An ultra-long internal broach for large-length-diameter-ratio internal hole profile broaching

Abstract

The application discloses a super-long internal broach for long-ratio inner hole profile broaching, which comprises a broach bar, a broach disc, a broach handle and a broach holder. The broach disc is detachably arranged on the broach handle. One end of the broach holder is detachably arranged on the broach handle and is positioned and connected with the broach disc. The other end of the broach holder is detachably connected with one end of the broach bar. The other side of the broach bar is detachably arranged on a machine tool. The application solves the problems of single broach manufacturing difficulty, multi-broach tool changing inconvenience, high manufacturing cost and high labor intensity when the conventional internal broach is used to broach a large aperture and a long-ratio hole with a ratio greater than 5 times. When the aperture is greater than 100 mm and the long-ratio is greater than 25 times, the application solves the bottleneck problem of being unable to manufacture. The broaching part and the non-broaching part are separated. The working part and the non-working part are clamped and loosened by hydraulic pressure. There is no pipeline winding, and the disassembly and assembly are convenient, and the labor intensity of workers is low.

Description

Technical Field

[0001] This invention relates to the field of cutting tool technology, specifically to an ultra-long internal broaching tool for broaching internal bore profiles with a large length-to-diameter ratio. Background Technology

[0002] Internal broaches are used to machine various internal hole profiles (internal hole profiles, i.e., internal holes, grooves, keyways, splines, spiral grooves, etc. on internal holes). They are usually composed of an integrated broaching part and a non-broaching part. The broaching part includes cutting teeth and alignment teeth, while the non-broaching part usually includes six parts: shank, neck, transition taper, front guide, rear guide, and rear support or rear shank. The maximum length of a standard broach is usually 1700mm, while the maximum length of a customized broach can reach 2000mm, and the length of an extra-large broach can reach 3000mm. When broaching large-diameter through holes with an aspect ratio greater than 5, it is difficult to manufacture a single broach, and it is inconvenient to change tools between multiple broaches. This results in high manufacturing costs and high manual labor intensity. When the hole diameter is greater than 100mm and the aspect ratio is greater than 25, the conventional internal broach structure has a bottleneck in manufacturing due to the excessive length of the broach. Generally, an aspect ratio greater than 20 is considered a large aspect ratio. This invention addresses the existing technical problems by providing an ultra-long internal broach for broaching internal bore surfaces with large length-to-diameter ratios. It adopts a structure in which the broaching part and the non-broaching part are separated, and the working part is clamped and released by hydraulic pressure. There is no pipe entanglement, and the assembly and disassembly are convenient, reducing the labor intensity of workers. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an ultra-long internal broach for broaching internal bore surfaces with large length-to-diameter ratio, in light of the current state of the technology.

[0004] The technical solution of this invention is as follows: An ultra-long internal broach for broaching internal bore surfaces with a large length-to-diameter ratio includes a tool shank, a tool head, a broach holder, and a tool clip. The tool head is detachably mounted on the broach holder. One end of the tool clip is detachably mounted on the broach holder and positioned and connected to the tool head. The other end of the tool clip is detachably connected to one end of the tool shank. The other side of the tool shank is detachably mounted on a machine tool.

[0005] Furthermore, the drawbar includes a drawbar spindle and a hydraulic quick-release assembly A disposed inside the drawbar spindle; the hydraulic quick-release assembly A includes a drawbar cylinder, a piston, a compression spring, and a push rod; one end of the drawbar spindle is provided with an oil circuit quick-change connector, and the inside of the drawbar spindle is provided with an oil groove for communication between the oil circuit quick-change connector and the oil chamber inside the drawbar cylinder; the compression spring is disposed on the piston, and the piston end is provided with a cone, which cooperates with the push rod to realize the radial movement of the push rod, thereby realizing the detachable installation of the cutter head.

[0006] Furthermore, a guide sleeve is coaxially provided on the outside of the tool holder mandrel. The guide sleeve is fixedly installed on the tool holder mandrel by nut A and is used for guiding the inner hole when broaching the workpiece to ensure machining accuracy.

[0007] Furthermore, the tool holder and the tool shank are connected by a bidirectional nut, and the torque generated during the broaching process is transmitted through a force transmission key transition fit.

[0008] Furthermore, the tool holder has a hollow internal structure with a length that matches the broaching length of the workpiece. One side of the tool holder has multiple square groove structures distributed circumferentially for force transmission key transition fit, forming a torque transmission effect. In addition, it is also provided with external threads for connection with a bidirectional nut. The other side of the tool holder has a flange structure for mounting on the machine tool.

[0009] Furthermore, the tool holder includes a tool holder spindle and a hydraulic quick-release assembly B disposed inside the tool holder spindle; the hydraulic quick-release assembly B includes a tool holder cylinder, a sliding sleeve, and a locking block; the tool holder cylinder is provided with a piston rod, and multiple shift forks are provided circumferentially on the outer side of the piston rod; the tool holder spindle is provided with multiple U-shaped grooves circumferentially, and the sliding sleeve is provided with multiple pin holes evenly distributed circumferentially, the shift forks passing through the U-shaped grooves and cooperating with the pin holes; the outer wall of the end of the tool holder spindle near the pull handle is provided with multiple square grooves evenly distributed circumferentially, the locking block is fitted in the square grooves, the sliding sleeve is slidably installed on the outer wall surface of the tool holder spindle, and the sliding sleeve and the locking block cooperate to realize the radial movement of the locking block, thereby realizing the detachable installation of the pull handle.

[0010] Furthermore, the cylinder of the tool holder cylinder is provided with a threaded hole A and a threaded hole B for quick-change oil circuit connectors, which are used for the installation of quick-change oil circuit connectors A and B, respectively. A large-cavity oil circuit and a small-cavity oil circuit are respectively provided below it, one for unloading oil and the other for inlet oil.

[0011] Furthermore, a dust cover is provided on the outer wall of the tool holder mandrel to prevent dirt from entering the space formed by the tool holder mandrel and the sliding sleeve during broaching, thus ensuring that the sliding sleeve slides freely.

[0012] Furthermore, a positioning boss is provided at one end of the tool holder mandrel, and the positioning boss is positioned and connected to the corresponding groove of the tool disc; a guide sleeve is coaxially provided on the tool holder mandrel, and is fixedly installed by nut B. The guide sleeve is used for rear guidance of the workpiece, and its length can be determined according to the required guidance length of the workpiece to ensure machining accuracy.

[0013] Furthermore, the tool holder spindle has multiple square groove structures evenly distributed circumferentially at one end near the tool bar for fixing and installing the force transmission key, and the positioning structure at the end of the tool holder spindle cooperates with the hollow structure of the tool bar.

[0014] The beneficial effects of this invention are as follows: An ultra-long internal broach for broaching internal bore surfaces with large length-to-diameter ratios solves the bottlenecks of conventional internal broaches when broaching large-diameter through holes with a length-to-diameter ratio greater than 5. These bottlenecks include the difficulty in manufacturing a single broach, the inconvenience of changing multiple broaches, high manufacturing costs, high labor intensity, and the inability to manufacture when the hole diameter is greater than 100mm and the length-to-diameter ratio is greater than 25. The broaching and non-broaching parts are separated by a hydraulic clamping and releasing mechanism, eliminating pipe entanglement, facilitating disassembly and assembly, reducing labor intensity for workers, and overcoming the manufacturing bottleneck. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the broach handle portion of the present invention; Figure 3 This is a schematic diagram of the tool holder structure of the present invention; Figure 4 This is a schematic diagram of the tool holder. Figure 5 Schematic diagram of the tool holder mandrel; Figure 6 This is a schematic diagram of the internal structure of the quick-connect coupling in the oil circuit. Figure 7 This is a schematic diagram of a tool holder cylinder. Figure 8 This is a schematic diagram of the sliding sleeve; Figure 9 This is a magnified view of a compression spring. Figure 10 This is a schematic diagram of the fit between the cone and the push rod; In the diagram: 1. Tool head; 11. Tooth profile; 2. Broach holder; 21. Tool holder spindle; 211. Oil groove; 212. Slot; 22. Tool holder cylinder; 221. Compression spring; 222. Cone; 223. Large cylinder chamber; 224. Piston; 23. Quick-connect hydraulic connector; 24. Push rod; 25. Guide sleeve A; 26. Nut A; 3. Tool holder; 31. Hollow structure; 32. Square groove structure; 33. External thread; 34. Flange structure; 4. Tool holder; 41. Tool holder spindle; 411. Radially distributed square groove structure; 412. Positioning structure; 413. External thread; 414. Threaded hole of quick-change oil circuit connector; 415. U-shaped groove; 416. Square groove; 417. Positioning boss; 42. Nut B; 43. Guide sleeve B; 441. Quick-change oil circuit connector A; 442. Quick-change oil circuit connector B; 45. Tool holder cylinder; 451. Cylinder barrel; 4511. Oil inlet passage; 4512. Oil return passage; 452. Piston; 453. Piston rod; 454. Shift fork; 455. Bushing; 46. Sliding sleeve; 461. Annular groove; 462. Pin hole; 47. Dust cover; 48. Clamping block; 5. Two-way nut; 6. Force transmission key. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0017] An ultra-long internal broach for broaching internal bore surfaces with a large length-to-diameter ratio includes a working part (tool head 1), a non-working part (tool shank 3), a broach handle 2, a tool clip 4, a two-way nut 5, and a force transmission key 6.

[0018] The tooth profile of the cutter head 1 is determined according to the shape of the inner hole surface of the workpiece to be broached, and it consists of multiple sets to complete the broaching amount.

[0019] The tool holder 3 is a hollow rod with a length that matches the broaching length of the workpiece. The front end is equipped with a circumferentially distributed square groove structure 32 and an external thread 33, and the rear end has a flange structure 34 that can be mounted on the machine tool.

[0020] The drawbar handle 2 includes a nut A26, a guide sleeve A, and a tool holder spindle 21. The guide sleeve A and the tool holder spindle 21 are coaxially arranged and locked with the nut A26. A tool holder cylinder 22 is fixedly installed inside the tool holder spindle 21 of the drawbar handle 2. The piston 224 (piston rod) of the tool holder cylinder 22 is connected to a cone 222. The cone 222 has a sliding groove, and evenly distributed push rods 24 are installed at the sliding groove. A compression spring 221 is installed inside the tool holder cylinder 22 inside the tool holder spindle 21. The compression spring 221 is installed on the piston 224. The function of the compression spring 221 is to enable the piston 224 to return to its original position. Specifically, the compression spring 221 is sleeved on the guide post at the center of the tool holder cylinder. The guide post is fixed inside the cylinder. One end of the compression spring 221 abuts against the top limit part of the guide post, and the other end abuts against the piston 224. The tool holder spindle 21 is provided with an oil groove 211, which is connected to the large cylinder chamber 223 of the tool holder oil cylinder (one end of the oil groove 211 is provided with an oil circuit quick-change connector 23, which is connected to the external oil circuit and used when disassembling and assembling the tool disc 1). The tool holder spindle 21 is installed in conjunction with the tool disc 1, and the top of the evenly distributed push rods 24 is slidably connected to the tool disc 1.

[0021] The tool holder 4 includes a guide sleeve B43, a nut B42, a tool holder spindle 41, a sliding sleeve 46, a locking block 48, a quick-change oil circuit connector A441, a quick-change oil circuit connector B442, a tool holder cylinder 45, and a dust cover 47. The guide sleeve B43 is coaxially arranged with the tool holder spindle 41 and is locked with the nut B42. The sliding sleeve 46 is coaxially slidably connected to the tool holder spindle 41.

[0022] The sliding sleeve 46 has an annular groove 461 inside. The locking block 48 is slidably installed on the circumference of the tool holder spindle 41 and can cooperate with the annular groove 461 of the sliding sleeve (the locking block 48 is an elastic element that can automatically return to radial position). The tool holder spindle 41 of the tool holder has a tool holder cylinder 45 inside. The piston rod 453 of the tool holder cylinder 45 inside the tool holder spindle 41 is connected to a radially distributed shift fork 454. The end of the shift fork 454 is fitted with a bushing 455. The sliding sleeve 46 of the tool holder has evenly distributed pin holes 462. The bushing 455 at the end of the shift fork 454 slides with the sliding sleeve 46. The bushing 455 is fitted on the pin hole 462. One end of the tool holder spindle 41 is provided with a protruding positioning key, i.e., a positioning boss 417. The other end is provided with an external thread 413 and a positioning cone or positioning cylinder. The circumferentially distributed square groove 416, U-shaped groove 415, and oil circuit quick-change connector threaded hole 414 are provided.

[0023] The tool holder 3 is coaxially and fixedly connected to the tool clip 4 via the bidirectional nut 5. The force transmission key 6 is fixedly installed on the tool clip spindle 41 and cooperates with the square groove structure 32 distributed circumferentially on the tool holder.

[0024] The tool holder spindle 21 in the tool holder 2 passes through the inner hole of the tool holder spindle in the tool holder, and the tool holder 2 is fixed or released by the radial movement of the locking block 48. Example

[0025] like Figure 1-10 As shown, this invention is an ultra-long internal broach for broaching internal bore surfaces with a large length-to-diameter ratio, comprising: a cutter head 1, a broach shank 2, a tool holder 3, a tool clip 4, a double-acting nut 5, and a force transmission key 6. The cutter head 1 is mounted on the broach shank 2 for quick replacement. The broach shank 2 is mounted on the tool clip 4, which is fixed to the tool holder 3 by the double-acting nut 5. The force transmission key 6 is fixed to the tool clip 4 and has a transition fit with the tool holder 3 to transmit the torque generated during the broaching process.

[0026] In the broaching shank 2, the main body of the shank spindle 21 is equipped with an oil groove 211. When the cutter head 2 needs to be replaced, the quick-change oil supply connector 23 is opened by external force to release oil. The compression spring 221 pushes the piston 224 to the left, causing the cone 222 to move to the left and the push rod 24 to move inward, releasing the cutter head 2. The cutter head 2 can then slide axially along the shank spindle 21. When the cutter head needs to be clamped, the quick-change oil supply connector 23 is opened by external force to allow oil to enter, overcoming the force of the compression spring 221, pushing the piston 224 to the right, causing the cone 222 to move to the right and the push rod 24 to move outward, clamping the cutter head 2. The guide sleeve is fixedly installed on the shank spindle 21 by a nut 26, used for guiding the inner hole during broaching of the workpiece to ensure machining accuracy.

[0027] The tool holder 3 is a hollow structure 31 with a large length-to-diameter ratio. Its length matches the broaching length of the workpiece. A radially distributed square groove structure 32 is arranged on one side for the transition fit of the force key 6 to form a torque transmission function. In addition, an external thread 33 is provided for connection with the bidirectional nut 5 to connect the tool holder 4 and the tool holder 3 into one unit. The other side of the tool holder 3 has a flange structure 34 for mounting on the machine tool.

[0028] The tool holder 4 consists of a tool holder spindle 41, a nut 42, a guide sleeve 43, a quick-change hydraulic connector A441, a quick-change hydraulic connector B442, a tool holder cylinder 45, a sliding sleeve 46, and a dust cover 47. The guide sleeve 43, fixedly mounted to the outer cylindrical surface of the tool holder spindle 41 by the nut B42, serves as the rear guide for the workpiece; its length can be determined based on the required guide length to ensure machining accuracy. The tool holder cylinder 45 is fixedly mounted inside the tool holder spindle 41. The sliding sleeve 46 is slidably mounted on the tool holder spindle 41 and its outer cylindrical surface. A locking block 48 is installed on the radially evenly distributed square grooves 416 of the spindle 41. The dust cover 47 is fixedly mounted on the shoulder of the outer cylindrical surface of the tool holder spindle 41 to prevent contaminants from entering the space formed by the tool holder spindle 41 and the sliding sleeve 46 during broaching, ensuring the smooth sliding of the sliding sleeve 46.

[0029] The main body of the tool holder spindle 41 has radially distributed square groove structures 411 for fixing and installing the force transmission key 6. A positioning structure 412 mates with the hollow structure of the tool holder 3, and a double-ended nut 5 connects the external threads 413 and 33, linking the tool holder part 4 and the tool holder 3 into one unit. The threaded holes A4141 and B4142 of the oil circuit quick-change connector are used for installing the oil-to-oil quick-change connector A441 and the oil-to-oil quick-change connector B442, respectively. Below these are a large-cavity oil passage 4143 and a small-cavity oil passage 4144, one for unloading oil and the other for inlet oil.

[0030] The tool holder spindle 41 is also provided with radially distributed U-shaped grooves 416, four in this example, for the sleeves 455 on the radially arranged shift forks 454 of the tool holder cylinder 45 to pass through. A positioning boss 417 is provided at the other end of the tool holder spindle 41. The positioning boss 417 is positioned with the corresponding groove of the tool disc 1. Two symmetrical bosses are provided in this example, and they transmit torque.

[0031] The cylinder 451 of the tool holder cylinder 45 has a large-cavity oil passage 4512 and a small-cavity oil passage 4511. When oil enters the large-cavity oil passage 4512 and oil exits the small-cavity oil passage 4511, it pushes the piston rod 453 to the right, causing the shift fork 451 and bushing 455 to move to the right. The bushing 455 passes through the radially evenly distributed pin holes 462 on the sliding sleeve 46, thereby causing the sliding sleeve 46 to move to the right, causing the locking block 48 to move radially outward, separating the tool holder 2 from the tool holder 4; if the tool holder 2... When the shank spindle 21 passes through the inner hole of the tool holder spindle 41, the locking block 48 needs to be engaged in the slot 212 of the shank spindle 21. Then, the large cavity oil passage 4512 discharges oil and the small cavity oil passage 4511 receives oil, pushing the piston rod 453 to the left, which in turn drives the shift fork 451 and bushing 455 to the left. The bushing 455 passes through the radially evenly distributed pin holes 462 on the sliding sleeve 46, thereby driving the sliding sleeve 46 to the left and the locking block 48 to move radially inward, thus completing the connection between the pull handle part 2 and the tool holder 4.

[0032] The work process is as follows: Oil is supplied through quick-change connector 441, allowing oil to flow into the rod chamber of the tool holder cylinder 45. This pushes piston 452 to the right, causing shift fork 454 and bushing 455 to move to the right, which in turn causes sliding sleeve 46 to move to the right. The locking block 48 returns to the empty slot of sliding sleeve 46 and disengages from locking slot 212. Manual or robotic arm moves the drawbar 2 and tool disc 1 away. Tool bar 3 and tool holder 4 return under power drive. Simultaneously, quick-change connector 23 on drawbar 2 connects the oil circuit and drains oil, piston 224 returns to its original position, and tool disc 1 can be separated from drawbar 2 for replacement with another tool disc. After replacement, quick-change connector 23 connects the oil circuit to supply oil, overcoming spring force. Piston 224 moves to the right, pushing cone 222 to the right, causing push rod 24 to move radially and clamp the new tool disc. When the tool holder 3 and tool clip 4 return to their positions, the manual or robotic arm inserts the pull handle 2 and the tool disc 1 into the hole of the tool clip spindle 41 of the tool clip part 4, where the positioning boss engages. Oil is supplied through the quick-change connector 442, and the oil flows into the rodless chamber of the tool clip cylinder 45, thereby pushing the piston 452 to the left, which in turn drives the shift fork 454 and bushing 455 to the left, causing the sliding sleeve 46 to move to the left. The locking block 48 leaves the empty slot of the sliding sleeve 46 and engages with the locking slot 212 of the tool holder spindle 21. The pull handle 21 clamps, and the tool disc 1, pull handle 2, tool holder 3, and tool clip 4 perform broaching under the drive of the power source. This process is repeated multiple times until the inner hole broaching is completed.

[0033] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. An ultra-long internal broach for broaching internal bore profiles with a large length-to-diameter ratio, characterized in that, The tool includes a cutter head (1), a drawbar (2), a tool bar (3), and a tool holder (4). The cutter head (1) is detachably mounted on the drawbar (2). One end of the tool holder (4) is detachably mounted on the drawbar (2) and positioned to be connected to the cutter head (1). The other end of the tool holder (4) is detachably connected to one end of the tool bar (3). The other side of the tool bar (3) is detachably mounted on the machine tool.

2. The ultra-long internal broaching tool for broaching large aspect ratio internal bore surfaces according to claim 1, characterized in that, The pull handle (2) includes a handle spindle (21) and a hydraulic quick-release assembly A disposed inside the handle spindle (21). The hydraulic quick-release assembly A includes a handle cylinder (22), a piston (224), a compression spring (221), and a push rod (24). One end of the handle spindle (21) is provided with an oil circuit quick-change connector (23), and the handle spindle (21) is provided with an oil groove (211) for communication between the oil circuit quick-change connector (23) and the oil chamber (223) inside the handle cylinder (22). The compression spring (221) is disposed on the piston (224), and the end of the piston (224) is provided with a cone (222). The cone (222) cooperates with the push rod (24) to realize the radial movement of the push rod (24), thereby realizing the detachable installation of the cutter head.

3. The ultra-long internal broaching tool for broaching internal bore profiles with a large length-to-diameter ratio according to claim 2, characterized in that, The tool holder spindle (21) is coaxially provided with a guide sleeve (25), which is fixedly installed on the tool holder spindle (21) by a nut A (26) and is used for front guidance of the inner hole when broaching the workpiece to ensure machining accuracy.

4. The ultra-long internal broaching tool for broaching large aspect ratio internal bore surfaces according to claim 1, characterized in that, The tool holder (4) and the tool bar (3) are connected by a two-way nut (5) and the torque generated during the broaching process is transmitted through a force key (6).

5. The ultra-long internal broaching tool for broaching internal bore profiles with a large length-to-diameter ratio according to claim 1, characterized in that, The tool holder (3) has a hollow structure (31) inside, and its length matches the broaching length of the workpiece. On one side of the tool holder (3), there are multiple square groove structures (32) distributed along the circumference, which are used for the transition fit of the force key (6) to form a torque transmission effect. In addition, there is an external thread (33) for connecting with the double-ended nut (5). On the other side of the tool holder (3), there is a flange structure (34) that is installed on the machine tool.

6. The ultra-long internal broaching tool for broaching large aspect ratio internal bore surfaces according to claim 1, characterized in that, The tool holder (4) includes a tool holder spindle (41) and a hydraulic quick-release assembly B disposed inside the tool holder spindle (41); the hydraulic quick-release assembly B includes a tool holder cylinder (45), a sliding sleeve (46), and a locking block (48); the tool holder cylinder (45) is provided with a piston rod (453), and multiple shift forks (454) are provided circumferentially on the outer side of the piston rod (453); the tool holder spindle (41) is provided with multiple U-shaped grooves (415) circumferentially on the upper side, and multiple pin holes (46) are evenly distributed circumferentially on the upper side of the sliding sleeve (46). 2) The shift fork (454) passes through the U-shaped groove (415) and engages with the pin hole (462); the outer wall of the cutter clip spindle (41) near the end of the pull handle (2) is evenly distributed with multiple square grooves (416) along the circumference; the locking block (48) is engaged in the square groove (416); the sliding sleeve (46) is slidably installed on the outer wall of the cutter clip spindle (41); and the sliding sleeve (46) engages with the locking block (48) to realize the radial movement of the locking block (48), thereby realizing the detachable installation of the pull handle.

7. The ultra-long internal broaching tool for broaching large aspect ratio internal bore surfaces according to claim 6, characterized in that, The cylinder (451) of the knife clamp cylinder (45) is provided with a threaded hole A (4141) and a threaded hole B (4142) for quick-change oil circuit connectors, which are used for the installation of quick-change oil circuit connectors A (441) and B (442) respectively. A large cavity oil circuit (4143) and a small cavity oil circuit (4144) are respectively provided below it, one for unloading oil and the other for inlet oil.

8. The ultra-long internal broaching tool for broaching large aspect ratio internal bore surfaces according to claim 6, characterized in that, The outer wall of the tool holder spindle (41) is provided with a dust cover (47) to prevent dirt from entering the space formed by the tool holder spindle (41) and the sliding sleeve (46) during broaching, and to ensure that the sliding sleeve (46) slides freely.

9. The ultra-long internal broaching tool for broaching large aspect ratio internal bore surfaces according to claim 1, characterized in that, One end of the tool holder spindle (41) is provided with a positioning boss (417), which is positioned and connected to the corresponding groove of the tool disc (1); a guide sleeve (43) is coaxially provided on the tool holder spindle (41), which is fixedly installed by nut B (42). The guide sleeve (43) is used for the rear guidance of the workpiece, and its length can be determined according to the required guide length of the workpiece to ensure the machining accuracy.

10. An ultra-long internal broach for broaching internal bore profiles with a large length-to-diameter ratio, as described in claim 6, is characterized in that... The tool holder spindle (41) has multiple square groove structures (411) evenly distributed circumferentially at one end near the tool bar (3) for fixing and installing the force transmission key (6), and the positioning structure (412) provided at the end of the tool holder spindle (41) cooperates with the hollow structure of the tool bar (3).

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