A cold crucible drip melting and rod drawing device and a rod drawing method

Abstract

The present invention relates to a cold crucible drop melting and rod drawing device and a rod drawing method. The cold crucible drop melting and rod drawing device includes a feeding cavity, a melting cavity, a rod drawing cavity, a feeding mechanism, a crucible, a conical heating part, a rod drawing mechanism and a rod drawing rod group. The feeding cavity and the rod drawing cavity are respectively installed at the upper end and the lower end of the melting cavity and are both communicated with the melting cavity. The feeding end of the feeding mechanism is located in the feeding cavity and is used for transporting the raw material ingot downward into the melting cavity. The conical heating part and the crucible are installed up and down in the melting cavity. The upper opening of the crucible corresponds to the closing end of the conical heating part and receives the molten solution of the raw material ingot heated and melted by the conical heating part. The flaring end of the conical heating part is arranged corresponding to the feeding end and performs annular conical heating on the fed raw material ingot. The upper end of the rod drawing rod group is located in the rod drawing cavity and can be adaptively inserted into the lower opening of the crucible. The moving end of the rod drawing mechanism is connected to the lower end of the rod drawing rod group and drives the rod drawing rod group to move up and down for rod drawing.

Description

Technical Field

[0001] The present invention relates to the technical field of alloy melting preparation, and particularly relates to a cold crucible drop melting rod drawing device and a rod drawing method. Background Art

[0002] At present, for the preparation of small-diameter alloy rods with a diameter of less than 100 mm, a method combining vacuum consumable melting and forging is mostly adopted. First, a large-diameter alloy ingot is made by vacuum consumable melting, and then a small-diameter alloy rod is formed by forging. However, for the preparation of rods of some difficult-to-forge materials, the forging process is very difficult. For example, for superalloys such as titanium alloys and nickel-based alloys, they are prone to softening, sintering, and oxidation at high temperatures, with poor metal fluidity. The process is complex and requires multiple forging operations, resulting in large forging losses and high forging difficulty. For materials with high brittleness, high hardness, and poor toughness, forging is likely to produce obvious defects and a low yield. At the same time, the control of temperature, forging pressure, and the preparation of dies in forging also make the forging process complex and costly. Summary of the Invention

[0003] The present invention provides a cold crucible drop melting rod drawing device and a rod drawing method to solve one or several of the technical problems existing in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A cold crucible drop melting rod drawing device includes a feeding cavity, a melting cavity, a rod drawing cavity, a feeding mechanism, a crucible, a conical heating part, a rod drawing mechanism, and a rod drawing rod group. The feeding cavity and the rod drawing cavity are respectively installed at the upper end and the lower end of the melting cavity and are both communicated with the melting cavity.

[0005] The feeding end of the feeding mechanism is located in the feeding cavity and is used to transport the raw material ingot downward into the melting cavity. The conical heating part and the crucible are installed up and down in the melting cavity. The upper opening of the crucible corresponds to the closing end of the conical heating part and receives the molten solution of the raw material ingot heated and dropped by the conical heating part. The flaring end of the conical heating part is arranged corresponding to the feeding end and performs annular conical heating on the fed raw material ingot. The upper end of the rod drawing rod group is located in the rod drawing cavity and can be adaptively inserted into the lower opening of the crucible. The moving end of the rod drawing mechanism is connected to the lower end of the rod drawing rod group and drives the rod drawing rod group to move up and down for rod drawing.

[0006] The beneficial effect of the present invention is that: In the cold crucible drop melting rod drawing device of the present invention, the raw material ingot is sent into the conical heating part by the feeding mechanism, the lower end of the raw material ingot is melted by induction heating, and the molten drops continuously drip into the crucible (optionally a water-cooled copper crucible). The lower end of the raw material ingot is melted by induction heating of the conical heating part to form molten drops, and the molten drops drip into the crucible, so that the inner diameter of the crucible can be reduced, and it is not limited by the raw material size, and small-diameter rods can be drawn.

[0007] In the present invention, the lower end of the raw material ingot can be set as a conical surface, and the conical heating part is used to inductively heat the conical surface of the raw material ingot to melt it into molten droplets, and the molten droplets drip along the conical tip and enter the crucible.

[0008] Based on the above technical solutions, the present invention can be further improved as follows.

[0009] Further, a crucible heating part is also provided in the smelting cavity. The crucible includes a heat preservation section and a solidification section that are integrally connected in sequence from top to bottom. The crucible heating part is connected to the heat preservation section and further melts and keeps warm the raw material ingot solution dripping into the heat preservation section. The upper end of the rod pulling rod group is inserted into the crucible to a depth not exceeding the length of the solidification section.

[0010] The length of the heat preservation section accounts for 1 / 2 to 2 / 3 of the length of the crucible, and the length of the solidification section accounts for 1 / 3 to 1 / 2 of the length of the crucible.

[0011] The beneficial effect of adopting the above further solution is that by setting the heat preservation section and the solidification section, it is convenient to further heat the molten droplets dripping into the crucible and solidify them at the bottom of the crucible at the upper end of the rod pulling rod group.

[0012] Further, the crucible heating part includes an induction coil. The induction coil is arranged around the outer side wall of the heat preservation section and passes through the smelting cavity to be connected to a power supply.

[0013] Further, a clamping interface is provided at the upper end of the rod pulling rod group, and the raw material ingot solution in the crucible can be solidified and clamped in the clamping interface.

[0014] Further, the rod pulling rod group includes a rod pulling rod body and a rod pulling rod head. The moving end of the rod pulling mechanism is connected to the lower end of the rod pulling rod body. The rod pulling rod head is detachably and hermetically connected to the upper end of the rod pulling rod body, and the rod pulling rod head can be adaptively inserted into the lower opening of the crucible.

[0015] The beneficial effect of adopting the above further solution is that by setting the rod pulling rod body and the rod pulling rod head that are detachably and hermetically connected, it is convenient to replace different rod pulling rod heads according to the rod pulling requirements.

[0016] Further, the rod pulling rod body is of a hollow structure. A cooling water pipe is arranged in the hollow structure of the rod pulling rod body. The lower end of the cooling water pipe is hermetically passed through the lower end of the rod pulling rod body and serves as a cooling water inlet. A return water gap is reserved between the upper end of the cooling water pipe and the rod pulling rod head. An annular return water interval is formed between the cooling water pipe and the rod pulling rod body. A water return port is arranged on the outer side wall of the lower end of the rod pulling rod body.

[0017] The beneficial effects of adopting the above further scheme are as follows: By arranging the cooling water pipe, a double-layer water-cooling structure can be formed between the cooling water pipe and the rod pulling rod body. The cooling water enters through the central cooling water pipe, reaches the rod head of the rod pulling rod, and then returns through the annular water return interval formed between the side wall and the cooling water pipe, realizing the cooling of the rod head and the rod body of the rod pulling rod.

[0018] Further, the crucible is a cylindrical structure with a uniformly consistent inner diameter from top to bottom;

[0019] The conical heating part includes a conical coil;

[0020] A first vacuum gate valve for controlling on-off is provided between the feeding cavity and the melting cavity; a second vacuum gate valve for controlling on-off is provided between the melting cavity and the rod pulling cavity.

[0021] The beneficial effects of adopting the above further scheme are as follows: By arranging the first vacuum gate valve and the second vacuum gate valve, it is convenient to perform on-off operations on the feeding cavity, the melting cavity, and the rod pulling cavity, realizing non-interference in loading raw material ingots, melting, and taking finished rod materials. Each cavity can be independently evacuated, greatly saving the evacuation time, enabling multiple rod materials to be continuously pulled out after loading the raw materials once, with high preparation efficiency; compared with existing forging and machining, the utilization rate of raw material ingots is higher and the cost is lower.

[0022] Further, the feeding mechanism includes a first lead screw-nut driving part, a cylinder, a clamping connecting rod, and a mounting pipe. The driving end of the first lead screw-nut driving part is connected to and drives the cylinder and the mounting pipe to move up and down. The mounting pipe is arranged vertically. The lower end of the mounting pipe seals and passes through the feeding cavity and is located inside the feeding cavity. The output shaft of the cylinder penetrates downward through the mounting pipe and is hinged to the upper end of the clamping connecting rod. The lower end of the mounting pipe is connected with an assembly plate. The middle part of the clamping connecting rod is hinged to the assembly plate. The lower end of the clamping connecting rod forms a clamping feeding end for clamping the raw material ingot;

[0023] The rod pulling mechanism includes a second lead screw-nut driving part. The driving end of the second lead screw-nut driving part is connected to the rod pulling rod group and drives the rod pulling rod group to move up and down.

[0024] A rod pulling method using the above cold crucible drip melting rod pulling device includes the following steps:

[0025] S1, install the raw material ingot at the feeding end of the feeding mechanism, evacuate the feeding cavity, the melting cavity, and the rod pulling cavity respectively and introduce inert gas;

[0026] S2. Use the feeding mechanism to transport the raw material ingot downward into the melting cavity, and move it from the flared end of the conical heating part into the conical heating part. The conical heating part heats the raw material ingot to melt the lower end of the raw material ingot. The raw material ingot solution continuously drips from the closed end of the conical heating part into the crucible and solidifies and is clamped and fixed at the upper end of the rod pulling mechanism.

[0027] S3. The rod pulling mechanism pulls the rod downward. After the first rod is pulled, close the feeding cavity and the melting cavity, and open the rod pulling cavity to take the material.

[0028] S4. Evacuate the rod pulling cavity again and introduce inert gas, and repeat the operation to continue pulling the second rod.

[0029] The beneficial effect of the present invention is that the rod pulling method of the present invention has a simple process. By setting the power of the power supply, the feeding speed and the rod pulling speed in advance, the process automation can be achieved to complete the rod pulling, and no personnel operation is required during the rod pulling process.

[0030] In S1, the lower end of the raw material ingot is provided with a conical surface.

[0031] In S2, the feeding speed of the raw material ingot is 0.2 - 20 mm / min.

[0032] In S3, the rod pulling speed of the rod pulling mechanism is 0.5 - 50 mm / min.

[0033] The beneficial effect of adopting the above further scheme is that the lower end of the raw material ingot is set as a conical surface, which is convenient for heating, and the molten droplets can drip into the crucible along the conical tip. Description of the Drawings

[0034] Figure 1 It is a schematic cross-sectional structure diagram of the cold crucible drip melting rod pulling device of the present invention;

[0035] Figure 2 It is Figure 1 The enlarged structure diagram of part A in

[0036] Figure 3 It is Figure 1 The enlarged structure diagram of part B in

[0037] Figure 4 It is Figure 1 The enlarged structure diagram of part C in

[0038] Figure 5 It is Figure 1 The enlarged structure diagram of part D in

[0039] Figure 6 It is Figure 1 The enlarged structure diagram of part E in

[0040] Figure 7 It isFigure 1 Schematic diagram of the enlarged structure of the F part in the middle.

[0041] In the attached drawings, the list of components represented by each reference numeral is as follows:

[0042] 100, feeding cavity; 101, raw material ingot; 102, first vacuum gate valve;

[0043] 200, melting cavity; 201, second vacuum gate valve;

[0044] 300, rod pulling cavity;

[0045] 400, feeding mechanism; 401, first motor; 402, first nut; 403, first lead screw; 404, first slide rail; 405, first slider; 406, first connecting plate; 407, cylinder; 408, mounting pipe; 409, clamping connecting rod; 410, assembly plate;

[0046] 500, crucible; 501, induction coil;

[0047] 600, conical coil;

[0048] 700, rod pulling mechanism; 701, second motor; 702, second nut; 703, second lead screw; 704, second slide rail; 705, second slider; 706, second connecting plate;

[0049] 800, rod pulling rod group; 801, rod pulling rod body; 802, rod pulling rod head; 803, card interface; 804, sealing ring; 805, cooling water pipe; 806, cooling water inlet; 807, annular return water interval; 808, water return port. Specific implementation mode

[0050] The principles and features of the present invention will be described below in conjunction with the attached drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0051] As Figures 1 to 7 shown, a cold crucible drip melting rod pulling device of this embodiment includes a feeding cavity 100, a melting cavity 200, a rod pulling cavity 300, a feeding mechanism 400, a crucible 500, a conical heating part, a rod pulling mechanism 700 and a rod pulling rod group 800. The feeding cavity 100 and the rod pulling cavity 300 are respectively installed at the upper end and the lower end of the melting cavity 200 and are both communicated with the melting cavity 200;

[0052] The feeding end of the feeding mechanism 400 is located within the feeding cavity 100 and is used to transport the raw material ingots downward into the melting cavity 200; the conical heating part and the crucible 500 are installed vertically within the melting cavity 200. The upper opening of the crucible 500 corresponds to the closed end of the conical heating part and receives the molten solution of the raw material ingots heated and melted by the conical heating part. The flared end of the conical heating part is arranged corresponding to the feeding end and conducts annular conical heating on the fed raw material ingots 101; the upper end of the rod pulling rod group 800 is located within the rod pulling cavity 300 and can be adaptively inserted into the lower opening of the crucible 500. The moving end of the rod pulling mechanism 700 is connected to the lower end of the rod pulling rod group 800 and drives the rod pulling rod group 800 to move up and down for rod pulling.

[0053] The crucible 500 used in this embodiment is a water-cooled copper crucible. The upper part of the water-cooled copper crucible is a water-cooling jacket, and the lower part is the crucible body. It adopts a split water-cooling structure, and a crucible water shaft communicating with the upper water-cooling structure of the water-cooled copper crucible can be arranged within the melting cavity 200.

[0054] As Figure 4 shown, a crucible heating part is further provided within the melting cavity 200 of this embodiment. The crucible 500 includes a heat preservation section and a solidification section integrally connected in sequence from top to bottom. The crucible heating part is connected to the heat preservation section and further melts and keeps warm the molten solution of the raw material ingots dripping into the heat preservation section. The depth of the upper end of the rod pulling rod group 800 inserted into the crucible 500 does not exceed the length of the solidification section; by providing the heat preservation section and the solidification section, it is convenient to further heat the droplets dripping into the crucible and solidify them at the bottom of the crucible at the upper end of the rod pulling rod group.

[0055] Optionally, the length of the heat preservation section accounts for 1 / 2 to 2 / 3 of the length of the crucible 500, preferably 2 / 3, which can further melt and keep warm the molten droplets of the raw material ingots. The length of the solidification section accounts for 1 / 3 to 1 / 2 of the length of the crucible 500. Further melting and heat preservation are carried out in the water-cooled copper crucible. By pulling the rod downward through the rod pulling mechanism, the melt enters the solidification and crystallization area for solidification. Continuous feeding and continuous rod pulling result in a rod with uniform, dense, and crack-free structure and good surface quality. The entire process can be completed in a vacuum argon filling environment. Using a water-cooled copper crucible for melting, the prepared rod has no oxidation or other pollution.

[0056] As Figure 4 shown, the crucible heating part of this embodiment includes an induction coil 501. The induction coil 501 is wound around the outer side wall of the heat preservation section and passes through the melting cavity 200 to be connected to a power source. The upper end of the rod pulling assembly is inserted into the solidification section. There is no induction coil wound around the solidification section. The upper end of the rod pulling assembly is the same size as the inner diameter of the crucible 500. Crucibles with different inner diameters can cooperate with corresponding rod pulling assemblies to pull out rods with corresponding outer diameter sizes.

[0057] AsFigure 5 As shown in the figure, a clamping interface 803 is provided at the upper end of the rod pulling rod group 800 of this embodiment, and the raw material ingot solution in the crucible 500 can solidify and be clamped in the clamping interface 803.

[0058] As Figure 5 and Figure 6 shown in the figure, the rod pulling rod group 800 of this embodiment includes a rod pulling rod body 801 and a rod pulling rod head 802. The mobile end of the rod pulling mechanism 700 is connected to the lower end of the rod pulling rod body 801. The rod pulling rod head 802 is detachably and hermetically connected to the upper end of the rod pulling rod body 801, and the rod pulling rod head 802 can be adaptively inserted into the lower opening of the crucible 500. By providing a detachably and hermetically connected rod pulling rod body and rod pulling rod head, it is convenient to replace different rod pulling rod heads according to the rod pulling requirements.

[0059] As Figure 5 and Figure 6 shown in the figure, the rod pulling rod body 801 of this embodiment is a hollow structure. A cooling water pipe 805 is provided in the hollow structure of the rod pulling rod body 801. The lower end of the cooling water pipe 805 is hermetically penetrated out from the lower end of the rod pulling rod body 801 and serves as a cooling water inlet 806. A return water gap is reserved between the upper end of the cooling water pipe 805 and the rod pulling rod head 802. An annular return water interval 807 is formed between the cooling water pipe 805 and the rod pulling rod body 801. A return water port 808 is provided on the outer side wall of the lower end of the rod pulling rod body 801. By providing a cooling water pipe, a double-layer water cooling structure can be formed with the rod pulling rod body. Cooling water enters through the central cooling water pipe, enters the rod pulling rod head, and then returns through the annular return water interval formed between the side wall and the cooling water pipe, realizing the cooling of the rod pulling rod head and the rod pulling rod body.

[0060] In this embodiment, the rod pulling rod head 802 and the rod pulling rod body 801 are connected by threads and sealed by a sealing ring 804. A clamping interface is machined at the center of the top of the rod pulling head. The clamping interface can preferably be a threaded port. After the molten liquid enters the threaded port and solidifies, the connection is realized, and the rod can be pulled downward. After the rod pulling is completed, manually rotating the rod can realize the separation between the rod and the rod pulling rod head 802.

[0061] As Figure 4 shown in the figure, a preferred solution of this embodiment is that the crucible 500 is a cylindrical structure with a uniform inner diameter up and down; optionally, as Figure 4 shown in the figure, the conical heating part includes a conical coil 600.

[0062] As Figure 1As shown in the figure, specifically, a first vacuum gate valve 102 for controlling on-off is provided between the feeding cavity 100 and the melting cavity 200; a second vacuum gate valve 201 for controlling on-off is provided between the melting cavity 200 and the rod pulling cavity 300. By providing the first vacuum gate valve and the second vacuum gate valve, it is convenient to perform on-off operations on the feeding cavity, the melting cavity, and the rod pulling cavity, realizing non-interference in loading raw material ingots, melting, and taking finished rod materials. Each cavity can be independently evacuated, greatly saving the evacuation time, enabling continuous pulling of multiple rod materials with a single loading of raw materials, and having high preparation efficiency; compared with existing forging and machining, the utilization rate of raw material ingots is higher and the cost is lower.

[0063] As Figure 1 and Figure 2 As shown in the figure, a specific solution of this embodiment is that the feeding mechanism 400 includes a first lead screw nut driving part, a cylinder 407, a clamping connecting rod 409, and a mounting tube 408. The driving end of the first lead screw nut driving part is connected to and drives the cylinder 407 and the mounting tube 408 to move up and down. The mounting tube 408 is vertically arranged. The lower end of the mounting tube 408 is hermetically passed through the feeding cavity 100 and is located inside the feeding cavity 100. The output shaft of the cylinder 407 penetrates downward through the mounting tube 408 and is hinged to the upper end of the clamping connecting rod 409. The lower end of the mounting tube 408 is connected with an assembly plate 410. The middle part of the clamping connecting rod 409 is hinged on the assembly plate 410. The lower end of the clamping connecting rod 409 forms a clamping and feeding end for clamping the raw material ingot 101. The clamping connecting rod 409 can adopt a scissor fork structure form. The upper ends of the scissor fork structure form are respectively hinged to one ends of two connecting rods. The other ends of the two connecting rods are hinged to the output shaft of the cylinder 407. The middle hinge shaft of the scissor fork structure form is hinged on the assembly plate 410. The lower end of the scissor fork structure form forms a clamping and feeding end.

[0064] Specifically, as Figures 1 to 3 As shown in the figure, the first lead screw nut driving part of this embodiment includes a first motor 401, a first nut 402, a first lead screw 403, a first slide rail 404, and a first slider 405. The lower end of the first slide rail 404 is fixed to the top of one side of the feeding cavity 100. The first motor 401 is installed on the top of the first slide rail 404. The upper end of the first lead screw 403 is fixedly connected to the output shaft of the first motor 401. The lower end of the first lead screw 403 is rotatably connected to the top of the feeding cavity 100. The first lead screw 403 and the first slide rail 404 are arranged in parallel at an interval. The first nut 402 is threadedly connected to the first lead screw 403. The first slider 405 is slidably connected to the first slide rail 404. The first nut 402 is fixedly connected to the first slider 405. A first connecting plate 406 is further connected to the first nut 402. The cylinder 407 is installed on the first connecting plate 406.

[0065] As Figure 6 and Figure 7 shown, the rod pulling mechanism 700 includes a second lead screw nut driving part, and the driving end of the second lead screw nut driving part is connected to the rod pulling rod group 800 and drives the rod pulling rod group 800 to move up and down.

[0066] Specifically, as Figure 6 shown, the second lead screw nut driving part includes a second motor 701, a second nut 702, a second lead screw 703, a second slide rail 704, and a second slider 705. The bottom of the rod pulling cavity 300 is provided with the second slide rail 704, and the upper end of the second slide rail 704 is fixedly connected to the bottom of the rod pulling cavity 300. The second motor 701 is fixed at the lower end of the second slide rail 704. The second lead screw 703 is arranged in parallel and at intervals with the second slide rail 704. The output shaft of the second motor 701 is fixedly connected to the lower end of the second lead screw 703. The upper end of the second lead screw 703 is rotatably connected to the bottom of the rod pulling cavity 300. The second lead screw 703 is threadedly connected with the second nut 702. The second nut 702 is connected with the second slider 705. The second slider 705 is slidably connected to the second slide rail 704. The second nut 702 is further connected with a second connecting plate 706. The lower end of the rod pulling rod group 800 is connected to the second connecting plate 706.

[0067] In this embodiment, both the feeding mechanism 400 and the rod pulling mechanism 700 adopt motors to drive the lead screws to act. The corresponding feeding speed and rod pulling speed can be set according to the types of raw material ingots. The guiding adopts the structure of guide rail and slider, with good structural stiffness and stable guiding. The lower end of the raw material ingot is processed into a conical tip, and the edge is inserted into the conical coil for melting. The upper end of the raw material ingot can be clamped on the clamping connecting rod 409 of the feeding mechanism, and the centering and clamping are realized by driving the clamping connecting rod 409 through the air cylinder, and raw material ingots of various sizes and specifications can be clamped. The melting of the raw material ingot adopts conical coil induction heating. The feeding mechanism smoothly sends the raw material ingot into the conical coil, and the conical coil is connected to an external induction heating power supply. The conical coil melts the conical surface of the raw material ingot through induction heating to form molten drops, and the molten drops drip along the conical tip. As the feeding mechanism continuously feeds the raw material ingot into the conical coil, the ingot is continuously melted, and the molten drops can continuously drip into the water-cooled copper crucible below. By melting and dripping into the crucible, the inner diameter of the crucible can be reduced, without being limited by the raw material size, and small-diameter rods can be drawn.

[0068] In the cold crucible drop melting and rod pulling device of this embodiment, the feeding mechanism sends the raw material ingot into the conical heating part, the lower end of the raw material ingot is melted by induction heating, and the molten drops continuously drip into the crucible (optionally a water-cooled copper crucible). The lower end of the raw material ingot is melted by induction heating through the conical heating part to form molten drops, and the molten drops drip into the crucible, so that the inner diameter of the crucible can be reduced, without being limited by the raw material size, and small-diameter rods can be drawn.

[0069] This embodiment also provides a rod drawing method using the above-mentioned cold crucible drip melting rod drawing device, including the following steps:

[0070] S1. Install the raw material ingot 101 at the feeding end of the feeding mechanism 400, evacuate the feeding cavity 100, the melting cavity 200, and the rod drawing cavity 300 respectively and introduce an inert gas, such as argon;

[0071] S2. Use the feeding mechanism 400 to transport the raw material ingot 101 downward into the melting cavity 200, and move it from the flared end of the conical heating part into the conical heating part. The conical heating part heats the raw material ingot 101 to melt the lower end of the raw material ingot 101. The raw material ingot solution continuously drips into the crucible from the closed end of the conical heating part, and solidifies and is clamped and fixed at the upper end of the rod drawing mechanism 700;

[0072] S3. The rod drawing mechanism 700 draws the rod downward. After the first rod is drawn, close the feeding cavity 100 and the melting cavity 200, and open the rod drawing cavity 300 to take the material;

[0073] S4. Evacuate the rod drawing cavity 300 again and introduce an inert gas, and repeat the operation to continue drawing the second rod.

[0074] In S1, the lower end of the raw material ingot 101 is provided with a conical surface; the lower end of the raw material ingot 101 is set as a conical surface, which is convenient for heating, and the molten droplets can drip into the crucible 500 along the cone tip.

[0075] In S2, the feeding speed of the raw material ingot 101 is 0.2 - 20 mm / min;

[0076] In S3, the rod drawing speed of the rod drawing mechanism 700 is 0.5 - 50 mm / min.

[0077] In the rod pulling method of this embodiment, after the raw material ingot solution is heated and kept warm in a water-cooled copper crucible, it descends through the rod pulling mechanism and enters the solidification and crystallization zone (solidification section) for solidification. The feeding mechanism continuously feeds materials into the conical coil, and the molten droplets continuously drip into the water-cooled copper crucible to supplement the molten solution. The rod pulling mechanism can continuously pull the rod downward. After setting the feeding speed and the rod pulling speed, continuous automatic rod pulling can be achieved until a rod is completed. The feeding speed and the rod pulling speed need to be set according to the material composition of the raw material ingot, the diameter of the raw material ingot, and the diameter of the pulled rod. The preparation process of this rod pulling method is simple. By setting the power of the power supply, the feeding speed, and the rod pulling speed in advance, the process automation for rod pulling can be achieved, and no personnel operation is required during the process. A loading cavity, a melting cavity, and a rod pulling cavity are set up, and the two cavities are separated by a vacuum gate valve, realizing that loading raw materials, melting, and taking finished products do not interfere with each other. Each cavity can be evacuated separately, greatly saving the vacuum pumping time, enabling multiple rods to be continuously pulled out after loading the raw materials once, and the preparation efficiency is high. Compared with forging and machining, the raw material utilization rate is high and the cost is low.

[0078] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0079] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0080] In the present invention, unless otherwise clearly specified and limited, the terms such as "mounted", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] In the present invention, unless otherwise clearly defined and limited, a first feature being "on" or "under" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact via an intermediate medium. Moreover, a first feature being "above", "over" and "on top of" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. A first feature being "under", "below" and "beneath" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is less than that of the second feature.

[0082] In the description of this specification, the description with reference to terms such as "an embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0083] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A rod pulling method, characterized in that: The cold crucible drip melting and rod drawing device is adopted, and the cold crucible drip melting and rod drawing device comprises a feeding cavity, a smelting cavity, a rod drawing cavity, a feeding mechanism, a crucible, a conical heating part, a rod drawing mechanism and a rod drawing rod group, wherein the feeding cavity and the rod drawing cavity are respectively installed at the upper end and the lower end of the smelting cavity and are both connected with the smelting cavity; the feeding end of the feeding mechanism is located in the feeding cavity and is used to transport the raw material ingot downward into the smelting cavity; the conical heating part and the crucible are installed in the smelting cavity from top to bottom, the upper opening of the crucible corresponds to the closing end of the conical heating part and receives the raw material ingot solution heated and dripped by the conical heating part, the flared end of the conical heating part is arranged corresponding to the feeding end and performs annular conical heating on the fed raw material ingot; the upper end of the rod drawing rod group is located in the rod drawing cavity and can be adapted to be inserted into the lower opening of the crucible, the moving end of the rod drawing mechanism is connected to the lower end of the rod drawing rod group and drives the rod drawing rod group to move up and down to draw the rod; The rod puller assembly includes a rod puller body and a rod puller head, the movable end of the rod puller mechanism is connected to the lower end of the rod puller body, the rod puller head is detachably and sealedly connected to the upper end of the rod puller body, and the rod puller head can be adapted to be inserted into the lower opening of the crucible; The crucible is a cylindrical structure with a uniform inner diameter from top to bottom; the conical heating part includes a conical coil; a first vacuum gate valve for controlling on and off is provided between the feeding cavity and the smelting cavity; a second vacuum gate valve for controlling on and off is provided between the smelting cavity and the rod drawing cavity; Rod pulling method The following steps are involved: S1, installing the raw material ingot on the feeding end of the feeding mechanism, evacuating the feeding cavity, the smelting cavity and the rod drawing cavity respectively and introducing inert gas; the lower end of the raw material ingot is provided with a conical surface; S2, using a feeding mechanism to transport the raw material ingot downward into the smelting chamber, and moving it from the expanded end of the conical heating part into the conical heating part, the conical heating part heats the raw material ingot to melt the lower end of the raw material ingot, and the raw material ingot solution continuously drips into the crucible from the closing end of the conical heating part, solidifies at the upper end of the rod pulling mechanism and is clamped and fixed; the conveying speed of the raw material ingot is 0.2~20mm / min; S3, the rod pulling mechanism pulls the rod downwards. After the first rod is pulled, the feeding chamber and the smelting chamber are closed, and the rod pulling chamber is opened to take out the material; the rod pulling speed of the rod pulling mechanism is 0.5~50mm / min; S4, the rod pulling cavity is evacuated again and inert gas is introduced, and the cycle operation is continued for the second rod pulling.

2. A rod drawing method according to claim 1, characterized in that: The smelting cavity is also provided with a crucible heating part, the crucible includes a heat preservation section and a solidification section which are connected in sequence from top to bottom, the crucible heating part is connected to the heat preservation section and further melts and keeps warm the raw material ingot solution dripping into the heat preservation section, and the depth of the upper end of the rod pulling group inserted into the crucible does not exceed the length of the solidification section; The length of the heat preservation section accounts for 1 / 2 to 2 / 3 of the length of the crucible, and the length of the solidification section accounts for 1 / 3 to 1 / 2 of the length of the crucible.

3. A rod drawing method according to claim 2, characterized in that: The crucible heating part comprises an induction coil, which is arranged on the outer wall of the heat preservation section and passes through the smelting cavity to be connected with a power source.

4. A rod drawing method according to claim 1, characterized in that: A clamping interface is provided at the upper end of the rod pulling rod group, and the raw material ingot solution in the crucible can be solidified and clamped in the clamping interface.

5. A rod drawing method according to claim 1, characterized in that: The rod puller body is a hollow structure, and a cooling water pipe is arranged in the hollow structure of the rod puller body. The lower end of the cooling water pipe is sealed and passes through the lower end of the rod puller body and serves as a cooling water inlet. A return water gap is reserved between the upper end of the cooling water pipe and the rod puller head, and an annular return water gap is formed between the cooling water pipe and the rod puller body. A return water port is arranged on the outer side wall of the lower end of the rod puller body.

6. A rod drawing method according to claim 1, characterized in that: The feeding mechanism comprises a first screw nut driving part, a cylinder, a clamping connecting rod and a mounting tube, the driving end of the first screw nut driving part is connected to and drives the cylinder and the mounting tube to move up and down, the mounting tube is arranged vertically, the lower end of the mounting tube is sealed and passes through the feeding cavity and is located in the feeding cavity, the output shaft of the cylinder passes through the mounting tube downward and is hinged to the upper end of the clamping connecting rod, the lower end of the mounting tube is connected to a mounting plate, the middle part of the clamping connecting rod is hinged to the mounting plate, and the lower end of the clamping connecting rod forms a clamping feeding end for clamping the raw material ingot; The rod pulling mechanism comprises a second lead screw nut driving part, a driving end of which is connected to the rod pulling rod group and drives the rod pulling rod group to move up and down.

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