Power tool reverse torque suppression device

Abstract

A power tool reverse torque suppression device includes a transmission unit, a magnetic force generating unit and a driven unit. The magnetic force generating unit is arranged on a main shaft of the transmission unit, the main shaft rotates relative to the magnetic force generating unit, the magnetic force generating unit has a stop surface, the stop surface is provided with a first positioning portion; the driven unit is sleeved on the main shaft and faces the stop surface, the driven unit is displaced along the main shaft direction relative to the magnetic force generating unit between a first position and a second position, the driven unit includes a second positioning portion; when the driven unit is at the first position, the second positioning portion is separated from the first positioning portion; when the magnetic force generating unit generates an attractive magnetic force, the magnetic force generating unit drives the driven unit to displace to the second position, the second positioning portion is engaged with the first positioning portion to limit the rotation of the main shaft.

Description

Technical Field

[0001] This invention relates to power tool technology; in particular, it relates to a reverse torque suppression device for power tools. Background Technology

[0002] Traditional power tools, such as electric torque screwdrivers or electric torque wrenches without a clutch mechanism, allow users to set a torque and tighten screws, nuts, and other workpieces according to that setting. When the tightening torque reaches the user-set torque, the power tool's motor immediately stops rotating. This allows the workpiece to be tightened to the user-defined torque.

[0003] However, during the workpiece locking process, the user must exert force to resist the rotational force generated by the power tool while holding it to maintain stability. However, the higher the torque used to lock the workpiece, the greater the reaction force on the user's hand. When the power tool locks the workpiece, the motor stops driving. Since there is no clutch mechanism between the motor and the spindle, the motor cannot stop the spindle from rotating, leaving it with rotational inertia. This means the power tool cannot immediately absorb the rotational force when locking the workpiece, requiring the user to apply additional force to control the tool. Prolonged use can easily cause wrist discomfort or fatigue.

[0004] Therefore, the design of traditional power tools is still imperfect and there are still areas for improvement. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a reverse torque suppression device for power tools, which can reduce the discomfort experienced by users when using power tools to lock workpieces.

[0006] To achieve the above objectives, the electric tool reverse torque suppression device provided by the present invention includes a transmission unit, a magnetic force generating unit, and a driven unit. The transmission unit has a main shaft with a slide rail section on it. A magnetic force generating unit passes through the main shaft, and the main shaft rotates relative to the magnetic force generating unit. The magnetic force generating unit has a stop surface with a first positioning part. A driven unit is sleeved on the slide rail section of the main shaft and faces the stop surface of the magnetic force generating unit. The driven unit can be driven to rotate by the main shaft. The driven unit moves relative to the magnetic force generating unit along the direction of the main shaft between a first position and a second position. The driven unit has a second positioning part that engages with the first positioning part. When the driven unit is in the first position, the second positioning part disengages from the first positioning part. When the magnetic force generating unit generates an attractive magnetic force, it drives the driven unit towards the stop surface and into the second position, where the second positioning part engages with the first positioning part, thus restricting the rotation of the main shaft.

[0007] The advantage of this invention is that when the power tool is locking or disassembling a workpiece, the driven unit is located in the first position and can be driven to rotate by the spindle. When the power tool encounters a torque increase that reaches the set torque, the transmission unit stops transmission. At this time, the magnetic force generating unit can generate an attractive magnetic force to drive the driven unit. The driven unit moves from the first position to the second position, so that the second positioning part engages with the first positioning part. The driven unit restricts the rotation of the spindle and stops the rotation of the spindle, which can effectively reduce the discomfort caused by the reaction force to the user's hand during the high torque stage. Attached Figure Description

[0008] Figure 1 This is a perspective view of the reverse torque suppression device for power tools according to the first preferred embodiment of the present invention.

[0009] Figure 2 This is an exploded view of the reverse torque suppression device for power tools according to the first preferred embodiment of the present invention.

[0010] Figure 3 This is a plan view of the cover plate of the magnetic force generating unit according to the first preferred embodiment of the present invention.

[0011] Figure 4 This is a plan view of the metal plate of the driven unit according to the first preferred embodiment of the present invention.

[0012] Figure 5 This is a schematic diagram of the driven unit in the first position according to the first preferred embodiment of the present invention.

[0013] Figure 6 This is a diagram showing the operation of the driven unit in the second position according to the first preferred embodiment of the present invention.

[0014] Figure 7 This is a structural diagram of the power tool reverse torque suppression device according to the second preferred embodiment of the present invention.

[0015] Figure 8 This is a perspective view of the reverse torque suppression device for power tools according to the third preferred embodiment of the present invention.

[0016] Figure 9 This is an exploded view of the reverse torque suppression device for power tools according to the third preferred embodiment of the present invention.

[0017] Figure 10 This is a side view of the driven unit in the first position according to the third preferred embodiment of the present invention.

[0018] Figure 11 This is a side view of the driven unit in the second position according to the third preferred embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures

[0020] 1: Machine tool housing

[0021] 100, 100', 200: Power tool reverse torque suppression device

[0022] 10, 40: Transmission unit

[0023] 11, 41: Motor

[0024] 111, 411: Gearbox

[0025] 12, 42: Spindle

[0026] 121, 421: Sliding rail section

[0027] 1211, 4211: Slider

[0028] 122, 422: First smooth segment

[0029] 123, 423: Second smooth segment

[0030] 13, 43: Retaining ring

[0031] 20, 50: Magnetic force generating unit

[0032] 21, 51: Electromagnetic coil module

[0033] 211: Container

[0034] 212, 511: Electromagnetic coil

[0035] 22, 52: Cover plate

[0036] 221, 521: Stop surface

[0037] 222: Perforation

[0038] 223, 522: Electromagnetic opening

[0039] 23, 53: First Positioning Section

[0040] 231, 531: Convex column

[0041] 232: Spring

[0042] 30, 60: Driven unit

[0043] 31, 61: Metal sheet

[0044] 311: Shaft hole

[0045] 312: Groove

[0046] 32: Magnet

[0047] 33, 63: Second positioning section

[0048] 331, 631: Limiting groove

[0049] 34, 64: Elastic components

[0050] P1, P1': First position

[0051] P2, P2': Second position Detailed Implementation

[0052] To more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Please refer to... Figure 1 , Figure 2 and Figure 5 The electric tool reverse torque suppression device 100 provided in the first preferred embodiment of the present invention is used to be installed inside a tool housing 1. The electric tool reverse torque suppression device 100 includes a transmission unit 10, a magnetic force generating unit 20 and a driven unit 30.

[0053] The transmission unit 10 includes a motor 11 and a spindle 12. The motor 11 is fixed to the tool housing 1, and the motor 11 drives the spindle 12 to rotate. Figure 2 and Figure 5As shown, the motor 11 has a gearbox 111 connected to the main shaft 12. The main shaft 12 has a slide rail section 121, a first smooth section 122, and a second smooth section 123. The slide rail section 121 has a plurality of sliders 1211 surrounding it. The plurality of sliders 1211 are arranged along the direction of the main shaft 12. The first smooth section 122 and the second smooth section 123 are located on both sides of the slide rail section 121. The first smooth section 122 and the second smooth section 123 are respectively flat surfaces of the main shaft 12. The gearbox 111 is pivotally connected to the first smooth section 122. The motor 11 drives the main shaft 12 to rotate through the gearbox 111. The main shaft 12 is provided with a retaining ring 13. The retaining ring 13 is fixed to the second smooth section 123 and close to the slide rail section 121.

[0054] The magnetic force generating unit 20 passes through the main shaft 12 of the transmission unit 10. In the first embodiment, the magnetic force generating unit 20 passes through the first smooth section 122 of the main shaft 12, and the magnetic force generating unit 20 is fixed to the tool housing 1, so that the main shaft 12 rotates relative to the magnetic force generating unit 20. Figure 2 and Figure 5 As shown, the magnetic force generating unit 20 includes an electromagnetic coil module 21, a cover plate 22, and a first positioning part 23. The electromagnetic coil module 21 is connected to a controller (not shown in the figure). The controller can control the electromagnetic coil module 21 to generate an attractive magnetic force and a repulsive magnetic force. The electromagnetic coil module 21 has multiple slots 211 and multiple electromagnetic coils 212. The multiple slots 211 are arranged around the main shaft 12, and the openings of the multiple slots 211 face the slide rail section 121 of the main shaft 12. Electromagnetic coils 212 are arranged along the main shaft 12 and surround the main shaft 12. The two ends of the plurality of electromagnetic coils 212 are respectively exposed on both sides of the electromagnetic coil module 21. The plurality of electromagnetic coils 212 can be connected in series or in parallel, and can be controlled to generate the attractive magnetic force and the repulsive magnetic force. A cover plate 22 is attached to one side of the electromagnetic coil module 21. The cover plate 22 has a stop surface 221 facing the slide rail section 121 of the main shaft 12. Figure 3 and Figure 5As shown, the stop surface 221 has multiple through holes 222 and multiple electromagnetic openings 223. The multiple through holes 222 correspond to the positions of the multiple receiving grooves 211, and the multiple electromagnetic openings 223 correspond to the positions of the multiple electromagnetic coils 212, so that one end of the multiple electromagnetic coils 212 is exposed in the multiple electromagnetic openings 223 of the stop surface 221 and is not blocked by the cover plate 22. The first positioning part 23 is disposed between the electromagnetic coil module 21 and the cover plate 22. In the first embodiment, the first positioning part 23 includes multiple protrusions 231 and multiple springs 232. The multiple protrusions 231 and the multiple springs 232 are respectively accommodated in the multiple receiving grooves 211. The multiple protrusions 231 are pushed out of the multiple through holes 222 by the multiple springs 232, so that the multiple protrusions 231 normally protrude from the stop surface 221 of the cover plate 22, and the multiple protrusions 231 can elastically retract into the stop surface 221 when pressed.

[0055] In other embodiments, the structure of the magnetic force generating unit 20 can be adjusted as needed. For example, the cover plate 22 can be omitted from the magnetic force generating unit 20, and the plurality of springs 232 can be omitted from the first positioning part 23. That is, the magnetic force generating unit 20 only needs to have the stop surface 221, and the plurality of protrusions 231 of the first positioning part 23 can be fixedly disposed on the stop surface 221.

[0056] The driven unit 30 is sleeved on the slide rail section 121 of the main shaft 12, and the driven unit 30 faces the stop surface 221 of the cover plate 22. The magnetic force generating unit 20 is located between the motor 11 and the driven unit 30. The driven unit 30 can be driven to rotate by the main shaft 12. The driven unit 30 moves relative to the magnetic force generating unit 20 along the direction of the main shaft 12 between a first position P1 and a second position P2. The driven unit 30 is blocked by the magnetic force generating unit 20 and the retaining ring 13 and will not disengage from the slide rail section 121 of the main shaft 12. In the first embodiment, as shown... Figure 2 , Figure 4 and Figure 5As shown, the driven unit 30 includes a metal plate 31, a magnet 32, and a second positioning part 33. The metal plate 31 is sleeved on the slide rail section 121 of the main shaft 12, and the metal plate 31 can be driven by the magnetic attraction force of the magnetic force generating unit 20 to move towards the stop surface 221 of the cover plate 22. The metal plate 31 has a shaft hole 311, and the inner edge of the shaft hole 311 is provided with a plurality of grooves 312 corresponding to the plurality of sliders 1211 of the slide rail section 121. The magnet 32 ​​and the second positioning part 33 are respectively disposed on the metal plate 31. The magnet 32 ​​can be driven by the electric force generating unit 20 to move towards the stop surface 221 of the cover plate 22. The attraction and repulsion of the magnetic coil module 21 allow the metal plate 31 to move between the first position P1 and the second position P2. The second positioning part 33 engages with the first positioning part 23. The second positioning part 33 consists of multiple limiting grooves 331 that surround the shaft hole 311. The positions of the multiple limiting grooves 331 correspond to the multiple protrusions 231, but are not limited thereto. In other embodiments, the forms of the first positioning part 23 and the second positioning part 33 can be interchanged, as long as the first positioning part 23 and the second positioning part 33 can engage with each other.

[0057] like Figure 5 As shown, during the actual locking or disassembly operation of the power tool reverse torque suppression device 100, the driven unit 30 is initially located at the first position P1. There is a gap between the metal plate 31 of the driven unit 30 and the cover plate 22 of the magnetic force generating unit 20, and the second positioning part 33 of the driven unit 30 is disengaged from the first positioning part 23 of the magnetic force generating unit 20. The motor 11 of the transmission unit 10 can drive the spindle 12 to rotate relative to the magnetic force generating unit 20, and the metal plate 31 of the driven unit 30 rotates with the spindle 12.

[0058] like Figure 6As shown, when the power tool reverse torque suppression device 100 encounters a torque increase reaching a set torque, the plurality of electromagnetic coils 212 of the electromagnetic coil module 21 are controlled to generate the attracting magnetic force. The metal plate 31 and the magnet 32 ​​of the driven unit 30 are attracted by the electromagnetic coil module 21, causing the metal plate 31 to be driven upward by the electromagnetic coil module 21 and move towards the stop surface 221 of the cover plate 22. The driven unit 30 moves from the first position P1 to the second position P2. At least one protrusion 231 of a positioning part 23 can be inserted into one of the limiting grooves 331 of the second positioning part 33, so that the second positioning part 33 engages with the first positioning part 23. The second positioning part 33 of the driven unit 30 is limited by the first positioning part 23 of the magnetic force generating unit 20 and stops rotating. The driven unit 30 correspondingly restricts the rotation of the main shaft 12, thereby counteracting the rotational force of the main shaft 12. This can effectively reduce the discomfort caused by the reaction force to the user's hand during the high torque stage.

[0059] In addition, when the power tool reverse torque suppression device 100 needs to restore the operation of the transmission unit 10, the electromagnetic coil module 21 can switch from the attractive magnetic force to the repulsive magnetic force. The magnet 32 ​​of the driven unit 30 is pushed back by the repulsive magnetic force of the electromagnetic coil module 21, so that the magnet 32 ​​moves the metal plate 31 away from the cover plate 22. The driven unit 30 is reset from the second position P2 to the first position P1, releasing the restriction relationship between the first positioning part 23 and the second positioning part 33, thereby restoring the transmission operation of the transmission unit 10.

[0060] It is worth noting that the action of the driven unit 30 resetting from the second position P2 to the first position P1 is not limited to being achieved by generating the repulsive magnetic force through the electromagnetic coil module 21. For example, please refer to... Figure 7This is a power tool reverse torque suppression device 100' provided in the second preferred embodiment of the present invention, comprising the aforementioned transmission unit 10, the aforementioned magnetic force generating unit 20, and the aforementioned driven unit 30. The structural description of the transmission unit 10, the magnetic force generating unit 20, and the driven unit 30 in the second embodiment is substantially the same as that in the first embodiment. In the second embodiment, the driven unit 30 replaces the magnet with an elastic element 34, which is a tension spring. The two ends of the elastic element 34 are connected to the metal plate 31 and... The retaining ring 13, the metal plate 31 of the driven unit 30 is held at the first position P1 by the tension of the elastic member 34. When the driven unit 30 is in the second position P2, the elastic member 34 continues to pull the metal plate 31. When the electromagnetic coil module 21 closes the attraction magnetic force, the metal plate 31 is pulled away from the stop surface 221 of the cover plate 22 by the tension of the elastic member 34, thus completing the action of the driven unit 30 resetting from the second position P2 to the first position P1.

[0061] In addition, please refer to Figures 8 to 11 The electric tool reverse torque suppression device 200 provided in the third preferred embodiment of the present invention includes a transmission unit 40, a magnetic force generating unit 50 and a driven unit 60.

[0062] The transmission unit 40 includes a motor 41 and a main shaft 42, wherein the motor 41 drives the main shaft 42 to rotate. Figure 9 As shown, the motor 41 has a gearbox 411 connected to the main shaft 42. The main shaft 42 has a slide rail section 421, a first smooth section 422, and a second smooth section 423. The slide rail section 421 has a plurality of sliders 4211 surrounding it. The first smooth section 422 and the second smooth section 423 are located on both sides of the slide rail section 421. The gearbox 411 is pivotally connected to the first smooth section 422. The main shaft 42 is provided with a retaining ring 43, which is fixed to the first smooth section 423 and close to the motor 41.

[0063] The magnetic force generating unit 50 passes through the main shaft 42 of the transmission unit 40. The structure of the magnetic force generating unit 50 in the third embodiment is substantially the same as that of the magnetic force generating unit 20 in the first embodiment. In the third embodiment, the magnetic force generating unit 50 passes through the second smooth section 423 of the main shaft 42, and the magnetic force generating unit 50 is fixed to a tool housing (not shown). The main shaft 42 rotates relative to the magnetic force generating unit 50. Figure 9 and Figure 10As shown, the magnetic force generating unit 50 includes an electromagnetic coil module 51, a cover plate 52, and a first positioning part 53. The electromagnetic coil module 51 has multiple electromagnetic coils 511, which can generate an attractive magnetic force. The cover plate 52 is attached to one side of the electromagnetic coil module 51. The cover plate 52 has a stop surface 521 facing the motor 41. Multiple electromagnetic openings 522 are penetrating the stop surface 521. The multiple electromagnetic openings 522 correspond to the positions of the multiple electromagnetic coils 511, so that one end of the multiple electromagnetic coils 511 is exposed in the multiple electromagnetic openings 522 of the stop surface 521 and is not blocked by the cover plate 52. The first positioning part 53 is disposed between the electromagnetic coil module 51 and the cover plate 52. The first positioning part 53 includes multiple protrusions 531, which protrude from the stop surface 521 of the cover plate 52.

[0064] The driven unit 60 is sleeved on the slide rail section 421 of the main shaft 42. The driven unit 60 faces the stop surface 521 of the cover plate 52, and is located between the motor 41 and the magnetic force generating unit 50. The driven unit 60 can be driven to rotate by the main shaft 42. The driven unit 60 moves relative to the magnetic force generating unit 50 along the direction of the main shaft 42 between a first position P1' and a second position P2'. The structure of the driven unit 60 in the third embodiment is substantially the same as that of the driven unit 30 in the second embodiment. In the third embodiment, as shown... Figure 9 and Figure 10 As shown, the driven unit 60 includes a metal plate 61, a second positioning part 63, and an elastic member 64. The metal plate 61 is sleeved on the slide rail section 421 of the main shaft 42. The second positioning part 63 is disposed on the metal plate 61 and is correspondingly engaged with the first positioning part 53. The second positioning part 63 consists of multiple limiting grooves 631, and the positions of the multiple limiting grooves 631 correspond to the multiple protrusions 531. The two ends of the elastic member 64 connect the metal plate 61 and the retaining ring 43. The metal plate 61 is held at the first position P1' by the tension of the elastic member 64. At this time, there is a gap between the metal plate 61 of the driven unit 60 and the cover plate 52 of the magnetic force generating unit 50, and the second positioning part 63 of the driven unit 60 is disengaged from the first positioning part 53 of the magnetic force generating unit 50, so that the motor 41 of the transmission unit 40 can drive the main shaft 42 to rotate.

[0065] like Figure 9 and Figure 11As shown, when the reverse torque suppression device 200 of the power tool encounters a torque increase that reaches the set torque, the electromagnetic coil module 51 is controlled to generate the attraction magnetic force. The metal plate 61 can be driven by the electromagnetic coil module 51 to move downward toward the stop surface 521 of the cover plate 52, and the driven unit 60 moves from the first position P1' to the second position P2'. The protrusion 531 of the first positioning part 53 can be inserted into the limiting groove 631 of the second positioning part 63, so that the second positioning part 63 and the first positioning part 53 are engaged. In this way, the driven unit 60 restricts the rotation of the spindle 42, and also reduces the discomfort caused to the user's hand by the reaction force.

[0066] Furthermore, when the power tool reverse torque suppression device 200 needs to restore the operation of the transmission unit 40, it is only necessary to turn off the attractive magnetic force of the electromagnetic coil module 51. The metal plate 61 is pulled away from the stop surface 521 of the cover plate 52 by the elastic member 64, and the driven unit 60 is reset from the second position P2' to the first position P1', releasing the restrictive relationship between the first positioning part 53 and the second positioning part 63, thereby restoring the transmission operation of the transmission unit 40. In other embodiments, The driven unit 60 omits the elastic element 64 and replaces it with a magnet. The magnet is disposed on the metal plate 61. The electromagnetic coil module 51 can generate a repulsive magnetic force. When the electromagnetic coil module 51 switches from the attractive magnetic force to the repulsive magnetic force, the magnet of the driven unit 60 is pushed back by the repulsive magnetic force of the electromagnetic coil module 51. The magnet moves the metal plate 61 away from the cover plate 52, thus completing the action of the driven unit 60 returning to the first position P1'.

[0067] As described above, when a power tool encounters a torque increase reaching a set torque during the process of locking or disassembling a workpiece, the power tool reverse torque suppression devices 100 and 200 drive the driven units 30 and 60 from the first positions P1 and P1' to the second positions P2 and P2' via the magnetic force generating units 20 and 50. The second positioning parts 33 and 63 engage with the first positioning parts 23 and 53, stopping the rotation of the spindles 12 and 42. This effectively reduces the risk of hand injury during high torque operations. The discomfort caused by the force can be relieved when the reverse torque suppression device 100, 200 of the power tool needs to restore the operation of the transmission unit 10, 40. The driven unit 30, 60 can be controlled to move away from the magnetic force generating unit 20, 50, thereby releasing the restriction relationship between the first positioning part 23, 53 and the second positioning part 33, 63. In other words, the driven unit 30, 60 can be reset from the second position P2, P2' to the first position P1, P1', and the transmission operation of the transmission unit 10, 40 can be restored.

[0068] The above description is only a preferred embodiment of the present invention. Any equivalent changes made by applying the present invention specification and the claims should be included within the patent scope of the present invention.

Claims

1. A reverse torque suppression device for power tools, comprising: A transmission unit has a main shaft, on which a slide rail section is provided; A magnetic force generating unit is inserted through the main shaft, the main shaft rotates relative to the magnetic force generating unit, the magnetic force generating unit has a stop surface, and the stop surface is provided with a first positioning part; as well as A driven unit is sleeved on the slide rail section of the main shaft and faces the stop surface of the magnetic force generating unit. The driven unit can be driven to rotate by the main shaft. The driven unit can move relative to the magnetic force generating unit along the direction of the main shaft between a first position and a second position. The driven unit includes a second positioning part. When the driven unit is in the first position, the second positioning part disengages from the first positioning part; When the magnetic force generating unit generates an attractive magnetic force, the magnetic force generating unit drives the driven unit to move towards the stop surface and be located in the second position. The second positioning part engages with the first positioning part, and the driven unit restricts the rotation of the main shaft.

2. The power tool reverse torque suppression device as described in claim 1, wherein, The magnetic force generating unit can switch to a repulsive magnetic force. The driven unit includes a metal plate and a magnet. The metal plate is sleeved on the slide rail section and can be driven by the attractive magnetic force of the magnetic force generating unit to move towards the stop surface. The magnet and the second positioning part are disposed on the metal plate. When the magnetic force generating unit switches from the attractive magnetic force to the repulsive magnetic force, the magnet of the driven unit is pushed back by the repulsive magnetic force of the magnetic force generating unit, and the driven unit is reset from the second position to the first position.

3. The reverse torque suppression device for power tools as described in claim 1, wherein, The transmission unit has a motor that drives the main shaft to rotate. The main shaft has a first smooth section and a second smooth section. The first smooth section and the second smooth section are located on both sides of the slide rail section. The motor is pivotally connected to the first smooth section. The magnetic force generating unit passes through the first smooth section and is located between the motor and the driven unit.

4. The reverse torque suppression device for power tools as described in claim 3, wherein, The main shaft is provided with a retaining ring, which is fixed to the second smooth section. The driven unit includes a metal plate and an elastic member. The metal plate is sleeved on the slide rail section and can be driven by the magnetic attraction force of the magnetic force generating unit to move towards the stop surface. The second positioning part is provided on the metal plate. The two ends of the elastic member connect the metal plate and the retaining ring. When the magnetic force generating unit closes the magnetic attraction force, the metal plate is pulled away from the stop surface by the elastic member, and the driven unit is reset from the second position to the first position.

5. The reverse torque suppression device for power tools as described in claim 1, wherein, The transmission unit has a motor that drives the main shaft to rotate. The main shaft has a first smooth section and a second smooth section. The first smooth section and the second smooth section are located on both sides of the slide rail section. The motor is pivotally connected to the first smooth section. The magnetic force generating unit passes through the second smooth section, and the driven unit is located between the motor and the magnetic force generating unit.

6. The reverse torque suppression device for power tools as described in claim 5, wherein, The main shaft is provided with a retaining ring, which is fixed to the first smooth section. The driven unit includes a metal plate and an elastic member. The metal plate is sleeved on the slide rail section and can be driven by the magnetic attraction force of the magnetic force generating unit to move towards the stop surface. The second positioning part is provided on the metal plate. The two ends of the elastic member connect the metal plate and the retaining ring. When the magnetic force generating unit closes the magnetic attraction force, the metal plate is pulled away from the stop surface by the elastic member, and the driven unit is reset from the second position to the first position.

7. The reverse torque suppression device for power tools as described in claim 1, wherein, The first positioning part has multiple protrusions that protrude from the stop surface. The second positioning part has multiple limiting grooves. When the driven unit is in the second position, at least one protrusion is inserted into one of the limiting grooves.

8. The reverse torque suppression device for power tools as described in claim 7, wherein, The magnetic force generating unit has an electromagnetic coil module and a cover plate. The electromagnetic coil module has multiple slots. The first positioning part has multiple springs. The multiple springs and the multiple protrusions are respectively housed in the multiple slots. The cover plate is attached to one side of the electromagnetic coil module and closes the multiple slots. The cover plate has a stop surface. The stop surface is provided with multiple through holes corresponding to the positions of the multiple slots. The multiple protrusions are pushed out of the multiple through holes by the multiple springs.

9. The reverse torque suppression device for power tools as described in claim 1, wherein, The driven unit has a shaft hole, the plurality of limiting grooves surround the shaft hole, the slide rail section has a plurality of sliders surrounding the main shaft, and the inner edge of the shaft hole is provided with a plurality of grooves corresponding to and cooperating with the plurality of sliders.

Images