A reverse wire feeding system and method for a grain refiner in high-pressure die casting

Abstract

The present invention discloses a reverse wire feeding system and method for a grain refiner in high-pressure die casting. The system includes a metering furnace, and a riser pipe is provided on the metering furnace. The system further includes a wire feeding mechanism for feeding the grain refiner wire from the outlet end of the riser pipe. By feeding the wire reversely into the riser pipe, the present invention can not only precisely control the addition amount of the grain refiner, but also make full use of the high-temperature environment of the metering furnace and the inclined semi-closed structure of the riser pipe, solving problems such as incomplete melting and insufficient mixing, and improving the die casting efficiency and the quality of die-cast parts.

Description

Technical Field

[0001] The present invention belongs to the field of casting, and specifically relates to a device for adding grain refiners during high-pressure die casting, and also relates to a method for adding grain refiners. Background Art

[0002] The high-pressure die casting process can produce thin-walled aluminum alloy parts, which have very broad application prospects in the fields of aerospace, automotive, shipbuilding, etc. During high-pressure die casting, adding grain refiners (such as intermediate alloys like Al-Ti-B) can improve the tissue distribution and refine the grain size, further enhancing the mechanical properties of the die-cast finished parts.

[0003] In the prior art, there are mainly the following two ways to add grain refiners:

[0004] One way is to add the grain refiner into the side furnace together with the casting material. The molten aluminum produced by melting enters the dosing furnace, and then is injected into the runner through the riser pipe of the dosing furnace, and finally flows into the mold. Although the dosing furnace can accurately control the injection amount of the molten aluminum, the grain refiner particles are prone to agglomeration and sedimentation in the molten aluminum. Therefore, the content of the grain refiner in the molten aluminum entering the dosing furnace from the side furnace has a certain degree of uncertainty, and the grain refiner will agglomerate and sediment again in the dosing furnace. Finally, the content of the grain refiner in the molten aluminum reaching the mold through the riser pipe cannot be accurately controlled, and the performance stability of the die-cast finished product is poor.

[0005] Another commonly used way is to add the grain refiner into the runner online in the form of wire feeding or spoon feeding, and enter the mold along with the flowing molten aluminum. For example, the Chinese utility model patent "Aluminum Liquid Titanium Wire Adding Anti-Sedimentation Device" with the authorization announcement number CN209318734U adopts this method. Although this method can accurately control the addition amount of the grain refiner, after the molten aluminum leaves the dosing furnace, the temperature drops significantly. Therefore, the added grain refiner cannot be completely melted and cannot be fully mixed with the molten aluminum. Finally, the grain refiner entering the mold has the problem of uneven distribution, affecting the quality of the casting. Summary of the Invention

[0006] The present invention provides a reverse wire feeding system and method for grain refiners in high-pressure die casting, and its purpose is to solve the problems that the addition amount of the grain refiner cannot be accurately controlled, the melting is incomplete, and the mixing is insufficient.

[0007] The technical solution of the present invention is as follows:

[0008] A reverse wire feeding system for grain refiners in high-pressure die casting includes a dosing furnace, a riser pipe is provided on the dosing furnace, and further includes a wire feeding mechanism for feeding the grain refiner wire from the outlet end of the riser pipe.

[0009] As a further improvement to the reverse wire feeding system of the grain refiner for high-pressure die casting: It further includes an induction heating device for heating the wire sent out by the wire feeding mechanism and not yet entering the riser tube.

[0010] As a further improvement to the reverse wire feeding system of the grain refiner for high-pressure die casting: The induction heating device includes an induction heating head, a power supply device, and a water cooling device;

[0011] The induction heating head includes a copper tube fixedly placed relative to the metering furnace. The copper tube is wound into a coil shape to form an induction heating channel; The power supply cable led out by the power supply device is connected to the copper tube;

[0012] The water outlet of the water cooling device is connected to one end of the copper tube through a water supply pipeline, and the water return port is connected to the other end of the copper tube through a water return pipeline.

[0013] As a further improvement to the reverse wire feeding system of the grain refiner for high-pressure die casting: A control pedal is provided on the power supply device.

[0014] As a further improvement to the reverse wire feeding system of the grain refiner for high-pressure die casting: The wire feeding mechanism includes a body, and further includes a driving device, a driving wheel, a driven wheel, and a pressing mechanism installed on the body;

[0015] The driving device is in transmission connection with the driving wheel, and the pressing mechanism is used to push the driven wheel closer to the driving wheel to clamp the wire.

[0016] As a further improvement to the reverse wire feeding system of the grain refiner for high-pressure die casting: There are two sets of driving wheels, which are installed on the body by means of rotational connection;

[0017] There are two sets of driven wheels, corresponding to the two sets of driving wheels one by one;

[0018] The pressing mechanism includes a first rotating arm, a second rotating arm, a connecting rod, a rotating sleeve, a spring, and a threaded sleeve;

[0019] Both the first rotating arm and the second rotating arm are installed on the body by means of rotational connection; The two driven wheels are respectively installed at one end of the first rotating arm and one end of the second rotating arm;

[0020] One end of the connecting rod is rotationally connected to the other end of the first rotating arm, and the other end passes through the rotating sleeve and the spring in sequence and is threadedly connected to the threaded sleeve; One end of the spring contacts the rotating sleeve and the other end contacts the threaded sleeve;

[0021] The rotating sleeve is rotationally connected to the other end of the second rotating arm.

[0022] As a further improvement of the reverse wire feeding system for the grain refiner in high-pressure die casting: It further includes a wire spool for winding the wire, and the wire led out from the wire spool is fed into the wire feeding mechanism.

[0023] As a further improvement of the reverse wire feeding system for the grain refiner in high-pressure die casting: The wire spool and the wire feeding mechanism are installed on a support base, and the wire spool is rotatably connected to the support base.

[0024] As a further improvement of the reverse wire feeding system for the grain refiner in high-pressure die casting: The support base is movable.

[0025] The present invention also provides a reverse wire feeding method for the grain refiner in high-pressure die casting:

[0026] Step 1: Use the wire feeding mechanism to deliver the grain refiner wire to the outlet end of the riser tube of the dosing furnace. The wire is first heated by an induction heating device and then enters the riser tube reversely from the outlet end of the riser tube.

[0027] Step 2: When the wire is immersed in the molten metal, it melts under the high temperature of the molten metal. At this time, reduce the speed of delivering the wire; the melted grain refiner is located in the riser tube.

[0028] Step 3: When the melting amount meets the requirements, the wire feeding mechanism acts reversely to withdraw the wire from the riser tube.

[0029] Step 4: The dosing furnace discharges the molten metal from the riser tube, and the melted grain refiner in the riser tube leaves the dosing furnace together with the molten metal and is fully mixed with the molten metal during the discharge process of the molten metal.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The present invention feeds the wire reversely into the riser tube. On the one hand, the addition amount of the wire can be accurately controlled by controlling the speed of the wire feeding mechanism. On the other hand, the melted wire is located in the inclined riser tube and will not spread to the outside of the riser tube. When discharging the liquid, it can ensure that all the melted grain refiner enters the mold without residue, and finally realizes the accurate control of the addition amount of the grain refiner.

[0032] 2. The present invention makes full use of the high-temperature environment in the dosing furnace, so that the wire immersed in the molten metal can be melted quickly and fully, solving the problem of incomplete melting.

[0033] 3. The grain refiner melted in the riser tube is first preliminarily mixed with the molten metal, and will be mixed with the molten metal passing through the riser tube again when discharging the liquid. Through static and dynamic mixing twice, the purpose of full mixing is achieved, and the die casting quality is significantly improved.

[0034] 4. The present invention also preheats the wire by induction heating, further improving the melting speed of the wire, avoiding sedimentation and agglomeration in the riser pipe due to too long melting time, and affecting the die-casting effect.

[0035] 5. The clamping force of the wire feeding mechanism is adjustable, and the wire does not slip during the wire feeding process, ensuring the accuracy of the wire feeding length.

[0036] 6. The system is integrated and can perform automated operations without manual intervention, improving the efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the overall structure of the reverse wire feeding system;

[0038] Figure 2 is a schematic diagram of the wire reversely entering the riser pipe of the metering furnace;

[0039] Figure 3 is a schematic diagram of the structure of the induction heating head;

[0040] Figure 4 is a schematic diagram of the structure of the wire feeding mechanism.

[0041] In the figure:

[0042] 1. Metering furnace; 2. Riser pipe; 3. Induction heating head; 4. Wire feeding mechanism; 5. Support base; 6. Wire; 7. Wire reel; 8. Water cooling device; 9. Power supply device; 3-1. Copper pipe; 3-2. Conduit; 3-3. Body; 4-1. Body; 4-2. Driving wheel; 4-3. Driven wheel; 4-4. First rotating arm; 4-5. Link; 4-6. Rotating sleeve; 4-7. Spring; 4-8. Threaded sleeve; 4-9. Second rotating arm; 4-10. Motor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The technical solution of the present invention will be described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0044] As Figure 1 and 2 , a reverse wire feeding system for grain refiners in high-pressure die casting includes a metering furnace 1, and an inclined riser pipe 2 is provided on the metering furnace 1.

[0045] The reverse wire feeding system for grain refiners further includes a wire reel 7 and a wire feeding mechanism 4. In this embodiment, the wire reel 7 and the wire feeding mechanism 4 are installed on a support base 5, and the wire reel 7 is rotatably connected to the support base 5 and can rotate freely. A moving wheel is provided at the bottom of the support base 5 for easy movement.

[0046] The wire spool 7 is wound with a wire material 6, which can be an Al-Ti-B master alloy or other types of grain refiners. The two sides of the wire spool 7 are detachable discs, which facilitate the picking and placing of the wire material 6 and constrain the position of the wire material 6.

[0047] The wire material 6 led out from the wire spool 7 will be fed into the wire feeding mechanism 4. The wire feeding mechanism 4 is used to feed the grain refiner wire material 6 from the outlet end of the riser pipe 2.

[0048] Specifically, as Figure 4 , the wire feeding mechanism 4 includes a body 4-1, and also includes a driving device, a driving wheel 4-2, a driven wheel 4-3 and a pressing mechanism installed on the body 4-1. The driving wheels 4-2 are in two groups and are installed on the body 4-1 by a rotational connection method. The driven wheels 4-3 are in two groups and correspond to the two groups of driving wheels 4-2 one by one.

[0049] In this embodiment, the driving device is a DC motor 4-10, and the output shaft of the DC motor 4-10 is in transmission connection with the driving wheel 4-2 through a transmission mechanism. The transmission mechanism can be a gear reduction mechanism or a mechanical mechanism composed of gears and a worm and worm gear mechanism. For example, the output shaft of the DC motor 4-10 is connected to a worm, the worm meshes with a worm wheel, the worm wheel is fixedly connected to one of the driving wheels 4-2, and at the same time, this driving wheel 4-2 is in transmission connection with the other driving wheel 4-2 through a synchronous belt. Another example is that the output shaft of the DC motor 4-10 is connected to a first bevel gear, the first bevel gear meshes with a second bevel gear, the second bevel gear is fixedly connected to one of the driving wheels 4-2, and at the same time, this driving wheel 4-2 is in transmission connection with the other driving wheel 4-2 through a synchronous belt.

[0050] The pressing mechanism is used to push the driven wheel 4-3 closer to the driving wheel 4-2 to clamp the wire material 6. In this embodiment, the pressing mechanism includes a first rotating arm 4-4, a second rotating arm 4-9, a connecting rod 4-5, a rotating sleeve 4-6, a spring 4-7 and a threaded sleeve 4-8.

[0051] The middle parts of the first rotating arm 4-4 and the second rotating arm 4-9 are both installed on the body 4-1 by a rotational connection method. The two driven wheels 4-3 are respectively installed at the lower ends of the first rotating arm 4-4 and the second rotating arm 4-9.

[0052] One end of the connecting rod 4-5 is rotatably connected to the other end of the first rotating arm 4-4, and the other end passes through the rotating sleeve 4-6 and the spring 4-7 in sequence and is threadedly connected to the threaded sleeve 4-8. One end of the spring 4-7 contacts the rotating sleeve 4-6, and the other end contacts the threaded sleeve 4-8. The rotating sleeve 4-6 is rotatably connected to the other end of the second rotating arm 4-9.

[0053] By rotating the threaded sleeve 4-8, the compression amount of the spring 4-7 can be changed, and the forces on the upper ends of the first rotating arm 4-4 and the second rotating arm 4-9 can be adjusted, so as to change the clamping force between the driven wheel 4-3 and the driving wheel 4-2.

[0054] The outer edge contours of the driven wheel 4-3 and the driving wheel 4-2 can be arc-shaped, square groove-shaped, V-shaped, etc. The cross-sectional size of the wire 6 is 3-10 mm, and the wire feeding speed is adjustable from 1-15 m / min. When in use, the parameters on the control panel connected to the DC motor 4-10 are adjusted to change the running speed of the driving wheel 4-2, so as to change the wire feeding speed of the wire 6.

[0055] Furthermore, the grain refiner reverse wire feeding system further includes an induction heating device for heating the wire 6 sent out by the wire feeding mechanism 4 and not yet entering the riser tube 2.

[0056] Such as Figure 1 and 3 As shown in, the induction heating device includes an induction heating head 3, a power supply device 9 and a water cooling device 8.

[0057] The induction heating head 3 includes a body 3-3 fixedly placed relative to the metering furnace 1. A conduit 3-2 (hose) is installed on the body 3-3 through a support frame. A copper tube 3-1 wound in a coil shape is provided on the front side of the conduit 3-2, and the copper tube 3-1 wound in a coil shape constitutes an induction heating channel. At the same time, the part of the copper tube 3-1 through which the wire 6 passes is covered with a ceramic ring to reduce the wear of the copper tube 3-1.

[0058] The power supply cable led out by the power supply device 9 is connected to the copper tube 3-1, and the heating power and heating time can be set on the power supply device 9. A control pedal is also provided on the power supply device 9, and the heating time can be flexibly controlled by manual operation through the pedal when necessary.

[0059] The drain port of the water cooling device 8 is connected to one end of the copper tube 3-1 through a water supply pipeline, and the return port is connected to the other end of the copper tube 3-1 through a return water pipeline. The water cooling device 8 is also provided with a water injection port, an air outlet, a water level gauge, etc. The water cooling device 8 can play a role in cooling in time after the induction heating head 3 is used.

[0060] Such as Figure 1 and 2 As shown in, the reverse wire feeding process is as follows:

[0061] Step 1: Use the wire feeding mechanism 4 to deliver the grain refiner wire 6 to the outlet end of the riser tube 2 of the metering furnace 1. The wire 6 is first preheated by passing through the induction heating head 3 and then enters the riser tube 2 in the reverse direction from the outlet end of the riser tube 2.

[0062] Step 2: After the wire 6 is immersed in the molten metal, it melts under the high temperature of the molten metal. At this time, the feeding speed of the wire 6 is reduced, and the addition amount of the wire 6 is controlled by controlling the DC motor 4-10. The melted grain refiner is located in the riser tube 2 and completes the preliminary mixing with the molten metal.

[0063] Step 3: When the melting amount meets the requirements, the DC motor 4-10 in the wire feeding mechanism 4 rotates reversely to withdraw the wire 6 from the riser tube 2. Since the melting and feeding time is short and the riser tube 2 is inclined, the grain refiner will not settle and agglomerate, nor will it diffuse from the inlet at the lower end of the riser tube 2 into the furnace body of the metering furnace 1.

[0064] Step 4: The metering furnace 1 discharges the molten metal from the riser tube 2. The melted grain refiner in the riser tube 2 leaves the metering furnace 1 completely with the molten metal flowing from bottom to top, and is fully mixed with the molten metal during the discharge process of the molten metal, and finally enters the mold.

[0065] The above process can be automatically controlled by devices such as PLC and industrial personal computer without manual intervention.

[0066] It should be noted that for those skilled in the art, obviously, the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. The scope of the present invention is defined by the claims rather than the above description.

Claims

1. A method for reverse wire feeding of a grain refiner for high pressure die casting, the method being based on a wire feeding system comprising a dosing furnace (1), the dosing furnace (1) being provided with a liquid riser (2), characterized in that: The wire feeding system further comprises a wire feeding mechanism (4), wherein the wire feeding mechanism (4) is used to feed the grain refiner wire (6) from the outlet end of the riser tube (2); the riser tube (2) is arranged obliquely, with the inlet at the bottom and the outlet at the top; The reverse wire feeding method includes the following steps: Step 1: Using a wire feeding mechanism (4), a grain refiner wire (6) is delivered to the outlet end of a liquid riser pipe (2) of a quantitative furnace (1); the wire (6) is first heated by an induction heating device and then enters the liquid riser pipe (2) in the reverse direction from the outlet end of the liquid riser pipe (2); Step 2: After the wire (6) is immersed in the molten metal, it melts under the high temperature of the molten metal, and the speed of delivering the wire (6) is reduced; the melted grain refiner is located in the riser tube (2); Step 3: When the melting amount meets the requirement, the wire feeding mechanism (4) moves in the reverse direction to draw the wire (6) out of the liquid riser (2); Step 4: The dosing furnace (1) discharges the molten metal from the riser tube (2). The grain refiner melted in the riser tube (2) leaves the dosing furnace (1) along with the molten metal and is fully mixed with the molten metal during the discharge process.

2. The grain refiner reverse wire feeding method for high pressure die casting according to claim 1, characterized in that: The wire feeding system also includes an induction heating device, which is used to heat the wire material (6) fed out by the wire feeding mechanism (4) and not yet entering the liquid riser (2).

3. The grain refiner reverse wire feeding method for high pressure die casting according to claim 2, characterized in that: The induction heating device comprises an induction heating head (3), a power supply device (9) and a water cooling device (8); The induction heating head (3) comprises a copper tube (3-1) fixedly placed relative to the quantitative furnace (1), the copper tube (3-1) being wound into a coil shape to form an induction heating channel; a power supply cable led out of the power supply device (9) is connected to the copper tube (3-1); The water outlet of the water cooling device (8) is connected to one end of the copper tube (3-1) via a water supply pipeline, and the water return port is connected to the other end of the copper tube (3-1) via a water return pipeline.

4. The grain refiner reverse wire feeding method for high pressure die casting according to claim 3, characterized in that: The power supply device (9) is provided with a control pedal.

5. The grain refiner reverse wire feeding method for high pressure die casting according to claim 1, characterized in that: The wire feeding mechanism (4) comprises a main body (4-1), and also comprises a driving device, a driving wheel (4-2), a driven wheel (4-3) and a clamping mechanism installed on the main body (4-1); The driving device is in transmission connection with the driving wheel (4-2), and the clamping mechanism is used to push the driven wheel (4-3) toward the driving wheel (4-2) to clamp the wire material (6).

6. The grain refiner reverse wire feeding method for high pressure die casting according to claim 5, characterized in that: The driving wheels (4-2) are in two groups and are mounted on the body (4-1) by means of a rotational connection; The driven wheels (4-3) are in two groups, corresponding one to one with the two groups of driving wheels (4-2); The clamping mechanism comprises a first rotating arm (4-4), a second rotating arm (4-9), a connecting rod (4-5), a rotating sleeve (4-6), a spring (4-7) and a threaded sleeve (4-8); The first rotating arm (4-4) and the second rotating arm (4-9) are both mounted on the body (4-1) by means of a rotating connection; the two driven wheels (4-3) are respectively mounted on one end of the first rotating arm (4-4) and one end of the second rotating arm (4-9); One end of the connecting rod (4-5) is rotatably connected to the other end of the first rotating arm (4-4), and the other end passes through the rotating sleeve (4-6) and the spring (4-7) in sequence and is threadably connected to the threaded sleeve (4-8); one end of the spring (4-7) is in contact with the rotating sleeve (4-6), and the other end is in contact with the threaded sleeve (4-8); The rotating sleeve (4-6) is rotatably connected to the other end of the second rotating arm (4-9).

7. The grain refiner reverse wire feeding method for high pressure die casting according to claim 1, characterized in that: The wire feeding system also includes a wire reel (7) for winding the wire material (6), and the wire material (6) drawn out of the wire reel (7) is fed into the wire feeding mechanism (4).

8. The grain refiner reverse wire feeding method for high pressure die casting according to claim 7, characterized in that: The wire reel (7) and the wire feeding mechanism (4) are mounted on a support seat (5), and the wire reel (7) and the support seat (5) are rotatably connected.

9. The grain refiner reverse wire feeding method for high pressure die casting according to claim 8, characterized in that: The support seat (5) is movable.

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