JPS587347B2 - airless airless - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an airless spraying device that sprays a liquid to be sprayed under relatively high pressure.

There are many types of airless spraying equipment currently in use, but among them, the spraying equipment used for painting leather surfaces with high viscosity paints, such as leather lacquer clear, is capable of turning high viscosity paints into even fine particles. It is necessary to atomize, but conventional equipment is not fully satisfactory.
In particular, no suitable spraying device was found for use in the finishing of leather.

In airless atomizers, it is generally believed that creating reverse flow, vortex flow, turbulence, etc. in the liquid just before it is supplied to the nozzle is useful for improving the atomization effect, and the present invention Focusing on these causes and effects, the liquid to be sprayed immediately before being supplied to the orifice-type nozzle is reversed by the ejector and the suction action of the liquid to be sprayed that flows through the ejector, and is actively circulated while generating a vortex flow. The present invention is characterized by being able to effectively atomize the liquid regardless of its viscosity, and the embodiment shown in the accompanying drawings will be described in detail below.

The illustrated embodiment has a dome-shaped recess 2 at the tip of the nozzle body 1.
This figure shows an example of a flat blow nozzle having a lip-shaped orifice-type nozzle 4 formed by intersecting with a V-shaped groove 3, and the nozzle body 1 has, for example, as shown in the figure.
In addition to a conical expansion chamber 5 and a cylindrical expansion chamber 6 continuous to the conical expansion chamber 5 at the rear of the dome-shaped concave cavity 2, it is formed in a width shape with a flange 7 on the outer periphery of the rear end, and apart from this, there is a conical expansion chamber 5 at the front end of the center part. An ejector member 10 having a circular protrusion 8 having a smaller diameter than the cylindrical enlarged chamber 6 and a collar 9 at the rear end is prepared, and a relatively small diameter passage is provided at the center of the protrusion 8 in the ejector member. In addition to providing the liquid hole 11, relatively large-diameter liquid passages 12 are provided in the rear portion along a common axis relationship, and around the liquid passage hole 11, there are liquid passages 12 with a smaller diameter than this liquid passage hole. A plurality of liquid guide holes 13 are provided radially to constitute an ejector in the protrusion 8,
Such an ejector member 10 is press-fitted together at the respective flanges 7 and 9 with the front end protruding portion 8 of the ejector member 10 attached so as to protrude from the rear of the nozzle body 1 into the cylindrical enlarged chamber 6 in a common axis relationship. In the process of supplying the liquid to be sprayed from the rear of the ejector member 10 and ejecting it in a fan shape from the spout 4 at the tip of the nozzle, the ejector member 10 is inserted and fixed into the holder 14 as shown in FIG. room 6
Through the action of the ejector, a part of the liquid filled in the inside is sucked inward from the outer circumference with the intervention of the liquid introducing hole 13 and is returned to the liquid passing hole 11, whereby the liquid passing hole 11 and the enlarged chamber are 5. Not only is a circulating flow actively generated across the expansion chamber 6 and the liquid introduction hole 13, but also a small vortex flow accompanying this flow is generated, thereby significantly promoting the atomization effect.

The diameter of the dome-shaped recess 2 in the nozzle is 0.35 m.
m, the diameter of the liquid passage hole 11 was set to 0.4 mm, and therefore the ratio of the opening area of the nozzle 4 to the cross-sectional area of the liquid passage hole 11 was selected to be 1:4, and the high viscosity lacquer clear was 80 kg/
As a result of supplying it under a liquid pressure of cm2 for finishing coating on leather, a beautiful painted surface that could not be obtained with conventional airless spraying equipment was obtained, and as a result of carrying out various experiments regarding the above area ratio. Good results were obtained despite extensive changes, not limited to 1:4.

In addition to the above, it goes without saying that the liquid passage hole 11 in the ejector may be formed in a venturi type.

As explained above, in the present invention, the liquid just before reaching the orifice type nozzle is supplied to the nozzle while being actively formed with a circulating flow by the ejector, so that reversal flow, vortex flow, etc. can be easily prevented. This effectively improves the atomization effect, thus not only preventing the occurrence of tails and spits even in the case of high viscosity paints, but also easily achieving a uniformly distributed spray. It is possible.

[Brief explanation of the drawing]

The drawings show a spraying device of the present invention in one embodiment, in which FIG. 1 is a longitudinal sectional side view, and FIG. 2 is an enlarged longitudinal sectional end view taken along the line (■--■) in FIG. 1... Nozzle body, 4... Spout, 5...
...Enlargement room, 6...Enlargement room, 8...
...Circular protrusion, 10...Ejector part, 1
1...Liquid passage hole, 12...Liquid passage, 13
・・・・・・Liquid introduction hole.

Claims (1)

[Claims] In addition to providing an orifice-type spout at the tip, an expansion chamber is provided behind the nozzle, and an ejector is installed at the rear of the expansion chamber so that the liquid in the expansion chamber is sucked and circulated between the ejector and the expansion chamber. An airless spray device characterized in that it is arranged so that a.