A core box

Abstract

A core box comprises a lower core box, an upper core box, a sand shooting device and a core pushing device; an upper cavity is provided on the upper core box, a lower cavity is provided on the lower core box, and after the upper core box and the lower core box are molded together, the upper cavity and the lower cavity form a molding cavity of a sand core; the sand shooting device comprises a sand shooting plate, a sand shooting nozzle and a positioning pin installed at the lower part of the sand shooting plate, a step hole is provided in the sand shooting nozzle, comprising a large step portion at the upper end and a small step portion connected to the lower end of the large step portion, a sand retaining block is installed at the bottom of the large step portion, the sand retaining block is a step cylinder with a large upper portion and a small lower portion, the diameter of the small step cylinder is larger than the diameter of the small step portion of the step hole, and a plurality of notches are evenly distributed on the outer circumference of the large step cylinder; the upper end of the step hole is flush with the upper end of the sand shooting nozzle, and the lower end is flush with the lower end of the sand shooting nozzle; the core pushing device comprises a core pushing plate, a core pushing rod and a positioning pin installed at the lower part of the core pushing plate; the sand shooting rod can be greatly shortened, or even left without residue, which is convenient for manual removal, saves the amount of coated sand, and reduces the cost of sand cores.

Description

Technical Field

[0001] The invention relates to a core box for producing coated sand cores and belongs to the field of casting process equipment. Background Art

[0002] At present, the production of coated sand cores requires the production of sand core boxes first, and then the core boxes are connected to the equipment for production. Sand core boxes generally include a complete set of sand shooting devices such as sand shooting plates and sand shooting nozzles. During sand shooting, the equipment blows the granular coated sand through the nozzle and the sand shooting holes in the mold into the core box cavity to form a sand core shape. The sand shooting holes in the mold are also filled with sand particles, forming sand shooting rods. Since the mold has a certain thickness, this will form a long residual sand shooting rod left on the surface of the sand core. After the sand core is out of the mold cavity, the remaining sand shooting rods need to be removed manually with tools. The thicker the mold, the longer the residual sand shooting rods are generally, the more troublesome it is to remove manually, and the more sand is wasted. Summary of the invention

[0003] The object of the present invention is to overcome the above-mentioned deficiencies in the prior art and provide a core box which can greatly shorten the sand shooting rod, even leaving no residue, facilitate manual removal, save the amount of coated sand, and reduce the cost of sand cores.

[0004] The technical solution of the present invention is:

[0005] A core box, comprising a lower core box, an upper core box, a sand shooting device, and a core pushing device; the upper core box is provided with an upper cavity, the lower core box is provided with a lower cavity, and after the upper core box and the lower core box are molded together, the upper cavity and the lower cavity form a molding cavity for a sand core;

[0006] The sand shooting device comprises a sand shooting plate, a sand shooting nozzle installed at the lower part of the sand shooting plate, and a positioning pin. A step hole is arranged in the sand shooting nozzle, including a large step portion at the upper end and a small step portion connected to the lower end of the large step portion. A sand blocking block is arranged at the bottom of the large step portion. The sand blocking block is a step cylinder with a large upper portion and a small lower portion. The diameter of the small step cylinder is larger than the diameter of the small step portion of the step hole. A plurality of notches are evenly distributed on the outer circumference of the large step cylinder. The upper end of the step hole is flush with the upper end of the sand shooting nozzle, and the lower end is flush with the lower end of the sand shooting nozzle.

[0007] The core-pushing device comprises a core-pushing plate, a core-pushing rod installed at the lower part of the core-pushing plate, and two positioning pins;

[0008] The upper core box is provided with sand shooting holes, and the sand shooting nozzle of the sand shooting device and the core pushing rod of the core pushing device correspond to the sand shooting holes respectively; the upper core box is also provided with guide holes, and the positioning pin 1 of the sand shooting device and the positioning pin 2 of the core pushing device correspond to the guide holes respectively.

[0009] The large step portion of the step hole includes a first large step portion and a second large step portion connected to the lower end of the first large step portion. The middle part of the bottom surface of the second large step portion is a truncated cone-shaped protrusion. The diameter of the upper plane of the protrusion is larger than the diameter of the small step portion of the step hole. The diameter of the lower plane of the protrusion matches the diameter of the small cylindrical table of the sand retaining block. The lower bottom surface of the small cylindrical table of the sand retaining block is provided with a groove matching the protrusion.

[0010] An annular groove is provided on the outer periphery of the bottom surface of the second large step portion, and the bottom surface of the second large step portion is connected to the arc of the side wall of the second large step portion.

[0011] The outer end surface of the sand shooting nozzle is a stepped cylindrical surface, including a first cylindrical surface, a second cylindrical surface, and a third cylindrical surface. The diameter of the second cylindrical surface is larger than that of the first cylindrical surface and the third cylindrical surface.

[0012] A sealing groove is arranged at the lower end of the second cylindrical surface, and a rubber ring is arranged in the sealing groove.

[0013] The sealing groove is an annular groove body, and the cross-section of the sealing groove is a cylindrical cone. The diameter of the upper bottom surface of the cylindrical cone is larger than the diameter of the lower bottom surface. The rubber ring is an annular body matching the sealing groove, and the inner and outer end surfaces of the rubber ring are both inclined; the lower plane of the rubber ring is 1-2mm higher than the lower plane of the second cylindrical surface.

[0014] The sand shooting hole is provided with an inlay sleeve.

[0015] A positioning sleeve is arranged at the guide hole.

[0016] The guide hole is a step countersunk hole, comprising a large step hole and a small step hole connected to the large step hole, and the step-shaped positioning sleeve is arranged in the guide hole.

[0017] The sand blasting plate is provided with a threaded hole 1 for installing a positioning pin 1 and a threaded hole 2 for installing a sand blasting nozzle.

[0018] Beneficial effects of the invention: Compared with the prior art, the invention can greatly shorten the sand shooting rod, even without residue, facilitate manual removal, save the amount of coated sand, and reduce the cost of sand cores; it is more suitable for the production of larger core shooting sand cores. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 It is a schematic diagram of the structure of the present invention;

[0021] Figure 3 It is a front view of the sand retaining block;

[0022] Figure 4 It is a top view of the sand retaining block;

[0023] Figure 5 It is a structural diagram of a sand-shooting nozzle;

[0024] Figure 6 It is a schematic diagram of the structure of the rubber ring;

[0025] In the figure, 1, lower core box, 2, upper core box, 3, positioning sleeve, 4, threaded hole one, 5, positioning pin one, 6, threaded hole two, 7, sand shooting nozzle, 8, rubber ring, 9, sand shooting plate, 10, sleeve, 11, sand blocking block, 12, core push rod, 13, core push plate, 14, step hole, 15, sealing groove. DETAILED DESCRIPTION

[0026] Figure 1 , Figure 2 The present invention comprises a lower core box 1, an upper core box 2, a sand shooting device, and a core pushing device; the upper core box 2 is provided with an upper cavity, and the lower core box 1 is provided with a lower cavity. After the upper core box 2 and the lower core box 1 are molded together, the upper cavity and the lower cavity form a molding cavity of the sand core.

[0027] The sand shooting device includes a sand shooting plate 9, a sand shooting nozzle 7 and a positioning pin installed at the lower part of the sand shooting plate 9. The inside of the sand shooting nozzle 7 is a step hole 14, including a large step hole at the upper end and a small step hole connected to the lower end of the large step hole. A sand blocking block 11 is installed in the large step hole. The sand blocking block 11 is a step cylinder with a larger upper part and a smaller lower part. The diameter of the small step cylinder is larger than the diameter of the small step part of the step hole 14, and a plurality of notches are evenly distributed on the outer circumference of the large step cylinder; the upper end of the step hole 14 is flush with the upper end of the sand shooting nozzle 7, and the lower end is flush with the lower end of the sand shooting nozzle 7; the sand shooting plate 9 is provided with a threaded hole 4 for installing a positioning pin and a threaded hole 6 for installing the sand shooting nozzle 7.

[0028] The core jacking device comprises a core jacking plate 13, a core jacking rod 12 installed at the lower part of the core jacking plate, and two positioning pins.

[0029] The upper core box 2 is provided with sand shooting holes, and the sand shooting nozzle 7 of the sand shooting device and the core pushing rod 12 of the core pushing device correspond to the sand shooting holes respectively; the upper core box 2 is also provided with guide holes, and the positioning pin 1 of the sand shooting device and the positioning pin 2 of the core pushing device correspond to the guide holes respectively.

[0030] An insert sleeve 10 is installed at the sand shooting hole, and the guide hole is a step countersunk hole, including a large step hole and a small step hole connected under the large step hole, and a step-shaped positioning sleeve 3 is installed in the guide hole.

[0031] Figure 3 , Figure 4 In the figure, the sand retaining block 11 is a cylinder with a small upper step and a large lower step. The diameter of the small step cylinder is larger than the diameter of the small step portion of the step hole 14, and four notches are evenly distributed on the outer circumference of the large step cylinder.

[0032] Figure 5 , Figure 6The inside of the sand shooting nozzle 7 is a step hole 14, including a large step hole at the upper end and a small step hole connected to the lower end of the large step hole. The large step portion of the step hole 14 includes a first large step portion and a second large step portion connected to the lower end of the first large step portion. The middle part of the bottom surface of the second large step portion is a truncated cone-shaped protrusion. The diameter of the upper plane of the protrusion is larger than the diameter of the small step portion of the step hole 14. The diameter of the lower plane of the protrusion matches the diameter of the small cylindrical stage of the sand retaining block 11. The bottom surface of the small cylindrical stage of the sand retaining block 11 is provided with a groove matching the protrusion. The outer periphery of the bottom surface of the second large step portion is provided with an annular groove. The bottom surface of the second large step portion is connected to the arc of the side wall of the second large step portion. The provision of the annular groove can increase the cavity space between the large cylindrical stage of the sand retaining block 11 and the bottom of the large step portion of the step hole 14, which is conducive to increasing the reaction force of high-pressure blowing during sand shooting to blow the sand retaining block 11 The sand-shooting nozzle 7 can be raised and at the same time, residual sand can be accumulated to prevent residual sand from entering the small step portion of the step hole 14 to form a sand-shooting rod. The provision of a truncated cone-shaped protrusion is also conducive to blowing up the sand-blocking block 11; the outer end face of the sand-shooting nozzle 7 is a stepped cylindrical surface, including a first cylindrical surface, a second cylindrical surface, and a third cylindrical surface, and the diameter of the second cylindrical surface is larger than that of the first cylindrical surface and the third cylindrical surface; a sealing groove 15 is provided at the lower end portion of the second cylindrical surface, and a rubber ring 8 is installed in the sealing groove 15. The sealing groove 15 is an annular groove body, and the cross-section of the sealing groove 15 is a cylindrical table. The diameter of the upper bottom surface of the cylindrical table is larger than the diameter of the lower bottom surface. The rubber ring 8 is an annular body matching the sealing groove 15, and the inner and outer end faces of the rubber ring 8 are both inclined; after the rubber ring 8 is pressed into the sealing groove 15, the lower plane is higher than the lower plane of the second cylindrical surface by 1-2mm, which can effectively ensure that the sand is pressed tightly during sand blowing without leaking air pressure and sand particles.

[0033] When in use, the sand shooting plate 9 is pressed down quickly, and the positioning pin 15 on the sand shooting plate 9 first enters the positioning sleeve 3 on the guide hole of the upper core box 2, and the lower end of the sand shooting nozzle 7 extends into the inner hole of the sleeve 10 of the upper core box 2 along with the sand shooting plate 9, until the rubber ring 8 at the lower end of the second cylindrical surface of the sand shooting nozzle 7 is tightly attached to the upper surface of the upper core box 2, and the lower end plane of the sand shooting nozzle 7 is now flush with the upper surface of the upper cavity of the upper core box 2; start sand shooting, and sand particles are blown into the inner cavity of the sand shooting nozzle 7 with high air pressure. At this time, due to the four notches evenly distributed on the outer circumference of the large step cylinder of the sand retaining block 11, the high air pressure reaction force will flush the sand retaining block 11 with a gap, and the sand particles enter the small step part at the bottom of the step hole 14 from the gap, and then enter the molding cavity of the sand core formed by the lower core box 1 and the upper core box 2. After the sand particles fill the cavity, the pressure is relieved and the sand shooting is ended. At this time, the sand retaining block 11 in the sand shooting nozzle 7 falls back to the sand shooting nozzle 7 The step hole 14 plane can block the sand from falling, effectively preventing the sand from falling into the sand shooting hole to form a sand shooting rod. As the sand shooting plate 9 moves upward rapidly, the positioning pin 1 5 and the sand shooting nozzle 7 quickly detach from the upper core box 2 and return to the starting height; then, the sand shooting plate 9 moves horizontally out of the range of the upper core box 2, and waits until the sand in the molding cavity solidifies to become a sand core, and the top core plate 13 moves to the top of the upper core box 2. As the top core plate 13 moves downward rapidly, the positioning pin 2 on the top core plate 13 first enters the gap guide of the positioning sleeve 3 of the upper core box 2, and the lower end of the top core rod 12 extends into the inner hole of the insert sleeve 10 of the upper core box 2 with the top core plate 13 to contact the surface of the sand core to eject the sand core; the present invention is more suitable for a larger plane of the size and position of the sand shooting part set for the present invention. Since the inserted nozzle 7 needs to be placed in a sand retaining block 11, the structure is more complicated and is about 15-20mm larger in diameter than the general nozzle.

Claims

1. A core box, characterized in that: It comprises a lower core box (1), an upper core box (2), a sand shooting device, and a core pushing device; the upper core box (2) is provided with an upper cavity, the lower core box (1) is provided with a lower cavity, and after the upper core box (2) and the lower core box (1) are molded together, the upper cavity and the lower cavity form a molding cavity for the sand core; The sand shooting device comprises a sand shooting plate (9), a sand shooting nozzle (7) and a positioning pin installed at the bottom of the sand shooting plate (9); a step hole (14) is provided in the sand shooting nozzle (7), comprising a large step portion at the upper end and a small step portion connected to the lower end of the large step portion; a sand blocking block (11) is installed at the bottom of the large step portion; the sand blocking block (11) is a step cylinder with a larger upper portion and a smaller lower portion; the diameter of the small step cylinder is larger than the diameter of the small step portion of the step hole (14); and a plurality of notches are evenly distributed on the outer circumference of the large step cylinder; the upper end of the step hole (14) is flush with the upper end of the sand shooting nozzle (7), and the lower end is flush with the lower end of the sand shooting nozzle (7); The core pushing device comprises a core pushing plate (13), a core pushing rod (12) mounted at the bottom of the core pushing plate, and two positioning pins; The upper core box (2) is provided with a sand shooting hole, and the sand shooting nozzle (7) of the sand shooting device and the core pushing rod (12) of the core pushing device respectively correspond to the sand shooting holes; the upper core box (2) is also provided with a guide hole, and the first positioning pin of the sand shooting device and the second positioning pin of the core pushing device respectively correspond to the guide holes; The large step portion of the step hole (14) comprises a first large step portion and a second large step portion connected to the lower end of the first large step portion, the middle of the bottom surface of the second large step portion is a truncated cone-shaped protrusion, the diameter of the upper plane of the protrusion is larger than the diameter of the small step portion of the step hole (14), the diameter of the lower plane of the protrusion matches the diameter of the small step cylinder of the sand retaining block (11), and the lower bottom surface of the small step cylinder of the sand retaining block (11) is provided with a groove matching the protrusion; The outer end surface of the sand shooting nozzle (7) is a stepped cylindrical surface, comprising a first cylindrical surface, a second cylindrical surface and a third cylindrical surface, wherein the diameter of the second cylindrical surface is greater than that of the first cylindrical surface and the third cylindrical surface.

2. The core box according to claim 1, characterized in that: An annular groove is provided on the outer periphery of the bottom surface of the second large step portion, and the bottom surface of the second large step portion is connected to the arc of the side wall of the second large step portion.

3. The core box according to claim 1, characterized in that: A sealing groove (15) is provided at the lower end of the second cylindrical surface, and a rubber ring (8) is installed in the sealing groove (15).

4. The core box according to claim 3, characterized in that: The sealing groove (15) is an annular groove body, and the cross section of the sealing groove (15) is a cylindrical platform, the diameter of the upper bottom surface of the cylindrical platform is larger than the diameter of the lower bottom surface, and the rubber ring (8) is an annular body matching the sealing groove (15), and the inner and outer end surfaces of the rubber ring (8) are both inclined; the lower plane of the rubber ring (8) is 1-2 mm higher than the lower plane of the second cylindrical surface.

5. The core box according to claim 1, characterized in that: The sand shooting hole is provided with an insert sleeve (10).

6. The core box according to claim 1, characterized in that: A positioning sleeve (3) is installed at the guide hole.

7. The core box according to claim 6, characterized in that: The guide hole is a stepped countersunk hole, comprising a large stepped hole and a small stepped hole connected to the large stepped hole. The positioning sleeve (3) is stepped in shape, and the stepped positioning sleeve (3) is installed in the guide hole.

8. The core box according to claim 1, characterized in that: The sand blasting plate (9) is provided with a threaded hole (4) for mounting a positioning pin (4) and a threaded hole (6) for mounting a sand blasting nozzle (7).

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