JP2000144775A - Protection lid raising device for plastic manhole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a raising means when the protection lid of a plastic manhole has sunk. SOLUTION: For a plastic manhole comprising a manhole main body, a rising portion, an inner lid, and a protection lid 5B for covering the inner lid, a following countermeasure has been provided in the case where the protection lid 5B has sunk: the protection lid 5B comprises a base 8A and a lid receiving frame (8B, 9B) receiving a steel lid subjected to a load on road surface and placed on the base 8A loosely fitted to a raised portion. Then, the lid receiving frames 8B, 9B are further divided to upper and lower parts and coupled to adjustable bolts 18, the iron lid is opened and advanced by a hexagonal rod spanner inserted therein, and the upper lid receiving frame 9B is raised and the protection lid 5B is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for raising a protective cover of a small manhole made of hard vinyl chloride for sewage, that is, a plastic manhole.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed a large number of small manholes of this kind made of sewer hard vinyl chloride or the like (hereinafter also simply referred to as plastic) and has obtained many utility model rights. For example, Utility Model Registration No. 2524755,
2524756, 2554322, 2544132
No.).

[0003] Regarding such small manholes, the Japan Sewerage Association has standardized products and construction methods to improve quality. This will be described.

In FIG. 7, a small manhole 1 has an invert portion (manhole main body) 2 and, for example, a diameter of 300 to 300 mm.
It is roughly composed of a rising portion 3 of 350 mmφ, an inner lid 4 and an outer lid (also referred to as a protective lid) 5A.

The inverter 2 is divided into a starting point, a bending point, a confluence point, an intermediate point and a head point, and various types are used.

The joint between the inverter 2 and the rising portion (also referred to as an inspection tube) 3 is mainly formed of a rubber ring socket 6 shown in the drawing and a socket not shown in the drawing.

The foundation of the small manhole 1 to be buried is a sand foundation 7 having a thickness of 10 to 20 cm in the case of high-quality ground.
And squeeze it sufficiently to finish it to the specified height. Of course, if the ground is soft, crushed stone or chestnut stone or the like is laid, and then the sand foundation 7 is formed.

Here, the backfilling operation of the protective lid 5A forms a sufficiently compacted foundation 12 such as a crushed crushed stone on the compacted backfilled high quality soil 11 sufficient to prevent settlement. The thickness (for example, 17 cm) of the foundation 12 is determined in consideration of the road structure. Then, the installation surface for the pedestal 8A is adjusted to the slope of the ground surface.

Next, a base 8A and a lid receiving frame 9A with a lid 10 are provided.
Are installed concentrically with the rising portion 3. Further, a shallow concave portion is formed on the upper surface of the pedestal 8A so that the lower end surface of the lid receiving frame 9A fits therein. The surroundings are evenly backfilled using 13A or the like, and the surroundings of the lid receiving frame 9A are particularly carefully rolled. For example, heated asphalt mixture 14
When laying, carefully roll it.

As described above, in order to prevent the small manhole 1 from the road surface load of a vehicle or the like, the rising portion 3 and the protective cover 5A are separated from each other via a space (for example, about 10 cm). Is a lid (also referred to as an iron lid) 10, a lid receiving frame 9A
And the ground (1) sufficiently compacted via the base 8A
1, 12).

By the way, a small manhole buried by the above-mentioned standardized construction method (construction method disclosed in the above-mentioned utility model gazette) can withstand the repetitive load of a large vehicle or the like under normal conditions. However, due to land subsidence and fluctuation due to aging, an unexpected event such as an earthquake or heavy rain, etc., the protective cover 5A is lowered below the road surface, and the space between the protective cover 5A and the inner cover 4 is lost. The fact that the load is directly applied to the inner lid 4 is found, for example, during inspection. The subsidence is also found by the noise of the vehicle during traffic.

Of course, the protective cover 5A and the inner cover 4 may sink in one place while maintaining this space.

Therefore, when such a situation, especially the former situation, is discovered, conventionally, at least the vicinity of the protective cover 5A is excavated, taken out, and then carefully backfilled as described above.

However, this requires a considerably large-scale excavation for repair work, and a small plastic manhole is required.
However, there is a problem that the excavation work for the repair work is difficult, because it is conveniently applied when the road width is small (although there is a degree of freedom at the time of new construction and it is not so difficult).

In addition, in order to excavate the vicinity of the rising portion 3 made of plastic, which is vulnerable to impact, there is a problem that the earth-moving equipment such as a backhoe cannot be used, so that the excavation must be performed manually.

On the other hand, in a concrete manhole that can be accessed by humans, the road surface is lowered due to the subsidence and fluctuation of the ground or an earthquake, and the manhole cover is brought into a state of being lifted up. It is often observed that there is a step in the surface.

[0017] In addition, it often occurs that the manhole cover is sunk due to road repair work, for example, asphalt coated. Further, a horizontal manhole is buried on an inclined road, and a part of the manhole cover often protrudes from the road surface.

For this purpose, for example, the following cover height adjusting device is provided in advance on the concrete manhole.

That is, a lid receiving frame is placed on a side block of a manhole, and this side block and an outer flange provided on the lower end side of the lid receiving frame are called jack bolts (adjuster bolts, insert bolts or stud bolts). If there is a step between the manhole cover and the road surface, concrete and the like near the cover receiving frame are crushed and removed, and the jack receiving bolt is screwed up to raise and lower the lid receiving frame. Repair work is being carried out in which a spacer or cement mortar is interposed between the side block and the lid receiving frame (for example, Japanese Utility Model Application Laid-Open No. 61-14135).
No. 0, Japanese Utility Model Laid-Open No. 3-108039, and
No. 2,28981, JP-A-8-27821, JP-A-8-209724, etc.).

Further, the lid receiving frame is placed on the side block of the manhole, and the inner flanges provided on the upper end side of the side block and the lower end side of the lid receiving frame are connected to each other with adjuster bolts. Or, when the road surface sinks, a worker enters this manhole, raises and lowers the lid receiving frame by screwing the adjuster bolt, and then repairs the space between the side block and the lid receiving frame. Have been proposed (for example, see
3-17092, JP-A-9-2030065).

Therefore, in order to solve the above-mentioned problems in the plastic manhole, for example, when the above-mentioned two types of repair methods of the general concrete manhole are applied, they cannot be adopted due to the following problems. There was found.

[0022]

In the former method of repairing a concrete manhole, a method of cutting concrete or the like in the vicinity of a lid receiving frame and crushing and removing the cut concrete or the like is used. Includes a small manhole 1
And the conventional countermeasures when the ground of the pedestal 8A subsides cannot be adopted.

In particular, the protective cover 5 of the small manhole 1
A has a special feature that if the surroundings are hardened by concrete, even if the ground (11, 12) supporting the pedestal 8A sinks, the lid receiving frame 9A does not sink (that is, does not sink in appearance). For this reason, this cannot be adopted for this reason. (Of course, in this case, the lid 10 may be opened, and crushed stones or the like may be packed in the lower surface of the pedestal 8A).

In the latter method of repairing a concrete manhole, a worker enters the manhole and screw-adjusts the adjuster bolts. Not applicable to

In short, in the small manhole 1, the protective cover 5A is used therein, and the foundation 12 for supporting the protective cover 5A and the sand foundation for supporting the invert portion (manhole body) 2 are provided. 7 and the space between the protective cover 5A and the inner cover 4 has special circumstances. Therefore, the cover height adjusting device of a general concrete manhole can be applied as it is. It turned out to be impossible.

Therefore, the present invention aims to improve the plastic manhole (small manhole) in accordance with the circumstances peculiar to the plastic manhole by applying a raising device for the first time as a countermeasure after land subsidence. The main object is to make it easier to handle the improvement measures (improve workability) and to make it cheaper like a plastic manhole (reduction of production cost).

[0027]

In order to achieve the above object, the present invention provides: 1) a manhole body, a rising portion, an inner lid covering an upper end of the rising portion, and a space formed by the inner lid. And a protective cover for receiving a road surface load, wherein the protective cover is supported on the ground above the ground for supporting the manhole body. The protective cover is divided into a pedestal loosely fitted to the rising portion and an iron lid that directly receives a road surface load, and is further divided into a lid receiving frame placed on the pedestal, and a plurality of adjuster bolts provided on the lid receiving frame. Is opened by the iron cover and screwed by a rod-shaped tool inserted therefrom to cope with the settlement of the ground supporting the protection cover. 2) Manhole A plastic manhole comprising a body, a rising part, an inner lid covering an upper end of the rising part, and a protective lid covering the inner lid through a space and receiving a road surface load. , The protective lid is composed of a female-threaded pedestal loosely fitted to the rising portion, a lid receiving frame placed on the pedestal, and an iron lid covered by the lid receiving frame, and the female-threaded pedestal and the lid receiving frame are provided. Are connected to each other with an adjuster bolt which is screwed to a female-threaded pedestal, and the adjuster bolt is
A plastic manhole, wherein the iron cover is opened and screwed by a rod-shaped tool inserted therefrom to lightly raise the cover receiving frame with respect to the female-threaded pedestal to increase the height of the protective cover. 3) Manhole body, rising part,
A ground above the ground supporting the manhole body, comprising: an inner lid covering an upper end of the rising portion; and a protective lid covering the inner lid via a space and receiving a road surface load. In the plastic manhole which supports the protective cover, the protective cover supports a pedestal loosely fitted to the rising portion and an iron lid which directly receives a road surface load, and is mounted on the pedestal. Further, after the lid receiving frame is divided into upper and lower parts, the upper and lower parts are joined by a plurality of adjuster bolts, and the adjuster bolts are opened by opening the iron lid and screwed by a rod-shaped tool inserted therefrom. The gist of the present invention provides a protective cover raising device for a plastic manhole, in which the upper cover receiving frame is raised to cope with the subsidence of the ground supporting the protective cover.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to embodiments shown in the accompanying drawings. 1A and 1B show an embodiment of the present invention, in which FIG. 1A is a state diagram before adjustment, and FIG.
FIG. 2C is a view showing an embodiment of the main part of FIG. 1, FIG. 3 is a partially omitted plan view of FIG. 2, and FIG. 4 is another view of FIG. (A) is a plan view of a nut, (B) is a side view of a nut, (C) is a bottom view of a nut, (D) is a plan view of a bolt, and (E) is a side view of a bolt. FIG. 5 (F) is a threaded view of the bolt and nut, FIG. 5 is a view of the second embodiment of FIG. 4, and FIG. 6 is a view of another embodiment of the present invention. Note that the description and illustration of the same or common parts as those in FIG. 7 are omitted, and those in FIG. 7 are applied as they are.

The protective cover 5 according to the embodiment of the present invention comprises a small manhole (plastic manhole) 1 (see FIG. 7).
The same shall apply hereinafter) from road surface loads, and in particular, those which are separated from the inner lid 4 covered on the upper end of the rising portion 2 of the small manhole 1 via a space and separated. It is. This small manhole 1 has the same structure and construction method as those shown in the conventional example.

The protective cover 5 will be outlined. In FIG. 1, the pedestal of this protective lid 5 is the protective lid 5A shown in FIG.
Unlike the pedestal 8A, the pedestal 8 has a female thread made of cast iron.

That is, the female threaded pedestal 8 is roughly composed of a donut-shaped pedestal portion 15 and a cylindrical female threaded portion 17 rising along the inner hole 16 side of the pedestal portion 15. It is configured.

Then, the lid receiving frame 9 for supporting the iron lid is placed on the female threaded portion 17 of the female threaded base 8, and
A plurality of (for example, three) adjuster bolts 18 screwed to the female screw are connected.

When the upper surface of the cast iron cover 10 which is flush with the upper end of the cover receiving frame 9 and covers the cover frame 10 sinks due to an unexpected situation as described above, the cover 10 is opened. An L-shaped bar-shaped spanner in which the adjuster bolt 18 is fitted and turned to a hexagonal bar wrench (not shown, but a hexagonal fitting bolt or a hexagonal fitting nut). When the screw is screwed using, for example, FIG.
When the female threaded pedestal 8 as shown in FIG. 1B sinks at an inclination of about 5 ° as shown in FIG. 1B from the initial state in which the lid receiving frame 9 of FIG. About 5 ° at the top
To raise the slope.

As for the maximum value of the inclination, the upper end of the lid receiving frame 9 can be inclined up to about 10 ° as shown in FIG.

That is, the raised amount of the protective cover 5 of the present invention is inclined at a maximum of about 10 °, and when the protective lid 5 is inclined more than that, the repair is performed by the conventional excavation. Of course, the entire lid receiving frame 9 can be raised as it is to form a space with the inner lid 4 again. On the contrary, sinking the female threaded pedestal 8 in an attempt to form this space requires Cannot be adopted.

That is, when the ground supporting the female threaded pedestal 8 sinks, the lid receiving frame 9 is raised accordingly.
It is not possible to cope with the settlement of only the road surface with the protection lid 5 as it is. However, the lid receiving frame 9 by raising or lowering the burial at the beginning
You can adjust the angle of inclination.

When the gap 19 is formed between the cover receiving frame 9 and the female threaded pedestal 8 by raising the height of the lid receiving frame 9, the high-strength Portland cement or the ultra-high-strength Portland cement (see JISR5210) is injected and filled. To support the lid receiving frame 9. Of course, if the number of adjuster bolts 18 is increased, the road surface load acting on the small manhole 1 without cement can be supported.

Therefore, the work of raising the lid, especially the work dedicated to raising the lid receiving frame 9 for forming a space with the inner lid 4, is performed by opening the lid body 10 and inserting the worker's arm into the hexagonal rod. All that is required is to insert a wrench and turn the adjuster bolt 18, so that the surroundings of the lid receiving frame 9 are not excavated and re-filled. , And only the relatively lightweight lid receiving frame 9 is raised, and the operator only has to put his arm in the manhole and turn the bar wrench, so that the operation becomes extremely simple and small. This is convenient for the small manhole 1 used for the width of the road, and does not perform an operation that damages the rising portion 3 by excavation.

Next, the protective cover 5 of this embodiment will be described in detail. First, the lid receiving frame 9 and the female threaded pedestal 8 will be described. 2 and 3, a substantially cylindrical cast iron lid receiving frame 9 has, for example, an outer diameter of 440 mmφ and a height of 110 mm.
A fitting surface 20 for covering the cast iron lid 10 is formed on the upper side inside thereof, and an inner flange 21 is formed on the inner lower end thereof.
Are formed. In FIG. 3, reference numeral 22 denotes a hook engaging portion opposing the hinge.

The inner flange 21 protrudes inward with a width of about 45 mm, and a plurality (three) of elongated bolt insertion holes 23 are formed in the inner flange 21 at regular intervals. A plurality (three) of cement injection holes 24, 24,
... is drilled. The bolt insertion slot 23 is formed in a radially elongated hole so that the lid receiving frame 9 can be inclined up to about 10 ° as described above even when the adjuster bolt 18 is inserted.

The female threaded pedestal 8 has the substantially donut-shaped pedestal portion 15 and the cylindrical female threaded portion 17 standing up along the inner hole 16 side of the pedestal portion 15 as described above. And a polymer concrete (referred to as a resin concrete in which an aggregate is bonded with a polymer material such as a thermoplastic resin without using cement).

A thick inner flange 27 is provided on the upper end side of the cylindrical female screw perforated portion 17.
, A plurality of (three) female screw holes (metal nuts) 28, 28,. In addition,
If the nut is fitted on the back surface of the thick inner flange 27 in a detent shape, it is not necessary to perform insert molding.

At the upper end of the female screw hole 28, there is formed a shallow recess 30 into which a disc-shaped support nut 29 is fitted. At the lower end of the female screw hole 28, a notch portion through which the lower part of the adjuster bolt 18 is inserted. 31 is formed, and the adjuster bolt 1 is formed.
8 is easy to ascend and descend. A bulging portion 32 is formed outside the female screw hole 28 to provide strength.

Therefore, although the lid receiving frame 9 is placed on the female threaded pedestal 8 and connected with the adjuster bolts 18, if the lid receiving frame 9 is to be raised, it is only necessary to screw the adjuster bolts 18. That is, the adjuster bolt 18
Is raised by being screwed into the female screw hole 28, the lid receiving frame 9 is lifted by the disc-shaped support nut 29, and only the lid receiving frame 9 with the lid 10 can be raised.

Next, this SUS adjuster bolt 1
8 will be described. In FIG. 4, the adjuster bolt 18 includes a bolt 33, a disc-shaped support nut 29, and a semi-bag holding nut 34.

The bolt 33 is a so-called hexagonal (or square) socket head bolt, and has an external thread (M16) cut over its entire length in the axial direction. This bolt 33
Is formed with a hexagonal deep hole 35 at the head thereof, and this hexagon has a facing distance of 10 mm. The screw 33 is driven by 6
This is performed by inserting and turning a hexagonal bar wrench (not shown) into the deep hole 35.

The bolt 33 has a disk-shaped support nut 2
9 is screwed, and the disk-shaped support nut 29 has an outer diameter of 2 mm.
4 mmφ, 7 mm thick, and the shallow dish recess 30
It is large enough to fit inside.

An R is formed on the upper edge of the disc-shaped support nut 29 to form an inverted bowl shape so that there is no problem even if the lid receiving frame 9 is tilted by about 10 °. Friction caused by screw rotation is reduced.

A small pipe-shaped semi cap nut 34 is screwed to the bolt 33 (a nut that covers the head of the bolt 33 and is penetrated and is called a semi cap nut). In a substantially upper half of the inner surface of the small pipe of the semi-bag presser nut 34, a hexagonal (or square) through hole 36 having a facing distance of 14 mm larger than the hexagonal deep hole 35 is formed. A square wrench (not shown) can be fitted closely, and a female screw (M16) 37 screwed to the bolt 33 is cut in the lower half thereof.

A collar 38 is formed at the lower end of the outer surface of the small pipe of the semi-bag holding nut 34, and a lower edge of the collar 38 is
Is formed so that there is no problem even if the lid receiving frame 9 is inclined by about 10 °, and the friction with the inner flange 21 due to the screwing rotation is reduced.

Accordingly, the disk-shaped support nut 29 screwed to the bolt 33 is positioned according to the thickness of the inner flange 21. Bolt 33 with this disk-shaped support nut 29
Is screwed into the female screw hole 28 to be erected. Next, a portion of the bolt 33 projecting above the disk-shaped support nut 29 is inserted into the bolt insertion slot 23 of the inner flange 21 of the lid receiving frame 9 to further project on the inner flange 21. A semi-bag holding nut 34 is screwed onto the upper portion of the bolt 33 with a slightly large hexagonal wrench (not shown), and the inner flange 21 is firmly held together with the disk-shaped support nut 29.

As described above, the lid receiving frame 9 and the pedestal 8 with the female thread can be firmly connected by the adjuster bolt 18.

In order to raise the lid receiving frame 9 with respect to the female threaded pedestal 8, a hexagonal bar wrench (not shown) is passed through the hexagonal through hole 36 of the semi-bag holding nut 34, and the bolt 33
Into the hexagonal deep hole 35 so as to fit closely. Then
If this hexagonal bar wrench (not shown) is turned in a counterclockwise direction, the bolt 33 is screwed into the female screw hole 28 and rises, and the disc-shaped support nut 29 also rises while turning integrally.
By lifting the inner flange 21, only the lid receiving frame 9 with the lid 10 can be lightly raised.

According to the adjuster bolt 18, a small hexagonal wrench can be used, so that the work of raising the inside of the narrow protective cover 5 is light and easy.

Next, with the lid 10 open, ultra-high strength Portland cement is injected from the cement injection hole 24,
The gap 19 between the female threaded pedestal 8 and the lid receiving frame 9 is filled up. In this case, if the cement does not adhere to the rising portion 3, unlike the concrete manhole, the cement may protrude inside.

Next, another embodiment of the adjuster bolt 18A will be described. In FIG. 5, the SUS adjuster bolt 18A includes a hexagonal head bolt 39, a hexagonal support nut 40 screwed to the bolt 39, and a hexagonal support nut 40 having a spherical top surface, and a hexagonal support nut 40 having a spherical top surface. And a square holding nut 41. A small-diameter insertion portion 43 in which the male screw (M16) 42 is not cut is formed on the tip end side of the hexagonal head bolt 39.

Therefore, this hexagonal head bolt 39
A square holding nut 41 is screwed into the bolt insertion slot 23 of the inner flange 21, and then a hexagonal support nut 40 is screwed into the bolt 39, and the inner flange 21 is fastened with both nuts 40 and 41. Hold firmly.

Then, the lid receiving frame 9 with the bolt 39 is placed on the female threaded pedestal 8. At this time, the small-diameter insertion portion 43 of the bolt 39 is inserted into the female screw hole 28, and the hexagonal head of the bolt 39 is inserted. When rotated by a wrench (or wrench) (not shown), the bolt 39 is screwed into the female screw hole 28, and the lid receiving frame 9 and the female screw pedestal 8 are tightly coupled.

Therefore, when trying to raise the lid receiving frame 9, the hexagonal head of the bolt 39 may be rotated reversely by a box-shaped wrench. In this specification, a driver
And a bar-shaped tool including a spanner and a wrench.

Next, a protective cover 5B according to another embodiment of the present invention will be described. In FIG. 6, this protective lid 5B
Is composed of a doughnut-shaped pedestal 8A made of a composite resin and a frustoconical frustum-shaped lid made of cast iron that supports an iron lid. 9B and the lower lid receiving frame 8B are connected by the adjuster bolts 18 described above, and when the protective lid 5B is raised, the adjuster bolts 18 are screwed upward to move the upper lid receiving frame 9B to the lower lid receiving frame 8B. In addition, the pedestal 8A is lifted from the initial state of the horizontal embedding to an inclined state of about 5 ° to 10 ° or by lifting the whole horizontally.

As shown in FIG. 2, an inner flange 21B is formed at the lower end of the upper lid receiving frame 9B, and a plurality of (three) elongated holes 23B, 23B for bolt insertion are formed in the inner flange 21B at regular intervals. , And a plurality (three) of cement injection holes (not shown) are formed.

The lower lid receiving frame 8B is provided with an outer flange at its lower end similarly to that of FIG. 7, and is fitted into a shallow recess on the pedestal 8A.
Are formed and joined to the inner flange 21B of the upper lid receiving frame 9B, and a plurality (three) of the inner flange 21C is provided at a position coinciding with the positions of the bolt insertion slots 23B, 23B,. A nut pocket 32B is formed.

A hexagonal nut 28B made of SUS, which is screwed up and down by the adjuster bolt 18 described above, is accommodated in the nut pocket 32B in a stopped state. Therefore, the nut pocket 32B has an upper opening shape,
The adjuster bolt 18 can be erected, and an insertion hole through which the adjuster bolt 18 can freely move up and down is formed.

The depth of the nut pocket 32B is at least the hexagonal nut 28B and the disc-shaped support nut 2B.
9 are equal to each other, but of course, they may be deeper than these heights.

In the protective lid 5B constructed as described above, the lid receiving frames (9B, 8B) are made of cast iron, which is not only convenient and reliable as a conventionally used and reliable lid receiving frame, but also a commercially available hexagon nut. 28B can be used, so that a predetermined engagement screw thread can be obtained, and the screw advance / retreat of the adjuster bolt 18 can be stabilized, and the configuration can be made at low cost.

The structure of the adjuster bolt 18 and the operation using the hexagonal wrench are the same as described above, and will not be described.

In order to accommodate the hexagonal nut 28B in the nut pocket 32B in a detent-like manner, the inner surface of the nut pocket 32B is made hexagonal, and the hexagonal nut 28B is positioned from the top of the pocket.
The square nut 28B may be simply dropped and accommodated, and the nut pocket 32B is also provided with an opening on the inner surface as shown in FIG. 6, that is, the pocket is formed in an upward U-shaped step, The hexagon nut 28B inserted from here may be fixed with an adhesive or the like. In this case, nut pocket 32B
Can be made compact.

Incidentally, the plastic manhole 1 in the present specification includes a public squeegee made of PVC.

[0069]

According to the present invention, a plastic man-housing
When the protective cover of the wrench rises, the adjuster bolts provided on the lid receiving frame are screwed up with a stick-shaped tool with the iron lid open and the hands inserted. Therefore, it is possible to solve the above-described problems of the present invention, such as not raising the work due to the above, and not damaging the rising portion.

In particular, since the lifting operation is completely unrelated to the manhole body, the lifting method is peculiar to the plastic manhole, and it is possible to provide a simple lifting device with a simple structure and low cost. it can.

Further, since the subsided ground is regarded as the compacted ground and used, and the ground is raised by the amount of the subsidence, the operation can be particularly simplified.

Further, since only the small-diameter lid receiving frame or the upper lid receiving frame is raised by the adjuster bolts, a bar-shaped tool can be used, and the work in the narrow lid receiving frame can be performed.

In particular, in the case of a plastic manhole, although the ground between the invert portion (2) and the pedestal (8A) is sufficiently compacted, it is excavated once and then buried. Just because it is the ground that has been returned, unlike the meeting place,
Just because you need a certain depth (for example, about 1 m or more)
This part is land subsidence (not subsidence due to special circumstances,
Although there is a risk of natural subsidence due to aging), the means for raising and the amount of plastic manholes are good for the special circumstances of such plastic manholes, and in general, the present invention is suitable for plastic manholes. be able to.

[Brief description of the drawings]

FIG. 1 is an embodiment of the present invention.

FIG. 2 is a diagram showing an embodiment of a main part of FIG.

FIG. 3 is a partially omitted plan view of FIG. 2;

FIG. 4 is another embodiment of the main part of FIG. 1;

FIG. 5 is a view of a second embodiment of FIG. 4;

FIG. 6 is a view showing another embodiment of the present invention.

FIG. 7 is a conventional example.

[Explanation of symbols]

1 ... Plastic manhole, 2 ... Manhole body, 3
... Rising part, 4 ... Inner lid, 5 ... Protective lid, 8 ... Base with female thread, 7,12 ... Basic, 9 ... Lid receiving frame, 10 ... Lid, 18 ...
Adjuster bolt

Claims (3)

[Claims] 1. A manhole main body, a rising portion, an inner lid covering an upper end of the rising portion, and a protective lid covering the inner lid through a space and receiving a road surface load. Become
In a plastic manhole in which the protective lid is supported on the ground above the ground supporting the manhole body, the pedestal in which the protective lid is loosely fitted to the rising portion and a road surface load are directly applied. Opening the iron cover and screwing a plurality of adjuster bolts provided on the cover receiving frame with a rod-shaped tool inserted therefrom, supporting the receiving iron cover and dividing it into a cover receiving frame placed on the pedestal. The protection lid raising device for a plastic manhole, which addresses the settlement of the ground supporting the protection lid. 2. A manhole body, a rising portion, an inner lid covering an upper end of the rising portion, and a protective lid covering the inner lid through a space and receiving a road surface load. Wherein the protective lid comprises: a female threaded pedestal loosely fitted to the rising portion; a lid receiving frame placed on the pedestal; and an iron lid covered by the lid receiving frame. The female-threaded pedestal and the lid receiving frame are joined by an adjuster bolt that is screwed to the female-threaded pedestal and erected, and the adjuster bolt is opened by opening the iron lid and screwed by a rod-shaped tool inserted therefrom. An apparatus for raising a protective cover of a plastic manhole, wherein the protective cover is raised by lightly raising a cover receiving frame with respect to a female-threaded pedestal. 3. A manhole body, a rising portion, an inner lid covering an upper end of the rising portion, and a protective lid covering the inner lid through a space and receiving a road surface load. Become
In a plastic manhole in which the protective lid is supported on the ground above the ground supporting the manhole body, the pedestal in which the protective lid is loosely fitted to the rising portion and a road surface load are directly applied. And a lid receiving frame placed on the pedestal and supporting the receiving iron lid, and further dividing the lid receiving frame into upper and lower parts and connecting them with a plurality of adjuster bolts. The protective cover raising device for a plastic manhole, characterized in that the upper cover receiving frame is raised by screwing with a rod-shaped tool inserted therefrom, thereby coping with the settlement of the ground supporting the protective cover. .