JPH04358696A - Controller for crane - Google Patents

Abstract

PURPOSE:To reduce the cycle time of a crane operation by providing a control circuit for controlling a winding and lowering speed command signal applied to a winding and lowering control system from a winding and lowering speed command system to an opening and closing system when an opening speed reducing point of a bucket is detected. CONSTITUTION:While the start of the opening operation of a bucket shifts to a lowering operation, when an opening command is sent, a control circuit 6 outputs an opening command signal to perform the opening operation of the bucket. When an opening speed reducing point is detected, a speed reduction command switch S3 is switched to apply a speed reduction command signal to a opening and closing control system 4 and this signal is transmitted to an adder 44. In a logical circuit 61, a winding and lowering speed command signal is transmitted to a winding and lowering speed controller 24 and the adder 44. The adder 44 adds the outputs of a linear commander 43 for opening and closing speed and a liner commander 23 for winding and lowering speed an generates a speed command to an opening and closing speed controller 45. When the bucket is completely opened, the logical circuit 61 outputs an opening stop command signal to control a support motor 21 and an opening and closing motor 41 at an equal speed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a crane such as a bucket crane or an unloader.

0002

[Prior Art] For example, in a two-motor type unloader, a bucket grabs ore, etc. in a storage area, transports it to a hopper located at a predetermined position higher than the storage area, discharges it, and then returns to the ore storage area. In this case, it is common to move the bucket from the hopper, move it from the closed state to the open direction, and then lower the bucket after it is completely opened. FIG. 3 schematically shows the drive system of this type of unloader, in which a bucket 33 is raised and lowered by a rope wound around a support drum 32 driven by a support motor 31, and an opening/closing drum 35 driven by an opening/closing motor 34. The bucket 33 is opened and closed using a rope wound around the bucket 33. The state in which the bucket 33 is completely opened is called the opening limit, and the opening degree A shown in FIG. 3 is the opening limit. In reality, the opening/closing speed is decelerated at an opening deceleration point before reaching the opening limit, and this opening deceleration point is indicated by the opening degree B in FIG. The opening degree C indicates the closing limit, which is a position where the bucket 33 is almost completely closed.

By the way, in conventional control devices, the bucket 33 is moved up and down by operating the support motor 31 and the opening/closing motor 34 at a constant speed.
The opening/closing operation is performed by independently operating the opening/closing motor 34, and the vertical operation of the bucket 33 and the opening/closing operation are not performed in parallel. In other words, regarding the lowering operation of the bucket 33 after completion of discharging to the hopper, the lowering operation is normally started after the bucket 33 reaches its open limit.

0004

[Problem to be solved by the invention] This problem is solved by the bucket 33
The lowering operation of the bucket 33 is performed by the constant speed operation of the support drum 32 and the opening/closing drum 35, and the opening operation of the bucket 33 is performed by the independent operation of the opening/closing drum 35. This is because the opening/closing motor 34 does not have enough power to perform the lowering operation. If this is ignored and the lowering operation is performed while the bucket 33 is being opened, the lowering operation of the bucket 33 will be performed according to the lowering speed of the support motor 31, but the speed of the opening/closing motor 34 will not be able to follow it. The opening speed of the bucket 33 decreases, making it impossible for the driver to lower and open the bucket 33 as desired. However, it is common for objects in the bucket to be discharged before or after the bucket is half-opened, and waiting to start the lowering operation until the bucket is fully opened is a waste of working time. In view of these problems, an object of the present invention is to shorten the cycle time of crane work by making it possible to perform the vertical operation of the bucket and the opening/closing operation in parallel.

[0005]

[Means for Solving the Problems] The present invention provides a hoisting/up/down control system for raising and lowering a bucket with a rope wound around a support drum driven by a support motor, and a rope wound around an opening/closing drum driven by an opening/closing motor. In a crane control device comprising an opening/closing control system that opens and closes the bucket, and an opening detection system that detects the opening of the bucket, the opening detection system controls the opening/closing speed of the bucket when the bucket is opened. When a point is detected, the opening/closing control system is controlled by a control circuit configured to supply a hoisting/up/down speed command signal given from a hoisting/up/down speed command system to the hoisting/up/down control system to the opening/closing control system. , from the opening deceleration point of the bucket until it is fully opened, the opening/closing motor is operated at a constant speed by the sum of the deceleration command signal given to the opening/closing control system from the deceleration command system and the acceleration range of the hoisting/up/down speed command signal; After full opening, the support motor is operated at a constant speed together with the opening/closing motor based on the constant speed range of the hoisting/up/down speed command signal.

The opening detection system includes an opening detector for the bucket, an opening deceleration point detector for detecting the opening deceleration point of the bucket based on the output of the opening detector, and an opening deceleration point detector for detecting the opening deceleration point of the bucket based on the output of the opening detector. a full-open detector for detecting full open of the bucket based on the output of the detector, and the control circuit is provided between the hoisting/up/down speed command system and the hoisting/up/down control system to a winding/up/down operation switch for turning on and off a speed command signal; an opening/closing operation switch provided between the opening/closing speed command system and the opening/closing control system for turning on/off the opening/closing speed command signal; a deceleration command switch provided between the opening/closing speed command system and the opening/closing operation switch for switching between the opening/closing speed command signal and the deceleration command signal; It includes a circuit that controls opening and closing of the hoisting/up/down operation switch, the opening/closing operation switch, and the deceleration command switch based on the outputs of the open deceleration point detector and the full open detector.

[0007] Further, the control circuit is configured to turn on the opening/closing operation switch in response to the opening command, and when the opening deceleration point is detected by the opening deceleration point detector after the opening operation of the bucket is started, the opening/closing operation switch is turned on. At the same time, by turning on the hoisting/up/down operation switch in response to the hoisting/up/down command, the opening/closing control system controls the opening/closing motor based on the sum of the deceleration command signal and the acceleration area of the hoisting/up/down speed command signal. Constant speed operation is maintained, and when the bucket is detected to be fully open, the opening/closing operation switch is turned off, and the opening/closing control system controls the opening/closing motor based on the constant speed region of the hoisting/up/down speed command signal. By maintaining the high speed operation, the opening operation of the bucket from the opening deceleration point to full opening is divided into a constant speed operation of the opening/closing motor and an accelerated operation before reaching the constant speed of the support motor. The feature is that this is done based on the speed difference between the

[0008]

[Operation] In the present invention, when the driver operates to start lowering immediately after the bucket is opened, the lowering command (winding up/down command) is issued after issuing the opening command and before the opening is completed. If the bucket reaches the opening deceleration point, the speed of the opening/closing motor remains the same and the supporting motor starts lowering and accelerates, thereby increasing the relative speed between the opening speed and the lowering speed. The bucket is opened in such a way that a difference is generated, and this speed difference is gradually reduced by accelerating the lowering speed, thereby decelerating the opening speed and reducing the difference to 0 at the fully open position. I will make it happen.

[0009]

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 and 2. This device includes a hoisting/up/down speed command system 1 for sending a command signal for hoisting/up/down speed of the bucket, and a hoisting/up/down control system 2 for raising and lowering the bucket using a rope wound around a support drum 22 driven by a support motor 21. , an opening/closing speed command system 3 for sending a bucket opening/closing speed command signal, a deceleration command system 3' for sending a deceleration command signal, and a rope wound around an opening/closing drum 42 driven by an opening/closing motor 41. an opening/closing control system 4 for opening and closing the bucket, a bucket opening detector 51, an opening deceleration point detector 52 for detecting the opening deceleration point based on the output of the opening detector 51, and a fully open state of the bucket. The opening detection system 5 includes a full open detector 53 for detecting the opening, the supply of a hoisting/up/down speed command signal to the hoisting/up/down control system 2, and the supply of an opening/closing speed command signal and a deceleration command signal to the opening/closing control system 4. It has a control circuit 6 for

The hoisting/up/down speed command system 1 includes a hoisting/up/down speed command 11 which sends a bucket hoisting/up/down speed command based on the operator's operation, and a hoisting/up/down speed control system 2 which transmits the hoisting/up/down speed command.
and a hoisting/vertical speed command converter 12 for converting the hoisting/vertical speed command signal into a hoisting/vertical speed command signal suitable for. The hoisting/up/down control system 2 includes a hoisting/up/down speed linear command device 23 and a hoisting/up/down speed controller 24 .

The opening/closing speed control system 3 includes an opening/closing speed command device 31 that sends out a bucket opening/closing speed command based on the operator's operation, and converts the opening/closing speed command into an opening/closing speed command signal suitable for the opening/closing control system 4. and an opening/closing speed command converter 32. The opening/closing control system 4 includes a linear command unit 43 for opening/closing speed.
, an adder 44 for adding the output from the opening/closing speed linear command unit 43 and the output from the hoisting/up/down speed linear command unit 23, and an opening/closing speed controller 45.

The control circuit 6 includes a hoisting/up/down operation switch S1 provided between the hoisting/up/down speed command system 1 and the hoisting/up/down control system 2 for turning on/off a hoisting/up/down speed command signal to the hoisting/up/down control system 2. , an opening/closing operation switch S2 provided between the opening/closing speed command system 3 and the opening/closing control system 4 for turning on/off the opening/closing speed command signal for the opening/closing control system 4; A deceleration command switch S3 is provided between the system 3 and the deceleration command switch S3, which switches between an opening/closing speed command signal and a deceleration command signal. It consists of a logic circuit 61 that turns the switch on and off.

Next, the operation of this device will be explained.
Here, in order to make the explanation easier to understand, control from the time when the bucket starts to open to release the object until it moves to the lowering operation will be explained. In the case of such work, the operator issues an opening command using the opening/closing speed command device 31 to start lowering the bucket immediately after opening the bucket.
When the opening operation is started, a hoisting/lowering command is issued using the hoisting/vertical speed command device 11. By the above operations, the device automatically performs the following operations. When the opening/closing speed command device 31 issues an opening command as shown in FIG. 2(a), in the control circuit 6, the logic circuit 61 outputs an opening command signal through the AND gate 62, thereby turning on the opening/closing operation switch S2. As a result, the opening/closing speed command from the opening/closing speed command 31 is given to the opening/closing speed controller 45 through the opening/closing speed command converter 32, the deceleration command switch S3, the opening/closing operation switch S2, the opening/closing speed linear command 43, and the adder 44. and opening/closing speed controller 45
The opening/closing motor 41 is operated (see FIG. 2c) to rewind the rope by the opening/closing drum 42 to open the bucket.

As the opening operation progresses and the bucket reaches the opening deceleration point at time T1, the support drum 22 and opening/closing drum 42
The output of the bucket opening detector 51 which detects the bucket opening from the rotation with the opening deceleration point detector 52 becomes the set opening of the opening deceleration point detector 52.
The open deceleration point detector 52 outputs an open deceleration point detection signal. The deceleration command switch S3 is switched to give a deceleration command signal to the opening/closing control system 4 in response to the opening/closing point detection signal, and this deceleration command signal passes through the opening/closing operation switch S2 and the opening/closing speed linear command 43 to the adder 44. is transmitted to.

On the other hand, in the logic circuit 61, the hoisting/up/down operation switch S1 is activated by outputting a hoisting/up/down operation command signal through an AND gate 63 and an OR gate 64 based on the hoisting command (winding/up/down command) and the opening deceleration point detection signal. Turns on. As a result, a hoisting/up/down speed command signal as shown in FIG. 2(b) is transmitted to the hoisting/up/down speed controller 24 and adder 44 via the hoisting/up/down speed linear command unit 23. The opening/closing speed command signal and the winding/up/down speed command signal have an acceleration region and a deceleration region indicated by diagonal lines in FIG. 2, and a constant speed operation region therebetween. The adder 44 adds the output of the opening/closing speed linear command unit 43 and the output of the hoisting/up/down speed linear command unit 23 to generate a speed command to the opening/closing speed controller 45 .

[0016] By making the rising timing of the signal from the hoisting/vertical speed linear command unit 23 the same as the timing of the start of deceleration by the opening/closing speed linear command unit 43, the deceleration region of the opening/closing speed command signal and The sum of the hoisting and vertical speed command signals and the acceleration range can be made constant, and the opening/closing motor 41 can be driven at a constant speed. On the other hand, the support motor 21 started at time T1 gradually accelerates;
There is a difference between the speed of the opening and closing motor 41, and the opening operation speed is reduced by this difference. The above speed difference becomes smaller as the lowering speed accelerates, and at time T2, the speed difference between the support motor 21 and the opening/closing motor 41 becomes 0, and the bucket is fully opened. When the bucket is fully opened, the detection level of the bucket opening detector 51 is set to the fully open detector 5.
3, and the logic circuit 61 outputs an open stop command signal through the NOT circuit 65 and the AND gate 62 based on the output from the fully open detector 53. This open/stop command signal turns off the open/close operation switch S2, and both the support motor 21 and the open/close motor 41 are driven by the linear command unit 2 for hoisting and vertical speed.
The speed is controlled at a constant speed based on the output of No. 3.

The AND gate 63 is turned on when a winding/lowering command is input during opening deceleration, and the AND gate 67 is turned on when a winding/lowering command is input while the opening command is off. It is.

In FIG. 2, the broken line portion indicates the operation timing in the case of a conventional control device. It takes time t1 to stop lowering. In contrast, in the present invention, by making the opening/decelerating operation parallel to the lowering operation, the opening/closing motor 41 can be opened and decelerated by the speed difference between it and the supporting motor 21 without decelerating it. Can be done. By doing this, the time from the start of the opening operation to the stop of lowering becomes t2,
The time t can be shortened compared to the conventional time t1.

[0019]

[Effects of the Invention] As explained above, according to the present invention, the cycle time of crane work can be shortened by making it possible to perform bucket opening/closing operation and lowering operation in parallel. can.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a crane control device according to the present invention.

[Fig. 2] Bucket opening/closing operation by the control device of the present invention;
FIG. 4 is a time chart diagram for explaining the winding and up-down operations.

FIG. 3 is a diagram for explaining the opening and closing operation of a bucket in a general crane.

[Explanation of symbols]

1 Volume vertical speed command system 2　　　Volume up/down control system 3 Opening/closing speed command system 4 Opening/closing control system 5 Opening detection system 21 Support motor 41 Opening/closing motor 61 Logic circuit S1 Volume up/down operation switch S2 Open/close operation switch S3 Deceleration command switch

Claims (3)

[Claims] 1. A hoisting/up/down control system in which the bucket is raised and lowered by a rope wound around a support drum driven by a support motor, and an opening/closing system in which the bucket is opened and closed by a rope wound around an opening/closing drum driven by an opening/closing motor. In a crane control device that includes a control system and an opening detection system that detects the opening of the bucket, when the opening detection system detects the opening deceleration point of the bucket during the opening operation of the bucket, the opening deceleration point of the bucket is detected. The opening/closing control system is configured to control the opening/closing control system by controlling the hoisting/up/down speed command signal given from the up/down speed command system to the hoisting/up/down control system to the opening/closing control system. From to fully open, the opening/closing motor is operated at a constant speed by the sum of the deceleration command signal given to the opening/closing control system from the deceleration command system and the acceleration range of the hoisting vertical speed command signal, and after fully opening, the hoisting vertical speed command is A crane control device, characterized in that the support motor is operated at a constant speed together with the opening/closing motor based on a constant speed region of a signal. 2. The crane control device according to claim 1, wherein the opening detection system detects an opening deceleration point of the bucket based on an opening detector of the bucket and an output of the opening detector. the control circuit includes an open deceleration point detector for detecting the full opening of the bucket based on the output of the opening degree detector, and a full open detector for detecting the full opening of the bucket based on the output of the opening degree detector; a hoisting/up/down operation switch provided between the hoisting system and the hoisting/up/down speed command signal for turning on and off the hoisting/up/down speed command signal; and a hoisting/up/down operation switch provided between the opening/closing speed command system and the opening/closing control system for turning on/off the hoisting/closing speed command signal. an opening/closing operation switch for turning on and off; a deceleration command switch provided between the opening/closing speed command system and the opening/closing operation switch for switching between the opening/closing speed command signal and the deceleration command signal; a circuit that controls opening/closing of the hoisting/up/down operation switch, the opening/closing operation switch, and the deceleration command switch based on the bucket hoisting/up/down command and opening command and the outputs of the open deceleration point detector and the fully open detector; A crane control device comprising: 3. The crane control device according to claim 2, wherein the control circuit turns on the opening/closing operation switch in response to the opening command, and controls the opening/closing operation switch to control the opening/closing operation by the opening deceleration point detector after the opening operation of the bucket starts. When the point is detected, the deceleration command switch is switched, and the hoisting/up/down operation switch is turned on in response to the hoisting/up/down command, thereby causing the opening/closing control system to adjust the acceleration range in the deceleration command signal and the hoisting/up/down speed command signal. The opening/closing motor is maintained at a constant speed based on the sum of By maintaining constant speed operation of the opening/closing motor based on the speed range, the opening operation of the bucket from the opening deceleration point to full opening is controlled.
A control device for a crane, characterized in that the operation is performed based on a speed difference between a constant speed operation of the opening/closing motor and an accelerated operation before reaching the constant speed of the supporting motor.