JPS6335350B2 - - Google Patents

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 collapsed at the same time, so the molding sand forming the mold and the casting are destroyed. There is a problem in that the core sand, which is different from the sand, is mixed, and the quality of the foundry sand changes, resulting in a shortened service life of the foundry sand.

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 a sand mold, as shown in FIG. 4A, a vertical runner 57 that rises vertically from a horizontal runner 58 communicating with a pouring chamber 59 has a vertical runner 57 that expands toward the upper surface 52a of the upper mold 52. A funnel-shaped sprue 54 is formed, and the molten metal is poured from the sprue 54 into the pouring chamber 59 until the surface of the molten metal reaches near the open end of the sprue 54 (in other words, the upper surface 52a of the upper mold 52). As described above, when the funnel-shaped sprue 54 is provided at the upper end of the vertical runner 57 and the molten metal is poured from the sprue 54 and the molten metal is filled up to the inside of the sprue 54, (1) the dynamic pressure of the molten metal during pouring is reduced; (2) Secure the receiving area for the molten metal to simplify the pouring work; (3) Pouring the molten metal using a pouring machine. Effects such as compensating for variations in the amount of molten metal poured when performing molten metal pouring to ensure the required molten metal pouring amount, and (4) realizing continuous molten pouring by absorbing the difference between the molten metal pouring speed and the pouring speed. Therefore, in order to obtain a high quality cast product using a sand mold, the sprue 54 having the above structure is essential.

However, the poured molten metal filled in the sprue 54 solidifies inside the sprue 54 and flows into the vertical runner 57.
After forming the sprue bulge portion 55 having a larger diameter than the vertical runner body 60 formed therein, the mold 51 is divided into an upper mold 52 and a lower mold 53 as shown in FIG. 4B.
When taking out the cast body 56 formed inside the sprue, the sprue bulge 55 gets stuck to the surrounding molding sand and not only obstructs the splitting of the mold 51 but also forces the mold 51 When it is divided, a large amount of molding sand from the upper die 52 remains attached to the lower part of the sprue bulge 55, and this crumbles and falls while the cast body 56 is being transported to the sand removal process, causing problems in the working environment. There is a risk that the sand may deteriorate or be mixed into the core sand during sand removal, leading to a decrease in the quality of the core sand.

(Object 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 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) As a means for achieving the above object, the present invention provides casting using a mold having an upper mold and a lower mold, and further having a funnel-shaped sprue formed in the upper mold. In this method, after pouring molten metal into a mold, before the molten metal solidifies, an appropriate molten metal dividing member is used to separate the molten metal in the funnel-shaped sprue and the molten metal in the runner. It is made to separate into two parts and coagulate the two parts in a mutually separated state. still,
“Molten metal dividing member” as used herein
To explain the terminology, this molten metal dividing member has the effect of dividing the molten metal in the runner and the molten metal in the sprue, which are in a continuous state with each other when the molten metal is poured into the mold. The specific shape and operation thereof will be explained in more detail in the Examples described below.

(Function) In the present invention, by the above-mentioned means, (1) the mold can be 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 obtained that the amount of molding sand that adheres to the casting 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.

1 and 2 show a mold 1 and a device 20 for pushing a molten metal dividing member, which are used to carry out the present invention.

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 10 for forming a casting is provided at the abutment part of the mold 3.
is formed. This pouring chamber 10 is the pouring chamber 1
0, and a vertical runner 12 rising upward from the horizontal runner 11, which communicates with a sprue 13 formed to open on the upper surface 2a of the upper mold 2. The hot water chamber 10, the horizontal runner 11, the vertical runner 12, and the sprue 13 constitute a series of pouring spaces 14). The sprue 13 is formed in the shape of a funnel whose opening area gradually increases from the vertical runner 12 side toward the upper surface 2a of the upper mold 2. This mold 1 is sequentially transported by a transport line (not shown) from a pouring process to a molten metal dividing process equipped with a molten metal dividing member pushing device 20 (described later), and further to a demolding process.

The molten metal dividing member pushing device 20 includes a support 21 that is rotatably supported by a pair of bearings 27 and 28 spaced apart in the vertical direction, and a guide that is attached to the outside of the support 21 so as to be slidable in the vertical direction. Tube 2
2, and an arm 23 attached to the guide tube 22 so as to extend horizontally from the guide tube 22. The lower end portion 21b of the column 21 is chain-connected to a separately installed reversible motor 31, and the column 21 is selectively rotated in the direction of arrow CD by the driving force of the motor 31.
The guide tube 22 is moved up and down by a lift cylinder 29 provided between it and the upper end 21a of the column 21, and is prevented from rotating relative to the column 21 by a rotation preventing member 24 provided on the side surface of the column 21. movement is regulated. Therefore, the arm 23 is moved up and down integrally with the guide cylinder 22 according to the expansion and contraction of the lift cylinder 29, and the arm 23 is moved up and down integrally with the guide cylinder 22.
The rotating force of 1 causes it to rotate integrally with the support column 21. The tip 23a of the arm 23, which moves up and down and pivots, is a fixed clamp member 25 having a gripping surface 25a extending in the vertical direction. Furthermore, the fixed clamp member 25 of the arm 23
A movable clamp member 26 attached to the clamp cylinder 30 is located closer to the proximal end 23b.
is attached with its gripping surface 26a facing the gripping surface 25a of the fixed clamp member 25 so as to be able to move toward and away from it. The fixed clamp member 25 and the movable clamp member 26 form a molten metal dividing member 1 which will be described later.
It constitutes a clamp X that grips 7.

In this embodiment, the molten metal dividing member 17 is a hollow shaft body integrally formed from Schulmold sand, and its inner diameter is smaller than that of the vertical runner 12, and its outer diameter is smaller than that of the vertical runner 12. road 12
The diameter is larger than that of the Therefore, the second
As shown in the figure, when the tip 17a of the molten metal dividing member 17 is pressed against the boundary 16 between the sprue 13 and the vertical runner 12, the vertical runner 12 is pushed into the hole 18 of the molten metal dividing member 17.
It communicates only with the sprue 13, and does not communicate with the sprue 13. That is, the molten metal in the sprue 13 and the molten metal in the vertical runner 12 are separated from each other by the molten metal dividing member 17 .

Next, to briefly explain a method for producing a cast product using the mold 1 and the molten metal dividing member pushing device 20 shown in FIG. Inject the molten metal using. When the pouring operation is completed, the mold 1 is transported by a transport line to a molten metal dividing 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 13 does not solidify.

On the other hand, in the molten metal dividing step, as shown by the solid line in FIG.
However, the arm 23, to which the molten metal dividing member 17 is attached to the clamp X at the tip thereof, is on standby in its upward movement position and in a state where it is swung out toward the conveyance line side. Mold 1 transported by a transport line
However, when it stops at a position directly below the molten metal dividing member 17 in this standby position, the lift cylinder 29
expands and the molten metal dividing member 17 moves downward, so that the tip 17a of the molten metal dividing member 17 reaches the boundary between the sprue 13 and the vertical runner 12, as shown by the chain line (reference numeral 17') in FIGS. Pressed against 16, sprue 13
The molten metal inside and the molten metal inside the vertical runner 12 are separated from each other. At this time, since the molten metal dividing member 17 is a hollow shaft body, the through hole 18 thereof acts as a pressure relief hole, and an increase in the pressure of the molten metal when the molten metal dividing member 17 is pushed is prevented.

When the pushing of the molten metal dividing member 17 is completed, the clamping cylinder 30 contracts to release the gripping action of the molten metal dividing member 17 by the clamp X, and at the same time, the arm 23 moves upward to move the molten metal dividing member 17 into the mold 1.
Leave it as it is pushed to the side (molten metal dividing member 1
Completion of the pushing work in step 7). When the pushing operation of the molten metal dividing member 17 is completed, the arm 23 is rotated in the direction of arrow D to the outside of the conveyance line. After the new molten metal dividing member 17 is attached to the clamp X, the arm 23 is swung out to the conveyance line side again and stands by in preparation for the next molten metal dividing member pushing operation.

On the other hand, the mold sent from the molten metal dividing process to the demolding process is
The molten metal dividing member 17 attached within the sprue 13 is removed. Therefore, inside the mold 1, there is a
As shown in the figure, there is a product body 7 formed by solidifying the molten metal filled in the pouring chamber 10, a horizontal runner body 8 formed by solidifying the molten metal filled in the horizontal runner 11, and a vertical runner 12. A straight rod-shaped vertical runner body 9 is made up of the molten metal filled in the molten metal and the molten metal filled in the 17 through holes 18 attached to the sprue 13, and whose upper end is exposed on the upper surface 2a of the upper mold 2. A cast body 6 is formed which is integrally connected. Further, on the outer peripheral side of the sprue 13, there is a sprue bulge 1 in the shape of a hollow inverted cone, which is made of the molten metal that was filled outside the molten metal dividing member 17.
5 is formed. That is, the sprue bulge 1 is located within the sprue 13 and acts to inhibit the mold from splitting.
5 is formed separately from the cast body 6 formed inside the mold 1. Therefore, when dividing the mold 1 into an upper mold 2 and a lower mold 3, the upper mold 2 and the lower mold 3
Since there is nothing that would impede the separation,
As shown in FIG. 3B, the upper mold 2 hardly loses its shape while leaving the cast body 6 on the lower mold 3 side (in other words, almost all the molding sand of the upper mold 2 remains on the cast body 6 side). It can be easily separated from the lower mold 3 (without any damage).

After separating the upper mold 2 and 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. For,
The quality of the core sand can be maintained well over a long period of time.

In the above embodiment, a hollow shaft was used as the molten metal dividing member 17, but in other embodiments of the present invention, the molten metal dividing member 17 may have a different shape, such as a hollow shaft. However, if the molten metal dividing member 17 is configured as a hollow shaft,
Since unnecessary pressure is applied to the molten metal in the mold 1 when the molten metal dividing member 7 is pushed in, it is preferable that the molten metal dividing member 17 is made into a hollow shaft body to release the pressure during the pushing.

(Effects of the Invention) As is clear from the above explanation, the mold dividing method of the present invention is as follows: (1) The molten metal is filled into the sprue before the molten metal solidifies, and the runner is filled into the runner connected to the sprue. By separating the molten metal from each other, it is possible to prevent the formation of a sprue bulge in the cast body formed in the mold, which acts to inhibit the division of the mold. (2) Since the cast body does not have a sprue bulge that would obstruct the mold division, it will not stick to the cast body when the mold is divided. In particular, in molds equipped with a core, mixing of the core sand and foundry sand is prevented as much as possible to improve the quality of the core sand. It has the effect of being able to be maintained well over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part of a casting apparatus used for carrying out the present invention, FIG. 2 is a diagram of the state in which the molten metal dividing member shown in FIG. 1 is pushed into a mold, and FIGS. FIG. 4A is a vertical sectional view of a conventional mold, and FIG. 4B is a diagram of the mold divided according to the conventional method. 1... Mold, 2... Upper mold, 3... Lower mold, 4, 5... Cast flask, 6... Cast body, 10... Pouring chamber, 11, 12... Horizontal runner, 13... Sprue, 15... Sprue bulge part , 20...
Molten metal dividing member pushing device, 21... Support column, 22... Guide cylinder, 23... Arm, 25... Fixed clamp material,
26... Movable clamp member, 27, 28... Bearing, 2
9...Lift cylinder, 30...Clamp cylinder, 31...Motor, X...Clamp.

Claims (1)

[Claims] 1. In a sand mold formed by combining an upper mold and a lower mold with each other, a runner is located at the upper end of a runner formed to vertically penetrate the upper mold, and on the upper surface of the upper mold. After pouring molten metal through a funnel-shaped sprue configured to open and solidifying it, the upper mold of the sand mold is separated from the lower mold, and the cast body formed in the sand mold is placed on the lower mold side. A method for dividing a mold in which the molten metal is poured into the sand mold, and the molten metal is removed from the top of the runner from above the sprue before the molten metal solidifies. A molten metal separating member that mutually separates the molten metal in the funnel-shaped sprue and the molten metal in the runner is pushed into the sprue of the part, thereby mutually separating the molten metal in the sprue and the molten metal in the runner. A method for dividing a mold, which is characterized by solidifying the mold.