JPH0335232B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a ground cutting control device for a crane with a jib, and more specifically, the present invention relates to a ground cutting control device for a crane with a jib, and more specifically, a jib that schedules the lifting operation of a suspended load according to the swing angle of a wire. This relates to cranes with attached cranes. This is used, for example, in the field of preventing swinging of a suspended load during ground cutting in a jib-equipped crane mounted on a ship.

[Conventional technology]

In a crane with a jib, the hoisting wire is often not perpendicular to the load before it is lifted, and when the load is taken off the ground, the load may swing. This is because the jib bends due to the load of the hoisted load, or in the case of a crane mounted on a ship, the wire hanging from the jib may bend to the vertical line of the hoisted load due to the rocking of the ship due to waves etc. This is based on generating a certain deflection angle with respect to the

In such cases, conventionally, the crane operator has relied on his/her intuition to correct the jib's elevation angle and, if necessary, the turning angle before cutting off the ground. Adjusting the winding speed of the wire. However, it was not possible to completely eliminate load swing, and incorrect operation could lead to trouble.

[Problem to be solved by the invention]

A device that prevents the swinging of a suspended load when cutting the ground without relying on the operator's operations is
There is a steady rest control device for a crane with a jib described in Japanese Patent Publication No. 59-26599. This system prevents load swing caused by the deflection of the jib or the post located at the base of the jib due to the hoisted load.The load and jib radius are detected as soon as the hoisted load begins to be hoisted, and the corresponding deflection is detected from the moment. It is now possible to calculate quantities. Then, the amount of movement of the upper end of the wire is determined from the amount of deflection, and the jib is operated accordingly to control the suspended load so that it is always on the vertical line from the tip of the jib.
A suspended load can be lifted while preventing the load from swinging when the suspended load is cut off the ground.

According to such a control device, it is possible to prevent load swing when there is an uneven load caused by bending of the jib, etc., but when the crane is mounted on a ship, it is possible to prevent the load from swinging. Load swing cannot be prevented if the hoisting wire is not vertical. Moreover, the above-mentioned device requires a device to detect the load of the suspended load and the radius of the jib, as well as a calculation device for the moment and amount of deflection, resulting in the problem that the load swing prevention device itself is large-scale and expensive. .

The present invention was made in view of the above problems, and
The purpose of this is not only when a jib or post is bent due to a hoisted load, but also when a ship carrying a crane is rocking due to waves, or when there are restrictions on where the hoisted load can be placed. To provide a ground cutting control device for a crane with a jib that can avoid load swing during ground cutting even in cases where it is not possible to provide a crane with a jib.

[Means to solve the problem]

The present invention controls the operation of the jib based on the speed commanded by the jib operation speed setting device, and also controls the operation of the jib based on the speed commanded by the hoisting speed setting device.
Applies to cranes with a jib that control the hoisting speed of the wire suspended from the jib.

Its characteristics are as shown in Figure 1.
A hoisting slow speed setting device 15 instructs to hoist the wire at a very slow speed at the time of breaking the ground, and a time from the lifting start command until the suspended load comes off the ground is set in advance, and the time varies within and outside of the set breaking time. When the ground cutting time setting device 16 outputs a signal, the wire deflection angle detector 17 detects the deflection angle of the wire from a predetermined reference position, and the deflection angle is detected from the wire deflection angle detector. Comparator 1 that outputs different signals by distinguishing between
8, and upon receiving the signal from the comparator and the ground-cutting time setting device 16, if there is a wire deflection angle within the setting time of the ground-cutting time setting device 16, the operating circuit of the jib operation speed setting device 7 If there is no wire deflection angle within the time set by the ground-off time setting device 16, switch to the operating circuit of the hoisting slow speed setting device 15 to adjust the wire deflection angle to zero. When the hoist is hoisted at a slow speed and the time set by the ground cutting time setting device 16 is exceeded, the operating circuits of the hoisting speed setting device 8 and the jib operation speed setting device 7 are switched to perform normal operation.

〔Example〕

The present invention will be described in detail below based on examples thereof.

Figure 2 shows a jib-equipped crane 1 to which the present invention is applied.
In this schematic diagram, a jib 4 that can be elevated and rotated is attached to a post 3 fixed to a hull 2, and a wire 5 is suspended from the tip of the jib 4 so that a suspended load 6 can be moved. FIG. 1 is an overall system diagram of the ground cutting control device, which controls the elevation and turning direction of the jib 4 based on the speed commanded by the jib operation speed setting device 7, and also controls the operation of the jib 4 in the elevation and turning direction based on the speed commanded by the hoisting speed setting device 8. Based on the speed determined, the wire 5 hanging from the jib
The winding speed can be controlled.

In this example, the jib 4 is used as the jib operating speed setting device 7.
Elevation speed setting device 7A and turning speed setting device 7B
Two setting devices are provided. The former is jib 4
The latter defines the winding or unwinding speed of a winch wire (not shown) for raising and lowering the shaft, and the latter defines the rotational speed of, for example, a hydraulic motor that rotates the jib 4 about the post 3. In addition, each setting device can specify the desired speed by, for example, the amount of rotation of the handle.
The signal is outputted to the elevation winch control means 9 and the swing motor control means 10, and the respective drive devices 1
1 and 12.

The above-mentioned hoisting speed setting device 8 can specify the hoisting speed after the suspended load 6 has cut off the ground, and this is output to the hoisting winch control means 13, and the hoisting speed for hoisting or unwinding the wire 5 for lifting the suspended load 6 is outputted to the hoisting winch control means 13. The drive 14 of the upper winch can be controlled.

In such a ground cutting control device, a hoisting slow speed setting device 15 outputs a signal for hoisting the wire 5 at a slow speed to the hoisting winch control means 13 at the time of ground cutting.
is provided. This is to ensure work safety by gradually winding up the wire 5 until the suspended load 6 comes to rest, thereby preventing sudden tension in the wire and swinging of the suspended load. Therefore, the hoisting speed setting device 8 quickly moves the suspended load 6 to a predetermined position after cutting off the ground.
The speed is set to be much slower than the speed specified in .

In addition to such a setting device, there is also a ground breaking time setting device 16 which is configured in advance to set the time from the lifting start command until the suspended load 6 cuts off the ground, and outputs different signals inside and outside the set ground breaking time. is provided. This is because the time required to reach the ground is roughly determined, so by setting that time, for example, a 0 signal as shown in Figure 3 is sent out within that time, and a 1 signal is sent outside of that time. It is designed to output a signal. As a result, the winding wire 5
If there is a swing angle, the elevation angle and turning angle of the crane 1 can be corrected in advance, and unscheduled operations are regulated, and on the other hand, after the time has elapsed, operations such as hoisting the wire 5 are possible. It has the function of

By the way, the jib 4 and the like are provided with a wire deflection angle detector 17 that detects the deflection angle of the wire 5 from a predetermined reference position, and detects how much the wire 5 deflects with respect to the vertical line of the suspended load 6. can now be detected. Since this detector itself is well known, a description thereof will be omitted, but the wire deflection angle detector 17A in the elevation direction detects the deflection angle in the elevation direction of the jib 4, and the wire deflection angle detector 17A in the swing direction detects the deflection angle in the direction of the swing angle. An angle detector 17B is installed, and comparators 18A and 18B each output a different signal by distinguishing whether the deflection angle of the wire is too large to be ignored or not.
is attached. The output signal of the comparator 18 is 0 and 1, and if it is necessary to correct the elevation angle or turning angle of the jib 4 before cutting, the signal is 0, for example, and if the correction is not necessary or necessary before cutting, the signal is 0. It outputs a signal of 1 when it runs out.

In response to signals from such a comparator 18 and the above-mentioned ground-off time setting device 16, the operating circuits of the hoisting fine speed setting device 15, the hoisting speed setting device 8, the elevation speed setting device 7A, and the swinging speed setting device 7B are activated. Each gate is provided which can be switched. That is, as shown in the figure, logic circuits such as a NOT gate 20, a NOR gate 21, and AND gates 22 and 23 are provided, and analog switches 24 to 29 which are opened and closed according to their respective outputs are arranged. Note that the circuit is not limited to this type of circuit.
For example, a similar function can be achieved by having contacts that are opened and closed by a relay or by using a microcomputer.

According to the ground cutting control device configured as described above, it is possible to prevent the load from swinging when the suspended load is cut from the ground in the following manner.

When a hoisting signal is applied to the hoisting speed setter 8, the timer of the ground-off time setter 16 counts a predetermined ground-off time _T0 , and a signal of 0 is output within that time. If the wire 5 is vertical and the wire deflection angle detector 17A in the elevation direction and the wire deflection angle detector 17B in the swing direction detect respective deflection angles of zero or negligible deflection angles that do not cause load deflection, , a signal of 0 is output from the comparators 18A and 18B.

As a result, all the inputs to the NOR gate 21 shown by the two-dot chain line in FIG. 4 become 0, the output from this gate becomes 1, and the analog switch 25 is turned on. As a result, a command from the hoisting slow speed setting device 15 is input to the hoisting winch control means 13, and the hoisting winch drive device 14 is driven. Then, the wire 5 is wound up at a safe slow speed until it cuts off. In addition, at this time, other analog switch 2
4, 26 to 29 are all turned off, and no elevation or turning is performed (see Fig. 4).

Now, due to the pitching and rolling of the ship, the wire 5 is moving in the elevation and turning direction as shown by the two-dot chain line in Figure 2.
deviates from the vertical direction, the elevation direction wire deflection angle detector 17A and the turning direction wire deflection angle detector 17B detect the deflection angle. If the angle is large enough to affect load swing, a signal proportional to it is output, and the comparators 18A and 18B
A signal of 1 is output from. Within ground cutting time T ₀
Since the output of NOT gate 20 is 1,
The inputs to the AND gates 22 and 23 shown by solid lines in FIG. 5 are all 1, and their outputs are also 1, turning on the analog switches 27 and 29.

Accordingly, the wire deflection angle detector 1 in the vertical and vertical directions
The command from 7A is input to the elevation winch control means 9, the command from the swing direction wire swing angle detector 17B is input to the swing motor control means 10, and the elevation winch drive device 11 and the swing motor drive device 12 are respectively driven. Ru. As a result, the deflection angle in the elevation and rotation direction is corrected at a speed proportional to the deflection angle of the wire 5. Incidentally, it is also possible to perform corrections by elevation or turning simply by turning on and off without being proportional to the deflection angle, but it is convenient to make corrections in proportion to the swing angle because correction operations can be performed without a shock.

At this time, since the output of the comparator 18 is 1 and the output of the ground cut time setting device 16 is 0, the output of the NOR gate 21 is 0, the analog switch 25 is turned off, and the hoisting winch drive device 14 is turned off. never operates. In such an operation, for example, if there is no deflection angle in the turning direction,
Needless to say, since the correction is not necessary, it is carried out only in the elevation direction (see Fig. 5).

When the correction is performed as described above, 1 is output from the NOR gate 21 as described above, and the hoisting winch hoists at a slow speed. When the ground cutting is completed and a predetermined ground cutting time _T0 has elapsed (see Fig. 4), 1 is output from the ground cutting time setting device 16, and the analog switches 25, 27,
29 is turned off, while analog switches 24,
26 and 28 are turned on, and the circuit between the hoisting speed setting device 8 and the hoisting winch control means 13, the circuit between the elevation speed setting device 7A and the elevation winch control means 9, and the circuit between the swing speed setting device 7B and the swing motor control means 10. The circuit is connected. Therefore, when each normal operation is performed, the hoisting winch drive device 14, the elevation winch drive device 11, and the swing motor drive device 1
A hydraulic or electric drive device such as 2 is driven, and the hanging load 6 can be moved to a desired position.

Note that the wire deflection angle detector in the elevation direction and the wire deflection angle detector in the turning direction detect the deflection angle when the wire is not in the vertical direction, so if the suspended load is not placed properly or if the ship is shaken. It is possible to correct not only cases where there is movement, but also cases where the deflection angle is caused by deflection of the jib or post.

〔Effect of the invention〕

As can be seen from the description of the embodiments above, the present invention has the following features:
The time from the lifting start command until the hoisted load comes off the ground is set, and the deflection angle is detected by the ground breaking time setter that outputs different signals within and outside the set ground breaking time, and the wire deflection angle detector. Since it is equipped with a comparator that outputs different signals to distinguish between when it is activated and when it is not, it receives signals from both and sets the hoisting fine speed setting device, hoisting speed setting device, or jib operation speed setting device. The operating circuit can be switched. Therefore, the lifting operation of the load can be scheduled according to the deflection angle of the wire, and even with an extremely simple device, automatic and safe cargo handling can be performed without requiring operator skill.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of the ground cutting control device of the present invention,
FIG. 2 is a schematic diagram of a crane with a jib to which the present invention is applied, FIG. 3 is an example of a signal output from a ground cutting time setting device, and FIGS. 4 to 6 are explanatory diagrams of control states. 1... Crane with jib, 4... Jib, 5... Wire, 7, 7A, 7B... Jib operation speed setting device (elevation speed setting device, swinging speed setting device), 8... Hoisting speed setting device, 15... Hoisting slow speed setting device, 16...
Ground cutting time setting device, 17, 17A, 17B...Wire deflection angle detector (elevation direction wire deflection angle detector,
Turning direction wire deflection angle detector), 18, 18A,
18B...Comparator.

Claims (1)

[Claims] 1. The operation of the jib is controlled based on the speed commanded by the jib operation speed setting device, and the hoisting speed of the wire suspended from the jib is controlled based on the speed commanded by the hoisting speed setting device. A crane with a jib that is designed to be controlled includes a hoisting slow speed setting device that commands to hoist the wire at a slow speed when cutting off the ground, and a preset time from the hoisting start command until the hoisted load cuts off the ground. Also, a ground breaking time setting device that outputs different signals within and outside the set ground breaking time, a wire deflection angle detector that detects the deflection angle of the wire from a predetermined reference position, and the wire deflection angle. a comparator that outputs different signals to distinguish between when the deflection angle is detected by the detector and when it is not; and a ground-cutting time setting device that receives signals from the comparator and the ground-cutting time setting device. If there is a wire deflection angle within the set time, switch to the operating circuit of the jib operation speed setting device and correct the wire deflection angle to zero, and reduce the wire deflection angle within the set time of the ground cutting time setting device. If not, switch to the operating circuit of the hoisting speed setting device to hoist the suspended load at very slow speed, and when the set time of the ground breaking time setting device is exceeded, the operating circuit of the hoisting speed setting device and jib operation speed setting device A ground cutting control device for a crane with a jib, which is characterized by being able to perform normal operation by switching to the ground.