A special device for variable angle cutting tools in CNC lathe internal machining.

Abstract

This utility model discloses a special device for variable angle cutting tools in CNC lathe internal cavity machining, belonging to the field of CNC machine tool machining technology. It includes a body, a rotating sleeve, a locking screw, and a locking set screw. The body is made of high-strength alloy steel, with an outer diameter of φ80 that matches the inner hole of a standard tool holder on a CNC lathe. Inside, a rotating sleeve is provided that precisely matches the inner arc of the body. The rotating sleeve can rotate within the body, and its stability within the body is limited by a concentric circle structure. A through hole inside the rotating sleeve is used to install a standard tool holder. The locking screw is threaded into the rotating sleeve to lock the standard tool holder. By adjusting the tool holder to the machining angle, the locking set screw locks the rotating sleeve in a fixed position within the body, preventing tool holder angular drift during machining. This utility model is suitable for machining the internal cavities of various products under confined space conditions, achieving good tool interchangeability and economy, while also providing high machining accuracy and reduced manufacturing costs.

Description

Technical Field

[0001] This utility model relates to the field of CNC machine tool processing technology, specifically a special device for variable angle turning of workpieces with narrow openings, large curvature arc-shaped inner cavities and deep cavity structures, especially suitable for high-precision inner cavity turning of tank and cylindrical products. Background Technology

[0002] Currently, the internal cavity machining of conventional through-hole products is generally completed using standard cutting tools. The internal cavities of these workpieces are mostly simple cylindrical surfaces with a moderate depth-to-diameter ratio, and standard cutting tools can meet the machining requirements. However, for new types of blind-hole structures such as conical workpieces (e.g.... Figure 1 Its internal cavity presents the following technical challenges:

[0003] 1) Structural complexity: The inner cavity has a narrow opening, a large radius of curvature, and is deep, requiring high machining precision;

[0004] 2) Machining limitations: Standard cutting tools cannot adapt to the curved surface contours of irregular internal cavities, especially under conditions of extremely large depth-to-diameter ratio, interference occurs;

[0005] 3) Deficiencies of existing non-standard cutting tools: Currently, gooseneck non-standard cutting tools (such as...) are used. Figure 2 ① Insufficient rigidity - Excessive tool overhang leads to vibration during machining, resulting in poor surface quality consistency; ② Fixed angle - Inability to flexibly adjust cutting angles makes it difficult to adapt to machining requirements of cavities with different curvatures, resulting in poor versatility; ③ High installation accuracy - Difficulty in adjusting tool center height affects machining accuracy and tool life; ④ Poor economy: Low interchangeability and short tool life make it difficult to meet the needs of mass production.

[0006] To overcome the aforementioned technical challenges, it is urgent to design a universal tooling device that meets the following requirements: standard tools can be used in confined spaces (narrow openings, large curvatures, deep cavities), and the cutting angle can be adjusted according to machining requirements; rigidity and vibration consistency can be improved to ensure consistent machining quality; it can be adapted to various new types of conical workpieces to reduce manufacturing costs; and tool replacement is convenient and labor intensity is low. Summary of the Invention

[0007] (I) Purpose of the Invention

[0008] The purpose of this invention is to provide a special device for variable angle of CNC lathe internal cavity machining tools, which solves the problems of fixed angle, poor rigidity, and insufficient interchangeability of gooseneck non-standard tools in the prior art, as well as the problems of standard tools being unable to be used due to interference when machining narrow-mouth, large-curvature, and deep-cavity structures.

[0009] (II) Technical Solution

[0010] A special device for variable angle machining tools in CNC lathe cavities, the structure of which is as follows: Figure 3 As shown, it includes: a body, a rotating sleeve, a locking screw, and a locking set screw. The body 1 is made of high-strength alloy steel, with an outer diameter of φ80 that matches the inner hole of a standard tool holder on a CNC lathe. Inside, there is a rotating sleeve 2 that precisely matches the inner arc of the body 1. The rotating sleeve 2 can rotate within the body 1, and its stability within the body 1 is limited by a concentric circle structure. An internal through hole in the rotating sleeve 2 is used to install a standard tool holder. The locking screw 3 is threaded into the rotating sleeve to lock the standard tool holder in place. By adjusting the tool holder to the machining angle, the locking set screw 4 locks the rotating sleeve 2 in a fixed position within the body 1, preventing angular drift of the tool holder during machining.

[0011] The variable angle range is ±15°. In designing this range, considering the large cutting forces during internal cavity machining, the use of a boring bar effectively reduces issues such as tool vibration, tool breakage, and reachability. The inner diameter of the CNC lathe's constant tool holder, φ80, is chosen as the application basis to maximize the diameter of the boring bar. Based on the inner diameter of the tool holder, the outer diameter of the main body, φ80, is determined. The design is then developed using this dimension, and utilizing the principle of concentric circle mechanisms, the design results in an reachable angle range of ±15° for the boring bar as it rotates with the sleeve.

[0012] (III) Effective Returns

[0013] The beneficial effects of this utility model are:

[0014] 1) High versatility: It is compatible with standard boring bar holders with a diameter of φ25 and can machine complex internal cavities with throat diameter D1 / inner diameter D2≥3), large depth-to-diameter ratio (L / D≥5), and small radius of curvature (R≤2d) (i.e. large arc curvature), replacing gooseneck non-standard tools;

[0015] 2) Increased rigidity: The length-to-diameter ratio of the standard boring bar is 5, while that of the gooseneck non-standard tool is 6, resulting in a 70% reduction in vibration compared to the gooseneck non-standard tool (measured Ra≤1.6μm);

[0016] 3) Efficiency optimization: Tool change time is reduced from 15 minutes (for gooseneck non-standard tools) to 1 minute (only standard boring tool inserts need to be replaced);

[0017] 4) Cost savings: The cost per tool is reduced by 60%, making it suitable for mass production (>5000 pieces / batch). Attached image description:

[0018] Figure 1 This is a schematic diagram of a cone-shaped product in the existing technology.

[0019] Figure 2 This is a schematic diagram of an existing gooseneck non-standard cutting tool.

[0020] Figure 3 This is a schematic diagram of the components of the special device of this utility model;

[0021] Wherein: 1-body, 2-rotating sleeve, 3-locking screw, 4-locking set screw;

[0022] Figure 4 This is an assembly drawing of the special device for this utility model;

[0023] Figure 5 This is a schematic diagram of the rotating sleeve and the concentric circle design structure of the main body of this utility model.

[0024] Figure 6 This is a schematic diagram showing the use of the extreme position 1 of the special device of this utility model;

[0025] Figure 7 This is a schematic diagram of the extreme position 2 of the special device of this utility model. Detailed Implementation

[0026] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0027] This utility model is assembled and used (e.g.) Figure 4 The standard tool holder is installed in a special device. Usage steps:

[0028] 1) Tool installation ① Place the rotating sleeve 2 inside the body 1; ② Insert the standard tool holder (diameter φ25mm) into the inner hole of the rotating sleeve 2; ③ Tighten the M8 locking screw 3 with an Allen wrench to fix the standard tool holder inside the rotating sleeve 2; ④ Check the tool holder extension length to ensure that it meets the machining depth requirements.

[0029] 2) Angle Adjustment ① Adjust the initial angle of the rotating sleeve assembly according to the machining cavity size; ② Tighten the M16 locking set screw 4 with an Allen wrench to initially fix the position of the rotating sleeve 2 and the tool in the body 1; ③ Place the special device assembly in the φ80 standard tool holder of the machine tool and fix the special device assembly with the tool holder screw; ④ Loosen the M16 locking set screw 4 according to the machining cavity size, finely adjust the angle of the rotating sleeve assembly to the optimal position, and tighten the M16 locking set screw 4 to the specified torque.

[0030] In this embodiment of the invention, the tool holder is a standard tool holder, and the insert mounted on the tool head is a standard CNC insert. Installation and replacement are flexible, reducing labor intensity. Appropriate inserts and cutting parameters can be selected according to the material being machined. The design utilizes a rotating sleeve and a concentric circle structure for the main body, such as... Figure 5 As shown, the rotating sleeve can rotate within the body to its limit position, as shown in the figure. Figure 6 , 7 As shown, the standard tool rotation angle range can reach ±15°, enabling multi-angle and multi-product machining with standard tools.

[0031] This utility model provides a special device for variable angle of cutting tool for internal cavity machining on CNC lathe. It belongs to the field of mechanical processing technology and can be applied to the internal cavity machining of various products under confined space conditions (narrow inner cavity opening, large inner diameter arc curvature, and deep inner cavity). It achieves good tool interchangeability and economy, and has high machining accuracy and reduced manufacturing cost.

[0032] This utility model provides a special variable angle device for machining internal cavities on CNC lathes, which is especially suitable for blind hole workpieces (such as bottle-shaped and can-shaped workpieces) with small opening diameter (throat diameter D1 / inner diameter D2≥3), large depth-to-diameter ratio (L / D≥5), and small radius of curvature (R≤2d) (i.e., large arc curvature), thereby improving machining adaptability and efficiency.

Claims

1. A special device for variable angle of a tool for machining the inner cavity of a numerically controlled lathe, characterized in that, Includes the main body, rotating sleeve, locking screw, and locking set screw; The body is matched with the inner hole of the standard tool holder of the CNC lathe; The main body has a rotating sleeve that matches the inner arc of the main body. The rotating sleeve and the main body are designed with concentric circles. The rotating sleeve rotates within the main body, and the concentric circle structure restricts the stability of the rotating sleeve within the main body. The rotating sleeve has a through hole for installing a standard tool holder. The locking screw (3) is threaded into the rotating sleeve to lock the standard tool holder. The locking set screw (4) is used to lock the rotating sleeve (2) in the fixed position inside the body (1). The fixed position is the position where the tool holder is rotated to the machining angle to prevent the tool holder from drifting during machining.

2. The variable angle device for special use of a tool for internal cavity machining of a CNC lathe according to claim 1, characterized in that, The main body (1) is made of high-strength alloy steel.

3. The variable angle device for special use of a tool for internal cavity machining of a CNC lathe according to claim 1, characterized in that, The outer diameter of the body is φ80.

4. The variable angle device for special use of a tool for internal cavity machining of a CNC lathe according to claim 1, characterized in that, The body can rotate within a range of ±15° with the rotating sleeve.

5. The variable angle device for special use of a tool for internal cavity machining of a CNC lathe according to claim 1, characterized in that, The special device is compatible with a standard boring bar holder with a diameter of φ25.

6. The variable angle device for special purpose of internal cavity machining tool of a CNC lathe according to claim 1, characterized in that, The specialized device is suitable for use in the internal cavity of blind hole type workpieces.

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