A six-component cutting force and torque dynamometer based on piezoelectric film

Abstract

The present invention relates to the field of intelligent manufacturing technology, and discloses a six-component cutting force and torque dynamometer based on piezoelectric film, comprising a bottom sealing cover and a housing, a dynamometer base and a base mounted above the bottom sealing cover, horizontal pressure blocks higher than the base mounted on four vertical mounting surfaces of the base, the top surfaces of the horizontal pressure blocks supporting and collectively mounting Z-direction pressure blocks, respective PVDF piezoelectric films pre-tightened and mounted between each horizontal pressure block and the vertical mounting surface, and between each horizontal pressure block and the Z-direction pressure block, the output end of each PVDF piezoelectric film being connected to the input channel of a charge amplifier, and the output end of the charge amplifier being connected to an MCU main control chip via an AD converter. The present invention combines a multi-directional pressure block layout with a pre-tightened film decoupling structure to effectively solve the multi-component coupling interference problem of traditional dynamometers, improve dynamic force detection accuracy and response speed, have low manufacturing costs, and are highly convenient to install.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent manufacturing technology, and in particular to the field of cutting force measurement technology, and specifically relates to a six-component cutting force and torque dynamometer based on piezoelectric film. Background Art

[0002] In the field of intelligent manufacturing, especially in the machine tool manufacturing process, cutting force is the main parameter in mechanical processing. Accurate measurement of cutting force is not only the basis for optimizing processing technology and ensuring equipment stability, but also the core requirement for dynamic performance testing of machine tools and load analysis of structural components.

[0003] Among cutting force measurement methods, direct measurement with a dynamometer is often used. Traditional strain gauge dynamometers, due to their slow response speed and narrow frequency response range, struggle to meet the requirements for real-time testing of highly dynamic cutting forces, resulting in significant deviations between the measured cutting forces and the actual cutting forces. While piezoelectric quartz dynamometers offer superior performance, their high cost and complex installation limit their widespread use in industrial testing scenarios.

[0004] In summary, multi-dimensional dynamic force testing devices for machining processes still suffer from insufficient test accuracy, high cost, and complex installation. There is an urgent need for a method that can simultaneously achieve high-precision, low-cost, and easily integrated multi-dimensional force testing. To address these issues, the present invention proposes a six-component cutting force and torque dynamometer based on piezoelectric film. Summary of the Invention

[0005] In order to solve the problems that traditional strain-type cutting force dynamometers cannot meet the requirements of high-precision, high-frequency dynamic cutting force measurement, and that piezoelectric quartz dynamometers are high in cost and complex to install, the present invention provides a six-component cutting force and torque dynamometer based on piezoelectric film.

[0006] The present invention is implemented by the following technologies:

[0007] The present invention provides a six-component cutting force and torque dynamometer based on piezoelectric film, comprising a bottom sealing cover, a dynamometer base installed above the bottom sealing cover, a shell installed above the dynamometer base along the outer edge, the upper surface of the dynamometer base is located in the shell and a base is fixed thereto, the base is provided with four concave rectangular grooves along the side surfaces, the groove sidewalls of each rectangular groove are provided with a vertical mounting surface, horizontal pressing blocks higher than the base are mounted on the four vertical mounting surfaces, the horizontal pressing blocks include X-direction pressing blocks and Y-direction pressing blocks installed alternately, a respective PVDF piezoelectric film is pre-tightenedly mounted between each horizontal pressing block and the vertical mounting surface, the top surface of the horizontal pressing block supports and is jointly provided with a Z-direction pressing block, an upper shell groove for clamping the upper edge of the shell is provided on the outer edge of the lower surface of the Z-direction pressing block, a respective PVDF piezoelectric film is pre-tightenedly mounted between each horizontal pressing block and the Z-direction pressing block, the output end of each PVDF piezoelectric film is connected to the input channel of a charge amplifier, and the output end of the charge amplifier is connected to an MCU main control chip through an AD converter.

[0008] During implementation, it includes a bottom sealing cover, and a dynamometer base is installed above the bottom sealing cover. Specifically, the bottom sealing cover is installed on the dynamometer base through the bottom threaded hole through the bottom connecting screw. A shell is installed along the outer edge above the dynamometer base. A lower shell groove for clamping the lower edge of the shell is opened on the edge of the upper surface of the dynamometer base. A first shell sealing ring is embedded in the lower shell groove. The shell and the bottom sealing cover are used in conjunction with the Z-direction pressure block to seal the entire device, thereby improving the overall waterproof performance, which is especially suitable for cutting processing scenarios with cutting fluid and improving the scope of application. The upper surface of the dynamometer base is located in the shell and a base is fixed thereon. The base is provided with four recessed grooves along the sides. A concave rectangular groove, with longitudinal vertical avoidance grooves at the groove edges, is used to reduce the difficulty of processing and avoid horizontal pressure blocks, reducing the difficulty of assembly. The end of the vertical avoidance groove is connected to the bottom wire collection groove in the center of the dynamometer base. A wire outlet hole connected to the bottom wire collection groove is opened on the side wall of the dynamometer base. The wire outlet hole is connected to the waterproof wire outlet seat arranged on the side of the dynamometer base. A bottom sealing ring is installed between the bottom sealing cover and the dynamometer base on the outside of the bottom wire collection groove, that is, the diameter of the bottom sealing ring is larger than the diameter of the bottom wire collection groove. The bottom sealing ring is installed in the bottom sealing ring groove arranged on the lower surface of the dynamometer base to improve the overall waterproofness.

[0009] Each rectangular groove has a vertical mounting surface on its side wall, and horizontal pressure blocks higher than the base are installed on the four vertical mounting surfaces. The horizontal pressure blocks include X-direction pressure blocks and Y-direction pressure blocks installed alternately. The structures of the X-direction pressure blocks and the Y-direction pressure blocks are exactly the same. Specifically, each vertical mounting surface is provided with two first threaded holes to cooperate with the first bolt to install the X-direction pressure block or the Y-direction pressure block. The X-direction pressure block and the Y-direction pressure block are orthogonally distributed. The vertical mounting surface is provided with a first pin hole between the two first threaded holes to facilitate the positioning of the horizontal pressure block; each horizontal pressure block is pre-tightened and installed with its own PVDF piezoelectric film, that is, a water-soluble film. The horizontal PVDF piezoelectric film is used to detect the X-direction cutting force, the Y-direction cutting force and the Z-direction torque. A horizontal PVDF piezoelectric film receiving groove is provided in the middle of the side of each horizontal pressure block facing the vertical mounting surface. The horizontal PVDF piezoelectric film is pre-tightened and installed in the horizontal PVDF piezoelectric film receiving groove. The groove depth of the horizontal PVDF piezoelectric film receiving groove is less than the thickness of the horizontal PVDF piezoelectric film. The top surface of the horizontal pressure block supports and is equipped with a Z-direction pressure block. The outer edge of the lower surface of the Z-direction pressure block is provided with an upper shell groove for clamping the upper edge of the shell. The second shell sealing ring is embedded in the upper shell groove. The upper and lower edges of the shell are clamped in the lower shell groove and the upper shell respectively. The groove is formed, and the first shell sealing ring and the second shell sealing ring are used to improve the sealing performance, thereby realizing overall sealing; the Z-direction pressure block is installed on the horizontal pressure block by four second bolts installed in the second threaded holes, and the upper surface of the Z-direction pressure block is provided with a workpiece mounting hole and a second pin hole between the second threaded holes, and a positioning groove is provided on the inner edge of the Z-direction pressure block to facilitate center positioning during use. Each horizontal pressure block and the Z-direction pressure block are pre-tightened with their own PVDF piezoelectric film, namely, the Z-direction PVDF piezoelectric film. The four PVDF piezoelectric films are used to detect the Z-direction cutting force, X-direction torque, and Y-direction torque. The upper surface of each horizontal pressure block is provided with a Z-direction PVD The F piezoelectric film receiving groove and the Z-direction PVDF piezoelectric film receiving groove are pre-tightened and installed in the Z-direction PVDF piezoelectric film receiving groove. The groove depth of the Z-direction PVDF piezoelectric film receiving groove is less than the thickness of the Z-direction PVDF piezoelectric film, and the groove depth of the Z-direction PVDF piezoelectric film receiving groove is 0.8~0.9 times the thickness of the Z-direction PVDF piezoelectric film. The external six-component cutting force is accurately measured by the arranged PVDF piezoelectric films. The output end of each PVDF piezoelectric film is connected to the input channel of the charge amplifier to convert the tensile pressure collected by the PVDF piezoelectric film into a voltage signal. The voltage signals converted from the eight PVDF piezoelectric films are recorded as ~ The charge amplifier's output is connected to the MCU via an A / D converter. Based on the tensile and compressive forces measured in three orthogonal directions by the eight PVDF piezoelectric films, the main control chip calculates the six-component cutting force and torque according to the spatial force equilibrium conditions. These are then transmitted via a serial port. In this device, the X-, Y-, and Z-axis pressure blocks are installed in different directions. The PVDF piezoelectric films preloaded in these directions are then used to detect the cutting forces in the corresponding directions, achieving structural decoupling.

[0010] When used, the following steps are included:

[0011] S1. Install the horizontal pressing blocks on the base, with the X-direction pressing blocks and the Y-direction pressing blocks installed alternately so that the upper surface of the horizontal pressing blocks is higher than the upper surface of the base. A PVDF piezoelectric film is pre-tightened between the contact surfaces of the four horizontal pressing blocks and the base.

[0012] S2. Install the first housing sealing ring in the groove of the lower housing, install the housing, connect the Z-direction pressure block to the upper surface of the horizontal pressure block via a second bolt, pre-tighten a PVDF piezoelectric film between the upper surface of each horizontal pressure block and the contact surface of the Z-direction pressure block, and use eight PVDF piezoelectric films to detect the tensile pressure transmitted by the pressure block. Install the second housing sealing ring in the groove of the upper housing, and insert the upper edge of the housing into the groove of the upper housing, and install the Z-direction pressure block;

[0013] S3, pass the lead of PVDF piezoelectric film through the waterproof outlet seat, and connect the output end of each PVDF piezoelectric film to a charge amplifier to convert the pressure signal into a voltage signal. The voltage signals converted from the eight PVDF piezoelectric films are recorded as ~ , characterizes the tensile force between the corresponding contact surfaces, and connects the output end of the charge amplifier to the MCU main control chip through the AD converter;

[0014] S4. Place the bottom sealing ring in the bottom sealing ring groove, screw the bottom connecting screw into the bottom threaded hole, install the bottom sealing cover on the dynamometer base and fix it on the machine tool workbench, install the workpiece on the Z-axis pressure block, start the machine tool to start cutting, and the cutting force generated by the tool cutting the workpiece is transmitted to the Z-axis pressure block, and the Z-axis pressure block is transmitted to the X-axis pressure block and the Y-axis pressure block; the tensile and pressure collected by the PVDF piezoelectric film is converted into a voltage signal through the charge amplifier, and the voltage signal is collected by the AD converter and digitally transmitted to the MCU main control chip, and the voltage signal processing and calculation are completed in the main control chip to obtain the six-component cutting force and torque, which are transmitted to the outside through the serial port.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The present application provides a six-component cutting force and torque dynamometer based on piezoelectric film, which adopts PVDF piezoelectric film as the core sensing element, and utilizes its good piezoelectric effect and high natural frequency to detect the three-dimensional cutting force and torque generated during the cutting process. It has the advantages of good dynamic characteristics, wide frequency response range, high sensitivity, high flexibility, and low cost. It also combines the multi-directional pressure block layout and the pre-tightened film decoupling structure to effectively solve the multi-component coupling interference problem of traditional dynamometers.

[0017] By optimizing the device configuration and spatial force balance algorithm, this application can simultaneously and accurately measure the six-component cutting force and its torque or three-dimensional cutting force, greatly improving the dynamic force detection accuracy and response speed; on the other hand, it simplifies the system architecture and calibration process, significantly reduces manufacturing costs, and enhances installation convenience.

[0018] This application can be widely used in high-precision cutting force measurement, and is widely used in CNC machine tools, machining process monitoring, robot control and automated manufacturing and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 It is an exploded schematic diagram of the present invention.

[0021] Figure 3 It is a schematic diagram of the installation position of the housing 11 in the present invention.

[0022] Figure 4 It is a schematic structural diagram of the Z-direction pressing block 1 in the present invention.

[0023] Figure 5 It is a schematic structural diagram of the Z-direction pressing block 1 in the present invention from another angle.

[0024] Figure 6 It is a structural diagram of the dynamometer base 6 and the base 4 in the present invention.

[0025] Figure 7 It is a structural diagram of the dynamometer base 6 and the base 4 from another angle in the present invention.

[0026] Figure 8 It is a schematic diagram of the installation position of the PVDF piezoelectric film 7 in the present invention.

[0027] Figure 9 It is a schematic diagram of the layout of the spatial force system composed of the positive tensile pressure measured by the PVDF piezoelectric film 7.

[0028] Figure 10 It is a schematic structural diagram of the X-direction pressing block 2 or the Y-direction pressing block 3 in the present invention.

[0029] Figure 11 It is a structural block diagram of the data acquisition and transmission system of the present invention.

[0030] In the picture:

[0031] 1-Z-direction pressing block, 101-positioning slot, 102-second threaded hole, 103-workpiece mounting hole, 104-second pin hole, 105-upper housing slot;

[0032] 2-X-direction pressing block, 201-first X-direction pressing block, 202-second X-direction pressing block;

[0033] 3-Y-direction pressing block, 301-first Y-direction pressing block, 302-second Y-direction pressing block, 303-Z-direction PVDF piezoelectric film containing groove, 304-horizontal PVDF piezoelectric film containing groove, 305-via hole, 306-through hole;

[0034] 4-base, 401-vertical avoidance groove, 402-vertical mounting surface, 403-first threaded hole, 404-first pin hole, 405-lower shell groove;

[0035] 5-first bolt;

[0036] 6-Dynamometer base, 601-wire outlet hole, 602-bottom wire collection slot, 603-bottom threaded hole, 604-bottom sealing ring groove;

[0037] 7-PVDF piezoelectric film, 701-first Z-direction PVDF piezoelectric film, 702-second Z-direction PVDF piezoelectric film, 703-third Z-direction PVDF piezoelectric film, 704-fourth Z-direction PVDF piezoelectric film, 705-second X-direction PVDF piezoelectric film, 706-first Y-direction PVDF piezoelectric film, 707-first X-direction PVDF piezoelectric film, 708-second Y-direction PVDF piezoelectric film;

[0038] 8- second bolt;

[0039] 9- bottom sealing cover;

[0040] 10-first housing sealing ring;

[0041] 11-housing;

[0042] 12-Second housing sealing ring;

[0043] 13- waterproof outlet seat;

[0044] 14- bottom sealing ring;

[0045] 15-Bottom connecting screws. DETAILED DESCRIPTION

[0046] The specific embodiments of the present invention are described in detail below.

[0047] A six-component cutting force and torque dynamometer based on piezoelectric film is used to measure the dynamic cutting force in high-speed cutting. Figures 1-3 As shown: it includes a bottom sealing cover 9, and a dynamometer base 6 is installed above the bottom sealing cover 9. Specifically, the bottom sealing cover 9 is installed on the dynamometer base 6 by passing the bottom connecting screw 15 through the bottom threaded hole 603. A shell 11 is installed along the outer edge of the dynamometer base 6. The upper surface edge of the dynamometer base 6 is provided with a lower shell groove 405 for clamping the lower edge of the shell 11. The lower shell groove 405 is embedded with a first shell sealing ring 10. The shell 11 and the bottom sealing cover 9 are used to cooperate with the Z-direction pressure block 1 to seal the entire device, thereby improving the overall waterproof performance, which is particularly suitable for cutting processing scenarios with cutting fluid and improving the scope of application. In this embodiment, the bottom sealing cover 9 and the shell 11 are both made of stainless steel, which not only increases the anti-corrosion performance and improves the life of the device, but also uses metal materials to increase the electromagnetic shielding performance, which is beneficial to signal stability.

[0048] like Figure 6 As shown: the upper surface of the dynamometer base 6 is located in the housing 11 and the base 4 is fixed thereon. The base 4 is provided with four concave rectangular grooves along the side. The edges of the rectangular grooves are provided with longitudinal vertical avoidance grooves 401. The vertical avoidance grooves 401 are provided for the leads of the PVDF piezoelectric film 7 to pass through. Figure 7 As shown: the end of the vertical avoidance groove 401 is connected to the bottom wire collecting groove 602 in the center of the dynamometer base 6, and the leads of the PVDF piezoelectric film 7 are collected in the bottom wire collecting groove 602. The side wall of the dynamometer base 6 is provided with a wire outlet hole 601 connected to the bottom wire collecting groove 602. The wire outlet hole 601 is connected to the waterproof wire outlet seat 13 set on the side of the dynamometer base 6. The leads of the PVDF piezoelectric film 7 are collected and fixed in the waterproof wire outlet seat 13. A bottom sealing ring 14 is installed on the outside of the bottom wire collecting groove 602 between the bottom sealing cover 9 and the dynamometer base 6. The bottom sealing ring 14 is installed in the bottom sealing ring groove 604 set on the lower surface of the dynamometer base 6; each rectangular groove has a vertical mounting surface 402 on the side wall of the groove surface, and the four vertical mounting surfaces 402 are installed with horizontal pressure blocks higher than the base 4. Each vertical mounting surface 402 is installed with two first threaded holes 403 to cooperate with the first bolt 5 to install the X-axis. The pressure block 2 or the Y-direction pressure block 3, the X-direction pressure block 2 includes a first X-direction pressure block 201 and a second X-direction pressure block 202. Similarly, the Y-direction pressure block 3 includes a first Y-direction pressure block 301 and a second Y-direction pressure block 302. The first X-direction pressure block 201, the first Y-direction pressure block 301, the second X-direction pressure block 202, and the second Y-direction pressure block 302 are installed in sequence along the circumferential direction; to facilitate the positioning of the horizontal pressure block, a first pin hole 404 is provided on the vertical mounting surface 402 between the two first threaded holes 403.

[0049] Each horizontal pressing block and the vertical mounting surface 402 are pre-tightened with their own PVDF piezoelectric film 7, namely the horizontal PVDF piezoelectric film, which is used to detect the X-direction cutting force, the Y-direction cutting force and the Z-direction torque; Figure 10 As shown, taking the X-direction pressure block 2 or the Y-direction pressure block 3 as an example: each horizontal pressure block is provided with a horizontal PVDF piezoelectric film accommodating groove 304 in the middle of the side surface facing the vertical mounting surface 402, and the horizontal PVDF piezoelectric film is pre-tightened and installed in the horizontal PVDF piezoelectric film accommodating groove 304. The groove depth of the horizontal PVDF piezoelectric film accommodating groove 304 is less than the thickness of the horizontal PVDF piezoelectric film. A through hole 305 is provided on the horizontal pressure block, which is opposite to the first threaded hole 403. The first bolt 5 is assembled in the first threaded hole 403 through the through hole 305. The horizontal pressure block is provided with through holes 306 on the upper and lower sides of the through hole 305, which are opposite to the first pin hole 404, for rapid positioning of the horizontal pressure block.

[0050] like Figure 8 、 9 As shown in the following example, a first X-direction PVDF piezoelectric film 707, a first Y-direction PVDF piezoelectric film 706, a second X-direction PVDF piezoelectric film 705, and a second Y-direction PVDF piezoelectric film 708 are installed between the first X-direction pressing block 201, the first Y-direction pressing block 301, the second X-direction pressing block 202, and the second Y-direction pressing block 302 and their respective vertical mounting surfaces 402; the positive tensile forces exerted on the four PVDF piezoelectric films 7 are respectively recorded as 、 、 、 , it is stipulated that tension is positive and compression is negative.

[0051] The top surface of the horizontal pressure block supports and is equipped with a Z-direction pressure block 1. The outer edge of the lower surface of the Z-direction pressure block 1 is provided with an upper shell groove 105 for clamping the upper edge of the shell 11. The upper shell groove 105 is embedded with a second shell sealing ring 12. The upper and lower edges of the shell 11 are respectively clamped in the lower shell groove 405 and the upper shell groove 105, and the first shell sealing ring 10 and the second shell sealing ring 12 are used to improve the sealing performance; the Z-direction pressure block 1 is installed on the horizontal pressure block by four second bolts 8 installed in the second threaded holes 102, as shown in FIG. Figure 4 、 5 As shown: the upper surface of the Z-direction pressing block 1 is provided with a workpiece mounting hole 103 and a second pin hole 104 between the second threaded hole 102. The workpiece mounting hole 103 is used to connect with the workpiece to be processed. There are two second pin holes 104 and they are located on the same diameter of the Z-direction pressing block 1, which is convenient for locating the center when used. A positioning groove 101 is provided on the inner edge of the Z-direction pressing block 1 to facilitate locating the center when used. Each PVDF piezoelectric film 7 is pre-tightened and installed between each horizontal pressing block and the Z-direction pressing block 1. Figure 10As shown: the upper surface of each horizontal pressing block is provided with a Z-direction PVDF piezoelectric film receiving groove 303, and the Z-direction PVDF piezoelectric film receiving groove 303 is pre-tightened and installed with a Z-direction PVDF piezoelectric film. The groove depth of the Z-direction PVDF piezoelectric film receiving groove 303 is less than the thickness of the Z-direction PVDF piezoelectric film. In this embodiment, the first Z-direction PVDF piezoelectric film 701 is installed on the first Y-direction pressing block 301, the second Z-direction PVDF piezoelectric film 702 is installed on the first X-direction pressing block 201, the third Z-direction PVDF piezoelectric film 703 is installed on the second Y-direction pressing block 302, and the fourth Z-direction PVDF piezoelectric film 704 is installed on the second X-direction pressing block 202; the positive tensile pressures exerted on the four PVDF piezoelectric films 7 are respectively recorded as 、 、 、 , it is stipulated that tension is positive and compression is negative.

[0052] The external six-component cutting force is accurately measured by the arranged PVDF piezoelectric films 7; the output end of each PVDF piezoelectric film 7 is connected to the input channel of the charge amplifier, and the tensile force collected by the PVDF piezoelectric film 7 is converted into a voltage signal. The voltage signals converted from the eight PVDF piezoelectric films 7 are recorded as ~ , characterizing the magnitude of the positive pressure on each PVDF piezoelectric film 7.

[0053] The output end of the charge amplifier is connected to the MCU main control chip through an AD converter. Based on the tensile and compressive forces in three orthogonal directions measured by the eight PVDF piezoelectric films 7, the six-component cutting force and torque are calculated in the main control chip according to the spatial force balance condition, and finally transmitted to the outside through the serial port.

[0054] When used, the following steps are included:

[0055] S1. Install the horizontal pressure blocks on the base 4, where the X-direction pressure blocks 2 and the Y-direction pressure blocks 3 are installed alternately so that the upper surface of the horizontal pressure blocks is higher than the upper surface of the base 4. A PVDF piezoelectric film 7 is pre-tightened between the contact surfaces of the four horizontal pressure blocks and the base 4.

[0056] S2. Install the first shell sealing ring 10 in the lower shell groove 405, install the shell 11, connect the Z-direction pressure block 1 to the upper surface of the horizontal pressure block through the second bolt 8, pre-tighten a PVDF piezoelectric film 7 between the upper surface of each horizontal pressure block and the contact surface of the Z-direction pressure block 1, and the eight PVDF piezoelectric films 7 are used to detect the tensile pressure transmitted by the pressure block. Install the second shell sealing ring 12 in the upper shell groove 105, and insert the upper edge of the shell 11 into the upper shell groove 105, and install the Z-direction pressure block 1.

[0057] S3, the lead wires of the PVDF piezoelectric film 7 are passed through the waterproof outlet seat 13, and the output end of each PVDF piezoelectric film 7 is connected to a charge amplifier to convert the pressure signal into a voltage signal. The voltage signals converted from the eight PVDF piezoelectric films 7 are recorded as ~ , characterizing the tensile force between the corresponding contact surfaces, and connecting the output end of the charge amplifier to the MCU main control chip through an AD converter.

[0058] S4. Place the bottom sealing ring 14 in the bottom sealing ring groove 604, screw the bottom connecting screw 15 into the bottom threaded hole 603, install the bottom sealing cover 9 on the dynamometer base 6 and fix it on the machine tool workbench, install the workpiece on the Z-axis pressure block 1, start the machine tool to start cutting, and the cutting force generated by the tool cutting the workpiece is transmitted to the Z-axis pressure block, and the Z-axis pressure block 1 is transmitted to the X-axis pressure block 2 and the Y-axis pressure block 3.

[0059] Specifically, when the Z-direction pressure block 1 is subjected to a positive X-direction force, the first X-direction PVDF piezoelectric film 707 is pulled and the second X-direction PVDF piezoelectric film 705 is compressed. Conversely, when the Z-direction pressure block 1 is subjected to a negative X-direction force, the first X-direction PVDF piezoelectric film 707 is compressed and the second X-direction PVDF piezoelectric film 705 is pulled. The other piezoelectric films are subjected to shear force and no charge is output.

[0060] When the Z-direction pressure block 1 is subjected to a positive Y-direction force, the first Y-direction PVDF piezoelectric film 706 is pulled and the second Y-direction PVDF piezoelectric film 708 is compressed. Conversely, when the Z-direction pressure block is subjected to a negative Y-direction force, the first Y-direction PVDF piezoelectric film 706 is compressed and the second Y-direction PVDF piezoelectric film 708 is pulled. The other piezoelectric films are subjected to shear force and no charge is output.

[0061] When the Z-direction pressure block 1 is subjected to a positive Z force, the Z-direction PVDF piezoelectric film (i.e., the first Z-direction PVDF piezoelectric film 701, the second Z-direction PVDF piezoelectric film 702, the third Z-direction PVDF piezoelectric film 703, and the fourth Z-direction PVDF piezoelectric film 704) is pulled. Conversely, when the Z-direction pressure block 1 is subjected to a negative Z force, the Z-direction PVDF piezoelectric film is compressed, and the other piezoelectric films are subjected to shear force, and no charge is output.

[0062] When the Z-axis pressing block 1 is When the torque is positive, the first Z-direction PVDF piezoelectric film 701, the fourth Z-direction PVDF piezoelectric film 704, and the first Y-direction PVDF piezoelectric film 706 are pulled, and the second Z-direction PVDF piezoelectric film 702, the third Z-direction PVDF piezoelectric film 703, and the second Y-direction PVDF piezoelectric film 708 are compressed. When the torque is negative, the first Z-direction PVDF piezoelectric film 701, the fourth Z-direction PVDF piezoelectric film 704, and the first Y-direction PVDF piezoelectric film 706 are compressed, the second Z-direction PVDF piezoelectric film 702, the third Z-direction PVDF piezoelectric film 703, and the second Y-direction PVDF piezoelectric film 708 are pulled, and the other piezoelectric films are subjected to shear force, and no charge is output.

[0063] When the Z-axis pressing block 1 is When the torque is positive, the third Z-direction PVDF piezoelectric film 703, the fourth Z-direction PVDF piezoelectric film 704, and the second X-direction PVDF piezoelectric film 705 are pulled, and the first Z-direction PVDF piezoelectric film 701, the second Z-direction PVDF piezoelectric film 702, and the first X-direction PVDF piezoelectric film 707 are compressed. On the contrary, when the Z-direction pressure block 1 is subjected to When the torque is negative, the third Z-direction PVDF piezoelectric film 703, the fourth Z-direction PVDF piezoelectric film 704, and the second X-direction PVDF piezoelectric film 705 are compressed, the first Z-direction PVDF piezoelectric film 701, the second Z-direction PVDF piezoelectric film 702, and the first X-direction PVDF piezoelectric film 707 are pulled, and the other piezoelectric films are subjected to shear force, and no charge is output.

[0064] When the Z-axis pressing block 1 is When the positive torque is applied, the X-direction PVDF piezoelectric film (i.e., the first X-direction PVDF piezoelectric film 707 and the second X-direction PVDF piezoelectric film 705) and the Y-direction PVDF piezoelectric film (i.e., the first Y-direction PVDF piezoelectric film 706 and the second Y-direction PVDF piezoelectric film 708) are pulled. On the contrary, when the Z-direction pressing block 1 is subjected to the positive torque, the X-direction PVDF piezoelectric film (i.e., the first Y-direction PVDF piezoelectric film 707 and the second Y-direction PVDF piezoelectric film 708) are pulled. When the torque is negative, the X-direction PVDF piezoelectric film and the Y-direction PVDF piezoelectric film are compressed, and the other piezoelectric films are subjected to shear force, and no charge is output.

[0065] The positive tensile force and voltage signal on each piezoelectric film ~ The corresponding relationship between them can be calculated and corresponded by the following formula:

[0066]

[0067] Where:

[0068] ~ Indicates the calibration coefficient;

[0069] like Figure 8As shown: According to the balance relationship of the spatial force system, all forces are simplified to the center point O, and a coordinate system is established with the center of the upper mounting surface of the Z-axis pressure block 1 as the origin, where the xoy plane coincides with the upper mounting surface of the Z-axis pressure block 1, the xoz plane coincides with the mounting surface of the Y-axis pressure block 3 on the base 4, and the yoz plane coincides with the mounting surface of the X-axis pressure block 2 on the base 4. It can be obtained 、 、 、 、 、 and 、 、 、 、 、 、 、 The conversion between them can be obtained by the following formula:

[0070]

[0071] Where,

[0072] Indicates the distance from the PVDF piezoelectric film to the xoz plane in the X direction or the distance from the PVDF piezoelectric film to the yoz plane in the Y direction;

[0073] represents the distance from the first Z-direction PVDF piezoelectric film 701 or the third Z-direction PVDF piezoelectric film 703 to the xoz plane or the distance from the second Z-direction PVDF piezoelectric film 702 or the fourth Z-direction piezoelectric film 704 to the yoz plane;

[0074] represents the distance from the second Z-direction PVDF piezoelectric film 702, the fourth Z-direction PVDF piezoelectric film 704 to the xoz plane, or the distance from the first Z-direction PVDF piezoelectric film 701, the third Z-direction piezoelectric film 703 to the xoz plane;

[0075] Indicates the distance from the center of the PVDF piezoelectric film in the X direction or the center of the PVDF piezoelectric film in the Y direction to the xoy plane;

[0076] like Figure 9 、 11 As shown: The eight-channel charge amplifier amplifies the piezoelectric film signal and converts it into a voltage signal. The voltage signal is collected by the eight-channel AD converter and digitally transmitted to the MCU main control. The voltage signal processing and calculation are completed in the main control chip, that is, the voltage signal ~ arrive 、 、 、 、 、 、 、 , and finally to 、 、 、 、 、 The six-component cutting force and moment are obtained through conversion calculation and output through 485 serial port data.

[0077] The scope of protection claimed by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention may have various variations and modifications. Any modifications, improvements and equivalent substitutions made within the concept and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A six-component cutting force and torque dynamometer based on piezoelectric film, characterized in that: The invention comprises a bottom sealing cover (9), a dynamometer base (6) is installed above the bottom sealing cover (9), a shell (11) is installed above the dynamometer base (6) along the outer edge, the upper surface of the dynamometer base (6) is located in the shell (11), and a base (4) is fixed thereon, the base (4) is provided with four concave rectangular grooves along the side surface, each rectangular groove has a vertical mounting surface (402) on the side wall of the groove surface, and horizontal pressure blocks higher than the base (4) are installed on the four vertical mounting surfaces (402), and the horizontal pressure blocks include X-direction pressure blocks (2) and Y-direction pressure blocks (3) installed alternately. ), each horizontal pressing block and the vertical mounting surface (402) are pre-tightened with their own PVDF piezoelectric film (7), the top surface of the horizontal pressing block supports and is jointly equipped with a Z-direction pressing block (1), the outer edge of the lower surface of the Z-direction pressing block (1) is provided with an upper shell groove (105) for clamping the upper edge of the shell (11), each horizontal pressing block and the Z-direction pressing block (1) are pre-tightened with their own PVDF piezoelectric film (7), the output end of each PVDF piezoelectric film (7) is connected to the input channel of the charge amplifier, and the output end of the charge amplifier is connected to the MCU main control chip through the AD converter.

2. A six-component cutting force and torque dynamometer based on piezoelectric film according to claim 1, characterized in that: Each vertical mounting surface (402) is provided with two first threaded holes (403) for mounting an X-direction pressing block (2) or a Y-direction pressing block (3) in cooperation with a first bolt (5), wherein the X-direction pressing block (2) and the Y-direction pressing block (3) are orthogonally distributed.

3. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 2, characterized in that: The vertical mounting surface (402) is provided with a first pin hole (404) between the two first threaded holes (403).

4. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 1, characterized in that: The Z-direction pressing block (1) is mounted on the horizontal pressing block via four second bolts (8) threaded through the second threaded holes (102); a workpiece mounting hole (103) and a second pin hole (104) are provided on the upper surface of the Z-direction pressing block (1) between the second threaded holes (102); and a positioning groove (101) is provided on the inner edge of the Z-direction pressing block (1).

5. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 1, characterized in that: A longitudinal vertical avoidance groove (401) is formed at the groove edge of the rectangular groove, and the end of the vertical avoidance groove (401) is connected to the bottom wire collection groove (602) in the center of the dynamometer base (6). A wire outlet hole (601) connected to the bottom wire collection groove (602) is formed on the side wall of the dynamometer base (6), and the wire outlet hole (601) is connected to a waterproof wire outlet seat (13) provided on the side of the dynamometer base (6).

6. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 1, characterized in that: The upper surface edge of the dynamometer base (6) is provided with a lower shell groove (405) for clamping the lower edge of the shell (11), the lower shell groove (405) is embedded with a first shell sealing ring (10), and the upper shell groove (105) is embedded with a second shell sealing ring (12).

7. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 5, characterized in that: The bottom sealing cover (9) is installed on the dynamometer base (6) by passing the bottom connecting screw (15) through the bottom threaded hole (603). A bottom sealing ring (14) is installed between the bottom sealing cover (9) and the dynamometer base (6) on the outside of the bottom collection groove (602). The bottom sealing ring (14) is installed in a bottom sealing ring groove (604) provided on the lower surface of the dynamometer base (6).

8. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 1, characterized in that: The upper surface of each horizontal pressing block is provided with a Z-direction PVDF piezoelectric film receiving groove (303), wherein a Z-direction PVDF piezoelectric film is pre-tightenedly installed in the Z-direction PVDF piezoelectric film receiving groove (303), and the groove depth of the Z-direction PVDF piezoelectric film receiving groove (303) is less than the thickness of the Z-direction PVDF piezoelectric film.

9. The six-component cutting force and torque dynamometer based on piezoelectric film according to claim 1, characterized in that: A horizontal PVDF piezoelectric film receiving groove (304) is provided in the middle of the side surface of each horizontal pressing block facing the vertical mounting surface (402), wherein the horizontal PVDF piezoelectric film is pre-tightened and mounted in the horizontal PVDF piezoelectric film receiving groove (304), and the groove depth of the horizontal PVDF piezoelectric film receiving groove (304) is less than the thickness of the horizontal PVDF piezoelectric film.

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