JP7383591B2 - Electric screwdriver and electric screwdriver torque control device - Google Patents

Description

TECHNICAL FIELD The present invention relates to structural improvements to hand tools, and in particular to an electric screwdriver and a torque control device for an electric screwdriver.

An electric screwdriver is a hand tool for tightening and loosening screws such as bolts and screws.The electric screwdriver is a hand tool used to tighten and loosen screws such as bolts and screws. It can be loosened and removed.

Conventional electric screwdrivers can adjust the tightening torque value, but it is necessary to adjust the rotational force depending on the material and hardness of the surface of the object to be attached, or the structural strength of the screw or bolt itself. If the rotational force is too strong, the surface of the object to be attached and the bolt itself will be damaged, while if the rotational force is too weak, the bolt may not be securely tightened to the surface of the object to be attached.

Specifically, when the user activates the electric screwdriver, the internal control board is started, and the motor is driven to engage a gearbox connected to a regulator that can set the tightening torque value of the electric screwdriver. and rotate it. The gearbox is further connected to a mechanical brake mechanism, and at the same time, the brake mechanism is connected to an output shaft unit that is a bit chuck of an electric screwdriver. When the electric screwdriver reaches a predetermined tightening torque value during operation, the mechanical brake mechanism is triggered and sends a signal to the control board to stop the rotation of the motor, thereby ensuring that each screw reaches the same predetermined tightening torque. Tightened with torque value.

In order to accurately detect the torque value of a screw being tightened, an electric screwdriver generally has a built-in detection device. Since the motor rotates at high speed during operation, the electric driver is filled with lubricating oil to ensure stable operation over a long period of time. However, since lubricating oil affects the accuracy of the detection device, one of the focuses of research and development in this field is how to isolate the lubricant from the detection device without affecting the operation of the electric screwdriver. It is.

Furthermore, the conventional electric screwdriver detection device uses a transmission module with a deformable structure to which a strain gauge is attached, and measures the amount of strain caused by the rotational drive of the transmission module in the deformable structure. The system measures the torque using a strain gauge and converts it into a tightening torque value, but since the existing transmission module and deformable structure are integrally molded, it is not possible to handle them separately during repair or maintenance. This has led to an increase in repair and maintenance costs.

Therefore, how to improve the above-mentioned problems is a current challenge in the industry.

Taiwan Patent No. I640756 Specification

The present invention has been made in view of the drawbacks of the prior art, and an object of the present invention is to provide an electric screwdriver and a torque control device for an electric screwdriver that has low maintenance costs.

To achieve the above object, the present invention is an electric screwdriver that includes a torque control device, a bit chuck, and a motor, and the torque control device includes at least a drive casing, a transmission module, a torque sleeve, and a torque control device. a strain gauge, the drive casing has opposing front and rear ends, the transmission module is rotatably installed within the drive casing, and the torque sleeve is connected to the drive casing. the at least one strain gauge is mounted on the torque sleeve; Each at least one strain gauge senses strain in the torque sleeve, the bit chuck is disposed at a forward end of the drive casing, the motor is disposed at a rear end of the drive casing, and the motor is disposed at a rear end of the drive casing. the motor shaft having a shaft, the motor shaft passing through the torque sleeve and being connected to the transmission module, and driving the transmission module to rotate the bit chuck relative to the drive casing; It is characterized by being driven as follows.

The transmission module includes at least one protrusion, each at least one protrusion has two first contact surfaces parallel to the rotation axis of the transmission module, and the torque sleeve includes at least one protrusion. one recess, each at least one recess having two second contact surfaces parallel to the rotational axis of the transmission module, and when the transmission module and the torque sleeve are coupled, the At least one protrusion and the at least one recess are fitted together, and the two first contact surfaces and the two second contact surfaces are in contact with each other, respectively.

The transmission module has a peripheral wall, the at least one protrusion is formed on the peripheral wall to protrude along the axial direction of the transmission module, the torque sleeve has a front connection part, and the torque sleeve has a front connection part, At least one recess is formed on the front coupling part, and the peripheral wall surrounds the front coupling part when the transmission module and the torque sleeve are coupled.

The torque sleeve includes a front coupling part, a rear coupling part, and a sensing part, the front coupling part being removably coupled to the rear of the transmission module, and the rear coupling part being fixed to the drive casing. and located behind the front connection part, the detection part connects the front connection part and the rear connection part, and the thickness of the detection part is greater than the thickness of the front connection part and the rear connection part. The at least one strain gauge is also thin, and the at least one strain gauge is installed on the outer surface of the sensing portion.

The detection unit further includes a detection wall and a plurality of long holes, and the plurality of long holes are formed on the detection wall at intervals so as to penetrate through the detection wall, and the plurality of long holes are formed at intervals on the detection wall so as to penetrate the detection wall. The at least one strain gauge extends in the circumferential direction and is installed between any of the plurality of adjacent elongated holes.

The electric screwdriver torque control device further includes a sealing ring, the sealing ring being fixed to the outer circumferential surface of the torque sleeve and located between the at least one strain gauge and the transmission module. shall be.

The electric screwdriver torque control device further includes an oil seal ring, the oil seal ring being fixed within the torque sleeve and located between the at least one strain gauge and the transmission module. shall be.

As mentioned above, the advantage of the present invention is that the transmission module and torque sleeve are connected in a separable manner, so that only the parts that need to be replaced need to be replaced during repair or maintenance. Since there is no need to replace the torque sleeve at the same time, maintenance costs can be significantly reduced.
Furthermore, by installing a sealing ring and an oil seal ring, the strain gauge is isolated from the lubricating oil inside the electric screwdriver, which prevents the lubricating oil from adhering to it and causing no adverse effects. Durability and precision can be improved.

1 is a perspective view showing a bit chuck, a motor, and a torque control device of an electric screwdriver according to the present invention. 1 is an exploded view showing a bit chuck, a motor, and a torque control device of an electric screwdriver according to the present invention. 1 is a side sectional view showing a bit chuck, a motor, and a torque control device of an electric screwdriver according to the present invention. FIG. 1 is a perspective view of a torque control device according to the present invention. FIG. 1 is an exploded view of a torque control device according to the present invention. FIG. 3 is a perspective view showing a torque sleeve, a seal ring, and an oil seal ring of the torque control device according to the present invention. 1 is a side sectional view of a torque control device according to the present invention. FIG. 3 is a side sectional view showing a torque sleeve of the torque control device according to the present invention.

As shown in FIGS. 1 to 3, the present invention is an electric screwdriver that includes a bit chuck 10, a motor 20, and a torque control device 30. The bit chuck 10 and the motor 20 are respectively disposed at the tip and the end of the torque control device 30, and the motor 20 has a motor shaft 21. In the following description, the side where the bit chuck 10 is placed will be referred to as the front, and the side where the motor 20 is placed will be referred to as the rear.

Further, as shown in FIGS. 3 to 5, the torque control device 30 includes a drive casing 31, a transmission module 32, a torque sleeve 33, at least one strain gauge 34, and optionally includes a sealing ring 35 and an oil A seal ring 36 and/or at least one thrust bearing 37 may also be included.

The drive casing 31 has a front end and a rear end facing each other, and the front end is connected to the bit chuck 10 and the rear end is connected to the motor 20. The transmission module 32 is rotatably installed within the drive casing 31 and is used to drive the bit chuck 10 to rotate relative to the drive casing 31. In this embodiment, the transmission module 32 includes a planetary gear mechanism.

The transmission module 32 includes a peripheral wall 321 and at least one convex part 322, and the at least one convex part 322 is formed on the peripheral wall 321 and protrudes along the axial direction of the transmission module 32. extend like that. In this embodiment, a plurality of convex portions 322 are included, and the overall shape is approximately crown-shaped, and each convex portion 322 has two first contact surfaces parallel to the axial direction of the transmission module 32. has.

Subsequently, as shown in FIGS. 1, 6 and 7, the torque sleeve 33 is fixedly installed in the drive casing 31 and is removably connected to the transmission module 32. Deformation occurs due to the rotational drive of. In this embodiment, the torque sleeve 33 is a cylindrical sleeve, but its outer shape is not limited to the cylindrical shape.
The motor shaft 21 of the motor 20 is installed through the torque sleeve 33 and is drivingly connected to the transmission module 32, and by driving the transmission module 32, the bit chuck 10 is moved relative to the drive casing 31. It is driven so that it rotates.

The torque sleeve 33 includes a front connection part 331 removably connected to the rear of the transmission module 32, a rear connection part 332 located behind the front connection part 331, and a front connection part 331 and a rear connection part. 332, and a detection unit 333 located between the detection unit 332 and

In this embodiment, the torque sleeve 33 is a cylindrical sleeve having both ends penetrated, and the thickness of the detection part 333 is thinner than the thickness of the front connection part 331 and the rear connection part 332. Further, the detection section 333 includes a detection wall 3331 and a plurality of long holes 3332, and the thickness of the detection section 333 mentioned above refers to the thickness of the detection wall 3331, and the plurality of long holes 3332 are , are formed on the detection wall 3331 at intervals so as to penetrate the detection wall 3331, and extend in the circumferential direction of the detection wall 3331.

As shown in FIG. 5, the torque sleeve 33 includes at least one recess 3310. In this embodiment, a plurality of recesses 3310 are included, and the number matches the number of convex parts 322 of the transmission module 32. Specifically, the recess 3310 is formed on the front connecting part 331 so as to be recessed along the axial direction of the transmission module 32, but the structure is not limited thereto.
Each of the recesses 3310 has two second contact surfaces parallel to the axial direction of the transmission module 32, and when the transmission module 32 is connected to the torque sleeve 33, the peripheral wall 321 The two first abutting surfaces of each of the protrusions 322 abut the second abutting surfaces of the concave portion 3310 surrounding the front connecting portion 331 . Since the first contact surface of the convex portion 322 and the second contact surface of the recess 3310 are parallel to the axial direction of the transmission module 32, when the transmission module 32 rotates, the first contact surface of the recess 3310 The torque sleeve 33 is torsionally deformed by the normal force applied to the two contact surfaces.

As shown in FIG. 6, each strain gauge 34 is installed on the torque sleeve 33 to detect and record the strain of the torque sleeve 33. In this embodiment, the number of strain gauges 34 is plural, but is not particularly limited to this. The plurality of strain gauges 34 are arranged on the outer circumferential wall surface of the detection section 333, and more specifically, each strain gauge 34 is arranged between any adjacent elongated holes 3332. Thereby, the elongated holes 3332 and the strain gauges 34 are arranged alternately on the detection wall 3331.

As shown in FIGS. 6 to 8, in this embodiment, a front connection part 331 of the torque sleeve 33 is connected to an internal gear (not shown) inside the transmission module 32, and a rear connection part 331 of the torque sleeve 33 is connected to an internal gear (not shown) inside the transmission module 32. A portion 332 is fixed within the drive casing 31 by a plurality of screws.
When the planetary gear mechanism inside the transmission module 32 reaches a certain tightening torque value, the sun gear of the planetary gear mechanism drives the internal gear to rotate, and the torque sleeve 33 connected to the internal gear When the torque sleeve 33 starts to rotate, it does not rotate because the rear coupling part 332 of the torque sleeve 33 is fixed to the drive casing 31, and there is no relative rotation between the front coupling part 331 and the rear coupling part 332. Movement occurs. As a result, torsional deformation occurs in the sensing portion 333 between the front connecting portion 331 and the rear connecting portion 332.

Then, the strain gauge 34 on the detection unit 333 detects the torsional deformation of the detection unit 333, and since the strain gauge 34 is electrically connected to the signal detection device 40, Then, the torsional deformation recorded by the strain gauge 34 is converted into a signal and transmitted to an external computer (not shown). In this embodiment, the signal detection device 40 is installed inside the torque sleeve 33, but the invention is not limited thereto.

The sealing ring 35 is fixed on the outer circumferential surface of the torque sleeve 33 , closely contacts the inner circumferential wall surface of the drive casing 31 , and is located between the strain gauge 34 and the transmission module 32 .
The oil seal ring 36 is fixed within the torque sleeve 33 and is located between the strain gauge 34 and the transmission module 32. In this embodiment, the oil seal ring 36 is also attached to the motor shaft 21 of the motor 20 at the same time. The installation of the seal ring 35 and the oil seal ring 36 prevents the lubricating oil in the transmission module 32 from flowing into the installation space of the strain gauge 34.

As shown in FIG. 7, the at least one thrust bearing 37 is installed within the drive casing 31. In this embodiment, the number of the at least one thrust bearing 37 is two, and the two thrust bearings 37 are respectively mounted on the transmission module 32 so as to be arranged in the front and back, and each An inner peripheral surface and an outer peripheral surface of the thrust bearing 37 abut against the transmission module 32 and the drive casing 31, respectively.

Furthermore, as shown in FIGS. 3, 6, and 7, when using the present invention, the signal detection device 40 can be connected to an external computer (not shown). Using the computer, the tightening torque value of the motor 20 can be set in advance. Note that the signal detection device 40 can simultaneously transfer data such as stop commands, machining processes, and counting management.

During actual operation, the user starts the electric screwdriver, operates the motor 20, and as the bit chuck 10 rotates, the bolt or screw is screwed into the object to be tightened. The load torque applied to the bit chuck 10 gradually transfers to the torque sleeve 33, and then the torque sleeve 33 is twisted and torsional deformation occurs. When the torsional deformation is detected by the strain gauge 34, an external signal is transmitted via the signal detection device 40. Transfer signals to a computer or controller. When the degree of torsional deformation detected by the strain gauge 34 reaches a predetermined value, a stop command is issued from the computer or controller, stopping the operation of the motor 20 and stopping the electric screwdriver. In this way, the fastening work with a fixed tightening torque value is completed.

As described above, the present invention has at least the following advantages and advantages.

Part 1: Since the transmission module 32 and torque sleeve 33 according to the present invention are separably connected, only the parts that need to be replaced can be replaced during repair or maintenance. Since there is no need to replace them together, maintenance costs can be significantly reduced. Furthermore, by installing the sealing ring 35 and the oil seal ring 36, the strain gauge 34 is isolated from the lubricating oil inside the electric screwdriver, so the lubricating oil will not adhere to it and will not have any adverse effects. The durability and accuracy of the strain gauge 34 can be improved.

Second, as shown in FIG. 3, by installing a strain gauge 34 that can detect and record the amount of torsional deformation, it becomes possible to record data of each machining process. Furthermore, by compiling and examining the results and errors that occur during each process, and organizing this data, we can combine it with various equipment in the factory to achieve the objectives of Industry 4.0.

Third, the tightening torque value feedback allows the user to control the tightening torque value for a single electric screwdriver via a computer or controller. In other words, by adjusting the tightening torque value of each electric screwdriver in each machining process, it is possible to appropriately respond to different attachment targets.Furthermore, by controlling the computer, each electric screwdriver can be quickly and directly adjusted. Since the tightening torque value can be adjusted, a worker using an electric screwdriver does not have to take the trouble of preparing multiple electric screwdrivers to correspond to different tightening torque values.

Fourth, by using the torque sleeve 33 as a tightening torque value detection device, wear of the members during use of the electric screwdriver can be reduced, so the service life of the electric screwdriver can be improved.

10 Bit chuck 20 Motor 21 Motor shaft 30 Torque control device 31 Drive casing 32 Transmission module 321 Peripheral wall 322 Convex portion 33 Torque sleeve 331 Front connection portion 3310 Recessed portion 332 Rear connection portion 333 Detection portion 3331 Detection wall 3332 Long hole 34 Strain gauge 35 Sealing Ring 36 Oil seal ring 37 Thrust bearing 40 Signal detection device

Claims (8)

A torque control device for an electric screwdriver connected to a bit chuck, comprising a drive casing, a transmission module, a torque sleeve, and at least one strain gauge,
one end of the drive casing is used to connect with the bit chuck,
The transmission module is rotatably installed within the drive casing and is used to drive the bit chuck to rotate relative to the drive casing;
The torque sleeve is fixedly installed in the drive casing and is removably connected to the transmission module, and is deformed by rotational driving of the transmission module,
the at least one strain gauge is disposed on the torque sleeve, each at least one strain gauge sensing strain in the torque sleeve ;
The transmission module includes at least one convex part, and each at least one convex part has two first contact surfaces parallel to the axial direction of the transmission module,
The torque sleeve includes at least one recess, and each at least one recess has two second contact surfaces parallel to the axial direction of the transmission module,
When the transmission module and the torque sleeve are connected, the at least one convex portion and the at least one concave portion are fitted together, and the two first abutment surfaces and the two second abutment surfaces are respectively A torque control device for an electric screwdriver characterized by abutting . The transmission module has a peripheral wall, and the at least one protrusion is formed on the peripheral wall to protrude along the axial direction of the transmission module,
The torque sleeve has a front coupling part, the at least one recess is formed on the front coupling part, and the peripheral wall surrounds the front coupling part when the transmission module and the torque sleeve are coupled. The torque control device for an electric screwdriver according to claim 1 . The torque sleeve includes a front connection part, a rear connection part, and a detection part,
the front connection part is removably connected to the rear of the transmission module;
The rear connection part is fixed to the drive casing and is located at the rear of the front connection part,
The sensing portion connects the front connecting portion and the rear connecting portion, the thickness of the sensing portion is thinner than the thickness of the front connecting portion and the rear connecting portion, and the at least one strain gauge connects the front connecting portion and the rear connecting portion. The torque control device for an electric screwdriver according to claim 1, wherein the torque control device is installed on an outer surface. The detection unit further includes a detection wall and a plurality of long holes, and the plurality of long holes are formed on the detection wall at intervals so as to penetrate through the detection wall, and the plurality of long holes are formed at intervals on the detection wall so as to penetrate the detection wall. The torque control device for an electric screwdriver according to claim 3 , wherein the at least one strain gauge extends in the circumferential direction and is installed between any of the plurality of adjacent elongated holes. The electric screwdriver torque control device further includes a sealing ring, the sealing ring being fixed to the outer circumferential surface of the torque sleeve and located between the at least one strain gauge and the transmission module. The torque control device for an electric screwdriver according to any one of claims 1 to 4 . The electric screwdriver torque control device further includes an oil seal ring, the oil seal ring being fixed within the torque sleeve and located between the at least one strain gauge and the transmission module. The torque control device for an electric screwdriver according to any one of claims 1 to 4 . An electric screwdriver, comprising a torque control device, a bit chuck, and a motor,
The torque control device includes a drive casing, a transmission module, a torque sleeve, and at least one strain gauge, the drive casing having opposing front and rear ends, and the transmission module having opposite front and rear ends. The torque sleeve is rotatably installed in the drive casing, and the torque sleeve is fixed in the drive casing and removably coupled to the transmission module, and is deformed by rotational driving of the transmission module, and the torque sleeve one strain gauge is placed on the torque sleeve, each at least one strain gauge sensing strain in the torque sleeve;
The transmission module includes at least one convex part, and each at least one convex part has two first contact surfaces parallel to the axial direction of the transmission module,
The torque sleeve includes at least one recess, and each at least one recess has two second contact surfaces parallel to the axial direction of the transmission module,
When the transmission module and the torque sleeve are connected, the at least one convex portion and the at least one concave portion are fitted together, and the two first abutment surfaces and the two second abutment surfaces are respectively abutting,
the bit chuck is located at a front end of the drive casing;
The motor is disposed at the rear end of the drive casing and has a motor shaft, which extends through the torque sleeve and is drivingly connected to the transmission module. An electric screwdriver characterized in that the bit chuck is driven to rotate with respect to the drive casing by driving the bit chuck. The torque control device further includes an oil seal ring, which is fixed within the torque sleeve and mounted on the motor shaft, and which is connected between the at least one strain gauge and the transmission module. The electric screwdriver according to claim 7 , wherein the electric screwdriver is located at.

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