JP4652094B2 - Pattern variable single-angle spray gun - Google Patents

Description

The present invention relates to an air spray gun that atomizes paint or the like with compressed air and performs spray coating toward an object to be coated, and particularly relates to an air spray gun used when painting a small-diameter inner surface. is there.

An air spray gun for atomizing a paint using compressed air to form a painted surface is widely used in various fields because it can deal with the uniformity of the finished surface, a wide range of objects to be coated, and the paint. When painting the inner surface of a small-diameter pipe-shaped object, a spray gun is known in which a spray gun atomizer is inserted into the inner surface of a rotated object to be coated and deflected and sprayed in one direction on the inner surface. Yes. (Act No. 35-678)

Many of these require that the object to be rotated, and because the precise spray gun movement is required in relation to painting the thin pipe-shaped inner surface, the operation is often controlled by automatic machines. The use as an automatic spray gun is common. Therefore, in most cases, a spray gun having a specification capable of spraying suitable for an object to be coated is installed and mass-produced in most cases, so-called dedicated, and there is little need for adjustment.

A spray gun having a configuration in which a separate change air nozzle is installed as proposed in Japanese Utility Model Publication No. 62-27241 has been proposed as an idea to enable adjustment of the spray. A nozzle for changing the direction is provided, and the nozzle is connected by a supply pipe and sprayed. Therefore, since it is necessary to provide an injection device provided separately from the atomizing device, the complexity and size of the structure cannot be avoided.

In addition, it is considered as one of the advantages that a stable coating can be maintained without making troublesome adjustments by designing with specifications according to the painted surface and using it exclusively for changing the object to be coated. It was. However, in recent years, diversification of objects to be coated has increased the tendency to change to a variety of small-volume production and parallel production of various types, and accordingly, the necessity to change the coating conditions during painting is increasing.

In addition, the automation of painting is progressing in the functionality of coating machines, and the improvement of the function of the spray gun itself has been demanded. The use of a highly versatile painting robot for automatic painting results in waste that cannot be fully utilized by a general-purpose spray gun with fixed operation functions despite excellent operational control.

In the conventional single-angle spray gun, a paint nozzle is disposed at the tip of a pipe in which a paint passage is formed at the center, and an air pipe provided with a cap at the tip that forms an annular air port so as to surround the tip of the nozzle, The air passage is formed by doubling the outside of the paint pipe. A square air hole (also called side air) that deflects the pattern is opened toward the axis of the diagonally forward spray, and is changed in such a way that it is blown laterally with respect to the spray flow of the paint sprayed from the center. It is structured to be applied to the inner surface.

Since the airflow is blown by air with the same angle as the center, it is limited to blowing in the same state, and if the object to be coated and the coating conditions change, it is necessary to prepare an atomizer unit according to the conditions . In other words, up to now, the inner surface of the relatively simple shape has been the main, but the need for small and precise inner surface coating, such as digital cameras, has increased, and the demand of the market is high in production efficiency. There is an increasing demand for spray guns that can handle a wide range of paintings.

In particular, when painting an inner surface with a small diameter, as described above, the spray gun cannot be tilted only by advancing and retracting the tip of the spray device. Therefore, if the same thing is simply mass-produced on the pipe-shaped inner surface, there will be no major problems, but if there is a change in the inner diameter or a groove, uniform coating is not possible only with the same angle, and the direction of spraying is not possible. It needs to be changed arbitrarily.

As shown in FIG. 5, while the movement of the spray gun is restricted for an object whose inner surface is not constant, it is possible to achieve a more uniform coating finish by changing the direction of spraying. If the size is smaller, the angle can be reduced to increase the distance to the paint surface, and if there is a groove, the angle can be increased to better enter the interior.
Jikosho 35-678 Jikosho62-27241

As described above, the conventional one-sided gun has a fixed pattern bending angle, so that it cannot respond to changes in the inner diameter of the object to be coated, and has to be specially designed and manufactured. In addition, it enables spray guns that can adjust the bending angle of sprays as needed in response to the diversification of objects to be coated, and can be applied by adjusting spray guns without preparing many spray guns. It is an object of the present invention to improve productivity. In addition, spraying with a large bending angle, which was not possible before, is possible, and even if there are uneven cross-sections and diameter differences on the inner surface of the small diameter, a uniform coated surface is possible, and these adjustments are at the hand of the spray gun This makes it easy to do so without burdening the operator.

A spray gun with an annular central air port around the nozzle port and a side air port from one direction facing the spray axis outside the central air port. Air is supplied, and a flow rate adjusting means capable of adjusting the supply amount is provided for the side air. Normally, the regulating valve for restricting the passage is used as the flow rate adjusting means, but the same thing can be said if the supply is made by using the means for adjusting the supply pressure. The spray flow of the paint sprayed from the center is sprayed obliquely forward by the spray axis being bent by the air ejected from the side air port from one direction. At this time, if the amount of side air ejection is changed by the adjusting valve, the bent angle changes, and the coating condition on the inner surface can be adjusted.

The supply passages to the center air port and the side air ports are separated by the gun body, and concentric double pipes extending forward are also concentrically arranged outside the paint passage at the center, and each pipe from each air passage of the mounting base. Independent air is supplied through the double passage between them. Each air is injected as the central air and side air of the atomizer unit.
The supply air to the central air port and the side air port is configured to be supplied to the gun body from a separately controlled air circuit, and the control range of the spray pattern can be expanded by supplying independent control air. .

As described above, according to the present invention, the paint particles atomized by the central air from the nozzle tip are blown laterally by the side air injection from the central axis direction and sprayed laterally with respect to the shaft. The pattern direction at this time is changed by adjusting the jetting force of the side air. If the side air is completely shut off, the pattern is jetted forward and gradually increased to increase the lateral bending angle. Therefore, the required angle can be selected according to the inner diameter of the object to be coated, and the application can be applied with the optimum directionality, so the application is widened, and work such as changing the spray gun depending on the surface to be painted or for each object to be painted becomes unnecessary. Reasonable painting is possible. In addition, it is not necessary to prepare spray guns with many specifications, leading to reductions in equipment and maintenance costs.

In addition, since the air passage is made of a double pipe, it can be made with a minimum thickness without greatly changing from the conventional one, so that it can cope with an object to be coated having a small-diameter inner surface.

In addition, if a side air adjustment valve is provided on the gun body, the bending angle adjustment at hand can be easily set, and by supplying air with controlled pressure through a separate control circuit to the side air, a higher pressure than the center air is achieved. Therefore, the adjustment range is further expanded, and spraying in a substantially perpendicular direction is also possible. Therefore, it can be applied to a coating with a relatively large inner diameter, and can be applied to the groove provided on the inner surface, like a lens barrel having a groove on the inner surface of a small diameter, which has been impossible in the past. High-quality finish is now possible as a spray-coating of a simple object.

FIG. 1 shows the overall structure of a single-angle spray gun according to an embodiment of the present invention. FIG. 2 shows a detailed cross section of the atomizing device at the tip. The spray gun is an example of an automatic gun, and an atomizing device section 3 is attached to the tip of a main body 1 at the tip of a neck 2 extending in a pipe shape. The compressed air for atomization opens the air valve 5 by the operation of the piston 4 and is sent from the air passage 6 through the passage 13 to the atomizing device section 3 at the tip. Since the structure for operating this type of automatic spray gun is well known and does not limit the present invention, a detailed description thereof will be omitted.

Paint and air are supplied to the atomizing device from the spray gun main body side, and as shown in detail in FIG. 3, a nozzle base 12 for attaching a paint pipe 21 is screwed to the main body 1, and the inside is a paint supply port. 11 is communicated. The atomizing air is separated from the rear part of the gun through the passage 13 into the central air chamber 14 and the angular air chamber 15 and connected to the central passage 17 and the angular passage 18 of the front air pipe mount 16. The flow rate of air to the angular air chamber 15 is controlled by the control valve 8. The cover 19 is for detachably attaching the air pipe mount 16 to the main body, and also has a function of preventing leakage of the angular passage 18. In the description of the present embodiment, the side air is also referred to as “angular air” including the following.

The atomizer 3 has a paint nozzle 31 at the center and an air nozzle 32 concentrically disposed outside the atomizer unit 3, an outer diameter portion 34 of a jet port 33 provided at the center of the paint nozzle, and a center port 35 of the air nozzle 32 An annular air port is formed between the two. An air cap 36 is disposed outside the air nozzle 32, and the air cap 36 has a corner portion 37 protruding from one side with respect to the center port 35, and a corner air port 38 is formed slightly forward of the corner portion 37. It opens toward the central axis. A needle valve 39 is arranged inside the paint nozzle 31.

The paint ejected from the ejection port 33 is atomized by the air ejected from the center port 35 and sprayed forward. At this time, the spraying direction described above is bent by the air jetted from the angular air port 38 and sprayed in an oblique direction. As for the spray direction, the bending angle increases as the injection from the angular air port 38 becomes stronger. Normally, this bend angle is up to about 30 °, and differs depending on the balance of the sizes of the central port 35 and the angular air port 38, and the bend becomes smaller as the center jet becomes stronger.

The paint passage connection between the atomizer unit and the main body is formed by fixing the paint nozzle 31 to the tip of the paint pipe 21. The central passage 17 is connected to the air nozzle 32 so as to communicate with the central port 35 through the middle pipe 22, and the angular passage 18 is connected to the air cap 36 so as to communicate with the angular air port 38 through the outer pipe 23. ing.

Of the central air chamber 14 and the angular air chamber 15 separated on the main body 1 side, the inflow into the angular air chamber is regulated by the regulating valve 8 and passes between the outer pipe 23 and the middle pipe 22 from the angular passage 18, The air is injected from the angular air port 38 of the air cap 36. Therefore, the ratio of angular air from the side is adjusted to the spray flow of paint sprayed from the center, and the degree of spray deflection can be changed according to the painted surface of the object to be coated, without changing the spray gun Can handle a wide range of coating conditions. In addition, the independent air passage to the atomizer unit is composed of double air pipes, minimizing the increase in outer diameter and reducing the diameter that is important for inner surface coating. A spray gun having a required length for an object to be coated can be easily obtained simply by changing.

Although FIG. 6 shows another spray gun, the basic structure is the same as that of the spray gun described above, and instead of the angle air adjusting valve 8, it is introduced directly into the angle air chamber 15 from the rear pattern adjusting port 26. A connecting pipe 27 is provided. Therefore, the air sent from the air valve 5 through the air passage 6 is sent only to the central air passage chamber and is injected from the central port 35 of the atomizer.

That is, the central air and the angular air can be supplied with compressed air adjusted by separate supply circuits to control the spray state. For example, the spray direction can be deflected with a stronger jet than the central spray. In this case, it is possible to bend the direction of spraying in a substantially right angle direction, and the ability is remarkably improved, for example, coating is possible even when there are irregularities such as grooves on the inner surface. Also, by combining with automatic painting control means such as a painting robot, it is possible to coat even objects to which the coating conditions on the inner surface change without changing the spray gun, shortening the painting process and improving work efficiency. Productivity can be increased by improving the above.

It is sectional drawing which shows the whole structure of the single angle spray gun which shows one Example of this invention. It is sectional drawing to which the atomization apparatus part of FIG. 1 was expanded. It is sectional drawing to which the gun main body air passage isolation | separation part of FIG. 1 was expanded. FIG. 3 is a front view of FIG. 2. It is explanatory drawing which shows the coating state of an inner surface. It is sectional drawing of the whole structure of the spray gun which shows the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gun body 2 Neck part 3 Atomization apparatus part 4 Piston 5 Air valve 6 Air passage 8 Control valve 11 Paint supply port 12 Nozzle base 13 Passage 14 Central air chamber 15 Corner air chamber 16 Pipe mount 17 Central passage 18 Corner passage 19 Cover 21 Paint pipe 22 Medium pipe 23 Outer pipe 26 Pattern adjustment port 31 Paint nozzle 32 Air nozzle 33 Spout 34 Outer diameter portion 35 Center port 36 Air cap 37 Corner portion 38 Angle air port 39 Needle valve

Claims (2)

A paint passage and an air passage are formed by concentric pipes, and an annular central air port formed around the nozzle port at the tip, and a side air port from one direction directed to the spray axis outside the central air port In the spray gun provided with the atomizing device , the supply passage to the central air port and the side air port is separated by the spray gun main body, and a concentric double pipe is extended forward outside the paint passage in the central portion. Independent air is supplied from the air passages of the mounting base to the central air port and the side air ports through the double passages between the pipes, and the flow rate or pressure is adjusted in the passages connected to the side air ports. Pattern variable single-angle spray gun with a valve. The pattern variable single-angle spray gun according to claim 1, wherein the supply air to the central air port and the side air port is provided with an independent passage and a supply port, respectively, supplied from air circuits controlled separately.

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