JPH0247271B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pattern painting method and a masking jig for painting, and particularly to a method of pattern painting an object to be painted such as a resin bumper, and a masking jig used in this painting.

Recently, automobile bumpers have been shifting from metal bumpers to resin ones, but painting is a more advanced method of adding color than the method of directly mixing pigments into the bumper material resin. Since it is possible to obtain a beautiful appearance, the method of painting is being intensively studied.

For example, when painting a bumper made of synthetic resin, a so-called pattern painting method is being considered, in which the bumper is painted in different colors along its longitudinal direction.

However, a masking jig is used as a pattern coating for the levers that is suitable for mass production lines, and the following two methods are available. In other words, the first method is to attach a masking jig to the non-painted surface using a clamping means or the like to prevent the paint from adhering to the non-painted surface, and after painting, remove the masking jig, and then attach the masking jig to the object to be coated. This is a method of curing the paint film by putting it in a drying oven, but the boundary line between the painted surface and the non-painted surface (so-called parting line) is easily disturbed by the flow or dripping of the paint film in the early stage of drying in the drying oven. There is a drawback. The second method is to pass the masking jig attached to the object to be coated through a drying oven, but in this case, if the object to be coated is made of synthetic resin, the expansion and contraction of the synthetic resin is large, and Since the manner of expansion and contraction differs depending on the location of the object, even if the masking jig is molded from synthetic resin, the contact surface of the masking jig against the object to be coated will shift in the drying oven, and this will disrupt the parting line. There are drawbacks.

An object of the present invention is to eliminate the above-mentioned drawbacks, and the first aspect of the invention is characterized by having an outer edge that matches the non-painted area of the object to be painted, thereby increasing the temperature of the object to be painted. A flexible jig that can follow the expansion and contraction is prepared, and the masking jig is applied to the non-coated area of the object to be coated and adsorbed, and while this adsorption is maintained, the coating film formation process and heating drying process are carried out. The second invention is characterized by a pattern coating method comprising removing the masking jig after carrying out one or more times, and the second invention is characterized by:
It has a top surface part and a peripheral wall part, at least the peripheral wall part is made of a material that can follow the expansion and contraction of the object to be painted, the outer periphery of the peripheral edge part is formed so as to match the parting line of the object to be painted, and the top surface part The masking jig is provided with a valve that communicates with the space formed by the mask and the peripheral wall and is connectable to a vacuum source.

An embodiment of the present invention will be described below with reference to the drawings.

The masking jig, which is the second invention, which is directly installed and used in carrying out the pattern painting method, which is the first invention, will be explained, and then the pattern painting method will be explained. Fig. 1 is an overall perspective view of a masking jig 10 according to the second invention, Fig. 2 is a sectional view taken along the line - shown in Fig. 1, and Fig. 3 is a synthetic resin bumper as an object to be coated. It is an explanatory view showing a painted surface and a non-painted surface.

In FIGS. 1 to 3, 1 is a synthetic resin bumper, and the non-painted surface 2 of the bumper 1 is the bottom surface of the recess 3 of the bumper 1 (FIGS. 1 and 2). The area A indicated by diagonal lines corresponds to the non-painted surface 2. Painted surface 4 is the surface of the bumper other than the non-painted surface 2, and 5 is the surface of the bumper other than the non-painted surface 2.
Boundary line between and painted surface 4 (hereinafter referred to as parting line)
In FIG. 3, this corresponds to the outer periphery of the shaded area A. The masking jig 10 is formed by a jig body 11 so as to mask an area A (FIG. 3) extending from the parting line 5 to the entire area of the non-painted surface 2. Area B included in A (area within the two-dot chain line C in Figure 3)
A recess 13 formed to open at the recess 13 and a contact that contacts the non-painted surface of the bumper 1 extending from the periphery 13a of the recess 13 (corresponding to the two-dot chain line C in FIG. 3) to the parting line 5. A seal portion 12 extending from the surface 12a and forming a peripheral wall portion of the recess is provided. This jig main body 11 needs to be formed using a flexible material that can follow the expansion and contraction of the bumper 1 when the bumper 1 is coated as described later and the coating is thermally cured, for example. bumper 1
The jig body 1 is made of a synthetic resin that is softer and more elastic than the synthetic resin that is the material of the
When the contact surface 12a of No. 1 comes into contact with the bumper, it comes into contact with a predetermined elasticity.

Therefore, if the inside of the recess 13 is brought into a negative pressure state, the contact surface 12a of the seal portion 12 will contact the bumper 1.
This will mask the non-painted surface 2.

In order to create this negative pressure state, a communication pipe 15 with one end opening into the recess 13 is buried in the jig main body 11, and an on-off valve 16 is provided in this communication pipe 15, and a valve connected to the vacuum pump P is connected to the other end. The flexible hose 17 is connected to an end portion 17a (for example, the female side of the quick joint) and connected to a quick joint 18 that can be disconnected from the flexible hose 17 to form a conduit 19 as a whole.
Then, as described above, the recess 1 is placed in the jig main body 11.
3, the seal portion 12, and the pipe as a whole constitute a masking jig 10. Furthermore, as shown in FIG. 4, a plurality of partition walls 12b and 12c are provided in the recess 13, both ends of which are continuous with the peripheral wall of the seal part 12, and which extend to intersect with each other in the vertical and horizontal directions. By reinforcing the masking jig 10, handling such as attaching and detaching the masking jig 10 to the bumper 1 becomes easier.

In this case, if the negative pressure reservoir 21 is formed, negative pressure can be applied gently throughout the entire interior of the recess 13.

Next, the embodiment of the first invention will be described together with the operation of the embodiment of the second invention. The outer periphery of the contact surface 12a of the seal portion 12 is connected to the resin bumper 1.
Connect the end portion 17a of the flexible hose 17 to the quick joint 18 in a state that it is in contact with the non-painted surface 2 so as to overlap the parting line 5 of to drive. By this driving, the air in the recess 13 of the jig main body 11 is sucked, and the contact surface 12a of the seal portion 12 comes into close contact with the non-painted surface 2 of the resin bumper. In this state, on-off valve 1
6 is closed, the vacuum pump P is stopped, and the flexible hose 17 is removed by operating the quick joint 13, so that the masking jig 10 is attached to the resin bumper 1.

For example, spray primer paint onto this masked resin bumper 1 to form a coating P (Fig. 4).
is formed, and after the coating film is flashed, it is placed in an oven and baked. However, even if the resin bumper 1 that has thermally expanded in this oven comes out of the oven and contracts, the masking jig 10 will not allow the sealing part 12 to close. Since it is flexible and is in close contact with negative pressure, it deforms following this contraction, and the initial close contact position does not change, so the parting line 5 can be maintained accurately.

Therefore, if the intermediate coat or top coat is sprayed with the masking jig attached after baking the primer coat, it will adhere to the primer coat in a layered state and the intermediate coat or top coat C will become the fourth layer. As shown in the figure, it is formed to have a substantially uniform thickness.

When the prescribed painting process is completed in this way,
By opening the on-off valve 16 and letting the atmosphere into the recess 13, the masking jig 10 can be easily removed, and the end surface S of the undercoat P and, for example, the topcoat C can be straightened as shown in FIG. Since so-called sag does not occur, a clear parting line 5 can be obtained. If the top surface of the jig main body 11 is reinforced with a rigid material, the entire jig can be reinforced without losing the elasticity of the seal portion 12, making handling easier.

As is clear from the above description, according to the first invention, a flexible material having an outer edge matching the non-painted area of the object to be coated and capable of following the thermal expansion and contraction of the object to be coated is used. Prepare a masking jig made using the masking jig, apply the masking jig to the non-coated area of the object to be coated, make it adsorb, and while maintaining this adhesion, perform the coating film forming process and heating drying process in 1 step. Since the masking jig is removed after carrying out the masking process a plurality of times, and according to the second invention, the masking jig has a top surface portion and a peripheral wall portion, and at least the outer peripheral edge of the peripheral wall portion is aligned with the parting line of the object to be coated. The masking jig is formed such that the masking jig is formed such that the masking jig and the object to be coated are attracted to each other, and is provided with a valve which is connected to a vacuum source by communicating with the space formed by the top surface and the peripheral wall. Because we were able to provide
Even if the object to be coated passes through a drying oven with the masking jig still attached after the specified coating is completed, the seal portion follows the expansion and contraction of the object, and the adsorption between the masking jig and the object causes Since we were able to ensure close contact, it was possible to eliminate the slippage of the contact surface of the seal part with the object to be coated. This has the great effect of making it possible to finish the boundary line (so-called parting line) between the painted surface and the surface to be painted accurately and clearly even if the difference varies considerably depending on the part of the object to be painted.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing an example of a masking jig according to the present invention, and Fig. 2 is a - of Fig. 1.
3 is an explanatory diagram showing the painted surface and non-painted surface of the synthetic resin bumper that is the object to be painted;
FIG. 4 is a sectional view showing another embodiment of the present invention, and FIG. 5 is an explanatory sectional view of the main part of the bumper after painting using the same masking jig. 1... Resin bumper, P... Primer coating film,
C...Top coat film, S...End face, 2...Bumper 1
Non-painted surface, 4...Painted surface, 5...Border line, 10
...Masking jig, 11...Jig body, 12...
...Seal portion, 12a...Contact surface, 13...Recess,
15...Communication pipe, 17...Flexible hose, 18...
Quick joint, P... Negative pressure source.

Claims (1)

[Claims] 1. A masking jig made of a flexible material that has an outer edge that matches the non-painted area of the object to be coated and can follow the thermal expansion and contraction of the object to be coated is prepared, and an outer masking jig is prepared. The jig is applied to the non-coated area of the object to be coated and adsorbed, and the coating film forming step and heating drying step are performed one or more times while maintaining this adsorption, and then the masking jig is removed. A pattern painting method characterized by removal. 2. It has a top surface part and a peripheral wall part, and at least the peripheral wall part is made of a flexible material that can follow the expansion and contraction of the object to be coated, and the outer periphery of the peripheral wall part is formed so as to match the parting line of the object to be coated. Further, a masking jig characterized in that a valve is provided that communicates with the space formed by the top surface portion and the peripheral wall portion and is connectable to a vacuum source.