A ball valve core polishing and grinding device

Abstract

This invention discloses a ball valve core polishing and grinding device, belonging to the field of valve core grinding technology. The device includes a frame and a limiting and fixing device and a grinder mounted on the frame. The limiting and fixing device vertically clamps and drives the ball core to rotate. The grinder includes a U-shaped swing frame and two grinding heads at both ends of the swing frame, which can close together to abut against the surface of the ball core. Each grinding head includes a disc body with multiple independent grinding units evenly distributed in a ring around its circumference. Each grinding unit, while revolving with the disc body, drives the grinding block to rotate via a fixed drive ring and planetary gears. Each grinding unit is equipped with an independent pressure adjusting component and a floating support spring, which can independently adjust the clamping force according to the latitude position of the grinding block on the spherical surface, compensating for the difference in linear velocity between the equator and the poles. This invention can complete the full latitude grinding of the ball core in a single clamping operation, effectively improving the roundness accuracy and surface consistency of the ball core.

Description

Technical Field

[0001] This invention relates to the field of valve core polishing technology, specifically to a ball valve core polishing and polishing device and its usage method. Background Technology

[0002] Polishing the outer spherical surface of the ball valve core (hereinafter referred to as "ball core") is a crucial process for ensuring the valve's sealing performance. Currently, the dual-head oscillating polishing machine is the most widely used type of equipment for ball core polishing. Its basic structure is as follows: two polishing heads are mounted on a U-shaped oscillating frame, symmetrically arranged on both sides of the ball core. The ball core is clamped on the machine's main shaft and rotates at low speed around a vertical axis. The oscillating frame reciprocates under the drive of a motor, causing the polishing heads to perform enveloping polishing along the spherical surface. This solution has a mature structure and is easy to operate, making it a standard technical method in the industry.

[0003] However, this polishing method has an inherent physical contradiction: when the ball core rotates around its vertical axis, the linear velocity at different latitudes on the sphere varies significantly—the linear velocity is highest at the equator, gradually decreasing with increasing latitude, reaching zero at the extreme point. However, due to the integral structure of existing polishing heads, the clamping force applied to the sphere cannot be differentiated according to latitude and cannot remain constant throughout the polishing process. As a result, the equatorial region is over-cut due to high linear velocity and high clamping force, while the high-latitude region is under-polished due to low linear velocity and insufficient clamping force. The combined effect of these two factors leads to uneven cutting on the sphere core surface, making it difficult to guarantee roundness accuracy and causing annular differences on the surface.

[0004] To address the uneven grinding problem caused by the aforementioned differences in linear speed, the following solutions have been attempted in current production:

[0005] One method involves a two-stage clamping and reversing grinding process: after one grinding cycle, the ball core is removed from the machine, rotated by a certain angle (usually 90°), and re-clamped, moving the original high-latitude region (near the poles) to a position near the equator for further grinding. Through multiple reversals and clamping, all areas of the ball core surface are exposed to the equatorial region, where linear velocity is highest, for cutting. However, this method has significant drawbacks: firstly, the ball core requires repeated disassembly and repositioning, resulting in cumbersome operations, significantly increased auxiliary time, and severely restricting production efficiency; secondly, multiple clamping inevitably introduces repetitive positioning errors, making it difficult for the ball core's rotation center to precisely coincide with the machine spindle, leading to inconsistent cutting references for each grinding cycle, which worsens roundness accuracy. Furthermore, frequent clamping can easily cause scratches or pinching damage to the ball core surface.

[0006] Another approach involves operator-based adjustments based on experience: the operator adjusts the overall clamping force or oscillation parameters of the grinding head during the grinding process, either visually or by feel, attempting to mitigate localized overcutting or undercutting through human intervention. This method is highly dependent on the operator's skill level, suffers from poor quality consistency, and cannot physically eliminate the difference in cutting amount between the equator and the poles; essentially, it remains a remedial measure rather than a fundamental solution.

[0007] In addition, some solutions attempt to use contour grinding discs that match the shape of the ball core surface for large-area bonding and grinding, trying to improve uniformity by increasing the contact area. However, the contour grinding discs of this type of solution are integral rigid structures, and the clamping force of each area still cannot be adjusted independently. The contradiction between overcutting at the equator and undercutting at the poles has not been fundamentally resolved. Furthermore, the contour grinding discs need to be precisely matched with the size of the ball core, resulting in high redesign costs and poor flexibility.

[0008] Therefore, it is necessary to provide a ball core grinding device that can perform differentiated compression on different latitude regions of the sphere in a single clamping without repeated disassembly and assembly. Summary of the Invention

[0009] The purpose of this invention is to provide a ball valve core polishing and grinding device that can achieve compensation of clamping force at different latitudes of the sphere.

[0010] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is: a ball valve core polishing and grinding device, including a frame, and a limiting fixture and a grinder disposed on the frame; the limiting fixture can clamp the workpiece vertically and drive the workpiece to rotate around the vertical axis, and the grinder includes two grinding heads, left and right, which can be closed towards each other and abut against the workpiece, and can grind the workpiece by rotation;

[0011] The grinding head includes a grinding mechanism and a forward / backward drive mechanism arranged in a transverse direction. The grinding mechanism includes a grinding spindle, and grinding drive components and pressure regulating grinding disc components disposed at both ends of the grinding spindle.

[0012] The pressure-adjusting grinding disc assembly includes a fixed drive ring and a disc body. The disc body is fixedly mounted at the end of the grinding spindle facing the workpiece. A mounting groove with a cross-section in the shape of a "U" is arranged in a ring around the circumference of the disc body. Several grinding units are evenly distributed in a ring within the mounting groove, with the axis of each grinding unit pointing towards the center of the workpiece. Each grinding unit includes a rotating rod. The inner end of the rotating rod extends out of the mounting groove and is rotatably engaged with the mounting groove via a bushing. A grinding block is detachably connected to the inner end of the rotating rod. Two layers of mounting ribs extending circumferentially along the mounting groove are provided within the mounting groove. A planetary gear, forming a sliding engagement with the rotating rod, is sleeved on the middle section of the rotating rod. The planetary gear is mounted between the two layers of mounting ribs via a plane bearing to form axial positioning. Two baffles are also provided on the circumferential surface of the rotating rod between the mounting ribs and the groove wall. A floating support spring is provided between the two baffles and the mounting ribs. A pressure-adjusting component is also provided at the rear end of the rotating rod to apply a thrust along the axial direction of the rotating rod to its end.

[0013] The fixed drive ring is installed on the side of the disc away from the workpiece, and its outer circumference extends to the planetary gear. During the process of the planetary gear revolving around the grinding spindle, the fixed drive ring drives the planetary gear to rotate, thereby driving the rotating rod.

[0014] Preferably, the planetary gear is a bevel gear, and the fixed drive ring is a flat gear ring; or the planetary gear is a flat gear, and the fixed drive ring is a bevel gear ring; the planetary gear and the fixed drive ring are fully meshed.

[0015] Preferably, the outer peripheral surfaces of the planetary gear and the fixed drive ring are in contact with each other, and both outer peripheral surfaces are provided with a rubber friction layer.

[0016] Preferably, the voltage regulating component is an electromagnet fixed on the mounting groove, and the baffle opposite to the voltage regulating component is made of a permanent magnet; the thrust applied by the voltage regulating component to the rotating rod is the repulsive force between the electromagnet and the permanent magnet.

[0017] Preferably, the inner flange of the rotating rod is connected to an extension rod, and a grinding block is provided at the end of the extension rod away from the rotating rod. The grinding block is detachably connected to the extension rod by bolts.

[0018] Preferably, the grinder further includes a U-shaped swing frame mounted on the frame, and a swing drive mechanism for driving the swing frame to swing; the frame is provided with a swing center shaft extending in the front-rear direction, and the middle section of the swing frame is sleeved on the swing center shaft; the swing drive mechanism is mounted on the frame on one side of the swing frame.

[0019] Both the grinding mechanism and the forward / backward drive mechanism are mounted on the swing frame.

[0020] Preferably, the middle part of the swing frame is provided with a support plate parallel to the side of the U-shape of the swing frame, and the support plate is connected to the side of the U-shape of the swing frame by a guide rod;

[0021] The grinding drive assembly includes a mounting frame sleeved on the guide rod, a grinding motor is provided on the top of the mounting frame, and a gearbox is provided inside the mounting frame; the output end of the grinding motor is connected to the input end of the gearbox, and the output end of the gearbox is connected to the grinding spindle.

[0022] The forward and backward driving mechanism includes telescopic cylinders disposed on both ends of the swing frame, and the output end of the telescopic cylinder is connected to the side wall of the mounting frame.

[0023] Preferably, the fixed drive ring is sleeved on the outside of the grinding spindle via a bearing and is fixedly mounted on the swing frame via a connecting plate.

[0024] Preferably, the limiting and fixing device includes an upper clamping rod driven by an upper hydraulic cylinder and a lower clamping head assembly driven by a lower hydraulic cylinder. The lower clamping head assembly includes a sleeve mounted on the machine frame worktable and forming a rotatable engagement with the worktable, and a lifting rod passing through the sleeve and forming a slidable engagement with the sleeve. The lower end of the lifting rod is connected to the output end of the lower hydraulic cylinder through a rotary joint. A driven wheel is provided on the outer circumference of the lower end of the sleeve, and the driven wheel is connected to the driving wheel through a transmission belt. The driving wheel is driven by a position adjustment motor fixed on the machine frame.

[0025] Preferably, the frame is also provided with a spray pipe for spraying polishing fluid onto the surface of the workpiece.

[0026] The beneficial effects of this invention are mainly reflected in:

[0027] 1. It achieves precise compensation for the differential pressure at different latitudes of the sphere, fundamentally solving the problem of uneven cutting caused by differences in linear velocity.

[0028] This invention features multiple independent grinding units evenly distributed within an annular mounting groove on the periphery of the grinding disc. Each unit's rotating rod is equipped with an independent floating support spring and a pressure adjustment component. During grinding, each grinding block can independently adjust the clamping force applied to the spherical core surface based on its current spherical latitude position via the pressure adjustment component (such as the repulsive force between an electromagnet and a permanent magnet). When the grinding block is located in the equatorial region, the pressure adjustment component reduces the clamping force to avoid overcutting; when the grinding block is located in the polar region, the pressure adjustment component increases the clamping force to compensate for insufficient linear velocity. Compared to the shortcomings of existing integral grinding heads with constant pressure and no ability to adjust pressure in different zones, this invention achieves precise pressure control with "one pressure per location, real-time adaptation," effectively eliminating the difference in cutting amount between the equator and the poles, and significantly improving the roundness accuracy and surface quality consistency of the spherical core.

[0029] 2. Each grinding unit rotates independently while revolving around the sun, resulting in a compact transmission structure and high grinding efficiency.

[0030] This invention utilizes the meshing (or friction transmission) between a fixed drive ring and planetary gears to ensure that each grinding unit, while revolving around the entire grinding disc, simultaneously rotates its own axis, thereby driving the grinding blocks to rotate at high speed. This transmission method eliminates the need for a separate power source for each grinding unit; the rotation of the disc alone drives all grinding units to rotate synchronously. It features a highly integrated structure, high transmission efficiency, and excellent consistency in the rotational speed of each grinding block, ensuring uniform grinding results across all areas of the spherical surface.

[0031] 3. Grinding of all latitudes can be completed in a single clamping, significantly improving production efficiency and processing accuracy.

[0032] This invention utilizes the swing motion of a U-shaped swing frame to continuously swing the disc from the equator to the pole of the sphere's core. Combined with a limiting and fixing device for vertical clamping and rotational drive of the sphere's core, the grinding of the entire surface of the core can be completed in a single clamping operation. Compared to existing technologies that require repeated disassembly and reversal grinding, this invention avoids the problems of increased auxiliary time, accumulated errors from repeated positioning, and surface scratches caused by multiple clamping operations, effectively improving production efficiency and dimensional consistency. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the grinding head of the present invention;

[0035] Figure 3 for Figure 2 Enlarged view of section A in the middle;

[0036] Figure 4 for Figure 2 Top view;

[0037] Figure 5 This is a schematic diagram of the installation of the planetary gears and the fixed drive ring;

[0038] Figure 6 This is a schematic diagram of a preferred planetary gear structure.

[0039] Figure label:

[0040] 1-Frame, 2-Workpiece, 3-Grinding spindle, 4-Fixed drive ring, 5-Disc body, 6-Mounting slot, 7-Rotating rod, 8-Sleeve, 9-Grinding block, 10-Mounting ridge, 11-Planet gear, 12-Surface bearing, 13-Baffle plate, 14-Floating support spring, 15-Pressure adjusting component, 16-Rubber friction layer, 17-Extension rod, 18-Bolt, 19-Swing frame, 20-Swing center shaft, 21-Panel, 22- 23-Guide rod, 24-Mounting frame, 25-Grinding motor, 26-Gearbox, 27-Telescopic cylinder, 28-Bearing, 29-Connecting plate, 30-Upper hydraulic cylinder, 31-Upper clamping rod, 32-Lower hydraulic cylinder, 33-Worktable, 34-Sleeve, 35-Lifting rod, 36-Rotary joint, 37-Passive wheel, 38-Drive wheel, 39-Position adjustment motor, 40-Spray pipe, 41-Oscillating drive mechanism. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams and are only used to help understand the structural principles of the present invention. The specific shapes, dimensions, and installation details of the components in the drawings can be reasonably adjusted by those skilled in the art according to actual needs, and are not limited to the specific forms shown in the drawings.

[0042] It should be noted that in this description, the terms "lateral," "vertical," "longitudinal," "front," "rear," "left," and "right," indicating orientation or positional relationships, are based on the states shown in the accompanying drawings and are merely for descriptive convenience. They do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Furthermore, terms such as "install," "connect," "join," and "fix" should be interpreted broadly—they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0043] I. Overall Structure

[0044] like Figure 1 As shown, the present invention provides a ball valve core polishing and grinding device, which mainly includes a frame 1, and a limit fixer and a grinder disposed on the frame 1.

[0045] The limit holder is used to clamp the workpiece 2 (i.e., the ball core) vertically, while driving the workpiece 2 to rotate around its own vertical axis, so as to realize circumferential feed during grinding.

[0046] The grinder includes two grinding heads, left and right. These two grinding heads are symmetrically arranged and have the same structure. When they are closed in opposite directions, they can press against the surface of the workpiece 2 and grind the workpiece 2 by high-speed rotation.

[0047] The limiting and fixing device mainly consists of two parts: an upper clamping rod 30 driven by an upper hydraulic cylinder 29 and a lower chuck assembly driven by a lower hydraulic cylinder 31. The lower chuck assembly includes a sleeve 33 mounted on a worktable 32 and a lifting rod 34 passing through the sleeve 33. The sleeve 33 and the worktable 32 are in a rotating fit, while the lifting rod 34 and the sleeve 33 are in a sliding fit. The lower end of the lifting rod 34 is connected to the output end of the lower hydraulic cylinder 31 through a rotary joint 35, thus achieving both lifting and avoiding twisting of the hydraulic lines during rotation. A driven wheel 36 is provided on the outer circumference of the lower end of the sleeve 33, which is connected to a driving wheel 38 through a transmission belt 37. The driving wheel 38 is driven by a position adjustment motor 39 fixed on the frame 1, thereby causing the workpiece 2 to rotate around a vertical axis.

[0048] The frame 1 is also equipped with a spray pipe 40, which continuously sprays polishing fluid onto the surface of the workpiece 2 during the polishing process, serving to cool, lubricate, and remove chips.

[0049] II. Basic Components of a Grinding Head

[0050] like Figure 2 As shown, each grinding head mainly consists of two parts: a grinding mechanism arranged laterally and a forward / backward drive mechanism.

[0051] The grinding mechanism includes a grinding spindle 3, and grinding drive components and pressure-adjusting grinding disc components respectively disposed at both ends of the grinding spindle 3. The grinding spindle 3 extends horizontally, with the pressure-adjusting grinding disc component installed at the end facing the workpiece 2 (i.e., the inner end), and the grinding drive component connected at the end facing away from the workpiece 2 (i.e., the outer end), which is powered by a grinding motor 24.

[0052] The pressure-regulating grinding disc assembly is the core execution part of the entire grinding head, including the fixed drive ring 4 and the disc body 5.

[0053] The disc body 5 is fixedly installed on the inner end of the grinding spindle 3 and rotates together with the grinding spindle 3. On the side end face of the disc body 5 facing the workpiece 2, a mounting groove 6 with a cross-section of U-shape is opened along the circumference. The mounting groove 6 extends along the circumference of the disc body 5 to form a complete ring. Several grinding units are evenly distributed along the circumference in the mounting groove 6. The axis of these grinding units all points to the center of the ball of the workpiece 2. The purpose of this arrangement is to ensure that when each grinding block 9 is in contact with the surface of the ball core, the direction of force is along the normal direction of the spherical surface, so as to obtain the best contact effect and grinding efficiency.

[0054] The grinding drive assembly and the forward / backward drive mechanism are both mounted on the swing frame 19 and swing together with it. The swing frame 19 has a U-shaped structure, with its middle section fitted onto the swing center shaft 20 on the frame 1. It is driven by the swing drive mechanism 41 to swing back and forth around the swing center shaft 20, thereby realizing the covering movement of the grinding head from the equator of the ball core to the poles. The specific structure of the swing drive mechanism 41 varies. For example, it can drive a connecting rod through an eccentric wheel, and the connecting rod drives the swing frame 19. This structure is a conventional drive structure in the prior art and will not be described in detail in this invention. Of course, direct drive using pneumatic / electric push rods is also feasible. The middle part of the swing frame 19 is also provided with a support plate 21 parallel to the U-shaped side. The support plate 21 is connected to the side through a guide rod 22, which provides guidance for the lateral forward and backward movement of the grinding head.

[0055] In the grinding drive assembly, the mounting frame 23 is fitted over the guide rod 22 and can slide laterally along the guide rod 22. The grinding motor 24 is located on top of the mounting frame 23, and the gearbox 25 is located inside the mounting frame 23. The output end of the grinding motor 24 is connected to the input end of the gearbox 25, and the output end of the gearbox 25 is connected to the grinding spindle 3, thereby transmitting power to the pressure regulating grinding disc assembly.

[0056] The forward and backward drive mechanism consists of telescopic cylinders 26 installed on both ends of the swing frame 19. The output end of the telescopic cylinder 26 is connected to the side wall of the mounting frame 23. By extending and retracting the telescopic cylinder 26, the entire grinding head is pushed to close towards the workpiece 2 along the guide rod 22 or to detach away from the workpiece 2.

[0057] III. Specific Structure of the Grinding Unit

[0058] like Figure 3 As shown, the mounting groove 6 is provided with two layers of mounting ribs 10 extending in the circumferential direction, and a certain axial gap is reserved between the two layers of mounting ribs 10 for mounting planetary gears 11.

[0059] Each grinding unit includes a rotating rod 7, which is arranged radially along the disc body 5. The inner end of the rotating rod 7 (i.e. the end closest to the workpiece 2) extends out of the groove through a through hole in the wall of the mounting groove 6, and forms a rotational engagement with the mounting groove 6 through a bushing 8, allowing the rotating rod 7 to rotate freely around its own axis.

[0060] An extension rod 17 is installed at the inner end of the rotating rod 7 via a flange connection. The end of the extension rod 17 is detachably connected to the grinding block 9 via bolts 18. The grinding surface of the grinding block 9 is an arc-shaped surface that matches the curvature of the ball core surface. When the grinding block 9 is worn, it can be quickly replaced simply by loosening the bolts 18 without disassembling the entire grinding unit.

[0061] A planetary gear 11 is fitted in the middle section of the rotating rod 7. The planetary gear 11 and the rotating rod 7 form a sliding fit—that is, they are mutually constrained in the circumferential direction by a spline (or flat key) and can rotate synchronously; however, they are relatively free in the axial direction, and the planetary gear 11 does not restrict the axial movement of the rotating rod 7. The planetary gear 11 is mounted between two mounting ribs 10 by two flat bearings 12. The flat bearings 12 are located on both sides of the planetary gear 11 and abut against the end faces of the mounting ribs 10 on both sides, thereby achieving the axial positioning of the planetary gear 11—the planetary gear 11 can only rotate around its own axis and cannot move axially.

[0062] The rotating rod 7 is located on the circumferential surface between the mounting ridge 10 and the wall of the mounting groove 6. Two baffles 13 are also provided, located on either side of the planetary gear 11, and are fixedly sleeved on the rotating rod 7, moving axially together with it. A floating support spring 14 is provided between each baffle 13 and the adjacent mounting ridge 10. The floating support spring 14 is sleeved on the outer circumference of the rotating rod 7, with one end abutting the end face of the baffle 13 and the other end abutting the end face of the mounting ridge 10. The floating support spring 14 allows the rotating rod 7 a certain amount of axial floating margin, enabling each grinding block 9 to adaptively adjust its position according to the curvature of the spherical core when contacting it, ensuring reliable contact of all grinding blocks 9. Furthermore, it acts as a buffer during the closing process, absorbing impact force and preventing damage to the grinding block 9 or the surface of the spherical core caused by rigid collisions.

[0063] A pressure regulating component 15 is also provided at the rear end of the rotating rod 7 (i.e., the end away from the workpiece 2). The pressure regulating component 15 is fixed to the groove wall of the mounting groove 6 and is used to apply a thrust along the axial direction of the rotating rod 7 to the rear end face of the rotating rod 7. In this embodiment, the pressure regulating component 15 is an electromagnet, and the baffle 13 opposite it (i.e., the baffle located at the rear end of the rotating rod 7) is made of a permanent magnet (or has a permanent magnet embedded in it). When the electromagnet is energized, it generates a magnetic field, which interacts with the magnetic field of the permanent magnet to generate a repulsive force. The repulsive force acts along the axial direction of the rotating rod 7 at the rear end of the rotating rod 7, pushing the rotating rod 7 to move towards the workpiece 2, thereby increasing the pressing force of the grinding block 9 on the surface of the ball core. By adjusting the input current of the electromagnet, the magnitude of the repulsive force can be linearly adjusted, thereby achieving stepless adjustment of the pressing force of the grinding block 9.

[0064] It is worth emphasizing that each grinding unit is equipped with an independent pressure regulating component 15, and the current of each electromagnet can be controlled independently. Therefore, the clamping force of each grinding block 9 can be adjusted according to its latitude position on the sphere—a small current is output near the equator to weaken the pressure, and a large current is output near the poles to strengthen the pressure, thus achieving differentiated and precise control.

[0065] IV. Transmission Principle

[0066] like Figure 2 and Figure 5As shown, the fixed drive ring 4 is sleeved on the outside of the grinding spindle 3 via the bearing 27, and is fixedly mounted on the swing frame 19 via the connecting plate 28. In this way, when the grinding spindle 3 rotates freely within the bearing 27, the fixed drive ring 4 remains stationary and does not rotate with the disc body 5.

[0067] The outer periphery of the fixed drive ring 4 extends to the position of each planetary gear 11. When the disc 5 rotates with the grinding spindle 3, all grinding units revolve around the axis of the grinding spindle 3 along with the disc 5. During this process, each planetary gear 11 rolls along the outer periphery of the fixed drive ring 4.

[0068] There are several possible transmission methods between the planetary gear 11 and the fixed drive ring 4. As a preferred embodiment, the planetary gear 11 is a bevel gear, and the fixed drive ring 4 is a flat gear ring; the two mesh with each other, converting the revolution into the rotation of the planetary gear 11 through gear transmission. As another feasible embodiment, the planetary gear 11 can also be a flat gear, and the fixed drive ring 4 can correspondingly be a bevel gear ring, achieving meshing transmission in the same way. Furthermore, friction transmission can also be used—such as… Figure 6 As shown, the outer circumferential surfaces of the planetary gear 11 and the fixed drive ring 4 are in contact with each other, and both outer circumferential surfaces are provided with rubber friction layers 16. The planetary gear 11 is driven to rotate by friction. The advantage of this method is that the structure is simpler and it has a certain overload protection function.

[0069] Regardless of the transmission method used, the final result is the same: the planetary gear 11 gains rotational motion and transmits the rotation to the rotating rod 7 through the spline engagement with the rotating rod 7, thereby driving the grinding block 9 to rotate at high speed. In other words, with only the grinding spindle 3 as the power source, the dual motion of "all grinding blocks revolving around the ball core" and "each grinding block rotating around its own axis" is simultaneously achieved, demonstrating a highly integrated transmission structure.

[0070] V. Control Logic

[0071] During the actual grinding process, the swing frame 19 continuously swings back and forth under the drive of the swing drive mechanism 41, while the disc 5 continuously rotates under the drive of the grinding spindle 3. The control system needs to know the current latitude position of each grinding block 9 on the ball core in order to allocate the corresponding current value accordingly.

[0072] This requirement can be met by using angle sensors—an angle sensor (such as a rotary encoder) is installed at the swing center shaft 20 to detect the swing angle of the swing frame 19 in real time; at the same time, an encoder is installed on the grinding spindle 3 to detect the rotation angle of the disc 5 in real time. Combining these two angle signals, as well as the fixed installation position parameters of each grinding unit on the disc 5, the control unit can calculate the latitude position of each grinding block 9 on the spherical surface in real time.

[0073] Based on the preset pressure-latitude mapping relationship, the control unit independently outputs corresponding current values ​​to each electromagnet: when the grinding block 9 is near the equator, a smaller current is output, the repulsive force between the electromagnet and the permanent magnet is small, and the clamping force of the grinding block 9 on the ball core mainly comes from the basic elastic force of the floating support spring 14, resulting in lower pressure and preventing over-cutting in the equatorial region due to high linear velocity; as the grinding block 9 gradually moves towards the poles, the output current gradually increases, the repulsive force increases, and the clamping force of the grinding block 9 increases accordingly, compensating for insufficient cutting caused by low linear velocity in the pole regions. The entire adjustment process is continuous, dynamic, and real-time responsive.

[0074] Of course, the pressure on the floating support spring 14 can also be collected in real time by setting a pressure sensor at the mounting edge 10, and then the real-time pressure of the corresponding grinding block 9 can be calculated by combining various parameters, thereby flexibly controlling the output 15 of the pressure regulating component.

[0075] VI. Work Process

[0076] The working process of this device will be explained below in conjunction with the above structure.

[0077] Clamping stage: Place the ball core to be polished on the upper end of the lifting rod 34 of the lower chuck assembly, start the lower hydraulic cylinder 31 to drive the lifting rod 34 to rise to the predetermined height, and then start the upper hydraulic cylinder 29 to drive the upper clamping rod 30 to descend, pressing the ball core from above to complete the vertical clamping.

[0078] Closing Phase: The telescopic cylinders 26 of the two grinding heads are activated. The cylinders extend, pushing the mounting frame 23 to slide along the guide rod 22 towards the workpiece 2. The disc 5 gradually approaches the ball core, and each grinding block 9 adaptively conforms to the surface of the ball core under the action of the floating support spring 14. Because each grinding unit floats independently, even if there are slight roundness deviations or installation errors on the surface of the ball core, each grinding block 9 can find its own conforming position, preventing any individual grinding blocks from being suspended in mid-air.

[0079] Grinding stage: The orientation adjustment motor 39 is started, which drives the sleeve 33 to rotate through the drive wheel 38, transmission belt 37, and driven wheel 36, thereby driving the lifting rod 34 and the ball core to rotate at low speed around the vertical axis. At the same time, the two grinding motors 24 on the left and right are started, which drive the grinding spindle 3 to rotate after being changed by the gearbox 25. The disc 5 rotates accordingly, and each grinding block 9 rotates on its own axis while revolving around the central axis, forming a grinding effect on the surface of the ball core.

[0080] During the polishing process, the swing drive mechanism 41 continuously drives the swing frame 19 to swing back and forth around the swing center axis 20, causing the disc 5 to gradually swing from the equatorial region to the pole region and then back to the equatorial region, thus achieving full-latitude coverage polishing of the ball core. At the same time, the control unit calculates the latitudinal position of each polishing block 9 in real time based on the signal fed back by the angle sensor, and adjusts the current of each electromagnet to achieve differentiated clamping.

[0081] After grinding is completed, all drive motors stop, telescopic cylinder 26 retracts, and mounting frame 23 is pulled back. The left and right grinding heads are disengaged from the ball core, and upper clamping rod 30 is lifted to remove the ground ball core.

[0082] VII. Changeover Operation

[0083] When grinding ball cores of different specifications, the lower hydraulic cylinder 31 can drive the lifting rod 34 to rise and fall, adjusting the vertical position of the ball cores so that the center of the ball cores of different radii is aligned with the center of the ball core in the disc 5. This is a way to compensate for changes in the radius of the ball cores by adjusting the longitudinal position, and the operation is simple. If the ball core specifications change significantly, causing the curvature to be mismatched, simply loosen the bolt 18, replace the corresponding grinding block 9, and replace the longer extension rod 17. There is no need to disassemble the entire grinding unit, resulting in high changeover efficiency.

[0084] The structure, size, quantity, and arrangement of the components described in the above specific embodiments are all exemplary. Those skilled in the art can make reasonable adjustments and changes to these specific details without departing from the core concept of the present invention, and such adjustments and changes should be covered within the protection scope of the present invention.

Claims

1. A ball valve core polishing and grinding device, comprising a frame (1), and a limiting fixture and a grinder disposed on the frame (1); the limiting fixture is capable of clamping a workpiece (2) vertically and driving the workpiece (2) to rotate around a vertical axis, the grinder comprising two grinding heads, the two grinding heads being able to close together and abut against the workpiece (2), and being able to grind the workpiece (2) by rotation; Its features are: The grinding head includes a grinding mechanism and a forward and backward drive mechanism arranged in a transverse direction. The grinding mechanism includes a grinding spindle (3), and grinding drive components and pressure regulating grinding disc components arranged at both ends of the grinding spindle (3). The pressure-adjusting grinding disc assembly includes a fixed drive ring (4) and a disc body (5). The disc body (5) is fixedly mounted at one end of the grinding spindle (3) facing the workpiece (2). The disc body (5) has a mounting groove (6) with a cross-section in the shape of a U-shape arranged in a ring around its periphery. Several grinding units are evenly distributed in a ring within the mounting groove (6), and the axis of the grinding unit points to the center of the ball of the workpiece (2). The grinding unit includes a rotating rod (7). The inner end of the rotating rod (7) extends out of the mounting groove (6) and forms a rotational fit with the mounting groove (6) through a bushing (8). The inner end of the rotating rod (7) is detachably connected to a grinding block (9). Two layers of edge mounting blocks are arranged within the mounting groove (6). The mounting groove (6) has a circumferentially extending mounting rib (10). The middle section of the rotating rod (7) is fitted with a planetary gear (11) that forms a sliding fit with the rotating rod (7). The planetary gear (11) is mounted between the two mounting ribs (10) through a plane bearing (12) to form an axial positioning. The rotating rod (7) is also provided with two baffles (13) on its circumferential surface between the mounting rib (10) and the groove wall of the mounting groove (6). A floating support spring (14) is provided between the two baffles (13) and the mounting rib (10). The rear end of the rotating rod (7) is also provided with a pressure adjusting component (15) for applying a thrust along the axial direction of the rotating rod (7) to the end of the rotating rod (7). The fixed drive ring (4) is installed on the side of the disc body (5) away from the workpiece (2), and its outer circumference extends to the planetary gear (11). During the process of the planetary gear (11) revolving around the grinding spindle (3), the fixed drive ring (4) drives the planetary gear (11) to rotate so as to drive the rotating rod (7).

2. The ball valve core polishing and grinding device according to claim 1, characterized in that: The planetary gear (11) is a bevel gear, and the fixed drive ring (4) is a flat gear ring; or the planetary gear (11) is a flat gear, and the fixed drive ring (4) is a bevel gear ring; the planetary gear (11) and the fixed drive ring (4) mesh with each other.

3. The ball valve core polishing and grinding device according to claim 1, characterized in that: The outer peripheral surfaces of the planetary gear (11) and the fixed drive ring (4) are in contact with each other, and both outer peripheral surfaces are provided with a rubber friction layer (16).

4. The ball valve core polishing and grinding device according to claim 2, characterized in that: The voltage regulating component (15) is an electromagnet fixed on the mounting groove (6), and the baffle (13) opposite to the voltage regulating component (15) is made of a permanent magnet; the thrust applied by the voltage regulating component (15) to the rotating rod (7) is the repulsive force between the electromagnet and the permanent magnet.

5. The ball valve core polishing and grinding device according to claim 4, characterized in that: The inner flange of the rotating rod (7) is connected to an extension rod (17). A grinding block (9) is provided at the end of the extension rod (17) away from the rotating rod (7). The grinding block (9) is detachably connected to the extension rod (17) by bolts (18).

6. The ball valve core polishing and grinding device according to claim 5, characterized in that: The grinder also includes a U-shaped swing frame (19) mounted on the frame (1) and a swing drive mechanism (41) for driving the swing frame (19) to swing; the frame (1) is provided with a swing center shaft (20) extending in the front-back direction, and the middle section of the swing frame (19) is sleeved on the swing center shaft (20); the swing drive mechanism is mounted on the frame (1) on one side of the swing frame (19); Both the grinding mechanism and the forward / backward drive mechanism are mounted on the swing frame (19).

7. The ball valve core polishing and grinding device according to claim 6, characterized in that: The swing frame (19) has a support plate (21) in the middle that is parallel to the side of the U-shape of the swing frame (19), and the support plate (21) is connected to the side of the U-shape of the swing frame (19) by a guide rod (22). The grinding drive assembly includes a mounting frame (23) sleeved outside the guide rod (22), a grinding motor (24) is provided on the top of the mounting frame (23), and a gearbox (25) is provided inside the mounting frame (23); the output end of the grinding motor (24) is connected to the input end of the gearbox (25), and the output end of the gearbox (25) is connected to the grinding spindle (3); The forward and backward driving mechanism includes telescopic cylinders (26) disposed on both ends of the swing frame (19), and the output end of the telescopic cylinders (26) is connected to the side wall of the mounting frame (23).

8. The ball valve core polishing and grinding device according to claim 7, characterized in that: The fixed drive ring (4) is sleeved on the outside of the grinding spindle (3) through the bearing (27) and fixedly installed on the swing frame (19) through the connecting plate (28).

9. The ball valve core polishing and grinding device according to claim 1, characterized in that: The limiting and fixing device includes an upper clamping rod (30) driven by an upper hydraulic cylinder (29) and a lower clamping head assembly driven by a lower hydraulic cylinder (31). The lower clamping head assembly includes a sleeve (33) mounted on the worktable (32) of the frame (1) and rotating with the worktable (32), and a lifting rod (34) passing through the sleeve (33) and slidingly engaging with the sleeve (33). The lower end of the lifting rod (34) is connected to the output end of the lower hydraulic cylinder (31) through a rotary joint (35). A driven wheel (36) is provided on the outer circumference of the lower end of the sleeve (33), and the driven wheel (36) is connected to the driving wheel (38) through a transmission belt (37). The driving wheel (38) is driven by an orientation adjustment motor (39) fixed on the frame (1).

10. The ball valve core polishing and grinding device according to claim 1, characterized in that: The frame (1) is also equipped with a spray pipe (40) for spraying polishing fluid onto the surface of the workpiece (2).

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