A three-dimensional piezoelectric force measuring device integrated into the spindle

Abstract

This invention belongs to the field of signal monitoring technology and discloses a three-dimensional piezoelectric force measuring device integrated into a spindle, including a spindle, an adapter tool holder, a housing, a piezoelectric sensor, and a circuit carrier. Both the housing and the piezoelectric sensor are annular. The housing is fixed to the lower end face of the spindle and includes an upper connecting shell, a middle frame, and a lower connecting shell, which are sealed from top to bottom. The upper end face of the piezoelectric sensor is tightly fitted to the mating end face of the spindle, and a sealing rubber ring is provided between the lower end face of the piezoelectric sensor and the lower connecting shell. The housing and the piezoelectric sensor form a sealed cavity, and the circuit carrier is installed inside the cavity. The inner diameter surface of the piezoelectric sensor is clearance-fitted with the adapter tool holder. This invention measures cutting force by installing a piezoelectric sensor on the mating end face of the spindle HSK tool holder and fixing the housing and signal acquisition system to the spindle. Switching tool holders does not affect the continuous measurement of cutting force, realizing the application scenario of a single force measuring device adapting to multiple tool holders.

Description

Technical Field

[0001] This invention belongs to the field of signal monitoring technology, and more specifically, relates to a three-dimensional piezoelectric force measuring device integrated into a spindle. Background Technology

[0002] Cutting force has always been an important research subject in the study of metal cutting mechanisms and machining processes. The value of cutting force determines the energy consumption during machining and affects the deformation of the overall process system. Furthermore, cutting force directly affects chip morphology, workpiece surface quality, cutting heat, and overall vibration during machining.

[0003] The magnitude of cutting force changes can reflect the wear or breakage of the tool in real time. Furthermore, cutting force provides a theoretical basis for improving machining accuracy, studying metal cutting mechanisms, and researching machining processes. Therefore, real-time and accurate monitoring of cutting force is of great significance for improving machining technology.

[0004] In typical cutting force measurement studies, sensors and circuitry are often fixed to the tool holder. However, for complex part machining, it is often necessary to use multiple tool holders from the tool magazine for tool changing. On the one hand, the force-measuring tool holder with the sensor and circuitry is bulky and prone to interference during tool changing. On the other hand, multiple tool holders require force-measuring structures and circuitry, significantly increasing costs. Furthermore, the cutting force signals measured by multiple tool holders are interrupted during tool changing, requiring a re-establishment of the connection to the host computer when switching to a new tool holder, resulting in discontinuous cutting force signals in time.

[0005] Given the current shortcomings of tool holder-type rotary force gauges in measuring cutting forces, there is an urgent need to design and develop a new type of force measuring device that integrates a force sensor and a signal transmission system on the spindle to meet the demand for low-cost, continuous use of force measuring devices in industrial settings. Summary of the Invention

[0006] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a three-dimensional piezoelectric force measuring device integrated into the spindle, thereby solving the technical problems of high costs caused by fixing the force measuring device to the tool holder during milling and other machining processes, requiring separate design of the measuring device for each tool holder, and the interruption of cutting force signals caused by tool magazine changes.

[0007] To achieve the above objectives, according to one aspect of the present invention, a three-dimensional piezoelectric force measuring device integrated into a spindle is provided, comprising a spindle 1, an adapter tool holder 2, a housing 3, a piezoelectric sensor 6, and a circuit carrier 9; both the housing 2 and the piezoelectric sensor 6 are annular; the housing 3 is fixed to the lower end face of the spindle 1, and the housing 3 includes an upper connecting shell 31, a middle frame 32, and a lower connecting shell 33 that are sealed from top to bottom; the upper end face of the piezoelectric sensor 6 is tightly fitted with the mating end face of the spindle 1, and a sealing rubber ring 11 is provided between the lower end face of the piezoelectric sensor 6 and the lower connecting shell 33; the housing 3 and the piezoelectric sensor 6 form a sealed cavity, and the circuit carrier 9 is installed in the cavity; the inner diameter surface of the piezoelectric sensor 6 is clearance-fitted with the adapter tool holder 2.

[0008] Preferably, the upper surface of the piezoelectric sensor 6 is provided with three sets of raised contacts, each set of raised contacts containing two raised points.

[0009] Preferably, the outer diameter surface of the piezoelectric sensor 6 is fixed to the upper connecting shell 31 by a plurality of sensor fixing screws 13.

[0010] Preferably, the upper connecting shell 31 and the middle frame 32 are connected by sealant, and the middle frame 32 and the lower connecting shell 33 are connected by sealant; the upper connecting shell 31 and the lower connecting shell 33 are made of metal, and the middle frame 32 is made of composite material.

[0011] Preferably, the head of the adapter handle 2 is a standard HSK interface, and a cylindrical mating surface 22 is provided between the short conical surface 21 of the adapter handle 2 and the mating end face 23 of the handle. The inner diameter surface of the piezoelectric sensor 6 is in clearance fit with the cylindrical mating surface 22 of the adapter handle 2.

[0012] Preferably, it also includes a power switch 14 and a magnetic charging port 15; the outer circular surface of the housing 3 is equipped with a power switch 14 connected to the power supply circuit, and the bottom is equipped with a magnetic charging port 15.

[0013] Preferably, the circuit carrier 9 includes an upper circuit board and a lower circuit board, which are connected by a hexagonal stud 10. A circuit board fixing nut 8 is screwed into the upper end of the hexagonal stud 10 to fix the upper circuit board and the lower circuit board. The lower circuit board is fixed to the bottom of the lower connecting shell 33 by a circuit board fixing bolt 12.

[0014] Preferably, the upper circuit board includes a three-channel charge amplifier circuit, and the lower circuit board includes a three-channel A / D conversion circuit and a wireless transmission module.

[0015] Preferably, the lower end face of the spindle 1 is provided with a threaded hole, and the upper connecting shell 31 is fixed to the spindle by screwing a plurality of shell top mounting screws 7 into the threaded hole.

[0016] Preferably, it also includes a round nut 5 and a spring collet 4. When installing the tool, after inserting the tool into the adapter handle 2, the spring collet 4 is deformed and clamped by tightening the round nut 5.

[0017] In summary, compared with the prior art, the three-dimensional piezoelectric force measuring device integrated into the spindle provided by the present invention has the following advantages:

[0018] 1. Compared with existing toolholder-type piezoelectric rotary force gauges, this invention measures cutting force by installing a piezoelectric sensor on the mating end face of the spindle HSK toolholder and fixing the housing and signal acquisition system to the spindle. This does not restrict automated toolholder switching, and toolholder switching does not affect the continuous measurement of cutting force. The combination of the spindle and the force measurement structure has better economic value and can improve work efficiency and facilitate the measurement of cutting force in multi-toolholder machining processes.

[0019] 2. This invention integrates a three-dimensional piezoelectric force measuring device into the spindle, enabling a single force measuring device to adapt to multiple tool holders in various application scenarios. It has advantages such as high sensitivity, quick installation, and strong adaptability.

[0020] 3. The wireless transmission in this invention is based on WiFi, which can meet the requirements for high-speed acquisition of cutting force over long distances. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a three-dimensional piezoelectric force measuring device integrated into the main shaft according to the present invention;

[0022] Figure 2 This is a cross-sectional schematic diagram of a three-dimensional piezoelectric force measuring device integrated into the main shaft according to the present invention;

[0023] Figure 3 This is an exploded view of a three-dimensional piezoelectric force measuring device integrated into the main shaft according to the present invention;

[0024] Figure 4 This is a schematic diagram of the structure of an adapter tool holder for a three-dimensional piezoelectric force measuring device integrated into the spindle according to the present invention;

[0025] Figure 5 This is a schematic diagram of an information acquisition and transmission system for a three-dimensional piezoelectric force measuring device integrated into the main shaft according to the present invention.

[0026] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0027] 1-Spindle, 2-Adaptor tool holder, 3-Housing, 4-Spring collet, 5-Round nut, 6-Piezoelectric sensor, 7-Housing top mounting screw, 8-Circuit board fixing nut, 9-Circuit carrier, 10-Hexagonal stud, 11-Sealing rubber ring, 12-Circuit board fixing bolt, 13-Sensor fixing screw, 14-Power switch, 15-Magnetic charging port, 21-Short conical surface, 22-Cylindrical mating surface, 23-Tool holder mating end face, 31-Upper connecting shell, 32-Middle frame, 33-Lower connecting shell. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Please see Figure 1 This invention provides a three-dimensional piezoelectric force measuring device integrated into a spindle, comprising a spindle 1, an adapter tool holder 2, a housing 3, a piezoelectric sensor 6, and a circuit carrier 9; both the housing 2 and the piezoelectric sensor 6 are annular; please refer to [link to relevant documentation]. Figure 2 and Figure 3 The outer shell 3 is fixed to the lower end face of the spindle 1. The outer shell 3 includes an upper connecting shell 31, a middle frame 32, and a lower connecting shell 33 that are sealed from top to bottom. The upper end face of the piezoelectric sensor 6 is tightly fitted with the mating end face of the spindle 1. A sealing rubber ring 11 is provided between the lower end face of the piezoelectric sensor 6 and the lower connecting shell 33. The outer shell 3 and the piezoelectric sensor 6 form a sealed cavity, and the circuit carrier 9 is installed in the cavity. The inner diameter surface of the piezoelectric sensor 6 is clearance-fitted with the adapter tool holder 2.

[0030] In this embodiment, the piezoelectric sensor 6 is custom-designed, with three sets of raised contacts evenly distributed on its upper surface for sensing force signals. Each set of raised contacts contains two protrusions to share the tension of the spindle 1 and improve the strength of the piezoelectric sensor. The mating end face of the raised contacts and the spindle 1 is tightly fitted under the tension of the spindle broach, and a bending moment is generated under the action of cutting force. Different normal pressures are sensed at the three sets of raised contacts to calculate the cutting force. The mating end face 22 of the adapter tool holder 2 is also tightly fitted to the lower surface of the piezoelectric sensor 6 under the action of the spindle broach tension. When the spindle releases the broach, the outer diameter surface of the piezoelectric sensor 6 is fixed to the upper connecting shell 31 by multiple sensor fixing screws 13. At this time, the piezoelectric sensor 6 is in a relaxed state, and other adapter tool holders can be replaced according to actual usage requirements.

[0031] The upper connecting shell 31 is connected to the middle frame 32 with sealant, and the middle frame 32 is connected to the lower connecting shell 33 with sealant, providing waterproof and dustproof protection. The upper connecting shell 31 and the lower connecting shell 33 are made of metal, providing good electromagnetic shielding and reducing power frequency interference signals. The middle frame 32 is made of composite material, which reduces the obstruction of WiFi signals by the metal shell. The lower end face of the spindle 1 is provided with threaded holes, and the upper connecting shell 31 is fixed to the spindle by screwing several shell top mounting screws 7 into the threaded holes.

[0032] Please see Figure 4 The adapter tool holder 2 is modified from the standard HSK tool holder, and its head is a standard HSK interface. A cylindrical mating surface 22 is provided between the short conical surface 21 of the adapter tool holder 2 and the mating end face 23 of the tool holder. The inner diameter surface of the piezoelectric sensor 6 is in clearance fit with the cylindrical mating surface 22 of the adapter tool holder 2.

[0033] This embodiment of a three-dimensional piezoelectric force measuring device integrated into a spindle also includes a power switch 14 and a magnetic charging port 15; the power switch 14 connected to the power supply circuit is installed on the outer circular surface of the housing 3, and the magnetic charging port 15 is installed at the bottom. It also includes a round nut 5 and a spring collet 4. When installing a tool, after inserting the tool into the adapter tool holder 2, the spring collet 4 is deformed and clamped by tightening the round nut 5.

[0034] like Figure 2 As shown, the circuit carrier 9 includes an upper circuit board and a lower circuit board, which are connected by hexagonal studs 10. Circuit board fixing nuts 8 are screwed into the upper end of the hexagonal studs 10 to fix the upper and lower circuit boards. The lower circuit board is fixed to the bottom of the lower connecting shell 33 by circuit board fixing bolts 12. The upper circuit board contains a three-channel charge amplifier circuit, and the lower circuit board contains a three-channel A / D conversion circuit and a wireless transmission module. The upper and lower circuit boards are connected by an FFC cable, and the antenna of the wireless transmission module is glued to the middle frame 32 of the shell 3.

[0035] like Figure 4 As shown, under the action of cutting force, the piezoelectric sensor 6 outputs different amounts of charge through different channels to the charge amplifier module. The analog signal is converted into a digital signal by a three-channel A / D conversion circuit and transmitted to the wireless receiver via a wireless transmission module. The signal is then processed and displayed by the host computer. During monitoring, the entire system is powered by a lithium battery, which is charged via a magnetic charging port on the bottom of the casing 3 connected to a magnetic charging head. The wireless transmission system is based on WiFi, enabling it to meet the requirements for high-speed acquisition of cutting force over long distances.

[0036] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A three-dimensional piezoelectric force measuring device integrated into a spindle, characterized in that: The device includes a spindle (1), a tool holder (2), a housing (3), a piezoelectric sensor (6), and a circuit carrier (9). Both the housing (3) and the piezoelectric sensor (6) are annular. The housing (3) is fixed to the mating end face of the spindle (1). The housing (3) includes an upper connecting shell (31), a middle frame (32), and a lower connecting shell (33) that are sealed from top to bottom. The upper end face of the piezoelectric sensor (6) is tightly fitted to the mating end face of the spindle (1), and a sealing rubber ring (11) is provided between the lower end face of the piezoelectric sensor (6) and the lower connecting shell (33). The housing (3) and the piezoelectric sensor (6) form a sealed cavity, and the circuit carrier (9) is installed inside the cavity. The inner diameter surface of the piezoelectric sensor (6) is aligned with the inner diameter surface of the tool holder (2). Clearance fit; the upper end face of the piezoelectric sensor (6) is evenly provided with three sets of raised contacts, each set of raised contacts includes two protrusions; the outer diameter surface of the piezoelectric sensor (6) is fixed to the upper connecting shell (31) by multiple sensor fixing screws (13); the upper connecting shell (31) and the middle frame (32) are connected by sealant, and the middle frame (32) and the lower connecting shell (33) are connected by sealant; the upper connecting shell (31) and the lower connecting shell (33) are made of metal materials, and the middle frame (32) is made of composite material; a cylindrical mating surface (22) is provided between the short conical surface (21) of the adapter handle (2) and the mating end face (23) of the handle, and the inner diameter surface of the piezoelectric sensor (6) and the cylindrical mating surface (22) of the adapter handle (2) are in clearance fit.

2. The three-dimensional piezoelectric force measuring device integrated into the spindle as described in claim 1, characterized in that: The head of the adapter handle (2) has a standard HSK interface.

3. The three-dimensional piezoelectric force measuring device integrated into the spindle as described in claim 1, characterized in that: It also includes a power switch (14) and a magnetic charging port (15); the outer surface of the housing (3) is equipped with a power switch (14) connected to the power supply circuit, and the bottom is equipped with a magnetic charging port (15).

4. The three-dimensional piezoelectric force measuring device integrated into the spindle as described in claim 1, characterized in that: The circuit carrier (9) includes an upper circuit board and a lower circuit board. The upper circuit board and the lower circuit board are connected by a hexagonal stud (10). A circuit board fixing nut (8) is screwed into the upper end of the hexagonal stud (10) to fix the upper circuit board and the lower circuit board. The lower circuit board is fixed to the bottom of the lower connecting shell (33) by a circuit board fixing bolt (12).

5. The three-dimensional piezoelectric force measuring device integrated into the spindle as described in claim 4, characterized in that: The upper circuit board includes a three-channel charge amplifier circuit, and the lower circuit board includes a three-channel A / D conversion circuit and a wireless transmission module.

6. The three-dimensional piezoelectric force measuring device integrated into the spindle as described in claim 1, characterized in that: The mating end face of the spindle (1) is provided with a threaded hole, and the upper connecting shell (31) is fixed to the spindle by screwing into the threaded hole with several shell top mounting screws (7).

7. The three-dimensional piezoelectric force measuring device integrated into the spindle as described in claim 1, characterized in that: It also includes a round nut (5) and a spring collet (4). When installing the tool, after inserting the tool into the matching tool holder (2), the spring collet (4) is deformed and clamped by tightening the round nut (5).

Images