JPS5884068A - Airless electrostatic painter - Google Patents

Abstract

PURPOSE:To form stable electric fields with accelerated ionization and improved counter electrode efficiency by providing an electrostatic charging electrode and an electric field electrode in the opening part of a spray nozzle, and providing a counter electrode of a projecting shape in the position near the electric field electrode. CONSTITUTION:An electrostatic charging electrode 24 which receives the supplies of high voltage and discharges electrostatic charge, an electricity receiving electrode 26 which receives the discharge from the electrode 24 by crossing the paint films sprayed from a nozzle port 20, and a floating electrode 25 of an electric field electrode 27 which extends forward from the electrode 26 are provided at the preceding spraying part. Further, a projecting part 14a which concentrates electric fields is formed as a counter electrode in the position, such as a gun handle part 14 or the like as near the electrode 27 as possible. Sprayed paint is accelerated of ionization by the discharge from the electrode 24 to the electrode 25. The electrode 25 forms the stable electric fields between the projecting part 14a of the counter electrode and a substrate, thus providing a much stable electrostatic effect.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an airless electrostatic coating device, and more specifically, a convex portion is provided at a position as close as possible to the electric field electrode at the tip of the conductive handle portion that serves as the counter electrode of the airless electrostatic gun. This invention relates to an airless electrostatic coating device that can maintain stable performance by increasing the effectiveness of the electric field electrode provided at the tip of the spray nozzle by making it easier to concentrate the electric field.

Generally, in electrostatic painting, a high voltage applied to an electrode at the tip of a nozzle discharges to a nearby conductive object (grounded object), and the closer the distance to the conductive object, the greater the amount of discharge. Therefore, the larger the amount of discharge, the more highly ionized the gas near the tip of the electrode becomes, and the more charges the paint particles passing near it, the stronger the electric field becomes. (surrounding effect) increases.

However, in general, in order to obtain an electrostatic effect, the distance between the tip electrode of the electrostatic gun and the object to be coated must be around 80α, and...
・Since the distance between the dots 4 and 4 is not constant during painting, the amount of discharge to the object to be coated becomes extremely unstable. For this reason, a method has conventionally been adopted in which a counter electrode is provided at the rear of the electrostatic gun, and a stable discharge is performed from the electrode at the tip toward the counter electrode to maintain the electrostatic effect at all times.

However, this type of gun usually does not.

Since the conductive body of the handle portion is used as a counter electrode, sufficient discharge does not take place, which poses a problem in accelerating electrostatic effects. Of course, if the conductive part of the nozzle is brought closer to the electrode, the amount of discharge will increase, but of course the internal discharge through the paint passage will increase, and the potential of the electrode at the tip will decrease (and the electrostatic charge will decrease). The effect will not be as expected.

In view of the above-mentioned circumstances, the present invention provides a convex portion on the conductive portion of the electrostatic gun node that serves as the counter electrode, thereby promoting discharge from the tip electrode toward the counter electrode, and discharging the charge at the tip. By making the electrode a combination of a charged electrode and a floating electrode, discharge to the floating electrode is promoted and the ionization region generated near the electrode at the tip is strengthened.

Therefore, the electrostatic effect is enhanced.

The present invention will be explained below with reference to the drawings of the embodiments.

The airless electrostatic gun 1 has a barrel part 2 made of insulating material and a conductive material.
-/The barrel part 2 has a dollar part 8 and a tip atomizing part 4 provided at the tip of the barrel part 2.

A paint passage 5 runs vertically through the I: section, and a needle valve 6 is connected to the trigger 7.
At the bottom of the barrel portion 2 is an L-shaped casing 10 made of an insulating material, with a high resistance element 8 cast at the tip and a high voltage cable insertion hole 9 formed at the other end.
is fitted over the lead portion 8 and the electrical passage portion 11
is provided within the gun barrel portion 2 and separated from the paint passage 5.

Furthermore, the handle portion 8 is made of a conductive material.

A hook portion 12 is provided protrudingly from the F of the handle portion 8.
:, is fixed to the gun barrel part 2 at fll and is integrally formed and soldered. )・The lower S of the handle s8 contains the other side of the L-shaped casing 10 made of insulating material fitted into the front barrel part 2,
A high voltage cable 18 connected to a high voltage generator (not shown) is inserted into the high voltage cable insertion hole 9 of the L-shaped casing 10.

14 is a metal paint pipe that also serves as a safety guard for the trigger 7; its base end is fixed to the base end of the handle part 8 with a conductive binding plate 15; The part 2 is connected to a joint 6 provided on the side of the nozzle part 8 through the side of the barrel part 2 from below, and the paint is sent from the joint 6 through the sleeve 17 to the paint passage 51m. It will be done. 18 is a needle press, and 19 is a needle press spring.

In addition, the tip atomizer s4 provided at the tip of the gun barrel e2 has a tip stand 22 fitted with a nozzle tip 21 having a spray nozzle opening 2G in the center, and is attached to the gun barrel 2 by a force <, g3, tXX. A charging electrode 24 is provided on the foot stand 22 in a protruding position slightly in front of the nozzle tip 21 and slightly away from the injection axis a, and a charging electrode 24 is provided extending from the charging electrode 24 across the paint injection axis a. Floating electrodes 25 on the snow facing each other
has been established. The floating electrode δ is a power receiving electrode 26 which serves as a power receiving portion with a disk-shaped portion facing the charging electrode 24.

A part of it extends forward to create a pin-shaped electric field! A pole 27 is formed and maintained in an electrically floating state, and high voltage is discharged from the charging electrode 24 to the receiving electrode 26 which is very close to it, and is further applied from the tip of the electric field electrode 27 extending forward from the receiving electrode 26. The charged electrode 24 generates a discharge between the coating material and the gun nozzle part 8, which serves as a counter electrode, and forms an electric field. "The conductive ring 2B on the rear surface of the stand 22 contacts the tip 29a of the electrical passage 29 protruding from the tip of the gun barrel 2 to maintain an energized state, and the conductive ring 28 electrically connects the charging electrode 24. It is connected.

The electrostatic airless gun of the present invention is constructed as shown below, in which a conductive ) / dollar part 8 serving as a counter electrode has a metal part serving as a safety guard disposed in front of the nohend / L part 8 . A convex portion 14a is formed protruding from a portion of the paint pipe 14 at a position as close to the charging electrode 24 as possible. The shape of the protrusion 14aid is not specified as long as it is a protrusion that tends to concentrate an electric field in order to exert the counter electrode effect.

Alternatively, instead of the convex portion 14a protruding from the paint pipe 14, it is possible to place an Itlle charging electrode 24 at the tip of the conductive hook portion 12 protruding from the L portion of the conductive handle portion 8.
The opposing electrode effect can also be exerted by forming the convex portion 12a at a position close to .

Next, in the above configuration, the operation of the present invention is explained as follows.
First, grasp the handle part 8 and press the trigger. When pulled, the needle valve 6 retreats, and the paint is applied to the high voltage cable 18, electrical passage section 11. A disk-shaped power receiving electrode 26V of the high-resistance body 8 is connected to the center alloy 25, which is sprayed from the nozzle/L port 20 and discharges across the fv paint film, promoting ionization and effectively charging the paint. At the same time, the electric field electrode 2 extending forward from the power receiving electrode 26
1. Discharge from the tip of 7 toward the object to be coated to form a stable electric field between the objects to be coated. ¥, the electric field electrode 27 is a counter electrode,
That is, an electric field is formed by discharging also between the nozzle part 8 of the gun, but in the case of the present invention, rather than simply using the conductive handle part 8 as a counter electrode, A part of the metal paint pipe 14 located in the part 8 and as close as possible to the electric field electrode 27, or a nozzle part 8
1: By forming the convex portion 14a or the convex portion i2a protrudingly at a position close to the electric field electrode 27 at the tip of the hook portion 12 of the section 1:, the electric field upward from the electric field electrode 27 is applied to the convex portion 14a or the convex portion 12a. The concentrated 1-1 counter electrode effect is enhanced and a stable electric field is formed.

In experiments carried out by the present inventor, the electrostatic effect is shown in the table below when 14 parts of the metal paint pipe are provided with convex parts and when there are no convex parts (the shape of the convex parts is , 0=2, l=2
(cod).

That is, as shown in the table, by providing a convex portion as a counter electrode, the turning value is increased, and
The return current value of the nozzle becomes large. The handle return current value will increase.

It can be seen as a discharge of a certain degree of strength.5For example, when the electrode is close to a grounded object, the discharge can be maintained for several seconds. Similarly, the present invention relates to a tip atomizing section.

A charged electrode that receives and discharges a high voltage supply, a charged electrode that receives discharge across the paint film from the nozzle opening, and a charged electrode that extends forward from the scissor powered receiving electrode. The floating electrode is configured as a floating electrode, and a convex part is formed on the conductive paint pipe or hook part of the gun nozzle part as a counter electrode to concentrate the electric field as close as possible to the electric field electrode. Accordingly, rI
x Charge the atomized paint by discharging from the charged electrode across the sprayed paint film to the floating electrode, promoting ionization and effectively charging the paint, and the floating electrode charges the paint mist. Regardless of the area or condition, a stable electric field can be formed between the convex part of the nod 11, which becomes the counter electrode, and the object to be coated, and the electrostatic effect can be further enhanced.In other words, a floating electrode is provided. As a result, the electric field electrode at the tip of the floating electrode takes charge of electric field formation, and compared to the case of one charged electrode,
As the electric field to the object to be coated becomes stronger (the current increases), the supply current increases, which intensifies the discharge at the charging electrode, and increases the paint charging current to the object to be coated.

Furthermore, in the case of a single charging electrode, it is necessary to place the electrode away from the most effective position (near the atomization area) in order to prevent the discharge effect from decreasing due to adhesion of paint. According to the present invention, by providing the floating electrode, the functions of the charging electrode and the floating electrode are separated, and the charging electrode promotes ionization by discharging to the floating electrode to effectively charge the paint, and the floating electrode effectively charges the paint. A stable electric field can be formed between the counter electrode and the object to be coated regardless of the atomization area or the atomization state, and the electrostatic effect can always be enhanced.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal side view, and FIG. 2 is an enlarged sectional view of the tip atomizing section. l・・・・・・Airless electrostatic gun 2・・・・・・
... Barrel part 8 ... Handle part 4.
......Tip atomizing section 5...Paint passage 11...Electric passage section 12...
...Hook part 12a...Protrusion part 1
4...Paint pipe X4a...
Five convex portions 20...Spray nozzle 24...
...Charged electrode 25...Floating electrode 26...Receiving electrode 27...
・・Electric field electrode

Claims (1)

[Scope of Claims] 1. A high-potential charging electrode is provided at the tip of a body part made of an insulating material and containing a paint passage and an electrical passage, and a high-potential charging electrode is provided at the rear of the gun barrel part, and the charging part is made of a conductive material and In an electrostatic coating device having an electrode facing the electrode, a floating electrode having a power receiving part disposed apart from the charging electrode and having an electric field electrode extending forward is provided to connect the charging electrode and the power receiving part. an airless electrostatic coating device, characterized in that a spray nozzle through which paint is sprayed is opened between the two electrodes, and a convex portion is provided at a position as close to the electric field electrode as possible on a part of the opposing electrode. . 2. The airless electrostatic coating device according to claim 1, wherein the convex portion is formed on a part of a conductive paint pipe disposed in front of the handle portion. & The airless electrostatic coating device according to claim 1, wherein the convex portion is formed at the tip of the conductive hook portion protruding from the handle portion.