JPS6212429Y2 - - 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 amount and spray pattern, and is suitable for multiple coatings, so it is easy to work with, and the spray speed of the paint is slow, so it is extremely safe. It is unsuitable for spraying high viscosity paints, so the amount of solvent used is large, which goes against resource conservation, and the discharge amount is also relatively small, making it unsuitable for thick film coatings, resulting in low work efficiency and poor paint adhesion efficiency. There is. The latter type of airless spray gun has good work efficiency as it can handle large discharge volumes and form large spray patterns, 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.

Still another object is to provide a spray gun of this type that can adjust the amount of paint discharged.

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 valve seat 11 having a paint passage 10 and a tapered receiving surface is located near the tip of the gun body 1 where a paint passage and a pressurized air passage are provided.
A valve seat member 13 provided with a pressurized air flow path 12 is screwed or fitted, and a needle 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 has an air passage 15 in the front part of the valve seat member 13, and an air outlet 9 is provided from the outside thereof 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 an air nozzle member 17 placed over it, 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
A spray gun for painting is provided with a stopper 20 that can be freely attached and detached so as to face each other from the rear, and further includes a variable forward/backward stopper 20 in a portion near the rear end of the gun body 1 for regulating the degree of retraction of the needle valve 14. provided.

The present invention will be described in detail below based on 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. At the front, there is a paint flow path 10 and a valve seat 11 with a tapered receiving surface that fits into the front end of this flow path 10.
A valve seat member 13 having a pressurized air passage 12 and a valve seat member 13 is fixed so that the needle valve 14 at the tip of the valve rod 5 faces the valve seat 11, and the front end of the valve seat member 13 , a cap-like holder member 16 having an air passage 15 is attached to the air nozzle member 1 having the air outlet 9 such that the air passage 15 communicates with the passage 12 in the valve seat member 13.
7 is placed over the holder member 16 and is tightened and fixed to the front end of the gun body 1, and a paint nozzle 7 having a relatively small diameter paint spout 18 is press-fitted into the tip of the holder member 16. Fit together,
An annular gap is formed between the air nozzle member 17 and the air jet port 9, and a paint swirling core 19 is fitted from the rear of the paint nozzle 7 into the central inner cavity of the holder member 16 behind the paint nozzle 7. Furthermore, the needle valve 14 is provided in a conventional manner in order to steplessly and finely adjust the discharge amount by changing the cross-sectional area of the annular flow path when the valve is opened. Unlike the hemispherical valve shown in FIG.
Make it correspond to the rear end of.

It would be better if the valve seat member 13 is provided with an annular groove 21 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. Further, sealing between the valve seat member 13 and the cap-shaped holder member 16 to prevent paint leakage can be easily achieved by forming a packing receiving portion 22 between the two members 13 and 16 and fitting the annular packing 23 therein. can be done. The outer periphery of the cap-shaped holder member 16 is a conical tapered surface 24, which cooperates with the engaging tapered surface 25 of the inner cavity of the air nozzle member 17 to form the air flow path 15.
The leakage of pressurized air from the spray gun body 1 is reliably sealed, and both the members 16 and 17 are firmly fixed to the spray gun body 1 by the cap retainer 26 without being displaced. The valve seat 11 and the valve 1
4, as well as the nozzle 7, are usually made of cemented carbide. The tip of the nozzle 7 has a tapered conical shape, and the outer circumferential surface of the air outlet 9 has a similar conical shape, so that fine atomization can be achieved by ejecting the atomization promoting air from the annular gap in a tapered shape. Although it is desirable to obtain a good spray pattern, the sprays may be sprayed 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 28 that matches the conical receiving surface 27 of the paint nozzle 7, and a plurality of paint flow channels 29, 29 formed obliquely and radially on the conical surface 28. As shown in FIG. 2, the core 19 is preferably brought into pressure contact with the paint nozzle 7 from behind by a spring 30.

Behind the core 19, the filter 31 is mounted using the internal gap of the spring 30, and the outer periphery of the filter receiver 32 has a central passage connecting to the valve seat 11 and a plurality of slit passages branching laterally from the central passage. After the valve seat member 13 is fitted to the sides thereof, the valve seat member 13 is inserted into the annular ridge 34 formed at the front end of the valve seat member 13 at its base end while being held by the nut 33 so as not to move loosely.

Further, the cylindrical main portion of the gun body 1 is provided with an air passage 35 for supplying air from the air on/off 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 the valve 7 and introduced through the pressurized air introduction pipe 2. The paint is ejected from the annular ejection port 9 of the air nozzle member 17 through the flow path 12 in the holder member, the annular groove 21 in the holder member, and the flow path 15 in the holder member so as to contact the outer peripheral surface of the paint spray, thereby promoting atomization. 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 37 provided in the cylindrical main part of the gun body 1, a conducting wire 38 embedded in the valve seat member 13, and a conducting wire 39 embedded in the holder member 16 are provided in order from the conductive wire 3 to the paint nozzle 7 and the conductive wire 39 embedded in the holder member 16. A high voltage is applied to the needle-shaped electrode 36 that is electrically connected to this.
Note that instead of providing the needle-like electrode 36, the tip of the paint nozzle 7 may be sharpened and used in place of the needle-like electrode. Further, 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 36 through 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 has a significant effect on promoting atomization. As shown in FIG.
0,40, 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 41, 41, and the protrusions 41 are formed with a flow path 42 and obliquely inward air nozzles 43, 43 communicating with this flow path 42. Further, the gun body 1 is provided with an air opening/closing adjustment valve 44 communicating with the pressurized air introduction pipe 2, and a flow path 45 communicating with the flow path 42 via this valve 44, so that the opening degree of the adjustment valve 44 can be adjusted. Accordingly, the paint spray is flattened into a fan shape as required by spraying pressurized air of about 2 kg/cm ² from the air nozzles 43, 43 between the conical spray.

The core 19 for swirling the paint is not limited to the embodiments described above, but may be a cup-shaped or shallow tray-shaped swirling core 19 as in the embodiments of FIGS. 4 and 5 or the embodiments of FIGS. 6 and 7. Core 1 with chamber 46
9 may be provided with a tangential inlet passage 47 in its swirling chamber 46, and this core 19 may be pressed against the paint nozzle 7 by a spring 30.

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. It can be suitably applied to thick-film coatings, and the opening degree of the needle valve can be changed appropriately by adjusting the stopper, so the amount of paint discharged can be easily adjusted to form a good spray pattern. , control can be performed accurately and work efficiency can be improved. 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 turning core, etc., and each can be disassembled by fitting or screwing. Because it matched,
This not only allows the equipment to be made relatively small and lightweight, but also makes maintenance such as cleaning and inspection and parts replacement extremely easy, and parts replacement is easy as only a limited number of parts need to be replaced. It has the following effects.

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, FIG. 3 is a perspective view of only the core, and FIG. FIG. 5 is a vertical cross-sectional side view of only the vicinity of the core portion in the embodiment shown in FIG.
6 is a longitudinal sectional side view of only the vicinity of the core portion in yet another embodiment, and FIG. 7 is a longitudinal sectional front view taken along the line - in FIG. 6. 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 ... Needle valve,
15...Air flow path, 16...Holder member, 17
... Air nozzle member, 18 ... Paint spout, 19
...Swivel core, 20...Variable stopper, 2
7... Receiving surface, 28... Conical surface, 29... Paint flow path.

Claims (1)

[Claims for Utility Model Registration] 1. A gas-liquid pressurized spray gun that sprays the paint itself under pressure and simultaneously supplies pressurized air from near the base of the spray to promote atomization. A paint flow path 1 is provided near the tip of the gun body 1 where a paint flow path and a pressurized air path are provided.
0, a valve seat 11 with a tapered receiving surface, and a valve seat member 13 provided with a pressurized air flow path 12 are screwed together or fitted together, and a needle valve 14 that can be moved forward and backward in a timely manner from the valve seat 11 is provided. In addition, a cap-shaped holder member 16 having an air passage 15 is provided in the front part of the valve seat member 13 so that the air passage 15 communicates with the passage 12 in the valve seat member 13. An air nozzle member 17 having an air outlet 9 is placed over the gun body 1 from the outside and fixed to the gun body 1, and a paint nozzle 7 having a paint outlet 18 is attached to the tip of the holder member 16. , an annular gap is formed in the spout 9 by the paint nozzle 7, and a paint swirling core 1 is provided in the central inner cavity of the holder member 16 behind the paint nozzle 7.
9 is removably provided so as to face the paint nozzle 7 from behind, and furthermore, a variable advance/retreat stopper 20 is provided near the rear end of the gun body 1 to regulate the degree of retraction of the needle valve 14. Paint spray gun. 2. A conical receiving surface 27 is provided at the rear end of the paint nozzle 7, and the rotating core 19 for this is provided with a conical receiving surface 27.
A conical surface 28 that matches the receiving surface 27, and a plurality of paint channels 29 formed obliquely and radially on this conical surface.
A spray gun for painting according to claim 1 of the utility model registration claim, comprising: 3 Claims 1 or 2 for utility model registration in which the paint nozzle 7 and core 19 are made of cemented carbide
A spray gun for painting as described in section. 4 Utility model registration claim 1 comprising a charging electrode for charging the spray paint at the tip of the spray gun
The spray gun for painting according to item 1 or 3. 5. The spray gun for painting according to claim 1 or 4, in which the pressurized air outlet 9 has a conical shape that gradually narrows forward.