Multi-grinding-wheel collaborative grinding process method of non-standard thread milling cutter and grinding equipment of non-standard thread milling cutter

Abstract

The invention relates to a multi-grinding-wheel collaborative grinding process method of a non-standard thread milling cutter and grinding equipment of the non-standard thread milling cutter. The multi-grinding-wheel collaborative grinding process method comprises the steps that an outer circle grinding path line of the non-standard thread milling cutter is determined; according to the determined outer circle grinding path line, the bar is machined so as to remove the redundant part of the bar, and slotting treatment is conducted on the bar so as to form a thread tooth groove; rough machining is conducted on the thread tooth groove through a first non-standard grinding wheel, so that the initial shape of the non-standard thread milling cutter is formed; the first non-standard grinding wheel is of an asymmetric structure and is provided with a first inclined face and a second inclined face in the thickness direction of the first non-standard grinding wheel, a first preset included angle is formed between the first inclined face and the radial line direction of the first non-standard grinding wheel, and a second preset included angle is formed between the second inclined face and the radial line direction of the first non-standard grinding wheel. The first preset included angle is larger than the second preset included angle; the thread tooth groove is subjected to finish machining through a second non-standard grinding wheel, so that the final shape of the non-standard thread milling cutter is formed; the second non-standard grinding wheel is of a symmetrical structure.

Description

Technical Field

[0001] This application relates to the field of cutting and machining technology, and in particular to a multi-wheel synergistic grinding process and grinding equipment for non-standard thread milling cutters. Background Technology

[0002] In the field of machining, carbide cutters (especially non-standard carbide thread end mills) are widely used in the machining of various complex parts (such as hydraulic sealing connectors) due to their high hardness, high wear resistance, and good strength. In the field of hydraulic sealing connectors, to meet specific sealing and connection requirements, the threads of the connectors are mostly designed by the manufacturers as non-standard threads. These non-standard threads have complex and diverse profiles and large thread radii. To achieve efficient machining of such threads, a thread end mill matching the thread profile is usually selected for one-time machining. This not only results in high productivity but also ensures the interchangeability of workpiece shape and size, guaranteeing the quality and performance stability of the connector. However, due to the complex profile and numerous grooves of these cutters, the grinding difficulty is correspondingly increased significantly.

[0003] For grinding forming tools with special profiles, especially for this non-standard thread end mill, the complexity of the process is self-evident due to the requirement of a large number of teeth and a reasonable clearance angle. In the grinding process of this non-standard thread end mill, the grinding of the tool profile is a technically extremely difficult step. Related technologies using a single grinding wheel have limitations, restricting processing efficiency and quality. Summary of the Invention

[0004] Based on this, a multi-wheel collaborative grinding process and grinding equipment for non-standard thread milling cutters are provided, which improves grinding efficiency and quality.

[0005] A multi-wheel collaborative grinding process for non-standard thread milling cutters includes:

[0006] Determine the external grinding path of the non-standard thread milling cutter;

[0007] According to the determined external cylindrical grinding path, the bar stock is processed to remove the excess part of the bar stock and to perform grooving to form thread grooves.

[0008] The thread grooves are rough-machined using a first non-standard grinding wheel to form the initial shape of the non-standard thread milling cutter; wherein, the first non-standard grinding wheel has an asymmetrical structure, and the first non-standard grinding wheel has a first inclined surface and a second inclined surface along its thickness direction, the first inclined surface has a first preset angle α with the radial direction of the first non-standard grinding wheel, and the second inclined surface has a second preset angle b with the radial direction of the first non-standard grinding wheel, the first preset angle α being greater than the second preset angle b;

[0009] The thread grooves are finished by using a second non-standard grinding wheel to form the final shape of the non-standard thread milling cutter; wherein the second non-standard grinding wheel has a symmetrical structure.

[0010] In one embodiment, the thread grooves are rough-machined to form the initial shape of a non-standard thread milling cutter, including:

[0011] The first non-standard grinding wheel is used to rough machine the thread groove in a manner perpendicular to the thread groove to form the initial shape of the non-standard thread milling cutter.

[0012] In one embodiment, the threaded groove has a first threaded inclined surface and a second threaded inclined surface disposed opposite to each other;

[0013] Wherein, the first thread inclined surface is inclined at a first angle A1 relative to the groove depth direction of the thread tooth groove, and the second thread inclined surface is inclined at a second angle A2 relative to the groove depth direction of the thread tooth groove, wherein the first angle A1 is greater than the second angle A2.

[0014] In one embodiment, the removal of excess portion of the bar stock and the grooving process to form thread grooves have the following parameters:

[0015] The groove openings of the thread tooth grooves located on one side of the first thread inclined surface, the groove openings of the thread tooth grooves located on one side of the second thread inclined surface, and the bottom of the thread tooth grooves are all rounded.

[0016] The groove of the thread tooth located on one side of the first thread inclined surface and the groove of the thread tooth located on one side of the second thread inclined surface both have a first fillet R1, which is 0.3mm-0.5mm.

[0017] The bottom of the groove of the thread has a second fillet R2, which is 0.2mm-0.3mm.

[0018] The groove depth H of the thread tooth is 1.3mm-1.8mm;

[0019] The non-standard thread milling cutter has a peripheral clearance angle, which has a first clearance angle, a second clearance angle and a third clearance angle arranged sequentially along the circumference of the non-standard thread milling cutter. The first clearance angle is 8°-12°, the second clearance angle is 16°-20°, and the third clearance angle is 23°-30°.

[0020] The first angle is 22°-25°, and the second angle is 15°-18°.

[0021] In one embodiment, the thread grooves are rough-machined to form the initial shape of the non-standard thread milling cutter, which has the following parameters:

[0022] The first angle A1 is equal to the first preset included angle a, the second angle A2-10°=the second preset included angle b, and the tip width c of the non-standard thread milling cutter is less than 2R2.

[0023] In one embodiment, the thread grooves are finished using a second non-standard grinding wheel to form the final shape of the non-standard thread milling cutter, which has the following parameters:

[0024] The tip of the second non-standard grinding wheel has an angle r = R2 - 0.1, and the included angle d at the tip of the second non-standard grinding wheel is less than (A1 + A2) / 2.

[0025] In one embodiment, determining the external grinding path of the non-standard thread milling cutter includes:

[0026] Using computer-aided design software, the required thread profile of the bar stock is drawn in a coordinate system. The height difference of the profile peaks is obtained through a fitting algorithm, and then the outer diameter grinding path of the non-standard thread milling cutter is determined.

[0027] In one embodiment, the non-standard thread milling cutter is profile-ground from the shank side to the head side.

[0028] In one embodiment, the first non-standard grinding wheel and / or the second non-standard grinding wheel are made of cemented carbide material.

[0029] A multi-wheel collaborative grinding device for non-standard thread milling cutters includes:

[0030] The main body of the equipment is used to install the bar stock;

[0031] A grinding element is disposed on the equipment body. The grinding element is used to process the bar stock to remove excess parts of the bar stock and to perform grooving treatment on it to form thread grooves.

[0032] A first non-standard grinding wheel is disposed on the equipment body; the first non-standard grinding wheel has an asymmetrical structure, and has a first inclined surface and a second inclined surface along its thickness direction. The first inclined surface has a first preset angle α with respect to the radial direction of the first non-standard grinding wheel, and the second inclined surface has a second preset angle b with respect to the radial direction of the first non-standard grinding wheel. The first preset angle α is greater than the second preset angle b. The first non-standard grinding wheel is used to rough machine the thread groove to form the initial shape of the non-standard thread milling cutter.

[0033] A second non-standard grinding wheel is disposed on the equipment body; wherein, the second non-standard grinding wheel is used to finish the thread groove to form the final shape of the non-standard thread milling cutter; wherein, the second non-standard grinding wheel has a symmetrical structure.

[0034] The aforementioned multi-wheel collaborative grinding process and equipment for non-standard thread milling cutters first involves machining the bar stock to create thread grooves by determining the external cylindrical grinding path. Then, a first non-standard grinding wheel is used for roughing, and a second non-standard grinding wheel is used for finishing. This multi-wheel collaborative process avoids the need for a single grinding wheel to repeatedly adjust for different stages of machining, significantly shortening the machining time and substantially improving the machining efficiency of non-standard thread milling cutters.

[0035] The first non-standard grinding wheel has an asymmetrical structure with a first inclined surface and a second inclined surface along the thickness direction, and the first preset included angle α is greater than the second preset included angle b. This allows the different inclined surfaces to play different roles during rough machining of thread grooves, based on the complex profile of the thread, resulting in more precise material removal and an initial shape closer to the design requirements. The second non-standard grinding wheel has a symmetrical structure, ensuring uniform force distribution during finish machining, reducing vibration, and guaranteeing high precision in the shape and surface quality of the machined thread grooves, effectively improving the overall machining quality of the non-standard thread milling cutter.

[0036] By using multiple grinding wheels in tandem, the complex grinding process is broken down into two relatively simple and clear stages: roughing and finishing. These stages are completed by grinding wheels with different structural characteristics, reducing the overall processing difficulty and making the grinding of non-standard thread milling cutters more operable and stable. Attached Figure Description

[0037] Figure 1 This is a schematic flowchart of a multi-wheel collaborative grinding process for non-standard thread milling cutters, as shown in an exemplary embodiment.

[0038] Figure 2 This is a schematic diagram of a non-standard thread milling cutter in an exemplary embodiment.

[0039] Figure 3 This is a schematic diagram of a non-standard thread milling cutter in an exemplary embodiment.

[0040] Figure 4 This is a schematic diagram of a non-standard thread milling cutter and a first non-standard grinding wheel in an exemplary embodiment.

[0041] Figure 5 This is a schematic diagram of the structure of a threaded tooth groove in an exemplary embodiment.

[0042] Figure 6 This is a schematic diagram of the structure of a second non-standard grinding wheel in an exemplary embodiment.

[0043] Figure 7 This is a schematic diagram of grinding a second non-standard grinding wheel in an exemplary embodiment.

[0044] Figure 8 This is a schematic diagram of grinding a second non-standard grinding wheel in an exemplary embodiment.

[0045] Figure 9 This is a schematic diagram of grinding a second non-standard grinding wheel in an exemplary embodiment.

[0046] Figure label:

[0047] 1. First non-standard grinding wheel; 11. First inclined surface; 12. Second inclined surface; 2. Second non-standard grinding wheel; 3. Non-standard thread milling cutter; 31. Thread groove; 311. Right side allowance; 32. Tool holder; 33. Cutting edge. Detailed Implementation

[0048] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0049] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0050] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0053] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0054] The single-wheel grinding method has limitations, severely restricting machining efficiency and quality. For example, the profiles of non-standard thread milling cutters are extremely complex, with large elevation differences and narrow trough dimensions. When using general-purpose cylindrical or V-shaped grinding wheels for grinding, geometric interference easily occurs between the grinding wheel and the cutter profile. To avoid this problem, operators must frequently adjust the relative position and angle between the cutter and the grinding wheel. This not only leads to excessive setup time and reduced production efficiency but may also damage the grinding wheel due to improper operation, increasing production costs.

[0055] To address the issue of grinding wheel interference, the amount of material removed in a single grinding pass is severely limited. Grinding layer by layer using only fine grinding wheels is not only time-consuming, but also leads to wheel wear over time, causing dimensional inaccuracies and affecting tool accuracy. To machine complex contours completely, a layer-by-layer machining method is necessary, which significantly extends processing time and cannot meet the demands of large-scale production.

[0056] Due to the complex outer contour of this cutting tool, the final contour and the tool's back angle must be ground layer by layer using a fine grinding wheel. During this process, if the grinding wheel's grinding depth is inappropriate, abnormal load conditions can easily occur, potentially even causing the grinding wheel to burst. Simultaneously, during the grinding of the thread milling cutter's tooth grooves, the contact area between the grinding wheel and the tool is large, leading to a significant increase in machine tool load. If the grinding wheel's own load-bearing capacity is insufficient, it will break and fail. Once the grinding wheel is damaged and needs replacement, the new grinding wheel may not be the same size as the original, directly resulting in the tool being scrapped, causing substantial economic losses to the company.

[0057] This disclosure provides a multi-wheel collaborative grinding process for non-standard thread milling cutters, implemented using computer-aided design software and CNC tool grinding machines (grinding equipment). Through the coordinated operation of grinding wheels of different shapes, the grinding process of non-standard thread milling cutters is completed efficiently and accurately. Figure 1 As shown, the multi-wheel collaborative grinding process for non-standard thread milling cutters includes the following steps:

[0058] S100, Determine the external grinding path of the non-standard thread milling cutter.

[0059] In step S100, as Figures 2-9 As shown, using computer-aided design (CAD) software, the bar stock used for machining non-standard thread milling cutters is taken as the base object, and the required thread contour of the bar stock is accurately drawn within a pre-defined coordinate system. This coordinate system provides a unified reference framework for subsequent path calculations and machining operations, ensuring the accuracy and consistency of all data.

[0060] After the thread profile is drawn, a fitting algorithm is used to process it. The fitting algorithm can analyze and calculate the coordinate data of each point on the profile to obtain the height difference between the profile peaks. The height difference information is used to reflect the undulation of the thread profile.

[0061] Based on the calculated peak height difference of the profile, and considering the machining characteristics of the CNC tool grinder (grinding equipment) and the required motion trajectory of the grinding wheel, the outer diameter grinding path of the non-standard thread milling cutter is further determined. This path plans the movement trajectory of the grinding wheel along the outer diameter of the bar stock during the grinding process, ensuring that the grinding wheel can grind the bar stock according to the predetermined path, thereby gradually forming a thread profile that meets the design requirements. For example, when encountering areas with high peaks, the path guides the grinding wheel to adjust the grinding depth and speed appropriately to ensure the uniformity and accuracy of the grinding; while in the trough areas, the path ensures that the grinding wheel can accurately enter and complete the grinding operation, avoiding interference or under-grinding.

[0062] After determining the external cylindrical grinding path, it is imported into the control system of the CNC tool grinding machine. The control system of the CNC tool grinding machine can precisely control the movement trajectory of the grinding wheel and the grinding parameters based on the imported path information, thus making full preparations for subsequent grinding operations.

[0063] This disclosed multi-wheel synergistic grinding process for non-standard thread end mills determines the external cylindrical grinding path, laying a solid foundation for the entire grinding process. It effectively improves machining accuracy and efficiency while reducing machining errors and wheel wear caused by unreasonable path planning. Subsequent steps will be carried out based on this process to ultimately achieve high-quality grinding of the non-standard thread end mill.

[0064] S110. According to the determined external cylindrical grinding path, the bar stock is processed to remove the excess part of the bar stock and to perform grooving to form thread grooves.

[0065] In step S110, the bar stock is placed in the grinding equipment to ensure that the bar stock is fixed in position during the processing and will not shift due to the grinding force of the grinding wheel, thereby ensuring the processing accuracy.

[0066] The bar stock undergoes the first step of material removal using an external cylindrical grinding machine. Before removing the excess material through external cylindrical grinding, it is necessary to calculate the height difference between various parts of the bar stock. The height difference is calculated based on the previously determined external cylindrical grinding path. By analyzing the coordinate data of each point on the path and the initial dimensions of the bar stock, the height range of the excess material that needs to be removed is obtained.

[0067] When performing the first step of material removal using cylindrical grinding, the grinding parameters, such as the wheel speed and feed rate, are rationally set based on the calculated height difference. This efficiently removes most of the excess material from the bar stock and ensures that subsequent grinding wheels do not need to grind the outer contour of the tool. Grinding wheels are used for fine machining; if they were to perform rough grinding of the outer contour, it would not only accelerate the wear of the fine grinding wheel and reduce its service life, but also affect the final machining accuracy. In this embodiment, the material removal is performed first using cylindrical grinding, creating favorable conditions for subsequent fine machining.

[0068] The threaded groove has a first threaded inclined surface and a second threaded inclined surface arranged opposite to each other. The first threaded inclined surface is inclined at a first angle A1 relative to the groove depth direction of the threaded groove, and the second threaded inclined surface is inclined at a second angle A2 relative to the groove depth direction of the threaded groove. The first angle A1 is greater than the second angle A2. For example, the first angle A1 is 22°-25°, and the second angle A2 is 15°-18°, meeting the cutting performance and machining requirements of non-standard thread end mills in actual use. Different angle combinations can enable the tool to generate different cutting forces and cutting effects during the cutting process, thereby improving machining efficiency and quality.

[0069] In step S110, the excess portion of the bar stock is removed, and it is slotted to form thread grooves with the following parameters:

[0070] The groove openings of the thread tooth grooves located on the first thread inclined surface, the groove openings of the thread tooth grooves located on the second thread inclined surface, and the bottom of the thread tooth grooves are all rounded, which effectively reduces stress concentration of the tool during the cutting process, reduces the risk of tool chipping, and improves the tool's service life.

[0071] The grooves of the thread teeth on both the first and second inclined surfaces of the thread have a first fillet R1, which is 0.3mm-0.5mm. The bottom of the thread groove has a second fillet R2, which is 0.2mm-0.3mm. By properly setting these fillet radii, the cutting performance of the tool can be maintained while ensuring its strength.

[0072] The groove depth H of the thread tooth is 1.3mm-1.8mm, and the groove depth affects the cutting ability and machining accuracy of the tool. If the groove depth is too shallow, the tool may not be able to effectively remove material during the cutting process; if the groove depth is too deep, it will increase the manufacturing difficulty of the tool and reduce its strength.

[0073] Non-standard thread end mills have a peripheral clearance angle, which consists of a first clearance angle α, a second clearance angle β, and a third clearance angle γ arranged sequentially along the circumference of the non-standard thread end mill. The three clearance angles play different but complementary roles in terms of tool cutting performance and avoiding interference.

[0074] The primary function of the first clearance angle α is to impart cutting capability to the cutting tool. During cutting operations, the first clearance angle α reduces friction between the tool's flank face and the machined surface. Specifically, when the tool enters the workpiece, the flank face contacts the machined surface. If the first clearance angle α is not set appropriately—too large or too small—it will affect the cutting effect. If the first clearance angle α is too small, the friction between the flank face and the machined surface increases, leading to increased cutting force, accelerated tool wear, and even vibration, affecting the quality of the machined surface. Conversely, if the first clearance angle α is too large, although it reduces friction, it weakens the strength of the tool's flank face, making it prone to chipping during cutting.

[0075] For example, the first clearance angle α is 8°-12°. In actual machining, the angle value of the first clearance angle α is precisely determined based on parameters such as the material properties being machined, cutting speed, and feed rate. For example, when machining non-ferrous metals with lower hardness, the first clearance angle α can be appropriately larger, such as between 10°-12°, to reduce friction and improve the surface quality; while when machining steel materials with higher hardness, the first clearance angle α is relatively smaller, such as between 8°-10°, to ensure that the tool's flank face has sufficient strength. After determining the angle value, the tool's peripheral cutting edge is ground at the first clearance angle α position according to the set angle using grinding equipment to form a first clearance angle α that meets the requirements.

[0076] The primary function of the second clearance angle β and the third clearance angle γ is to avoid interference. During the cutting process of a milling cutter, due to the complexity of the tool structure and the diversity of workpiece shapes, the peripheral cutting edge of the tool may interfere with other parts of the workpiece or other structures of the tool itself when cutting different areas. By setting the second clearance angle β and the third clearance angle γ appropriately, these potential interference areas can be effectively avoided, ensuring that the tool can complete the cutting action smoothly. The angle values ​​of the second clearance angle β and the third clearance angle γ also need to be precisely determined based on the specific structure of the tool and the machining conditions. Specifically, the second clearance angle β is 16°-20°, and the third clearance angle γ is 23°-30°. By setting the angles of the second clearance angle β and the third clearance angle γ appropriately, the tool can avoid interference points during the cutting process, ensuring smooth machining.

[0077] During the machining process, grinding equipment is used to grind the corresponding positions of the tool's peripheral cutting edge according to the predetermined angle values ​​of the second clearance angle β and the third clearance angle γ. During grinding, it is necessary to control the grinding accuracy to ensure that the angles of the second clearance angle β and the third clearance angle γ are accurate and that the surface quality meets the requirements. At the same time, attention must be paid to the transition area between the three clearance angles to ensure a smooth transition and avoid sharp edges or abrupt changes, so as to prevent stress concentration during cutting and affecting the tool's service life.

[0078] CNC grinding equipment is used for machining. The movement trajectory and grinding parameters of the grinding wheel are controlled by programming to achieve precise grinding of the three back angles. During the grinding process, the grinding status, such as the wear condition of the grinding wheel and the magnitude of the grinding force, must be monitored in real time, and grinding parameters should be adjusted promptly to ensure grinding quality. For example, if increased grinding force is found due to grinding wheel wear, the feed rate should be appropriately reduced or the grinding wheel speed increased to ensure that the surface roughness meets the requirements.

[0079] After grinding, the three clearance angles need to be inspected. Inspection tools such as projectors and coordinate measuring machines can be used to comprehensively inspect the angles, positions, and surface quality of the clearance angles. If the inspection results do not meet the requirements, the tool needs to be reworked and the grinding process repeated until all parameters of the three clearance angles meet the design requirements.

[0080] Non-standard thread end mills feature a rake angle and a helix angle δ. The rake angle is set to 0°, and δ is an angle in the radial direction of the non-standard thread end mill, which enables the tool to have better stability and cutting force distribution during cutting. The helix angle δ is set to 8°. The presence of the helix angle δ allows chips to be discharged smoothly, reducing secondary wear on the tool from chips, and improving the quality of the machined surface. The non-standard thread end mill has 6 cutting edges.

[0081] During actual processing, operators need to adjust and operate the grinding equipment according to the parameters set above to ensure that the machining of each thread groove meets the design requirements. Simultaneously, the machining status must be monitored in real time, such as the wear of the grinding wheel and the machining dimensions of the bar stock, and machining parameters should be adjusted promptly to ensure machining quality and efficiency. Through the detailed parameter settings and machining operations described above, thread grooves that meet the design requirements can be accurately formed, laying the foundation for subsequent multi-wheel collaborative grinding processes.

[0082] S120. The thread groove is rough-machined using the first non-standard grinding wheel to form the initial shape of the non-standard thread milling cutter.

[0083] In step S120, the first non-standard grinding wheel used has an asymmetrical structure. Viewed from its thickness direction, the grinding wheel has a first inclined surface and a second inclined surface. A first preset angle α exists between the first inclined surface and the radial direction of the first non-standard grinding wheel, and a second preset angle b exists between the second inclined surface and the radial direction of the first non-standard grinding wheel. The first preset angle α is greater than the second preset angle b. The asymmetrical structure is designed to precisely remove excess material according to the design requirements of the non-standard thread milling cutter during subsequent rough machining of the thread grooves, forming an initial profile that conforms to specific angles and shapes.

[0084] For example, in the actual design process, based on the usage scenarios and processing requirements of non-standard thread milling cutters, calculations and simulations were performed to determine that the first preset included angle 'a' is 25° and the second preset included angle 'b' is 15°. This angle setting allows the grinding wheel to generate different grinding forces and effects on different inclined surfaces during the grinding process, thereby better shaping the thread grooves.

[0085] The prepared first non-standard grinding wheel is placed vertically (refer to...). Figure 4 The Z-axis (as shown) is used to rough-machine the thread grooves. In practice, the non-standard thread milling cutter bar stock is first securely fixed on the grinding table of the grinding equipment, ensuring it does not shift or vibrate during machining. Then, the position of the first non-standard grinding wheel is adjusted so that its axis is perpendicular to the extension direction of the thread grooves.

[0086] The grinding equipment is started, and the first non-standard grinding wheel rotates at a certain speed and is slowly fed towards the thread groove. During the feeding process, the first and second inclined surfaces of the first non-standard grinding wheel contact different parts of the thread groove. Through the relative movement between the grinding wheel and the bar stock, excess material on the thread groove is removed. Due to the asymmetrical structure of this forming grinding wheel, in the vertical insertion grinding process, it is not necessary to move the grinding wheel according to a specific required profile. Only by controlling the feed speed and depth, the excess material can be removed, gradually forming a "semi-finished" profile that is close to the final shape.

[0087] The rough machining of the thread grooves to form the initial shape of the non-standard thread milling cutter has the following parameters:

[0088] The first angle A1 is equal to the first preset included angle 'a', and the second angle A2 - 10° = the second preset included angle 'b'. As mentioned earlier, if the first preset included angle 'a' is 25°, then the first angle A1 is also 25°; if the second preset included angle 'b' is 15°, then the second angle A2 is 25°. The precise setting of these angle parameters is to ensure that the thread grooves of the non-standard thread milling cutter have the correct geometry and angles, thereby meeting its performance requirements in cutting operations.

[0089] The tip width c of a non-standard thread end mill should be less than 2R2. For example, if the second fillet radius R2 of the valley bottom of the thread groove is 0.25mm, then the tip width c of the non-standard thread end mill should be less than 0.5mm. Controlling the tip width c is to ensure that the non-standard thread end mill has good cutting performance and cutting stability during the cutting process, and to avoid problems such as excessive cutting force or vibration caused by an excessively wide tip.

[0090] During rough machining, it is necessary to monitor the machining status in real time, including the wear of the grinding wheel, the magnitude of the grinding force, and the quality of the machined surface. This data can be acquired in real time through sensors and monitoring systems installed on the grinding equipment.

[0091] If the grinding wheel wears too quickly, leading to increased grinding force or unsatisfactory surface roughness, grinding parameters should be adjusted promptly, such as reducing the feed rate, increasing the grinding wheel speed, or replacing the grinding wheel. Simultaneously, the machined non-standard thread milling cutter stock should be inspected regularly using measuring tools such as a projector and calipers to measure parameters like the angle, width, and depth of the thread grooves, ensuring they meet design requirements. If the inspection results deviate from the design requirements, the grinding parameters should be fine-tuned accordingly, and machining should be repeated until the initial shape of the non-standard thread milling cutter meets the requirements.

[0092] S130. The thread grooves are finished by using a second non-standard grinding wheel to form the final shape of the non-standard thread milling cutter.

[0093] In step S130, a second non-standard grinding wheel with a symmetrical structure is used for finishing. During the grinding process, the second non-standard grinding wheel is subjected to uniform force in all directions, effectively reducing vibration and deviation caused by structural asymmetry, thus laying the foundation for accurately shaping the thread groove and improving the machining quality of non-standard thread milling cutters.

[0094] The thread grooves are finished using a second non-standard grinding wheel to form the final shape of the non-standard thread milling cutter, which has the following parameters:

[0095] The tip radius of the second non-standard grinding wheel is r = R2 - 0.1mm. For example, if R2 is 0.4 mm, then the tip radius r of the grinding wheel is 0.3 mm. This parameter setting allows the tip of the second non-standard grinding wheel to precisely fit the bottom of the thread groove for grinding, ensuring that the radius of the bottom fillet meets the design requirements.

[0096] The included angle d at the tip of the second non-standard grinding wheel should be less than (A1+A2) / 2, that is, less than half of the thread profile angle to avoid interference. Assuming A1 is 30° and A2 is 20°, then (A1+A2) / 2 is 25°. In this case, the included angle d at the tip of the second non-standard grinding wheel should be less than 25°, and can be set to 20°. A smaller tip angle allows for more precise angle control when grinding the side of the thread tooth groove, resulting in a thread shape that meets design requirements.

[0097] The five-axis linkage cycloidal grinding process is adopted, and grinding must be carried out from the shank side of the non-standard thread milling cutter to the head side according to the contour to avoid interference and ensure the smooth progress of the grinding process.

[0098] During the specific grinding process, when the second non-standard grinding wheel cuts into the first threaded inclined surface, grinding is performed from the left side of the second non-standard grinding wheel (the position shown in the diagram) near the tip r, without using the tip r itself. This is determined based on the shape characteristics of the first threaded inclined surface and the grinding requirements, which can better shape the first threaded inclined surface and ensure its accuracy.

[0099] When grinding the bottom R2 of the thread, the work is mainly done by the tip r of the second non-standard grinding wheel. Since the radius of the tip r is set to meet the requirements of the valley fillet radius, it can accurately grind the valley fillet that meets the design standard, ensuring that the shape and size of the valley bottom of the thread tooth groove are accurate.

[0100] When the second non-standard grinding wheel cuts into the second threaded inclined surface, grinding is performed from the right side of the second non-standard grinding wheel (the position shown in the diagram) near the tip r. However, it should be noted that because the second angle of the second threaded inclined surface is smaller than the first angle of the first threaded inclined surface, the second non-standard grinding wheel has a smaller inclination angle when cycloidally grinding the second threaded inclined surface. This can lead to insufficient contact area between the second non-standard grinding wheel and the cutting tool, potentially resulting in incomplete grinding and burrs. Therefore, when leaving a margin of 311 on the right side, it is necessary to leave more to ensure sufficient contact between the grinding wheel and the cutting tool during grinding, achieving a good grinding effect.

[0101] During the finishing process, the machining status must be monitored in real time. Data such as grinding wheel speed, feed rate, and grinding force can be obtained through sensors and monitoring systems installed on the grinding equipment. If any abnormalities are detected, such as a sudden increase in grinding force or unstable grinding wheel speed, machining should be stopped immediately. Equipment malfunctions should be checked or machining parameters adjusted to ensure a stable and reliable machining process.

[0102] Regularly inspect the quality of machined non-standard thread milling cutters. Use measuring tools, such as projectors and coordinate measuring machines, to measure various parameters of the thread grooves, such as angles, radii, and widths, to ensure they meet design requirements. If deviations are found in the inspection results, fine-tune the grinding parameters according to the deviations and re-machine until the final shape of the non-standard thread milling cutter that meets the requirements is achieved.

[0103] It should be noted that, in this disclosure, the first non-standard grinding wheel is made of cemented carbide material, or the second non-standard grinding wheel is made of cemented carbide material, giving it properties such as high hardness, high wear resistance, high strength, and good toughness.

[0104] The multi-wheel collaborative grinding process for non-standard thread milling cutters disclosed herein significantly improves grinding efficiency compared to single-wheel grinding methods in related technologies by setting up two different non-standard grinding wheels to work together. Furthermore, with the combination of external cylindrical grinding and roughing wheel plunge grinding, the finishing wheel can complete the entire profile in one pass, further greatly improving grinding efficiency. In the roughing stage, the first non-standard grinding wheel is used to machine the thread groove profile. Its asymmetrical design effectively solves the problem of excessive load and easy damage to the finishing grinding wheel, while avoiding uneven stress and damage to the finishing grinding wheel caused by excessive roughing or insufficient allowance, thus reducing the probability of grinding wheel damage and lowering processing costs. The multi-wheel collaborative process ensures the consistency and stability of the tool profile accuracy. The special grinding wheel design and grinding method eliminate the risk of geometric interference, ensuring the dimensional accuracy, profile consistency, and excellent surface quality of the tool, meeting the high-precision machining requirements of non-standard thread milling cutters.

[0105] This disclosure also provides a multi-wheel collaborative grinding device for non-standard thread milling cutters, including a device body (not shown in the figure), a grinding part (not shown in the figure), a first non-standard grinding wheel 1, and a second non-standard grinding wheel 2.

[0106] The main body of the equipment serves as the supporting frame for the entire equipment and has the function of installing bar stock, grinding parts, the first non-standard grinding wheel 1, and the second non-standard grinding wheel 2.

[0107] The bar stock to be processed is installed on the pre-set installation position on the equipment body, ensuring that the bar stock is firmly fixed and will not shake or shift during processing to guarantee machining accuracy. Next, the grinding part is installed on the corresponding working part on the equipment body. The function of the grinding part is to perform preliminary processing on the bar stock, removing excess material and grooving it to form thread grooves 31. When installing the grinding part, it is important to ensure that its relative position to the bar stock is accurate, and the feed direction and angle of the grinding part are adjusted so that it can process the bar stock according to the predetermined machining path.

[0108] The first non-standard grinding wheel 1 is mounted on the equipment body. This position is designed and adjusted to ensure that the first non-standard grinding wheel 1 can accurately rough-machine the thread grooves 31. The first non-standard grinding wheel 1 has an asymmetrical structure, with a first inclined surface 11 and a second inclined surface 12 along its thickness direction. The first inclined surface 11 has a first preset angle α with the radial direction of the first non-standard grinding wheel 1, and the second inclined surface 12 has a second preset angle b with the radial direction of the first non-standard grinding wheel 1, with the first preset angle α being greater than the second preset angle b. The purpose of this asymmetrical structure design is to allow different parts of the first non-standard grinding wheel 1 to play different roles during rough machining, based on the shape characteristics and machining requirements of the thread grooves 31, thereby improving machining efficiency and quality.

[0109] For example, when machining certain specific shapes of thread grooves 31, a larger first preset included angle a can make the first inclined surface 11 cut into the bar stock more smoothly, quickly remove more material, and form the general outline of the thread groove 31; while a smaller second preset included angle b can make the second inclined surface 12 perform more precise finishing on certain parts of the thread groove 31 during the machining process, preparing for subsequent finishing.

[0110] Start the equipment to make the first non-standard grinding wheel 1 rotate. Simultaneously, control the equipment body to move the bar stock at a predetermined feed speed and direction, allowing the first non-standard grinding wheel 1 to contact the threaded groove 31 on the bar stock for rough machining. During rough machining, the feed rate and depth of cut of the first non-standard grinding wheel 1 must be reasonably controlled according to the design requirements of the threaded groove 31 to ensure the initial shape of the non-standard thread milling cutter 3 is formed. Through multiple adjustments and machining processes, the shape of the threaded groove 31 gradually approaches the design requirements. However, at this point, the surface roughness is relatively high, requiring subsequent finishing to further improve the surface quality.

[0111] The second non-standard grinding wheel 2 is installed on the equipment body and is used to finish the threaded grooves 31 after rough machining. The second non-standard grinding wheel 2 has a symmetrical structure, which ensures that the second non-standard grinding wheel 2 is subjected to uniform force during the finishing process, thus guaranteeing that the machined threaded grooves 31 have high shape accuracy and good surface quality. The symmetrical structure can also reduce the vibration generated by the grinding wheel when rotating at high speed, thereby improving the stability and reliability of the machining process.

[0112] After roughing with the first non-standard grinding wheel 1, the equipment is switched to finish mode, and the second non-standard grinding wheel 2 begins to rotate. The equipment body is controlled to move the bar stock, allowing the second non-standard grinding wheel 2 to contact the thread groove 31 for finish machining. During finish machining, the feed rate and cutting speed of the second non-standard grinding wheel 2 are controlled, using a smaller depth of cut and a higher cutting speed to achieve better surface quality. Through the fine machining with the second non-standard grinding wheel 2, the machining marks left by roughing are gradually removed, ensuring the surface roughness of the thread groove 31 meets the design requirements, ultimately forming the final shape of the non-standard thread milling cutter 3.

[0113] After the above processing, a non-standard thread end mill 3 is finally formed, which includes a shank 32 and a cutting edge 33. The shank 32 and the cutting edge 33 are firmly connected together by welding or other fixed connection methods. Threaded grooves 31 are provided on the cutting edge 33. The shape and size of the cutting edge 33 are machined according to the design requirements of the non-standard thread end mill 3 to ensure that it can perform well during cutting. The shank 32 is used to mount the non-standard thread end mill 3 onto the tool holder of the machining equipment, providing stable support and power transmission for the end mill.

[0114] The multi-wheel collaborative grinding equipment for non-standard thread milling cutters can efficiently and accurately complete the machining of non-standard thread milling cutters 3 by utilizing the synergistic effect of the first non-standard grinding wheel 1 and the second non-standard grinding wheel 2, thus meeting the machining needs of different users.

[0115] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A process method for multi-wheel collaborative grinding of non- standard thread milling cutter, characterized in that, include: Determine the external grinding path of the non-standard thread milling cutter; According to the determined external cylindrical grinding path, the bar stock is processed to remove the excess part of the bar stock and to perform grooving to form thread grooves. The thread grooves are rough-machined using a first non-standard grinding wheel to form the initial shape of the non-standard thread milling cutter; wherein, the first non-standard grinding wheel has an asymmetrical structure, and the first non-standard grinding wheel has a first inclined surface and a second inclined surface along its thickness direction, the first inclined surface has a first preset angle α with the radial direction of the first non-standard grinding wheel, and the second inclined surface has a second preset angle b with the radial direction of the first non-standard grinding wheel, the first preset angle α being greater than the second preset angle b; The thread grooves are finished by using a second non-standard grinding wheel to form the final shape of the non-standard thread milling cutter; wherein the second non-standard grinding wheel has a symmetrical structure.

2. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 1, characterized in that, Rough machining of the thread grooves to form the initial shape of the non-standard thread milling cutter includes: The first non-standard grinding wheel is used to rough machine the thread groove in a manner perpendicular to the thread groove to form the initial shape of the non-standard thread milling cutter.

3. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 1, characterized in that, The threaded groove has a first threaded inclined surface and a second threaded inclined surface that are disposed opposite to each other. Wherein, the first thread inclined surface is inclined at a first angle A1 relative to the groove depth direction of the thread tooth groove, and the second thread inclined surface is inclined at a second angle A2 relative to the groove depth direction of the thread tooth groove, wherein the first angle A1 is greater than the second angle A2.

4. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 3, characterized in that, The process of removing excess material from the bar stock and grooving it to form thread grooves has the following parameters: The groove openings of the thread tooth grooves located on one side of the first thread inclined surface, the groove openings of the thread tooth grooves located on one side of the second thread inclined surface, and the bottom of the thread tooth grooves are all rounded. The groove of the thread tooth located on one side of the first thread inclined surface and the groove of the thread tooth located on one side of the second thread inclined surface both have a first fillet R1, which is 0.3mm-0.5mm. The bottom of the groove of the thread has a second fillet R2, which is 0.2mm-0.3mm. The groove depth H of the thread tooth is 1.3mm-1.8mm; The non-standard thread milling cutter has a peripheral clearance angle, which has a first clearance angle, a second clearance angle and a third clearance angle arranged sequentially along the circumference of the non-standard thread milling cutter. The first clearance angle is 8°-12°, the second clearance angle is 16°-20°, and the third clearance angle is 23°-30°. The first angle is 22°-25°, and the second angle is 15°-18°.

5. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 4, wherein, The thread grooves are rough-machined to form the initial shape of the non-standard thread milling cutter, which has the following parameters: The first angle A1 is equal to the first preset included angle a, the second angle A2-10°=the second preset included angle b, and the tip width c of the non-standard thread milling cutter is less than 2R2.

6. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 4, wherein, The thread tooth groove is finished by the second non-standard grinding wheel to form the final shape of the non-standard thread milling cutter, which has the following parameters: The tip of the second non-standard grinding wheel is r=R2-0.1, and the included angle d at the tip of the second non-standard grinding wheel is less than (A1+A2) / 2.

7. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 1, wherein, The outer circle grinding path line of the non-standard thread milling cutter is determined, comprising: The thread profile line required by the bar material is drawn in the coordinate system by means of computer-aided design software, the height difference of the profile peak is obtained by fitting algorithm, and then the outer circle grinding path line of the non-standard thread milling cutter is determined.

8. The multi-wheel collaborative grinding process method of non- standard thread milling cutter according to any one of claims 1-7, characterized in that, The profile grinding is performed from the shank side of the non-standard thread milling cutter to the head side of the non-standard thread milling cutter.

9. The process method of multi-wheel collaborative grinding of non- standard thread milling cutter according to claim 1, wherein, The first non-standard grinding wheel and / or the second non-standard grinding wheel is made of hard alloy material.

10. A multi-wheel cooperative grinding apparatus for non-standard thread milling cutters, characterized by, Comprising: A device body for mounting a bar material; A grinding piece provided on the device body, which is used for machining the bar material to remove the excess part of the bar material and slot processing to form a thread tooth groove; A first non-standard grinding wheel provided on the device body; the first non-standard grinding wheel has a first inclined surface and a second inclined surface along the thickness direction thereof, the first inclined surface and the radial direction of the first non-standard grinding wheel have a first preset included angle a, and the second inclined surface and the radial direction of the first non-standard grinding wheel have a second preset included angle b, the first preset included angle a is greater than the second preset included angle b; wherein the first non-standard grinding wheel is used for rough machining of the thread tooth groove to form the initial shape of the non-standard thread milling cutter; A second non-standard grinding wheel provided on the device body; wherein the second non-standard grinding wheel is used for finishing the thread tooth groove to form the final shape of the non-standard thread milling cutter; wherein the second non-standard grinding wheel has a symmetrical structure.

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