JPS6160033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for automatically operating an overhead traveling crane with a bucket.

It is very difficult to transport an object using an overhead crane, and to bring it to a target position with few errors, and then to land it on the floor, which requires the skill of a skilled operator.

The present invention provides an automatic operation method for an overhead traveling crane with a bucket, which can be easily operated by anyone without being a skilled operator, and can be used without special modification of the existing crane. It is.

In order to achieve the above object, the present invention turns off the motor at the first detection point it passes among a plurality of detection points provided at appropriate intervals in the running direction before a stopping point, and The speed is detected from the time it takes to pass a predetermined detection point and the distance between the detection points, and the first brake operation time required to reduce the speed from the detected speed to a constant speed is calculated from the detected speed and brake characteristics. Then, in order to stop at the stopping point, a second brake operation time to be applied before the stopping point is determined from the reduced constant speed and brake characteristics, and from the detection point to the stopping point. The second brake activation time is subtracted from the time required to calculate the final brake activation time to stop the vehicle at the stopping point, and the brakes are applied at this time.

An embodiment of the present invention will be described below based on the drawings. In FIG. 1, reference numeral 1 denotes an overhead traveling crane that travels in the direction of arrow y over a workshop pit 2, 3 a bucket truck that travels over the crane 1 in the direction of arrow x, 4 a hopper provided on the side of the pit 2, LS ₁
~ _LS4 and _LS1 '~ _LS4 ' are limit switches provided at predetermined intervals on the fixed side in parallel to the crane traveling direction y, and are symmetrical with respect to the position X corresponding to the center 4a of the hopper 4. The larger the subscript number, the closer it is to position X.
LS ₀₁ to LS ₀₄ are limit switches provided on the crane 1 at predetermined intervals in parallel to the bogie traversal direction The larger the subscript number, the closer to position Y the one is arranged. A bucket cart (not shown) suspended from the bucket cart 3 is manually operated by a driver to land on an object in the pit 2 to be transported, grab the object, and hoist it up. Next, it is automatically transported toward the hopper 4 via the automatically operated crane 1 and the traversing trolley 3, and is placed almost above the center 4a of the hopper 4 by a sequence control device using the limit switches and a computer. was arrested and released.

Here, as a method to stop the bucket cart from shaking to a minimum while ensuring that the fixed points X and Y at the destination are correct, the speed of the bucket cart moving to the fixed points X and Y is detected, and the time required to apply the brakes in accordance with the speed is determined. A method is in place to automatically determine the This makes it possible to suppress lateral vibration of the bucket.

Next, its operation will be explained with reference to FIGS. 3 and 4. In Figures 3A and 3B, when crane 1 or truck 3 passes point a corresponding to limit switch LS ₁ or LS ₀₁ at speed V ₁ or V ₂ (only the crane will be explained below), this is detected by limit switch LS ₁ . Then, the motor is turned off via the computer 5. The crane 1 then coasts between point a and point c corresponding to limit switch LS ₃ , and at point c the brake is applied with a predetermined strength only for time t ₁ or t ₂ . The time t ₁ or t ₂ for operating this brake is determined by the computer 5 detecting the passing time T ₁ between point a and point c,
The speed is calculated by dividing the distance between points a and c by the passing time T ₁ , and from the speed and brake characteristics, the crane running speed V ₁ or V ₂ after the brake operation time t ₁ or t ₂ is determined as a predetermined value. is determined to be. Then V ₁
Alternatively, the crane 1, which has been decelerated to a speed of _V2 , passes the point d corresponding to the limit switch _LS4 , applies the second brake after a time _T4 , and stops at the fixed point X after a time _t5 . This time t ₅ is determined from the distance between point c and fixed point _{X or} point _d and fixed _point Activate the brakes after a time T ₄ .

In Figure 3c, when the crane 1 starts moving between points a and b and passes point b, which corresponds to limit switch LS ₂ at a speed of V ₃ , the limit switch
LS ₂ detects this and the limit switch
Since crane 1 is detected without detection by LS ₁ , the motor is turned off via computer 5 at this point. And crane 1 is at point b and c
It coasts between points and applies the brakes only for time _t3 at point c. This time t ₃ is determined by calculating the speed by dividing the distance between points b and c by the passing time T ₂ in the computer 5 as described above, and calculating the speed of the crane after the brake operation time t ₃ from the speed and brake characteristics.
V ₃ is determined to be a predetermined value. Here V ₁
It is convenient to set =V ₂ =V ₃ . Then, in the same way as described above, the second brake is activated after a time T ₃ + T ₄ after passing point c, or after a time T ₄ after passing point d, and the vehicle is brought to a stop at approximately fixed point X after approximately t ₅ . .

In Fig. 3D, the crane 1 starts moving between points b and c and passes through point c, which corresponds to limit switch LS ₃ , at a speed of V ₄ .
LS ₃ detects this and the limit switch
Since the crane 1 is detected without being detected by LS ₁ and LS ₂ , the motor is turned off via the computer 5 at this point. And crane 1 is c
It coasts between points d and d, and applies the brakes only for time _t4 at point d. This time _t4 is the distance between points c and d in the computer 5.
Calculate the speed by dividing by T ₃ , and use the speed and brake characteristics to calculate the crane speed V ₄ after brake operation time t ₄
is determined to be a predetermined value. In this case, the coasting speeds V' ₁ , V' ₂ of FIGS. 3A to 3C at this time,
It is convenient to make it approximately equal to V′ ₃ (V′ ₁ ≒V ₂ ′≒V ₃ ′). Then, in the same manner as described above, the second brake is activated after time _T4 after passing through point d, and the vehicle is brought to a stop approximately at fixed point X approximately after time _t5 .

Although the above embodiment has been described in which the vehicle is stopped at a fixed point with two braking operations, it is also possible to stop the vehicle with more braking operations.

Furthermore, if we consider the case where the motor starts in the vicinity of point a in Figures 3A and B, in the vicinity of point b in Figure 3C, and in the vicinity of point c in Figure 3D, the motor starts immediately after startup. OFF, and the movement energy to the stopping points Go to pattern.

Next, the overall operation will be explained with reference to FIG. The driver hoists up the articles with a bucket at a predetermined position in the pit 2, and then instructs to start automatic operation using a push button switch or the like. Crane 2 then starts traveling in the direction of the arrow y, and the first limit switch turns the motor on.
OFF, then the speed is detected, the brake is activated, the running stop is controlled, and finally the running is stopped at the stopping point X. On the other hand, when the hoisted bucket reaches the upper limit point, the hoisting of the bucket is stopped, the truck 3 starts moving in the direction of the arrow X, the motor is turned off with the first limit switch, the speed is detected, and the brake The traversing stop control is carried out by the operation, and the traversing is finally stopped at the stop point Y, and lowering of the bucket is started.

As described above, according to the present invention, the first brake operation time is determined by calculating the moving speed of the crane, and the brake is applied for this time to first decelerate to a constant speed and then to stop at a stopping point. By determining the second brake activation time to be applied before the stopping point, and finally applying the brake for this amount of time before the stopping point, it is possible to stop correctly at the time of stopping, compared to the generally used electromagnetic band brake. Even if it is not possible to operate in a slow, slow, and strong manner due to its structure, it can equivalently perform a slow, slow, and strong operation at the beginning and end. As a result, when a bucket tot suspended by a wire rope is moved by a crane and stopped at a target position, for example, the rolling motion of the bucket tot that occurs when the brake is applied can be suppressed by applying the brakes in a strong manner from beginning to end. Moreover, since it is only necessary to determine the time to apply the brakes from each speed and brake characteristics, it is easy to implement without requiring complicated calculations.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, FIG. 1 is a schematic diagram of an overhead traveling crane used therein, FIG. 2 is a flowchart showing the operation, FIG. 3 is a characteristic diagram explaining the brake operation, and FIG. It is a block diagram of the main part. 1...Crane, 3...Bucket trolley, 4...
...Hopper, 5...Computer, LS ₁ ~ LS ₄ ,
LS ₀₁ ~ LS ₀₄ ...Position detection limit switch.

Claims (1)

[Claims] 1. The time from when the motor is turned off at the first detection point it passes among the multiple detection points provided at appropriate intervals in the running direction before the stopping point to when the motor passes through the subsequent predetermined detection point. detecting the speed from the distance between the detected speed and the detection point, calculating the first brake operation time required to reduce the speed from the detected speed to a constant speed from the detected speed and the brake characteristics, applying the brake for the period of time, and then stopping. The second brake operation time is determined from the reduced constant speed and brake characteristics, and the second brake operation time is determined from the time required from the detection point to the stop point. An automatic operation method for an overhead traveling crane, characterized in that the final brake application point for stopping at a stopping point is calculated by subtracting the above, and the brake is applied at this point.