Energy storage return force type servo system and control method

Abstract

The application provides an energy storage and return force type servo system and a control method, the servo system comprising a servo driver and a servo motor connected through a control line, one end of the servo motor being provided with an energy storage and return force disc and a planetary gear disc; the energy storage and return force disc being provided with an energy storage spring and a sliding block connected through a hydraulic mechanism; the planetary gear disc comprising a sun gear, a planet gear and an outer gear ring in mesh connection, a rotating shaft of the servo motor being connected with the sun gear through a key groove, the outer gear ring being in transmission connection with a mechanical arm, and the outer gear ring being provided with a push rod rotating synchronously, the push rod having the same movement radius as the sliding block; when the mechanical arm is turned down, the push rod pushes the sliding block after freely rotating for a stroke, so as to compress the energy storage spring to store energy; when the mechanical arm is turned up, the energy storage spring rebounds and provides auxiliary power for turning up of the mechanical arm. The servo system replaces the reverse driving forced stop of the mechanical arm by the energy storage and return force mode, and replaces the brake module, so that energy can be saved and motor heating can be reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of motor servo systems, in particular to an energy storage and return type servo system and a control method. BACKGROUND

[0002] A motor servo system is widely applied in high-end manufacturing industries such as numerical control machine tools and robots, and is composed of a servo driver and a servo motor, wherein the servo driver can control the servo motor through position, speed and torque to realize high-precision transmission positioning. In order to meet various application scenarios, the servo motor not only needs to be selected in type, but also needs to be equipped with accessories for special scenarios, and the servo driver also needs to modify parameters, select control modes and even update control software according to application scenarios.

[0003] For example, a mechanical arm rotating vertically, in order to accurately control its action, a servo motor is mostly used as the power source for its rotation. Affected by the gravity torque of the mechanical arm itself and the load, the servo motor needs to provide reverse power to force the mechanical arm to stop at the set position in the mechanical arm downward turning deceleration stage. The servo motor needs to consume a large amount of electric energy in the whole stroke, and the heat generation is high. According to the actual working condition, a heat dissipation module also needs to be selected and installed. In addition, in order to avoid the servo motor out of control and downward turning when the power is suddenly cut off, a brake module also needs to be installed on the servo motor. The heat dissipation module and the brake module increase the installation cost and installation space of the servo system, and the high power consumption of the servo motor is not conducive to energy saving and environmental protection. SUMMARY

[0004] In view of the defects in the background art, the application provides an energy storage and return type servo system and a control method. The energy storage and return type servo system replaces the reverse driving of the motor to force the mechanical arm to stop by the energy storage and return type when the mechanical arm is downward turning, thereby reducing the energy consumption and heat generation. In addition, the energy storage and return type disc can replace the brake module to reduce the cost and save the installation space.

[0005] The application provides an energy storage and return type servo system, which comprises a servo driver and a servo motor connected through a control line, and the servo motor is provided with an energy storage and return type disc and a planetary gear disc at one end.

[0006] The energy storage and return type disc is provided with an energy storage spring and a sliding block connected through a hydraulic mechanism.

[0007] The planetary gear disc comprises a sun gear, a planet gear and an outer gear ring in meshing connection, the rotating shaft of the servo motor is connected with the sun gear through a key groove, the outer gear ring is in transmission connection with the mechanical arm, and the outer gear ring is provided with a push rod rotating synchronously, and the push rod has the same movement radius as the sliding block.

[0008] When the mechanical arm is downward turning, the push rod drives the sliding block after rotating freely for a stroke, so as to compress the energy storage spring to store energy.

[0009] When the mechanical arm is turned up, the energy storage spring rebounds and provides auxiliary power for the mechanical arm to turn up.

[0010] The middle part of the energy storage return disc is provided with a shaft hole for passing through the rotating shaft, and the hydraulic mechanism comprises an annular oil storage box arranged at the periphery of the shaft hole.

[0011] The outer end of each oil groove is provided with a small piston rod, each piston rod is connected with a sliding block, and the outer gear ring is arranged at equal angles and is provided with a plurality of push rods corresponding to the sliding blocks.

[0012] The annular oil storage box is also arranged at equal angles and is provided with a plurality of large piston rods moving in the radial direction, and each large piston rod is connected with a group of energy storage springs.

[0013] The radial periphery of the oil storage box is provided with an annular energy storage cavity, and a plurality of radial guide spokes are arranged in the energy storage cavity.

[0014] The large piston rod comprises a rod body and top plates arranged on both sides of the rod body, the top plates abut against one end of each energy storage spring of the corresponding group near the shaft hole, and the top plates are also provided with perforations for passing through the guide spokes.

[0015] The outer ring wall of the energy storage cavity is provided with an electromagnetic lock corresponding to the large piston rod, the electromagnetic lock is opposite to the radial outer end of the rod body, and the electromagnetic lock is connected with the servo driver through a control line.

[0016] Preferably, the energy storage return disc is located between the servo motor and the planetary gear disc, and the energy storage return disc is provided with a ring of adjusting teeth on the side opposite to the servo motor, and the housing end face of the servo motor is provided with a tooth ring seat matched with the adjusting tooth ring.

[0017] Preferably, the oil groove is provided with a serpentine buffer section.

[0018] Preferably, the energy storage return disc is provided with an arc-shaped sliding groove, and the sliding block and the push rod are limited to rotate in the arc-shaped sliding groove.

[0019] The application also provides a servo system control method, which controls the mechanical arm to turn up and down reciprocatingly through the energy storage return type servo system control mechanical arm according to any one of the above technical solutions.

[0020] The turning period of the mechanical arm is divided into four strokes:

[0021] In stroke 1, the mechanical arm is accelerated to turn down from the starting position A at the highest point under the drive of the servo motor, and the push rod is free to rotate.

[0022] When the mechanical arm rotates by an angle α, the push rod contacts the slider, the servo motor stops supplying power, the slider rotates together under the action of inertia and the gravity of the mechanical arm, and the slider is driven by the hydraulic mechanism, the large piston rod of the hydraulic mechanism lifts the force storage spring to be compressed until the mechanical arm reaches the lowest point;

[0023] In the third stroke, the servo motor is powered again to drive the mechanical arm to turn upward, and the force storage spring is stretched to recover, the slider is driven by the hydraulic mechanism to rotate in the opposite direction, and the slider drives the push rod to rotate the outer gear ring;

[0024] In the fourth stroke, the slider is separated from the push rod, and the mechanical arm continues to turn upward under the drive of the servo motor until it returns to the starting position.

[0025] Preferably, when the mechanical arm reaches the lowest point, the electromagnetic lock is powered on and locked, and the electromagnetic lock is powered off after a preset value n seconds, and the servo motor is powered on again.

[0026] Preferably, when the energy storage return force type servo system is powered off, the mechanical arm automatically rotates to the set position B under the action of the energy storage spring.

[0027] Under the control of the servo driver, the beneficial effects of the present application include:

[0028] 1. The energy storage return force disc is provided with an energy storage spring, which replaces the motor reverse drive to stop the mechanical arm when the mechanical arm turns downward, thereby reducing energy consumption and heat generation;

[0029] 2. When the power is suddenly cut off, the energy storage spring will push the mechanical arm back to the set position and stop moving, so that the energy storage return force disc replaces the brake module, thereby reducing the cost and saving the installation space;

[0030] 3. The hydraulic mechanism and the energy storage spring in the energy storage return force disc play a double buffering role to avoid the whistling or trembling of the servo motor when it slows down;

[0031] 4. The energy storage return force disc is radially arranged with multiple ring springs, which can disperse the gravity and inertia when the mechanical arm turns downward;

[0032] 5. The energy storage return force disc can make good use of space through the distribution of the hydraulic mechanism and the ring spring, thereby reducing the overall installation space of the servo motor;

[0033] 6. The electromagnetic lock can control the dwell time of the mechanical arm at the lowest point, allowing the mechanical arm to work at this position, and the electromagnetic lock fully utilizes the large piston rod structure of the hydraulic mechanism to realize the mechanical arm dwell function at low cost. BRIEF DESCRIPTION OF DRAWINGS

[0034] The present application will be described in detail below in conjunction with the embodiments and drawings.

[0035] Figure 1 is the structural schematic diagram of the energy storage return force type servo system of the present application.

[0036] Figure 2 is the outline drawing of the servo motor in the energy storage return force type servo system of the present application.

[0037] Figure 3 is the structural exploded view of the servo motor in the energy storage return force type servo system of the present application.

[0038] Figure 4 is the sectional view of the servo motor in the energy storage return force type servo system of the present application.

[0039] Figure 5 is the sectional view of the energy storage return force disc in the energy storage return force type servo system of the present application.

[0040] Figure 6 is the structural schematic diagram of the large piston rod in the energy storage return force type servo system of the present application.

[0041] Figure 7 is the position schematic diagram of the mechanical arm in the servo system control method of the present application.

[0042] Reference signs:

[0043] 1 - mechanical arm, 2 - servo driver, 3 - servo motor, 31 - rotating shaft, 32 - shell, 321 - tooth ring seat, 33 - encoder, 34 - motor rotor, 35 - motor stator, 36 - motor inner partition, 37 - motor rear cover, 4 - energy storage return force disc, 41 - energy storage spring, 411 - energy storage cavity, 412 - guide spoke, 42 - sliding block, 43 - arc-shaped sliding groove, 44 - shaft hole, 45 - oil storage box, 46 - oil groove, 461 - serpentine buffer section, 47 - small piston rod, 48 - large piston rod, 481 - rod body, 482 - top plate, 49 - adjusting tooth ring, 5 - planetary gear disc, 51 - sun gear, 52 - planet wheel, 53 - outer gear ring, 54 - push rod, 6 - electromagnetic lock, 7 - transmission cover. DETAILED DESCRIPTION

[0044] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clearly understood, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0045] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0046] The principles of the present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0047] Figure 1 A robotic arm 1 installed on an assembly line is shown. The robotic arm 1 can rotate to the highest point to pick up a workpiece and then place the workpiece on a conveyor belt (not shown) at the lowest point.

[0048] like Figures 2-6 As shown, the energy storage and return type servo system proposed in this invention can be used in... Figure 1 The robotic arm 1 shown includes a servo system comprising a servo driver 2 and a servo motor 3 connected via control lines. The servo motor 3 is fixedly mounted on a base and drives the robotic arm 1 to rotate up and down. The servo driver 2 controls the operation of the servo motor 3. One end of the servo motor 3 is equipped with an energy storage return plate 4 and a planetary gear disk 5. The planetary gear disk 5 acts as a speed reducer, comprising a sun gear 51, planetary gears 52, and an external gear ring 53 meshing together. The sun gear 51 is connected to the shaft 31 of the servo motor 3 via a keyway, and the external gear ring 53 is connected to the robotic arm 1 via a transmission mechanism. The energy storage return plate 4 is equipped with an energy storage spring 41 and a slider 42 connected via a hydraulic mechanism. The external gear ring 53 is equipped with a synchronously rotating push rod 54, which has the same radius of motion as the slider 42. The energy storage return plate 4 is equipped with an arc-shaped groove 43, within which the slider 42 and the push rod 54 are confined to rotate. When the robotic arm 1 tilts down, the push rod 54 rotates freely for a certain distance and then contacts the slider 42, pushing the slider 42 to rotate together. The slider 42 stores energy by pressing the energy storage spring 41 through the hydraulic mechanism. When the robotic arm 1 tilts up, the energy storage spring 41 rebounds and provides auxiliary power for the robotic arm 1 to tilt up, helping the servo motor 3 to drive the robotic arm 1 to tilt up until the slider 42 separates from the push rod 54.

[0049] The traditional servo system generally helps the mechanical arm 1 to reduce the angular velocity by providing reverse power to the servo motor 3 until the mechanical arm 1 is forced to stop, but this forced stopping method not only consumes a lot of power, but also the coil will inevitably heat up when the motor works. The embodiment uses the energy storage spring 41 to replace the motor reverse driving to force the mechanical arm 1 to stop by the energy storage return force when the mechanical arm 1 is turned down, and the servo motor 3 does not work in the part of the downstroke. In the subsequent mechanical arm 1 up process, the energy storage spring 41 rebounds, which can help the servo motor 3 to speed up and reduce the work, so as to reduce the power consumption and heat generation of the servo motor 3.

[0050] In addition, in order to prevent the mechanical arm 1 from uncontrollably turning down when the power is suddenly cut off, the servo motor 3 generally needs to be equipped with a brake module under the above working condition, and the motor shaft 31 is locked when the power is suddenly cut off. But the embodiment can also replace the brake module, when the power is cut off, the energy storage spring 41 will buffer the mechanical arm 1 turning down and push the mechanical arm 1 back to the set position and stop moving. Since the brake module is cancelled, the cost is reduced and the installation space is saved.

[0051] The energy storage return force disc 4 is provided with a shaft hole 44 for penetrating the rotating shaft 31, and the hydraulic mechanism includes an annular oil storage box 45 arranged outside the shaft hole 44. The oil storage box 45 is circumferentially arranged with three oil grooves 46 which are in communication with each other, and the oil grooves 46 extend outward along the energy storage return force disc 4. The outer end of each oil groove 46 is provided with a small piston rod 47, and each piston rod is connected with a sliding block 42. The outer gear ring 53 is circumferentially arranged with three push rods 54 corresponding to the sliding blocks 42. The oil storage box is also circumferentially arranged with three large piston rods 48 which move radially, and each large piston rod 48 is connected with a group of energy storage springs 41. Since the energy storage return force disc 4 is driven by the hydraulic mechanism, the hydraulic mechanism and the energy storage spring 41 play a double buffering role, avoiding the whistling or vibration of the servo motor 3 during the deceleration process after the push rod 54 contacts the sliding block 42. The oil groove 46 is also provided with a serpentine buffer section 461, which can further improve the buffering capacity. In addition, the three small piston rods 47 and the three large piston rods 48 can be regarded as six control points, the hydraulic mechanism structure is relatively simple, and the space occupied is small, which can avoid the energy storage return force disc 4 being too bulky.

[0052] In order to adapt to the installation space, the energy storage return plate 4 needs to reduce the thickness as much as possible, therefore, the selection and distribution of the energy storage spring 41 not only need to consider the energy storage capacity of the spring, but also need to consider its length and diameter. The annular spring is selected as the energy storage spring 41 in the embodiment, which is also called friction spring, and is composed of a plurality of inner conical surface and outer cylindrical surface washer-shaped spring steel and inner cylindrical surface and outer conical surface washer-shaped spring steel alternately stacked and combined, which not only has strong energy storage capacity, but also has small length change when deformed. The radial periphery of the oil storage box 45 is provided with an annular energy storage cavity 411, and six radially extending guide spokes 412 are arranged at equal angles in the energy storage cavity 411, and each guide spoke 412 is sleeved with an annular spring. The large piston rod 48 includes a rod body 481 and a top plate 482 arranged on both sides of the rod body 481, and the top plate 482 is arranged on one end of the two annular springs close to the shaft hole 44, and the top plate 482 is also provided with a perforation for penetrating the guide spoke 412. By increasing the number of annular springs, smaller diameter annular springs can be selected to reduce the impact on the thickness of the energy storage return plate 4. In addition, increasing the number of annular springs can also reduce the length required by each spring, which can effectively reduce the diameter of the energy storage return plate 4. The embodiment is provided with a plurality of push rods 54, a plurality of oil grooves 46 and a plurality of energy storage springs 41 arranged at equal angles, which can also disperse and evenly bear the force, and avoid the occurrence of sharp squeal or vibration of the servo motor 3.

[0053] The outer ring wall of the energy storage cavity 411 is provided with an electromagnetic lock 6 corresponding to the large piston rod 48, and the electromagnetic lock 6 is opposite to the radial outer end of the rod body 481, and the electromagnetic lock 6 is connected with the servo driver 2 through the control line. When the mechanical arm 1 is turned down, it will carry the workpiece load, and when it moves to the set lowest point, it will stop for a while to put down the workpiece, so the turning down process will be affected by the gravity and inertia of itself and the workpiece. After the mechanical arm 1 reaches the vicinity of the set lowest point, if the traditional servo system is used, the servo driver 2 needs to perform gain control to accurately stop at the set position, which is manifested as that the mechanical arm 1 will swing forward and backward several times with a small amplitude around the set position, and the distance from the set position will be gradually reduced, and finally stop at the set position. However, in the case of vertical turning and with load, the difficulty of gain adjustment will be increased, which will increase the power consumption and reduce the working efficiency of the mechanical arm 1. The embodiment can well solve the above problems. When the servo driver 2 detects the mechanical arm 1 adjacent to the set position through the encoder 33 in the servo motor 3, it sends a command to make the electromagnetic lock 6 energized, and after the electromagnetic lock 6 is energized, it attracts the large piston, so that the servo motor 3 does not need to adjust the position, and directly locks the mechanical arm 1. In addition, after the electromagnetic lock 6 attracts the large piston rod 48, it can limit the rebound of the energy storage spring 41, and by controlling the energization time of the electromagnetic lock 6, the hovering time of the mechanical arm 1 can be controlled, and the smooth putting down of the workpiece can be ensured.

[0054] When the product is adjusted by the pipeline, the position of the mechanical arm 1 picking up the workpiece and the position of the mechanical arm 1 placing the workpiece can be adjusted. To solve this problem, the arc-shaped sliding groove 43 is designed with a margin to ensure the stroke length of the push rod 54, allowing the mechanical arm 1 to be raised to the maximum angle of elevation. In addition, the energy storage return disc 4 is located between the servo motor 3 and the planetary gear disc 5, and the energy storage return disc 4 is provided with a circle of adjusting tooth ring 49 on the side opposite to the servo motor 3. The outer shell 32 of the servo motor 3 is provided with a tooth ring seat 321 matched with the adjusting tooth ring 49. After opening the transmission cover 7 outside the planetary gear, the position of the arc-shaped sliding groove 43 can be adjusted by rotating the energy storage return disc 4, so as to adjust the angle of rotation of the push rod 54 of the outer gear ring 53, and then realize the purpose of adjusting the maximum angle of depression of the mechanical arm 1. After adjustment, the energy storage return disc 4 and the outer shell 32 are closed, and the adjusting tooth ring 49 is engaged with the tooth ring seat 321. The inside of the transmission cover 7 is in meshing connection with the planetary gear disc 5, and the outside of the transmission cover 7 is connected with the mechanical arm 1 through the key groove. Not only is it used for protecting the energy storage return disc 4 and the planetary gear disc 5, but also is used for transmission between the mechanical arm 1.

[0055] In summary, the servo system with the energy storage return disc 4 replaces the motor reverse driving forced stop of the mechanical arm 1 by the energy storage return mode, and replaces the traditional brake module. The energy storage return disc 4 not only can effectively save energy and reduce motor heating, but also has the advantages of ultra-thin, small volume and light weight.

[0056] The application also provides a servo system control method, which controls the up-down reciprocating rotation of the mechanical arm 1 through the energy storage return type servo system according to any one of the technical solutions.

[0057] The energy storage return type servo system can be used for Figure 1The servo system shown on the mechanical arm 1 includes a servo driver 2 and a servo motor 3 connected by a control line, the servo motor 3 is fixedly installed on the base for driving the mechanical arm 1 to flip up and down, and the servo driver 2 is used to control the operation of the servo motor 3. One end of the servo motor 3 is provided with an energy storage return disc 4 and a planetary gear disc 5. The planetary gear disc 5 functions as a speed reducer and includes a sun gear 51, a planet gear 52 and an outer gear ring 53 connected in meshing, the sun gear 51 is connected with the rotating shaft 31 of the servo motor 3 through a key groove, and the outer gear ring 53 is in transmission connection with the mechanical arm 1. The energy storage return disc 4 is provided with an energy storage spring 41 and a sliding block 42 connected through a hydraulic mechanism. The outer gear ring 53 is provided with a push rod 54 rotating synchronously, the push rod 54 has the same movement radius as the sliding block 42, the energy storage return disc 4 is provided with an arc-shaped sliding groove 43, and the sliding block 42 and the push rod 54 are limited to rotate in the arc-shaped sliding groove 43. When the mechanical arm 1 is flipped down, the push rod 54 is free to rotate for a stroke and then contacts the sliding block 42 to rotate together, and the sliding block 42 compresses the energy storage spring 41 through the hydraulic mechanism to store energy; when the mechanical arm 1 is flipped up, the energy storage spring 41 rebounds to provide auxiliary power for the mechanical arm 1 to flip up, helping the servo motor 3 to jointly drive the mechanical arm 1 to flip up until the sliding block 42 is separated from the push rod 54.

[0058] The traditional servo system generally helps the mechanical arm 1 to reduce the angular velocity by providing reverse power to the servo motor 3 until the mechanical arm 1 is forced to stop, but this forced stopping method not only consumes a lot of power, but also the coil will inevitably heat up when the motor works. In the embodiment, the energy storage spring 41 is used to replace the motor reverse driving to force the mechanical arm 1 to stop by the energy storage return force when the mechanical arm 1 is flipped down, and the servo motor 3 does not work in the part of the down-flipping stroke, and in the subsequent up-flipping process of the mechanical arm 1, the energy storage spring 41 rebounds to help the servo motor 3 to speed up and reduce the work, thereby reducing the power consumption and heat generation of the servo motor 3.

[0059] In addition, in order to prevent the mechanical arm 1 from uncontrollably flipping down when the power is suddenly cut off, the servo motor 3 generally needs to be equipped with a brake module under the above working condition to lock the motor rotating shaft 31 when the power is suddenly cut off. However, the embodiment can also replace the brake module, and when the power is cut off, the energy storage spring 41 will buffer the mechanical arm 1 flipping down and push the mechanical arm 1 back to the set position and stop moving. Since the brake module is cancelled, the cost is reduced and the installation space is saved.

[0060] In this embodiment, the energy storage return plate 4 is provided with an axial hole 44 for passing the rotating shaft 31, and the hydraulic mechanism includes an annular oil storage box 45 arranged around the axial hole 44. The oil storage box 45 is circumferentially provided with three oil grooves 46 in equal angles and in communication with the oil storage box 45, and the oil grooves 46 extend outward along the energy storage return plate 4. The outer end of each oil groove 46 is provided with a small piston rod 47, each piston rod is connected with a sliding block 42, and the outer gear ring 53 is circumferentially provided with three push rods 54 in equal angles, each push rod 54 corresponds to a sliding block 42. The oil storage box is also circumferentially provided with three large piston rods 48 in radial movement in equal angles, and each large piston rod 48 is connected with a group of energy storage springs 41. Since the energy storage return plate 4 is driven by the hydraulic mechanism, the hydraulic mechanism and the energy storage spring 41 play a double buffering role, which can avoid the whistling or trembling of the servo motor 3 during the deceleration process after the push rod 54 contacts the sliding block 42. The oil groove 46 is also provided with a serpentine buffer section 461, which can further improve the buffering capacity. In addition, the three small piston rods 47 and the three large piston rods 48 can be regarded as six control points, the hydraulic mechanism structure is relatively simple, and the space occupied is small, which can avoid the energy storage return plate 4 being too bulky.

[0061] In order to adapt to the installation space, the energy storage return plate 4 needs to reduce the thickness as much as possible, therefore, the selection and distribution of the energy storage spring 41 not only need to consider the energy storage capacity of the spring, but also need to consider its length and diameter. In this embodiment, the annular spring is selected as the energy storage spring 41. The annular spring, also known as friction spring, is composed of a plurality of inner conical outer cylindrical gasket-shaped spring steels and inner cylindrical outer conical gasket-shaped spring steels alternately stacked and combined. It not only has strong energy storage capacity, but also has small length change when deformed. In this embodiment, the radial outer periphery of the oil storage box 45 is provided with an annular energy storage cavity 411, and the energy storage cavity 411 is circumferentially provided with six radial extending guide spokes 412. Each guide spoke 412 is sleeved with an annular spring. The large piston rod 48 includes a rod body 481 and a top plate 482 arranged on both sides of the rod body 481. The top plate 482 abuts against one end of the corresponding two annular springs close to the axial hole 44, and the top plate 482 is also provided with a through hole for passing through the guide spoke 412. By increasing the number of annular springs, smaller diameter annular springs can be selected to reduce the impact on the thickness of the energy storage return plate 4. In addition, increasing the number of annular springs can also reduce the length required by each spring, which can effectively reduce the diameter of the energy storage return plate 4. In this embodiment, the equal angle arrangement of multiple push rods 54, multiple oil grooves 46 and multiple energy storage springs 41 can also disperse and evenly distribute the force, so as to avoid the sharp whistling or trembling of the servo motor 3.

[0062] In this embodiment, the outer ring wall of the energy storage cavity 411 is provided with an electromagnetic lock 6 corresponding to the large piston rod 48. The electromagnetic lock 6 is opposite to the radial outer end of the rod body 481, and the electromagnetic lock 6 is connected with the servo driver 2 through a control line. When the mechanical arm 1 is lowered, it will carry the workpiece load and move to the set lowest point and stay for a short time to put down the workpiece. Therefore, the lowering process will be affected by the gravity and inertia of the mechanical arm 1 and the workpiece. After the mechanical arm 1 reaches the vicinity of the set lowest point, if the traditional servo system is used, the servo driver 2 needs to perform gain control to accurately stop at the set position. This is manifested as that the mechanical arm 1 will swing back and forth several times with a slight amplitude around the set position, gradually reducing the distance from the set position, and finally stopping at the set position. However, in the case of vertical flipping and with load, it will increase the difficulty of gain adjustment, resulting in increased power consumption and reduced working efficiency of the mechanical arm 1. The embodiment can well solve the above problems. When the servo driver 2 detects that the mechanical arm 1 is adjacent to the set position through the encoder 33 in the servo motor 3, it sends a command to energize the electromagnetic lock 6. After the electromagnetic lock 6 is energized, it attracts the large piston to make the servo motor 3 not need to adjust the position, and directly locks the mechanical arm 1. In addition, after the electromagnetic lock 6 attracts the large piston rod 48, it can limit the rebound of the energy storage spring 41. By controlling the energization time of the electromagnetic lock 6, the hovering time of the mechanical arm 1 can be controlled, and the smooth putting down of the workpiece can be ensured.

[0063] When the production line is adjusted, the position of the mechanical arm 1 picking up the workpiece and the position of the mechanical arm 1 placing the workpiece may be adjusted. To solve this problem, the arc-shaped sliding groove 43 is designed with a margin to ensure the stroke length of the push rod 54, allowing the mechanical arm 1 to be raised to the maximum angle of elevation. In addition, the energy storage return disc 4 is located between the servo motor 3 and the planetary gear disc 5. The energy storage return disc 4 is provided with a circle of adjustment tooth ring 49 on the side opposite to the servo motor 3. The outer shell 32 of the servo motor 3 is provided with a tooth ring seat 321 matched with the adjustment tooth ring 49. After the transmission cover 7 outside the planetary gear disc is opened, the position of the arc-shaped sliding groove 43 can be adjusted by rotating the energy storage return disc 4, so as to adjust the angle that the push rod 54 of the outer gear ring 53 can rotate, thereby achieving the purpose of adjusting the maximum angle of depression of the mechanical arm 1. After adjustment, the energy storage return disc 4 and the outer shell 32 are closed, and the adjustment tooth ring 49 is engaged with the tooth ring seat 321.

[0064] In summary, the servo system with the added energy storage return disc 4 uses the energy storage return force to replace the motor reverse driving to force stop the mechanical arm 1, and replaces the traditional brake module. The energy storage return disc 4 not only can effectively save energy and reduce motor heating, but also has the advantages of ultra-thin, small volume and light weight.

[0065] The servo system control method is as follows:

[0066] As shown in Figure 7 The flipping cycle of the mechanical arm 1 is divided into four strokes, including

[0067] Stroke 1, the mechanical arm 1 from the highest starting position A under the drive of the servo motor 3, the push rod 54 is free to rotate;

[0068] Stroke 2, when the mechanical arm 1 rotates an angle α, reaches the set position C, the push rod 54 contacts the slider 42, the servo motor 3 stops power supply, under the action of inertia and gravity of the mechanical arm 1, the slider 42 is pushed to rotate together, through the hydraulic mechanism transmission, the large piston rod 48 lifts the force storage spring to compress the force storage, until the mechanical arm 1 reaches the lowest point B;

[0069] Stroke 3, the servo motor 3 is re-powered to drive the mechanical arm 1 to rotate upward, and the force storage spring is stretched to recover, through the hydraulic mechanism to drive the slider 42 to rotate reversely, the slider 42 drives the push rod 54 to rotate the outer ring gear 53;

[0070] Stroke 4, the slider 42 and the push rod 54 are disengaged, the mechanical arm 1 continues to rotate upward under the drive of the servo motor 3 alone until it returns to the starting position A.

[0071] In the embodiment, when the mechanical arm 1 reaches the lowest point, the electromagnetic lock 6 is powered on and locked to the large piston rod 48, and the electromagnetic lock 6 is powered off after a preset value n seconds, and the servo motor 3 is re-powered. The value of the preset value n can be determined according to the specific scene.

[0072] In the embodiment, when the energy storage spring 41 is powered off, the mechanical arm 1 automatically rotates to the set position C under the action of the energy storage spring 41. The specific angle of the set position C is affected by the torque generated by the mass of the mechanical arm and the load, and is also affected by the compression amount of the energy storage spring after pressure, and in the field, the height of the base can also be adjusted. In short, the mechanical arm should be within the safe range when it is at the set position C.

[0073] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An energy-storing, return-type servo system, comprising a servo driver and a servo motor connected via control lines, characterized in that, One end of the servo motor is equipped with an energy storage return disk and a planetary gear disk; The energy storage return plate is equipped with an energy storage spring and a slider connected by a hydraulic mechanism; The planetary gear disk includes a sun gear, planet gears and an external gear ring that are meshed together. The shaft of the servo motor is connected to the sun gear through a keyway. The external gear ring is connected to the robotic arm for transmission. The external gear ring is provided with a synchronously rotating push rod. The push rod has the same radius of motion as the slider. When the robotic arm tilts down, the push rod rotates freely for a certain distance and then pushes the slider to compress the energy storage spring to store energy. When the robotic arm flips upward, the energy storage spring rebounds and provides auxiliary power for the robotic arm to flip upward; The energy storage return plate has a shaft hole in the middle for the shaft to pass through. The hydraulic mechanism includes an annular oil storage box around the shaft hole. The oil storage box has several oil grooves connected to itself arranged at equal angles around its circumference. The oil grooves extend outward along the energy storage return plate. Each oil tank has a small piston rod at its outer port, and each small piston rod is connected to a slider. The outer gear ring is provided with several push rods at equal angles, and the push rods correspond one-to-one with the sliders. The oil storage box is also provided with several large piston rods that move radially at equal angles around its circumference, and each large piston rod is connected to a set of energy storage springs. The oil storage box has an annular energy storage cavity on its radial periphery. The energy storage cavity has several radially extending guide spokes. Each guide spoke is fitted with an energy storage spring, which is an annular spring. The large piston rod includes a rod body and top plates disposed on both sides of the rod body. The top plates abut against one end of each energy storage spring in the corresponding group near the shaft hole. The top plates are also provided with through holes for the guide spokes to pass through. The outer ring wall of the energy storage chamber is provided with an electromagnetic lock that corresponds one-to-one with the large piston rod. The electromagnetic lock is directly opposite the radial outer end of the rod and is connected to the servo driver through a control line.

2. The energy storage and return-type servo system as described in claim 1, characterized in that, The energy storage return plate is located between the servo motor and the planetary gear disk. The energy storage return plate has an adjusting gear ring on the side opposite to the servo motor. The servo motor has a gear ring seat that matches the adjusting gear ring on the outer end face of the housing.

3. The energy storage and return-type servo system as described in claim 1, characterized in that, The oil tank is equipped with a serpentine buffer section.

4. The energy storage and return-type servo system as described in claim 1, characterized in that, The energy storage return plate is provided with an arc-shaped slide groove, and the slider and the push rod are restricted to rotate within the arc-shaped slide groove.

5. A servo system control method, characterized in that, The robotic arm is controlled to reciprocate up and down using the energy storage and return type servo system as described in any one of claims 1-4; The robotic arm's flipping cycle consists of four strokes: Stroke 1: The robotic arm accelerates downward from its starting position A at the highest point, driven by the servo motor, and the push rod rotates freely. In stroke 2, when the robotic arm rotates at an angle α, the push rod contacts the slider, the servo motor stops supplying power, and under the action of inertia and the weight of the robotic arm, it pushes the slider to rotate together. Through the hydraulic mechanism, the large piston rod pushes up the storage spring to compress and store power until the robotic arm reaches the lowest point B. In stroke 3, the servo motor is re-energized and rotates in the opposite direction to drive the robotic arm to flip up. At the same time, the storage spring extends and recovers, pushing the slider to rotate in the opposite direction through the hydraulic mechanism. The slider pushes the push rod to assist the rotation of the outer gear ring. In stroke 4, the slider disengages from the push rod, and the robotic arm continues to flip upwards under the independent drive of the servo motor until it returns to the starting position A.

6. The servo system control method as described in claim 5, characterized in that, When the robotic arm reaches the lowest point, the electromagnetic lock is energized and locks the large piston rod. After n seconds, the electromagnetic lock is de-energized, and the servo motor is re-energized.

7. The servo system control method as described in claim 6, characterized in that, When the energy storage return type servo system loses power, the robotic arm automatically rotates back to the set position C under the action of the energy storage spring.

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