JPH0422451A - Rotary atomizing type coating apparatus - Google Patents

Abstract

PURPOSE:To make paint particles fine by providing the injection part of pattern air along the entire outer peripheral region of an atomizing head and providing a guide passage in the injection part so as to incline the same in the direction reverse to the rotary direction of the atomizing head. CONSTITUTION:In a rotary atomizing type coating apparatus, the rotary shaft 3 rotating through a bearing 2 is supported in an inner cylinder l and the base part of a cup-shape atomizing head 4 expanding forwardly is fitted to the leading end of the rotary shaft 3. The leading end of the paint supply nozzle 5 piercing through the rotary shaft 3 is allowed to face to the atomizing head 4. Further, an outer cylinder 6 is provided outside the inner cylinder l and the supply passage 7 of pattern air is formed between the outer cylinder 6 and the inner cylinder l. A plurality of guide passages 10... are partitioned in the injection part 8 of the pattern air by guide plates 9... and inclined by theta deg.in the direction reverse to the rotary direction of the atomizing head 4. By this method, the smoothness of a film can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rotary atomization type coating device equipped with a pattern air jetting section for controlling a coating pattern.

(Prior Art) In addition to air atomization type and airless gun type painting equipment, rotary atomization type painting equipment with high coating efficiency is used as painting equipment for painting automobile bodies and the like.

This rotary atomizing coating device has an atomizing head with a diameter of about 5 cm and a normal rotation speed of 10. By supplying paint into this atomizing head while rotating at OOOrpm (circumferential speed 40/s) or higher, paint particles are scattered in the form of mist from around the atomizing head. JP-A-63-5 is a precedent example in which the scattering direction of mist particles is controlled using pattern air called shaping air to obtain a desired coating pattern.
The one disclosed in No. 9364 is known. In particular, in this prior example, as shown in FIG. 7, a pair of pattern air outlets 101.
1, and the direction of the air ejected from the pattern air outlets 101, 101 is set in the opposite direction to the rotating direction of the atomizing head with the radial direction of the atomizing head 100 as a reference, thereby creating a flat coating pattern that is uniform on the left and right sides. I'm trying to get it.

(Problems to be Solved by the Invention) In the conventional rotary atomization coating apparatus described above, it is necessary to make the coating particles finer in order to increase the smoothness of the coating film. In order to make the paint particles finer, the viscosity of the paint can be lowered or the rotational speed of the atomizing head can be increased.

However, in the former case, the paint adhering to the object to be painted tends to drip, so the paint film must be made thin, and for this reason it cannot be applied to the painting of automobile bodies, which requires a high rust prevention effect.

In addition, in the case of the latter, when the rotational speed of the atomizing head is increased and reaches a predetermined circumferential speed range (approximately 80 m/s or more), the resin and pigment in the paint begin to separate due to the difference in specific gravity. ,
Uniform coating will not be possible, and if the rotation speed of the atomizing head is increased too much, the durability of the device itself will be adversely affected.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a pattern air jetting part along the entire outer periphery of the atomizing head of a rotary atomizing coating device, and a pattern air jetting part is provided in the jetting part. A guide passage was provided to regulate the jetting direction, and the direction of the guide passage was tilted in a direction opposite to the rotational direction of the atomization head with respect to the rotational axis direction of the atomization head.

(Function) When the pattern air is ejected in the opposite direction to the rotational direction of the atomizing head, the pattern air strongly collides with the paint scattered from the atomizing head, promoting finer coating particles.

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

FIG. 1 is a sectional view of a rotary atomizing coating device according to the present invention, FIG. 2 is a partially cutaway side view of the rotary atomizing coating device, and FIG. 3 is a view taken in the direction of arrow A in FIG. be.

The rotary atomizing coating device has a rotating shaft 3 which is rotated by a drive device supported in an inner cylinder 1 through a bearing 2, and a cup-shaped atomizing head 4 that extends forward at the tip of the rotating shaft 3.
0 base is attached, and the tip of a paint supply nozzle 5 passing through the rotating shaft 3 is exposed inside the atomizing head 4.

Further, an outer cylinder 6 is provided outside the inner cylinder 1, and a pattern air supply passage 7 is formed between the outer cylinder 6 and the inner cylinder 1. Here, the diameter of the outer cylinder 6 gradually decreases toward the tip, and a pattern air jetting part 8 is formed between the outer cylinder 6 and the inner cylinder 1 at the tip. A plurality of guide passages 10 are partitioned into a plurality of guide passages 10 by guide plates 9 in the pattern air jetting part 8, and the direction of each guide passage 10 is set in the direction of the rotation axis I of the atomizing head 4. The atomizing head 4 is tilted by 00 in the direction opposite to the rotating direction of the atomizing head 4 based on the reference. This angle of inclination is suitably 100 to 60 degrees.

FIG. 4 is a sectional view of another embodiment, and FIG. 5 is a partially cutaway side view of another embodiment. In this embodiment, the guide passage 10 is not formed by the guide plate 9, A block 1 is provided in the block 11, and in this block 11 there is a θ0 in the direction opposite to the rotational direction of the atomization head 4 with reference to the direction of the rotation axis of the atomization head 4.
An inclined guide passage 10 is bored.

In any of the embodiments, when the atomizing head 4 rotates at high speed, the paint P supplied into the atomizing head 4 moves along the inner surface of the atomizing head 4 toward the outer periphery, and moves outside the atomizing head 4. Released from the periphery. The ejected paint P tries to become spherical due to surface tension, but due to resistance due to collision with air, the paint P is cut and becomes fine particles P°.

In particular, since the pattern air is ejected in a direction opposite to the direction of rotation of the atomizing head 4, the resistance between the paint and the air increases, further improving the fineness of the paint particles.

The above-mentioned effect does not change at all in electrostatic coating.

(Effects) As explained above, according to the present invention, a pattern air jetting part is provided along the entire outer periphery of the atomizing head of the rotary atomizing coating device, and the jetting direction of the pattern air is regulated within this jetting part. A guide passage was provided to prevent the pattern air from strongly colliding with the paint scattered from the atomizing head because the direction of this guide passage was tilted in the direction opposite to the rotational direction of the atomizing head with respect to the rotational axis direction of the atomizing head. However, the relative resistance between the paint and air increases, the finer particles of the paint are promoted, and the smoothness of the paint film can be improved.

Furthermore, sufficient atomization can be achieved even if the rotational speed of the atomizing head is kept low, and the durability of the device is also improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a rotary atomizing coating device according to the present invention, FIG. 2 is a partially cutaway side view of the rotary atomizing coating device, and FIG. 3 is a view taken in the direction of arrow A in FIG. 1. FIG. 4 is a sectional view of another embodiment,
FIG. 5 is a partially cutaway side view of another embodiment, FIG. 6 is a diagram explaining the operation, and FIG. 7 is a diagram showing a conventional example. In the drawing, 1 is an inner cylinder, 3 is a rotating shaft, 4 is an atomizing head, 5 is a paint supply nozzle, 6 is an outer cylinder, 8 is a pattern air jetting part, 9
1 is a guide plate, 10 is a guide passage, and 11 is a block.

Claims (1)

[Claims] In a rotary atomizing coating device in which a paint supply nozzle faces a cup-shaped atomizing head that rotates at high speed, a pattern air jetting part is provided along the entire outer periphery of the atomizing head, and a pattern air jetting part is provided within this jetting part. A rotary atomizing coating device characterized in that a guide passage is provided for regulating the direction of ejection, and the direction of the guide passage is tilted in a direction opposite to the rotational direction of the atomization head with reference to the rotational axis direction of the atomization head.