JP6353798B2 - Variable control method for climbing crane - Google Patents

Description

The present invention is, with respect to the load at the time of or during winding lowering movement of the suspended load, relates the operating speed of the climbing crane to a method for variably controlling.

Conventionally, in the operation of a climbing crane, for example, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 2005-22856), a method of increasing the frequency and accelerating as a method for shortening the operation time at light load is known. ing.
In this technology, the load factor is estimated by detecting electric power inside the inverter, the acceleration rate and the speed are always calculated, and the motor measurement torque is calculated from the calculation result.

JP 2005-22856 A

However, in the conventional method, the target rotational speed has to be calculated from the motor measured torque during acceleration.
On the other hand, the motor measurement torque has a problem that it takes more time than the averaging process and the response speed is poor.
In addition, in the case of a crane, during a constant speed after acceleration, the motor measurement torque always fluctuates due to the deflection of the jib or mast due to the influence of the suspended load, and vibration, so it cannot be distinguished from changes in winding layer or wire load. There is also a problem that cannot be accurately grasped.
The motor measurement torque here depends on the acceleration torque and the load torque from the relationship of the motor measurement torque = acceleration torque + load torque.
Since the motor measurement torque is calculated according to the disturbance and the motor rotation speed also changes, the motor rotation speed is not stable, adjustment is difficult, and operability in the lifting operation is also deteriorated.

The present invention has been made to solve the above-mentioned problems, and its main purpose is to immediately determine the target rotational speed from the load torque, and to avoid speeding without being disturbed by disturbances such as jib or mast deflection or vibration. The present invention provides a variable load control method for a climbing crane that can stabilize the load.

  In the present invention, the load torque is calculated, and the speed is controlled by determining the rotational speed of the motor from the calculated load torque.

That is, the climbing crane load variable control method according to the present invention includes a hook block for suspending a load, a drum around which a wire for suspending the hook block is wound, and a motor for rotating the drum in a winding direction or a lowering direction. And an inverter that controls the rotational speed of the motor, and calculates the suspended load (moving average value at regular intervals; the same applies hereinafter) in the normal mode, and always calculates the load torque applied to the motor based on this value. and it is, the normal to hold the suspended load when entering the light load mode from mode, to determine the load torque from the data of the load torque for hanging load when entering the light load mode from the normal mode The speed control can be shortened by determining the rotational speed of the motor according to the load torque.

According to the above method, it is possible to improve the operability of the crane with less speed fluctuation.
In addition, since the target rotational speed is determined instantaneously from the load torque, there is no backlash of acceleration in the light load mode, and speed control time can be shortened.

  According to the present invention, a variable load control of a climbing crane that can immediately determine a target rotational speed from the load torque in the light load mode and stabilize the speed without being disturbed by disturbances such as jib or mast deflection or vibration. A method can be provided.

The figure which shows the structure of a climbing crane apparatus typically Diagram showing the configuration of the arithmetic unit Figure showing the initial setting screen of the data setter Diagram showing the total length of the wire rope Relationship diagram between jib angle and gantry top angle Flow chart showing variable load control method for climbing crane

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention.

  FIG. 1 is a diagram schematically showing a configuration of a climbing crane apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, a climbing crane apparatus 100 according to an embodiment of the present invention has a mast 2 on a base frame 1, and a crane body 3 is disposed on the top thereof.

  The crane body 3 includes a revolving body 4 rotatably supported by a revolving bearing (not shown) provided on the top of the mast 2 and a cockpit 5 operated by an operator.

The swing body 4 includes a jib 6 that can be raised and lowered with the swing body 4 as a base point, a gantry 7 that serves as a lifting support point for the jib 6, and a drum 8.
The drum 8 includes a hoisting drum 9 and a hoisting drum (not shown), and each drum is provided with a hoisting motor 10 and a hoisting motor (not shown) for rotating the drum. .
Further, the hoisting motor 10 is provided with an inverter 11 for controlling the rotational speed of the motor.

A sheave 12 is provided at the top of the jib 6, and a sheave 13 is provided at the top of the gantry 7.
One of the wire ropes 14 is wound around the winding drum 9. The other wire rope 14 is turned back from the hoisting drum 9 via the sheaves 13 and 12 by the hook block 15 and wound around the undulation drum via the sheaves 12 and 13.

The motor shaft of the hoisting motor 10 includes a hoisting drum 9 and a pulse transmitter 16 for calculating the PCD of the wire rope 14 wound on the hoisting drum 9.
Further, at the base of the jib 6, a jib angle meter 17 for calculating the rope length according to the angle of the jib is provided.
A load cell 18 for measuring a suspended load is provided at a position suspended from a sheave 13 provided at the top of the gantry 7. The installation of the load cell 18 is not limited to the position described above, and may be near the top of the jib 6.
Further, an overwind limit switch 19 is attached near the top of the jib 6 to prevent the load from being excessively wound and coming into contact.

FIG. 2 shows a configuration diagram of a computing device for a climbing crane in the present embodiment. Hereinafter, reference numerals and the like in the constituent elements will be described with reference to FIG.
As shown in FIG. 2, the input / output device configuration of the climbing crane is a PLC 20 that is a calculation unit, a DA converter 21 that converts the data of the PLC 20 into analog, an inverter 11, and a hoisting motor that drives the hoisting drum 9. 10, a pulse transmitter 16, a load cell 18, an AD converter 22 for digitally converting data output from the load cell 18, a jib angle meter 17, and data converted from the jib angle meter 17. The AD converter 23, the data setting unit 24, and the control lever unit 25 are configured.

A DA converter 21, a pulse transmitter 16, AD converters 22 and 23, a data setting unit 24, and a control lever unit 25 are connected to the PLC 20.
While the hoist motor 10 is being driven, the pulse transmitter 16 always outputs a pulse corresponding to the forward or reverse rotation of the motor to the PLC 20.
The PLC 20 accumulates pulse accumulation data by adding or subtracting the pulses output from the pulse transmitter 16.

The load cell 18 measures the suspended load when the power is turned on to the control panel and outputs data to the PLC 20 via the AD converter 22.
The jib angle meter 17 measures the angle of the jib and calculates data to the PLC 20 via the AD converter 23 in order to calculate the total length of the wound wire described later.
The data setter 24 outputs the data input on the initial setting screen of the data setter 24 described later to the PLC 20 in advance.
The control lever device 25 is an operation lever for the operator to switch from the normal mode to the light load mode. When the control lever device 25 is "ON" or "OFF", the signal is output to the PLC. In the present embodiment, the control lever is used. However, the present invention is not limited to this, and for example, a switch may be used.

FIG. 3 shows an example of an initial setting screen of the data setting device set by the user in the present embodiment. Hereinafter, reference numerals and the like in the constituent elements will be described with reference to FIGS.
As shown in FIG. 3, on the initial setting screen of the data setting unit 24, the winding drum winding layer setting 30, the winding drum winding number setting 31, the overwinding LS length setting 32, the wire diameter setting 33, the undulations A drum winding number setting 34, a reduction ratio (not shown), a jib length (not shown), an overall winding efficiency (not shown), an overall winding efficiency (not shown), and the like can be set. .

Further, on the display screen of FIG. 3, the current winding layer 36 of the hoisting drum, the current winding number 37 of the hoisting drum, and the rope length meter pulse count 38 are displayed.
The winding drum current winding layer 36, the winding drum current winding number 37, and the rope length meter pulse count 38 on the display screen are constantly fluctuating depending on the operation of the crane.
The initial setting screen of FIG. 3 is input with a touch panel, but the present invention is not limited to this, and a digital switch, volume, punch card, or the like may be used.

  The winding drum winding layer setting 30 and the winding drum winding number setting 31 are set such that one of the wire ropes 14 is wound around the winding drum 9 and the other is folded back by the hook block 15 and wound around the undulation drum. The number of turns and the winding layer of the wire rope 14 wound around the hoisting drum 9 when the hoisting hook block 15 is applied to the overwinding limit switch 19 are input.

The overwinding LS length setting 32 is configured to input the distance from the jib top to the overwinding limit switch 19.
The wire diameter setting 33 is input with the measured wire diameter.
The undulation drum winding number setting 34 is configured to input the number of turns of the wire rope 14 wound around the undulation drum (not shown) in a state where the hook block 15 is applied to the overwinding limit switch 19 as described above.

When an initial value is input to the above item on the initial setting screen and then setting 35 is pressed, the drum PCD is calculated using the value of the wire diameter setting 33 on the PLC 20.
Here, the drum PCD is obtained by the following equation (1).

D _d = (D _m + D _y ) + (D _y × √3 × (coil layer-1)) × K (1)
Here, _{D d} drum PCD, _{D m} is the winding on the drum diameter, _{D y} is the wire diameter, K is shows a correction coefficient, respectively.
In the drum PCD, when wire ropes are actually stacked, the lower wire rope is slightly crushed, resulting in an error from actual measurement. For this reason, it is necessary to perform correction in consideration of the amount of crushing as in the correction coefficient K in Expression (1).

Here, the hoisting drum diameter is a fixed value, and the wire diameter is the value of the wire diameter setting 33 in FIG. 3, so that the drum PCD for each winding layer can be easily calculated by the equation (1).
The drum PCD calculated by the equation (1) is stored for each layer in the data memory in the PLC 20.
In the following, the drum PCD refers to the one including the diameter of the wire rope laminated on the winding drum diameter, as can be seen from the equation (1).

Next, the winding length for each winding layer is calculated from the drum PCD of each layer obtained by the equation (1).
For example, reel length N ₁ of the first layer is obtained using the following equation (2).
N ₁ = D _d of the first layer × π × rated winding number (2)
Further, the winding length of the second layer N ₂ are obtained by using the equation (3).
N ₂ = N ₁ + D layer D _d × π × rated number of turns of the second layer (3)
Further, the winding length N ₃ of the third layer is obtained by using the equation (4).
N ₃ = N ₂ + _3rd layer D _d × π × rated winding number (4)
Thus, the fourth and subsequent layers are also demanded in the same manner. The rated number of turns here varies depending on the size of the installed drum. In addition, _{D d} refers to the drum PCD.
These winding lengths are stored in the data memory in the PLC 20 in association with the drum PCD for each layer obtained by the above equation (1).

  That is, after setting each item on the initial setting screen, when setting 35 is executed, drum PCD and winding length data for each winding layer are calculated in the PLC 20, and drum PCD and winding length for each layer are calculated. The data table has been completed.

When the setting 35 is executed, the initial value of the rope length meter pulse count 38 is calculated by the equation (5) and displayed on the rope length meter pulse count 38.
P _c = ((M _r −1) × rated winding number + M _n ) × G _r × P _r (5)
Here, the symbols of the equation (5) are: P _c : rope length meter pulse count, M _r : value input in the winding drum winding layer setting 30, M _n : value input in the winding drum winding number setting 31, _Gr : reduction ratio, _Pr : the number of pulses per rotation.
Here, since P _r and G _r are fixed values, P _c can be easily determined.
Further, the rope length meter pulse count 38 after the initial setting is changed by adding or subtracting the value displayed at the time of the initial setting according to the value output from the pulse transmitter 16 according to the operation of the crane.

The current winding layer 36 of the hoisting drum and the current winding number 37 of the hoisting drum indicate the winding layer and the number of turns that vary depending on the operation of the crane.
The current winding layer 36 of the winding drum and the current winding number 37 of the winding drum are obtained by the following equation (6).

( _Pc / _Pr / _Gr ) / rated number of turns = quotient + remainder (6)
Here, the quotient +1 is the current winding layer, and the remainder is the current winding number, which are displayed in the winding drum current winding layer 36 and the winding drum current winding number 37, respectively.
That is, since P _r and G _r are fixed values, the current winding layer and the number of turns can be easily obtained by a rope length meter pulse count that varies according to the operation of the crane.

Next, calculation of L ₀ will be described with reference to FIG. FIG. 4 is an example showing the entire length of the wire rope of the present embodiment. Hereinafter, reference numerals and the like in the constituent elements will be described with reference to FIG.
As shown in FIG. 4, the total length (L ₀ ) of the winding wire is obtained by the following equation (7).
L ₀ = L ₁ + L ₂ + L ₃ × 2 + L ₄ + L ₅ × 2 + L ₆ + L ₇ × 2 (7)
Here, L ₁ is the current winding drum winding length, L ₂ is the current rolling drum winding length, L ₃ is between the sheave 40 provided on the gantry top and the sheave 41 provided on the jib top, or the sheave. 44 from the length between the sheaves 43, L ₄ is the length between the sheaves 40 provided from the hoist drum 9 in gantry top, L ₅ is between sheave 45 from sheave 44 provided on the gantry top, or sheaves 46 is a length between the sheave 45 and L ₆ is a length between the undulation drum 9 a and the sheave 46 provided on the gantry top, and L ₇ is a length between the sheave 41 or 43 provided from the jib top and the sheave 42 is provided. Show.
Hereinafter, L ₇ is also expressed as a hanging wire length.

L ₀ is calculated on the basis of the value entered in the initial setting screen of FIG.
That is, the calculation is performed with the hook block 15 hitting the overwind limit switch 19.
In this state, L ₇ is equal to the length between the jib top and the overwind limit switch 19. Length from Jibutoppu to between overwind limit switch 19 for a fixed value, L ₇ is derived. That is, L ₇ is a value entered in the overwinding LS length setting 32.

L ₁ is less quotient computed by Equation (6), that is calculated from the following equation (8) using the data table in the PLC from the current wound layer and number of turns.
L ₁ = (current winding layer-1) winding length to layer + D _d × π × current winding number (8)
Here, D _d indicates the drum PCD.

L ₂ is given by: (9).
L ₂ = (undulation drum diameter + winding wire diameter) × π × undulation horizontal winding number × K ₁ (9)
Here, K ₁ denotes a correction coefficient.
L ₂ actually varies depending on the angle of the jib. It also depends on the number of wires.
Therefore, as the correction factor K ₁ of the formula (9), it is necessary to perform correction by the correction and multiplying the number by the jib angle.
Undulating drum size is a fixed value, the wire diameter and undulating horizontal turns winding is, L ₂ Substituting the value set in the wire diameter setting 33 in Figure 3 with undulating drum turns set 34 in equation (9) is readily calculated can do.

ここで、ＡとＢとφは固定値であり、θはジブ角度計１７から導き出されるため、Ｌ_３は容易に計算することができる。 It will now be described with reference to FIG calculation of L _3. FIG. 5 is a diagram showing the relationship between the jib angle and the gantry top angle of the present embodiment.
As shown in FIG. 5, when the jib length is B, the length from the jib root to the gantry top is A, the jib angle is θ, and the gantry top angle is φ, L ₃ is obtained by the following equation (10). .

Here, since A, B, and φ are fixed values and θ is derived from the jib angle meter 17, L ₃ can be easily calculated.

Next, L _{4 to} L ₆ are fixed values, and data is stored in the PLC 20 in advance.
L ₀ at the time of initial setting is calculated using the values of L _{1 to} L ₇ described above.

In the crane work is always change except L _0. L ₇ at the time of crane operation using the L ₀ calculated in the foregoing is obtained by the following equation (11).
L ₇ = (L ₀ − (L ₁ + L ₂ + L ₃ × 2 + L ₄ + L ₅ × 2 + L ₆ )) / 2 (11)

Next, a variable load control method for the climbing crane apparatus that shortens the operation time by calculating the load torque applied to the motor in the light load mode and controlling the rotation speed of the motor will be described with reference to the flowchart of FIG. .
FIG. 6 is a flowchart showing a load variable control method of the climbing crane apparatus. Hereinafter, reference numerals and the like in the constituent elements will be described with reference to FIGS.

First, as a preliminary preparation, an initial value is input to the data setting unit 24 on the above-described initial setting screen, and data is output to the PLC 20. Further, a frequency table corresponding to the torque is created in the PLC 20.
As shown in FIG. 6, when the normal operator operates the climbing crane apparatus 100, the power source of the control panel is first turned on (step S1).

Next constantly measure suspended load W _t by the load cell 18 when the power supply of the control panel is turned on at step S1, is calculated the moving average data in PLC 20 (Step S2). Further, when the jib 6 is turning or undulating and the wire rope 14 is being wound and unwound, the suspension load W _t constantly fluctuates. Therefore, the suspended load W _t step S2 is constantly monitored by the load cell to calculate a moving average value for each predetermined time, it is stored as internal data PLC 20.

Next, calculate the wire length L ₇ down drum winding layer and the vertical, it added suspended load (moving average) value in step S2, and calculates the load torque T (step S3). That is, during the hoisting / lowering operation, the load torque is always calculated based on the suspended load value of the moving average value at regular intervals. Further, the relationship between the suspended load value and the load torque is overwritten and stored in the PLC 20.
In actual data processing, step S2 and step S3 are calculated instantaneously to calculate the load torque T, and the load torque T is always calculated and stored in the internal data during normal winding up and down operation. Compared to the table.
The aforementioned load torque T is obtained by the following equation (8).
T = (D _d / 2) × (W _t + W _f + W _y ) × g / N _y / reduction ratio / η (8)
T: load torque, _{D d:} drum PCD, _{W t:} hanging load, _{W f:} hook load, _{W y:} wire load, g: gravitational acceleration,: _{N y:} wire hanging number efficiency: eta

  Next, it is determined whether or not the operator turns on a switch for increasing the winding speed in the normal mode with the operation lever (step S4). If the switch is not turned on here, the process returns to the suspension load measurement (step S2) and the suspension load measurement is repeated.

  If the switch is turned on in step 4, a light load acceleration flag is set (step S5).

  Next, when the light load acceleration flag is set, the suspension load (moving average) value when the operator switches on with the operation lever is held (step S6).

  Next, the load torque is determined from the load torque data corresponding to the suspension load value that is always stored in step S2 as the suspension load value in step S6 (step S7).

  Next, when the load torque is determined in step S7, the frequency is also determined immediately (step S8). Here, since the frequency table corresponding to the torque is stored in the PLC 20 in advance, if the load torque is known, the frequency can be immediately determined from the table.

Next, the frequency determined in step S8 is commanded to the inverter to accelerate the motor rotation speed (step S9).
That is, when the suspension load value is held in step S6, the load torque in step S7 and the frequency in step S8 can be immediately called from the PLC 20, so that the motor can immediately start acceleration.

Next, the load torque is recalculated (step S10).
Even if the suspension load value is maintained during the light load mode, the winding drum winding layer and the hanging wire length L7 continuously change during operation. Therefore, since the load torque also changes, it is necessary to recalculate.
When the recalculation of the load torque is completed, the frequency is immediately determined from a frequency table corresponding to the torque stored in the PLC 20 in advance (step S8).

By repeating the above, in the operation in the light load mode, while maintaining the suspended load value, the load torque is recalculated according to the change of the winding drum winding layer and the hanging wire length L7, and the operation is performed at the optimum speed. It becomes possible.
Although the suspension load fluctuates due to deflection or vibration of the jib or mast, since the suspension load is maintained in the light load mode, the load torque does not change greatly, and the operability of the operator is not impaired.
Further, since the moving average of the suspended load and the load torque for the suspended load are always calculated in the normal mode and stored in the PLC, the PLC data can be called immediately without being calculated again at the start of the light load mode. As a result, the operability of the crane can be improved since there is no backlash of acceleration at the start of the light load mode.

The present invention can be used for a climbing crane capable of variably controlling the speed according to the load.

8 Drum 9 Hoisting drum 10 Hoisting motor 11 Inverter 14 Wire rope 15 Hook block 16 Pulse transmitter 17 Jib angle meter 18 Load cell 20 PLC
24 data setter 100 climbing crane device

Claims (4)

A hook block to suspend the load,
A drum around which a wire for hanging the hook block is wound;
A motor that rotates the drum in the winding or lowering direction;
An inverter for controlling the rotational speed of the motor,
In the variable load control method of a climbing crane that operates at a constant speed in the normal mode and shortens the operation time by controlling the rotation speed of the motor in the light load mode,
Load suspended in the normal mode (fixed time each of the moving average value. Hereinafter, the same.) Is calculated, the value is always calculates a load torque applied to the motor based on, enters the light load mode from the normal mode hanging load is hold during the said normal to determine the load torque from the data of the load torque for hanging load when entering the light load mode from mode to determine the rotational speed of the motor in accordance with the load torque A variable load control method for a climbing crane that can shorten speed control. The load torque is
A drum PCD calculated from the wire winding layer of the drum that fluctuates by winding up and down;
Wire load that fluctuates by winding and lowering,
Suspension load, which is a moving average value at regular intervals,
A predetermined hook block load,
The reduction gear ratio of the reduction gear set in advance,
Efficiency that fluctuates depending on the value of the suspension load during winding and lowering,
Gravity acceleration,
The climbing crane load variable control method according to claim 1, which is calculated by:   The climbing crane load variable control method according to claim 2, wherein the wire load is calculated from a hanging wire length.   2. The variable climbing crane load control method according to claim 1, wherein the determination of the number of rotations of the motor is immediately determined by a frequency table corresponding to a load torque stored in advance in the PLC.

Images