JPH0513796Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a circumferentially inverted bottom block for a manhole, which constitutes the bottom plate portion of the manhole.

(b) Prior art The manhole bottom block that constitutes the bottom plate of the manhole is usually
Manufactured for each manhole.

An example of a conventional manhole bottom block is shown in FIGS. 6 to 9. In Figures 6 and 7, 1 is the manhole body buried underground, 2 is the lid, 3 is the bottom block that constitutes the bottom plate of the manhole body 1, and 4 is connected near the bottom of the manhole body. 5 is an outflow pipe connected near the bottom of the manhole main body, 9 is an inclined wall of the manhole, 10 is a straight wall of the manhole, 11 is a bottom wall of the manhole, and 12 is a chestnut.

As shown in FIGS. 8 and 9, the bottom block 3 has a cone-shaped upper surface 3a that slopes downward from the outer peripheral edge toward the center, and an inflow pipe 4 is provided on the upper surface. Inverts 3b and 3c (water guide grooves) connecting 4A and the outflow pipe 5 are formed.

Generally, the planar arrangement of the inflow pipe and the outflow pipe in each manhole is different from each other, so the planar shape of the invert formed in the bottom block 3 is also different for each manhole. , it is possible to pre-fabricate various types of bottom blocks with different planar shapes for the invert, or to create a bottom block with a channel structure that matches the planar arrangement of the inflow pipe and outflow pipe at the manhole installation location. Methods such as manufacturing by construction have been implemented. but,
In the former method, in which many types of bottom blocks with different invert planar shapes are manufactured in advance, there is a problem that the cost of the bottom block increases because it requires a large amount of cost to manufacture and store the bottom block. On the other hand, in the latter method of manufacturing the bottom mass on-site, it is necessary to create a formwork for the bottom mass for each manhole and pour concrete, so the manhole production cost is higher than in the former case. The problem was that it took a long time to install the manhole, and it was difficult to work inside the narrow manhole.

In manholes, the installation angle and diameter of the inflow pipe often differ depending on the site compared to the outflow pipe. Angle R of invert (water guide groove) 3c in Fig. 7
is not uniform depending on the site. In order to accommodate the conventionally used bottom blocks with inverted (water guide grooves), it was necessary to manufacture many products with different angles of the water guide grooves where the inlet communicated with the outlet, which resulted in high costs. For example, even if the installation angle of the inflow pipe differs by 3 to 4 degrees from the outflow pipe, there is a need for a water guide groove that corresponds to the difference. In addition, the size of the water guide groove was adjusted depending on the diameter of the pipe to which it was attached, so a large number of different types were needed. In other special cases, manhole installation was carried out on-site using formwork for water channels. but,
In this case as well, it was difficult to work inside the narrow manhole, and there were also problems in that complete construction was not possible.

(c) Problems to be solved by the invention This invention has a common structure that can be used for all manholes, regardless of the installation angle and diameter of the inflow and outflow pipes.
Another object of the present invention is to provide a manhole bottom block that can be mass-produced, can be manufactured at a lower cost than conventional ones, and has improved workability.

(d) Means for Solving the Problems The circumferential inverted bottom block for manholes according to the present invention has an outer diameter slightly smaller than the inner diameter of the manhole, and has a central bulge 6b to form an annular flow around the outer periphery of the upper surface. defining a passage 6a and an annular passage 6
a is inclined with respect to the horizontal plane, and the annular flow path 6a
is formed by a concave surface that rises from the upper edge of the outer periphery of the bottom block 6 toward the central bulging portion 6b.

(e) Embodiments Examples of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of an embodiment of a circumferential invert bottom block for a manhole according to the present invention, FIG. 2 is a front view of FIG. 1, and FIG. 3 is a right side view of FIG. 1.

In the circumferential invert bottom block 6 for a manhole of the present invention, an annular flow path 6a inclined with respect to a horizontal plane is formed along the outer peripheral edge, and a region 6b surrounded by the annular flow path 6a is formed in the annular flow path 6a. It is formed into a convex curved surface higher than that of the annular flow path 6a, and an inclined groove 7 having the same slope as the annular flow path 6a is formed in the center of the convex curved surface. The outer periphery of the bottom block 6 is a concrete inverted bottom block whose diameter is slightly smaller than the inner periphery of the manhole. The inflow pipe is connected to a high part of the annular flow path 6a, and the outflow pipe is connected to a high part of the annular flow path 6a.
By connecting the inflow pipe port and the outflow pipe port to the inclined groove 7 so that they are in a straight line, the flowing water can be guided by the shape of the convex curved surface. Since the outer diameter is smaller than the inner diameter of the manhole, it can be applied to general manholes and the construction work is easy.

FIG. 4 shows a cross-sectional view of a manhole having three inflow pipes 4, 4A, 4B and one outflow pipe 5, in which the bottom mass 6 of the present invention is applied and constructed, and FIG. It is a sectional view taken along the line - in the figure.

At the time of construction, the bottom block 6 is suspended in an already installed manhole and installed in accordance with the inclination angle of the annular flow path 6a. Next, the inner circumference of the manhole and the bottom block 6
The gap with the outer periphery is filled with mortar 8 for preventing water leakage. Further, when constructing the mortar 8, the inside of the manhole can be slightly sloped and the cross section can be made into a semicircular running water groove.

The outflow pipe 5 is installed at the lowest part of the slope of the annular flow path 6a, but no matter what angle the inflow pipes 4A and 4B are opened at, the installation pipe opening is connected to the annular flow path 6a.
It is installed at an appropriate location in part a. Furthermore, an inclined groove 7 in the center of the bottom block 6 is inclined from the inflow side to the outflow side.
Since this is provided, running water can flow smoothly when the inflow pipe side and the outflow pipe side are connected in a straight line. This central inclined groove 7 may not be provided if necessary.

The bottom block 6 of the present invention is constructed by marking the lowest part of the annular channel 6a with an exit mark and providing an embedded nut for hanging it into the manhole so that the direction of drainage drainage can be seen at a glance. can be facilitated.

According to the bottom block of the present invention, the bottom block can be fabricated before construction and can be quickly, easily, and inexpensively constructed in any manhole with any condition of the inflow pipe or outflow pipe. It can be smoothly discharged from the bottom block through the annular flow path and the inclined flow path of the inclined groove to the outflow pipe.

(F) Effects of the invention The circumferential invert bottom block for manholes of the invention is
When installed in the constructed manhole, an annular flow path 6a inclined with respect to the horizontal plane is formed along the outer peripheral edge, and an area surrounded by the annular flow path becomes a convex curved surface higher than the annular flow path. The manhole is an inverted concrete bottom block whose outer periphery has a diameter slightly smaller than the inner periphery of the manhole, allowing water from the inflow pipe to drain smoothly. There is no need to form a notch in the bottom block for this purpose.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of the circumferential invert bottom block for manholes according to the present invention, Fig. 2 is a front view of Fig. 1, Fig. 3 is a right side view of Fig. 1, and Fig. 4 is the same. A cross-sectional view showing the construction state of the example, FIG. 5 is a cross-sectional view taken along the - line in FIG. 4,
Fig. 6 is a vertical sectional view of a conventional manhole with a bottom block, Fig. 7 is a sectional view taken along the - line in Fig. 6, and Fig. 8 is a longitudinal sectional view of a manhole with a conventional bottom block.
The figure and Figure 9 are the - line and - line in Figure 7.
FIG. 1... Manhole body, 2... Lid, 3... Bottom block, 3a... Top surface, 3b, 3c... Invert (water guide groove), 4, 4A, 4B... Inflow pipe, 5... Outflow pipe, 6 ... Bottom mass, 6a ... Annular channel, 6b ...
Convex curved area, 7... Slanted groove, 8... Mortar, 9... Manhole slanted wall, 10... Manhole straight wall, 11... Manhole bottom wall, 12... Split chestnut.

Claims (1)

[Scope of utility model registration request] The outer diameter thereof is configured to be slightly smaller than the inner diameter of the manhole, and an annular flow path 6a is defined at the outer peripheral edge of the upper surface by the central bulging portion 6b.
is inclined with respect to the horizontal plane, and the annular flow path 6a is formed by a concave surface rising from the upper edge of the outer periphery of the bottom block 6 toward the central bulge 6b. .