阅读说明：本技术 热水器搪瓷内胆用喷枪及其喷枪组 (Spray gun for enamel inner container of water heater and spray gun group thereof ) 是由 吴海波 于 2021-01-30 设计创作，主要内容包括：一种热水器搪瓷内胆用喷枪及其喷枪组,其中,喷枪包括空气帽、涂料枪嘴、枪帽和枪身,涂料枪嘴设在枪身内,枪帽的上沿从上至下依次将空气帽、涂料枪嘴和第一密封圈压紧；在喷嘴上设有涂料喷孔,在空气帽的上底面上设有第一喷幅气嘴和第二喷幅气嘴,第一喷幅气嘴具有朝向向上的第一斜面,在第一斜面上至少设有一个喷射空气的第一喷幅孔,第二喷幅气嘴具有朝向向上的第二斜面,在第二斜面上至少设有一个喷射空气的第二喷幅孔；其中,第一喷幅气嘴的第一斜面与空气帽的上底面的第一相交线的第一延长线与上底面的过圆心的X向轴线或Y向轴线呈第一夹角α,第一夹角α在3度至33度之间选择。本发明具有适合于对热水器内胆的内表面,尤其是对热水器内胆的两端的球缺的内表面进行喷涂的优点。(A spray gun for an enamel liner of a water heater and a spray gun group thereof are disclosed, wherein the spray gun comprises an air cap, a coating gun nozzle, a gun cap and a gun body, the coating gun nozzle is arranged in the gun body, and the air cap, the coating gun nozzle and a first sealing ring are sequentially pressed by the upper edge of the gun cap from top to bottom; the air cap is provided with a coating spray hole, the upper bottom surface of the air cap is provided with a first amplitude air nozzle and a second amplitude air nozzle, the first amplitude air nozzle is provided with a first inclined surface facing upwards, the first inclined surface is at least provided with a first amplitude hole for spraying air, the second amplitude air nozzle is provided with a second inclined surface facing upwards, and the second inclined surface is at least provided with a second amplitude hole for spraying air; wherein, a first included angle alpha is formed between a first extension line of a first intersection line of the first inclined plane of the first spray nozzle and the upper bottom surface of the air cap and an X-direction axis or a Y-direction axis of the upper bottom surface passing through the center of a circle, and the first included angle alpha is selected from 3 degrees to 33 degrees. The spraying device has the advantage of being suitable for spraying the inner surface of the water heater liner, in particular the inner surfaces of the ball notches at the two ends of the water heater liner.)

1. The utility model provides a spray gun for water heater enamel inner bag which characterized in that: the paint gun comprises an air cap (1), a paint gun nozzle (2), a gun cap (3) and a gun body (4), wherein the paint gun nozzle (2) is arranged in a concave part (41) of the gun body (4), a first sealing ring (5) for separating an air channel from the paint channel is arranged between the lower bottom surface of the paint gun nozzle (2) and the inner bottom surface of the concave part (41) of the gun body (4), the air cap (1) is arranged on the paint gun nozzle (2), the gun cap (3) is arranged on the gun body (4), and the upper edge (31) of the gun cap (3) sequentially compresses the air cap (1), the paint gun nozzle (2) and the first sealing ring (5) from top to bottom; a through hole (11) is formed in the center of the air cap (1), a nozzle (21) of the paint gun nozzle (2) extends into the through hole (11), an air atomizing ring (12) is formed between the inner wall of the through hole (11) and the nozzle (21), and a paint spray hole (211) is formed in the nozzle (21); a first air nozzle (22) and a second air nozzle (23) are arranged on the upper bottom surface (13) of the air cap (1), the first air nozzle (22) is provided with a first inclined surface (221) facing upwards, at least one first air nozzle hole (222) for spraying air is arranged on the first inclined surface (221), the second air nozzle (23) is provided with a second inclined surface (231) facing upwards, and at least one second air nozzle hole (232) for spraying air is arranged on the second inclined surface (231); a first extension line (224) of a first intersection line (223) of a first inclined plane (221) of the first air nozzle (22) and an upper bottom surface (13) of the air cap (1) and an X-direction axis or a Y-direction axis (131) of the upper bottom surface (13) passing through the center of a circle form a first included angle (alpha), and the first included angle (alpha) is selected from 3 degrees to 33 degrees.

2. The spray gun for the enamel inner container of the water heater as claimed in claim 1, wherein: the second air nozzle (23) and the first air nozzle (22) are arranged in a mirror image mode by taking the X-axis or the Y-axis (131) as a symmetry line.

3. The spray gun for enamel inner containers of water heaters as claimed in claim 1 or 2, wherein: a first air inlet (421) and a first paint inlet (422) are arranged on the side surface (42) of the gun body (4), the first air inlet (421) is communicated with the air atomizing ring (12), the first width spraying hole (222) and the second width spraying hole (232), and the first paint inlet (422) is communicated with the paint spraying hole (211); or/and a second air inlet (431) and a second paint inlet (432) are arranged on the bottom surface (43) of the gun body (4), the second air inlet (431) is communicated with the air atomizing ring (12), the first spray width hole (222) and the second spray width hole (232), and the second paint inlet (432) is communicated with the paint spray holes (211).

4. The spray gun for the enamel inner container of the water heater as claimed in claim 3, wherein: the gun body (4) is also provided with a side air hole (423), and the side air hole (423) is communicated with the first air inlet (421) or/and the second air inlet (431).

5. The spray gun for the enamel inner container of the water heater as claimed in claim 3, wherein: the coating material spraying hole (211) is divided into two sections, wherein the first section is a vertical section (2111), the other section is an oblique section (2112), the vertical section (2111) is communicated with the first coating material inlet (422) or/and the second coating material inlet (432), the central line of the oblique section (2112) is intersected with the horizontal line of the vertical section (2111) to form a second included angle (beta), and the second included angle (beta) is selected from 30-60 degrees.

6. The spray gun for the enamel inner container of the water heater as claimed in claim 3, wherein: an air guide ring (14) is arranged on the lower bottom surface of the air cap (1), a plurality of air guide holes (141) are formed in the air guide ring (14), and the first air inlet (421), the second air inlet (431), the air atomization ring (12), the first amplitude spraying hole (222) and the second amplitude spraying hole (232) are communicated through the air guide holes (141).

7. The spray gun for enamel inner containers of water heaters as claimed in claim 1 or 2, wherein: at least two first inclined holes (121) are formed in the air cap (1) along the periphery of the air atomization ring (12), the two first inclined holes (121) are symmetrically distributed, and the air outlet direction of the two first inclined holes (121) faces the air atomization ring (12).

8. The spray gun for the enamel inner container of the water heater as claimed in claim 7, wherein: a second inclined hole (122) is further formed in the air cap (1) along the periphery of the air atomization ring (12), the air outlet direction of the second inclined hole (122) faces the air atomization ring (12), and the second inclined hole (122) and the two first inclined holes (121) are arranged in a delta shape.

9. The spray gun for enamel inner containers of water heaters as claimed in claim 1 or 2, wherein: the included angle between the first inclined plane (221) and the upper bottom surface of the air cap (1) is selected from 40 degrees to 70 degrees.

10. The utility model provides a spray gun group for water heater enamel inner bag which characterized in that: spray gun for the enamel liner of a water heater comprising one of claims 1 to 9.

Technical Field

The invention relates to the technical field of water heater liner enamel, in particular to a spray gun for a water heater enamel liner and a spray gun group thereof.

Background

Common enameling methods include powder spreading enameling method, electrostatic enameling method, dip enameling method, roll enameling method and spray enameling method, the powder spreading enameling method is a method for spreading glaze powder on the surface of a heated workpiece for enameling, and the method is only suitable for enameling the outer surface of the workpiece and is not suitable for enameling the inner surface of a water heater inner container; the electrostatic enameling method is mainly suitable for large-area planes, workpieces are electrified, the uniformity of the coating thickness of the inner surface of the water heater inner container can not be controlled when the inner surface of the water heater inner container is enamelled, and in addition, the volume of the electrostatic spray gun is generally larger than that of a common spray gun, so that the inner container cannot enter the inner cavity of the inner container from the inner container opening of the water heater inner container; the enameling method is suitable for workpieces of which the inner wall and the outer wall both need enamel, and is suitable for enameling of the inner container of the water heater, but the inner container of the water heater only needs to be enameled on the inner surface of the inner container of the water heater under the normal condition, and if the outer surface of the inner container of the water heater is also enameled, the enameling cost is inevitably high; in addition, the coating of the enamel dipping method is thicker, the using amount of the glaze slurry is larger, and the glaze cost and the firing cost of the inner container of the water heater are improved; then, the coating thickness of the dip-coating method is not uniform, and the quality is not high; the enamel rolling method is characterized in that firstly, the glaze slip is poured into the liner, then the liner is continuously rotated to enable the glaze slip coating to flow in the inner cavity of the liner, so that the glaze slip is attached to the inner wall of the liner, and then the redundant glaze slip is poured out; in addition, the coating thickness of the rolling and honing method is not uniform, and the quality is not high; the spray enameling method is similar to a paint spraying process and has the advantages of less glaze material consumption and uniform coating thickness, but the existing spray enameling method is mainly suitable for spraying large-area planar glaze powder or glaze slurry, and if the spray enameling method is used for spraying the inner surface of a water heater liner, two problems exist, namely, the spray enameling method does not enter the water heater liner because the spraying device is too large in size and the inlet of the water heater liner is generally very small; secondly, even if the spraying device is made small in size and can be placed in the inner container of the water heater, the existing spray gun cannot spray the inner surfaces of the ball notches at the two ends of the inner container of the water heater due to the structural limitation. Therefore, the spray gun for the enamel inner container of the water heater and the spray gun group thereof, which are suitable for spraying the inner surface of the inner container of the water heater, particularly the inner surfaces of the ball notches at the two ends of the inner container of the water heater, are urgently needed in the market.

Disclosure of Invention

In order to overcome the problems, the invention provides a spray gun for an enamel inner container of a water heater and a spray gun group thereof, which are suitable for spraying the inner surface of the inner container of the water heater, in particular the inner surfaces of ball notches at two ends of the inner container of the water heater.

The technical scheme of the invention is as follows: the spray gun for the enamel inner container of the water heater comprises an air cap, a coating gun nozzle, a gun cap and a gun body, wherein the coating gun nozzle is arranged in a concave part of the gun body, a first sealing ring for separating an air channel from the coating channel is arranged between the lower bottom surface of the coating gun nozzle and the inner bottom surface of the concave part of the gun body, the air cap is arranged above the coating gun nozzle, the gun cap is arranged on the gun body, and the air cap, the coating gun nozzle and the first sealing ring are sequentially pressed by the upper edge of the gun cap from top to bottom; a through hole is formed in the center of the air cap, a nozzle of the coating gun nozzle extends into the through hole, an air atomizing ring is formed between the inner wall of the through hole and the nozzle, and a coating spray hole is formed in the nozzle; the upper bottom surface of the air cap is provided with a first amplitude spraying air nozzle and a second amplitude spraying air nozzle, the first amplitude spraying air nozzle is provided with a first inclined surface facing upwards, the first inclined surface is at least provided with a first amplitude spraying hole for spraying air, the second amplitude spraying air nozzle is provided with a second inclined surface facing upwards, and the second inclined surface is at least provided with a second amplitude spraying hole for spraying air; wherein, a first included angle alpha is formed between a first extension line of a first intersection line of the first inclined plane of the first air nozzle and the upper bottom surface of the air cap and an X-direction axis or a Y-direction axis of the upper bottom surface passing through the center of the circle, and the first included angle alpha is selected from 3 degrees to 33 degrees.

As an improvement of the present invention, the second air nozzle and the first air nozzle are arranged in a mirror image manner with the X-axis or the Y-axis as a symmetry line.

As an improvement of the invention, a first air inlet and a first paint inlet are arranged on the side surface of the gun body, the first air inlet is communicated with the air atomizing ring, the first amplitude spraying hole and the second amplitude spraying hole, and the first paint inlet is communicated with the paint spraying hole; and the bottom surface of the gun body is provided with a second air inlet and a second coating inlet, the second air inlet is communicated with the air atomization ring, the first amplitude spraying hole and the second amplitude spraying hole, and the second coating inlet is communicated with the coating spraying hole.

As an improvement of the invention, the gun body is also provided with a side air hole which is communicated with the first air inlet or/and the second air inlet.

As an improvement to the present invention, the paint nozzle hole is divided into two sections, wherein a first section is a vertical section, and the other section is an oblique section, the vertical section is communicated with the first paint inlet or/and the second paint inlet, a central line of the oblique section intersects a horizontal line of the vertical section to form a second included angle β, and the second included angle β is selected from 30 degrees to 60 degrees.

As an improvement of the invention, an air guide ring is arranged on the lower bottom surface of the air cap, a plurality of air guide holes are arranged on the air guide ring, and the air guide holes are used for communicating the first air inlet, the second air inlet, the air atomizing ring, the first amplitude spraying hole and the second amplitude spraying hole.

As an improvement to the present invention, at least two first inclined holes are arranged on the air cap along the periphery of the air atomizing ring, the two first inclined holes are symmetrically distributed, and the air outlet directions of the two first inclined holes face the air atomizing ring.

As an improvement of the invention, the included angle between the first inclined surface and the upper bottom surface of the air cap is selected from 40 degrees to 70 degrees. A third spray width hole is also formed in the first inclined surface, and the center line of the first spray width hole and the center line of the third spray width hole are perpendicular to the first inclined surface; the included angle between the second inclined plane and the upper bottom surface of the air cap is selected from 40 degrees to 70 degrees. And a fourth spraying hole is also formed in the second inclined plane, and the central lines of the second spraying hole and the fourth spraying hole are perpendicular to the second inclined plane.

The invention also provides a spray gun group for the enamel inner container of the water heater, which comprises the spray gun for the enamel inner container of the water heater.

The center of the air cap is provided with a through hole, the nozzle of the coating gun nozzle extends into the through hole, an air atomizing ring is formed between the inner wall of the through hole and the nozzle, and the nozzle is provided with a coating spray hole; the upper bottom surface of the air cap is provided with a first amplitude spraying air nozzle and a second amplitude spraying air nozzle, the first amplitude spraying air nozzle is provided with a first inclined surface facing upwards, the first inclined surface is at least provided with a first amplitude spraying hole for spraying air, the second amplitude spraying air nozzle is provided with a second inclined surface facing upwards, and the second inclined surface is at least provided with a second amplitude spraying hole for spraying air; the structure is characterized in that a first included angle alpha is formed between a first extension line of a first intersection line of a first inclined plane of the first air jet nozzle and the upper bottom surface of the air cap and an X-direction axis or a Y-direction axis of the upper bottom surface passing through the center of a circle, and the first included angle alpha is selected from 3 degrees to 33 degrees.

Drawings

Fig. 1 is a schematic perspective exploded view of the present invention.

Fig. 2 is a schematic perspective view of the assembled structure of fig. 1.

Fig. 3 is a perspective view of fig. 2 from another angle.

Fig. 4 is a schematic plan view of the structure of fig. 2.

Fig. 5 is a schematic sectional structure view of a-a in fig. 4.

Fig. 6 is a perspective view of the air cap of fig. 1.

Fig. 7 is a schematic top view of the structure of fig. 6.

Fig. 8 is a schematic sectional structure view of B-B in fig. 7.

Fig. 9 is a perspective view of the paint gun nozzle of fig. 1.

Fig. 10 is a schematic view of the middle section of fig. 9.

Fig. 11 is an enlarged perspective view of the gun cap of fig. 1.

Fig. 12 is a perspective view of the gun body of fig. 1.

Fig. 13 is a schematic view of the partial cross-section of fig. 12.

Fig. 14 is a side view schematic of the structure of fig. 12.

Fig. 15 is a schematic cross-sectional structure view of C-C in fig. 14.

FIG. 16 is a schematic plan view of the spray gun assembly of the present invention.

Fig. 17 is a schematic view of the use state structure of fig. 16.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1 to 15, fig. 1 to 15 disclose a spray gun for an enamel liner of a water heater, which comprises an air cap 1, a paint nozzle 2, a gun cap 3 and a gun body 4, wherein the paint nozzle 2 is arranged in a concave part 41 of the gun body 4, a first sealing ring 5 for separating an air channel from a paint channel is arranged between the lower bottom surface of the paint nozzle 2 and the inner bottom surface of the concave part 41 of the gun body 4, and a second sealing ring 6 for blocking air leakage is arranged between the air cap 1 and the gun cap 3; the air cap 1 is arranged on the coating gun nozzle 2, the gun cap 3 is arranged on the gun body 4 in a threaded 424 connection mode, and the upper edge 31 of the gun cap 3 sequentially compresses the second sealing ring 6, the air cap 1, the coating gun nozzle 2 and the first sealing ring 5 from top to bottom; a through hole 11 is arranged at the center of the air cap 1, a nozzle 21 of the paint gun nozzle 2 extends into the through hole 11, an air atomizing ring 12 is formed between the inner wall of the through hole 11 and the nozzle 21, and a paint spraying hole 211 is arranged on the nozzle 21; a first air nozzle 22 and a second air nozzle 23 are arranged on the upper bottom surface 13 of the air cap 1, the first air nozzle 22 has a first inclined surface 221 facing upward, at least one first air hole 222 for injecting air is arranged on the first inclined surface 221, the second air nozzle 23 has a second inclined surface 231 facing upward, at least one second air hole 232 for injecting air is arranged on the second inclined surface 231, in this embodiment, two first air holes 222 and two second air holes 232 are provided; a first extension line 224 of a first intersection line 223 of the first inclined surface 221 of the first air nozzle 22 and the upper bottom surface 13 of the air cap 1 forms a first included angle α (see fig. 7) with the X-axis or Y-axis 131 of the upper bottom surface 13 passing through the center of the circle, and the first included angle α is selected from 3 degrees to 33 degrees. The different values of the first included angle alpha are selected to change the direction of the spray amplitude so as to effectively spray the inner surface of the arc top end of the inner container of the water heater.

Preferably, the second nozzle 23 and the first nozzle 22 are arranged in a mirror image manner with the X-axis or the Y-axis 131 as a symmetry line, so that a larger nozzle area can be obtained and the form of the nozzle sector can be controlled.

Preferably, a first air inlet 421 and a first paint inlet 422 are provided on the side surface 42 of the gun body 4, the first air inlet 421 is communicated with the air atomizing ring 12, the first nozzle holes 222 and the second nozzle holes 232, compressed air entering from the first air inlet 421 can be sprayed from the air atomizing ring 12, the first nozzle holes 222 and the second nozzle holes 232, and the first paint inlet 422 is communicated with the paint nozzle holes 211; or/and a second air inlet 431 and a second paint inlet 432 are arranged on the bottom surface 43 of the gun body 4, the second air inlet 431 is communicated with the air atomizing ring 12, the first spray width holes 222 and the second spray width holes 232, compressed air entering from the second air inlet 431 can be sprayed out from the air atomizing ring 12, the first spray width holes 222 and the second spray width holes 232, the second paint inlet 432 is communicated with the paint spray holes 211 (see fig. 3), and the second air inlet 431 and the second paint holes 432 are arranged to improve the mold opening universality of the spray gun and to facilitate and smooth installation of an air pipe and a paint pipe when the spray gun is installed. In this embodiment, the first air inlet 421 is communicated with the second air inlet 431, and the first paint inlet 422 is communicated with the second paint inlet 432, when in use, only one of the first air inlet 421 and the second air inlet 431 is connected with an air inlet pipe, and the other air inlet is blocked or connected with other spray heads in series, wherein the specific use is determined according to actual conditions; the first dope inlet 422 and the second dope inlet 432 are selected one for use and the other is blocked according to actual conditions. A plurality of connection holes 433 for connection of the stay bars are further provided in the bottom surface 43.

Preferably, the body 4 is further provided with side air holes 423, the side air holes 423 are communicated with the first air inlet 421 or/and the second air inlet 431 through air grooves 425 (see fig. 15), and the purpose of the side air holes 423 is to facilitate the connection of air pipes in series between adjacent nozzles.

Preferably, the paint nozzle hole 211 is divided into two sections (see fig. 10), wherein a first section is a vertical section 2111, and the other section is an oblique section 2112, the vertical section 2111 is communicated with the first paint inlet 422 or/and the second paint inlet 432, a central line 2113 of the oblique section 2112 intersects with a horizontal line 2114 of the vertical section 2111 to form a second included angle β, the second included angle β is selected from 30 degrees to 60 degrees, and the second included angle β is set to facilitate adjustment of the spraying direction, and the spraying direction of the paint can be changed by rotating the direction of the paint gun nozzle 2. In this case, it is possible to achieve that the gun body 4 enters the tank under positive conditions (ensuring a small installation dimension at the time of positive), and completely covers the inner surface of the tank during spraying.

Preferably, an air guide ring 14 (see fig. 6) is disposed on the lower bottom surface of the air cap 1, and a plurality of air guide holes 141 are disposed on the air guide ring 14, so that the air guide ring 14 can divide the compressed air to the atomizing ring 12 and make the air outlet of the entire ring uniform. In this embodiment, the number of the air holes 141 is 8, and the air holes 141 are uniformly formed in the air guide ring 14, and the air holes 141 communicate the first air inlet 421, the second air inlet 431, the air atomizing ring 12, the first swath holes 222, and the second swath holes 232. The air holes 141 are obliquely upward air holes, a center line 1411 of the air holes 141 intersects with a bottom plane 1412 of the air guide ring 14 to form a third included angle γ, and the third included angle γ is selected from 30 degrees to 80 degrees. The lower bottom ring of the air guide ring 14 is a first inclined ring 143 (see fig. 8), the upper surface of the middle portion 23 of the paint nozzle 2 is a second inclined surface 231 matched with the inclination of the first inclined ring 143, and the first inclined surface 143 presses on the second inclined surface 231 (see fig. 9), so that the upper edge 31 of the gun cap 3 is facilitated to sequentially press the second sealing ring 6, the air cap 1, the paint nozzle 2 and the first sealing ring 5 from top to bottom.

Preferably, at least two first inclined holes 121 (see fig. 7) are formed in the air cap 1 along the periphery of the air atomizing ring 12, the two first inclined holes 121 are symmetrically distributed, and the air outlet directions of the two first inclined holes 121 face the air atomizing ring 12. A second inclined hole 122 is further formed in the air cap 1 along the periphery of the air atomization ring 12, the air outlet direction of the second inclined hole 122 faces the air atomization ring 12, and the second inclined hole 122 and the two first inclined holes 121 are arranged in a delta shape; the central lines of the first inclined hole 121 and the second inclined hole 122 form a fourth included angle with the upper bottom surface 13 of the air cap 1, and the fourth included angle is selected from 40 degrees to 70 degrees. Third holes 123 are further formed in the air cap 1 along the periphery of the air atomizing ring 12, the third holes 123 may be perpendicular to the air cap 1, or may be inclined by a predetermined angle toward the air atomizing ring 12 with respect to a central perpendicular line of the third holes 123, or inclined by a predetermined angle away from the air atomizing ring 12, and the predetermined angle may be selected from 1 degree to 15 degrees; the third hole 123 may be replaced by an arc-shaped groove corresponding to the arc of the air atomization ring 12, and the third hole 123 may be replaced by a plurality of holes (not shown) arranged in an arc corresponding to the arc of the air atomization ring 12. The plurality of first inclined holes 121, second inclined holes 122, and third holes 123 are provided to further improve the degree of atomization of the coating material.

Preferably, the angle δ between the first inclined surface 221 and the upper bottom surface 13 of the air cap 1 is selected between 40 degrees and 70 degrees. The first inclined plane 221 is further provided with a third spraying hole 225, and the center line of the first spraying hole 221 and the third spraying hole 225 is perpendicular to the first inclined plane 221; the angle between the second inclined surface 231 and the upper bottom surface 13 of the air cap 1 is selected from 40 degrees to 70 degrees. A fourth spraying hole 235 is further disposed on the second inclined surface 231, and a central line of the second spraying hole 231 and the central line of the fourth spraying hole 235 are perpendicular to the second inclined surface 231. By the design, a larger spray width area can be obtained, and atomized paint can be quickly and accurately sprayed on the inner surface of the liner.

The coating in the present invention may be a glaze.

Referring to fig. 16 and 17, the invention further provides a spray gun set for the enamel liner of the water heater, which comprises the spray gun for the enamel liner of the water heater. Specifically, the spray gun set 100 for the enamel liner of the water heater in the invention comprises an upper spray gun 110, a middle spray gun 120 and a lower spray gun 130, in practical use, according to the length of the liner 150 of the water heater, a plurality of middle spray guns 120 (not shown) can be arranged, air pipes in the upper spray gun 110, the middle spray gun 120 and the lower spray gun 130 are connected in series, and feed pipes are respectively connected (connected in a connection manner in table one) to reduce the volume of the spray gun set 100 for the enamel liner of the water heater, and the upper spray gun 110, the middle spray gun 120 and the lower spray gun 130 are all arranged on a support rod 140.

When the number of the spray guns is three, the spray guns can be arranged up, middle and down, and the connectors of the spray guns are connected according to the mode of table one and middle. Watch 1

	A first air inlet	Second air inlet	Side air hole	The first coating inlet	Second coating inlet
						Upper spray gun	Ⅹ	√	Ⅹ	Ⅹ	√
Middle spray gun	√	Ⅹ	√	√	Ⅹ
						Lower spray gun	√	Ⅹ	√	√	Ⅹ

X in the above table represents clogging, and √ represents a connection.

When the invention is used, the water-saving agent is added,

(1) firstly, connecting a paint inlet paint and an air inlet air on a gun body 1 with a standard PT1/4 pipe joint;

(2) sending the compressed air filtered by 2-4 Bar into the air hole air, and shunting and sending out the air through an air cap;

(3) 1-2 Bar coating (glaze slip in the embodiment) is sent into the coating paint hole, and the coating is sprayed out through a gun nozzle;

(4) the compressed air sent out by the air cap breaks up the paint sprayed out of the gun nozzle and fully mixes the paint;

(5) the atomized coating formed after mixing with the compressed air is attached to the surface of the workpiece forwards;

(6) the thickness of the coating can be effectively controlled by controlling the spraying time and the glaze slurry discharge amount.

Various equivalent changes made by applying the contents of the specification and the drawings are included in the scope of the claims of the invention without departing from the idea of the invention.