AGV vehicle-mounted three-claw synchronous pneumatic self-centering workpiece positioning tool

Abstract

This invention relates to the field of workpiece clamping technology and discloses an AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture, including a centering mechanism. The centering mechanism includes a rotary cylinder, and a guide rail is provided on the outer side of the rotary cylinder. Three guide rails are provided and are evenly distributed circumferentially around the rotary cylinder. The output end of the rotary cylinder is drivenly connected to a connecting seat, and a crank is hinged to the upper surface of the connecting seat. A reciprocating block is hinged to the outer end of the crank. This AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture can effectively solve the problem in the prior art where there is an eccentric error during the placement of silicon ring workpieces before transfer. Most common positioning mechanisms use gears or linkage rods for transmission, which makes it difficult to achieve strictly synchronized radial movement of multiple jaws, resulting in insufficient centering accuracy of the silicon ring, causing positioning deviations, and affecting docking with subsequent workstations.

Description

Technical Field

[0001] This invention relates to the field of workpiece clamping technology, specifically to an AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture. Background Technology

[0002] In the photovoltaic and semiconductor manufacturing industries, silicon rings are important auxiliary workpieces that need to be frequently transferred between multiple processes. In the silicon ring workpiece processing and transfer production process, AGVs are often used to realize the automated transfer and docking of workpieces with workstations, and the positioning accuracy of the workpiece transfer and processing process directly determines the product processing quality.

[0003] In existing technologies, there will be eccentricity errors during the placement of silicon ring workpieces before transfer. Most common positioning mechanisms use gears or linkage rods for transmission, which makes it difficult to achieve strictly synchronized radial movement of multiple claws. This results in insufficient centering accuracy of the silicon ring, causing positioning deviations and affecting docking with subsequent workstations. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides an AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture. This fixture effectively solves the problem of eccentricity errors during the placement of silicon ring workpieces before transfer, which is common in existing technologies. Furthermore, most common positioning mechanisms use gears or linkage rods for transmission, making it difficult to achieve strictly synchronized radial movement of multiple jaws. This results in insufficient centering accuracy of the silicon ring, causing positioning deviations and affecting docking with subsequent workstations.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture, comprising: A centering mechanism includes a rotary cylinder, with guide rails arranged on the outer side of the rotary cylinder. Three guide rails are arranged in a circle evenly distributed around the rotary cylinder. A connecting seat is driven to the output end of the rotary cylinder. A crank is hinged to the upper surface of the connecting seat. A reciprocating block is hinged to the outer end of the crank. The reciprocating block is slidably connected to the upper surface of the guide rail. A gripper is fixedly connected to the upper surface of the reciprocating block. A connecting rod is axially slidably connected to the inside of the gripper. A positioning block is fixedly connected to the top end of the connecting rod. The base is fixed relative to the rotary cylinder and guide rail and can be installed on the AGV. The base has a groove inside for accommodating the sliding of the gripper. The base is connected to an annular plate through a shock absorber inside it. The annular plate is located above the base and is used to place an external silicon ring. The annular plate has a limiting slot inside for accommodating the sliding of the positioning block. The outer surface of the positioning block is provided with a limiting block that fits against the inner wall of the limiting slot. Each positioning block has two sets of limiting blocks on its outer surface, upper and lower, for fitting against the limiting slot to slide up and down synchronously with the annular plate.

[0006] Furthermore, a positioning pin is fixedly connected to the middle of the base, the positioning pin extends upward and passes through the hollow area in the middle of the annular plate, and the free end of the positioning pin protrudes upward from the annular plate.

[0007] Furthermore, the shock absorber includes a guide rod that slides vertically inside the base. The top end of the guide rod is fixedly connected to the lower surface of the annular plate, and the bottom end of the guide rod passes through the base and is fixedly connected to a baffle plate. A spring connected to the outer surface of the base is sleeved on the outer circumference of the guide rod.

[0008] Furthermore, each of the guide rods has two springs fitted on its outer circumferential surface, and the two springs are symmetrically distributed on the upper and lower sides of the base.

[0009] Furthermore, a semi-circular block is embedded on the outer surface of the positioning block, and a lower pressure plate parallel to the upper surface of the silicon ring is provided above the positioning block. The positioning block is equipped with a linkage component through a movable cavity opened inside it.

[0010] Furthermore, the side of the semicircular block away from the annular plate adopts an arc surface design that fits into the inner wall surface of the silicon ring, while the side of the semicircular block close to the annular plate is a flat surface.

[0011] Furthermore, the linkage includes a horizontal rod that slides horizontally within the movable cavity. The outer end of the horizontal rod extends to the outside of the positioning block and is fixedly connected to the inner surface of the semicircular block near the annular plate. A compression spring is sleeved on the outer circumferential surface of the horizontal rod.

[0012] Furthermore, a vertical rod that slides perpendicularly to the interior of the movable cavity is fixedly connected to the lower surface of the lower pressure plate. A tension spring connected to the bottom end of the vertical rod and the bottom end of the inner wall of the movable cavity is provided. A rotating rod is hinged to the middle of the vertical rod. A shaft that slides horizontally to the interior of the movable cavity is fixedly connected to the outer end of the rotating rod. An abutment plate that fits against the outer end of the rotating rod is fixedly connected to the inner end of the horizontal rod.

[0013] Furthermore, the spring constant of the compression spring is greater than that of the tension spring, and the lower surface of the lower pressure plate is covered with a flexible layer. The axis of the locating pin coincides with the axis of the connecting seat. When the lower pressure plate is at its lowest point within its stroke range, the lower surface of the lower pressure plate is lower than the upper surface of the semicircular block. For silicon rings with a thickness less than the height of the semicircular block, the lower pressure plate can also tightly fit the silicon ring against the upper surface of the annular plate. The limiting groove and the sliding groove coincide in the vertical direction.

[0014] The technical solution provided by this invention has the following advantages compared with the prior art: 1. This invention features a centering mechanism with a rotary cylinder and crank. Three grippers and positioning blocks enable uniform, synchronous radial extension and retraction, working in conjunction with a coaxial reference positioning pin to construct a three-point uniform centering system. This effectively compensates for workpiece eccentricity errors during production and loading, while also offsetting displacement errors caused by the AGV's start-stop operation, repetitive positioning errors during robotic arm loading and unloading, and correcting cumulative positioning deviations caused by inconsistent coordinate systems in multi-device collaborative operations. It achieves adaptive correction of multiple errors at the structural level, ensuring the coaxiality and positioning accuracy of the silicon ring workpiece after clamping, meeting the positioning requirements of precision machining in semiconductors and photovoltaics.

[0015] 2. Existing tooling lacks a dedicated shock-absorbing and protective structure. The AGV's bumpy transport and start-stop inertia easily cause relative sliding and collision damage between the workpiece and the tooling, severely impacting product yield. This invention incorporates symmetrical shock-absorbing components between the base and the annular plate. The symmetrically distributed double-spring structure on both sides of the base simultaneously buffers the impact energy generated by the AGV's vertical movement, achieving omnidirectional shock absorption. Simultaneously, the positioning block, through two sets of upper and lower limit blocks, forms a follow-up engagement with the limit slots of the annular plate. The structural design of the limit slots and the sliding grooves perpendicularly aligns ensures that the centering mechanism moves synchronously with the annular plate during shock absorption, preventing relative displacement and frictional shaking between the workpiece and the tooling. Throughout the transport process, a dual fixed state of radial elastic clamping and axial flexible compression is maintained, effectively resisting lateral forces generated by workpiece turning and emergency braking. This solves the problems of workpiece loosening, shifting, falling off, and collision damage during transport, greatly improving the stability of transport operations and product qualification rate.

[0016] 3. This invention incorporates an abutment plate, a rotating rod, a vertical rod, a lower pressure plate, and a tension spring inside the positioning block, which automatically link with the radial centering mechanism. When the semicircular block is obstructed by the inner wall of the silicon ring and retracts relative to the positioning block, the abutment plate moves inward, releasing the thrust on the rotating rod. The tension spring then drives the lower pressure plate downward and tightly adheres to the upper surface of the silicon ring, pressing the silicon ring firmly against the annular plate and locking the axial vertical distance between the silicon ring and the annular plate, ensuring that the silicon ring has no floating gap or space for movement in the axial direction. During transport, the lower pressure plate remains pressed under the continuous action of the tension spring, effectively preventing axial movement of the silicon ring.

[0017] 4. In this invention, the lower pressure plate provides axial clamping force via a tension spring, and the stroke range of the lower pressure plate covers various specifications of silicon rings, from thin to thick. For thin silicon rings with a thickness less than the height of a semicircular block, the lower pressure plate can descend to its lowest point of travel, still tightly pressing the silicon ring against the upper surface of the ring plate. For thicker silicon rings, the lower pressure plate stops descending after contacting the upper surface of the silicon ring, and the tension spring is stretched to the corresponding length, providing clamping force matching the thickness of the silicon ring. Simultaneously, because the elastic coefficient of the compression spring is greater than that of the tension spring, and the elastic clamping force of the compression spring is always greater than the elastic tension of the tension spring, sufficient radial clamping force and moderate axial clamping force are ensured during clamping, preventing the silicon ring from being crushed due to excessive clamping force. Therefore, this fixture can adapt to silicon rings of various thicknesses, improving the versatility of the fixture and reducing changeover costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0019] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the separation structure of the centering mechanism, base, and annular plate in an embodiment of the present invention; Figure 3 This is a schematic diagram of the centering mechanism according to an embodiment of the present invention; Figure 4 This is a cross-sectional structural diagram of the base, annular plate, and shock absorber in an embodiment of the present invention; Figure 5 This is an embodiment of the present invention. Figure 4 A magnified structural diagram of part A in the middle; Figure 6 This is a schematic diagram of the separated structure of the connecting rod, positioning block, and gripper in an embodiment of the present invention; Figure 7 This is a cross-sectional structural diagram of the positioning block, semi-circular block, pressing block, and linkage component according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of the semicircular block, the lower pressure block, and the linkage component in an embodiment of the present invention.

[0020] The labels in the diagram represent: 1. Centering mechanism; 11. Rotary cylinder; 12. Guide rail; 13. Connecting seat; 14. Crank; 15. Reciprocating block; 16. Gripper; 161. Connecting rod; 2. Positioning block; 21. Limiting block; 22. Semicircular block; 23. Lower pressure plate; 24. Movable cavity; 25. Linkage component; 251. Horizontal rod; 252. Compression spring; 253. Vertical rod; 254. Tension spring; 255. Rotating rod; 256. Shaft; 257. Abutment plate; 3. Base; 31. Slide groove; 32. Shock absorber; 321. Guide rod; 322. Baffle plate; 323. Spring; 33. Annular plate; 331. Limiting groove; 4. Positioning pin. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] The present invention will be further described below with reference to embodiments. Example

[0023] Please see Figures 1-8 This invention provides a technical solution: an AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture, comprising: Centering mechanism 1 includes a rotary cylinder 11. A guide rail 12 is provided on the outer side of the rotary cylinder 11. There are three guide rails 12, which are evenly distributed in a circle around the rotary cylinder 11. The output end of the rotary cylinder 11 is connected to a connecting seat 13. A crank 14 is hinged to the upper surface of the connecting seat 13. A reciprocating block 15 is hinged to the outer end of the crank 14. The reciprocating block 15 is slidably connected to the upper surface of the guide rail 12. A gripper 16 is fixedly connected to the upper surface of the reciprocating block 15. A connecting rod 161 is axially slidably connected inside the gripper 16. A positioning block 2 is fixedly connected to the top end of the connecting rod 161. The base 3 has a groove 31 inside for accommodating the sliding of the gripper 16. The base 3 is connected to an annular plate 33 through a shock absorber 32 inside it. The annular plate 33 is located above the base 3 and is used to place an external silicon ring. The annular plate 33 has a limiting groove 331 inside for accommodating the sliding of the positioning block 2. The outer surface of the positioning block 2 is provided with a limiting block 21 that fits against the inner wall of the limiting groove 331. Each positioning block 2 has two sets of limiting blocks 21 on its outer surface, which fit against the limiting groove 331 to slide up and down synchronously with the annular plate 33.

[0024] A positioning pin 4 is fixedly connected to the middle of the base 3. The positioning pin 4 extends upward and passes through the hollow area in the middle of the annular plate 33, and the free end of the positioning pin 4 protrudes upward from the annular plate 33.

[0025] The shock absorber 32 includes a guide rod 321 that slides vertically inside the base 3. The top end of the guide rod 321 is fixedly connected to the lower surface of the annular plate 33. The bottom end of the guide rod 321 passes through the base 3 and is fixedly connected to a baffle 322. A spring 323 connected to the outer surface of the base 3 is sleeved on the outer circumference of the guide rod 321.

[0026] Two springs 323 are fitted on the outer circumference of each guide rod 321, and the two springs 323 are symmetrically distributed on the upper and lower sides of the base 3.

[0027] A semi-circular block 22 is embedded on the outer surface of the positioning block 2, and a lower pressure plate 23 parallel to the upper surface of the silicon ring is provided above the positioning block 2. The positioning block 2 is provided with a linkage 25 through the movable cavity 24 opened inside it.

[0028] The side of the semicircular block 22 away from the annular plate 33 is designed with an arc surface that fits into the inner wall surface of the silicon ring, while the side of the semicircular block 22 close to the annular plate 33 is a flat surface.

[0029] The linkage 25 includes a horizontal rod 251 that slides horizontally inside the movable cavity 24. The outer end of the horizontal rod 251 extends to the outside of the positioning block 2 and is fixedly connected to the inner surface of the semicircular block 22 near the annular plate 33. A compression spring 252 is sleeved on the outer circumference of the horizontal rod 251.

[0030] A vertical rod 253 that slides vertically inside the movable cavity 24 is fixedly connected to the lower surface of the pressure plate 23. A tension spring 254 connected to the bottom of the inner wall of the movable cavity 24 is provided at the bottom end of the vertical rod 253. A rotating rod 255 is hinged to the middle of the vertical rod 253. A shaft 256 that slides horizontally inside the movable cavity 24 is fixedly connected to the outer end of the rotating rod 255. An abutment plate 257 that fits against the outer end of the rotating rod 255 is fixedly connected to the inner end of the horizontal rod 251.

[0031] The spring constant of compression spring 252 is greater than that of tension spring 254. The lower surface of the lower pressure plate 23 is covered with a flexible layer, and the axis of the positioning pin 4 coincides with the axis of the connecting seat 13. When the lower pressure plate 23 is at its lowest point within its stroke range, the lower surface of the lower pressure plate 23 is lower than the upper surface of the semicircular block 22. For silicon rings with a thickness less than the height of the semicircular block 22, the lower pressure plate 23 can also tightly fit the silicon ring against the upper surface of the annular plate 33. The limiting groove 331 and the sliding groove 31 coincide in the vertical direction.

[0032] In the initial state, the centering mechanism 1 is in the retracted state. The rotary cylinder 11 is not vented and its output end is in the initial position. The connecting seat 13, which is connected to the output end of the rotary cylinder 11, drives the crank 14 to the retracted position. Since the inner end of the crank 14 is hinged to the upper surface of the connecting seat 13 and the outer end of the crank 14 is hinged to the reciprocating block 15, when the connecting seat 13 is in the initial angle, the outer end of the crank 14 is pulled towards the direction close to the central axis of the rotary cylinder 11, thereby driving the reciprocating block 15 to slide along the upper surface of the guide rail 12 towards the side close to the central axis of the base 3.

[0033] Since there are three guide rails 12, and the three guide rails 12 are evenly distributed in a circle around the rotary cylinder 11, the three reciprocating blocks 15 retract synchronously towards the center along the three guide rails 12. The grippers 16 fixedly connected to the upper surface of the three reciprocating blocks 15 also retract synchronously. At this time, the radius of the circle formed by the three grippers 16 is at its minimum. The connecting rod 161 axially slidingly connected inside the grippers 16 synchronously drives the positioning block 2 fixedly connected to its top to retract, and the radius of the circle formed by the three positioning blocks 2 is also at its minimum.

[0034] At this time, the positioning block 2 is not in contact with the external silicon ring and is in a standby position. Inside the movable cavity 24 of the positioning block 2, the compression spring 252 of the linkage 25 is in a naturally extended state. The compression spring 252 is sleeved on the outer circumferential surface of the horizontal rod 251, with one side in contact with the inner wall of the outer side of the positioning block 2, and the other side pushing the semicircular block 22 and the horizontal rod 251 fixedly connected to the semicircular block 22 to extend horizontally outward along the interior of the movable cavity 24. Because the side of the semicircular block 22 away from the annular plate 33 is designed with an arc surface, after the semicircular block 22 extends outward, the radius of the circle formed by the three semicircular blocks 22 is greater than the radius of the circle formed by the three positioning blocks 2, meaning the semicircular block 22 protrudes from the outer surface of the positioning block 2, forming a pre-clamping circle larger than the outer diameter of the positioning block 2.

[0035] Meanwhile, the abutment plate 257, fixedly connected to the inner end of the horizontal rod 251, is also positioned on the side away from the axis of the locating pin 4 within its stroke range under the push of the compression spring 252. The side of the abutment plate 257 away from the axis of the locating pin 4 is the outer side, and the outer surface of the abutment plate 257 contacts the outer arc end of the rotating rod 255. Under the push of the abutment plate 257, the shaft 256, fixedly connected to the inner end of the outer end of the rotating rod 255, slides horizontally along the inside of the movable cavity 24 to the side away from the locating pin 4 within its stroke range.

[0036] Because the middle part of the rotating rod 255 is hinged to the vertical rod 253, when the shaft 256 is located away from the locating pin 4, the rotating rod 255 is tilted, and the height of the inner end of the rotating rod 255 is higher than the height of the shaft 256. The hinge at the inner end of the rotating rod 255 drives the vertical rod 253 to move upward, so that the lower pressure plate 23, which is fixedly connected to the top of the vertical rod 253, is located at the highest point within its stroke range. At this time, the distance from the lower surface of the lower pressure plate 23 to the upper surface of the annular plate 33 is greater than the height of the silicon ring, providing sufficient space for the insertion of the silicon ring.

[0037] Furthermore, in the initial state, the damping element 32 between the base 3 and the annular plate 33 is in equilibrium. The guide rod 321 can slide vertically inside the base 3, and the baffle 322 restricts the downward limit position of the guide rod 321. The springs 323 are symmetrically distributed on the upper and lower sides of the base 3, providing bidirectional elastic support for the annular plate 33. The positioning pin 4, which is fixedly connected in the middle of the base 3, extends upward and passes through the hollow area in the middle of the annular plate 33. The free end of the positioning pin 4 protrudes upward from the upper surface of the annular plate 33. Since the axis of the positioning pin 4 coincides with the axis of the connecting seat 13, it ensures that the contraction center of the centering mechanism 1 is consistent with the pre-positioning center of the silicon ring, laying the foundation for subsequent precise centering.

[0038] The process of radially positioning the silicon ring: When the silicon ring needs to be transferred, the operator or the loading robot places the silicon ring on the upper surface of the annular plate 33. During placement, the hollow area in the middle of the silicon ring is aligned with the positioning pin 4, and the part of the positioning pin 4 protruding upward from the annular plate 33 is inserted into the hollow area in the middle of the silicon ring. After the silicon ring is placed, its center is roughly aligned with the axis of the positioning pin 4, thereby ensuring that the force on the three grippers 16 is uniform during subsequent centering and clamping.

[0039] After the silicon ring is placed, the rotary cylinder 11 is vented and driven, and the output end of the rotary cylinder 11 drives the connecting seat 13 to rotate. The rotation of the connecting seat 13 is converted into the reciprocating block 15 sliding radially along the guide rail 12 through the crank 14. The three cranks 14 synchronously push the three reciprocating blocks 15 to unfold outward along the three guide rails 12, and the three grippers 16 open outward in sync. When the grippers 16 open outward, the grippers 16 slide along the opening direction of the slide groove 31 of the base 3, and the connecting rod 161 axially connected inside the grippers 16 synchronously drives the positioning block 2 to slide outward along the limiting groove 331 of the annular plate 33. Since the limiting groove 331, the guide rail 12 and the slide groove 31 coincide in the vertical direction, the positioning block 2 always maintains good cooperation with the slide groove 31 and the limiting groove 331 during the radial sliding process, and the sliding is smooth and without jamming.

[0040] As the positioning block 2 moves outward, the semicircular blocks 22 embedded on the outer surface of the positioning block 2 gradually approach the inner circumference of the silicon ring. Since the radius of the circle formed by the three semicircular blocks 22 is greater than the radius formed by the three positioning blocks 2 in the initial state, the semicircular blocks 22 contact the inner circumference of the silicon ring before the positioning blocks 2. Once the arc surface of the semicircular blocks 22 contacts the inner circumference of the silicon ring, the semicircular blocks 22 are blocked by the inner wall of the silicon ring and cannot continue to move outward with the positioning blocks 2.

[0041] At this time, the centering mechanism 1 continues to drive the positioning block 2 to unfold outward. Since the semicircular block 22 has already contacted and been blocked by the inner wall of the silicon ring, relative movement occurs between the semicircular block 22 and the positioning block 2. During this process, the semicircular block 22 gradually retracts relative to the positioning block 2, and the gap between the two gradually decreases. The compression spring 252, which is sleeved on the outer circumference of the horizontal rod 251, is compressed. With the positioning block 2 as the reference, the semicircular block 22, the horizontal rod 251, and the abutment plate 257 fixedly connected to the inner end of the horizontal rod 251 slide horizontally along the inside of the movable cavity 24 toward the positioning pin 4.

[0042] During the inward movement of the semicircular block 22, horizontal rod 251, and abutment plate 257, the vertical rod 253 at the bottom of the lower pressure plate 23 is always subjected to the tension of its bottom end spring 254. As the abutment plate 257 slides inward, the abutment force of the outer side of the abutment plate 257 against the outer end of the arc of the rotating rod 255 gradually disappears. Since the elastic clamping force of the compression spring 252 is greater than the elastic tension of the tension spring 254, the abutment plate 257 remains in contact with the outer end of the rotating rod 255 before the semicircular block 22 is fully retracted; as the semicircular block 22 continues to retract inward, the abutment plate 257 moves further inward, and when the abutment plate 257 separates from the outer end of the rotating rod 255, the outer end of the rotating rod 255 loses the thrust support of the abutment plate 257.

[0043] Under the tension of the tension spring 254, the lower pressure plate 23 and the vertical rod 253 fixedly connected to it slide vertically downwards inside the movable cavity 24. The downward movement of the vertical rod 253 drives the rotating rod 255, which is hinged in the middle, to rotate. The shaft 256, which is fixedly connected to the outer end of the rotating rod 255, slides horizontally inside the movable cavity 24 and moves towards the locating pin 4. As the shaft 256 moves inwards, the inclination of the rotating rod 255 gradually decreases, and the rotating rod 255 gradually transitions from an inclined state to a horizontal state. The lower pressure plate 23 continues to move downwards and gradually approaches the upper surface of the silicon ring.

[0044] When the centering mechanism 1 drives the positioning block 2 to move outward to its limit position, the semicircular block 22 is fully embedded on the outside of the positioning block 2. At this time, the arc surface of the semicircular block 22 coincides with the outer surface of the positioning block 2, and the semicircular block 22 no longer protrudes from the outer surface of the positioning block 2. The semicircular block 22, the horizontal rod 251, and the abutment plate 257 are located on the side closest to the positioning pin 4 within their stroke range. The compression spring 252 is compressed to its maximum compression, and a stable radial clamping force is applied to the inner wall of the silicon ring through the semicircular blocks 22. The three semicircular blocks 22 clamp the inner wall of the silicon ring synchronously and uniformly from three directions, achieving precise centering of the silicon ring.

[0045] The process of axially fixing the silicon ring: As the semicircular block 22 retracts completely, the abutment plate 257 separates from the outer end of the rotating rod 255. Under the tension of the tension spring 254, the vertical rod 253 drives the lower pressure plate 23 downward to the lowest point within its stroke range, and the rotating rod 255 gradually approaches a horizontal state. At this time, the lower surface of the lower pressure plate 23 is tightly attached to the upper surface of the silicon ring, pressing the silicon ring tightly against the upper surface of the annular plate 33. Because the lower surface of the lower pressure plate 23 is covered with a flexible layer, the flexible layer undergoes elastic deformation during compression, ensuring full contact with the upper surface of the silicon ring while avoiding damage to the surface of the silicon ring caused by hard contact.

[0046] Since the elastic coefficient of the compression spring 252 is greater than that of the tension spring 254, and the elastic clamping force of the compression spring 252 is greater than that of the elastic tension of the tension spring 254, the compression spring 252 can provide sufficient radial clamping force during the clamping process to ensure reliable centering of the silicon ring in the radial direction; while the tension spring 254 provides appropriate axial clamping force, so that the lower pressure plate 23 presses the silicon ring against the upper surface of the annular plate 33 without crushing the silicon ring, thus achieving a reasonable distribution of radial centering and axial clamping.

[0047] Since the lower surface of the lower pressure plate 23 is lower than the upper surface of the semicircular block 22 when it is at its lowest point within its stroke range, for silicon rings with a thickness less than the height of the semicircular block 22, the lower pressure plate 23 can still tightly press the silicon ring against the upper surface of the annular plate 33 when it descends to its lowest point, achieving reliable clamping of thin silicon rings. For thicker silicon rings, the lower pressure plate 23 stops descending after contacting the upper surface of the silicon ring, and the tension spring 254 is stretched to the corresponding length, which can also provide reliable clamping force. Therefore, this fixture can adapt to silicon rings of various thicknesses without adjustment, improving the versatility and production flexibility of the fixture.

[0048] The damping process of damping component 32: This invention effectively absorbs impact energy during transportation through the shock absorber 32. When the AGV body moves upwards and bumps, the annular plate 33 is subjected to the downward inertial force of the silicon ring. The annular plate 33 drives the guide rod 321 to slide vertically downwards along the inside of the base 3. The baffle 322 at the bottom of the guide rod 321 limits the downward limit position of the guide rod 321, preventing the annular plate 33 from rigidly colliding with the base 3. At this time, the spring 323 located above the base 3 is compressed to absorb the downward impact energy; the spring 323 located below the base 3 is stretched to provide a rebound force. When the AGV body moves downwards and bumps, the annular plate 33 drives the silicon ring to jump upwards, the guide rod 321 slides upwards along the inside of the base 3, the spring 323 located below the base 3 is compressed to absorb the upward impact energy; the spring 323 located above the base 3 is stretched to provide a rebound force. Since each guide rod 321 is fitted with two springs 323 on its outer circumference, and the two springs 323 are symmetrically distributed on the upper and lower sides of the base 3, the shock absorber 32 forms a bidirectional buffer structure. Whether the annular plate 33 floats up or down, it can be effectively buffered by the springs 323, which greatly reduces the impact force transmitted to the silicon ring.

[0049] During the up-and-down movement of the annular plate 33, the positioning block 2, through the cooperation of its upper and lower sets of limiting blocks 21 on its outer surface with the limiting groove 331 inside the annular plate 33, slides synchronously up and down with the annular plate 33. Since the limiting groove 331 and the sliding groove 31 coincide in the vertical direction, when the positioning block 2 slides up and down with the annular plate 33, the gripper 16 slides synchronously up and down within the sliding groove 31, ensuring the follow-up cooperation between the centering mechanism 1 and the annular plate 33. This follow-up structure ensures that the silicon ring always moves synchronously with the annular plate 33 during transportation, avoiding relative displacement and friction between the silicon ring and the clamping components, and further protecting the silicon ring.

[0050] Meanwhile, during transportation, the semicircular block 22, under the continuous action of the compression spring 252, consistently applies a stable radial clamping force to the inner wall of the silicon ring, while the lower pressure plate 23, under the continuous action of the tension spring 254, consistently presses the silicon ring tightly against the upper surface of the annular plate 33, ensuring reliable fixation of the silicon ring in both radial and axial directions. Even when the AGV generates lateral acceleration during turning or emergency braking, the three-jaw synchronous clamping structure can evenly distribute the lateral force, preventing the silicon ring from shifting or falling off.

[0051] The material feeding process: Once the AGV carrying the silicon ring arrives at the target workstation, the unloading operation is performed. During unloading, the rotary cylinder 11 is driven by reverse airflow, and the output end of the rotary cylinder 11 drives the connecting seat 13 to rotate in the opposite direction. The rotation of the connecting seat 13 drives the reciprocating block 15 to slide along the guide rail 12 towards the central axis of the base 3 through the crank 14, and the three grippers 16 retract synchronously.

[0052] When the gripper 16 retracts, the connecting rod 161 drives the positioning block 2 to slide inward synchronously along the slide groove 31 and the limiting slot 331. The semicircular block 22 on the outer surface of the positioning block 2 retracts inward along with the positioning block 2, gradually disengaging from the contact with the inner wall of the silicon ring circumference. After the semicircular block 22 disengages from the inner wall of the silicon ring, it loses the constraint of the inner wall of the silicon ring. Under the action of the elastic restoring force, the compression spring 252 sleeved on the outer surface of the horizontal rod 251 pushes the semicircular block 22, the horizontal rod 251, and the abutment plate 257 to slide horizontally outward along the inside of the movable cavity 24. The semicircular block 22 protrudes outward from the outer surface of the positioning block 2 again, returning to the outward position of the initial state.

[0053] During the outward movement of the abutment plate 257, the outer surface of the abutment plate 257 re-contacts the outer arc end of the rotating rod 255, pushing the outer end of the rotating rod 255 outward. The shaft 256, which is fixedly connected inside the outer end of the rotating rod 255, slides horizontally along the inside of the movable cavity 24 to the side away from the positioning pin 4, and the rotating rod 255 changes from a horizontal state back to an inclined state, raising the height of the inner end of the rotating rod 255. The raising of the inner end of the rotating rod 255 causes the vertical rod 253 and the lower pressure plate 23 to slide vertically upward along the inside of the movable cavity 24. The lower pressure plate 23 gradually detaches from the upper surface of the silicon ring and moves upward to the highest point within its stroke range, releasing the axial pressure on the silicon ring.

[0054] Once the pressure plate 23 is completely detached from the upper surface of the silicon ring and the semicircular block 22 is completely detached from the inner wall of the silicon ring, the silicon ring is in a free state. At this time, the operator or the unloading robot removes the silicon ring from the annular plate 33, completing the unloading operation. After unloading is completed, the centering mechanism 1 returns to its initial contracted state, and all components are reset, awaiting the next placement and transfer of the silicon ring.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. An AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture, characterized in that, include: Centering mechanism (1), the centering mechanism (1) includes a rotary cylinder (11), a guide rail (12) is provided on the outside of the rotary cylinder (11), three guide rails (12) are provided, the three guide rails (12) are evenly distributed in a circle around the rotary cylinder (11), the output end of the rotary cylinder (11) is connected to a connecting seat (13), the upper surface of the connecting seat (13) is hinged to a crank (14), the outer end of the crank (14) is hinged to a reciprocating block (15), the reciprocating block (15) is slidably connected to the upper surface of the guide rail (12), the upper surface of the reciprocating block (15) is fixedly connected to a gripper (16), the inside of the gripper (16) is axially slidably connected to a connecting rod (161), the top end of the connecting rod (161) is fixedly connected to a positioning block (2); The base (3) has a groove (31) inside for accommodating the sliding of the gripper (16). The base (3) is connected to an annular plate (33) through a shock absorber (32) inside it. The annular plate (33) is located above the base (3) and is used to place an external silicon ring. The annular plate (33) has a limiting groove (331) inside for accommodating the sliding of the positioning block (2). The outer surface of the positioning block (2) is provided with a limiting block (21) that fits against the inner wall of the limiting groove (331).

2. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 1, characterized in that: A positioning pin (4) is fixedly connected to the middle of the base (3), and the positioning pin (4) extends upward and passes through the hollow area in the middle of the annular plate (33).

3. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 2, characterized in that: The shock absorber (32) includes a guide rod (321) that slides vertically inside the base (3). The top end of the guide rod (321) is fixedly connected to the lower surface of the annular plate (33). The bottom end of the guide rod (321) passes through the base (3) and is fixedly connected to a baffle plate (322). A spring (323) connected to the outer surface of the base (3) is sleeved on the outer circumference of the guide rod (321).

4. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 3, characterized in that: Two springs (323) are fitted on the outer circumference of each guide rod (321), and the two springs (323) are symmetrically distributed on the upper and lower sides of the base (3).

5. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 1, characterized in that: The outer surface of the positioning block (2) is embedded with a semi-circular block (22), and a pressure plate (23) is provided above the positioning block (2). The positioning block (2) is provided with a linkage (25) through the movable cavity (24) opened inside it.

6. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 5, characterized in that: The side of the semicircular block (22) away from the annular plate (33) is designed with an arc surface that fits into the inner wall surface of the silicon ring, while the side of the semicircular block (22) close to the annular plate (33) is a flat surface.

7. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 6, characterized in that: The linkage (25) includes a horizontal rod (251) that slides horizontally inside the movable cavity (24). The outer end of the horizontal rod (251) extends to the outside of the positioning block (2) and is fixedly connected to the inner surface of the semicircular block (22) near the annular plate (33). A compression spring (252) is sleeved on the outer circumference of the horizontal rod (251).

8. The AGV-mounted three-jaw synchronous pneumatic self-centering workpiece positioning fixture according to claim 7, characterized in that: The lower surface of the lower pressure plate (23) is fixedly connected to a vertical rod (253) that slides vertically inside the movable cavity (24). The bottom end of the vertical rod (253) is provided with a tension spring (254) that is connected to the bottom end of the inner wall of the movable cavity (24). A rotating rod (255) is hinged to the middle of the vertical rod (253). The outer end of the rotating rod (255) is fixedly connected to a shaft (256) that slides horizontally inside the movable cavity (24). The inner end of the horizontal rod (251) is fixedly connected to an abutment plate (257) that fits against the outer end of the rotating rod (255).

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