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

Abstract

The invention relates to a ceramic matrix composite micro-deep hole multi-frequency pulsating chip removal enhanced machining method and system. According to the method, axial and radial ultrasonic vibration and axial low-frequency pulsation are simultaneously generated on a tool during machining, wherein the amplitude of the low-frequency pulsation is greater than that of the axial ultrasonic vibration. A through hole which is axially formed and allows cooling liquid to pass through is formed in the tool, when the tool moves upwards in a low-frequency pulsation mode, instantaneous low pressure is formed in a cutting area, the cooling liquid is provided for the cutting area through the tool, and the cooling liquid located on the outer side of the tool flows back to the cutting area. When the tool moves downwards in a low-frequency pulsation mode, the cooling liquid is stopped from being provided for the cutting area, instantaneous high pressure is formed in the cutting area, the cooling liquid moves towards the outside of a gap channel between the tool and a workpiece through the gap channel, meanwhile, the cooling liquid is matched with ultrasonic radial vibration, the width of the gap channel is periodically increased, and chip removal is promoted. According to the method, the machining quality is greatly improved, the service life of the tool is greatly prolonged, meanwhile, efficient chip removal is achieved, and the purpose of efficient and high-quality micro-deep hole machining of ceramic materials is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of material processing, and in particular to a method and system for enhancing micro-deep hole processing of ceramic-based composite materials with complex-frequency pulsating chip removal. Background Art

[0002] The extensive application of ceramic-based composite materials is an important development trend in the field of aerospace manufacturing. Due to the excellent properties of ceramic-based composite materials such as light weight, high strength, high modulus, wear resistance or high and low temperature resistance, the demand for ceramic-based composite materials in the aerospace field is growing, and the proportion of ceramic-based composite materials in the total amount of materials used in the aerospace field is gradually increasing. With the extensive application of new materials, new technologies, and new structures in various types of equipment, the structural shapes of parts have become more complicated, and the cutting difficulty of difficult-to-process structures (micro holes, inclined holes, and deep holes, etc.) has increased day by day, and the quality of holes (position accuracy, aperture accuracy, etc.) and processing efficiency have become higher and higher. The application of a large number of advanced materials has made the manufacturability of parts tend to be extreme, providing new opportunities for the development of manufacturing technology.

[0003] At present, traditional processing technology faces difficulties in improving the quality and efficiency of micro deep hole processing of ceramic matrix composite materials. The characteristics of deep hole processing technology and the high requirements for processing accuracy make it particularly difficult to drill deep holes with large aspect ratios in ceramic matrix composite materials. The main problems that need to be solved are as follows:

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

[0005] (2) Deep hole processing is a semi-closed processing, the tool and the hole wall are severely squeezed, the temperature in the cutting area is high, and the cutting force and torque are too large, which will cause serious tool wear and easy tool breakage and failure;

[0006] (3) The chips from deep hole drilling can easily clog the chip grooves, causing secondary cutting of the processed hole surface, resulting in surface defects, affecting the hole processing accuracy and even causing tool breakage, which greatly affects the processing efficiency;

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

[0008] Therefore, there is an urgent need to solve the problems existing in the traditional processing methods in the processing of micro-holes and deep holes of ceramic-based composite materials, especially the processing of micro-deep holes. Summary of the invention

[0009] The purpose of the present invention is to provide a method and system for enhanced processing of micro-deep holes of ceramic-based composite materials with complex-frequency pulsating chip removal, so as to solve at least one technical problem existing in the background technology.

[0010] In order to achieve the above-mentioned object, in the first aspect, the present invention provides a method for enhanced chip removal by complex-frequency pulsation for micro-deep hole processing of ceramic-based composite materials, wherein during processing, the tool is subjected to axial and radial ultrasonic vibrations and axial low-frequency pulsation at the same time, wherein the amplitude of the low-frequency pulsation is greater than the amplitude of the axial ultrasonic vibration;

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

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

[0013] In a second aspect, the present invention further provides a ceramic-based composite micro-deep hole complex-frequency pulsating chip removal enhanced processing system, which is used to implement the ceramic-based composite micro-deep hole complex-frequency pulsating chip removal enhanced processing method of the first aspect, comprising a central rotating shaft, a low-frequency pulsating part, an elliptical ultrasonic transducer, a horn tool connector, a one-way valve, a tool, an ultrasonic drive power supply and a controller, wherein the central rotating shaft, the low-frequency pulsating part, the elliptical ultrasonic transducer, the horn tool connector, the one-way valve and the tool are connected in sequence, the central rotating shaft is used to be connected to the main shaft of the machining center, the low-frequency pulsating part can cause the tool to pulsate at a low frequency in the axial direction, the elliptical ultrasonic transducer can cause the tool to ultrasonically vibrate in the axial and radial directions, the ultrasonic drive power supply is connected to the elliptical ultrasonic transducer, and the controller is connected to the ultrasonic drive power supply and the control part signal of the machining center;

[0014] Among them, the central rotating shaft, low-frequency pulsation part, elliptical ultrasonic transducer, amplitude-variable rod tool connector and tool all have axial through holes. After the central rotating shaft, low-frequency pulsation part, elliptical ultrasonic transducer, amplitude-variable 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 due to low-frequency pulsation, the one-way valve opens the channel and the coolant flows into the cutting area. When the tool moves downward due to low-frequency pulsation, the one-way valve opens the circuit.

[0015] Optionally, the one-way valve includes a valve body, a suspension ball, a limit ring and a support block, the limit ring is connected to the inner wall of the valve body, the support block is connected to the inner wall of the valve body, and 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 limit ring are spaced apart, and the support block is located on the lower side of the limit ring, the suspension ball is located between the limit ring and the support block, and can move up and down between the limit ring and the support block, when the suspension ball is against the ring hole of the limit ring, the one-way valve is disconnected, and when the suspension ball is out of the ring hole of the limit ring, the one-way valve is opened.

[0016] Optionally, two opposite ends of the support block are respectively connected to the inner wall of the valve body, and the other two opposite ends are spaced apart from the inner wall of the valve body to form two liquid passages.

[0017] Optionally, the low-frequency pulsation part includes a flat ring, a roller, 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 periphery of the flat ring is fixedly connected to the roller cage, the central shaft is rotatably connected to the inner side of the flat ring through a bearing, the elastic connector is located below the flat ring, one end of the elastic connector is coaxially connected to the central shaft, and the other end is coaxially connected to the track ring. The roller is located between the flat ring and the track ring, and a plurality of rollers are symmetrically arranged in space along the center line of the central shaft. A sinusoidal waveform curved track is provided on the side of the track ring in contact with the roller. A plurality of springs are located between the track ring and the bottom plate of the roller retainer 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 bottom plate of the roller retainer, 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, and the other end passes through the bottom plate of the roller retainer and is connected to the elliptical ultrasonic transducer. The elastic connector, the track ring, the tight ring of the plane bearing and the transducer connector rotate with the central shaft, and the track ring generates an axial reciprocating motion along the central shaft when rotating.

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

[0019] Optionally, the transducer connector is a columnar structure, and one end connected to the elliptical ultrasonic transducer has a flange structure. A sealing ring is sleeved on the outer side of the transducer connector, and the sealing ring is located between the flange structure and the bottom plate of the roller retainer.

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

[0021] The amplitude change rod tool connecting piece is connected to the tool through a spring jacket, and the one-way valve is arranged in the spring jacket, and the two ends of the one-way valve are respectively communicated with the amplitude change rod tool connecting piece and the tool.

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

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

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

[0025] The ceramic-based composite micro-deep hole complex frequency pulsation chip removal enhanced processing method provided by the present invention causes the tool to simultaneously generate axial and radial ultrasonic vibrations and axial low-frequency pulsations during processing, wherein the amplitude of the low-frequency pulsations is greater than the amplitude of the axial ultrasonic vibrations. On this basis, the tool has an axially arranged through hole for the coolant to pass through, and when the tool moves upward due to low-frequency pulsations, an instantaneous low pressure is formed in the cutting zone, and the coolant is provided to the cutting zone through the tool, and the coolant located on the outside of the tool flows back to the cutting zone. When the tool moves downward due to low-frequency pulsations, the supply of coolant to the cutting zone is stopped, and an instantaneous high pressure is formed in the cutting zone, and the coolant moves out of the channel 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 by generating radial ultrasonic vibrations in the tool. In addition, radial ultrasonic vibration is coordinated with the low-frequency pulse vibration of the tool and the control of the coolant by the one-way valve. The chips are discharged out of the hole in a pulsating manner under the axial low-frequency pulsation, so that the vibration interface of the tool is timely and fully cooled and lubricated. Ultrasonic frequency separation is used to reduce force and heat in the machining process, greatly improving the machining quality and tool life, while achieving efficient chip removal, achieving the purpose of efficient and high-quality micro-deep hole machining of ceramic materials.

[0026] The invention provides a ceramic-based composite micro-deep hole complex frequency pulsation chip removal enhanced processing system, wherein the central shaft, the low-frequency pulsation part, the elliptical ultrasonic transducer, the amplitude rod tool connector and the tool all have axial through holes, and the respective axial through holes are connected to a one-way valve to form a coolant channel. The one-way valve is located between the amplitude rod tool connector and the tool as an on-off control structure of the coolant channel. The coolant channel is connected to the coolant tank through a high-pressure cooling pump. When the tool moves upward due to low-frequency pulsation, the one-way valve is opened, and the coolant flows into the cutting area from the outer circulation channel and the inner circulation channel to achieve cooling and lubrication. When the tool moves downward due to low-frequency pulsation, the one-way valve is disconnected, and an instantaneous pulse high pressure is formed in the cutting area, and the coolant carries the chips through the gap channel between the tool and the workpiece to move out of the hole, and because the tool also generates radial ultrasonic vibration during the processing, the chip removal space can be periodically increased, and efficient chip removal can be further achieved, and the overall structure is simple, the processing accuracy is high, and the purpose of efficient and high-quality micro-deep hole processing of ceramic materials can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 1 Schematic diagram of the structure of a ceramic-based composite material micro-deep hole complex-frequency pulsating chip removal enhanced processing system in an embodiment of the present invention;

[0029] Figure 2 It is an enlarged schematic diagram of a processing area in a micro-deep hole processing process of a ceramic-based composite material according to an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the principle of suppressing tool chatter by low-frequency pulsation in an embodiment of the present invention;

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

[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 an off-circuit state in an embodiment of the present invention;

[0034] Figure 7 The present invention is a schematic diagram of the structure of a flat ring, a roller, a track ring and a roller retainer in cooperation with each other in an embodiment of the present invention.

[0035] In the figure:

[0036] 100: machining center;

[0037] 101: spindle;

[0038] 102: Machining center control unit;

[0039] 103: stop frame;

[0040] 200: Workpiece;

[0041] 201: Chips;

[0042] 202: core material;

[0043] 300: flow direction arrow;

[0044] 1: Center axis;

[0045] 2: Low frequency pulsation part;

[0046] 21: flat ring;

[0047] 22: roller;

[0048] 23: track ring;

[0049] 24: roller cage;

[0050] 25: bearing;

[0051] 26: elastic connector;

[0052] 27: Spring;

[0053] 28: Transducer connector;

[0054] 29: Sealing ring;

[0055] 3: Elliptical ultrasonic transducer;

[0056] 31: Aviation plug;

[0057] 4: Luffing rod tool connection piece;

[0058] 5: One-way valve;

[0059] 51: valve body;

[0060] 52: Limiting ring;

[0061] 53: support block;

[0062] 54: suspended ball;

[0063] 6: Knife;

[0064] 61: abrasive particles;

[0065] 7: Controller;

[0066] 8: Ultrasonic driving power supply;

[0067] 9: Coolant tank;

[0068] 91: Coolant;

[0069] 10: High-pressure cooling pump. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 the internal communication of 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.

[0072] In the prior art, due to the closed cutting area during deep hole processing, the conventional solution requires the use of high-pressure cutting fluid to break the chips, and the chips are discharged with the special high-pressure cutting fluid flow. It is difficult to use traditional high-pressure cutting fluid in the processing of tiny holes (diameter ≤ 1.0mm) of hard and brittle materials of ceramic-based composite materials, and the chip removal space is small, which affects the chip removal effect of conventional hole making.

[0073] The ceramic-based composite micro-deep hole complex frequency pulsation chip removal enhanced processing method provided by the embodiment of the present invention causes the tool to simultaneously generate axial and radial ultrasonic vibrations and axial low-frequency pulsations during processing, wherein the amplitude of the low-frequency pulsations is greater than the amplitude of the axial ultrasonic vibrations. On this basis, the tool has an axially arranged through hole for the coolant to pass through, and when the tool moves upward due to low-frequency pulsations, an instantaneous low pressure is formed in the cutting zone, and the coolant is provided to the cutting zone through the tool, and the coolant located on the outside of the tool flows back to the cutting zone. When the tool moves downward due to low-frequency pulsations, the supply of coolant to the cutting zone is stopped, and an instantaneous high pressure is formed in the cutting zone, and the coolant moves out of the channel 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 by generating radial ultrasonic vibrations of the tool. In addition, radial ultrasonic vibration is coordinated with the low-frequency pulse vibration of the tool and the control of the coolant by the one-way valve. The chips are discharged out of the hole in a pulsating manner under the axial low-frequency pulsation, so that the vibration interface of the tool is timely and fully cooled and lubricated. Ultrasonic frequency separation is used to reduce force and heat in the machining process, greatly improving the machining quality and tool life, while achieving efficient chip removal, achieving the purpose of efficient and high-quality micro-deep hole machining of ceramic materials.

[0074] The following further illustrates the ceramic-based composite material micro-deep hole complex frequency pulsation chip removal enhanced processing method and the technical effect achieved by the present invention in combination with an example of a ceramic-based composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system that can realize the above-mentioned ceramic-based composite material micro-deep hole complex frequency pulsation chip removal enhanced processing method.

[0075] See also Figure 1As shown, the ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system includes a central shaft 1, a low-frequency pulsation part 2, an elliptical ultrasonic transducer 3, a horn tool connector 4, a one-way valve 5, a tool 6, an ultrasonic drive power supply 8 and a controller 7. The central shaft 1, the low-frequency pulsation part 2, the elliptical ultrasonic transducer 3, the horn tool connector 4, the one-way valve 5 and the tool 6 are connected in sequence. The central shaft 1 is used to be connected to the main shaft 101 of the machining center 100. The low-frequency pulsation part 2 can cause the tool 6 to pulsate at a low frequency in the axial direction. The elliptical ultrasonic transducer 3 can cause the tool 6 to vibrate ultrasonically in the axial and radial directions. The ultrasonic drive power supply 8 is connected to the elliptical ultrasonic transducer 3 to adjust the amplitude of the ultrasonic vibration. The controller 7 is connected to the ultrasonic drive power supply 8 and the machining center control part 102 for receiving or sending signals. In this embodiment, the controller 7 can be a computer.

[0076] The central shaft 1, the low-frequency pulsating part 2, the elliptical ultrasonic transducer 3, the horn tool connector 4 and the tool 6 all have axial through holes, and each axial through hole is connected to a one-way valve 5 to form a coolant channel. The one-way valve 5 is located between the horn tool connector 4 and the tool 6 as an on-off control structure of the coolant channel. The coolant channel is connected to the coolant tank 9 through a high-pressure cooling pump 10. Figure 5 As shown, when the tool 6 moves upward with low-frequency pulsation, the one-way valve 5 is opened, and the coolant 91 flows into the cutting area from the outer circulation channel and the inner circulation channel along the direction indicated by the flow arrow 300 to achieve cooling and lubrication. Figure 6 As shown, when the tool 6 pulsates downward at a low frequency, the one-way valve 5 is disconnected, and an instantaneous pulse high pressure is formed in the cutting area. The coolant 91 carries the chips 201 through the gap channel between the tool 6 and the workpiece 200 to move out of the hole to achieve chip removal. In addition, since the tool 6 also generates radial ultrasonic vibration during the machining process, the chip removal space can be periodically increased, further achieving efficient chip removal.

[0077] See also Figure 3 and Figure 4 As shown, assuming that the width of the gap channel in the non-vibration state is D, and the amplitude of the 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, thereby increasing the chip removal space.

[0078] In addition, since the tool 6 will generate low-frequency axial pulsation during the processing of the present invention, the tool 6 can be restrained from vibrating. Figure 3 As shown, in micro-deep hole machining, the tool 6 is subjected to an axial force F thMoreover, the tool 6 is long and thin, and is prone to chattering, which may cause scratches on the inner surface and lead to a decrease in processing quality. In the present embodiment, since the tool 6 may pulsate at a low frequency during processing with a relatively large amplitude (generally greater than 10 μm), during processing, the tool 6 and the processing channel of the workpiece 200 may undergo periodic reciprocating motions similar to drilling, separation, and re-drilling. In the separation stage, the tool 6 is separated from the processed material, no cutting motion occurs, and there is no external excitation input, so the tool 6 returns to stability. At the same time, the tool 6 is kept in the same or relatively close state each time it enters the processing channel, which plays a role in suppressing the deflection of the tool 6. On the other hand, ultrasonic frequency vibrations can suppress the occurrence of chattering, mainly for two reasons. First, ultrasonic frequency vibrations are a forced vibration, which will reduce the occurrence of self-excited chattering of the tool 6. Second, the drilling, separation, and re-drilling actions are superimposed with ultrasonic vibrations at the same time. The separation under the action of ultrasound will instantly remove the external excitation source and suppress chattering. It should be noted that Figure 3 The length of the tool 6 is shown in the figure. The tool 6 is shown in a simplified figure. The solid line between the two oblique dashed lines and the rectangle with a certain width at the bottom are all schematic diagrams of the tool 6. The upper part is simplified to lines, and the lower part shows the diameter of the tool 6. The oblique dashed line and the rectangular dashed line are schematic diagrams of the position where the tool undergoes radial ultrasonic vibration.

[0079] See also Figure 5 and Figure 6 As shown, in one example, the one-way valve 5 includes a valve body 51, a suspension ball 54, a limit ring 52 and a support block 53. In this example, the valve body 51 is cylindrical, the limit ring 52 is connected to the inner wall of the valve body 51, the support block 53 is connected to the inner wall of the valve body 51, and at least one side of the support block 53 is spaced from the inner wall of the valve body 51 to form a liquid passage. The support block 53 is spaced from the limit ring 52, and the support block 53 is located at the lower side of the limit ring 52. The suspension ball 54 is located between the limit ring 52 and the support block 53, and can move up and down between the limit ring 52 and the support block 53. When the one-way valve 5 moves downward with low-frequency pulsation, the suspension ball 54 does not move with the valve body 51 or lags behind the movement of the valve body 51, so that the suspension ball 54 abuts against the ring hole of the limit ring 52, blocking the coolant 91 from passing through the limit ring 52, that is, the one-way valve 5 is disconnected. At the same time, when the one-way valve 5 moves upward with low-frequency pulsation, the suspension ball 54 is separated from the ring hole of the limit ring 52, so that the one-way valve 5 is open.

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

[0081] In some embodiments, the support block 53 is in the shape of a strip, with two opposite ends connected to the inner wall of the valve body 51, and the other two opposite ends are spaced from the inner wall of the valve body 51 to form two liquid passages. That is, when the one-way valve is open, the coolant flows through both sides of the support block 53.

[0082] In some examples, both ends of the one-way valve 5 are respectively threadedly connected to the horn tool connector 4 and the tool 6. In another example, the horn tool connector 4 and the tool 6 are connected through a spring jacket, and the one-way valve 5 is arranged in the spring jacket, and both ends are respectively connected to the horn tool connector 4 and the tool 6. Preferably, the spring jacket adopts a jacket with high-pressure sealing performance.

[0083] For some examples, see Figure 1 As shown, the low-frequency pulsation part 2 includes a flat ring 21, a roller 22, a track ring 23, a roller retainer 24, a bearing 25, an elastic connector 26, a spring 27 and a transducer connector 28. The roller retainer 24 adopts a shell shape with a U-shaped cross-section and is fixedly connected to the machining center 100. The outer periphery of the flat ring 21 is fixedly connected to the roller retainer 24. The central 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, and one end is coaxially connected to the central shaft 1, and the other end is coaxially connected to the track ring 23. The roller 22 is located between the flat ring 21 and the track ring 23. A plurality of rollers 22 are symmetrically arranged in space along the center line of the central shaft 1. A sinusoidal curved track is provided on the side of the track ring 23 in contact with the roller 22. A plurality of springs 27 are located between the track ring 23 and the bottom plate of the roller retainer 24 to provide elastic support for the track ring 23. A plane 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 bottom plate of the roller retainer 24, and the other end is fixedly connected to the loose ring of the plane bearing. One end of the transducer connector 28 passes through the tight ring of the plane bearing and is coaxially connected to the track ring 23, and the other end passes through the bottom plate of the roller retainer 24 and is connected to the elliptical ultrasonic transducer 3. The elastic connector 26, the track ring 23, the tight ring of the plane bearing and the transducer connector 28 rotate with the central shaft 1, and the flat ring 21, the roller retainer 24 and the spring 27 do not rotate. When the roller 22 is at the peak of the sinusoidal waveform, the track ring 23 moves downward, and when it is at the trough of the sinusoidal waveform, the track ring 23 returns to move upward, that is, the track ring 23 generates an axial reciprocating motion along the central shaft 1 when rotating, and at this time, the elastic connector 26 undergoes corresponding deformation to adapt to the up and down reciprocating motion of the track ring 23. The number of axial vibrations of the track ring 23 is related to the number of sinusoidal waveforms contained in the track ring 23. For example, if the track ring 23 contains n sinusoidal waveforms, the number of axial vibrations of the track ring 23 is n times per revolution. Preferably, the plurality of springs 27 are spatially symmetrically arranged along the center line of the central shaft 1.

[0084] In one example, the plane bearing is embedded in the track ring 3. Optionally, the elastic connecting member 26 is connected to the tightening ring of the plane bearing.

[0085] In one example, the roller retainer 24 is fixedly connected to the machining center 100 via the stop frame 103. The stop frame 103 is mainly used for connection and fixing, and is not limited here as long as it meets the use requirements. It should be noted that Figure 1 In order to reflect the matching relationship between the roller 22 and the track ring 23, the structure of the roller retainer 24 is simplified, and the structure of the limiting roller 22 is not reflected. The simplified structure is a common structure of the existing roller retainer, and the existing structure can be used and will not be repeated.

[0086] In one example, the elastic connecting member 26 is a spring structure and is in an axially tensioned state, and based on this state, it adapts to the axial reciprocating motion of the track ring 23 to undergo axial changes.

[0087] See also Figure 7 As shown, in one example, the roller cage 24 is annular and is located between the flat ring 21 and the track ring 23, with a simple structure and convenient installation. When in use, the flat ring 21 and the roller cage 24 are connected to the transducer connector 28 through the bearing, and the roller 22 is installed in 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 one end connected to the elliptical ultrasonic transducer 3 has a flange structure. A sealing ring 29 is sleeved on the outer side of the transducer connector 28, and the sealing ring 29 is located between the flange structure and the bottom plate of the roller retainer 24, which reduces the leakage of coolant on the one hand and reduces the entry of dust on the other hand.

[0089] In some examples, the tool 6 is a diamond drill (see Figure 4 shown) or diamond grinding wheel. Figure 4 In the figure, abrasive grains 61 are arranged on the diamond drill, and the interior of the diamond drill is a core 202 .

[0090] In some examples, the ultrasonic driving power supply 8 and the elliptical ultrasonic transducer 3 are connected via an aviation plug 31 or directly connected via a circuit. The aviation plug 31 and the machining center 100 are relatively fixed and do not rotate.

[0091] In this embodiment, the high-pressure cooling pump 10 may be a high-pressure oil pump, and the high-pressure cooling pressure may be set at 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, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that not every embodiment contains only one independent technical solution. In the absence of a conflict of solutions, the various technical features mentioned in each embodiment can be combined in any manner to form other implementation methods that can be understood by those skilled in the art.

[0093] In addition, without departing from the scope of the present invention, the technical solutions described in the aforementioned embodiments may be modified, or some of the technical features may be replaced by equivalents, without causing the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for enhancing chip removal by complex frequency pulsation in micro-deep hole processing of ceramic-based composite materials, characterized in that: During machining, the tool is made to simultaneously generate axial and radial ultrasonic vibrations and axial low-frequency pulsations, wherein the amplitude of the low-frequency pulsations is 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 in a low-frequency pulsating motion, an instantaneous low pressure is formed in the cutting zone, and coolant is supplied to the cutting zone through the tool, and the coolant on the outside of the tool flows back to the cutting zone; When the tool moves downward in low-frequency pulsation, the supply of coolant to the cutting zone stops, an instantaneous high pressure is formed in the cutting zone, and the coolant moves out of the channel through the gap channel between the tool and the workpiece.

2. A ceramic-based composite micro-deep hole complex-frequency pulsating chip removal enhanced processing system, used to implement the ceramic-based composite micro-deep hole complex-frequency pulsating chip removal enhanced processing method according to claim 1, comprising a central rotating shaft, a low-frequency pulsating part, an elliptical ultrasonic transducer, a horn tool connector, a one-way valve, a tool, an ultrasonic drive power supply and a controller, wherein the central rotating shaft, the low-frequency pulsating part, the elliptical ultrasonic transducer, the horn tool connector, the one-way valve and the tool are connected in sequence, the central rotating shaft is used to be connected to the main shaft of the machining center, the low-frequency pulsating part can cause the tool to pulsate at a low frequency in the axial direction, the elliptical ultrasonic transducer can cause the tool to ultrasonically vibrate in the axial and radial directions, the ultrasonic drive power supply is connected to the elliptical ultrasonic transducer, and the controller is connected to the ultrasonic drive power supply and the control part of the machining center by signal; in, The central rotating shaft, low-frequency pulsation part, elliptical ultrasonic transducer, amplitude-variable rod tool connector and tool all have axial through holes. After the central rotating shaft, low-frequency pulsation part, elliptical ultrasonic transducer, amplitude-variable 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 due to low-frequency pulsation, the one-way valve opens the channel and the coolant flows into the cutting area. When the tool moves downward due to low-frequency pulsation, the one-way valve opens the circuit.

3. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 2, characterized in that: The one-way valve includes a valve body, a suspension ball, a limit ring and a support block, the limit ring is connected to the inner wall of the valve body, the support block is connected to the inner wall of the valve body, and 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 limit ring are spaced apart, and the support block is located at the lower side of the limit ring, the suspension ball is located between the limit ring and the support block, and can move up and down between the limit ring and the support block, when the suspension ball is against the ring hole of the limit ring, the one-way valve is disconnected, and when the suspension ball is separated from the ring hole of the limit ring, the one-way valve is open.

4. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 3, characterized in that: Two opposite ends of the support block are respectively connected to the inner wall of the valve body, and the other two opposite ends are spaced apart from the inner wall of the valve body to form two liquid passages.

5. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 2, characterized in that: The low-frequency pulsation part includes a flat ring, a roller, a track ring, a roller retainer, a bearing, an elastic connector, a spring and a transducer connector. The roller retainer is fixedly connected to the machining center, the outer periphery of the flat ring is fixedly connected to the roller retainer, the central shaft is rotatably connected to the inner side of the flat ring through the bearing, the elastic connector is located below the flat ring, and one end is coaxially connected to the central shaft, and the other end is coaxially connected to the track ring, the roller is located between the flat ring and the track ring, a plurality of the rollers are spatially symmetrically arranged along the center line of the central shaft, and a sinusoidal waveform curved track is provided on the side of the track ring in contact with the roller , multiple springs are located between the track ring and the bottom plate of the roller retainer to provide elastic support for the track ring, a plane bearing is provided on the lower side of the track ring, one end of the spring is fixedly connected to the bottom plate of the roller retainer, and the other end is fixedly connected to the loose ring of the plane bearing, one end of the transducer connecting piece passes through the tight ring of the plane bearing and is coaxially connected to the track ring, and the other end passes through the bottom plate of the roller retainer and is connected to the elliptical ultrasonic transducer, the elastic connecting piece, the track ring, the tight ring of the plane bearing and the transducer connecting piece rotate with the central shaft, and the track ring generates an axial reciprocating motion along the central shaft when rotating.

6. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 5, characterized in that: The roller retaining frame is fixedly connected to the machining center via a stop frame.

7. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 5, characterized in that: The transducer connector is a columnar structure, and one end connected to the elliptical ultrasonic transducer has a flange structure. A sealing ring is sleeved on the outer side of the transducer connector, and the sealing ring is located between the flange structure and the bottom plate of the roller retainer.

8. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 2, characterized in that: The two ends of the one-way valve are respectively connected to the amplitude change rod tool connecting piece and the tool threadedly; or The amplitude-changing rod tool connecting piece is connected to the tool via a spring jacket, the one-way valve is arranged in the spring jacket, and two ends of the one-way valve are respectively communicated with the amplitude-changing rod tool connecting piece and the tool.

9. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 2, characterized in that: The tool is a diamond drill or a diamond grinding wheel.

10. The ceramic matrix composite material micro-deep hole complex frequency pulsation chip removal enhanced processing system according to claim 2, characterized in that: The ultrasonic driving power supply is connected to the elliptical ultrasonic transducer via an aviation plug or a direct circuit connection.

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