Stepless variable diameter forming tool and machine tool

Abstract

The application discloses a stepless variable-diameter forming tool and a machine tool, which comprise a top cover, a base which is surrounded by the top cover to form a containing cavity, a stepless variable-diameter driving mechanism which is arranged in the containing cavity, a tool seat which is arranged on the outer circumference of the base, and a tool which is mounted on the tool seat, a plurality of the tool seats are uniformly and spacedly arranged along the circumferential direction of the base, and the plurality of the tool seats are driven by the stepless variable-diameter driving mechanism to synchronously stretch and shrink along the radial direction of the base; the stepless variable-diameter forming tool of the application drives all the tool seats to synchronously stretch and shrink along the radial direction of the base through the stepless variable-diameter driving mechanism, so that the stepless change of the machining radius of the blade is realized, the tool has high adaptability, and can meet the machining of a complex variable-curvature cavity.

Description

Technical Field

[0001] This invention relates to the field of machining equipment technology, and in particular, to a continuously variable diameter forming tool. Furthermore, this invention also relates to a machine tool comprising the aforementioned continuously variable diameter forming tool. Background Technology

[0002] In machining, open planes are typically machined using a standard face milling cutter, completing the machining process through multiple reciprocating strokes of the same or different paths. However, some product parts require machining planes with varying radial curvatures due to structural requirements. For example, machining... Figure 1 As shown, when the diameter of the machining tool is greater than the minimum curvature of the radial cavity, overcutting will occur on the part. When the difference between the diameter of the machining tool and the minimum curvature of the radial cavity is significant, machining time will increase, resulting in low production efficiency. This is especially true for undercut variable curvature workpieces, such as... Figure 2 As shown, the diameter of the machining tool must be less than the minimum radial curvature of the workpiece, while ensuring that the tool holder does not collide with the undercut wall.

[0003] Currently, the machining of workpieces with radially variable curvature generally involves changing to tools of different diameters. This method increases tool costs and lacks adaptability. Some solutions, such as Chinese patent CN108672764A, disclose an adaptive support boring device with radially extendable tools. This device can accommodate changes in the radial dimension of the tool, but it can only machine hole features and cannot machine complex cavities with variable curvature. Summary of the Invention

[0004] This invention provides a continuously variable diameter forming tool and machine tool to solve the technical problem that existing tools are not adaptable and cannot meet the processing requirements of complex variable curvature cavities.

[0005] According to one aspect of the present invention, a continuously variable diameter forming tool is provided, comprising a top cover, a base that surrounds the top cover to form a receiving cavity, a continuously variable diameter driving mechanism disposed in the receiving cavity, a tool holder disposed on the outer circumference of the base, and a tool mounted on the tool holder, wherein a plurality of tool holders are evenly spaced along the circumferential direction of the base, and the plurality of tool holders are driven by the continuously variable diameter driving mechanism to synchronously extend and retract along the radial direction of the base.

[0006] Furthermore, the continuously variable diameter drive mechanism includes a telescopic transmission assembly for driving the synchronous extension and retraction of multiple tool holders and an adjustment transmission assembly for driving the telescopic transmission assembly to operate. The adjustment transmission assembly is connected to the telescopic transmission assembly via a spindle, and the spindle is coaxially arranged with the base.

[0007] Further, the telescopic transmission assembly comprises a multi-arm transmission frame connected with the mandrel, a first sliding block rotatably arranged on a free end of the multi-arm transmission frame, a connecting plate in sliding connection with the first sliding block, a second sliding block rotatably arranged on a first end of the connecting plate, and a third sliding block rotatably arranged on a second end of the connecting plate, the third sliding block being fixedly connected with the tool holder, the multi-arm transmission frame comprises a plurality of transmission arms connected with each other, the included angle between any two adjacent transmission arms is equal, the mandrel is coaxially arranged with the axis line of the multi-arm transmission frame, the base is provided with a second sliding groove matched with the second sliding block and a third sliding groove matched with the third sliding block, the third sliding groove is arranged along the radial direction of the base, and the transmission arms, the first sliding block, the connecting plate, the second sliding block, the second sliding groove, the third sliding block, the third sliding groove and the tool holder are arranged in one-to-one correspondence.

[0008] Further, a sleeve for limiting the axial position of the tool holder on the base is arranged on the base.

[0009] Further, the base is provided with threaded holes, screws for locking the tool holder are arranged in the threaded holes, and a plurality of the threaded holes are arranged along the length direction of the third sliding groove.

[0010] Further, the first sliding block and the connecting plate are in sliding connection through a dovetail groove structure.

[0011] Further, the adjusting transmission assembly comprises a sleeve ring, a worm and a worm wheel, a plurality of sleeve rings are arranged on the top cover at intervals, the two ends of the worm are rotatably connected with the corresponding sleeve rings, and the worm wheel is installed on the mandrel and is in meshing connection with the worm.

[0012] Further, a key groove for connecting external driving is arranged on the end face of the worm.

[0013] Further, the tool holder is provided with a scale for indicating the machining radius.

[0014] According to another aspect of the present application, a machine tool comprising the above-mentioned continuously variable radius forming tool is also provided.

[0015] The present application has the following advantages:

[0016] The stepless variable-diameter forming tool of the application installs the blade on the tool seat, and drives all the tool seats to synchronously expand and contract along the radial direction of the base through the stepless variable-diameter driving mechanism, so as to realize the stepless change of the machining radius of the blade. Specifically, the stepless variable-diameter forming tool carries the blade to cut along the fixed line, and when cutting to the variable-curvature position of the cavity, according to the variable-curvature size and the change range, the stepless variable-diameter driving mechanism drives all the tool seats to gradually expand or gradually retract along the radial direction of the base at a preset expansion and contraction speed until the preset distance is reached, thereby realizing the stepless variable-diameter machining of the cavity. The tool has strong adaptability and can meet the machining of complex variable-curvature cavities.

[0017] In addition to the objects, features and advantages described above, the application has other objects, features and advantages. The application will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate preferred embodiments of the application and assist in

[0019] Figure 1 is a sectional view of a variable-diameter cavity in the prior art;

[0020] Figure 2 is a sectional view of a reverse variable-diameter cavity in the prior art;

[0021] Figure 3 is a structural schematic view of the stepless variable-diameter forming tool of the preferred embodiment of the application;

[0022] Figure 4 is a structural schematic view of the adjusting transmission assembly of the preferred embodiment of the application;

[0023] Figure 5 is a structural schematic view of the expansion and contraction transmission assembly of the preferred embodiment of the application;

[0024] Figure 6 is a structural schematic view of the multi-arm transmission frame of the preferred embodiment of the application;

[0025] Figure 7 is a structural schematic view of the maximum machining radius of the tool of the stepless variable-diameter forming tool of the preferred embodiment of the application;

[0026] Figure 8 is a structural schematic view of the minimum machining radius of the tool of the stepless variable-diameter forming tool of the preferred embodiment of the application;

[0027] Figure 9 is a structural schematic view of the diameter change range of the stepless variable-diameter forming tool of the preferred embodiment of the application.

[0028] Legend:

[0029] 1. Top cover; 2. Base; 21. Second slide groove; 22. Third slide groove; 23. Sleeve; 24. Threaded hole; 25. Screw; 3. Tool holder; 4. Tool; 5. Telescopic transmission assembly; 51. Multi-arm transmission frame; 511. Transmission arm; 52. First slider; 53. Connecting plate; 54. Second slider; 55. Third slider; 6. Adjustable transmission assembly; 61. Collar; 62. Worm; 63. Worm wheel; 7. Spindle. Detailed Implementation

[0030] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0031] like Figures 3 to 9 As shown, the continuously variable diameter forming tool of this embodiment includes a top cover 1, a base 2 that surrounds the top cover 1 to form a receiving cavity, a continuously variable diameter driving mechanism arranged in the receiving cavity, a tool holder 3 arranged on the outer circumference of the base 2, and a blade 4 mounted on the tool holder 3. Multiple tool holders 3 are evenly spaced along the circumferential direction of the base 2, and the multiple tool holders 3 are driven by the continuously variable diameter driving mechanism to synchronously extend and retract along the radial direction of the base 2.

[0032] In use, the cutting blade 4 is mounted on the tool holder 3. A continuously variable diameter (CVD) drive mechanism drives all tool holders 3 to synchronously extend and retract along the radial direction of the base 2, thus achieving stepless variation of the cutting blade 4's machining radius. Specifically, the continuously variable diameter forming tool, carrying the cutting blade 4, feeds along a fixed path. When it reaches the position of the cavity's variable curvature, according to the magnitude and amplitude of the curvature, and at a preset extension / retraction speed, the continuously variable diameter drive mechanism drives all tool holders 3 to synchronously and gradually extend or retract along the radial direction of the base 2 until a preset distance is reached, thereby achieving stepless diameter machining of the cavity. The tool is highly adaptable and can meet the machining requirements of complex cavities with variable curvature.

[0033] like Figure 4 As shown, in this embodiment, the continuously variable diameter drive mechanism includes a telescopic transmission assembly 5 for driving multiple tool holders 3 to extend and retract synchronously, and an adjustment transmission assembly 6 for driving the telescopic transmission assembly 5 to operate. The adjustment transmission assembly 6 is connected to the telescopic transmission assembly 5 via a spindle 7, which is coaxially arranged with the base 2. The adjustment transmission assembly 6 drives the telescopic transmission assembly 5 to rotate via the spindle 7, thereby realizing the synchronous extension and retraction of multiple tool holders 3 along the radial direction of the base 2.

[0034] like Figure 5 , Figure 6 Figure 7 , Figure 8 and Figure 9As shown, in the embodiment, the telescopic transmission assembly 5 comprises a multi-arm transmission frame 51 connected with the mandrel 7, a first sliding block 52 rotationally arranged on the free end of the multi-arm transmission frame 51, a connecting plate 53 slidably connected with the first sliding block 52, a second sliding block 54 rotationally arranged on the first end of the connecting plate 53, and a third sliding block 55 rotationally arranged on the second end of the connecting plate 53, the third sliding block 55 being fixedly connected with the tool holder 3, the multi-arm transmission frame 51 comprising a plurality of transmission arms 511 connected with each other, the included angle between any two adjacent transmission arms 511 being equal, the mandrel 7 being coaxially arranged with the axis line of the multi-arm transmission frame 51, the base 2 being provided with a second sliding groove 21 adapted to the second sliding block 54 and a third sliding groove 22 adapted to the third sliding block 55, the third sliding groove 22 being arranged along the radial direction of the base 2, the transmission arm 511, the first sliding block 52, the connecting plate 53, the second sliding block 54, the second sliding groove 21, the third sliding block 55, the third sliding groove 22 and the tool holder 3 being arranged in one-to-one correspondence in groups; specifically, the transmission arm 511 is four, the two adjacent transmission arms 511 being perpendicular to each other, the first sliding block 52 being installed on the free end of the transmission arm 511 through a first pin, the first sliding block 52 being rotatable about the axis line of the first pin, the second sliding block 54 being installed on the first end of the connecting plate 53 through a second pin, the second sliding block 54 being rotatable about the axis line of the second pin, the third sliding block 55 being installed on the second end of the connecting plate 53 through a third pin, the third sliding block 55 being rotatable about the axis line of the third pin, when the mandrel 7 drives the multi-arm transmission frame 51 to rotate, the first sliding block 52 slides along the connecting plate 53, since the first end of the connecting plate 53 is slidably connected with the second sliding groove 21 through the second sliding block 54 and the second end of the connecting plate 53 is slidably connected with the third sliding groove 22 through the third sliding block 55, the first sliding block 52 can drive the connecting plate 53 to move while sliding along the connecting plate 53, so that the tool holder 3 is telescoped along with the third sliding groove 22, the structure is ingenious, all the tool holders 3 can be synchronously driven to change the machining radius, the adaptability of the stepless variable-diameter forming tool is strong, and the machining of the complex variable-curvature cavity can be met. It can be understood that the transmission arm 511 can also be three, five, six or more, the end points of the free ends of the transmission arms 511 can be the vertices of a regular polygon. Alternatively, the center lines of the second sliding groove 21 and the third sliding groove 22 of the same group are perpendicular to each other.

[0035] As shown in Figure 9 , the distance from the axis line of the first pin to the axis line of the mandrel is L1, the spacing between the axis lines of the second pin and the third pin is L2, the included angle between the initial position of the transmission arm 511 and the horizontal direction is a, and the machining radius of the blade 4 is R1, when the transmission arm 511 is rotated by an angle b clockwise, the machining radius of the blade 4 is R2, that is, the free end of the transmission arm 511 is rotated from the point C to the point D, and the position of the blade 4 is from the point A to the point B.

[0036] As shown in Figure 3As shown, in the embodiment, the sleeve 23 is sleeved on the base 2 to limit the axial position of the tool holder 3 along the base 2, the limiting slot corresponding to the tool holder 3 is formed on the sleeve 23, and the limiting slot cooperates with the base 2 to limit the axial position of the tool holder 3, thereby avoiding the shaking of the tool holder 3 during the machining process.

[0037] As shown, Figure 5 As shown, in the embodiment, the threaded holes 24 are formed on the base 2, the screws 25 for locking the tool holder 3 are arranged in the threaded holes 24, and the threaded holes 24 are arranged along the length direction of the third sliding groove 22. After the tool holder 3 is adjusted to the appropriate position, the screws 25 are tightened to apply the axial force to the tool holder 3, the sleeve 23 is clamped with the tool holder 3, the tool holder 3 is stable and reliable during the machining process, and the machining precision is ensured. Alternatively, the threaded holes 24 are arranged along the center line of the third sliding groove 22, so that the gravity center of the stepless variable-diameter forming tool is on the base 2.

[0038] As shown, Figure 6 As shown, the first sliding block 52 and the connecting plate 53 are connected through the dovetail groove structure. In the embodiment, the dovetail-shaped sliding groove is formed on the first sliding block 52, and the dovetail-shaped protrusion is arranged on the connecting plate 53, so as to realize the sliding connection and avoid the loosening of the first sliding block 52 and the connecting plate 53. It can be understood that the dovetail-shaped protrusion is arranged on the first sliding block 52, and the dovetail-shaped sliding groove is formed on the connecting plate 53, so as to realize the sliding connection and avoid the loosening. Alternatively, the first sliding block 52 and the connecting plate 53 can also be connected through the T-shaped sliding groove and the T-shaped sliding block.

[0039] In the embodiment, the adjusting transmission assembly 6 includes the sleeve ring 61, the worm 62, and the worm wheel 63. The sleeve rings 61 are arranged on the top cover 1 at intervals. The two ends of the worm 62 are rotatably connected with the corresponding sleeve rings 61. The worm wheel 63 is installed on the spindle 7 and is engaged with the worm 62. The axial center line of the worm 62 is arranged perpendicularly to the axial center line of the spindle 7. The helix angle of the worm 62 is smaller than the equivalent friction angle of the meshing teeth of the worm wheel. The worm wheel and the worm form self-locking, that is, only when the worm 62 rotates, the worm wheel 63 can be driven to rotate, and the worm wheel 63 cannot drive the worm 62 to rotate, thereby avoiding the radial movement of the blade 4 and ensuring the machining precision. Since the rotation angle of the worm 62 and the worm wheel 63 can be infinitely changed, the movement distance of the tool holder 3 is also infinitely changed, thereby realizing the flexible and stepless change of the machining radius of the tool, and the structure is simple and convenient to adjust. Alternatively, the worm 62 is two, and is arranged symmetrically about the axial center line of the base 2, so that the gravity center of the stepless variable-diameter forming tool is on the base 2, thereby ensuring the static balance of the stepless variable-diameter forming tool and the dynamic balance of the tool rotation. Alternatively, the sleeve ring 61 is a stepped ring, and the limiting blocks are arranged at the two ends of the worm 62 to avoid loosening of the worm 62.

[0040] In the embodiment, a key groove for connecting external driving is arranged on the end surface of the worm 62; a tool is used to rotate the worm 62, so that the machining radius of the blade 4 is quickly adjusted.

[0041] In the embodiment, the scale for indicating the machining radius is arranged on the tool holder 3, the machining radius of the blade 4 can be directly displayed, and the production efficiency is improved.

[0042] A machine tool comprises the stepless variable-diameter forming tool, the structure is simple, the adjustment is convenient, the blade 4 does not need to be disassembled, the worm and gear mechanism and the double-crank slider mechanism can realize the stepless change of the machining radius of the tool, the stepless change of the machining radius of the tool can be realized by rotating the worm, the connection is reliable, the tool holder 15 does not move in the axial direction or the radial direction in the machining process, and the machining precision is ensured.

[0043] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A continuously variable forming tool, characterized in that, it comprises a top cover (1), a base (2) which forms a containing cavity with the top cover (1), a continuously variable drive mechanism arranged in the containing cavity, a tool seat (3) arranged on the outer circumference of the base (2), and a blade (4) mounted on the tool seat (3), a plurality of the tool seats (3) are uniformly spaced along the circumferential direction of the base (2), and a plurality of the tool seats (3) are driven by the continuously variable drive mechanism to synchronously expand and contract along the radial direction of the base (2), the continuously variable drive mechanism comprises an expansion transmission assembly (5) for driving a plurality of the tool seats (3) to synchronously expand and contract, and an adjustment transmission assembly (6) for driving the expansion transmission assembly (5) to operate, the adjustment transmission assembly (6) is connected with the expansion transmission assembly (5) through a mandrel (7), and the mandrel (7) is coaxially arranged with the base (2), the expansion transmission assembly (5) comprises a multi-arm transmission frame (51) connected with the mandrel (7), a first sliding block (52) rotatably arranged on the free end of the multi-arm transmission frame (51), a connecting plate (53) slidably connected with the first sliding block (52), a second sliding block (54) rotatably arranged on the first end of the connecting plate (53), and a third sliding block (55) rotatably arranged on the second end of the connecting plate (53), and the third sliding block (55) is fixedly connected with the tool seat (3), the multi-arm transmission frame (51) comprises a plurality of transmission arms (511) connected with each other, the included angle between any two adjacent transmission arms (511) is equal, and the mandrel (7) is coaxially arranged with the axis line of the multi-arm transmission frame (51), a second sliding groove (21) matched with the second sliding block (54) and a third sliding groove (22) matched with the third sliding block (55) are formed on the base (2), the third sliding groove (22) is arranged along the radial direction of the base (2), and the transmission arm (511), the first sliding block (52), the connecting plate (53), the second sliding block (54), the second sliding groove (21), the third sliding block (55), the third sliding groove (22), and the tool seat (3) are arranged in one-to-one correspondence, the adjustment transmission assembly (6) comprises a sleeve ring (61), a worm (62), and a worm wheel (63), a plurality of the sleeve rings (61) are arranged on the top cover (1) at intervals, the two ends of the worm (62) are rotatably connected with the corresponding sleeve rings (61), and the worm wheel (63) is mounted on the mandrel (7) and is in meshing connection with the worm (62).

2. The continuously variable forming tool according to claim 1, characterized in that, a sleeve (23) for limiting the axial position of the tool seat (3) along the base (2) is arranged on the base (2).

3. The continuously variable forming tool according to claim 2, characterized in that, Threaded holes (24) are formed in the base (2), and screws (25) for locking the tool holder (3) are arranged in the threaded holes (24). A plurality of the threaded holes (24) are arranged along the length direction of the third sliding groove (22).

4. The continuously variable diameter forming tool according to claim 1, characterized in that, The first sliding block (52) and the connecting plate (53) are connected through a dovetail groove structure.

5. The continuously variable diameter forming tool according to claim 1, characterized in that, A key groove for connecting external driving is formed on the end face of the worm (62).

6. The continuously variable diameter forming tool according to claim 1, characterized in that, The tool holder (3) is provided with a scale for indicating the machining radius.

7. A machine tool, characterized by The continuously variable diameter forming tool according to any one of claims 1 to 6.

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