A screw driving device, a screw automatic mounting apparatus, and a screw floating detection method

Abstract

The application discloses a screw driving device, which comprises a mounting base plate, a guide rail extending in the vertical direction is fixed on the front side of the mounting base plate, a supporting platform is arranged on the lower part of the mounting base plate, a screw pipe extending vertically downward is arranged on the front part of the supporting platform, the screw pipe is provided with a central through hole, a supporting assembly and a correcting assembly are arranged at the lower end of the screw pipe, the supporting assembly can move radially along the screw pipe and is used for supporting the screw nut of the screw, the correcting assembly is used for making the center line of the screw coincide with the center line of the screw pipe, an electric screwdriver mechanism is slidably arranged on the guide rail through a lifting mechanism, the electric screwdriver mechanism comprises a first motor and a tool head driven to rotate by the first motor, under the action of the lifting mechanism, the tool head can be inserted downward to the bottom of the central through hole and is used for rotating the screw at the lower end of the screw pipe. The screw driving device has the advantages that the problems of screw skewing, screw moving and falling off and screw deviation can be effectively avoided during the screw driving process.

Description

Technical Field

[0001] This invention belongs to the technical field of automatic screw installation tools, specifically relating to a screw driving device, an automatic screw installation equipment, and a screw floating height detection method. Background Technology

[0002] An automatic screw-driving device is a small machine that automates screw fastening. Its operating structure can generally be divided into two parts: a screw receiving mechanism and an electric screwdriver mechanism. The screw receiving mechanism is responsible for screening and providing screws, while the electric screwdriver mechanism is responsible for picking up and fastening the screws. The emergence of automatic screw-driving devices saves labor costs and improves production and assembly efficiency.

[0003] In traditional technologies, automatic screw-driving devices primarily use suction nozzles or clamping nozzles to remove screws. These two methods suffer from problems such as screw misalignment, screw slippage and drop, and misaligned screw driving. Specifically:

[0004] 1. The suction nozzle type picks up one screw at a time from the screw feeder. When the screw is removed from the screw feeder, it may scrape against the surface, causing it to become misaligned. Furthermore, the nozzle's internal contour is designed to mimic the shape of the screw head, requiring a relatively high degree of screw consistency. If the screw head shape deviates, it will also cause misalignment. This type of nozzle typically works better with flat-head screws than with round-head screws because both the nozzle's contour surface and the screw head's contour surface are curved. These two curved surfaces cannot restrict the screw's freedom of movement, ultimately leading to misalignment. In addition, during the high-speed movement of the nozzle, the screw can easily break free from the vacuum suction force, causing it to fall out.

[0005] 2. The screw is supplied by an air-blowing screw feeder. The screw is held in place by spring force. When screwing, the screw gun pushes the screw forward directly against it, and the screw pushes the screw open. In this method, the force on the two sides of the screw is unbalanced when the screw is pushed open. It is possible that one side of the screw opens at a larger angle and the other side opens at a smaller angle, which will cause the screw to be crooked.

[0006] Undoubtedly, problems such as misaligned screws, loose or fallen screws, and misaligned screws will affect the screw assembly accuracy, reduce product quality, and even cause the product to be scrapped. Summary of the Invention

[0007] In view of the above situation, the present invention provides a screw-driving device that can effectively avoid problems such as screw misalignment, screw falling off, and screw misalignment.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A screw-driving device, the key feature of which is that it includes:

[0010] The mounting base plate has a guide rail that extends vertically fixed on its front side;

[0011] A support platform is installed on the lower part of the mounting base plate. A screw channel extending vertically downward is installed on the front part of the support platform. The screw channel has a central through hole. A support assembly and a correction assembly are provided at the lower end of the screw channel. The support assembly can move radially along the screw channel to support the screw nut. The correction assembly is used to make the center line of the screw coincide with the center line of the screw channel.

[0012] The electric screwdriver mechanism is slidably mounted on the guide rail via a lifting mechanism. The electric screwdriver mechanism includes a first motor and a tool head driven to rotate by the first motor. Under the action of the lifting mechanism, the tool head can be inserted downward to the bottom of the central through hole and turn the screw at the lower end of the screw pipe.

[0013] With the above structure, when the screw is delivered to the end of the screw channel, the support assembly can stably support the screw nut to prevent the screw from falling, and the alignment assembly can align the screw, keeping it vertically on the center line of the screw channel to avoid screw skew. Then, under the action of the lifting mechanism, the tool head can be inserted downwards into the nut at the bottom of the central through hole, and the first motor drives the tool head to turn the screw, realizing the screw driving operation. During the screw driving process of the electric screwdriver mechanism, the screw is always kept vertically on the center line of the screw channel, which can prevent the screw from being driven off-center.

[0014] Preferably, the lifting mechanism includes a second motor fixed to the top of the mounting base, a lead screw driven by the second motor, and a seat assembly threaded onto the lead screw. The seat assembly is slidably connected to the guide rail via a first slider, and the electric screwdriver mechanism is fixedly mounted on the seat assembly.

[0015] Preferably, the seat assembly is a split structure, which includes a front support plate and a rear support plate. The front support plate is fixedly connected to the front side of the first slider, and the rear support plate is threaded onto the lead screw. A support lug is fixedly provided on the side of the front support plate, and a preload spring abuts against the support lug and the rear support plate.

[0016] Preferably, the support assembly includes two spring plates symmetrically arranged on both radial sides of the screw pipe, and the lower ends of the two spring plates are provided with stop posts extending into the screw pipe.

[0017] Preferably, each spring sheet has two sets of four sets of retaining posts at its lower end, and the ends of each retaining post are spherical.

[0018] Preferably, the correction assembly includes a finger cylinder and two sets of grippers that are driven to open and close by the finger cylinder, and the lower ends of the two sets of grippers have arc-shaped grooves adapted to the outer diameter of the screw.

[0019] Preferably, the screw pipe, support assembly, and correction assembly are all rotatably mounted on a support platform, and the support platform is provided with a rotating mechanism for driving the screw pipe, support assembly, and correction assembly to rotate as a whole.

[0020] Preferably, the support platform has a transition block at its rear end, which is slidably mounted on the lower part of the guide rail via a second slider. The lower end of the mounting base plate is provided with a limiting part, and a stress relief spring is provided between the transition block and the mounting base plate. The stress relief spring causes the support platform to press downward against the limiting part.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] Using the screw-driving device provided by this invention, when the screw is delivered to the end of the screw channel, the support assembly can stably support the screw nut to prevent the screw from falling off, and the correction assembly can correct the screw, keeping it vertically on the center line of the screw channel to avoid screw skew. Then, under the action of the lifting mechanism, the tool head can be inserted downwards into the nut at the bottom of the central through hole, and the first motor drives the tool head to turn the screw, realizing the screw-driving operation. During the screw-driving process of the electric screwdriver mechanism, the screw can always be kept vertically on the center line of the screw channel, avoiding screw deviation. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the screw-driving device A;

[0024] Figure 2 Front view of an automatic screw mounting device;

[0025] Figure 3 A 3D reference diagram of an automatic screw installation device;

[0026] Figure 4 Another schematic diagram of the screw-driving device A;

[0027] Figure 5 To show the structural schematic diagram of the corresponding components on support platform 2;

[0028] Figure 6 To show another structural schematic diagram (bottom view) of the corresponding components on support platform 2;

[0029] Figure 7 This is a cross-sectional view of the screw-driving device A;

[0030] Figure 8 for Figure 7A magnified view of part H in the middle;

[0031] Figure 9 To show a cross-sectional view of the screw-driving device A when the tool head 1a has not entered the screw conduit 9;

[0032] Figure 10 To show the cross-sectional view A of the screw-driving device with screw introduction channel 6d;

[0033] Figure 11 A cross-sectional view of the screw-driving device A when the tool head 1a enters the screw pipe 9;

[0034] Figure 12 To show a cross-sectional view of the tool head 1a inserted downwards onto the screw nut e;

[0035] Figure 13 for Figure 9 A magnified view of part G in the middle;

[0036] Figure 14 This is a schematic diagram of the structure of the buoyancy detection connector 18. Detailed Implementation

[0037] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0038] like Figure 2 As shown, an automatic screw installation device includes a machine frame B, a clamping platform C, and a screw-driving device A mounted on the machine frame B. The clamping platform C is located at the bottom of the machine frame B and is used to fix the product D to be assembled. Figure 3 As can be seen, the equipment frame B is equipped with an X-axis linear motion module 11, a Y-axis linear motion module 12, and a Z-axis linear motion module 13, which are used to control the screw-driving device A to move in the X, Y, and Z directions of the equipment, respectively. In addition, a CCD camera 14 is installed on the top of the equipment frame B to identify the position of the screw holes of the product D to be assembled.

[0039] When using an automatic screw installation device to drive screws into product D, first move the screw driving device A above the screw hole to be assembled, then use CCD camera 14 to take a picture to identify whether the screw driving device A is aligned with the screw hole to be assembled. If the CCD camera 14 takes a picture to identify that it is aligned, then the screw driving device A will drive screws into the screw hole below.

[0040] For example Figure 1 As shown, a screw-driving device A includes a mounting base 7, an electric screwdriver mechanism 1, and a support platform 2. The mounting base 7 has a vertically extending guide rail 7a fixed to its front side. The electric screwdriver mechanism 1 is slidably mounted on the guide rail 7a via a lifting mechanism 8. The support platform 2 is mounted on the lower part of the mounting base 7. (Further details omitted as they are not provided in the original text.) Figure 5 and 11 As shown, a vertically downward extending screw channel 9 is installed at the front of the support platform 2. The screw channel 9 has a central through hole 9b. A support assembly 3 and a correction assembly 4 are provided at the lower end of the screw channel 9. The support assembly 3 can move radially along the screw channel 9 to support the nut of the screw e. The correction assembly 4 is used to make the center line of the screw e coincide with the center line of the screw channel 9. The electric screwdriver mechanism 1 includes a first motor 1b and a tool head 1a. The first motor 1b can drive the tool head 1a to rotate. Under the action of the lifting mechanism 8, please refer to... Figure 12 The tool head 1a can be inserted downwards to the bottom of the central through hole 9b and the screw e at the lower end of the screw pipe 9 can be turned.

[0041] Based on the above structural design, the working principle of the screw-driving device A is as follows: When the screw e is delivered to the end of the screw channel 9, the support assembly 3 can stably support the nut of the screw e, preventing the screw e from falling off. The correction assembly 4 can correct the screw e, keeping it vertically on the center line of the screw channel 9, preventing the screw e from being skewed. Then, under the action of the lifting mechanism 8, the tool head 1a can be inserted downwards into the nut of the screw e, and the first motor 1b can drive the tool head 1a to turn the screw e, locking the screw e in the screw hole of the product D. During the screw-driving process, the screw e is always vertically kept on the center line of the screw channel 9, effectively preventing the screw e from being driven off-center.

[0042] For further details, please refer to Figure 4 The lifting mechanism 8 includes a second motor 8a fixed to the top of the mounting base 7, a lead screw 8b driven to rotate by the second motor 8a, and a seat assembly 8c threadedly connected to the lead screw 8b. The seat assembly 8c is slidably connected to the guide rail 7a via a first slider 8d, and the electric screwdriver mechanism 1 is fixedly mounted on the seat assembly 8c. Activating the second motor 8a drives the lead screw 8b to rotate, thereby causing the seat assembly 8c to move up and down on the lead screw 8b, thus controlling the electric screwdriver mechanism 1 to slide up and down on the guide rail 7a.

[0043] Furthermore, such as Figure 4As shown, the seat assembly 8c is a split structure, comprising a front support plate 8c1 and a rear support plate 8c2. The front support plate 8c1 is fixedly connected to the front side of the first slider 8d, and the first motor 1b is fixedly connected to the front support plate 8c1. The rear support plate 8c2 is threaded onto the lead screw 8b. A support lug 8c3 is fixedly provided on the side of the front support plate 8c1, and a preload spring 10 abuts against the support lug 8c3 and the rear support plate 8c2. Furthermore, a second guide rod g extending vertically downward is fixedly provided on the rear support plate 8c2. The second guide rod g passes downward through the lower end of the support lug 8c3 and is slidably connected to the support lug 8c3. The preload spring 10 is fitted onto the second guide rod g, with its upper end abutting against the lower side of the rear support plate 8c2 and its lower end abutting against the support lug 8c3.

[0044] During the screw-driving process of the screw-driving device A, the second motor 8a drives the lead screw 8b to rotate, thereby causing the tool head 1a to insert downwards into the nut of the screw e. When the screw e enters the screw hole of the product D, the tool head 1a can no longer descend. At this time, the rotation of the lead screw 8b causes the rear support plate 8c2 to move downwards a certain distance. The preload spring 10 between the rear support plate 8c2 and the lug component 8c3 is compressed. The compressed preload spring 10 provides a downward preload force for the tool head 1a. Driven by the first motor 1b, the tool head 1a can turn the screw e downwards, so that the screw e is locked in the screw hole of the product D.

[0045] Please refer to Figure 5 and 6 The correction component 4 includes a finger cylinder 4b and two sets of grippers 4a. The finger cylinder 4b can drive the two sets of grippers 4a to open and close. The two sets of grippers 4a are symmetrically arranged on both sides of the screw channel 9 in the radial direction. The upper end of the grippers 4a is connected to the finger cylinder 4b, and the lower end of each gripper has an arc-shaped groove 4a1 adapted to the outer diameter of the screw e. When the screw e is delivered to the lower end of the screw channel 9, the two sets of grippers 4a close. The arc-shaped grooves 4a1 at the lower end of the two sets of grippers 4a can just clamp the screw e, so that the center line of the screw e is always kept on the center line of the screw channel 9, avoiding the screw e from being skewed.

[0046] Revisit Figure 6 Each set of arc-shaped grooves 4a1 has guide slopes 4a2 at both ends. When screw e is misaligned to a certain extent, the guide slopes 4a2 at both ends of the arc-shaped grooves 4a1 can guide screw e into the arc-shaped grooves 4a1, completing the correction of screw e. If the ends of the arc-shaped grooves 4a1 are straight, when screw e is misaligned, the end of the arc-shaped grooves 4a1 may easily push screw e out of the arc-shaped grooves 4a1, or the end of the arc-shaped grooves 4a1 may directly get stuck on the threads of screw e, causing screw e to be misaligned. In the subsequent screw-driving work, the screw e may be driven off-center, which seriously affects the assembly quality of the product.

[0047] like Figure 5 and6 The support assembly 3 includes two spring plates 3b symmetrically arranged on both radial sides of the screw channel 9. Each spring plate 3b has a stop post 3a extending into the screw channel 9 at its lower end. In this embodiment, there are two sets of stop posts 3a at the lower end of each spring plate 3b, and the four sets of stop posts 3a are arranged in a rectangular pattern. This design better supports the lower end of the screw nut, making the screw nut more stably supported on the four stop posts 3a. Furthermore, [further details omitted]. Figure 6 and 7 Each stop post 3a has a spherical structure 3a1 at its end. When the electric screwdriver mechanism 1 starts to drive the screw e downward, it helps to guide each stop post 3a to move radially outward along the screw channel 9. During this process, the lower part of the spring plate 3b bends outward, so that the nut of the screw e can pass downward over the stop post 3a.

[0048] Revisit Figure 6 The lower end of the screw pipe 9 is provided with a relief groove 9a corresponding to four sets of stop posts 3a. Each set of stop posts 3a passes through the corresponding relief groove 9a and extends into the interior of the screw pipe 9. In addition, two spring plates 3b and two sets of clamps 4a are distributed around the screw pipe 9 and do not interfere with each other.

[0049] Please refer to Figure 5 The support platform 2 is equipped with a rotating mechanism 5, which can drive the screw channel 9, support assembly 3, and correction assembly 4 to rotate as a whole. When the electric screwdriver mechanism 1 is performing the screw-driving operation, the finger cylinder 4b drives the two sets of grippers 4a to open. At this time, if there are obstacles around the screw holes of the product below, the grippers 4a may interfere when they open. Therefore, the rotating mechanism 5 needs to drive the screw channel 9, support assembly 3, and correction assembly 4 to rotate as a whole at a certain angle until there are no obstacles in the direction in which the grippers 4a open. This avoids damage to the product or device caused by the grippers 4a being forcibly opened, and further improves the scope of use and lifespan of the device.

[0050] Combined Figure 5 and Figure 13 The rotating mechanism 5 includes a servo motor 5a fixed on the support platform 2, a drive gear 5b fixed on the output shaft a of the servo motor 5a, and a driven gear 5c meshing with the drive gear 5b. A washer 5d is fixedly connected to the lower side of the driven gear 5c, and a rotating fixed seat 5e is fixedly connected to the lower side of the washer 5d. The screw pipe 9, the support assembly 3, and the correction assembly 4 are all fixedly connected to the rotating fixed seat 5e. The working principle of the rotating mechanism 5 is as follows: the servo motor 5a drives the drive gear 5b to rotate, the drive gear 5b drives the driven gear 5c to rotate, thereby driving the rotating fixed seat 5e below to rotate. Using the servo motor 5a to drive the rotation has the advantages of small size and high torque, which can minimize the installation space of the device and simplify the mechanism design.

[0051] Furthermore, such as Figure 6 As shown, the support platform 2 is provided with a gear cover 2c on the outside, which can cover the driving gear 5b and the driven gear 5c, protect the driving gear 5b and the driven gear 5c, and improve the aesthetics of the device.

[0052] Furthermore, such as Figure 5 and 13 As shown, a connecting seat 6 is provided on the support platform 2 above the driven gear 5c. The connecting seat 6 includes a connecting plate 6a and a connecting shaft 6b. The connecting plate 6a is rotatably mounted on the support platform 2 via a bearing h. The connecting shaft 6b passes downward through the middle of the washer 5d, and its lower end is fixedly connected to the rotating fixed seat 5e by a screw. The upper part of the screw tube 9 passes upward through the rotating fixed seat 5e and is embedded in the connecting shaft 6b. The upper end of each spring plate 3b is embedded in the rotating fixed seat 5e. Simultaneously, combined with... Figure 8 It can be seen that the finger cylinder 4b is fixedly connected to the rotating fixed seat 5e. With this design, when the servo motor 5a drives the drive gear 5b to rotate, the rotating fixed seat 5e can drive the screw pipe 9, the support assembly 3 and the correction assembly 4 to rotate.

[0053] Revisit Figure 10 The connecting seat 6 has a tool channel 6c extending through its height and a screw introduction channel 6d extending obliquely upward from the side of the tool channel 6c. The lower end of the tool channel 6c abuts against the screw channel 9. The center lines of the tool channel 6c, the screw channel 9, and the driven gear 5c coincide. (Further details omitted) Figure 4 It can be seen that the upper end of the screw introduction channel 6d is connected to a plastic hose 6d1, and the other end of the plastic hose 6d1 is connected to the screw feeder. The screw feeder can transport the screw e through the plastic hose 6d1 to the screw pipe 9.

[0054] In this embodiment, the screw-driving device A operates as follows:

[0055] The screw feeder delivers screw e to the plastic hose 6d1. Screw e enters the tool channel 6c through the screw introduction channel 6d and finally falls to the lower end of the screw pipe 9. Figure 7 and 9 The lower end of the nut of screw e is supported on four sets of stop pins 3a. Simultaneously, the finger cylinder 4b drives the two sets of grippers 4a to close, ensuring the lower ends of the grippers 4a lock and correct screw e, keeping its centerline aligned with the centerline of the screw channel 9, thus preventing screw e from tilting. Subsequently, the screw-driving device A, under the control of the X-axis linear movement module 11, Y-axis linear movement module 12, and Z-axis linear movement module 13, moves above product D, positioning screw e directly above the screw hole of product D, and then... Figure 9 , 1011 and 12, the lifting mechanism 8 drives the electric screwdriver bit 11 through the tool channel 6c into the screw channel 9, so that the lower end of the electric screwdriver bit 11 presses against the cross head of the screw e's nut. Then, the Z-axis linear module 13 descends, driving the screw-driving device A to descend and insert the conical head of the screw e into the screw hole of the product D. Then, the finger cylinder 4b drives the two sets of grippers 4a to open. Under the action of the pre-tension spring 10, the electric screwdriver mechanism 1 can drive the electric screwdriver bit 11 to turn the screw e downward. The nut of the screw e can open the two sets of spring plates 3b and pass downward over the stop post 3a, thereby locking the screw e in the corresponding screw hole. During the conveying and locking process of the screw e, the screw e is always kept vertically on the center line of the screw channel 9, ensuring that the screw e can be accurately locked in the corresponding screw hole, and also preventing the screw e from falling off during movement.

[0056] Please refer to Figure 1 A transition block 2a is fixedly connected to the rear end of the support platform 2. The transition block 2a is slidably mounted on the lower part of the guide rail 7a via a second slider 2b. A limiting part 7b is provided at the lower end of the mounting base plate 7. A stress relief spring f is provided between the transition block 2a and the mounting base plate 7. The stress relief spring f causes the support platform 2 to press downward against the limiting part 7b. When the support platform 2 is subjected to an upward pushing force, the stress relief spring f can be deformed to relieve the force.

[0057] Based on the above structural design, when the screw-driving device A moves towards the screw hole of product D, if the height of product D itself deviates significantly, or if the descent distance of the screw-driving device A is not accurately adjusted, the components at the lower end of the screw-driving device A (such as the screw pipe 9, support assembly 3, and correction assembly 4) are prone to colliding with product D or the plane below it. When the screw-driving device A does not collide, the unloading spring f keeps the lower part of the support platform 2 continuously pressed against the limiting part 7b. When the screw-driving device A collides downwards, the unloading spring f is forced to contract under pressure, and the support platform 2 can slide upwards along the height direction of the mounting base 7 to avoid direct collision and damage between the screw-driving device A and the product or the plane. After a collision, the screw-driving device A moves upwards as a whole. After the screw-driving device A leaves the collision position, the downward force of the unloading spring f causes the support platform 2 to return to the limiting part 7b.

[0058] In this embodiment, when the screw-driving device A does not collide, the second slider 2b rests downward against the limiting part 7b. (See also...) Figure 8 The limiting part 7b is a limiting block fixedly mounted on the lower end of the mounting base plate 7. The front end of the limiting block protrudes forward from the guide rail 2a, allowing the second slider 2b to abut downward against the limiting part 7b. Combined with... Figure 1, a limiting plate 7c is fixedly assembled at a position above the adapter block 2a on the mounting substrate 7. A guide rod 17 extending vertically upward is fixedly installed at the upper end of the adapter block 2a. One end of the guide rod 17 far from the adapter block 2a is slidably connected to the limiting plate 7c. In this embodiment, the force-relieving spring f is a compression spring, which is sleeved on the guide rod 17. The lower end of the compression spring abuts against the upper side of the adapter block 2a, and the upper end abuts against the lower side of the limiting plate 7c.

[0059] With such a design, when the components at the lower end of the support platform 2 do not collide, the second slider 2b abuts against the limiting portion 7b. When the components at the lower end of the support platform 2 collide downward, the compression spring can be compressed. At this time, please refer to Figure 8 , the second slider 2b moves upward away from the surface of the limiting portion 7b, and the support platform 2 moves upward along the height direction of the mounting substrate 7, avoiding the device from being damaged. In this embodiment, the maximum upward contraction amount of the support platform 2 is 10 mm. By adopting the design of abutting the second slider 2b against the limiting portion 7b, it can avoid causing serious damage to the support platform 2 when the rebounding force of the second slider 2b is too large. If the design of directly abutting the support platform 2 against the limiting portion 7b is adopted, when the components at the lower end of the support platform 2 collide with a large force and move upward, the force for the support platform 2 to reset downward will also be greater. Therefore, when the support platform 2 resets to the upper side of the limiting portion 7b, it will also cause certain damage, affecting the use performance of the device itself.

[0060] After the screw e is inserted into the product D, it is also necessary to test whether the screw e is tightened. There are mainly two traditional methods for detecting the floating height of screws. One is to judge whether the screw is tightened by measuring the position height of the screw after tightening through a sensor. If the current screw height detected by the sensor is within the set range, it is judged as qualified. If the current screw height detected by the sensor exceeds the range, it is judged that the screw is not tightened. This method cannot accurately judge whether the screw is tightened for products with poor height dimension consistency, large tolerances, or products that will produce concave deformation when stressed.

[0061] Another method is to judge whether the screw is tightened by detecting the number of rotation circles of the electric screwdriver. This method generally uses an intelligent servo electric screwdriver to detect torque changes and the number of rotation circles of the electric screwdriver to judge whether the screw is tightened. When the screw starts to be inserted, the torque changes, and then the number of rotation circles of the electric screwdriver is detected. This method cannot be used for ordinary electric screwdriver mechanisms because ordinary electric screwdrivers cannot detect torque and the number of rotation circles. Another point is that although there are already patents on the tooth-insertion detection of intelligent electric screwdrivers, currently, almost all intelligent electric screwdrivers on the market do not support the tooth-insertion detection function and only simply judge whether the screw is tightened by the number of rotation circles. This method is not accurate. For example, one screw may start to be inserted into the product after rotating 30 degrees, and another screw may start to be inserted after rotating 300 degrees, which will cause deviations in the number of rotation circles. The greater the lead of the screw, the greater the floating height deviation generated by the same number of rotation circles.

[0062] Therefore, this embodiment also provides a method for detecting screw float, which can effectively determine whether screw e is tightened. Please refer to... Figure 1 A first sensor 15 is installed on the support platform 2, a second sensor 16 is installed on the electric screwdriver mechanism 1, and a float detection connector 18 is fixedly connected to the side of the adapter block 2a. Figure 14 As shown, the buoyancy detection connector 18 has a lower connecting section 18a, a support section 18b extending vertically upward from the rear end of the lower connecting section 18a, and a sensor scale 18c horizontally placed on top of the support section 18b.

[0063] The screw height detection method is as follows: While the tool head 1a screws the screw e into the screw hole of the product D, the support platform 2 remains stationary. The second sensor 16 descends with the electric screwdriver mechanism 1. At this time, the first sensor 15 can detect the height change value m of the product D at the screw hole position. The second sensor 16, by detecting the displacement from the second sensor 16 to the sensor scale 18c, can reflect the displacement n of the tool head 1a in the height direction. The difference between this displacement n and the height change value m is the screw-in depth of the screw e. Since the screw-in depth of the screw e is equal to the length of the threaded section of the screw e, and this length is fixed, when the difference between the displacement n and the height change value m equals the length of the threaded section, it can be confirmed that the screw e is tightened. If the height dimension of product D has poor consistency or large tolerance, or if the surface of product D is deformed by force, the height change value m of product D at the screw hole position will also change. Correspondingly, the electric screwdriver mechanism 1 drives the second sensor 16, and the required lowering height position will also change. The distance from the measured second sensor 16 to the sensor scale 18c will also change accordingly, that is, the displacement n will change. The displacement n and the height change value m are the same; they either increase or decrease simultaneously. Therefore, no matter how large the product height error is, or if the product surface is deformed by force, the difference between the displacement n and the height change m will always be the same. If the difference between the two increases, it can only mean that the screw is not tightened. Through this difference measurement method, misjudgment of the screw tightening result can be effectively avoided due to problems such as excessive product height error and product surface deformation caused by force.

[0064] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A screw-driving device (A), characterized in that, include: Mounting base plate (7), with a guide rail (7a) extending vertically fixed on its front side. A support platform (2) is installed on the lower part of the mounting base plate (7). A screw channel (9) extending vertically downward is installed on the front part of the support platform (2). The screw channel (9) has a central through hole (9b). A support assembly (3) and a correction assembly (4) are provided at the lower end of the screw channel (9). The support assembly (3) can move radially along the screw channel (9) to support the screw nut. The correction assembly (4) is used to make the center line of the screw coincide with the center line of the screw channel (9). And an electric screwdriver mechanism (1), which is slidably mounted on the guide rail (7a) via a lifting mechanism (8). The electric screwdriver mechanism (1) includes a first motor (1b) and a tool head (1a) driven to rotate by the first motor (1b). Under the action of the lifting mechanism (8), the tool head (1a) can be inserted downward to the bottom of the central through hole (9b) and rotate the screw at the lower end of the screw pipe (9). The support assembly (3) includes two spring plates (3b) symmetrically arranged on both radial sides of the screw pipe (9). The lower ends of the two spring plates (3b) are provided with stop posts (3a) that extend into the screw pipe (9). There are two sets of stop posts (3a) at the lower end of each spring plate (3b). The four sets of stop posts (3a) are rectangularly distributed, and the ends of each stop post (3a) are spherical structures (3a1). The correction assembly (4) includes a finger cylinder (4b) and two sets of grippers (4a) driven by the finger cylinder (4b) to open and close. The lower ends of the two sets of grippers (4a) have arc grooves (4a1) adapted to the outer diameter of the screw. The screw pipe (9), the support assembly (3) and the correction assembly (4) are all rotatably mounted on the support platform (2). The support platform (2) is provided with a rotating mechanism (5). The rotating mechanism (5) is used to drive the screw pipe (9), the support assembly (3) and the correction assembly (4) to rotate as a whole.

2. The screw-driving device according to claim 1, characterized in that: The lifting mechanism (8) includes a second motor (8a) fixed on the top of the mounting base plate (7), a lead screw (8b) driven to rotate by the second motor (8a), and a seat assembly (8c) threaded onto the lead screw (8b). The seat assembly (8c) is slidably connected to the guide rail (7a) via a first slider (8d). The electric screwdriver mechanism (1) is fixedly mounted on the seat assembly (8c).

3. The screw-driving device according to claim 2, characterized in that: The seat assembly (8c) is a split structure, which includes a front support plate (8c1) and a rear support plate (8c2). The front support plate (8c1) is fixedly connected to the front side of the first slider (8d), and the rear support plate (8c2) is threaded onto the lead screw (8b). A support lug (8c3) is fixedly provided on the side of the front support plate (8c1), and a preload spring (10) abuts between the support lug (8c3) and the rear support plate (8c2).

4. The screw-driving device according to claim 1, characterized in that: The support platform (2) has a transition block (2a) at its rear end. The transition block (2a) is slidably mounted on the lower part of the guide rail (7a) via a second slider (2b). The mounting base plate (7) has a limiting part (7b) at its lower end. A relief spring (f) is provided between the transition block (2a) and the mounting base plate (7). The relief spring (f) causes the support platform (2) to abut against the limiting part (7b) downwards.

5. An automatic screw installation device, comprising a machine frame (B), characterized in that: It also includes a screw-driving device (A) according to any one of claims 1 to 4, wherein the equipment frame (B) is provided with an X-direction linear movement module (11), a Y-direction linear movement module (12) and a Z-direction linear movement module (13), which are respectively used to control the screw-driving device (A) to move in the X, Y and Z directions of the equipment; A CCD camera (14) is mounted on the top of the equipment frame (B) for identifying the position of screw holes in the product to be assembled.

6. A screw height detection method based on the screw automatic installation equipment of claim 5, wherein a first sensor (15) is installed on the support platform (2), a second sensor (16) is installed on the electric screwdriver mechanism (1), and a product (D) is fixedly assembled on the clamping platform (C) of the screw automatic installation equipment. The method is as follows: during the process of the tool head (1a) screwing the screw into the screw hole of the product (D), the first sensor (15) detects the height change value of the product (D) at the screw hole position, and the second sensor (16) detects the displacement of the tool head (1a) in the height direction. The difference between the displacement and the height change value is the screwing depth of the screw.

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