JPH07330285A - Turning control device for slewing crane - Google Patents

Abstract

PURPOSE:To prevent oscillation of a suspended load remaining in a constant speed turning drive condition in the case of driving a slewing crane having initial oscillation of the load for constant speed turning drive. CONSTITUTION:A turning control device is composed of a speed command signal outputting means 9 to output a command signal (b) to command a turning speed of a turntable, a turning speed detection means 10 to detect an actual turning speed of the turntable, a load oscillation condition detection means 12, a work radius detection means 13, and a valve control signal output part 8 to receive signals from these means, and control a turning control valve 6 of a turning motor 5. The valve control signal output part 8 is provided with an acceleration pattern operation part 8b, an acceleration start signal output part 8c to calculate an acceleration start timing at which no oscillation remains at the suspended load, and a valve control signal operation part 8a to output a valve control signal (a) to start acceleration, and the turning control valve 6 is controlled by the valve control signal (a) outputted from the valve control signal operation part 8a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing control device for a swing type crane, in which a boom is mounted on a swivel so that it can be lifted and lowered, and a load is suspended from the tip of the boom. , In particular, the swing in the swing direction of the suspended load when the swivel is stopped (hereinafter referred to as the initial swing of the suspended load) is automatically suppressed during acceleration drive of the swivel to eliminate the swing of the suspended load at the end of acceleration. The present invention relates to a turning control device for a turning crane.

[0002]

2. Description of the Related Art FIG. 9 includes a swing base 2 which is swingably mounted on a base 1 and is driven to swing by a swing hydraulic motor 5, and a boom 3 which is mounted on the swing base 2 so as to be capable of being raised and lowered. 1 illustrates a swing crane in which a suspended load 4 is hoisted from a tip end portion of a boom 3 and hoisted to be freely driven. Such a swivel crane is used for swiveling the swivel 2, driving the boom 3 up and down, and hoisting and hoisting the suspended load 4 to perform crane work. If the suspended load 4 swings in the turning direction, safe crane work cannot be performed. Therefore, it is necessary to prevent the suspended load 4 from swinging in the turning direction while the swivel base 2 is being driven to rotate at a constant speed.

Conventionally, when the swivel 2 is accelerated to an arbitrary constant swivel driving speed when there is no initial swing of the suspended load 4 when the swivel 2 is stopped, the acceleration time of the acceleration is the swing cycle of the suspended load. By making the acceleration of this acceleration constant, the swing of the suspended load 4 in the turning direction with respect to the tip of the boom 3 when the swivel base 2 reaches an arbitrary constant-speed turning drive speed is eliminated. A turning control device is known. This type of turning control device will be described with reference to FIGS. 10 and 11.

In FIG. 10, the swing hydraulic motor 5 that drives the swing base 2 to swing is controlled by a swing control valve 6 that controls the supply and discharge of hydraulic oil to and from the swing hydraulic motor 5. There is. The swing control valve 6 is switch-controlled by a valve drive means 7 which is drive-controlled by a valve drive signal a from a valve control signal output section 8 described later.

[0005] 9, a speed command signal output means for outputting a command signal b corresponding to the constant speed rotation drive speed theta _V of the swivel deck 2, constant-speed rotation driving speed theta _V is to be able to arbitrarily set the operator It has become.

Reference numeral 10 is a turning speed detecting means for detecting an actual turning speed of the turntable 2 and outputting an actual turning speed signal Θ _V '.

Reference numeral 11 denotes a load swing cycle time calculating means for detecting a load swing cycle time t of the suspended load 4, which is a suspension distance detector 11a for detecting a suspension distance h of the suspended load 4, and a suspension distance detector 11a. It is configured by a calculation unit 11b that calculates the load swing cycle time t of the suspended load 4 from the hanging distance h signal from the distance detector 11a.

The valve control signal output section 8 receives signals from the speed command signal output means 9, the turning speed detection means 10 and the load shake cycle time calculation means 11, and the valve drive means 7 is operated.
And outputs a valve drive signal a to the valve control signal calculator 8a and an acceleration pattern calculator 8b.

The acceleration pattern calculation unit 8b of the valve control signal output unit 8 receives the command signal b from the speed command signal output unit 9 and the load swing cycle time t from the load swing cycle time detection unit 11, and is related to the receipt. In accelerating the swivel base 2 to the constant speed swing drive speed Θ _V corresponding to the command signal b,
An acceleration pattern is obtained in which the acceleration time is an integral multiple of the swinging cycle time t of the suspended load 4 and the acceleration is constant, and the acceleration control signal c necessary for accelerating and driving the swivel base 2 with this acceleration pattern is output. . FIG. 11 shows this acceleration pattern.
Here, the acceleration time is set to be one time the load swing cycle time t of the suspended load 4. The acceleration control signal c is started when the command signal b is received from the speed command signal output means 9.

The valve control signal calculation unit 8a includes a command signal b from the speed command signal output means 9 and an acceleration pattern calculation unit 8a.
It receives the acceleration control signal c from b and the actual turning speed signal Θ _V 'from the turning speed detecting means 10, and outputs the valve drive signal a by calculation. When the command signal b is input, the valve control signal calculation unit 8a first accelerates the swivel base 2 to a speed corresponding to the command signal b with an acceleration pattern corresponding to the acceleration control signal c from the acceleration pattern calculation unit 8b. The valve drive signal a necessary for driving is output. After that, the valve drive signal a necessary for driving the swivel base 2 at a constant speed at a speed corresponding to the command signal b is output. The actual turning speed signal Θ _V 'from the turning speed detecting means 10.
Is used as a feedback signal for accuracy of speed control.

In the conventional swing control device for a swing crane constructed as above, when the command signal b is input from the speed command signal generating means 9 to the valve control signal output section 8 while the swivel base 2 is in the swing stop state, The swivel base 2 is accelerated up to the constant speed swing drive at the constant speed swing drive speed Θ _V corresponding to the command signal b, and the acceleration at that time is the acceleration time of the swinging cycle time t of the suspended load 4. It is designed to be automatically controlled so that it is an integral multiple (1 in the above embodiment) and the acceleration is constant.

If the conventional technique is used in which the acceleration time is an integral multiple of the swinging cycle time t of the suspended load 4 and the swing control is performed at a constant acceleration, the principle that the swinging of the cargo is suppressed after the end of acceleration is Ω /
Description will be made using a phase plane in which ω and θ are selected as Cartesian coordinates.
FIG. 3 shows the suspended load 4 supported by the rope when the tip fulcrum 0 of the boom 3 moves at a speed v. Where L ₀ is the rope length, m ₀ is the mass of the suspended load 4, V is the speed of the boom tip in the turning direction, θ is the swing angle of the suspended load 4, Ω is the swing angular velocity of the suspended load 4, and g is the gravitational acceleration. To do. Further, when the shake natural angular frequency of the suspended load 4 is ω, the following formula is obtained.

[0013]

[Equation 1]

When the turning speed is V _M and the turning radius is R,
There is a relationship of V = V _M R, and assuming that the directions of θ and V in FIG. 3 are positive, the equation of motion of the suspended load 4 linearized under the assumption that the deflection angle θ is sufficiently small is as follows. Like

[0015]

[Equation 2] Here, a _M is the turning acceleration.

When the general solution of (Equation 2) is obtained, (Ω / ω) ² + (θ + a _M R / g) ² = C --------- (1)

Here, C is an arbitrary constant, and C can be obtained by giving the state of the suspended load 4 as an initial condition. If the initial condition is that there is no initial swing of the suspended load, then C = (a _M R
/ G) ^{2 and} assuming that a _M is constant, as shown in FIG.
Radius a _M R / g centered on the center (0, −a _M R / g)
The time for drawing a circle and making one round from the origin corresponds to the load swing cycle time t (t = 2π / ω). That is, when acceleration corresponding to t such that a _M is constant is performed, a locus of returning to the origin again after one round from the origin is drawn, and a state without load shake can be obtained.

That is, in the conventional swing control device, when accelerating the swivel base 2 in the stopped state to an arbitrary constant speed swing drive speed Θ _V , the acceleration time of the acceleration is an integral multiple of the swing cycle time t of the suspended load. And by keeping this acceleration constant,
It is possible to eliminate the swinging of the suspended load 4 in the turning direction with respect to the tip of the boom 3 when the swivel base 2 reaches an arbitrary constant turning drive speed Θ _V. However, in the conventional swing control device, if the suspended load 4 swings in the swing direction when the swivel base 2 is stopped, that is, if the suspended load 4 has an initial swing, the boom 3 tip end when the constant-speed swing drive is started. It is impossible to eliminate the swing of the suspended load 4 in the turning direction.

[0019]

The swing control device for the swing crane according to the present invention has a tip of the boom 3 at the end of the acceleration drive (when the constant speed swing drive is started) when the suspended load 4 has an initial swing. An object of the present invention is to provide a turning control device capable of eliminating load swing in the turning direction of the suspended load 4 with respect to a portion.

[0020]

The outline of the swing control device in the swing crane of the present invention is as follows: information relating to the initial swing, a predetermined constant swivel drive speed Θ _{V of} the swivel, and a working radius R (swivel 2 The acceleration pattern as a function of the horizontal distance from the turning center to the suspended load 4) is determined, and when the acceleration in the determined acceleration pattern is completed, the acceleration start timing at which the swinging of the suspended load 4 in the swing direction disappears. the initial shake information was calculated based on related to, at acceleration start timing thus calculated, the acceleration pattern so as to start the acceleration drive of the swivel deck 2 by the turning base 2 is constant-speed turning drive speed theta _V Te than The load shake of the suspended load 4 (the shake of the load in the turning direction with respect to the tip of the boom 3) when the load is reached is to be eliminated.

Therefore, the swing control device in the swing crane according to the present invention is constructed as follows. A swing control device used for a swing crane in which a boom 3 is attached to a swing base 2 that is swing-driven by a swing hydraulic motor 5 so that the boom 3 can be freely moved up and down, and a suspended load 4 is suspended from the tip of the boom 3. A valve drive means 7 for switching the swing control valve 6 that controls the supply and discharge of hydraulic oil to the swing hydraulic motor 5, and a command signal b corresponding to the constant swing drive speed Θ _V of the swivel base 2 are output. A speed command signal output means 9, a swing speed detection means 10 for detecting an actual swing speed Θ _V 'of the swivel base 2, and a load shake state detection means 12 for detecting an actual load shake state of the suspended load 4. The standard deflection position θ with the suspended load 4 as the reference
_The load shake state detection means 1 for detecting the time T _{p at p} , the load shake cycle time t of the suspended load 4, and the maximum shake angle θmax.
2, working radius detection means 1 for detecting the turning radius R of the suspended load 4
3, the speed command signal output means 9 and the detection means 1
The signals from 0, 12, and 13 Θ _V , Θ _V ', T _p , t, θ
a valve control signal output section 8 for receiving max, R and outputting a valve drive signal a to the valve drive means 7. The valve control signal output section 8 includes an acceleration pattern calculation section 8b and an acceleration start signal output section. 8c and a valve control signal calculation unit 8a. The acceleration pattern calculation unit 8b includes a command signal b from the speed command signal output unit 9, a load shake cycle time t from the load shake state detection unit 12, and a maximum value. The deflection angle θmax and the work radius R signal from the work radius detection means 13 are received, and an acceleration pattern obtained as a function of these signals is calculated. The acceleration start signal output unit 8c causes the swivel base 2 to generate the acceleration pattern. Computing unit 8b
When the acceleration is completed with the acceleration pattern calculated by, the acceleration start load swing position is calculated so that the load swing in the turning direction does not remain on the suspended load 4 when the acceleration is completed, and the acceleration start load swing related to this calculation is calculated. From the position and the time T _{p at} which the suspended load 4 from the load shake state detection means 12 reaches the reference shake position θ _p , the actual load shake position is accelerated so that it coincides with the acceleration start load shake position for calculation. The valve control signal calculator 8a outputs a start signal, and the valve control signal calculator 8a receives the acceleration start signal from the acceleration start signal output unit 8c, and at the same time, the actual turning speed Θ _V ′ detected by the turning speed detector 10 is , A valve control signal a necessary for accelerating the swivel base 2 so as to follow the acceleration pattern calculated by the acceleration pattern calculation unit 8b is calculated and calculated, and the valve control signal a is output as the output of the valve control signal output unit 8 to drive the valve. Go to means 7 Turning control apparatus in the swivel crane, characterized in that it is configured to.

[0022]

When the command signal b from the speed command signal output means 9 is input to the valve control signal output section 8, the swing control apparatus for the swing crane according to the present invention configured as described above is operated. The acceleration pattern calculation unit 8b of the above-mentioned acceleration signal calculation unit 8b, the constant speed swing drive speed Θ _{V of} the swivel base 2, the load swing period time t and the maximum swing angle θmax from the load swing state detection unit 12, and the working radius detection unit. The acceleration pattern is calculated based on the signal of the work radius R from 13.

On the other hand, when the swivel base 4 is accelerated according to the acceleration pattern calculated by the acceleration pattern calculation unit 8b, the acceleration start signal output unit 8c outputs the suspended load 4 when the acceleration is completed.
In addition to calculating the acceleration start load shake position where no load shake in the turning direction remains, the acceleration start load shake position related to this calculation and the reference shake position based on the suspended load 4 from the load shake state detection means 12 are calculated. from the time T _p, which came to theta _p, outputs an acceleration start signal so that the actual load pendulum position coincides with the acceleration start load pendulum position according to the calculation.

Then, the valve control signal calculation unit 8a receives the acceleration start signal from the acceleration start signal output unit 8c, and at the same time, the actual turning speed Θ _V 'detected by the turning speed detecting means 10 is calculated as the calculated acceleration. The valve control signal a required for accelerating and driving the swivel so as to follow the pattern is calculated and calculated, and is output to the valve driving means 7 as the output of the valve control signal output section 8.

Therefore, in the swing control device for the swing crane according to the present invention, the acceleration according to the acceleration pattern is completed, and the swing speed of the swivel base 2 corresponds to the command signal b from the speed command signal output means 9. _In the state of _V , the swing of the suspended load 4 (the swing of the swinging direction with respect to the tip of the boom 3) can be eliminated.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a turning control device for a turning crane according to the present invention will be described below with reference to FIGS.

The turning control device in the turning crane of the present invention is different from the conventional turning control device in the following points. The load shake cycle time detection means 11 in the conventional swing control device is changed to the load shake state detection means 12 that detects information regarding the initial shake. In the valve control signal output unit 8 in the conventional turning control device,
An acceleration start signal output unit 8c is added. The working radius detection means 13 is added to the conventional turning control device, and this signal is input to the valve control signal output section 8. Acceleration pattern calculation unit 8b in the valve control signal output unit 8
Change the calculation of the acceleration pattern in. Since other configurations are similar to those of the conventional turning control device, the description thereof will be omitted in the following description.

In FIG. 1, reference numeral 12 is a load shake state detecting means. The load shake state detecting means 12 detects the time T _p when the suspended load 4 having the initial shake reaches the reference load shake position θ _p, which is a reference.
The load shake cycle time t of the initial shake and the maximum shake angle θmax of the initial shake are detected. 2 shows the boom 3
It is a figure which shows the relationship between the front-end | tip part 3a of FIG.
FIG. 6 is a diagram shown under a relationship in which the tip portion 3a of the boom 3 moves in parallel with the paper surface when the vehicle turns. In FIG. 2, the reference load shake position θ _p (one shake end position in this example) and the maximum shake angle θ max are displayed.

In FIG. 1, the load shake state detecting means 12 is shown.
Is a swing angle detector 12a attached to the tip of the boom 3 for detecting the swing angle θ of the hanging load 4 in the turning direction, and a computing unit 12b for receiving and computing a signal from the swing angle detector 12a. I am configuring. The calculation unit 12b detects the time T _p when the suspended load 4 reaches the reference load swing position θ _p (one swing end position in this example) from the swing angle signal that periodically changes from the swing angle detector 12a. The load shake cycle time t of the load 4 is detected (detected as one cycle time of output fluctuation of the shake angle detector 12a), and the maximum shake angle θmax of the suspended load 4 is detected.
It is designed to detect

Numeral 13 is a working radius detecting means for detecting a horizontal distance between the turning center of the swivel base 2 and the suspended load 4, that is, a working radius R. The working radius detecting means 13 is a boom length detector 13 a that detects the length of the boom 3, an elevation angle detector 13 b that detects the elevation angle of the boom 3, and these detectors 13.
The calculation unit 13c receives signals from a and 13b and calculates a working radius R as a cosine of the boom length.

The valve drive signal output section 8 outputs a command signal b (constant speed swing drive) from the speed command signal output means 9, the swing speed detection means 10, the load shake state detection means 12, and the working radius detection means 13. Speed Θ _V ), actual turning speed Θ _V ', time T _p when the reference load swing position θ _p is reached, load swing cycle time t, maximum swing angle θ max, and working radius R, and the valve drive means 7 is valved. The drive signal a is output.

The valve control signal output unit 8 comprises an acceleration pattern calculation unit 8b, an acceleration start signal output unit 8c, and a valve control signal calculation unit 8a.

The acceleration pattern calculation unit 8b of the valve control signal output unit 8 outputs the command signal b (constant speed swing drive speed Θ _V ) from the speed command signal output unit 9 and the load swing cycle time from the load swing state detection unit 11. Each signal of t, the maximum deflection angle θmax, and the working radius R from the working radius detection means 13 is received, and an acceleration pattern obtained as a function of these signals is calculated. The acceleration pattern calculated by the acceleration pattern calculation unit 8b will be described later.

When the swivel base 4 is accelerated in the acceleration pattern calculated by the acceleration pattern calculation unit 8b, the acceleration start signal output unit 8c of the valve control signal output unit 8 applies to the suspended load 4 when the acceleration is completed. The acceleration start load shake position θ _s is calculated so that the load shake in the turning direction does not remain, and from the reference load shake position θ _p from the load shake state detection means 12 to the acceleration start load shake position θ _s related to this calculation. The time required for the load to move is calculated, and the time T _p when the load reaches the reference load swing position θ _p detected by the load swing state detection means 12 is added to this time to output the acceleration start signal T. Calculate _s . Then, when the acceleration start time T _s is reached, an acceleration start signal is output. A method for calculating the acceleration start load deflection position θ _s and the time T _{s at} which the acceleration start signal is output will be described later.

The valve control signal calculation section 8 of the valve control signal output section 8
a receives the acceleration start signal from the acceleration start signal output unit 8c and at the same time accelerates the swivel base 2 so that the actual turning speed Θ _V 'detected by the turning speed detecting means 10 follows the calculated acceleration pattern. Valve control signal a required to drive
Is calculated and output to the valve driving means 7 as the output of the valve control signal output section 8.

Next, regarding the calculation of the acceleration pattern by the acceleration pattern calculation unit 8b and the calculation of the acceleration start signal by the acceleration start signal output unit 8c, as an example, the acceleration pattern by one acceleration or the acceleration pattern by two-step acceleration is calculated. The cases will be sequentially described.

FIG. 5 shows the trajectory of the swing of the suspended load on the phase plane created so that the swing does not remain when the acceleration is completed by one acceleration operation, and FIG. 6 shows the velocity pattern in that case. T _{0 in} FIG. 6 is B from the load deflection position at point A in FIG.
It is the time required to reach the point where the acceleration starts at the point where T
₁ is the acceleration time required to prevent the load shake from remaining when the acceleration is completed.

From the equation (1), h in FIG. 5 is expressed as follows.

H = (θ _VR ) / (T ₁ g) ------------- (2)

In order to establish the acceleration pattern of FIG. 6, the following conditions are geometrically required from FIG. Where θma
x is the maximum initial deflection angle.

Θmax / 2 ≦ h ------------- (3) 0 <β ≦ π

From FIG. 5, T ₀ , T ₁ , α and β are geometrically as follows.

T ₀ = (π + 2α) / (2ω) ------------- (4)

T ₁ = (2π−β) / ω ------------- (5)

Α = sin ⁻¹ (θmax / 2h) ------------- (6)

Β = cos ⁻¹ {1-θmax ² / (2h ² )} ----- (7)

From the expressions (2), (3) and (5), the following conditional expression is established between the constant speed swing drive speed θ _V and the maximum initial swing angle θ max, and if this conditional expression is satisfied: The acceleration pattern of FIG. 6 can be applied.

(Πgθmax) / (2ωR) ≦ θ _V ------------ (8)

Since T _{1 in} FIG. 6 is an unknown number, the Newton-Raphson method is applied as the solution. First, by substituting equations (2) and (5) into (7), the following equation is obtained.

2D ² cos (ωT ₁ ) = 2D ² −θmax ² T ₁ ² ----------- (9) where D = (θ _VR ) / g

In order to obtain T ₁ from the equation (9), T ₁
The calculation of the following formula is repeated until the j-th approximation value of T ₁ ^j becomes sufficiently close to T ₁ ^{j +} ₁ to obtain T ₁ .

T ₁ ^{j + 1} = T ₁ ^j −f (T ₁ ^j ) / f ′ (T ₁ ^j ) where f (T ₁ ) = 2D ² cos (ωT ₁ ) −2D ² + θmax ² T ₁ ² ------ (10)

[0052] where f '(T ₁ ^j) is T ₁ of the f (T ₁ ^j)
It is the differential value with respect to ^j .

Since the Newton-Raphson method requires the initial value of T ₁ , the convergent initial values calculated in advance by changing the working radius and the maximum initial deflection angle are stored and used as a table.

The time T _{S at} which the acceleration start signal is output is as shown in FIG.
In the example, when the deflection position (point A in FIG. 5) that is the maximum value of the initial deflection angle on the positive side in the turning direction is selected as the reference load deflection position θ _p , the suspended load reaches the reference load deflection position θ _p . Time is T _p
Then, the following is obtained by using the equation (5).

T _S = T ₀ + T _P ------------ (11)

Calculation of the acceleration pattern by the two-step acceleration will also be described. In the case of α <π / 4 in FIG. 5, by geometrically creating the trajectory of the swing of the suspended load as shown in FIG. 7, the acceleration pattern in which the load swing does not remain after the acceleration is completed, that is, as shown in FIG. It is also possible to obtain a two-step acceleration pattern. In order to obtain this two-step acceleration pattern, the following conditions must be geometrically satisfied.

[0057]

[Equation 3]

Substituting equations (2) and (7) into (Equation 3),
The following conditional expression is satisfied between the constant swing drive speed θ _V and the maximum initial deflection angle θ max, and if the conditional expression is satisfied, the two-step acceleration pattern of FIG. 8 can be applied.

[0059]

[Equation 4]

T ₀ in FIG. 8 is the time required from the load deflection position at point A in FIG. 7 to the first acceleration start load deflection position, and V
Geometrically, the following equations are obtained, where ₄ and T ₄ are the first acceleration end velocity and the first acceleration time, respectively.

Α = sin ⁻¹ {θmax / (2q)} ------------ (12)

Ν = sin ⁻¹ {1-θmax ² / (2q ² )} ------------ (13)

T ₀ = (π + 2α) / (2ω) ------------ (14)

T ₄ = ν / ω ------------ (15)

V ₄ = (qgT ₄ ) / R ------------ (16)

From the arc of FIG. 7, the second acceleration time T _{5 of} FIG. 8 and the velocity V ₅ at the end of the second acceleration are geometrically as follows.

T ₅ = π / 2ω ------------ (17)

V ₅ = (qgT ₅ ) / R + V ₄ ------------ (18)

Here, the constant swing drive speed θ _V and _V in FIG.
_{Since 5} must match, V ₅ =
_Let θ _V be the equation (13) and (15) to (17).
Substituting in 8), we get the equation for the unknown q. A velocity pattern can be obtained by obtaining q from this equation by the Newton-Raphson method.

Regarding the calculation of the first acceleration start load deflection position at point B in FIG. 7 and the time at which the first acceleration start signal is output,
This is similar to the case of the acceleration pattern by one acceleration operation described above.

The swing control device of the swing crane according to the present invention configured and operated as described above is used at the end of swing acceleration (when the constant speed swing drive is started) when the load 4 has an initial swing. It is possible to eliminate the swinging of the suspended load 4 in the turning direction with respect to the boom tip portion, which greatly contributes to the safety of crane work.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a turning control device in a turning crane according to the present invention.

FIG. 2 is an explanatory diagram of initial swing of a suspended load in a turning direction.

FIG. 3 is an explanatory diagram of a rope and a model of a suspended load for deriving a motion equation of a swing of the suspended load.

FIG. 4 is an explanatory phase plan view showing a trajectory of swing of a suspended load due to an acceleration pattern.

FIG. 5 is an explanatory diagram of a trajectory of swing of a suspended load by one acceleration operation.

FIG. 6 is an explanatory diagram of an acceleration pattern by one acceleration operation.

FIG. 7 is an explanatory diagram of a trajectory of swing of a suspended load due to a two-stage acceleration operation.

FIG. 8 is an explanatory diagram of an acceleration pattern by a two-step acceleration operation.

FIG. 9 is an explanatory diagram of a swing crane.

FIG. 10 is a block diagram for explaining a swing control device in a conventional swing crane.

FIG. 11 is an explanatory diagram of an acceleration pattern used in a conventional turning control device.

[Explanation of reference numerals] 1; base, 2; swivel base, 3; boom, 3a; tip part, 4; suspended load, 5; swing hydraulic motor, 6; swing control valve, 7; valve drive means, 8; valve Control signal output section, a: valve drive signal, 9: speed command signal output means, b: command signal, 10: turning speed detection means, 12: load shake state detection means, 12a, shake angle detector, 12b; computing section , 13: working radius detecting means, 13a: boom length detector, 13b: elevation angle detector, 13c: computing unit, t: swinging cycle time of suspended load, Θ _V ; commanded turning speed, Θ _V '; actual Swivel speed, θ _p ; reference run-out position, T _p ; time when the suspended load comes to the standard run-out position, θ max: maximum deflection angle, θ: deflection angle of suspended load, Ω; deflection angular velocity, ω; suspended load deflection natural angular frequency, L _0; rope length, m _0; hanging load, g; gravitational acceleration, V; boom tip Time, R; turning radius, V _M; turning speed, a _M; turn acceleration, theta _s; acceleration starting load pendulum position T _s; time T ₀ for outputting the acceleration start _{signal, T 1, T 4, T} 5, α , Β, ν, h, q, V ₄ ,
V ₅ ; symbol used to calculate the acceleration pattern,

Claims (1)

[Claims] 1. A revolving crane in which a boom 3 is mounted on a revolving base 2 which is revolvingly driven by a revolving hydraulic motor 5 so that the boom 3 can be lifted and lowered, and a suspended load 4 is hung from the tip of the boom 3. A swing control device to be used, which is: -Valve driving means 7 for switching a swing control valve 6 for controlling supply / discharge of hydraulic oil to / from a swing hydraulic motor 5-Corresponding to a constant speed swing drive speed Θ _V of a swivel base 2. Speed command signal output means 9 for outputting the command signal b; Swing speed detection means 10 for detecting the actual swing speed Θ _V 'of the swivel base 2; Swing state for detecting the actual swing state of the suspended load 4 The reference shake position θ that is the detection means 12 and is based on the suspended load 4.
_The load shake state detection means 1 for detecting the time T _{p at p} , the load shake cycle time t of the suspended load 4, and the maximum shake angle θmax.
2, working radius detection means 1 for detecting the turning radius R of the suspended load 4
3, the speed command signal output means 9 and the detection means 1
The signals from 0, 12, and 13 Θ _V , Θ _V ', T _p , t, θ
a valve control signal output section 8 for receiving max, R and outputting a valve drive signal a to the valve drive means 7. The valve control signal output section 8 includes an acceleration pattern calculation section 8b and an acceleration start signal output section. 8c and a valve control signal calculation unit 8a, and the acceleration pattern calculation unit 8b includes a command signal b from the speed command signal output unit 9, a product shake cycle time t from the product shake state detection unit 12, and a maximum value. It receives the signals of the deflection angle θmax and the work radius R from the work radius detection means 13, and calculates the acceleration pattern obtained as a function of these signals. When acceleration is performed according to the acceleration pattern calculated by the acceleration pattern calculation unit 8b, when the acceleration is completed, the acceleration start load swing position is calculated so that load swing in the turning direction does not remain on the suspended load 4. The acceleration start load pendulum position according to this calculation, the shake position suspended load 4 is the reference from load pendulum state detecting means 12 theta _p
From the time T _p, which came to, so that the actual load pendulum position coincides with the acceleration start load pendulum position of the calculation, and outputs an acceleration start signal, the valve control signal calculating unit 8a, the acceleration start At the same time as receiving the acceleration start signal from the signal output unit 8c, the actual turning speed Θ _V 'detected by the turning speed detecting means 10 is necessary for accelerating the swivel base 2 so as to follow the calculated acceleration pattern. A swing control device for a swing crane, characterized in that the valve control signal a is calculated and calculated, and is output to the valve driving means 7 as an output of a valve control signal output section 8.