JPS6221282Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a sand settling basin in which a bucket conveyor stretched in a sand basin is engaged with a sprocket foil of a bucket conveyor frame placed in the bottom of the basin to scrape up the sand in the basin. This relates to a raking machine.

Conventionally, there are sand scrapers shown in Fig. 2 of Japanese Patent Application Laid-open No. 55-47108 and Figs. 5 and 8 of Japanese Patent Application Laid-Open No. 55-114311. According to these known techniques, it is described that when the bucket conveyor frame reaches the pond bottom, the bucket conveyor frame is suspended vertically by the links.

For this reason, when scooping up sediment accumulated on the bottom of the pond, the bucket conveyor frame simply swings sideways, and the sand cannot be scooped up, which will be described later.

In order to solve this problem, the applicant has devised a method of suspending the bucket conveyor frame using inclined links so that the conveyor frame swings when a load greater than a set load is applied to the bucket conveyor frame.

This method is more effective than the previously known method in that it scrapes up sand from the bottom of the pond.

However, this method has the disadvantage that a great deal of load is placed on the bucket conveyor frame when it is removed from the burial site.

In view of this, the present invention includes a hoisting device in which the bucket conveyor frame is raised and lowered by an Ikegami winch, and is lowered when the bucket conveyor is driven;
By suspending the bucket conveyor frame in a swingable manner using links tilted at a certain angle so that it moves upward when a load higher than the set load is applied to the bucket conveyor frame, the upper layer of accumulated dirt can be removed. This allows for smooth raking from the top to the bottom of the pond.

In the figure, 1 is a settling basin that is installed at a sewage treatment plant, etc., and allows rainwater, etc. to be introduced through street gutters, dark ditches, etc. Inside this settling basin 1, a large number of buckets B are placed in an endless chain at the required pitch. Stretch the bucket chain 2 for sand raking, which is attached with As detailed in Fig. 1, this bucket chain 2 has a bucket conveyor frame 3 of a required length arranged along the bottom of the basin and in the longitudinal direction of the settling basin, and the bucket conveyor frame 3 is placed at both front and rear ends of the basin. Submersible sprocket wheels 5a and 5b are rotatably provided on the parts via support shafts 3a and 3b, respectively. Further, a guide shaft 4a is provided above the pond, and a guide sprocket wheel 4 is provided on each guide shaft. Furthermore, a take-up shaft 7a and a drive shaft 8a are also provided,
Sprocket wheels 7 and 8 for take-up and drive are provided on each shaft, respectively, and the bucket chain 2 is meshed and stretched between the wheels 5a, 5b, 4, 7, and 8.

Further, one or more chain guides 3c are vertically provided between the sprocket wheels 5a and 5b at both ends of the bucket conveyor frame 3, and the roller portion of the bucket chain 2 is supported by the chain guides 3c. This chain guide 3c is provided at the lower end of a bracket protruding from the bucket conveyor frame, and the frame is suspended between the chain guides 3c and 3c and between the sprocket wheels 5a or 5b at both ends and the adjacent chain guide 3c. Or even if it is raised, bucket tochien 2
The amount of sagging due to its own weight, etc. is determined so that it is within the allowable range. Therefore, if the frame length is large, the number of chain guides will also be large.

Further, the lower ends of the front link 9 and rear link 10 are pivotally connected to the front and rear parts of the bucket conveyor frame 3, respectively, and the upper ends of the links 9 and 10 are connected to shafts 9a and 10a provided in the sand settling basin. When the bucket conveyor frame 3 is in the sediment scraping position, that is, along the pond bottom, the links 9 and 10 are pivoted so as to be swingable, and the links 9 and 10 are at an angle θ from the vertical position as shown in FIG.
Support it in a tilted position with only one side receded.

The drive shaft 8a is provided with a drive sprocket wheel 8 driven at a required speed by a drive device M,
This drives the bucket chain conveyor to scrape up the sand, but the driving speed can be made variable so that the scraping capacity can be adjusted.
A carry-out machine 11 is provided below between the drive sprocket wheel and the take-up sprocket wheel for discharging the scraped up sand by tilting a bucket and discharging it to the outside of the settling basin.
At this time, if necessary, a bucket cleaning nozzle may be provided.

A guide 12 is provided in a substantially horizontal direction above the guide sprocket wheel 4 provided on the guide shaft 4a, a take-up shaft 7a that slides on this guide 12 is provided, a take-up sprocket wheel 7 is provided on this take-up shaft, The shaft 7a is slid to prevent the bucket chain from sagging and to allow normal operation.

In addition, a hoisting device 6 such as a winch is installed on the upper part of the rear end of the bucket conveyor frame 3.
One end of the wire rope W is fastened, and the bucket conveyor frame 3 is raised rearward and upward by the hoisting device 6.

In the above-mentioned sand scraper, when sediment, etc. flows into the sand settling basin and accumulates on the bottom of the basin above a certain level, the bucket conveyor frame, which has been stopped at the raised position, is moved by operating the hoisting device. It is lowered onto the sand, and the drive device M is driven. As a result, the bucket chain 2 is driven via the drive sprocket wheel 8, and each bucket B sequentially scrapes up the sediment from its upper layer.
The water is discharged to the outside of the pond via a conveyor (11).

Next, the relationship between the forward force of the bucket conveyor frame and the rake resistance force will be explained.

First, when the bucket conveyor frame is lowered to the upper layer of sediment using a hoist and the bucket conveyor is driven, the bucket conveyor frame descends while changing the relationship between its forward force and raking resistance force. The forward force F of the bucket conveyor frame is expressed by the weight of the conveyor frame 3 being W, and when the links 9 and 10 are in contact with and supported by the stoppers S, the links 9 and 10 are
If the angle θ formed by the angle θ is 10, it is expressed by the following equation. The tension of the bucket conveyor applied to the sprocket wheel 5a is T in the vertical direction and T in the horizontal direction from the sprocket wheel 5a, and the resultant force (raking resistance force) is
becomes T′. This resultant force T' acts as a resistance force during sand raking, and acts as a force that causes the bucket conveyor frame to retreat. When the relationship between this resultant force T' and the forward force F of the bucket conveyor frame is expressed by the following equation, that is, when F≧T', the bucket conveyor frame is descending. When F<T' and the lifting resistance of the bucket conveyor increases, the bucket conveyor frame moves upward and scrapes up the sand in the loaded area. Gradually reduce the load, and when F≧T', it will descend, and while repeating this process, it will descend at a slow speed and smoothly scrape up the sand.

Furthermore, the bucket conveyor frame reaches the bottom of the pond, which means that the links 9 and 10 are at an angle θ from the vertical position.
When the conveyor frame is abutted and supported by the stopper S in the retracted position, the relationship between the lifting resistance force T' and the forward force F' of the conveyor frame is expressed as F≧T'. In this case, even if the bucket conveyor is used to lift up the sediment, the bucket conveyor frame is held at the pond bottom position as shown by the solid line in FIG. Therefore, the bucket conveyor frame does not move back and the sand raking is performed normally until the raking amount reaches the set load.

In other words, compared to the known device in which the bucket conveyor frame is suspended vertically by links, which only sways horizontally and cannot scrape up water, the present invention is capable of raising water at the bottom of the pond under normal load, that is, within the set load. It is possible to smoothly scrape up a certain amount of sand. In addition, in contrast to systems that require a large load to escape from a bucket conveyor frame buried with dirty sand, the present invention constantly lowers the conveyor frame using a hoisting machine and scrapes up the dirty sand from the upper layer of the accumulated surface to the bottom of the pond. The sand can be raked up efficiently and smoothly without applying excessive force, and even when the amount of inflowing sediment increases, the sand can be raked up smoothly with a normal load.

The above-mentioned hoisting device is composed of an electric motor, an electromagnetic brake, and a limit switch, and after the operation is completed, the bucket conveyor frame is hoisted up by a manual push button switch or a timer. Then, at the start of operation, the limit switch LS1 is activated and the rope is lowered to the lower limit, and the bucket conveyor frame scrapes up the accumulated sand from the top. When the lifting is completed, the limit switch LS3 installed at one end of the link allows the conveyor to guide the conveyor. Work the frame lower limit,
Start motor hoisting. This is to operate the limit switch LS2 at the upper limit of hoisting to stop hoisting.

According to the present invention, when the bucket conveyor is stopped, the bucket conveyor frame is indexed and put on standby, and a hoist is provided that lowers when the bucket conveyor is driven, so that the bucket conveyor frame is not subjected to a load higher than the set load. Since the bucket conveyor frame is swingably suspended by links tilted at a certain angle so that it moves upwards, the conveyor frame moves from the upper layer of the sediment accumulation surface to the bottom of the pond while descending at a slow speed. It has the effect of ensuring smooth sand raking.

[Brief explanation of the drawing]

Figure 1 is a longitudinal front view, Figure 2 is a side view, Figure 3
4 and 5 are explanatory diagrams of the hoisting device. 1...Sand basin, 2...Bucket chain, 3a,
3b...Support shaft, 3c...Chain guide, 4a...
...Guide shaft, 4...Guide sprocket wheel, 5
a, 5b...Underwater sprocket wheel, 7...
Take-up sprocket wheel, 7a...
Take-up shaft, 8... Drive sprocket wheel, 8a... Drive shaft, 9... Front link, 10...
Rear link, 9a, 10a...shaft, 11...discharge machine, 12...guide, B...bucket, M...drive device, S...stopper.

Claims (1)

[Scope of utility model registration request] In a sand settling machine that scrapes up dirty sand in a settling basin by stretching a bucket conveyor over sprocket foils arranged on the upstream and downstream sides of a bucket conveyor frame, when the bucket conveyor stops, the bucket A hoisting device that indexes and waits the bucket conveyor frame and lowers it when the bucket conveyor is driven, and a hoisting device that tilts the bucket conveyor frame by a certain angle so that it moves upward when a load higher than the set load is applied to the bucket conveyor frame. A sand raking machine characterized by a bucket conveyor frame suspended swingably by set links.