Device and method for eliminating air holes in sand mold casting

Abstract

The invention relates to the technical field of sand casting, in particular to a device and method for eliminating air holes in sand casting, comprising a mounting support, a bottom plate is arranged above the mounting support, a top plate is arranged above the bottom plate, and four ends of adjacent sides of the bottom plate and the top plate are fixedly connected with limiting frames; a round disc is fixedly connected to the center of the bottom of the bottom plate, and a spherical groove is formed in the bottom of the round disc; the mobility of molten metal in the cavity is improved through rotation of the mold, the molten metal can flow into a complex structure of the cavity, the cavity filling integrity is improved, it is guaranteed that gas in the molten metal has sufficient time to volatilize, and therefore generation of air holes is further reduced, and the product quality is improved. And as the pouring mold of the molten metal gradually returns in the inclined state, the molten metal is kept horizontal after pouring is completed, and the uniformity of mold filling of the cavity is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of sand casting, and particularly to a device and a method for eliminating air holes in sand casting. Background Art

[0002] Sand casting refers to a casting method for producing castings in a sand mold. Castings of steel, iron, and most non-ferrous alloys can be obtained by sand casting. Since the molding materials used in sand casting are inexpensive and easily available, and the mold manufacturing is simple, it can adapt to single-piece production, batch production, and mass production of castings. For a long time, it has been the basic process in casting production.

[0003] The patent document with the publication number CN112517857A discloses a casting method for eliminating air holes on the top surface of a blind hole oil passage, which includes the following steps: 1) manufacturing a blind hole oil passage sand core and other sand cores; 2) assembling, dipping, and drying the blind hole oil passage sand core; 3) molding; 4) setting cores; 5) closing the mold; 6) pouring; 7) cleaning; 8) detecting.

[0004] In the prior art during the sand casting process, an exhaust passage is usually opened on the mold to discharge the gas during the pouring of the molten metal, so as to prevent air holes from being generated on the casting. However, during the pouring process of the molten metal, the molten metal usually vertically pours into the mold along the pouring hole at the top of the mold. After the molten metal enters the mold, it will vertically impact the bottom of the cavity, resulting in splashing and turbulence of the molten metal, and it is easy to entrain gas when the molten metal generates splashing and turbulence, thus forming air holes after cooling. And during the pouring process, the fluidity of the molten metal is relatively low, so that it is difficult to discharge the gas after it enters the molten metal, thereby increasing the probability of air hole generation. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies existing in the prior art, and to propose a device and a method for eliminating air holes in sand casting.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is: a device for eliminating air holes in sand casting, including a mounting support, a bottom plate is arranged above the mounting support, a top plate is arranged above the bottom plate, four ends of adjacent sides of the bottom plate and the top plate are fixedly connected with limiting frames, and a moving limiting mechanism is connected between the bottom plate and the top plate;

[0007] A circular disc is fixedly connected to the center of the bottom of the bottom plate. A spherical groove is formed in the bottom of the circular disc. A rotating shaft is rotatably connected to the top of the mounting support. A spherical shell is fixedly connected to the top of the rotating shaft. The spherical shell is slidably connected inside the spherical groove. A circular through groove is formed in the top of the spherical shell. A circular rod is fixedly connected to the top surface inside the spherical groove. The bottom end of the circular rod extends into the spherical shell along the circular through groove and is fixedly connected with a spherical block. Six first arc grooves are formed in the circumferential direction on the surface of the spherical block. Six second arc grooves are formed in the circumferential direction on the inner wall of the spherical shell. Transmission balls are arranged between the corresponding first arc grooves and the second arc grooves. An arc-shaped collar is slidably sleeved on the surface of the spherical block. Six limiting grooves are formed in the circumferential direction on the surface of the arc-shaped collar. The limiting grooves are sleeved on the corresponding transmission balls respectively;

[0008] A driving rotation mechanism is connected to the rotating shaft, and a sliding inclination mechanism is connected to the circular disc. The bottom plate and the top plate are driven to incline along the axis of the spherical shell by the sliding inclination mechanism and are gradually adjusted to be horizontal during the pouring process.

[0009] Preferably, the sliding inclination mechanism includes an annular round rod. The annular round rod is fixedly connected to the side surface of the circular disc and is coaxially arranged with the circular disc. Two strip-shaped grooves are formed in the mounting support. A rectangular ring is slidably connected inside each of the two strip-shaped grooves. A vertical strip is slidably connected inside each of the rectangular rings. The annular round rod is located between the tops of the two vertical strips. Two limiting rollers are rotatably connected to the tops of the two vertical strips respectively. The annular round rod is slidably limited between two adjacent limiting rollers. A mounting plate is fixedly connected to the bottom of the mounting support. A movable rod is arranged on one side of the mounting plate. A swinging air cylinder is fixedly installed on the mounting plate. The piston rod of the swinging air cylinder penetrates through the mounting plate and is fixedly connected to the center of the movable rod. The bottom ends of the two vertical strips are respectively rotatably connected to the two ends of the movable rod.

[0010] Preferably, the driving rotation mechanism includes a first gear and a motor. The first gear is fixedly connected to the rotating shaft. The motor is fixedly installed at the bottom of the mounting support. The output shaft of the motor penetrates through the mounting support and extends above the mounting support and is fixedly connected to a second gear. The second gear meshes with the first gear.

[0011] Preferably, the movable limiting mechanism includes a first circular frame and a second circular frame. The first circular frame and the second circular frame are respectively fixedly connected to the sides of the bottom plate and the top plate. A plurality of limiting pins are fixedly connected to the top of the first circular frame, and the limiting pins are all slidably inserted on the second circular frame. Two hydraulic cylinders are fixedly installed on the top of the first circular frame, and the piston shafts of the hydraulic cylinders are fixedly connected to the bottom of the second circular frame.

[0012] Preferably, a circular groove is formed at the center of the top plate. An annular shell is fixedly connected inside the circular groove. The bottom of the annular shell is flush with the bottom of the top plate. A plurality of insertion pipes are fixedly communicated with the bottom of the annular shell. A vacuum pump is fixedly installed on the top of the second circular frame, and an air extraction pipe is fixedly communicated between the air inlet pipe of the vacuum pump and the annular shell.

[0013] Preferably, a pressure sensor is fixedly installed on the top of the air extraction pipe.

[0014] Preferably, two U-shaped rods are arranged above the top plate. A liquid injection hopper is fixedly installed between the two U-shaped rods. Sliders are slidably inserted at both ends of the U-shaped rods, and the sliders are fixedly connected to the mounting brackets. U-shaped sliding seats are slidably connected to both sides of the second circular frame. A fixed strip is fixedly connected to the U-shaped sliding seat. Outer convex arc-shaped blocks are fixedly connected to one side of the two fixed strips away from each other. Inner concave arc-shaped blocks are arranged on one side of the two outer convex arc-shaped blocks away from each other. The inner concave arc-shaped block and the corresponding outer convex arc-shaped block are arc-shaped and fitted to each other. Fixed blocks are fixedly connected to both sides of the inner concave arc-shaped block, and the fixed blocks are fixedly connected to the corresponding U-shaped rods.

[0015] Preferably, the liquid injection hopper includes an annular section and a collection section. The annular section is fixedly connected between the two U-shaped rods. The collection section is rotatably connected to the bottom of the annular section. A liquid injection pipe is arranged on the side of the collection section. The liquid injection pipe includes a U-shaped section and a vertical section. The vertical section is located at the bottom of the U-shaped section. One end of the U-shaped section is slidably inserted into the side of the collection section, and after one end of the U-shaped section extends into the collection section, it is fixedly connected with an arc-shaped baffle.

[0016] Preferably, annular grooves are formed at both the upper and lower ends of the second circular frame. Rolling grooves are formed on both the upper and lower sides inside the U-shaped sliding seat, and contact balls are rotatably connected between the rolling grooves and the corresponding annular grooves.

[0017] A method for eliminating air holes in a sand casting mold, the method comprising the following steps:

[0018] Step 1: Place the lower mold for sand casting on the top of the bottom plate, and horizontally limit the lower mold through the limiting frame on the bottom plate. Then place the upper mold on the top of the lower mold for mold clamping. Next, under the action of the moving limiting mechanism, the top plate moves vertically downward and contacts the top of the upper mold, and horizontally limit the upper mold through the limiting frame on the top plate;

[0019] Step 2: Under the action of the sliding and tilting mechanism, the circular plate tilts to one side, thereby driving the bottom plate and the top plate to tilt synchronously. During the tilting process of the circular plate, through the sliding connection between the spherical shell and the spherical groove, the circular plate slides along the axis of the spherical shell, and drives the circular rod to move synchronously. The spherical block at the bottom of the circular rod tilts synchronously along the axis inside the spherical shell, and drives the arc-shaped collar to slide in cooperation. The position of the transmission ball is limited through the limiting groove on the arc-shaped collar to ensure that the transmission ball moves in cooperation between the corresponding first arc groove and the second arc groove;

[0020] Step 3: Under the action of the driving and rotating mechanism, the rotating shaft rotates slowly. During the rotation of the rotating shaft, the spherical shell rotates synchronously inside the spherical groove. Through the limiting effect of the second arc groove inside the spherical shell on the transmission ball, the transmission ball moves in cooperation inside the corresponding second arc groove. And through the limiting effect of the first arc groove on the transmission ball, the spherical block drives the circular rod to rotate axially in the tilted state, thereby driving the top plate and the bottom plate to rotate in the tilted state.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. By tilting the top plate and the bottom plate, the mold tilts synchronously. Thus, during the process of pouring molten metal, an inclination angle is formed between the vertically downward flowing molten metal and the bottom of the cavity, enabling the molten metal to flow smoothly into the cavity interior, reducing the splashing and turbulence of the molten metal, thereby preventing gas from being involved during the pouring process and forming pores after cooling. And through the rotation of the rotating shaft, the mold rotates slowly in one direction in the tilted state. By the rotation of the mold, the fluidity of the molten metal inside the cavity is increased, enabling the molten metal to flow into the complex structure of the cavity, improving the integrity of the cavity filling. And after increasing the fluidity, premature cooling of the molten metal is avoided, ensuring that the gas in the molten metal has sufficient time to volatilize, thereby further reducing the generation of pores. As the mold gradually returns to the upright state during the pouring of the molten metal, the molten metal remains horizontal when the pouring is completed, ensuring the uniformity of the cavity filling.

[0023] 2. As the movable rod rotates, the two vertical bars approach each other, causing the rectangular ring to move in cooperation along the sliding connection of the strip groove. When the two vertical bars rise and fall respectively, the annular round rod is synchronously tilted by the limiting action of the limiting roller, driving the circular disc to tilt. During the rotation of the circular disc, the annular round rod rotates synchronously, and the limiting roller rotates through the contact between the limiting roller and the annular round rod, reducing the contact friction at the limiting position.

[0024] 3. When the top plate inside the second circular frame contacts the top of the mold, the arc surfaces of the concave arc surface block and the convex arc surface block are coaxial with the spherical shell. Thus, when the second circular frame and the top plate tilt to one side, the convex arc surface block slides in cooperation along the arc surface of the concave arc surface block, causing the fixed strip to drive the U-shaped sliding seat to flip and tilt synchronously, ensuring the sliding connection between the U-shaped sliding seat and the second circular frame, and keeping the liquid injection hopper always vertical. Therefore, after the molten metal is introduced into the liquid injection hopper, the injection angle of the liquid injection hopper remains unchanged, reducing the splashing and turbulence phenomena during pouring. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the first structural schematic diagram of the present invention;

[0026] Figure 2 of the present invention Figure 1 is an enlarged schematic diagram of the structure at A in;

[0027] Figure 3 of the present invention Figure 1 is an enlarged schematic diagram of the structure at B in;

[0028] Figure 4 is the second structural schematic diagram of the present invention;

[0029] Figure 5 of the present invention Figure 4 is an enlarged schematic diagram of the structure at C in;

[0030] Figure 6 of the present invention Figure 4 is an enlarged schematic diagram of the structure at D in;

[0031] Figure 7 is the sectional structural schematic diagram of the present invention;

[0032] Figure 8 of the present invention Figure 7 is an enlarged schematic diagram of the structure at E in;

[0033] Figure 9 of the present invention Figure 7 is an enlarged schematic diagram of the structure at F in;

[0034] Figure 10 of the present invention Figure 7Schematic enlarged view of the structure at position G in

[0035] Figure 11 Schematic cross-sectional view of the mating structure of the liquid injection hopper and the liquid injection pipe of the present invention.

[0036] In the figure: 1, mounting support; 2, bottom plate; 3, top plate; 4, limiting frame; 5, circular disk; 6, spherical groove; 7, rotating shaft; 8, spherical shell; 9, circular through groove; 10, circular rod; 11, spherical block; 12, first arc groove; 13, second arc groove; 14, transmission ball; 15, arc collar; 16, limiting groove; 17, annular round rod; 18, strip groove; 19, rectangular ring; 20, vertical strip; 21, limiting roller; 22, mounting plate; 23, movable rod; 24, swing cylinder; 25, first gear; 26, motor; 27, second gear; 28, first circular frame; 29, second circular frame; 30, limiting pin; 31, hydraulic cylinder; 32, circular groove; 33, annular shell; 34, insertion pipe; 35, vacuum pump; 36, air extraction pipe; 37, pressure sensor; 38, U-shaped rod; 39, liquid injection hopper; 3901, annular section; 3902, collection section; 40, slider; 41, U-shaped sliding seat; 42, fixed strip; 43, convex arc surface block; 44, concave arc surface block; 45, fixed block; 46, liquid injection pipe; 4601, U-shaped section; 4602, vertical section; 47, arc baffle; 48, annular groove; 49, rolling groove; 50, contact ball. Detailed implementation manners

[0037] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0038] As Figures 1 to 11 shown, a device for eliminating air holes in sand casting includes a mounting support 1. A bottom plate 2 is arranged above the mounting support 1, and a top plate 3 is arranged above the bottom plate 2. Four ends of the adjacent sides of the bottom plate 2 and the top plate 3 are fixedly connected with limiting frames 4, and a moving limiting mechanism is connected between the bottom plate 2 and the top plate 3;

[0039] A circular disc 5 is fixedly connected to the center of the bottom of the bottom plate 2. A spherical groove 6 is provided at the bottom of the circular disc 5. A rotating shaft 7 is rotatably connected to the top of the mounting support 1. A spherical shell 8 is fixedly connected to the top of the rotating shaft 7. The spherical shell 8 is slidably connected inside the spherical groove 6. A circular through groove 9 is provided at the top of the spherical shell 8. A circular rod 10 is fixedly connected to the top surface inside the spherical groove 6. The bottom end of the circular rod 10 extends into the spherical shell 8 along the circular through groove 9 and is fixedly connected with a spherical block 11. Six first arc grooves 12 are circumferentially provided on the surface of the spherical block 11. Six second arc grooves 13 are circumferentially provided on the inner wall of the spherical shell 8. Transmission balls 14 are arranged between the corresponding first arc grooves 12 and second arc grooves 13. An arc-shaped collar 15 is slidably sleeved on the surface of the spherical block 11. Six limiting grooves 16 are circumferentially provided on the surface of the arc-shaped collar 15. The limiting grooves 16 are all sleeved on the corresponding transmission balls 14;

[0040] A driving rotation mechanism is connected to the rotating shaft 7, and a sliding inclination mechanism is connected to the circular disk 5. The bottom plate 2 and the top plate 3 are driven by the sliding inclination mechanism to incline along the axis of the spherical shell 8 and are gradually adjusted to be horizontal during the pouring process. During operation, in the prior art during sand casting, exhaust channels are usually opened on the mold to discharge the gas during the pouring of the molten metal, so as to prevent the formation of pores on the casting. However, during the pouring of the molten metal, the molten metal usually vertically pours into the mold along the pouring hole at the top of the mold. After the molten metal enters the mold, it will vertically impact the bottom of the cavity, resulting in the splashing and turbulence of the molten metal. When the molten metal splashes and turbulences, it is easy to entrain gas, resulting in the formation of pores after cooling. Moreover, during the pouring process, the fluidity of the molten metal is low, so that it is difficult for the gas to be discharged after pouring into the molten metal, increasing the probability of pore formation;This technical solution can solve the above problems, and the specific working method is as follows: Place the lower mold for sand casting on the top of the bottom plate 2, and horizontally limit the lower mold through the limiting frame 4 on the bottom plate 2. Then place the upper mold on the top of the lower mold for mold closing. Then, under the action of the moving limiting mechanism, the top plate 3 moves vertically downward and contacts the top of the upper mold, and horizontally limit the upper mold through the limiting frame 4 on the top plate 3. Under the action of the sliding inclination mechanism, the circular disc 5 inclines to one side, thereby driving the bottom plate 2 and the top plate 3 to incline synchronously. During the inclination of the circular disc 5, through the sliding connection between the spherical shell 8 and the spherical groove 6, the circular disc 5 slides along the axis of the spherical shell 8, and drives the circular rod 10 to move synchronously. The spherical block 11 at the bottom of the circular rod 10 inclines synchronously along the axis inside the spherical shell 8, and drives the arc-shaped collar 15 to slide in cooperation. The position of the transmission ball 14 is limited by the limiting groove 16 on the arc-shaped collar 15 to ensure that the transmission ball 14 moves in cooperation between the corresponding first arc groove 12 and the second arc groove 13. Then, under the action of the driving rotation mechanism, the rotating shaft 7 rotates slowly. During the rotation of the rotating shaft 7, it drives the spherical shell 8 to rotate synchronously inside the spherical groove 6, and through the limiting effect of the second arc groove 13 inside the spherical shell 8 on the transmission ball 14, the transmission ball 14 moves in cooperation inside the corresponding second arc groove 13, and through the limiting effect of the first arc groove 12 on the transmission ball 14, the spherical block 11 drives the circular rod 10 to rotate axially in the inclined state, thereby driving the top plate 3 and the bottom plate 2 to rotate in the inclined state, and making the mold after mold closing rotate in an inclined state synchronously. Finally, pour the molten metal along the pouring port on the top of the upper mold, so that the molten metal enters the cavity inside between the upper mold and the lower mold, and during the pouring process, under the action of the sliding inclination mechanism, the top plate 3 and the bottom plate 2 gradually return to the vertical state during the rotation until they return to the horizontal state again. Through the inclination of the top plate 3 and the bottom plate 2, the mold inclines synchronously, so that during the pouring of the molten metal, an inclination angle is formed between the vertically downward flowing molten metal and the bottom of the cavity, enabling the molten metal to flow smoothly into the cavity, reducing the splashing and turbulence of the molten metal, thereby preventing gas from being involved during the pouring process and forming pores after cooling. And through the rotation of the rotating shaft 7, the mold rotates slowly in one direction in the inclined state. Through the rotation of the mold, the fluidity of the molten metal inside the cavity is increased, enabling the molten metal to flow into the complex structure of the cavity, improving the integrity of the cavity filling, and avoiding premature cooling of the molten metal after increasing the fluidity, ensuring that the gas in the molten metal has sufficient time to volatilize, thereby further reducing the generation of pores. As the molten metal is poured, the mold gradually returns to the vertical state in the inclined state, so that the molten metal remains horizontal when the pouring is completed, ensuring the uniformity of the cavity filling.;

[0041] As a further embodiment of the present invention, the sliding and tilting mechanism includes an annular round rod 17, which is fixedly connected to the side surface of the circular disk 5 and arranged coaxially with the circular disk 5. Two strip-shaped grooves 18 are formed in the mounting support 1 (as Figure 9 shown). A rectangular ring 19 is slidably connected to the inside of each of the two strip-shaped grooves 18, and a vertical bar 20 is slidably connected to the inside of the rectangular ring 19. The annular round rod 17 is located between the tops of the two vertical bars 20. Two limiting rollers 21 are rotatably connected to the tops of the two vertical bars 20. The annular round rod 17 is slidably limited between two adjacent limiting rollers 21. A mounting plate 22 is fixedly connected to the bottom of the mounting support 1. A movable rod 23 is arranged on one side of the mounting plate 22. A swing cylinder 24 is fixedly mounted on the mounting plate 22. The piston rod of the swing cylinder 24 penetrates through the mounting plate 22 and is fixedly connected to the center of the movable rod 23. The bottoms of the two vertical bars 20 are respectively rotatably connected to the two ends of the movable rod 23. During operation, the piston rod of the swing cylinder 24 rotates to drive the movable rod 23 to flip along the center, and through the rotational connection between the movable rod 23 and the two vertical bars 20, the two vertical bars 20 move in cooperation along the rotational connection points and rise and fall respectively. Through the sliding connection between the rectangular ring 19 and the vertical bar 20, the vertical bar 20 always remains vertical, and as the movable rod 23 rotates, the two vertical bars 20 approach each other, so that the rectangular ring 19 moves in cooperation along the sliding connection of the strip-shaped groove 18. When the two vertical bars 20 rise and fall respectively, the annular round rod 17 is synchronously tilted through the limiting action of the limiting rollers 21, thereby driving the circular disk 5 to tilt. And during the rotation of the circular disk 5, the annular round rod 17 rotates synchronously, and the limiting rollers 21 rotate through the contact between the limiting rollers 21 and the annular round rod 17, reducing the contact friction at the limiting position.

[0042] As a further embodiment of the present invention, the driving and rotating mechanism includes a first gear 25 and a motor 26. The first gear 25 is fixedly connected to the rotating shaft 7. The motor 26 is fixedly mounted on the bottom of the mounting support 1. The output shaft of the motor 26 penetrates through the mounting support 1 and extends above the mounting support 1 and is fixedly connected to a second gear 27. The second gear 27 and the first gear 25 are meshed with each other. During operation, the output shaft of the motor 26 rotates to drive the second gear 27 to rotate synchronously, and through the meshing action between the second gear 27 and the first gear 25, the first gear 25 rotates in cooperation, thereby driving the rotating shaft 7 to rotate unidirectionally along the rotational connection point.

[0043] As a further embodiment of the present invention, the movable limiting mechanism includes a first circular frame 28 and a second circular frame 29. The first circular frame 28 and the second circular frame 29 are respectively fixedly connected to the sides of the bottom plate 2 and the top plate 3. A plurality of limiting pins 30 are fixedly connected to the top of the first circular frame 28. The limiting pins 30 are all slidably inserted into the second circular frame 29. Two hydraulic cylinders 31 are fixedly installed on the top of the first circular frame 28. The piston shafts of the hydraulic cylinders 31 are fixedly connected to the bottom of the second circular frame 29. During operation, the piston shafts of the two hydraulic cylinders 31 move downward, causing the second circular frame 29 to move vertically downward along the sliding insertion part of the limiting pins 30, so that the top plate 3 moves downward synchronously, and the mold after mold closing is clamped between the top plate 3 and the bottom plate 2, and the side of the mold is limited by the limiting frame 4.

[0044] As a further embodiment of the present invention, a circular groove 32 is opened at the center of the top plate 3. An annular shell 33 is fixedly connected inside the circular groove 32. The bottom of the annular shell 33 is flush with the bottom of the top plate 3. A plurality of insertion pipes 34 are fixedly communicated with the bottom of the annular shell 33. A vacuum pump 35 is fixedly installed on the top of the second circular frame 29. An air extraction pipe 36 is fixedly communicated between the intake pipe of the vacuum pump 35 and the annular shell 33. During operation, when the top plate 3 moves downward and clamps the mold between the top plate 3 and the bottom plate 2, the insertion pipes 34 at the bottom of the annular shell 33 are correspondingly inserted into the exhaust ports opened at the top of the mold during the movement, and during the pouring of the molten metal, the gas inside the mold cavity is pumped into the annular shell 33 along the insertion pipes 34 through the suction action of the vacuum pump 35, and is pumped into the air extraction pipe 36 along the communication part between the annular shell 33 and the air extraction pipe 36, and finally enters the vacuum pump 35 for discharge, so as to actively discharge the gas inside the mold cavity and improve the exhaust efficiency inside the cavity.

[0045] As a further embodiment of the present invention, a pressure sensor 37 is fixedly installed on the top of the air extraction pipe 36. During operation, the air pressure inside the air extraction pipe 36 is monitored in real time by the pressure sensor 37, and the pumping power of the vacuum pump 35 is controlled by the controller connected to the pressure sensor 37 to prevent excessive pumping from causing the molten metal to penetrate into the insertion pipes 34.

[0046] As a further embodiment of the present invention, two U-shaped rods 38 are arranged above the top plate 3, and a liquid injection hopper 39 is fixedly installed between the two U-shaped rods 38. Sliders 40 are slidably inserted at both ends of the U-shaped rods 38, and the sliders 40 are fixedly connected to the mounting support 1. U-shaped sliding seats 41 are slidably connected to both sides of the second circular frame 29. A fixing strip 42 is fixedly connected to the U-shaped sliding seat 41. Outer convex arc surface blocks 43 are fixedly connected to one side of the two fixing strips 42 away from each other. Inner concave arc surface blocks 44 are arranged on one side of the two outer convex arc surface blocks 43 away from each other. The inner concave arc surface block 44 and the corresponding outer convex arc surface block 43 are arc-surface fitted. Fixed blocks 45 are fixedly connected to both sides of the inner concave arc surface block 44, and the fixed blocks 45 are fixedly connected to the corresponding U-shaped rods 38. During operation, through the sliding limit of the U-shaped sliding seat 41 and the second circular frame 29, when the second circular frame 29 drives the top plate 3 to move downward and clamp the mold, the U-shaped sliding seat 41 moves downward synchronously with the second circular frame 29, and drives the outer convex arc surface block 43 to move downward synchronously. Through the arc-surface limiting action of the outer convex arc surface block 43 and the inner concave arc surface block 44, the inner concave arc surface block 44 moves downward synchronously, and drives the fixed block 45 and the U-shaped rod 38 to move downward synchronously. The U-shaped rod 38 cooperates with the sliding insertion part of the slider 40 to slide. When the top plate 3 inside the second circular frame 29 contacts the top of the mold, the arcs of the inner concave arc surface block 44 and the outer convex arc surface block 43 are both coaxially arranged with the spherical shell 8. Thus, when the second circular frame 29 and the top plate 3 tilt to one side, the outer convex arc surface block 43 slides along the arc surface of the inner concave arc surface block 44, so that the fixing strip 42 drives the U-shaped sliding seat 41 to tilt synchronously, ensuring the sliding connection between the U-shaped sliding seat 41 and the second circular frame 29, and keeping the liquid injection hopper 39 always perpendicular to the top of the mounting support 1. Therefore, after the molten metal is introduced into the liquid injection hopper 39, the liquid injection angle of the liquid injection hopper 39 remains unchanged, reducing the splashing and turbulence phenomena during pouring.

[0047] As a further embodiment of the present invention, the liquid injection hopper 39 includes an annular section 3901 and a collection section 3902. The annular section 3901 is fixedly connected between the two U-shaped rods 38. The collection section 3902 is rotatably connected to the bottom of the annular section 3901. A liquid injection pipe 46 is arranged on the side surface of the collection section 3902 (as Figure 11As shown in the figure, the liquid injection pipe 46 includes a U-shaped section 4601 and a vertical section 4602. The vertical section 4602 is located at the bottom of the U-shaped section 4601. One end of the U-shaped section 4601 is slidably inserted into the side of the collection section 3902. After one end of the U-shaped section 4601 extends into the collection section 3902, an arc-shaped baffle 47 is fixedly connected thereto. During operation, when the top plate 3 moves to the top of the mold, the bottom end of the vertical section 4602 of the liquid injection pipe 46 is located in the pouring hole at the top of the mold. The diameter of the vertical section 4602 of the liquid injection pipe 46 is smaller than the inner diameter of the pouring hole. Therefore, when the bottom plate 2 and the top plate 3 drive the mold to tilt, the pouring hole of the mold tilts synchronously and deviates from the center point. Since the diameter of the vertical section 4602 is smaller than the inner diameter of the pouring hole, when the pouring hole tilts and deviates, the pouring hole has a certain angular clearance space. And when the pouring hole tilts and deviates from the center point, the U-shaped section 4601 of the liquid injection pipe 46 moves in cooperation along the sliding insertion part of the collection section 3902, so as to ensure that the bottom end of the vertical section 4602 of the liquid injection pipe 46 is always located in the pouring hole. When the mold rotates obliquely, after the pouring hole deviates from the center point, it rotates around the original center point, so that the liquid injection pipe 46 drives the collection section 3902 to rotate in cooperation synchronously, ensuring that the position of the liquid injection hopper 39 remains unchanged after the pouring hole tilts and deviates from the center point, thus ensuring the stability during the pouring process of the molten metal. And after the molten metal enters the liquid injection hopper 39, it enters the U-shaped section 4601 along one end of the U-shaped section 4601 located inside the collection section 3902, and enters the vertical section 4602 along the U-shaped section 4601, so as to vertically pour into the pouring hole.

[0048] As a further embodiment of the present invention, annular grooves 48 are opened at both the upper and lower ends of the second circular frame 29. Rolling grooves 49 are opened on both the upper and lower sides inside the U-shaped sliding seat 41. Contact balls 50 are rotatably connected between the rolling grooves 49 and the corresponding annular grooves 48. During operation, when the second circular frame 29 rotates along the sliding connection part of the U-shaped sliding seat 41, the contact balls 50 are limited by the rolling grooves 49 and the annular grooves 48, and the contact balls 50 roll in cooperation through contact friction when the second circular frame 29 rotates, thereby reducing the contact wear between the U-shaped sliding seat 41 and the second circular frame 29.

[0049] An elimination method for an apparatus for eliminating air holes in sand casting, the method comprising the following steps:

[0050] Step 1: Place the lower mold for sand casting on the top of the bottom plate 2, and horizontally limit the lower mold through the limiting frame 4 on the bottom plate 2. Then place the upper mold on the top of the lower mold for mold closing. Then, under the action of the moving limiting mechanism, the top plate 3 moves vertically downward to contact the top of the upper mold, and the upper mold is horizontally limited through the limiting frame 4 on the top plate 3.

[0051] Step 2: The circular disk 5 is tilted to one side by the sliding and tilting mechanism, thereby driving the bottom plate 2 and the top plate 3 to tilt synchronously. During the tilting process of the circular disk 5, through the sliding connection between the spherical shell 8 and the spherical groove 6, the circular disk 5 slides along the axis of the spherical shell 8, and drives the circular rod 10 to move synchronously. The spherical block 11 at the bottom of the circular rod 10 tilts synchronously along the axis inside the spherical shell 8, and drives the arc-shaped collar 15 to slide in cooperation. The position of the transmission ball 14 is limited by the limiting groove 16 on the arc-shaped collar 15 to ensure that the transmission ball 14 moves in cooperation between the corresponding first arc groove 12 and the second arc groove 13;

[0052] Step 3: The rotating shaft 7 is slowly rotated by the driving and rotating mechanism. During the rotation of the rotating shaft 7, the spherical shell 8 is driven to rotate synchronously inside the spherical groove 6. Through the limiting effect of the second arc groove 13 inside the spherical shell 8 on the transmission ball 14, the transmission ball 14 moves in cooperation inside the corresponding second arc groove 13. And through the limiting effect of the first arc groove 12 on the transmission ball 14, the spherical block 11 drives the circular rod 10 to rotate axially in the tilted state, thereby driving the top plate 3 and the bottom plate 2 to rotate in the tilted state.

[0053] The working principle of the present invention:

[0054] Place the lower mold for sand casting on the top of the bottom plate 2, and horizontally limit the lower mold through the limiting frame 4 on the bottom plate 2. Then place the upper mold on the top of the lower mold for mold clamping. Then, under the action of the moving limiting mechanism, the top plate 3 moves vertically downward and contacts the top of the upper mold, and horizontally limit the upper mold through the limiting frame 4 on the top plate 3. Under the action of the sliding inclination mechanism, the circular disk 5 inclines to one side, thereby driving the bottom plate 2 and the top plate 3 to incline synchronously. During the inclination of the circular disk 5, through the sliding connection between the spherical shell 8 and the spherical groove 6, the circular disk 5 slides along the axis of the spherical shell 8, and drives the circular rod 10 to move synchronously. The spherical block 11 at the bottom of the circular rod 10 inclines synchronously along the axis inside the spherical shell 8, and drives the arc-shaped collar 15 to cooperate and slide. Limit the position of the transmission ball 14 through the limiting groove 16 on the arc-shaped collar 15 to ensure that the transmission ball 14 moves in cooperation between the corresponding first arc groove 12 and the second arc groove 13. Then, under the action of the driving rotation mechanism, the rotating shaft 7 rotates slowly. During the rotation of the rotating shaft 7, it drives the spherical shell 8 to rotate synchronously inside the spherical groove 6, and through the limiting effect of the second arc groove 13 inside the spherical shell 8 on the transmission ball 14, the transmission ball 14 moves in cooperation inside the corresponding second arc groove 13, and through the limiting effect of the first arc groove 12 on the transmission ball 14, the spherical block 11 drives the circular rod 10 to rotate axially in the inclined state, thereby driving the top plate 3 and the bottom plate 2 to rotate in the inclined state, and making the mold after mold clamping rotate inclined synchronously. Finally, pour the molten metal along the pouring gate on the top of the upper mold, so that the molten metal enters the cavity inside between the upper mold and the lower mold, and during the pouring process, through the action of the sliding inclination mechanism, the top plate 3 and the bottom plate 2 gradually return to the vertical position during the rotation until they return to the horizontal state again. Through the inclination of the top plate 3 and the bottom plate 2, the mold inclines synchronously, so that during the pouring of the molten metal, an inclination angle is formed between the vertically downward flowing molten metal and the bottom of the cavity, enabling the molten metal to flow smoothly into the cavity interior, reducing the splashing and turbulence of the molten metal, thereby preventing gas from being involved during the pouring process and forming pores after cooling. And through the rotation of the rotating shaft 7, the mold rotates slowly in one direction in the inclined state. Through the rotation of the mold, the fluidity of the molten metal inside the cavity is increased, enabling the molten metal to flow into the complex structure of the cavity, improving the integrity of the cavity filling, and avoiding premature cooling of the molten metal after increasing the fluidity, ensuring that the gas in the molten metal has sufficient time to volatilize, thereby further reducing the generation of pores. As the molten metal is poured, the mold gradually returns to the vertical position in the inclined state, making the molten metal horizontal when the pouring is completed, ensuring the uniformity of the cavity filling.

[0055] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, various changes and improvements will occur to the present invention, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for eliminating pores in sand casting, comprising a mounting support, characterized in that: A bottom plate is arranged above the mounting support, a top plate is arranged above the bottom plate, four ends of the bottom plate and the top plate on one side adjacent to each other are fixedly connected to a limiting frame, and a movable limiting mechanism is connected between the bottom plate and the top plate; A circular disk is fixedly connected at the bottom center of the bottom plate, a spherical groove is provided at the bottom of the circular disk, a rotating shaft is rotatably connected to the top of the mounting support, a spherical shell is fixedly connected to the top of the rotating shaft, the spherical shell is slidably connected to the inside of the spherical groove, a circular through groove is provided at the top of the spherical shell, a circular rod is fixedly connected to the top surface of the inside of the spherical groove, the bottom end of the circular rod extends along the circular through groove to the inside of the spherical shell and is fixedly connected to a spherical block, six first arc grooves are provided on the surface of the spherical block along the circumferential direction, six second arc grooves are provided on the inner wall of the spherical shell along the circumferential direction, transmission balls are arranged between the corresponding first arc grooves and the second arc grooves, an arc ring is slidingly sleeved on the surface of the spherical block, six limiting grooves are provided on the surface of the arc ring along the circumferential direction, and the limiting grooves are all sleeved on the corresponding transmission balls; The rotating shaft is connected with a driving rotating mechanism, and the circular disk is connected with a sliding tilting mechanism, which drives the bottom plate and the top plate to tilt along the axis of the spherical shell and gradually adjusts them to be horizontal during the pouring process.

2. The device for eliminating pores in sand casting according to claim 1, characterized in that: The sliding and tilting mechanism includes an annular round rod, which is fixedly connected to the side of the circular disk and coaxially arranged with the circular disk. Two strip grooves are provided on the mounting support. Rectangular rings are slidably connected to the inside of the two strip grooves. Vertical bars are slidably connected to the inside of the rectangular rings. The annular round rod is located between the top ends of the two vertical bars. The top ends of the two vertical bars are rotatably connected to two limiting rollers. The annular round rod is slidably limited between two adjacent limiting rollers. A mounting plate is fixedly connected to the bottom of the mounting support. A movable rod is arranged on one side of the mounting plate. A swing cylinder is fixedly installed on the mounting plate. The piston shaft of the swing cylinder passes through the mounting plate and is fixedly connected to the center of the movable rod. The bottom ends of the two vertical bars are rotatably connected to the two ends of the movable rod respectively.

3. The device for eliminating pores in sand casting according to claim 1, characterized in that: The driving rotation mechanism includes a first gear and a motor. The first gear is fixedly connected to the rotating shaft. The motor is fixedly installed at the bottom of the mounting support. The output shaft of the motor passes through the mounting support and extends to the top of the mounting support and is fixedly connected to the second gear. The second gear and the first gear are meshed with each other.

4. The device for eliminating pores in sand casting according to claim 1, characterized in that: The movable limiting mechanism includes a first circular frame and a second circular frame. The first circular frame and the second circular frame are respectively fixedly connected to the sides of the bottom plate and the top plate. The top of the first circular frame is fixedly connected with a plurality of limiting pins. The limiting pins are slidably inserted on the second circular frame. Two hydraulic cylinders are fixedly installed on the top of the first circular frame. The piston shafts of the hydraulic cylinders are fixedly connected to the bottom of the second circular frame.

5. The device for eliminating pores in sand casting according to claim 4, characterized in that: A circular groove is provided at the center of the top plate, an annular shell is fixedly connected to the inside of the circular groove, the bottom of the annular shell is flush with the bottom of the top plate, a plurality of plug-in tubes are fixedly connected to the bottom of the annular shell, a vacuum pump is fixedly installed on the top of the second circular frame, and an exhaust pipe is fixedly connected between the air inlet pipe of the vacuum pump and the annular shell.

6. The device for eliminating pores in sand casting according to claim 5, characterized in that: A pressure sensor is fixedly installed on the top of the exhaust pipe.

7. The device for eliminating pores in sand casting according to claim 4, characterized in that: Two U-shaped rods are arranged above the top plate, and a liquid injection bucket is fixedly installed between the two U-shaped rods, and sliders are slidably inserted at both ends of the U-shaped rod, and the sliders are fixedly connected to the mounting support, and U-shaped slide seats are slidably connected on both sides of the second circular frame, and a fixing bar is fixedly connected to the U-shaped slide seat, and a convex arc block is fixedly connected on the side where the two fixing bars are away from each other, and a concave arc block is arranged on the side where the two convex arc blocks are away from each other, and the arc surfaces of the concave arc block and the corresponding convex arc block are fitted together, and fixed blocks are fixedly connected on both sides of the concave arc block, and the fixed blocks are fixedly connected to the corresponding U-shaped rods.

8. The device for eliminating pores in sand casting according to claim 7, characterized in that: The liquid injection hopper includes an annular section and a collecting section. The annular section is fixedly connected between two U-shaped rods. The collecting section is rotatably connected to the bottom of the annular section. An injection pipe is arranged on the side of the collecting section. The injection pipe includes a U-shaped section and a vertical section. The vertical section is located at the bottom of the U-shaped section. One end of the U-shaped section is slidably inserted into the side of the collecting section. One end of the U-shaped section extends to the inside of the collecting section and is fixedly connected to an arc-shaped baffle.

9. The device for eliminating pores in sand casting according to claim 7, characterized in that: Annular grooves are provided at both upper and lower ends of the second circular frame, rolling grooves are provided at both upper and lower sides of the U-shaped sliding seat, and contact balls are rollingly connected between the rolling grooves and the corresponding annular grooves.

10. A method for eliminating pores in a sand casting device, applicable to the device for eliminating pores in a sand casting device according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: Step 1: Place the lower mold for sand casting on the top of the bottom plate, and limit the lower mold horizontally through the limit frame on the bottom plate, then place the upper mold on the top of the lower mold for mold closing, and then move the top plate vertically downward and contact with the top of the upper mold through the action of the mobile limit mechanism, and limit the upper mold horizontally through the limit frame on the top plate; Step 2: The circular plate is tilted to one side by the action of the sliding tilting mechanism, thereby driving the bottom plate and the top plate to tilt synchronously. During the tilting process, the circular plate slides along the axis of the spherical shell through the sliding connection between the spherical shell and the spherical groove, and drives the circular rod to move synchronously. The spherical block at the bottom of the circular rod is tilted synchronously along the axis inside the spherical shell, and drives the arc-shaped collar to slide in coordination. The position of the transmission ball is limited by the limiting groove on the arc-shaped collar, ensuring that the transmission ball moves in coordination between the corresponding first arc groove and the second arc groove. Step three, the rotating shaft is slowly rotated by driving the rotating mechanism, and the rotating shaft drives the spherical shell to rotate synchronously inside the spherical groove during the rotation process, and the second arc groove inside the spherical shell limits the transmission ball, so that the transmission ball moves in coordination inside the corresponding second arc groove, and the first arc groove limits the transmission ball, so that the spherical block drives the circular rod to rotate axially in the tilted state, thereby driving the top plate and the bottom plate to rotate in the tilted state.

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