JPS6082158A - Air-less spray nozzle - Google Patents

Abstract

PURPOSE:To atomize satisfactorily a high-viscosity liquid over the entire part of an ejection pattern by disposing approximately concentrically a bar-shaped flow regulating body into the guide hole of a nozzle tip in proximity to the inside wall of the hole. CONSTITUTION:A flow regulating body 7 is radially formed at an equal angular space with three projecting pieces 9 to the rear end of a bar-shaped main body 8 which is tapered convergently and has the top end face made into a spherical shape. A guide projection 10 made into a circular conical shape is formed to the center of the rear end face. A nozzle tip 1 is fitted to the stepped hole 12 provided to a body 11 so as to penetrate the center thereof and a collar 2 is pressed to the stopped surface. The pieces 9 are fitted to the expanding step part 15 at the top end of the central hole 14 of a cylindrical holder 13, by which the body 7 is attached to a holder 13. Then the liquid admitted into the guide hole is pressed to the wall surface by the presence of the flow regulating body and is accelerated uniformly and therefore the speed from the ejecting port having a slender shape is made approximately equal at both ends and center satisfactorily by which tailing is prevented and is atomized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an airless spray nozzle that pressurizes liquid such as liquid paint to high pressure and sprays it at high speed from a small jet port to atomize it by friction between the air and the air.
The present invention relates to a nozzle in which the liquid to be jetted is atomized well over the entire jetting pattern.

In airless spray painting, in order to efficiently form a uniform coating film, a long and narrow linear jet is formed at the tip of the nozzle tip to spray the liquid paint in a thin film, which is then atomized by friction with the air. Generally, the ejection port is spread out in a fan shape to reach the object to be coated, but both ends of the elongated ejection port in the length direction are close to the inner wall surfaces on both sides and have a large resistance.

Since the ejection speed is lower than that in the center, atomization is insufficient, and coarse side streams called tails are generated on both sides of the well-atomized main flow in the center, which can damage the surface to be coated. There was a drawback to it. For this reason, a method was proposed in which a small-diameter orifice was provided at the rear of the nozzle tip to equalize the flow velocity of the paint inside the nozzle tip, but this increased flow resistance and reduced jetting pressure, resulting in a decrease in viscosity. Except for particularly low-quality paints, atomization was actually hindered.

It is an object of the present invention to provide a nozzle that eliminates such drawbacks and is capable of atomizing even highly viscous liquid well over the entire spray pattern.

Below, an example in which the present invention is applied to a painting nozzle is attached.
The explanation will be based on the drawings.

In the first embodiment of the present invention shown in FIGS. 1 to 3,
The nozzle tip 1 is made of a hard material such as cemented carbide or ceramic, and has a flange 2 formed on the outer periphery of the rear end, and a tapered conical part 3 in the center of the rear surface and a small diameter part connected to the tip. A guide hole 5 consisting of 4 is recessed near the tip,
By forming a V-shaped cut groove reaching the small diameter portion 4 on the tip surface, a row-shaped elongated jet nozzle 6 is opened, as shown in FIG. As shown in FIG. 3, the flow regulator 7 has three projecting pieces 9 radially formed at equal angular intervals on the rear end of a rod-shaped main body 8 with a tapered end and a spherical tip surface. , a conical guide protrusion 10 is formed in the center of the rear end surface, and a stepped hole 12 is formed transparently in the center of the body 11.
At the same time, the nozzle tip 1 is fitted into the cylindrical boulder 13, and the flange 2 is brought into contact with the stepped surface.The projecting piece 9 is fitted into the enlarged diameter stepped portion 15 formed at the tip of the center hole 14 of the cylindrical boulder 13, and the flow regulator 7 is fitted. By attaching it to the holder 13 and screwing the male thread 16 formed on its outer periphery to the female thread 17 formed on the body 11, the nozzle tip 1 and the fluid regulator 7 are tightened and fixed between the body 11 and the holder 13, and the fluid regulator is fixed. The main body 8 of 7 is located concentrically within the guide hole 5 of the nozzle tip l, and its tip end is connected to the conical part 3
The center hole 14 of the holder 13 is connected to the paint pumping path 20 by screwing into the gun body 19 a hub nut 18 hooked on a collar protruding from the outer periphery of the rear end of the body 11. They are aligned and attached to the tip of the gun body 19.

In this embodiment, the liquid paint pressurized to high pressure by the paint pump is supplied from the paint pressure passage 20 to the center hole 14 of the holder 13 by opening an on-off valve (not shown), and the liquid paint is supplied to the center hole 14 of the holder 13 to guide the rear end of the fluid regulator 7. It spreads in the radial direction along the protrusion 10 and flows into the guide hole 5 of the nozzle tip through three gaps formed between the protrusions 9.
Since the main body 8 of the fluid regulator 7 is arranged concentrically and its tip is close to the inner wall surface, the liquid paint is pressed against the inner wall surface of the conical part 3 and is accelerated evenly over the entire circumference, and reaches the small diameter part 4. Inflow. Therefore, the liquid paint is distributed at approximately the same level at both ends and at the center of the elongated ejection port 6 in the longitudinal direction.
It is ejected as a thin film at a high speed, and due to friction with the air, fine particles are spread over the entire width and spread in a fan shape to reach the object to be coated.

Next, a second embodiment of the present invention will be described based on FIGS. 4 and 5. In this embodiment, as shown in FIG. The structure is the same as that of the first embodiment, except that a rod-shaped flow regulator 27 is integrally protruded, and three through holes 29 connected to the center hole 14 are formed at equal angular intervals around the rod-shaped flow regulator 27. Although the function is the same, since the adjustment plate 27 is integrated with the holder 23, there is an advantage that assembly and measuring operations are facilitated.

Note that the present invention can also be applied to spraying liquids other than paint.

As specifically explained in the embodiments described in Section 11-1, the air spray nozzle of the present invention has an elongated jet nozzle formed at the tip, and a tapered guide hole reaching the jet 1 at the rear surface. The gist is that a rod-shaped flow regulator is disposed approximately concentrically within the guide hole of the nozzle tip formed in the guide hole, the tip of which is located close to the inner wall of the guide hole. Because the liquid flowing into the hole is pressed against the wall surface and accelerated uniformly due to the presence of the flow regulator, the velocity when ejecting from the elongated ejection port is approximately equal at both ends and the center, which prevents the formation of tails. This has the effect of preventing this and achieving good atomization over the entire width.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention. Figure 1 is a cross-sectional view, Figure 2 is an enlarged front view of the nozzle tip,
FIG. 3 is a perspective view of a fluid regulator, FIGS. 4 and 5 show a second embodiment of the present invention, FIG. 4 is a sectional view, and FIG. 5 is a partially cutaway perspective view of a holder equipped with a fluid regulator. It is a diagram. I: Nozzle tip 3: Conical part 4: Small diameter part 5: Guide hole 6: Spout port 7.27: Fluid regulator 8: Main body 19: Gun body 2Q: @Needle pressure feed path Applicant Asahi Okuma Sangyo Co., Ltd. Agent Patent attorney Hiroo Noguchi 1 Ikuo 2 illustrations ■ 3 illustrations Rei 4pi

Claims (1)

[Claims] A nozzle chip having an elongated jet nozzle formed at the tip and a tapered guide hole reaching the jet nozzle formed at the rear surface, and located within the guide hole such that at least the tip is close to the inner wall of the guide hole. An airless spray nozzle characterized by rod-shaped flow regulators arranged approximately concentrically.