JPH1113119A - Manhole bottom plate in manhole pump system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manhole bottom plate for extremely reducing residual sewage on the manhole bottom plate in a manhole pump system. SOLUTION: The manhole bottom plate in the manhole pump system is composed of a synthetic resin board, which has a concrete placing section 3, in which an opening side wall 5 is projected downwards and which is used for installing a pump, and at least one water collecting recessed section 2 for absorbing water in the pump, while having an annular groove 6, in which an outside diameter is made slightly larger than the inside diameter of a manhole and which is opened upwards and has slits 7 at regular intevals, on an outer circumferential section. The bottom plate is pressed into a manhole bottom section by utilizing the elasticity of the annular groove while a section between the annular groove and the manhole side wall is filled with a sealing material, and concrete is placed from a concrete placing section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a manhole bottom plate in a manhole pump system.

[0002]

2. Description of the Related Art Conventionally, for example, in a sewerage facility, a manhole is provided in the middle of a sewage pipe, and sewage is temporarily stored in the manhole and then pumped up by a manhole pump (submersible motor pump) for feeding. ing. By the way, if the bottom of the manhole is flat, especially when there is no more inflow of sewage, there is a predetermined space between the bottom of the manhole and the pump suction port. It causes the occurrence. Therefore, conventionally, Japanese Unexamined Patent Publication No. Hei 6-280299 proposes to devise a manhole bottom structure. In each of these, a pre-swirl tank, which is a manhole bottom plate made of a synthetic resin plate, is embedded in concrete cast at the bottom of the manhole.

[0003] In the manhole pump system, a detachable submersible motor pump has recently been applied as a pump. This detachable submersible motor pump is shown in FIG.
As shown in FIG. 1, a submersible motor pump main body P composed of a motor and a casing containing an impeller and the like, and a manhole M
Bend 14 installed at the bottom of the
Is connected to a pumping pipe 16. Also, two guide members 16 such as wires are installed from the bend 14 or a fixed portion such as the bottom of the manhole to the top of the manhole M. And the submersible motor pump body P
A hook portion 12 is provided on an upper portion of the discharge side flange 11 to be engaged with an inflow side flange 15 of the bend 14, and the two guide members 16 are held above the discharge side flange 11. Holding portion 13 is provided.
The submersible motor pump main body P is connected to a chain 17 that is pulled up by a winding device (not shown).

Accordingly, as shown in FIG.
6, the hook portion 12 is locked on the inflow side flange 15 of the bend 14, and thereafter, the horizontal distance between the center of gravity of the submersible motor pump main body P and the locking point a in the figure is set to "the arm The discharge side flange 11 of the submersible motor pump main body P is caused by the moment with the weight of the submersible motor pump main body P as a load.
And the submersible motor pump P is ready for pumping operation. Further, if the chain 17 is pulled up, the submersible motor pump main body P is pulled up to the ground by the reverse operation to the above operation, so that the submersible motor pump main body P can be easily repaired on the ground. Reference numeral 18 denotes a power supply cable to the motor.

[0005]

However, since the outer diameter of the pre-swirl tub is smaller than the inner diameter of the manhole, the pre-swirl tub tends to rise from concrete in the process of installing the pre-swirl tub. It is very difficult to prevent lifting using a large number of jigs and the like, and there is a problem that workability is extremely poor. An object of the present invention is to provide a manhole bottom plate in a manhole pump system that can be very easily attached to the manhole bottom by modifying the shape of the manhole bottom plate.

[0006]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, there is provided a concrete installation portion for mounting a pump, which has an opening side wall protruding downward, and at least one water retaining portion for water absorption of the pump. With a recess,
The outer peripheral portion is made of a synthetic resin plate provided with slits at predetermined intervals and opened upward at an outer diameter slightly larger than the inner diameter of the manhole, and provided with an annular groove. In the invention of claim 2,
The upper surface is lowered in a mortar shape toward the water retaining recess. According to the third aspect of the present invention, the downward protrusion amount of the water retaining recess and the side wall of the concrete casting portion are the same. According to the fourth aspect of the present invention, the manhole bottom plate is divided into a plurality of portions, and at least a part of the divided surface is provided with a joining plate portion extending vertically downward. In the invention of claim 5, the height of the joint is the same as the height of the water retaining recess and the side wall of the concrete casting portion.

[0007]

Next, embodiments of the present invention will be described with reference to the drawings. The manhole bottom plate 1 in the manhole pump system according to the present invention is shown in FIGS.
As shown in the figure, the outer diameter is a disk shape slightly larger than the inner diameter of the bottom of the manhole M to be installed, and approximately in the center,
A concrete casting part 3 in which two water retaining recesses 2, 2 and a peripheral side wall 5 of the opening 4 project downward, and a bottom plate 1
An annular groove 6 which is opened upward is provided on the outer periphery of the annular groove 6, and the annular groove 6 is provided with slits 7 at predetermined intervals.
The manhole bottom plate 1 is integrally formed of synthetic resin, preferably glass fiber reinforced plastic (FRP). The depth of the water retaining recess 2 and the concrete casting portion 3 are the same.

Generally, the manhole M is provided such that an opening exposed on the ground surface is eccentric with respect to the axis of the manhole.
Its diameter is small relative to the main body. Therefore, the manhole bottom plate 1 is installed immediately after the main body of the manhole M is completed. That is, although the outer diameter of the manhole bottom plate 1 is slightly larger than the inner diameter of the manhole body, the slit 7 is provided in the annular groove 6 and can be elastically deformed inward. The manhole bottom plate 1 is pressed against the bottom of the manhole body, and the side wall 5 of the concrete casting part 3 can be mounted in a state of contact with the bottom.

When the manhole bottom plate 1 is installed at the bottom of the manhole, an adhesive 8 such as silicon rubber is filled between the annular groove 6 and the side wall of the manhole to prevent water leakage at this portion. After that, the opening 4 of the concrete casting part 3
Cast concrete from. Since the side wall 5 of the concrete placing part 3 is almost in contact with the bottom of the manhole, the concrete is placed only in the concrete placing part 3 and does not flow into other spaces. After the manhole bottom plate 1 is installed at the bottom of the manhole in this manner, the manhole M is completed. Thereafter, the bend 14 is installed on the concrete of the concrete placing part 3 and the guide pipe 16 is installed.
Then, a pump P is installed to provide a manhole pump system. In this embodiment, two pumps P are installed, and the suction port of each pump P is
Within.

Next, in the completed manhole, the manhole bottom plate 1 cannot be inserted through the manhole opening. In this case, the manhole bottom plate 1 has a divided structure. FIG. 3 shows a two-part structure, in which the parts are divided so as to be symmetrical left and right, and joints 9, 9 extending vertically downward are integrally formed on the division surface excluding the concrete casting part 3. The height of the joining portion 9 is the same as the depth of the water retaining recess 2 and the concrete casting portion 3.

Therefore, an adhesive is applied to the opposing surface of each joint portion 9, and first, one piece 1a of the manhole bottom plate 1 is suspended from the opening (not shown) into the manhole M and positioned at a predetermined position. Thereafter, the remaining piece 1b is similarly suspended in the manhole M, and the joint 9 is joined to the joint 9 of the previous piece 1a.
The two grooves 1a and 1b are positioned at predetermined positions by sliding the annular groove 6 into contact with the inner wall of the manhole M while being guided by pressure contact. In this case, since the water retaining recess 2, the concrete placing portion 3, and the joining portion 9 function as a kind of rib, the worker can work on the manhole bottom plate 1 when joining the joining portions 9, 9. it can. After that, the first
As in the embodiment, the annular groove 6 may be filled with the adhesive 8 and concrete may be cast from the concrete placing section 3. In order to further strengthen the joint at the joint,
As shown in FIG. 5, a joint 9 may be provided also on a dividing surface (space) of the concrete casting part 3, and this part may be connected with a bolt and a nut via a through hole 10. Further, the manhole bottom plate 1 is not limited to two divisions, but may be three divisions.

In the above description, the surface of the manhole bottom plate 1 has been described as being flush. However, the manhole bottom plate 1 is inclined downward at least sequentially toward the water retaining recess 2, that is, the wastewater is guided to the water retaining recess 2 in the shape of a mortar. Therefore, it is preferable to minimize the residual amount of wastewater at the bottom of the manhole. Further, in the above description, the manhole bottom plate 1 other than the concrete casting portion 2
Since concrete is not cast below, the amount of concrete used is small and inexpensive. However, an opening may be provided at an appropriate place in the concrete bottom plate 1 and concrete may be cast from here. In this case, the manhole bottom plate 1 tends to float upward according to the casting of the concrete, but the outer end of the annular groove 6 acts like a so-called claw to bite into the inner surface of the manhole M, and there is no fear of rising. .

[0013]

As is apparent from the above description, claim 1
According to the invention, the manhole bottom plate has slits at predetermined intervals on the outer periphery thereof, and is provided with an annular groove having an outer shape slightly larger than the inner diameter of the manhole opened upward, so that it can be easily simply pressed against the manhole bottom. Even when concrete is cast below the manhole bottom plate, there is no need to provide a complicated manhole bottom plate support member to prevent the manhole bottom plate from floating. Claim 2
According to the invention, since the upper surface is lowered toward the water retaining recess, most of the contaminated water can be sucked, and generation of an odor can be suppressed. According to the third aspect of the present invention, since the downward protrusion amounts of the water retaining recess and the concrete casting portion are the same,
When these are placed on the bottom of the manhole, since this portion is reinforced, the worker can work on the bottom plate of the manhole, and the workability is improved. Claim 4
According to the invention, since the manhole bottom plate is divided, it can be inserted from a relatively small upper opening of the manhole, and furthermore, since it has a joining portion extending vertically downward to the dividing surface, it becomes a guide at the time of joining, The joining work is easy. In addition, the use of this joint allows easy and reliable adhesion and integration, and extremely good workability. According to the fifth aspect of the present invention, since the height of the joint portion, the water retaining recess and the concrete placing portion are the same, the effect of the third aspect can be further improved.

[Brief description of the drawings]

FIG. 1A is a plan view showing a first embodiment of the present invention,
(B) is a sectional view taken along the line II-II of (A), and (C) is a perspective view seen from below.

FIG. 2 is an enlarged cross-sectional view of the annular concave portion of FIG.

FIG. 3 is a perspective view showing a second embodiment of the present invention, in which a half is a perspective view from the bottom side.

FIG. 4 is a perspective view showing a third embodiment of the present invention, and a half is a perspective view from the bottom side.

FIG. 5 shows an installation method of a submersible motor pump, and (A)
Shows before installation, and (B) shows after installation.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Manhole bottom plate, 2 ... Recess recess, 3 ... Concrete casting part, 5 ... Side wall, 6 ... Annular groove, 7 ... Slit, 8 ... Adhesive, 9 ... Joint.

Claims (5)

[Claims] 1. A concrete mounting part for pump mounting having an opening side wall protruding downward, and at least one water retaining recess for pump water absorption. The outer peripheral part has an outer diameter slightly larger than the inner diameter of the manhole. A manhole bottom plate in a manhole pump system comprising a synthetic resin plate having slits at predetermined intervals and having an annular groove. 2. The manhole bottom plate in the manhole pump system according to claim 1, wherein an upper surface is reduced in a mortar shape toward the water retaining recess. 3. The manhole bottom plate in the manhole pump system according to claim 1, wherein the amount of downward protrusion of the water retaining recess and the side wall of the concrete casting part are the same. 4. The manhole bottom plate in the manhole pump system according to claim 1, wherein the manhole bottom plate is divided into a plurality of portions, and a joining plate portion extending vertically downward is provided on at least a part of the divided surface. 5. The manhole in a manhole pump system according to claim 1, wherein the height of the joint is the same as the height of the water retaining recess and the side wall of the concrete casting part. Bottom plate.