JPH08281375A - Mold - Google Patents

Abstract

PURPOSE: To reduce a casting flash and to improve the durability and the formability of a flash removal press die and the quality of a cast product by arranging a sand leakage protecting space on the parting part of a mold jointing surface and arranging a projecting part for forming notches at the boundary part between a casting cavity and the sand leakage protecting space. CONSTITUTION: Since molten metal poured into the casting cavity 2 is flowed into the sand leakage preventing space 12, 13 from the projecting parts 14, 15, even if the sand leakage at the parting part is developed, the sand is flowed into the space 12, 13 and is not flowed into the casting cavity 7, and a sand in elusion defective product can drastically is reduced and the quality of the cast product can be improved. Then, the cast product is formed as the uniform flash on the whole periphery and also, the notches at the boundary with the product are formed at the upper and the lower parts. Therefore, the flash is easily removed by the flash removal press die. Further, since the flash is uniformly formed, the press die is easily manufactured and the excellent durability is obtd. and the service life can be extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold in which a plurality of upper and lower molds are molded by molding sand.

[0002]

2. Description of the Related Art As shown in FIG. 9, a general mold 31 is a molding sand 36 in which an upper mold 32 and a lower mold 33 are filled in molds 34 and 35 through a model (not shown). The parting portions 40 and 41 that are formed by, and that follow the die-matching surfaces 38 and 39 of the casting space 37 are provided with a draft angle of 3 degrees or less so that the die can be easily removed.

[0003]

By the way, in the above-mentioned prior art, the parting portions 40 and 41 are liable to lose their shape due to the spilling of the metal, and the casting product is formed by the sand that has collapsed due to the injection of the molten metal and has fallen into the pouring space 37. There is a problem that not only the sand debris is generated, but also non-uniform casting burrs are generated to shorten the life of the deburring press die, and the production of the press die is troublesome.

The present invention has been made in view of the above-mentioned actual situation, and an object thereof is to reduce casting burrs,
It is an object of the present invention to provide a mold capable of improving the durability and moldability of a deburring press mold and improving the quality of cast products.

[0005]

In order to achieve the above object, the present invention takes the following technical means. That is, the present invention is a mold in which a plurality of upper and lower molds are molded by casting sand, and a sand spill prevention space is provided in the parting portion of the mold matching surface, and a notch is formed at the boundary between the casting space and the sand spill prevention space. It is characterized by the provision of ridges.

Further, the present invention is a mold in which a plurality of upper and lower molds are molded by molding sand, and the draft of the peripheral wall of the pouring space following the parting portion of the mold matching surface has a slope close to the mold matching surface. It is characterized in that the angle is equal to or higher than 3 degrees and the draft of the portion following the angle is less than 3 degrees. The present invention is a mold in which a plurality of upper and lower molds are molded by molding sand, and a ridge is provided on one of the upper and lower molds of the parting portion of the mold matching surface.

Further, the present invention is a mold in which a plurality of upper and lower molds are molded by molding sand, and even when the peripheral wall of the casting space following the parting portion of the mold matching surface is arcuate in vertical section, It is characterized by a straight line extending from the parting portion to the required range.

[0008]

According to the present invention, the mold collapse due to sand spills at the parting portion of the mold is eliminated, and the casting burr is reduced, and
Cast burr becomes uniform. Therefore, spilled sand is prevented from entering the casting space, and the generation of sand scum in the cast product is greatly reduced, and the quality can be improved. Further, the durability of the deburring press die is improved, and the deburring press die can be easily manufactured.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the invention according to claim 1, in which a mold 1 is composed of an upper mold 2 and a lower mold 3 which are filled in a mold frame 4 and 5 through a model not shown in the drawing and are firmly fixed. Part 1 which is formed by the molding sand 6 and which continues to the mating surfaces 8 and 9 of the casting space 7.
The grooves 0 and 11 are provided with groove-shaped spill preventing spaces 12 and 13 over the entire circumference, and the notch forming ridges 1 face each other at the boundary between the casting space 7 and the sand spill preventing space.
4, 15 are provided all around.

The sand spill preventing spaces 12 and 13 preferably have a width W of about 2 mm and a depth D of about 1 mm. In FIG. 1, 16 is a hot water pool, 17 is a sprue, and 18 is a runway. When casting is performed using the mold 1 of the embodiment, the molten metal injected into the casting space 7 is
Since the water flows into the sand spill prevention spaces 12 and 13 from 4, 15 and 15
Flows into the casting space and sand does not fall into the casting space 7,
It is possible to significantly reduce defective products due to sand sand and improve the quality of cast products.

As shown in FIG. 3, the product 19 cast according to the above embodiment has a uniform casting burr 20 formed on the entire circumference thereof and notches 21 formed at the upper and lower sides of the boundary with the product 19. . Therefore, the casting burr 20 can be easily removed by a deburring press die (not shown). Moreover, since the casting burr 20 is uniform, it is easy to manufacture the press die, and the durability is increased and the life can be extended.

The notch forming ridge may be formed on only one side of the upper mold 2 or the lower mold 3. For example, FIG. 4 shows a main part of the above embodiment in which the notch forming ridges are formed on the upper mold 2. In this case, the formation of the notch-forming ridges on the lower mold 3 is omitted, so that the mold 1 is easily manufactured. As shown in FIG. 5, the product 19 thus manufactured has the notch 21 formed only on one side, which contributes to the improvement of the durability of the press die. The depth D of the sand spill space 12 is 3
It is desirable to set it to about mm.

FIG. 6 shows an essential part of an embodiment of the invention of claim 2 in which the basic structure of the mold 1 is the same as that shown in FIG. The shape of the peripheral wall of the subsequent casting space is different. That is, in this embodiment, the peripheral wall 2
2 and 23 are divided into two stages of peripheral walls 22A and 23A on the mold matching surfaces 8 and 9 and upper and lower peripheral walls 22B and 23B subsequent thereto, and the drafts θ1 and θ2 are respectively defined as drafts θ (3
The draft θ1 is 3 degrees or more and the draft θ2 is less than 3 degrees.

In the embodiment shown in FIG. 6, since the corners of the parting portions 10 and 11 of the mating surfaces 8 and 9 are well tightened when the molding sand is tamped, there is no mold collapse and no sand spillage occurs during casting. Hard to occur. Therefore, casting burrs can be significantly reduced, and sand debris can be eliminated. Further, since the die release resistance is small, the die release is easy. FIG. 7 shows the essential parts of an embodiment of the invention of claim 3, the basic structure of the mold 1 is the same as that shown in FIG. 1, but the mold matching surface of the upper mold 2 (or one side of the lower mold 3). 8 (or 9) parting part 1
0 and 11, low protrusions 24 are provided over the entire circumference, and when the upper and lower molds 2 and 3 are combined, the protrusions 24 bite into the parting portion 11 of the lower mold 3 to form a two-dot chain line 25 in FIG. The groove is formed as shown in FIG.

The width W of the ridge 24 is about 3 mm,
The height H is about 0.5 mm. However, it is desirable that the height H be set so as to have the optimum protrusion amount depending on the type and hardness of the foundry sand. According to the embodiment shown in FIG. 7, when the molten metal is poured into the casting space 7 of the mold 1, since the molten metal flows from the space 7 into the groove 25 of the parting portion 11, sand spillage occurs in the parting portion 11. However, the spilled sand flows into the groove 25. Therefore, sand burrs do not occur and casting burrs are reduced.

FIG. 8 shows an essential part of an embodiment of the invention of claim 4, in which the basic structure of the mold 1 is the same as that of FIG. 1, but the casting is continued to the parting parts 10 and 11 of the mating surfaces 8 and 9. Included space 7 peripheral wall 2
When the reference numerals 2 and 23 are arcuate strips R in the vertical cross section, the required ranges 22A and 23A from the parting portions 10 and 11 are linear. According to the embodiment shown in FIG. 8, the sand of the parting portions 10 and 11 is well tightened by tamping at the time of molding, there is no mold collapse, and the spilled sand does not fall into the casting space 7, and therefore the casting burr is not generated. As the number of sand casts decreases, sand fogging is significantly reduced, and the quality of castings can be improved.

The present invention is not limited to the above-mentioned embodiments, but can be applied to a mold produced by a floor-filling method or the like.

[0018]

As described above, the invention according to claim 1 is a mold in which a plurality of upper and lower molds are molded by molding sand, and a sand spill preventing space is provided in the parting portion of the mold matching surface, Since it is characterized by providing a notch-forming ridge at the boundary between the space and the sand spill prevention space, it is possible to prevent sand spillage into the casting space, so it is possible to eliminate sand dents in casting products, In addition to improving the quality, it is possible to extend the life of the casting deburring press die and reduce the cost by facilitating the production.

Further, the invention according to claim 2 is a mold in which a plurality of upper and lower molds are molded by molding sand, and the draft of the peripheral wall of the casting space following the parting portion of the mold matching surface is changed to the mold matching surface. It is characterized in that the portion close to is 3 degrees or more, and the draft of the portion that follows is less than 3 degrees, so that the mold can be easily removed and the mold does not lose its shape during molding. Is less likely to occur, sand scumming is reduced, and the quality of cast products can be improved.

The invention according to claim 3 is a mold in which a plurality of upper and lower molds are molded by molding sand, and a ridge is provided on one of the upper and lower mold halves of the mold matching surface. Since it is a feature, it is possible to reduce sand spillage into the casting space and prevent sand crushing, and to guide the collapsed sand to the groove formed in one of the parting sections to reduce casting burrs. You can

Furthermore, the invention according to claim 4 is a mold in which a plurality of upper and lower molds are molded by molding sand, and the peripheral wall of the casting space following the parting portion of the mold matching surface is arcuate in vertical cross section. Even if it is used, it is characterized by making a straight line from the parting part to the required range, so that it is possible to prevent mold collapse at the time of molding, reduce sand scuffing, casting burr, and molding work. Will be easier.

[Brief description of drawings]

FIG. 1 is a central longitudinal sectional view showing an embodiment of the invention described in claim 1.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a central vertical cross-sectional view of a cast product manufactured using the mold of the example.

FIG. 4 is an enlarged view of a main part of the mold of the embodiment, in which a notch-forming ridge is provided on one side.

FIG. 5 is a central longitudinal cross-sectional view of a casting product manufactured using the mold of the example in which a notch-forming ridge is provided on one side.

FIG. 6 is a central longitudinal sectional view showing a main part of an embodiment of the invention described in claim 2;

FIG. 7 is a central longitudinal sectional view showing a main part of an embodiment of the invention described in claim 3;

FIG. 8 is a central longitudinal sectional view showing a main part of an embodiment of the invention described in claim 4;

FIG. 9 is a central longitudinal sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold 2 Upper mold 3 Lower mold 6 Foundry sand 7 Casting space 8 Mold matching surface 9 Mold matching surface 10 Parting part 11 Parting part 12 Sand spill preventing space 13 Sand spill preventing space 14 Notch forming protrusion 15 Notch forming protrusion Article 22 peripheral wall 22A mold matching surface side peripheral wall 22B peripheral wall 23A mold matching surface side peripheral wall 23B peripheral wall 24 ridge 25 groove

Claims (4)

[Claims] 1. A mold in which a plurality of upper and lower molds are molded by molding sand, a sand spill preventing space is provided at a parting portion of a mold matching surface, and a notch forming protrusion is provided at a boundary portion between the casting space and the sand spill preventing space. A mold characterized by having a strip. 2. A mold in which a plurality of upper and lower molds are molded by molding sand, and a draft of a peripheral wall of a casting space following a parting portion of the mold matching surface is 3 degrees or more in a portion close to the mold matching surface, A mold characterized in that the draft of the portion following this is less than 3 degrees. 3. A mold in which a plurality of upper and lower molds are molded by molding sand, wherein a protrusion is provided on one of the upper mold and the lower mold of the parting surface of the mold matching surface. 4. A mold in which a plurality of upper and lower molds are molded by molding sand, and the peripheral wall of the casting space following the parting part of the mold matching surface is required from the parting part even when the longitudinal wall has an arc shape in a vertical cross section. A mold characterized by being linear over a range.