section 23 is provided in the lower wall 20d. However, in addition to the suction port 286, a suction port communicating with the exhaust chamber 282 and the air supply area 232, or a suction port communicating with the exhaust chamber 282 and the paint sprayer storage section 24 may also be provided in the lower wall 20d.

[0121] When an intake port connecting the exhaust chamber 282 and the air supply area 232, or an intake port connecting the exhaust chamber 282 and the paint sprayer housing section 24 is provided in the lower wall 20d, the flow rate of air discharged from the air supply area 232 or the paint sprayer housing section 24 to the exhaust chamber 282 is set so that the air pressure in the air supply area 232 or the paint sprayer housing section 24 is higher than the air pressure in the exhaust area 231.

[0122] By providing suction ports that communicate the exhaust chamber 282 with the air supply area 232 and the coater housing 24 as in this modified example, some of the air in the air supply area 232 and the coater housing 24 is discharged from the suction ports provided in the bottom wall 20d into the exhaust chamber 282. Therefore, even if powder paint that has not adhered to the workpiece W is scattered into the air supply area 232 or the coater housing 24, it is likely to be discharged into the exhaust chamber 282 without accumulating in the air supply area 232 or the coater housing 24.

[0123] (6) Change Example 6 In the second embodiment described above, a second partition wall 233 is provided between the exhaust area 231 and the air supply area 232 of the work storage section 23, but if the air pressure in the air supply area 232 or the paint sprayer storage section 24 is higher than the air pressure in the exhaust area 231, the second partition wall 233 does not need to be provided between the exhaust area 231 and the air supply area 232. [Explanation of symbols]

[0124] 10... powder coating device, 20... coating chamber, 21... entrance, 22... exit, 23... workpiece storage section, 2 4...spray machine housing section, 25...partition wall, 25a...opening, 26...transport rail, 27...hanger, 28...shutoff device, 29...drive device, 50...paint gun, 51...nozzle, 52...paint supply device 60...support part, 70...air supply part, 71...air supply duct, 72...air supply chamber, 73...air outlet, 7 4...air outlet, 75...flow straightening material, 80...exhaust section, 81...exhaust duct, 82...exhaust chamber, 83...straightening Flow material, 84... injection device, 85... recovery section, 90... purification device, 91... dust collector, 92... fan, 93...recovery tank, 200...painting room, 210...powder coating equipment, 231...exhaust area, 232 ...air supply area, 233...second partition wall, 234...communication port, 270...air supply section, 271...air supply duct 272...air supply chamber, 273...air outlet, 274...air outlet, 280...exhaust section, 281...exhaust Duct, 282...exhaust chamber, 285...recovery section, 286...intake port, W...painted object

Claims

1. a coating chamber for accommodating an object to be coated; a coating gun that sprays powder paint onto an object to be coated housed in the coating chamber; an air supply unit that supplies air to the coating chamber; an exhaust section for discharging air from the coating chamber, The exhaust section comprises an exhaust chamber located below the coating chamber and receiving air discharged downward from the coating chamber, a plurality of spray devices that blow off powder paint accumulated on the bottom surface of the exhaust chamber, and a recovery section that recovers the powder paint blown off by the spray devices, and in a plan view, the plurality of spray devices are arranged at intervals in the spray direction in which they spray air.

2. 2. The powder coating apparatus according to claim 1, wherein a plurality of the spraying devices are provided at intervals in a direction perpendicular to the spraying direction in a plan view.

3. 2. The powder coating apparatus according to claim 1, wherein the recovery section is disposed at a position farther away from the spraying device in the spraying direction.

4. 4. The powder coating apparatus according to claim 3, wherein the plurality of spray devices spray air at different timings in sequence from the spray device located farther from the collection section to the spray device located closer to the collection section.

Images