JPH06320072A - Sprayer - Google Patents

Abstract

PURPOSE:To provide a sprayer causing no clogging therein for spraying a liquid easy to separate, such as a glaze. CONSTITUTION:A sprayer 9 has a nozzle body 79 at whose end part is made a nozzle hole 11, a glaze pass 13 for feeding a glaze F to the nozzle hole 11. and a jet air pass 38 for feeding air A to the nozzle hole 11. The air is blown off from an air jet hole 47, causing the glaze F to be jetted from the nozzle hole 11 in a spray. A glaze recovering means 32 for recovering the glaze from the glaze pass 13 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spraying device for spraying a liquid in the form of a spray from a nozzle, and more specifically, a glaze used as a glaze for ceramics or a resin dissolved in a volatile solvent. The present invention relates to a spraying device for spraying a mixed liquid such as varnish.

[0002]

2. Description of the Related Art Heretofore, a spraying device for spraying a highly fluid liquid such as a paint onto a target in a sprayed form using compressed air has been widely used. FIG. 5 shows a cross-sectional view of a conventional spraying device. The nozzle 11 is bored at the left end of the nozzle body 79 bored in the center. The paint joint 14 is formed below the nozzle body 79, and the paint passage 13 which is a hollow portion of the nozzle body 79 and the paint joint 14 are in communication with each other. The paint joint 14 is connected to a paint solenoid valve (not shown) that shuts off the flow of paint. Further, a needle 12 having a conical tip is attached to the nozzle 11 so as to be positionally movable with respect to the nozzle 11.

That is, the needle 12 has a cylinder 80.
The needle piston 43 is slidably fitted into the needle piston 43. The needle piston 43 is urged to the left by the return spring 42, and the needle 12 moves toward the nozzle 11
Is urged in the direction of abutting against. Also, the cylinder 80
In the left chamber of the needle piston 43, a working air hole 81 for allowing working air to flow in is formed. The working air hole 81 is connected to the working air control valve. Further, a frame 77 is formed outside the nozzle body 79, and an air ejection port 47 for ejecting air is formed between the nozzle body 79 and the frame 77. A nozzle outer hole 78 is formed at a position facing the nozzle 11 of the frame 79.

Above and below the nozzle outer hole 78, FIG.
As shown in, a pair of first air nozzles 20 are provided. A pair of corners 18 are formed outside the first air nozzle 20 in parallel with the spray direction of the paint. The nozzle outer hole 7 is provided on the side surface of the pair of corners 18 on the nozzle outer hole 78 side.
A pair of second air nozzles 19 for ejecting air from 8 to about 10 mm outward are provided. The first air nozzle 20 and the second air nozzle 19 communicate with each other through an air chamber 21 formed in the apparatus body. In addition, the air chamber 21
Is connected to the paint passage 13 by an air spray passage 29 formed on the entire circumference. Further, the air chamber 21 communicates with the air passage 22. An air joint 23 is formed on the upper side of the air passage 22, and the air passage 22 and the air joint 23 communicate with each other. The air joint 23 is connected to an air solenoid valve (not shown) that blocks the flow of compressed air.

The operation of the conventional spraying device having the above structure will be described. When spraying the paint F, the operating air control valve and the air solenoid valve are opened to flow the paint F into the paint joint 14,
The compressed air A is made to flow into the air joint 23. Also,
At this time, the needle 12 is separated from the nozzle 11 by the action of the working air. As a result, the paint ejected from the nozzle 11 is atomized by the air ejected from the air ejection port 47 and sprayed from the nozzle outer hole 78. Further, the air ejected from the second air nozzle 19 has a function of diffusing the paint ejected from the nozzle 11 in the form of mist.

[0006]

However, the glaze used as a glaze for pottery is a solution of soil dissolved in water, and when left at room temperature, the soil and water are separated from each other. When the device was used, the nozzle immediately became clogged, and there was a problem that glaze could not be sprayed. Further, there is a problem that the glaze is not uniformly applied due to clogging of the nozzle. This caused unevenness on the surface of the finished porcelain, reducing the commercial value. This has the same problem because the volatile solvent volatilizes and the solid remains when the varnish applied to the wood or the like is left as it is.

Further, in the conventional spraying device, as shown in FIG. 4, there is a problem that the atomized paint returns to the vicinity of the nozzle and adheres to the nozzle to clog the nozzle. An object of the present invention is to solve the above-mentioned problems, and an object thereof is to provide a spraying device that sprays a liquid such as glaze that is easily separated without causing clogging. Another object of the present invention is to provide a spray device for a paint, which prevents clogging of the nozzle caused by backflow of the paint sprayed from the nozzle.

[0008]

To achieve this object, a spraying device according to the present invention has a nozzle main body having a liquid passage therein and a nozzle hole formed at a tip thereof, and a liquid to the liquid passage of the nozzle main body. A spray device that has a liquid supply means for supplying and a gas supply means for supplying gas in the vicinity of the nozzle hole, and blows out the gas in the vicinity of the nozzle hole to eject the liquid in a spray form from the nozzle hole, It has a liquid recovery means for recovering the liquid from the liquid passage of the nozzle body. Further, the spraying device of the present invention has, in addition to the above configuration, a recovery liquid amount adjusting means for adjusting the amount of liquid recovered by the liquid recovery means.

Further, the spraying device of the present invention comprises a nozzle body having a nozzle hole at its tip, a liquid supply means for supplying a liquid to the nozzle hole, and a gas supply means for supplying a gas near the nozzle hole. A spraying device for ejecting a liquid in a spray form from the nozzle hole by ejecting the gas in the vicinity of the nozzle hole, and by ejecting the gas from the outside toward the nozzle hole, the liquid ejected from the nozzle hole is It has liquid backflow prevention means for preventing backflow to the nozzle hole.

[0010]

The liquid supply means of the spraying device of the present invention having the above structure supplies the liquid to be sprayed to the nozzle. Further, the gas supply means supplies the compressed gas to the nozzle. Then, the nozzle ejects the compressed gas to eject the liquid in a spray state. Further, the liquid recovery means recovers the liquid from the nozzle when the spraying is not performed. As a result, the liquid does not constantly flow and stay near the nozzle, so that it is possible to prevent the trouble that the liquid is separated and the solid substance is clogged in the nozzle even when spraying a liquid that is easy to separate, such as glaze. Further, the recovered liquid amount adjusting means adjusts the amount of liquid recovered by the liquid recovering device. Further, the liquid backflow prevention unit of the spraying device of the present invention prevents the liquid ejected from the nozzle from flowing back to the nozzle by blowing gas from the outside toward the small hole portion of the nozzle.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A spraying device 9 for applying a glaze, which is a glaze, to ceramics, which is an embodiment of the present invention, will be described below with reference to the drawings. FIG. 1 shows a plan partial cross-sectional view taken along the center line when the spraying device 9 is viewed from above, and FIG. 2 shows a side cross-sectional view cut along the center line when viewed from the side direction. . First, the passage relationship of the glaze F will be described. A hollow nozzle body 7 is provided at the center of the spraying device 9.
9 is attached. The hollow portion of the nozzle body 79 forms the glaze passage 13 for conveying the glaze. The glaze passage 13 communicates with a glaze supply port 31 for supplying the glaze and a glaze recovery port 32 for recovering the glaze. A glaze supply joint 76 is attached to the glaze supply port 31. A glaze recovery joint 75 is attached to the glaze recovery port 32.

The tube connected to the glaze supply joint 76 communicates with the discharge port of a glaze supply pump (not shown). The tube connected to the glaze recovery joint 75 is
It is connected to a glaze tank (not shown). Further, a nozzle 11 which is a fine hole for ejecting the glaze F is opened at the left end portion of the nozzle body 79. The nozzle 11 communicates with the glaze passage 13. A needle 12 having a conical tip is attached at a position facing the nozzle 11 at the center of the glaze passage 13. A frame 77 is attached to the outside of the left end of the glaze passage 13. Frame 77
A nozzle outer hole 78 is formed at a position opposed to the nozzle 11.

On the other hand, a flat plate-shaped collection amount adjusting valve 70 for adjusting the amount of glaze collected is attached to the glaze collecting port 32 slidably in the direction of opening and closing the glaze collecting port 32. That is, the piston portion 70a of the recovery adjustment valve 70
Has an elliptical shape, and is slidably fitted in the same elliptical guide hole 72. Further, the recovery adjustment valve 70 is biased in the direction of opening the glaze recovery port 32 by the recovery spring 71 that comes into contact with the piston portion 70a. Further, the recovery amount adjusting screw 73 is in contact with the piston portion 70a from the direction opposite to the recovery spring 71. A fixed nut 74 is attached to the recovery amount adjusting screw 73.

In the middle of the needle 12, a needle holding member 37 for slidably holding the needle 12 is screwed into the main body 45. The right end of the needle 12 is fixed to the needle piston 43. The needle piston 43 is slidably fitted in a hollow cylinder 80. A cylinder air hole 81 is formed in a chamber on the left side of the needle piston 43 of the cylinder 80. The cylinder air hole 81 communicates with the working air joint 82.
The tube connected to the working air joint 82 is in communication with a spray control valve for controlling the working air to drive the spray device 9. On the right side of the needle piston 43, the return spring 4
2 abuts on each other and urges the needle 12 in a direction of closing the nozzle 11. The right end of the return spring 42 has the return spring receiver 4
It is in contact with 4. A female screw is formed at the center of the return spring receiver 44, and the glaze spray amount adjusting screw 40 is attached to the female screw portion. A fixing nut 41 is attached to the glaze spray amount adjusting screw 40.

Next, the relationship of the air passages will be described. An air jet 47 for atomizing the glaze is formed between the nozzle body 79 and the frame 77. Air jet 47
Communicates with the jet air passage 38, which is a circumferentially formed space. The jet air passage 38 communicates with the first air hole 39. In the first air hole 39, the first air joint 33
Is attached. The tube connected to the first air joint 33 is connected to the first air control valve. Further, a second jet air passage 21 is formed circumferentially around the jet air passage 38. The second jet air passage 21 communicates with the second air hole 22. A second air joint 34 is attached to the second air hole 22. The tube connected to the second air joint 34 is connected to the second air control valve.

FIG. 3 shows a front view of the nozzle portion of the spraying device 9. A nozzle outer hole 78 for spraying the glaze F is formed at the center position. First air nozzles 20 are provided at two positions above and below the nozzle outer hole 78. Further, the first air nozzles 46 are also provided at the left and right portions of the nozzle outer hole 78, respectively. The six first air nozzles 20 and 46 communicate with the jet air passage 38. Corners 18 are formed at positions outside the first air nozzle 20 above and below the nozzle outer hole 78. An air chamber 21 that is a hollow portion in the corner portion 18
Are formed. The air chamber 21 communicates with the inside of the main body 45 in a circumferential shape. A backflow prevention nozzle 35 is bored from the main body of the corner portion 18. A second air nozzle 19 is formed on the tip side of the corner portion 18. The backflow prevention nozzle 35 and the second air nozzle 19 communicate with the air chamber 21.

Next, the operation of the spraying device 9 having the above-described structure will be described. The spraying device 9 of the present embodiment is attached to a robot hand or the like, and its purpose is to automatically apply the glaze uniformly to the ceramics. First, the glaze F, which is a glaze of ceramics, is placed in a glaze tank (not shown), and the glaze F is sent to the spraying device 9 by a glaze pump. Since the spray control valve is not driven, the spray device 9 is not supplied with working air. Further, neither the first air control valve nor the second air control valve is driven, and no air is ejected. Therefore, the needle piston 43 has the return spring 4
The needle 12 is urged to the left by 2 and the needle 12 is also urged to the left, and is in contact with the nozzle 11. Nozzle 11
Since the valve seat having the same inclination as that of the tip of the nozzle 11 is formed at the portion contacting the needle 12, the glaze F is not sprayed because the needle 12 and the nozzle 11 come into close contact with each other.

Although the glaze F is not sprayed, in this embodiment, since the recovery amount adjusting valve 70 opens half of the glaze recovery port 32, the glaze F supplied from the glaze supply port 31 at a constant discharge pressure. However, since the glaze F does not return to the glaze tank from the glaze recovery port 32 and stays in the glaze passage 13, the glaze F
Since the water and the soil are not separated from each other, the trouble that the soil clogs the nozzle 11 at the start of spraying can be prevented.

Next, the case where the spray control valve is driven and the working air is supplied will be described. The needle piston 43 is moved to the right by the working air, and the glaze spray amount adjusting screw 4
It abuts 0 and stops. Therefore, the needle 12 is also separated from the nozzle 11. Here, the needle 12 and the nozzle 11
It is possible to adjust the spray amount of the glaze F by adjusting the amount of separation between and by using the glaze spray amount adjusting screw 40.
When the needle 12 and the nozzle 11 are separated from each other, the nozzle 1
Glaze F is ejected from 1. Since the glaze recovery port 32 is half closed by the recovery amount adjustment valve 70, the glaze passage 13
This is because a certain pressure is applied to the glaze F inside.

On the other hand, since the first and second air control valves are driven at the same time as the spray control valve, air is jetted vigorously from the air jet port 47, and the glaze F jetted from the nozzle 11 is blown and atomized. . Further, the air ejected from the six first air nozzles 20 and 46 functions to atomize the atomized glaze F into fine particles and disperse the glaze F uniformly in a certain range. Further, the second air nozzle 19 also functions to spray the air in the traveling direction of the atomized glaze F, to atomize the glaze F and to disperse the glaze F uniformly in a certain range. The glaze F atomized and sprayed from the nozzle outer hole 78 generates convection T near the nozzle outer hole 78 and tries to return to the nozzle 11 again, as shown in FIG. However, in this embodiment, since the backflow prevention nozzle 35 ejects air near the nozzle outer hole 78 and the nozzle 11, the glaze that attempts to backflow is blown off. As a result, the nozzle 11 is caused by the glaze T flowing backward.
It prevents the trouble of clogging.

Next, when the application of the glaze F is completed, first, the drive of the spray control valve is stopped and the supply of working air is stopped. As a result, the needle piston 43 is urged by the return spring 42 to move to the left, and the needle 1
2 and the nozzle 11 come into contact with each other, and the ejection of the glaze F is stopped. After some time has passed, the driving of the first and second air control valves is stopped and the ejection of air is stopped. By ejecting air from the backflow prevention nozzle 35 for a while, the atomized glaze F can be completely removed from the vicinity of the nozzle 11, and thus the clogging of the nozzle 11 by the glaze F can be prevented.

As described in detail above, according to the spraying apparatus of the present invention, the glaze collecting port 32 for collecting the glaze F from the nozzle is provided, so that the glaze can be sprayed even when the spraying is not performed. Since the glaze F in the passage 13 is not retained, the glaze F does not separate into water and soil, and the separated soil does not clog the nozzle 11. Further, according to the spraying device of the present invention, since the backflow prevention nozzle 35 blows the gas from the outside toward the nozzle 11, it is possible to prevent the glaze F ejected from the nozzle 11 from flowing back to the nozzle 11. The backflow glaze F does not adhere to the vicinity of the nozzle 11 and clog the nozzle 11.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the technical idea of the present invention. For example, in the present embodiment, the glaze collecting port 32 for collecting the glaze F is provided with the collection adjusting valve 70 so that the glaze F is ejected from the nozzle 11 when spraying, but the collection adjusting valve 70 is provided. Instead, a recovery control valve is attached, and when spraying, the recovery control valve is closed and the glaze F is ejected from the nozzle 11. When not spraying, the recovery control valve is opened to create a flow of the glaze F. May prevent the glaze F from staying. Further, the recovery adjustment valve 70 and the recovery control valve may be used together. Alternatively, a proportional valve may be used as the recovery control valve so that the recovery control valve has the function of the recovery adjustment valve 70.

Further, in this embodiment, the second air nozzle 19
The backflow prevention nozzle 3 at the same corner 18 where the
No. 5 was drilled, but no matter what kind of nozzle
If a nozzle is installed so that air can be blown directly onto the
The object of the present invention can be achieved. Further, in this embodiment,
Although the spraying device for the glaze F has been described, the backflow preventing nozzle can also be used in a spraying device for general paint to obtain the same effect.

[0025]

According to the spraying device of the present invention, since it has the glaze recovery route for recovering the glaze from the nozzle,
Even when spraying is not performed, the glaze is not kept in a constantly flowing state and is not retained, so that the glaze does not separate into water and soil, and the separated soil does not clog the nozzle. Therefore, it is possible to prevent troubles such as coating unevenness due to nozzle clogging.

Further, according to the spraying device of the present invention, since the backflow preventing nozzle blows the gas from the outside toward the nozzle, it is possible to prevent the liquid ejected from the nozzle from flowing back to the nozzle, so that the backflow occurs. The liquid does not adhere to the vicinity of the nozzle and clog the nozzle. Therefore, it is possible to prevent troubles such as coating unevenness due to nozzle clogging.

[Brief description of drawings]

FIG. 1 is a plan partial cross-sectional view of a spraying device that is an embodiment of the present invention.

FIG. 2 is a side sectional view of a spraying device.

FIG. 3 is a front view of a main part of the spraying device.

FIG. 4 is a side sectional view in the vicinity of a nozzle hole of the spraying device.

FIG. 5 is a side sectional view of a conventional spraying device.

[Explanation of symbols]

 9 Spraying device 11 Nozzle hole 12 Needle 13 Glaze passage 20 First air nozzle 32 Glaze collection port 35 Backflow prevention nozzle 38 Jet air passage 43 Air jet outlet 70 Recovery adjustment valve 73 Recovery amount adjusting screw 77 Frame 78 Nozzle outer hole 79 Nozzle body

Claims (3)

[Claims] 1. A nozzle body having a nozzle hole at its tip and having a liquid passage therein, a liquid supply means for supplying liquid to the liquid passage of the nozzle body, and a gas supply means for supplying gas in the vicinity of the nozzle hole. And a spraying device for spraying a gas in the vicinity of the nozzle hole to spray the liquid in a spray form from the nozzle hole, wherein the spraying device has a liquid recovery means for recovering the liquid from the liquid passage of the nozzle body. Spraying device. 2. The spraying device according to claim 1, further comprising a recovered liquid amount adjusting means for adjusting the amount of liquid recovered by the liquid recovering device. 3. A nozzle is provided with a nozzle main body having a nozzle hole at its tip, a liquid supply means for supplying a liquid to the nozzle hole, and a gas supply means for supplying a gas near the nozzle hole. In a spray device that sprays liquid in a spray form from a nozzle hole by spraying in the vicinity of the hole, by spraying gas from the outside toward the nozzle hole, the liquid sprayed from the nozzle hole flows back to the nozzle hole. A spraying device comprising liquid backflow prevention means for preventing such a phenomenon.