JPS60247456A - Dividing method of casting mold - Google Patents

Abstract

PURPOSE:To extend the service life of reconditioned molding sand in the stage of casting a casting with a casting mold divided to upper and lower parts by removing the molten metal in the sprue provided to a cope to eliminate the molding sand to be stuck to the sprue in the stage of dividing the casting mold and taking out the casting. CONSTITUTION:Two casting spaces 14 are formed in the divided casting mold 1 consisting of the cope 2 and drag 3 and are connected by a horizontal runner 11. The funnel-shaped sprue 13 provided to the cope 2 and the vertical runner 12 continuous therewith are connected to the runner 11. The molten metal is poured through the spure 13 and is cast into the spaces 14 through the runner 12 and the runner 11. The molten metal accumulated in the sprue 13 is dipped by rotating a molten metal ladling member 28 provided to a molten metal ladling device 20 around a turning shaft 27 before the molten metal in the sprue 13 solidifies. There is no solidified metal in the sprue 13 in the case of detaching the cope 2 from the drag 2 after solidification and therefore there is no molding sand sticking thereto. The mixing of the molding sand and core sand is thus obviated, by which the number of reusing the molding sand and core sand is increased.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides a method for dividing a mold into an upper mold and a lower mold and removing the cast body formed inside the mold while leaving it on the lower mold side. This relates to a method of dividing a mold made into a mold.

(Prior Art) Conventionally, as a method for removing a cast body formed inside a sand mold from the mold, the mold and the cast body are integrally removed from the flask while the cast body is contained inside the mold. One method is to place this on a vibration device to collapse the mold and take out the cast body inside, and the other is to divide the mold into an upper mold and a lower mold without collapsing the mold and remove only the cast body inside the mold. There is a way to take it out.

In the former method, when the mold is collapsed using a vibration device,
If a core is provided inside the cast body, this core is also destroyed at the same time, so the foundry sand that forms the mold and the core sand, which is different from the foundry sand, are mixed, and the foundry sand is mixed. There is a problem in that the service life of the foundry sand is shortened due to changes in quality.

On the other hand, in the case of the latter method, there is no risk of the core collapsing and the core sand getting mixed into the foundry sand, so the quality of the foundry sand and core sand is maintained at a good level over a long period of time. There are advantages.

By the way, in the sand mold, as shown in FIG. 4(A), there is a pouring chamber 59? The upper surface 52 of the upper mold 52 is located at the upper end of the vertical runner 57 rising vertically from the horizontal a-way 5S communicating with this.
A funnel-shaped sprue 54 that expands toward a is formed, and the molten metal is poured into the pouring chamber 59 from the sprue 54 so that the surface of the molten metal flows into the sprue 54.
In this way, the funnel-shaped sprue 54 is provided at the upper end of the vertical runner 57 and the pouring is performed from the sprue 54. When the molten metal is filled up to the inside of the sprue 54, (1) the dynamic pressure of the molten metal during pouring is suppressed to prevent the wall surface of the vertical runner 57 from collapsing (roughing), and (2) the receiving area for the molten metal is secured. (3) Ensure the required m1Jt by compensating for variations in the pouring amount when pouring using a pouring machine, (4) Pouring speed and pouring Effects such as realizing continuous pouring by absorbing the difference in speed can be obtained. Therefore, in order to obtain a high quality cast product using a sand mold, the sprue 54 having the above structure is indispensable.

However, when the molten metal filled in the sprue 54 solidifies inside the sprue 54 and becomes the sprue bulge 55 having a larger diameter than the vertical runner body 60 formed in the vertical runner 57, As shown in B), the mold 5I is divided into an upper mold 52 and a lower mold 53.
When taking out the cast body 56 formed inside the mold 51 by dividing it into two parts, the sprue bulge 55 not only gets caught in the surrounding molding sand, but also prevents the mold 51 from being divided. When the mold 51 is forcibly divided, a large amount of molding sand from the upper mold 52 adheres to the lower part of the sprue bulge 55, resulting in a residual hole, which is formed during the conveyance of the cast body 56 to the sand removal process. There is a risk that the sand will collapse and fall, causing a deterioration of the working environment, or that it will get mixed into the core sand during sand removal, leading to a deterioration in the quality of the core sand.

(Objective of the Invention) The present invention was made in an attempt to solve or improve the problems in the method of dividing a mold and taking out the cast body inside the mold, as pointed out in the section of the prior art. The purpose of this is to simplify the work of dividing the mold by making it easier to divide the mold, and (2) to reduce as much as possible the amount of foundry sand that remains on the side of the cast body when the cast body is taken out.

(Means for achieving the object) The present invention is a means for achieving the above object.
After the molten metal is poured into the mold, the molten metal in the sprue is taken out from the sprue to the outside by means of pumping the molten metal out of the sprue before the molten metal solidifies. It is.

(Function) In the present invention, by the above-mentioned means, (1) the mold is easily divided because the cast body taken out from the mold is not formed with a sprue bulge that inhibits the dividing action of the mold; (2) The effect is that the amount of molding sand that adheres to the cast body and is taken out is reduced as much as possible.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 1 to 3.

FIGS. 1 and 2 show a mold l used for carrying out the present invention.
and a molten metal extraction device 20 are shown.

The mold 1 is composed of an upper mold 2 molded and held by an upper mold 4 and a lower mold 3 molded and held by a lower mold 5, which are brought together in the vertical direction. A pouring chamber IO for forming a casting is formed at the abutting portion of the mold 3. The pouring chamber IO communicates with a funnel-shaped sprue 13 formed to open on the upper surface 2a of the upper mold 2 via a horizontal runner 11 and a vertical runner 12 rising upward from the horizontal runner 11. (This pouring chamber lO, horizontal runner 11 and vertical runner 12
and sprue 13 constitute a series of pouring spaces]4). The sprue 13 has an arcuate cross section that bulges downward along the rotation locus of a sprue 28a of a pumping member 28 of a molten metal extraction device 20, which will be described later. It is set so that it gradually decreases from the upper surface 2a of 2 toward the vertical runner 12 side. This mold 1 is sequentially transported by a transport line (not shown) from a pouring process to a molten metal removal process equipped with a molten metal removal device 20 (described later), and further to a demolding process.

The molten metal extraction device 20 is slidably inserted into a fixing rod 21 extending from the side of the conveyance line toward the conveyance line, and is inserted into the fixing rod 21 by expanding and contracting the telescoping cylinder 24. A pumping member 28 having an arc-shaped rake face 38 centered on the rotation shaft 27 is attached to the tip 22a of the telescopic rod 22, which can be moved vertically and rotated in an arc. That is, the pumping part'r! 28 has its rotation shaft 27 rotatably supported via a bracket 26 on a lift cylinder 25 attached vertically to the tip 22a of the telescoping rod 22. It is moved up and down as the lift cylinder 25 expands and contracts. Further, a rotating cylinder 3I is connected to this rotating shaft 27 via a rotating lever 29 fixed to the rotating shaft 27, and the pumping member 28 is connected to this rotating cylinder 31.
It is designed so that it can be rotated in an arc as appropriate as it expands and contracts.

The horizontal position, vertical position, and rotating position of this pumping member 28 are set as follows with respect to the mold 1.

That is, in the horizontal direction, the pumping member 28 is located at an advanced position (as shown by the solid line in FIG. position or the position shown in Figure 2), and a retracted position located horizontally outward from the mold l (Figure 1,
It is selectively positioned at two positions indicated by chain lines and reference numeral 28). In addition, in the direction of rotation, this pumping member 28 is in a first rotation position with its scoop face 38 facing downward as shown by the solid line in FIG. (in other words, the suction port 28a is directed downward) and the first rotation position as the lift cylinder 25 is reduced, as shown by chain lines (28', 28) in FIG. It is selectively positioned at one of three rotational positions including a third rotational position rotated slightly forward of the rotational position (towards the counter-rotation cylinder 31 side). Furthermore, this pumping member 2
8 is -1- In the downward direction, the pumping member 2 is positioned at the first rotational position as shown by the solid line in FIG.
The lower movement position where the rake face 38 of No. 8 substantially contacts the sprue I3 of the mold 1, and the lower position where the rake face 38 of No.
As shown in FIG. 28''), its parts 38 are selectively positioned at two two-movement positions, which are located above the upper surface 2a of the upper die 2.

Next, the mold 1 and the molten metal extraction device 20 shown in FIG.
To briefly explain the method of producing a cast product using a mold, first, in the pouring process, the pouring space 14 including the pouring chamber 10 of the mold L is filled with molten metal using a pouring machine or pouring machine. (See Figure 2).

When the pouring operation is completed, the mold 1 is transported by a transport line to a molten metal removal step, and during this transport time, the molten metal in the mold 1 is gradually cooled to such an extent that the molten metal in the sprue I3 does not solidify.

On the other hand, in the molten metal removal process, as shown in FIG. 2, the molten metal removal device 20 is on standby with its pumping member 28 in the forward position, the lower movement position, and the second rotation position. When the mold 1 sequentially transported by the transport line stops at a predetermined position directly below the pumping member 28 in this standby position, the pumping member 28 starts to take out the molten metal from the sprue I3 of the mold I. That is,
First, as shown in FIG. 2, the pumping member 28 is in the second rotation position.
rotates from the second rotation position to the first rotation position as the rotation cylinder 31 contracts, and during the rotation, the molten metal in the sprue I3 is pumped into the pumping member 28 with its suction port 28a. (FIG. 1, solid line diagram). Therefore, only the molten metal filled in the pouring space 14 on the side closer to the vertical runner 12 remains on the mold 1 side. When the pumping of the molten metal is completed, the lift cylinder 25 is then contracted and the pumping member 28 is raised from the F position to the "second position" as shown by the chain line (reference numeral 28') in FIG. The contact state between the pumping member 28 and the mold l is released. (At this time, the pumping member 28 is rotated from the first rotation position to the third rotation position). When the pumping member 28 is positioned at the upward movement position, the mold 1 is conveyed to the next step, a demolding process, by a conveyance line, and is demolded as described below.

On the other hand, the pumping member 28 pumping the molten metal into the third
The fixing rod 21 is retracted from the forward position to the retracted position while remaining in the rotation position. (
FIG. 1, chain line illustration, reference numeral 28#).

When the pumping member 28 is positioned at the retracted position, the pumping member 28 is rotated from the first and third rotational positions to the second rotational position in accordance with the extension of the rotational cylinder 3I, and pumps out the molten metal therein to a predetermined position. Discharge into container.

When the discharge of the molten metal is completed, the pumping member 28 is again moved to the forward position and held in the standby position as shown in FIG.

On the other hand, inside the mold 1 sent to the demolding process, there is a third
As shown in Figure (A), a product body 7 made of molten metal filled in the pouring chamber IO, a horizontal runner body 87 made of molten metal filled in the horizontal runner 11, and a product body 7 made of molten metal filled in the vertical runner 12. A cast body 6 is formed by integrally joining a straight bar-shaped vertical runner body 9 made of the molten metal. That is, this cast body 6 has a sprue that is formed by solidifying the molten metal filled in the sprue I3 that opens on the upper surface 2a of the upper mold 2, and that acts to prevent the upper mold from separating from the lower mold 3. Bulging part (Fig. 4 (B)
There is no part corresponding to the part indicated by reference numeral 55),
On the upper surface 2a side of the upper mold 2, the upper end surface of a straight bar-shaped vertical runner body 9 is exposed. Therefore, when the mold 1 is divided into the upper mold 2 and the lower mold 3, the upper mold 2 is divided into the third mold 2 and the lower mold 3. As shown in Figure (B), the cast body 6 is left on the lower mold 3 side with almost no deformation (in other words, almost no molding sand from the upper mold 2 remains on the cast body 6 side). It can be easily separated from 3.

After separating the upper mold 2 and the lower mold 3, the cast body 6 remaining on the lower mold 3 side is taken out from the lower mold 3 and sand is removed.

In this case, since there is almost no foundry sand attached to the cast body 6, it is very easy to remove the sand, and even if a core is present, the amount of foundry sand that gets mixed into the core sand is small. , the quality of the core sand can be maintained well over a long period of time.

In the above embodiment, the molten metal filled in the cap 3 of the mold 1 is removed by the pumping member 28, but the molten metal in the sprue I3 is removed. In this case, other means such as sucking out the molten metal in the sprue I3 with a pump may also be adopted.

(Effects of the Invention) As is clear from the above explanation, the mold dividing method of the present invention is as follows: (1) The mold is formed in the mold by removing the molten metal filled in the sprue before the molten metal solidifies. Since the mold is prevented from forming a sprue bulge that would inhibit the mold from being divided, the mold can be easily divided and the dividing work can be simplified. 2) Since the cast body does not have a sprue bulge that inhibits mold splitting, the amount of molding sand that adheres to the cast body and is taken out when the mold is split is reduced as much as possible. In a mold equipped with a mold, mixing of the core sand and foundry sand can be prevented as much as possible, and the quality of both foundry sand and core sand can be maintained at good quality over a long period of time. .

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of the main parts of a casting apparatus used for carrying out the present invention, Fig. 2 is a state change diagram of the main parts of the casting apparatus shown in Fig. 1, and Figs. 3 (A) and (B). 4(A) is a vertical cross-sectional view of a conventional mold, and FIG. 4(B) is a diagram of the mold divided according to the conventional method. 1 ... Mold 2 ... Upper mold 3 ... Lower mold 4.5 ... Casting flask 6 ... Casting body 10 ... Pa/pouring chamber 11...Horizontal runner 12...Vertical runner 13...Tall runner 20...Molten metal removal device 21...Fixing rod 22...Expansion and contraction Rod 24... Telescopic cylinder 25... Lift cylinder 27... Rotating shaft 28... Pumping member 29... Rotating lever 31...・Rotation cylinder

Claims (1)

[Claims] 1. Molten metal is poured into a sand mold formed by combining an upper mold and a lower mold through a funnel-shaped spout that opens on the upper surface of the upper mold, solidified, and then poured into the sand mold. A method for dividing a mold, in which a mold is divided into an upper mold and a lower mold, and the cast body formed in the sand mold is taken out while remaining on the lower mold side, the mold being divided into an upper mold and a lower mold, A method for dividing a mold, which comprises pouring the molten metal and then taking out the molten metal filled in the sprue to the outside by means of pumping the molten metal in the sprue to the outside before the molten metal solidifies.