JP2004136177A - Air mix gun for mixing two liquids - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air mix gun for mixing two liquids, which can be used continuously for a long time without causing uneven hardening of coating and the workability of which is excellent for improving a conventional air mix gun. <P>SOLUTION: This air mix gun has a base resin spraying port opened like lips, a base resin supplying means for supplying a base resin to the base resin spraying port, a curing agent-air-mixed fluid jetting port and a curing agent-air-mixed fluid supplying means for supplying a curing agent-air-mixed fluid to the curing agent-air-mixed fluid jetting port. The curing agent-air-mixed fluid jetting port is arranged on both sides of the base resin spraying port on an extended line of the major axis of the base resin spraying port. The base resin is mixed with the curing agent by jetting the curing agent-air-mixed fluid so that the jetted curing agent-air-mixed fluid intersects the sprayed base resin on one flat plane. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a two-part mixed air mix gun.
[0002]
[Prior art]
Conventionally used two-component (multi-component) mixing spray guns include an internal mixing type and an external mixing type. The internal mixing type spray gun mixes and sprays two liquids inside the gun. On the other hand, there are an air spray method and an airless spray method as an external mixing type spray gun, and a method of mixing a curing agent into atomized air and a double head gun method as an air spray method. In the airless spray method, a double-head gun method is generally used.
[0003]
The spray gun of the internal mixing system cannot be used unless the internal cleaning is ensured, and therefore requires a cleaning function. In addition, the mixing is unstable in the spray gun of the external mixing system, and the jetting amount is small in the air spray gun system. It is difficult to stabilize the spray pattern and to adjust the mixture so as to obtain a uniform mixture by the method of mixing the curing agent into the atomized air and the double-head gun method. In addition, the airless double-headed gun method has a problem that the ejection amount is too large, the mixing ratio is difficult to adjust, and the coating film hardens and the quality tends to vary.
[0004]
In order to solve these problems, an external mixing type spray gun suitable for use in an intermediate region between an air spray and an airless spray has been proposed as a two-part mixing air mix gun capable of achieving a good mixing and atomization state ( For example, see Patent Document 1). That is, a spray nozzle that opens in a lip shape and injects and atomizes the main agent at high pressure, and a first air that injects a curing agent mixture stream toward the spray stream on both sides corresponding to the sprayed flat spray plane. A hole and a second air hole that collides with and expands the flow of the hardener mixed gas jetted from the first air jet before colliding with the jet flow of the main agent are provided.
[0005]
As described above, since the jet flow of the atomizing air containing the curing agent is expanded by the jet flow from the second air hole before colliding with the jet flow of the main agent, it becomes a flat flow and becomes a flat flow. It is said that uniform mixing can be achieved due to collisional mixing with the jet.
[0006]
[Patent Document 1]
JP-A-7-876
[Problems to be solved by the invention]
However, in such a mixing method, since the hardener mixed airflow injected from the first air hole collides with the airflow injected from the second air hole, scattering of mist to the periphery increases, The surface of the injection nozzle is contaminated with the main agent and the curing agent. As a result, stable injection cannot be obtained, and uneven curing of the coating may occur. For this reason, frequent cleaning of the injection nozzle is required, and as a result, there has been a problem that the continuous use time is shortened and the workability is reduced.
[0008]
The present invention relates to an improvement of a two-part mixed aermic gun made in order to solve such a problem, and an object thereof is that there is no unevenness in curing of a coating, continuous use for a long time is possible, and workability is improved. It is to provide a good two-part mixing air mix gun.
[0009]
[Means for Solving the Problems]
The present inventors, when externally mixing the main agent and the hardening agent, if the hardening agent mixed gas stream is mixed with the main agent without expanding, the mist to the periphery does not increase, and the surface of the injection nozzle is not mixed with the main agent. I came to realize that there was no problem such as staining with the curing agent.
[0010]
That is, the two-part mixed air mix gun of the present invention comprises a lip-shaped opening of the main agent spray opening, a main agent supply means for supplying the main agent to the main agent spray opening, a hardening agent air mixed fluid ejection port, and the hardening agent air. A hardening agent air mixing fluid supply means for supplying a hardening agent air mixing fluid to the mixing fluid jetting port, wherein the hardening agent air mixing fluid jetting port has a lip-shaped opening of a main agent spray opening. The main agent and the curing agent are mixed by ejecting the curing agent air mixed fluid so as to be located on both sides on the extension line of the major axis of the long axis and intersect on the same plane as the plane of the flat spray pattern of the main agent. It is characterized by. In other words, the position of the hardener air mixture fluid outlet is rotated by 90 ° with respect to the main agent spray port from the position of the prior art hardener mixture gas stream outlet, and both sides on the extension line of the major axis of the main agent spray port opened in a lip shape There is a special feature in that
[0011]
Here, the curing agent air mixed fluid supply means supplies the curing agent into the atomizing air passage from a curing agent supply passage opening which is opened in the middle of the atomizing air passage communicating with the curing agent air mixed fluid ejection port. It is desirable to mix with atomizing air. In addition, in order to make the mixing of the main agent and the curing agent more uniform, an auxiliary jet for ejecting the curing agent air mixing fluid along the side of the flat spray pattern of the main agent on a further extension line of the curing agent air mixing fluid ejection port. Preferably, an outlet is provided.
[0012]
[Action]
The operation of the present invention will be described with reference to the drawings in comparison with the prior art.
[0013]
FIG. 1 is a schematic view showing the arrangement and spray pattern of the jet ports of the two-liquid mixing air mix gun of the present invention, and FIG. It is an example with a pattern.
[0014]
As shown in FIG. 6, the arrangement of the ejection ports of the prior art is such that the second air holes B, B are formed on a line m that intersects at right angles to the major axis of the main agent spray opening A for spraying the main agent opened in a lip shape. One air hole C, C is located symmetrically with respect to the main agent spray port A. The main agent is sprayed from the main agent spray port A in a fan shape with a cross-section elliptical like a spray pattern P in a direction of an arrow a flat along a plane S including the major axis of the lips. Here, the hardener mixed airflow c, c is injected from the first air holes C, C, and collides with the air b, b injected from the second air holes B, B at the point X to form the hardener. Since the mixed air flows c, c are expanded as indicated by the dotted lines (the dotted line of the expanded c below the S surface is omitted), the main agent and the curing agent can be uniformly mixed. However, in this method, the mist is scattered around the nozzle in order to collide the hardener mixed gas stream c and the air b at the point X, which is a problem.
[0015]
On the other hand, in the present invention shown in FIG. 1, each ejection port of the air mix gun has an extension line of the long diameter of the main ingredient spray port A, which is a lip-shaped opening of the main ingredient spray port A and the curing agent air mixed fluid ejection ports D, D. 1 on both sides. Then, the hardening agent air mixed fluids d and d are jetted from the hardening agent air mixed fluid jetting port D so as to intersect the spray pattern P of the main agent on the same plane S, and the main agent and the hardening agent are mixed.
[0016]
Since the two-part mixing air mix gun of the present invention has the jet ports arranged as described above, there is no collision of airflow as generated at the point X in FIG. Does not occur. Therefore, there is no need for frequent nozzle cleaning, and the resulting coating film is less likely to cause uneven curing, so that the two-component mixing air mix gun is suitable for long-time operation.
[0017]
In order to make the concentration of the curing agent in the coating film uniform, it is preferable to provide an auxiliary ejection port for the curing agent air mixed fluid as shown in FIG. Since the concentration of the curing agent at the center of the pattern P may be higher than that at the end only with the mixed fluid from the curing agent air mixed fluid ejection ports D and D, the curing agent air mixed fluid is supplied from the auxiliary ejection ports E and F. Is ejected along the edge of the pattern P, whereby the concentration of the curing agent can be made more uniform. In addition, by increasing the air pressure of the hardener-air mixed fluid from the auxiliary ejection port, the spread of the pattern P can be suppressed.
[0018]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIG. 3 shows the arrangement of the ejection ports of this embodiment. FIG. 3 is a partial schematic front view of the atomizing head of the present embodiment. With the lip-shaped main agent spray port A as the center, the hardening agent air mixed fluid ejection ports D, D having a circular cross section are located on both sides on the extension of the major axis direction of A. Auxiliary ejection ports E and F for the curing agent air mixed fluid are provided close to each other at a position further away from the main agent spraying port A of the curing agent air mixed fluid ejection ports D and D.
[0020]
FIG. 4 is a partial cross-sectional view showing the tip 1 of the spray gun. The tip 1 is composed of a head main body 1a and an ejection portion 1b for ejecting an airflow of a main agent or a curing agent air mixture. The head main body 1a includes a main agent supply unit and a curing agent air mixed fluid supply unit. The main agent supply means includes a nozzle base 3 in which a paint chamber 2 is formed at a central portion, a valve seat 6 is provided at a rear end, and a tip of a needle valve 7 contacts and separates to control the ejection of paint. A main agent supply passage 8 communicates with the paint chamber 2 of the nozzle base 3 and receives the main agent from below. A needle valve gasket 4 and a gasket pusher 5 are incorporated on the rear side of the nozzle base 3, and a valve port 9 connected to a valve seat 6 is opened in the center of the front end side of the nozzle base 3, and a tip end of the nozzle base 3 is a tip. It is in contact with the chip 11 incorporated in the holder 10. Further, an adapter 19 is fitted to the nozzle base 3, and the adapter 19 is incorporated with the tip holder 10 so as to form an air gap 20.
[0021]
The hardener-air mixed fluid supply means is composed of an air passage 15 and a hardener supply means 16 screwed into the head main body 1a. The supply port 18 of the curing agent supply passage 17 of the curing agent supply means 16 faces the air passage 15.
[0022]
The ejection portion 1b includes a tip holder 10 in which a tip 11 for spraying the main agent is incorporated, an air cap 12, and a cover 13 for detachably screwing the air cap 12 to the head main body 1a.
[0023]
The tip 11 is known to be used for airless spray, and its outline is shown in FIG. (A) is a schematic view of the tip of the chip 11 as viewed from the front, and the central ellipse shows the lip-shaped opening 30. (B) shows a schematic sectional view of the chip 11. That is, the main agent spray opening A opened in a lip shape by forming a groove 31 having a V-shape or a cross-sectional shape close to the outside from a hole 32 having a sphere or a shape close to the inside thereof, and spraying a high-pressure paint It is made of carbide (tungsten carbide and ceramics) so that it can withstand.
[0024]
Further, mixed fluid passages 14 are formed in the tip holder 10 on the extension of the major axis of the lip-shaped opening A of the tip 11, and the hardener air mixed fluid ejection ports D are opened. In the air cap 12, auxiliary jet ports E and F are symmetrically opened on both sides of the main agent spray port A on a further extension of the jet ports D and D.
[0025]
The chip holder 10 forms a gap a 21 by fitting with the air cap 12, and forms a gap 20 by facing the adapter 19. The gap 21 and the gap 20 are communicated with each other by passage holes 23, 23 formed in the flange portion of the chip holder, and are jetted by the passage 22 connected to the air passage 15, the gap 20, and the mixed fluid passage 14. A hardener-air mixed fluid passage communicating with the outlet D is formed. Further, the gap B 20, the passage hole 23, and the gap A 21 form a hardener-air mixed fluid passage communicating with the auxiliary ejection ports E and F.
[0026]
Next, this operation will be described. First, when a trigger (not shown) is pulled, an air valve (not shown) opens and only air is ejected from each of the ejection ports (D, E, F). Next, a hardening agent control valve (not shown) is pulled, and the hardening agent is fed into the air passage 15 from the supply port 18 through the hardening agent supply passage 17, and the air flow already supplied to the air passage 15 The mixture is atomized to form a curing agent air mixed fluid. Furthermore, the needle valve 7 of the main agent is opened, and the main agent squirts from the lip-shaped opening A of the tip 11. Then, the curing agent air mixed fluid is ejected from the ejection ports D, D through the flow path 22, the gap B 20, and the mixed fluid passage 14 toward the center of the ejection pattern of the main agent, so that atomization is promoted and the main agent is mixed with the main agent. The curing agent is mixed.
[0027]
Further, since the air gap 20 and the air gap 21 communicate with each other through the passage holes 23, 23, the curing agent air mixed fluid is also ejected from the auxiliary ejection ports E and F.
[0028]
In this way, a uniform mixture of the base material and the curing agent is obtained. On the other hand, since no mist is scattered, problems such as uneven curing of the coating and contamination of the nozzles do not occur.
[0029]
[Test example]
The results of a spray putty coating test using the two-part mixed air mix gun of the present invention will be described.
[0030]
(Spray condition)
Using the two-part mixed air mix gun of the present invention (model: 25C05, discharge amount of main agent: 1250 ml / min), main agent pressure: 6 MPa, hardening agent atomizing air pressure: 0.2 MPa, hardening agent pressure: 0.3 MPa The spray putty application test was performed with a curing agent discharge amount of 25 ml / min and a mixing ratio of the main agent and the curing agent of 50: 1. The main agent was polyester putty for spray (Natco), and the curing agent was methyl ethyl ketone peroxide for spray putty (Natco).
[0031]
(Test method)
1) Confirmation of curing unevenness of coating film Spray putty was applied to a sample plate with the aim of a film thickness of 100 μm, and poor curing and uneven curing of the coating film were evaluated. One hour after the application, the hardness of the coating film was evaluated according to JIS K5400 “General Paint Test Method”, and a pencil hardness of H or more was evaluated as acceptable.
2) Confirmation of coating film thickness A coating operation was performed at a gun speed in consideration of practical efficiency, and the thickness of the obtained coating film was measured. The above-mentioned spray putty was applied to a sample plate separated by a certain distance at a practical gun moving speed, and the average film thickness was measured for each reciprocation of the gun.
3) Measurement of continuous usable time The spray putty was continuously used in a coating method of 5 minutes / cycle of spraying for 1 minute and pausing for 4 minutes, and the time during which poor curing and uneven curing occurred in the spray putty coating film was measured.
[0032]
Each sample plate sprayed every 5 minutes and sprayed for 1 minute was left for 1 hour, and the coating film hardness was measured in the same manner as in 1). The presence or absence of curing unevenness or curing failure was evaluated, and the continuous usable time was confirmed.
[0033]
(Test results)
1) Confirmation of curing unevenness of the coating film The coating film after 1 hour had not been damaged at a pencil hardness of less than H, and no curing unevenness or poor curing was recognized.
2) Confirmation of coating film thickness The average film thickness in one application (one reciprocation of the gun) was 55.6 μm, and the average film thickness in two applications (two reciprocations of the gun) was 87.2 μm. .
3) Measurement of continuous usable time The continuous usable time was 5 hours and 10 minutes. That is, No. 1 to No. Up to 62 samples, no curing unevenness or poor curing was observed. On the other hand, in the comparative example (type in FIG. 6), curing failure occurred in 1 hour and 40 minutes.
[0034]
If spraying is continued while the nozzle is very dirty, the putty (paint) cured on the nozzle surface disturbs the spray pattern and leads to poor curing of the coating film. The result was obtained.
[0035]
【The invention's effect】
As described above, in the two-part mixed air mix gun of the present invention, the spraying of the main agent is an airless spray, and the curing agent contained in the compressed air is mixed with the airless spray. The performance is improved. The atomization state of the main agent can provide a fine and stable pattern by using compressed air in combination. Furthermore, since the hardener is mixed on the same plane as the spray pattern of the hardener in the form of a hardener air mixed fluid immediately after the hardener is ejected from the nozzle tip, the hardener is piggybacked on the main agent diffusion process and uniformly mixed. At the same time, there is no scattering of mist, and no problems such as stains on the nozzles, uneven curing of the coating film, or poor curing do not occur. As a result, a long-time continuous coating operation becomes possible, and remarkable improvement in workability can be realized.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an arrangement of spray ports and a spray pattern according to the present invention.
FIG. 2 is an explanatory diagram showing an arrangement of spray ports of the present invention having an auxiliary spray port and a spray pattern.
FIG. 3 is a partial schematic front view showing an arrangement of a jet port of the two-liquid mixing air mix gun of the present invention.
FIG. 4 is a partial schematic cross-sectional view of a tip portion of a two-part mixed air mix gun of the present invention.
FIG. 5 is an explanatory diagram of a nozzle chip. (A) is a front view and (B) is a schematic view of a cross section.
FIG. 6 is an explanatory diagram showing the arrangement of spray ports and the spray pattern according to the related art.
It is.
[Explanation of symbols]
2: paint chamber 7: paint needle valve 8: base agent supply path 10: tip holder 11: tip 12: air cap 13: cover 15: air path 17: curing agent supply path 19: adapter 20: gap b 21: gap a A: Main agent spray port B: Second air hole C: First air hole D: Hardening agent air mixed fluid jet port E, F: Auxiliary jet port P: Spray pattern S: Plane including major axis of A

Claims (3)

A lip-shaped opening of the main agent spray opening, a main agent supply means for supplying the main agent to the main agent spray opening, a hardening agent air mixed fluid outlet, and a hardening agent air mixed fluid supplied to the hardening agent air mixed fluid outlet Curing agent air mixed fluid supply means, and a two-component mixed air mix gun,
The hardening agent air mixed fluid ejection ports are respectively located on both sides on an extended line of the major axis of the main agent spray opening opened in a lip shape, and the hardening is performed so as to intersect on a plane of a flat spray pattern of the main agent. A two-part mixed air mix gun, wherein a main agent and a curing agent are mixed by ejecting an agent-air mixed fluid. The curing agent air mixed fluid supply means supplies the curing agent from a curing agent supply passage opening which is opened in the middle of an atomization air passage communicating with the curing agent air mixture fluid ejection port, and mixes with the atomization air. The two-part mixed air mix gun according to claim 1, wherein The two-component mixing according to claim 1 or 2, further comprising an auxiliary ejection port for ejecting the curing agent air mixed fluid along the side of the flat spray pattern of the main agent on the extension line of the curing agent air mixed fluid ejection port. Air mix gun.

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