KR20100099085A - Centrifugal casting method of ring - Google Patents

Abstract

PURPOSE: A ring centrifugal casting method which inserts molten metal into a molten metal feed hopper on a mold upper side is provided to improve mechanical property by making a structure dense by using centrifugal force generated when a molten metal is injected to a molten metal feed hopper. CONSTITUTION: A ring centrifugal casting method comprises a mold table(28). The molten metal is inserted to a molten metal feed hopper(33) of an upper mold(32). An upper mold clamp tool(46) descends and ascends after clamping the upper mold. An upper mold transporter(41) horizontally moves. The product clamp tool descends and a product is unclamped in the conveyer upper side for shipment. The products are shipped with the conveyer for shipment to outside.

Description

CENTRIFUGAL CASTING METHOD OF RING}

The present invention relates to a centrifugal casting method for manufacturing various ring-shaped products by centrifugal casting, and more specifically, to various flange-shaped products used for pipe joints in industrial sites and propeller parts for wind power generation. The present invention relates to a ring centrifugal casting method provided with a molten metal injection device, a centrifugal casting mold device, and a transfer device for manufacturing.

In general, ring-shaped products such as various flanges used in the industrial field are manufactured as semi-finished products by forging or casting, and then machined into desired shapes and dimensions to be used as final products.

    Forging is a method of manufacturing a certain shape by a mechanical method of tapping or pressing a solid metal material with a hammer or the like and is divided into cold forging and hot forging.

In the method of manufacturing various ring-shaped products by forging, the plate is cut into a circular ring shape and then forged into a desired shape to complete the product by final machining. Therefore, when manufacturing a ring-shaped product by forging, the loss of materials is large, the work time is also required, the productivity is greatly reduced.

    Casting is a product made by injecting and solidifying molten metal, molten metal, using gravity, pressure, and centrifugal force into a mold capable of withstanding molten metal, molten metal. The method used for casting is classified according to the metal used, the type of mold, and the method of introducing molten metal into the mold.

Castings are classified into cast iron castings, aluminum alloy castings, and copper alloy castings, depending on the metal used, and are classified into sand castings, mold castings, shell molds, etc., depending on the material of the mold. In addition, according to the method of injecting molten metal, which is a molten metal, into a mold, gravity casting using gravity, die casting, which presses the molten metal into a mold, and injects molten metal into a rotating mold to increase the centrifugal force of the mold. It is classified into centrifugal casting and the like for casting a product by using.

 In general, as a casting method used to manufacture a ring-shaped product, mold casting, sand casting, and the like are used as gravity casting. However, mold casting or products produced by sand casting have bubbles inside, and the structure is not dense, which causes weak strength, and sand casting is not suitable for mass production. In addition, there are various casting defects such as cracks due to volume reduction during solidification, and the productivity is significantly reduced.

Therefore, the present invention has been made to solve the above problems, the present invention is to produce a variety of ring-shaped products that are commonly used in the industrial field, the loss of material and the productivity that occurs during forging and It is to provide a ring centrifugal casting method in which various casting defects are improved upon casting.

The present invention relates to a ring centrifugal casting method, wherein in the ring casting method, the casting method is a centrifugal casting method, which rotates the centrifugal casting die 30 while the mold table 28 of the ring centrifugal casting apparatus rotates. step; Injecting molten metal into the molten metal inlet of the upper mold while the molten metal is discharged from the molten metal injection device 10; It is characterized in that it comprises a; step of performing centrifugal casting while the molten metal is injected into a rotating mold.

Therefore, according to the present invention, various ring-shaped products are manufactured by the ring centrifugal casting method to prevent material loss and casting defects from occurring, and mass production is also possible, which significantly improves productivity.

1 is a front view of the present invention centrifugal casting apparatus
Figure 2 is a side view of the present invention centrifugal casting apparatus
Figure 3 is a plan view of the present invention centrifugal casting apparatus
Figure 4 is a detailed view of the upper mold transfer device of the present invention centrifugal casting apparatus
Figure 5 is a front view of the centrifugal casting mold apparatus of the present invention centrifugal casting apparatus
Figure 6 is a front view of the molten metal injection device of the present invention centrifugal casting apparatus

The present invention relates to a ring centrifugal casting method, wherein in the ring casting method, the casting method is a centrifugal casting method, which rotates the centrifugal casting die 30 while the mold table 28 of the ring centrifugal casting apparatus rotates. step; Injecting molten metal into the molten metal inlet 33 of the upper mold 32 while the molten metal is discharged from the molten metal injection device 10; It is characterized in that it comprises a; step of performing centrifugal casting while the molten metal is injected into a rotating mold.

In addition, the ring centrifugal casting method includes the step of raising the upper mold clamping mechanism 46 is lowered after clamping the upper mold; The upper mold feeder 41 moves horizontally; The product clamping mechanism 49 is lowered to take out the product from the lower mold 31 and then clamp and ascend; The product conveyer 42 moves horizontally over the shipping conveyor 50 and then the product clamping mechanism 49 is lowered to unclamp the product on the shipping conveyor upper surface; It characterized in that it further comprises the step of the product is shipped to the outside by the shipment conveyor (50).

The centrifugal casting method for producing various ring-shaped products of the present invention by centrifugal casting will be described with reference to the drawings.

1 is a front view of the present invention centrifugal casting apparatus, Figure 2 is a side view of the present invention centrifugal casting apparatus. 3 is a plan view of the centrifugal casting apparatus of the present invention. Figure 4 is a detailed view of the upper mold transfer device of the present invention centrifugal casting apparatus, Figure 5 is a front view of the centrifugal casting mold apparatus of the present invention centrifugal casting apparatus, Figure 6 is a front view of a molten metal injection device of the present invention centrifugal casting apparatus.

Centrifugal casting apparatus of the present invention is a molten metal injection device 10 for moving the molten metal molten metal in the melting furnace to supply a fixed amount to the centrifugal casting mold, and a centrifugal casting mold formed in the lower portion of the molten metal injection device, the cooling means ( 30) is provided on the centrifugal casting mold apparatus 20 for manufacturing a product by centrifugal casting, and the upper mold (32) from the centrifugal casting mold of the centrifugal casting mold apparatus 20, the upper mold (32) ) Is removed and the product placed in the lower mold 31 is removed and moved to the transfer device 40 and formed on one side of the centrifugal casting mold device, and the product moved to the transfer device is shipped to the outside of the centrifugal casting device. It is formed is divided into a shipping conveyor (50).

     The molten metal injection device 10 is formed on top of the centrifugal casting mold apparatus 20 and supplies the quantitatively to the centrifugal casting mold 30 which rotates by moving the molten metal in the melting furnace. A ladle 11 for moving the molten metal is formed, and a hopper 12 for pouring molten metal is formed under the ladle. The upper end of the hopper is located under the ladle 11 and the lower end is located above the molten metal inlet 33 of the metal mold 30 for centrifugal casting. Therefore, the molten metal moved to the ladle is introduced into the centrifugal casting mold through the hopper. Ladles and hoppers can be applied to those used in general industrial sites.

    The centrifugal casting mold apparatus 20 is horizontally spaced apart from the ground by a structure and has a base 21 having a circular hole in the center, and a fixed shaft divided into an upper shaft, an intermediate shaft, and a lower shaft in the form of a fixed shaft. 22 is installed and fixed in a vertical direction through a circular hole formed in the center of the base 21. The upper shaft of the fixed shaft 22 protrudes on the upper surface of the base, and the intermediate shaft is formed with a flange to be fixed to the base 21 as the protruded surface of the flange, and the lower shaft is positioned below the base and faces the ground. In addition, a cooling water circulation hole 24, which is a cooling water circulation passage 24 in the longitudinal direction of the fixed shaft, is formed at the upper end of the fixed shaft 22 in a long hole shape, and a cooling water inlet 27 is installed at the lower end of the fixed shaft.

The mold table 28 adjacent to the upper part of the base 21 and connected to the upper shaft of the fixed shaft and the bearing in a circular table shape and rotates horizontally is provided. A driven gear 25 is formed on the lower surface of the mold table, and a drive gear 26 that rotates by a motor and a transmission as driving means is formed adjacent to the mold table. In addition, the driving gear and the driven gear are meshed so that the mold table 28 that receives the rotational force is rotated.

In addition, the lower mold 31 and the upper mold 32 are formed horizontally on the upper surface of the mold table 28. The centrifugal casting mold 30 is horizontally installed. It rotates horizontally and a casting space is formed inside. A circular molten metal inlet 33 is formed at the center of the outer upper surface of the mold 30 for centrifugal casting, and a casting space in which the product is manufactured by centrifugal casting is formed therein. The casting space upper part and the molten metal inlet communicate with each other.

The lower mold 31 mounted on the upper surface of the mold table 28 is formed by dividing the bottom surface and the side surface, and the bottom surface is in the form of a horizontal plate installed horizontally, and the side surface is vertical to the circular edge of the bottom surface and is infinite. It is formed into an orbit.

’형상으로 형성된다.
And the bottom surface is formed in the shape of a band in the horizontal direction from the circular border to the center portion, the center surface is protruding convexly in a circular shape, and the inclined surface connecting the inclined surface between the convex center on the bottom surface and the horizontal surface in a band shape. Is formed. In addition, a convex molten valley is formed in a smooth valley shape at the connection portion between the horizontal plane and the inclined plane. Therefore, the cross section of the bottom mold bottom is'

'Is formed into a shape.

In addition, the horizontal surface width of the bottom surface is formed larger than the thickness of the ring, the product, the inclined surface is formed to be inclined at about 30 ° to 40 °. The molten bone is injected into the molten metal inlet 33 of the rotating centrifugal casting mold 30, and then the molten metal passes through the molten bone after passing through the inclined surface of the lower mold and then into the horizontal surface. It is smoothly converted into the upward kinetic energy to prevent bubble generation. The molten bone is divided into the inflow surface connected to the inclined surface and the outflow surface connected to the horizontal surface, and the angle formed between the inflow surface and the horizontal surface is connected so that the extension line is connected to the upper corner of the casting space when the melt flow surface is virtually extended. The molten metal inlet and the inclined surface are formed to be smoothly connected.

’형상으로 측벽 상단 내측에 돌출부가 형성된 형태이다.
And the sides are formed perpendicular to the floor in the form of circular sidewalls, the top of the sidewalls being '

'In the shape of a protrusion formed inside the upper side wall.

’형상이고, 상부금형의 측벽과 하면 테두리의 단면은 ‘

’형상이다. 따라서 상부금형 하면의 수평부위와 하부금형의 바닥면 수평부위 및 하부금형의 측면이 만드는 공간이 주조공간으로 구비된다. 그리고 상부금형 하면에는 테두리에 인접하여 오목한 형상의 용탕 피난구가 형성된다. 상기 용탕 피난구는 하부금형 측벽 돌출부의 상부에 형성되되, 주조공간과 연통되게 한다. 또한 하부금형 측벽 끝단에 돌출부 재질의 팽창계수가 타부분 재질의 팽창계수보다 큰 재질을 사용하여 용탕이 투입되어 금형 온도가 상승 시 하부금형의 돌출부가 타부분 보다 더욱 팽창하여 하부금형의 측벽과 하면에 밀착되면서 상,하부 금형을 완전히 밀폐시켜 용탕이 누출되는 것을 방지하는 구조로 형성된다.
The upper mold 32 is provided in a shape corresponding to the lower mold, the molten metal inlet 33 is formed to protrude in a circular shape in the center of the upper mold, the lower surface is formed in parallel to the horizontal surface and the inclined surface of the lower mold bottom surface. In addition, the center of the upper mold corresponding to the protruding surface on the center of the lower mold is formed as a molten metal inlet. And the side wall and the lower edge is formed to correspond to the upper end of the side wall of the lower mold. In other words, the cross section of the upper side of the lower mold

"The shape of the cross section of the side wall and the lower edge of the upper mold"

'Shape. Therefore, the space formed by the horizontal part of the lower surface of the upper mold and the horizontal part of the bottom surface of the lower mold and the side of the lower mold is provided as a casting space. And the lower surface of the upper mold is formed with a concave molten escape hole adjacent to the rim. The molten metal evacuation port is formed on an upper portion of the lower mold sidewall protrusion to communicate with the casting space. In addition, when the melt temperature is applied to the lower mold sidewall end by using a material whose expansion coefficient is larger than that of other materials, when the mold temperature rises, the protrusion of the lower mold expands more than the other parts, so that While being in close contact with the upper and lower molds are completely sealed to form a structure to prevent the leakage of the melt.

Therefore, when the molten metal is injected into the molten metal inlet 33 of the rotating centrifugal casting mold 30, the molten metal is introduced into the casting space along a gentle slope of about 30 ° to 40 ° formed on the bottom surface of the lower mold and then into the molten bone. As it passes through, the downward kinetic energy of the molten metal is smoothly converted into upward kinetic energy, and bubbles are prevented from coming into contact with the upper side of the casting space sidewall. Then, the foreign matter, gas, etc. contained in the molten metal exits the molten metal evacuation hole formed in the upper mold rim, and the lower mold sidewall protrusion is expanded to seal the casting space. Then, centrifugal casting is performed to produce various ring-shaped products by centrifugal force.

In addition, a plurality of heat sinks vertically formed on the upper surface of the upper mold 32 is radially installed, and the centrifugal casting mold 30 is formed in a structure that increases cooling efficiency by air cooling when rotating. In addition, the lower mold 31 has a space except a part of the edge to form a convex upward direction, and a space is formed inside the side wall to communicate with each other to be used as the cooling water circulation space 34.

In addition, in order to prevent the inner surface of the lower mold from being damaged by the melt pressure when the molten metal is injected into the molten metal inlet of the upper mold, a lower mold protector may be installed to protect the sidewall and the bottom surface. The protector is installed in contact with the bottom surface and the bottom of the lower mold in a form that can be replaced periodically when the damage is injected as the molten metal is injected. The mold protector can be installed using aluminum oxide, refractory brick or the like.

In addition, the tightening direction of the bolt or nut used to mount the lower mold 31 on the upper surface of the mold table 28 is opposite to the direction in which the centrifugal casting mold rotates to prevent the centrifugal casting mold from loosening when rotating. .

In addition, the lower mold 31 for centrifugal casting is fixed to the upper surface of the mold table 28, and a cooling water circulation space 34 connected to the inner surface of the lower mold sidewall is formed on the upper surface of the mold table 28 and the lower mold 31. . In addition, the outer surface of the lower mold side wall is formed with several discharge holes connected to the cooling water circulation space 34. And the discharge hole is connected to the cooling water outlet 35 is rotated with the centrifugal casting mold. In addition, the bottom of the outlet is adjacent to the mold table, the drip tray is installed in the endless track and collects the cooling water discharged from the rotating outlet to flow into the cooling tank.

Therefore, the cooling water inlet 27 installed at the lower end of the fixed shaft 22, the cooling water circulation hole 24 formed inside the fixed shaft, the cooling water circulation space 34 formed at the lower mold lower surface and the cooling water outlet formed at the outer surface of the lower mold sidewall ( 35) are sequentially connected to the cooling water is circulated to cool the centrifugal casting mold. The cooling water is discharged to the cooling water outlet 35 after cooling the mold and the product for centrifugal casting, and flows into the cooling tank through the drip tray. Since the drip tray and the cooling tank are generalized technologies, detailed descriptions are omitted.

The cooling water discharged after cooling the casting die is steam at a high temperature and high pressure of 350 ° C or higher. Therefore, a steam turbine is installed below the cooling water discharge line in order to efficiently use the high temperature and high pressure cooling water. And it can be installed by adding a renewable energy device that generates electricity by rotating the steam turbine with high-pressure steam, or reused as power for rotation.

Therefore, the centrifugal casting mold apparatus 20 is completed with the above configuration.

The conveying device 40 is divided into an upper mold conveying machine 41 and a product conveying machine 42 which linearly reciprocate along a rail formed horizontally on an upper portion of the centrifugal casting mold apparatus 20, and the upper mold conveying device. The machine is formed on the upper mold 32, the upper mold clamping mechanism 46 for clamping the upper mold while repeatedly raising and lowering, and the upper mold vertical transfer mechanism 43 and the upper mold for moving the upper mold clamping mechanism up and down. It is formed to include the upper mold horizontal transfer mechanism 44 for moving the clamp mechanism horizontally, the product feeder 42 is formed in the upper mold upper to take out and move the product from the lower mold while repeating the rising and falling Product clamp mechanism 49 for clamping the product, product vertical transfer mechanism 47 for moving the product clamp mechanism up and down, and product clamp mechanism for horizontally moving the upper part of the conveyor for shipment Flat is formed, including a feed mechanism (48).

In addition, it is preferable that the clamp mechanism, the vertical transfer mechanism, and the horizontal transfer mechanism of each of the transfer devices are operated by a hydraulic cylinder or a pneumatic cylinder.

Therefore, the transfer apparatus is completed with the above configuration.

The product shipment conveyor 50 is installed adjacent to the centrifugal casting mold apparatus to move the product transferred to the product conveying apparatus to the conveyor. Conveyor for product shipment is already a common technique, so detailed description thereof will be omitted.

Referring to the centrifugal casting apparatus according to the present invention constituted as described above to produce a product as follows.

Rotating the centrifugal casting mold 30 while the mold table 28 rotates at an appropriate rotational speed, the molten metal is injected into the molten metal inlet of the upper mold while the molten metal is discharged from the molten metal injection device 10, and the molten metal is rotated. The centrifugal casting is carried out while being injected into the mold, and the coolant circulates through the cooling water circulation hole 24 and the cooling water circulation space 34 at the same time as the preliminary step. The lower step of clamping the upper mold and then ascending, the upper mold feeder 41 is moved horizontally, the product clamp mechanism 49 is lowered to take out the product from the lower mold and then the clamping and ascending, the product After the feeder 42 moves horizontally above the shipping conveyor 50, the product clamping mechanism 49 descends to unclamp the product on the shipping conveyor upper surface, the shipping conveyor In step 50, the product is shipped outward.

Therefore, when various ring-shaped products are manufactured by centrifugal casting with the above structure, products having excellent structure and compact mechanical properties are cast by centrifugal force.

The ring-shaped cast product manufactured by centrifugal casting is used as a finished product such as various flanges used as pipe joints and parts of wind power propellers, and is also manufactured as a semi-finished product for manufacturing various ring-shaped products. Ring-shaped cast products are processed into desired shapes and dimensions through forging and machining, and then used as final parts.

    Therefore, when the molten metal is injected into the molten metal inlet formed on the top surface of the centrifugal casting mold while the centrifugal casting mold is rotated at an appropriate rotational speed, a product having a fine structure and excellent mechanical properties is cast. In addition, when the mold and the product for centrifugal casting are cooled by the cooling means at the same time as the centrifugal casting, the cast product is completed almost close to the desired shape and dimensions, thereby reducing the amount of machining.

    In addition, the temperature of the molten metal introduced into the molten metal inlet is appropriately maintained at 1400 ° C to 1800 ° C, and the temperature of the centrifugal casting mold is preferably maintained at 350 ° C to 450 ° C. And the rotation speed is initially started centrifugal casting at 50rpm and maintained at the highest 1000rpm during centrifugal casting.

10: molten metal injection device 11: ladle
12: Hopper 20: mold apparatus for centrifugal casting
21: base 22: fixed shaft
24: cooling water circulation hole 25: driven gear
26: drive gear 27: coolant inlet
28: mold table 30: centrifugal casting mold
31: lower mold 32: upper mold
33: molten metal inlet 34: cooling water circulation space
35: cooling water outlet 40: transfer device
41: upper mold feeder 42: product feeder
43: upper mold vertical feed mechanism 44: upper mold horizontal feed mechanism
45: upper mold pressing mechanism 46: upper mold clamping mechanism
47: Vertical feed mechanism 48: Horizontal feed mechanism
49: product clamp mechanism 50: shipment conveyor

Claims (2)

In the ring casting method, the casting method is a centrifugal casting method, the step of rotating the centrifugal casting mold 30 while the mold table 28 of the ring centrifugal casting apparatus rotates; Injecting molten metal into the molten metal inlet 33 of the upper mold 32 while the molten metal is discharged from the molten metal injection device 10; Centrifugal casting is performed while the molten metal is injected into a rotating mold.
The method of claim 1, wherein the ring centrifugal casting method comprises the steps of: lowering the upper mold clamping mechanism (46) to raise and then clamp the upper mold (32); The upper mold feeder 41 moves horizontally; The product clamping mechanism 49 is lowered to take out the product from the lower mold 31 and then clamp and ascend; The product conveyer 42 moves horizontally over the shipping conveyor 50 and then the product clamping mechanism 49 is lowered to unclamp the product on the shipping conveyor upper surface; Ring centrifugal casting method characterized in that it further comprises the step of shipping the product to the outside by the shipment conveyor (50).

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