Pulse current assisted cutting system and method

Abstract

The present invention discloses a pulse current assisted cutting system and a processing method, the system includes an electric pulse assisted processing device and a laser surface roughness online detection device; the electric pulse assisted processing device includes a high-frequency pulse generator and a fixture, the high-frequency pulse generator is connected to the fixture through a wiring cable, and the fixture is clamped on the fixture of a five-axis machining center; the laser surface roughness online detection device includes a laser roughness detection head, a holder and an oscilloscope, the holder is fixed on the tool magazine of the five-axis machining center, the laser roughness detection head is clamped on the top of the holder, the focus point points to the machined surface of the workpiece, and the laser roughness detection head is connected to the oscilloscope through a signal line. The present invention solves the problems of work hardening and severe tool wear faced by titanium alloys during processing, and can effectively ensure the stability of product quality and improve the production efficiency of titanium alloy components.

Description

Technical Field

[0001] The present invention relates to a parts processing technology involving titanium alloy and other difficult-to-process metal materials, in particular to a pulse current assisted cutting processing system and processing method, belonging to the technical field of metal processing. Background Art

[0002] The superior physical and chemical properties of titanium alloy make it a highly attractive structural engineering material, and it has been widely used in important manufacturing fields such as aerospace, military industry, biomedicine, sports equipment and automobiles. For most of these parts, cutting processing is one of the necessary processes. However, due to the high strength, low heat transfer coefficient, strong chemical affinity and low elastic modulus of titanium alloy materials, if the cutting process is not appropriate, the micro cracks generated will initiate on the surface and near the surface of the material, which will destroy the mechanical properties and fatigue resistance of the material surface; and for parts with complex structures, traditional machine tools cannot achieve fast and effective processing, and the cutting accuracy is difficult to guarantee; the roughness detection of finished components still generally adopts offline sampling detection, which cannot monitor the processed components in real time, and the detection efficiency is low and time-consuming. Summary of the invention

[0003] The purpose of the present invention is to address the shortcomings of processing technology for parts of difficult-to-process metal materials such as titanium alloys, and to provide a pulse current assisted cutting processing system. The system solves the problems of work hardening and severe tool wear currently faced by titanium alloys during processing. At the same time, by adding a laser roughness online detection device to perform real-time roughness detection on the processed surface of the parts, replacing the original offline detection method, it can effectively ensure the stability of product quality and improve the production efficiency of titanium alloy components.

[0004] Another object of the present invention is to provide a pulse current assisted cutting method, which is implemented based on the above-mentioned pulse current assisted cutting system.

[0005] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] A pulse current assisted cutting system, comprising an electric pulse assisted processing device and a laser surface roughness online detection device;

[0007] The electric pulse assisted machining device comprises a high-frequency pulse generator and a fixture, wherein the high-frequency pulse generator is connected to the fixture via a wiring cable, and the fixture is clamped on a fixture of a five-axis machining center;

[0008] The laser surface roughness online detection device includes a laser roughness detection head, a holder and an oscilloscope. The holder is fixed on the tool magazine of a five-axis machining center. The laser roughness detection head is clamped on the top of the holder, with the focus pointing to the machined surface of the workpiece. The laser roughness detection head is connected to the oscilloscope through a signal line.

[0009] Furthermore, the fixture base is clamped on a fixture of a five-axis machining center, and the fixture is insulated from the fixture of the five-axis machining center, and the middle of the fixture is separated into two parts by an insulating material.

[0010] Furthermore, the bottom of the fixture base has a round rod, and the round rod is made of insulating material. The fixture base is clamped on the five-axis machining center fixture through the round rod.

[0011] Furthermore, the clamp is a three-jaw chuck structure, including a chuck body, a first clamp body, a second clamp body, a third clamp body, a first positive terminal and a first negative terminal. The first clamp body and the third clamp body are respectively arranged at both ends of the conductive area on the chuck body, and are respectively connected to the first positive terminal and the first negative terminal. The first positive terminal and the first negative terminal are respectively connected to the high-frequency pulse generator through connection cables. The second clamp body is arranged in an insulating area on the chuck body, and the insulating area divides the chuck body into two parts.

[0012] Furthermore, the retaining frame is a four-bar mechanism, and each connection is driven by four steering gears.

[0013] Furthermore, the retaining frame includes a fixed head, a first connecting rod and a second connecting rod. The fixed head is loaded in a threaded hole of a tool magazine of a five-axis machining center, and the fixed head, the first connecting rod and the second connecting rod are hinged in sequence.

[0014] Furthermore, the DuPont wire required for driving the steering gear is constrained by the first limiting hole.

[0015] Furthermore, the high-frequency pulse generator is provided with a control panel, which is provided with a switch, an adjustment button, a display screen and terminals, the terminals including a second positive terminal, a second negative terminal and a grounding terminal, and the second positive terminal and the second negative terminal are respectively connected to the clamp through a wiring cable.

[0016] Furthermore, a universal wheel is provided at the bottom of the high-frequency pulse generator.

[0017] Furthermore, the signal line is constrained by a second limiting hole.

[0018] Another object of the present invention can be achieved by adopting the following technical solutions:

[0019] A pulse current assisted cutting processing method is implemented based on the above-mentioned pulse current assisted cutting processing system. The method includes: applying a high-frequency pulse generator to both ends of a fixture so that a high-frequency pulse current is passed through the processed parts, and utilizing the thermal and non-thermal effects of the high-frequency pulse current to produce an electroplastic effect on the metal material. At the same time, a laser roughness online detection device is used to perform real-time detection of the processed surface of the processed parts.

[0020] The present invention has the following beneficial effects compared with the prior art:

[0021] 1. When processing difficult-to-process metal materials such as titanium alloys, the present invention applies high-frequency pulse current to the processed parts, and uses its thermal and non-thermal effects to produce electroplastic effects on the metal materials, which can improve the plasticity of the workpiece, reduce the strength and work hardening rate, promote atomic diffusion and dislocation movement of the workpiece, and help improve the cutting performance.

[0022] 2. The high-frequency pulse current applied by the present invention is applied to both ends of the fixture, and cannot form a loop through the fixture when there are no parts clamped, ensuring that the high-frequency pulse current passes through the processed parts completely, effectively increasing the root mean square current density inside the workpiece, and the fixture is insulated from the original fixture of the five-axis machining center, which can prevent the five-axis machining center from being electrified and causing safety accidents.

[0023] 3. During the processing, the present invention uses a laser roughness online detection device to monitor the processed surface of the workpiece in real time, replacing the original offline detection method, which can effectively ensure the stability of product quality and improve the production efficiency of titanium alloy components. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0025] Figure 1 It is a structural diagram of an electric pulse assisted machining device according to an embodiment of the present invention.

[0026] Figure 2 It is a structural diagram of a laser surface roughness online detection device according to an embodiment of the present invention.

[0027] Figure 3 It is a side view of the fixture axis in the electric pulse assisted machining device according to an embodiment of the present invention.

[0028] Figure 4It is a right view of the fixture in the electric pulse assisted machining device according to an embodiment of the present invention.

[0029] Figure 5 for Figure 4 AA section view.

[0030] Figure 6 It is a structural diagram of a high-frequency pulse generator in an electric pulse assisted machining device according to an embodiment of the present invention.

[0031] Among them, 1-high frequency pulse generator, 101-switch, 102-adjustment button, 103-display screen, 104-second positive terminal, 105-second negative terminal, 106-ground terminal, 107-universal wheel, 2-clamp, 201-round rod, 202-chuck body, 2021-conductive area, 2022-insulating area, 203-first clamp body, 204-second clamp body, 205-third clamp body, 206-first positive terminal, 207-first negative terminal, 3-cable, 4-laser roughness detection head, 5-holder, 501-fixed head, 502-first connecting rod, 503-second connecting rod, 6-oscilloscope, 7-first-stage servo, 8-second-stage servo, 9-third-stage servo, 10-fourth-stage servo, 11-first limiting hole, 12-second limiting hole. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] Example:

[0034] like Figure 1 and Figure 2 As shown, this embodiment provides a pulse current assisted cutting processing system, including an electric pulse assisted processing device and a laser surface roughness online detection device, the electric pulse assisted processing device includes a high-frequency pulse generator 1 and a fixture 2, the high-frequency pulse generator 1 is connected to the fixture 2 through a wiring cable 3, and the fixture 2 is clamped on the fixture of the five-axis machining center; the laser surface roughness online detection device includes a laser roughness detection head 4, a holder 5 and an oscilloscope 6, the holder 5 is fixed on the tool magazine of the five-axis machining center, the laser roughness detection head 4 is clamped on the top of the holder 5, the focus point points to the processed surface of the workpiece, and the laser roughness detection head 4 is connected to the oscilloscope 6 through a signal line.

[0035] like Figure 1 to Figure 5As shown, the base of the fixture 2 is clamped on the fixture of the five-axis machining center, and the fixture 2 is insulated from the fixture of the five-axis machining center. The middle of the fixture 2 is separated into two parts by insulating material. Only when there are conductive parts clamped can the pulse current pass through to form a complete circuit between the high-frequency pulse generator 1; specifically, the bottom of the base of the fixture 2 has a round rod 201, and the round rod 201 is made of insulating material. The base of the fixture 2 is clamped on the fixture of the five-axis machining center through the round rod 201 to ensure that the fixture 2 is insulated from the five-axis machining center during operation.

[0036] Furthermore, the clamp 2 is a three-jaw chuck structure, which includes a chuck body 202, a first clamp body 203, a second clamp body 204, a third clamp body 205, a first positive terminal 206 and a first negative terminal 207. The first clamp body 203 and the third clamp body 205 are respectively arranged at two ends of a conductive area 2021 on the chuck body 202, and are respectively connected to the first positive terminal 206 and the first negative terminal 207. The first positive terminal 206 and the first negative terminal 207 are respectively connected to the high-frequency pulse generator 1 through a connection cable 3. The second clamp body 204 is arranged in an insulating area 2022 on the chuck body 202, so it is not charged, and the insulating area 2022 divides the chuck body 202 of the fixture 2 into two parts. Only when the first clamp body 203 and the first clamp body 204 are in contact with the conductive parts at the same time, can a passage be formed inside the fixture 2. It should be noted that during processing, the processed parts must be clamped stably on the fixture 2 before power is turned on. In addition, it is forbidden to short-circuit the first clamp body 203 and the third clamp body 205 when power is turned on, so as to avoid discharge and cause danger.

[0037] like Figure 1 to Figure 6 As shown, the high-frequency pulse generator 1 is connected to a 380V power supply, and a switch 101, an adjustment button 102, a display screen 103 and a terminal are provided on the high-frequency pulse generator 1. The switch 101 can control the start and stop of the high-frequency pulse generator 1, and the adjustment button 102 is used to adjust the current parameters. Specifically, there are three adjustment knobs 34 that can adjust the voltage, current, amplitude and frequency. The display screen 102 can display the current voltage, current, amplitude and frequency values; the terminal includes a second positive terminal 104, a second negative terminal 105 and a grounding terminal 106. The second positive terminal 104 and the second negative terminal 105 are respectively connected to the first positive terminal 206 and the first negative terminal 207 of the clamp 2 through a wiring cable, and a buckle is provided at the connection to prevent falling off. The grounding terminal 106 is used for grounding.

[0038] Preferably, a universal wheel 107 is provided at the bottom of the high-frequency pulse generator 1 to facilitate the user to move it to a suitable position, and a buckle is provided to lock the universal wheel 107 in place.

[0039] Furthermore, the retaining frame 5 is a four-bar mechanism, and each connection is driven by four steering gears. The four steering gears can be divided into a first-stage steering gear 7, a second-stage steering gear 8, a third-stage steering gear 9 and a fourth-stage steering gear 10.

[0040] Furthermore, the retaining frame 5 includes a fixed head 501, a first connecting rod 502 and a second connecting rod 503, the fixed head 501 is loaded in the threaded hole of the tool magazine of the five-axis machining center, and the fixed head 501, the first connecting rod 502 and the second connecting rod 503 are hinged in sequence, and the connecting slots at both ends of the first connecting rod 502 and the second connecting rod 503 are vertically configured, so that the mechanism has more posture selection states; the first-level steering gear 7 can drive the lower mechanism to rotate around the vertical direction; the second-level steering gear 8 drives the first connecting rod 502 to rotate around the connection direction, the third-level steering gear 9 drives the second connecting rod 503 to rotate around the connection direction, and the fourth-level steering gear 10 drives the laser roughness detection head 4 to rotate around the connection direction. The DuPont line required for the steering gear drive is constrained by the first limit hole 11, and the steering gear reference processing parts are configured. The processing steps of the parts are set, and the position and posture of the holder 5 are changed as the processing process proceeds by controlling the rotation of the servo, ensuring that the laser focus point of the top measuring head always follows the latest processed surface to complete real-time detection; the laser roughness detection head can emit a laser signal and collect the reflected laser signal, which is processed to reflect the surface contour of the processed parts. The signal line connected to the laser roughness detection head 4 is constrained by the second limit hole 12 and finally connected to the oscilloscope 6. The oscilloscope 6 can display the measured roughness curve and value in real time. The first limit hole 11 and the second limit hole 12 can prevent the DuPont line required for the servo drive, the signal line connected to the laser roughness detection head 4 and the holder 5 from being entangled or interfering during operation.

[0041] The working principle of the pulse current assisted cutting processing system of this embodiment is: a high-frequency pulse generator is applied to both ends of the fixture, so that a high-frequency pulse current is passed through the processed parts, and the thermal effect and non-thermal effect of the high-frequency pulse current are used to produce an electroplastic effect on the metal material. At the same time, the laser roughness online detection device is used to perform real-time detection of the processed surface of the processed parts.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and agreed, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The terms "upper", "lower", "left", "right" and similar expressions used are only for illustrative purposes and do not represent the only implementation method.

[0043] In summary, when processing difficult-to-process metal materials such as titanium alloys, the present invention applies high-frequency pulse current to the processed parts, and uses its thermal effect and non-thermal effect to produce electroplastic effect on the metal material, which can improve the plasticity of the workpiece, reduce the strength and work hardening rate, promote atomic diffusion and dislocation movement of the workpiece, and is beneficial to improving the cutting performance; the applied high-frequency pulse current is applied to both ends of the fixture, and cannot form a loop through the fixture when there is no component clamped, ensuring that the high-frequency pulse current passes through the processed parts completely, effectively improving the root mean square current density inside the workpiece, and the fixture is insulated from the original fixture of the five-axis machining center, which can prevent the five-axis machining center from being electrified and causing safety accidents; during the machining process, the processed surface of the workpiece is monitored in real time by an online laser roughness detection device, replacing the original offline detection method, which can effectively ensure the stability of product quality and improve the production efficiency of titanium alloy components.

[0044] The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and inventive concept of the present invention within the scope disclosed by the present invention, which shall fall within the protection scope of the present invention.

Claims

1. A pulse current assisted cutting system, characterized in that: It includes an electric pulse assisted processing device and a laser surface roughness online detection device; The electric pulse assisted machining device includes a high-frequency pulse generator and a fixture, wherein the high-frequency pulse generator is connected to the fixture through a wiring cable, the fixture is insulated from the fixture of the five-axis machining center, and the middle of the fixture is separated into two parts by an insulating material. Only when a conductive part is clamped, the pulse current passes through the high-frequency pulse generator to form a complete loop; the bottom of the fixture base has a round rod, the round rod is made of insulating material, and the fixture base is clamped on the fixture of the five-axis machining center through the round rod; the fixture is a three-jaw chuck structure, including a chuck body, a first clamp body, a second clamp body, a third clamp body, a first positive terminal and a first negative terminal, the first clamp body and the third clamp body are respectively arranged at the two ends of the conductive area on the chuck body, and are respectively connected to the first positive terminal and the first negative terminal, the first positive terminal and the first negative terminal are respectively connected to the high-frequency pulse generator through a wiring cable, the second clamp body is arranged in the insulating area on the chuck body, and the insulating area divides the chuck body into two parts; The laser surface roughness online detection device includes a laser roughness detection head, a holder and an oscilloscope. The holder is fixed on the tool magazine of a five-axis machining center. The laser roughness detection head is clamped on the top of the holder, and the focus point points to the machined surface of the workpiece. The laser roughness detection head is connected to the oscilloscope through a signal line. The holder is a four-bar mechanism, and each connection is driven by four servos. The holder includes a fixed head, a first connecting rod and a second connecting rod. The fixed head is loaded in the threaded hole of the tool magazine of the five-axis machining center, and the fixed head, the first connecting rod and the second connecting rod are hinged in sequence. The holder changes its position and posture as the machining process proceeds by controlling the rotation of the servo, ensuring that the laser focus point of the top measuring head always follows the latest machined surface to complete real-time detection. The laser roughness detection head emits a laser signal and collects the reflected laser signal, which reflects the surface contour of the machined parts after processing, and the oscilloscope displays the measured roughness curve and value in real time.

2. The pulse current assisted cutting system according to claim 1, characterized in that: The DuPont wire required for the steering gear drive is constrained by the first limiting hole.

3. The pulse current assisted cutting system according to any one of claims 1 to 2, characterized in that: The high-frequency pulse generator is provided with a control panel, which is provided with a switch, an adjustment button, a display screen and a terminal. The terminal includes a second positive terminal, a second negative terminal and a grounding terminal. The second positive terminal and the second negative terminal are respectively connected to the clamp through a wiring cable.

4. The pulse current assisted cutting system according to any one of claims 1 to 2, characterized in that: The bottom of the high-frequency pulse generator is provided with a universal wheel.

5. The pulse current assisted cutting system according to any one of claims 1 to 2, characterized in that: The signal line is constrained by the second limiting hole.

6. A pulse current assisted cutting method, implemented based on the pulse current assisted cutting system according to any one of claims 1 to 5, characterized in that: The method comprises: applying a high-frequency pulse generator to both ends of a fixture so that a high-frequency pulse current is passed through the processed parts, utilizing the thermal effect and non-thermal effect of the high-frequency pulse current to produce an electroplastic effect on the metal material, and simultaneously performing real-time detection of the processed surface of the processed parts through a laser roughness online detection device.

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