Setting method of hoist and hoist

Abstract

A method for setting up a winch includes an encoder that detects the rotation of a drive motor, and a load pulley that is rotated by driving the drive motor, thereby winding or unwinding a load chain to raise or lower a load. The method includes: a driving step in which the drive motor is driven at a fixed rotational speed while applying tension to the load chain; a storage step in which motor torque command values ​​for controlling the drive motor are stored in a storage unit corresponding to position information obtained from the encoder in the driving step; and a speed correction curve calculation step in which a speed correction curve for driving the drive motor is calculated based on the periodic variation of the motor torque command values ​​stored in the storage step.

Description

Technical Field

[0001] This invention relates to a method for setting up a winch and to a winch. Background Technology

[0002] Among the winches that raise or lower goods, there are electric chain hoists, such as those in Patent Document 1, which are equipped with servo motors. The load pulleys are rotated by the drive of the servo motors, thereby winding and unwinding the load chain.

[0003] [Existing Technical Documents]

[0004] [Patent Documents]

[0005] Patent Document 1: International Publication No. WO2021 / 079642 Summary of the Invention

[0006] (The problem that the invention aims to solve)

[0007] However, in the structure disclosed in Patent Document 1, the engagement between the load pulley and the load chain is approximately polygonal. Therefore, when winding and unwinding the load chain, the speed of the load chain changes due to the varying distance between the centerline of the hanging load chain and the rotation center of the load pulley. Furthermore, this speed variation and the mechanical structure of the electric chain hoist can sometimes cause resonance, resulting in even greater vibration.

[0008] However, adding a mechanical structure to prevent vibrations, including resonance, by suppressing speed variations as described above would result in increased size or cost, which is not ideal. Therefore, techniques for controlling and preventing the aforementioned vibrations during the initial setup before the winch leaves the factory (manufacturing stage) have been investigated. However, when preventing vibrations through control during the initial setup at the manufacturing stage, it is best to achieve high efficiency using simpler control methods.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a method for setting up a winch and a winch that can suppress the generation of vibration using simple control.

[0010] (A solution to the problem)

[0011] To address the aforementioned issues, according to a first aspect of the present invention, a method for setting up a winch is provided. This winch has an encoder that detects the rotation of a drive motor, and the load pulley is rotated by driving the drive motor, thereby causing the load chain to wind up or unwind, thus raising or lowering the cargo. The method for setting up the winch has the following features.

[0012] It includes: a driving step, which applies tension to the load chain while driving the drive motor at a fixed rotational speed; a storage step, which stores the motor torque command value used to control the drive motor and the position information obtained from the encoder in the driving step in a storage unit; and a speed correction curve calculation step, which calculates a speed correction curve to correct the speed command of the drive motor based on the periodic variation of the motor torque command value stored in the storage step.

[0013] Furthermore, in the above invention, it is preferable that the winch is equipped with a load sensor capable of detecting the load of goods suspended on the load chain, and the winch setting method includes a judgment step, in which, when the drive motor is controlled according to the speed command corrected by the speed correction curve calculated in the speed correction curve calculation step, the vibration of the goods is suppressed to not exceed a predetermined threshold based on the load detected by the load sensor; when the judgment step determines that the predetermined threshold is exceeded, the drive step, the storage step, and the speed correction curve calculation step are performed again.

[0014] Furthermore, in the above invention, it is preferable that, in the speed correction curve calculation step, the initial phase of the speed correction curve is calculated based on the position information in the maximum and / or minimum values ​​of the motor torque command value.

[0015] Furthermore, in the above invention, it is preferable that the speed correction curve is calculated as a sine wave in the speed correction curve calculation step.

[0016] In addition, in order to solve the above-mentioned problems, according to a second aspect of the present invention, a winch is provided which has an encoder for detecting the rotation of a drive motor, and the load pulley is rotated by driving the drive motor, thereby causing the load chain to be wound or unwound, thereby raising or lowering the goods. The winch has the following features.

[0017] It comprises: a storage unit that stores motor torque command values ​​used to control the drive motor in correspondence with position information obtained from the encoder during the drive of the drive motor; a speed correction curve calculation unit that calculates a speed correction curve to correct the speed command of the drive motor based on the periodic variation of the motor torque command values ​​stored in the storage unit; and a motor control unit that corrects the speed command based on the speed correction curve calculated by the speed correction curve calculation unit and controls the drive of the drive motor.

[0018] (Invention Effects)

[0019] According to the present invention, a method for setting up a winch and a winch that can suppress the generation of vibration using simple control are provided. Attached Figure Description

[0020] Figure 1 This is a side view showing the overall structure of a winch according to an embodiment of the present invention.

[0021] Figure 2 It means Figure 1 The diagram shows the control structure of the winch.

[0022] Figure 3 yes Figure 1 The diagram shows the load pulley and load chain of the winch, where (A) shows the state where the load chain is farthest from the center of rotation, and (B) and (C) show the state where the load chain is closest to the center of rotation.

[0023] Figure 4 This is an explanation Figure 1 The flowchart shows the setting method for the winch.

[0024] Figure 5 It means in Figure 1 The diagram shows the relationship between the torque command value when the drive motor is driven at a constant speed and the position information obtained from the encoder in the winch shown.

[0025] Figure 6 It means stored in Figure 1 The diagram shows the speed correction curve in the upper command unit of the winch.

[0026] Figure 7 It records from Figure 1 The graph shows the speed commands sent from the hoist's upper command unit to the speed control unit. The solid line represents the speed command corrected using the speed correction curve, while the dashed line records the speed command (reference speed command) that was not corrected using the speed correction curve.

[0027] Figure 8 It means in Figure 1 The diagram shows a winch before and after vibration suppression, with the solid line representing the speed command applied according to the present invention. Figure 7 The solid line represents the relationship between time and vibration when driving the drive motor, while the dashed line represents the relationship between speed command (in existing technology). Figure 7 The graph (with the dashed line in the middle) shows the relationship between the time and vibration when the drive motor is driven. Detailed Implementation

[0028] Hereinafter, a method for setting up a winch 10 according to an embodiment of the present invention and the winch 10 will be described with reference to the accompanying drawings.

[0029] <1. Regarding the structure of the winch 10>

[0030] Figure 1 This is a three-dimensional view showing the overall structure of the winch 10. Figure 2 This is a diagram showing the control structure of the winch 10. (Example) Figure 1 As shown, the winch 10, as a main structural element, includes a winch body 20, an upper hook 30, a cylinder operating device 130, a chain bucket 140 for holding the wound load chain C1, and a lower hook 150. That is, the winch 10 of this embodiment is an electric chain hoist capable of speed and torque control (current control) of the drive motor 40 via the operation of the cylinder operating device 130.

[0031] The winch body 20 can be suspended from a designated location such as a ceiling via an upper hook 30. Various structures are housed within the housing 21 of the winch body 20. Specifically, the housing 21 contains a drive motor 40, a reduction gear 50, a braking mechanism 60, a load sheave 70 for winding the load chain C1, a load sensor 80, a control unit 100, and a driver 110.

[0032] The drive motor 40 is an electric motor that provides driving force to drive the load pulley 70. In this embodiment, the drive motor 40 is a servo motor equipped with a detector (encoder 41) for reading magnetic pole information, which can detect or calculate speed and position information from the detector (encoder 41).

[0033] Additionally, the reduction mechanism 50 is the part that reduces the rotation of the drive motor 40 and transmits it to the load pulley 70 side, and it has a load gear (not shown in the figure). Furthermore, the braking mechanism 60 is the part that releases braking force using electromagnetic force when the drive motor 40 is operating, and generates braking force to hold the cargo P in the state where the drive motor 40 is not operating.

[0034] The load pulley 70 is the part that winds up or unwinds the load chain C1, and has multiple pockets 71 along its outer periphery for the metal rings of the load chain C1 to enter. Figure 3 Schematic diagrams of the load pulley 70 are shown in (A) to (C). Additionally, in Figure 3 In (A) to (C), regarding load chain C1, only its centerline is shown in a patterned map. For example... Figure 3 As shown in (A) to (C), the load pulley 70 is the part that transmits the driving force of the drive motor 40 to the load chain C1, and has a chain groove 71 on its outer periphery for transmitting the driving force to the load chain C1.

[0035] When the load chain C1 is in an untwisted state, the even-numbered metal rings are perpendicular to the odd-numbered metal rings. Therefore, the load pulley 70 has chain grooves with longitudinal and transverse grooves. Thus, in a generally schematic representation of the load pulley 70, two different octagonal shapes—one formed by connecting the center line of the load chain C1 engaging with the longitudinal groove, and the other by connecting the center line of the load chain C1 engaging with the transverse groove—are overlapped to form a sixteen-sided shape with the intersection of the sides as vertices. However, in… Figure 3 Of (A) to (C), based on the following... Figure 5 The insights gained from the measured values ​​of the torque command shown in the figure allow the load pulley 70 to be modeled as a regular octagon with the pitch length L of the two metal ring sections (one odd-numbered and one even-numbered) of the load chain C1 as one side.

[0036] Virtual bending points 72, where the load chain C1 bends upon engaging with the load pulley 70, exist between adjacent chain grooves 71 of the load pulley 70. The location of the bending points 72 varies depending on the shape of the load chain C1, its engagement position relative to the load pulley 70, and the tilting motion of the winch 10 during operation. Furthermore, it is difficult to assemble the load pulley 70 in a way that matches its positional relationship (phase) with the stator (not shown) of the drive motor 40. Additionally, the general shape of the load pulley 70 is not limited to an octagon; a polygon with fewer angles can be used to reduce the size of the winch, while a polygon with more angles can be used to reduce vibration. Furthermore, the chain grooves 71 can also be formed by locking teeth.

[0037] As described above, the meshing relationship between the load pulley 70 and the load chain C1 can be represented by a regular polygon with a virtual bending point 72 as its vertex. Figure 3 As shown in (A), when the line connecting the center O1 and the bending point 72 of the load pulley 70 is parallel to the horizontal line H, the load chain C1 is located at its furthest point from the center O1. Furthermore, in this state, the virtual drooping line from which the load chain C1 leaves the load sheave 70 and is suspended at the point of application is furthest from the center O1. Additionally, the bending point 72 of the load chain C1 relative to the point where it engages or disengages from the load pulley 70 corresponds to the point of application of the force. Furthermore, the aforementioned drooping line (load chain C1) is also the line of action of the load pulley 70 applying a winding force to the hanging load chain C1. In the following explanation, this drooping line will also be referred to as drooping line C1. Furthermore, the distance between the drooping line C1 and the center O1 of the load pulley 70 is referred to as the arm length A related to the torque. Therefore, as... Figure 3As shown in (A), the arm length A is at its maximum when the bending point 72, which serves as the point of application of the force, is located on the horizontal line H. The plumb line C1 is not limited to a vertical line; it coincides with the line of action of the force acting on the lower end of the load chain C1. In this case, the horizontal line H can also be described as a perpendicular line H drawn from the center O1 to the plumb line C1, which serves as the line of action.

[0038] In addition, when the arm length A is at its maximum, the speed of the load chain C1 is at its maximum relative to the rotation of the load pulley 70, and the motor torque of the drive motor 40 is also at its maximum.

[0039] On the other hand, such as Figure 3 As shown in (B) and (C), when the intersection of the line connecting adjacent bending points 72 and the horizontal line H is the midpoint of the adjacent bending points 72, the load chain C1 is located closest to the center O1. That is, the drooping line C1 is in the state closest to the center O1 of the load pulley 70, and the arm length A is at its minimum. Furthermore, in the state where the arm length A is at its minimum, the speed of the load chain C1 relative to the rotation of the load pulley 70 is at its minimum, and the motor torque of the drive motor 40 is also at its minimum. Additionally, in Figure 3 In this process, the arm length A is calculated using Equation 1 below. Here, A0 is the distance from the center O1 of the load pulley 70 to the bending point 72.

[0040] A = A0cosθ…(Equation 1)

[0041] As described above, when engaged with the load pulley 70, the position relative to the point of action of the load chain C1 changes. Therefore, even if the drive motor 40 rotates at a constant speed, the speed of the load chain C1 changes, and similarly, the motor torque of the drive motor 40 also changes. Furthermore, the pitch length L of the two (one odd-numbered and one even-numbered) metal rings (approximately oblong links) of the load chain C1 is... Figure 2 The load chain C1 shown has the same dimension L. The pitch circle radius Rp of the load pulley 70 can be expressed as Rp = n·L / 2π. n represents the angle of the modeled load pulley 70. Figure 3 In the case of the octagon shown, Rp = 4L / π. The average speed (reference speed) Va of the lower hook 150 when the load pulley 70 rotates at a rotational speed ω can be expressed as Va = n·L·ω = 2π·Rp·ω.

[0042] Returning to the description of the various structures of the winch 10, the load sensor 80 is a load sensor that measures the load applied to the upper hook 30. That is, the load sensor 80 is a sensor that measures or detects the total load of the winch body 20, the load of the load chain C1 (the portion not touching the ground, etc.), and the load of the cargo P. By subtracting the body's own weight, etc., from the total load measured or detected by the load sensor 80, the load applied to the load pulley 70 via the load chain C1 can be detected (calculated). The load sensor 80 is, for example, mounted on a mounting shaft used to mount the upper hook 30 to the winch body 20. Furthermore, the load sensor 80 corresponds to a load measuring unit.

[0043] As the load sensor 80, a load cell equipped with a strain gauge can be used. Regarding the placement of the load sensor 80, in addition to the above, it can be any location capable of detecting or measuring the load applied to the load pulley 70 by the load chain C1 suspending the cargo P, such as between the upper hook 30 and a pulley (not shown), between the lower hook 150 and the cargo P, or between the end of the load chain C1 and the lower hook 150. Furthermore, in addition to a load sensor, a crane scale or similar device can also be used as the load sensor 80. Figure 8 As shown, it is necessary to have the accuracy and responsiveness to be used in measurements of dynamic load variations.

[0044] Furthermore, the control unit 100 sends prescribed control commands to the driver 110, which will be described later. Specifically, the control unit 100 is the part that provides command values ​​such as position, speed, and torque. Examples of control units 100 include computers or integrated circuits that have a CPU (Central Processing Unit), a memory 101 (RAM (Random Access Memory), ROM (Read Only Memory), internal memory, external memory, etc.), and input / output interfaces.

[0045] Furthermore, in the control unit 100, a specified program or data stored in, for example, memory 101 is read in, and the control unit 100 cooperates with the hardware provided by the control unit 100 to functionally implement the host instruction unit 102, speed control unit 103, current control unit 104, and judgment unit 105.

[0046] The memory 101 can store position information (the rotation angle (position) of the drive motor 40 from the origin) obtained from the encoder 41. In addition, the memory 101 stores a prescribed program for controlling the drive motor 40, or various control-related data.

[0047] Furthermore, the upper-level command unit 102 is the part that sends speed commands related to the target speed or position commands related to the target position to the speed control unit 103. Additionally, the upper-level command unit 102 calculates the speed correction curve (function) as described later and stores this speed correction curve (the function and parameters for calculating the speed correction curve) in the memory 101. Moreover, based on the operation commands from the cylinder operating device 130 and the speed correction curve (the function and parameters for calculating the speed correction curve) read from the memory 101, the upper-level command unit 102 sends speed commands corresponding to the rotation angle (position) information obtained from the encoder 41 to the speed control unit 103.

[0048] Furthermore, the speed control unit 103 is the part that performs calculations to control the drive of the drive motor 40 based on the speed command sent from the upper command unit 102. Specifically, in the speed controller 103, based on the speed command as the target speed and the speed information based on the rotation angle (position) obtained from the encoder 41, it performs, for example, proportional control (P control), integral control (I control), and derivative control (D control) in PID control.

[0049] In addition, the current control unit 104 is the part that outputs motor torque command value (current control value) to the driver 110 based on the calculation value in the speed control unit 103.

[0050] Furthermore, when the determination unit 105 controls the drive motor 40 according to the speed command corrected by the speed correction curve, it determines whether the vibration of the cargo P is suppressed to not exceed a predetermined threshold based on the load detection of the load sensor 80. The determination unit 105 corresponds to a determination unit.

[0051] Additionally, the driver 110 receives motor torque command values ​​(current control values) and speed command values ​​from the current control unit 104, and supplies power to the drive motor 40 based on the drive command values. Thus, the drive motor 40 is driven using the controlled power. Furthermore, the control unit 100 and the driver 110 correspond to the motor control unit. Additionally, in Figure 2In this configuration, the control unit 100 includes a speed control unit 103 and a current control unit 104, and outputs speed commands to the driver 110. However, the driver 110 may also be configured to include both a speed control unit and a current control unit. Furthermore, the upper-level command unit 102 corresponds to the speed correction curve calculation unit, but the control unit 100 may also correspond to the speed correction curve calculation unit.

[0052] Here, from Figure 2 As clearly understood, the control unit 100 and the driver 110 perform feedback control by using speed information based on the rotation angle (position) obtained from the encoder 41 to make the drive motor 40 follow the speed commanded by the speed command. Thus, the drive motor 40 can follow the speed commanded by the speed command. Furthermore, the encoder 41 outputs pulse signals that accompany the rotation of the motor, and the control unit 100 converts these pulse signals into speed information or position information, which is then used in the feedback of speed control or position control.

[0053] Additionally, the cylinder operating device 130 is an operating device operated by the operator while holding it in their hand, and it is connected to the lower end of the load chain C1. The cylinder operating device 130 has an operating switch 131 for the operator to input operating commands, which can switch the operating mode of the winch 10, and can input commands such as the rotation direction of the drive motor 40 (winding or unwinding commands), speed commands, and emergency stop signals. Furthermore, a lower hook 150 for hooking the cargo P is connected to the cylinder operating device 130. Alternatively, instead of the operating switch 131 of the cylinder operating device 130, an operating device suspended by a wire rope from the winch body 20 of the winch 10 (pendant switch) can be used, or a wireless remote control device can be used.

[0054] Additionally, the chain drum 140 is the portion that houses the load chain C1, which is located on the unloaded side (already wound) opposite to the lower hook 150, separated by the load pulley 70. The lower hook 150 is the portion that holds the cargo.

[0055] <Instructions for setting up winch 10>

[0056] Next, according to Figure 4 The flowchart below describes the setting method for the winch 10 with the structure described above. Furthermore, the setting method for the winch 10 described below relates to the initial setting of the winch 10, but can also be applied to other situations besides the initial setting (such as setting changes during use of the winch 10 or settings during repairs).

[0057] Step S1: Descend to the designated position

[0058] First, the lower hook 150, which has risen to the origin position, is lowered to a predetermined position. At this time, the upper command unit 102 of the control unit 100 outputs a position command to the speed control unit 103 for lowering to the predetermined position. Based on this output, the speed control unit 103 outputs a drive command to the driver 110 based on the rotation angle (position) information obtained from the encoder 41, controlling the drive motor 40 to lower the lower hook 150 to the predetermined position. Regarding the lowering command to the predetermined position, it is preferable to use a lowering amount predetermined by the control unit 100 as described above, but it can also be configured so that the lowering operation is performed by an operator using the operation switch unit 131.

[0059] Furthermore, the aforementioned origin refers to the reference position when the lower hook 150 is raised, specifically, it corresponds to the position where the upper limit switch (not shown) located at the lower part of the winch body 20 is pressed. Using this origin as a reference, the current position of the lower hook 150 (the pull-out length of the load chain C1) can be calculated based on the position information (rotation angle of the drive motor 40) obtained from the encoder 41. As described above, the origin is preferably a position (upper limit position) in the winch 10 where it will not be further wound up (raised) mechanically or controllably.

[0060] Furthermore, after descending to the designated position, a load P of a specified weight is suspended from the lower hook 150. The load P of this specified weight can be a load with a weight sufficiently below the rated load level, and preferably, tension is applied to the hanging load chain C1 to ensure stable engagement between the load pulley 70 and the load chain C1.

[0061] Step S2: Constant speed drive of drive motor 40 (corresponding to the drive step)

[0062] Next, the control unit 100 controls the drive motor 40 to drive it in the rolling direction to lift the goods. Specifically, the upper command unit 102 of the control unit 100 outputs a speed command to the speed control unit 103 to drive the drive motor 40 at a certain microspeed. Based on this speed command, the speed control unit 103 performs calculations, and further, based on the calculation results, the current control unit 104 outputs a specified motor torque command value (current control value) to the driver 110. At this time, feedback control following the speed command (target speed) is performed by supplying the speed information of the drive motor 40 based on the rotation angle (position) obtained from the encoder 41 to the speed control unit 103. The speed command is set to the rotational speed of the drive motor 40, but it can also be the speed of the lower hook 150 calculated based on the pitch circle diameter of the load pulley 70 and the reduction ratio of the reduction mechanism 50.

[0063] Step S3: Store the position information and motor torque command obtained from the encoder (corresponding to the storage step)

[0064] Furthermore, the position information obtained from the encoder 41 in step S2 above and the motor torque command value (current control value) of the drive motor 40 are stored in memory 101 in association. When the drive motor 40 is controlled by feedback as described above to drive at a constant speed, when the load on the drive motor 40 changes, the motor torque command value (current control value) provided to the drive motor 40 changes in order to maintain the rotation of the drive motor 40 at a constant speed. This changed motor torque command value is stored in memory 101 in association with the position information obtained from the encoder 41.

[0065] Furthermore, the position information obtained from encoder 41 corresponds to the number of rotations or rotation angle of the rotor of drive motor 40 (not shown). This information is intended to be converted into the pull-out length of load chain C1 or the position information of lower hook 150. The converted value is stored in memory 101 in association with the motor torque command value. Specifically, control unit 100 converts the pulse signals from encoder 41 into the rotation angle of drive motor 40 (rotation angle from the origin) as position information. In addition, regarding this position information based on encoder 41, considering the reduction ratio, the shape of load pulley 70 and the metal ring constituting load chain C1, the installation position and shape of upper limit switch, and the shape of lower hook, etc., it can be converted into the pull-out length of load chain C1 or the position information of lower hook. In addition, in step S3, the pull-out length of load chain C1 is calculated based on the pitch circle of load pulley 70. The pitch circle of load pulley 70 is a virtual circle whose circumference is the length of load chain C1 wound up when load pulley 70 rotates one revolution.

[0066] Next, the variation in the load torque applied to the drive motor 40 will be explained. For example... Figure 3 As shown in (A), when the vertical line C1, which serves as the line of action, is furthest from the center O1 of the load pulley 70, the load torque applied to the drive motor 40 is at its maximum, and the motor torque command value given to the drive motor 40 is at its maximum.

[0067] On the contrary, such as Figure 3 As shown in (B) and (C), when the vertical line C1, which serves as the line of action, is closest to the center O1 of the load pulley 70, the load torque applied to the drive motor 40 is the minimum, and the motor torque command value given to the drive motor 40 is the minimum.

[0068] As described above, by measuring the motor torque command value (motor torque), the variation of the load torque applied to the load pulley 70 engaged with the load chain C1 can be determined. It is known that the load pulley 70 varies periodically depending on its engagement position with the load chain C1, which is the main reason for the variation in the winding speed of the load chain C1 (the moving speed of the lower hook 150). Therefore, by storing the motor torque command value and the position information obtained from the encoder 41 in association in the memory 101, the engagement position relationship between the load pulley 70 and the load chain C1 can be controlled in association with the position information obtained from the encoder 41 used in the control of the drive motor 40, which is a servo motor, without being affected by external factors such as the tilting of the winch 10.

[0069] For example, in Figure 5 In the curve diagram shown, the position where the motor torque command value is at its maximum Tmax is as follows: Figure 3 This corresponds to the maximum arm length A as shown in (A). Additionally, in Figure 5 In the text, the position where the motor torque command value is the minimum value Tmin is located, and as shown... Figure 3 The minimum arm length A corresponds to the case shown in (B) and (C).

[0070] in addition, Figure 5 It means to Figure 3 The graph shown depicts the relationship between the motor torque command value obtained by driving the modeled load pulley 70 at a certain microspeed in the winding direction and the position obtained from the encoder 41. In this graph, the thin line represents the motor torque command value stored in the memory 101 in association with the position information, and the thick line represents the value obtained by smoothing the motor torque command value, which varies slightly due to the meshing of gears (not shown) in the reduction mechanism 50, using a predetermined method such as moving average. Furthermore, in Figure 5 In the figure, the positional relationship is such that as the load chain C1 moves from the left to the right of the curve, the length of the pullout of the load pulley 70 decreases.

[0071] exist Figure 5 The graph shows the positions of two maxima, Tmax, representing the motor torque command value, and two minima, Tmin. Figure 5 In this context, the interval between positions representing two adjacent maxima or two adjacent minima can be considered as the period of the fluctuating waveform. Furthermore, based on the reduction ratio relationship of the reduction mechanism 50 connecting the drive motor 40 and the load pulley 70, it was reaffirmed that: from Figure 5The obtained period length corresponds to the length L of the two adjacent metal rings (longitudinal and transverse links) that constitute the load chain C1. Therefore, it is confirmed that compared to controlling vibration suppression by modeling the load pulley 70 as a polygon (hexagonal in the embodiment) with the metal rings of the longitudinal and transverse links as sides, it is preferable to use a model with the length L of the two metal rings (longitudinal and transverse links) as sides for control. Furthermore, since the number of metal rings constituting the load chain C1 wound in one turn in the load pulley 70 is fixed, the phase of the changing waveform at any position from the origin can also be calculated based on this data.

[0072] Step S4: Calculation of the speed correction curve (corresponding to the speed correction curve calculation step)

[0073] Next, a speed correction curve (function) for generating a speed command to suppress speed variations in the lower hook 150 is calculated. As described above, the chain groove 71 of the load pulley 70 includes multiple chain grooves, each consisting of a longitudinal groove and a transverse groove. The length of the load chain C1 wound up per revolution of the load pulley 70 can be determined by the number of chain grooves 71 and the shape and size of the metal rings (longitudinal and transverse links) constituting the load chain C1. Furthermore, the positional relationship between the longitudinal and transverse links and the load pulley 70, which are grouped together, can be made approximately a regular polygon. In this case, the length of the longitudinal and transverse links as a group ( Figure 2 The dimension L of the load chain C1 shown is a regular polygon whose length is the length of one side of the regular polygon. Figure 3 The center is a regular octagon.

[0074] When calculating the speed correction curve, firstly, based on the relationship between the position information obtained from the encoder 41 and the motor torque command value stored in step S3, the phase of the speed variation period and the variation period in the position information are confirmed. At the position where the motor torque value represents a maximum value, the winding speed also becomes a maximum value; conversely, at the position where the motor torque value represents a minimum value, the winding speed also becomes a minimum value.

[0075] Figure 6 The diagram shows a speed correction curve, which converts the speed variation component provided to the speed control unit 103 into a sinusoidal waveform to suppress speed variations in the lower hook 150. Regarding the speed correction curve, to make... Figure 5The sinusoidal waveform is generated by aligning the phases of the sine wave, either by aligning the position of the minimum value representing the motor torque command value with the position of the maximum value representing the speed correction curve, or by aligning the position of the maximum value representing the motor torque command value with the position of the minimum value representing the speed correction curve. Thus, a speed command y for reducing speed variation can be generated, and it can be expressed as shown in Equation 2 below, where the speed variation is the speed variation generated when the load chain C1 is wound up using the load pulley 70.

[0076] y=s[1+k·sin{(2π / L)(xd)}]…(Formula 2)

[0077] Here, the equation k·sin{(2π / L)(xd)} is the velocity variation component assigned to suppress the velocity variation of the lower hook 150, which corresponds to the velocity correction curve (function).

[0078] Here, in Equation 2 above, the symbols are as follows.

[0079] s: reference speed

[0080] k: coefficient of variation

[0081] L: Long cycle

[0082] x: Distance from the origin (variable)

[0083] d: Initial phase

[0084] The reference speed s is the speed command generated corresponding to the operation command of the cylinder operating device 130 before calibration, and is the speed generated based on the pitch circle of the load pulley 70. The variation coefficient k is calculated based on the variation of the arm length A. Additionally, the cycle length L is the length of the two metal rings (longitudinal and transverse links) constituting the load chain C1. The distance x from the origin is the distance calculated based on the product of the number of rotations of the encoder 41 accumulated from the origin (corresponding to the rotation angle of the drive motor 40) and the circumference of the pitch circle of the load pulley 70, multiplied by the reduction ratio; it can be considered as the pull-out length of the load chain C1. The initial phase d is... Figure 6 The phase shown, based on the position information of encoder 41, represents the meshing relationship between the load pulley 70 and the load chain C1 at the origin. Regarding the speed correction curve, it is based on... Figure 5The torque command value of the motor shown is generated from a set of positions of any two adjacent maximum or minimum values, but it can also be generated from multiple sets through statistical processing. Regarding the variation coefficient k, it can be set as k = (A0 - Rp) / Rp, based on the relationship between the radius Rp of the pitch circle of the load pulley 70 and the maximum value A0 of the arm length A related to the torque of the load pulley 70. This value can be determined by repeated vibration measurements. The period length L, the distance x from the origin, and the initial phase d are determined based on the cumulative value of the pulse signal of the encoder 41. Therefore, it can be represented by the number of pulses, or the pulse signal of the encoder 41 can be converted and represented by the rotation angle or rotation number of the drive motor 40. The product of the reference speed s and the variation coefficient k becomes the amplitude a of the periodic variation component of the corrected speed command, but the variation coefficient k can also be calculated after determining the amplitude a.

[0085] In Equation 2 above, the distance x from the origin is the virtual distance when the load pulley 70 is assumed to be circular as described above, and it is expressed by the following formula.

[0086] x = n·L·N…(Equation 3)

[0087] n: The angle of the modeled load pulley

[0088] n·L: Equivalent to the circumference of the pitch circle of the load pulley.

[0089] N: The number of rotations of the load pulley starting from the origin.

[0090] The distance x from the origin, calculated based on the pitch circle of the load pulley 70, is different from the actual pull-out length of the load chain C1. However, by integrating the speed command y generated using (Equation 2), the pull-out length of the load chain C1 or the position of the lower hook 150, which takes into account the meshing position relationship between the load pulley 70 and the load chain C1, can be accurately calculated.

[0091] When the drive motor 40 is controlled by the speed command obtained from Equation 2, the drive motor 40 does not drive at a constant speed, but the rotation speed varies periodically. However, the speed variation caused by the engagement of the load pulley 70 and the load chain C1 is suppressed when the lower hook 150 and the cargo P rise.

[0092] Figure 7 The graph shown records the speed command calculated in this way. Figure 7 In the diagram, the solid line represents the speed command corrected using the speed correction curve, while the dashed line represents the speed command (reference speed command) in the prior art that is not corrected using the speed correction curve.

[0093] Specifically, it becomes a graph that records the speed commands sent from the upper command unit 102 to the speed control unit 103 when the cargo P is suspended on the lower hook 150 and a high-speed winding command is input at a predetermined time through the operation switch unit 131, with and without speed correction (dashed line).

[0094] In addition, the calculated speed correction curve is stored in memory 101 as a function and its constants.

[0095] Step S5: Determining whether vibration is suppressed (corresponding to the judgment step)

[0096] Next, when driving the drive motor 40 according to the speed command y generated using the speed correction curve obtained in step S4, it is determined whether the vibration in the lower hook 150 is suppressed. Then, for example, if it is confirmed that the vibration is suppressed to below the specified vibration threshold ("yes"), it is determined that the calculated speed correction curve is correct, and the initial setting of the winch 10 used to obtain the speed correction curve ends. Conversely, if it is confirmed that the vibration exceeds the specified vibration threshold ("no"), steps S1 to S5 are repeated. Alternatively, it can be configured to change the value of the variation coefficient k in the speed correction curve (function) generated in step S4, and repeatedly perform the next step S5, thereby determining the optimal variation coefficient k.

[0097] in addition, Figure 8 The image shows an example before vibration suppression and an example after vibration suppression. Figure 8 In the graph, the solid line represents the relationship between the time when the drive motor 40 is driven by the speed command after correction using the speed correction curve calculated in step S4 and the vibration-based load. The dashed line represents the relationship between the time when the drive motor 40 is driven by the normal speed control based on the reference speed S, instead of the speed command being corrected using the speed correction curve calculated in step S4, and the vibration-based load.

[0098] In Figure 8 In the curve graph, the vibration components (load during winding operation: dynamic load - load before operation: static load) were calculated and recorded based on the load information detected by the load sensor 80 when driven by their respective speed commands.

[0099] exist Figure 8In the curve diagram shown, when the drive motor 40 is driven according to the corrected speed command shown by the solid line, compared to the case where the drive motor 40 is driven by the normal speed control based on the reference speed s shown by the dashed line, the vibration generated in the lower hook 150 when the load pulley 70 is rotated by the drive motor 40 is suppressed. That is, by controlling the drive of the drive motor 40 according to the speed command calculated using the speed correction curve, the vibration of the lower hook 150 (i.e., the cargo P) can be well suppressed. This speed correction curve is generated based on data stored in association with the position information (rotation angle position of the drive motor 40 from the origin) obtained from the encoder 41 and the motor torque command. In addition, in this step S5, the vibration component is averaged by square and compared with a predetermined threshold to determine whether the correction curve is good.

[0100] <Regarding the effects>

[0101] The method for setting up a winch, as described above, includes an encoder 41 that detects the rotation of a drive motor 40, and a load pulley 70 that is rotated by driving the drive motor 40, thereby winding or unwinding the load chain C1 to raise or lower the cargo. The method includes: a driving step in which the drive motor 40 is driven at a fixed rotational speed while applying tension to the load chain C1; a storage step in which the motor torque command value for controlling the drive motor 40 is stored in a memory 101 (memory unit) corresponding to the position information obtained from the encoder 41 in the driving step; and a speed correction curve calculation step in which a speed correction curve (function) is calculated to correct the speed command for driving the drive motor 40 based on the periodic variation of the motor torque command value stored in the storage step.

[0102] In this way, in the settings of the winch 10 (especially in the factory settings), for each winch 10 with different reduction ratios of the reducer or pitch lengths of the load chain C1, a speed correction curve for suppressing the vertical vibration of the lower hook 150 can be easily calculated based on the periodic variation of the motor torque command value. A speed command is then calculated based on this speed correction curve, and the drive motor 40 is controlled. Therefore, even if the distance between the centerline of the drooping load chain C1 and the rotation center of the load sheave 70 varies, and the resulting vibration differs in each winch 10, by calculating the speed command based on the speed correction curve generated from the pre-measured variation of the motor load and driving the drive motor 40, the variation in the hoisting speed of the load P can be appropriately suppressed, thereby suppressing vibration. Furthermore, as described above, by appropriately suppressing the variation in the hoisting speed of the lower hook 150 (load P) when driving the drive motor 40, resonance in the winch 10 can be prevented.

[0103] Furthermore, as described above, a speed correction curve is pre-made based on the motor torque command value used to suppress speed fluctuations in the speed control mode of the servo motor. The speed command is calculated based on the speed correction curve and the drive motor 40 is driven and controlled. Therefore, the control of the drive motor 40, which performs winding or unwinding at a speed based on the operator's operating command, becomes simple and does not require additional mechanical structures such as buffer devices, thereby suppressing the increase in cost.

[0104] Furthermore, in this embodiment, a load sensor 80 capable of detecting the load of the cargo P suspended on the load chain C1 is provided, and a determination step is provided. In this determination step, when the drive motor 40 is controlled to drive according to the speed command after correction based on the speed correction curve calculated in the speed correction curve calculation step S4, the vibration of the cargo P is determined based on the load detected by the load sensor 80 to be suppressed to not exceed a predetermined threshold. When it is determined in the determination step that the predetermined threshold is exceeded, at least the speed correction curve calculation step S4 is performed again in the descent step S1, the drive step S2, the storage step S3, and the speed correction curve calculation step S4.

[0105] Thus, in the control of the drive motor 40 based on the speed command corrected using the speed correction curve, the actual vibration of the cargo P is detected by the load sensor 80, thereby determining the vibration suppression effect. Furthermore, if the vibration suppression effect is low, such as when the vibration of the lower hook 150 (cargo P) exceeds a predetermined threshold, the speed command curve is calculated again, thus reliably achieving a state with a high vibration suppression effect.

[0106] In addition, in this embodiment, in the speed correction curve calculation step S4, the initial phase of the speed correction curve is calculated based on the position information in the maximum value Tmax and / or minimum value Tmin of the motor torque command value.

[0107] In this way, the initial phase of the periodically varying speed correction curve can be easily calculated. Furthermore, since the speed correction curve can be calculated while reflecting individual differences in the initial phase of the winch 10, speed variations can be effectively prevented when the drive motor 40 is in operation, thereby effectively preventing vibrations in the winch 10.

[0108] In addition, in this embodiment, the speed correction curve is calculated as a sine wave in the speed correction curve calculation step S4.

[0109] In this way, the calculation of the speed correction curve becomes easy, and the drive control of the drive motor 40 can be easily realized so that the drive motor 40 follows the speed command after correction using the speed correction curve based on a sine wave, thereby effectively suppressing the vibration of the lower hook 150 (cargo P).

[0110] In addition, the winch 10 of this embodiment includes: a memory 101 (storage unit) that stores motor torque command values ​​for controlling the drive motor 40 in correspondence with position information obtained from the encoder 41 when the drive motor 40 is driven; a speed correction curve calculation unit that calculates a speed correction curve to correct the speed command for driving the drive motor 40 based on the periodic variation of the motor torque command values ​​stored in the memory 101 (storage unit); and a control unit 100 and a driver 110 (motor control unit) that uses the speed correction curve generated by the speed correction curve calculation unit to correct the speed command and control the drive motor 40.

[0111] Therefore, as described above, in the setting of the winch 10 (especially in the factory setting), for each winch 10 with different reduction ratios of the reducer or pitch lengths of the load chain C1, a speed correction curve is pre-calculated using the motor torque command value when driving the drive motor 40 at a constant speed, and the drive of the drive motor 40 is controlled according to this speed correction curve. Thus, even if the distance (radius of rotation) between the centerline of the hanging load chain C1 and the rotation center of the load pulley 70 varies, and the vibration caused by this variation differs in each winch 10, by correcting the speed command based on the speed correction curve calculated based on the pre-measured variation of the motor load and driving the drive motor 40, variations in the hoisting speed of the cargo P can be appropriately suppressed. Furthermore, as described above, by appropriately suppressing variations in the hoisting speed of the lower hook 150 (load P) when driving the drive motor 40, resonance in the winch 10 can be prevented.

[0112] In addition, as described above, in order to suppress speed fluctuations, the upper command unit 102 calculates a speed command curve for suppressing vibrations caused by load fluctuations, and drives the drive motor 40 according to the speed command curve. Therefore, the control of the drive motor 40 becomes simple, and no additional mechanical structure such as a buffer device is required, thereby suppressing the increase in cost.

[0113] <Variation Example>

[0114] The various embodiments of the present invention have been described above, but the present invention can be modified in various ways. These will be described below.

[0115] In the above embodiment, during the driving period of the drive motor 40, the driving of the drive motor 40 is controlled according to the same speed command curve. However, it is also possible to divide the period from the driving of the drive motor 40 to its stop into multiple intervals, and change the variation coefficient k of the speed command curve (Equation 2) for each interval. For example, as... Figure 8 As shown, the vibration is greater than in other intervals when the drive motor 40 starts. In such intervals, by adjusting the variation coefficient k of (Equation 2), the vibration generated by the drive motor 40 can be further reduced.

[0116] Alternatively, instead of dividing the period from driving the drive motor 40 to stopping into multiple intervals as described above, the variation coefficient k can be set as a certain function.

[0117] Furthermore, in the above embodiment, the speed correction curve is calculated as a sine wave, but it can also be calculated as a triangular waveform based on the measured torque command value. In this case, the speed correction curve is also made such that the position representing the minimum value of the motor torque command value (rotation angle of the drive motor 40) coincides with the position representing the maximum value of the speed correction curve (rotation angle of the drive motor 40), and the position representing the maximum value of the motor torque command value (rotation angle of the drive motor 40) coincides with the position representing the minimum value of the speed correction curve (rotation angle of the drive motor 40). Regarding the amplitude of the speed correction curve, it can be calculated based on the change in arm length A accompanying the movement of the rotation angle of the drive motor 40.

[0118] Alternatively, a speed correction curve can be calculated by flipping a curve obtained by smoothing the measured torque command value. In this case, relative to the reference speed s determined by the pitch circle radius Rp of the load pulley 70, according to... Figure 3 The amplitude of the changing waveform can be determined by the difference between the maximum value of the arm length A0 and the pitch circle radius Rp, or the difference between the minimum value of the arm length A and the pitch circle radius Rp.

[0119] Furthermore, in this embodiment, the winch 10 is an electric chain hoist capable of speed and torque control of the drive motor 40. The drive motor is preferably a servo motor, and preferably includes a drive motor, an encoder, and a drive control device capable of accurately detecting the load torque acting on the drive motor based on the meshing position relationship (polygonal action) between the load pulley and the load chain.

[0120] In addition, the hoist 10 descends to the specified position in step S1 and stores the motor torque command in steps S2 to S3. However, it can also be configured such that after the total head of the hoist 10 is unwound, the total head is wound up and the motor torque command is stored in steps S2 to S3, and the speed correction curve (function) of the total head position is calculated and stored in the memory in step S4.

[0121] (Symbol Explanation)

[0122] 10…Winder, 20…Winder main body, 21…Housing, 30…Upper hook, 40…Drive motor, 41…Encoder, 50…Reduction mechanism, 60…Brake mechanism, 70…Load pulley, 71…Chain groove, 72…Bending point, 80…Load sensor (corresponding to load measurement unit), 100…Control unit, 101…Memory (corresponding to storage unit), 102…Upper command unit (corresponding to speed correction curve calculation unit), 110…Driver (corresponding to motor control unit), 130…Cylinder operating device, 140…Chain drum, 150…Lower hook, C1…Load chain, P…Cargo

Claims

1. A method for setting up a winch, the winch having an encoder for detecting the rotation of a drive motor, and the load pulley being rotated by the drive motor, thereby causing the load chain to wind up or unwind, thus raising or lowering the cargo. The method for setting up the winch is characterized in that, The load chain is a flat-joint chain formed by connecting longitudinal and transverse links as a group. The method for setting up the winch includes: The driving step involves applying tension to the load chain while driving the drive motor at a fixed rotational speed. The storage step stores the motor torque command value used to control the drive motor and the position information obtained from the encoder in the drive step in the storage unit. as well as The speed correction curve calculation step calculates a speed correction curve to correct the speed command driving the drive motor based on the periodic variations of the motor torque command value stored in the storage step. In the speed correction curve calculation step, the speed correction curve for suppressing periodic variations in the speed of the load chain is calculated by approximating the positional relationship between the load chain and the load pulley as a regular polygon, wherein the length of one side of the regular polygon is the length when the longitudinal link and the transverse link are grouped together.

2. The method for setting up a winch according to claim 1, characterized in that, The winch is equipped with a load sensor capable of detecting the load of goods suspended on the load chain. The hoist setting method includes a judgment step, in which, when the drive motor is controlled by a speed command corrected using the speed correction curve calculated in the speed correction curve calculation step, the method determines whether the vibration of the cargo is suppressed to not exceed a predetermined threshold based on the load detected by the load sensor. When the determination step determines that the threshold is exceeded, at least the speed correction curve calculation step is performed again in the driving step, the storage step, and the speed correction curve calculation step.

3. The method for setting up a winch according to claim 1, characterized in that, In the speed correction curve calculation step, the initial phase of the speed correction curve is calculated based on the position information in the maximum and / or minimum values ​​of the motor torque command value.

4. The method for setting up a winch according to claim 2, characterized in that, In the speed correction curve calculation step, the initial phase of the speed correction curve is calculated based on the position information in the maximum and / or minimum values ​​of the motor torque command value.

5. The method for setting up a winch according to any one of claims 1 to 4, characterized in that, In the speed correction curve calculation step, the speed correction curve is calculated as a sine wave.

6. A winch comprising an encoder for detecting the rotation of a drive motor, wherein the drive motor rotates a load pulley, thereby winding or unwinding a load chain, thus raising or lowering a load. The winch is characterized in that... The load chain is a flat-joint chain formed by connecting longitudinal and transverse links as a group. The winch has the following features: The storage unit stores the motor torque command value used to control the drive motor in correspondence with the position information obtained from the encoder when the drive motor is driven; A speed correction curve calculation unit calculates a speed correction curve to correct the speed command driving the drive motor based on the periodic variation of the motor torque command value stored in the storage unit; and The motor control unit corrects the speed command based on the speed correction curve calculated by the speed correction curve calculation unit, and controls the drive of the drive motor. In the speed correction curve calculation unit, by approximating the positional relationship between the load chain and the load pulley as a regular polygon, the speed correction curve for suppressing periodic variations in the speed of the load chain is calculated, wherein... The length of one side of the regular polygon is the length when the longitudinal link and the transverse link are grouped together.

Images