Deep hole machining lathe integrated damping tool

Abstract

This invention discloses a deep-hole machining tool with integrated turning and grinding damping, belonging to the field of machining tools. The tool includes a tool holder body, with a quick-change turning head holder and a quick-change grinding head detachably mounted at the front end. The grinding head is connected to an electric spindle inside the tool holder body via a drive shaft. The turning head holder and the grinding head are designed for alternating use in the same clamping state. A damping unit is also provided inside the tool holder body. This damping unit includes a mass block suspended and supported by an elastic rubber ring and a damping medium covering the mass block, used for broadband damping and vibration reduction of the drive shaft from 200Hz to 5000Hz. This invention eliminates coaxiality errors caused by multiple clampings through integrated turning and grinding and a single clamping process. Combined with a broadband damping and vibration reduction mechanism, it effectively suppresses low-frequency turning and high-frequency grinding chatter, significantly improving the accuracy, surface quality, and efficiency of deep-hole machining. It is suitable for deep-hole machining of high-aspect-ratio materials such as high-temperature alloys and titanium alloys.

Description

Technical Field

[0001] This invention relates to the field of machining tool technology, specifically to a turning and grinding integrated damping and vibration reduction tool for deep hole machining. Background Technology

[0002] Deep hole machining (length / diameter ratio L / D ≥ 7:1) is a core process in aerospace, energy equipment, and automotive manufacturing. While current mainstream damping and vibration-damping toolholders can suppress low-frequency vibrations (<2000Hz) during turning through heavy metal filling or hydraulic damping technology, achieving a surface roughness of Ra 0.4μm, they still face a dual bottleneck in deep hole machining of difficult-to-machine materials (such as GH4169 high-temperature alloy and titanium alloy) with high length / diameter ratios (L / D ≥ 14:1): First, the insufficient rigidity of long overhanging toolholders easily induces severe vibrations. Traditional toolholders have limited ability to suppress high-frequency chatter (3000-5000Hz) during grinding, leading to surface ripples, microcracks, and even part scrap. Second, the separation of turning and grinding processes requires multiple clamping operations, resulting in coaxiality errors exceeding ±0.05mm and a reduction in machining efficiency of over 40%.

[0003] In existing technologies, some cutting tools improve rigidity by increasing the diameter of the tool holder or using cemented carbide materials, but the effect is limited by the workpiece hole diameter. Other technologies reduce vibration by incorporating a single damping rubber or hydraulic chamber inside the tool holder, but their vibration reduction frequency range is narrow and cannot simultaneously cover the low frequencies of turning and the high frequencies of grinding. Furthermore, turning tools and grinding wheels typically need to be clamped separately on different machine tools or repeatedly disassembled and reassembled on the same machine tool, which is not only inefficient but also makes it difficult to guarantee the coaxiality requirements for deep hole machining due to changes in clamping references.

[0004] Therefore, there is an urgent need for a deep hole machining tool that can simultaneously solve the problems of broadband vibration suppression and the integration of turning and grinding processes, and has a compact structure that is easy to use on existing machine tools. Summary of the Invention

[0005] In view of the above situation and to overcome the current technical defects, the present invention provides a deep hole machining turning and grinding integrated damping tool, which aims to solve the problems of narrow vibration suppression range, poor accuracy and low machining efficiency caused by process separation in the existing technology.

[0006] The technical solution adopted by this invention is as follows: This solution provides a deep hole machining turning and grinding integrated damping tool, including a tool holder body. A quick-change turning tool head holder is detachably installed at the front end of the tool holder body. A quick-change grinding wheel head is detachably installed at the front end of the tool holder body and is connected to an electric spindle inside the tool holder body via a transmission shaft. The quick-change turning tool head holder and the quick-change grinding wheel head are configured to be used alternately in the same clamping state. A damping unit is also provided inside the tool holder body. The damping unit includes a mass block suspended and supported by an elastic rubber ring and a damping medium covering the mass block, used for broadband damping and vibration reduction of the transmission shaft.

[0007] Furthermore, the mass block is a tungsten-nickel-iron alloy mass block, and the damping medium is liquid polysiloxane damping oil.

[0008] Furthermore, the quick-change turning tool holder and the quick-change grinding wheel head are detachably connected via a clamping quick-change tool holder and an open bushing mechanism, respectively.

[0009] Furthermore, the maximum speed of the electric spindle is not less than 10,000 rpm, which is used to drive the quick-change grinding head to achieve a grinding wheel linear speed of not less than 60 m / s.

[0010] Furthermore, the main body of the tool holder is formed by vacuum heat treatment of SKD61 steel, and a 40Cr gradient treatment layer is formed on its outer surface.

[0011] Furthermore, the 40Cr gradient treatment layer includes a tempering layer, a carburizing and quenching layer, and an ion nitriding layer distributed sequentially from the inside out.

[0012] Furthermore, the rear end of the tool holder body is provided with a CAPTO modular interface, and the clamping length of the tool holder body is not less than 4 times its diameter, so as to achieve stable cutting with a length-to-diameter ratio of at least 14:1.

[0013] Furthermore, the effective vibration reduction frequency range of the damping unit is 200Hz to 5000Hz; the main body of the tool holder is a hollow structure, and a front damping washer, a rear damping washer, and damping powder filled in the inner cavity are also provided inside.

[0014] Furthermore, the quick-change grinding wheel head and the quick-change turning tool head seat are integrated axially on the same reference positioning surface of the tool holder body, so that turning and grinding processes share a unified clamping reference, and the machining coaxiality is no greater than Φ0.02mm.

[0015] Furthermore, when the ratio of the overhang length of the tool holder body to its diameter is not less than 14:1, its radial static stiffness sag value is not greater than ±0.005mm.

[0016] The beneficial effects achieved by the present invention using the above structure are as follows:

[0017] 1. A damping unit consisting of an elastic rubber ring, a tungsten-nickel-iron alloy mass block, and liquid polysiloxane damping oil is used to achieve wide-frequency vibration reduction in the range of 200Hz-5000Hz, covering low-frequency turning and high-frequency grinding chatter, and significantly suppressing surface ripples and micro-cracks.

[0018] 2. With the clamping quick-change tool holder and open bushing mechanism, turning and grinding functions can be quickly switched in the same clamping state, with a switching time of less than 3 minutes, completely eliminating the coaxiality error caused by multiple clamping, and the machining coaxiality is ≤ Φ0.02mm.

[0019] 3. The SKD61 vacuum heat treatment + 40Cr gradient treatment layer is adopted. The combination structure of tempering layer, carburizing and quenching layer and ion nitriding layer makes the 14-times-diameter overhang sag value ≤ ±0.005mm, which significantly improves the rigidity of long overhang processing.

[0020] 4. In the processing of typical parts such as high-temperature alloys for aviation and hydraulic cylinders for new energy vehicles, the efficiency is increased by 40% to 65%, the surface roughness reaches Ra0.1 to 0.2μm, and the scrap rate is reduced to below 5%.

[0021] 5. Modular design reduces tool types and inventory costs by 60%, and the damping medium and materials meet environmental protection requirements. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a schematic diagram of the overall structure of the deep hole machining turning and grinding integrated damping tool of the present invention.

[0024] The components include: 1. Quick-change grinding head, 2. Damping unit, 3. Drive shaft, 4. Electric spindle, 5. Tool holder body, and 6. Quick-change turning tool holder. Detailed Implementation

[0025] 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. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively. Example 1:

[0027] Reference Figure 1 As shown, this embodiment provides a deep hole machining turning and grinding integrated damping tool. This tool is used for deep hole machining of high temperature alloy (such as GH4169) workpieces on CNC turning centers or turning and milling composite machining centers.

[0028] The tool holder body 5 is slender and cylindrical in shape, formed by vacuum heat treatment of SKD61 steel. Its outer surface is covered with a 40Cr gradient treatment layer, which includes a tempering layer, a carburizing and quenching layer and an ion nitriding layer distributed from the inside to the outside to enhance surface hardness and fatigue resistance. The rear end of the tool holder body 5 is equipped with a CAPTO modular interface, with a clamping length of 4.5 times the diameter of the tool holder, so as to maintain sufficient static stiffness when machining deep holes with a length-to-diameter ratio of 14:1. The measured radial static stiffness sag value is ±0.003mm.

[0029] A quick-change turning head holder 6 is detachably mounted on the front end of the tool holder body 5. At the same time, a quick-change grinding wheel head 1 is detachably mounted on the front end of the tool holder body 5 through an open bushing mechanism. The quick-change grinding wheel head 1 is connected to the electric spindle 4 inside the tool holder body 5 through a drive shaft 3. The maximum speed of the electric spindle 4 is 12,000 rpm, which can drive the grinding wheel to achieve a linear speed of 65 m / s.

[0030] The tool holder body 5 has a hollow structure, and a damping unit 2 is installed inside. The damping unit 2 includes a tungsten-nickel-iron alloy mass block suspended and supported by an elastic rubber ring and liquid polysiloxane damping oil covering it. This combined structure has excellent vibration energy dissipation capability in the range of 200Hz-5000Hz and can effectively absorb the wide frequency vibration transmitted by the drive shaft 3. In addition, the tool holder body 5 is also equipped with a front damping washer, a rear damping washer, and damping powder filled in the inner cavity to further enhance the vibration reduction effect.

[0031] The quick-change grinding head 1 and the quick-change turning tool holder 6 are integrated axially on the same reference positioning surface of the tool holder body 5, so that turning and grinding processes share a unified clamping reference. Actual measurements show that, with this structure, the coaxiality of the deep hole machined after switching between turning and grinding is no greater than Φ0.01mm. Example 2

[0032] This embodiment is basically the same as embodiment 1, except that the position of the mass block of the damping unit 2 and the filling density of the damping powder can be pre-tuned according to the main vibration frequency of the processed material. For deep hole processing of titanium alloy (TC4) (L / D=16:1), the vibration main frequency is determined to be 3800Hz through finite element analysis. The position of the mass block is adjusted 2mm towards the front end of the tool holder, and the filling rate of the damping powder is increased to 85%. The measured vibration amplitude is reduced by 72%, and the surface roughness is reduced from Ra0.35μm to Ra0.12μm.

[0033] Performance verification

[0034] The cutting tool of Embodiment 1 of this invention (hereinafter referred to as "the cutting tool of this invention") was compared with two control tools. Control tool 1: a traditional heavy metal filled damping turning tool holder (turning function only); control tool 2: an imported hydraulic damping turning and grinding integrated tool holder (non-quick-change structure, requiring secondary clamping). The test workpiece material was GH4169 high-temperature alloy, with a length-to-diameter ratio of L / D=15:1 and a hole diameter of Φ25mm. Machining steps: rough turning (cutting speed 120m / min, feed 0.15mm / rev, depth of cut 1.5mm) + finish grinding (grinding wheel linear speed 65m / s, workpiece speed 20m / min, radial micro-feed 0.01mm / pass).

[0035] The test results are as follows:

[0036]

[0037] The above data shows that the coaxiality of the tool of the present invention is improved to Φ0.008mm in a single clamping, the surface roughness reaches Ra0.13μm, the single-piece machining time is shortened by 65% ​​compared with the control tool 2, and the vibration amplitude during turning and grinding is controlled below 1.1μm, which is much lower than that of the control tool. At the same time, after machining 100 parts continuously, no micro-cracks caused by vibration appeared, and the scrap rate was reduced from 40% of the control tool 2 to 4%.

[0038] Industrial applicability

[0039] The deep-hole machining integrated turning and grinding damping tool provided by this invention can be widely used in the precision deep-hole machining of key components such as aero-engine turbine disks, missile casings, hydraulic cylinders for new energy vehicles, and valve bodies for nuclear power plants. It is especially suitable for high-efficiency, high-precision machining scenarios involving high aspect ratios (≥14:1) and difficult-to-machine materials (high-temperature alloys, titanium alloys, etc.). This invention features a compact structure, quick tool changing, and significant vibration reduction. It can be directly adapted to existing CNC lathes and turning-milling machining centers without requiring machine tool modifications, and has extremely high industrial practical value and market prospects.

[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. 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.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, material, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, material, or apparatus.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A deep hole machining turning and grinding integrated damping tool, comprising a tool holder body (5), characterized in that: The front end of the tool holder body (5) is detachably mounted with a quick-change turning tool head seat (6), and the quick-change grinding wheel head (1) is detachably mounted on the front end of the tool holder body (5) and connected to the electric spindle (4) inside the tool holder body (5) via a transmission shaft (3). The quick-change turning tool head seat (6) and the quick-change grinding wheel head (1) are configured to be used alternately in the same clamping state. The tool holder body (5) is also provided with a damping unit (2). The damping unit (2) includes a mass block suspended and supported by an elastic rubber ring and a damping medium covering the mass block, which is used to perform wide-frequency damping and vibration reduction on the transmission shaft (3).

2. The deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: The mass block is a tungsten-nickel-iron alloy mass block, and the damping medium is liquid polysiloxane damping oil.

3. The deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: The quick-change turning tool holder (6) and the quick-change grinding wheel head (1) are detachably connected by a clamping quick-change tool holder and an open bushing mechanism, respectively.

4. The deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: The maximum speed of the electric spindle (4) is not less than 10,000 rpm, which is used to drive the quick-change grinding head (1) to achieve a grinding wheel linear speed of not less than 60 m / s.

5. The deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: The main body of the tool holder (5) is formed by vacuum heat treatment of SKD61 steel and a 40Cr gradient treatment layer is formed on its outer surface.

6. The deep hole machining turning and grinding integrated damping tool according to claim 5, characterized in that: The 40Cr gradient treatment layer includes a tempering layer, a carburizing and quenching layer, and an ion nitriding layer distributed sequentially from the inside out.

7. The deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: The tool holder body (5) is provided with a CAPTO modular interface at its rear end, and the clamping length of the tool holder body (5) is not less than 4 times its diameter, so as to achieve stable cutting with a length-to-diameter ratio of at least 14:

1.

8. The integrated turning and grinding damping tool for deep hole machining according to claim 1, characterized in that: The effective vibration reduction frequency range of the damping unit (2) is 200Hz to 5000Hz; the main body of the tool bar (5) is a hollow structure, and a front damping washer, a rear damping washer and damping powder filled in the inner cavity are also provided inside.

9. A deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: The quick-change grinding head (1) and the quick-change turning tool holder (6) are integrated axially on the same reference positioning surface of the tool holder body (5), so that turning and grinding share a unified clamping reference and the machining coaxiality is no greater than Φ0.02mm.

10. A deep hole machining turning and grinding integrated damping tool according to claim 1, characterized in that: When the ratio of the overhang length to the diameter of the main body (5) of the tool holder is not less than 14:1, its radial static stiffness sag value is not greater than ±0.005mm.

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