Electric screwing wrench and bolt / nut screwing method

Abstract

The invention discloses an electric screwing wrench and a control method thereof, and aims to solve the technical problem that a traditional electric wrench cannot be applied under the condition that the screwing space of a bolt cap / nut is limited. The screwing groove is formed in the corresponding end of the handle and comprises two opposite fork plates, and the push plates are arranged in the screwing groove in an array mode along a vertical line perpendicular to the two fork plates of the screwing groove. The driving motors are arranged in the handle and used for correspondingly driving the push plates to stretch out and draw back along the plane where the fork plates parallel to the screwing grooves are located, and the controller is used for controlling the rotating speed direction and the rotating time sequence of the driving motors. According to the electric screwing wrench, by outputting a specific displacement control sequence, the push plate is driven to correspondingly stretch out and draw back, and then bolt caps / nuts are pushed to rotate, so that the limitation of a narrow installation space is broken through, and the installation efficiency of the bolt caps / nuts is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of hardware tools, and in particular to an electric screwdriver and a bolt / nut screwing method. Background Art

[0002] Gas insulated switchgear (GIS) is a primary device in a substation besides the transformer. During installation, the gas insulated switchgear needs to be bolted in a narrow space. With the development of power tools, electric wrenches have gradually replaced manual tools and are widely used in industrial manufacturing and maintenance. By using electric wrenches to tighten workpieces such as bolts or nuts, the bolt tightening efficiency can be greatly improved compared to manual wrenches.

[0003] However, bolts / nuts in different installation positions will cause huge differences in the tightening operation of the bolts / nuts. In the process of implementing the technical solution in the embodiment of the present application, the inventors found that the traditional electric wrench has at least the following technical problems: the traditional electric wrench is large in size and the drill bit needs to be nested outside the bolt cap / nut when in use. Therefore, it is necessary to reserve space for the electric wrench along the screw direction of the bolt, that is, along the axial direction of the bolt. In the case where the components of the gas-insulated switchgear are closely arranged and the installation space is limited, the space for the electric wrench cannot be guaranteed, which makes the electric wrench tool unusable. In other special installation operation scenarios, due to limited space, even ratchet wrenches with extremely small strokes cannot be used, and they can only be tightened manually bit by bit with an open-end wrench, which is inefficient and requires a lot of manual labor.

[0004] The information disclosed in this background technology section is only used to deepen the understanding of the background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] In view of at least one of the above technical problems, the present disclosure provides an electric screwing wrench and a control method thereof, aiming to solve the technical problem that traditional electric wrenches are not applicable under the condition of limited space for screwing bolts / nuts.

[0006] According to one aspect of the present disclosure, there is provided an electric screwdriver, which includes a handle, a screwing groove provided at the corresponding end of the handle and including two opposite fork plates, a plurality of push plates arranged in the screwing groove along a vertical array perpendicular to the two fork plates of the screwing groove, a plurality of drive motors provided in the handle and respectively used to drive the push plates to extend and retract along a plane parallel to the fork plates of the screwing groove, and a controller for controlling the speed direction and rotation timing of each of the drive motors.

[0007] In some embodiments of the present disclosure, the screwing groove further includes two oppositely arranged guide plates perpendicular to the two fork plates, and a plurality of guide protrusions are arrayed on the guide plates for limiting the moving direction of the push plate.

[0008] In some embodiments of the present disclosure, the guide protrusions are symmetrically arranged at corresponding positions on the opposite surfaces of the two guide plates.

[0009] In some embodiments of the present disclosure, the guide protrusions are correspondingly and vertically fixed between the two guide plates.

[0010] In some embodiments of the present disclosure, the end surface of the push plate used to contact the bolt nut / nut to be tightened has a certain roughness, and the number of the push plates satisfies that at least two of the push plates are in contact with a single edge surface corresponding to the bolt nut / nut to be tightened at the initial moment.

[0011] In some embodiments of the present disclosure, a transmission mechanism for driving the push plate to extend and retract is provided between the drive motor and the push plate. An externally threaded rod or an internally threaded tube is coaxially fixed to the power output shaft of the drive motor, and an internally threaded tube or an externally threaded rod threadedly connected to the externally threaded rod is fixed to the corresponding end of the push plate.

[0012] In some embodiments of the present disclosure, the power of the micro motor matches the top pressure when the bolt / nut is tightened, and an overcurrent protection is provided.

[0013] According to another aspect of the present disclosure, a bolt / nut tightening method is provided, which comprises the following steps: (1) The controller obtains the profile information of the bolt cap / nut to be screwed, including the number of corners and diameter, and adjusts the extension position of each push plate according to the profile information until the fitting profile of the end of each push plate matches the outer profile of the bolt cap / nut to be screwed, and each push plate is arranged symmetrically with respect to the corresponding middle plane of the screwing groove; (2) The rotation direction of the drive motor is set according to the installation / disassembly requirements of the bolt cap / nut, and the controller outputs a displacement control sequence for controlling each of the drive motors according to the set speed V. The displacement control sequence uses the N-degree rotation angle of the bolt cap / nut as a basic control sequence unit, and repeatedly outputs the basic control sequence unit; wherein N=360° / the number of corners of the bolt cap or nut; and the speed V is proportional to the output frequency of the basic control sequence unit; (3) Each of the driving motors synchronously responds to the displacement control sequence and correspondingly drives the push plate to extend and retract to push the bolt cap / nut to rotate.

[0014] In some embodiments of the present disclosure, the controller is connected to a communication channel with buttons and a screen for inputting control parameters and displaying parameters.

[0015] One or more technical solutions provided in the embodiments of the present application have at least any of the following technical effects or advantages: The bolt cap / nut is driven to rotate through the specific telescopic movement of the push plate, thus avoiding the problem that traditional wrenches require a large stroke and cannot adapt to narrow installation spaces, resulting in difficulty and inefficiency in screwing the bolt cap / nut. Compared with traditional wrenches, the efficiency of screwing the bolt cap / nut can be greatly improved without the need for a working stroke, shortening the installation period and saving labor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of an electric wrench in one embodiment of the present application.

[0017] Figure 2 This is a schematic diagram of part of the tightening process of an electric wrench in one embodiment of the present application.

[0018] In the above figures, 1 is a handle, 2 is a screwing groove, 21 is a fork plate, 22 is a guide plate, and 3 is a push plate. DETAILED DESCRIPTION

[0019] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on this application. The "connection" and "coupling" involved in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0020] In order to better understand the technical solution of the present application, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] In order to solve the problem that the traditional electric wrench has a requirement for the use space, cannot be used in the limited working environment when tightening the bolt cap / nut, and the use of a manual wrench is time-consuming and labor-intensive, this example discloses an electric screwing wrench, see Figure 1 , which comprises a handle 1, and a screwing groove 2 is provided at the end of the handle 1. The handle 1 and the screwing groove 2 are an integrated structure, and the screwing groove is placed outside the bolt cap / nut to be screwed to realize the screwing of the bolt cap / nut, that is, when in use, the electric wrench is perpendicular to the axial direction of the bolt, thereby making the electric wrench disclosed by the present invention not subject to the operating condition that the axial space of the bolt is limited, and breaking through the limitation that the traditional manual wrench needs a large stroke operating space, so that the electric wrench can quickly realize the tightening or loosening of the bolt cap / nut in a small space.

[0022] For details, see Figure 1 The screwing groove 2 is arranged at the end side of the handle 1 and is fixedly connected to the handle 1. The screwing groove 2 includes two fork plates 21 arranged opposite to each other, and the screwing operation range of the electric wrench can be limited by the fork plates 21, so that the screwing operation of the bolt cap / nut is realized after the screwed bolt cap / nut is correspondingly located in the screwing groove space range between the two fork plates 21. Among them, the distance between the two fork plates 21 is greater than the maximum diameter of the bolt cap / nut applicable to the electric wrench, so that the bolt cap / nut can be embedded in the space range between the two fork plates 21.

[0023] Taking into account that the screwing stroke of the wrench is also limited under the conditions of a restricted working space, for this reason, in the present embodiment, a plurality of push plates 3 are arranged between the two fork plates 21 of the screwing groove 2, and each push plate 3 is arranged along a vertical array perpendicular to the two fork plates 21, and each push plate 3 is respectively arranged in parallel with the fork plates 21, and through the contact between the push plates 3 and the outer edge contour of the bolt cap / nut, the bolt cap / nut is pushed to rotate when the push plates 3 are correspondingly extended and retracted. Therefore, when using the electric wrench, it is only necessary to place the screwing groove 2 outside the bolt cap / nut to be screwed, and make each push plate 3 correspondingly fit and contact with the outer edge of the bolt cap / nut to be screwed, and under the action of the push plates 3, there is no need to rotate the handle of the electric wrench, so as to achieve the tightening or loosening of the bolt cap / nut, thereby solving the problem that the traditional wrench has special requirements for the working stroke in a restricted space and cannot or is difficult to easily complete the tightening or loosening of the bolt cap / nut.

[0024] Among them, since the rotation of the bolt cap / nut depends on the reliable extension and contraction of each push plate 3, in order to ensure the certainty of the extension and contraction path of each push plate 3 and avoid mutual interference between the push plates or displacement of the push plates after being subjected to force, in this embodiment, the screwing groove 2 also includes two relatively arranged guide plates 22, and the two guide plates 22 are respectively perpendicular to the two fork plates 21. Each push plate 3 is arranged within the space enclosed by the guide plates 22 and the fork plates 21, and the overall movement range of each push plate is limited by the two fork plates and the two guide plates; and in order to avoid position interference and friction between the push plates, in this embodiment, a plurality of guide protrusions are relatively arranged at the two guide plates, and the two sides of the guide protrusions are respectively in contact with the adjacent two push plates, so that the gap between the adjacent two push plates 3 is consistent with the thickness of the guide protrusions, thereby avoiding excessive contact area between the push plates, resulting in increased friction and wear of the push plates. At the same time, guide grooves are formed between the guide protrusions to limit the moving path of the push plates, so that the movements between the push plates are relatively independent, avoiding adverse mutual influence. Among them, in this example, the guide convex pieces are respectively arranged at corresponding positions on the opposite surfaces of the two guide plates symmetrically, that is, the guide convex pieces on the two guide plates correspond to each other, and there is a space interval between the two corresponding guide convex pieces, forming a gap between the two push plates. In some other embodiments, the guide convex piece array is arranged between the opposite surfaces of the two guide plates, perpendicular to the two guide plates and fixedly connected to the opposite surfaces of the two guide plates at both ends, thereby improving the force strength of the guide convex piece relative to the two independently arranged and one-to-one corresponding guide convex pieces.

[0025] In addition, in this embodiment, the end surface of each push plate 3 that is used to contact the bolt cap / nut to be screwed has a certain degree of roughness, so that when the bolt cap / nut to be screwed is pushed by its telescopic movement, a certain friction force can be generated between its end and the bolt cap / nut, ensuring the effective transmission of the thrust to the bolt cap / nut to avoid slipping. In addition, in this embodiment, a total of eight push plates 3 are provided. In some other embodiments, the number of push plates 3 is sufficient to ensure that at least two push plates are in reliable contact with a single edge surface of the bolt cap / nut to be screwed at the initial moment, thereby increasing the pushing pressure of the push plate on the single edge surface of the bolt cap / nut, ensuring that the bolt cap / nut can be effectively rotated under the push of the push plate.

[0026] In order to realize the corresponding extension and retraction of the push plate 3 to push the bolt cap / nut to be screwed, in this embodiment, the handle 1 is provided with a number of driving motors that is the same as the number of push plates, each driving motor adopts a strong magnetic micro motor, and the power of each micro motor matches the top pressure when the bolt is screwed and is provided with overcurrent protection. Each driving motor corresponds to each push plate 3 through a transmission mechanism to drive the push plate to achieve extension and retraction in a plane parallel to the fork plate. Specifically, in this embodiment, the transmission mechanism between the push plate and the driving motor includes an external threaded tube coaxially fixedly connected to the power output shaft of the driving motor, and an internal threaded tube connected to the corresponding end of the push plate. The internal threaded tube is threadedly connected to the external threaded tube, and the end of the internal threaded tube is correspondingly fixed to the center position of the end of the push plate. Therefore, when the driving motor outputs power, the external threaded tube connected to the power output shaft of the driving motor rotates accordingly. Since the push plate is limited by the guide protrusion, the fork plate and the guide plate, the internal threaded tube connected to the push plate is correspondingly screwed in or out along the external threaded tube, thereby realizing the extension and retraction of the push plate. In some other embodiments, the power output shaft of the driving motor is coaxially fixedly connected to the internal threaded tube, and the external threaded tube threadedly connected to the internal threaded tube is fixedly connected to the center position of the corresponding end of the push plate. Similarly, when the driving motor outputs power, the extension and retraction of the push plate is achieved through the cooperation of the internal threaded tube and the external threaded tube.

[0027] Since the screwing action of the bolt cap / nut to be screwed requires the orderly coordinated power output of each push plate, that is, each drive motor, a controller for controlling the speed and rotation timing of each drive motor is provided in the handle in this example. The controller outputs a corresponding control series to drive each push plate to move in coordination to push the bolt cap / nut to rotate as required. In this embodiment, a battery compartment is provided at the other end of the handle for assembling a mobile power supply to power the electric screw wrench; in some other embodiments, the battery compartment is provided with a power connector, which can be directly powered by the mains when the mobile power supply is insufficient or there is no mobile power supply.

[0028] In addition, this example also discloses a control method of the electric screwdriver, which specifically includes the following steps: (1) The controller obtains the profile information of the bolt cap / nut to be tightened, including the number of edges and diameters.

[0029] In order to realize the applicability of the electric screwing wrench to bolt caps / nuts of different diameters, in this embodiment, the electric screwing wrench first obtains the size profile information of the bolt cap / nut to be screwed before use. In order to facilitate the controller to obtain the corresponding profile information of the bolt cap / nut to be screwed, in this example, the handle is provided with a button and a screen connected to the controller for communication, which are used to input control parameters and display control information. Specifically, in this embodiment, the number of edges and corners of the bolt cap or nut to be screwed and the diameter of the circumscribed circle of the bolt cap / nut to be screwed are input to the controller through the button, and the controller automatically fits and calculates the outer edge profile of the bolt cap / nut to be screwed. According to the outer edge profile obtained according to the profile information, the extension position of each push plate is adjusted accordingly, so that the fitting profile between the ends of each push plate matches the outer profile of the bolt cap / nut to be screwed.

[0030] In this embodiment, at the initial moment, the end faces of each push plate are in the same plane. After the contour information of the bolt nut / nut to be tightened is input, the controller outputs a control instruction to each drive motor accordingly. The drive motor responds to the control instruction and drives each push plate to extend a corresponding length, and each push plate is arranged symmetrically about the corresponding middle surface of the tightening groove, so that the end of each push plate can be tightly fitted and contacted with the bolt nut / nut to be tightened.

[0031] (2) The rotation direction of the drive motor is set according to the installation / disassembly requirements of the bolt cap / nut, and the controller outputs a displacement control sequence for controlling each drive motor according to the set speed V.

[0032] After each push plate is adjusted into position according to the profile information of the bolt cap / nut to be screwed, the installation / disassembly requirement is input to the controller through the button on the handle, and the controller automatically converts the requirement into the rotation direction of the bolt cap / nut; after pressing the start button, the controller calculates the motion trajectory of the bolt cap / nut screwing N degrees of rotation angle according to the profile information of the bolt cap / nut to be screwed, where N=360° / number of corners of the bolt cap or nut; according to the change data of the motion trajectory and the vertical distance between the corresponding push plates, the controller samples and outputs the basic control sequence unit, and the drive motor drives the push plate to complete the corresponding telescopic action by responding to the basic control sequence unit, and pushes the bolt cap / nut to screw N degrees of rotation angle. Since the outer edge contour position of the bolt cap / nut coincides with the initial contour position after the bolt cap / nut rotates N degrees of rotation angle, the controller repeatedly outputs the basic control sequence unit, that is, a plurality of basic control sequence units form a displacement control sequence, so as to realize the rotation of the bolt cap / nut by the corresponding number of circles. In this embodiment, the number of corners of the nut to be screwed is 6, so N is 60°, that is, the basic control sequence unit realizes the rotation of the nut at an angle of 60 degrees, see Figure 2 After the nut is rotated 60 degrees, its contour position is consistent with the starting contour position. Therefore, by repeating the basic control sequence 6 times, the nut can be rotated 360 degrees, that is, one circle.

[0033] In addition, in this embodiment, when the speed V of the electric screwdriver is not set, the controller outputs the basic control sequence unit with the default timing, and the electric screwdriver rotates the nut at the default speed; in some other embodiments, the screwing speed V of the electric screwdriver can be set by pressing a button, and the speed V is proportional to the output frequency and timing of the basic control sequence unit. When the speed V is increased / decreased, the controller correspondingly increases / decreases the output frequency and timing interval of the basic control sequence unit.

[0034] (3) Each drive motor synchronously responds to the displacement control sequence and correspondingly drives the push plate to extend and retract to push the bolt cap / nut to rotate. In this embodiment, after the bolt cap / nut is screwed, the reset / off key is pressed, and each push plate is reset to the initial position where the top end is on the same end surface. If no other operation is performed and the reset / off key is pressed again, the electric screwdriver is turned off.

[0035] When the electric screwdriver disclosed in this example is used, after inputting the bolt cap / nut profile information and installation / disassembly requirements, the screwing groove of the electric screwdriver is correspondingly set to the bolt cap / nut to be screwed, and after pressing the start button, the electric screwdriver is tightened manually to ensure that the screwdriver and the bolt cap / nut are stuck, and the screwdriver is moved according to the screwing progress of the bolt cap / nut. The electric screwdriver does not need to be rotated during the whole process, and the bolt cap / nut can be automatically screwed; after the bolt cap / nut stops moving, the electric screwdriver is removed to complete the fixing / disassembly of the bolt cap / nut. In some other embodiments, the tightening requirements for the bolt cap / nut are higher. After the electric screwdriver can no longer drive the bolt cap / nut to move, the electric screwdriver is removed and a manual wrench is used to continue tightening the bolt cap / nut. Since the electric screwdriver has completed most of the bolt cap / nut tightening stroke, the manual wrench only needs a small stroke to achieve the tightening effect. Compared with using a manual wrench alone, the combination of the two can greatly improve the tightening efficiency.

[0036] Although some preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0037] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the inventive concept. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. An electric screwdriver, characterized in that: It includes a handle, a screwing groove provided at the corresponding end of the handle and including two opposite fork plates, a plurality of push plates arranged in the screwing groove along a vertical array perpendicular to the two fork plates of the screwing groove, a plurality of drive motors provided in the handle and respectively used to drive the push plates to extend and retract along a plane parallel to the screwing groove where the fork plates are located, and a controller for controlling the speed direction and rotation timing of each of the drive motors.

2. The electric screwdriver according to claim 1, characterized in that: The screwing groove also includes two oppositely arranged guide plates perpendicular to the two fork plates, and a plurality of guide protrusions are arranged in an array on the guide plates for limiting the moving direction of the push plate.

3. The electric screwdriver according to claim 2, characterized in that: The guide protrusions are symmetrically arranged at corresponding positions of the opposite surfaces of the two guide plates.

4. The electric screwdriver according to claim 2, characterized in that: The guide protrusions are correspondingly and vertically fixed between the two guide plates.

5. The electric screwdriver according to claim 1, characterized in that: The end surface of the push plate used for contacting the bolt nut / nut to be screwed has a certain roughness, and the number of the push plates is such that at least two of the push plates are in contact with a single edge surface corresponding to the bolt nut / nut to be screwed at the initial moment.

6. The electric screwdriver according to claim 1, characterized in that: A transmission mechanism for driving the push plate to extend and retract is provided between the drive motor and the push plate; an externally threaded rod or an internally threaded tube is coaxially fixed to the power output shaft of the drive motor, and an internally threaded tube or an externally threaded rod threadedly connected to the externally threaded rod is fixed to the corresponding end of the push plate.

7. The electric screwdriver according to claim 1, characterized in that: The power of the micro motor matches the top pressure when the bolt / nut is screwed, and an overcurrent protection is provided.

8. A method for tightening a bolt or nut, characterized in that: The method is implemented based on the electric screwdriver according to claim 1, comprising the following steps: (1) The controller obtains the profile information of the bolt cap / nut to be screwed, including the number of corners and diameter, and adjusts the extension position of each push plate according to the profile information until the fitting profile of the end of each push plate matches the outer profile of the bolt cap / nut to be screwed, and each push plate is arranged symmetrically with respect to the corresponding middle plane of the screwing groove; (2) The rotation direction of the drive motor is set according to the installation / disassembly requirements of the bolt cap / nut, and the controller outputs a displacement control sequence for controlling each of the drive motors according to the set speed V. The displacement control sequence uses the N-degree rotation angle of the bolt cap / nut as a basic control sequence unit, and repeatedly outputs the basic control sequence unit; wherein N=360° / the number of corners of the bolt cap or nut; and the speed V is proportional to the output frequency of the basic control sequence unit; (3) Each of the driving motors synchronously responds to the displacement control sequence and correspondingly drives the push plate to extend and retract to push the bolt cap / nut to rotate.

9. The bolt / nut control method according to claim 8, characterized in that: The controller is connected to the communication with buttons and a screen for inputting control parameters and displaying the parameters.

10. The bolt / nut control method according to claim 8, characterized in that: In the step (2), the controller calculates the motion trajectory of the bolt nut / nut to be tightened by fitting according to the profile information of the bolt nut / nut to be tightened, and samples and outputs the basic control sequence unit according to the change data of the vertical distance between the motion trajectory and the corresponding push plate.

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