JPH0137717Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention promotes atomization by injecting paint at a predetermined high liquid pressure and by spraying auxiliary air or pressurized air into this paint jet flow. The present invention relates to a coating device of a type that allows

[Prior art]

2. Description of the Related Art Conventionally, so-called airless spray nozzles have been known that spray paint pressurized to a predetermined pressure toward an object to be coated from a lip-like paint injection port formed in a paint nozzle. However, with this airless spray nozzle, it is necessary to pressurize the paint to a high liquid pressure of approximately 100 to 300 kg/ ^cm3 , and the paint pump, hose, etc. must be able to withstand high liquid pressure. In addition, there is the problem that the paint flows through the paint nozzle at high speed, causing severe wear on the nozzle, and the so-called tail phenomenon occurs at both ends of the paint spray pattern, impairing the quality of the coating. There is a point.

In order to solve this problem, a 0.5~
By blowing pressurized air of about 5Kg/ ^cm3 ,
Various products have been proposed that can improve the atomization efficiency even when the paint pressure is relatively low, such as about 30 to 100 kg/cm ³ , and can prevent the occurrence of the tail phenomenon.

As such conventional technology, for example,
-22085 Publication, Japanese Patent Publication No. 54-8496, Japanese Patent Publication No. Sho
As shown in Publication No. 56-70864, the air nozzle is provided with an air injection port behind or to the side of the paint injection port of the paint nozzle, and the air injection port of the air nozzle is provided on the side or side of the paint injection flow. A device in which auxiliary air is supplied from the rear to promote atomization, or an air outlet is provided in front of the paint injection port so as to surround the paint injection port, as shown in Japanese Utility Model Application Publication No. 57-90762. There is a known structure in which auxiliary air is blown around the paint jet to promote atomization and prevent the tail phenomenon.

However, in each of the above-mentioned conventional technologies, the aim is to promote atomization by spraying auxiliary air or pressurized air against the paint jet flow, so the interaction between the paint jet flow and the auxiliary air is difficult. At the time of collision, turbulence occurs in the paint jet stream, and some of the paint particles scattered due to this turbulence adhere to the paint jet port of the paint nozzle or near the air jet port of the air nozzle.
As a result, they gradually grow in the vicinity of the paint injection port and air injection port, causing problems such as impeding paint injection and clogging the paint injection port and air injection port.

On the other hand, paint particles also adhere to the peripheral walls of paint nozzles and air nozzles, and when these gradually grow, the paint drips onto the object to be coated, resulting in a so-called spitting phenomenon.

Therefore, in the case of conventional technology, 30
The reality is that the paint nozzle and air nozzle have to be disassembled every 60 minutes, cleaned with a cleaning solution such as thinner, and reassembled for painting, which has the disadvantage of being extremely troublesome.

[Problem that the invention attempts to solve]

The present invention was devised in view of the problems of the prior art described above, and by using an air nozzle to spray out cleaning liquid and air at predetermined intervals, the present invention It is an object of the present invention to provide a coating device that can automatically clean the vicinity of an outlet or the surrounding walls of a paint nozzle or an air nozzle.

[Means for solving problems]

In order to solve the above problems, the present invention includes a nozzle holder provided on a gun body, a paint nozzle provided in the nozzle holder and having a paint injection port formed in a spherical part at the tip, and a paint nozzle provided on the inner surface of the nozzle holder. A spherical concave surface surrounding the holder and the paint nozzle is formed, and an air jet opening is located in front of the spherical tip end of the paint nozzle and blows an auxiliary air flow toward the paint jet jetted from the paint jet nozzle. an air nozzle formed along the entire circumference between the spherical concave surface of the air nozzle and the spherical tip of the nozzle holder and the paint nozzle, and supplying auxiliary air toward the air outlet; In the painting apparatus, the air passage is connected to an air source and a cleaning liquid source via a fluid flow path, and in the middle of the fluid flow path, there is a connection between auxiliary air and cleaning liquid to be supplied to the air outlet of the air nozzle. A switching valve for fluid switching is provided, and by supplying cleaning liquid to the air passage through the switching valve, paint adhering to the spherical tip of the paint nozzle, the paint injection port, the spherical concave surface of the air nozzle, etc. can be cleaned. It is characterized by having a configuration in which:

[Effect]

With this configuration, cleaning liquid can be supplied from the air passage to clean paint adhering to the spherical tip of the paint nozzle, the paint injection port, the concave surface of the air nozzle, etc., and prevent clogging of the paint injection port. , prevent the occurrence of spitting phenomenon, etc.

〔Example〕

Hereinafter, the present invention will be described in detail, taking as an example the case where it is applied to an autogun type electrostatic sprayer, together with embodiments shown in the drawings.

In FIG. 1, reference numeral 1 denotes an autogun type electrostatic sprayer, and the sprayer 1 includes a gun body 2 having a paint passage and an air passage, which will be described later, inside, and a gun body 2 provided at the tip side of the gun body 2. It is roughly composed of an electrostatic spray nozzle 3, which will be explained in detail in FIG. A known valve opening/closing mechanism 4 consisting of an air-driven actuator is provided in the gun body 2, and an arm 5 to be attached to a reciprocator or the like is provided in the gun body 2, and a mounting bracket 6 is attached to the arm 5. At the same time, a high voltage cable 38, which will be described later, is also attached.

Next, FIG. 2 is an enlarged longitudinal sectional view of the main part of FIG. 1 showing the electrostatic spray nozzle 4, and FIG. 3 is a left side view of FIG.
A paint passage 11 connected to the air passage 11 and an air passage 12 connected to the air hose 43 are formed, and an annular groove 13 connected to the air passage 12 is formed on the end surface 2A of the gun body 2.
is formed. On the other hand, a valve rod 14 is provided to penetrate inside the paint passage 11, one end of the valve rod 14 is attached to the aforementioned valve opening/closing mechanism 4, and a valve body 15 is provided at the other end, and the valve opening/closing mechanism 4, the valve body 15 is moved to and from the valve seat 16 to open and close the paint passage 11.

Reference numeral 17 denotes a nozzle holder located on the end surface 2A of the gun body 2. The holder 17 is formed in a hemispherical shape and has a plurality of air passages 18 in the axial direction.
are formed, and each air passage 18 communicates with the annular groove 13, respectively. A spacer 19 is fitted into the nozzle holder 17, and the spacer 19 is made of an elastic material such as Teflon. It is communicated with 11.

Reference numeral 21 designates a paint nozzle whose tip spherical portion 21A is fitted into the nozzle holder 17 so as to protrude from the nozzle holder 17, and the paint nozzle 21 is connected to the spacer 19 by the spacer 19. is held between. The paint nozzle 21 is provided with a lip-shaped paint injection port 22 by cutting the spherical portion 21A into a V-shape, and the paint supplied from the paint passages 11 and 20 is ejected from the paint nozzle 21. The paint is ejected from the mouth 22 as a fan-shaped paint jet.

Further, 23 indicates an air nozzle, and a spherical concave surface 24 is formed on one side of the air nozzle 23, and the paint nozzle 21 and the nozzle holder 17 are housed in the concave surface 24 so as to be surrounded. By fastening the nut 25 to the gun body 2, the air nozzle 23 is held between the end surface 2A of the gun body 2 and the nut 25, and the nozzle holder 17 has a spherical concave abutting surface 17A. 24 and are held between the spherical concave surface 24 and the end surface 2A, and the nozzle holder 17 and air nozzle 23 as a whole are fixed to the gun body 2.

The air nozzle 23 has a lip-shaped air outlet 2 located in front of the spherical tip 21A of the paint nozzle 21.
6 is formed. This air outlet 26 is connected to the central convex portion 23A of the air nozzle 23 (see FIG.
By carving the V-shaped groove 27, the V-shaped groove 2
7 and the spherical concave surface 24, and the angle θ of the V-shaped groove 27 is set to the same value as the V-shaped angle of the paint injection port 22.

On the other hand, an annular groove 28 communicating with the air passage 18 is formed between the outer peripheral surface of the nozzle holder 17 and the spherical concave surface 24 of the air nozzle 23, and air is jetted from the annular groove 28 on the outer peripheral surface of the nozzle holder 17. Exit 2
A small-diameter surface 17B having a smaller diameter than the abutting surface 17A is formed toward 6, and an air passage 2 is formed between the small-diameter surface 17B and the inner peripheral surface of the spherical concave surface 24 over the entire circumference.
9 is formed. Then, pressurized air is supplied from the air passage 29 toward the air outlet 26 through the air passage 12, the annular groove 13, the air passage 18, and the annular groove 28 in order, so that the paint is injected from the paint injection opening 22. The jet stream is surrounded by the air stream, which promotes atomization and prevents the occurrence of a tail phenomenon.

Further, 30 is a high resistance for safety provided in the gun body 2, one end of the high resistance 30 is connected to a high voltage cable 38 which will be described later, and the other end is connected to a conductor 3.
1 is connected, and the conductor 31 extends to the end surface 2A of the gun body 2. 32 is a conductor embedded in the air nozzle 23, one end of the conductor 32 is connected to the conductor 31 via the connection spring 33, and the other end is connected from the horn portion 23B of the air nozzle 23 to the front position of the air jet port 26. The needle-like electrode 34 protrudes from the top.

Next, the connection between the electrostatic sprayer 1 configured as described above and external equipment will be described with reference to FIG.

35 is a paint hose; one end of the paint hose 35 is connected to the gun body 2 and communicates with the paint passage 11, and the other end is connected to the paint tank 3 via a pump 36.
7, and the paint is supplied to the paint nozzle 21 which opens the valve body 15 by the valve opening/closing mechanism 4.

38 is a high voltage cable, and the high voltage cable 3
One end of 8 is attached to the arm 5 of the gun body 2 and connected to the high resistance 30, and the other end is connected to the high resistance 30, for example, from -60 to
High voltage generator 39 that generates a high voltage of 120 [KV]
is connected to. The high voltage from the high voltage generator 39 is transmitted to the high voltage cable 38, the high resistance 30,
By applying a high voltage to the needle-shaped electrode 34 via the conductor 31, spring 33, and conductor 32, the air around the needle-shaped electrode 34 is ionized to form a corona sphere, and the air is sprayed from the air outlet 26. The charged paint particles are charged to a potential of the same polarity as the applied voltage, and the charged paint particles are transferred between the tip of the needle electrode 34 or the horn portion 23B, if it is a metal body, and the object to be coated. It is caused to fly along the formed lines of electric force and coated on the object to be coated.

Reference numeral 40 denotes an air hose for valve driving air. One end of the air hose 40 is attached to the gun body 2 and connected to the valve opening/closing mechanism 4, and the other end is connected to an air source 42 via an opening/closing valve 41. Here, the opening/closing valve 41 is an air pilot type switching valve consisting of, for example, a two-port, two-position switching valve, and is controlled to open and close by an air pilot signal from a control device.

Further, reference numeral 43 denotes an air hose which is a main part of this embodiment. One end of the air hose 43 is attached to the gun body 2 and connected to the air passage 12, and the other end is connected to the outlet 44A of the switching valve 44. There is.
45 is an air hose, one end of which is connected to the air inlet 44B of the switching valve 44, and the other end connected to the air source 42 mentioned above. 4
Reference numeral 6 denotes a cleaning liquid hose, one end of which is connected to a cleaning liquid inlet 44C of the switching valve 44, and the other end connected to a cleaning liquid source 47 such as thinner. Here, the switching valve 44 is, for example, a 2-port 2-port
Air pilot type switching valve 4 consisting of a position switching valve
A combination of two 4D and 44E is used, one being an air supply side switching valve 44D and the other being a cleaning liquid supply side switching valve 44E. In this embodiment, the air hoses 43 and 45 and the cleaning liquid hose 46 constitute a fluid flow path.

This embodiment is configured as described above, but when the air supply side switching valve 44D of the switching valves 44 is opened, the pressurized air from the air source 42 is, for example, 2 kg/cm ³
The air is supplied to the gun body 2 through the air hose 45, the switching valve 44, and the air hose 43 at a pressure of
The air is supplied to the air outlet 26, and is ejected from the air outlet 26 as a fan-shaped air flow having an angle θ.

On the other hand, when the on-off valve 41 is opened in this state, pressurized air from the air source 42 is supplied to the valve on-off mechanism 4 via the air hose 40 and the on-off valve 41, and the valve stem 1
4, the valve body 15 is removed from the valve seat 16. As a result, the paint from the paint source 37 is e.g.
The paint is supplied to the gun body 2 through the paint hose 35 and the pump 36 at a pressure of 50 kg/cm ³ , and is further supplied to the paint nozzle 21 through the paint passages 11 and 20.
The paint jet is injected from the paint jet port 22 to the air jet port 26 as a paint jet stream having an angle θ.

At this time, the paint jet stream injected at high pressure from the paint nozzle 22 comes into contact with air as it advances through the low-pressure air stream jetted from the air nozzle 26 in front of the paint nozzle 22. As a result, atomization is promoted, and the occurrence of the tail phenomenon can be reliably prevented.

Furthermore, a needle electrode 34 is provided in front of the air outlet 26, and the needle electrode 34 includes a high voltage cable 38, a high resistance 30, a conductor 31, a spring 33,
A high voltage of -60 [KV], for example, is applied from a high voltage generator 39 via the conductor 32 . Therefore,
The air around the needle-like electrode 34 is negatively ionized to form an ionized sphere, and paint particles passing through this area are negatively charged and fly along the lines of electric force to the object to be coated.

However, when the paint jet jetted from the paint jet nozzle 22 breaks through the airflow jetted from the air jet nozzle 26, most of the paint particles pass through the air jet nozzle 26 and are directed toward the object to be coated. Although the paint particles are applied in flight, some of the paint particles are engulfed by the air flow flowing through the air passage 29. Therefore, a part of the paint from the paint injection port 22 is transferred to the paint injection port 22,
It adheres to the periphery of the spherical portion 21A and also to the wall surface of the spherical concave surface 24 of the air nozzle 23.

Therefore, in this embodiment, after a predetermined time period for spraying the paint has elapsed, the spraying of the paint is stopped, and the paint nozzle 2
1. It is configured to clean the air nozzle 23, etc.

That is, FIG. 4 is an explanatory diagram explaining the cleaning operation.
After the aforementioned predetermined time has elapsed, the supply of pressurized air to the valve opening/closing mechanism 4 is stopped, the valve body 15 is closed, and the paint passages 11 and 20 are cut off (FIG. 4a).
Next, the air supply side switching valve 44D of the switching valve 44 is closed, and the supply of air from the air hose 43 to the air passage 12 is stopped (FIG. 4b).

In this state, the other cleaning liquid supply side switching valve 44E of the switching valve 44 is opened, and the cleaning liquid from the cleaning liquid source 47 is supplied to the gun body 2 via the cleaning liquid hose 46, the switching valve 44, and the air hose 43, and further air is Passage 12, annular groove 13, air passage 18, annular groove 2
8 to the air passage 29, and the air outlet 2
6 is ejected as waste liquid. During this time, paint adhering to the spherical portion 21A of the paint nozzle 21, the paint injection port 22, the spherical concave surface 24, etc. is cleaned (FIG. 4c).

Next, the cleaning liquid supply side switching valve 44E of the switching valve 44
is closed, the air supply side switching valve 44D is opened again, and the pressurized air from the air source 42 is transferred to the air hose 4.
5. Through the switching valve 44 and the air hose 45, the air is sent to the air outlet 26 via the same route as the cleaning liquid described above.
erupts from. At this time, air passages 12, 18, 2
Purge the cleaning liquid inside 9, etc., and clean these insides (Fig. 4 d).

Further, the above-described steps are repeated, and the cleaning liquid and pressurized air are sequentially supplied (Fig. 4e, f). On this occasion,
The above steps are repeated multiple times as necessary to completely clean the paint nozzle 21 and air nozzle 23.

After the cleaning is completed, pressurized air is supplied again (FIG. 4g) and paint is supplied (FIG. 4h) in the same manner as described above, and the painting operation can be resumed.

This embodiment is as described above, but in this embodiment, the case where the air nozzle 23 is provided in front of the paint nozzle 21 similar to that shown in Japanese Utility Model Application Publication No. 57-90762 was taken as an example. −22085 Publication, Special Publication
Similar to those shown in Publication No. 54-8496, Japanese Patent Application Laid-Open No. 56-70864, etc., it may be applied to those in which the air outlet of the air nozzle is provided behind or to the side of the paint outlet of the paint nozzle. be.

Further, in the embodiment, an auto-gun type electrostatic sprayer 1 is taken as an example of the applied sprayer, but a hand-gun type electrostatic sprayer may also be used.
4 may be used as a non-electrostatic sprayer.

Furthermore, in the embodiment, the switching valve 44 is connected to the gun body 2.
Although the switching valve 44 has been described as being located outside and provided at the other end of the air hose 43, the switching valve 44 is located outside the gun body 2.
The structure may be such that the gun body 2 is housed inside the gun body 2 or fixed to the outer wall of the gun body 2.

[Effect of idea]

The coating device according to the present invention is as described in detail above, and is configured to spray auxiliary air from the air nozzle of the air nozzle to the paint jet stream jetted from the paint nozzle of the paint nozzle to atomize the paint jet stream. In spray nozzles that perform acceleration, paint particles tend to adhere to the paint nozzle or air nozzle due to turbulence in the paint jet flow, but in the case of the present invention, cleaning fluid is Because of this structure, paint adhering to the paint nozzle and air nozzle can be easily cleaned, and even when quick-drying paint is used, it is ensured that the paint nozzle will not become clogged or the spitting phenomenon will occur. can be prevented.

[Brief explanation of the drawing]

Figure 1 is an overall configuration diagram of the coating device according to the present invention.
FIG. 2 is an enlarged sectional view of the main part in FIG. 1 showing the electrostatic spray nozzle, FIG. 3 is a left side view of FIG. 2, and FIG. 4 is an operation explanatory diagram showing the cleaning operation. 1...Auto gun type electrostatic sprayer, 2...Gun body, 3...Electrostatic spray nozzle, 4...Valve opening/closing mechanism, 11, 20...Paint passage, 12, 18, 29
...Air passage, 21...Paint nozzle, 22...Paint injection port, 23...Air nozzle, 26...Air injection port, 34...Acicular electrode, 35...Paint hose,
37...Paint source, 38...High voltage cable, 39
...High voltage generator, 40,43,45...Air hose, 41...Opening/closing valve, 42...Air source, 44...
...Switching valve, 46...Cleaning liquid hose, 47...Cleaning liquid source.

Claims (1)

[Scope of utility model registration request] a nozzle holder provided on the gun body; a paint nozzle provided in the nozzle holder and having a paint injection port formed in a spherical portion at the tip; a spherical concave surface surrounding the nozzle holder and the paint nozzle formed on the inner surface side; an air nozzle having an air jet opening positioned in front of a spherical tip end of the paint nozzle for blowing an auxiliary air flow toward a paint jet jetted from the paint jetting port; a spherical concave surface of the air nozzle; In the coating device, the air passage is formed along the entire circumference between the nozzle holder and the spherical tip of the paint nozzle, and supplies auxiliary air toward the air outlet, the air passage forming a fluid flow path. A switching valve is provided in the middle of the fluid flow path to switch the fluid between the auxiliary air and the cleaning fluid to be supplied to the air outlet of the air nozzle. Therefore, by supplying a cleaning liquid to the air flow path, the coating apparatus is configured to clean the paint adhering to the spherical tip of the paint nozzle, the paint injection port, the spherical concave surface of the air nozzle, etc.