JP5251233B2 - How to paint the cylinder - Google Patents

Description

  The present invention is to form a coating film having a constant film thickness on the inner surface and the outer surface of a cylindrical body, particularly a cylindrical body having a long length and a sectional shape partially changing in the longitudinal direction. The present invention relates to a method for painting a cylinder.

  For example, as shown in FIG. 13, for example, a shaft includes a long cylindrical body 1 having a diameter of about 150 mm and a length of about 3000 mm. Such a shaft has a cross-sectional shape in the longitudinal direction. In some cases, partial uneven portions A are formed on the inner surface and the outer surface, respectively. In such a shaft, a thin coating film having a thickness of 50 to 60 μm is formed on the inner surface and the outer surface, and this coating film is baked after application and integrated with the cylinder. However, in order to maintain the stability of this baking process, there is a strict requirement that the film thickness error of the coating film be within about 30 μm.

  Conventionally, when painting the inner surface of such a shaft, a spray device with a spray gun attached to the tip of a long arm that sprays paint toward the entire circumference is prepared. It was applied by holding the arm and inserting a spray gun into the cylinder. Further, when painting the outer surface of the cylindrical body, the worker has applied it by holding the spray gun by hand.

  As described above, in order to uniformly apply a thin film thickness of 50 to 60 μm, conventionally, an extremely thin coating film of about 10 μm or less is applied 6 to 7 times repeatedly. Since the workers are performing manually, it is difficult to uniformly apply a thin coating film such as 50 to 60 μm, and skill is required for painting. In particular, when the inner surface of the shaft is applied, it cannot be visually confirmed, so it is very difficult for even a skilled worker to perform uniform coating, and the painting operation takes a long time. Was.

  On the other hand, there is a type in which a cylindrical body such as an electrophotographic photosensitive drum is rotated and a nozzle head is moved in parallel with a rotation axis to form a continuous coating film on the outer surface of the cylindrical body (see Patent Document 1).

In addition, a pattern width detection process for detecting the coating pattern width of the coating agent at that time by ejecting the coating agent from the coating gun at a substantially constant discharge flow rate, and comparing the detected coating pattern width with the target pattern width. By providing a distance setting step for setting the distance between the application gun and the workpiece to match both pattern widths based on the width deviation, a predetermined target can be obtained regardless of the temperature change or viscosity change of the coating material. There is one in which a coating material is uniformly applied to a workpiece while being ejected from an application gun with a pattern width (see Patent Document 2).
Japanese Patent Laid-Open No. 04-074570 JP 09-029164 A

  However, Patent Document 1 is applied to a cylindrical body having a uniform outer diameter such as an electrophotographic photosensitive drum, and is a cylindrical body whose cross-sectional shape partially changes in the longitudinal direction as described above. When applied to the surface, the coating film cannot be accurately formed with a constant film thickness on the surface where the shape changes, and Patent Document 2 cannot make the coating pattern width coincide with the target pattern width. However, simply by painting with the target pattern width, when applied to the surface of a cylindrical body whose cross-sectional shape partially changes in the longitudinal direction, such as the shaft described above, a coating film is formed on the surface where the shape changes. There is a problem that the film cannot be formed with a constant film thickness with high accuracy.

  The present invention has been made in view of the above circumstances, and in particular, a coating film having a constant film thickness is accurately applied to the inner surface and the outer surface of a cylindrical body whose sectional shape partially changes in the longitudinal direction, such as a shaft. An object of the present invention is to provide a method of painting a cylinder that can be applied.

The present invention is a cylinder coating method for forming a coating film having a constant film thickness on the inner surface of a cylinder,
A rotation driving means for rotating drivable supported around the axis of the tubular body, the conical inner surface of the moving tubular body at a inner surface and spacing of parallel and cylindrical body the axis of the cylindrical body by the moving means adjusting the spray gun was fixed to the tip of the arm so as to inject the paint, the injection quantity and the spot diameter and the coating amount is applied to the adjustment to the cylindrical body surface injection pressure of the air of the paint from the spray gun And a pressure adjusting means as described above,
Obtain the relative distance between the spray gun and the longitudinal inner surface of the cylinder in advance,
Forming a spiral application pattern by the spot diameter which is applied to the cylindrical body surface to perform the movement of rotation and the spray gun of the tube body by adjusting the injection pressure to be kept constant in accordance with the relative distance At the same time, when the relative distance decreases, the spray gun moving speed increases and the cylinder rotation speed increases . When the relative distance increases, the spray gun movement speed decreases and the cylinder rotation speed increases. By making a decrease ,
Method of coating a cylindrical body and forming a coating film of uniform thickness by and constant pattern interval at a constant application pattern width tubular body surface is intended according to the,.

  Further, in the method of coating the cylindrical body, when a coating film is further formed on the spirally coated coating film, it is preferably applied with a coating pattern whose phase is shifted from the previous coating pattern.

  In the method of painting a cylinder, after a coating film is formed on the surface of the cylinder up to the middle position in the longitudinal direction of the cylinder and the application is stopped, the cylinder is reversed in the longitudinal direction and the stop is applied to the remaining surface. The coating film can be formed up to the connecting portion which is the position.

  In addition, in the method of painting the cylinder, when a coating film is further formed on the coating film formed with the joint portion, the coating film is formed at a position different from the previous joint portion and the coating is stopped. After that, the cylindrical body is inverted in the longitudinal direction, and the coating film is formed on the remaining surface up to the connecting portion which is the current stop position, so that the connecting portion of the coating film does not overlap with the previous time and this time. .

  According to the cylinder coating method of the present invention, the spray pressure is adjusted so that the spot diameter applied to the cylinder surface is always kept constant according to the change in the relative distance between the spray gun and the cylinder surface. In the state, when the relative distance is decreased, the spray gun moving speed and the cylinder rotating speed are increased, and when the relative distance is increasing, the spray gun moving speed and the cylinder rotating speed are decreased. Even if the cross-sectional shape of the cylinder changes, it is possible to achieve an excellent effect that a coating film having a constant film thickness can be formed on the cylinder surface with a constant coating pattern width and the coating patterns wrapped with a constant overlap width.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a side view showing an example of the present invention in the case where a coating film is formed on the inner surface of a cylinder having a shape-changing portion expanding in a cone shape in a part of the cylinder, and FIG. FIG. 1 and 2, reference numeral 1 denotes a cylindrical body having a shape changing portion 2 composed of a cone diameter increasing portion 2 a in a part of a cylindrical longitudinal direction, and 3 denotes a cylindrical body 1 by supporting the cylindrical body 1 by a roller 4, for example. Rotation driving means 5 that is driven to rotate about the axis of the spray gun 5 is a spray gun fixed to the tip of the arm 6 supported by the moving means 12. The moving means 12 includes a moving carriage 8 that moves along a guide rail 7 provided in parallel with the axis of the cylinder 1, and the spray gun 5 supported by the moving means 12 via the arm 6 The mouth 5a moves with a required relative distance L from the inner surface 1a of the cylinder 1.

  A predetermined amount of paint is supplied to the spray gun 5 by a paint supply device 9, and the spray gun 5 is pressurized air set to an arbitrary injection pressure P from the pressure adjusting means 10. As a result, the coating material is sprayed in a conical shape from the spray port 5a of the spray gun 5, and the coating material is applied to the inner surface 1a of the cylinder 1 with a required spot diameter d. It has become.

  FIG. 3 shows an example of the present invention in the case where a coating film is formed on the outer surface 1b of the cylindrical body 1 having the shape changing portion 2 composed of the cone enlarged portion 2a in a part of the longitudinal direction of the cylindrical body 1. FIG. 3 shows a case where the rotation driving means 3 is provided with a rotating jig 11 that is fitted to both ends of the cylinder 1 and is driven to rotate about the axis of the cylinder 1. In this case, the spray gun 5 moves along the guide rail 7 so as to move with a required relative distance L between the spray port 5a of the spray gun 5 and the outer surface 1b of the cylinder 1. It is fixed to the movable carriage 8 via the arm 6.

  4 and 5 show the relationship between the relative distance L between the spray gun 5 and the surfaces 1a and 1b of the cylindrical body 1, the spot diameter d, and the injection pressure P. As the relative distance L increases, the spot is increased. When the diameter d increases and the relative distance L decreases, the spot diameter d decreases. When the injection pressure P increases, the spot diameter d decreases. When the injection pressure P decreases, the spot diameter d increases. ing.

  Next, the operation of the illustrated example will be described.

  In order to coat the cylinder 1 with the apparatus shown in FIGS. 1 and 3, first, the relative distance L between the spray gun 5 and the longitudinal surfaces 1a and 1b of the cylinder 1 is measured. At this time, since there is data at the manufacturing stage regarding the shape and dimensions of the cylinder 1, the position of the gap between the spray gun 5 that moves parallel to the axis of the cylinder 1 and the surfaces 1 a and 1 b based on this data. Is set, the relative distance L can be easily obtained. This relative distance L is input to a control device such as a personal computer (not shown). In the example of FIG. 1, the position of the spray port 5a of the spray gun 5 is made to coincide with the axis of the cylinder 1, but the distance between the spray gun 5 and the surfaces 1a, 1b of the cylinder 1 is the size of the spot diameter d, It can be arbitrarily set in consideration of the turbulence of the air flow during the injection.

  Since the case where the inner surface 1a of the cylindrical body 1 in FIG. 1 is painted and the case where the outer surface 1b of the cylindrical body 1 in FIG. 3 is painted can be applied using exactly the same method, The case of coating the inner surface 1a of the cylinder 1 in FIG. 1 will be described, and the description of the case of coating the outer surface 1b of the cylinder 1 in FIG. 3 will be omitted.

The spray gun 5 is supplied with a certain amount of paint by the paint supply device 9 and is supplied with pressurized air adjusted to the injection pressure P by the pressure adjusting means 10. Is sprayed in a conical shape by pressurized air and applied to the inner surface 1a of the cylindrical body 1 in a spot shape. Here, as shown in FIG. 6, in a flat portion where the relative distance L between the spray gun 5 and the inner surface 1a of the cylinder 1 is constant, the spot diameter d (see FIG. 4) becomes a desired set value. Thus, the injection pressure P of the air supplied to the spray gun 5 is set to a constant set pressure P ₁ . Further, in the cone enlarged portion 2a where the relative distance L between the spray gun 5 and the inner surface 1a is increased, the same diameter as the set spot diameter d is maintained so that the relative distance L increases. Then, the set pressure P ₂ for increasing the spray pressure P of the spray gun 5 is set.

  At the same time, in the flat portion where the relative distance L between the spray gun 5 and the inner surface 1a is constant, the coating pattern 13 with the set spot diameter d maintains a predetermined distance from each other as shown in FIG. The moving speed of the spray gun 5 and the rotational speed of the cylinder 1 are set so that the coating pattern 13 has a set film thickness (wrapped with a constant overlap width a). On the other hand, in the cone enlarged portion 2a where the relative distance L between the spray gun 5 and the inner surface 1a increases, spraying is performed as shown in FIG. 6 so as to maintain the constant overlap width a and to have a set film thickness. Control is performed so that the moving speed of the gun 5 and the rotational speed of the cylinder 1 are decreased according to the relative distance L.

  The relationship between the moving speed of the spray gun 5 and the rotational speed of the cylinder 1 can be set by the following method performed with reference to FIG. In FIG. 8, thick arrows are trajectories indicating the direction of the previous and current coating patterns, Vs is the moving speed of the spray gun 5, Vp is the coating speed at which the spot moves on the inner surface 1a of the cylinder 1, and S1 is the pitch. The period, θ is the pitch angle, d is the spot diameter, and a is the overlapping width of the spot diameters.

ｒ：筒体１の半径
である。 First, in order to make the coating speed Vp constant, the rotational speed of the cylinder 1 is ω.

r: radius of the cylinder 1

Ｓ０＝ｄ−ａ

である。 In order to make the overlap width a of the coating pattern constant,

S0 = da

It is.

となる。 Solving the above equation for the moving speed Vs of the spray gun 5 and the rotational speed ω of the cylinder 1,

It becomes.

  Coating is started with the origin O in FIG. 6 as a starting point, and the spray pressure P and the moving speed of the spray gun 5 are determined based on the relative distance L between the spray gun 5 and the inner surface 1a of the cylindrical body 1 obtained in advance. When Vs and the rotational speed ω of the cylinder 1 are automatically controlled, the application pattern 13 having a constant width is formed on the inner surface 1a of the cylinder 1 with a constant application pattern interval S0 as shown in FIGS. Thus, when the coating pattern 13 is a circle, the coating pattern 13 wraps around each other with a certain overlapping width a, and a spiral coating film having a certain film thickness is formed.

As described above, the injection pressure P is adjusted so that the spot diameter d applied to the inner surface 1a of the cylinder 1 is always kept constant according to the change in the relative distance L between the spray gun 5 and the inner surface 1a. In the state, when the relative distance L is decreased, control is performed to increase the rotational speed of the cylinder 1 at the same time as increasing the moving speed of the spray gun 5.

Further, when the relative distance L is increased, control is performed to decrease the moving speed of the spray gun 5 and at the same time decrease the rotational speed of the cylinder 1.

  As described above, in a state where the spray pressure P is adjusted so that the spot diameter d applied to the inner surface 1a of the cylindrical body 1 is always constant, spraying is performed according to the relative distance L between the spray gun 5 and the inner surface 1a. By controlling the moving speed Vs of the gun 5 and the rotational speed ω of the cylinder 1, the application pattern 13 has a constant application pattern width and a constant application pattern 13 on the inner surface 1 a even if the cross-sectional shape of the cylinder 1 changes. A coating film having a constant film thickness that is wrapped with the overlap width a can be formed with high accuracy.

  At this time, when the coating pattern 13 is an ellipse, the overlapping width a of the coating pattern 13 changes if the coating pattern interval S0 is constant. In this case, the overlapping width a of the coating pattern 13 is The moving speed Vs of the spray gun 5 and the rotational speed ω of the cylinder 1 may be corrected so as to be constant.

  Further, when a coating film is further formed on the coating film formed on the inner surface 1a of the cylindrical body 1 as described above, the phase is shifted with respect to the previous coating pattern 13a as shown in FIG. It is preferable to apply with the application patterns 13b and 13c. FIG. 9 shows a case where the phase is shifted by 1/3 so that two more coating films are formed in one pitch of the coating pattern 13a, and the number of times of shifting the phase is the number of times of repeated coating. It can be arbitrarily set according to. As a method of shifting the phase, it is possible to shift the starting point of the painting work from the origin 0 in FIG.

  As shown in FIG. 10, when a plurality of overcoats are performed with the same phase, a thick portion and a thin portion are generated in the coating film, but the phase is shifted as shown in FIG. By coating the film, the film thickness of the coating film is flattened and a coating film having a constant film thickness can be formed with high accuracy.

  Moreover, although the said form demonstrated the case where the inner surface 1a of the cylinder 1 was coated by one operation over the full length, the inner surface 1a of the cylinder 1 was divided into 2 times in the longitudinal direction of the cylinder 1. It can also be applied. That is, as shown in FIG. 11 (a), after a coating film is formed on the inner surface 1a of the cylinder 1 up to the middle position in the longitudinal direction of the cylinder 1 and the application is stopped, the cylinder 1 is inverted in the longitudinal direction. As shown in FIG. 11B, a coating film is formed on the remaining inner surface 1a up to the connecting portion 14 which is the stop position. It should be noted that the stop of the movement of the spray gun 5 and the stop of the spraying of the paint are controlled so that there is no remaining coating and unnecessary overcoating does not occur at the position where the application is stopped.

  Furthermore, when a coating film is further formed on the coating film having the connecting portion 14 as described above, the coating film is formed to a position different from the previous connecting portion 14 as shown in FIG. After the coating is stopped, the cylinder 1 is reversed in the longitudinal direction, and as shown in FIG. 12B, a coating film is formed on the remaining surface up to the connecting portion 14 ′ which is the current stop position. It is applied so that the joint portion 14 ′ of the coating film does not overlap the previous joint portion 14.

  As described above, when the coating is performed twice in the longitudinal direction of the cylindrical body 1, the length of the arm 6 in FIG. 1 and the moving stroke of the spray gun 5 can be shortened particularly when the inner surface 1a is applied. The painting apparatus can be downsized.

  Note that the present invention is not limited to the above-described embodiment, and can be applied to the coating of various cylinders whose cross-sectional shape is changed in the longitudinal direction other than the shaft, and within the scope not departing from the gist of the present invention. Of course, various changes can be made.

It is a side view which shows an example of this invention in the case of forming a coating film in the inner surface of the cylinder which has the shape change part expanded in cone shape. It is an II-II direction arrow line view of FIG. It is a side view which shows an example of this invention in the case of forming a coating film in the outer surface of the cylinder which has the shape change part expanded in cone shape. It is a side view which shows the relationship between the relative distance of a spray gun and the surface of a cylinder, and a spot diameter. It is a graph which shows the relationship between a relative distance, a spot diameter, and an injection pressure. It is a diagram which shows the principle action | operation of the welding method of this invention. It is the schematic of the helical coating film formed in the inner surface of a cylinder by this invention. It is a conceptual diagram for setting the moving speed of a spray gun and the rotational speed of a cylinder. It is sectional drawing of the coating film by the application pattern apply | coated with the phase shifted with respect to the last application pattern. It is sectional drawing of the coating film by the application pattern apply | coated in the same phase with respect to the last application pattern. (A) is a schematic diagram of a state in which the inner surface of the cylindrical body is applied halfway in the longitudinal direction, and (b) is an overview of a state in which the cylindrical body is inverted in the longitudinal direction and the remaining part of the inner surface is applied to form a joint portion. FIG. (A) is a schematic view of a state in which the coating film formed in FIG. 11 is further applied to a position different from the connecting portion, and (b) is a case where the cylindrical body is reversed in the longitudinal direction and the rest is applied. FIG. 3 is a schematic view of a state where connecting portions are formed at different positions. It is sectional drawing which shows an example of a shaft.

Explanation of symbols

1 cylinder 1a inner surface (surface)
1b Outer surface (surface)
DESCRIPTION OF SYMBOLS 3 Rotation drive means 5 Spray gun 10 Pressure adjustment means 12 Movement means 13 Application pattern 14 Connection part 14 'Connection part A Uneven part L Relative distance P Injection pressure P ₁ setting pressure P ₂ setting pressure a Overlap width d Spot diameter ω Cylindrical body Rotational speed Vs Spray gun moving speed

Claims (4)

A cylinder coating method for forming a coating film having a certain thickness on the inner surface of a cylinder,
A rotation driving means for rotating drivable supported around the axis of the tubular body, the conical inner surface of the moving tubular body at a inner surface and spacing of parallel and cylindrical body the axis of the cylindrical body by the moving means adjusting the spray gun was fixed to the tip of the arm so as to inject the paint, the injection quantity and the spot diameter and the coating amount is applied to the adjustment to the cylindrical body surface injection pressure of the air of the paint from the spray gun And a pressure adjusting means as described above,
Obtain the relative distance between the spray gun and the longitudinal inner surface of the cylinder in advance,
Forming a spiral application pattern by the spot diameter which is applied to the cylindrical body surface to perform the movement of rotation and the spray gun of the tube body by adjusting the injection pressure to be kept constant in accordance with the relative distance At the same time, when the relative distance decreases, the spray gun moving speed increases and the cylinder rotation speed increases . When the relative distance increases, the spray gun movement speed decreases and the cylinder rotation speed increases. By making a decrease ,
Cylindrical body methods paint and forming a coating film of uniform thickness by and constant pattern interval at a constant application pattern width tubular body surface. The cylinder coating method according to claim 1 , wherein when a coating film is further formed on the spirally coated coating film, the coating film is applied with a coating pattern whose phase is shifted from the previous coating pattern. After forming the coating film on the inner surface of the cylinder to the middle position in the longitudinal direction of the cylinder and stopping the coating, the cylinder is reversed in the longitudinal direction, and the coating film is formed on the remaining inner surface up to the connecting portion at the stop position. The cylindrical body coating method according to claim 1 or 2 , wherein: When further coating film is formed on the coating film formed with the joint part, the coating film is formed to a position different from the previous joint part and the application is stopped, and then the cylinder is inverted in the longitudinal direction. 4. The method of painting a cylinder according to claim 3 , wherein a coating film is formed on the remaining inner surface up to the connecting portion at the current stop position so that the connecting portion of the coating film does not overlap with the previous time and this time.

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