JPH0223258B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the manufacture of castings, and more particularly to molds for making hollow castings having vertical gap runners.

Molds are known that include a separable combination of at least two mold halves, a cavity forming a runner perpendicular to the separation plane, and a core mounted on a base. This type of mold is associated with casting techniques such as casting in cold hard molds and squeeze casting.

However, with this type of mold, the casting produced has a solid, flat, vertical interstitial runner which leads to the cast product itself. However, this means that the pre-cooling of the casting in the mold and the final cooling of the outside of the mold, in connection with the completion of the casting of said production and the subsequent crystallization of the hot metal, reduce the part of the casting that corresponds to the thin product. This results in deformation. This deformation is caused by the fact that the core is difficult to shrink, and during the final crystallization and cooling stage, the contraction of the hot metal in the gap runner is not hindered, and the compression or expansion coming from the gap runner causes the casting product. It arises because it extends to itself.

The object of the present invention is that the specific shape of the surface of the split mold within the split mold separation plane in the gap runner forming area is
The object of the present invention is to create a mold that allows the metal of the gap runner to contract independently of the cast product itself.

Said object is achieved in a mold mounted on a base having a core and a set of molds with cavities defining the runners of the casting in said mold separation planes, said mold A combination of at least one pair of split molds in the separation plane, one of the split molds having at least one protrusion, and the other split mold having a recess that is complementary to the protrusion. It has at least one.

The structure allows the metal of the interstitial runner to contract independently of the vessel wall of the cast product itself, without exerting any force on the vessel wall and causing subsequent deformation.

The split mold and core are provided with at least one convex portion on either one of the split mold and the core along the bottom contour of the surface forming the cast product itself, and the other side thereof is provided with at least one convex portion. It is appropriate to provide at least one concave portion that complements the convex portion.

This further indicates that the metal of the vessel wall of the cast product itself contracts along the bottom contour of the core, independently of the core, and independently of the sprues and runners connected to the vessel wall. enable.

In a preferred embodiment of the invention, each mold half and core of the mold assembly has cooperating protrusions and recesses along the bottom contour of the surface forming the cast product itself in the mold separation plane. This facilitates separation of the vessel wall of the cast product from the runner component when the metal of the cast product contracts.

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

The mold disclosed herein has a base 1 with a guideway 2, on which a pair of separable mold halves are disposed so as to be movable with respect to each other, a first
The assembled split mold shown in the figure includes two split molds 3 and 4 and a support member 5 of the base 1, and a fixed core 6 is mounted on the support member. However, the number of split molds and the number of sets may be increased to three (sets), four (sets), or more depending on the casting technology to be applied. This split mold is made of metal, ceramic,
It can be made of ceramic or core-lined porcelain alloy and foundry sand. When using the squeeze casting method, one of the mold halves may be provided with a shoulder 7 which can seal the longitudinal surfaces of the mould.

In the embodiment shown, each of the mold halves 3, 4 is connected to a drive cylinder 8, which has a housing held on the base 1.

One of said split molds, for example split mold 4, runs along the separation plane 9 in the cavity forming the vertical interstitial runner 10 and along the surface 11 forming the body of the casting 12 (FIG. 2) of the casting 13. It has at least one specially shaped protrusion 14 (FIG. 9) along the entire length of the contour, whereas the other split mold 3 has a space corresponding to the protrusion 14. and has a recess 15,
This recess 15 corresponds complementarily to the protrusion and is separated from the protrusion so as to form the main part of a vertical gap runner 16 .

The mold halves 3, 4 each have a protrusion 1 along the bottom contour of the surface 11 forming the cast product 12 itself.
7, on the other hand, a recess 1 complementary thereto
8 is provided on the circumference of the core 6. The convex portion 17
The relative arrangement of the recess 18 and the recess 1 in the split molds 3 and 4 is as follows.
8 and the recess 17 can be provided in the core 6, for example.

The protrusion 14 of one of the mold halves, for example the mold halves 4, is placed in a predetermined space (FIG. 10) along the length of the contour of the surface 11 forming the cast product 12 itself. The concave portions 15 may be arranged alternately with the concave portions, and for the other half of the split molds, the concave portions 15 complementary to the convex portions may be alternately arranged with the convex portions.If arranged in this way, each of the two split molds The recess 15 receives therein the opposing convex portion 14 of the other mold half, forming the main part of the vertical gap runner 16. One of the mold halves, for example the mold half 3, is connected to the separating surface 9.
In the outer direction of the surface 11 forming the cast product itself, as shown in FIGS. 6, 7 and 8, there are a convex portion 14 and a concave portion 15 connected thereto.
or, in some cases, may have a plurality of convex portions 14 and concave portions 15 alternately, and the other split mold 4 has complementary concave portions 15 and convex portions 14.

Similarly, one set of split molds 3 and 4 corresponds to the cast product 12.
Along the bottom contour of the surface 11 forming the body, it may have a protrusion 17 joining a recess 18 or a plurality of protrusions 17 alternating with recesses 18, said core 6 having an opposite complementary It has a target concave portion 18 and a convex portion 17.

The split molds 3 and 4 and the convex portions 14 and 17 of the core 6
The recesses 15 and 18 have a flat surface and a generally triangular cross section as shown in FIGS. 3 and 6, or a trapezoid as shown in FIGS. 4 and 7.
They can also have cylindrical surfaces as shown in FIGS. 5 and 8.

Before pouring hot water, the mold halves 3, 4 are separated. The core 6 is mounted on the support member 5 of the base 1. The drive cylinder 8 then operates to align the mold halves 3,4. A prescribed amount of hot water is poured into the space formed by the split molds 3, 4 and the core 6 in order to cast the cast product 13.

In the case of squeeze casting, the specified amount of hot water is injected into parts of the split molds 3 and 4 other than the abutting parts, and the gap between the split molds is sealed along the separation surface. The hot water is injected into the mold halves 3, 4 which are sealed by a shoulder 7 and aligned along the separation surface 9 using another casting technique.

The split molds 3, 4 have the split molds 3, 4 aligned with the specified amount of injected total amount of hot water when using the squeeze casting technique, and the molds 3, 4 when using other casting techniques. and hot water filling the internal space of the runner inlet system and left in alignment for crystallization of the hot water and precooling of the casting 13. At this stage, the cast product 12 and its side vertical gap runner system 16 are formed in the casting 13. The geometry of the runner 10 is defined by cooperating complementary protrusions 14 and recesses 15 of the mold halves 3, 4.
and the geometry of the cooperating complementary protrusions 17 of the mold halves 3, 4 and the recesses 18 of the core 6. This formed runner 16 is thus formed between the main part of the runner and the main part of the cast product 12 itself.
A tortuous connection is formed in the parting surface 9 of the split mold along the bottom contour of the mold.

During the pre-cooling stage within the mold, as well as during the final cooling stage of cooling the outside of the mold, the undulating shape of the area of the interstitial runner 16 halfway up to the main part of the cast product 12 itself is , which has a compensating effect to prevent the hot water from contracting freely in the runner and exerting direct forces on the thin main portion of the cast product 12 itself. This is because it is difficult for the hot water to shrink on the core 6.

The use of the mold having the structure disclosed herein has been discovered to increase the yield of high-quality castings and to improve their quality by casting the surfaces with high geometric precision. be. Defective products in which deformation of the vessel wall, cracks, or cracks occur in the casting due to nonuniform shrinkage of the hot water of the cast product 12 itself and nonuniformity of the runner system of the casting are removed on site.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a mold according to the present invention, FIG. 2 is a perspective view of a casting made with the mold shown in FIG. 1,
3, 4, and 5 are views showing various improved embodiments of the convex portion and its complementary concave portion in the separation plane of the group molds according to the present invention; FIG. 6, FIG. 7, and FIG. Fig. 8 is a view showing various improved embodiments of a plurality of convex portions and their complementary recesses in the separation plane of the split molds based on the present invention, and Fig. 9 is a view showing various improved embodiments of the plurality of convex portions and their complementary recesses in the separation plane of the split molds based on the present invention. FIG. 10 is a diagram showing an applied embodiment of the convex portions extending over the entire length of the split mold, and FIG. It is a figure which shows a recessed part. 1...Substrate, 3, 4...Separable split mold, 6...
... core, 9 ... mold separation surface, 10 ... cavity specifying the interstitial runner of the casting, 11 ... surface of the mold for forming the cast product, 12 ... the cast product itself,
13... Casting, 14... Convex portion within the cavity that specifies the gap runner within the split mold separation surface, 15... Concave portion within the cavity that specifies the gap runner within the split mold separation surface, 16...
Gap runner for casting, 17...Protrusion along the bottom contour of the surface of the split mold for forming the casting product itself, 1
8... Convex portion along the bottom contour of the surface of the split mold for forming the cast product itself.

Claims (1)

[Scope of Claims] 1. A mold having a set of split molds and a core each having a cavity and mounted on a base, wherein the cavity is a gap in the casting in the separation plane of the split molds. In the device for specifying paths and cores, at least one pair of split molds 3, 4 of the split molds is arranged such that one split mold is located within the area of the gap runner 16 within the separating surface 9 of the split molds. The mold has at least one convex part 14, the other split mold has at least one concave part 15 which is complementary to the convex part 14, and the convex part 14 and the concave part 15 are complementary to each other. The surface is
A mold for casting a hollow product, characterized in that the molds are separated by a distance that specifies the thickness of the gap runner 16 of the casting 13. 2. said separable mold and core 6 along the bottom contour of said surface forming the cast product 12 itself;
Claim 1, characterized in that there is at least one convex portion 17 on either the split mold or the core, and at least one concave portion 18 complementary to the convex portion 17 on the other side. A mold for casting hollow products according to item 1. 3. A patent characterized in that each pair of split molds 3 and 4 has a plurality of protrusions 14 on one split mold, and the same number of complementary recesses 15 as the protrusions 14 on the other split mold. A mold for casting hollow products according to claim 1. 4. The split mold and the core 6 have a plurality of convex portions 17 on one side and the same number of concave portions 18 for complementary coupling on the other side, as set forth in claim 2. Mold for casting hollow products.