A torque sensor for a tightening machine
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2026-08-11
AI Technical Summary
[0003]主要是由于，拧紧机上的旋盖头通常采用永磁铁实现力矩控制，具有无需外部供电即可实现力矩控制的优点，但无法实时监测旋盖过程中扭矩的变化，而现有的扭矩传感器虽然可以实时监测扭矩的变化，但大多需要线缆来实现供电和数据传输
[0017]1、本实用新型的扭矩传感器中，电池安装在弹性体下方，直接向弹性体供电，扭矩传感器不对外出线，不需要通过外部导线连接，解决了拧紧机设备接线麻烦的问题，实现了电流的无线传输；
Smart Images
Figure CN224623889U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of torque measurement technology for tightening machines, and in particular to a torque sensor for tightening machines. Background Technology
[0002] With the rapid development of science and technology, sensors have penetrated into all areas of industrial production, such as the robotics industry, grinding industry, and various friction and wear testing machines, but their application in the tightening machine industry is relatively limited.
[0003] This is mainly because the capping head on the tightening machine usually uses a permanent magnet to achieve torque control, which has the advantage of achieving torque control without external power supply. However, it cannot monitor the change of torque in real time during the capping process. Although the existing torque sensors can monitor the change of torque in real time, most of them require cables to achieve power supply and data transmission. Utility Model Content
[0004] The technical problem to be solved by this utility model is that the torque sensor needs to be powered and the data transmitted through cables. Too many external cables will affect the connection between the torque sensor and the tightening machine.
[0005] To address the aforementioned technical problems, a torque sensor for tightening machines is proposed; this is achieved through the following technical solution:
[0006] A torque sensor for a tightening machine includes a battery, a PCB board, a housing, and an elastomer. One end of the elastomer is connected to the battery. The PCB board is located between the battery and the elastomer and integrates a WIFI chip. A groove is provided inside the end of the elastomer connected to the battery, and the PCB board is installed in the groove. The PCB board is connected to the battery. The elastomer includes a force-bearing platform, strain beams, strain gauges, and a hub. One end of the hub is connected to the battery, and the other end is connected to the force-bearing platform through four strain beams. Each strain beam has a strain gauge connected to its outer side. The strain gauges are connected to the PCB board, and the housing is fitted onto the position of the strain beams of the elastomer.
[0007] The battery is installed below the elastomer and supplies power directly to it without the need for external wires, thus solving the problem of complicated wiring in tightening machines. The deformation values of the elastomer detected by the strain beam and strain gauge are wirelessly transmitted through the PCB board, realizing wireless transmission of data and current.
[0008] In a preferred embodiment of the present invention, the battery is installed inside the battery casing, the battery casing is connected to the hub of the elastomer, a first wiring groove is provided on the battery casing, and the battery wires are connected to the PCB board through the first wiring groove. The battery directly supplies power to the elastomer through the internal wiring, without the need for external wiring.
[0009] In a preferred embodiment of the present invention, an AD acquisition chip is also integrated on the PCB board. The AD acquisition chip is integrated within the WIFI chip. The AD acquisition chip acquires elastomer data and transmits it wirelessly through the WIFI chip. The WIFI chip transmits the detection data of the elastomer received by the AD acquisition card. The real-time monitoring is achieved by transmitting the detection data of the elastomer received by the AD acquisition card through the WIFI chip.
[0010] In a preferred embodiment of the present invention, a circular slot is provided in the middle of the hub, and two second wiring slots are symmetrically arranged on both sides of the circular slot. The PCB board and four strain gauges are connected by wires, which pass through the second wiring slots. No external wiring is required, thus avoiding the interference of external wires on the installation of the torque sensor on the tightening machine.
[0011] In a preferred embodiment of the present invention, the strain gauge is a dual-grid strain gauge, each strain gauge containing two grids and eight grids, which are respectively represented as R1 to R8. The deformation of the strain gauge is monitored by the change of the grids.
[0012] In a preferred embodiment of the present invention, the eight wires are connected by wires to form a Wheatstone bridge that reflects torque changes. Each arm of the Wheatstone bridge includes two wire grids, which are respectively derived from two strain gauges. The deformation of the strain gauges is detected by the Wheatstone bridge, thereby detecting the torque change of the torque sensor.
[0013] In a preferred embodiment of the technical solution of the present invention, the strain gauge is a dual-grid strain gauge, and each strain beam has a square cross-section to ensure that it can deform under stress.
[0014] In a preferred embodiment of the technical solution of the present invention, the connection between the force table and the strain beam is provided with a thread for connecting the capping head on an external tightening machine, which facilitates the installation of the entire torque sensor on the tightening machine.
[0015] In a preferred embodiment of the present invention, the elastomer is in the form of a cylindrical vertical beam structure, which makes the diameter of the entire torque sensor small while ensuring that the torque sensor has a certain sensitivity and stiffness.
[0016] The advantages of this utility model compared with the prior art are:
[0017] 1. In the torque sensor of this utility model, the battery is installed below the elastic body and directly supplies power to the elastic body. The torque sensor does not have external wires and does not need to be connected through external wires, which solves the problem of complicated wiring of tightening machine equipment and realizes wireless transmission of current.
[0018] 2. In the torque sensor of this utility model, the deformation values of the strain beam and strain gauge of the elastic body are detected by the AD acquisition card on the PCB board and wirelessly transmitted to the computer via the WIFI chip, making it easier to observe the torque change of the tightening machine and realizing wireless data transmission.
[0019] 3. In the torque sensor of this utility model, the elastic body forms a column-shaped vertical beam structure, which makes the diameter of the entire torque sensor small, while ensuring that the torque sensor has a certain sensitivity and rigidity. Attached Figure Description
[0020] Figure 1 The figure shown is a three-dimensional structural schematic diagram of a torque sensor for a tightening machine according to this utility model;
[0021] Figure 2 The figure shown is an exploded structural diagram of a torque sensor for a tightening machine according to this utility model;
[0022] Figure 3 The figure shown is a schematic diagram of the elastic body structure of a torque sensor for a tightening machine according to this utility model;
[0023] Figure 4 The figure shown is a front view of the elastic body of a torque sensor for a tightening machine according to this utility model;
[0024] Figure 5 The image shown is a torque sensor for a tightening machine according to this utility model. Figure 3 A cross-sectional view of the AA plane;
[0025] Figure 6 The figure shown is a front view of the strain gauge installation of a torque sensor for a tightening machine according to this utility model;
[0026] Figure 7 The image shown is a torque sensor for a tightening machine according to this utility model. Figure 5 A cross-sectional view of the AA plane;
[0027] Figure 8 The diagram shown is a Wheatstone bridge of a torque sensor for a tightening machine according to this utility model.
[0028] Figure 9 The figure shown is a cross-sectional view of a torque sensor for a tightening machine according to this utility model;
[0029] Figure 10 The diagram shown is a schematic diagram of the strain gauge wire arrangement position of a torque sensor for a tightening machine according to this utility model;
[0030] Figure 11 The figure shown is the equivalent stress cloud diagram calculated by ANSYS Workbench for a torque sensor for a tightening machine according to this utility model;
[0031] Figure 12 The figure shown is a total deformation cloud diagram calculated by ANSYS Workbench for a torque sensor for a tightening machine according to this utility model.
[0032] Explanation of reference numerals in the attached diagram: 1. Battery; 2. PCB board; 3. Elastomer; 4. Housing; 5. Force platform; 6. Strain beam; 7. Strain gauge; 8. Hub; 10. First wiring channel; 11. Battery casing; 12. Second wiring channel; 13. First strain beam; 14. Second strain beam; 15. Third strain beam; 17. Fourth strain beam. Detailed Implementation
[0033] The following will refer to the appendix in the embodiments of this utility model. Figures 1-12 The technical solutions in the embodiments of this utility model will be described in detail below.
[0034] like Figures 1-4 As shown, a torque sensor for a tightening machine includes a battery 1, a PCB board 2, a housing 4, and an elastomer 3.
[0035] like Figure 2 As shown, battery 1 and elastomer 3 are fixedly connected by screws, enabling internal power supply to the torque sensor without the need for external wires to connect to the power source, thus reducing the impact on the tightening machine during tightening operations.
[0036] like Figure 2 As shown, the end of the elastomer 3 connected to the battery 1 has a groove inside, and the PCB board 2 is glued inside the groove. The PCB board 2 is connected to the battery 1 by wires. The PCB board 2 integrates a WIFI chip for transmitting wireless signals and an AD acquisition chip for collecting data from the elastomer 3. The AD acquisition chip is integrated inside the WIFI chip on the PCB board 2.
[0037] like Figure 2 , Figure 3 and Figure 9 As shown, the elastic body 3 includes a force-bearing platform 5, a strain beam 6, a strain gauge 7, and a hub 8. A battery 1 is provided at one end of the hub 8. The battery 1 is attached to the inside of the battery casing 11. The battery casing 11 is connected to one end of the hub 8 by screws. A first wiring groove 10 is opened on the battery casing 11. The wires of the battery 1 pass through the first wiring groove 10 and are connected to the PCB board 2, ensuring that the wires are installed neatly, reducing the wire installation space, and thus reducing the overall volume of the battery 1.
[0038] like Figure 1 and Figure 2 As shown, the battery casing 11 is a cylinder, the PCB board 2 has a circular cross-section, the hub 8 of the elastic body 3 is a cylindrical shell, and the elastic body 3 is a column-type vertical beam structure.
[0039] In this embodiment, because a column-type vertical beam structure is used, a torque sensor with a small diameter is formed. The torque sensor has an external diameter φ of 30mm, a height x of 75.5mm, and a range of 10Nm. While the torque sensor has a small diameter, it also ensures that the torque sensor has a certain sensitivity and rigidity.
[0040] The outer surface of the battery casing 11 is provided with a charging port for the battery 1, which can charge the battery 1 when the tightening machine is not used, ensuring the normal use of the torque sensor.
[0041] A battery 1 is installed inside the torque sensor, enabling the torque sensor to be internally powered without the need for an external power cord, thus avoiding the possibility that an external power cord might affect the operation of the tightening machine.
[0042] like Figure 2 and Figure 3 As shown, the PCB board 2 is installed in a groove inside the end of the hub 8 near the battery 1. The PCB board 2 is pasted inside the groove. The other end of the hub 8 is welded to one end of the four strain beams 6. The other end of the four strain beams 6 is welded to the force platform 5. A strain gauge 7 is pasted in the middle of the outer side of each strain beam 6. The strain gauge 7 is connected to the PCB board 2.
[0043] like Figure 1 and Figure 3 As shown, in this embodiment, there are four strain beams 6, each with a square cross-section. One end of the hub 8 is connected to the outer shell 4 via a thread. The outer shell 4 is fitted over the outside of the strain beam 6 to protect it.
[0044] The PCB board 2 is connected to the four strain gauges 7 by wires. A circular slot is opened in the middle of the hub 8. Two second wiring slots 12 are symmetrically arranged on both sides of the circular slot on the hub 8. The wires pass through the second wiring slots 12 to avoid external wiring affecting the installation of the torque sensor.
[0045] The AD acquisition chip on PCB board 2 acquires the resistance data of strain gauge 7 after deformation and transmits it wirelessly to the host computer via WIFI chip.
[0046] PCB board 2 also has a function to set the acquisition threshold. When the torque is lower than the threshold, no data is collected. The default value of the threshold is 0.5Nm. That is, when the torque value received by the torque sensor is lower than 0.5Nm, PCB board 2 does not collect data or generate data. At this time, the WIFI chip is in sleep mode, which can reduce the power consumption of the torque sensor and improve the battery life of the torque sensor. The torque sensor threshold can be set through the host computer software.
[0047] The bottom of the force-bearing platform 5 is connected by an external thread to a capping head for clamping the item to be tightened, which makes it easy to install a torque sensor on the tightening machine and to allow the torque sensor to monitor the torque of the capping head of the tightening machine in real time.
[0048] like Figure 7 and Figure 8As shown, strain gauge 7 is a dual-grid strain gauge. Each strain gauge 7 contains two wire grids for measuring torque. The eight wire grids are represented as R1 to R8. Four strain gauges 7 are connected by wires to form a Wheatstone bridge. Each arm of the Wheatstone bridge includes one wire grid of two different strain gauges 7. The deformation of the strain gauge 7 is detected by the Wheatstone bridge, thereby detecting the torque change of the torque sensor.
[0049] like Figure 5 and Figure 8 As shown, in this embodiment, the four strain beams 6 are respectively labeled as the first strain beam 13, the second strain beam 14, the third strain beam 15, and the fourth strain beam 17. The wire grids of the strain gauges 7 on the four strain beams 6 are as follows in the Wheatstone bridge: the two wire grids of the strain gauge 7 of the first strain beam 13 are R1 and R2, the two wire grids of the strain gauge 7 of the second strain beam 14 are R3 and R4, the two wire grids of the strain gauge 7 of the third strain beam 15 are R5 and R6, and the two wire grids of the strain gauge 7 of the fourth strain beam 17 are R7 and R8.
[0050] The strain gauge 7 has four positioning marks b, f, d, and h. Positioning marks b and f are the positioning center lines, and positioning marks d and h are the positioning lines of the wire grids, which facilitates the determination of the installation position of the strain gauge 7. In this embodiment, the two wire grids on the strain gauge 7 are defined as wire grid i and wire grid j. Wire grid i and wire grid j are distributed at 90° on both sides of the center line of the strain gauge 7 and pass through the positioning marks. The solder joints of wire grid i are a and g, and the solder joints of wire grid j are c and e, which ensures the stability of wire grid i and wire grid j as a resistive connection in the entire Wheatstone bridge.
[0051] The wire grids in the strain gauge 7 on the first strain beam 13 are R1 and R2, the wire grids in the strain gauge 7 on the second strain beam 14 are R3 and R4, the wire grids in the strain gauge 7 on the third strain beam 15 are R5 and R6, and the wire grids in the strain gauge 7 on the fourth strain beam 17 are R7 and R8.
[0052] In this embodiment, the computer receives the WIFI chip signal through a receiver. The computer receiver is existing technology and is already in use in daily life.
[0053] like Figures 11-12 As shown, in this embodiment, the torque sensor of the tightening machine was simulated using ANSYS Workbench. Finite element analysis of the elastomer 3 was performed using ANSYS Workbench, and the stiffness was 1.2965x104 Nm / rad, with a maximum equivalent stress of 165.32 MPa, which is much smaller than the yield strength (1200 MPa) of the elastomer material (40CrnimoA). The overload capacity exceeds 500%.
[0054] like Figure 11As shown, the simulation process of the torque sensor for the tightening machine using ANSYS Workbench is as follows:
[0055] First, set the boundary conditions: apply a torque of 10 Nm to the force platform 5.
[0056] Next, perform calculations: Submit the calculation model to the WorKbench software for calculation.
[0057] Finally, the calculation results show that the maximum equivalent stress of the sensor is 165.32 MPa and the stiffness is 1.2965 x 10⁴ Nm / rad.
[0058] The sensor is mounted on the capping head assembly, and the strain gauges 7 are connected by wires to form a Wheatstone bridge to ensure that the deformation of the four strain beams 6 can be detected. The Wheatstone bridge reflects the torque change, thereby improving the accuracy of the sensor's detection data. The sensor is installed in the capping head, and a fixed torque is applied to the capping head by a servo motor. The fixed torque is transmitted to the sensor through the capping head. The force on the sensor causes the strain beam 6 to deform, which in turn causes the strain gauges 7 to deform. The voltage value at the output terminal of the Wheatstone bridge is calculated based on the resistance value of the strain gauges 7 after deformation.
[0059] The method for calculating the voltage value at the output terminal of a Wheatstone bridge is as follows:
[0060] —This indicates the output voltage value in the Fx direction when Fx is fully loaded;
[0061] — This represents the sensitivity coefficient of the strain gauge. In calculations, the average value is usually taken, with k=2.
[0062] —These represent the strain measured in patch regions R1 to R8, respectively;
[0063] —This represents the excitation voltage of the bridge circuit, which is taken here. .
[0064] ;
[0065] The sensor's detection values are transmitted to the computer via the wireless PCB board 2. By attaching strain gauges 7 to the sensor to form a Wheatstone bridge, the sensitivity and stiffness of the sensor can be detected simultaneously. The torque changes of the tightening machine can be observed more conveniently through the computer.
[0066] like Figure 12As shown, when a torque of 10 Nm is applied to the sensor, the first strain beam 13, the second strain beam 14, the third strain beam 15, and the fourth strain beam 17 deform. R1, R3, R5, and R7 are subjected to tensile strain, while R2, R4, R6, and R8 are subjected to compressive strain. Static simulation of the elastic body 3 is performed using Workbench software. The simulation calculation shows that the equivalent stress of the elastic body 3 is 165.32 MPa, and the deformation is 0.011577 mm. The strain in the R1 patch area is... The strain of the R2 patch area is The strain of the R3 patch area is The strain of the R4 patch area is The strain of the R5 patch area is The strain of the R6 patch area is The strain of the R7 patch area is The strain of the R8 patch area is , will be composed of Figure 8 In the Wheatstone bridge, then:
[0067] The sensitivity is then: .
[0068] Therefore, the sensor of this invention has high accuracy, rigidity and sensitivity.
[0069] The above embodiments are only for illustrating the technical concept of this utility model and should not be construed as limiting the scope of protection of this utility model. Any modifications made to the technical solution based on the technical concept proposed by this utility model shall fall within the scope of protection of this utility model.
Claims
1. A torque sensor for a tightening machine, characterized in that: Includes a battery (1), a PCB board (2), a shell (4) and an elastomer (3). One end of the elastomer (3) is connected to the battery (1). The PCB board (2) is located between the battery (1) and the elastomer (3). The PCB board (2) integrates a WIFI chip. The end of the elastomer (3) connected to the battery (1) has a groove inside. The PCB board (2) is installed in the groove and connected to the battery (1). The elastic body (3) includes a force-bearing platform (5), strain beams (6), strain gauges (7) and a hub (8). One end of the hub (8) is connected to the battery (1), and the other end is connected to the force-bearing platform (5) through four strain beams (6). Each strain beam (6) has a strain gauge (7) connected to its outer side. The strain gauge (7) is connected to the PCB board (2). The outer shell (4) is fitted onto the position of the strain beams (6) of the elastic body (3).
2. The torque sensor for a tightening machine according to claim 1, characterized in that: The battery (1) is installed inside the battery (1) shell. The battery (1) shell is connected to the hub (8) of the elastomer (3). A first wiring groove (10) is opened on the battery (1) shell. The wires of the battery (1) are connected to the PCB board (2) through the first wiring groove (10).
3. The torque sensor for a tightening machine according to claim 2, characterized in that: The PCB board (2) also integrates an AD acquisition chip, which is integrated into the WIFI chip. The AD acquisition chip collects data from the elastomer (3) and transmits it wirelessly through the WIFI chip.
4. The torque sensor for a tightening machine according to claim 1, characterized in that: A circular slot is provided in the middle of the hub (8). Two second wiring slots (12) are symmetrically arranged on both sides of the circular slot on the hub (8). The PCB board (2) and four strain gauges (7) are connected by wires, and the wires pass through the second wiring slots (12).
5. The torque sensor for a tightening machine according to claim 1, characterized in that: The strain gauge (7) is a double-grid strain gauge (7), each strain gauge (7) contains two grids, and the eight grids are represented as R1~R8 respectively.
6. The torque sensor for a tightening machine according to claim 1, characterized in that: The eight wires are connected by wires to form a Wheatstone bridge that reflects the change in torque. Each arm of the Wheatstone bridge includes two wire grids, which are respectively from two strain gauges (7).
7. The torque sensor for a tightening machine according to claim 1, characterized in that: Each strain beam (6) has a square cross-section.
8. The torque sensor for a tightening machine according to claim 1, characterized in that: The connection between the force-bearing platform (5) and the strain beam (6) is provided with a thread for connecting the capping head on an external tightening machine.
9. The torque sensor for a tightening machine according to claim 1, characterized in that: The elastomer (3) has a cylindrical vertical beam structure.