JPS605517B2 - Crane positioning control device - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a crane positioning control device, and is particularly suitable for application to a crane having a flexible traveling girder. Cranes generally consist of a hoisting rock, a girder, and a club, but long-span overhead cranes or bridge-type cranes use a flexible horizontal structure, and the traveling drive of these cranes is
A split drive type as shown in the figure is common. In Fig. 1, la and lb are running rails, 2 is a girder,
3 is a club, 4 is a hoisting rock and the center of a hanging device that can be lifted onto it, 5a and 5b are drive gears, 6a and 6b are running wheels,
7a, 7b are running drive shafts, 8a, 8b are running motors (DC motors or AC wound type transfer motors are used), 9
10a and 10b are brakes for stopping. However, positioning control is performed separately and independently for each of the 20 drive systems. Therefore, in Fig. 1, for example, parts of the drive system on the left side are indicated by the subscript a.
The parts of the drive system on the other side, that is, on the right side, are shown with a suffix b added to the reference numeral. 5 The second positioning control device for such a split drive type crane
There is one shown in the figure. In the figure, 11 is a speed control device composed of a thyristor device, 12 is a brake contactor, 13 is a position detector that detects the crane position, and 14 is a target command 0 command position Z and a current position signal obtained by the position detector 13. Perform a comparison operation with Y,
This is a speed command device that outputs a speed command as shown in FIG. 3 to the speed control device 11. In addition, in Fig. 3, the horizontal axis is the distance L, which is the difference between the target command position Z and the current position signal Y, and
The vertical axis represents the speed command C. When the difference distance L is within a predetermined value, the speed command device 14 sends out a speed command proportional to the distance L, and in response, the difference distance L When exceeds the above-mentioned predetermined value, the speed command device 14 sends out a speed command of a constant value. The positioning control device shown in FIG. 2 has a position detector 13 for detecting the current position of the crane in only one drive system (that is, the left wheel drive system in FIG. 1), and based on the detected output, the following It works like this. First, when the target command position signal Z is given to the speed command device 14, the speed command device 14 calculates the difference distance L by calculating the following equation. L=Z-Y, (1) Then, the speed command device 14 gives a speed command C having the relationship as shown in FIG. 3 to the speed control device 11 in response to this distance L'. At the same time, the solenoid 12 of the brake release contactor 12
By energizing X, the brakes 10a and 10b are released and the crane starts moving in the direction of the target position Z. Eventually, when the difference distance L becomes 0, the speed command device 14 sets the speed command C to 0, and the brake solenoid 12×
is de-energized and the brakes 10a and 10b are tightened, thereby stopping the crane. However, cranes suffer from meandering caused by the gap between the distance L value and the wheel collar, deflection in the crane's travel direction, etc., as well as variations in the brake torque applied to both wheels when stopped, and variations in brake operating time. Therefore, even if the vehicle is stopped using the split drive system as described above, it is unavoidable that a deviation Δ1 will occur in the positions of the left and right legs in FIG. Figure 4 shows this, and the deviation of both legs when stopped is △1.
If this occurs, the center 4 of the hanging tool will be shifted from the target position Y by a deviation Δm expressed by the following equation, making it impossible to perform accurate positioning. △m: △1・ki.・・・．・・・

[2} Here, X is the position of the crane club (left running rail la
distance taken), S is the span of the crane. In Fig. 4, Y is the target position for the left leg, and Y is the target position for the left leg.
2 is the position next to the right side when the deviation is 0 when the left leg reaches the target position Y, and Y2m is the position of the right side when the deviation is not 0 due to meandering when the left leg reaches the target position Y. The position △1 indicates the positional deviation between the left and right legs of the crane girder, respectively. Also, 2' indicates the state of girder 2 when the deviation occurs, and 3
' and 4' indicate the condition of the crane club at this time and the center of the hanging odor, respectively. Since the positioning device of the subordinate crane shown in Figs. 1 to 3 is constructed as described above,
Accurate positioning is not possible. In order to solve this problem, conventional methods have been to increase the rigidity of the crane or adopt a mechanical structure that reduces the amount of meandering described above, while at the same time, positioning control such as the one shown in Fig. equipment has also been adopted.
In the case of FIG. 5, speed control devices 11a and 11b are prepared for each of the drive motors 8a and 8b of both legs, and position detectors 13a and 13b and finger speed generators 9a and 9 are provided for each of both legs.
b, and brake application contactors 12a and 12b are provided. In FIG. 5, parts corresponding to those in FIG. 2 are designated by the same reference numerals. In FIG. 5, the speed command device 14 compares and calculates the target command value Z based on the output signal Y of the position detector 13a of one of the two legs, for example, the left leg, and generates a speed command C2 as shown in FIG. Both leg speed control devices 11a, 1
1b, thereby causing the drive motors 8a and 8b to start positioning and driving to the target position Z by the speed control devices 11a and 11b, respectively. At this time, the speed command device 14 includes both leg position detectors 13a,
The magnitudes of the output signals Y, Y2 obtained in step 18b are compared, and based on the deviation between the two, correction inputs C3 and C4 as shown in FIG.
This causes the leading electric motor 8a or 8b to decelerate, and conversely the lagging electric motor to accelerate. However, although this method performs positioning while keeping the deviation of both legs to zero during running, it requires speed control devices 11a and 11b to be provided for each drive motor 8a and 8b, and tracking performance is poor. The problem is that the motor capacity must be selected with a margin in order to improve the performance. Further, even if the legs are always aligned, there is a problem that deviation occurs between the legs when the brakes 13a and 13b are used to stop the legs at the final position. The present invention was made in order to eliminate the drawbacks of such conventional crane positioning devices. Therefore, in addition to performing a positioning and stopping operation using the same method as the subordinate method described above for Figures 2 and 3, the brakes on the reference side are tightened only if there is a deviation by comparing the positions of both legs. The purpose of this invention is to provide a positioning control device that can release the brake on the anti-reference side and drive the electric motor in the direction where the deviation of both legs becomes zero, thereby realizing accurate positioning with a simple configuration. To explain one example of the invention in detail, the crane positioning device according to the invention has a configuration as shown in Fig. 8. In Fig. 8, parts corresponding to those in Fig. 2 are denoted by the same reference numerals. , has a configuration different from the conventional device shown in FIG. 2 in the following points.In the case of FIG.
, 21b is provided for each breast, which is different from the case shown in FIG. 2. Next, in the case of Fig. 8, one leg side (for example, the first
The drive motor 8a is set with the left leg (in the figure) as the reference side.
, and the brake 10a thereof is provided with a contact point 22a of an electromagnetic contactor 22 for position correction, and this electromagnetic contactor 22 for position correction is excited by the speed command device 14, so that the electric motor 8a and the brake of the reference example are fixed at the time of position correction. 10
a is not operated. In addition to this, in the case of FIG. 8, as the speed command device 14,
This differs from the case shown in FIG. 2 in that the positions of both legs are compared and calculated, and if there is a deviation in the comparison result, the above-mentioned position correction electromagnetic contactor 22 is operated to excite it. In the embodiment shown in FIG. 8, yield motors are used as drive motors 8a and 8b, 23a and 23b are secondary resistors thereof, and 24a and 24b are secondary short-circuit contactors, respectively. The positioning control device according to the present invention shown in FIG. 8 operates as follows, as shown in the flow chart of FIG. First, start at step S and then speed command device 1.
When the target position command Z is given to 4, the speed command device 1
4 performs the following calculation using the current value signal Y obtained from the reference side position detection amount 21a and the target command Z in step S2. Distance L=Z-Y. ......{
31 If the distance L of this difference is not 0, a speed command C5 as shown in FIG. 9 is outputted to the speed control device 11 in step S3, and at the same time, the brake electromagnetic contactor 12 is closed. As a result, the brakes 10a, 10b are released, the drive motors 8a, 8b start operating, and the crane moves in the direction of the target position Z in step S4. As a result, when the position signal Y reaches the target position Z, the speed command C
S becomes 0, and the process returns to step S2 to determine this.
Thus, in step S5, the brakes 10a, 10b
is tightened by opening the brake electromagnetic contactor 12, and the crane stops (step S6). At this time, the speed command device 14 compares the position signals Y and Y2 obtained by the position detectors 21a and 21b on the reference side and the anti-reference side at the time of stopping, respectively, in the next step S7, and if they match, the positioning is completed. Then, the program is terminated (step S9). However, in reality, as described above with reference to FIG. 4, the positions of the reference side and the anti-reference side are shifted. Here, the anti-reference side refers to the leg on the opposite side (in this example, the right leg) from one of the legs that has been determined as the reference side (in this example, the left chest in Figure 1). It refers to a system. In this way, deviation △ on both legs
1, the speed command device 14 opens the contactor 22a in step SIO', and then performs the following calculation on the target position Z and the opposite reference side position signal Y2 in the next step SII. ta Distance M=Z-Y2...
・■ When it is determined that this distance M is not 0, the speed command C6 shown in FIG. 9 is output again to the speed control device 11, thereby releasing the brake and causing positioning to be performed in step SI2. However, at this moment, in the previous step SI, the speed command device 14 has already activated the reference side electric motor 8a and the brake 1.
0a is separated by exciting the electromagnetic contactor 22, the electric motor 8b and brake on the anti-reference side
Only the wheels enter the operating state, and only the anti-reference side moves using the reference side wheels as a fulcrum (step SI3). As a result, when the distance M based on formula '4) becomes 0, step SI
This is determined by returning to step I, and in the next step S14, the speed command device 14 stops the non-reference side electric motor 8b and tightens the brake 10a, thus stopping the crane (step S15) and completing the position in step S8.
Then, the process moves to step S9, which ends the program. In the above-described embodiment, the present invention was applied to a crane with a split travel drive system, typically a two-motor type, but it is also applicable to a crane with a single motor drive drive system as shown in FIG. Also, by using a positioning control device configured as shown in FIG. 12, the same effects as in the above embodiment can be obtained. As shown in FIG. 11, in the No. 1 electric motor crane, the output shaft of a common traveling electric motor 31 is directly connected to, for example, the anti-reference side traveling drive shaft 7b, whereas a clutch 32 is connected to the reference side traveling drive shaft 7a. It has the same configuration as the case in FIG. 1 except that it is connected through the wire. Note that corresponding parts are indicated with the same reference numerals. The positioning control device for this, as shown in FIG. 12 corresponding to FIG.
Enter. On the other hand, a clutch 3 for driving the reference side traveling drive shaft 7a
A position correction electromagnetic contactor 2 is connected between the drive power source 33 and the drive power source 33.
The structure is the same as that shown in FIG. 8 except that 2a is inserted. As described above, according to the present invention, in order to reduce the deviation of both legs to zero when stopped, the drive system is configured so that the reference side wheel is braked and only the anti-reference side is moved using this as a fulcrum. A device capable of accurate positioning can be easily realized by simply adding an extremely simple configuration to a conventional device, and there are great practical benefits in that it can be easily applied to the automation of cranes that have not conventionally performed automatic positioning.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing a two-motor traveling drive type overhead crane to which the present invention can be applied, Fig. 2 is a block diagram showing a conventional positioning control device, and Figs. 3 and 4 are explanations of its operation. 5 is a block diagram showing a positioning control device conventionally employed to solve the drawbacks of FIG. 1; FIGS. 6 and 7 are curve diagrams for explaining its operation; FIG. 8 is a block diagram showing one example of a crane positioning control device according to the present invention, FIGS. 9 and 10 are curve diagrams and flow charts for explaining its operation, and FIG.
1 and 12 are a schematic diagram and a block diagram showing an embodiment in which the present invention is applied to a single-motor travel drive system crane. la, lb...Traveling rail, 2...Girder, 3
...Club, 5a, 5b... Drive gear
6a, 6b... Running wheels, 7a, 7b...
... Traveling drive shaft, 8a, 8b, 31... Traveling electric motor, 9... Fingertip generator, 10a, 10b...
...Stopping brake, 11, 11a, 11b...
・Speed control device, 12...brake contactor, 13, 21a, 21b...position detector, 14...
...Speed command device, 22...Magnetic contactor for position correction,
23a, 23b... Secondary resistor, 24a, 24
b...Secondary short circuit contactor, 32...Clutch. Figure 1 Figure 2 Figure 3 Figure 4 Figure 10 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 11 Figure 12

Claims (1)

[Claims] 1. In a crane that is movable by connecting driving shafts to the wheels of both the left and right legs, a position detector is provided for each of the legs, and one of the legs is set as a reference side, and the The brake contactor commonly provided on the brake on the reference side, the contact of the electromagnetic contactor for position correction provided on the brake on the reference side, the detection position of the position detector on the reference side, and the target command position match. When the brake contactor is operated to apply the brakes on the reference side and anti-reference side, if the detected position of the position detector on the anti-reference side and the target command position do not match, they match. and a speed command device that releases the braking operation of the brake on the anti-reference side by operating the electromagnetic contactor for position correction until the position is corrected, thereby driving the travel drive shaft on the anti-reference side. Crane positioning control device.