JP2004008926A - Apparatus for detecting breaking of chain in sludge scraping-up machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chain breaking detection apparatus which can prevent tooth skipping of a chain and can quickly detect the breaking of the chain. <P>SOLUTION: A connecting material 20 is disposed in a part for connecting a scraping-up plate 5 to a circumference chain 4. A chain guide 24 is installed for pushing the circumference chain 4 against a sproket 6 side by taking advantage of this gap. The position of the chain guide 24, when the circumference chain 4 has been broken, is displaced toward the sproket 6 side. At that time, the breaking of the circumference chain 4 is detected by detecting the position of the chain guide 24. Therefore, the tooth skipping of the circumference chain 4 can be prevented without hindering the passage of the scraping-up plate 5 upon the drive of the chain, and, at the same time, the breaking of the chain can be detected. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a chain break detection device for a sludge scraper used in a sewage treatment plant or a water purification plant, and particularly to a chain break detection device suitable for a sludge scraper using a plastic chain.
[0002]
[Prior art]
In general, in a sewage treatment plant or a water purification plant, inflow water mixed with sludge is once introduced into a sedimentation tank, and mud soil and earth and sand contained in the inflow water are settled and separated. The settled sludge is collected in a sludge pit provided on one side of the bottom of the settling tank by a sludge scraper installed at the bottom of the settling tank, and then discharged out of the settling tank.
[0003]
The sludge scraper scrapes sludge by moving a plurality of scrapers in one direction. That is, on both sides facing the sedimentation tank, circling chains are arranged, and both ends of the scraping plate are attached to two chains, and by driving this chain, the scraping plate is moved along the bottom of the precipitation tank. , And the settled sludge is raked and sent to the sludge pit. The sludge raked into the sludge pit is periodically discharged by a pump. In addition, the scraping plate that has scraped the sludge is guided by a chain orbiting the side surface and turns upward, and moves in the direction opposite to the direction in which the sludge is scraped, and moves on the surface of the sedimentation tank.
[0004]
It is known that the constituent members of such a sludge scraper are formed of a plastic material to reduce weight and improve corrosion resistance. In this method, the scraping plate, the chain, and the sprocket are made of plastic, and the driving force is reduced by reducing the weight, and the corrosion resistance is improved.
[0005]
[Problems to be solved by the invention]
However, chains and scraping plates made of plastic are light in weight, so that buoyancy is generated in water, and the chains and floats easily float when moving near the surface of the sedimentation tank and easily come off the sprocket. In particular, on the output side of the chain where the load on the drive sprocket portion of the chain is small, the chain is disengaged from the range where the chain and the sprocket are wound, and tooth jumping is likely to occur. When such tooth skipping occurs, the scraping plate guided by the two chains is in a state of skew in the traveling direction. If the rake plate slides in a skewed state, the load applied to the chains arranged on both side surfaces of the rake plate is not uniform, and eventually the chain is broken. If the chain breaks, the device will be damaged, so it is necessary to detect this early and repair it.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a chain breakage detecting device of a sludge scraper capable of preventing chain skipping and detecting chain breakage.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a chain breakage detecting device for a sludge scraper according to the present invention prevents tooth jump of the chain on the entrance side or the exit side of a sprocket around which a chain for winding around a scraper plate is wound. A chain guide is provided so that the chain guide is displaced from the guide position when the chain breaks, and a chain break can be detected by detecting a change in the position.
[0007]
Further, a chain guide for preventing tooth jump of the chain at an entrance side or an exit side of a sprocket around which a chain for winding around the scraping plate is provided, and an urging means for urging a side surface of the chain to resiliently are provided. The position of the urging means may be displaced when the chain breaks, and the change in the position may be detected to detect the breakage of the chain.
It should be noted that, when the scraping plate is attached to the chain, a structure in which the connecting member is interposed to connect the scraping plate is very effective when installing a tooth jump prevention chain guide.
[0008]
[Action]
According to the above configuration, when the chain is broken, the position of the chain guide or the urging means for preventing tooth jump is displaced, and the chain break can be detected by detecting the change in the position.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, specific embodiments of a chain breakage detecting device for a sludge scraper according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an arrangement of a sludge scraper in a settling tank, FIG. 2 is an explanatory view of an engagement state of a sprocket and a chain according to the present invention, and FIG. 3 is an explanatory view of a chain breaking device according to the present embodiment. (1) is a perspective view, and (2) is a front view.
[0010]
In a water treatment facility such as a sewage treatment plant or a water purification plant, sewage is introduced into a sedimentation tank 1 where it is separated into sludge and water. Sludge contained in the sewage settles at the bottom of the settling tank 1 and is collected in the sludge pit 3 by the sludge scraper 2 arranged inside the settling tank 1.
[0011]
As shown in FIG. 1, the sludge scraper 2 is provided with a circling chain 4 on both sides facing the sedimentation tank 1, and a plurality of rake plates 5 are bridged between the two circling chains 4. . A driving force is applied to the orbiting chain 4 via a sprocket 6. The orbiting chain 4 moves the bottom of the sedimentation tank 1 in a direction toward the sludge pit 3 and then turns upward, moves near the water surface of the sedimentation tank 1 in a direction opposite to the traveling direction of the bottom, and moves inside the sedimentation tank 1. Orbit. Therefore, the scraping plate 5 slides on the bottom of the sedimentation tank 1 to scrape the sludge at the bottom and accumulate in the sludge pit 3, and thereafter, is guided upward by the orbiting chain 4 and orbits upward. The scum generated near the surface of the water is raked and a cycle of returning to the bottom is performed.
[0012]
As shown in FIG. 2, the sprockets 6 are arranged in parallel so that two disks 10 face each other, and the centers of these disks 10 are connected to each other by a boss 7 serving as a central axis. A plurality of mounting holes 12 are provided at an equal pitch on the outer periphery of the disk 10, and a feed pin 14 is attached to each of the mounting holes 12 so as to be mounted thereon. That is, a portion corresponding to a tooth of the sprocket 6 is formed by the feed pin 14. Such sprockets 6 are provided at four places in the front and rear and up and down of the sedimentation tank 1, and as a set, one set is arranged on each of the right and left sides, and a total of eight places are provided. One sprocket 6A is a driving sprocket among the sprockets around which the one orbiting chain 4 is wound. A driving shaft 8 is inserted into the center shaft of the sprocket 6A.
[0013]
The mounting hole 12 of the sprocket 6 is formed by piercing a set of spare mounting holes 12A and 12B on the outer periphery of the disk 10 so that when the mounting hole 12 is broken by a load applied to the feed pin 14, By changing the mounting position of 14, the disk 10 can be reused. In the present embodiment, such a sprocket 6 is formed of a plastic material. This makes it possible to provide a sprocket 6 which is lighter than steel and has excellent corrosion resistance.
[0014]
The circling chain 4 has a configuration in which a plurality of segments 18 are connected endlessly. The segment 18 has a substantially L-shaped engaging step portion 16 that engages with the feed pin 14 of the sprocket 6, and a connecting portion 19 that connects the segments with pins is provided at both ends in the longitudinal direction. ing. The height of the engaging step 16 is substantially equal to the outer radius of the feed pin 14. The engaging step 16 is formed over the entire width of the segment 18, and the width of the segment 18 is formed to be equal to or slightly shorter than the length of the feed pin 14. The length of the segments 18 in the longitudinal direction is such that when the segments 18 are connected to each other, the mutual distance between the engaging steps 16 is equal to the pitch interval between the feed pins 14 of the sprocket 6. Such a segment 18 is formed of a plastic material.
[0015]
A plurality of scraping plates 5 for scraping the sludge of the sedimentation tank 1 are attached to the orbiting chain 4 at equal intervals. The scraping plate 5 is made of a plastic material, and has a substantially U-shaped cross section having a length substantially equal to the cross section of the bottom of the settling tank 1. As shown in FIG. 3 (2), the scraping plate 5 is attached to the circling chain 4 via the connecting member 20. As the connecting member 20, a prism having a side length of about 1/3 of the chain width is used. Thus, by attaching the connecting member 20 between the orbiting chain 4 and the scraping plate 5, a gap is formed between the two, and this gap can be utilized when installing a chain guide described later. It becomes. In addition, a column can be used as the connecting member 20.
[0016]
By the way, the above-mentioned orbiting chain 4, sprocket 6, and scraping plate 5 are made of plastic material, so they are lightweight and have excellent corrosion resistance. However, when these members are arranged in water, buoyancy is generated. It becomes easier to float. In particular, in the drive sprocket 6A that is disposed above the sedimentation tank 1 and turns the vertically rising circular chain 4 in the horizontal direction, the load applied to the chain 4 is sharply increased on the output side where the circular chain 4 is wound. In order to reduce this, it is conceivable that the orbiting chain 4 floats up from the area where the sprocket 6A is wound, and the engagement between the orbiting chain 4 and the sprocket 6A is disengaged and tooth jump occurs. Therefore, in the present embodiment, a chain breakage detecting device 22 capable of preventing tooth jump of the orbiting chain 4 and detecting when the orbiting chain 4 is broken with respect to the sprocket 6 </ b> A provided on the upper part of the sedimentation tank 1. Is provided. The chain breakage detecting device 22 is attached to the exit side (upper part) of the upper sprocket 6A of the sedimentation tank 1 where the orbiting chain 4 is easily disengaged by buoyancy as described above.
[0017]
The chain breakage detecting device 22 presses the orbiting chain 4 toward the center of the sprocket 6 (in this case, from the top to the bottom) so that the orbiting chain 4 is tightly engaged with the area where the sprocket 6 is wound. And a detecting means for detecting breakage of the orbiting chain 4.
[0018]
The chain guide 24 has rollers 32 that can be in rolling contact with both side surfaces of the orbiting chain 4, and the rollers 32 are elastically urged by springs to press the orbiting chain 4 toward the sprocket 6. .
[0019]
Specifically, cylindrical rollers 32 are arranged at both left and right ends in the width direction of the orbiting chain 4 so as to be in line contact with each other. The roller 32 is formed to have a small diameter so as not to hinder the movement of the scraping plate 5 at least on the chain 4 side, and can be inserted into the gap between the orbiting chain 4 and the scraping plate 5. In addition, the length of the roller 32 is set to such an extent that the roller 32 can make line contact with the circling chain 4 without interfering with the connecting member 20. The roller 32 is attached to a post 34 in a cantilever manner via a bearing (not shown) so as to be freely rotatable.
[0020]
The post 34 is formed in a column shape and has a height at least equal to or greater than the thickness of the orbiting chain 4. The posts 34 to which the left and right rollers 32 are respectively attached are attached to a single support plate 36 arranged in parallel with the back surface of the orbiting chain 4. In addition, a guide member 38 having a T-shaped cross section is provided on the bottom surface of the support plate 36 so as to move in a direction perpendicular to the surface of the orbiting chain 4. The guide member 38 is for regulating the movement of the roller 32 so that the roller 32 is kept parallel to the orbiting chain 4 and properly contacts the chain 4.
[0021]
A guide support frame 40 is provided outside the chain guide 24. The guide support frame 40 has a structure in which the support plate 36 is housed inside, and the two side plates 42 are connected to the bottom plate 44 such that the L-shaped protrusions of the substantially L-shaped side plates 42 face upward and the inner surfaces thereof face each other. And the support plate 36 is arranged inside the side plates 42. That is, the upper surface of the L-shaped convex portion of the side plate 42 and the support plate 36 are arranged in parallel. A through hole 45 is formed in the bottom plate 44 so that the guide member 38 can reciprocate in the vertical direction. The guide member 38 is inserted into the through hole 45. This allows the chain guide 24 to move vertically inside the guide support frame 40.
[0022]
A spring 28 is provided to urge the chain guide 24 downwardly from above to generate a force in a direction opposite to the force of the orbiting chain 4 separating from the sprocket 6. The spring 28 uses a compression coil spring, and is disposed between the inner surface of the L-shaped protrusion of the side plate 42 and the support plate 36 of the chain guide 24. As a result, a force that urges the entire chain guide 24 downward is generated, and the orbiting chain 4 can be pressed and closely contacted with the sprocket 6 by the roller 32.
[0023]
In the present embodiment, the support plate 36 is elastically urged downward by using a compression spring. However, the lower portion of the support plate 36 and the upper surface of the bottom plate 44 of the guide support frame 40 are connected by a tension spring, and A biasing force may be applied in the direction. It is also possible to adopt a configuration in which the orbiting chain 4 is pressed by an actuator other than a spring.
[0024]
The chain guide 24 detects when the orbiting chain 4 is broken. As shown in FIG. 4B, a proximity sensor 50 is provided below the side plate 42 in the guide support frame 40 of the chain guide 24 as detection means. Further, a detection plate 52 is provided on a side portion of the support plate 36 so as to correspond to the proximity sensor 50. The proximity sensor 50 transmits a signal to a control unit (not shown) when an object is within a range of the sensor. The control unit is provided with a mechanism for notifying that there is an object near the proximity sensor 50, such as sounding an alarm or turning on a warning light.
[0025]
FIG. 4A shows a case where the orbiting chain 4 is broken within the range where the sprocket 6 is wound. In the normal state, tension is generated in the orbiting chain 4, while the chain guide 24 urges the orbiting chain 4 toward the sprocket 6. At this time, if the orbiting chain 4 breaks, the broken end of the orbiting chain 4 comes out of the area below the roller 32, and the chain guide 24 becomes free. Thus, the chain guide 24 falls to the bottom of the guide support frame 40. Due to this position change, the detection plate 52 approaches the proximity sensor 50, and the proximity sensor 50 detects this and sends a signal to the control unit.
[0026]
At this time, a program for controlling the drive of the sprocket 6 of the sludge scraper 2 is provided in the control unit, and the drive of the sprocket 6 is automatically stopped when the breakage of the orbiting chain 4 is detected by the proximity sensor 50. It is preferable to have a configuration. Thereby, when the orbiting chain 4 is broken, the sludge scraper 2 can be immediately stopped, and a load is applied to the orbiting chain 4 that has broken, the other orbiting chain 4, or individual sprockets 6. It is possible to prevent further damage from spreading.
[0027]
As described above, the chain break detecting device 22 of the sludge scraper 2 according to the present embodiment can press the orbiting chain 4 by the chain guide 24 and prevent tooth jump. Further, a break in the orbiting chain 4 is detected by detecting a change in the position of the chain guide 24 when the orbiting chain 4 is broken. Therefore, tooth jump prevention and fracture detection can be realized in one configuration.
[0028]
FIG. 5 is a sectional view of a main part showing another embodiment of the present invention. In FIG. 5, the rollers 62 projecting from the box frame-shaped support member 60 regulate the floating of the orbiting chain 4 in the same manner as in the above-described embodiment, thereby preventing tooth jump of the orbiting chain at the sprocket portion. In addition, a roller 64 that contacts the side surface of the orbiting chain 4 is disposed, and a biasing means is provided by a spring 68 that presses the roller 64 in a horizontal direction via an arm 66. A detection plate 70 is provided on the spring 68 side of the arm 66 having a T-shaped cross section. It is also assumed that a proximity sensor 72 is provided at a position where the detection plate 70 has moved when the spring 68 has expanded, and this signal is sent to the control unit. Accordingly, when the orbiting chain 4 is broken and goes out of the control range of the detection device, the arm 66 is pushed in the horizontal direction by the spring 68, and the detection plate 70 approaches the proximity sensor 72. By informing the operator of this state by an alarm or the like by the control unit, it is possible to determine that the orbiting chain 4 has been broken.
[0029]
In the above embodiments, the proximity sensor is used as a means for detecting a change in the position of the chain guide 24 or the urging means. However, the present invention is not limited to this, and other means can be used. For example, an appropriate means such as a pressure sensor for detecting a change in elastic force of a spring or a position sensor for measuring a distance displacement of an object can be selected.
[0030]
【The invention's effect】
According to the present invention, the chain guide can prevent the chain from jumping at the sprocket. Further, when the chain is broken, the breaking of the chain can be promptly detected by detecting a change in the position of the chain guide itself or a change in the position of the biasing means for elastically biasing the side surface of the chain.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an arrangement of a sludge scraper and a chain breakage detection device in a sludge settling tank.
FIG. 2 is an explanatory view of an engagement state between a sprocket and a chain according to the present invention.
FIGS. 3A and 3B are explanatory diagrams of a chain breakage detecting device according to the embodiment, wherein FIG. 3A is a perspective view and FIG. 3B is a front view.
FIG. 4 is an explanatory diagram of chain break detection.
FIG. 5 is a sectional view of a main part of a modified example of the chain breakage detecting device according to the present invention.
[Explanation of symbols]
1 sedimentation tank, 2 sludge scraper, 3 sludge pit, 4 orbiting chain, 5 scraper plate, 6 sprocket, 7 boss, 8 ... Driving shaft, 9 ... Motor, 10 ... Disc, 12 ... Mounting hole, 14 ... Feed pin, 16 ... Engagement step, 18 ... Segment, 19 ... ... Connecting part, 20 connecting material, 22 chain breakage detecting device, 24 chain guide, 28, 68 spring, 32, 62, 64 roller 34 Post, 36 Support plate, 38 Guide material, 40 Guide support frame, 42 Side plate, 44 Bottom plate, 45 Through hole, 50, 72 Proximity Sensor, 52, 70... Detecting plate, 60... Support, 66.

Claims (2)

A chain guide is provided on the entry side or the exit side of the sprocket for winding the chain around the scraping plate to prevent the chain from jumping, so that the chain guide is displaced from the guide position when the chain is broken. A chain breakage detecting device for a sludge scraper, wherein a chain breakage can be detected by detecting a change in the position of the chain. A chain guide for preventing jumping of the chain teeth on the entry side or the exit side of the sprocket around which the chain for winding the rake plate is wound, and biasing means for biasing the side surface of the chain to resiliently press the chain; Wherein the position of the urging means is displaced when a break occurs, and a change in the position is detected to detect a chain break.

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