A self-positioning nut tightening device and operation method thereof

Abstract

The present invention relates to a self-positioning nut tightening device and an operation method thereof, comprising a base (1) and a tightening mechanism (3), wherein the tightening mechanism (3) is mounted on a sliding mechanism (2) and moves synchronously with the sliding mechanism (2) in a vertical direction, wherein the output shaft end of the tightening mechanism (3) is connected with a double-section universal joint (4), and the double-section universal joint (4) expands and retracts and rotates with the output shaft of the tightening mechanism (3); a sleeve (6) is provided at the end of the double-section universal joint (4); a positioning chuck (7) is provided on the outside of the lower end of the sleeve (6), wherein the chuck is convenient for picking up the nut when it is opened, and can hold the stud when it is contracted, so that the sleeve (6) and the stud axis coincide with each other. The device can make the nut axis coincide with the stud axis under rough positioning by means of the automatic adjustment function of the positioning chuck (7) and the double-section universal joint (4), thereby realizing the mechanical automation of automatically screwing the nut into the stud, and greatly improving the working efficiency and safety performance of the nut tightening process.

Description

Technical Field

[0001] The invention relates to the technical field of general mechanical parts installation, and in particular to a self-positioning nut tightening device and an operating method thereof. Background Art

[0002] At present, the installation process of nuts, especially when installing large nuts above M6, or when the position of the stud axis cannot be accurately located, or the angle of the stud axis cannot be accurately obtained, is to manually screw the nut into the stud first, and then use other tightening tools to tighten it. This method is acceptable when the number of nuts used is small. However, when the nuts are used in large quantities, if each nut needs to be manually screwed into the stud first, it will consume a lot of labor resources, greatly increase the installation cost, and have low operating efficiency, and it is easy to cause safety accidents during the installation process.

[0003] For example, the Chinese invention patent application with publication number CN 107598549 A discloses a nut tightening mechanism, including a mounting bracket for installation on an assembly line, a clamping structure supported on the mounting bracket for clamping the nut, and a screwing structure for rotating the clamped nut, wherein the clamping structure includes a nut chuck having one end for receiving the nut, and the nut chuck can be radially contracted at least at one end with a nut interface to clamp the nut, and the mechanism can realize automatic tightening of the assembly line nut without manual intervention. However, the tightening mechanism is only applicable to the working conditions where the position of the stud on the assembly line can be accurately positioned and there is no inclination between the axis of the stud and the axis of the sleeve, and no effective solution is proposed for the situation where the axis of the stud and the axis of the nut are misaligned or there is an inclination between the axis of the stud and the axis of the sleeve. Summary of the invention

[0004] In order to solve the above technical defects in the prior art, the purpose of the present invention is to provide a self-positioning nut tightening device and its operation method, which can not only automatically complete the whole process of fast screwing in and slow tightening of the nut by machinery when the axis of the stud can be accurately obtained in advance, but also automatically complete the whole process of fast screwing in and slow tightening of the nut by machinery under rough positioning conditions such as the misalignment of the stud center or the inclination of the axis cannot be accurately obtained. The mechanism reduces the manual action of tightening the nut during the nut tightening process, improves the work efficiency and economic benefits of the nut tightening process, and enhances the safety performance of the operation.

[0005] In order to achieve the above-mentioned design objectives, the scheme adopted by the present invention is as follows:

[0006] The first aspect of the present invention provides a self-positioning nut tightening device, comprising a base and a tightening mechanism, wherein the tightening mechanism is installed on a sliding mechanism and moves synchronously with the sliding mechanism in the vertical direction, and the tightening shaft of the tightening mechanism can be extended and rotated; the end section of the output shaft of the tightening mechanism is connected to a double-section universal joint, which can extend and rotate with the output shaft of the tightening mechanism, and can swing within a certain angle range under the action of pressure; a sleeve is provided at the end of the double-section universal joint; a positioning chuck is provided on the outside of the lower end of the sleeve, and a hand grip in the chuck can be easily opened and contracted under the action of an external power. When the hand grip is opened, the center hole is very large, and the nut can pass through the center, which is convenient for picking up the nut; when the hand grip is contracted, the center hole is exactly consistent with the diameter of the cylindrical surface of the stud, and the stud can be well held, causing the sleeve to coincide with the axis of the stud. Through the automatic adjustment function of the positioning chuck and the double-section universal joint, the device can make the nut axis coincide with the stud axis under rough positioning, realizing mechanical automation of automatically screwing the nut into the stud, greatly improving the work efficiency and safety performance of the nut tightening process.

[0007] Preferably, the fixed end of the sliding mechanism 2 is connected to a base and moves vertically up and down.

[0008] In any of the above schemes, preferably, a rubber sleeve is provided on the outside of the double-joint universal joint. The rubber sleeve is bonded and fixed on the outside of the double-joint universal joint, and can provide damping for the joint of the double-joint universal joint within a certain pressure range, so that the mechanism does not shake disorderly during operation.

[0009] In any of the above schemes, preferably, the positioning chuck is a hollow structure, mounted and fixed on the outer cylinder of the sleeve, and is coaxial with the sleeve.

[0010] In any of the above schemes, it is preferred that the tightening mechanism is controlled by a control system. The control system is the central nervous system of the tightening mechanism, through which not only the sliding, positioning, material taking and feeding process control of the mechanism can be realized, but also the tightening method, speed, direction, torque value, angle, time, upper and lower limits and other parameters of the nut can be optimized, and real-time monitoring and feedback can be performed during the operation to ensure the smooth progress of the nut tightening process.

[0011] In any of the above schemes, it is preferred that the sliding mechanism is composed of a slider, a linear guide rail, a slide seat, a transmission mechanism and a pin shaft.

[0012] In any of the above schemes, preferably, the slider is fixed to the base by screws; the linear guide is fixed to the slide by screws, and the linear guide moves in the vertical direction under the guidance of the slider.

[0013] In any of the above solutions, preferably, one end of the transmission mechanism is connected to the base through a pin, and the other end is connected to the slide through a thread. By adjusting the position of the transmission mechanism, the linear guide rail can be moved up and down.

[0014] In any of the above schemes, it is preferred that the sleeve is composed of a sleeve body and a magnet. The magnet can absorb the end face of the nut to achieve material removal.

[0015] In any of the above schemes, it is preferred that the inner lower end of the sleeve body is a square hole matching the shape of the target nut, and the upper end is a round hole. After the nut is inserted into the sleeve, the square hole at the lower end can clamp the nut to make it rotate synchronously.

[0016] In any of the above schemes, preferably, the magnet is glued between the square hole and the inner cylindrical surface of the sleeve body. When the sleeve picks up the nut, after the centers of the sleeve and the nut are aligned, the sleeve can be aligned and sleeved with the nut by light pressure and the magnet attracts the end face of the nut, so that the nut can move synchronously with the sleeve.

[0017] In any of the above schemes, it is preferred that the positioning chuck consists of a chuck and a movable grip. The entire mechanism is fixed to the outer cylindrical surface of the sleeve through the inner hole of the chuck and can rotate and swing with the sleeve. The sleeve can pass through the middle of the chuck grip when it is open, and can hold the stud tightly when it is clamped.

[0018] As an alternative, the positioning chuck is a pneumatic chuck or a hydraulic chuck.

[0019] As an alternative, the base is a fixed frame or a mechanism assembly with an omnidirectional adjustment function.

[0020] As an alternative, the transmission mechanism is selected from a movable cylinder or an oil cylinder or a screw nut pair transmission mechanism or a gear rack transmission mechanism.

[0021] In any of the above solutions, preferably, the number of the mobile grippers is greater than or equal to three.

[0022] A second aspect of the present invention provides an operation process of a self-positioning nut tightening device, which comprises the following steps:

[0023] Step A: The control system is used to adjust the position of the mechanism so that the sleeve is located directly above the nut to be picked up. At this time, the mechanism is located at the upper limit position and the positioning chuck is in an open state;

[0024] Step B: Control the tightening mechanism to make the sleeve rotate at a low speed;

[0025] Step C: Adjust the position of the transmission mechanism so that the tightening mechanism moves downward to the specified position. At this time, under the lateral damping action of the rubber sleeve, each section of the double-section universal joint is in a vertical state, the sleeve covers the nut to be tightened, and the magnet attracts the end face of the nut to realize material removal;

[0026] Step D: Adjust the position of the transmission mechanism so that the tightening mechanism moves to the upper limit position;

[0027] Step E: According to the rough positioning data, adjust the position of the mechanism or the workpiece so that the sleeve is located directly above the target stud;

[0028] Step F: Adjust the position of the transmission mechanism, and move the mechanism downward until the set limit stroke is reached. At this time, the target stud presses against the sleeve and compresses the tightening mechanism upward by a certain length;

[0029] Step G: By controlling the hand grip of the positioning chuck to shrink, under the automatic adjustment of the double-section universal joint, no matter the axis of the sleeve is misaligned with the axis of the target stud, or the axis of the sleeve is at an angle to the axis of the target stud, the hand grip of the positioning chuck can hold the target stud tightly, so that the nut and the target stud are coaxial;

[0030] Step H: Start the tightening mechanism to make it rotate quickly under a small torque state, and the nut is automatically screwed into the target stud during the rotation of the tightening mechanism;

[0031] Step I: After the preset screw-in depth of the nut is reached, the hand grip of the positioning chuck is opened by control;

[0032] Step J: Start the tightening mechanism again to complete the work of completely tightening the nut under a constant torque output state;

[0033] Step K: The mechanism is retracted to prepare for the next operation. Preferably, the self-positioning nut tightening device described in the first aspect of the present invention is used.

[0034] Compared with the prior art, the self-positioning nut tightening device of the present invention has the following advantages and effects:

[0035] 1. The nut tightening device of the embodiment of the present invention can not only mechanically and automatically complete the entire process of screwing in and tightening the nut when the axis of the stud can be accurately obtained in advance, but also can mechanically and automatically complete the entire process of screwing in and tightening the nut under rough positioning conditions such as when the center of the stud is misplaced or the axis inclination cannot be accurately obtained.

[0036] 2. Under the rough positioning condition, the axis of the sleeve 6 is aligned with the axis of the stud through mechanical positioning, thereby reducing the difficulty of screwing the nut into the stud.

[0037] 3. This mechanism reduces the manual action of screwing the nut into the stud during the nut tightening process, thereby reducing the labor intensity during the nut tightening process, improving the work efficiency and economic benefits of the nut tightening process, and improving the safety performance of the operation.

[0038] 4. Through the automatic adjustment function of the positioning chuck and the double-section universal joint, the axis of the nut can be made to coincide with the axis of the stud under rough positioning, realizing the mechanical automation of automatically screwing the nut into the stud, which greatly improves the work efficiency and safety performance of the nut tightening process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of a preferred embodiment of a self-positioning nut tightening device according to the present invention.

[0040] Figure 2 A self-positioning nut tightening device according to the present invention Figure 1 A front view of the preferred embodiment is shown.

[0041] Figure 3 A self-positioning nut tightening device according to the present invention Figure 1 A diagram of the system control interface of the preferred embodiment is shown.

[0042] Figure 4 A self-positioning nut tightening device according to the present invention Figure 1 A schematic structural diagram of the sliding mechanism of the illustrated embodiment.

[0043] Figure 5 A self-positioning nut tightening device according to the present invention Figure 1 A schematic structural diagram of the sleeve of the illustrated embodiment.

[0044] Figure 6 A self-positioning nut tightening device according to the present invention Figure 1 A schematic structural diagram of a positioning chuck of the illustrated embodiment.

[0045] Figure 7 A self-positioning nut tightening device according to the present invention Figure 6 A top view of the positioning chuck of the illustrated embodiment.

[0046] Figure 8 A self-positioning nut tightening device according to the present invention Figure 1 Flow chart of the operation process of the illustrated embodiment.

[0047] Fig. 9 A self-positioning nut tightening device according to the present invention Figure 1 A schematic diagram of the structure of the embodiment shown in which the center of the sleeve and the center of the stud are misaligned.

[0048] Fig.10 A self-positioning nut tightening device according to the present invention Figure 1 The schematic diagram of the structure of the embodiment shown is a state where the axis of the sleeve and the axis of the stud are at an inclined angle. DETAILED DESCRIPTION

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work.

[0050] like Figure 1-Figure 3 As shown, a structural schematic diagram of a preferred embodiment of a self-positioning nut tightening device according to the present invention. The self-positioning nut tightening device of the present invention comprises a base 1 and a tightening mechanism 3, wherein the tightening mechanism 3 is mounted on a sliding mechanism 2 and moves synchronously with the sliding mechanism 2 in the vertical direction, and the tightening shaft of the tightening mechanism 3 can be extended and rotated; the end section of the output shaft of the tightening mechanism 3 is connected to a double-section universal joint 4, which can be extended and rotated with the output shaft of the tightening mechanism 3, and can swing within a certain angle range under the action of pressure; a sleeve 6 is provided at the end of the double-section universal joint 4; a positioning chuck 7 is provided on the outside of the lower end of the sleeve 6, and the hand grip in the chuck can be easily opened and retracted under the action of an external power, and the central hole is large when the hand grip is opened, and the nut can pass through the center, which is convenient for picking up the nut; when the hand grip is retracted, the central hole is just consistent with the diameter of the cylindrical surface of the stud, and the stud can be well held, so that the sleeve and the stud axis coincide. Through the automatic adjustment function of the positioning chuck 7 and the double-section universal joint 4, the device can make the nut axis coincide with the stud axis under rough positioning, realize mechanical automation of automatically screwing the nut into the stud, and greatly improve the work efficiency and safety performance of the nut tightening process.

[0051] In this embodiment, the fixed end of the sliding mechanism 2 is connected to the base 1 and moves up and down in the vertical direction.

[0052] In this embodiment, a rubber sleeve 5 is provided on the outside of the double-joint universal joint 4. The rubber sleeve 5 is bonded and fixed to the outside of the double-joint universal joint 4, and can provide damping for the joint of the double-joint universal joint 4 within a certain pressure range, so that the mechanism does not shake disorderly during the operation movement.

[0053] In this embodiment, the positioning chuck 7 is a hollow structure, which is installed and fixed on the outer cylinder of the sleeve 6 and is coaxial with the sleeve 6.

[0054] In this embodiment, the tightening mechanism 3 is controlled by a control system 8. The control system 8 is the central nervous system of the tightening mechanism 3, through which not only the sliding, positioning, material taking and feeding process control of the mechanism can be realized, but also the tightening method, speed, direction, torque value, angle, time, upper and lower limits and other parameters of the nut can be optimized, and real-time monitoring and feedback can be performed during the operation process to ensure the smooth progress of the nut tightening process.

[0055] As an alternative, the base 1 is a fixed frame or a mechanism assembly with directional adjustment functions. The base 1 of different structures can make the device of the present invention applicable to different occasions.

[0056] See next Figure 4 As shown, according to the self-positioning nut tightening device of the present invention, Figure 1 A schematic structural diagram of the sliding mechanism of the illustrated embodiment.

[0057] In this embodiment, the sliding mechanism 2 is composed of a slider 201 , a linear guide rail 202 , a slide seat 203 , a transmission mechanism 204 and a pin 205 .

[0058] In this embodiment, the slider 201 is fixed to the base 1 by screws; the linear guide 202 is fixed to the slide 203 by screws, and the linear guide 202 moves in the vertical direction under the guidance of the slider 201.

[0059] In this embodiment, one end of the transmission mechanism 204 is connected to the base 1 through a pin 205, and the other end is connected to the slide 203 through a thread. By adjusting the position of the transmission mechanism 204, the linear guide rail can be moved up and down.

[0060] As an alternative, the transmission mechanism 204 may be any linear transmission mechanism such as an air cylinder, an oil cylinder, a screw-nut pair transmission mechanism, or a gear rack transmission mechanism.

[0061] like Figure 5 As shown, according to the self-positioning nut tightening device of the present invention, Figure 1 A schematic structural diagram of the sleeve of the illustrated embodiment.

[0062] In this embodiment, the sleeve 6 is composed of a sleeve body 601 and a magnet 602. The magnet 602 can absorb the end face of the nut to realize material removal.

[0063] In this embodiment, the inner lower end of the sleeve body 601 is a square hole matching the shape of the target nut, and the upper end is a round hole. After the nut is inserted into the sleeve, the square hole at the lower end can clamp the nut to make it rotate synchronously.

[0064] In this embodiment, the magnet 602 is glued between the square hole and the inner cylindrical surface inside the sleeve body 601. When the sleeve picks up the nut, after the centers of the sleeve and the nut are aligned, the sleeve can be aligned and sleeved with the nut by light pressure, and the magnet 602 absorbs the end face of the nut, so that the nut can move synchronously with the sleeve. When the nut is screwed into the stud, the top of the stud can enter the inner cylindrical surface of the upper end of the sleeve, so that the nut can be completely tightened.

[0065] like Figure 6 , Figure 7 As shown, according to the self-positioning nut tightening device of the present invention, Figure 1 A schematic structural diagram of a positioning chuck of the illustrated embodiment.

[0066] In this embodiment, the positioning chuck 7 is composed of a chuck 701 and a movable hand grip 702. The entire mechanism is fixed to the outer cylindrical surface of the sleeve 6 through the inner hole of the chuck 701, and can rotate and swing with the sleeve 6. The hand grip of the chuck can allow the sleeve to pass through the middle when it is open, and can hold the stud tightly when it is clamped.

[0067] In this embodiment, the positioning chuck 7 is a pneumatic chuck or a hydraulic chuck.

[0068] In this embodiment, the number of the mobile grippers 702 is greater than or equal to 3, and experiments have shown that the number of grippers only needs to be more than 3.

[0069] like Figure 8 As shown, according to the self-positioning nut tightening device of the present invention, Figure 1 Flow chart of the operation process of the illustrated embodiment.

[0070] The present invention provides a self-positioning nut tightening device, the operation process of which is as follows:

[0071] Step A: The control system 8 is used to adjust the position of the mechanism so that the sleeve 6 is located directly above the nut to be picked up. At this time, the mechanism is located at the upper limit position and the positioning chuck 7 is in an open state;

[0072] Step B: Control the tightening mechanism 3 to make the sleeve 6 rotate at a low speed;

[0073] Step C: Adjust the position of the transmission mechanism 204 to move the tightening mechanism 3 downward to the specified position. At this time, under the lateral damping action of the rubber sleeve 5, each section of the double-section universal joint 4 is in a vertical state, the sleeve 6 covers the nut to be tightened, and the magnet 602 attracts the end face of the nut to realize material removal;

[0074] Step D: adjusting the position of the transmission mechanism 204 so that the tightening mechanism 3 moves to the upper limit position;

[0075] Step E: According to the rough positioning data, adjust the position of the mechanism or the workpiece so that the sleeve 6 is located directly above the target stud;

[0076] Step F: adjusting the position of the transmission mechanism 204 to move the mechanism downward until the set limit stroke is reached, at which point the target stud presses against the sleeve 6 and compresses the tightening mechanism 3 upward by a certain length;

[0077] Step G: By controlling the hand grip of the positioning chuck 7 to shrink, under the automatic adjustment of the double-section universal joint 4, no matter the axis of the sleeve 6 is misaligned with the axis of the target stud (such as Fig. 9 As shown), or the axis of the sleeve 6 is at an angle to the axis of the target stud (as shown Fig.10 As shown), the hand grip of the positioning chuck 7 can hold the target stud tightly, so that the nut and the target stud are coaxial;

[0078] Step H: starting the tightening mechanism 3 to rotate rapidly under a low torque state, and the nut is automatically screwed into the target stud during the rotation of the tightening mechanism 3;

[0079] Step I: After the preset screw-in depth of the nut is reached, the hand grip of the positioning chuck 7 is opened by control;

[0080] Step J: start the tightening mechanism 3 again, so that it can complete the work of completely tightening the nut under the constant torque output state;

[0081] Step K: The mechanism is retracted to prepare for the next operation. Preferably, the self-positioning nut tightening device described in the first aspect of the present invention is used.

[0082] It is not difficult for a person skilled in the art to understand that the self-positioning nut tightening device and the operating method thereof of the present invention include any combination of the parts in this specification. Due to the limited space and to make the specification concise, these combinations are not introduced in detail one by one here, but after reading this specification, the scope of the present invention constituted by any combination of the parts constituting this specification is self-evident.

Claims

1. A method for operating a self-positioning nut tightening device, comprising the following steps: Step A: adjusting the position of the tightening mechanism (3) through the control system (8) so that the sleeve (6) is located directly above the nut to be picked up, at which time the tightening mechanism (3) is located at the upper limit position and the positioning chuck (7) is in an open state; Step B: controlling the tightening mechanism (3) to rotate the sleeve (6) at a low speed; Step C: adjusting the position of the transmission mechanism (204) so ​​that the tightening mechanism (3) moves downward to a specified position. At this time, under the lateral damping action of the rubber sleeve (5), each section of the double-section universal joint (4) is in a vertical state, the sleeve (6) covers the nut to be picked up, and the magnet (602) attracts the end face of the nut to realize material removal; Step D: adjusting the position of the transmission mechanism (204) so ​​that the tightening mechanism (3) moves to the upper limit position; Step E: According to the rough positioning data, adjust the position of the tightening mechanism (3) or the position of the workpiece so that the sleeve (6) is located directly above the target stud; Step F: Controlling the transmission mechanism (204) to move the tightening mechanism (3) downward until a set limit stroke is reached, at which point the target stud presses against the sleeve (6) and compresses the tightening mechanism (3) upward by a certain length; Step G: by controlling the hand grip of the positioning chuck (7) to retract, under the automatic adjustment of the double-joint universal joint (4), no matter the axis of the sleeve (6) is misaligned with the axis of the target stud, or the axis of the sleeve (6) is at an angle to the axis of the target stud, the hand grip of the positioning chuck (7) can hold the target stud tightly, so that the nut and the target stud are coaxial; Step H: starting the tightening mechanism (3) to rotate rapidly under a low torque state, and the nut is automatically screwed into the target stud as the tightening mechanism (3) rotates; Step I: After the preset screw-in depth of the nut is reached, the hand grip of the positioning chuck (7) is opened by control; Step J: starting the tightening mechanism (3) again, so that the nut is completely tightened under a constant torque output state; Step K: The tightening mechanism (3) is retracted to prepare for the next operation; The self-positioning nut tightening device comprises a base (1) and a tightening mechanism (3), wherein the tightening mechanism (3) is mounted on the sliding mechanism (2) and moves synchronously with the sliding mechanism (2) in the vertical direction, and the end section of the output shaft of the tightening mechanism (3) is connected to a double-section universal joint (4), and the double-section universal joint (4) expands and retracts and rotates with the output shaft of the tightening mechanism (3); a sleeve (6) is provided at the end of the double-section universal joint (4); a positioning chuck (7) is provided on the outside of the lower end of the sleeve (6); the fixed end of the sliding mechanism (2) is connected to the base (1) and moves up and down in the vertical direction; a rubber sleeve (5) is provided on the outside of the double-section universal joint (4); the positioning chuck (7) is a hollow structure and is fixedly mounted on the outer cylinder of the sleeve (6). , coaxial with the sleeve (6); the tightening mechanism (3) is controlled by a control system (8); the sliding mechanism (2) is composed of a slider (201), a linear guide (202), a slide seat (203), a transmission mechanism (204) and a pin (205); the slider (201) is fixed to the base (1) by screws; the linear guide (202) is fixed to the slide seat (203) by screws, and the linear guide (202) moves in a vertical direction under the guidance of the slider (201); one end of the transmission mechanism (204) is connected to the base (1) by a pin (205), and the other end is connected to the slide seat (203) by a thread; the sleeve (6) is composed of a sleeve body (601) and a magnet (602).

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