JP3148646B2 - Coating material circulation supply type spray gun - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly sedimentable slurry liquid which is obtained by mixing powder such as glass powder, ceramic powder, and abrasive with water, alcohol, or a synthetic resin liquid. To a coating material supply mechanism of a spray gun when spray coating is performed by air spray.

[0002]

2. Description of the Related Art A coating solution, such as a glaze in the ceramic industry, an automatic application of an abrasive to a rotating buff in buff polishing, or a release material to a mold in casting, is performed by a solution of the coating material. In order not to affect the above, it is made as a slurry-like liquid by mixing with water, alcohol or a low-viscosity chemical solution. For this reason, the powdery aggregate mixed into the coating material has a high sedimentation property, and precipitates as soon as the flow stops, thereby producing a viscous solidified precipitate. And, even if the coating material is flowing, if there is a weir formed by a joint or the like in the flow path, or if there is a stagnation point of the fluid, a precipitate is generated in that portion, and the precipitate is generated. There is a problem that the precipitate is mixed in the flow path while solidifying and clogs the flow path or the paint nozzle.

[0003] When spraying the above coating material, the paint gun is connected to two paint hoses, forward and return, to form a circulation circuit, which is circulated and supplied at a flow rate at which the coating material is not settled. We supply while making it. The pump for circulating supply is pumped by a diaphragm pump, a centrifugal pump, or a tube pump that pumps the tube while sequentially crushing the tube without a sliding portion in the pump section.

As the spray gun used in the above-mentioned coating apparatus, a generally used automatic spray gun or a hand-held air spray gun is used. A Y-joint is attached to a paint supply joint, and a circulation circuit is used. Alternatively, a circulation circuit is formed by connecting the paint hose to the two joints by piercing the outward and return flow paths in the spray gun body. When the forward and return flow paths are perforated in the spray gun main body, the perforations are perpendicular to the paint center flow path formed around the needle valve of the spray gun. The paint nozzle and the air cap are provided with the standard ones described above.

[0005] In the configuration of the coating apparatus for forming a circulation circuit in the above-mentioned general spray gun, when a circulation circuit is formed so as to be orthogonal to the paint center flow path of the spray gun body, the needle valve seat portion of the paint nozzle and the needle valve seat portion of the paint nozzle are formed. During the circulation flow path, for example, the inside of the nozzle becomes only the supply flow path of the outward path, and when the ejection from the paint nozzle is stopped, the flow of the paint center flow path inside the nozzle stops, and the sedimentation of the coating material is stopped. At the beginning, clogging of the paint nozzle occurs at the time of re-ejection. The occurrence of the clogging varies depending on the physical properties of the coating material. In particular, in the case of a coating material with severe precipitation, there is a problem that clogging frequently occurs even when the above-mentioned circulation circuit is provided, making it unusable.

[0006] A coating apparatus for applying a coating material obtained by mixing the above-mentioned glass powder, abrasive material, fine-grained sand of a mold release material and the like greatly differs depending on an object to be coated. There are relatively many cases such as spraying, spraying one or more spray guns in a narrow place and spraying from a short distance, or intermittently spraying a small amount of coating. Therefore, a small-sized automatic spray gun is desired in view of the fact that a large number of automatic guns are arranged and sprayed, or are arranged in a narrow place, or the minute amount is intermittently sprayed. There are many known small automatic spray guns, but none of them is suitable for the coating material.

[0007] Further, since the coating material is formed by using powder such as glass powder or abrasive as an aggregate, the sheet portion of the coating nozzle is quickly worn out, and a general coating nozzle made of stainless steel or quenched steel is used. However, there is a problem that the wear is fast and the durability is not high.

Further, the aggregate of the coating material bites into the packing sliding portion in the needle valve packing portion for sealing between the operating portion for operating the needle valve and the paint flow passage, so that material leakage occurs early. Have a problem.

[0009]

SUMMARY OF THE INVENTION The present invention relates to glass powder,
In an air spray gun that supplies a coating material supply flow path as a circulation circuit of a coating device that spray-coats a ceramic coating powder or a slurry-like coating material in which an abrasive or the like is mixed with a solution, the aggregate of the coating material is removed. The sedimentation is fast, the coating material having high abrasion, the coating material flow path and, by the material precipitated in the pool,
An object of the present invention is to solve the problem of clogging a paint nozzle.

Another object is that the material having high abrasion properties causes the paint nozzle and the needle valve seat part to be worn out at an early stage. Therefore, it is necessary to take new measures to improve this.

[0011]

SUMMARY OF THE INVENTION The present invention provides a paint nozzle,
A coating device that circulates a slurry-type coating material obtained by mixing highly sedimentable powder aggregate with a solution to a spray gun having a needle valve and a blowing air cap by a pump such as a diaphragm pump or a tube pump. In the air spray gun provided in the coating material flow path to circulate and supply to the spray gun body is an inclined flow path toward the paint nozzle needle valve seat portion, the paint nozzle needle valve seat portion as the intersection vertex, The forward path and the return path of the circulation supply flow path form a V-shaped flow path, and the opening of the paint nozzle sheet of the paint nozzle / needle valve seat portion directly opens at the intersection vertex of the V-shaped flow path. Thus, the spray gun is a spray gun for supplying and circulating a coating material having a flow path without a coating material pool.

Further, when the paint nozzle / needle valve seat portion is pierced at the joint end of the paint nozzle to the spray gun body, the paint nozzle seat of the paint nozzle / needle valve seat portion has abrasion resistance. A coating material circulation supply type spray gun formed by fitting a separate superhard sheet perforated with a superhard material into a recess formed in a base of the paint nozzle.

The present invention also provides a coating material flow path which is circulated and supplied, and a V-shaped flow path is formed with a coating nozzle needle valve seat portion as an intersection vertex. In a small automatic air spray gun in which a separate cemented carbide sheet is provided at a base portion, a needle valve packing attached to the small automatic spray gun has a coating material flow path and a needle valve operating valve. A coating material circulation for supplying a high sedimentation material, which is provided in two stages between the air piston and a material leakage confirmation hole formed in the middle of the two-stage needle valve packing and communicating with the outside air, by a pump. It is a supply type small automatic spray gun.

[0014]

The operation of the present invention will be described with reference to FIG. 1 which is applied to a small automatic spray gun. A circulation supply path (1a) and a return path (1b) are formed in the automatic gun body (1) toward the paint nozzle / needle valve section (2) to form an inclined flow path.
a) and (1b) are V-shaped, and the paint nozzle / needle valve seat (2) is disposed directly in the flow path at the intersection vertex. The super hard sheet (4) of the paint nozzle (5)
A separate chip made of a cemented carbide material, for example, tungsten carbide or a ceramic material, is press-fitted into a recess formed in the base of the paint nozzle (5).
The needle valve (3) comes into sliding contact with the cemented carbide sheet (4), and the application of the coating material is started and stopped by the operation of the needle valve (3). The coating material flowing from the cemented carbide sheet (4) has the same diameter as the nozzle diameter of the coating nozzle (5),
And communicates with the cemented carbide sheet (4).

The above configuration is applicable to a general large automatic gun or a hand-blown gun. Further, the outward path (1a) and the return path (1b) of the circulation flow path may be reverse flow paths. The angle of inclination of the V-shaped flow path may be such that the vertex at which the flow path intersects is the angle at which the liquid flow collides with the paint nozzle / needle valve seat portion (2). Therefore, the forward path (1a) and the return path (1b). Need not be equilateral angles, and the design of the spray gun may be V-shaped, but the angles of the forward path and the return path may be different.

In the above structure, the coating material pumped by the pump flows through the paint hose connection joint (6) to the outward path (1a) of the circulation supply path and toward the paint nozzle / needle valve seat (2). The liquid flow collides, and when the needle valve is closed, the colliding liquid flow is sent from the return path (1b) to the pump section via the paint hose connection joint (7) and circulated. The stirring chamber (1c) where the liquid flow collides with the paint nozzle / needle valve seat (2) is formed with a minimum volume and eliminates the agitation by the liquid flow in order to eliminate the pool of the coating material. The inside of the chamber (1c) is agitated so that a fluid state is always maintained. Then, when the needle valve (3) is opened, the solution and the aggregate are discharged from the stirring chamber (1c) in a state of being completely mixed, and are ejected from a flow path having the same diameter as the paint nozzle. The tip end of the paint nozzle (5) sucks the applied coating material and disperses the coating material with a compressed air flow from a ring-shaped slit on the outer periphery of the tip of the paint nozzle, and conveys the applied material onto the workpiece. I do. When the needle valve is closed, the coating material remaining in the paint nozzle passage is sucked by the suction force of the compressed air, thereby preventing material dripping and sedimentation from the paint nozzle opening.

In the cemented carbide sheet (4), since the aggregate mixed with the coating material is a hard material such as an abrasive, the opening / closing sliding with the needle valve seat portion causes an instantaneous change in the steel material. Since it is worn and causes sheet failure, a member made of a super-hard material as described above is separately press-fitted into the base of the paint nozzle.

In the small automatic gun shown in FIGS. 1 and 3 and 4, a piston chamber (1d) surrounding a piston (8) for operating a needle valve (3), and a stirring chamber (1).
Needle valve packing (9) for hermetically partitioning c)
Are arranged. Conventionally, a small automatic gun has been sealed with a single needle valve packing (9) in order to make the automatic gun as small as possible. However, in the coating material used in the present invention, packing was greatly worn by the aggregate, and the problem of packing leakage often occurred. Therefore, when the present invention is applied to a small automatic gun, the needle valve packing is provided with a first needle valve packing (9) for sealing the stirring chamber (1c) side of the coating material flow path, and a piston chamber (1d) side. Needle valve packing (10) for sealing piston working air to the valve
A two-stage needle valve packing is provided, and a hole (11) for confirming the leakage of air to the outside air is provided between the first and second two-stage needle valve packings. In addition to preventing the leaked coating material from entering the piston chamber (1d), the leak from the first needle valve packing can be confirmed from outside the small automatic gun. It is possible to exchange.

Also, in the small automatic spray gun, the paint hoses can be gathered rearward because the paint joints 6 and 7 are linearly attached to the V-shaped flow paths (1a) and (1b) for circulating supply. The joints are located behind the air cap surface, and the joints and paint hoses are less contaminated. Thus, an effect that maintenance becomes easy can be obtained.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A temporary embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a small automatic spray gun according to the present invention in which a coating material flow path for circulating supply to a spray gun body is an inclined flow path toward a paint nozzle needle valve seat. It is the side appearance figure seen from the cap side. As an example to which the present invention is applied, a mechanism structure of a small automatic spray gun will be described with reference to the drawings. However, overlapping parts described in the section of operation are omitted in principle. In the drawings, the same components will be described with the same reference numerals.

In FIG. 1, a paint nozzle 5 is hermetically screwed and joined to the automatic gun body 1 at the tip of the automatic gun.
An air cap 12 is provided on the paint nozzle 5 with a cap cover 13.
And set on the automatic gun body 1. A ring-shaped slit 12a is formed between the air cap 12 and the outer periphery of the tip end of the paint nozzle 5, and the compressed air is sprayed to disperse the coating material discharged from the paint nozzle 5 and to carry and spray it. The air cap 12 has a plurality of auxiliary holes 12b for preventing material from adhering to the front surface of the cap and for enlarging the pattern shape. The air cap 12 of the present embodiment is an air cap exclusively for round blowing.

In the paint nozzle 5, a through hole 5a is formed at the center with the same diameter as the paint nozzle diameter. In a normal paint nozzle 5, the needle valve extends to the tip of the discharge port, and the paint center flow path has a large diameter. However, the paint nozzle 5 of the present invention has a In order to prevent this, it penetrates the center of the paint nozzle with the same diameter as the paint nozzle diameter. An air passage 5b is pierced on the outer peripheral side of the paint nozzle 5,
The compressed air is supplied to the air cap 12 via the air flow path 5b. Then, a cemented carbide sheet 4 made of a cemented carbide material and separately formed is press-fitted into a concave portion formed in the base of the paint nozzle 5 at a base portion of the paint nozzle 5 screwed and joined to the automatic gun body 1. Have been. Further, a tapered sheet that is in sliding contact with the needle valve 3 is formed in the carbide sheet 4. However, the embodiment in which the press-fitting is performed is not limited to the method of mounting the cemented carbide sheet 4. For example, welding is performed on the base of the paint nozzle 5 or the base of the paint nozzle 5 and the automatic gun body 1 are connected. The same effect can be obtained even if airtightly interposed therebetween.

The coating material, which is fed through a paint hose from a diaphragm pump (not shown) suitable for feeding the coating material in the form of a slurry, flows from the paint joint 6 to the outward path 1a of the circulation flow path. Inflow. The forward path 1a is an inclined flow path toward the paint nozzle / needle valve seat part 2 at the sliding contact portion between the carbide sheet 4 and the needle valve 3, and the forward path 1a
The liquid flow discharged from a collides with the paint nozzle / needle valve seat portion 2, and the colliding liquid flow is in the stirring chamber 1c. The coating material is disturbed and the aggregate mixed with the coating material is uniformly dispersed. It is discharged to the through hole 5a of the paint nozzle 5. The coating material in the stirring chamber 1c is returned to the pump side via the paint joint 7 from the return path 1b of the circulation flow path. The flow rate of the coating material flowing through the circulation circuit varies depending on the physical properties of the coating material, but at a speed at which the aggregate does not settle in the flow path, the liquid amount is at least several times the injection amount discharged from the coating nozzle 5. Is constantly circulating, and the flow velocity in the flow path needs to be at least 1 m / s or more.

The needle valve 3 is inserted into the center through hole of the automatic gun body 1 and a first needle valve packing 9 is provided on the stirring chamber 1c side in a recessed portion as close to the stirring chamber 1C of the automatic gun body 1 as possible. Is set to First needle valve packing 9
Is a lip-shaped packing formed by laminating a fluorine-based resin plate and a fluorine-based rubber plate, and the lip of the packing is in sliding contact with the needle valve rod to seal. The lip-shaped needle valve packing has a shape that does not easily bite the aggregate of the coating material.

A piston 8 for operating the needle valve is provided in a piston chamber 1d for operating the needle valve 3.
The piston 8 is slidably fitted in the inner space d, and a Y-shaped packing or the like is fitted in the outer circumferential groove of the piston 8, and the piston 8 reciprocally slides in the piston chamber 1d in an airtight manner. The piston 8 and the needle valve 3 are screwed and fixed integrally by a nut 14. A needle valve spring 15 is set behind the piston 8 with a spring pressing lid 16, and the needle valve 3 is pressed against the carbide sheet 4 by a spring force to close the paint nozzle opening. During the operation of the needle valve, the compressed air from the working air joint shown in FIG. 3 flows into the piston chamber 1 d on the needle valve side of the piston 8 and resists the pressing of the needle valve spring 15.
By operating the piston 8, the needle valve 3 is pulled to open the needle valve, and the coating material is discharged from the through-hole 5a of the coating nozzle.

A cylindrical washer 17 is provided at the bottom of the piston chamber 1d.
Are attached by two screws 21 as shown in FIG. The second needle valve packing 10 is fitted into a cylindrical washer 17. Second needle valve packing 1
Reference numeral 0 denotes an O-ring, which also serves as a seal for compressed air for operating the piston 8 and a function for preventing material from entering the piston chamber 1d when the first needle valve packing 9 causes material leakage. It has a shape. further,
In the cylindrical washer 17, a leak confirmation hole 11 communicating with the outside air through the automatic gun body 1 from the needle valve through hole of the washer 17 is opened at a position relatively close to the first needle valve packing 9. And the first needle valve packing 9
If the material leaks from the automatic gun body 1 through the hole described in detail in FIG. 4, it can be confirmed that the first needle valve packing 9 has leaked.

In the side view from the piston side in FIG.
2 shows the arrangement of the paint joints 6 and 7, the working air joint 18, and the spray air joint 19 described with reference to FIG. 1. The working air is supplied to the piston chamber 1d from the hole formed in the automatic gun body 1 through the washer 17 to operate the piston 8. The blowing air is blown out of the air cap 12 from the hole formed in the automatic gun body 1 through the hole formed in the paint nozzle 5. The support bolt 20 is a support for mounting a small automatic gun. Even when a large number of automatic guns are arranged, the support bolt 20 can be mounted using the support bolt.

FIG. 4 is a cross-sectional view passing from the support bolt 20 shown in FIG. 3 to the center of the automatic gun, and shows a leak confirmation hole 11 between the first needle valve packing 9 and the second needle valve packing 10. It is a thing. In FIG.
Is fixed to the automatic gun body 1 by two screws 21. The inner peripheral groove 1 is formed in the hole of the needle valve 3 that passes through the washer 17.
7a is drilled, and a leak confirmation hole 11 drilled in the automatic gun body 1 through a hole 17b drilled from the inner circumferential groove 17a to the washer 17 is opened.

[0029]

As described above, the present invention has the following advantages.

The coating material flow path to be circulated and supplied to the spray gun is an inclined flow path toward the paint nozzle / needle valve seat portion, and the circulation flow path is a V-shaped flow path in the forward path and the return path. The liquid flow collides with the nozzle / needle valve seat and is agitated, so that the aggregate mixed with the coating material is dispersed uniformly, and the coating material is no longer clogged at the coating nozzle and is sprayed. As a spray pattern, a pattern in which the aggregate is uniformly dispersed is obtained, and the spray pattern can be uniformly applied to the object to be coated.

Since the opening of the paint nozzle / needle valve seat portion is directly opened at the intersection vertex of the V-shaped flow path, even if there is no material reservoir and no spraying of the coating material, the flow path allows aggregate to flow. There is no settling, and there is no clogging of the paint nozzle.

Since the cemented carbide sheet is separately press-fitted into the base of the paint nozzle, a spray gun having a long-term durability can be obtained even with an aggressive aggregate application material.

By applying the present invention to a small automatic spray gun, the needle valve packing is made into two stages, and a leak check hole is provided in the middle, so that if a packing leak occurs, it can be confirmed from the appearance and prompt action can be taken. It is a highly reliable small automatic spray gun that can be used.

In addition, since the paint joint is attached to the V-shaped flow path, the paint hose and the like can be easily gathered rearward, the dirt of the small automatic gun is reduced, and the maintenance is facilitated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a small automatic spray gun to which a circulation supply channel according to the present invention is applied.

FIG. 2 is an external side view from the air cap side in FIG. 1;

FIG. 3 is a side view of the external appearance from the piston side in FIG. 1, showing the arrangement of each joint and a support bolt.

FIG. 4 is a view AA of FIG. 3 showing a leak confirmation hole of the present invention.
It is sectional drawing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic gun main body 1a Outgoing path 1b Return path 1c Stirring chamber 1d Piston chamber 2 Paint nozzle needle valve seat part 3 Needle valve 4 Carbide sheet 5 Paint nozzle 6,7 Paint joint 8 Working piston 9 First needle valve packing 10 Second Needle valve packing 11 Leakage confirmation hole 12 Air cap 20 Support bolt

Claims (4)

(57) [Claims] 1. A slurry-like coating material obtained by mixing a highly sedimentable powder aggregate with a solution is sprayed onto a spray gun having a paint nozzle, a needle valve, and an air cap for spraying, such as a diaphragm pump or a tube pump. In an air spray gun provided in a coating device that circulates and supplies by a pump, a coating material flow path that circulates and supplies to a spray gun body,
Inclined flow path toward paint nozzle / needle valve seat,
With the paint nozzle needle valve seat as the intersection vertex,
An application material circulating supply type spray gun in which the outward and return paths of the circulating supply flow path form a V-shaped flow path. 2. When the coating material flow path to be circulated and supplied to the spray gun body forms a V-shaped flow path with the coating nozzle needle valve seat portion as an intersection vertex, the opening of the coating nozzle sheet is Open directly at the intersection vertex of the flow path,
2. The spray gun according to claim 1, wherein the spray gun has a flow path without a coating material pool. 3. When the paint nozzle / needle valve seat portion is pierced at the joint end of the paint nozzle to the spray gun body, the paint nozzle seat of the paint nozzle / needle valve seat portion has abrasion resistance. The coating material circulation supply type spray gun according to claim 1 or 2, wherein a separate superhard sheet perforated with the superhard material is joined to a base of the paint nozzle. 4. A spray gun which applies the means according to claim 1, 2 or 3 to a small automatic spray gun, wherein a needle valve packing attached to the small automatic spray gun comprises:
High sedimentation material provided in two stages between the coating material flow path and the needle valve operating air piston, and having a material leakage confirmation hole perforated in the middle of the two-stage needle valve packing communicating with the outside air A small automatic spray gun that circulates and supplies the coating material by a pump.