JPH0113570Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a type of paint sprayer in which the atomized charged paint particles are directed toward the object to be coated along the lines of electric force by rotating the rotary atomizer head at high speed and are applied to the object to be coated. This invention relates to an electrostatic spray device.

Conventionally, this type of electrostatic spraying device supports a rotating shaft via a bearing such as a ball bearing or a roller bearing, an air-driven turbine is attached to one end of the rotating shaft, and a rotary sprayer is attached to the other end of the rotating shaft. The rotary atomizing head is attached, and the rotary atomizing head is rotated at high speed by the turbine while applying a high voltage to atomize the paint supplied to the rotary atomizing head. In order to atomize the paint, the rotary jetting head is rotated at high speed, and the paint supplied to the liquid contact surface is made to flow down to the discharge edge as a thin film-like liquid stream due to centrifugal force. The paint is discharged from the discharge edge as liquid threads (cusps), and the liquid threads are further electrostatically atomized to form charged paint particles.

By the way, when liquid paint is atomized into paint particles and applied to an object to be coated, the quality of the coating film formed on the painted surface is determined by the maximum particle size and average particle size of the paint particles. It is known that when the maximum particle size is large, the quality of the coating film is significantly reduced. Therefore, the rotation speed of the rotating atomizing head has a large effect on the particle size, and the higher the rotation speed of the rotating atomizing head, the smaller the particle size can be, which improves the quality of the coating film. can be done.

However, since the conventional technology described above uses ball bearings or roller bearings as means to support the rotating shaft, the rotational capacity is limited to 25,000 to 40,000 rpm in order to prevent seizure of these bearings. .
However, when the rotational speed of the rotary atomizing head is about 40,000 rpm or less, the average particle size of the paint becomes considerably large, and there is a problem that good paint film quality cannot be obtained.

In order to solve these problems, a static air bearing is used as a bearing to support the rotating shaft without contact, and the rotation speed of the rotating atomizing head is increased to about 60,000 to 100,000 rpm. Kaisho
An electrostatic spraying device as shown in Japanese Patent No. 56-115652 is known.

That is, the electrostatic spraying device according to the above-mentioned prior art includes a housing in which a shaft hole is formed in the axial direction and a turbine chamber is formed in the radial direction on one end side of the shaft hole, and a housing in which a shaft hole is formed in the shaft hole of the housing. a rotating shaft fitted into the housing; a turbine loosely fitted into a turbine chamber of the housing and fixed to one end of the rotating shaft;
a rotating atomizing head located outside the housing and fixed to the other end of the rotating shaft; and a rotating atomizing head located around the rotating shaft and provided on the housing to support the rotating shaft in a non-contact state. The thrust air bearing is generally comprised of a radial air bearing and a thrust air bearing located on both sides of the turbine and provided in the housing to support the turbine in a non-contact manner, and for supplying high pressure air to the turbine. Therefore, the rotating shaft is rotated at high speed, and high-pressure air is supplied to the radial bearing and the thrust bearing to support the rotating shaft, while paint is supplied to the rotating atomizing head and paint particles are atomized from the discharge edge. is being done.

In this way, electrostatic spraying devices using static pressure air bearings can achieve more than twice the high speed of rotation compared to devices using ball bearings, roller bearings, etc., and also have a smaller housing. be able to.

By the way, the electrostatic spraying device according to the prior art mentioned above is configured as shown in FIG. 1, for example.
That is, there is a housing 101 containing a turbine and thrust and radial static pressure air bearings, and a housing 101 that is rotatably supported within the housing 101 by the thrust and radial static pressure air bearings and is driven by the turbine. a rotating shaft 102 and a bell-shaped rotating atomizing head 1 fixed to the tip of the rotating shaft 102;
03, and the rotary atomizing head 103 has a hub member 1
04, and an atomizing head main body 105 attached to the hub member 104. And the hub member 10
4 has a liquid contact surface 104A formed therein, and a plurality of paint passages 104B, 104B, . . .
Further, the atomizing head body 105 has a liquid contact surface 10 that thins the paint from each paint passage 104B into a thin film.
5A is formed, the tip of which is a discharge edge 105B. Further, a paint tube 106 is fixed to the housing 101 diagonally, one end of the paint tube 106 is connected to a color change valve 107, which will be described later, and the other end is inserted into the hub member 104 and is connected to the liquid contact surface 104A. It is designed to drip paint.

107 is a color changing valve that supplies paint of A, B,...N colors, air and thinner; 108 is a paint valve; 109 is an on-off valve; 110 is a waste liquid tank; 11
1 is a paint pipe that connects between the color change valve 107 and the paint valve 108; 112 is a paint pipe that connects between the paint valve 108 and the paint tube 106; 113;
A waste liquid pipe connects the paint valve 108 and the waste liquid tank 110, and an on-off valve 109 is inserted in the middle of the waste liquid pipe 113.

When supplying paint to the rotary atomizing head 103, the on-off valve 109 is set to the switching position A, and the paint valve 1
A predetermined paint can be supplied from the color change valve 107 with 08 set as the switching position B. Also, paint pipe 11
1, the paint valve 108 is set to the switching position A, the on-off valve 109 is set to the switching position B, and the color change valve 1 is set to the switching position B.
The paint pipe 111 is cleaned at high speed with high pressure air and thinner from 07. Furthermore, when cleaning the paint pipe 112 and the rotary atomizing head 103, the paint valve 1 is
08 is the switching position B, and these are washed at low speed using low pressure air and thinner from the color change valve 107, and the waste liquid is received by a waste liquid recovery shroud to prevent the waste liquid from scattering inside the painting booth. .

When using the rotating atomizing head 103 having the above-described shape, the rotational speed of the rotating atomizing head 103 can be increased by supporting the rotating shaft 102 with thrust and radial static pressure air bearings. Although the shape of 101 could be made smaller, it still had the following drawbacks.

First, the hub member 104 of the rotating atomizing head 103
In addition, it is necessary to insert the paint tube 106 outside the rotating shaft 102, and since the rotating atomizing head 103 is composed of a hub member 104 and an atomizing head main body 105, the overall shape is or the bell caliber becomes larger. As a result, the spray pattern becomes large, making it unsuitable for so-called flat spraying or spot spraying.

Second, the paint tube 106 is connected to the housing 10
Since it is installed diagonally with respect to 1,
When the electrostatic spraying device is attached to an industrial robot or reciprocator, the paint piping connected to the paint tube 106 gets in the way, making it impossible to paint objects that have narrow areas. It was hot.

Thirdly, since the paint valve 108 is provided outside the housing 101, the paint tube 106
and the paint valve 108 must be connected via a paint pipe 112, and when changing colors, the previous color paint filling inside the paint pipe 112 is not discharged as waste liquid to a waste liquid recovery shroud. must not. For this reason, when the paint pipe 112 is long, the waste liquid recovery shroud provided to cover the rotary atomizing head 103 also needs to be large, and a cylinder for expanding and contracting the shroud is also required, resulting in an increase in the size of the waste liquid recovery mechanism. There are drawbacks.

Fourth, the rotating atomizing head 103 and the paint pipe 112
When cleaning the paint pipe 112, it is necessary to clean at a low speed, but the disadvantage is that the more previous color paint remains in the paint pipe 112, the longer the cleaning time will be.

The present invention was devised in view of the holes in the prior art described above, and an inner cylinder serving as a paint supply passage and a paint discharge passage between the inner cylinder are coaxially inserted into the rotating shaft, and the paint By locating the valve body constituting the valve as close as possible to the rotating atomizing head, the aperture of the rotating atomizing head and the overall shape of the housing can be reduced. It is an object of the present invention to provide an electrostatic spraying device that can improve the cleaning performance of the device and also improve the ease of mounting on industrial robots and reciprocators.

In order to achieve the above object, the feature of the configuration adopted by the present invention is that an outer cylinder is inserted into the rotating shaft in a non-contact state with respect to the rotating shaft, and an inner cylinder is inserted into the outer cylinder, The inside of the inner cylinder is formed as a part of a paint supply passage that supplies paint toward the liquid contact surface of the rotary atomizing head, and the inner cylinder and the outer cylinder are in constant communication with the paint supply passage. A valve body is formed as a part of the paint discharge passage, and is provided in the middle of the paint supply passage to be located near the rotary atomizing head and seated on and off the valve seat, and a valve shaft is inserted into the inner cylinder. One end of the valve shaft is attached to a valve driving device provided in the housing, and the valve body is attached to the other end of the valve shaft.

The present invention will be described in detail below based on the embodiments shown in FIGS. 2 and 3.

In the drawings, reference numeral 1 denotes a cylindrical housing made of a metal body, in which a shaft hole 2 is bored in the axial direction, and a circular turbine chamber 3 is formed in the radial direction at one end of the shaft hole 2. The other end of the shaft hole 2 is open. Reference numeral 4 denotes a hollow rotary shaft made of a metal material that is loosely fitted into the shaft hole 2 with a small gap in the radial direction, and the rotary shaft 4 has a hollow hole 4A in the axial direction. is bored, and its tip is located outside the housing 1 and forms a tapered surface 4B. Reference numeral 5 denotes a disk-shaped turbine made of a metal material loosely fitted in the turbine chamber 3 with a small gap in the axial direction, and the turbine 5 is attached to one end of the rotating shaft 4 by, for example, welding. , is fixed by means such as bolts, and a large number of blades 5A, 5A, . . . are provided on the outer peripheral surface of the turbine 5.

Reference numeral 6 denotes a rotating atomizing head located outside the housing 1 and fixed to the other end of the rotating shaft 4. In this embodiment, the rotating atomizing head 6 is a cylindrical or bell-shaped atomizing head. Here, the rotary atomizing head 6 includes an atomizing head main body 7 that is fitted into the tapered surface 4B of the rotating shaft 4, and a set bolt 8 that screws the atomizing head main body 7 into the tip of the hollow hole 4A of the rotating shaft 4. The inner peripheral surfaces of the atomizing head main body 7 and the set bolt 8 form a liquid contact surface 9 that widens toward the tip. Incidentally, the set bolt 8 has an insertion hole 8A formed in the axial direction for a nozzle mounting member 29, which will be described later.

Reference numeral 10 denotes a radial air bearing located around the rotating shaft 4 and disposed in the housing 1 to support the rotating shaft 4 in a non-contact state with respect to the shaft hole 2; Sleeve-shaped bearings 10A, 10A made of a porous metal material such as sintered metal are fixed to the housing 1 so as to surround the outer periphery of the bearings 4.
and an air chamber 10B located on the outer peripheral surface side of the bearing 10A and formed concentrically with the shaft hole 2. The air bearing 10 is a bearing 10A.
and the air chamber 10B constitute a static pressure air bearing, and as will be described later, the rotating shaft 4 is supported in a non-contact state by blowing out high pressure air supplied to the air chamber 10B from the bearing 10A in the direction of the arrow in the figure. be able to.

Reference numerals 11 and 11 designate thrust air bearings that are located on both sides of the turbine 5 and disposed in the housing 1 in order to support the turbine 5 in a non-contact state with respect to the turbine chamber 3; Annular bearings 11A, 11A made of a porous metal material such as sintered metal are fixed to the housing 1 so as to sandwich both sides of the turbine 5, and annular bearings 11A, 11A are formed in the housing 1 and are located on the back side of the bearings 11A. Air chamber 11B
It is composed of. Each of the air bearings 11 also constitutes a static pressure air bearing, and by blowing out the high pressure air supplied to the air chamber 11B in the direction of the arrow in the figure, the turbine 5 can be supported in a non-contact state.

Reference numeral 12 denotes a bearing air passage formed in the housing 1. One end of the air passage 12 is connected to a pressurized air source (not shown), and the other end is connected to each air bearing 10, 1.
1 air chamber 10B, 11B. 1
3 is an exhaust passage; one end of the exhaust passage 13 opens into the shaft hole 2 in the middle of each air bearing 10, 11, and the other end is connected to a muffler 14 provided in the housing 1. Reference numeral 15 designates a turbine driving air passage formed in the housing 1. One end of the air passage 15 is connected to a pressure source, and the other end serves as a nozzle opening facing the front surface of the blade 5A of the turbine 5. Here, by injecting high-pressure air toward the blades 5A of the turbine 5, the turbine 5 can be rotated at a high speed of 60,000 to 100,000 rpm together with the rotating shaft 4 and the rotating atomizing head 6.

Further, reference numeral 16 denotes a rear bracket made of a metal body fixed to one end side of the housing 1, and the rear bracket 16 also constitutes a part of the housing 1. A bottomed hole 17 is bored in the rear bracket 16 in the axial direction, and the bottomed hole 1
A packing hole 18 is bored on the opposite side from 7, and a paint supply passage 19 and a paint discharge passage 20 are formed in the radial direction. Reference numeral 21 denotes a cylinder receiving member inserted into the bottomed hole 17, and the cylinder receiving member 21 has a small diameter portion 21A on the axially proximal end side along the axial direction of the cylinder receiving member 21.
, a relatively long medium diameter portion 21B from the small diameter portion 21A toward the distal end, and a large diameter portion 21C located on the distal end side.
Three stages of mounting holes are drilled, and at positions corresponding to the small diameter part 21A and the medium diameter part 21B, a paint supply hole 22 and a paint discharge hole are respectively communicated with the paint supply passage 19 and the paint discharge passage 20. A plurality of holes 23 are bored in the radial direction.

24 is an inner cylinder inserted in the axial direction into the hollow hole 4A of the rotating shaft 4, and 25 is an outer cylinder inserted into the hollow hole 4A so as to be coaxial with the inner cylinder 24. It is loosely fitted into the hollow hole 4A with a minute gap between it and the hollow hole 4A. One end of the inner cylinder 24 is fitted into the small diameter portion 21A of the cylinder receiving member 21, and the other end extends to the vicinity of the tip of the rotating shaft 4. Further, one end of the outer cylinder 25 has a large diameter portion 21C.
The other end similarly extends to the vicinity of the tip of the rotating shaft 4.

Reference numeral 26 denotes another cylinder receiving member located on the tip side of the rotating shaft 4, and the outer peripheral side of the cylinder receiving member 26 has a small diameter portion 26A into which the inner cylinder 24 is fitted, and a paint discharge passage 33 which will be described later together with the outer cylinder 25. A small and medium diameter portion 26 forming a part of
B, a large medium diameter portion 26C into which the outer cylinder 25 is fitted,
A large diameter portion 26D is formed which is loosely fitted into the inner end of the medium diameter hole 4A of the rotating shaft 4. On the other hand, the cylinder support member 26
The inner peripheral side is a small diameter hole 2 into which a valve shaft 36 (to be described later) is inserted.
6E, and a medium diameter hole 26 forming a valve chamber 28, which will be described later.
F, a valve seat 27 and a nozzle mounting member 29, which will be described later.
The large diameter hole 26G is fitted into the large diameter hole 26G. 2
Reference numeral 7 denotes a valve seat inserted into the recess of the medium-diameter hole 26F of the cylinder receiving member 26, and 28 a valve defined between the valve seat 27 and the medium-diameter hole 26F. It is a room. Reference numeral 29 denotes a nozzle mounting member fitted into the large diameter hole 26G of the cylinder support member 26, and the nozzle mounting member 2
One end of the valve seat 9 holds the valve seat 27, and the other end is loosely fitted into the insertion hole 8A of the set bolt 8. A nozzle 30 is fixed to the tip, and the nozzle 30 sprays paint onto the surface in contact with the liquid. A nozzle opening 30A is formed. A paint passage 31 is formed in the axial direction of the nozzle mounting member 29. One end of the paint passage 31 communicates with the valve chamber 28 via the valve seat 27, and the other end communicates with the nozzle 30.

Thus, a paint supply passage 32 is formed in the inner cylinder 24, and one end of the paint supply passage 32 is connected to the paint supply passage 19 through the paint supply hole 22 of the cylinder support member 21.
The other end is connected to the small diameter hole 2 of the cylinder receiving member 26.
It communicates with the valve chamber 28 via 6E. On the other hand, a paint discharge passage 33 is formed between the inner cylinder 24 and the outer cylinder 25, and one end of the paint discharge passage 33 is connected to the paint discharge passage 20 through the paint discharge hole 23 of the cylinder support member 21.
The other end is in constant communication with the valve chamber 28 via a communication hole 34 formed in the cylinder receiving member 26.

35 is a valve body located in the valve chamber 28 and seats on and off the valve seat 27; 36 is a valve shaft loosely fitted in the inner cylinder 24; one end of the valve shaft 36 is inserted into the packing hole 18 of the rear bracket 16; The valve shaft 36 protrudes outside the rear bracket 16 via a packing 37 and a packing retainer 38, and the other end of the valve shaft 36 is fixed to the valve body 35 by loosely fitting into the small diameter hole 26E of the cylinder support member 26. There is.

39 is a valve drive device fixed to the rear bracket 16, and the valve drive device 39 has a casing 40,
A cylinder 41 formed within the casing 40
and a piston 42 that is slidably provided within the cylinder 41 and to which one end of the valve shaft 36 is fixed.
In order to bias the piston 42 in the direction in which the valve body 35 closes, a spring 44 is stretched between the piston 42 and the cap 43, and a pressure chamber is defined in the cylinder 41 by the piston 42. 45, and a valve control air passage 46 that supplies valve control air to the pressure chamber 45.

Furthermore, 47 is an air ring provided on the front end side of the housing 1, and the air ring 47 has an annular groove 48 formed therein and a large number of air jet holes for jetting shaving air from the back surface of the rotary atomizing head 6. 49, 49... are drilled. The air ring 47 is connected to a pressurized air source via a shaping air inflow passage 50.

In the figure, reference numeral 51 indicates a mounting bracket fixed to the rear bracket 16, 52 indicates a high voltage cable connected to the mounting bracket 51, and the high voltage cable 52 is connected to a high voltage generator. Reference numeral 53 indicates a mounting bracket for mounting on an industrial robot, reciprocator, etc.

Figure 3 is a paint system diagram used in this example.
55 is a paint pipe that connects the color change valve 54 and the paint supply passage 19 of the rear bracket 16, and 56 is a paint discharge valve. A waste liquid pipe 58 connecting the passage 20 and the waste liquid tank 57 indicates an on-off valve provided in the middle of the waste liquid pipe 56.

The present embodiment is constructed as described above, and its operation will now be described.

First, from the bearing air passage 12 to each air bearing 1
High pressure air is supplied to the air chambers 10B and 11B of 0 and 11, and the high pressure air is ejected from the bearings 10A and 11A in the direction of the arrow in the figure. As a result, the rotating shaft 4 is held in a non-contact state in the radial direction by the radial air bearing 10, and the turbine 5 is held in a non-contact state in the axial direction by the thrust air bearing 11.

In this state, when high pressure air is supplied from the turbine drive air passage 15 toward the front surface of the blades 5A of the turbine 5, the turbine 5 rotates at high speed in the direction of arrow R in the figure together with the rotating shaft 4 and the rotating atomizing head 6. During this time, most of the exhaust from each of the air bearings 10, 11 and the turbine 5 is discharged into the atmosphere from the exhaust passage 13 via the muffler 14.

On the other hand, from the high voltage generator to the high voltage cable 52
For example, if you supply a high voltage of -90 [KV] to
Housing 1 made of metal material is rear bracket 1
It is charged to -90 [KV] along with 6. At this time, the rotating shaft 4 and the turbine 5 are in a non-contact state with the housing 1, but the rotating shaft 4 is loosely fitted into the shaft hole 2 with a small gap, and the turbine 5 is also fitted into the shaft hole 2. It is merely loosely fitted into the chamber 3 with a small gap. As a result, the housing 1 is charged to a high voltage, causing dielectric breakdown in the minute air layer interposed between the shaft hole 2 and the rotating shaft 4 and between the turbine chamber 3 and the turbine 5. , the rotating shaft 4 and the turbine 5 become -90 due to the discharge phenomenon.
Charged to [KV]. Thus, the rotating atomizing head 6 is also charged to this high voltage via the rotating shaft 4.

On the other hand, when the valve control air is not supplied from the valve control air passage 46, the valve body 35 is moved to the valve seat 2 by the spring 44 via the valve shaft 36 inserted into the inner cylinder 24.
7 and keep the on-off valve 58 closed. In this state, when paint of color A, for example, is supplied from the color change valve 54, the waste liquid is passed through the paint pipe 55, the paint supply passages 19, 32, the valve chamber 28, the communication hole 34, and the paint discharge passages 33, 20. It flows out toward the pipe 56 and fills the interior thereof.

Next, when valve control air is supplied from the valve control air passage 46 to the pressure chamber 45, the piston 42 moves toward the valve shaft 36.
At the same time, it is displaced to the right in the figure against the force of the spring 44, and is separated from the valve body 35 and the valve seat 27. As a result, the paint from the paint supply passage 32 is transferred from the valve chamber 28 to the valve seat 2.
7. The paint is ejected from the nozzle opening 30A of the nozzle 30 toward the liquid contact surface 9 through the paint passage 31 in the nozzle mounting member 29. As a result, the centrifugal force generated when the rotary atomizing head 6 rotates at high speed forms an extremely thin film, which is sprayed as liquid threads from the discharge edge of the atomizing head main body 7, becoming electrostatically atomized charged paint particles. The paint particles fly along the electric lines of force formed between the rotary atomizing head 6 and the object to be coated, and are applied to the object to be coated.

At this time, the charged paint particles tend to form an expanded spray pattern due to the centrifugal force of the rotating atomizing head 6, the air pumping phenomenon, and the like. Therefore, in this embodiment, by supplying shaping air to the shaping air inflow passage 50, the shaping air is blown out from each air injection hole 49 of the air ring 47 toward the object to be coated, thereby forming a paint spray pattern.

Furthermore, in order to spray the next color paint, for example, the B color paint, it is necessary to wash all the areas to which the A color paint has adhered. Therefore, the supply of valve control air to the pressure chamber 45 is stopped, and the spring 44 causes the valve body 35 to
is seated on the valve seat 27, and the on-off valve 58 is opened. Then, air and thinner are sequentially supplied from the color change valve 54 to the paint pipe 55 and the paint supply passage 1.
9, 32, valve chamber 28, paint discharge passages 33, 20, etc., and remove thinner waste liquid etc. from waste liquid pipe 5.
6. Discharge to the waste tank 57 via the on-off valve 58. At this time, high-speed cleaning can be performed by supplying air and thinner at high pressure.

Next, the valve seat 27, the paint passage 31, the nozzle 3
0. In order to clean the liquid contact surface 9 of the rotary atomizing head 6, the valve drive device 39 opens the valve body 35 again, closes the on-off valve 58, and removes thinner from the color change valve 54. , air is sequentially supplied to these interiors at low pressure to perform cleaning. At this time, cleaning is performed while rotating the rotary atomizing head 6, but if this rotation is too fast, the waste liquid will be scattered around, so the rotational speed of the rotary atomizing head 6 is set to 5000 to 10000 rpm.

After all cleaning operations are completed, paint with B color can be applied in the same manner as described above.

In this embodiment, the paint supply passage 32 can be formed directly in the inner cylinder 24 inserted through the rotation shaft 4 serving as the center of rotation, and the nozzle 30 is positioned at the center of the rotary atomizing head 6. be able to. Therefore, when radial and thrust static pressure air bearings 10 and 11 are used as bearings, in addition to the advantage that the shape of the housing 1 can be made smaller compared to those using ball bearings or roller bearings. , rotation axis 4
Since the paint supply passage 32 is formed inside the housing 1 using the so-called "center feed system", the shape of the housing 1 can be further reduced in size.

Further, since the nozzle 30 can have the nozzle opening 30A directly opened almost at the center of the rotating atomizing head 6, the shape of the rotating atomizing head 6 can be simplified compared to the prior art shown in FIG. Not only can the diameter be made small, but the cleaning performance can be improved and it can be applied to spot blowing, etc.

On the other hand, an outer cylinder 25 is provided inside the rotating shaft 4 on the outer circumferential side of the inner cylinder 24 in a non-contact state with the rotating shaft 4, and a paint discharge passage 33 is formed inside and between the outer cylinders 24 and 25. The supply passage 32 and the paint discharge passage 33 are located in the vicinity of the rotary atomizing head 6 and constantly communicate with each other through the communication hole 34, and form a valve chamber 28, in which the rotary atomizing head is located. Since the valve body 35 for opening and closing the paint passage 31 to the paint passage 31 is disposed, the distance of the paint passage 31 can be made as short as possible. As a result, the areas from the color change valve 54 to the paint pipe 55, the paint supply passages 19, 32, the valve chamber 28, the paint discharge passages 33, 20, etc. are designated as high-speed cleaning sections.
Can be cleaned in a short time using high pressure thinner and air. On the other hand, only the paint passage 31 and the rotary atomizing head 6, which have extremely short distances, need to be cleaned with low-pressure air or thinner as a low-speed cleaning section, which can significantly shorten the cleaning time. There is no need to provide one.

Furthermore, as a result of the above, since only a small amount of residual paint, thinner, etc. are discharged as waste liquid into the coating booth, the interior of the coating booth is not contaminated, and the quality of coating can be improved.

In the above-described embodiments, the rotary atomizing head 6 was described as being cylindrical or bell-shaped, but a so-called disk-shaped or circular plate-shaped one may also be used. Furthermore, the object to which the present invention is applied is not limited to paint spraying equipment, but may also be spray granulation equipment, spray drying equipment, flash drying equipment, etc.

The electrostatic spraying device according to the present invention is as described in detail above, and includes a paint supply passage and a paint discharge passage formed within the rotating shaft, and a valve chamber formed near the rotating atomizing head and a valve body disposed therein. However, since the valve body is moved to and from the valve seat by a valve shaft that fits loosely in the inner cylinder, the shape of the housing and rotating atomizing head can be made smaller.
Since there are no paint tubes near the rotary atomizing head, they do not interfere with painting operations, making it suitable as an electrostatic spraying device for industrial robots and reciprocators. Furthermore, the valve element of the paint valve that supplies paint to the rotating atomizing head is located as close as possible to the rotating atomizing head, reducing cleaning time and eliminating the need for a waste liquid recovery shroud. It is possible to achieve the following effects.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of the main part of an electrostatic spraying device according to the prior art, including the paint system, Fig. 2 is a longitudinal cross-sectional view of the electrostatic coating device according to the present invention, and Fig. 3 is a paint system diagram of the present invention. be. DESCRIPTION OF SYMBOLS 1... Housing, 2... Shaft hole, 3... Turbine chamber, 4... Rotating shaft, 5... Turbine, 6... Rotating atomization head, 9... Liquid contact surface, 10... Radial air bearing, 11... Thrust air bearing, 12... Bearing air passage, 13... Exhaust passage, 15... Turbine drive air passage, 16... Rear bracket, 1
9, 32... Paint supply passage, 20, 33... Paint discharge passage, 21, 26... Tube support member, 22... Paint supply hole, 23... Paint discharge hole, 24... Inner cylinder,
25... Outer cylinder, 27... Valve seat, 28... Valve chamber, 2
9... Nozzle mounting member, 30... Nozzle, 31...
...Paint passage, 34...Communication hole, 35...Valve body, 3
6... Valve shaft, 39... Valve drive device, 47... Air ring, 52... High voltage cable.

Claims (1)

[Scope of utility model registration request] A housing having a shaft hole formed therein in the axial direction and a turbine chamber formed in the radial direction at one end of the shaft hole, a rotating shaft loosely fitted in the shaft hole of the housing, and a turbine chamber of the housing. a turbine loosely fitted into the housing and fixed to one end of the rotating shaft; a rotating atomizing head located outside the housing and fixed to the other end of the rotating shaft, one surface of which is a wetted surface; radial air bearings located around the rotating shaft and provided in the housing to support the rotating shaft in a non-contact manner; and radial air bearings located on both sides of the turbine to support the turbine in a non-contact manner. and a thrust air bearing provided in the housing, an outer cylinder is inserted into the rotating shaft in a non-contact state with respect to the rotating shaft, and an inner cylinder is inserted into the outer cylinder. The inside of the inner cylinder is formed as a part of a paint supply passage for supplying paint toward the liquid contact surface, and a paint discharge passageway is formed between the inner cylinder and the outer cylinder and permanently communicates with the paint supply passage. A valve body is formed as a part of the passage, and is located in the vicinity of the rotary atomizing head in the middle of the paint supply passage and seats on and off the valve seat, and a valve shaft is inserted into the inner cylinder, An electrostatic spraying device characterized in that one end of the valve shaft is attached to a valve driving device provided in the housing, and the valve body is attached to the other end of the valve stem.