Three-dimensional piezoelectric force measuring device integrated on main shaft

Abstract

The invention belongs to the related technical field of signal monitoring, and discloses a three-dimensional piezoelectric force measuring device integrated on a main shaft, which comprises the main shaft, an adaptive knife handle, a shell, a piezoelectric sensor and a circuit carrier, the shell and the piezoelectric sensor are both in a circular ring shape. The shell is fixed on the lower end surface of the main shaft and comprises an upper connecting shell, a middle frame and a lower connecting shell which are hermetically connected from top to bottom; the upper end face of the piezoelectric sensor is tightly attached to the matching end face of the main shaft, a sealing rubber ring is arranged between the lower end face of the piezoelectric sensor and the lower connecting shell, a closed cavity is defined by the shell and the piezoelectric sensor, and the circuit carrier is installed in the cavity; and the inner diameter surface of the piezoelectric sensor is in clearance fit with the adaptive cutter handle. The piezoelectric sensor is installed on the matching end face of the main shaft HSK knife handle, the shell and the signal collecting system are fixedly connected to the main shaft to measure the cutting force, continuous measurement of the cutting force is not affected by knife handle switching, and the application scene that a single force measuring device is matched with a plurality of knife handles is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to signal monitoring, and more specifically, relates to a three-dimensional piezoelectric force measuring device integrated in a main shaft. Background Art

[0002] Cutting force has always been an important research object in the study of metal cutting mechanism and processing technology. The cutting force value determines the energy consumption during processing and affects the deformation of the overall process system. The cutting force directly affects the chip shape, workpiece surface quality, cutting heat, and overall vibration during processing.

[0003] Changes in the size of cutting force can reflect the wear or breakage of the tool in real time, and cutting force provides a theoretical basis for improving machining accuracy, metal cutting mechanism research and machining process research. Therefore, real-time and accurate monitoring of cutting force is of great significance to improving the level of machining technology.

[0004] In common cutting force measurement research, sensors and circuit carriers are often fixed to tool holders. However, for complex parts processing, it is often necessary to call multiple tool holders in the tool magazine to achieve tool change. On the one hand, the force measuring tool holder equipped with sensors and circuit carriers is large in size and easily causes interference in the tool change process. On the other hand, multiple tool holders need to be equipped with force measuring structures and circuit carriers, which greatly increases the cost. At the same time, the cutting force signals measured by multiple tool holders will be interrupted during the tool change process. When switching to a new tool holder, the connection with the host computer needs to be re-established, and the measured cutting force signals are discontinuous in time.

[0005] In view of the shortcomings of the current tool holder type rotary dynamometer in measuring cutting force, it is urgent to design and develop a new type of force measuring device that integrates the force sensor and signal transmission system on the spindle to meet the needs of low-cost continuous use of force measuring devices in industrial sites. Summary of the invention

[0006] In response to the above defects or improvement needs of the prior art, the present invention provides a three-dimensional piezoelectric force measuring device integrated in the spindle, thereby solving the technical problems of high cost caused by fixing the force measuring device to the tool holder during milling and other processing, and the need to design a separate measuring device for each tool holder, as well as the interruption of cutting force signals caused by tool changing in the tool magazine.

[0007] To achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a three-dimensional piezoelectric force measuring device integrated in a spindle, comprising a spindle 1, an adaptor handle 2, a housing 3, a piezoelectric sensor 6, and a circuit carrier 9; the housing 2 and the piezoelectric sensor 6 are both in an annular shape; the housing 3 is fixed to the lower end face of the spindle 1, and the housing 3 comprises an upper connecting shell 31, a middle frame 32, and a lower connecting shell 33 which are sealed and connected from top to bottom; the upper end face of the piezoelectric sensor 6 is tightly fitted with the matching end face of the spindle 1, and a sealing rubber ring 11 is arranged 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 closed cavity, and the circuit carrier 9 is installed in the cavity; the inner diameter surface of the piezoelectric sensor 6 is gap-fitted with the adaptor handle 2.

[0008] Preferably, three groups of raised contacts are evenly distributed on the upper end surface of the piezoelectric sensor 6, and each group of raised contacts includes two raised contacts.

[0009] Preferably, the outer diameter surface of the piezoelectric sensor 6 is fixed to the upper connecting shell 31 by a plurality of force 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 materials, and the middle frame 32 is made of composite materials.

[0011] Preferably, the head of the adapter handle 2 is a standard HSK interface, a cylindrical mating surface 22 is provided between the short conical surface 21 of the adapter handle 2 and the handle mating end surface 23, and the inner diameter surface of the piezoelectric sensor 6 is clearance-fitted 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 circumferential surface of the housing 3 is provided with a power switch 14 connected to the power supply circuit, and the bottom is provided with a magnetic charging port 15.

[0013] Preferably, 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, the 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, and the lower circuit board is fixed to the bottom of the lower connecting shell 33 by the circuit board fixing bolts 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, a threaded hole is provided on the lower end surface of the main shaft 1, and the upper connecting shell 31 is fixed to the main shaft by screwing a plurality of housing top mounting screws 7 into the threaded hole.

[0016] Preferably, it also includes a round nut 5 and a spring chuck 4. When installing the tool, after the tool is inserted into the adapter handle 2, the round nut 5 is tightened to deform the spring chuck 4 to clamp the tool.

[0017] In general, compared with the prior art, the above technical solution conceived by the present invention provides a three-dimensional piezoelectric force measuring device integrated in the main shaft, which has the following beneficial effects:

[0018] 1. Compared with the existing tool holder type piezoelectric rotary dynamometer, the present invention measures the cutting force by installing a piezoelectric sensor on the mating end face of the spindle HSK tool holder, fixing the housing and the signal acquisition system on the spindle, and will not limit the automatic switching of tool holders. Switching tool holders does not affect the continuous measurement of cutting force. The combination of the spindle and the force measuring structure has better economic value, can improve work efficiency, and is convenient for measuring cutting force in the multi-tool holder processing process.

[0019] 2. The present invention integrates a three-dimensional piezoelectric force measuring device into the main shaft, realizing the application scenario of a single force measuring device adapting to multiple tool handles, and has the advantages of high sensitivity, quick installation, and strong adaptability.

[0020] 3. The wireless transmission in the present invention is realized based on WiFi, which can meet the demand for high-speed collection of long-distance cutting force. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0023] Figure 3 It is an exploded schematic diagram of a three-dimensional piezoelectric force measuring device integrated in a main shaft of the present invention;

[0024] Figure 4 It is a structural schematic diagram of an adaptable tool handle of a three-dimensional piezoelectric force measuring device integrated in a main shaft of the present invention;

[0025] Figure 5 It is a schematic diagram of an information collection and transmission system of a three-dimensional piezoelectric force measuring device integrated in a main shaft of the present invention.

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

[0027] 1-spindle, 2-adapter handle, 3-housing, 4-spring chuck, 5-round nut, 6-piezoelectric sensor, 7-housing top mounting screw, 8-circuit board fixing nut, 9-circuit carrier, 10-hexagonal head stud, 11-sealing rubber ring, 12-circuit board fixing bolt, 13-sensor fixing screw, 14-power switch, 15-magnetic charging port, 21-short cone surface, 22-cylindrical mating surface, 23-handle mating end face, 31-upper connecting shell, 32-middle frame, 33-lower connecting shell. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] See also Figure 1 The present invention provides a three-dimensional piezoelectric force measuring device integrated in a spindle, comprising a spindle 1, an adaptable tool handle 2, a housing 3, a piezoelectric sensor 6, and a circuit carrier 9; the housing 2 and the piezoelectric sensor 6 are both in annular shape; please refer to Figure 2 and Figure 3 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 which are sealed and connected from top to bottom; the upper end face of the piezoelectric sensor 6 is tightly fitted with the matching end face of the spindle 1, and a sealing rubber ring 11 is arranged 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 closed cavity, and the circuit carrier 9 is installed in the cavity; the inner diameter surface of the piezoelectric sensor 6 is gap-matched with the adapter handle 2.

[0030] In this embodiment, the piezoelectric sensor 6 is custom-designed, and three groups of raised contacts are evenly distributed on its upper end surface for sensing force signals. Each group of raised contacts includes two raised points, which are used to share the pulling force of the spindle 1 and improve the strength of the piezoelectric sensor. The raised contacts and the mating end surface of the spindle 1 fit tightly under the pulling force of the spindle broach, and generate bending moments under the action of the cutting force. Different positive pressures are sensed at the three groups of raised contacts to calculate the cutting force. The tool holder mating end surface 22 of the adapter tool holder 2 also fits tightly with the lower surface of the piezoelectric sensor 6 under the pulling force of the spindle broach. When the spindle loosens the broach, the outer diameter surface of the piezoelectric sensor 6 is fixed to the upper connecting shell 31 by multiple force sensor fixing screws 13. At this time, the piezoelectric sensor 6 is in a relaxed state and can be replaced with other adapter tool holders according to actual use requirements.

[0031] The upper connecting shell 31 is connected to the middle frame 32 by sealant, and the middle frame 32 is connected to the lower connecting shell 33 by sealant, which has waterproof and dustproof effects; the upper connecting shell 31 and the lower connecting shell 33 are made of metal materials, which can provide good electromagnetic shielding function and reduce power frequency interference signals. The middle frame 32 is a composite material, which can reduce the metal shell's blocking of WiFi signals. The lower end surface of the main shaft 1 is provided with a threaded hole, and the upper connecting shell 31 is fixed to the main shaft by screwing a number of housing top mounting screws 7 into the threaded hole.

[0032] See also Figure 4 The adapter handle 2 is modified from a standard HSK handle, and its head is a standard HSK interface. A cylindrical mating surface 22 is provided between the short conical surface 21 of the adapter handle 2 and the mating end surface 23 of the handle, and the inner diameter surface of the piezoelectric sensor 6 is clearance-fitted with the cylindrical mating surface 22 of the adapter handle 2.

[0033] In this embodiment, a three-dimensional piezoelectric force measuring device integrated in the spindle also includes a power switch 14 and a magnetic charging port 15; the outer cylindrical 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. It also includes a round nut 5 and a spring chuck 4. When installing the tool, after the tool is inserted into the adapter handle 2, the round nut 5 is tightened to deform the spring chuck 4 to clamp the tool.

[0034] like Figure 2 As shown, 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, the circuit board fixing nut 8 is screwed into the upper end of the hexagonal stud 10, and is used to fix the upper circuit board and the lower circuit board, and the lower circuit board is fixed to the bottom of the lower connecting shell 33 by a circuit board fixing bolt 12. 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. The upper circuit board and the lower circuit board 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, the piezoelectric sensor 6 outputs different charges from different channels to the charge amplifier module under the action of cutting force, and converts the analog quantity into a digital signal through the three-channel A / D conversion circuit and sends it to the wireless receiver through the wireless transmission module, which is processed and displayed by the host computer. During the monitoring process, the entire system is powered by a lithium battery, which is charged by connecting the magnetic suction head through the magnetic suction charging port on the bottom of the shell 3. The wireless transmission system is based on WiFi and can meet the needs of high-speed collection of long-distance cutting force.

[0036] It will be easily understood by those skilled in the art that 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 and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional piezoelectric force measuring device integrated in a spindle, characterized in that: The invention comprises a main shaft (1), an adaptor handle (2), a housing (3), a piezoelectric sensor (6), and a circuit carrier (9); the housing (2) and the piezoelectric sensor (6) are both annular; the housing (3) is fixed to the lower end face of the main shaft (1), and the housing (3) comprises an upper connecting shell (31), a middle frame (32), and a lower connecting shell (33) which are sealed from top to bottom; the upper end face of the piezoelectric sensor (6) is tightly fitted with the matching end face of the main shaft (1), a sealing rubber ring (11) is arranged 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 closed cavity, and the circuit carrier (9) is installed in the cavity; the inner diameter surface of the piezoelectric sensor (6) is loosely matched with the adaptor handle (2).

2. A three-dimensional piezoelectric force measuring device integrated into a main shaft as claimed in claim 1, characterized in that: The upper end surface of the piezoelectric sensor (6) is evenly provided with three groups of raised contacts, each group of raised contacts comprising two raised contacts.

3. A three-dimensional piezoelectric force measuring device integrated in a main shaft as claimed in claim 1, characterized in that: The outer diameter surface of the piezoelectric sensor (6) is fixed to the upper connecting shell (31) via a plurality of force sensor fixing screws (13).

4. A three-dimensional piezoelectric force measuring device integrated in a main shaft as claimed in claim 1, characterized in that: The upper connecting shell (31) and the middle frame (32) are connected by means of sealant, and the middle frame (32) and the lower connecting shell (33) are connected by means of 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 materials.

5. A three-dimensional piezoelectric force measuring device integrated in a main shaft as claimed in claim 1, characterized in that: The head of the adapter tool handle (2) is a standard HSK interface, a cylindrical mating surface (22) is provided between the short conical surface (21) of the adapter tool handle (2) and the tool handle mating end surface (23), and the inner diameter surface of the piezoelectric sensor (6) is clearance-matched with the cylindrical mating surface (22) of the adapter tool handle (2).

6. A three-dimensional piezoelectric force measuring device integrated in a main shaft as claimed in claim 1, characterized in that: It also includes a power switch (14) and a magnetic charging port (15); the outer circumferential surface of the housing (3) is provided with a power switch (14) connected to the power supply circuit, and the bottom is provided with a magnetic charging port (15).

7. A three-dimensional piezoelectric force measuring device integrated into a main shaft as claimed in claim 1, characterized in that: The circuit carrier (9) comprises an upper circuit board and a lower circuit board, the upper circuit board and the lower circuit board are connected via 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, and the lower circuit board is fixed to the bottom of the lower connecting shell (33) via a circuit board fixing bolt (12).

8. A three-dimensional piezoelectric force measuring device integrated in a main shaft as claimed in claim 7, 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.

9. A three-dimensional piezoelectric force measuring device integrated in a main shaft as claimed in claim 1, characterized in that: The lower end surface of the main shaft (1) is provided with a threaded hole, and the upper connecting shell (31) is fixed to the main shaft by screwing a plurality of shell top mounting screws (7) into the threaded hole.

10. The three-dimensional piezoelectric force measuring device integrated in the main shaft according to claim 1, characterized in that: It also comprises a round nut (5) and a spring chuck (4). When installing the tool, after the tool is inserted into the adaptable tool handle (2), the round nut (5) is tightened to deform the spring chuck (4) to clamp the tool.

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