JPS6232675Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a molding device for a shell mold having a main part that is thin and a part that has thick protrusions.

(Prior Art) It is well known that a core shell mold for casting an engine cylinder is manufactured as a shell mold using a molding apparatus, for example, as shown in Japanese Patent Publication No. 56-42744. The main part is a thin wall that forms a cooling water passage on the outer circumference of the cylinder,
If this part has a thick protrusion that forms a cooling water inlet or a sand removal hole, the firing time for the shell sand will take longer for the thicker part, so even if the thin part is completely hardened, the shell sand will still be thick. The meat projections are in an unhardened state, and if the shell mold is released from the mold in this state, there is a risk that the insufficiently hardened projections will be damaged. In particular, in order to form the thick protrusion,
If a part of the mold has an auxiliary mold that can freely move in and out of the molding space, if the auxiliary mold is removed with the protrusion unhardened, the protrusion will be inserted into the recess of the auxiliary mold. The shell sand used for forming the mold moves while remaining attached to it, making it impossible to form the protrusion, and it also takes a long time to remove the shell sand from the recesses of the auxiliary mold, causing the thick protrusion to harden. It was necessary to enable good release from the auxiliary mold.

For this reason, conventionally, the shell mold is removed from the mold after waiting until the thick protrusion has completely hardened. Therefore, the time for firing the shell, that is, the time for setting the shell mold in the mold, becomes longer, which is an obstacle to improving the operating rate of the molding apparatus.

(Purpose of the invention) In view of the above-mentioned circumstances, the present invention improves the operation rate by making it possible to remove the shell mold from the mold even when the protrusion is not sufficiently hardened. The object of the present invention is to provide a shell mold making device having the following features.

(Structure of the invention) The shell mold molding device of the present invention includes an auxiliary mold that is provided in a part of the molding die so as to be able to move in and out of the molding space in order to form a thick protrusion. The main part of the auxiliary mold molds the outer periphery of the thick protrusion, and the end face molding part molds the tip end face or part of the thick protrusion. So that it can be pulled out from the protrusion and operated.
The main body of the auxiliary mold and the operating cylinder are connected,
The present invention is characterized in that the main body of the auxiliary mold is pulled out and the shell mold is taken out immediately after the thin-walled portion is completely cured.

(Effect of the invention) When removing the main body of the auxiliary mold, by fixing the end face or a part of the thick protrusion with the end face molding part, even if the thick protrusion is not sufficiently hardened, the thickness can be reduced. The shell mold can be removed from the mold without damaging the thick protrusions, and therefore the molding work can be carried out without the thick protrusions completing curing, which shortens the molding takt time and increases operation time. It is possible to improve the ratio.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.
The drawing shows the main parts of the molding device 1, and the shape of the molding space C of the molding die 2, that is, the shape of the shell mold 3 molded by the molding die 2, is such that the main part has a thin wall 3a.
However, a portion of the roller has a thick protrusion 3b.

The above molding die 2 is a thick protrusion 3 of a shell mold 3.
In order to form the molding space C, an auxiliary mold 4 is provided in a part of the molding space C so as to be freely retractable. The auxiliary mold 4 is divided into an auxiliary mold main body 4a that forms the outer periphery of the thick protrusion 3b, and an end face molding part 4b that molds a part of the tip surface of the thick protrusion 3b.

The end face molded part 4b is formed into a rod shape, and its base end passes through the front plate 6a and piston 6c of the working cylinder 6 fixed to the molding die 2 via the bracket 5, and is fixed to the rear plate 6b. A hollow rod 6d fixed to the piston 6c of the actuating cylinder 6 is provided to slide along the outer periphery of the end face molded portion 4b.

On the other hand, the auxiliary mold main body 4a has an end face molding portion 4
The rod 6 of the operating cylinder 6 attached to the outer periphery of b
d, and by supplying working pressure to the front chamber 6e or rear chamber 6f of the operating cylinder 6, the rod 6d is moved forward and backward, and the auxiliary mold hand body 4a moves in and out along the end face molding part 4b. It is set up like this.

The auxiliary mold 4 has a rear chamber 6f of the operating cylinder 6.
The auxiliary mold main body 4a is advanced by supplying working pressure to and stopped at a predetermined position in the molding mold 2 to form a molding space C that matches the shape of the thick protrusion 3b of the shell mold 3. Shell sand is blown into this molding space C to fill it. The molding die 2 is heated in advance, and the shell sand in the molding space C is hardened by this heat. 3b is in an insufficiently hardened state, but at this time, operating pressure is supplied to the front chamber 6e of the operating cylinder 6, and the auxiliary mold main body 4a is pulled out in the backward direction. At this time, since the tip of the thick protrusion 3b is fixedly held by the tip surface of the end face molding part 4b, the thick protrusion 3b is insufficiently hardened by the extraction operation of the auxiliary mold main body 4a. However, no damage was caused, and the shell mold 3 was then taken out from the molding die 2. Note that the thick protrusion 3b is completely hardened with residual heat and the passage of time.

By repeating the above operation, the molding device 1 can mold the thick protrusion 3 of the shell mold 3 in a short tact.
This can be done without the loss of b. Also,
The end face molding portion 4b also serves as a guide for the auxiliary mold main body 4a, thereby making the device more compact.

[Brief explanation of drawings]

The drawing is a cross-sectional view showing the main parts of a molding device according to an embodiment of the present invention. 1... Molding device, 2... Molding die, 3... Shell mold, 3a... Thin wall, 3b... Thick wall protrusion, 4
...Subsidy mold type, 4a...Subsidy mold main body, 4b...
End face forming section, 6...operating cylinder, C...molding space.

Claims (1)

[Scope of utility model registration request] A shell mold making device having a main part with a thin wall and a part with a thick wall protrusion, wherein the shell mold is provided in a part of the molding die so as to be freely protrusive and retractable in a molding space in order to form the thick wall protrusion. The auxiliary mold to be used is divided into a main part of the auxiliary mold that molds the outer periphery of the thick protrusion, and an end face molding part that molds the tip end face or a part of the thick protrusion, and the end face molding part is immovable. In this state, only the main body of the auxiliary mold can be pulled out from the thick protrusion.
A shell having a thick-walled protrusion in a part, which is formed by connecting the auxiliary mold main body and an operating cylinder, and operates to pull out the auxiliary mold main body to take out the shell mold as soon as the thin-walled part is cured. Mold making equipment.