JP2000272882A - Control device for jib crane turning speed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stop accelerating and decelerating at optional timing, and also change acceleration and deceleration in the turning speed of a jib crane. SOLUTION: A table, having stipulated accelerating or deccelerating quantities in accordance with the number of notches from a notch 13, is equipped to control a turning speed with the table referred when the notch frequency is given by a control device 12. At that time, imparting the predetermined notch frequency stops accelerating and deccelerating the turning speed by the device 12.

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 controlling a swing speed of a jib crane.

[0002]

2. Description of the Related Art In general, various control methods are known for controlling the turning speed of a jib crane.
As a turning speed control device, a control device that combines a hydraulic resistance foot brake with secondary resistance control (hereinafter referred to as a first control device), a control device that uses thyristor Leonard control (hereinafter referred to as a second control device), and an inverter A control device using control (hereinafter, referred to as a third control device) is known.

[0003] In the first control device, when the jib crane turns, acceleration is controlled by a notch and deceleration control is performed by a hydraulic foot brake. In the second and third control devices, speed control, that is, acceleration control and deceleration control, is performed by the notch.

Conventionally, in the second and third control devices, the turning speed of the jib crane is controlled by a notch operation of a controller, and a ratio (%) of the full speed is defined according to the number of notches. For example, one notch is set to 10% of the full speed, two notches to 30% of the full speed, three notches to 60% of the full speed, and four notches to 100% of the full speed.

[0005]

In the case of the first control device, the acceleration is controlled by the notch of the controller, and the deceleration is controlled by the hydraulic foot brake. However, there is a problem that it is difficult to perform a low-speed operation in the tailwind, and that the maintenance of the brake must be performed frequently.

On the other hand, in the second and third control devices, the speed is controlled by the notch of the controller.
The change in the turning speed is extremely small even when the load changes due to wind or other causes. However, in the second and third control devices, since the speed is determined by the notch of the controller as described above, the speed becomes constant even though it is desired to continue the acceleration in order to prevent the suspension of the suspended load. On the contrary, there is a problem that the acceleration is continued up to the notch speed even though it is desired to stop the acceleration. Further, there is a problem that acceleration and deceleration cannot be changed.

An object of the present invention is to provide a turning speed control device capable of stopping acceleration and deceleration of a jib crane at an arbitrary timing using a thyristor leonard control or an inverter control.

Another object of the present invention is to provide a turning speed control device capable of changing acceleration and deceleration by using thyristor Leonard control or inverter control.

[0009]

According to the present invention, there is provided a control device for controlling a turning speed of a jib crane,
A table in which the amount of acceleration or the amount of deceleration is defined according to the number of notches from the notch, and control means for controlling the turning speed with reference to the table when the number of notches is given. A characteristic jib crane turning speed control device is obtained. The control means stops accelerating or decelerating the turning speed when a predetermined number of notches is given.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

As shown in FIG. 1, the jib crane includes a jib crane main body 11.
The turning direction and the turning speed are controlled by the turning speed control device 12. In the illustrated example, the turning speed control device 1
Numeral 2 controls the turning direction and the turning speed by thyristor Leonard control or inverter control. Although the turning speed control device 12 is shown outside the jib crane main body 11, the turning speed control device 12 including the notch 13 is arranged in the operation room of the jib crane.

Referring to FIG. 2 as well, the treatment shown in FIG. 2 is set in the turning speed control device 12, and the turning speed control device 12 performs the treatment according to the operating condition given from the notch 13. The turning speed is controlled based on the turning speed.

As shown in FIG. 2, the operating conditions prescribe the number of notches and the operating direction of the controller notch (for example, right and left of the operating direction are forward and reverse (F · R) of the inverter, respectively). ), A speed command and acceleration / deceleration are defined in the treatment. For example, notch 13
When the driving direction (turning direction) is left when the right direction is 4 notches, the turning speed control device 12 performs the deceleration at an acceleration of setting the speed command to 0% of the full speed and performing 100 to 0% deceleration in 8 seconds. . In addition, when the notch 13 is four notches on the right and the driving direction is right, the turning speed control device 12 accelerates at an acceleration of performing 0 to 100% acceleration in 8 seconds with the speed command as 100% of the full speed. . Hereinafter, as shown in FIG.
The treatment by the turning speed control device 12 is performed according to the operation amount and the driving direction of (the description is omitted because it is as shown in FIG. 2).

Here, the actual operation control (turn control) will be described with reference to FIG.

When the operation is started at four notches and the four notches are maintained, the speed reaches 100% of the full speed in eight seconds. If it is desired to maintain that speed during acceleration, returning to two notches will maintain that speed. After that, if you make 3 notches, it will be accelerated slowly. And 10 seconds of full speed in 20 seconds
Reaches 0%. If three notches are provided from the beginning, the acceleration is slow.

When decelerating to one notch, the speed is reduced slowly, and it takes 20 seconds to stop when driving at 100% of the full speed. If two notches are set during deceleration, the current speed is maintained. After that, when the notch is set to 0 notch, the speed is rapidly reduced. In addition, if there is 0 notch from the beginning, the speed is reduced rapidly and stops in 8 seconds.

In the example shown in the figure, an example of dividing up to four notches is shown. However, if the number of notches is increased, a large number of accelerations / decelerations can be selected, so that acceleration / deceleration control can be performed more finely. it can.

[0018]

As described above, according to the present invention, the acceleration time or the deceleration time at which the jib crane reaches the full speed or the stop is defined according to the number of notches and the direction of the notches, that is, the jib crane is adjusted according to the number of notches. Since the speed can be selected, the acceleration and deceleration of the turning speed of the jib crane can be stopped at an arbitrary timing, and the acceleration and deceleration can be changed.

[Brief description of the drawings]

FIG. 1 schematically shows an example of a jib crane provided with a control device according to the present invention.

FIG. 2 is a diagram showing an example of a table provided in the control device shown in FIG.

FIG. 3 is a diagram for explaining turning speed control of the jib crane shown in FIG. 1;

[Explanation of symbols]

 11 Jib crane body 12 Swing speed control device 13 Notch

Claims (2)

[Claims] 1. A control device for controlling a turning speed of a jib crane, comprising a table in which an amount of acceleration or an amount of deceleration is defined according to the number of notches from a notch, wherein the number of notches is given. Control means for controlling the turning speed with reference to the table. 2. The jib crane turning speed control device according to claim 1, wherein said control means stops acceleration or deceleration of said turning speed when a predetermined number of notches is given. Jib crane turning speed control device.