JP2004028218A - Chain tooth skipping preventing means for sludge collecting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent tooth skipping of a chain and to grasp the possibility of the tooth skipping beforehand. <P>SOLUTION: A connecting material 20 is disposed in a connecting part between a collecting plate 5 and a circulating chain 4, and a chain guide 24 pushing the circulating chain 4 toward a sprocket side is installed using a clearance. A roller 32 is disposed in a part of the chain guide 24 in contact with the circulating chain 4 and operated following the operation of the circulating chain 4. A pushing position of the roller 32 can be adjusted by a screw 42. The circulating chain 4 is energized toward the sprocket surface by the roller 32 to prevent the tooth skipping of the circulating chain 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a chain tooth jump prevention device of a sludge scraper used in a sewage treatment plant or a water purification plant, and particularly to a chain tooth jump prevention device suitable for preventing and detecting tooth jump of a plastic chain. .
[0002]
[Prior art]
Generally, in a sewage treatment plant and a water purification plant, inflow water mixed with sludge is once introduced into a sedimentation tank, and sludge contained in the inflow water is 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 outside the settling tank for processing.
[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.
[0006]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a chain tooth skipping prevention device capable of preventing chain skipping and detecting the possibility of tooth skipping in advance.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a chain tooth skipping prevention device for a sludge scraper according to the present invention includes a chain that abuts the chain on the entry side or the exit side of a sprocket around which a chain for rotating a scraper plate is wound. A guide is provided, and the chain guide is characterized by comprising pressing means for pressing the chain against the sprocket surface, and position adjusting means for displacing the pressing position of the pressing means.
[0008]
The chain guide is provided with an urging means for urging the pressing means against the chain, and the pressing means is attached by the urging means so as to be displaceable from the pressing position, and by detecting the displacement of the position. It is good also as a structure which can detect the possibility of a chain tooth jump.
[0009]
The sprocket is formed of a plastic material, and a chain engaging roller is provided between the pair of side plates at a constant pitch on the same circumference. It is also possible to connect a plurality of segments each provided with an engagement step that engages with the engagement roller of the sprocket.
[0010]
[Action]
According to the above configuration, the chain is pressed against the sprocket surface by the pressing means provided on the chain guide, so that the chain can be brought into close contact with the sprocket. The pressing position of the pressing means can be displaced by the position adjusting means, so that the chain can be pressed at a favorable position when the chain is wound around the sprocket, thereby preventing the chain from jumping.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a specific embodiment of a chain tooth skipping prevention device for a sludge scraper according to the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view of a chain tooth jumping device according to the present embodiment, (1) is a perspective view, (2) is a front view, FIG. 2 is a schematic view showing an arrangement of a sludge scraper in a settling tank, FIG. 3 is an explanatory view of the engagement state between the sprocket and the chain according to the present invention.
[0012]
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.
[0013]
As shown in FIG. 2, 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.
[0014]
As shown in FIG. 3, the sprocket 6 is 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.
[0015]
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.
[0016]
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.
[0017]
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. 1 (2), the scraping plate 5 is attached to the orbiting 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. As described above, 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 the chain guide 24 described later is installed. It becomes possible. In addition, a column can be used as the connecting member 20.
[0018]
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 which is disposed above the sedimentation tank 1 and turns the vertically circulated chain 4 in the horizontal direction, the tension applied to the chain 4 is sharply increased on the output side where the circulated 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, the sprocket 6A provided in the upper part of the sedimentation tank 1 prevents the jumping of the orbiting chain 4 and detects the possibility that the orbiting chain 4 may jump. A chain tooth jump prevention device 22 is provided. The chain tooth jump prevention device 22 is attached to the exit side (upper part) of the sprocket 6A above the sedimentation tank 1 where the orbiting chain 4 is easily disengaged by buoyancy as described above.
[0019]
As shown in FIG. 1, the chain tooth skipping prevention device 22 moves the orbiting chain 4 toward the center of the sprocket 6 (in this case, from the top) so that the orbiting chain 4 is tightly engaged with the area around which the sprocket 6 is wound. A chain guide 24 is provided for pressing downward. The chain guide 24 includes a pressing means for pressing the chain to the pressing position, and a position adjusting means for displacing the mounting position of the chain guide 24. Since the pressing means comes into contact with the orbiting chain 4, it is preferable that the pressing means be configured to be able to follow the moving of the orbiting chain 4 without frictional resistance. Specifically, cylindrical rollers 32 as pressing means are respectively disposed on the left and right ends in the width direction of the orbiting chain 4 so as to make line contact. The roller 32 is formed to have a small diameter so as not to hinder the movement of the scraping plate 5 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. In FIG. 1B, the contact range of the roller 32 with the circling chain 4 is set to be about １ ／ of the width of the circulating chain 4. The roller 32 is attached to a roller holder 34 so as to be freely rotatable and supported at both ends. Therefore, the roller 32 can make rolling contact with the movement of the orbiting chain.
[0020]
The roller 32 is fixed to an adjusting frame 36, and the adjusting frame 36 is provided with a position adjusting unit that can displace the pressing position of the roller 32. Specifically, a through hole 38 is formed in the adjustment frame 36 formed of a plate material, and a nut 40 is fixed on the upper surface of the through hole 38. On the upper surface of the roller holder 34, a screw 42 formed to be screw-connectable with the nut 40 is attached. A flange 44 is provided at both ends of the screw 42, and the hook 44 provided on the upper surface of the roller holder 34 holds the flange 44. Thus, when the screw 42 is rotated, the roller holder 34 moves in parallel in the screw axis direction with the movement of the screw 42, and the vertical position of the roller holder 34 can be adjusted with respect to the adjustment frame 36. Thus, by moving the roller holder 34 with the screw 42, the pressing position of the roller 32 can be displaced.
[0021]
It is preferable that the mounting position of the roller 32 be displaceable not only in the vertical pressing position but also in the feed direction and the width direction of the orbiting chain 4. Therefore, means for adjusting the position of the adjustment frame 36 in the three-dimensional direction is provided, and this is attached to a guide support 50 described later. Assuming that the feed direction of the orbiting chain 4 is X, the width direction is Y, and the up-down direction is Z, as shown in FIG. 1A, adjustment plates 48X, 48Y, 48Z are arranged on the respective surfaces of XYZ, Position adjustment can be performed using these adjustment plates. Although the position can be adjusted in the Z direction by the screw 42 and the adjustment frame 36 described above, the adjustment width can be widened by providing the adjustment plate 48Z.
[0022]
To adjust the position in each direction, when adjusting the position in the X direction (feeding direction position), the position of the adjusting plate 48 is adjusted within the range of the vertically elongated bolt hole 52 formed in the adjusting plate 48X, and the orbiting chain is adjusted. The adjusting plate 48X and the guide support 50 may be fixed by bolts 54 at a position where the sprocket 4 and the sprocket 6 are engaged in a favorable state. When adjusting the position in the Y direction, one end 57 of a screw 56 screwed to a female screw portion 55 provided on the adjustment frame 36 is rotatably connected by a hook 58 provided on the adjustment plate 48Y. ing. Therefore, by rotating the screw 56, the position of the adjustment frame 36 in the Y direction can be adjusted. Further, when adjusting the position in the Z direction, the height of the adjustment plate 48Y can be adjusted by fixing the bolt 54A at a favorable position of the vertically elongated bolt hole 52A drilled in the adjustment plate 48Z. Thus, even when the sprocket 6 and the orbiting chain 4 are replaced with different ones, it is possible to cope by sliding and re-fixing the adjusting plates 48X, 48Y, 48Z.
[0023]
The chain guide 24 having such a position adjusting mechanism is attached to a guide support 50 that protrudes from the side surface of the settling tank 1. One end of the guide support 50 is fixed to the side wall of the settling tank 1 in a cantilever state so as to be parallel to the drive shaft of the sprocket 6, and the other end is arranged on the exit side of the winding range of the orbiting chain 4. Attached to. In the present embodiment, the strength is ensured by forming the guide support 50 in a U-shape.
[0024]
With the above configuration, the chain guide 24 according to the first embodiment can displace the position of the roller 32 that presses the orbiting chain 4 by the position adjusting unit. By adjusting the position of the roller 32 in this manner, the orbiting chain 4 can be favorably engaged with the winding range of the sprocket 6. Therefore, since the force which tends to lift the orbiting chain 4 in the upward direction is suppressed by the roller 32, it does not come off from the engagement position with the sprocket 6 and tooth jump is prevented.
[0025]
FIG. 4 shows a detailed view of a main part of the chain guide and the position detecting means according to the second embodiment. The roller 32 and the roller holder 34 that press the orbiting chain 4 are configured in the same manner as in the first embodiment. A sliding shaft 62 attached to the upper surface of the roller holder 34 is inserted into a through hole 66 of a frame 64 formed of a plate material, and a spring 60 is inserted into the sliding shaft 62 projecting from the upper surface of the frame 64. At least a portion of the sliding shaft 62 protruding from the upper surface of the frame 64 is a screw portion, and a nut 68 is attached to the screw portion. By adjusting the position of the nut 68 up and down, the spring force of the spring 60 sandwiched between the nut 68 and the upper surface of the frame 64 changes, and the urging force for urging the roller 32 downward can be controlled. it can. Further, when the urging force of the spring 60 is changed, the vertical position of the roller 32 is displaced and can be translated.
[0026]
In addition, if it is necessary to replace the orbiting chain 4 or the sprocket 6 due to the size of the sludge scraper 2 or the difference in driving force, the mounting position of the roller 32 is adjusted so that one chain guide 24 can cope with the need. Preferably, it is adjustable in three dimensions. Such position adjustment becomes possible by providing the adjustment plates 48X, 48Y, 48Z movable in the XYZ directions as shown in the first embodiment.
[0027]
By the way, in the second embodiment, a displacement sensor 70 for detecting the vertical position of the circling chain 4 is provided as chain tooth jump detection means. That is, the displacement of the flange 72 provided at the upper end of the sliding shaft 62 is detected by the displacement sensor 70 disposed above the flange 72. The position of the upper surface of the flange 72 is constantly measured by the distance measuring laser of the displacement sensor 70, and the measured value is transmitted to the control unit 74, and it is determined whether or not the measured value falls within a preset range of the ascending limit of the flange. For example, as shown in FIG. 4B, when the distance from the displacement sensor 70 to the upper surface of the flange 72 when the sprocket 6 and the orbiting chain 4 are in a good engagement state is L, the ascending limit distance is When the flange 72 rises within this range, it is considered that there is a possibility that a chain tooth jump may occur.
In addition, it is set so that the alarm 76 sounds when there is a possibility of occurrence of chain tooth jump. Note that a configuration may be adopted in which a warning lamp is turned on instead of the alarm device 76.
[0028]
The operation of the chain tooth jump prevention device according to the second embodiment is as follows. The position of the rollers 32 of the chain guide 24 is adjusted so that the orbiting chain 4 is engaged with the area where the sprocket 6 is wound. The orbiting chain 4 is elastically urged by the rollers 32 so as to be in close contact with the sprocket 6, and a favorable engagement state is ensured. At this time, the position of the upper surface of the flange 72 of the slide shaft 62 provided on the chain guide 24 is measured by the displacement sensor 70, and the position where the possibility of occurrence of chain tooth jump is set and stored in the control unit 74. . During the operation of the sludge scraper 2, the position of the upper surface of the flange 72 of the sliding shaft 62 is constantly measured. Here, when the orbiting chain 4 is slightly lifted off the sprocket 6, the position of the flange upper surface is raised accordingly. When the position of the upper surface of the flange 72 rises to a preset distance, the alarm 76 operates to warn the operator. This allows the operator to detect in advance the occurrence of chain tooth skipping, and to cope with this to prevent chain tooth jumping.
[0029]
【The invention's effect】
According to the present invention, a chain guide is provided for bringing the orbiting chain into close contact with the sprocket and engaging with the winding range. The chain guide is configured to press the orbiting chain in the direction toward the center of the sprocket, and this chain guide suppresses the rising of the orbiting chain and prevents the occurrence of chain tooth jump. In addition, it is possible to detect the possibility of chain tooth jump by making the chain guide abut on the circling chain by the urging means and detecting the lifting of the circulating chain by the position detecting means. This makes it possible to take measures such as adjusting the position of the chain guide in advance, thereby preventing chain tooth jump.
[Brief description of the drawings]
FIG. 1 is an explanatory view of a chain tooth jump prevention device according to a first embodiment, (1) is a perspective view, and (2) is a front view.
FIG. 2 is a schematic view showing an arrangement of a sludge scraper and a chain tooth jump prevention device in a sludge settling tank.
FIG. 3 is an explanatory view of an engagement state between a sprocket and a chain according to the present invention.
FIG. 4 is a detailed view of a main part of a chain tooth jump prevention device according to a second embodiment.
[Explanation of symbols]
1 sedimentation tank, 2 sludge scraper, 3 sludge pit, 4 circulating 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 portion, 20... Connecting material, 22... Chain tooth jump prevention device, 24... Chain guide, 32... Roller, 34... Roller holder, 36. , 66 ... through-hole, 40, 68 ... nut, 42 ... screw, 44, 72 ... flange, 46 ... hook, 48 ... adjustment plate, 50 ... guide support , 52... Bolt hole, 54... Bolt, 55... Female screw part, 57. 2 ......... sliding shaft 64 ......... frame 70 ......... displacement sensor 74 ......... controller, 76 ......... alarm.

Claims (3)

A chain guide that contacts the chain is provided on the entry side or the exit side of the sprocket around which the chain for winding the rake plate is wound, and the chain guide presses the chain against the sprocket surface. A chain tooth jump prevention device for a sludge scraper, comprising a position adjusting means capable of displacing a holding position. The chain guide is provided with an urging means for urging the pressing means against the chain, and the pressing means is attached by the urging means so as to be displaceable from the pressing position, and by detecting the displacement of the position. The chain tooth jump prevention device for a sludge scraper according to claim 1, wherein the possibility of occurrence of chain tooth jump can be detected. The sprocket is formed of a plastic material, and a chain engaging roller is provided between the pair of side plates at a constant pitch on the same circumference. The chain is formed of a plastic material and the sprocket is formed of a plastic material. The chain tooth jump prevention device for a sludge scraper according to claim 1 or 2, wherein a plurality of segments provided with an engagement step portion that engages with the engagement roller are connected.

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