Downforce control module of screw fastening robot, screw fastening robot, and method for controlling same

Abstract

A downforce control module of a screw fastening robot, a screw fastening robot, and a method for controlling same. The downforce control module (2) comprises a fixing member (21), a sliding member (22), a pressure-lock spring (23), and a sensing control panel (24). The fixing member (21) is connected to a driving module (10). The sliding member (22) is slidably connected to the fixing member (21) and is connected to an electronic lock (3). The sliding member (22) is displaced relative to the fixing member (21) by means of a linear sliding rail (221). The pressure-lock spring (23) is connected between the sliding member (22) and the fixing member (21), and provides an elastic restoring force when the sliding member (22) is displaced relative to the fixing member (21). The elastic restoring force is related to the displacement of the sliding member (22) relative to the fixing member (21). The sensing control panel (24) is fixed to the fixing member (21) and spatially corresponds to the sliding member (22) to sense the displacement of the sliding member (24) relative to the fixing member (21). On the basis of the displacement, the screw fastening robot (1) controls the driving module (10) to drive the downforce control module (2) and the electronic lock (3), so that the electronic lock presses against a screw at a constant pressure while performing a fastening operation.

Description

Down force control module of screw locking robot, screw locking robot and control method thereof TECHNICAL FIELD

[0001] The present application relates to a robot control module, in particular to a down force control module of screw locking robot, screw locking robot and control method thereof. The screw locking robot can accurately control automatic following by the down force control module to complete screw locking and unlocking operations with constant pressure. BACKGROUND

[0002] The "automatic screw locking machine" is an important equipment in the industrial automation process. It can accurately lock screws through intelligent electric drivers, completely replacing the past manual screw locking production mode, and achieving production line automation by cooperating with other intelligent equipment, saving factory labor costs and improving industrial productivity.

[0003] Generally speaking, the down force plays an important role in the locking process of the screw locking robot. Excessive down force can cause damage to the locking object, and too small down force can cause the driver and screw to separate, resulting in a slip.

[0004] However, the current screw locking robot uses air cylinders and springs to control the down force. The electric driver is driven by the air cylinder to lock, which can lock, but the down force changes with the spring and cannot be constant. The length of the locked screw is also limited by the length of the spring and the stroke of the air cylinder, and the down force value cannot be known. The down force can only be changed by manually adjusting the pressure by personnel, and it is impossible to monitor the down force and collect data in real time. In addition, the air cylinder is large in size and can easily affect the end customer's production line configuration.

[0005] Therefore, it is necessary to provide a down force control module of screw locking robot, screw locking robot and control method thereof. The Hall sensor in the down force control module is used as a feedback signal to maintain a certain Hall sensor value during the locking or unlocking process to control the movement of the screw locking robot, accurately control automatic following, and maintain stable down force for screw locking and unlocking operations, solving the shortcomings of the prior art. SUMMARY

[0006] The purpose of the present application is to provide a screw locking robot down pressure control module, screw locking robot and its control method, using the Hall sensor in the down pressure control module as a feedback signal, maintaining a certain Hall sensor value during the locking process or the unlocking process, to control the movement of the screw locking robot, accurately control automatic following, and maintain stable down pressure for screw locking operation and unlocking operation.

[0007] Another purpose of the present application is to provide a screw locking robot down pressure control module, screw locking robot and its control method, which can accurately control automatic following by the down pressure control module, to complete the locking operation and unlocking operation of the screw with constant pressure. The down pressure control module combines Hall sensor and locking spring, allowing the screw locking robot to maintain stable down pressure during the locking operation and unlocking operation of the screw. The down pressure value during the locking operation and unlocking operation can be recorded to monitor the down pressure in real time and feedback immediately when an abnormality occurs. The electric lock does not use Z-axis during the locking and unlocking operation, and does not need to match the feed speed of the Robot locking and unlocking direction. Furthermore, the value of the down pressure sensed by the down pressure control module can also determine whether the screw has successfully entered the screw hole. Compared with the traditional down pressure buffering method using air cylinder and spring, the down pressure control module of the present application combines Hall sensor and locking spring to accurately measure the down pressure value of the locking and unlocking operation, thereby achieving the purpose of real-time monitoring of down pressure and data collection. The application of controlling down pressure for locking and unlocking operation has high flexibility, and the length of the locked and unlocked screw does not affect the constant pressure control of the down pressure. In addition, the down pressure control module composed of Hall sensor and locking spring has the advantages of simple structure, small volume ratio, easy application between mechanical arm and electric lock, low cost and high production efficiency.

[0008] To achieve the foregoing purpose, the present application provides a down pressure control module for a screw locking robot, which is used for screw locking operation of the screw locking robot along a locking direction, wherein the down pressure control module comprises a fixed member, a sliding member, a locking spring and a sensing control board. The fixed member is connected to a driving module of the screw locking robot. The sliding member is slidably connected to the fixed member and is connected to an electric lock. The driving module drives the down pressure control module and the electric lock to displace along the locking direction to perform the screw locking operation. The sliding member comprises a linear slide rail and a magnet. The linear slide rail extends along the locking direction. The magnet of the sliding member allows displacement of the linear slide rail relative to the fixed member. The locking spring is connected between the sliding member and the fixed member to provide an elastic restoring force when the sliding member displaces relative to the fixed member. The elastic restoring force is related to the displacement of the magnet relative to the fixed member. The sensing control board is fixed to the fixed member and is spatially opposite to the magnet. The sensing control board senses the displacement of the magnet relative to the fixed member. The control module of the screw locking robot controls the driving module to drive the down pressure control module and the electric lock to press the screw to perform the locking operation. The elastic restoring force of the locking spring is maintained at a constant value. The electric lock presses the screw at a constant pressure to perform the locking operation.

[0009] In an embodiment, the sensing control board comprises a Hall sensor, which is configured to sense the position of the magnet.

[0010] In an embodiment, the fixed member comprises a limiting column, which protrudes downward from a top end. The top end of the locking spring is fitted on the limiting column. The sliding member comprises a pushing portion, which is spatially opposite to the limiting column and pushes the bottom end of the locking spring, so that the locking spring provides the elastic restoring force between the fixed member and the sliding member.

[0011] In an embodiment, the sliding member further comprises an elastic stopper, which is spatially opposite to the limiting platform of the fixed member. The elastic stopper is arranged at the bottom of the pushing portion to provide an impact buffering function between the sliding member and the fixed member.

[0012] In an embodiment, the elastic stopper is an elastic rubber stopper.

[0013] In an embodiment, the linear slide rail comprises a pair of slide rails, which are respectively arranged along the locking direction. The magnet and the locking spring are located between the pair of slide rails.

[0014] In an embodiment, the fixed member is connected to the driving module through a fixed platform, which is arranged at the bottom end of the fixed member. The sliding member and the fixed platform are respectively located at two opposite sides of the fixed member.

[0015] In an embodiment, the sliding member is connected to the electric lock through a pair of connecting portions, which are respectively arranged adjacent to the top end and the bottom end of the sliding member. The pair of connecting portions and the fixed member are respectively located at two opposite sides of the sliding member.

[0016] To achieve the foregoing, another aspect provides a control method for a screw locking robot, comprising the steps of: (a) providing an electric lock connected to a driving module of the screw locking robot through a downforce control module, wherein the driving module drives the downforce control module and the electric lock to move along a locking direction, and the electric lock performs a screw locking operation along the locking direction, wherein the electric lock connects the screw along the locking direction; (b) the driving module drives the downforce control module and the electric lock to move along the locking direction, so that the screw corresponds to contact a screw hole; (c) after the screw corresponds to contact the screw hole, the electric lock starts to rotate the screw, the driving module drives the downforce control module, the electric lock and the screw to displace along the locking direction, and the downforce control module senses the change of downforce of the electric lock driving the screw; (d) when the downforce reaches a downforce threshold value range, the driving module allows to control the displacement of the downforce control module along the locking direction, and starts the locking operation to maintain the downforce change sensed by the downforce control module within the downforce threshold value range; and (e) when the torque of the electric lock rotating the screw reaches a limit value, the downforce control module stops driving the electric lock and the screw to displace along the locking direction.

[0017] In an embodiment, the control method for the screw locking robot further comprises the steps of: (f) providing the electric lock to perform a screw unlocking operation along an unlocking direction, wherein the driving module drives the electric lock and the downforce control module, so that the electric lock presses down the screw along the locking direction, and the unlocking direction is opposite to the locking direction; (g) the electric lock starts to rotate the screw, the driving module drives the downforce control module, the electric lock and the screw to displace along the locking direction, and the downforce control module senses the change of downforce of the electric lock pressing down the screw; (h) when the downforce reaches a downforce threshold value range, the driving module allows to control the displacement of the downforce control module along the unlocking direction, and starts the unlocking operation to maintain the downforce change sensed by the downforce control module within the downforce threshold value range; and (i) when the torque value of the electric lock rotating the screw reaches a limit value, the downforce control module stops driving the electric lock and the screw to displace along the unlocking direction.

[0018] In one embodiment, the downforce control module comprises a fixed member, a sliding member, a locking spring and a sensing control board. The fixed member is configured to connect to the driving module of the screw locking robot. The sliding member is slidably connected to the fixed member and is configured to connect to an electric screw locker. The driving module drives the downforce control module and the electric screw locker to move along the locking direction to perform the locking operation on the screw. The sliding member comprises a linear slide rail and a magnet. The linear slide rail extends along the locking direction. The magnet of the sliding member allows the linear slide rail to move relative to the fixed member. The locking spring is connected between the sliding member and the fixed member to provide an elastic restoring force when the sliding member moves relative to the fixed member. The elastic restoring force is related to the displacement of the magnet relative to the fixed member. The sensing control board is fixed to the fixed member and is spatially opposite to the magnet. The sensing control board is configured to sense the displacement of the magnet relative to the fixed member. The control module of the screw locking robot controls the driving module to drive the downforce control module and the electric screw locker to press the screw with a downforce to perform the locking operation according to the displacement of the magnet sensed by the sensing control board.

[0019] In one embodiment, the fixed member comprises a limiting column protruding downward from the top end. The top end of the locking spring is fitted on the limiting column. The sliding member comprises a pushing part spatially opposite to the limiting column. The pushing part pushes the bottom end of the locking spring to provide the elastic restoring force between the fixed member and the sliding member.

[0020] In one embodiment, the sliding member further comprises an elastic stopper spatially opposite to the limiting platform of the fixed member. The elastic stopper is arranged at the bottom of the pushing part to provide a shock buffering function between the sliding member and the fixed member.

[0021] In one embodiment, the elastic stopper is an Oligomer stopper composed of low-elasticity rubber.

[0022] In one embodiment, the control module of the screw locking robot records and monitors the change of the downforce of the electric screw locker.

[0023] In one embodiment, the linear slide rail comprises a pair of slide rails extending along the locking direction. The magnet and the locking spring are located between the pair of slide rails.

[0024] In one embodiment, the fixed member is connected to the driving module through a fixed platform arranged at the bottom end of the fixed member. The sliding member and the fixed platform are located at two opposite sides of the fixed member.

[0025] In one embodiment, the sliding member is connected to the electric screw locker through a pair of connecting parts arranged adjacent to the top end and the bottom end of the sliding member. The pair of connecting parts and the fixed member are located at two opposite sides of the sliding member.

[0026] In one embodiment, in step (c), when the change of the downforce fails to reach the downforce threshold value range, it is determined that the screw corresponds to an abnormal screw hole, and the locking operation is stopped.

[0027] To achieve the foregoing purpose, the present application provides a screw locking robot for performing a screw locking operation along a locking direction. The screw locking robot comprises a driving module and a pressing force control module. The pressing force control module is driven by the driving module to move along the locking direction. The pressing force control module comprises a fixed member, a sliding member, a locking spring, and a sensing control board. The fixed member is connected to the driving module of the screw locking robot. The sliding member is slidably connected to the fixed member and is connected to an electric lock. The driving module drives the pressing force control module and the electric lock to move along the locking direction to perform the screw locking operation. The sliding member comprises a linear slide rail and a magnet. The linear slide rail extends along the locking direction. The magnet of the sliding member allows the linear slide rail to move relative to the fixed member. The locking spring is connected between the sliding member and the fixed member to provide an elastic restoring force when the sliding member moves relative to the fixed member. The elastic restoring force is related to the displacement of the magnet relative to the fixed member. The sensing control board is fixed to the fixed member and is spatially opposite to the magnet. The sensing control board senses the displacement of the magnet relative to the fixed member. The control module of the screw locking robot controls the driving module to drive the pressing force control module and the electric lock to press the screw to perform the locking operation. The elastic restoring force of the locking spring is maintained at a constant value. The electric lock presses the screw at a constant pressure to perform the locking operation. BRIEF DESCRIPTION OF DRAWINGS

[0028] The following detailed description and examples of the present application are intended to provide a more complete understanding of the above-mentioned content for those skilled in the art, not to limit the present application.

[0029] Figure 1 is a perspective view of a pressing force control module of an embodiment of the present application combined with a screw locking robot and an electric lock for screw operation;

[0030] Figure 2 is a perspective view of a pressing force control module of an embodiment of the present application combined with an electric lock;

[0031] Figure 3 is a perspective view of a pressing force control module of an embodiment of the present application;

[0032] Figures 4 and 5 are schematic views of the internal structure of a pressing force control module of an embodiment of the present application;

[0033] Figure 6 is a cross-sectional view of a pressing force control module of an embodiment of the present application in an unstressed state;

[0034] Figure 7 is a cross-sectional view of a pressing force control module of an embodiment of the present application in a stressed state;

[0035] Figures 8 to 11 are schematic views of a screw locking robot of the present application controlling an electric lock to perform a screw locking operation through a pressing force control module;

[0036] Figure 12 is a flowchart illustrating the control method of the screw-fastening robot performing screw-fastening operations in an embodiment of this case;

[0037] Figure 13 is a flowchart illustrating the control method of the screw-locking robot performing the unloading operation in this embodiment. 1: Screw-locking robot; 10: Drive module; 2: Downward pressure control module; 21: Fixing component; 211: Limiting platform; 212: Limiting post; 221: Linear slide rail; 222: Magnet; 223: Pushing part; 224: Elastic stop; 22: Sliding component; 23: Locking spring; 24: Sensing control board; 241: Hall sensor; 25: Fixing platform; 26: Connecting part; 3: Electric lock; 9: Screw; 90: Screw hole; D: Spacing distance; H1: First height difference; H2: Second height difference; H3: Third height difference; H4: Fourth height difference; S01~S05, S11~S14: Steps; X, Y, Z: Axis. Detailed Implementation

[0038] Some typical embodiments embodying the features and advantages of this invention will be described in detail in the following description. It should be understood that this invention can have various variations in different implementations, all of which do not depart from the scope of this invention, and the descriptions and drawings herein are for illustrative purposes only and not for limiting the invention. For example, if the following description of a first feature being disposed on or above a second feature indicates that it includes embodiments where the first and second features are in direct contact, and also includes embodiments where additional features may be disposed between the first and second features, so that the first and second features may not be in direct contact. Furthermore, different embodiments in this disclosure may use repeated reference numerals and / or markings. These repetitions are for simplification and clarity and are not intended to limit the relationships between the various embodiments and / or the described appearance structures. Moreover, to facilitate the description of the relationship between one component or feature and another component(s) or feature(s) in the drawings, spatially related terms such as "upper," "lower," "front," "rear," "top," "bottom," and similar terms may be used. In addition to the orientations shown in the accompanying drawings, spatially relevant terms are used to cover different orientations of the device in use or operation. The device may also be otherwise positioned (e.g., rotated 90 degrees or located in other orientations), and the descriptions of the spatially relevant terms used will be interpreted accordingly. Furthermore, when a component is referred to as "connected to" or "coupled to" another component, it may be directly connected to or coupled to the other component, or there may be intervening components. Although the numerical ranges and parameters of the broad scope of this disclosure are approximate, values ​​are stated as precisely as possible in specific examples. Additionally, it is understood that while terms such as "first," "second," etc., may be used in the claims to describe different components, these components should not be limited by these terms, and the components described accordingly in the embodiments are represented by different component symbols. These terms are used to distinguish different components. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component without departing from the scope of the embodiments. The term "and / or" as thus used includes any or all combinations of one or more of the related listed items.

[0039] Figure 1 is a perspective view showing the screw-operating operation of the downward pressure control module combined with the screw-locking robot and the electric lock in an embodiment of this invention. Figure 2 is a perspective view showing the downward pressure control module combined with the electric lock in an embodiment of this invention. Figure 3 is a perspective view showing the downward pressure control module in an embodiment of this invention. Figures 4 and 5 are schematic diagrams of the internal structure of the downward pressure control module in an embodiment of this invention. Figure 6 is a cross-sectional view showing the downward pressure control module in an unloaded state in an embodiment of this invention. Figure 7 is a cross-sectional view showing the downward pressure control module in a loaded state in an embodiment of this invention. Referring to Figures 1 to 7. In this embodiment, this invention provides a downward pressure control module 2 suitable for a screw-locking robot 1, which allows the screw-locking robot 1 to control the electric lock 3 to perform screw-locking operations of the screw 9 downward along the locking direction (e.g., the reverse Z-axis direction). The screw-locking robot 1 includes a drive module 10 and a downward pressure control module 2. The downward pressure control module 2 can be driven by the drive module 10 to move along the locking direction to perform screw-locking operations of the screw 9 along the locking direction.

[0040] In this embodiment, the downward pressure control module 2 includes a fixing member 21, a sliding member 22, a locking spring 23, and a sensing control board 24. The main bodies of the fixing member 21 and the sliding member 22 are, for example, square semi-shells. The rear side of the fixing member 21 is assembled and connected to the drive module 10 of the screw-fastening robot 1. The sliding member 22 is slidably connected to the fixing member 21. The rear side of the sliding member 22 corresponds to the front side of the fixing member 21, and the front side of the sliding member 22 is assembled and connected to an electric lock 3. In this embodiment, the drive module 10 of the screw-fastening robot 1 can drive the downward pressure control module 2 and the electric lock 3 to move downward along the fastening direction to fasten the screw 9. In this embodiment, the sliding member 22 also includes a linear slide rail 221 and a magnet 222, wherein the linear slide rail 221 is, for example, arranged in pairs and extends along the fastening direction. The magnet 222 of the sliding member 22 allows it to move relative to the fixing member 21 by the action of the linear slide rail 221. In this embodiment, the locking spring 23 connects the sliding member 22 and the fixed member 21, providing an elastic restoring force when the sliding member 22 moves relative to the fixed member 21. It is worth noting that in this embodiment, the elastic restoring force provided by the locking spring 23 when the sliding member 22 moves relative to the fixed member 21 is related to the displacement of the magnet 222 relative to the fixed member 21. In this embodiment, the sensing control board 24 is fixed to the fixed member 21 and spatially relative to the magnet 222, sensing the displacement of the magnet 222 relative to the fixed member 21. The control module (not shown) of the screw-locking robot 1, based on the displacement of the magnet 222 sensed by the sensing control board 24, can calculate the elastic restoring force provided by the locking spring 23 when the sliding member 22 moves relative to the fixed member 21, which is the downward pressure of the electric lock 3 on the screw 9. Therefore, the control module of the screw-locking robot 1 can control the drive module 10 to drive the downward pressure control module 2 and the electric lock 3 to press the screw 9 downward pressure based on the displacement of the magnet 222 sensed by the sensing control board 24, to perform the screw-locking operation. In one embodiment, the control module of the screw-locking robot 1 controls the drive module 10 to drive the pressure control module 2, the electric lock 3 and the screw 9 to follow the displacement along the locking direction, so that the elastic restoring force of the locking spring 23 is maintained at a constant value, so that the electric lock 3 presses against the screw 9 with constant pressure to perform the locking operation.

[0041] In this embodiment, the sensing control board 24 includes a Hall sensor 241, which is used to sense the position of the magnet 222, thereby determining the downward pressure exerted by the drive module 10 on the pressure control module 2 and the electric lock 3 to press the screw 9 for locking operations. In this embodiment, the fixing member 21 includes a limiting post 212, which protrudes downward from the top of the fixing member 21, and the top of the locking spring 23 is fitted onto the limiting post 212. In addition, the sliding member 22 includes a pushing part 223, which is spatially opposite to the limiting post 212, and the top of the pushing part 223 pushes against the bottom of the locking spring 23. When the sliding member 22 moves relative to the fixing member 21, the locking spring 23 between the limiting post 212 and the pushing part 223 will be compressed, so that the locking spring 23 provides an elastic restoring force between the fixing member 21 and the sliding member 22. The elastic restoring force is equivalent to the downward pressure exerted by the drive module 10 on the pressure control module 2 and the electric lock 3 to press the screw 9, and can be determined by the displacement of the magnet 222 relative to the fixing member 21 sensed by the sensing control board 24. In this embodiment, the sliding member 22 also includes an elastic stop 224, which is spatially positioned relative to the limiting platform 211 of the fixing member 21. The elastic stop 224 is located at the bottom of the pushing part 223 and is assembled between the sliding member 22 and the fixing member 21 to provide an impact buffer function. In one embodiment, the elastic stop 224 is, for example, a urethane stop made of low-elasticity rubber. Of course, this invention is not limited to this.

[0042] It should be noted that, in this embodiment, the linear slide rail 221 more specifically includes a pair of slide rails, which extend along the locking direction, with the pushing part 223, the magnet 222, and the locking spring 23 located between the pair of slide rails. The magnet 222 is attached to the side of the pushing part 223 and moves synchronously relative to the fixed member 21 along with the sliding member 22. In this way, the sliding member 22 can stably move up and down relative to the fixed member 21, and the sensing control board 24 can sense the position of the magnet 222, thereby knowing the downward pressure of the drive module 10 driving the downward pressure control module 2 and the electric lock 3 to press the screw 9. Of course, this embodiment is not limited to the way the sliding member 22 is slidably connected to the fixed member 21.

[0043] Furthermore, it is worth noting that in this embodiment, the connection between the screw-locking robot 1 and the electric lock 3 is achieved through the downward pressure control module 2. In this embodiment, the fixing member 21 can be connected to the screw spline of the drive module 10 via the fixing platform 25. The fixing platform 25 is located at the bottom end of the fixing member 21, and the sliding member 22 and the fixing platform 25 are located on opposite sides of the front and rear of the fixing member 21, respectively. In addition, the sliding member 22 is connected to the electric lock 3 via a pair of connecting parts 26. The pair of connecting parts 26 are respectively adjacent to the top and bottom ends of the sliding member 22, and the pair of connecting parts 26 and the fixing member 21 are located on opposite sides of the front and rear of the sliding member 22, respectively. Thus, the screw-locking robot 1 drive module 10 can drive the downward pressure control module 2 and the electric lock 3 to move in the locking direction, and when the electric lock 3 is subjected to force, the sliding member 22 will move relative to the fixing member 21, thereby obtaining the downward pressure applied by the electric lock 3 to the screw 9. Of course, this case is not limited to the connection method of the downward pressure control module 2 with the drive module 10 and the electric lock 3.

[0044] Since the connection between the screw-fastening robot 1 and the electric lock 3 is achieved through the downward pressure control module 2, this invention utilizes the Hall sensor 241 in the downward pressure control module 2 as a feedback signal. By maintaining a certain Hall sensor value during the fastening or unlocking process, the movement of the screw-fastening robot 1 can be controlled, accurately controlling automatic following and maintaining stable downward pressure for the fastening and unlocking operations of the electric lock 3 on the screw 9. First, taking the fastening operation as an example. Figures 8 to 11 are schematic diagrams showing the screw-fastening robot controlling the electric lock through the downward pressure control module to perform screw fastening operations. Figure 12 is a flowchart showing the control method of the screw-fastening robot performing fastening operations in this embodiment. Referring to Figures 6 to 12. First, as shown in step S01, an electric lock 3 is provided, which is connected to the drive module 10 of the screw-fastening robot 1 through the aforementioned downward pressure control module 2. The drive module 10 can drive the downward pressure control module 2 and the electric lock 3 to move along the fastening direction (i.e., the reverse Z-axis direction), and the electric lock 3 can perform the fastening operation of the screw 9 along the fastening direction. In this embodiment, the electric lock 3 can connect the screw 9 along the locking direction using simple mechanical force or magnetic attraction, as shown in Figure 8. The lower pressure control module 2 has a first height difference H1 relative to the drive module 10. Next, in step S02, the drive module 10 of the screw-locking robot 1 drives the lower pressure control module 2 and the electric lock 3 to move downward along the locking direction (i.e., the reverse Z-axis direction), so that the screw 9 contacts the screw hole 90. When the screw 9 approaches the screw hole 90, the electric lock 3 can start operating to perform the tooth-finding stage. When the screw 9 contacts the screw hole 90, the reaction force exerted by the screw hole 90 on the screw 9 will be further transmitted to the slider 22 of the lower pressure control module 2. In step S03, after screw 9 contacts screw hole 90, electric lock 3 starts to rotate screw 9. Drive module 10 drives downward pressure control module 2, electric lock 3, and screw to move along the locking direction (i.e., the reverse Z-axis direction). The downward pressure control module 2 uses Hall sensor 241 as feedback signal to sense changes in the downward pressure of electric lock 3 on screw 9. When the downward pressure reaches the downward pressure threshold range, for example, when the displacement of slider 22 relative to fixed member 21 reaches a distance D, as shown in Figure 9, drive module 10 allows control of the displacement of downward pressure control module 2 along the locking direction, thus initiating the locking operation. Fixed member 21 of downward pressure control module 2 has a second height difference H2 relative to drive module 10. After screw 9 contacts screw hole 90, drive module 10 of screw-locking robot 1 further drives fixed member 21 of downward pressure control module 2 to move downward, creating a distance D between slider 22 and fixed member 21. Then, in step S04, electric lock 3 can start rotating screw 9 to perform the locking operation.At this time, the drive module 10 of the screw-locking robot 1 simultaneously drives the downward pressure control module 2, the electric lock 3, and the screw 9 to follow the displacement along the locking direction, and keeps the downward pressure change sensed by the downward pressure control module 2 within the downward pressure threshold value range, that is, maintains the interval distance D between the sliding member 22 and the fixed member 21, as shown in Figure 10. At this time, the fixed member 21 of the downward pressure control module 2 has a third height difference H3 relative to the drive module 10, which is greater than the second height difference H2. Finally, in step S05, when the torque of the electric lock 3 rotating the screw 9 reaches a limit value, the downward pressure control module 2 stops driving the electric lock 3 and the screw 9 to press down and follow the displacement along the locking direction, that is, the screw locking operation is completed. The limit value is, for example, the torque setting value when the locking is successful. At this time, the fixed member 21 of the downward pressure control module 2 has a fourth height difference H4 relative to the drive module 10, which is greater than the second height difference H2. The difference between the fourth height difference H4 and the second height difference H2 is the length of the screw 9 locked into the screw hole 90, which is not related to the interval distance D. It should be noted that if the drive module 10 of the screw-fastening robot 1 further drives the fixing member 21 of the downward pressure control module 2 to move downward beyond the fourth height difference H4, the distance D between the sliding member 22 and the fixing member 21 will increase and will not be able to maintain a constant value. The control module of the screw-fastening robot 1 can also determine that the fastening operation is completed based on this. In other words, the control module of the screw-fastening robot 1 can record and monitor the changes in the downward pressure of the electric lock 3 pressing down on the screw 9. When the torque of the electric lock 3 to rotate the screw 9 fails to produce other abnormalities, the downward pressure control module 2 will stop driving the electric lock 3 and the screw 9 to press down and follow the displacement in the fastening direction. Of course, the application of the downward pressure control module 2 in this case is not limited to this.

[0045] Furthermore, in the aforementioned step S03, when the drive module 10 of the screw-locking robot 1 drives the fixing member 21 of the downward pressure control module 2 to move downward, but the displacement of the sliding member 22 relative to the fixing member 21 cannot reach the interval distance D, that is, the change in downward pressure cannot reach the downward pressure threshold value range, it can be determined that the screw hole 90 corresponding to the screw 9 is abnormal, for example, the screw 9 has deviated from the screw hole 90, and the screw-locking operation is stopped. Of course, this case is not limited to this.

[0046] Similarly, this invention utilizes the Hall sensor 241 in the downward pressure control module 2 as a feedback signal to maintain a stable downward pressure during the unfastening process of the electric lock 3 on the screw 9. Figure 13 is a flowchart illustrating the control method of the screw-fastening robot performing the unfastening operation in this embodiment. Refer to Figures 6 to 11 and Figure 13. First, as shown in step S11, an electric lock 3 is provided and assembled to unfasten the screw 9 along the unfastening direction (i.e., the Z-axis direction). The way in which the electric lock 3 is connected to the drive module 10 of the screw-fastening robot 1 through the downward pressure control module 2 is the same as the aforementioned structure, and will not be described again here. In this embodiment, the drive module 10 will drive the electric lock 3 and the downward pressure control module 2, so that the electric lock 3 presses down on the screw 9 along the fastening direction, while the unfastening direction is opposite to the fastening direction. When the screw 9 contacts the screw hole 90, the reaction force exerted by the screw hole 90 on the screw 9 will be further transmitted to the sliding member 22 of the downward pressure control module 2. Next, in step S12, after the electric lock 3 contacts the screw 9, the electric lock 3 begins to rotate the screw 9. The drive module 10 drives the pressure control module 2, the electric lock 3, and the screw 9 to move along the release direction, and the pressure control module 2 senses the change in the pressure of the electric lock 3 pressing down on the screw 9. When the pressure reaches the pressure threshold range, for example, when the displacement of the sliding member 22 relative to the fixed member 21 reaches a distance D (as shown in Figure 11), the drive module 10 allows the control to move the pressure control module 2 along the release direction, that is, to start the release operation. That is, as shown in step S13, when the electric lock 3 starts to release the screw 9, the drive module 10 drives the pressure control module 2, the electric lock 3, and the screw 9 to follow the displacement along the release direction (i.e., the Z-axis direction), so that the pressure change sensed by the pressure control module is maintained within the pressure threshold range, that is, the distance D between the sliding member 22 and the fixed member 21 is maintained (as shown in Figure 10). Finally, in step S14, when the torque of the electric lock 3 rotating the screw 9 reaches the limit value, it means that the screw 9 is disengaged from the screw hole 90. The limit value is, for example, the torque setting value when disengagement is successful. At this time, the downward pressure control module 2 can stop driving the electric lock 3 and the screw 9 to press down and follow the displacement in the disengagement direction.

[0047] It should be noted that the control module of the screw-fastening robot 1, through the downward pressure control module 2, records and monitors the changes in the downward pressure of the electric lock 3 on the screw 9, which can be adjusted according to actual application requirements and is not limited to simple screw-fastening or screw-unfastening operations. Furthermore, the location of the control module of the screw-fastening robot 1 can be adjusted according to actual application requirements; this application is not limited to this and will not be elaborated further.

[0048] In summary, this invention provides a downward pressure control module and a control method for a screw-fastening robot. Utilizing a Hall sensor in the downward pressure control module as a feedback signal, a certain Hall sensor value is maintained during the screw-fastening or unfastening process to control the robot's movement, accurately control automatic following, and maintain stable downward pressure for screw-fastening and unfastening operations. The downward pressure control module enables the screw-fastening robot to accurately control automatic following, completing screw-fastening and unfastening operations with constant pressure. The downward pressure control module, combined with the Hall sensor and locking spring, allows the screw-fastening robot to maintain stable downward pressure during screw-fastening and unfastening operations. Downward pressure values ​​can be recorded during both fastening and unfastening operations for real-time monitoring and immediate feedback in case of abnormalities. During the fastening and unfastening operations, the Z-axis should not be used, and there is no need to manually adjust the robot's feed speed in the fastening and unfastening directions. Furthermore, the downward pressure value sensed by the downward pressure control module can determine whether the screw has successfully entered the screw hole. Compared to the traditional method of using pneumatic cylinders and springs for downward pressure buffering, the downward pressure control module in this project, combining a Hall sensor and a locking spring, can accurately measure the downward pressure value during locking and unlocking operations, thereby achieving real-time monitoring of downward pressure and data collection. The application flexibility of controlling downward pressure for locking and unlocking operations is high, and the length of the locking and unlocking screws will not affect the constant pressure control. Furthermore, the downward pressure control module, composed of a Hall sensor and a locking spring, has a simple structure and small size, making it easy to apply between robotic arms and electric locks, and offering advantages such as low cost and high production efficiency.

[0049] This case may be modified in various ways by those skilled in the art, but all of them shall not deviate from the protection sought in the claims.

Claims

1. A down force control module for a screw locking robot, the down force control module being configured to perform a screw locking operation on a screw along a locking direction by a driving module of the screw locking robot, wherein the down force control module comprises: a fixed member configured to be coupled to the driving module of the screw locking robot; a sliding member slidably coupled to the fixed member and configured to be coupled to an electric lock, wherein the driving module is configured to displace the down force control module and the electric lock along the locking direction to perform the screw locking operation on the screw, wherein the sliding member comprises a linear slide and a magnet, wherein the linear slide is configured to extend along the locking direction, and the magnet of the sliding member is configured to allow the sliding member to be displaced relative to the fixed member via the linear slide; a locking spring configured to be coupled between the sliding member and the fixed member to provide an elastic restoring force when the sliding member is displaced relative to the fixed member, wherein the elastic restoring force is related to a displacement of the magnet relative to the fixed member; and a sensing control board configured to be fixed to the fixed member and spatially opposite to the magnet, and configured to sense the displacement of the magnet relative to the fixed member, wherein a control module of the screw locking robot is configured to control the driving module to displace the down force control module and the electric lock to press the screw to perform the screw locking operation, such that the elastic restoring force of the locking spring is maintained at a constant value, and the electric lock is configured to press the screw to perform the screw locking operation with a constant force.

2. The down force control module of claim 1, wherein the sensing control board comprises a Hall sensor configured to sense a position of the magnet.

3. The down force control module of claim 1, wherein the fixed member comprises a limiting post configured to protrude downward from a top end, and a top end of the locking spring is configured to be fitted on the limiting post, wherein the sliding member comprises a pushing portion configured to be spatially opposite to the limiting post and configured to push a bottom end of the locking spring, such that the locking spring is configured to provide the elastic restoring force between the fixed member and the sliding member.

4. The down force control module of claim 3, wherein the sliding member further comprises an elastic stopper configured to be spatially opposite to a limiting platform of the fixed member, and the elastic stopper is configured to be disposed at a bottom of the pushing portion to provide a bumping buffering function between the sliding member and the fixed member.

5. The down force control module of claim 4, wherein the elastic stopper is an Olegel stopper made of low-elastic rubber.

6. The down force control module of claim 1, wherein the linear slide comprises a pair of slides configured to extend along the locking direction, and the magnet and the locking spring are disposed between the pair of slides.

7. The down force control module of claim 1, wherein the fixed member is configured to be coupled to the driving module via a fixed platform disposed at a bottom end of the fixed member, and the sliding member and the fixed platform are respectively disposed at two opposite sides of the fixed member. ​ ​ ​ ​ 8. The down force control module of claim 1, wherein the slider connects the electric lock through a pair of connecting portions, the pair of connecting portions are respectively adjacent to the top end and the bottom end of the slider, and the pair of connecting portions are respectively located on the two opposite sides of the slider.

9. A control method of a screw locking robot, comprising steps of: (a). providing an electric lock connected to a driving module of the screw locking robot through a down force control module, wherein the driving module drives the down force control module and the electric lock to move along a locking direction, and the electric lock performs a screw locking operation along the locking direction, wherein the electric lock connects the screw along the locking direction; (b). the driving module drives the down force control module and the electric lock to move along the locking direction, so that the screw corresponds to a screw hole; (c). after the screw corresponds to the screw hole, the electric lock starts to rotate the screw, the driving module drives the down force control module, the electric lock and the screw to displace along the locking direction, and the down force change of the electric lock driving the screw is sensed by the down force control module; (d). when the down force reaches a down force threshold value range, the driving module allows to control the displacement of the down force control module along the locking direction, and starts the locking operation to maintain the down force change sensed by the down force control module within the down force threshold value range; and (e). when the torsion of the electric lock rotating the screw reaches a limit value, the down force control module stops driving the electric lock and the screw to displace along the locking direction.

10. The control method of the screw locking robot of claim 9, further comprising steps of: (f). providing the electric lock to perform a screw unlocking operation along an unlocking direction, wherein the driving module drives the electric lock and the down force control module, so that the electric lock presses the screw along the locking direction, and the unlocking direction is opposite to the locking direction; (g). the electric lock starts to rotate the screw, the driving module drives the down force control module, the electric lock and the screw to displace along the unlocking direction, and the down force change of the electric lock pressing the screw is sensed by the down force control module; (h). when the down force reaches the down force threshold value range, the driving module allows to control the displacement of the down force control module along the unlocking direction, and starts the unlocking operation to maintain the down force change sensed by the down force control module within the down force threshold value range; and (i). when the torsion of the electric lock rotating the screw reaches the limit value, the down force control module stops driving the electric lock and the screw to displace along the unlocking direction.

11. The control method of the screw locking robot of claim 9, wherein the down force control module comprises: a fixed part configured to be connected to the driving module of the screw locking robot; a sliding member slidably connected to the fixed member and configured to be coupled to the electric lock, wherein the sliding member comprises a linear slide and a magnet, and wherein the magnet of the sliding member allows displacement of the linear slide relative to the fixed member; a compression spring connected between the sliding member and the fixed member to provide a resilient restoring force when the sliding member is displaced relative to the fixed member, wherein the resilient restoring force is related to the displacement of the magnet relative to the fixed member; and a sensing control board fixed to the fixed member and spatially opposite to the magnet, configured to sense the displacement of the magnet relative to the fixed member, wherein a control module of the screw locking robot controls the driving module to drive the electric lock to press the screw with the pressing force according to the displacement of the magnet sensed by the sensing control board.

12. The control method of the screw locking robot according to claim 11, wherein the sensing control board comprises a Hall sensor configured to sense the position of the magnet.

13. The control method of the screw locking robot according to claim 11, wherein the fixed member comprises a limiting post protruding downward from a top end, and a top end of the compression spring is fitted onto the limiting post, and wherein the sliding member comprises a pushing portion spatially opposite to the limiting post and configured to push a bottom end of the compression spring, so that the compression spring provides the resilient restoring force between the fixed member and the sliding member.

14. The control method of the screw locking robot according to claim 13, wherein the sliding member further comprises a resilient stopper spatially opposite to a limiting platform of the fixed member, and the resilient stopper is arranged at a bottom of the pushing portion and configured to provide a shock buffering function between the sliding member and the fixed member, and wherein the resilient stopper is an Olegel stopper made of low-resilience rubber.

15. The control method of the screw locking robot according to claim 11, wherein the control module of the screw locking robot records and monitors the change of the pressing force of the electric lock pressing the screw.

16. The control method of the screw locking robot according to claim 11, wherein the linear slide comprises a pair of slides respectively arranged along the locking direction, and the magnet and the compression spring are located between the pair of slides.

17. The control method of the screw locking robot according to claim 11, wherein the fixed member is connected to the driving module through a fixed platform arranged at a bottom end of the fixed member, and the sliding member and the fixed platform are respectively located at two opposite sides of the fixed member.

18. The control method of the screw locking robot according to claim 11, wherein the sliding member is connected to the electric lock through a pair of connecting portions respectively arranged adjacent to a top end and a bottom end of the sliding member, and the pair of connecting portions and the fixed member are respectively located at two opposite sides of the sliding member.

19. The control method of the screw locking robot according to claim 9, wherein in the step (c), when the variation of the pressing force fails to reach the range of the pressing force threshold value, it is determined that the screw corresponds to the screw hole abnormally, and the locking operation is stopped.

20. A screw locking robot for performing a locking operation of a screw in a locking direction, the screw locking robot comprising: a driving module; and a pressing force control module driven by the driving module to displace along the locking direction, the pressing force control module comprising: a fixed member assembled and connected to the driving module of the screw locking robot; a sliding member slidably connected to the fixed member and assembled and connected to an electric lock, wherein the driving module drives the pressing force control module and the electric lock to displace along the locking direction to perform the locking operation on the screw, wherein the sliding member comprises a linear slide rail and a magnet, wherein the linear slide rail is arranged to extend along the locking direction, and the magnet of the sliding member allows displacement of the linear slide rail relative to the fixed member; a pressing spring connected between the sliding member and the fixed member to provide an elastic restoring force when the sliding member displaces relative to the fixed member, wherein the elastic restoring force is related to the displacement of the magnet relative to the fixed member; and a sensing control board fixed to the fixed member and spatially opposite to the magnet to sense the displacement of the magnet relative to the fixed member, wherein the control module of the screw locking robot controls the driving module to drive the pressing force control module and the electric lock to press the screw to perform the locking operation according to the sensing control board sensing the displacement of the magnet, so that the elastic restoring force of the pressing spring is maintained at a constant value, and the electric lock presses the screw at a constant pressing force to perform the locking operation.

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