An SMA-driven multi-degree-of-freedom intelligent electric wrench

Abstract

The present invention discloses an SMA-driven multi-degree-of-freedom intelligent electric wrench, which relates to the technical field of fastening and disassembly tools. The electric wrench is provided with a variable-caliber unit D including a folding assembly, an SMA spring, a heat-conducting strip, a mounting rod, and a heat sink. The mounting rod is sleeved outside the transmission shaft, and its front end is fixed to the handle. The heat sink is fixed to the mounting rod along the circumference of the mounting rod. The folding assembly is connected to the rear end of the transmission shaft via a central axis. The motor drives the folding assembly to rotate around the axis of the central axis. The SMA spring is electrically connected to the power supply and is connected to the heat sink via the heat-conducting strip for heat exchange. The folding assembly of the present invention can be folded or stretched under the action of the SMA spring, and always maintains at least three angles stretched. It can realize the fastening and disassembly of hexagonal screw parts of different calibers without replacing the assembly, greatly improving the portability and working efficiency of the hexagonal wrench. The structure is simple, light, efficient and environmentally friendly, and it is also conducive to controlling its manufacturing cost.

Description

Technical Field

[0001] The invention relates to the technical field of fastening and disassembling tools, and in particular to a wrench used for fastening or disassembling threaded parts of different specifications. Background Art

[0002] An Allen wrench is a tool used to tighten and remove hexagonal threaded parts. To accommodate the various specifications of hexagonal threaded parts, Allen wrenches usually need to be provided in sets, which makes storage and carrying inconvenient. At the same time, when using a set of Allen wrenches to tighten or remove hexagonal threaded parts, you first need to confirm the specifications of the hexagonal threaded parts, and then use the Allen wrench corresponding to the model to tighten or remove them. This process is relatively cumbersome and the work efficiency is not ideal. In addition, existing Allen wrenches are not well suited for working environments such as confined spaces. They have difficulty applying force and are inconvenient to operate, making disassembly difficult or even impossible.

[0003] Prior art 1: a wrench

[0004] Application number: 201510223782.X, application date: 2015.05.05, publication (announcement) date: 2016.12.07.

[0005] Prior art 1 discloses a wrench for turning a workpiece, which includes a one-way transmission mechanism. The one-way transmission mechanism includes a roller, a first component, and a second component at least partially sleeved in the first component; the first component is fixedly arranged on the turning part of the wrench, and the second component is used to cooperate with the workpiece. The direction of the torque from the turning part is a first direction and a second direction along the rotation axis of the first component; for one of the torque in the first direction and the torque in the second direction, the second component is stationary relative to the first component to output the torque to the workpiece; for the other one, the second component rotates relative to the first component without outputting the torque to the workpiece. The one-way transmission mechanism of the present invention does not require high-speed rotation, so its torque can meet the use requirements of the wrench, so the wrench of the present invention can be comparable to the wrench of the prior art. At the same time, the one-way transmission mechanism remains silent during use and has the characteristics of wear-resistant bearings.

[0006] However, the length of the prior art 1 itself is still fixed, which limits its use in narrower and more complex environments.

[0007] Prior art 2: a wrench

[0008] Application number 202111522102.6, application date 2021.12.13, authorization announcement date 2024.01.26.

[0009] Prior Art 2 discloses a wrench comprising a torque output assembly for tightening a fastener and a retraction angle confirmation assembly rotatably mounted on the torque output assembly and used to determine the retraction angle of the fastener. The retraction angle confirmation assembly has multiple scale lines on its surface, and the torque output assembly has arrows pointing to the scale lines on its surface. The wrench of this invention integrates both angle and torque output modes, enabling the workpiece to be tightened to a specified torque before being retracted to a specified angle, saving time in tool changes and improving efficiency.

[0010] However, the wrenches of the prior art 2 still use fixed calibers. When installing screws of different sizes, it is still necessary to frequently replace wrenches of different calibers, which causes inconvenience in use.

[0011] Through the above search, it is found that the above technical solutions do not affect the novelty of the present invention; and the combination of the above prior arts does not destroy the creativity of the present invention. Summary of the Invention

[0012] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides an SMA-driven multi-degree-of-freedom intelligent electric wrench.

[0013] The present invention adopts the following technical solution to solve the technical problem: an SMA-driven multi-degree-of-freedom intelligent electric wrench, wherein a mounting cavity is provided in the handle, a motor and a power supply are fixedly installed in the mounting cavity, and the output end of the motor is axially coupled to the front end of the transmission shaft;

[0014] The above-mentioned intelligent electric wrench is provided with a variable-caliber unit D including a folding and unfolding component, an SMA spring, a heat-conducting strip, a mounting rod and a heat sink;

[0015] The mounting rod is a hollow tubular structure, which is sleeved outside the transmission shaft with a gap between the mounting rod and the transmission shaft, and the front end of the mounting rod is fixedly mounted on the handle; the radiator is arranged around the circumference of the mounting rod and is fixedly mounted on the mounting rod;

[0016] The folding and unfolding assembly is connected to the rear end of the transmission shaft via a central shaft, and the motor drives the folding and unfolding assembly to rotate around the axis of the central shaft.

[0017] The SMA spring is electrically connected to the power supply and is connected to the heat sink for heat exchange through the heat conductive strip. When the SMA spring is powered on, it heats up and contracts, driving the folding assembly to fold and retract until the folding assembly can be placed in the hexagonal hole of the threaded part. When the power is off, it cools down and expands, driving the folding assembly to expand and open until the folding assembly is engaged with the hexagonal hole.

[0018] Furthermore, the folding and unfolding assembly includes six folding and unfolding units of triangular frame structure;

[0019] The six folding units are arranged and assembled along the circumference of the central axis. The vertices of the folding units close to the central axis are slidably mounted and connected to the connecting column, and are rotatably mounted and connected to the central axis through the connecting column. A rotating pair is formed between the folding unit and the central axis to support the folding unit to swing up or down, and a sliding pair is formed between the folding unit and the connecting column to support the folding unit to slide toward or away from the central axis along the connecting column.

[0020] The adjacent foldable units are hinged at their joint edges with the intersection line as the rotation axis, forming the foldable assembly having a hexagonal pyramid-like structure when fully extended and opened;

[0021] The six folding units are divided into three adjacent pairs, and each pair of the folding units is equipped with an SMA spring. The two ends of the SMA spring are respectively connected to the two vertices of the non-hinged edges of the corresponding pair of folding units. When the SMA spring is powered on, it heats up and contracts, driving the corresponding pair of folding units to fold and close. When the power is off, it cools down and stretches, driving the corresponding pair of folding units to stretch and open.

[0022] Furthermore, a bending unit E is provided between the central shaft and the rear end of the transmission shaft;

[0023] The bending unit E has bending adjustment and shaping functions, and transmits the rotation output by the motor to the folding assembly via the transmission shaft and the central shaft, driving the folding assembly to rotate around the axis of the central shaft.

[0024] Furthermore, the bending unit E includes a first universal joint group, a second universal joint group, a positioning ring and a solid tube;

[0025] The first universal joint assembly and the second universal joint assembly each include a pair of cross-type universal joints sharing a central universal yoke; a first input universal yoke at the input end of the first universal joint assembly is axially coupled to the rear end of the transmission shaft, a first output universal yoke at the output end is axially coupled to a second input universal yoke at the input end of the second universal joint assembly, and a second output universal yoke at the output end of the second universal joint assembly is axially coupled to the central shaft;

[0026] The first input universal yoke, the first output universal yoke, the second input universal yoke and the second output universal yoke are all rotatably sleeved with the positioning ring forming a rotation pair around their own axis;

[0027] The positioning ring is fixed by the solid tube and can adjust its posture following the bending of the solid tube.

[0028] Furthermore, the front end of the solid tube is fixedly installed, and the end is a forked structure, and the forked structure is respectively fixedly connected to each of the positioning rings.

[0029] Furthermore, the front end of the solid tube is fixedly connected to the radiator through the heat conducting strip.

[0030] Furthermore, the solid tube is a gooseneck tube.

[0031] Furthermore, the SMA spring is connected to the heat conducting strip through the solid tube for heat exchange.

[0032] Furthermore, a motor switch for controlling the operation of the motor and a power switch for controlling the operation of the SMA spring are provided at the tail end of the handle.

[0033] Furthermore, the radiator includes copper radiating fins that are evenly and densely distributed.

[0034] The present invention provides an SMA-driven multi-degree-of-freedom intelligent electric wrench, which has the following beneficial effects:

[0035] 1. The folding assembly of the present invention can be folded or stretched under the action of the SMA spring, and always maintains at least three corners stretched. It can realize the fastening and removal of hexagonal screw parts of different diameters without replacing the assembly, greatly improving the portability and working efficiency of the hexagonal wrench, and at the same time helping to control its manufacturing cost.

[0036] 2. The folding and unfolding of the folding and unfolding assembly of the present invention is controlled by the SMA spring, which heats up when it is powered on and cools down when it is powered off. The structure is simple, lightweight, efficient and environmentally friendly.

[0037] 3. The bending unit of the present invention makes the position and posture of the folding assembly adjustable, which can adapt to the working environment of narrow and complex space; at the same time, the operator can control the wrench in a position and posture that is easy to operate, further improving work efficiency, and at the same time reducing the burden on the operator's wrist, reducing the difficulty and labor intensity of disassembling and assembling hexagonal screw parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of the present invention;

[0039] Figure 2 It is a partial enlarged structural schematic diagram of the present invention;

[0040] Figure 3 This is an axonometric structural diagram of the folding assembly of the present invention in an unfolded state;

[0041] Figure 4 It is a bottom view structural diagram of the foldable assembly of the present invention in the unfolded state;

[0042] Figure 5 This is a schematic diagram of the axonometric structure of the folding assembly of the present invention in a folded state;

[0043] Figure 6 It is a bottom view of the structure of the folding assembly of the present invention in the folded state.

[0044] In the picture:

[0045] 2. Motor switch, 3. Power switch, 6. Thermal strip, 7. Solid tube, 8. Drive shaft, 9. Radiator, 10. First universal joint assembly, 11. Second universal joint assembly, 12. SMA spring, 13. Folding assembly, 14. Center shaft, 15. Mounting rod, 16. Positioning ring, 17. First input universal yoke, 18. First output universal yoke, 19. Second input universal yoke, 20. Second output universal yoke, D. Variable aperture unit, E. Bending unit. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] An SMA driven multi-degree-of-freedom intelligent electric wrench, such as Figures 1 to 6 As shown, its structural relationship is as follows: a mounting cavity is provided in the handle, the motor and power supply are fixedly installed in the mounting cavity, and the output end of the motor is axially connected to the front end of the transmission shaft 8;

[0048] The handle enables the operator to hold the electric wrench conveniently while protecting the internal structure and improving the overall stability of the structure;

[0049] The above-mentioned SMA-driven multi-degree-of-freedom intelligent electric wrench is provided with a variable-caliber unit D including a folding and unfolding component 13, an SMA spring 12, a heat-conducting strip 6, a mounting rod and a heat sink 9;

[0050] The mounting rod is a hollow tubular structure, which is sleeved outside the transmission shaft 8 with a gap between the transmission shaft 8 and the front end thereof is fixed to the handle; the radiator 9 is arranged around the circumference of the mounting rod and is fixed to the mounting rod;

[0051] The folding and unfolding assembly 13 is connected to the rear end of the transmission shaft 8 via the central shaft 14. The motor drives the folding and unfolding assembly 13 to rotate around the axis of the central shaft 14.

[0052] The SMA spring 12 is electrically connected to the power supply and is connected to the heat sink 9 through the heat conductive strip 6 for heat exchange. When the SMA spring 12 is powered on, it heats up and contracts, driving the folding assembly 13 to fold and retract until the folding assembly 13 can be placed in the hexagonal hole of the threaded part. When the power is off, it cools down and expands, driving the folding assembly 13 to expand and open until the folding assembly 13 is engaged with the hexagonal hole.

[0053] Preferably, the folding and unfolding assembly 13 includes six folding and unfolding units of a triangular frame structure;

[0054] The six folding units are arranged and assembled around the circumference of the central axis 14. The vertices of the folding units near the central axis 14 are slidably connected to the connecting posts and are rotatably connected to the central axis 14 through the connecting posts. A rotating pair is formed between the folding units and the central axis 14 to support the folding units to swing up or down, and a sliding pair is formed between the folding units and the connecting posts to support the folding units to slide toward or away from the central axis 14 along the connecting posts.

[0055] The adjacent foldable units are hinged at their junctions, forming a foldable assembly 13 that has a hexagonal pyramidal structure when fully extended.

[0056] When the folding assembly 13 is in any posture, at least three corners are extended to accommodate hexagonal sockets of different sizes;

[0057] The six folding units are divided into three adjacent pairs, and each pair of folding units is equipped with an SMA spring 12. The two ends of the SMA spring 12 are respectively connected to the two vertices of the non-hinged edges of the corresponding pair of folding units. When the SMA spring 12 is powered on, it heats up and contracts, driving the corresponding pair of folding units to fold and close. When the power is off, it cools down and stretches, driving the corresponding pair of folding units to stretch and open.

[0058] Preferably, a bending unit E is further provided between the central shaft 14 and the rear end of the transmission shaft 8;

[0059] The bending unit E has bending adjustment and shaping functions, and transmits the rotation output by the motor to the folding assembly 13 via the transmission shaft 8 and the central shaft 14 , driving the folding assembly 13 to rotate around the axis of the central shaft 14 .

[0060] Preferably, the bending unit E includes a first universal joint assembly 10, a second universal joint assembly 11, a positioning ring 16 and a solid tube 7;

[0061] The first and second universal joint assemblies 10 and 11 each include a pair of cross-type universal joints sharing a central universal yoke. A first input universal yoke 17 at the input end of the first universal joint assembly 10 is axially coupled to the rear end of the transmission shaft 8. A first output universal yoke 18 at the output end is axially coupled to a second input universal yoke 19 at the input end of the second universal joint assembly 11. A second output universal yoke 20 at the output end of the second universal joint assembly 11 is axially coupled to the central shaft 14.

[0062] The first input universal yoke 17, the first output universal yoke 18, the second input universal yoke 19 and the second output universal yoke 20 are all rotatably sleeved with a positioning ring 16 forming a rotation pair around their own axis.

[0063] The positioning ring 16 is fixed by the solid tube 7 and can adjust its posture following the bending of the solid tube 7 .

[0064] The first universal joint group 10 and the second universal joint group 11 provide the folding assembly 13 with the freedom of position and posture adjustment to adapt to the working environment in a narrow or complex space. During the adjustment process, the solid tube 7 should be adaptively bent and adjusted; after the adjustment is completed, the solid tube 7 is solidified, and the first universal joint group 10 and the second universal joint group 11 are limited in position during the process of the motor driving the folding assembly 13 to rotate, allowing only the first input universal joint fork 17, the first output universal joint fork 18, the second input universal joint fork 19 and the second output universal joint fork 20 to rotate around their own axes. The first universal joint group 10 and the second universal joint group 11 both have the function of offsetting the rotational differential, so that the motor can drive the folding assembly 13 to rotate around the axis of the central axis 14. At the same time, the first universal joint group 10 and the second universal joint group 11 are provided to enable the bending unit E to provide more degrees of freedom of movement, thereby making the position and posture adjustment of the folding assembly 13 more flexible.

[0065] Preferably, the front end of the solid tube 7 is fixedly installed, and the end thereof is a forked structure, and the forked structures are respectively fixedly connected to each positioning ring 16 .

[0066] Preferably, the front end of the solid tube 7 is fixedly connected to the radiator 9 via a heat conducting strip 6 .

[0067] Preferably, the solid tube 7 is a gooseneck tube.

[0068] Preferably, the SMA spring 12 is connected to the heat conducting strip 6 through the solid tube 7 for heat exchange.

[0069] Preferably, a motor switch 2 for controlling the operation of the motor and a power switch 3 for controlling the operation of the SMA spring 12 are provided at the tail end of the handle.

[0070] Preferably, the heat sink 9 includes copper fins that are evenly and densely distributed.

[0071] The use of the SMA-driven multi-degree-of-freedom intelligent electric wrench to tighten or remove hexagonal screw parts includes the following processes:

[0072] In the first step, the SMA spring 12 is energized by the power switch 3 , so that the SMA spring 12 heats up and contracts, driving the folding assembly 13 to fold and close.

[0073] In the second step, according to the needs of the working environment, the fixing tube 7 is bent and adjusted so that the folding assembly 13 is directly opposite to the hexagonal hole of the hexagonal threaded part.

[0074] In the third step, the folding assembly 13 is inserted into the hexagonal hole, and the SMA spring 12 is then powered off by the power switch 3; the heat of the SMA spring 12 is transferred to the radiator 9 through the fixing tube 7 and the heat conducting strip 6, and the heat is quickly dissipated under the action of the radiator 9. The SMA spring 12 cools down and stretches, driving the folding assembly 13 to stretch and open, and firmly engage in the hexagonal hole.

[0075] In the fourth step, the operation of the motor is controlled by the motor switch 2. Under the limiting action of each positioning ring 16, the power of the motor is transmitted to the folding assembly 13 through the transmission shaft 8, the first universal joint group 10, the second universal joint group 11 and the center shaft 14, driving the folding assembly 13 to rotate around the axis of the center shaft 14 to achieve the tightening or disassembly of the hexagonal screw part.

[0076] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0077] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An SMA-driven multi-degree-of-freedom intelligent electric wrench, wherein a mounting cavity is provided in the handle, a motor and a power supply are fixedly mounted in the mounting cavity, an output end of the motor is axially coupled to the front end of a transmission shaft (8), and is characterized in that: A variable-caliber unit (D) is provided, which includes a folding assembly (13), an SMA spring (12), a heat-conducting strip (6), a mounting rod, and a heat sink (9); The mounting rod is a hollow tubular structure, which is sleeved outside the transmission shaft (8) and has a gap between the mounting rod and the transmission shaft (8). The front end of the mounting rod is fixedly mounted on the handle; the radiator (9) is arranged around the circumference of the mounting rod and is fixedly mounted on the mounting rod; The folding and unfolding assembly (13) is connected to the rear end of the transmission shaft (8) via a central shaft (14), and the motor drives the folding and unfolding assembly (13) to rotate around the axis of the central shaft (14); The SMA spring (12) is electrically connected to the power supply and is connected to the heat sink (9) through the heat conductive strip (6) for heat exchange. When the SMA spring (12) is powered on, it heats up and contracts, driving the folding assembly (13) to fold and retract until the folding assembly (13) can be placed in the inner hexagonal hole of the threaded part. When the power is turned off, it cools down and expands, driving the folding assembly (13) to expand and open until the folding assembly (13) is engaged with the inner hexagonal hole.

2. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 1, characterized in that: The folding and unfolding assembly (13) comprises six folding and unfolding units with triangular frame structures; The six folding units are arranged and assembled along the circumference of the central axis (14); the vertices of the folding units close to the central axis (14) are connected to the connecting column in a sliding manner and are connected to the central axis (14) in a rotational manner through the connecting column; a rotation pair is formed between the folding unit and the central axis (14) to support the folding unit to swing up or down, and a sliding pair is formed between the folding unit and the connecting column to support the folding unit to slide toward or away from the central axis (14) along the connecting column; The spliced ​​edges of the adjacent folding units are hinged with the intersection line as the rotation axis, forming the folding assembly (13) having a hexagonal pyramid-like structure when fully extended and opened; The six folding units are divided into three adjacent pairs, and each pair of the folding units is equipped with an SMA spring (12). The two ends of the SMA spring (12) are respectively connected to the two vertices of the non-hinged sides of the corresponding pair of folding units. When the SMA spring (12) is powered on, it heats up and contracts, driving the corresponding pair of folding units to fold and close. When the power is off, it cools down and stretches, driving the corresponding pair of folding units to stretch and open.

3. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 1 or 2, characterized in that: A bending unit (E) is further provided between the central shaft (14) and the rear end of the transmission shaft (8); The bending unit (E) has bending adjustment and shaping functions, and transmits the rotation output by the motor to the folding assembly (13) via the transmission shaft (8) and the central shaft (14), driving the folding assembly (13) to rotate around the axis of the central shaft (14).

4. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 3, characterized in that: The bending unit (E) comprises a first universal joint assembly (10), a second universal joint assembly (11), a positioning ring (16) and a solid tube (7); The first universal joint assembly (10) and the second universal joint assembly (11) each include a pair of cross-type universal joints sharing a central universal joint fork; a first input universal joint fork (17) at the input end of the first universal joint assembly (10) is axially coupled to the rear end of the transmission shaft (8), a first output universal joint fork (18) at the output end is axially coupled to a second input universal joint fork (19) at the input end of the second universal joint assembly (11), and a second output universal joint fork (20) at the output end of the second universal joint assembly (11) is axially coupled to the central shaft (14); The first input universal yoke (17), the first output universal yoke (18), the second input universal yoke (19) and the second output universal yoke (20) are all rotatably sleeved with the positioning ring (16) forming a rotation pair around their own axis. The positioning ring (16) is installed and fixed via the solid tube (7), and can adjust its posture following the bending of the solid tube (7).

5. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 4, characterized in that: The front end of the solid tube (7) is fixedly installed, and the end is a bifurcated structure, and the bifurcated structure is respectively fixedly connected to each of the positioning rings (16).

6. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 5, characterized in that: The front end of the solid tube (7) is fixedly connected to the radiator (9) via the heat conducting strip (6); The SMA spring (12) is connected to the heat-conducting strip (6) through the solid tube (7) for heat exchange.

7. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 5 or 6, characterized in that: The solid tube (7) is a gooseneck tube.

8. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 1, characterized in that: The tail end of the handle is provided with a motor switch (2) for controlling the operation of the motor, and a power switch (3) for controlling the operation of the SMA spring (12).

9. The SMA-driven multi-degree-of-freedom intelligent electric wrench according to claim 1, characterized in that: The radiator (9) comprises copper radiating fins that are evenly and densely distributed.

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