JPS6212428Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a gas-liquid pressurized supply type in which the paint itself is pressurized and atomized, and at the same time pressurized air is supplied from near the base of the spray to promote atomization. This invention relates to a spray gun for painting.

Painting spray guns that have been widely used in the past include air spray guns that atomize paint using pressurized air, and airless spray guns that spray only paint under pressure and atomize it. The former, that is, air spray guns, has the advantage of being easy to adjust the discharge rate and spray pattern, and is suitable for multiple coatings, so it is easy to work with, and it is extremely safe because the paint pumping speed is slow. It is said that it is unsuitable for spraying high viscosity paints, so it uses a large amount of solvent, which goes against resource conservation, and that it is unsuitable for thick film coatings because the amount of discharge is relatively small, resulting in low work efficiency and poor paint adhesion efficiency. There are drawbacks. In addition, the latter type of airless spray gun has good work efficiency as it can handle a large discharge amount and form a large spray pattern, and is also suitable for spraying relatively high viscosity paints, so it requires less solvent. Although it has the advantage of saving money, it is difficult to adjust the discharge amount, adjust the spray pattern, and apply ^multiple coats, making it less workable than an air spray gun. The disadvantage is that it is highly dangerous because it may cause pressure. In the future, spray guns will have higher viscosity because the amount of solvent used will be reduced to reduce the amount of solvent used and the paint will have a higher viscosity in order to save resources and prevent pollution. There is a demand for a painting spray gun that is suitable for large-discharge spraying of viscous paint, achieves high adhesion efficiency, and has good workability.Therefore, we have developed a painting spray gun that utilizes the strengths of both spray guns and compensates for their shortcomings. Gun is requested.

As a paint spray gun designed to meet the above requirements, the paint itself can be sprayed under pressure of several tens of kg/ ^cm2 , which is significantly lower than that of conventional airless systems, while at the same time spraying several kilograms from the vicinity of the base of the spray. A gas-liquid pressurized spray gun that supplies pressurized air of /cm ² to promote atomization has been developed and is being put into practical use.

The present invention relates to an improvement of the above-mentioned gas-liquid pressurized supply type painting spray gun, and its purpose is to have a simple structure, small size, and excellent atomization and pattern formation. The object of the present invention is to provide a spray gun of this kind.

Another object is to provide a spray gun of this type that is convenient to assemble and disassemble and easy to maintain.

However, according to the present invention, there is provided a gas-liquid pressurized spray gun which pressurizes the paint itself and atomizes it while at the same time supplying pressurized air from near the base of the spray to promote atomization. A paint flow path 10, a valve seat 11, and a pressurized air flow path 12 are located near the tip of the gun body 1 in which a paint flow path and a pressurized air flow path are provided.
A valve seat member 13 provided with a valve seat member 13 is screwed or fitted, and a valve 14 that can be moved forward and backward in a timely manner is provided opposite to the valve seat 11.
A cap-shaped holder member 16 having an air passage 15 in the front part is connected to the cap-shaped holder member 16 having an air outlet 9 from the outside so that the air passage 15 communicates with the passage 12 in the valve seat member 13. The paint nozzle 7 is fixed to the gun body 1 with the nozzle member 17 covered and has a paint spout 18 at the tip of the holder member 16, and the paint nozzle 7 is inserted into the spout 9. In addition to providing an annular gap to form an annular gap, a spiral spring 20 is connected to a paint swirling core 19 from behind the paint nozzle 7 in the central inner cavity of the holder member 16 behind the paint nozzle 7.
They are removably installed opposite each other under pressure contact.
Furthermore, a spray gun for painting is provided in which the filter 21 is disposed while being fitted into a filter receiver 22 having a flow path communicating with the valve seat 11 by utilizing the internal gap of the spring 20.

Hereinafter, the present invention will be explained in detail based on the embodiments illustrated in the accompanying drawings.

FIG. 1 is a side view showing an embodiment of a hand-held spray gun for electrostatic coating according to the present invention, showing a proximal handle adapted to be grasped and a cylindrical main portion extending forward from the tip thereof. A pressurized air introduction pipe 2 and a conductive wire 3 for high voltage charging are connected to the handle of the gun body 1, and a paint introduction pipe 4 is connected to the front end portion of the cylindrical main part. Note that the paint introduction tube 4 may be connected to the handle of the main body 1 similarly to the pressurized air introduction tube 2 and the conductive wire 3. A valve rod 5 is disposed at the axial center of the cylindrical main portion, and is moved back and forth at the appropriate time by a trigger 6 to control the spraying of the pressurized paint supplied from the paint introduction pipe 4 from the paint nozzle 7. do.
An air on/off adjustment valve 8 is provided at the rear end of the main body 1 to vary the amount of pressurized air supplied from the air introduction pipe 2 as necessary. The amount of air jetted out from the air jetting port 9 is adjusted.

FIG. 2 is a longitudinal sectional side view of the tip of an electrostatic coating spray gun showing the main parts of the present invention, showing the cylindrical main part of the gun body 1 in which a paint passage and a pressurized air passage are provided. A valve seat member 13 having a valve seat 11 fitted to the front end of the paint flow path 10 and a pressurized air flow path 12 is fixed to the front part, and the valve rod 5 is attached to the valve seat 11.
At the front end of the valve seat member 13, a cap-shaped holder member 16 with an air passage 15 is placed so as to face the tip valve 14 of the valve seat member 13.
With the air nozzle member 17 having the air outlet 9 placed over the holder member 16, the air nozzle member 17 is tightened to the front end of the gun body 1 so that the air nozzle member 17 with the air outlet 9 communicates with the flow path 12 in the valve seat member 13. A paint nozzle 7 having a relatively small diameter paint spout 18 is press-fitted into the tip of the holder member 16, and an annular gap is formed between the air nozzle member 17 and the air spout 9. At the same time, a paint swirling core 19 is formed in the central inner cavity of the holder member 16 behind the paint nozzle 7.
The filter 21 is attached and detached from the rear of the valve seat 11 while being pressed against the valve seat 11 by a helical spring 20.
The filter receiver 22 is disposed while being fitted into the filter receiver 22, which has a flow path communicating with the filter receiver 22.

It would be better if the valve seat member 13 is provided with an annular groove 23 that communicates with the pressurized air flow path 12 and the air flow path 15 so that the valve seat member 13 and the cap-shaped holder member 1
Regardless of the relative positional relationship of 6, pressurized air flow path 1
This is advantageous in ensuring reliable communication between 2 and the air flow path 15. Furthermore, in order to seal against paint leakage between the valve seat member 13 and the cap-shaped holder member 16, a packing receiving portion 24 is formed between the two members 13 and 16, and an annular packing 25 is fitted into the packing receiving portion 24. It can be easily done. Further, the outer periphery of the cap-shaped holder member 16 is a conical tapered surface 26, and the air nozzle member 1
The leakage of pressurized air from the air flow path 15 is reliably sealed in cooperation with the engaging tapered surface 27 of the inner cavity of the cap 7, and both the members 16 and 17 are fitted into the cap retainer 28 without being displaced. It is firmly fixed to the spray gun main body 1. The valve seat 11, the valve 14, and the nozzle 7 are usually made of cemented carbide. The tip of the nozzle 7 has a tapered conical shape,
In addition, it is preferable to make the outer circumferential surface of the air outlet 9 into a similar conical shape and eject the atomization promoting air in a tapered manner from the annular gap in order to perform fine atomization and obtain a good spray pattern. The jets may be ejected in parallel if desired. The structure of the core 19 is as shown in detail in FIGS. 2 and 3.
It is preferable to have a conical surface 30 that matches the conical receiving surface 29 of the paint nozzle 7 and a plurality of paint flow channels 31, 31 carved diagonally and radially on the conical surface 30.

As the filter receiver 22, the valve seat 1
1 and a plurality of slit channels 33 branching laterally from the center channel 32 and a plurality of slit channels 33 branching laterally from the center channel 32 and fitting the filter 21 on the outer circumferential side thereof,
It is preferable that the valve seat member 13 be inserted into the annular ridge 35 formed at the front end of the valve seat member 13 at its base end while being held by the nut 34 so as not to move freely.

Further, the cylindrical main portion of the gun body 1 is provided with an air passage 36 for supplying air from the air opening/closing regulating valve 8 to the passage 12 in the valve seat member 13.

Based on the above configuration, the pressurized paint of about 20 to 30 kg/cm ² is supplied from the paint introduction pipe 4, and after being swirled in the paint swirling core 19 as the valve 14 opens, the paint is sent to the paint nozzle. The pressurized air of about 2 kg/cm ² is ejected as a conical spray from the outlet 18 of 7 and introduced through the pressurized air introduction pipe 2, from the opening/closing adjustment valve 8 to the flow path 36 and the valve seat member. The paint is ejected from the annular ejection port 9 of the air nozzle member 17 through the flow path 12, the annular groove 23, and the flow path 15 in the holder member so as to contact the outer circumferential surface of the paint spray, thereby promoting atomization and at the same time Adjust the size and shape of the pattern to the desired shape.

Further, at the front end of the core 19, a needle-shaped charged electrode 3 is provided which penetrates the center of the paint nozzle 7 and projects forward.
A resistor 38 provided in the cylindrical main portion of the gun body 1, a conductive wire 39 embedded in the valve seat member 13, and a conductive wire 40 embedded in the holder member 16 are provided, and the conductive wire 3 is connected to the paint nozzle 7 and the conductive wire 40 embedded in the holder member 16. A high voltage is applied to the needle-like electrode 37 that is electrically connected to this.
Note that instead of providing the needle-like electrode 37, the tip of the paint nozzle 7 may be sharpened and used in place of the needle-like electrode. Furthermore, when a conductive paint such as a water-based paint is used as the paint, a high voltage may be applied to the needle electrode 37 via the paint in the paint flow path.

In order to promote atomization, it is preferable to swirl the pressurized air, and in particular, swirling the air in the direction opposite to the swirling direction of the paint is particularly effective in promoting atomization. As shown in FIG.
1 and 41, or the flow path 15 in the holder member 16 is preferably provided with a tendency to twist with respect to the axis of the holder member 16 so as to accommodate the swirling of the flowing air.

The air nozzle member 17 is symmetrically provided with forward-facing angular protrusions 42, 42, and the protrusions 42 are formed with a flow path 43 and obliquely inward air nozzles 44, 44 communicating with this flow path 43. Further, the gun body 1 is provided with an air opening/closing adjustment valve 45 communicating with the pressurized air introduction pipe 2, and a flow path 46 communicating with the flow path 43 via this valve 45, so that the opening degree of the adjustment valve 45 can be adjusted. Accordingly, the paint spray is flattened into a fan shape as necessary by spraying pressurized air of about 2 kg/cm ² from the air nozzles 42, 42 between the conical spray.

As explained above, according to the present invention, by spraying the pressurized paint in a conical shape from the paint nozzle while swirling it, the propulsive effect due to the pressure of the paint itself and the propulsive effect due to centrifugal force are mutually effective. Not only does this effect promote atomization, but the atomization air is supplied from the surrounding area, which significantly improves the atomization effect and increases the discharge amount even when using high viscosity paint. The present invention can also be suitably applied to cases where thick film coating is to be performed, and a better spray pattern can be formed and controlled appropriately. In addition, the mechanism near the tip of the gun body is constructed separately from the gun body by a valve seat member, a paint nozzle, a holder member, an air nozzle member, a paint swirling core, a helical spring, a filter, a filter receiver, etc. Moreover, since they are fitted or screwed together so that they can be disassembled, not only can the equipment be made relatively small and lightweight, but maintenance such as cleaning and inspection and parts replacement is extremely easy, and parts replacement is also easy. It is effective in that it is sufficient to replace only a limited number of parts and the work is easy.

In addition, in this example, only a hand-held spray gun for electrostatic painting was explained, but the present invention
It should be understood that the present invention is applicable to a variety of paint spray guns, including but not limited to electrostatic and non-electrostatic, automatic and hand-held.

[Brief explanation of the drawing]

In the drawings, FIGS. 1 and 2 are a side view and a longitudinal sectional side view of essential parts of the electrostatic spray gun for painting of the present invention in one embodiment, respectively, and FIG. 3 is a configuration near the core and filter section. It is an exploded perspective view of a member. DESCRIPTION OF SYMBOLS 1... Gun body, 7... Paint nozzle, 9... Spout nozzle, 10... Paint flow path, 11... Valve seat, 12...
... Air flow path, 13 ... Valve seat member, 14 ... Valve, 1
5... Air flow path, 16... Holder member, 17...
...Air nozzle member, 18...Paint spout, 19...
...Swivel core, 20...Twin coil spring, 21...Filter, 22...Filter receiver.

Claims (1)

[Scope of utility model registration request] This is a gas-liquid pressurized spray gun that pressurizes the paint itself and atomizes it while at the same time supplying pressurized air from near the base of the spray to promote atomization. A paint passage 10 and a valve seat 1 are located near the tip of the gun body 1 where a passage is provided.
1 and a pressurized air flow path 12 are screwed together or fitted together, and the valve seat 11 is provided with a valve 14 that can be moved forward and backward at a timely manner. A cap-shaped holder member 16 having an air passage 15 in the front part is connected to the cap-shaped holder member 16 having an air outlet 9 from the outside so that the air passage 15 communicates with the passage 12 in the valve seat member 13. A paint nozzle 7 is fixed to the gun body 1 with the nozzle member 17 covered thereon, and has a paint spout 18 at the tip of the holder member 16.
is provided so that an annular gap is formed by the paint nozzle 7 in the spout 9, and a paint swirling core 19 is provided in the central inner cavity of the holder member 16 behind the paint nozzle 7. Nozzle 7
The filter 21 is attached and detached from the rear of the valve seat 11 while being pressed against the valve seat 11 by a helical spring 20.
A spray gun for painting is disposed while being fitted into a filter receiver 22 which has a flow path communicating with the filter receiver 22.