Adjustable torque electric wrench

Abstract

The present invention provides an adjustable torque electric wrench, comprising a first gearbox, a drive motor, and a torque output mechanism. The first gearbox houses a crank-rocker mechanism and a one-way output mechanism, the crank-rocker mechanism comprising a rotating disk, a first connecting rod, and a second connecting rod. The one-way output mechanism comprises a drive shaft and a one-way ratchet bearing, the drive shaft being fixedly connected to the second connecting rod, which is equipped with a pressure strain gauge. The torque output mechanism comprises a torque output shaft coaxially connected to the one-way ratchet bearing. The present invention converts the clockwise continuous rotation of the drive motor into intermittent clockwise rotation of the torque output shaft, improving production efficiency. Furthermore, the pressure strain gauge is used to monitor and provide feedback on the force acting on the connecting rod, offering certain cost advantages.

Description

Technical Field

[0001] The invention relates to an electric wrench, in particular to an electric wrench with adjustable torque. Background Art

[0002] Electric wrenches are handheld power tools for loading and unloading threaded connections. They are widely used in assembly work in manufacturing industries such as automobiles, tractors, motors and electrical appliances, power machinery, valves, water pumps, and textile machinery. In chemical, cement prefabricated parts, and plastic molding operations, they are used for loading and unloading vacuum tanks, reactors, cement formwork, and demolding of threaded plastic parts in the production process. They can also be used in railway, bridge, and construction projects to install, repair, and replace structures such as cement sleepers, truss nodes, and angle steel scaffolding.

[0003] In the automotive, aerospace, and other fields of assembly, numerous bolt installations require pre-tightening torque. For example, in automobile engine production, the tightening torque of engine screws is a crucial aspect of vehicle repair and maintenance. Whether assembling a new engine or replacing parts during repair, the correct tightening torque is crucial to ensuring proper engine operation and long-term durability. The engine screw tightening torque chart provides ideal torque values ​​for screws in different areas of different vehicle models. Proper use of this chart can effectively avoid problems caused by overtightening or undertightening screws.

[0004] There are also a large number of constant torque electric wrenches used in the vehicle production process. The price of a set of Atlas constant torque wrenches is more than 100,000 yuan, and the price of a constant torque electric wrench for tightening all the bolts on a wheel hub is tens or even millions. Summary of the Invention

[0005] The present invention provides an adjustable torque electric wrench, which includes a first gearbox, a drive motor and a torque output mechanism. A crank rocker mechanism and a one-way output mechanism are installed in the first gearbox housing.

[0006] The crank rocker mechanism includes a rotating disk, a first connecting rod and a second connecting rod, wherein the center of the rotating disk is in transmission connection with the drive motor, the first end of the first connecting rod is rotatably connected to the first end of the second connecting rod, and the second end of the first connecting rod is rotatably connected to a non-center portion of the rotating disk;

[0007] The one-way output mechanism includes a drive shaft and a one-way ratchet bearing. The drive shaft is fixedly connected to the second end of the second connecting rod. The inner ring of the one-way ratchet bearing is provided with a one-way ratchet. The drive shaft is fixedly installed with a one-way ratchet located in the one-way ratchet bearing and unidirectionally rotating with the one-way ratchet.

[0008] The torque output mechanism includes a torque output shaft, and the torque output shaft is coaxially connected to the one-way ratchet bearing.

[0009] Furthermore, a pressure strain gauge is installed on the second connecting rod, and the pressure strain gauge is connected to the wrench control system through a data acquisition system, and the wrench control system is connected to the drive motor.

[0010] Furthermore, the pressure strain gauge is arranged on the surface of the second connecting rod in the rotation direction.

[0011] Furthermore, the driving motor is connected to the rotating disk through a reducer, and both sides of the reducer housing are fixedly connected to the driving motor and the first gearbox housing.

[0012] Furthermore, the one-way ratchet bearing is connected to the torque output shaft through a second gearbox.

[0013] Furthermore, the wrench control system is connected to the reducer and the second gearbox.

[0014] Furthermore, a handle is installed on the first gearbox housing.

[0015] Furthermore, the torque output mechanism further includes an output shaft sleeve and a bearing. The output shaft sleeve is fixedly connected to the first gearbox housing, and the bearing for supporting the torque output shaft is installed in the output shaft sleeve.

[0016] The advantages of the present invention are:

[0017] 1. The adjustable torque electric wrench of the present invention can convert the clockwise continuous rotation of the drive motor into the unidirectional intermittent rotation of the torque output shaft through the unique crank rocker mechanism and one-way output mechanism design, thereby improving the bolt tightening efficiency of the whole vehicle production.

[0018] 2. A pressure strain gauge installed on the second connecting rod provides real-time monitoring and feedback of the force acting on the connecting rod. This data is transmitted to the wrench control system via a data acquisition system. The control system responds quickly based on the preset torque value, automatically adjusting the output power of the drive motor to achieve highly precise torque control.

[0019] 3. Due to its high precision, flexible adjustment, and strong durability, the adjustable torque wrench of the present invention is widely used in various fields such as automotive manufacturing, aerospace, and mechanical assembly. Whether it is large-scale assembly work on the production line or delicate operations during maintenance, it can meet the torque control needs in different scenarios.

[0020] 4. This invention does not utilize a shaft-type dynamic torque sensor. Instead, it monitors force through a pressure strain gauge mounted on the second connecting rod. This avoids the power supply and data transmission issues associated with shaft-type dynamic torque sensors, offering certain structural advantages. This invention boasts a simple structure, low cost, a wide range of applications, and a wide torque range, making it highly marketable and economically valuable. This advantage is particularly significant for companies that frequently change torque settings or handle a wide variety of bolt specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 A control cluster for multiple adjustable torque electric wrenches;

[0023] Figure 2 This is a side view of an adjustable torque electric wrench of the present invention;

[0024] Figure 3 This is an outline diagram of an adjustable torque electric wrench of the present invention;

[0025] Figure 4 A structural diagram of the first gearbox and the torque output shaft connected thereto of the present invention;

[0026] Figure 5 This is a diagram of the internal structure of the first gearbox of the present invention. DETAILED DESCRIPTION

[0027] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0028] In order to fully understand the present invention, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present invention. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0029] Example 1

[0030] This embodiment provides an adjustable torque electric wrench, which includes a first gearbox 4 and a drive motor 2 and a torque output mechanism installed on both sides of the first gearbox. A crank rocker mechanism and a one-way output mechanism are installed in the first gearbox housing 41.

[0031] The crank rocker mechanism is provided with a rotating disk 42, a first connecting rod 43 and a second connecting rod 44. The center of the rotating disk 42 is fixedly connected to the drive motor 2, the first end of the first connecting rod 43 and the first end of the second connecting rod 44 are rotatably connected, and the second end of the first connecting rod 43 is rotatably connected to a non-center point of the rotating disk 42.

[0032] The one-way output mechanism includes a drive shaft 45 and a one-way ratchet bearing 46. The drive shaft 45 is fixedly connected to the second end of the second connecting rod 44. The inner ring of the one-way ratchet bearing 46 is provided with a one-way ratchet. The drive shaft 45 is fixedly installed with a one-way ratchet located in the one-way ratchet bearing 46 and cooperating with the one-way ratchet to rotate in one direction.

[0033] The torque output mechanism includes an output sleeve 5, a torque output shaft 6 and a bearing 7. The torque output shaft 6 is coaxially connected to the one-way ratchet bearing 46. The output sleeve 5 is fixedly connected to the first gearbox housing 41. A bearing 7 for supporting the torque output shaft 6 is installed in the output sleeve 5.

[0034] A pressure strain gauge 44-1 is arranged on the surface of the second connecting rod 44 in the direction of rotation. The pressure strain gauge 44-1 is connected to the wrench control system 03 via the data acquisition system 02, and the wrench control system 03 is connected to the drive motor 2. The pressure strain gauge 44-1 on the second connecting rod 44 can sense the force applied to the second connecting rod 44, thereby determining the torque value of the torque output shaft 6. When the wrench is tightening the screw, the second connecting rod 44 swings clockwise. At this time, the torque output shaft 6 is loaded, and the second connecting rod 44 is also loaded. When the second connecting rod 44 swings counterclockwise, the torque output shaft 6 is stationary and unloaded, and the second connecting rod 44 is unloaded. The strain values ​​in the two situations are different, providing a basis for the wrench control system 03 to control the torque.

[0035] When the drive shaft 45 swings clockwise, the one-way ratchet on the drive shaft 45 also rotates synchronously, thereby driving the inner ring of the one-way ratchet bearing 46 to rotate together, thereby achieving synchronous clockwise rotation of the torque output shaft 6 and the one-way ratchet bearing 46. When the drive shaft 45 swings counterclockwise, the one-way ratchet on the drive shaft 45 slides inside the one-way ratchet bearing 46 without driving the one-way ratchet bearing 46, so that the torque output shaft 6 remains stationary.

[0036] The crank-rocker mechanism converts the continuous clockwise rotation of the drive motor 2 into intermittent clockwise rotation of the torque output shaft 6. During the intermittent periods when the torque output shaft 6 is not rotating, workers can use this time to align the bolts, which are then automatically tightened, thereby improving efficiency.

[0037] A handle 1 is mounted on the first gearbox housing 41 for easy gripping by the operator.

[0038] The data acquisition system determines dynamic torque by monitoring the stress on the gearbox's internal pressure strain gauge 44-1. It also measures the speed of the drive motor 2. The wrench control system 03 receives the motor speed and dynamic torque parameters to control the motor speed, creating a closed-loop control system. During operation, different work kits can be installed on the electric wrench 01 according to different working conditions. The electric wrench 01 includes a display screen and torque control module connected to the wrench control system 03, which provides corresponding torque settings and display options.

[0039] The data acquisition system continuously monitors the force applied to the gearbox's internal pressure strain gauge 44-1, accurately capturing every subtle fluctuation in dynamic torque and providing real-time feedback to the wrench control system 03. The control algorithm, receiving both motor speed and dynamic torque inputs, quickly and accurately calculates the optimal adjustment strategy to maintain system stability and efficiency. This closed-loop control mechanism ensures instant and precise adjustment of motor speed, even under complex and changing operating conditions.

[0040] The design of the Electric Wrench 01 fully embodies the concepts of modularity and flexibility. Users can easily adapt the same electric wrench to different tasks, from tightening bolts to removing nuts, simply by changing the work kit. This design not only reduces tool costs but also significantly improves work efficiency and convenience.

[0041] The display serves as a direct interface between the Electric Wrench 01 and the operator. It not only clearly displays the current operating status, including key information such as motor speed and real-time torque, but also allows the user to set torque through an intuitive interface. Whether adjusting the torque value precisely or selecting a preset mode based on specific application requirements, it can be completed in seconds, greatly simplifying the operation process.

[0042] The torque control module is the core component for precise torque control. Based on the instructions from the wrench control system 03, it finely adjusts the motor output force to ensure that each tightening or loosening operation achieves the preset torque value. This not only protects the workpiece from damage caused by excessive torque, but also ensures a secure and reliable connection. This intelligent control function is particularly important in fields such as precision manufacturing, aerospace, and automotive maintenance.

[0043] To further enhance the user experience and ensure equipment safety, the Electric Wrench 01 is equipped with an intelligent diagnostic and fault warning system. This system monitors the operating status of key components such as the motor, battery, and transmission system in real time, instantly alerting the user if an anomaly is detected and providing appropriate solutions or repair instructions. This not only reduces downtime caused by equipment failure but also effectively extends the life of the electric wrench.

[0044] Example 2

[0045] On the basis of Example 1, this embodiment further includes a reducer 3, through which the drive motor 2 is connected to the rotating disk 42 in a transmission manner. Both sides of the housing of the reducer 3 are fixedly connected to the drive motor 2 and the first gearbox housing 41, and the reducer 3 is connected to the wrench control system 03. The output speed of the drive motor 2 can be further adjusted by the reducer 3, so that the torque output is more stable and accurate. The reducer 3 contains a multi-stage gear transmission mechanism, which, through the engagement of different gears, reduces the speed and increases the torque. This design not only improves the torque output capacity of the electric wrench, but also makes the torque output more controllable, reducing the torque fluctuation and precision degradation caused by excessively high speed.

[0046] Example 3

[0047] This embodiment, based on the first and / or second embodiments, further includes a second gearbox 47 (illustrated schematically). The one-way ratchet bearing 46 is connected to the torque output shaft 6 via the second gearbox 47, which is in turn connected to the wrench control system 03. The torque range and accuracy of the torque output shaft 6 can be further adjusted via the second gearbox 47. Multiple selectable gear combinations are internally configured within the second gearbox 47. By replacing or adjusting these gear combinations, the transmission ratio of the torque output shaft 6 can be flexibly varied to accommodate bolt tightening tasks of varying specifications and requirements.

[0048] Specifically, the second gearbox 47 features a modular design, facilitating assembly and disassembly, as well as gear replacement. It contains multiple gear shafts and corresponding gears, mounted within the gearbox housing via bearings and well lubricated to reduce friction and wear. By rotating or sliding the selector on the gearbox, different gear combinations can be easily switched, enabling quick adjustment of torque output.

[0049] The above describes the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the scope of the technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes, which does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solutions of the present invention are still within the scope of protection of the technical solutions of the present invention.

Claims

1. An adjustable torque electric wrench, the adjustable torque electric wrench (01) comprises a first gearbox (4), a drive motor (2) and a torque output mechanism, characterized in that: A crank rocker mechanism and a one-way output mechanism are installed in the first gearbox housing (41). The crank rocker mechanism is provided with a rotating disk (42), a first connecting rod (43) and a second connecting rod (44); the center of the rotating disk (42) is transmission-connected to the driving motor (2); the first end of the first connecting rod (43) and the first end of the second connecting rod (44) are rotationally connected; and the second end of the first connecting rod (43) is rotationally connected to a non-center portion of the rotating disk (42); The one-way output mechanism comprises a driving shaft (45) and a one-way ratchet bearing (46); the driving shaft (45) is fixedly connected to the second end of the second connecting rod (44); the inner ring of the one-way ratchet bearing (46) is provided with a one-way ratchet; the driving shaft (45) is fixedly installed with a one-way ratchet located in the one-way ratchet bearing (46) and unidirectionally rotating with the one-way ratchet; and a pressure strain gauge (44-1) is installed on the second connecting rod (44); The torque output mechanism includes a torque output shaft (6), and the torque output shaft (6) is coaxially connected to the one-way ratchet bearing (46).

2. The adjustable torque electric wrench according to claim 1, characterized in that: The pressure strain gauge (44-1) is arranged on the surface of the second connecting rod (44) in the rotation direction. The pressure strain gauge (44-1) is connected to the wrench control system (03) through the data acquisition system (02), and the wrench control system (03) is connected to the drive motor (2).

3. The adjustable torque electric wrench according to claim 2, characterized in that: The drive motor (2) is transmission-connected to the rotating disk (42) via a reducer (3), and both sides of the housing of the reducer (3) are fixedly connected to the drive motor (2) and the first gearbox housing (41).

4. The adjustable torque electric wrench according to claim 3, characterized in that: The one-way ratchet bearing (46) is connected to the torque output shaft (6) via a second gearbox (47).

5. The adjustable torque electric wrench according to claim 4, characterized in that: The wrench control system is connected to the reducer (3) and the second gearbox (47).

6. The adjustable torque electric wrench according to claim 1, characterized in that: A handle (1) is mounted on the first gearbox housing (41).

7. The adjustable torque electric wrench according to claim 2, characterized in that: The torque output mechanism further comprises an output shaft sleeve (5) and a bearing (7); the output shaft sleeve (5) is fixedly connected to the first gearbox housing (41); and the bearing (7) for supporting the torque output shaft (6) is installed in the output shaft sleeve (5).

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