JP4481678B2 - Application nozzle - Google Patents

Description

The present invention relates to a coating nozzle for a coating liquid such as a protective film material . This protective film is intended to cover, for example, an automobile body.

As a countermeasure against damage and acid rain during transportation to a dealer, acid rain, feces, or the shipping environment during a long maritime transportation period at the time of import and export, A flat surface such as a hood or trunk is covered with a protective film called a liquid wrap. The coating film is for a relatively low viscosity coating liquid material, after painting completion of factory, stretching the viscous coating liquid obtained by gravity flow from the nozzle, by drying this formed into a film Is done. However, since the stretching of the coating liquid is performed manually using a roller, the work requires manpower.

  In order to automate this coating film forming operation, it is conceivable to spray a material coating liquid on the vehicle body to be coated, for example, with a spray gun for coating. However, in this case, there is a possibility that the coating liquid misted by the spray gun is scattered and adheres outside the surface range to be coated. For this reason, it becomes difficult to form a single film having a uniform film thickness on the entire flat surface of the vehicle body. Furthermore, the coating film surface formed using the misted coating liquid has a large degree of scattering of the coating liquid especially at the edge portion, and it is difficult to form a boundary line that can be clearly distinguished from the non-coating surface. .

  In order to easily peel the coated film, it is desirable to give the film edge part a certain thickness, but it is not easy to thicken the edge part formed in this way. . Therefore, when a coating film is formed using a spray gun, there is a problem that film peeling cannot be reliably and easily performed when the protective film is detached.

Moreover, although the application nozzle which applies high-viscosity liquids, such as a sealing material, is disclosed by patent document 1, for example, when applying a protective film material using this, rather than the material coating liquid which an application nozzle assumes Due to the low viscosity of the protective film material, various problems are expected to occur.
Japanese Utility Model Publication No. 7-7771 (FIGS. 4 to 6)

  That is, the first aspect of what is disclosed in Patent Document 1 is that the outer shape of the tip of the coating nozzle has a spherical shape, and the inner wall surface corresponding to the end of the blind pipe structure of the supply flow path is formed on the inner side of the tip. By adopting the shape, the thickness of the slits constituting the liquid ejection part is made substantially constant, and the uniformity of the coating pattern is ensured. However, since the connecting portion between the cylindrical base portion and the conical end portion of the blind pipe structure of the supply channel and the inner surface portion at the connecting portion between the truncated cone slope and the top surface of the truncated cone are bent, When a low-viscosity protective film material coating liquid is used, the flow of the coating liquid is not uniform at these bent portions, thereby causing an imbalance in the discharge pressure. As a result, uniform discharge of the coating liquid is hindered, and it is difficult not only to form a coating film with a uniform or desired film thickness on the coated surface, but also bubbles are generated in the coating liquid immediately before discharge. There is a risk of degrading the quality of the coating film.

  In addition, the second aspect of the present invention further improves the stabilization of the wall thickness, which was incomplete in the first aspect, by making both the tip outer shape of the coating nozzle and the inner wall surface inside the tip part spherical. To do. However, even in this case, when a protective film material coating liquid is used, a bent portion remains at the inner surface portion of the connection portion between the cylindrical base portion of the blind pipe structure and the spherical terminal portion of the supply flow path. Uniformity is not ensured, and there is still a risk of bubble formation. Further, since the bent portion remains in the third aspect of this, the concern about the occurrence of these problems remains unresolved as in the first and second aspects.

In view of the above-described problems, the present invention provides a coating nozzle for coating liquid that enables formation of a good coating film having a uniform and desired film thickness distribution, particularly when coating a coating liquid such as a protective film material. It is an issue. Note that the desired film thickness distribution in this case includes, for example, locally generating a constant film thickness change.

In order to solve the above-described problems, the present invention provides an application nozzle for applying a coating liquid on a coating surface so as to have a uniform film thickness distribution. A continuous hollow cylindrical body, a coating liquid supply channel having a blind tube structure in which a hollow shaft core of the cylindrical body is closed inside the tip, and a depth reaching the supply channel from the tip And a discharge tube composed of a straight slit, and a closed end portion of the blind pipe structure of the supply flow path is formed of a hemispherical spherical surface, and the spherical surface of the tip end portion that passes through the deepest straight groove of the slit and the straight groove, and A channel wall surface formed by both spherical surfaces of the hemispherical surface of the closed end portion, wherein the distance between the spherical surfaces of the wall surface is in a range not less than the radius and not more than the diameter of the closed end portion hemisphere. .

According to this, the contact distance of the coating liquid that passes through the slit serving as the discharge port is ensured to be relatively large with respect to the flow path wall surface that is opposed to the slit. And since the directionality of the coating liquid discharge is stabilized by this, even if a relatively low viscosity coating liquid such as a protective film material is used, it is possible to surely form a good coating film having a uniform or desired film thickness distribution. Can do.

This is because the discharge pressure and flow rate of the coating liquid supplied from the coating liquid supply flow path are considered to correlate with the radius of the hemispherical spherical surface forming the closed end of the blind tube structure of the coating liquid supply flow path. In particular, when the coating liquid of relatively low viscosity, such as protective film material, the flow rate is relatively large compared to the high viscosity material such as a sealing material, during coating formation on the coated surface, the direction of the time outside the discharge Has an important impact. That is, when the discharge coating liquid passes through the flow passage wall surface facing through the discharge port , the tip end spherical surface and the closed end hemispherical spherical surface are secured so as to ensure the contact distance between the coating liquid and the flow passage wall surface. By keeping the distance between both spherical surfaces within the range of the radius of the closed-end hemisphere spherical surface and the diameter of the closed end hemispherical surface in any part of the flow path wall surface, the discharge direction of the coating liquid can be converged within a predetermined range, Application of a coating liquid with a reduced diffusion spread is possible.

  Further, a part of the peripheral surface of the cylindrical body includes a pair of symmetrical points at symmetrical positions across the hollow shaft core on the deepest straight groove of the slit, and is parallel to the hollow shaft core and slits. By forming a pair of plane shapes that are orthogonal to the linear direction and reach the tip spherical surface, the film can be formed with a desired film thickness distribution.

This is because, in the vicinity of the deepest straight groove of the slit, the straight slit is cut off by a pair of parallel planes to form a linear outer end, and the distance between the two spherical surfaces on the channel wall surface is from other parts. This is because it becomes relatively small. At this time, at the pair of symmetrical points at symmetrical positions across the hollow shaft core on the deepest straight groove of the slit, the diffusion degree of the coating liquid discharge becomes approximately the same. Then, the discharge coating from these point positions reaches the coating film portion to be formed with a relatively uniform film thickness by the coating liquid discharged through the adjacent portion where the distance between both spherical surfaces is relatively large. The liquid diffuses to form a coating film on the painted surface . At this time, at the end of the coating surface portion to be formed with a uniform film thickness, a coating film is formed in a state where the diffused discharge coating liquid is added, and the coating film formation is performed at the position of the symmetry point. Each is done correspondingly. Thus, it is possible to form a coating film having a desired film thickness distribution in which the bead end is raised on the painted surface.

  Note that the spherical shape of the tip and the hemispherical shape of the closed end of the blind tube structure do not necessarily have the same spherical center as long as they are on the same axis line that matches the hollow axis of the cylindrical body. For example, even when these spherical center positions are different from each other, the deepest straight groove of the slit is symmetrically arranged with the hollow shaft core interposed therebetween. For this reason, the contact distance between the coating liquid discharged through the vicinity of the deepest straight groove and the flow path wall faced through the slit is symmetrically about the same across the hollow shaft core. Also in this case, the linear outer end portion is formed in the linear slit by the pair of parallel planes described above, so that in the vicinity of the slit deepest straight groove, between the two spherical surfaces on the flow path wall surface from the other portions. The distance is relatively small. That is, by performing coating using the coating nozzle for the protective film material having such a shape, for example, it is possible to surely form a coating film having a desired film thickness distribution such that the end of the bead rises on the coating surface. .

  The protective film in the state of covering the vehicle body improves workability by starting the peeling from both ends of the raised bead, so that the entire film can be detached in a single peeling operation. Can be expected.

In the coating nozzle of the present invention, the distance between the spherical surfaces of the tip end spherical surface and the coating liquid supply flow channel closed end hemispherical surface is equal to or larger than the radius of the closed end hemispherical spherical surface in any part of the flow path wall surface. Since the coating liquid discharge directionality is stabilized by being within the following range, even if a relatively low viscosity coating liquid such as a protective film material is used, a uniform coating film having a uniform or desired film thickness distribution is obtained. The certainty when forming is increased.

In addition, it includes a pair of symmetrical points at symmetrical positions across the hollow shaft core on the deepest straight groove of the straight slit, and is parallel to the hollow shaft core and orthogonal to the straight slit, and the tip spherical surface Are formed as a part of the peripheral surface of the cylindrical body, so that the linear outer end is formed in the straight slit, and in the vicinity of the deepest straight groove of the slit, The distance between the two spherical surfaces on the flow path wall surface is relatively smaller than the portion other than the above. As a result, the diffusion degree of coating liquid discharge in the vicinity of the slit deepest straight groove becomes relatively large. Then, the discharged and discharged liquid from the vicinity diffuses to the coating film portion to be formed with a relatively uniform film thickness by the coating liquid discharged through the adjacent portion having a relatively large distance between both spherical surfaces. To form a paint film on the painted surface . Since this is performed corresponding to the positions of the symmetry points, it is possible to form a coating film having a desired film thickness distribution in which both ends of the beads rise on the painted surface.

FIG. 1 is a schematic view showing a first embodiment of the coating nozzle of the present invention. FIG. 1 (a) shows a schematic top view, and FIG. 1 (b) shows a cross-sectional view along line AA in the schematic top view. Show. This application nozzle is for performing airless coating of the supply coating liquid, and includes a tip portion 1 formed of a part of a spherical surface, a cylindrical barrel portion 3 connected to the tip portion 1, and a hollow shaft of the cylindrical barrel portion 3. In a basic configuration including a coating liquid supply channel 2 having a blind tube structure in which the core is closed inside the tip portion 1 and a discharge portion 4 formed of a straight slit having a depth reaching the coating solution supply channel 2 from the tip portion 1. On the other hand, the closed end portion 5 of the coating liquid supply flow path 2 is formed by a hemispherical spherical surface 5a, and the deepest straight grooves 4a and 4b of the discharge portion 4 , and the tip spherical surface 1a and the hemisphere that respectively pass through these linear grooves 4a and 4b. In the flow path wall surfaces 4c and 4d formed by both spherical surfaces of the spherical surface 5a, the distance L between the spherical surfaces 1a and 5a of the wall surfaces 4c and 4d is equal to or greater than the radial distance r of the closed-end hemispherical spherical surface 5a. The configuration is within the range of 2r or less.

  The distance L in this case indicates the shortest length of each arbitrary point position of the tip spherical surface 1a and the hemispherical spherical surface 5a. That is, in FIG. 1B, the lengths between the zenith positions 1b and 5b of the tip spherical surface 1a and the hemispherical spherical surface 5a can be referred to as “distances”. The length between the zenith position 5b is outside the definition of “distance”.

Further, the portion below the straight grooves 4a and 4b of the discharge part 4 is formed as a cylindrical body part 3 of the application nozzle, and the application liquid supply channel 2 connected to the hemispherical spherical surface 5a constituting the closed end part 5 of the blind tube structure is provided. Go. Furthermore, the lower end portion of the body portion 3 is formed with a desorption portion 3a for desorption to a coating liquid supply pipe (not shown) connected to the main application nozzle.

When airless coating is performed with a relatively low viscosity coating liquid made of a protective film material using the coating nozzle shown in FIG. 1, the flow path wall surfaces 4 c and 4 d that are opposed to each other via the discharge unit 4 , and the discharge unit 4 Since a relatively large contact distance with the passing coating liquid is ensured, the direction of discharging the coating liquid is stable, and it is possible to reliably form a good coating film to correspond to a desired film thickness distribution. .

This is because the discharge pressure and flow velocity of the coating liquid supplied from the coating liquid supply flow path 2 are considered to correlate with the radius r of the hemispherical spherical surface 5a of the closed end portion 5 in the blind tube structure of the coating liquid supply flow path 2. It is. In particular, in the case of relatively low viscosity coating liquid, such as protective film material, the flow rate is relatively large compared to the high viscosity material such as a sealing material, the direction in an external discharge for forming a coating film on the coated surface by this Sex has an important impact. When the discharge coating liquid passes through the flow passage wall surfaces 4c and 4d facing each other through the slits constituting the discharge portion 4 , the tip spherical surface 1a and the tip spherical surface 1a corresponding to the contact distance between the coating liquid and the flow passage wall surfaces 4c and 4d By keeping the distance L between the two spherical surfaces of the hemispherical spherical surface 5a within the radius distance r and the diameter distance 2r of the closed end hemispherical spherical surface 5a , the discharge direction of the coating liquid can be converged within a predetermined range. Application of a coating liquid with a reduced degree of diffusion becomes possible. Therefore, by performing airless coating using the coating nozzle having the structure shown in FIG. 1, it is possible to form a good coating film having a uniform film thickness distribution.

By the way, in the coating nozzle shown in FIG. 1, the spherical surface 1a and the hemispherical spherical surface 5a are set to have the same spherical center, and the distance L is made constant at an arbitrary portion of the flow wall surfaces 4c and 4d constituting the slit 4. However, for example, the distance L on the slit 4 can be locally varied by making the spherical center positions of the spherical surface 1a and the hemispherical spherical surface 5a different from each other. As described above, the distance L corresponding to the contact distance between the coating liquid and the flow path wall surfaces 4c and 4d is an increase / decrease factor of the degree of diffusion in the coating liquid discharge direction. It is possible to form a coating film with a film thickness distribution of.

FIG. 2 shows a schematic view of a coating nozzle that enables the formation of a coating film with such a desired film thickness distribution as a second embodiment of the present invention. That is, FIG. 2A shows a schematic top view, and FIG. 2B shows a cross-sectional view taken along the line BB of the schematic top view. A tip portion 1 formed of a part of a spherical surface, a cylindrical barrel portion 3 connected to the tip portion 1, and a coating liquid supply channel 2 having a blind tube structure in which a hollow shaft core of the cylindrical barrel portion 3 is closed inside the tip portion 1. In contrast to the basic configuration including the discharge section 4 formed of a linear slit having a depth reaching the coating liquid supply flow path 2 from the tip section 1, the closed end portion 5 of the coating liquid supply flow path 2 is a hemispherical spherical surface 5a. The flow path wall surfaces 4c and 4d formed by the deepest straight grooves 4a and 4b of the discharge portion 4 and the both spherical surfaces of the tip spherical surface 1a and the hemispherical spherical surface 5a that respectively pass through the linear grooves 4a and 4b. The first point shown in FIG. 1 is that the distance L between the spherical surfaces 1a and 5a of the wall surfaces 4c and 4d is within the range of the radius distance r and the diameter distance 2r of the closed-end hemispherical spherical surface 5a . This is the same as the embodiment.

On the other hand, the difference from the structure of the coating nozzle shown in FIG. 1 is that a part of the peripheral surface of the cylindrical body 3 is formed on the deepest straight grooves 4a and 4b of the discharge part 4 and the core axis of the hollow shaft core of the cylindrical part 3 7 includes a pair of symmetry points 4e and 4f at symmetrical positions, and is parallel to the core shaft 7 and orthogonal to the linear direction of the discharge portion 4 , and is symmetrical on the tip spherical surface 1a. It is a point formed by a pair of parallel planes 6a and 6b reaching points 1e and 1f.

The coating nozzle shown in FIG. 2 can form a good coating film having a desired film thickness distribution. This is because the distance L ′ on the flow path wall surfaces 4c and 4d is smaller in the vicinity of the deepest straight grooves 4a and 4b of the discharge port portion 4 than in other portions.

That is, the diffusion degree of the coating liquid discharge in the vicinity of the deepest straight grooves 4a and 4b of the discharge part 4 is symmetrically about the same. Then, the discharged discharge liquid from the distance L ′ portion diffuses to form a coating film surface up to the coating film portion to be formed with a relatively uniform film thickness with the discharged coating liquid from the distance L portion. . At this time, the coating film is formed in a state where the diffused discharge coating liquid is added at the end of the painted surface portion to be formed with a uniform film thickness. This coating film formation is performed corresponding to each of the above-mentioned symmetric positions, and thus a coating film having a desired film thickness distribution in which the bead end swells on the painted surface can be performed. In particular, the film protective film formed in a shape in which both ends of the bead swell on the painted surface is convenient for removing the entire film in one peeling operation.

  And by performing such application | coating, the coating-film formation which has the desired film thickness distribution that a bead edge part swells on a coating surface, for example can be performed reliably. The protective film in the state of covering the vehicle body improves workability by starting the peeling from both ends of the raised bead, so that the entire film can be detached in a single peeling operation. Can be expected.

The coating nozzle of the present invention can be used as a component of an automated apparatus for reliably forming a coating film such as a desired protective film having a uniform and uniform film thickness distribution.

(A) Schematic top view of the first embodiment application nozzle of the present invention (b) Cross-sectional view taken along line AA shown in FIG. (A) Schematic top view of second embodiment coating nozzle of the present invention (b) Cross-sectional view taken along line BB shown in FIG. 2 (a)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tip part 1a Tip part spherical surface 2 Coating liquid supply flow path 3 Cylindrical trunk | drum 4 Discharge part 4a 4b Deepest straight groove | channel 4c 4d Channel wall surface 4e 4f Symmetry point 5 Closed end part 5a Hemispherical spherical surface 6a 6b Plane 7 Core axis L L ' Distance r Hemispheric radius

Claims (2)

An application nozzle for applying a coating liquid on a painted surface so as to have a uniform film thickness distribution,
A tip composed of a part of a spherical surface;
A hollow cylindrical body continuous to the tip;
A coating liquid supply channel having a blind tube structure in which the hollow shaft core of the cylindrical body is closed inside the tip portion;
A discharge portion comprising a straight slit having a depth reaching the supply flow path from the tip portion,
The closed-end structure of the blind pipe structure of the supply flow path is formed as a hemispherical spherical surface, the deepest straight groove of the slit, the spherical surface of the tip portion that respectively passes through the linear groove, and both spherical surfaces of the hemispherical spherical surface of the closed end portion in the formation and the flow path wall surface, the distance between the two spherical surface of the wall surface, Ri the radius not more than the range in der diameter of the closed end hemisphere,
A part of the circumferential surface of the cylindrical body includes a pair of symmetrical points at symmetrical positions across the hollow shaft core on the deepest straight groove of the slit, and is parallel to the hollow shaft core and the slit. A coating nozzle characterized by a pair of parallel planes perpendicular to the linear direction and reaching the tip spherical surface . Coating nozzle of claim 1 Symbol placement, wherein said coating liquid is a coating liquid of the protective film material.

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