Conical carburizing steel bearing outer ring quenching die
By optimizing the design of the outer ring quenching mold of conical carburized steel bearings, the problem of uneven cooling of the existing mold is solved, the uniformity of the carburized layer and the consistency of the outer ring size of the bearings is achieved, and the quality and service life of the heat treatment are improved.
Patent Information
- Application Number
- CN202422098302.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-08-28
AI Technical Summary
The existing quenching mold design cannot meet the heat treatment requirements of conical carburized steel bearings of complex shapes, large sizes, and thick walls, resulting in uneven cooling and cannot guarantee the service life and heat treatment quality of the bearing.
A conical carburized steel bearing outer ring quenching mold is designed, including a conical pedestal and a cylindrical pedestal. Multiple through upper and lower oil tanks are provided to increase the depth and width of the oil tank, optimize the quenching cooling capacity, and support the ferrule through the straight pedestal part to control shrinkage and deformation.
The quenching cooling capacity is improved, ensuring the uniformity of the carburized layer and the dimensional consistency of the outer ring of the bearing, and improving the heat treatment quality and service life of the bearing.
Smart Images
Figure CN223087857U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of bearing heat treatment, and particularly relates to a quenching die for the outer ring of a conical carburizing steel bearing and a quenching process thereof. Background Art
[0002] In recent years, with the development of China's manufacturing industry, the shape of bearings has become more and more complex, the size has become larger and larger, the effective wall thickness has become thicker and thicker, and the angle design of cold-rolled conical rings made of steel has also become larger and larger. If the previous quenching die design method is adopted, it is no longer possible to meet the requirements of heat treatment of carburizing steel bearing rings and ensure the service life of cold-rolled conical bearings made of steel. Therefore, it is necessary to design a quenching die for conical carburizing steel bearings during the heat treatment quenching process. Summary of the Invention
[0003] Aiming at the defects existing in the above-mentioned prior art, the purpose of the utility model is to provide a quenching die for the outer ring of a conical carburizing steel bearing and a quenching process thereof, so as to overcome the large-angle quenching taper problem of cold-rolled conical carburizing steel bearings made of steel.
[0004] To achieve the above purpose, the technical solution adopted by the utility model is as follows: a quenching die for the outer ring of a conical carburizing steel bearing, which includes a conical frustum for supporting the inner surface of the bearing outer ring, and a cylindrical frustum integrally formed with the conical frustum at the bottom of the conical frustum; the conical frustum includes a straight frustum part and a tapered frustum part, the straight frustum part is a cylindrical structure, the straight frustum part is connected to the small-diameter end of the tapered frustum part, the outer diameter of the straight frustum part is the same as the outer diameter of the small-diameter end of the tapered frustum part, the outer diameter of the tapered frustum part gradually increases from top to bottom, the large-diameter end of the tapered frustum part is connected to the cylindrical frustum, and the outer diameter of the cylindrical frustum is greater than the outer diameter of the large-diameter end of the tapered frustum part; a plurality of upper oil flow grooves are arranged on the outer ring surface of the conical frustum, a plurality of lower oil flow grooves are arranged on the upper surface of the cylindrical frustum, the plurality of upper oil flow grooves and the plurality of lower oil flow grooves correspond one by one, and each group of corresponding upper oil flow grooves and lower oil flow grooves communicate with each other.
[0005] Further, the bottom of each group of corresponding upper oil flow grooves is perpendicular to the bottom of the lower oil flow grooves; a ring-shaped oil flow groove is arranged at the connection between the conical frustum and the cylindrical frustum, and the ring-shaped oil flow groove connects all the upper oil flow grooves and the lower oil flow grooves.
[0006] Further, the plurality of upper oil flow grooves on the outer ring surface of the conical frustum are distributed along the generatrix direction, the plurality of lower oil flow grooves on the upper surface of the cylindrical frustum are distributed radially, and the groove widths of the upper oil flow grooves and the lower oil flow grooves are the same.
[0007] Further, the plurality of upper oil flow grooves are vertically grooved from top to bottom, the bottom of the plurality of upper oil flow grooves is parallel to the axis of the conical frustum; the plurality of lower oil flow grooves are horizontally grooved, and the bottom of the plurality of lower oil flow grooves is perpendicular to the axis of the cylindrical frustum.
[0008] Further, the frustum of a cone and the frustum of a cylinder are coaxially arranged, and the frustum of a cone and the frustum of a cylinder are provided with a hollow cavity that penetrates through each other.
[0009] Further, a plurality of convex platforms are evenly distributed on the outer cylindrical surface of the frustum of a cylinder, and the upper surfaces of the plurality of convex platforms are continued with the downstream oil grooves.
[0010] Further, the outer diameter of the straight part of the frustum of a cone is 0.5 - 1 mm larger than the inner diameter of the wide end face of the bearing outer ring.
[0011] Further, the outer diameter of the large diameter end of the frustum part of the frustum of a cone is 1 - 4 mm smaller than the inner diameter of the narrow end face of the bearing outer ring.
[0012] Adopting the quenching process of the above-mentioned quenching die for the carburized carbon steel bearing outer ring of the cone type, the bearing outer ring is heated to 815 °C in a box furnace for austenitization, the holding time is 100 minutes. After taking out of the furnace, the outer ring is clamped on the quenching die and put into quenching oil at 40 - 50 °C for quenching, and then tempering is carried out. The tempering temperature is 155 °C and the time is 12 hours.
[0013] Further, the loading capacity of each furnace in the box furnace is two pieces, and the large end faces of the two bearing outer rings are stacked.
[0014] The beneficial effects of the present utility model are as follows: The quenching die of the present utility model uses the straight part to support the ring, and strictly controls the shrinkage and expansion deformation of the ring. Description of the Drawings
[0015] Figure 1 It is a cross-sectional view of the quenching die of the present utility model;
[0016] Figure 2 It is a top view of the quenching die of the present utility model;
[0017] Figure 3 It is a product drawing of the conical outer ring;
[0018] In the figure: 1. Frustum of a cone, 1.1 Straight part, 1.2 Frustum part, 2. Frustum of a cylinder, 3. Upstream oil groove, 4. Downstream oil groove, 5. Oil flow ring groove, 6. Hollow cavity, 7. Wide end face of the conical outer ring, 8. Narrow end face of the conical outer ring, 9. Inner diameter chamfer of the wide end face of the conical outer ring. Detailed Embodiments
[0019] In order to make the above-mentioned objects, features and advantages of the present utility model more obvious and understandable, the following will describe in detail the specific embodiments of the present utility model with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.
[0020] For the original quenching die of steel conical case carburized bearings (the outer diameter of the raceway is the same, the inner diameter is tapered, the thickest part of the raceway is 58 mm, and the thinnest part is 25 mm), the oil drainage port is designed to be small. At the same time, the design of the oil drainage port is carried out according to the angle of the outer raceway of the outer ring, and the actual oil groove for oil passage in the die is extremely narrow, and the oil flow rate is small, which cannot ensure the quenching cooling capacity. As a result, there is a great difference in cooling between the thickest part and the thinnest part of the conical case carburized bearings. At the same time, the die angle design is the same as the raceway angle, and combined with cooling, it cannot ensure that the outer diameter taper of both sides of the raceway is consistent, and neither the hardness nor the hardened layer depth can be guaranteed, resulting in the inability to ensure the heat treatment quality and service life of the cold-rolled conical bearings made of steel. Therefore, this patent optimizes the design of the original die.
[0021] See attached Figure 1-2 , a quenching die for the outer ring of a conical case carburized bearing, comprising a conical frustum 1 for supporting the inner surface of the bearing outer ring. The bottom of the conical frustum 1 has a cylindrical frustum 2 integrated with the conical frustum. The conical frustum 1 and the cylindrical frustum 2 are coaxially arranged. The outer diameter of the conical frustum 1 gradually increases from top to bottom, and the large-diameter end of the conical frustum 1 is connected to the cylindrical frustum 2. The outer diameter of the cylindrical frustum 2 is larger than the outer diameter of the large-diameter end of the conical frustum 1. The conical frustum includes a straight frustum part 1.1 and a tapered frustum part 1.2. The straight frustum part 1.1 is a cylindrical structure, and the straight frustum part 1.1 is connected to the small-diameter end of the tapered frustum part 1.2. The outer diameter of the straight frustum part 1.1 is the same as the outer diameter of the small-diameter end of the tapered frustum part 1.2. The outer diameter of the tapered frustum part 1.2 gradually increases from top to bottom, and the large-diameter end of the tapered frustum part 1.2 is connected to the cylindrical frustum 2. The outer diameter of the cylindrical frustum 2 is larger than the outer diameter of the large-diameter end of the tapered frustum part 1.2. A plurality of upper oil drainage grooves 3 are arranged on the outer ring surface of the conical frustum 1, and a plurality of lower oil drainage grooves 4 are arranged on the upper surface of the cylindrical frustum. The plurality of upper oil drainage grooves 3 and the plurality of lower oil drainage grooves 4 correspond one by one. Each group of corresponding upper oil drainage grooves 3 and lower oil drainage grooves 4 are mutually communicated. The bottom of each group of corresponding upper oil drainage grooves 3 and the bottom of the lower oil drainage grooves 4 are perpendicular to each other. A ring-shaped oil drainage groove 5 is arranged at the connection of the conical frustum 1 and the cylindrical frustum 2. The ring-shaped oil drainage groove 5 connects all the upper oil drainage grooves 3 and the lower oil drainage grooves 4.
[0022] Based on the above technical solution, the optimized quenching die for steel conical carburized carbon steel bearings increases the depth of the oil groove and cancels the angle design, so as to increase the quenching oil circulation of the quenching die and improve the quenching cooling capacity. The groove widths of the upper oil groove and the lower oil groove for oil passage are increased to 45 mm, with a large oil passage volume, further improving the quenching cooling capacity of the die and enhancing the cooling uniformity of the surface and the core of the steel conical carburized carbon steel bearings. The axial width of the straight platform part 1.1 matches the axial width of the inner diameter chamfer of the wide end face of the conical outer ring. Before the heat treatment of the conical outer ring, the inner diameter chamfer of the wide end face is first machined into a cylindrical straight platform surface, and after the heat treatment, the cylindrical straight platform surface is machined to form an arc chamfer.
[0023] Further, a plurality of upper oil grooves 3 on the outer ring surface of the conical frustum 1 are distributed along the generatrix direction, and a plurality of lower oil grooves 4 on the upper surface of the cylindrical frustum 2 are distributed radially. The groove widths of the upper oil grooves 3 and the lower oil grooves 4 are the same, both being 45 mm.
[0024] Further, a plurality of the upper oil grooves 3 are vertically grooved from top to bottom. The groove depths of the upper oil grooves 3 located in the frustum part 1.2 gradually increase from top to bottom. The bottoms of a plurality of the upper oil grooves 3 are parallel to the axis of the conical frustum 1. A plurality of the lower oil grooves 4 are horizontally grooved, and the bottoms of a plurality of the lower oil grooves 4 are perpendicular to the axis of the cylindrical frustum 2.
[0025] Further, the conical frustum 1 and the cylindrical frustum 2 are provided with a through hollow cavity 6.
[0026] Further, four convex platforms 7 are evenly distributed on the outer cylindrical surface of the cylindrical frustum 2, and the upper surface of the convex platform 7 continues with the lower oil groove 4.
[0027] Further, the outer diameter of the straight platform part 1.1 of the conical frustum is 0.5 - 1 mm larger than the inner diameter of the wide end face of the bearing outer ring. The outer diameter of the large diameter end of the frustum part 1.2 of the conical frustum is 1 - 4 mm smaller than the inner diameter of the narrow end face of the bearing outer ring.
[0028] Based on the above technical solution, by optimizing the die angle, it is achieved that the diameter dimension of the die at the thinnest part of the cone is smaller than the diameter dimension at the corresponding raceway, and the diameter dimension of the die at the thickest part of the cone is larger than the diameter dimension at the corresponding raceway. The taper of the outer diameter dimension of the raceway is less than 0.5 mm, thereby ensuring the uniformity of the carburized layer of the cold-rolled tapered bearings made of steel, improving the heat treatment quality and service life. After the outer ring quenching is completed, machining is carried out to remove the surplus. The different diameter dimensions of the wide end face and the narrow end face of the outer diameter of the raceway result in a taper of the outer diameter and the raceway, and the removal amounts are different during machining, resulting in uneven carburized layer depths. When designing the die, the dimensions of the die are based on the turning dimensions of the outer ring. Therefore, the dimensions of the tapered die are smaller than the turning diameter dimensions of the raceway, and the thickest point is larger than the maximum turning outer ring diameter dimension. Among them, the taper less than 0.5 mm is the product requirement for the outer cone. The larger the taper, the greater the impact on the carburized layer depth of the outer diameter and the outer raceway of the raceway after machining. Among them, the outer diameter of the straight platform part 1.1 is 0.5 - 1 mm larger than the inner diameter of the wide end face of the bearing outer ring, which can not only support the outer ring and play a role in limiting shrinkage, but also avoid the outer diameter of the straight platform part 1.1 being too large and getting stuck with the outer ring during the heat treatment process.
[0029] The process of secondary quenching of the outer ring is as follows: The bearing outer ring is machined by turning, leaving machining allowances. After turning, the outer ring is heated to 815 °C in a box furnace for austenitization, with a holding time of 100 minutes. The loading quantity per furnace is 2 pieces (stacked with large end faces facing each other). After taking out of the furnace, the 2 outer rings are placed on the above-mentioned die using a fixture, and then immediately quenched in fast quenching oil at 40 - 50 °C. The tempering temperature is: 155 °C, and the time is 12 hours.
[0030] After several years of production practice, the quenching die for tapered carburized steel bearings made of steel optimized has completely solved the problems of the large-angle outer ring taper and the inability to meet the uniformity of the hardened layer after turning. See Table 1 and Table 2.
[0031] Table 1. Table of dimensional changes of the outer ring during secondary quenching using the original quenching die
[0032] Outer ring serial number Allowance of the outer diameter of the wide end face after quenching from the finished product size / mm Allowance of the outer diameter of the narrow end face after quenching from the finished product size / mm Allowance of the outer diameter size of the lathe work before quenching from the finished product size / mm 1# 2.0-2.4 3.0-3.6 2.2 2# 2.25-2.5 2.9-3.45 2.2 3# 2.1-2.2 3.0-3.4 2.2 4# 1.9-2.3 3.2-3.7 2.2 5# 2.12-2.45 3.24-3.80 2.2 6# 2.01-2.20 2.95-3.40 2.2 7# 2.0-2.10 2.8-3.30 2.2 8# 2.05-2.32 2.96-3.60 2.2 9# 1.96-2.10 3.0-3.65 2.2 10# 2.2-2.3 3.4-3.95 2.2
[0033] Table 2. Table of dimensional changes of the outer ring during secondary quenching using the quenching die of the present utility model
[0034] Outer ring serial number Allowance of the outer diameter of the wide end face after quenching from the finished product size / mm Allowance of the outer diameter of the narrow end face after quenching from the finished product size / mm Allowance of the outer diameter size of the lathe work before quenching from the finished product size / mm 1# 2.04-2.20 2.10-2.21 2.2 2# 2.10-2.20 2.2 -2.34 2.2 3# 2.07-2.13 2.06-2.13 2.2 4# 2.34-2.46 2.40-2.50 2.2 5# 2.12-2.21 2.0-2.10 2.2 6# 2.10-2.24 2.05-2.12 2.2 7# 2.0-2.16 2.05-2.12 2.2 8# 2.02-2.20 2.10-2.21 2.2 9# 1.96-2.02 2.14-2.23 2.2 10# 2.16-2.32 2.12-2.23 2.2
[0035] By using two kinds of dies to conduct secondary quenching and tempering size verification on 10 outer rings with an outer diameter size of 820 mm respectively. Taking the No. 1 part of each group of tests as an example, the original die is used to quench the ring. Before quenching, the turning outer diameter allowance of the ring is 2.2 mm. After quenching, the outer diameter allowance of the wide end face of the No. 1 part is 2.0 - 2.4 mm, that is, the shrinkage and expansion is -0.2~0.2 mm (-0.2 means the size shrinks by 0.2 mm, 0.2 means the size expands by 0.2 mm, and the range endpoints are the high and low points of the size change at different circumferential positions, the same below). After quenching, the outer diameter allowance of the narrow end face of the No. 1 part is 3.0 - 3.6 mm, that is, the shrinkage and expansion is 0.8~1.4 mm; when using the improved die of the present application to quench the ring, before quenching, the turning outer diameter allowance of the ring is 2.2 mm. After quenching, the outer diameter allowance of the wide end face of the No. 1 part is 2.04 - 2.20 mm, that is, the shrinkage and expansion is -1.6~0 mm. After quenching, the outer diameter allowance of the narrow end face of the No. 1 part is 2.10 - 2.21 mm, that is, the shrinkage and expansion is -0.1~0.01 mm.
[0036] It is obtained that by changing the base size (C size) of the large diameter end of the die frustum part, when the outer ring is heated to austenitization and cooled, since the base size (C size) is 2.36 mm smaller than the narrow end face size of the outer ring, the outer ring is in a free quenching state without die surface restraint during cooling. Then, through the support of the straight part of the die (at D), the wide end face of the outer ring is shaped during quenching, so as to ensure the consistency of the shrinkage and expansion of the outer diameter sizes of the wide end face and the narrow end face. When the optimized die is used to quench the ring, the shrinkage and expansion of the outer diameter sizes of the wide end face and the narrow end face become smaller, which is more beneficial to the carburized layer depth and more uniform.
[0037] Use the straight part to support (at D) to prevent the outer ring from bursting upwards when it is pressed by the die, so that the product size cannot be controlled. At the same time, the base size (C size) of the die is shrunk by 1 - 4 mm to make the outer diameter size at the narrow end face shrink. Avoid the problem of different shrinkage and expansion caused by the conventional design of the original die, that is, due to the angle problem of the ring during carburizing, the outer diameter at the narrow end face has position penetration, and the outer diameter carburizing at the wide end face cannot penetrate due to the width problem, resulting in different shrinkage and expansion.
[0038] It should be noted that the parts not described in detail in the present invention are prior art.
[0039] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.
[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.
[0041] In the present utility model, unless otherwise clearly specified and limited, terms such as "mounted", "connected", "connected to", "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0042] In the present utility model, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0043] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.
[0044] The above examples are only the best embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and there are many variations. All variations that can be directly derived or associated with the contents disclosed by a person skilled in the art should be considered as the protection scope of the present invention.
Claims
1. A quenching die for the outer ring of a conical carburizing steel bearing, characterized in that: It includes a frustum cone body for supporting the inner surface of the bearing outer ring, and a cylindrical platform body integrated with the frustum cone body is arranged at the bottom of the frustum cone body; the frustum cone body includes a straight platform part and a frustum part, the straight platform part is a cylindrical structure, the straight platform part is connected to the small-diameter end of the frustum part, the outer diameter of the straight platform part is the same as the outer diameter of the small-diameter end of the frustum part, the outer diameter of the frustum part gradually increases from top to bottom, the large-diameter end of the frustum part is connected to the cylindrical platform body, and the outer diameter of the cylindrical platform body is greater than the outer diameter of the large-diameter end of the frustum part; a plurality of upper oil flow grooves are arranged on the outer ring surface of the frustum cone body, a plurality of lower oil flow grooves are arranged on the upper surface of the cylindrical platform body, the plurality of upper oil flow grooves and the plurality of lower oil flow grooves correspond one by one, and each group of corresponding upper oil flow grooves and lower oil flow grooves communicate with each other.
2. A quenching die for a conical carburizing steel bearing outer ring according to claim 1, characterized in that: The bottom of each group of corresponding upper oil flow grooves is perpendicular to the bottom of the lower oil flow grooves.
3. A quenching die for the outer ring of a conical carburizing steel bearing according to claim 1, characterized in that: The plurality of upper oil flow grooves on the outer ring surface of the frustum cone body are distributed along the generatrix direction, the plurality of lower oil flow grooves on the upper surface of the cylindrical platform body are radially distributed, and the groove widths of the upper oil flow grooves and the lower oil flow grooves are the same.
4. A quenching die for the outer ring of a conical carburizing steel bearing according to any one of claims 1 to 3, characterized in that: The plurality of upper oil flow grooves are vertically grooved from top to bottom, and the bottoms of the plurality of upper oil flow grooves are parallel to the axis of the frustum cone body; the plurality of lower oil flow grooves are horizontally grooved, and the bottoms of the plurality of lower oil flow grooves are perpendicular to the axis of the cylindrical platform body.
5. A quenching die for the outer ring of a conical carburizing steel bearing according to claim 1, characterized in that: A circle of oil flow ring grooves is arranged at the connection between the frustum cone body and the cylindrical platform body, and the oil flow ring grooves communicate with all the upper oil flow grooves and the lower oil flow grooves.
6. A quenching die for the outer ring of a conical carburized steel bearing according to claim 1, characterized in that: The frustum cone body and the cylindrical platform body are coaxially arranged, and the frustum cone body and the cylindrical platform body are provided with a hollow cavity that communicates with each other.
7. A quenching die for the outer ring of a conical carburized steel bearing according to claim 1, characterized in that: The outer diameter of the straight platform part of the frustum cone body is 0.5-1 mm larger than the inner diameter of the wide end face of the bearing outer ring.
8. A quenching die for the outer ring of a conical carburizing steel bearing according to claim 1, characterized in that: The outer diameter of the large-diameter end of the frustum part of the frustum cone body is 1-4 mm smaller than the inner diameter of the narrow end face of the bearing outer ring.