A spiral guide bar compound adjustable fine boring tool for a bicycle front fork part

Abstract

The present invention discloses a spiral guide bar compound adjustable fine boring tool for bicycle front fork parts. The present invention relates to the technical field of machining, and includes a flange tool shank and a flange boring tool. The flange boring tool includes a flange connection assembly for eliminating spindle runout, a step C fine boring assembly connected to the outer side of the top of the flange boring tool, a guide bar assembly connected to the outer side of the bottom of the flange boring tool, a step A hole fine boring assembly connected to the guide bar assembly, and a step B chamfering assembly connected to the flange boring tool. The advantages of the present invention are as follows: the angular runout of the flange boring tool is adjusted by pushing the angular adjustment top pin against the orientation flange mating surface through the angular runout adjustment screw, and the angular adjustment top pin is prevented from falling off by installing a top pin anti-detachment rubber ring between the flange disc gaps, which is convenient for the flange boring tool and the flange interface of the flange tool shank to cause a large influence on spindle runout, ensuring the stability of the hole diameter and cylindricity. The spiral guide bar straddles the intermittent wide oil groove in the part hole, supports the hole wall, avoids the influence of intermittent cutting tool deflection and vibration, and ensures the stability of the hole wall roughness.

Description

Technical Field

[0001] The present invention relates to the technical field of machining, and particularly to a spiral guide bar compound adjustable fine boring tool for bicycle front fork parts. Background Art

[0002] In the field of bicycle manufacturing, the front fork arm is one of the key components, and the machining of deep-hole thin-wall parts in the front fork arm has always been a difficult problem. When traditional machining tools are used to machine such parts, there are often problems such as low precision and poor stability. With the continuous improvement of the requirements for product quality and performance in the bicycle industry, there is an urgent need for a tool that can efficiently and accurately machine the deep-hole thin-wall parts of bicycle front fork arms. This demand has promoted the research and development of spiral guide bar compound adjustable fine boring tools, which combine advanced spiral guide bar technology and adjustable functions and can better adapt to the machining of parts with different sizes and precision requirements;

[0003] The applicant found through retrieval that the Chinese patent disclosed a "deep-hole reamer", and its publication (announcement) number is "CN113814473A". This patent mainly sets an arc-shaped protrusion adjacent to the main cutting edge at the bottom of the main cutting tool, and during the fine reaming process, the radial force of the deep-hole inner wall on the tool is offset by the arc-shaped protrusion, so as to reduce the vibration of the tool and increase the machining precision. However;

[0004] The Chinese patent also disclosed a "guide bar type compound stepped boring tool and method for machining the bottom hole of a camshaft", and its publication (announcement) number is "CN106825643B". This patent mainly uses a guide bar type compound stepped boring tool with functions of guiding, semi-finishing and finishing to machine the three-stage camshaft bottom hole in the middle of the cylinder block with one tool, with high machining precision. Compared with the original process plan, the machining efficiency is increased by about 50%, and the tool cost is reduced. However, in the actual application process, there are multi-tooth cutting, the cutting resistance causes deformation of thin-wall parts, resulting in unstable hole diameter, and at the same time, the cylindricity is unstable and unqualified; the cutting allowance is large, the chip removal space for multi-tooth and multi-step is insufficient, resulting in chip scratches on the hole wall and unstable roughness and unqualified; it cannot quickly retract the tool with low efficiency, and the retraction of the tool requires the same parameters as the feed; the multi-tooth and multi-step composite integral reamer has a high machining cost;

[0005] The Chinese patent also discloses "a processing method for deep holes", with the publication (announcement) number of "CN102303144A". This patent mainly plays a role of multiple corrections through rough and finish boring. 2. The fine boring tool head specially made according to the product characteristics can achieve the best correction effect and can easily adjust the hole diameter. 3. Using a highly accurate outer hole as a guide to process deep holes to ensure the concentricity requirements. 4. The guide sleeve also plays a supporting role, improving the tool rigidity during processing, eliminating the downward acting force generated by the tool's own weight, thereby improving the processing accuracy. 5. Due to the increased rigidity, the processing efficiency is significantly improved at the same time. However, during actual operation, when rotating and cutting, there will be jumping vibration and abnormal noise when the straight guide bar enters and exits the oil guide groove, resulting in intermittent cutting scratches; if the area of the guide bar is increased to cover the oil guide groove, the contact area between the guide bar and the workpiece is too large, generating a large amount of heat due to friction, with a large shrinkage rate of the hole and unstable hole deformation dimensions. However, in actual use, there is a large tool length-diameter ratio, no guide bar support, and it is easy to deflect the tool, resulting in unqualified cylindricity and machining a flared hole;

[0006] Based on the above disclosed patent, solutions are proposed for the front fork arm. The specific problems include reducing the deformation of the thin-walled hole to ensure that the hole diameter tolerance is within ±0.015 and the cylindricity is within 0.04; reducing the tool deflection amount of the long overhang to ensure qualified hole diameter and cylindricity; under the condition of no internal cooling, reasonably discharging chips to ensure that the hole wall roughness meets Ra0.8 and reducing surface scratches to ensure qualified roughness; eliminating the influence of jumping vibration of the guide oil groove during intermittent cutting to ensure qualified hole diameter, cylindricity and roughness; not being affected by the uneven cutting allowance of 0.1 - 1.2 mm, directly machining in place without causing deformation of the thin-walled hole during cutting, resulting in unqualified hole diameter and cylindricity; the tool diameter is adjustable; eliminating the influence of the spindle runout of the machine tool. For this reason, we propose a spiral guide bar composite adjustable fine boring tool for bicycle front fork parts. Summary of the Invention

[0007] The purpose of the present invention is to provide a spiral guide bar composite adjustable fine boring tool for bicycle front fork parts.

[0008] To solve the problems raised in the above background technology, the present invention provides the following technical solutions: A spiral guide bar composite adjustable fine boring tool for bicycle front fork parts, including a flange tool shank and a flange boring tool. The flange boring tool includes a flange connection assembly for eliminating spindle runout, a step C fine boring assembly connected to the outer side of the top of the flange boring tool, a guide bar assembly connected to the outer side of the bottom of the flange boring tool, a step A hole fine boring assembly connected to the guide bar assembly, and a step B chamfering assembly connected to the flange boring tool;

[0009] The flange connection assembly includes flange connection bolts, radial runout adjustment screws, angular runout adjustment screws, angular adjustment top pins, top pin anti - detachment rubber rings, and positioning mandrels. A positioning groove adapted to the positioning mandrel is provided at the bottom center of the flange tool shank. The top center of the flange boring tool is connected to the bottom of the positioning mandrel. Flange end mass rings are respectively fixedly connected to the outer center of the top of the flange boring tool. Thread grooves adapted to the flange connection bolts are provided at the bottom of the flange end mass rings, and the thread grooves extend to the inner wall of the flange tool shank. Positioning holes adapted to the radial runout adjustment screws are provided on all four sides of the flange tool shank. Limiting grooves adapted to the angular runout adjustment screws are provided at the bottom end of the flange end mass rings. The top surface of the angular runout adjustment screw contacts the angular adjustment top pin, and the top surface of the angular adjustment top pin contacts the bottom periphery of the flange tool shank. Anti - detachment grooves adapted to the top pin anti - detachment rubber rings are provided on the outer side of the angular adjustment top pin, and the angular adjustment top pin is slidably connected to the inner wall of the flange end mass ring.

[0010] As a further solution of the present invention: Arc grooves adapted to the radial runout adjustment screws are provided on the periphery of the positioning mandrel.

[0011] As a further solution of the present invention: The step C finish boring assembly includes a step C finish boring tool holder, a tool holder locking screw, a diamond finishing boring blade, a blade locking screw, a radial adjustment screw, and an axial adjustment screw. A groove adapted to the step C finish boring tool holder is provided on the front of the flange boring tool. Locking holes adapted to the tool holder locking screw are provided on the inner wall of the step C finish boring tool holder, and the locking holes extend to the inner wall of the flange boring tool. A finishing groove adapted to the diamond finishing boring blade is provided on the side of the step C finish boring tool holder. Screw holes adapted to the blade locking screw are provided on the inner wall of the diamond finishing boring tool. Radial grooves adapted to the radial adjustment screws are provided on the back of the step C finish boring tool holder. Axial grooves adapted to the axial adjustment screws are provided on the top of the step C finish boring tool holder.

[0012] As a further solution of the present invention: The front end of the diamond finishing boring blade extends to the outside of the step C finish boring tool holder, and the rear end of the radial adjustment screw contacts the inner wall of the finishing groove.

[0013] As a further solution of the present invention: The guide bar assembly includes guide bar A and a back guide bar. Connection grooves adapted to guide bar A are provided on the outer bottom of the flange boring tool, and the number of guide bar A is five groups. The five groups of guide bar A are vacuum - welded at a helix angle of 30° on the outer bottom of the flange boring tool. The outer side of the back guide bar is detachably installed on the front of the flange boring tool.

[0014] As a further solution of the present invention: the number of the stepped A-hole fine boring assemblies is two groups, and the two groups of stepped A-hole fine boring assemblies are respectively installed on the front surface of the bottom of the flange boring tool and the front surface of the middle position of the flange boring tool. The stepped A-hole fine boring assembly includes a pressing block, a diamond blade, a wedge-shaped pin, a limiting adjustment screw and a double-headed locking screw. Two pressing grooves adapted to the pressing block are provided on the front surface of the flange boring tool. Threaded holes adapted to the double-headed locking screw are provided on the inner walls of both the flange boring tool and the pressing block. The front surface of the pressing block is slidably connected to the back surface of the diamond blade. An inclined surface is provided on the front surface of the wedge-shaped pin, and the inclined surface of the wedge-shaped pin is slidably connected to the top surface of the diamond blade. The other end of the wedge-shaped pin contacts the limiting adjustment screw.

[0015] As a further solution of the present invention: an axis groove is provided on the front surface of the flange boring tool, and a blade positioning pin is detachably installed on the inner wall of the axis groove.

[0016] As a further solution of the present invention: the number of the stepped B-chamfering assemblies is two groups. The stepped B-chamfering assembly includes a chamfering blade and a positioning screw. A screw hole adapted to the positioning screw is provided on the back surface of the flange boring tool, and the screw hole penetrates through the chamfering blade.

[0017] As a further solution of the present invention: a diversion groove is provided on the front surface of the flange boring tool, and the diversion groove is provided on both sides of the five guide strips A. A distal mass ring is fixedly connected to the bottom of the flange boring tool.

[0018] Adopting the above technical solutions, compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] 1. In the present invention, the angular runout adjustment screws of the flange connection bolts evenly distributed on the flange end mass ring of the flange boring tool ensure that the runout value of the distal mass ring is controlled within 0.003. The angular runout adjustment screws push the angular adjustment top pins to orient the flange mating surface, thereby realizing the angular runout adjustment of the flange boring tool. A top pin anti-drop rubber ring is installed between the flange discs to prevent the angular adjustment top pins from falling off, which is convenient for the flange boring tool and the flange interface of the flange tool holder to cause a large runout of the main shaft, and ensures the stability of the hole diameter and cylindricity.

[0020] 2. In the present invention, the stepped A-hole fine boring assembly uses spiral alloy guide strips to wrap the flange boring tool in sections at 30° (not limited to 30°). By using the guiding structures of the guide strip A and the guide strip A, and by adding stepped B-chamfering assemblies, etc., the cylindricity (required to be within 0.04, actually 0.025) and roughness (required Ra0.8, actually Ra0.5) of the fork tube hole of the bicycle front fork arm are ensured to be stable. The support surface of the guide strip A is finely ground to control the roughness within Ra0.1, reducing the friction force, and achieving the effect of eliminating the tool deflection influence of the long overhang ratio.

[0021] 3. The present invention adopts an adjustable locking and adjusting system with an inverted taper and adjustable diameter for the stepped A-hole fine boring assembly. The adjustable precision reaches 0.001 mm in diameter, ensuring the stability of the hole diameter. The adjustment of the inverted taper of the blade ensures the stability of the cylindricity, achieving the effects of rapid tool withdrawal and improved efficiency.

[0022] 4. In the present invention, due to the hollow structure of the flange boring tool and the oil guiding groove, a series of centrally distributed water outlet holes in a spiral arrangement can be additionally provided near the guide bar to further adapt to the machine tool working conditions with the function of central water outlet, enhancing the lubrication and cooling functions.

[0023] 5. The present invention uses a stepped A-hole fine boring assembly and a stepped C fine boring assembly, and adopts a grooved boring chip removal groove, which is an open type that penetrates through three steps, disconnecting the support guide bar unit structure. The chip removal groove has a large space to facilitate the removal of a large amount of boring chips from the three steps. The chip removal groove of the stepped B chamfering assembly adopts a closed chip containing groove because the chips from chamfering cutting are less, and more importantly, it is to avoid using an open chip removal groove to disconnect the spiral guide bar unit again, so that the guide bar unit completely wraps around the support fork barrel hole wall across the oil guiding groove to reduce the jumping influence of interrupted cutting.

[0024] 6. In the present invention, by adjusting and limiting the adjusting screw, the adjusting screw is further used to push the wedge pin to move. The diamond blade is limited by the cooperation between the pressing block and the diamond blade. Then, the diamond blade moves along the inclined surface of the wedge pin to form an adjustable locking and adjusting system. Both the stepped C fine boring assembly and the stepped B chamfering assembly are provided with corresponding locking and adjusting systems, thus achieving the effect of facilitating the adjustment of the tool diameter.

[0025] 7. The present invention reduces the risk of chips from the stepped B chamfering assembly falling into the stepped A-hole fine boring assembly through a closed structure, that is, it reduces the problem of chamfering chips being extruded by the guide bar to scratch the workpiece, resulting in poor roughness and unstable hole diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is the first overall schematic diagram in the embodiment of the present invention;

[0027] Figure 2 is the second overall schematic diagram in the embodiment of the present invention;

[0028] Figure 3 is the overall exploded schematic diagram in the embodiment of the present invention;

[0029] Figure 4 is the schematic diagram of the connection relationship of the flange boring tool in the embodiment of the present invention;

[0030] Figure 5 is the schematic diagram of the stepped A-hole fine boring assembly in the embodiment of the present invention;

[0031] Figure 6Schematic diagram of a flange boring tool in an embodiment of the present invention;

[0032] Figure 7 Schematic diagram of the fine boring assembly for step C in an embodiment of the present invention;

[0033] Figure 8 Partial schematic diagram of a flange boring tool in an embodiment of the present invention.

[0034] In the figure: 1. Flange tool shank; 2. Flange boring tool; 3. Flange connection assembly; 31. Flange connection bolt; 32. Radial runout adjustment screw; 33. Angular runout adjustment screw; 34. Adjusting top pin; 35. Rubber ring for preventing top pin from falling off; 36. Positioning mandrel; 4. Fine boring assembly for step C; 41. Fine boring tool holder for step C; 42. Tool holder locking screw; 43. Diamond finishing fine boring tool; 44. Blade locking screw; 45. Radial adjustment screw; 46. Axial adjustment screw; 5. Guide bar assembly; 51. Guide bar A; 52. Rear guide bar; 53. Flow guide groove; 61. Distal mass ring; 62. Flange end mass ring; 7. Fine boring assembly for step A hole; 71. Pressure block; 72. Diamond blade; 73. Wedge pin; 74. Limit adjustment screw; 75. Blade positioning pin; 76. Double-headed locking screw; 8. Chamfering assembly for step B; 81. Chamfering blade; 82. Positioning screw. Detailed implementation manners

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] Embodiment 1:

[0037] A spiral guide bar composite adjustable fine boring tool for bicycle front fork parts. In the field of bicycle manufacturing, the front fork arm is one of the key components, and the machining of deep hole thin-walled parts in the front fork arm has always been a difficult problem. When traditional machining tools are used to machine such parts, there are often problems such as low precision and poor stability. With the continuous improvement of the requirements for product quality and performance in the bicycle industry, there is an urgent need for a tool that can efficiently and accurately machine the deep hole thin-walled parts of bicycle front fork arms. This need has promoted the research and development of the spiral guide bar composite adjustable fine boring tool, which combines advanced spiral guide bar technology and adjustable functions and can better adapt to the machining of parts with different sizes and precision requirements;

[0038] After retrieval, the applicant found that a Chinese patent disclosed "A deep-hole reamer" with the publication (announcement) number "CN113814473A". This patent mainly sets an arc-shaped protrusion adjacent to the main cutting edge at the bottom of the main cutting tool. During the fine reaming process, the radial force of the deep-hole inner wall on the tool is offset by the arc-shaped protrusions, thereby reducing the vibration of the tool and increasing the machining accuracy. However;

[0039] The Chinese patent also disclosed "A guide-strip type composite stepped boring tool and method for machining the bottom hole of a camshaft" with the publication (announcement) number "CN106825643B". This patent mainly uses a guide-strip type composite stepped boring tool with functions of guiding, semi-finishing and finishing to machine the bottom hole of the three-speed camshaft in the middle of the cylinder block with a single tool, with high machining accuracy. Compared with the original process plan, the machining efficiency is increased by about 50%, and the tool cost is reduced. However, in the actual application process, there are multi-tooth cutting, the cutting resistance causes deformation of thin-walled parts, resulting in unstable hole diameter, and at the same time causing unqualified cylindricity instability; the cutting allowance is large, the chip removal space for multi-tooth and multi-step is insufficient, resulting in chip scratches on the hole wall and unstable roughness; it is impossible to quickly retract the tool with low efficiency, and the retraction requires the same parameters as the feed; the multi-tooth and multi-step composite integral reamer has a high processing cost;

[0040] The Chinese patent also disclosed "A processing method for deep holes" with the publication (announcement) number "CN102303144A". This patent mainly plays a role of multiple corrections through rough and fine boring. 2. The fine boring tool head specially made according to the product characteristics can achieve the best correction effect and can easily adjust the hole diameter. 3. Using a high-precision outer hole as a guide to machine deep holes to ensure the concentricity requirements. 4. The guide sleeve also plays a supporting role, improving the tool rigidity during machining, eliminating the downward force generated by the tool's own weight, thereby improving the machining accuracy. 5. Due to the increased rigidity, the machining efficiency is greatly improved at the same time. However, in the actual application process, during rotary cutting, the straight guide strip will have jumping vibration tool noise when entering and exiting the oil guide groove, resulting in intermittent cutting scratches; if the guide strip area is increased to cover the oil guide groove, the contact area between the guide strip and the workpiece is too large, the friction generates a large amount of heat, the shrinkage rate is large, and the hole deformation size is unstable. However, in the actual application, there is a large tool length-diameter ratio, no guide strip support, easy tool deflection, resulting in unqualified cylindricity and machining a flared hole;

[0041] Based on the above disclosed patents, problems are proposed to be solved for the front fork arm. Specifically, the problems to be solved include reducing the deformation of thin-walled holes to ensure that the hole diameter tolerance is within ±0.015 and the cylindricity is within 0.04; reducing the tool deflection of long overhangs to ensure that the hole diameter and cylindricity are qualified; under the condition of no internal cooling, reasonably discharging chips to ensure that the hole wall roughness meets Ra0.8 and reducing surface scratches to ensure that the roughness is qualified; eliminating the influence of jumping vibration during interrupted cutting of the oil guide groove to ensure that the hole diameter, cylindricity and roughness are qualified; not being affected by the uneven cutting allowance of 0.1 mm to 1.2 mm, directly machining in place, and not causing deformation of the thin-walled hole during cutting resulting in unqualified hole diameter and cylindricity; the tool diameter is adjustable; eliminating the influence of the spindle runout of the machine tool.

[0042] Please refer to the appendix Figure 1 - Appendix Figure 8 , a spiral guide bar composite adjustable fine boring tool for a bicycle front fork part of the present invention includes a flange tool shank 1 and a flange boring tool 2. The flange boring tool 2 includes a flange connection assembly 3 for eliminating spindle runout, a step C fine boring assembly 4 connected to the outer side of the top of the flange boring tool 2, a guide bar assembly 5 connected to the outer side of the bottom of the flange boring tool 2, a step A hole fine boring assembly 7 connected to the guide bar assembly 5, and a step B chamfering assembly 8 connected to the flange boring tool 2;

[0043] The flange connection assembly 3 includes a flange connection bolt 31, a radial runout adjustment screw 32, an angular runout adjustment screw 33, an angular adjustment top pin 34, a top pin anti-detachment rubber ring 35, and a positioning mandrel 36. A positioning groove adapted to the positioning mandrel 36 is provided at the bottom center of the flange tool shank 1. The top surface center of the flange boring tool 2 is connected to the bottom of the positioning mandrel 36. Flange end mass rings 62 are respectively fixedly connected to the outer center of the top of the flange boring tool 2. A threaded groove adapted to the flange connection bolt 31 is provided at the bottom of the flange end mass ring 62, and the threaded groove extends to the inner wall of the flange tool shank 1. Positioning holes adapted to the radial runout adjustment screws 32 are provided on the four sides of the flange tool shank 1. A limiting groove adapted to the angular runout adjustment screw 33 is provided at the bottom end of the flange end mass ring 62. The top surface of the angular runout adjustment screw 33 is in contact with the angular adjustment top pin 34, and the top surface of the angular adjustment top pin 34 is in contact with the bottom periphery of the flange tool shank 1. An anti-detachment groove adapted to the top pin anti-detachment rubber ring 35 is provided on the outer side of the angular adjustment top pin 34, and the angular adjustment top pin 34 is slidably connected to the inner wall of the flange end mass ring 62;

[0044] Arc-shaped grooves adapted to the radial runout adjustment screws 32 are provided on the four sides of the positioning mandrel 36.

[0045] Specific working process: By inserting the positioning mandrel 36 into the inside of the positioning groove, the flange tool shank 1 and the flange boring tool 2 are preliminarily aligned. Then, the flange end mass ring 62 and the flange tool shank 1 are fixed by the flange connection bolts 31, and the flange connection bolts 31 are circumferentially arrayed with the flange boring tool 2 as the center. The included angle between the four flange connection bolts 31 is 90°. By adjusting the angular runout adjusting screw 33, the angular adjusting ejector pin 34 and the ejector pin anti-drop rubber ring 35 are pushed to move upward, so that the flange connection performance between the flange tool shank 1 and the flange boring tool 2 is more stable.

[0046] Furthermore, by ensuring that the runout value of the distal mass ring 61 is controlled within 0.003 by the angular runout adjusting screw 33 evenly distributed on the flange end mass ring 62 of the flange boring tool 2, the angular runout adjusting screw 33 pushes the angular adjusting ejector pin 34 to the directional flange mating surface to realize the angular runout adjustment of the flange boring tool 2. By installing the ejector pin anti-drop rubber ring 35 between the flange plate gaps, the angular adjusting ejector pin 34 is prevented from falling off, which is convenient for preventing the large runout of the spindle caused by the flange interface between the flange boring tool 2 and the flange tool shank 1, and ensuring the stability of the hole diameter and cylindricity.

[0047] Embodiment 2:

[0048] Based on Embodiment 1, please refer to the attached Figure 1 - attached Figure 8 As shown, the step C finish boring assembly 4 includes a step C finish boring tool holder 41, a tool holder locking screw 42, a diamond finishing fine boring blade 43, a blade locking screw 44, a radial adjusting screw 45, and an axial adjusting screw 46. A groove adapted to the step C finish boring tool holder 41 is provided on the front surface of the flange boring tool 2. A locking hole adapted to the tool holder locking screw 42 is provided on the inner wall of the step C finish boring tool holder 41, and the locking hole extends to the inner wall of the flange boring tool 2. A finishing groove adapted to the diamond finishing fine boring blade 43 is provided on the side surface of the step C finish boring tool holder 41. A screw hole adapted to the blade locking screw 44 is provided on the inner wall of the diamond finishing fine boring tool 43. A radial groove adapted to the radial adjusting screw 45 is provided on the back surface of the step C finish boring tool holder 41. An axial groove adapted to the axial adjusting screw 46 is provided on the top surface of the step C finish boring tool holder 41;

[0049] The front end of the diamond finishing fine boring blade 43 extends to the outside of the step C finish boring tool holder 41, and the rear end of the radial adjusting screw 45 is in contact with the inner wall of the finishing groove.

[0050] Specific working process: The step A hole finish boring assembly 7, the step B chamfering assembly 8, and the step C finish boring assembly 4 are sequentially installed on the flange boring tool 2 from bottom to top, and the radii of the components from bottom to top increase in turn.

[0051] Furthermore, through the stepped A-hole fine boring assembly 7 and the stepped C fine boring assembly 4, a grooved boring chip removal groove is adopted, which is open and penetrates through three steps, disconnecting the support guide bar unit structure. The chip removal groove has a large space to facilitate the removal of a large amount of boring chips from the three steps. The chip removal groove of the stepped B chamfering assembly 8 adopts a closed chip containing groove because there is less chip generated during chamfering. More importantly, it is to avoid using an open chip removal groove to disconnect the spiral guide bar unit again, so that the guide bar unit completely wraps around the support fork barrel hole wall across the oil guide groove, reducing the jumping impact of interrupted cutting.

[0052] Embodiment 3:

[0053] Based on Embodiment 2, please refer to the attached Figure 1 - attached Figure 8 As shown, the guide bar assembly 5 includes guide bar A51 and rear guide bar 52. A connection groove adapted to the guide bar A51 is provided on the outer side of the bottom of the flange boring tool 2, and the number of the guide bar A51 is five groups. The five groups of guide bar A51 are vacuum welded at a spiral angle of 30° on the outer side of the bottom of the flange boring tool 2, and the outer side of the rear guide bar 52 is detachably installed on the front of the flange boring tool 2;

[0054] There are two groups of stepped B chamfering assemblies 8. The stepped B chamfering assembly 8 includes a chamfering blade 81 and a positioning screw 82. A screw hole adapted to the positioning screw 82 is provided on the back of the flange boring tool 2, and the screw hole penetrates through the chamfering blade 81.

[0055] Specific working process: All the guide bar A51 and the rear guide bar 52 are made of cemented carbide material with a hardness above HRA93 (HV1750) to ensure the wear resistance of the guide bar A51 and the rear guide bar 52. The flange boring tool 2 is made of tool steel and heat treated to HRC50. The guide bar assembly 5 and the flange boring tool are vacuum welded. This welding method effectively avoids the situation of uneven heat absorption caused by the influence of the external environment during welding, effectively prevents the generation of bubbles during the welding process, defects such as damage to the guide bar alloy material and insecure welding, and improves the welding reliability and stress deformation of the guide bar assembly 5 and the flange boring tool 2.

[0056] Furthermore, the stepped A-hole fine boring assembly 7 uses a spiral alloy guide bar at 30° (not limited to 30°) to segmentally wrap the flange boring tool 2. By using the guiding structures of the guide bar A51 and the guide bar A51, and by adding the stepped B chamfering assembly 8, etc., the cylindricity (required to be within 0.04, actually 0.025) and roughness (required to be Ra0.8, actually Ra0.5) of the fork barrel hole of the bicycle front fork arm are ensured to be stable. The support surface of the guide bar A51 is finely ground to control the roughness within Ra0.1, reducing the friction force, and achieving the effect of eliminating the tool deflection effect of the long overhang ratio.

[0057] Embodiment 4:

[0058] Based on Embodiment 3, please refer to the attached Figure 1 - attached Figure 8 As shown, the number of the stepped A-hole fine boring assemblies 7 is two groups. The two groups of stepped A-hole fine boring assemblies 7 are respectively installed on the front of the bottom of the flange boring tool 2 and the front of the middle position of the flange boring tool 2. The stepped A-hole fine boring assembly 7 includes a pressing block 71, a diamond blade 72, a wedge pin 73, a limiting adjustment screw 74 and a double-headed locking screw 76. Two pressing grooves adapted to the pressing block 71 are provided on the front of the flange boring tool 2. Threaded holes adapted to the double-headed locking screw 76 are provided on the inner walls of both the flange boring tool 2 and the pressing block 71. The front of the pressing block 71 is slidably connected to the back of the diamond blade 72. The front of the wedge pin 73 is provided with an inclined surface, and the inclined surface of the wedge pin 73 is slidably connected to the top surface of the diamond blade 72. The other end of the wedge pin 73 is in contact with the limiting adjustment screw 74;

[0059] An axis groove is provided on the front of the flange boring tool 2, and a blade positioning pin 75 is detachably installed on the inner wall of the axis groove.

[0060] Specific working process: By adjusting the limiting adjustment screw 74, the limiting adjustment screw 74 is further pushed to move the wedge pin 73. The diamond blade 72 is limited by the cooperation between the pressing block 71 and the diamond blade 72. Then, the diamond blade 72 moves along the inclined surface of the wedge pin 73 to form an adjustable locking adjustment system.

[0061] Furthermore, the stepped A-hole fine boring assembly 7 adopts an inverted cone adjustable and diameter adjustable locking adjustment system, and the adjustable precision reaches 0.001 mm in diameter, ensuring the stability of the hole diameter. The adjustment of the inverted cone of the blade ensures the stability of the cylindricity, achieving the effects of rapid tool withdrawal and improved efficiency.

[0062] Embodiment 5:

[0063] Based on Embodiment 4, please refer to the attached Figure 1 - attached Figure 8 As shown, a diversion groove 53 is provided on the front of the flange boring tool 2, and the diversion groove 53 is provided on both sides of five guide bars A51. A distal mass ring 61 is fixedly connected to the bottom of the flange boring tool 2.

[0064] Specific working process: A diversion groove 53 is provided between the flange boring tool 2 and the guide bar A51 to guide the cutting fluid into the diversion groove 53, forming a cutting fluid emulsion oil film between the lubricating guide bar support surface and the fork barrel hole wall, thereby lubricating and cooling the guide bar support surface and the fork barrel hole wall, and reducing the aperture change caused by the thermal expansion and contraction of the thin-walled part due to friction and heat generated by friction.

[0065] Furthermore, a series of centrally distributed spiral water outlet holes can be additionally arranged near the guide bar in the hollow structure of the flange boring tool 2 and in the oil guide groove to further adapt to the machine tool working conditions with the function of central water outlet, and enhance the lubrication and cooling functions.

[0066] The above front, back, left, right, up, and down are all based on the Figure 1 description in the attached drawings of the specification. Taking the observation perspective of a person as the standard, the side of the device facing the observer is defined as the front, and the left side of the observer is defined as the left, and so on.

[0067] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the protection scope of the present invention.

[0068] It should be noted that the device structure and drawings of the present invention mainly describe the principle of the present invention. On the basis of this design principle, the settings of the power mechanism, power supply system, control system, etc. of the device are not fully described. However, on the premise that those skilled in the art understand the principle of the above invention, the specific details of its power mechanism, power supply system, and control system can be clearly known. The control method of the application document is automatically controlled by a controller, and the control circuit of the controller can be realized by simple programming by those skilled in the art;

[0069] The standard parts used therein can all be purchased from the market, and can also be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts, and equipment all adopt conventional models in the prior art, and the components known to those skilled in the art, their structures and principles can all be learned through technical manuals or obtained through conventional experimental methods.

[0070] The embodiments of the present invention have been described in detail above in conjunction with the attached drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions, and variations to these embodiments still fall within the protection scope of the present invention.

Claims

1. A spiral guide bar composite adjustable fine boring tool for bicycle front fork parts, characterized in that: The invention comprises a flange tool holder (1) and a flange boring tool (2), wherein the flange boring tool (2) comprises a flange connection assembly (3) for eliminating spindle runout, a step C fine boring assembly (4) connected to the outer side of the top of the flange boring tool (2), a guide bar assembly (5) connected to the outer side of the bottom of the flange boring tool (2), a step A hole fine boring assembly (7) connected to the guide bar assembly (5), and a step B chamfering assembly (8) connected to the flange boring tool (2); The flange connection assembly (3) comprises a flange connection bolt (31), a radial runout adjustment screw (32), an angular runout adjustment screw (33), an angular adjustment ejector pin (34), an ejector pin anti-slip rubber ring (35) and a positioning mandrel (36); a positioning groove matched with the positioning mandrel (36) is provided at the bottom axis of the flange tool holder (1); the top axis of the flange boring tool (2) is connected to the bottom of the positioning mandrel (36); a flange end mass ring (62) is fixedly connected at the outer center of the top of the flange boring tool (2); a threaded groove matched with the flange connection bolt (31) is provided at the bottom of the flange end mass ring (62); and the threaded groove is provided at the bottom of the flange end mass ring (62). The groove extends to the inner wall of the flange tool handle (1), and the flange tool handle (1) is provided with positioning holes adapted to the radial runout adjustment screw (32) on all sides, and the bottom end of the flange end mass ring (62) is provided with a limiting groove adapted to the angular runout adjustment screw (33), and the top surface of the angular runout adjustment screw (33) is in contact with the angular adjustment ejector pin (34), and the top surface of the angular adjustment ejector pin (34) is in contact with the bottom surface of the flange tool handle (1) on all sides, and the outer side of the angular adjustment ejector pin (34) is provided with an anti-slip groove adapted to the ejector pin anti-slip rubber ring (35), and the angular adjustment ejector pin (34) is slidably connected to the inner wall of the flange end mass ring (62).

2. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 1, characterized in that: The positioning core shaft (36) is provided with arc grooves around its periphery which are matched with the radial runout adjustment screw (32).

3. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 1, characterized in that: The step C fine boring assembly (4) comprises a step C fine boring tool holder (41), a tool holder locking screw (42), a diamond finishing fine boring blade (43), a blade locking screw (44), a radial adjustment screw (45) and an axial adjustment screw (46); the front surface of the flange boring tool (2) is provided with a groove matched with the step C fine boring tool holder (41); the inner wall of the step C fine boring tool holder (41) is provided with a locking hole matched with the tool holder locking screw (42), and the locking hole extends to the flange The inner wall of the boring tool (2), the side surface of the step C fine boring tool holder (41) is provided with a finishing groove matched with a diamond finishing boring blade (43), the inner wall of the diamond finishing boring blade (43) is provided with a screw hole matched with a blade locking screw (44), the back surface of the step C fine boring tool holder (41) is provided with a radial groove matched with a radial adjustment screw (45), and the top surface of the step C fine boring tool holder (41) is provided with an axial groove matched with an axial adjustment screw (46).

4. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 3, characterized in that: The front end of the diamond finishing and fine boring blade (43) extends to the outside of the step C finishing boring tool holder (41), and the rear end of the radial adjustment screw (45) contacts the inner wall of the finishing groove.

5. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 1, characterized in that: The guide bar assembly (5) comprises a guide bar A (51) and a back guide bar (52); a connection groove matched with the guide bar A (51) is provided on the outer side of the bottom of the flange boring tool (2); and the number of the guide bars A (51) is five groups; the five groups of guide bars A (51) are vacuum welded to the outer side of the bottom of the flange boring tool (2) at a helical angle of 30°; and the outer side of the back guide bar (52) can be detachably mounted on the front side of the flange boring tool (2).

6. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 1, characterized in that: The number of the step A hole fine boring assemblies (7) is two groups. The two groups of the step A hole fine boring assemblies (7) are respectively installed on the bottom front of the flange boring tool (2) and the front of the middle position of the flange boring tool (2). The step A hole fine boring assemblies (7) include a pressing block (71), a diamond blade (72), a wedge pin (73), a limiting adjustment screw (74) and a double-headed locking screw (76). The front of the flange boring tool (2) is provided with two holes which are connected to the pressing block (71). The inner wall of the flange boring tool (2) and the inner wall of the pressure block (71) are both provided with threaded holes that are compatible with the double-head locking screw (76), the front side of the pressure block (71) is slidably connected to the back side of the diamond blade (72), the front side of the wedge pin (73) is provided with an inclined surface, and the inclined surface of the wedge pin (73) is slidably connected to the top surface of the diamond blade (72), and the other end of the wedge pin (73) is in contact with the limiting adjustment screw (74).

7. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 6, characterized in that: The front side of the flange boring tool (2) is provided with an axial groove, and a blade positioning pin (75) is detachably mounted on the inner wall of the axial groove.

8. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 1, characterized in that: The step B chamfering assembly (8) is divided into two groups, and the step B chamfering assembly (8) comprises a chamfering blade (81) and a positioning screw (82). The back of the flange boring tool (2) is provided with a screw hole matched with the positioning screw (82), and the screw hole passes through the chamfering blade (81).

9. The spiral guide composite adjustable fine boring tool for bicycle front fork parts according to claim 5, characterized in that: A guide groove (53) is provided on the front of the flange boring tool (2), and the guide groove (53) is provided on both sides of the five groups of guide bars A (51). A distal mass ring (61) is fixedly connected to the bottom of the flange boring tool (2).

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