Precise automatic grinding device for outer cylindrical surface of part and using method of precise automatic grinding device

Abstract

The invention belongs to the technical field of precision machining, and relates to a part outer cylindrical surface precision automatic grinding device and a using method thereof. A to-be-ground part is driven to rotate through the part rotation driving mechanism arranged on the marble table; the clamping mechanism clamps the grinding shaft sleeve; a vertical reciprocating motion driving mechanism and a grinding shaft sleeve rotating driving mechanism which are connected to the clamping mechanism respectively drive the grinding shaft sleeve to do reciprocating motion and rotating motion in the vertical direction; and the grinding posture of the device is adjusted through a balance mechanism arranged on the clamping mechanism, and the to-be-ground part is ground through a grinding shaft sleeve. The device can correct the taper error of the outer circle face of a workpiece, is good in universality, high in flexibility, convenient to operate, extremely high in grinding precision, low in maintenance cost and suitable for automatic grinding machining of ultra-precision parts such as a base disc and a high-precision bearing, and can achieve online correction of the error of the precision parts.

Description

Technical Field

[0001] The present invention belongs to the technical field of precision grinding, and particularly relates to a precision automatic grinding device for the outer cylindrical surface of a part and a method for using the same. Background Art

[0002] Grinding is an ultra-precision machining process, mainly used for the ultra-precision machining of surfaces composed of simple geometric elements such as planes, cylindrical surfaces, and spherical surfaces. The so-called grinding refers to a method of adding a grinding agent to a grinding tool and performing micro-machining through the relative movement of the grinding tool and the workpiece. The grinding tool is a rigid hard tool. The abrasive removes a small amount of material from the surface of the workpiece, thereby obtaining a finely machined surface with good dimensional accuracy and smoothness. According to whether there is a grinding fluid during grinding, the grinding process can be divided into dry grinding and wet grinding. Grinding is mainly used for the ultra-precision machining of surfaces composed of simple geometric elements such as planes, cylindrical surfaces, and spherical surfaces. At present, the flatness of plane grinding can generally reach 0.2 - 0.5 μm; the roundness of cylindrical surface grinding can generally reach 0.2 - 0.5 μm, and the cylindricity can generally reach 0.5 - 1 μm. External diameter grinding requires an elastic bushing with an inner diameter slightly larger than the outer diameter of the workpiece and the inner diameter size can be finely adjusted within a certain range to achieve.

[0003] Traditional external diameter grinding tooling mostly uses a ring-shaped bushing with one side wall completely disconnected into a C shape. Only the axial movement of the tapered surface rigid ring is used to reduce the inner diameter size, and it is only used for grinding shaft parts with a diameter smaller than the inner diameter of the grinding bushing, and is not suitable for grinding parts with a diameter slightly larger than the inner diameter of the grinding bushing. In addition, the traditional grinding bushing relies on the extrusion of the tapered surface rigid ring and its own elastic deformation to establish a force balance, with weak rigidity, which is not conducive to high-precision grinding. The elastic grinding bushing results in a low roundness of the outer circle surface of the base disc due to the inner hole of the grinding bushing, and there are many error sources in the grinding bushing, making it difficult to achieve a high grinding accuracy.

[0004] The publicly disclosed invention patent "A high-performance adjustable elastic grinding bushing and its manufacturing and using method

CN118269010A

[0005] Patent for Invention "An Elastic Grinding Bush with Symmetrically Distributed Radial Deformation

CN113245929A

[0006] In order to solve the problems in the prior art that the structure of the precision automatic grinding device for the outer cylindrical surface of parts is complex, the versatility is poor, the movement during the grinding process is unstable, the outer circle surface cannot be ground evenly, the grinding accuracy is low, and the taper error of the outer circle surface of the workpiece cannot be corrected, the present invention provides a precision automatic grinding device for the outer cylindrical surface of parts, which is characterized by including: a marble table, and a part rotation driving mechanism for driving the part to be ground to rotate is arranged on the marble table; a grinding bush for grinding the part to be ground; a clamping mechanism for clamping the grinding bush; a vertical reciprocating motion driving mechanism for driving the grinding bush to make a reciprocating motion in the vertical direction and a grinding bush rotation driving mechanism for driving the grinding bush to rotate are connected to the clamping mechanism; a balancing mechanism for adjusting the grinding posture of the grinding bush is also arranged on the clamping mechanism.

[0007] According to the above-mentioned precision automatic grinding device for the outer cylindrical surface of parts, the balancing mechanism includes: a spring balancer bracket; the spring balancer bracket is arranged on the marble table; a spring balancer is arranged on the spring balancer bracket; the spring balancer is connected with a balancing bracket; one end of the balancing bracket is provided with a counterweight and is connected to the vertical reciprocating motion driving mechanism; the other end of the balancing bracket is connected to the grinding bush rotation driving mechanism; the spring balancer and the counterweight cooperate to adjust the levelness of the balancing bracket.

[0008] According to the above-mentioned precision automatic grinding device for the outer cylindrical surface of parts, the vertical reciprocating motion mechanism includes: an electric push rod; the electric push rod drives the grinding bush to make a reciprocating motion up and down, and the base of the electric push rod is arranged on the optical platform through a threaded connection; the telescopic rod of the electric push rod is connected to one end of the balancing bracket.

[0009] According to the above-mentioned precision automatic grinding device for the outer cylindrical surface of parts, the grinding bush rotation driving mechanism includes: a hollow turntable, the base of the hollow turntable is connected to one end of the balancing bracket, and the rotating part of the hollow turntable is connected with a rotating bracket.

[0010] According to a precision automatic grinding device for the outer cylindrical surface of a part described above, the clamping mechanism includes: 4 grinding chucks; the 4 grinding chucks are divided into 2 groups, arranged in pairs and axially along the grinding bushing to fix the position of the grinding bushing; there are 2 connecting shafts respectively arranged vertically between the upper and lower 2 groups of grinding chucks; the grinding chucks can move vertically along the connecting shafts and be fixed; a rotating bracket is connected between the 2 connecting shafts; the 2 connecting shafts can move horizontally along the rotating bracket and be fixed; one end of the connecting shaft is threadedly connected with a locking nut; the connecting shaft is arranged on the rotating bracket through the locking nut. The grinding chuck positions and clamps the grinding bushing to make a rotational movement driven by the hollow turntable; the grinding chuck is provided with a C-shaped annular through hole for clamping the connecting shaft and an opening of the grinding chuck through hole, and the C-shaped annular through hole communicates with the opening of the grinding chuck through hole. The C-shaped annular through hole is used to clamp the grinding chuck on the connecting shaft. One side of the opening of the grinding chuck through hole is provided with a mounting through hole of the grinding chuck, and the other side of the opening of the grinding chuck through hole is provided with a threaded hole for mounting the grinding chuck. A tightening screw of the grinding chuck is arranged in the threaded hole for mounting the grinding chuck to tighten the C-shaped annular through hole of the grinding chuck; a U-shaped groove of the grinding chuck is arranged on the side wall of the grinding chuck, forming a flexible hinge structure with the C-shaped annular through hole and the opening of the grinding chuck through hole, so as to clamp the connecting shaft; a baffle of the grinding bushing for positioning the grinding bushing in the vertical direction is arranged on the grinding chuck. The grinding chuck is provided with 2 large-angle positioning surfaces in line contact with the side wall line of the grinding bushing respectively. After an elastic pad is pasted on the large-angle positioning surface, a surface of the elastic pad of the grinding chuck is formed. The total thickness of the grinding chuck after pasting the elastic pad is smaller than the width of the baffle of the grinding bushing. The part of the bottom surface of the baffle of the grinding bushing protruding from the side wall of the grinding chuck and the surface of the elastic pad of the grinding chuck form an L-shaped structure. A threaded hole for mounting the baffle of the grinding bushing is arranged on the grinding chuck; a through hole of the baffle of the grinding bushing is arranged on the baffle of the grinding bushing, and the baffle of the grinding bushing is mounted on the grinding chuck through threaded connection; the two grinding chucks at the lower part of the connecting shaft and the baffle of the grinding bushing connected thereto position and support the grinding bushing, and the two grinding chucks at the upper part of the connecting shaft and the baffle of the grinding bushing connected thereto position and clamp the grinding bushing. By adjusting the relative positions of the 4 grinding chucks and the baffles of the grinding bushing connected thereto, grinding bushings with different heights and different diameters can be clamped; a retaining baffle is arranged at one end of the connecting shaft; there is 1 through hole of the retaining baffle on the retaining baffle, and the retaining baffle is threadedly connected to one end of the connecting shaft. The retaining baffle is used to prevent the grinding chuck from detaching from the connecting shaft.

[0011] According to a precision automatic grinding device for the outer cylindrical surface of a part described above, the part rotation driving mechanism includes: a locking part arranged on the upper surface of the workpiece turntable, and the part to be ground is installed through the locking part; the locking part includes a rotating core shaft arranged at the center of the workpiece turntable; a locking nut of the rotating core shaft for locking the part to be ground is arranged in a matching manner on the rotating core shaft.

[0012] According to a precision automatic grinding device for the outer cylindrical surface of a part described above, the connecting shaft is fixed on the rotating bracket by a locking nut; the rotating bracket is arranged on the hollow turntable through a threaded connection; the hollow turntable is arranged on the balance bracket through a threaded connection; the balance bracket is arranged on the electric push rod through a threaded connection; one end of the connecting shaft is provided with an external thread, the other end of the connecting shaft is provided with a connecting shaft threaded hole, and the middle part of the connecting shaft is provided with a shaft shoulder and two mutually parallel guide rail planes; the shaft shoulder is arranged between the shaft section of the connecting shaft for installing the grinding clamp and the shaft section of the guide rail plane, and the annular end face on the side of the shaft shoulder close to the guide rail plane is the axial positioning plane of the connecting shaft; the rotating bracket is provided with a waist-shaped groove of the rotating bracket; the width of the guide rail plane is smaller than the width of the waist-shaped groove of the rotating bracket, and the guide rail plane of the connecting shaft can slide along the inner wall of the waist-shaped groove of the rotating bracket. The connecting shaft threaded hole at the end of the connecting shaft is used for installing an anti-detachment baffle; the outer cylindrical surface of the connecting shaft of the connecting shaft is perpendicular to the axial positioning plane of the connecting shaft; The rotating bracket is composed of a hollow cylinder and symmetric cuboids on both radial sides. A number of circumferentially evenly distributed counterbored holes for connecting the rotating part of the hollow turntable are arranged in the middle hollow cylinder, and the circumferentially evenly distributed counterbored holes are evenly distributed along the circumference of the annular end face of the cylinder; the annular end face of the cylinder of the rotating bracket is the plane for installing the rotating part of the hollow turntable; the rotating bracket is provided with a working surface of the rotating bracket, and the working surface of the rotating bracket is parallel to the plane for installing the rotating part of the hollow turntable; the two inner planes of the waist-shaped groove of the rotating bracket are parallel, and the guide rail plane of the connecting shaft is in clearance fit with the waist-shaped groove of the rotating bracket.

[0013] According to a precision automatic grinding device for the outer cylindrical surface of a part described above, a number of U-shaped grooves of the grinding bushing are arranged on the grinding bushing to form a flexible hinge structure. One grinding bushing opening is arranged on the side wall of the grinding bushing along the axial direction. The inner hole diameter of the grinding bushing is adjusted through the grinding bushing opening. A tightening threaded hole of the grinding bushing is arranged on one end face of the grinding bushing opening, and a tightening screw of the grinding bushing is arranged in the tightening threaded hole of the grinding bushing for reducing the inner diameter of the grinding bushing; a swelling screw of the grinding bushing and a counterbored hole corresponding to the tightening threaded hole of the grinding bushing are arranged on the other end face of the grinding bushing opening. A swelling screw of the grinding bushing is arranged in the swelling threaded hole of the grinding bushing, and the swelling screw of the grinding bushing is used for expanding the inner diameter of the grinding bushing.

[0014] According to a precision automatic grinding device for the outer cylindrical surface of a part described above, the balance bracket is formed by vertically connecting two flat plates. One end of the flat plate in the horizontal direction of the balance bracket is provided with a slot hole of the balance bracket. The counterweight is connected in the slot hole of the balance bracket through a screw and can move and be fixed along the slot hole of the balance bracket; a number of threaded holes for installing the base of the hollow turntable are arranged at the other end of the flat plate in the horizontal direction of the balance bracket; a number of counterbored holes for installing the electric push rod are arranged in the middle of the flat plate in the horizontal direction of the balance bracket, and a round hole for connecting the spring balancer is arranged on the vertical flat plate of the balance bracket.

[0015] According to the usage method of a precision automatic grinding device for the outer cylindrical surface of a part described above, it includes the following steps: Step S1: Adjust the balance bracket to be horizontal Install the workpiece turntable on the marble table, and install the spring balancer bracket on two sides of the marble table; the spring balancer bracket is connected to one end of the spring balancer; threadedly connect and install the electric push rod base onto the optical platform; threadedly connect and install the balance bracket onto the electric push rod; threadedly connect and install a counterweight block at one end of the balance bracket, threadedly connect and install the hollow turntable base at the other end of the balance bracket, and connect the other end of the spring balancer to the balance bracket; the rotating part of the hollow turntable is threadedly connected to the rotating bracket; install the connecting shaft and the rotating bracket through a locking nut; clamp the grinding chuck on the connecting shaft, install the grinding bushing baffle onto the grinding chuck, and the grinding bushing is clamped between the grinding chuck and the grinding bushing baffle; adjust the spring balancer connected to the balance bracket; loosen the screw of the counterweight block and the balance bracket, and move the counterweight block; twist the rotating nut of the spring balancer to adjust the pulling force of the spring balancer; change the torque at both ends of the balance bracket through the spring balancer and the counterweight block to maintain the weight balance at both ends of the balance bracket, so as to adjust the balance bracket to be horizontal; Step S2: Align the rotation center of the rotating mandrel on the workpiece turntable Install a stepped rotating mandrel on the upper turntable of the workpiece turntable. One end of the rotating mandrel is provided with an external thread, and the stepped end face at the other end is provided with four circumferentially evenly distributed counterbore holes; the rotating mandrel is threadedly connected and installed on the workpiece turntable through the counterbore holes; fix the dial indicator base on the marble table, the dial indicator base clamps the lever side probe, the lever side probe contacts the outer cylindrical surface of the part to be ground installed on the rotating mandrel on the workpiece turntable, and by changing the relative position between the rotating mandrel and the workpiece turntable, align the rotation center of the rotating mandrel on the workpiece turntable, and then lock the screws in the four counterbore holes of the rotating mandrel; Step S3: Adjust the parallelism of the rotating bracket Raise the electric push rod, magnetically attract a dial indicator base on the working surface of the rotating bracket, the dial indicator base clamps the lever side probe, the lever side probe contacts the plane of the part to be ground installed on the rotating mandrel on the workpiece turntable, rotate the hollow turntable, observe the reading of the lever side probe measuring the end face runout of the rotating mandrel, and adjust the parallelism between the working plane of the rotating bracket and the plane of the part to be ground installed on the rotating mandrel on the workpiece turntable to within 1 µm by changing the position of the counterweight block in the balance bracket slot hole where the counterweight block is installed on the balance bracket and the pulling force of the spring balancer; Step S4: Install the part to be ground Install the part to be ground on the rotating mandrel installed on the workpiece turntable. The inner hole of the part to be ground, the spiral precision ball bushing and the outer cylindrical surface of the part to be ground installed on the rotating mandrel are in interference fit, and use flat washers, cross washers and locking nuts to install the part to be ground on the rotating mandrel; Step S5: Adjust the radial runout deviation of the outer cylindrical surface of the part to be ground Magnetically attach the dial indicator base to the working surface of the rotating bracket. The lever side probe contacts the outer cylindrical surface of the part to be ground. By rotating the hollow turntable, observe the reading of the lever side probe measuring the radial runout of the outer cylindrical surface of the part to be ground. By changing the relative positions of the hollow turntable and the balance bracket with respect to the outer cylindrical surface of the part to be ground, that is, changing the relative positions of the counterbored holes of the electric push rods installed on the balance bracket and the electric push rods, and adjusting the relative positions of the threaded holes of the hollow turntable base for installing the hollow turntable, control the radial runout deviation of the rotation center of the rotating bracket with respect to the outer cylindrical surface of the part to be ground within 1 µm; Step S6: Install the clamping mechanism Install the grinding bushing baffle on the grinding clamp with screws. The part of the bottom surface of the grinding bushing baffle protruding from the side wall of the grinding clamp forms an L-shaped structure with the surface of the elastic pad. Install the C-shaped annular through holes of the four grinding clamps on the outer cylindrical surfaces of the two connecting shafts in pairs respectively. Tighten the tension screws of the clamping threaded holes of the grinding clamps, and install the anti-disengagement baffle at one end of the connecting shaft; Loosen the lock nut until the guide rail plane of the connecting shaft can slide in the waist-shaped groove of the rotating bracket, and loosen the tension screws of the clamping threaded holes of the grinding clamps so that the C-shaped annular through holes of the grinding clamps can rotate on the outer cylindrical surface of the connecting shaft; Step S7: Position and clamp the grinding bushing Install the inner hole of the grinding bushing on the outer cylindrical surface of the part to be ground. Apply grinding compound on the outer cylindrical surface of the part to be ground. Slide the grinding bushing up and down along the outer cylindrical surface of the part to be ground. Adjust the tightening screw and the expanding threaded screw of the grinding bushing on the grinding bushing to make the inner hole surface of the grinding bushing and the outer cylindrical surface of the part to be ground in clearance fit; Press the two grinding bushing baffles installed at the lower part of the connecting shaft tightly against the end face of the grinding bushing, press the surface of the elastic pad of the grinding clamp tightly against the outer cylindrical surface of the grinding bushing, and tighten the tension screws in the clamping threaded holes of the two grinding clamps at the lower part of the connecting shaft; Press the two grinding bushing baffles installed at the upper part of the connecting shaft tightly against the end face of the grinding bushing, press the surface of the elastic pad of the grinding clamp tightly against the outer cylindrical surface of the grinding bushing, and tighten the tension screws in the clamping threaded holes of the two grinding clamps at the upper part of the connecting shaft; Position and clamp the grinding bushing with the two groups of grinding bushing baffles and grinding clamps at the upper and lower parts of the connecting shaft; Step S8: Fix and connect the connecting shaft and the rotating bracket Manually lock the lock nut so that the axial positioning plane is closely attached to the working plane of the rotating bracket; Step S9: Grind the outer cylindrical surface of the part to be ground Apply abrasive on the outer cylindrical surface of the part to be ground, and rotate the hollow turntable and the workpiece turntable; the hollow turntable drives the grinding bushing to make a rotational motion; the workpiece turntable drives the part to be ground to make a rotational motion; the electric push rod drives the grinding bushing to make a reciprocating motion up and down. The rotational speed of the hollow turntable and the rotational speed of the workpiece turntable are relatively prime, so that the motion trajectories of the outer cylindrical surface of the part to be ground and the inner hole surface of the grinding bushing are inconsistent, and the rotational motion directions of the two are opposite; the electric push rod makes a reciprocating motion up and down; during the grinding process, add abrasive from the end of the U-shaped groove of the grinding bushing. After grinding for a period of time, turn over the grinding bushing and reinstall it, and continue to grind the outer cylindrical surface of the part to be ground until the grinding is completed.

[0016] The beneficial effects of the present invention are as follows: 1. Through the connection structure between the electric push rod and the hollow turntable, the present invention realizes the compound motion of the reciprocating motion up and down and the rotational motion of the grinding bushing. The electric push rod drives the grinding bushing to make a high-frequency reciprocating motion along the axial direction of the workpiece, and the hollow turntable drives the grinding bushing to rotate uniformly around the outer cylindrical surface of the workpiece. The rotational speeds of the two are relatively prime and the directions are opposite, so that the grinding trajectory is distributed in a complex network shape, avoiding the repetitive scratches caused by the traditional single motion. This compound motion significantly improves the uniformity of the distribution of the abrasive on the surface of the workpiece, effectively eliminating the problem of uneven local wear. It is especially suitable for the processing of ultra-precision and high-precision parts such as base disks and high-precision bearings.

[0017] 2. The L-shaped clamping structure composed of the grinding clamp and the grinding bushing baffle of the present invention, combined with the flexible hinge structure, realizes high adaptability to grinding bushings of different sizes. The inner diameter of the C-shaped annular through hole at the rear of the grinding clamp is adjusted by a tension screw, and the clearance fit between the connecting shaft guide plane and the waist-shaped groove of the rotating bracket supports the clamping of grinding bushings of different size specifications. At the same time, an elastic pad is pasted on the 160° V-shaped positioning surface of the grinding clamp, which can not only provide uniform clamping force, but also buffer vibration, avoiding the deformation of the bushing caused by rigid clamping. By adjusting the distance between the upper and lower grinding clamps of the connecting shaft and the screw pre-tightening force, the quick replacement of grinding bushings of different specifications can be completed, significantly shortening the device debugging time. It has good versatility and is suitable for the flexible production requirements of multi-variety and small-batch precision parts.

[0018] 3. The connection structure of the balance bracket, counterweight, and spring balancer of the present invention solves the technical problem of device vibration under compound motion. The balance bracket is formed by vertically connecting two flat plates. The bottom surface of the balance bracket is ground to reach the 0-level knife-edge ruler standard in flatness, ensuring rigid support. The counterweight adjusts the torque by sliding through the slot holes of the balance bracket, and the spring balancer provides adjustable tension. The combination of the two can dynamically compensate for the inertial force generated by the reciprocating motion of the electric push rod. The horizontal deviation of the balance bracket can be controlled within 1 μm, effectively suppressing the low-frequency vibration during the operation of the device. In addition, the parallelism between the working surface of the rotating bracket and the workpiece turntable is monitored and adjusted in real time by the lever side probe, further reducing the axial runout error. This greatly reduces the contact pressure fluctuation between the grinding bushing and the workpiece during the grinding process, significantly improving the consistency of the surface roughness, having good processing stability, and at the same time can correct the taper error of the outer cylindrical surface of the workpiece.

[0019] 4. The grinding bushing of the present invention adopts a combined structure of flexible hinges and expansion screws, breaking through the limitation of the small rigid deformation range of traditional bushings. An opening is axially provided on the side wall of the bushing, which cooperates with the expansion screw and the tension screw to finely adjust the inner hole diameter and compensate for the dimensional error and taper deviation of the outer cylindrical surface of the workpiece in real time. The U-shaped groove structure makes the circumferential stiffness distribution of the bushing uniform, and the grinding pressure is transmitted more smoothly, avoiding local over-grinding. In practical applications, the operator can dynamically adjust the screw pre-tightening force by monitoring the data of the lever probe to achieve on-line correction of the errors of precision parts during grinding and improve the processing accuracy.

[0020] 5. The present invention adopts a modular structure, and the grinding clamp, connecting shaft, and rotating bracket all support quick disassembly and replacement. The grinding bushing baffle is fixed through threaded holes, which is convenient to replace; the guide rail plane of the connecting shaft is treated with hard chromium plating to improve wear resistance. The clearance fit structure between the waist-shaped groove of the rotating bracket and the connecting shaft allows for compensating the positioning accuracy by adjusting the locking nut after slight wear, avoiding overall scrapping; the elastic pad of the grinding clamp can be replaced regularly. The maintenance efficiency and service life are improved, which is especially suitable for industrial scenarios with high-load continuous production. Brief Description of the Drawings

[0021] Figure 1 It is a schematic diagram of the overall structure of a precision automatic grinding device for the outer cylindrical surface of parts of the present invention.

[0022] Figure 2 It is a schematic diagram of the balance bracket structure of the present invention.

[0023] Figure 3 It is a schematic diagram of the rotating bracket structure of the present invention Figure 1 .

[0024] Figure 4 It is a schematic diagram of the rotating bracket structure of the present invention Figure 2 .

[0025] Figure 5Schematic diagram of the grinding bushing structure of the present invention.

[0026] Figure 6 Schematic diagram of the connecting shaft structure of the present invention.

[0027] Figure 7 Schematic diagram of the grinding clamp structure of the present invention Figure 1 。

[0028] Figure 8 Schematic diagram of the grinding clamp structure of the present invention Figure 2 。

[0029] Figure 9 Schematic diagram of the grinding clamp structure of the present invention Figure 3 。

[0030] Figure 10 Schematic diagram of the grinding bushing baffle structure of the present invention.

[0031] Figure 11 Schematic diagram of the anti - detachment baffle structure of the present invention.

[0032] Figure 12 Schematic diagram of the installation of the grinding clamp of the present invention Figure 1 。

[0033] Figure 13 Schematic diagram of the installation of the grinding clamp of the present invention Figure 2 。

[0034] Figure 14 Schematic diagram of the lock nut structure of the present invention.

[0035] Figure 15 Schematic diagram of the installation of the grinding bushing of the present invention.

[0036] Figure 16 Schematic diagram of the working process of adjusting the radial run - out of the rotating mandrel of the present invention.

[0037] Figure 17 Schematic diagram of the working process of adjusting the end - face run - out of the balance bracket of the present invention.

[0038] Figure 18 Schematic diagram of the working process of adjusting the radial run - out of the balance bracket of the present invention.

[0039] Figure 19 Partial installation schematic diagram of a precision automatic grinding device for the outer cylindrical surface of a part of the present invention.

[0040] In the figure: 1: Marble table; 2: Workpiece turntable; 3: Electric push rod; 4: Part to be ground; 4-1: Outer cylindrical surface of the part to be ground; 5: Counterweight; 6: Balancing bracket; 6-1: Threaded hole for installing the hollow turntable base; 6-2: Upper surface of the balancing bracket; 6-3: Bottom surface of the balancing bracket; 6-4: Countersunk hole for installing the electric push rod; 6-5: Slot hole of the balancing bracket; 7: Spring balancer; 8: Spring balancer bracket; 9: Hollow turntable; 10: Rotating bracket; 10-1: Waist-shaped slot of the rotating bracket; 10-2: Plane for installing the rotating part of the hollow turntable; 10-3: Working surface of the rotating bracket; 10-4: Circumferentially evenly distributed countersunk holes of the rotating bracket; 11: Locking nut; 12: Connecting shaft; 12-1: Threaded hole of the connecting shaft; 12-2: Outer cylindrical surface of the connecting shaft; 12-3: Axial positioning plane; 12-4: Guide rail plane; 12-5: External thread of the connecting shaft; 13: Grinding bushing; 13-1: Inner hole surface of the grinding bushing; 13-2: Outer cylindrical surface of the grinding bushing; 13-3: Threaded hole for expanding the grinding bushing; 13-4: Threaded hole for tightening the grinding bushing; 13-5: Opening of the grinding bushing; 13-6: End face of the grinding bushing; 13-7: U-shaped groove of the grinding bushing; 14: Grinding clamp; 14-1: Threaded hole for installing the baffle of the grinding bushing; 14-2: Opening of the through hole of the grinding clamp; 14-3: C-shaped annular through hole; 14-4: Polyurethane surface of the grinding clamp; 14-5: Threaded hole for clamping of the grinding clamp; 14-6: U-shaped groove of the grinding clamp; 14-7: Clamping through hole of the grinding clamp; 15: Baffle of the grinding bushing; 16: Anti-detachment baffle; 17: Rotating mandrel; 17-1: Outer cylindrical surface of the mounting base disk of the rotating mandrel; 17-2: Plane of the mounting base disk of the rotating mandrel; 18: Lever side probe. Detailed implementation manner

[0041] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0042] As Figures 1 to 15 shown: A precision automatic grinding device for the outer cylindrical surface of a part, comprising: a marble table 1, and a part rotation driving mechanism for driving the part 4 to be ground to rotate is arranged on the marble table 1; a grinding bushing 13 for grinding the part to be ground, and the grinding bushing 13 is arranged on a clamping mechanism for clamping the grinding bushing 13; a vertical reciprocating motion driving mechanism for driving the grinding bushing 13 to perform reciprocating motion in the vertical direction and a grinding bushing rotation driving mechanism for driving the grinding bushing 13 to rotate are connected to the clamping mechanism; a balancing mechanism for adjusting the grinding posture of the grinding bushing 13 is further arranged on the clamping mechanism.

[0043] The balance mechanism includes: a spring balancer bracket 8; the spring balancer bracket 8 is arranged on the marble table 1; a spring balancer 7 is arranged on the spring balancer bracket 8; the spring balancer 7 is connected with a balance bracket 6; one end of the balance bracket 6 is provided with a counterweight 5 and is connected with the vertical reciprocating motion driving mechanism; the other end of the balance bracket 6 is connected with the grinding bushing rotation driving mechanism; the spring balancer 7 and the counterweight 5 cooperate to adjust the levelness of the balance bracket 6.

[0044] The vertical reciprocating motion mechanism includes: an electric push rod 3; the electric push rod 3 drives the grinding bushing 13 to make up-and-down reciprocating motion, and the base of the electric push rod 3 is arranged on the optical platform through threaded connection; the telescopic rod of the electric push rod 3 is connected with one end of the balance bracket 6.

[0045] The grinding bushing rotation driving mechanism includes: a hollow turntable 9, the base of the hollow turntable 9 is connected with one end of the balance bracket 6, and the rotating part of the hollow turntable 9 is connected with a rotating bracket 10.

[0046] The clamping mechanism includes: 4 grinding clamps 14; the 4 grinding clamps 14 are divided into 2 groups, arranged in pairs opposite to each other and axially arranged along the grinding bushing 13 to fix the position of the grinding bushing 13; 2 connecting shafts 12 are respectively arranged vertically between the upper and lower 2 groups of grinding clamps 14; the grinding clamps 14 can move vertically along the connecting shafts 12 and be fixed; the 2 connecting shafts 12 are connected with the rotating bracket 10; the 2 connecting shafts 12 can move horizontally along the rotating bracket 10 and be fixed; one end of the connecting shaft 12 is threadedly connected with a locking nut 11; the connecting shaft 12 is arranged on the rotating bracket 10 through the locking nut 11; The grinding clamp 14 positions and clamps the grinding bushing 13, and under the drive of the hollow turntable 9, it makes a rotational movement; on the grinding clamp 14, there is a C-shaped annular through-hole 14-3 for clamping the connecting shaft 12 and a grinding clamp through-hole opening 14-2. The C-shaped annular through-hole 14-3 communicates with the grinding clamp through-hole opening 14-2. The C-shaped annular through-hole 14-3 is used to clamp the grinding clamp 14 on the connecting shaft 12. On one side of the grinding clamp through-hole opening 14-2, there is a grinding clamp clamping through-hole 14-7, and on the other side of the grinding clamp through-hole opening 14-2, there is a grinding clamp clamping threaded hole 14-5. Inside the grinding clamp clamping threaded hole 14-5, there is a grinding clamp tensioning screw for tensioning the C-shaped annular through-hole 14-3 of the grinding clamp 14; on the side wall of the grinding clamp 14, there is a grinding clamp U-shaped groove 14-6, which forms a flexible hinge structure with the C-shaped annular through-hole 14-3 and the grinding clamp through-hole opening 14-2, so as to clamp the connecting shaft 12; on the grinding clamp 14, there is a grinding bushing baffle 15 for positioning the grinding bushing 13 in the vertical direction. The grinding clamp 14 is provided with 2 large-angle positioning surfaces that are in line contact with the side wall of the grinding bushing 13. Elastic pads are pasted on the large-angle positioning surfaces. The total thickness of the grinding clamp 14 after pasting the elastic pads is 2 mm smaller than the width of the grinding bushing baffle 15. The part of the bottom surface of the grinding bushing baffle 15 that protrudes from the side wall of the grinding clamp 14 forms an L-shaped structure with the surface of the elastic pad. On the grinding clamp 14, there are threaded holes for installing the grinding bushing baffle 15; on the grinding bushing baffle 15, there are 2 grinding bushing baffle through-holes. The grinding bushing baffle 15 is installed on the grinding clamp 14 by threaded connection; the two grinding clamps 14 at the lower part of the connecting shaft 12 and the grinding bushing baffle 15 connected to them position and support the grinding bushing 13, and the two grinding clamps 14 at the upper part of the connecting shaft 12 and the grinding bushing baffle 15 connected to them position and clamp the grinding bushing 13. By adjusting the relative positions of the 4 grinding clamps 14 and the grinding bushing baffle 15 connected to them, the grinding bushing 13 with different heights and different diameters can be clamped; at one end of the connecting shaft 12, there is an anti-detachment baffle 16; on the anti-detachment baffle 16, there is 1 anti-detachment baffle through-hole. The anti-detachment baffle 16 is connected to one end of the connecting shaft 12 by threaded connection. The anti-detachment baffle 16 is used to prevent the grinding clamp from detaching from the connecting shaft.

[0047] The part rotation drive mechanism includes: a locking part arranged on the upper surface of the workpiece turntable 2, and the part to be ground is installed through the locking part; the locking part includes a rotating core shaft 17 arranged at the center of the workpiece turntable 2; a rotating core shaft locking nut for locking the part to be ground 4 is arranged in a matching manner on the rotating core shaft 17.

[0048] The connecting shaft 12 is fixed on the rotating bracket 10 by a locking nut 11; the rotating bracket 10 is arranged on the hollow turntable 9 through a threaded connection; the hollow turntable 9 is arranged on the balance bracket 6 through a threaded connection; the balance bracket 6 is arranged on the electric push rod 3 through a threaded connection; one end of the connecting shaft 12 is provided with an external thread, the other end of the connecting shaft 12 is provided with a connecting shaft threaded hole 12-1, and the middle part of the connecting shaft 12 is provided with a shaft shoulder and two mutually parallel guide rail planes 12-4; the shaft shoulder is arranged between the shaft section of the connecting shaft 12 for installing the grinding clamping 14 and the shaft section of the guide rail plane 12-4, and the annular end face on the side of the shaft shoulder close to the guide rail plane 12-4 is the axial positioning plane 12-3 of the connecting shaft 12; the rotating bracket 10 is provided with a rotating bracket waist-shaped groove 10-1; the width of the guide rail plane 12-4 is smaller than the width of the rotating bracket waist-shaped groove 10-1, and the guide rail plane 12-4 of the connecting shaft 12 can slide along the inner wall of the rotating bracket waist-shaped groove 10-1 of the rotating bracket 10, and the connecting shaft 12 cannot rotate in the rotating bracket waist-shaped groove 10-1; the connecting shaft threaded hole 12-1 at the end of the connecting shaft 12 is used for installing the anti-disengagement baffle 16; the precision of the width of the guide rail plane 12-4 is 5-10 μm, the parallelism of the two guide rail planes 12-4 is ≤1 μm, the connecting shaft outer circle surface 12-2 of the connecting shaft 12 is perpendicular to the axial positioning surface 12-3 of the connecting shaft 12, and the perpendicularity is ≤1 μm; The rotating bracket 10 is composed of a hollow cylinder and symmetric cuboids on both radial sides. A number of circumferentially evenly distributed counterbore holes 10-4 for connecting the rotating part of the hollow turntable 9 are arranged in the middle hollow cylinder, and the circumferentially evenly distributed counterbore holes 10-4 are evenly distributed along the circumference of the annular end face of the cylinder; the annular end face of the cylinder of the rotating bracket 10 is the plane 10-2 for installing the rotating part of the hollow turntable; the rotating bracket 10 is provided with a rotating bracket working surface 10-3, and the rotating bracket working surface 10-3 is parallel to the plane 10-2 for installing the rotating part of the hollow turntable; the two inner planes of the rotating bracket waist-shaped groove 10-1 are parallel, and the guide rail plane 12-4 of the connecting shaft 12 is in clearance fit with the rotating bracket waist-shaped groove 10-1.

[0049] The grinding bushing 13 is provided with a number of U-shaped grooves 13-7 for the grinding bushing, forming a flexible hinge structure. One grinding bushing opening 13-5 is axially provided on the side wall of the grinding bushing 13. The inner hole diameter of the grinding bushing 13 is adjusted through the grinding bushing opening 13-5. A tightening threaded hole 13-4 for the grinding bushing is provided on one end face of the grinding bushing opening 13-5. A tightening screw for the grinding bushing is arranged in the tightening threaded hole 13-4 for the grinding bushing to reduce the inner diameter of the grinding bushing 13; a swelling threaded hole 13-3 for the grinding bushing and a counterbore for the tightening screw corresponding to the tightening threaded hole 13-4 for the grinding bushing are provided on the other end face of the grinding bushing opening 13-5. A swelling screw for the grinding bushing is arranged in the swelling threaded hole 13-3 for the grinding bushing. The swelling screw for the grinding bushing is used to increase the inner diameter of the grinding bushing 13, which can match the outer circle size error of the rotary part.

[0050] The balance bracket 6 is formed by vertically connecting two flat plates. One end of the flat plate in the horizontal direction of the balance bracket 6 is provided with a balance bracket slot hole 6-5. The counterweight 5 is connected in the balance bracket slot hole 6-5 through a screw and can move and be fixed along the balance bracket slot hole 6-5; a number of threaded holes 6-1 for installing the hollow turntable base are provided at the other end of the flat plate in the horizontal direction of the balance bracket 6; a number of counterbore holes 6-4 for installing the electric push rod are provided in the middle of the flat plate in the horizontal direction of the balance bracket 6. A round hole for connecting the spring balancer 7 is provided on the vertical flat plate of the balance bracket 6.

[0051] A method for using a precision automatic grinding device for the outer cylindrical surface of a part in this embodiment includes the following steps: In this embodiment, the part to be ground 4 is a base disc, and its grinding accuracy requirement is: the grinding accuracy of the outer cylindrical surface ≤ 1 μm.

[0052] Step S1: Adjust the balance bracket 6 to be horizontal Install the workpiece turntable 2 on the marble table, and install the spring balancer bracket 8 on the two sides of the marble table 1; the spring balancer bracket 8 is connected to one end of the spring balancer 7; threadedly connect and install the base of the electric push rod 3 onto the optical platform; threadedly connect and install the balance bracket 6 onto the electric push rod 3; threadedly connect and install the counterweight 5 at one end of the balance bracket 6, threadedly connect and install the base of the hollow turntable 9 at the other end of the balance bracket 6, and connect the other end of the spring balancer 7 to the balance bracket; threadedly connect the rotating part of the hollow turntable 9 to the rotating bracket 10; install and connect the connecting shaft 12 to the rotating bracket 10 through the locking nut 11; clamp the grinding chuck 14 on the connecting shaft 12, install the grinding bushing baffle 15 onto the grinding chuck 14, and clamp the grinding bushing 13 between the grinding chuck 14 and the grinding bushing baffle 15; adjust the spring balancer 7 connected to the balance bracket 6; loosen the screw connecting the counterweight 5 and the balance bracket 6, and move the counterweight 5; twist the rotating nut of the spring balancer 7 to adjust the pulling force of the spring balancer 7; change the moments at both ends of the balance bracket 6 through the spring balancer 7 and the counterweight 5 to maintain the weight balance at both ends of the balance bracket 6, thereby adjusting the balance bracket 6 to be horizontal, and place the electronic level gauge on the upper surface 6-2 of the balance bracket 6 to measure the level of the balance bracket 6; Step S2: Align the rotation center of the rotating mandrel on the workpiece turntable As Figure 16 shown, install the stepped rotating mandrel 17 on the upper turntable of the workpiece turntable 2. One end of the rotating mandrel 17 is provided with an external thread, and the stepped end face at the other end is provided with four circumferentially evenly distributed counterbore holes; the outer circular surface 17-1 and the plane 17-2 of the rotating mandrel installation base disc are subjected to quenching treatment, and the rotating mandrel 17 is threadedly connected and installed on the workpiece turntable 2 through the counterbore holes; fix the dial indicator base on the marble table 1, the dial indicator base clamps the lever side probe 18, the lever side probe 18 contacts the outer circular surface 17-1 of the rotating mandrel installation base disc on the workpiece turntable 2, and by changing the relative position between the rotating mandrel 17 and the workpiece turntable 2, align the rotation center of the rotating mandrel 17 on the workpiece turntable 2, and then lock the screws in the four counterbore holes of the rotating mandrel 17; Step S3: Adjust the parallelism of the rotating bracket As Figure 17 shown, raise the electric push rod 3, magnetically attract a dial indicator base on the working surface 10-3 of the rotating bracket, the dial indicator base clamps the lever side probe 18, the lever side probe 18 contacts the plane 17-2 of the rotating mandrel installation base disc on the workpiece turntable 2, by rotating the hollow turntable 9, observe the reading of the lever side probe 18 measuring the end face runout of the rotating mandrel 17, and by changing the position of the counterweight 5 in the balance bracket slot 6-5 for installing the counterweight on the balance bracket 6 and the pulling force of the spring balancer 7, adjust the parallelism between the working plane 10-3 of the rotating bracket and the plane 17-2 of the rotating mandrel installation base disc on the workpiece turntable 2 to within 1 µm; Step S4: Install the base disk Install a base disk with an outer diameter of 300 mm, an inner diameter of 50 mm, and a thickness of 30 mm on the rotating mandrel 17 installed on the workpiece turntable 2. The inner hole of the base disk, the spiral precision ball bushing, and the outer circular surface of the rotating mandrel for installing the base disk are interference-fitted. Use flat washers, cross washers, and lock nuts to install the base disk on the rotating mandrel 17; Step S5: Adjust the radial runout deviation of the outer circular surface of the base disk As Figure 18 shown, magnetically mount the dial indicator on the working surface 10-3 of the rotating bracket, and let the lever side probe 18 contact the outer circular surface of the base disk. By rotating the hollow turntable 9, observe the reading of the lever side probe 18 measuring the radial runout of the outer circular surface of the base disk. By changing the relative positions of the hollow turntable 9 and the balance bracket 6 with respect to the outer circular surface of the base disk, that is, changing the relative position between the counterbore 6-4 of the electric push rod installed on the balance bracket 6 and the electric push rod 3, and adjusting the relative position between the hollow turntable 9 and the threaded hole 6-1 of the hollow turntable base, control the radial runout deviation of the rotation center of the rotating bracket 10 with respect to the outer circular surface of the base disk within 1 µm; Step S6: Install the clamping mechanism In this embodiment: The working stroke of the electric push rod 3 is 200 mm, and it is driven by a 400W servo motor with a brake. The electric push rod 3 can bear a working load of 50 kg, and a magnetic switch is used to limit the working stroke; The overall length of the balance bracket 6 is 650 mm, and the width is 130 mm. The balance bracket 6 is vertically welded by two flat plates of 45# steel. The weld is smooth and flat without bubbles. After welding, stress relief is carried out by aging. The bottom surface 6-3 of the balance bracket is finely processed. After the grinding treatment of the bottom surface 6-3 of the balance bracket, the flatness of the grinding surface is detected by using a 0-level knife-edge ruler; The balance bracket 6 is provided with four threaded holes 6-1 for installing the hollow turntable base, the balance bracket 6 is provided with 8 counterbore holes 6-4 for installing the electric push rod, and the balance bracket 6 is provided with 2 balance bracket slot holes 6-5 for installing the counterweight; The material of the rotating bracket 10 is 2Cr13. The rotating bracket 10 is composed of a hollow cylinder and a cuboid. The outer diameter of the hollow cylinder in the middle is 118 mm, the thickness is 17 mm, the inner diameter of the hollow part is 80 mm, the width of the cuboids symmetrically arranged on both radial sides is 35 mm, the thickness is 17 mm, and the length is about 190 mm. The hollow cylinder in the middle is provided with 6 evenly distributed counterbore holes 10-4 on the circumference of the rotating bracket for installing the rotating part of the hollow turntable 9. The rotating bracket 10 is provided with a waist-shaped slot 10-1 with a width of 12 mm and a length of 140 mm; The surface hardness of the waist-shaped slot 10-1, the working surface 10-3 of the rotating bracket and the plane 10-2 for installing the rotating part of the hollow turntable meets the requirements through quenching treatment. After quenching treatment, tempering treatment is carried out, and after fine processing, grinding treatment is carried out. After grinding treatment, the flatness of the grinding surface is detected by using a 0-level knife-edge ruler; The waist-shaped slot 10-1 of the rotating bracket can hold the grinding bushing 13 with an outer diameter ranging from 80 mm to 200 mm by the grinding clamp 14, and the rotating bracket 10 has a certain ability to resist bending; The material of the connecting shaft 12 is 2Cr13. The total length of the connecting shaft 12 is 140 mm. One end of the connecting shaft 12 is provided with an M10 external thread 12-5 with a length of 19 mm. The other end of the connecting shaft 12 is provided with an M5 connecting shaft threaded hole 12-1 with a depth of 18 mm. The outer diameter of the connecting shaft outer surface 12-2 of the connecting shaft 12 for installing the grinding clamp 14 is 10 mm and the length is 100 mm, which can hold the grinding bushing 13 with a clamping height range from 32 mm to 100 mm by the grinding clamp 14. The connecting shaft outer surface 12-2 is electroplated with hard chromium; A section of shaft shoulder and guide rail plane 12-4 is provided in the middle of the connecting shaft 12. The diameter of the shaft shoulder is 25 mm. There is an annular surface of the shaft shoulder as the axial positioning plane 12-3 of the connecting shaft 12. The width of the guide rail plane 12-4 of the connecting shaft 12 is 12 mm and the length is 16 mm; The axial positioning plane 12-3 and the guide rail plane 12-4 are quenched, and after quenching, tempering treatment is carried out, and the surface of the quenched treatment is ground; The perpendicularity between the axial positioning plane 12-3 and the connecting shaft outer surface 12-2 is detected, and the perpendicularity between the axial positioning plane 12-3 and the guide rail plane 12-4 is detected;The width of the guide rail plane 12-4 is less than the width of the waist-shaped slot 10-1 of the rotating bracket, and the tolerances of the two are within a certain range to ensure the clearance fit between the guide rail plane 12-4 and the waist-shaped slot 10-1 of the rotating bracket; the material of the grinding clamp 14 is 2Cr13, the thickness of a single grinding clamp 14 is 16 mm, the overall grinding clamp with a thickness of 32 mm is integrally cut by wire electrical discharge machining, and then the overall grinding clamp with a thickness of 32 mm is cut in half by wire electrical discharge machining; the grinding clamp 14 is provided with two V-shaped positioning surfaces with a large angle of 160°, and polyurethane pads are pasted on the V-shaped positioning surfaces with a large angle of 160° of the grinding clamp 14, such as; Figure 7 as shown; a through hole with a high precision of 10 mm in diameter is provided at the rear of the grinding clamp 14, and a grinding clamp through hole opening 14-2 with a width of 1 mm is provided on the side wall of the through hole along the axial direction, so as to form a C-shaped annular through hole 14-3. A grinding clamp clamping through hole 14-7 with a diameter of 4.3 mm is provided on the side wall of the C-shaped annular through hole 14-3, and a grinding clamp clamping threaded hole 14-5 of M4 is provided on the other side wall of the C-shaped annular through hole 14-3. A grinding clamp tightening screw is arranged in the grinding clamp clamping threaded hole 14-5, and the two cross sections of the opening of the C-shaped annular through hole 14-3 are tightened by the grinding clamp screw to change the inner diameter of the C-shaped annular through hole 14-3 to clamp the connecting shaft 12; two grinding clamp U-shaped grooves 14-6 and the C-shaped annular through hole 14-3 are provided at the rear of the grinding clamp 14 to form a flexible hinge to clamp the connecting shaft 12; the grinding clamp 14 is provided with 4 mounting grinding bushing baffle threaded holes 14-1; the grinding bushing baffle 15 is installed on the grinding clamp 14 with screws. The grinding bushing baffle 15 is 2 mm wider than the grinding clamp polyurethane surface 14-4 formed after the grinding clamp adheres to the polyurethane elastic pad. The part of the bottom surface of the grinding bushing baffle 15 protruding from the side wall of the grinding clamp 14 and the grinding clamp polyurethane surface 14-4 form an L-shaped structure, such as Figure 12 as shown; the C-shaped annular through holes 14-3 with a diameter of 10 mm of the four grinding clamps 14 are respectively installed on the outer cylindrical surface 12-2 of the connecting shafts 12 with a diameter of 10 mm in pairs, the tightening screws of the grinding clamp clamping threaded holes 14-5 are locked, and the anti-disengagement baffle 16 at one end of the connecting shaft 12 is installed; the lock nut 11 is loosened until the guide rail plane 12-4 of the connecting shaft 12 can slide in the waist-shaped slot 10-1 of the rotating bracket, and the tightening screws of the grinding clamp clamping threaded holes 14-5 are loosened so that the C-shaped annular through hole 14-3 of the grinding clamp 14 can rotate on the outer cylindrical surface 12-2 of the connecting shaft; Step S7: Position and clamp the grinding bushing The material of the grinding bushing 13 is nodular cast iron. The outer diameter of the grinding bushing 13 is 360 mm, the inner diameter is 300 mm, and the thickness is 60 mm. The grinding bushing 13 is provided with a number of U-shaped grooves 13-7 of the grinding bushing to form a flexible hinge; a 3-mm opening 13-5 of the grinding bushing is provided along the axial direction on the side wall of the grinding bushing 13. The inner hole diameter of the grinding bushing 13 can be adjusted through the opening 13-5 of the grinding bushing. At both ends of one cross-section of the opening 13-5 of the grinding bushing, one M5 tightening threaded hole 13-4 of the grinding bushing is provided. A tightening screw of the grinding bushing is arranged in the tightening threaded hole 13-4 of the grinding bushing for tightening the grinding bushing 13; on another cross-section of the opening 13-5 of the grinding bushing, an M5 expanding threaded hole 13-3 corresponding to the tightening threaded hole 13-4 of the grinding bushing and an M5 counterbore are provided. An expanding screw of the grinding bushing is arranged in the expanding threaded hole 13-3 of the grinding bushing. The expanding screw of the grinding bushing is used to expand the grinding bushing, so as to adjust the size of the inner hole diameter of the grinding bushing 13; after the grinding bushing 13 is turned, the inner hole surface 13-1 of the grinding bushing is ground, and the opening 13-5 of the grinding bushing and the U-shaped groove 13-7 of the grinding bushing are cut by wire electrical discharge machining; as Figure 15 shown: Install the inner hole surface 13-1 of the grinding bushing onto the outer circular surface of the base disc, apply a grinding agent on the outer circular surface of the base disc, slide the grinding bushing 13 reciprocally up and down along the outer circular surface of the base disc, and adjust the two M5 tightening screws and one M5 expanding threaded screw of the grinding bushing 13 to make the grinding bushing 13 have a proper tightness with the base disc, and the inner hole surface 13-1 of the grinding bushing and the outer circular surface of the base disc are in clearance fit; press two grinding bushing baffles 15 installed at the lower part of the connecting shaft 12 tightly against the end face 13-6 of the grinding bushing, press the polyurethane surface 14-4 of the grinding clamp tightly against the outer circular surface 13-2 of the grinding bushing, and tighten the tightening screws in the two clamping threaded holes 14-5 of the grinding clamp installed at the lower part of the connecting shaft 12; press two grinding bushing baffles 15 installed at the upper part of the connecting shaft 12 tightly against the end face 13-6 of the grinding bushing, press the polyurethane surface 14-4 of the grinding clamp tightly against the outer circular surface 13-2 of the grinding bushing, and tighten the tightening screws in the clamping threaded holes 14-5 of the two grinding clamps 14 installed at the upper part of the connecting shaft 12; position and clamp the grinding bushing 13 by the two groups of grinding bushing baffles 15 and grinding clamps 14 on the upper and lower parts of the connecting shaft 12; Step S8: Fix and connect the connecting shaft 12 and the rotating bracket 10 Manually lock the lock nut 11 to make the axial positioning plane 12-3 closely adhere to the working plane 10-3 of the rotating bracket; Step S9: Grind the outer circular surface of the base disc Apply abrasive on the outer circular surface of the base disk, and rotate the hollow turntable 9 and the workpiece turntable 2; the hollow turntable 9 drives the grinding bushing 13 to make a rotational motion; the workpiece turntable 2 drives the base disk to make a rotational motion; the electric push rod 3 drives the grinding bushing 13 to make a reciprocating up and down motion. The rotational speed of the hollow turntable 9 and the rotational speed of the workpiece turntable 2 are relatively prime to each other, so that the motion trajectories of the outer circular surface of the base disk and the inner hole surface 13-1 of the grinding bushing are inconsistent, and the rotational motion directions of the two are opposite; the electric push rod 3 makes a reciprocating up and down motion, and a magnetic switch is used to limit the stroke of the reciprocating up and down motion of the electric push rod 3; during the grinding process, abrasive is added from the end of the U-shaped groove 13-7 of the grinding bushing. After grinding for a period of time, the grinding bushing 13 is turned over and reinstalled to make the grinding bushing 13 grind the outer circular surface of the base disk more evenly; continue to grind the outer circular surface of the base disk until the grinding is completed.

[0053] As described above, only the preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A device for automatic precision grinding of the outer cylindrical surface of a part, characterized in that: include: A marble table (1), wherein a part rotation driving mechanism for driving a part to be ground (4) to rotate is provided on the marble table (1); A grinding sleeve (13) for grinding a part to be ground; a clamping mechanism for clamping the grinding sleeve (13); the clamping mechanism is connected to a vertical reciprocating motion driving mechanism for driving the grinding sleeve (13) to reciprocate in a vertical direction and a grinding sleeve rotation driving mechanism for driving the grinding sleeve (13) to rotate; the clamping mechanism is also provided with a balancing mechanism for adjusting the grinding posture of the grinding sleeve (13); The balancing mechanism comprises: a spring balancer bracket (8); the spring balancer bracket (8) is arranged on a marble table (1); a spring balancer (7) is arranged on the spring balancer bracket (8); the spring balancer (7) is connected to the balancing bracket (6); a counterweight (5) is arranged at one end of the balancing bracket (6) and is connected to a vertical reciprocating motion driving mechanism; the other end of the balancing bracket (6) is connected to a grinding sleeve rotation driving mechanism; the spring balancer (7) cooperates with the counterweight (5) to adjust the horizontality of the balancing bracket (6).

2. The automatic precision grinding device for outer cylindrical surface of a part according to claim 1 is characterized in that: The vertical reciprocating motion mechanism comprises: an electric push rod (3); the electric push rod (3) drives the grinding shaft sleeve (13) to perform up and down reciprocating motion, and the base of the electric push rod (3) is arranged on the optical platform through a threaded connection; and the telescopic rod of the electric push rod (3) is connected to one end of the balance bracket (6).

3. The automatic precision grinding device for outer cylindrical surface of a part according to claim 2 is characterized in that: The grinding sleeve rotation drive mechanism comprises: a hollow turntable (9), the base of the hollow turntable (9) is connected to one end of a balancing bracket (6), and the rotating part of the hollow turntable (9) is connected to a rotating bracket (10).

4. The automatic precision grinding device for outer cylindrical surface of a part according to claim 3 is characterized in that: The clamping mechanism comprises: four grinding clamps (14); the four grinding clamps (14) are divided into two groups, arranged in pairs opposite to each other and arranged along the axial direction of the grinding shaft sleeve (13) to fix the position of the grinding shaft sleeve (13); two connecting shafts (12) are respectively arranged between the upper and lower groups of grinding clamps (14) along the vertical direction; the grinding clamps (14) can be moved and fixed along the connecting shafts (12) along the vertical direction; the rotating bracket (10) is connected between the two connecting shafts (12); the two connecting shafts (12) can be moved and fixed along the horizontal direction of the rotating bracket (10); one end of the connecting shaft (12) is threadedly connected to a locking nut (11); the connecting shaft (12) is arranged on the rotating bracket (10) through the locking nut (11); The grinding clamp (14) positions and clamps the grinding sleeve (13) to rotate under the drive of the hollow turntable (9); the grinding clamp (14) is provided with a C-shaped annular through hole (14-3) for clamping the connecting shaft (12) and a grinding clamp through hole opening (14-2); the C-shaped annular through hole (14-3) is connected to the grinding clamp through hole opening (14-2); the C-shaped annular through hole (14-3) is used to clamp the grinding clamp (14) on the connecting shaft (12); a grinding clamp clamping through hole (14-7) is provided on one side of the grinding clamp through hole opening (14-2); and a grinding clamp clamping through hole (14-7) is provided on the other side of the grinding clamp through hole opening (14-2). A threaded hole (14-5) is provided in the grinding clamp clamping threaded hole (14-5), and a grinding clamp tightening screw is provided in the grinding clamp clamping threaded hole (14-5) for tightening the C-shaped annular through hole (14-3) of the grinding clamp (14); a grinding clamp U-shaped groove (14-6) is provided on the side wall of the grinding clamp (14), and a flexible hinge structure is formed with the C-shaped annular through hole (14-3) and the grinding clamp through hole opening (14-2), so as to clamp the connecting shaft (12); a grinding sleeve baffle (15) is provided on the grinding clamp (14) for vertically positioning the grinding sleeve (13), and the grinding clamp (14) is provided with two large-angle positioning surfaces that are in line contact with the side wall of the grinding sleeve (13), and the large-angle positioning surfaces are respectively in line contact with the side wall of the grinding sleeve (13). After the elastic pad is pasted on the surface, a grinding clamp elastic pad surface is formed. The total thickness of the grinding clamp (14) after the elastic pad is pasted is smaller than the width of the grinding shaft sleeve baffle (15). The part of the bottom surface of the grinding shaft sleeve baffle (15) protruding from the side wall of the grinding clamp (14) forms an L-shaped structure with the grinding clamp elastic pad surface. The grinding clamp (14) is provided with a threaded hole for installing the grinding shaft sleeve baffle (15); the grinding shaft sleeve baffle (15) is provided with a grinding shaft sleeve baffle through hole, and the grinding shaft sleeve baffle (15) is installed on the grinding clamp (14) through a threaded connection; the two grinding clamps (14) at the lower part of the connecting shaft (12) and the grinding shaft sleeve baffle (15) connected thereto are positioned to support The grinding sleeve (13) is supported, two grinding clamps (14) on the upper part of the connecting shaft (12) and a grinding sleeve baffle (15) connected thereto are used to position and clamp the grinding sleeve (13), and the relative positions of the four grinding clamps and the grinding sleeve baffle (15) connected thereto are adjusted, thereby clamping grinding sleeves (13) of different heights and grinding sleeves (13) of different diameters; an anti-detachment baffle (16) is provided at one end of the connecting shaft (12); an anti-detachment baffle through hole is provided on the anti-detachment baffle (16), and the anti-detachment baffle (16) is connected to one end of the connecting shaft (12) by means of threads, and the anti-detachment baffle (16) is used to prevent the grinding clamp (14) from detaching from the connecting shaft (12).

5. The automatic precision grinding device for outer cylindrical surface of a part according to claim 4 is characterized in that: The part rotation driving mechanism comprises: a locking part arranged on the upper surface of a workpiece turntable (2), through which the part to be ground is installed; the locking part comprises a rotating mandrel (17) arranged at the center of the workpiece turntable (2); and a rotating mandrel locking nut for locking the part to be ground (4) is provided on the rotating mandrel (17).

6. The automatic precision grinding device for outer cylindrical surface of a part according to claim 5, characterized in that: The connecting shaft (12) is fixed to the rotating bracket (10) through a locking nut (11); the rotating bracket (10) is arranged on the hollow turntable (9) through a threaded connection; the hollow turntable (9) is arranged on the balancing bracket (6) through a threaded connection; the balancing bracket (6) is arranged on the electric push rod (3) through a threaded connection; an external thread is arranged at one end of the connecting shaft (12); a connecting shaft threaded hole (12-1) is arranged at the other end of the connecting shaft (12); a shaft shoulder and two mutually parallel guide rail planes (12-4) are arranged in the middle of the connecting shaft (12); the shaft shoulder is arranged between the shaft section of the connecting shaft (12) where the grinding clamp (14) is installed and the shaft section of the guide rail plane (12-4); The annular end surface of the shoulder close to the guide plane (12-4) is the axial positioning plane (12-3) of the connecting shaft (12); the rotating bracket (10) is provided with a rotating bracket waist groove (10-1); the width of the guide plane (12-4) is smaller than the width of the rotating bracket waist groove (10-1); the guide plane (12-4) of the connecting shaft (12) can slide along the inner wall of the rotating bracket waist groove (10-1) of the rotating bracket (10); the connecting shaft threaded hole (12-1) at the end of the connecting shaft (12) is used to install an anti-drop baffle (16); the connecting shaft outer cylindrical surface (12-2) of the connecting shaft (12) is perpendicular to the axial positioning plane (12-3) of the connecting shaft (12); The rotating bracket (10) is composed of a hollow cylinder and a rectangular parallelepiped that is symmetrical on both sides of the radial direction. The hollow cylinder in the middle is provided with a plurality of circumferentially evenly distributed countersunk holes (10-4) for connecting the rotating part of the hollow turntable (9), and the circumferentially evenly distributed countersunk holes (10-4) are evenly distributed along the circumference of the cylindrical annular end surface; the cylindrical annular end surface of the rotating bracket (10) is a plane (10-2) for mounting the rotating part of the hollow turntable; a rotating bracket working surface (10-3) is provided on the rotating bracket (10), and the rotating bracket working surface (10-3) is parallel to the plane (10-2) for mounting the rotating part of the hollow turntable; two planes on the inner side of the rotating bracket waist groove (10-1) are parallel, and the guide rail plane (12-4) of the connecting shaft (12) is clearance-matched with the rotating bracket waist groove (10-1).

7. The automatic precision grinding device for outer cylindrical surface of a part according to claim 6, characterized in that: A plurality of grinding sleeve U-shaped grooves (13-7) are provided on the grinding sleeve (13) to form a flexible hinge structure; a grinding sleeve opening (13-5) is provided on the side wall of the grinding sleeve (13) along the axial direction; the grinding sleeve (13) adjusts the inner hole diameter of the grinding sleeve (13) through the grinding sleeve opening (13-5); a grinding sleeve tightening threaded hole (13-4) is provided on one end surface of the grinding sleeve opening (13-5); a grinding sleeve tightening screw is provided in the grinding sleeve tightening threaded hole (13-4) for reducing the inner diameter of the grinding sleeve (13); a grinding sleeve expansion screw and a grinding sleeve tightening countersunk hole corresponding to the grinding sleeve tightening threaded hole (13-4) are provided on the other end surface of the grinding sleeve opening (13-5); a grinding sleeve expansion screw is provided in the grinding sleeve expansion threaded hole (13-3); and the grinding sleeve expansion screw is used to expand the inner diameter of the grinding sleeve (13).

8. The automatic precision grinding device for outer cylindrical surface of a part according to claim 7, characterized in that: The balancing bracket (6) is formed by two plates connected vertically. A balancing bracket slot (6-5) is provided on one end of the plate in the horizontal direction of the balancing bracket (6). The counterweight (5) is connected in the balancing bracket slot (6-5) by screws and can be moved and fixed along the balancing bracket slot (6-5). A plurality of threaded holes (6-1) for mounting a hollow turntable base are provided on the other end of the plate in the horizontal direction of the balancing bracket (6). A plurality of countersunk holes (6-4) for mounting an electric push rod are provided in the middle of the plate in the horizontal direction of the balancing bracket (6). A circular hole for connecting a spring balancer (7) is provided on the plate in the vertical direction of the balancing bracket (6).

9. The method for using the device for automatic precision grinding of the outer cylindrical surface of a part according to claim 8, characterized in that: The following steps are involved: Step S1: Adjust the balance bracket (6) to a level position. The workpiece turntable (2) is installed on the marble table, and the spring balancer bracket (8) is installed on the two sides of the marble table (1); the spring balancer bracket (8) is connected to one end of the spring balancer (7); the base of the electric push rod (3) is threadedly connected and installed on the optical platform; the balance bracket (6) is threadedly connected and installed on the electric push rod (3); the counterweight (5) is threadedly connected and installed on one end of the balance bracket (6), and the other end of the balance bracket (6) is threadedly connected and installed on the base of the hollow turntable (9), and the other end of the spring balancer (7) is connected to the balance bracket; the rotating part of the hollow turntable (9) is threadedly connected to the rotating bracket (10); the connecting shaft (12) and the rotating bracket are installed through the locking nut (11) (10); clamping the grinding clamp (14) on the connecting shaft (12), installing the grinding sleeve baffle (15) on the grinding clamp (14), and clamping the grinding sleeve (13) between the grinding clamp (14) and the grinding sleeve baffle (15); adjusting the spring balancer (7) connected to the balancing bracket (6); loosening the screws locking the counterweight (5) and the balancing bracket (6), and moving the counterweight (5); twisting the rotating nut of the spring balancer (7) to adjust the tension of the spring balancer (7); changing the torque at both ends of the balancing bracket (6) through the spring balancer (7) and the counterweight (5) to maintain the weight balance at both ends of the balancing bracket (6), thereby adjusting the balancing bracket (6) to a horizontal position; Step S2: Locate the rotation center of the rotating mandrel on the workpiece turntable A rotating mandrel (17) with a step is installed on the upper turntable of the workpiece turntable (2), one end of the rotating mandrel (17) is provided with an external thread, and the other end of the step end face is provided with four countersunk holes evenly distributed around the circumference; the rotating mandrel (17) is installed on the workpiece turntable (2) through the countersunk holes threaded connection; a table base is fixed on the marble table (1), the table base clamps the lever side probe (18), the lever side probe (18) contacts the rotating mandrel on the workpiece turntable (2) to install the outer cylindrical surface (17-1) of the part to be ground, and by changing the relative position of the rotating mandrel (17) and the workpiece turntable (2), the rotation center of the rotating mandrel (17) on the workpiece turntable (2) is aligned, and then the screws in the four countersunk holes of the rotating mandrel (17) are locked; Step S3: Adjust the parallelism of the rotating bracket The electric push rod (3) is raised, and a table seat is magnetically attracted to the working surface (10-3) of the rotating bracket. The table seat clamps the lever side probe (18), and the lever side probe (18) contacts the rotating mandrel on the workpiece turntable (2) to install the surface (17-2) of the part to be ground. By rotating the hollow turntable (9), the indication of the end face runout of the rotating mandrel (17) measured by the lever side probe (18) is observed. By changing the position of the balance bracket slot hole (6-5) where the counterweight (5) is installed on the balance bracket (6) and the tension of the spring balancer (7), the parallelism between the working surface (10-3) of the rotating bracket and the surface (17-2) of the part to be ground on the rotating mandrel on the workpiece turntable (2) is adjusted to within 1µm; Step S4: Install the parts to be ground (4) The part to be ground (4) is mounted on a rotating mandrel (17) mounted on a workpiece turntable (2), the inner hole of the part to be ground (4), the spiral bead sleeve and the outer cylindrical surface (17-1) of the part to be ground mounted on the rotating mandrel are interference-fitted, and the part to be ground (4) is mounted on the rotating mandrel (17) using a flat washer, a cross washer and a locking nut; Step S5: Adjust the radial runout deviation of the outer cylindrical surface of the part to be ground On the magnetic table seat of the rotating bracket working surface (10-3), the lever side probe (18) contacts the outer cylindrical surface (4-1) of the part to be ground, and by rotating the hollow turntable (9), the radial runout indication of the outer cylindrical surface (4-1) of the part to be ground measured by the lever side probe (18) is observed. By changing the relative positions of the hollow turntable (9) and the balancing bracket (6) and the outer cylindrical surface (4-1) of the part to be ground, that is, changing the relative positions of the mounting electric push rod countersunk hole (6-4) of the balancing bracket (6) and the electric push rod (3), the relative positions of the hollow turntable (9) and the threaded hole (6-1) of the mounting hollow turntable base are adjusted, so that the radial runout deviation of the rotation center of the rotating bracket (10) relative to the outer cylindrical surface (4-1) of the part to be ground is controlled within 1µm; Step S6: Install the clamping mechanism The grinding sleeve baffle (15) is installed on the grinding clamp (14) with screws, and the part of the bottom surface of the grinding sleeve baffle (15) protruding from the side wall of the grinding clamp (14) forms an L-shaped structure with the surface of the elastic pad. The C-shaped annular through holes (14-3) of the four grinding clamps (14) are installed two by two on the outer cylindrical surfaces (12-2) of the connecting shafts (12), and the tightening screws of the grinding clamp clamping threaded holes (14-5) are locked. The anti-slip baffle (16) at one end of the connecting shaft (12) is installed; the locking nut (11) is loosened until the guide rail plane (12-4) of the connecting shaft (12) can slide in the waist groove (10-1) of the rotating bracket, and the tightening screws of the grinding clamp clamping threaded holes (14-5) are loosened so that the C-shaped annular through holes (14-3) of the grinding clamp (14) can rotate on the outer cylindrical surface (12-2) of the connecting shaft; Step S7: Positioning and clamping the grinding sleeve Install the inner hole (13-1) of the grinding sleeve to the outer cylindrical surface (4-1) of the part to be ground, apply abrasive to the outer cylindrical surface (4-1) of the part to be ground, slide the grinding sleeve (13) back and forth along the outer cylindrical surface (4-1) of the part to be ground, and adjust the grinding sleeve tightening screw and the grinding sleeve expansion screw on the grinding sleeve (13) to make the inner hole surface (13-1) of the grinding sleeve and the outer cylindrical surface (4-1) of the part to be ground have a clearance fit; Place the two grinding sleeve baffles (15) installed at the lower part of the connecting shaft (12) tightly against the end face (13-6) of the grinding sleeve, place the surface of the grinding clamp elastic pad tightly against the outer cylindrical surface (13-2) of the grinding sleeve, and tighten the tightening screws in the two grinding clamp clamping threaded holes (14-5) at the lower part of the connecting shaft (12); place the two grinding sleeve baffles (15) installed at the upper part of the connecting shaft (12) tightly against the end face (13-6) of the grinding sleeve, place the surface of the grinding clamp elastic pad tightly against the outer cylindrical surface (13-2) of the grinding sleeve, and tighten the tightening screws in the grinding clamp clamping threaded holes (14-5) of the two grinding clamps (14) at the upper part of the connecting shaft (12); position and clamp the grinding sleeve (13) with the two sets of grinding sleeve baffles (15) and grinding clamps (14) at the upper and lower parts of the connecting shaft (12); Step S8: Fixing the connecting shaft (12) and the rotating bracket (10) Manually tighten the locking nut (11) so that the axial positioning plane (12-3) is in close contact with the working plane (10-3) of the rotating bracket; Step S9: Grinding the outer cylindrical surface of the part to be ground Abrasive is applied to the outer cylindrical surface (4-1) of the part to be ground, and the hollow turntable (9) and the workpiece turntable (2) are rotated; the hollow turntable (9) drives the grinding sleeve (13) to rotate; the workpiece turntable (2) drives the part to be ground (4) to rotate; the electric push rod (3) drives the grinding sleeve (13) to reciprocate up and down, and the rotation speed of the hollow turntable (9) and the rotation speed of the workpiece turntable (2) are mutually prime, so that the movement trajectories of the outer cylindrical surface (4-1) of the part to be ground and the inner hole surface (13-1) of the grinding sleeve are inconsistent, and the rotational directions of the two are opposite; the electric push rod (3) reciprocates up and down; during the grinding process, abrasive is added from the end of the U-shaped groove (13-7) of the grinding sleeve, and after grinding for a period of time, the grinding sleeve (13) is turned over and reinstalled, and the outer cylindrical surface (4-1) of the part to be ground is continued to be ground until the grinding is completed.

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