Weight-reducing high-precision machining modular boring tool

Abstract

The utility model belongs to boring cutter technical field, concretely relates to lightened high accuracy processing modular boring cutter, including all adopt steel and coaxial splicing's front tool body, rear tool body and intermediate core machine, the outer diameter of rear tool body is greater than the outer diameter of front tool body, front tool body and rear tool body all have two or more than two circumferential distribution's cantilever, all install boring blade and guide strip on every cantilever, the inside of intermediate core machine has hollow inner chamber and axial liquid cooling channel along its axial direction extension, the outside has lightened hole and annular liquid cooling tank, the front tool body and rear tool body all are equipped with sealed cavity, a plurality of blade liquid cooling channels with sealed cavity intercommunication and the export towards corresponding boring blade and a plurality of guide strip liquid cooling channels with sealed cavity intercommunication and the export between guide strip and boring blade, annular liquid cooling tank, axial liquid cooling channel, blade liquid cooling channel, guide strip liquid cooling channel and installation cavity all intercommunication. The utility model can consider boring cutter rigidity, processing accuracy and processing efficiency simultaneously, has greater market application prospect.

Description

Technical Field

[0001] This utility model belongs to the field of boring tool technology, specifically relating to a modular boring tool for high-precision machining with reduced weight. Background Technology

[0002] The motor housing is the core load-bearing component of the motor, and its inner diameter must strictly match the assembly requirements of the stator and rotor. The stator outer diameter of high-torque drive motors in new energy vehicles is typically 200mm~270mm, which requires the maximum cutting diameter of the boring bar to cover the inner diameter of the motor housing, dictating that the boring bar's diameter cannot be too small. Furthermore, the deep-hole characteristics of the motor housing further require the boring bar to have sufficient axial extension length, resulting in a further increase in the overall size of the boring bar. Because the tool body needs to withstand significant radial cutting forces during large-diameter boring, traditional solutions typically choose high-density, high-strength steel. This leads to a dramatic increase in the weight of the boring bar at larger sizes. An excessively heavy boring bar, due to its high inertia and poor rigidity, exacerbates cutting vibration and tool body deformation during machining, directly affecting the key accuracy indicators of the motor housing. Moreover, an excessively heavy boring bar exceeds the rated load of the machine tool spindle, accelerating spindle bearing wear and reducing spindle accuracy. Therefore, existing technologies seek ways to reduce the weight of boring tools while meeting the machining accuracy requirements of the motor housing.

[0003] Existing technologies use aluminum boring tools to replace steel boring tools for weight reduction, but this makes it impossible to manufacture guide bar boring tools, resulting in low machining accuracy. The guide bar in a guide bar boring tool is used to support the tool body during boring, reducing vibration and ensuring machining accuracy, especially for large-diameter boring, where the guide bar needs to fit snugly against the hole wall and withstand a certain radial force. However, because aluminum has lower strength and rigidity than steel, especially in fatigue strength and resistance to deformation, the guide bar will generate friction and pressure with the inner wall of the workpiece during machining. If aluminum is used to make the guide bar or the guide bar mounting structure on the tool body, it is prone to deformation and wear under stress, leading to a decrease in the fit between the guide bar and the hole wall, which in turn generates vibration and affects accuracy. Furthermore, a large amount of cutting heat is generated during cutting, and aluminum has a higher coefficient of thermal expansion than the guide bar. The difference in expansion between the aluminum tool body and the guide bar can cause a shift in the relative position of the guide bar and the aluminum conductor, changing the positional accuracy of the guide bar and resulting in deviations in the boring dimensions. Without guide bar support, the tool body will generate cutting vibration due to long cantilever and insufficient rigidity when boring large diameter holes. This directly leads to poor roundness of the hole, worse surface roughness of the hole wall, and large fluctuations in hole diameter, which cannot meet the assembly requirements of the motor housing and stator.

[0004] Existing technologies also include the continued use of steel boring tools, with the tool body flattened or hollowed out to reduce weight. While steel tool bodies have high strength and can be used as guide bar boring tools, the weight reduction method of flattening / hollowing out compromises the structural integrity of the tool body, leading to problems such as limited number of cutting edges and difficulty in designing internal cooling. If a multi-flute design is used (e.g., four-flute), each edge needs a mounting position on the tool body. Multiple edges increase the radial load on the tool body, and a flattened / hollowed steel tool body may not be able to withstand uniform radial forces when multiple edges are cutting simultaneously, easily leading to tool body deformation or vibration. A two-flute design can symmetrically distribute the cutting edge in the high-rigidity area that is not flattened / hollowed out. During cutting, the radial forces cancel each other out, resulting in more stable tool body stress. Even if the rigidity is reduced, it can avoid severe vibration. Therefore, traditional steel tool bodies, after weight reduction, mostly can only choose two-flute designs, sacrificing machining efficiency for basic machining stability.

[0005] Traditional integral steel tool bodies typically employ an internal cooling channel design combining axial straight holes and radial branch holes. However, flattening / hollowing out the radial branch holes cuts off the coolant, preventing it from reaching the cutting edge. Designing the cooling channel around the hollowed-out area results in a curved channel, significantly increasing machining difficulty. Furthermore, the internal cooling channel requires sufficient wall thickness to prevent leakage. Flattened / hollowed-out steel tool bodies often have thinner walls in certain areas, which decreases further after drilling. This makes them prone to burn-through during welding, leading to coolant leakage and ineffective cooling of the cutting edge. Therefore, most manufacturers opt for external cooling instead of internal cooling. The reduced number of cutting edges and the absence of internal cooling directly result in decreased machining efficiency. Utility Model Content

[0006] Therefore, the purpose of this utility model is to provide a lightweight, high-precision modular boring tool to solve the technical problem that existing boring tool weight reduction methods cannot simultaneously take into account the rigidity, machining accuracy, and machining efficiency of the boring tool.

[0007] To solve the above problems, the present invention provides a lightweight, high-precision modular boring tool with the following technical solution: A lightweight, high-precision modular boring tool includes a front tool body, a rear tool body, and an intermediate core machine, all made of steel and coaxially spliced. The outer diameter of the rear cutter body is larger than that of the front cutter body. Both the front and rear cutter bodies have two or more cantilevers that are distributed in a circular pattern. Each cantilever is equipped with a boring bar and a guide bar. The intermediate core machine has a hollow inner cavity and an axial liquid cooling channel extending along its axis, and a weight reduction hole and an annular liquid cooling tank on the outside. Multiple axial liquid cooling channels and weight reduction holes are arranged around the circumference of the intermediate core machine. Both the front and rear cutter bodies are provided with a sealing cavity for coaxial insertion and sealing with the intermediate core machine, multiple blade liquid cooling channels communicating with the sealing cavity and with the outlet facing the corresponding boring blade, and multiple guide bar liquid cooling channels communicating with the sealing cavity and with the outlet located between the guide bar and the boring blade. The side of the rear cutter body facing away from the sealing cavity is also provided with a mounting cavity for sealing assembly with the tool holder. The mounting cavity is connected to the coolant inlet channel on the tool holder. The annular liquid cooling tank, axial liquid cooling channel, blade liquid cooling channel, guide bar liquid cooling channel, and mounting cavity are all interconnected. The beneficial effects of this utility model are as follows: The weight-reducing high-precision modular boring bar of this utility model adopts a split splicing structure. Each module, such as the front tool body, rear tool body, and intermediate core machine, is made of steel, allowing for the installation of guide bars. The guide bars and boring inserts work together to ensure machining accuracy. Simultaneously, each module can be designed with an independent liquid cooling structure. The corresponding guide bar liquid cooling channels and insert liquid cooling channels in the front and rear tool bodies are connected through the annular liquid cooling tank and axial liquid cooling channel on the central core machine, achieving dual cooling of the boring inserts and guide bars. Furthermore, the intermediate core machine, as the rigid connection structure linking the front and rear tool bodies, is the main weight component of the entire weight-reducing high-precision modular boring bar. While meeting the machining depth requirements, the intermediate core machine can be hollowed out to reduce weight without affecting the rigidity of the entire weight-reducing high-precision modular boring bar, thereby reducing the overall weight of the tool without the need to destroy the overall structure through flattening / hollowing out as with traditional integral steel boring bars. Furthermore, while ensuring the rigidity of the entire weight-reducing, high-precision modular boring tool is met by the central core machine, the front and rear tool bodies can be designed with at least two cutting edges, thereby improving cutting efficiency. In addition, the outer diameter of the rear tool body is larger than that of the front tool body, enabling the machining of multiple hole diameters in a single setup, reducing the number of setups, avoiding repetitive positioning errors, and improving machining efficiency. Therefore, this invention's weight-reducing, high-precision modular boring tool simultaneously balances boring tool rigidity, machining accuracy, and machining efficiency, and has promising market application prospects.

[0008] Furthermore, the front end of the intermediate core machine is provided with a flange connection part, and the flange connection part is provided with a plurality of axial locking holes evenly distributed around the circumference of the intermediate core machine, and the front cutter body is provided with screw holes corresponding one-to-one with the axial locking holes.

[0009] Beneficial effects: The flange connection has a large contact area, and with the axial locking force of the screws, it can prevent relative loosening between the front cutter body and the intermediate core machine during high-speed cutting, reduce vibration sources, and ensure machining stability.

[0010] Furthermore, the sealing cavity on the front cutter body is defined as the front sealing cavity, and the sealing cavity on the rear cutter body is defined as the rear sealing cavity; an organic positioning step is provided on the rear side of the flange connection on the intermediate core machine, and an annular liquid cooling groove is located between the flange connection and the machine positioning step; the rear sealing cavity is provided with a positioning protrusion for coaxial insertion with the hollow inner cavity and a cutter body positioning step for cooperating with the rear end stop of the intermediate core machine, and the positioning protrusion, the cavity wall of the rear sealing cavity, and the end of the intermediate core machine form an annular fluid groove that connects the various axial liquid cooling channels.

[0011] Beneficial effects: The body positioning steps and the tool body positioning steps can respectively position the front and rear ends of the intermediate core machine, ensuring the coaxiality of the front tool body, rear tool body and intermediate core machine; the insertion fit between the positioning protrusion and the hollow inner cavity increases the contact area between the rear tool body and the intermediate core machine, ensuring the rigidity of the overall structure; the annular fluid groove can evenly distribute the coolant into each axial liquid cooling channel, and finally evenly distribute it to each guide bar / insert liquid cooling channel of the front tool body through the annular liquid cooling groove, achieving a consistent cooling effect for each cutting edge of the front tool body and the guide bar.

[0012] Furthermore, sealing rings are provided at the mating parts of the intermediate core machine with the front and rear cutter bodies, and the splicing seams of the intermediate core machine with the front and rear cutter bodies are welded.

[0013] Beneficial effects: Welding can completely eliminate the gap between the intermediate core machine and the front and rear cutter bodies, forming a double seal with the sealing ring to prevent coolant leakage; in addition, the welding method makes the intermediate core machine, the front and rear cutter bodies into a whole structure. The torsional and deformation resistance of this whole structure is close to that of traditional one-piece steel boring tools, but the weight is greatly reduced compared to traditional one-piece steel boring tools, thus solving the contradiction between weight reduction and rigidity.

[0014] Furthermore, in each cantilever of the front and rear cutter bodies, the included angle between any two adjacent cantilevers is different; at least two cantilevers of the front and rear cutter bodies are provided with dynamic balancing structures to ensure that the rotation centers of the front and rear cutter bodies are located on the axis of the central core machine.

[0015] Beneficial effects: The different cantilever angles ensure that the boring tools on the corresponding cantilever arms do not cut into the workpiece simultaneously, but rather in a staggered cutting state. This avoids radial force concentration caused by simultaneous multi-edge cutting, reduces instantaneous deformation of the tool body, and improves the surface quality of the motor housing bore. The dynamic balancing structure adjusts the tool body's center of gravity, ensuring that the rotation centers of the front and rear tool bodies are located on the axis of the central core machine. This prevents vibration of the tool body caused by uneven weight distribution and ensures the stability of the motor housing bore diameter.

[0016] Furthermore, the cantilever arms at corresponding positions of the front and rear cutter bodies are offset by a set angle in the circumferential direction of the intermediate core machine.

[0017] Beneficial effects: With the cantilevered arms of the front and rear cutting edges staggered, the cutting forces are distributed across different axial planes, avoiding the superposition of forces on the same radial plane and reducing bending deformation of the cutting edges. Furthermore, the chip removal paths generated by the front and rear cutting edges are staggered in time and space, preventing chip interference and ensuring smoother chip removal.

[0018] Furthermore, the boring bar can be detachably connected to the corresponding cantilever.

[0019] Beneficial effects: When the boring bar wears out, only the boring bar needs to be replaced, instead of replacing the entire tool body, which reduces maintenance costs; in addition, boring bars of different materials can be flexibly replaced according to the material of the workpiece being machined, adapting to a variety of machining scenarios and improving versatility.

[0020] Furthermore, the cantilever is provided with a communicating blade mounting groove, a pressing groove, and a positioning groove. A positioning element is installed in the positioning groove, and a clamping element is installed in the pressing groove. The boring blade has a positioning surface, an inclined pressing surface, and a contact surface. The clamping element has a clamping surface that mates with the inclined pressing surface. The clamping element is fixed to the cantilever by locking screws to clamp the boring blade. The contact surface is in contact with the bottom wall of the blade mounting groove, and the positioning surface abuts against the positioning element.

[0021] Beneficial effects: Ensures accurate installation of boring tools and secure fixation of boring tools.

[0022] Furthermore, the cantilever is also provided with a tool body adjustment mechanism for adjusting the radial position of the boring tool. The tool body adjustment mechanism includes a pressing component and an adjusting component. The adjusting component is threadedly connected to the cantilever, and the pressing component is movably assembled with the cantilever. The boring tool also has an adjusting inclined surface. The pressing component has a pressing inclined surface that cooperates with the adjusting inclined surface. The adjusting inclined surface abuts against the corresponding groove sidewall of the tool mounting groove. When the adjusting component rotates, it pushes the pressing component to move, thereby pushing the boring tool to move radially along the corresponding tool body.

[0023] Beneficial effects: It facilitates fine adjustment of the radial position of the boring bar, adapts to the machining requirements of different hole diameters, and can also compensate for the wear of the boring bar, avoiding scrap rate caused by deviation.

[0024] Furthermore, the dynamic balancing structure is a groove formed on the corresponding cantilever, and the groove depth is different on different cantilevers; the adjusting member and the pressing member on the cantilever with the dynamic balancing structure are inserted into the cantilever from one side of the groove.

[0025] Beneficial effects: The dynamic balancing structure adopts the form of a groove, which can take into account both dynamic balance and weight reduction, without the need to add additional counterweights; the adjusting parts and extruding parts can be hidden in the groove and do not protrude from the cantilever surface, making the structure more compact. At the same time, it can also avoid interference with the motor housing hole wall during processing, and reduce the erosion of the adjusting parts and extruding parts by chips and coolant. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the assembled structure of the weight-reducing, high-precision modular boring tool and tool holder of this utility model. Figure 2 for Figure 1 The main view; Figure 3 for Figure 2 AA section view; Figure 4 for Figure 2 Top view; Figure 5 for Figure 4 BB cross-sectional view; Figure 6 This is a schematic diagram of the intermediate core machine. Figure 7 for Figure 6 A sectional view; Figure 8 A schematic diagram of the three-dimensional structure of the front cutter body; Figure 9 This is the front view of the front cutter body; Figure 10 for Figure 9 CC section view; Figure 11 for Figure 9 DD sectional view; Figure 12 This is a schematic diagram of the front view of the rear blade. Figure 13 This is a schematic diagram of the rear view of the rear cutter body; Figure 14 This is the front view of the rear cutter body; Figure 15 for Figure 14 EE sectional view; Figure 16 for Figure 14 FF sectional view; Figure 17 This is a schematic diagram showing the fit between the boring bar, pressure block, adjusting component, and extruding component.

[0027] Explanation of reference numerals in the attached figures: 1. Front cutter body; 11. Front cantilever; 111. Front cooling channel; 112. Front blade liquid cooling channel; 113. Front guide bar liquid cooling channel; 114. Dynamic balancing structure; 115. Blade mounting slot; 116. Pressure groove; 117. Positioning groove; 12. Positioning component; 13. Adjusting component; 14. Extrusion component; 15. Clamping component; 151. Clamping surface; 16. Cover plate; 17. Front screw through hole; 18. Front sealing cavity; 2. Intermediate core unit; 21. Flange connection; 211. Axial locking hole; 22. Hollow inner cavity; 23. Weight reduction hole; 24. Axial liquid cooling channel; 25. Body positioning step; 26. Annular liquid cooling tank; 3. Rear cutter body; 31. Rear cantilever; 311. Rear cutter liquid cooling channel; 312. Rear guide bar liquid cooling channel; 313. First rear cooling channel; 314. Second rear cooling channel; 32. Rear sealing cavity; 33. Mounting cavity; 34. Positioning protrusion; 35. Cutter body positioning step; 36. Rear threaded locking hole; 37. Plug hole; 38. Plug; 39. Liquid outlet; 4. Tool holder; 41. Coolant inlet channel; 42. Coolant outlet; 5. Boring tool; 51. Positioning surface; 52. Inclined pressure surface; 53. Contact surface; 54. Adjusting slope; 6. Guide bar; 7. Annular fluid groove. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0029] An embodiment of a weight-reducing, high-precision modular boring tool provided by this utility model: like Figure 1 and Figure 2 As shown, the lightweight, high-precision modular boring tool includes a front tool body 1, a rear tool body 3, and an intermediate core machine 2, all made of steel and coaxially assembled. The intermediate core machine 2 is located between the front tool body 1 and the rear tool body 3, and the rear tool body 3 is used to connect to the tool holder 4. Boring inserts 5 and guide bars 6 are mounted on both the front tool body 1 and the rear tool body 3.

[0030] Specifically, such as Figure 6 and Figure 7 As shown, the intermediate core 2 has a cylindrical structure with an internal hollow cavity 22 extending along its axis and an axial liquid cooling channel 24, and external weight-reducing holes 23 and an annular liquid cooling tank 26. Four axial liquid cooling channels 24 are evenly arranged around the circumference of the intermediate core 2, extending to the front and rear ends of the intermediate core 2 and penetrating the annular liquid cooling tank. Two sets of weight-reducing holes 23 are arranged along the axis of the intermediate core 2, each set including multiple weight-reducing holes 23 arranged around the circumference of the intermediate core 2. It should be noted that the number of sets of weight-reducing holes 23 can be reasonably set according to the length of the intermediate core 2, provided that the rigidity of the overall structure is not affected.

[0031] like Figure 6As shown, the intermediate core machine 2 has a flange connection part 21 on the front side of the annular liquid cooling tank, and the flange connection part 21 has a plurality of axial locking holes 211 evenly distributed around the circumference of the intermediate core machine 2; an organic positioning step 25 is provided on the intermediate core machine 2 on the rear side of the annular liquid cooling tank 26.

[0032] like Figure 2 and Figure 8 As shown, the front cutter body 1 has four circumferentially distributed front cantilever arms 11, each front cantilever arm 11 being equipped with a boring bar 5 and a guide bar 6. A front sealing cavity 18, coaxial with the central core machine 2, is provided on the side of the front cutter body 1 facing it. The front cutter body 1 also has front screw through holes 17 corresponding one-to-one with the aforementioned axial locking holes 211. (As shown...) Figure 10 and Figure 11 As shown, each of the four front cantilever arms 11 has a front cooling channel 111 inside. One end of the front cooling channel 111 extends to the cavity wall of the front sealing cavity 18 and then communicates with the front sealing cavity 18.

[0033] like Figure 5 As shown, the front end of the intermediate core machine 2 is coaxially inserted into the front sealing cavity 18, and a sealing ring is provided between the intermediate core machine 2 and the cavity wall of the front sealing cavity 18 for sealing. After insertion, the flange connection 21 and the annular liquid cooling tank 26 are both located inside the front sealing cavity 18. The intermediate core machine 2 is positioned at the machine body positioning step 25 and engages with the external stop of the front cutter body 1. The front end of the flange connection 21 engages with the bottom stop of the front sealing cavity 18, and the four front cooling channels 111 are exactly opposite to and connected to the annular liquid cooling tank 26. The axial locking hole 211 is coaxially corresponding to the front screw through hole 17. The intermediate core machine 2 and the front cutter body 1 are fastened together by installing screws at the axial locking hole 211 and the front screw through hole 17. At the same time, the joint between the intermediate core machine 2 and the front cutter body 1 is welded and sealed to ensure that the coolant does not flow out.

[0034] like Figure 8 and Figure 9 As shown, the front cantilever 11 is provided with a communicating blade mounting groove 115, a pressing groove 116, and a positioning groove 117, wherein, as Figure 1 As shown, a positioning element 12, which is a pin, is installed in the positioning groove 117; a clamping element 15 is installed in the pressing groove 116; and a boring bar 5 is installed in the blade mounting groove 115. In this embodiment, as... Figure 17As shown, the boring bar 5 has a positioning surface 51, an inclined pressure surface 52, a contact surface 53, and an adjusting slope 54. The clamping member 15 has a clamping surface 151 that mates with the inclined pressure surface 52. During installation, the contact surface 53 on the boring bar 5 is placed against the bottom wall of the insert mounting groove 115, the positioning surface 51 abuts against the positioning member 12, and the adjusting slope 54 abuts against the corresponding side wall of the insert mounting groove 115. Then, the clamping member 15 is installed so that the clamping surface 151 on the clamping member 15 contacts the inclined pressure surface 52 of the boring bar 5. The clamping member 15 is then fastened to the front cantilever 11 with locking screws to clamp the boring bar 5. In actual machining, considering the wear of the boring bar 5 and the adjustment of the inner diameter of the workpiece, a tool body adjustment mechanism for adjusting the radial position of the boring bar 5 is also provided on the front cantilever 11. The tool body adjustment mechanism includes a pressing component 14 and an adjusting component 13. The adjusting component 13 is threadedly connected to the cantilever, and the pressing component 14 is movably assembled with the cantilever. The pressing component 14 is provided with a pressing inclined surface that cooperates with the adjusting inclined surface 54. When it is necessary to adjust the radial position of the boring tool 5, the adjusting component 13 is rotated. At this time, the adjusting component 13 pushes the pressing component 14 to move, and the pressing inclined surface pushes the boring tool 5 to move radially along the front tool body 1.

[0035] In this embodiment, as Figure 11 As shown, the included angle between any two adjacent front cantilever arms 11 is not the same. In actual machining, the included angle between the four front cantilever arms 11 can be 80°, 85°, 95°, or 110°. Of course, it is not limited to the above angles; a reasonable degree design can be made according to actual requirements. To ensure that the center of gravity of the front tool body 1 is located on its axis of rotation, that is, on the axis of the intermediate core machine 2, as shown... Figure 8 As shown, dynamic balancing structures 114 are provided on three of the front cantilever arms 11. The dynamic balancing structure 114 is a groove formed on the corresponding front cantilever arm 11, with different groove depths on different front cantilever arms 11. Adjusting members 13 and pressing members 14 on the front cantilever arm 11 with the dynamic balancing structure 114 pass through the groove from one side into the front cantilever arm 11. It should be noted that in actual processing, dynamic balancing structures 114 can be provided on a corresponding number of front cantilever arms 11 according to processing requirements.

[0036] The guide bar 6 is made of alloy or PCD material and is fixed to the front suspension arm 11 by adhesive bonding. For example... Figure 1 and Figure 9 As shown, each front cantilever 11 has a front guide bar liquid cooling channel 113 located between the guide bar 6 and the boring bar 5. A cover plate 16 is provided at the inlet of the front guide bar liquid cooling channel 113 to guide the coolant along the surface of the front cantilever 11. Figure 10As shown, each front cantilever 11 is also machined with a front blade liquid cooling channel 112, the outlet of which faces the boring bar 5. The front guide bar liquid cooling channel 113 and the front blade liquid cooling channel 112 are both connected to the front cooling channel 111 at the corresponding positions.

[0037] like Figure 3 As shown, the outer diameter of the rear cutter body 3 is larger than the outer diameter of the front cutter body 1, as... Figure 12 , Figure 13 and Figure 14 As shown, the rear cutter body 3 has four circumferentially distributed rear cantilever arms 31. Boring inserts 5 and guide bars are mounted on each of the four rear cantilever arms 31. The mounting method of the boring inserts 5 and guide bars on the rear cantilever arms 31 is the same as that on the front cantilever arms 11, and will not be described in detail here. Figure 4 As shown, after the rear cutter body 3 is assembled with the intermediate core machine 2, the rear cantilever 31 and the front cantilever 11 at corresponding positions are offset by a set angle in the circumferential direction of the intermediate core machine 2. It should be noted that the number of front cantilever 11 and rear cantilever 31 can be reasonably designed according to actual processing requirements, and is not limited to the four in this embodiment. Under certain conditions, more than five can be designed to achieve a multi-blade design.

[0038] like Figure 12 As shown, the front side of the rear cutter body 3 is provided with a rear sealing cavity 32 that is coaxially inserted and sealed to the rear end of the intermediate core machine 2, as shown in the figure. Figure 13 As shown, the rear side of the rear cutter body 3 is provided with a mounting cavity 33 for coaxial insertion and sealing with the cutter shank 4. The rear sealing cavity 32 contains a positioning protrusion 34 coaxially inserted with the hollow inner cavity 22 and a cutter body positioning step 35 that engages with the rear end stop of the intermediate core machine 2. The positioning protrusion 34, the cavity wall of the rear sealing cavity 32, and the rear end of the intermediate core machine 2 form an annular fluid groove 7 connecting the various axial liquid cooling channels 24. A sealing ring is provided between the intermediate core machine 2 and the cavity wall of the rear sealing cavity 32 for sealing. Simultaneously, the joint between the intermediate core machine 2 and the rear cutter body 3 is also welded and sealed to ensure that the coolant does not leak out. Figure 5 and Figure 12 As shown, a first rear cooling channel 313 is provided on the rear cutter body 3 at the position corresponding to each axial liquid cooling channel 24, such as... Figure 16 As shown, a second rear cooling channel 314 communicating with each first rear cooling channel 313 is provided at the corresponding position; a rear guide bar liquid cooling channel 312 is provided on each rear cantilever 31 at the position between the guide bar and the boring bar 5, and a cover plate 16 is also provided at the inlet of the rear guide bar liquid cooling channel 312, thereby guiding the coolant along the surface of the rear cantilever 31. Figure 15As shown, each rear cantilever 31 is also machined with a rear blade liquid cooling channel 311, the outlet of which faces the boring bar 5. The rear guide bar liquid cooling channel 312 and the rear blade liquid cooling channel 311 are both connected to the second rear cooling channel 314 at the corresponding positions.

[0039] like Figure 13 As shown, the cavity wall of the mounting cavity 33 is provided with a coolant inlet 39 that communicates with the corresponding second rear cooling channel 314. The inside of the tool holder 4 is provided with a coolant inlet channel 41. The part of the tool holder 4 used for insertion and mating with the mounting cavity 33 is provided with an outlet 42 at the position corresponding to each coolant inlet 39. The rear end face of the rear tool body 3 is provided with a plurality of circumferentially evenly distributed rear threaded locking holes 36. The rear threaded locking holes 36 correspond one-to-one with the rear screw through holes on the flange of the tool holder 4, and the two are fixedly connected by locking screws. The rear tool body 3 is provided with a plurality of circumferentially distributed plug holes 37. The plug holes 37 communicate with the mounting cavity 33, and a plug 38 is provided at the plug hole 37 to prevent coolant leakage.

[0040] The tool holder 4 can be a general-purpose tool holder such as HSK or BT, and can be flexibly selected according to the actual machining situation. In this embodiment, no specific limitation is made.

[0041] During processing, such as Figure 3 and Figure 5 As shown, coolant flows in from the coolant inlet channel 41 inside the tool holder 4, and from the outlet 42 on the tool holder 4 into the various liquid passages 39 of the rear tool body 3, and then into the various second rear cooling channels 314. Through the second rear cooling channels 314, it enters the various rear guide bar liquid cooling channels 312 and the rear cutting tool liquid cooling channels 311 to cool the boring tool 5 and guide bar 6 mounted on the rear cantilever 31. At the same time, the coolant also flows into the corresponding first rear... In the cooling channel 313, the coolant in the first rear cooling channel 313 continues to flow forward and into the annular fluid tank 7, and flows evenly into the four axial liquid cooling channels 24. It then flows through the four axial liquid cooling channels 24 to the annular liquid cooling tank 26, and then to each of the front cooling channels 111. Through the front cooling channels 111, it flows into each of the front guide bar liquid cooling channels 113 and the front blade liquid cooling channels 112 to cool the boring bar 5 and guide bar 6 installed on the front cantilever 11.

[0042] This utility model discloses a weight-reducing, high-precision modular boring bar. It employs a modular, split-assembly structure to reduce weight. The front tool body 1, rear tool body 3, and intermediate core machine 2 can be designed independently, reducing production costs and shortening the overall manufacturing time. The intermediate core machine 2, as the component responsible for the rigidity of the entire weight-reducing, high-precision modular boring bar, achieves weight reduction through a hollowing-out design without compromising overall rigidity, significantly lowering the overall weight. The front tool body 1 and rear tool body 3 can be designed with multi-edge cutting to improve machining efficiency. The cooperation between the guide bar 6 and the boring bar 5 can counteract cutting vibrations and ensure machining accuracy. Liquid cooling channels can be individually machined on the front tool body 1, rear tool body 3, and intermediate core machine 2. Annular grooves are designed at the connection points to connect these channels, thereby reducing the wear rate of the boring bar 5 during machining and improving machining efficiency. Furthermore, the boring bar 5 is detachable, allowing for the replacement of different material types of inserts according to machining requirements.

[0043] It should be noted that the modular boring tool for weight reduction and high precision machining of this utility model is not limited to machining the inner hole of the motor housing; it can be used to machine any large-diameter, high-precision stepped hole.

[0044] In other embodiments, the boring bar can also be welded to the corresponding cantilever, in which case the adjusting and pressing components are not required.

[0045] Based on the above description in this specification, those skilled in the art will also understand that the following terms, such as "front," "rear," "inner," and "outer," which indicate orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not imply that the device or element involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as a limitation on the present invention.

[0046] In the description of this specification, "multiple" means at least two, such as two, three or more, etc., unless otherwise expressly and specifically defined.

[0047] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A weight-reducing high-precision machining modular boring bar, characterized in that, This includes a front cutter body, a rear cutter body, and an intermediate core machine, all made of steel and coaxially spliced. The outer diameter of the rear cutter body is larger than that of the front cutter body. Both the front and rear cutter bodies have two or more cantilevers that are distributed in a circular pattern. Each cantilever is equipped with a boring bar and a guide bar. The intermediate core machine has a hollow inner cavity and an axial liquid cooling channel extending along its axis, and a weight reduction hole and an annular liquid cooling tank on the outside. Multiple axial liquid cooling channels and weight reduction holes are arranged around the circumference of the intermediate core machine. Both the front and rear cutter bodies are provided with a sealing cavity for coaxial insertion and sealing with the intermediate core machine, multiple blade liquid cooling channels communicating with the sealing cavity and with the outlet facing the corresponding boring blade, and multiple guide bar liquid cooling channels communicating with the sealing cavity and with the outlet located between the guide bar and the boring blade. The side of the rear cutter body facing away from the sealing cavity is also provided with a mounting cavity for sealing assembly with the tool holder. The mounting cavity is connected to the coolant inlet channel on the tool holder. The annular liquid cooling tank, axial liquid cooling channel, blade liquid cooling channel, guide bar liquid cooling channel, and mounting cavity are all interconnected.

2. The high-precision machining modular boring bar of claim 1, wherein, The front end of the intermediate core machine is provided with a flange connection part, and the flange connection part is provided with a plurality of axial locking holes evenly distributed around the circumference of the intermediate core machine. The front cutter body is provided with screw holes corresponding to the axial locking holes one by one.

3. The high-precision machining modular boring bar of claim 2, wherein, The sealing cavity on the front cutter body is defined as the front sealing cavity, and the sealing cavity on the rear cutter body is defined as the rear sealing cavity. An organic positioning step is provided on the rear side of the flange connection on the intermediate core machine, and an annular liquid cooling groove is located between the flange connection and the machine positioning step. The rear sealing cavity is provided with a positioning protrusion for coaxial insertion with the hollow inner cavity and a cutter body positioning step for cooperating with the rear end stop of the intermediate core machine. The positioning protrusion, the cavity wall of the rear sealing cavity, and the end of the intermediate core machine form an annular fluid groove that connects the various axial liquid cooling channels.

4. The high-precision machining modular boring bar of claim 3, wherein, Sealing rings are provided at the mating parts of the intermediate core machine with the front and rear cutter bodies, and the splicing seams of the intermediate core machine with the front and rear cutter bodies are welded.

5. The high-precision machining modular boring bar of claim 1, wherein, In each cantilever of the front and rear cutter bodies, the included angle between any two adjacent cantilevers is different; at least two cantilevers of the front and rear cutter bodies are provided with dynamic balancing structures to ensure that the rotation center of the front and rear cutter bodies is located on the axis of the central core machine.

6. The high-precision machining modular boring bar of claim 5, wherein, The cantilever arms at corresponding positions of the front and rear cutter bodies are offset by a set angle in the circumferential direction of the central core machine.

7. A high-precision machining modular boring bar for weight reduction according to claim 5 or 6, characterized in that, The boring bar can be detachably connected to the corresponding cantilever.

8. The high-precision machining modular boring bar of claim 7, wherein, The cantilever is provided with a communicating blade mounting groove, a pressing groove, and a positioning groove. A positioning element is installed in the positioning groove, and a clamping element is installed in the pressing groove. The boring blade has a positioning surface, an inclined pressing surface, and a contact surface. The clamping element has a clamping surface that mates with the inclined pressing surface. The clamping element is fixed to the cantilever by locking screws to clamp the boring blade. The contact surface is in contact with the bottom wall of the blade mounting groove, and the positioning surface abuts against the positioning element.

9. The high-precision machining modular boring bar of claim 8, wherein, The cantilever is also provided with a tool body adjustment mechanism for adjusting the radial position of the boring tool. The tool body adjustment mechanism includes a pressing component and an adjusting component. The adjusting component is threadedly connected to the cantilever, and the pressing component is movably assembled with the cantilever. The boring tool also has an adjusting inclined surface. The pressing component has a pressing inclined surface that cooperates with the adjusting inclined surface. The adjusting inclined surface abuts against the corresponding groove sidewall of the tool mounting groove. When the adjusting component rotates, it pushes the pressing component to move, thereby pushing the boring tool to move radially along the corresponding tool body.

10. The high-precision machining modular boring bar for weight reduction according to claim 9, characterized in that, The dynamic balancing structure is a groove formed on the corresponding cantilever, and the groove depth is different on different cantilevers; the adjusting component and the pressing component on the cantilever with the dynamic balancing structure are inserted into the cantilever from one side of the groove.

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