JPH0612836Y2 - Rotating atomizing electrostatic coating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rotary atomizing electrostatic coating device for coating the outer surface of a vehicle, for example.

[Conventional technology]

The rotary atomizing electrostatic coating device supplies paint to a bell-shaped atomizing head attached to the tip of the rotating shaft, atomizes the paint by centrifugal force due to the rotation of the atomizing head, and simultaneously coats the coating device and the object to be coated. The fine particles of the paint are sprayed and adhered to the object to be coated by the attractive force of the electric field applied between them and the shaping air from the outlet of the coating apparatus.

Conventionally, as shown in FIG. 3, in a rotary atomizing electrostatic coating apparatus of the type in which paint and cleaning thinner are supplied into a bell-shaped atomizing head 53 by a paint pipe 52 passing through the center of a rotary shaft 51, Front 54 of bell-shaped atomizing head 53 during replacement
In consideration of the cleanability of the central portion of the paint, the paint and the wash thinner are supplied from the discharge hole of the paint pipe 54 which coincides with the axis of the rotary shaft 51 to a small center provided at the rotation center of the bell-shaped atomizing head 53. The discharge was performed toward the holes 55. According to this method, since the liquid is discharged along the rotary shaft 51, and the small diameter of the small hole 55 of the bell-shaped atomizing head 53 is constant and thin, the flow velocity of the discharged paint is high, and as a result, the bell-shaped mist is formed. From the small hole 55 in the central part of the chemical head 53, the paint or the thinner for cleaning pops out like a thread along the axis of rotation without applying centrifugal force due to rotation, causing coating failure of the object to be coated, soiling the workplace, etc. There was a problem.

Therefore, in order to prevent the above problems, as shown in FIG.
A method has been considered in which an interference path 57 is provided in the middle of the hole 56 at the center of the bell-shaped atomizing head 53 to suppress the flow velocity of the paint or the thinner for cleaning in the hole 56.

[Problems to be solved by the device]

However, in the conventional method shown in FIG. 4, the flow velocity at the hole 56 of the paint or the thinner for cleaning is suppressed,
It was possible to prevent the paint coming out from the hole 56 from flowing along the surface of the bell-shaped atomizing head 53 and jumping out like a thread, but the interference path 57
The solid content of the paint is clogged inside, and the front surface 54 of the bell-shaped atomizing head 53 cannot be cleaned with a cleaning thinner, or
The structure is complicated, which leads to an increase in manufacturing cost, and further, it takes time to perform maintenance such as cleaning in the interference path 57.

Therefore, an object of the rotary atomizing electrostatic coating device of the present invention is to prevent the paint from splashing in a thread shape and to simplify the structure.

[Means for Solving the Problems]

Therefore, in the rotary atomizing electrostatic coating device of the present invention, the bell-shaped atomizing head is formed with a tapered hole having a slender surface that narrows backward in a slender shape at the center of the front surface of the bell-shaped atomizing head. A paint supply nozzle extending from the main body toward the front surface of the bell-shaped atomizing head has its tip curved and its center line passes through the center of the forehead portion at the rear end of the taper hole and is parallel to the mortar surface of the taper hole. It is characterized in that it is formed as follows.

[Action]

According to the rotary atomizing electrostatic coating device of the present invention, a tapered hole having a mortar surface is formed at the center of the front surface of the bell-shaped atomizing head, and the tip portion of the paint supply nozzle is curved so that its center line is Since the directions are aligned along the mortar surface of the bell-shaped atomizing head, some of the paint discharged from the paint supply nozzle passes through the small opening at the rear end of the taper hole of the atomizing head, The paint adheres to the surface of the mortar without bouncing or peeling, and the adhered paint smoothly moves to the outer surface of the mortar in the radial direction by the centrifugal force.

〔Example〕

Next, a rotary atomizing electrostatic coating device according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partial sectional view of a bell-shaped atomizing head portion of a rotary atomizing electrostatic coating apparatus according to this embodiment, and FIG. 2 is an enlarged sectional view of a central portion of the bell-shaped atomizing head portion of FIG. Is.

In the figure, reference numeral 1 is a coating apparatus main body of a rotary atomizing electrostatic coating apparatus, and a cylindrical rotary shaft 2 driven by an air motor (not shown) is rotatably supported at the center of the coating apparatus main body 1. .

A bell-shaped atomizing head 4 is fitted and fixed to the outer circumference of the rotary shaft 2 at a small diameter portion behind the bell-shaped atomizing head 4. A taper hole 6 for discharging paint is formed at the center of a front surface 5 formed inside the bell-shaped atomizing head 4 and opening in an obtuse angle close to a substantially flat surface. The tapered hole 6 has a mortar surface 7 that narrows backward, that is, to the left in the drawing in a mortar shape, and the diameter d of the forehead portion 8 at the rear end is arbitrarily set within the range of 0.5 to 3 mm. Further, the angle α of the mortar surface 7 with respect to the axis 9 of the rotary shaft 2 is set in the range of 30 ° to 60 °.

On the outer periphery of the front surface 5 of the bell-shaped atomizing head 4, a large number of discharge ports 10 through which most of the paint is discharged are opened at equal intervals.

A shaping air passage 11 having a ring-shaped cross section is formed through the inside of the tip of the coating apparatus main body 1, and shaping air is blown from the shaping air passage 11 to the bell-shaped atomizing head 4.

Inside the rotary shaft 2, a paint supply nozzle 12 is coaxially fixed to the main body 1 of the coating apparatus. The tip portion of the paint supply nozzle 12 is curved, and its discharge passage 13
The center line 14 of the bell-shaped atomizing head 4 extends through the center of the forehead portion 8 of the tapered hole 6 of the bell-shaped atomizing head 4 and along the mortar surface 7.
A discharge hole 15 opened at the tip of the paint supply nozzle 12
And the distance D from the center point of the forehead portion 8 of the taper hole 6 of the bell-shaped atomizing head 4 are set to 2 to prevent the influence of the flapping when the paint and the cleaning thinner are turned on and off. 10 mm
It is set in the range of.

According to the bell-shaped atomizing head of this embodiment having such a configuration, the paint or cleaning thinner discharged from the discharge hole 15 of the paint supply nozzle 12 has a part of the taper of the bell-shaped atomizing head 4. It reaches the mortar surface 7 through the center of the small portion 8 of the hole 6. Then, most of the paint or the thinner for cleaning is conveyed to the discharge port 10 by centrifugal force and is supplied to the front surface 5 of the bell-shaped atomizing head 4 through the discharge port 10.

Part of the paint or cleaning thinner that has reached the mortar surface 7 reaches the front surface 5 without interruption and evenly along the mortar surface 7 due to the centrifugal force of the rotating bell-shaped atomizing head 4. Along with this, it is carried to the outer peripheral portion of the bell-shaped atomizing head 4 and, together with most of the paint that has passed through the discharge hole 10, is sprayed from this outer peripheral portion and atomized.

[Effect of device]

As described above, according to the present invention, the bell-shaped atomizing head is formed with a tapered hole having a tapered mortar surface that widens in the discharge direction through the front surface of the atomizing head. Since the tip portion is curved so that its center line passes through the center of the small edge portion at the rear end of the taper hole and is along the mortar surface, the paint discharged from the paint nozzle or the thinner for cleaning, It does not bounce or peel off and adheres well to the surface of the bell-shaped atomizing head.
It has an excellent effect that the paint is atomized normally and that the surface of the mortar is satisfactorily cleaned.

In addition, the bell-shaped atomizing head has a taper hole having a mortar surface on the front surface, and only the inclination of the paint supply nozzle is changed. Thanks to the mortar surface, it has an excellent effect that clogging due to solid matter of the paint can be eliminated more than ever before.

[Brief description of drawings]

FIG. 1 is a sectional view of a bell-shaped atomizing head of a rotary atomizing electrostatic coating device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a central portion of the bell-shaped atomizing head of FIG. is there. FIG. 3 is a sectional view of a bell-shaped atomizing head of a conventional rotary atomizing electrostatic coating device, and FIG. 4 is a sectional view of a bell-shaped atomizing head of another conventional rotary atomizing electrostatic coating device. 2 ... Rotating shaft 4 ... Bell-shaped atomizing head 5 ... Front surface 6 ... Taper hole 7 ... Sliding surface 8 ... Small portion 12 ... Paint supply nozzle 14 ... Center line

Claims (1)

[Scope of utility model registration request] 1. A bell-shaped atomizing head attached to a rotary shaft that rotates about its axis is supplied with paint to the front side of the bell-shaped atomizing head to diverge this paint by centrifugal force and atomize it. In a rotary atomization electrostatic coating device that coats the surface of an object to be coated by generating an electrostatic field between the atomization head and the object to be coated, the bell-shaped atomizing head is directed backward toward the center of the front surface. A taper hole having a mortar-like surface that narrows in a mortar shape is formed so as to penetrate therethrough, and a paint supply nozzle that extends from the main body of the coating device toward the front surface of the bell-shaped atomizing head has a tip portion that is curved and the center line is tapered. The rotary atomizing electrostatic coating device is characterized in that it is formed so as to pass through the center of the small portion at the rear end of the hole and to be parallel to the mortar surface of the tapered hole.