Device and method for grinding and polishing camshaft

Abstract

The invention provides a camshaft grinding and polishing device and method, and belongs to the technical field of mechanical precision machining. The device integrates a grinding wheel grinding process and an abrasive water jet polishing process, the polishing process is optimized through the control module on the basis of an NSGA-II multi-objective optimization algorithm, and the production requirements of high polishing efficiency and low surface roughness are met. A main body structure of the device comprises a lathe bed module, a main shaft driving module, a movable grinding wheel module, a movable center module, a lifting movable nozzle module and a polishing liquid circulating system. The main shaft driving module and the movable center module are arranged at the two ends of the lathe bed module correspondingly to cooperatively complete camshaft clamping and rotary driving. The movable grinding wheel module is provided with transverse and longitudinal sliding rails, and movable continuous machining is achieved; the lifting moving nozzle module and the valve module are linked to regulate and control polishing process parameters; and a three-stage filtering system is arranged in the lathe bed module to realize cyclic utilization of the polishing solution. Through process integration and algorithm optimization, the technical problems of low efficiency and difficult quality control in traditional step-by-step processing are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of precise machining of camshafts, and particularly to an apparatus and method for grinding and polishing a camshaft. Background Art

[0002] A camshaft is an important transmission control part in an engine, and its main function is to control the opening and closing of the engine valves. Specifically, during the rotation of the camshaft around its own axis, the cam part relies on its protruding curved surface to push open the valves, enabling gas to enter the combustion chamber and generating energy through the combined combustion with fuel; and the opening of the valves also requires the exhausted waste gas to be discharged. Therefore, the curvature accuracy of the cam part can directly affect the opening timing and height of the valves, thereby indirectly affecting the gas inflow and waste gas discharge volume during each valve opening.

[0003] Currently, the machining of the cam part of the camshaft is mainly divided into two processes: grinding and polishing. First, the grinding wheel rotates and moves along the radial direction of the camshaft to adapt to the curved surface shape of the camshaft, and rough grinding and fine grinding are performed on the cam surface; after the grinding wheel finishes grinding, a special polishing device is used for finishing machining. However, this step-by-step machining form has the following problems: 1. Long idle travel waiting time: The polishing process cannot be carried out until all the grinding processes of the cam part are completed.

[0004] 2. Difficulty in ensuring machining quality: The camshaft needs to be re-clamped on the polishing device, which may lead to new positioning errors.

[0005] 3. High cost of multiple machining devices: Currently, there are few machining devices for integrated grinding and polishing of camshafts, which requires two independent machining devices to meet the machining requirements, so the costs of purchasing equipment and maintenance are both increased.

[0006] 4. Difficulty in achieving the dual goals of efficiency and quality: The polishing process of the cam part depends on the processing experience of traditional operators, and it is difficult to perform optimization operations using automated equipment and the best combination of process parameters.

[0007] In summary, the existing technology still has problems such as low efficiency, difficult quality control, and high cost in the machining of camshafts. The present invention aims to provide a new technical solution to overcome the above-mentioned disadvantages of the existing technology. Summary of the Invention

[0008] In view of the above problems, the present invention provides an apparatus and method for grinding and polishing a camshaft. The present invention aims to be able to perform abrasive water jet polishing using the idle travel time after grinding under the condition of one-time clamping, thereby improving machining efficiency and product quality and reducing production costs.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows: This application provides a device for grinding and polishing a camshaft. The device includes: A fixture module for clamping the camshaft and driving the camshaft to be machined to rotate around its own axis; A moving grinding wheel module for grinding the camshaft; A lifting and moving nozzle module for abrasive water jet polishing of the camshaft. The lifting and moving nozzle module is configured to be displaceable 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 liquid circulation system for supplying polishing liquid to the lifting and moving nozzle module; A control module electrically connected to the fixture module, the moving grinding wheel module, the lifting and moving nozzle module, and the polishing liquid circulation system respectively to control the movement and working parameters of each module.

[0010] Preferably, the device further includes a bed module for carrying other modules in the device. The bed module includes a bed body. The inner wall at the rear end of the bed body is provided with a multi-stage filtering structure for separating and filtering abrasive particles and grinding chips of various different thicknesses. The multi-stage filtering structure is in the shape of an hourglass arranged vertically. The upper end of the multi-stage filtering structure is open and connected to the table surface of the bed body. The middle part of the multi-stage filtering structure is provided with several layers of filtering inclined meshes stacked in a "person" shape with different mesh numbers. The filtering ends of each layer of filtering inclined mesh are respectively connected with abrasive grain pipes. The bed body is provided with several layers of "mouth" - shaped concentrating grooves surrounded from the outside to the inside at the lower end of the multi-stage filtering structure.

[0011] Preferably, the fixture module includes a main shaft driving module. The main shaft driving module includes a bottom plate, a bearing seat, a deep groove ball bearing No. 1, a chuck body, a chuck jaw, a large pulley, a small pulley, a motor, and a motor pad; the motor pad and the bearing seat are fixedly connected to the bottom plate; the motor is fixedly installed on the motor pad, and the installation height of the motor is unified with the center height of the chuck body; the chuck body is installed on the bearing seat through the supporting action of two deep groove ball bearings No. 1. The chuck body is circumferentially provided with several chutes, and each of the several chutes is provided with a chuck jaw; the large pulley is installed on the chuck body in a key - connection form, and the small pulley is installed on the motor in a key - connection form; the installation positions of the motor and the bearing seat ensure that the large pulley and the small pulley are in the same moving plane.

[0012] Preferably, the movable grinding wheel module includes a grinding wheel support plate, a grinding wheel cross slide, a grinding wheel guide rail, a grinding wheel slider, a grinding wheel slider connection block, deep groove ball bearing No. 2, deep groove ball bearing No. 3, a grinding wheel shaft, a grinding wheel, and servo cylinder No. 1; the cross-sectional shape of the grinding wheel support plate is "T"-shaped, and several cylindrical slide rails are provided in the middle of the grinding wheel support plate; the grinding wheel cross slide is in an inverted "L" shape, and several cylindrical holes are provided at the lower end of the grinding wheel cross slide, and each cylindrical hole is slidably matched with each cylindrical slide rail of the grinding wheel support plate. Several grinding wheel guide rails are installed at the upper end of the grinding wheel cross slide, and the grinding wheel slider is slidably connected to the grinding wheel guide rail; the grinding wheel slider is connected to the servo cylinder No. 1 through the grinding wheel slider connection block; the upper part of the grinding wheel slider is semi-circular, and two stepped holes of different sizes are provided at the center of the semi-circular shape, and the two stepped holes of different sizes are respectively used for installing the deep groove ball bearing No. 2 and the deep groove ball bearing No. 3; the deep groove ball bearing No. 2 and the deep groove ball bearing No. 3 are installed at the central position of the grinding wheel shaft; the grinding wheel is installed on the grinding wheel shaft.

[0013] Preferably, the fixture module includes a movable center module, and the movable center module includes a center guide rail, a center slider, a center bottom plate, a center support seat, deep groove ball bearing No. 4, a center, a cylinder connection block, a cylinder, and a locking nut; several center sliders arranged at fixed intervals are slidably installed on the center guide rail; the center bottom plate is installed on the center slider; the center support seat is installed in the middle of the center bottom plate; the center support seat is connected to the cylinder through the cylinder connection block and the locking nut, and a stepped through hole symmetric in the axial cross-section is provided at the upper part of the center support seat; two deep groove ball bearings No. 4 are installed at both ends of the stepped through hole; the center is installed at the central part of the deep groove ball bearing No. 4.

[0014] Preferably, the lifting and moving nozzle module includes a fixed frame, a nozzle lateral movement guide rail, a nozzle lateral movement slider, servo cylinder No. 3, a locking nut, a lifting fixing plate, servo cylinder No. 4, a lifting plate, lifting guide columns, a nozzle longitudinal movement guide rail, a nozzle longitudinal movement slider, servo cylinder No. 5, connecting pipe No. 1, a nozzle, a water pump movement slider, water pump No. 1, and connecting pipe No. 2; a plurality of the nozzle lateral movement guide rails are installed on the fixed frame; the nozzle lateral movement slider is slidably installed on the nozzle lateral movement guide rail; the lifting fixing plate and a plurality of the lifting guide columns are fixedly installed on the nozzle lateral movement slider, and a convex end is arranged on the right side of the nozzle lateral movement slider, and the convex end is fixedly connected to the servo cylinder No. 3 through the locking nut; a stepped circle for lifting limit is arranged above the lifting guide column; the servo cylinder No. 4 is fixedly installed on the lifting fixing plate; the movable end of the servo cylinder No. 4 is connected to the lifting plate; a plurality of the nozzle longitudinal movement guide rails are installed at the front and rear ends of the lifting plate; the nozzle longitudinal movement slider is installed on the front-end nozzle longitudinal movement guide rail; the top view of the nozzle longitudinal movement slider is in a "convex" shape, and a supporting round hole with a certain height for supporting the connecting pipe No. 1 is arranged at the protruding end, and a connecting hole with a certain height for connecting to the servo cylinder No. 5 is arranged at the non-protruding part of the other end of the nozzle longitudinal movement slider; the water pump movement slider is installed on the rear-end nozzle longitudinal movement guide rail; the top view of the water pump movement slider is in a "convex" shape, a semi-circular hole with a certain height for supporting the connecting pipe No. 1 is arranged at the protruding end of the water pump movement slider, and a through hole for installing the water pump No. 1 is arranged in the middle of the water pump movement slider; the side through hole of the water pump No. 1 is connected to the connecting pipe No. 1, and the bottom through hole of the water pump No. 1 is connected to the connecting pipe No. 2; the connecting pipe No. 1 is provided with two openings, one opening is connected to the water pump No. 1, and the other end is connected to the nozzle.

[0015] Preferably, the polishing liquid circulation system includes a valve module, and the valve module includes: a valve body, a gate plate, servo cylinder No. 2, and a locking nut; a cylindrical through hole is arranged at the front end of the valve body, and a U-shaped groove is formed in the inner wall of the front end of the valve body; three cylindrical through holes with equal inner and outer diameters are arranged at the rear end of the valve body, and the middle of the valve body is hollowed out; a small U-shaped groove for cooperating with and limiting the gate plate is arranged at each of the two ends of the U-shaped groove; a through hole is arranged in the middle of the gate plate, two symmetrically arranged convex cylindrical columns are arranged at the front end of the gate plate and tangent to the through hole, and a protruding cylindrical threaded hole is arranged at the right end of the gate plate; the gate plate is connected to the servo cylinder No. 2 through the threaded hole and the locking nut.

[0016] Preferably, the polishing liquid circulation system includes a water tank module, and the water tank module includes: a water tank seat, a water tank, water pump No. 2 and connecting pipe No. 3; the cross-sectional shape of the water tank seat is a "T" shape, and a rectangular opening is provided in the middle of the water tank seat; the water tank is a rectangular parallelepiped without a top cover, and a platform is provided in the middle of the outer front end of the water tank, and a cylindrical through hole for installing the water pump No. 2 is provided directly above the platform; the water pump No. 2 is connected to the cylindrical through hole through the connecting pipe No. 3.

[0017] Preferably, the multi-stage filtration structure includes a coarse abrasive tube, a medium abrasive tube and a fine abrasive tube, and the coarse abrasive tube, the medium abrasive tube and the fine abrasive tube are all connected to the valve module; after the multi-stage filtration structure completes the separation filtration, each abrasive particle is driven by the flow of the polishing liquid, passes through the coarse abrasive tube, the medium abrasive tube and the fine abrasive tube connected to the valve module, and finally, under the action of the gate plate and servo electric cylinder No. 2, the three different coarse and fine abrasives are transported to the polishing liquid circulation system in turn, so as to achieve the effect of recycling and reuse of the polishing liquid.

[0018] The present application also provides a method for camshaft grinding and polishing, characterized in that, using the camshaft grinding and polishing device according to any one of claims 1 to 9, the method comprises the following steps: S1, clamping the camshaft on the camshaft grinding and polishing device and driving the camshaft to rotate; S2, grinding each cam part of the camshaft using a mobile grinding wheel module; S3, performing abrasive water jet polishing on the camshaft, the control module optimizes and regulates the process parameters of the abrasive water jet polishing process according to the NSGA-II multi-objective optimization algorithm, and selects the optimal process parameters as the control parameters of the abrasive water jet polishing process; Process parameters include but are not limited to: the distance between the nozzle of the lifting and moving nozzle module and the camshaft, the flatness of the nozzle opening, the injection angle, the injection pressure, and the polishing time of each abrasive grain; The coarseness of the abrasive particles is fixed, and the optimization goal 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 processing time of the camshaft; The NSGA-II multi-objective optimization algorithm execution steps include: S31, initializing an initial population including several groups of process parameter combinations of the existing abrasive water jet polishing process, ensuring that the parameter values ​​are within a feasible range; S32, evaluating each individual in the population and calculating its corresponding optimization target value; S33, sort the population in a non-inferior way, divide the individuals into different Pareto frontier levels, and calculate the crowding distance of each individual in the frontier to which it belongs; S34. Perform a selection operation based on the non-dominated rank and crowding distance of individuals, and preferably select excellent individuals to enter the next generation; S35. Apply genetic operations of crossover and mutation to generate new individuals to explore the parameter space; S36. Combine 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 satisfied; S37. Output a solution set containing a group of Pareto optimal process parameter combinations; wherein, the grinding process and abrasive water jet polishing process are sequentially performed on each cam part of the camshaft in turn; by using the moving grinding wheel module during the idle stroke or waiting time after the grinding process of each cam surface of the camshaft is completed, the lifting and moving nozzle module and the polishing liquid circulation system perform abrasive water jet polishing on the cam parts that have completed grinding, thereby improving production efficiency.

[0019] The beneficial effects of the present invention are as follows: 1. Improve processing efficiency: Under one clamping, the grinding and polishing processes can be sequentially completed for each cam part of the camshaft one by one, without generating positioning errors caused by secondary clamping, thus shortening the processing time.

[0020] 2. Achieve the dual goals of efficiency and quality: The integrated processing reduces the switching time between different processes, and combines the NSGA-II algorithm to optimize the polishing process, enabling stable acquisition of higher surface accuracy and lower surface roughness, and improving the product qualification rate.

[0021] 3. Optimize processing performance: By utilizing the global optimization ability of the NSGA-II algorithm, the optimal process parameter combination can be found among multiple conflicting goals (such as efficiency and quality), achieving the best processing effect that is difficult to achieve by traditional methods.

[0022] 4. Save costs and space: The integrated device reduces the number of equipment and economic costs. Description of the Drawings

[0023] Figure 1 is the overall schematic diagram of a device and method for grinding and polishing a camshaft according to the present invention.

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

[0025] Figure 3 is the present invention Figure 2 The sectional schematic diagram of the fan blade in the closed state at A-A in the present invention.

[0026] Figure 4 is the present invention Figure 3 The enlarged view of the fan blade in the open state at A in the present invention.

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

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

[0029] Figure 7 is an overall schematic diagram of the moving center module of the present invention.

[0030] Figure 8 is the present invention Figure 7 in the sectional schematic diagram of the center mounting method.

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

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

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

[0034] Figure 12 is the sectional schematic of the valve module of the present invention Figure One .

[0035] Figure 13 is the sectional schematic of the valve module of the present invention Figure Two .

[0036] Figure 14 is the sectional schematic of the valve module of the present invention Figure Three .

[0037] Figure 15 is the sectional schematic of the valve module of the present invention Figure Four .

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

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

[0040] Figure 18 is a schematic diagram of the working process of the present invention.

[0041] Figure 19 is a partial enlarged view of the present invention in the actual working state.

[0042] Figure 20 is a flowchart of the NSGA-II multi-objective optimization algorithm applied by the present invention.

[0043] Figure 21It is the result graph of the Pareto optimal solution set of the NSGA-II multi-objective optimization algorithm applied in the present invention.

[0044] In the figure: 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 pipeline 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 seat, 0203 - Deep groove ball 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 cross 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 cylinder No. 1, 0401 - Center guide rail, 0402 - Center slider, 0403 - Center base plate, 0404 - Center support seat, 0405 - Deep groove ball bearing No. 4, 0406 - Center limit cover, 0407 - Center, 0408 - Cylinder connecting block, 0409 - Cylinder, 0410 - Locking nut, 0501 - Fixed mounting platform, 0502 - Nozzle cross movement guide rail, 0503 - Nozzle cross movement slider, 0504 - Servo cylinder No. 3, 0505 - Lifting fixed plate, 0506 - Servo cylinder No. 4, 0507 - Lifting plate, 0508 - Lifting guide post, 0509 - Nozzle longitudinal movement guide rail, 0510 - Nozzle longitudinal movement slider, 0511 - Servo cylinder No. 5, 0512 - Connecting pipeline No. 1, 0513 - Nozzle, 0514 - Water pump movement slider, 0515 - Water pump No. 1, 0516 - Connecting pipeline No. 2, 0601 - Valve body, 0602 - Gate plate, 0603 - Servo cylinder No. 2, 0701 - Water tank seat, 0702 - Water tank, 0703 - Water pump No. 2, 0704 - Connecting pipeline No. 3. Detailed implementation manners

[0045] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific examples and attached Figure 1 to attached Figure 21 The present invention will be further described in detail. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concept of the present invention.

[0046] As Figure 1 andFigure 17 As shown in the figure, the present invention provides a device for grinding and polishing a camshaft, which includes: A bed module 01 for carrying other modules of the device.

[0047] A fixture module for clamping the camshaft 09 and driving the camshaft 09 to be machined to rotate around its own axis. The fixture module includes a main shaft drive module 02 and a movable center module 04. The main shaft drive module 02 and the movable center module 04 are respectively installed on both sides of the bed module 01 and cooperate to clamp and drive the camshaft 09 to be machined to rotate around its axis.

[0048] A movable grinding wheel module 03 for grinding the camshaft 09.

[0049] A lifting and movable nozzle module 05 installed on the bed module 01 for abrasive water jet polishing of the cam surface of the camshaft.

[0050] A polishing liquid circulation system, which includes a valve module 06, a water tank module 07, a connecting pipeline No. 4 08 and a multi-stage filtering structure provided inside the bed module 01, for providing controlled polishing liquid to the lifting and movable nozzle module 05 and being controlled by a control module 10. In this application, the multi-stage filtering structure is a three-stage filtering system.

[0051] A control module 10, which is electrically connected to the main shaft drive module 02, the movable center module 04, the movable grinding wheel module 03, the lifting and movable nozzle module and the polishing liquid circulation system respectively to control the movement and working parameters of each module.

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

[0053] A "hourglass-shaped" three-stage filtering system is provided inside the bed 0101.

[0054] The upper part of the three-stage filtering system is an inverted conical funnel shape, in which six fan blades 0106 in the closed state and a three-layer filtering inclined net structure stacked in a "human" shape are installed in the middle. Its lower part is conical and is connected to a four-layer "mouth"-shaped concentrated groove surrounded from the outside to the inside at the bottom of the bed.

[0055] The centralized tank is divided into four volume tanks. A hole is opened in the middle tank wall of the innermost volume tank for installing the fine abrasive tube 0102. Two holes are opened in the second volume tank from the inside out. One hole is for the fine abrasive tube 0102 to pass through, and the other hole is for installing the medium abrasive tube 0103. Three holes are opened in the third volume tank from the inside out. Two of the holes are for the fine abrasive tube 0102 and the medium abrasive tube 0103 to pass through, and the third hole is for installing the coarse abrasive tube 0104. Four holes are opened in the outermost volume tank. Three of the holes are for the fine abrasive tube 0102, the medium abrasive tube 0103, and the coarse abrasive tube 0104 to pass through, and the side wall is set as the fourth hole for installing the chip removal tube 0105.

[0056] As Figure 5 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, a chuck jaw 0205, a large pulley 0206, a small pulley 0207, a motor 0208, and a motor pad 0209.

[0057] Three circumferentially evenly distributed chuck jaws 0205 are installed on the chuck body 0204, and the three chuck jaws 0205 are used to clamp the camshaft 09. Through the supporting action of two deep groove ball bearings No. 1 0203 of the same model, it is installed in the central hole of the bearing seat 0202. The height of the central hole of the bearing seat 0202 is the same as the rotation center height of the motor 0208 installed on the pad 0209, so that the large pulley 0206 and the small pulley 0207 are at the same height in the same plane to ensure the transmission stability.

[0058] As Figure 6 shown, the moving grinding wheel module 03 includes a grinding wheel support plate 0301, a grinding wheel cross 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 cylinder No. 1 0310.

[0059] The cross-sectional shape of the grinding wheel support plate 0301 is "T"-shaped, and four equal-diameter and symmetrically arranged cylindrical guide rail structures are provided in the middle. The grinding wheel cross slide 0302 is installed on the grinding wheel support plate 0301 through four equal-diameter hole structures provided at the bottom and can move horizontally along the guide rail structure.

[0060] Two grinding wheel guide rails 0303 are installed at one end of the grinding wheel cross slide 0302. The servo cylinder No. 1 0310 is installed at the other end of the grinding wheel cross slide 0302. The grinding wheel slider 0304 is installed on the grinding wheel guide rail 0303, connected to the servo cylinder No. 1 0310 through the grinding wheel slider connecting block 0305, and realizes longitudinal displacement through the telescopic action of the servo cylinder No. 1 0310.

[0061] The deep groove ball bearing No. 2 (0306) and the deep groove ball bearing No. 3 (0307) are both embedded in the central hole of the grinding wheel slider 0304 in the form of stepped holes. The grinding wheel shaft 0308 is installed on the deep groove ball bearing No. 2 (0306) and the deep groove ball bearing No. 3 (0307). The grinding wheel 0309 is installed in the middle position of the grinding wheel shaft 0308, and its thickness can cover the width range of the cam part of the camshaft 09.

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

[0063] As Figure 7 and Figure 8 shown, the moving 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 connection block 0408, a cylinder 0409, and a locking nut 0410.

[0064] Two center sliders 0402 are installed on the center guide rail 0401. The center base plate 0403 is installed on the four center sliders 0402 and can achieve lateral displacement.

[0065] The center support seat 0404 is installed above the middle of the center base plate 0403 and is connected to the cylinder 0409 through the pre-tightening action of the cylinder connection block 0408 and the locking nut 0410. The cylinder 0409 is installed on the machine tool bed 0101. The deep groove ball bearing No. 4 (0405) is embedded in the hole through the symmetric stepped hole structure provided inside the center support seat 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, and the convex circular structure on one side of it plays a longitudinal installation limiting role for both the center 0407 and the deep groove ball bearing No. 4 (0405).

[0067] As Figure 9 and Figure 10 shown, the lifting and moving nozzle module 05 includes a fixed frame 0501, a nozzle lateral movement guide rail 0502, a nozzle lateral movement slider 0503, a servo cylinder No. 3 (0504), a lifting fixed plate 0505, a servo cylinder No. 4 (0506), a lifting plate 0507, a lifting guide post 0508, a nozzle longitudinal movement guide rail 0509, a nozzle longitudinal movement slider 0510, a servo cylinder No. 5 (0511), a connecting pipe No. 1 (0512), a nozzle 0513, a water pump moving slider 0514, a water pump No. 1 (0515), and a connecting pipe No. 2 (0516).

[0068] Both ends of the fixed mount 0501 adopt a stepped design and can be directly installed on the bed body 0101 through the stepped design.

[0069] The nozzle lateral movement guide rail 0502 is installed on the fixed mount 0501. The nozzle lateral movement slider 0503 is installed on the nozzle lateral movement guide rail 0502. One end of it is provided with a protruding connection hole structure, and each of its four corners is provided with a concave hole structure. The servo electric cylinder No. 3 0504 is installed on the bed body 0101 and is connected to the nozzle lateral movement slider 0503 through the connection hole structure to achieve lateral displacement control.

[0070] One end of the lifting guide post 0508 is inserted into the nozzle lateral movement slider 0503 through the concave hole structure and is limited by four triangular reinforcing rib structures. The other end is provided with a collar structure. The lifting plate 0507 is connected and matched with the lifting guide post 0508 through the hole positions arranged at its four corners. One end of it is provided with a rectangular opening, the other end is provided with a convex hole structure below, and its lower surface is provided with three strip-shaped reinforcing rib structures.

[0071] The lifting fixed plate 0505 is vertically installed on the nozzle lateral movement slider 0503. The servo electric cylinder No. 4 0506 is vertically installed on the lifting fixed plate 0505 and is connected to the lifting plate 0507 through the convex hole structure to achieve lifting control. The nozzle longitudinal movement guide rails 0509 are respectively installed at both ends of the lifting plate 0507. One end is installed with a nozzle longitudinal movement slider 0510, and the other end is installed with a water pump movement slider 0514. One end of the nozzle longitudinal movement slider 0510 is provided with a through hole structure, and the other end is provided with a blind connection hole structure. One end of the water pump movement slider 0514 is provided with a semi-circular through hole structure, and the other end is provided with an opening structure. The servo electric cylinder No. 5 0511 is connected to the nozzle longitudinal movement slider 0510 through the blind connection hole structure and is installed on the lifting plate 0507.

[0072] Both ends of the connecting pipeline No. 1 0512 are respectively installed on the through hole structure at one end of the nozzle longitudinal movement slider 0510 and the semi-circular through hole structure at one end of the water pump movement slider 0514. The nozzle 0513 is fixedly connected to one end of the connecting pipeline No. 1 0512. The side through hole of the water pump No. 1 0515 is connected to the other end of the connecting pipeline No. 1 0512 and is fixedly installed on the opening structure of the water pump movement slider 0514. The connecting pipeline No. 2 0516 is fixed in the bottom through hole of the water pump No. 1 0515.

[0073] As Figures 11 to 15 shown, the valve module 06 includes a valve body 0601, a gate plate 0602, and a servo electric cylinder No. 2 0603.

[0074] The valve body 0601 is generally in the shape of a cuboid. One side is designed with a cylindrical through-hole, and the other side is designed with three cylindrical through-holes. The middle part of the valve body 0601 is a through square hole and is connected to the cylindrical holes. The inner surface of the valve body 0601 connected to a cylindrical through-hole is designed with a U-shaped groove. There is a small U-shaped groove at each end of the U-shaped groove. The gate plate 0602 is a cuboid, and a circular through-hole is opened in the center. On one side of the outer end of the circular through-hole, there are two convex cylinders with the same center height as the cylindrical through-hole. One end of the gate plate 0602 is provided with a connection hole. The connection hole is connected to the servo electric cylinder No. 2 0603.

[0075] As Figure 16 shown, the water tank module 07 includes a water tank base 0701, a water tank 0702, a water pump No. 2 0703, and a connecting pipeline No. 3 0704.

[0076] The water tank base 0701 has a structure similar to that of the grinding wheel support plate 0301, except that the middle part is a rectangular opening, and there are two connection hole positions at each end. The water tank 0702 is positioned and installed on the water tank base 0701 through the connection hole positions, and a stepped structure is provided on one side. The water pump No. 2 0703 is installed on the stepped structure of the water tank 0702. One end of the connecting pipeline No. 3 0704 is connected to the water pump No. 2 0703, and the other end is connected to the water tank 0702.

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

[0078] As Figure 20 shown, the control module 10 is configured to optimize and regulate the previous key test process parameters of the abrasive water jet 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, the injection angle , the injection pressure P (regulated by controlling the water pump No. 1 0515), and the polishing time of each abrasive grain (t_c, t_m, t_f). Among them, the fineness degree s of the abrasive grains is fixed, and the optimization goal of the algorithm aims to achieve the best balance between minimizing the surface roughness Ra and minimizing the processing time T.

[0080] In the present invention, the execution process of the NSGA-II algorithm is as follows: First, initialize an initial population containing 20 sets of existing polishing process parameter combinations (i.e., individuals), and ensure that the parameter values are within the feasible range.

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

[0082] Then, the population is sorted non-inferiorly, the individuals are divided into different Pareto front levels, and the crowding distance of each individual in the front to which it belongs is calculated.

[0083] Subsequently, selection operations are performed based on the non-inferior grades and crowding distances of the individuals, and excellent individuals are selected to enter 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-inferiority sorting, crowding distance calculation, and selection are repeated until the termination condition is met (the set maximum number of iterations is reached).

[0085] The output of the algorithm is a solution set containing a set of Pareto optimal parameter combinations.

[0086] In the present invention, the control module 10 determines a set of optimal polishing process parameter combinations 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 point between efficiency and quality), and uses it as the control target value of the actual polishing process.

[0087] For example, the control module 10 outputs a control signal to the servo electric cylinder (such as servo electric cylinder No. 3 0504, etc.) in the lifting and moving nozzle module 05 according to the selected optimal speed parameters, so as to control the nozzle to move accurately. According to the selected optimal pressure and flow parameters, the control signal is output to the pump (such as Figure 17 The water pump No. 1 in the polishing machine is used to adjust the supply state of the polishing liquid. Through this intelligent optimization control based on the NSGA-II algorithm, it can ensure that the polishing process always runs in a state close to the optimal state, so as to stably obtain efficient and high-quality polishing effects. The various parameters and test results of the polishing test are shown in Table 1. The optimal solution combination of Pareto parameters and the empirical parameter combination are shown in Table 2.

[0088] Table 1 Test parameters and results Table 2 Pareto parameter optimal solution combination and empirical parameter combination In the present invention, the hole size of the filtering inclined mesh of the three-stage filtering system of the bed 0101 only indicates that the hole size of each stage decreases step by step downward, and is not the actual size. It needs to be determined according to the coarseness of the specific coarse, medium and fine abrasive particles.

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

[0090] In the present invention, the nozzle 0513 mainly realizes displacements in three orthogonal directions through the servo cylinder No. 3 0504, the servo cylinder No. 4 0506, and the servo cylinder No. 5 0511, so as to control its spatial distance relative to the cam surface of the camshaft 09.

[0091] In the present invention, the gate plate 0602 realizes the connection of different hole positions of the valve body 0601 through the servo cylinder No. 2 0602.

[0092] In the present invention, the length, width, and height dimensions of the water tank 0702 include but are not limited to the displacement strokes of the nozzle 0513 in three orthogonal directions, so as to ensure that the water pump No. 1 can continuously draw the polishing liquid for polishing.

[0093] When production starts, first, the corresponding abrasive grains and polishing liquid are pre-injected into the respective volume tanks of the three-stage filtration system of the bed 0101, and the camshaft 09 is fixed to the device through the main shaft drive module 02 and the moving center point module 04. Then, the moving grinding wheel module 03 is enabled to perform a grinding process on the cam surface of the camshaft 09. When the grinding wheel 0309 grinds the next cam surface, the lifting and moving nozzle module 05 and the polishing liquid circulation system are enabled to perform a polishing process on the cam surface of the camshaft 09 (as Figure 19 shown). In the default state, the gate plate 0602 is first connected to the coarse abrasive grain pipe 0104. The polishing liquid therein is transported to the water tank 0702 through the suction of the water pump No. 2, passing through the connecting pipe No. 4 08 and the connecting pipe No. 3 0704, and then by the suction of the water pump No. 1 0515, flowing through the connecting pipe No. 1 0512, and being sprayed onto the cam surface of the camshaft 09 through the nozzle 0513. When the polishing liquid is used, it will flow back and pass through the three-stage filtration system. The uppermost filter inclined net of the system will first screen out the coarsest chips, and the chips will be discharged from the device through the chip discharge pipe 0105. The system will then gradually screen out the coarse, medium, and fine abrasive grains into the corresponding volume tanks, and then be transported to the valve module 06 through the three abrasive grain pipes, and this cycle will repeat. When different degrees of polishing are required, the servo cylinder No. 2 0603 will control the central through hole of the gate plate 0602 to communicate with different abrasive grain pipes, so as to transport the polishing liquid with different abrasive grains.

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

[0095] The above embodiments are only preferred implementation schemes of the present invention, and do not limit the technical solutions of the present invention. Any technical solution that can be achieved on the basis of the above embodiments without creative labor shall be regarded as falling within the scope of the patent rights of the present invention.

Claims

1. An apparatus for grinding and polishing a camshaft, characterized in that, The device includes: a fixture module configured to clamp a camshaft and drive the camshaft to be machined to rotate about its own axis; a moving grinding wheel module configured to perform grinding on the camshaft; a lifting and moving nozzle module configured to perform abrasive water jet polishing on the camshaft, the lifting and moving nozzle module being configured to be displaceable 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 liquid circulation system configured to supply polishing liquid to the lifting and moving nozzle module; a control module electrically connected to the fixture module, the moving grinding wheel module, the lifting and moving nozzle module, and the polishing liquid circulation system respectively to control the movement and working parameters of each module.

2. The device for camshaft grinding and polishing according to claim 1, characterized in that, The device further includes a bed module for carrying other modules in the device. The bed module includes a bed body. A multi-stage filtering structure for separating and filtering abrasive particles and grinding chips of various different thicknesses is provided on the inner wall at the rear end of the bed body. The multi-stage filtering structure is in the shape of an hourglass arranged vertically. The upper end of the multi-stage filtering structure is open and connected to the table surface of the bed body. In the middle of the multi-stage filtering structure, there are several layers of filtering inclined meshes stacked in a "person" shape with different mesh numbers. The filtering ends of each layer of filtering inclined mesh are respectively connected with abrasive grain pipes. The bed body is provided with several layers of "mouth" - shaped concentrated grooves surrounded from the outside to the inside at the lower end of the multi-stage filtering structure.

3. The device for grinding and polishing a camshaft according to claim 1, characterized in that, The fixture module includes a main shaft driving module. The main shaft driving module includes a bottom plate, a bearing seat, a deep groove ball bearing No. 1, a chuck body, a chuck jaw, a large pulley, a small pulley, a motor, and a motor mounting block. The motor mounting block and the bearing seat are fixedly connected to the bottom plate. The motor is fixedly installed on the motor mounting block, and the installation height of the motor is unified with the center height of the chuck body. The chuck body is mounted on the bearing seat through the supporting action of two deep groove ball bearings No.

1. A plurality of sliding grooves are circumferentially distributed on the chuck body, and each of the plurality of sliding grooves is provided with a chuck jaw. The large pulley is mounted on the chuck body in a key - connection form, and the small pulley is mounted on the motor in a key - connection form. The installation positions of the motor and the bearing seat ensure that the large pulley and the small pulley are in the same moving plane.

4. The device for grinding and polishing a camshaft according to claim 1, characterized in that, The mobile grinding wheel module includes a grinding wheel support plate, a grinding wheel cross slide, a grinding wheel guide rail, a grinding wheel slider, a grinding wheel slider connecting block, deep groove ball bearing No. 2, deep groove ball bearing No. 3, a grinding wheel shaft, a grinding wheel, and servo cylinder No. 1; the cross-sectional shape of the grinding wheel support plate is "T"-shaped, and several cylindrical slide rails are provided in the middle of the grinding wheel support plate; the grinding wheel cross slide is in an inverted "L" shape, and several cylindrical holes are provided at the lower end of the grinding wheel cross slide, and each cylindrical hole is slidably matched with each cylindrical slide rail of the grinding wheel support plate. Several grinding wheel guide rails are installed at the upper end of the grinding wheel cross slide, and the grinding wheel slider is slidably connected to the grinding wheel guide rail; the grinding wheel slider is connected to the servo cylinder No. 1 through the grinding wheel slider connecting block; the upper part of the grinding wheel slider is a semi-circle, and two stepped holes of different sizes are provided at the center of the semi-circle, and the two stepped holes of different sizes are respectively used for installing the deep groove ball bearing No. 2 and the deep groove ball bearing No. 3; the deep groove ball bearing No. 2 and the deep groove ball bearing No. 3 are installed at the central position of the grinding wheel shaft; the grinding wheel is installed on the grinding wheel shaft.

5. The device for grinding and polishing a camshaft according to claim 1, characterized in that, The fixture module includes a mobile center module, and the mobile center module includes a center guide rail, a center slider, a center bottom plate, a center support seat, deep groove ball bearing No. 4, a center, a cylinder connecting block, a cylinder, and a locking nut; several center sliders with fixed arrangement intervals are slidably installed on the center guide rail; the center bottom plate is installed on the center slider; the center support seat is installed in the middle of the center bottom plate; the center support seat is connected to the cylinder through the cylinder connecting block and the locking nut, and a stepped through hole symmetric in the axial cross-section is provided at the upper part of the center support seat; two deep groove ball bearings No. 4 are installed at both ends of the stepped through hole; the center is installed at the central part of the deep groove ball bearing No.

4.

6. The device for grinding and polishing a camshaft according to claim 1, characterized in that, The lifting and moving nozzle module includes a fixed mount, a nozzle lateral movement guide rail, a nozzle lateral movement slider, servo cylinder No. 3, a locking nut, a lifting fixed plate, servo cylinder No. 4, a lifting plate, lifting guide columns, a nozzle longitudinal movement guide rail, a nozzle longitudinal movement slider, servo cylinder No. 5, connecting pipe No. 1, a nozzle, a water pump movement slider, water pump No. 1, and connecting pipe No. 2; several of the nozzle lateral movement guide rails are installed on the fixed mount; the nozzle lateral movement slider is slidably installed on the nozzle lateral movement guide rail; the lifting fixed plate and several of the lifting guide columns are fixedly installed on the nozzle lateral movement slider, and a convex end is provided on the right side of the nozzle lateral movement slider, and the convex end is fixedly connected to the servo cylinder No. 3 through the locking nut; a stepped circle for lifting limit is provided above the lifting guide column; the servo cylinder No. 4 is fixedly installed on the lifting fixed plate; the movable end of the servo cylinder No. 4 is connected to the lifting plate; several of the nozzle longitudinal movement guide rails are installed at the front and rear ends of the lifting plate; the nozzle longitudinal movement slider is installed on the front-end nozzle longitudinal movement guide rail; the top view of the nozzle longitudinal movement slider is in a "convex" shape, and a supporting round hole with a certain height for supporting the connecting pipe No. 1 is provided at the protruding end, and a connecting hole with a certain height for connecting to the servo cylinder No. 5 is provided at the non-protruding part of the other end of the nozzle longitudinal movement slider; the water pump movement slider is installed on the rear-end nozzle longitudinal movement guide rail; the top view of the water pump movement slider is in a "convex" shape, a semi-circular hole with a certain height for supporting the connecting pipe No. 1 is provided at the protruding end of the water pump movement slider, and a through hole for installing the water pump No. 1 is provided in the middle of the water pump movement slider; the side through hole of the water pump No. 1 is connected to the connecting pipe No. 1, and the bottom through hole of the water pump No. 1 is connected to the connecting pipe No. 2; the connecting pipe No. 1 has two openings, one end opening is connected to the water pump No. 1, and the other end is connected to the nozzle.

7. The device for camshaft grinding and polishing according to claim 2, characterized in that, The polishing liquid circulation system includes a valve module, and the valve module includes: a valve body, a gate plate, servo cylinder No. 2, and a locking nut; a cylindrical through hole is provided at the front end of the valve body, and a U-shaped groove is opened on the inner wall of the front end of the valve body; three cylindrical through holes with equal inner and outer diameters are provided at the rear end of the valve body, and the middle of the valve body is hollowed out; a small U-shaped groove for cooperating with the gate plate for limit is opened at each end of the U-shaped groove; a through hole is provided in the middle of the gate plate, two symmetrically arranged convex cylindrical columns are provided at the front end of the gate plate and tangent to the through hole, and a protruding cylindrical threaded hole is provided at the right end of the gate plate; the gate plate is connected to the servo cylinder No. 2 through the threaded hole and the locking nut.

8. The device for camshaft grinding and polishing according to claim 7, characterized in that, The polishing liquid circulation system includes a water tank module, which includes: a water tank seat, a water tank, water pump No. 2 and a connecting pipe No. 3; the cross-sectional shape of the water tank seat is a "T" shape, and a rectangular opening is provided in the middle of the water tank seat; the water tank is a rectangular parallelepiped without a top cover, and a platform is provided in the middle of the outer front end of the water tank, and a cylindrical through hole for installing the water pump No. 2 is provided directly above the platform; the water pump No. 2 is connected to the cylindrical through hole via the connecting pipe No.

3.

9. The device for grinding and polishing a camshaft according to claim 8, characterized in that, characterized in that, The multi-stage filtering structure includes a coarse abrasive tube, a medium abrasive tube and a fine abrasive tube, and the coarse abrasive tube, the medium abrasive tube and the fine abrasive tube are all connected to the valve module; after the multi-stage filtering structure completes the separation and filtration, each abrasive particle is driven by the flow of the polishing liquid, passes through the coarse abrasive tube, the medium abrasive tube and the fine abrasive tube connected to the valve module, and finally, under the action of the gate plate and the servo electric cylinder No. 2, the three abrasive particles of different coarseness and fineness are transported to the polishing liquid circulation system in turn, so as to achieve the effect of recycling and reusing the polishing liquid.

10. A method for grinding and polishing a camshaft, characterized in that, Using the camshaft grinding and polishing device according to any one of claims 1 to 9, the method comprises the following steps: S1, clamping the camshaft on the camshaft grinding and polishing device and driving the camshaft to rotate; S2, grinding each cam part of the camshaft using a mobile grinding wheel module; S3, performing abrasive water jet polishing on the camshaft, the control module optimizes and regulates the process parameters of the abrasive water jet polishing process according to the NSGA-II multi-objective optimization algorithm, and selects the optimal process parameters as the control parameters of the abrasive water jet polishing process; Process parameters include but are not limited to: the distance between the nozzle of the lifting and moving nozzle module and the camshaft, the flatness of the nozzle opening, the injection angle, the injection pressure, and the polishing time of each abrasive grain; The coarseness of the abrasive particles is fixed, and the optimization goal 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 processing time of the camshaft; The NSGA-II multi-objective optimization algorithm execution steps include: S31, initializing an initial population including several groups of process parameter combinations of the existing abrasive water jet polishing process, ensuring that the parameter values ​​are within a feasible range; S32, evaluating each individual in the population and calculating its corresponding optimization target value; S33, sort the population in a non-inferior way, divide the individuals into different Pareto frontier levels, and calculate the crowding distance of each individual in the frontier to which it belongs; S34, perform selection operations based on the non-inferior grades and crowding distances of the individuals, and select the best individuals to enter the next generation; S35, applying genetic operations of crossover and mutation to generate new individuals to explore the parameter space; S36, merging the parent and child populations, and repeating the steps of non-inferiority sorting, crowding distance calculation, and selection until the set maximum number of iterations is reached and the termination condition is met; S37, output a solution set containing a group of Pareto optimal process parameter combinations; wherein, each cam part of the camshaft is successively and alternately subjected to grinding and abrasive water jet polishing; by using the moving grinding wheel module, during the idle stroke or waiting time after the grinding of each cam surface of the camshaft is completed, the lifting and moving nozzle module and the polishing liquid circulation system perform abrasive water jet polishing on the cam part that has been ground, thereby improving production efficiency.

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