A smelting stirring mechanism

Abstract

The utility model discloses a smelting stirring mechanism, including furnace cover plate, stirring device and elevating gear, and furnace cover plate is equipped with furnace cover hole, and furnace cover plate is equipped with cooling water jacket, and stirring device includes support plate, driving motor, motor shaft sleeve, metal pole, connecting screw bush, graphite pole and graphite stirring vane, and the connecting place of the upper end of metal pole and cooling water jacket is equipped with upper dynamic sealing unit, and the connecting place of the lower end of metal pole and cooling water jacket is equipped with lower dynamic sealing unit. The above -mentioned mechanism has increased cooling water jacket on furnace cover plate, makes equipment to be able to obtain cooling, improves its ability to bear the high temperature that the radiant heat and heat conduction of metal liquid bring, and metal pole and cooling water jacket are connected together through dynamic sealing unit, can effectively prevent air leakage and destroy vacuum, and the whole mechanism only graphite stirring vane and part graphite pole directly contact metal liquid, and metal liquid is not polluted by stirring mechanism, eliminates the risk that gold and silver jewelry color is influenced.

Description

Technical Field

[0001] This utility model relates to the field of stirring equipment technology, specifically to a smelting stirring mechanism. Background Technology

[0002] In the production of gold and silver jewelry, ensuring uniform composition and avoiding uneven composition within the same batch of products that leads to substandard purity is a common problem faced by jewelry companies. The usual practice is to melt the metal at atmospheric pressure using a torch or induction furnace, then manually stir it with a glass rod to ensure complete homogenization before casting it into ingots. This method is relatively simple, but the metallurgical quality of the molten metal is poor, making it prone to oxidation by absorbing gases, especially for highly reactive alloying elements. This results in significant losses and oxide inclusions during the melting process. Therefore, vacuum melting or vacuum + protective atmosphere melting is generally required. Existing vacuum melting equipment typically involves installing an induction coil within the melting chamber, sealing the chamber with a furnace lid to create a vacuum, or evacuating to the required vacuum level and then filling it with an inert gas at a certain pressure. This melting environment greatly reduces the chance of oxidation by absorbing gases in the molten metal, making it more suitable for highly reactive metals. Although induction melting theoretically provides some electromagnetic stirring, gold and silver jewelry products are relatively small, and the amount melted at one time is generally small. Most melting equipment is equipped with medium-frequency or high-frequency power supplies, limiting the electromagnetic stirring effect. Therefore, relying solely on electromagnetic stirring often results in uneven coloring. Mechanical stirring is a more reliable and effective method, but because gold and silver jewelry casting equipment is inherently small, and the molten metal needs to be poured from the crucible into molds or ingot molds after melting, equipping it with a mechanical stirring mechanism that effectively stirs the molten metal without interfering with the pouring process presents considerable technical challenges.

[0003] Several studies have been reported on how to perform stirring under vacuum melting conditions. For example, Chinese patent CN202420763795.0 discloses a stirring mechanism for a vacuum melting furnace, Chinese patent CN202421402644.9 discloses a stirring device for vacuum atomization melting with a fixing frame having side walls and a top wall, Chinese patent CN202420773344.5 discloses a composite stirring device for alloy melting, and Chinese patent CN202420918226.9 discloses a special stirring and sealing device for vacuum melting furnaces. However, these technologies are all designed for their respective equipment conditions and differ significantly from equipment used for melting and casting gold and silver jewelry. Utility Model Content

[0004] In order to overcome the shortcomings of the prior art, this utility model provides a melting and stirring mechanism to solve the above-mentioned traditional problems.

[0005] This utility model is achieved using the following technical solution:

[0006] A smelting stirring mechanism includes a furnace cover plate, a stirring device and a lifting device disposed on the furnace cover plate. The furnace cover plate has a furnace cover hole in the middle and a cooling water jacket is disposed above the furnace cover plate. The stirring device includes a support plate, a drive motor mounted on the support plate, a motor bushing, a metal rod, a connecting screw sleeve, a graphite rod and a graphite stirring blade. The drive motor is connected to the metal rod through the motor bushing. An upper dynamic sealing unit is provided at the connection between the upper end of the metal rod and the cooling water jacket, and a lower dynamic sealing unit is provided at the connection between the lower end of the metal rod and the cooling water jacket. The metal rod passes through the furnace cover hole and is connected to the graphite rod through the connecting screw sleeve. The graphite stirring blade is mounted on the graphite rod. The lifting device includes a lifting cylinder and a cylinder rod, and the cylinder rod is connected to the support plate.

[0007] Preferably, the top of the cooling water jacket is provided with a water jacket end cap, which is fixed to the cooling water jacket by fastening bolts.

[0008] Preferably, the water jacket end cap is fastened to the cooling water jacket by an O-ring seal.

[0009] Preferably, a metal filter nozzle is installed on the outer end face of the water jacket end cap.

[0010] Preferably, the lower end of the cooling water jacket is provided with a water inlet pipe, and the upper end of the cooling water jacket is provided with a water outlet pipe.

[0011] Preferably, the drive motor is a variable frequency motor.

[0012] Preferably, the cylinder rod is connected to the support plate via a support base, and the top surface of the lifting cylinder is provided with a positioning screw.

[0013] Preferably, the lifting device includes a first lifting device and a second lifting device, which are located on opposite sides of the cooling water jacket.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0015] The smelting and stirring mechanism of this utility model optimizes the structure of the furnace cover plate, stirring device, and lifting device. A cooling water jacket is added to the furnace cover plate to cool the furnace cover plate, metal rod, and other equipment, improving their ability to withstand the radiant heat and high temperatures caused by heat conduction from the molten metal. The metal rod and the cooling water jacket are connected together through a dynamic sealing unit, which can effectively prevent air leakage from breaking the vacuum. Only the graphite stirring blade and part of the graphite rod are in direct contact with the molten metal in the entire mechanism, so the molten metal is not contaminated by the stirring mechanism, eliminating the risk of affecting the purity of gold and silver jewelry, and achieving stable and uniform stirring of the molten metal when smelting gold and silver jewelry alloys in a vacuum environment. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the melting and stirring mechanism of this utility model.

[0017] In the diagram: 1. Motor; 2. Motor bushing; 3. Countersunk screw; 4. Metal filter nozzle; 5. Upper dynamic sealing unit; 6. Sealing ring; 7. Second air outlet pipe; 8. Water outlet pipe; 9. Second lifting device; 10. Metal rod; 11. Lower dynamic sealing unit; 12. Cooling water jacket; 13. Water inlet pipe; 14. Second air inlet pipe; 15. Furnace cover plate; 16. Support plate; 17. Support base; 18. Positioning screw; 19. Cylinder rod; 20. Water jacket end cap; 21. Fastening bolt; 22. First air outlet pipe; 23. First lifting device; 24. First air inlet pipe; 25. Connecting screw sleeve; 26. Graphite rod; 27. Graphite stirring blade. Detailed Implementation

[0018] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0019] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0020] In the description of this utility model, it should be understood that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be intermediate elements present. Conversely, when an element is referred to as being "directly" connected to another element, there are no intermediate elements.

[0021] Please see Figure 1 A melting and stirring mechanism is provided for installation in a jewelry vacuum casting machine. The jewelry vacuum casting machine includes a melting chamber. The melting and stirring mechanism is sealed to the melting chamber by a heat-resistant rubber ring on the end face, so that the melting chamber is sealed and a vacuum environment is formed. The melting and stirring mechanism can be configured as a flip-top structure or other forms of structure.

[0022] Specifically, the smelting and stirring mechanism includes a furnace cover plate 15, a stirring device and a lifting device mounted on the furnace cover plate 15. The furnace cover plate 15 has a furnace cover hole in the middle and a cooling water jacket 12 above the furnace cover plate 15. The stirring device includes a support plate 16, a drive motor mounted on the support plate 16, a motor bushing 2, a metal rod 10, a connecting screw sleeve 25, a graphite rod 26 and a graphite stirring blade 27. The drive motor is connected to the metal rod 10 through the motor bushing 2. An upper dynamic sealing unit 5 is provided at the connection between the upper end of the metal rod 10 and the cooling water jacket 12, and a lower dynamic sealing unit 11 is provided at the connection between the lower end of the metal rod 10 and the cooling water jacket 12. The metal rod 10 passes through the furnace cover hole and is connected to the graphite rod 26 through the connecting screw sleeve 25. The graphite stirring blade 27 is mounted on the graphite rod 26. The lifting device includes a lifting cylinder and a cylinder rod 19. The cylinder rod 19 is connected to the support plate 16. The stirring device moves longitudinally through the action of the lifting cylinder.

[0023] In this embodiment, the central hole of the cooling water jacket 12 is concentric with the furnace cover hole. A water jacket end cap 20 is provided at the top of the cooling water jacket 12, and the end cap 20 is fixed to the cooling water jacket 12 by fastening bolts 21. The end cap 20 is also secured to the cooling water jacket 12 by an O-ring seal 6. A water inlet pipe 13 is provided at the lower end of the cooling water jacket 12, and a water outlet pipe 8 is provided at the upper end of the cooling water jacket 12, ensuring that water flows from bottom to top to improve the heat exchange performance of the cooling water jacket 12. In another embodiment, a metal filter nozzle 4 is installed on the outer end face of the end cap 20 to facilitate water addition and replenishment.

[0024] The drive motor is, but is not limited to, a variable frequency motor, which facilitates speed adjustment. The motor shaft sleeve 2 and the metal rod 10 are positioned by countersunk screws 3. The motor is placed vertically on the support plate 16, so that the upper end of the metal rod 10 is inserted into the variable frequency motor shaft sleeve 2, ensuring the concentricity of the two.

[0025] In the lifting device, the cylinder rod 19 is connected to the support plate 16 via the support base 17. The top surface of the lifting cylinder is provided with a positioning screw 18 to limit the movement of the cylinder rod 19. The lifting device includes a first lifting device 23 and a second lifting device 9, which are located on opposite sides of the cooling water jacket 12. The first lifting device 23 is provided with a first air inlet pipe 24 and a first air outlet pipe 22, and the second lifting device 9 is provided with a second air inlet pipe 14 and a second air outlet pipe 7.

[0026] The graphite stirring blade 27 is threaded to the lower end of the graphite rod 26, and the upper end of the graphite rod 26 is connected to the metal rod 10 through the connecting screw sleeve 25.

[0027] In the above structure, the upper dynamic sealing unit 5 and the lower dynamic sealing unit 11 are existing technologies, such as labyrinth seals or other sealing structures. The specific sealing structure is set as needed, and will not be described in detail here.

[0028] The aforementioned melting and stirring mechanism has a through hole in the furnace cover of the jewelry vacuum casting machine. A cooling water jacket 12 is installed on the furnace cover, and lifting cylinders are symmetrically arranged on both sides of the water jacket. A small variable frequency motor is installed above the cylinders. The metal rod 10 passes through the dynamic sealing units at both ends of the cooling water jacket 12, with the upper end connected to the motor shaft sleeve 2 and the lower end connected to the graphite rod 26. The bottom end of the graphite rod 26 is connected to the graphite stirring blade 27. During melting, the cylinder raises the stirring rod to a high position, adds the metal charge to the graphite crucible, and closes the furnace cover. A vacuum is drawn and a protective gas is introduced to heat the metal charge. After the metal melts, the stirring device is started, and the cylinder sends the stirring blade into the molten metal. The motor drives the stirring blade to rotate, stirring the molten metal to make it uniform. After the graphite stopper rod is lifted, the molten metal is poured, which has the advantages of compact structure, simple operation, uniform stirring, high metallurgical quality, and low precious metal loss.

[0029] In use, first raise the frequency converter motor to drive the graphite stirring blade 27 to rise and leave the crucible cavity. Then, flip the furnace cover open, assemble the graphite stopper rod, add the metal material, close the furnace cover, evacuate the vacuum, fill with argon gas, and start heating. After the metal melts, insert the stirring blade into the crucible and turn on the motor to rotate, which will achieve stirring of the molten metal.

[0030] The above structural design fully considers long-term stability under multiple working conditions such as high temperature, vacuum, and corrosion, as well as the convenience of the smelting and casting process, without increasing the equipment's footprint. The metal rod 10 and the cooling water jacket 12 are connected together through a dynamic sealing unit, which can effectively prevent air leakage from disrupting the vacuum. The cooling water jacket 12 cools the metal rod 10, which can withstand the radiant heat and high temperature caused by heat conduction of the molten metal, preventing oxidation and deformation and ensuring the long-term use of the stirring mechanism. The appropriate speed and stirring position can be set according to the material properties and volume of the molten metal through a variable frequency motor and a limit screw. The symmetrical arrangement of the lifting cylinders allows the stirring rod to rise and fall smoothly, and the dynamic sealing units at both ends of the metal rod 10 can prevent the stirring blade from swaying during rotation, avoiding damage to the stirring blade and air entrapment in the molten metal. High-purity graphite, which is chemically inert to gold and silver jewelry materials, is used to make the graphite rod 26 and the stirring blade. Only the graphite stirring blade 27 and part of the graphite rod 26 directly contact the molten metal in the entire mechanism, preventing the molten metal from being contaminated by the stirring mechanism and eliminating the risk of affecting the purity of the gold and silver jewelry. The graphite stirring rod and stirring blades are connected by threads, making them easy to replace. Therefore, the above mechanism can achieve stable and uniform stirring of molten metal when melting gold and silver jewelry alloys in a vacuum environment.

[0031] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0032] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A melting and stirring mechanism, characterized in that, The device includes a furnace cover plate, a stirring device mounted on the furnace cover plate, and a lifting device. The furnace cover plate has a furnace cover hole in the middle, and a cooling water jacket is provided above the furnace cover plate. The stirring device includes a support plate, a drive motor mounted on the support plate, a motor bushing, a metal rod, a connecting screw sleeve, a graphite rod, and graphite stirring blades. The drive motor is connected to the metal rod through the motor bushing. An upper dynamic sealing unit is provided at the connection between the upper end of the metal rod and the cooling water jacket, and a lower dynamic sealing unit is provided at the connection between the lower end of the metal rod and the cooling water jacket. The metal rod passes through the furnace cover hole and is connected to the graphite rod through the connecting screw sleeve. The graphite stirring blades are mounted on the graphite rod. The lifting device includes a lifting cylinder and a cylinder rod, and the cylinder rod is connected to the support plate.

2. The smelting and stirring mechanism according to claim 1, characterized in that, The top of the cooling water jacket is provided with a water jacket end cap, which is fixed to the cooling water jacket by fastening bolts.

3. The smelting and stirring mechanism according to claim 2, characterized in that, The water jacket end cap is fastened to the cooling water jacket by an O-ring seal.

4. The smelting and stirring mechanism according to claim 2, characterized in that, A metal filter nozzle is installed on the outer end face of the water jacket end cap.

5. The smelting and stirring mechanism according to claim 2, characterized in that, The lower end of the cooling water jacket is provided with a water inlet pipe, and the upper end of the cooling water jacket is provided with a water outlet pipe.

6. The smelting and stirring mechanism according to claim 1, characterized in that, The drive motor is a variable frequency motor.

7. The smelting and stirring mechanism according to claim 1, characterized in that, The cylinder rod is connected to the support plate via a support base, and a positioning screw is provided on the top surface of the lifting cylinder.

8. The smelting and stirring mechanism according to claim 1, characterized in that, The lifting device includes a first lifting device and a second lifting device, which are located on opposite sides of the cooling water jacket.

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