Tightening tool with two sets of built-in torque sensors

Abstract

The utility model relates to the field of tightening and locking, in particular to a tightening tool internally provided with two groups of torque sensors and a verification-free method, the tightening tool further comprises a dynamic torque sensor and a static torque sensor, a power device is arranged on the static torque sensor, and counter-acting force provided by an external source is transmitted to the power device through the static torque sensor. The power device provides torsion for the output end through the dynamic torque sensor; in order to solve the problem that the torsion is abnormal but not known, a novel detection mode is used, the detection mode is that more than two torque sensors are utilized to respectively measure the torque on the power device and the torque on the output end, and then the two torque values are compared, so that the torque on the power device and the torque on the output end are detected. If the torque is outside the threshold value range, the problem that the torque accuracy is reduced exists on the power device or the output end, and according to the mode, the effect of real-time monitoring is achieved, and therefore the problem that the torque is abnormal and not known is solved.

Description

Technical Field

[0001] This utility model relates to the field of tightening and fastening, and more particularly to a tightening tool with built-in dual torque sensors. Background Technology

[0002] Electric screwdriver calibration involves using a torque meter to ensure the accuracy of the electric screwdriver when applying torque.

[0003] There are generally two types of verification scenarios. The first is that workers must use a torque meter to verify the electric screwdriver before starting work each day. The second type of electric screwdriver verification is when the working time of the electric screwdriver has met the specified duration requirement. The latter duration requirement is an estimate. If the electric screwdriver is manually verified using a torque meter but has not yet met the specified duration requirement, the accurate value of the electric screwdriver will exceed the problem. Products made within this time period will have defects. Utility Model Content

[0004] To address the aforementioned issues, this invention provides a tightening tool with built-in dual torque sensors, offering a means to detect the output torque and the torque of the electric screwdriver. By judging the difference between the two torque values, the problem of undetected abnormal torque is solved.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: a tightening tool with built-in dual torque sensors, comprising a body, a power device disposed within the body, and an output end connected to the power device, characterized in that it further comprises a dynamic torque sensor and a static torque sensor, the power device being disposed on the static torque sensor, the reaction force provided by an external source being transmitted to the power device through the static torque sensor, and the power device providing torque to the output end through the dynamic torque sensor.

[0006] The beneficial effects of this utility model are:

[0007] 1. In order to solve the problem of undetected abnormal torque, this utility model uses a new detection method. This detection method uses two or more torque sensors to measure the torque on the power unit and the torque on the output end, and then compares the two torque values. If the value is outside the threshold range, it indicates that there is a problem in the power unit or the output end that causes the torque accuracy to decline. Based on this method, the effect of real-time monitoring is achieved, thereby solving the problem of undetected abnormal torque.

[0008] 2. At the same time, this comparison method can also verify whether the torque sensor has a problem of declining detection performance. That is to say, when the detection source of one of the torque sensors has reached the replacement requirement, its detection results are inaccurate. In order to make the output torque reach the threshold, the output end or power device will be made to work in an abnormal state, which will cause the torque data detected by the other torque sensor to be abnormal.

[0009] 3. Furthermore, by connecting the power unit to the output end via a dynamic torque sensor, the detection accuracy at the output end can be improved. In other words, it does not require multi-stage transmission. Therefore, the problem of torque loss due to multi-stage transmission, which leads to inaccurate detection accuracy, can also be improved. Moreover, the torque transmission path obtained by the existing torque sensor is: bit - planetary gearbox - torque sensor, while the dynamic detection sensor directly detects the torque at the output end. Therefore, the shortening of the detection path allows for more timely control of the power unit, in other words, reducing the delay in power unit control.

[0010] The static torque sensor consists of a connecting structure and a first resistance strain gauge. The middle part of the connecting structure consists of multiple spaced connecting plates. The first resistance strain gauge is set on the connecting plates. The connecting structure is made of an elastic material with a rebound effect. The advantage of this design is that the middle area of ​​the connecting structure is more likely to deform when subjected to torsion. Therefore, the first resistance strain gauge is set behind the connecting plates, and even small deformations caused by torsion will cause changes in resistance.

[0011] Specifically, the power unit includes a motor and a planetary gearbox. The motor's power unit is connected to a dynamic torque sensor via the planetary gearbox. The dynamic torque sensor is connected to the bit. The motor is connected to the end of the rotating shaft inside the main body, making the motor suspended. The above is just one implementation method. Depending on the requirements, the planetary gearbox or motor can be fixed inside the main body via a static torque sensor. Alternatively, three static torque sensors can be provided to detect the reaction force on the motor and planetary gearbox. The former has a cost advantage, while the latter is beneficial for troubleshooting.

[0012] Going a step further, the main body is the outer shell, and the static torque sensor is connected to the inner wall of the shell. The external source is usually hands or other devices, such as robotic arms. Motors and planetary gearboxes, which are power devices, will exert force on the shell. The reaction force brought by this external source through the shell is directly applied to the static torque sensor. This reaction force is the torque detected by the static torque sensor.

[0013] The dynamic torque sensor includes a rotating component, a brush, and a second resistance strain gauge. The rotating component has a cylindrical structure, with its first end being a deformation section. The second resistance strain gauge is located on the deformation section, and the brush is located on the second end of the rotating component, connected to the second resistance strain gauge. When the rotating component rotates in any direction, its reaction force is applied to the deformation section, causing the second resistance strain gauge to twist in accordance with the deformation of the deformation section. The change in cross-sectional area alters the current flowing to the brush, which then transmits a detection signal to the processor based on the change in resistance. This design primarily emphasizes the application of the second resistance strain gauge. The torque is calculated by analyzing the resistance change caused by the minute deformation resulting from the torsion. This method offers high sensitivity and accuracy, enabling the detection of minute torque changes.

[0014] The brush consists of a conductive slip ring and brush bristles. The conductive slip ring is fitted onto the second end of the rotating component. The conductive slip ring is recessed from both sides towards the middle. The brush bristles are tangential to the middle area of ​​the conductive slip ring. With this structure, the conductive slip ring itself has a certain restraining effect on the brush bristles, reducing the possibility of the brush bristles detaching from the conductive slip ring.

[0015] In this embodiment, there are two second resistance strain gauges and four conductive slip rings, with the conductive slip rings arranged in pairs, serving as the positive and negative electrodes of a single second resistance strain gauge.

[0016] Of course, there are also insulating rings between the conductive slip rings, and the bristles are separated by the insulating rings to prevent short circuits caused by contact between the positive and negative electrodes.

[0017] It also includes an insulating sleeve, a conductive slip ring, and an isolation ring located on the insulating sleeve, which is fitted onto the second end of the rotating component.

[0018] The above does not impose further limitations on the number of brush filaments and conductive slip rings. The number can be selected according to the needs. Of course, the number of second resistance strain gauges can also be multiple, and it is not limited to the use of only two.

[0019] Considering the static electricity generated at the output end, a grounding brush ring is also included. The grounding brush ring is fitted onto the rotating part, and a portion of the brush bristles are connected to the grounding brush ring. Static electricity at the output end is directly led out through the grounding brush ring, thus achieving the effect of removing static electricity.

[0020] It also includes a mounting bracket, on which the bristles are fixed and ejected at an angle.

[0021] In addition, the brush bristles, conductive slip ring, and grounding brush ring are all coated with a wear-resistant conductive coating, which improves wear resistance and extends the service life of the brush.

[0022] The deformation part is made of rubber material. When the deformation part is subjected to periodic torsion, the material will fatigue or crack. By using dual torque sensors, the problem can be detected by the other torque sensor when the deformation part of either torque sensor has a problem through numerical comparison.

[0023] Specifically, the inner end of the bit is connected to the first end of the rotating component, and the second end of the rotating component is connected to the output shaft of the planetary gearbox.

[0024] Advantageously, the main body also includes a warning alarm and a control circuit board. The control circuit board has a processor for comparing torque. The control terminal of the processor is connected to the input terminal of the alarm. The values ​​of the dynamic torque sensor and the static torque sensor are directly input into the control circuit board, and the processor in the control circuit board is responsible for comparison. When the difference between the static torque sensor and the dynamic torque sensor is greater than the preset value, an alarm will be automatically triggered. This eliminates the need for daily calibration, optimizes the work process, and improves work efficiency.

[0025] Of course, a display screen showing the torque value can also be installed on the main body for manual comparison.

[0026] The aforementioned control circuit board and processor are all existing technologies, and their structures will not be described in detail.

[0027] A calibration-free method for tightening tools, characterized by comprising:

[0028] S1, A dynamic torque sensor is set on the output end to collect the torque on the output end;

[0029] S2, the power unit is set on the static torque sensor, and the reaction force on the output is collected by the static torque sensor;

[0030] S3, the processor in the control circuit board collects the torque values ​​from the static torque sensor and the dynamic torque sensor and compares them.

[0031] S4. When the difference between the values ​​exceeds the threshold range, the processor determines that the device is abnormal, controls the circuit board to activate the alarm circuit, and the alarm sounds.

[0032] This method eliminates the need for daily verification, optimizes work processes, and improves work efficiency. Attached Figure Description

[0033] Figure 1 This is a perspective view of the present invention.

[0034] Figure 2 This is a cross-sectional view of the present invention.

[0035] Figure 3 yes Figure 2 Enlarged diagram of point A.

[0036] Figure 4 This is a perspective view of the present invention after the outer shell has been removed.

[0037] Figure 5 This is a 3D view of the dynamic torque sensor.

[0038] Figure 6 yes Figure 5 3D view after removing the brush bristles and insulating ring.

[0039] Figure 7 This is a 3D view of a static torque sensor. Detailed Implementation

[0040] A tightening tool with built-in dual torque sensors includes a body 1, a power unit and an output end connected to the power unit, a dynamic torque sensor 3 and a static torque sensor 4. The power unit is mounted on the static torque sensor 4. An externally supplied reaction force is transmitted to the power unit through the static torque sensor 4, and the power unit provides torque to the output end through the dynamic torque sensor 3.

[0041] The beneficial effects of this utility model are:

[0042] 1. In order to solve the problem of torque not being detected, this utility model uses a new detection method. This detection method uses two or more torque sensors to measure the torque on the power unit and the torque at the output end, and then compares the two torque values. If the value is outside the threshold range, it indicates that there is a problem in the power unit or the output end that causes the torque accuracy to decline. Based on this method, the effect of real-time monitoring is achieved, thereby solving the problem of abnormal torque not being detected.

[0043] 2. At the same time, this comparison method can also verify whether the torque sensor has a problem of declining detection performance. That is to say, when the detection source of one of the torque sensors has reached the replacement requirement, its detection results are inaccurate. In order to make the output torque reach the threshold, the output end or power device will be made to work in an abnormal state, which will cause the torque data detected by the other torque sensor to be abnormal.

[0044] 3. Furthermore, by connecting the power unit to the output end via the dynamic torque sensor 3, the detection accuracy at the output end can be improved. In other words, it does not need to go through multiple stages of transmission. Therefore, the problem of torque loss due to multiple stages of transmission, which leads to inaccurate detection accuracy, can also be improved. Moreover, the transmission path of torque obtained by the existing torque sensor is: bit 2 - planetary gearbox 6 - torque sensor, while the dynamic detection sensor 3 directly detects the torque at the output end. Therefore, the reduction of the detection path makes the control of the power unit more timely, in other words, it reduces the delay in the control of the power unit.

[0045] The static torque sensor 4 consists of a connecting structure and a first resistance strain gauge (not shown in the figure). The middle part of the connecting structure consists of multiple spaced connecting pieces 41. The first resistance strain gauge is set on the connecting pieces 41. The connecting structure is made of an elastic material with a rebound effect (preferably steel). The advantage of this design is that the middle area of ​​the connecting structure is more likely to deform when subjected to torsion. Therefore, after the first resistance strain gauge is set on the connecting piece 41, even a small deformation caused by torsion will cause a change in resistance.

[0046] Specifically, the power unit includes a motor 5, a planetary gearbox 6, and a bit 2 as the output end. The output shaft of the motor 5 is connected to a dynamic torque sensor 3 through the planetary gearbox 6. The dynamic torque sensor 3 is connected to the bit 2. The connection structure is set between the motor 5 and the planetary gearbox 6. The motor 5 is connected to the end of the rotating shaft inside the body 1, so that the motor 5 is suspended. The above is only one embodiment.

[0047] Depending on the requirements, the planetary gearbox 6 or the motor 5 can be fixed inside the body 1 by a static torque sensor 4. Alternatively, three static torque sensors can be provided to simultaneously detect the reaction force on the motor 5 and the planetary gearbox 6. The former has a cost advantage, while the latter is beneficial for troubleshooting.

[0048] To go a step further, the main body 1 is the outer shell, and the static torque sensor 4 is connected to the inner wall of the outer shell. The external source is usually the hands or other equipment, such as a robotic arm. The motor 5 and planetary gearbox 6, which are the power devices, will apply force to the outer shell. This external source is directly applied to the static torque sensor 4 through the reaction force brought by the outer shell. This reaction force is the torque detected by the static torque sensor 4.

[0049] The dynamic torque sensor 3 includes a rotating component 31, a brush, and a second resistance strain gauge (not shown in the figure). The rotating component 31 has a cylindrical structure, and the first end of the rotating component 31 is a deformation part 31a. The second resistance strain gauge is disposed on the deformation part 31a, and the brush is located on the second end of the rotating component 31 and is connected to the second resistance strain gauge. When the rotating component 31 rotates in any direction, its reaction force is applied to the deformation part 31a, and the second resistance strain gauge undergoes a certain torsion following the deformation of the deformation part 31a. The change in cross-sectional area changes the magnitude of the current to the brush, and the brush transmits the detection signal after the change in resistance to the processor. This design mainly highlights the application of the second resistance strain gauge. The torque is calculated by the resistance change caused by the small deformation generated by torsion. This method has high sensitivity and accuracy and can detect small torque changes.

[0050] The brush includes a conductive slip ring 32 and brush bristles 33. The conductive slip ring 32 is fitted on the second end of the rotating part 31. The conductive slip ring 32 is recessed from both sides to the middle. The brush bristles 33 are tangential to the middle area of ​​the conductive slip ring 32. In this structure, the conductive slip ring itself has a certain restraining effect on the brush bristles 33, reducing the possibility of the brush bristles 33 detaching from the conductive slip ring.

[0051] In this embodiment, there are two second resistance strain gauges and four conductive slip rings 32, and the conductive slip rings 32 are arranged in pairs, serving as the positive and negative poles of a single second resistance strain gauge.

[0052] Of course, an isolation ring 34 is also provided between the conductive slip rings 32, and the brush bristles 33 are separated by the isolation ring 34 to avoid short circuit caused by contact between the positive and negative electrodes.

[0053] It also includes an insulating sleeve 36, a conductive slip ring 32, and an isolation ring 34 located on the insulating sleeve 36, with the insulating sleeve 36 fitted onto the second end of the rotating component 31.

[0054] The above does not further limit the number of brush filaments 33 and conductive slip rings 32. The number can be selected according to the needs. Of course, the number of second resistance strain gauges can also be multiple, and it is not limited to the use of only 2.

[0055] Considering the static electricity generated on the bit 2, a grounding brush ring 35 is also included. The grounding brush ring 35 is fitted on the second end of the rotating part 31, and a portion of the brush bristles 33 are connected to the grounding brush ring 35. The static electricity on the bit 2 is directly led out through the grounding brush ring 35, thus achieving the effect of removing static electricity.

[0056] It also includes a mounting bracket, on which the bristles 33 are fixed, and the bristles 33 are ejected at an angle.

[0057] In addition, the brush bristles 33, the conductive slip ring 32, and the grounding brush ring 35 are all coated with a wear-resistant conductive coating, which improves wear resistance and extends the service life of the brush.

[0058] The deformation part 31a is made of rubber material. When the deformation part 31a is subjected to periodic torsion, the material will fatigue or crack. By using dual torque sensors, the torque values ​​can be compared so that if the deformation part 31a of any torque sensor has a problem, the problem can be detected by the other torque sensor.

[0059] Specifically, the inner end of the bit 2 is connected to the deformable part 31a of the rotating part 31, and the second end of the rotating part 31 is connected to the output shaft of the planetary gearbox 6.

[0060] Advantageously, the main body 1 is also equipped with a warning alarm and a control circuit board. The values ​​of the dynamic torque sensor 3 and the static torque sensor 4 are directly input into the control circuit board, and the processor in the control circuit board is responsible for comparison. When the difference between the static torque sensor 4 and the dynamic torque sensor 3 is greater than the preset value, an alarm will be automatically triggered. This eliminates the need for daily calibration, optimizes the work process, and improves work efficiency.

[0061] Of course, a display screen showing the torque value can also be set on the main body 1 for manual comparison.

[0062] The aforementioned control circuit board and processor are all existing technologies, and their structures will not be described in detail.

[0063] A calibration-free method for tightening tools, characterized by comprising:

[0064] S1, A dynamic torque sensor 3 is installed on the bit to collect the torque on the bit.

[0065] S2, the power unit is set on the static torque sensor 4, and the reaction force on the output is collected by the static torque sensor 4;

[0066] S3, the processor in the control circuit board collects the torque values ​​from the static torque sensor 4 and the dynamic torque sensor 3, and compares them.

[0067] S4. When the difference between the values ​​exceeds the threshold range, the processor determines that the device is abnormal, controls the circuit board to activate the alarm circuit, and the alarm sounds.

[0068] This method eliminates the need for daily verification, optimizes work processes, and improves work efficiency.

[0069] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A tightening tool with built-in dual torque sensors, comprising a body, a power unit housed within the body, and an output end connected to the power unit, characterized in that, It also includes a dynamic torque sensor and a static torque sensor. The power unit is mounted on the static torque sensor. The reaction force provided by the external source is transmitted to the power unit through the static torque sensor. The power unit provides torque to the output end through the dynamic torque sensor.

2. A tightening tool with a built-in dual-set torque sensor according to claim 1, characterized in that, The static torque sensor consists of a connecting structure and a first resistance strain gauge. The middle part of the connecting structure consists of multiple spaced connecting pieces. The first resistance strain gauge is set on the connecting pieces. The connecting structure is made of an elastic material with a rebound effect.

3. A tightening tool with a built-in dual-set torque sensor according to claim 1, characterized in that, The power unit includes a motor and a planetary gearbox. The motor's power unit is connected to a dynamic torque sensor through the planetary gearbox. The dynamic torque sensor is connected to the output end. The motor is connected to the end of the rotating shaft inside the main body, making the motor suspended.

4. A tightening tool with a built-in dual-set torque sensor according to claim 1, characterized in that, The dynamic torque sensor includes a rotating component, a brush, and a second resistance strain gauge. The rotating component has a cylindrical structure, and the first end of the rotating component is a deformation part. The second resistance strain gauge is disposed on the deformation part, and the brush is located on the second end of the rotating component and is connected to the second resistance strain gauge. When the rotating component rotates in any direction, its reaction force is applied to the deformation part, and the second resistance strain gauge twists along with the deformation of the deformation part.

5. A tightening tool with a built-in dual-set torque sensor according to claim 4, characterized in that, The brush consists of a conductive slip ring and brush bristles. The conductive slip ring is fitted onto the second end of the rotating part. The conductive slip ring is recessed from both sides towards the middle. The brush bristles are tangential to the middle area of ​​the conductive slip ring.

6. A tightening tool with a built-in dual-set torque sensor according to claim 5, characterized in that, An insulating ring is also provided between the conductive slip rings, and the brush bristles are separated by the insulating ring.

7. A tightening tool with a built-in dual-set torque sensor according to claim 6, characterized in that, It also includes an insulating sleeve, a conductive slip ring, and an isolation ring located on the insulating sleeve, which is fitted onto the second end of the rotating component.

8. A tightening tool with a built-in dual-set torque sensor according to claim 4, characterized in that, It also includes a grounding brush ring, which is fitted onto the rotating part, and a portion of the brush filaments are connected to the grounding brush ring.

9. A tightening tool with a built-in dual-set torque sensor according to claim 1, characterized in that, The main body also contains a warning alarm and a control circuit board. The control circuit board has a processor that compares torque, and the control terminal of the processor is connected to the input terminal of the alarm.

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