JP3420744B2 - Drop shaft - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical pipe containing a spiral guide plate (also referred to as a drop shaft in this specification) and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, when the surface gradient is steep, manholes are provided at appropriate intervals in order to adjust the flow velocity of the drainage pipe and keep the minimum ground cover, and a step is formed in the drainage pipe between these manholes. The step junction is formed.

The step difference is 1.5 m for each manhole.
It is desirable that the length is less than 0.6 m, and if the length is 0.6 m or more, a sub-pipe will be attached.

Therefore, there is a problem that the construction becomes complicated and difficult when the terrain becomes steep.

Therefore, recently, in a manhole with a sub pipe having a height difference of 10 m or more, a spiral guide plate is built in the sub pipe to gradually reduce the falling energy of drainage such as sewage and to the air to the main pipe. I'm trying to reduce the carry-in and eventually obtain a stable flow.

There are two types of drop pipes, that is, drop shafts, which have a spiral guide plate built therein, that is, a hollow type and an equal pitch type, and they are selectively used depending on the drop height of the drop shaft. Used in larger cases.

That is, in the former, an intermediate guide path having no spiral guide plate is provided between the upper spiral guide plate and the lower spiral guide plate, and each pitch of the upper spiral guide plate and the lower spiral guide plate is different. Is called a hollow type, and the latter is called a drop shaft in which spiral guide plates of equal pitch are continuously provided up and down and are called equal pitch type.

In either case, the drop shaft is mainly composed of a straight tubular large-diameter outer pipe laid vertically.
A spiral guide plate that allows the sewage fixed in the large-diameter outer pipe to flow down while spirally flowing, and a small diameter that is fixed to the shaft core of the spiral guide plate and that is an air cylinder that raises and discharges the air in the sewage. It is composed of an inner tube. The small-diameter inner tube is also called a hollow support shaft of the spiral guide plate.

A proposal for fixing the inner surface of the large-diameter outer pipe to the outer peripheral edge of the spiral guide plate, that is, preventing the spiral guide plate from falling off from the large-diameter outer pipe due to falling energy of sewage flowing down or the like. There have been many proposals for.

For example, in Japanese Unexamined Patent Publication No. 11-236984, a large-diameter outer tube is composed of two split tube bodies, a spiral guide plate is built in, and then both half split tube bodies are bonded and joined to a drop shaft. In particular, sloping grooves are engraved on the inner surface of each half-divided pipe, and the protrusions provided on the outer peripheral edge of the spiral guide plate are fitted into these grooves, and then these two half-divided pipes are bonded and joined. By doing so, it is proposed to firmly fix the large-diameter outer tube and the spiral guide plate.

In this proposal, the spiral guide plates are not limited to one pitch, but several pitches can be used.
It is said that the shaft may be inserted into a hollow portion formed in the axial core portion (inner peripheral edge) of the spiral guide plate, and the inner peripheral edge of the spiral guide plate may be adhesively bonded to the shaft.

[0012] Therefore, according to such a proposal, although there is an advantage that the molding die for manufacturing the drop shaft is not enlarged, and thus a large amount of equipment cost is not required, the following drawbacks are involved.

[0013]

That is, since the large-diameter outer pipe is used as a half-divided pipe body and both pipe bodies are bonded and joined again, the inner diameter (nominal diameter) of the large-diameter outer pipe becomes 250 mmφ to 300 mmφ, and If using a spiral guide plate with several pitches, not only the bonding and joining work for both pipes will be troublesome, but also the drying unevenness of the adhesive used will occur, and the reliability of the strength of the large diameter outer pipe may be impaired. There is.

Further, since the protrusion is formed on the outer peripheral edge of the spiral guide plate, it takes time and effort to form it.

That is, the proposed method of manufacturing the drop shaft still cannot overcome the disadvantage that the drop shaft manufacturing generally requires a lot of manual work and is not suitable for industrial mass production.

Therefore, the present invention is a drop shaft that is inexpensive and guarantees various qualities (reliability for invisible connection between the long outer tube and the spiral guide plate, etc.), but uses as much as possible. It is intended for production.

[0017]

In order to achieve the above object, the gist of the present invention is as follows: 1) A vertical auxiliary pipe having a spiral guide plate as an inner auxiliary pipe of a manhole used for a high-deck pipe. It is composed of a pipe, the vertical pipe is composed of concentric inner and outer double synthetic resin pipes, and since the spiral guide plate is built between these inner and outer pipes, the inner pipe of the outer pipe and the outer face of the inner pipe are formed. The spiral groove is formed by blow molding by the cold parison method, and the outer peripheral edge of the spiral guide plate is screwed into the spiral groove of the outer tube and the inner peripheral edge is screwed into the spiral groove of the inner tube. By doing so, there is a drop shaft characterized in that it is possible to configure a long vertical pipe, and 2) using a concentric inner / outer double synthetic resin pipe in the vertical pipe containing a spiral guide plate, After fixing the inner peripheral edge of the spiral guide plate to the outer surface of the inner pipe, the spiral proposal with the inner pipe The outer peripheral edge of the plate is screwed and fitted into a spiral groove formed by blow molding on the inner surface of the outer pipe, so that the accuracy of the spiral pitch of the spiral guide plate at the time of screwing in is long. However, there is a method of manufacturing the drop shaft characterized in that the screw is smoothly screwed in while maintaining it. 3) In manufacturing the spiral guide plate in a vertical pipe with a built-in spiral guide plate, a synthetic resin is used. After making a large number of spiral cuts substantially parallel to the surface of the thick donut original plate, this is softened by heating, and then the thick donut original plate is placed on a metal forming shaft having a spiral groove on the outer surface. A method for manufacturing a spiral guide plate for a drop shaft, which is characterized in that the spiral guide plate is fitted in and wound around the spiral groove while being stretched in the axial direction, and is then cooled and hardened before being taken out from the molding shaft.

[0018]

The present invention will be described in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is an overall schematic view using a drop shaft of an embodiment of the present invention, FIG. 2 is a schematic view of a material (A) and a mold (B) in a drop shaft manufacturing method of an embodiment of the present invention, and FIG. It is a schematic diagram of a small diameter inner pipe (C) and a large diameter outer pipe (D) with a spiral guide plate of the present embodiment.

In the manhole 2 to which the drop shaft 1 of the embodiment of the present invention is applied, that is, in the manhole 2 with an inner / sub pipe used for a high-drain pipe, the drop shaft 1 is used for the inner / sub pipe. The falling energy of wastewater such as sewage is gradually reduced to prevent scouring of the bottom of the manhole 2 and separate the air in the wastewater.

An outline of the drop shaft 1 will be described. This drop shaft 1 is used in a hollowing-out type or an equal pitch type, and has a vertical large-diameter outer tube 3 made of synthetic resin (PVC),
A synthetic resin (PVC) spiral guide plate 4 built in the large-diameter outer pipe 3, and a synthetic resin (PVC) small-diameter inner pipe (center) fixed to the axial core portion (inner peripheral edge) of the spiral guide plate 4. Tube 5), and the outer peripheral edge 6 of the spiral guide plate 4 into a spiral groove 7 of groove width D, which is blow-molded on the inner surface of the large-diameter outer auxiliary tube 3, into the large-diameter outer tube 3 Since the large-diameter outer pipe 3 and the small-diameter inner pipe 5 are concentric double inner and outer synthetic resin pipes (PVC pipe, polyethylene pipe, etc.), It can be said that the vertical conduit has the spiral guide plate 4 built in between these inner and outer tubes.

The spiral guide plate 4 is attached to the large-diameter outer tube 3
In order to screw and fix into the spiral groove 7 formed on the inner surface of the, the spiral guide plate 4 is fitted and fixed to the outer surface of the small diameter inner pipe 5,
When the spiral guide plate 4 with the small-diameter inner pipe 5 is pushed into the large-diameter outer pipe 3 while being rotated by mechanical means, the spiral guide plate 4 can be screwed in while maintaining the pitch accuracy of the spiral guide plate 4. It can be inserted smoothly and easily and can be firmly fixed.

On the other hand, on the outer surface of the small-diameter inner pipe 5, the large-diameter outer pipe 3
The same pitch as the spiral groove 7 formed on the inner surface of the
When the nominal diameter of the large-diameter outer tube 3 is 250 mmφ, 290 m
m) and the spiral groove 8 having the same groove width D is provided by blow molding, and the inner peripheral edge of the spiral guide plate 4 is fitted into the spiral groove 8 to be firmly integrated.

Since the spiral guide plate 4 is an intermediate product before being attached to the large-diameter outer pipe 3, its outside is open, and therefore the vicinity of the spiral groove 8 is reinforced with an adhesive. It is possible to firmly fix the spiral guide plate 4 and the small-diameter inner pipe 5 by applying or applying FRP.

Therefore, the small-diameter inner pipe 5 serves not only to separate air in the sewage but also to function as a strong support shaft for the spiral guide plate 4. In particular, the small-diameter outer pipe 3 serves as the large-diameter outer pipe 3. It plays the function of maintaining the spiral pitch accuracy when screwing in.

The inner diameter (nominal diameter) of the large-diameter outer pipe 3 is a standard product of 100 to 300 mmφ, especially 250 mmφ, and the outer diameter of the small-diameter inner pipe 5 is about 50 to 150 mmφ, especially about 82 mmφ. Has become.

Now, a method of manufacturing the drop shaft 1 will be described in detail.

First, the manufacturing method of the spiral guide plate 4 will be described. As shown in FIG.
m) PVC plate, for example, outer diameter of about 260mmφ, inner diameter of about 9
Carve out or punch into a 0 mmφ donut plate.

Therefore, the width of the donut plate in the radial direction is substantially formed to the width W of the spiral guide plate 4. For example, when the spiral pitch is 290 mm, this width W is 84 mm.

This donut original plate is attached to a spindle (not shown) of a processing machine such as a lathe and slowly rotated. A cutter having a feed in the axial direction of the spindle (not shown, but preferably a saw for cutting synthetic resin, or the feed may be provided to the spindle) may be used to form a spiral cut 9 until the inner diameter is reached. And the thick doughnut plate 10 with a notch is formed. Therefore, a large number of spiral cuts substantially parallel to the surface of the original plate can be made.

The feed amount of the cutter or the like becomes the thickness (8 to 10 mm) d of the spiral guide plate 4. The thickness d is slightly smaller than each groove width D of the spiral groove 7 of the large-diameter outer pipe 3 and the spiral groove 8 of the small-diameter inner pipe 5 (the gap difference is 0.5.
~ 1 mm).

After heating (maximum about 130 ° C.) and softening the thick doughnut plate 10 with notches, it is stretched in its axial direction (the inner and outer diameters of the thick donut plate 10 are slightly reduced). The spiral guide plate 4 can be obtained by spirally winding the molded shaft 11 shown in FIG. 2 (B) to be cooled and hardened, and rewinding the molded shaft 11 to remove it.

The molded shaft 11 is a cylindrical rod which is made of metal and is not deformed at all by the heat of softening the resin. The outer surface of the molded shaft 11 has the same pitch and the same groove width D as the spiral groove 8 provided on the outer surface of the small diameter inner tube 5. And a spiral groove 12 having a groove bottom diameter is formed.

The outer diameter of the molded shaft 11 is made larger than the outer diameter of the small-diameter inner pipe 5, so that the groove depth of the spiral groove 12 is made about 2-3 times deeper than that of the small-diameter inner pipe 5. Therefore, the spiral guide plate 4 is reliably formed.

Next, a method of manufacturing the small-diameter inner pipe 5 will be described. On the outer surface of a long PVC raw pipe having a pipe length of 2 to 3 m, as shown in FIG.
As shown in the schematic view of (C), a spiral groove 8 having a groove width D that is slightly larger than the plate thickness d at the same pitch as the spiral guide plate 4,
Cold parison method (softening the original tube by heating to introduce pressure fluid or introducing into the tube, or rubber tube inserted into the tube
Blow molding by a method of introducing a pressure fluid into the tube and expanding at a low pressure), and the outer surface of the small-diameter inner pipe 5 is larger than the inner diameter of the spiral guide plate 4 by the depth of the spiral groove 8. Molding the outer surface of.

Next, a method for manufacturing the large-diameter outer pipe 3 will be described. On the inner surface of a long PVC raw pipe having a nominal diameter (inner diameter) standard dimension and a pipe length of 2 to 3 m, a schematic diagram of FIG. As shown, a spiral groove 7 having the same pitch as the spiral guide plate 4 and a groove width D slightly larger than the plate thickness d is blow-molded by the cold parison method, and a TS receiving port is provided at one end of the PVC original pipe. (Rubber ring socket is also acceptable) 13 is molded. Further, a stopper which does not form the spiral groove 7 is provided on the TS receiving port 13 side.

Therefore, in order to fit the inner peripheral edge of the spiral guide plate 4 into the spiral groove 8 of the small-diameter inner tube 5, if one or both (opposite directions) are pushed while being rotated by a mechanical force, The spiral guide plate 4 with the small diameter inner tube 5 can be set.

Next, one or both of the outer peripheral edges of the spiral guide plate 4 with the small-diameter inner tube 5 are fitted into the spiral groove 7 formed on the inner surface of the large-diameter outer tube 3 from the side opposite to the TS receiving port 13 side. By pushing in both (in the opposite direction) while applying rotation by mechanical force, the small-diameter inner tube 5, the spiral guide plate 4, and the large-diameter outer tube 3 can be set, and a long one that constitutes a part of the drop shaft 1 Can be manufactured.

Therefore, in order to use it for the equal pitch type drop shaft 1 having a drop of 10 m, it is sufficient to connect 5 to 3 TS units to connect them. The large-diameter outer tube 3 and the spiral guide plate 4
By forming a stopper for preventing rotation (the spiral groove 7 is not molded downward), the screwed spiral guide plate 4 will not fall off.

In order to use the hollow drop type drop shaft 1, one with a coarse pitch is provided above, one with a fine pitch is provided below, and a straight PVC pipe (synthetic resin pipe) is interposed between them. Just do it.

As described above, in the drop shaft 1, the pitch of the spiral guide plate 4 is largely changed, but in response to the change, most of the drop shaft 1 can be prepared by simply preparing a molding shaft 11 which is an inexpensive molding die. It is possible to handle, and the spiral flow of drainage can be changed to any rotation state from 3 rotations to 7 rotations.
It can be formed by cutting.

That is, the large-diameter outer pipe 3 and the small-diameter inner pipe 5 are connected to each other.
In the case of ludoparison blow, since only the mother board of a desired pitch of the blow molding machine needs to be replaced, the equipment cost is almost zero and the production cost due to the pitch change is not raised as a whole.

In other words, according to the manufacturing method of this embodiment,
The drop shaft 1 having any pitch and rotation can be easily manufactured.

In FIG. 1, 14 is an outlet of the drop shaft 1, and 15 is a bottom plate.

[0044]

According to the invention of claim 1, since the spiral groove by blow molding is formed in the inner and outer pipes which fit the inner and outer peripheral edges of the spiral guide plate, the pipe length of the inner and outer pipes is spirally guided as in the conventional case. It can be stretched to a large width without making it about 1 pitch of the plate, and it can be cut to a short length if necessary, and as a result, the drop shaft can be industrialized at low cost and at the construction site. The work can be simplified.

According to the second aspect of the present invention, when the spiral guide plate is set on the long outer pipe, the inner pipe is fixed to the spiral guide plate. Therefore, the spiral guide plate is screwed while maintaining the pitch accuracy. It can be inserted and, by extension, can be screwed in easily and smoothly.

According to the third aspect of the invention, the spiral guide plate can be mass-produced at low cost by mechanical operation with almost no manual work, and the plate thickness of the spiral guide plate can be arbitrarily changed.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of an example of the present invention.

FIG. 2 is a schematic diagram in a drop shaft manufacturing method according to an embodiment of the present invention.

FIG. 3 is a partial schematic diagram of the present embodiment.

[Explanation of symbols]

1 ... Drop shaft, 2 ... Manhole, 3 ... Large diameter outer tube, 4 ... Spiral guide plate, 5 ... Small diameter inner tube, 7,8 ... Spiral groove

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-11-236984 (JP, A) JP-A-2001-279798 (JP, A) JP-A-9-269086 (JP, A) JP-A-11-293754 (JP, A) JP-A-10-73185 (JP, A) JP-A-11-22868 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16L 51/00-55 / 24 E02D 29/12 E03F 3/04 F16L 11/12

Claims (3)

(57) [Claims] 1. An inner auxiliary pipe of a manhole used for a high-deck pipe is composed of a vertical pipe containing a spiral guide plate, and the vertical pipe is made of concentric inner and outer double synthetic resin pipes. In order to incorporate the spiral guide plate between the inner and outer tubes, spiral grooves are formed on the inner surface of the outer tube and the outer surface of the inner tube by blow molding by the cold parison method. The drop shaft is characterized in that a long vertical conduit can be configured by screwing and fitting the outer peripheral edge of the outer peripheral edge into the outer tube spiral groove and the inner peripheral edge into the inner peripheral tube spiral groove. 2. A vertical conduit containing a spiral guide plate is provided with concentric inner and outer double synthetic resin pipes, and after fixing the inner peripheral edge of the spiral guide plate to the outer surface of the inner pipe, the spiral guide with the inner pipe is provided. The outer peripheral edge of the plate is screwed and fitted into a spiral groove formed by blow molding on the inner surface of the outer pipe, so that the accuracy of the spiral pitch of the spiral guide plate at the time of screwing in is long. The drop shaft manufacturing method is characterized in that it is maintained and smoothly screwed in. 3. When manufacturing the spiral guide plate in a vertical pipe containing the spiral guide plate, after making a large number of spiral cuts substantially parallel to the plate surface of the thick donut plate made of synthetic resin, This is softened by heating, and then, the thick donut original plate is fitted and wound around the spiral groove while being stretched in the axial direction on a metal molding shaft having a spiral groove on the outer surface, and then this is cooled and hardened. Then, the method for manufacturing the spiral guide plate of the drop shaft is characterized in that it is taken out from the molded shaft.