JP2801584B2 - Quantitative cut-out control device for bucket wheel type reclaimer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bucket wheel type reclaimer for quantitatively controlling a fixed amount of bulk material such as coal or iron ore by a boom swing type bucket wheel reclaimer.

[0002]

2. Description of the Related Art Conventionally, a bucket wheel type reclaimer as shown in FIG. 4 has been provided in a raw material yard or the like of a steel mill. Raw materials such as coal and iron ore are cut out by a rotating bucket wheel 1 and conveyed from an on-machine conveyor 2 via a ground conveyor 3. A weighing machine 4 is provided in the middle of the on-board conveyor 2, and measures the amount of material cut out. The operation from the cab 5 controls the hoisting device 6, the turning device 7, and the traveling device 8. The traveling device 8 is shown in FIG.
On a rail 9 extending perpendicular to the plane of the drawing. A load pile 10 is formed on the side of the rail 9, and the base end of a boom 11 to which the bucket wheel 1 is mounted at the tip is supported by a reclaimer main body 12. The position at which the bucket wheel 1 acts on the material pile 10 is changed by the undulating device 6 and the turning device 7 provided between the boom 11 and the reclaimer main body 12. The reclaimer main body 12 is also provided with a chute 13 for moving a conveyed object from the on-machine conveyor 2 provided on the boom 11 to the ground conveyor 3. Since the bucket wheel 1 is mounted on the tip of the boom 11, the balance weight 14 is mounted on the opposite side of the tip where the bucket wheel 1 is mounted on the boom 11 in order to smoothly turn by the turning device 7. ing.

[0005] FIG. 5 shows a state in which loose objects are cut out by a bucket wheel type reclaimer. Reclaimer body 12
Travels in the direction of the rail 9 and turns the boom 11 to cut out the conveyed material from the conveyed material pile 10. The boom 11 is driven to turn in the turning direction 15 or the turning direction 16. The reclaimer body 12 is configured such that the boom 11 is moved, for example,
After the turning in the direction of 5, the vehicle travels forward by a certain distance, and then turns the boom 11 in the direction of the turning direction 16. In such a bucket wheel type reclaimer, since the conveyed material between the previous tooth tip 17 and the current tooth tip 18 is cut out, the cutting amount of the bucket wheel 1 changes depending on the turning angle θ. In order to prevent the amount of cutout from the reclaimer from fluctuating, the boom turning speed is changed in proportion to 1 / cos θ with respect to the turning angle θ of the boom 11, and as shown by hatching, It is necessary to control the conveyed material to be cut out within a certain time so as to have a constant flow rate on a volume basis.

[0004] Only the stabilization of the cut-off flow rate by the programmatic operation as described above causes differences in the composition of coal and iron ore,
In addition, it becomes difficult to stabilize disturbance factors such as bulk specific gravity fluctuation caused by whether these coals or iron ores have been piled on the upper or lower part of the pile and how long they have been piled.

In Japanese Patent Publication No. 61-32214, the amount of cut-out from a weighing machine provided in the boom conveyor 2 is sampled at predetermined time intervals, and the sampled flow rate value is compared with a preset cut-out amount. The prior art which calculates and controls the turning speed of a boom is disclosed. In addition, Japanese Unexamined Patent Publication
No. 116024 discloses a prior art in which a load detector is installed on a bucket wheel, and a boom turning speed is adjusted using a signal from the load detector and a cutout amount from a weighing machine provided on a boom conveyor. ing.

[0006]

The bucket wheel type reclaimer as shown in FIG. 4 can directly measure the flow rate of bulk material that is cut out only by the weighing machine 4 provided in the middle of the on-board conveyor 2. The flow rate is delayed by the time required for being conveyed by the on-board conveyor 2 to the position of the weighing machine 4 after being cut out by the bucket wheel 1. The prior art of Japanese Patent Publication No. 61-32214 is a known technique which is generally considered to be effective for controlling a control system including a dead time in consideration of a dead time based on a delay until measurement by a weighing machine. Based on the sample value control, the amount of cutout is quantified. However, the dead time until the cutout amount can be measured by the weighing machine occupies a considerably larger ratio than the time during which the boom is turning. For example, when cutting out the conveyed material from the uppermost stage of the conveyed material pile 10, the ratio is about 1: 2 to 3. Therefore, even if the control is started after correcting the dead time, the turning of the boom ends immediately after that, and the signal from the weighing machine directly determines the amount of cutout every moment while the boom is turning. Controlling is not as effective.

In the prior art of Japanese Patent Application Laid-Open No. 4-116024,
Control for stabilizing the cut-out amount is performed by detecting the load on the bucket wheel. However, the bucket wheel driving force is only indirectly related to the cutout amount. If the instantaneous driving force is detected and the turning speed of the boom is adjusted each time, it is very effective to suppress the fluctuation of the instantaneous cutting amount, but the flow rate set in advance,
For example, it is difficult to maintain flow rates on a Ton / Hour basis. In particular, when the reclaimer is operated under the rated capacity, for example, at a load of 60% or 30%,
Since the bucket wheel driving power is an indirect amount relative to the cutout amount, it is difficult to stably obtain the set cutout amount. In the prior art of Japanese Patent Application Laid-Open No. 4-116024, in order to perform stable cutting in a region where the turning angle θ becomes large and a loose object cannot be sufficiently secured, cutting is performed only once in a plurality of predetermined times. There is also disclosed a configuration for performing control so as not to perform the operation. This method suggests an operation method in consideration of actual cutting by the reclaimer, and is considered to be one method of stabilizing the flow rate in a portion where the cargo shape is unstable. It is different from the purpose.

An object of the present invention is to clearly separate the control purpose and the applicable range, and to reduce the momentary flow fluctuation during turning while keeping the average cutout amount for each swing of the boom to the set value. It is an object of the present invention to provide a bucket wheel type reclaimer which can perform a fixed amount cutout.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a bucket wheel provided at the tip side of a boom capable of turning and raising and lowering is rotated to remove a predetermined amount of loose material from a pile on the side in the traveling direction. In a fixed quantity cutting control device of a bucket wheel type reclaimer, which cuts out and conveys the boom conveyer attached to the boom to the base end side of the boom while detecting the cutout amount with a weighing machine provided in the middle of the boom conveyor, A first control means for detecting a boom turning angle θ with respect to the angle of rotation and deriving a control output signal representing a reciprocal 1 / cos θ of a cosine value of the turning angle θ, and a cutout amount detected by the weighing machine, A second control means for averaging in a range excluding a portion where the cargo shape is unstable, subtracting the average value from a set value of the cutout amount, and deriving a control output signal representing a ratio of a difference to the set value. , The bucket wheel drive power and the payout amount are averaged over a range excluding the portion where the stow shape is unstable at the side end of the boom turning range, and the payout amount is set from the average bucket wheel drive power value and the average payout amount. A third control means for calculating a bucket wheel driving power (target value) with respect to the target value, subtracting the target value from the actually detected bucket wheel driving power value, and calculating a control output signal using a ratio of a difference to the target value. And turning drive means for adding a control output signal from the second control means and a control output signal from the third control means to a control output signal from the first control means, respectively, and turning and driving the boom in accordance with the added control output signal. A fixed quantity cutting control device for a bucket wheel type reclaimer characterized by the above-mentioned. According to the present invention, the first control unit derives a control output signal representing 1 / cos θ in order to make the cut flow rate constant by compensating for the change in the cut amount of the bucket wheel due to the boom turning angle θ. The second control means averages the detected flow rate of the weighing machine for detecting the flow rate of loose objects conveyed by the boom conveyor, and derives a control output signal that reduces the deviation of the cutout amount from the set value. The third control means utilizes the feature that the detection of the driving power of the bucket wheel is effective in pushing in the instantaneous and instantaneous cutout amount fluctuations, while overcoming the drawback that the drive power is an indirect amount to the cutout amount. For this purpose, the bucket wheel driving power (target value) corresponding to the cut-out amount setting value is calculated for each boom turn, and a control output signal is derived to make the actual driving power coincide with the target value driving power. . The control output signals from the first control means, the second control means, and the third control means are added and the turning drive means drives the boom to turn, so that the instantaneous fluctuation width of the cut-out amount during turning is obtained. Can be reduced as much as possible, and the average flow rate cut out during one turn can be made to match the cutout amount set in advance.

In the present invention, a correction coefficient is calculated by multiplying a control output signal of the second control means by a coefficient, and the turning drive means corrects an initial speed at the time of turning of the boom according to the correction coefficient. I do. According to the present invention, the initial speed of the drive for turning the boom by the turning drive means is corrected according to the correction coefficient calculated by the second control means and the control output signal from the third control means. Cutting can be started at a turning speed suitable for the bulk specific gravity of the loose object, and stable cutting with little variation as a whole can be performed.

Further, in the present invention, the second control means individually calculates the correction coefficient according to a difference in the boom turning direction, and the turning drive means controls the boom turning derived by the second control means. It is characterized in that the initial speed is corrected using a correction coefficient suitable for the direction. According to the present invention, the second direction can be changed according to the difference in the turning direction of the boom.
A correction coefficient is calculated by the control means, and the turning drive means corrects the initial speed by using a correction coefficient suitable for the turning direction, so that it corresponds to a difference in cutout amount caused by a mounting position of the bucket wheel with respect to the boom. Thus, the variation in the cutout amount can be reduced.

[0012]

FIG. 1 shows a schematic electrical configuration of a quantitative cutout control device 20 according to an embodiment of the present invention. The target cut-out amount of the bucket by the reclaimer is set in the cut-out amount setting device 21. The cut-out amount actually conveyed on the on-machine conveyor provided on the boom is
It is measured by the weighing machine 22. Since the cutout amount measured by the weighing machine 22 has a time delay, a bucket wheel load detector 23 is provided to detect an instantaneous change in the cutout amount. Bucket wheel load detector 23
Detects the driving force of the bucket wheel by detecting the electric motor current in the case of electric motor drive, the hydraulic pressure at the hydraulic motor inlet in the case of hydraulic drive, and the like.

[0013] In order to avoid averaging of the cutout amount at a portion where the cutout amount is not sufficiently obtained, for example, at the end of a pile of conveyed goods, the cutout amount setting unit 21 is set in the ratio setting unit 24. To output a predetermined value that is smaller than the set value at a fixed rate,
For example, a ratio such as 80% is set. Ratio setting device 2
4 and the output of the weigher 22 are compared by the comparator 25. The comparator 25 derives a sampling start signal after the flow rate measured by the weigher 22 becomes larger than the output value output from the ratio setting device 24.
The first averaging circuit 26 responds to the sampling start signal, integrates the flow rate signal from the weighing machine 22 for a certain time,
The signal is averaged over the required time to derive a signal representing the average value.

In response to the averaging command, the second averaging circuit 27 averages the power signal from the bucket wheel load detector 23 in a range excluding a portion where the cutout amount is unstable at the side end of the boom turning. , A signal representing the average value is derived. The third averaging circuit 28 responds to the averaging command in consideration of the delay time of the weighing machine, and outputs the flow rate signal from the weighing machine 22 to a region excluding a portion where the cargo shape is unstable at the side end of the boom turning. , And averaged over the required time to derive a signal representing the average value. The set value of the cutout amount is also given to the subtractor 29, and the difference from the average value of the cutout amount derived from the first averaging circuit 26 is calculated. The difference calculated by the subtractor 29 is the first
The ratio is supplied to the ratio calculator 30 and the ratio based on the set value of the cutout amount set in the cutout amount setting device 21 is calculated. The ratio calculated by the first ratio calculator 30 is
Given to one. Using the average driving power of the bucket wheel derived from the second control means 46 and the average payout quantity derived from the third control means 47, the target driving power calculation circuit 35 generates a signal corresponding to the signal from the cutout amount setting device 21. Is calculated. The target driving power calculated by the target driving power calculation circuit 35 is supplied to a subtractor 36, and the difference from the instantaneous and instantaneous bucket wheel driving power obtained from the bucket wheel load detector 23 is calculated. The difference calculated by the subtractor 36 is provided to a second ratio calculator 37.
The second ratio calculator 37 calculates a correction ratio based on the target drive power obtained from the target drive power calculation circuit 35 when the value becomes equal to or greater than a predetermined value. Second ratio calculator 3
In other words, the calculation function of No. 7 utilizes a known technique called a ratio calculation unit with a dead zone. The correction signal of the second ratio calculator 37 and the control output signal from the amplifier 31 are multiplied by a multiplier 38 to generate a control output.

The reference swing speed control device 32 is provided with the boom swing angle θ detected by the swing angle detector 33 and calculates 1 / cos θ, which is the reciprocal of the cosine value of the swing angle θ, in the design calculation of the bucket wheel type reclaimer. A reference turning speed signal obtained by multiplying a base turning speed theoretically calculated in advance sometimes is calculated. Reference turning speed control device 32
Are supplied to an amplifier 31 and corrected according to the ratio from the first ratio calculator 30. Swing drive 34
Drives the boom swing based on the swing speed command obtained by adding the control output signal from the amplifier 31 and the control output signal from the multiplier 38 by the adder 39.

The reference turning speed control device 32 and the turning angle detector 33 constitute a first control means 45, and the cutout amount setting device 21, the weighing machine 22, the ratio setting device 24, the comparator 25, the first
The averaging circuit 26, the subtractor 29, the first ratio calculator 30 and the amplifier 31 constitute a second control means 46, and include a second averaging circuit 27, a third averaging circuit 28, a target drive power calculation circuit 35, , A second ratio calculator 37, a multiplier 38,
The adder 39 forms the third control means 47.

FIG. 2 shows an operation related to the second control means 46 shown in FIG. Start the operation from step a1,
The set value Q0 is set in the cutout amount setting device 21. In step a2, the ratio setting unit 24 is multiplied by a preset ratio, and a set value Q3 smaller than the cutout amount set value is derived for comparison. In step a3, the transport amount Q1 measured by the weighing machine 22 is given. In step a4, the comparator 25 compares the transport amount Q1 from the weighing machine 22 with the ratio setting unit 24.
Is compared with the set value Q3. The transport amount Q1 is equal to the set value Q
When the value becomes 3 or more, a sampling start signal is derived in step a5, and the integration processing by the first averaging circuit 26 is started in step a6, and the integrated value Q2 is calculated. After the predetermined time t1 has elapsed in step a7, in step a8, an average calculation process is performed by the first averaging circuit 26, and the average value is calculated by QA = Q2 / t1. In step a9, the difference QB between the set value Q0 of the cutout amount and the average value QA
= Q0-QA is calculated. In step a10, the first
The ratio calculator 30 calculates the ratio QC = QB / Q0.

In steps a11 to a15, as the operation of the amplifier 31 shown in FIG. 1, switching is performed in steps a11 and a12 in accordance with the turning direction of the turning drive unit 34. Switching between the multiplication and the coefficient multiplication for the left turn in step a14 is switched. Steps a13 and a1
4 is multiplied by the ratio QC determined in step a10.
= QB / Q0, the adjustment constants α1 and α2 are multiplied by a coefficient every right turn or left turn, and a correction signal is issued. Amplifier 31
In step a15, the reference turning speed value from the reference turning speed control device 32 is compared with the value of step a13 or step a13.
The control output signal is output by multiplying the multiplied value obtained by multiplying the coefficient in the right turn or the left turn obtained in 14 by the coefficient. From the beginning of one swing, a right turn correction signal α1 × Q subjected to coefficient multiplication processing to set an initial speed suitable as a turn speed.
C and the left-turn correction signal α2 × QC are respectively stored and used for the next right-turn and left-turn. This storage process is also included as part of the function of the amplifier 31.

FIG. 3 shows an operation state of the fixed quantity extracting device 20 of FIG. (A) shows the setting state of the cutout amount. Time t
0 and a fixed amount of cutout (hereinafter “Ton / Hour”
/ H ") is set and cutting starts.
(B) shows a change in the cutout amount assuming that the control of the cutout amount is not performed. This change in the cut-out amount corresponds to the distribution of loose objects stored in the pile of conveyed articles and the like. (C)
Indicates the output of the weighing machine when cutting out in (b). The flow rate corresponding to the cutting amount cut by the bucket wheel is detected with a delay of a predetermined time.

(D), (e) and (f) show the outputs from the comparator 25, the first averaging circuit 26 and the first ratio calculator 30 which constitute the second control means 46, respectively. The comparator 25 is off until the time t2 when the output from the weighing machine 22 detected from the time t1 becomes larger than the output from the ratio setting unit 24, and turns on after the time t2. The sampling by the first averaging circuit 26 is performed for the time width w1 and ends at the time t3. Comparator 25
Changes from ON to OFF at time t4 when the output from the weigher 22 becomes smaller than the output from the ratio setting unit 24. The output (f) of the first ratio calculator 30 is OFF at time t4 when the turning direction is output from time t3 and the turning direction is reversed.
Changes to

(G) is an output of the second control means 46, which is a signal obtained by correcting the output of the first control means 45 by using the output of the amplifier 31. From time t1 to time t4, the control for stabilizing the cutout amount for one swing of the boom ends. Control for the next swing is performed in the same manner as described above. In other words, sampling is performed by weigher 2
The process is started at time t5 when the output from the second unit 2 becomes larger than the output from the ratio setting unit 24. In response to the sampling start signal from time t5, sampling by the first averaging circuit 26 is performed for a time width w1 until time t6. At time t6, the difference between the set value of the cut-out amount and the average value is generated by the operation of the subtractor 29, so that the first ratio calculator 30 outputs the calculated value (f) of the ratio. At time t7 when the turning of one swing ends, the output from the first ratio calculator 30 also becomes zero. This output is effective during the next turn in the same direction until the sampling is completed after the start of the turn and a new correction coefficient is calculated.

(H), (i) and (nu) are the bucket wheel load detectors 23 included in the third control means 47,
The changes in the outputs from the target drive power calculation circuit 35 and the subtractor 36 are shown. The output from the bucket wheel load detector 23 shown in (h) changes while maintaining a certain relative relationship with the cut-out amount, but falls below the no-load drive power for starting the bucket wheel in a no-load state. Absent. (I) shows the target drive power, and after a predetermined time from the start of the left and right turning, set cutout using the average drive power from the second averaging circuit 27 and the average cutout amount from the third averaging circuit 28. It is calculated according to the quantity.

(Nu) shows the difference between the output of the subtractor 36 and the instantaneous load detection value from the target driving power. (Le)
Is the output of the multiplier 38, which is obtained by multiplying the output of the second control means 37 by multiplying the output of the second control means with a dead zone. (E) Adds the output of the multiplier 38 to the output of the second control means at the output of the adder 39, and gives a command value to the turning drive unit 34 as the output of the third control means. As a result, the cutout amount becomes as shown in (W), and stable cutout is performed.

[0024]

As described above, according to the present invention, the first control means for stabilizing the flow rate on a volume basis in order to prevent the depth of cut of the bucket wheel from varying due to the turning angle θ of the boom. A second control means for stabilizing the cut-out amount on a weight basis with respect to disturbance factors such as a change in the bulk specific gravity of the cut bulk material; The third control means is provided, respectively, and the installation purpose and the applicable range can be clearly separated from each other and used separately, so that loose objects can be stably cut out with a preset cutout amount.

Further, according to the present invention, the initial speed of the boom turning is corrected in accordance with the correction coefficient calculated in the preceding swing. Can be started.

Further, according to the present invention, it is possible to select an appropriate initial speed based on the difference in the mounting position of the bucket wheel with respect to the boom, and to suppress the variation in the cutout amount due to the difference in the turning direction.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic electrical configuration of a quantitative cutout control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a second control means 42 in FIG.

FIG. 3 is a time chart illustrating an operation state of the embodiment of FIG. 1;

FIG. 4 is a schematic front view of a bucket wheel type reclaimer.

FIG. 5 is a simplified plan view showing a cut-out state of the bucket wheel type reclaimer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 fixed amount cutout control device 21 cutout amount setting device 22 weighing machine 23 bucket wheel load detector 24 ratio setting device 25 comparator 26 first averaging circuit 27 second averaging circuit 28 third averaging circuit 29 subtractor 30 1 ratio calculator 31 amplifier 32 reference turning speed control device 33 turning angle detector 34 turning drive device 35 target drive power calculation circuit 36 subtractor 37 second ratio calculator 38 multiplier 39 adder 45 first control means 46 second Control means 47 Third control means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-116024 (JP, A) JP-A-59-223627 (JP, A) JP-A-4-5425 (JP, U) 32214 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) B65G 65/00-65/22

Claims (3)

(57) [Claims] 1. A bucket wheel provided on a tip end side of a boom capable of turning and raising and lowering is rotated to cut out a predetermined amount of cutouts from a pile on a side in a traveling direction and attached to the boom. Detects the swing angle θ of the boom with respect to the traveling direction using a bucket wheel type reclaimer fixed-quantity cutout control device that conveys while detecting the cutout amount with a weighing machine provided in the middle of the boom conveyor at the base end of the boom conveyor. A first control means for deriving a control output signal representing a reciprocal 1 / cos θ of the cosine value of the turning angle θ; and a cutout amount detected by the weighing machine, the load shape being unstable at a side end of the boom. Second control means for averaging in a range excluding the portion, subtracting the average value from the set value of the cutout amount, and deriving a control output signal representing a ratio of a difference to the set value; The power and payout amount are averaged in a range excluding a portion where the stow shape is unstable at the side end of the boom turning range, and the bucket wheel drive for the average bucket wheel drive power value and the set value of the payout amount based on the average payout amount. Third control means for calculating a power (target value), subtracting the target value from the actually detected bucket wheel drive power value, and calculating a control output signal using a ratio of a difference to the target value; Adding a control output signal from the second control means and a control output signal from the third control means to a control output signal from the control means,
A swing drive means for swing-moving the boom in accordance with the added control output signal. 2. The method according to claim 1, wherein the control output signal of the second control means is multiplied by a coefficient to calculate a correction coefficient, and the turning drive means corrects an initial speed when the boom is turning according to the correction coefficient. Item 3. A fixed quantity cutting device for a bucket wheel type reclaimer according to Item 1. 3. The method according to claim 1, wherein the calculation of a correction coefficient obtained by multiplying a control output signal of the second control means by a coefficient is performed individually in accordance with a difference in a turning direction of the boom. 3. The fixed-quantity cut-out device for a bucket wheel type reclaimer according to claim 2, wherein: