JP5996459B2 - Sludge scraper rail structure - Google Patents

Description

  The present invention relates to a rail structure of a sludge scraper that is installed in a sedimentation basin and scrapes the sludge deposited on the bottom of the sedimentation basin.

  In general, in a sedimentation basin that settles and separates sludge at a sewage treatment plant, a sludge scraping machine that collects the sludge deposited on the bottom of the sedimentation basin and collects it in a hopper is installed.

  FIG. 12 shows an example of a conventional sludge scraping machine, where 1 is a sedimentation basin, 2 is a sludge scraping machine that scrapes the sludge deposited on the bottom of the sedimentation tank 1, and 3 is a sludge scraping machine 2. A hopper recessed at the bottom of one end in the longitudinal direction of the sedimentation basin 1 to collect the sewed sludge.

  As shown in FIG. 12, the sludge scraper 2 has an endless shape so that it can be circulated and driven in the longitudinal direction in the sedimentation basin 1 and has a required interval in the width direction perpendicular to the longitudinal direction of the sedimentation basin 1. A pair of chains 4 is provided, and a flight 5 for scraping sludge in the settling basin 1 is attached so as to span between the pair of chains 4, and extends in the longitudinal direction at the bottom of the settling basin 1. Thus, the pond bottom rail 6 for guiding the sludge scraping traveling at the pond bottom of the flight 5 is laid, and the sludge scraping traveling is finished so as to extend in the longitudinal direction at the required position inside the sedimentation basin 1. The upper return rail 7 and the lower return rail 8 that guide the return travel of the flight 5 are laid.

  A fixed shaft 9 extending in the width direction of the sedimentation basin 1 is rotatably disposed in the vicinity of the edge of the hopper 3 recessed at the bottom on one end side in the longitudinal direction of the sedimentation basin 1 and fixed to the fixed shaft 9. A sprocket 10 is fitted, and a drive shaft 12 extending in the width direction of the settling basin 1 and rotated by a driving device 11 such as a motor is disposed near the water surface of the settling basin 1 above the fixed shaft 9. Then, a drive sprocket 13 is fitted to the drive shaft 12, and an intermediate shaft 14 extending in the width direction of the settling basin 1 is rotatably disposed at a position near the water surface in the longitudinal intermediate portion of the settling basin 1. An intermediate sprocket 15 is fitted to the intermediate shaft 14, and a take-up shaft 16 extending in the width direction of the sedimentation basin 1 is rotatably and settled at the bottom of the other end in the longitudinal direction of the sedimentation basin 1. Is slidable in the longitudinal direction of the A take-up sprocket 17 is fitted on the up-shaft 16, and the chain 4 is wound around the fixed sprocket 10, the drive sprocket 13, the intermediate sprocket 15 and the take-up sprocket 17 in sequence, and the take-up shaft 16 is moved as necessary. Then, the chain 4 is slid in the longitudinal direction of the sedimentation basin 1 and the tension of the chain 4 can be appropriately adjusted by utilizing the weight of the chain 4 between the intermediate sprocket 15 and the take-up sprocket 17.

  As shown in FIG. 13, the flight 5 is attached with a shoe 18 that slides on the pond bottom rail 6 during the sludge scraping traveling of the flight 5, and as shown in FIG. A return shoe 19 is sometimes attached which slides on the upper return rail 7 and the lower return rail 8.

  As shown in FIG. 13, the pond bottom rail 6 includes a lower flange portion 6a, a web portion 6b, and an upper flange portion 6c. The lower flange portion 6a and the web portion 6b are embedded in the bottom of the sedimentation basin 1. Thus, only the upper flange portion 6c protrudes from the bottom surface of the settling basin 1 and a sliding plate 6d is attached to the upper surface of the upper flange portion 6c. Further, as shown in FIG. 14, the upper return rail 7 and the lower return rail 8 are composed of lower flange portions 7a and 8a, web portions 7b and 8b, and upper flange portions 7c and 8c. The lower flange portions 7a and 8a are mounted on the rail brackets 21a and 21b projecting inward from both sides in the direction by tightening the fastening members 24 and 25 such as bolts and nuts via the fixtures 22 and 23. The sliding contact plates 7d and 8d are attached to the upper surfaces of the upper flange portions 7c and 8c.

  In the sludge scraper 2 shown in FIG. 12, when the drive sprocket 13 fitted to the drive shaft 12 is rotationally driven by the drive device 11, the flight 5 is moved along the pond bottom rail 6 via the shoe 18 by the chain 4. The sludge deposited on the bottom of the sedimentation basin 1 is scraped by the flight 5 and collected in the hopper 3.

  The flight 5 that has finished the sludge scraping travel passes through the fixed sprocket 10, rises, passes through the drive sprocket 13, and then reverses up and down, along the upper return rail 7 via the return shoe 19. Drive near the water surface.

  The flight 5 traveling in the vicinity of the water surface of the settling basin 1 along the upper return rail 7 via the return shoe 19 passes through the intermediate sprocket 15 and then moves so as to sink toward the bottom of the settling basin 1. The vehicle travels along the lower return rail 8 through the return shoe 19 from the bottom of the settling basin 1 by a required dimension.

  The flight 5 traveling above the bottom of the sedimentation basin 1 along the lower return rail 8 through the return shoe 19 by a required dimension passes through the take-up sprocket 17 and then is turned upside down again through the shoe 18. Along the pond bottom rail 6, the vehicle travels along the bottom of the settling basin 1, and the same operation is repeated thereafter.

  In addition, as what shows the general technical level relevant to the sludge scraper of the structure as shown in FIGS. 12-14, there exist patent document 1, 2, for example.

JP 2003-117310 A JP-A-8-281010

  However, the pond bottom rail 6, the upper return rail 7, and the lower return rail 8 in the conventional sludge scraper 2 are steel rails (for example, a rail having a weight per unit length of 12 kg / m), and are slidable. Since the contact plates 6d, 7d, and 8d are made of stainless steel, the overall weight is increased and the cost is increased, resulting in poor workability during construction.

  Further, the lower flange portions 7a and 8a of the upper return rail 7 and the lower return rail 8 must be fastened to the rail brackets 21a and 21b by fastening members 24 and 25 via fixtures 22 and 23 from both sides. However, it was difficult to align the site at the time of construction, leaving room for improvement.

  Furthermore, the shoe 18 and the return shoe 19 are made of synthetic resin, and when the shoe 18 and the return shoe 19 slide on the stainless steel sliding contact plates 6d, 7d, 8d, a certain amount of frictional resistance is obtained. Therefore, it has been desired to further reduce the frictional resistance to reduce the driving force.

  In addition, the sliding contact plates 6d, 7d, and 8d are attached by welding to the upper surface of the upper flange portions 6c, 7c, and 8c of the pond bottom rail 6, the upper return rail 7, and the lower return rail 8, respectively. It has been difficult to exchange 6d, 7d, and 8d.

  The present invention has been made in view of the above-mentioned conventional problems, and it is possible to improve the workability by facilitating alignment on site at the time of construction as well as greatly reducing the overall weight and cost. Also, the present invention is intended to provide a rail structure of a sludge scraper that can further reduce frictional resistance and driving force and can easily replace a sliding contact plate.

In the present invention, a plurality of sprockets are looped endlessly in a settling basin so as to be freely circulated and driven in the longitudinal direction, and are arranged at a required interval in a width direction perpendicular to the longitudinal direction of the settling basin. A pair of chains,
A flight attached to span the pair of chains and scraping sludge in the settling basin;
A pond bottom rail that is laid to extend in the longitudinal direction at the bottom of the settling basin and guides sludge scraping on the pond bottom of the flight;
A return rail that is laid to extend in the longitudinal direction of the settling basin and guides the return travel of the flight that has finished the sludge scraping travel;
A shoe attached to the flight and sliding on a pond bottom rail during the sludge scraping traveling of the flight;
In the rail structure of the sludge scraper equipped with the return shoe attached to the flight and sliding on the return rail when the flight returns,
The pond bottom rail and the return rail are made of a synthetic resin rail composed of a lower flange portion, a web portion and an upper flange portion, respectively.
The lower flange portion is formed with a T-shaped groove that opens in the bottom surface and extends in the rail longitudinal direction, and the upper flange portion has a reverse T-shaped groove that opens in the upper surface and extends in the rail longitudinal direction. Forming,
A rail fixing plate provided with a screw hole is inserted into a groove having a T-shaped cross section of the lower flange portion, and a rail bracket is fixedly passed through the rail fixing plate and screwed into the rail fixing bolt. , Attach the pond bottom rail and the return rail to the rail bracket,
In a state where a sliding contact plate fixing plate provided with a screw hole is inserted into a groove having a reverse T-shaped cross section of the upper flange portion, and a sliding contact plate made of synthetic resin is placed on the upper surface of the upper flange portion, The rail of the sludge scraper, wherein the sliding contact plate is attached to the upper surface of the upper flange portion by passing the sliding contact plate and screwing the sliding contact plate fixing bolt into the sliding contact plate fixing plate. It depends on the structure.

  In the rail structure of the sludge scraper, it is preferable that the pond bottom rail and the return rail are made of polyvinyl chloride, and the sliding contact plate is made of ultrahigh molecular weight polyethylene.

Further, in the rail structure of the sludge scraper, the first joint plate is brought into contact with one side surface of the web portion in the longitudinal joint portion of the pond bottom rail, and the longitudinal direction of the pond bottom rail A second joint plate provided with a screw hole is brought into contact with the other side surface of the web portion at the joining portion, and the joint screw is passed through the first joint plate and the web portion to the second joint plate. By screwing, fixing at the longitudinal joint of the pond bottom rail,
The first joint plate is brought into contact with one side surface of the web portion at the longitudinal joint portion of the return rail, and the screw hole is spanned to the other side surface of the web portion at the longitudinal joint portion of the return rail. Is fixed to the longitudinal joint of the return rail by screwing a joint screw into the second joint plate through the first joint plate and the web portion. It is preferable to do so.

  According to the rail structure of the sludge scraper of the present invention, the overall weight can be reduced and the cost can be reduced, and the workability can be improved by making it easy to align the site at the time of construction. The frictional resistance and the driving force can be further reduced, and an excellent effect that the sliding contact plate can be easily replaced can be obtained.

It is a front view which shows the pond bottom rail in the Example of the rail structure of the sludge scraper of this invention. It is an enlarged front view which shows the pond bottom rail in the Example of the rail structure of the sludge scraper of this invention, Comprising: It is the II section detail drawing of FIG. It is a front view which shows the upper return rail (lower return rail) in the Example of the rail structure of the sludge scraper of this invention. FIG. 4 is an enlarged front view showing the upper return rail (lower return rail) in the embodiment of the rail structure of the sludge scraper of the present invention, and is a detailed view of the IV part in FIG. 3. It is a perspective view which shows the attachment method with respect to the bracket of a rail in the Example of the rail structure of the sludge scraper of this invention, and the attachment method of the sliding contact board with respect to a rail. It is a perspective view which shows the fixing method in the longitudinal direction junction part of a rail in the Example of the rail structure of the sludge scraper of this invention. It is a single figure of the shoe in the Example of the rail structure of the sludge scraper of this invention, (a) is a front view of a shoe, (b) is a side view of a shoe. It is a single figure of the return shoe in the Example of the rail structure of the sludge scraper of this invention, (a) is a front view of a return shoe, (b) is a side view of a return shoe. It is a front view which shows the state which the leg part of the shoe got on the pond bottom rail in the Example of the rail structure of the sludge scraper of this invention. It is a front view which shows the state which the hook-shaped part of the leg part of a return shoe is hooked on a return rail in the Example of the rail structure of the sludge scraper of this invention. It is a front view which shows the state which the leg part of the return shoe got on the return rail in the Example of the rail structure of the sludge scraper of this invention. It is a whole outline side view showing an example of the conventional sludge scraping machine. It is a front view which shows the pond bottom rail in an example of the conventional sludge scraping machine. It is a front view which shows the upper return rail (lower return rail) in an example of the conventional sludge scraping machine.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIGS. 1-11 is an Example of the rail structure of the sludge scraping machine of this invention, Comprising: The part which attached | subjected the code | symbol same as FIGS. 12-14 in the figure represents the same thing, Basic Although the construction is the same as that of the conventional one shown in FIGS. 12 to 14, the feature of this embodiment is that, as shown in FIGS. 1 to 11, the pond bottom rail 6, the upper return rail 7, and the lower return rail. 8 is a rail made of synthetic resin (for example, made of polyvinyl chloride) composed of lower flange portions 6a, 7a, 8a, web portions 6b, 7b, 8b and upper flange portions 6c, 7c, 8c.

  In the case of the present embodiment, a groove 6e having a T-shaped cross section is formed in the lower flange portion 6a of the pond bottom rail 6 as shown in FIGS. The upper flange portion 6c is formed with an inverted T-shaped groove 6f that is open on the upper surface and extends in the rail longitudinal direction, and a screw hole is formed in the T-shaped groove 6e of the lower flange portion 6a. The rail fixing plate 30 provided with 30a is inserted and inserted into the rail fixing plate 30, and the rail fixing bolt 31 is screwed through the rail bracket 20 fixedly arranged. 6, and a sliding plate fixing plate 32 provided with a screw hole 32 a is fitted into the groove 6 f having a reverse T-shaped cross section of the upper flange portion 6 c, and is fitted to the upper surface of the upper flange portion 6 c. With the sliding contact plate 6d made of resin (for example, made of ultrahigh molecular weight polyethylene) placed, the sliding contact plate fixing bolt 32 is screwed into the sliding contact plate fixing plate 32 through the sliding contact plate 6d. Thus, the sliding contact plate 6d is attached to the upper surface of the upper flange portion 6c.

  Further, in the lower flange portions 7a and 8a of the upper return rail 7 and the lower return rail 8, as shown in FIG. 3, FIG. 4 and FIG. 7e and 8e are formed, and the upper flange portions 7c and 8c are formed with reverse T-shaped grooves 7f and 8f that are open on the upper surface and extend in the rail longitudinal direction, and the cross-sections of the lower flange portions 7a and 8a. A rail fixing plate 30 provided with a screw hole 30a is fitted into the T-shaped grooves 7e and 8e, and rail brackets 21a and 21b that are fixedly arranged are passed through the rail fixing plate 30 so as to penetrate the rail fixing bolt. 31 is screwed to attach the upper return rail 7 and the lower return rail 8 to the rail brackets 21a, 21b, and the upper flange portions 7c, 8c The sliding contact plate fixing plate 32 provided with screw holes 32a is fitted into the reverse surface T-shaped grooves 7f and 8f, and the upper flange portions 7c and 8c are made of synthetic resin (for example, ultrahigh molecular weight polyethylene). With the sliding contact plates 7d and 8d being mounted, the upper flanges are fixed by screwing the sliding contact plate fixing bolts 33 into the sliding contact plate fixing plates 32 through the sliding contact plates 7d and 8d. The sliding contact plates 7d and 8d are attached to the upper surfaces of the portions 7c and 8c.

  As shown in FIG. 5, the slidable contact plate fixing bolt 33 is a stainless steel countersunk bolt with a flat head and a flat top surface, and is formed in the through hole 34 of the slidable contact plates 6d, 7d, and 8d. Is subjected to counterbore processing so that the head of the sliding contact plate fixing bolt 33 does not protrude from the upper surface of the sliding contact plates 6d, 7d, 8d, and the head of the screwed sliding contact plate fixing bolt 33 is screwed. As shown in FIGS. 2 and 4, a circular pad 35 made of the same material as the sliding contact plates 6d, 7d, 8d is embedded on the upper surface side so that the upper surfaces of the sliding contact plates 6d, 7d, 8d become flat. is there.

  On the other hand, as shown in FIG. 2 and FIG. 6, the first joint plate 36 is brought into contact with the one side surface of the web portion 6 b at the longitudinal joint portion of the pond bottom rail 6, and the pond bottom rail 6 is A second joint plate 37 provided with a screw hole 37a is brought into contact with the other side surfaces of the web portions 6b, 7b, 8b in the longitudinal joint portion, and the first joint plate 36 and the web portions 6b, 7b, 8b is penetrated and the joint screw 38 is screwed into the second joint plate 37 to fix the pond bottom rail 6 at the longitudinal joint portion.

  Further, as shown in FIGS. 4 and 6, the first joint plate 36 is brought into contact with one side surface of the web portions 6b, 7b, 8b in the longitudinal direction joining portions of the upper return rail 7 and the lower return rail 8. In addition, the second joint plate 37 provided with screw holes 37a is brought into contact with the other side surfaces of the web portions 6b, 7b, 8b in the longitudinal direction joining portions of the upper return rail 7 and the lower return rail 8. By joining the first joint plate 36 and the web portions 6b, 7b, 8b and screwing a joint screw 38 into the second joint plate 37, the longitudinal joining portions of the upper return rail 7 and the lower return rail 8 are connected. Is fixed.

  Incidentally, as shown in FIG. 1, leg portions 18 b are protruded at both width ends of the sliding portion 18 a with respect to the upper surface of the pond bottom rail 6 of the shoe 18, and the leg portion 18 b of the flight 5 during the sludge scraping running of the flight 5 is provided. At the lower end, a taper portion 18c is formed which has a downward slope from the width center side of the shoe 18 toward the width end portion side, and the upper surface of the upper return rail 7 and the lower return rail 8 of the return shoe 19 as shown in FIG. Legs 19b project from both width ends of the sliding part 19a, and a hook-like part projects toward the width center side of the return shoe 19 at the lower end of the leg 19b when the flight 5 returns. In addition to forming 19d, a taper portion 19c is formed which has a downward slope from the width center side of the return shoe 19 toward the width end side.

  Further, the dimension W from the width center to the width end of the shoe 18 is set longer than the gap C between the width end of the flight 5 and the pond bottom side surface, as shown in FIG.

  On the other hand, the pond bottom rail 6 has a lower flange portion 6a and a web portion 6b embedded in the bottom portion of the sedimentation basin 1, and only the upper flange portion 6c projects from the bottom surface of the sedimentation basin 1. The height of 18 b is the maximum height in a range where the sliding portion 18 a of the shoe 18 is in contact with the pond bottom rail 6 and does not touch the bottom surface of the sedimentation basin 1.

  Further, as shown in FIG. 3, the upper return rail 7 and the lower return rail 8 are mounted on rail brackets 21a and 21b projecting inward from both sides in the width direction of the settling basin 1. The height of the leg 19b of the return shoe 19 is set higher than that of the shoe 18.

  As shown in FIGS. 7A and 7B, the shoe 18 has an L-shaped cross section and a bottom portion of a bent piece 18f having two mounting holes 18e formed in the standing wall portion. The sliding part 18a and the leg part 18b are formed.

  Further, as shown in FIGS. 8A and 8B, the return shoe 19 has an L-shaped cross section and a bottom portion of a bent piece 19f in which four mounting holes 19e are formed in the standing wall portion. The sliding part 19a and the leg part 19b are formed.

  Next, the operation of the above embodiment will be described.

  As described above, the pond bottom rail 6, the upper return rail 7, and the lower return rail 8 are made of synthetic resin comprising lower flange portions 6a, 7a, 8a, web portions 6b, 7b, 8b and upper flange portions 6c, 7c, 8c, respectively. Assuming that the rails are made of, for example, polyvinyl chloride, the pond bottom rail 6, the upper return rail 7 and the lower return rail 8 in the conventional sludge scraper 2 are made of steel rails (for example, the weight per unit length is Compared to the case of a rail of 12 kg / m), the weight can be reduced to about 1/6 and the workability at the time of construction is improved, so that the construction cost can be significantly reduced along with the material price. Become.

  Further, as shown in FIGS. 1, 2 and 5, the lower flange portion 6a of the pond bottom rail 6 is formed with a groove 6e having a T-shaped cross section that opens in the bottom surface and extends in the rail longitudinal direction. A rail fixing plate 30 provided with a screw hole 30a is fitted into the groove 6e having a T-shaped cross section of the flange portion 6a, and the rail fixing plate 30 is fixed to the rail fixing plate 30 so as to penetrate the rail fixing plate 30. Since the pond bottom rail 6 is attached to the rail bracket 20 by screwing in the bolt 31, the support position of the pond bottom rail 6 with respect to the rail bracket 20 can be freely set, and the alignment at the construction site is possible. Becomes easy.

  Similarly, the lower flange portions 7a and 8a of the upper return rail 7 and the lower return rail 8 have a T-shaped cross section that opens to the bottom surface and extends in the rail longitudinal direction, as shown in FIGS. Grooves 7e and 8e are formed, and rail fixing plates 30 provided with screw holes 30a are fitted into the grooves 7e and 8e having a T-shaped cross section of the lower flange portions 7a and 8a. The upper return rail 7 and the lower return rail 8 are attached to the rail brackets 21a and 21b by screwing the rail fixing bolts 31 through the fixedly arranged rail brackets 21a and 21b. Support positions of the upper return rail 7 and the lower return rail 8 with respect to the brackets 21a and 21b can be freely set, Alignment is facilitated in the field at the time of Engineering.

  Furthermore, if the sliding plates 6d, 7d, 8d are made of a synthetic resin such as ultra high molecular weight polyethylene, the ultra high molecular weight polyethylene is excellent in wear resistance and has self-lubricating properties. The frictional resistance when the 18 and the return shoe 19 slide on the sliding contact plates 6d, 7d, and 8d is reduced, and the driving force can be reduced.

  Moreover, the upper flange portions 6c, 7c, and 8c are formed with grooves 6f, 7f, and 8f that are open on the top surface and have an inverted T-shaped cross section extending in the rail longitudinal direction, and the upper flange portions 6c, 7c, and 8c are formed. The sliding contact plate fixing plate 32 provided with screw holes 32a is fitted into the grooves 6f, 7f, 8f having a reverse T-shaped cross section, and the sliding contact plates 6d, In the state where 7d and 8d are placed, the upper flange portions 6c and 7c are inserted by screwing the sliding contact plate fixing bolts 33 into the sliding contact plate fixing plate 32 through the sliding contact plates 6d, 7d and 8d. , 8c are attached to the upper surfaces of the sliding contact plates 6d, 7d, 8d, so that the sliding contact plates 6d, 7d, 8d are respectively connected to the pond bottom rail 6, the upper return rail 7, and the lower return rail, respectively, as in the prior art. 8 upper hula Di portion 6c, 7c, unlike mount welded to 8c top, it is easy to replace the sliding plate 6d, 7d, 8d.

  In this way, overall weight reduction and cost reduction can be achieved, and workability can be improved by making it easy to align the site at the time of construction, and friction resistance and driving force can be further reduced. The sliding contact plates 6d, 7d, and 8d can be easily replaced.

  Incidentally, in the present embodiment, as described above, the pond bottom rail 6, the upper return rail 7 and the lower return rail 8 are made of synthetic resin rails, and further, from the width center to the width end of the shoe 18. Since the dimension W is set to be longer than the gap C between the width edge of the flight 5 and the side surface of the pond bottom, when a large earthquake occurs, the sewage in the sedimentation basin 1 fluctuates, and the sludge is scraped accordingly. Even when the flight 5 of the machine 2 is swept by sludge, as shown by the phantom line in FIG. 9, even if the leg 18b of the shoe 18 rides on the pond bottom rail 6, the leg 18b of the shoe 18 Never get over the pond bottom rail 6.

  Moreover, if the bottom surface of the leg portion 18b of the shoe 18 is flat, the leg portion 18b of the shoe 18 may remain on the pond bottom rail 6, but the flight 5 A taper portion 18c is formed at the lower end of the leg portion 18b at the time of sludge scraping running, and has a downward slope from the width center side of the shoe 18 toward the width end portion side. As shown, even if the legs 18b of the shoe 18 ride on the pond bottom rail 6, the flight 5 is sludge scraped and the flight 5 sinks toward the bottom of the settling basin 1. When doing so, the taper portion 18c always slides in the inclination direction that is the downward gradient. Therefore, the flight 5 returns to the position where the sliding portion 18a of the shoe 18 rides on the pond bottom rail 6, as shown by the solid line in FIG.

  On the other hand, when a large earthquake occurs, the sewage in the sedimentation basin 1 oscillates, and accordingly, the flight 5 of the sludge scraper 2 tends to sway greatly during the return travel. 10 is formed at the lower end of the leg portion 19b so as to project toward the width center side of the return shoe 19, so that the flange portion 19d is connected to the upper return rail as shown by the phantom line in FIG. 7, or the upper flange portion 8 c of the lower return rail 8, and the return shoe 19 is less likely to be detached from the upper return rail 7 or the lower return rail 8.

  However, in the unlikely event that the return shoe 19 is completely detached from the upper return rail 7 or the lower return rail 8 as shown by the phantom line in FIG. 11, the flight 5 sinks and is shown by the solid line in FIG. Thus, when the leg portion 19b of the return shoe 19 rides on the upper return rail 7 or the lower return rail 8, if the bottom surface of the leg portion 19b of the return shoe 19 is flat, It is also conceivable that the leg 19b of the return shoe 19 remains on the upper return rail 7 or the lower return rail 8. However, the lower end of the leg portion 19b during the return travel of the flight 5 is formed with a tapered portion 19c having a downward slope from the width center side of the return shoe 19 toward the width end portion side. Even if the leg portion 19b of the return shoe 19 rides on the upper return rail 7 or the lower return rail 8 as shown by the solid line, the flight 5 is returned and the flight 5 sinks. When moving, the taper portion 19c always slides in an inclination direction that is a downward gradient. Therefore, the flight 5 returns to a position where the sliding portion 19a of the return shoe 19 gets on the upper return rail 7 or the lower return rail 8.

  As a result, in this embodiment, unlike the shoe 18 and the return shoe 19 in the conventional sludge scraper 2, their bottom surfaces are flat and simply the pond bottom rail 6, the upper return rail 7, and the lower return rail 8 Even if the sewage in the sedimentation basin 1 sways and the flight 5 of the sludge scraper 2 sways greatly when a major earthquake occurs, the pond bottom rail 6 and the possibility that the shoe 18 and the return shoe 19 may be displaced from the upper return rail 7 or the lower return rail 8 or the flight 5 may be dropped off.

  In addition, since the shoe 18 and the return shoe 19 do not advance with a positional shift, the chain 4 can be prevented from riding on the fixed sprocket 10, the drive sprocket 13, the intermediate sprocket 15, or the take-up sprocket 17. Breakage of the chain 4 due to excessive tension and dropping of the chain 4 from the fixed sprocket 10, the drive sprocket 13, the intermediate sprocket 15 or the take-up sprocket 17 are prevented. Further, since the chain 4 on one side of the pair of chains 4 is not dropped from the fixed sprocket 10, the drive sprocket 13, the intermediate sprocket 15 or the take-up sprocket 17, and only the other chain 4 does not travel, flight 5 does not enter a skew state, and can pass through the fixed sprocket 10, drive sprocket 13, intermediate sprocket 15 or take-up sprocket 17, and the chain 4 is not broken.

  Further, since the flight 5 does not travel while dropping from the pond bottom rail 6 and the upper return rail 7 or the lower return rail 8, the flight 5 drives the fixed shaft 9 of the fixed sprocket 10 and the driving sprocket 13. The shaft 12 and the intermediate shaft 14 of the intermediate sprocket 15 and the take-up shaft 16 of the take-up sprocket 17 can be reliably passed, and there is no possibility of the flight 5 being broken or the chain 4 being broken due to excessive tension. Later recovery becomes easier.

  In addition, the rail structure of the sludge scraping machine of this invention is not limited only to the above-mentioned Example, Of course, various changes can be added within the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Sedimentation basin 2 Sludge scraper 3 Hopper 4 Chain 5 Flight 6 Pond bottom rail 7 Upper return rail (return rail)
7a Lower flange portion 7b Web portion 7c Upper flange portion 7d Sliding contact plate 7e Groove 7f Groove 8 Lower return rail (return rail)
8a Lower flange portion 8b Web portion 8c Upper flange portion 8d Sliding contact plate 8e Groove 8f Groove 10 Fixed sprocket (sprocket)
13 Drive sprocket
15 Intermediate sprocket
17 Take-up sprocket
18 shoe 19 return shoe 20 rail bracket 21a rail bracket 21b rail bracket 30a screw hole 31 rail fixing bolt 32 sliding contact plate fixing plate 32a screw hole 33 sliding contact plate fixing bolt 36 first joint plate 37 second joint plate 37a screw hole 38 Joint screw

Claims (3)

A pair of chains that are looped endlessly with respect to a plurality of sprockets so as to be freely circulated in the longitudinal direction in the settling basin, and arranged at a required interval in the width direction perpendicular to the longitudinal direction of the settling basin; ,
A flight attached to span the pair of chains and scraping sludge in the settling basin;
A pond bottom rail that is laid to extend in the longitudinal direction at the bottom of the settling basin and guides sludge scraping on the pond bottom of the flight;
A return rail that is laid to extend in the longitudinal direction of the settling basin and guides the return travel of the flight that has finished the sludge scraping travel;
A shoe attached to the flight and sliding on a pond bottom rail during the sludge scraping traveling of the flight;
In the rail structure of the sludge scraper equipped with the return shoe attached to the flight and sliding on the return rail when the flight returns,
The pond bottom rail and the return rail are made of a synthetic resin rail composed of a lower flange portion, a web portion and an upper flange portion, respectively.
The lower flange portion is formed with a T-shaped groove that opens in the bottom surface and extends in the rail longitudinal direction, and the upper flange portion has a reverse T-shaped groove that opens in the upper surface and extends in the rail longitudinal direction. Forming,
A rail fixing plate provided with a screw hole is inserted into a groove having a T-shaped cross section of the lower flange portion, and a rail bracket is fixedly passed through the rail fixing plate and screwed into the rail fixing bolt. , Attach the pond bottom rail and the return rail to the rail bracket,
In a state where a sliding contact plate fixing plate provided with a screw hole is inserted into a groove having a reverse T-shaped cross section of the upper flange portion, and a sliding contact plate made of synthetic resin is placed on the upper surface of the upper flange portion, The rail of the sludge scraper, wherein the sliding contact plate is attached to the upper surface of the upper flange portion by passing the sliding contact plate and screwing the sliding contact plate fixing bolt into the sliding contact plate fixing plate. Construction.   The rail structure of the sludge scraper according to claim 1, wherein the pond bottom rail and the return rail are made of polyvinyl chloride, and the sliding contact plate is made of ultrahigh molecular weight polyethylene. The first joint plate is brought into contact with one side surface of the web portion in the longitudinal joint portion of the pond bottom rail, and is also suspended on the other side surface of the web portion in the longitudinal joint portion of the pond bottom rail. A longitudinal joint portion of the pond bottom rail is formed by abutting a second joint plate provided with a screw hole, passing through the first joint plate and the web portion, and screwing a joint screw into the second joint plate. Fixed in
The first joint plate is brought into contact with one side surface of the web portion at the longitudinal joint portion of the return rail, and the screw hole is spanned to the other side surface of the web portion at the longitudinal joint portion of the return rail. Is fixed to the longitudinal joint of the return rail by screwing a joint screw into the second joint plate through the first joint plate and the web portion. The rail structure of the sludge scraping machine of Claim 1 or 2 made to perform.

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