JP2005015182A - Chain abnormal condition detecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably and inexpensively provide a chain abnormal condition detecting device capable of preventing an accident by detecting that expansion of a chain reaches a predetermined amount and using that for maintenance, and promptly detecting the breakage of the chain. <P>SOLUTION: In the device for detecting an abnormal condition of the chain of a chain-flight type sludge collecting machine, a linear element 11 is arrange so as to intersect in a traveling direction under the chain 2. The linear element 11 is fixed to one pond side portion at a first end, and connected to a detecting portion 20 provided above a pond of the other pond side portion at a second end. The detecting portion 20 detects changes of the second end position of the linear element 11, thereby detecting the abnormal condition of the chain 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for detecting abnormalities such as excessive elongation and cutting of a chain used in a chain flight type sludge scraper.
[0002]
[Prior art]
In general, a chain flight type sludge scraping machine is used in a sedimentation basin or a sand basin of a sewage treatment plant to scrape the sedimented sludge into a sludge discharge groove. The chain flight type sludge scraper installs a driving sprocket and a driven sprocket in a pond, and stretches a pair of parallel chains with multiple flights between these sprockets in an endless manner, and moves this pond bottom. To collect the precipitate. Since the chain is subjected to a large tension, if it is operated for a long period of time, it will stretch and loosen, and it may detach from the sprocket or break. When these accidents occur, if the sludge scraper is stopped immediately and the chain is not replaced, the flight or sprocket will be damaged, and the sewage treatment facility will be unusable for a long time. For this reason, an apparatus for quickly detecting the occurrence of an abnormality such as elongation exceeding a predetermined amount of the chain or cutting is desired. For example, Japanese Patent Laid-Open No. 10-165715 (Patent Document 1) and Japanese Utility Model Laid-Open No. 56- No. 31807 (Patent Document 2).
[0003]
Patent Document 1 discloses an apparatus for detecting a breakage of a chain, and a breakage detection apparatus that can accurately detect a breakage of the chain and requires little adjustment work after being installed once. It is supposed to provide. That is, the detection device is a detection body in which a guide plate is attached to a flight surface so that a rod-like arm having a non-contact type metal detection sensor at one end and a guide plate covering the front surface of the detection device can swing around the other end. It is a configuration that is suspended so that it hits. As a result, during normal operation, the flight hits the guide plate and passes while swinging the rod-shaped arm, so the sensor outputs a detection signal each time. Since the board does not collide with the flight, the detection signal from the sensor is not output. Therefore, it is possible to detect whether or not the chain is cut by monitoring the output timing of the detection signal.
[0004]
Patent Document 2 discloses a detection device that can detect excessive slack or cutting of an endless chain of a sludge scraper. In other words, a lever is provided that can rotate about the horizontal axis and has one end that comes into contact with the endless chain from the inside of its moving path with buoyancy, etc., and one end of the wire rope is connected to the lever. The other end of is connected to a winding device on the pond. When elongation occurs in the endless chain, the endless chain is slackened, and one end of the lever is rotated downward by a distance corresponding to the degree of slackening. As a result, the wire rope moves downward, and by detecting this moving distance, it is possible to detect that the amount of slack exceeds the allowable range or that the chain has been cut.
[0005]
[Patent Document 1]
JP-A-10-165715 (paragraph numbers 0026 to 0029)
[Patent Document 2]
Japanese Utility Model Publication No. 56-31807 (2-3 pages)
[0006]
[Problems to be solved by the invention]
When the chain is cut, as described in Patent Document 1, it is important to quickly stop the sludge scraper. However, although the detection device of Patent Document 1 is said to have no restrictions on the installation location, depending on the relationship between the installation location and the chain cutting position, the flight does not always stop to the detection device. However, there is a possibility that a flight is sent for a while and a detection signal is output. For example, if the detector is installed in a place where the chain sent from the drive sprocket is supported by the return rail, and the chain is cut near the exit of the drive sprocket, the flight on the return rail will be Although it is in a state of being inclined in a plane, it moves on the rail as it is and hits the guide plate, so detection signals are output one after another and cutting cannot be detected immediately.
[0007]
By the way, the restoration process after the chain is cut is a large-scale work because the damaged member can be replaced only after the sludge water is removed from the pond. For this reason, even if a cut detection signal is suddenly output, it is necessary to confirm whether or not the information is correct. If this takes time, the entire sludge scraping machine will be damaged, which is difficult to deal with. . Accordingly, it is desirable that various warnings can be prepared if a warning is given in advance of danger before being cut off. However, Patent Document 1 cannot output such a warning.
[0008]
In this respect, since Patent Document 2 can continuously detect the slack of the chain, it can foresee the danger of excessive slack and cutting and replace it before an abnormal situation occurs. Can be prepared.
However, the detection device needs to be installed for each of a pair of parallel endless chains, and at least two sets of mechanical devices and control devices are necessary. Also, in terms of mechanical equipment, it is necessary to install a lever whose other end is supported by a bearing so that it can rotate around a horizontal axis so that one end of the lever contacts an endless chain from the inside of the moving path. There will be high equipment costs. Furthermore, one end of the lever wears because it always slides in the sludge in the sludge, and if this is left unattended, it will not be possible to detect slack in the chain for the amount of wear, so the lever must be replaced periodically. . Further, since the rotating portion of the lever has been immersed in sludge for a long time, there is a risk that the lever will be unable to rotate due to clogging or corrosion of the dirt, and there is a problem in detection reliability.
[0009]
Therefore, according to the present invention, it is possible to detect that the elongation of the chain has reached a predetermined amount and use it for subsequent maintenance and management to prevent an accident. An object of the present invention is to provide a chain anomaly detection device that can detect the problem quickly and reliably.
[0010]
[Means for Solving the Problems]
The present invention is an apparatus for detecting an abnormality of a chain of a chain flight type sludge scraper, in which a linear body is disposed so as to intersect the movement direction below the chain and one end is fixed to one pond side. Then, the other end is routed so as to be connected to the detection unit provided on the pond on the other pond side, and the detection of the chain abnormality is detected by detecting the change in the other end position of the linear body by the detection unit. It is said.
In the present invention, it is preferable that a portion of the linear body disposed at least below the chain so as to cross the moving direction is a polyvinylidene chloride synthetic fiber.
Further, the detection unit according to the present invention is configured such that the other end of the linear body is connected and the movable member to which a load that applies tension to the linear body is applied, and the position of the movable member when the linear body is cut. It is preferable to provide a switch for detection.
In the present invention, it is preferable that the chain extruded from the drive sprocket is disposed at a portion where the catenary is formed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The chain abnormality detection device (hereinafter abbreviated as a detection device) of the present invention will be described with reference to the drawings, taking as an example the case where it is detected that the chain has reached a predetermined amount.
FIG. 1 is a diagram in which a detection device 10 is installed in a chain flight type sludge scraper 1 in a sedimentation basin, FIG. 2 is a diagram showing an outline of the detection device 10 as viewed from the direction of arrow A in FIG. FIG. 4 is a diagram showing a state of the detection apparatus 10 when the chain is slack. The sludge scraper 1 shown in FIG. 1 has a configuration in which a pair of parallel endless chains 2 are wound around a drive sprocket 3 and driven sprockets 4a and 4b. 5 is attached. The chain 2 receives the torque of the drive sprocket 3 and moves in the direction of the arrow. Between the driven sprockets 4 a and 4 b, the flight 5 is guided by the support rail 6 (shown in FIG. 2) and moves along the bottom of the pond, and the deposits are collected in the discharge groove 7. Between the driving sprocket 3 and the driven sprocket 4a, the flight 5 is supported by the return rail 8 and moves. The detection device 10 is arranged in a catenary part c that exhibits a suspended state while the chain 2 is separated from the drive sprocket 3 and supported by the return rail 8. The catenary part c is a place where the chain 2 is slackened or stagnated first, no matter where the chain 2 breaks.
[0012]
As shown in FIG. 2, the detection apparatus 10 attaches one end of a synthetic fiber linear body 11 to a fixture 12 on one side wall side of the pond, and a pair of parallels of the catenary part c through a sheave 13a. The other end of the chain 2 is routed so as to be substantially orthogonal to the moving direction, and the other end is connected to the detection unit 20 installed on the pond via a sheave 13b provided on the opposite side wall surface side. The distance d between the linear body 11 traversing the pond and the lower chain below it is set based on the amount of slack at the arrangement position of the detection device 10 that occurs when the chain 2 extends by a predetermined amount. . In addition, since the chain elongation amount when the chain 2 is cut can obtain an appropriate value from the design surface or the actual surface, the predetermined elongation amount should be a value smaller than this cutting elongation amount as appropriate. Good. Further, the amount of slack can be calculated based on the structure of the sludge scraper 1 or can be obtained from the past operation results of the same kind of sludge scraper. Accordingly, the linear body 11 and the chain 2 are not in contact with each other at normal times.
[0013]
As shown in FIG. 3, the detection unit 20 presses the movable member 14 to which the other end of the linear body 11 is connected and the movable member 14, thereby applying a predetermined tension to the routed linear body 11. A spring 15, a switch 16 s for detecting the position of the movable member when the linear body 11 moves a predetermined amount against the spring force, and a switch 16 c for detecting the position of the movable member when the linear body is cut off are provided. ing. In FIG. 3, when the linear body 11 moves against the spring force, the switch 16s is shown on the right side because the movable member 14 moves to the right along the guide rod 17, and the linear body 11 is cut. In this case, since the movable member 14 moves to the left along the guide rod 17 by the spring force, the switch 16c is shown on the left side.
[0014]
Next, the detection operation will be described.
The chain 2 is not in contact with the linear body 11 as shown in FIG. 2 because the slack in the catenary part c is small when the elongation is normal. Therefore, since the force from the chain 2 does not act on the linear body 11, the position of the connected movable member 14 does not change. As the operation time elapses, the chain 2 extends and the chain slack of the catenary part c increases, so that the linear body 11 is pushed downward while being slid at the lower part of the chain 2 as shown in FIG. become. The behavior of the linear body 11 thereafter is not uniform, and the following cases mainly occur.
[0015]
1) When the linear body 11 is pushed down according to the slack of the chain 2.
Since the routing path of the linear body 11 is gradually increased, the movable member 14 to which the linear body 11 is connected slowly moves to the right in FIG. 3 against the spring force, Eventually the right switch 16s is turned on. The ON output of the switch 16s can be an alarm signal indicating that the extension of the chain 2 has exceeded a predetermined amount.
2) When the linear body 11 is caught by the chain 2 and pulled in the movement direction of the chain 2.
Since the routing path of the linear body 11 becomes longer in the same manner as described above, the movable member 14 of the detection unit to which the linear body 11 is connected resists the spring force and moves to the right in FIG. Compared with the case of 1), it moves in a very short time. If the linear body 11 is immediately caught, the movable member 14 returns to the original position immediately after moving a little, so the right switch 16s is not turned ON. When the catch of the linear body 11 is not released, the movable member 14 continues to move and turns on the right switch 16s. In this case, the elongation of the chain 2 is usually smaller than the elongation of the chain in the above case. As in the above, the ON output from the switch 16s is used as an alarm signal that the elongation of the chain 2 exceeds a predetermined amount. be able to.
[0016]
After that, when the linear body 11 is continuously pushed downward in the case of 1) above, or when the linear body 11 is continuously pulled in the case of 2), the movable member 14 further moves rightward and reaches the stopper 18. When the tension becomes higher than the tensile strength, the linear body 11 is cut. The linear body 11 may be cut by being slid by the chain 2 or may be cut by being pressed against the return rail 8 in the structure in which the return rail 8 extends toward the drive sprocket 3 as shown in FIG. There is also a case. When the linear body 11 is cut, the tension applied to the movable member 14 is lost, so that the left switch 16c is turned on by moving to the left in FIG. 3 by the spring force. In the case of 2), the linear body 11 may come off the sheave 13a or 13b. At this time, however, the handling path is shortened and the tension is lost. Moves to the left in FIG. 3 by the spring force and turns on the left switch 16c. Thus, the signal from the left switch 16c indicates that the linear body 11 has been cut or disconnected, and indicates that at least the linear body 11 has been moved greatly after contacting the chain 2. .
[0017]
As described above, when the chain 2 is extended by a predetermined amount or more, the right switch 16s is first turned on, and this can be used as an alarm signal. However, the flight 5 may swing up and down due to fluctuations in the water level or the like. The right switch 16s may be turned on even when the chain 2 has not yet extended to the predetermined amount. Therefore, if an alarm signal is generated by using the ON output of the right switch 16s, an alarm can be issued early, but there is a possibility of an erroneous output due to noise. Therefore, the alarm signal with higher accuracy can be obtained by using the ON output of the left switch 16c.
After the warning signal is issued, maintenance management should be performed so that the chain and sprocket are replaced before the chain is cut. It should be noted that the time from when the alarm signal is issued until the cutting can be predicted based on the set predetermined elongation amount, the time from the start of operation until the alarm signal is issued, the margin for cutting elongation, and the like.
[0018]
As described above, the detection device 10 of the present invention stretches the single linear body 11 in the sludge so as to cross the lower side of the pair of parallel chains 2 and intersect the moving direction thereof. However, since a structure having a mechanically movable part such as a bearing part is not used, the structure is extremely simple and the construction is easy, and the operation reliability is high even after a long time. The linear body 11 has a tensile strength that does not hinder the movement of the chain 2 when it is hooked on the chain 2, and it is preferable that the elongation is small so that the detection sensitivity becomes high. Moreover, since it is used in sludge water, the thing whose performance does not deteriorate for a long time under such an environment is used. That is, it has strong chemical resistance, hardly absorbs water, is hardly affected by mold and bacteria, has a smooth surface and is difficult to leave foreign matter, and is easy to leave. For example, it is a polyvinylidene chloride synthetic fiber having a diameter of 0.1 to 1 mm. An approximately circular cross-sectional shape with a tensile strength of (1-3) × 9.8 × 10 ⁻³ Newton / denier and a tensile elongation of 30% or less may be used. In addition, the linear body 11 should just be used for the part which contacts the chain 2 at least between sheaves 13a and 13b, even if it does not use the synthetic fiber type thing as mentioned above over the full length. Further, the spring force that acts on the movable member 14 of the detection unit 20 to apply tension to the linear body 11 may be appropriately set according to the tensile strength and elongation of the linear body 11 to be used.
[0019]
The case where one set of the detection device 10 is provided in the catenary part c has been described above, but two or more detection devices 10 are installed to output information for maintenance management in more detail, or the chain is disconnected. If this happens, this can be detected. For example, if two sets of the first detection device and the second detection device are installed, two kinds of intervals d between the chain 2 and the linear body 11 can be set, so that a two-stage alarm signal can be output. The first detection device can be used for alarm signal output, and the second detection device can be used for chain cutting detection.
[0020]
When the second detection device is used for chain cutting detection, the distance d between the chain 2 and the linear body 11 is set to a value larger than the alarm signal output value set as described above.
When the chain 2 is cut, the tension of the cut chain is released, so that the chain 2 is slack in the catenary part c wherever the cutting point is. Since the slack speed and the slack amount are much larger than those caused by normal chain elongation, the linear body 11 is cut off within the time until the flight is sent by one pitch after the chain is cut, and the left switch 16c. Becomes ON. The slack speed varies depending on where the chain 2 is cut. For example, when the chain 2 is cut at the catenary part c, the chain 2 is slackened so as to fall on the linear body 11, and the linear body 11 is cut at once. The left switch 16c is turned on immediately after the chain is cut. This is the same between the drive sprocket 3 and the driven sprocket 4b in which the chain 2 is not supported by the rail. If the detection device 10 is installed in this place, if the chain 2 is cut, it is detected immediately. it can.
[0021]
Normally, it is sufficient to receive an ON signal of the left switch 16c from the first detection device and use it as alarm information, and take a maintenance management system in which the chain is replaced at an appropriate time. If the left switch 16c of the second detection device is turned on, the sludge scraper is immediately stopped and repair work is performed even if the chain is cut off. If the right switch 16s is turned on before the left switch 16c of the second detection device is turned on, there is a possibility that it is not a cut but a slack. preferable. In addition, before the alarm information is issued from the first detection device, the chain may be disconnected due to some accident. In this case, the left switch 16c from the first detection device and the second detection device is disconnected. The ON output is issued without much delay. In any case, if a left switch ON output is output from the first detection device, a maintenance management system is adopted, and if a left switch ON output is output from the second detection device thereafter, a sludge scraper is immediately used. It is good to stop. This is the same even when a plurality of detection devices are installed in any place of the sludge scraper.
[0022]
【The invention's effect】
As described above, the abnormality detection device of the present invention has a simple configuration, can be manufactured at low cost, is easy to construct, has no moving parts in sludge water, and has high operational reliability. In addition, since it is possible to detect that the chain has reached a preset elongation, it is possible to prevent an accident caused by the chain elongation by replacing the chain and the sprocket at appropriate timing thereafter. In addition, by installing it at multiple locations on the sludge scraper, it is possible to output more detailed information for maintenance and management, and it is possible to immediately detect chain breaks. Can be prevented.
[Brief description of the drawings]
FIG. 1 is a diagram in which an apparatus for detecting an abnormality of a chain according to the present invention is installed in a sludge scraper in a sedimentation basin.
FIG. 2 is a diagram showing an outline of the detection device of the present invention as seen in the direction of arrow A in FIG.
FIG. 3 is a plan view showing a detection unit of the detection apparatus of the present invention.
FIG. 4 is a diagram showing a state of the detection device of the present invention when the chain is slackened.
[Explanation of symbols]
1 ... Sludge scraper, 2 ... Chain, 3 ... Drive sprocket,
4 ... driven sprocket, 5 ... flight, 8 ... return rail,
10 ... Chain abnormality detection device, 11 ... Linear body, 13 ... Sheave,
DESCRIPTION OF SYMBOLS 14 ... Movable member, 15 ... Spring, 16 ... Switch, 20 ... Detection part d ... Space | interval dimension of chain lower part and linear body

Claims (4)

In an apparatus for detecting an abnormality of a chain of a chain flight type sludge scraper, a linear body is disposed so as to intersect the movement direction below the chain, and one end is fixed to one pond side, and the other end Is connected to a detection unit provided on the pond on the other pond side, and an abnormality of the chain is detected by detecting a change in the other end position of the linear body by the detection unit. Anomaly detection device. 2. The chain abnormality detection device according to claim 1, wherein a portion of the linear body disposed at least below the chain so as to intersect the moving direction is a polyvinylidene chloride synthetic fiber. The detection unit includes a movable member to which the other end of the linear body is connected and a load that applies tension to the linear body is applied, and a switch that detects the position of the movable member when the linear body is broken. The chain abnormality detection device according to claim 1, further comprising a chain abnormality detection device. 4. The chain abnormality detection device according to claim 1, wherein the chain pushed out of the drive sprocket is arranged in a portion forming a catenary.

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