JPH0313252A - Device for producing molding of core or casting or the like - Google Patents

Abstract

PURPOSE:To prevent the generation of the rapping crack of a bar-shaped projecting part by connecting a master mold and an inside mold in such a manner that the molds can be moved at a prescribed spacing and have repulsive force at all times. CONSTITUTION:The central, bar-shaped projecting part a3 is held at the front end by a rod 17 and is released from the inside mold 10b at the time of rapping. The circumferential projecting part a3 is released from the inside mold 10b while the half of the side wall surface thereof and the front end thereof are held by the master mold 10a; thereafter, the remaining circumferential part of the bar-shaped projecting part a3 is released from the master mold 10a. There is, therefore, no possibility that the rapping crack is generated in the bar-shaped projecting part a3 during rapping of the 2nd metallic mold 10.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention relates to an apparatus for manufacturing molded products such as core manufacturers and castings, and is particularly suitable for manufacturing molded products having a plurality of protrusions such as rod shapes. Between things.

(Prior Art) Conventionally, as shown in FIG. 4, a plurality of bar-shaped protrusions (hereinafter referred to as bar-shaped protrusions) a* are formed from one surface a2 of the base a1.
+ In order to manufacture the core a0 from which a3... protrudes by the cold box method or shell molding method, if the length of the rod-shaped convex portion a3 is relatively short, the base portion a1 is molded using a split mold. At the same time, the rod-shaped convex portion a3 is molded using a mold that can cut out the rod-shaped convex portion a3 in the longitudinal direction of the rod-shaped convex portion a3 and in the opposite direction to the base portion a1.

However, if the bar-shaped protrusion a3 is relatively long, so-called punching cracks will occur near the base of the bar-shaped protrusion a3 during die cutting, so that the base a! The base a1 and the bar-shaped protrusion a3 cannot be integrally molded, and therefore the base a1 and the bar-shaped protrusion a3 are separately molded and then glued together to obtain the core aO.

(Problem to be solved by the invention) However, in the above conventional molded product manufacturing apparatus,
In the case of cores with relatively long bar-shaped protrusions, the base and bar-shaped protrusions are molded separately and then glued together, which requires many manufacturing steps, resulting in high costs and the need for adhesion of the bar-shaped protrusions. There is a problem in that the accuracy of the core decreases if this is not done accurately.

The present invention has been made to solve the above problems, and its purpose is to provide a molded product manufacturing apparatus that can integrally mold even a relatively long bar-shaped convex part with a base part. On offer.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an apparatus for manufacturing a molded product such as a core or a casting, in which a protrusion such as a bar is protruded from the base. a first mold having a cavity for molding the mold, an outer mold and an inner mold, the mold having a cavity for molding the convex part therein, and a mold that is cut out in the longitudinal direction of the convex part; At the same time, a repulsive force is applied to a second mold joined to the first mold, the outer mold and the inner mold in the longitudinal direction, and both molds can be moved a predetermined distance in the longitudinal direction. a press connection means for connecting; and a pressure connection means for connecting the first mold and the second mold when joining the first mold and the second mold to form a cavity for molding the molded product.
The mold is joined against the repulsive force, and when the molded product is removed after molding, the outer mold and the inner mold are moved by the repulsive force, and then the first mold and the second mold are connected. It is characterized by comprising: a driving means for causing separation;

(Function) In the above configuration, when the first mold and the second mold are joined by the driving means against the repulsive force between the outer mold and the inner mold, and when the mold is cut by the driving means, the mold At the time of extraction, the outer mold and the inner mold move due to repulsive force, and the other mold acts to hold the convex part until one of the outer mold or the inner mold separates from the molded convex part. do.

(Example) Hereinafter, the present invention will be explained based on illustrated embodiments.

FIGS. 1(a) to (c) are cross-sectional views showing one embodiment of the apparatus of the present invention by process, and in which the core a shown in FIG.
. An example of manufacturing by the shell mold method is shown.

In the figure, 1 is a first mold 1 having a cavity b for molding the base a1 of the core a0, which is divided in the diameter direction of the base a1 as shown in FIG. 2.3. A pair of split molds 1a.

1b. On the underside of this first mold 1,
A guide tube 2 for guiding a second mold, which will be described later, is integrally provided concentrically with the base a1.

In the figure, 10 is a second mold having a cavity b2 for molding the rod-shaped protrusion ga3 of the core a0, and an outer mold 10a.
and an inner mold 10b. The outer periphery of the outer mold 10a is the same as the guide f! It has a size to be slidably inserted into the inner wall 2a of J2, and has a hole 11 that penetrates in the axial direction inside, and an inner mold 1ob that is slidably provided inside this hole 11. There is.

A recess formed by a part of the inner wall surface 11a of the hole 11 of the outer mold 10a and a corresponding part of the outer peripheral wall surface 10c of the inner mold 10b, and a recess formed at the center of the axis of the inner mold 1°b. 10
d, a cavity b for forming the rod-shaped convex portion a3
2 is formed.

At the lower end of the second mold 10, a seven flange 12 having a diameter equal to the diameter of the outer mold 10a is provided, and a plurality of through holes 13 are provided concentrically and equally spaced on the outer circumferential side thereof.
13... is being thrown.

A shaft portion 14 that is slightly longer than the thickness of the seven flange 12 and whose outer shape is smaller than that of the through hole 13 is inserted into the through hole 13, and one end of the shaft portion 14 is inserted into the outer mold 10a.
The other end is fixed to a disc 15 having a diameter slightly smaller than the outer diameter of the seven flange 12.

A through hole 16 is provided in the center of the inner mold 10a in the axial direction, and one end of this through hole 16 is a cavity b!
A rod 17 is slidably positioned on the inner wall surface of the disk and has its other end fixed to the disk 15.

In the figure, reference numeral 20 denotes a driving means for the second mold 10, which is composed of an air cylinder, and a head 22 having the same diameter as the disk 15 is provided at the tip of the piston rod 21.

This head 22 is fixed to the second mold 10 via a shaft portion 23. That is, a plurality of shaft parts 23, 23... are screwed concentrically and at equal intervals on the outer circumferential side of the head 22, and the shaft parts 23 are screwed into the through hole 18 provided in the disc 15. penetrates, and its tip is flange 1
It is screwed to 2.

A press connection means 30 is provided between the disc 15 and the head 22, and a force is applied between the two in the direction of separating them from each other.

That is, on the lower end surface of the disc 15 (the surface facing the head 22), guide bins 31, 31 and 31 are arranged concentrically and at equal intervals.
... is provided, and the tip of this guide pin is located approximately in the middle of the hole 25 which is recessed to approximately the middle of the thickness of the head 22, and the outer periphery of the guide pin 31 is provided with a spring. 32 is wound.

Therefore, due to the spring pressure of this spring 32, the
A repulsive force is acting between the disk 15 and the head 22. Therefore, there is a gap between the outer mold 10a fixed to the disc 15 via the shaft 14 and the inner mold 10b fixed via the head 22 and the shaft 23 in the axial direction (the rod-shaped protrusion a3). Forces that repel each other act in the longitudinal direction), and they are connected to be movable a predetermined distance in that direction.

In order to manufacture the core a0 with the apparatus of this embodiment having the above configuration, first, as shown in FIG. will be carried out.

That is, put the split molds 1a and lb together, and place the presser plate A on the upper end.
is set, and then the second mold 10 is inserted into the guide cylinder 2. Insertion of the second mold 10 is performed by raising the piston rod 21 of the drive means 20.

When the piston rod 21 rises, the head 22 provided at its tip and the second mold 10 fixed thereto via the shaft 23 rise, and the upper end of the outer mold 10a becomes the lower end of the first mold 1. join with. Even after this connection, the spring 32
When the piston rod 21 is raised against the
The lower end of a comes into contact with the upper surface of the flange 12, and the joining between the first mold l and the second mold is completed.

A cavity b! is formed in the first mold 1 and the second mold 10 by joining them together. A cavity b for molding the core a0 is formed by b2.

Cavity b is filled with molding sand coated with thermosetting resin from a supply port (not shown) provided in presser plate A. Note that the first mold 1 and the second mold 10 are heated to about 300° C. by a heating means (not shown).
(See Figure 1(a)).

After the casting sand has solidified, the piston rod 21 is lowered as shown in FIG. 1(b).

During this lowering, the outer mold 10
A and the rod 17 are not lowered and remain in the same position.

That is, the distance 1 until the disc 15 touches the flange 12
1td, while the inner mold 10b is separated from the bar-shaped convex part a by the press connection means 30, the outer mold 10a and the rod 17 remain in the same state, and a part of the side surface and the tip (not shown) of the bar-shaped convex part a3 are kept in the same position. (lowest end).

Then, the piston rod 21 further descends and the disc 15
comes into contact with the flange 12, the press connection means 30 is released, the outer mold 10a also descends together with the inner mold tab, and the rod-shaped part a
A second mold 10 is cut out from the mold 3 (see FIG. 1(c)).

In short, during this die cutting, the tip of the central bar-shaped protrusion a3 is held by the rod 17 and separated from the inner mold 10b, and the peripheral bar-shaped protrusion a3 has half of its side wall surface and its tip. It is held by the outer mold 10a and separated from the inner mold 10b, and then the remaining peripheral portion of the rod-shaped protrusion a3 is held by the outer mold 10a.
leaks from. Therefore, when the second mold 10 is punched out, there is no possibility that the bar-shaped convex portion a3 will be cracked.

After the rod-shaped convex portion a3 has been cut out of the mold as described above, the base portion a1 is removed from the mold as shown in FIG. 3<b>. That is, when the split mold 1b is released in the direction of the arrow, the knockout pin 3.3 is pressed by a spring (not shown) and smoothly released from the split mold 1b, and then the knockout pin 3.3 is used to remove the knockout pin 3.3 from the split mold 1a. is made female.

As described above, according to the present embodiment, the second mold 10 for molding the bar-shaped protrusion a3 of the core a is formed of an outer mold 10a and an inner mold 10b that move in the longitudinal direction of the bar-shaped protrusion a3. In addition, the outer mold 10a and the inner mold 10b are movable by a predetermined distance and are connected to each other so as to always have a repulsive force. Afterwards, the outer mold 10a is pulled out. For this reason, the inner mold 10
Since the bar-shaped protrusion a3 is held by the outer mold 10a until the bar-shaped protrusion a3 is separated from the bar-shaped protrusion a3, occurrence of punching cracks in the bar-shaped protrusion a3 is effectively prevented.

Therefore, even a core a) having a relatively long bar-shaped convex portion a3 can be manufactured by integral molding.

In addition, in the above-mentioned embodiment, an example was shown in which the core a is manufactured by a shell molding method, but it may be manufactured by a cold box method.

Further, although the inner mold 10b is pulled out first and then the outer mold 10a is pulled out, this may be done in the reverse order.
In this case, the structure is such that the inner mold 10b is pressed by the pressing connection means 30.

Furthermore, an example is shown in which the rod-shaped protrusion a is also provided at the center of the base a1, and a cavity for this purpose is provided inside the inner mold 10b, but in the case where such a central rod-shaped protrusion a3 is not provided. Naturally, the rod 17 is omitted.

In the above-mentioned example, a core was shown as an example of a molded product, but
The molded product may be a casting made of an aluminum alloy or the like. In this case, molten metal is cast into the cavity instead of S-molding sand. Then, during die cutting, there is no risk of cracking at the root of the rod-shaped convex part, as in the above embodiment.
High quality castings can be obtained.

(Effects of the Invention) The apparatus of the present invention includes a second mold having a cavity for molding a rod-shaped projection of a molded product, and an outer mold and an inner mold for cutting out the rod-shaped projection in the longitudinal direction. Since the outer mold and the inner mold are movable by a predetermined distance and are connected so as to have a constant repulsive force, the outer mold and the inner mold are pulled out with a time difference when the second mold is removed. .

Therefore, until one of the outer mold and the inner mold is separated from the bar-shaped protrusion, the other mold holds the bar-shaped protrusion, thereby effectively preventing the occurrence of punch-out cracks in the bar-shaped protrusion. Therefore, even a core having a relatively long bar-shaped convex portion can be manufactured by integral molding using a mold.

[Brief explanation of drawings]

Figures 1(a) to (C) are cross-sectional views of each manufacturing process of the device of the present invention, Figures 2.3 are cross-sectional views taken along lines ll-l1l and G of Figure 1(a), and Figure 4 is FIG. 3 is a perspective view of a core having a bar-shaped protrusion. 1...1st mold, la, lb...split mold, 2...
Guide tube, 10... second mold, 10a... outer mold,
10b...inner mold, 12...flange, 15...
Disc, 20... Drive means, 21... Piston rod, 22... Head, 30... Press connection means, 32
···spring. ao... core (molded product), a3... bar-shaped convex part, m2 figure Fig. 3

Claims (1)

[Scope of Claims] An apparatus for manufacturing a molded product such as a core or a casting having a protruding portion such as a rod-shaped portion protruding from a base, comprising: a first mold having a cavity for molding the base; A second mold is composed of a mold and an inner mold, has a cavity therein for molding the convex part, and is die-cut in the longitudinal direction of the convex part, and is joined to the first mold. a mold; a pressing connection means that applies a repulsive force to the outer mold and the inner mold in the longitudinal direction and connects the two molds so as to be movable a predetermined distance in the longitudinal direction; and the first mold and the second mold. When joining molds to form a cavity for molding the molded product, the first mold and the second mold
The mold is joined against the repulsive force, and when the molded product is removed after molding, the outer mold and the inner mold are moved by the repulsive force, and then the first mold and the second mold are connected. 1. A device for producing molded products such as cores or castings, characterized by comprising: a driving means for separating;