Three-axis three-phase speed-changing ultra-precision micro-ball grinding and polishing device and grinding and polishing method

Abstract

The present invention proposes a three-axis three-phase speed-changing ultra-precision micro-ball grinding and polishing device and a grinding and polishing method, belonging to the technical field of high-precision spherical part processing. The present invention adjusts three groups of servo grinding head assemblies so that the output axes (axis one, axis two and axis three) of the three groups of servo grinding head assemblies intersect at the center of the processed sphere, thereby improving the alignment accuracy of the three groups of servo grinding head assemblies relative to the center of the ultra-precision micro-ball; at the same time, the output axes of the three groups of servo grinding head assemblies are controlled to rotate at a sinusoidal speed, thereby ensuring that the motion trajectories formed by the three groups of servo grinding head assemblies are evenly distributed on the surface of the processed sphere and can completely cover the surface of the processed sphere, thereby avoiding the slipping of ultra-precision micro-balls during the processing process and ensuring the stability of the ultra-precision micro-ball processing process.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-precision spherical parts processing, and relates to the grinding and polishing technology of ultra-precision microspheres. Specifically, it is a three-axis three-phase variable speed ultra-precision microsphere grinding and polishing device and grinding and polishing method. It is intended to grind and polish ultra-precision microspheres formed from specific materials (optical glass, rare metals, single crystal silicon, etc.), and is particularly suitable for the processing of single pieces, small batches, and non-standard ultra-precision microspheres. Background Art

[0002] Ultra-precision microspheres, tiny spheres with diameters ranging from 0.3mm to 3mm, are essential components commonly used in modern scientific experiments, precision instruments, and medical equipment. Processing of ultra-precision microspheres places extremely high demands on machining accuracy, roundness, and surface roughness.

[0003] Ultra-precision microspheres are characterized by their small size and often non-standard specifications, with varying specifications across different industries. They are often made from specialized materials, such as single-crystal silicon, optical glass, hard and brittle materials (such as silicon nitride, silicon carbide, and zirconium oxide), and rare metals (such as beryllium, niobium, rhodium, and titanium). Consequently, ultra-precision microspheres are typically produced in single pieces and small batches, making them impractical to process using conventional disc grinding and polishing methods.

[0004] In the existing technology, a four-axis ultra-precision grinding and polishing device is used to grind and polish ultra-precision microspheres. However, this device is only suitable for processing spheres with a diameter of more than 3 mm. For spheres with a diameter of less than 3 mm, due to their small size, it is difficult to keep the four axes stably aligned with the center of the sphere during grinding and polishing using the four-axis ultra-precision grinding and polishing device, resulting in the ultra-precision microspheres easily slipping during the processing process and the process state being unstable. Summary of the Invention

[0005] As described in the above background technology, in the existing technology, when grinding and polishing spheres with a diameter of less than 3 mm, it is difficult for the four axes of the grinding device to keep them stably aligned with the center of the sphere, and there is a technical problem that ultra-precision microspheres are prone to slipping during the processing. To address this technical problem, the present invention proposes a three-axis three-phase variable speed ultra-precision microsphere grinding and polishing device and a grinding and polishing method.

[0006] The present invention adjusts the three servo grinding head assemblies so that their output axes (axes 1, 2, and 3) intersect at the center of the sphere being machined. The output axes are then controlled to rotate sinusoidally. This ensures that the motion paths formed by the three servo grinding head assemblies are evenly distributed across the surface of the machined sphere and completely cover it, preventing the ultra-precision microspheres from slipping during machining. While complying with the grinding and polishing mechanisms of ultra-precision microspheres, the alignment accuracy of the three servo grinding head assemblies relative to the center of the ultra-precision microspheres is improved.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention comprises a ball clamping and positioning platform and three groups of servo grinding head assemblies distributed in an annular array on the periphery of the ball clamping and positioning platform;

[0009] The sphere clamping and positioning platform is used to place the sphere to be processed and adjust the position of the sphere to be processed to be on the same horizontal plane as the output shafts of the three sets of servo grinding head assemblies;

[0010] The phase difference between the three groups of servo grinding head assemblies is 120°, and the output shafts of the three groups of servo grinding head assemblies intersect at the center of the processed sphere and rotate at variable speeds according to a sinusoidal law; during the grinding and polishing process, the processed sphere is separated from the sphere clamping and positioning table, and the motion trajectories formed by the three groups of servo grinding head assemblies are evenly distributed on the surface of the processed sphere and can completely cover the surface of the processed sphere, thereby grinding and polishing the processed sphere.

[0011] It is further defined that the output shafts of the three groups of servo grinding head assemblies rotate at variable speeds according to a sinusoidal law, thereby forming a synthetic vector motion control law of the output shafts;

[0012] Among them, the synthetic vector motion control law of the output shaft for:

[0013]

[0014] Wherein, U is the velocity amplitude of the output shaft of the servo grinding head assembly, unit: mm / s; j is an imaginary unit, and the square of j is equal to -1; is the angular velocity of the output shaft of the servo grinding head assembly, unit: rad / s; t is time, unit: s.

[0015] It is further defined that the three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device also includes a base plate and a control module;

[0016] The ball clamping and positioning platform includes a ball positioning seat, a first driving member and a first driving member support, the first driving member support is fixedly connected to the base plate, the first driving member is connected to the first driving member support, the ball positioning seat is connected to the power output end of the first driving member, and the three groups of servo grinding head assemblies are distributed in a ring array on the outer periphery of the ball positioning seat;

[0017] The control module is electrically connected to the first driving member, and is used to control the first driving member to adjust the position of the processed sphere to be on the same horizontal plane as the output shafts of the three servo grinding head assemblies.

[0018] It is further defined that the ball clamping and positioning platform further includes a shield, the shield is fixedly connected to the first driving member support, and the shield covers the outer side of the ball positioning seat;

[0019] The shield is provided with an avoidance groove corresponding to the position of the output shaft of the servo grinding head assembly.

[0020] It is further defined that the servo grinding head assembly includes a cylindrical grinding tool, a fork coupling, a second driving member, a second driving member mounting seat, a first slide, an elastic connecting member, a pressure sensor, a sensor bracket and a second slide, the second slide is fixedly connected to the base plate; the sliding table of the second slide is connected to both the first slide and the sensor bracket; the sliding table of the first slide is connected to the second driving member mounting seat; the second driving member is fixedly connected to the second driving member mounting seat, and the second driving member is located above the second driving member mounting seat; the power output end of the second driving member is connected to the cylindrical grinding tool through the fork coupling; the pressure sensor is connected to the sensor bracket; the elastic connecting member is used to connect the pressure sensor to the second driving member mounting seat;

[0021] The pressure sensor is used to detect the pressure applied by the output shaft of the servo grinding head assembly to the surface of the sphere being processed;

[0022] The pressure sensor and the second driving member are both electrically connected to the control module. The control module is used to adjust the corresponding second driving member according to the pressure detected by the pressure sensor, and adjust the pressure applied by the output shaft of the servo grinding head assembly on the surface of the processed sphere through the second driving member, thereby ensuring that the pressure applied by the output shafts of the three servo grinding head assemblies on the surface of the processed sphere is equal.

[0023] It is further defined that the three-axis three-phase speed-changing ultra-precision micro-ball grinding and polishing device also includes a feeding device, which includes a mounting frame, a guide groove, an electromagnetic push rod, a single ball baffle and a ball positioning tray, the mounting frame is fixedly connected to the base plate; the fixed end and the guide groove of the electromagnetic push rod are fixedly connected to the mounting frame; the guide groove is used to linearly arrange multiple processed balls; the single ball baffle is located at the outlet end of the guide groove; the single ball baffle is connected to the power output end of the electromagnetic push rod, and the electromagnetic push rod controls the single ball baffle to approach or move away from the guide groove, thereby blocking or releasing the processed ball; the ball positioning tray is located below the outlet end of the guide groove, and is used to hold the released processed ball;

[0024] The electromagnetic push rod is electrically connected to a control module, and the control module is used to control the movement of the electromagnetic push rod.

[0025] It is further defined that the feeding device also includes a vibration motor and a ball clamping funnel, and the vibration motor and the ball clamping funnel are fixedly connected to the mounting frame; the outlet end of the ball clamping funnel is connected to the inlet end of the guide groove, and the vibration force generated by the vibration motor causes the disorderly arranged processed balls in the ball clamping funnel to fall into the guide groove, and the processed balls are linearly arranged in the guide groove.

[0026] It is further defined that the three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device also includes a ball clamping device, which includes a bracket, a flexible clamping claw, a swing cylinder, a swing cylinder frame, a third driving member and a fourth driving member, the bracket is fixedly connected to the base plate; the fixed end of the fourth driving member is fixedly connected to the bracket; the fixed end of the third driving member is fixedly connected to the power output end of the fourth driving member; the swing cylinder is fixedly connected to the power output end of the third driving member through the swing cylinder frame;

[0027] There are at least two flexible clamping claws, and at least two flexible clamping claws are fixedly connected to the lower end surface of the swing cylinder; the flexible clamping claw is driven to move in the horizontal direction by the fourth driving member, and the flexible clamping claw is driven to move in the vertical direction by the third driving member to adjust the position of the flexible clamping claw; the flexible clamping claw is driven to rotate by the swing cylinder to switch between different flexible clamping claws;

[0028] The swing cylinder, the third driving member and the fourth driving member are all electrically connected to the control module, and the actions of the swing cylinder, the third driving member and the fourth driving member are controlled by the control module.

[0029] It is further defined that the ball clamping device also includes a mounting plate, and the fourth driving member is fixedly connected to the bracket via the mounting plate.

[0030] The present invention provides a three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing method based on the above-mentioned three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device, comprising the following steps:

[0031] S1: Place the processed sphere on the sphere clamping and positioning table;

[0032] S2: adjusting the output shaft positions of the three servo grinding head assemblies so that the output shafts of the three servo grinding head assemblies intersect with the center of the sphere being processed and approach the sphere being processed;

[0033] Before grinding and polishing, adjust the output shafts of the three servo grinding head assemblies to apply the same pressure to the surface of the sphere being processed and clamp the sphere being processed. The sphere clamping and positioning platform is retracted and the sphere being processed is separated from the sphere clamping and positioning platform.

[0034] During the grinding and polishing process, the output shafts of the three groups of servo grinding head assemblies rotate at variable speeds according to a sinusoidal law, so that the motion trajectories formed by the three groups of servo grinding head assemblies are evenly distributed on the surface of the processed sphere and can completely cover the surface of the processed sphere. The processed sphere rotates continuously in the horizontal plane, thereby grinding and polishing the processed sphere.

[0035] It is further defined that in step S2, the output shafts of the three groups of servo grinding head assemblies rotate at variable speeds according to a sinusoidal law, thereby forming a synthetic vector motion control law of the output shafts;

[0036] Among them, the synthetic vector motion control law of the output shaft for:

[0037]

[0038] Wherein, U is the velocity amplitude of the output shaft of the servo grinding head assembly, unit: mm / s; j is an imaginary unit, and the square of j is equal to -1; is the angular velocity of the output shaft of the servo grinding head assembly, unit: rad / s; t is time, unit: s.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The three-axis, three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention adjusts the three groups of servo grinding head assemblies so that the output axes (axis one, axis two, and axis three) of the three groups of servo grinding head assemblies intersect at the center of the processed sphere, thereby improving the alignment accuracy of the three groups of servo grinding head assemblies relative to the center of the ultra-precision micro-ball. At the same time, the output axes of the three groups of servo grinding head assemblies are controlled to rotate at variable speeds according to a sinusoidal law, thereby ensuring that the motion trajectories formed by the three groups of servo grinding head assemblies are evenly distributed on the surface of the processed sphere and can completely cover the surface of the processed sphere, thereby preventing the ultra-precision micro-balls from slipping during the processing process and ensuring the stability of the ultra-precision micro-ball processing process.

[0041] 2. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention is suitable for processing single pieces, small batches and non-standard ultra-precision micro-balls with a diameter of less than 3 mm.

[0042] 3. The three-axis three-phase speed-changing ultra-precision micro-ball grinding and polishing device of the present invention not only includes a sphere clamping and positioning platform and three groups of servo grinding head assemblies, but also includes a base plate, a control module, a feeding device and a ball clamping device. The base plate is used to fix the sphere clamping and positioning platform, the three groups of servo grinding head assemblies, the feeding device and the ball clamping device, and the processed spheres are linearly arranged and released by the feeding device. The processed spheres released in the feeding device are moved to the sphere clamping and positioning platform by the ball clamping device, and the intersection of the processed spheres and the output shafts of the three groups of servo grinding head assemblies are positioned and aligned by the sphere clamping and positioning platform and the three groups of servo grinding head assemblies. The driving devices corresponding to the sphere clamping and positioning platform, the three groups of servo grinding head assemblies, the feeding device and the ball clamping device are controlled by the control module, thereby realizing the automatic operation of the entire device, reducing processing costs and improving processing efficiency.

[0043] 4. The roundness of the ultra-precision microspheres processed by the three-axis three-phase variable speed ultra-precision microsphere grinding and polishing device of the present invention can reach 0.08μm, and the surface roughness can be reduced to 0.005μm, achieving G3-level processing accuracy for the entire ball, and the processing accuracy meets the requirements of "GB / T308-2002 Rolling Bearing Steel Balls". BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention;

[0045] Figure 2 Schematic diagram of the sphere clamping and positioning platform;

[0046] Figure 3 is a schematic diagram of the servo grinding head assembly;

[0047] Figure 4 is a schematic diagram of a feeding device;

[0048] Figure 5 is a schematic diagram of the ball clamping device;

[0049] Figure 6 This is a schematic diagram of the principle of the three-axis, three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention. Axis 1, 2, and 3 in the figure are the output axes of the three servo grinding head assemblies, and F1, F2, and F3 are the forces on axis 1, axis 2, and axis 3, respectively. All three forces point toward the center of the ball.

[0050] Figure 7 It is the speed sequence diagram of three axes and three phases;

[0051] Figure 8It is a schematic diagram of sinusoidal velocity vector analysis of three axes and three phases;

[0052] Description of reference numerals:

[0053] 1-processed sphere;

[0054] 2- bottom plate;

[0055] 3-ball clamping and positioning platform, 3.1-ball positioning seat, 3.2-first driving member, 3.3-protective cover, 3.4-first driving member support;

[0056] 4-Servo grinding head assembly, 4.1-Cylindrical grinding tool, 4.2-Fork coupling, 4.3-Second driving member, 4.4-Second driving member mounting seat, 4.5-First slide, 4.6-Elastic connecting member, 4.7-Pressure sensor, 4.8-Sensor bracket, 4.9-Second slide;

[0057] 5-feeding device, 5.1-mounting frame, 5.2-vibration motor, 5.3-ball clamping funnel, 5.4-guide groove, 5.5-electromagnetic push rod, 5.6-single ball baffle, 5.7-ball positioning tray;

[0058] 6-ball clamping device, 6.1-gantry bracket, 6.2-flexible clamping claw, 6.3-swing cylinder, 6.4-swing cylinder frame, 6.5-third drive member, 6.6-fourth drive member, 6.7-mounting plate. DETAILED DESCRIPTION

[0059] The technical solution of the present invention will be further explained below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the embodiments described below.

[0060] See also Figure 1 The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention includes a base plate 2, a sphere clamping and positioning platform 3, a servo grinding head assembly 4, a feeding device 5, a ball clamping device 6 and a control module. The servo grinding head assembly 4 has three groups; the base plate 2 is used to fix the sphere clamping and positioning platform 3, the servo grinding head assembly 4, the feeding device 5 and the ball clamping device 6, and the processed sphere 1 is linearly arranged and released by the feeding device 5, and the processed sphere 1 released in the feeding device 5 is moved to the sphere clamping and positioning platform 3 by the ball clamping device 6, and the intersection of the processed sphere 1 and the output shaft of the three groups of servo grinding head assemblies 4 is positioned and aligned by the sphere clamping and positioning platform 3 and the three groups of servo grinding head assemblies 4, and the driving devices corresponding to the sphere clamping and positioning platform 3, the three groups of servo grinding head assemblies 4, the feeding device 5 and the ball clamping device 6 are controlled by the control module, thereby realizing the automatic operation of the entire device, reducing processing costs and improving processing efficiency.

[0061] See also Figure 2In the present invention, the ball clamping and positioning platform 3 includes a ball positioning seat 3.1, a first driving member 3.2, a shield 3.3 and a first driving member support 3.4. The first driving member support 3.4 is fixedly connected to the base plate 2, the first driving member 3.2 is connected to the first driving member support 3.4, the ball positioning seat 3.1 is connected to the power output end of the first driving member 3.2, and the first driving member 3.2 adjusts the position of the processed ball 1 placed in the ball positioning seat 3.1 through the ball positioning seat 3.1 so that it is at the same level as the output shaft of the three sets of servo grinding head assemblies 4 surface, ensuring that the flatness of the three groups of servo grinding head assemblies 4 and the processed sphere 1 is not greater than 0.01 mm; the three groups of servo grinding head assemblies 4 are distributed in a ring array on the periphery of the sphere positioning seat 3.1; the shield 3.3 is fixedly connected to the first drive member support 3.4, and the shield 3.3 covers the outside of the sphere positioning seat 3.1 to protect the sphere positioning seat 3.1 and the processed sphere 1; an avoidance groove corresponding to the output shaft position of the servo grinding head assembly 4 is provided on the shield 3.3, for the corresponding output shaft of the servo grinding head assembly 4 to pass through and approach the processed sphere 1.

[0062] The control module is electrically connected to the first driving member 3.2. The control module is used to control the first driving member 3.2 to adjust the position of the processed sphere 1 to be on the same horizontal plane as the output shaft of the three sets of servo grinding head assemblies 4. Specifically, a position sensor is provided on the sphere positioning seat 3.1. The position sensor is electrically connected to the control module. The position data of the sphere positioning seat 3.1 is measured by the position sensor and the position data is transmitted to the control module. The control module determines whether the sphere positioning seat 3.1 has reached the set position based on the position data, and controls the action of the first driving member 3.2 according to the judgment result.

[0063] In the present invention, preferably, the first driving member 3.2 is a cylinder for adjusting the position of the processed sphere 1 in the vertical direction. In addition, it can also be a hydraulic cylinder or other conventional driving members.

[0064] See also Figure 3The servo grinding head assembly 4 includes a cylindrical grinding tool 4.1, a fork coupling 4.2, a second driving member 4.3, a second driving member mounting seat 4.4, a first slide 4.5, an elastic connecting member 4.6, a pressure sensor 4.7, a sensor bracket 4.8 and a second slide 4.9. The second slide 4.9 is fixedly connected to the base plate 2; the sliding platform of the second slide 4.9 is connected to the first slide 4.5 and the sensor bracket 4.8, and the second slide 4.9 is used to synchronously adjust the positions of the first slide 4.5 and the sensor bracket 4.8; the sliding platform of the first slide 4.5 is connected to the second driving member mounting seat 4.4, and the first slide 4.5 is used to adjust the position of the second driving member mounting seat 4.4. By adjusting the second driving member mounting seat The position of the mounting seat 4.4 is adjusted to adjust the position of the output shaft of the servo grinding head assembly 4; the second driving member 4.3 is fixedly connected to the second driving member mounting seat 4.4, and the second driving member 4.3 is located above the second driving member mounting seat 4.4; the power output end of the second driving member 4.3 is connected to the cylindrical grinding tool 4.1 through the fork coupling 4.2, and the second driving member 4.3 transmits power to the cylindrical grinding tool 4.1 through the fork coupling 4.2; the pressure sensor 4.7 is connected to the sensor bracket 4.8; the elastic connecting member 4.6 is used to connect the pressure sensor 4.7 to the second driving member mounting seat 4.4, specifically, the second driving member mounting seat 4.4 is in contact with the pressure sensor 4.7 through the elastic connecting member 4.6.

[0065] In the present invention, preferably, the first slide 4.5 is a frictionless slide, and the second slide 4.9 is a screw slide. The screw slide feed can ensure the repeatability of the output shafts of the three groups of servo grinding head assemblies 4, thereby achieving the pressure balance of the output shafts of the three groups of servo grinding head assemblies 4. In addition, the first slide 4.5 and the second slide 4.9 can also be other conventional slide structures.

[0066] Among them, the pressure sensor 4.7 is used to detect the pressure applied by the output shaft of the servo grinding head assembly 4 on the surface of the processed sphere 1, and the pressure applied by the cylindrical grinding tool 4.1 on the processed sphere 1 is balanced with the force on the output shaft of the three groups of servo grinding head assemblies 4.

[0067] In the present invention, preferably, the elastic connecting member 4.6 is a compression spring. In addition, it can also be other structures that can achieve elastic limiting connection.

[0068] The pressure sensor 4.7 and the second driving member 4.3 are both electrically connected to the control module, and the control module is used to adjust the corresponding second driving member 4.3 according to the pressure detected by the pressure sensor 4.7. Specifically, the control module compares and judges the pressure detected by the pressure sensor 4.7 with the set standard pressure, and controls the second driving member 4.3 according to the comparison and judgment result, so as to adjust the pressure applied by the output shaft of the servo grinding head assembly 4 to the surface of the processed sphere 1 through the second driving member 4.3, thereby ensuring that the pressure applied by the output shafts of the three servo grinding head assemblies 4 to the surface of the processed sphere 1 is equal, so that the processed sphere 1 can be clamped.

[0069] In the present invention, preferably, the second driving member 4.3 is a servo motor. In addition, it can also be other driving devices well known to those skilled in the art.

[0070] In the present invention, there is a sphere clamping and positioning platform 3 and three groups of servo grinding head assemblies 4 distributed in a circular array on the periphery of the sphere clamping and positioning platform 3; the sphere clamping and positioning platform 3 is used to place the processed sphere 1, and adjust the position of the processed sphere 1 to be on the same horizontal plane as the output axes of the three groups of servo grinding head assemblies 4; the phase difference between the three groups of servo grinding head assemblies 4 is 120°, and the output axes of the three groups of servo grinding head assemblies 4 intersect at the center of the processed sphere 1, and rotate at variable speeds according to a sinusoidal law; during the grinding and polishing process, the processed sphere 1 is separated from the sphere clamping and positioning platform 3, and the motion trajectory formed by the three groups of servo grinding head assemblies 4 is evenly distributed on the surface of the processed sphere 1 and can completely cover the surface of the processed sphere 1, thereby grinding and polishing the processed sphere 1.

[0071] The output shafts of the three servo grinding head assemblies 4 rotate at variable speeds according to a sinusoidal law, thereby forming a synthetic vector motion control law for the output shafts;

[0072] Among them, the synthetic vector motion control law of the output shaft for:

[0073]

[0074] Wherein, U is the velocity amplitude of the output shaft of the servo grinding head assembly 4, unit: mm / s; j is an imaginary unit, and the square of j is equal to -1; is the angular velocity of the output shaft of the servo grinding head assembly 4, unit: rad / s; t is time, unit: s.

[0075] See also Figure 4The feeding device 5 includes a mounting frame 5.1, a vibration motor 5.2, a ball clamping funnel 5.3, a guide groove 5.4, an electromagnetic push rod 5.5, a single ball baffle 5.6 and a ball positioning tray 5.7. The mounting frame 5.1, the vibration motor 5.2 and the ball clamping funnel 5.3 are all fixedly connected to the bottom plate 2; the outlet end of the ball clamping funnel 5.3 is connected to the inlet end of the guide groove 5.4, and the vibration force generated by the vibration motor 5.2 causes the disorderly arranged balls 1 to fall into the guide groove 5.4, and causes the balls 1 to be processed to be linearly arranged in the guide groove 5.4. The fixed end of the electromagnetic push rod 5.5 and the guide groove 5.4 are fixedly connected to the mounting frame 5.1; the guide groove 5.4 is used to linearly arrange multiple processed spheres 1; the single-ball baffle 5.6 is located at the outlet end of the guide groove 5.4; the single-ball baffle 5.6 is connected to the power output end of the electromagnetic push rod 5.5, and the electromagnetic push rod 5.5 controls the single-ball baffle 5.6 to approach or move away from the guide groove 5.4, thereby blocking or releasing the processed sphere 1; the sphere positioning tray 5.7 is located below the outlet end of the guide groove 5.4, and is used to hold the released processed sphere 1.

[0076] Specifically, in Figure 4 In the embodiment, there are two mounting brackets 5.1, both fixedly connected to the base plate 2. One mounting bracket 5.1 is located at the inlet of the guide groove 5.4 and is fixedly connected to the vibration motor 5.2, the ball-holding funnel 5.3, and the inlet of the guide groove 5.4. The other mounting bracket 5.1 is located at the outlet of the guide groove 5.4 and is fixedly connected to the electromagnetic push rod 5.5 and the outlet of the guide groove 5.4. A support column is provided in the area where the ball positioning tray 5.7 is located. The bottom end of the support column is fixedly connected to the base plate 2, and the top end of the support column is fixedly connected to the ball positioning tray 5.7, thereby supporting and fixing the ball positioning tray 5.7.

[0077] The electromagnetic push rod 5.5 is electrically connected to the control module, which is used to control the movement of the electromagnetic push rod 5.5. Specifically, the control module sends a control instruction to the electromagnetic push rod 5.5 to extend or retract according to the user's blanking requirements, thereby controlling the movement of the electromagnetic push rod 5.5.

[0078] See also Figure 5The ball clamping device 6 includes a bracket, a flexible clamping claw 6.2, a swing cylinder 6.3, a swing cylinder frame 6.4, a third driving member 6.5, a fourth driving member 6.6 and a mounting plate 6.7. The bracket is fixedly connected to the base plate 2; the fixed end of the fourth driving member 6.6 is fixedly connected to the bracket. Specifically, the fourth driving member 6.6 is fixedly connected to the bracket through the mounting plate 6.7; the fixed end of the third driving member 6.5 is fixedly connected to the power output end of the fourth driving member 6.6; the swing cylinder 6.3 is fixedly connected to the power output end of the third driving member 6.5 through the swing cylinder frame 6.4. There are at least two flexible clamps 6.2, and at least two flexible clamps 6.2 are fixedly connected to the lower end surface of the swing cylinder 6.3; the flexible clamps 6.2 are driven to move in the horizontal direction by the fourth driving member 6.6, and are driven to move in the vertical direction by the third driving member 6.5 to adjust the position of the flexible clamps 6.2; the flexible clamps 6.2 are driven to rotate by the swing cylinder 6.3 to switch different flexible clamps 6.2; preferably, the number of flexible clamps 6.2 is two, so that one of the flexible clamps 6.2 can clamp the processed sphere 1 while the other flexible clamp 6.2 can be used to clamp the processed ultra-precision microsphere.

[0079] In the present invention, the swing cylinder 6.3, the third drive member 6.5 and the fourth drive member 6.6 are all electrically connected to the control module, and the control module controls the actions of the swing cylinder 6.3, the third drive member 6.5 and the fourth drive member 6.6. Specifically, a position sensor is provided on the swing cylinder 6.3, and the position sensor measures the position data of the swing cylinder 6.3 and transmits the position data to the control module. The control module compares and judges the position data with the preset position data of the ball positioning tray 5.7 or the position data of the ball positioning seat 3.1, and controls the third drive member 6.5 and the fourth drive member 6.6 based on the comparison and judgment results.

[0080] Preferably, the above-mentioned bracket is a portal bracket 6.1.

[0081] In the present invention, preferably, the third driving member 6.5 is a dual-axis cylinder and the fourth driving member 6.6 is a rodless cylinder. In addition, the third driving member 6.5 and the third driving member 6.5 can also be replaced by other driving members familiar to those skilled in the art, such as: electric push rods, hydraulic driving members, etc.

[0082] The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing method formed based on the above-mentioned three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device includes the following steps:

[0083] A plurality of balls 1 to be processed are placed in the ball-holding hopper 5.3 of the feeding device 5. The vibration motor 5.2 is started, causing the plurality of balls 1 to be processed, which are arranged in disorder in the ball-holding hopper 5.3, to fall into the guide groove 5.4 and to be arranged in a straight line (ordered linear arrangement) in the guide groove 5.4. The electromagnetic push rod 5.5 is started to release the frontmost ball 1 to be processed in the guide groove 5.4 into the ball positioning tray 5.7. At the same time, the electromagnetic push rod 5.5 is immediately withdrawn to block the other balls 1 to be processed that have not been released.

[0084] The fourth driving member 6.6 on the ball clamping device 6 is started, driving the flexible clamping claw 6.2 to move in the horizontal direction, thereby moving the flexible clamping claw 6.2 to just above the ball positioning tray 5.7, and the fourth driving member 6.6 stops; the third driving member 6.5 is started, driving the flexible clamping claw 6.2 to move vertically downward, grabbing the processed ball 1 in the ball positioning tray 5.7, and after grabbing, the third driving member 6.5 drives the flexible clamping claw 6.2 to move vertically upward, and after moving to the set height, the third driving member 6.5 stops; the fourth driving member 6.6 is started, driving the flexible clamping claw 6.2 to move in the opposite direction to the horizontal, and moving the flexible clamping claw 6.2 to just above the ball positioning seat 3.1, and the fourth driving member Component 6.6 stops; the oscillating cylinder 6.3 switches the idle flexible clamping claw 6.2 to face the sphere positioning seat 3.1, and the third driving component 6.5 is started, driving the flexible clamping claw 6.2 to move vertically downward to grab the ultra-precision micro-ball that has been processed on the sphere positioning seat 3.1, and the flexible clamping claw 6.2 is switched by the oscillating cylinder 6.3 to face the flexible clamping claw 6.2 that grabs the processed sphere 1 to face the sphere positioning seat 3.1, so that the processed sphere 1 is placed on the sphere positioning seat 3.1; continue to adjust the position of the ultra-precision micro-ball that has been processed by the third driving component 6.5 and the fourth driving component 6.6 according to the above process, and place the ultra-precision micro-ball that has been processed at the specified position;

[0085] The vertical position of the processed sphere 1 is adjusted by the first driving member 3.2 so that the position of the processed sphere 1 is aligned with the output shafts of the three servo grinding head assemblies 4;

[0086] Adjust the output shaft positions of the three servo grinding head assemblies 4 so that the output shafts of the three servo grinding head assemblies 4 intersect with the center of the sphere 1 to be processed and approach the sphere 1 to be processed;

[0087] Before grinding and polishing, adjust the output shafts of the three servo grinding head assemblies 4 to apply the same pressure to the surface of the processed sphere 1 and clamp the processed sphere 1. The sphere clamping and positioning platform 3 is retracted and the processed sphere 1 is separated from the sphere clamping and positioning platform 3.

[0088] During the grinding and polishing process, the output shafts of the three groups of servo grinding head assemblies 4 rotate at variable speeds according to a sinusoidal law, so that the motion trajectories formed by the three groups of servo grinding head assemblies 4 are evenly distributed on the surface of the processed sphere 1 and can completely cover the surface of the processed sphere 1. The processed sphere 1 rotates continuously in the horizontal plane, thereby grinding and polishing the processed sphere 1.

[0089] In the above steps, the output shafts of the three servo grinding head assemblies 4 rotate at variable speeds according to a sinusoidal law, thereby forming a synthetic vector motion control law of the output shafts;

[0090] Among them, the synthetic vector motion control law of the output shaft for:

[0091]

[0092] Wherein, U is the velocity amplitude of the output shaft of the servo grinding head assembly 4, unit: mm / s; j is an imaginary unit, and the square of j is equal to -1; is the angular velocity of the output shaft of the servo grinding head assembly 4, unit: rad / s; t is time, unit: s.

[0093] In the present invention, see Figure 6 The output shafts of the three servo grinding head assemblies 4 have a phase difference of 120°. Structurally, the output shafts of the three servo grinding head assemblies 4 form an angle of 120° and intersect at the center of the sphere 1 being processed; see Figure 7 The output shafts of the three servo grinding head assemblies 4 all rotate at a sinusoidal speed, so that the spin axis of the processed sphere 1 rotates continuously at an angular velocity θ in the horizontal plane. The motion of the sphere is completely consistent with the grinding mechanism. The angular velocity of the sphere is 1.5U, where U is the velocity amplitude of the output shaft of the servo grinding head assembly 4. Figure 8 The spin axis of the processed sphere 1 rotates continuously 360° per cycle at an angular velocity θ according to a three-phase timing sequence, and this cycle continues until the grinding is completed.

[0094] In the present invention, the synthetic vector motion control law of the output shaft The derivation process is:

[0095] The velocity sinusoidal curve expression of each axis is:

[0096]

[0097] In the formula, is the velocity sinusoidal curve expression of axis 1; is the velocity sinusoidal curve expression of axis 2; is the velocity sinusoidal curve expression of axis 3; U is the velocity amplitude of the output shaft of the servo grinding head assembly 4, unit: mm / s; is the phase angle of axis 1, unit: rad; is the phase angle of axis 2, unit: rad; is the phase angle of axis 3, unit: rad, in the initial given value, 、 、 ; is the angular velocity of the output shaft of the servo grinding head assembly 4, unit: rad / s; t is time, unit: s.

[0098] right 、 and Perform vector synthesis and get:

[0099]

[0100] Converted to plural form:

[0101]

[0102] According to Euler's formula Converts to:

[0103]

[0104] From this we can see that the three-axis velocity composite vector is an angular velocity ( ) and the vector rotating around the center of the processed sphere 1, the velocity amplitude of the processed sphere 1 is the original times, the spin axis of the processed sphere 1 rotates 360° per cycle.

[0105] The output shafts of the three servo grinding head assemblies 4 rotate at variable speeds according to the sinusoidal law. Figure 7 The composite speed of the output shafts of the three servo grinding head assemblies 4 is obtained by adding the velocity vectors according to the "parallelogram rule" or "polygon rule", see Figure 8 ,The schematic diagram of three-axis three-phase sinusoidal velocity vector analysis,shows the synthetic velocity every 30° in a cycle from 0° to 360°,which is completely consistent with the results of the complex number analysis method.

[0106] The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device of the present invention has been verified to have a motion trajectory formed by the three groups of servo grinding head assemblies 4 that completely covers the surface of the sphere and is evenly distributed. The roundness of the ultra-precision micro-spheres processed can reach 0.08μm, and the surface roughness can be reduced to 0.005μm, achieving the G3 level processing accuracy of the ultra-precision micro-spheres. The processing accuracy meets the requirements of "GB / T308-2002 Rolling Bearing Steel Balls" and has good processing quality.

[0107] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. Three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device, characterized in that: It comprises a sphere mounting and positioning platform (3) and three groups of servo grinding head assemblies (4) distributed in a ring array on the periphery of the sphere mounting and positioning platform (3); The sphere clamping and positioning platform (3) is used to place the sphere to be processed (1) and adjust the position of the sphere to be processed (1) to be on the same horizontal plane as the output shafts of the three sets of servo grinding head assemblies (4); The phase difference between the three groups of servo grinding head assemblies (4) is 120 degrees, and the output shafts of the three groups of servo grinding head assemblies (4) intersect at the center of the processed sphere (1) and rotate at variable speeds according to a sinusoidal law; during the grinding and polishing process, the processed sphere (1) is separated from the sphere clamping and positioning table (3), and the motion trajectories formed by the three groups of servo grinding head assemblies (4) are evenly distributed on the surface of the processed sphere (1) and can completely cover the surface of the processed sphere (1), thereby grinding and polishing the processed sphere (1); The output shafts of the three groups of servo grinding head assemblies (4) rotate at variable speeds according to a sinusoidal law, thereby forming a synthetic vector motion control law of the output shafts; Among them, the synthetic vector motion control law of the output shaft for: Wherein, U is the velocity amplitude of the output shaft of the servo grinding head assembly (4), unit: mm / s; j is an imaginary unit, and the square of j is equal to -1; is the angular velocity of the output shaft of the servo grinding head assembly (4), unit: rad / s; t is time, unit: s.

2. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 1 is characterized in that: The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device also includes a base plate (2) and a control module; The sphere clamping and positioning platform (3) comprises a sphere positioning seat (3.1), a first driving member (3.2) and a first driving member support (3.4), wherein the first driving member support (3.4) is fixedly connected to the base plate (2), the first driving member (3.2) is connected to the first driving member support (3.4), the sphere positioning seat (3.1) is connected to the power output end of the first driving member (3.2), and the three groups of servo grinding head assemblies (4) are distributed in a ring array on the periphery of the sphere positioning seat (3.1); The control module is electrically connected to the first driving member (3.2), and is used to control the first driving member (3.2) to adjust the position of the processed sphere (1) to be on the same horizontal plane as the output shafts of the three sets of servo grinding head assemblies (4).

3. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 2 is characterized in that: The sphere clamping and positioning platform (3) further comprises a shield (3.3), the shield (3.3) being fixedly connected to the first drive member support (3.4), and the shield (3.3) covering the outside of the sphere positioning seat (3.1); An avoidance groove corresponding to the output shaft position of the servo grinding head assembly (4) is provided on the protective cover (3.3).

4. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 2, characterized in that: The servo grinding head assembly (4) comprises a cylindrical grinding tool (4.1), a fork coupling (4.2), a second driving member (4.3), a second driving member mounting seat (4.4), a first slide (4.5), an elastic connecting member (4.6), a pressure sensor (4.7), a sensor bracket (4.8) and a second slide (4.9), wherein the second slide (4.9) is fixedly connected to the base plate (2); the sliding table of the second slide (4.9) is connected to the first slide (4.5) and the sensor bracket (4.8); the sliding table of the first slide (4.5) is connected to the second slide (4.9) The second drive member (4.3) is connected to the second drive member mounting seat (4.4); the second drive member (4.3) is fixedly connected to the second drive member mounting seat (4.4), and the second drive member (4.3) is located above the second drive member mounting seat (4.4); the power output end of the second drive member (4.3) is connected to the cylindrical grinding tool (4.1) through a shift fork coupling (4.2); the pressure sensor (4.7) is connected to the sensor bracket (4.8); the elastic connecting member (4.6) is used to connect the pressure sensor (4.7) to the second drive member mounting seat (4.4); The pressure sensor (4.7) is used to detect the pressure applied by the output shaft of the servo grinding head assembly (4) on the surface of the processed sphere (1); The pressure sensor (4.7) and the second driving member (4.3) are both electrically connected to the control module. The control module is used to adjust the corresponding second driving member (4.3) according to the pressure detected by the pressure sensor (4.7), and adjust the pressure applied by the output shaft of the servo grinding head assembly (4) on the surface of the processed sphere (1) through the second driving member (4.3), thereby ensuring that the pressures applied by the output shafts of the three servo grinding head assemblies (4) on the surface of the processed sphere (1) are equal.

5. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 2, characterized in that: The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device further comprises a feeding device (5), the feeding device (5) comprising a mounting frame (5.1), a guide groove (5.4), an electromagnetic push rod (5.5), a single ball baffle (5.6) and a ball positioning tray (5.7), the mounting frame (5.1) being fixedly connected to the base plate (2); the fixed end and the guide groove (5.4) of the electromagnetic push rod (5.5) being fixedly connected to the mounting frame (5.1); the guide groove (5.4) being used to feed a plurality of processed The spheres (1) are arranged linearly; the single-ball baffle (5.6) is located at the outlet end of the guide groove (5.4); the single-ball baffle (5.6) is connected to the power output end of the electromagnetic push rod (5.5), and the electromagnetic push rod (5.5) controls the single-ball baffle (5.6) to approach or move away from the guide groove (5.4), thereby blocking or releasing the processed spheres (1); the sphere positioning tray (5.7) is located below the outlet end of the guide groove (5.4) and is used to hold the released processed spheres (1); The electromagnetic push rod (5.5) is electrically connected to a control module, and the control module is used to control the movement of the electromagnetic push rod (5.5).

6. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 5, characterized in that: The feeding device (5) further comprises a vibration motor (5.2) and a ball clamping funnel (5.3), both of which are fixedly connected to the mounting frame (5.1); the outlet end of the ball clamping funnel (5.3) is connected to the inlet end of the guide groove (5.4), and the vibration force generated by the vibration motor (5.2) causes the disorderly arranged balls (1) in the ball clamping funnel (5.3) to fall into the guide groove (5.4), and the balls (1) to be processed are linearly arranged in the guide groove (5.4).

7. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 5, characterized in that: The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device further comprises a ball clamping device (6), the ball clamping device (6) comprising a bracket, a flexible clamping claw (6.2), a swing cylinder (6.3), a swing cylinder frame (6.4), a third driving member (6.5) and a fourth driving member (6.6), the bracket being fixedly connected to the base plate (2); the fixed end of the fourth driving member (6.6) being fixedly connected to the bracket; the fixed end of the third driving member (6.5) being fixedly connected to the power output end of the fourth driving member (6.6); the swing cylinder (6.3) being fixedly connected to the power output end of the third driving member (6.5) via the swing cylinder frame (6.4); There are at least two flexible clamping claws (6.2), and at least two flexible clamping claws (6.2) are fixedly connected to the lower end surface of the swing cylinder (6.3); the flexible clamping claw (6.2) is driven to move in the horizontal direction by the fourth driving member (6.6), and the flexible clamping claw (6.2) is driven to move in the vertical direction by the third driving member (6.5), thereby adjusting the position of the flexible clamping claw (6.2); the flexible clamping claw (6.2) is driven to rotate by the swing cylinder (6.3), thereby switching between different flexible clamping claws (6.2); The swing cylinder (6.3), the third drive member (6.5) and the fourth drive member (6.6) are all electrically connected to a control module, and the actions of the swing cylinder (6.3), the third drive member (6.5) and the fourth drive member (6.6) are controlled by the control module.

8. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 7, characterized in that: The ball clamping device (6) further comprises a mounting plate (6.7), and the fourth driving member (6.6) is fixedly connected to the bracket via the mounting plate (6.7).

9. A three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing method based on the three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing device according to claim 2, characterized in that: The following steps are involved: S1: placing the processed sphere (1) on the sphere clamping and positioning table (3); S2: adjusting the output shaft positions of the three servo grinding head assemblies (4) so ​​that the output shafts of the three servo grinding head assemblies (4) intersect with the center of the processed sphere (1) and approach the processed sphere (1); Before grinding and polishing, the output shafts of the three servo grinding head assemblies (4) are adjusted to apply the same pressure to the surface of the processed sphere (1) and clamp the processed sphere (1), the sphere clamping and positioning platform (3) is retracted, and the processed sphere (1) is separated from the sphere clamping and positioning platform (3); During the grinding and polishing process, the output shafts of the three groups of servo grinding head assemblies (4) rotate at variable speeds according to a sinusoidal law, so that the motion tracks formed by the three groups of servo grinding head assemblies (4) are evenly distributed on the surface of the processed sphere (1) and can completely cover the surface of the processed sphere (1), and the processed sphere (1) rotates continuously in the horizontal plane, thereby grinding and polishing the processed sphere (1).

10. The three-axis three-phase variable speed ultra-precision micro-ball grinding and polishing method according to claim 9, characterized in that: In step S2, the output shafts of the three groups of servo grinding head assemblies (4) rotate at variable speeds according to a sinusoidal law, thereby forming a synthetic vector motion control law of the output shafts; Among them, the synthetic vector motion control law of the output shaft is: Wherein, U is the velocity amplitude of the output shaft of the servo grinding head assembly (4), unit: mm / s; j is an imaginary unit, and the square of j is equal to -1; is the angular velocity of the output shaft of the servo grinding head assembly (4), unit: rad / s; t is time, unit: s.

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