JPH0780628A - Casting method and apparatus - Google Patents

Abstract

PURPOSE:To prevent the defect of internal blowhole caused by solidified shrinkage by turning over a mold, discharging molten metal of a pouring basin, etc., and completing the solidification in the turning-over condition. CONSTITUTION:The pouring basin 2 at the upper part and a feeder head 3 at the lower part of a mold 1 for crank shaft are arranged. The interval between the pouring basin 2 and the feeder head 3 are connected to a sprue 4 and runner 5. A mold cavity 6 is arranged above the feeder head 3. After casting the molten metal into the mold cavity 6, the mold 1 is turned over so as to direct the mold cavity 6 downward during the full solidification of the molten metal in the mold 1. In such a way, the molten metal in the pouring basin 2, sprue 4 and runner 5 is discharged and together with this, the solidification is completed in the turnover condition. Therefore, the feeder head effect can be discharged by positioning the feeder head 3 part having the highest temp. upward. By this method, the still casting can be executed and the entrapment of the oxide, etc., can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting method used for casting a crankshaft or the like, and a casting method suitable for efficiently carrying out the casting method in a production line of a foundry, for example. It is related to the device.

[0002]

2. Description of the Related Art Conventionally, when casting a product having a long and complicated shape such as a crankshaft, for example, a mold as shown in FIG. 5 is used and a molten metal is provided under the mold. I was pouring it up from the road.

That is, the mold 100 shown in the figure is provided with a mold space 101 which is to be a product by casting molten metal in the vertical direction, and a portion where internal cavity defects are most likely to occur
That is, the largest volume 101a of the mold space 101
Is laid out below the mold 100, and the feeder 102 is arranged above the mold space 101.

In this mold 100, the molten metal is the mold 1
00 to the mold space 101
The molten metal can be gently filled in the mold space 101 because it is cast by pushing up from the lower side through the sprue 104 arranged substantially in parallel with and the runner 105 provided in the lower part of the mold 100, and the oxide can be filled gently. It is possible to prevent entanglement.

In addition, using a mold 110 as shown in FIG.
After pouring the water from the hot water reservoir 112 communicating with the mold 110
The mold space 1 by tilting in the direction of the arrow in the figure.
A so-called derbil casting method in which the molten metal is filled in 13 has been put into practical use. Also in this derbil casting method, extremely quiet pouring can be performed by slowing the tilting speed of the mold 110.

[0006]

However, in the casting method shown in FIG. 5, since the molten metal is injected into the mold space 101 from the lower side of the mold 100, the upper part of the mold space 101 ( Large volume portion 101a)
Since the temperature of the molten metal at the lower part is higher than that at the lower part and solidification proceeds from above the mold space 101, there is a problem in that it is not possible to prevent the occurrence of internal cavity defects in the large volume portion 101a.

Further, in the derbil casting method shown in FIG. 6, since the molten metal is cast from the side of the feeder 111, a large volume portion 113a where internal cavity defects are likely to occur is added to the feeder 111.
Although it is possible to substantially prevent the generation of internal cavity defects by arranging the molten metal on the side of, the molten metal is once stored in the molten metal pool 112 and then gradually tilted to inject the molten metal. There is a problem that the temperature is lowered and that productivity is remarkably inferior because man-hours are required for mounting the basin 112 and the like.
In addition, when the pouring temperature is increased in order to cope with the decrease in the molten metal temperature, the oxides increase due to the oxidation of the molten metal, and defects such as inclusions, pinholes and internal cavities due to the increase in the gas amount increase. Problems have arisen, and the solution of these problems has been a problem in casting a product having a long and complicated shape such as a crankshaft.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems in the conventional casting method, and a casting method capable of producing a cast product having a complicated shape without defects and with high efficiency, and An object of the present invention is to provide a casting apparatus that can perform the casting method with high productivity.

[0009]

According to the casting method of the present invention, there is provided a sprue and a runner for connecting a basin provided at an upper portion of a mold with a basin provided at a lower portion of the mold. Through, after casting the molten metal in the mold space arranged above the feeder, until the molten metal in the mold completes the solidification, the mold is turned upside down In this way, the molten metal in the pool, the sprue and the runner can be discharged, and the solidification can be completed in the inverted state. It is used as a means to The casting apparatus according to the present invention is suitable for carrying out the casting method described above, and includes a mold clamping jig for holding a mold and a support for rotatably supporting the mold clamping jig holding the mold. Means, and a conveying means for transferring the mold clamping jig supported by the supporting means,
Pouring means for pouring the molten metal into the mold held by the mold clamping jig at a first predetermined position in the transfer path by the transfer means, and pouring the mold at a first predetermined position in the transfer path Mold posture control means for holding the posture and reversing the poured mold together with the mold clamp jig at the second predetermined position in the transfer path, and the molten metal discharged from the mold by reversing the mold. It is characterized in that it has a configuration including a recovery means for recovering.

[0010]

In the casting method according to the present invention, the molten metal poured from the molten metal pool provided in the upper part of the mold passes through the sprue and runner, passes through the feeder located below the mold, and then the mold above the feeder. It is designed to be cast in a space, and since the molten metal is poured so as to be gently pushed up from the lower side of the mold space, entrapment of oxides etc. does not occur and the temperature drop of the molten metal is extremely high. It will be few. Then, after the pouring is completed, the mold is inverted and solidification proceeds in this state, so that the feeder part with the highest temperature is located above and exerts the feeder effect, resulting in an ideal directional solidification. As a result, the occurrence of internal void defects due to shrinkage during solidification is eliminated.

The casting apparatus according to the present invention includes a mold clamp jig for holding a mold, a supporting means for rotatably supporting the mold clamp jig, a conveying means for transferring the mold clamp jig, and a clamp jig for transferring the mold. The pouring means for pouring the molten metal into the held mold, the mold posture control means for properly holding the posture of the mold during pouring and reversing the mold after pouring together with the clamp jig, and discharging from the mold by reversing Since it has a recovery means for recovering the molten metal, it is suitable for continuously and efficiently carrying out the casting method according to the present invention.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings.

1 to 4 are for explaining one embodiment of a casting method according to the present invention. FIG. 1 is a schematic view showing the shape of a mold used in the casting method, and FIG. It is explanatory drawing which shows the whole structure of a casting apparatus used for implementing a casting method, and a casting procedure.

The mold 1 shown in FIG. 1 is for casting a crankshaft, and a basin 2 is provided on the upper part of the mold 1.
The risers 3 are respectively provided at the lower part, and the pool 2 and the riser 3 are connected by a sprue 4 and a runway 5, and a mold space 6 in the shape of a crankshaft is arranged above the riser 3. The mold space 6 is laid out such that the large volume portion 6a where internal cavity defects are likely to occur is located on the lower side, that is, on the feeder 3 side.

The casting apparatus 10 shown in FIG. 2 has a structure to be described later, and the casting mold 1 carried in by the belt conveyor 11 is used.
A mold clamp jig 12 for holding the mold 1, a rail 13 as a support means for rotatably supporting the mold clamp jig 12 in a state of holding the mold 1, and the mold clamp jig 12 supported on the rail 13. A chain conveyor 14 (see FIG. 3) as a transporting means for transporting along the rail 13 and a first predetermined position in the transport path by the chain conveyor 14, that is, a symbol C from the position indicated by symbol B in FIG. Up to the position shown, the mold clamp jig 12
It is equipped with a ladle 15 as a pouring means for pouring the molten metal into the mold 1 held by.

Further, the casting apparatus 10 is provided with guides 16 and 17 as mold posture control means along the transfer path of the mold clamp jig 12, that is, the rail 13, and is provided in the mold clamp jig 12. By engaging the pins 12a and 12b with the guides 16 and 17, respectively, the posture control is performed so that the clamp jig 12 faces a predetermined direction at a predetermined position as the chain conveyor 14 moves. It is supposed to be done. That is, the mold clamp jig 1
2 is held at the pouring position at the position between symbols B and C in FIG. 2, that is, at the position where the molten metal pool 2 of the mold 1 is upward, and at the position between symbols C and D, the mold space 6 of the mold 1 is on the lower side. After being reversely driven in the counterclockwise direction in the figure, the position between the symbols DE is reversed, that is, the molten metal pool 2 of the mold 1 is at the lower side and the feeder 3 is held at the upper position. It has become so.

The casting apparatus 10 further includes a well-meaning rail 1
Underneath 3, the bucket conveyor 1 receives the molten metal discharged from the molten metal pool 3 and the sprue 4 of the mold 1 by reversing the mold 1.
8 and a scrap box 19 for storing the scrap S in which the molten metal is solidified in the bucket conveyor 18, and these constitute a molten metal recovery means.

At the right end of the casting apparatus 10 in the figure, that is, at the unloading side, the product conveying vibration for paying out the crankshaft P solidified into a product together with the unmolded mold 1 to the next step. A conveyor 20 is provided.

As shown in the enlarged view of FIG. 3, the mold clamping jig 12 has a fixed clamp plate 22 and a cylinder fixed plate 23 which are erected on a substrate 21 so as to face each other, and also the cylinder fixed plate 23. A clamp cylinder 24 is attached to the clamp cylinder 24, and a movable clamp plate 25 is fixed to a cylinder rod 24a of the clamp cylinder 24. By the pushing operation of the clamp cylinder 24, the fixed clamp plate 22 and the movable clamp plate 25 are separated from each other. In between the mold 1
It is a mechanism to sandwich.

Shafts 22a and 23a are fixed to the fixed clamp plate 22 and the cylinder fixing plate 23 at substantially the center of gravity of the mold clamping jig 12, and the shaft 22 is also fixed.
Rollers 26 and 27 are rotatably attached to a and 23a, respectively, and the mold clamping jig 12 is the roller 2
It is supported by the rail 13 via 6, 27. The chain conveyor 14 presses the shafts 22a and 23a to move the mold clamping jig 12 in the right direction in FIG.

An arm 28 having pins 12a and 12b at both ends is fixed to the tip of the shaft 23a, and the pins 12a and 12b are connected to the guides 16 and 17, respectively.
By engaging with, the posture of the clamp jig 12 at each position during transfer is controlled.

The procedure for casting a crankshaft using the casting apparatus 10 and the mold 1 will be described below in order.

First, at the position indicated by the symbol A in FIG.
Is inserted into the mold clamp jig 12, and the clamp cylinder 2
The mold 1 is clamped between the clamp plates 22 and 25 by an extrusion operation of 4. At this time, the upper pin 12a of the two pins 12a and 12b of the mold clamping jig 12 engages with the guide 16.

Then, a clamp jig 12 holding the mold 1 therebetween.
While being supported by the rail 13, the chain conveyor 14
When it is transferred to the position indicated by symbol B by
a is guided by the guide 16 and moves upward,
The clamp jig 12 rotates to a position where the molten metal pool 2 of the mold 1 is located above, and is held in this posture until the position shown by the symbol C is reached. During this time, the ladle 15 that moves together with the clamp jig 12 is used. The molten metal is cast into the mold space 6 of the mold 1.

At this time, as shown in FIG. 4 (a), the molten metal passes from a pool 2 arranged in the upper part of the mold 1 through a spout 4 formed substantially parallel to the mold space 6 and then to the lower part of the mold 1. Since it is gently injected from the lower side into the mold space 6 through the runner 5 and the riser 3 provided in the above, the inclusion of oxides does not occur and the temperature drop of the molten metal is minimal. Becomes

When pouring into the mold 1 is completed and the clamp jig 12 passes through the position C, the pin 12a of the clamp jig 12 is guided by the guide 16 and moves downward. The tool 12 starts inverting in the counterclockwise direction in the figure with the mold space 6 of the mold 1 facing downward. Then, in the reversing process, the upper pin 12a of the clamp jig 12 is disengaged from the guide 16, while the lower pin 12b of the clamp jig 12 is engaged with the other guide 17 to cause the clamp jig 12 to move. When reaches the position indicated by the symbol D, it is completely inverted by 180 °, and the feeder 3 of the mold 1 is positioned above.

In this reversing process, as shown in FIG. 4B, the unsolidified molten metal in the pool 2, the spout 4 and the runner 5 of the mold 1 is discharged from the mold 1 and the bucket conveyor 18
Since it is collected in the scrap box 19 by removing it from the product, it is not necessary to separate the part corresponding to the sprue from the product after the mold is removed, and the bulk density of the scrap is increased and the melting efficiency at the time of remelting is improved. It will also be possible to obtain secondary effects.

The mold clamping jig 12 is held in the inverted state until the position indicated by the symbol E is reached, and solidification proceeds during this period.
As shown in (c), since the part of the feeder 3 having the highest molten metal temperature is located above and exerts a feeder effect, ideal directional solidification is obtained and a sound product without internal cavity defects. The crankshaft P can be obtained.

When the mold clamp jig 12 reaches the end of the transfer path, that is, the position indicated by the symbol F in FIG. 2, the clamp cylinder 24 of the clamp jig 12 pulls in the mold 1 so that the mold 1 is clamped. Since the mold 1 is released, the mold 1 drops onto the vibrating conveyor 20 via the chute 21, and the product crankshaft P separated from the mold 1 is carried out to the next step, where finishing treatment such as cutting of the feeder is performed. Is given.

[0030]

As described above, the casting method according to the present invention has the above-described structure, that is, the mold is inverted after the metal is pushed up from the side of the feeder located below the mold space. Therefore, it is possible to perform quiet casting, prevent the inclusion of oxides, etc., and since the riser part with the highest temperature will be located above the mold space by reversing the mold, ideal directivity This brings about an extremely excellent effect of being able to prevent solidification and internal defect caused by solidification shrinkage. Further, the casting apparatus according to the present invention, in particular, holds the mold clamping jig holding the mold rotatably, together with the supporting means and the transferring means for transferring the mold, at the first predetermined position in the transfer path, the pouring position of the mold. The casting method according to the present invention is continuously and smoothly performed by holding the casting method according to the present invention. In addition, it has an extremely excellent effect that it can be carried out efficiently.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing the shape of a mold used in an example of a casting method according to the present invention.

FIG. 2 is an explanatory view showing a casting apparatus and a casting procedure used in one embodiment of the casting method according to the present invention.

3 (a) and 3 (b) are a front view and a side view showing a structure of a mold clamp jig of the casting apparatus shown in FIG.

4 (a), (b) and (c) are process explanatory views showing the points of the casting procedure shown in FIG.

FIG. 5 is a schematic explanatory view showing a conventional method for casting a crankshaft.

FIG. 6 is a schematic explanatory view showing a casting procedure of a conventional crankshaft by the derville casting method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mold 2 Hot water pool 3 Feeder 4 Gate 5 Spout 6 Mold space 10 Casting device 12 Mold clamp jig 13 Rail (supporting means) 14 Chain block (transporting means) 15 Ladle 16 and 17 Guide (molding attitude control means) 18 Bucket conveyor (collection means) 19 Scrap box (collection means)

Claims (3)

[Claims] 1. Arranged above the riser via a sprue and runner that connect the basin provided at the top of the mold to the riser provided at the bottom of the mold. After casting the molten metal in the mold space, by the time the molten metal in the mold completes the solidification, by inverting the mold with the mold space facing downward, the pond, sprue and runner A casting method, characterized in that the molten metal is discharged and solidification is completed in the inverted state. 2. The casting method according to claim 1, wherein a portion of the mold space where internal cavity defects are likely to occur is located on the feeder side. 3. A mold clamp jig for holding a mold, a support means for rotatably supporting the mold clamp jig for holding the mold, and a transfer for transferring the mold clamp jig supported by the support means. Means, pouring means for pouring the molten metal into the mold held by the mold clamping jig at the first predetermined position in the transfer path by the transfer means, and the mold at the first predetermined position in the transfer path While maintaining the pouring position in the pouring position, and at the second predetermined position in the transfer path, the pouring position control means for reversing the pouring mold together with the mold clamping jig; A casting apparatus comprising recovery means for recovering molten metal.