JPS61211296A - Critical controller for crane with jib - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] C. Industrial Application Field] The present invention relates to an appropriate control device for a crane with a jib, and more specifically, a crane with a jib that schedules the lifting operation of a suspended load according to the swing angle of a wire. Regarding. 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.

[Prior art]

In a crane with a jib, the hoisting wire is often not perpendicular to the load before it is lifted, and the load may swing when the load is taken off the ground. 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, conventional methods have relied on the intuition of the crane operator to correct the jib's elevation angle and, if necessary, the swing angle before cutting off the ground, and to adjust the jib operating speed and wire The winding speed is adjusted.

However, it was not possible to completely eliminate load swing, and incorrect operation could lead to serious accidents.

To avoid relying on such operations by workers (and to prevent swinging of the suspended load when cutting the ground),
There is a steady rest control device for a crane with a jib described in Japanese Patent No. 6599. 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 possible to calculate quantities. Then, the amount of movement of the upper end of the wire is calculated 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. It is possible to lift a suspended load without preventing the load from swinging when cutting 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 to calculate the moment and amount of deflection, which poses the problem of making the load swing prevention device itself costly and expensive. .

[Purpose of the invention]

The present invention was made in view of the above-mentioned problems, and its purpose is not only when a jib or post is bent due to a suspended load, but also when a ship carrying a crane itself is rocked by waves, and To provide an appropriate control device for a crane with a jib that can avoid load swing during ground cutting even in cases where wires cannot be arranged vertically due to restrictions on the placement location of a suspended load.

[Structure of the invention]

The features of the appropriate control device for a crane with a jib according to the present invention will be explained with reference to FIG.
5, a time setting device 16 that specifies the time from the lifting start command until the suspended load reaches the ground, and outputs different signals inside and outside the specified ground-off time, and a predetermined reference position of the wire. The wire deflection angle detector 17 detects the deflection angle from the wire deflection angle detector 17, and the comparator 18 outputs a different signal to distinguish when the deflection angle is detected from the wire deflection angle detector and when it is not detected. The operating circuits of the hoisting fine speed setting device 15, the hoisting speed setting device 8, or the jib operation speed setting device 7 can be switched in response to signals from the comparator and the other time setting device 16.

〔Example〕

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

FIG. 2 is a schematic diagram of a jib-equipped crane 1 to which the present invention is applied, in which a jib 4 that can be elevated and rotated is attached to a post 3 fixed to a ship's hull 2, and a wire 5 is suspended from the tip of the jib 4 for lifting a load. 6 can be moved. FIG. 1 is an overall system diagram of the appropriate 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 winding speed of the wire 5 hanging from the jib can be controlled.

In this example, two setting devices are provided as the jib operation speed setting device 7: an elevation speed setting device 7A of the jib 4 and a turning speed setting device 7B. The former defines the winding or unwinding speed of a winch wire (not shown) for raising and lowering the jib 4, and the latter regulates the winding or unwinding speed of the winch wire (not shown) for raising and lowering the jib 4.
For example, it defines the rotational speed of a hydraulic motor that rotates the motor. Note that each setting device can specify a desired speed by, for example, the amount of rotation of the handle, and the signal is sent to the elevation winch control means 9 and the swing motor control means 10.
It is possible to output the signals to the respective drive devices 11 and 12 to drive the respective drive devices 11 and 12. The hoisting speed setting device 8 mentioned above can specify the hoisting speed after the suspended load 6 has cut off the ground.
This is output to the hoisting winch control means 13, and can control the hoisting winch drive device 14 that winds up or lets out the wire 5 for lifting the suspended load 6.

In such a multi-parameter control device, a signal for hoisting the wire 5 at a slow speed during ground cutting is sent to the hoisting winch control means 1.
3 is provided. This is to ensure work safety by gradually winding up the wire 5 until the suspended load 6 reaches the ground, 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, the lifting load 6 can be adjusted from the lifting start command.
Other time setting device 1 that specifies the time until the ground-off and outputs different signals inside and outside the specified ground-off time.
6 is provided. This is because the time required to cut the ground is approximately fixed, so by specifying that time, for example, the O signal shown in Figure 3 is sent during that time, and the 1 signal is sent outside of that time. It is designed to output a signal. As a result, if the hoisting wire 5 has a deflection angle before cutting the ground,
It has a function of allowing the elevation angle and turning angle of the crane 1 to be corrected in advance, as well as regulating unspecified operations, while enabling operations such as hoisting the wire 5 after the time has elapsed.

By the way, the jib 4 and the like are equipped with a wire deflection angle detector 17 that detects the deflection angle of the wire 5 from a predetermined reference position.
is provided so that it is possible to detect how much the wire 5 swings with respect to the vertical line of the suspended load 6. 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 angle direction of the jib 4, and the wire deflection angle in the swing direction detects the deflection angle in the swing angle direction. An angle detector 17B is installed,
Comparators 18A and 18B are attached to each of them to output different signals to distinguish whether the deflection angle of the wire is too large to be ignored or not. The output signals of the comparator 18 are O and 1. For example, when it is necessary to correct the elevation angle or turning angle of the jib 4 before cutting, O is used, and when the correction is not necessary or necessary before cutting, O is used. It outputs a signal of 1 when it becomes .

In response to signals from such a comparator 18 and the above-mentioned other 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, NOT gate 2
0. Logic circuits such as a NOR gate 21 and AND gates 22 and 23 are provided, and analog switches 24 to 29 that are opened and closed according to their respective outputs are arranged.

Note that the circuit is not limited to such a circuit, and the same function can be achieved by, for example, having contacts that are opened and closed by a relay, or by employing a microcomputer.

According to the other control device having the above-described configuration, it is possible to prevent the load from swinging when the suspended load is cut off the ground in the following manner.

When a hoisting signal is applied to the hoisting speed setter 8, the timer of the other time setting device 16 sets the predetermined time T.
o is counted, and an O signal 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 O, 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 switches 24, 26 to 29
are all turned off and no elevation or turning is performed.
See Figure 4].

If the wire 5 deviates from the vertical direction in the elevation and turning directions due to pitching or rolling of the ship, as shown by the two-dot chain line in FIG. Angle detector 17B detects the deflection angle. If the angle is large enough to affect load swing,
A signal proportional to that is output, and the comparator 18A,
A signal of 1 is output from 18B. Since the output of the NOT gate 20 is 1 during the appropriate time To, all inputs to the AND gates 22 and 23 shown by the solid line in FIG.
1, and its output also becomes 1, and the analog switch 27
．． 29 is turned on. As a result, the command from the wire deflection angle detector 17A in the elevation and elevation directions is transmitted to the elevation winch control means 9.
A command from the swing direction wire deflection angle detector 17B is input to the swing motor control means 10, and the commands are input to the swing motor control means 10, and the elevation winch drive device 11 and the swing motor drive device 12, respectively.
is driven. 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 if the correction is made proportional to the swing angle, it is convenient because the correction operation can be performed without causing 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 O, the analog switch 25 is turned off, and the hoisting winch drive device 14 In such an operation, for example, if there is no deflection angle in the turning direction, there is no need for correction, so it goes without saying that correction is performed only in the elevation direction (see Fig. 5).

When the correction is made as described above, 1 is output from the NOR gate 21 as described above, and the hoisting winch is hoisted at a slow speed. After the ground cutting is completed, a predetermined time T elapses.
When o has elapsed (see Fig. 4), 1 is output from the ground-off time setter 16, and as shown in Fig. 6, the analog switches 25, 27, and 29 are turned off, while the analog switches 24, 26, and 28 are turned off. is turned on, the circuit between the hoisting speed setting device 8 and the hoisting winch control means 13, and the elevation speed setting device 7A
and the circuit between the elevation winch control means 9 and the swing speed setting device 7
A circuit between B and the swing motor control means 10 is connected. Therefore, when each normal operation is performed, hydraulic or electric drive devices such as the hoisting winch drive device 14, the elevation winch drive device 11, and the swing motor drive device 12 are driven to move the suspended load 6 to the desired position. can do.

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 detailed description of the embodiments above, the present invention is a ground-off time setting device that specifies the time from the lifting start command until the suspended load breaks off the ground, and outputs different signals inside and outside the specified ground-off time. and a comparator that outputs different signals to distinguish between when the deflection angle is detected by the wire deflection angle detector and when it is not, so that the hoisting fine speed setting device, The operating circuit of the hoisting speed setter or jib operation speed setter can be switched. Therefore, the cargo lifting operation can be scheduled according to the deflection angle of the wire, and the cargo handling operation can be carried out automatically and safely using an extremely simple device and without requiring operator skill.

[Brief explanation of the drawing]

Figure 1 is an overall system diagram of the other control device of the present invention, Figure 2 is a schematic diagram of a crane with a jib to which the present invention is applied, Figure 3 is an example of a signal output from a ground cutting time setting device, 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, turning speed setting device), 8 - Hoisting speed setting device, 15 - Hoisting fine speed setting device, 16 - Other time setting device, 17.17A, 17
B-Wire deflection angle detector (elevation direction wire deflection angle detector, turning direction wire deflection angle detector), 18.18A, 18
B - Comparator. Patent applicant: Kawasaki Heavy Industries, Ltd. Agent: Patent attorney: Katsutoshi Yoshimura (and one other person) Figure N2 Figure 3

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 equipped with A ground cut time setting device that outputs different signals inside and outside the cut time, a wire deflection angle detector that detects the deflection angle of the wire from a predetermined reference position, and a deflection angle detected by the wire deflection angle detector. and a comparator that outputs different signals to distinguish when the ground-cutting time setting device is activated and when it is not, and the hoisting fine speed setting device and the hoisting speed setting device Or, a ground cutting control device for a crane with a jib, characterized in that the operating circuit of the jib operating speed setting device can be switched.