JP2993307B2 - Spray gun cap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray gun cap for spraying a liquid to be sprayed.

[0002]

2. Description of the Related Art Conventionally, there has been a coating operation for spraying a liquid to be sprayed using, for example, a spray gun. One of the liquids to be sprayed is a paint. As shown in FIGS. 7 to 9, a cap body 21 is attached to the spray gun 20, and a paint ejection hole 22 is formed in the front of the cap body 21. A cylindrical paint nozzle 24 into which a needle valve 23 is slidably inserted is inserted into the paint ejection hole 22, and when a trigger (not shown) of the spray gun is triggered, the pressure of the compressed air causes the paint ejection hole 22 to pass through the paint ejection hole 22. Sprayed to the outside.

[0003] A pair of air holes 25 located close to the paint ejection hole 22 and a pair of air holes located remote from the paint ejection hole 22 are provided around the periphery of the paint ejection hole 22 in front of the cap body 21. A hole 26 is drilled. The diameter of each of the air holes 25 and 26 having the front circular shape is the same, and air is blown out from each of the air holes 25 and 26 to form the paint spray hole 2.
In the vicinity of 2, the paint particles are subdivided and the atomization of the paint is promoted.

[0004]

However, in this conventional spray gun cap, the cap body 2
Air is also ejected from a gap 27 between the first paint ejection hole 22 and the paint nozzle 24, and a part of the air b ejected from this gap 27 is rewound to the paint ejection hole 22 side and becomes a turbulent flow. Therefore, the atomized paint is caused by the turbulent flow and the paint ejection hole 2
Since the paint is flowed to the second side and adheres to the vicinity of the paint ejection hole 22, there is a problem that the ejected paint drops and drips, causing shortness of spraying and unevenness of spraying.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a spray gun cap which can make it difficult for a liquid to be sprayed to adhere around a paint injection hole. .

[0006]

To achieve the above object, according to an aspect of, the invention according to claim 1, provided in the cap body, the spray gun cap paint with a paint injection out holes to be sprayed by the gas pressure , paint the paint ejection hole
Insert the nozzle and arrange the outer surface of the nozzle and the paint
When paint is sprayed from between the inner peripheral surface of the hole and
In addition, an expanding portion extending from the inside to the outside is provided on the inner peripheral surface of the paint ejection hole, and an outer end of the expanding portion and the paint nozzle are provided .
The gist of the present invention is that the outer end of the disk is set to be located at substantially the same position .

[0007] The invention of claim 2 is provided in the cap body, a paint injection out <br/> hole paint is sprayed by a gas pressure, established on the rim of the paint injection out hole, ejected A spray gun cap having a gas ejection hole through which a gas is ejected to the paint to promote atomization of the paint, wherein the paint ejection hole and the gas ejection hole are opened on the same plane.
And a plurality of gas outlets with different ejection areas
Those composed of a gas ejection hole, and summarized in that the ejection area of the gas ejection holes proximate position to said paint injection out hole and size rather set than the ejection area of the gas ejection holes for remotely located paint injection out hole is there.

[0008]

According to the first aspect of the present invention, the gas ejected from the paint ejection hole is ejected to the outside along the expanding portion without being turbulent from the cap body, and the sprayed paint is ejected from the paint ejection hole. So that it does not adhere to the periphery of the paint ejection hole.

[0009] According to the invention described in claim 2, gas blown from the close position of the paint injection out holes for ejecting force than gas blown from a remote location of the paint injection out hole is large, The sprayed paint does not adhere around the paint outlet.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a spray gun cap for painting a vehicle body will be described below with reference to the drawings.

As shown in FIG. 3, an air hose 3 is connected to a lower portion of the spray gun 1 via an air nipple 2,
Compressed air is fed from the air hose 3 into the spray gun 1 under pressure. A paint supply hose 19 is connected to the upper portion of the spray gun 1 via the nipple 4, and paint is sucked from the paint supply hose 19 into the spray gun 1 by the negative pressure generated in the spray gun 1 by compressed air. Is done. A cap body 5 is screwed and fixed to the front of the spray gun 1. A pair of air nozzles 6, 7 extending in the front direction are formed on the front surface of the cap body 5, and air ejection holes 8 communicating with the air hose 3 are formed on the side surfaces of the air nozzles 6, 7 facing each other.

As shown in FIGS. 1 and 3, a paint ejection hole 10 is formed in the center of the front of the cap body 5, and a paint nozzle 11 through which paint is ejected to the outside by compressed air. Has been idle. That is, the paint ejection hole 10
An air ejection gap 16 is formed between the inner peripheral surface of the paint nozzle 11 and the outer peripheral surface of the paint nozzle 11, and the air fed from the air hose 3 is ejected from the air ejection gap 16.

A needle valve 12, which extends in the axial direction and has a tapered tip, is slidably inserted into the injection hole 11a of the paint nozzle 11. The needle valve 12 is operatively connected to a trigger 13 of the spray gun 1 shown in FIG.
By pulling it toward the side, the needle valve 12 is moved in the direction of arrow Y in FIG. 1 against the urging force of a coil spring (not shown). The trigger 13 of the spray gun 1 is always urged by the coil spring (not shown) to the opposite side of the handle 14 of the spray gun 1.

A tapered expanding portion 10a which expands in the direction of the outer end is formed from the center to the outer end of the path along the axial center of the paint jetting hole 10. The outer end of the expanding portion 10a and the outer end surface of the paint nozzle 11 are located at the same position. The air flow a (shown in FIG. 1) of the air ejected from the air ejection gap 16 flows along the expanding portion 10a and is ejected together with the paint sprayed from the ejection hole 11a of the paint nozzle 11. Is done.

As shown in FIG. 2, a thick hole 17 as a pair of gas ejection holes having a front circular shape is formed at a position close to the periphery of the paint ejection hole 10, and at a position remote from the periphery of the paint ejection hole 10. In the figure, pores 18 are formed as gas ejection holes. The diameter of the thick hole 17 is 1.2 mm, while
The diameter of the fine holes 18 is 0.5 mm, and the area of the air passing through the large holes 17 is larger than that of the fine holes 18. That is, the thick hole 17 and the fine hole 1
The large amount of air passing through the large holes 17 is ejected more than the small holes 18 in terms of the amount of air passing per predetermined time passing through the small holes 8.

Next, the operation of the spray gun cap configured as described above will be described. When gripping the handle 14 of the spray gun 1 and pulling the trigger 13 toward the handle 14,
The needle valve 12 is slid in the Y direction, and the air hose 3 is moved.
, Compressed air is supplied into the cap body 5. And air is thick hole 17, fine hole 18, each air nozzle 6,7,
The air is sprayed outward and forward from the air gap 16 and the injection hole 11 a of the paint nozzle 11. Then, the paint in the paint supply hose 19 is sucked into the cap body 5 by the negative pressure.

The paint is applied to the spray hole 1 of the paint nozzle 11.
1a, the paint is sprayed to the outside through the expanding portion 10a by the pressure of the air, and the sprayed paint is sprayed through the thick hole 17a.
To be pressurized gills are in spray pressure of the air from the pores 18.

Further, the air jetted from the air jet holes 8 (only one is shown) of each of the air nozzles 6 and 7 in a direction facing each other forms a thick hole 17, a fine hole 18 and each of the air nozzles 6.
7 is ejected in a direction orthogonal to the paint sprayed forward, and is turbulently mixed near the front position of the cap body 5 , so that the particles of the sprayed paint are further fragmented and is sprayed spread elliptical cross-sectional shape. At this time, when spraying, the air ejection gap 1
The air flow a ejected from the diverging portion 6 is not turbulent,
It is ejected to the outside along a. Thus, paint is uniformly ejected by air without stick to a periphery of the expanding portion 10a of the paint ejection orifice 10.

Further, since the air ejection flow rate in per predetermined time from the large hole 17 is larger than that of the air ejection flow from the pores 18, injection of the coating material nozzle 11 increases the air ejection force
Morphism hole 11a outer end periphery paint is unlikely to adhere to.

Next, by using a spray gun cap having one of the expanding portion 10a and the thick hole 17 and a conventional spray gun cap having neither of them, a low atomizing pressure and a high atomizing pressure are used. The experiment was carried out. The results are shown in the table below.

In each of the experiments, the measurement was performed for 10 minutes. Also, in any of the tables, those having no enlarged diameter portion 10a show the same configuration as the prior art, and those having no thick hole 17 have a thick hole 17a.
Instead of using the cap body 5, a cap body 5 having a pore 18 is used.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

[Table 3]

[0025] Thus, Oite the spray gun cap of this embodiment, by the paint ejection orifice 10 to form a diverging portion 10a extending over from the axial center portion to the outer end, air jet The air flow a ejected from the gap 16 is
Since the paint flows along the expanding portion 10a, the paint does not adhere to the expanding portion 10a, and the paint on the front outside the expanding portion 10a hardly adheres due to the airflow a flowing along the expanding portion 10a. . As a result, the paint is less likely to adhere to the periphery of the paint ejection hole 10 , and it is possible to prevent the ejected paint from dropping and dripping, shortness of spraying, and uneven spraying. Can last for a long time.

Further, the diameter of the large hole 17 to the close position to the paint injection out hole 10, the pores close position to the paint injection out hole 10 18
Larger than the diameter. Therefore, since the ejection area of the large hole 17 is larger than the ejection area of the small holes 18, the amount of air ejected from the large holes 17 is larger than that of the small holes 18. For this reason, paint can be made hard to adhere to the vicinity of the periphery of the injection hole 11a of the paint nozzle 11, and it is possible to prevent the ejected paint from dropping and dripping, shortness of spraying, and uneven spraying. it can.

Further, as can be seen from any of the experimental results, the cap body 5 having the widened portion 10a and the thick hole 17 is provided.
In both the low fog pressure and the high fog pressure, the number of times of application of the paint around the paint ejection hole is 0 to 1, and the widening portion 10a and the thick hole 17 are used.
In particular, a remarkable effect was obtained under the condition of low fog pressure, as compared with those without any of the above.

The present invention is not limited to the above-described embodiment, and may be arbitrarily changed without departing from the spirit of the invention. (1) Although the tapered expanding portion 10a is provided in the above embodiment, the expanding portion 30 may have a rounded cross section as shown in FIG.

(2) In addition to the expanded portion 10a of the above embodiment, an expanded portion 31 having a tapered portion whose outer edge further expands may be provided.

[0030]

According to the first aspect of the present invention, the gas from the paint ejection hole is ejected along the expanding portion, so that the noise is reduced.
Turbulence is unlikely to occur at the outer end of the
Therefore, it is possible to prevent the paint from adhering around the paint ejection hole.

Further, according to the present invention, the paint is ejected.
The gas injection position near the hole around out paint <br/> injection which is opened a hole and a plurality of gas ejection holes on the same plane have a power as compared with the gas injection remote location, paint in the paint injection out hole Can be prevented from adhering.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of a cap body according to the present embodiment, and is an AA sectional view in FIG.

FIG. 2 is an enlarged front view showing a paint ejection hole and a fluid ejection hole.

FIG. 3 is a side view showing a state where the cap body is attached to the spray gun.

FIG. 4 is a perspective view showing a state where the cap body is attached to the spray gun.

FIG. 5 is a partial longitudinal sectional view of a cap body according to another embodiment.

FIG. 6 is a partial longitudinal sectional view of a cap body according to another embodiment.

7 is a partial longitudinal sectional view of a cap body according to a conventional technique, and is a sectional view taken along the line BB in FIG. 9;

FIG. 8 is an enlarged front view of a paint ejection hole and a fluid ejection hole.

FIG. 9 is a perspective view showing a state where the cap body is attached to the spray gun.

[Reference Numerals] 5 ... cap body, 10 ... coating injection out hole, 10a ... expanding portion, 17 ... large hole (gas ejection holes), 18 ... pore (gas ejection hole)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B05B 1/02 101 B05B 1/26

Claims (2)

(57) [Claims] 1. A provided in the cap body (5), the spray gun cap paint with a paint injection out holes to be sprayed (10) by a gas pressure, the coating material nozzle in the paint ejection hole (10) (11) Insert
And the outer peripheral surface of the nozzle (11) and the paint ejection hole (1).
0) When paint is sprayed from between the inner peripheral surface and
Both the expansion portion on the inner circumferential surface extends over the inner outward paint ejection hole (10) and (10a) is provided, the expanding portion
The outer end of (10a) and the outer end of the paint nozzle (11)
A spray gun cap characterized by being set to be located at substantially the same position . Wherein provided on the cap body (5), a paint injection out hole (10) the paint is sprayed by a gas pressure, paint injection
Established on the rim of the exit hole (10), the spray gun cap having a gas ejection hole which the gas is ejected (17, 18) for the coating material to promote atomization of the ejected paint, The paint outlet (10) and the gas outlet (17, 18)
Are opened on the same plane, and the gas ejection holes (1
7, 18) through a plurality of gas ejection holes (1) with different ejection areas.
Constituted by 7, 18), the ejection area of the gas ejection holes for remotely positioning the ejection area to paint injection out holes (10) (18) of the gas ejection holes proximate position to said paint injection out holes (10) (17) spray gun cap, characterized in that it was rather large set than.