JPS5831225B2 - Sadent Sou Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a metal cylinder 5 having a knife portion 7 at its tip and driven to rotate at high speed; an annular air chamber 9 disposed on the outer periphery of the annular air chamber 9; and an annular air chamber 9 arranged on the front wall of the annular air chamber 9 in an annular row coaxially with the cylindrical body 5; a plurality of air jet holes 10 that are opened parallel to the axis of the cylinder, a paint supply path that supplies a thin film of paint to the inner periphery of the knife portion 7, and the cylinder 5 and the object A to be painted. An electrostatic coating device characterized by comprising a high voltage generation source 33 that applies a high voltage between the annular air chamber 9 and a high pressure air generation source 2 that supplies high pressure air to the annular air chamber 9. The purpose of this is to promote atomization of paint mist, eliminate donut patterns and other coating unevenness, improve coating efficiency and enable quick painting work, and to use static electricity with a simple structure and easy operation. To provide a coating device, an embodiment of the present invention will be described below in detail with reference to the drawings. 01 is a pipe-shaped rotating shaft that is rotated at high speed, has a female threaded portion 13 at the rear end, and a male threaded portion at the tip of the relay pipe shaft 14. It is screwed and connected to the part 15.

A disk-shaped base body 3 is integrally provided at the tip of the pipe-shaped rotating shaft 1, and the hollow part 4 tip of the pipe-shaped rotating shaft 1 is closed by the front wall of the base body 3, so that the pipe-shaped rotating shaft 1 is A cylindrical body 5 is integrally provided around the outer end of the coaxial base body 3.

The cylindrical body 5 has an inner circumferential surface that gradually increases in diameter in a tapered manner from the front and back of the base 3, and the inner circumferential surface at the rear of the base 3 and the inner circumferential surface at the front of the base 3 of the cylindrical body 5 are defined by the plurality of inner circumferential surfaces provided on the base 3. tunnel section 6...
The tunnel portions 6 are formed at equal intervals in the circumferential direction at the outer peripheral end of the base body 3.

Further, a knife portion 7 is formed at the tip of the cylinder 5 by making the taper slope of the inner circumferential surface of the cylinder body 5 even steeper.

Further, an annular air chamber 9 is formed on the outer periphery of the cylinder 5 behind the knife portion 7, and a large number of air jet holes 10 are formed at equal intervals on the front wall of the annular air chamber 9. It is perforated as ultra-fine pores.

That is, in the front wall of the annular hollow chamber 9, an air jet hole 10 is bored with its center coincident with the outer circumferential edge of the knife portion 7 of the cylinder 5, parallel to the axis of the cylinder 5, and just behind the outer peripheral edge of the knife part 7 of the cylinder 5. This air jet hole 10 is bored parallel to the axis of the cylinder body 5, so that the jet stream jetted out from the air jet hole 10 flows almost uniformly around the outer periphery of the knife part. An appropriate number of communication holes 11 are provided radially outward from the hollow part 4 of the rotating shaft 1, and the annular air chamber 9 is connected to the hollow part of the pipe-shaped rotating shaft 1 through the communication holes 11. Reference numeral 017 connected to the supply pipe 1 is a paint supply pipe, and the paint is caused to fall from the tip 17a onto the inner peripheral surface of the rear part of the base 3 of the cylinder 5.
The rear part of 7 is connected in communication with a paint supply section 18 consisting of a paint pump, a paint tank, etc., and paint is continuously supplied.

This paint supply section 18 uses one that has been subjected to high voltage insulation treatment.

Reference numeral 19 denotes a fixed cylinder fixed on the front surface of the air motor 20 coaxially with the motor shaft 21. A bearing cylinder 22 is disposed at the tip of the fixed cylinder 19, and two bearing cylinders are disposed inside the bearing cylinder 22. bearing bearings 23, 23 and these bearing bearings 23
．． The rear end of the relay pipe shaft 14 is connected to the tip of the motor shaft 21 via a joint 25.The rear end of the relay pipe shaft 14 is closed. It has a hollow portion 26 , and a through hole 27 that opens to the outer peripheral surface of the relay pipe shaft 14 is communicated with the rear end of the hollow portion 26 .

An annular groove 28 is formed on the inner circumferential surface of the metal part 24 corresponding to the opening 27a of the through hole 27, and a connecting hole 29 is connected to the annular groove 28, and an air tube 3 is connected to the rear end of the connecting hole 29.
High-pressure air is fed into the annular groove 28 from the high-pressure air generation source 2 through the high-pressure air source 2 through the annular groove 28, and the high-pressure air is also fed into the hollow parts 26 and 4 of the relay pipe shaft 14 and the pipe-shaped rotating shaft 1 from the annular groove 28. , the jet stream of the annular cylinder is introduced into the annular air chamber 9 through the communication holes 11 of the base body 3, and is sent out from the air jet hole 10 provided through the front wall of the annular air chamber 9. It is.

Further, the terminal screw 32 provided on the bearing tube 22 is for connecting the other end of the lead wire 34 whose one end is connected to the high voltage generation source 33, and connects the object A to be painted, the fixed tube 19, and the relay pipe. A high voltage is applied between the shaft 14, the pipe-shaped rotating shaft 1, the cylindrical body 5, the base body 3, and the like.

In the figure, 37 is an insulating arm rod, and 38 is a support attachment portion of the insulating arm rod 37.

In the above embodiment, however, the paint is supplied from the paint supply section 18 to the supply pipe 17 via the paint tube 35, and is continuously introduced in small amounts into the rear part of the cylinder 5 from the opening at the tip 17a of the supply pipe 17. The paint is made to flow down on the peripheral surface. Meanwhile, the high-pressure air flow supplied from the high-pressure air generation source 2 through the air tube 36 rotates the air motor 20, which causes the pipe-shaped rotating shaft 1, the base body 3, and the cylindrical body to rotate. 5. The motor shaft 21, relay pipe shaft 14, etc. are rotated at high speed.

The paint that has flowed down onto the inner peripheral surface of the cylinder 5 is subjected to centrifugal force due to the high speed rotation of the cylinder 5, and spreads to the rear inner peripheral surface of the cylinder 5 while at the same time spreading along the taper of the inner peripheral surface of the cylinder 5. It moves toward the tip while becoming a thin film, and finally passes through the tunnel part 6 of the base body 3 and is supplied to the front inner peripheral surface of the cylinder 5, and further on the front inner peripheral surface of the cylinder 5. The paint in the form of a thin film is supplied to the knife portion 7 along the taper while spreading toward the inner circumference of the cylinder. The atomized paint is electrostatically atomized by the action of the high electric field caused by the high voltage applied to the paint, and furthermore, the action of this electric field causes the atomized paint to start flying toward the object to be painted, which is kept at ground potential. Ru.

On the other hand, the air jet holes 10 provided in the front wall of the annular hollow chamber 9 are
Since the hole is bored in parallel to the axis of the cylinder 5 at a position immediately behind the outer periphery of the knife part, the high-pressure air fed into the annular hollow chamber 9 is ejected from the air outlet 10 and becomes a jet stream. Since this jet stream collides with the outer peripheral edge of the knife part 7, the jet stream collides with the thin film of paint that is being shaken off by the action of centrifugal force from the knife part 7, causing the aforementioned static It performs the action of paint atomization along with the electric action and centrifugal force action, and also gives an initial velocity to the atomized paint particles.

Furthermore, at the same time, since the jet stream is ejected from the air ejection hole 10 provided in the annular hollow chamber in a rotating state, the jet air ejected from the air ejection hole 10 parallel to the axis of the cylindrical body 5 is , a rotary annular cylindrical shape in which the jet flows in the direction of the object A to be coated along a passage parallel to the axis of the cylinder 5 on the outer periphery of the knife part and has a rotational action coaxially rotating with the axis of the cylinder 5 in a spiral shape. It will flow out as a jet stream.

Therefore, this rotating annular cylinder-shaped jet airflow that flows in a spiral form forms a virtual airflow tube extending from the outer circumference of the cylinder 5 to the object A to be coated, and this virtual Since the target tube is formed by a rotating annular cylindrical jet stream that flows in a spiral, the radius of rotation of the spiral jet stream increases as it approaches the object to be coated due to the centrifugal force acting on the jet stream itself. The inner diameter of the virtual tube at the position of the object to be painted A becomes an inner diameter suitable for painting the object A to be painted.

Thus, as described above, the particles of the atomized paint atomized in the knife part 7 receive an initial velocity from the jet stream in the direction of entry into the object to be coated at the same time as this atomization, and the particles of the atomized paint atomized in the knife part 7 receive an initial velocity from the jet stream in the direction of entry into the object to be coated, and the particles of the atomized paint are This promotes the dispersion of the atomized paint within the virtual tube formed by the process, and the atomized paint that was initially atomized in an annular shape along the shape of the knife part 7 is immediately dispersed into the hollow interior of the virtual tube. The paint is evenly dispersed in the paint, forming a tail stream of atomized paint.

In this way, the atomized paint that is synergistically atomized by the centrifugal force, electrostatic force, and compressed air blowing force in the knife part 7 is acted upon by the jet air stream of the rotating ring tube. The atomization is promoted by the force, and at the same time, the atomized paint is confined within the virtual tube formed by this rotating annular cylindrical jet stream, so that the atomized paint is enveloped by the virtual tube and spreads out slightly. The atomized paint is uniformly dispersed inside this end stream, and the virtual tube prevents the atomized paint from scattering in unnecessary directions.
Furthermore, the flying direction of the atomized paint is made uniform in the direction in which the object to be coated enters, and the atomized paint is coated by the initial velocity applied by the rotating air jet flow and the Coulomb force acting on the fine particles of the atomized paint. It flies onto the object to be painted and is deposited on the surface of the object A to be painted in a uniform coating pattern.

As described above, the present invention includes an annular air chamber that rotates integrally with a cylinder and is arranged around the outer periphery of the cylinder, and a large number of air jet holes bored in the front wall of the annular air chamber. , and a high-pressure air generation source that supplies high-pressure air to the annular air chamber, there is no loss of high-pressure air in the middle of the high-pressure air supply path, and the flow rate of the jet stream ejected from the air outlet can be reduced. This increases the flow velocity of this jet stream, making it possible to obtain a jet stream with a large acting force, and furthermore, this jet stream is directed from a position immediately behind the outer periphery of the knife part to the outer periphery of the knife part. Therefore, the impact force caused by the jet stream is synergistically applied to the thin film-like paint on the knife part along with the electrostatic force due to the high voltage applied to the cylinder and the centrifugal force due to the high speed rotation of the cylinder. Therefore, even when the voltage applied to the paint through the cylindrical body is relatively low, it is not only possible to sufficiently atomize the paint into a fine mist, but it is also possible to atomize the paint only by the electrostatic force. Even when using water-based paints or other conductive paints, which are difficult to use, it has the effect of making the paint into a fine mist for electrostatic painting1. Since an initial velocity is applied, the fine particles can be sufficiently transported to the object to be coated even if the voltage applied between the object to be coated and the cylinder is relatively low.

In addition, in the present invention, the annular air chamber formed on the outer periphery of the cylinder is arranged in an annular manner coaxially with the cylinder, and opens forward as a very small hole immediately after the outer circumference of the knife part is kneaded. Since a large number of air ejection holes are provided parallel to the axis of the cylinder, at the outer periphery of the knife part, the rectified jet stream having only a relatively straight direction component is approximately uniform. - the liquid paint is effectively atomized by the action of this jet stream, and the turbulence of the jet stream does not adversely affect the atomization effect; The jet stream ejected from the air outlet is jetted toward the object to be coated along a path approximately parallel to the axis of the cylinder on the outer periphery of the knife part, and is jetted in a spiral shape with a rotational force that rotates coaxially with the cylinder. After contributing to the atomization or atomization of the liquid paint at the knife part as described above, the atomized paint is guided by the rotating annular and cylindrical jet stream that jets out in a spiral shape. This has the effect of forming a good virtual tube, and since the centrifugal action caused by the spiral jet flow acts on the jet air flow itself, the virtual tube becomes wider at the end. Therefore, the atomized paint surrounded by the above-mentioned virtual tube forms a tail flow from the knife part to the object to be painted. In addition to greatly reducing losses caused by paint scattering in unnecessary directions, the jet stream gives an initial velocity to the atomized paint, which creates a mist inside the virtual tube. The coating paint is evenly dispersed, and therefore a uniform coating pattern can be obtained without producing the doughnut-shaped coating pattern that is a characteristic and drawback of conventional rotary cup type electrostatic coating machines. ○Thus, in the device of the present invention, the tail stream of the atomized paint is jetted in the shape of a rotating ring tube. Since the jet stream is covered with a virtual tube formed by the jet stream, it is difficult to make the jet stream into a cylindrical shape compared to the case where the virtual tube is formed by an annular cylindrical jet stream flowing in a straight line. It has a strong holding force, so even if a cylinder is used while moving, the jet stream in the rotating annular cylinder will not collapse from its cylinder shape and the virtual tube will not collapse, and the paint mist will always be maintained. It has the effect that the tail flow is maintained and unnecessary paint is not scattered, and therefore a wide area object to be painted or many small objects to be painted can be coated at once by swinging or moving the cylinder etc. Even when painting on a surface, the virtual tube formed by the rotating ring-shaped jet stream wraps around the tail stream of the atomized paint, so the tail stream of the atomized paint is directed precisely toward the object to be painted. There is no scattering of the atomized paint on the opposite side, and it has the effect that so-called reciprocating painting work, in which painting is performed while moving the cylinder, can be easily performed.

Furthermore, since the above-mentioned virtual tube is formed by the rotating annular cylindrical jet airflow spirally jetting around the outer periphery of the knife part, even when the strength of the jet airflow ejected from each air ejection hole varies, the above-mentioned This has the effect of preventing the direction of the virtual tube itself from being deviated from the direction of the object to be painted, which would increase the scattering of the atomized paint.

As mentioned above, in the present invention, it is possible to obtain a circular painting pattern without causing uneven coating, and it is not doughnut-shaped, and it is possible to perform reciprocating painting work, so there is less loss. The coating operation can be carried out quickly and in a small amount, and the coated surface obtained can be of high quality, and also has the advantage that conductive paints such as water-based paints can be used.

[Brief explanation of drawings]

Fig. 1 is a front view of the head section according to an embodiment of the present invention, Fig. 2 is a sectional view taken along the line X-X of the same head section, Fig. 3 is a sectional view of the relay pipe shaft section of the same above, and Fig. 4 is the entire same as above. This is a reduced schematic diagram of the device, in which 1 is a pipe-shaped rotating shaft, 2 is a high-pressure air generation source, 3 is a base body, 4 is a hollow part, 5 is a cylinder body, 6 is a tunnel part, 7 is a knife part, and 9 is an annular air chamber, 10 is air outlet, 1
The first communicating hole, A, is the object to be painted.

Claims (1)

[Claims] 1. A metal cylindrical body having a knife portion at the tip and driven to rotate at high speed, an annular air chamber that rotates integrally with this cylindrical body and is arranged around the outer periphery of the cylindrical body, and this annular air chamber. A large number of air injection holes are arranged in a ring on the front wall of the cylinder coaxially with the cylinder, and are opened in the forward direction as ultra-fine holes at the rear of the outer periphery of the knife part, which are bored parallel to the axis of the cylinder. , a paint supply path that supplies a thin film of paint to the inner periphery of the knife part, a high voltage generator that applies a high voltage between the cylinder and the object to be coated, and a high pressure air supply that supplies high pressure air to the annular air chamber. Electrostatic coating device 0 characterized by being equipped with a high-pressure air generation source.