JP2000301032A - Coating applicator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to stably form a flat spraying pattern made uniform in the distribution density of coating material particles while maintaining high coating deposition efficiency, to paint a particularly wide surface to be coated at an even and uniform coating film thickness and to greatly improve painted article quality and painting working performance. SOLUTION: An elliptic contraction port 4 from which a mixture composed of a high-pressure coating material and high-pressure air is discharged is formed in a high-pressure chamber where a coating material inlet 10 and an air introducing port are opened. A tapered or paralleled guide part 5 which is formed by flaring sectorial walls having a sectorial groove shape Y in a major axis direction and facing each other toward the discharge side is formed on the discharge side of the contraction port 4. The opening angle of the guide part 5 is specified to 50 to 120 deg., the ratio a/b of the length b in the major axis direction to the length a in the minor axis in the contraction part to 0.05 to 0.75 and the length a in the minor axis direction to 0.4 to 3.0 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an applicator capable of spraying paint with a flat spray pattern having a wide pattern width and a uniform density while maintaining excellent coating efficiency.

[0002]

2. Description of the Related Art In recent years, there has been proposed, for example, Japanese Patent Application Laid-Open No.
No. 398 has been proposed. As schematically shown in FIG. 14, a high-pressure paint and high-pressure air are introduced into a high-pressure chamber a for mixing through a throttle port b having a gradually reduced cross-sectional area. The nozzle portion c having a spread on the side is connected.

In this configuration, the high-pressure air in the pressurized mixture flows near the supersonic speed while expanding in the nozzle portion c while flowing through the nozzle portion c through the throttle port b. Be faster. At this time, the paint is also entrained in the high-speed air and is accelerated while being atomized, and the paint particles blown out from the nozzle portion c have sufficient kinetic energy by themselves and advance linearly. On the other hand, in the case of air, the kinetic energy changes to pressure at the exit of the nozzle portion c and the flow velocity is lost, so that substantially only the paint particles can collide with the surface to be painted without accompanying the gas wake.

[0004] Therefore, for example, while the coating efficiency in air spray coating in which the coating particles are carried by an air flow is about 30%, it is possible to improve the coating efficiency to about 90 to 97%. Become. Moreover, since the kinetic energy of the paint particles themselves is high, they are less susceptible to air, and therefore have the advantage that they can be applied even from a long distance of about 1 m.

[0005]

However, even in the above-mentioned coating method, in order to coat a wide area with a uniform thickness and good workability, a flat spray pattern having a wide pattern width is required. Is required, especially
When applying to a large object to be coated such as a hull, a building, or the like by making the most of the advantage that the coating can be performed from a long distance, it is important to secure a flatter spray pattern. However, as described above, since the method itself is completely different from an air spray gun, etc., like an air spray gun,
It is difficult to change the spray pattern by a technique such as ejecting pattern air from the corners, and there is a possibility that advantages such as coating efficiency may be impaired.

Therefore, in the above-mentioned method, it is necessary to adopt a novel structure in order to obtain a flat spray pattern while keeping the distribution density of the paint particles uniform.

Therefore, the present invention is based on the fact that the throttle opening is formed in an elliptical shape, and on the discharge side thereof, a sector-shaped groove-shaped guide portion which opens in the longitudinal direction of the throttle opening is formed, without deteriorating the above advantages. A coating tool that can stably form a flat spray pattern with a uniform distribution density of coating particles and can apply a uniform coating thickness with good workability over a wide surface to be coated. It is intended to be provided.

[0008]

Means for Solving the Problems In order to achieve the above object, among the inventions of the applicator of the present invention, a first aspect of the present invention is a paint inlet through which high-pressure paint flows, and an air inlet through which high-pressure air flows. Is formed in the high-pressure chamber where the mixture of the high-pressure paint and the high-pressure air is discharged, and the aperture is formed in an elliptical shape. On both sides from the central axis of the mouth, a tapered or parallel guide portion is formed, which has a fan-shaped groove shape that opens in the longitudinal direction of the throttle port and widens the facing fan-shaped wall toward the discharge side. .

According to a second aspect of the present invention, the intersection of the throttle opening and the fan-shaped wall is curved toward the discharge side.

According to a third aspect of the present invention, the applicator has a spray gun shape provided with a needle valve for opening and closing a paint inlet.

According to a fourth aspect of the present invention, the opening angle α of the guide portion is 50 to 120 °, and the ratio a / b of the length b in the long axis direction to the length a in the short axis direction of the throttle portion is 0.05 to 100 °. 0.75,
In addition, the length a in the short axis direction is 0.4 to 3.0 mm.

According to a fifth aspect of the present invention, the guide section is characterized in that the angle β between the fan-shaped walls is 0 to 15 °.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an applicator 1 of the present invention,
In this example, the sprayer is formed as a so-called spray gun. In the present embodiment, the applicator 1 has a throttle port 4 at a front end of a gun body 2 in a high-pressure chamber 3 into which high-pressure paint and high-pressure air flow and mix. Head section 6 having a sector-shaped groove-shaped Y guide section 5 connected thereto
Is provided.

The gun body 2 has an air flow passage 9 which communicates with an air inlet 7 opened in the high-pressure chamber 3 and guides high-pressure air from a high-pressure air supply source 50 to the high-pressure chamber 3; A high-pressure paint from a high-pressure paint supply source, which guides the high-pressure paint from the high-pressure paint supply source to the high-pressure chamber;

The air flow path 9 and the paint flow path 11 are provided with an air valve 13 and a paint valve 14 for sequentially opening and closing the flow paths 9 and 11 by a pulling operation to the trigger 12, respectively. In this example, the paint valve 14 is sequentially opened after the air valve 13 is opened by the pulling operation, and the air valve 13 is sequentially closed after the paint valve 14 is closed by the pullback operation.

The pressure P1 of the high-pressure paint and the pressure P2 of the high-pressure air are substantially equal.
It is set to a range of 2.0 MPa, for example, 1.0 MPa. Here, “substantially equal” means that the ratio P2 / P1 =
In the range of 0.90 to 1.10, it is preferable that P2 ≧ P1 in order to prevent the high-pressure paint from flowing back into the air passage 9.

In this embodiment, as shown in FIG. 13, an air compressor 52 is used as the high-pressure air supply source 50.
And a booster 53 for fully pressurizing the air prepressurized by the air compressor 52 to a pressure P2 (1.0 MPa in this example). High pressure paint supply source 5
The booster 5 includes a reciprocating pump 54 such as a diaphragm pump or a plunger pump.
One of the high-pressure air of the pressure P2 output from 3 is connected to the reciprocating pump 54 as pump driving air. Therefore, in this example, P1 can be set as P2. The high-pressure air supply source 50 and the high-pressure paint supply source 5
Reference numeral 1 denotes a unit that is integrally and portablely mounted on a trolley 55 having wheels and the like to enhance work efficiency.

Next, the applicator 1 will be described in detail.
As shown in FIG. 1, the gun body 2 has a pistol shape in which a body portion 32 is disposed at an upper end of a handle portion 31.
Before and after the trunk body 32A to which the trigger 12 is pivoted,
A rear trunk portion 32R to which the handle portions 31 are connected and a front trunk portion 32F to which the head portion 6 is attached are arranged.

The air passage 9 is provided, for example, with a handle 31.
From the air intake 34 provided at the lower end of the rear trunk portion 32
It includes an inflow hole 36 extending to a valve housing hole 35 formed through the front and rear of R, and a throttle valve 37 that can adjust the air flow rate by an adjusting screw at the lower end of the handle 31 is interposed in the inflow hole 36. The valve storage hole 35 is a hole that stores the air valve 13, and includes front and rear air chambers 35 </ b> F through a valve seat 39.
35R. In the air chamber 35R after the large diameter side,
The inflow hole 36 is opened and the rear end is sealed with a cap nut.

In the present embodiment, the air valve 13 is a cone-shaped valve portion which can communicate with or shut off the front and rear air chambers 35F and 35R by coming into contact with and separating from the valve seat 39. And a valve shaft 40 bulging at the rear end of the valve shaft 40A. The valve shaft 40 is held in a sealed state and slidably back and forth by a bearing portion 41 at the front end of the valve housing hole 35, and is urged forward by spring means housed between the valve shaft 40 and the cap nut. You.

The air passage 9 is provided in the front air chamber 3.
It has a guide hole 42 extending forward from 5F through the inside of the body 32A, and the tip of the guide hole 42 communicates with an annular air reservoir 43 formed around the high-pressure chamber 3.

Next, as shown in FIG. 2, the head section 6 includes a base fitting 15 mounted in a mounting hole 46 at the front end of the front body portion 32F, and a nozzle cap 16 connected to the base fitting 15. The high pressure chamber 3, the throttle port 4, and the guide portion 5 are formed by these components.

In the present embodiment, the base fitting 15 has a head 15A provided with a fitting recess 15A1 for connecting the nozzle cap 16 at the front end, and is connected to the head 15A and screwed into the mounting hole 46. Body 1 having outer threaded portion 15B1
5B. Further, the air reservoir 43 is formed around the body 15B in a region between the outer screw portion 15B1 and the head 15A.

The base fitting 15 includes the fitting recess 1.
5A1 has an inner hole 19 extending rearward from the bottom surface. The inner hole 19 has an air inlet 7 on its inner peripheral surface and a paint inlet 10 on its rear end. The air inlet 7 penetrates through the body portion 15B, passes through the air reservoir 43, and communicates with the air flow passage 9, and the paint inlet 1
In the present example, the paint flow path 11 extending from the paint inlet 45 provided at the lower end of the front body portion 32F to the rear portion 46A of the mounting hole 46 is conducted to 0.

The paint inlet 10 has a tapered cone-shaped valve seat 10A at the rear end thereof, and the paint valve 14 is formed using the valve seat 10A. The paint valve 14 is
In the present example, the needle valve 20 opens and closes the paint inlet 10.
Through the rear portion 46A of the mounting hole 46, as shown in FIG.
It extends to the lateral hole 47 of the rear trunk portion 32R. The rear end side of the paint valve 14 has a bearing portion 49 at the front end of the lateral hole 47.
And is slidably held forward and backward, and is urged forward by a spring means between a nut fitting provided at the rear end of the lateral hole 47.

The nozzle cap 16 has a cylindrical base 16A fitted into the fitting recess 15A1, and a hemispherical head 16B formed at the front end of the base 16A. In the middle position, the flange part 1
6A1 protrudes. In the present example, the front trunk portion 32
A ring-shaped joint nut 17 (shown in FIG. 2) is screwed to the front end of F, and a flange 17A projecting inward at the front edge of the joint nut 17 engages with the front surface of the flange portion 16A1. Thereby, the nozzle cap 16 is narrowed and fixed in the fitting recess 15A1.

The nozzle cap 16 has a center hole 21 concentric with the inner hole 19.
Reference numeral 1 denotes a cone portion 22 extending in a tapered shape from the inner hole 19 toward the front, a throttle port 4 having a small opening area formed at the tip of the cone portion 22, and a discharge side (front side) of the throttle port 4. ) And a guide portion 5 in the form of a fan-shaped groove. In this example, the high pressure chamber 3 is formed by the inner hole 19 and the cone portion 22.

In the present application, as shown in FIGS. 3 to 7, the aperture 4 is formed in an elliptical shape, and the guide portion 5 is provided on both sides from the center axis J of the aperture 4. 4 is characterized by forming a fan-shaped groove Y which opens in the long axis direction, and furthermore, the opposing fan-shaped walls 23, 23 are formed in a tapered or parallel shape which widens toward the front side.

More specifically, as shown in FIGS. 3 and 7, in this embodiment, the inner peripheral surface 22S of the cone portion 22 forms a conical body V1 having a circular cross section in a direction perpendicular to the central axis J. On the other hand, the inner peripheral surface 5S of the guide portion 5 is formed as an elliptical cone V2 having a vertically long elliptical cross section and tapering toward the rear side.
Therefore, in this example, the constricted portion V1
And the elliptical cone V2 have a lip-shaped three-dimensional shape surrounded by an intersection edge K.

In other words, in this embodiment, the aperture 4 is formed by a curved surface obtained by curving the intersection K1 on the short axis side with the fan-shaped wall 23 toward the front, and is projected on a plane orthogonal to the central axis J. , And when developed on a plane, each has an elliptical shape. Note that, as shown in FIG. 6, the flatness, which is the ratio a / b of the length a of the aperture 4 in the short axis direction and the length b in the long axis direction, in the state of projection on the orthogonal plane, is: In this example, 0.0
5 to 0.75, and the length a is 0.4
It is set in the range of up to 3.0 mm.

Here, "elliptical" means not only an ellipse whose two sides on the long axis side are parallel as in this example, but also FIGS. 8 (A) and 8 (B).
An ellipsoid or an oval body as shown in FIG. 8A, or as shown in FIG.
Various flat shapes such as a shape in which the top portion Re in the major axis direction forms an acute edge can be included.

Further, a cross section Sb in the long axis direction and a cross section S in the short axis direction along the central axis J of the nozzle cap 16 are provided.
a, as shown in FIGS.
The inner peripheral surface 5S is connected to the inner peripheral surface 5S by being bent into an edge shape through the aperture 4. The upper edge 23U and the lower edge 23L of the fan-shaped wall 23 extend in a fan shape from the throttle port 4 toward both sides (in this example, up and down) of the center axis J, and the cross section S
b, that is, the opening angle α of the guide portion 5
Is set in the range of 50 to 120 degrees. The angle β between the fan-shaped walls 23 in the section Sa is significantly smaller than the opening angle α, and is set in a range of 0 to 15 degrees. At 0 °, the shape is parallel, and at other times, it is tapered. The opening angle α and the angle β are constant, so that the contour N of the inner peripheral surface 5S in the cross sections Sa and Sb is formed by a straight line.

In this example, as shown in FIGS. 3, 6, and 7, the fan-shaped wall 23 includes, as a main portion, a fan-shaped flat portion 23S extending in a fan shape from the throttle opening 4 toward the front side. An example is shown.

However, the pulling operation of the trigger 12 opens the air valve 13 and the paint valve 14 in order, and the air intake 34
High-pressure air that has flowed through the air flow path 9 and the paint inlet 4
The high-pressure paint flowing through the paint flow path 11 from 5 flows into the high-pressure chamber 3 through the air inlet 7 and the paint inlet 10 to be mixed. The high-pressure air flows into the high-pressure paint ahead of the high-pressure paint, so that the paint can be gradually sprayed to improve the operability. In addition, the backflow of the high-pressure paint into the air flow path 9 due to the pressure imbalance that tends to occur in the early stage of operation. Can be prevented.

In the present embodiment, a plurality of (six in this embodiment) air inlets 7 are formed at substantially equal intervals in the circumferential direction by forming an annular air reservoir 43 around the high-pressure chamber 3. I have arranged. Therefore, the opening area of each air inlet 7 can be set sufficiently small while preventing the supply amount of high-pressure air into the high-pressure chamber 3 from being insufficient. For example, a large amount of high-pressure air flows from one air inlet 7 at a time. It is possible to prevent the high-pressure paint from becoming foamy, making the mixing of the two non-uniform and making the spraying unstable or discontinuous. The diameter of each air inlet 7 is preferably about 0.2 to 1.0 mm, and the total opening area is preferably about 1 to 10% of the opening area of the paint inlet 10.
If it exceeds 10%, the amount of air becomes excessively large, and finer paint particles are promoted, but the coating efficiency tends to decrease. Conversely, if less than 1%, the paint particles become coarser. However, it can be 10% or more if required.
In this example, a case where the diameter is 0.4 mm and the sum of the opening areas is 2.5% of the paint inlet 10 is illustrated.

Next, when the mixture uniformly mixed in the high-pressure chamber 3 passes through the guide portion 5 through the throttle port 3, it rapidly expands to a high speed close to supersonic speed. At this time, since the throttle port 3 has an elliptical shape, and the guide portion 5 has a fan-shaped groove Y, the high-pressure paint is accelerated while being atomized, and while maintaining sufficient kinetic energy, FIG. As shown in (1), it is possible to discharge radially from the throttle port 3 with an extremely flat spraying pattern Q. Also spraying pattern Q
Inside, the distribution density of the paint particles becomes substantially uniform, so that a wide coating surface can be applied with uniformity and uniform coating thickness with good workability.

By adopting the above structure, the flatness ratio QW which is the ratio of the pattern length QL to the pattern width QW is obtained.
/ QL can be flattened to 20% or less, and the pattern length Q is 1.0 times or more, and more preferably 1.5 times or more the spray distance L.
It is also possible to secure L. In order to keep the distribution density of the paint particles uniform, the flattening rate QW / QL is required.
Is preferably maintained at 5% or more.

In the applicator 1, since the intersection edge K has an edge shape, the mixture is disturbed, for example, the cross-sectional shape of the cone portion 22 and the guide portion 5 changes abruptly at the throttle port 3. The mixing is further homogenized and the fineness of the paint is promoted.

If the aperture 3 is not elliptical or the guide 5 is not a sector-shaped groove Y,
The high-pressure paint becomes coarse and the kinetic energy becomes insufficient, resulting in a decrease in the coating efficiency. In addition, the flat spray pattern Q cannot be formed, or the distribution density of the paint particles in the pattern becomes uneven. Or inconveniences such as

In particular, in order to obtain a flat spray pattern Q having a uniform distribution density, as described above, the flatness ratio a / b at the aperture 4 is 0.05 to 0.75, The angle α is 50 to 120 ° and the angle β between the sector walls 23
Is preferably 0 to 15 °. Note that the angle β
Is more preferably 5 to 15 ° from the viewpoint of coating efficiency.

FIGS. 10 to 12 show another embodiment of the present invention. As shown in FIG.
Is also formed by an elliptical cone V3, and the aperture 4 is formed by an intersection edge K of the guide portion 5 with the elliptical cone V2. At this time, the aperture 4 is formed in an elliptical shape in a plane perpendicular to the central axis J. In this example, the elliptical cone-shaped body V3 has a rear end having a circular cross section and an elliptical cross section having a flattened shape toward the front end.

As shown in FIG. 11, the throttle port 4 is opened in an elliptical shape in a plane perpendicular to the central axis J, while the throttle port 4 and the inner peripheral surface 5S of the guide portion 5 are aligned in the plane. Connected with a step 25, that is, the elliptical cone V formed by the guide portion 5
(2) The sectional shape of the rear end and the aperture 4 may be different. In FIG. 11, for the sake of convenience, the cross section of the guide portion 5 is drawn in a rectangular shape.

As shown in the front view of FIG. 12, the fan-shaped wall 23 does not include the fan-shaped flat portion 23S, but is curved outwardly in a convex shape.
It may be formed in S1. Also, the throttle port 3 and / or the guide section 5
Is preferably formed or coated with a superalloy such as titanium in order to prevent wear with high-speed paint. Thus, the applicator 1 of the present application can be changed to various modes.

[0044]

As described above, in the applicator of the present invention, the throttle port is formed in an elliptical shape, and a fan-shaped groove-shaped guide portion which opens in the long axis direction of the throttle port is formed on the discharge side. Therefore, the coating density is uniform, and the distribution density of the coating particles is uniform, while ensuring various advantages such as high coating efficiency, application from a long distance, which is hardly affected by air, and application to corners. A stable spray pattern can be formed stably. as a result,
In particular, it is possible to apply a uniform coating thickness evenly on a wide surface to be coated, and it is possible to greatly improve coating quality and coating work performance.

[Brief description of the drawings]

FIG. 1 is a sectional view of an applicator according to one embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing the head portion.

FIG. 3 is a perspective view showing a nozzle tip.

FIG. 4 is a cross-sectional view in the major axis direction of the nozzle tip.

FIG. 5 is a cross-sectional view in the short axis direction of the nozzle tip.

FIG. 6 is a front view of the nozzle tip.

FIG. 7 is a perspective view showing a throttle port together with an inner peripheral surface of a guide portion and an inner peripheral surface of a cove portion.

8A, 8B, and 8C are front views showing other shapes of the aperture.

FIG. 9 is a diagram illustrating a spray pattern.

FIG. 10 is a perspective view showing another embodiment of the aperture stop.

FIG. 11 is a perspective view showing still another embodiment of the aperture stop.

FIG. 12 is a front view showing another embodiment of the fan-shaped wall.

FIG. 13 is a diagram illustrating a high-pressure air source and a high-pressure paint source.

FIG. 14 is a cross-sectional view illustrating a conventional technique.

[Explanation of symbols]

 Reference Signs List 3 High-pressure chamber 4 Restrictor 5 Guide part 9 Air inlet 10 Paint inlet 20 Needle valve 23 Sector wall J Center axis K Intersection edge Y Sector groove

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[Procedure amendment]

[Submission date] January 27, 2000 (2000.1.2
7)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008]

Means for Solving the Problems In order to achieve the above object, among the inventions of the applicator of the present invention, a first aspect of the present invention is a paint inlet through which high-pressure paint flows, and an air inlet through which high-pressure air flows. Is formed in the high-pressure chamber where the mixture of the high-pressure paint and the high-pressure air is discharged, and the aperture is formed in an elliptical shape. -out opening in the longitudinal direction of the diaphragm opening from the central axis of the mouth on either side
And forming a guide portion of the sector groove having a fan-shaped wall facing, yet the opening angle α in the long axis direction of the cross-section of the inner guiding
50 to 120 ° and the sector shape in a cross section in the short axis direction
It is characterized in that the angle β between the walls is 0 to 15 ° .

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction contents]

[0011] according to claim 4 invention, the ratio a / b of the length b of the major axis direction of the short axis direction of the diaphragm Ri portion to the length a 0.05 to 0.75, and the minor axis Length a is 0.4 ~
It is characterized in that it is 3.0 mm.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

The invention according to claim 5 is characterized in that the aperture and the front
The intersection with the fan-shaped wall is edge-shaped.
And

Claims (5)

[Claims] An aperture having a small opening area through which a mixture of high-pressure paint and high-pressure air is discharged into a high-pressure chamber in which a paint inlet into which high-pressure paint flows and an air inlet through which high-pressure air flows. And the aperture is made elliptical,
On the discharge side of the throttle port, a tapered or parallel guide is formed on both sides from the central axis of the throttle port in the form of a sector-shaped groove that opens in the longitudinal direction of the throttle port, and the opposing sector-shaped walls widen toward the discharge side. An applicator formed with a part. 2. The applicator according to claim 1, wherein an intersection edge of the throttle opening with the fan-shaped wall is curved toward a discharge side. 3. The applicator according to claim 1, wherein said applicator has a spray gun shape having a needle valve for opening and closing a paint inlet. 4. An opening angle α of said guide portion is set to 50 to 120.
比, the ratio a / b of the length b in the long axis direction to the length a in the short axis direction of the narrowed portion is 0.05 to 0.75, and the length a in the short axis direction is 0.4 to 3.0 mm. The applicator according to any one of claims 1 to 3, wherein 5. The guide section has an angle β between the fan-shaped walls of 0.
The applicator according to any one of claims 1 to 4, wherein the angle is from 15 to 15 °.