Patent Description:
When repairing or replacing a fluid tube such as a water pipe or the like buried in the ground, fluid inside the fluid tube in an operation zone needs to be shut down before cutting the fluid tube.

Patent Literature <NUM> discloses a blocking device that lowers a shaft member after inserting a guide member inside a water supply tube, introduces a bag inside the water supply tube through an opening at a lower end of the guide member, and expand the bag in the water supply tube to shut down the water supply.

However, in a case where pressure fluctuation occurs in the water supply tube in a state in which the water supply tube is blocked with the bag, the blocking device described in Patent Literature <NUM> has a concern that the bag may move within the water supply tube and collide with the guide member thus deforming the guide member, causing the guide member to be non-storable.

Thus, a technical problem to be solved arises to provide a blocking device and method capable of safely blocking a fluid tube, and an object of the present invention is to solve such a problem.

In order to achieve the above object, a blocking device according to the present invention introduces a bag into a fluid tube, and expands the bag by pressure of fluid to block the inside of the fluid tube, the blocking device including a cylinder connectable to the fluid tube, a guide pipe provided to be movable forward and backward in an axial direction of the cylinder in the cylinder and formed with a notch for passing the bag at a tip end, a slide tube inserted into the guide pipe and provided to be movable forward and backward in the axial direction, and having a tip end portion connected to the bag and a basal end portion connected to a fluid source for expanding the bag, and a safety mechanism that allows supply of fluid to the slide tube only in a state in which the guide pipe is withdrawn from the fluid tube, where the bag is expanded in a state in which the guide pipe is withdrawn from the fluid tube.

According to this configuration, the guide pipe and the slide tube are lowered to the fluid tube in this order, the bag is introduced into the fluid tube through the notch, and thereafter, only the guide pipe is raised and the bag is expanded to block the inside of the fluid tube, so that the bag that blocks the fluid tube by pressure fluctuation in the fluid tube can be suppressed from colliding with the tip end of the guide pipe and deforming the guide pipe. Furthermore, the safety mechanism can suppress expansion of the bag in a state in which the guide pipe is retained in the fluid tube by allowing the supply of fluid to the slide tube only in a state in which the guide pipe is withdrawn from the fluid tube.

In addition, in order to achieve the above object, a blocking method according to the present invention is a blocking method using the blocking device described above, the method including steps of connecting the cylinder to the fluid tube, introducing a tip end of the guide pipe into the fluid tube, advancing the cylinder toward the fluid tube and introducing the bag into the fluid tube through the notch, withdrawing the guide pipe from the fluid tube before expanding the bag, and expanding the bag to block the inside of the fluid tube.

According to such a configuration, the guide pipe and the slide tube are lowered to the fluid tube in this order, the bag is introduced into the fluid tube through the notch, and thereafter, the bag is expanded to block the inside of the fluid tube in a state in which only the guide pipe is raised, so that the bag that blocks the fluid tube by pressure fluctuation in the fluid tube can be suppressed from colliding with the tip end of the guide pipe and deforming the guide pipe.

According to the present invention, the bag that blocks the fluid tube by pressure fluctuation in the fluid tube can be suppressed from colliding with the tip end of the guide pipe and deforming the guide pipe.

Hereinafter, a blocking device <NUM> according to one embodiment of the present invention will be described based on the drawings.

Note that the drawings may be exaggerated by enlarging the characteristic portion to facilitate the understanding of the feature, and the dimensional ratio or the like of the configuring elements may not necessarily be the same as the actual dimensional ratio or the like. Furthermore, in the cross-sectional view, hatching of some configuring elements may be omitted to facilitate the understanding of a cross-sectional structure of the configuring element. Note that in the present example, the words "upper" and "lower" correspond to the upper side and the lower side in the up-down direction.

<FIG> are partially cutout perspective views illustrating a blocking device <NUM>. <FIG> is a front view illustrating the blocking device <NUM>, and <FIG> is a cross-sectional view taken along line A-A of <FIG>. The blocking device <NUM> is connected to a position corresponding to a perforation <NUM> of a fluid tube <NUM> by way of a stopper saddle <NUM>. Note that hereinafter, a case in which the water supply flows through the fluid tube <NUM> will be described by way of example, but the fluid flowing through the fluid tube <NUM> is not limited to water supply, and for example, may be liquid such as industrial water, agricultural water, sewage, or the like, gas, or mixture of liquid and gas.

The fluid tube <NUM> is formed to have a substantially circular cross-sectional shape, and the material thereof is metal, concrete, vinyl chloride, polyethylene, polyolefin, or the like. Alternatively, the inner peripheral surface of the fluid tube <NUM> may be covered with epoxy resin, mortar or the like.

The stopper saddle <NUM> presents a substantially cylindrical shape by combining an upper saddle portion 3a and a lower saddle portion 3b so as to face each other, each of which are formed to a substantially half-cylindrical shape.

A side flange 4a is provided on both ends in a width direction of the upper saddle portion 3a. Furthermore, a side flange 4b is provided on both ends in the width direction of the lower saddle portion 3b. The side flanges 4a, 4b are formed with a bolt hole (not shown) through which a bolt <NUM> is inserted. The bolt <NUM> is screw fitted with a nut 5a while being inserted to the bolt hole of the side flanges 4a, 4b, thereby integrally fixing the upper saddle portion 3a and the lower saddle portion 3b.

A central flange <NUM> is provided at the middle of the upper saddle portion 3a. The central flange <NUM> is provided in a standing manner from the upper saddle portion 3a in an up-down direction orthogonal to the width direction. The central flange <NUM> is formed to have substantially the same diameter along the up-down direction.

The central flange <NUM> is formed with an attachment hole <NUM> that passes through the upper saddle portion 3a in the up-down direction. The attachment hole <NUM> communicates the inner side and the outer side of the upper saddle portion 3a. The attachment hole <NUM> is arranged at a position corresponding to the perforation <NUM>.

The inner peripheral surface of the upper saddle portion 3a is formed to curve along the outer periphery of the fluid tube <NUM>. A seal groove <NUM> engraved on substantially a concentric circle with the attachment hole <NUM> corresponding to the perforation <NUM> is provided on the inner peripheral surface of the upper saddle portion 3a. An O-ring <NUM> is fitted-into the seal groove <NUM>. The O-ring <NUM> suppresses water supply from leaking out from between the upper saddle portion 3a and the fluid tube <NUM>.

The blocking device <NUM> includes a cylinder <NUM>, a guide pipe <NUM>, and a slide tube <NUM>.

The cylinder <NUM> is formed to a substantially cylindrical shape, where an opening 20a is formed at the lower part and a lid 20b is formed at the upper part. The lower end of the cylinder <NUM> is connected to the stopper saddle <NUM> by way of a ball valve <NUM>, and the opening 20a of the cylinder <NUM> is arranged in correspondence with the perforation <NUM>. The cylinder <NUM> has a water tight structure except for the opening 20a. The cylinder <NUM> and the fluid tube <NUM> communicate when the ball valve <NUM> is opened.

The guide pipe <NUM> is accommodated in the cylinder <NUM>, and is provided to be movable forward and backward (rise and lower) in an axial direction L in the cylinder <NUM>. The guide pipe <NUM> is formed to a substantially cylindrical shape.

Two handles <NUM> are provided in a standing manner on the peripheral surface of the guide pipe <NUM>. The handle <NUM> is drawn to the outside of the cylinder <NUM> through a slit <NUM> formed on the peripheral surface of the cylinder <NUM>.

A half-divided notch <NUM> is formed at a tip end of the guide pipe <NUM>. The length of the notch <NUM> can be arbitrarily set in a range of passing the bag <NUM>, and is set to be substantially the same as or shorter than the diameter of the fluid tube <NUM>. The notch <NUM> is arranged to face the downstream side (left direction in the plane of drawing of <FIG>) of the flow of water supply in the fluid tube <NUM> when introduced into the fluid tube <NUM>. Note that the shape of the notch <NUM> is not limited to a substantially perpendicular shape, and may be any shape as long as it does not interfere with the slide tube <NUM> when withdrawing the guide pipe <NUM> from the fluid tube <NUM>, as will be described later.

The guide pipe <NUM> is provided with a joint <NUM> and a chain <NUM> that configure a safety mechanism. The joint <NUM> is connectable to a suction port <NUM>, described later. The chain <NUM> has one end fastened to the handle <NUM> and the other end attached to the joint <NUM>. The length of the chain <NUM> is set such that the joint <NUM> does not reach the suction port <NUM> when the handle <NUM> is located on the lower side, and the joint <NUM> reaches the suction port <NUM> when the handle <NUM> is located on the upper side.

The slide tube <NUM> is inserted into the guide pipe <NUM>. Two handles <NUM> are provided in a standing manner at the upper part of the slide tube <NUM>. The slide tube <NUM> is formed to a substantially cylindrical shape, and is interiorly provided with a compressed air line 40a. The lower end of the compressed air line 40a is connected to the bag <NUM> by way of a hose <NUM>, and the upper end of the compressed air line 40a is connected to a fluid source <NUM> by way of the suction port <NUM> and the joint <NUM>. The slide tube <NUM> is provided to be movable forward and backward (rise and lower) in an axial direction A in the guide pipe <NUM>. Note that the guide pipe <NUM> and the slide tube <NUM> are independently movable.

The slide tube <NUM> is connected to the bag <NUM> by way of a flexible hose <NUM>. The hose <NUM> is a rubber tube or the like of a predetermined length having flexibility.

Compressed air supplied from the fluid source <NUM> is fed into the bag <NUM> through the compressed air line 40a and the hose <NUM>. Note that the fluid for expanding the bag <NUM> is not limited to compressed air.

Next, a procedure for blocking the inside of the fluid tube <NUM> will be described based on the drawings.

First, as illustrated in <FIG>, the cylinder <NUM> is attached to the fluid tube <NUM> through the stopper saddle <NUM>. The bag <NUM> is accommodated in the guide pipe <NUM> in a compressed state.

Next, as illustrated in <FIG>, the guide pipe <NUM> is lowered in a state in which the slide tube <NUM> is made stationary. Specifically, when the operator grips the handle <NUM> and lowers the guide pipe <NUM>, the tip end of the guide pipe <NUM> is introduced into the fluid tube <NUM>. At this time, the guide pipe <NUM> is preferably lowered until the peripheral surface of the guide pipe <NUM> reaches the fluid tube <NUM>. Thus, burr, and the like attached to the inner peripheral surface of the perforation <NUM> can be suppressed from damaging the bag <NUM> at the time of inserting the bag <NUM>.

Next, as illustrated in <FIG>, the bag <NUM> is introduced inside the fluid tube <NUM>. Specifically, when the operator grips the handle <NUM> and lowers the slide tube <NUM>, the bag <NUM> is introduced into the fluid tube <NUM> through the notch <NUM>. Note that as the water supply flows from the upstream side toward the downstream side and the tip end of the guide pipe <NUM> is located on the upstream side of the water supply with respect to the bag <NUM> in the fluid tube <NUM>, the hose <NUM> is curved and the bag <NUM> is introduced to the downstream side of the fluid tube <NUM>. Furthermore, in a case where the notch <NUM> is formed to incline toward the downstream side of the fluid tube <NUM>, the bag <NUM> can be smoothly introduced into the fluid tube <NUM>.

Next, as illustrated in <FIG>, the bag <NUM> is expanded to block the inside of the fluid tube <NUM> in a state in which the guide pipe <NUM> is withdrawn from the fluid tube <NUM>.

Specifically, first, when the operator grips the handle <NUM> and raises the guide pipe <NUM>, the tip end of the guide pipe <NUM> is withdrawn from the fluid tube <NUM> in a state in which the slide tube <NUM> is lowered.

Next, the fluid source <NUM> and the suction port <NUM> are connected by way of the joint <NUM>, the fluid source <NUM> is activated, the compressed air is supplied to the bag <NUM> through the compressed air line 40a and the hose <NUM>, and the bag <NUM> is expanded to block the fluid tube <NUM> (stop water). Thus, even in a case where the bag <NUM> moves toward the upstream side by pressure fluctuation in the fluid tube <NUM>, the bag <NUM> can be avoided from coming into contact with the guide pipe <NUM>.

Thus, the blocking device <NUM> according to the present embodiment is a blocking device <NUM> that introduces the bag <NUM> into the fluid tube <NUM>, and expands the bag <NUM> by pressure of fluid to block the inside of the fluid tube <NUM>, the blocking device including a cylinder <NUM> connectable to the fluid tube <NUM>; a guide pipe <NUM> provided to be movable forward and backward in the axial direction A of the cylinder <NUM> in the cylinder <NUM> and formed with a notch <NUM> for passing the bag <NUM> at the tip end; a slide tube <NUM> inserted into the guide pipe <NUM> and provided to be movable forward and backward in the axial direction A and having a tip end portion connected to the bag <NUM> and a basal end portion connected to a fluid source <NUM> for expanding the bag <NUM>; and a safety mechanism for allowing supply of fluid to the slide tube <NUM> only in a state in which the guide pipe <NUM> is withdrawn from the fluid tube <NUM>; where the bag <NUM> is expanded in a state in which the guide pipe <NUM> is withdrawn from the fluid tube <NUM>.

According to such a configuration, the guide pipe <NUM> and the slide tube <NUM> are lowered to the fluid tube <NUM> in this order, the bag <NUM> is introduced into the fluid tube <NUM> through the notch <NUM>, and thereafter, the bag <NUM> is expanded to block the inside of the fluid tube <NUM> in a state in which only the guide pipe <NUM> is withdrawn from the fluid tube <NUM>, so that the bag <NUM> that blocks the fluid tube <NUM> by pressure fluctuation in the fluid tube <NUM> can be suppressed from colliding with the tip end of the guide pipe <NUM> and deforming the guide pipe <NUM>. Furthermore, the safety mechanism can suppress expansion of the bag <NUM> in a state in which the guide pipe <NUM> is retained in the fluid tube <NUM> by allowing the supply of fluid to the slide tube <NUM> only in a state in which the guide pipe <NUM> is withdrawn from the fluid tube <NUM>.

Furthermore, the blocking device <NUM> according to the present embodiment has a configuration in which the safety mechanism includes a joint <NUM> capable of connecting the fluid source <NUM> and the suction port <NUM> of the slide tube <NUM>, and a chain <NUM> for connecting the joint <NUM> and the handle <NUM>, where the length of the chain <NUM> is set to be substantially equal to the distance of the handle <NUM> and the suction port <NUM> in a state in which the guide pipe <NUM> is withdrawn from the fluid tube <NUM>.

According to such a configuration, if not a state in which the guide pipe <NUM> is withdrawn from the fluid tube <NUM>, the fluid source <NUM> cannot be connected to the suction port <NUM> through the joint <NUM> and the bag <NUM> cannot be expanded, and thus the bag <NUM> can be reliably suppressed from being expanded in a state in which the guide pipe <NUM> is retained in the fluid tube <NUM>.

A blocking method using the blocking device <NUM> according to the present embodiment has a configuration including a step of connecting a cylinder <NUM> to a fluid tube <NUM>, a step of introducing a tip end of the guide pipe <NUM> to the fluid tube <NUM>, a step of lowering the cylinder <NUM> toward the fluid tube <NUM> and introducing the bag <NUM> to the fluid tube <NUM> through a notch <NUM>, a step of withdrawing the guide pipe <NUM> from the fluid tube <NUM> before expanding the bag <NUM>, and a step of expanding the bag <NUM> to block the inside of the fluid tube <NUM>.

According to such a configuration, the guide pipe <NUM> and the slide tube <NUM> are lowered to the fluid tube <NUM> in this order, the bag <NUM> is introduced into the fluid tube <NUM> through the notch <NUM>, and thereafter, the bag <NUM> is expanded to block the inside of the fluid tube <NUM> in a state in which only the guide pipe <NUM> is withdrawn from the fluid tube <NUM>, so that the bag <NUM> that blocks the fluid tube <NUM> by pressure fluctuation in the fluid tube <NUM> can be suppressed from colliding with a tip end of the guide pipe <NUM> and deforming the guide pipe <NUM>.

In addition, other than the description made above, various modifications can be made within a scope not deviating from the invention as defined in the appended claims.

Claim 1:
A blocking device (<NUM>) configured to introduce a bag (<NUM>) into a fluid tube (<NUM>), and to expand the bag by pressure of fluid to block the inside of the fluid tube, the blocking device comprising
a cylinder (<NUM>) connectable to the fluid tube;
a guide pipe (<NUM>) provided to be movable forward and backward in an axial direction of the cylinder in the cylinder and formed with a notch (<NUM>) for passing the bag at a tip end;
a slide tube (<NUM>) inserted into the guide pipe (<NUM>) and provided to be movable forward and backward in the axial direction, and having a tip end portion connected to the bag (<NUM>) and a basal end portion configured to be connected to a fluid source (<NUM>) for expanding the bag (<NUM>) ; characterized in that the blocking device further comprises
a safety mechanism that allows supply of fluid to the slide tube (<NUM>) only in a state in which the guide pipe (<NUM>) is withdrawn from the fluid tube; wherein
the bag (<NUM>) is configured to be expanded in a state in which the guide pipe (<NUM>) is withdrawn from the fluid tube.