JP6996949B2 - Powder coating equipment - Google Patents

Description

The present invention relates to a powder coating apparatus of a flow dipping method.

A flow dipping method in which a preheated work is dipped in a flow container in which a powder coating is flowed to paint is used, for example, for painting a rotor or a stator of an automobile motor.
The powder coating apparatus used in the flow immersion method generally includes a flow container capable of accommodating the powder coating material and a flow generation means provided at the lower part of the flow container. The flow generating means is, for example, a porous plate and a gas chamber of a compressed gas formed by partitioning the porous plate. Gas is sent from the porous plate of the flow generating means to the flow container, and the powder paint contained in the flow container is made to flow to form a fluidized layer of the powder paint. The preheated work is immersed in the fluidized layer of the powder paint formed in the flow container, and the powder paint is fused to the surface of the work for coating.

When it is desired to paint only a part of the work, conventionally, the unpainted part of the work is masked in advance and then immersed in the fluid container, or only a part of the work is immersed in the fluid container. However, the painting method in which each work is masked in advance is troublesome and reduces the painting efficiency. In addition, in the painting method in which only a part of the work is immersed in the fluidized container, the surface height of the fluidized bed fluctuates due to the flow of the powder paint, so the immersion position of the workpiece is mechanically determined by the immersion device. Even if it was decided, there was a possibility that the coating range of the work would vary.

Regarding the powder coating device capable of improving the dimensional accuracy of the coated area of the object to be coated, a horizontal vibration means for vibrating the powder flow container in the horizontal direction is provided, and the powder flow container is provided by this horizontal vibration means. It is said that by vibrating in the horizontal direction, the bubbles due to the air ejected into the powder flow container through the perforated plate are reduced, the size of the bubbles is reduced, and the unevenness of the flow surface is reduced (Patent Document 1).
Further, by immersing a cylinder having an inner diameter larger than that of the work in the vicinity of the bath surface of the powder bath of the powder paint housed in the paint tank, the flow of the powder paint at least in the vicinity of the bath surface is made to flow. It is said that it can be suppressed by a wall surface (Patent Document 2).

JP 2011-235240, claim 1 JP 2013-48997, claim 1

The powder coating apparatus described in Patent Document 1 can suppress fluctuations in the surface height of the fluidized bed due to air bubbles, but does not suppress fluctuations in the surface height of the fluidized bed itself. Further, in the powder coating apparatus described in Patent Document 2, the wall surface of the inner cylinder can suppress the flow in the direction along the bath surface of the powder bath, but the fluctuation of the surface height of the fluidized bed can be sufficiently suppressed. It did not suppress it.

The present invention has an advantage in solving the above problems, and an object of the present invention is to provide a powder coating apparatus capable of suppressing fluctuations in the surface height of a fluidized bed.

As a result of diligent studies to solve the above problems, the present inventors have provided an inner cylinder in the flow container of the powder coating apparatus, and by causing the powder paint to overflow from the inner cylinder, the surface height of the fluidized layer is increased. It was found that the fluctuation of the above can be suppressed, and the powder coating apparatus of the present invention was obtained from it.

The powder coating apparatus of the present invention is a fluid dipping method powder coating apparatus in which a work is dipped in a fluidized layer in which a powder coating material is flowed to coat the work, and is a fluidized container capable of accommodating the powder coating material and an upper end. An inner cylinder consisting of a hollow cylinder having an opening at the lower end and an opening at the upper end into which a portion to be painted of the work can be inserted, and an air flow from the lower part to the upper part of the inner cylinder. The inner cylinder is provided with a flow generating means for forming a flow layer of the powder coating material inside the inner cylinder, and the inner cylinder is provided with a gap from the flow container, and the inner cylinder is provided from the upper end of the inner cylinder. It is characterized by overflowing powder paint.

In the powder coating apparatus of the present invention, it is preferable that the powder coating material overflowing from the upper end of the inner cylinder is collected in the flow container, and the opening at the upper end of the inner cylinder is smaller than the opening at the lower end. Is preferable.

Further, the powder coating apparatus of the present invention is a fluid coating apparatus of a flow dipping method in which a work is immersed in a fluidized layer in which a powder coating material is flowed to coat the work, and is a fluid container capable of accommodating the powder coating material. An inner cylinder having an opening in the upper part into which a portion to be painted of the work can be inserted, which also serves as the fluid container, and an air flow from the lower part to the upper part of the inner cylinder are generated inside the inner cylinder to form the powder paint. It is provided with a flow generating means for forming a flow layer, and is characterized in that the powder coating material overflows from the upper end of the inner cylinder.

In the powder coating apparatus of the present invention, the flow generating means may include a porous plate provided on the lower side in the flow container and a gas chamber of compressed gas that sends gas through the porous plate. preferable.
Further, it is preferable that the flow generator includes a porous plate provided on the lower side in the flow container and a gas chamber of compressed gas that sends gas through the porous plate.

According to the powder coating apparatus of the present invention, fluctuations in the surface height of the fluidized bed can be suppressed and stable coating can be performed.

It is a schematic diagram of Embodiment 1 of the powder coating apparatus of this invention. It is a schematic diagram of Embodiment 2 of the powder coating apparatus of this invention. It is a schematic diagram of Embodiment 3 of the powder coating apparatus of this invention. It is a schematic diagram of Embodiment 4 of the powder coating apparatus of this invention.

Hereinafter, embodiments of the powder coating apparatus of the present invention will be described more specifically with reference to the drawings.
(Embodiment 1)
The powder coating apparatus 1 of the first embodiment of the present invention shown in FIG. 1 is a coating apparatus by a flow dipping method, and includes a fluidized container 2 capable of accommodating powder paint. At the bottom of the flow container 2, a porous plate 3 for partitioning the flow container 2 is provided. A space gas chamber 4 is formed below the flow container 2 partitioned by the porous plate 3. The porous plate 2 and the gas chamber 4 are components of the flow generating means 5.

The gas chamber 4 is connected to the gas supply device 7. A gas, for example, air or an inert gas, is supplied from the gas supply device 7 to the gas chamber 4, and the gas in the gas chamber 4 whose pressure has been increased is sent above the flow vessel 2 through the porous plate 3. The powder coating material contained above the porous plate 3 in the fluidized container 2 is levitated by the pumped gas to form a fluidized bed.

The powder coating apparatus 1 of the present embodiment includes an inner cylinder 6 in the fluidized container 2. The inner cylinder 6 is a hollow cylinder having openings at the upper end 6a and the lower end 6b. The opening of the upper end 6a has a size into which a portion to be painted of the work W can be inserted. The inner cylinder 6 has a cylindrical shape in one example, but is not limited to the cylindrical shape and may have a square cylinder shape or the like. The length from the upper end 6a to the lower end 6b of the inner cylinder 6, that is, the length of the inner cylinder 6 is shorter than the length from the upper end of the fluidized vessel 2 to the porous plate 3. When the inner cylinder 6 is mounted in the fluidized container 2, an appropriate distance is provided between the lower end 6b of the inner cylinder 6 and the porous plate 3. The attachment of the inner cylinder 6 is not particularly limited, and may be, for example, any structure capable of fixing at least one of the lower end portion, the body portion and the upper end portion of the inner cylinder 6 in the flow container 2.

The gas sent from the porous plate 3 located below the inner cylinder 6 creates an air flow from the lower part to the upper part inside the inner cylinder 6, thereby causing the powder coating material to flow in the same direction as the air flow. It produces such a fluidized bed. By adjusting the height of the upper end of the inner cylinder 6 and making the height of the fluidized bed inside the inner cylinder 6 higher than the height of the fluidized bed outside the inner cylinder 6, the powder inside the inner cylinder 6 is formed. The body paint is made to overflow outward at the upper end.

The powder coating material that overflows from the upper end of the inner cylinder 6 to the outside is returned to the powder coating material in the fluidizing container 2. In this way, in the fluidized container 2, the powder paint below the inner cylinder 6 forms a fluidized bed that flows from the lower part to the upper part inside the inner cylinder 6, overflows from the upper end, and is inside the fluidized container 2. Form a circulation path back into the powder coating. As a means for replenishing the powder coating material, for example, a new powder coating material can be replenished by a conventionally known method, such as supplying a new powder coating material into the fluidized container 2 by a powder pump (not shown).

The powder coating by the powder coating apparatus 1 of the present embodiment is performed by lowering the work W from above the inner cylinder 6 and immersing the portion to be coated in the fluidized bed inside the inner cylinder 6. The powder coating apparatus 1 of the present embodiment includes an inner cylinder 6, and forms a fluidized layer of powder coating material from the lower part to the upper part inside the inner cylinder 6, and the powder coating material is formed from the upper end 6a of the inner cylinder 6. The height of the fluidized bed of the powder coating material inside the inner cylinder 6 is kept constant at the height at which the fluidized bed overflows. Therefore, since fluctuations in the surface height of the fluidized bed are suppressed, it is possible to improve the dimensional accuracy of the coated region when the work W is partially immersed in the fluidized bed inside the inner cylinder 6 for coating.

In order to make the fluidized bed of the powder paint inside the inner cylinder 6 overflow from the upper end 6a to the outside, the height of the fluidized bed inside the inner cylinder 6 is increased to the height of the fluidized bed outside the inner cylinder 6. I am doing it. A more suitable powder coating apparatus for that purpose will be described below.

(Embodiment 2)
A schematic diagram of the powder coating apparatus of the second embodiment is shown in FIG. The powder coating device 11 shown in FIG. 2 includes a flow container 2, a porous plate 3, a gas chamber 4, a flow generation means 5, an inner cylinder 16, and a gas supply device 7. Among these members, the flow container 2, the porous plate 3, the gas chamber 4, the flow generating means 5, and the gas supply device 7 are the flow container 2, the porous plate 3, and the gas chamber of the powder coating device 1 of FIG. 4. It has the same structure as the flow generating means 5 and the gas supply device 7, and in FIG. 2, these members are designated by the same reference numerals as those in FIG. Therefore, in the description of the powder coating apparatus 11 described below, the duplicate description of the same member as in FIG. 1 will be omitted.

The inner cylinder 16 of the powder coating apparatus 11 is a hollow cylinder having openings at the upper end 16a and the lower end 16b. The opening of the upper end 16a has a size into which a portion to be painted of the work can be inserted. The length from the upper end 16a to the lower end 16b, that is, the length of the inner cylinder 16, is shorter than the length from the upper end of the fluidized vessel 2 to the porous plate 3. When the inner cylinder 16 is mounted in the fluidized container 2, an appropriate distance is provided between the lower end 16b of the inner cylinder 16 and the porous plate 3. The attachment of the inner cylinder 16 is not particularly limited, and may be, for example, any structure capable of fixing at least one of the lower end portion, the body portion and the upper end portion of the inner cylinder 16 in the flow container 2.

The gas sent from the porous plate 3 located below the inner cylinder 16 creates an air flow from the lower part to the upper part inside the inner cylinder 16, thereby causing the powder coating material to flow in the same direction as the air flow. It produces such a fluidized bed. By adjusting the height of the upper end of the inner cylinder 6 and making the height of the fluidized bed inside the inner cylinder 16 higher than the height of the fluidized bed outside the inner cylinder 6, the powder inside the inner cylinder 6 is formed. The body paint is made to overflow outward at the upper end.

The powder coating material that overflows from the upper end of the inner cylinder 16 to the outside is returned to the powder coating material in the fluidizing container 2. In this way, in the fluidized container 2, the powder coating material below the inner cylinder 16 forms a fluidized bed that flows from the lower part to the upper part inside the inner cylinder 16 and overflows from the upper end in the fluidized container 2. Form a circulation path back into the powder coating.

The powder coating by the powder coating apparatus 11 of the present embodiment is performed by lowering the work from above the inner cylinder 16 and immersing the portion to be coated in the fluidized bed inside the inner cylinder 16. The powder coating apparatus 11 of the present embodiment includes an inner cylinder 16, and forms a fluidized layer of powder coating material from the lower part to the upper part inside the inner cylinder 16, and the powder coating material is formed from the upper end 16a of the inner cylinder 16. The height of the fluidized bed of the powder coating material inside the inner cylinder 16 is kept constant at the height at which the fluidized bed overflows. Therefore, since fluctuations in the surface height of the fluidized bed are suppressed, it is possible to improve the dimensional accuracy of the coated region when the work is partially immersed in the fluidized bed inside the inner cylinder 16 for coating.

In the powder coating apparatus 11 of the present embodiment, the inner cylinder 16 has an opening at the upper end 16a smaller than the opening at the lower end 16b. Specifically, the inner cylinder 16 can have a hollow truncated cone shape or a hollow truncated cone shape. Since the inner cylinder 16 has a shape in which the opening of the upper end 16a is smaller than the opening of the lower end 16b, the speed head of the fluidized bed of the powder coating from the lower part to the upper part inside the inner cylinder 16 is an inner cylinder. Higher than the velocity head of the outer fluidized bed of 16. Therefore, the height of the fluidized bed inside the inner cylinder 16 can be made higher than that of the fluidized bed outside the inner cylinder 16, so that the fluidized bed of the powder paint inside the inner cylinder 16 is placed from the upper end to the outside. In addition, it can be easily overflowed.

The powder coating apparatus 11 of the present embodiment has the same height as the powder coating apparatus 1 shown in FIG. 1 in order to make the height of the fluidized bed inside the inner cylinder 16 higher than that of the fluidized bed outside the inner cylinder 16. In comparison with, the shape of the inner cylinder 16 is devised. Next, a powder coating apparatus according to another embodiment of the present invention, in which a porous plate is devised instead of the shape of the inner cylinder 16, will be described.

(Embodiment 3)
FIG. 3 shows a schematic view of the powder coating apparatus 21 according to the third embodiment of the present invention. The powder coating device 21 shown in FIG. 3 includes a flow container 2, a porous plate 23, a gas chamber 4, a flow generation means 25, an inner cylinder 6, and a gas supply device 7. Among these members, the flow container 2, the gas chamber 4, the inner cylinder 6, and the gas supply device 7 include the flow container 2, the gas chamber 4, the inner cylinder 6, and the gas supply device 7 of the powder coating device 1 of FIG. It has a similar structure, and in FIG. 3, these members are designated by the same reference numerals as those in FIG. Therefore, in the description of the powder coating apparatus 21 described below, the duplicate description of the same member as in FIG. 1 will be omitted.

The powder coating apparatus 21 is provided with a porous plate 23 for partitioning the fluidized container 2, and a gas chamber 4 in a space is formed below the fluidized container 2 partitioned from the porous plate 23. The porous plate 23 and the gas chamber 4 are components of the flow generating means 25. The gas chamber 4 is connected to the gas supply device 7. A gas, for example, air or an inert gas, is supplied from the gas supply device to the gas chamber 4, and the gas in the gas chamber 4 whose pressure has been increased is sent above the flow vessel 2 through the porous plate 23. The powder coating material contained above the porous plate 23 in the fluidized container 2 is levitated by the pumped gas to form a fluidized bed.

The difference between the porous plate 23 shown in FIG. 3 and the porous plate 3 shown in FIGS. 1 and 2 is that the opening ratio of the holes in the porous plate 23 in FIG. 3 is inside the inner cylinder 6. The opening ratio of the facing region is larger than the opening ratio of the region facing the outside of the inner cylinder 6. For the porous plate 23, the opening ratio of the holes is made different in the plane, and the region facing the inside of the inner cylinder 6, for example, the opening ratio of the central region 23a of the porous plate 23 is the region facing the outside of the inner cylinder 6. For example, by making it larger than the opening ratio of the peripheral region 23b of the porous plate 23, the speed head of the fluidized bed of the powder coating from the lower part to the upper part inside the inner cylinder 6 is the fluidized bed on the outer side of the inner cylinder 6. Higher than the speed head of. Therefore, the height of the fluidized bed inside the inner cylinder 6 can be made higher than the fluidized bed outside the inner cylinder 6, so that the fluidized bed of the powder paint inside the inner cylinder 6 is placed from the upper end to the outside. In addition, it can be easily overflowed.

In the powder coating apparatus 21 shown in FIG. 3, the opening ratio of the holes of the porous plate 23 is made different in the plane, and the height of the fluidized bed inside the inner cylinder 6 is set higher than that of the fluidized bed outside the inner cylinder 6. However, the structure in which the speed head of the gas sent to the fluidized bed 2 through the porous plate 23 is different between the inside and the outside of the inner cylinder 6 is not limited to the device shown in FIG. For example, when the inner cylinder 6 is located at the center of the fluidized vessel 2 in the horizontal cross section of the fluidized vessel 2, it faces at least one surface of the main surface of the porous plate 3, for example, a gas chamber. A gas velocity head that passes through the central region of the porous plate 3 by providing a shielding plate or a plate with low gas permeability in a region other than the central region on the surface of the surface, that is, a peripheral region. Can be configured to be higher than the velocity head of the gas passing through the peripheral region. Further, the gas chamber 4 is divided into a peripheral region and a central region of the porous plate 3, and the amount of gas blown toward the central region is made larger than the amount of air blown toward the peripheral region, whereby the periphery of the porous plate 3 is formed. The gas velocity head passing through the central region, which is a region other than the region, may be made higher than the gas velocity head passing through the peripheral region.

(Embodiment 4)
FIG. 4 shows a schematic view of the powder coating apparatus 31 according to the fourth embodiment of the present invention. The powder coating apparatus 31 shown in FIG. 4 includes an outer tank 321 capable of accommodating powder paint, an inner tank 322 (fluid container) housed in the outer tank 321 and a porous plate 33 provided in the inner tank 322. It is provided with a gas chamber 34 and a flow generating means 35.
In the powder coating apparatus 31 of the present embodiment shown in FIG. 4, the powder coating material is housed in the outer tank 321 and the inner tank 322. A porous plate 33 for partitioning the inner tank 322 is provided at the bottom of the inner tank 322. A gas chamber 34, which is a space, is formed below the inner tank 322 partitioned by the porous plate 33. The porous plate 33 and the gas chamber 34 are components of the flow generating means 35.

In the gas chamber 34, a gas such as air or an inert gas is supplied from the gas supply device 7 to the gas chamber 34, and the gas in the gas chamber 34 whose pressure is increased is passed above the inner tank 322 through the porous plate 33. send. The powder coating material contained above the porous plate 33 in the inner tank 322 is floated by the pumped gas to form a fluidized bed. The work is dipped in this fluidized bed and painted.

The upper end of the inner tank 322 is open. The inner tank 322 can be said to be a bottomed inner cylinder. The opening at the upper end has a size that allows the painted portion of the work to be inserted. The inner tank 322 has a cylindrical shape in one example, but is not limited to the cylindrical shape and may have a square tubular shape or the like. The attachment of the inner tank 322 is not particularly limited, and for example, at least one of the lower end portion, the body portion, and the upper end portion of the inner tank 322 can be any structure that can be fixed in the outer tank 321.

In the inner tank 322, the gas sent from the porous plate 33 located below the inner tank 322 creates an air flow from the lower part to the upper part inside the inner tank 322, thereby powder in the same direction as the air flow. A fluidized bed is formed so that the body paint can flow, and the powder paint inside the inner tank 322 overflows to the outside at the upper end for at least the time when the work is immersed in the fluidized bed.

The powder coating material that overflows from the upper end of the inner tank 322 to the outside is returned to the powder coating material in the outer tank 321. The powder coating material is supplied from the outer tank 321 to the inner tank 322 by a powder supply means 36, for example, a powder pump. The powder may be supplied to the inner tank 322 at a time when the powder coating is suspended, not at the time of the powder coating in which the fluidized bed is formed in the inner tank 322. In this way, in the outer tank 321, the powder coating material contained above the porous plate 33 in the inner tank 322 forms a fluidized bed that flows from the lower part to the upper part inside the inner tank 322. It forms a circulation path that overflows from the upper end and returns to the powder coating material in the outer tank 321. As a means for replenishing the powder coating material, for example, a new powder coating material can be replenished by a conventionally known method, such as supplying a new powder coating material into the outer tank 321 by a powder pump (not shown).

The powder coating apparatus 31 of the present embodiment accommodates the inner cylinders 6 and 16 of the powder coating apparatus 1, 11 and 21 of the above-described embodiments 1 to 3 and the powder coating material to form a fluidized layer. The same one inner tank 322 also serves as the fluid container 2 as a container.

The powder coating by the powder coating apparatus 31 of the present embodiment is performed by lowering the work from above the inner tank 322 and immersing the portion to be coated in the fluidized bed inside the inner tank 322. The powder coating apparatus 31 of the present embodiment including the inner tank 322 forms a fluidized layer of powder paint from the lower part to the upper part inside the inner tank 322, and overflows the powder paint from the upper end of the inner tank 322. Therefore, the height of the fluidized bed of the powder coating material inside the inner tank 322 is kept constant at the height when the fluidized bed overflows. Therefore, since fluctuations in the surface height of the fluidized bed are suppressed, it is possible to improve the dimensional accuracy of the coated region when the work is partially immersed in the fluidized bed inside the inner tank 322 for coating.

Although each embodiment of the powder coating apparatus of the present invention has been described above, the powder coating apparatus of the present invention is not limited to these embodiments. The powder coating apparatus of the present invention can be modified in many ways without departing from the spirit of the present invention.

1, 11, 21, 31 Powder coating device 2 Flow container 3, 23, 33 Porous plate 4, 34 Gas chamber 5, 25, 35 Flow generating means 6, 16 Inner cylinder 7 Gas supply device 321 Outer tank 322 Inner tank (Fluid container)

Claims (4)

It is a powder coating device of the fluidized immersion method that coats by immersing the work in the fluidized bed in which the powder coating is flowed.
A fluid container that can store powder paint and
An inner cylinder composed of a hollow cylinder having openings at the upper end and the lower end, which is provided in the flow container and in which the opening at the upper end can insert a portion to be painted on the work.
A flow generating means for generating an air flow from the lower part to the upper part of the inner cylinder to form a fluidized layer of the powder coating material inside the inner cylinder.
Equipped with
The inner cylinder is provided at a distance from the fluidized container.
A powder coating apparatus characterized in that the powder coating material overflows from the upper end of the inner cylinder. The powder coating apparatus according to claim 1, wherein the powder coating material overflowing from the upper end of the inner cylinder is collected in the fluidizing container. The powder coating apparatus according to claim 1 or 2, wherein the opening at the upper end of the inner cylinder is smaller than the opening at the lower end. The item according to any one of claims 1 to 3 , wherein the flow generating means includes a porous plate provided on the lower side in the flow container and a gas chamber of a compressed gas that sends gas through the porous plate. Powder coating equipment.

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