JPS62114614A - Method for operation control of embedment preventing type sedimented sand scraper - Google Patents

Abstract

PURPOSE:To perform scraping work under a proper load condition and to shorten the blank operation time at the start time of operation, by performing the rising/falling of a conveyor frame by an elevator through a take-up rope and performing control so as to always add tension to the take-up rope. CONSTITUTION:The load torque applied to the drive apparatus M of a bucket conveyor 5 is detected and an elevator M1 is subjected to proportional control corresponding to the magnitude of said load torque to raise and lower the conveyor frame 3 and, at the time of lowering, torque inverse proportion control is performed and, at the time of raising, torque direct proportion control is performed. Therefore, at the time of descending, the conveyor frame 3 rapidly falls when load torque is small and the descending speed thereof decreases as load torque becomes larger and, at the time of raising, the conveyor frame 3 rapidly rises as the load torque becomes larger to avoid overload and operation is performed in such a state that tension is always added to the take-up rope R.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for controlling the operation of a bucket conveyor-type siltation prevention type sediment scraper in water and sewage treatment facilities.

[Conventional technology] Conventional bucket conveyor type sand scraping machines often have shafts, sprocket wheels, conveyor frames, etc. fixed to the ground, and during heavy rains, temporary inflows of large amounts of sand and foreign matter cause them to become buried and operate. He was often incapacitated.

To solve this problem, a sinking prevention type has been developed in which the conveyor frame is suspended and swingably supported by mutually parallel front and rear links, and the conveyor frame can be raised and lowered. (For example, Utility Model No. 57111306, Utility Model No. 59-
1683, 1684, 1686, 1687, etc.) The above-mentioned known siltation prevention type sediment scraper has a conveyor frame that is swingably supported by front and rear links that are parallel to each other, so the conveyor frame can be moved to the pond bottom as needed. burying can be prevented by raising it, and
By appropriately selecting the inclination angle of the link, there are advantages such as smooth operation depending on the load.

In this type of siltation-preventing sand lifting machine, when the operation is stopped, the conveyor frame is hoisted up to a specified position and is on standby, and when the operation is started, several timers are set to [Stop → Lower → Stop → Lower...] The conveyor frame is repeatedly lowered to carry out the raking operation, and a stopper is usually provided at the lower limit position to limit the lowering. During raking work, if the raking resistance increases and the balance with the horizontal force due to the conveyor frame's own weight is lost, the suspension link swings backward and the conveyor frame rises to balance itself. .

[Problem to be Solved by the Invention 1] According to the above operating method, the amount of accumulated sediment and the operating depth of the conveyor frame are automatically balanced, and the suspension link swings backward in the event of overload. At first glance, this seems reasonable because the conveyor frame rises while retreating and is operated in a well-balanced state, but in reality, there are differences in the regional characteristics of sedimentation, and there are differences in the amount of rainfall, such as during heavy rains and sunny days. It is difficult to set a balance point due to fluctuations in the amount of sediment flowing due to differences in other environmental conditions, and the frame moves back and forth with an unbalanced amount near the balance point, which causes vibrations. These factors are also added, and this is not desirable in terms of stable operation.

Therefore, in order to avoid this situation, the conveyor frame's own weight is selected so that it sinks freely, and the suspension link is operated with the suspension link constantly in contact with the lower limit stopper. Normally, the design is such that only the vehicle moves backward.

As a result, the conveyor frame is often operated at the lower limit position regardless of the amount of sediment deposited, and when the amount of sediment increases rapidly, it cannot retreat (raise) in time and the packets become buried in the sediment, making it impossible to operate. There may also be cases where the vehicle is forced to stop operating.

As described above, it is extremely difficult to obtain an operating depth that corresponds to the amount of sediment deposited due to the balance between the conveyor frame's own weight and the load.

On the other hand, when the conveyor frame descends at the beginning of operation, the
Since the conveyor frame is gradually lowered by repeating stop, fall, stop, etc., there are various problems such as a long period of idle operation depending on the setting of the timer interval, which is also uneconomical.

[Means for Solving the Problems] This invention provides means for solving the problems of the prior art. The upper ends of links 2a and 2b of equal length are pivoted to support shafts 1a and 1b provided parallel to each other on the side and downstream sides, respectively, and the front and rear ends of the conveyor frame 3 are pivoted to the lower ends of the links 2a and 2b. to form a four-section parallelogram link, and each link node of the four-section parallelogram link is provided with a block conveyor guide subroget 4a, 4.
b, 4c, and 4d, a bucket conveyor 5 is driven by a drive device M installed on the ground, and a conveyor frame 3 can be raised and lowered by a lifting device M and a hoisting row (R) to prevent burial. In the scraping machine, the load torque applied to the drive device M is detected, and the lifting device MI is proportionally controlled depending on the magnitude of the load torque, and the lifting device MI is controlled proportionally to the conveyor frame 3 via the hoisting rope R.
The burying prevention method is characterized in that the lifting speed is controlled inversely proportional to the load torque when descending, and directly proportional to the load torque when ascending, and is operated with tension applied to the hoisting rope R at all times. The gist of the invention is a method for controlling the operation of a type sand settling machine.

[Function] First, to explain the outline of the operation of the siltation prevention type sand settling and scraping machine, when the operation is stopped, the conveyor frame 3 is raised to the position shown by the chain line by the lifting device M1 and is on standby.
It is known that when the operation starts, the bucket conveyor 5 is lowered and the height of the conveyor frame 3 is adjusted according to the load, and the bucket conveyor 5 is driven by the drive device M to scrape and discharge the sediment that has not accumulated on the bottom of the settling basin. It is as follows.

In this case, if the weight of the conveyor frame 3 is W and the angle of inclination of the suspension links 2a and 2b is θ, then the horizontal component force due to the weight of the conveyor frame is VVLanθ.
Assuming that the chain tension of the bucket conveyor 5 is T and that no tension is applied to the hoisting rope R, then W = Conveyor frame weight F = W L y nθ Horizontal component force due to controller weight T = In terms of chain tension, if FAT, the conveyor frame will fall; if F=T, if the balance is FζT, the conveyor frame will move backward and north. Therefore, if the raking resistance due to settling sand is small, the conveyor frame will descend, and if the load is appropriate, it will balance and
If it becomes overloaded, it can move backwards and rise to avoid the overload.

Theoretically, as mentioned above, it is difficult to find a stable balance point, and for some reason, if the amount of sediment suddenly increases and F<T, the conveyor It is even conceivable that the frame may not be able to avoid rising in time, and the packet may become stuck in the sand, forcing the operation to stop.

The present invention has been made for the purpose of solving the above-mentioned problems.The conveyor frame 3 is raised and lowered by a lifting device M1 via a hoisting rope R, and tension is constantly applied to the hoisting rope R. This is controlled to prevent F<T.

That is, the load torque T applied to the drive device M of the bucket conveyor 5 is detected, and the lifting device M is proportionally controlled depending on the magnitude of the load torque T to raise and lower the conveyor frame 3. ), the torque is inversely proportional control, and when ascending (in the direction of decreasing T), the torque is directly proportional. Therefore, when descending, when the load torque T becomes small, it descends quickly, and as T increases, the descending speed decreases. reduce
In addition, when ascending, the larger the load I/Lux T, the more quickly it ascends to avoid overload, and the operation is always carried out under F-T2O conditions, that is, with tension being applied to the hoisting rope R of 9. It will be done.

[Example] The operation of configuration 1 of the present invention is as described above, and an example thereof will be explained with reference to FIGS. 3 and 4.

As shown in FIG. 3, the drive device M for the bucket conveyor 5 is composed of a deceleration motor Ma with a built-in load cell Mb and an amplifier Me. Amplify and send electrical signal (DC 4 to 20m) to controller C
It is supposed to be sent to

The lifting device M of the conveyor frame 3 is a hoisting drum Ml.
It consists of a, deceleration motors M and b, and an inverter MIC, and the inverter MIC is controlled by a signal from a controller C.

The controller 1-roller C receives an electric signal from the drive device M, sends a control signal to the inverter Mac according to preset conditions, controls the deceleration motors M and b by the inverter, and drives the hoisting drum 5Mla steplessly. It is designed to be controlled proportionally. Further, the above condition setting values can be arbitrarily set in the controller C.

In the figure, S is a sequencer, T is a torque limiter of the drive device M, LsL and sH are lower and upper limit switches of the lifting device M1.

To explain the specific operation method using the diagram shown in Figure 4, first select the operation mode to automatic, and after confirming that each operating condition and each device are normal, a ready signal is sent, and an automatic start command is issued. By packet code
・Bear drive device M and conveyor frame lifting device M1
starts.

A numerical example is shown below. Since there is no load at the beginning of the operation, the lifting device M0 lowers the conveyor frame 3 at the maximum speed, but the load cell Mb built in the deceleration motor Ma of the driving device M When the detected load torque T of the bucket conveyor reaches 20% of the rated torque of the deceleration motor Ma, the descending speed is reduced by inverse torque proportional control, and when the load 1 herk reaches 40% or more, the lifting device M1 stops and moves to that position. Sand raking work will be carried out.

When the load torque is between 40% and 60% of the rated torque, the lifting device M1 stops, and the conveyor frame 3 maintains its position.
The bucket conveyor 5 is driven by the drive device M with an appropriate load, and the sand raking work is performed, but due to an increase in the amount of sand flowing into the pond, the load torque detected by the load cell Mb increases to 60% or more. When this occurs, the signal is sent to the lifting device M1, and the lifting device M1 switches to the upper position 4, and the rising speed is given by torque direct proportional control.

As a result, when the detected torque of the load cell Mb becomes 40% or less, the lifting device M starts descending again, and the descending speed is given by I-lux inverse proportional control. When the conveyor frame 3 reaches the lower limit position, the limit switch LsL of the lifting device M1 is activated to stop the hoisting drum Mla, and the conveyor frame 3 is moved while the tension is applied to the hoisting rope R. The raking operation is performed while maintaining the lower limit position.

When the work is completed, the lifting device M is automatically switched to the lifting side and the conveyor frame 3 is pulled up. Needless to say, when the upper limit position is reached, the bucket conveyor 5 also stops when the lever I-switch Ls [I operates and stops.

[Effects] According to the present invention, the upper ends of the links 2a, 2b of equal length are pivoted to the support shafts 1a, 1b provided in parallel to each other on the upstream and downstream sides of the settling basin, respectively, and the links 2a, The front and rear ends of the conveyor frame 3 are pivoted to the lower end of the conveyor frame 2b to form a four-section parallelogram link, and each link node of the four-section parallelogram link has a bar-socket conveyor guiding sprocket 4a,
4b, 4c, and 4d, and drive unit N installed on the ground.
1. Drive the bucket conveyor 5 by the blade. , lifting device M.

When operating the anti-siltation type sand scraper in which the conveyor frame 3 is movable up and down via the hoisting rope R, the load torque applied to the drive device M is detected and the lifting device WM1 is proportionally controlled based on the magnitude of the load torque. The conveyor frame 3 is raised and lowered via the hoisting rope R, and its raising and lowering speed is controlled inversely proportional to the load torque when descending and directly proportionally when ascending, and tension is constantly applied to the hoisting rope R. Since the conveyor flrays 1 and 3 are operated at a suitable operating height depending on the amount of sediment, the raking work can be carried out with an appropriate load. Moreover, it is possible to shorten the idle running time at the start of operation and quickly resume normal operation, and when an overload is detected, the conveyor frame
The conveyor frame 3 can be raised quickly, and since the operation is carried out in a state in which tension is always applied to the hoisting loaf R, in other words, the operation is carried out under the condition of F≧T, so that the conveyor frame 3 There is absolutely no possibility that the packets will back up or that the packets will become stuck in the sand, leading to a stoppage of operation, which has the effect of solving all of the above-mentioned problems.

In addition, at each link node (rotation center) of the four-bar parallelogram link constituted by the links 2a and 2b and the conveyor frame 3, a baguette conveyor guiding subrocket t-4a is installed.
4 b, 4 c, 4 +" were arranged, so
Even if the conveyor frame 3 is raised and lowered as described above, the total length of the baguette conveyor 5 does not change.

There is also the additional effect that smooth driving control is possible.

[Brief explanation of drawings]

Fig. 1 is a side view of a bucket conveyor sand scraper with anti-siltation type, Fig. 2 is an explanatory diagram of the force relationship acting on the conveyor frame, Fig. 3 is an explanatory diagram of the operating circuit of the embodiment, and Fig. 4 is an explanatory diagram of the force relationship acting on the conveyor frame. It is an explanatory view showing an operation diagram of an example. la, Ib...support shafts 2a, 2b...link 3...conveyor frames 3a, 3b...front and rear shaft attachment parts 4a to 4d of 3...sprocket l-wheel 5...bucket 1 to conveyor M...Drive device Ma of 5...Deceleration motor Mb...Load cell Me...Amplifier Ml...Elevating device Mla of 3...Hoisting drum M, b...Deceleration motor Mac...・Inverter R...Hoisting rope

Claims (1)

[Claims] The upper ends of links 2a and 2b of equal length are respectively attached to support shafts 1a and 1b provided parallel to each other on the upstream and downstream sides of the settling basin, and the front and rear ends of the conveyor frame 3 are attached to the lower ends of the links 2a and 2b. The ends are pivoted to form a four-section parallelogram link, and bucket conveyor guide sprockets 4a, 4b, 4c, and 4d are arranged at each link node of the four-section parallelogram link, and the drive is installed on the ground. In an anti-siltation sand scraper in which a bucket conveyor 5 is driven by a device M, and a conveyor frame 3 can be raised and lowered by a lifting device M_1 via a hoisting rope R, the load torque applied to the drive device M is detected and the load torque applied to the drive device M is detected. The lifting device M_1 is controlled proportionally depending on the size, and the conveyor frame 3 is raised and lowered via the hoisting rope R.
The sedimentation prevention sand raking device is characterized in that its lifting speed is controlled in inverse proportion to the load torque when descending and directly proportional to the load torque when ascending, and is operated with tension applied to the hoisting rope R at all times. Machine operation control method