Casting structure of cast steel gear

Abstract

The casting structure of the cast steel gear comprises a gear pouring cavity, a connecting plate fixedly connected to the surface of the gear pouring cavity, a dead head fixedly connected to the surface of the connecting plate, a sprue penetrating through the center of the gear pouring cavity, a pouring opening fixedly connected to the top end of the sprue, and a cross gate fixedly connected to the bottom end of the sprue. The surface of the cross gate is fixedly connected with an ingate, and the top end of the ingate is fixedly connected to the bottom face of the gear pouring cavity. The number of the ingates is two, the two ingates are located at the ends close to the transverse pouring gate respectively, the included angle between each ingate and the horizontal plane of the gear pouring cavity ranges from 40 degrees to 50 degrees, and the two ingates are symmetrically arranged along the center line of the gear pouring cavity. The cast steel gear has the advantages of being reasonable in structural design, easy to machine, low in machining and manufacturing cost and convenient to operate, effectively improving the utilization rate and production efficiency of cast steel gear materials, meanwhile remarkably improving the surface quality and the overall performance of the gear, and improving economic benefits.

Description

Technical Field

[0001] This utility model relates to the field of casting technology, specifically to a casting structure for cast steel gears. Background Technology

[0002] Gears are indispensable components in mechanical transmission systems, and their performance directly affects the efficiency and lifespan of the entire system. Cast steel gears, due to their excellent comprehensive mechanical properties, high load-bearing capacity, and wear resistance, are widely used in heavy-duty, high-speed, and harsh working environments. However, traditional casting steel gear manufacturing methods have many shortcomings, such as numerous internal defects, porosity at tooth tips, frequent inclusions, and difficult processing. These problems result in high scrap and rework rates, inconsistent product quality, and limit their development and application.

[0003] With the continuous advancement of industrial technology, higher requirements are being placed on the precision, strength, and lifespan of gears. Therefore, developing a new type of cast steel gear casting structure to improve the overall performance and production efficiency of gears while reducing production costs has significant practical implications and broad market prospects. Utility Model Content

[0004] The purpose of this utility model is to provide a casting structure for cast steel gears that has a reasonable structural design, ingenious concept, is easy to process, has low processing and manufacturing costs, is convenient to operate, effectively improves the utilization rate and production efficiency of cast steel gear materials, and significantly improves the surface quality and overall performance of gears, thereby increasing economic benefits.

[0005] This utility model discloses a casting structure for a cast steel gear, including a gear casting cavity. A connecting plate is fixedly connected to the surface of the gear casting cavity, and a riser is fixedly connected to the surface of the connecting plate. A sprue is installed through the center of the gear casting cavity, and a sprue opening is fixedly connected to the top of the sprue. A gating system is fixedly connected to the bottom of the sprue, and an ingate is fixedly connected to the surface of the ingate. The top of the ingate is fixedly connected to the bottom surface of the gear casting cavity.

[0006] The number of ingates is two, and the two ingates are respectively located at the ends near the horizontal runner. The angle between the ingate and the horizontal plane of the gear casting cavity is 40°-50°. The two ingates are symmetrically arranged along the center line of the gear casting cavity.

[0007] The connecting plate, with a certain machining allowance during gear casting, connects the recessed parts of the gear teeth in the casting cavity, serving to fix and connect the gear casting cavity, facilitating subsequent gear machining. The machining allowance allows for continuous cutting during gear machining, protecting the tool, reducing tool wear, and extending tool life. The ingate, with an angle of 40°-50° between itself and the gear casting cavity, cuts counterclockwise into the cavity. After the molten steel is poured in, it rotates internally, effectively collecting inclusions from the cavity and molten steel into the riser, reducing gear machining defects, especially casting defects at the gear teeth. The riser, combined with the chills, significantly improves the gear casting yield. The molten steel is refined using an external ladle refining technology. The process involves purifying the molten steel of gases and non-metallic inclusions, using a heat separator to bake the mold cavity, and strictly controlling the pouring temperature, speed, and mold opening time. The system includes a sprue, gating system, runner, and ingate. Molten steel enters these systems through the sprue, creating a flow space. The gating system guides the molten steel into the runner and ingate, providing sufficient pressure head to overcome frictional resistance and fill the mold within a specified time. This process also mitigates the impact of the molten steel, shortens the turbulent flow zone, and ensures a smooth flow into the runner, improving pressure distribution and ensuring uniform flow in the ingate. This process also facilitates the rising of inclusions and air bubbles to the top of the runner. This effectively improves the material utilization and production efficiency of cast steel gears, while significantly enhancing surface quality and overall performance. It is suitable not only for mass production but also for meeting the high performance requirements of gears under special operating conditions, demonstrating significant technical advantages and economic benefits.

[0008] A chill is fixedly connected to the bottom surface of the gear casting cavity.

[0009] The number of chills is two, and the two chills are symmetrically arranged along the center line of the gear casting cavity. The chills are cylindrical in structure.

[0010] The chills installed play an important role in enhancing the function of risers and preventing shrinkage cavities and porosity in castings, thus ensuring casting quality. They can control shrinkage and achieve directional solidification.

[0011] The number of risers is two, and the two risers are symmetrically arranged along the center line of the gear casting cavity.

[0012] The beneficial effects of this utility model are:

[0013] 1) The connecting plate, with a certain machining allowance during gear casting, connects the recessed parts of the gear teeth in the casting cavity, serving to fix and connect the gear casting cavity, facilitating subsequent gear machining. The machining allowance allows for continuous cutting during gear machining, protecting the tool, reducing tool wear, and extending tool life. The ingate, with an angle of 40°-50° between itself and the gear casting cavity, cuts counterclockwise into the cavity. After the molten steel is poured in, it rotates internally. Combined with the connecting plate at the top, this effectively collects inclusions from the cavity and molten steel into the riser, reducing gear machining defects, especially casting defects at the gear teeth. The riser, along with the chills, significantly improves the gear casting yield. The molten steel is refined using ladle refining technology. The process involves purifying the molten steel of gases and non-metallic inclusions, using a heat separator to bake the mold cavity, and strictly controlling the pouring temperature, speed, and mold opening time. The system includes a sprue, gating system, runner, and ingate. Molten steel enters through the sprue, creating a flow space. The gating system guides the molten steel into the runner and ingate, providing sufficient pressure head to overcome frictional resistance and fill the mold within a specified time. This process also mitigates the impact of the molten steel, shortens the turbulent zone, and ensures a smooth flow into the runner, improving pressure distribution and ensuring uniform flow in the ingate. This process also facilitates the rising of inclusions and air bubbles to the top of the runner. This effectively improves the material utilization and production efficiency of cast steel gears, while significantly improving the surface quality and overall performance. It is suitable not only for mass production but also for meeting the high performance requirements of gears under special working conditions, demonstrating significant technical advantages and economic benefits.

[0014] 2) The chills provided can play an important role in improving the function of the riser and preventing shrinkage cavities and porosity in the casting, thus ensuring the quality of the casting. They can control shrinkage and achieve directional solidification.

[0015] 3) This casting structure has a reasonable structural design, ingenious concept, and is easy to process. It has low processing and manufacturing costs, is convenient to operate, and effectively improves the material utilization rate and production efficiency of the cast steel gear body. At the same time, it significantly improves the surface quality and overall performance of the gear, improves economic benefits, and can effectively reduce defects such as porosity and slag inclusions in the gear production process, reduce the rework and scrap rate of gears, reduce production costs, and improve production quality. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is the front view of the present invention;

[0018] Figure 3 This is a schematic diagram of the riser connection structure in this utility model.

[0019] In the diagram: 1. Gating inlet; 2. Riser; 3. Connecting plate; 4. Gear casting cavity; 5. Inner runner; 6. Straight runner; 7. Horizontal runner; 8. Chill. Detailed Implementation

[0020] Example 1.

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] This utility model includes a pouring inlet 1, a riser 2, a connecting plate 3, a gear casting cavity 4, an inner gating channel 5, a straight gating channel 6, and a horizontal gating channel 7. The specific structure includes a gear casting cavity 4, a connecting plate 3 fixedly connected to the surface of the gear casting cavity 4, a riser 2 fixedly connected to the surface of the connecting plate 3, a straight gating channel 6 installed through the center of the gear casting cavity 4, a pouring inlet 1 fixedly connected to the top of the straight gating channel 6, a horizontal gating channel 7 fixedly connected to the bottom of the straight gating channel 6, an inner gating channel 5 fixedly connected to the surface of the horizontal gating channel 7, and the top of the inner gating channel 5 fixedly connected to the bottom surface of the gear casting cavity 4.

[0023] The number of inner gating channels 5 is two. The two inner gating channels 5 are respectively located at the ends near the horizontal gating channel 7. The angle between the inner gating channel 5 and the horizontal plane of the gear casting cavity 4 is 40°-50°. The two inner gating channels 5 are symmetrically arranged along the center line of the gear casting cavity 4.

[0024] The number of risers 2 is two, and the two risers 2 are symmetrically arranged along the center line of the gear casting cavity 4; the risers 2 are waist-shaped risers.

[0025] The connecting plate 3 has a machining allowance of 12mm. This allowance is used to ensure smooth connection of the tooth tip part of the gear casting cavity 4, thus guaranteeing the circulation of molten steel and the continuity of the processing.

[0026] The inner gating channel 5 is obliquely cut into the gear casting cavity 4, causing the molten steel to rotate in the cavity. In conjunction with the connecting part of the upper tooth tip connecting plate 3, the molten steel can rotate smoothly in the gear casting cavity 4. The rotation of the molten steel causes slag and other particles in the molten steel to accumulate in the riser 2.

[0027] Usage: The machining allowance of the surface connecting plate 3 of the gear casting cavity 4 is 12mm, and the machining allowance is used to connect the tooth tip obstruction of the gear casting cavity 4. A split molding method is adopted, with the entire casting placed in the lower box, and the riser 2 and the machined portion of the riser surface placed in the upper box. The gating system uses a sprue 6, a runner 7, and an ingate 5 connected by a sleeve. The two ingates 5 enter the gear casting cavity 4 at a 45° angle counterclockwise to the casting. The gap between the sleeves is ≤1.5mm. After wrapping, the gating system is sealed with tape to prevent molding sand from falling into the gating system. Two waist-shaped risers 2 are set, interrupted in the middle by a chill 8 to extend the feeding distance of the riser 2 and reduce the amount of riser 2 used. Furan resin sand is used for molding, with a resin to sand ratio of 1.1% and a hardener to resin ratio of 35%. The overall strength of the sand mold reaches 0.65 MPa, and the silica sand ash content is <1%. Before molding and core making, confirm that the silica sand, furan resin, and curing agent dosage are sufficient, and confirm that the molding sand quality meets the process requirements, i.e., the average strength of the molding sand pattern ≥ 0.60 MPa; during molding, make φ5mm vent holes in the mold, stopping when the holes are about 20-30mm away from the casting; after molding, apply an alcohol-based coating with a thickness of 0.6-1mm; coating mixing requirements: first coat 35-45 Baume degree, second coat 30-40 Baume degree, third coat 35-45 Baume degree, and fourth coat 30-40 Baume degree. For a coating of 20-30, stir well before use. Ignite after each coat of sand mold coating. Remove debris from the gating system promptly after coating. Close the mold after coating. Preheat the mold cavity to 200℃ for 15 minutes before pouring. Control the alloy composition during steel smelting. After the steel is tapped, use ladle refining technology and blow argon from the bottom for three minutes to purify the gas and non-metallic inclusions in the steel. Pour at 1560-1580℃ and keep warm for 6-8 hours after pouring before closing the mold.

[0028] Example 2.

[0029] This utility model includes a pouring inlet 1, a riser 2, a connecting plate 3, a gear casting cavity 4, an inner gating system 5, a straight gating system 6, a horizontal gating system 7, and a chill 8. The specific structure includes a gear casting cavity 4, with a connecting plate 3 fixedly connected to the surface of the gear casting cavity 4, a riser 2 fixedly connected to the surface of the connecting plate 3, a straight gating system 6 installed through the center of the gear casting cavity 4, a pouring inlet 1 fixedly connected to the top of the straight gating system 6, a horizontal gating system 7 fixedly connected to the bottom of the straight gating system 6, an inner gating system 5 fixedly connected to the surface of the horizontal gating system 7, and the top of the inner gating system 5 fixedly connected to the bottom surface of the gear casting cavity 4.

[0030] The number of inner gating channels 5 is two. The two inner gating channels 5 are respectively located at the ends near the horizontal gating channel 7. The angle between the inner gating channel 5 and the horizontal plane of the gear casting cavity 4 is 40°-50°. The two inner gating channels 5 are symmetrically arranged along the center line of the gear casting cavity 4.

[0031] The bottom surface of the gear casting cavity 4 is fixedly connected with a chill.

[0032] The number of chills 8 is two, and the two chills 8 are symmetrically arranged along the center line of the gear casting cavity 4. The chills 8 are cylindrical structures.

[0033] The number of risers 2 is two, and the two risers 2 are symmetrically arranged along the center line of the gear casting cavity 4; the risers 2 are waist-shaped risers.

[0034] The connecting plate 3 has a machining allowance of 12mm. This allowance is used to ensure smooth connection of the tooth tip part of the gear casting cavity 4, thus guaranteeing the circulation of molten steel and the continuity of the processing.

[0035] The inner gating channel 5 is obliquely cut into the gear casting cavity 4, causing the molten steel to rotate in the cavity. In conjunction with the connecting part of the upper tooth tip connecting plate 3, the molten steel can rotate smoothly in the gear casting cavity 4. The rotation of the molten steel causes slag and other particles in the molten steel to accumulate in the riser 2.

[0036] The chill iron 8 has a specification of φ80*80 mm.

[0037] Usage: The machining allowance of the surface connecting plate 3 of the gear casting cavity 4 is 12mm, and the machining allowance is used to connect the tooth tip obstruction of the gear casting cavity 4. A split molding method is adopted, with the entire casting placed in the lower box, and the riser 2 and the machined portion of the riser surface placed in the upper box. The gating system uses a sprue 6, a runner 7, and an ingate 5 connected by a sleeve. The two ingates 5 enter the gear casting cavity 4 at a 45° angle counterclockwise to the casting. The gap between the sleeves is ≤1.5mm. After wrapping, the gating system is sealed with tape to prevent molding sand from falling into the gating system. Two waist-shaped risers 2 are set, interrupted in the middle by a chill 8 to extend the feeding distance of the riser 2 and reduce the amount of riser 2 used. Furan resin sand is used for molding, with a resin to sand ratio of 1.1% and a hardener to resin ratio of 35%. The overall strength of the sand mold reaches 0.65 MPa, and the silica sand ash content is <1%. Before molding and core making, confirm that the silica sand, furan resin, and curing agent dosage are sufficient, and confirm that the molding sand quality meets the process requirements, i.e., the average strength of the molding sand pattern ≥ 0.60 MPa; during molding, make φ5mm vent holes in the mold, stopping when the holes are about 20-30mm away from the casting; after molding, apply an alcohol-based coating with a thickness of 0.6-1mm; coating mixing requirements: first coat 35-45 Baume degree, second coat 30-40 Baume degree, third coat 35-45 Baume degree, and fourth coat 30-40 Baume degree. For a coating of 20-30, stir well before use. Ignite after each coat of sand mold coating. Remove debris from the gating system promptly after coating. Close the mold after coating. Preheat the mold cavity to 200℃ for 15 minutes before pouring. Control the alloy composition during steel smelting. After the steel is tapped, use ladle refining technology and blow argon from the bottom for three minutes to purify the gas and non-metallic inclusions in the steel. Pour at 1560-1580℃ and keep warm for 6-8 hours after pouring before closing the mold.

[0038] The chiller 8 plays an important role in enhancing the function of the riser 2 and preventing shrinkage cavities and porosity in the casting, thus ensuring the quality of the casting. It can control shrinkage and achieve directional solidification.

Claims

1. A casting structure for a cast steel gear wheel comprising a gear wheel casting cavity (4), characterized in that: The surface of the gear pouring cavity (4) is fixedly connected with a connecting plate (3), the surface of the connecting plate (3) is fixedly connected with a riser (2), a straight sprue (6) is installed through the central position of the gear pouring cavity (4), the top end of the straight sprue (6) is fixedly connected with a pouring opening (1), the bottom end of the straight sprue (6) is fixedly connected with a cross sprue (7), the surface of the cross sprue (7) is fixedly connected with an inner sprue (5), and the top end of the inner sprue (5) is fixedly connected to the bottom surface of the gear pouring cavity (4).

2. A cast structure for a cast steel gear as set forth in claim 1, characterized in that: The number of the inner sprue (5) is two, the two inner sprues (5) are respectively arranged near the end of the cross sprue (7), the included angle between the inner sprue (5) and the horizontal plane of the gear pouring cavity (4) is 40°-50°, and the two inner sprues (5) are symmetrically arranged along the center line of the gear pouring cavity (4).

3. A cast structure for a cast steel gear as defined in claim 2 wherein: The bottom surface of the gear pouring cavity (4) is fixedly connected with a cold iron (8).

4. A cast structure for a cast steel gear as defined in claim 3 wherein: The number of the cold iron (8) is two, the two cold irons (8) are symmetrically arranged along the center line of the gear pouring cavity (4), and the cold iron (8) is a cylindrical structure.

5. A cast structure for a cast steel gear as defined in claim 4 wherein: The number of the riser (2) is two, and the two risers (2) are symmetrically arranged along the center line of the gear pouring cavity (4).

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