Quality control and process optimization method for sealing groove of outer ring of deep groove ball bearing

Abstract

The invention provides a deep groove ball bearing outer ring sealing groove quality control and process optimization method, and the method comprises the steps: optimizing a measurement tool: replacing a traditional pistol meter with an inner diameter meter, and flexibly adjusting the measurement height in a manner of fastening a measurement point through a nut; the multi-procedure machining capacity of a numerical control lathe is utilized, and sealing groove turning machining is synchronously completed in the same procedure for machining the plane, the outer diameter and the channel of the outer ring of the bearing; heat treatment process optimization: firstly, carrying out a system test, collecting taper change data in a heat treatment process, and establishing an associated database so as to realize taper pre-judgment and differential processing; during heat treatment, the workpiece is placed with the mark facing upwards; and optimizing the detection frequency: performing whole-process inspection. According to the quality control and process optimization method for the sealing groove of the outer ring of the deep groove ball bearing, accurate control over the quality of the sealing groove is achieved through comprehensive optimization of the measuring tool, the machining procedure, the heat treatment process and the detection frequency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of processing thin series deep groove ball bearings, in particular to a deep groove ball bearing outer ring sealing groove quality control and process optimization method. BACKGROUND

[0002] The size accuracy, ovality and wall thickness uniformity of the sealing groove of the thin-walled deep groove ball bearing outer ring such as (6000, 61800, 61900 series) directly affect the sealing performance, assembly accuracy and service life of the bearing. At present, there are many deficiencies in the processing and quality control of the sealing groove in the industry: The measurement method is backward: the traditional method is to measure the sealing groove size with a pistol gauge, which is highly dependent on the skill level and experience of the operator. Due to the deformation of the sealing groove after heat treatment and the increase of friction, the workpiece cannot be rotated arbitrarily during the measurement process, which is prone to measurement blind spots, and it is difficult to accurately collect ovality data, resulting in large measurement errors; Poor process coordination: the sealing groove is usually machined separately from the plane, outer diameter and groove.

[0003] Heat treatment deformation: after quenching and tempering treatment of the bearing outer ring, the outer diameter is prone to taper deformation, which will be transmitted to the sealing groove at the same time, resulting in inconsistent size of the sealing groove on both sides, which seriously affects the sealing effect; the existing technology lacks effective compensation measures for this deformation, and cannot guarantee the uniformity of the sealing groove size after heat treatment. Therefore, there is an urgent need for a quality control and process optimization method that can solve the above problems.

[0004] Therefore, there is an urgent need for a quality control and process optimization method that can solve the above problems. SUMMARY

[0005] The purpose of the present application is to provide a deep groove ball bearing outer ring sealing groove quality control and process optimization method, which realizes accurate control of the quality of the sealing groove through the optimization of the measurement tool, machining process, heat treatment process and detection frequency.

[0006] To achieve the above purpose, the present application provides a deep groove ball bearing outer ring sealing groove quality control and process optimization method, which optimizes the measurement tool, machining process, heat treatment process and detection frequency, specifically including: Measurement tool optimization: replace the traditional pistol gauge with an inside diameter gauge, and adjust the measurement height flexibly by tightening the measurement point with a nut; Process optimization: use the multi-process machining capability of the numerical control lathe to complete the sealing groove turning in the same process as the machining of the bearing outer ring plane, outer diameter and groove; Heat treatment process optimization: first, carry out system test, collect the taper change data in heat treatment process, establish the correlation database, and then realize the taper prediction and differential processing; after the numerical control machining is completed, use chalk to make annular mark at the outer diameter of the outer ring with small initial size of the sealing groove; Optimization of detection frequency: whole-process inspection.

[0007] Preferably, the heat treatment process optimization comprises: Test selects the bearing outer ring of GCr15 material with the specification of Φ80*20*Φ65, takes the quenching temperature, the tempering temperature and the holding time as variables, carries out 30 parallel tests for each group of variables, records the outer diameter taper and the sealing groove taper data, and analyzes the outer diameter taper-sealing groove taper change rule; The test proves that the upper end expansion of the ring is larger than the lower end under normal circumstances, according to the rule, different initial sizes are designed for the two sides of the sealing groove during numerical control machining, and the accurate compensation of heat treatment deformation is realized.

[0008] Preferably, the width of the annular mark is 2-3mm.

[0009] Preferably, the whole-process inspection is carried out once every 10 pieces of machining.

[0010] Therefore, the deep groove ball bearing outer ring sealing groove quality control and process optimization method has the following technical effects: The measurement accuracy is significantly improved: the inner diameter table nut fastening type measurement can rotate the workpiece at will, the size and ovality data collection is comprehensive, the error is less than or equal to 0.01mm, and the influence of human factors is reduced; The process reliability is improved: the integrated machining completely eliminates the sequence leakage phenomenon, and the position precision of the sealing groove and other structures is improved; The heat treatment deformation is effectively compensated: through the test prediction taper+differential processing+directional placement, the size difference of the two sides of the sealing groove after heat treatment is less than 0.05mm, and the taper deformation problem is solved; The product qualification rate is improved: combined with the scientific measurement frequency, the sealing groove quality qualification rate in batch production is improved from more than 70% of the traditional process to more than 90%, which is suitable for large-scale production.

[0011] This method is not only applied to optimize the sealing groove, but also suitable for improving other surfaces, and has high universality DETAILED DESCRIPTION

[0012] The technical solutions of the present application are further described below through examples.

[0013] Unless otherwise defined, the technical terms or scientific terms used in the present application should be understood as the usual meanings understood by those skilled in the art to which the present application belongs.

[0014] Example 1 (New Process Route) Car 1 Plane: Machining reference surface: The outer ring of the deep groove ball bearing is machined into a flat surface to ensure that the flatness meets the design requirements and to provide a stable reference for subsequent machining.

[0015] Turning the outer diameter: Using the machined plane as a reference, turn half the outer diameter of the outer ring with the same tool, control the dimensional accuracy within a reasonable range, and ensure the perpendicularity of the outer diameter to the plane.

[0016] Machining contour sealing groove Machining method: CNC machining is adopted, and standard cutting tools are used for cutting, which reduces the difficulty and cost of tooling and ensures the stability and consistency of machining.

[0017] Size control: Based on the design requirements, add a dimension in a specific direction to the machining dimensions to ensure the accuracy of the predicted sealing groove dimensions.

[0018] Placement requirements: Arrange the outer rings of this machined surface neatly with this surface facing down to facilitate subsequent processes and avoid damage to the parts due to improper placement.

[0019] External chamfering: Chamfering is performed on the outer edges of the machined parts to remove burrs, prevent scratches and other quality problems in subsequent processes or during use, and improve the appearance quality of the parts.

[0020] Rough machining of the outer groove: The outer groove of the outer ring is rough machined to initially form the shape and size of the outer groove, preparing for the subsequent finish machining of the outer groove.

[0021] Car 2 Plane: Machining reference surface: Turn another plane of the outer ring (turn plane 2) to ensure that the parallelism between this plane and the already machined plane meets the requirements, and to provide another reliable reference for subsequent machining.

[0022] Outer diameter machining: Using the newly machined plane as a reference, continue machining the remaining 1 / 2 of the outer diameter of the outer ring to make the entire outer diameter dimension uniform and consistent, meeting the dimensional requirements of the machining stage.

[0023] Machining contour sealing groove Machining method: CNC machining is also used, and standard cutting tools are used for cutting.

[0024] Size control: Based on the design requirements, subtract the dimension in a specific direction from the machining dimension to ensure that the size of the sealing groove accurately matches the predicted requirements.

[0025] Placement and error prevention: Place the outer ring of the part with the machined surface facing upwards, and make a clear mark on the part to prevent placement errors in subsequent processes that may affect the machining quality.

[0026] Processing the outer chamfer: Chamfer the outer edge on this side, corresponding to the chamfer in step 1, to ensure that the overall chamfer of the outer ring is uniform and smooth.

[0027] Fine machining of the outer groove: Complete the fine machining of the outer groove to ensure that the shape and size of the outer groove meet the process requirements.

[0028] Quenching: Furnace preparation: Arrange the machined outer rings of the deep groove ball bearings neatly on the quenching fixture with the markings facing upwards, ensuring that they are placed stably and with reasonable spacing to avoid deformation caused by collisions or uneven heating during the heating process.

[0029] Quenching treatment: Place the tooling with the parts in a quenching furnace, heat it to a quenching temperature range of 830-860 degrees Celsius, and hold it for 50 minutes to allow the parts to reach a suitable austenitizing state, preparing them for subsequent quenching transformation.

[0030] Quenching and Cooling: After the required heating time is reached, the parts are quickly removed from the quenching furnace and quenched and cooled according to the specified cooling method and cooling medium to give the parts high hardness and good wear resistance. During the cooling process, the cooling rate and cooling uniformity must be strictly controlled to prevent defects such as quenching cracks from forming on the parts.

[0031] Tempering: Furnace preparation: Place the quenched deep groove ball bearing outer rings neatly on the tempering fixture with the markings facing upwards to ensure stable placement of the parts so that they are heated evenly during the tempering process.

[0032] Tempering: Place the tooling with the parts assembled into a tempering furnace, heat it to a tempering temperature of 180 degrees Celsius, and hold it for 4–6 hours. Tempering eliminates the internal stress generated during quenching, stabilizes the dimensions of the parts, and adjusts their hardness and toughness to achieve optimal overall mechanical properties.

[0033] Cooling after removal from the furnace: After the required tempering time has been reached, remove the parts from the tempering furnace and allow them to cool naturally to room temperature in the air. During the cooling process, care should be taken to avoid impacts or rapid cooling of the parts to prevent the generation of new internal stress or deformation.

[0034] Example 2 (Original Process) CNC turning preliminary machining (a) First turning Reference surface turning: Using a CNC lathe, the first plane of the outer ring of the deep groove ball bearing (plane 1) is precisely turned, and the flatness and surface roughness are strictly controlled to ensure that it provides a stable and reliable reference for subsequent machining.

[0035] External diameter turning: Using the machined plane as the positioning datum, CNC turn half of the outer diameter of the outer ring. According to the design requirements, set the cutting parameters reasonably to ensure that the outer diameter dimension has an appropriate machining allowance during the machining stage, while ensuring that the cylindricity of the outer diameter meets the standard.

[0036] Inner diameter machining: Next, the inner and outer diameters are machined to precisely control the inner diameter dimensions and ensure its coaxiality with the outer diameter, providing a good foundation for the assembly and use of the bearing.

[0037] Chamfering: Chamfering is performed on the inner and outer edges of the outer ring (inner (outer) chamfering) to remove burrs, prevent scratches and other quality problems during subsequent processes or use, and improve the appearance quality of the parts. The chamfering dimensions must be strictly implemented according to the design requirements to ensure uniformity.

[0038] Rough turning of the outer groove: The outer groove is rough turned on a CNC lathe to initially form the shape and dimensional outline of the outer groove. According to the part material and design requirements, appropriate tools and cutting parameters are selected to ensure that the surface roughness of the outer groove after rough turning meets the requirements of subsequent machining, while leaving sufficient machining allowance for fine turning of the outer groove.

[0039] (ii) Secondary turning Another reference surface turning: Turn the outer ring over and turn the second plane again using a CNC lathe (turn plane 2) to ensure that the parallelism between this plane and the first plane is within the specified range, providing another accurate reference for subsequent machining.

[0040] Continue machining of outer diameter: Using the newly machined plane as a reference, continue CNC turning of the remaining 1 / 2 outer diameter of the outer ring to make the entire outer diameter dimension reach the uniform standard after rough machining, ensuring the dimensional accuracy and cylindricity of the outer diameter.

[0041] Secondary chamfering: The inner and outer edges of the outer ring on this side are chamfered again (inner (outer) chamfering) to ensure that the chamfer dimensions on both sides are consistent, further eliminating burrs and sharp edges, and improving the safety and aesthetics of the parts.

[0042] Fine turning of the outer groove: The outer groove is finely turned using a CNC lathe. By precisely adjusting the tool path and cutting parameters, the dimensional accuracy, shape accuracy, and surface roughness of the outer groove are precisely machined. This ensures that the dimensions of the outer groove strictly meet the design requirements, and the surface is smooth and flat, providing a guarantee for subsequent machining of the sealing groove and the normal operation of the bearing.

[0043] II. Specialized machining for sealing grooves (a) Preparation for machining the sealing groove After completing the CNC turning process described above, transfer the outer ring of the deep groove ball bearing to a dedicated machine tool and check its operating status and the installation of the non-standard forming inserts. Ensure that all parameters of the dedicated machine tool are set correctly, and that the non-standard forming inserts are securely installed and have sharp cutting edges to guarantee the machining quality of the sealing groove.

[0044] (ii) Turning over to process the sealing groove Initial flipping process: Place the outer ring in a specific orientation on the fixture of a dedicated machine tool, start the machine tool, and use a non-standard forming insert to turn the first sealing groove. During the machining process, closely monitor the machine tool's operating status and cutting conditions, and adjust the cutting parameters in a timely manner according to the actual machining results to ensure that the dimensional accuracy, shape accuracy, and surface roughness of the sealing groove meet the design requirements.

[0045] Secondary turning: After machining the first sealing groove, turn the outer ring over and machine the second sealing groove using a non-standard forming insert, following the same machining methods and requirements. During the machining process, strict quality control is essential to ensure dimensional consistency and symmetry between the two sealing grooves.

[0046] III. Heat Treatment Process (a) Quenching treatment Furnace preparation: Randomly place the outer rings of the deep groove ball bearings with the sealing grooves completed on the quenching fixture. Pay attention to placing them stably and evenly to avoid squeezing and colliding between the parts, and ensure that each part is heated evenly during the heating process.

[0047] Quenching heating: Place the quenching fixture with the parts assembled into the quenching furnace and heat it at a quenching temperature of 830-860 degrees Celsius. Strictly control the heating rate and temperature to ensure that the parts reach the quenching temperature within the specified time, ensuring that the internal structure of the parts can be fully transformed, thus laying the foundation for obtaining a good quenching effect.

[0048] Quenching and Cooling: After the parts reach the quenching temperature and are held at that temperature for 50 minutes, they should be quickly removed from the quenching furnace and quenched and cooled according to the specified cooling method and cooling medium. The cooling rate must be strictly controlled during the cooling process to prevent defects such as quenching cracks, while ensuring that the parts achieve high hardness and good wear resistance.

[0049] (ii) Tempering treatment Furnace preparation: After quenching, remove the parts from the cooling medium and place them randomly on the tempering fixture. The placement method is similar to that during quenching to ensure that the parts are heated evenly during tempering.

[0050] Tempering Heating: Place the tempering fixture with the parts in the tempering furnace and heat it at the set tempering temperature of 180 degrees Celsius. The selection of tempering temperature and time must be precisely controlled according to the material and performance requirements of the parts. Tempering treatment eliminates the internal stress generated in the parts during quenching, stabilizes the dimensions of the parts, and adjusts the hardness and toughness of the parts to achieve the best comprehensive mechanical properties.

[0051] Tempering and Cooling: After tempering for 4 to 6 hours, remove the parts from the tempering furnace and allow them to cool naturally to room temperature in the air. During the cooling process, care should be taken to avoid the parts being affected by external factors, such as collisions or rapid cooling, to prevent the generation of new internal stress or deformation of the parts.

[0052] Therefore, the present invention adopts the above-mentioned method for quality control and process optimization of the outer ring sealing groove of a deep groove ball bearing to achieve comprehensive control of the sealing groove quality.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for quality control and process optimization of the outer ring sealing groove of a deep groove ball bearing, characterized in that, Optimizations were made in measuring tools, processing steps, heat treatment processes, and testing frequency, specifically including: Measurement tool optimization: An inside gauge is used instead of a traditional pistol gauge, and the measurement height is flexibly adjusted by tightening the nut at the measurement point; Machining process optimization: Utilizing the multi-process machining capabilities of CNC lathes, the sealing groove machining is completed simultaneously in the same process of machining the bearing outer ring plane, outer diameter, and groove; Heat treatment process optimization: First, conduct system tests to collect data on taper changes during heat treatment and establish a correlation database to achieve taper prediction and differentiated processing; after CNC machining is completed, make a ring mark with chalk on the outer diameter of the outer ring where the initial size of the sealing groove is small; during heat treatment, place the workpiece with the mark facing upwards; Optimize inspection frequency: conduct full-process inspections.

2. The method for quality control and process optimization of the outer ring sealing groove of a deep groove ball bearing according to claim 1, characterized in that, Heat treatment process optimization, including: The experiment selected a bearing outer ring made of GCr15 material with specifications of Φ80×20×Φ65. With quenching temperature, tempering temperature and holding time as variables, 30 parallel experiments were carried out for each group of variables. The data of outer diameter taper and sealing groove taper were recorded, and the variation law of outer diameter taper and sealing groove taper was analyzed. Experiments have shown that, under normal circumstances, the upper end of the ring expands more when it is laid flat than the lower end. Based on this rule, different initial dimensions are designed for the two sides of the sealing groove during CNC machining to achieve precise compensation for heat treatment deformation.

3. The method for quality control and process optimization of the outer ring sealing groove of a deep groove ball bearing according to claim 1, characterized in that, The width of the ring mark is 2-3mm.

4. The method for quality control and process optimization of the outer ring sealing groove of a deep groove ball bearing according to claim 1, characterized in that, During the entire process inspection, an inspection is conducted once every 10 pieces are processed.