Tightening mechanism adaptive to screws of different specifications

Abstract

The invention relates to the technical field of intelligent assembly, in particular to a tightening mechanism adaptive to screws of different specifications, which comprises a driving assembly and a tightening gun power assembly mounted at the output end of the driving assembly, and the tightening gun power assembly comprises a servo motor mounted at the output end of the driving assembly. Meanwhile, the distributor can carry out receiving and distributing on screws of various sizes, the tightening gun is matched with a robot to achieve automatic taking and automatic discharging, the tightening gun is matched with a torque sensor, the torque sensor is matched with a torque sensor, and the torque sensor is matched with a torque sensor to achieve automatic feeding and discharging of the screws. The screw tightening state and the tightening torsion value are fed back in time, rejection feedback is conducted on some defective screws, through cooperation of all the components, the screw feeding and tightening device can be suitable for feeding and tightening work of the screws of various sizes, compatibility is good, practicability is high, assembling and tightening of the screws of various sizes can be completed through one device, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent assembly, and particularly relates to a tightening mechanism adapted to screws of different specifications. Background Art

[0002] With the development of the economy and the progress of society, energy conservation, cost reduction, and efficiency improvement have become an inevitable trend and social consensus. Various devices are increasingly developing towards the characteristics of energy saving, convenient use, space saving, safety and high efficiency, and multi-functional in one machine. In the traditional construction machinery industry, most workshops for hydraulic motors supporting planetary reducers still use manual screw tightening, and most screw guns on the market only meet one specification of screws, increasing production costs. This increases the labor intensity and labor costs, and the work efficiency is relatively low.

[0003] The screw tightening mechanism is an important device in the mechanical industry for realizing screw tightening operations. It has a wide range of applications in fields such as automated assembly lines and mechanical equipment maintenance. The working principle of the screw tightening mechanism is mainly based on torque and rotation angle control. During the tightening process, the mechanism applies a certain torque or rotation angle to cause the screw to axially elongate or the connecting piece to be compressed, thereby achieving the fastening effect. At the same time, the mechanism also needs to consider key variables such as the friction coefficient and clamping force to ensure the stability and reliability of the tightening quality.

[0004] The national invention patent application, with the application publication number CN111531358A and the application publication date of August 14, 2020, discloses a screw tightening mechanism. This screw tightening mechanism can automatically screw the screw onto the screw hole position of the workpiece, saving time and effort and reducing production costs; However, the screwdriver of this screw tightening mechanism is fixed to the device, that is, the screwdriver is not easy to replace. Therefore, it cannot be applied to the tightening work of screws of different models. For the hydraulic motor supporting planetary reducer, its application scenarios are different, and the models of the reducer and the screws used in the reducer are also different. Therefore, using the above screw tightening mechanism cannot be applied to the screw tightening work of multiple models of reducers, and the compatibility is poor. Summary of the Invention

[0005] Aiming at the above-mentioned shortcomings of the prior art, the present invention provides a tightening mechanism adapted to screws of different specifications. Most screw guns on the market only meet one specification of screws, increasing production costs. Therefore, through the cooperation of various components, the present invention can be applied to the feeding and tightening work of screws of various sizes, with good compatibility and high practicability. Multiple screw assemblies and tightenings can be completed by one device, reducing production costs.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: The present invention provides a tightening mechanism adapted to different specifications of screws, including a driving assembly and a tightening gun power assembly installed at the output end of the driving assembly. The tightening gun power assembly includes a servo motor installed at the output end of the driving assembly, and also includes a self-locking chuck installed at the output end of the servo motor. A cross bit is detachably installed in the self-locking chuck. The screw clamping assembly includes a plurality of screw clamping mechanisms arranged below the cross bit and capable of reciprocating horizontally. Each of the screw clamping mechanisms includes guide posts symmetrically distributed in pairs and opposite to the position of the cross bit. An O-ring is sleeved outside the two symmetric guide posts. The screw feeding and discharging assembly includes a screw feeding tooling arranged below the screw clamping mechanism. A plurality of screws are detachably arranged on the screw feeding tooling. The screw feeding and discharging assembly further includes a suction nozzle arranged above the screw feeding tooling and capable of lifting and sliding left and right. The suction nozzle is opposite to the positions of the plurality of screws and the cross bit.

[0007] Further, the driving assembly includes a base, a horizontal rotation motor is installed at the top of the base, a swing arm motor is installed at the output end of the horizontal rotation motor, and a vertical rotation motor is installed at the output end of the swing arm motor.

[0008] Further, an installation seat is installed at the output end of the vertical rotation motor, and a first mounting plate and a second mounting plate are installed on one side of the installation seat and distributed in parallel up and down.

[0009] Further, the servo motor is installed at the top of the first mounting plate. A single diaphragm coupling installed at the output end of the servo motor is arranged at the bottom of the first mounting plate. A dynamic torque sensor is installed at one end of the single diaphragm coupling away from the servo motor, and a slip ring is installed at one end of the dynamic torque sensor away from the single diaphragm coupling.

[0010] Further, the slip ring is fixedly inserted through the second mounting plate, and a self-locking chuck is installed at the output end of the slip ring.

[0011] Further, the screw clamping assembly further includes a first lead screw module installed on the back of the installation seat. The output end of the first lead screw module is installed with a plurality of alignment cylinders, and each of the screw clamping mechanisms is installed at the output end of the corresponding alignment cylinder.

[0012] Further, the screw feeding and discharging assembly further includes a workbench, a second lead screw module and a screw feeding tooling are installed on the workbench. The output end of the second lead screw module is installed with a slide cylinder, and a plurality of suction nozzles are installed at the output end of the slide cylinder.

[0013] The technical solution provided by the present invention has the following beneficial effects compared with the known prior art: 1. Meanwhile, the feeder in the present invention can receive and distribute screws of various sizes. The tightening gun, in cooperation with the robot, can achieve automatic material taking, automatic material placing. The tightening gun is equipped with a torque sensor to timely feedback the tightening state of the screws, feedback the tightening torque value, and exclude and feedback some defective screws.

[0014] 2. Through the cooperation of various components, the present invention can be applied to the feeding and tightening work of screws of various sizes, with good compatibility and high practicability. It can complete the assembly and tightening of various screws with one device, reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a schematic structural diagram of the overall first perspective of the present invention; Figure 2 It is a schematic structural diagram of the overall second perspective of the present invention; Figure 3 It is a schematic installation structure diagram of the tightening gun power assembly and the screw clamping assembly of the present invention; Figure 4 It is a schematic structural diagram of the screw feeding and discharging assembly of the present invention.

[0017] The reference numerals in the drawings respectively represent: 1. Driving assembly; 2. Tightening gun power assembly; 21. Servo motor; 22. Single diaphragm coupling; 23. Dynamic torque sensor; 24. Electric slip ring; 25. Self-locking chuck; 26. Cross bit; 3. Screw clamping assembly; 31. Screw clamping mechanism; 32. First lead screw module; 33. Alignment cylinder; 4. Screw feeding and discharging assembly; 41. Slide cylinder; 42. Suction nozzle; 43. Second lead screw module; 44. Screw discharging tooling. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0019] The present invention will be further described below in conjunction with embodiments. Embodiment 1

[0020] Referring to Figures 1-4 , which is the first embodiment of the present invention, a tightening mechanism adapted to different specifications of screws, includes a driving assembly 1 and a tightening gun power assembly 2 installed at the output end of the driving assembly 1. The tightening gun power assembly 2 includes a servo motor 21 installed at the output end of the driving assembly 1, and also includes a self-locking chuck 25 installed at the output end of the servo motor 21. A cross bit 26 is detachably installed in the self-locking chuck 25. The self-locking chuck 25 generally consists of parts such as a drill body, a nut, clamping jaws, a front sleeve, a rear sleeve, a nut sleeve, and rolling elements. The clamping jaws are installed in the equally divided inclined holes of the drill body, and the clamping and loosening actions are realized through the threaded transmission between the nut and the clamping jaws. The self-locking function of the self-locking chuck mainly depends on the elastic force generated by a spring (such as a disc spring). When the chuck is in the clamped state, the spring is compressed and stores energy, and at the same time generates friction to fix the cross bit 26. When an external force attempts to loosen the chuck, the elastic force of the spring will resist this movement, thus achieving the self-locking effect to clamp cross bits 26 with different diameters; The screw clamping assembly 3 includes a plurality of screw clamping mechanisms 31 that can move horizontally back and forth below the cross bit 26. Each of the several screw clamping mechanisms 31 includes guide columns that are symmetrically distributed in pairs and are opposite to the position of the cross bit 26. An O-ring is sleeved outside the two symmetric guide columns, and circumferential movement is realized through the guide columns on the left and right, and automatic clamping is carried out by adding an O-ring outside. When the screw enters the feeding position, the screw is automatically clamped. The screw feeding and discharging assembly 4 includes a screw feeding tooling 44 arranged below the screw clamping mechanism 31. A number of screws are detachably arranged on the screw feeding tooling 44. The screw feeding and discharging assembly 4 also includes a suction nozzle 42 that can be lifted and slide left and right and is arranged above the screw feeding tooling 44; The screw feeding tooling 44 is a special tooling device for the placement, positioning, and transportation of fasteners such as screws. It can accurately transport fasteners such as screws to the assembly station according to the predetermined position and sequence, thereby simplifying the assembly process and improving the assembly efficiency. At the same time, the feeding tooling can also ensure the stability and accuracy of the screws during transportation, avoiding damage or loss of the screws.

[0021] The suction nozzle 42 is a component used to suck materials in an air suction pneumatic conveying device. Its working principle is based on the fluid mechanics principle when air flows. When the air in the suction nozzle 42 is pumped away, a low-pressure area is formed inside the suction nozzle. At this time, the surrounding air will move from the high-pressure area to the low-pressure area, generating a pressure difference. This pressure difference is the reason for the suction force generated by the suction nozzle 42. The suction nozzle 42 is opposite to the positions of a number of screws and the cross bit 26. Embodiment 2

[0022] Referring to Figures 1-4 , which is the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the driving assembly 1 includes a base, on the top of which a horizontal rotation motor is installed. The output end of the horizontal rotation motor is installed with a rocker arm motor, and the output end of the rocker arm motor is installed with a vertical rotation motor. The output end of the vertical rotation motor is installed with a mounting seat, and on one side of the mounting seat, a first mounting plate and a second mounting plate are arranged in parallel up and down. The servo motor 21 is installed on the top of the first mounting plate, and at the bottom of the first mounting plate, a single diaphragm coupling 22 installed at the output end of the servo motor 21 is provided; The single diaphragm coupling 22 is composed of two half couplings and a metal diaphragm. The two half couplings are connected to the diaphragm by bolts to form a whole. The metal diaphragm is usually made of high-strength stainless steel material and has good elasticity and toughness. When there is a deviation between the driving shaft and the driven shaft, the diaphragm will undergo elastic deformation, thereby compensating for axial, radial and angular deviations. At the same time, the elastic deformation of the diaphragm can also absorb vibration and shock, reducing the noise and vibration of the transmission system. At the end of the single diaphragm coupling 22 far from the servo motor 21, a dynamic torque sensor 23 is installed; The dynamic torque sensor 23 is a sensor that can measure and output torque signals in real time. Its working principle is based on principles such as electromagnetic induction or resistance strain. When torque acts on the sensor, it will cause a small deformation of the internal structure of the sensor or a change in the magnetic resistance in the magnetic circuit, thereby changing the amplitude and phase of the induced electromotive force or the resistance value of the strain gauge. By measuring and processing these changes, the magnitude and direction of the torque can be accurately calculated. At the end of the dynamic torque sensor 23 far from the single diaphragm coupling 22, a slip ring 24 is installed. The slip ring 24 is fixedly inserted through the second mounting plate, and at the output end of the slip ring 24, a self-locking chuck 25 is installed; The slip ring 24 mainly consists of two major parts: a rotating part and a stationary part. The rotating part is connected to the rotating structure of the device and rotates with it, called the "rotor"; the stationary part is connected to the energy of the fixed structure of the device, called the "stator". The slip ring 24 transmits energy and data between the two components. It is usually composed of a set of metal rings and corresponding brush wires. During operation, the brush part remains stationary and the metal part rotates. The leads of the brush and the conductive ring are in contact inside and are electrically connected to the devices on both sides of the slip ring. In this way, it is equivalent to one end of the wire being fixed to the stator of the slip ring and the other end of the wire rotating with the rotor of the slip ring, thus avoiding winding; The screw clamping assembly 3 also includes a first screw rod module 32 installed on the back of the mounting seat, and a plurality of alignment cylinders 33 are installed at the output end of the first screw rod module 32, and a plurality of screw clamping mechanisms 31 are respectively installed on the output ends of the corresponding alignment cylinders 33. The screw feeding and discharging assembly 4 also includes a workbench, and a second screw rod module 43 and a screw feeding tool 44 are installed on the workbench. A slide cylinder 41 is installed at the output end of the second screw rod module 43, and a plurality of suction nozzles 42 are installed at the output end of the slide cylinder 41; The two screw modules 43 are mainly composed of a ball screw, a U-shaped structural body, a motor and other related accessories. Among them, the ball screw is the core component of the module. It realizes the conversion from rotational motion to linear motion by cooperating with the nut. The U-shaped structural body provides stable support for the module, and the motor provides a power source.

[0023] The remaining structures are the same as those of Example 1.

[0024] Working principle of the present invention: In the first step, the second screw module 43 is started to drive the slide cylinder 41 and the suction nozzle 42 to move linearly until the suction nozzles 42 are opposite to the screw feeding fixture 44, and the screws placed on the screw feeding fixture 44 are sucked by the suction nozzles 42, and then the suction nozzles 42 and the screws are driven to rise by the slide cylinder 41 until they are opposite to the cross screwdriver bit 26; The second step is to start the servo motor 21, drive the single diaphragm coupling 22 to rotate, monitor the torque in real time through the dynamic torque sensor 23, and drive the electric slip ring 24 to rotate, thereby driving the self-locking chuck 25 to rotate, thereby driving the cross bit 26 to rotate. At the same time, adjust the alignment cylinder 33 through the first screw module 32, and drive the screw clamping mechanism 31 to descend in height through the alignment cylinder 33 until it is opposite to the position of the suction nozzle 42, and realize circular movement through the guide column on the left and right, and automatically clamp the O-ring on the outside. When the screw enters the feeding position, it is automatically clamped, and the screw avoids the cylinder. When the screw needs to be tightened, the working position cylinder is pressed down for alignment. The other three groups of cylinders are in the initial position of the cylinder to avoid the body of the workpiece to be assembled. The third step is to start the horizontal rotation motor, which in turn drives the rocker motor to rotate in the horizontal direction, then start the rocker motor to drive the vertical rotation motor to rotate in the vertical direction, and finally start the vertical rotation motor to drive the mounting base and the tightening gun power assembly to rotate, thereby facilitating the adjustment of the position of the cross bit 26 and the screw, and tighten the screw to the screw hole of the workpiece by rotating the cross bit 26.

[0025] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tightening mechanism adapted to screws of different specifications, comprising a drive assembly (1) and a tightening gun power assembly (2) mounted at the output end of the drive assembly (1), characterized in that: Also includes: A tightening gun power assembly (2) comprises a servo motor (21) mounted at the output end of the drive assembly (1), and also comprises a self-locking chuck (25) mounted at the output end of the servo motor (21), wherein a cross head (26) is detachably mounted in the self-locking chuck (25); A screw clamping assembly (3) comprising a plurality of screw clamping mechanisms (31) arranged below the cross screwdriver bit (26) and capable of laterally reciprocating movement; A plurality of screw clamping mechanisms (31), each comprising guide pillars symmetrically distributed in pairs and opposite to the cross screwdriver bit (26), wherein an O-ring is commonly sleeved on the outer sides of the two symmetrical guide pillars; The screw feeding and discharging assembly (4) comprises a screw discharging tool (44) arranged below the screw clamping mechanism (31), a plurality of screws being detachably arranged on the screw discharging tool (44), and a suction nozzle (42) arranged above the screw discharging tool (44) and capable of being raised and lowered and slid left and right, the suction nozzle (42) being positioned opposite to the plurality of screws and the cross screwdriver bit (26).

2. A tightening mechanism adapted to screws of different specifications according to claim 1, characterized in that: The driving assembly (1) comprises a base, a horizontal rotating motor is mounted on the top of the base, an output end of the horizontal rotating motor is mounted on a rocker motor, and a vertical rotating motor is mounted on the output end of the rocker motor.

3. A tightening mechanism adapted to screws of different specifications according to claim 1, characterized in that: The output end of the vertical rotating motor is equipped with a mounting seat, and one side of the mounting seat is equipped with a first mounting plate and a second mounting plate which are parallelly distributed up and down.

4. A tightening mechanism adapted to screws of different specifications according to claim 3, characterized in that: The servo motor (21) is mounted on the top of a first mounting plate, and a single diaphragm coupling (22) mounted on the output end of the servo motor (21) is provided at the bottom of the first mounting plate; a dynamic torque sensor (23) is mounted on one end of the single diaphragm coupling (22) away from the servo motor (21); and an electric slip ring (24) is mounted on one end of the dynamic torque sensor (23) away from the single diaphragm coupling (22).

5. A tightening mechanism adapted to screws of different specifications according to claim 4, characterized in that: The electric slip ring (24) is inserted through and fixedly plugged into the second mounting plate, and a self-locking clamp (25) is installed at the output end of the electric slip ring (24).

6. A tightening mechanism adapted to screws of different specifications according to claim 1, characterized in that: The screw clamping assembly (3) further comprises a first screw module (32) mounted on the back of the mounting seat, a plurality of alignment cylinders (33) being mounted on the output end of the first screw module (32), and a plurality of the screw clamping mechanisms (31) being mounted on the output ends of corresponding alignment cylinders (33).

7. A tightening mechanism adapted to screws of different specifications according to claim 1, characterized in that: The screw feeding and discharging assembly (4) further comprises a workbench, on which a second screw module (43) and a screw discharging tool (44) are mounted, a slide cylinder (41) is mounted at the output end of the second screw module (43), and a plurality of suction nozzles (42) are mounted at the output end of the slide cylinder (41).

Images