JP5895260B2 - Sludge scraping device - Google Patents

Description

  The present invention relates to a sludge scraping apparatus provided in a sedimentation basin in which sludge contained in water is received while the water containing the sludge is received and the water flows.

  2. Description of the Related Art As a sludge scraping device, a device including an endless chain having a scraping member extending in a pond width direction orthogonal to a water flow direction in which received water flows is known. In this sludge scraping device, the scraping member is circulated and moved on the pond bottom side and the water surface side of the settling basin by rotating the endless chain forward. On the upstream side in the water flow direction on the water surface side, a part of the endless chain is wound, and driving wheels for transmitting a driving force for circulating and moving the endless chain to the endless chain are arranged. A downstream end of the endless chain is wound around the downstream side of the water flow direction on the water surface side, and a driven wheel that rotates following the travel of the endless chain is disposed. The scraping member scrapes sludge that has settled on the bottom of the pond when traveling on the bottom of the sedimentation basin, and scum that floats on the water when traveling on the water surface. Further, a rail member is provided on the water surface side of the settling basin so as to extend in the water flow direction and to contact the basin side of the scraping member when the endless chain travels on the water surface side.

  The endless chain is installed with some margin in the circulation direction. This is because if the endless chain is installed in a tight state where there is no margin, the driving force for running the endless chain increases, which may cause a malfunction. By giving a margin in the circulation direction, the endless chain is somewhat slack from the beginning. In addition, the endless chain tends to stretch for a while after the start of traveling, and as a result, the sag tends to increase gradually until a certain period of time from when the chain is installed.

  By the way, in a sedimentation basin in which a sludge scraping device is installed, an endless chain may be detached from a rotating wheel such as a driving wheel or a driven wheel due to an earthquake. It has been found that the endless chain is removed from the rotating wheel because of the effect of sloshing, where the water near the water surface in the settling basin is undulated rather than the direct effect of shaking due to the earthquake. When sloshing occurs, the water surface side part of the endless chain (hereinafter sometimes referred to as the chain water surface side part) swings and the force of the vibration is transmitted to the part of the endless chain that is wound around the rotating wheel. The endless chain may come off the rotating wheel.

As an earthquake countermeasure, a sludge scraping device has been proposed in which an upward regulating portion for suppressing upward swinging of the water surface side portion of the chain is provided in the endless chain (see, for example, Patent Document 1). The rail member of this patent document 1 has an abutting portion where the upper regulating portion abuts from the pond bottom side when the chain water surface side portion swings upward. This abutment portion is defined as a driving wheel when viewed in the pond width direction ( when viewed in the direction in which the rotating shaft of the driving wheel extends) between the driving wheel and the driven wheel disposed on the water surface side. It is arranged at a large interval in the water flow direction (longitudinal direction) . The sludge squeezing device described in Patent Document 1 is configured such that when the chain water surface side portion is likely to swing largely upward due to shaking due to sloshing, the upward restriction portion and the rail member abut. The chain water surface side portion is intended to suppress upward deflection. In the sludge scraping device of Patent Document 1, it is necessary that the upward regulating portion provided in the endless chain that is circulatingly move enters the pond bottom side (downward) from the contact portion of the rail member.

JP 2011-5400 A

Here, in the chain water surface side portion, the endless chain behavior may become unstable, such as sagging on the downstream side in the circulation direction with respect to the portion wound around the drive wheel, causing the endless chain to bend upward. . When the contact part of the sludge scraping device of Patent Document 1 is viewed in the pond width direction ( when viewed in the direction in which the rotation axis of the drive wheel extends) , the drive wheel is in the water flow direction (longitudinal direction). Since they are arranged at a large interval, the endless chain may bend upward between the contact portion and the drive wheel. If the amount by which the endless chain bends upward is large, the upward restricting portion may be located at the same height as the contact portion or above the contact portion. If the upper restricting portion is at the same height as the abutting portion, the upper restricting portion and the abutting portion may collide, and the upper restricting portion or the rail member may be damaged. In addition, if the upward restricting portion does not enter below the contact portion, the endless chain swing suppressing effect cannot be obtained, and the endless chain may be removed from the rotating wheel.

  In view of the above circumstances, an object of the present invention is to provide a sludge scraping device that can reliably prevent an endless chain from being removed from a rotating wheel even if an earthquake occurs.

The sludge scraping device of the present invention that solves the above object is provided in a sedimentation basin in which sludge contained in the water is received while the water containing the sludge flows and the water flows, In the sludge scraping device that scrapes the sludge settled on the pond by the scraping member extending in the pond width direction,
An endless chain that circulates the scraping member on the pond bottom side and the water surface side by having a plurality of the scraping members at intervals and running,
A drive wheel provided on the water surface side upstream of the water flow direction in which the water flows, wherein the endless chain is wound around, and driving force is transmitted to the endless chain to run the endless chain;
A driven wheel that is provided on the water surface side downstream in the water flow direction, the endless chain is wound around, and is capable of rotating following the travel of the endless chain;
A rail member that extends in the water flow direction on the water surface side, and that contacts the pond bottom side of the scraping member when the endless chain travels,
The endless chain has an upper-direction restricting portion that comes into contact with the rail member from the pond bottom side when the water surface side portion swings upward, and on the water surface side, the upper end position of the driving wheel and the upper end of the driven wheel It runs on the bottom of the pond rather than the straight line connecting the
The rail member has an abutting portion with which the upper regulating portion abuts from the pond bottom side when the water surface side portion of the endless chain swings upward.
The abutting portion, when viewed in the pond width direction, extends horizontally from the vicinity of the driving wheel toward the driven wheel, and the horizontal direction from the driving wheel side end to the water flow direction der having a toward the upstream drive wheel side inclined portion inclined upwardly in is,
The driving wheel-side inclined portion, characterized that you have formed substantially along a circular arc shape in a pitch circle of the driving wheel.

The endless chain runs on the pond bottom side with respect to the straight line on the water surface side, and there is a slack between the driving wheel and the driven wheel. According to the sludge scraping device of the present invention, there is provided a driving wheel side inclined portion that is inclined upward from the vicinity of the driving wheel toward the upstream side in the water flow direction and formed in an arc shape substantially along the pitch circle of the driving wheel. Therefore, even if there is the above-mentioned slack, the upward restricting portion can surely enter under the contact portion. By causing the upward restricting portion to enter the lower portion of the contact portion, it is possible to reliably obtain the effect of suppressing the shake. As a result, it is possible to prevent the endless chain from being removed from the rotating wheel.

  Moreover, the said upper direction control part may be provided in the pond bottom side with respect to the said contact part from the said contact part at intervals in the up-down direction, and may oppose the said contact part.

  Further, the driving wheel side inclined portion may extend from the driving wheel side end portion to the upstream side in the water flow direction beyond a position that becomes the upper end of the driving wheel.

  Further, the driving wheel side inclined portion may extend from the driving wheel side end portion to the upstream side in the water flow direction from the driving wheel side end portion to a position in front of the upper end position in the driving wheel.

Further, in the sludge scraping device of the present invention, the horizontal portion extends to the vicinity of the driven wheel,
The contact portion includes a driven wheel side inclined portion that is inclined upward from the driven wheel side end portion of the horizontal portion toward the downstream side in the water flow direction when viewed in the pond width direction. May be.

  Since the driven wheel side inclined portion inclined upward from the vicinity of the driven wheel toward the driven wheel side is provided, even when the water surface side portion of the endless chain travels from the driven wheel side to the driving wheel side, The upper restricting portion can be surely entered downward.

  Further, the drive wheel includes a forward rotation drive that causes the endless chain to travel from the drive wheel side toward the driven wheel side, and a reverse rotation drive that causes the endless chain to travel toward a side opposite to the forward drive. It may be what performs.

  Further, the driven wheel side inclined portion may extend from the driven wheel side end portion to a downstream side in the water flow direction beyond a position that becomes an upper end of the driven wheel.

  Further, the driven wheel side inclined portion may extend from the driven wheel side end portion to the downstream side in the water flow direction from a position that is closer to the upper end of the driven wheel.

  According to the sludge scraping device of the present invention, it is possible to reliably prevent the endless chain from being removed from the rotating wheel even if an earthquake occurs.

It is a sectional side view of the sedimentation basin in which the sludge scraping apparatus which is one Embodiment of this invention was installed. It is the elements on larger scale which expanded the A section of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is a figure which shows the 1st modification of this embodiment. It is a figure which shows the 2nd modification of this embodiment. (A) is a figure which shows the sprocket with a pin used when using a notch chain, (b) shows a mode that a part of notch chain was wound around the sprocket with a pin shown to (a). FIG.

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

  FIG. 1 is a side sectional view of a sedimentation basin in which a sludge scraping apparatus according to an embodiment of the present invention is installed.

  A sedimentation basin 1 shown in FIG. 1 is a pond having a substantially rectangular shape in plan view, surrounded by an upstream wall 1a, a downstream wall 1b, and a pair of side walls 1c. The sedimentation basin 1 accepts water containing sludge such as sewage and rainwater from one end side in the longitudinal direction (left side in FIG. 1), precipitates sludge contained in the received water on the pond bottom 1d, and the other end side. Drain from (right side in Fig. 1). Hereinafter, the left side in FIG. 1 may be referred to as the upstream side, the right side in FIG. 1 may be referred to as the downstream side, and the direction from the left side to the right side in FIG. Moreover, the direction orthogonal to the paper surface in FIG. 1 may be referred to as a pond width direction. In addition, FIG. 1 is the figure which looked at the sedimentation basin in the pond width direction.

  As shown in FIG. 1, the sedimentation basin 1 is provided with a sludge scraping device 10, a scum removing device 30, a drainage basin 40, and a sludge pit 50 according to this embodiment. The drainage basin 40 is provided in the downstream part of the sedimentation basin 1. Further, the sludge pit 50 is provided in the upstream portion of the sedimentation basin 1.

  The sludge scraping device 10 of this embodiment includes an endless chain 11. The endless chains 11 are provided at both ends of the sedimentation basin 1 in the pond width direction, spanned between the pair of chain bodies 101 traveling in the sedimentation basin 1 and the pair of chain bodies 101, in the pond width direction. A plurality of scraping members 12 extending are provided. Each of the chain main bodies 101 provided at both ends in the pond width direction includes a pond bottom track T1 on the pond bottom portion 1d side and a downstream track T2 extending from the pond bottom track T1 toward the water surface W on the downstream side of the settling basin 1. And an upstream chain T3 extending from the pond bottom track T1 toward the water surface W on the upstream side of the settling basin 1 and a circular chain formed by connecting a water surface track T4 on the water surface W side. As the chain body 101 travels on the orbit, the scraping member 12 circulates on the pond bottom 1d side and the water surface W side. In FIG. 1, the chain body 101 is shown as a circular track.

  Sprockets 14 to 17 are arranged at both end portions of the tracks T1 to T4. A part of the chain main body 101 is wound around each of the sprockets 14 to 17, and a portion of the chain main body 101 wound around each of the sprockets 14 to 17 meshes with the sprockets 14 to 17.

  The sprocket 14 is disposed on the upstream side of the water surface track T4. In the following description, this sprocket 14 may be referred to as a drive sprocket 14. A drive shaft 141 is fixed to the center portion of the drive sprocket 14. The drive shaft 141 extends in the pond width direction and is rotatably supported by bearings 142 (see FIG. 4) fixed to the pair of side walls 1c. A drive shaft 141 shown in FIG. 1 is connected to the motor 21 by a drive chain 211. As the motor 21 rotates, the drive sprocket 14 also rotates via the drive shaft 141. The drive sprocket 14 of the present embodiment corresponds to an example of a drive wheel that transmits the driving force to the endless chain 11 and causes the endless chain 11 to travel.

  The motor 21 is a motor that can rotate in both the clockwise direction and the counterclockwise direction in FIG. The motor 21 is normally driven to rotate clockwise in FIG. As the motor 21 rotates in the clockwise direction, the drive sprocket 14 rotates clockwise, causing the endless chain 11 to travel clockwise. Hereinafter, the rotation of the drive sprocket 14 in the clockwise direction in FIG. 1 may be referred to as forward rotation driving, and the endless chain 11 traveling in the clockwise direction in FIG. When the drive sprocket 14 is driven to rotate forward, the portion of the endless chain 11 on the water surface track T4 (hereinafter sometimes referred to as the water surface track portion 11a) travels from the upstream side toward the downstream side.

  The motor 21 has a torque limiter function. For example, if a foreign object is caught in the scraping member 12 attached to the chain body 101 running on the pond bottom 1d and an excessive load is applied to the motor 21, the torque limiter function is activated and the motor 21 is temporarily stopped. . Then, in order to release the foreign matter from being caught, the motor 21 rotates reversely (rotates counterclockwise in FIG. 1) for a short time. As the motor 21 rotates in the reverse direction, the drive sprocket 14 rotates counterclockwise in FIG. 1 and causes the endless chain 11 to travel counterclockwise (so-called reverse movement). Hereinafter, the rotation of the drive sprocket 14 counterclockwise in FIG. 1 may be referred to as reverse drive, and the endless chain 11 traveling in the counterclockwise direction in FIG. 1 may be referred to as reverse rotation. When the drive sprocket 14 is driven in reverse, the water surface track portion 11a travels from the downstream side toward the upstream side.

  The other sprockets 15 to 17 are driven sprockets that rotate following the travel of the endless chain 11. Fixed shafts 151, 161, 171 are passed through the central portions of the sprockets 15-17. The fixed shafts 151, 161, 171 are fixedly arranged so as not to rotate around the shaft. All the sprockets 15 to 17 are rotatable with respect to the fixed shafts 151, 161, and 171. Each of the sprockets 14 to 17 is a rotating wheel that rotates around the drive shaft 141 and the fixed shafts 151, 161, 171 as rotation axes. The sprocket 15 is disposed on the downstream side of the water surface track T4. In the following description, the sprocket 15 may be referred to as an intermediate sprocket 15. The intermediate sprocket 15 corresponds to an example of a driven wheel in the present invention.

  A plurality of scraping members 12 are attached to the entire circumference of the chain main body 101 at regular intervals or substantially evenly in the circulation direction. A pond bottom rail 23 extending in the longitudinal direction of the settling basin 1 along the pond bottom 1 d is fixed to the pond bottom 1 d of the settling pond 1. The scraping member 12 is guided by the pond bottom rail 23 in the pond bottom track T1 to move the sludge settled on the pond bottom 1d.

  In addition, a downstream return rail 25 that is substantially parallel to the pond bottom 1d and extends in the longitudinal direction of the settling basin 1 is fixed to a predetermined height position from the pond bottom 1d on the downstream side of the settling basin 1. ing. The downstream return rail 25 is attached to a plurality of downstream pedestals 251 fixed to each of the pair of side walls 1c. When the endless chain 11 is traveling forward, the scraping member 12 attached to the chain body 101 moves while being guided by the downstream return rail 25 on the downstream side of the downstream track T2.

  Further, an upstream return rail 24 extending in the water flow direction along the water surface W is fixed on the upstream side of the settling basin 1 and in the vicinity of the water surface W. The upstream return rail 24 in the present embodiment corresponds to an example of a rail member in the present invention. The upstream return rail 24 is attached to an upstream pedestal 247 fixed to each of the pair of side walls 1c. The raking member 12 attached to the chain main body 101 moves while being guided by the upstream return rail 24 in the water surface track T4. The upstream return rail 24 will be described in detail later.

  When the endless chain 11 travels forward, the scraping member 12 located on the pond bottom track T1 moves along the pond bottom 1d from the downstream side toward the upstream side. The sludge settled on the pond bottom 1d is scraped toward the upstream sludge pit 50 by the scraping member 12 moving on the pond bottom 1d. The sludge attracted to the sludge pit 50 is discharged outside the sedimentation basin 1 by a sludge pump (not shown).

  Scum is floating on the water surface W of the sedimentation basin 1. When the endless chain 11 travels forward, the scraping member 12 located on the water surface track T4 moves along the water surface W from the upstream side toward the downstream side. The scum floating on the water surface W is scraped toward the scum removing device 30 on the downstream side by the scraping member 12 that moves on the water surface track T4. The scum scraped to the scum removing device 30 side is discharged to the outside of the sedimentation basin 1 by the scum removing device 30 together with the water in the sedimentation basin 1. In addition, the water in the sedimentation basin 1 from which the scum and sludge have been removed passes under the scum removal device and flows into the drainage basin 40, flows from the drainage basin 40 to a drainage channel (not shown), and drains outside the sedimentation basin 1. Is done.

  The chain main body 101 is installed in a state having a moderate margin in the circulation direction from the beginning of installation in the sedimentation basin 1 in order to prevent an increase in driving force for causing the chain main body 101 to travel. The chain main body 101 has a slack amount corresponding to the margin. Further, for a while after the start of traveling, the chain main body 101 tends to stretch due to the familiarity of the chain main body 101, a creep phenomenon, and the like, and as a result, there is a tendency that sagging gradually increases as compared to when it is installed. Note that after the endless chain 11 has traveled to some extent, almost no elongation occurs.

  When the endless chain 11 travels, a travel load generated by the scraping member 12 scraping sludge is applied to the portion of the endless chain 11 located on the pond bottom track T1. When the endless chain 11 is traveling forward, a tension corresponding to the traveling load is generated in a portion of the chain body 101 located on the pond bottom track T1 and the upstream track T3. On the other hand, sagging occurs in portions of the chain body 101 located on the downstream track T2 and the water track T4. FIG. 1 shows a state where sagging has occurred in portions located on the downstream track T2 and the water track T4.

  FIG. 2 is a partially enlarged view in which the portion A of FIG. 1 is enlarged. In FIG. 2, the chain main body 101 is shown with the dashed-dotted line except for one part.

  The chain body 101 is a metal chain in which a plurality of link members 110 are connected. A resin chain may be used as the chain body 101. Each link member 110 is connected by a connecting pin (not shown). In the present embodiment, a link member 110 ′ provided with a stay 113 is arranged every 20 link members 110 connected in the circulation direction of the chain body 101. The stay 113 is for connecting the link member 110 and the scraping member 12 together. The stay 113 and the scraping member 12 are coupled by screws (not shown).

  As shown in FIG. 2, the upstream return rail 24 includes a sliding contact portion 240 in the upper portion and a mounting portion 241 in the lower portion. In the present embodiment, the sliding contact portion 240 also serves as the contact portion in the present invention. The sliding contact portion 240 includes a horizontal portion 242, a driving wheel side inclined portion 243, and a driven wheel side inclined portion 244. The horizontal portion 242 extends horizontally from the vicinity of the driving sprocket 14 to the vicinity of the intermediate sprocket 15 when viewed in the pond width direction. The drive wheel side inclined portion 243 is inclined upward from the end portion on the drive sprocket 14 side of the horizontal portion 242 toward the upstream side. The drive wheel side inclined portion 243 is formed in an arc shape substantially along the pitch circle of the drive sprocket 14. The upstream end surface of the drive wheel side inclined portion 243 is located on the vertical line of the top portion of the drive wheel at the upper end of the drive sprocket 14 when viewed in the pond width direction. However, the drive wheel side inclined portion 243 may extend to the upstream side beyond the position of the top portion of the drive wheel, as indicated by a one-dot chain line in FIG. Moreover, it is good also as a thing shorter than the position of a driving wheel top part to the downstream. Moreover, the drive wheel side inclined part 243 should just incline upward toward the upstream, for example, may be formed linearly.

  The driven wheel side inclined portion 244 is inclined upward from the end portion on the intermediate sprocket 15 side of the horizontal portion 242 toward the downstream side. The driven wheel side inclined portion 244 is formed in an arc shape substantially along the pitch circle of the intermediate sprocket 15. The downstream end surface of the driven wheel side inclined portion 244 is located on the vertical line of the intermediate wheel top portion at the upper end of the intermediate sprocket 15 when viewed in the pond width direction. However, the driven wheel side inclined portion 244 may extend to the downstream side beyond the position of the top portion of the intermediate wheel as shown by a two-dot chain line in FIG. Moreover, it is good also as a short thing to an upstream rather than the position of a middle ring | wheel top part. Further, the driven wheel side inclined portion 244 only needs to be inclined upward toward the downstream side, and may be formed, for example, in a linear shape.

  Further, in the present embodiment, the horizontal portion 242, the driving wheel side inclined portion 243, and the driven wheel side inclined portion 244 are integrally formed, but each portion is formed separately and arranged with a slight gap. May be. In the case of being divided and arranged with a gap, even if each part expands due to heat or the like, the expansion can be absorbed by the gap. Alternatively, the horizontal portion 242 may be divided into a plurality of portions and arranged with a slight gap. When the gap is provided, if the gap is made wider than the length of the link member 110 along the circulation path of the chain body 101, the link member 110 may enter the gap. In order to prevent the link member 110 from entering the gap, the gap is desirably narrower than the length of the link member 110.

  As described above, sagging occurs in the water surface track portion 11a of the endless chain 11 traveling forward. In this embodiment, this slackness is utilized, and the position between the top part of the driving wheel and the top part of the intermediate wheel of the water surface track part 11a is defined as the position that becomes the upper end in the driving sprocket 14 and the position that becomes the upper end in the intermediate sprocket 15. It runs on the bottom of the pond rather than a straight line. More precisely, from a straight line S (indicated by a thin line in FIG. 2) connecting the top portion of the drive wheel that is the upper end of the pitch circle of the drive sprocket 14 and the upper portion of the intermediate wheel that is the upper end of the pitch circle of the intermediate sprocket 15. Also, the track of the portion of the water surface track portion 11a between the drive wheel top portion and the intermediate wheel top portion runs on the pond bottom side. By doing in this way, the winding angle by which the chain main body 101 is wound around the drive sprocket 14 and the intermediate sprocket 15 increases compared with the case where there is no slack. As the winding angle increases, the chain body 101 is less likely to be removed from the drive sprocket 14 and the intermediate sprocket 15. In this embodiment, the winding angle around the drive sprocket 14 is about 100 degrees as a whole, and is wound about 20 degrees on the downstream side of the top portion of the drive wheel. Further, the winding angle of the intermediate sprocket 15 is about 50 degrees as a whole, and the intermediate sprocket 15 is wound about 20 degrees upstream from the top of the intermediate wheel top. That is, in this embodiment, the slack is used to increase the wrapping angles of the drive sprocket 14 and the intermediate sprocket 15 by about 20 degrees.

  In the portion where the horizontal portion 242 of the upstream return rail 24 exists, the scraping member 12 is guided by the horizontal portion 242. For this reason, in this portion, the scraping member 12 does not hang down to the pond bottom side from the position of the horizontal portion 242. Further, since the scraping member 12 does not hang down, the chain main body 101 also does not hang down to the pond bottom side from the predetermined height in the portion where the horizontal portion 242 exists.

  As shown in FIG. 2, the scraping member 12 includes a flight plate 121, a pair of return shoes 122, and a pair of regulating members 123. The flight board 121 is made of stainless steel having a substantially U-shape when viewed in the pond width direction. The return shoe 122 and the regulating member 123 are attached to both ends of the flight plate 121 in the pond width direction so as to be symmetrical with respect to the center of the pond width direction. The restriction member 123 and the return shoe 122 are detachably fixed to the flight plate 121 by screws (not shown).

  3 is a cross-sectional view taken along the line BB in FIG. In FIG. 3, the scraping member 12, the upstream return rail 24, and the upstream pedestal 247 are shown.

  As shown in FIG. 3, the upstream return rail 24 has an L shape that is upside down as a whole in cross section, and the sliding contact portion 240 and the mounting portion 241 of the upstream return rail 24 are integrally formed. Yes. In the present embodiment, the upstream return rail 24 has the same cross-sectional shape over the entire length in the longitudinal direction of the upstream return rail 24. The upstream return rail 24 is attached to both ends in the pond width direction in line symmetry with respect to the center in the pond width direction. The attachment portion 241 of the upstream return rail 24 is fixed to the upstream pedestal 247 with screws (not shown). The return shoe 122 is made of resin and is attached to the pond bottom side of the scraping member 12 located on the water surface track T4. The scraping member 12 located on the water surface track T4 is configured so that the shoe lower surface 122a of the return shoe 122 is in sliding contact with the sliding contact portion upper surface 240a which is the upper surface of the sliding contact portion 240 of the upstream return rail 24, thereby returning the upstream return. It moves while being guided by the rail 24.

  The restriction member 123 includes a rectangular base portion 1231, a lower protrusion portion 1232 that protrudes downward from the base portion 1231, and a pond width direction protrusion portion 1233 that protrudes from the tip of the lower protrusion portion 1232 in the pond width direction. The downward projecting portion 1232 and the pond width direction projecting portion 1233 are integrally formed stainless steel round bars, and are fixed to the base portion 1231 by being welded to the base portion 1231. Moreover, the downward protrusion part 1232 and the pond width direction protrusion part 1233 are carrying out the L shape which reversed right and left as a whole. The pond width direction projecting portion 1233 is below the slidable contact portion lower surface 240b, which is the lower surface of the slidable contact portion 240 of the upstream return rail 24, and is spaced vertically from the slidable contact portion 240 when viewed from above. The sliding contact portion 240 is disposed so as to face the sliding contact portion 240.

  The projecting end surface 1233a of the pond width direction projecting portion 1233 is disposed opposite the side surface 241a of the mounting portion 241 of the upstream return rail 24 in the pond width direction and facing the mounting portion 241. When sloshing occurs due to an earthquake and the water surface track portion 11a swings in the pond width direction, the projecting end surface 1233a of the pond width direction projecting portion 1233 of the regulating member 123 contacts the side surface 241a of the mounting portion 241 of the upstream return rail 24. Since the side surface 241a of the mounting portion 241 and the protruding end surface 1233a are in contact with each other, the scraping member 12 located on the water surface track T4 is suppressed from swinging greatly in the pond width direction. That is, the protruding end surface 1233a corresponds to an example of a lateral direction restricting portion.

  In FIG. 3, one end side of the rake member 12 in the pond width direction and the upstream return rail 24 on the one end side are shown, but the other end side of the rake member 12 in the pond width direction is shown. The regulating member 123 is arranged symmetrically with respect to the center of the pond width direction. Further, on the other end side in the pond width direction, the upstream return rail 24 is arranged line-symmetrically with respect to the center in the pond width direction. The scraping member 12 located on the water surface track T4 is prevented from swinging greatly to the left in FIG. 3 by the restriction member 123 and the upstream return rail 24 shown in FIG. On the other hand, the scraping member 12 located on the water surface track T4 is also prevented from swinging greatly to the right in FIG. 3 by the regulating member 123 on the other end side and the upstream return rail 24 on the other end side.

  Further, when the water surface track portion 11a swings upward, the projecting upper surface 1233b of the pond width direction projecting portion 1233 contacts the slidable contact portion lower surface 240b of the upstream return rail 24 from the pond bottom side. Since the sliding contact portion lower surface 240b and the protruding upper surface 1233b are in contact with each other, the scraping member 12 positioned on the water surface track T4 is suppressed from swinging upward. That is, the protruding upper surface 1233b corresponds to an example of the upward restricting portion in the present invention.

  In the present embodiment, the height interval L1 between the sliding contact portion lower surface 240b and the protruding upper surface 1233b is set to 14 mm. A method for setting the interval L1 will be described later. Moreover, in this embodiment, the overlap width L2 of the pond width direction protrusion part 1233 and the sliding contact part 240 of the pond width direction is set to 20 mm. The overlap width L2 may be a width equal to or larger than a value (here, 8 mm) obtained by subtracting the tooth thickness L4 (see FIG. 4) of the drive sprocket 14 from the chain inner dimension L3 (see FIG. 4) of the chain body 101. With this width, unless the endless chain is disengaged from the drive sprocket 14 or the intermediate sprocket 15, the pond width direction protruding portion 1233 and the sliding contact portion 240 are brought into contact with each other when the scraping member 12 swings above the interval L 1. Can be touched. In addition, in order to make the pond width direction protrusion part 1233 and the sliding contact part 240 contact | abut reliably, it is preferable to make the overlap width L2 into the width | variety more than the said value (L3-L4).

  4 is a cross-sectional view taken along the line CC of FIG. FIG. 4 is a sectional view taken along a vertical line passing through the center of the drive sprocket 14. FIG. 4 shows a state where the scraping member 12 is at the upper end of the drive sprocket 14. Further, the drive chain 211 shown in FIG. 1 is not shown. FIG. 4 shows the upstream end face of the upstream return rail 24, and the upstream end face is hatched.

  The link member 110 constituting the chain body 101 includes a pair of left and right link plates 111 facing in the pond width direction, and a barrel portion 112 connecting the pair of left and right link plates 111. If the lower end of the link plate 111 is positioned radially outward (upward in FIG. 4) from the cutting edge of the drive sprocket 14, the chain body 101 may be detached from the drive sprocket 14. Further, if the lower end of the barrel portion 112 is positioned radially outward from the cutting edge of the drive sprocket 14, the barrel portion 112 may ride on the cutting edge of the driving sprocket 14. In this embodiment, the distance L1 in the height direction between the sliding contact portion lower surface 240b and the protruding upper surface 1233b is defined as an overlap distance L5 (here, 46 mm) from the lower end of the link plate 111 to the cutting edge of the drive sprocket 14 and the barrel portion 112. This is shorter than the meshing distance L6 (33 mm in this case) from the lower end to the blade edge of the drive sprocket 14. Thereby, the possibility that the chain main body 101 is detached from the drive sprocket 14 and the possibility that the barrel portion 112 rides on the cutting edge of the drive sprocket 14 are reduced. In order to reduce these fears more reliably, the interval L1 in the height direction is preferably set to an interval equal to or less than half the overlap distance L5, and more preferably equal to or less than half the meshing distance L6. preferable.

  As described above, the upstream end surface of the drive wheel side inclined portion 243 is on the vertical line of the top portion of the drive wheel at the upper end of the drive sprocket 14 when viewed in the pond width direction (on the same plane as the paper surface in FIG. 4). Is provided. The chain body 101 is wound around the drive sprocket 14 at the top portion of the drive wheel. At the portion of the chain body 101 that wraps around the drive sprocket 14, there is almost no risk of the chain body 101 being bent upward due to the drive load, and the behavior of the chain body 101 is likely to be stable. Further, the portion of the chain body 101 that is wound around the drive sprocket 14 also has a frictional load with the drive sprocket 14, so the possibility of bending upward is lower. In the present embodiment, since the drive wheel side inclined portion 243 extends to a portion where the chain main body 101 hardly bends upward, the protruding portion of the raking member 12 attached to the winding portion in the pond width direction 1233 can surely enter below the sliding contact portion 240 of the upstream return rail 24.

  Similarly, by providing the driven wheel side inclined portion 244, the pond width direction protruding portion 1233 of the scraping member 12 that is traveling in the reverse direction can also surely enter below the sliding contact portion 240.

  Further, in a state where the pond width direction protruding portion 1233 enters below the sliding contact portion 240, the scraping member 12 is suppressed from moving upward and moves along the shape of the sliding contact portion 240. The movement of the raking member 12 attached to the water surface track portion 11a of the chain body 101 is suppressed, so that the water surface track portion 11a is also prevented from moving upward, and the water surface track portion 11a is bent upward. There is no need. As a result, the portion of the chain main body 101 that passes through the driving wheel side inclined portion 243 and the driven wheel side inclined portion 244 is not bent and the winding angle on the driving sprocket 14 and the intermediate sprocket 15 is reduced. The winding angle can be maintained. When the chain body 101 travels in the reverse direction, a tension corresponding to the travel load of the chain body 101 is applied to the water surface track portion 11a. At this time, the water surface track portion 11 a tries to move upward due to the tension, but since the upward movement is suppressed by the sliding contact portion 240, the water surface track portion 11 a is a track along the sliding contact portion 240. It moves cyclically. That is, even when the chain main body 101 travels in the reverse direction, the wrapping angle around the drive sprocket 14 and the intermediate sprocket 15 can be maintained. That is, the sliding contact portion 240 of the present embodiment also functions as a winding angle maintaining member that maintains the winding angle of the drive sprocket 14 and the intermediate sprocket 15.

  As described above, according to the present embodiment, since the driving wheel side inclined portion 243 is provided, the pond width direction protruding portion 1233 of the scraping member 12 attached to the chain body 101 that is running forward is slid. It is possible to surely enter below the contact portion 240. By causing the pond width direction protruding portion 1233 to enter below the sliding contact portion 240, it is possible to obtain an effect of suppressing the shake. As a result, even if sloshing occurs due to an earthquake, it is possible to reliably prevent the chain main body 101 from being detached from the drive sprocket 14 and the intermediate sprocket 15. Furthermore, for the existing sludge scraping device, it is only necessary to replace the upstream return rail 24 and attach the restricting member 123 to the scraping member 12, so that the sludge can reliably prevent the chain body 101 from coming off at low cost. A scraping device can be provided.

  Further, since the driven wheel side inclined portion 244 is provided, the pond width direction protruding portion 1233 of the scraping member 12 attached to the chain main body 101 is placed below the upstream return rail 24 even when traveling reversely. , You can be sure to get in.

  Then, the modification of this embodiment is demonstrated. In the following description, components having the same names as those of the components described so far will be described with the same reference numerals as those used so far. Moreover, the description which overlaps with the description of the sludge scraping apparatus already demonstrated may be abbreviate | omitted.

  FIG. 5 is a diagram illustrating a first modification of the present embodiment. FIG. 5 is a plan view of the vicinity of the drive sprocket 14 from above the settling tank 1. In FIG. 5, the lower side of the figure is the upstream side, and the upper side of the figure is the downstream side.

  In the previous embodiment, the cross-sectional shape of the upstream return rail 24 is the same shape over the entire length in the longitudinal direction of the upstream return rail 24. However, in the modified example, the upstream end of the drive wheel side inclined portion 243 is the same. The shape of the part is different from the previous embodiment. As shown in FIG. 5, in the driving wheel side inclined portion 243 of this modified example, the width in the pond width direction of the most upstream portion is substantially the same as the thickness of the mounting portion 241. In addition, the width gradually increases from a portion on the upstream side toward a predetermined width toward the downstream side, and then extends toward the downstream side with a certain width after reaching the predetermined width. . That is, the upstream end surface 240c of the driving wheel side inclined portion 243 of this modification is an inclined surface inclined to the downstream side with respect to the pond width direction. The predetermined width is the same as the width in the pond width direction of the sliding contact portion 240 in the previous embodiment. By inclining the upstream end surface 240c to the downstream side, even if the pond width direction protrusion 1233 may collide with the upstream end surface 240c, the pond width direction protrusion 1233 escapes in the pond width direction and collides. Therefore, the possibility that the upstream return rail 24 and the regulating member 123 are damaged can be reduced.

  The driven wheel side inclined portion 244 is also formed so that the portion on the most downstream side has a width substantially the same as the thickness of the mounting portion 241 and moves from the portion on the most downstream side toward the upstream side until a predetermined width is reached. The width may be gradually increased. By doing so, the possibility that the upstream return rail 24 and the regulating member 123 are damaged even if the driven wheel side inclined portion 244 collides with the pond width direction projecting portion 1233 during reverse running is reduced. Can do.

  FIG. 6 is a diagram illustrating a second modification of the present embodiment.

  In the previous embodiment, the upstream return rail 24 having an L-shaped cross section upside down is used, and the sliding contact portion 240 also serves as the contact portion. In the second modified example, a contact portion 249 protruding in the pond width direction is provided separately from the sliding contact portion 240. Moreover, in this modification, the downward protrusion part 1232 and the pond width direction protrusion part 1233 of the regulating member 123 are L-shaped as a whole. The pond width direction projecting portion 1233 is below a contact portion lower surface 249a that is a lower surface of the contact portion 249 of the upstream return rail 24, and is spaced apart from the contact portion 249 of the upstream return rail 24 in the vertical direction. When viewed from above, the contact portion 249 is disposed so as to face the contact portion 249.

  In the second modification, when the water surface track portion 11a swings upward, the projecting upper surface 1233b of the pond width direction projecting portion 1233 abuts against the abutting portion lower surface 249a of the upstream return rail 24 from the pond bottom side. In the second modification, the example in which the contact portion 249 protruding in the opposite direction to the protruding direction in the pond width direction of the sliding contact portion 240 is provided, but in the same direction as the sliding contact portion 240. A protruding contact portion 249 may be provided. For example, the cross section of the upstream return rail 24 may be formed in an F shape or an E shape.

  Next, an example in which a so-called notch chain is used for the chain body will be described.

  FIG. 7A is a diagram showing a pinned sprocket used when a notch chain is used, and FIG. 7B shows a part of the notch chain wound around the pin sprocket shown in FIG. 7A. It is a figure which shows a mode that it applied.

  The pin sprocket 81 shown in FIG. 7A is fixed to the drive shaft 141. A pin 812 is provided on each tooth 811 of the pin sprocket 81. The pins 812 protrude from the teeth 811 in the thickness direction of the sprocket 81 with pins. As shown in FIG. 7B, the notch chain 83 is a chain in which a plurality of link members 830 are connected in the same manner as the metal chain body 101 shown in FIG. The link member 830 is made of resin and includes a pair of link plates 8301 facing each other in the pond width direction and a barrel portion 8302 that connects the link plates 8301. The link member 830 is provided with a notch portion 835. A pin 812 provided on the pin-equipped sprocket 81 is engaged with the notch 835. By engaging the notch portion 835 and the pin 812, the rotational driving force of the sprocket 81 with the pin is transmitted to the link member 830, and the notch chain 83 travels on the circular track. Further, a link member 830 ′ provided with a stay 8303 is arranged at every 20 link members 830 connected in the circulation direction of the notch chain 83. The staying member 12 is attached to the stay 8303.

  When the notch chain 83 is used, the height interval L1 between the slidable contact portion lower surface 240b and the protruding upper surface 1233b shown in FIG. 3 is larger than the catch height L8 between the notch portion 835 and the pin 812 shown in FIG. Narrow spacing is desirable. By doing so, the possibility that the engagement between the notch portion 835 and the pin 812 is released is reduced. In order to reduce this possibility with certainty, the interval L1 in the height direction is preferably set to an interval equal to or less than half of the catching height L8.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope described in the claims. For example, in the present embodiment, the return shoe 122 and the regulating member 123 are separate members, but the regulating member 123 may be omitted by providing the return shoe 122 with a downward projecting portion 1232 and a pond width direction projecting portion 1233. Good. Further, the height of the attachment portion 241 may be changed in a part of the upstream return rail 24 in the longitudinal direction. Further, the pond width direction protruding portion 1233 may be provided in the chain main body 101.

  In addition, even if it is a structural requirement contained only in each description of each modification demonstrated above, you may apply the structural requirement to another modification.

DESCRIPTION OF SYMBOLS 1 Sedimentation basin 1d Pond bottom part 10 Sludge scraping device 11 Endless chain 12 Scooping member 14 Drive sprocket 15 Intermediate sprocket 24 Upstream return rail 240 Sliding contact part 242 Horizontal part 243 Drive wheel side slope part 244 Drive wheel side slope part 249 Contact part 1233a Projecting end surface 1233b Projecting upper surface W Water surface

Claims (2)

The sludge contained in the pond bottom that accepts the water containing sludge and flows into the pond bottom while the water flows, and the sludge deposited on the pond bottom extends in the pond width direction. In a sludge scraping device that scrapes by a member,
An endless chain that circulates the scraping member on the pond bottom side and the water surface side by having a plurality of the scraping members at intervals and running,
A drive wheel provided on the water surface side upstream of the water flow direction in which the water flows, wherein the endless chain is wound around, and driving force is transmitted to the endless chain to run the endless chain;
A driven wheel that is provided on the water surface side downstream in the water flow direction, the endless chain is wound around, and is capable of rotating following the travel of the endless chain;
A rail member that extends in the water flow direction on the water surface side, and that contacts the pond bottom side of the scraping member when the endless chain travels,
The endless chain has an upper-direction restricting portion that comes into contact with the rail member from the pond bottom side when the water surface side portion swings upward. On the water surface side, the position that becomes the upper end of the driving wheel and the upper end of the driven wheel It runs on the bottom of the pond rather than the straight line connecting the
The rail member has an abutting portion with which the upper regulating portion abuts from the pond bottom side when the water surface side portion of the endless chain swings upward.
The abutting portion, when viewed in the pond width direction, extends horizontally from the vicinity of the driving wheel toward the driven wheel, and the horizontal direction from the driving wheel side end to the water flow direction der having a toward the upstream drive wheel side inclined portion inclined upwardly in is,
The driving wheel-side ramps, sludge scraped up apparatus characterized that you have formed substantially along a circular arc shape in a pitch circle of the driving wheel. The horizontal portion extends to the vicinity of the driven wheel,
The contact portion has a driven wheel side inclined portion inclined upward from the driven wheel side end portion of the horizontal portion toward the downstream side in the water flow direction when viewed in the pond width direction. The sludge scraping device according to claim 1.