JPH0448827Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a powder spray nozzle that sprays a powder coating in the form of a mist in order to coat an object with the powder coating. Specifically, the closed front end of the nozzle body has a substantially cylindrical internal cavity with the rear end open and the front end closed by a hemispherical concave wall, and the rear end is attached and fixed to the front end of a powder coating gun. A powder spray nozzle for powder coating, which has a structure in which a spray opening is provided in the part thereof, and the spray opening communicates with the inner cavity and discharges the airborne powder supplied to the inner cavity through a powder coating gun as a spray. It is related to.

PRIOR ART A powder spray nozzle for powder coating having the above-mentioned structure has an axis line of a cylindrical internal cavity at the closed front end of the nozzle body, as described in Japanese Patent Publication No. 47-26086, for example. Those having elongated, straight (as viewed from the front of the nozzle body) injection openings that intersect and extend in the diametrical direction are widely used.

A conventional powder atomizing nozzle with a diametrically straight spray opening at the closed front end of the nozzle body has an oblong spray pattern and is similar to the known powder atomizing nozzle described in the above-mentioned patent publication. In order to modify the elongated spray pattern, a pin-shaped powder flow deflecting member is provided in the internal cavity of the nozzle body in close proximity to the injection opening to reduce the width of the central part of the elongated ellipse. Conventional powder spray nozzles that have a substantially elongated rectangular spray pattern with a width, and thus have an elongated oval shape or a substantially elongated rectangular spray pattern, can be applied to a flat plate-like object. Although it is suitable for surface painting, it is suitable for simultaneously painting the inner surface of a box-shaped hollow object, where two planes join at an acute angle at or near a right angle, and the surfaces on both sides thereof. If it is not possible to form a uniform coating layer by applying paint to the inner corner of two planes that join at an acute angle, and therefore it is necessary to paint the inner corner of the straight line and the surfaces on both sides of the inner corner, In the case of so-called automatic painting machines that are forced to paint parts of each surface and are driven by a paint gun attached to a reciprocator, it is necessary to install a separate paint machine for each part painting, which increases equipment costs and operating costs. It has the disadvantage of being expensive, and in the case of manual painting in which the painting gun is manually operated and robotic painting in which the painting gun is attached to the operating arm of a robot device and operated automatically, it is necessary to paint each part sequentially over time. However, in both cases, there was a problem in the uniformity of the coating layer as a result of partial coating.

Problems to be Solved by the Invention The purpose of the invention is to simultaneously solve a linear inner corner where two planes join at an acute angle, such as the inner surface of a box-shaped hollow object, and the surfaces on both sides thereof. To provide a powder spray nozzle for powder coating which can form a uniform coating film through a painting operation and can eliminate the above-mentioned drawbacks and problems of conventional powder spray nozzles. That's true.

Means for Solving the Problem In order to achieve the above object, the powder spray nozzle of the present invention has a substantially cylindrical internal cavity whose rear end is open and whose front end is closed by a hemispherical concave wall. a nozzle body whose rear end is attached and fixed to the front end of the powder coating gun, the closed front end of the nozzle body communicating with the internal cavity and having air supplied through the powder coating gun; In a powder spray nozzle provided with an injection opening for discharging floating powder as a spray, the injection opening provided at the closed front end of the nozzle body is located along the axis of the cylindrical internal cavity, and the nozzle Its structural feature is that the main body is formed into a substantially T-shape when viewed from the front.

Effects According to the powder spray nozzle of the present invention having the special structure as described above, the powder spray discharged from the spray opening has a substantially T-shaped spray pattern, and therefore, When painting a straight inner corner where two planes join at an acute angle, the horizontal part of the approximately T-shaped spray pattern "T" is made approximately parallel to the straight inner corner, and the vertical part of the "T" When the powder coating gun, in other words the spray pattern, is moved parallel to the straight inner corner with the part approximately parallel to the plane on one side of the inner corner, the powder spray on the horizontal part At the same time, a uniform powder coating layer is applied to the inner surface of the inner corner and the surface of a predetermined width of the flat surface of the other side, and at the same time, a uniform powder coating layer is applied to the surface of the inner corner of the inner corner with a predetermined width of the flat surface of the other side. Since a uniform powder coating layer is applied to the surface, it is possible to coat the inner corner and both surfaces thereof with a single coating operation, and a uniform coating film is easily formed. .

When painting a recessed corner where three flat surfaces join at approximately right angles, such as the corner of a hollow box-shaped object, the above-mentioned painting operation can be carried out along each of the three straight-line interior corners formed between the flat surfaces, thereby allowing a uniform powder coating to be applied to the recessed corner, each interior corner and a specified width of the surface of each flat surface.

Embodiment Hereinafter, a preferred embodiment of the powder spray nozzle of the present invention will be described with reference to the accompanying drawings.
The powder spray nozzle according to the illustrated embodiment is shown in FIG. 1 (cut side view), FIG. 2 (cut top view), and FIG.
As shown in the figure (front end view), a substantially cylindrical internal cavity 3 with a diameter of about 22 mm was provided, which had an opening 1 at the rear end and was closed at the front end by a hemispherical concave wall 2. For example, the nozzle body 4 is made of a synthetic resin known by the trade name "Teflon" and has a diameter of about 30 mm and a total length of about 50 mm.A closed front end 5 of the nozzle body has a nozzle body 4 that intersects with the axis of the internal cavity 3 when viewed from the front. A horizontal opening 6 with a width of approximately 3 mm extends horizontally in the diametrical direction.
A vertical opening 7 with a width of approximately 3 mm extends vertically from the center of this horizontal opening downward when viewed from the front.
It has a substantially Roman letter "T" shape when viewed from the front, and is provided with an injection opening 8 for discharging powder that communicates with the internal cavity 3.

In the illustrated embodiment, the horizontal opening 6 forming the generally T-shaped injection opening 8 has its outer ends connected to the cylindrical inner wall 9 and the hemispherical concave wall 2 of the generally cylindrical internal cavity 3, respectively, as shown. On the other hand, the outer end of the vertical opening 7 extends to a point approximately 10 mm behind the joint between the cylindrical inner wall 9 and the hemispherical concave wall 2, and terminates therein. Therefore the vertical opening 7
has a total length approximately 10 mm longer than half of the total length of the horizontal opening 6. As will be explained later, this is because the vertical portion of the T-shaped spray pattern of the powder spray sprayed by the powder spray nozzle of the present invention, which is provided with the substantially T-shaped spray opening 8 as described above, extends downward. length greater than the length of its horizontal portion, and if it is desired that the length of the vertical portion of the T-shaped spray pattern be equal to approximately half the length of the horizontal portion, approximately T. The outer ends of the vertical opening 7 of the glyph-shaped injection opening 8, as well as the outer ends of the horizontal opening 6, terminate at the junction of the cylindrical inner wall 9 and the hemispherical concave wall 2 of the internal cavity 3; The vertical opening 7 may have a total length equal to half the total length of the horizontal opening 6.

FIG. 4 is a drawing schematically showing a T-shaped spray pattern obtained by the powder spray nozzle of the present invention having a substantially T-shaped spray opening as described above; Figure b shows the T-shaped spray pattern obtained when the total length of the vertical opening of the shaped injection opening is equal to half the total length of the horizontal opening;
3 shows a T-shaped spray pattern obtained when the total length of the vertical opening of the approximately T-shaped injection opening is made longer than half the total length of the horizontal opening, as in the embodiments shown in FIGS. 1 to 3; Therefore, in order to simultaneously paint the linear inner corner where two planes join at an acute angle and the surfaces of a predetermined width of the planes on both sides in a single coating operation, the spray pattern shown in Fig. 4a is better than the spray pattern shown in Fig. It was found that a T-shaped spray pattern with a long vertical section as shown in Figure b was more suitable.

Figures a and b in Fig. 5 show the formation when a T-shaped spray pattern 10 by the powder spray nozzle of the present invention is used when painting a linear inner corner of, for example, a side panel and a ceiling panel that are joined at a substantially right angle. Powder coating layer 1
1 and a powder coating layer 13 formed when using a known substantially linear spray pattern 12 with a conventional powder spray nozzle, and the arrows in the figure indicate the direction of spraying. , the powder spray nozzles are each moved in a direction parallel to the linear inner corner.

Note that, as can be easily understood from the above explanation, the length of the vertical portion of the T-shaped spray pattern by the powder spray nozzle of the present invention is the approximately T-shaped spray opening provided at the closed front end of the nozzle body. It varies according to the total length of the vertical opening. Therefore,
In the embodiment shown in FIGS. 1 to 3, the other end of the vertical opening 7 of the substantially T-shaped injection opening 8 terminates at a point further rearward than in the illustrated example, and outside the cylindrical portion of the nozzle body 4. By slidably fitting a cylindrical hood into the cylindrical hood and moving the cylindrical hood back and forth to change the end position of the vertical opening 7, the length of the vertical part of the T-shaped spray pattern can be adjusted to the fourth position. It has been recognized that the length can be varied from a length shorter than the vertical portion shown in Figure a to a length more extended than the vertical portion shown in Figure 4b.

In the case of the T-shaped spray pattern 10 produced by the powder spray nozzle of the present invention, as shown in FIG. In the case of a known linear spray pattern 12 produced by a conventional powder spray nozzle, a relatively thick coating layer 13 is deposited only on the inner corner and on the surface immediately adjacent on both sides, as shown in FIG. 5b. Therefore, compared to conventional powder spray nozzles, the powder spray nozzle according to the present invention is extremely superior for painting straight internal corners where two planes join at an acute angle. It will be easily understood.

Effects According to the powder spray nozzle of the present invention having the above configuration, the following useful and outstanding effects can be obtained.

(1) When painting a linear interior corner where two surfaces join at an acute angle, a uniform powder coating layer can be obtained on the interior corner and the surfaces of a predetermined width on both sides.
Even if the amount of powder sprayed is reduced, a uniform coating layer can be formed over a wide area, resulting in a high coating efficiency improvement of about 50 to 80%.

(2) When painting a recessed corner where three surfaces join at an acute angle, a good coating layer can be formed by combining the painting work on a straight inner corner.

(3) In a single painting operation, it is possible to simultaneously paint a linear interior corner and a predetermined width of surface on both sides, so in the case of so-called automatic painting, the number of painting machines that need to be installed can be reduced. In addition, in the case of manual painting and robot painting, the number of man-hours for painting work can be reduced and the painting time can be shortened, resulting in improved work efficiency.

[Brief explanation of the drawing]

Figure 1 of the accompanying drawings is a cut side view showing an embodiment of the powder spray nozzle of the present invention, Figure 2 is a cutaway plan view of the embodiment, and Figure 3 is a front end view of the embodiment. . Figures 4a and 4b are drawings schematically illustrating the T-shaped spray pattern obtained by the powder spray nozzle of the present invention. FIG. 5a schematically shows a powder coating layer formed when a linear inner corner where two planes join at an acute angle is coated using a T-shaped spray pattern using the powder spray nozzle of the present invention. The drawing, FIG. 5b, schematically shows the powder coating layer formed when a similar coating is applied using a linear spray pattern from a conventional powder spray nozzle. In the figure, 1 is the opening of the internal cavity, 2 is the hemispherical concave wall of the internal cavity, 3 is the approximately cylindrical internal cavity, 4 is the nozzle body, 5 is the front end closure of the nozzle body, and 6 is the horizontal opening of the injection opening. , 7 is a vertical opening of the injection opening, 8 is a substantially T-shaped injection opening, 9 is a cylindrical inner wall of the internal cavity, 10 is a T-shaped spray pattern, 11 is a powder coating layer, 12 is a linear spray pattern, 13 indicate the powder coating layer, respectively.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A vehicle having a substantially cylindrical internal cavity whose rear end is open and whose front end is closed by a hemispherical concave wall, and whose rear end is connected to the front end of a powder coating gun. a nozzle body mounted and fixed thereon, the closed front end of the nozzle body having an injection opening communicating with the internal cavity and discharging as a spray airborne powder supplied to the internal cavity through a powder coating gun; A powder spray nozzle is provided, wherein the injection opening provided at the closed front end of the nozzle body is located on the axis of the cylindrical internal cavity and is approximately T-shaped when viewed from the front of the nozzle body. A powder spray nozzle having a shape of: (2) The approximately T-shaped injection opening provided at the closed front end of the nozzle body has a vertical opening that extends downward from approximately the center of the horizontal opening at approximately right angles to the horizontal, and is approximately half the total length of the horizontal opening. The powder spray nozzle according to claim (1) of the utility model registration, wherein the powder spray nozzle is formed to have an overall length greater than the total length of the powder spray nozzle.