Starting control method of electric device, electric turnover device and turnover conveying line

Abstract

The invention provides a starting control method of an electric device, an electric turnover device and a turnover conveying line. The electric device comprises a motor, a frequency converter and a band-type brake, in an initial state, the band-type brake locks an output shaft of the motor, and the starting control method comprises the steps that a starting instruction is received; controlling a band-type brake to be started according to the starting instruction; when the band-type brake is controlled to be started, the frequency converter is controlled to output alternating current of the first frequency so as to control the motor to continuously output torque in the preset direction. According to the embodiment of the invention, the starting time of the motor is shortened, the starting efficiency of the electric device is improved, and the motor is prevented from rotating reversely under the action of a load. And meanwhile, excessive mechanical wear can be avoided.

Description

Technical Field

[0001] This invention relates to the field of electric motor control technology, and in particular to a starting control method for an electric device, an electric flipping device, and a flipping conveyor line. Background Technology

[0002] In some applications, the output shaft of a motor needs to be locked when it is not running to prevent the motor from rotating, maintain the stability of the electric equipment, and ensure the safety of the production and transportation process. In this case, a holding brake is required to restrict the output shaft of the motor. For example, holding brakes are required in equipment such as elevators, tippers, gantry cranes, and quay cranes to keep the motor or load in a preset position and prevent safety accidents.

[0003] Existing brake systems typically utilize the electromagnetic induction of a coil (hereinafter referred to as the brake coil), combined with some mechanical structures, to restrict the output shaft of the motor. However, due to the limitations of the electromagnetic induction principle, the brake system requires a certain amount of time to switch from a locked state to an unlocked state, usually more than 10ms. This delay in the brake system affects the working efficiency of the electric equipment, necessitating coordination between the start-up time of the motor and the brake system to allow the brake system to establish a stable locking force or completely release the locking force.

[0004] On the other hand, the asynchrony between the electric motor and the brake can also cause wear on the output shafts of the brake and the electric motor, affecting the service life of the brake.

[0005] The content of the background section is merely the technology known to the inventor and does not necessarily represent the prior art in this field. Summary of the Invention

[0006] To address one or more deficiencies in the prior art, the present invention provides a starting control method for an electric device, the electric device comprising a motor, a frequency converter, and a holding brake, wherein, in an initial state, the holding brake locks the output shaft of the motor, and the starting control method includes:

[0007] Receive startup command;

[0008] According to the start command, the holding brake is unlocked;

[0009] While controlling the unlocking of the holding brake, the inverter is controlled to output AC power of the first frequency to control the motor to continuously output torque in a preset direction.

[0010] According to one aspect of the invention, wherein the locking force of the holding brake on the output shaft is reduced from a maximum value to a minimum value during a first duration, and the step of controlling the frequency converter to output AC power of a first frequency to the motor includes: controlling the frequency converter to output AC power of a first frequency during the first duration to prevent the motor from rotating in the opposite direction.

[0011] According to one aspect of the present invention, the start-up control method further includes:

[0012] During the first time period, the current output by the frequency converter is reduced.

[0013] After the first duration ends, the frequency converter outputs a constant current.

[0014] According to one aspect of the invention, the constant current is the operating current of the motor; during the first duration, the maximum value of the current output by the frequency converter is not greater than ten times the operating current of the motor.

[0015] According to one aspect of the invention, the invention further includes an electrically operated tilting device, the electrically operated tilting device comprising:

[0016] Electric motor;

[0017] A frequency converter, which is coupled to the motor and configured to control the starting of the motor;

[0018] A brake is provided, located at the output shaft of the motor, having a locked state and an unlocked state, and configured to switch controllably between the locked and unlocked states; in the locked state, the brake restricts the movement of the motor's output shaft by a locking force; in the unlocked state, the brake releases the locking force; and

[0019] The controller is signal-connected to the frequency converter;

[0020] The frequency converter is signal-connected to the holding brake and configured to execute the starting control method for the electric actuator as described above, and the controller is configured to issue a start command to the frequency converter; or

[0021] The holding brake is signal-connected to the controller or the frequency converter, and the controller is configured to execute the starting control method of the electric device as described above.

[0022] According to one aspect of the invention, the electric tilting device further includes:

[0023] The bearing part is fixedly or transmittedly connected to the output shaft of the motor. The bearing part rotates in a preset direction under the drive of the motor. When the motor is not started, the holding brake is configured to switch to a locked state to resist the load of the bearing part acting on the motor.

[0024] According to one aspect of the invention, after the controller receives the start command, during the first duration, the locking force of the holding brake acting on the output shaft of the motor and the torque output by the frequency converter controlling the motor work together to resist the load of the bearing part acting on the motor and prevent the motor from rotating in the reverse direction.

[0025] According to one aspect of the invention, the frequency converter is a vector control frequency converter; the brake includes a brake coil.

[0026] According to one aspect of the invention, the invention also includes a flipping conveyor line, the flipping conveyor line comprising:

[0027] A conveyor belt, which drives an object to move along the conveyor belt;

[0028] As described above, the electric flipping device is disposed within the conveyor belt. The electric flipping device is configured to enable the object to move along the direction of movement of the conveyor belt, or to flip the object so that the object is removed from the conveyor belt. The straight line direction of the rotation axis of the electric flipping device that flips the object is parallel to the direction of movement of the conveyor belt.

[0029] A control device is signal-connected to the conveyor belt and the electric tilting device, and is configured to control the conveyor belt to move or stop, and to control the electric tilting device to remain in place or tilt.

[0030] According to one aspect of the invention, the control device includes a code reader, the object having a corresponding code, the code reader being configured to acquire the code corresponding to the object, and to control the conveyor belt to move or stop based on the code information, and to control the electric flipping device to remain in place or flip over.

[0031] Compared with the prior art, embodiments of the present invention provide a starting control method for an electric device. Upon receiving a starting command, the brake and frequency converter start simultaneously, or the brake starts slightly earlier than the frequency converter. Before the locking force of the brake on the output shaft of the motor disappears, the frequency converter outputs AC power of a first frequency to control the output torque of the motor. By utilizing the delay time of the brake, the starting time of the motor is shortened, improving the starting efficiency of the electric device. Furthermore, utilizing the output torque of the motor can prevent the motor from rotating in the opposite direction under load. It also helps to synchronize the motor rotation and the unlocking of the brake, avoiding prolonged output by the motor during the brake unlocking process, which could lead to excessive mechanical wear.

[0032] The present invention also relates to an embodiment of an electric tilting device, wherein the aforementioned starting control method for an electric device is applied to control the starting of the motor in the electric tilting device.

[0033] The present invention also relates to a flipping conveyor line, which uses the aforementioned electric flipping device to sort items or change the direction of movement of items. Attached Figure Description

[0034] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0035] Figure 1 This is a flowchart illustrating the starting control method of the electric device in some embodiments of the present invention;

[0036] Figure 2 This is a flowchart illustrating a startup control method for frequency and current changes in a frequency converter, as shown in some embodiments of the present invention.

[0037] Figure 3A This is a schematic diagram illustrating the frequency change of the inverter over time in some embodiments of the present invention;

[0038] Figure 3B This is a schematic diagram illustrating the change of inverter current over time in some embodiments of the present invention;

[0039] Figure 3C This is a schematic diagram illustrating the change of the locking force of the holding brake on the output shaft over time in some embodiments of the present invention;

[0040] Figure 3D This is a schematic diagram illustrating the change of motor rotation speed over time in some embodiments of the present invention;

[0041] Figure 4 This is a structural block diagram of the electric tilting device in some embodiments of the present invention;

[0042] Figure 5 This is a structural block diagram of a flipping conveyor line in some embodiments of the present invention. Detailed Implementation

[0043] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0044] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly and specifically defined.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0047] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0048] The embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0049] Figure 1 The following illustrates a flowchart of a starting control method 100 for an electric device according to some embodiments of the present invention, used to control the starting process of the motor in the electric device. Figure 1 The starting control method 100 for the electric actuator is described.

[0050] The electric actuator in this embodiment includes a motor, a frequency converter, and a holding brake (e.g., Figure 4 The electric tilting device shown in the diagram includes a frequency converter configured to control a motor. In the initial state, the motor remains stationary and does not output anything, for example, it is in a stopped state. A brake is configured to lock the motor's output shaft. For example, in this embodiment, the motor is rotating, and the brake is configured to limit the rotation angle of the motor's output shaft, keeping it fixed. The brake includes, for example, a brake coil and a mechanical component whose movement is electromagnetically controlled by the brake coil. Electric devices can be used in elevators, tippers, cranes, and other equipment. Under load, the motor may rotate in the opposite direction, therefore a brake is usually required to lock the motor's output shaft. In subsequent embodiments of the invention, an electric tilting device will be used as an example for detailed explanation.

[0051] In the starting control method 100 of the electric actuator, such as Figure 1 As shown, in step S101, a start command is received. This start command can be manually input by the operator, for example, by sending a signal through an operation button, trigger, or human-machine interface. After parsing the signal, the start command is received. In other embodiments, the start command can also be received by an automatic control device or sensor device. For example, if the electric device is controlled by other equipment, it can transmit signals via wired or wireless means to receive the start command.

[0052] In step S102, the brake is unlocked according to the start command. The principle of the brake locking and unlocking the motor's output shaft typically involves using mechanical or electromagnetic devices to limit the output shaft's movement, controlled by electrical signals. Due to the working principle of the brake, upon receiving a signal, such as a start command, the brake cannot immediately release the locking force on the motor's output shaft; a certain amount of time is required. For ease of description, the time required for the brake's locking force on the output shaft to decrease from its maximum to its minimum value is set as the first duration. The maximum value of the brake's locking force on the motor's output shaft can represent the force applied to the output shaft by the brake in its initial state, while the minimum value can represent, for example, the situation where there is no force between the brake and the output shaft, such as no contact between the brake and the output shaft, where the locking force is 0. In different embodiments, the locking force of the brake on the output shaft can vary uniformly or non-uniformly. For example, in embodiments where the brake locks the output shaft via a pluggable mechanical component, the locking force of the brake on the output shaft may change abruptly. This invention does not limit this. The first duration may differ for brakes of different specifications, operating principles, and parameters.

[0053] In step S103, while controlling the unlocking of the holding brake, the inverter is controlled to output AC power of the first frequency to control the motor to continuously output torque in a preset direction.

[0054] Compared to the control method of directly outputting a fixed current to the motor, this embodiment uses a frequency converter to control the motor. As the output frequency and output current of the frequency converter change, the torque output by the motor changes accordingly. This provides higher accuracy and greater freedom in controlling the motor, and is beneficial for adjusting the synchronization between the motor and the holding brake.

[0055] In this embodiment, after receiving the start command, the brake is opened. Simultaneously or during the process of the brake opening (the process of reducing the locking force), the motor is started by the frequency converter. This can accurately control the motor start time and the torque output by the motor. It utilizes the first moment during the brake opening process, which is beneficial to improving the motor start efficiency.

[0056] In some existing control methods, upon receiving a start command, a large fixed current is input to the motor to generate a large torque. While this ensures the motor rotates when the locking force disappears, the continuous squeezing and friction between the motor's output shaft and the mechanical components in the brake during the reduction of the locking force leads to a rapid decrease in the brake's lifespan. In this embodiment, the torque output of the motor can be easily controlled via a frequency converter, preventing excessive mechanical squeezing between the motor's output shaft and the brake, thus extending the brake's lifespan.

[0057] On the other hand, during the opening of the holding brake, the locking force of the holding brake on the output shaft gradually decreases. At the same time, under the action of the load, the output shaft of the motor may slip or even reverse. In this embodiment, the frequency converter controls the motor to continuously output torque in a preset direction to overcome the tendency of the load to reverse the motor and keep the electric device stable.

[0058] Furthermore, according to a preferred embodiment of the present invention, during the first time period, the locking force of the brake on the output shaft gradually decreases, while the frequency converter controls the motor to output torque in a preset direction. The locking force and the torque output by the motor cooperate to prevent the motor from rotating in the opposite direction under the load. In practical applications, taking a tippler as an example, a tippler usually has a preset tipping direction to tilt the load on it to a preset position. However, the load may cause the motor to tend to rotate in the opposite direction, for example, the center of gravity of the load is distributed on the side of the tipping axis away from the preset tipping direction. During the process of the brake's locking force gradually decreasing, the motor may rotate in the opposite direction under the load. In this embodiment, during the process of the brake's locking force gradually decreasing, the frequency converter outputs AC power of the first frequency to control the motor to output torque in the preset direction, which, together with the not-yet-completely-disappeared locking force, resists the tendency of the motor to rotate in the opposite direction under the load. In some cases, the load can generate a tendency to make the motor rotate in the forward direction, that is, the effect of the load and the tendency of the motor to move are roughly the same. In this case, it is not necessary to restrict the output shaft of the motor or perform additional motion control.

[0059] Figure 2The flowchart of a starting control method 200 for an electric device according to some embodiments of the present invention is shown, wherein steps S202, S203 and S204 are substantially the same as steps S101, S102 and S103 in the starting control method 100 in the foregoing embodiments, and will not be described again here.

[0060] In some embodiments of the present invention, the starting control method 200 of the electric device includes S201, before receiving the starting command, controlling the frequency converter to remain in standby state, the initial frequency of the frequency converter is 0, controlling the motor not to output torque, and without considering the load, there is no relative motion tendency between the output shaft of the motor and the brake, which can reduce the friction between the output shaft and the brake and reduce mechanical wear.

[0061] The output torque of a motor is directly related to the input current. A frequency converter can control the output torque by changing the frequency and current of the input motor. In practical applications, upon receiving a start command, the frequency and current of the frequency converter are changed. In this embodiment, after receiving the start command, the output frequency (first frequency) of the frequency converter can be preset according to the characteristics of the brake, which helps improve the synchronization between the motor's output torque and the brake. Preferably, the moment when the frequency converter controls the motor to output maximum torque and the moment when the locking force of the brake on the output shaft disappears occur approximately simultaneously, further improving the starting efficiency of the electric device.

[0062] Generally, the higher the first frequency, the greater the peak torque output of the motor controlled by the frequency converter. Correspondingly, when the motor load is small, the first frequency can be appropriately reduced to reduce the peak torque output of the motor controlled by the frequency converter and improve the synchronization between the motor and the holding brake.

[0063] Figures 3A-3D The diagram illustrates how different parameters change over time. The following section combines... Figures 2-3D The different stages of the electric actuator startup process are explained. Figures 3A-3D In the diagram, the time t1 corresponding to the vertical dashed line on the left represents the time when the start command is received, and the time t2 corresponding to the vertical dashed line on the right represents the time when the locking force of the brake on the output shaft is reduced to a minimum value (e.g., 0). The duration between t1 and t2 is approximately equal to the first duration corresponding to the brake, which is used to represent the first duration in the embodiments of the present invention. Figures 3A-3D The slopes in the examples are for illustrative purposes only and do not specify the rate of change of the parameters over time.

[0064] In some embodiments, the output frequency of the inverter changes over time as follows: Figure 3AAs shown, before receiving the start command, the frequency converter remains in standby mode, does not output anything, and maintains an output frequency of 0. After receiving the start command, the frequency converter increases its output frequency to a first frequency. The frequency converter changes its output frequency quickly. In this embodiment, after receiving the start command, the frequency converter outputs a higher first frequency AC current, which is beneficial for controlling the motor start-up. In some specific embodiments of the present invention, the first frequency can be manually set according to the characteristics of the brake, such as the first duration corresponding to the brake. During the opening of the brake, the frequency converter's output frequency is gradually increased until the frequency converter's output frequency reaches the preset frequency. Figure 3A The plateau period of the output frequency shown can be preset according to the load, for example, the frequency at which the inverter controls the stable operation of the motor. In different embodiments, the rate of increase of the inverter's output frequency during the first time period is not limited to a constant speed. Figure 3A The oblique line with a fixed slope is merely an example and does not constitute a limitation on the present invention.

[0065] like Figure 2 As shown, the start-up control method 200 further includes steps S204 and S205. In step S204, during a first time period, the current output by the frequency converter is reduced. Figure 3B As shown, in some embodiments, before receiving a start command, the current output by the inverter to the motor can be 0, the motor does not generate torque, which can prevent the mechanical components of the motor and the holding brake from being squeezed, and can reduce energy consumption. After receiving the start command, the inverter's output frequency can quickly increase from 0 to the first frequency, but due to physical limitations, the current input to the motor cannot simultaneously reach its maximum value. Therefore, in Figure 3B In this process, the current output by the frequency converter is in a relatively short period of time (usually on the order of milliseconds). Figure 3B The horizontal axis in the figure (without a time limit) rises rapidly, and the duration of the rapid rise in the inverter output current is ignored in the subsequent analysis.

[0066] See Figure 3B and Figure 3C As the locking force decreases, the current output by the frequency converter gradually decreases. In some embodiments, the output current of the frequency converter gradually decreases. In some embodiments, the maximum value of the output current of the frequency converter is the current at which the motor operates stably. Figure 3BThe current value at time t2 is 5 to 7 times that of the motor. During the reduction of the locking force, the output current of the inverter decreases to the current at which the motor operates stably. By setting a suitable first frequency for the inverter, the output current of the inverter can be made close to the current at which the motor operates stably when the locking force is reduced to a minimum, thus achieving synchronization between the motor and the holding brake. In step S205, after the first duration ends, the inverter is controlled to output a constant current, which can be the operating current of the motor.

[0067] In a preferred embodiment of the present invention, the maximum value of the current output by the frequency converter is set to be no more than ten times the operating current of the motor, which helps to reduce the wear of the mechanical parts of the brake and extend the service life of the brake.

[0068] Figure 3D The diagram illustrates the change in motor speed over time. In some embodiments, as the locking force gradually decreases, the restraining effect of the brake on the output shaft decreases. When the locking force remains relatively high, the motor's output shaft remains stationary. When the locking force decreases to a certain level (related to the motor's output torque and load), it becomes insufficient to keep the output shaft fixed, and the motor begins to rotate. With further reduction in the locking force, the motor's rotational speed increases. When the locking force reaches its minimum value, the motor maintains a constant speed under the control of the frequency converter. In other embodiments, the motor's rotational speed can be varied when the locking force reaches its minimum value. For example, the motor can be controlled to rotate at varying speeds via a frequency converter, or the load's torque on the motor can change during rotation, causing a change in the motor's rotational speed. In this embodiment, the motor has already started before the locking force reaches its minimum value, which helps to further improve the motor's starting efficiency.

[0069] The present invention also relates to an electric tilting device 1, Figure 4 The structure of the electric tilting device 1 according to some embodiments of the present invention is shown below, in conjunction with... Figure 4 The electric tilting device 1 will be described.

[0070] like Figure 4 As shown, the electric tilting device 1 includes a motor 11, a frequency converter 12, a brake 13, and a controller 14. The electric tilting device 1 is driven by the motor 11 and can be used to tilt items by rotating at a certain angle.

[0071] In this embodiment, the frequency converter 12 is coupled to the motor 11 and configured to control the start of the motor 11. For example, the frequency converter 12 changes the output frequency, thereby changing the current input to the motor 11 and controlling the torque output by the motor 11. According to a preferred embodiment of the present invention, the frequency converter 12 is a vector control frequency converter, which is beneficial to improving the load capacity of the motor when it is moving at low speed.

[0072] The brake 13 is located at the output shaft 111 of the motor 11. For example, the brake 13 includes a mechanical component that can limit the output shaft 111 of the motor 11, preventing the output shaft 11 from moving. In this embodiment, the brake 13 has a locked state and an unlocked state, and is controlled (e.g., receives a preset control signal) to switch between the locked state and the unlocked state.

[0073] When the holding brake 13 is in the locked state, it exerts a locking force on the output shaft 111 of the motor 11, restricting the movement of the output shaft 111. When the holding brake 13 is in the unlocked state, it releases the locking force on the output shaft 111.

[0074] According to some embodiments of the present invention, such as Figure 4 As shown, the controller 14 is signal-connected to the frequency converter 12, and the brake 13 is also signal-connected to the frequency converter 12. In this embodiment, the frequency converter 12 is configured to execute the starting control method for the electric device as described in the previous embodiments. For example, the controller 14 can receive signals from the operator or other sensors. Upon receiving the signal, the controller 14 sends a start command to the frequency converter 12. After receiving the start command, the frequency converter 12 controls the brake 13 to open, switching it from a locked state to an unlocked state. Simultaneously with opening the brake 13, the frequency converter 12 outputs AC power at a first frequency, thereby controlling the motor to continuously output torque in a preset direction. In this embodiment, the number of signal communications and the amount of data between the controller 14 and the frequency converter 12 are small, and the requirements for communication commands and efficiency are low.

[0075] In other embodiments, the brake 13 is signal-connected to the controller 14 or the frequency converter 12. The controller 14 may be configured to execute the starting control method for the electric device as described in the foregoing embodiments. For example, the controller 14 receives a start command and, after receiving the start command, sends control signals to the brake 13 and the frequency converter 12, such as controlling the brake 13 to unlock and simultaneously controlling the frequency converter 12 to output AC power of a first frequency. In subsequent processes, the controller 14 controls the output frequency and output current of the frequency converter 12.

[0076] like Figure 4As shown, in some embodiments of the present invention, the electric tilting device 1 further includes a support portion 15. The support portion 15 is fixedly connected or driven by the output shaft 111 of the motor 11. When the output shaft 111 of the motor 11 rotates, it drives the support portion 15 to move. Specifically, in a preferred embodiment of the present invention, the support portion 15 includes a rotating shaft, which is fixed by a bearing. The output shaft 111 of the motor 11 is fixedly connected to the rotating shaft. When the output shaft 111 rotates, the support portion 15 rotates in a preset direction under the drive of the motor 11. In this embodiment, the support portion 15 can support an object. The object is placed or fixed on the support portion 15. The object may be, for example, a hopper or goods inside the hopper.

[0077] In this embodiment, when the motor 11 is not started, the holding brake 13 is in a locked state. The holding brake 13 is configured to resist the load exerted on the motor 11 by the bearing part 15. This is to prevent the motor 11 from rotating without receiving a start signal, thus affecting the normal operation of the electric tilting device 1.

[0078] According to a preferred embodiment of the present invention, after receiving a start command, the inverter 12 causes the motor 11 to output torque during a first period of time during which the locking force of the holding brake 13 on the output shaft 11 is reduced to a minimum value, so as to resist the load of the bearing part 15 acting on the motor 11 and prevent the motor 11 from rotating in the opposite direction.

[0079] According to a preferred embodiment of the present invention, the frequency converter 12 is a vector control frequency converter, which is beneficial to improve the ability of the motor 11 to drive the load at low speed. For example, when the frequency of the motor 11 is near or less than the slip frequency, the output torque of the motor 11 can be increased by using the vector control frequency converter to control the motor 11, thereby increasing the maximum load that can be driven.

[0080] The present invention also relates to a flipping conveyor line 10, Figure 5 The structure of the flip conveyor line 10 according to some embodiments of the present invention is shown below in conjunction with Figure 5 The flipping conveyor line 10 is described below.

[0081] The flip conveyor line 10 can be used to sort objects, for example, in the field of freight logistics, to sort objects into different areas according to preset rules or received signals, or to perform transportation reversal, dumping of goods, etc.

[0082] The flipping conveyor line 10 includes a conveyor belt 2, an electric flipping device 1 as described in the foregoing embodiments, and a control device 3. The conveyor belt 2 is configured to move objects along the conveyor belt 2, for example... Figure 5 As indicated by the arrow at the top center, conveyor belt 2 moves the object from left to right. In some embodiments, conveyor belt 2 can be as follows: Figure 5 The shown modular arrangement, for example including 2-1, 2-2, 2-3, and 2-4 spaced apart from each other, ensures that the spacing between adjacent conveyor belts 2 is sufficient to prevent objects from falling off. This facilitates the assembly of the extended conveyor belt 2 and allows for the installation of the electric tilting device 1 within the conveyor belt 2. Furthermore, according to different embodiments of the present invention... Figure 5 The conveyor belts 2-1, 2-2, 2-3, and 2-4 shown in the diagram can be individually controlled to start or stop, which can improve the accuracy of controlling the movement of objects.

[0083] The electric flipping device 1 is installed inside the conveyor belt 2. Specifically, the electric flipping device 1 is configured to enable the object to move along the direction of movement of the conveyor belt 2, or to flip the object so that the object leaves the conveyor belt 2. For example, multiple objects on the conveyor belt 2 are sorted, and some of the objects are transported outside the conveyor belt 2 according to preset sorting conditions.

[0084] For example, in some embodiments of the present invention, the conveyor belt 2 includes a driving roller and a driven roller. The driving roller is driven to rotate, and the object moves by friction generated by the pressure of the object acting on the conveyor belt 2. The driven roller provides support for the object and reduces the friction of the object moving along the conveyor belt 2. An electric flipping device 1 is disposed within the conveyor belt 2. For example, the conveyor belt 2 is interrupted in the middle, and the electric flipping device 1 is embedded in the movement path of the conveyor belt 2. Alternatively, the flipping conveyor line 10 includes multiple linearly arranged conveyor belts 2, and the electric flipping device 1 is embedded between the multiple conveyor belts 2. Further, the electric flipping device 1 may be provided with a driving roller and a driven roller. For example, the electric flipping device 1 includes a support part 15, which includes a driving roller and a driven roller.

[0085] In this embodiment, the linear direction of the rotation axis that drives the object to rotate, as described by the electric flipping device 1, is as follows: Figure 5 As shown by the dashed line, it is parallel to the direction of movement of conveyor belt 2. The electric flipping device 1 flips around the rotation axis to flip the object on the electric flipping device 1 to the outside of conveyor belt 2.

[0086] The control device 3 is signal-connected to the conveyor belt 2 and the electric tilting device 1, and is configured to control the movement or stopping of the conveyor belt 2, and to control the electric tilting device 1 to remain in place or tilt. For example, multiple objects that need to be sorted are placed on the conveyor belt 2 and move along the conveyor belt 2. When the objects move to the position of the electric tilting device 1, according to the sorting conditions or communication signals, the control device 3 controls the electric tilting device 1 to remain in place, and the objects continue to move along the direction of the conveyor belt 2, or the control device 3 controls the electric tilting device 1 to tilt, so that the objects are removed from the range of the conveyor belt 2.

[0087] According to a specific embodiment of the present invention, the control device 3 includes a barcode reader (not shown in the figure). The object has a corresponding code, for example, a code is pasted on the surface of the object. The barcode reader is configured to acquire the code corresponding to the object and, based on the code information, control the conveyor belt 2 to move or stop, and control the electric flipping device 1 to remain in place or flip over. For example, when the object moves to the position corresponding to the electric flipping device 1, the conveyor belt 2 is controlled to stop, such as the drive roller in the electric flipping device 1 stopping rotation. Based on the code information, the electric flipping device 1 is controlled to remain in place, and the conveyor belt 2 is controlled to move so that the object continues to move along the conveyor belt 2. Alternatively, the electric flipping device 1 can be controlled to flip over, tilting the object downwards, and transporting the object to different positions according to preset classification conditions to complete the sorting.

[0088] In other embodiments of the present invention, the control device 3 may also control the conveyor belt 2 and the electric flipping device 1 in other ways. For example, the control device 3 includes sensors to sort objects by using the weight, volume, color, shape characteristics, etc. of the objects at the corresponding positions of the electric flipping device 1 as sorting conditions.

[0089] Finally, it should be noted that the above descriptions are merely embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A starting control method of an electric device, the electric device comprising an electric motor, a frequency converter and a band brake, the band brake locking an output shaft of the electric motor in an initial state, the starting control method comprising: receiving a starting instruction; controlling the band brake to unlock according to the starting instruction; controlling the frequency converter to output alternating current of a first frequency to the electric motor to control the electric motor to continuously output torque in a preset direction while controlling the band brake to unlock.

2. The starting control method according to claim 1, wherein the locking force of the brake band to the output shaft is reduced from a maximum value to a minimum value within a first time length, and the step of the control frequency converter outputting the alternating current of the first frequency to the motor comprises: controlling the frequency converter to output alternating current of the first frequency to prevent the electric motor from reversing within the first time period. 3.The starting control method of claim 2, further comprising: controlling the frequency converter to output current of a decreasing magnitude within the first time period; and controlling the frequency converter to output constant magnitude current after the first time period. 4.The starting control method of claim 3, wherein the constant magnitude current is a working current of the electric motor, and a maximum value of the current output by the frequency converter within the first time period is not greater than ten times the working current of the electric motor. 5.An electric turnover device, comprising: an electric motor; a frequency converter coupled to the electric motor and configured to control starting of the electric motor; a band brake disposed at a position of an output shaft of the electric motor, the band brake having a locked state and an unlocked state and being configured to be controlled to switch between the locked state and the unlocked state, in the locked state, the band brake limiting movement of the output shaft of the electric motor by a locking force, in the unlocked state, the band brake releasing the locking force; and a controller in signal connection with the frequency converter; wherein the frequency converter is in signal connection with the band brake and is configured to be capable of performing the starting control method of the electric device according to any one of claims 1-4, the controller is configured to be capable of sending a starting instruction to the frequency converter; or the band brake is in signal connection with the controller or the frequency converter, and the controller is configured to be capable of performing the starting control method of the electric device according to any one of claims 1-4. 6.The electric turnover device of claim 5, further comprising: a load carrier fixedly connected or drivingly connected to the output shaft of the electric motor, the load carrier being driven to rotate in a preset direction by the electric motor; when the electric motor is not started, the band brake is configured to switch to the locked state to resist a load of the load carrier acting on the electric motor. 7.The electric turnover device of claim 6, wherein after the controller receives the starting instruction, within the first time period, the locking force of the band brake acting on the output shaft of the electric motor and the torque of the electric motor output by the frequency converter jointly act to resist the load of the load carrier acting on the electric motor to prevent the electric motor from reversing. 8.The electric turnover device of any one of claims 5-7, wherein the frequency converter is a vector control frequency converter, and the band brake comprises a band brake coil. ​ 9. A flip line, comprising: a conveyor belt configured to move an object along the conveyor belt; an electric flipper as claimed in any one of claims 5-8, disposed in the conveyor belt, the electric flipper configured to move the object along a direction of movement of the conveyor belt or to flip the object off the conveyor belt, the electric flipper flipping the object about an axis of rotation parallel to the direction of movement of the conveyor belt; a control device in signal connection with the conveyor belt and the electric flipper and configured to control the conveyor belt to move or stop and to control the electric flipper to remain in place or flip.

10. The flip line of claim 9, wherein the control device comprises a code reader, the object having a corresponding code, the code reader configured to obtain the corresponding code of the object and to control the conveyor belt to move or stop and to control the electric flipper to remain in place or flip based on the code information.

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