An apparatus and method for grinding and polishing camshafts.

Abstract

This invention provides an apparatus and method for camshaft grinding and polishing, belonging to the field of precision machining technology. The apparatus integrates grinding wheel grinding and abrasive waterjet polishing processes. Through a control module using the NSGA-II multi-objective optimization algorithm, the polishing process is optimized to achieve high polishing efficiency and low surface roughness. The main structure of the apparatus includes a bed module, a spindle drive module, a moving grinding wheel module, a moving center module, a lifting and moving nozzle module, and a polishing fluid circulation system. The spindle drive module and the moving center module are located at opposite ends of the bed module, working together to clamp and rotate the camshaft. The moving grinding wheel module features a transverse and longitudinal slide rail design for continuous machining. The lifting and moving nozzle module and valve module work together to control polishing process parameters. The bed module incorporates a three-stage filtration system for polishing fluid recycling. This invention, through process integration and algorithm optimization, solves the technical problems of low efficiency and difficult quality control in traditional step-by-step machining.

Description

Technical Field

[0001] This invention relates to the field of camshaft precision machining technology, specifically to an apparatus and method for camshaft grinding and polishing. Background Technology

[0002] The camshaft is a crucial transmission control component in an engine, its primary function being to control the opening and closing of the engine valves. Specifically, as the camshaft rotates around its own axis, the cam section, with its convex curved surface, opens the valve, allowing gas to enter the combustion chamber. Through combustion with fuel, gas generates energy and performs work; furthermore, the opening of the valve also expels the exhausted exhaust gases. Therefore, the curvature accuracy of the cam section directly affects the valve opening timing and height, thus indirectly influencing the gas inflow and exhaust gas outflow each time the valve opens.

[0003] Currently, the machining of the camshaft cam section mainly consists of two processes: grinding and polishing. First, a grinding wheel rotates and moves radially along the camshaft to adapt to its curved surface shape, performing rough and fine grinding on the cam surface. After grinding, specialized polishing equipment is used for finishing. However, this step-by-step machining method has some problems: 1. Long idle travel waiting time: The polishing process can only be carried out after the grinding process of all cam parts is completed.

[0004] 2. Difficulty in guaranteeing machining quality: The camshaft needs to be clamped a second time on the polishing equipment, which may lead to new positioning errors.

[0005] 3. High cost of multiple processing equipment: Currently, there is very little processing equipment that can perform grinding and polishing of camshafts in one go. This means that two separate processing equipment are needed to meet the processing requirements, which increases the cost of purchasing and maintaining the equipment.

[0006] 4. Difficulty in achieving both efficiency and quality goals: The polishing process of the cam part relies on the processing experience of traditional operators, making it difficult to optimize the operation using automated equipment and the best combination of process parameters.

[0007] In summary, existing technologies for camshaft machining still suffer from low efficiency, difficulty in quality control, and high costs. This invention aims to provide a new technical solution to overcome these shortcomings of the prior art. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides an apparatus and method for grinding and polishing camshafts. The invention aims to enable abrasive waterjet polishing during the idle stroke time after grinding in a single setup, thereby improving processing efficiency and product quality while reducing production costs.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This application provides an apparatus for grinding and polishing camshafts, the apparatus comprising: A clamping module for clamping a camshaft and driving the camshaft to be processed to rotate about its own axis; A movable grinding wheel module, which is used for grinding the camshaft; A lifting and moving nozzle module is used to perform abrasive waterjet polishing on a camshaft. The lifting and moving nozzle module is configured to be displaced relative to the camshaft in three orthogonal directions to adjust the spatial position of the nozzle relative to the cam surface of the camshaft. A polishing fluid circulation system is provided to supply polishing fluid to the lifting and moving nozzle module. The control module is electrically connected to the clamp module, the moving grinding wheel module, the lifting moving nozzle module, and the polishing fluid circulation system to control the movement and operating parameters of each module.

[0010] Preferably, the device further includes: a bed module for supporting other modules in the device, the bed module including a bed, the inner wall of the rear end of the bed being provided with a multi-stage filtration structure for separating and filtering abrasive particles and grinding chips of various sizes, the multi-stage filtration structure being hourglass-shaped with the upper end open and connected to the table surface of the bed, the middle part of the multi-stage filtration structure being provided with several layers of herringbone-shaped stacked filter screens of different mesh sizes, the filter end of each layer of filter screen being connected to an abrasive tube, and the lower end of the bed being provided with several layers of square-shaped concentrated grooves that surround the multi-stage filtration structure from the outside in.

[0011] Preferably, the clamping module includes a spindle drive module, which includes a base plate, a bearing housing, a deep groove ball bearing (No. 1), a chuck body, jaws, a large pulley, a small pulley, a motor, and a motor pad. The motor pad and the bearing housing are fixedly connected to the base plate. The motor is fixedly mounted on the motor pad, and the mounting height of the motor is the same as the center height of the chuck body. The chuck body is mounted on the bearing housing by the support of the two deep groove ball bearings (No. 1). The chuck body has several grooves evenly distributed around its circumference, and each of the grooves contains one jaw. The large pulley is mounted on the chuck body by a key connection, and the small pulley is mounted on the motor by a key connection. The mounting positions of the motor and the bearing housing ensure that the large pulley and the small pulley are in the same plane of motion.

[0012] Preferably, the movable grinding wheel module includes a grinding wheel support plate, a grinding wheel transverse slide, a grinding wheel guide rail, a grinding wheel slider, a grinding wheel slider connecting block, a deep groove ball bearing No. 2, a deep groove ball bearing No. 3, a grinding wheel shaft, a grinding wheel, and a servo electric cylinder No. 1; the grinding wheel support plate has a "T" shaped cross-section, and the middle of the grinding wheel support plate is provided with several cylindrical slide rails; the grinding wheel transverse slide is inverted "L" shaped, and the lower end of the grinding wheel transverse slide is provided with several cylindrical holes, each cylindrical hole slidingly engaging with each cylindrical slide rail of the grinding wheel support plate, the grinding wheel transverse slide... Several grinding wheel guide rails are installed on the upper end of the slide, and the grinding wheel slider is slidably connected to the grinding wheel guide rails; the grinding wheel slider is connected to the servo electric cylinder No. 1 through the grinding wheel slider connecting block; the upper part of the grinding wheel slider is semi-circular, and the center of the semi-circle has two stepped holes of different sizes, which are used to install the deep groove ball bearing No. 2 and the deep groove ball bearing No. 3, respectively; the grinding wheel shaft is installed at the center of the deep groove ball bearing No. 2 and the deep groove ball bearing No. 3; the grinding wheel is installed on the grinding wheel shaft.

[0013] Preferably, the clamping module includes a movable center module, which includes a center guide rail, a center slider, a center base plate, a center support seat, a deep groove ball bearing No. 4, a center, a cylinder connecting block, a cylinder, and a locking nut. A plurality of center sliders arranged at fixed intervals are slidably mounted on the center guide rail. The center base plate is mounted on the center slider. The center support seat is mounted in the middle of the center base plate. The center support seat is connected to the cylinder via the cylinder connecting block and the locking nut, and the upper part of the center support seat has a stepped through hole symmetrical in the axial section. Two deep groove ball bearings No. 4 are mounted at both ends of the stepped through hole. The center is mounted at the center of the deep groove ball bearing No. 4.

[0014] Preferably, the lifting moving nozzle module comprises a fixed frame, nozzle transverse moving guide rails, a nozzle transverse moving slider, a No. 3 servo electric cylinder, a lock nut, a lifting fixing plate, a No. 4 servo electric cylinder, a lifting plate, lifting guide posts, nozzle longitudinal moving guide rails, a nozzle longitudinal moving slider, a No. 5 servo electric cylinder, a No. 1 connecting pipeline, a nozzle, a water pump moving slider, a No. 1 water pump and a No. 2 connecting pipeline; a plurality of said nozzle transverse moving guide rails are mounted on said fixed frame; said nozzle transverse moving slider is slidably mounted on said nozzle transverse moving guide rails; said lifting fixing plate and a plurality of said lifting guide posts are fixedly mounted on said nozzle transverse moving slider, a protruding end is provided at the right side of said nozzle transverse moving slider, and said protruding end is connected and fixed with said No. 3 servo electric cylinder through said lock nut; a stepped circle for lifting limiting is provided above said lifting guide post; said No. 4 servo electric cylinder is fixedly mounted on said lifting fixing plate; the movable end of said No. 4 servo electric cylinder is connected with said lifting plate; a plurality of said nozzle longitudinal moving guide rails are respectively mounted at the front and rear ends of said lifting plate; said nozzle longitudinal moving slider is mounted on said nozzle longitudinal moving guide rail at the front end; the top view of said nozzle longitudinal moving slider is in a "convex" shape, the protruding end is provided with a support round hole with a certain height for supporting said No. 1 connecting pipeline, the non-protruding part at the other end of said nozzle longitudinal moving slider is provided with a connecting hole with a certain height for connecting with said No. 5 servo electric cylinder; said water pump moving slider is mounted on said nozzle longitudinal moving guide rail at the rear end; the top view of said water pump moving slider is in a "convex" shape, the protruding end of said water pump moving slider is provided with a semicircular hole with a certain height for supporting said No. 1 connecting pipeline, and a through hole for mounting said No. 1 water pump is provided in the middle of said water pump moving slider; the side through hole of said No. 1 water pump is connected with said No. 1 connecting pipeline, and the bottom through hole of said No. 1 water pump is connected with said No. 2 connecting pipeline; said No. 1 connecting pipeline is provided with two openings, one opening is connected with said No. 1 water pump, and the other opening is connected with said nozzle.

[0015] Preferably, the polishing liquid circulation system comprises a valve module, and said valve module comprises: a valve body, a gate plate, a No. 2 servo electric cylinder and a lock nut; a cylindrical through hole is provided at the front end of said valve body, and a U-shaped groove is formed on the inner wall of the front end of said valve body; three cylindrical through holes with equal inner and outer diameters are provided at the rear end of said valve body, and the middle part of said valve body is hollowed out; two small U-shaped grooves for cooperating and limiting with said gate plate are respectively formed at two ends of said U-shaped groove; a through hole is provided in the middle of said gate plate, two symmetrically arranged boss cylinders are provided at the front end of said gate plate and at a position tangent to said through hole, and a protruding cylindrical threaded hole is provided at the right end of said gate plate; said gate plate is connected with said No. 2 servo electric cylinder through said threaded hole and said lock nut.

[0016] Preferably, the polishing fluid circulation system includes a water tank module, which includes: a water tank base, a water tank, a water pump 2, and a connecting pipe 3; the water tank base has a "T" shaped cross-section and a rectangular opening in the middle; the water tank is a cuboid without a top cover, and a platform is provided in the middle of the outer front side of the water tank, with a cylindrical through hole for installing the water pump 2 directly above the platform; the water pump 2 is connected to the cylindrical through hole through the connecting pipe 3.

[0017] Preferably, the multi-stage filtration structure includes a coarse abrasive tube, a medium abrasive tube, and a fine abrasive tube, all of which are connected to the valve module. After separation and filtration, the abrasive particles are driven by the flow of polishing fluid through the coarse, medium, and fine abrasive tubes connected to the valve module. Finally, under the action of the gate and servo cylinder 2, the three different coarse abrasive particles are sequentially transported to the polishing fluid circulation system, thereby achieving the effect of polishing fluid recycling.

[0018] This application also provides a method for grinding and polishing a camshaft, characterized in that it utilizes the aforementioned camshaft grinding and polishing apparatus, and the method includes the following steps: S1, The camshaft is clamped on the camshaft grinding and polishing device and driven to rotate; S2, using a moving grinding wheel module to grind each cam part of the camshaft; S3, Abrasive waterjet polishing is performed on the camshaft. The control module optimizes and controls the process parameters of the abrasive waterjet polishing process according to the NSGA-II multi-objective optimization algorithm, and selects the optimal process parameters as the control parameters of the abrasive waterjet polishing process. Process parameters include, but are not limited to: the distance between the nozzle and the camshaft of the lifting and moving nozzle module, the flatness of the nozzle opening, the spray angle, the spray pressure, and the polishing time of each abrasive grain; With the abrasive grains of fixed size, the optimization objective of the NSGA-II multi-objective optimization algorithm is to achieve the best balance between minimizing the surface roughness of the camshaft and minimizing the machining time of the camshaft. The NSGA-II multi-objective optimization algorithm execution steps include: S31, initialize an initial population containing several sets of existing process parameter combinations for abrasive waterjet polishing processes, ensuring that the parameter values ​​are within feasible ranges; S32, evaluate each individual in the population and calculate its corresponding optimization objective value; S33, perform non-dominated ranking of the population, divide individuals into different Pareto front levels, and calculate the crowding distance of each individual in its respective front; S34, based on the non-inferiority level and crowding distance of individuals, selects the best individuals to enter the next generation; S35, apply genetic operations of crossover and mutation to generate new individuals in order to explore the parameter space; S36: Merge the parent and offspring populations, and repeat steps such as non-dominated sorting, crowding distance calculation and selection until the set maximum number of iterations is reached and the termination condition is met. S37 outputs a solution set containing a set of Pareto optimal process parameters; wherein, each cam part of the camshaft is sequentially subjected to grinding and abrasive waterjet polishing; during the idle stroke or waiting time after the grinding of each cam surface of the camshaft is completed by the moving grinding wheel module, the lifting moving nozzle module and the polishing fluid circulation system perform abrasive waterjet polishing on the cam parts that have been ground, thereby improving production efficiency.

[0019] The beneficial effects of this invention are as follows: 1. Improved processing efficiency: The grinding and polishing processes of each cam part of the camshaft can be completed sequentially in one clamping, without the positioning error of secondary clamping, thus shortening the processing time.

[0020] 2. Achieving dual goals of efficiency and quality: Integrated processing reduces the changeover time between different processes, and combined with the NSGA-II algorithm to optimize the polishing process, it can stably obtain higher surface precision and lower surface roughness, thereby improving the product qualification rate.

[0021] 3. Optimize processing performance: By utilizing the global optimization capability of the NSGA-II algorithm, the optimal combination of process parameters can be found among multiple conflicting objectives (such as efficiency and quality), achieving the best processing results that are difficult to achieve with traditional methods.

[0022] 4. Cost and space savings: Integrated devices reduce the number of devices and economic costs. Attached Figure Description

[0023] Figure 1 This is an overall schematic diagram of the apparatus and method for grinding and polishing camshafts according to the present invention.

[0024] Figure 2 This is an overall top view of the bed module of the present invention.

[0025] Figure 3 This is the present invention. Figure 2 A cross-sectional schematic diagram of the fan blades in the closed state at point AA.

[0026] Figure 4 This is the present invention. Figure 3 Enlarged view of the fan blades at point A in the open state.

[0027] Figure 5 This is an exploded view of the spindle drive module of the present invention.

[0028] Figure 6 This is an exploded view of the mobile grinding wheel module of the present invention.

[0029] Figure 7 This is an overall schematic diagram of the mobile tip module of the present invention.

[0030] Figure 8 This is the present invention. Figure 7 A cross-sectional diagram of the top-mounted installation method.

[0031] Figure 9 This is an overall schematic diagram of the lifting and moving nozzle module of the present invention.

[0032] Figure 10 This is the present invention. Figure 9 Exploded view of the lifting and moving nozzle module.

[0033] Figure 11 This is an overall schematic diagram of the valve module of the present invention.

[0034] Figure 12 This is a cross-sectional view of the valve module of the present invention. Figure 1 .

[0035] Figure 13 This is a cross-sectional view of the valve module of the present invention. Figure 2 .

[0036] Figure 14 This is a cross-sectional view of the valve module of the present invention. Figure 3 .

[0037] Figure 15 This is a cross-sectional view of the valve module of the present invention. Figure 4 .

[0038] Figure 16 This is an exploded view of the water tank module of the present invention.

[0039] Figure 17 This is a schematic diagram of the control module of the present invention.

[0040] Figure 18 This is a schematic diagram of the workflow of the present invention.

[0041] Figure 19 This is a partially enlarged view of the invention in its actual working state.

[0042] Figure 20 This is a flowchart of the NSGA-II multi-objective optimization algorithm used in this invention.

[0043] Figure 21This is a diagram showing the Pareto optimal solution set results of the NSGA-II multi-objective optimization algorithm applied in this invention.

[0044] In the diagram: 01-Bed module, 02-Spindle drive module, 03-Moving grinding wheel module, 04-Moving center module, 05-Lifting and moving nozzle module, 06-Valve module, 07-Water tank module, 08-Connecting pipe No. 4, 09-Camshaft, 10-Control module, 0101-Bed, 0102-Fine abrasive tube, 0103-Medium abrasive tube, 0104-Coarse abrasive tube, 0105-Chip removal tube, 0106-Fan blade, 0201-Base plate, 0202-Bearing housing, 0203-Deep groove ball bearing. Bearing No. 1, 0204-Chuck Body, 0205-Chuck Jaw, 0206-Large Pulley, 0207-Small Pulley, 0208-Motor, 0209-Motor Pad, 0301-Grinding Wheel Support Plate, 0302-Grinding Wheel Transverse Slide, 0303-Grinding Wheel Guide Rail, 0304-Grinding Wheel Slider, 0305-Grinding Wheel Slider Connecting Block, 0306-Deep Groove Ball Bearing No. 2, 0307-Deep Groove Ball Bearing No. 3, 0308-Grinding Wheel Shaft, 0309-Grinding Wheel, 0310-Servo Electric Cylinder No. 1, 0401-Top 0402-Point guide rail, 0403-Point base plate, 0404-Point support seat, 0405-Deep groove ball bearing No. 4, 0406-Point limit cover, 0407-Point, 0408-Cylinder connecting block, 0409-Cylinder, 0410-Locking nut, 0501-Fixed frame, 0502-Nozzle lateral movement guide rail, 0503-Nozzle lateral movement slider, 0504-Servo electric cylinder No. 3, 0505-Lifting fixed plate, 0506-Servo electric cylinder No. 4, 0507-Lifting... Lowering plate, 0508-Lifting guide column, 0509-Nozzle longitudinal moving guide rail, 0510-Nozzle longitudinal moving slider, 0511-Servo electric cylinder No. 5, 0512-Connecting pipe No. 1, 0513-Nozzle, 0514-Water pump moving slider, 0515-Water pump No. 1, 0516-Connecting pipe No. 2, 0601-Valve body, 0602-Gate, 0603-Servo electric cylinder No. 2, 0701-Water tank seat, 0702-Water tank, 0703-Water pump No. 2, 0704-Connecting pipe No. 3. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, specific examples and references to the appendix are described below. Figure 1 To be continued Figure 21 The present invention will be described in further detail below. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0046] like Figure 1 and Figure 17 As shown, the present invention provides an apparatus for grinding and polishing a camshaft, the apparatus comprising: a bed module 01, configured to carry other modules of the apparatus.

[0047] a fixture module, wherein the fixture module is configured to clamp the camshaft 09 and drive the to-be-processed camshaft 09 to rotate around its own axis; the fixture module comprises a spindle driving module 02 and a movable tailstock center module 04, the spindle driving module 02 and the movable tailstock center module 04 are respectively installed on two sides of the bed module 01, and cooperate to clamp and drive the to-be-processed camshaft 09 to rotate around its axis.

[0048] a movable grinding wheel module 03, wherein the movable grinding wheel module 03 is configured to perform grinding processing on the camshaft 09.

[0049] a lifting movable nozzle module 05, installed on the bed module 01, configured to perform abrasive water jet polishing on a cam surface of the camshaft.

[0050] a polishing liquid circulation system, which comprises a valve module 06, a water tank module 07, a No. 4 connecting pipe 08 and a multi-stage filtering structure arranged inside the bed module 01, configured to provide controlled polishing liquid for the lifting movable nozzle module, and is controlled by a control module 10; in the present application, the multi-stage filtering structure is a three-stage filtering system.

[0051] a control module 10, wherein the control module 10 is electrically connected to the spindle driving module 02, the movable tailstock center module 04, the movable grinding wheel module 03, the lifting movable nozzle module and the polishing liquid circulation system respectively, so as to control the movement and working parameters of each module.

[0052] As Figure 2 , Figure 3 and Figure 4 shown, the bed module 01 comprises a bed body 0101, a fine abrasive particle pipe 0102, a medium abrasive particle pipe 0103, a coarse abrasive particle pipe 0104, a chip discharge pipe 0105 and fan blades 0106.

[0053] an "hourglass-shaped" three-stage filtering system is arranged in the bed body 0101.

[0054] the upper part of the three-stage filtering system is in an inverted conical funnel shape, six fan blades 0106 in a合闸 state and a three-layer filtering inclined net structure stacked in a "herringbone" shape are installed in the middle part of the three-stage filtering system, the lower part of the three-stage filtering system is conical, and is connected with a "square"-shaped concentration槽 which is sequentially surrounded from outside to inside by four layers and arranged at the bottom end of the bed body.

[0055] The central tank is divided into four volumetric tanks. The innermost volumetric tank has a hole in the middle wall for installing the fine abrasive tube 0102. The second volumetric tank from the inside out has two holes, one for the fine abrasive tube 0102 and the other for the medium abrasive tube 0103. The third volumetric tank from the inside out has three holes, two for the fine abrasive tube 0102 and the medium abrasive tube 0103 and the third for the coarse abrasive tube 0104. The outermost volumetric tank has four holes, three for the fine abrasive tube 0102, the medium abrasive tube 0103 and the coarse abrasive tube 0104. The side wall has a fourth hole for installing the chip removal tube 0105.

[0056] like Figure 5 As shown, the spindle drive module 02 includes a base plate 0201, a bearing seat 0202, a deep groove ball bearing No. 1 0203, a chuck body 0204, chuck jaws 0205, a large pulley 0206, a small pulley 0207, a motor 0208, and a motor pad 0209.

[0057] Three circumferentially distributed jaws 0205 are mounted on the chuck body 0204, used to clamp the camshaft 09. Supported by two identical deep groove ball bearings (No. 1, 0203), the camshaft is mounted in the center hole of the bearing housing 0202. The height of the center hole of the bearing housing 0202 is the same as the rotation center height of the motor 0208 mounted on the pad 0209, ensuring that the large pulley 0206 and the small pulley 0207 are at the same height and in the same plane, thus guaranteeing transmission stability.

[0058] like Figure 6 As shown, the movable grinding wheel module 03 includes a grinding wheel support plate 0301, a grinding wheel transverse slide 0302, a grinding wheel guide rail 0303, a grinding wheel slider 0304, a grinding wheel slider connecting block 0305, a deep groove ball bearing No. 2 0306, a deep groove ball bearing No. 3 0307, ​​a grinding wheel shaft 0308, a grinding wheel 0309, and a servo electric cylinder No. 1 0310.

[0059] The grinding wheel support plate 0301 has a "T"-shaped cross-section and four symmetrically arranged cylindrical guide rail structures of equal diameter in the middle. The grinding wheel transverse slide 0302 is installed on the grinding wheel support plate 0301 through four equal-diameter holes at the bottom and can move laterally along the guide rail structures.

[0060] Two grinding wheel guide rails 0303 are installed at one end of the grinding wheel transverse slide 0302. Servo electric cylinder 1 0310 is installed at the other end of the grinding wheel transverse slide 0302. The grinding wheel slider 0304 is installed on the grinding wheel guide rail 0303, and is connected to servo electric cylinder 1 0310 through the grinding wheel slider connecting block 0305. The longitudinal displacement is achieved by the extension and retraction of servo electric cylinder 1 0310.

[0061] Both deep groove ball bearings 2 (0306) and 3 (0307) are embedded in the center hole of the grinding wheel slider 0304 via stepped holes. The grinding wheel shaft 0308 is mounted on the deep groove ball bearings 2 (0306) and 3 (0307). The grinding wheel 0309 is mounted in the middle of the grinding wheel shaft 0308, and its thickness covers the width of the cam portion of the camshaft 09.

[0062] The grinding wheel 0309 can sequentially grind the cam surface of the camshaft 09 through the lateral displacement of the grinding wheel transverse slide 0302 and the longitudinal displacement of the grinding wheel slider 0304.

[0063] like Figure 7 and Figure 8 As shown, the movable center module 04 includes a center guide rail 0401, a center slider 0402, a center base plate 0403, a center support seat 0404, a deep groove ball bearing No. 4 0405, a center limit cover 0406, a center 0407, a cylinder connecting block 0408, a cylinder 0409, and a locking nut 0410.

[0064] Each of the center guide rails 0401 has two center sliders 0402 mounted on it. The center base plate 0403 is mounted on the four center sliders 0402, enabling lateral displacement.

[0065] The center support 0404 is mounted above the center base plate 0403 in the middle and is connected to the cylinder 0409 via the preload action of the cylinder connecting block 0408 and the locking nut 0410. The cylinder 0409 is mounted on the bed 0101. The deep groove ball bearing No. 4 0405 is embedded in the hole through a symmetrical stepped hole structure provided above the center support 0404. The center 0407 is installed in the hole of the deep groove ball bearing No. 4 0405.

[0066] The center limit cover 0406 is installed at one end of the center support seat 0404. The convex structure on one side of the cover serves to limit the longitudinal installation of both the center 0407 and the deep groove ball bearing No. 4 0405.

[0067] like Figure 9 and Figure 10 As shown, the lifting and moving nozzle module 05 includes a fixed frame 0501, a nozzle lateral moving guide rail 0502, a nozzle lateral moving slider 0503, a servo electric cylinder 3 0504, a lifting fixed plate 0505, a servo electric cylinder 4 0506, a lifting plate 0507, a lifting guide column 0508, a nozzle longitudinal moving guide rail 0509, a nozzle longitudinal moving slider 0510, a servo electric cylinder 5 0511, a connecting pipe 1 0512, a nozzle 0513, a water pump moving slider 0514, a water pump 1 0515, and a connecting pipe 2 0516.

[0068] The fixed frame 0501 has a stepped design at both ends, which allows it to be directly installed on the bed 0101.

[0069] The nozzle transverse movement guide rail 0502 is mounted on the fixed frame 0501. The nozzle transverse movement slider 0503 is mounted on the nozzle transverse movement guide rail 0502, with a protruding connecting hole structure at one end and a concave hole structure at each of its four corners. The servo electric cylinder No. 3 0504 is mounted on the bed 0101 and is connected to the nozzle transverse movement slider 0503 through the connecting hole structure to realize transverse displacement control.

[0070] One end of the lifting guide column 0508 is inserted into the nozzle lateral movement slider 0503 through a concave hole structure and is limited by four triangular reinforcing ribs. The other end is equipped with a collar structure. The lifting plate 0507 is connected to the lifting guide column 0508 through holes at its four corners. One end of the plate is equipped with a rectangular opening, and the other end is equipped with a convex hole structure. Its lower surface is equipped with three long strip reinforcing ribs.

[0071] The lifting fixing plate 0505 is vertically mounted on the nozzle horizontal movement slider 0503. Servo electric cylinder 4 (0506) is vertically mounted on the lifting fixing plate 0505 and connected to the lifting plate 0507 via a convex hole structure for lifting control. The nozzle longitudinal movement guide rails 0509 are installed at both ends of the lifting plate 0507, with the nozzle longitudinal movement slider 0510 mounted on one end and the water pump movement slider 0514 mounted on the other. The nozzle longitudinal movement slider 0510 has a through hole structure at one end and a blind connection hole structure at the other. The water pump movement slider 0514 has a semi-circular through hole structure at one end and an open hole structure at the other. Servo electric cylinder 5 (0511) is connected to the nozzle longitudinal movement slider 0510 via a blind connection hole structure and is mounted on the lifting plate 0507.

[0072] The two ends of connecting pipe 1 (0512) are respectively installed on the through-hole structure at one end of the nozzle longitudinal moving slider 0510 and the semi-circular through-hole structure at one end of the water pump moving slider 0514. Nozzle 0513 is connected and fixed to one end of connecting pipe 1 (0512). The side through-hole of water pump 1 (0515) is connected to the other end of connecting pipe 1 (0512) and fixedly installed on the opening structure of water pump moving slider 0514. Connecting pipe 2 (0516) is fixed inside the bottom through-hole of water pump 1 (0515).

[0073] like Figures 11 to 15 As shown, valve module 06 includes valve body 0601, gate 0602, and servo electric cylinder 2 0603.

[0074] Valve body 0601 is roughly rectangular, with one cylindrical through-hole on one side and three cylindrical through-holes on the other. A through square hole in the center of valve body 0601 connects to all the cylindrical holes. The inner surface of valve body 0601 connecting to one of the cylindrical through-holes features a U-shaped groove. A smaller U-shaped groove is formed at each end of the U-shaped groove. Gate 0602 is a rectangular prism with a circular through-hole in its center. Two convex cylinders with the same center height as the cylindrical through-hole are located on one side of the outer end of the circular through-hole. Gate 0602 has a connection hole at one end, which connects to servo electric cylinder 2 0603.

[0075] like Figure 16 As shown, the water tank module 07 includes a water tank base 0701, a water tank 0702, a water pump 2 0703, and a connecting pipe 3 0704.

[0076] The water tank base 0701 and the grinding wheel support plate 0301 have roughly the same structure, the difference being that the middle part has a rectangular opening, and each end has two connection holes. The water tank 0702 is positioned and installed on the water tank base 0701 through the connection holes, and one side of it has a stepped structure. Water pump 2 0703 is installed on the stepped structure of the water tank 0702. One end of the connecting pipe 3 0704 is connected to water pump 2 0703, and the other end is connected to the water tank 0702.

[0077] like Figure 17 and 18 As shown, the control module 10 is electrically connected to the spindle drive module 02, the moving grinding wheel module 03, the moving center module 04, the lifting moving nozzle module 05, and the polishing fluid circulation system, and is used to control the movement and working parameters of each module of the device.

[0078] like Figure 20 As shown, the control module 10 is configured to optimize and control the key experimental process parameters of the abrasive waterjet polishing process according to the NSGA-II multi-objective optimization algorithm, and select the optimal parameter combination as each control parameter.

[0079] The optimization variables of the algorithm include, but are not limited to: the distance D between the nozzle 0513 of the lifting and moving nozzle module 05 and the camshaft 09, the flatness d of the nozzle opening, and the injection angle. The parameters are: jet pressure P (adjusted by controlling water pump 1 0515), and polishing time for each abrasive grain (t_c, t_m, t_f). The coarseness s of the abrasive grains is fixed, and the algorithm's optimization objective is to achieve the best balance between minimizing surface roughness Ra and minimizing processing time T.

[0080] In this invention, the NSGA-II algorithm is executed as follows: First, initialize an initial population containing 20 existing combinations of polishing process parameters (i.e., individuals) to ensure that the parameter values ​​are within feasible ranges.

[0081] Next, each individual in the population is evaluated, and its corresponding optimization objective value is calculated.

[0082] Then, the population is non-dominated, individuals are assigned to different Pareto front levels, and the crowding distance of each individual in its respective front is calculated.

[0083] Subsequently, a selection process is performed based on the individual's non-inferiority level and crowding distance to select the best individuals for the next generation.

[0084] Next, genetic operations such as crossover and mutation are applied to generate new individuals to explore the parameter space. The parent and offspring populations are merged, and steps such as non-dominated sorting, crowding distance calculation, and selection are repeated until the termination condition is met (the maximum number of iterations is reached).

[0085] The algorithm outputs a solution set containing a set of Pareto optimal parameter combinations.

[0086] In this invention, the control module 10 determines an optimal set of polishing process parameters based on the Pareto optimal solution set output by the NSGA-II algorithm, through a preset strategy (selecting a set of parameters that achieve a specific balance between efficiency and quality), and uses it as the control target value for the actual polishing process.

[0087] For example, control module 10 outputs control signals to the servo cylinders (such as servo cylinder 3, 0504, etc.) in the lifting and moving nozzle module 05 according to the selected optimal speed parameters, controlling the nozzle to move precisely. Based on the selected optimal pressure and flow parameters, control signals are also output to the pumps in the polishing fluid circulation system (such as...). Figure 17 The water pump 1 (0515) regulates the supply of polishing slurry. This intelligent optimization control based on the NSGA-II algorithm ensures that the polishing process always operates near-optimal, thus consistently achieving efficient and high-quality polishing results. The parameters and results of the polishing experiment are shown in Table 1. The optimal combination of Pareto parameters and the empirical parameter combination are shown in Table 2.

[0088] Table 1. Experimental parameters and results Table 2. Optimal Combinations of Pareto Parameters and Empirical Parameter Combinations In this invention, the size of the filter screen holes in the three-stage filtration system of bed 0101 is only to indicate that the hole size of each stage gradually decreases downwards, and is not the actual size. It needs to be determined according to the specific coarse, medium and fine abrasive grains.

[0089] In this invention, the lower end of the grinding wheel transverse slide 0302 is designed with an electromagnet, which can be directly adsorbed and fixed on the grinding wheel support plate 0301 after being energized.

[0090] In this invention, the nozzle 0513 is mainly displaced in three orthogonal directions by servo electric cylinders 3 (0504), 4 (0506), and 5 (0511) to control its spatial distance relative to the cam surface of the camshaft 09.

[0091] In this invention, the gate 0602 connects different holes in the valve body 0601 via the servo electric cylinder 2 0602.

[0092] In this invention, the length, width, and height dimensions of the water tank 0702 include, but are not limited to, the displacement stroke of the nozzle 0513 in three orthogonal directions, so as to ensure that the water pump 1 can continuously draw polishing liquid for polishing.

[0093] When production begins, the appropriate abrasive particles and polishing liquid are first pre-filled into the volumetric tanks of the three-stage filtration system in the bed 0101. The camshaft 09 is then fixed to the device via the spindle drive module 02 and the moving center module 04. Next, the moving grinding wheel module 03 is activated to perform a grinding process on the cam surface of the camshaft 09. While the grinding wheel 0309 is grinding the next cam surface, the lifting moving nozzle module 05 and the polishing liquid circulation system are activated to perform a polishing process on the cam surface of the camshaft 09 (e.g., polishing). Figure 19 (As shown). In the default state, gate 0602 is first connected to coarse abrasive tube 0104. The polishing fluid is pumped by water pump 2 through connecting pipes 4 and 3 to water tank 0702. Then, pumped by water pump 1 (0515), it flows through connecting pipe 1 (0512) and is sprayed onto the cam surface of camshaft 09 through nozzle 0513. After use, the polishing fluid flows back and passes through a three-stage filtration system. The uppermost filter screen first filters out the coarsest chips, which are discharged through chip discharge pipe 0105. The system then filters out coarse, medium, and fine abrasive particles, which enter the corresponding volume tanks and are then transported to valve module 06 through the three abrasive tubes, thus repeating the cycle. When different degrees of polishing are required, servo cylinder 2 (0603) connects the central through hole of gate 0602 to different abrasive tubes to deliver polishing fluid with different abrasive particles.

[0094] like Figure 21 As shown, in this invention, the distance D between nozzle 0513 and camshaft 09 is selected as 3.66 mm, the nozzle opening flatness d is 0.7 mm, and the spray angle is... The final parameter combination was 14.81°, jet pressure P was 56.4MPa, coarse polishing time t_c was 20.8s, medium polishing time t_m was 14.4s, fine polishing time t_f was 27.2s, coarse abrasive grain s_c was 100µm, medium abrasive grain s_m was 50µm, and fine abrasive grain s_f was 10µm. This combination achieved the optimal effect of a total polishing time T of 68.5s and a surface roughness Ra of 0.22µm.

[0095] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the technical solutions of the present invention. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of the patent of the present invention.

Claims

1. An apparatus for grinding and polishing camshafts, characterized in that, Said apparatus comprises: a clamp module, wherein said clamp module is configured to clamp a camshaft and drive the camshaft to be processed to rotate about its own axis; a movable grinding wheel module, wherein said movable grinding wheel module is configured to perform grinding processing on the camshaft; a lifting and moving nozzle module, wherein said lifting and moving nozzle module is configured to perform abrasive water jet polishing on the camshaft, and said lifting and moving nozzle module is configured to be displaceable in three orthogonal directions relative to said camshaft, so as to adjust and control the spatial position of said nozzle relative to the cam curved surface of said camshaft; a polishing liquid circulation system, wherein said polishing liquid circulation system is configured to supply polishing liquid to said lifting and moving nozzle module; a control module, wherein said control module is electrically connected to said clamp module, said movable grinding wheel module, said lifting and moving nozzle module and said polishing liquid circulation system respectively, so as to control the motions and working parameters of each module; Said movable grinding wheel module comprises a grinding wheel support plate, a grinding wheel transverse carriage, a grinding wheel guide rail, a grinding wheel slider, a grinding wheel slider connecting block, a No. 2 deep groove ball bearing, a No. 3 deep groove ball bearing, a grinding wheel shaft, a grinding wheel and a No. 1 servo electric cylinder; the cross-sectional shape of said grinding wheel support plate is T-shaped, and a plurality of cylindrical slide rails are provided in the middle of said grinding wheel support plate; said grinding wheel transverse carriage is inverted L-shaped, a lower end of said grinding wheel transverse carriage is provided with a plurality of cylindrical holes, each of said cylindrical holes is in sliding fit with each of said cylindrical slide rails of said grinding wheel support plate, a plurality of said grinding wheel guide rails are installed on an upper end of said grinding wheel transverse carriage, and said grinding wheel slider is slidably connected to said grinding wheel guide rail; said grinding wheel slider is connected to said No. 1 servo electric cylinder through said grinding wheel slider connecting block; an upper part of said grinding wheel slider is semicircular, two stepped holes with different sizes are provided at the center of said semicircle, and the two stepped holes with different sizes are respectively configured to install said No. 2 deep groove ball bearing and said No. 3 deep groove ball bearing; said grinding wheel shaft is installed at the central positions of said No. 2 deep groove ball bearing and said No. 3 deep groove ball bearing; said grinding wheel is installed on said grinding wheel shaft; During the idle travel or waiting time after the grinding processing of each cam surface of the camshaft by the movable grinding wheel module is completed, the lifting and moving nozzle module and the polishing liquid circulation system perform abrasive water jet polishing processing on the cam parts that have completed grinding.

2. The apparatus for grinding and polishing camshafts according to claim 1, characterized in that, Said apparatus further comprises: a bed module configured to carry other modules in said apparatus, said bed module comprises a bed, an inner wall of a rear end of said bed is provided with a multi-stage filtering structure configured to separate and filter a plurality of abrasive particles with different thicknesses and grinding chips, said multi-stage filtering structure is hourglass-shaped arranged vertically, an upper end of said multi-stage filtering structure is open and connected to a table surface of said bed, a plurality of layers of herringbone-stacked filtering inclined screens with different meshes are provided in a middle part of said multi-stage filtering structure, a filtering end of each layer of said filtering inclined screen is connected to an abrasive particle tube respectively, and said bed is provided with a plurality of layers of square-shaped concentration tanks sequentially surrounded from outside to inside at a lower end of said multi-stage filtering structure.

3. The apparatus for grinding and polishing camshafts according to claim 1, characterized in that, The clamping module includes a spindle drive module, which comprises a base plate, a bearing housing, a deep groove ball bearing (No. 1), a chuck body, jaws, a large pulley, a small pulley, a motor, and a motor pad. The motor pad and bearing housing are fixedly connected to the base plate. The motor is fixedly mounted on the motor pad, and its mounting height is the same as the center height of the chuck body. The chuck body is mounted on the bearing housing by the support of two deep groove ball bearings (No. 1). The chuck body has several grooves evenly distributed around its circumference, and each groove contains one jaw. The large pulley is mounted on the chuck body by a key connection, and the small pulley is mounted on the motor by a key connection. The mounting positions of the motor and the bearing housing ensure that the large pulley and the small pulley are in the same plane of motion.

4. The apparatus for grinding and polishing camshafts according to claim 1, characterized in that, The clamping module includes a movable center module, which comprises a center guide rail, a center slider, a center base plate, a center support seat, a deep groove ball bearing No. 4, a center, a cylinder connecting block, a cylinder, and a locking nut. Several fixedly spaced center sliders are slidably mounted on the center guide rail. The center base plate is mounted on the center slider. The center support seat is mounted in the middle of the center base plate. The center support seat is connected to the cylinder via the cylinder connecting block and the locking nut, and the upper part of the center support seat has a stepped through hole symmetrical in the axial section. Two deep groove ball bearings No. 4 are mounted at both ends of the stepped through hole. The center is mounted at the center of the deep groove ball bearing No.

4.

5. The apparatus for grinding and polishing camshafts according to claim 1, characterized in that, The lifting and moving nozzle module comprises a fixed frame, nozzle transverse moving guide rails, a nozzle transverse moving slider, a No. 3 servo electric cylinder, locking nuts, a lifting fixed plate, a No. 4 servo electric cylinder, a lifting plate, lifting guide columns, nozzle longitudinal moving guide rails, a nozzle longitudinal moving slider, a No. 5 servo electric cylinder, a No. 1 connecting pipeline, a nozzle, a water pump moving slider, a No. 1 water pump and a No. 2 connecting pipeline; a plurality of said nozzle transverse moving guide rails are installed on said fixed frame; said nozzle transverse moving slider is slidably installed on said nozzle transverse moving guide rails; said lifting fixed plate and a plurality of said lifting guide columns are fixedly installed on said nozzle transverse moving slider, and a convex end is arranged at the right side of said nozzle transverse moving slider, and said convex end is connected and fixed with said No. 3 servo electric cylinder through said locking nut; a stepped circle for lifting limiting is arranged above said lifting guide column; said No. 4 servo electric cylinder is fixedly installed on said lifting fixed plate; the movable end of said No. 4 servo electric cylinder is connected with said lifting plate; a plurality of said nozzle longitudinal moving guide rails are respectively installed at the front and rear ends of said lifting plate; said nozzle longitudinal moving slider is installed on said nozzle longitudinal moving guide rail at the front end; the top view of said nozzle longitudinal moving slider is in a "convex" shape, the protruding end is provided with a supporting circular hole with a certain height for supporting said No. 1 connecting pipeline, and the non-protruding part of the other end of said nozzle longitudinal moving slider is provided with a connecting hole with a certain height for connecting with said No. 5 servo electric cylinder; said water pump moving slider is installed on said nozzle longitudinal moving guide rail at the rear end; the top view of said water pump moving slider is in a "convex" shape, the protruding end of said water pump moving slider is provided with a semicircular hole with a certain height for supporting said No. 1 connecting pipeline, and a through hole for installing said No. 1 water pump is arranged in the middle of said water pump moving slider; the side through hole of said No. 1 water pump is connected with said No. 1 connecting pipeline, and the bottom through hole of said No. 1 water pump is connected with said No. 2 connecting pipeline; said No. 1 connecting pipeline is provided with two openings, one opening at one end is connected with said No. 1 water pump, and the other opening is connected with said nozzle.

6. The apparatus for grinding and polishing camshafts according to claim 2, characterized in that, The polishing liquid circulation system comprises a valve module, and said valve module comprises: a valve body, a gate plate, a No. 2 servo electric cylinder and locking nuts; a cylindrical through hole is arranged at the front end of said valve body, and a U-shaped groove is formed on the inner wall of the front end of said valve body; three cylindrical through holes with equal inner and outer diameters are arranged at the rear end of said valve body, and the middle part of said valve body is hollowed out; two small U-shaped grooves for matching and limiting with said gate plate are respectively formed at two ends of said U-shaped groove; a through hole is arranged in the middle of said gate plate, two symmetrically arranged convex cylindrical platforms are arranged at the front end of said gate plate and at a position tangent to said through hole, and a protruding cylindrical threaded hole is arranged at the right end of said gate plate; said gate plate is connected with said No. 2 servo electric cylinder through said threaded hole and said locking nut.

7. The apparatus for grinding and polishing camshafts according to claim 6, characterized in that, The polishing fluid circulation system includes a water tank module, which comprises: a water tank base, a water tank, a water pump 2, and a connecting pipe 3. The water tank base has a "T"-shaped cross-section and a rectangular opening in the middle. The water tank is a cuboid without a top cover, and a platform is located in the middle of the outer front side of the water tank. A cylindrical through hole for installing the water pump 2 is located directly above the platform. The water pump 2 is connected to the cylindrical through hole through the connecting pipe 3.

8. The apparatus for grinding and polishing camshafts according to claim 7, characterized in that, The multi-stage filtration structure includes a coarse abrasive tube, a medium abrasive tube, and a fine abrasive tube, all of which are connected to the valve module. After separation and filtration, the abrasive particles are driven by the flow of polishing fluid through the coarse, medium, and fine abrasive tubes connected to the valve module. Finally, under the action of the gate and servo cylinder 2, the three different coarse abrasive particles are sequentially transported to the polishing fluid circulation system, thereby achieving the effect of polishing fluid recycling.

9. A method for grinding and polishing a camshaft, characterized in that, The method, using the apparatus for grinding and polishing camshafts according to any one of claims 1-8, comprises the following steps: S1, The camshaft is clamped on the camshaft grinding and polishing device and driven to rotate; S2, using a moving grinding wheel module to grind each cam part of the camshaft; S3, Abrasive waterjet polishing is performed on the camshaft. The control module optimizes and controls the process parameters of the abrasive waterjet polishing process according to the NSGA-II multi-objective optimization algorithm, and selects the optimal process parameters as the control parameters of the abrasive waterjet polishing process. Process parameters include, but are not limited to: the distance between the nozzle and the camshaft of the lifting and moving nozzle module, the flatness of the nozzle opening, the spray angle, the spray pressure, and the polishing time of each abrasive grain; With the abrasive grains of fixed size, the optimization objective of the NSGA-II multi-objective optimization algorithm is to achieve the best balance between minimizing the surface roughness of the camshaft and minimizing the machining time of the camshaft. The NSGA-II multi-objective optimization algorithm execution steps include: S31, initialize an initial population containing several sets of existing process parameter combinations for abrasive waterjet polishing processes, ensuring that the parameter values ​​are within feasible ranges; S32, evaluate each individual in the population and calculate its corresponding optimization objective value; S33, perform non-dominated ranking of the population, divide individuals into different Pareto front levels, and calculate the crowding distance of each individual in its respective front; S34, based on the non-inferiority level and crowding distance of individuals, selects the best individuals to enter the next generation; S35, apply genetic operations such as crossover and mutation to generate new individuals in order to explore the parameter space; S36: Merge the parent and offspring populations and repeat steps such as non-dominated sorting, crowding distance calculation and selection until the set maximum number of iterations is reached and the termination condition is met. S37 outputs a solution set containing a set of Pareto optimal process parameters; wherein, each cam part of the camshaft is sequentially subjected to grinding and abrasive waterjet polishing; during the idle stroke or waiting time after the grinding of each cam surface of the camshaft is completed by the moving grinding wheel module, the lifting moving nozzle module and the polishing fluid circulation system perform abrasive waterjet polishing on the cam parts that have been ground, thereby improving production efficiency.

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