Commercial vehicle gear anti-abrasion tooth grinding process machining method and system

Abstract

The invention relates to the technical field of vehicle gear grinding machining, and discloses a commercial vehicle gear grinding process machining method and system.The method comprises the steps that firstly, gear part structure parameters are obtained, the specifications of a gear hobbing clamp and a full-cutting hob are determined, and basic machining configuration parameters are obtained; deriving heat treatment machining and after-heat turning three-jaw specifications on the basis of the parameters to form heat machining and clamping parameters; further determining specifications and parameters of a gear grinding wheel, calculating tooth thickness allowance by combining common normal dimensions after heating and after grinding, and obtaining grinding feeding parameters and the number of machining stages; determining machining beat parameters by combining axial feeding speed and auxiliary action time, deducing grinding wheel circular machining parameters according to the length of the grinding wheel and the normal modulus of the part, and calculating grinding wheel use parameters according to the outer diameter of the grinding wheel and the total dressing amount; and finally, all the parameters are integrated to complete anti-attrition gear grinding machining. The technical problem that the gear anti-attrition gear grinding machining efficiency is low is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of vehicle gear grinding technology, specifically to a method and system for reducing the wear of commercial vehicle gears through gear grinding. Background Technology

[0002] With the rapid development of the machinery industry, gear grinding has become one of the core processes in high-end gear processing due to its ability to significantly improve gear precision and transmission performance. It is widely used, especially in high-end equipment fields such as AT / AMT transmissions, new energy high-speed transmission systems, high-speed rail, and aerospace. Commercial vehicle gears, due to their load-bearing requirements, typically have a module and tooth width more than twice that of passenger vehicle gears. This presents commercial vehicle gear grinding with more stringent efficiency and cost challenges.

[0003] The gear grinding industry currently faces multiple challenges. Firstly, market competition is intensifying: international high-end gear manufacturers (such as ZF-Foton and Eaton-Cummins) are accelerating their localization efforts, and the localization process is progressing steadily, directly weakening the original cost advantages of domestic commercial vehicle manufacturers, leading to increasingly fierce market competition. Secondly, efficiency is mismatched with industry development trends: gear grinding has clearly become the mainstream processing technology for future gear products, but there is a significant gap in grinding efficiency between commercial vehicles and passenger vehicles. Under current technology, the grinding time for commercial vehicle gears is generally maintained at 2-3 minutes per piece, while the grinding time for passenger vehicle gears can be controlled at 1-2 minutes per piece. The low grinding efficiency of commercial vehicles has become a key bottleneck restricting the industry's upgrading.

[0004] From a technological standpoint, current gear grinding speeds at domestic commercial vehicle manufacturers have reached 80 m / s, with a feed rate of 0.2 mm / r, employing a three-pass grinding process. While these technical indicators have reached advanced levels in the domestic and international commercial vehicle industry, they still lag significantly behind passenger vehicle gear grinding technology. Currently, the industry lacks a commercial vehicle gear grinding process with comparable efficiency to passenger vehicle grinding. The commonly used three-pass grinding process for commercial vehicles not only has long processing times but also suffers from high grinding wheel consumption, directly leading to a significant increase in manufacturing costs for commercial vehicle gear grinding. Statistics show that current commercial vehicle gear grinding costs are more than double those of passenger vehicles, while processing efficiency is only half that of passenger vehicles. This significantly increases production costs for domestic commercial vehicle companies and weakens their market competitiveness. Therefore, developing a high-efficiency, low-cost commercial vehicle gear grinding process has become an urgent technical problem to be solved by the industry. Summary of the Invention

[0005] In order to overcome the defects of the existing technology, the purpose of this invention is to provide a method and system for grinding gears with reduced wear in commercial vehicles, so as to solve the technical problem of how to improve the processing efficiency of grinding gears with reduced wear.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a grinding process for reducing the wear of gears in commercial vehicles, comprising: Obtain the structural parameters of commercial vehicle gear parts, and determine the specifications of the gear hobbing fixture and the full-cut hob based on the structural parameters of the parts to obtain the basic machining configuration parameters; Based on the part information corresponding to the basic machining configuration parameters, the heat treatment machining parameters and the three-jaw chuck specifications after heat treatment are determined to obtain the heat treatment and subsequent clamping parameters. Based on the part parameters corresponding to the hot working and subsequent clamping parameters, the specifications and parameters of the grinding wheel are determined to obtain the grinding wheel processing configuration parameters. Based on the grinding wheel machining configuration parameters and the common normal dimensions of the part after heating and after grinding, the tooth thickness allowance is calculated to determine the number of grinding stages and the normal feed rate, thus obtaining the grinding feed parameters; Based on the grinding feed parameters and the number of grinding stages, the grinding stroke time is calculated by combining the axial feed speed, and the grinding cycle time is determined by superimposing the auxiliary action time, thus obtaining the processing cycle parameters. The effective length of the grinding wheel is calculated based on the grinding wheel length and the normal module of the part in the grinding wheel processing configuration parameters. The number of parts ground per grinding cycle is determined by combining the effective length of the grinding wheel, and the grinding wheel cycle processing parameters are obtained. Based on the maximum and minimum outer diameters of the grinding wheel and the total amount of dressing per cycle in the grinding wheel processing configuration parameters, combined with the number of grinding parts per cycle, the theoretical life of the grinding wheel and the estimated number of workpieces that can be processed are calculated to obtain the grinding wheel usage parameters; Based on the basic machining configuration parameters, hot working and subsequent clamping parameters, grinding wheel machining configuration parameters, grinding feed parameters, machining cycle parameters, grinding wheel cycle machining parameters, and grinding wheel usage parameters, the grinding reduction of commercial vehicle gears is carried out.

[0007] Preferably, the specific method for determining the specifications of the hobbing fixture includes selecting the corresponding hobbing expansion sleeve, hobbing support, and pressure cap according to different part structures. The dimensions of the hobbing pressure cap and support are both smaller than the root circle diameter of the hobbing part. The diameter of the hobbing expansion sleeve is smaller than the inner hole diameter of the part, and the expansion sleeve is prevented from rotating during processing by fixing the expansion sleeve anti-rotation screw.

[0008] Preferably, the specific method for determining the specifications of the full-cut hob includes dividing the machining allowance reserved for hobbing and grinding according to the gear module size and the outer diameter specification of the part. Specifically, the machining allowance reserved for hobbing and grinding includes: when the diameter is less than 200 and the module is 0-4mm, the machining allowance reserved for the tooth thickness on one side is 0.08-0.085; when the diameter is less than 200 and the module is more than 4mm, the machining allowance reserved for the tooth thickness on one side is 0.09-0.095; when the diameter is more than 200 and the module is 0-4mm, the machining allowance reserved for the tooth thickness on one side is 0.085-0.09; and when the diameter is more than 200 and the module is more than 4mm, the machining allowance reserved for the tooth thickness on one side is 0.095-0.10.

[0009] Preferably, the specific method for determining the heat treatment processing parameters includes carburizing first, then oil quenching, and finally tempering; wherein the materials used in the heat treatment process include 8620 material or 20CrMnTi material, wherein the cooling oil selected for 8620 material is G oil, and the cooling oil selected for 20CrMnTi material is 355 oil and the strong carburizing potential is controlled within 1.1%; the parts are placed in the following manner during the heat treatment process: parts with a diameter less than 200 are placed in a series, and parts with a diameter greater than 200 are placed flat.

[0010] Preferably, the specific process for determining the specifications and parameters of the grinding wheel includes the following: The external dimensions of the grinding wheel are determined according to the model of the gear grinding machine and the specifications of the grinding wheel cutter holder. The external dimensions include the outer diameter * length * bore diameter. The normal module, normal pressure angle, number of heads, and direction of rotation of the grinding wheel are determined based on the parameters of the parts and the rollers.

[0011] Furthermore, the number of grinding wheel heads is selected to be a number not divisible by the number of teeth on the workpiece; the normal pressure angle of the grinding wheel is equal to the pressure angle of the roller. The formula for calculating the normal module of the grinding wheel is as follows:

[0012]

[0013] in, The normal module of the workpiece; The normal pressure angle of the workpiece; This refers to the number of grinding wheel heads. The normal module of the grinding wheel; The normal pressure angle of the grinding wheel; The roller pressure angle; The direction of rotation of the grinding wheel is determined based on the helix angle β of the workpiece.

[0014] Preferably, the specific process for determining the number of grinding stages and the normal feed rate is as follows: Calculate the allowance of the common normal of the blank The expression is as follows:

[0015] In the formula, This refers to the common normal length of the gear after heat treatment. The target common normal length of the gear after grinding; Calculate the tooth thickness allowance of the blank based on the allowance of the common normal of the blank.

[0016]

[0017]

[0018]

[0019] In the formula, The normal pressure angle of the workpiece; This is the common normal margin; This is the allowance for tooth thickness; The number of grinding stages and the single normal feed rate are determined based on the tooth thickness allowance, as expressed below: when In general, three-blade grinding is used;

[0020]

[0021]

[0022] when At this time, two-blade grinding can be used;

[0023]

[0024] In the formula, This is the feed rate for rough grinding; This is the feed rate for semi-finishing. This is the feed rate for fine grinding; The radial feed rate is converted to the radial single feed rate, as expressed below:

[0025] in, This refers to the radial single feed rate; This is the normal feed rate per cycle.

[0026] Preferably, the specific process for determining the grinding cycle time is as follows: Based on the number of grinding stages and the axial feed rate of each stage, the grinding stroke time can be calculated. The machining cycle time needs to be further increased by adding the machine tool material change time, gear finding and inspection time, and other auxiliary action time. The specific calculation method is as follows: When the grinding stage consists of 3 passes, the expression is as follows:

[0027]

[0028] When the grinding stage consists of 2 passes, the expression is as follows:

[0029] The cycle time of grinding is expressed as follows:

[0030] in, The grinding tool holder travel is in mm; To extend the cutting range beyond the specified travel distance, mm; For workpiece teeth mm ; The Z-axis feed rate during the rough grinding stage is in mm / min; The Z-axis feed rate during the semi-finishing stage is in mm / min; The Z-axis feed rate during the finishing grinding stage is in mm / min.

[0031] Preferably, the specific process for determining the number of parts ground per cycle of the grinding wheel, the theoretical life of the grinding wheel, and the estimated number of workpieces that can be machined includes: The effective length of the grinding wheel can be calculated using the following expression:

[0032] in:

[0033] In the formula, The tooth pitch; The normal module of the workpiece; This refers to the length of the grinding wheel; The effective grinding wheel length; The number of pieces ground per cycle is determined based on the calculated effective length of the grinding wheel. When the grinding stage consists of 3 passes, the expression for the number of pieces ground per cycle is as follows:

[0034] When the grinding stage consists of 2 passes, the expression for the number of pieces ground per cycle of the grinding wheel is as follows:

[0035] In the formula, This represents the continuous Y-axis displacement length during the rough grinding stage. This refers to the continuous Y-axis displacement length during the semi-finishing stage. This refers to the continuous Y-axis displacement length during the fine grinding stage. The length of the horizontal displacement along the Y-axis; The effective grinding wheel length; Based on the maximum and minimum outer diameters of the grinding wheel and the total dressing volume per cycle, the theoretical number of dressing cycles can be calculated. Multiplying this by the number of parts processed per cycle yields the theoretical service life of the grinding wheel, which can then be used to estimate the number of workpieces the grinding wheel can process. The calculation method is as follows: Theoretical number of dressing cycles for grinding wheels:

[0036] Calculation of grinding wheel theoretical life:

[0037] Estimated number of workpieces that can be processed:

[0038] In the formula, This is the maximum outer diameter of the grinding wheel; This is the minimum outer diameter of the grinding wheel; This refers to the total amount of dressing required per grinding wheel cycle; This represents the number of parts processed per cycle of the grinding wheel.

[0039] Secondly, the present invention also provides a gear grinding process system for reducing wear on commercial vehicle gears, comprising: The basic configuration module is used to obtain the structural parameters of commercial vehicle gear parts, and to determine the specifications of the hobbing fixture and the full-cut hob based on the structural parameters of the parts to obtain the basic machining configuration parameters. The post-heat clamping module is used to determine the heat treatment processing parameters and the three-jaw specifications of the post-heat machining machine based on the part information corresponding to the basic processing configuration parameters, and to obtain the heat processing and subsequent clamping parameters. The grinding wheel configuration module is used to determine the specifications and parameters of the grinding wheel based on the part parameters corresponding to the hot working and subsequent clamping parameters, and to obtain the grinding wheel processing configuration parameters. The feed determination module is used to calculate the tooth thickness allowance, determine the number of grinding stages and the normal feed amount based on the grinding wheel machining configuration parameters and the common normal dimensions of the part after heating and after grinding, so as to obtain the grinding feed parameters. The cycle time calculation module is used to calculate the grinding stroke time based on the grinding feed parameters and the number of grinding stages, combined with the axial feed speed, and to determine the grinding cycle time by superimposing the auxiliary action time, thus obtaining the processing cycle time parameters. The cycle machining module is used to calculate the effective length of the grinding wheel based on the grinding wheel length and the normal module of the part in the grinding wheel machining configuration parameters, and to determine the number of parts ground per cycle of the grinding wheel in combination with the effective length of the grinding wheel, so as to obtain the grinding wheel cycle machining parameters; The life prediction module is used to calculate the theoretical life of the grinding wheel and the estimated number of workpieces that can be processed based on the maximum and minimum outer diameter of the grinding wheel and the total amount of dressing per cycle in the grinding wheel processing configuration parameters, combined with the number of grinding parts per cycle of the grinding wheel, so as to obtain the grinding wheel usage parameters. The machining execution module is used to perform grinding of commercial vehicle gears with reduced wear based on basic machining configuration parameters, hot working and subsequent clamping parameters, grinding wheel machining configuration parameters, grinding feed parameters, machining cycle parameters, grinding wheel cycle machining parameters, and grinding wheel usage parameters.

[0040] Compared with the prior art, the present invention has the following beneficial technical effects: This invention provides a grinding process for reducing the grinding allowance of gears in commercial vehicles. By controlling the precision of the incoming blank before grinding, the solution to reduce the grinding allowance has been verified and promoted on various gear grinding machines. This solves the problem of long grinding time in existing commercial vehicle gear grinding processes, while significantly improving the effective utilization rate of grinding wheels. The grinding wheel life is increased by two times compared to before, and the processing cost meets the requirements of mass production, resulting in a significant improvement in transmission cost control.

[0041] Furthermore, by accurately determining the specifications of the hobbing fixture and full-cut hob by obtaining the structural parameters of the parts, the rework and machining interference problems caused by fixture selection deviations and insufficient tool specification adaptation in traditional processes are avoided. By clarifying the hobbing allowance standards for different specifications of parts, it is ensured that no additional adjustment of allowance is required in subsequent grinding. Based on the correlation of basic machining configuration parameters, the heat treatment processing parameters and the specifications of the three-jaw machining after heat treatment are determined, achieving seamless connection of the processing flow. By selecting suitable cooling oil for different materials and determining the placement method according to the part diameter, heat treatment deformation is effectively controlled, reducing the additional processes caused by deformation correction in post-heat processing.

[0042] Furthermore, the tooth thickness allowance is accurately calculated by the common normal dimensions after heating and grinding, and the grinding mode is divided into 2-cut or 3-cut according to the single-sided tooth thickness allowance threshold. The normal feed amount of each stage is reasonably allocated and converted into radial feed amount. The grinding stroke time is accurately calculated based on the grinding parameters and axial feed speed, and the machining cycle time is determined by superimposing the auxiliary action time. This makes the production rhythm controllable, reduces the waiting gap between processes, and improves the turnover efficiency of the production line.

[0043] Furthermore, the effective length of the grinding wheel is calculated by the normal module of the part, and the number of parts to be ground per cycle is determined by the grinding wheel displacement in each grinding stage. This fully taps the effective grinding potential of the grinding wheel and reduces its ineffective wear. The theoretical life and estimated number of workpieces to be processed are calculated by the maximum and minimum outer diameter of the grinding wheel and the total dressing amount per cycle. This enables the planning of grinding wheel replacement and dressing, avoids production interruptions caused by sudden grinding wheel failure, and ensures the continuity of processing. Attached Figure Description

[0044] Figure 1 This is a flowchart of the gear grinding process for reducing wear on commercial vehicle gears in this embodiment of the invention. Figure 2 This is a flowchart illustrating the confirmation process for the number of grinding stages and the normal feed rate in an embodiment of the present invention. Figure 3 This is a schematic diagram of the grinding wheel movement strategy in an embodiment of the present invention; Figure 4 This is a schematic diagram of the gear grinding process for reducing wear on commercial vehicle gears in an embodiment of the present invention. In the diagram: 1. Basic configuration module; 2. Post-heat clamping module; 3. Grinding wheel configuration module; 4. Feed determination module; 5. Cycle time calculation module; 6. Cyclic machining module; 7. Life prediction module; 8. Machining execution module. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0047] The purpose of this invention is to provide a method and system for grinding gears to reduce wear in commercial vehicles, so as to solve the technical problem of how to improve the processing efficiency of grinding gears to reduce wear.

[0048] The present invention will now be described in further detail with reference to the accompanying drawings: Example 1 See Figure 1 In one embodiment of the present invention, a grinding process for reducing the wear of gears in commercial vehicles is provided, characterized by comprising: Step 1: Obtain the structural parameters of the commercial vehicle gear parts, and determine the specifications of the hobbing fixture and the full-cut hob based on the structural parameters of the parts to obtain the basic machining configuration parameters; Specifically, different hobbing expansion sleeves, hobbing supports, and pressure caps are selected according to different part structures. It should be noted that the hobbing pressure cap and support should be smaller than the root circle diameter of the hobbing part. Generally, the support and pressure cap should be selected as close as possible to the root circle. This size can effectively prevent part deformation caused by the support being too far from the machining area during the machining process. The diameter of the expansion sleeve should be selected as small as possible (within 0.2mm of the inner diameter of the part) to prevent the part from rotating during the machining process. Attention should also be paid to fixing the anti-rotation screw of the expansion sleeve to prevent the expansion sleeve from rotating during the machining process, which would cause the workpiece to lose machining accuracy.

[0049] Specifically, based on the gear module size and the outer diameter of the parts, the machining allowance for gear hobbing of different specifications is divided into the following three specifications: for gears with a diameter of less than 200mm and a module of 0-4mm, the machining allowance for gear grinding is 0.08mm on one side; for gears with a module of 4mm or more, the machining allowance for gear grinding is 0.095mm on one side; for gears with a diameter of more than 200mm and a module of 0-4mm, the machining allowance for gear grinding is 0.085mm on one side; and for gears with a module of 4mm or more, the machining allowance for gear grinding is 0.010mm on one side.

[0050] Step 2: Based on the part information corresponding to the basic machining configuration parameters, determine the heat treatment machining parameters and the three-jaw chuck specifications after heat treatment to obtain the heat treatment and subsequent clamping parameters; Specifically, determine the cooling oil used in heat treatment, the placement plan, and the strong carburizing potential data.

[0051] The heat treatment process involves carburizing, followed by oil quenching and tempering. To control the deformation of the heat-treated parts, different cooling oils are required for different materials. For example, 8620 material requires G oil, which cools faster, while 20CrMnTi material requires 355 oil, which cools slower, and the strong carburizing potential needs to be controlled within 1.1%. Depending on the structure of the parts, the placement method also varies. Parts with a diameter less than 200 mm are placed in a series, while parts with a diameter greater than 200 mm are placed flat for heat treatment.

[0052] In this embodiment, the three-jaw chuck specification is selected according to the different diameters of the parts.

[0053] Step 3: Based on the part parameters corresponding to the hot working and subsequent clamping parameters, determine the grinding wheel specifications and parameters to obtain the grinding wheel processing configuration parameters; Specifically, the specifications and parameters for grinding wheels are as follows: First, based on the model of the gear grinding machine and the specifications of the grinding wheel holder, determine the external dimensions of the grinding wheel that can be used. It is generally expressed as: outer diameter D * length L * bore diameter d; Secondly, the grinding wheel can be determined by the part parameters and the roller parameters, generally expressed as: module M / pressure angle α / number of heads G / direction of rotation. The specific parameter confirmation and calculation methods are as follows: The number of grinding wheel heads can be selected from 1 to 7, with priority given to the number of heads that is not divisible by the number of teeth Z of the workpiece. At the same time, to ensure processing efficiency, grinding wheels with more heads should be selected, and it is generally recommended to use grinding wheels with 3 to 5 heads. The normal pressure angle of the grinding wheel is equal to that of the roller pressure angle. ; The formula for calculating the normal module of the grinding wheel is as follows:

[0054]

[0055] in, The normal module of the workpiece; The normal pressure angle of the workpiece; This refers to the number of grinding wheel heads. The normal module of the grinding wheel; The normal pressure angle of the grinding wheel; The roller pressure angle; The grinding wheel rotation direction must meet the rotation direction restriction requirements of the gear grinding machine. Generally, right-hand grinding wheels are used by default. If the machine tool allows the use of left-hand grinding wheels, the appropriate grinding wheel rotation direction can be selected according to the helix angle β and rotation direction of the workpiece.

[0056] Step 4: Based on the grinding wheel machining configuration parameters and the common normal dimensions of the part after heating and after grinding, calculate the tooth thickness allowance, determine the number of grinding stages and the normal feed, and obtain the grinding feed parameters; Specifically, according to Figure 2 As shown, the specific process is as follows: Calculate the allowance of the common normal of the blank The expression is as follows:

[0057] In the formula, This refers to the common normal length of the gear after heat treatment. The target common normal length of the gear after grinding; Calculate the tooth thickness allowance of the blank based on the allowance of the common normal of the blank.

[0058]

[0059]

[0060]

[0061] In the formula, The normal pressure angle of the workpiece; This is the common normal margin; This is the allowance for tooth thickness; The number of grinding stages and the single normal feed rate are determined based on the tooth thickness allowance, as expressed below: when In general, three-blade grinding is used;

[0062]

[0063]

[0064] when At this time, two-blade grinding can be used;

[0065]

[0066] In the formula, This is the feed rate for rough grinding; This is the feed rate for semi-finishing. This is the feed rate for fine grinding; The radial feed rate is converted to the radial single feed rate, as expressed below:

[0067] in, This refers to the radial single feed rate; This is the normal feed rate per cycle.

[0068] Step 5: Based on the grinding feed parameters and the number of grinding stages, calculate the grinding stroke time in combination with the axial feed speed, and superimpose the auxiliary action time to determine the grinding cycle time and obtain the processing cycle time parameters; Specifically, the grinding cycle time is determined. Based on the number of grinding stages and the axial feed rate of each stage, the grinding stroke time can be calculated. The machining cycle time needs to be further increased by adding the machine tool material change time, gear finding and inspection time, and other auxiliary action time. The specific calculation method is as follows: When the grinding stage consists of 3 passes, the expression is as follows:

[0069]

[0070] When the grinding stage consists of 2 passes, the expression is as follows:

[0071] The cycle time of grinding is expressed as follows:

[0072] in, The grinding tool holder travel is in mm; To extend the cutting range beyond the specified travel distance, mm; For workpiece teeth mm ; The Z-axis feed rate during the rough grinding stage is in mm / min; The Z-axis feed rate during the semi-finishing stage is in mm / min; The Z-axis feed rate during the finishing grinding stage is in mm / min.

[0073] Step 6: Calculate the effective length of the grinding wheel based on the grinding wheel length and the normal module of the part in the grinding wheel processing configuration parameters, and determine the number of parts ground per grinding cycle by combining the effective length of the grinding wheel, thus obtaining the grinding wheel cycle processing parameters; Specifically, because the tooth grooves at the beginning and end of the spiral lines at both ends of the grinding wheel are incomplete, in order to ensure the grinding tooth profile, it is necessary to avoid the incomplete teeth at both ends of the grinding wheel, that is... The actual length of the grinding wheel used in the grinding process is calculated as follows:

[0074] in:

[0075] In the formula, The tooth pitch; The normal module of the workpiece; This refers to the length of the grinding wheel; The effective grinding wheel length; During grinding, to ensure the quality of the tooth surface, a continuous flow of new grinding wheel surface is required for machining. This means that as the tool holder feeds along the Z-axis, the grinding wheel moves axially along the Y-axis in tandem, resulting in a certain distance of movement at each grinding stage. During the fine grinding stage, the Y-axis will undergo a relatively large lateral movement. Meanwhile, to ensure the utilization rate of the grinding wheel, the grinding wheel will undergo negative transverse movement along the Y-axis when grinding the next workpiece. Grinding wheel axial movement strategy, such as Figure 3 As shown. The total number of workpieces P that can be processed throughout the entire grinding wheel cycle, from the start to the end of the effective grinding wheel length, is the number of workpieces ground per cycle. The calculation formula is as follows: When the grinding stage consists of 3 passes, the expression for the number of workpieces ground per cycle is as follows:

[0076] When the grinding stage consists of 2 passes, the expression for the number of pieces ground per cycle of the grinding wheel is as follows:

[0077] In the formula, This represents the continuous Y-axis displacement length during the rough grinding stage. This refers to the continuous Y-axis displacement length during the semi-finishing stage. This refers to the continuous Y-axis displacement length during the fine grinding stage. The length of the horizontal displacement along the Y-axis; This refers to the effective grinding wheel length.

[0078] Step 7: Based on the maximum and minimum outer diameters of the grinding wheel and the total amount of dressing per cycle in the grinding wheel processing configuration parameters, and combined with the number of parts ground per cycle, calculate the theoretical life of the grinding wheel and the estimated number of workpieces that can be processed, and obtain the grinding wheel usage parameters; Specifically, based on the maximum and minimum outer diameters of the grinding wheel and the total amount of dressing per cycle, the theoretical number of dressing cycles can be calculated. Multiplying this by the number of parts processed per cycle yields the theoretical service life of the grinding wheel, which can then be used to estimate the number of workpieces the wheel can process. The calculation method is as follows: Theoretical number of dressing cycles for grinding wheels:

[0079] Calculation of grinding wheel theoretical life:

[0080] Estimated number of workpieces that can be processed:

[0081] In the formula, This is the maximum outer diameter of the grinding wheel; This is the minimum outer diameter of the grinding wheel; This refers to the total amount of dressing required per grinding wheel cycle; This represents the number of parts processed per cycle of the grinding wheel.

[0082] Step 8: Based on the basic machining configuration parameters, hot working and subsequent clamping parameters, grinding wheel machining configuration parameters, grinding feed parameters, machining cycle parameters, grinding wheel cycle machining parameters, and grinding wheel usage parameters, perform grinding reduction of commercial vehicle gears.

[0083] In this embodiment, by improving the hobbing fixture in the pre-heat hobbing process, the rigidity of the fixture is increased, thereby enabling the tooth accuracy of the hobbing part to reach level 7 after machining.

[0084] Using a full-cut hob (a hob tool that simultaneously processes the tooth tip circle and the tooth) designed for different products in the pre-heat hobbing process significantly improves the consistency between the outer circle of the part and the pitch circle of the gear.

[0085] During the heat treatment stage, the deformation of the parts during heat treatment is significantly reduced by selecting the type of heat treatment cooling oil, the method of placing the parts, and controlling the carbon potential.

[0086] In the hot-cutting stage, the use of a pre-hot cut hob ensures that the pitch circle and outer diameter of the part are on the same datum. By clamping the outer diameter to machine the inner hole, the pitch circle and inner hole are made to be on the same datum. This method allows the pitch circle of the part and the inner hole for gear positioning to remain on the same datum during subsequent gear grinding, greatly increasing the accuracy of the gear grinding blank.

[0087] During the gear grinding stage, for different structural parts, the corresponding grinding wheel specifications and grit size are selected, and the processing parameters are changed, which greatly improves the efficiency of part processing and reduces grinding wheel consumption.

[0088] Example 2 according to Figure 4 As shown, this embodiment also provides a gear grinding process system for reducing wear on commercial vehicle gears, including: Basic configuration module 1 is used to obtain the structural parameters of commercial vehicle gear parts, and to determine the specifications of the hobbing fixture and the full-cut hob based on the structural parameters of the parts to obtain the basic machining configuration parameters; The post-heat clamping module 2 is used to determine the heat treatment processing parameters and the post-heat machining three-jaw specifications based on the part information corresponding to the basic processing configuration parameters, and to obtain the heat processing and subsequent clamping parameters. Grinding wheel configuration module 3 is used to determine the specifications and parameters of the grinding wheel based on the part parameters corresponding to the hot working and subsequent clamping parameters, and obtain the grinding wheel processing configuration parameters. The feed determination module 4 is used to calculate the tooth thickness allowance, determine the number of grinding stages and the normal feed amount based on the grinding wheel machining configuration parameters and the common normal dimensions of the part after heating and after grinding, so as to obtain the grinding feed parameters. Cycle calculation module 5 is used to calculate the grinding stroke time based on the grinding feed parameters and the number of grinding stages, combined with the axial feed speed, and superimpose the auxiliary action time to determine the grinding cycle time and obtain the processing cycle time parameters. The cycle processing module 6 is used to calculate the effective length of the grinding wheel based on the grinding wheel length and the normal module of the part in the grinding wheel processing configuration parameters, and to determine the number of parts ground per cycle of the grinding wheel in combination with the effective length of the grinding wheel, so as to obtain the grinding wheel cycle processing parameters; The life prediction module 7 is used to calculate the theoretical life of the grinding wheel and the estimated number of workpieces that can be processed based on the maximum and minimum outer diameter of the grinding wheel and the total amount of dressing per cycle in the grinding wheel processing configuration parameters, combined with the number of grinding parts per cycle of the grinding wheel, to obtain the grinding wheel usage parameters. The machining execution module 8 is used to perform grinding of commercial vehicle gears with reduced wear based on basic machining configuration parameters, hot working and subsequent clamping parameters, grinding wheel machining configuration parameters, grinding feed parameters, machining cycle parameters, grinding wheel cycle machining parameters and grinding wheel usage parameters.

[0089] In summary, the gear grinding process and system for reducing the grinding allowance of commercial vehicle gears provided in this embodiment have been verified and promoted on a gear grinding machine by controlling the accuracy of the incoming blank before grinding and reducing the grinding allowance. This solves the problem of long processing time for existing commercial vehicle gear grinding, while significantly improving the effective utilization rate of the grinding wheel, doubling the grinding wheel life, and meeting the requirements of mass production in terms of processing cost. It has been promoted in batches as a key product and has significantly improved the cost control of transmissions.

[0090] This invention transforms the existing gear grinding process from three stages—rough grinding, semi-finish grinding, and finish grinding—by controlling pre-heat hobbing, heat treatment deformation, and post-heat turning. This increases the precision of the incoming gear blank, reducing the single-sided tooth thickness allowance from the existing 0.15mm to 0.08mm. The gear grinding process is divided into two stages: rough grinding and finish grinding, and a reasonable grinding allowance allocation scheme is provided for each stage. The rough grinding stage ensures maximum efficiency in removing machining allowance, while the finish grinding stage ensures that the gear tooth precision meets design requirements. Experiments have summarized the appropriate grinding wheel specifications and grit sizes for different parts. This invention innovatively proposes reducing the machining allowance of the incoming blank through pre-process control, and through experiments, summarizes the allowance allocation, grinding wheel selection, and cutting parameter schemes for different products, thereby achieving a process scheme that reduces gear grinding time and grinding wheel consumption.

[0091] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A grinding process for reducing wear on commercial vehicle gears, characterized in that, include: Obtain the structural parameters of commercial vehicle gear parts, and determine the specifications of the gear hobbing fixture and the full-cut hob based on the structural parameters of the parts to obtain the basic machining configuration parameters; Based on the part information corresponding to the basic machining configuration parameters, the heat treatment machining parameters and the three-jaw chuck specifications after heat treatment are determined to obtain the heat treatment and subsequent clamping parameters. Based on the part parameters corresponding to the hot working and subsequent clamping parameters, the specifications and parameters of the grinding wheel are determined to obtain the grinding wheel machining configuration parameters. Based on the grinding wheel machining configuration parameters and the common normal dimensions of the part after heating and after grinding, the tooth thickness allowance is calculated to determine the number of grinding stages and the normal feed rate, thus obtaining the grinding feed parameters; Based on the grinding feed parameters and the number of grinding stages, the grinding stroke time is calculated by combining the axial feed speed, and the grinding cycle time is determined by superimposing the auxiliary action time, thus obtaining the processing cycle parameters. The effective length of the grinding wheel is calculated based on the grinding wheel length and the normal module of the part in the grinding wheel processing configuration parameters. The number of parts ground per grinding cycle is determined by combining the effective length of the grinding wheel, and the grinding wheel cycle processing parameters are obtained. Based on the maximum and minimum outer diameters of the grinding wheel and the total amount of dressing per cycle in the grinding wheel processing configuration parameters, combined with the number of grinding parts per cycle, the theoretical life of the grinding wheel and the estimated number of workpieces that can be processed are calculated to obtain the grinding wheel usage parameters; Based on the basic machining configuration parameters, hot working and subsequent clamping parameters, grinding wheel machining configuration parameters, grinding feed parameters, machining cycle parameters, grinding wheel cycle machining parameters, and grinding wheel usage parameters, the grinding reduction of commercial vehicle gears is carried out.

2. The gear grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific method for determining the specifications of the gear hobbing fixture includes selecting the corresponding gear hobbing expansion sleeve, gear hobbing support, and pressure cap according to different part structures. The dimensions of the gear hobbing pressure cap and support are both smaller than the root circle diameter of the gear hobbing part. The diameter of the gear hobbing expansion sleeve is smaller than the inner hole diameter of the part, and the expansion sleeve is prevented from rotating during the machining process by fixing the expansion sleeve anti-rotation screw.

3. The gear grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific method for determining the specifications of a full-cut hob includes dividing the machining allowance for hobbing and grinding based on the gear module size and the outer diameter of the part. Specifically, the machining allowance for hobbing and grinding includes: 0.08-0.085 for a single-sided tooth thickness when the diameter is below 200mm and the module is 0-4mm; 0.09-0.095 for a single-sided tooth thickness when the diameter is below 200mm and the module is above 4mm; 0.085-0.09 for a single-sided tooth thickness when the diameter is above 200mm and the module is 0-4mm; and 0.095-0.10 for a single-sided tooth thickness when the diameter is above 200mm and the module is above 4mm.

4. The gear grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific methods for determining heat treatment parameters include carburizing first, then oil quenching, and finally tempering. The materials used in the heat treatment process include 8620 or 20CrMnTi. For 8620, G oil is selected as the cooling oil, and for 20CrMnTi, 355 oil is selected, with the strong carburizing potential controlled within 1.1%. During heat treatment, parts with a diameter less than 200 mm are placed in a series, while parts with a diameter greater than 200 mm are placed horizontally.

5. The gear grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific process for determining the specifications and parameters of a gear grinding wheel includes the following: The external dimensions of the grinding wheel are determined according to the model of the gear grinding machine and the specifications of the grinding wheel cutter holder. The external dimensions include the outer diameter * length * bore diameter. The normal module, normal pressure angle, number of heads, and direction of rotation of the grinding wheel are determined based on the parameters of the parts and the rollers.

6. The gear grinding process for reducing wear on commercial vehicle gears according to claim 5, characterized in that, The number of heads of the grinding wheel is selected to be a number that is not divisible by the number of teeth on the workpiece; the normal pressure angle of the grinding wheel is equal to the pressure angle of the roller. The formula for calculating the normal module of the grinding wheel is as follows: in, The normal module of the workpiece; The normal pressure angle of the workpiece; This refers to the number of grinding wheel heads. The normal module of the grinding wheel; The normal pressure angle of the grinding wheel; The roller pressure angle; The direction of rotation of the grinding wheel is determined based on the helix angle β of the workpiece.

7. The gear grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific process for determining the number of grinding stages and the normal feed rate is as follows: Calculate the allowance of the common normal of the blank The expression is as follows: In the formula, This refers to the common normal length of the gear after heat treatment. The target common normal length of the gear after grinding; Calculate the tooth thickness allowance of the blank based on the allowance of the common normal of the blank. In the formula, The normal pressure angle of the workpiece; This is the common normal margin; This is the allowance for tooth thickness; The number of grinding stages and the single normal feed rate are determined based on the tooth thickness allowance, as expressed below: when In general, three-blade grinding is used; when At this time, two-blade grinding can be used; In the formula, This is the feed rate for rough grinding; This is the feed rate for semi-finishing. This is the feed rate for fine grinding; The radial feed rate is converted to the radial single feed rate, as expressed below: in, This refers to the radial single feed rate; This is the normal feed rate per cycle.

8. The grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific process for determining the cycle time of grinding is as follows: Based on the number of grinding stages and the axial feed rate of each stage, the grinding stroke time can be calculated. The machining cycle time needs to be further increased by adding the machine tool material change time, gear finding and inspection time, and other auxiliary action time. The specific calculation method is as follows: When the grinding stage consists of 3 passes, the expression is as follows: When the grinding stage consists of 2 passes, the expression is as follows: The cycle time of grinding is expressed as follows: in, The grinding tool holder travel is in mm; To extend the cutting range beyond the specified travel distance, mm; For workpiece teeth mm ; The Z-axis feed rate during the rough grinding stage is in mm / min; The Z-axis feed rate during the semi-finishing stage is in mm / min; The Z-axis feed rate during the finishing grinding stage is in mm / min.

9. The gear grinding process for reducing wear on commercial vehicle gears according to claim 1, characterized in that, The specific process for determining the number of parts ground per cycle, the theoretical life of the grinding wheel, and the estimated number of workpieces that can be machined includes: The effective length of the grinding wheel can be calculated using the following expression: in: In the formula, The tooth pitch; The normal module of the workpiece; This refers to the length of the grinding wheel; Effective grinding wheel length; The number of pieces ground per cycle is determined based on the calculated effective length of the grinding wheel. When there are 3 grinding stages, the expression for the number of pieces ground per cycle is as follows: When the grinding stage consists of 2 passes, the expression for the number of pieces ground per cycle of the grinding wheel is as follows: In the formula, This represents the continuous Y-axis displacement length during the rough grinding stage. This refers to the continuous Y-axis displacement length during the semi-finishing stage. This refers to the continuous Y-axis displacement length during the fine grinding stage. The horizontal displacement length along the Y-axis; Effective grinding wheel length; Based on the maximum and minimum outer diameters of the grinding wheel and the total dressing volume per cycle, the theoretical number of dressing cycles can be calculated. Multiplying this by the number of parts processed per cycle yields the theoretical service life of the grinding wheel, which can then be used to estimate the number of workpieces the grinding wheel can process. The calculation method is as follows: Theoretical number of dressing cycles for grinding wheels: Theoretical life calculation of grinding wheel: Estimated number of workpieces that can be processed: In the formula, This is the maximum outer diameter of the grinding wheel; This is the minimum outer diameter of the grinding wheel; This refers to the total amount of dressing required per grinding wheel cycle; This represents the number of parts processed per cycle of the grinding wheel.

10. A gear grinding process system for reducing wear on commercial vehicle gears, characterized in that, include: The basic configuration module is used to obtain the structural parameters of commercial vehicle gear parts, and to determine the specifications of the gear hobbing fixture and the full-cut hob based on the structural parameters of the parts to obtain the basic machining configuration parameters. The post-heat clamping module is used to determine the heat treatment processing parameters and the three-jaw specifications of the post-heat machining machine based on the part information corresponding to the basic machining configuration parameters, and to obtain the heat processing and subsequent clamping parameters. The grinding wheel configuration module is used to determine the specifications and parameters of the grinding wheel based on the part parameters corresponding to the hot working and subsequent clamping parameters, and to obtain the grinding wheel processing configuration parameters. The feed determination module is used to calculate the tooth thickness allowance, determine the number of grinding stages and the normal feed amount based on the grinding wheel machining configuration parameters and the common normal dimensions of the part after heating and after grinding, so as to obtain the grinding feed parameters. The cycle time calculation module is used to calculate the grinding stroke time based on the grinding feed parameters and the number of grinding stages, combined with the axial feed speed, and to determine the grinding cycle time by superimposing the auxiliary action time, thus obtaining the processing cycle time parameters. The cycle machining module is used to calculate the effective length of the grinding wheel based on the grinding wheel length and the normal module of the part in the grinding wheel machining configuration parameters, and to determine the number of parts ground per cycle of the grinding wheel in combination with the effective length of the grinding wheel, so as to obtain the grinding wheel cycle machining parameters; The life prediction module is used to calculate the theoretical life of the grinding wheel and the estimated number of workpieces that can be processed based on the maximum and minimum outer diameter of the grinding wheel and the total amount of dressing per cycle in the grinding wheel processing configuration parameters, combined with the number of grinding parts per cycle of the grinding wheel, so as to obtain the grinding wheel usage parameters. The machining execution module is used to perform grinding of commercial vehicle gears with reduced wear based on basic machining configuration parameters, hot working and subsequent clamping parameters, grinding wheel machining configuration parameters, grinding feed parameters, machining cycle parameters, grinding wheel cycle machining parameters, and grinding wheel usage parameters.

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