Precision workpiece clamping and positioning device

Abstract

The invention discloses a precision workpiece clamping and positioning device, comprising a workpiece rotation driving device, a workpiece clamping device, and a controller. The workpiece rotation driving device comprises a workpiece rotating sun gear, a workpiece rotating sun gear input shaft, a workpiece rotating planetary gear, a workpiece rotating planetary gear output shaft, a servo motor, a fixed seat, and a cover plate. The upper end of the fixed seat is provided with a cover plate. The workpiece rotating planetary gear array is arranged on the circumference of the workpiece rotating sun gear and meshes with the workpiece rotating sun gear. The workpiece rotating sun gear is fixedly sleeved with the workpiece rotating sun gear input shaft. The upper end of the workpiece rotating sun gear input shaft is connected to the cover plate, and the lower end passes through the fixed seat and is connected to the servo motor. The workpiece rotating planetary gear is fixedly sleeved with the workpiece rotating planetary gear output shaft. The upper end of the workpiece rotating planetary gear output shaft passes through the cover plate and is connected to the workpiece clamping device. The invention has the advantages of novel structure, low manufacturing cost, high grinding efficiency, quick and convenient operation, and clamping without damaging the smoothness of the outer surface of the valve seat.

Description

Technical Field

[0001] The invention relates to the field of mechanical processing, in particular to a precision workpiece clamping and positioning device. Background Art

[0002] As is known to all, the existing air-locking valve achieves sealing by contacting the spherical sealing surface of the ball with the sealing spherical surface of the valve seat. The machining accuracy of the sealing spherical surface in the inner hole of the valve seat directly affects the sealing effect of the air-locking valve, so the grinding accuracy of the sealing spherical surface of the inner hole of the valve seat is very high. When grinding the sealing spherical surface of the valve seat, it is first necessary to use a workpiece clamping device to clamp the valve seat to fix the valve seat, and then grind. The outer surface of the inner hole of the valve seat is the sealing surface, which is used to be sleeved with the sleeve. The finish of the outer surface of the valve seat is also very high, otherwise it will affect the sealing effect.

[0003] At present, most people use manual labor in conjunction with a workpiece clamping device to manually grind the sealing spherical surface of the valve seat. A commonly used manual grinding device consists of a grinding ball, a connecting rod, and a grinding handle. The grinding ball is fixedly connected to one end of the connecting rod, and the grinding ball and the connecting rod are inserted into the inner hole of the valve seat from the opening above the valve seat, and the other end of the connecting rod passes through the opening below the valve seat and is detachably fixedly connected to the grinding handle; the workpiece clamping device can adopt: such as a workpiece concentric clamping device and clamping method disclosed in CN2019109709942, which is driven by forward and reverse lead screws and guide rods to make three clamping blocks move simultaneously and at the same distance to clamp the outer surface of the circular workpiece; such as an automatic clamping device disclosed in CN2019102911134, which automatically clamps the circular workpiece by driving the pressure claws on the clamping mechanism through a cylinder.

[0004] The operation method for grinding the sealing spherical surface of the valve seat is as follows: fix the valve seat through the workpiece clamping device, and then manually turn the grinding handle to drive the grinding ball to rotate, and grind the sealing spherical surface of the inner hole of the valve seat. After the grinding is completed, loosen the workpiece clamping device, take out the processed valve seat, remove the grinding handle, and take out the grinding ball from the opening above the valve seat.

[0005] The shortcomings of this structure are: first, the working method of manually grinding the inner hole sealing spherical surface, during the grinding process, the valve seat is fixed and cannot rotate relative to the grinding ball. Grinding is only achieved through the rotation of the grinding ball, which has high labor intensity and low grinding efficiency; second, the existing workpiece clamping device has a complex structure and needs to be driven by a driving device to clamp the workpiece, which has a high equipment procurement cost and cannot achieve rapid clamping and fixing of the valve seat, affecting the processing efficiency of the workpiece; third, the outer surface of the valve seat is a sealing surface, and the existing workpiece clamping device is prone to cause deformation of the outer side of the valve seat during the clamping process of the valve seat, which destroys the smoothness of the outer surface of the valve seat, resulting in poor sealing effect of the outer surface of the valve seat, affecting the use effect and service life of the valve seat. Summary of the invention

[0006] The purpose of the present invention is to solve the above-mentioned deficiencies of the prior art and to provide a precision workpiece clamping and positioning device with novel structure, low manufacturing cost, high grinding efficiency, quick and convenient operation, and the ability to clamp without damaging the smoothness of the outer surface of the valve seat.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A precision workpiece clamping and positioning device, characterized in that it includes a workpiece rotation driving device, a workpiece clamping device, and a controller, wherein the workpiece rotation driving device includes a workpiece rotation sun gear, a workpiece rotation sun gear input shaft, a workpiece rotation planetary gear, a workpiece rotation planetary gear output shaft, a servo motor, a fixed seat, and a cover plate, wherein a cover plate is provided at the upper end of the fixed seat, and the cover plate covers the fixed seat, and a workpiece rotation sun gear and a workpiece rotation planetary gear are provided between the cover plate and the fixed seat, the workpiece rotation planetary gear array is provided around the workpiece rotation sun gear and meshes with the workpiece rotation sun gear, the workpiece rotation sun gear is fixedly sleeved with the workpiece rotation sun gear input shaft, and the workpiece rotation The upper end of the rotating sun gear input shaft is fixedly connected to the cover plate via the second bearing, and the lower end is fixedly connected to the fixed seat via the first bearing, and passes through the fixed seat and is fixedly connected to the output shaft of the servo motor. The servo motor is controlled by a controller, and the workpiece rotating planetary gear is fixedly sleeved with the workpiece rotating planetary gear output shaft. The upper end of the workpiece rotating planetary gear output shaft is fixedly connected to the cover plate via the second bearing, and passes through the cover plate and is fixedly connected to the workpiece clamping device, and the lower end is fixedly connected to the fixed seat via the first bearing and passes through the fixed seat. The workpiece rotating sun gear and the workpiece rotating planetary gear are driven to rotate by the servo motor to drive the workpiece clamping device and the grinding tool to rotate in the opposite direction, thereby improving the grinding efficiency.

[0009] The workpiece rotation driving device described in the present invention also includes a fixing nut. The lower end of the workpiece rotating planetary gear output shaft passes through the fixing seat and is threadedly connected to the fixing nut. The upper end of the workpiece rotating planetary gear output shaft is provided with a shoulder, and the shoulder abuts against the inner ring of the second bearing. By setting the fixing nut and the shoulder, the workpiece rotating planetary gear output shaft is axially fixed to maintain the axial position.

[0010] The workpiece clamping device of the present invention adopts a wedge-shaped locking device, and a wedge-shaped block placement groove and a valve seat placement groove are provided on the output shaft of the workpiece rotating planetary wheel. The front groove wall and the rear groove wall of the wedge block placement groove are arranged in parallel and are respectively perpendicular to the bottom groove wall. The groove wall on one side of the wedge block placement groove is an inclined surface, and the other side is connected to the valve seat placement groove. The wedge-shaped locking device includes a wedge block, a fastening bolt, and a tension spring. The upper end face of the wedge block is arranged in parallel with the lower end face, and the front end face and the rear end face are arranged in parallel and are respectively perpendicular to the upper end face and the lower end face. The wedge block is straight, one end face of the wedge block is a guiding inclined surface, and the other end face is an arcuate surface. The wedge block is placed in the wedge block placement groove, and the guiding inclined surface of the wedge block has the same inclination as the inclined surface groove wall of the wedge block placement groove. The tension spring is sleeved on the fastening bolt, and the wedge block is threadedly connected to the output shaft of the workpiece rotating planetary gear through the fastening bolt and the tension spring. The workpiece to be processed is fixed in the valve seat placement groove through the wedge locking device, and the workpiece to be processed is clamped and positioned to prevent loosening. Using the wedge block to lock the workpiece to be processed will not cause deformation of the outer side of the valve seat.

[0011] The first bearing of the present invention adopts a first thrust ball bearing and a second thrust ball bearing. The workpiece rotating planetary gear output shaft and the workpiece rotating sun gear input shaft pass through the first thrust ball bearing and the second thrust ball bearing respectively to pass through the fixed seat. The shaft ring of the thrust ball bearing rotates with the shaft and fits with the rotating part. The thrust ball bearing is used to bear the axial load.

[0012] The beneficial effects of the present invention are as follows: the precision workpiece clamping and positioning device adopts a planetary gear structure, and a servo motor can drive several workpiece clamping devices to rotate and cooperate with the grinding tool for grinding, which greatly saves the equipment manufacturing cost and improves the grinding efficiency; the workpiece to be processed is positioned by the wedge locking device, and the structure is simple, which can not only realize the rapid and quick installation and fixation of the valve seat, but also ensure the concentricity of the grinding tool and the axial center hole of the valve seat to be processed, so that the grinding tool can achieve precise grinding and ensure the grinding accuracy requirements. At the same time, the use of wedge block locking will not cause deformation of the outer side of the valve seat, the outer surface of the valve seat has a high degree of finish and a good sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the precision workpiece clamping and positioning device of the present invention.

[0014] Figure 2 It is a schematic diagram of the overall structure of the precision workpiece clamping and positioning device of the present invention.

[0015] Figure 3 It is a schematic diagram of the overall structure of the precision workpiece clamping and positioning device of the present invention without the cover plate removed.

[0016] Figure 4 It is the front view of the precision workpiece clamping and positioning device of the present invention.

[0017] Figure 5 yes Figure 4 Middle AA section view.

[0018] Figure 6 It is a schematic diagram of the overall structure of the wedge-shaped locking device of the present invention.

[0019] Figure 7 It is a structural schematic diagram of the wedge-shaped locking device of the present invention being placed on the output shaft of the rotating planetary gear of the workpiece.

[0020] Figure 8 It is a schematic diagram of the structure of the valve seat placement groove and the wedge block placement groove of the present invention.

[0021] Fig. 9 It is a schematic diagram of the valve seat structure to be processed.

[0022] Fig.10 yes Fig. 9 Middle BB section view.

[0023] Fig.11 It is a schematic diagram of the overall structure of the present invention in actual use.

[0024] Fig.12 yes Fig.11 Middle DD section view.

[0025] Figure markings: pillar-1, top plate-2, bottom plate-3, guide shaft-4, planetary gear grinding device-5, tool rotating sun gear-501, tool rotating sun gear input shaft-502, tool rotating planetary gear-503, tool rotating planetary gear output shaft-504, first servo motor-505, first fixed seat-506, first cover plate-507, grinding tool-508, telescopic spring-509, fixed sleeve-510, tool fixing screw-511, first thrust ball bearing-514, second thrust ball bearing-515, first fixing nut-516, precision workpiece clamping and positioning device -6, workpiece rotating sun gear -601, workpiece rotating sun gear input shaft -602, workpiece rotating planetary gear -603, workpiece rotating planetary gear output shaft -604, second servo motor -605, second fixed seat -606, second cover plate -607, wedge block -608, fastening bolt -609, expansion spring -610, shaft shoulder -611, valve seat placement groove -612, wedge block placement groove -613, third thrust ball bearing -614, fourth thrust ball bearing -615, second fixing nut -616, cylinder -7, transmitting sensor -8, receiving sensor -9, valve seat -10. DETAILED DESCRIPTION

[0026] The present invention is described below in conjunction with the accompanying drawings and embodiments. The structure of the present invention is used in a high-precision inner hole sealing spherical grinding device in the following embodiment, and the following embodiment is an overall description of the actual use of the present invention. Figure 1-Figure 10 It is a view related to the structure of the present invention, Figure 11-Figure 12 The present invention is a schematic diagram of the overall structure of a high-precision inner hole sealing spherical grinding device.

[0027] As shown in the accompanying drawings, a high-precision inner hole sealing spherical grinding device includes a supporting frame, a guiding device, a planetary gear grinding device, a precision workpiece clamping and positioning device, a linear drive mechanism, and a controller. The linear drive mechanism and the planetary gear grinding device are controlled by the controller. The supporting frame includes a top plate 2, a bottom plate 3, and a pillar 1. The top plate 2 is located above the bottom plate 3. The top plate 2 and the bottom plate 3 are fixedly connected via the pillar 1. The fixed connection method can be bolts or welding. The linear drive mechanism is fixed on the top plate 2. The precision workpiece clamping and positioning device 6 is fixed on the bottom plate 3. A planetary gear grinding device 5 is provided between the top plate 2 and the bottom plate 3. The planetary gear grinding device 5 is slidably connected to the pillar 1 via a guiding device. The linear drive mechanism drives the planetary gear grinding device 5 to move up and down along the pillar 1. The workpiece is ground by driving the planetary gear grinding device downward to approach the precision workpiece clamping and positioning device under the action of the linear drive mechanism.

[0028] The planetary gear grinding device 5 includes a tool rotating sun gear 501, a tool rotating sun gear input shaft 502, a tool rotating planetary gear 503, a tool rotating planetary gear output shaft 504, a first servo motor 505, a first fixed seat 506, a first cover plate 507, and a grinding tool 508. The first fixed seat 506 is connected to the support 1 through a guide device. The upper end of the first fixed seat 506 is provided with a first cover plate 507. In the embodiment, the first cover plate is provided with a downward concave cavity. The first cover plate 507 covers the first fixed seat 506 and is connected to the first The fixing seat is fixedly connected, and a tool rotating sun gear 501 and a tool rotating planetary gear 503 are arranged between the first cover plate 507 and the first fixing seat 506. The tool rotating planetary gear 503 array is arranged around the tool rotating sun gear 501 and meshes with the tool rotating sun gear 501. The tool rotating sun gear 501 is fixedly sleeved with the tool rotating sun gear input shaft 502. In this embodiment, a keyway is provided on the shaft and the gear, and the key is embedded in the keyway for fixed sleeve connection. The lower end of the tool rotating sun gear input shaft 502 is connected through the first A bearing is fixedly connected to the first fixed seat 506, and the upper end is fixedly connected to the first cover plate 507 through the second bearing and passes through the first cover plate 507 to be fixedly connected to the output shaft of the first servo motor 505. The upper end of the first servo motor 505 is fixedly connected to the telescopic rod of the linear drive mechanism, and the first servo motor 505 is connected to the controller. The tool rotating planetary gear 503 is fixedly sleeved with the tool rotating planetary gear output shaft 504. The upper end of the tool rotating planetary gear output shaft 504 is fixedly connected to the first cover plate 507 through the second bearing and passes through the first cover plate, and the lower end is fixedly connected to the first fixed seat 506 through the first bearing and passes through the first fixed seat and is fixedly connected to the grinding tool 508. The workpiece to be processed is clamped by a precision workpiece clamping and positioning device. The planetary gear grinding device moves downward to approach the workpiece to be processed under the action of the linear drive mechanism. The tool rotating sun gear and the tool rotating planetary gear are driven to rotate by the first servo motor to drive the grinding tool to rotate to grind the workpiece to be processed. After grinding, the planetary gear grinding device moves up along the pillar under the action of the linear drive mechanism. In this embodiment, the linear drive mechanism uses a cylinder 7, an opening is provided on the top plate, the cylinder housing is fixed to the top plate by bolts, the piston rod of the cylinder passes through the top plate opening and is fixedly connected to the upper end of the first servo motor, and can also be driven by a hydraulic cylinder, an electric cylinder, etc.

[0029] The precision workpiece clamping and positioning device 6 comprises a workpiece rotating sun gear 601, a workpiece rotating sun gear input shaft 602, a workpiece rotating planetary gear 603, a workpiece rotating planetary gear output shaft 604, a second servo motor 605, a second fixed seat 606, a second cover plate 607, and a workpiece clamping device. The precision workpiece clamping and positioning device 6 is controlled by a controller, and the precision workpiece clamping and positioning device is connected to the pillar via a guide device.

[0030] The second fixed seat 606 is connected to the pillar 1 via a guide device. In this embodiment, the second fixed seat is provided with a concave cavity opening upward, and a second cover plate 607 is provided at the upper end of the second fixed seat 606. The second cover plate 607 covers the second fixed seat 606 and is fixedly connected to the second fixed seat. A workpiece rotating sun gear 601 and a workpiece rotating planetary gear 603 are provided between the second cover plate 607 and the second fixed seat 606. The workpiece rotating planetary gear 603 array is arranged around the workpiece rotating sun gear 601 and meshes with the workpiece rotating sun gear 601. The workpiece rotating sun gear 601 is fixedly sleeved with the workpiece rotating sun gear input shaft 602. In this embodiment, a keyway is provided on the shaft and the gear and the key is embedded in the keyway for fixed sleeve connection. The upper end of the workpiece rotating sun gear input shaft 602 is fixedly connected to the second cover plate 607 via a fourth bearing, and the lower end is fixedly connected to the third shaft The bearing is fixedly connected to the second fixed seat 606, and passes through the second fixed seat 606 and is fixedly connected to the output shaft of the second servo motor 605. The second servo motor 605 is fixedly connected to the base plate 3. The second servo motor 605 is controlled by the controller. The output shaft of the second servo motor rotates at the same speed and in the opposite direction as the output shaft of the first servo motor. The workpiece rotating planetary gear 604 is fixedly sleeved with the workpiece rotating planetary gear output shaft 604. The upper end of the workpiece rotating planetary gear output shaft 604 is fixedly connected to the second cover plate 607 via the fourth bearing, and passes through the second cover plate 607 and is fixedly connected to the workpiece clamping device. The lower end is fixedly connected to the second fixed seat via the third bearing and passes through the second fixed seat. The workpiece rotating sun gear and the workpiece rotating planetary gear are driven to rotate by the second servo motor, so as to drive the workpiece clamping device to rotate at the same speed and in the opposite direction as the grinding tool, thereby improving the grinding efficiency.

[0031] The planetary gear grinding device 5 also includes a first fixing nut 516. The upper end of the tool rotating planetary gear output shaft 504 passes through the first cover plate 507 and is threadedly connected to the first fixing nut. The first fixing nut can use a hexagonal nut or a round nut. The lower end of the tool rotating planetary gear output shaft 504 is provided with a first shoulder, which abuts against the inner ring of the first bearing. By setting the first fixing nut and the first shoulder, the tool rotating planetary gear output shaft is axially fixed to maintain the axial position. In this embodiment, the upper end of the tool rotating sun gear input shaft passes through the first cover plate and is also threadedly connected to the first fixing nut. The lower end is provided with a first shoulder, which abuts against the inner ring of the first bearing. By setting the first fixing nut and the first shoulder, the tool rotating sun gear input shaft is axially fixed.

[0032] The precision workpiece clamping and positioning device 6 also includes a second fixing nut 616. The lower end of the workpiece rotating planetary gear output shaft 604 passes through the second fixing seat 606 and is threadedly connected to the second fixing nut 616. The second fixing nut can use a hexagonal nut or a round nut. The upper end of the workpiece rotating planetary gear output shaft 604 is provided with a second shoulder, and the second shoulder abuts against the inner ring of the fourth bearing. By setting the second fixing nut and the second shoulder, the workpiece rotating planetary gear output shaft is axially fixed to maintain the axial position. In this embodiment, the lower end of the workpiece rotating sun gear input shaft passes through the second fixing seat and is also threadedly connected to the second fixing nut. The upper end is provided with a second shoulder, and the second shoulder abuts against the inner ring of the fourth bearing. By setting the second fixing nut and the second shoulder, the tool rotating sun gear input shaft is axially fixed.

[0033] The workpiece clamping device adopts a wedge-shaped locking device. The upper end of the workpiece rotating planetary gear output shaft is provided with a wedge block placement groove 613 and a valve seat placement groove 612. The front groove wall of the wedge block placement groove is parallel to the rear groove wall and is respectively perpendicular to the bottom groove wall. The groove wall on one side of the wedge block placement groove 613 is an inclined surface, and the other side is connected to the valve seat placement groove 612. The wedge-shaped locking device includes a wedge block 608, a fastening bolt 609, and a tension spring 610. The upper end face of the wedge block is parallel to the lower end face, and the front end face is parallel to the rear end face and is respectively mutually connected with the upper end face and the lower end face. Vertically, one end face of the wedge block 608 is a guiding bevel, and the other end face is an arcuate face. The wedge block is placed in the wedge block placement groove, and the guiding bevel of the wedge block has the same inclination as the bevel groove wall of the wedge block placement groove. The tension spring 610 is sleeved on the fastening bolt 609. The wedge block 608 is threadedly connected to the output shaft of the tool rotating planetary gear through the fastening bolt 609 and the tension spring 610. The workpiece to be processed is fixed in the valve seat placement groove through the wedge locking device, and the workpiece to be processed is clamped and positioned to prevent loosening. Using the wedge block to lock the workpiece to be processed will not cause deformation of the outer side of the valve seat.

[0034] The lower end of the first fixed seat 506 is fixedly connected with a transmitting sensor 8, and the upper end of the second cover plate 607 is fixedly connected with a receiving sensor 9. The transmitting sensor 8 is located directly above the receiving sensor 9. The transmitting sensor 8 and the receiving sensor 9 are respectively connected to the controller. The distance between the planetary gear grinding device and the precision workpiece clamping and positioning device is measured by the transmitting sensor 8 and the receiving sensor 9, and the concentricity of the grinding tool and the axial center hole of the workpiece to be processed is detected. In this embodiment, in order to prevent the equipment from colliding, when the grinding tool position reaches 10mm above the valve seat to be processed, the transmitting sensor and the receiving sensor cooperate to send a signal and feedback the position, and the cylinder slowly descends and stops at the valve seat grinding position.

[0035] A buffer device is provided between the grinding tool 508 and the tool rotating planetary gear output shaft 504, and the grinding tool is fixedly connected to the tool rotating planetary gear output shaft via the buffer device. The buffer device includes a fixing sleeve 510, a telescopic spring 509, a tool fixing screw 511, and a buffer baffle (not numbered in the figure). A groove opening downward is provided at the lower end of the tool rotating planetary gear output shaft, a boss (not numbered in the figure) is provided on the outer side of the fixing sleeve, the upper end of the fixing sleeve extends into the groove and is fixedly connected to the groove, the boss abuts against the lower end surface of the tool rotating planetary gear output shaft 504, the tool fixing screw 511 is movably inserted into the axis of the fixing sleeve, and the lower end of the tool fixing screw 511 is connected to the grinding tool 508. Threaded connection, the upper end of the grinding tool 508 is fixedly connected with a buffer baffle, the telescopic spring 509 is sleeved on the grinding tool and is located between the fixed sleeve boss and the buffer baffle, the upper end of the telescopic spring 509 is in contact with the fixed sleeve boss, and the lower end is in contact with the buffer baffle, and a guide keyway (not shown in the figure) is provided on the side wall of the inner hole of the fixed sleeve, and a guide key (not shown in the figure) is fixedly connected to one side of the tool fixing screw, and the grinding tool 508 moves up and down along the guide keyway via the guide key, and a buffer device is provided to enable the grinding tool to move up and down along the guide keyway under the action of the telescopic spring, so that the grinding tool is in buffer contact with the workpiece to be processed, and at the same time, the cooperation of the guide key and the guide keyway prevents the grinding tool from rotating circumferentially.

[0036] The guide device adopts a guide shaft, and four guide shafts 4 are provided. One end of the four guide shafts is fixedly connected to the four top corners of the bottom plate respectively, and the other end is fixedly connected to the four top corners of the top plate through the precision workpiece clamping and positioning device and the planetary gear grinding device. In this embodiment, the first fixed seat, the first cover plate, the second fixed seat, and the four top corners of the second cover plate are all provided with through holes for the guide shaft to pass through. After the lower end of the guide shaft is fixedly connected to the upper end of the bottom plate, the upper end passes through the second fixed seat, the second cover plate, the first fixed seat, and the first cover plate in sequence and is fixedly connected to the lower end of the top plate. The linear drive mechanism drives the planetary gear grinding device to move up and down along the guide shaft, and can also be achieved by using a guide rail. A guide rail is provided on the pillar, and sliders are provided on both sides of the first fixed plate of the planetary gear grinding device, so that the planetary gear grinding device moves up and down along the guide rail under the action of the linear drive mechanism.

[0037] The second bearing adopts a first thrust ball bearing 514 and a second thrust ball bearing 515. The tool rotating planetary gear output shaft 504 and the tool rotating sun gear input shaft 502 pass through the first cover plate 507 through the first thrust ball bearing 514 and the second thrust ball bearing 515 respectively. The upper end of the first thrust ball bearing is a first seat ring, and the lower end is a first shaft ring. The tool rotating planetary gear output shaft and the tool rotating sun gear input shaft are respectively fixedly connected to the first shaft ring, and the first shaft ring rotates with the shaft and fits the gear. The first seat ring is fixedly connected to the first cover plate. The upper end of the second thrust ball bearing is a second shaft ring, and the lower end is a second seat ring. The tool rotating planetary gear output shaft and the tool rotating sun gear input shaft are respectively fixedly connected to the second shaft ring, and the second shaft ring rotates with the shaft and fits the first fixing nut. The second seat ring is fixedly connected to the first cover plate. The third bearing adopts a third thrust ball bearing 614 and a fourth Thrust ball bearing 615, the workpiece rotating planetary gear output shaft 504 and the workpiece rotating sun gear input shaft 502 pass through the second fixed seat 606 through the third thrust ball bearing 614 and the fourth thrust ball bearing 615 respectively. The upper end of the third thrust ball bearing is the third shaft ring, and the lower end is the third seat ring. The workpiece rotating planetary gear output shaft and the workpiece rotating sun gear input shaft are respectively fixedly connected to the third shaft ring, and the third shaft ring rotates with the shaft and fits with the gear. The third seat ring is fixedly connected to the second fixed seat. The upper end of the fourth thrust ball bearing is the fourth seat ring, and the lower end is the fourth shaft ring. The workpiece rotating planetary gear output shaft and the workpiece rotating sun gear input shaft are respectively fixedly connected to the fourth shaft ring, and the fourth shaft ring rotates with the shaft and fits with the second fixing nut. The fourth seat ring is fixedly connected to the second fixed seat. The shaft ring of the thrust ball bearing rotates with the shaft and fits with the rotating part. By using the thrust ball bearing, it is used to bear the axial load.

[0038] In this embodiment, the sealing spherical surface of the inner hole of the valve seat needs to be processed. The processed parts are as follows: Fig.10 As shown in C in the middle.

[0039] The controller used in this embodiment is a PLC controller.

[0040] As shown in the attached drawings, six planetary gears are provided in this embodiment, and the number of planetary gears used can be determined according to actual needs. The tool rotating sun gear is the same size as the workpiece rotating sun gear, and the tool rotating planetary gear is the same size as the workpiece rotating planetary gear, ensuring that the grinding tool is located directly above the valve seat sealing spherical surface to be processed.

[0041] When the present invention is used, firstly, the valve seat to be processed is placed in the valve seat placement groove, and the wedge block is placed in the wedge block placement groove. The fixing bolts are tightened with a hexagonal wrench to fix the position of the wedge block and clamp the valve seat. The start button is pressed on the control panel, and the PLC controller is turned on. The piston rod of the cylinder moves downward, driving the planetary gear grinding device to move downward. The transmitting sensor and the receiving sensor cooperate to detect the distance between the planetary gear grinding device and the precision workpiece clamping and positioning device. When it is detected that the grinding tool reaches 10MM above the valve seat, the cylinder slowly descends, and the transmitting sensor and the receiving sensor cooperate to detect that the cylinder reaches the valve seat grinding position, and the program controls the cylinder piston rod to stop descending. After pressing the start button, the PLC controller drives the first servo motor and the second servo motor to rotate in the opposite direction at the same speed. The first servo motor and the second servo motor both rotate 10 times per second. The tool rotates the sun gear input shaft to drive the tool to rotate the sun gear clockwise, and drives the tool to rotate the planetary gear to drive the tool to rotate the planetary gear output shaft counterclockwise. The grinding tool rotates counterclockwise, and the workpiece rotates the sun gear input shaft to drive the workpiece to rotate the sun gear counterclockwise. Drive the workpiece to rotate the planetary gear to drive the workpiece to rotate the planetary gear output shaft clockwise, and the valve seat rotates clockwise. When the grinding tool reaches the valve seat grinding position, the grinding tool contacts the valve seat sealing sphere buffer under the action of the telescopic spring and rotates in the opposite direction for grinding. The grinding time is 20 minutes. After the grinding is completed, the cylinder drives the planetary gear grinding device to move upward and return to the initial position. At the same time, the first servo motor and the second servo motor stop driving to complete the processing. Use a hexagonal wrench to unscrew the fastening bolts on the wedge block, take out the processed valve seat, and then replace the valve seat to be processed. An emergency stop button is set on the control panel, and the equipment can be stopped by the emergency stop button during the processing.

[0042] The beneficial effects of the present invention are as follows: the precision workpiece clamping and positioning device adopts a planetary gear structure, and a servo motor can drive several workpiece clamping devices to rotate and cooperate with the grinding tool for grinding, which greatly saves the equipment manufacturing cost and improves the grinding efficiency; the workpiece to be processed is positioned by the wedge locking device, and the structure is simple, which can not only realize the rapid and quick installation and fixation of the valve seat, but also ensure the concentricity of the grinding tool and the axial center hole of the valve seat to be processed, so that the grinding tool can achieve precise grinding and ensure the grinding accuracy requirements. At the same time, the use of wedge block locking will not cause deformation of the outer side of the valve seat, the outer surface of the valve seat has a high degree of finish and a good sealing effect.

Claims

1. A precision workpiece clamping and positioning device, characterized in that: The invention comprises a workpiece rotation driving device, a workpiece clamping device and a controller, wherein the workpiece rotation driving device comprises a workpiece rotation sun gear, a workpiece rotation sun gear input shaft, a workpiece rotation planetary gear, a workpiece rotation planetary gear output shaft, a servo motor, a fixed seat and a cover plate, wherein a cover plate is provided at the upper end of the fixed seat, and the cover plate covers the fixed seat, and a workpiece rotation sun gear and a workpiece rotation planetary gear are provided between the cover plate and the fixed seat, the workpiece rotation planetary gear array is provided at the circumference of the workpiece rotation sun gear and meshes with the workpiece rotation sun gear, the workpiece rotation sun gear is fixedly sleeved with the workpiece rotation sun gear input shaft, the upper end of the workpiece rotation sun gear input shaft is fixedly connected to the cover plate via a second bearing, the lower end is fixedly connected to the fixed seat via a first bearing, and is fixedly connected to the output shaft of the servo motor through the fixed seat, the servo motor is controlled by the controller, the workpiece rotation planetary gear is fixedly sleeved with the workpiece rotation planetary gear output shaft, the upper end of the workpiece rotation planetary gear output shaft is fixedly connected to the cover plate via a second bearing, and is fixedly connected to the workpiece clamping device through the cover plate, and the lower end is fixedly connected to the fixed seat via a first bearing and is fixedly connected to the fixed seat; The workpiece clamping device adopts a wedge-shaped locking device, and the workpiece rotating planetary gear output shaft is provided with a wedge block placement groove and a valve seat placement groove, the front groove wall of the wedge block placement groove is arranged parallel to the rear groove wall and is respectively perpendicular to the bottom groove wall, and the groove wall on one side of the wedge block placement groove is an inclined surface, and the other side is connected with the valve seat placement groove, and the wedge locking device comprises a wedge block, a fastening bolt, and a tensioning spring. The upper end face of the wedge block is arranged parallel to the lower end face, and the front end face and the rear end face are arranged parallel to each other and are respectively perpendicular to the upper end face and the lower end face, and one end face of the wedge block is a guiding inclined surface, and the other end face is an arc surface. The wedge block is placed in the wedge block placement groove, and the guiding inclined surface of the wedge block has the same inclination as the inclined surface groove wall of the wedge block placement groove, and the tensioning spring is sleeved on the fastening bolt, and the wedge block is threadedly connected to the workpiece rotating planetary gear output shaft through the fastening bolt and the tensioning spring; The first bearing adopts a first thrust ball bearing and a second thrust ball bearing, and the workpiece rotating planetary gear output shaft and the workpiece rotating sun gear input shaft pass through the first thrust ball bearing and the second thrust ball bearing respectively and then pass through the fixing seat.

2. A precision workpiece clamping and positioning device according to claim 1, characterized in that: The workpiece rotation driving device also includes a fixing nut, the lower end of the workpiece rotation planetary gear output shaft passes through the fixing seat and is threadedly connected to the fixing nut, and the upper end of the workpiece rotation planetary gear output shaft is provided with a shaft shoulder, which abuts against the inner ring of the second bearing.

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