Branch pipe liner bag and pipe lining method

A branch pipe liner bag immune to damage caused by a cutter is provided. In the branch pipe liner bag having a flange formed at an end of a hardenable resin impregnated bag which comprises a tubular resin-absorbent material impregnated with an unhardened liquid hardenable resin, a cylindrical anti-piercing protector 3 is embedded adjacent to the flange. According to a pipe lining method implemented using the branch pipe liner bag according to the present invention, the branch pipe liner bag adjacent to the flange is, after a branch pipe is lined, protected by the anti-piercing protector, and therefore, in a piercing work thereafter of a main pipe liner bag, the branch pipe liner bag is immune from damage caused by a cutter, thereby eliminating a problem such as infiltration of the underground water into the main pipe from a damaged portion.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a branch pipe liner bag for lining an 
inner wall of a branch pipe which becomes too old to perform properly and 
a pipe lining method which may be implemented using the branch pipe liner 
bag and a main pipe liner bag. 
2. Description of the Related Art 
When a pipe-line laid underground such as a sewage pipe or the like becomes 
defective or too old to perform properly, the pipe is repaired and 
rehabilitated employing a pipe lining method for lining the inner wall 
thereof without being dug out from the underground. This non-digging 
method of repairing an underground pipe has been known and practiced 
commonly in the field of civil engineering. 
The pipe lining method utilizes a pipe liner bag made of a flexible 
resin-absorbent material, having the outer surface thereof covered with a 
highly air-tight film, impregnated with an unhardened liquid hardenable 
resin. The pipe liner bag is turned inside out to be inserted deeper into 
the pipe-line (this manner of insertion shall be called "everting" 
hereafter) by pressurized fluid, and then the pipe liner bag is pressed 
against the inner peripheral surface of the pipe-line, and while the state 
remains, the pipe liner bag is heated or otherwise processed to harden the 
hardenable resin impregnated therein, thereby lining the inner peripheral 
surface of the pipe-line with the hardened pipe liner bag, thus repairing 
the pipe-line. 
By the way, the pipe lining method described above can be applicable 
similarly to a branch pipe of a sewage pipe and the like joining a main 
pipe thereof, but the inventors of the present invention have proposed a 
branch pipe lining method for lining the branch pipe using a branch pipe 
liner bag having a flange formed at one end thereof. In the branch pipe 
lining method, while a flange of a branch pipe liner bag is bonded to the 
circumference of a branch pipe opening of a main pipe, the branch pipe 
liner bag is everted (i.e. turned inside out) into the branch pipe from 
the main pipe toward the ground surface by pressurized fluid to be bonded 
to the inner wall of the branch pipe, and while the state is being kept, 
the branch pipe liner bag is heated or otherwise processed to have a 
hardenable resin impregnated therein hardened. 
Therefore, if a main pipe is lined with a main pipe liner bag by the 
above-described method after a branch pipe is lined by the above-described 
branch pipe lining method, an opening of the branch pipe to the main pipe 
(a branch pipe opening) is blocked by the main pipe liner bag, thereby 
requiring a boring work to be done for the main pipe liner bag blocking 
the branch pipe opening. 
As a main pipe of a size in a diameter of 800 m/m or less is too narrow for 
a man to enter, it is necessary to operate by remote operation from the 
ground surface a piercing robot introduced into the main pipe to drive a 
cutter for piercing the main pipe liner bag blocking the branch pipe 
opening. 
However, piercing the main pipe liner bag by remotely operating the 
piercing robot requires expertise and skill, and a flange and other 
portions of the branch pipe liner bag may be damaged by the cutter, 
thereby causing a problem such as infiltration of the underground water 
into the main pipe from the damaged portions. More specifically, depending 
on how the branch pipe is connected with the main pipe, damage of the 
branch pipe liner bag may be unavoidable. 
OBJECTS AND SUMMARY OF THE INVENTION 
The present invention has been made in view of the problems mentioned 
above, and it is an object of the present invention to provide a branch 
pipe liner bag capable of reliably eliminating damage caused by a cutter. 
It is another object of the present invention to provide a pipe lining 
method capable of piercing a main pipe liner bag without damaging the 
branch pipe liner bag. 
To achieve the above objects, according to a first aspect of the present 
invention, there is provided a branch pipe liner bag with a flange formed 
at one end of the hardenable resin impregnated bag comprising a tubular 
resin-absorbent material impregnated with an unhardened liquid hardenable 
resin, which has a cylindrical anti-piercing protector mounted on or 
embedded adjacent to the flange. 
In one embodiment of the first aspect, the anti-piercing protector 
comprises metal, ceramic, metallic fiber, carbon fiber, or Kevlar fiber. 
In another embodiment of the first aspect, height of the anti-piercing 
protector is set at 3 mm or higher. 
In a further embodiment of the first aspect, the anti-piercing protector 
has a protrusion protruding to the inside of the main pipe, after the 
branch pipe is lined. 
In a yet further embodiment of the first aspect, the anti-piercing 
protector has a protrusion protruding toward the branch pipe, after the 
branch pipe is lined. 
In a still yet further embodiment of the first aspect, the tubular 
resin-absorbent material comprises unwoven fabric, one end thereof is 
folded, the folded portion is broadened out, the broadened-out portion is 
impregnated with a hardenable resin which is hardened to form a flange in 
a shape of arcuate curvature along the inner peripheral surface of the 
main pipe, the outer surface of the tubular resin-absorbent material is 
covered with a highly air-tight covering material, the tubular 
resin-absorbent material is impregnated with a hardenable resin, and the 
covering material is extended at least 0.5 mm toward the flange from the 
boundary of the tubular resin-absorbent material with the flange. 
According to a second aspect of the present invention, there is provided a 
pipe lining method comprising the steps of forming a flange at one end of 
a hardenable resin impregnated bag comprising a tubular resin-absorbent 
material impregnated with unhardened liquid hardenable resin, lining a 
branch pipe using a branch pipe liner bag having a cylindrical 
anti-piercing protector mounted on or embedded adjacent to the flange, 
lining a main pipe using a main pipe liner bag made of a tubular 
resin-absorbent material impregnated with an unhardened liquid hardenable 
resin, and piercing a portion of the main pipe liner bag blocking a branch 
pipe opening. 
Thus, according to the above-mentioned pipe lining method implemented using 
the branch pipe liner bag as above-described, as the branch pipe liner bag 
adjacent to the flange is protected by the anti-piercing protector after a 
branch pipe is lined, the branch pipe liner bag is immune from damage 
caused by a cutter in a piercing work thereafter with the main pipe liner 
bag, thereby eliminating a problem such as infiltration of the underground 
water into the main pipe from the damaged portion. 
The above and other objects, features, and advantages of the present 
invention will become apparent from the following detailed description of 
the preferred embodiments thereof when read in conjunction with the 
accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention will hereinafter be described in connection with 
several preferred embodiments thereof with reference to the accompanying 
drawings. 
FIG. 1 is a cross-sectional view of a branch pipe liner bag, and FIG. 2 is 
a cross-sectional view of an anti-piercing protector, according to the 
present invention. 
The branch pipe liner bag 1 as illustrated in FIG. 1 has a flange 1B formed 
by hardening an outwardly folded end of a hardenable resin impregnated bag 
1A, which comprises a tubular resin-absorbent material impregnated with an 
unhardened liquid hardenable resin, an entire outer surface of the 
hardenable resin impregnated bag 1A and a portion (inner peripheral 
surface) of a flange 1B linking an outer surface of the hardenable resin 
impregnated bag 1A which is covered with a highly air-tight plastic film 
2, and a cylindrical anti-piercing protector 3 which is mounted on an 
outer surface (downward surface of FIG. 1) of the flange 1B. Meanwhile, 
the end of the hardenable resin impregnated bag 1A of the branch pipe 
liner bag 1 is air-tightly sealed by the plastic film 2. Further, in the 
present embodiment, although the entire outer surface of the hardenable 
resin impregnated bag 1A and a portion (inner peripheral surface)of the 
flange 1B linking the outer surface of the hardenable resin impregnated 
bag 1A is covered by the highly air-tight plastic film 2, the plastic film 
2 is required to be extended at least 0.5 mm toward the side of the flange 
1B from the boundary of the hardenable resin impregnated bag 1A of the 
tubular resin-absorbent material with the flange 1B. 
The above-described tubular resin-absorbent material comprises unwoven 
fabric such as polyester, polypropylene, acrylic, or the like, and as 
unhardened liquid hardenable resin to be impregnated therein, 
thermosetting resin such as unsaturated polyester resin, epoxy resin, 
vinyl ester resin, or the like may be used. Further, the plastic film 2 is 
formed in a form of a single or multi-layered seamless tube by the 
inflation method, and as a material thereof, polyurethane, polyethylene, 
nylon, ethylene vinyl alcohol, admer, ionomer, vinyl chloride, or the like 
may be selected. The plastic film 2 is adhered to the entire outer surface 
of the resin-absorbent material of the hardenable resin impregnated bag 1A 
and the inner peripheral surface of the resin absorbent material of the 
flange 1B by heat welding, bonding, or coating. 
Further, the flange 1B of the branch pipe liner bag 1 comprises a tubular 
resin-absorbent material, one end thereof being outwardly folded and 
broadened out, and the broadened-out portion being impregnated with 
thermosetting resin such as unsaturated polyester resin, epoxy resin, 
vinyl ester resin, phenol resin, urethane resin, silicone resin, or the 
like, and the impregnated portion being hardened beforehand, and the 
flange 1B is formed in a curved shape of arcuate curvature substantially 
equivalent to the curvature of a main pipe 10 (refer FIG. 3) to be 
described later. 
In the meantime, the anti-piercing protector 3 comprises metal such as 
stainless steel (SUS) or the like, ceramic, metallic fiber, carbon fiber, 
or kevlar fiber, a flange 3a is formed in a shape of arcuate curvature 
along the shape of the flange 1B at a position in the intermediate height 
of the outer surface thereof, as illustrated in detail in FIG. 2, and a 
plurality of circular holes 3a-1 are bored on the flange 3a. Furthermore, 
the anti-piercing protector 3 has the flange 3a, abutted to the outer 
surface (downward surface of FIG. 1) of the flange 1B, and fastened to the 
outer surface of the flange 1B, as illustrated in FIG. 1, by bolts 4 
inserted through the flange 1B and the plurality of circular holes 3a-1 
and nuts 5 screwed into the bolts 4. At this time, a protrusion 3b (a 
portion protruding to the inside of the main pipe 10 after the branch pipe 
is lined) of h1 high located downward of the flange 3a of the 
anti-piercing protector 3 protrudes to the downward of the flange 1B, and 
a protrusion 3c (a portion protruding toward the branch pipe 11 after the 
branch pipe is lined) of h2 high located upward of the flange 3a partially 
covers to protect the outer surface of the pre-everting hardenable resin 
impregnated bag 1A. Meanwhile, the height H (=h1+h2) of the anti-piercing 
protector 3 is set at 0.5 mm or higher. 
Next, a pipe lining method according to the present invention will be 
described with reference to FIGS. 3 to 7. Meanwhile, FIGS. 3 to 7 are 
cross-sectional views illustrating the pipe lining method according to the 
present invention in sequence of the steps. 
In FIG. 3, a main pipe 10 is connected with a branch pipe 11 of a smaller 
diameter. In the pipe lining method according to the present invention, 
after the branch pipe is lined using the branch pipe liner bag 1, the main 
pipe 10 is lined using a main pipe liner bag 6 to be described later, and 
the portion of the main pipe liner bag 6 blocking a branch pipe opening is 
pierced at the last. 
To start with, lining of a branch pipe 11 is described. 
The branch pipe 11 is lined using a branch pipe liner bag 1, as illustrated 
in FIG. 1. The branch pipe liner bag is introduced into a main pipe 10 by 
a working robot (not shown), and in a state a flange 1B is bonded to the 
circumference of a branch pipe opening of the main pipe 10, as illustrated 
in FIG. 3, a hardenable resin impregnated bag 1A is everted into the 
branch pipe 11 from the side of the main pipe 10 toward the ground surface 
by pressurized fluid such as pressurized air or the like. 
When the hardenable resin impregnated bag 1A of the branch pipe liner bag 1 
is completely everted into the branch pipe 11 across an entire length 
thereof, while the hardenable resin impregnated bag 1A remains pressed 
against the inner wall of the branch pipe 11 by the pressurized fluid 
applied into the inside of the branch pipe liner bag 1, the hardenable 
resin impregnated bag 1A is heated to harden the thermosetting resin 
impregnated therein. By this process, the inner surface of the branch pipe 
11 is lined with the hardened branch pipe liner bag 1, and the branch pipe 
11 is repaired. 
Accordingly, when the branch pipe 11 has been lined, a protrusion 3b of an 
anti-piercing protector 3 mounted on the flange 1B of the branch pipe 
liner bag 1 protrudes to the inside of the main pipe 10, as illustrated in 
FIG. 3, and a protrusion 3c of the anti-piercing protector 3 partially 
covers to protect the inner peripheral surface of the flange 1B and a 
portion of the inner peripheral surface of the hardenable resin 
impregnated bag 1A continuing to the flange 1B. 
When the branch pipe 11 has been lined in the manner as described above, 
the main pipe 10 is subjected to lining. 
Namely, as illustrated in FIG. 4, a main pipe liner bag 6 is everted into 
the main pipe 10 by the pressurized fluid such as pressurized air or the 
like. The main pipe liner bag 6 is made of a resin-absorbent material, an 
outer surface thereof being covered with a highly air-tight plastic film 
7, impregnated with an unhardened liquid hardenable resin. Meanwhile, as 
for the plastic film 7, the tubular resin-absorbent material, and the 
liquid hardenable resin, a similar material as used for the branch pipe 
liner bag 1 can be used. 
Therefore, as illustrated in FIG. 5, when the main pipe liner bag 6 has 
been everted into the main pipe 10 across the entire length thereof, the 
main pipe liner bag 6 is heated by an arbitrary heat medium to harden the 
thermosetting resin impregnated therein, while the main pipe liner bag 6 
remains pressed against the inner wall of the main pipe 10 by the 
pressurized fluid applied into the inside of the main pipe liner bag 6. 
Thus, the inner peripheral surface of the main pipe 10 is lined with the 
hardened main pipe liner bag 6 to have the main pipe 10 repaired, and the 
flange 1B of the branch pipe 11 is integrally bonded with the main pipe 
liner bag 6. 
By the way, when the inner peripheral surface of the main pipe 10 is lined 
with the main pipe liner bag 6, the branch pipe opening of the main pipe 
10 (a portion of the branch pipe 11 opened to the main pipe 10) is blocked 
by the main pipe liner bag 6, and the portion of the main pipe liner bag 6 
blocking the branch pipe opening requires to be pierced to have the branch 
pipe 11 communicated with the main pipe 10. 
In other words, as illustrated in FIG. 6, when piercing the main pipe liner 
bag 6, a piercing robot 12 is introduced into the main pipe 10. The 
piercing robot 12 is hydraulically driven, and a head 12a thereof can 
advance and retreat in the direction indicated by an arrow a in FIG. 6, 
and rotate in the direction indicated by an arrow b therein. The piercing 
robot 12 is also connected with pulling ropes 13, 14, and has a monitoring 
TV camera 15 installed thereon. Further, the piercing robot 12 has a 
hydraulic cylinder 16 installed on the head 12a thereof, and a hydraulic 
motor 17 is supported by a rod 16a which is movable upward and downward in 
the direction of the hydraulic cylinder 16 as indicated by an arrow c. 
Furthermore, on a output shaft 17a of the hydraulic motor 17, a cutter 18 
of an outer diameter smaller than a caliber of the anti-piercing protector 
3 is installed. The cutter 18 has cutting-teeth formed on the upper and 
lower surfaces and the outer peripheral surface thereof, and at the center 
of the upper surface, a reamer 18a is mounted. 
Therefore, while respectively monitoring from the ground surface the inside 
of the main pipe 10 and the branch pipe 11 using the TV camera 15 provided 
on the piercing robot 12 and a TV camera 19 introduced into the branch 
pipe 11, the piercing robot 12 can be moved in the main pipe 10 by a 
pulling rope 13 or 14 pulled to locate the cutter 18 at a predetermined 
position. Thereafter, while the hydraulic motor 17 is driven to rotate and 
drive the cutter 18, if the hydraulic cylinder 16 is driven to move upward 
the hydraulic motor 17 and the cutter 18, the portion of the main pipe 
liner bag blocking the branch pipe opening (a part surrounded by the 
anti-piercing protector 3) is cut by the cutter 18. However, at this time, 
the inner periphery of the flange 1B of the branch pipe liner bag 1 and a 
portion of the inner peripheral surface of the hardenable resin 
impregnated bag 1A are covered and protected by the metallic anti-piercing 
protector 3, and therefore immune from possible damage caused by the 
cutter 18, thereby eliminating a trouble, such as infiltration of the 
underground water into the main pipe 10 from the damaged part, to arise. 
Now, if the main pipe liner bag 6 at the branch pipe opening is completely 
cut by the cutter 18 in the manner as described above, the branch pipe 11 
is, as illustrated in FIG. 7, opened to the main pipe 10 making both of 
the branch pipe 11 and the main pipe 10 communicated. 
In the meantime, if the caliber of the main pipe has a diameter larger than 
800 m/m enabling a man to enter thereinto, an anti-piercing protector 3 
may be mounted after the branch pipe 11 has been completely lined on a 
flange 1B of a branch pipe liner bag 1 from the side of a main pipe 10. 
Further, as illustrated in FIG. 8, if a plurality of the circular holes 8 
are bored on the flange 1B of the branch pipe liner bag 1, a liquid 
hardenable resin, seeped out from a main pipe liner bag 6 while the main 
pipe liner bag 6 is being hardened, flows into the circular holes 8 to 
harden, thereby the flange 1B of the branch pipe liner bag 1 and the main 
pipe liner bag 6 are more firmly bonded together to incorporate. 
In the meantime, in the branch pipe liner bag 1 described above, although 
the anti-piercing protector 3 is mounted on the flange 1B, the 
anti-piercing protector 3 may be embedded respectively adjacent to flanges 
1B' and 1B", as illustrated in FIGS. 9 and 10. Meanwhile, FIGS. 9 and 10 
are partial cross-sectional views respectively of branch pipe liner bags 
1' and 1" according to separate embodiments of the present invention. 
The branch pipe liner bag 1', as illustrated in FIG. 9, is composed of a 
double layer structure with a first layer 1A'-1 and a second layer 1A'-2 
of a tubular resin-absorbent material comprising unwoven fabric, and 
respective one ends of the layers 1A'-1 and 1A'-2 are outwardly folded and 
hardened to constitute a flange 1B'. Further, adjacent to the flange 1B', 
an anti-piercing protector 3' is sandwiched between the first layer 1A'-1 
and the second layer 1A'-2. Meanwhile, the inner peripheral surface of the 
first layer 1A'-1 and the outer peripheral surface of the second layer 
1A'-2 are covered respectively with highly air-tight plastic films 2'-1 
and 2'-2. 
Therefore, when manufacturing a branch pipe liner bag 1', one end of a 
first layer 1A'-1 is outwardly folded and broadened out, and over the 
broadened-out portion, an anti-piercing protector 3' is placed. Further, 
one end of a second layer 1A'-2 is outwardly folded and broadened out, and 
the broadened-out portion is placed over the anti-piercing protector 3'. 
Then, each broadened-out portion of respective layers 1A'-1 and 1A'-2 is 
impregnated with a hardenable resin, and by hardening the hardenable 
resin, the branch pipe liner bag 1' having a hardened flange 1B' at one 
end thereof is obtained, and the anti-piercing protector 3' is embedded 
adjacent to the flange 1B'. 
Also, in a branch pipe liner bag 1" as illustrated in FIG. 10, a protrusion 
1B"-1 is formed on an inner periphery of a flange 1B", and in the flange 
1B" having the protrusion 1B"-1 formed thereon and a hardenable resin 
impregnated bag 1A" continuing to the flange 1B", an anti-piercing 
protector 3" is embedded. Meanwhile, an inner periphery of the hardenable 
resin impregnated bag 1A" of the tubular resin-absorbent material and the 
flange 1B" is covered with a highly air-tight plastic film 2", and the 
plastic film 2 securely prevents pressurized fluid from being leaked from 
the boundary of the hardenable resin impregnated bag 1A" with the flange 
1B". 
As will be apparent from the foregoing description, according to the pipe 
lining method of the present invention implemented using the branch pipe 
liner bag according to the present invention, after the branch pipe is 
thus lined, the branch pipe liner bag adjacent to the flange is protected 
by the anti-piercing protector, thereby making the branch liner bag immune 
from damage caused thereafter by the cutter in piercing the main pipe 
liner bag, and a problem such as infiltration of the underground water 
into the main pipe from the damaged portion can be eliminated. 
While the present invention has been described in connection with its 
preferred embodiments, it is to be understood that various modifications 
will occur to those skilled in the art without departing from the spirit 
of the invention. The scope of the present invention is therefore to be 
determined solely by the appended claims.