Torque detection device for power tools

Abstract

To provide a torque detector for a power tool including an external housing, a power structure, a protective cover, an inner shell cover, a bearing set, and a torque sensor.SOLUTION: A power structure is set in en external housing and includes a power body and a drive shaft. A protective cover is engaged in the power body. A front bearing of the bearing set is set between the protective cover and the inner shell cover and a back bearing is set between the inner shell cover and the external housing. The torque sensor is set on the inner shelf cover and provides an accurate torque value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to power tools and, more particularly, to torque sensing devices for power tools. [Background technology]

[0002] Currently, power tools equipped with torque sensors can detect torque and transmit a signal when a predetermined torque is reached, controlling the power tool to stop operation. Furthermore, because torque sensors in typical power tools are typically installed on the transmission mechanism, the torque sensor is left rotating for long periods of time as the transmission mechanism operates, which can cause problems such as broken wires and poor contact, affecting electrical connections and resulting in damage to the power tool. Furthermore, when the power tool is in operation, vibrations or deformations can occur in the transmission mechanism connecting the tool head, further affecting the torque value detected by the installed torque sensor and reducing the accuracy of the torque sensor.

[0003] In view of this, the inventors have conducted extensive research into the above-mentioned prior art, and at the same time have applied academic theory to make efforts to solve the above-mentioned problems, thereby achieving their goal of improvement. Summary of the Invention [Problem to be solved by the invention]

[0004] One object of the present invention is to provide a torque detection device for a power tool that provides an accurate torque value without being directly affected by vibrations of the power body because the torque sensor is installed on the inner shell cover.

[0005] One object of the present invention is to provide a torque detection device for a power tool in which the torque sensor is not fixed directly to the element that transmits power, so that it does not rotate along with the power unit, thereby avoiding problems such as breakage of the electric wires and poor contact, and improving ease of assembly. [Means for solving the problem]

[0006] To achieve the above object, the present invention provides a torque detection device for a power tool, including an outer housing, a power structure, a protective cover, an inner shell cover, a bearing set, and a torque sensor. The power structure is installed in the outer housing and includes a power body, which has a drive shaft. The protective cover is fitted onto the power body. The bearing set includes a front bearing and a rear bearing, the front bearing being installed between the protective cover and the inner shell cover, and the rear bearing being installed between the inner shell cover and the outer housing. At least one torque sensor is installed on the inner shell cover. [Effects of the Invention]

[0007] Compared with the prior art, in the torque detection device for a power tool of the present invention, the torque sensor is installed on the inner shell cover, and the torque of the power unit is transmitted to the torque sensor again via the protective cover and the inner shell cover. Therefore, after the power unit exceeds a predetermined torque, the torque is reversed and transmitted to the protective cover and the inner shell cover, and then to the torque sensor. Since the torque sensor is not directly fixed on the power transmission element, it is not affected by the vibration of the power unit. Therefore, the torque sensor can detect the torque of the power unit and provide an accurate torque value, which improves practicality in terms of use. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic three-dimensional external view of a torque detection device according to the present invention. [Figure 2] 1 is a schematic three-dimensional external view of a torque detection device according to the present invention with an outer housing removed; [Figure 3] 1 is a schematic exploded view of a torque detection device according to the present invention with an outer housing removed; [Figure 4] 1A and 1B are cross-sectional views of a torque detection device according to the present invention, taken from both sides. [Figure 5] 1A and 1B are cross-sectional views of a torque detection device according to the present invention, taken from both sides. [Figure 6]1 is a schematic diagram illustrating an application of a torque detection device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The detailed description and technical contents of the present invention will be described below based on the drawings, but the attached drawings are provided for reference and explanation only, and are not intended to limit the present invention.

[0010] 1 to 3 are a schematic three-dimensional external view of a torque detection device according to the present invention, a schematic three-dimensional external view of the torque detection device with the outer housing removed, and a schematic three-dimensional exploded view of the torque detection device with the outer housing removed, respectively. The present invention relates to a torque detection device 1 for a power tool, which includes an outer housing 10, a power structure 20, a protective cover 30, an inner shell cover 40, a bearing set 50, and at least one torque sensor 60. The power structure 20 is mounted within the outer housing 10, and the power structure 20 includes a power unit 21. The protective cover 30 is fitted onto the power unit 21, and the inner shell cover 40 is fitted onto the protective cover 30. The bearing set 50 is installed between the power unit 21 and the outer housing 10. The torque sensor 60 is installed on the inner shell cover 40. The power tool can measure torque values ​​via the torque sensor 60 and control the operation of the power unit 21 accordingly. A more detailed description of the torque detection device 1 is provided below.

[0011] The outer housing 10 is the outer frame of the power tool. The power structure 20 is installed inside the outer housing 10. The power structure 20 includes a power unit 21, which has a drive shaft 211. In this embodiment, the power unit 21 is an electric motor that uses a battery as a power source to rotate the drive shaft 211. However, in actual implementation, the power unit 21 may be an air motor that uses compressed air as a power source to rotate the drive shaft 211.

[0012] The protective cover 30 is fitted onto the power body 21, and has a protective cover front side 31 adjacent to the drive shaft 211 and an opposing protective cover rear side 32. A plurality of front ratchet pawls 311 are provided on the edge of the protective cover front side 31. A plurality of rear ratchet pawls 321 are provided on the edge of the protective cover rear side 32.

[0013] The inner shell cover 40 fits over the protective cover 30, and has an inner shell front side 41 close to the drive shaft 211 and an inner shell rear side 42 spaced apart from the drive shaft 211. The inner shell cover 40 has a front flange 411 formed on the edge of the inner shell front side 41, and a rear fastening piece 421 formed on the inner shell rear side 42.

[0014] The bearing set 50 includes a front bearing 51 and a rear bearing 52. The front bearing 51 is disposed between the protective cover 30 and the inner shell cover 40. The rear bearing 52 is disposed between the inner shell cover 40 and the outer housing 10. Specifically, the front bearing 51 is located at the front side 31 of the protective cover, and the rear bearing 52 is located at the rear side 42 of the inner shell.

[0015] In one embodiment of the present invention, the power structure 20 further includes a pair of motor fixing pieces 22. The pair of motor fixing pieces 22 includes a front fixing piece 221 and a rear fixing piece 222 disposed on opposite sides of the protective cover 30. A plurality of front convex pieces 2211 are disposed spaced apart on the periphery of the front fixing piece 221. A plurality of rear convex pieces 2221 are disposed spaced apart on the periphery of the rear fixing piece 222.

[0016] Specifically, the front fixed piece 221 is engaged with the front ratchet pawl 311 of the protective cover 30 via the front convex piece 2211, and is positioned at one end of the front side 31 of the protective cover. In addition, the rear fixed piece 222 is engaged with the rear ratchet pawl 321 of the protective cover 30 via the rear convex piece 2221, and is positioned at one end of the rear side 32 of the protective cover.

[0017] In one embodiment of the present invention, the power structure 20 further includes a plurality of front locking members 23 and a plurality of rear locking members 24. The front fixing piece 221 has a plurality of first locking holes 2210 and a plurality of second locking holes 210 corresponding to the power body 21. The front fixing piece 221 is fixed to the power body 21 by penetrating the first locking holes 2210 and the second locking holes 210 via the front locking members 23. The rear fixing piece 222 has a plurality of third locking holes 2220 and a plurality of fourth locking holes 4210 corresponding to the rear fastening piece 421 of the inner shell cover 40. The rear fixing piece 222 is fixed to the inner shell cover 40 by penetrating the fourth locking holes 4210 and the third locking holes 2220 via the rear locking members 24.

[0018] Furthermore, the torque sensor 60 can be installed on the outer peripheral surface of the inner shell cover 40 as a strain gauge. In this embodiment, the torque sensors 60 are installed in pairs. The torque sensors 60 are installed on opposite sides of the inner shell cover 40. In one embodiment of the present invention, a groove 401 is provided on the outer peripheral surface of the inner shell cover 40, and the torque sensor 60 is installed in the groove 401. It should be noted here that the provision of the groove 401 can provide good positioning for the installation of the torque sensor 60.

[0019] 4 and 5, which are combined cross-sectional views of the torque detection device of the present invention from both directions. As shown in FIG. 4, the power structure 20 of the present invention is installed in the outer housing 10. The front bearing 51 is installed between the protective cover 30 and the inner shell cover 40 and is located on the front side 31 of the protective cover. The rear bearing 52 is installed between the inner shell cover 40 and the outer housing 10 and is located on the rear side 42 of the inner shell. The pair of motor fixing pieces 22 are installed on opposite sides of the power body 21. In addition, the front flange 411 of the inner shell cover 40 is fixed to the inner wall surface of the outer housing 10. The rear fastening piece 421 of the inner shell cover 40 abuts against the inner wall surface of the outer housing 10. Since the front side 41 of the inner shell is fixedly attached to the outer housing 10, when the rear side 42 of the inner shell rotates, the front side 41 of the inner shell does not rotate accordingly, and as a result, the inner shell cover 40 is deformed, and the torque sensor 60 installed on the inner shell cover 40 receives a deformation signal.

[0020] Therefore, when a reversing force is generated in the power body 21, the rear fixing piece 222 transmits the reversing force so that the rear fastening piece 421 rotates, and the inner shell cover 40 is rotated and deformed accordingly.

[0021] 5, in this embodiment, the pair of torque sensors 60 are installed on opposite sides of the inner shell cover 40. The torque generated by the power unit 21 is transmitted to each torque sensor 60 via the protective cover 30 and the inner shell cover 40. Specifically, when the power unit 21 operates and receives a resistance force, it generates a reversing force. The reversing force is transmitted to the protective cover 30 and the inner shell cover 40 and further to the torque sensor 60, causing the torque sensor 60 to generate a signal.

[0022] Continuing with reference to FIG. 6, there is shown a schematic diagram of an application of the torque sensing device of the present invention. The torque sensing device 1 of the present invention further includes a transmission 70. The transmission 70 is connected to the drive shaft 211 of the power tool 21 to provide the required rotational output. The power tool also includes a battery and a control board (not shown). The battery and the control board are installed in the outer housing 10, and the control board is electrically connected to the power tool 21 and the torque sensor 60.

[0023] Therefore, after the operation of the power body 21 exceeds a predetermined torque, the control board receives the signal transmitted by the torque sensor 60 and immediately stops the operation of the power body 21.

[0024] It should be noted here that the torque sensor 60 of the present invention is not directly fixed on the element that transmits power, and is therefore not affected by the vibration of the power body 21. Therefore, the torque sensor 60 can detect the torque of the power body 21 and provide an accurate torque value.

[0025] The above description is merely a preferred embodiment of the present invention and does not define the scope of the claims of the present invention. Any other equivalent modifications that utilize the patent concepts of the present invention are also within the scope of the claims of the present invention. [Explanation of symbols]

[0026] 1 Torque detection device 10 outer housing 20 Power structure 21 Power body 210 Second lock hole 211 Drive shaft 22 Motor fixing piece 221 Front fixation piece 2210 First lock hole 2211 Front convex piece 222 Rear fixation piece 2220 3rd lock hole 2221 Posterior convex piece 23 Front locking member 24 Rear locking material 30 Protective Cover 31 Front side of protective cover 311 Front ratchet pawl 32 Rear side of protective cover 321 Rear ratchet pawl 40 Inner shell cover 401 Groove 41 Front of inner shell 411 Front flange 42 Rear of inner shell 421 Rear attachment piece 4210 4th lock hole 50 bearing sets 51 Front bearing 52 Rear bearing 60 Torque sensor 70 Transmission

Claims

1. An outer housing; a power structure installed in the outer housing, the power structure including a power body, the power body having a drive shaft; a protective cover fitted onto the power body; an inner shell cover that fits over the protective cover; a bearing set including a front bearing and a rear bearing, the front bearing being disposed between the protective cover and the inner shell cover, and the rear bearing being disposed between the inner shell cover and the outer housing; and at least one torque sensor mounted on the inner shell cover.

2. 2. The torque detection device for a power tool according to claim 1, wherein the protective cover has a protective cover front side adjacent to the drive shaft, and the front bearing is located on the protective cover front side.

3. 3. The torque detection device for a power tool according to claim 2, wherein the inner shell cover has an inner shell rear side spaced from the drive shaft, and the rear bearing is located on the inner shell rear side.

4. 4. The torque detector for a power tool according to claim 3, wherein a plurality of front ratchet pawls are provided on a front edge of the protective cover, and a plurality of rear ratchet pawls are provided on a rear edge of the protective cover.

5. 5. The torque detection device for a power tool according to claim 4, wherein the power structure further includes a pair of motor fixing pieces, the pair of motor fixing pieces including a front fixing piece and a rear fixing piece installed on opposite sides of the protective cover, a plurality of front convex pieces installed spaced apart on the periphery of the front fixing piece, a plurality of rear convex pieces installed spaced apart on the periphery of the rear fixing piece, the front fixing piece engaging with the plurality of front ratchet pawls via the plurality of front convex pieces to be positioned at one end of the front side of the protective cover, and the rear fixing piece engaging with the plurality of rear ratchet pawls via the plurality of rear convex pieces to be positioned at one end of the rear side of the protective cover.

6. 6. The torque detection device for a power tool according to claim 5, wherein the power structure further includes a plurality of front locking members, the front fixed piece has a plurality of first locking holes formed therein, and a plurality of second locking holes formed therein corresponding to the power body, and the front fixed piece is inserted through the plurality of first locking holes and the plurality of second locking holes via the plurality of front locking members to be fixed on the power body.

7. 4. The torque detection device for a power tool according to claim 3, wherein the inner shell cover has an inner shell front side adjacent to the drive shaft, and the inner shell cover is fixed to the inner wall surface of the outer housing at an edge of the inner shell front side.

8. The torque detection device for a power tool as described in claim 5, wherein the inner shell cover has a rear fastening piece formed on the rear side of the inner shell, and the protective cover is fixed to the rear fastening piece via the rear fixing piece, thereby causing the inner shell cover to rotate in a linked manner.

9. 9. The torque detection device for a power tool according to claim 8, wherein the power structure further includes a plurality of rear locking members, the rear fixing piece has a plurality of third locking holes formed therein, and a plurality of fourth locking holes formed corresponding to the rear fastening piece, and the rear fixing piece is inserted through the plurality of fourth locking holes and the plurality of third locking holes via the plurality of rear locking members and fixed onto the inner shell cover.

10. The torque detection device for a power tool according to claim 1 , wherein the at least one torque sensor is a pair, and the pair of torque sensors are installed on opposite sides of the inner shell cover.

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