CN202517011U - Water-cooling casting device for hollow pipe blank - Google Patents

Abstract

The utility model relates to a hollow tube billet water-cooled casting device, comprising: a cylindrical water-cooled outer metal mold, a cylindrical water-cooled inner metal mold arranged inside, and an annular casting cavity formed between the water-cooled inner and outer metal molds; The top of the water-cooled outer metal mold and the water-cooled inner metal mold is provided with a riser mold; the water-cooled bottom box is arranged at the lower part of the outer metal mold and the inner metal mold, and the molten metal enters the mold cavity from the gate through the water-cooled bottom box ; Wherein, the gate is a tangential horizontal gate, and the molten metal enters the water-cooled bottom box tangentially from the gate, and the molten steel is driven from the bottom of the cavity by means of the promotion of the exit speed of the tangential horizontal gate. It rises in a circular rotation mode; the longitudinal section shape of the water-cooled outer metal mold and the water-cooled inner metal mold is a metal mold with a thin top and a thick bottom with a taper, and the solidification time of the molten metal at the top of the cavity is delayed compared with that at the bottom, By controlling the adjustment of the height of the cooling water level, the sequential cooling of the molten metal from bottom to top is realized, which improves the quality of the finished product.

Description

Water-cooled casting device for hollow billets

technical field

The utility model relates to a casting device for a hollow billet, in particular to a water-cooled casting device for a hollow billet, which relates to the preparation of blanks in the technical fields of metallurgical pipe making and mechanical manufacturing and ring making; especially relates to the water-cooled casting of a super-large hollow billet technology field. the

Background technique

With the development of the national economy, the demand for large thick-walled seamless steel pipes and large thick-walled rings (heavy machinery bearing rings, wind power support rings, ring gears, etc.) continues to increase. In the past, the traditional manufacturing process usually used casting large solid ingots ( Blank) → realize the processing of the product blank by punching → reaming → forging. In recent years, with the continuous innovation of technology and supporting technology, especially large-scale and super-large-scale pipe and ring parts, a new process method has emerged: hollow ingot → hollow forging → finished product processing; the products produced by this method High quality (after forging), short process (simplifies punching and piercing), and is being promoted rapidly. the

Existing hollow casting technology: including centrifugal casting method, static sand core casting method, air-cooled steel core casting method and hollow tube continuous casting method. the

The centrifugal casting method has the advantages of fine and dense outer structure of the casting, simple process, and high yield of the casting. However, there are slag inclusions, shrinkage cavities, and loose layers within the range of 10 to 40 mm on the inner surface. Therefore, mechanical casting must be carried out in a cold state after casting. The method of processing is used for processing, and the investment of centrifuge equipment is high at one time. the

The static sand core casting method has a small investment and simple process, but when the casting is cooled, the cooling rate of the outer surface is much faster than that of the inner surface, that is, the outer surface of the casting solidifies faster than the inner surface. Figure 9 schematically shows the static sand core casting method. The CAE simulation results of the solid phase fraction change during the solidification process of the casting manufactured by the core casting method. The five figures a, b, c, d, and e respectively represent the different stages of the casting. In the figure, the light-colored area represents the unsolidified area A1, and its The dark area of , represents the solidified layer B1. It can be clearly seen from the figure that when using this method to manufacture hollow tube castings, the outer surface solidifies first, and the inner surface solidifies last, that is, Figure 9a shows the beginning of solidification, Figure 9b shows the initial stage of solidification, Figure 9c shows the middle stage of solidification, and Figure 9d is In the late stage of solidification, Fig. 9e is the end (all solidified), and the change process of the molten metal (unsolidified region A1) and the solidified layer B1 is shown through each figure. As shown in Figure 9c, at this stage the inner surface of the hollow tube is still not solidified (there is a light-colored non-solidified region A1), and the molten metal is completely solidified from Figure 9d to Figure 9e, that is, the inner surface C of the hollow tube, and Top area D is the final freezing zone. The characteristics of this method are: the liquid core is narrow and deep in the later stage of solidification, so it is prone to poor feeding, which makes the inner surface structure of the casting relatively large, and there will be a layer on the inner surface close to the sand core, which is easy to form during the forging heating process. Oxidation is difficult to remove the loose layer, and for products with harsher service conditions, the inner surface needs to be treated first. the

The air-cooled steel core casting method is currently used more at home and abroad. It is relatively mature in the manufacture of large hollow steel ingots with short machines. Porosity occurs, as shown in Figure 10, which is a schematic diagram of the CAE simulation results of the solid phase fraction change of the casting manufactured by the air-cooled steel sleeve casting method during the solidification process, and the five figures a, b, c, d, and e respectively represent different stages of the casting, In the figure, the light-colored area represents the unsolidified area A2, and the dark-colored area outside it represents the solidified layer B2. That is, Fig. 10a is the beginning of solidification, Fig. 10b is the initial stage of solidification, Fig. 10c is the middle stage of solidification, Fig. 10d is the later stage of solidification, and Fig. 10e is the end (full solidification), and the molten metal (finally solidified region A2) and the solidified state are shown by each figure. The change process of layer B2. It can be clearly seen from the figure that the air-cooled steel core casting method also has the above-mentioned problems of the static sand core casting method. There will be secondary shrinkage holes, and this method needs to make a steel plate that is directly in contact with the molten steel and melt it into the casting each time it is manufactured. the

Hollow tube continuous casting method, including vertical hollow tube continuous casting method and horizontal hollow tube continuous casting method. For the preparation of tube blanks, due to technical reasons and other reasons, the current method is limited to the production of small cast tubes with a smaller outer diameter of Φ500mm or less and a thinner wall thickness of less than 100mm. The production efficiency is high and the investment in equipment is large. the

In order to find a method for manufacturing thick-walled tube blanks suitable for large specifications (diameter ≥ 1000-2000mm, wall thickness ≥ 300-600mm, height ≥ 2000-6000mm), the inventors of the utility model combined years of experience in casting and processing to develop this product. The utility model hollow tube billet water-cooled casting device adopts a metal mold with a thin top and a thick bottom and a variable thickness metal mold, and adds a thick and thin and variable thickness coating on the inside of the metal mold, and uses the water-cooled forced sequential cooling technology to control the water-cooling sequence (by Gradually advance from bottom to top) to achieve the purpose of improving sequential solidification, completely eliminating shrinkage cavities, and loosening and refining the structure. the

Utility model content

The purpose of the utility model is to provide a hollow billet casting device, especially a hollow billet water-cooled casting device, which utilizes a metal mold with a thinner top and a thicker lower bottom, and controls the water cooling sequence (progressively from bottom to top), To achieve the purpose of improving sequential solidification, completely eliminating shrinkage cavities, and loosening and refining tissues. the

The utility model proposes a water-cooled casting device for a hollow tube billet, comprising: a cylindrical water-cooled outer metal mold, a cylindrical water-cooled inner metal mold arranged therein, and an annular casting mold is formed between the water-cooled inner and outer metal molds The top of the water-cooled outer metal mold and the water-cooled inner metal mold is provided with a riser mold; the water-cooled bottom box is arranged at the lower part of the water-cooled outer metal mold and the water-cooled inner metal mold, and the molten metal passes through the water-cooled bottom box from the gate into the cavity; wherein, the gate is a tangential gate, and the molten metal enters the water-cooled bottom box tangentially from the gate, and is driven by the exit speed of the tangential gate to make the molten steel flow from the The bottom of the mold cavity rises in a circular rotation manner to obtain a pure casting surface; the longitudinal section shape of the water-cooled outer metal mold and the water-cooled inner metal mold is a metal mold with a thin top and a thick bottom with a taper. The relative solidification time of the molten metal is delayed, so that the molten metal is cooled sequentially. the

The hollow billet water-cooled casting device as described above, wherein the water-cooled outer metal mold is provided with multiple sets of water-cooled coils, and the water-cooled coils are arranged at a height of 2/3 from the bottom end of the water-cooled outer metal mold Within the range, the water inlet pipe and the water outlet pipe respectively extend to the outside of the water-cooled outer metal type. the

The water-cooled casting device for the hollow shell as described above, wherein, the water-cooled coil is arranged 30-80 mm close to the inner surface of the water-cooled outer metal mold. the

The hollow billet water-cooled casting device described above, wherein, within 2/3 of the height of the water-cooled outer metal mold, 2 to 5 sets of the water-cooled coils are arranged. the

The water-cooled casting device for the hollow billet as described above, wherein the outer surface of the water-cooled outer metal mold is provided with a refractory and heat-insulating layer within 1/3 of the height from the top down. the

The hollow billet water-cooled casting device described above, wherein, the water-cooled outer metal mold and the water-cooled inner metal mold are segmented combined metal molds, which are composed of 2 to 3 sections along the height direction, and the adjacent two metal sections The types are naturally placed and connected through the positioning of the male and female spigots. the

The hollow billet water-cooled casting device as described above, wherein, each section of the water-cooled outer metal mold is provided with at least one set of the water-cooled coils. the

The hollow billet water-cooled casting device as described above, wherein a central cooling water pipe extends through the riser mold into the bottom of the water-cooled inner metal mold, and the central cooling water pipe is fixed on the riser on the mold. the

The hollow shell water-cooled casting device as described above, wherein, the central cooling water pipe is arranged on the center line of the water-cooled inner metal mold; and is arranged on the central cooling water pipe in the water-cooled inner metal mold, along the There are multiple layers of aerosol nozzles evenly distributed in the height direction, and 4 to 8 nozzles are evenly distributed in the circumferential direction of each layer, which can open the nozzles of each layer sequentially from bottom to top, so as to realize the inner metal mold from bottom to top. Cool sequentially. the

The water-cooled casting device for the hollow shell as described above, wherein, the bottom of the central cooling water pipe is provided with a water outlet.

The hollow billet water-cooled casting device as described above, wherein the hollow billet water-cooled casting device further includes a liquid level detection device, the liquid level detection device includes a liquid level gauge and a liquid level gauge float, and the liquid level The gauge float is arranged in the water-cooled inner metal mold and connected with the liquid level gauge through a steel wire rope. the

The hollow billet water-cooled casting device as described above, wherein, the water-cooled inner metal mold is a variable-diameter metal mold, and the water-cooled inner metal mold is composed of 2 to 3 sections in the height direction. The space is naturally placed and connected through the positioning of the male and female spigots. the

The hollow billet water-cooled casting device as described above, wherein each section of the water-cooled inner metal mold has a plurality of inner metal mold units separated in the radial direction, and the upper and lower ends of each inner metal mold unit are connected to the upper and lower ends respectively. The flange is connected with the lower flange to form a complete water-cooled inner metal mold, and each inner metal mold unit can move radially relative to the upper and lower flanges. the

The hollow billet water-cooled casting device described above, wherein the water-cooled inner metal mold in each section is composed of an upper flange, a lower flange, and 4 to 8 inner metal mold units, and every two adjacent inner metal molds There is a gap between the units; the upper flange and the lower flange are radially provided with long bolt holes connecting the inner metal type units, and each inner metal type unit is arranged on the The bolts in the long bolt holes are respectively connected to the upper flange and the lower flange. When squeezed by the shrinkage of the casting, the bolts connecting the flanges can slide along the long bolt holes, and the gap between adjacent inner metal molded units It is reduced by compression to achieve diameter reduction to prevent shrinkage cracks of castings and prevent locking of castings and inner metal molds. the

The hollow shell blank water-cooled casting device as described above, wherein, the gap between two adjacent inner metal mold units is filled with filler, and the filler is a shrinkable refractory material, so as to prevent the casting Drill steel in the gap. the

The hollow shell blank water-cooled casting device as described above, wherein, the joints of the inner walls of the water-cooled inner metal molds are provided with a baffle with a width greater than the width of the gap, and each of the baffles is connected to two adjacent inner molds. The metal mold units are connected and can slide along with the contraction of the metal mold body. the

The hollow billet water-cooled casting device as described above, wherein, the inner surface of the water-cooled outer metal mold and the outer surface of the water-cooled inner metal mold are provided with a high-temperature refractory coating; the high-temperature refractory coating is thick at the top and thin at the bottom The wedge-shaped variable thickness coating forms the mold cavity coated with the coating layer into a substantially cylindrical shape. the

The water-cooled casting device for the hollow shell as described above, wherein the high-temperature refractory coating has a thickness ranging from 0.1 to 20 mm, and is composed of a coating layer and a sand layer. the

The hollow shell water-cooled casting device as described above, wherein the high-temperature refractory coating includes a chrome ore sand layer coated on the inner wall surface of the water-cooled outer metal mold and the outer wall surface of the water-cooled inner metal mold, and coated on the A layer of zircon powder paint on a layer of chrome sand. the

The hollow billet water-cooled casting device as described above, wherein the water-cooled bottom box includes: an outer box body, an inner water-cooled annular sleeve arranged in the outer box body, and a connection between the outer box body and the inner water-cooled annular sleeve A U-shaped cavity communicated with the cavity is formed between them; the lower end of the outer box and the inner water-cooled annular sleeve is fixedly connected with the bottom box plate, and the upper end of the outer box is provided with the water-cooled outer metal The positioning spigot where the lower end of the type is connected; the outer box includes a cylindrical body and a scoop handle formed along the tangential direction of the cylindrical outer box to form a scoop-shaped water-cooled bottom box. the

The hollow billet water-cooled casting device described above, wherein, the outer box body of the water-cooled bottom box is made of cast steel or cast iron with a wall thickness of 30-100 mm. the

The hollow tube billet water-cooled casting device as described above, wherein, the inner water-cooled ring sleeve is composed of a cylindrical upper ring sleeve with a smaller diameter and a cylindrical lower ring sleeve with a larger diameter, forming a convex cylinder; The water-cooled annular sleeve is provided with a cylindrical through-hole. The outer surface is an L-shaped rotary surface composed of the outer cylindrical surface of the upper ring sleeve with a small diameter and the upper annular surface of the lower ring sleeve with a large diameter. An annular cooling iron sleeve is set on the The lower ring is placed on the circular surface, the inner peripheral surface of the annular cold iron and the L-shaped turning surface form the U-shaped cavity, and the vertical surface and the bottom surface of the U-shaped cavity are built Lined with refractory bricks. the

The hollow billet water-cooled casting device as described above, wherein a cooling water coil is embedded in the inner water-cooling annular sleeve at a distance of 30-50 mm from the L-shaped rotating surface, and the water inlet and outlet of the cooling water coil are both Lead out from the inner surface of the through inner hole, extend to the outside of the water-cooled bottom box through the central through hole of the bottom box plate. the

The hollow tube billet water-cooled casting device as described above, wherein a refractory brick tube is arranged inside the scoop handle, the refractory brick tube has a runner, and one end of the runner extends horizontally to the U-shaped cavity body, and constitute the tangential runner, and the other end of the runner passes through a 90° corner brick to form a sprue vertically upward. the

The hollow tube billet water-cooled casting device as described above, wherein a refractory brick tube is arranged inside the handle, and the refractory brick tube has a runner, and one end of the runner extends horizontally through the outer ring The cold iron and the annular refractory brick lining communicate with the U-shaped cavity and constitute the tangential runner, and the other end of the runner passes through the 90° corner brick to form a sprue vertically upward. the

The hollow billet water-cooled casting device as described above, wherein, the riser mold includes: a riser box, a hollow annular sand core arranged in it; the inner wall of the riser box is provided with a thermal insulation refractory layer, so The inner wall of the hollow annular sand core is provided with a heat-insulating fire-resistant cotton layer, and the inner cavity of the hollow annular sand core communicates with the inner cavity of the water-cooled inner metal mold. the

Compared with the known technology, the hollow billet water-cooled casting device of the present invention has the following characteristics and advantages:

1. Since the longitudinal sections of the cylindrical water-cooled outer metal mold and the cylindrical water-cooled inner metal mold of the utility model are metal molds with a thin top and a thick bottom with a taper, the metal mold has a large heat storage at the bottom and a small heat storage at the top. The heat causes the metal mold to rise rapidly to a higher temperature after being heated by the molten metal, and then the cooling intensity decreases rapidly, thereby delaying the solidification and achieving the purpose of sequential solidification. the

2. Since the water-cooled outer metal mold is independently equipped with multiple sets of cooling water coils along the height direction, it is possible to force and sequentially cool the metal mold, and the application of forced cooling relatively increases the sequential cooling capacity from bottom to top. the

3. Since the inner and outer surfaces of the water-cooled outer metal mold are surrounded by fire-resistant and heat-insulating cotton insulation layers within 1/3 of the height below the top of the water-cooled outer metal mold, this greatly reduces the heat transfer loss of the upper metal mold, greatly prolongs and delays the upper solidification time, and provides Sequential solidification creates even more powerful conditions. the

4. The water-cooled outer metal type and the water-cooled inner metal adopt a segmented combination structure to reduce the difficulty of mold manufacturing, make the height of the mold adjustable, and change height specifications more flexibly. the

5. By setting the central cooling water pipe with cooling water nozzles in the water-cooled inner metal cavity, it is possible to force the water-cooled inner metal mold to cool; the water-cooled nozzles are opened sequentially from bottom to top to realize the sequential cooling of the water-cooled inner metal mold. the

6. The water-cooled inner metal mold is made into a U-shaped structure with a closed bottom. After the casting forms a blank shell, water is directly passed into the inner cavity. It is simpler to realize the bottom-up sequential cooling method by controlling the water level. the

7. Since the water-cooled inner metal mold has a variable diameter structure, it completely solves the problems of cracks that may be caused by the blockage of solidification and shrinkage of castings, and the core is locked and cannot be opened out of the box. the

8. The upper thick and lower thin coating layers in the metal casting cavity can adjust the heat transfer capacity of the upper and lower metal liquids to the metal mold, delay the solidification time of the upper metal liquid, and strengthen the sequential solidification of the upper and lower parts. the

9. The use of an annular water-cooled bottom box with a tangential gate allows the molten metal to rotate into the cavity, making the molten metal more evenly distributed in the circumferential direction, which can greatly reduce the occurrence of surface defects such as slag inclusions and pores on the surface of the casting. It is beneficial to improve the surface quality of castings. the

10. By setting the refractory brick lining in the U-shaped cavity of the water-cooled bottom box, the anti-scouring ability of the casting mold is greatly improved. The use of water-cooled annular sleeves in the bottom box and outer ring-shaped chillers can greatly improve the stability of the bottom box during solidification. Cooling capacity, to avoid the possibility of looseness and shrinkage cavity in the water-cooled bottom box, improve the yield of the bottom of the casting, and reduce unnecessary cutting loss. the

11. In the riser casting mold composed of riser box and hollow annular sand core, the use of heat-insulating refractory cotton layer greatly reduces the heat loss of the riser, improves the feeding capacity of the riser, reduces the loss of the head of the riser, and improves the casting Yield. the

The hollow billet water-cooled casting device proposed by the utility model can realize the water-cooled casting of super large hollow billets, and can obtain high-quality tubular castings with super large specifications and large height-thickness ratios through sequential cooling and sequential solidification casting methods, which can effectively Avoid the occurrence of shrinkage cavity and porosity defects inside large, high-thickness ratio cylindrical castings, and improve the yield. the

Description of drawings

The accompanying drawings are intended to illustrate and explain the utility model schematically, and do not limit the scope of the utility model. in,

Fig. 1 is a structural schematic diagram of an embodiment of a hollow billet water-cooled casting device of the present invention;

Figure 2 is a schematic structural view of another embodiment of the hollow billet water-cooled casting device of the present invention, wherein the liquid level detection device is schematically shown;

Fig. 3A is a schematic diagram of the three-dimensional structure of the variable-diameter water-cooled inner metal mold of the hollow billet water-cooled casting device of the present invention;

Figure 3B shows the structural positions of the upper flange, lower flange and baffle of the variable-diameter water-cooled inner metal type;

Fig. 3 C is the structural representation of a group of arc-shaped inner metal mold units constituting a water-cooled inner metal mold;

Figure 4A is a schematic front view of the water-cooled inner metal mold of the hollow billet water-cooled casting device of the present invention;

Fig. 4B is the schematic left view of Fig. 4A;

Figure 4C is a schematic view of the right side of Figure 4A;

Figure 5 is a schematic cross-sectional view of the water-cooled bottom box of the hollow billet water-cooled casting device of the present invention;

Figure 6 is a schematic view of the water-cooled bottom box of the hollow billet water-cooled casting device of the present invention;

Figure 7 is a schematic diagram (1) of sequential cooling of castings produced by the hollow billet water-cooled casting device of the present invention, wherein: a, the initial stage of cooling; b, the middle stage of cooling; c, the late stage of cooling;

Figure 8 is a schematic diagram (2) of sequential cooling of castings produced by the hollow billet water-cooled casting device of the present invention, showing the position of the liquid level detection device during the cooling process, wherein: a, the initial stage of cooling; b, the middle stage of cooling; c , cooling later stage;

Fig. 9 is the CAE simulation result display diagram of the solid phase fraction change in the casting solidification process using the known static sand core casting method;

Fig. 10 is the CAE simulation result display diagram of the solid phase fraction change in the casting solidification process using the known air-cooled steel sleeve core casting method;

Fig. 11 is the CAE simulation result display diagram of the solid phase fraction change in the solidification process of the casting produced by the water-cooled casting device of the present invention;

Figure 12 is a comparison chart of the defect prediction results of casting CAE simulation using different casting methods, in which a1 and a2 are casting defect prediction using the known static sand core casting method, b1 and b2 are using the known air-cooled steel sleeve core casting method The casting defect prediction of c is the casting defect prediction produced by the water-cooled casting device of the utility model. the

Attachment number:

1. Riser mold 101. Riser box 2. Hollow annular sand core 3. Water-cooled outer metal mold

31. Water-cooled coil 4. Water-cooled inner metal type 401, upper flange 402, baffle

403. Lower flange 404. Long bolt hole 405. Bolt 406. Inner metal unit

407, threaded hole 408, stop 409, shrinkage joint 410, refractory filler

411. Inner cavity body 412. Partition plate 5. Water-cooled bottom box 500. Gate

501. Outer box body 502. Inner water-cooled ring sleeve 5021. Upper ring sleeve 5022. Lower ring sleeve

5023, through inner hole 5024, cooling water coil 503, outer ring chiller 504, bottom box plate

505. Annular refractory brick lining 506. Runner 507. Sprue 508. Scoop handle part

509. Sand lining 510. U-shaped cavity 6. Sprue 7. Casting pipe

8. Central cooling water pipe 80. Nozzle 81. Water outlet 9. Castings

10. Refractory insulation layer 11. Sprue cup 12. Thermal insulation agent 13. Liquid level gauge float

14. Liquid level gauge 15. Wire rope 16. Pulley S. Clearance

Detailed ways

In order to have a clearer understanding of the technical features, purpose and effects of the present utility model, the specific implementation, structure, features and effects of the hollow billet water-cooled casting device of the present utility model will be described in detail below in conjunction with the accompanying drawings and preferred embodiments As clear as later. In addition, through the description of specific implementation methods, the technical means and functions adopted by the utility model to achieve the intended purpose can be understood more deeply and specifically. However, the attached drawings are for reference and illustration, and are not used to explain the utility model. be restricted. the

As shown in Figure 1, a hollow billet water-cooled casting device of the present invention includes: a cylindrical water-cooled outer metal mold 3, a cylindrical water-cooled inner metal mold 4 arranged therein, and the water-cooled inner and outer metal molds Between 4 and 3, an annular casting cavity is formed; the top of the water-cooled outer metal mold 3 and the water-cooled inner metal mold 4 is provided with a riser mold 1; the water-cooled bottom box 5 is arranged on the water-cooled outer metal mold 3 and the water-cooled In the lower part of the inner metal mold 4, molten metal enters the mold cavity from the gate 500 through the water-cooled bottom box 5. Wherein, the gate 500 is a tangential horizontal gate, and the molten metal enters the water-cooled bottom box 5 from the gate 500 along a tangential direction. The lower part rises in a circular rotation to obtain a clean casting surface. The longitudinal section shape of the water-cooled outer metal mold 3 and the water-cooled inner metal mold 4 is a metal mold with a thin top and a thick bottom with a taper. The solidification time of the molten metal at the upper part of the cavity can be delayed compared with that at the lower part, so that the molten metal can be sequentially cool down. The casting is, for example, a hollow shell. the

Further, multiple sets of water-cooling coils 31 are arranged inside the water-cooling outer metal mold 3, and the water-cooling coils 31 are arranged within the height range of 2/3 upwards from the bottom end of the water-cooling outer metal mold 3, and the water inlet pipe , and the water outlet pipe extend to the outside of the water-cooled outer metal mold 3 respectively. the

For ease of design and processing, the height of each group of water-cooling coils 31 can be set to be equal. Of course, the height of each group of water-cooling coils 31 can be unequal, and the height of each group of water-cooling coils 31 can be set according to actual needs. the

A preferred scheme is that the water-cooling coil 31 is arranged 30-80 mm close to the inner surface of the water-cooling outer metal mold 3 . the

The thickness of the water-cooled outer metal mold and the water-cooled inner metal of the utility model is thin at the top and thick at the bottom, with a large heat storage at the bottom and a small heat storage at the top, so that the metal mold is heated by the metal liquid and the temperature rises rapidly to a higher temperature. The cooling intensity decreases rapidly, so as to delay the solidification and achieve the purpose of sequential solidification. On the one hand, the thicker metal mold at the lower part can maintain a large heat storage and cooling intensity, and at the same time create conditions for the buried cooling water pipe at the lower part. the

In addition, within 2/3 of the height range of the water-cooled outer metal mold 3, 2 to 5 sets of the water-cooled coils 31 are provided. the

A feasible technical solution is that the outer surface of the water-cooled outer metal mold 3 is provided with a fire-resistant and heat-insulating layer 10 within 1/3 of the height from the top downward, and the heat-insulating layer is made of heat-insulating cotton material, so that It greatly reduces the heat transfer heat loss of the upper part of the water-cooled outer metal mold 3, greatly prolongs and delays the upper solidification time, and is more conducive to the sequential solidification of the molten metal in the cavity from bottom to top. the

Another feasible technical solution is that the water-cooled outer metal mold 3 and the water-cooled inner metal mold 4 are segmented and combined metal molds, which are composed of 2 to 3 sections respectively, and male and female joints are provided between each metal mold. Positioning naturally falls into the connection. The use of metal with segmented composite structure reduces the difficulty of mold manufacturing, and the height of the mold can be adjusted according to the length requirements of the casting 9, making it more flexible to change the height specification of the mold. the

When a multi-section combined metal mold is used, at least one set of water-cooled coils 31 is provided in each water-cooled outer metal mold 3 . In a specific embodiment shown in FIG. 1 , a group of water-cooling coils 31 are arranged in each water-cooling outer metal mold 3 . the

Further, a cooling device is also provided in the water-cooled inner metal mold, specifically, a central cooling water pipe 8 passes through the riser mold 1 and extends into the bottom of the water-cooled inner metal mold 4, and the central cooling water pipe 8 is fixed on the riser mold 1. the

In a preferred technical solution, the central cooling water pipe 8 is arranged on the center line of the water-cooled inner metal type 4; and arranged on the central cooling water pipe 8 in the water-cooled inner metal type 4, along the There are multiple layers of air mist nozzles 80 evenly distributed in the direction, and 4 to 8 nozzles 80 are evenly distributed in the circumferential direction of each layer, and the nozzles 80 of each layer can be opened sequentially from bottom to top, so as to realize the inner metal mold from bottom to top. Cool in the order above. After the casting is completed, the water inlet and outlet of each group of water-cooling coils 31 and the nozzles 80 of each layer are opened sequentially from bottom to top, and the casting in the mold cavity is cooled both externally and internally from bottom to top. The cooling water ejected from the nozzle 80 is heated by the water-cooled inner metal mold 4 and evaporated, thereby cooling the lower water-cooled inner metal mold 4 and cooling the casting below. As the molten metal solidifies from bottom to top and moves upward, the nozzles 80 and the corresponding water cooling coils 31 are opened layer by layer until the metal solidifies to the lower edge of the riser, the central cooling water pipe is closed, and the remaining water in the cavity continues to evaporate to Evaporate completely. As shown in Figure 2, in another specific embodiment, the water outlet of the central cooling water pipe 8 is at the bottom of the water pipe. The water outlet 81 of the cooling water pipe 8, the cooling water is injected into the lower part of the inner cavity 411 of the water-cooled inner metal type 4 to a certain height, and the cooling water heated by the water-cooled inner metal type 4 is heated up and evaporated, thereby playing a role in cooling the lower part of the water-cooled inner body. The cooling of the metal mold 4 and the cooling of the castings below, as the molten metal solidifies from bottom to top and moves upward, the internal cooling water level is controlled by the liquid level detection device to rise continuously and is connected with the water cooling coil 31 that injects cooling water until the metal solidifies to the lower edge of the riser, the central cooling water pipe is closed, and the remaining water in the cavity continues to evaporate until it is completely evaporated to dryness. The inner cavity 411 is composed of the inner wall surface of the water-cooled inner metal mold 4 and the partition plate 412 arranged on the bottom thereof and the upper part of the through inner hole 5023 of the water-cooled bottom box 5 . the

Wherein, the liquid level detection device includes a liquid level gauge 14 and a liquid level gauge float 13, and the liquid level gauge float 13 is arranged in the water-cooled inner metal mold 4 and is connected with the liquid level gauge 14 through a steel wire rope 15 . the

As shown in Figure 2, in a specific embodiment, a first pulley 17 is provided on the top of the central cooling water pipe 8, a second pulley 16 is provided outside the metal mold, and a steel wire rope 15 is wound around the first pulley. One, the second pulley 17,16. The liquid level gauge float 13 is sleeved on the central cooling water pipe 8 , and the liquid level gauge float 13 is connected to the liquid level gauge 14 through a steel wire rope 15 . The liquid level gauge float 13 rises and falls along with the cooling water level in the water-cooled inner metal mold 4, and drives the liquid level gauge 14 to rise and fall together to indicate the height of the cooling water level in the water-cooled inner metal mold 4 at any time. the

Please refer to Fig. 1, Fig. 3A, Fig. 3B, Fig. 3C, Fig. 4A, Fig. 4B, and Fig. 4C. The variable-diameter water-cooled inner metal mold 4 is composed of 2 to 3 sections in the height direction, and each metal mold section is provided with a male and a female seam for positioning and natural connection. the

In a specific embodiment, each section of the water-cooled inner metal type 4 has a plurality of inner metal type units 406 separated in the radial direction, and the upper and lower ends of each inner metal type unit 406 are connected to the upper flange 401 and the upper flange 401 respectively. The lower flanges 403 are connected to form a complete water-cooled inner mold 4 , and each inner mold unit 406 can move radially relative to the upper and lower flanges 401 , 403 . Among them, the adjacent upper and lower flanges respectively form male and female spigots for positioning, and each water-saving inner metal mold is connected by natural drop. The cylindrical water-cooled inner metal mold 4 of the utility model can change in diameter as the molten metal solidifies and shrinks. When the casting 9 solidifies and shrinks, the inner metal mold 4 with a variable diameter will not crack the casting, and the casting 9 solidifies and shrinks. In the later stage, the water-cooled inner metal type 4 will not be locked, and the casting 9 is easy to get out of the box. the

Specifically, the water-cooled inner metal type 4 in each section is composed of an upper flange 401, a lower flange 403, and 4 to 8 1/4 to 1/8 inner metal type units 406, as shown in Figure 3 and Figure 4 As shown, in this specific embodiment, the water-cooled inner metal type 4 is divided into 4 equal parts, and is composed of four 1/4 arc-shaped inner metal type units 406. Of course, the water-cooled inner metal type 6 can also be divided into equal parts. Or 8 equal divisions, the number of equal divisions is not limited and can be determined according to the diameter of the metal type. There is a gap S between every two adjacent inner metal type units 406 , and there are contraction joints 409 between the top and bottom of each inner metal type unit 406 and the upper and lower flanges 401 , 403 . Each inner metal type unit 406 is respectively connected to the upper flange 401 and the lower flange 403 through bolts 405, and the upper flange 401 and the lower flange 403 are provided with radially arranged connecting parts along the radial direction. The long bolt holes 404 of the inner metal type unit 406, each of the inner metal type units is respectively connected with the upper flange and the lower flange through the bolts arranged in the long bolt holes, when subjected to the contraction of the casting 9 The bolts 405 connecting the flanges can slide radially outward in the long bolt holes 404 during extrusion, the gap S between adjacent inner metal mold units 406 is compressed and reduced, and the inner diameter of the water-cooled inner metal mold 4 becomes smaller. That is, the variable diameter of the water-cooled inner metal mold is realized, which can effectively prevent the casting from shrinkage cracks and prevent the casting 9 from locking with the inner metal mold. For example, in a specific embodiment, when the diameter of the inner hole of the slab is Φ800mm, the gap S can be set at 8-10mm, and there are 6 gaps S on the circumference. The size of the gap S and the number of the inner metal mold units 406 are not specifically limited, and are determined according to the size of the casting to be cast. The size of the contraction joint 409 matches the size of the gap S provided. the

Further, the gap S between two adjacent inner metal mold units 406 is filled with filler 410, which is a shrinkable refractory material, so as to prevent steel drilling into the gap S at the initial stage of casting. the

Wherein, the shrinkable refractory material may be composed of refractory fiber cotton+refractory clay+graphite. the

In addition, a baffle plate 402 with a width greater than the width of the gap S is provided at the joints of the inner walls of the two adjacent inner metal mold units 406 constituting the water-cooled inner metal mold 4, and each of the baffle plates 402 is connected to the corresponding Two adjacent inner metal-type units 406 are connected and can slide with the contraction of the inner metal-type units 406 . For example, a transverse slotted hole can be set on the baffle plate 402, and bolts pass through the slotted hole to connect the baffle plate 402 with the metal mold body. The inner diameter of type 4 becomes larger, that is, when the metal type body slides radially outward, the bolts connecting the baffle plate and the metal type body slide in the horizontal slotted hole, so that the baffle plate 402 can be moved together with the metal type body. slide. A specific technical solution is that the inner surface of the water-cooled outer metal mold 3 and the outer surface of the water-cooled inner metal mold 4 are provided with a high-temperature refractory coating, which is composed of a paint layer and a sand layer; The high-temperature refractory coating is a wedge-shaped variable-thickness coating that is thick on the top and thin on the bottom, so that the mold cavity coated with the high-temperature refractory coating is formed into a roughly cylindrical body. the

Further, the thickness of the high-temperature refractory coating ranges from 0.1 to 20 mm. In a specific embodiment, the high-temperature refractory coating includes coating on the inner wall surface of the water-cooled outer metal mold and the outer surface of the water-cooled inner metal mold. A chrome ore sand layer on the wall, and a zircon powder paint layer coated on the chrome ore sand layer. the

As shown in Figure 5 and Figure 6, the water-cooled bottom box 5 of the hollow billet water-cooled casting device of the present invention includes: an outer box body 501, an inner water-cooled annular sleeve 502 arranged in the outer box body 501, and the outer box body 501 A U-shaped cavity 510 is formed between the box body 501 and the inner water-cooled annular sleeve 502, and the U-shaped cavity 510 is located in the annular casting cavity formed between the water-cooled outer metal mold 3 and the water-cooled inner metal mold 4 the lower part and communicate with it. The lower end of the outer box body 501 and the inner water-cooled annular sleeve 502 is fixedly connected with the bottom box plate 504 , and the upper end surface of the outer box body 501 is provided with a positioning notch connected with the lower end of the water-cooled outer metal mold 3 . The outer box 501 includes a cylindrical body and a handle portion 508 formed along the tangential direction of the cylindrical outer box, forming a handle-shaped water-cooled bottom box. the

Wherein, the outer box body 501 of the water-cooled bottom box 5 is made of cast steel or cast iron with a wall thickness of 30-100mm. the

In a specific embodiment, the inner water-cooling ring sleeve 502 is composed of a cylindrical upper ring sleeve 5021 with a smaller diameter and a cylindrical lower ring sleeve 5022 with a larger diameter, forming a convex cylinder. The inner water-cooled ring sleeve 502 is provided with a cylindrical through hole 5023, and the outer surface is composed of an outer cylindrical surface of the upper ring sleeve 5021 with a small diameter and an upper circular surface of the lower ring sleeve 5022 with a large diameter to form an L-shaped surface of revolution. An outer annular cold iron 503 is set on the upper annular surface of the lower ring sleeve 5022. The inner peripheral surface of the outer annular cold iron 503 and the L-shaped turning surface form the U-shaped cavity 510. The vertical surface and the bottom surface of the U-shaped cavity 510 are built with an annular refractory brick lining 505 . the

Further, a cooling water coil 5024 is embedded in the inner water-cooling annular sleeve 502 at a distance of 30 to 50 mm from the L-shaped rotating surface, and the water inlet and outlet of the cooling water coil 5024 are connected by the through inner hole 5023 The inner surface of the bottom box plate 504 extends to the outside of the water-cooled bottom box 5 through the through hole in the center of the bottom box plate 504 . the

A specific solution is that a refractory brick tube is arranged inside the scoop handle part 508, and the refractory brick tube has a runner 506, and one end of the runner 506 extends horizontally to the U-shaped cavity 510, and The tangential runner 500 is formed, and the other end of the runner 506 forms a sprue 507 vertically upward through a 90° corner brick. the

And between the outer box body 501 and the outer peripheral surface of the outer annular cold iron 503 and the lower ring sleeve 5022 , as well as the inside of the scoop handle 508 are filled with thermal insulation lining sand 509 . the

As shown in Figure 5, in a specific embodiment, one end of the runner 506 extends horizontally, runs through the outer annular chiller 503, and the annular refractory brick lining 505 communicates with the U-shaped cavity 510. The inner wall of the annular cold iron 503 forms a tangential horizontal gate 500 , and the tangential horizontal gate 500 runs through the annular refractory brick lining 505 . the

The riser casting mold 1 of the present utility model comprises: a riser box 101, a hollow annular sand core 2 arranged therein; The inner wall of 2 is provided with a heat-insulating fire-resistant cotton layer, and the inner cavity of the hollow annular sand core 2 communicates with the inner cavity body 411 of the water-cooled inner metal mold 4 . the

Utilize the above-mentioned hollow billet water-cooled casting device of the utility model, carry out operation according to the steps of mold assembly, casting, control, unboxing. Specifically include:

Mold preparation: including the shape of the annular water-cooled bottom box, the cleaning of the water-cooled inner and outer metal molds, the outer box of the riser, the shape of the riser sand core; drying, etc. The following is a description of the hanging sand molding of the water-cooled inner metal type:

Firstly, place the lower flange 403 of the water-cooled inner metal type 4 flat on the workbench, then place each 1/4 equally divided inner metal type unit 406 at the position corresponding to the lower flange 403, and place the The T-shaped long bolt hole 404 on the flange 403 is aligned with the threaded hole of the inner metal mold unit 406, put on the fastening bolt 405 and the gasket, and adjust the required initial water-cooled inner metal mold diameter (to ensure that it is concentric with the lower flange 403 ), after installing the upper flange 401, pre-tighten the bolts of the upper and lower flanges 401 and 403, and the force should be moderate (too large force will affect the shrinkage of the casting 9, and the structure shape cannot be guaranteed if it is too small), and then, install the expansion joint The baffle plate 402 is filled with shrinkable refractory filler 410 into the expansion joint (gap S), and the outer surface of the water-cooled inner metal type 4 cylinder is coated with a thick and thin variable-thickness high-temperature refractory coating as required, including The parts of the expansion joints should be dried and corrected after completion, and then closed before pouring. the

Mold assembly:

First, place the prepared annular water-cooled bottom box 5 on the casting site, pave the ground firmly, and lead the water-cooled pipes into and out of the water pipes; sand core; smooth the joints with alcohol-based paint, ignite and dry; put the upper and lower joints of the water-cooled outer metal mold 3 together, smooth the joints with alcohol-based paint, ignite and self-dry and hoist as a whole (upper and lower joints must not be misaligned again), the centered water-cooled inner metal mold 4 is slowly assembled to the outer box mouth of the water-cooled bottom box 5; the riser mold 1 is closed; the straight casting pipe 7 and the sprue cup 11 are installed; Suck off sand impurities in the mold cavity; install the central cooling water pipe 8 in the water-cooled inner metal mold 4; connect the central cooling water pipe 8, the water inlet and outlet of the water-cooling coil 31 with the cooling water system. the

Casting, controlled cooling and unpacking of castings:

First, check whether the pipeline is connected properly, open the return water pipeline connected to the water cooling coil 31, the central cooling water pipe 8, and the cooling water coil 5024, and keep the return water pipeline unblocked;

The molten metal enters the sprue 507, the runner 506, and the tangent runner 500 arranged along the tangent of the water-cooled bottom box 5 from the casting pipe 7 connected with the sprue 507 into the U-shaped cavity 510, Driven by the speed of the tangent outlet, the molten steel rises in the cavity in a circular rotation manner, filling the cavity composed of metal molds with a thin top and a thick bottom;

Open the water inlet valve controlling the cooling water coil 5024 of the water-cooled bottom box 5, and implement forced cooling to the molten metal in the water-cooled bottom box 5; 31 water inlet valve, and simultaneously open the valve controlling the central cooling water pipe 8 arranged in the water-cooled inner metal mold 4 to cool the castings in the cavity both externally and internally;

The molten metal starts to cool and solidify from the water-cooled bottom box 5, and passes through the lower, middle and upper parts of the cavity formed by the water-cooled inner and outer metal molds 4 and 3 in turn until the riser is completely solidified; the cooling water inlet valve is closed, Continue to keep the return water pipeline unimpeded, and the water remaining in the pipeline continues to evaporate as the casting 9 continues to cool until it evaporates to dryness;

Remove the central cooling water pipe;

Unbox and clean the casting. the

In a specific embodiment, a pouring pipe 7 is provided on the water-cooled bottom box 5, and a sprue cup 11 is provided on the top of the pouring pipe 7, and the sprue cup 11, the runner 6 of the pouring pipe 7 and the water-cooled bottom box The sprue 507 of 5 is connected. According to the process requirements, the qualified molten metal is injected into the U-shaped cavity 510 of the water-cooled bottom box 5 along the tangent through the sprue cup 11 and the sprue 507 of the casting pipe 7, the sprue 507, and the runner 506; the molten steel rotates The water-cooled bottom box 5 enters the bottom, middle and upper parts of the cavity formed by the water-cooled inner and outer metal molds 4 and 3, enters the riser mold 1, and stops casting until it is 100 mm away from the upper edge of the riser box 101. the

Further, the liquid metal surface in the riser of the riser casting mold 1 is covered with a thermal insulation agent 12 which functions as a thermal insulation covering. In order to further improve the thermal insulation effect, a preferred technical solution is that the metal liquid surface in the riser is covered with a heating agent, and the heating agent is further covered with a thermal insulation agent 12 . the

As shown in Figure 1, in a feasible solution, when cooling, the water inlet and outlet of the first group of water-cooled coils 31 arranged at the lower part of the water-cooled outer metal mold 3 are opened from bottom to top, and at the same time, the Layers open the nozzles 80 on the cooling water pipe 8 in the cooling center, keep the cooling areas inside and outside the casting corresponding, and make the cooling areas rise step by step synchronously. the

As shown in Figure 2, in another feasible solution, when cooling, the water inlets and water outlets of each group of water-cooled coils arranged in the water-cooled outer metal mold are sequentially opened from bottom to top, and at the same time, the center is opened. Cool the water outlet 81 at the bottom of the water pipe 8, and keep the water level in the water-cooled inner metal type 4 at the same height as the first group of water-cooled coils 31 according to the detection results of the liquid level gauge 14; Turn on the water-cooling coils 31 of each group, and simultaneously keep the water level in the corresponding water-cooling inner metal mold 4 increasing synchronously. the

As shown in Fig. 7 and Fig. 8, the figures schematically show the changes in the initial stages of cooling of sequentially cooled castings when two kinds of central cooling water pipe structures are adopted. Specifically, after the casting operation is completed, the valve of the cooling water coil 5024 of the water-cooled bottom box 5 is first opened to forcibly cool the molten metal in the water-cooled bottom box 5; The valve of pipe 31, in an embodiment shown in Fig. 7, opens the nozzle 80 of the central cooling water pipe 8 in the water-cooled inner metal mold 4 layer by layer simultaneously, and keeps the cooling water height of spraying in the water-cooled inner metal mold 4 with the required The first group of water-cooled coils 31 are the same. Along with the solidification of the molten metal, gradually open the second group, the third ... water-cooling coils 31, and the nozzles 80 corresponding to each layer on the central cooling water pipe 8, to keep the cooling areas inside and outside the casting corresponding, and The cooling zones are raised synchronously step by step. the

In another embodiment shown in Fig. 8, the instrument different from Fig. 7 is that the central cooling water pipe 8 is not provided with a nozzle 80, but the bottom is provided with a water outlet 81, and the water cooling outer metal mold 3 lower part is first opened. While setting the valve of the water-cooling coil 31, open the water outlet 81 of the central cooling water pipe 8, and control the internal cooling water level to rise continuously by means of the liquid level detection device, so as to keep the water level in the water-cooling inner metal mold 4 at the same level as the corresponding first A group of water pipes are at the same height; while injecting cooling water into the second group and the third group of water-cooling coils 31, the water level in the corresponding inner metal mold should be kept rising synchronously, so as to keep the cooling areas inside and outside the casting corresponding. And make the cooling area rise synchronously step by step. the

The utility model forcibly drives the casting 9 to be rapidly cooled and solidified by the bottom box, and passes through the lower part, the middle part and the upper part of the cavity successively until the riser is completely solidified. After the casting 9 is completely solidified, close the cooling water inlet valve and continue to keep the return water pipeline unblocked. As the casting 9 continues to cool, the water remaining in the pipeline and the water-cooled inner metal mold will continue to evaporate until it evaporates to dryness. until. Finally, remove the central cooling water pipe. the

Then, enter the unpacking process: first remove the riser box 101 of the riser mold 1, the hollow annular sand core 2, then remove the water-cooled outer metal mold 3, remove the casting pipe 7, and cut off the runner 6; The metal mold 4, casting 9, and water-cooled bottom box 5 are transferred together to the unpacking and sand-shaking site, the bottom box plate 504 is removed, the runner 506 is cut off, the outer annular chiller 503 and the inner water-cooled annular sleeve 502 are removed; they are removed one by one The water-cooled inner metal mold 4; the casting 9 is cleaned and inspected, and transported to the next process to complete the entire casting process. the

The utility model adopts the bottom casting method, and the self-gate 500 enters the bottom of the annular cavity along the tangent line, and the molten metal rises in a circular rotation mode by means of the promotion of the exit speed of the tangent line, so that the bubbles and impurities formed at the front edge of the molten metal surface cannot enter the casting. 9 Surface stay, please refer to Figure 11 for cooperation, so a relatively pure casting surface quality can be obtained. The molten metal entering the annular cavity formed by the water-cooled outer metal mold 3 and the water-cooled inner metal mold 4 with a thin upper part and a thicker longitudinal section structure, as shown in Figures a, b, c, and d, represent different stages of casting cooling , in the figure, the light-colored area represents the unsolidified area A3, and the dark-colored area outside it represents the solidified layer B3. That is, Fig. 11a is the beginning of solidification, Fig. 11b is the initial stage of solidification, Fig. 11c is the middle stage of solidification, Fig. 11d is the later stage of solidification, and Fig. 11e is the end (full solidification). The change process of layer B3. The characteristic of this method is that in the later stage of solidification, the liquid core is narrow at the bottom and wide at the top, and shallow, so the feeding is smooth. When using the device of the present utility model to manufacture castings, firstly it is cooled by the surface of the mold and begins to solidify to form a solidified slab shell, and the molten metal located in the water-cooled bottom box 5 is subjected to three directions formed by the inner water-cooled annular sleeve 502 and the outer annular chiller 503 The forced cooling above solidifies first, and pushes the solidification front from bottom to top. The molten metal located under the water-cooled inner and outer metal molds 4 and 3 is cooled by the thick-walled metal mold below and the subsequent forced water cooling, which undertakes the solidification of the molten metal in the water-cooled bottom box 5 and continues to promote the development of the solidification front from bottom to top; Due to the thin wall thickness of the metal mold, that is, the low heat storage capacity of the mold, the temperature rises rapidly after being heated by the molten metal, causing the solidification stagnation at this place, and the thick and thin coating layer makes the metal The higher the heat transfer resistance of the liquid to the casting mold is, the higher the resistance is, so that the solidification time of the molten metal above the metal mold is delayed relative to that of the lower part, which constitutes the forced sequential cooling and sequential solidification caused by sequential cooling until the riser. The outer surface of the molten metal located in the riser is in contact with the thermal insulation refractory material of the riser mold 1, the inner surface is in contact with the core sand core made of thermal insulation refractory material, and the upper surface is in contact with the thermal insulation agent 12, which has excellent Therefore, the superheated state of the molten metal can be maintained for a long time until the sequential solidification is pushed to the end of the riser solidification; thus avoiding the occurrence of shrinkage cavity and loose defects inside the large, high-thickness ratio cylindrical casting, such as As shown in Figure e in Figure 11, the casting defects produced by the device of the present invention are concentrated in the middle of the riser and the wall thickness of the casting, and the defect level is relatively light, which can be easily overcome by subsequent forging operations. Casting defects. The utility model is particularly suitable for the manufacture of large thick-walled tube blanks with a thickness of 100-600 mm, a diameter of 800-2000 mm and a height of 2000-6000 mm. the

Figure 12 is a comparison chart of casting CAE simulation defect prediction results displayed using different casting methods, in which Figures 12a1 and a2 are casting defect predictions using the known static sand core casting method, as shown in the figure, darker colors represent defects F It is very serious and concentrated on the inner surface; Fig. 12b1 and b2 are casting defect predictions using the known air-cooled steel sleeve casting method. As shown in the figure, the deeper color indicates that the defect F' is serious and located inside the surface layer; Fig. 12c is the defect prediction of the casting produced by the water-cooled casting device of the present invention. As shown in the figure, the dotted line in the middle of the casting represents the defect F", and its lighter color means that the defect is light, and the defect is located in the middle of the casting wall thickness. Through the follow-up The forging process of the utility model is easy to overcome this defect. Therefore, compared with the known technology, the casting produced by the device of the present utility model has greatly reduced the casting defect and improved the yield. 

The instrument described above is an illustrative embodiment of the present utility model, and is not intended to limit the scope of the present utility model. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principle of the present utility model shall fall within the protection scope of the present utility model. And it should be noted that each component of the utility model is not limited to the above-mentioned overall application, and each technical feature described in the description of the utility model can be selected to be used alone or in combination according to actual needs, so , the utility model naturally covers other combinations and specific applications related to the invention point of the case. the

Claims (26)

1. The utility model provides a hollow shell water-cooling casting device which characterized in that, casting device includes: the cylindrical water-cooling outer metal mold is arranged in the cylindrical water-cooling inner metal mold, and an annular casting cavity is formed between the water-cooling inner metal mold and the water-cooling outer metal mold; riser casting molds are arranged at the tops of the water-cooled outer metal mold and the water-cooled inner metal mold; the water-cooling bottom box is arranged at the lower parts of the water-cooling outer metal mold and the water-cooling inner metal mold, and the molten metal enters the cavity from the pouring gate through the water-cooling bottom box; the pouring gate is a tangential side gate, molten metal enters the water-cooling bottom box from the pouring gate along the tangential direction, and the molten steel rises from the lower part of the cavity in a circumferential rotation mode by the aid of pushing of the outlet speed of the tangential side gate so as to obtain a pure casting surface; the longitudinal section shapes of the water-cooling outer metal mold and the water-cooling inner metal mold are metal molds with thin tops and thick bottoms and taper, and the relative solidification time of the molten metal above the inside of the cavity is delayed from that below, so that the molten metal is sequentially cooled.

2. The water-cooling casting device for the hollow shell as claimed in claim 1, wherein a plurality of groups of water-cooling coils are arranged in the water-cooling outer metal mold, the water-cooling coils are arranged in a height range of 2/3 from the bottom end of the water-cooling outer metal mold, and a water inlet pipe and a water outlet pipe of each water-cooling coil respectively extend to the outside of the water-cooling outer metal mold.

3. The water-cooling casting device for the hollow shell as claimed in claim 2, wherein the water-cooling coil is arranged at a position which is 30-80 mm close to the inner surface of the water-cooling outer metal mold.

4. The water-cooling casting device for the hollow shell as claimed in claim 2, wherein 2-5 groups of water-cooling coils are arranged in the 2/3 height range of the water-cooling outer metal mold.

5. The water-cooled casting apparatus for a hollow shell according to claim 1, wherein the water-cooled outer mold has a refractory heat insulating layer provided around the outer surface thereof within a height range of 1/3 degrees from the top downward.

6. The water-cooling casting device for the hollow pipe blank according to any one of claims 1 to 5, wherein the water-cooling outer metal mold and the water-cooling inner metal mold are sectional combined metal molds and respectively comprise 2-3 sections in the height direction, and two adjacent metal molds are positioned through male and female rabbets and naturally fall and connected.

7. A water-cooled casting device for hollow shell pipes as claimed in claim 6, wherein at least one set of water-cooled coil pipe is arranged in each section of the water-cooled outer metal mold.

8. The water-cooled casting apparatus for a hollow shell as claimed in claim 1, wherein a central cooling water pipe is extended through said riser mold into the bottom of said water-cooled metal mold, and said central cooling water pipe is erected on said riser mold.

9. The water-cooled casting apparatus for a hollow shell according to claim 8, wherein the central cooling water pipe is provided on a center line of the water-cooled inner metal mold; and set up in the metal type in the water-cooling on the central condenser tube, along direction of height equipartition multilayer aerial fog nozzle, 4 ~ 8 nozzles are being equipped with to the equipartition in the circumferencial direction ring on every layer, can open every layer of nozzle from bottom to top in proper order to realize the interior metal type sequential cooling from bottom to top.

10. The water-cooled casting device for the hollow shell as claimed in claim 8, wherein the bottom of the central cooling water pipe is provided with a water outlet.

11. The water-cooling casting device for the hollow pipe blank according to claim 10, further comprising a liquid level detection device, wherein the liquid level detection device comprises a liquid level meter and a liquid level meter float, and the liquid level meter float is arranged in the metal mold in the water cooling and is connected with the liquid level meter through a steel wire rope.

12. The water-cooling casting device for the hollow pipe blank according to claim 1, wherein the water-cooling inner metal mold is a variable-diameter metal mold, the water-cooling inner metal mold is composed of 2-3 sections in the height direction, and two adjacent sections of metal molds are positioned through male and female rabbets and naturally fall and connected.

13. The water-cooled casting apparatus for a hollow shell as claimed in claim 12, wherein each of said water-cooled inner metal molds has a plurality of inner metal mold units divided in a radial direction, upper and lower ends of each inner metal mold unit are connected to an upper flange and a lower flange, respectively, to form a complete water-cooled inner metal mold, and each of said inner metal mold units is movable in a radial direction with respect to said upper and lower flanges.

14. The water-cooling casting device for the hollow pipe blank according to claim 13, wherein each section of the water-cooling inner metal mold is composed of an upper flange, a lower flange and 4-8 inner metal mold units, and a gap is formed between every two adjacent inner metal mold units; go up flange and lower flange go up along the radius direction be radial connection of putting the long bolt hole of interior metal type unit, every interior metal type unit is through setting up bolt in the long bolt hole respectively with go up the flange and be connected with lower flange, the bolt of flange can slide along the long bolt hole when receiving the extrusion of foundry goods shrink, and the clearance between the adjacent interior metal type unit is pressed and is reduced, realizes the reducing to prevent foundry goods shrink crackle, prevent foundry goods and interior metal type locking.

15. The water-cooled casting apparatus for a hollow shell according to claim 14, wherein a filler is filled in a gap between two adjacent inner metal mold units, and the filler is a yieldable refractory material to prevent steel from being drilled into the gap at an early stage of casting.

16. The water-cooling casting device of the hollow pipe blank according to claim 14 or 15, wherein a baffle plate with the width larger than the width of the gap is arranged at the joint of the inner walls of the water-cooling inner metal mold, and each baffle plate is connected with two adjacent inner metal mold units and can slide along with the contraction of the metal mold body.

17. The water-cooling casting device for the hollow shell according to claim 1, characterized in that: the inner surface of the water-cooling outer metal mold and the outer surface of the water-cooling inner metal mold are both provided with high-temperature refractory material coatings; the high-temperature refractory material coating is a wedge-shaped variable-thickness coating with a thick upper part and a thin lower part, so that the cavity coated with the coating layer is formed into a roughly cylindrical body.

18. The water-cooling casting device for the hollow shell as claimed in claim 17, wherein the thickness of the high-temperature refractory coating ranges from 0.1 mm to 20mm, and the high-temperature refractory coating is composed of a coating layer and a sand layer.

19. The water-cooled casting apparatus for a hollow shell according to claim 18, wherein the high-temperature refractory coating includes a chromium ore sand layer coated on an inner wall surface of the water-cooled outer metal mold and an outer wall surface of the water-cooled inner metal mold, and a zircon powder coating layer coated on the chromium ore sand layer.

20. The water-cooled casting apparatus for a hollow shell according to claim 1, wherein the water-cooled bottom box comprises: the outer box body is an inner water-cooling annular sleeve arranged in the outer box body, and a U-shaped cavity communicated with the cavity is formed between the outer box body and the inner water-cooling annular sleeve; the lower ends of the outer box body and the inner water-cooling annular sleeve are fixedly connected with the bottom box plate, and the upper end surface of the outer box body is provided with a positioning spigot connected with the lower end of the water-cooling outer metal mold; the outer box body comprises a cylindrical body and a gourd ladle handle part formed along the tangential direction of the cylindrical outer box body to form a gourd ladle handle-shaped water-cooling bottom box.

21. A water-cooled casting apparatus for a hollow shell as claimed in claim 20, wherein the outer casing of the water-cooled bottom box is made of cast steel or cast iron having a wall thickness of 30 to 100 mm.

22. The water-cooled casting apparatus for a hollow shell as claimed in claim 20, wherein said inner water-cooled annular sleeve is formed of a cylindrical upper annular sleeve having a smaller diameter and a cylindrical lower annular sleeve having a larger diameter to form a convex cylindrical body; the inner water-cooling annular sleeve is internally provided with a cylindrical through inner hole, the outer surface of the inner water-cooling annular sleeve forms an L-shaped revolution surface by an outer cylindrical surface of the upper annular sleeve with a small diameter and an annular surface of the lower annular sleeve with a large diameter, an annular chilling block is sleeved on the annular surface of the lower annular sleeve, the inner circumferential surface of the annular chilling block and the L-shaped revolution surface form the U-shaped cavity, and the vertical surface and the bottom surface of the U-shaped cavity are built with refractory brick linings.

23. The water-cooling casting device for the hollow shell as claimed in claim 22, wherein a cooling water coil is embedded in the inner water-cooling annular sleeve at a position 30-50 mm away from the L-shaped revolution surface, and a water inlet and a water outlet of the cooling water coil are both led out from the inner surface of the through inner hole and extend to the outside of the water-cooling bottom box through the central through hole of the bottom box plate.

24. A water-cooled casting apparatus for a hollow shell as claimed in claim 20, wherein a refractory brick tube is provided in the ladle portion, the refractory brick tube has a runner, one end of the runner extends horizontally to the U-shaped cavity and forms the tangential runner, and the other end of the runner forms a sprue vertically upward through a 90 ° corner brick.

25. The water-cooled casting device for the hollow shell as claimed in claim 22, wherein a refractory brick tube is arranged in the ladle handle part, the refractory brick tube is provided with a cross gate, one end of the cross gate extends horizontally, penetrates through the outer annular chill and the annular refractory brick lining, is communicated with the U-shaped cavity and forms the tangential cross gate, and the other end of the cross gate is vertically upwards formed into a straight gate through a 90-degree corner brick.

26. A water-cooled casting apparatus for a hollow shell as claimed in claim 20, wherein said riser mold comprises: the riser box is a hollow annular sand core arranged in the riser box; the inner wall of the riser box is provided with a heat-insulating refractory material layer, the inner wall of the hollow annular sand core is provided with a heat-insulating refractory cotton layer, and the inner cavity of the hollow annular sand core is communicated with the inner cavity of the water-cooling inner metal mold.

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