High-precision indexing device for machining

Abstract

This invention belongs to the field of indexing devices and discloses a high-precision indexing device for machining. The rotary drive assembly is arranged inside the indexing worktable. From bottom to top, a slotted indexing plate and a graduated indexing plate are arranged sequentially on the upper part of the indexing worktable. A locking assembly is also installed on the indexing worktable to lock and position the slotted indexing plate. The rotary drive assembly is connected to both the graduated and slotted indexing plates. The rotary drive assembly is connected to a workpiece clamping assembly, and a self-locking engagement is formed between the piston rod of the workpiece clamping assembly and the workpiece clamping base. This invention provides a high-precision indexing device for machining, where both rotary indexing and workpiece clamping exhibit high rigidity, excellent overall precision retention, and suitability for multi-station, multi-angle precision machining applications, making it highly practical.

Description

Technical Field

[0001] This invention relates to the field of indexing device technology, and in particular to a high-precision indexing device for machining. Background Technology

[0002] Indexing devices are crucial equipment in the machining field for achieving angular rotational positioning of workpieces. They are widely used in drilling, milling, tapping, boring, and multi-station precision machining. Existing indexing devices typically achieve workpiece angular indexing through worm gears, ratchet mechanisms, CNC rotary tables, or simple pin-hole positioning structures, and are used in conjunction with chucks, pressure plates, or pneumatic fixtures to fix the workpiece. However, with the increasing demands for machining accuracy in products such as aerospace components, communication structural parts, precision molds, and automated equipment parts, traditional indexing devices are gradually revealing their shortcomings in high-precision, high-stability, and multi-station continuous machining scenarios.

[0003] Many existing mechanical indexing devices use a single worm gear drive structure for angle indexing. While this achieves basic rotational functionality, over long-term use, the worm gear pair is prone to backlash errors due to backlash wear. This is especially problematic under heavy cutting loads, leading to issues such as indexing angle deviation, rotational jitter, and increased backlash. Consequently, the coaxiality and angular consistency of machined holes decrease, making it difficult to meet high-precision machining requirements. Although some devices incorporate braking structures, most rely on a single locking method with insufficient locking rigidity. Under periodic cutting force impacts during milling or drilling, the central shaft may still experience slight rotation, affecting workpiece machining accuracy and surface quality.

[0004] Furthermore, existing slotted indexing structures typically use locating pins directly inserted into the indexing slots for positioning. This type of structure is prone to slot wear, increased positioning gaps, and significant positioning impact noise during frequent insertion and removal. Some devices use cylinders to drive the pins for locking, which introduces instantaneous impact during positioning. Over time, this can cause deformation of the positioning edges, reducing repeatability and indexing accuracy. Additionally, traditional positioning mechanisms often lack buffer transition structures, making them susceptible to positioning vibrations and structural fatigue during high-speed or continuous indexing processes.

[0005] In terms of workpiece clamping, existing indexing tables mostly use three-jaw chucks, bolt clamping plates, or single pneumatic clamping structures to fix the workpiece. Among them, traditional mechanical clamping plates require repeated manual adjustments, resulting in low clamping efficiency and uneven distribution of clamping force, which can easily cause deformation of thin-walled or irregularly shaped workpieces. While single pneumatic clamping methods have a certain degree of automation, once the air pressure fluctuates or the air circuit leaks during processing, the clamping stability will decrease, which can easily lead to workpiece loosening or displacement, especially during multi-angle continuous cutting, which is more likely to generate vibration and processing errors.

[0006] While some existing rotary clamps can achieve airflow during rotation, most employ simple rotary joint structures with limited sealing performance. Under prolonged high-speed rotation, issues such as air leakage, seal wear, and unstable air pressure can arise, affecting the reliability of the clamping action. Furthermore, existing clamps struggle to balance rapid clamping with reliable self-locking; some devices require manual assistance for locking, resulting in low automation levels and failing to meet the requirements of modern precision machining equipment for rapid changeovers, high stability, and continuous processing.

[0007] Existing indexing devices also suffer from insufficient structural adaptability. Some indexing platforms are only suitable for workpieces of fixed specifications. When multi-station, multi-angle, or different types of workpieces need to be processed, frequent changes of fixtures and positioning structures are required, which not only increases setup time but also reduces processing efficiency. Especially in the continuous processing of complex parts, traditional structures cannot simultaneously meet the requirements of high-precision indexing, high-rigidity locking, and rapid clamping.

[0008] Therefore, how to provide a high-precision indexing device for machining that can achieve high-precision angle indexing, has dual anti-reverse locking capability, can stably withstand cutting impact loads, and has both automated fast clamping and highly reliable self-locking functions, and can be applied to multi-station, multi-angle precision machining scenarios, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above and to provide a high-precision indexing device for machining.

[0010] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0011] A high-precision indexing device for machining includes a graduated indexing plate, a slotted indexing plate, an indexing worktable, a locking assembly, a rotary drive assembly, and a workpiece clamping assembly. The rotary drive assembly is arranged inside the indexing worktable. The slotted indexing plate and the graduated indexing plate are arranged sequentially from bottom to top on the upper part of the indexing worktable. A locking assembly is also mounted on the indexing worktable for locking and positioning the slotted indexing plate. The rotary drive assembly is connected to both the graduated indexing plate and the slotted indexing plate.

[0012] The workpiece clamping assembly includes a chassis, an intermediate air passage core, an air passage rotary cylinder, bearings, a piston, a compression spring, a piston rod, and an upper cylinder cover; the rotary drive assembly is connected to the chassis via a transmission; the intermediate air passage core is fixedly mounted on the upper end of the chassis; the air passage rotary cylinder is rotatably sleeved on the outside of the intermediate air passage core via bearings, and is rotatably mounted on the upper end of the chassis; there is an air passage gap between the air passage rotary cylinder and the intermediate air passage core; the intermediate air passage core has a piston chamber with an open upper end; the air passage rotates... The cylinder body has an air passage connector on its outer circumferential surface, and a vent hole is opened at the bottom of the circumferential surface of the intermediate air passage core. The piston chamber, air passage connector and vent hole are connected. A piston is slidably installed inside the piston chamber, and a piston rod is fixedly installed at the upper end of the piston. The upper cylinder head is sealed and fixedly connected to the intermediate air passage core. The upper end of the compression spring abuts against the inner wall of the upper cylinder head and the lower end abuts against the inner wall of the piston chamber, and the compression spring is always in a compressed state. The piston rod passes through the upper cylinder head, and a self-locking engagement is formed between the piston rod and the workpiece clamping base.

[0013] In one embodiment, the rotary drive assembly includes a first motor, a lead screw, a linear rack, a circular gear, a central shaft, a ratchet, and a pawl. The first motor is mounted externally on the indexing table, and the output shaft of the first motor is fixedly connected to the lead screw. The lead screw passes through the indexing table and is threadedly connected to the linear rack. The linear rack is slidably mounted on a linear slide, and the linear slide is fixedly disposed inside the indexing table. One side of the linear rack's teeth meshes with the outer side of the circular gear's teeth. The circular gear is rotatably disposed inside the indexing table via the central shaft. A ratchet is fixedly sleeved on the outside of the central shaft, and the pawl is rotatably disposed inside the indexing table, meshing with the ratchet's tooth groove. The upper end of the central shaft passes through and extends out of the indexing table, and the central shaft is fixedly connected to a graduated indexing plate and a slotted indexing plate, respectively.

[0014] In one embodiment, a rotary worktable is fixedly connected to the top of the central rotating shaft, and the rotary worktable is rotatably disposed on the upper end of the graduated dial; the rotary worktable is detachably connected to the chassis.

[0015] In one embodiment, the outer circumferential surface of the graduated dial is provided with angle scale markings.

[0016] In one embodiment, the outer edge of the slotted indexing plate is evenly provided with a plurality of indexing slots along the circumferential direction; the locking assembly includes a second motor and a cam; the second motor is fixedly mounted on the indexing worktable, and the output shaft of the second motor is fixedly connected to the rotation center hole of the cam; when the cam rotates to the locked position, its far rest arc segment is embedded in the indexing slot to achieve positioning; when the cam rotates 180° to the unlocked position, its near rest arc segment forms an avoidance gap with the indexing slot.

[0017] In one embodiment, the inner wall of the air passage rotary cylinder is provided with a plurality of sealing grooves, and an inner sealing ring is embedded in the sealing groove;

[0018] The mating end face of the upper cylinder head and the intermediate air passage core is provided with a sealing groove, and an outer sealing ring is embedded in the sealing groove;

[0019] The mating end face of the upper cylinder head and the piston rod is provided with a sealing groove, and a skeleton sealing ring is embedded in the sealing groove.

[0020] In one embodiment, two air passage connectors are provided, namely a piston extension air passage connector and a piston retraction air passage connector.

[0021] In one embodiment, the piston rod protrudes at the top to form an arc portion, and the arc surface of the arc portion smoothly slopes and transitions from the top to both sides.

[0022] The piston rod has a receiving groove at the middle of its top end, and the receiving groove has a star-shaped cross-section.

[0023] In one embodiment, the upper cylinder head supports a workpiece clamping base; the top of the workpiece clamping base has a flange face and the bottom is open; the inner diameter of the bottom opening of the workpiece clamping base is larger than the outer diameter of the piston rod; a connecting rod is fixedly provided on the inner top wall of the flange face of the workpiece clamping base at the position corresponding to the receiving groove; the cross-section of the connecting rod is a star-shaped structure, and the connecting rod can be adapted to fit into the receiving groove when it descends.

[0024] In one embodiment, a plurality of locking grooves are evenly provided on the lower circumferential surface of the workpiece clamping base, and each locking groove is provided with a workpiece clamping base locking component.

[0025] The workpiece clamping base locking assembly includes a locking rod, a locking rod end, a locking block, and a tension spring. The locking rod end is fixedly attached to the outer end of the locking rod extending out of the workpiece clamping base, and the inner end of the locking rod extending into the locking groove is fixedly connected to the locking block. The locking block is adapted to the contour dimensions of the locking groove and can slide along the locking groove. A tension spring is sleeved on the outer side of the locking rod, the outer end of the tension spring is connected to the inner wall of the workpiece clamping base, and the inner end abuts against the locking block. The bottom surface of the locking block is an arc surface, and the arc surface smoothly slopes towards the inner side of the workpiece clamping base from the bottom.

[0026] When the upper end of the locking block abuts against the lower end of the arc portion, and the inner end face of the locking block abuts against the corresponding end face of the locking rod, the tension spring is in a compressed state.

[0027] Compared with existing technologies, the beneficial effects of this invention are:

[0028] (1) The present invention uses gear rack transmission to achieve precise angle indexing. Combined with ratchet pawl anti-reverse locking and cam groove indexing plate positioning double locking structure, it can effectively withstand cutting resistance, prevent the central shaft from reversing, and significantly improve indexing accuracy and working stability.

[0029] (2) The workpiece of the present invention adopts a dual locking clamping method of mechanical elastic clamping and pneumatic negative pressure adsorption. It relies on the spring elastic pre-tightening force to form continuous clamping, and further reinforces it with negative pressure adsorption. It can completely avoid displacement and vibration of the workpiece during processing, and the clamping stability and reliability are strong.

[0030] (3) The present invention can drive the workpiece to complete multi-angle indexing rotation synchronously with the rotary table, and flexibly adapt to multiple precision machining processes such as drilling and milling under different work positions, with good machining adaptability.

[0031] (4) The present invention has a compact and reasonable overall structure, and both the rotation indexing and workpiece clamping have high rigidity characteristics. It has excellent overall accuracy retention and is suitable for precision machining occasions with multiple stations and multiple angles. It is highly practical. Attached Figure Description

[0032] Figure 1 A perspective view of a high-precision indexing device for machining provided in an embodiment of the present invention;

[0033] Figure 2 This is a front view of a high-precision indexing device for machining provided in an embodiment of the present invention;

[0034] Figure 3 This is a top view of a high-precision indexing device for machining provided in an embodiment of the present invention;

[0035] Figure 4 for Figure 3 Sectional view along line AA in the middle;

[0036] Figure 5 for Figure 4 Enlarged view of part A in the image;

[0037] Figure 6 This is a front sectional view of a high-precision indexing device for machining without a workpiece clamping base provided in an embodiment of the present invention.

[0038] Figure 7 This is an exploded view of the workpiece clamping assembly provided in an embodiment of the present invention;

[0039] Figure 8 This is a schematic diagram of the internal structure of the indexing worktable provided in an embodiment of the present invention.

[0040] Explanation of reference numerals in the attached diagram: 1. Indexing table; 2. Slotted indexing plate; 21. Indexing slot; 3. Graduated indexing plate; 4. Rotary table;

[0041] 5. Rotary drive assembly; 51. First motor; 52. Lead screw; 53. Linear slide; 54. Linear rack; 55. Circular gear; 56. Central shaft; 57. Ratchet; 58. Pawl;

[0042] 6. Locking assembly; 61. Second motor; 62. Cam;

[0043] 7. Workpiece clamping assembly; 701. Chassis; 702. Intermediate air passage core; 703. Piston chamber; 704. Vent hole; 705. Air passage rotating cylinder; 706. Air passage clearance; 707. Piston extension air passage connector; 708. Piston retraction air passage connector; 709. Inner sealing ring; 710. Bearing; 711. Piston; 712. Piston rod; 713. Arc portion; 714. Receiving groove; 715. Upper cylinder head; 716. Outer sealing ring; 717. Skeleton sealing ring; 718. Compression spring;

[0044] 8. Workpiece clamping base; 81. Flange face; 82. Connecting rod; 83. Locking groove; 84. Locking rod; 85. Locking rod end; 86. Locking block; 87. Tension spring. Detailed Implementation

[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0046] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] Example

[0049] like Figure 1-8 As shown, a high-precision indexing device for machining includes a graduated indexing plate 3, a slotted indexing plate 2, an indexing worktable 1, a locking assembly 6, a rotary drive assembly 5, and a workpiece clamping assembly 7.

[0050] The indexing worktable 1 is equipped with a rotary drive assembly 5. The upper part of the indexing worktable 1 is arranged from bottom to top with a slotted indexing plate 2 and a graduated indexing plate 3.

[0051] The outer circumference of the graduated dial 3 is marked with angle markings, which makes it easy for operators to read the current rotation angle intuitively.

[0052] The indexing table 1 is also equipped with a locking assembly 6, which is used to lock and position the slotted indexing plate 2. The rotary drive assembly 5 is connected to the graduated indexing plate 3 and the slotted indexing plate 2 respectively to drive them to rotate synchronously to achieve angle indexing.

[0053] The rotary drive assembly 5 includes a first motor 51, a lead screw 52, ​​a linear rack 54, a circular gear 55, a central rotating shaft 56, a ratchet 57, and a pawl 58. The first motor 51 is mounted externally on the indexing table 1, and its output shaft is fixedly connected to the lead screw 52. The lead screw 52 passes through the indexing table 1 and is threadedly connected to the linear rack 54. The linear rack 54 is slidably mounted on a linear slide 53, which is fixedly located inside the indexing table 1. One side of the linear rack 54 meshes with the outer side of the circular gear 55. The circular gear 55 is rotatably mounted inside the indexing table 1 via the central rotating shaft 56. A ratchet 57 is fixedly sleeved externally on the central rotating shaft 56, and a pawl 58 is rotatably mounted inside the indexing table 1. The pawl 58 meshes with the tooth groove of the ratchet 57 to prevent the central rotating shaft 56 from rotating in the opposite direction. The upper end of the central rotating shaft 56 passes through and extends out of the indexing worktable 1. The central rotating shaft 56 is fixedly connected to the graduated indexing plate 3 and the slotted indexing plate 2 respectively, thereby driving the two to rotate synchronously.

[0054] The locking assembly 6 includes a second motor 61 and a cam 62. The second motor 61 is fixed on the indexing table 1, and the rotation center hole of the cam 62 is connected to the output shaft of the second motor 61. The outer edge of the slotted indexing plate 2 is evenly provided with a plurality of indexing slots 21 along the circumferential direction.

[0055] The workpiece clamping assembly 7 includes a chassis 701, an intermediate air passage core 702, an air passage rotary cylinder 705, a bearing 710, a piston 711, a compression spring 718, a piston rod 712, and an upper cylinder head 715. A rotary worktable 4 is fixedly connected to the top of the central shaft 56 of the rotary drive assembly 5. The rotary worktable 4 is rotatably mounted on the upper end of the graduated dial 3; the rotary worktable 4 and the chassis 701 are detachably connected by threads. Thus, when the central shaft 56 rotates, it sequentially drives the rotary worktable 4, the chassis 701, and the entire workpiece clamping assembly 7 to rotate.

[0056] An intermediate air passage core 702 is fixedly mounted on the upper end of the chassis 701. An air passage rotary cylinder 705 is rotatably sleeved on the outside of the intermediate air passage core 702 via a bearing 710, and is rotatably mounted on the upper end of the chassis 701. An air passage gap 706 exists between the air passage rotary cylinder 705 and the intermediate air passage core 702. A piston chamber 703 with an upper opening is opened inside the intermediate air passage core 702. An air passage connector is provided on the outer circumferential surface of the air passage rotary cylinder 705; specifically, two air passage connectors are provided: a piston extension air passage connector 707 and a piston retraction air passage connector 708. A vent hole 704 is opened at the bottom end of the circumferential surface of the intermediate air passage core 702. The piston chamber 703, the piston extension air passage connector 707, and the piston retraction air passage connector 708 are all connected through the air passage gap 706 and the vent hole 704, thereby realizing the control of the charging and discharging of the piston chamber 703.

[0057] A piston 711 is slidably mounted inside the piston chamber 703, and a piston rod 712 is fixedly mounted on the upper end of the piston 711. The upper cylinder head 715 is sealed and fixedly connected to the intermediate air passage core 702. The upper end of the compression spring 718 abuts against the inner wall of the upper cylinder head 715, and the lower end abuts against the inner wall of the piston chamber 703. The compression spring 718 is always in a compressed state, applying a downward elastic force to the piston 711. The piston rod 712 extends out of the upper cylinder head 715, and a self-locking engagement is formed between the piston rod 712 and the workpiece clamping base 8.

[0058] To enhance sealing, the inner wall of the rotary cylinder 705 is provided with several sealing grooves, and an inner sealing ring 709 is embedded in the sealing groove; the mating end face of the upper cylinder cover 715 and the intermediate air passage core 702 is provided with a sealing groove, and an outer sealing ring 716 is embedded in the sealing groove; the mating end face of the upper cylinder cover 715 and the piston rod 712 is provided with a sealing groove, and a skeleton sealing ring 717 is embedded in the sealing groove.

[0059] Multiple sealing structures (inner sealing ring 709, outer sealing ring 716, and skeleton sealing ring 717) ensure the reliability of the pneumatic system and prevent leakage.

[0060] The piston rod 712 has a protruding arc-shaped portion 713 at its top, with the arc surface of the portion 713 smoothly sloping towards both sides. A receiving groove 714 is formed in the middle of the top of the piston rod 712, and the cross-section of the receiving groove 714 is star-shaped. The upper cylinder head 715 supports and holds the workpiece clamping base 8. The workpiece clamping base 8 has a flange face 81 at its top and an opening at its bottom. The flange face 81 is used to connect the workpiece to be processed. The inner diameter of the bottom opening of the workpiece clamping base 8 is larger than the outer diameter of the piston rod 712, allowing the piston rod 712 to extend into it. A connecting rod 82 is fixed to the inner top wall of the flange face 81 of the workpiece clamping base 8, corresponding to the receiving groove 714. The connecting rod 82 has a star-shaped cross-section, adapted to the receiving groove 714, and can fit into the receiving groove 714 when the connecting rod 82 moves downwards. When the piston rod 712 moves upward along with the receiving groove 714, the connecting rod 82 can be embedded in the receiving groove 714 so that the workpiece can rotate with the piston rod to achieve rotation indexing.

[0061] The connecting rod 82 and the receiving groove 714 are fitted with a star-shaped cross section, which not only has the function of preventing rotation, but also transmits torque evenly and avoids the relative slippage that may occur when the round shaft and the round hole are fitted.

[0062] The lower circumferential surface of the workpiece clamping base 8 is evenly provided with several locking grooves 83, and each locking groove 83 contains a workpiece clamping base locking assembly. The locking assembly includes a locking rod 84, a locking rod end 85, a locking block 86, and a tension spring 87. The locking rod end 85 is fixed to the outer end of the locking rod 84 extending out of the workpiece clamping base 8, and the inner end of the locking rod 84 extending into the locking groove 83 is fixed to the locking block 86. The locking block 86 is adapted to the contour dimensions of the locking groove 83 and can slide along the locking groove 83. A tension spring 87 is sleeved on the outer side of the locking rod 84. The outer end of the tension spring 87 is connected to the inner wall of the workpiece clamping base 8, and the inner end abuts against the locking block 86. Under the elastic force of the tension spring 87, the locking block 86 moves inward. The bottom surface of the locking block 86 is an arc surface, which smoothly slopes inward from the bottom to the inner side of the workpiece clamping base 8.

[0063] When the piston rod 712 moves upward, since both the top surface of the piston rod 712 and the bottom surface of the locking block 86 are arc surfaces, the arc portion of the piston rod 712 can pass over the locking block 86 during the lifting process. When the upper end of the locking block 86 abuts against the lower end of the arc portion 713 of the piston rod 712, and the inner end face of the locking block 86 abuts against the corresponding end face of the locking rod 84, the piston extends the air passage connector 707 to stop air intake, the piston rod 712 stops moving upward, the tension spring 87 is in a compressed state, and at this time the locking block 86 is pushed outward to form a locking engagement with the piston rod 712.

[0064] Working principle of the invention:

[0065] When the rotary drive assembly 5 is working, the first motor 51 drives the lead screw 52 to rotate, which in turn drives the linear rack 54 to move along the linear slide 53, thereby causing the circular gear 55 and the central rotating shaft 56 to rotate at a certain angle. The central rotating shaft 56 drives the graduated indexing plate 3, the slotted indexing plate 2, and the rotary table 4 to rotate synchronously. At the same time, the ratchet 57 and the pawl 58 cooperate to prevent the central rotating shaft 56 from reversing under cutting resistance, achieving the first rotational locking, realizing indexing and positioning at a certain angle, and locking the work position.

[0066] Simultaneously, after indexing is complete, the second motor 61 drives the cam 62 to rotate to the locked position. At this point, the far-end arc of the cam 62 is embedded in the indexing groove 21, achieving precise positioning. After the workpiece is processed, when the next indexing is required, the cam 62 first rotates 180° to the unlocked position, and its near-end arc forms a clearance gap with the indexing groove 21, allowing the slotted indexing plate 2 to continue rotating. The cam 62 forms a second rotational lock on the slotted indexing plate 2, further bearing the cutting resistance and locking the work position. The locking mechanism of the ratchet 57 and pawl 58, as well as the locking mechanism of the cam 62 and the indexing groove 21, complement each other, greatly improving the indexing accuracy and stability.

[0067] When clamping the workpiece, the workpiece to be processed is first fixed to the upper end of the workpiece clamping base 8 via the flange face 81. Then, the control piston extends the air passage connector 707 to connect the air source. The gas enters the piston chamber 703 through the piston extension air passage connector 707, the air passage gap 706, and the air vent 704, pushing the piston 711 and piston rod 712 upward. The piston rod 712 drives the arcuate part 713 at its top to move upward, and its arc surface smoothly passes over the bottom arcuate surface of the locking block 86, pushing the locking block 86 outward. At this time, the tension spring 87 is compressed. After the arcuate part 713 has completely passed the locking block 86, the locking block 86 returns to its original position inward under the restoring force of the tension spring 87, and its top end abuts against the lower end face of the arcuate part 713. Since the compression spring 718 is always in a compressed state, it applies a downward elastic force to the piston 711. This elastic force is transmitted to the locking block 86 through the arc portion 713 of the piston rod 712, and then to the workpiece clamping base 8 through the locking block 86, ultimately forming a continuous downward clamping force on the workpiece, thus achieving the first layer of mechanical elastic locking of the workpiece.

[0068] The piston then retracts, connecting the air supply to the air inlet 708 and initiating air extraction. A negative pressure is created within the piston chamber 703, causing the piston rod 712 to experience a downward gas adsorption force. This adsorption force is also transmitted to the workpiece clamping base 8 and the workpiece through the same path, forming a second layer of pneumatic adsorption locking. Under the combined action of mechanical elastic locking and pneumatic adsorption locking, the workpiece remains absolutely stable during processing, preventing displacement or vibration.

[0069] When it is necessary to release the workpiece, first turn off the air extraction, then extend the air passage connector 707 to the piston to introduce compressed air, so that the piston rod 712 moves upward. At the same time, manually pull the locking rod end 85 outward to disengage the locking block 86 from the arc part 713, and then the workpiece clamping base 8 and the workpiece can be removed.

[0070] After the circular gear 55 rotates to a certain angle to complete the angular indexing and positioning, the central rotating shaft 56 drives the rotary table 4 and the entire workpiece clamping assembly 7 to rotate by the same angle. The workpiece clamping assembly 7 drives the piston rod 712 and the workpiece to rotate synchronously, thereby realizing drilling, milling and other machining operations on the workpiece at different angular positions. Since both the rotation indexing and workpiece clamping have double locking, the entire machining process has high precision and good rigidity.

[0071] Therefore, this high-precision indexing device has a compact structure, accurate indexing, and stable workpiece clamping, making it particularly suitable for machining applications requiring multi-station and multi-angle precision machining.

[0072] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims

1. A high-precision indexing device for machining, comprising a graduated indexing plate, a slotted indexing plate, an indexing worktable, a locking assembly, a rotary drive assembly, and a workpiece clamping assembly; characterized in that: The rotary drive assembly is arranged inside the indexing table; a slotted indexing plate and a graduated indexing plate are arranged sequentially from bottom to top on the upper part of the indexing table; a locking assembly is also installed on the indexing table, which is used to lock and position the slotted indexing plate; the rotary drive assembly is connected to the graduated indexing plate and the slotted indexing plate respectively. The workpiece clamping assembly includes a chassis, an intermediate air passage core, an air passage rotary cylinder, bearings, a piston, a compression spring, a piston rod, and an upper cylinder cover; the rotary drive assembly is connected to the chassis via a transmission; the intermediate air passage core is fixedly mounted on the upper end of the chassis; the air passage rotary cylinder is rotatably sleeved on the outside of the intermediate air passage core via bearings, and is rotatably mounted on the upper end of the chassis; there is an air passage gap between the air passage rotary cylinder and the intermediate air passage core; the intermediate air passage core has a piston chamber with an open upper end; the air passage rotates... The cylinder body has an air passage connector on its outer circumferential surface, and a vent hole is opened at the bottom of the circumferential surface of the intermediate air passage core. The piston chamber, air passage connector and vent hole are connected. A piston is slidably installed inside the piston chamber, and a piston rod is fixedly installed at the upper end of the piston. The upper cylinder head is sealed and fixedly connected to the intermediate air passage core. The upper end of the compression spring abuts against the inner wall of the upper cylinder head and the lower end abuts against the inner wall of the piston chamber, and the compression spring is always in a compressed state. The piston rod passes through the upper cylinder head, and a self-locking engagement is formed between the piston rod and the workpiece clamping base.

2. The high-precision indexing device for machining according to claim 1, characterized in that: The rotary drive assembly includes a first motor, a lead screw, a linear rack, a circular gear, a central shaft, a ratchet, and a pawl. The first motor is mounted externally on the indexing table, and its output shaft is fixedly connected to the lead screw. The lead screw passes through the indexing table and is threadedly connected to the linear rack. The linear rack is slidably mounted on a linear slide, which is fixedly located inside the indexing table. One side of the linear rack's teeth meshes with the outer side of the circular gear's teeth. The circular gear is rotatably mounted inside the indexing table via the central shaft. A ratchet is fixedly sleeved on the outside of the central shaft, and the pawl is rotatably mounted inside the indexing table, meshing with the ratchet's tooth groove. The upper end of the central shaft passes through and extends out of the indexing table, and is fixedly connected to both a graduated indexing plate and a slotted indexing plate.

3. The high-precision indexing device for machining according to claim 1, characterized in that: The top of the central rotating shaft is fixedly connected to a rotary worktable, which is rotatably mounted on the upper end of the graduated dial; the rotary worktable is detachably connected to the chassis.

4. The high-precision indexing device for machining according to claim 1, characterized in that: The outer circumference of the graduated dial is marked with angle scale markings.

5. The high-precision indexing device for machining according to claim 1, characterized in that: The outer edge of the slotted indexing plate is evenly provided with several indexing slots along the circumferential direction. The locking assembly includes a second motor and a cam; the second motor is fixed on the indexing worktable, and the output shaft of the second motor is fixedly connected to the rotation center hole of the cam; when the cam rotates to the locked position, its far rest arc segment is embedded in the indexing groove to achieve positioning; when the cam rotates 180° to the unlocked position, its near rest arc segment forms an avoidance gap with the indexing groove.

6. The high-precision indexing device for machining according to claim 3, characterized in that: The inner wall of the rotary cylinder of the air passage is provided with several sealing grooves, and an inner sealing ring is embedded in the sealing groove. The mating end face of the upper cylinder head and the intermediate air passage core is provided with a sealing groove, and an outer sealing ring is embedded in the sealing groove; The mating end face of the upper cylinder head and the piston rod is provided with a sealing groove, and a skeleton sealing ring is embedded in the sealing groove.

7. The high-precision indexing device for machining according to claim 1, characterized in that: The air passage connector is provided in two parts: a piston extension air passage connector and a piston retraction air passage connector.

8. The high-precision indexing device for machining according to claim 1, characterized in that: The piston rod protrudes at the top to form an arc portion, and the arc surface of the arc portion smoothly slopes and transitions from the top to both sides. The piston rod has a receiving groove at the middle of its top end, and the receiving groove has a star-shaped cross-section.

9. A high-precision indexing device for machining according to claim 8, characterized in that: The upper cylinder head supports the workpiece clamping base; the top of the workpiece clamping base has a flange face and the bottom is open; the inner diameter of the bottom opening of the workpiece clamping base is larger than the outer diameter of the piston rod; a connecting rod is fixed on the inner top wall of the flange face of the workpiece clamping base at the position corresponding to the receiving groove; the cross-section of the connecting rod is a star-shaped structure, and the connecting rod can be adapted to fit into the receiving groove when it moves downward.

10. A high-precision indexing device for machining according to claim 8, characterized in that: The lower circumferential surface of the workpiece clamping base is evenly provided with several locking grooves, and each locking groove is provided with a workpiece clamping base locking component. The workpiece clamping base locking assembly includes a locking rod, a locking rod end, a locking block, and a tension spring. The locking rod end is fixedly attached to the outer end of the locking rod extending out of the workpiece clamping base, and the inner end of the locking rod extending into the locking groove is fixedly connected to the locking block. The locking block is adapted to the contour dimensions of the locking groove and can slide along the locking groove. A tension spring is sleeved on the outer side of the locking rod, the outer end of the tension spring is connected to the inner wall of the workpiece clamping base, and the inner end abuts against the locking block. The bottom surface of the locking block is an arc surface, and the arc surface smoothly slopes towards the inner side of the workpiece clamping base from the bottom. When the upper end of the locking block abuts against the lower end of the arc portion, and the inner end face of the locking block abuts against the corresponding end face of the locking rod, the tension spring is in a compressed state.

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