JPS6174666A - Electrostatic painting device - Google Patents

Abstract

PURPOSE:To obtain the titled electrostatic painting device wherein rotary atomization and air atomization can be freely changed over to each other by switching over a cup-shaped head from high to low speed or reversely, and spouting shaving air at high speed and atomization air at low speed. CONSTITUTION:Many shaving air ejection ports 13 and atomization air ejection ports 14 are opened on respective circumference at intervals to surround the periphery of the leading end part of a cup-shaped head 5. In rotary atomization, valves 22 and 26 are closed, valves 19 and 27 are opened, the cup-shaped head 5 is rotated at high speed by an air motor 4, and air is spouted from the air ejection port 13. Besides, in air atomization, the valve 27 is closed, the valves 22 and 26 are opened, the cup-shaped head 5 is rotated at low speed by the air motor 4, and atomization air is spouted from the air ejection port 14. Rotary atomization and air atomization are carried out with one electrostatic painting device in this way.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an electrostatic coating device that applies voltage between an object to be coated and a coating material to perform coating, and more specifically relates to a rotary atomization coating device. Can it be used for both air atomization and air atomization? +) This relates to an electrostatic coating device that is configured to have the following characteristics.

(Prior Art) An electrostatic coating device is equipped with a cup-shaped head that is driven to rotate, and the paint supplied to the center of rotation is discharged from the tip by centrifugal force. The paint is charged so that it has a potential difference with respect to the object to be coated. There are two types of devices equipped with such a cup-shaped head: those for rotary atomization and those for air atomization, and their use was determined depending on the type of paint.

That is, in the case of a rotary atomizer, the cup-shaped head is rotated at a high speed of, for example, 8,000 to 12,000 revolutions per minute, and the centrifugal force rotates the paint at 40 to 70 rpm.
0. While atomizing the paint to a certain level (for atomization), shooping air is blown out from around the rotary atomizer to shape the release pattern of the ejected paint. In addition, in the case of air atomization, the cup-shaped head is rotated at a low speed of, for example, 3,000 to 4,000 revolutions per minute, and the coating 1 is rotated at 300 to 400 revolutions per minute by the action of centrifugal force.
After making it thin to about 00 JL, the paint released from the cup-shaped head is atomized (for atomization) to 40 to 70 particles by the atomizing air that is blown out from around the cup-shaped head. There is. When using, for example, a Nlind-based paint, the coating is performed by rotary atomization, and when a Metalink-based paint is used, the painting is performed by air atomization. In this way, the reason why rotary atomization and air atomization are used depending on the type of coating is that, for example, when metal-link paint is rotary atomized, the metal in the coating is This is because agglomeration occurs and the painted surface becomes completely darkened, so air atomization has no choice but to be used.

In this way, using air atomization and rotary atomization depending on the type of coating 4 requires separate painting equipment for air atomization and rotary atomization (installation cost). Not only does this increase in size, but each time the type of coating 1 is changed, the arrangement must be changed between air atomization and rotary atomization, making so-called setup work extremely troublesome. In particular, recently there are many objects that can be coated with different types of paint on one line, resulting in fAe, and this mixed flow of objects is very large, such as the automatic Ichikawa POD. In such cases, it is necessary to use multiple rotary atomization devices or multiple air atomization devices at the same time.
Problems such as those described above become more obvious.

(Object of the invention) The present invention has been made in consideration of the above circumstances, and
Electrostatic coating with a camp-shaped head that can be used for both rotational atomization and air atomization, in other words, it is possible to freely switch between rotational atomization and air atomization. The purpose is to provide equipment.

(Structure of the Invention) In order to achieve the above-mentioned object, the present invention basically consists of rotating the cup-shaped head at high speed and low speed depending on whether it is for rotary atomization or for air atomization. On the other hand, the air jet, that is, the shaping air jet necessary for rotational atomization in which the cup-shaped head is rotated at high speed, and the atomizing air jet necessary for air atomization in which the cup-shaped head is rotated at low speed. and,
This is done in accordance with this high-speed rotation or low-speed rotation.

11 Specifically, in a device that performs painting while applying a voltage between the object to be coated and the paint, it is equipped with a cup-shaped head that is rotationally driven by a rotary motor, and the paint is supplied to the center of rotation of the cup-shaped head. a paint ejector that discharges the paint from the tip of the cup-shaped head by a remote force; and a rotary motor control device that switches the rotation of the rotary motor between high-speed rotation for rotary atomization and low-speed rotation for air atomization. and a shoeing air outlet disposed around the cup-shaped head, at least when the rotary motor is rotated at high speed, air is blown out from the shoeing air outlet, and the cup-shaped head is A pattern shaping air blowing device for controlling the pattern of paint discharged from the tip, and an atomizing air blowing port disposed around the cup-shaped head, when the rotary motor is rotated at a low speed. The present invention further includes: an atomizing air blowing device that blows air from the atomizing air blowing port to atomize the paint discharged from the tip of the cup-shaped head.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a cylindrical main body, and a cylindrical rotating shaft 3 is rotatably disposed and held in a hollow portion 2 of the main body. This rotary shaft 3 is driven by an air motor 4 as a rotary motor installed several times at the rear end of the main body 1, and at the front end of the rotary shaft 3 there is a As shown, the cup-shaped heads 5, called so-called bells, are concentrically screwed together and integrated.

The cup-shaped head 5 is located within a storage section 6 having a substantially semicircular cross section formed on the front end side of the main body l, and its front surface is
The curved surface gradually moves forward as it goes radially outward from the center of rotation. As shown in detail in FIG. 2, this cup-shaped head 5 has a tapered communication 1-17 formed at its center of rotation, and the rotating shaft 3 is fitted into this lower communication portion. Nozzle lO
4 is supplied through the gap 8 between the nozzle 10 and the nozzle 10 or through the passage formed in the nozzle 10. Further, the cup-shaped head 5 is provided with a disc-shaped flow dividing plate 9 on the front surface of the communication lower, and is provided inside the rotary shaft 3 to open and close the communication lower by facing the communication 1-'7. Two consecutive nozzles 10 are disposed so as to be freely displaceable in the front-rear direction. The 4-layer supply to the lower communicating part (the same applies to the supply of cleaning thinner when changing colors) is carried out through the pipe 1 connected to the connection part 8a provided at the rear end of the air motor 4.
1, and also communication by nozzle lO [17
The connection rl provided at the rear end of the air motor 4 is opened and closed.
This is performed by an actuator (not shown) in response to the air supply υ1 from the pipe 12 connected to the pipe 10a.

The front end of the main body 1 surrounds the tip of the cup-shaped head 5, and as shown in FIG. A large number of air jet ports 14 are opened at intervals in the circumferential direction. Of the two air jet ports 13 and 14, the air jet port 13 shapes the paint discharge pattern during rotational atomization, and its jet direction is directed toward the front of the main body 1 (cup-shaped head 5). It is oriented S so as to gradually expand outward in the radial direction (see the dashed-dotted line arrows in FIGS. 1 and 2). In addition, the air jet 114 is directed toward the center in the radial direction as it moves toward the front of the main body (cup-shaped head 5). (See dashed arrows in Figures 1 and 2). Of course, both air jets 113 and 14 are connected to dedicated air supply devices, which will be described later, via air supply passages 15 or 16, respectively.

The air supply path 15 for the shaping air is connected to a pipe 1 connected to a connecting portion 15a provided at the rear end of the air motor 4.
7 to the air tank 18, and this piping 17
An on-off valve 19 is connected in the middle. The air supply path 16 for air atomization is connected to an air tank 21 via a pipe 20 connected to a connecting portion 16a provided at the rear end of the air motor 4. ? 22 are connected. Of course, both air tanks 1 above
8.21, relatively low-pressure air (for example, 0.5 kg/cm2) from the shaping river is stored in the air tank 18, and relatively high-pressure air (for example, 4 kg/cm2) for air atomization is stored in the air tank 21. ~5kg/cm2) of air is stored.

The rotation speed of the air motor 4 is changed according to the supplied air pressure, and in order to change the rotation speed of the air motor 4, a common pipe 23 is connected to the connection portion 4a.
is connected. This common pipe 23 is branched into two in the middle, one branch pipe 23a is connected to an air tank 24, and the other branch pipe 23b is connected to an air tank 25. , opening/closing 4 (26
Alternatively, 27 are connected. Of the two air tanks 24 and 25, the air motor 4 is rotated at a low speed (for example, 3.0 per minute) suitable for air atomization.
00 rotations) and low-pressure air (e.g. 0.5 kg).
/cm2) is stored in the air tank 25, and the air motor 4 is rotated at a high speed suitable for four-way frosting (for example, 9/cm2).
．． 000 rpm) with high pressure air (for example, 4 kg/
Cm2) is stored.

Next, the operation of the above configuration will be explained separately for the case where rotational atomization is performed and the case where air atomization is performed.

(2) In the case of rotary atomization, for example, when painting is performed using a solid paint 11, the on-off valves 22, 26 are closed, while the on-off valves 19.
27 is considered open. As a result, the air motor 4, that is, the cup-shaped head 5 is rotated at high speed for rotary atomization, and
Shuping air is ejected from the air ejection port 13 as shown by the dashed line arrow in FIGS. 1 and 2. Therefore, as shown by the solid line arrows in FIGS. 1 and 2, the cup-shaped head 5
The paint supplied from the communicating lower to the rotational center of the cup-shaped head 5 flows outward in the radial direction from the front surface of the cup-shaped head 5 due to the action of centrifugal force, and is directed from the tip toward the object to be coated. released. Of course, the paint discharged from the cup-shaped head 5 is sufficiently atomized (rotational atomization) because the cup-shaped head 5 is rotated at high speed.

■In the case of air atomization For example, when applying metallic paint,
On-off valve 27 is closed, while on-off valve 22.26 is opened. As a result, the air motor 4, that is, the pump-shaped head 5, is rotated at a low speed suitable for air atomization, and the air for atomization is discharged from the air outlet 14 as indicated by the broken line arrow in FIGS. 1 and 2. It is squirted like that. Therefore, although the linear paint ejected from the cup-shaped head 5 is not sufficiently atomized compared to the case of rotary atomization, it is sufficiently atomized by the action of the atomizing air and then applied to the object to be coated. I will be heading to. Note that the on-off valve 19 may be open or closed (
In the case of air atomization, air for shoeing is not necessarily required, but air for shoeing can also be used).

Here, the opening or closing of the on-off valves 19, 22, 26, and 27 associated with the switching between rotary atomization and air atomization as described above is automatically performed by a control circuit (not shown). However, these on-off valves 19, 22, 26, 27 are explosion-proof if installed in or near the painting atmosphere.
- Air actuated, or electromagnetic if it can be installed in a location where special considerations for explosion protection are not required. Of course, the paint is charged while flowing through the cup-shaped head 5, and a predetermined potential difference is applied to the object to be coated.

(Effects of the Invention) As is clear from the above description, the present invention has a cup-shaped head that can be used for both rotational atomization and air atomization, and enables rotary atomization and air atomization to be performed in the same electrostatic coating. Since it can be selectively switched and used in the equipment, installation costs are significantly reduced compared to conventional systems that require separate electrostatic coating equipment for rotary atomization and air atomization. be able to. Additionally, when switching between rotary atomization and air atomization, there is no need to rearrange the electrostatic coating device itself.
Changeover work between rotary atomization and air atomization can be performed smoothly in a short time.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram showing one embodiment of the present invention. FIG. 2 is an enlarged sectional view of the main part of FIG. 1. Figure 3 is a half-simplified front view of the cup-shaped head and its surrounding parts, seen from the front side. 4: Air motor (rotating motor) 5: Cup-shaped head 13: Air outlet for shoeing 14: Air outlet for atomization 18: Air tank (for shoeing) 21: Air tank (for atomization)

Claims (1)

[Claims] (1) A device that performs painting while applying a voltage between the object to be coated and the paint, which is equipped with a cup-shaped head that is rotationally driven by a rotary motor, and the paint that is supplied to the rotational center of the cup-shaped head is a paint ejector that discharges paint from the tip of the cup-shaped head by centrifugal force; a rotary motor control device that switches the rotation of the rotary motor between high-speed rotation for rotary atomization and low-speed rotation for air atomization; A shoeing air outlet is provided around the cup-shaped head, and at least when the rotary motor is rotated at high speed, air is blown out from the shoeing air outlet and from the tip of the cup-shaped head. A pattern-shaping air blowing device for controlling the discharge pattern of the paint to be discharged; and an atomizing air blowing port disposed around the cup-shaped head; An electrostatic coating device comprising: an atomizing air blowing device that blows air from an air blowing port to atomize paint ejected from the tip of the cup-shaped head.