JPH0780670B2 - Overhead crane with shake prevention operation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention automatically suppresses swinging of a suspended load due to acceleration or deceleration without impairing normal operation when driving with operator control of an operator. The present invention relates to an overhead crane equipped with a deterrent device.

[Conventional technology]

Generally, when operating an overhead crane, it is extremely difficult to drive the crane without causing swinging of the suspended load, which requires skill. In particular, swaying due to acceleration and deceleration at the time of starting and stopping is inevitable, and as one of automatic means for suppressing this, there is, for example, Japanese Patent Publication No. 61-31029. The outline is shown in FIG. The figure shows the traveling speed-time relationship diagram of the overhead crane. When the vehicle accelerates at a predetermined acceleration a and then travels at a uniform speed, and nears the end point, the first stage uniform deceleration speed β1.
The speed is decelerated by, the operation is performed at a constant speed for a while, and then the vehicle is decelerated and stopped at the constant deceleration speed of the second stage.

[Problems to be Solved by the Invention]

However, there is a problem that the above two-step deceleration requires time and effort for operation. Further, the shake prevention at the time of start-up is due to the driver's operation, and when the shake occurs, it is difficult to stop it and there is a problem in terms of driver safety as well as a drop or collision of the suspended load.

In view of the above point, the present invention has an object to automatically suppress a shake due to acceleration and deceleration without impairing its function when a driver performs a normal operation.

[Means for Solving the Problems]

(B) For the driver to perform shake suppression operation by acceleration / deceleration according to the shake cycle (nT) of the suspended load. ) An arithmetic unit that synchronizes the acceleration / deceleration time with this swing cycle in order to regulate the constant speed operation speed according to the swing cycle (nT) of the suspended load. The driver's inching operation for short-range shake restraining operation is stored. Provide a computing device that repeatedly operates at the timing calculated from the swing cycle (nT) of the suspended load. Then, in addition to the normal operation of the operating device, each of the above devices is selected and performed.

[Action]

Acceleration / deceleration speed and uniform operation speed are automatically determined by the swing cycle of the suspended load. Therefore, no shake occurs during operation.

Further, in short-distance driving, the inching operation of the driver is stored, and the inching is automatically repeated at the timing calculated from the swing cycle of the suspended load.

〔Example〕

1 to 8 show an embodiment of the present invention. FIG. 1 shows a shake restraining operation device for the overhead crane 1.
The overhead crane 1 includes a hanging wire W hanging wire 4 and a winding drum 6 that winds the wire 4 on a club 3 that runs on a girder 2, and the winding drum 6 has a wire winding amount (unwinding amount). Encoder 7 for detection is installed oppositely, and load meter 5 is placed on club 3.
Equipped with. 8 is a sheave on the lifting equipment side to which a hook 9 is attached, 10
Is a club drive motor.

Further, reference numeral 12 is a crane operation device which is hung from the club 3, and is provided with a large number of push buttons and the like as described later.

The shake restraining operation device 20 for the overhead crane 1 includes a speed control device 21 for each drive motor 10, a device 22 for detecting a hoisting position or level of the load W, a load detection device 23, and a calculation device 24. The speed control device 21 is composed of, for example, an inverter, and is connected to the arithmetic device 24 via the output circuit 25.

The level detection device 22 calculates and stores the winding amount of the wire 4, that is, the hoisting position of the hoisting load W, based on the input signal from the encoder 7. The load detection device 23 detects the load of the suspended load based on the signal from the load meter 5.

The crane operation device 12 is provided with a signaling device 26 such as a buzzer indicator or a light emitting device, a function selector 27 for selecting a type of transportation operation described later, and an acceleration notch 28 for instructing acceleration / deceleration.

Each of the detection devices 22 and 23, the arithmetic device 24, and the like are incorporated in a circuit 30 such as a sequencer and a microcomputer, and a parameter setter 31 for setting necessary information is connected.

The arithmetic unit 24 calculates the shake cycle for automatically controlling the shake generated as the crane travels, and controls the operating speed. The procedure is based on FIG. 2 and FIG. explain.

In FIG. 2, the upper reference line X is a horizontal line passing through the center of the winding drum 6, the distance to the floor F is L0, and the wire 4
L11 is the distance between the horizontal center line Y passing through the center of the hoist-side sheave (hereinafter simply referred to as sheave) 8 and the upper reference line X when the hoisted load W is ground cut, and the center line Y and the floor surface. Let the distance to be L12.

L2 is a transport center line Z passing through the center of the sheave 8 during transport.
And the upper reference line X, L3 is the distance from the lower surface of the suspended load (including the weight of the sheave 8 and the hook 9) to the center of gravity G of the suspended load. L2 is set arbitrarily by the suspended load. In addition, V shows the uppermost position where the sheave 8 is lifted to the uppermost position.

In this case, when considering the suspended load as a simple pendulum, the following motion method is established.

Pendulum length L _ef = L ₂ + L ₁₂ -L ₃ L _ef · + g θ = −a where angular velocity θ is the deflection angle of the rope from the vertical angle a is the angular velocity and the period T of the deflection is The present invention synchronizes the acceleration at the time of starting and the deceleration with respect to the target stop position with the swing period (T), and the procedure is shown in FIG. The figure (a) is the traveling speed-time diagram of the crane, the figure (b) is the deflection angle-time diagram of the suspended load, and the acceleration time is the same as the deflection period T. Therefore, the constant speed operation speed Va
Is determined by the swing period. However, the acceleration / deceleration time is not necessarily one cycle of the shake, and may be two cycles or more. In particular, it may be preferable to set the period to 2 when decelerating.

Note that the traveling distance from the lifting position to the target stop position may be a short distance that does not reach twice the distance to the acceleration end point. That is, the target stop position may be overrun even if the acceleration end point is immediately followed by deceleration.

In this case, an inching operation is performed, and the procedure is
Shown in the figure. In this case, the target stop position is accurately reached by accelerating and decelerating twice, including a temporary stop in the middle. Accelerating operation (t11 hours) is performed with a target of 1/4 of the required travel distance, and immediately The deceleration operation is performed, this pattern is stored and the operation is temporarily stopped. As a result, the runout returns to zero and then runs in the opposite direction (the direction of travel of the crane). The stored pattern operation is restarted in synchronism with this shake and stopped while suppressing the shake.

It should be noted that the present invention automatically informs the driver that middle-range and long-distance shifts have been completed, or that the shift of acceleration has been completed, and thereafter enables driving by normal operation. The operation is performed, and the procedure will be described with reference to FIGS. 5 to 8.

First, the hook 9 is lowered by turning on the descending push button PB1, slinging is performed, and the wire 4 is wound up and stopped when the suspended load W is ground. This is detected by, for example, the load detection device 23 and stopped. This gives the height in FIG.
Measure L12 and store distance L11. Or sheave 8
The distance L11 is automatically calculated from the effect and the rise of, and then the hoisting operation is performed to hoist it to an arbitrary suspended load height L2. In addition,
The height L3 up to the center of gravity G is input in advance, whereby the effective shake length L _ef is calculated and stored.

Then, the function selection push button 27 is selectively switched. First, the operation when switching to non-designated will be described with reference to FIGS. 5 and 6. After switching the above push button 27, push the running (horizontal) row push button PBS2 ON
To do. At the same time, the acceleration notch 28 is turned on.

The arithmetic unit 24 calculates the shake period T from the effective shake length L _ef , inputs a predetermined acceleration to the control unit 21, accelerates the crane along the acceleration line a, and reaches the predetermined constant speed operation switching point b. When the switching point b is reached, the vibration has returned to the zero point as described above, and the signal device 26 is activated to notify the driver.

The time to reach the switching point b is n times the shake period T (n
= 1 or 2), but generally n = 1 during acceleration.
Is set to.

It should be noted that the crane starts traversing or traveling when the push button PBS2 is turned on, and therefore the acceleration timing due to the turning on of the switching notch 28 causes an error of t _01.
Is set to reach the switching point b at the time (t ₀₂ ) after the start of acceleration.

The driver operates on the basis of a normal manual operation after the operation of the signaling device 26, and turns off the switch PBS2 when approaching the target stop position. Along with this, the arithmetic unit 24 issues a deceleration command and stops after nT time (n = 1 or 2).

Next, the case where the function selection button 27 is switched to normal will be described.

Also in this case, the lateral (running) push button PBS2 is turned on and the acceleration notch 28 is turned on as in the case described above. As a result, similarly to the above, the vehicle accelerates along the acceleration line (a) and reaches the constant speed operation switching point b after nT time. After that, regardless of whether the notch 28 is ON or OFF, the operation is automatically switched to the constant speed operation (c). After that, the pushbutton PBS2 is turned off in the same manner as described above to shift to the deceleration operation (d) and stop after nT time (n = 1 or 2).

In some cases, speed change may be desired during operation. For example, when accelerating along the acceleration (a) and when it is desired to switch to constant speed operation, the function selection push button 27 is turned off. However, while the acceleration notch 28 is ON, the vehicle is accelerated as it is, but when the notch 28 is turned OFF, the acceleration is stopped and the vehicle moves to the constant speed operation (e).

Further, when further speeding up is desired during the constant speed operation (c), the function selection button 27 is similarly turned off. However, acceleration notch 28 is OFF
In this condition, high speed operation will continue, but the acceleration notch
By turning ON 28, the speed can be increased along the acceleration line (f).

For safety, the function selection button 27 can be set only when the crane speed is zero, that is, at the time of starting.

Next, an inching procedure for short-distance driving will be described with reference to FIGS. 5 and 8.

First, the function selection button 27 is switched to the short distance. Then, similarly to the above, turn on the horizontal (running) push button PBS2 and activate the acceleration notch.
When 28 is turned on, the target speed is increased to 1/4 of the required travel distance, and when the position (g) is reached, the speed is decelerated and stopped. This means that you have traveled half the required travel distance. However, the acceleration operation time and the deceleration operation time are the same and are indicated by t ₁₁ .

This operation pattern (actually the ON time of acceleration notch 28)
t ₁₁ ) is stored in the arithmetic unit 24, and the arithmetic unit 24 calculates the stop time t ₁₃ from the cycle T in which the swing of the suspended load W returns to zero as described above.

Then, the arithmetic unit 24 accelerates and decelerates the crane according to the stored operation pattern and stops it.

However, t ₁₂ = t _{11 In} the above embodiment, the operating device 12 suspended from the club 3 is used.
Although the example of performing the operation by the push button attached to the above is shown, the operation may be performed by a remote operation by radio or an instruction by voice instead of the operation by the push button, and these can be changed without departing from the spirit of the present invention. Of course.

Further, the distance L ₁₂ between the floor surface and the sheave 8 on the lifting device side is not constant but varies depending on the state of the suspended load.
It is also possible to set by setting a suspended load height setting device 29 as shown in the figure.

The hanging load height setting device 29 is configured such that the hanging load height can be set by turning the knob 30.

〔The invention's effect〕

According to the present invention, the acceleration, deceleration, and constant speed operation speed are automatically determined based on the swing pattern of the suspended load, and the operation is performed based on this, so that the driver operates in a normal operation. It is safe because it can prevent the vibration and transfer it by only using it, and can prevent the danger due to the vibration of the suspended load.

Further, in the case of short-distance transfer, the driver remembers this by only performing an inching operation for a predetermined distance, and the operation is easy because the operation is repeated with a temporary stop according to the shake cycle.

Furthermore, the driver can switch to a constant speed of any speed or increase the speed if necessary, and these can be easily performed by the switching operation of the function selection buttons, so that normal manual operability is not disturbed. It is possible to operate by suppressing the steady rest of the crane.

[Brief description of drawings]

1 to 8 relate to an embodiment of the present invention, FIG. 1 is an overall block diagram of an overhead crane with a shake restraining operation device of the present invention, FIG. 2 is an explanatory view of an effective shake length calculation procedure, and FIG. Is an explanatory view of the principle of the driving procedure of the present invention for suppressing vibration, FIG. 4 is an explanatory drawing of a short-distance traveling procedure, FIG. 5 is a driving operation flowchart,
FIG. 6 is an explanatory diagram of a traveling pattern during non-designated operation, FIG. 7 is an explanatory diagram of a traveling pattern during normal operation, FIG. 8 is an explanatory diagram of a traveling pattern during short-distance operation, and FIG. 9 is a conventional example. FIG. 10 is an explanatory view of a shake prevention pattern, and FIG. 10 is a drawing showing an example of a suspended load height setting device. 1 is an overhead traveling crane, 12 is an operating device, 20 is a shake restraining operation device, 21 is a speed control device, 22 is a suspended load level detection device, and 23.
Is a load detection device, 24 is a computing device, 26 is a signal device, 27 is a function selection push button, 28 is an acceleration notch, and 29 is a suspended load height setting device.

Claims (1)

[Claims] 1. A speed control device capable of obtaining a substantially constant acceleration / deceleration in an overhead crane operated by an operating device,
Equipped with a device that detects the level and weight of the suspended load and a computing device. (1) For the driver to perform the shake suppression operation with acceleration / deceleration in accordance with the shake cycle (nT) of the suspended load. Buzzer that informs the driver of the constant speed operation switching timing, signal device by indicator light, etc. (b) Calculation to synchronize the acceleration / deceleration time with this shake cycle to regulate the constant speed operation speed according to the shake cycle (nT) of the suspended load Device (2) The device has an arithmetic unit that remembers the inching operation of the driver for short-range shake suppression operation, and repeatedly operates at a timing calculated from the shake cycle (nT) of the suspended load, and each of the above devices An overhead crane with a shake suppressing operation device, which is equipped with a function selector for switching operation so as to selectively perform the operation with a normal operation device.