JPH0710469A - Control device for vertical dynamic lift-off of crane - Google Patents

Abstract

PURPOSE:To surely prevent oscillation of cargo by correcting a variation amount in working radius, caused by deflection of a boom which is incorporated in a crane and which is raised and lowered, and extended and retracted by a hydraulic mechanism, during dynamic lift-off, and by adjusting the descent speed of a wire, synchronously with the correction. CONSTITUTION:A crane vehicle comprises an instruction signal transmitter 5 for delivering a control initiating signal S1 and a control ending signal S2 upon initial dynamic lift-off for lifting up cargo, a load sensor 61 for detecting a load of the lifted cargo, an attitude detecting sensor 6 composed of a boom length sensor 62 and a boom angle sensor 63, a controller 7 receiving signals from the sensors, and having a working radius adjustment control means 72, a wire ascent speed control means 73 and the like, for carrying out computation of a correction for a variation in the working radius of the boom so as to prevent oscillation of the cargo due to deflection of the boom during dynamic lift-off, and computation for obtaining an ascent speed of a wind-up wire, synchronous with the correction, and for controlling a hydraulic mechanism in accordance with the result of the computation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crane having a hoistable boom, and relates to a so-called vertical ground cutting control device for a crane, which is applied for vertically lifting a suspended load.

[0002]

2. Description of the Related Art A crane having a boom is usually a base having a built-in drive mechanism, a boom pivotally supported about a horizontal axis of the base, and a boom suspended from the tip of the boom. It is basically composed of a winding wire. In some booms, a jib is provided at the tip of the boom so that the boom can be extended and contracted to adjust the length of the entire boom.

[0003] Such a boom is constructed so that it can be arbitrarily rotated (raised and lowered) about a horizontal axis by driving a drive mechanism built in a base, and is connected to the drive mechanism. By rotating the drum forward and backward, the wire wound around the drum is moved up and down from the tip of the boom. A hook is attached to the tip of the hoisting wire via a pulley, and a hanging load is hung on the hook to hoist it.

By the way, normally, the suspended load is initially placed on the ground level, and the suspended load placed on this ground is lifted by rotating the boom upward about the horizontal axis. To do this, first place the boom tip just above the suspended load, then hang the hoisting wire, and hang the suspended load on the hook to pull up the wire. The load is gradually transmitted to the tip of the boom, and the tip of the boom gradually bends downward as the load increases.

Then, at the time of so-called ground cutting immediately after the suspended load is lifted upward from the ground, the above deflection is maximized, and the tip end portion of the boom is in a state of protruding considerably forward from the initial position. Therefore, the hoisting wire that connects the tip of the boom and the suspended load is formed with an inclination corresponding to the above protrusion amount, and when hoisting the wire in such a state,
Due to the above-mentioned inclination, a so-called load swing phenomenon occurs in which the suspended load swings back and forth when cutting the ground.

In order to prevent such a swinging phenomenon, a conventional operator must perform an operation requiring skill such as making the ground cutting speed extremely slow, or the ground in front of the tip position of the boom in advance. Adjustments such as placing a suspended load on the level were performed.However, such an operation is extremely complicated, and the degree of adjustment varies depending on the weight of the suspended load. The reality is that the shake phenomenon cannot be prevented.

Under such circumstances, various researches have recently been made on control systems for automatically suppressing the vibration of the suspended load during the above-mentioned ground cutting operation of the crane. For example, the one disclosed in Japanese Patent Application Laid-Open No. 1-256496 detects the increase amount (ΔR) of the working radius of the boom each time due to the bending of the boom caused by the load gradually applied to the tip of the boom during ground cutting. It is calculated from the elevation angle (θ) of the boom, the length (L) of the boom, and the load (F) applied to the boom on the basis of a preset relational expression ΔR = f (θ, L, F) The boom is raised so that the predicted work radius increase amount (ΔR) becomes 0, and the wire is wound up.

Then, the actual working radius R _x when actually lifting a small amount and the initial working radius (working radius immediately below the boom tip end portion) R _x0 are compared and calculated, and R _x ≧ R when _x0, that is, configured so that the actual working radius (R _x) is to Okoshiossha initial working radius (R _x0) by further predetermined small amount only when greater than boom towards correcting the angle of elevation of the boom ing.

By performing such control, when the wire hanging from the tip of the boom is rolled up to cut the suspended load, the working radius (R _x ) due to the bending of the boom
It is explained that the increase amount (ΔR) of is constantly corrected, and the load swing of the suspended load at the time of ground cutting is effectively suppressed.

In the control method for ground cutting disclosed in Japanese Patent Laid-Open No. 1-256496, the actual working radius (R _x ) is corrected to the initial working radius (R _x0 ) by adjusting the boom elevation angle. As described above, JP-A 1-2
Japanese Patent No. 56497 discloses that the actual working radius (R _x ) is corrected to the initial working radius (R _{x 0} ) by expanding and contracting the boom. The two differ only in the method of correction, namely, the rotation of the boom and the expansion and contraction of the boom, but the technical ideas regarding the basic control are exactly the same.

[0011]

The above-mentioned Japanese Unexamined Patent Application Publication No.
In the devices disclosed in Japanese Patent Application Laid-Open No. 2566496 and Japanese Patent Application Laid-Open No. 1-256497, the above (R _x ≧
When the condition R _x0 ) is satisfied, it is detected, and the boom is raised in order to shorten the working radius by a length commensurate with the amount of increase in the working radius of the boom due to the bending at that time (Japanese Patent Laid-Open No. 1-256496). No.)
However, a predetermined signal is transmitted to the boom drive mechanism.

Further, in general, the drive mechanism which receives the signal supplies a current having a strength corresponding to the content of the signal to the electric motor, and the electric motor drives according to the strength of the current. The boom is moved via a hydraulic mechanism.

However, when the amount of increase in the working radius of the boom is very small, only a small amount of current is supplied to the electric motor correspondingly, and the driving force of the electric motor is accordingly small. If the driving force of the electric motor is small, it is not possible to exert enough force to move the boom, so the boom cannot move in the end,
The current set position is maintained until the boom flexes considerably and the working radius increase amount reaches a predetermined length. Such a characteristic that the target does not operate unless the current reaches a predetermined current value is called a non-linear characteristic, and a range of the current value at which the target does not operate is called a dead zone. The dead zone range is proportional to the load of the boom, and the dead zone range expands as the load increases.

Therefore, since the work radius is further increased and the intensity of the current is increased to a certain extent in proportion to the increase in the work radius, the electric motor is driven to move the boom, which causes a slight movement of the boom. On the other hand, not only the control does not work at all, but when it works, a response delay occurs, and eventually the increase in the working radius due to the bending of the boom cannot be offset within the several seconds required for ground cutting, and as a result, the control is performed. Despite this, it was not possible to effectively suppress the swinging of the load when digging.

In summary, in the conventional control method for vertical ground cutting, even if various measures are taken, the presence of the dead zone causes the suspended load to start from the start of suspension until it leaves the ground level. It was not possible to effectively suppress the shake of the load that occurred in an extremely short time.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a vertical ground-cutting control device for a crane, in which the vibration of the load at the time of ground cutting is effectively suppressed. There is.

[0017]

According to a first aspect of the present invention, there is provided a vertical ground cutting control device for a crane, wherein a boom is constructed so that it can be undulated and extended and retracted by the operation of a hydraulic mechanism, and the operation is performed from the tip of the boom. A vertical grounding control device for a crane, in which a wire that can be lifted up and down by a wire is provided, and a hanging load is hung at the tip of this wire to wind the wire to lift the hanging load. The controller is provided with a controller that controls the boom undulation or expansion and contraction, and the wire rising speed, and this controller corrects the amount of change in the working radius due to the bending of the boom during ground cutting, and In synchronization with this correction, a command signal for correcting the wire rising speed to the set rising speed is transmitted to the hydraulic mechanism. It is intended to.

According to a second aspect of the present invention, there is provided a vertical ground cutting control device for a crane, wherein a wire vertically hangs from a tip end portion of a boom which is constructed so that it can be undulated and expanded and contracted by the operation of the first hydraulic system. A vertical ground cutting control device for a crane configured to suspend a suspended load and wind the wire to suspend the suspended load, and a command signal transmission for transmitting a control start command signal and a control end command signal. And a boom attitude detection sensor that detects the attitude of the boom and transmits the detected value, and operates when the control start command signal is input from the command signal transmitter and outputs the control end command signal. A controller for stopping is provided, and when the control start command signal is input to the controller, the controller responds to the detection value input from the boom attitude detection sensor. There is provided work radius correction control means for transmitting a work radius correction command signal for correcting the work radius of the first hydraulic system to achieve vertical ground cutting, and the work radius correction command signal includes the first radius. It is characterized in that a bias value having a magnitude necessary for the hydraulic system to operate at a minimum is added in advance.

According to a third aspect of the present invention, in the vertical ground cutting control device for a crane, the second hydraulic pressure is hanged vertically from the tip of a boom which can be raised and lowered and expanded and contracted by the operation of the first hydraulic system. A vertical ground-cutting control device for a crane configured to suspend a suspended load at the tip of a wire configured to be movable up and down by the operation of a system, and to suspend the suspended load by winding the wire, A command signal transmitter that transmits a control start command signal and a control end command signal by an operator's operation, and a boom posture detection sensor that detects the boom posture and transmits this detection value are provided. The controller is provided with a controller that operates when a start command signal is input and stops when a control end command signal is transmitted. No. is input, a work radius correction command signal is sent to the first hydraulic system to correct the work radius of the boom so as to achieve vertical ground cutting according to the detection value input from the boom attitude detection sensor. Work radius correction control means, and wire raising speed for transmitting a wire control signal to the second hydraulic system to realize a set wire raising speed by subtracting the boom rising speed at the time of ground cutting It is characterized in that a control means is provided.

According to a fourth aspect of the present invention, there is provided a vertical ground cutting control device for a crane according to the second or third aspect, in which the boom attitude detecting sensor applies a load of a suspended load applied to the boom. A load sensor for detecting,
It is characterized by comprising a boom length sensor for detecting a boom length and a boom angle sensor for detecting a boom angle.

According to a fifth aspect of the present invention, there is provided a vertical ground cutting control device for a crane according to the second or third aspect, wherein the boom attitude detecting sensor detects a boom length. It is characterized by comprising a long sensor and a boom angle sensor for detecting a boom angle.

[0022]

According to the vertical ground cutting control device for a crane according to the first aspect, the control device is provided with a controller for controlling the ups and downs of the boom and the expansion and contraction of the boom, and the lifting speed of the wire. It is configured to correct the amount of change in the working radius due to the bending of the boom during ground cutting and to send a command signal to the hydraulic mechanism in synchronization with this correction to correct the wire rising speed to the set rising speed. Therefore, the hydraulic mechanism that receives the command signal from the controller operates to correct the amount of change in the working radius due to the bending of the boom, and to adjust the wire rising speed to the set rising speed in synchronization with this correction. As a result, the load applied to the boom during ground cutting gradually increases, and the boom gradually bends with this increase, even if the working radius increases due to this bending. Fixed in the seat, always wire toward the distal end of the boom to the suspended load are in a state of hanging down vertically, load pendulum is effectively prevented.

At the same time, since the winding speed of the wire is prevented from being deviated from the set value due to the movement of the boom tip, the synergistic effect with the correction of the working radius of the boom makes it possible to more reliably swing the load at the time of ground cutting. Can be effectively suppressed.

According to the vertical ground-cutting control device for a crane described in claim 2, the operator appropriately operates the command signal transmitter to input the control command signal or the control end signal to the controller during the ground cutting operation. The intervention of the controller can be arbitrarily selected during the ground cutting operation of the crane. That is, when the controller is not used, the operator can lift the suspended load by the conventional manual operation operation, and when the controller is interposed, entrust the controller with the lifting operation only while the controller is interposed. Therefore, manual and automatic switching can be arbitrarily performed according to the situation of the suspended load, and a more appropriate ground cutting operation that does not cause load shake can be realized.

Then, when the control command signal is input to the controller to operate it, the controller performs a predetermined calculation from the detected value relating to the boom posture which is input from the boom posture detection sensor one by one, and determines the working radius of the boom. Modify so that vertical ground cutting is realized (specifically, modify so as to elevate or retract the boom so as to eliminate the increase in boom working radius that has increased as a result of bending under the load of the suspended load) ) Since the working radius correction command signal is transmitted to the first hydraulic system, the first hydraulic system operates based on this command signal, the working radius of the boom is corrected, and the ground cutting operation without load shake is performed.

At this time, since the work radius correction command signal is preliminarily added with a bias value of a magnitude required for the first hydraulic system to operate at a minimum, the signal is transmitted. Regardless, the non-operation of the first hydraulic mechanism due to the small value of the signal is avoided, and the responsiveness of the control is improved so that the first hydraulic mechanism always operates regardless of the small value of the signal. As a result, the swinging of the load at the time of ground cutting is reliably suppressed.

According to the vertical ground cutting control device for a crane described in claim 3, in addition to the operation for correcting the working radius of the boom by the control device according to claim 2, the wire winding speed is appropriately controlled, The shake of the load at the time of ground cutting is reliably suppressed.

That is, when the control start command signal is input to the controller and the controller is operated, the wire lifting speed control means of the controller performs a predetermined calculation from the detected value relating to the boom posture which is input one by one from the boom posture detection sensor. Then, the rising speed of the boom tip is calculated, this rising speed is subtracted from the preset wire rising speed by an input operation by the operator, etc., and the wire control signal is used to realize the subtracted winding speed. Is transmitted to the second hydraulic system.

Accordingly, the second hydraulic system receiving this takes up the wire at the take-up speed instructed by the wire control signal and hoists the suspended load, so that the load due to the excessive rising speed of the wire during ground cutting. It is possible to prevent a sudden increase in the load, and effectively suppress the swing of the suspended load.

According to the vertical ground cutting control device for a crane described in claim 4, the boom posture detection sensor includes a load sensor for detecting a load of a suspended load applied to the boom, and a boom length sensor for detecting a length of the boom. , A boom angle sensor for detecting the boom angle, a predetermined calculation is performed based on each of the detection values detected by the boom attitude detection sensor to properly perform the working radius correction command signal, A wire control signal and a rising speed correction command signal can be obtained.

According to the vertical ground-cutting control device for a crane described in claim 5, the boom posture detection sensor is composed of a boom length sensor for detecting a boom length and a boom angle sensor for detecting a boom angle. Therefore, the load sensor that detects the load of the suspended load applied to the boom is omitted,
The equipment cost is reduced accordingly. The load of the suspended load can be calculated using a predetermined relational expression from changes in the boom length and the boom angle for each minute time.

[0032]

1 is a schematic side view illustrating a crane to which a control device of the present invention is applied. As shown in this figure,
In the present embodiment, the crane 10 includes the basic vehicle body 1,
An upper revolving structure 2 which is rotatably supported on the upper part of the basic vehicle body 1 about a vertical axis 21 on a horizontal plane, and the upper revolving structure 2
The boom 3 is rotatably supported on a vertical plane about a horizontal shaft 31, and a hoisting wire 4 is hung from the tip of the boom 3.

Inside the basic vehicle body 1, a hydraulic mechanism 8 for driving each driving portion of the crane 10 is installed. The hydraulic mechanism 8 is provided with a first hydraulic system 81 for hoisting the boom 3 and a second hydraulic system 82 for raising and lowering the hoisting wire 4. A hydraulic cylinder 32 is attached to the base end of the boom 3, and hydraulic pressure is supplied to the hydraulic cylinder 32 via a first hydraulic system 81. The boom 3 is undulated by appropriately adjusting the hydraulic pressure supply amount.

The boom 3 includes the first boom 3 from the base end side.
0a, the second boom 30b and the third boom 30c are slidably fitted to each other. The booms 30a, 30b, 30c are supplied with hydraulic pressure from the first hydraulic system 81 and move forward and backward in the extending direction of the boom 3, whereby the length of the boom 3 expands and contracts.

Two of the hoisting wires 4 are the boom 3
Is hung from the tip of the pulley 41, and is wrapped around the pulley 41 at the folded back portion of the lower end. This pulley 41 has a hook 42
Is attached, and the suspended load W is attached to this hook. The hoisting wire 4 is inserted into the center hole of the cylindrical boom 3, one of them is fixed and the other is wound on a drum (not shown). By rotating this drum forward and backward through the second hydraulic system 82, the hook 42 provided at the tip of the winding wire 4 can be moved up and down.

FIG. 2 is an explanatory view exemplifying a bending state of the boom at the time of so-called ground cutting at the beginning of lifting the suspended load W placed on the mounting surface G at the ground level. As shown in this figure, in order to lift the suspended load W by the crane 10, first, the boom W is placed so that the center of gravity W1 of the suspended load W placed on the mounting surface G and the hoisting wire 4 are located on the same vertical line. 3 is rotated about the horizontal axis 31 to set a predetermined boom angle (θ _B ). The hoisting wire 4 is hung from the tip of the boom 3 having this angle set. Then, the suspended load W is attached to the hook 42.

Since the hoisting load W is mounted on the hoisting wire 4 so that the center of gravity W1 of the hoisting load W is located at the lower end of the hoisting wire 4 hanging down as described above, the second hydraulic system 82 is connected to the second hydraulic system 82. When the hoisting wire 4 is wound up by operating the hoisting wire W, the hoisting load W should rise without causing the so-called hoisting swing which swings to the left and right. Winding wire 4 before leaving
As the tension of the hoisting wire 4 increases, the boom 3 changes from the initial state shown by the solid line to the bent state shown by the chain double-dashed line.
Becomes slanted from the hanging state as shown by the chain double-dashed line. That is, the work radius R of the boom 3 is increased by the work radius increase amount ΔR to (R + ΔR).

At the moment when the tension of the hoisting wire 4 reaches the gravity of the suspended load W and the suspended load W is separated from the mounting surface G,
As indicated by the one-dot chain line, the suspended load W moves toward a vertical line that hangs from the distal end of the bent boom 3, and thereafter swings left and right with the vertical line as the center line. The present invention provides a control device that controls such that the swing of the suspended load W does not occur during such vertical ground cutting.

An embodiment of the vertical ground cutting control device for a crane according to the present invention will be described in detail below with reference to FIG. Figure 3
FIG. 3 is a block diagram showing an example of a control system of the control device according to the present invention. As shown in this figure, the control device C includes a command signal transmitter 5 for an operator to arbitrarily perform an input operation, a boom posture detection sensor 6 for detecting the posture of the boom 3, and the command signal transmitter 5 described above. Of the boom posture detection sensor 6 and the controller 7 for calculating the posture of the boom 3 in which load shake does not occur at the time of ground cutting based on these signals. The hydraulic mechanism 8 operates to rotate the boom 3 around the horizontal axis 31 and to extend and contract the boom 3 by receiving a signal based on the calculation result.

The command signal transmitter 5 is provided with various operation levers and operation buttons so that an operator can operate the crane 10 by operating the operation levers and the like. The control start lever 51 for transmitting the control start command signal S1 for starting the control at the time of ground cutting by the controller 7 and the control end command signal S2 for ending the control are transmitted into the lever or the like. A control end lever 52 is provided.

The control start command signal S1 and the control end command signal S2 are input to the controller 7 by operating these levers 51 and 52.
In addition to these levers 51 and 52, a wire lever 53 for manually winding and winding the winding wire 4 is manually operated.
The wire drive signal S3 is transmitted by operating the wire lever 53.

In addition to the levers described above, conventional levers for normal crane operation (such as levers for manually raising and lowering the boom 3 and rotating it horizontally around the vertical axis 21) In general, such a normal lever is also provided with a control start lever 5
1 until the control start command signal S1 is transmitted and then the control end lever 52 transmits the control end command signal S2, that is, while the vertical ground cutting operation is entrusted to the control device C during ground cutting. However, the effect is not reached.

The posture detecting sensor 6 includes a load sensor 61 for detecting the load of the suspended load W which changes every moment when cutting the ground, a boom length sensor 62 for detecting the length of the boom 3, and an angle of the base portion of the boom 3. And a boom angle sensor 63 for detecting

The load sensor 61 detects the hydraulic pressure of the hydraulic cylinder 32 attached to the base end portion of the boom 3 at every minute time, so that the boom 3 due to the suspended load W changing every moment.
Is designed to detect the load of the boom length sensor 6
In the reference numeral 2, the length of the boom 3 is taken out from the mechanism for expanding and contracting the boom 3 provided in the basic vehicle body 1.
In addition, the boom angle sensor 63 detects the angle of the boom 3 by a signal transmitted from an angle detector such as a rotary encoder to the horizontal shaft 31 provided at the base end of the boom 3. These attitude detection sensors 6
Detected by the load sensor 61, that is, the load signal T from the load sensor 61 and the boom length signal L from the boom length sensor 62.
And a boom angle signal θ _B from the boom angle sensor 63
Are input to the subsequent controller 7, respectively.

The controller 7 calculates based on various signals input from the command signal transmitter 5 and the attitude detection sensor 6 to correct the working radius of the boom 3 so as to prevent the swing of the load, and the hoisting wire 4. Is a control device that calculates the ascending speed of the wire and sends a predetermined control signal from the results of these operations. In the controller 7, an input device 71, a working radius correction control means 72, and a wire ascending speed control means 73 and a signal processing means 74 are provided.

A control start command signal S1 and a control end command signal S2 are input from the command signal transmitter 5 to the input device 71, and the suspended load signal T, the boom length signal L and the boom are input from the attitude detection sensor 6. The angle signals θ _B are input respectively. These input signals are processed, for example, by converting an analog signal into a digital signal so that the subsequent work radius correction control means 72 and the wire rising speed control means 73 in the input device 71 can perform predetermined arithmetic processing. Done.

In the input device 71, the control start command signal S1 and the control end command signal S2 from the command signal transmitter 5 are the suspended load signal T, the boom length signal L and the boom from the attitude detection sensor 6. The angle signal θ _B is prioritized, and the control start lever 51 is operated to input the control start command signal S1 and then the control end lever 52 is operated to input the control end command signal S2. The signal from the posture detection sensor 6 is transmitted only to the following work radius correction control means 72 and wire rising speed control means 73, and the control device C relating to ground cutting
Is controlled by.

In the working radius correction control means 72, the suspended load signal T input from the load sensor 61 via the input device 71, the boom length signal L input from the fastening state determination means 62, and the boom Based on the boom angle signal θ _B input from the angle sensor 63, the boom target angle at the time of ground cutting is calculated, the calculated target angle is compared with the current actual angle, and both are calculated. The boom hoisting control signal is calculated according to the difference between the two.

With respect to the boom target angle, a calculation formula for calculating the boom target angle θ _BT , which is input in advance in the work radius correction control means 72, is calculated by θ _BT = f (T, L, θ _B0 ). It is calculated. Here, T is the value of the suspended load detected by the load sensor 61, L is the value of the boom length detected by the boom length sensor 62, and θ _B0 is the initial value of the boom angle detected by the boom angle sensor 63. .

Although the suspended load T is included in the factors for calculating θ _BT in the present embodiment, the suspended load T
Can be expressed as a function of the other boom length L and the boom angle θ _B , so that the boom length L and the boom angle θ _B detected even if the load sensor 61 is not provided and the suspended load T is not detected. It can be obtained by calculation from and. By doing so, the installation cost of the load sensor 61 can be reduced.

The boom target angle θ _BT is _calculated as shown in FIG.
It is an angle in a state of being rotated counterclockwise around the horizontal axis 31 so as to offset the increased working radius ΔR of the boom 3 at the time of ground cutting shown in FIG.

Then, the calculated boom target angle θ
_BT and currently is compared with the boom angle theta _B that now the boom angle sensor 63 is detecting, Δθ _B = _{θ BT} -θ _B by a predetermined control gain is multiplied to the calculated [Delta] [theta] _B by initials command signal ( Control signal).

By the way, in the present invention, the initial command signal obtained as described above is not transmitted to the following hydraulic mechanism 8 as it is, but is converted into a signal for the hydraulic mechanism 8 to immediately respond. The so-called non-linear compensation is performed. This non-linear compensation is important. The non-linear compensation in the present invention will be described below.

FIG. 4 is a graph for explaining the range of the dead zone in which the boom does not respond to the command signal (input current) supplied to the hydraulic mechanism, and (a) is the input current value introduced to the hydraulic mechanism. And the boom rotation (expansion / contraction) speed, showing that the dead zone exists in the current value range of i _{1 to} i ₂ . (B) shows the relationship between the load and the dead zone when the boom rotation (expansion / contraction) speed is 0, and indicates that the dead zone becomes wider as the load increases.

FIG. 5 is a graph for explaining that the command signal (input current) supplied to the hydraulic mechanism is first converted by the non-linear compensation circuit to eliminate the dead zone where the boom does not respond. (A) shows the relationship between the input current and the output current, and (b) shows the relationship between the load and the output current.

First, as shown in FIG.
The initial command signal obtained by multiplying θ _B by a predetermined control gain expresses the magnitude of the current strength. In addition, the flow direction of the current is reversed at the intersection of the graphs, and the boom 3 is on the horizontal axis 31 on the left side of the intersection.
The current is for rotating clockwise in the clockwise direction, and the current on the right side of the intersection is for rotating in the counterclockwise direction.

At such a current, i ₁ ~
The range of i _{2 is} a range in which the boom 3 does not operate at all even though the current is supplied, and this range is the load T
And the same load T as shown in (b) of FIG.
The above range increases with increasing.
Such a characteristic that the initial command signal does not generate any effect within a predetermined range is called a non-linear characteristic.

In the present invention, a method called non-linear compensation is adopted in order to eliminate such non-linear characteristics of the initial command signal, and this non-linear compensation realizes accurate control without response delay. For this non-linear compensation, the working radius correction control means 72 is provided with a non-linear compensation circuit (not shown). The nonlinear compensating circuit, when the current value of the inputted initial command signal (input current) is within the range of the i ₁ through i ₂ adds the bias of i ₁ or i ₂ to the current value, the added It has a function to output the generated current as an output current.

FIG. 5 shows this fact.
In (a), the horizontal axis represents the output current corresponding to the input current corresponding to the initial command signal set on the vertical axis, and this output current is the sum of the bias components i ₁ and i ₂ i It is output from ₃ and i ₄ . That is, as long as the input current is not 0, a current larger than the minimum current values i ₃ and i ₄ required for the boom 3 to operate is output. Since the boom 3 operates, the responsiveness becomes extremely good. As for the output current, as shown in (b) of FIG. 5, the absolute values of i ₃ and i ₄ increase with the increase of the suspended load T corresponding to the graph of (b) in FIG. Is set to.

In this way, the work radius correction command signal S4 which is the output current is transmitted from the work radius correction control means 72.

On the other hand, in the wire raising speed control means 73, the suspended load signal T input from the load sensor 61 via the input device 71 and the boom length signal L input from the fastening state determination means 62, Based on the boom angle signal θ _B input from the boom angle sensor 63, the distance between the boom tip 3a and the mounting surface G at the time of ground cutting, that is, the boom tip height H is based on the following relational expression. Is calculated.

H = g (T, L, θ _B ) Then, this H is differentiated with respect to time to calculate the rising speed of the boom tip portion 3a. Specifically, the boom tip height H is calculated every minute, and the difference in the obtained values of H is calculated one by one, and this calculation result is divided by the set minute time, and at that time. Ascending speed d of the boom tip 3a
H / dt is obtained.

By the way, in the control device C, basically, the lifting operation of the suspended load W by winding the wire 4 is performed by the operator operating the wire lever 53 of the command signal transmitter 5. ing. Then, the wire 4 is driven by the wire drive signal S3.
Winding and lowering, and their speeds are set, and the wire drive signal S3 is input to the signal processing means 74.

In the present invention, the winding speed of the wire 4 is reduced by subtracting the rising speed dH / dt of the boom tip 3a from the rising speed of the hoisting wire 4 set by the wire drive signal S3. Since the wire 4 is calculated and wound up at the calculated winding speed, the actual rising speed of the suspended load W is the speed set by the operator using the wire lever 53 of the command signal transmitter 5. is there.

The winding speed of the wire 4 is adopted as a wire control signal (raising speed command signal) S5, and is input to the hydraulic mechanism 8 via the signal processing means 74.

The signal processing means 74 is a kind of repeater, and the work radius correction command signal S4 input from the work radius correction control means 72 is multiplied by a predetermined control gain to obtain a work radius for hydraulic mechanism control. It becomes the correction command signal S4 ', and the wire control signal S5 indicating the lifting speed dH / dt of the boom tip portion 3a input from the wire lifting speed control means 73 is the subtraction of the lifting speed of the wire 4 input from the wire lever 53. The signal of the wire winding speed obtained as a result is multiplied by a predetermined control gain to become a wire control signal S5 ′, which is input to the subsequent hydraulic mechanism 8.

Therefore, if the operator operates the wire lever 53 to set the desired lifting speed of the suspended load W during the ground cutting operation, the increase in the lifting speed due to the raising of the boom 3 during the ground cutting is corrected. , The suspended load W always desired by the operator
As a result, the ascending speed can be obtained, and the shake of the load due to the sudden increase of the load can be effectively suppressed.

The hydraulic mechanism 8 is provided with a known first hydraulic system 81 for hoisting the boom 3 and a second hydraulic system 82 for hoisting the wire 4. The first hydraulic system 81 includes an electromagnetic proportional pressure reducing valve 81a to which the work radius correction command signal S4 'is input, a boom hoisting extension / contraction control valve 81b which is opened / closed by the operation of the pressure reducing valve 81a, and the control valve 8
It is composed of a hydraulic motor 81c driven via 1b.

The electromagnetic proportional pressure reducing valve 81a outputs a hydraulic signal (pilot pressure) corresponding to the working radius correction command signal S4 'to the boom hoisting extension / contraction control valve 81b. 81b has a spool stroke controlled in accordance with the pilot pressure, and the amount of inflow oil supplied to the hydraulic motor 81c from a hydraulic source (not shown) is controlled by controlling the spool stroke to obtain a predetermined rotational speed of the hydraulic motor 81c. It is designed to be used.

The second hydraulic system 82 has an electromagnetic proportional pressure reducing valve 82a to which the wire control signal S5 'is input.
And a wire winding control valve 82b which is opened and closed by the operation of the pressure reducing valve 82a, and a hydraulic motor 82c which is driven via the control valve 82b.

The electromagnetic proportional pressure reducing valve 82a receives a hydraulic pressure signal (pilot pressure) corresponding to the wire control signal S5 '.
Is output to the wire winding control valve 82b. As a result, the control valve 82b
Controls the spool stroke according to the pilot pressure, and controls the spool stroke to control the amount of inflow oil supplied from the hydraulic power source (not shown) to the hydraulic motor 82c to obtain a predetermined rotation speed of the hydraulic motor 82c. It is like this.

The rotational drive of both hydraulic motors 81c and 82c is transmitted to the crane mechanical system 9 which constitutes the drive mechanism of the crane 10, and the boom 3 is controlled by the horizontal axis of the crane 3 via the crane mechanical system 9. The winding wire 4 turns up and down around 31 to move up and down.

Since the vertical ground cutting control device for a crane of the present invention is constructed as described above, when the operator turns on the control start lever 51 of the command signal transmitter 5,
The control start command signal S1 is input from the control start lever 51 to the input device 71 of the controller 7, and the operation of the crane 10 is switched from the manual operation mode to the automatic control mode by the input device 71.

On the other hand, from the attitude detection sensor 6, the suspended load signal T detected by the load sensor 61, the boom length signal L detected by the attitude detection sensor 6, and the boom angle sensor 6 are detected.
The boom angle signal θ _B detected by 3 is transmitted and input to the work radius correction control means 72 and the wire rising speed control means 73 via the input device 71.

First, the working radius correction control means 7
2, the target angle of the boom is calculated based on the suspended load signal T, the boom length signal L, and the boom angle signal θ _B detected by the attitude detection sensor 6, as described above, and the target angle is calculated. And a deviation from the actual angle are calculated, and a boom hoisting control signal is calculated based on these calculation results. Finally, nonlinear compensation is performed and a working radius correction command signal S4 is transmitted to the signal processing means 74. It

In parallel with the formation of the control signal in the work radius correction control means 72, the wire lifting speed control means 73 uses the suspended load signal T, the boom length signal L and the boom angle signal θ _B as a basis. As described above in detail, the vertical speed of the boom tip portion 3a that is currently moving is calculated.

In the signal processing means 74, a predetermined signal conversion is performed to obtain a working radius correction command signal S4 'and a wire control signal S5' for the hydraulic mechanism 8, and these signals are used as the succeeding hydraulic mechanism 8. Entered in. The wire control signal S5 'is obtained by subtracting the vertical speed of the boom tip portion 3a from the rising speed of the wire 4 set by the operator.

The first hydraulic system 81 in the hydraulic mechanism 8
Obtains the working radius correction command signal S4 ', and the electromagnetic proportional pressure reducing valve 81a and the boom hoisting extension / contraction control valve 8
The hydraulic motor 81c is rotationally driven in a controlled state via 1b, and this rotational drive is transmitted to the crane mechanical system 9, and the boom 3 is deflected by the load of the suspended load W by the drive of the crane mechanical system 9. Drive to elevate (reduce) to correct the increase of.

On the other hand, the second hydraulic system 82 in the hydraulic mechanism 8
Is independent of the control of the first hydraulic system 81,
At the same time, it is operated by the wire control signal S5 ', and the hydraulic motor 82c is rotationally driven via the electromagnetic proportional pressure reducing valve 82a and the wire winding control valve 82b to adjust the rising speed of the winding wire 4.

Therefore, the vertical ground cutting operation is realized by the synergistic action of the first hydraulic system 81 and the second hydraulic system 82, and the swing of the suspended load W is effectively suppressed. Then, when the ground cutting of the suspended load W is completed, the control end lever 52 of the command signal transmitter 5 is completed.
Is operated to terminate the ground cutting control by the controller 7, and thereafter the normal manual operation by the wire lever 53 is performed to lift the suspended load W. Even if an interrupt is made by the wire lever 53 before the control of the controller 7 is completed by the control end lever 52, the interrupt is rejected by the signal processing means 74, so the controller 7 is controlled. The operator's over-action is effectively blocked when the ground is being cut.

As described above, when the vertical ground cutting control device for a crane according to the present invention is applied, the operator of the crane 10 vertically hangs down from the tip of the boom 3 when performing the ground cutting operation of a suspended load. Winding wire 4 and hook 4
After hanging the suspended load W via 2, the control start lever 51 of the command signal transmitter 5 is turned ON, and the operation of winding the wire 4 is performed. After that, the boom 3 does not shake automatically. As described above, the hoisting wire 4 is hoisted in a state in which the swinging of the hoisting wire 4 does not occur in response to the ups and downs of the boom 3, that is, in a state in which the hoisting speed does not cause over-action, and the swinging of the load during ground cutting is effectively suppressed. Of.

In the example of the control system shown in FIG. 3 described in detail above, the command signal transmitter 5 is of the type operated by the operator, but the command signal transmitter 5 of the present invention uses this type. It is not limited to the type operated by the operator as described above, and may be previously incorporated in the controller 7 as an electronic circuit.

FIG. 6 is an explanatory view illustrating a state in which the control device of the present invention is applied to a tower crane or a jib crane. As shown in this figure, the present invention is not limited to the crane (rough terrain crane) 10 in which only the boom 3 shown in FIG. 1 moves, but can be applied to a multi-joint crane 10 'such as a tower crane or a jib crane. . When applying the control device of the present invention to the multi-joint crane 10 ′, the height of the tower 30 (tower length) is H _T , the tower angle is θ _T , the raising angle of the boom 3 is θ _j , and the boom 3 is. If the length (boom length) is L _j , the boom 3
Let L '= √ {H _T if the distance between the tip end of the tower and the base end of the tower 30 is L'and the angle between the dotted line and the horizontal line is L'. ² + L _j ² + 2H _T · L _j (sin θ _T · si
_{nθ j + cosθ T · cosθ j} )} θ '= arctan {H T · sinθ T + L j · sin
_{θ j) / (H T ·} cosθ T + L j · cosθ j) relationship} is established. Therefore, assuming that this L'is the length L of the boom 3 shown in FIG. 1, θ'is the same boom angle θ.
_If the tower length H _T , the tower angle θ _T , the elevation angle θ _j of the boom 3 and the boom length L _j are detected by setting _B = L ′ θ _B = θ ′, the present invention is realized. Similarly, vertical ground cutting control of the multi-joint crane 10 'can be performed.

[0084]

As described above, according to the first aspect of the present invention.
The vertical ground-cutting control device for a crane described above is provided with a boom that is configured to be undulated and retracted by the operation of a hydraulic mechanism, and a wire that is vertically hung from the tip of the boom by the above operation. A vertical ground cutting control device for a crane configured to hang a suspended load at the tip of the wire and to wind the wire, and the control device includes undulation or expansion and contraction of the boom, A controller for controlling the rising speed of the wire is provided, and this controller corrects the amount of change in the working radius due to the bending of the boom during ground cutting, and
In synchronization with this correction, a command signal for correcting the wire rising speed to the set rising speed is transmitted to the hydraulic mechanism.

Accordingly, the hydraulic mechanism which receives the command signal from the controller corrects the amount of change in the working radius due to the bending of the boom, and, in synchronization with this correction, corrects the wire rising speed to the set rising speed. The load applied to the boom during ground cutting gradually increases, and the boom flexes gradually with this increase, and even if the working radius increases due to this increase, the boom is immediately corrected, and the load is always applied from the tip of the boom. The wire vertically hangs down toward the wire, effectively preventing the swinging of the load.

At the same time, the winding speed of the wire is prevented from being deviated from the set value due to the movement of the tip of the boom. Therefore, the synergistic effect with the correction of the working radius of the boom makes the load swing at the time of ground cutting more reliable. Can be effectively suppressed.

According to a second aspect of the present invention, there is provided a vertical ground-cutting control device for a crane, wherein a wire vertically hangs from a tip of a boom which is constructed so that it can be undulated and expanded and contracted by the operation of a first hydraulic system. A vertical ground cutting control device for a crane configured to suspend a suspended load and wind the wire to suspend the suspended load, and a command signal transmission for transmitting a control start command signal and a control end command signal. And a boom attitude detection sensor that detects the attitude of the boom and transmits the detected value, and operates when the control start command signal is input from the command signal transmitter and outputs the control end command signal. A controller is provided to stop, and this controller responds to the detection value input from the boom attitude detection sensor when the control start command signal is input. The work radius correction command signal for correcting the work radius to achieve vertical ground cutting is configured to be transmitted to the first hydraulic system. A bias value having a magnitude necessary for operation is added in advance.

Therefore, the operator can arbitrarily select the intervention of the controller during the ground cutting operation of the crane by operating the command signal transmitter and inputting the control command signal or the control end signal to the controller during the ground cutting operation. You can That is, when the controller is not used, the operator can lift the suspended load by the conventional manual operation operation, and when the controller is interposed, entrust the controller with the lifting operation only while the controller is interposed. Therefore, manual and automatic switching can be arbitrarily performed according to the situation of the suspended load, and a more appropriate ground cutting operation that does not cause load shake can be realized.

Then, when the control command signal is input to the controller to operate it, the controller performs a predetermined calculation from the detected value relating to the boom posture which is input from the boom posture detection sensor one by one, and determines the working radius of the boom. Modify so that vertical ground cutting is realized (specifically, modify so as to elevate or retract the boom so as to eliminate the increase in boom working radius that has increased as a result of bending under the load of the suspended load) ) Since the working radius correction command signal is transmitted to the first hydraulic system, the first hydraulic system operates based on this command signal, the working radius of the boom is corrected, and the ground cutting operation without load shake is performed.

At this time, since the work radius correction command signal is preliminarily added with a bias value having a magnitude necessary for the first hydraulic system to operate at a minimum, the above signal is transmitted. Regardless, the non-operation of the first hydraulic mechanism due to the small value of the signal is avoided, and the responsiveness of the control is improved so that the first hydraulic mechanism always operates even if the value of the signal is smaller than the following. From the result, it is convenient because the swinging of the load at the time of ground cutting is surely suppressed.

The wire raising speed for transmitting to the second hydraulic system a wire control signal for realizing the set wire raising speed by subtracting the raising speed of the boom tip portion at the time of ground cutting from the controller of the control device. If the control means is provided, the winding speed of the wire is appropriately controlled, and the shake of the load at the time of ground cutting is more reliably suppressed.

That is, when the control start command signal is input to the controller to operate it, the wire raising speed control means of the controller performs a predetermined calculation from the detected value relating to the boom posture which is input from the boom posture detection sensor one by one. Then, the ascending speed of the boom tip is calculated, and this ascending speed is subtracted from the preset ascending speed of the wire by an operator's input operation, etc. It is sent to the second hydraulic system.

Accordingly, the second hydraulic system receiving this takes up the wire at the take-up speed instructed by the wire control signal and hoists the suspended load. It is possible to prevent a sudden increase in the load, and effectively suppress the swing of the suspended load.

If the boom attitude detection sensor is composed of a load sensor for detecting the load of a suspended load applied to the boom, a boom length sensor for detecting the boom length, and a boom angle sensor for detecting the boom angle, It is possible to properly obtain the working radius correction command signal and the ascending speed correction command signal by performing a predetermined calculation based on each of the detection values detected by the boom attitude detection sensor.

Further, the load of the suspended load can be calculated by using a predetermined relational expression from the change of the boom length and the boom angle for each minute time. Therefore, as the boom posture detection sensor, the boom length is determined. Boom length sensor to detect,
It is also possible to use only a boom angle sensor that detects the angle of the boom. By doing so, the load sensor is omitted, and the equipment cost can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a schematic side view illustrating a crane to which a control device of the present invention is applied.

FIG. 2 is an explanatory diagram illustrating a flexed state of a boom.

FIG. 3 is a block diagram showing an example of a control system of the control device according to the present invention.

FIG. 4 is a graph for explaining a dead zone range in which the boom does not respond, and (a) shows a relationship between an input current value introduced to the hydraulic mechanism and a boom rotation (expansion / contraction) speed,
(B) shows the relationship between the load and the dead zone range when the boom rotation (expansion / contraction) speed is zero.

FIG. 5 is a graph for explaining that the dead zone in which the boom does not respond is eliminated, (a) shows the relationship between the input current and the output current, and (b) shows the relationship between the load and the output current. Is shown.

FIG. 6 is an explanatory diagram illustrating a state in which the control device of the present invention is applied to a tower crane or a jib crane.

[Explanation of symbols]

 1 Basic Vehicle 2 Upper Revolving Body 21 Vertical Axis 3 Boom 3a Boom Tip 30a First Boom 30b Second Boom 30c Third Boom 31 Horizontal Axis 32 Hydraulic Cylinder 4 Winding Wire 41 Pulley 42 Hook C Controller 5 Command Signal Transmitter 51 Control start lever 52 Control end lever 53 Wire lever 6 Attitude detection sensor 61 Load sensor 62 Fastening state determination means 63 Boom angle sensor 7 Controller 71 Input device 72 Working radius correction control means 73 Wire lifting speed control means 74 Signal processing means 8 Hydraulic pressure Mechanism 81 First hydraulic system 82 Second hydraulic system 9 Crane mechanical system

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Goto 740 Yagi, Okubo-cho, Akashi-shi, Hyogo Prefecture Kobe Steel Works Okubo Construction Machinery Factory (72) Inventor Akira Ishio 740 Yagi, Okubo-cho, Akashi-shi, Hyogo Co., Ltd.Kobe Steel Works Okubo Construction Machinery Factory (72) Inventor, Seizuna Kuchiki 740 Yagi, Okubo Town, Akashi City, Hyogo Prefecture Kobe Steel Co., Ltd. Okubo Construction Machinery Factory

Claims (5)

[Claims] 1. A boom, which is constructed so that it can be raised and lowered and expanded and contracted by an operation of a hydraulic mechanism, and a wire which is hanged up and down by the above operation from the tip portion of the boom, are provided with a suspended load at the tip of the wire. A vertical ground-cutting control device for a crane configured to hang and wind a wire so that a suspended load can be lifted, wherein the control device includes undulation or extension / contraction of the boom, and a rising speed of the wire. A controller for controlling is provided, and this controller corrects the change amount of the working radius due to the bending of the boom at the time of ground cutting, and in synchronization with this correction, a command signal for correcting the rising speed of the wire to the set rising speed A vertical ground cutting control device for a crane, which is configured to transmit to a hydraulic mechanism. 2. A suspended load is hung from the tip of a wire vertically hung from the distal end of a boom that is configured to freely undulate and expand and contract by the operation of a first hydraulic system, and the suspended load is wound up by winding the wire. A vertical ground cutting control device for a crane configured to be lifted, and a command signal transmitter that transmits a control start command signal and a control end command signal, and detects the boom posture and transmits this detection value. A boom attitude detection sensor is provided, and a controller is provided which operates when a control start command signal is input from the command signal transmitter and stops when a control end command signal is transmitted. When a signal is input, to correct the boom working radius according to the detection value input from the boom attitude detection sensor so that vertical ground cutting is realized. Working radius correction control means for transmitting the working radius correction command signal to the first hydraulic system is provided,
A vertical ground-cutting control device for a crane, wherein a bias value having a magnitude required for the first hydraulic system to operate at a minimum is added in advance to the working radius correction command signal. 3. A tip of a wire vertically hung from an end of a boom which is configured to be undulated and retractable by an operation of a first hydraulic system and which is vertically movable by an operation of a second hydraulic system. A vertical ground cutting control device for a crane configured to hang a suspended load and wind the above wire to send a control start command signal and a control end command signal by an operator's operation. A command signal transmitter that operates and a boom posture detection sensor that detects the posture of the boom and transmits this detection value are provided.When the control start command signal is input from the command signal transmitter, it operates and the control end command signal is sent. A controller is provided that stops when transmitted, and when the control start command signal is input to this controller, it is input from the boom attitude detection sensor. Work radius correction control means for transmitting a work radius correction command signal to the first hydraulic system for correcting the boom work radius according to the detected value so that vertical ground cutting can be realized, and the boom during ground cutting In the crane, wire raising speed control means for transmitting a wire control signal for realizing the set wire rising speed by subtracting the rising speed of the tip portion to the second hydraulic system is provided. Vertical ground cutting control device. 4. The boom posture detection sensor comprises a load sensor for detecting a load of a suspended load applied to the boom, a boom length sensor for detecting a boom length, and a boom angle sensor for detecting a boom angle. The vertical ground cutting control device for a crane according to claim 2 or 3, characterized in that. 5. The boom posture detection sensor comprises a boom length sensor for detecting the length of the boom and a boom angle sensor for detecting the angle of the boom. Vertical ground control device for cranes.