JPH0724799B2 - Liquid spraying method and apparatus - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid spraying method and an apparatus therefor capable of coping with a coating having a return at an inlet portion in a deep groove or an inner surface of a tank.

<Prior art> Conventionally, there is a one-sided gun for spraying paint diagonally forward with air spray, but this is only one direction of spray, and the return part of the object to be coated with deep grooves is painted. No (for example, Japanese Utility Model Publication No. 35-678). That is, the one-sided gun forms an air port for atomization around the tip of the elongated paint nozzle,
High-pressure air is sprayed and atomized on the sprayed paint, and another high-pressure air stream is sprayed and collided from the side to form a spray flow diagonally forward, which is mainly used for coating the inner surface of pipes. . In this case, the injection direction is at least lateral
A spray flow of more than 90 ° and heading forward. That is, the opening of the paint is directed to the front, and if it is made to have a component directed to the rear by the external air flow, the sprayed paint adheres to the nozzle opening surface and stains it, and the adhered paint scatters on the coated surface. To stain.

In addition, there is a so-called long neck gun in which the tip is bent as an air spray gun and is sprayed laterally or obliquely forward and backward, but since the air passage is formed in addition to the paint passage, the structure is complicated and the tip nozzle The shape of the part also becomes large. Other than the air spray, there is already a spray gun that has a bended structure at the tip of the pipe as an airless spray and can freely change the injection angle.

Although various devices are used for the inner surface coating depending on the shape of the object to be coated, generally, the coating on the back surface is rarely performed by spray coating. This is because the overspray mist caused by spraying came to the operator side and there was no suitable coating device. Normally, in the case of an object to be coated whose groove is wide at the back, it is painted by a method such as dipping in factory painting, but these coatings are not suitable for small amount painting, and repainting or repair after installation is not suitable. It is possible. However, the conditions such as corrosion and rusting are rather worse on the inner surface, and there is a need for reliable coating. Most of the C-shaped steel with a return at the inlet has an inner surface size of about 50 to 100 mm, which cannot be coated with a conventional spline gun.

As mentioned above, with the air spray gun, the atomizing head does not enter the groove, and even if a small structure that can enter can be manufactured in return, the spray port itself will be small and the required amount of paint spray cannot be obtained. Also, if the paint has a high viscosity, it cannot be jetted.

Further, since the high-pressure paint is sprayed in the airless spray gun, the spray amount is too large, which causes a problem such as dripping of the paint. In order to reduce the dripping of the paint, an extremely small nozzle opening is used, and even a sufficiently filtered paint becomes clogged and unusable.

Compressed air is added to the liquid ejected from the nozzle to atomize,
Compressed air and liquid (paint) using an air spray gun
Is pressure-fed to the mixing chamber in the main body of the spray gun, and the gas mixture mixed and atomized in the mixing chamber is sprayed from the opening nozzle at the tip through the transfer pipe. It is possible to spray on the object, and by giving the degree of freedom in the spray direction of the opening nozzle, it can be applied to objects such as those with a return at the inlet part that could not be coated with conventional spray guns. It is an object of the present invention to provide a liquid spraying method and an apparatus therefor which can also be applied.

<Means for Solving the Problems> The present invention is an air spray gun for spraying liquid from a nozzle by adding compressed air to atomize and spray the compressed air and liquid from a paint pressure tank at the same pressure. The mixture was pressure-fed to the mixing chamber formed at the tip of the spray gun body through the separately arranged passages to mix the compressed air and the paint to form a mixture gas, and the mixture gas was connected to the outlet of the mixing chamber. The spray is provided with a degree of freedom in the spray direction from an opening nozzle attached to the tip via a transfer pipe.

Further, the apparatus using the above method is provided, which is provided with a mixing and atomizing means for mixing and atomizing a liquid and a gas placed in the spray gun body, a transfer pipe for transferring the mixed gas-liquid, and a tip of the transfer pipe. An opening nozzle for ejecting the mixed gas / liquid to the outside and a means for changing the spray direction of the opening nozzle are provided.

<Operation> Using the liquid spraying device having the above-mentioned configuration, the compressed air is previously sent into the paint pressure feed tank, the compressed air and the paint are sent from the pressure feed tank to the spray gun main body at the same pressure, and the tip of the spray gun main body is supplied. In the mixing chamber formed in the above, the mixture is atomized and is guided to the opening nozzle through the transfer pipe extending to the tip and is ejected from the opening nozzle to the outside. Can be sprayed. Moreover, by interposing an elbow that bends in the injection direction at the tip of the transfer pipe, it is possible to impart a return direction component to the injection, and it is possible to coat the inner surface of objects of various shapes. Of course, this opening nozzle can be arbitrarily selected by providing a plurality of nozzles having different ejection directions.

<Example> The following will describe the present invention with reference to the accompanying drawings.

Reference numeral 1 is a spray gun main body, and a needle valve 3 which slides with a trigger 2 in the center is made to advance and retreat toward a paint nozzle 6 at the end of a paint passage 5 connected to a paint hose 4, and the paint nozzle 6
Is provided with a mixing chamber 9 facing the end of an air passage 8 whose base end communicates with the air hose 7 in front of the nozzle opening of the above, and constitutes a mixing and atomizing means of paint and air, and the front end of the mixing chamber 9 A transfer pipe 10 for transferring the gas mixture is connected to the transfer pipe.
Attach an opening nozzle 12 with a throttle opening 11 at the tip of 10,
In addition, the base end of the paint hose 4 is guided to the paint pressure tank 14, the base end of the air hose 7 is guided to the upper space a of the paint pressure tank 14, and the air source is supplied to the upper space a via the pressure reducing valve 15. 16 is connected so that compressed air and paint are introduced into the mixing chamber 9 of the spray gun body 1 from the paint pressure tank at the same pressure, and the liquid spraying device 17 is configured as a whole. In this case, a metal pipe or the like is used as the transfer pipe 10, but when the nozzle portion is made small and simple, a flexible pipe, for example, a flexible pipe capable of maintaining a bent shape is used. In addition, the opening nozzle 12 at the tip of the transfer pipe 10 may be configured such that the injection direction is the return direction component via the elbow 18 (see FIG. 3), or as shown in FIGS. A plurality of nozzles 13 each having a plurality of opening nozzles 12 arranged in the radial direction are attached to each of the nozzles so that each nozzle has a different jetting direction, so that the spraying direction can have a certain degree of freedom.
Reference numeral 19 is a nozzle-selective shot. By rotating the shot 19, the integral valve body 20 is rotated to form a cutout portion 21 formed in the valve body 20.
The nozzles 12 having the required jetting directions can be selected by matching the nozzles with the jetting nozzles 12 having the jetting directions. In the figure, 27 is a spring washer and 28 is blind.

FIG. 5 shows still another embodiment, in which the transfer pipe is
Insert the rotary nozzle mechanism 22 at the tip of the
The rotary nozzle mechanism 2 is provided with a rotary nozzle main body 22 having a rotary guide 23 'connected to a rotary shaft 23 as a center.
A rotary nozzle 24 is attached to a and the opening nozzle 1
2 is installed. 25 is a flow passage for the mixed air flow A ',
A flow passage 26 formed in the rotary nozzle 24 from the transfer pipe 10.
The mixed gas and liquid is supplied to the opening nozzle 12 via the.

Next, the operation will be described. The compressed air B is sent to the position of the upper space a of the paint A filled in the paint pressure tank 14, and the compressed air and the paint are applied from the paint pressure tank 14 to the spray gun body 1 at the same pressure. The needle valve 3 is retracted by feeding and pulling the trigger 2, and the paint A is fed from the nozzle opening of the paint nozzle 6 into the mixing chamber 9
And the compressed air from the air passage 8 to the mixing chamber 9
Is introduced into the mixing chamber 9 and the mixed gas 9 of the paint and compressed air
Is formed, and the mixed gas liquid A'is sent to the opening nozzle 12 at the tip through the transfer pipe 10 and sprayed from the throttle opening 11 at the tip to spray the paint.

Further, since the injection direction has a return direction component due to the interposition of the elbow 18, it is most suitable for coating the inner front wall of the article C to be coated.

Furthermore, in the case of using the plurality of nozzles 13 having the opening nozzles 12 in a plurality of jetting directions and having the degree of freedom in the spraying direction of the embodiment shown in FIGS. The mixed gas liquid A ′ is turned around the nozzle selective photographing 19, the valve body 20 integrated with this is turned, and the notches 21 are aligned with the plural opening nozzles 12 arranged in the radial direction. Make it jet. If necessary, all of the opening nozzles 12 can be ejected at the same time, or some of them can be ejected and only the required ejection can be selected.

Further, as in the embodiment shown in FIG. 5, the transfer pipe 10 and the opening nozzle 12 may not be directly connected, but the rotary nozzle mechanism 22 may be interposed. That is, a rotating means (not shown) separately arranged
The rotary nozzle main body 22a having a rotary guide 23 'connecting the rotary shaft 23 is provided with a swing type rotary nozzle portion 24, and the opening nozzle 12 is attached to the tip of the rotary nozzle portion 24. In this case, the gas-liquid mixture A ′ flowing out from the transfer pipe 10 is injected from the flow passage 25 of the rotary nozzle body 22a to the open nozzle 12 through the flow passage 26 of the rotary nozzle 24. This embodiment is of a type in which the direction of sprayed paint by swinging is variable.

The spray amount is adjusted by the paint nozzle 6 at the tip of the gun body 1.
It is needless to say that the adjustment can be made by selecting (1) or rotating the paint adjusting photograph 29 at the rear end of the gun body 1.

<Effects of the Invention> As described above, the liquid spraying method and apparatus of the present invention are
Since the compressed air and the paint are mixed in advance in the mixing chamber inside the gun body and guided to the opening nozzle at the tip through the transfer pipe connected to the gun body, the opening nozzle itself can be miniaturized. , It can be carried into a fine area of the article to be coated. It is also possible for the transfer pipe to be made of a flexible material and to change direction itself. In addition, in the experiment conducted by the inventor, this mixed gas-liquid was transferred to a 70 mm
It has been found that even after the above transfer, there is no shortness of breath that may hinder painting. Further, if the amount of paint to be sprayed is adjusted to be small, atomization is also improved, whereby the tip of the opening nozzle can be minimized and the spray direction can be freely set. Further, if the elbow is provided in front of the opening nozzle, the injection direction can be made to be the return direction. For example, the lip upper surface in the C-shaped steel, the barbed portion in the deep groove, the tank inner surface, etc. can be easily coated, and the transfer can be performed. By providing a swing-type rotary nozzle with a rotary nozzle mechanism interposed at the tip of the pipe, it is possible to provide a degree of freedom in the injection direction. Further, by arranging a plurality of opening nozzles in a radial pattern and making a notch portion of the valve body communicate with any one of the opening nozzles by performing nozzle selective shooting, spraying with different injection directions is also possible. . Moreover, since it is sprayed from the nozzle as an air mixed flow, the injection amount can be adjusted from a minute amount to a large amount, and the pattern can be selected from flat spraying to round spraying by exchanging the nozzle. Therefore, the nozzle provided at the tip can be applied depending on the spraying material and the object, and it can be dealt with by providing various nozzles.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is an explanatory view showing a main part, FIG. 2 is a sectional view of a mixing chamber part of a gun body, and FIG.
The figure is a cross-sectional view of an opening nozzle portion using an elbow, FIG. 4A is a vertical cross-sectional view of a multi-opening nozzle, and FIG. 4B is II-II of FIG. 4A.
FIG. 5 is a cross-sectional view taken along line II-III, and FIG. 5 is a cross-sectional view of an opening nozzle provided with a rotary nozzle mechanism. 1 ... Gun body, 4 ... Paint hose 5 ... Paint passage, 7 ... Air hose 8 ... Air passage, 9 ... Mixing chamber 10 ... Transfer pipe, 12 ... Opening nozzle 12 '... Multiple nozzles , 12 …… Reversing nozzle 14 …… Paint pressure tank, 18 …… Elbow 22 …… Rotating nozzle mechanism, 24 …… Rotating nozzle

Claims (4)

[Claims] 1. An air spray gun for spraying a liquid sprayed from a nozzle with compressed air by atomizing and spraying the compressed liquid and the liquid at the same pressure from a paint pressurizing tank via separate passages. It is sent under pressure to the mixing chamber formed at the tip of the spray gun body, and the compressed air and liquid are mixed to form a gas-liquid mixture,
A method for spraying a liquid, characterized in that the gas mixture is sprayed through a transfer pipe connected to the outlet of the mixing chamber, with an opening nozzle attached to the tip end, with a degree of freedom in the spray direction. 2. An air blowing gun for adding compressed air to a liquid jetted from a nozzle to atomize and spray the liquid, and the compressed air and the liquid are separately provided at the same pressure from a paint pressure tank via passages. Mixing and atomizing means for feeding under pressure to a mixing chamber formed at the tip of the spray gun main body to mix and atomize liquid and compressed air, and a transfer pipe for transferring the mixed and atomized mixed gas-liquid,
A liquid spraying device comprising: an opening nozzle provided at the tip of the transfer pipe for injecting the gas-liquid mixture to the outside; and means for varying the spraying direction of the opening nozzle. 3. The fluid spraying device according to claim 2, wherein the opening nozzle is attached to the tip of the transfer pipe via an elbow so that the injection direction has a return direction component. 4. The opening nozzle has a plurality of nozzles each having a different injection direction, and a notch formed in a valve body that is movable by nozzle selective shooting faces the entrance of the nozzle, and the opening nozzle having a necessary injection direction is formed. 3. The liquid spray device of claim 2 which is selectively mounted.