JPS6114073B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suspended load swing control device suitable for use in a horizontal retractable crane, particularly a hydraulic retractor.

A horizontal retractable crane transports a suspended load at a predetermined location onto a hopper, and requires a retracting device to move the suspended load horizontally.

This retracting device includes a rack and pinion type, a screw rod nut type, a rope type, a hydraulic type, etc., and in recent years, a so-called mechanical and electric retracting device of the screw rod nut type has been widely used. Such a retracting device is disclosed, for example, in Japanese Patent Laid-Open No. 51-65472.

As shown in FIGS. 1 and 2, the screw bolt/nut type retraction device includes a drive motor 12 equipped with a disc brake 13, and a pinion 15 linked to the drive motor 12 via a shaft coupling 14. and gear 1 meshed with pinion 15.
6, a screw nut 17 and a rod 18 connected to the gear 16, the base is supported by the mast 5, and the tip of the screw rod 18 is connected to the main boom 2 by a pin 4, and the drive motor When the screw rod 12 is driven, the rotational force is applied to the screw rod 1 through the shaft coupling 14, pinion 15, gear 16 and screw nut 17.
8, the screw rod 18 advances and retreats in its axial direction, causing the main boom 2 to look up. The held suspended load gripping device 7 moves horizontally and is conveyed from the hatch 9 onto the hopper 8.

In addition, in the figure, 3 is a retracting device, 10 is a machine room, and 11
is the driver's cabin.

The hanging load swing control device for the horizontal retractable crane equipped with the screw rod nut type retracting device described above consists of a steady rest pattern generator and a detector for detecting the position of the suspended load, and the operation method thereof is as follows. will be explained with reference to the block diagram of FIG. That is, the operator command 25 by the operator's control lever operation is transmitted to the second switch 2.
0' is transmitted to the drive motor 12 via the amplifier 21 and the generator 22, the drive motor 12 is driven to operate the retraction device 3, and the suspended load gripping device 7 is operated via the link mechanism 23 with a pendulum movement. The operator visually measures the deflection 24 of the suspended load gripping device 7 at this time, and then checks the deflection 24 himself again.
Operate the control lever in stages to eliminate the Then, when the hanging load gripping device 7 is positioned above the hopper 8 from the hatch 9, a detector 26 such as a limit switch is activated, and the first switching device 20 and the second switching device 20' are activated in response to a command from the detector 26, and the operator The command is separated, and pattern control in the steady rest pattern generator 19 is performed. However, since the above-mentioned deflection control device performs pattern control in a state of irregular pendulum movement, the influence of the deflection of the suspended load gripping device 7 is given as a disturbance to the control system such as the drive motor 12, and in effect the suspended load The steady rest effect cannot be obtained. In addition, in order to effectively perform pattern control using position detection, the operator needs to perform a certain amount of correction operation for the shake of the suspended load gripping device 7, and this correction operation requires skill.
There are some things that are not currently being done.

Therefore, a hydraulic retracting device using a hydraulic cylinder in which the disturbance caused by the above-mentioned load fluctuation does not affect the control system was developed. However, in the case of a hydraulic retraction device, the natural frequency ω of the entire crane is
_N is approximately 1/3 compared to a mechanical retraction device.

However, M: Equivalent inertial mass K: Bulk modulus of oil A ₁ , V ₁ : Area and volume on the rod side of the hydraulic cylinder A ₂ , V ₂ : Area and volume on the head side of the hydraulic cylinder For this reason, the control system The response is reduced to about 1/3, making it impossible to control the hanging load's steady rest pattern using the position detection described above.

An object of the present invention is to provide a control device that can effectively and easily prevent a suspended load from swinging in a horizontal retractable crane equipped with a hydraulic retracting device.

The present invention detects the rod displacement of a hydraulic retraction device, the elevation angle of the main boom, and the swing angle of the suspended load, and uses the detection signals of the rod displacement and the elevation angle of the main boom to hydraulically determine the horizontal speed of the top boom tip. Calculate the inverse transfer function that converts to the speed of the rod of the pulling device, differentiate the hanging load swing angle detection signal to find the hanging load swing angular velocity, and multiply the speed command and the reverse transfer function by the hanging load swing angular velocity. The method is characterized in that the difference (velocity deviation) with the value obtained is determined, a control command that eliminates this difference (reduces it to zero), and the hydraulic retracting device is controlled by this control command. Hereinafter, a fourth embodiment of the hanging load swing control device of the present invention will be described.
A description will be given of FIGS. 13 to 13.

As shown in FIGS. 4 and 5, the hydraulic retraction device that is controlled by the control device of the present invention has a head 34 of a hydraulic cylinder 27 supported on a mast 5, and a rod 33 of the hydraulic cylinder 27. The tip is supported on the main boom 2 by a pin 4. next,
Its operation will be explained with reference to the hydraulic circuit diagram in FIG. The hydraulic pump 38 is driven by an electric motor, and the proportional pressure control valve 39 supplies oil at a desired pressure to the hydraulic cylinder 2 via the main electromagnetic valve 37.
By supplying oil to the rod side 33 or head side 34 of the hydraulic cylinder 27, the rod 33 of the hydraulic cylinder 27 moves forward and backward. Note that the pressure oil in the circuit flows in the direction of the solid line arrow when the rod 33 is extended, and in the direction of the broken line arrow when the rod 33 is retracted. The expansion and contraction speed of the rod 33 of the hydraulic cylinder 27 is the same as that of the hydraulic cylinder 2.
The amount of oil supplied to the hydraulic cylinder 7 and the amount of oil discharged from the hydraulic cylinder 27 are adjusted, and the amount of oil is adjusted by the input electric signal 42 of the first control valve 36 and the second control valve 36'. be exposed. In addition, the above-mentioned hydraulic circuit uses the hydraulic cylinder 27 in the case of rod extrusion.
This is a so-called differential circuit system in which the pressure oil from the rod side 33 of the hydraulic cylinder 27 passes through the pilot check valve 35 and the proportional flow control valve 36' and joins the oil discharged from the hydraulic pump 38. It is configured to reduce the speed difference due to the area difference between the sides 33.

In FIG. 4, 28 is a hydraulic hose, and 29 is a hydraulic unit. Further, in FIG. 5, 35' is a pilot check valve on the head side, 40 is a solenoid valve, and 41 is a control valve amplifier.

Therefore, the hanging load swing control device of the present invention includes a detector for detecting the displacement of the rod of the hydraulic retracting device;
A detector that detects the elevation angle of the main boom, a detector that detects the swing angle of the suspended load, and the electrical signals detected from the aforementioned detectors are stored and programmed to calculate the results and the swing angle of the suspended load. and a controller for commanding the hydraulic retracting device in combination with corresponding contents.

The rod displacement detector is as shown in FIG.
Attach the rack 4 to the tip of the rod 33 of the hydraulic cylinder 27.
3 is fixed so that it moves forward and backward together with rod 33,
A rotational displacement meter 43' is engaged with the rack 43 and the detected displacement is sent as an electrical signal 65.

The main boom elevation angle detector is located at the base 48 of the main boom 2, as shown in FIGS. 7a and 7b.
is fixed to an elevating main shaft 50 supported by a bearing 49,
A disk 52 having a large number of radially slits 53 is fixed to the main shaft 50, a light source 54 and a light receiver 55 are disposed between the disk 52, and a pulse counter 56 is linked to the light receiver 55. , the detected elevation angle is sent as an electrical signal 64.

As shown in FIG. 6, the hanging load swing angle detector is
A tilt angle detector 30 is installed inside the hanging load gripping device via a vibration isolating rubber 46, and a telemeter transmitter 3 consisting of an A/F converter 58 and a parallel-to-serial converter is installed.
1 is installed, and a telemeter receiver 62 consisting of a series-parallel converter 60 and an F/V converter 61 is installed on the controller side, and is configured to sequentially wirelessly transmit the detected deflection angle 24 of the suspended load. has been done. As shown in FIG. 6, in the above-mentioned hanging load grasping device, when the opening/closing rope 44 is operated as shown by the solid line arrow or the broken line arrow, the bucket bag 47 is moved through the opening/closing drums 45, 45' as shown by the solid line arrow or the broken line arrow. Open and close.

As shown in the block diagram of FIG. 8, the controller 32 includes an internal register 71 and an arithmetic unit 74 that perform operations according to macro instructions, and a microinstruction ROM 72 that stores microinstructions.
and issue that microinstruction at the specified address.
A ROM address register 73 and a read-only macro instruction ROM 70 that stores macro instructions.
, a RAM 69 that stores intermediate results of calculations, a read-only table setting ROM 68 that stores tables necessary for calculations, the RAM 69, a ROM 70 for macro instructions, and a ROM 7 for micro instructions.
2, and an address register 75 that stores the addresses of each memory and input/output addresses, and selects and stores only address information from the data appearing on the output bus 76, and an address register 75 that is externally connected to the controller 32. An input/output buffer circuit 6 consisting of a device interface
It consists of 7.

FIG. 9 is a model diagram showing the dimensions of the horizontal retractable crane. The symbols used in FIG. 9 are as follows. a is the length of the main boom, b is the length from the tip of the rod to the pivot point E, c+d is the length of the top boom, e+f is the length of the mast, and g is the length from the base end D of the rod to the pivot point E. δ ₀ is the angle between the ground and the member connecting the pivot point E and the base end D, and ₀ is the angle between the mast and the ground. The codes up to this point are constant data. Next, variable data will be explained. x is the rod displacement of the hydraulic cylinder, _α1 is the elevation angle of the main boom, θ is the swing angle of the suspended load, y is the displacement of the top boom tip A, and δ is the distance between the member connecting the pivot point E and the base end D, and the main boom It is the angle formed by

Next, using Fig. 9, find the transfer function G of the link mechanism system of the speed y〓 (=dy/dt) of the top boom tip A to the speed x〓 (=dx/dt) of the rod tip B of the hydraulic cylinder. .

First, the displacement y at point A is y=a·cos(α ₁ + ₀ )+c·cos(α ₁ +α ₂ + ₀ ) ……(1). By differentiating this equation (1), y〓 is obtained, and when this y〓 is further rearranged, the following equation is obtained.

y〓=-α〓 ₁ {a・sin( _α1 + ₀ )+c・cos( _α1 + _α2 + _α0 )・(1+1+R/1+S)}……
(2) Here, R=a·f sin α ₁ /α·e sin α ₃ S=a·d sin α ₂ /e·f sin α ₄ Furthermore, the relationship between x and α ₁ is obtained as follows.

x ² = b ₂ + g ₂ −2bg cosα ₁ …………(3) From equation (3), α ₁ = x/b・g sinα・x〓 …………(4) In equation (2) above, Substituting equation (4) and finding the transfer function G, we get the following.

G=〓/〓=1/b・g sinα{ax sin( _α1 + ₀ )+cx cos( _α1 + _α2 + ₀ )(1-1+R/1+S)
}...(5) Here, m=b・g sinα ₁ n=ax sin(α ₁ + ₀ ) P=cx cos(α ₁ +α ₂ + ₀ ), then G=1/m{n+p(1 −1+P/1+s)}……
…(6) becomes. This transfer function G is a variable.

The inverse transfer function is obtained as the reciprocal of the transfer function G, ie, 1/G.

Next, the operation of the controller 32 will be explained based on the flowchart of FIG.

First, ○I to ○H and ○H to ○R are executed one after another in accordance with the program stored in the micro ROM 72 according to instructions from the ROM address register 73 set initially. First, interrupts are disabled, a program for initial setting (initial transfer function calculation) is executed, and then interrupts are canceled and the following processing is executed.

B. Set constant data (for example, the lengths of the main boom 2 and top boom 1) configured by the link mechanism 23 stored in the macro instruction ROM 70.

○B An electric signal 64 of the elevation angle of the main boom 2,
The electric signal 65 of the rod displacement of the hydraulic retracting device is directly converted into a digital signal by the A-D converter 63', and temporarily stored in the input/output buffer 67, and digital variable data corresponding to the swing angle 24 of the suspended load is generated. Eθ is always input/output buffer 67
Store in.

○C The above constant data and variable data are transferred to the macro instruction ROM 70 and the table setting ROM 6 by the program in the micro instruction ROM 72.
Calculation formula stored in 8 (for example, m=b・g・
sin(α ₁ + ₀ − δ ₀ )), operations are performed in the operation unit 74 through the internal register 71 one after another. The calculation result (for example, m) is sent to an arbitrary address through the address register 75.
It is stored in the RAM 69 and calculations are performed one after another. Then, the final result G of a certain address is
It is set in the RAM 69, and the calculation is repeated again by returning to ○○○.

At this time, if a timer interrupt of To occurs during the execution of the operation at ○C, the execution of the operation is interrupted, the address register 75 is saved, and then the operation jumps to ○.

○chi Input the swing angle θ of the hanging tool, and use the data θp from this sampling and the data θp-1 from the previous sampling to calculate the swing angular velocity △θ of the lifting tool.
seek. That is, Δθ is obtained by differentiating θ.

○I Multiply the reciprocal value of the transfer function G obtained in the process of ○D above, that is, the inverse transfer function 1/G, by the swing angular velocity of the hanging tool obtained in the process of ○C,
Find Hout.

○ Nu Perform level conversion calculations to amplify the output level corresponding to the input of the proportional flow rate control valve 36 and control valve amplifier 41 that adjust the expansion and contraction movement of the hydraulic cylinder 27. However, A ₁ is the hydraulic cylinder 27
The area of the head side 34 of , k is the amplifier gain.

○ru Calculate the deviation Ei between the hydraulic cylinder speed command E ₀ and the value E ₁ calculated in ○nu. Then, a control command i is output that sets this deviation Ei to Ei=0.

Then, once the above-mentioned round program is completed,
Return to the jumped address register 75 again,
The calculation program in ○C and the variable data setting program in ○B and ○D are executed until a timer interrupt occurs.

In FIG. 8, 77 represents an input bus, and 78 represents an address bus.

Next, an example of the programming method of the flowchart shown in FIG. 10 described above will be explained with reference to FIG. 11.

First, calculate the initial transfer function by disabling interrupts to obtain the initial transfer function of the link mechanism system 23 before operation. Next, by canceling interrupts, calculate the flow of output commands using the timer interrupt pulse, and control The input voltage 42 of the valve amplifier 41 is output. Then, the flow returns to the transfer function calculation flow again and the transfer function is calculated. However, if an interrupt pulse To is input during the calculation, the same operation as described above is performed, and each time the rod speed changes due to the change in the swing angular velocity of the suspended load. A correction operation is performed.

Next, with reference to FIGS. 12 and 13, a correction operation based on a change in hanging load swing when using the control device of the present invention and an operation method for giving an arbitrary command from the controller at the initial stage of operation will be explained.

First, the input voltage 42 is given to the control valve amplifier 41 by the operator's speed command 25, and the oil amount of the proportional flow control valves 36, 36' is adjusted by the output current i of the control valve amplifier 41. By changing the expansion/contraction speed, the suspended load is moved via the link mechanism system 23, and during the movement process, the suspended load swings 24, and an electric signal corresponding to the swing angle is given to the controller 32. Calculations are performed in the controller 32 as described above, and a correction electric signal is given from the controller 32 to the control amplifier 41 to try to suppress the swing 24 of the suspended load within a certain range, and as a result, when the suspended load is moved, It is possible to suppress the swinging of a suspended load or the fluctuating load applied to a member within an arbitrary range.

The one in FIG. 13 is a program pattern command 79 that is an operator command 25, and includes a hydraulic cylinder 27 displacement 65 and a main boom 2 depression/elevation angle 6.
By providing the hanging load steadying pattern determined from 4 from the controller 32, operator operations are no longer required, automatic operation is possible, and work efficiency is improved.

As described above, in the present invention, a controller composed of small arithmetic elements is used to detect and calculate the displacement of a hydraulic cylinder, the elevation angle of the main game, and the swing angle of a suspended load. It is configured to calculate the inverse transfer function of the link mechanism system and feed the result to the hydraulic control system to suppress the swing of the suspended load within a specified range, making it easy and reliable even for inexperienced operators. The swing of the suspended load can be stopped. In addition, since the variable load applied to the crane body can be reduced, the weight of the crane can be reduced, and any control method can be achieved by simply changing the program in the controller, so it is possible to standardize the controller. I can do it.

In addition, as in the above embodiment, the detected electric signal is converted into a digital signal and calculation is performed in the controller, and the resulting digital signal is converted into an electric signal and commanded to the hydraulic cylinder. This can be done quickly by transmitting wirelessly.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a horizontal retractable crane equipped with a conventional screw rod nut type retracting device;
Fig. 2 is a longitudinal sectional view of a conventional screw bolt/nut type retraction device, Fig. 3 is a flowchart showing the operating method of the conventional screw bolt/nut type retraction device, and Figs. 4 to 13 The figures show a specific example of the load swing control device of the present invention, FIG. 4 is a schematic diagram of the device installed in a horizontal retractable crane, and FIG.
The figure is a hydraulic circuit diagram of the hydraulic retraction device, Figure 6 is an explanatory diagram of the suspended load gripping device, Figure 7 is an enlarged view of the base of the main boom, Figure 8 is a block diagram of the controller, and Figure 9 is horizontal. A model diagram showing the dimensions of the retractable crane, Figure 10 is a flowchart showing how to operate the controller, Figure 11 is an explanatory diagram showing the programming method, Figures 12 and 13.
The figure is a flowchart showing a specific example of the operating method. 1...Top boom, 2...Main boom, 4
... Hoisting rope, 5 ... Hanging load gripping device, 24 ...
Swing of hanging load, 27...Hydraulic cylinder, 30...Inclination angle detector, 31...Telemeter transmitter, 32...
... Controller, 36 ... Proportional flow control valve, 6
2...Telemeter receiver, 64...Link depression/elevation angle, 65...Hydraulic cylinder displacement, 67...I/O buffer circuit, 68...Table setting ROM,
69...RAM, 70...ROM for macro instructions, 7
1...Internal register, 72...For micro instructions
ROM, 73...ROM address register, 74...
...Arithmetic unit, 75...Address register, 7
9...Program pattern.

Claims (1)

[Scope of Claims] 1. A controller, a hydraulic retracting device supported by a mast and capable of expanding and contracting in the horizontal direction in accordance with control commands from the controller, and a hydraulic retracting device whose center is supported by the tip of a rod of the hydraulic retracting device and whose one end is supported by a rod of the hydraulic retracting device. The main boom is equipped with a main boom supported by the mast, and a top boom whose base end is supported by the main boom and whose distal end supports a lifting device via a rope, and the rod of the hydraulic retraction device is horizontally operated, and the top boom is supported by the main boom. and a lifting load swing control device for a horizontal retractable crane that horizontally moves a suspended load via the top boom, comprising: a displacement detector for detecting rod displacement of the hydraulic retracting device; and a displacement detector for detecting the elevation angle of the main boom. The controller is provided with an elevation angle detector for detecting the elevation angle and a deflection angle detector for detecting the deflection angle of the suspended load, and the controller inputs the detection signals of the respective detectors, and receives the detection signal of the rod displacement and the main deflection angle. Using the detected signal of the elevation angle of the boom, an inverse transfer function is calculated to convert the horizontal speed of the tip of the top boom to the speed of the rod of the hydraulic retracting device, and the detected signal of the swing angle of the suspended load is differentiated to calculate the suspended load. find the difference between the speed command of the hydraulic retracting device and the value obtained by multiplying the inverse transfer function by the swing angular velocity of the suspended load, and issue the control command to eliminate the difference. A hanging load swing control device for a horizontal retractable crane characterized by outputting to a hydraulic retracting device. 2. The displacement detector and the elevation angle detector are
Claim 1: The controller comprises a converter for converting each detected electric signal into a binary code digital signal, and the controller comprises a converter for converting the digital signal to an arbitrary electric signal level.
A hanging load swing control device for a horizontal retractable crane as described in 2.