A system for establishing chip geometry model in gear cutting

Abstract

The present invention discloses a system for establishing a chip geometry model for gear cutting in the field of numerical control machining technology, including an acquisition module, a modeling module, a monitoring module, a verification module and an update module; the acquisition module is used to obtain the cutting parameters of the machining equipment and the workpiece model to be machined; the modeling module is used to construct a three-dimensional cutting geometry model based on the cutting parameters and the workpiece model; the monitoring module is used to obtain the actual characteristics of the chips generated by the workpiece during the machining process in real time; the verification module is used to compare the actual characteristics with the theoretical characteristics predicted in the three-dimensional cutting geometry model, and if the difference between the actual characteristics and the theoretical characteristics exceeds a preset threshold, the cutting parameters of the subsequent work of the machining equipment are adjusted until the actual characteristics match the theoretical characteristics; the update module is used to update the three-dimensional cutting geometry model based on the verification result of the verification module. This solution can monitor the chips in real time and correct the difference between the model prediction result and the actual result in time.

Description

Technical Field

[0001] The invention belongs to the technical field of numerical control machining, and in particular is a system for establishing a chip geometry model for gear cutting machining. Background Art

[0002] In the field of gear processing, with the continuous advancement of industrial technology and the increasing diversification of product requirements, traditional processing methods have gradually revealed their limitations in certain specific application scenarios. In particular, for non-through, non-retracting internal gears, as well as gears with complex tooth shapes and high precision requirements, traditional processing methods are often unable to cope with them.

[0003] Gear skiving technology, also known as power skiving, gear turning, gear rolling, etc., can be traced back to the continuous pursuit of gear processing accuracy and efficiency. In the late 20th century, with the development of CNC machine tools, precision tools and advanced control technology, gear processing technology has made significant progress. However, for some special structure gears, such as spiral internal gears, non-involute gears, etc., traditional processing methods such as gear hobbing and gear shaping are difficult to guarantee processing accuracy and efficiency.

[0004] Gear cutting technology is based on the principle of the generating method (also known as the fan forming method, conjugate method or envelope method), and achieves precise cutting of gear tooth profiles through specially designed tools and precise processing parameters. The cutting process has the dual effects of "cutting" and "cutting", with small and uniform cutting volume, and can gradually remove materials and form high-precision tooth profiles.

[0005] It is proposed in the prior art that by establishing a geometric model, the influence of different process parameters (such as cutting speed, feed rate, cutting depth, etc.) on the characteristic dimensions of chips (such as length, width, degree of distortion, etc.) can be systematically studied. This helps to optimize process parameters in actual processing and improve processing efficiency and processing quality. By establishing a geometric model, solving cutting force and cutting heat, a theoretical basis is provided for the design of gear cutting tools and the optimization of gear cutting process parameters. However, geometric models are often based on a series of idealized assumptions, such as material uniformity and infinite tool rigidity. These assumptions are often difficult to fully meet in actual processing, resulting in a certain deviation between the model prediction results and the actual processing conditions.

[0006] Therefore, there is an urgent need for a model building system that can detect chips in real time during the machining process and promptly correct the difference between the model prediction results and the actual results. Summary of the invention

[0007] In order to solve the above problems, the purpose of the present invention is to provide a system for establishing chip geometry model for gear cutting processing, which can directly perform high-precision and real-time detection and analysis of the chips generated during the processing, and can quickly compare the model prediction results by timely capturing the actual shape and size changes of the chips, automatically identifying and quantifying the differences between the two, and adjusting the model parameters to achieve timely correction of the model prediction accuracy.

[0008] In order to achieve the above object, the technical solution of the present invention is as follows:

[0009] A system for establishing a chip geometry model for gear cutting, comprising a collection module, a modeling module, a monitoring module, a checking module and an updating module;

[0010] The acquisition module is used to obtain the cutting parameters of the processing equipment and the model of the workpiece to be processed;

[0011] The modeling module is used to construct a three-dimensional cutting geometry model based on cutting parameters and workpiece model;

[0012] The monitoring module is used to obtain the actual characteristics of the chips generated by the workpiece during the machining process in real time;

[0013] The verification module is used to compare the actual features with the theoretical features predicted in the three-dimensional cutting geometry model. If the difference between the actual features and the theoretical features exceeds a preset threshold, the cutting parameters of the subsequent work of the processing equipment are adjusted until the actual features match the theoretical features.

[0014] The updating module is used to update the three-dimensional cutting geometry model based on the verification result of the verification module.

[0015] Further, the characteristics include developed chip thickness, developed chip volume and tool-chip contact length.

[0016] Furthermore, the cutting parameters include tool speed, feed rate, cutting depth and workpiece speed.

[0017] Furthermore, the verification module is used to compare the actual chips of the current batch generated under the initial cutting parameters with the theoretical chips predicted in the three-dimensional cutting geometry model; if the expanded chip thickness of the actual chips differs from the expanded chip thickness of the theoretical chips by more than a preset thickness difference, the cutting parameters of the processing equipment are adjusted when performing the next batch of chips; if the expanded chip volume of the actual chips differs from the expanded chip volume of the theoretical chips by more than a preset volume difference, the cutting parameters of the processing equipment are adjusted when performing the next batch of chips; if the tool-chip contact length of the actual chips differs from the tool-chip contact length of the theoretical chips by more than a preset length difference, the cutting parameters of the processing equipment are adjusted when performing the next batch of chips.

[0018] Further, the monitoring module includes a carrier and a length detection unit for detecting the contact length of the cutting chip; a groove is arranged on the top of the carrier; a secondary collecting groove is arranged below the groove, and the secondary collecting groove is connected to the groove; a vibrating disk is placed in the groove, and the vibrating disk slides with the groove; a plurality of first driving members for driving the vibrating disk to generate resonance are arranged below the vibrating disk; a plurality of receiving grooves are arranged in the vibrating disk, and the receiving groove only accommodates a single chip; secondary grooves are arranged on the side walls on opposite sides of the receiving groove, and a plurality of magnetic extrusion plates are arranged in the secondary grooves, and the extrusion plates are arranged side by side in the secondary grooves, and the adjacent extrusion plates slide with each other, and the extrusion plates slide with the secondary grooves; capacitor plates are arranged on the extrusion plates; in the same receiving groove, a magnetic flux sensor is arranged on any extrusion plate, and a magnetic field generator is arranged on the side of the secondary groove away from the magnetic flux sensor; a channel for guiding the chips into the secondary collecting groove is arranged at the bottom of the receiving groove, and a valve is arranged at the connection between the channel and the receiving groove, and the valve is electrically connected to the control unit; the control unit is electrically connected to the first driving member, the magnetic field generator, the magnetic flux sensor and the capacitor plate respectively;

[0019] A main collecting groove is arranged on one side of the groove; a cleaning component is arranged between the groove and the main collecting groove, and the cleaning component is used to clean the remaining chips on the vibration plate into the main collecting groove, and the cleaning component is electrically connected to the control unit.

[0020] Furthermore, the length detection unit includes a pressure sensor; the pressure sensor is used to collect the pressure changes when the tooth-cutting tool of the processing equipment contacts the workpiece; the control unit is also used to calculate the chip contact length based on the duration of the pressure change and the moving speed of the tooth-cutting tool.

[0021] Furthermore, the cleaning assembly includes a crank arm, a disc and a connecting rod; the groove is connected to the main collecting groove; a movable groove is also provided in the carrier; the disc is rotatably connected to the movable groove; the disc is axially connected to a second driving member for rotating the disc, and the second driving member is electrically connected to the control unit; a slider is eccentrically provided on the disc; one end of the crank arm is rotatably connected to the movable groove; a curved groove is provided on the crank arm; the curved groove is slidably engaged with the slider; the other end of the crank arm is rotatably connected to the connecting rod; the connecting rod is rotatably connected to a slide seat; a slide groove is also provided on the side wall of the groove, and the slide seat is slidably engaged with the slide groove; a push rod is provided on one side of the slide seat, and the push rod is slidably engaged with the groove.

[0022] Further, the control unit is used to calculate the thickness of the expanded chips after being extruded by the extrusion plate based on a thickness calculation formula; the thickness calculation formula is as follows:

[0023]

[0024] In the formula, is the capacitor, is the dielectric constant of the medium, is the area of ​​the two capacitor plates facing each other, is the distance between the two capacitor plates; if the thickness of the unfolded chips is uneven, then the distance between the capacitor plates in the same pair of sub-slots in the same receiving slot is obtained. , and divide the chips into paragraph, will Capacitor plates with the same value are classified into the same category, and the proportion of capacitor plates of the same category in each group is calculated.

[0025] Further, the control unit is used to calculate the expansion area of ​​the chips by a magnetic flux formula based on the magnetic field strength generated by the magnetic field generator and the magnetic flux detected by the magnetic flux sensor; the magnetic flux formula is as follows:

[0026]

[0027] In the formula, Ф is the magnetic flux, B is the magnetic field intensity, and S is the expanded chip area;

[0028] The expanded chip volume is calculated based on the calculated expanded chip area. If the expanded chip thickness is uneven, the volume of each part is calculated based on the proportion of each group of the same type of capacitor plates, and then the volume of each part is accumulated to obtain the expanded chip volume.

[0029] Furthermore, the control unit is also used to obtain the effective expanded chip thickness in all the receiving slots on the vibration plate, and take the median of the effective expanded chip thickness as the final expanded chip thickness; obtain the effective expanded chip volume in all the receiving slots on the vibration plate, and take the median of the effective expanded chip volume as the final expanded chip volume.

[0030] The technical principles of the above scheme are as follows:

[0031] During the workpiece processing, the cutting parameters of the processing equipment and the workpiece model to be processed are obtained through the acquisition module, and the three-dimensional cutting geometry model is established through the modeling module; because the workpiece is affected by various factors during the processing, the predicted results of the three-dimensional chip geometry model will deviate from the actual situation; at this time, when the processing equipment cuts off the first batch of chips, the batch of chips falls on the vibration plate, and the chips on the vibration plate are resonated by starting the second drive member and fall into the receiving groove, and then the magnetic field is generated by the magnetic field generator, so that the extrusion plate flattens and expands the chips (no plastic deformation occurs inside the chips), and then the distance between the capacitor plates is used to indirectly judge the thickness of the expanded chips; the expanded chip area is calculated by the magnetic flux formula; and then the expanded chip volume is calculated by the expanded chip thickness and the expanded chip area. The chip contact length is calculated by the duration of the pressure change generated when the tooth cutting tool contacts the workpiece when the processing equipment cuts the first batch of chips, and the moving speed of the tooth cutting tool. The actual developed chip thickness, developed chip volume and tool-chip contact length are compared with the predicted results to determine whether the predicted results are accurate. If not, the cutting parameters of the processing equipment are adjusted during the next chip cutting. The above process is repeated until the predicted results are accurate and the three-dimensional cutting geometry model is updated in real time.

[0032] The above scheme has the following beneficial effects:

[0033] 1. This solution can obtain the actual characteristics of the chips generated by the workpiece during the machining process in real time through the monitoring module, including key parameters such as the expanded chip thickness, expanded chip volume, and tool-chip contact length. The real-time performance ensures that the system can capture the actual shape and size changes of the chips in a timely manner, providing accurate data support for subsequent model correction.

[0034] 2. This solution can timely capture the actual shape and size changes of chips through real-time monitoring and analysis of chips generated during the processing, and realize high-precision and real-time detection of chip characteristics. This helps to find problems in time and make adjustments. The system automatically adjusts cutting parameters such as tool speed, feed rate, cutting depth and workpiece speed according to the actual chip characteristics, thereby ensuring that the processing process is always in the best state and improving processing quality and efficiency.

[0035] 3. In this solution, based on the verification results of the verification module, the system can update the 3D cutting geometry model in real time to reflect the actual processing conditions. This dynamic update mechanism ensures that the model is always consistent with the actual situation, thereby improving the reliability of model prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a system block diagram of an embodiment of a system for establishing a chip geometry model for gear skiving.

[0037] Figure 2 A top view of the monitoring module.

[0038] Figure 3 for Figure 2 Middle AA section view.

[0039] Figure 4 for Figure 2 Middle BB cross-section.

[0040] Figure 5 for Figure 4 A partial enlarged schematic diagram of point C in the middle.

[0041] Figure 6 Schematic diagram of the formation process of tooth cutting chips.

[0042] Figure 7 Schematic diagram of tooth cutting motion.

[0043] The figure marks in the drawings of the specification include: 1. carrier; 2. vibration plate; 3. main collecting groove; 4. auxiliary collecting groove; 5. first driving member; 6. chips; 7. push rod; 101. groove; 102. movable groove; 103. disc; 104. crank arm; 105. curved groove; 106. slider; 107. connecting rod; 108. slide seat; 109. slide groove; 201. receiving groove; 202. valve; 203. channel; 204. auxiliary groove; 205. extrusion plate; 2051. magnetic flux sensor; 206. capacitor plate; 207. magnetic field generator; 301. through groove. DETAILED DESCRIPTION

[0044] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0045] In the description of the present invention, it is to be understood that the terms “longitudinal”, “lateral”, “vertical”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside” and “outside” etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0046] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0047] The following is further described in detail through specific implementation methods:

[0048] The embodiment is basically as shown in the attached Figure 1-Figure 7 As shown: A system for establishing a chip geometry model for gear cutting, mainly including a collection module, a modeling module, a monitoring module, a verification module and an update module.

[0049] The acquisition module is used to obtain the cutting parameters of the processing equipment and the model of the workpiece to be processed;

[0050] Specifically, the acquisition module obtains the cutting parameters of the processing equipment in real time, such as tool speed, feed rate, cutting depth, and workpiece speed, and simultaneously obtains the model of the workpiece to be processed (in this embodiment, the workpiece model is obtained using a 3D scanner), which contains information such as the geometric shape and size of the workpiece.

[0051] The modeling module is used to construct a 3D cutting geometry model based on cutting parameters and workpiece model.

[0052] Specifically, model construction mainly includes the following three steps:

[0053] The first step is to build a blade sweep model:

[0054] In the process of gear skiving, three basic movements are involved: the rotation of the workpiece, the rotation of the tool, and the feed of the tool along the axis of the workpiece. These movements together determine the geometric characteristics of the skiving process. Assume that the workpiece is fixed and the axial distance between the gear skiving tool axis and the workpiece axis is The movement of the cutting edge of a tooth of a tooth-cutting cutter relative to the workpiece forms a swept surface, which is called the edge swept surface. .

[0055] Rotational motion of a workpiece: The workpiece rotates around its axis (i.e., the coordinate system of axis) with angular velocity Rotation. This movement allows the workpiece tooth surface to gradually come into contact with the tool and cut.

[0056] Rotational motion of the tool: The tool moves around its axis (i.e. the coordinate system of axis) with angular velocity Rotation. The rotational motion of the tool is the key to the cutting process, as it determines the relative motion trajectory of the cutting edge and the workpiece tooth surface.

[0057] Feed motion: The tool moves along the workpiece axis (i.e. the coordinate system of Axis or auxiliary coordinate system of The feed motion allows the cutting process to continue until the entire tooth surface is machined.

[0058] Create the following coordinate system:

[0059] Workpiece coordinate system :With the workpiece axis as Axis, establish rectangular coordinate system This coordinate system is used to establish the workpiece tooth surface model and describe the rotational motion of the workpiece during the machining process.

[0060] Tool coordinate system :With tool axis as Axis, establish rectangular coordinate system This coordinate system is used to establish the tool model and describe the rotation and feed motion of the tool during the machining process.

[0061] Auxiliary coordinate system Sp: In order to simplify the description and calculation, the auxiliary coordinate system Sp is introduced to simplify the description and calculation. Parallel auxiliary coordinate system The spatial position of this coordinate system is fixed and does not change with time, but it can be used to describe the movement and rotation of the workpiece coordinate system S1 relative to its initial position.

[0062] Auxiliary coordinate system :Similarly, the tool coordinate system is introduced Parallel auxiliary coordinate system The spatial position of this coordinate system is also fixed and does not change over time. It can be used to describe the tool coordinate system. Translation and rotation relative to its initial position.

[0063] The edge sweep is the cutting edge in the workpiece coordinate system The swept surface is formed in the tool coordinate system, while the cutting edge of the tooth cutting tool is usually in the tool coordinate system In order to express the blade sweep surface, the workpiece coordinate system To establish a chip model in , coordinate system conversion is required. To coordinate system The transformation matrix is:

[0064]

[0065] Each matrix in the formula is a coordinate transformation matrix:

[0066]

[0067]

[0068]

[0069] In the formula, Representing coordinate system To coordinate system The transformation matrix, Representing coordinate system To coordinate system The transformation matrix, Representing coordinate system To coordinate system The transformation matrix of . and Respectively represent the angular velocity of the workpiece and tool during the cutting process, Represents the displacement of the workpiece or tool along the axial direction of the workpiece.

[0070] and Represent the number of teeth of the workpiece and tool respectively, satisfying:

[0071]

[0072]

[0073] In order to obtain the blade scanning model, it is necessary to transform the tool coordinate system into The cutting edge in the workpiece coordinate system is transformed into the workpiece coordinate system middle:

[0074]

[0075] In the formula, express Point on the cutting edge, Indicates the tool coordinate system Middle The distance from a point on the cutting edge of a blade sweep to the tool axis, , , Respectively In the tool coordinate system middle axis, axis, Component in the direction of the axis. Transform the cutting edge into the workpiece coordinate system According to formula (8), the blade sweep surface can be obtained:

[0076]

[0077] In the formula, express The point on the middle blade sweep surface, Indicates the coordinate system from the tool To workpiece coordinate system The transformation matrix of . Equation (8) can be expanded to obtain the parameter equation of the blade scanning surface:

[0078]

[0079] In the formula,

[0080] The second step is to establish the blade sweep family model:

[0081] During the tooth-scratching process, each tooth contacts and scrapes the tooth groove of the workpiece in turn, forming a series of edge sweeps. These edge sweeps change continuously with the relative motion of the workpiece and the tool, forming a complex family of edge sweeps.

[0082] Assume that a certain tooth (such as tooth 1) first contacts and scrapes a tooth groove of the workpiece to perform the first edge sweep process. The time for sweeping the tooth groove is After the workpiece rotates one circle, The blade tooth sweeps the tooth groove again, that is, the second blade sweep process is performed, and the generated blade sweep surface is , the sweep time is , satisfying the following relations:

[0083]

[0084] In the formula, Represents remainder.

[0085] Due to the periodicity of the cutting process, the blade sweeping process of different teeth on the same tooth groove has similar characteristics. Based on this characteristic, we can deduce that when the workpiece rotates Week later, the During the first blade sweeping process, the blade sweeps the surface Contact tooth groove The time is ,satisfy:

[0086]

[0087] According to the above formula, it can be deduced that when the workpiece rotates Week later, first tooth cutting The 1st and 2nd teeth Secondary cutting of tooth groove of The angle between the teeth is:

[0088]

[0089] Combining formulas (7) and (13), we can get the tooth cutter The parameter equation of the cutting edge on the cutter tooth:

[0090]

[0091] Combining formulas (8) and (14), The parameter equation of the blade sweep formed by the secondary cutting tooth groove is as follows:

[0092]

[0093]

[0094] In the formula,

[0095] According to equations (15) and (16), several blade sweeps can be calculated, and their collection constitutes a blade sweep family.

[0096] The third step is to establish a three-dimensional chip geometry model:

[0097] Combined with the chip generation process analysis, the developed chip in the complete cutting state is a spatial geometric body surrounded by three surfaces, namely the tooth surface to be processed (the first in the family of the previous cutting edge) and the The machined tooth surface is composed of 3 blade sweeping surfaces (The first The blade sweeps of this machining process are composed of Blade sweep . Through discrete cutting edges , by combining equations (15) and (17), we can solve the coordinates of the intersection point with the surface during the blade sweep process of any blade point, that is, , , , and then the intersection lines A, B, and C of the three surfaces are obtained by the curve fitting method, that is, the boundary lines of the unfolded geometric chips. Based on this, the boundary positions of the machined tooth surface, the tooth surface to be machined, and the edge sweep surface that constitute the chip contour are determined respectively to establish a three-dimensional chip geometry model, as shown in formula (17).

[0098]

[0099] The monitoring module is used to obtain the actual characteristics of the chips generated by the workpiece during the machining process in real time.

[0100] Specifically, the monitoring module includes a carrier 1 and a length detection unit for detecting the contact length of the cutting tool;

[0101] As attached Figure 2 and attached Figure 4 As shown, a groove 101 is provided on the top of the carrier 1; an auxiliary collecting groove 4 is provided below the groove 101, and the auxiliary collecting groove 4 is connected to the groove 101; a vibration plate 2 is placed in the groove 101, and the vibration plate 2 and the groove 101 are slidably matched; a plurality of first driving members 5 for driving the vibration plate 2 to resonate are provided below the vibration plate 2, and in this embodiment, the first driving member 5 is a voice coil motor; a plurality of accommodating grooves 201 are provided in the vibration plate 2, and the accommodating groove 201 only accommodates a single chip 6; as shown in the attached Figure 5 As shown, the side walls of the receiving groove 201 on both sides are provided with auxiliary grooves 204, and a plurality of magnetic extrusion plates 205 are arranged in the auxiliary grooves 204. The extrusion plates 205 are arranged side by side in the auxiliary grooves 204, and the adjacent extrusion plates 205 are slidably matched, and the extrusion plates 205 and the auxiliary grooves 204 are slidably matched; the extrusion plates 205 are bonded and fixed with capacitor plates 206, and specifically, as shown in the attached Figure 5 As shown, the capacitor plate 206 is located on the opposite side of the extrusion plate 205; in the same receiving groove 201, a magnetic flux sensor 2051 is welded and fixed on any extrusion plate 205, and a magnetic field generator 207 is installed on the side of the auxiliary groove 204 away from the magnetic flux sensor 2051. In this embodiment, the magnetic flux sensor 2051 is located on the extrusion plate 205 on the left, and the magnetic field generator 207 is located on the right. In this embodiment, the magnetic field generator 207 is an electromagnet; a channel 203 for introducing the chips 6 into the auxiliary collecting groove 4 is opened at the bottom of the receiving groove 201, and a valve 202 is welded and fixed at the connection between the channel 203 and the receiving groove 201, and the valve 202 is electrically connected to the control unit; the control unit is electrically connected to the first driving member 5, the magnetic field generator 207, the magnetic flux sensor 2051 and the capacitor plate 206 respectively;

[0102] A main collecting groove 3 is also provided on one side of the groove 101; a cleaning component is provided between the groove 101 and the main collecting groove 3, and the cleaning component is used to clean the remaining chips 6 on the vibration plate 2 into the main collecting groove 3, and the cleaning component is electrically connected to the control unit.

[0103] Specifically, as attached Figure 3As shown, the cleaning assembly includes a crank arm 104, a disc 103 and a connecting rod 107; the groove 101 is connected to the main collecting groove 3, and specifically, a through groove 301 is provided between the groove 101 and the main collecting groove 3 in this embodiment; a movable groove 102 is also provided in the carrier 1; the disc 103 is rotatably connected to the movable groove 102; the disc 103 is axially connected to a second driving member for rotating the disc 103, and the second driving member is electrically connected to the control unit. In this embodiment, the second driving member is a servo motor; a slider 106 is eccentrically provided on the disc 103 The slider 106 is welded and fixed to the disk 103; one end of the crank arm 104 is rotatably connected to the movable groove 102 through a rotating shaft; a curved groove 105 is provided on the crank arm 104; the curved groove 105 is slidably matched with the slider 106; the other end of the crank arm 104 is rotatably connected to the connecting rod 107 through a rotating shaft; the connecting rod 107 is rotatably connected to the slide seat 108; a slide groove 109 is also provided on the side wall of the groove 101, and the slide seat 108 is slidably matched with the slide groove 109; a push rod 7 is welded and fixed to one side of the slide seat 108, and the push rod 7 is slidably matched with the groove 101.

[0104] In this embodiment, the length detection unit includes a pressure sensor; the pressure sensor is used to collect the pressure change when the tooth-cutting tool of the processing equipment contacts the workpiece; the control unit is also used to calculate the chip contact length based on the duration of the pressure change and the moving speed of the tooth-cutting tool. Specifically, the duration of the pressure change is the duration t of the pressure collected by the pressure sensor, and the moving speed of the tooth-cutting tool is v, then the chip contact length L=vt. This embodiment takes the tooth-cutting processing of 45 steel as an example.

[0105] The tool speed of the processing equipment is set to 450r / min, the feed rate is 0.2mm / r, the cutting depth is 0.7mm, and the workpiece speed is 385r / min.

[0106] The structural parameters of the tooth-scraping tool of the processing equipment are shown in Table 1:

[0107] Table 1 Structural parameters of tooth-scraping tool and workpiece

[0108] Parameter name Parameter Value Parameter name Parameter Value Number of cutter teeth 22 Workpiece teeth number 40 Tool helix angle 20° Tool helix angle 0° Tool top rake angle 10° Workpiece arc radius 5.8mm Tool top edge clearance angle 6.3° Workpiece distribution circle diameter 128mm Tool material GU20 Workpiece material QT450-10 Material hardness Higher than HRC65 Material hardness HB170-210

[0109] The carrier 1 is placed below the chip outlet of the processing equipment. When the first batch of chips 6 of the workpiece is generated, the chips 6 fall into the vibration plate 2. The control unit starts the voice coil motor, which drives the chips 6 on the vibration plate 2 to resonate. The interference principle of resonance and coherent waves is used to make the chips 6 move in a certain direction and form an arrangement. After vibrating for a preset time, a part of them falls into the receiving groove 201. At this time, the control unit starts the electromagnet to generate a magnetic field, so that the squeezing plate 205 squeezes and expands the chips 6 that fall into the receiving groove 201; the control unit obtains the capacitance value of the capacitor plate 206, and then calculates the distance between the capacitor plates 206 to obtain the expanded chip thickness, and then obtains the magnetic flux passing through the chips 6 through the magnetic flux sensor 2051, and then uses the magnetic flux formula as follows:

[0110]

[0111] In the formula, Ф is the magnetic flux, B is the magnetic field intensity, and S is the expanded chip area;

[0112] Calculate the developed chip area. Then calculate the developed chip volume by combining the developed chip thickness and the developed chip area.

[0113] After the data of the expanded chip thickness, expanded chip volume and chip contact length are acquired, the control unit controls the valve 202 to open, so that the chips 6 in the receiving groove 201 fall into the auxiliary collecting groove 4 along the channel 203. At the same time, the chips 6 remaining on the vibration plate 2 (the chips 6 falling into the receiving groove 201 during resonance) are cleaned, and the control unit starts the servo motor, and the output shaft of the servo motor drives the disc 103 to rotate, and the rotation of the disc 103 drives the slider 106 to move back and forth in the curved groove 105, thereby driving the crank arm 104 to deflect back and forth, and the crank arm 104 drives the connecting rod 107 to drive the slide 108, and the slide 108 moves back and forth in the slide groove 109, thereby driving the push rod 7 to scrape the chips 6 on the vibration plate 2 into the through groove 301 until they fall into the main collecting groove 3 for temporary storage. At this point, a complete monitoring is completed.

[0114] The verification module is used to compare the actual features with the theoretical features predicted in the three-dimensional cutting geometry model. If the difference between the actual features and the theoretical features exceeds a preset threshold, the cutting parameters of the subsequent work of the processing equipment are adjusted until the actual features match the theoretical features.

[0115] Specifically, according to the processing requirements and precision standards, the preset differences of the expanded chip thickness, expanded chip volume and tool-chip contact length are set. The verification module is used to compare the actual chips of the current batch generated under the initial cutting parameters with the theoretical chips predicted in the three-dimensional cutting geometry model; if the expanded chip thickness of the actual chips differs from the expanded chip thickness of the theoretical chips by more than the preset thickness difference, the cutting parameters of the processing equipment are adjusted when the next batch of chips is processed; if the expanded chip volume of the actual chips differs from the expanded chip volume of the theoretical chips by more than the preset volume difference, the cutting parameters of the processing equipment are adjusted when the next batch of chips is processed; if the tool-chip contact length of the actual chips differs from the tool-chip contact length of the theoretical chips by more than the preset length difference, the cutting parameters of the processing equipment are adjusted when the next batch of chips is processed.

[0116] According to the adjusted cutting parameters, the cutting process is re-performed and new actual chip data is collected.

[0117] Repeat the process of comparison, judgment and adjustment until the difference between the actual chips and the theoretical chips is within the preset range, thus achieving the optimization of the cutting process.

[0118] The updating module is used to update the 3D cutting geometry model based on the verification result of the verification module. Specifically, the cutting parameters and the 3D cutting geometry model are continuously optimized according to the feedback in the actual cutting process.

[0119] The only difference between the second embodiment and the first embodiment is that, if the thickness of the expanded chips is uneven, the volume of each part is calculated based on the proportion of each group of capacitor plates 206 of the same type, and then the volume of each part is accumulated to obtain the expanded chip volume.

[0120] Specifically, if the thickness of the chips 6 is uneven, the control unit will obtain multiple sets of different values ​​from the capacitor plates 206 on each set of extrusion plates 205 in the same receiving slot 201. For example, five sets of extrusion plates 205 (such as the attached one) are provided in one receiving slot 201. Figure 5 As shown, the extrusion plates 205 arranged opposite to each other are a group), after the chips 6 are extruded and expanded, the middle section of the chips 6 has three layers (represented here as ), there is only one layer at both ends of the chip (represented here as , that is, thick in the middle and thin at both ends), at this time, there are 3 groups of capacitor plates 206 on the extrusion plate 205, and the distance between them is , the distance between the capacitor plates 206 on the two sets of extrusion plates 205 is , that is, the chips are divided into two areas, namely and , each accounting for and , the control unit first calculates when calculating the expanded chip volume Multiply by the developed chip area S and then by , and then calculate Multiply by the developed chip area S and then by , and then add the two results to get the developed chip volume.

[0121] The only difference between Example 3 and the above-mentioned Example 2 is that the control unit is also used to obtain the effective expanded chip thickness in all the receiving slots 201 on the vibration plate 2, and take the median of the effective expanded chip thickness as the final expanded chip thickness; obtain the effective expanded chip volume in all the receiving slots 201 on the vibration plate 2, and take the median of the effective expanded chip volume as the final expanded chip volume.

[0122] Specifically, when there is no chip 6 in the receiving slot 201, the extrusion plates 205 will fit together, and the capacitance of the capacitor plate 206 will increase significantly. The control unit determines that there is no chip 6 in the receiving slot 201 here, and records it as invalid. The expanded chip thickness and expanded chip volume calculated by the capacitor plates 206 containing chips 6 in the remaining receiving slots 201 are recorded as valid. Then, the median of these valid expanded chip thicknesses and expanded chip volumes is taken as the final actual monitoring result.

[0123] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and / or characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A system for establishing a chip geometry model for gear cutting, comprising an acquisition module and a modeling module, wherein the acquisition module is used to obtain cutting parameters of a processing device and a workpiece model to be processed; and the modeling module is used to construct a three-dimensional cutting geometry model based on the cutting parameters and the workpiece model; the system is characterized in that: It also includes a monitoring module, a checking module and an updating module; The monitoring module is used to obtain in real time the actual characteristics of the chips (6) generated during the machining process of the workpiece; The verification module is used to compare the actual features with the theoretical features predicted in the three-dimensional cutting geometry model. If the difference between the actual features and the theoretical features exceeds a preset threshold, the cutting parameters of the subsequent work of the processing equipment are adjusted until the actual features match the theoretical features. The updating module is used to update the three-dimensional cutting geometry model based on the checking result of the checking module; The monitoring module comprises a carrier (1) and a length detection unit for detecting the contact length of a cutting chip; a groove (101) is arranged on the top of the carrier (1); a secondary collecting groove (4) is arranged below the groove (101), and the secondary collecting groove (4) is connected to the groove (101); a vibration plate (2) is placed in the groove (101), and the vibration plate (2) and the groove (101) are slidably matched; a plurality of first driving members (5) for driving the vibration plate (2) to generate resonance are arranged below the vibration plate (2); a plurality of accommodating grooves (201) are arranged in the vibration plate (2), and the accommodating groove (201) only accommodates a single cutting chip (6); secondary grooves (204) are arranged on the side walls of opposite sides of the accommodating groove (201), and a plurality of magnetic extrusion plates (205) are arranged in the secondary grooves (204), and the extrusion plates (205) are arranged side by side in the secondary grooves (204). Adjacent extrusion plates (205) are slidably matched with each other, and the extrusion plates (205) and the auxiliary grooves (204) are slidably matched with each other; capacitor plates (206) are provided on the extrusion plates (205); a magnetic flux sensor (2051) is provided on any extrusion plate (205) in the same receiving groove (201), and a magnetic field generator (207) is provided on the side of the auxiliary groove (204) away from the magnetic flux sensor (2051); a channel (203) for guiding the chips (6) into the auxiliary collecting groove (4) is provided at the bottom of the receiving groove (201), a valve (202) is provided at the connection point between the channel (203) and the receiving groove (201), and the valve (202) is electrically connected to a control unit; the control unit is electrically connected to the first driving member (5), the magnetic field generator (207), the magnetic flux sensor (2051) and the capacitor plate (206) respectively; A main collecting groove (3) is provided on one side of the groove (101); a cleaning component is provided between the groove (101) and the main collecting groove (3); the cleaning component is used to clean the remaining chips (6) on the vibration plate (2) into the main collecting groove (3); the cleaning component is electrically connected to the control unit.

2. The system for establishing a chip geometry model for gear cutting according to claim 1, characterized in that: The characteristics include developed chip thickness, developed chip volume, and tool-chip contact length.

3. The system for establishing a chip geometry model for gear cutting according to claim 2, characterized in that: The cutting parameters include tool speed, feed rate, cutting depth and workpiece speed.

4. The system for establishing a chip geometry model for gear cutting according to claim 3, characterized in that: The verification module is used to compare the actual chips (6) of the current batch generated under the initial cutting parameters with the theoretical chips (6) predicted in the three-dimensional cutting geometry model; if the difference between the expanded chip thickness of the actual chips (6) and the expanded chip thickness of the theoretical chips (6) exceeds a preset thickness difference, the cutting parameters of the processing equipment are adjusted when the next batch of chips (6) is processed; if the difference between the expanded chip volume of the actual chips (6) and the expanded chip volume of the theoretical chips (6) exceeds a preset volume difference, the cutting parameters of the processing equipment are adjusted when the next batch of chips (6) is processed; if the difference between the tool-chip contact length of the actual chips (6) and the tool-chip contact length of the theoretical chips (6) exceeds a preset length difference, the cutting parameters of the processing equipment are adjusted when the next batch of chips (6) is processed.

5. The system for establishing a chip geometry model for gear cutting according to claim 4, characterized in that: The length detection unit includes a pressure sensor; the pressure sensor is used to collect the pressure changes when the tooth-cutting tool of the processing equipment contacts the workpiece; the control unit is also used to calculate the chip contact length based on the duration of the pressure change and the moving speed of the tooth-cutting tool.

6. The system for establishing a chip geometry model for gear cutting according to claim 5, characterized in that: The cleaning assembly comprises a crank arm (104), a disc (103) and a connecting rod (107); the groove (101) is connected to the main collecting groove (3); a movable groove (102) is also provided in the carrier (1); the disc (103) is rotatably connected to the movable groove (102); the disc (103) is axially connected to a second driving member for rotating the disc (103), and the second driving member is electrically connected to the control unit; a slider (106) is eccentrically provided on the disc (103); one end of the crank arm (104) is connected to the movable groove (1 02) is rotatably connected; a curved groove (105) is provided on the crank arm (104); the curved groove (105) and the slider (106) are slidably matched; the other end of the crank arm (104) is rotatably connected to the connecting rod (107); the connecting rod (107) is rotatably connected to the slide seat (108); a slide groove (109) is also provided on the side wall of the groove (101), and the slide seat (108) and the slide groove (109) are slidably matched; a push rod (7) is provided on one side of the slide seat (108), and the push rod (7) and the groove (101) are slidably matched.

7. The system for establishing a chip geometry model for gear cutting according to claim 6, characterized in that: The control unit is used to calculate the thickness of the expanded chips after being extruded by the extrusion plate (205) based on a thickness calculation formula; the thickness calculation formula is as follows: ; In the formula, is the capacitor, is the dielectric constant of the medium, is the area facing each other of the two capacitor plates (206), is the distance between the two capacitor plates (206); if the thickness of the unfolded chips is uneven, the distance between the capacitor plates (206) in the same pair of auxiliary grooves (204) in the same receiving groove (206) is obtained. , and divide the chips into paragraph, will Capacitor plates (206) with the same value are classified into the same category, and the proportion of capacitor plates of the same category in each group is calculated.

8. The system for establishing a chip geometry model for gear cutting according to claim 7, characterized in that: The control unit is used to calculate the expansion area of ​​the chips (6) by a magnetic flux formula based on the magnetic field strength generated by the magnetic field generator (207) and the magnetic flux detected by the magnetic flux sensor (2051); the magnetic flux formula is as follows: ； In the formula, is the magnetic flux, is the magnetic field strength, To expand the chip area; The expanded chip volume is calculated based on the calculated expanded chip area. If the expanded chip thickness is uneven, the volume of each part is calculated based on the proportion of each group of the same type of capacitor plates (206), and then the volume of each part is accumulated to obtain the expanded chip volume.

9. The system for establishing a chip geometry model for gear cutting according to claim 8, characterized in that: The control unit is further used to obtain the effective expanded chip thickness in all the receiving slots (201) on the vibration plate (2), and take the median of the effective expanded chip thickness as the final expanded chip thickness; and to obtain the effective expanded chip volume in all the receiving slots (201) on the vibration plate (2), and take the median of the effective expanded chip volume as the final expanded chip volume.

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