TWI715065B - Screw system - Google Patents

Abstract

A screw system includes an actuator, a screw machine and a controller. The actuator has a stationary portion and a movable portion that is linearly displaceable in the vertical direction. The screw machine has a body, a drive motor and a screwdriver, and the body is disposed at the movable portion and can be linearly displaced in the vertical direction. The drive motor is disposed on the body. The screwdriver can be driven to rotate by the drive motor, and the screwdriver is used to engage the to-be-screwed screw. The controller is connected electrically with the actuator and the screw machine. The to-be-screwed screw has a threaded section, and the threaded section has a pitch. The controller demands the drive motor to drive the screwdriver to rotate the preset number of turns, and also demands the actuator to drive the movable portion to linearly displace a relative length in a vertical direction. The relative length is equal to the preset number of turns multiplied by the pitch, and the speed of the actuator is equal to the speed of the screwdriver multiplied by the pitch.

Description

Screwing system

A screw-tightening system, in particular, a screw-tightening system in which an actuator and a screw machine are in use, and the two have a matching displacement in the vertical direction.

Locking screw machines are widely used in the manufacturing industry. For manufacturers, the operating performance, use efficiency and service life of the locking screw machines are very important to the production capacity of the industry.

Most of the locking screw machines used in the market cannot be used at variable speeds during the tightening process. They often run at a spiral speed and cannot be adjusted elastically for a variety of locked objects.

In addition, the traditional locking screw machine is set on the vertical axis (Z axis) of the robot arm, but because the pitch of the vertical axis of the robot arm is much larger than the pitch of the screw to be locked, the displacement stroke of the robot arm often cannot accurately match the screw locking process The vertical stroke (Z-axis stroke) and the speed of the movement.

In order to avoid this problem, the prior art installs a buffer, such as a spring or a pneumatic cylinder, between the vertical axis of the robot arm and the screw machine to adjust the problem that the stroke and speed of the robot arm and the screw machine cannot be accurately matched. The pneumatic cylinder will exert unnecessary vertical force on the screw to be locked, increasing the difficulty of screw locking, and increasing the possibility of tooth collapse or increasing the degree of screw wear.

Compared with tightening the screws, there is also a need to loosen the screws. The traditional locking screw machine often cannot accurately find the screws and combine the screw cap head grooves to further perform the operation of loosening the screws.

Therefore, how to design a screw-tightening system with good performance, easy operation and capable of improving the above-mentioned problems is a subject that professionals in related fields need to study.

In view of this, an embodiment of the present invention provides a screwing system for a vertical arm of a robotic arm system, including an actuator, a screwing machine, and a controller.

The actuator is provided on the vertical arm. The actuator has a stationary part that is stationary relative to the vertical arm and a movable part that can be linearly displaced relative to the vertical arm in the vertical direction; the screwdriver has a body, a drive motor, and a screwdriver. The movable part can be linearly displaced with the movable part in the vertical direction. The driving motor is arranged on the body. The screwdriver can be driven to rotate by the driving motor, and the screwdriver is used to engage the screw to be screwed; the controller is electrically connected to the actuator and screwing the screw. machine. Wherein, the screw to be screwed has a threaded section, and the threaded section has a pitch. The controller is used to control the drive motor to drive the screwdriver to rotate a preset number of turns, and at the same time to make the actuator drive the movable part to linearly shift the relative length in the vertical direction, the relative length is The product of the number of turns and the pitch is preset, and the moving speed of the actuator in the vertical direction is equal to the product of the rotation speed of the screwdriver and the pitch.

As with the screwing system described above, in one embodiment, the actuator is a servo stepper motor.

Like the above-mentioned screwing system, in one embodiment, the screwing machine further includes a torque detection module for sensing the torque value of the screw to be screwed, and the controller is used for the torque detected by the torque detection module When the value reaches the preset torque value, the drive motor will stop driving the screwdriver to rotate.

Like the above-mentioned screwing system, in one embodiment, the screwing machine further includes a torque detection module for sensing the torque value of the screw to be screwed, and the controller is used for the torque detected by the torque detection module When the value reaches the preset torque value, the movable part stops moving in the vertical direction.

Like the screw-screw system described above, in one embodiment, the actuator further includes a displacement detection module for sensing the relative displacement of the movable part in the vertical direction, and the controller is used for sensing in the torque detection module When the torque is equal to the preset torque value, it is determined whether the relative displacement sensed by the displacement detection module reaches the preset displacement, and when the relative displacement is less than the preset displacement, a warning signal is issued.

Like the above-mentioned screwing system, in one embodiment, the actuator further has a current detection module for sensing the operating current of the actuator, and the controller is further used for the work sensed by the current detection module When the current reaches the preset current, the movable part is stopped from displacement in the vertical direction.

Like the screw screwing system described above, in one embodiment, the controller is used to set at least two screw screw parameters, and the controller is used to control the screwdriver to rotate with different parameters when the screw parameters are different.

As with the above-mentioned screwing system, in one embodiment, the controller is also used to set a movement parameter of the actuator to control the movement of the actuator in the vertical direction.

Through the screwing system provided by one or more of the above embodiments, the screwing machine and the actuator can move the same displacement in the vertical direction. In this way, the robot arm can be actuated without additional buffers. The device can accurately match the vertical stroke of the screwdriver in the process of screwing the screw, and solve the problems encountered by the prior art.

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a schematic diagram of the structure of an embodiment of the screwing system 1 of the present invention. FIG. 2 is a schematic diagram of the appearance of an embodiment of the screwing system 1 of the present invention.

The screwing system 1 can be installed on a vertical arm (not shown in the figure) in a robotic arm system. The screwing system 1 includes an actuator 11, a screwing machine 12 and a controller 13.

The actuator 11 is arranged on a vertical arm, and the actuator 11 has a stationary part 111 that is stationary relative to the vertical arm and a movable part 112 that can linearly shift relative to the vertical arm in the vertical direction. In this embodiment, the movable portion 112 includes a sliding rail 1121 and a sliding table 1122.

The screwdriver 12 has a main body 121, a drive motor 122, and a screwdriver 123. The main body 121 is disposed on the movable part 112 and can be linearly displaced with the movable part 112 in the vertical direction. In this embodiment, the main body 121 is installed via two flanges 14. It is provided on the movable portion 112, whereby the movable portion 112 drives the main body 121 to move in the vertical direction.

The driving motor 122 is arranged inside the main body 121 and drives the screwdriver 123 to rotate. The screwdriver 123 is used to engage the screw 2 to be screwed (see Figure 3 and Figure 4).

The controller 13 is electrically connected to the actuator 11 and the screwing machine 12 respectively. In some embodiments, the controller 13 is a computer. In other embodiments, the controller 13 includes a first control module and a second control module, which control the operation of the actuator 11 and the screwdriver 12 respectively.

The screw 2 to be screwed has a threaded section 21, and the threaded section 21 has a pitch D. The controller 13 is used to control the driving motor 122 to drive the screwdriver 123 to rotate a preset number of turns, and at the same time to make the actuator 11 drive the movable part 112 linearly in the vertical direction The relative length of the displacement, the relative length is equal to the product of the preset number of turns and the pitch D. In addition, the moving speed of the actuator 11 in the vertical direction is the product of the rotation speed of the screwdriver 123 and the screw pitch.

In other words, the pitch D is the distance between the threads. The screwdriver 123 drives the screw 2 to be screwed to rotate. During the rotation of the screw 2 to be screwed, the displacement in the vertical direction corresponds to a considerable length of the movable portion 112.

In some embodiments, the actuator 11 is a servo stepper motor, which has both the characteristics of a servo motor and the characteristics of a stepper motor.

In the embodiment shown in FIG. 1, the screwdriver 12 further includes a torque detection module 124, which can sense the torque value of the screw 2 to be screwed, that is, the screw 2 to be screwed Turn it into the screw hole of the object to be locked. During the rotation of the screw 2 to be tightened, resistance may be encountered. The screw 2 to be tightened will generate the feedback torque value. The torque value is preset in the controller 13. When the device 13 determines that the torque value sensed by the torque detection module 124 reaches the preset torque value, the drive motor 122 stops driving the screwdriver 123 to rotate, so as to protect the screwdriver 123, the screw 2 to be tightened, and the object to be tightened (that is, to avoid damage Locked objects and collapsed teeth occurred).

In addition, in some embodiments, when the torque value returned by the screw 2 to be screwed reaches the preset torque value, the controller 13 can also stop the movable part 112 from moving in the vertical direction, that is, fix the screw machine 12 in the vertical direction. A position on the upper side, so that it no longer moves downward, to protect the screwdriver 12.

Please refer to FIG. 1 again. In this embodiment, the actuator 11 further includes a displacement detection module 113. The displacement detection module 113 can sense the relative displacement of the movable part 112 in the vertical direction. When the torque sensed by the detection module 124 is equal to the preset torque value, the controller 13 determines whether the relative displacement sensed by the displacement detection module 113 reaches the preset displacement, and when the relative displacement is less than the preset displacement To issue a warning signal.

That is to say, the industry can set the depth of the screw hole rotation locking of the screw 2 to be tightened in the locking object through the controller 13, that is, the preset displacement. As mentioned above, the screw 2 to be locked is rotated vertically during use. The amount of movement in the direction is equivalent to the amount of displacement of the movable part 112 in the vertical direction (that is, the relative displacement of the side sensed by the displacement detection module 113). When the torque sensed by the torque detection module 124 is equal to the preset torque value, The controller 13 determines whether the relative displacement sensed by the displacement detection module 113 has reached the preset displacement. If it has reached the preset displacement, it means that the screw 2 to be tightened has been successfully locked (tightened). If the relative displacement is When the displacement is less than the preset displacement, the controller 13 sends out a warning signal, indicating that there is a problem in the tightening process of the screw 2 to be tightened. In some embodiments, the controller 13 includes an alarm module (not shown in the figure), and the alarm signal is notified to the industry through the effect of sound and light through the alarm module.

Please refer to FIG. 1 again. In this embodiment, the actuator 11 further has a current detection module 114. The current detection module 114 senses the operating current of the actuator 11, and the controller 13 is further used for current detection. When the working current sensed by the measuring module 114 reaches the preset current, the movable part 112 is stopped from moving in the vertical direction.

In other words, when the actuator 11 is in use, the screwdriver 12 may encounter resistance in the vertical direction, causing the operating current provided by the actuator 11 to gradually increase to make the screwdriver 12 in the vertical direction. The movement in the direction is smooth, but when the operating current reaches the preset current, there may be a risk of damaging the screwdriver 12, the screw 2 to be screwed, and the locked object at this time, and the controller 13 stops the movable part 112 from moving.

In addition, in some embodiments, the controller 13 may further stop the driving motor 122 from driving the screwdriver 123 to rotate when the operating current sensed by the current detection module 114 reaches a preset current.

Please refer to FIG. 3 and FIG. 4. FIG. 3 is a schematic diagram of the setting of an embodiment of the controller 13 of the screw locking system 1 of the present invention in a tightening state. 4 is a schematic diagram of the setting of an embodiment of the controller 13 of the screw locking system 1 of the present invention in a loosening state.

The controller 13 can set at least two screwing parameters, and further control the screwdriver 123 to rotate with different parameters, and at the same time control the actuator movable part 112 to move with different parameters. As shown in Figure 3, in a tightened state, the screw parameters that the controller 13 can set are the preset number of turns C of the screw 2 to be tightened and the corresponding rotation speed SP, the preliminary distance W between the locked object, and the The upper limit value P1 of the pressure that the screw 2 can tolerate during locking, the tolerable width TW in the horizontal direction in the thread of the object to be locked, and so on. As shown in Figure 4, in a loosened state, the screwing parameters such as the search speed S and search pressure P2, search distance SW, preset number of turns C and The corresponding rotation speed SP and the distance FW from the object to be released after the work is completed. The above-mentioned screw-tightening parameters are examples, and the present invention does not limit these screw-tightening parameters.

Through the screwing system 1 provided by one or more of the above embodiments, the screwing machine 12 and the actuator 11 can move the same displacement in the vertical direction. In this way, the robot arm does not need to be additionally equipped with a buffer. The actuator 11 can accurately match the vertical stroke and moving speed of the screw locking machine 12 during the screw locking process.

In some embodiments, the screw-locking machine 12 further includes a torque detection module 124. With the operation of the torque detection module 124, the controller 13 can stop the driving motor 122 from driving the screwdriver 123 to rotate to protect Screwdriver 123, the screw 2 to be screwed, and the object to be locked (that is, to avoid damage to the object to be locked and tooth collapse). Or, the movable part 112 is stopped to move in the vertical direction, that is, a position of the locking screw machine 12 in the vertical direction is fixed so that it does not move downwards, and the locking screw machine 12 is protected.

In addition, in some embodiments, via the displacement detection module 113, when the torque sensed by the torque detection module 124 is equal to the preset torque value, the controller 13 determines the relative displacement sensed by the displacement detection module 113 Whether the preset displacement is reached, and when the relative displacement is less than the preset displacement, a warning signal is issued, indicating that there is a problem with the screw 2 to be tightened during the tightening process.

In addition, in some embodiments, through the operation of the current detection module 114, the controller 13 can stop the movable part 112 in the vertical direction when the operating current sensed by the current detection module 114 reaches a preset current. Displacement. Furthermore, the controller 13 can also stop the driving motor 122 from driving the screwdriver 123 to rotate, so as to protect the actuator 11 and the screwdriver 12.

In other words, through the above-mentioned multiple embodiments, the screw screwing system of the present invention has multiple functions, which can enhance the positioning accuracy, the control of the moving speed and the pressure, and simplify the screw screwing procedure, which is extremely beneficial.

1...Lock screw system 11... Actuator 111...Static part 112...movable part 1121...Slide 1122...sliding table 113...Motion detection module 114...Current detection module 12... Screwing machine 121... ontology 122...Drive motor 123...Screwdriver 124... Torque detection module 13... Controller 14...Flange 2...Screw to be tightened 21...thread section C... preset number of turns D...Pitch FW...distance P1…upper pressure limit P2...search pressure W...preparation distance S...Search speed SP...speed SW...Search distance TW...tolerable width

[Figure 1] is a schematic diagram of an embodiment of the screw locking system of the present invention. [Figure 2] is a schematic diagram of the appearance of an embodiment of the screw locking system of the present invention. [Figure 3] is a schematic diagram of the setting of an embodiment of the controller of the screw locking system of the present invention in a tightening state. [Figure 4] is a schematic diagram of the setting of an embodiment of the controller of the screw locking system of the present invention in a loosened state.

11... Actuator 111...Static part 112...movable part 12... Screwing machine 121... ontology 123...Screwdriver

Claims (7)

A screw-tightening system for a vertical arm of a robotic arm system, comprising: an actuator for installing on the vertical arm, the actuator having a stationary part that is stationary relative to the vertical arm and an A movable part linearly displaced in the vertical direction; and a screwdriver having a body, a drive motor, and a screwdriver, the body is provided on the movable part and can linearly shift in the vertical direction with the movable part, the The drive motor is provided on the body, the screwdriver can be driven to rotate by the drive motor, and the screwdriver is used to engage a screw to be screwed; and a controller electrically connected to the actuator and the screwdriver respectively; wherein the The actuator further includes a displacement detection module and a torque detection module. The torque detection module is used to sense the torque value of the screw to be tightened. The displacement detection module is used to sense the A relative displacement of the movable part in the vertical direction, the controller is used to determine the relative displacement sensed by the displacement detection module when the torque sensed by the torque detection module is equal to a preset torque value Whether the amount reaches a preset displacement amount, and when the relative displacement amount is less than the preset displacement amount, a warning signal is issued; wherein the screw to be screwed has a thread section, the thread section has a pitch, and the controller is used The drive motor is controlled to drive the screwdriver to rotate a predetermined number of turns, and the controller is used to make the actuator drive the movable part to linearly shift in the vertical direction by a relative length, and the relative length is equal to the predetermined number of turns and The product of the pitch, and the moving speed of the actuator in the vertical direction is equal to the product of the rotation speed of the screwdriver and the pitch. The screwing system according to claim 1, wherein the actuator is a servo stepping motor. The screwing system according to claim 1, wherein the controller is configured to stop the driving motor from driving the screwdriver to rotate when the torque value sensed by the torque detection module reaches a preset torque value. The screwing system according to claim 1, wherein the controller is configured to stop the movable part from moving in the vertical direction when the torque value sensed by the torque detection module reaches a preset torque value. The screwing system of claim 1, wherein the actuator further has a current detection module for sensing the operating current of the actuator, and the controller is further used for the current detection module When the sensed working current reaches a preset current, the movable part is stopped from displacement in the vertical direction. The screwing system according to claim 1, wherein the controller is used to set at least two screwing parameters, and the controller is used to control the screwdriver to rotate with different parameters when the screwing parameters are different. The screwing system according to claim 6, wherein the controller is also used to set a movement parameter of the actuator to control the movement of the actuator in the vertical direction.

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