JP5647525B2 - Electrostatic powder spreader - Google Patents

Description

  The present invention relates to an electrostatic powder spraying device that sprays powder uniformly on the surface of an object using electrostatic force.

  The general method of spraying edible powder (such as wheat flour) on a three-dimensional food such as a wharf is to carry the food into the spray chamber with a conveyor, and use a rotating brush to lift the powder into the spray chamber and then This is a method of adhering powder to the surface. However, in this method, the soared powder leaks out from between the conveyor and the wall of the spraying chamber, and contaminates the surrounding atmosphere. Since powder easily diffuses in the air and it is extremely difficult to capture the powder once diffused in the air, a powder spraying device that does not leak the powder is required.

  An electrostatic powder spraying device that uses electrostatic force to attach powder to an object provides one solution to prevent the powder from diffusing into the surrounding atmosphere. The principle of this electrostatic powder spraying device will be described with reference to FIG. As shown in FIG. 1, the electrostatic powder spraying device includes a pallet 201 on which a powder spraying target object 200 such as food is placed, a screen 202 having a mesh, and a roll brush 203 on the screen 202. .

  The screen 202 is connected to the negative electrode of the DC voltage source DC, and the pallet 201 is connected to the positive electrode of the DC voltage source DC and grounded. A high voltage is applied between the screen 202 and the pallet 201 by the direct-current voltage source DC, whereby an electrostatic field is formed between the screen 202 and the pallet 201. The powder supplied onto the screen 202 is rubbed into the mesh of the screen 202 by the rotating roll brush 203 and pushed out to the lower side of the screen 202. At this time, the powder is negatively charged by friction with the rotating roll brush 203. Therefore, the powder is attracted to the grounded object 200 and adheres to the surface of the object 200.

  Such an electrostatic powder spraying device has the advantage that the powder can be sprayed onto the object while keeping the ambient atmosphere clean, since it is not necessary to make the powder fly with a brush. Usually, foods such as buns are transported to the electrostatic powder spraying device with the powder already attached to the bottom surface. Therefore, in the electrostatic powder spraying device, the powder is applied to the entire surface excluding the bottom surface of the object. Is sprayed. However, this electrostatic powder spraying device has a problem that the powder hardly adheres to the lower part of the side surface of the object.

  FIG. 2 is a schematic diagram for explaining how powder adheres to an object. As described above, the negatively charged powder is attracted to the object 200. However, the powder traveling in the vicinity of the side surface of the target object 200 is attracted to the pallet 201 before adhering to the target object 200. This is because the resultant force of the Coulomb force acting between the powder and the pallet 201 and the gravity of the powder is superior to the Coulomb force acting between the powder and the object 200. Such a phenomenon occurs around the side surface of the object 200, and as a result, the powder cannot be attached to the entire side surface of the object 200.

JP 2002-347221 A

The present invention has been made in view of the above-described conventional problems, and provides an electrostatic powder spraying device that can spray powder uniformly over the entire object such as food using electrostatic force. This is the first purpose.
It is a second object of the present invention to provide an electrostatic powder spraying apparatus capable of attaching powder to the lower part of the side surface of an object such as food using electrostatic force.

In order to achieve the above-described object, one aspect of the present invention is an electrostatic powder spraying device for spraying powder onto an object, a screen having a mesh, and a screen for rubbing the powder onto the screen. A brush, a hopper that supplies the powder to the screen brush, a conveyor that is disposed below the screen and carries the object, and a powder that spreads the powder onto the object from under the object A spray unit, and a DC voltage source for applying a voltage between the screen and the object, and between the powder spray unit and the object , the powder spray unit It has a rotating brush that pops up.

In a preferred aspect of the present invention, the apparatus further includes a lift mechanism that lifts the object toward the screen .
In a preferred aspect of the present invention, the powder spraying unit further includes a semi-cylindrical member in which the rotating brush is accommodated, and a brush contact unit that contacts hair of the rotating brush.

In a preferred aspect of the present invention, the conveyor has a belt on which the object is placed, and the powder spreading unit has a scraper that scrapes the powder from the belt and drops it onto the rotating brush. It is characterized by that.
A preferred aspect of the present invention further includes a powder cover that receives the powder sprayed from the powder spraying portion, and the powder cover has a shape surrounding the object. .
In a preferred aspect of the present invention, the powder spraying unit is disposed below the screen.
Another aspect of the present invention is an electrostatic powder spraying device for spraying powder onto an object, the powder spraying unit spraying the powder onto the object from below the object, and the powder A DC voltage source that applies a voltage between the body spraying unit and the object is provided, and the powder spraying unit includes a rotating brush that splashes the powder.

  According to the present invention, an electrostatic field is formed between the powder spraying unit and the target object by applying a voltage between the powder spraying unit and the target object. Therefore, the powder that has jumped out of the powder spraying part travels toward the object by the action of the electrostatic field, and adheres to the surface of the object. Since the powder spraying unit sprays the powder from below the powder material, the powder adheres to the bottom surface and the lower part of the side surface of the object. On the other hand, powder is spread on the upper surface and the upper part of the side surface of the object by the screen and the screen brush. Thus, according to the present invention, the powder can be uniformly dispersed over the entire object including the top surface, the side surface, and the bottom surface.

It is a schematic diagram explaining the principle of an electrostatic powder spraying apparatus. It is a schematic diagram explaining a mode that powder adheres to foodstuffs. It is a side view which shows the electrostatic powder spraying apparatus which concerns on one Embodiment of this invention. It is the figure which looked at the electrostatic powder spraying apparatus shown in FIG. 3 from the arrow A direction. It is a BB arrow directional view of the electrostatic powder spraying apparatus shown in FIG. FIG. 6A is a cross-sectional view showing a screen brush, and FIG. 6B is a plan view showing the screen brush. Fig.7 (a) is sectional drawing which shows the modification of a screen brush, FIG.7 (b) is a top view of the screen brush shown to Fig.7 (a). It is the figure which looked at the wiper brush from the bottom. It is a top view which shows a screen. It is a front view which shows a powder dispersion | spreading part. It is sectional drawing which shows a powder dispersion | spreading part. It is a figure which shows the example of the electrostatic powder spraying apparatus provided with the powder cover. Fig.13 (a) is sectional drawing of a powder cover, FIG.13 (b) is a side view of a powder cover. It is a figure which shows the example of the electrostatic powder spraying apparatus provided with the lift mechanism. It is a figure which shows the example which combined the powder cover shown in FIG. 12, and the lift mechanism shown in FIG. It is a figure which shows the electrostatic powder spraying apparatus which concerns on other embodiment of this invention. It is a figure which shows the electrostatic powder spraying apparatus which has a some powder spraying part.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 3 is a side view showing an electrostatic powder spraying device according to an embodiment of the present invention. 4 is a view of the electrostatic powder spraying device shown in FIG. 5 is a BB line arrow view of the electrostatic powder spraying device shown in FIG. This electrostatic powder spraying device includes a screen 2 on which a fine mesh through which powder passes is formed, and a screen brush 3 in contact with the upper surface of the screen 2. The screen brush 3 is connected to a drive shaft 5 that extends substantially perpendicular to the screen 2, and this drive shaft 5 is connected to a motor M <b> 1 via a universal joint 6. Therefore, when the motor M1 is driven, the screen brush 3 rotates on the screen 2 around its central axis.

  Below the screen 2, there is provided a conveyor 10 that conveys a powder application object 1 such as food (hereinafter simply referred to as the object 1). As shown in FIGS. 4 and 5, the conveyor 10 includes a belt 11 on which the object 1 is placed, a motor M <b> 2 that drives the belt 11, and a transport plate 13 that supports the belt 11. . The belt 11 is movably supported by a plurality of guide rollers, and the belt 11 circulates by driving the motor M2.

  Below the screen 2, a transport plate 13 having a flat upper surface is disposed horizontally. This conveyance plate 13 is comprised from the metal, and is connected to DC voltage source DC. A part of the belt 11 is located on the upper surface of the transport plate 13, and the object 1 is moved in the horizontal direction by the belt 11. The transport plate 13 is fixed to a support member 32, and the support member 32 is fixed to the support frame 30 by bolts 34.

  A hopper 40 for supplying powder to the upper surface of the screen brush 3 is provided above the screen brush 3 as shown in FIG. The hopper 40 includes a hopper container 41 in which powder is accommodated, a hopper brush 42 disposed in the hopper container 41, and a motor M3 that rotates the hopper brush 42. A slit (not shown) is formed at the bottom of the hopper container 41, and the hopper brush 42 is disposed along the slit. The screen brush 3 is disposed below the slit. When the hopper brush 42 is rotated around its axis by the motor M3, the powder in the hopper container 41 is supplied to the upper surface of the screen brush 3 through the slit.

  6A is a sectional view showing the screen brush 3, and FIG. 6B is a plan view showing the screen brush 3. As shown in FIG. The screen brush 3 includes a sponge brush 50 having a substantially disk shape, and a circular brush presser 53 disposed on the upper surface of the sponge brush 50. The sponge brush 50 is made of urethane in which open cells are formed. The upper and lower surfaces of the sponge brush 50 are circular, and the lower surface of the sponge brush 50 is in contact with the upper surface of the screen 2. The diameter of the sponge brush 50 is set larger than the width of the object 1.

  The brush holder 53 has a lower surface that coincides with the upper surface of the sponge brush 50, and an annular weir 53 a is formed on the peripheral edge of the brush holder 53. The weir 53a projects upward and extends along the outer periphery of the sponge brush 50. The weir 53a has a role of preventing powder supplied to the upper surface of the screen brush 3 from jumping out of the screen brush 3 due to centrifugal force. As shown in FIGS. 6A and 6B, the sponge brush 50 and the brush presser 53 are formed with a plurality of through holes 60 penetrating in the vertical direction. These through holes 60 are arranged at equal intervals around the central axis of the screen brush 3.

  A male screw (not shown) is formed on the outer peripheral surface of the drive shaft 5, and a nut 54 is engaged with the male screw. The nut 54 presses the brush presser 53 downward via a washer 55. Therefore, by rotating the nut 54, the force with which the brush presser 53 presses the sponge brush 50 against the screen 2 can be adjusted. Further, the screen brush 3 can be detached from the drive shaft 5 by loosening the nut 54. At the center of the sponge brush 50, a core 58 having a key groove 58a extending in the vertical direction is disposed. The core 58 is fixed to the sponge brush 50. A key 59 is formed in the vicinity of the tip of the drive shaft 5, and this key 59 is inserted into the key groove 58a. Due to the engagement between the key 59 and the key groove 58a, the torque of the drive shaft 5 is transmitted to the sponge brush 50, whereby the sponge brush 50 and the brush presser 53 rotate around the drive shaft 5.

  A powder wiper 56 is disposed on the upper surface of the brush holder 53. The powder wiper 56 extends along the radial direction of the screen brush 3 and is disposed so as to cross the upper opening end of the through hole 60. The powder wiper 56 is supported by a support member (not shown), and its position is fixed. That is, the powder wiper 56 is only in contact with the upper surface of the screen brush 3 and does not rotate with the screen brush 3. The position of the powder wiper 56 is a position away from the powder supply position from the hopper 40 (see FIG. 4). Most of the powder supplied from the hopper 40 falls to the screen 2 through the through hole 60, while a part of the powder remains on the brush presser 53. When the screen brush 3 rotates, the powder on the brush holder 53 is collected by the powder wiper 56 and dropped into the through hole 60. In this way, almost all the powder supplied to the screen brush 3 is supplied onto the screen 2 through the through hole 60.

  Fig.7 (a) is sectional drawing which shows the modification of the screen brush 3, FIG.7 (b) is a top view of the screen brush 3 shown to Fig.7 (a). The screen brush 3 of this example has the same basic configuration as the screen brush 3 shown in FIGS. 6A and 6B, but the screen brush 3 of this example has a plurality of slit-shaped upper opening ends. The through-hole 60 is formed. These through holes 60 extend in the radial direction of the screen brush 3 and penetrate the screen brush 3 in the vertical direction. More specifically, the brush holder 53 is formed with a plurality of slits 53b extending in the radial direction of the screen brush 3, and the sponge brush 50 is formed with a long hole 50a communicating with the slit 53b. The long hole 50a of the sponge brush 50 is located at a position corresponding to the slit 53b of the brush holder 53, and the long hole 50a has the same horizontal sectional shape as the slit 53b or larger than the slit 53b. Each slit 60 is formed by the slit 53b and the long hole 50a.

  In this example, as the powder wiper disposed on the upper surface of the screen brush 3, a wiper brush 56 having a large number of flexible hairs 56a is used. The bristles 56 a are made of a resin such as nylon or polypropylene, and extend substantially perpendicular to the upper surface of the screen brush 3. The lower end of the bristles 56a is in contact with the upper surface of the screen brush 3 (that is, the upper surface of the brush presser 53), and the upper end is fixed to the base plate 56b.

  FIG. 8 is a view of the wiper brush 56 as viewed from below. The hair 56a of the wiper brush 56 is fixed in a circular area on the base plate 56b. The size of this circular area is slightly smaller than the upper surface of the screen brush 3. A part of the wiper brush 56 is formed with a notch 56 c that allows the powder supplied from the hopper 40 to drop onto the upper surface of the screen brush 3. The notch 56 c extends radially outward from the center of the wiper brush 56 and is positioned below the hopper brush 42. The base plate 56b is supported by a support member (not shown), and the position of the wiper brush 56 is fixed.

  The bristles 56a of the wiper brush 56 are in contact with substantially the entire upper surface of the screen brush 3 except for the portions where the notches 56c are formed. The powder that has dropped onto the upper surface of the screen brush 3 through the notch 56c is dropped into the through hole 60 by the wiper brush 56 as the screen brush 3 rotates. The bristles 56a are arranged on the base plate 56b at predetermined intervals, and the powder supplied to the upper surface of the screen brush 3 during one rotation of the screen brush 3 is passed through the bristles 56a of the wiper brush 56. It is dropped into the hole 60. That is, the slit which is the upper opening portion of the through hole 60 so that the powder supplied to the upper surface of the screen brush 3 is dropped into all the through holes 60 by a substantially equal amount during one rotation of the screen brush 3. The width of 53b and the interval between the hairs 56a are set. Therefore, the powder is rubbed uniformly into the screen 2 over the entire lower surface of the screen brush 3, and thereby the powder adheres uniformly to the object 1.

  FIG. 9 is a plan view showing the screen 2 used in the present embodiment. As shown in FIG. 9, the screen 2 has a mesh 2a through which powder passes. The size of the mesh 2a is larger than the lower surface of the screen brush 3, and the entire lower surface of the screen brush 3 is in contact with the mesh 2a as shown in FIG. The powder supplied from the hopper 40 is slid onto the mesh 2 a of the screen 2 by the screen brush 3.

  As shown in FIG. 3, the screen 2 is supported horizontally by an insulating frame 8 made of an insulating material. Each of the screen 2 and the conveyor 10 is electrically connected to a DC voltage source (DC voltage generator) DC. More specifically, the screen 2 is connected to the negative electrode of the DC voltage source DC, and the transport plate 13 of the conveyor 10 is electrically connected to the positive electrode of the DC voltage source DC. Further, the transport plate 13 is grounded. The belt 11 has a conductive wire (not shown) incorporated therein, and the belt 11 is in electrical contact with the transport plate 13 through the conductive wire. Therefore, the belt 11 is electrically connected to the positive electrode of the direct-current voltage source DC via the transport plate 13. The belt 11 may be directly connected to the positive electrode of the DC voltage source DC. A voltage (for example, a DC high voltage of 5000 V to 6000 V) is applied between the screen 2 and the transport plate 13 (and the object 1 on the belt 11) by the DC voltage source DC, whereby the screen 2 and the object 1 are applied. An electrostatic field is formed between the two.

  The electrostatic powder spraying device is usually installed adjacent to a conveyor installed in a facility such as a factory. For example, as shown in FIG. 3, the electrostatic powder spraying device is installed between the upstream conveyor 100A and the downstream conveyor 100B. The electrostatic powder spraying device receives the object 1 from the upstream conveyor 100A and sprays the powder onto the surface thereof. The object 1 on which the powder is dispersed is received by the downstream conveyor 100B.

  As shown in FIG. 3, below the downstream end of the belt 11, a powder spraying unit (auxiliary powder spraying) for spraying powder onto the target 1 from below the target 1 conveyed by the conveyor 10. Part) 20 is arranged. The powder spraying unit 20 sprays powder onto the target 1 from below the target 1 through a minute gap between the belt 11 and the downstream conveyor 100B.

  FIG. 10 is a front view showing the powder spreading unit 20. FIG. 11 is a cross-sectional view showing the powder spraying unit 20. The powder spreading unit 20 includes a rotating brush 21 that splashes powder, a motor M4 that rotates the rotating brush 21, and a semi-cylindrical member 22 in which the rotating brush 21 is accommodated. The semi-cylindrical member 22 has a shape surrounding the lower half of the rotating brush 21, and the upper half of the semi-cylindrical member 22 is cut away. The motor M4 is connected to the rotating brush 21 via a joint 29 made of an insulating material. The axial direction of the rotating brush 21 is substantially perpendicular to the traveling direction of the object 1 conveyed by the belt 11 (see FIG. 5). A minute gap is formed between the rotating brush 21 and the inner peripheral surface of the semi-cylindrical member 22. The rotating brush 21 and the inner peripheral surface of the semi-cylindrical member 22 may be brought into contact with each other.

  The rotating brush 21 includes a central shaft 21a and a large number of bristles 21b fixed to the central shaft 21a. The central shaft 21a is rotatably supported by a bearing 24. The bristles 21b extend in the radial direction of the central axis 21a. The central shaft 21a is made of a conductive material such as metal. The bristles 21b have elasticity and are made of a resin such as nylon or polypropylene. A brush contact portion 25 that comes into contact with the bristles 21 b of the rotating brush 21 is provided at the notched end portion of the semicylindrical member 22. The brush contact portion 25 may be configured integrally with the semi-cylindrical member 22 or may be provided separately from the semi-cylindrical member 22. The semi-cylindrical member 22 and the brush contact portion 25 are made of a conductive material such as metal.

  The tip of the brush contact portion 25 is located slightly inward in the radial direction from the inner peripheral surface of the semi-cylindrical member 22. Therefore, when the rotating brush 21 rotates, the tips of the bristles 21b sequentially come into contact with the brush contact portion 25. The brush contact portion 25 bends the bristles 21b by contacting the tips of the bristles 21b of the rotating brush 21 that rotates. The bristles 21b fly the powder upward by the force (reaction) generated when returning to the original shape. The powder spreading unit 20 is electrically connected to the negative electrode of the DC voltage source DC. More specifically, the central shaft 21a of the rotating brush 21 and the brush contact portion 25 are electrically connected to the negative electrode of the DC voltage source DC. Accordingly, an electrostatic field is formed between the object 1 on the belt 11 and the powder spreading unit 20.

  The powder spreading unit 20 includes a scraper 26 that scrapes off the powder that has fallen on the belt 11. The scraper 26 is disposed close to the rotating brush 21, and the powder scraped off from the belt 11 by the scraper 26 falls on the rotating brush 21. The powder falling on the rotating brush 21 is conveyed toward the brush contact portion 25 on the inner peripheral surface of the semi-cylindrical member 22 by the rotation of the rotating brush 21. At this time, the powder is negatively charged due to friction with the rotating brush 21. The powder is caused by the mechanical energy given by the rotation of the rotary brush 21 and the elasticity of the bristles 21b and the action of an electrostatic field formed between the object 1 on the belt 11 and the powder spraying unit 20. , Fly upward toward the object 1 on the belt 11 and adhere to the object 1.

  Next, the overall operation of the electrostatic powder spraying device will be described. First, the motor M1 is driven to rotate the screen brush 3 around its central axis. In this state, the hopper 40 continuously supplies powder to the upper surface of the rotating screen brush 3 (that is, the upper surface of the brush presser 53). The powder falls through the through hole 60 of the screen brush 3 to the upper surface of the screen 2 and is rubbed into the mesh 2 a of the screen 2 by the rotating screen brush 3. The powder is negatively charged by friction with the screen brush 3 and is pushed into the mesh 2 a by the screen brush 3 and moves to the lower surface of the screen 2. A voltage is applied between the screen 2 and the belt 11, whereby the powder travels toward the object 1 on the belt 11.

  The object 1 is conveyed in the horizontal direction by the conveyor 10 and moves across the screen 2. The negatively charged powder is attracted to the object 1 that is electrically connected to the positive electrode of the DC voltage source DC, whereby the powder adheres to the object 1. Depending on the type of powder, the powder may be positively charged when rubbed against the screen 2 with the screen brush 3. When such powder is used, the screen 2 and the powder dispersion unit 20 are connected to the positive electrode of the DC voltage source DC, and the conveyor 10 (that is, the transport plate 13 and / or the belt 11) is connected to the DC voltage source DC. Connected to the negative electrode.

  The relative positions of the screen brush 3 and the screen 2 are fixed, and the screen brush 3 rotates around the drive shaft 5 on the screen 2. As the screen brush 3 rotates, the powder is evenly distributed on the screen 2 and rubbed into the mesh 2 a of the screen 2. Therefore, it is not necessary to move the entire screen brush 3 on the screen 2 in order to smooth the powder. Therefore, the moving mechanism of the screen brush 3 can be made unnecessary, and the entire apparatus becomes compact.

  The relative speed of the screen brush 3 with respect to the screen 2 is small at the center of the screen brush 3 and large at the peripheral edge of the screen brush 3. For this reason, the amount of powder rubbed into the screen 2 at the center of the screen brush 3 is smaller than the amount at the periphery. However, since the object 1 moves across the screen brush 3 and the screen 2 when viewed from above while the powder is being dispersed, the powder uniformly adheres to the object 1.

  The object 1 is further conveyed by the belt 11 to a position above the powder spraying unit 20 arranged on the downstream side of the screen 2. As described above, the powder spraying unit 20 sprays the powder onto the object 1 from below the object 1, thereby attaching the powder to the bottom surface and the lower part of the side surface of the object 1. Since the potential difference between the brush contact portion 25 and the central axis 21a of the rotary brush 21 is 0, no electrostatic field is formed between the brush contact portion 25 and the central axis 21a. Therefore, the powder proceeds toward the object 1 on the belt 11 without being attracted to the central shaft 21a.

  As described above, the powder is spread on the upper surface and the upper side of the object 1 by the screen brush 3 and the screen 2 which are the first electrostatic powder spreader, and the powder which is the second electrostatic powder spreader. The body spraying unit 20 sprays the powder onto the bottom surface and the lower part of the side surface of the object 1. Therefore, the powder can be dispersed over the entire object 1. The object 1 to which the powder adheres is received by the downstream conveyor 100B and further conveyed downstream.

  Examples of the powder scattering object 1 include food products such as buns and industrial products such as cosmetics. In addition, as powders, various powders may be used depending on the application, such as edible powders containing natural or synthetic pigments, cocoa powder, wheat flour, matcha powder, sugar powder, corn starch, or industrial powder. Can be used.

  FIG. 12 is a diagram illustrating a modification of the present embodiment. In this example, a powder cover 70 that receives the powder sprayed from the powder spraying unit 20 is provided so as to cover a part of the belt 11. The powder cover 70 is located above the powder spreading unit 20. The powder cover 70 extends along the belt 11 and has a tunnel-like shape surrounding the object 1 carried by the belt 11. As shown by the arrow in FIG. 12, the object 1 passes through the space formed between the belt 11 and the powder cover 70. FIG. 13A is a cross-sectional view of the powder cover 70, and FIG. 13B is a side view of the powder cover 70. The powder cover 70 has a substantially semi-cylindrical shape. The downstream end of the powder cover 70 protrudes from the belt 11 as shown in FIG.

  A protrusion 71 that disperses the powder is provided on the top of the inner peripheral surface of the powder cover 70. The cross section of the protrusion 71 is an inverted triangle, and as shown by the arrow in FIG. 13A, the protrusion 71 disperses the flow of powder that proceeds from below. Furthermore, a plurality of baffles 72 for retaining the powder in the powder cover 70 are arranged on the inner peripheral surface of the powder cover 70. These baffles 72 are arranged at substantially equal intervals along the longitudinal direction of the powder cover 70.

  The object 1 passes through the upward flow of the powder from the powder spraying unit 20 and the swirl flow of the powder formed in the powder cover 70, whereby the powder is on the bottom surface of the object 1. And adhere to the side. Furthermore, since the powder flow collides with the baffle 72, the powder hardly flows out from the powder cover 70. Therefore, diffusion of the powder into the ambient atmosphere can be prevented. Further, since the powder stays in the powder cover 70 for a long time by the baffle 72, the powder can be adhered to the entire object 1. Note that a powder suction device may be connected to the powder cover 70 in order to reliably prevent the powder from diffusing into the ambient atmosphere.

  FIG. 14 is a view showing a modification of the electrostatic powder spraying device. The electrostatic powder spraying apparatus of this example further includes a lift roller 73 as a lift mechanism that lifts the object 1 on the belt 11 toward the lower surface of the screen 2. The lift roller 73 is disposed below the screen 2 and is rotatably supported by a support member (not shown). The belt 11 is supported from below by a lift roller 73, thereby forming a conveyance path for the object 1 having the top of the lift roller 73 as a vertex. That is, the belt 11 is formed with an ascending inclined portion that is inclined upward toward the lift roller 73 and a descending inclined portion that is inclined downward from the lift roller 73. In FIG. 14, the positive electrode of the DC voltage source DC is connected to the belt 11 via the transport plate 13, but the positive electrode of the DC voltage source DC may be directly connected to the belt 11.

  When the object 1 moved by the belt 11 gets over the lift roller 73, a part of the bottom surface of the object 1 is separated from the belt 11. Therefore, a part of the powder supplied from the screen 2 goes around the bottom surface of the object 1 and adheres to the bottom surface and the lower portions of the side surfaces. Powder is further sprayed by the powder spraying unit 20 on the bottom surface and the lower part of the side surface of the object 1. Therefore, the powder can be dispersed more reliably over the entire object 1. Instead of the lift roller, a belt support member having a curved surface with a smooth upper surface may be used as the lift mechanism.

  FIG. 15 is a view showing an example in which the powder cover 70 shown in FIG. 12 and the lift roller 73 shown in FIG. 14 are combined. As shown in FIG. 15, by combining the powder cover 70 and the lift roller 73 (that is, the lift mechanism), the powder can be more reliably dispersed over the entire object 1.

  Next, another embodiment of the present invention will be described. FIG. 16 is a diagram showing an electrostatic powder spraying device according to another embodiment of the present invention. In FIG. 16, the support member 32 and the support frame 30 are omitted for explanation. As shown in FIG. 16, the powder spreading unit 20 is disposed below the screen 2 and the belt 11. In this embodiment, the belt 11 has a net structure that allows the passage of powder. As the belt 11 having such a net structure, for example, a wire belt knitted with a wire or a net belt can be used. In this embodiment, the transport plate 13 is not provided, and the positive electrode of the DC voltage source DC is connected to the belt 11. A voltage is applied between the belt 11 and the powder spraying unit 20 by a DC voltage source DC.

  The position of the powder spreading unit 20 is below the screen 2. Accordingly, a part of the powder supplied from the screen 2 passes through the belt 11 and falls onto the powder spraying unit 20. The rotating brush 21 receives the powder that has fallen on the powder spreading unit 20 and blows the powder upward. Therefore, powder can be simultaneously spread on the upper surface, the side surface, and the bottom surface of the object 1. In this embodiment, the above-described scraper 26 is not necessary. As shown in FIG. 17, a plurality of powder spreading parts 20 may be arranged below the belt 11 and the screen 2.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention should not be limited to the described embodiments, but should be the widest scope according to the technical idea defined by the claims.

DESCRIPTION OF SYMBOLS 1 Object 2 Screen 3 Screen brush 10 Conveyor 11 Belt 13 Conveying plate 20 Powder dispersion part 21 Rotating brush 22 Semi-cylindrical member 25 Brush contact part 26 Scraper 40 Hopper 70 Powder cover 73 Lift roller (lift mechanism)
DC DC voltage source (DC voltage generator)

Claims (9)

An electrostatic powder spraying device for spraying powder onto an object,
A screen having a mesh;
A screen brush for rubbing the powder into the screen;
A hopper for supplying the powder to the screen brush;
A conveyor disposed below the screen and carrying the object;
A powder spreading part for spreading the powder onto the object from under the object;
A DC voltage source for applying a voltage between the screen and the object, and between the powder spreading unit and the object ;
The electrostatic powder spraying apparatus , wherein the powder spraying unit includes a rotating brush that splashes the powder.   The electrostatic powder spraying apparatus according to claim 1, further comprising a lift mechanism that lifts the object toward the screen. The electrostatic powder spraying device according to claim 1 , wherein the powder spraying unit further includes a semi-cylindrical member in which the rotating brush is accommodated, and a brush contact unit that contacts the bristles of the rotating brush. . The conveyor has a belt on which the object is placed,
The electrostatic powder spraying apparatus according to claim 1 , wherein the powder spraying unit includes a scraper that scrapes the powder from the belt and drops the powder onto the rotating brush. A powder cover for receiving the powder sprayed from the powder spraying unit;
The electrostatic powder spraying device according to claim 1, wherein the powder cover has a shape surrounding the object.   The electrostatic powder spraying device according to claim 1, wherein the powder spraying unit is disposed below the screen.   An electrostatic powder spraying device for spraying powder onto an object,
  A powder spreading part for spreading the powder onto the object from under the object;
  A DC voltage source for applying a voltage between the powder spraying unit and the object;
  The electrostatic powder spraying apparatus, wherein the powder spraying unit includes a rotating brush that splashes the powder.   The electrostatic powder spraying device according to claim 7, wherein the powder spraying unit further includes a semi-cylindrical member in which the rotating brush is accommodated, and a brush contact unit that contacts the bristles of the rotating brush. .   A powder cover for receiving the powder sprayed from the powder spraying unit;
  The electrostatic powder spraying device according to claim 7, wherein the powder cover has a shape surrounding the object.

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