Roller cold mold and casting method
By adopting stacked sand box molds and top-fill back-casting technology, the problems of short life and large molten iron consumption in traditional roll cold mold manufacturing are solved, and the effect of reducing molten iron consumption and manufacturing cost is achieved, and the mechanical properties of the castings and the stability of the casting process are improved.
Patent Information
- Application Number
- CN202411877485.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-04-11
AI Technical Summary
During the manufacturing process of traditional roll cold roll molds, the cold molds are prone to internal cavity cracks or deformation during use, resulting in shortening of service life and large consumption. At the same time, casting methods lead to large iron consumption and high manufacturing cost.
A roll cold mold consisting of several sand boxes stacked, and each sand box is equipped with a casting channel that can be topped and bottomed and a through ring cavity. Through the casting method of topped and bottomed and the layout of straight runners, horizontal runners, and inner runners, uniform filling of molten iron and reducing waste.
It effectively reduces molten iron consumption and manufacturing cost, reduces casting defects, improves the mechanical properties of castings, prevents fire running, and ensures the stability of the casting process.
Smart Images
Figure CN119794273A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of roller manufacturing, and in particular relates to a roller cold mold and a casting method. Background Art
[0002] In the field of roll manufacturing, the roll cold mold is one of the key tools, and its role is to form the final shape of the roll. In the traditional roll manufacturing process, there is only a 1-2mm coating as an isolation layer between the cold mold and the roll molten steel. However, due to the scouring of high-temperature molten steel and the effect of thermal stress, the cold mold is prone to internal cracks or deformation during use, resulting in a shortened service life of the cold mold and a large consumption.
[0003] Traditional roll cold casting usually adopts an open cavity design. In addition to the machining allowance of the casting itself, the cavity height needs to leave an additional 700-800mm as a riser to compensate for the shrinkage of molten steel during the cooling process. Although this design can ensure the integrity of the casting, it also brings about the problem of high molten iron consumption and high manufacturing cost. The large amount of molten iron consumption not only increases the material cost, but also leads to a waste of energy and resources.
[0004] Therefore, a roll cold mold and casting method that can effectively reduce molten iron consumption and manufacturing cost are now needed. Summary of the invention
[0005] The purpose of the present invention is to provide a cold roll mold and a casting method, which can effectively reduce molten iron consumption and manufacturing costs.
[0006] To achieve the above purpose, the technical solution adopted by the present invention is: A cold-type mold for a rolling mill roller comprises a plurality of sand boxes which are stacked in sequence from top to bottom and are filled with sand molds, a pouring basin which is arranged on the top sand box and is located at the center of the sand box, and a plurality of weights which are arranged on the top sand box and are evenly spaced around the pouring basin along its circumference, wherein each sand box is provided with a pouring channel which can be used for top pouring and bottom return, and each sand box located in the middle has a corresponding through annular cavity along its thickness direction, the upper end of the pouring channel is connected to the pouring basin, and the lower end thereof is connected to the annular cavity located above the bottom sand box.
[0007] A further improvement of the technical solution of the present invention is that the pouring channel includes straight runners opened at the center position of each sand box along the thickness direction thereof, a plurality of cross runners radially distributed in the bottom sand box and connected at one end to the lower end of the straight runners, and an endogate opened along the thickness direction of the bottom sand box and corresponding to each cross runner, the lower end of the endogate is connected to the other end of the cross runner, and the upper end thereof is connected to the annular cavity located above the bottom sand box.
[0008] A further improvement of the technical solution of the present invention is that the upper end of the sprue of the top sand box is connected to the bottom of the pouring basin, and the lower end thereof is connected and penetrated with the sprues of each sand box below it.
[0009] A further improvement of the technical solution of the present invention is that a plurality of positioning pins evenly spaced circumferentially are provided between two adjacent sand boxes.
[0010] A further improvement of the technical solution of the present invention is that four cross runners are radially distributed in the bottom sand box, and one end of the four cross runners is connected to the lower end of the straight runner of the bottom sand box through a reducing five-way.
[0011] The further improvement of the technical solution of the present invention is that: the sand mold adopts water glass self-hardening sand or furan resin sand; and the sand box adopts low-carbon steel.
[0012] A further improvement of the technical solution of the present invention is that the diameter of the sprue is 100-150 mm, and the diameters of the runner and the ingates are both 50-80 mm.
[0013] A method for casting a cold roll mold, using a mold to cast the cold roll mold, comprising the following steps: Step S1: stack the flasks from top to bottom in sequence and combine them, and position them by positioning pins between two adjacent flasks so that the sprues of the flasks and the annular cavities of the flasks in the middle are aligned without misalignment; Step S2: placing the pouring basin on the top sand box so that the upper end of the sprue of the top sand box is connected to the bottom of the pouring basin; Step S3: placing a plurality of iron weights on the top sand box, so that the iron weights are evenly spaced around the pouring basin in the circumferential direction, and the total weight of all the iron weights is greater than twice the amount of molten iron contained in all the annular cavities, so as to prevent fire from escaping; Step S4: Pour molten iron from the pouring basin by top pouring and bottom return. The molten iron enters the annular cavity above the sand box through the pouring channel. After pouring, 0.5-1 ton of molten iron remains in the pouring basin. The principle of communicating vessels is used to form liquid molten iron pressure, so that the molten iron in the annular cavity solidifies into a cold roll mold.
[0014] A further improvement of the technical solution of the present invention is that during the pouring process of step S4, the molten iron level in the pouring basin is ensured to be always higher than 1 / 2 of the total height of the pouring basin, and the designed pouring time is less than 2 minutes.
[0015] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is: The cold roll mold and casting method of the present invention can effectively reduce molten iron consumption and manufacturing cost.
[0016] Each sand box used in the present invention is equipped with a pouring channel that can be used for top pouring and bottom return. Each sand box located in the middle is provided with a corresponding through annular cavity along the thickness direction thereof, so that the annular cavity in the middle abuts the top and bottom sand boxes respectively, and the upper end of the pouring channel is connected with the pouring basin, and the lower end thereof is connected with the annular cavity located above the bottom sand box. During pouring, molten iron can be poured from the pouring basin, and the molten iron enters the annular cavity above the bottom sand box through the pouring channel. There is no exhaust hole and no need to design a riser, which ensures that the molten iron is evenly filled while reducing the waste of molten iron.
[0017] The top-pouring and bottom-returning pouring method adopted by the present invention combines the layout of the sprue, the runner and the inner runner, which is conducive to the smooth flow of molten iron, can ensure that the molten iron evenly fills the annular cavity, and reduces casting defects such as pores and slag inclusions.
[0018] The present invention retains a certain amount of molten iron in the pouring basin and utilizes the liquid molten iron pressure formed by the communicating vessel principle to help the molten iron in the annular cavity form a dense structure during the solidification process, thereby improving the mechanical properties of the casting.
[0019] The iron weights used in the present invention are evenly distributed circumferentially on the top sand box, and the total weight of all the iron weights is greater than twice the amount of molten iron contained in all the annular cavities, which can effectively prevent the molten iron from escaping during the pouring process and ensure the stability of the casting process. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a structural schematic diagram of the cold type mold of the rolling roll of the present invention; Among them, 1. gate basin, 2. pressure iron, 3. sand mold, 4. sprue, 5. sand box, 6. positioning pin, 7. annular cavity, 8. runner, 9. ingates. DETAILED DESCRIPTION
[0021] The present invention is further described in detail below in conjunction with embodiments: Example 1 like Figure 1 As shown, this embodiment provides a cold mold for a rolling mill roll, including a plurality of sand boxes 5, a pouring basin 1 and a plurality of weights 2. The plurality of sand boxes 5 are stacked in sequence from top to bottom, and the interior of the sand boxes 5 is filled with a sand mold 3. Preferably, the sand mold 3 is made of water glass self-hardening sand or furan resin sand, and the sand box 5 is made of low-carbon steel. The pouring basin 1 is arranged on the top sand box 5, and the pouring basin 1 is located at the center of the top sand box 5. A plurality of weights 2 are also arranged on the top sand box 5, and each weight 2 is evenly spaced around the pouring basin 1 along the circumference of the top sand box 5, which can effectively prevent the molten iron from escaping during the pouring process and ensure the stability of the casting process.
[0022] Among them, each sand box 5 is provided with a pouring channel capable of top pouring and bottom return, and each sand box 5 located in the middle has a corresponding through annular cavity 7 along its thickness direction. The so-called "each sand box 5 in the middle" refers to the other sand boxes 5 located between the top and bottom sand boxes 5, so that the annular cavity 7 between the top and bottom sand boxes 5 abuts against the top and bottom sand boxes 5, that is, the annular cavity 7 located below the top sand box 5 abuts against the bottom of the top sand box 5, and the annular cavity 7 located above the bottom sand box 5 abuts against the top of the bottom sand box 5. The annular cavity 7 of each sand box 5 in the middle can be combined to adapt to the shape of the cold mold casting of the roll. In order to realize the top-pouring and bottom-return pouring method, the upper end of the pouring channel is connected with the pouring basin 1, and the lower end of the pouring channel is connected with the annular cavity 7 located above the bottom sand box 5. During pouring, molten iron can be poured from the pouring basin 1, and the molten iron enters the annular cavity 7 above the bottom sand box 5 through the pouring channel. There is no exhaust hole and no need to design a riser, which ensures that the molten iron is evenly filled while reducing the waste of molten iron.
[0023] Furthermore, the pouring channel includes a straight runner 4 respectively arranged in each sand box 5 and a plurality of cross runners 8 arranged in the bottom sand box 5 and an ingates 9 corresponding to each cross runner 8, that is, each cross runner 8 and each ingates 9 are arranged in the bottom sand box 5, wherein the diameter of the straight runner 4 is 100-150mm, and the diameters of the cross runner and the ingates are both 50-80mm.
[0024] Specifically, each sand box 5 has a corresponding sprue 4 at its center position along its thickness direction, the upper end of the sprue 4 of the top sand box 5 is connected to the bottom of the gate basin 1, and the lower end of the sprue 4 of the top sand box 5 is connected and connected to the sprue 4 of each sand box 5 below it, thereby forming a through vertical runner. Each horizontal runner 8 is radially distributed in the bottom sand box 5, and one end of each horizontal runner 8 is connected to the lower end of the sprue 4 of the bottom sand box 5. Each ingates 9 is opened along the thickness direction of the bottom sand box 5, that is, the ingates 9 are the same as the sprue 4, and are both vertical runners. And each ingates 9 corresponds to each horizontal runner 8, the lower end of the ingates 9 is connected to the other end of the horizontal runner 8, and the upper end of the ingates 9 is connected to the annular cavity 7 located above the bottom sand box 5, that is, each ingates 9 is circumferentially distributed in the bottom sand box 5 and adapted to the annular cavity 7. Preferably, four runners 8 are radially distributed in the bottom sand box 5, and one end of each of the four runners 8 is connected to the lower end of the sprue 4 of the bottom sand box 5 through a reducing five-way. After pouring molten iron from the pouring basin 1, the molten iron can enter the bottom sand box 5 through each sprue 4 in turn, and then flow radially along each runner 8 to each ingrate 9 in the bottom sand box 5, and finally enter the annular cavity 7 above the bottom sand box 5 through each ingrate 9. The top pouring and bottom return pouring method combines the layout of the sprue, runner and ingrate, which helps the molten iron to flow smoothly, can ensure that the molten iron evenly fills the annular cavity 7, and reduces casting defects such as pores and slag inclusions.
[0025] In order to ensure that the sprues 4 of each sand box 5 and the annular cavities 7 of each sand box 5 in the middle are aligned without misalignment, a plurality of circumferentially evenly spaced positioning pins 6 are provided between two adjacent sand boxes 5. Preferably, three circumferentially evenly spaced positioning pins 6 are provided between two adjacent sand boxes 5.
[0026] Example 2 This embodiment provides a method for casting a cold roll mold. Casting a cold roll mold using the mold of Embodiment 1 includes the following steps: Step S1: stacking the flasks 5 from top to bottom in sequence, and positioning them by positioning pins 6 between two adjacent flasks 5, so that the sprues 4 of the flasks 5 and the annular cavities 7 of the intermediate flasks 5 are aligned without misalignment; Step S2: placing the pouring basin 1 on the top sand box 5 so that the upper end of the sprue 4 of the top sand box 5 is connected to the bottom of the pouring basin 1; Step S3: placing a plurality of iron weights 2 on the top sand box 5, so that the iron weights 2 are evenly spaced around the pouring basin 1 in the circumferential direction, and the total weight of all the iron weights 2 is greater than twice the amount of molten iron contained in all the annular cavities 7, so as to prevent fire from running out; Step S4: Pour molten iron from the pouring basin 1 in a top-pouring and bottom-returning manner. The molten iron enters the annular cavity 7 above the sand box 5 through the pouring channel. After the pouring is completed, 0.5-1 ton of molten iron remains in the pouring basin 1. The principle of communicating vessels is used to form liquid molten iron pressure, so that the molten iron in the annular cavity 7 solidifies into a cold roll mold. During the pouring process, ensure that the molten iron level in the pouring basin 1 is always higher than 1 / 2 of the total height of the pouring basin 1, and the designed pouring time is less than 2 minutes.
[0027] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.
Claims
1. A cold roller die, characterized in that: The invention comprises a plurality of sand boxes (5) stacked in sequence from top to bottom and filled with sand molds (3), a pouring basin (1) arranged on the top sand box (5) and located at the center of the sand box (5), and a plurality of weights (2) arranged on the top sand box (5) and evenly spaced around the pouring basin (1) along its circumference, wherein each sand box (5) is provided with a pouring channel capable of top pouring and bottom return, and each sand box (5) located in the middle is provided with a corresponding through annular cavity (7) along its thickness direction, the upper end of the pouring channel is connected to the pouring basin (1), and the lower end thereof is connected to the annular cavity (7) located above the bottom sand box (5).
2. A cold roll die according to claim 1, characterized in that: The pouring channel comprises a straight runner (4) opened at the center position of each sand box (5) along the thickness direction thereof, a plurality of cross runners (8) radially distributed in the bottom sand box (5) and connected at one end to the lower end of the straight runner (4), and an endogate (9) opened along the thickness direction of the bottom sand box (5) and corresponding to each cross runner (8), wherein the lower end of the endogate (9) is connected to the other end of the cross runner (8), and the upper end thereof is connected to the annular cavity (7) located above the bottom sand box (5).
3. A cold roll die according to claim 2, characterized in that: The upper end of the sprue (4) of the top sand box (5) is connected to the bottom of the pouring basin (1), and the lower end thereof is connected to and penetrates the sprues (4) of each sand box (5) below it.
4. A cold roll die according to claim 3, characterized in that: A plurality of positioning pins (6) evenly spaced in the circumferential direction are provided between two adjacent sand boxes (5).
5. A cold roll die according to any one of claims 2 to 4, characterized in that: Four cross runners (8) are radially distributed inside the bottom sand box (5), and one end of each of the four cross runners (8) is connected to the lower end of the sprue (4) of the bottom sand box (5) through a reducing five-way joint.
6. A cold roll die according to claim 5, characterized in that: The sand mold (3) is made of water glass self-hardening sand or furan resin sand; and the sand box (5) is made of low carbon steel.
7. A cold roll die according to claim 6, characterized in that: The diameter of the sprue (4) is 100-150 mm, and the diameters of the runner and the ingates are both 50-80 mm.
8. A method for casting a cold roll, characterized in that: The method of using the mold casting roll cold mold according to any one of claims 1 to 7 comprises the following steps: Step S1: stacking the flasks (5) from top to bottom in sequence to form a flask, and positioning the flasks (5) by positioning pins (6) between two adjacent flasks (5) so that the sprues (4) of the flasks (5) and the annular cavities (7) of the intermediate flasks (5) are aligned without misalignment; Step S2: placing the pouring basin (1) on the top sand box (5) so that the upper end of the sprue (4) of the top sand box (5) is connected to the bottom of the pouring basin (1); Step S3: placing a plurality of iron weights (2) on the top sand box (5), so that the iron weights (2) are evenly spaced around the pouring basin (1) in the circumferential direction, and the total weight of all the iron weights (2) is greater than twice the amount of molten iron contained in all the annular cavities (7) to prevent fire from escaping; Step S4: The molten iron is poured from the pouring basin (1) by the top pouring and bottom return method. The molten iron enters the annular cavity (7) above the sand box (5) through the pouring channel. After the pouring is completed, 0.5-1 ton of molten iron remains in the pouring basin (1). The liquid molten iron pressure is formed by using the communicating vessel principle, so that the molten iron in the annular cavity (7) solidifies into a cold roll mold.
9. A method for casting a cold roll mold according to claim 8, characterized in that: During the pouring process of step S4, it is ensured that the molten iron level in the pouring basin (1) is always higher than 1 / 2 of the total height of the pouring basin (1), and the designed pouring time is less than 2 minutes.