Variable-geometry parameter design method and configuration of a wear-reducing turning tool

Abstract

The present application belongs to the technical field of turning tool wear reduction, and discloses a variable-geometric-parameter wear-reducing turning tool design method and configuration. Firstly, the wear form and causes of the turning tool trailing face are analyzed in the turning process of difficult-to-machine materials. Secondly, the turning tool rake angle, relief angle and blunt circle radius are selected as the design parameters among the adjustable tool geometric parameters. Then, the influence law of the design parameters on the turning tool trailing face wear width is obtained based on software simulation. Finally, the tool rake angle, relief angle and blunt circle radius are adjusted to make the above parameters change uniformly along the tool circular edge and remain constant at the tool straight edge, thereby completing the variable-geometric-parameter turning tool design. The present application evaluates the wear reduction performance of different configurations of tools by software simulation, saving time and cost. Meanwhile, the designed variable-geometric-parameter turning tool can effectively reduce the trailing face wear at the turning tool tip and curb the further deterioration of the tool groove wear, meeting the differentiated wear reduction requirements of the turning tool at different cutting positions.

Description

Technical Field

[0001] This invention belongs to the field of cutting tool grinding reduction technology, specifically relating to a design method and configuration for a grinding reduction cutting tool with variable geometry parameters. Background Technology

[0002] With the increasing demands for equipment performance in aerospace, defense, and other fields, lightweight, thin-walled, and integrated components are widely used, such as aerospace structural parts, engine casings, and integral bladed disks. These high-performance components have thin walls but large overall dimensions, resulting in extremely high material removal rates during machining and significant tool wear issues. Furthermore, these components are often made of difficult-to-machine materials such as high-temperature alloys, high-strength steel, and titanium alloys. During cutting, intense friction occurs between the tool and chip, and between the tool and workpiece, further shortening the lifespan of the cutting tools and significantly limiting the forming accuracy, surface quality, and machining efficiency of high-performance components.

[0003] A well-designed tool profile helps to reduce the force and heat response of the tool, decrease friction in the cutting contact area, and thus improve tool life. Invention patent CN105631072A discloses a design method for a flat-end mill for rough machining of aluminum alloys, which reduces cutting force, cutting heat, and elastic strain during the cutting process by optimizing the rake angle, clearance angle, helix angle, and blunt radius of the milling cutter. Invention patent CN103862073A discloses a turning method and turning tool, which increases the sharpness of the turning tool by optimizing its rake angle, clearance angle, principal cutting edge angle, secondary cutting edge angle, and inclination angle, thus avoiding chip sticking during target material cutting. The literature “Patel K, Liu G, Shah SR, et al. Effect of Micro-Textured Tool Parameters on Forces, Stresses, Wear Rate and Variable Friction in Titanium Alloy Machining[J]. Journal of Manufacturing Science and Engineering, 2019, 142(2):1-31” designed a micro-textured turning tool for titanium alloy machining. By optimizing the geometry of the microtexture, the cutting performance of the tool is improved, thereby reducing the wear rate of the turning tool. Invention patent CN101596607A discloses a TiZrN coated tool and its preparation method, wherein the tool surface is a TiZrN layer, and there is a Ti and Zr / Ti transition layer between the TiZrN layer and the tool substrate. This multi-coating structure helps to reduce friction and suppress tool wear.

[0004] Existing technologies treat the entire cutting edge of a lathe tool as a single design entity, uniformly improving wear resistance at each point on the cutting edge through methods such as tool angle optimization, microtexture customization, and tool coating preparation. However, the cutting edge of a lathe tool typically consists of two parts: a circular arc edge and a straight edge, with significant differences in cutting thickness at different points on the circular arc edge. This means that the force and thermal loads experienced at each point are different, resulting in a typical non-uniform distribution of wear on the flank face of the lathe tool. Current constant-parameter tool design methods and tool configurations cannot meet the differentiated wear reduction requirements at different points on the cutting edge of a lathe tool. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a design method and configuration for a variable geometry parameter wear-reducing turning tool, in order to solve the problem of differential wear of existing turning tools at different cutting positions.

[0006] The technical solution of the present invention: A tool design method for reducing cutting tool wear, comprising the following steps: Step 1: Wear morphology analysis of the cutting face of the lathe tool; First, the cutting edge of the lathe tool is divided into two parts: the circular arc edge and the straight edge. The cutting edges are then discretized, and an orthogonal plane is introduced at each discretization point to describe the tool geometry and cutting state information. The analysis shows that the cutting thickness gradually increases from the tool apex along the circular arc edge and remains constant at the straight edge. This inconsistent cutting contact state induces a differentially distributed force and heat load along the cutting edge, which in turn leads to a non-uniform wear band on the flank face of the cutting tool. In the tip wear zone, the insufficient cutting thickness prevents the material to be removed from forming chips upwards along the tool separation point. Instead, it moves downwards under the action of plowing and is eventually squeezed onto the workpiece surface, which intensifies the friction between the tool and the workpiece. The poor heat dissipation conditions at the tool tip further aggravate the wear problem here. In the groove wear zone, due to the surface hardening layer, stress gradient, and chip scratching, a narrow V-shaped groove tends to appear near the contact point between the cutting edge and the workpiece surface, and gradually widens and deepens. It can be seen that increasing the tool sharpness helps to reduce tip wear, while reducing the tool sharpness helps to suppress the occurrence of groove wear. The wear bands in the above two regions jointly limit the service life of turning tools for difficult-to-machine materials, but their requirements for the configuration of anti-grinding tools are contradictory. Step 2: Selection of geometric parameters for the cutting tool to be designed; Based on finite element analysis software, a cutting simulation model is established to describe the turning state. The tool arc radius, cutting edge width, blunt circle radius, rake angle, clearance angle, groove shape, and groove depth are selected as the parameter set. The maximum bandwidth of the back face wear is used as the main evaluation index. At the same time, the manufacturing difficulty and cost of the tool are also taken into account. Finally, the tool rake angle, tool clearance angle, and tool blunt circle radius are selected from the above parameter set as the three geometric parameters to be designed for the anti-grinding tool. Step 3: Wear resistance simulation of turning tools with different configurations; Based on the established turning simulation model, investigate the law of wear bandwidth of the tool flank face changing with the geometric parameters to be designed; Simulation results show that as the tool rake angle increases, the force and heat response value of the cutting contact area decreases, and the wear bandwidth of the flank face also decreases accordingly; As the tool clearance angle increases, the contact length between the tool flank face and the workpiece decreases, and the wear bandwidth of the flank face also decreases accordingly; As the tool blunt radius increases, the thickness of the material to be removed that moves downward due to the plowing action also gradually increases, which intensifies the friction between the tool and the workpiece, and the wear bandwidth of the flank face also increases accordingly. Step 4: Configuration design of variable geometry cutting tool; In response to the non-uniformly distributed wear band on the tool's flank face, the wear simulation results of cutting tools with different configurations are combined to adjust the design geometry parameters of the tool so that they change continuously along the cutting edge of the cutting tool, which increases both the tool sharpness at the tool tip arc and the tool strength in the groove wear zone.

[0007] Specifically, a grinding reduction tool for turning difficult-to-machine materials has a rhomboid insert structure, comprising a main cutting edge, a secondary cutting edge, and a circular arc cutting edge connecting the two cutting edges. The axis of symmetry of the main and secondary cutting edges divides the circular arc cutting edge into two symmetrical parts. The intersection of the axis of symmetry and the circular arc cutting edge is defined as the tool vertex, where the blunt radius of the designed grinding reduction tool is the smallest, and the rake angle and clearance angle are the largest. Subsequently, the designed geometric parameters of the tool vary uniformly along the circular arc cutting edges on both sides, with the blunt radius gradually increasing and the rake angle and clearance angle gradually decreasing. At the main and secondary straight cutting edges, the blunt radius, rake angle, and clearance angle of the designed tool remain unchanged. Furthermore, the tool geometric parameters of the main and secondary cutting edges are symmetrical, and the tool vertex divides the circular arc cutting edge into two segments, with the tool geometric parameters of the two segments also being symmetrical.

[0008] Furthermore, the range of the rake angle of the tool to be designed is 3°. 15°.

[0009] Furthermore, the range of variation for the clearance angle of the tool to be designed is 3°. 15°.

[0010] Furthermore, the range of variation of the blunt radius of the tool to be designed is as follows: .

[0011] Furthermore, the angle between the primary and secondary cutting edges of the variable geometry grinding tool insert is 55°.

[0012] Furthermore, the radius of the arc of the blade tip is within the range of 0.1 mm. 0.4 mm.

[0013] The beneficial effects of this invention are as follows: This invention addresses the turning process of difficult-to-machine materials, proposing a tool design method to reduce tool wear, and based on this, designing a wear-reducing turning tool configuration with variable geometry parameters. This invention uses software simulation to understand the variation of the flank wear bandwidth with tool geometry parameters, obtaining the wear-reducing performance of different tool configurations without the need for extensive trial cutting experiments, saving time and costs. Simultaneously, the designed variable geometry turning tool can effectively reduce tool tip wear and curb further deterioration of groove wear, meeting the differentiated wear reduction requirements at different cutting positions of the turning tool. Attached Figure Description

[0014] Figure 1 Includes (a) to (e), where (a) is a partial schematic diagram of the tool tip structure during the turning process; (b) is a schematic diagram of the cutting layer parameters of the rake face of the turning tool during the turning process; (c) is a schematic diagram of the wear area on the flank face of the cutting tool during the turning process; (d) is a schematic diagram of the discrete positions of the cutting edge of the lathe tool; (e) is a schematic diagram of two-dimensional tool cutting at different discrete positions.

[0015] Figure 2 It is a line graph showing the change in the wear width of the cutting tool's flank face as a function of the tool's rake angle.

[0016] Figure 3 It is a line graph showing the change in the wear width of the cutting tool's flank face as a function of the tool's clearance angle.

[0017] Figure 4 It is a line graph showing the variation of the wear width on the flank face of a lathe tool with the radius of the tool's blunt circle.

[0018] Figure 5 Includes (a) to (e), where (a) is a partial enlarged view of the cutting edge structure of the designed tool; (b) is the designed cutting tool Schematic diagram of tool geometry parameters at the cross-section; (c) is the designed cutting tool and Schematic diagram of tool geometry parameters; (d) is the designed cutting tool and Schematic diagram of tool geometry parameters; (e) is the designed cutting tool and Schematic diagram of tool geometry parameters at the cross-section.

[0019] Figure 6 Includes (a) to (c), where (a) is a line graph showing the change of the rake angle of the designed tool with respect to the actual principal cutting edge angle; (b) is a line graph showing the variation of the clearance angle of the designed tool with the actual principal cutting edge angle; (c) is a line graph showing the variation of the blunt radius of the designed tool with the actual principal cutting edge angle. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: A tool design method for reducing cutting tool wear, comprising the following steps: Step 1: Analysis of the wear morphology of the cutting tool's flank; such as... Figure 1 As shown, in the turning of a rotating part, the feed direction of the tool is parallel to the rotation axis of the part. The cutting edge of the turning tool is divided into a circular arc edge and a straight edge, and these cutting edges are discretized. An orthogonal plane Si (i=1,2,3…,9) is introduced at each discrete point to describe the tool's geometric parameters and cutting state information at the discrete position. The angle between the contour tangent of the cutting edge of the turning tool and the tool feed direction is defined as the actual principal cutting edge angle, which is used to locate the orthogonal plane Si. In this example, the actual principal cutting edge angles corresponding to planes S1, S3, and S8 are 0°, 40°, and 62.5°, respectively. When the tool feed rate is f=0.1 mm / r, the cutting thicknesses corresponding to the above discrete positions are T1=0.027 mm, T3=0.08 mm, and T8=0.089 mm, respectively. The cutting thickness gradually increases from the tool apex along the circular arc edge and remains constant at the straight edge. This non-uniform cutting contact state induces differentially distributed force and heat loads along the cutting edge, resulting in a non-uniform wear band on the tool's flank face. Therefore, the tool's flank face wear zone is divided into a tip wear zone (RC), a uniform wear zone (RB), and a groove wear zone (RN), with the wear bands of these three zones represented by VC, VB, and VN, respectively. In the tip wear zone (RC), the insufficient cutting thickness prevents the material to be removed from forming chips upwards along the tool separation point. Instead, it moves downwards under the plowing action and is eventually pressed onto the workpiece surface, exacerbating the tool-workpiece inter-feedback. Friction, and the poor heat dissipation at the tool tip further exacerbates the tool wear problem at this point; in the groove wear zone RN, due to the hardened layer of the machined surface, stress gradient, and chip abrasion, a narrow V-shaped groove tends to appear near the contact point between the cutting edge and the workpiece surface, and gradually widens and deepens; it can be seen that increasing the tool sharpness helps to reduce wear at the tool tip, while reducing the tool sharpness helps to suppress groove wear. The above two wear zones together restrict the service life of turning tools for difficult-to-machine materials, but the requirements for the configuration of anti-grind tools are contradictory; Step 2: Selection of geometric parameters for the cutting tool to be designed; Based on the finite element analysis software AdvantEdge, a cutting simulation model is established to describe the turning state. The tool arc radius, cutting edge width, blunt circle radius, rake angle, clearance angle, groove shape, and groove depth are selected as the parameter set. The maximum bandwidth of the back face wear is used as the main evaluation index. At the same time, the manufacturing difficulty and cost of the tool are also taken into account. Finally, the tool rake angle, tool clearance angle, and tool blunt circle radius are selected from the above parameter set as the three geometric parameters to be designed for the anti-grinding tool. Step 3: Wear resistance simulation of turning tools with different configurations; using the established turning simulation model, investigate the law of tool flank wear variation with the geometric parameters to be designed; as shown in 2, the range of tool rake angle variation is selected as [3°, 15°], and the simulation results show that as the tool rake angle increases, the force and heat response value of the cutting contact area decreases, and the wear bandwidth of the flank also decreases accordingly; as shown in 3, the range of tool clearance angle variation is selected as [3°, 15°], and the simulation results show that as the tool clearance angle increases, the contact length between the tool flank and the workpiece decreases, and therefore the wear bandwidth of the flank also decreases accordingly; as shown in 4, the range of tool blunt radius variation is selected as [10 μm, 30 μm], and the simulation results show that as the tool blunt radius increases, the thickness of the material to be removed moving downward due to the plowing action also gradually increases, which intensifies the friction between the tool and the workpiece, and therefore the wear bandwidth of the flank will also increase accordingly; Step 4: Configuration design of variable geometry cutting tool; In response to the non-uniformly distributed wear band on the tool's flank face, the wear simulation results of cutting tools with different configurations are combined to adjust the design geometry parameters of the tool so that they change continuously along the cutting edge of the cutting tool, which increases both the tool sharpness at the tool tip arc and the tool strength in the groove wear zone.

[0021] The aforementioned anti-grinding tool for turning difficult-to-machine materials, Figure 5 The geometric parameters of the tool with this configuration at different discrete positions are given. The cutting tool insert has a rhomboid structure, comprising a main cutting edge, a secondary cutting edge, and a circular arc cutting edge connecting the two cutting edges. The included angle between the main and secondary cutting edges is preferably 55°, and the radius of the circular arc cutting edge is preferably 0.2 mm. The axis of symmetry between the main and secondary cutting edges divides the circular arc cutting edge into two symmetrical parts. The intersection of the axis of symmetry and the circular arc cutting edge is defined as the tool vertex. At this point, the blunt radius of the designed anti-grinding tool is the smallest, at 10 μm, while the rake angle and clearance angle are the largest, both at 15°. Subsequently, the tool's geometric parameters are adjusted to vary uniformly along the circular arc cutting edge, with the blunt radius gradually increasing and the rake angle and clearance angle gradually decreasing. At the intersection of the main and secondary cutting edges of the circular arc cutting edge, the blunt radius is 20 μm, and the rake angle and clearance angle are both 9°. Figure 6This is a schematic diagram showing the continuous variation of the rake angle, clearance angle, and blunt radius of the cutting tool with the actual principal cutting edge angle. In addition, the tool geometry parameters of the main cutting edge and the secondary cutting edge are symmetrical, and the tool vertex divides the tool tip arc into two segments, and the tool geometry parameters of the two arc segments are also symmetrical.

[0022] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing a variable geometry grinding reduction cutting tool, characterized in that, The steps are as follows: Step 1: Wear morphology analysis of the cutting tool's flank face; The straight cutting edge and the circular cutting edge of the lathe tool are discretized separately. The tool geometry parameters corresponding to each discrete point are described by an orthogonal plane. Under the given cutting parameters, the cutting state of the tool at each discrete point is understood. Then, the wear causes are analyzed in combination with the actual wear pattern of the lathe tool's flank face. The main wear areas affecting the tool's service life are determined, and the preliminary requirements for the anti-grind lathe tool configuration are proposed accordingly. Step 2: Selection of geometric parameters for the cutting tool to be designed; A cutting simulation model describing the turning state was established based on finite element analysis software. The tool arc radius, cutting width, blunt circle radius, rake angle, clearance angle, groove shape, and groove depth were selected as the parameter set. The maximum bandwidth of the back face wear was used as the main evaluation index. At the same time, the manufacturing difficulty and cost of the tool were also taken into account. Finally, the tool rake angle, tool clearance angle, and tool blunt circle radius were selected from the above parameter set as the three geometric parameters to be designed for the anti-grinding tool. Step 3: Simulation of wear resistance of cutting tools with different configurations; Based on the established turning simulation model, the influence of the tool rake angle, tool clearance angle and tool blunt circle radius on the wear bandwidth of the flank face were determined. The range of the rake angle of the tool to be designed is 3°. 15°; The range of variation for the clearance angle of the tool to be designed is 3°. 15°; The range of variation of the blunt radius of the tool to be designed is: ; The included angle between the primary and secondary cutting edges of the variable geometry grinding tool insert is 55°. The radius of the arc of the blade tip is 0.1 mm. 0.4 mm; Step 4: Configuration design of the variable geometry cutting tool; To address the non-uniformly distributed wear band on the tool's flank face, and based on the wear simulation results of different tool configurations, the tool's design geometry parameters were adjusted to continuously vary along the cutting edge. This increased both the tool sharpness at the tool tip arc and the tool strength in the groove wear zone. The design geometry parameters of the anti-grinding tool varied uniformly along both sides of the tool tip arc, with the blunt radius gradually increasing and the rake angle and clearance angle gradually decreasing.

2. A variable geometry parameter grinding reduction turning tool for turning difficult-to-machine materials, characterized in that, The variable geometry regrinding cutting tool insert has a rhomboid structure, comprising a main cutting edge, a secondary cutting edge, and a circular arc cutting edge connecting the two cutting edges. The axis of symmetry of the main and secondary cutting edges divides the circular arc cutting edge into two symmetrical parts, and the intersection of the axis of symmetry and the circular arc cutting edge is defined as the tool vertex. The designed regrinding cutting tool has the smallest blunt radius and the largest rake angle and clearance angle at this point. At the main and secondary cutting edges, the blunt radius, rake angle, and clearance angle of the designed tool remain unchanged. In addition, the tool geometry parameters of the main and secondary cutting edges are symmetrical, and the tool vertex divides the circular arc cutting edge into two segments, with the tool geometry parameters of the two segments also being symmetrical.

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