Ceramic matrix composite micro-deep hole multi-frequency pulsating chip removal enhanced machining method and system

Abstract

The present application relates to a kind of ceramic matrix composite micro deep hole complex frequency pulse chip removal enhanced processing method and system.The method makes tool simultaneously occur axial and radial ultrasonic vibration and axial low frequency pulsation when processing, wherein the amplitude of low frequency pulsation is greater than the amplitude of axial ultrasonic vibration.Tool has axial through hole for cooling liquid, when tool occurs low frequency pulsation upward movement, form transient low pressure in cutting zone, provide cooling liquid to cutting zone through tool and cooling liquid outside tool flows back to cutting zone.When tool occurs low frequency pulsation downward movement, stop providing cooling liquid to cutting zone, cutting zone forms transient high pressure, cooling liquid moves outward through the gap channel between tool and workpiece, while cooperating with ultrasonic radial vibration, periodically increase the width of gap channel, promote chip removal.The method greatly improves processing quality and tool life, while realizing efficient chip removal, achieves the purpose of high efficiency and high quality micro deep hole machining of ceramic material.

Description

Technical Field

[0001] This invention relates to the field of materials processing technology, and in particular to a method and system for enhancing the micro-deep hole chip removal process of ceramic matrix composite materials using complex frequency pulsation. Background Technology

[0002] The widespread application of ceramic matrix composites (CMCs) is a significant development trend in the aerospace manufacturing field. Due to their excellent properties such as lightweight, high strength, high modulus, wear resistance, and resistance to high and low temperatures, the demand for CMCs in the aerospace sector is increasing, and their proportion in the total materials used in aerospace is gradually rising. With the extensive application of new materials, technologies, and structures in various equipment, the structural shapes of parts are becoming more complex. The machining difficulty of difficult-to-machine structures (such as micro-holes, oblique holes, and deep holes) is increasing, and the quality of holes (positional accuracy, diameter accuracy, etc.) and machining efficiency are becoming increasingly important. The application of numerous advanced materials is pushing the manufacturability of parts to extremes, providing new opportunities for the development of manufacturing technologies.

[0003] Currently, traditional machining processes face challenges in improving the quality and efficiency of micro-deep hole machining in ceramic matrix composites. The characteristics of deep hole machining technology and the high precision requirements make deep hole drilling of large aspect ratio ceramic matrix composites particularly difficult, and the following main problems need to be addressed:

[0004] (1) The cutting process of hard and brittle ceramic matrix composites is characterized by heat accumulation and large cutting force. The cutting process is prone to mechanical damage such as material fracture and tearing, making it difficult to ensure accuracy.

[0005] (2) Deep hole machining is a semi-enclosed machining process. The tool is severely squeezed against the hole wall, the temperature in the cutting zone is high, and the cutting force and torque are too large, which will cause severe tool wear and tool breakage failure.

[0006] (3) Chips from deep hole drilling are very likely to clog the chip removal groove, causing secondary cutting on the surface of the machined hole, resulting in surface defects, affecting the machining accuracy of the hole, and even causing tool breakage, which greatly affects the machining efficiency.

[0007] (4) The rigidity of micro deep hole tools is low. Tool chatter during deep hole drilling reduces the stability of the tool cutting process and causes the deep hole axis to deviate.

[0008] Therefore, it is urgent to solve the problems existing in the machining of micro-holes and deep holes, especially micro-deep holes, of ceramic matrix composites using traditional processing methods. Summary of the Invention

[0009] The purpose of this invention is to provide a method and system for enhancing the micro-deep hole chip removal process of ceramic matrix composite materials by multiple frequency pulsation, thereby solving at least one technical problem existing in the background art.

[0010] To achieve the above objectives, in a first aspect, the present invention provides a method for enhancing chip removal in micro-deep holes of ceramic matrix composite materials using complex frequency pulsation. During machining, the tool is simultaneously subjected to axial and radial ultrasonic vibrations as well as axial low-frequency pulsations, wherein the amplitude of the low-frequency pulsations is greater than the amplitude of the axial ultrasonic vibrations.

[0011] The tool has an axially arranged through hole for coolant to pass through. When the tool moves upward with low-frequency pulsation, a momentary low pressure is formed in the cutting zone, which provides coolant to the cutting zone through the tool and the coolant located on the outside of the tool flows back to the cutting zone.

[0012] When the tool moves downwards with low-frequency pulsation, the supply of coolant to the cutting zone stops, and instantaneous high pressure is formed in the cutting zone. The coolant moves out of the channel through the gap between the tool and the workpiece.

[0013] In a second aspect, the present invention also provides a ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system for realizing the ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining method of the first aspect, comprising a central rotating shaft, a low-frequency pulsating part, an elliptical ultrasonic transducer, an amplitude transformer tool connector, a one-way valve, a tool, an ultrasonic drive power supply and a controller. The central rotating shaft, the low-frequency pulsating part, the elliptical ultrasonic transducer, the amplitude transformer tool connector, the one-way valve and the tool are connected in sequence. The central rotating shaft is used to connect to the spindle of the machining center. The low-frequency pulsating part enables the tool to generate low-frequency pulsation in the axial direction. The elliptical ultrasonic transducer enables the tool to generate axial and radial ultrasonic vibration. The ultrasonic drive power supply is connected to the elliptical ultrasonic transducer. The controller is connected to the ultrasonic drive power supply and the control part of the machining center.

[0014] The central shaft, low-frequency pulsating section, elliptical ultrasonic transducer, amplitude transformer tool connector, and tool all have axial through holes. After the central shaft, low-frequency pulsating section, elliptical ultrasonic transducer, amplitude transformer tool connector, one-way valve, and tool are connected, their respective axial through holes are connected to the one-way valve to form a coolant channel. When the tool moves upward with low-frequency pulsation, the one-way valve is open, and the coolant flows into the cutting zone. When the tool moves downward with low-frequency pulsation, the one-way valve is closed.

[0015] Optionally, the check valve includes a valve body, a suspended ball, a limiting ring, and a support block. The limiting ring is connected to the inner wall of the valve body, and the support block is connected to the inner wall of the valve body. At least one side of the support block is spaced from the inner wall of the valve body to form a liquid passage. The support block and the limiting ring are spaced apart, and the support block is located below the limiting ring. The suspended ball is located between the limiting ring and the support block and can move up and down between the limiting ring and the support block. When the suspended ball abuts against the annular hole of the limiting ring, the check valve is closed. When the suspended ball disengages from the annular hole of the limiting ring, the check valve is open.

[0016] Optionally, one end of the support block is connected to the inner wall of the valve body, and the other end is spaced from the inner wall of the valve body, forming two liquid passages.

[0017] Optionally, the low-frequency pulsating section includes a flat ring, rollers, a track ring, a roller cage, a bearing, an elastic connector, a spring, and a transducer connector. The roller cage is fixedly connected to a machining center, and the outer periphery of the flat ring is fixedly connected to the roller cage. The central rotating shaft is rotatably connected to the inner side of the flat ring via a bearing. The elastic connector is located below the flat ring, with one end coaxially connected to the central rotating shaft and the other end coaxially connected to the track ring. The rollers are located between the flat ring and the track ring, and multiple rollers are spatially symmetrically arranged along the centerline of the central rotating shaft. The track ring has a sinusoidal curved surface track on the side that contacts the rollers. Multiple springs are located between the track ring and the base plate of the roller cage to provide elastic support for the track ring. A plane bearing is provided on the lower side or inside of the track ring. One end of the spring is fixedly connected to the base plate of the roller cage, and the other end is fixedly connected to the loose ring of the plane bearing. One end of the transducer connector passes through the tight ring of the plane bearing and is coaxially connected to the track ring. The other end passes through the base plate of the roller cage and is connected to the elliptical ultrasonic transducer. The elastic connector, track ring, tight ring of the plane bearing, and transducer connector rotate with the central rotating shaft, and the track ring generates a reciprocating motion along the axial direction of the central rotating shaft during rotation.

[0018] Optionally, the roller cage is fixedly connected to the machining center via a stop.

[0019] Optionally, the transducer connector has a columnar structure, and the end connected to the elliptical ultrasonic transducer has a flange structure. A sealing ring is fitted on the outside of the transducer connector, and the sealing ring is located between the flange structure and the bottom plate of the roller cage.

[0020] Optionally, the two ends of the one-way valve are respectively connected to the amplitude rod cutter connector and the cutter thread; or

[0021] The amplitude rod cutter connector is connected to the cutter via a spring clip. A one-way valve is located inside the spring clip, and its two ends are connected to the amplitude rod cutter connector and the cutter, respectively.

[0022] Optionally, the cutting tool is a diamond bushing drill or a diamond grinding wheel.

[0023] Optionally, the ultrasonic drive power supply and the elliptical ultrasonic transducer are connected via an aviation plug or a direct circuit connection.

[0024] The above-described technical solution of the present invention has the following advantages:

[0025] The present invention provides a method for enhancing chip removal in micro-deep hole machining of ceramic matrix composites using multi-frequency pulsation. During machining, the tool simultaneously undergoes axial and radial ultrasonic vibrations, as well as axial low-frequency pulsations, wherein the amplitude of the low-frequency pulsations is greater than the amplitude of the axial ultrasonic vibrations. Based on this, the tool has an axially arranged through-hole for coolant passage. When the tool moves upwards during low-frequency pulsation, a momentary low pressure is created in the cutting zone, supplying coolant to the cutting zone through the tool and allowing coolant located outside the tool to flow back to the cutting zone. When the tool moves downwards during low-frequency pulsation, coolant supply to the cutting zone stops, creating a momentary high pressure in the cutting zone, and coolant flows outwards through the gap channel between the tool and the workpiece. This method can induce periodic changes in the gap channel between the outer surface of the tool and the inner surface of the workpiece through radial ultrasonic vibration of the tool. In addition, radial ultrasonic vibration is combined with the low-frequency pulse vibration of the tool and the control of the coolant by the one-way valve. Under the low-frequency pulsation of the axis, the chips are discharged from the hole in a pulsating manner, so that the tool vibration interface is cooled and lubricated in a timely and sufficient manner. Ultrasonic frequency separation is used to reduce the force and heat in the machining process, which greatly improves the machining quality and tool life. At the same time, it achieves efficient chip removal and achieves the goal of efficient and high-quality micro-deep hole machining of ceramic materials.

[0026] The ceramic matrix composite micro-deep hole machining system provided by this invention features a central rotating shaft, a low-frequency pulsating section, an elliptical ultrasonic transducer, an amplitude transformer tool connector, and a cutting tool, all with axial through holes. These axial through holes are connected to one-way valves, forming coolant channels. The one-way valve, located between the amplitude transformer tool connector and the cutting tool, serves as the on / off control structure for the coolant channel. The coolant channel is connected to a coolant tank via a high-pressure cooling pump. When the cutting tool moves upwards with low-frequency pulsation, the one-way valve is open, allowing coolant to flow into the cutting zone from both the outer and inner circulation channels, achieving cooling and lubrication. When the cutting tool moves downwards with low-frequency pulsation, the one-way valve is closed, creating a momentary pulsed high pressure in the cutting zone. The coolant carries chips through the gap between the cutting tool and the workpiece, moving them out of the hole. Furthermore, because the cutting tool also undergoes radial ultrasonic vibration during machining, the chip removal space is periodically increased, further achieving efficient chip removal. The overall structure is simple, with high machining accuracy, achieving the goal of efficient and high-quality micro-deep hole machining of ceramic materials. Attached Figure Description

[0027] The accompanying drawings are provided for illustrative purposes only, and the proportions and quantities of the components in the drawings may not be consistent with the actual product.

[0028] Figure 1 This is a schematic diagram of the structure of a ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement processing system according to an embodiment of the present invention;

[0029] Figure 2 This is an enlarged schematic diagram of the processing area in a ceramic matrix composite material micro-deep hole processing embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram illustrating the principle of low-frequency pulsation suppressing tool chatter in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of elliptical ultrasonic vibration increasing the chip removal space;

[0032] Figure 5 This is a schematic diagram of a one-way valve passage state in an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of a one-way valve in a circuit-broken state according to an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of a flat ring, roller, track ring and roller cage in an embodiment of the present invention.

[0035] In the picture:

[0036] 100: Machining center;

[0037] 101: Spindle;

[0038] 102: Machining Center Control Department;

[0039] 103: Stop bracket;

[0040] 200: Workpiece;

[0041] 201: Chips;

[0042] 202: Core material;

[0043] 300: Flow direction arrow;

[0044] 1: Central pivot;

[0045] 2: Low-frequency pulsating part;

[0046] 21: Flat ring;

[0047] 22: Roller;

[0048] 23: Loop;

[0049] 24: Roller cage;

[0050] 25: Bearings;

[0051] 26: Flexible connectors;

[0052] 27: Spring;

[0053] 28: Transducer connector;

[0054] 29: Sealing ring;

[0055] 3: Elliptical ultrasonic transducer;

[0056] 31: Aviation connector;

[0057] 4: Amplitude Variable Bar Cutter Connector;

[0058] 5: Check valve;

[0059] 51: Valve body;

[0060] 52: Limiting ring;

[0061] 53: Support block;

[0062] 54: Suspended ball;

[0063] 6: Knives;

[0064] 61: Abrasive grains;

[0065] 7: Controller;

[0066] 8: Ultrasonic drive power supply;

[0067] 9: Coolant tank;

[0068] 91: Coolant;

[0069] 10: High-pressure cooling pump. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0072] In existing technologies, because the cutting zone is closed during deep hole machining, conventional methods require the use of high-pressure cutting fluid to break the chips, which are then discharged with the special high-pressure cutting fluid. However, for machining micro-holes (diameter ≤ 1.0 mm) in hard and brittle ceramic matrix composite materials, it is difficult to use traditional high-pressure cutting fluids due to the limited chip removal space, which affects the chip removal efficiency of conventional hole drilling methods.

[0073] The ceramic matrix composite micro-deep hole micro-processing method with enhanced chip removal via complex frequency pulsation provided in this invention involves simultaneously subjecting the cutting tool to axial and radial ultrasonic vibrations, as well as axial low-frequency pulsations, during machining. The amplitude of the low-frequency pulsations is greater than that of the axial ultrasonic vibrations. The cutting tool has an axially oriented through-hole for coolant passage. When the cutting tool moves upwards with low-frequency pulsation, a momentary low pressure is created in the cutting zone, supplying coolant to the cutting zone through the tool and allowing coolant located outside the tool to flow back to the cutting zone. When the cutting tool moves downwards with low-frequency pulsation, coolant supply to the cutting zone ceases, creating a momentary high pressure in the cutting zone. The coolant then flows outwards through the gap channel between the cutting tool and the workpiece. This method enables the radial ultrasonic vibration of the cutting tool to induce periodic changes in the gap channel between the outer surface of the cutting tool and the inner surface of the workpiece. In addition, radial ultrasonic vibration is combined with the low-frequency pulse vibration of the tool and the control of the coolant by the one-way valve. Under the low-frequency pulsation of the axis, the chips are discharged from the hole in a pulsating manner, so that the tool vibration interface is cooled and lubricated in a timely and sufficient manner. Ultrasonic frequency separation is used to reduce the force and heat in the machining process, which greatly improves the machining quality and tool life. At the same time, it achieves efficient chip removal and achieves the goal of efficient and high-quality micro-deep hole machining of ceramic materials.

[0074] The following example, using a ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement processing system capable of realizing the above-mentioned ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement processing method, further illustrates the ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement processing method of the present invention and the technical effects achieved.

[0075] See Figure 1As shown, the ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhanced machining system includes a central rotating shaft 1, a low-frequency pulsating section 2, an elliptical ultrasonic transducer 3, an amplitude transformer tool connector 4, a one-way valve 5, a tool 6, an ultrasonic drive power supply 8, and a controller 7. The central rotating shaft 1, low-frequency pulsating section 2, elliptical ultrasonic transducer 3, amplitude transformer tool connector 4, one-way valve 5, and tool 6 are connected sequentially. The central rotating shaft 1 is used to connect to the spindle 101 of the machining center 100. The low-frequency pulsating section 2 enables the tool 6 to generate low-frequency pulsations in the axial direction. The elliptical ultrasonic transducer 3 enables the tool 6 to generate axial and radial ultrasonic vibrations. The ultrasonic drive power supply 8 is connected to the elliptical ultrasonic transducer 3 to achieve amplitude adjustment of the ultrasonic vibration. The controller 7 is signal-connected to the ultrasonic drive power supply 8 and the machining center control unit 102 for receiving or transmitting signals. In this embodiment, the controller 7 can be a computer.

[0076] The central rotating shaft 1, low-frequency pulsating section 2, elliptical ultrasonic transducer 3, amplitude transformer tool connector 4, and tool 6 all have axial through holes, each connected to a one-way valve 5 to form a coolant channel. The one-way valve 5, located between the amplitude transformer tool connector 4 and the tool 6, serves as the on / off control structure for the coolant channel. The coolant channel is connected to the coolant tank 9 via a high-pressure cooling pump 10. (See also...) Figure 5 As shown, when the tool 6 moves upward with low-frequency pulsation, the one-way valve 5 is open, and the coolant 91 flows into the cutting zone from the outer and inner circulation channels along the direction indicated by the arrow 300, achieving cooling and lubrication. (See also...) Figure 6 As shown, when the tool 6 experiences low-frequency pulsation downwards, the one-way valve 5 is disconnected, creating a momentary pulsed high pressure in the cutting zone. The coolant 91 carries the chips 201 through the gap between the tool 6 and the workpiece 200, moving them out of the hole to achieve chip removal. Furthermore, since the tool 6 also experiences radial ultrasonic vibration during machining, the chip removal space is periodically increased, further achieving efficient chip removal.

[0077] See Figure 3 and Figure 4 As shown, assuming the gap channel width is D in the vibration-free state and the amplitude of radial ultrasonic vibration is A2, when the radial ultrasonic vibration is to the right, the instantaneous maximum value of the left gap channel is D+A2, and when the radial ultrasonic vibration is to the left, the instantaneous maximum value of the right gap channel is D+A2, thus increasing the chip removal space.

[0078] Furthermore, because the tool 6 experiences low-frequency axial pulsation during the machining process of this invention, chattering of the tool 6 can be suppressed. See also Figure 3 As shown, in the machining of micro-deep holes, the tool 6 is subjected to an axial force F. thFurthermore, the slender cutting tool 6 is highly susceptible to chatter, leading to scratches on the inner surface and a decline in machining quality. In this embodiment, the cutting tool 6 experiences low-frequency pulsations with a relatively large amplitude (generally greater than 10 μm) during machining. Therefore, during machining, the cutting tool 6 and the machining channel of the workpiece 200 undergo a cyclical reciprocating motion similar to drilling, separating, and re-drilling. During the separation phase, the cutting tool 6 separates from the material being machined, ceases cutting motion, receives no external excitation input, and the cutting tool 6 returns to stability. Simultaneously, ensuring that the cutting tool 6 is in the same or relatively close state each time it enters the machining channel helps suppress tool 6 deflection. On the other hand, ultrasonic vibration can suppress chatter for two main reasons: first, ultrasonic vibration is a forced vibration, reducing self-excited chatter from the cutting tool 6; second, the drilling, separating, and re-drilling actions are superimposed with ultrasonic vibration, and the separation under ultrasonic action instantly removes the external excitation source, suppressing chatter. It should be noted that… Figure 3 The diagram shows the length of the tool 6. The tool 6 is shown in a simplified diagram. The solid line between the two diagonal dashed lines and the rectangle with a certain width at the bottom represent the tool 6. The upper part is simplified to a line, and the lower part shows the diameter of the tool 6. The diagonal dashed lines and the rectangular dashed lines indicate the position where the tool undergoes radial ultrasonic vibration.

[0079] See Figure 5 and Figure 6 As shown, in one example, the one-way valve 5 includes a valve body 51, a suspended ball 54, a limiting ring 52, and a support block 53. In this example, the valve body 51 is cylindrical, the limiting ring 52 is connected to the inner wall of the valve body 51, and the support block 53 is connected to the inner wall of the valve body 51. At least one side of the support block 53 is spaced from the inner wall of the valve body 51, forming a liquid passage. The support block 53 and the limiting ring 52 are spaced apart, and the support block 53 is located below the limiting ring 52. The suspended ball 54 is located between the limiting ring 52 and the support block 53 and can move up and down between the limiting ring 52 and the support block 53. When the one-way valve 5 moves downward with low-frequency pulsation, the suspended ball 54 does not move with the valve body 51 or lags behind the movement of the valve body 51, causing the suspended ball 54 to abut against the annular hole of the limiting ring 52, blocking the coolant 91 from passing through the limiting ring 52, thus achieving the one-way valve 5's circuit breaking. At the same time, when the one-way valve 5 moves upward with low-frequency pulsation, the suspended ball 54 disengages from the annular hole of the limiting ring 52, allowing the one-way valve 5 to pass through.

[0080] Of course, in some other embodiments, the one-way valve 5 can also be integrated into other parts of the coolant passage, for example, the tool 6 can be used as the valve body of the one-way valve.

[0081] In some embodiments, the support block 53 is elongated, with one opposite end connected to the inner wall of the valve body 51, and the other opposite end spaced apart from the inner wall of the valve body 51, forming two fluid passages. That is, when the one-way valve is in operation, coolant flows through both sides of the support block 53.

[0082] In some examples, the two ends of the one-way valve 5 are threadedly connected to the luffing rod cutter connector 4 and the cutter 6, respectively. In another example, the luffing rod cutter connector 4 and the cutter 6 are connected by a spring clip, with the one-way valve 5 disposed within the spring clip and its two ends communicating with the luffing rod cutter connector 4 and the cutter 6, respectively. Preferably, the spring clip is a clip with high-pressure sealing performance.

[0083] See in some examples Figure 1 As shown, the low-frequency pulsation unit 2 includes a flat ring 21, rollers 22, a track ring 23, a roller cage 24, a bearing 25, an elastic connector 26, a spring 27, and a transducer connector 28. The roller cage 24 has a U-shaped shell and is fixedly connected to the machining center 100. The outer periphery of the flat ring 21 is fixedly connected to the roller cage 24. The central rotating shaft 1 is rotatably connected to the inner side of the flat ring 21 through the bearing 25. The elastic connector 26 is located below the flat ring 21, with one end coaxially connected to the central rotating shaft 1 and the other end coaxially connected to the track ring 23. The rollers 22 are located between the flat ring 21 and the track ring 23. Multiple rollers 22 are spatially symmetrically arranged along the center line of the central rotating shaft 1. The track ring 23 has a sinusoidal curved surface track on the side that contacts the rollers 22. Multiple springs 27 are located between the track ring 23 and the bottom plate of the roller cage 24 to provide elastic support for the track ring 23. A planar bearing (not shown in the figure) is provided on the lower side of the track ring 23. One end of the spring 27 is fixedly connected to the base plate of the roller cage 24, and the other end is fixedly connected to the loose ring of the planar bearing. One end of the transducer connector 28 passes through the tight ring of the planar bearing and is coaxially connected to the track ring 23. The other end passes through the base plate of the roller cage 24 and is connected to the elliptical ultrasonic transducer 3. The elastic connector 26, the track ring 23, the tight ring of the planar bearing, and the transducer connector 28 rotate with the central rotating shaft 1. The planar ring 21, the roller cage 24, and the spring 27 do not rotate. When the roller 22 is at the peak of the sine wave, the track ring 23 moves downward. When it is at the trough of the sine wave, the track ring 23 resets and moves upward. That is, when the track ring 23 rotates, it generates a reciprocating motion along the axial direction of the central rotating shaft 1. At this time, the elastic connector 26 deforms accordingly to adapt to the up-and-down reciprocating motion of the track ring 23. The number of axial vibrations of the track loop 23 is related to the number of sinusoidal waveforms contained in the track loop 23. For example, if the track loop 23 contains n sinusoidal waveforms, then the number of axial vibrations of the track loop 23 is n times per revolution. Preferably, the multiple springs 27 are spatially symmetrically arranged along the center line of the central axis 1.

[0084] In one example, the planar bearing is embedded inside the track ring 3. Optionally, the resilient connector 26 is connected to the tight ring of the planar bearing.

[0085] In one example, the roller cage 24 is fixedly connected to the machining center 100 via a stop bracket 103. The main function of the stop bracket 103 is connection and fixation; it is only necessary to meet the usage requirements and is not limited here. It should be noted that... Figure 1 In order to reflect the cooperation between roller 22 and track ring 23, the structure of roller cage 24 has been simplified and the structure of limiting roller 22 is not reflected. This simplified structure is a common structure of existing roller cages, and the existing structure can be used, so it will not be described in detail again.

[0086] In one example, the elastic connector 26 is a spring structure and is in an axially tensioned state. Based on this state, it adapts to the axial reciprocating motion of the trajectory ring 23 to make axial changes.

[0087] See Figure 7 As shown, in one example, the roller cage 24 is annular and located between the flat ring 21 and the track ring 23, featuring a simple structure and convenient installation. In use, the flat ring 21 and the roller cage 24 are connected to the transducer connector 28 via a bearing, and the rollers 22 are installed within the roller cage 24. Specifically, the flat ring 21 and the roller cage 24 are connected to the outer ring of the bearing, the transducer connector 28 is connected to the inner ring of the bearing, and the elastic connector 26 is connected to the inner ring of the bearing.

[0088] In one example, the transducer connector 28 is a columnar structure, and the end connected to the elliptical ultrasonic transducer 3 has a flange structure. A sealing ring 29 is fitted on the outside of the transducer connector 28, and the sealing ring 29 is located between the flange structure and the bottom plate of the roller cage 24, which reduces coolant leakage on the one hand and dust entry on the other.

[0089] In some examples, tool 6 is a diamond nesting drill (see...). Figure 4 (as shown) or diamond grinding wheel. Figure 4 In the diamond bushing drill, there are abrasive grains 61, and the inside of the diamond bushing drill is a core 202.

[0090] In some examples, the ultrasonic drive power supply 8 is connected to the elliptical ultrasonic transducer 3 via an aviation connector 31 or a direct circuit connection. The aviation connector 31 is fixed relative to the machining center 100 and does not rotate.

[0091] In this embodiment, the high-pressure cooling pump 10 can be a high-pressure oil pump, and the high-pressure cooling pressure can be set to 4-20 MPa.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that not every embodiment contains only one independent technical solution, and in the absence of conflict between solutions, the various technical features mentioned in each embodiment can be combined in any way to form other implementation methods that can be understood by those skilled in the art.

[0093] Furthermore, without departing from the scope of the present invention, modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, shall not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhanced machining system, comprising a central rotating shaft, a low-frequency pulsating section, an elliptical ultrasonic transducer, an amplitude transformer tool connector, a one-way valve, a tool, an ultrasonic drive power supply, and a controller. The central rotating shaft, low-frequency pulsating section, elliptical ultrasonic transducer, amplitude transformer tool connector, one-way valve, and tool are connected sequentially. The central rotating shaft is used to connect to the spindle of a machining center. The low-frequency pulsating section enables the tool to generate low-frequency pulsation in the axial direction. The elliptical ultrasonic transducer enables the tool to generate axial and radial ultrasonic vibrations. The ultrasonic drive power supply is connected to the elliptical ultrasonic transducer. The controller is signal-connected to the ultrasonic drive power supply and the control unit of the machining center. in, The central rotating shaft, low-frequency pulsating part, elliptical ultrasonic transducer, amplitude rod tool connector and tool all have axial through holes. After the central rotating shaft, low-frequency pulsating part, elliptical ultrasonic transducer, amplitude rod tool connector, one-way valve and tool are connected, their respective axial through holes are connected to the one-way valve to form a coolant channel. When the tool moves upward with low-frequency pulsation, the one-way valve is open and the coolant flows into the cutting area. When the tool moves downward with low-frequency pulsation, the one-way valve is closed. During machining, the tool is simultaneously subjected to axial and radial ultrasonic vibrations as well as axial low-frequency pulsations, with the amplitude of the low-frequency pulsations being greater than the amplitude of the axial ultrasonic vibrations. The tool has an axially arranged through hole for coolant to pass through. When the tool moves upward with low-frequency pulsation, a momentary low pressure is formed in the cutting zone. Coolant is supplied to the cutting zone through the tool, and coolant located on the outside of the tool flows back to the cutting zone. When the cutting tool moves downwards with low-frequency pulsation, the supply of coolant to the cutting zone stops, and instantaneous high pressure is formed in the cutting zone. The coolant moves out of the channel through the gap between the cutting tool and the workpiece.

2. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 1, characterized in that: The one-way valve includes a valve body, a suspended ball, a limiting ring, and a support block. The limiting ring is connected to the inner wall of the valve body, and the support block is also connected to the inner wall of the valve body. At least one side of the support block is spaced from the inner wall of the valve body to form a liquid passage. The support block is spaced apart from the limiting ring and is located below the limiting ring. The suspended ball is located between the limiting ring and the support block and can move up and down between the limiting ring and the support block. When the suspended ball abuts against the annular hole of the limiting ring, the one-way valve is open. When the suspended ball disengages from the annular hole of the limiting ring, the one-way valve is open.

3. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 2, characterized in that: One opposite end of the support block is connected to the inner wall of the valve body, and the other opposite end is spaced apart from the inner wall of the valve body, forming two liquid passages.

4. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 1, characterized in that: The low-frequency pulsating section includes a flat ring, rollers, a track ring, a roller cage, a bearing, an elastic connector, a spring, and a transducer connector. The roller cage is fixedly connected to the machining center. The outer circumference of the flat ring is fixedly connected to the roller cage. The central rotating shaft is rotatably connected to the inner side of the flat ring via the bearing. The elastic connector is located below the flat ring, with one end coaxially connected to the central rotating shaft and the other end coaxially connected to the track ring. The rollers are located between the flat ring and the track ring. Multiple rollers are spatially symmetrically arranged along the centerline of the central rotating shaft. The track ring has a sinusoidal curved surface track on the side that contacts the rollers. Multiple springs are located between the track ring and the base plate of the roller cage to provide elastic support for the track ring. A plane bearing is provided on the lower side of the track ring. One end of each spring is fixedly connected to the base plate of the roller cage, and the other end is fixedly connected to the loose ring of the plane bearing. One end of the transducer connector passes through the tight ring of the plane bearing and is coaxially connected to the track ring. The other end passes through the base plate of the roller cage and is connected to the elliptical ultrasonic transducer. The elastic connector, track ring, tight ring of the plane bearing, and transducer connector rotate with the central rotating shaft, and the track ring generates a reciprocating motion along the axial direction of the central rotating shaft during rotation.

5. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 4, characterized in that: The roller cage is fixedly connected to the machining center via a stop bracket.

6. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 4, characterized in that: The transducer connector is a columnar structure, and the end connected to the elliptical ultrasonic transducer has a flange structure. A sealing ring is fitted on the outside of the transducer connector, and the sealing ring is located between the flange structure and the bottom plate of the roller cage.

7. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 1, characterized in that: The two ends of the one-way valve are respectively threadedly connected to the amplitude transformer cutter connector and the cutter; or The amplitude rod cutter connector is connected to the cutter via a spring clip. The one-way valve is located inside the spring clip and its two ends are respectively connected to the amplitude rod cutter connector and the cutter.

8. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 1, characterized in that: The cutting tool is a diamond nesting drill or a diamond grinding wheel.

9. The ceramic matrix composite micro-deep hole complex frequency pulsating chip removal enhancement machining system according to claim 1, characterized in that: The ultrasonic drive power supply is connected to the elliptical ultrasonic transducer via an aviation plug or a direct circuit connection.

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