JPH0220302B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a round spray gun that can form a circular or ring-shaped application surface with a relatively large diameter.

[Prior Art] Conventionally, a spray gun discharges air from a corner protruding from its nozzle body to flatten the spray pattern and spray the spray gun flat, thereby improving painting efficiency. However, when applying a mold release agent individually to a circular object, such as a circular mold, it is preferable to use a material with a circular application pattern.
However, in conventional spray guns, even when the air discharge from the corner is stopped, the paint discharge port in the nozzle body and the air discharge port surrounding it remain open toward the front. So, even if the diameter of the paint application opening is relatively large at 2.5 mm,
At a distance of 20 to 30 cm, the circular pattern has a relatively small diameter of 10 cm.

Therefore, as shown in FIG. 4, a blocking plate C is provided via a support piece B extending from the paint discharge port A, and the paint from the paint discharge port E is atomized by the air from the air discharge port D. A type is used in which the particles are scattered around by colliding with the blocking plate C.

[Problem that the invention seeks to solve]

However, in the conventional method shown in Fig. 4, the coating pattern is almost only ring-shaped, and the paint collides with the blocking plate C and is deposited on the blocking plate C. However, it was difficult to maintain a stable coating pattern.

The present invention is equipped with an annular paint discharge port and an air discharge port, and is based on the fact that air is discharged in the form of a cone film that widens toward the tip, allowing for stable spraying of a circular coating pattern. The purpose of this project is to provide a spray gun for round spraying.

[Means for solving problems]

Hereinafter, one embodiment of the means of the present invention that can achieve the above-mentioned objects and solve the problems will be described with reference to the drawings.

In the figure, a round spray gun 1 is provided with a conical air passage 4 and a conical paint passage 5 in a nozzle body 3 attached to the tip of a gun body 2.
is opened to an annular air outlet 6, and the conical paint path 5 is opened to a substantially annular paint outlet 7.

In this embodiment, the gun body 2 is a so-called fully automatic spray gun.

The gun main body 2 includes a case 22 having a notch 21 on the lower surface, and a piston 26, through which the rear end of the needle valve 24 passes through the notch 21, can be slid on the main part 23 of the case 22 at the rear of the notch. air chamber 27
and an on-off valve 29 integral with the piston 26. A guide hole 31 is opened in the air chamber 27 and communicates with a nipple 30 (shown in FIG. 2) at the rear end of the protrusion on the lower surface of the main portion 23, and by feeding operating air into the guide hole 31, the piston 26 back. Therefore, the piston 26 has guide holes 9A and 9B which are connected to the air flow path 9 for blowing air that is connected to the front surface of the gun body 2 from the nipple 32 of the other projection.
A conical opening/closing valve 29 at the tip of the piston 26 conducts. The piston 26 has a gap G between it and the retaining ring at the rear end of the needle valve 24, so that the piston 26 pulls the needle valve 24 with a delay.

Further, in this example, a joint fitting 35 is attached to the neck portion 33 of the case 22 in front of the notch portion 21.

The fitting 35 includes a small diameter portion 39 that surrounds the needle valve 24 and is screwed into a threaded portion concentric with the needle valve 24;
It has a body part 40 that tightly fits into the neck part 33 and a large diameter part 41 that comes into contact with the front surface of the neck part 33, and the large diameter part 41
has external threads engraved on it. Further, the large diameter portion 41 is provided with a vertical hole 42 on the outside in the radial direction.
2 forms a downstream portion of the air flow path 9 of the gun body 2.

Further, the fitting 35 is provided with a guide hole 45 through which the needle valve 24 is inserted and whose front end is open.

The guide hole 45 has a nipple 46 at the lower end of the neck 33.
The guide hole 47 extending from the
forms a paint flow path 10. An insertion hole 51 is provided at the tip of the guide hole 45 via a step 50, and an internal thread is formed inside the step 50.

The nozzle body 3 includes a cap 12 and an inner metal fitting 1.
3 and a tip fitting 14, both of which are formed concentrically with respect to the central axis of the needle valve 24.

The inner metal fitting 13 has an end inserted into the insertion hole 51 and a small diameter portion screwed into the inner thread of the guide hole 45 at the front end of the body portion 53. A conical plate portion 15 is formed.

Further, the inner surface of the conical plate portion 15 is inclined outward at an angle of about 45 to 55 degrees, in this example, about 50 degrees with respect to the central axis. It has a conical shape that increases in diameter towards the tip. Further, a relatively shallow recess 55 is formed along the entire circumference of the inner surface of the conical plate portion 15 . Further, on the inner surface, the body portion 53
A large number of grooves 56 are radially recessed and extend outward beyond the recess 55 from the vicinity of the recess 55 .

Further, the conical plate portion 15 is provided with a stepped hole at its center extending from the outer surface into the body portion 53 and having a large diameter hole 59 and a medium diameter hole 60 arranged concentrically.
forms a valve port 62 that tapers inward through a small hole 61 provided at its center. Note that the needle valve 24 can come into contact with the valve port 62 in its forward state.

Further, the outer surface of the conical plate portion 15 is 65
It forms a slope that slopes outward at an angle range of 85 degrees to 85 degrees, in this example about 75 degrees, and thus is formed into a cone shape whose diameter increases toward the tip.

The cap 12 has an inward flange 69 formed at the outer end of a cylindrical portion 64 that is screwed into the threaded portion at the tip of the large diameter portion 41. On the outer surface of the flange 69, a cone surface 67 having the same inclination as the inner surface of the conical plate section 15 is connected via a chamfered portion and an annular vertical surface 66 perpendicular to the central axis. Further, an inner hole 70 is formed in the flange 69 and extends around the upper portion of the groove portion 56 .

Note that the inner surface 68 of the flange 69 is connected to the large diameter portion 4.
1 and the gap 72, the inner hole 70 and the gap 72 are connected to the air passage 1 which communicates with the air passage 9.
form 6. Further, the vertical surface 66 is connected to the inner fitting 13.
It protrudes a distance L1 forward from the peripheral edge 74 that is connected to the recessed portion 55 of. The distance L1 is set to about 0.3 to 2 mm, in this example about 0.5 mm, and the annular air outlet 6 that goes around the depth of the recess 55 between the peripheral edge 74 and the cone surface 67 Form. In addition, since the cone surface 67 comes into contact with the inner surface of the inner metal fitting 13, it is formed of a groove portion 56 and a concave portion 55, and opens at the air discharge port 6, and increases in diameter toward the tip, thereby creating a thicker cone. The conical air passage 4 is formed which can discharge air in a film-like manner.

The tip fitting 14 has a head 77 at the tip of a screw shaft 67 that is screwed into the small diameter portion 60, and the screw shaft 76 has a hole 79 that opens at its rear end.
At the same time, a side hole 91 that opens at the large diameter portion 59 is bored in the hole 79 . Therefore, the hole 79, the side hole 91, the large diameter hole 59, and the medium diameter hole 60 pass through the small hole 61 and connect to the paint passage 17 which communicates with the paint passage 10.
form.

The head 77 has a spherical front surface and a hexagonal locking hole 92 in the center of the front surface.
A screw hole 93 is formed through the hole.

The inner surface of the head 77 is formed into a cone surface 94 having the same slope as the outer surface of the inner metal fitting 13, and a shallow concave portion 95 is formed in the shape of a ring on the outer periphery. A large number of grooves 97 are radially formed extending from the base of the surface 94 beyond the recess 95.

Therefore, by screwing the tip fitting 14 into the inner fitting 13, the tip fitting 14 is inserted into the inner fitting 13 by the recess 95.
The substantially annular paint discharge port 7 is connected to the outer surface of the
It can be formed concentrically with the air discharge port 6. The conical plate portion 15 has a thin peripheral edge, so that the paint discharge port 7 is located near and outside the air discharge port 6. The groove portion 97 and the recess 95 form the conical coating path 5 which communicates with the coating material discharge port 7 and has a conical shape whose diameter increases toward the tip and is connected to the coating material path 17.

The diameter D1 of the head 77 is set to about 25 to 35 mm, in this example, about 29 to 29.5 mm, and the diameter D2 of the conical plate part 15 is set to about 0.2 to 1.
It is formed to have a large diameter of about mm, in this example, about 0.5 to 1 mm.

[Effect]

Thus, the nipple 30 is connected to an air source for operation via a suitable control device, the nipple 32 is connected to a high pressure air source for blowing air, and the nipple 46 is connected to a paint pumping device.

Furthermore, by supplying operating air to the nipple 30, the on-off valve 29 is opened to allow blowing air to flow into the air flow path 9. The blown air flows through the air passage 16 and the conical air passage 4, and is discharged from the air discharge port 6 in the shape of a tapered cone as described above. Also, as the piston 26 retreats, the needle valve 2
4 opens the valve port 62 to allow the paint to flow into the paint flow path 9, and the paint flowing in a cone shape through the conical paint path 5 is atomized by the air discharged from the air outlet 6 and jetted out. .

In addition, the air flow a mixed with the atomized paint and ejected in the form of a cone film with a ring-shaped cross section and a thick tip, sucks air from the front part of the nozzle body 3 and flows diagonally outward. It flows out in the direction. Therefore, the front part of the nozzle body 3 becomes a negative pressure, and the inner ends of the jet streams having a ring-shaped cross section overlap at the spraying position which is about 20 to 30 cm away from the nozzle body 3. Therefore, it is possible to form a circular coating pattern with a diameter D3 of about 30 to 50 cm, and compared to a conventional spray gun equipped with a coating material discharge port that opens on the central axis, it is possible to form a circular coating pattern with a larger diameter. It is possible to obtain a pattern with

〔Example〕

Note that the round spray gun of the present invention can be used as a hand-held type equipped with a trigger instead of an automatic type spray gun, and a cup-type paint container such as a gravity type can also be directly attached.

Furthermore, for example, the distance L1 between the vertical surface 66 of the cap 12 and the periphery 74 of the inner fitting 13, the diameter D1 of the head 77 and the diameter D2 of the periphery 74, or the inclinations of the conical air passage 4 and the conical coating passage 5 can be changed. By doing so, a coating pattern such as a ring shape can also be formed.

〔Effect of the invention〕

As mentioned above, the round spray gun of the present invention has a conical air passage and a conical paint passage in the nozzle body at the tip of the gun body, and can have a ring-shaped application pattern in addition to a circular application pattern. In addition, the diameter of the blocking plate C can be made larger than that of the conventional one, and unlike the conventional one shown in FIG. 4, there is no collision between the blocking plate C and the paint. Enables stable and efficient spraying without paint build-up on surfaces. Further, the round spray gun of the present invention can be suitably used for spraying various types of mold release materials, anti-corrosion materials, etc. in addition to so-called paints.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the present invention, and FIG.
The figure is a rear view, FIG. 3 is an enlarged sectional view of the nozzle body, and FIG. 4 is a sectional view illustrating the nozzle body of a conventional spray gun. 2... Gun body, 3... Nozzle body, 4... Conical air path, 5... Conical paint path, 6... Air discharge port, 7... Paint discharge port, 9... Air flow path, 10 …
... Paint channel, 12 ... Cap, 13 ... Middle metal fitting, 14 ... Tip metal fitting, 15 ... Conical plate part, 16 ...
...air path, 17...paint path.

Claims (1)

[Scope of Claims] 1. The air passage of a nozzle body, which is attached to the tip of the gun body and has a paint passage and an air passage in which the paint passage and the air passage of the gun body communicate with each other, is connected to the nozzle. The conical air passage opens at an annular air discharge port around the main body and increases in diameter toward the tip, allowing air to be discharged in the form of a thick cone membrane. A round spray gun that communicates with a conical paint path that opens at a paint discharge port that has a substantially annular shape and is concentric with the air discharge port, located near and outside the discharge port. 2. The round spray gun according to claim 1, wherein the conical air passage is inclined at an angle of 45 to 55 degrees with respect to the central axis of the nozzle body. 3. The nozzle body is composed of a cap, an inner fitting, and a tip fitting, and the conical air passage and the conical paint passage are formed on the inner and outer surfaces, respectively, of a conical plate portion with a thin peripheral edge provided in the inner fitting. A round spray gun according to claim 1.