TWM620076U - Electric screwdriver and torque control device of electric screwdriver - Google Patents

Abstract

This creation proposes an electric screwdriver and a torque control device for electric screwdrivers. The electric screwdriver has a torque control device, a tool head, and a motor. The torque control device has a drive housing, a transmission module, and a torsion sleeve. The drive housing has a front end and a rear end opposite to each other. The transmission module is rotatably arranged in the drive housing. The torsion sleeve is fixed in the drive housing, and is detachably connected to the transmission module, and can be driven by the transmission module to produce deformation. A strain gauge is provided on the torsion sleeve. The motor has a transmission shaft to drive the transmission module, and thereby drive the tool head to rotate relative to the drive housing. The transmission module and the torsion sleeve in this creation are separable, so during adjustment or maintenance, there is no need to replace the transmission module and the torsion sleeve together, which greatly saves costs.

Description

Electric screwdriver and torque control device of electric screwdriver

This creation is about the structural improvement of a hand tool, especially an electric screwdriver and the torque control device of an electric screwdriver.

An electric screwdriver is a hand tool for disassembling and disassembling bolts or screws and other locking elements. It can quickly disassemble and disassemble the bolts or screws on the surface to be processed through the rotation of the internal rotating motor.

However, the electric screwdriver of the prior art has a structure that can adjust its torque, because the electric screwdriver needs to adjust its rotation force according to the material and hardness of the surface to be processed, and the structural strength of the screw or bolt itself, so as to avoid the force. When the strength is too strong, the processing surface and the structure of the bolt itself are damaged, or when the force is too weak, the electric screwdriver may not be able to firmly set the bolt on the processing surface.

Specifically, when the user starts the electric screwdriver, it will trigger its internal control board, and then drive the motor to drive a gearbox to rotate, and the gearbox is also connected to a torque adjustment device that can set the electric screwdriver On the other hand, the gearbox is further connected to a mechanical brake mechanism, which is also connected to the output shaft group, which is the tool head of the electric screwdriver. When the electric screwdriver reaches its upper limit of torque during operation, the mechanical brake mechanism will be triggered, and a message will be sent back to the control board to stop the motor, so that each screw can have the same torque.

In order to accurately sense the torque on the screw, a sensing device is provided in the electric screwdriver. At the same time, the motor will rotate at a high speed during operation, so the electric screwdriver must have lubricating oil in order to make the motor long Stable operation for a long time. However, lubricating oil affects the accuracy of the sensing device. Therefore, how to isolate the lubricating oil from the sensing device without affecting the operation of the electric screwdriver is one of the focuses of research and development in this field.

On the other hand, the sensing devices of electric screwdrivers in the prior art are all connected to a transmission module with an elastic body, and a strain gauge is arranged on the elastic body. The transmission module drives the elastic body to deform, and then strain Calculate the torsion force based on the amount of deformation measured by the gauge. However, the existing transmission module is integrally formed with the elastic body. Therefore, the transmission module and the elastic body must be removed together during adjustment or maintenance. The transmission module or the elastic body cannot be adjusted separately, resulting in adjustment and maintenance. The cost is too high.

In view of this, proposing a better improvement plan is a problem that the industry needs to solve urgently.

The main purpose of this creation is to propose an electric screwdriver and a torque control device for an electric screwdriver, which can have a lower maintenance cost.

To achieve the above purpose, the electric screwdriver proposed in this creation has: a torque control device, which has: a drive housing with a front end and a rear end opposed to each other; a transmission module, which is rotatably arranged on the In the drive housing; a torsion sleeve, which is fixed in the drive housing, is detachably connected to the transmission module, and can be driven by the transmission module to produce deformation; and at least one strain gauge, which is arranged in On the torsion sleeve, each of the at least one strain gauge can detect the deformation of the torsion sleeve; a tool head is arranged on the front end of the drive housing; a motor is arranged on the drive housing Backend, and has: A transmission shaft penetrates the torsion sleeve and is connected to the transmission module; the transmission shaft can drive the transmission module and thereby drive the tool head to rotate relative to the drive housing.

In the torque control device for an electric screwdriver as described above: the transmission module has at least one protrusion, and each of the at least one protrusion has two first abutting surfaces, and each of the first abutment surfaces and the transmission module The rotation axis is parallel; the torsion sleeve has at least one concave portion, each of the at least one concave portion has two second abutting surfaces, each of the second abutting surfaces is parallel to the rotation axis of the transmission module; and when the transmission module is connected When the sleeve is twisted, the at least one protrusion is fitted into the at least one concave portion, and the two first abutting surfaces respectively abut against the second abutting surfaces.

In the torque control device of the electric screwdriver as described above: the transmission module has a ring wall, and the at least one protrusion is located on the ring wall and protrudes along the axis of the transmission module; the torsion sleeve has A front connecting part, and the at least one concave part is formed on the front connecting part; and when the transmission module is connected to the torsion sleeve, the ring wall surrounds the front connecting part.

In the torque control device for an electric screwdriver as mentioned above, the torsion sleeve has: a front connection part, which is detachably connected to the rear of the transmission module; a rear connection part, which is fixedly provided with the drive housing and is located The rear of the front connecting portion; a sensing portion that connects the front connecting portion and the rear connecting portion, and the thickness of the sensing portion is smaller than the thickness of the front connecting portion, and the thickness of the sensing portion is smaller than that of the rear connecting portion And the at least one strain gauge is arranged on the outer wall surface of the sensing part.

In the torque control device of the electric screwdriver as described above, the sensing portion further includes a sensing wall and a plurality of elongated holes. The elongated holes are formed on the sensing wall at intervals and are formed along the It extends in the circumferential direction, and each of the at least one strain gauge is arranged between any two adjacent elongated holes.

The torque control device of the electric screwdriver as mentioned above further has a sealing ring fixed on the outer peripheral surface of the torsion sleeve and located between the at least one strain gauge and the transmission module.

As mentioned above, the electric screwdriver further has an oil seal, which is fixed in the torsion sleeve and sleeved on the transmission shaft, and is located between the at least one strain gauge and the transmission module.

Therefore, the advantage of this creation is that the transmission module 32 and the torsion sleeve 33 are separable, so when adjusting or repairing, only need to replace the corresponding part, and there is no need to replace the transmission module 32 and the torsion sleeve 33 together. , A substantial cost savings. On the other hand, by preventing the lubricating oil in the transmission module 32 from flowing to the strain gauge 34 through the seal ring 35 and the oil seal 36, the durability and accuracy of the strain gauge 34 can be improved without being affected by the lubricating oil.

10: Tool head

20: Motor

21: drive shaft

30: Torque control device

31: Drive housing

32: Transmission module

321: Ring Wall

322: Bump

33: Torsion sleeve

331: Front connection part

3310: recess

332: Rear connection

333: Sensing Department

3331: Sensing Wall

3332: Long hole

34: Strain gauge

35: sealing ring

36: oil seal

37: Rotating bearing

40: Signal sensing device

Figure 1 is a three-dimensional schematic diagram of the tool head, motor, and torque control device of the electric screwdriver created.

Figure 2 is a three-dimensional exploded view of the tool head, motor, and torque control device of the electric screwdriver created.

Figure 3 is a schematic cross-sectional view of the tool head, motor, and torque control device of the electric screwdriver created.

Figure 4 is a three-dimensional schematic diagram of the torque control device created.

Figure 5 is a three-dimensional exploded view of the torque control device created.

Figure 6 is a three-dimensional schematic diagram of the torsion sleeve, seal ring, and oil seal of the torque control device created.

Figure 7 is a schematic cross-sectional view of the torque control device created.

Figure 8 is a schematic cross-sectional view of the torsion sleeve of the torque control device created.

Please refer to Figure 1 to Figure 3 first. This creation proposes an electric screwdriver, which has a tool head 10, a motor 20, and a torque control device 30. The tool head 10 and the motor 20 are respectively arranged at the front and rear ends of the torque control device 30. The motor 20 has a transmission shaft 21. In the following description, the position where the tool head 10 is located is the front, and the position where the motor 20 is located is the rear.

Then please refer to Figure 3 to Figure 5. The torque control device 30 has a drive housing 31, a transmission module 32, a torsion sleeve 33, and at least one strain gauge 34, and may optionally have a seal ring 35, an oil seal 36, and/or at least A rotating bearing 37.

The driving housing 31 has a front end and a rear end opposite to each other. The front end of the driving housing 31 is connected to the tool head 10 and the rear end is connected to the motor 20. The transmission module 32 is rotatably disposed in the drive housing 31 and can be used to drive the tool head 10 to rotate relative to the drive housing 31. In this embodiment, the transmission module 32 includes a planetary gear set.

The transmission module 32 further has a ring wall 321 and at least one protrusion 322. The at least one protrusion 322 is located on the ring wall 321 and protrudes along the axis of the transmission module 32. In this embodiment, there are a plurality of bumps 322, so they are roughly crowned. Each protrusion 322 has two first abutting surfaces, and each first abutting surface is parallel to the rotation axis of the transmission module 32.

Please refer to Figure 1, Figure 6, and Figure 7. The torsion sleeve 33 is fixed in the drive housing 31 and is detachably connected to the transmission module 32 so that it can be driven by the transmission module 32 to produce deformation. In this example, the tool head 10, the transmission module 32, the torsion sleeve 33, and the motor 20 are arranged in sequence, but the relative positions of the transmission module 32 and the torsion sleeve 33 are not limited to this. In addition, in this embodiment, the torsion sleeve 33 is a cylindrical sleeve, but its shape is not limited to a cylinder. The transmission shaft 21 of the motor 20 penetrates through the torsion sleeve 33 and is connected to the transmission module 32 to drive the transmission module 32 to drive the tool head 10 to rotate relative to the drive housing 31.

The torsion sleeve 33 further includes a front connecting portion 331, a rear connecting portion 332 and a sensing portion 333. The front connecting part 331 is arranged behind the transmission module 32, the rear connecting part 332 is arranged behind the front connecting part 331, and the sensing part 333 is connected between the front connecting part 331 and the rear connecting part 332.

In this embodiment, the torsion sleeve 33 can be a cylindrical sleeve with both ends passing through, and the thickness of the sensing portion 333 is smaller than that of the front connecting portion 331, and the thickness of the sensing portion 333 is also smaller than that of the rear connecting portion 332. thickness. The sensing portion 333 includes a sensing wall 3331 and a plurality of long holes 3332. The aforementioned thickness of the sensing portion 333 refers to the thickness of the sensing wall 3331, and the long holes 3332 are formed in the sensing wall 3331 at intervals. And extend along the circumferential direction of the sensing wall 3331.

Then please refer to Figure 5 together. The torsion sleeve 33 has at least one recess 3310, and this embodiment has a plurality of recesses 3310. The number of the recesses 3310 is equal to the number of the bumps 322 of the transmission module 32. Specifically, the recess 3310 is formed on the front connecting portion 331 and is recessed in a direction perpendicular to the rotation axis of the transmission module 32, but its structure is not limited to this. Each recess 3310 has two second abutment surfaces, and each second abutment surface is parallel to the rotation axis of the transmission module 32. When the transmission module 32 is connected to the torsion sleeve 33, the ring wall 321 surrounds the front connecting portion, and each convex block 322 is respectively fitted into a concave portion 3310, and the two first abutting surfaces of each convex block 322 respectively abut against On the second abutment surface of the recess 3310. Since the first abutment surface of the convex block 322 and the second abutment surface of the concave portion 3310 are parallel to the rotation axis of the transmission module 32, the second abutment applied to the concave portion 3310 can be applied when the transmission module 32 rotates. The positive force of the face causes the torsion sleeve 33 to twist.

Then please refer to Figure 6. Each strain gauge 34 is arranged on the torsion sleeve 33 and can be used to detect and record the deformation of the torsion sleeve 33. In this embodiment, the number of strain gauges 34 is plural, but it is not limited to this. The iso-strain gauge 34 is arranged on the outer wall surface of the sensing portion 333. More precisely, each strain gauge 34 is arranged between any two adjacent elongated holes 3332, so that the elongated holes 3332 and the strain gauges 34 are staggered with each other. Located on the sensing wall 3331.

Then please refer to Figure 6 to Figure 8. In this embodiment, the front connecting portion 331 of the torsion sleeve 33 is fixed to the ring gear (not shown in the figure) in the transmission module 32, and the rear connecting portion 332 of the torsion sleeve 33 is transparent. A plurality of bolts are screwed and fixed to the inside of the drive housing 31, and when the planetary gear set inside the transmission module 32 is twisted to a certain torque, the sun gear of the planetary gear set cannot smoothly drive the ring gears to rotate together, and then The ring gear starts to drive the front end of the torsion sleeve 33 to be twisted together. Since the rear end of the torsion sleeve 33 is fixed by the drive housing 31, the front connecting portion 331 and the rear connecting portion 332 will rotate relative to each other, and the sensing portion 333 located between the front connecting portion 331 and the rear connecting portion 332 will rotate Reversal occurred.

At this time, the strain gauge 34 provided on the sensing portion 333 can sense the amount of deformation of the sensing portion 333. Since the strain gauge 34 is electrically connected to a signal sensing device 40, and the value recorded by the strain gauge 34 is transmitted to an external computer through the signal sensing device 40, in this embodiment, the signal sensing device 40 can be installed in Twist the inside of the sleeve 33, but its setting position is not limited to this.

The sealing ring 35 is fixed on the outer peripheral surface of the torsion sleeve 33 and abuts against the inner wall surface of the driving housing 31, and the sealing ring 35 is located between the strain gauge 34 and the transmission module 32. The oil seal 36 is fixed in the torsion sleeve 33 and is located between the strain gauge 34 and the transmission module 32, and in this embodiment, the oil seal 36 is also sleeved on the transmission shaft 21 of the motor 20. Through the sealing ring 35 and the oil seal 36, the lubricating oil in the transmission module 32 can be prevented from flowing to the strain gauge 34.

Then please refer to Figure 7. The at least one rotating bearing 37 is arranged in the drive housing 31, and in this embodiment, the number of the at least one rotating bearing 37 is two, and the two rotating bearings 37 are respectively arranged forward and backward and sleeved on the transmission module 32 The inner surface and the outer surface of each rotating bearing 37 are respectively attached to the inner wall surface of the transmission module 32 and the drive housing 31.

Please refer to Figure 3, Figure 6, and Figure 7. When using this creation, the signal sensing device 40 can be connected to an external computer (not shown in the figure), and the upper limit of the torque transmission of the motor 20 can be preset through the computer. This signal sensing device can also transmit the braking and processing processes. And count and other information.

In actual operation, when the user starts the electric screwdriver, the motor starts to run and a bolt or screw is gradually locked into the object to be processed through the rotation of the tool head 10, the torque received by the tool head 10 will gradually transfer to torsion The sleeve 33 and make the twisting sleeve 33 start to twist slightly. This twist After the transformation variable is generated, it will be recorded by the strain gauge 34 and sent back to the external controller or computer through the signal sensing device 40. When the amount recorded by the strain gauge 34 reaches the preset value before use, the controller Or the computer will stop the motor 20, and then stop the electric screwdriver to complete the entire twisting behavior.

In summary, the advantages of this creation are as follows:

First, the transmission module 32 and the torsion sleeve 33 in this creation are separable. Therefore, when adjusting or repairing, you only need to remove the corresponding part. There is no need to combine the transmission module 32 with the torsion sleeve 33. Replacement, greatly saving costs. On the other hand, by preventing the lubricating oil in the transmission module 32 from flowing to the strain gauge 34 through the seal ring 35 and the oil seal 36, the durability and accuracy of the strain gauge 34 can be improved without being affected by the lubricating oil.

Second, please refer to Figure 3. By installing a strain gauge 34 that can detect and record the deformation variables, this creation can record the data in each processing process, thereby judging and integrating the data generated by each processing Results, errors, etc., through the aggregation of this data, this creation can be further matched with various facilities in the factory to achieve the purpose of Industry 4.0.

Third, through the feedback of the torque value, the user can control the torque value transmitted by a single electric screwdriver through the controller or computer. In other words, the user can adjust the torque upper limit of each electric screwdriver in each processing process. The purpose of adapting to different processing objects more appropriately has been achieved. At the same time, operators using electric screwdrivers no longer need to prepare multiple electric screwdrivers to use electric screwdrivers with different torques, and can be controlled by a computer to quickly and directly adjust each The current torque limit of an electric screwdriver.

Fourth, the use of the torsion sleeve 33 as a device for detecting torque can reduce the equipment wear rate of the electric screwdriver during use, and thus can increase the service life of a single electric screwdriver.

31: Drive housing

32: Transmission module

321: Ring Wall

322: Bump

33: Torsion sleeve

331: Front connection part

3310: recess

332: Rear connection

40: Signal sensing device

Claims (9)

A torque control device of an electric screwdriver is used to connect a tool head, and the torque control device of the electric screwdriver has: a drive housing, one end of which is used to connect the tool head; a transmission module, which is rotatably arranged In the drive housing, and used to drive the tool head to rotate relative to the drive housing; a torsion sleeve, which is fixed in the drive housing, and is detachably connected to the transmission module, and can be received by the transmission module And at least one strain gauge is arranged on the torsion sleeve, and each of the at least one strain gauge can detect the deformation of the torsion sleeve. The torque control device for an electric screwdriver according to claim 1, wherein: the transmission module has at least one protrusion, each of the at least one protrusion has two first abutting surfaces, and each of the first abutment surfaces is connected to the transmission The rotation axis of the module is parallel; the torsion sleeve has at least one concave portion, each of the at least one concave portion has two second abutment surfaces, each of the second abutment surfaces is parallel to the rotation axis of the transmission module; and when the transmission is When the module is connected to the torsion sleeve, the at least one protrusion is fitted into the at least one recess, and the two first abutting surfaces respectively abut against the second abutting surfaces. The torque control device for an electric screwdriver according to claim 2, wherein: the transmission module has a ring wall, and the at least one protrusion is located on the ring wall and protrudes along the axis of the transmission module; the torsion The sleeve has a front connecting portion, and the at least one concave portion is formed on the front connecting portion; and when the transmission module is connected to the torsion sleeve, the ring wall surrounds the front connecting portion. The torque control device for an electric screwdriver according to claim 1, wherein the torsion sleeve has: A front connection part, which is detachably connected to the rear of the transmission module; a rear connection part, which is fixed to the drive housing and is located behind the front connection part; a sensing part, which connects the front connection part and The rear connecting portion, and the thickness of the sensing portion is smaller than the thickness of the front connecting portion, the thickness of the sensing portion is smaller than the thickness of the rear connecting portion, and the at least one strain gauge is disposed on the outer wall surface of the sensing portion superior. The torque control device for an electric screwdriver according to claim 4, wherein the sensing portion further includes a sensing wall and a plurality of elongated holes, and the elongated holes are formed in the sensing wall at intervals and are formed along the sensing wall. The measuring wall extends in the circumferential direction, and each of the at least one strain gauge is arranged between any two adjacent elongated holes. The torque control device for an electric screwdriver according to any one of claims 1 to 5, further comprising a sealing ring fixed on the outer peripheral surface of the torsion sleeve and located between the at least one strain gauge and the transmission Between modules. According to the torque control device for an electric screwdriver according to any one of claims 1 to 5, it further has an oil seal, the oil seal is fixed in the torsion sleeve and located between the at least one strain gauge and the transmission module between. An electric screwdriver, which has: a torque control device, which has: a drive housing with a front end and a rear end opposed to each other; a transmission module, which is rotatably arranged in the drive housing; and a torsion sleeve A cylinder, which is fixed in the drive housing, is detachably connected to the transmission module, and can be driven by the transmission module to produce deformation; and at least one strain gauge, which is arranged on the torsion sleeve, and Each of the at least one strain gauge can detect the deformation of the torsion sleeve; a tool head is arranged at the front end of the drive housing; A motor, which is arranged at the rear end of the drive housing, and has: a transmission shaft that penetrates the torsion sleeve and is connected to the transmission module; the transmission shaft can drive the transmission module, And thereby drive the tool head to rotate relative to the drive housing. The electric screwdriver according to claim 8, wherein the electric screwdriver further has: an oil seal fixed in the torsion sleeve and sleeved on the transmission shaft, and located between the at least one strain gauge and the transmission module between.

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