Powder coating equipment

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 Art

[0002] In powder coating, since not all of the powder coating sprayed onto the object to be coated adheres to the object to be coated, it is necessary to prevent the scattering of the powder coating that did not adhere to the object to be coated. Therefore, conventionally, a powder coating apparatus including a coating booth for accommodating the object to be coated, a coating machine provided outside the coating booth, an air supply device for supplying air into the coating booth, and an exhaust device for exhausting the air in the coating booth is used for powder coating (see, for example, Patent Documents 1 and 2 below).

[0003]

[0004] Also, Patent Document 3 below describes partitioning the inside of the coating booth by the booth inner wall, transporting the object to be coated to the space partitioned by the booth inner wall, and spraying the powder coating from the coating gun onto the object to be coated within the space.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0006] By the way, when changing the color of the powder coating using the same powder coating equipment, the powder coating accumulated in the paint booth is blown away with an air blower to clean the paint booth before applying the powder coating in the different color.

[0007] During cleaning of a paint booth, powder coatings that adhere to the booth can spread outside through openings and adhere to the painting equipment and its surroundings. If powder coatings remain outside the paint booth after a color change, these remaining coatings can re-enter the booth through the openings, mixing different colored powder coatings and causing painting defects. Therefore, to achieve high-quality powder coating, it is necessary to clean both the paint booth and its exterior during color changes.

[0008] However, conventional powder coating equipment does not take into account the ease of cleaning outside the coating booth, making external cleaning more difficult than internal cleaning, and requiring more time for color changes.

[0009] Reference 3 describes a method of powder coating where the object to be coated is housed in a space formed by partitioning the inside of the paint booth with the booth's inner walls. However, in Reference 3, a reciprocator for moving the paint gun is provided at the top of the paint booth, so the upper end of the booth's inner wall is separated from the top wall of the paint booth. As a result, powder paint may scatter to the outside of the booth's inner wall through the gap between the upper end of the booth's inner wall and the top wall of the paint booth.

[0010] The present invention has been made in view of the above points, and aims to provide a powder coating apparatus that allows for easy cleaning of the inside and outside of the paint booth and shortens the time required for color changes. [Means for solving the problem]

[0011] The present invention includes embodiments shown below.

[0012] [1] A powder coating apparatus comprising a coating chamber for housing an object to be coated, a coating gun for spraying powder coating onto the object to be coated housed in the coating chamber, an air supply unit for supplying air to the coating chamber, and an exhaust unit for discharging air from the coating chamber, wherein the exhaust unit comprises an exhaust chamber located below the coating chamber for receiving air discharged downward from the coating chamber, a plurality of spraying devices for blowing away powder coating accumulated on the bottom surface of the exhaust chamber, and a collection unit for collecting the powder coating blown away by the spraying devices, wherein in a plan view, the plurality of spraying devices are spaced apart in the direction of air injection.

[0013] [2] The 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] The powder coating apparatus according to [1] or [2] above, wherein the recovery unit is located at a position further away from the spraying device in the spraying direction.

[0015] [4] The powder coating apparatus according to [3] above, wherein the plurality of injection devices sequentially inject air at staggered timings from injection devices located far from the recovery unit to injection devices located closer to the recovery unit. [Effects of the Invention]

[0016] According to the present invention, since the paint gun and its support are installed together 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, cleaning during color change operations becomes easier and the time required for color change operations can be shortened. [Brief explanation of the drawing]

[0017] [Figure 1] Cross-sectional view showing the schematic configuration of a powder coating apparatus according to the first embodiment of the present invention. [Figure 2] Cross-sectional view AA in Figure 1 [Figure 3] Plan view showing the schematic configuration of the exhaust chamber of the powder coating apparatus according to the first embodiment of the present invention [Figure 4] Block diagram showing the control configuration of the powder coating apparatus of FIG. 1 [Figure 5] Cross-sectional view showing the schematic configuration of the powder coating apparatus according to the second embodiment of the present invention [Figure 6] Cross-sectional view taken along line B-B of FIG. 5 [Figure 7] Cross-sectional view taken along line C-C of FIG. 6 [Figure 8] Plan view showing the schematic configuration of the exhaust chamber of the powder coating apparatus according to the second embodiment of the present invention [Figure 9] (a) is a cross-sectional view of the powder coating apparatus of Modification Example 1, and (b) is a cross-sectional view of another example of the powder coating apparatus of Modification Example 1 [Figure 10] Cross-sectional view of the powder coating apparatus of Modification Example 3 [Figure 11] Cross-sectional view of the powder coating apparatus showing another example of Modification Example 3 [[ID=K28]]

Mode for Carrying Out the Invention

[0018] 1. First Embodiment Hereinafter, the powder coating apparatus according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4

[0019] (1) Overall Configuration of Powder Coating Apparatus 10 The powder coating apparatus 10 of the present embodiment includes a coating chamber 20, a coating gun 50, a support portion 60, an air supply portion 70, an exhaust portion 80, a purification device 90, and a control device 100, and is a device for spraying a powder coating onto a workpiece W by the coating gun 50 inside the coating chamber 20

[0020] (2) Coating Chamber 20 As shown in Figures 1 and 2, the painting room 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, forming a roughly rectangular parallelepiped space inside which the object to be painted W, the paint gun 50 and the support part 60 are housed.

[0021] In this specification, the front-to-back direction, left-to-right direction, and up-and-down direction refer to the directions when viewed from the front of the entrance 21 of the painting room 20. Furthermore, unless otherwise specified, right, left, up, down, front, and back refer to the position or side when viewed from the front of the entrance 21.

[0022] The painting room 20 is equipped with a workpiece storage section 23 for housing the object to be painted W, a painting machine storage section 24 for housing the support section 60, and a partition wall 25 separating the workpiece storage section 23 and the painting machine storage section 24.

[0023] The workpiece storage area 23 is enclosed by the front wall 20a, rear wall 20b, upper wall 20c, and lower wall 20d that constitute the painting room 20, and a partition wall 25, forming a painting booth space for painting the object to be painted W. The workpiece storage area 23 is connected to the outside of the painting room 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 is provided at the top of the workpiece storage area 23, extending in the front-rear direction from the entrance 21 to the exit 22.

[0024] A hanger 27 for suspending the object to be painted W is attached to the transport rail 26. The hanger 27, together with the transport rail 26 and the drive unit 29 (see Figure 4), constitutes the transport device. The hanger 27 receives driving force from the drive unit 29 and moves in the forward and backward direction along the transport rail 26 to transport the object to be painted W from the entrance 21 to the work storage section 23, moves the object to be painted W in the forward and backward direction from the entrance 21 to the exit 22 within the work storage section 23, and then transports the object to be painted W out of the work storage section 23 from the exit 22.

[0025] Furthermore, a blocking device 28 is provided near the inlet 21 and outlet 22. The blocking device 28 forms an air curtain that suppresses air circulation between the inside and outside of the painting room 20 by blowing air across the inlet 21 and outlet 22.

[0026] The painting machine housing section 24 is a space located on both the left and right sides of the workpiece housing section 23 inside the painting chamber 20, and is enclosed by the front wall 20a, rear wall 20b, upper wall 20c, lower wall 20d, and side walls 20e that constitute the painting chamber 20, and a partition wall 25. The painting machine housing section 24 is provided with a support section 60 for supporting the painting gun 50.

[0027] The partition wall 25 is a wall provided between the workpiece storage section 23 and the painting machine storage section 24, connecting the upper wall 20c and the lower wall 20d, and is provided to partition both storage sections 23 and 24 to the left and right across the entire front-to-back direction of the workpiece storage section 23 and the painting machine storage section 24. The partition wall 25 may be connected to the upper wall 20c and the lower wall 20d without any gaps, or it may be provided with a gap between it and the lower wall 20d.

[0028] Air purified by the purification device 90 flows into the workpiece storage section 23 and the painting machine storage section 24 from the upper wall 20c. The air flowing into the workpiece storage section 23 from the upper wall 20c flows downward within the workpiece storage section 23 and is discharged from the lower wall 20d. The air flowing into the painting machine storage section 24 from the upper wall 20c flows downward within the painting machine storage section 24 and is discharged from the lower wall 20d. It is preferable that the airflow rate of the air flowing through the workpiece storage section 23 is greater than that of the painting machine storage section 24.

[0029] Furthermore, from the viewpoint of preventing powder coating from scattering to the outside of the painting chamber 20 from the inlet 21 and outlet 22 of the painting chamber 20, it is preferable that the air pressure in the workpiece storage section 23 and the painting machine storage section 24 is in a negative pressure state, which is lower than the air pressure outside the painting chamber 20.

[0030] The partition wall 25 is provided with an opening 25a that connects the workpiece storage section 23 and the painting machine storage section 24. The opening 25a of the partition wall 25 is a long, narrow slit in the vertical direction, and a painting gun 50 supported by a support section 60 is inserted through it. At least a portion of the painting gun 50 protrudes from the painting machine storage section 24 through the opening 25a to the workpiece storage section 23 so that the nozzle provided at the tip of the painting gun 50 is positioned in the workpiece storage section 23.

[0031] In this embodiment, painting machine housing sections 24 for housing the support sections 60 are provided on both the left and right sides of the workpiece housing section 23, and the painting guns 50 protrude from both the left and right sides of the workpiece housing section 23. However, the painting machine housing section 24 may be provided on only one side of the workpiece housing section 23, and the painting guns 50 may protrude from only one side of the workpiece housing section 23.

[0032] (3) Paint gun 50 and support part 60 The paint gun 50 is an electrostatic powder coating gun and is connected to a paint supply device 52 (see Figure 4) via piping. The paint gun 50 receives powder coating from the paint supply device 52 and sprays the powder coating onto the object to be coated W within the workpiece housing 23 from its nozzle. The charging method of the paint gun 50 may be either triboelectric or corona-electric.

[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 The painting room 20 is connected to an air supply unit 70 and an exhaust unit 80. Air purified by the purification device 90 is supplied to the painting room 20 through the air supply unit 70, and the air in the painting room 20 is discharged to the outside through the exhaust unit 80. In this embodiment, the air exhausted from the painting room 20 by the exhaust unit 80 is purified by the purification device 90, and then the purified air is supplied to the painting room 20 from the air supply unit 70, so that air circulates between the painting room 20 and the purification device 90.

[0035] Specifically, the air supply unit 70 includes an air supply chamber 72 located above the painting room 20, and an air supply duct 71 connecting the air supply chamber 72 to the air purification device 90. The upper wall 20c that vertically separates the air supply chamber 72 from the painting room 20 is provided with an outlet 73 that communicates the air supply chamber 72 with the workpiece storage area 23, and an outlet 74 that communicates the air supply chamber 72 with the painting machine storage area 24.

[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 workpiece storage section 23 from the outlet 73 and to the painting machine storage section 24 from the outlet 74.

[0037] The exhaust section 80 includes an exhaust chamber 82 located below the painting room 20 and an exhaust duct 81 connecting the exhaust chamber 82 to the purification device 90. The lower wall 20d that vertically separates the exhaust chamber 82 from the painting room 20 is made of a grating floor with numerous holes, and the workpiece storage section 23 and the painting machine storage section 24 of the painting room 20 are in communication with the exhaust chamber 82 through the numerous holes provided in the lower wall 20d.

[0038] When the fan 92 installed in the purification device 90 operates and draws in air from the exhaust duct 81, the air from the workpiece storage section 23 and the painting machine storage section 24 flows into the exhaust chamber 82 through the holes in the lower wall 20d. The air that flows into the exhaust chamber 82 is taken into the purification device 90 through the exhaust duct 81, and after the powder coating is removed in the purification device 90, it is introduced back into the air supply section 70.

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

[0040] For example, the air supply chamber 72 may be provided with a flow straightening material 75 made of a material that causes pressure loss when it passes through, such as a nonwoven fabric. By providing the flow straightening material 75 so as to cover the outlets 73 and 74, the air supplied from the air supply duct 71 to the air supply chamber 72 is pressure-equalized before being supplied to the workpiece storage section 23 and the painting machine storage section 24, forming a uniform airflow without turbulence in the workpiece storage section 23 and the painting machine storage section 24.

[0041] Furthermore, the exhaust chamber 82 may be provided with a flow straightening material 83 made of a flat plate-shaped member made of metal or resin. The flow straightening material 83 is positioned below the lower wall 20d at intervals, and by adjusting the distance from the lower wall 20d and the area facing the lower wall 20d, the flow rate of air discharged from the workpiece storage section 23 and the painting machine storage section 24 is adjusted, and the flow rate of air circulating through the workpiece storage section 23 and the painting machine storage section 24 is adjusted.

[0042] When adjusting the airflow rate through the workpiece storage section 23 and the painting machine storage section 24, it is preferable to adjust the flow rate so that the airflow rate discharged from the workpiece storage section 23 to the exhaust chamber 82 is greater than the airflow rate supplied from the air supply chamber 72 to the workpiece storage section 23, resulting in a negative pressure state where the air pressure in the workpiece storage section 23 is lower than the air pressure outside the painting chamber 20. It is also preferable to provide the rectifiers 75 and 83 so that the airflow rate supplied from the air supply chamber 72 to the workpiece storage section 23 is greater than the airflow rate supplied from the air supply chamber 72 to the painting machine storage section 24, and the airflow rate through the workpiece storage section 23 is greater than that through the painting machine storage section 24.

[0043] As shown in Figures 1 and 3, the exhaust chamber 82 may be provided with a plurality of spraying devices 84 that spray air in a predetermined direction (for example, to the right in this embodiment) and a recovery unit 85. Specifically, in a plan view as shown in Figure 3, the plurality of spraying devices 84 may be spaced apart in the predetermined direction, that is, spaced apart in the direction in which the spraying devices 84 spray air (hereinafter, this direction may also be called the spraying direction). In addition, spraying devices 84 may also be spaced apart in a direction perpendicular to the spraying direction of the spraying devices 84 (in this embodiment, the front-to-back direction). The recovery unit 85 is positioned further away from the spraying devices 84 in the spraying direction and recovers the powder paint blown away by the air sprayed from the spraying devices 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 painting room 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 recovery tank 93 located below the dust collector 91.

[0045] In the recovery tank 93, recyclable powder coatings are sorted from the recovered powder coatings, and the sorted recyclable powder coatings are supplied to the paint supply device 52 via piping.

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

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

[0048] First, the unpainted workpiece W is suspended from a hanger 27 outside the painting room 20, and the workpiece W is transported along the transport rail 26 by the drive device 29 from the entrance 21 of the painting room 20 to the workpiece storage area 23 of the painting room 20.

[0049] The object to be painted W, which has been brought into the workpiece storage section 23, is sprayed with powder paint from the paint gun 50 as it moves from the entrance 21 to the exit 22 within the workpiece 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. At that time, the control device 100 moves the paint gun 50 up and down using the support section 60 as needed.

[0050] Then, when the painting of the object to be painted W is completed, the control device 100 drives the drive device 29 to transport the painted object to be painted W out of the painting room 20 through the exit 22.

[0051] When painting the workpiece W inside the workpiece housing 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 draw air from inside the workpiece housing 23 and the painting machine housing 24 through the exhaust unit 80, thereby discharging the airborne powder paint from the workpiece housing 23 and the painting machine housing 24 along with the air.

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

[0053] The powder paint separated from the air by the dust collector 91 is collected in the recovery tank 93, where foreign matter and other contaminants are removed, and then returned to the paint supply device 52 for reuse in painting.

[0054] In addition to painting the workpiece W, the control device 100 may also drive the fan 92 of the purification device 90 to circulate air in the workpiece 23 and the painting machine 24 when unpainted workpieces W are brought into the workpiece storage unit 23 or when painted workpieces W are removed from the workpiece storage unit 23 to the outside of the painting chamber 20. Furthermore, when unpainted workpieces W are brought in or painted workpieces W are removed, the rotation speed of the fan 92 may be reduced compared to when painting the workpieces W, or the fan 92 may be stopped.

[0055] Furthermore, during color change operations or cleaning of the painting room 20, the control device 100 drives the fan 92 of the purification device 90 to draw air from the workpiece storage area 23 and the painting machine storage area 24 through the exhaust area 80, while simultaneously blowing away any powder paint accumulated in the workpiece storage area 23 and the painting machine storage area 24 with an air blower. As a result, the powder paint blown away by the air blower is discharged from the workpiece storage area 23 and the painting machine storage area 24 along with the air and recovered by the purification device 90.

[0056] In this case, the control device 100 may inject air from the injection device 84. Specifically, the control device 100 injects air sequentially and at different timings from the injection device 84 located far from the recovery unit 85 to the injection device 84 located closer to the recovery unit 85, blowing the powder paint accumulated at the bottom of the exhaust chamber 82 in the direction of injection from the injection device 84 and sending it to the recovery unit 85.

[0057] In this embodiment, the powdered paint recovered in the recovery tank 93 is supplied to the paint supply device 52 for reuse, but the recovered powdered paint may be discarded instead of being reused.

[0058] (7) Effects In the powder coating apparatus 10 of this embodiment, a coating gun 50 and a support unit 60 are provided in a coating chamber 20 to which purified air is supplied, connected to an air supply unit 70 and an exhaust unit 80. There is no opening for inserting the coating gun 50 in the wall separating the coating chamber 20 from the outside. Therefore, foreign matter is less likely to enter the workpiece storage unit 23 from outside the coating chamber 20, enabling high-quality powder coating.

[0059] Furthermore, in the powder coating apparatus 10 of this embodiment, the exhaust unit 80 is connected not only to the workpiece housing unit 23 where the workpiece W is coated, but also to the coating machine housing unit 24, which is equipped with a support unit 60 for supporting the coating gun 50, allowing the internal air of the coating machine housing unit 24 to be discharged.

[0060] In this type of powder coating apparatus 10, during color change operations or cleaning of the coating chamber 20, the accumulated powder paint can be blown away not only from the workpiece storage section 23 but also from the coating machine storage section 24 using an air blower, preventing the powder paint from spreading outside the coating chamber 20 and allowing it to be recovered from the exhaust section 80. Therefore, cleaning during color change operations becomes easier and the time required for color change operations can be shortened.

[0061] In the powder coating apparatus 10, a partition wall 25 separates the workpiece storage section 23 from the coating machine storage section 24. By positioning the nozzle of the coating gun 50 into the workpiece storage section 23 through an opening 25a in the partition wall 25, the air flowing through the workpiece storage section 23 is less affected by the support section 60 and other components, and turbulence is less likely to occur in the workpiece storage section 23. As a result, high-quality powder coating can be performed in which the powder coating is uniformly sprayed onto the object to be coated W.

[0062] In the powder coating apparatus 10, by providing rectifiers 75 and 83 in the air supply chamber 72 and exhaust chamber 82, it is possible to control the airflow rate between the workpiece storage section 23 and the coating machine storage section 24, or to generate a uniform airflow in the workpiece storage section 23 and the coating machine storage section 24.

[0063] In the powder coating apparatus 10, when air is circulated so that powder coating is removed from the air discharged from the coating chamber 20 before returning it to the coating chamber 20, it becomes more difficult for air to flow into the coating chamber 20 from the outside, making it easier to maintain a constant temperature and humidity environment inside the coating chamber 20. As a result, the coating environment is more stable, and the quality of the coating can be improved. When an operator works in the coating chamber 20, it becomes easier to control the environment inside the coating chamber 20 to create a comfortable environment for the operator to work in.

[0064] In the powder coating apparatus 10, by providing multiple sprayers 84 in the exhaust chamber 82 at intervals in the spraying direction of the sprayers 84, the powder coating accumulated at the bottom of the exhaust chamber 82 can be blown away and collected in the recovery section 85.

[0065] In the powder coating apparatus 10, by providing shut-off devices 28 at the inlet 21 and outlet 22 of the coating chamber 20, it is possible to suppress coating defects caused by foreign matter entering the coating chamber 20 from the outside, and the diffusion of powder coating to the outside of the coating chamber 20.

[0066] In the powder coating apparatus 10, when the air supply unit 70 supplies air from the upper side of the coating chamber 20 and the exhaust unit 80 discharges air from the lower side of the coating chamber 20, a uniform airflow from the upper wall 20c to the lower wall 20d is easily generated within the workpiece storage unit 23, enabling high-quality powder coating in which the powder coating is uniformly sprayed onto the object to be coated W.

[0067] In this embodiment, the air pressure in the workpiece storage section 23 is adjusted to be a negative pressure state, which is lower than the air pressure outside the painting chamber 20. This prevents the powder coating sprayed into the workpiece storage section 23 from scattering to the outside of the painting chamber 20 through the inlet 21 and outlet 22.

[0068] In this embodiment, the airflow rate supplied from the air supply chamber 72 to the workpiece storage section 23 is greater than the airflow rate supplied from the air supply chamber 72 to the painting machine storage section 24, so that the powder coating sprayed into the workpiece storage section 23 can be quickly discharged to the exhaust chamber 82.

[0069] 2. Second Embodiment The second embodiment will be described primarily with reference to Figures 5 to 8. In this embodiment, elements that are the same as or corresponding to those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are 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 includes an exhaust area 231 and an air supply area 232.

[0071] (1) Painting room 20 The painting chamber 20 has an exhaust area 231 in the front-to-back center of the workpiece housing section 23 for spraying powder coating onto the workpiece W to paint it, and supply air areas 232 are provided on both the front-to-back sides of the exhaust area 231. The supply air areas 232 are connected to the outside of the painting chamber 20 via an inlet 21 provided in the front wall 20a and an outlet 22 provided in the rear wall 20b.

[0072] A slit-shaped opening 25a is provided in the portion of the partition wall 25 (hereinafter sometimes referred to as the first partition wall 25) that separates the workpiece storage section 23 and the painting machine storage section 24, facing the exhaust area 231. A painting gun 50 supported by a support section 60 is inserted through the opening 25a of the first partition wall 25, and at least a part of the painting gun 50 protrudes from the painting machine storage section 24 through the opening 25a into the exhaust area 231, such that the nozzle provided at the tip of the painting gun 50 is positioned in the exhaust area 231.

[0073] The workpiece storage section 23 has two second partition walls 233 spaced apart in the front-rear direction. The second partition walls 233 are positioned opposite the front wall 20a and rear wall 20b of the painting room 20 in the front-rear direction, dividing the workpiece storage section 23 into front-rear and rear sections. An exhaust region 231 is formed between the two second partition walls 233. An air supply region 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 opposite the inlet 21 of the front wall 20a and the outlet 22 of the rear wall 20b in the front-rear direction. The exhaust region 231 communicates with the air supply region 232 via the communication ports 234 provided in the second partition walls 233.

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

[0075] The transport rail 26, located above the workpiece storage section 23, extends in the front-rear direction from the entrance 21 of the front wall 20a through the communication opening 234 of the second partition wall 233 to the exit 22 of the rear wall 20b. The hanger 27, attached to the transport rail 26, receives driving force from the drive unit 29 and moves along the transport rail 26 in the forward and backward directions. As a result, the hanger 27 transports the object to be painted W from the inlet 21 to the work storage section 23, moves the object to be painted W through the air supply area 232 on the inlet 21 side, the exhaust area 231, and the air supply area 232 on the outlet 22 side in sequence to the outlet 22, and then transports the object to be painted W out of the work storage section 23 from the outlet 22.

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

[0077] Specifically, the air supply unit 270 includes an air supply chamber 272 located above the painting chamber 20, and an air supply duct 271 connecting the air supply chamber 272 to the air purification device 90. The upper wall 20c that vertically separates the air supply chamber 272 from the painting chamber 20 is provided with an outlet 273 (see Figure 7) that communicates the air supply chamber 272 with the air supply area 232 of the workpiece storage unit 23, and an outlet 274 (see Figure 5) that communicates the air supply chamber 272 with the painting machine storage unit 24.

[0078] The exhaust section 280 includes an exhaust chamber 282 located below the painting chamber 20 and an exhaust duct 281 connecting the exhaust chamber 282 to the purification device 90. In this embodiment, as shown in Figure 8, the exhaust chamber 282 is located below the exhaust area 231 of the painting chamber 20. The lower wall 20d that vertically separates the exhaust chamber 282 from the exhaust area 231 of the workpiece storage section 23 is provided with an intake port 286 (see Figures 5 and 7) that communicates with the exhaust chamber 282 and the exhaust area 231.

[0079] Furthermore, the lower wall 20d provided in the exhaust area 231 of the workpiece storage section 23 consists of a grating floor with numerous holes, and these numerous holes function as suction ports 286 that connect the exhaust area 231 of the workpiece storage section 23 with 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 and draws in air from the exhaust duct 281, the air in the exhaust area 231 of the workpiece storage section 23 flows into the exhaust chamber 282 through the intake port 286 in the lower wall 20d. The air that flows into the exhaust chamber 282 is taken into the purification device 90 through the exhaust duct 281, where the powder coating is removed and the air is 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 from the outlet 273 to the air supply area 232 of the workpiece housing section 23, and also supplied from the outlet 274 to the painting machine housing section 24.

[0082] In this embodiment, the operation of the fan 92 provided in the purification device 90 causes the air in the exhaust region 231 of the workpiece storage section 23 to be discharged to the exhaust section 280, and the air in the supply region 232 and the painting machine storage section 24 flows into the exhaust region 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 region 231 to the exhaust section 280. However, some of the air in the supply region 232 and the painting machine storage section 24 may be discharged to the exhaust section 280 from the intake port provided in the lower wall 20d.

[0083] When a portion of the air in the air supply area 232 and the painting machine housing 24 is discharged to the exhaust section 280 through an intake port provided on the lower wall 20d, the flow rate of the air discharged from the air supply area 232 and the painting machine housing 24 of the workpiece housing 23 to the exhaust section 280 is set to be less than the flow rate of the air discharged from the exhaust area 231 of the workpiece housing 23 to the exhaust section 280.

[0084] In this embodiment, the operation of the fan 92 provided in the purification device 90 supplies air from the air supply unit 270 to the air supply area 232 and the paint machine housing 24, and air is supplied to the exhaust area 231 from the air supply area 232 and the paint machine housing 24. However, a portion of the air from the air supply unit 270 may also be supplied to the exhaust area 231.

[0085] When a portion of the air from the air intake section 270 is supplied to the exhaust section 231, the flow rate of the air supplied from the air intake section 270 to the exhaust section 231 is less than the flow rate of the air supplied from the air intake section 270 to the air intake section 232 and the painting machine housing section 24.

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

[0087] Due to the differential pressure between the exhaust region 231 and the supply region 232, the air supplied to the supply region 232 of the workpiece housing 23 flows into the exhaust region 231 through the communication port 234 provided in the second partition wall 233. Also, due to the differential pressure between the exhaust region 231 and the painting machine housing 24, the air supplied to the painting machine housing 24 flows into the exhaust region 231 through the opening 25a provided in the first partition wall 25.

[0088] Air flowing from the air supply area 232 and the painting machine housing 24 into the exhaust area 231 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 coating is removed in the purification device 90, the air is introduced back into the air supply area 70.

[0089] Furthermore, it is preferable that the flow rate of air supplied to the exhaust region 231 (in this embodiment, the flow rate of air flowing from the air supply region 232 and the painting machine housing 24 into the exhaust region 231) is less than the flow rate of air discharged from the exhaust region 231 to the exhaust chamber 282 of the exhaust unit 280, and that the air pressure in the exhaust region 231 is lower than the air pressure outside the painting chamber 20, creating a negative pressure state. By creating a negative pressure state in the exhaust region 231, powder coatings that do not adhere to the object to be painted W and remain in the exhaust region 231 are less likely to diffuse to the outside of the exhaust region 231.

[0090] Furthermore, it is preferable that the airflow rate supplied from the air intake unit 270 to the air intake area 232 is greater than the airflow rate supplied from the air intake unit 270 to the painting machine housing 24. By increasing the airflow rate supplied to the air intake area 232, powder coatings that do not adhere to the object to be painted W and remain in the exhaust area 231 are less likely to diffuse into the air intake area 232.

[0091] Furthermore, it is preferable that the air pressure in the air supply area 232 be adjusted to a positive pressure state that is higher than the air pressure outside the painting chamber 20. This helps to suppress the entry of foreign matter from the outside into the painting chamber 20.

[0092] (3) Operation of the powder coating apparatus 210 The operation of the powder coating apparatus 210 of this embodiment will now 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 storage area 23 and the painting machine storage area 24. The air supplied to the air supply area 232 and the painting machine storage area 24 flows into the exhaust area 231 through 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, with the fan 92 installed in the purification device 90 circulating air in the air supply area 232, the painting machine housing 24, and the exhaust area 231, the unpainted workpiece W suspended from the hanger 27 is moved from the inlet 21 of the painting chamber 20 to the workpiece housing 23. The unpainted workpiece W, which has been moved to the workpiece storage area 23, is transported to the exhaust area 231 through the intake air area 232 on the inlet side.

[0095] Then, with air flowing through the air intake area 232, the paint machine 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 onto the object to be painted W that has been transported from the paint gun 50 into the exhaust area 231. At this time, the control device 100 moves the paint gun 50 up and down using the support unit 60 as needed.

[0096] When powder coating is applied to the object to be painted W in the exhaust region 231 of the workpiece housing 23, some of the powder coating discharged from the paint gun 50 does not adhere to the object to be painted W and remains in the exhaust region 231.

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

[0098] Furthermore, the operation of the fan 92 of the purification device 90 causes the air pressure in the supply air area 232 of the workpiece storage area 23 and the painting machine storage area 24 to become higher than the air pressure in the exhaust air area 231 of the workpiece storage area 23, creating a differential pressure between the exhaust air area 231 and the supply air area 232, and between the exhaust air area 231 and the painting machine storage area 24.

[0099] This differential pressure causes the air supplied to the air supply area 232 of the workpiece housing 23 to flow into the exhaust area 231 through the communication port 234 provided in the second partition wall 233. This prevents powder coating that did not adhere to the workpiece W from diffusing from the communication port 234 through the air supply area 232 to the outside of the painting chamber 20 through the inlet 21 and outlet 22. Additionally, the air supplied to the painting machine housing 24 flows into the exhaust area 231 through the opening 25a provided in the first partition wall 25. This prevents powder coating that did not adhere to the workpiece W from entering the painting machine housing 24 through the opening 25a in the first partition wall 25.

[0100] When the painting of the object to be painted W is completed, the control device 100 operates the fan 92 provided in the purification device 90 and drives the drive device 29 to transport the painted object to be painted W out of the painting room 20 through the communication opening 234 of the second partition wall 233 and through the outlet side supply air area 232. If necessary, simultaneously with the transport of the painted object to be painted W, an unpainted object to be painted W is transported into the exhaust area 231 and powder coating is sprayed onto the next object to be painted W.

[0101] In this embodiment, the fan 92 provided in the purification device 90 was operated to circulate air to the air supply area 232, the painting machine housing 24, and the exhaust area 231, not only during the painting of the workpiece W, but also during the loading of unpainted workpieces W and the unloading of painted workpieces W. However, the fan 92 may be stopped or its rotation speed reduced compared to during the painting of the workpiece W.

[0102] (4) Effects In the powder coating apparatus 210 of this embodiment, the workpiece storage area 23 is divided into an exhaust area 231 and an air supply area 232, and the air supply area 232 and the coating machine storage area 24 are set to have a higher air pressure than the exhaust area 231. Therefore, it is possible to suppress the diffusion of powder coating to the outside of the coating chamber 20 without installing a blocking device 28 such as an air curtain near the inlet 21 and outlet 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 supply area 232, which prevents powder coating that did not adhere to the object to be coated W from diffusing from the exhaust area 231 to the supply area 232.

[0104] 3. Example of changes Next, examples of modifications will be described. Various modifications can be made to the above embodiments without departing from the spirit of the invention. Several examples of modifications will be described below, but any one of the examples of modifications described below may be applied to the above embodiments, or any two or more of the examples of modifications described below may be applied in combination. In addition to the examples of modifications below, various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Note that components with the same configuration as those in the above embodiments will be denoted by the same reference numerals, and their configurations will not be described.

[0105] (1) Example of change 1 In the first embodiment described above, the air supply unit 70 supplied air from the top of the painting chamber 20 and the exhaust unit 80 discharged air from the bottom of the painting chamber 20. However, as shown in Figure 9(a), the air supply unit 170 may supply air from the top of the painting chamber 20 and the exhaust unit 180 may discharge air from one side of the painting chamber 20 in the front-rear direction. Alternatively, as shown in Figure 9(b), the air supply unit 270 may supply air from one side of the painting chamber 20 in the front-rear direction and the exhaust unit 190 may discharge air from the other side of the painting chamber 20 in the front-rear direction.

[0106] (2) Example of change 2 In the first and second embodiments described above, the air exhausted from the painting room 20 was purified by the purification device 90, and then the purified air was circulated between the painting room 20 and the purification device 90 so that it would return to the painting room 20. However, the air exhausted from the painting room 20 may be purified by the purification device and then released to the outside of the painting room 20, and the air from outside the painting room 20 may be supplied to the painting room 20 after foreign matter and debris have been removed by a filter such as nonwoven fabric.

[0107] (3) Example of change 3 In the first and second embodiments described above, the painting chamber 20 is provided with a workpiece storage section 23 and a painting machine storage section 24. However, as shown in Figure 10, a work area 130 may be provided in addition to the workpiece storage section 23 and the painting machine storage section 24.

[0108] The work area 130 is located, for example, behind the work storage area 23 and the painting machine storage area 24 within the painting chamber 120 (on the exit 22 side), and the workpieces W that have been painted by spraying powder coating in the work storage area 23 are transported in by hangers 27.

[0109] In this modified example of the powder coating apparatus 140, air purified by the purification device 90 is supplied from the air supply units 70 and 270 to the workpiece storage unit 23, the coating machine storage unit 24, and the work area 130. The air from the workpiece storage unit 23, the coating machine storage unit 24, and the work area 130 is exhausted to the exhaust unit 80 and sent to the purification device 90. The purification device 90 removes the powder coating before supplying it to the workpiece storage unit 23, the coating machine storage unit 24, and the work area 130 via the air supply units 70 and 270.

[0110] In this modified example of the powder coating apparatus 140, an operator can inspect the coated object W within the work area 130 and repaint any areas with coating defects. Furthermore, when a work area 130 where an operator works is provided in the coating room 20, as in this modified example, it is preferable to install air conditioners in the work area 130 and the air supply units 70 and 270 to ensure a comfortable working environment.

[0111] In this modified example, the work area 130 is located inside the painting room 20. However, as shown in Figure 11, the work area 150 may be located behind the painting room 20 at a distance, and the work area 150 and the painting room 20 may be connected by a connecting part 160.

[0112] Specifically, the work section 150 includes a front wall 150a with an entrance 151, a rear wall 150b with 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 located in the front wall 150a of the work area 150 is connected to the exit 22 of the painting room 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 painting room 20 to the front wall 150a of the work area 150.

[0114] The object to be painted W, which is removed from the exit 22 of the painting room 20 by the hanger 27, passes through the connecting section 160, is brought into the work area 150 from the entrance 151 of the front wall 150a, passes through the work area 150, and is removed from the exit 152 of the rear wall 150b.

[0115] (4) Example of change 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 workpiece housing section 23, and an air outlet 274 communicating with the air supply chamber 272 and the painting machine housing section 24 are provided on 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 on 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 airflow is generated in the exhaust area 231 that flows downward from the upper wall 20c to the lower wall 20d, enabling high-quality powder coating in which the powder coating is uniformly sprayed onto the object to be coated W.

[0117] Furthermore, when an air outlet is provided to supply air from the air intake chamber 272 to the exhaust area 231, as in this modified example, it is preferable that the flow rate of air supplied from the air intake chamber 272 to the exhaust area 231 through the air outlet is less than the flow rate of air supplied from the air intake chamber 272 to the air intake area 232, and is also preferable that it is less than the flow rate of air supplied from the air intake chamber 272 to the painting machine housing 24.

[0118] Furthermore, when an air outlet is provided to supply air from the air intake chamber 272 to the exhaust area 231, as in this modified example, it is preferable that the total flow rate of air supplied to the exhaust area 231, that is, the sum of the flow rate of air flowing from the air intake area 232 and the painting machine housing 24 into the exhaust area 231 and the flow rate of air supplied from the air intake 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 unit 280, resulting in a negative pressure state where the air pressure in the exhaust area 231 is lower than the air pressure outside the painting room 20.

[0119] Furthermore, in this modified example, the airflow rate supplied from the air intake chamber 272 to the exhaust region 231 may be greater on the paint gun 50 side than on the communication port 234 side, and greater in the central part of the exhaust region 231 in the front-to-back direction than at both ends in the front-to-back direction. This makes it less likely to obstruct the airflow from the air intake region 232 through the communication port 234 to the exhaust region 231.

[0120] (5) Example of change 5 In the second embodiment described above, a suction port 286 communicating with the exhaust chamber 282 and the exhaust area 231 of the workpiece housing section 23 is provided on the lower wall 20d. However, in addition to the suction port 286, a suction port communicating with the exhaust chamber 282 and the supply air area 232, and a suction port communicating with the exhaust chamber 282 and the painting machine housing section 24 may also be provided on the lower wall 20d.

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

[0122] As shown in this modification example, by providing an intake port that communicates the exhaust chamber 282 with the air supply area 232 and the paint machine housing 24, a portion of the air in the air supply area 232 and the paint machine housing 24 is discharged into the exhaust chamber 282 through the intake port provided in the lower wall 20d. Therefore, even if powder paint that does not adhere to the object to be painted W is scattered into the air supply area 232 or the paint machine housing 24, it will be more easily discharged into the exhaust chamber 282 without accumulating in the air supply area 232 or the paint machine housing 24.

[0123] (6) Example of change 6 In the second embodiment described above, a second partition wall 233 is provided between the exhaust region 231 and the supply region 232 of the workpiece housing 23. However, if the air pressure in the supply region 232 and the painting machine housing 24 is higher than the air pressure in the exhaust region 231, the second partition wall 233 does not need to be provided between the exhaust region 231 and the supply region 232. [Explanation of Symbols]

[0124] 10...Powder coating apparatus, 20...Coating room, 21...Entrance, 22...Exit, 23...Workpiece storage area, 2 4...Painting machine housing, 25...Partition wall, 25a...Opening, 26...Transport rail, 27...Hanger, 28...Shut-off device, 29...Drive device, 50...Paint gun, 51...Nozzle, 52...Paint supply device Placement, 60...Support part, 70...Air supply part, 71...Air supply duct, 72...Air supply chamber, 73...Outlet, 7 4...Air outlet, 75...Flow straightener, 80...Exhaust section, 81...Exhaust duct, 82...Exhaust chamber, 83...Straightener Flow material, 84...Injection device, 85...Recovery unit, 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 opening, 270...Air supply section, 271...Air supply duct T, 272...Air intake chamber, 273...Air outlet, 274...Air outlet, 280...Exhaust section, 281...Exhaust Duct, 282... Exhaust chamber, 285... Recovery section, 286... Intake port, W... Object to be painted

Claims

1. A painting room for housing the objects to be painted, A painting gun for spraying powder coating onto an object to be painted, which is housed in the aforementioned painting chamber, An air supply unit that supplies air to the aforementioned painting chamber, A powder coating apparatus comprising an exhaust unit for discharging air from the coating chamber, The powder coating apparatus comprises an exhaust section located below the coating chamber and receiving air discharged downward from the coating chamber, a plurality of spraying devices for blowing away powder coating accumulated on the bottom surface of the exhaust chamber, and a collection section for collecting the powder coating blown away by the spraying devices, wherein, in a plan view, the plurality of spraying devices are spaced apart in the direction of air injection.

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. The powder coating apparatus according to claim 1, wherein the recovery unit is located at a position further away from the spraying device in the spraying direction.

4. The powder coating apparatus according to claim 3, wherein the plurality of injection devices inject air sequentially with staggered timings, from the injection device located far from the recovery unit to the injection device located closer to the recovery unit.

Images