Hopper for cleaning paint sprayer

Abstract

Provided is a hopper for washing a painting machine, which, despite being small-sized, makes ejected waste paint less likely to splash back to the rotary spray head. A hopper 21 for washing a painting machine according to the present invention comprises a hopper body 23 that has an upper opening part 23a in an upper end part and a lower opening part 23b in a bottom part 42, and a top lid 24 that covers the lower opening part 23b. The top lid 24 has an insertion hole 22 that allows a rotary spray head 6, rotatably provided on a painting machine 4, to be inserted into the hopper body 23. An opening diameter D1 of the insertion hole 22 is larger than a radius D2 of the hopper body 23. On the back surface side of the top lid 24, a plurality of protrusions 44, 45 are provided in a projecting manner to prevent the waste paint ejected by the rotary spray head 6 from splashing back. The plurality of protrusions 44, 45 have different inner diameters and each surround the insertion hole 22. Selected drawing: FIG. 2

Description

[Technical Field]

[0001] The present invention relates to a sprayer cleaning hopper used when cleaning the rotary atomizing head of a sprayer. [Background technology]

[0002] Generally, painting robots are primarily used to paint automobile bodies and other objects. These painting robots are installed in a painting booth and are equipped with an arm that bends, stretches, and rotates when painting the object, and a paint sprayer attached to the end of the arm. The paint sprayer is equipped with a bell-shaped rotary atomizing head. In addition to painting the object, the painting robot also sprays excess paint into a waste paint collection container during color changes.

[0003] One such waste paint collection container that has been proposed is a sprayer cleaning hopper 51 shown in Figure 6(a). This sprayer cleaning hopper 51 includes a cylindrical hopper body 53 having an opening 52 at its upper end, and a top lid 54 that covers the opening 52. The top lid 54 is provided with an insertion hole 55. A rotary atomizing head 56 is inserted into the hopper body 53 through the insertion hole 55, and in this state, cleaning is performed while discharging excess paint. This allows the excess paint to be collected in the hopper 51 as waste liquid. Similar types of sprayer cleaning hoppers are also disclosed in Patent Documents 1 and 2, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-334574 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-34635 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for smaller coating booths and their component parts, and a corresponding demand for smaller hoppers 51. For example, currently, hoppers 51 with an inner diameter of approximately 300 mm are used (see FIG. 7(a)). It would be desirable to reduce this diameter to approximately 200 mm (see FIG. 7(b)). However, simply reducing the diameter of the hopper 51 while maintaining the conventional configuration would shorten the length from the insertion hole 55 to the inner surface of the hopper body 53, resulting in significant rebound of the waste paint (see arrow A1 in the figure). In other words, the waste paint discharged from the rotary atomizing head 56 creeps up the inner surface of the hopper body 53 and reaches the backside of the top cover 54. If the waste paint reaches the insertion hole 55, it rebounds and adheres to the periphery of the rotary atomizing head 56. This creates a problem of the tip of the sprayer becoming easily soiled. Furthermore, when the inner diameter is about 200 mm, the internal space of the hopper 51 becomes narrower, and the amount of air that escapes through the insertion hole 55 during cleaning increases. As a result, there is also the problem that particulate waste paint is more likely to leak out through the insertion hole 55.

[0006] The present invention has been made in view of the above-mentioned problems, and its object is to provide a hopper for cleaning a sprayer that is compact but does not easily cause discharged waste paint to rebound toward the rotary atomizing head. [Means for solving the problem]

[0007] In order to solve the above problems, the invention described in Means 1 is a sprayer cleaning hopper comprising: a hopper body having an upper opening at its top end and a lower opening at its bottom; and an upper lid that covers the upper opening, wherein the upper lid has an insertion hole through which a rotary atomizing head rotatably mounted on the sprayer can be inserted into the hopper body, the opening diameter of the insertion hole being larger than the radius of the hopper body, and the back side of the upper lid is provided with a plurality of ridges that prevent the waste paint discharged by the rotary atomizing head from bouncing back, and the plurality of ridges have different inner diameters and each surrounds the insertion hole.

[0008] Therefore, according to the invention described in Means 1, the opening diameter of the insertion hole is larger than the radius of the hopper body, allowing for a compact hopper. Furthermore, the presence of multiple protrusions protruding from the back side of the top cover prevents the waste paint discharged from the rotary atomizing head from bouncing back. In this case, the inner protrusions, each with a different inner diameter and surrounding the insertion hole, mainly block paint particles in the mist-like waste paint. Furthermore, the outer protrusions mainly block components other than air in the waste paint that have crept up along the inner circumferential surface of the hopper body. This allows for a sprayer cleaning hopper in which the discharged waste paint is less likely to bounce back toward the rotary atomizing head.

[0009] The invention described in means 2 is characterized in that in means 1, the protrusion amount of the inner ridge is equal to or smaller than the protrusion amount of the outer ridge.

[0010] The invention described in Means 3 is characterized in that in Means 2, the plurality of ridges are first ridges provided on the rear opening edge of the insertion hole and second ridges provided outside the first ridges, and the first ridges mainly block paint particles in the waste paint in mist form, and the second ridges mainly block components other than air in the waste paint that have creeped up along the inner surface of the hopper body.

[0011] The invention described in means 4 is characterized in that in means 3, the distance between the second ridge and the first ridge is smaller than the distance between the second ridge and the inner surface of the hopper body.

[0012] The invention described in means 5 is summarized as being in means 3 or 4, in that the protruding amount of the first ridge is equal to or smaller than the insertion amount of the rotary atomizing head. [Effects of the Invention]

[0013] As described above in detail, according to the inventions described in claims 1 to 5, it is possible to provide a hopper for cleaning a sprayer that is small in size but does not allow discharged waste paint to easily rebound toward the rotary atomizing head. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram illustrating a state in which a sprayer cleaning hopper according to an embodiment of the present invention is used; [Figure 2] 1 is a schematic cross-sectional view showing a hopper for cleaning a coating machine according to an embodiment; [Figure 3] FIG. 1(a) is a schematic diagram illustrating the flow of waste paint during the cup cleaning operation of a conventional sprayer cleaning hopper without protrusions, and FIG. 1(b) is a schematic diagram illustrating the flow of waste paint during the cup cleaning operation of an embodiment of a sprayer cleaning hopper with two protrusions. [Figure 4] (a) is a schematic diagram illustrating the flow of waste paint during the back-side cup cleaning operation of a conventional sprayer cleaning hopper without protrusions, and (b) is a schematic diagram illustrating the flow of waste paint during the back-side cup cleaning operation of an embodiment of a sprayer cleaning hopper with two protrusions. [Figure 5] FIG. 10 is a schematic cross-sectional view showing a hopper for cleaning a sprayer according to another embodiment. [Figure 6] FIG. 10 is a partial schematic cross-sectional view showing a hopper for cleaning a sprayer according to another embodiment. [Figure 7] (a) and (b) are schematic diagrams showing a conventional hopper for cleaning a sprayer. BEST MODE FOR CARRYING OUT THE INVENTION

[0015] An open-type sprayer cleaning hopper 21 according to one embodiment of the present invention will now be described in detail with reference to FIGS.

[0016] As shown in FIG. 1 , the sprayer cleaning hopper 21 of this embodiment constitutes part of a sprayer cleaning mechanism for cleaning a sprayer 4 attached to a painting robot 3. The painting robot 3 is an articulated robot used to paint a workpiece (not shown), such as an automobile body. The painting robot 3 includes an arm 2 that bends, stretches, and rotates when painting the workpiece, and a sprayer 4 attached to the tip of the arm 2. The height and paint spray direction of the sprayer 4 are changed by bending, stretching, and rotating the arm 2. The arm 2 includes multiple motors (not shown) for moving multiple joints. These motors are driven and controlled based on control signals from a controller 9.

[0017] The sprayer 4 comprises a substantially cylindrical sprayer body 5 and a bell-shaped rotary atomizing head 6. The sprayer body 5 comprises a paint container (not shown) filled with paint, and a paint supply mechanism (not shown) that supplies the paint from the paint container to the rotary atomizing head 6. The rotary atomizing head 6 is attached to the sprayer body 5 and rotated by a motor for rotating the atomizing head provided within the sprayer body 5. When the rotary atomizing head 6 rotates, the paint supplied by the paint supply mechanism is scattered toward the outer periphery by centrifugal force and atomized. The paint supply mechanism and the motor for rotating the atomizing head are driven and controlled based on control signals from a controller 9. The front portion 7 of the rotary atomizing head 6 has a tapered surface whose outer diameter increases toward the front end.

[0018] As shown in FIG. 1, the sprayer cleaning hopper 21 is provided separately from the sprayer 4 and near the painting robot 3. The sprayer cleaning hopper 21 has the function of collecting cleaning liquid such as water and the function of collecting waste paint blown off from the sprayer 4 during color changes. As shown in FIG. 2, the sprayer cleaning hopper 21 includes a substantially cylindrical hopper body 23 and a top cover 24 that is substantially circular in top view. While the materials forming the hopper body 23 and the top cover 24 are not limited, in this embodiment, the hopper body 23 is made of stainless steel, and the top cover 24 is made of a synthetic resin that has excellent heat resistance, mechanical strength, and the like. The hopper body 23 has an upper opening 23a at its upper end and a lower opening 23b at its bottom 42.

[0019] The top cover 24 has a diameter substantially equal to the outer diameter of the hopper body 23, and is attached to the hopper body 23 so as to cover the upper opening 23a. Specifically, the top cover 24 is attached to the hopper body 23 by overlapping the outer periphery of the top cover 24 with a flange formed on the hopper body 23 and fastening them with tapped bolts. In other words, the top cover 24 of this embodiment is detachably attached to the hopper body 23. In addition, a circular insertion hole 22 is provided in the center of the top cover 24, through which the rotary atomizing head 6 can be inserted into the hopper body 23.

[0020] The dimensions of each part of the hopper body 23 are not particularly limited, but for example, the inner diameter is set to approximately 150 mm to 250 mm, and is set to 200 mm in this embodiment. That is, in this embodiment, the radius D2 of the hopper body 23 is set to 100 mm. The opening diameter D1 of the insertion hole 22 is set to a size that leaves a gap of 10 mm to 50 mm between it and the inserted rotary atomizing head 6. In this embodiment (a type having two ridges (described later)), the inner diameter is set to 120 mm so that a gap of approximately 10 mm is left. Therefore, in this embodiment, the opening diameter D1 of the insertion hole 22 is somewhat larger than the radius D2 of the hopper body 23.

[0021] An in-cup cleaning nozzle (not shown) is provided inside the sprayer 4 to spray cleaning liquid to clean the inside of the rotary atomizing head 6. The in-cup cleaning nozzle is provided at the downstream end of a cleaning liquid supply path 18 branching off from the main cleaning liquid supply path. A cleaning liquid container 14 filled with cleaning liquid and a pump 15 for pressure-feeding the cleaning liquid in the cleaning liquid container 14 are provided upstream of the main cleaning liquid supply path 18. A regulator 17a and a valve 17b are provided upstream of the branched cleaning liquid supply path 18. The pump 15, regulator 17a, and valve 17b are driven based on control signals from the controller 9.

[0022] A cup back cleaning nozzle 11, which sprays cleaning liquid to clean the rear surface of the rotary atomizing head 6, is fixed to the top surface of the upper cover 24 via a mounting bracket 12 or the like. The cup back cleaning nozzle 11 is located near the open edge of the insertion hole 22 on the outside of the sprayer cleaning hopper 21. As shown in FIG. 1 , the cup back cleaning nozzle 11 is provided at the downstream end of a cleaning liquid supply path 13 branching off from the main cleaning liquid supply path. A regulator 19a and a valve 19b are provided upstream of the branched cleaning liquid supply path 13. The pump 15, regulator 19a, and valve 19b are driven based on control signals from the controller 9. The cup back cleaning nozzle 11 is equipped with two cleaning liquid spray pipes 16 extending in the same direction. Each cleaning liquid spray pipe 16 is positioned diagonally downward with its tip facing the rear surface of the rotary atomizing head 6.

[0023] 2, the hopper body 23 constituting the coater cleaning hopper 21 has a height (dimension in the axial direction) set to approximately 200 mm to 400 mm. A drain passage 49 is provided on the outer periphery of the bottom 42 of the hopper body 23 for discharging waste liquid accumulated in the coater cleaning hopper 21 to the outside. A valve (not shown) that is normally closed is provided midway along the drain passage 49.

[0024] As shown in FIG. 2, the top cover 24 of the sprayer cleaning hopper 21 has two ridges 44, 45. The two ridges 44, 45 are structures for preventing the splashback of waste paint discharged from the rotary atomizing head 6, and both protrude from the back side of the top cover 24. In this embodiment, the ridges 44, 45 are thin plate-like structures (baffle plates). The two ridges 44, 45 have different inner diameters and each surrounds the entire circumference of the insertion hole 22. For ease of explanation, the inner ridge of the two ridges 44, 45 will be referred to as the "first ridge 44," and the outer ridge will be referred to as the "second ridge 45." The first ridge 44 is provided on the edge of the opening on the back side of the insertion hole 22. The second ridge 45 is provided outside the first ridge 44. These two ridges 44, 45 are arranged concentrically when viewed from the back surface side of the top cover 24. These two ridges 44, 45 may be formed integrally with the top cover 24, or may be formed separately.

[0025] Here, the insertion amount T3 of the rotary atomizing head 6 into the insertion hole 22 is not particularly limited and can be set arbitrarily. For example, it is set to about 5 mm to 20 mm from the back side of the upper cover 24, and in this embodiment, it is set to 10 mm. The protrusion amount T1 of the first protrusion 44 is set based on this insertion amount T3, and specifically, it is set to a value equal to or smaller than the insertion amount T3. Therefore, in this embodiment, the insertion amount T3 is set to about 5 mm to 10 mm. When the diameter of the rotary atomizing head 6 is large (e.g., 70 mm or more), that is, when the gap between the insertion hole 22 and the rotary atomizing head 6 is relatively small, it is preferable to set the protrusion amount T1 to 5 mm. When the diameter of the rotary atomizing head 6 is small (e.g., less than 70 mm), that is, when the gap between the insertion hole 22 and the rotary atomizing head 6 is relatively large, it is preferable to set the protrusion amount T1 to 10 mm.

[0026] The protrusion amount T1 of the first ridges 44 located on the inside is set to be equal to or smaller than the protrusion amount T2 of the second ridges 45 located on the outside. In this embodiment, the protrusion amount T1 of the first ridges 44 and the protrusion amount T2 of the second ridges 45 are set to be the same length. That is, when the protrusion amount T1 is 5 mm, the protrusion amount T2 is set to 5 mm, and when the protrusion amount T1 is 10 mm, the protrusion amount T2 is set to 10 mm.

[0027] The distance L1 between the second ridges 45 and the first ridges 44 is set to be smaller than the distance L2 between the second ridges 45 and the inner peripheral surface of the hopper body 23. In other words, the second ridges 45 are formed closer to the first ridges 44 rather than closer to the hopper body 23. The distance L1 between the second ridges 45 and the first ridges 44 is preferably about 1 / 2 to 1 / 4 of the distance L2 from the inner peripheral surface of the hopper body 23. In this embodiment, the distance L2 is set to about 30 mm, and the distance L1 is set to about 10 mm.

[0028] Next, the cleaning operation of the sprayer cleaning hopper 21 of this embodiment will be described.

[0029] First, when the sprayer 4 has finished painting an object and a color change is required to paint the next object, the controller 9 drives the arm 2 to move the sprayer 4 horizontally along the movement path. Then, when the sprayer 4 reaches a position above the insertion hole 22, the controller 9 drives the arm 2 to lower the sprayer 4. This action inserts the rotary atomizing head 6 into the sprayer cleaning hopper 21 via the insertion hole 22. The controller 9 then drives the sprayer 4 to spray paint, thereby blowing excess paint from the sprayer 4 into the sprayer cleaning hopper 21 as waste paint. At this time, shaping air may be sprayed from the rotary atomizing head 6.

[0030] Next, the controller 9 drives the atomizing head rotation motor to rotate the rotary atomizing head 6 at, for example, 25,000 rpm to 45,000 rpm. In this state, the controller 9 drives the pump 15, regulator 17a, and valve 17b to supply cleaning liquid to the in-cup cleaning nozzle and spray the cleaning liquid from inside the rotary atomizing head 6. As a result, paint adhering to the inner surface of the rotary atomizing head 6 and the internal passages of the sprayer 4 is removed by the cleaning liquid. Similarly, the controller 9 drives the pump 15, regulator 19a, and valve 19b to supply cleaning liquid to the back-cup cleaning nozzle 11 and spray the cleaning liquid from each cleaning liquid spray pipe 16 toward the rear surface of the rotary atomizing head 6. As a result, paint adhering to the rear surface of the rotary atomizing head 6 is removed by the cleaning liquid. For example, the spraying of the cleaning liquid is continued for a predetermined time (2 seconds to 10 seconds in this embodiment).

[0031] After spraying of the cleaning liquid has finished, the controller 9 stops driving the motor that rotates the atomizing head, but the rotary atomizing head 6 continues to rotate for a certain period of time due to inertial force. As a result, the cleaning liquid and waste paint adhering to the rotary atomizing head 6 are scattered to the outer periphery by centrifugal force, and the rotary atomizing head 6 dries. Therefore, when coating the next object, it is possible to prevent the cleaning liquid and waste paint from falling from the rotary atomizing head 6 onto the object, which would otherwise degrade the coating quality of the object.

[0032] After the cleaning operation is completed, the paint container inside the sprayer body 5 is filled with the next color paint to perform a color change. The controller 9 then drives the arm 2 to raise the sprayer 4, thereby moving the rotary atomizing head 6 out of the sprayer cleaning hopper 21. The controller 9 then drives the arm 2 to move the sprayer 4 to the coating start position. The controller 9 then drives the sprayer 4 to start coating the next object.

[0033] FIG. 3(a) is a schematic diagram illustrating the flow of waste paint and other materials during cup cleaning in a conventional sprayer cleaning hopper 50 without ribs 44 and 45. Meanwhile, FIG. 3(b) is a schematic diagram illustrating the flow of waste paint and other materials during cup cleaning in a sprayer cleaning hopper 21 of this embodiment with two ribs 44 and 45. In these figures, solid arrows B4 and B5 indicate the flow of liquid in the waste paint. Dashed arrows C2 and C3 indicate the flow of paint particles in the mist-like waste paint. When the conventional sprayer cleaning hopper 50 begins cup cleaning, the liquid in the waste paint discharged from the rotary atomizing head 6 flows radially toward the outer periphery of the hopper body 23 along with the cleaning liquid due to centrifugal force acting on the rotary atomizing head 6 (see B4 in FIG. 3(a)). At this time, a portion of the waste paint becomes mist and flows toward the outer periphery, then changes direction and flows diagonally upward toward the center (see C2 in FIG. 3(a)). After impacting the inner circumferential surface of the hopper body 23, the waste paint (i.e., the liquid portion) containing the cleaning liquid creeps up along the inner circumferential surface and then flows toward the center along the back side of the top cover 24 (see B5 in Figure 3(a)). Some of the waste paint that reaches this position turns into a mist and reaches the rotary atomizing head 6. As a result, paint particles in the waste paint bounce off and adhere to the periphery of the rotary atomizing head 6, making the tip of the sprayer 4 prone to becoming dirty.

[0034] In contrast, when the inside-cup cleaning operation is initiated in the sprayer cleaning hopper 21 of this embodiment, the liquid in the waste paint discharged from the rotary atomizing head 6 flows radially toward the outer periphery of the hopper body 23 together with the cleaning liquid due to centrifugal force acting on the rotary atomizing head 6 (see B4 in FIG. 3(b)). At this time, part of the waste paint becomes mist-like and flows toward the outer periphery, then changes direction and flows diagonally upward toward the center (see C2 in FIG. 3(b)). After colliding with the inner periphery of the hopper body 23, the waste paint (i.e., the liquid) containing the cleaning liquid creeps up along the inner periphery and then attempts to flow toward the center along the back side of the top cover 24 (see B5 in FIG. 3(b)). However, the second ridges 45 are present in the path of the liquid. Therefore, the second ridges 45 block the liquid in the waste paint. Therefore, the liquid content of the waste paint is less likely to adhere to the periphery of the rotary atomizing head 6, and the tip of the coater 4 is less likely to become dirty. In addition, the flow of paint particles from the inner circumferential surface of the hopper body 23 toward the center is also blocked by the second ridges 45 (see C3 in Figure 3(b)).

[0035] FIG. 4(a) is a schematic diagram illustrating the flow of waste paint and the like during cup back-side cleaning operation in a conventional sprayer cleaning hopper 50 that does not have ribs 44, 45. Meanwhile, FIG. 4(b) is a schematic diagram illustrating the flow of waste paint and the like during cup back-side cleaning operation in a sprayer cleaning hopper 21 of this embodiment that has two ribs 44, 45. In these figures, solid arrows B1 indicate the flow of cleaning liquid sprayed from the cup back-side cleaning nozzle 11. Solid arrows B2 indicate the flow of liquid in the waste paint. Dashed arrows C1 indicate the flow of paint particles in the mist-like waste paint.

[0036] When the cup back cleaning operation begins in a conventional sprayer cleaning hopper 50, the liquid in the waste paint discharged from the rotary atomizing head 6 flows downward along with the cleaning liquid (see B2 in Figure 4(a)). At this time, some of the waste paint turns into a mist and flows toward the outer periphery, then changes direction and flows diagonally upward toward the center (see C1 in Figure 4(a)). As a result, paint particles in the mist-like waste paint bounce off and adhere to the periphery of the rotary atomizing head 6, making the tip of the sprayer 4 prone to getting dirty.

[0037] In contrast, when the cup bottom cleaning operation is started in the sprayer cleaning hopper 21 of this embodiment, the liquid in the waste paint discharged from the rotary atomizing head 6 flows downward along with the cleaning liquid (see B2 in FIG. 4(b)). Meanwhile, the paint particles in the mist-like waste paint flow toward the outer periphery, then change direction and attempt to flow diagonally upward toward the center. However, the first protrusions 44 are present in their path. Therefore, the first protrusions 44 block the paint particles in the mist-like waste paint (see C1 in FIG. 4(b)). This makes it difficult for the paint particles to adhere to the periphery of the rotary atomizing head 6, and the tip of the sprayer 4 is less likely to become dirty.

[0038] Therefore, according to this embodiment, the following effects can be obtained.

[0039] (1) In the sprayer cleaning hopper 21 of this embodiment, the opening diameter D1 of the insertion hole 22 is larger than the radius D2 of the hopper body 23, allowing for a smaller hopper than conventional hopper designs. Furthermore, the two protrusions 44, 45 protruding from the backside of the top cover 24 prevent the waste paint discharged from the rotary atomizing head 6 from rebounding. The two protrusions, each with a different inner diameter and surrounding the insertion hole 22, are arranged such that the inner protrusion (first protrusion 44) primarily blocks paint particles in the mist-like waste paint. The outer protrusion (second protrusion 45) primarily blocks the liquid portion of the waste paint that creeps up along the inner circumferential surface of the hopper body 23. This allows for the sprayer cleaning hopper 21 to prevent the discharged waste paint from rebounding toward the rotary atomizing head 6.

[0040] (2) If the distance L1 between the second ridges 45 and the first ridges 44 were relatively large, the second ridges 45 would be too close to the inner peripheral surface of the hopper body 23. This could cause components other than air in the waste paint that creep up along the inner peripheral surface of the hopper body 23 to more easily reach the inner peripheral surface of the second ridges 45 rather than the outer peripheral surface. In this regard, in the paint sprayer cleaning hopper 21, the distance L1 between the second ridges 45 and the first ridges 44 is relatively small, ensuring an appropriate and sufficient distance L2 between the second ridges 45 and the inner peripheral surface of the hopper body 23. As a result, components other than air in the waste paint that creep up along the inner peripheral surface of the hopper body 23 do not reach the inner peripheral surface of the second ridges 45, but are reliably blocked by contacting the outer peripheral surface.

[0041] (3) In the sprayer cleaning hopper 21 of this embodiment, the protrusion amount T1 of the first ridges 44 is set to be equal to or smaller than the insertion amount T3 of the rotary atomizing head 6. This prevents the waste paint discharged from the rotary atomizing head 6 from directly hitting the first ridges 44, and ensures that paint particles in the mist of waste paint are blocked.

[0042] The embodiment of the present invention may be modified as follows.

[0043] In the above embodiment, the protrusion amount T1 of the first ridges 44 located on the inside was equal to the protrusion amount T2 of the second ridges 45 located on the outside. However, this is not limiting. For example, as in another embodiment of a sprayer cleaning hopper 21A shown in FIG. 5, the protrusion amount T1 of the first ridges 44 may be smaller than the protrusion amount T2 of the second ridges 45. For example, if the protrusion amount T1 of the first ridges 44 is 10 mm, the protrusion amount T2 of the second ridges 45 is set to approximately 11 mm to 15 mm. If the protrusion amount T2 of the second ridges 45 is relatively small, the waste paint ejected from the rotary atomizing head 6 may directly and forcefully hit the first ridges 44 located close to the rotary atomizing head 6 and bounce back, which may cause the rotary atomizing head 6 to become soiled. Alternatively, the protrusion amount T2 of the second ridges 45 may be insufficient, and the components other than air in the waste paint that creep up along the inner circumferential surface of the hopper body 23 may not be sufficiently blocked. In this regard, in the coater cleaning hopper 21A of another embodiment, the protrusion amount T1 of the first ridges 44 is relatively small, so the waste paint discharged from the rotary atomizing head 6 is less likely to directly hit the first ridges 44. In addition, the second ridges 45 can sufficiently block the components other than air in the waste paint that creep up. As a result, the waste paint is reliably prevented from bouncing back, and the tip of the coater 4 is less likely to become dirty.

[0044] In the above embodiment, the two protrusions 44, 45 having different inner diameters are provided on the back side of the upper cover of the insertion hole 22. However, this is not limitative. For example, three protrusions having different inner diameters may be provided.

[0045] In the above embodiment, the distance L1 between the second ridges 45 and the first ridges 44 is smaller than the distance L2 between the second ridges 45 and the inner circumferential surface of the hopper body 23. However, this is not limitative. For example, the distance L1 between the second ridges 45 and the first ridges 44 may be equal to or greater than the distance L2 between the second ridges 45 and the inner circumferential surface of the hopper body 23.

[0046] In the above embodiment, the first ridges 44 and the second ridges 45 are both provided to protrude so as to extend straight in the vertical direction, but this is not limiting. That is, the first ridges 44 and the second ridges 45 may be provided to protrude at a slight incline with respect to the vertical direction.

[0047] In the above embodiment, the first ridges 44 and the second ridges 45 are formed by providing thin plate-like structures on the back surface of the top cover 24, but this is not limiting. For example, a configuration like that of another embodiment of a sprayer cleaning hopper 21B shown in FIG. 6 may be employed. In this embodiment, a top cover 24 with a certain thickness is used, and concentric grooves, for example, several millimeters deep, are formed on the back surface of the top cover 24. Portions remain around the formed multiple annular grooves M1, and these may be used as the ridges 44, 45, respectively.

[0048] For example, if the rotary atomizing head 6 has an even smaller diameter (e.g., 30 mm to 40 mm) than that of the above embodiment, the opening diameter D1 of the insertion hole 22 may be set to, for example, about 80 mm, and only one protrusion may be provided. With this configuration, the insertion hole 22 is narrowed, which is expected to improve the effect of preventing the waste paint from being blown up or splashed back. [Explanation of symbols]

[0049] 4: Paint sprayer 6: Rotating atomization head 21, 21A, 21B: Hopper for cleaning the coating machine 22: Insertion hole 23: Hopper body 23a: Upper opening 23b: Lower opening 24:Top lid 42: Bottom D1: Opening diameter of insertion hole D2: Radius of the hopper body 44: First protrusion 45: Second ridge L1: Distance between the second ridge and the first ridge L2: Distance between the second ridge and the inner surface of the hopper body T1: Protrusion amount of the first protrusion T2: Protrusion amount of the second ridge T3: Insertion amount of the rotary atomizing head

Claims

1. A hopper for cleaning a sprayer, comprising: a hopper body having an upper opening at an upper end and a lower opening at a bottom; and an upper lid covering said upper opening, said upper lid having an insertion hole through which a rotary atomizing head rotatably provided on a sprayer can be inserted into said hopper body, The opening diameter of the insertion hole is larger than the radius of the hopper body, A plurality of protrusions are provided on the back side of the upper cover to prevent the waste paint discharged from the rotary atomizing head from bouncing back, and the plurality of protrusions have different inner diameters and surround the insertion hole. A hopper for cleaning a coating machine.

2. 2. The hopper for cleaning a sprayer according to claim 1, wherein the amount of protrusion of the inner ridge is equal to or smaller than the amount of protrusion of the outer ridge.

3. the plurality of ridges include first ridges provided on an opening edge on a rear surface side of the insertion hole and second ridges provided outside the first ridges, the first protrusions mainly block paint particles in the waste paint in mist form, The second protrusion mainly blocks components other than air in the waste paint that creep up along the inner circumferential surface of the hopper body.

3. The hopper for cleaning a coating machine according to claim 2.

4. 4. The hopper for cleaning a sprayer according to claim 3, wherein the distance between the second ridge and the first ridge is smaller than the distance between the second ridge and the inner peripheral surface of the hopper body.

5. 5. The hopper for cleaning a sprayer according to claim 3, wherein the protruding amount of said first ridge is equal to or smaller than the insertion amount of said rotary atomizing head.

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