A diamond tool with self-sensing cutting force and cutting temperature and a manufacturing method thereof

Abstract

The present invention discloses a diamond tool capable of self-sensing cutting force and cutting temperature, and a method for manufacturing the same. In this diamond tool, sensors are integrated with the tool. A temperature sensor is located on the upper surface of the single-crystal diamond tool, near the front cutting edge, and a cutting force sensor is located on the side of the single-crystal diamond tool, near the front cutting edge. This allows for in-situ measurement of cutting temperature and cutting force during the cutting process. Both sensors are based on single-crystal diamond and are doped with boron. Boron-doped diamond semiconductor materials have a high piezoresistive coefficient, resulting in highly sensitive sensors that can accurately measure even the smallest cutting forces and slight temperature changes encountered during precision and ultraprecision machining. This structure enables measurement without changing the original tool's shape, and offers high measurement accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of cutting tool measurement, and relates to a diamond tool capable of self-sensing cutting force and cutting temperature and a manufacturing method thereof. Background Art

[0002] Diamond cutting tools offer exceptional hardness and wear resistance, low friction, a high elastic modulus, high thermal conductivity, a low thermal expansion coefficient, and low affinity for non-ferrous metals. They are suitable for precision machining of hard and brittle non-metallic materials such as graphite, highly wear-resistant materials, composite materials, high-silicon aluminum alloys, and other tough non-ferrous metals, producing ultra-smooth surfaces (roughness Ra 0.02–0.005 μm, with machining accuracy better than 0.01 μm). Diamond tools have significant applications in a wide range of fields, including aviation, aerospace, automotive, electronics, and stone materials. Examples include machining composite materials in aerospace, aluminum alloy parts in automotive, and precision parts such as gyroscopes and laser reflectors in instrumentation. However, due to its poor thermal stability, diamond loses hardness at cutting temperatures between 700°C and 800°C. Furthermore, the difference in thermal expansion coefficients between diamond and the tool substrate makes the diamond susceptible to loosening and shedding. Therefore, precision cutting with diamond tools requires precise control of cutting forces. Furthermore, for ultra-precision part machining, changes in cutting temperature directly affect part deformation and surface quality. Therefore, it is very important to accurately detect the cutting temperature and cutting force of diamond tools during the machining process.

[0003] Cutting temperature is usually measured by welding / depositing thin film thermocouples on the tool surface or drilling and embedding thin film thermocouples. For example, the literature "Qiu Wenhao, Lin Qichao, Wang Xiangyu, et al. Research status of thin film thermocouple temperature measurement tools [J]. Tool Technology, 2022(008):056." and the literature "Yu Xiaoyang, Wang Zhenyu, Li Guanghui, et al. Cutting temperature real-time measurement sensor and its characteristics [J]. Journal of Electrode and Control, 2015, 19(4):7." respectively introduce the technology of preparing thin film thermocouple temperature sensors on the tool surface and welding thermocouple temperature sensors for cutting temperature measurement. Thermocouples have the advantages of stable performance, large temperature measurement range and simple structure. However, in order to avoid the structure of the sensor being damaged by cutting fluid, chips, etc. during cutting, the thermocouple temperature sensor needs to be arranged at a certain distance from the actual cutting position. On the one hand, this results in the temperature measured by the sensor not being the actual cutting temperature. On the other hand, attaching a temperature sensor to the tool surface will affect the cutting performance and ease of use of the tool itself. In particular, the method of drilling and embedding a thermocouple temperature sensor will destroy the original strength of the tool and affect its service life.

[0004] Cutting force can be measured by purchasing a commercial cutting force dynamometer or by placing a cutting force measurement chip on the cutting tool. Kistler, a Swiss company, is a global manufacturer of high-end cutting force sensors. The cutting force dynamometers it has developed, such as the 9125A and 9129A, can be used to accurately measure cutting force during rotary and fixed tool cutting processes, respectively. However, the tool needs to be connected to the cutting force dynamometer, which is then installed on the machine tool spindle or tool holder. This measurement method introduces a new module into the original cutting system, which is bound to affect the original assembly accuracy, structural rigidity, and processing performance of the machine tool. It also requires careful installation and debugging, is not convenient, and cannot detect the cutting force at the actual cutting position. Chinese patent CN201610941714.1 invented a composite tool system with two-dimensional ultrasonic vibration and real-time cutting force detection. Cutting force is measured by setting a real-time cutting force detection component on the tool bar. Setting a cutting force measurement component on the tool bar can greatly avoid changes to the machine tool system, but it still cannot measure the cutting force in situ. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a diamond tool with self-sensing cutting force and cutting temperature and a manufacturing method thereof, so as to solve the problem that it is impossible to realize in-situ detection of cutting temperature and cutting heat during precision cutting processing of diamond tools.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A diamond cutting tool with self-sensing cutting force and cutting temperature, comprising a tool bar body, a tool head integrally connected to the front end of the tool bar body, a small tool head embedded in an outer corner of the tool head, the small tool head fixedly mounted on the tool head via a small tool head pressure plate, and a single crystal diamond cutter mounted on the upper end of the outer corner of the small tool head;

[0008] Two heavily doped regions are provided on the upper surface of the single crystal diamond knife, and the two heavily doped regions are commonly connected to a chip temperature sensor sensitive unit;

[0009] Two heavily doped areas are provided on the front arc surface of the single crystal diamond knife, and the two heavily doped areas are commonly connected to a cutting force sensor sensitive unit;

[0010] The cutting force sensor sensitive unit and the chip temperature sensor sensitive unit are both doped with boron;

[0011] The outer surface of each heavily doped region is connected to one end of a metal lead through an ohmic contact region, and the other end of each metal lead is connected to an electrode;

[0012] A sensor signal processing flexible circuit board and an aviation plug are installed at the rear end of the tool bar body; the sensor signal processing flexible circuit board is connected to the signal wire and four electrodes through the sensor power supply, and the aviation plug is connected to the sensor signal processing flexible circuit board.

[0013] A further improvement of the present invention is:

[0014] Preferably, a cutter head assembly mounting groove is provided at an outer top corner of the cutter head, a small cutter head gasket is installed on the cutter head assembly mounting groove, and the small cutter head is installed on the small cutter head gasket.

[0015] Preferably, the front end of the small cutter head pressure plate is provided with a columnar structure, which passes through the through holes on the small cutter head and the small cutter head gasket; the rear end of the small cutter head pressure plate is fixedly mounted on the cutter head by a tool fastening screw.

[0016] Preferably, the two heavily doped regions on the upper surface of the single crystal diamond knife are symmetrical with respect to the central plane of the single crystal diamond knife; and the two heavily doped regions on the front arc surface are both arranged on the central plane.

[0017] Preferably, the electrodes are all arranged on the rear plane of the single crystal diamond knife.

[0018] Preferably, a wire through hole is provided in the small cutter head, a front wire hole is provided in the cutter head, and a rear wire hole is provided in the cutter rod body; the sensor power supply and signal wires pass through the wire through hole, the front wire hole and the rear wire hole in sequence.

[0019] Preferably, the rear end of the shank body is provided with a sensor signal processing component installation slot for installing a sensor signal processing flexible circuit board, and a sensor signal transmission interface component installation slot for installing an aviation plug.

[0020] Preferably, a reserved sensor signal transmission interface assembly installation groove is provided on the knife rod body.

[0021] Preferably, an insulating layer 17 is provided on the outer surface of the single crystal diamond knife 1 .

[0022] A method for preparing the above-mentioned diamond cutting tool with self-sensing cutting force and cutting temperature comprises the following steps:

[0023] Step 1: Form a cutting force sensor sensitive unit 11 and a cutting temperature sensor sensitive unit on a single crystal diamond cutter by ion implantation; fix the single crystal diamond on the cutter head by mechanical reinforcement, powder metallurgy or bonding brazing;

[0024] Step 2: Fix the small cutter head on the cutter head through the small cutter head pressing plate;

[0025] Step 3: The two heavily doped areas on the upper surface of the single crystal diamond knife are connected to the sensitive unit of the cutting temperature sensor, and the two heavily doped areas on the front arc surface of the single crystal diamond knife are connected to the sensitive unit of the cutting force sensor; each heavily doped area is connected to one end of a metal lead through an ohmic contact area, and the other end of the metal lead is connected to an electrode; the electrode is connected to the signal wire and the sensor signal processing flexible circuit board through the sensor power supply.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention discloses a diamond tool with self-sensing cutting force and cutting temperature. The cutting force and cutting temperature sensors are integrated with the tool. A temperature sensor unit is located on the upper surface of the single-crystal diamond tool at the cutting edge, and a cutting force sensor unit is located on the front arc surface at the cutting edge, enabling in-situ measurement of cutting temperature and cutting force during cutting. Both sensor units are doped with boron. Boron-doped diamond semiconductor material has a high piezoresistance coefficient, resulting in a highly sensitive sensor that can accurately measure even minute cutting force and temperature changes during precision and ultraprecision machining. Research has shown that the piezoresistance coefficient of boron-doped diamond material is 600-1000, significantly higher than the piezoresistance coefficient of 80-120 for currently commonly used silicon semiconductor materials. Therefore, the use of diamond semiconductor material significantly improves the sensor's measurement sensitivity and resolution. This structure enables measurement without changing the original tool's shape or structure, offering high practicality and precision.

[0028] Furthermore, the present invention prepares cutting force and cutting temperature sensor sensitive units at the cutting edge position on the single crystal diamond tool through ion implantation to measure the corresponding physical quantities, which not only realizes true in-situ detection, but also does not change the original structure of the tool and does not affect the strength and cutting performance of the tool itself; the cutting tool itself is a sensor, which is different from the existing practice of grooving the tool and embedding the measurement sensor.

[0029] Furthermore, the small cutter head is mounted on the cutter head through a small cutter head gasket, and the small cutter head gasket plays a supporting role for the small cutter head.

[0030] Furthermore, a columnar structure is provided at the front end of the small blade head pressure plate, and the small blade head and the small blade head gasket are stably fixed on the blade head through the columnar structure, so that the blade head is not easy to move during the cutting process and has good stability.

[0031] Furthermore, the temperature measuring sensor sensitive unit itself is located on the cutting edge and is symmetrical with respect to the center plane of the single crystal diamond knife, so that the chip temperature sensor sensitive unit can directly measure the temperature change at the cutting position, and the measured temperature is uniform and representative. The sensitive unit for measuring the cutting force is set at the intersection of the front end of the single crystal diamond knife cutting edge and its center plane. Because this position is the place where the force is most concentrated during the cutting process of the single crystal diamond knife, setting the cutting force sensor sensitive unit here can accurately reflect the real-time changes in the cutting force during the cutting process.

[0032] Furthermore, the electrode is arranged on the rear plane of the single crystal diamond cutter, which facilitates the connection between the electrode and the wire coming out of the cutter head.

[0033] Furthermore, corresponding through holes are provided in the small cutter head, the cutter head and the cutter rod body for placing wires for providing power to the sensor and transmitting signals.

[0034] Furthermore, a corresponding circuit device is placed at the rear end of the tool bar body for collecting, processing and transmitting the cutting temperature and cutting force signals detected by the sensor.

[0035] Furthermore, an insulating layer is provided on the outer surface of the single crystal diamond tool to provide insulation protection for the above structure and prevent the sensor from being corroded, damaged, or short-circuited due to cutting fluid, chips, and dust. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the overall structure of the tool;

[0037] Figure 2 Schematic diagram of the structure of a single-crystal diamond knife; (a) is a schematic diagram of the front structure without an insulating layer, (b) is a schematic diagram of the front structure covered with an insulating layer, (c) is an enlarged schematic diagram of the local structure of the front end of the diamond knife, and (d) is a schematic diagram of the back structure without an insulating layer;

[0038] Figure 3 Schematic diagram of obtaining a sensor sensitive unit by doping single crystal diamond with boron ions;

[0039] Figure 4 The structural diagram and assembly relationship of the small cutter head and the small cutter head gasket

[0040] Figure 5 Schematic diagram of the tool bar structure;

[0041] Figure 6 Schematic diagram of the structure of signal processing components, signal transmission and interface components, and reserved interface components;

[0042] Figure 7 Schematic diagram of the single crystal diamond knife preparation process flow.

[0043] Among them, 1-single crystal diamond knife; 2-small knife head; 3-small knife head gasket; 4-small knife head pressure plate; 5-tool fastening screw; 6-tool bar; 7-signal processing component; 8-signal transmission and interface component; 9-reserved interface component; 11-cutting force sensor sensitive unit; 12-cutting temperature sensor sensitive unit; 13-heavily doped region; 14-ohmic contact region; 15-metal lead; 16-electrode; 17-insulating layer; 110-upper surface; 111-front arc surface; 113-back plane; 114-side surface; 21-wire hole entrance; 22-wire hole exit; 23 - Middle through hole; 24 - Wire through hole; 41 - Columnar structure; 42 - Screw fixing hole; 61 - Tool bar body; 62 - Tool head assembly mounting slot; 63 - Front wire hole; 64 - Rear wire hole; 65 - Sensor signal processing assembly mounting slot; 66 - Sensor signal transmission interface assembly mounting slot; 67 - Reserved interface assembly mounting slot; 68 - Tool head; 71 - Sensor signal processing flexible circuit board; 72 - Sealing gasket; 73 - Sealing cover plate; 83 - Aviation plug; 84 - Sealing gasket; 85 - First screw; 91 - Sealing gasket; 92 - Sealing plate; 93 - Second screw DETAILED DESCRIPTION

[0044] The present invention is described in further detail below with reference to the accompanying drawings:

[0045] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise expressly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The present invention discloses a diamond tool with self-sensing cutting force and cutting temperature, which mainly includes: a single crystal diamond tool 1, a small tool head 2, a small tool head gasket 3, a small tool head pressure plate 4, a tool fastening screw 5, a tool rod 6, a signal processing component 7, a signal transmission and interface component 8, and a reserved interface component 9. Figure 1 shown.

[0047] See also Figure 1 、 Figure 4 and Figure 5 The tool rod 6 is the main structure, which is a rectangular structure; the front end is provided with a single crystal diamond knife 1, a small tool head 2, a small tool head gasket 3, a small tool head pressure plate 4 and a tool fastening screw 5, and the signal processing component 7, the signal transmission and interface component 8, and the reserved interface component 9 are all installed at the rear end of the tool rod.

[0048] The front end of the tool bar 6 is a cutting head 68, which is integrally connected to the tool bar 6 and protrudes relative to the shape of the tool bar 6. A notch is provided at one of the outer corners of the cutting head 68, which serves as a cutting head assembly mounting slot 62. A small cutting head gasket 3 is fixedly placed on the cutting head assembly mounting slot 62, and a small cutting head 2 is fixedly mounted on the small cutting head gasket 3. A single crystal diamond knife 1 is mounted on the outer corner of the small cutting head 2. A small cutting head pressure plate 4 is mounted on the cutting head 68. The small cutting head pressure plate 4 is fixedly connected to the cutting head 68 by a tool fastening screw 5. A columnar structure 41 is provided at the front end of the small cutting head pressure plate 4. This columnar structure 41 is inserted into the middle through hole 23 of the small cutting head 2, fixing the small cutting head 2 and the small cutting head gasket 3 together within the cutting head assembly mounting slot 62.

[0049] See also Figure 2 The shape of the single crystal diamond knife 1 can be adjusted according to actual conditions. In this embodiment, a triangular shape is taken as an example, specifically including an upper surface 110 and a lower surface 112 of the same shape, and the upper surface 110 and the lower surface 112 are connected by a front arc surface 111, a rear plane 113 and two side surfaces 114; the arc length of the front arc surface 111 is less than the length of the rear plane 113, the front arc surface 111 is in front of the rear plane 113, and the two sides of the front arc surface 111 and the two sides of the rear plane 113 are respectively connected by two side surfaces 114; the front arc surface 111, the side surfaces 114, the rear plane 113 and the side surfaces 114 constitute a closed side wall surface. The center plane of the single crystal diamond knife 1 is set as a plane perpendicular to the upper surface 110 and the lower surface 112. The upper surface 110, the lower surface 112 and the front arc surface 111 are all symmetrical structures, symmetrical relative to the center plane of the single crystal diamond knife 1, and the two side surfaces 114 are symmetrical relative to the center plane; parallel metal leads 15 are provided on both sides of the center plane of the upper surface 110, and the two parallel metal leads 15 are parallel to the center plane; four electrodes 16 are provided on the rear plane 113, and two parallel metal leads 15 extend to the rear plane and are connected to two of the electrodes 16 therein, and a heavily doped region 13 is provided at the front end of each metal lead 15, and an ohmic contact region 14 is provided on each heavily doped region 13, and a cutting temperature sensor sensitive unit 12 is provided between the two heavily doped regions 13, and each ohmic contact region 14 is connected to a metal lead 15.

[0050] Two metal leads 15 are mounted on both the front arc surface 111 and a side surface 114. Specifically, the two metal leads 15 are arranged along the entire side surface of the single-crystal diamond blade 1. A heavily doped region 13 is provided at the front end of each metal lead 15, and an ohmic contact region 14 is provided on each heavily doped region 13. A cutting force sensor sensitive unit 11 is located between the two heavily doped regions 13. The rear end of each metal lead 15 extends to the rear plane 113 and is connected to an electrode 16. The two heavily doped regions 13 are arranged on the center plane.

[0051] For details, see Figure 2 It can be seen that the cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12 are both straight and perpendicular to each other; the specific contact resistance of the ohmic contact area 14 is less than or equal to 5×10 -6 Ω·cm 2 .

[0052] For details, see Figure 3 The cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12 are also part of the single crystal diamond knife. Boron elements of a certain concentration and depth are doped at specific positions on the surface of the single crystal diamond knife 1 by ion implantation or in-situ doping. The single crystal diamond doped with boron elements becomes the cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12. Figure 3 As shown; it should be noted that, on the one hand, the specific doping positions selected in this embodiment are respectively located in the long strip areas on the upper surface and side of the front end of the diamond knife, because these two places are the best positions for measuring cutting temperature and cutting force. After boron doping is completed, the single crystal diamond located in this shape area and doping depth becomes the cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12; on the other hand, according to the cutting purpose and actual working conditions of the diamond knife 1 itself, the shape and structural size of the cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12 can also be changed. In addition to the long strip shape of this embodiment, it can also be circular, ring-shaped, etc.

[0053] On the one hand, the diamond knife acts as a cutting tool to cut the material being processed, removing excess material from the part. On the other hand, the cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12 located at the front end of the diamond knife respectively sense the cutting force and cutting temperature during the diamond knife cutting process. In addition, the heavily doped region 13 and the ohmic contact region 14 located on the diamond knife serve as low-resistance conductive regions, used to connect the cutting force sensor sensitive unit 11 to the metal lead 15, and the cutting temperature sensor sensitive unit 12 to the metal lead 15. The heavily doped region 13 and the ohmic contact region 14 are provided to better form a low-resistance electrical connection between the metal lead 15 and the sensor sensitive element on the diamond. The heavily doped region 13 and the metal lead 15 are connected by the ohmic contact region 14. Each metal lead 15 is provided at the end with an electrode 16 for connecting to the sensor wire. The electrode 16 is made of the same material and manufactured using the same method as the metal lead 15, differing only in shape.

[0054] Furthermore, the entire single-crystal diamond knife 1 is wrapped by an insulating layer 7, which also covers the ohmic contact area 14, the metal lead 15 and the electrode 16. The insulating layer 7 provides insulation protection for the entire single-crystal diamond knife 1 to prevent the sensor from being corroded, damaged and short-circuited due to cutting fluid, chips and dust.

[0055] See also Figure 4 、 Figure 5 and Figure 6 The small cutter head 2 mainly includes: a wire hole entrance 21, a wire hole exit 22, and a middle through hole 23. Among them, the wire hole entrance 21 and the wire hole exit 22 are respectively located on the upper surface of the front end and the side of the rear end of the small cutter head 2. The size and shape of the wire holes can be adjusted according to the processing difficulty and actual needs; the middle through hole 23 is located in the middle of the small cutter head 2. The small cutter head serves as a mounting and fixing carrier for the diamond cutter; one end of the sensor power supply and signal wire 81 is connected to the metal electrode located on the surface of the diamond cutter, and then the other end passes through the wire hole entrance 21, the wire through hole 24 and the wire hole exit 22 in sequence, enters the front wire hole 63 and the rear wire hole 64 on the tool rod 6, and finally connects to the sensor signal processing circuit board 71, the wire through hole, the wire hole entrance 21 and the wire hole exit 22. The middle through hole 23 in the middle of the small cutter head 2 is mainly used to install the small cutter head 2. One end of the small cutter head pressure plate 4 extends into the through hole to fix the small cutter head 2 on the small cutter head gasket 3.

[0056] The small cutter head gasket 3 is an independent component that supports the small cutter head 2. It has a through hole with a countersunk groove in the middle. The shape and size of the small cutter head gasket 3 match those of the small cutter head 2. The specific structural parameters can be determined according to actual conditions. The through hole in the middle of the small cutter head gasket 3 is connected to the middle through hole 23. The downward-extending columnar structure 41 of the small cutter head pressure plate 4 is inserted into the middle through hole 23 and the through hole of the small cutter head gasket 3 in sequence, and the columnar structure 41 fixes the small cutter head 2 and the small cutter head gasket 3. The small cutter head gasket 3 is placed below the small cutter head 2. As a support for the small cutter head, this gasket has the following functions: 1. It can absorb the impact energy caused by cutting or damage to the tool; 2. It can prevent damage to the tool bar when the tool hits the tool and chips impact the tool, effectively extending the service life of the tool bar; 3. The gasket is easy to mass-produce and can easily ensure the positioning accuracy of the cutter head above it, facilitating interchangeability; 4. It facilitates the standardization of the tool groove and facilitates manufacturing.

[0057] See also Figure 1 The small cutter head pressing plate 4 is an independent part with a columnar structure 41 at its front end and a screw fixing hole 42 at the middle rear position. The columnar structure 41 is connected to the lower surface of the front end of the main structure of the small cutter head pressing plate 4. The columnar structure 41 is inserted into the middle through hole 23 and the through hole of the small cutter head gasket 3. The diameter of the columnar structure 41 is slightly smaller than the diameter of the middle through hole 23. Then the tool fastening screw 5 is screwed into the screw fixing hole 42, so that the small cutter head pressing plate 4 is fixed on 68, and the small cutter head 2 is tightly fixed to the small cutter head gasket 3 by the columnar structure 41. Under the action of the tool fastening screw 5, the small cutter head pressing plate 4 fixes the small cutter head 2 connected to the single crystal diamond cutter 1 and the small cutter head gasket 3 in the cutter head assembly mounting groove 62 on the tool arbor.

[0058] See also Figure 1 The tool fastening screw 5 is an independent part. It is used to fasten the small cutter head pressing plate 4. It passes through the screw fixing hole 42 in the small cutter head pressing plate 4 and connects to the cutter head 68, so that the small cutter head 2 connected to the single crystal diamond cutter 1 and the small cutter head gasket 3 are fixed in the cutter head assembly mounting groove 62 on the tool arbor.

[0059] See also Figure 5The tool bar 6 mainly includes: a tool bar body 61, a tool head assembly mounting slot 62, a front wire hole 63, a rear wire hole 64, a sensor signal processing assembly mounting slot 65, a sensor signal transmission interface assembly mounting slot 66, a reserved interface assembly mounting slot 67, and a tool head 68. Among them, the main structure is an integrally connected tool head 68 and tool bar body 61. The tool head 68 is integrally connected to the front end surface of the tool bar body 61. The shape of the tool head 68 is different from that of the tool bar body 61 and can be adjusted according to the situation. The front end wire hole 63, the rear end wire hole 64, the sensor signal processing component installation slot 65, the sensor signal transmission interface component installation slot 66, and the reserved interface component installation slot 67 are all processed on the tool rod body 61 and the tool head 68; the front end wire hole 63 is opened in the tool head 68, and the rear end wire hole 64 is opened in the tool rod body 61, one end of the front end wire hole 63 is close to the wire hole outlet 22 on the small tool head 2, and the other end is connected to the rear end wire hole 64; the rear end wire hole 64 is respectively connected to the sensor signal processing component installation slot 65, the sensor signal transmission interface component installation slot 66, and the reserved interface component installation slot 67, the sensor signal processing component installation slot 65 and the sensor signal transmission interface component installation slot 66 are respectively opened on the side of the tool rod body 61, and the reserved interface component installation slot 67 is opened on the rear end surface of the tool rod body 61, the sensor signal processing component installation slot 65, the sensor signal transmission interface component installation slot 66 and the reserved interface component installation slot 67 are connected.

[0060] The tool rod 6 in this embodiment, in addition to being used to install the small tool head and the small tool head gasket connected to the single crystal diamond tool, can also provide a through hole and protection for the layout of the sensor power supply and signal wires. In addition, it has a shielding function for external electromagnetic signals, improves the signal-to-noise ratio and anti-interference ability of the sensor, and provides an installation slot for installing sensor signal processing components and sensor signal transmission and interface components.

[0061] The signal processing assembly 7 mainly includes: a sensor signal processing flexible circuit board 71, a sealing gasket 72, and a sealing cover plate 73. The sensor signal processing flexible circuit board 71 is installed in the sensor signal processing assembly mounting groove 65. The sensor signal processing flexible circuit board 71 is connected to the sensor power supply and signal wire 81. The sensor power supply and signal wire 81 are arranged in the connected front wire hole 63 and rear wire hole 64. The front end of the sensor power supply and signal wire 81 is connected to the four metal electrodes 16, and the rear end is connected to the sensor signal processing flexible circuit board 71. A sealing cover plate 73 is installed above the sensor signal processing flexible circuit board 71. The sealing cover plate 73 is snap-fitted to the sensor signal processing assembly mounting groove 65. A sealing gasket 72 is installed between the sealing cover plate 73 and the sensor signal processing assembly mounting groove 65 to provide waterproof and dustproof functions.

[0062] The working process of the signal processing component 7 is: converting the physical signals sensed by the cutting force sensor sensitive unit 11 and the cutting temperature sensor sensitive unit 12 into voltage changes that can be recognized by external devices, and further converting the voltage changes into digital signals that can be collected and stored by external devices.

[0063] The signal transmission and interface component 8 mainly includes: a sensor power supply and signal wire 81, an aviation plug 83, a sealing gasket 84, and a first screw 85; the sensor signal processed by the sensor signal processing flexible circuit board 71 is connected to the aviation plug 83 through a wire, and the aviation plug 83 is installed in the sensor signal transmission interface component mounting groove 66 through four first screws 85. A sealing gasket 84 is arranged between the aviation plug 83 and the sensor signal transmission interface component mounting groove 66.

[0064] The working process of the signal transmission and interface component is: connected to the signal processing component, and the sensor signal is transmitted to the external device through a standard interface such as an aviation plug. In addition, the interface can be changed to a digital data connector, such as a USB interface, type-C, network cable interface, etc.

[0065] The reserved interface assembly 9 mainly includes: a sealing gasket 91, a sealing plate 92, and a second screw 93; the reserved interface assembly mainly serves as a backup for the signal transmission and interface assembly 8; the sealing plate 92 is installed in the reserved interface assembly installation groove 67 by four second screws 93, and a sealing gasket 91 is provided between the sealing plate 92 and the reserved interface assembly installation groove 67. When the interface assembly is not needed, the reserved signal transmission and interface assembly installation groove is sealed by the sealing gasket 91, the sealing plate 92, and the second screw 93. If the sensor signal transmission and interface assembly is installed on the side of the tool bar in this embodiment, which will hinder the installation and use of the tool, the reserved interface can be enabled and the sensor signal transmission and interface assembly can be installed here.

[0066] Regarding the above-mentioned diamond cutting tool with self-sensing cutting force and cutting temperature, the manufacturing method of each structural component unit is as follows:

[0067] Specifically, for single crystal diamond knives:

[0068] The overall processing flow of single crystal diamond cutters includes: single crystal diamond processing → cutting force and cutting temperature sensor sensitive unit processing → heavily doped area processing → ohmic contact area processing → metal lead and electrode processing → insulation layer processing. The specific processing methods for each step are as follows:

[0069] (1) Single crystal diamond: Natural single crystal diamond or artificial synthetic diamond can be selected and processed into the shape required by the single crystal diamond knife through mechanical grinding and laser cutting.

[0070] (2) Cutting force sensor and cutting temperature sensor sensitive unit: The sensor sensitive unit is prepared by ion implantation. First, a mask is prepared at the position on the surface of the single crystal diamond where the sensor sensitive unit is not required. The function of the mask is to block the "boron" ions from entering the single crystal diamond. The mask can be made of metals such as Au, Ni, Ti, etc., or non-metallic materials such as photoresist. Its fabrication method can adopt the photolithography, sputtering, and stripping methods in micro-electromechanical system technology, which will not be described in detail. The shape of the mask is determined by the shape of the sensor sensitive unit to be processed. Then, the "boron" ions are accelerated by ion implantation and injected into the single crystal diamond material not covered by the mask. The single crystal diamond doped with the "boron" element is transformed from the original insulating material into a conductor material with a piezoresistive effect and serves as the cutting force and cutting temperature sensor sensitive unit. After the "boron" ions are injected into the single crystal diamond, their movement speed gradually decreases until they stop. The distance from the incident surface to the stopping position of the "boron" ions is the doping depth of the "boron" ions. By adjusting the energy and dose of ion implantation, the depth of ion implantation and the concentration of ions in the single-crystal diamond can be effectively controlled, thereby controlling the thickness and piezoresistance coefficient of the sensor's sensitive unit. The piezoresistance coefficient is an indicator of the strength of the piezoresistive effect of a semiconductor material. A high piezoresistive coefficient indicates a strong piezoresistive effect and a high sensitivity of the sensor fabricated.

[0071] Generally, a light or medium implantation concentration will result in a sensor sensitive unit with a higher piezoresistive coefficient. In this embodiment, the ion implantation energy and implantation dose for reference are 100 keV and 10 15 cm -2 .

[0072] (3) Heavily doped region: The heavily doped region is also prepared by ion implantation. The ion implantation dose is larger, which makes the concentration of doped "boron" ions very high. The conductivity of the single crystal diamond in the heavily doped region is closer to that of a metal conductor. The actual function of the heavily doped region is to help form a low-resistance ohmic contact between the metal material and the semiconductor material doped with boron ions. After the completion of the "boron" ion heavy doping, high-temperature annealing is required to drive the doped ions into the interior of the single crystal diamond and activate them, so as to exert a stable semiconductor piezoresistive effect.

[0073] (4) Ohmic contact area: One or more layers of metal material are made on the heavily doped area of the single crystal diamond material, such as the "Ti-Pt-Au" three-layer metal in this embodiment. Among them, titanium (Ti) is used as the contact layer metal, and reacts with the carbon in the diamond to generate a conductive alloy material (such as TiC) with a very low resistance value. This alloy material is the ohmic contact; platinum acts as a barrier layer, which can not only prevent the top layer of gold from diffusing into the titanium and diamond in the lower layer, but also prevent titanium from diffusing into the gold during alloying, thereby preventing titanium from diffusing into the gold and causing the resistance of the gold to increase. Then, a high-temperature rapid annealing method is used to react between the heavily doped diamond and the metal Ti to generate a "semiconductor-metal" alloy material, that is, an ohmic contact. The ohmic contact should have a low contact resistivity, so that the contact resistance between the sensor sensitive unit and the metal lead is low.

[0074] (4) Metal leads and electrodes: Use photolithography, sputtering, stripping and other process methods in MEMS technology to make one or more layers of metal leads and connect them to the gold layer above the ohmic contact.

[0075] (5) Insulation layer: In order to protect the ohmic contact area, metal leads and electrodes from the influence and damage of chips, dust and cutting fluid, and to ensure the insulation of the metal leads of the sensor from the outside world, an insulation layer is made on the non-cutting edge area of the single crystal diamond knife using sputtering, evaporation and other methods in micro-electromechanical system technology. The insulation layer can be made of silicon oxide, silicon nitride, aluminum oxide and other materials.

[0076] Specifically, for the small knife head 2

[0077] The small blade head adopts the existing metal powder sintering technology, which first presses the metal powder into shape and then sinteres and solidifies it at high temperature.

[0078] Specifically, for the small blade head gasket 3

[0079] The small cutter head gasket is machined by using metal cutting process.

[0080] Specifically, for the small blade pressure plate

[0081] The small cutter head pressure plate is machined by adopting metal cutting processing technology.

[0082] Specifically, for tool fastening screws

[0083] The tool fastening screw is machined using a metal cutting process.

[0084] Specifically, for the tool bar

[0085] The tool bar is processed by metal cutting technology combined with corresponding heat treatment technology.

[0086] Specifically, for signal processing components

[0087] The flexible circuit board of the sensor signal processing circuit in the signal processing component is manufactured using a flexible printed circuit board (FPC) manufacturing process, the sealing gasket is purchased according to the corresponding size, and the sealing cover is obtained by machining.

[0088] Specifically, for signal transmission and interface components

[0089] The signal transmission and interface components, including the sensor power supply and signal wires, aviation plugs, gaskets, and screws, are assembled from purchased pre-assembled parts. It should be noted that soldering connects the sensor power supply and signal wires to the electrodes on the single-crystal diamond blade, the sensor power supply and signal wires to the signal processing component, and the signal transmission and interface component. Insulating sealant is applied to the solder joints, electrodes, and exposed metal on the wires.

[0090] Specifically, for the reserved interface components

[0091] The sealing gaskets and screws in the reserved interface components are purchased finished parts, and the sealing plates are machined.

[0092] Assembly method of the diamond tool with self-sensing cutting force and cutting temperature

[0093] (1) The single crystal diamond knife 1 is fixed to the small knife head 2 by a mechanical reinforcement method (grinding the bottom surface of the single crystal diamond knife and the pressure surface on the small knife head, and fixing it to the small knife head by pressing with a pressure plate) or a powder metallurgy method (placing the single crystal diamond knife in alloy powder, sintering it in a vacuum under pressure, and fixing the single crystal diamond knife to the small knife head) or a bonding and brazing method (using an inorganic adhesive or other adhesive to fix the single crystal diamond knife).

[0094] (2) The small cutter head gasket 3 is fixed in the cutter head assembly mounting groove at the front end of the cutter bar by screws.

[0095] (3) The small cutter head is fixed above the small cutter head gasket and in the cutter head assembly mounting groove through the small cutter head pressure plate and the tool fastening screw.

[0096] (4) The cutting force sensor sensitive unit and the cutting temperature sensitive unit on the single crystal diamond knife are connected to the heavily doped area, ohmic contact, metal lead and electrode in turn. The electrode is connected to the sensor power supply and signal wire through the soldering process. The sensor power supply and signal wire pass through the wire hole on the small knife head in turn and are connected to the knife sensor signal processing circuit through the soldering process. The signal from the sensor signal processing circuit is connected to the aviation plug in the sensor signal transmission and interface assembly through the wire and soldering process. The sensor signal processing flexible circuit board is installed in the corresponding installation groove and is sealed and protected by a sealing gasket and a sealing plate. The aviation plug and the sealing gasket are fixed in the corresponding installation groove by screws. The reserved interface is sealed by a sealing gasket, a sealing plate and screws when it is not needed.

[0097] The working principle of the above-mentioned diamond tool with self-sensing cutting force and cutting temperature

[0098] (1) Cutting force perception principle

[0099] During the cutting process, the cutting force sensor sensitive unit located on the front side of the single crystal diamond tool is subjected to compressive stress under the action of the cutting force. Under the action of the piezoresistive effect of the semiconductor material, the resistance value of the sensitive unit material changes. The change law follows the following formula:

[0100]

[0101] Where, ΔR, R, π l and π t , σ l and σ t where represents the change in resistance of the sensitive unit, the initial resistance of the sensitive unit, the longitudinal and transverse piezoresistance coefficients of the doped single-crystal diamond material, and the transverse and longitudinal stresses applied to the sensitive unit, respectively. As can be seen from the above formulas, the change in resistance of the sensitive unit corresponds to the change in stress, and the stress value corresponds one-to-one with the magnitude of the cutting force. Therefore, measuring the change in resistance of the sensitive unit can reflect changes in cutting force. This change in resistance is further converted into a voltage signal by a cutting force signal processing circuit, which is then collected, stored, and displayed. Because the sensor unit used for cutting force measurement is itself part of the single-crystal diamond tool and participates in material cutting, in-situ, self-detection of cutting force is achieved. The tool itself directly senses the cutting force, eliminating the need for multi-stage transmission and resulting in no loss of cutting force, greatly improving measurement accuracy, reliability, and real-time performance.

[0102] (2) Cutting temperature sensing principle

[0103] During the cutting process, the cutting temperature sensor's sensitive element, located on the front upper surface of the single-crystal diamond cutter, directly senses the changes in cutting temperature caused by the cutting heat. This temperature change causes changes in the carrier concentration within the sensitive element, resulting in a change in the resistivity of the sensitive element, which ultimately manifests as a change in the sensitive element's resistance value. The cutting temperature and the resistance value of the sensitive element have a one-to-one correspondence, and measuring the resistance value of the sensitive element can reflect the cutting temperature. The cutting temperature signal processing circuit further converts this resistance change into a voltage signal, which is then collected, stored, and displayed.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A diamond tool with self-sensing cutting force and cutting temperature, characterized in that: The present invention comprises a tool rod body (61), the front end of the tool rod body (61) is integrally connected with a tool head (68), a small tool head (2) is embedded at an outer corner of the tool head (68), the small tool head (2) is fixedly mounted on the tool head (68) via a small tool head pressing plate (4), and a single crystal diamond knife (1) is mounted on the upper end of the outer corner of the small tool head (2); Two heavily doped regions (13) are provided on the upper surface (110) of the single crystal diamond knife (1), and the two heavily doped regions (13) are commonly connected to a cutting temperature sensor sensitive unit (12); Two heavily doped regions (13) are provided on the front arc surface (111) of the single crystal diamond knife (1), and the two heavily doped regions (13) are commonly connected to a cutting force sensor sensitive unit (11); The cutting force sensor sensitive unit (11) and the chip temperature sensor sensitive unit (12) are both doped with boron; The outer surface of each heavily doped region (13) is connected to one end of a metal lead (15) via an ohmic contact region (14), and the other end of each metal lead (15) is connected to an electrode (16); A sensor signal processing flexible circuit board (71) and an aviation plug (83) are installed at the rear end of the knife bar body (61); the sensor signal processing flexible circuit board (71) is connected to the signal wire (81) and the four electrodes (16) through a sensor power supply, and the aviation plug (83) is connected to the sensor signal processing flexible circuit board (71).

2. A diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: A cutter head assembly mounting groove (62) is provided at an outer top corner of the cutter head (68), a small cutter head gasket (3) is mounted on the cutter head assembly mounting groove (62), and the small cutter head (2) is mounted on the small cutter head gasket (3).

3. A diamond tool with self-sensing cutting force and cutting temperature according to claim 2, characterized in that: The front end of the small cutter head pressure plate (4) is provided with a columnar structure (41), and the columnar structure (41) passes through the through holes on the small cutter head (2) and the small cutter head gasket (3); the rear end of the small cutter head pressure plate (4) is fixedly mounted on the cutter head (68) via a tool fastening screw (5).

4. A diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The two heavily doped regions (13) on the upper surface of the single crystal diamond knife (1) are symmetrical with respect to the central plane of the single crystal diamond knife (1); and the two heavily doped regions (13) on the front arc surface (111) are both arranged on the central plane.

5. The diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The electrodes (16) are all arranged on the rear plane (113) of the single crystal diamond knife (1).

6. The diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The small cutter head (2) is provided with a wire through hole (24), the cutter head (68) is provided with a front wire hole (63), and the cutter rod body (61) is provided with a rear wire hole (64); the sensor power supply and the signal wire (81) pass through the wire through hole (24), the front wire hole (63) and the rear wire hole (64) in sequence.

7. The diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The rear end of the knife bar body (61) is provided with a sensor signal processing component installation slot (65) for installing a sensor signal processing flexible circuit board (71), and a sensor signal transmission interface component installation slot (66) for installing an aviation plug (83).

8. The diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The knife bar body (61) is provided with a reserved sensor signal transmission interface component installation groove (67).

9. The diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The outer surface of the single crystal diamond knife (1) is provided with an insulating layer (17).

10. A method for preparing a diamond tool with self-sensing cutting force and cutting temperature according to claim 1, characterized in that: The following steps are involved: Step 1: forming a cutting force sensor sensitive unit (11) and a cutting temperature sensor sensitive unit (12) on a single crystal diamond knife (1) by ion implantation; fixing the single crystal diamond (1) on a small knife head (2) by mechanical reinforcement, powder metallurgy or bonding brazing; Step 2, fixing the small cutting head (2) on the cutting head (68) through the small cutting head pressing plate (4); Step 3: The two heavily doped regions (13) on the upper surface of the single crystal diamond knife (1) are connected to the sensitive unit (12) of the cutting temperature sensor, and the two heavily doped regions (13) on the front arc surface of the single crystal diamond knife (1) are connected to the sensitive unit (11) of the cutting force sensor; each heavily doped region (13) is connected to one end of a metal lead (15) through an ohmic contact region (14), and the other end of the metal lead (15) is connected to an electrode (16); the electrode (16) is connected to the signal wire (81) and the sensor signal processing flexible circuit board (71) through a sensor power supply.

Images