TWI841378B - Torque module for power tools - Google Patents

Abstract

The present invention is a torque-fixing module for a power tool, comprising a transmission ring, two buffer units, an inner shaft and an outer shaft; the transmission ring comprises a main body, a coupling portion, a central shaft, two accommodating chambers and two detent blocks; the two buffer units are respectively arranged in parts of the two accommodating chambers, so that the two accommodating chambers respectively leave an accommodating space; the inner shaft comprises an inner disc body, two inner protrusions extending into the two accommodating spaces, an axial groove for the central shaft to extend into, a shaft rod, and a clamping portion; the outer shaft comprises an outer disc body, two outer protrusions, a shaft tube, a detent portion, an axial hole, and a clamping groove for the clamping portion of the inner shaft to extend into. Thereby, the fixed torque module can provide different torque outputs in forward and reverse rotation, and has high rotation speed, good working efficiency, and can reduce manufacturing costs.

Description

Torque module for power tools

The present invention relates to a power tool, and in particular to a torque-fixing module for a power tool.

Power tools include pneumatic tools, electric tools or hydraulic driven tools, etc. These power tools are usually connected to a tool head through a rotating shaft to rotate parts such as bolts or nuts. When the rotating shaft is reversed to loosen the nut or bolt, the power tool needs to provide as much torque as possible to smoothly unscrew the nut or bolt. However, when the user tightens the nut or bolt, it is necessary to control the torque of the rotating shaft in the proper range to avoid damaging the bolt or nut by tightening it too tightly, or making it difficult to disassemble in the future. In addition, in many applications such as installing tire frames, the torque of multiple nuts must be consistent, otherwise uneven stress may cause some nuts to loosen easily after long-term vibration.

Currently, there are pneumatic tools that use the principle of oil pressure or planetary gear reduction mechanism to control the torque of the output shaft. However, the high precision of the structure processing leads to high cost, and the low speed leads to poor working efficiency. Therefore, how to control the size of the output torque at high speed and make the processing easy to reduce the manufacturing cost has become a technical problem that needs to be solved urgently in the industry.

One object of the present invention is to provide a torque-fixing module for a power tool, which can provide different torque outputs in forward and reverse rotation. Another object of the present invention is to provide a torque-fixing module for a power tool, which has high rotation speed, good working efficiency, and can reduce manufacturing costs.

In order to achieve the above-mentioned purpose, the torque-fixing module of the present invention is used for a power tool, which has an output part. The torque-fixing module includes a transmission ring, two buffer units, an inner shaft and an outer shaft; the transmission ring includes a main body, a coupling part extending from the main body and used to couple with the output part, a spindle extending from one side of the main body opposite to the coupling part, two chambers are arranged in the main body and are respectively located on two sides of the spindle, and two detent blocks extending from the body and being farther from the spindle than the two chambers; the two buffer units are respectively arranged in parts of the two chambers, so that the two chambers respectively leave a receiving space; the inner shaft comprises an inner disc body, two inner protrusions extending from the inner disc body and extending into the two receiving spaces, an axial groove arranged in the inner disc body and for the spindle of the transmission ring to extend into, a shaft extending from one side of the inner disc body opposite to the two inner protrusions, and a The clamping part is located at one end of the shaft rod; the outer shaft member includes an outer disc body, two outer protrusions extending from the outer disc body toward the main body of the transmission ring and located on the outer side of the inner disc body, a shaft tube extending from the outer disc body opposite to one side of the two outer protrusions, a detent part is located at one end of the shaft tube, an axle hole extending from the outer disc body to the inside of the shaft tube and for the shaft rod of the inner shaft member to extend into, and a clamping groove located at an inner end of the axle hole and for the inner shaft member to be The clamping portion extends into the inner disk body; wherein the inner disk body is located between the outer disk body and the main body of the transmission ring. When the transmission ring rotates in a first direction, the two detent blocks hit the two outer protrusions to transmit the rotational force to the outer shaft. When the transmission ring rotates in a second direction opposite to the first direction, the two buffer units hit the two inner protrusions to transmit the rotational force to the inner shaft, and then transmit the rotational force to the outer shaft through the clamping portion and the clamping groove.

Thereby, the fixed torque module can provide different torque outputs in forward rotation (second direction) and reverse rotation (first direction), and has high rotation speed, good working efficiency, and can reduce manufacturing costs.

The following three preferred embodiments are used in conjunction with drawings to explain in detail the technical content and features of the present invention. As shown in Figures 1 to 4, a torque module 1 for a power tool provided by the first preferred embodiment of the present invention is provided. The torque module 1 is built-in on a power tool 2. The power source of the power tool 2 is not limited, for example, it can be electric, pneumatic or hydraulically driven. This embodiment takes a pneumatic tool as an example.

The power tool 2 is driven by a pneumatic motor 3 and an impact group, and the rotational power of the pneumatic motor 3 is transmitted forward through the impact group. For the convenience of explanation, the front of this article is the direction of arrow F in Figure 2, and the rear is the direction of arrow B. The impact group is the output part 4 of the power tool 2, which is used to output the rotational power of the pneumatic motor 3. The structure of the power tool, its pneumatic motor and the impact group is not a feature of this case, so it will not be described in detail here. In other embodiments, the impact group may not be provided, and the output shaft 5 of the pneumatic motor 3 or other components are used as the output part 4.

The torque-fixing module 1 includes a transmission ring 10, two buffer units 20, an inner shaft 30 and an outer shaft 40.

The transmission ring 10 is made of metal and includes a body 11 in the shape of a short cylinder, a coupling portion 12 extending rearward from the body 11 and used to couple with the output portion 4, a spindle 14 extending forward from a side of the body 11 opposite to the coupling portion 12, two chambers 16 provided in the body 11 and located at two sides of the spindle 14, and two brake blocks 18 extending forward from the body 11 and farther from the spindle 14 than the two chambers 16. The coupling part 12 has a shaft 121 and two impact blocks 122 extending from the shaft 121 to receive the intermittent knocking force of the impact group. The structure of the coupling part 12 can be changed in conjunction with the output part 4, as long as the outer peripheral cross-section of the shaft 121 is non-circular and can receive the rotational power of the output part 4. The spindle 14 is located at the rotation center of the body 11. The two chambers 16 have the same shape and are symmetrical to the spindle 14. The detent block 18 is roughly located at the outer periphery of the two chambers 16, symmetrical to the spindle 14 and in an arc strip shape, but the shapes of the chambers 16 and the detent block 18 can be changed as needed.

The two buffer units 20 are respectively arranged in the parts of the two chambers 16, so that the two chambers 16 respectively leave a receiving space 17; wherein each of the buffer units 20 comprises an arc-shaped elastic body 22, two arc-shaped elastic sheets 24 and a pad 26, wherein the elastic body 22 is made of natural or artificial polymer materials, such as rubber or silicone, which can be elastically deformed and has the effect of buffering and shock absorption, and the two elastic sheets 24 are made of metal material, arranged in parallel and abutting against the elastic body A convex side 221 of the elastic body 22 is formed, and a gap 161 is left between a concave side 222 of the elastic body 22 and the inner wall of the chamber 16, as shown in FIG. 7b, so that the elastic body 22 can be deformed to a greater extent to provide more buffering space, and the two elastic sheets 24 can also provide a better buffering effect because they are supported by the elastic body 22. The pad 26 is made of metal material and has a considerable thickness, and has better impact resistance to protect the elastic sheets 24 from being damaged by continuous impact.

The inner shaft 30 includes a circular inner disc body 31, two inner protrusions 32 extending backward from the inner disc body 31 and extending into the two accommodating spaces 17, an axial groove 34 arranged at the rear side of the inner disc body 31 and for the central shaft 14 of the transmission ring 10 to extend into, a shaft rod 35 extending forward from one side of the inner disc body 31 opposite to the two inner protrusions 32, and a clamping portion 38 located at one end 36 of the shaft rod 35. The two inner protrusions 32 are in an arc-shaped strip shape and are adjacent to the two pads 26, so that the pads 26 are located between the spring sheet 24 and the inner protrusions 32. However, in other embodiments, if the two spring sheets 24 are thicker, the pads 26 can be omitted, that is, the two spring sheets 24 are located between the inner protrusions 32 and the elastic body 22, and the elastic body 22 and the spring sheet 24 are both in an arc shape convex toward the inner protrusions 32. The shaft groove 34 is for the central shaft 14 to extend into, which can ensure that the inner shaft 30 and the transmission ring 10 maintain concentric rotation. The two ends of the shaft rod 35 are enlarged compared to the middle section 37, so that the thinner middle section 37 can be subjected to force and twisted and deformed to absorb part of the rotational torque, while maintaining sufficient structural strength to avoid breaking due to the inability to withstand the rotational force. The clamping portion 38 has two chamfered surfaces 39, but as long as its outer peripheral cross-section is non-circular, the rotational force can be transmitted to the outer shaft 40, as described below.

The outer shaft 40 includes a circular outer disc body 41, two outer protrusions 42 extending from the outer disc body 41 toward the body 11 of the transmission ring 10 (i.e., backward) and located on the outer side of the inner disc body 31, a shaft tube 44 extending forward from one side of the outer disc body 41 opposite to the two outer protrusions 42, a detent portion 46 disposed at one end 45 of the shaft tube 44, an axial hole 47 extending from the outer disc body 41 to the inside of the shaft tube 44 and for the shaft rod 35 of the inner shaft 30 to extend therein, and a clamping groove 49 located at an inner end 48 of the axial hole 47 and for the clamping portion 38 of the inner shaft 30 to extend therein, as shown in FIG. 5 . Among them, the two outer protrusions 42 are in the shape of arc strips and are located on the outer side of the inner disk body 31 in an alternating manner with the two detent blocks 18. The shaft tube 44 is sleeved on the outside of the shaft rod 35 of the inner shaft 30 through the shaft hole 47. The detent portion 46 is in the shape of a square column, but it can also be changed to other shapes, such as its outer peripheral cross-section is non-circular, or it is tubular and its inner peripheral cross-section is non-circular, both of which can transmit rotational power. In actual use, the user can connect a suitable tool head (not shown) such as a socket wrench to the detent portion 46 to drive the nut or bolt. As shown in FIG. 5 , the inner peripheral shape of the engaging groove 49 complements the engaging portion 38 and also has two chamfered surfaces 491 so that the outer shaft 40 can be driven by the inner shaft 30 . In other embodiments, the inner peripheral cross-section of the engaging groove 49 is non-circular so as to receive the rotational force from the inner shaft 30 .

As shown in FIGS. 2 and 6 , the inner disc 31 is located between the outer disc 41 and the body 11 of the transmission ring 10. When the user wants to loosen the nut and rotate the output portion 4 of the power tool 2 counterclockwise (reverse rotation), the counterclockwise here is based on the perspective of the user of the power tool 2. As shown in FIG. 7 a, the transmission ring 10 is driven by the output portion 4 to rotate in a first direction D1 (i.e., counterclockwise direction). At this time, the two detent blocks 18 hit the two outer protrusions 42 and the rotational force is transferred from the transmission ring 10 to the transmission ring 10. 10 is transmitted to the outer shaft 40. Since the two detent blocks 18 and the two outer protrusions 42 are farther away from the central shaft 14, that is, the lever arm is longer, the torque is larger, and a larger rotational torque can be generated; as shown in FIG. 7b, at this time, there is still a gap between the inner wall of the chamber 16 of the transmission ring 10 and the two inner protrusions 32, so the rotational force of the transmission ring 10 is not transmitted to the inner shaft 30.

On the contrary, when the user wants to tighten the nut and make the output portion 4 of the power tool 2 rotate clockwise (forward), as shown in FIG. 8a, when the transmission ring 10 rotates in a second direction D2 (i.e., clockwise) opposite to the first direction D1, the two detent blocks 18 move away from the two outer protrusions 42 and do not transmit the rotational force from the transmission ring 10 to the outer shaft. As shown in FIG8b, the two buffer units 20 will use the two pads 26 to hit the two inner protrusions 32 to transmit the rotational force of the transmission ring 10 to the inner shaft 30, and then transmit the rotational force to the outer shaft 40 through the clamping portion 38 and the clamping groove 49. Since the two inner protrusions 32 are closer to the spindle 14, the force arm is shorter, so that the torque The clamping portion 38 and the clamping groove 49 are both close to the axis of the central shaft 14, so that the transmitted rotational torque is further reduced. In addition, the elastic body 22 and the spring sheet 24 in the buffer unit 20 can absorb the rotational force of the transmission ring 10. Moreover, the slender structure of the shaft 35 of the inner shaft 30 can absorb the torque due to torsional deformation. These structural designs reduce the final output forward torque. After actual testing, it can be reduced to about one-fourth of the reverse torque. For example, when the reverse torque output is 400 Newton*m, the forward torque output is about 100 Newton*m. The forward torque value can be adjusted according to customer needs to achieve the purpose of fixed torque output.

By means of the above-mentioned design, the torque-fixing module 1 for a power tool provided by the present invention can provide different torque outputs in forward and reverse rotation, and because the outer shaft 40 rotates synchronously with the output portion 4 of the power tool 2, the output speed will not be reduced, and the speed can be as high as 8000 to 9000 rpm regardless of forward or reverse rotation, with excellent working efficiency, and the parts processing accuracy requirement is not as high as that of the conventional hydraulic mechanism, and the processing is easier, so that the manufacturing cost can be greatly reduced, and the market potential is extremely high.

Based on the design spirit of the present invention, the structure of the torque module can have other changes. As shown in FIG. 9, the torque module 1a provided by the second preferred embodiment of the present invention has a structure that is substantially the same as that of the first embodiment. The only difference is that the coupling portion 12a of the transmission ring 10a is a hexagonal shaft 121a for matching the output portion of different power tools. As shown in FIG. 10, the torque module 1a provided by the second preferred embodiment of the present invention has a structure that is substantially the same as that of the first embodiment. The structure of the torque-fixing module 1b provided in the third preferred embodiment is substantially the same as that of the first embodiment, and the difference is that the coupling portion 12b of the transmission ring 10b is provided with a hexagonal embedding hole 13b for matching the output portion of different power tools, so that the torque-fixing module 1b can be externally mounted on the square columnar output shaft of commercially available power tools, which can make the application of the present invention more extensive. In fact, the coupling portion of the transmission ring can be a shaft column whose outer peripheral cross section is non-circular, or a embedding hole whose inner peripheral cross section is non-circular, and the buffer unit can be replaced with other structures that can provide force absorption, such as a spring. All such easily conceivable structural changes should be covered by the scope of the patent application of the present invention.

1, 1a, 1b: torque module 2: power tool 3: pneumatic motor 4: output part 5: output shaft F: front B: rear 10, 10a, 10b: transmission ring 11: body 12, 12a, 12b: coupling part 121, 121a: shaft 122: impact block 13b: embedded hole 14: spindle 16: chamber 161: gap 17: storage space 18: brake block D1: first direction D2: second direction 20: buffer unit 22: elastic body 221: convex side 222: concave side 24: spring 26: pad 30: Inner shaft 31: Inner disc 32: Inner protrusion 34: Shaft groove 35: Shaft rod 36: End 37: Middle section 38: Snap-on part 39: Cutting surface 40: Outer shaft 41: Outer disc 42: Outer protrusion 44: Shaft tube 45: End 46: Detent part 47: Shaft hole 48: Inner end 49: Snap-on groove 491: Cutting surface

Figure 1 is a three-dimensional diagram of a power tool with a fixed torque module according to the first preferred embodiment of the present invention; Figure 2 is a cross-sectional view of Figure 1 along the 2-2 direction; Figures 3-4 are exploded views of the fixed torque module used for a power tool according to the first preferred embodiment of the present invention; Figure 5 is a side view of the outer shaft of the fixed torque module according to the first preferred embodiment of the present invention; Figure 6 is a three-dimensional diagram of the fixed torque module used for a power tool according to the first preferred embodiment of the present invention; Figures 7a-b are schematic diagrams of the fixed torque module of the first preferred embodiment of the present invention in the reverse state; Figures 8a-b are schematic diagrams of the fixed torque module of the first preferred embodiment of the present invention in the forward state; Figure 9 is a three-dimensional diagram of the fixed torque module used for a power tool according to the second preferred embodiment of the present invention; Figure 10 is a three-dimensional diagram of the torque-fixing module used for power tools in the third preferred embodiment of the present invention.

1: Fixed torque module

2: Power tools

4: Output section

10: Transmission ring

11: Body

12: Coupling part

121: Axle

122: Impact block

14: Axis

16: Room

18: brake block

20: Buffer unit

22: Elastic body

24: Shrapnel

26: Pad

30: Inner shaft

31: Inner plate

32: Inner convex block

35: Shaft

36: The end

37: Middle section

38: Snap-on part

39: plane cutting

40:External shaft

41: Outer disk

42: External protrusion

44: Axle tube

45: End

46: Braking part

Claims (9)

A torque-fixing module for a power tool, the power tool having an output portion, the torque-fixing module comprising: a transmission ring, comprising a body, a coupling portion extending from the body and used to couple with the output portion, a spindle extending from the body opposite to one side of the coupling portion, two chambers disposed in the body and respectively located on two sides of the spindle, and two detent blocks extending from the body and farther from the spindle than the two chambers; two buffer units, respectively disposed in parts of the two chambers, so that the two chambers respectively leave a storage space; An inner shaft, comprising an inner disc body, two inner protrusions extending from the inner disc body and extending into the two accommodating spaces, an axial groove provided in the inner disc body and for the central shaft of the transmission ring to extend into, a shaft extending from one side of the inner disc body opposite to the two inner protrusions, and a clamping portion at one end of the shaft; and An outer shaft, comprising an outer disc body, two outer protrusions extending from the outer disc body toward the body of the transmission ring and located on the outer side of the inner disc body, a shaft tube extending from a side of the outer disc body opposite to the two outer protrusions, a detent portion disposed at one end of the shaft tube, an axle hole extending from the outer disc body to the inside of the shaft tube for the shaft rod of the inner shaft to extend into, and a clamping groove located at an inner end of the axle hole for the clamping portion of the inner shaft to extend into; The inner disc body is located between the outer disc body and the body of the transmission ring. When the transmission ring rotates in a first direction, the two detent blocks hit the two outer protrusions to transmit the rotational force to the outer shaft. When the transmission ring rotates in a second direction opposite to the first direction, the two buffer units hit the two inner protrusions to transmit the rotational force to the inner shaft, and then transmit the rotational force to the outer shaft through the clamping portion and the clamping groove. As described in claim 1, the torque-fixing module for a power tool, wherein the buffer unit includes an elastic body and at least one elastic sheet located between the inner protrusion and the elastic body. A torque-fixing module for a power tool as described in claim 2, wherein the elastic body is made of a natural or artificial polymer material. As described in claim 2, the torque-fixing module for a power tool, wherein the buffer unit further includes a pad located between the spring and the inner protrusion. As described in claim 2, the torque-fixing module for a power tool, wherein the elastic body and the spring sheet are both in an arc shape convex toward the inner protrusion. A torque-fixing module for a power tool as described in claim 1, wherein the coupling portion of the transmission ring is a shaft whose outer peripheral cross-section is non-circular, or an embedding hole whose inner peripheral cross-section is non-circular. A torque-fixing module for a power tool as described in claim 1, wherein the two ends of the shaft are enlarged compared to the middle section. As described in claim 1, the torque-fixing module for a power tool, wherein the outer peripheral cross-section of the clamping portion of the inner shaft is non-circular, and the inner peripheral cross-section of the clamping groove of the outer shaft is non-circular. A torque-fixing module for a power tool as described in claim 1, wherein the outer peripheral cross-section of the detent portion is non-circular or the inner peripheral cross-section is non-circular.

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