Collet chuck for machine tool machining

Abstract

The utility model relates to a chicken heart chuck for lathe machining, including base and chuck part, the chuck part includes the outer sleeve and inner chuck, the inside groove of inner chuck sets up with the inside key or internal thread of shaft piece outside adaptation, the outside of inner chuck is inserted in the inside of outer sleeve through the limiting piece, the outside of outer sleeve has a plurality of fixed strips to the circumferential array, fixed strip is equipped with a plurality of thread holes three to the axial direction, the inside of outer sleeve and the outside of inner chuck are equipped with the same axis thread hole one and thread hole two with thread hole three, the same axis thread hole three, thread hole one and thread hole two are fixed bolt screw thread connection between, the utility model passes through the synergistic effect of each component, has realized the non - injury, high - precision clamping of thread, spline etc. Non - smooth surface shaft work piece, has the advantage of strong universality, convenient to dismount simultaneously, low maintenance cost, has extremely high practical value and popularization prospect in lathe precision machining field.

Description

Technical Field

[0001] This utility model relates to the field of machine tool processing technology, and in particular to a heart-shaped chuck for machine tool processing. Background Technology

[0002] The collet chuck is an indispensable accessory for machining shaft-type workpieces. Its core function is to clamp the workpiece and transmit torque, while working with centers to ensure the coaxiality of the workpiece and avoid accuracy errors caused by workpiece misalignment during machining. Existing collets have relatively simple clamping methods (such as...). Figure 1 This type of clamping mechanism typically achieves clamping by directly pressing the workpiece surface with a rotating screw. While it is well-suited for workpieces with smooth cylindrical surfaces, it has significant drawbacks in actual machining. When the clamping part of the shaft workpiece to be machined has a threaded or splined structure, the traditional screw-type clamping method will directly contact the thread profile or spline tooth surface of the workpiece. Since the screw and the workpiece surface have rigid point or line contact, the local pressure generated during the clamping process is relatively large, which can easily cause damage such as thread profile deformation and spline tooth surface scratches, leading to workpiece scrap. Even if it is not directly scrapped, the damaged parts will affect the subsequent assembly accuracy or performance, increasing rework costs. In addition, the clamping structure of traditional chucks is fixed and cannot be flexibly adjusted according to the structure of the workpiece clamping part (such as thread specifications and spline parameters), resulting in poor versatility. Different chucks need to be changed for different workpiece structures, reducing machining efficiency.

[0003] Therefore, existing chucks cannot meet the requirements for damage-free clamping of shaft workpieces with non-smooth surfaces such as threads and splines. There is an urgent need for a new type of chuck that can be adapted to different clamping parts and can avoid workpiece damage. Utility Model Content

[0004] This utility model addresses the shortcomings of existing technologies by providing a chuck for machine tool processing. The specific technical solution is as follows: A chuck for machine tool processing includes a base and a chuck head. The chuck head includes an outer sleeve and an inner chuck. The inner groove of the inner chuck is configured with an internal spline or internal thread adapted to the outside of a shaft. The outer sleeve is connected to the base via a detachable component. The outer side of the inner chuck is inserted into the inner side of the outer sleeve via a limiting component. Multiple fixing strips are arranged circumferentially on the outer side of the outer sleeve. Multiple threaded holes are provided axially on the fixing strips. The inner side of the outer sleeve and the outer side of the inner chuck are respectively provided with threaded holes one and two coaxial with the threaded holes three. The coaxial threaded holes three, threaded holes one and threaded holes two are threadedly connected by fixing bolts.

[0005] Preferably, the limiting member includes multiple limiting strips arranged in an annular array on the outside of the inner clamp, and the inner annular array of the outer sleeve has multiple limiting grooves adapted to the limiting strips. When the limiting strips are fully inserted into the limiting grooves, the second threaded hole coaxially corresponds to the first threaded hole and the third threaded hole.

[0006] Preferably, the base includes a first frame, on which a turntable is mounted. The turntable has a first tip on the side away from the first frame, and a second frame is provided on the side of the turntable away from the first frame. The second frame has a second tip on the side of the second frame that is coaxial with the first tip.

[0007] Preferably, the disassembly components are provided in multiple sets and arranged in a ring on the outside of the outer sleeve. The disassembly components include an L-shaped fixing rod and a fixing block. The L-shaped fixing rod is fixedly connected to the outside of the outer sleeve, and the fixing block is fixedly connected to the side of the turntable near the outer sleeve. The L-shaped fixing rod and the fixing block are fixedly connected by a threaded rod.

[0008] The beneficial effects of this utility model are: 1. Traditional chucks rigidly compress workpieces using a screw, which can easily damage threads and splines. This invention achieves damage-free clamping through a structural adaptation between the inner chuck and the workpiece: the inner side of the inner chuck is designed with internal threads or splines according to the workpiece clamping location, forming a surface contact with the workpiece. This increases the contact area several times compared to traditional point contact, significantly reducing local pressure and preventing damage such as thread deformation and spline scratches. Simultaneously, the threaded or splined fit between the inner chuck and the workpiece has a self-centering effect. Combined with the coaxial positioning of the two centers, this further improves the coaxiality of the workpiece after clamping, reduces machining errors, and effectively lowers the workpiece scrap rate.

[0009] 2. Traditional chuck clamping structures are fixed and only suitable for a single type of workpiece. This invention, however, uses a combination design of an outer chuck and a replaceable inner chuck. By simply replacing the inner chuck with different specifications (such as different thread specifications or spline parameters), it can accommodate workpieces with various non-smooth surfaces, without needing to replace the entire chuck. The limiting components ensure quick positioning and alignment between different inner and outer chucks, and the fit between the fixing bolts and threaded holes ensures connection stability. This shortens the inner chuck replacement time, significantly improving efficiency compared to traditional chuck replacement, and substantially reducing equipment investment costs and processing preparation time.

[0010] 3. Traditional chucks transmit torque via screw compression, which is prone to slippage and affects machining stability. In contrast, the torque transmission path of this invention is "machine spindle → turntable → detachable part → outer sleeve → limiting strip → inner chuck → workpiece". The L-shaped fixing rod and fixing block of the detachable part are tightly connected by a threaded rod, ensuring no relative slippage between the turntable and the outer sleeve. The cooperation between the limiting strip and the limiting groove restricts the relative rotation between the outer sleeve and the inner chuck. The threaded or splined engagement between the inner chuck and the workpiece achieves surface contact torque transmission, eliminating the risk of slippage. Simultaneously, the two centers of the base ensure coaxiality of the workpiece during machining, superior to the error of traditional chucks. Combined with stable torque transmission, this improves the machining accuracy of the workpiece (such as roundness and cylindricity), meeting the requirements of precision machining.

[0011] 4. The threaded rod connection of the detachable parts allows for easy manual disassembly and assembly of the chuck head and turntable without the need for special tools. The inner chuck head is a consumable part (the threads or splines may wear after long-term use), and only the inner chuck head needs to be replaced to restore the chuck head's function. There is no need to replace other parts such as the outer chuck head or base, thus reducing maintenance costs. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the existing chicken heart chuck structure; Figure 2 This is a schematic diagram of the overall structure of this utility model; Figure 3 This is a schematic diagram of the connection structure between the outer jacket and the inner clamp in this utility model; Figure 4 for Figure 3 A magnified structural diagram of point A in the middle.

[0013] Reference numerals in the attached diagram: 1. Frame 1; 100. Shaft; 2. Turntable; 3. Center 1; 4. Outer sleeve; 40. Limiting groove; 41. Threaded hole 1; 5. L-shaped fixing rod; 50. Threaded rod; 51. Fixing block; 6. Frame 2; 7. Center 2; 8. Inner clamp; 80. Threaded hole 2; 81. Limiting strip; 9. Fixing bolt; 90. Threaded hole 3; 91. Fixing strip. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0015] Example For chucks used in machine tool processing, please refer to... Figures 1-4This utility model addresses the shortcomings of existing technologies by providing a heart-shaped chuck for machine tool processing. It aims to achieve damage-free clamping of shaft workpieces with non-smooth surfaces such as threads and splines through the combination structure of "outer chuck 4 + replaceable inner chuck 8". At the same time, it improves the versatility and ease of assembly and disassembly of the chuck, meeting the processing needs of workpieces of different specifications.

[0016] A chuck used in machine tool processing includes a base, a chuck head, detachable parts, and limiting parts. The structure, connection relationship, and function of each component are as follows: Specifically, the base is the mounting and support foundation for the chuck, used to connect the machine tool spindle and cooperate with the center to achieve coaxial positioning of the workpiece, including the support frame 1, turntable 2, center 1 3, support frame 2 6, and center 2 7: The support frame 1 is made of cast iron, which provides good rigidity and stability. It is fixedly mounted on the machine tool worktable to provide fixed support for the turntable 2. The top of the support frame 1 has a circular mounting groove for embedding the bearing assembly of the turntable 2, ensuring that the turntable 2 can rotate flexibly.

[0017] Turntable 2 is a circular metal disc that is connected to the mounting slot of the support 1 via a high-precision bearing. It can rotate at high speed around its own axis. One end is connected to the machine tool spindle via a coupling to transmit the machine tool torque. The other end is used to install the chuck head and the center 3, which is a key intermediate component for transmitting torque to the workpiece.

[0018] Tip 3 is a conical carbide component that is fixed to the center of turntable 2 via a threaded connection or interference fit, with its axis coinciding with the axis of turntable 2. The tip of tip 3 is used to press against the center hole at one end of the workpiece, achieving axial positioning and radial limiting of the workpiece, ensuring that the workpiece has no radial offset when rotating synchronously with turntable 2.

[0019] The support frame 2 6 is similar in structure to the support frame 1, and is symmetrically arranged on the side of the turntable 2 away from the support frame 1, and is also fixed to the machine tool worktable. The position of the support frame 2 6 can be adjusted along the axis of the workpiece to accommodate shaft-type workpieces of different lengths.

[0020] Center 2 (7) has the same structure and collinear axis as Center 1 (3). It is installed at the center of the side of the support 2 (6) near the turntable 2, and its tip is used to press against the center hole at the other end of the workpiece. Through the synergistic action of Center 1 (3) and Center 2 (7), the workpiece can be stably supported between the two centers, ensuring the coaxiality of the workpiece and providing a foundation for high-precision machining.

[0021] Specifically, the chuck head is the core component that directly clamps the workpiece. It adopts a combination design of "outer chuck 4 + inner chuck 8". The inner chuck 8 can be replaced according to the structure of the workpiece clamping part. The chuck head includes the outer chuck 4 and the inner chuck 8. The outer sleeve 4 is a cylindrical metal sleeve made of 45# steel with heat treatment, which has high strength and wear resistance. One end of the outer sleeve 4 is fixedly connected to the turntable 2 through a detachable part and rotates synchronously with the turntable 2; the inner side is provided with an annular cavity to accommodate the inner clamp 8; the outer side has 3-4 fixing strips (preferably 3, forming a triangular stable structure) evenly arranged in a circumferential direction, the fixing strips extend along the axial direction of the outer sleeve 4, and each fixing strip has 2-3 threaded holes 90 evenly opened in a axial direction for connecting the inner clamp 8 through fixing bolts 9; the inner sidewall of the outer sleeve 4 also has multiple limiting grooves 40 evenly arranged in a circumferential direction, which cooperate with the limiting strips 81 of the inner clamp 8 to achieve circumferential positioning.

[0022] The inner chuck 8 is a cylindrical sleeve structure made of the same material as the outer sleeve 4. Its inner diameter is designed according to the structure of the workpiece clamping part. When the workpiece clamping part is threaded, the inner groove of the inner chuck 8 is machined to match the workpiece thread specification; when the workpiece clamping part is splined, the inner groove is machined to match the spline parameters of the workpiece. Multiple limiting strips 81 are evenly arranged circumferentially on the outer wall of the inner chuck 8 (the number is the same as the limiting grooves 40 of the outer sleeve 4), and a second threaded hole 80 is provided on the outer wall corresponding to the position of the first threaded hole 41 of the outer sleeve 4. The core function of the inner chuck 8 is to form a surface contact fit with the workpiece clamping part through the inner thread or internal spline on its inner side, avoiding workpiece damage caused by traditional rigid point contact. Furthermore, by replacing the inner chuck 8 with different specifications, it can adapt to workpieces with different thread or spline parameters, improving the versatility of the chuck.

[0023] Specifically, the detachable parts are used to enable quick connection and disassembly between the outer sleeve 4 and the turntable 2. There are 2-4 sets of these parts, which are evenly distributed along the outer circumference of the outer sleeve 4 (staggered from the fixing strip). They include L-shaped fixing rods 5, fixing blocks 51, and threaded rods 50. The L-shaped fixing rods 5 are metal bending parts. One end is fixed to the outer wall of the outer sleeve 4 by welding or bolting, and the other end extends in a direction perpendicular to the axis of the outer sleeve 4. The extended end has a through hole that matches the threaded rod 50.

[0024] The fixing block 51 is a metal block that is fixed to the turntable 2 on the side near the outer sleeve 4 by welding. An internal threaded hole is provided at the position corresponding to the extension end of the L-shaped fixing rod 5.

[0025] The threaded rod 50 is a high-strength bolt that passes through the through hole of the L-shaped fixing rod 5 and is threaded into the internal threaded hole of the fixing block 51. Tightening the threaded rod 50 can tightly fix the L-shaped fixing rod 5 and the fixing block 51, thereby connecting the outer sleeve 4 and the turntable 2. Loosening the threaded rod 50 allows the outer sleeve 4 to be removed, facilitating the replacement of the inner clamp 8 or maintenance. The detachable design reduces the assembly and disassembly time between the outer sleeve 4 and the turntable 2 to 1 / 3 of that of traditional bolted connections, significantly improving operational efficiency.

[0026] Specifically, the limiting components are used to achieve circumferential positioning of the inner clamp 8 and the outer clamp 4, ensuring precise alignment of their threaded holes, including the limiting strip 81 and the limiting groove 40: Specifically, the limiting strip 81 is a rectangular metal strip that is evenly distributed circumferentially along the outer side wall of the inner clamp 8 (usually 3-4 strips). It is integrally formed or welded to the inner clamp 8, and its width and height are adapted to the limiting groove 40 of the outer sleeve 4.

[0027] Specifically, the limiting groove 40 is a rectangular groove, which is opened on the inner side wall of the outer sleeve 4. The number of grooves is the same as that of the limiting strip 81, and the position corresponds one-to-one with the limiting strip 81.

[0028] When the inner chuck 8 is inserted into the inner cavity of the outer sleeve 4, the limiting strip 81 can be inserted axially along the limiting groove 40. On the one hand, it restricts the relative rotation between the inner chuck 8 and the outer sleeve 4, ensuring that the torque can be stably transmitted through the path of outer sleeve 4 → limiting strip 81 → inner chuck 8 → workpiece. On the other hand, when the limiting strip 81 is fully inserted into the limiting groove 40, the threaded hole 80 of the inner chuck 8 is precisely coaxially aligned with the threaded hole 41 of the outer sleeve 4 and the threaded hole 90 of the fixing strip, so that the fixing bolt 9 can be installed without additional adjustment, thus improving assembly efficiency.

[0029] Specifically, the fixing bolts 9 are high-strength internal hexagon bolts, and the number is the same as that of the threaded holes 3 90. They are used to connect the fixing strip, the outer sleeve 4, and the inner collet 8. After the limiting strip 81 of the inner collet 8 is fully inserted into the limiting groove 40 of the outer sleeve 4, the fixing bolts 9 pass through the threaded holes 3 90 of the fixing strip and the threaded holes 1 41 of the outer sleeve 4 in sequence, and finally connect with the threaded holes 2 80 of the inner collet 8. By tightening the fixing bolts 9, the three can be tightly fixed into one, avoiding relative displacement between the inner collet 8 and the outer sleeve 4 during processing and ensuring clamping stability.

[0030] This embodiment takes the processing of a long shaft workpiece with an M20 thread in the clamping part as an example to explain in detail the assembly and use process of the heart-shaped chuck. The inner chuck 8 is selected with an M20 internal thread on the inner side. Three sets of limiting strips 81 and limiting grooves 40 are set, and three sets of fixing strips are set. Each set of fixing strips has two threaded holes 90.

[0031] Assembly process of the chuck 1. Base installation: Fix the first base 1 and the second base 6 on the machine tool worktable respectively, adjust their positions to ensure that the axis of the first center 3 (installed in the center of the turntable 2) and the second center 7 (installed in the center of the second base 6) are collinear; install the turntable 2 in the mounting slot of the first base 1 through the bearing, and connect the turntable 2 to the machine tool spindle through the coupling.

[0032] 2. Assembly of inner collet 8 and outer collet 4: Select an inner collet 8 with an M20 internal thread on the inside. Align the limiting strip 81 of the inner collet 8 with the limiting groove 40 on the inside of the outer collet 4. Push the inner collet 8 into the inner cavity of the outer collet 4 axially until the limiting strip 81 is fully inserted into the limiting groove 40 (at this time, the second threaded hole 80 of the inner collet 8 is coaxially aligned with the first threaded hole 41 of the outer collet 4 and the third threaded hole 90 of the fixing strip). Pass the fixing bolt 9 through the third threaded hole 90 and the first threaded hole 41 in sequence, and tighten it with the second threaded hole 80 to complete the fixing of the inner collet 8 and the outer collet 4.

[0033] 3. Connect the clamp head to the turntable 2: Place the assembled "outer jacket 4 + inner clamp head 8" assembly close to the turntable 2, aligning the extended end of the L-shaped fixing rod 5 on the outer jacket 4 with the fixing block 51 on the turntable 2; pass the threaded rod 50 through the through hole of the L-shaped fixing rod 5 and tighten it with the internal threaded hole of the fixing block 51 until the outer jacket 4 and the turntable 2 are tightly fitted, thus completing the installation of the clamp head.

[0034] 2. Workpiece clamping and machining process 1. Workpiece positioning: Align the center hole of one end of the long shaft workpiece to be processed with the tip of the center 3, push the support 6 to move along the axis of the workpiece, so that the tip of the center 7 presses against the center hole of the other end of the workpiece, and achieve coaxial positioning of the workpiece through the two centers.

[0035] 2. Workpiece clamping: Rotate the workpiece so that the M20 external thread of the workpiece clamping part is aligned with the M20 internal thread of the inner chuck 8. Slowly screw the workpiece in until the workpiece thread is fully engaged with the thread of the inner chuck 8 (the engagement length is not less than 2 thread pitches to ensure stable torque transmission). At this time, the inner chuck 8 forms a surface contact with the workpiece through the internal thread, without local pressure concentration, thus avoiding damage to the workpiece thread.

[0036] 3. Start-up: Start the machine tool. The machine tool spindle drives the turntable 2 to rotate. The turntable 2 drives the outer sleeve 4 to rotate through the detachable parts. The outer sleeve 4 drives the inner chuck 8 to rotate through the limit bar 81. The inner chuck 8 drives the workpiece to rotate synchronously through the threaded engagement. At the same time, the machine tool tool processes the workpiece according to the preset program (such as external cylindrical grinding). During the processing, the two centers always ensure the coaxiality of the workpiece, and the chuck stably transmits torque without workpiece deviation or damage.

[0037] 3. Replacement process of inner collet 8 When machining a workpiece whose clamping part is splined, the steps for changing the inner chuck 8 are as follows: 1. Turn off the machine tool, loosen the support frame 2 6, take out the processed workpiece, loosen all the fixing bolts 9, and take out the fixing bolts 9 from the threaded hole 3 90, threaded hole 1 41, and threaded hole 2 80; pull the inner chuck 8 axially so that the limiting strip 81 of the inner chuck 8 comes out of the limiting groove 40 of the outer sleeve 4, and take out the old inner chuck 8.

[0038] 2. Select a new inner collet 8 with the corresponding spline specification on the inside, align its limiting strip 81 with the limiting groove 40 of the outer sleeve 4 and insert it until the limiting strip 81 is fully in place; install and tighten the fixing bolts 9 to complete the assembly of the new inner collet 8 and the outer sleeve 4, and then the workpiece of the spline clamping part can be processed, saving time and effort.

[0039] In summary, this utility model achieves damage-free, high-precision clamping of non-smooth surface shaft workpieces such as threads and splines through the synergistic effect of its components. It also has the advantages of strong versatility, convenient disassembly and assembly, and low maintenance costs, and has extremely high practical value and promotion prospects in the field of precision machining.

[0040] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A chuck for machine tool processing, characterized in that, The device includes a base and a clamping head. The clamping head includes an outer sleeve (4) and an inner clamp (8). The inner groove of the inner clamp (8) is configured as an internal spline or internal thread that is adapted to the outside of the shaft (100). The outer sleeve (4) is connected to the base through a detachable part. The outer side of the inner clamp (8) is inserted into the inner side of the outer sleeve (4) through a limiting part. The outer side of the outer sleeve (4) has multiple fixing strips (91) arranged circumferentially. The fixing strips (91) have multiple threaded holes three (90) axially. The inner side of the outer sleeve (4) and the outer side of the inner clamp (8) are respectively provided with threaded holes one (41) and two (80) coaxial with the threaded holes three (90). The coaxial threaded holes three (90), threaded holes one (41) and threaded holes two (80) are connected by a fixing bolt (9).

2. The chuck for machine tool processing according to claim 1, characterized in that: The limiting component includes multiple limiting strips (81) arranged in a ring array on the outside of the inner clamp (8). The inner ring array of the outer sleeve (4) has multiple limiting grooves (40) that are adapted to the limiting strips (81). When the limiting strips (81) are fully inserted into the limiting grooves (40), the threaded hole two (80) is coaxially corresponding to the threaded hole one (41) and the threaded hole three (90).

3. The chuck for machine tool processing according to claim 2, characterized in that: The base includes a frame one (1), on which a turntable (2) is mounted. The turntable (2) has a tip one (3) on the side away from the frame one (1). The turntable (2) has a frame two (6) on the side away from the frame one (1). The frame two (6) has a tip two (7) on the side close to the frame one (1) with the same axis as the tip one (3).

4. The chuck for machine tool processing according to claim 3, characterized in that: The disassembly components are provided in multiple sets and are arranged in a ring on the outside of the outer sleeve (4). The disassembly components include an L-shaped fixing rod (5) and a fixing block (51). The L-shaped fixing rod (5) is fixedly connected to the outside of the outer sleeve (4), and the fixing block (51) is fixedly connected to the turntable (2) on the side close to the outer sleeve (4). The L-shaped fixing rod (5) and the fixing block (51) are fixedly connected to each other by a threaded rod (50).

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