Bolt tightening force sensor for bolt locking operations

Abstract

The present invention provides a bolt clamping force sensor for bolt locking operations. When locking a spiral fastener, the torque shaft in the clamping force sensor is driven to generate an axial force at one end of the spiral mechanism, a deformation sensing value caused by an extrusion force sensing module, and a clamping force generated by a sleeve driven by the other end of the torque shaft to lock a spiral fastener of a specific specification. The parameter relationship between the two is pre-calibrated with a standard axial force meter to serve as a basis for calculating and controlling the clamping force during the locking process. The clamping force sensor for the spiral fastener of the present invention can be applied to various industries. When it is sleeved on various torque tools to perform a spiral fastener locking operation, a spiral fastener of a specific specification can be effectively sensed to control the accuracy of the clamping force (clamping force) acting on the spiral fastener, so as to improve the quality of the spiral fastener (bolted joint).

Description

Technical Field

[0001] The present invention relates to a bolt clamping force sensor for bolt locking operations, and in particular to a device which can directly sense the clamping force acting on a spiral fastener and transmit the sensed data when used in the process of locking a spiral fastener. Background Art

[0002] Tightening bolts with torque wrenches has been widely used in the assembly of various products. Applying torque is a means, but the purpose is to tighten the bolts. The best and most difficult thing is how to tighten each bolt to the same tightness, especially for high-pressure containers, engine cylinders or vacuum equipment. Precision tightening operations that require controlling the clamping force of the bolts are important issues of concern to the industry, but it is always difficult to achieve by controlling the tightening torque alone.

[0003] In the process of tightening bolts, only 10% of the torque is converted into clamping force. There is a popular saying called the "541" rule, that is, in the process of tightening the bolt, about 50% of the torque is used to overcome the friction between the bolt head or nut and the mating surface, and about 40% of the torque needs to overcome the friction in the thread, and the torque that can actually be converted into the bolt clamping force is only about 10%. The size of the final clamping force is affected by various factors related to the spiral fastener, such as the condition of the bolt and the fastener to be fastened (hardness of the material, processing accuracy and surface roughness, oil stains, rust or bruises, etc.) and the hardness of the washers used, so that the preload force of the bolt is difficult to control. Although there are many calculation formulas and calculation parameters for torque and clamping force in academia or engineering manuals, it is always difficult to get correct verification. For the industry that needs to control the tightening force, there is still no economical and effective method to accurately understand how much clamping force will be generated on the spiral fastener by the torque applied to the spiral fastener, let alone how to effectively control it. This does pose many quality risks and uncertainties for precision assembly operations that require controlled uniform clamping force.

[0004] To date, the industry generally uses various torque controllers, digital display torque wrenches, sound-type torque wrenches or electric servo control torque tools to control the locking torque. However, using the traditional torque control method, for example, applying the same torque to tighten bolts of the same specification, the only difference is the surface condition of the thread, such as normal, oily, rusty or damaged bolts, or even just changing the hardness of the gasket. Although the displayed torque control accuracy is within 5%, experiments have shown that the actual clamping force values ​​measured can vary by up to nearly 50%.

[0005] At present, the most accurate method for controlling the tightening force of bolts is the bolt tension detector using ultrasonic sensing technology. However, its production and construction costs are high, and it has always been difficult to popularize. In addition, the induction bolt with the ability to sense the clamping force of the bolt (a deformation sensing component is pasted at the appropriate position of the bolt axis to detect its clamping force) is also limited by the high price and the fact that it can only be locked with an open wrench, which makes construction inconvenient and inefficient and difficult to popularize. The control and detection of the tightening force of the bolt can also use axial force sensing devices such as bolt pressure sensors (Bolt Transducer) or through-hole type load cell micro force sensors (Center-holetype Compression Load Cell) or piezoelectric sensing rings as alternatives. However, in actual applications, the production costs and ease of use of the above solutions are the main reasons why they are difficult to popularize in the industry. Summary of the invention

[0006] After careful research, the inventor has developed a clamping force sensor for bolt locking operations, which can be used in the tightening operations of various torque tools. It can know the clamping force generated by the applied torque on the spiral fastener in real time, and continuously transmit the result to the control device or display device in a wired or wireless manner to record or upload the data to meet the development needs of the industrial trend of Industry 4.0. The clamping force sensor for the spiral fastener of the present invention can not only effectively improve the tightening accuracy, but also has the advantages of low cost and convenient operation, which greatly enhances the effective utilization of the industry.

[0007] The purpose of the present invention is to provide a device that can directly measure the clamping force acting on the spiral fastener during the process of locking the spiral fastener. It is a clamping force sensor (Force Transducer) that can be attached to various traditional manual, pneumatic or electric torque wrenches (TorqueWrench) or screwdrivers (Screwdriver). The clamping force sensor for bolt tightening operations of the present invention allows the torque tool to become a clamping force wrench (Force Wrench) or clamping force screwdriver (Force Screwdriver) that can directly control the clamping force. During the locking process, the clamping force acting on the spiral fastener is detected in real time. It is not only a major change and breakthrough in the locking technology of spiral fasteners, but also will subvert the traditional technical means of controlling the locking torque, so that the tightening of spiral fasteners can more accurately achieve the required clamping force, without the need to use expensive and inconvenient ultrasonic and axial force detection technology to control the clamping force of spiral fasteners. The clamping force sensor for bolt tightening operation of the present invention elevates the technology of spiral fastener locking to the highest level, and can directly control the clamping force of the spiral fastener instead of the traditional torque control, thus providing the industry with the best solution for spiral fastener locking.

[0008] The present invention provides a clamping force sensor for bolt locking operation, which comprises: a sensor body, one end of which is a torque tool receiving portion to match the size of the output end of the torque tool, and the other end is machined into a screw hole with a spiral guide groove to lock into the spiral guide groove of a torque shaft; the torque shaft, when tightened by a spiral mechanism at one end, generates an axial force to squeeze a force sensing module, and at the same time, drives a sleeve with an output square head at the other end to lock a spiral fastener of a specific specification; a plurality of steel balls, which are filled between the spiral guide groove of the sensor body and the spiral guide groove of the torque shaft; a force sensing module, which is arranged at the bottom of the screw hole in the sensor body The force sensing module comprises a sensing ring body and a force sensing component, the outer edge of the sensing ring body comprises a ring groove, and the force sensing component is attached to the bottom of the ring groove to measure the deformation sensing value generated by the axial force of the sensing ring body; a dust plug is arranged between the force sensing module and the torque shaft, and the dust plug has a leak-proof ring; a signal processing module is arranged at a fixed seat inside or outside the sensor body, and is electrically connected to the force sensing component, and the signal processing module comprises a signal amplifier, a microprocessor, a power circuit unit, a signal transmission unit, a gyroscope, a memory unit, an input / output module, a transmission antenna and a warning unit. The signal amplifier amplifies the deformation sensing value of the force sensing component into a digital signal; the microprocessor then calculates the corresponding clamping force value with preset parameters; the power circuit unit is used to convert the externally supplied power into the power required by the signal processing module; the signal transmission unit can be a wireless communication module such as RF, Bluetooth, WiFi or ZigBee, or a wired RS232, RS485 or UART to transmit signals to the control or display device; the input and output module can be USB for battery charging and firmware update; the gyroscope is used to detect the rotation angle displacement of the sensor body; the memory unit stores the deformation sensing value of the force sensing module and the clamping force parameters obtained by calibrating the screw fasteners of specific specifications with a standard axial force gauge ; The input / output module transmits the clamping force value to the control device or display device in a wired or wireless manner; the transmission antenna transmits the information processed by the sensing operation to the control device; the warning unit prompts the use status of the sensor with lights or sounds, such as pairing, signal transmission or power supply abnormality; the power module is a rechargeable power supply, electrically connected to the signal processing module; the fixing seat is lined with a cushion and fastened to the sensor body, accommodating the signal processing module and the power module respectively coated with elastic materials, and the periphery is coated with a protective cover; the protective cover is made of a material that does not block the transmission of wireless signals; and a fixing ring is arranged at the outlet end of the screw hole of the sensor body to prevent the torque shaft from detaching when it slides back and forth in the screw hole of the sensor body.

[0009] Thus, when torque is applied to the clamping force sensor of the present invention, the torque shaft in the clamping force sensor is driven, so that the spiral guide groove at one end thereof rotates and advances along the spiral guide groove in the screw hole of the sensor body to generate an axial force, which squeezes the deformation sensing value generated by the force sensing module at the bottom of the screw hole and the sleeve driven by the other end of the torque shaft, and the clamping force generated by locking the spiral fastener of a specific specification is obtained by pre-calibrating the parameter relationship between the two with a standard axial force meter, which serves as a basis for calculating and controlling the clamping force during the locking process. The spiral fastener of a specific specification refers to the size of the bolt to be locked, the pitch size, the surface condition (such as the machining dimensional accuracy, roughness or lubrication degree) and the hardness of the gasket used. With this parameter relationship, the operator can use the clamping force sensor of the present invention to pair with the control device or display device, and input the specifications of the spiral fastener to be tightened (bolt grade, pitch and pitch diameter, etc.) and the hardness of the gasket as well as the target clamping force desired to be locked. Then apply torque to drive the clamping force sensor of the present invention. During the locking process, the signal processing module calculates the corresponding clamping force value in real time based on the deformation sensing value received from the force sensing module and the parameter relationship pre-checked for the spiral fastener, and transmits it to the control device or display device in a wired or wireless manner. When the target clamping force is locked, the control device cuts off the power source of the torque tool in real time or the display device prompts the operator to stop applying torque with sound or light, which serves as a basis for detecting and controlling the clamping force of the spiral fastener. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a combined cross-sectional schematic diagram of the bolt clamping force sensor of the present invention;

[0011] Figure 2 It is an exploded schematic diagram of the bolt clamping force sensor of the present invention;

[0012] Figure 3 It is a schematic diagram of the combined appearance of the bolt clamping force sensor of the present invention;

[0013] Figure 4A The application diagram of the bolt clamping force sensor of the present invention is shown in FIG. Figure 1 ;

[0014] Figure 4B The application diagram of the bolt clamping force sensor of the present invention is shown in FIG. Figure 2 ;

[0015] Figure 5 for Figure 4B Explosion diagram of

[0016] Fig. 6A is a cross-sectional schematic diagram of a bolt clamping force sensor of the present invention;

[0017] Figure 6B It is a schematic diagram of the lead angle calculation of the bolt clamping force sensor of the present invention;

[0018] Fig. 7A It is a schematic diagram of the combined appearance of the locking spiral fastener of the bolt clamping force sensor of the present invention;

[0019] Figure 7B It is a schematic diagram of the combined cross-section of the locking spiral fastener of the bolt clamping force sensor of the present invention;

[0020] Fig. 8A It is a partial schematic diagram of the parameter verification structure of the bolt clamping force sensor of the present invention;

[0021] Figure 8B It is an overall schematic diagram of the parameter verification structure of the bolt clamping force sensor of the present invention;

[0022] Fig. 9 Schematic diagram of various torque tools applicable to the bolt clamping force sensor of the present invention;

[0023] Fig.10 It is a schematic diagram of the application operating system of the bolt clamping force sensor of the present invention.

[0024]

Explanation of symbols

[0025] 1 Clamping force sensor

[0026] 11 Sensor body

[0027] 111 Torque tool receiving part

[0028] 112 Screw holes

[0029] 1121 Spiral guide groove

[0030] 113 Buffer pad holder

[0031] 12 Cushion

[0032] 13 Torque shaft

[0033] 131 output end

[0034] 132 Spiral guide groove

[0035] 14 Steel Balls

[0036] 15 Dust plug

[0037] 151 Leakage-proof ring

[0038] 16 Force Sensing Module

[0039] 161 Induction ring body

[0040] 162 Force Sensing Components

[0041] 163 Ring groove

[0042] 17 Fixing ring

[0043] 181 Fixed seat

[0044] 182 Fixed seat

[0045] 191 Protective Case

[0046] 192 Protective Case

[0047] 20 Signal Processing Module

[0048] 21 Power module

[0049] 22 Bearings

[0050] 23 Steering gear

[0051] 24 Steering gear

[0052] 25 Output shaft

[0053] 26 Bearings

[0054] 27 Fixing ring

[0055] 8 Screw fasteners

[0056] 81 Bolt

[0057] 82 Washer

[0058] 83 Nut

[0059] 84 Locked firmware

[0060] 9 Standard axial force gauge

[0061] 10 Sleeve

[0062] 90 Test socket DETAILED DESCRIPTION

[0063] In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail through the following specific embodiments and the accompanying drawings, as follows:

[0064] Please refer to Figures 1 to 3 , Fig. 6A and Figure 6B , FIG. 7A to FIG. 7B and Fig. 8A and Figure 8BAs shown in the figure, the clamping force sensor 1 of the present invention comprises a sensor body 11, a force sensing module 16, a dust plug 15, a torque shaft 13, a steel ball 14, a signal processing module 20, a power module 21, a buffer pad 12, a fixing seat 181, 182, a protective cover 191, 192 and a fixing ring 17. One end of the sensor body 11 is a torque tool receiving portion 111, which is used to match the size of the torque tool output end, and the other end of the sensor body 11 is machined into a screw hole 112 with a spiral guide groove 1121 for locking into the spiral guide groove 132 of the torque shaft 13. The force sensing module 16 is disposed at the bottom of the screw hole 112 of the sensor body 11. The force sensing module 16 has a sensing ring body 161 and a force sensing component 162. The outer edge of the sensing ring body 161 has an annular groove 163. The force sensing component 162 is attached to the bottom of the annular groove 163 to measure the deformation sensing value of the sensing ring body 161 caused by the axial force and generate a deformation sensing signal. The force sensing component 162 is electrically connected to the signal processing module 20. The sensing ring body 161 is fixed by a mechanism to prevent the sensing ring body 161 from rotating or falling off. In addition, the force sensing module 16 can be made of various sensing components that can sense axial force, such as strain gauges or piezoelectrics. The dust plug 15 is disposed between the force sensing module 16 and the torque shaft 13 and has a leak-proof ring 151 to prevent foreign matter from entering the force sensing module 16. A spiral guide groove 132 is formed along the axial diameter of one end of the torque shaft 13, and a plurality of steel balls 14 are filled between the spiral guide groove 1121 of the sensor body 11, so that when the torque shaft 13 is twisted, it can slide axially along the spiral guide groove 1121 in the screw hole 112 of the sensor body 11, effectively reducing the friction resistance during rotation. The generated axial thrust acts on the end surface of the dust plug 15 and the end surface of the force sensing module 16. The output square head 131 at the other end of the torque shaft 13 is made to be compatible with the sleeve 10 (such as Figure 8BThe torque shaft 13 is assembled with the sensor body 11 and fixed in the ring groove at the outlet end of the screw hole 112 of the sensor body 11 by the fixing ring 17, so that the torque shaft 13 slides in the screw hole 112 of the sensor body 11 to prevent it from falling off. The fixing seats 181, 182 use the buffer pad 12 and are locked to the buffer pad support seat 113 of the sensor body 11 to accommodate the signal processing module 20 and the power module 21. The signal processing module 20 has a microprocessor, a signal amplifier, a pairing key switch, a power circuit unit, a signal transmission unit, a gyroscope, a memory unit, an input / output module, a transmission antenna and an alarm unit, and is electrically connected to the force sensing component 162. The signal amplifier of the signal processing module 20 amplifies the sensing signal received from the force sensing component 162 and converts it into a digital signal, and then the microprocessor calculates the corresponding clamping force value with the pre-calibrated parameters, and transmits it to the control device or display device through the input / output module and the transmission antenna. The signal processing module 20 is coated with elastic material and placed on the fixed seat 181. The power circuit unit is used to convert the externally supplied power into the power required by the power module 21; the gyroscope detects the rotation angle displacement of the sensor body 11, and the memory unit memorizes and verifies the clamping force parameters obtained by verifying the deformation sensing values ​​of the screw fastener 8 to be locked and the force sensing module 16 with the standard axial force meter 9 (as shown in Figure 8). In addition, the verified parameters can also be stored in the memory unit of the control device or display device to facilitate the operator to enter the specifications of the screw fastener to be locked after power-on pairing to obtain the corresponding parameters. Furthermore, if the measured data is different due to the difference between the specifications of the screw fastener used and the gasket used for verification, it can be corrected by the program. The power module 21 is a rechargeable battery and is coated with elastic material, placed on the fixed seat 182, and electrically connected to the signal processing module 20. The protective covers 191 and 192 are made of materials that do not block wireless signal transmission, and cover the signal processing module 20 and the power module 21 in the fixing seat to protect the signal processing module 20 and the power module 21. The signal transmission unit can be a wireless communication module, such as RF, Bluetooth, WiFi or ZigBee, or a wired RS232, RS485 or UART, etc. The input and output module can be a USB for battery charging and firmware update. The warning unit can be a buzzer or an LED light to indicate the signal strength, power status, use status, etc. The connecting line can electrically connect the force sensing component 162 of the force sensing module 16 and the signal processing module 20.

[0065] Before using the clamping force sensor 1 of the present invention, the operator needs to lock the clamping force sensor 1 and the spiral fastener 8 to be locked on the standard axial force meter 9 for calibration in advance, so as to establish a parameter relationship between the deformation sensing value of the force sensing module 16 and the clamping force of the spiral fastener of the specific specification. In addition, the generation of the clamping force and the deformation sensing value of the force sensing module 16 can be in a linear relationship, thereby making the control of the clamping force easier and more accurate. Furthermore, if there is no standard axial force meter to calibrate the spiral fastener to be locked or if it is customary to lock it with a target torque, the clamping force value displayed when locked to the target torque can also be used as a reference target value for controlling the clamping force of subsequent spiral fasteners of the same specification. In this way, the purpose of controlling uniform clamping force can still be achieved.

[0066] When the clamping force sensor 1 of the present invention is used for locking operations, the operator only needs to pair the clamping force sensor 1 with the control device or display device, input the specifications of the spiral fastener 8 to be tightened, the target clamping force and the control accuracy, and then use the torque tool to apply torque to the clamping force sensor 1 to lock the spiral fastener 8. During the locking process, one end of the torque shaft 13 of the clamping force sensor 1 generates an axial thrust to the dust plug 15 through the spiral mechanism formed by its spiral guide groove 132 and the spiral guide groove 1121 of the screw hole 112 of the sensor body 11 to squeeze the end face of the force sensing module 16, so that the force sensing module 16 is deformed, and at the same time, the other end of the torque shaft 13 locks the spiral fastener 8 to generate a clamping force. The deformation sensing value generated by the clamping force and the force sensing module 16 has a certain parameter relationship with the locked spiral fastener 8. The signal processing module 20 will continuously calculate the clamping force acting on the spiral fastener 8 based on the parameter relationship between the deformation sensing value of the force sensing module 16 obtained in advance and the clamping force corresponding to the spiral fastener 8 of the specific specification. When the target clamping force is reached, the control device of the torque tool will cut off the power source or the display device will prompt the operator to stop the operation and determine whether it is qualified or not by sound or light. When the applied torque disappears, the torque shaft 13 can reduce the rebound resistance to a minimum through the rigid rebound force of the sensing ring body 161 and the dust plug 15, and the large pitch and large lead angle formed by the multi-helix design of the torque shaft 13, so that the torque shaft 13 returns to its state when no force is applied, and the deformation sensing value of the force sensing module 16 returns to zero.

[0067] Furthermore, when the clamping force sensor 1 of the present invention is used in a pneumatic, electric or hydraulic power tightening tool, before it is locked to the target clamping force, the control mechanism of the tool is used to slow down the locking speed of the tool, and intermittent tapping is used to gradually lock it to the target clamping force, thereby effectively improving the control accuracy of the clamping force.

[0068] Please refer to Figure 4A and Figure 4B , Figure 5 , Fig. 6A and Figure 6B and Fig. 8A and Figure 8B As shown in the figure, the clamping force sensor 1 of the present invention can be applied to a torque tool with a steering gear 23, 24 transmission in a built-in manner. The output end of the motor reduction mechanism of the torque tool can be inserted into the torque tool receiving portion 111 of the sensor body 11 of the clamping force sensor 1. When torque is applied to the clamping force sensor 1, the output end 131 of the torque shaft 13 of the clamping force sensor 1 passes through the bearing 22 to insert into the steering gear 23 to drive another meshing steering gear 24, and the output shaft 25 of the steering gear 24 then passes through another bearing 26 and is fixed by a fixing ring 27, so that the output shaft 25 is inserted into the sleeve 10 to lock the spiral fastener 8, and the spiral fastener 8 may include a bolt 81, a washer 82, a fastener 84 and a nut 83. Figure 4A and Figure 4B and Figure 5 The principle and Figures 1 to 3 The principle is the same as that of the embodiment. When applying torque to the clamping force sensor 1, the spiral mechanisms with different pitches at both ends of the rotating shaft 13 are driven simultaneously. That is, the deformation sensing value generated by the axial thrust FSW generated by the spiral guide groove 132 along the spiral guide groove 1121 of the sensor body 11 to the force sensing module 16, and the other end to the locked spiral fastener 8 (such as Fig. 6A and Figure 6B The clamping force F generated by B&W , with standard axial force meter 9 (such as Fig. 8A and Figure 8B As shown in the figure, the axial thrust FSW and the clamping force F corresponding to the deformation sensing value are pre-calibrated and established. B&W The parameter relationship is then used as a basis for detecting and controlling the clamping force of the screw fastener 8. When the torque is applied, the thrust generated by the rotating mechanism can be calculated using the following formula:

[0069] F a =2×π×η×T / (R×10 -3 )

[0070] Among them, F a is the thrust FSW or clamping force F B&W , in N; T is the applied torque, in Nm; R is the lead of the screw, in mm; η is the mechanical efficiency;

[0071] A is the thrust FSW generated by the torque shaft on the force sensing module when a torque of 500Nm is applied to the bolt + washer of the clamping force sensor - M20, P-2.0. The calculation formula is as follows:

[0072] FSW=2×3.1416×0.95×500 / (250×10 -3)=11,983(N)

[0073] The force sensing module withstands a thrust of 11,983N.

[0074] B is the clamping force F generated by applying a torque of 500Nm to the clamping force sensor to lock the bolt + washer of M20, P-2.0 B&W The calculation formula is as follows:

[0075] F B&W =2×3.1416×0.1×500 / (2×10 -3 )=188,496(N)

[0076] The screw fastener (M20, P-2.0 bolt + washer) withstands a clamping force of 188,496N.

[0077] Please refer to Fig. 6A and Figure 6B and FIG. 7A to FIG. 7B ,like Fig. 6A and Figure 6B As shown, the spiral guide groove 132 of the torque shaft 13 and the spiral guide groove 1121 in the screw hole 112 of the sensor body 11 are made with a thread pitch diameter of 46mm, a pitch of 50mm, and a number of spirals of 5, and the lead angle is calculated to be 59.97°, while the spiral fastener 8 fastened to the other end of the torque shaft 13 is M20, with a pitch of 2mm, and a lead angle of a single spiral is 2.03°. FIG. 7A to FIG. 7B As shown, a torque of 500 Nm is applied to the clamping force sensor 1 so that the torque shaft 13 tightens the M20 screw fastener 8 to generate a clamping force F of 188,496 N. B&W At the same time, the spiral guide groove 132 with a spiral number of 5 at the other end generates an axial thrust FSW of 11,938N on the dust plug 15 and the force sensing module 16 along the spiral guide groove 1121 in the screw hole 112 of the sensor body 11. The deformation caused by the axial thrust FSW of 628.32N squeezing the dust plug 15 and the sensing ring body 161 is designed to be within the yield strength range of the dust plug 15 and the sensing ring body 161. The efficiency η used in calculating the thrust with torque is an estimated value, which does not affect the conversion parameters of the actual deformation value of the force sensing module and the clamping force acting on the spiral fastener 8 measured by the standard axial force meter 9. In addition, if Fig. 6A and Figure 6BAs shown, the lead angle of the spiral guide groove 132 of the torque shaft 13 is designed to be 59.97°, which is greater than its friction angle (taking the present invention as an example, the spiral guide groove 1121 of the sensor body 11 and the spiral guide groove 132 of the torque shaft 13 are made into 5 spirals to increase the pitch and increase the lead angle, effectively reducing the axial force acting on the force sensing module 16. The spiral guide groove is filled with a plurality of steel balls 14 and lubricating grease, just like the design of a ball screw, so that the friction resistance of the spiral mechanism is reduced to If the friction coefficient f is 0.1, let f = 0.1 = tan (θ), and we get θ = 5.7 degrees, that is, the equivalent friction angle of the spiral is equal to 5.7 degrees, that is, the self-locking angle is equal to 5.7 degrees). Since the lead angle of the torque shaft 13 is much larger than the friction angle of 5.7 degrees, when the torque is released, the rigid rebound ability of the dust plug 15 and the force sensing module 16 can easily reverse and loosen the torque shaft 13, so that the sensing value of the force sensing module 16 returns to zero.

[0078] Please refer to Fig. 8A and Figure 8B As shown in the figure, the structural setting of the parameter verification is to apply torque to the clamping force sensor 1 of the present invention with a torque tool, add a sleeve 10, pass the bolt 81 and washer 82 (spiral fastener 8) of a specific specification through the axial hole of the standard axial force gauge 9, lock it into the test seat 90, and then lock it with a nut 83. During the verification, the deformation sensing value generated by the axial thrust generated by the screw mechanism of the force sensing module 16 of the clamping force sensor 1 is amplified and processed into a digital sensing signal by the signal processing module 20, and then transmitted to the control device or display device by the signal transmission unit. The clamping force measured by the locked spiral fastener 8 through the standard axial force gauge 9 is also synchronously transmitted to the control device or display device to establish a parameter relationship between the clamping force and the deformation sensing value. In addition, as long as the specifications of the bolt 81, washer 82, nut 83, etc. of the spiral fastener 8 are changed, the parameters must be re-calibrated.

[0079] Please refer to Fig. 9 As shown in the figure, the clamping force sensor 1 of the present invention can be applied to various conventional torque tools. The clamping force sensor 1 is attached to the output end of the torque tool or built into the torque tool (such as Figure 4A , Figure 4B and Figure 5 ). As long as the parameters of the spiral fastener to be locked are checked in advance and matched with appropriate control or display equipment, after pairing and connection, the clamping force acting on the spiral fastener can be measured in real time during the process of the clamping force sensor 1 driving the sleeve to lock the spiral fastener, so that all torque tools can achieve accurate clamping force control.

[0080] Please refer to Fig.10 As shown in the figure, the clamping force sensor 1 of the present invention is Fig. 9Or when any torque tool is driven to tighten the spiral fastener, after pairing with the control device or display device, input the specifications of the spiral fastener and the target clamping force. During the locking process, the signal processing module will continue to transmit the clamping force calculated by the deformation sensing value to the control device or display device of the torque tool in real time by wire or wireless means. When the target clamping force is reached, it is determined whether it is qualified or not, and a warning sound or light is issued or the power source is cut off, and then the relevant data is uploaded to the surrounding server or cloud database as needed. In addition, when the deformation sensing value or clamping force exceeds the default value, the control device or display device of the torque tool can also issue an alarm and record it.

[0081] The present invention has been disclosed in the above with preferred embodiments, but those skilled in the art should understand that the embodiments are only used to describe the present invention and should not be interpreted as limiting the scope of the present invention. It should be noted that all changes and substitutions equivalent to the embodiments should be included in the scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope defined by the claims.

Claims

1. A bolt clamping force sensor for bolt locking operation, characterized in that: Include: The sensor body has a torque tool receiving portion at one end to match the size of the torque tool output end, and a screw hole with a spiral guide groove at the other end. The force sensing module is accommodated at the bottom of the screw hole and can be locked into the corresponding spiral guide groove of the torque shaft; The force sensing module includes a sensing ring body and a force sensing component. The outer edge of the sensing ring body has a ring groove. The force sensing component is attached to the bottom of the ring groove to sense the axial deformation sensing value of the sensing ring body and is electrically connected to the signal processing module. A dust plug, which is placed between the force sensing module and the torque shaft, and is provided with a leak-proof ring to prevent foreign matter from entering the force sensing module; The torque shaft has a plurality of spiral guide grooves corresponding to the screw holes in the sensor body at one end of the shaft diameter, and a driving head corresponding to the size of the input end of the sleeve at the other end to lock the spiral fastener; Steel balls, which are filled in plurality between the spiral guide groove of the sensor body and the spiral guide groove of the torque shaft to reduce friction resistance during rotation; The signal processing module is placed inside or outside the sensor body and has a signal amplifier, a microprocessor, a power circuit unit, a signal transmission unit, an input / output module, a gyroscope, a memory unit, a transmission antenna and an alarm unit; the signal amplifier amplifies the sensing signal transmitted from the force sensing module to the signal processing module via the connecting line, and then the microprocessor calculates the corresponding clamping force value with preset parameters; the power circuit unit is used to convert the externally supplied power into the power required by the power module; the signal transmission unit is a wireless RF, Bluetooth, WiFi or ZigBee, or the signal transmission unit is a wired RS232, RS485 or UART to transmit to the control or display device; the input / output module is a USB for battery charging and firmware update; the gyroscope is used to detect the angular displacement of the bolt clamping force sensor; the memory unit memorizes the parameter relationship obtained by verifying each spiral fastener to be locked and the deformation sensing value of the force sensing module with the standard axial force gauge; the alarm unit is a buzzer or an LED light to indicate the signal strength, power status or usage status; The power module is a rechargeable battery and is electrically connected to the signal processing module; A fixing base is locked to the sensor body and covers the signal processing module and the power module with a protective cover; A protective cover, made of a material that does not block wireless signal transmission, for protecting the signal processing module and the power module; A connecting line electrically connecting the force sensing component and the signal processing module of the force sensing module; and The fixing ring is used to support the torque shaft so that it can slide in the screw hole of the sensor body without falling off.

2. The bolt clamping force sensor according to claim 1, characterized in that: The spiral guide groove of the sensor body and the spiral guide groove of the torque shaft respectively have the same number of spiral turns and the same spiral direction as the spiral fastener to be locked.

3. The bolt clamping force sensor according to claim 1, characterized in that: The lead angle of the spiral guide groove of the torque shaft is greater than the friction angle, and the axial thrust of the torque shaft acting on the dust plug and the sensing ring body is within the yield strength range of the torque shaft, the dust plug and the sensing ring body, so that the torque shaft can reverse and reset along the spiral guide groove through the rigid rebound ability of the two, so that the sensing value of the force sensing module returns to zero.

4. The bolt clamping force sensor according to claim 1, characterized in that: The signal processing module transmits the clamping force calculated by the deformation sensing value to the control device or display device of the torque tool in a wired or wireless manner to control the clamping force of the spiral fastener. When the deformation sensing value or the clamping force exceeds the default value, the control device or display device of the torque tool issues an alarm and records it.

5. The bolt clamping force sensor according to claim 1, characterized in that: The force sensing module is a sensing component capable of sensing axial force.

6. The bolt clamping force sensor according to claim 1, characterized in that: When a torque is applied to the torque shaft, the screw fastener is locked at the lower end through the upper and lower coaxially rotating screw mechanisms, while the screw mechanism at the other end presses the force sensing module, and the clamping force acting on the screw fastener at that time is calculated by the signal processing module according to the clamping force conversion parameters established in advance.

7. The bolt clamping force sensor according to claim 6, characterized in that: The microprocessor calculates the parameters used, applies torque to the bolt clamping force sensor to lock the spiral fastener and the standard axial force meter, establishes the deformation sensing value of the force sensing module of the bolt clamping force sensor and the clamping force conversion parameter acting on the spiral fastener, and stores them in the memory unit of the signal processing module or the matched control or display device.

8. The bolt clamping force sensor according to claim 7, characterized in that: The clamping force conversion parameters must be recalibrated when any of the contents of the screw fasteners are changed, such as the bolt specifications, gaskets or objects to be locked.

9. The bolt clamping force sensor according to claim 1, characterized in that: The signal processing module transmits the clamping force calculated from the deformation sensing value to the control or display device of the torque tool in a wired or wireless manner to control the clamping force of the bolt; when the deformation sensing value or the clamping force exceeds the default value, the control or display device issues an alarm and records it.

10. The bolt clamping force sensor according to claim 1, characterized in that: The bolt clamping force sensor is externally mounted or built into a torque tool to be transformed into a clamping force wrench or a clamping force screwdriver that can directly detect the clamping force acting on the spiral fastener. The torque tool is a traditional torque wrench or a torque screwdriver.

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