JP3183709B2 - Casting soundness evaluation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for evaluating the soundness of a cast product, for example, the airtightness of the cast product.

[0002]

2. Description of the Related Art A conventional method for evaluating the soundness of a cast product (1) is as follows.
As shown in FIG. 4, the test solution (10) is applied to the test surface to penetrate the defective portion (4), and then the excess solution on the test surface is wiped off, and then the developer (11) is applied to the test surface. , Defective part (4)
The flaw detection liquid (10) that has permeated into the developing solution (10) oozes out and reacts with the developing liquid (11) to detect the defective portion (4). This method is one application of the nondestructive inspection method.
The defect that the flaw detection liquid (10) oozing from the defect part (4) blurs in the development reaction part, and the type and size of the defect part (4) such as size and depth cannot be clearly detected,
In this method, the test solution (10) soaked into the wound is converted into the developer (11).
Since only the phenomenon of bleeding and reacting is used, it is possible to know the presence or absence of a defect (4) opening on the test surface, but it is not clear at all how the defective portion (4) is connected. In the case of an important application, there is a problem that this inspection method is completely useless. In FIG. 4, the wound portion is indicated by a broken line, and the reaction portion of the test solution (10) that has oozed and reacted is indicated by a blur.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the prior art, and the position and size of a defect can be clarified by directly injecting a coloring agent into a defective portion and directly dyeing the same. It is an object of the present invention to provide a method for evaluating the soundness of a cast product, which can be determined and at the same time, the degree of connection of a defective portion can be visually observed at a glance and the airtightness can be evaluated at the same time.

[0004]

According to a first aspect of the present invention, there is provided a cast product comprising:
After applying the colorant (2) to the test surface of (1), cover the applied surface with a sheet (3) to keep the covered part airtight, and then
Defective part of cast product (1) by applying pressure on coated surface from sheet (3)
(4) impregnating the coloring agent (2) with the coloring agent (2) to dye the defective portion (4) of the casting (1). "

As a result, a defective portion communicating with the test surface
The coloring agent (2) is forcibly pressed into (4), and the defective portion (4) is dyed, so that the size and shape of the defective portion (4) clearly emerges as they are. And the defect (4)
If the color reaches the back, the colorant
(2) overflows from the back surface, and it can be visually observed that the test surface and the defect (4) are completely communicated with each other and the airtightness is impaired.

The second aspect of the present invention relates to a case where a pressure reducing means is further added. "After applying the colorant (2) to the test surface of the casting (1), the coated surface is covered with the sheet (3) to cover the coated portion. Maintain the airtight condition, and then apply pressure from the sheet (3) to the surface of the casting (1).
(4) by impregnating the coloring agent (2) with the coloring agent (2) and dyeing the defective portion (4) of the casting (1) with the coloring agent (2) to visualize the defective portion (4) ”.

By adding a decompression means, it becomes possible to detect a finer defect (4).

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Figure 1 shows a block-shaped casting for soundness evaluation (1)
There is a cone-shaped shrinkage nest (5) in the center. Many defects (4) such as pinholes are scattered around the shrinkage nest (5),
Part of it communicates with the shrink nest (5). In the first embodiment,
FIG. 2 shows the procedure for evaluating the soundness of the shrinkage cavity (5) and the defect (4) communicating therewith.

First, a shrinkage cavity which is a test surface of the cast product (1)
Apply the colorant (2) to (5). The amount of the coloring agent (2) needs to be a certain amount because it is necessary to measure the penetration of the coloring agent (2) into the defective portion (4). In this embodiment, the shrinkage cavity (5) is filled with the coloring agent (2). After the filling of the colorant (2) is completed, the shrinkage cavities (5) are covered with a sheet (3) to keep the covered portion airtight. (6) is a binding band for fixing the sheet (3). The sheet (3) may be fixed by any method as long as the airtightness of the test surface is maintained.

After that, the coloring agent (2) is pressed into and penetrated into the defective part (4) of the casting (1) which can communicate with the shrinkage cavity (5) by pressing the application surface from above the sheet (3). The defective part (4) of the casting (1) is dyed up with the coloring agent (2). Of course, there is no penetration of the colorant (2) into the stand-alone defect (4) not communicating with the shrinkage cavity (5). Casting
If defects (4) reach the surface of (1), shrinkage cavities (5)
The colorant (2) press-fitted from above is extruded from the surface of the casting (1), and it can be seen at a glance that the casting (1) has no airtightness.

Further, in order to examine the internal condition of the cast product (1) in more detail, it is preferable that after the colorant (2) is dried, it is cut from the center and the penetration condition of the colorant (2) is examined. Even if the colorant (2) is not extruded on the surface of the casting (1), the colorant will reach the surface
In some cases, (2) has penetrated, and in such a case, it is determined that the casting state is poor in the evaluation of the airtightness.

As the colorant (2) to be used, any one may be used as long as it has low viscosity. In this embodiment, a colored lacquer is used. The pressing means may be any means that can press the coated surface from above the sheet (3),
In this embodiment, a pressure vessel is used to pressurize the entire casting (1). Of course, partial pressurization may be used. The sheet (3) is preferably one that has extensibility and airtightness, such as a rubber sheet (3).

FIG. 2 shows a second embodiment of the present invention.
This is the case where the test surface of (1) is flat. In this case, since the amount of the colorant (2) applied is limited, it is preferable to increase the amount of application using the jig (7). The jig (7) has a ring shape surrounding the test surface, and is fixed to the test surface by some fixing means. In this embodiment, bolt fixing is performed. A sealing material (8) is interposed on the contact surface between the casting (1) and the jig (7) if necessary to maintain airtightness. After doing this, as described above, the concave portion formed by the jig (7) is filled with a sufficient amount of the coloring agent (2), and airtightly covered with the sheet (3). Pressurize and colorant (2)
Infiltrate the defective portion (4).

As a third embodiment of the present invention, it is conceivable to add a decompression means. That is, pressure is applied to the colorant (2) application surface via the sheet (3), and a portion other than the test surface is suctioned under reduced pressure, thereby more effectively penetrating the colorant (2) into the communication defect (4). It is done. As a result, a stricter airtightness test can be performed.

[0015]

According to the method for evaluating the soundness of a casting according to the present invention,
After applying the colorant to the test surface of the casting, cover the application surface with a sheet to keep the coating airtight, and then press the application surface from above the sheet to apply the colorant to the defective part of the casting. Since the defective portion of the casting is dyed with the coloring agent by infiltration, the defective portion is displayed as it is, and its size and shape can be visually observed in a very clear shape. Moreover,
Since the colorant penetrates from the test surface, defects communicating with the test surface can be clearly distinguished from defects that are not, which is advantageous particularly in airtightness tests.

Further, in the case of the second aspect, the case where the decompression means is added, whereby the penetration of the coloring agent into finer defects is promoted, and more precise evaluation becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a first embodiment of the present invention.

FIG. 2 is a drawing of a working procedure of the present invention.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of a test result obtained by a conventional method.

[Explanation of symbols]

 (1) Casting (2) Colorant (3) Sheet (4) Defective part (5) Shrinkage cavity (6) Binding band (7) Jig (8) Sealant (10) … Test solution (11)… developer

Continuation of the front page (56) References JP-A-49-27469 (JP, A) JP-A-2-167453 (JP, A) JP-A-1-173855 (JP, A) JP-A-56-10253 (JP) , A) Actual opening 50-79485 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/91

Claims (2)

(57) [Claims] After applying a colorant to a test surface of a cast product, the coated surface is covered with a sheet to keep the coated portion airtight, and thereafter, the coated surface is pressed from above the sheet to cause a defect in the cast product. A method for evaluating the soundness of a cast product, characterized in that a defective portion is visualized by dyeing a defective portion of the cast product with a colorant by penetrating a colorant into the portion. 2. After applying a colorant to the test surface of the casting, the coated surface is covered with a sheet to keep the coated portion airtight, and then the coated surface is pressed from above the sheet except the test surface. A method for evaluating the soundness of a casting, characterized in that the defect is visualized by sucking from the surface of the above and infiltrating a coloring agent into the defective portion of the casting and coloring the defective portion of the casting with the coloring agent.