JPH0513644U - Masking pad - Google Patents

Abstract

(57) [Summary] [Purpose] Heat resistance and elasticity in masking means that covers non-application areas such as skirting boards protruding from shell cores made of shell sand for casting To provide a masking pad formed by using a silicone rubber having excellent properties such as flexibility as a constituent material. [Structure] A female mold matching the mold is used as a reference on the basis of a mold conforming to the shape of a non-coated part such as a skirting board projecting from a shell core made of shell sand It is formed of silicon rubber that is formed and can be inserted into and removed from the non-coated portion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a masking pad for masking a non-coated portion in the work of coating a casting shell core with a coating agent.

[0002]

[Prior Art]

 As a first example of the conventional part of the casting shell core to which the mold coating agent is applied, a brush is used to form the coating part by hand coating, but as a second example, When the child is placed in the coating bath and applied, the coating part can be placed in the coating bath leaving the uncoated part, or the coating part can be applied by means of a shower system, which is not possible with the shower system. Sufficient remaining part is formed by brushing, or as a third example, the non-coated part is covered with a cover material such as wood or resin and put in a coating tank, or by a shower method. As a fourth example, the non-coated portion is masked with an adhesive tape or the like, put in a coating bath, or formed by a shower method.

Various problems are inherent in the coating portion of the mold coating agent shown in the above-mentioned first to fourth examples. In the first example, the coating agent is brushed on the shell core. However, the second example requires a lot of man-hours, although the number of man-hours required for brush painting is slightly reduced in the second example compared to the first example. For example, when a shell core is placed in a mold bath, depending on the shape of the parts, if the uncoated part of the core is located at the top, most of the coated part will be coated by the mold bath. Although it requires only a small amount of brush coating, it has the drawback that it requires a large number of brush coating steps because it cannot be fully inserted into the mold bath when it is located below.

In the third example, when covering with a cover material such as wood or resin, since the material is not elastic, a gap is created between the core of the non-applied portion and the cover material made of the material. There is a drawback that the voids are impregnated with a coating agent, which impairs the masking effect.

In the fourth example, although it depends on the strength of the pressure-sensitive adhesive tape, masking is performed in a high heat type mold agent, so that there is a drawback that the adhesive paste of the pressure-sensitive adhesive tape is melted and impregnated in the mold type agent. Further, there is a problem that the shell core is damaged when the adhesive tape is attached.

[0006]

[Problems to be solved by the device]

 In the conventional means for forming the non-coated portion such as the baseboard portion of the shell core described above, in view of various inherent defects, in order to perform efficient coating work, first, in the coating tank, It is a cover material for the non-coated part that does not change even in masking work under high heat, and it is highly flexible so that it does not damage the core, and it is also abrasion resistant and highly elastic. In order to provide a masking pad that is made of a material that can be repeatedly used, the masking work can be performed easily even with a complicated core shape, the quality is stable, and the number of steps can be reduced. There is.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, according to the present invention, a female mold that matches the shape of a non-coated portion such as a skirting board portion in a shell core made of shell sand for casting is formed in the inner cavity. The masking pad is made of silicone rubber that can be inserted into and removed from the coated part.

[0008]

[Action]

 The present invention has the above-mentioned structure, and since the masking pad is made of a silicone rubber and is highly flexible and elastic, it is possible to damage the core with respect to the non-coated portion. It has good workability because it can be easily inserted and removed without heat, and because it has excellent heat resistance, it can be used even in the coating process of the coating agent under high heat in the coating tank of the main part of the shell core with the masking pad inserted. Since the material of the pad does not change and the shape can be maintained, if the pad is removed after drying, the non-coated part of the skirting board part will be removed and a shell core with a coating agent applied to the other coated part will be obtained. It is possible to reduce the number of coating agent coating steps.

Further, even if the shape of the non-application portion of the coating agent is complicated, a masking pad that adheres to the core is formed due to the characteristics of the silicone rubber, and a void is formed between the pad and the core. Since it does not occur, the core is not impregnated into the mold coating agent through the voids, a reliable masking effect is achieved, and it has good releasability, and it can be used repeatedly due to its synergistic effect with elasticity. The effect of masking is that the quality is stable and effective masking action is obtained.

[0010]

【Example】

 1 to 5 show an embodiment of the present invention. FIG. 1 shows a masking pad 1, which is made of silicone rubber and is the main body of the shell core 2 shown in FIG. Matches the shape of the non-coated portion 3 that is a baseboard portion protruding from the portion 10. The prototype 7 of FIG. 3 described later is a male mold, and the female mold 4 that can be inserted into and removed from the male mold is an internal cavity. The outer shape of the bottomed outer peripheral portion 8 whose end is the bottom 5 is formed as an outer shell, and the thickness t is set to about 5 mm or 10 mm, so that the shape of the female mold 4 is maintained.

The masking pad 1 is formed by the following processing means.

First, the masking pad prototype 7 shown in FIG. 3 is provided with the outer shape of only the non-application portion 3 which is a skirting board projecting from the side surface of the main body portion 10 of the shell core 2 shown in FIG. To do.

Next, oil clay is applied to the prototype 7 to a thickness of about 0.3 to 0.5 mm to fill the joints and smooth the surface.

As shown in FIG. 4, the prototype 7 is made of wood, veneer board, thick cardboard, or the like, and the thickness of the pad 1 is different from that of the prototype 7 when the masking pad 1 described later is manufactured. It is placed in a frame 6 having a size such that t can be maintained at about 5 mm to 10 mm and having a bottom.

Next, the silicone rubber liquid material for the masking pad and the curing agent are weighed and mixed in another container.

The mixed silicon-based rubber liquid material is poured into the frame 6 on which the prototype 7 is placed. The injection amount is such that the bottom part can be formed on the masking pad 1 when the master 7 is entirely covered and the frame is opened.

Since bubbles are generated when the silicone rubber liquid and the curing agent are mixed or when the mixed liquid is injected into the frame 6, the frame 6 is illustrated immediately after being injected into the frame 6. Although omitted, put it in a decompression container prepared in advance and degas with a vacuum pump.

The silicone rubber liquid injected into the frame 6 is hardened to the most effective state when left at room temperature for 5 to 8 hours.

Then, after the silicone rubber liquid is cured, the frame is unframed and the cured silicone rubber is taken out. As shown in FIG. 1, a female member having a shape suitable for the uncoated portion 3 is obtained. The silicon-based rubber masking pad 1 having the mold 4 as the inner cavity is obtained.

Since the masking pad 1 is rich in flexibility and elasticity due to the characteristics of silicone rubber, as shown in FIG. 5, a width that is a non-coated portion of the main portion 10 of the shell core 2 that requires a coating type. It can be easily fitted to the wood part.

As shown in FIG. 5, the main body portion 10 of the shell core 2 in which the masking pad 1 is fitted to the non-coated portion 3 is placed in the graphite coating agent 11 melted in the coating tank 9 as shown in FIG. After the coating is completed, the masking pad 1 is removed from the non-coated portion 3 after a drying step.

By the above-mentioned steps, it is possible to obtain a shell core in which a mold-coating agent is applied to the mold-coating portion excluding the non-coating portion 3 which is the baseboard portion projecting from the main portion 10 of the shell core 2.

[0023]

[Effect of the device]

 The present invention has the structure and operation described above, and when masking a non-coated portion when applying a mold coating agent to a casting shell core, a masking made of a silicone rubber liquid is used as a raw material. By adopting a pad, due to the heat resistance due to the characteristics of the silicone rubber, it is possible to adequately support the coating process with a mold agent under light heat after core molding, and it can be used repeatedly because it is elastic. In addition, a masking pad with good moldability that adheres to the core even with a complicated shape can be obtained, and it is flexible and easy to insert and remove without damaging the core, and it is an aqueous graphite coating agent. Since it has good peeling property and does not adhere to the masking pad, the masking pad can be used repeatedly, and the labor of the process of applying the mold release agent can be saved. Achieved is, also than Merumo provide an advantage that the securing of stable quality is achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a masking pad according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a non-coated portion which is a skirting board portion of a shell core.

FIG. 3 is a perspective view showing a prototype of a non-coated portion shown in FIG.

4 is a perspective view showing a molding means of the masking pad shown in FIG.

FIG. 5 is an explanatory longitudinal sectional view showing a means of fitting the masking pad shown in FIG. 1 in a shell core, immersing the shell core in the mold bath, and applying the graphite mold.

[Explanation of symbols]

 1 Masking pad 2 Shell core 3 Non-coated part 4 Female type

Claims (1)

[Scope of utility model registration request] 1. A female mold, such as a skirting board in a shell core made of shell sand for casting, which matches the shape of the non-coated portion of the coating agent is formed in the inner cavity and can be freely inserted into and removed from the non-coated portion. Masking pad made of silicone rubber.