A variable frequency ultrasonic vibration lubrication micro-texture turning device

Abstract

The variable-frequency ultrasonic vibration lubricated micro-textured turning device of the present invention comprises an ultrasonic vibration unit, a control unit, a turning tool assembly, a height-adjustable bracket, and a large carriage. The turning tool assembly and bracket are mounted on the large carriage, and the ultrasonic vibration unit is supported on the bracket. The device comprises a lubricating liquid supply, an ultrasonic generator, a transducer, and a nozzle. The ultrasonic generator drives the nozzle via the transducer to vibrate and pour lubricating liquid from the lubricating liquid supply unit through the nozzle into the cutting area of ​​the turning tool assembly. The control unit collects cutting force signals from the turning tool assembly and controls the transducer to pour lubricating liquid based on the cutting force signals. Beneficial Effect: During the machining process, by adjusting the ultrasonic vibration frequency and amplitude and adjusting the lathe cutting fluid supply device, the device solves the problem of aggravated debris discharge from the micro-textured pits of the turning tool in multiple ways, provides continuous high-pressure lubricating liquid to the micro-textured interior, and improves the machining efficiency of micro-textured turning tools.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic machining, in particular to a variable frequency ultrasonic vibration lubrication micro-texture turning device. Background Art

[0002] During the cutting process, there is intense frictional contact between the tool surface and the workpiece, resulting in problems such as high temperature in the cutting contact area, rapid tool wear, high cutting force, and low workpiece surface quality. Especially in high-speed cutting, dry cutting, and cutting of difficult-to-cut materials, the cutting force is greater, the temperature is higher, and the cutting environment is extremely harsh, which reduces the tool life. Tool surface micro-texturing refers to the use of biomimetic principles to process micron-scale structures of a certain size and shape on the friction surface, thereby improving the cutting performance and tribological properties of the tool. Processing some micro-pits or micro-grooves array structures in the area where the tool friction occurs is more conducive to the penetration and film formation of the lubricating medium, which helps to improve the lubrication effect and reduce friction, thereby inhibiting the workpiece material from sticking to the tool, slowing tool wear, and extending tool durability.

[0003] Existing research has demonstrated that appropriate microtexture can improve the friction state at the interface of a friction pair and reduce wear. Therefore, the friction-reducing properties of microtexture offer new approaches and methods for improving tool life and cutting performance. Surface microtexture reduces tool-chip contact length, stores lubricant, and captures wear debris. Microtexture morphologies have evolved from initial pits, grooves, and convex hulls to more complex sinusoidal, elliptical, circular arrays, and fish-scale patterns. Different microtexture shapes inevitably have different effects on the tribological properties of the tool surface. Therefore, designing diverse microtexture morphologies can significantly improve tool life and tribological performance, reduce cutting forces and temperatures during the cutting process, and improve workpiece surface quality.

[0004] Due to the inherent limitations of metal cutting tools, microtexturing of turning tool surfaces is commonly achieved using electrospark machining (EDM), grinding, photolithography, and laser machining. Microtexture shapes include square protrusions, square pits, circular pits, elliptical grooves, corrugated grooves, and linear grooves, with pit- and groove-shaped surface textures being the most common. The effect of surface texture is closely related to parameters such as its shape and size. For turning tool rake face microtextures with pits and grooves parallel to the main cutting edge, these microtextures can easily lead to chip deposition due to machining limitations. The blade-like edges formed around the microtexture pits can cause secondary cutting of the chips, increasing cutting resistance. For grooved surface microtextures perpendicular to the main cutting edge, the cutting fluid aligns with the chip discharge direction, and the narrow, elongated grooves make it difficult to store lubricant. This reduces the tool-chip contact length, increases the friction coefficient on the tool rake face, and exacerbates tool wear. Therefore, finding a device that can overcome the above-mentioned micro-texture tool turning processing problems has great guiding significance for improving the micro-texture tool turning processing performance.

[0005] Tool micro-texture shape processing: Existing turning tool pit circular or square micro-texture processing methods such as Figure 3 As shown, taking laser processing as an example, the laser is perpendicular to the blade rake face (select the tool rake angle as 0 0 ), the processed micro-texture pits are vertical in shape. When cutting, the chips and debris flow through the rake face of the tool with the cutting fluid, and the chips and debris will settle in the micro-texture pits and are not easily discharged with the cutting fluid, thereby reducing the space for storing lubricating fluid in the micro-texture, weakening the function, and increasing the tool-chip friction between the chip and the micro-texture of the rake face; on the other hand: when the chip is discharged, the blade-shaped edge formed around the vertical micro-texture pit contacts the bottom of the chip, forming secondary cutting and increasing the cutting resistance; the above two aspects will aggravate tool wear. Summary of the Invention

[0006] The present invention aims to overcome the above-mentioned deficiencies of the prior art and provides a variable frequency ultrasonic vibration lubrication micro-texture turning device, which is specifically implemented by the following technical solutions:

[0007] The variable frequency ultrasonic vibration lubrication micro-texturing turning device includes an ultrasonic vibration unit, a control unit, a turning tool assembly, a height-adjustable bracket and a large carriage. The turning tool assembly and the bracket are mounted on the large carriage. The ultrasonic vibration unit is supported on the bracket and includes: a lubricating liquid supply part, an ultrasonic generator, a transducer and a nozzle. The ultrasonic generator drives the nozzle through the transducer to vibrate and pour the lubricating liquid in the lubricating liquid supply part through the nozzle into the cutting area of ​​the turning tool assembly; the control unit collects the cutting force signal of the turning tool assembly and controls the transducer to pour the lubricating liquid according to the cutting force signal.

[0008] The further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the turning tool assembly includes a carbide tool head with micro-texture, a tool body on which the carbide tool head is installed, and a tool holder on which the tool body is installed. The tool holder is installed on a large slide and is communicatively connected to a control unit. The micro-texture is located on the front cutting edge of the carbide tool head cutting area, and is a set number of orderly arranged grooves. The notch of the groove is circular, and the vertical cross-section of the groove is an incomplete ellipse. The major axis of the ellipse where the incomplete ellipse is located is at an elevation angle B with the front cutting edge of the carbide tool head, and is perpendicular to the main cutting edge of the carbide tool head.

[0009] A further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the angle B∈(30°, 50°) is formed between the major axis of the incomplete ellipse and the rake face of the tool head.

[0010] A further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the relationship between the length of the major semi-axis L2 and the minor semi-axis L1 of the ellipse where the incomplete ellipse is located is: L2=L1 / cos(B-α), where α is the tool rake angle.

[0011] A further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the ultrasonic vibration unit also includes a hose and a horn, the lubricating liquid supply part is connected to the transducer through the hose, the transducer is connected to the nozzle through the horn and increases the vibration velocity ratio of the lubricating liquid.

[0012] A further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the amplitude transformer is a hollow single or composite amplitude transformer.

[0013] The further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the control unit includes a first controller, a second controller, a central processing unit and a cutting force sensor. The cutting force sensor is fixed on the large slide and connected to the tool holder to collect the cutting force of the turning tool in real time to form a cutting force signal. The central processing unit is communicated with the cutting force sensor, the first controller and the second controller are communicated with the central processing unit respectively, the first controller is communicated with the lubricating fluid supply part to control the flow rate and flow rate of the cutting fluid; the second controller is communicated with the ultrasonic generator to control the amplitude and frequency of the ultrasonic generator to control the ultrasonic vibration energy carried by the lubricating fluid flowing out of the nozzle.

[0014] A further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the micro-texture is formed by laser processing.

[0015] A further design of the variable frequency ultrasonic vibration lubrication micro-texture turning device is that the nozzle maintains a distance of 3 to 5 mm from the rake surface of the micro-texture groove portion of the cutting area of ​​the turning tool assembly.

[0016] The advantages of the present invention are as follows:

[0017] The variable frequency ultrasonic vibration lubrication micro-texture turning device of the present invention solves the problem of aggravated debris discharge inside the micro-texture pits of the turning tool in multiple ways by adjusting the ultrasonic vibration frequency and amplitude and adjusting the lathe cutting fluid supply device during the processing process, provides continuous high-speed, high-frequency vibration lubricating fluid inside the micro-texture, and improves the processing efficiency of the micro-texture turning tool.

[0018] Furthermore, the cross-section of the micro-texture shape of the cutting area of ​​the micro-texture turning tool of the variable frequency ultrasonic vibration lubrication micro-texture turning device of the present invention is designed to be approximately a half ellipse with a certain inclination angle, and its major axis is at a certain elevation angle to the front cutting edge of the carbide tool head, and is perpendicular to the main cutting edge of the tool. This effectively avoids the accumulation of debris inside the micro-texture pit due to the upright micro-texture edge in the existing traditional micro-texture turning process, which aggravates the wear problem of the tool front cutting edge and the secondary cutting problem of chips and micro-texture edges. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of the variable frequency ultrasonic vibration lubrication micro-texture turning device.

[0020] Figure 2 Schematic diagram of the module of the variable frequency ultrasonic vibration lubrication micro-texture turning device.

[0021] Figure 3 Schematic diagram of the existing turning tool pit-shaped circular or square micro-texture processing method.

[0022] Figure 4 Schematic diagram of the micro-texture structure of the cemented carbide tool head of the present invention.

[0023] Figure 5 Schematic diagram of the method for processing micro-texture on a cemented carbide tool head of the present invention.

[0024] Figure 6 Schematic diagram of the horizontal grooves of the turning tool micro-texture of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0026] like Figure 1 、 Figure 2The variable frequency ultrasonic vibration lubrication micro-texture turning device of this embodiment is mainly composed of: an ultrasonic vibration unit, a control unit, a turning tool assembly 12, a height-adjustable bracket 10 and a large slide 9. The turning tool assembly 12 and the bracket 10 are installed on the large slide 9. The ultrasonic vibration unit is supported on the bracket 10, and is mainly composed of: a lubricating liquid supply part 1, an ultrasonic generator, a transducer 4 and a nozzle 6. The ultrasonic generator drives the nozzle through the transducer 4 to vibrate and pour the lubricating liquid in the lubricating liquid supply part through the nozzle 6 into the cutting area of ​​the turning tool assembly 12. The control unit collects the cutting force signal of the turning tool assembly and controls the transducer 4 to pour the lubricating liquid according to the cutting force signal. The ultrasonic vibration unit of this embodiment is fixed to the bracket 10 through a support seat 3.

[0027] like Figure 5 、 Figure 6 The turning tool assembly 12 primarily consists of a carbide cutter head 7 with a micro-texture 72, a cutter body 12 on which the carbide cutter head is mounted, and a tool holder 8 for mounting the cutter body. The tool holder 8 is mounted on a large carriage 9 and is in communication with a control unit. The micro-texture 72 is located on the rake face (opposite to the main cutting edge 71) of the cutting zone of the carbide cutter head 7 and consists of a predetermined number of orderly arranged grooves 72. The grooves 72 have circular notches, and the vertical cross-section of the grooves 72 is an incomplete ellipse. The major axis of the incomplete ellipse forms an elevation angle B with the carbide cutter head rake face 73 and is skewed and perpendicular to the main cutting edge of the carbide cutter head 7. The turning tool base surface 74 forms a tool rake angle α with the rake face 73.

[0028] In this embodiment, the micro texture is formed by laser processing, and the processing parameters are as follows: laser power: 12W, micro texture ellipse major axis: 250 microns, minor axis 180 microns, depth 15 microns, distance from the main cutting edge: 300 microns, transverse spacing: 250 microns, longitudinal spacing: 250 microns, speed: 2000 mm / min, frequency: 50000 Hz, processing times: 10 times. Figure 5 As shown, the lower surface of the carbide insert is supported by a wedge 14 with an angle A, the laser 13 is above the rake face 73, and the laser is vertically downward to perform micro-texturing on the rake face of the tool. The laser running trajectory is projected into a circle with a radius of R on the horizontal plane. The diameter of the circle is the length of the minor axis L1 of the micro-textured elliptical groove after processing. The relationship between the length of the major axis L2 of the micro-textured elliptical groove and the minor axis L1 is: L2=L1 / cos(A-α), α is the tool rake angle, and when the tool rake angle α is 0 0 When the wedge angle A is within the range of 30° to 50°, the optimal value is 45°.

[0029] The ultrasonic vibration unit of this embodiment further includes a hose 2 and a horn 5. The lubricating liquid supply is connected to the transducer 4 via the hose 2, and the transducer 4 is connected to the nozzle 6 via the horn 5 to increase the vibration velocity ratio of the lubricating liquid.

[0030] The horn 5 in the technical solution of the present invention is a hollow single or composite horn. This embodiment adopts a single horn.

[0031] like Figure 2 The control unit of this embodiment includes a first controller, a second controller, a central processing unit (CPU), and a cutting force sensor. The cutting force sensor is fixed to the large carriage and screwed to the tool holder 8 to collect the cutting force of the turning tool in real time, generating a cutting force signal. The CPU is in communication with the cutting force sensor, and the first and second controllers are in communication with the CPU, respectively. The first controller is in communication with the lubricating fluid supply to control the flow rate and speed of the cutting fluid. The second controller is in communication with the ultrasonic generator to control the amplitude and frequency of the ultrasonic generator to control the ultrasonic vibration energy carried by the lubricating fluid flowing out of the nozzle.

[0032] The nozzle 6 and the rake face of the micro-textured groove portion of the cutting area of ​​the turning tool assembly 12 maintain a distance of 3 to 5 mm, which is set to 4 mm in this embodiment.

[0033] When the variable frequency ultrasonic vibration lubrication micro-texture turning device of this embodiment is turning a micro-texture tool, the central processing unit is connected to the lubricating fluid supply device through the first controller and to the ultrasonic generator through the second controller respectively. The cutting force detection equipment collects the cutting force of the micro-texture turning tool clamped by the tool holder on the large slide of the lathe and transmits the data to the central processing unit; the data processed by the central processing unit is transmitted to the lubricating fluid supply device through the first controller control unit in accordance with the functional compensation distribution principle, thereby controlling the cutting fluid supply device of the variable frequency ultrasonic vibration lubrication micro-texture turning device, thereby controlling the flow rate of the cutting fluid; another signal is transmitted to the ultrasonic generator receiving control module through the second controller, thereby controlling the amplitude and frequency of the variable frequency ultrasonic vibration lubrication device's amplitude rod, thereby achieving the purpose of controlling the ultrasonic vibration energy carried by the lubricating fluid flowing out of the lubricating fluid nozzle. The microtexture on the rake face of a carbide turning tool is generated during lathe machining. The large carriage performs the cutting feed motion, driving the cutting force detection device, the microtextured turning tool on the tool holder, and the variable-frequency ultrasonic vibration lubrication device to move synchronously. As the cutting force changes, the cutting force detection component collects real-time data and transmits it to the central processing unit. The CPU then processes this data, and, in accordance with the principle of functional compensation allocation, controls the cutting fluid flow rate and the amplitude and frequency of the ultrasonic vibration device via a first controller and a second controller, respectively. This regulates the fluid dynamic pressure generated by the microtextured pits, accelerating the removal of debris from the textured pits and ensuring a continuous supply of lubricant between the tool and the chip. This improves friction in the cutting zone of the microtextured turning tool, reduces tool rake face wear, improves tool life, enhances cutting performance, and achieves efficient machining. Upon completion, the CPU records the current machining parameters for later reference, resulting in superior machining accuracy and results compared to traditional microtextured turning.

[0034] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope of the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A variable frequency ultrasonic vibration lubrication micro-texture turning device, characterized in that The invention comprises an ultrasonic vibration unit, a control unit, a turning tool assembly, a height-adjustable bracket and a large carriage. The turning tool assembly and the bracket are mounted on the large carriage. The ultrasonic vibration unit is supported on the bracket and comprises: a lubricating liquid supply part, an ultrasonic generator, a transducer and a nozzle. The ultrasonic generator drives the nozzle through the transducer to vibrate and pour the lubricating liquid in the lubricating liquid supply part through the nozzle to the cutting area of ​​the turning tool assembly; the control unit collects the cutting force signal of the turning tool assembly and controls the transducer to pour the lubricating liquid according to the cutting force signal; the turning tool assembly comprises a carbide tool head with a micro texture, a carbide tool head mounted with the carbide tool head, and a nozzle. The tool head comprises a tool body and a tool holder for mounting the tool body, wherein the tool holder is mounted on a large slide and is communicatively connected to a control unit. The micro-texture is located on the front cutting edge of the carbide tool head cutting zone, and is a set number of orderly arranged grooves. The notches of the grooves are circular, and the vertical cross-section of the grooves is an incomplete ellipse. The major axis of the ellipse where the incomplete ellipse is located is at an elevation angle B with the front cutting edge of the carbide tool head, and is skewed with the main cutting edge of the carbide tool head. The ultrasonic vibration unit further comprises a hose and an amplitude rod. The lubricating liquid supply part is connected to the transducer through the hose, and the transducer is connected to the nozzle through the amplitude rod and increases the vibration velocity ratio of the lubricating liquid.

2. The variable frequency ultrasonic vibration lubrication micro-texture turning device according to claim 1, characterized in that The angle B∈(30°, 50°) is formed between the major axis of the ellipse in which the incomplete ellipse is located and the rake face of the turning tool.

3. The variable frequency ultrasonic vibration lubrication micro-texture turning device according to claim 1, characterized in that The relationship between the length of the major semi-axis L2 and the minor semi-axis L1 of the ellipse where the incomplete ellipse is located is: L2=L1 / cos(B-ɑ), where ɑ is the tool rake angle.

4. The variable frequency ultrasonic vibration lubrication micro-texture turning device according to claim 1, characterized in that The control unit includes a first controller, a second controller, a central processing unit and a cutting force sensor. The cutting force sensor is fixed on the large slide and connected to the tool holder to collect the cutting force of the turning tool in real time to form a cutting force signal. The central processing unit is communicated with the cutting force sensor. The first controller and the second controller are communicated with the central processing unit respectively. The first controller is communicated with the lubricating fluid supply part to control the flow rate and flow rate of the cutting fluid; the second controller is communicated with the ultrasonic generator to control the amplitude and frequency of the ultrasonic generator to control the ultrasonic vibration energy carried by the lubricating fluid flowing out of the nozzle.

5. The variable frequency ultrasonic vibration lubrication micro-texture turning device according to claim 1, characterized in that The micro texture is formed by laser processing.

6. The variable frequency ultrasonic vibration lubrication micro-texture turning device according to claim 1, characterized in that The nozzle maintains a distance of 3-5 mm from the rake surface of the micro-textured groove portion in the cutting area of ​​the turning tool assembly.

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