A precision automatic grinding device for the outer cylindrical surface of parts and its usage method

Abstract

The invention belongs to the field of precision machining technology and relates to a precise automatic grinding device for the outer cylindrical surface of a part and its use method. In the invention, a part rotation driving mechanism arranged on a marble table drives a part to be ground to rotate; a clamping mechanism clamps a grinding bushing; a vertical reciprocating motion driving mechanism and a grinding bushing rotation driving mechanism connected to the clamping mechanism drive the grinding bushing to perform vertical reciprocating motion and rotational motion respectively; and a grinding attitude of the device is adjusted through a balance mechanism arranged on the clamping mechanism, and the part to be ground is ground with the grinding bushing. The invention can correct the taper error of the outer circular surface of a workpiece, has good versatility, high flexibility, convenient operation, extremely high grinding precision and low maintenance cost, is applicable to the automatic grinding processing of ultra-precise parts such as base discs and high-precision bearings, and can realize the on-line correction of errors of 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 using method thereof. Background Art

[0002] Grinding is an ultra-precision machining process, mainly used for 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 between the grinding tool and the workpiece. Among them, the grinding tool is a rigid tool with a certain rigidity. 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 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. Outer 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 outer 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, which 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 causes the roundness of the outer circle surface of the base disk to be not high 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 Symmetric Radial Deformation Distribution

CN113245929A

[0006] In order to solve the problems of the prior art such as the complex structure and poor versatility of the precision automatic grinding device for the outer cylindrical surface of parts, unstable movement during the grinding process, inability to grind the outer circle surface evenly, low grinding precision, and inability to correct the taper error of the outer circle surface of the workpiece, 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;

[0007] a grinding bush for grinding the part to be ground; a clamping mechanism for clamping the grinding bush; a vertical reciprocating motion driving mechanism connected to the clamping 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.

[0008] 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 balance bracket; one end of the balance bracket is provided with a counterweight block and is connected to the vertical reciprocating motion driving mechanism; the other end of the balance bracket is connected to the grinding bush rotation driving mechanism; the spring balancer and the counterweight block cooperate to adjust the levelness of the balance bracket.

[0009] 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 balance bracket.

[0010] 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 balance bracket, and the rotating part of the hollow turntable is connected with a rotating bracket.

[0011] According to the above-mentioned precision automatic grinding device for the outer cylindrical surface of a part, 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.

[0012] 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 through-hole for clamping the grinding chuck, and the other side of the opening of the grinding chuck through-hole is provided with a threaded hole for clamping the grinding chuck. A tightening screw for the grinding chuck is arranged in the threaded hole for clamping 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; the grinding chuck is provided with a baffle for the grinding bushing to position the grinding bushing in the vertical direction. The grinding chuck is provided with 2 large-angle positioning surfaces that are in line contact with the side wall of the grinding bushing respectively. After the elastic pads are pasted on the large-angle positioning surfaces, an elastic pad surface of the grinding chuck is formed. The total thickness of the grinding chuck after pasting the elastic pads is smaller than the width of the baffle for the grinding bushing. The part of the bottom surface of the baffle for the grinding bushing protruding from the side wall of the grinding chuck forms an L-shaped structure with the elastic pad surface of the grinding chuck. The grinding chuck is provided with threaded holes for installing the baffle for the grinding bushing; the baffle for the grinding bushing is provided with a through-hole for the baffle for the grinding bushing, and the baffle for the grinding bushing is installed on the grinding chuck through threaded connection; the two grinding chucks at the lower part of the connecting shaft and the baffle for the grinding bushing connected to them position and support the grinding bushing, and the two grinding chucks at the upper part of the connecting shaft and the baffle for the grinding bushing connected to them position and clamp the grinding bushing. By adjusting the relative positions of the 4 grinding chucks and the baffles for the grinding bushing connected to them, grinding bushings with different heights and different diameters can be clamped; one end of the connecting shaft is provided with an anti-disengagement baffle; the anti-disengagement baffle is provided with 1 through-hole for the anti-disengagement baffle, and the anti-disengagement baffle is threadedly connected to one end of the connecting shaft. The anti-disengagement baffle is used to prevent the grinding chuck from disengaging from the connecting shaft.

[0013] According to the above-mentioned precision automatic grinding device for the outer cylindrical surface of a part, 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 rotating core shaft locking nut for locking the part to be ground is arranged in a matching manner on the rotating core shaft.

[0014] 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 through 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;

[0015] 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 circumferences of the annular end faces 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.

[0016] 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 along the axial direction on the side wall of the grinding bushing. 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; on the other end face of the grinding bushing opening, there are provided a swelling screw of the grinding bushing and a counterbored hole corresponding to the tightening threaded hole of the grinding bushing. 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 enlarging the inner diameter of the grinding bushing.

[0017] 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 block 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.

[0018] The usage method of a precision automatic grinding device for the outer cylindrical surface of a part as described above includes the following steps:

[0019] Step S1: Adjust the balance bracket to be horizontal

[0020] 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; threadedly connect the rotating part of the hollow turntable 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 sleeve baffle onto the grinding chuck, and clamp the grinding sleeve between the grinding chuck and the grinding sleeve baffle; adjust the spring balancer connected to the balance bracket; loosen the screw connecting 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, thereby adjusting the balance bracket to be horizontal;

[0021] Step S2: Align the rotation center of the rotating mandrel on the workpiece turntable

[0022] Install the 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 other end of the stepped end face 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 rotating mandrel on the workpiece turntable to install the outer cylindrical surface of the part to be ground, 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;

[0023] Step S3: Adjust the parallelism of the rotating bracket

[0024] 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 rotating mandrel on the workpiece turntable to install the plane of the part to be ground, by rotating the hollow turntable, observe the reading of the lever side probe measuring the end face runout of the rotating mandrel, and by changing the position of the counterweight block in the balance bracket slot of the balance bracket where the counterweight block is installed and the pulling force of the spring balancer, adjust the parallelism between the working plane of the rotating bracket and the plane of the rotating mandrel on the workpiece turntable where the part to be ground is installed to be within 1 µm;

[0025] Step S4: Install the part to be ground

[0026] 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. Use flat washers, cross washers, and lock nuts to install the part to be ground on the rotating mandrel;

[0027] Step S5: Adjust the radial runout deviation of the outer cylindrical surface of the part to be ground

[0028] Magnetically mount the dial indicator base on 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, by changing the relative positions of the counterbored holes of the mounting electric push rods of the balance bracket and the electric push rods, and adjusting the relative positions of the hollow turntable and the threaded holes of the hollow turntable mounting base, 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;

[0029] Step S6: Install the clamping mechanism

[0030] 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 plane of the connecting shaft can slide in the waist-shaped groove of the rotating bracket. 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;

[0031] Step S7: Position and clamp the grinding bushing

[0032] 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 tension screw and the expansion 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;

[0033] Step S8: Fix the connection shaft and the rotating bracket

[0034] Manually tighten the locking nut to make the axial positioning plane close to the working plane of the rotating bracket;

[0035] Step S9: Grinding the outer cylindrical surface of the part to be ground

[0036] Apply abrasive to 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 sleeve to rotate; the workpiece turntable drives the part to be ground to rotate; the electric push rod drives the grinding sleeve to reciprocate up and down, and the rotation speed of the hollow turntable and the workpiece turntable are mutually 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 sleeve are inconsistent, and the rotational motion directions of the two are opposite; the electric push rod reciprocates up and down; during the grinding process, abrasive is added from the end of the U-shaped groove of the grinding sleeve. After grinding for a period of time, the grinding sleeve is turned over and reinstalled, and the outer cylindrical surface of the part to be ground is continued to be ground until the grinding is completed.

[0037] The beneficial effects of the present invention are as follows:

[0038] 1. The present invention realizes the composite action of up and down reciprocating motion and rotational motion of the grinding sleeve through the connection structure of the electric push rod and the hollow turntable. The electric push rod drives the grinding sleeve to reciprocate along the axial direction of the workpiece at a high frequency, and the hollow turntable drives the grinding sleeve to rotate at a constant speed around the outer cylindrical surface of the workpiece. The rotation speeds of the two are mutually prime and opposite in direction, so that the grinding track is distributed in a complex network, avoiding the repetitive scratches caused by traditional single motion. This composite motion significantly improves the uniformity of the distribution of the abrasive on the workpiece surface and effectively eliminates the problem of uneven local wear. It is particularly suitable for the processing of ultra-precision and high-precision parts such as base discs and high-precision bearings.

[0039] 2. The L-shaped clamping structure composed of the grinding clamp and the grinding sleeve baffle of the present invention, combined with the flexible hinge structure, achieves high adaptability to grinding sleeves of different sizes. The inner diameter of the C-shaped annular through hole at the rear of the grinding clamp is adjusted by tightening the screw, and the clearance between the connecting shaft guide plane and the waist groove of the rotating bracket is matched to support the clamping of grinding sleeves of different sizes. At the same time, the 160° V-shaped positioning surface of the grinding clamp is adhered with an elastic pad, which can not only provide uniform clamping force, but also buffer vibration and avoid deformation of the sleeve caused by rigid clamping. By adjusting the spacing between the upper and lower grinding clamps of the connecting shaft and the pre-tightening force of the screws, grinding sleeves of different specifications can be quickly replaced, which significantly shortens the debugging time of the device, has good versatility, and is suitable for the flexible production needs of multiple varieties and small batches of precision parts.

[0040] 3. The connection structure of the balance bracket, the counterweight block and the spring balancer of the present invention solves the technical problem of device vibration under compound motion. The balance bracket is formed by two flat plates connected vertically. The bottom surface of the balance bracket is ground to a flatness of 0-grade blade standard to ensure rigid support; the counterweight block slides through the slot of the balance bracket to adjust the torque, 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 1μm, effectively suppressing low-frequency vibrations during the operation of the device. In addition, the parallelism of the working surface of the rotating bracket and the workpiece turntable is monitored and adjusted in real time by the lever lateral probe to further reduce the axial runout error. The contact pressure fluctuation between the grinding sleeve and the workpiece during the grinding process is greatly reduced, the surface roughness consistency is significantly improved, the processing stability is good, and the taper error of the outer cylindrical surface of the workpiece can be corrected at the same time.

[0041] 4. The grinding sleeve of the present invention adopts a combined structure of a flexible hinge and a tightening screw, which breaks through the limitation of the small rigid deformation range of the traditional sleeve. An opening is opened axially on the side wall of the sleeve, and the expansion screw and the tightening screw are used to fine-tune 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 of the sleeve evenly distributed, and the grinding pressure is transmitted more smoothly to avoid local over-grinding. In practical applications, the operator can dynamically adjust the screw preload by monitoring the lever probe data, realize online correction of the grinding error of precision parts, and improve processing accuracy.

[0042] 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 shaft sleeve baffle is fixed by threaded holes, which is easy to replace; the connecting shaft guide rail surface is hard chrome-plated to improve wear resistance. The clearance fit structure between the waist groove of the rotating bracket and the connecting shaft allows the positioning accuracy to be compensated 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 life are improved, which is particularly suitable for industrial scenarios with high-load continuous production. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a schematic diagram of the overall structure of a device for automatic precision grinding of the outer cylindrical surface of a part.

[0044] Figure 2 It is a schematic diagram of the balance support structure of the present invention.

[0045] Figure 3 The rotating bracket structure of the present invention is schematically shown in FIG. Figure 1 .

[0046] Figure 4 The rotating bracket structure of the present invention is schematically shown in FIG. Figure 2 .

[0047] Figure 5Schematic diagram of the grinding bushing structure of the present invention.

[0048] Figure 6 Schematic diagram of the connecting shaft structure of the present invention.

[0049] Figure 7 Schematic diagram of the grinding clamping structure of the present invention Figure 1 。

[0050] Figure 8 Schematic diagram of the grinding clamping structure of the present invention Figure 2 。

[0051] Figure 9 Schematic diagram of the grinding clamping structure of the present invention Figure 3 。

[0052] Figure 10 Schematic diagram of the grinding bushing baffle structure of the present invention.

[0053] Figure 11 Schematic diagram of the anti - detachment baffle structure of the present invention.

[0054] Figure 12 Schematic diagram of the installation of the grinding clamping of the present invention Figure 1 。

[0055] Figure 13 Schematic diagram of the installation of the grinding clamping of the present invention Figure 2 。

[0056] Figure 14 Schematic diagram of the lock nut structure of the present invention.

[0057] Figure 15 Schematic diagram of the installation of the grinding bushing of the present invention.

[0058] Figure 16 Schematic diagram of the working process of adjusting the radial run - out of the rotating mandrel of the present invention.

[0059] Figure 17 Schematic diagram of the working process of adjusting the end - face run - out of the balance bracket of the present invention.

[0060] Figure 18 Schematic diagram of the working process of adjusting the radial run - out of the balance bracket of the present invention.

[0061] Figure 19 Partial installation schematic diagram of a precision automatic grinding device for the outer cylindrical surface of a part of the present invention.

[0062] 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: Balance bracket; 6-1: Threaded hole for installing the base of the hollow turntable; 6-2: Upper surface of the balance bracket; 6-3: Bottom surface of the balance bracket; 6-4: Countersunk hole for installing the electric push rod; 6-5: Slot hole of the balance 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-disengagement 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 mode

[0063] 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. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0064] 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;

[0065] 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 balance mechanism for adjusting the grinding posture of the grinding bushing 13 is further arranged on the clamping mechanism.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] The clamping mechanism includes: 4 grinding clamps 14; the 4 grinding clamps 14 are divided into 2 groups, arranged in pairs and axially arranged along the grinding bushing 13 to fix the position of the grinding bushing 13; 2 connecting shafts 12 are respectively arranged in the vertical direction between the upper and lower 2 groups of grinding clamps 14; the grinding clamps 14 can move and be fixed along the connecting shafts 12 in the vertical direction; the 2 connecting shafts 12 are connected with the rotating bracket 10; the 2 connecting shafts 12 can move and be fixed in the horizontal direction along the rotating bracket 10; 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;

[0070] The grinding clamp 14 positions and clamps the grinding bushing 13, which rotates 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 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. 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 threaded hole 14-5 is provided on the other side of the grinding clamp through-hole opening 14-2. A grinding clamp tightening screw is arranged 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 arranged on the side wall of the grinding clamp 14, forming 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; a grinding bushing baffle 15 for positioning the grinding bushing 13 in the vertical direction is arranged on the grinding clamp 14. 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 protruding from the side wall of the grinding clamp 14 forms an L-shaped structure with the surface of the elastic pad. Threaded holes for installing the grinding bushing baffle 15 are arranged on the grinding clamp 14; 2 grinding bushing baffle through-holes are arranged on the grinding bushing baffle 15. 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 thereto 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 thereto 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 thereto, grinding bushings 13 with different heights and different diameters can be clamped; a retaining baffle 16 is arranged at one end of the connecting shaft 12; 1 retaining baffle through-hole is arranged on the retaining baffle 16. The retaining baffle 16 is connected to one end of the connecting shaft 12 by threaded connection. The retaining baffle 16 is used to prevent the grinding clamp from detaching from the connecting shaft.

[0071] 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.

[0072] The connecting shaft 12 is fixed on 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 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 clip 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, and 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;

[0073] 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 circumferential end face of the cylinder; the circumferential 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.

[0074] 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; on the other end face of the grinding bushing opening 13-5, a swelling threaded hole 13-3 for the grinding bushing and a counterbore for the tightening threaded hole 13-4 corresponding to the tightening threaded hole 13-4 for the grinding bushing are provided. 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 expand the inner diameter of the grinding bushing 13 and can match the outer circle dimension error of the rotary part.

[0075] 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 slot hole 6-5 for the balance bracket. The counterweight 5 is connected in the slot hole 6-5 for the balance bracket through a screw and can move and be fixed along the slot hole 6-5 for the balance bracket; several 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; several counterbored 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.

[0076] A method for using a precision automatic grinding device for the outer cylindrical surface of a part in this embodiment includes the following steps:

[0077] In this embodiment, the part 4 to be ground is a base disk, and its grinding accuracy requirement is that the grinding accuracy of the outer cylindrical surface ≤ 1 μm.

[0078] Step S1: Adjust the balance bracket 6 to be horizontal

[0079] Install the workpiece turntable 2 on the marble table, and install the spring balancer bracket 8 on 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 on 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 on the balance bracket; threadedly connect the rotating part of the hollow turntable 9 to the rotating bracket 10; install the connecting shaft 12 and 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 moment at both ends of the balance bracket 6 through the spring balancer 7 and the counterweight 5 to keep the weights at both ends of the balance bracket 6 balanced, 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;

[0080] Step S2: Align the rotation center of the rotating mandrel on the workpiece turntable

[0081] 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 circumferential surface 17-1 and the plane 17-2 of the rotating mandrel installation base disc are quenched. The rotating mandrel 17 is threadedly connected and installed on the workpiece turntable 2 through the counterbore holes; fix the dial gauge base on the marble table 1, the dial gauge base clamps the lever side measuring head 18, the lever side measuring head 18 contacts the outer circumferential 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;

[0082] Step S3: Adjust the parallelism of the rotating bracket

[0083] As Figure 17As shown, raise the electric push rod 3, magnetically attract a dial indicator base on the working surface 10-3 of the rotating bracket, clamp the side probe 18 of the lever with the dial indicator base, and the side probe 18 of the lever contacts the plane 17-2 of the mounting base disc of the rotating spindle on the workpiece turntable 2. By rotating the hollow turntable 9, observe the reading of the side probe 18 of the lever measuring the end face runout of the rotating spindle 17. By changing the position of the counterweight block 5 in the balance bracket slot 6-5 of the balance bracket for mounting the counterweight block 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 mounting base disc of the rotating spindle on the workpiece turntable 2 to within 1 µm;

[0084] Step S4: Install the base disc

[0085] Install a base disc with an outer diameter of 300 mm, an inner diameter of 50 mm, and a thickness of 30 mm on the rotating spindle 17 installed on the workpiece turntable 2. The inner hole of the base disc, the spiral precision ball bushing, and the outer cylindrical surface of the mounting base disc of the rotating spindle are in interference fit. Use flat washers, cross washers, and lock nuts to install the base disc on the rotating spindle 17;

[0086] Step S5: Adjust the radial runout deviation of the outer cylindrical surface of the base disc

[0087] As Figure 18 shown, magnetically attract the dial indicator base on the working surface 10-3 of the rotating bracket, and the side probe 18 of the lever contacts the outer cylindrical surface of the base disc. By rotating the hollow turntable 9, observe the reading of the side probe 18 of the lever measuring the radial runout of the outer cylindrical surface of the base disc. By changing the relative positions of the hollow turntable 9 and the balance bracket 6 with respect to the outer cylindrical surface of the base disc, that is, changing the relative position between the counterbore 6-4 of the balance bracket for installing the electric push rod and the electric push rod 3, and adjusting the relative position between the hollow turntable 9 and the threaded hole 6-1 of the mounting base of the hollow turntable, control the radial runout deviation of the rotation center of the rotating bracket 10 with respect to the outer cylindrical surface of the base disc within 1 µm;

[0088] Step S6: Install the clamping mechanism

[0089] 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 withstand 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 grinding the bottom surface 6-3 of the balance bracket, the flatness of the grinding surface is detected by using a 0-level knife-edge straightedge. 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 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 are heat-treated to make the surface hardness meet the requirements. After heat treatment, tempering treatment is carried out. 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 straightedge. 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 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 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 heat-treated. After heat treatment, tempering treatment is carried out. The surface of the heat-treated part is ground. Detect the perpendicularity between the axial positioning plane 12-3 and the connecting shaft surface 12-2, and detect the perpendicularity between the axial positioning plane 12-3 and the guide rail plane 12-4.The width of the guide rail plane 12-4 is less than the width of the waist-shaped groove 10-1 of the rotating bracket, and the tolerances of the two are within a certain range to ensure clearance fit between the guide rail plane 12-4 and the waist-shaped groove 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, an integral grinding clamp with a thickness of 32 mm is integrally cut by wire electrical discharge machining, and then the integral 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 at the opening of the C-shaped annular through hole 14-3 are tightened by the grinding clamp screw, so as 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 mounted on the grinding clamp 14 with screws, and 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 where the bottom surface of the grinding bushing baffle 15 protrudes from the side wall of the grinding clamp 14 forms an L-shaped structure with the grinding clamp polyurethane surface 14-4, 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 mounted on the outer circular surface 12-2 of the connecting shaft with a diameter of 10 mm of the two connecting shafts 12 in pairs, the tightening screws of the grinding clamp clamping threaded holes 14-5 are locked, and the anti-detachment baffle 16 at one end of the connecting shaft 12 is mounted; the lock nut 11 is loosened until the guide rail plane 12-4 of the connecting shaft 12 can slide in the waist-shaped 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 hole 14-3 of the grinding clamp 14 can rotate on the outer circular surface 12-2 of the connecting shaft;

[0090] Step S7: Position and clamp the grinding bushing

[0091] 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 for the grinding bushing to form a flexible hinge. Along the axial direction, a 3-mm opening 13-5 for the grinding bushing is provided on the side wall of the grinding bushing 13. The inner hole diameter of the grinding bushing 13 can be adjusted through this opening 13-5 for the grinding bushing. At both ends of one section of the opening 13-5 for the grinding bushing, one M5 tightening threaded hole 13-4 for the grinding bushing is provided respectively. A tightening screw for the grinding bushing is arranged in the tightening threaded hole 13-4 for the grinding bushing to tighten the grinding bushing 13. On another section of the opening 13-5 for the grinding bushing, an M5 expanding threaded hole 13-3 for the grinding bushing and an M5 counterbore corresponding to the tightening threaded hole 13-4 for the grinding bushing are provided. An expanding screw for the grinding bushing is arranged in the expanding threaded hole 13-3 for the grinding bushing. The expanding screw for 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. The opening 13-5 for the grinding bushing and the U-shaped groove 13-7 for 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 circle surface of the base disc. Apply grinding agent on the outer circle surface of the base disc. Slide the grinding bushing 13 reciprocally up and down along the outer circle surface of the base disc. Adjust the 2 M5 tightening screws for the grinding bushing and 1 M5 expanding threaded screw on 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 has a clearance fit with the outer circle surface of the base disc. Press the 2 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 circle surface 13-2 of the grinding bushing, and tighten the tightening screws in the 2 clamping threaded holes 14-5 of the grinding clamp installed at the lower part of the connecting shaft 12. Press the 2 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 circle surface 13-2 of the grinding bushing, and tighten the tightening screws in the clamping threaded holes 14-5 of the 2 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 at the upper and lower parts of the connecting shaft 12;

[0092] Step S8: Fix and connect the connecting shaft 12 and the rotating bracket 10

[0093] 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;

[0094] Step S9: Grind the outer circle surface of the base disc

[0095] 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 motion up and down. The rotational speed of the hollow turntable 9 and the rotational speed of the workpiece turntable 2 are relatively prime, 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 directions of their rotational motions are opposite; the electric push rod 3 makes a reciprocating motion up and down, and uses a magnetic switch to limit the stroke of the reciprocating motion of the electric push rod 3 up and down; during the grinding process, add abrasive from the end of the U-shaped groove 13-7 of the grinding bushing. After grinding for a period of time, turn the grinding bushing 13 over and reinstall it 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.

[0096] 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 precision automatic grinding device for the outer cylindrical surface of a part, characterized in that, Comprising: A marble table (1) with a part rotation drive mechanism provided above it; A clamping mechanism for clamping the grinding bushing (13), on which there is a vertical reciprocating motion mechanism for driving the grinding bushing (13) to move vertically and a grinding bushing rotation drive mechanism for driving the grinding bushing (13) to rotate; there is also a balance mechanism on the clamping mechanism for adjusting the grinding posture of the grinding bushing (13); The balance mechanism includes: a spring balancer bracket (8); the spring balancer bracket (8) is provided on the marble table (1); a spring balancer (7) is provided on the spring balancer bracket (8); the spring balancer (7) is connected to the balance bracket (6); one end of the balance bracket (6) is provided with a counterweight (5) and is connected to the vertical reciprocating motion mechanism; the other end of the balance bracket (6) is connected to the grinding bushing rotation drive mechanism; the spring balancer (7) cooperates with the counterweight (5) to adjust the levelness of the balance bracket (6); The grinding bushing rotation drive mechanism includes a hollow turntable (9), the base of the hollow turntable (9) is connected to one end of the balance bracket (6), and the rotating part of the hollow turntable (9) is connected with a rotating bracket (10); The clamping mechanism includes 4 grinding chucks (14), which are divided into 2 groups and are sleeved on 2 connecting shafts (12) in pairs and can move up and down along the connecting shafts (12) and be fixed; a rotating bracket (10) is connected between the 2 connecting shafts (12); the 2 connecting shafts (12) can move horizontally along the rotating bracket (10) and be fixed; the top of the connecting shaft (12) is arranged on the rotating bracket (10) through a locking nut (11); The grinding chuck (14) clamps the grinding bushing (13) and makes a rotating motion driven by the hollow turntable (9); there is an annular through hole (14-3) for installing the connecting shaft (12) on the grinding chuck (14); there is a grinding bushing baffle (15) for positioning the grinding bushing (13) in the vertical direction on the grinding chuck (14), the grinding chuck (14) is provided with 2 large-angle positioning surfaces that are in line contact with the side wall of the grinding bushing (13), the bottom surface of the grinding bushing baffle (15) protrudes from the side wall of the grinding chuck (14), and there is a threaded hole for installing the grinding bushing baffle (15) on the grinding chuck (14); the two grinding chucks (14) at the lower part of the connecting shaft (12) and the grinding bushing baffle (15) connected thereto support the grinding bushing (13), the two grinding chucks (14) at the upper part of the connecting shaft (12) and the grinding bushing baffle (15) connected thereto clamp the grinding bushing (13), and the relative positions of the 4 grinding chucks and the grinding bushing baffle (15) connected thereto are adjusted to clamp grinding bushings (13) with different heights and different diameters; an anti-disengagement baffle (16) is threadedly connected to one end of the connecting shaft (12) to prevent the grinding chuck (14) from disengaging from the connecting shaft (12).

2. The precision automatic grinding device for the outer cylindrical surface of a part according to claim 1, wherein The vertical reciprocating motion drive mechanism includes: an electric push rod (3); the electric push rod (3) drives the grinding bushing (13) to make a reciprocating up and down motion, 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 to one end of the balance bracket (6).

3. The precision automatic grinding device for the outer cylindrical surface of a part according to claim 2, characterized in that, The part rotation drive mechanism includes: a locking part disposed 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) disposed 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).

4. A precision automatic grinding device for the outer cylindrical surface of a part according to claim 3, characterized in that, The connecting shaft (12) is fixed on 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 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 clamp (14) and the shaft section of the guide rail plane (12-4), and the annular end face of the shaft shoulder close to the guide rail plane (12-4) is the axial positioning plane (12-3) of the connecting shaft (12); a rotating bracket waist-shaped groove (10-1) is arranged on the rotating bracket (10); 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 threaded hole (12-1) at the end of the connecting shaft (12) is used for installing an anti-disengagement baffle (16); the 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 rectangular parallelepipeds symmetrically arranged 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 circumferentially evenly distributed along 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; a rotating bracket working surface (10-3) is arranged on the rotating bracket (10), 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).

5. The precision automatic grinding device for the outer cylindrical surface of a part according to claim 4, characterized in that, The grinding bushing (13) is provided with a number of U-shaped grooves (13-7) for grinding bushings, forming a flexible hinge structure. There is 1 grinding bushing opening (13-5) arranged axially 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 arranged 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) of the grinding bushing, which is used to reduce the inner diameter of the grinding bushing (13); an expanding threaded hole (13-3) for the grinding bushing and a counterbore for the tightening threaded hole (13-4) of the grinding bushing corresponding to it are arranged on the other end face of the grinding bushing opening (13-5). An expanding screw for the grinding bushing is arranged in the expanding threaded hole (13-3) of the grinding bushing, and the expanding screw for the grinding bushing is used to increase the inner diameter of the grinding bushing (13).

6. The precision automatic grinding device for the outer cylindrical surface of a part according to claim 5, characterized in that, 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) by screws and can move and be fixed along the balance bracket slot hole (6-5); several threaded holes (6-1) for installing the hollow turntable base are arranged at the other end of the flat plate in the horizontal direction of the balance bracket (6); several counterbores (6-4) for installing the electric push rod are arranged 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 arranged on the vertical flat plate of the balance bracket (6).

7. The usage method of a precision automatic grinding device for the outer cylindrical surface of a part according to claim 6, characterized in that, It includes the following steps: 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 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, 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 shaft (12) and the rotating bracket (10) through the lock nut (11); clamp the grinding clamp (14) on the connecting shaft (12), install the grinding bushing baffle (15) onto the grinding clamp (14), and clamp the grinding bushing (13) between the grinding clamp (14) and the grinding bushing baffle (15); adjust the spring balancer (7) connected to the balance bracket (6); loosen the screw locking 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 moment at both ends of the balance bracket (6) through the spring balancer (7) and the counterweight (5) to keep the weights at both ends of the balance bracket (6) balanced, so as to adjust the balance bracket (6) to be horizontal; Step S2: Align the rotation center of the rotating mandrel on the workpiece turntable Install a 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 rotating mandrel (17) is installed on the workpiece turntable (2) by threaded connection through the counterbore holes; fix a surface seat on the marble table (1), the surface seat clamps the lever side probe (18), and the lever side probe (18) contacts the outer circle surface (17-1) of the part to be ground installed on the rotating mandrel on the workpiece turntable (2). 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 Raise the electric push rod (3), magnetically attract a surface seat on the working surface (10-3) of the rotating bracket, the surface seat clamps the lever side probe (18), and the lever side probe (18) contacts the plane (17-2) of the part to be ground installed on the rotating mandrel 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). By changing the position of the counterweight block (5) in the balance bracket slot hole (6-5) of the balance bracket (6) for installing the counterweight block 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 part to be ground installed on the rotating mandrel on the workpiece turntable (2) to within 1μm; Step S4: Install the part to be ground (4) Install the part to be ground (4) on the rotating mandrel (17) installed on the workpiece turntable (2). The inner hole of the part to be ground (4), the spiral precision ball bushing and the outer circle surface (17-1) of the part to be ground installed on the rotating mandrel are in interference fit. Use flat washers, cross washers and lock nuts to install the part to be ground (4) on the rotating mandrel (17); Step S6: Adjust the radial runout deviation of the outer circle surface of the part to be ground Magnetically attract a surface seat on the working surface (10-3) of the rotating bracket, and the lever side probe (18) contacts the outer circle surface (4-1) of the part to be ground. By rotating the hollow turntable (9), observe the reading of the lever side probe (18) measuring the radial runout of the outer circle surface (4-1) of the part to be ground. By changing the relative positions of the hollow turntable (9) and the balance bracket (6) with respect to the outer circle surface (4-1) of the part to be ground, that is, changing the relative position between the counterbore hole (6-4) for installing the electric push rod of 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 base for installing the hollow turntable, control the radial runout deviation of the rotation center of the rotating bracket (10) with respect to the outer circle surface (4-1) of the part to be ground within 1μm; Step S8: Install the clamping mechanism Install the grinding bushing baffle (15) on the grinding chuck (14) with screws. The bottom surface of the grinding bushing baffle (15) protrudes from the side wall of the grinding chuck (14). Fix the C-shaped annular through holes (14-3) of the four grinding chucks (14) to the outer cylindrical surface (12-2) of the two connecting shafts (12) in pairs, and install the anti-loosening baffle (16) at one end of the connecting shaft (12); Loosen the lock nut (11) until the guide plane (12-4) of the connecting shaft (12) can slide within the waist-shaped groove (10-1) of the rotating bracket. The plane (12-4) can slide within the waist-shaped groove (10-1) of the rotating bracket. Step S7: Position and clamp the grinding bushing Install the inner hole surface (13-1) of the grinding bushing onto the outer cylindrical surface (4-1) of the part to be ground. Apply grinding compound to the outer cylindrical surface (4-1) of the part to be ground. Slide the grinding bushing (13) up and down along the outer cylindrical surface (4-1) of the part to be ground. Adjust the tightening screw and the expanding screw of the grinding bushing on the grinding bushing to make the inner hole surface (13-1) of the grinding bushing fit with the outer cylindrical surface (4-1) of the part to be ground with a clearance fit. Press the two grinding bushing baffles (15) installed at the lower part of the connecting shaft (12) against the end face (13-6) of the grinding bushing, press the surface of the elastic pad of the grinding chuck against the outer cylindrical surface (13-2) of the grinding bushing, and tighten the tightening screw in the clamping threaded hole (14-5) of the two grinding chucks at the lower part of the connecting shaft (12); Press the two grinding bushing baffles (15) installed at the upper part of the connecting shaft (12) against the end face (13-6) of the grinding bushing, and position and clamp the grinding bushing (13) through the two sets of grinding bushing baffles (15) and grinding chucks (14) at 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) so that the axial positioning plane (12-3) is closely attached to the working plane (10-3) of the rotating bracket. Step S9: Grind the outer cylindrical surface of the part to be ground Apply grinding compound to the outer cylindrical surface (4-1) of the part to be ground, and rotate the hollow turntable (9) and the workpiece turntable (2); The hollow turntable (9) drives the grinding bushing (13) to rotate; The workpiece turntable (2) drives the part to be ground (4) to rotate; The electric push rod (3) drives the grinding bushing (13) to move up and down reciprocally. The rotation speed of the hollow turntable (9) and the rotation speed of the workpiece turntable (2) are relatively 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 bushing are inconsistent, and their rotation directions are opposite; The electric push rod (3) moves up and down reciprocally; During grinding, add grinding compound from the end of the U-shaped groove (13-7) of the grinding bushing. After grinding for a period of time, turn the grinding bushing (13) over and reinstall it, and continue to grind the outer cylindrical surface (4-1) of the part to be ground until grinding is completed.

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