Torque sensing device for power tool

Abstract

The present application is a torque sensing device for a power tool, which includes an outer housing, a power structure, a sheath, an inner housing, a bearing set and a torque sensor. The power structure is disposed in the outer housing, and the power structure includes a power body and has a driving shaft. The sheath is sleeved on the power body. The bearing set includes a front bearing disposed between the sheath and the inner housing, and a rear bearing disposed between the inner housing and the outer housing. The torque sensor is disposed on the inner housing, so as to provide an accurate torque value.

Description

Technical Field

[0001] This invention relates to power tools, and more particularly to a torque sensing device for a power tool. Background Technology

[0002] Currently, power tools equipped with torque sensors can detect torque and transmit a signal when a predetermined torque is reached to control the power unit to stop operating. However, torque sensors in general power tools are usually located on the transmission mechanism. Therefore, the torque sensor rotates for extended periods as the transmission mechanism operates, leading to problems such as broken wires and poor contact, affecting the electrical connection and causing damage to the power tool. Furthermore, during operation, the transmission mechanism connecting the tool head may vibrate or deform, affecting the torque value detected by the torque sensor and reducing its accuracy. Summary of the Invention

[0003] The main objective of this invention is to provide a torque sensing device for a power tool, wherein the torque sensor is mounted on the inner casing so as not to be directly affected by the vibration of the power body, thereby providing an accurate torque value.

[0004] Another objective of this invention is to provide a torque sensing device for power tools, wherein the torque sensor is not directly fixed to the power transmission component and does not rotate with the power device, thus avoiding problems such as wire breakage and poor contact, and increasing the convenience of assembly.

[0005] To at least achieve the aforementioned main objectives, the present invention provides a torque sensing device for a power tool, comprising a housing, a power structure, a sheath, an inner housing, a bearing assembly, and a torque sensor. The power structure is disposed within the housing and includes a power body having a drive shaft. The sheath is fitted onto the power body. The bearing assembly includes a front bearing and a rear bearing; the front bearing is disposed between the sheath and the inner housing, and the rear bearing is disposed between the inner housing and the housing. At least one torque sensor is disposed on the inner housing.

[0006] Optionally, the sheath has a front side adjacent to the drive shaft, and the front bearing is located on the front side of the sheath.

[0007] Optionally, the inner housing has a rear side away from the drive shaft, and the rear bearing is located on the rear side of the inner housing.

[0008] Optionally, the front edge of the sheath is provided with a plurality of front pawls, and the rear edge of the sheath is provided with a plurality of rear pawls.

[0009] Optionally, the power structure further includes a pair of motor fixing plates, the pair of motor fixing plates including a front fixing plate and a rear fixing plate disposed on opposite sides of the sheath, the periphery of the front fixing plate being provided with a plurality of forward protrusions spaced apart, the periphery of the rear fixing plate being provided with a plurality of rear protrusions spaced apart, the front fixing plate being positioned at one end of the front side of the sheath by each of the forward protrusions engaging with each of the forward pawls, and the rear fixing plate being positioned at one end of the rear side of the sheath by each of the rear protrusions engaging with each of the rear pawls.

[0010] Optionally, the power structure further includes a plurality of front locking fasteners, the front fixing plate being provided with a plurality of first locking holes, and the power body being provided with a plurality of second locking holes. The front fixing plate is fixed to the power body by each of the front locking fasteners passing through each of the first locking holes and each of the second locking holes.

[0011] Optionally, the inner housing has a front side close to the drive shaft, and the end edge of the inner housing on the front side is fixed to the inner wall surface of the outer housing.

[0012] Optionally, the inner shell is fitted with a rear baffle formed on the rear side of the inner shell, and the sheath is fixed to the rear baffle by the rear fixing piece, thereby causing the inner shell to rotate in conjunction.

[0013] Optionally, the power structure further includes a plurality of rear locking fasteners, the rear fixing plate being provided with a plurality of third locking holes, the rear baffle being provided with a plurality of fourth locking holes, and the rear fixing plate being fixed to the inner shell by the rear locking fasteners passing through the fourth locking holes and the third locking holes.

[0014] Optionally, the number of torque sensors is one pair, which are arranged on opposite sides of the inner housing.

[0015] Compared to existing technologies, the torque sensing device of the power tool of the present invention places the torque sensor in the inner shell, and the torque of the power body is transmitted to the torque sensor through the protective sleeve and the inner shell. When the power body exceeds a predetermined torque, it is in a reverse state and transmits the torque to the protective sleeve and the inner shell, and then to the torque sensor. Since the torque sensor is not directly fixed to the power transmission component, it is not affected by the vibration of the power body. Accordingly, the torque sensor can sense the torque of the power body, thereby providing an accurate torque value and increasing its practicality in use. Attached Figure Description

[0016] Figure 1 This is a three-dimensional external view of the torque sensing device of the present invention.

[0017] Figure 2 This is a three-dimensional view of the torque sensing device of the present invention with the outer casing removed.

[0018] Figure 3This is a three-dimensional exploded view of the torque sensing device of the present invention with the outer casing removed.

[0019] Figure 4 and Figure 5 This is a combined cross-sectional view of the torque sensing device of the present invention from both sides.

[0020] Figure 6 This is a schematic diagram illustrating the application of the torque sensing device of the present invention.

[0021] In the picture: 1: Torque sensing device; 10: Housing; 20: Power structure; 21: Power unit; 210: Second locking hole; 211: Drive shaft; 22: Motor fixing plate; 221: Front fixing plate; 2210: First locking hole; 2211: Front protrusion; 222: Rear fixing plate; 2220: Third locking hole; 2221: Rear protrusion; 23: Front locking fastener; 24: Rear locking fastener; 30: Sheath; 31: Front side of sheath; 311: Front pawl; 32: Rear side of sheath; 321: Rear pawl; 40: Inner housing sleeve; 401: Groove; 41: Front side of inner housing; 411: Front flange; 42: Rear side of inner housing; 421: Rear baffle; 4210: Fourth locking hole; 50: Bearing assembly; 51: 52: Front bearing; 60: Torque sensor; 70: Gearbox. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0023] Please refer to Figures 1 to 3 The figures shown are a perspective view of the torque sensing device of the present invention, a perspective view of the torque sensing device without its outer casing, and an exploded perspective view of the torque sensing device without its outer casing. The present invention is a torque sensing device 1 for a power tool, comprising an outer casing 10, a power structure 20, a sheath 30, an inner casing 40, a bearing assembly 50, and at least one torque sensor 60. The power structure 20 is installed in the outer casing 10 and includes a power body 21. The sheath 30 covers the power body 21, and the inner casing 40 fits onto the sheath 30. The bearing assembly 50 is disposed between the power body 21 and the outer casing 10. The torque sensor 60 is disposed on the inner casing 40. Accordingly, the power tool can measure the torque value through the torque sensor 60 and control the operation of the power body 21 accordingly. A more detailed description of the torque sensing device 1 follows.

[0024] The housing 10 is the housing of a power tool. Furthermore, the power structure 20 is disposed within the housing 10. The power structure 20 includes a power body 21, and the power body 21 has a drive shaft 211. In this embodiment, the power body 21 is an electric motor, which uses a battery as a power source to drive the drive shaft 211 to rotate. However, in actual implementation, the power body 21 can also be configured as a pneumatic motor, which uses compressed air as a power source to drive the drive shaft 211 to rotate.

[0025] The sheath 30 is fitted onto the power body 21, and the sheath 30 has a front side 31 close to the drive shaft 211 and a rear side 32 opposite to it. The end edge of the front side 31 is provided with a plurality of front pawls 311. The end edge of the rear side 32 is provided with a plurality of rear pawls 321.

[0026] Furthermore, the inner housing 40 is fitted over the sheath 30, and the inner housing 40 has a front side 41 close to the drive shaft 211 and a rear side 42 away from the drive shaft 211. The inner housing 40 has a front flange 411 formed at the end edge of the front side 41, and a rear baffle 421 formed on the rear side 42.

[0027] The bearing assembly 50 includes a front bearing 51 and a rear bearing 52. The front bearing 51 is disposed between the sheath 30 and the inner housing 40. The rear bearing 52 is disposed between the inner housing 40 and the outer housing 10. Specifically, the front bearing 51 is located on the front side 31 of the sheath; and the rear bearing 52 is located on the rear side 42 of the inner housing.

[0028] In one embodiment of the present invention, the power structure 20 further includes a pair of motor fixing plates 22. The pair of motor fixing plates 22 includes a front fixing plate 221 and a rear fixing plate 222 disposed on opposite sides of the sheath 30. A plurality of front protrusions 2211 are spaced apart on the periphery of the front fixing plate 221. A plurality of rear protrusions 2221 are spaced apart on the periphery of the rear fixing plate 222.

[0029] Specifically, the front fixing piece 221 is positioned at one end of the front side 31 of the sheath 30 by engaging with each of the front protrusions 2211 and the front pawls 311 of the sheath 30. Similarly, the rear fixing piece 222 is positioned at one end of the rear side 32 of the sheath 30 by engaging with each of the rear protrusions 2221 and the rear pawls 321 of the sheath 30.

[0030] In one embodiment of the present invention, the power structure 20 further includes a plurality of front locking fasteners 23 and a plurality of rear locking fasteners 24. The front fixing piece 221 is provided with a plurality of first locking holes 2210, and the power body 21 is correspondingly provided with a plurality of second locking holes 210. The front fixing piece 221 is fixed to the power body 21 by each of the front locking fasteners 23 passing through each of the first locking holes 2210 and each of the second locking holes 210. Furthermore, the rear fixing piece 222 is provided with a plurality of third locking holes 2220, and the rear baffle 421 of the inner shell 40 is correspondingly provided with a plurality of fourth locking holes 4210. The rear fixing piece 222 is fixed to the inner shell 40 by each of the rear locking fasteners 24 passing through each of the fourth locking holes 4210 and each of the third locking holes 2220.

[0031] Furthermore, the torque sensor 60 can be configured as a strain gauge, which is disposed on the outer edge surface of the inner housing 40. In this embodiment, the number of torque sensors 60 is set to a pair. The pair of torque sensors 60 are disposed on opposite sides of the inner housing 40. In one embodiment of the present invention, a groove 401 is provided on the outer edge surface of the inner housing 40, and the torque sensor 60 is disposed in the groove 401. It should be noted that the groove 401 provides better positioning for the torque sensor 60.

[0032] Please refer to again Figure 4 and Figure 5 This is a combined cross-sectional view of the torque sensing device of the present invention from both sides. Figure 4 As shown, the power structure 20 of the present invention is disposed in the outer casing 10. The front bearing 51 is disposed between the sheath 30 and the inner casing 40, and is located on the front side 31 of the sheath. The rear bearing 52 is disposed between the inner casing 40 and the outer casing 10, and is located on the rear side 42 of the inner casing. Furthermore, the pair of motor fixing plates 22 are disposed on opposite sides of the power body 21. In addition, the front flange 411 of the inner casing 40 is fixed to the inner wall surface of the outer casing 10. The rear baffle 421 of the inner casing 40 abuts against the inner wall surface of the outer casing 10. Since the front side 41 of the inner casing is fixed to the outer casing 10, when the rear side 42 of the inner casing rotates, it will not cause the front side 41 of the inner casing to rotate together. As a result, the inner casing 40 deforms, thereby causing the torque sensor 60 disposed on the inner casing 40 to receive a deformation signal.

[0033] Accordingly, when the power body 21 generates a reversing force, the reversing force is transmitted to the rear baffle 421 for rotation via the rear fixing plate 222, thereby causing the inner shell sleeve 40 to rotate and deform.

[0034] Please refer to Figure 5As shown, in this embodiment, the pair of torque sensors 60 are disposed on opposite sides of the inner housing 40. Furthermore, the torque generated by the power unit 21 is transmitted to each torque sensor 60 through the sheath 30 and the inner housing 40. Specifically, when the power unit 21 encounters resistance during operation, a reversing force is generated. This reversing force is transmitted to the sheath 30 and the inner housing 40, and then to the torque sensor 60, causing the torque sensor 60 to generate a signal.

[0035] Please continue reading. Figure 6 This is a schematic diagram illustrating the application of the torque sensing device of the present invention. The torque sensing device 1 of the present invention also includes a gearbox 70. The gearbox 70 is connected to the drive shaft 211 of the power unit 21 to provide the required rotational output. Furthermore, the power tool also includes a battery and a control board (not shown). The battery and the control board are disposed in the housing 10, and the control board is electrically connected to the power unit 21 and the torque sensor 60.

[0036] Accordingly, when the power unit 21 operates beyond the predetermined torque, the control board receives the signal transmitted by the torque sensor 60 and immediately stops the operation of the power unit 21.

[0037] It should be noted that the torque sensor 60 of the present invention is not directly fixed to the power transmission component, and therefore is not affected by the vibration of the power body 21. Accordingly, the torque sensor 60 can sense the torque of the power body 21, thereby providing an accurate torque value.

[0038] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A torque sensing device for a power tool, characterized in that, include: An outer shell; A power structure is disposed in the housing, the power structure includes a power body, the power body is an electric motor or a pneumatic motor, and the power body has a drive shaft. A protective sleeve is fitted onto the power unit; An inner shell is fitted over the outer sheath; A bearing assembly comprising a front bearing and a rear bearing, the front bearing being disposed between the sheath and the inner housing, and the rear bearing being disposed between the inner housing and the outer housing; and At least one torque sensor, which is a strain gauge, is mounted on the inner housing and located within the outer housing.

2. The torque sensing device for a power tool as described in claim 1, characterized in that, The sheath has a front side close to the drive shaft, and the front bearing is located on the front side of the sheath.

3. The torque sensing device for a power tool as described in claim 2, characterized in that, The inner housing has a rear side away from the drive shaft, and the rear bearing is located on the rear side of the inner housing.

4. The torque sensing device for a power tool as described in claim 3, characterized in that, The front edge of the sheath is provided with a plurality of front pawls, and the rear edge of the sheath is provided with a plurality of rear pawls.

5. The torque sensing device for a power tool as described in claim 4, characterized in that, The power structure also includes a pair of motor fixing plates, which include a front fixing plate and a rear fixing plate disposed on opposite sides of the sheath. The periphery of the front fixing plate is provided with a plurality of forward protrusions at intervals, and the periphery of the rear fixing plate is provided with a plurality of rear protrusions at intervals. The front fixing plate is positioned at one end of the front side of the sheath by interlocking with each of the forward protrusions and each of the forward pawls, and the rear fixing plate is positioned at one end of the rear side of the sheath by interlocking with each of the rear protrusions and each of the rear pawls.

6. The torque sensing device for a power tool as described in claim 5, characterized in that, The power structure also includes a plurality of front locking fasteners. The front fixing plate is provided with a plurality of first locking holes, and the power body is provided with a plurality of second locking holes. The front fixing plate is fixed to the power body by the front locking fasteners passing through the first locking holes and the second locking holes.

7. The torque sensing device for a power tool as described in claim 3, characterized in that, The inner housing has a front side close to the drive shaft, and the end edge of the inner housing on the front side is fixed to the inner wall surface of the outer housing.

8. The torque sensing device for a power tool as described in claim 5, characterized in that, The inner shell is fitted with a rear baffle formed on the rear side of the inner shell. The sheath is fixed to the rear baffle by the rear fixing piece, thereby causing the inner shell to rotate in conjunction.

9. The torque sensing device for a power tool as described in claim 8, characterized in that, The power structure also includes a plurality of rear locking fasteners, the rear fixing plate is provided with a plurality of third locking holes, and the rear baffle is provided with a plurality of fourth locking holes. The rear fixing plate is fixed to the inner shell by the rear locking fasteners passing through the fourth locking holes and the third locking holes.

10. The torque sensing device for a power tool as described in claim 1, characterized in that, There is a pair of torque sensors, which are located on opposite sides of the inner housing.

Images