A method and device for precision turning of a heat-conducting copper tube

Abstract

The application discloses a kind of precision turning method and device of heat-conducting copper pipe, device includes rack, center installation stand, multi-station carousel, first precision turning mechanism, second precision turning mechanism and automatic material taking and placing mechanism.First precision turning mechanism and second precision turning mechanism are driven to rotate by power transmission assembly driving turning spindle assembly, and make turning spindle assembly feed along heat-conducting copper pipe axial direction by lifting driving element;Second precision turning mechanism is also provided with oblique tool feed assembly, so that finish turning cutter generates controlled radial tool feed during axial movement.Processing, automatic material taking and placing mechanism places heat-conducting copper pipe in the clamping station of multi-station carousel, after pre-turning by first turning station, it is sent to second turning station to finish turning and chamfering, then it is automatically taken out.The application can reduce coaxiality error caused by repeated clamping of heat-conducting copper pipe, and reduce deformation caused by one-time heavy cutting of thin-walled copper pipe.

Description

Technical Field

[0001] This invention relates to the field of copper tube machining technology, specifically to a method and apparatus for precision turning of thermally conductive copper tubes. Background Technology

[0002] Thermally conductive copper tubes are typically thin-walled tubular components. Their openings and ends require specific end face dimensions, outer diameter dimensions, or chamfered structures to facilitate subsequent sealing, welding, or assembly. Due to the high plasticity of copper and the thin wall thickness of thermally conductive copper tubes, concentrated cutting, unstable clamping positions, or excessively rapid radial feed of the tool during machining can easily cause extrusion deformation, elliptical deformation, or flanging at the tube opening, thereby affecting the end dimensions and coaxiality.

[0003] Existing processing methods mostly employ conventional lathes to complete roughing and finishing in stages. When heat-conducting copper tubes are repeatedly clamped between different equipment or fixtures, the reference position is prone to change, and the perpendicularity between the end face and the tube body axis, as well as the coaxiality between different machined surfaces, is difficult to maintain stably. At the same time, manual loading, alignment, and unloading of each tube causes fluctuations in the production cycle, which is not conducive to continuous processing.

[0004] Furthermore, traditional turning spindles typically require a rotary drive component that moves with the spindle during axial feed, resulting in a large mass of moving parts and impacting lifting response and guiding stability. For finishing tools, using only a single vertical feed method is also not conducive to stable control of radial cutting depth within a short stroke. Therefore, a precision turning device with a heat-conducting copper tube is needed that can sequentially perform staged turning on the same device and coordinate rotary drive, axial feed, and radial feed. Summary of the Invention

[0005] This invention proposes a precision turning method and apparatus for thermally conductive copper tubes, which solves the problems in related technologies such as easy changes in machining datum, large single cutting load, and difficulty in stable control of radial precision turning feed during dispersed machining and repeated clamping of thin-walled thermally conductive copper tubes.

[0006] The technical solution of the present invention is as follows: A precision turning device for heat-conducting copper tubes includes a frame, a central mounting column mounted on the frame, and a multi-station turntable mounted on the frame. The multi-station turntable has workpiece clamping positions for positioning the heat-conducting copper tubes arranged circumferentially. The central mounting column is equipped with a first precision turning mechanism and a second precision turning mechanism, respectively corresponding to different machining positions on the multi-station turntable. The frame is also equipped with an automatic material handling mechanism for transferring the heat-conducting copper tubes between the feeding position and the workpiece clamping position.

[0007] As a preferred embodiment of the present invention, the first precision turning mechanism includes a first power transmission assembly, a first turning spindle assembly, and a first lifting drive component. The first turning spindle assembly is vertically movably mounted on a central mounting column, and the first power transmission assembly is connected to the first turning spindle assembly via a first splined drive shaft, so that the first turning spindle assembly can still obtain stable rotational power during axial movement.

[0008] In a preferred embodiment of the present invention, the second precision turning mechanism includes a second power transmission assembly, a second turning spindle assembly, a second lifting drive component, and a slanted feed assembly. The second turning spindle assembly is vertically movably mounted on a central mounting column, and the second power transmission assembly is connected to the second turning spindle assembly via a second spline drive shaft. The slanted feed assembly is equipped with a finishing tool, which can generate controlled radial displacement when the second turning spindle assembly is axially fed.

[0009] As a preferred embodiment of the present invention, the automatic material handling mechanism includes a copper tube feeding trough, a transfer arm, and a clamping head. The clamping head is located at the end of the transfer arm and is used to vertically feed the heat-conducting copper tube in the copper tube feeding trough into the workpiece clamping position of the multi-station turntable, and to remove the heat-conducting copper tube after processing.

[0010] As a preferred embodiment of the present invention, the present invention also provides a method for precision turning of thermally conductive copper tubes, comprising the steps of automatic feeding and positioning, pre-turning at a first turning station, station transfer, finish turning at a second turning station, and automatic unloading. Pre-turning is used to remove the main allowance and establish machining references. Finish turning completes at least one machining operation of the end face, outer diameter, or chamfer through a combined motion of axial feed and radial feed.

[0011] The working principle and beneficial effects of this invention are as follows: 1. This invention sets up a first precision turning mechanism and a second precision turning mechanism on the same centrally mounted column, and uses a multi-station turntable to sequentially transfer the heat-conducting copper tubes, so that the heat-conducting copper tubes can complete pre-turning and fine turning within the same positioning cycle, reducing the reference offset caused by repeated clamping between different equipment; at the same time, it cooperates with an automatic loading and unloading mechanism to complete the loading and unloading of copper tubes, which can reduce the cycle fluctuation caused by manual alignment of each tube, and distribute the total machining allowance to the two machining stations, reducing the risk of tube end deformation caused by excessive force on thin-walled copper tubes in a single operation.

[0012] 2. The present invention transmits torque between the power transmission assembly and the turning spindle assembly through the first spline drive shaft and the second spline drive shaft, respectively, so that the drive motor and transmission box can be kept in a relatively fixed position, while the turning spindle assembly can be independently raised and lowered axially, thereby reducing the mass of the lifting and lowering moving parts and improving feed stability; the second precision turning mechanism further utilizes the oblique feed assembly to convert the axial displacement into the radial displacement of the finishing tool, so that the tool gradually enters and exits along the constrained continuous path, which is beneficial to stably control the finishing cutting depth. Attached Figure Description

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 This is a first-view schematic diagram of the overall structure of the present invention; Figure 2 This is a second-view schematic diagram of the overall structure of the present invention; Figure 3 This is a third-view schematic diagram of the overall structure of the present invention; Figure 4 A schematic diagram of the assembly structure with the central column, the first precision turning mechanism, and the second precision turning mechanism installed. Figure 5 Schematic diagrams of the first and second precision turning mechanisms; Figure 6 This is a schematic diagram of the second precision turning mechanism; Figure 7 This is a schematic diagram of the first precision turning mechanism.

[0015] In the diagram: 1. Frame; 2. Central mounting column; 3. First precision turning mechanism; 31. First power transmission assembly; 311. First drive motor; 312. First transmission box; 313. First spline drive shaft; 314. First transmission connector; 32. First turning spindle assembly; 321. First spindle housing; 322. First lifting guide rod; 33. First lifting drive component; 331. First lifting connecting seat; 4. Second precision turning mechanism; 41 411. Second power transmission assembly; 412. Second drive motor; 413. Second transmission box; 414. Second spline drive shaft; 42. Second turning spindle assembly; 425. Second spindle housing; 426. Second lifting guide rod; 427. Second tool mounting rod; 43. Second lifting drive component; 44. Inclined feed assembly; 448. Finishing tool; 5. Automatic material handling mechanism; 51. Copper tube feed trough; 52. Transfer swing arm; 53. Clamping and picking head. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] Example like Figures 1 to 3 As shown, a precision turning device for heat-conducting copper tubes in this embodiment includes a frame 1, a central mounting column 2, a first precision turning mechanism 3, a second precision turning mechanism 4, and an automatic loading and unloading mechanism 5. The frame 1 has a support platform at the bottom and a protective mounting section at the top, with a multi-station turntable mounted on the support platform. The multi-station turntable has multiple workpiece clamping positions arranged circumferentially. Each workpiece clamping position is used to maintain the heat-conducting copper tube in a vertical position and allows it to sequentially pass through the loading position, the first turning position, the second turning position, and the unloading position along with the multi-station turntable. The multi-station turntable can be driven intermittently by a servo indexing mechanism. The specific clamping drive structure of the servo indexing mechanism and the workpiece clamping positions can adopt existing indexing plates and elastic sleeve structures.

[0018] like Figure 1 , Figure 2 and Figure 4 As shown, the central mounting column 2 is vertically positioned at or near the center of the multi-station turntable. The central mounting column 2 has a vertically extending mounting surface and a guide surface. The first precision turning mechanism 3 and the second precision turning mechanism 4 are respectively mounted on different sides of the central mounting column 2, and are located above the first and second turning stations of the multi-station turntable. The central mounting column 2 transmits the forces of the two turning mechanisms to the frame 1, while simultaneously allowing the two turning mechanisms to share the same mounting reference.

[0019] like Figure 5 and Figure 7 As shown, the first precision turning mechanism 3 includes a first power transmission assembly 31, a first turning spindle assembly 32, and a first lifting drive component 33. The first power transmission assembly 31 is positioned above the first turning spindle assembly 32 and includes a first drive motor 311, a first transmission box 312, a first spline drive shaft 313, and a first transmission coupling 314. The first drive motor 311 is fixed to the first transmission box 312, and its output torque is transmitted to the first spline drive shaft 313 via the first transmission box 312. The first spline drive shaft 313 is vertically oriented, and its lower end is connected to the rotating spindle of the first turning spindle assembly 32 via the first transmission coupling 314. The first spline drive shaft 313 and its corresponding spline sleeve can slide relative to each other axially, allowing the first turning spindle assembly 32 to maintain rotational transmission during lifting.

[0020] like Figure 7 As shown, the first turning spindle assembly 32 includes a first spindle housing 321 and a first lifting guide rod 322. The first spindle housing 321 contains a bearing assembly for supporting the rotating spindle, and the lower end of the rotating spindle is used to mount a pre-cutting tool. The first lifting guide rod 322 is connected to the first spindle housing 321 and cooperates with a vertical guide structure on the central mounting column 2 to limit the swing of the first turning spindle assembly 32 around a non-machining axis. A first lifting drive 33 is fixed to the central mounting column 2, and the output end of the first lifting drive 33 is connected to the first spindle housing 321 via a first lifting connecting seat 331. When the first lifting drive 33 is activated, the first spindle housing 321, the rotating spindle, and the pre-cutting tool move vertically towards or away from the heat-conducting copper pipe.

[0021] When the first precision turning mechanism 3 is working, the first drive motor 311 first drives the pre-turning tool to reach the set speed, and then the first lifting drive component 33 drives the first turning spindle assembly 32 to move downward. After the pre-turning tool contacts the end of the heat-conducting copper tube to be machined, it removes the main machining allowance at the end and forms the axial reference required for subsequent finishing. After the first turning is completed, the first lifting drive component 33 drives the first turning spindle assembly 32 to rise and reset, and the multi-station turntable then transfers the heat-conducting copper tube to the second turning station.

[0022] like Figure 5 and Figure 6 As shown, the second precision turning mechanism 4 includes a second power transmission assembly 41, a second turning spindle assembly 42, a second lifting drive component 43, and a slanted feed assembly 44. The second power transmission assembly 41 includes a second drive motor 411, a second transmission box 412, and a second splined drive shaft 413. The second drive motor 411 is fixed to the second transmission box 412, and the second splined drive shaft 413 is connected to the output end of the second transmission box 412, transmitting torque to the second turning spindle assembly 42 via a splined sleeve. The second splined drive shaft 413 is vertically arranged, so that the second turning spindle assembly 42 does not need to drive the second drive motor 411 and the second transmission box 412 to move synchronously when it is raised or lowered.

[0023] like Figure 6 As shown, the second turning spindle assembly 42 includes a second spindle housing 421, a second lifting guide rod 422, and a second tool mounting rod 423. The second spindle housing 421 is slidably engaged with the vertical guide structure on the central mounting column 2. The second lifting guide rod 422 is used to improve the anti-sway capability of the second spindle housing 421 during its vertical movement. The second tool mounting rod 423 extends downward from the lower part of the second spindle housing 421 and can rotate and move up and down with the second spindle housing 421. The second lifting drive component 43 is fixed to the central mounting column 2 and connected to the second spindle housing 421, and is used to control the axial machining position of the second turning spindle assembly 42.

[0024] like Figure 6 As shown, the oblique feed assembly 44 is disposed on the lower side of the second turning spindle assembly 42. The oblique feed assembly 44 includes an obliquely extending oblique guide structure and a tool mount that can move along the oblique guide structure. The finishing tool 441 is fixed to the lower part of the tool mount. The extension direction of the oblique guide structure has both vertical and radial components. When the second turning spindle assembly 42 moves towards the machining position, the tool mount is constrained by the oblique guide structure, causing the finishing tool 441 to gradually approach the axis of the heat-conducting copper pipe; when the second turning spindle assembly 42 reverses and resets, the finishing tool 441 moves away from the heat-conducting copper pipe along its original path. By changing the tilt angle of the oblique guide structure or adjusting the initial position of the tool mount, the radial feed rate of the finishing tool 441 can be changed.

[0025] When the second precision turning mechanism 4 is working, the second drive motor 411 drives the second tool mounting rod 423 or its connected rotating component to reach the set speed. The second lifting drive component 43 drives the second turning spindle assembly 42 to feed axially, and the oblique feed component 44 synchronously controls the finishing tool 441 to radially approach the heat-conducting copper tube. The finishing tool 441 performs finishing on the end face, outer cylindrical surface, or tube end chamfer with a cutting load less than that of the pre-turning stage. After reaching the set position, the second lifting drive component 43 drives the second turning spindle assembly 42 to reset, and the finishing tool 441 synchronously retracts radially to avoid scratching the machined surface during the retraction process.

[0026] like Figure 3 As shown, the automatic loading and unloading mechanism 5 is located on one side of the frame 1, including a copper tube feeding trough 51, a transfer arm 52, and a clamping head 53. The copper tube feeding trough 51 is used to arrange the heat-conducting copper tubes to be processed in a set direction and to deliver the foremost heat-conducting copper tube to the loading position. One end of the transfer arm 52 is rotatably or slidably connected to the frame 1, and the other end is equipped with the clamping head 53. The clamping head 53 can be a pneumatic gripper, an elastic gripper, or a tensioning head that mates with the inner hole of the heat-conducting copper tube. After the clamping head 53 clamps the heat-conducting copper tube, the transfer arm 52 transfers the heat-conducting copper tube to the empty workpiece clamping position of the multi-station turntable, and releases it after the heat-conducting copper tube is fixed by the workpiece clamping position.

[0027] The automatic loading and unloading mechanism 5 can also be used for finished product unloading. When the heat-conducting copper tube, which has been precision-machined, rotates to the unloading position along with the multi-station turntable, the transfer arm 52 drives the clamping head 53 to clamp the heat-conducting copper tube. The workpiece clamping position is then released, and the transfer arm 52 then transfers the finished product to the finished product collection position. To avoid interference between the loading and unloading actions, the transfer arm 52 can complete one unloading cycle in the order of unloading the finished product first and then placing the blank, or two clamping positions can be configured to perform unloading and loading respectively.

[0028] The precision turning method of this embodiment includes the following process. First, a thermally conductive copper tube that has been cut to a fixed length is placed into the copper tube feeding groove 51. The clamping head 53 picks up a thermally conductive copper tube and places it into the workpiece clamping position of the multi-station turntable. The workpiece clamping position is positioned and clamped from the outer periphery of the thermally conductive copper tube. The clamping force is sufficient to limit the rotation and axial movement of the thermally conductive copper tube without causing significant deformation of the tube wall.

[0029] Subsequently, the multi-station rotary table delivers the heat-conducting copper tube to the area below the first precision turning mechanism 3. The first drive motor 311 starts, and the first spline drive shaft 313 transmits torque to the first turning spindle assembly 32. The first lifting drive component 33 drives the pre-turning tool axially to approach the heat-conducting copper tube, leveling the tube end face and removing the main excess material. After the pre-turning is completed, the first turning spindle assembly 32 rises and resets, and the multi-station rotary table delivers the heat-conducting copper tube to the area below the second precision turning mechanism 4.

[0030] At the second turning station, the second drive motor 411 drives the second turning spindle assembly 42 to rotate, and the second lifting drive component 43 controls the axial movement of the second turning spindle assembly 42. Guided by the oblique feed component 44, the finishing tool 441 gradually makes radial infeed, performing finishing on the outer circle, end face, or chamfer of the heat-conducting copper tube. After finishing, the second precision turning mechanism 4 resets, and the multi-station turntable delivers the finished product to the material handling position, where it is removed by the automatic material handling mechanism 5. The aforementioned drive motors, lifting drive components, multi-station turntable, and automatic material handling mechanism 5 can be linked by a controller according to a preset timing sequence, and position detection can be achieved through proximity switches, limit switches, or encoders.

[0031] In this embodiment, the first precision turning mechanism 3 undertakes pre-turning, and the second precision turning mechanism 4 undertakes finish turning to reduce the single cutting load. Depending on the actual requirements of the heat-conducting copper tube end structure, the first precision turning mechanism 3 can also be configured as an end-face turning mechanism, and the second precision turning mechanism 4 as an external turning or chamfering mechanism; alternatively, the two mechanisms can be equipped with different shaped tools to complete any two consecutive processes among internal hole trimming, end-face finish turning, external finish turning, and chamfering. The above adjustments do not change the basic structure of the two turning mechanisms' division of labor, spline shaft drive, and oblique feed.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A precision turning device for heat-conducting copper tubes, comprising a frame (1), a central mounting column (2) disposed on the frame (1), and a multi-station turntable disposed on the frame (1), wherein the multi-station turntable is provided with workpiece clamping positions for positioning heat-conducting copper tubes along the circumferential direction, characterized in that: The central mounting column (2) is provided with a first precision turning mechanism (3) and a second precision turning mechanism (4) corresponding to different machining positions of the multi-station turntable. The frame (1) is also provided with an automatic material handling mechanism (5) for transferring the heat-conducting copper tube between the feeding position and the workpiece clamping position. The first precision turning mechanism (3) includes a first power transmission assembly (31), a first turning spindle assembly (32) and a first lifting drive component (33). The first turning spindle assembly (32) is vertically movably mounted on the central mounting column (2). The first power transmission assembly (31) is connected to the first turning spindle via a first spline drive shaft (313). The assembly (32) is driven to transmit torque to the first turning spindle assembly (32) while allowing it to move axially; the second precision turning mechanism (4) includes a second power transmission assembly (41), a second turning spindle assembly (42), a second lifting drive (43), and a slant feed assembly (44). The second turning spindle assembly (42) is movably mounted vertically on the central mounting column (2). The second power transmission assembly (41) is driven to the second turning spindle assembly (42) via a second spline drive shaft (413). The slant feed assembly (44) is provided with a precision turning tool (441) that can move radially relative to the heat-conducting copper tube.

2. The precision turning device for heat-conducting copper tubes according to claim 1, characterized in that: The first power transmission assembly (31) includes a first drive motor (311), a first transmission box (312), a first spline drive shaft (313), and a first transmission connector (314). The first drive motor (311) is mounted on the first transmission box (312). The first spline drive shaft (313) is connected to the output end of the first transmission box (312). The lower end of the first spline drive shaft (313) is connected to the first turning spindle assembly (32) through the first transmission connector (314).

3. The precision turning device for heat-conducting copper tubes according to claim 2, characterized in that: The first turning spindle assembly (32) includes a first spindle housing (321) and a first lifting guide rod (322) connected to the first spindle housing (321). The first lifting guide rod (322) is slidably engaged with the vertical guide structure on the central mounting column (2). The output end of the first lifting drive (33) is connected to the first turning spindle assembly (32) through the first lifting connecting seat (331).

4. The precision turning device for heat-conducting copper tubes according to claim 1, characterized in that: The second power transmission assembly (41) includes a second drive motor (411), a second transmission box (412), and a second spline drive shaft (413). The second drive motor (411) is mounted on the second transmission box (412), and the second spline drive shaft (413) is connected to the output end of the second transmission box (412) and can maintain torque transmission as the second turning spindle assembly (42) rises and falls.

5. The precision turning device for heat-conducting copper tubes according to claim 4, characterized in that: The second turning spindle assembly (42) includes a second spindle housing (421), a second lifting guide rod (422), and a second tool mounting rod (423) extending downward from the second spindle housing (421). The second lifting guide rod (422) is slidably engaged with the vertical guide structure on the central mounting column (2). The output end of the second lifting drive (43) is connected to the second spindle housing (421).

6. The precision turning device for heat-conducting copper tubes according to claim 5, characterized in that: The oblique feed assembly (44) includes an oblique guide structure that is inclined relative to the second spindle housing (421) and a tool mounting seat that slides with the oblique guide structure. The finishing tool (441) is mounted on the tool mounting seat. When the second turning spindle assembly (42) feeds vertically, the tool mounting seat, under the constraint of the oblique guide structure, drives the finishing tool (441) to generate radial displacement toward or away from the axis of the heat-conducting copper tube.

7. The precision turning device for heat-conducting copper tubes according to claim 1, characterized in that: The automatic material handling mechanism (5) includes a copper tube feeding trough (51), a transfer arm (52) that can swing between the copper tube feeding trough (51) and the multi-station turntable, and a clamping head (53) located at the end of the transfer arm (52). The clamping head (53) is used to clamp the heat-conducting copper tube and keep the heat-conducting copper tube in a vertical position.

8. The precision turning device for heat-conducting copper tubes according to claim 1, characterized in that: The multi-station turntable can rotate intermittently. The workpiece clamping position includes at least a loading station, a first turning station, and a second turning station that pass through the automatic loading and unloading mechanism (5), the first precision turning mechanism (3), and the second precision turning mechanism (4) in sequence. Each workpiece clamping position is provided with an elastic clamping sleeve for circumferentially limiting the workpiece from the outer periphery of the heat-conducting copper tube.

9. A method for precision turning of a heat-conducting copper tube using the apparatus described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. Arrange the heat-conducting copper tubes to be processed in the copper tube feeding groove (51), and use the transfer swing arm (52) to drive the clamping head (53) to clamp the heat-conducting copper tubes and vertically place the heat-conducting copper tubes into the workpiece clamping position of the multi-station turntable. S2. The multi-station turntable transfers the heat-conducting copper tube to the first turning station. The first drive motor (311) drives the first turning spindle assembly (32) to rotate through the first transmission box (312) and the first spline transmission shaft (313). The first lifting drive component (33) drives the first turning spindle assembly (32) to feed along the axial direction of the heat-conducting copper tube so as to pre-turn the end of the heat-conducting copper tube to be processed. S3. The multi-station turntable transfers the pre-machined heat-conducting copper tube to the second machining station. The second drive motor (411) drives the second machining spindle assembly (42) to rotate through the second transmission box (412) and the second spline transmission shaft (413). The second lifting drive component (43) drives the second machining spindle assembly (42) to feed axially. At the same time, the oblique feed assembly (44) drives the finishing tool (441) to feed radially to complete the finishing machining. S4. The second turning spindle assembly (42) and the finishing turning tool (441) retract, and the multi-station turntable transfers the processed heat-conducting copper tube to the material pick-up position, where it is picked up by the automatic material pick-up and unpick-up mechanism (5).

10. A method for precision machining of a heat-conducting copper tube according to claim 9, characterized in that: The pre-turning is used to remove the main machining allowance of the heat-conducting copper tube to be machined and to form an axial positioning reference. The fine turning is used to shape at least one of the end face, outer circular surface and pipe opening chamfer of the heat-conducting copper tube. During the fine turning process, the second turning spindle assembly (42) is first made to establish a stable speed, and then the fine turning tool (441) is gradually brought into contact with the heat-conducting copper tube through the oblique feed assembly (44). After reaching the set machining position, the fine turning tool (441) is withdrawn along the original path.

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