JP2008232153A - Inner tube oscillation preventing structure of double piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inner tube oscillation preventing structure of double piping which can suppress an oscillation of inner tube when water hammer is generated by using no cushioning material. <P>SOLUTION: In a double piping 1 in which an inner tube 3 for water supply or hot-water supply is inserted in a sheath pipe 2, the sheath pipe 2 is characterized in that it can be processed in axial telescopic motion, in that an inner diameter is larger than an outer diameter of the inner tube 3 in a normal state in which external force is not axially applied, in that the inner diameter becomes smaller than that of normal state in a state of being axially contracted, in that sinuous pipe which can process in self holding a state of being contracted is used, in that a contraction section 2a, in which the sheath pipe is axially contracted, and its state is processed in self holding, is arranged, and in that an oscillation of the inner tube 3 is suppressed by this contraction section 2a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inner pipe steadying structure for a double pipe that prevents noise caused by a water hammer.

  In recent years, when pipes for water supply or hot water supply are laid in a building, the sheath pipe header method is widely used. In this construction method, a double pipe in which a resin inner pipe for water supply or hot water supply is inserted into a sheath pipe made of a corrugated pipe made of resin is used. When such a double pipe is laid in the building and used for water supply or hot water supply, the inner pipe will shake in the sheath due to water hammer (rapid increase in water pressure) that occurs when the faucet is suddenly closed. There is a problem that the sheath collides with the inner surface of the pipe and generates noise. In order to solve this problem, it is effective to interpose a buffer material between the sheath tube and the inner tube so that the inner tube does not collide with the sheath inner surface (Patent Documents 1 and 2).

Japanese Patent No. 2934722 JP 2005-147171 A

  However, interposing a cushioning material between the sheath tube and the inner tube not only increases the cost by the amount of the cushioning material, but it is also troublesome to draw the cushioning material into the sheath tube. In addition, if a cushioning material is interposed between the sheath tube and the inner tube, there is no clearance between the sheath tube and the inner tube, so that insertion becomes difficult when the inner tube is inserted into the sheath tube. Furthermore, when the inner pipe is pulled out and renewed, the buffer material is broken and clogged, and the inner pipe cannot be pulled out.

  In view of the above problems, an object of the present invention is to provide an inner pipe steadying structure for a double pipe that can suppress runout of the inner pipe when water hammer occurs without using a buffer material. .

  The double pipe inner pipe steadying structure according to the present invention is a double pipe in which an inner pipe for supplying water or hot water is inserted into a sheath pipe, and the sheath pipe can be expanded and contracted in the axial direction, and an external force is applied in the axial direction. In the normal state, the inner diameter is larger than the outer diameter of the inner tube, and in the axially contracted state, the inner diameter is smaller than the normal state, and a corrugated tube that can self-hold the contracted state is used. At least one of these is provided with a contraction portion in which the sheath tube is contracted in the axial direction to self-hold the state, and the contraction portion suppresses the shake of the inner tube.

  The double pipe inner pipe steadying structure according to the present invention is a double pipe in which an inner pipe for supplying water or hot water is inserted into a sheath pipe, and the sheath pipe can be expanded and contracted in the axial direction, and an external force is applied in the axial direction. Uses a corrugated tube that has an inner diameter that is larger than the outer diameter of the inner tube in the normal state that is not applied, an inner diameter that is smaller than that in the normal state when the tube is shrunk in the axial direction, and can self-hold the contracted state when heated in a contracted state. In addition, at least one portion of the sheath in the normal state is provided with a contracted portion that self-holds the contracted state by shrinking the sheath tube in the axial direction and heating, and the contracted portion suppresses the shake of the inner tube. May be used.

  In the inner pipe steadying structure of the double pipe according to the present invention, it is preferable that the inner peripheral surface of the contracted portion of the sheath pipe is brought into contact with the inner pipe.

  In the inner pipe steadying structure of the double pipe according to the present invention, it is preferable to fix the contracted portion of the sheath pipe to a structure such as a building wall or a floor by a fixing member.

  According to the present invention, by shrinking a part of the sheath tube, the inner diameter of the sheath tube is reduced and the inner tube is prevented from being shaken. Can be suppressed. Therefore, the cost can be reduced as much as the cushioning material is not required. Further, since the sheath tube can self-hold in the contracted state, there is no fear that the contracted portion extends in the axial direction (inner diameter increases), and the noise prevention effect can be stably maintained.

  Moreover, if the inner peripheral surface of the contracted portion of the sheath tube is brought into contact with the inner tube, it is possible to more reliably suppress the shake of the inner tube, and the noise prevention effect becomes more reliable.

  Moreover, if the shrinkage | contraction part of a sheath pipe is fixed to structures, such as a building wall and a floor, by a fixing member, the shake | fluctuation of the whole double piping can be suppressed and the noise prevention effect becomes still more reliable.

  FIG. 1 shows an embodiment of the present invention. The double pipe 1 is obtained by inserting an inner pipe 3 for supplying water or hot water into a sheath pipe 2. The sheath tube 2 is composed of a corrugated tube that can be expanded and contracted in the axial direction. In a normal state in which no external force is applied in the axial direction, the inner diameter is larger than the outer diameter of the inner tube 3, and in a contracted state in the axial direction, The inner diameter is reduced, and the compressed state can be held by itself. The inner pipe 3 is the same straight pipe as the conventional one. The sheath tube 2 is made of, for example, polyethylene, and the inner tube 3 is made of, for example, cross-linked polyethylene.

  The sheath tube 2 is laid in a normal state in which the sheath tube 2 is not stretched or contracted in the axial direction. However, if a contracted portion 2a in which the sheath tube is contracted in the axial direction is provided in a part thereof, the inner diameter of the contracted portion 2a is reduced. Thus, the radial movement of the inner tube 3 is limited, and the vibration of the inner tube 3 can be suppressed (noise can be prevented). Further, when the sheath 2 is contracted in the axial direction, the contracted portion 2a can be held in its contracted state, so that the contracted portion 2a is not likely to extend in the axial direction (inner diameter increases), and the noise prevention effect is stabilized. Can be maintained.

  In order to be able to self-hold the sheath 2 in a contracted state, for example, as shown in FIG. 1, the waveform of the corrugated tube in a normal state where no external force is applied in the axial direction is made into a triangular waveform, It is preferable that the inclined wall p on one side is shorter than the inclined wall q on the opposite side and the inclination is tight. In this way, when the sheath 2 is contracted, the inclined wall p on one side enters the inside of the inclined wall q on the opposite side, and the shape is stabilized in that state (it is difficult to return to the original state), so the contracted state Can self-hold. In addition, the structure for enabling the sheath 2 to be held in a contracted state is not limited to the structure shown in FIG.

  The sheath 2 is preferably formed such that the inner diameter of the contracted portion is slightly smaller than the outer diameter of the inner tube when the sheath 2 is contracted in the axial direction without inserting the inner tube. If it does in this way, since the inner peripheral surface of contraction part 2a will be in the state which contacts the outer peripheral surface of inner pipe 3 in the perimeter, it can prevent the movement of the inner pipe 3 in the diameter direction reliably, and when the water hammer occurs It is possible to reliably prevent noise caused by the vibration of 3.

  FIG. 2 shows another embodiment of the present invention. In this embodiment, the sheath 2 of the double pipe 1 is extendable in the axial direction, and in a normal state where no external force is applied in the axial direction, the inner diameter is larger than the outer diameter of the inner tube 3 and is contracted in the axial direction. Then, it is the same as Embodiment 1 in the point comprised by the corrugated tube whose inside diameter becomes smaller than a normal state. The difference from the first embodiment is that a part of the sheath 2 is heated in a contracted state, and the contracted state is held by itself.

  Since the sheath tube 2 is formed of a thermoplastic resin such as polyethylene, when the waveform is a normal waveform close to a sine wave or a rectangular wave, it will return to its original state when the force of contraction is released even if it is contracted in the axial direction. However, when heated, the strain in the material generated by shrinking is relieved, so that the material is solidified when it is returned to room temperature thereafter, and the shrunken state can be self-maintained. Therefore, after laying the sheath tube 2 in a normal state and pulling the inner tube 3 into the sheath tube 2, the required portion of the sheath tube 2 is contracted in the axial direction and the portion is heated by the cylindrical heater 4 or the like. Since the portion 2a can be held in a contracted state, the contraction of the inner tube 3 can be suppressed by the contraction portion 2a.

  FIG. 3 shows a use state of the inner tube steadying structure according to the present invention. In the figure, 11 is a slab under the floor of a building, 12 is a fabric foundation, 13 is a floor, 14 is a hollow wall, 15 is a flush toilet, 16 is a water tank, 17 is a faucet box, 1 is a double pipe, 2 is a sheath pipe, 2a is a contraction portion of the sheath 2; The contracted portion 2 a is fixed to the underfloor slab 11, the fabric foundation 12, and the like by a saddle (fixing member) 18.

Sectional drawing which shows one Embodiment of the inner pipe steadying structure of the double piping which concerns on this invention. Sectional drawing which shows other embodiment of the inner pipe steadying structure of the double piping which concerns on this invention. Explanatory drawing which shows the use condition of the inner pipe steadying structure of the double piping which concerns on this invention.

Explanation of symbols

1: double pipe 2: sheath pipe 2a: contraction part 3: inner pipe 4: cylindrical heater 17: faucet box 18: saddle (fixing member)

Claims (4)

  In a double pipe in which an inner pipe for supplying water or hot water is inserted into the sheath pipe, the inner diameter is larger than the outer diameter of the inner pipe in a normal state where the sheath pipe can be expanded and contracted in the axial direction and no external force is applied in the axial direction. In the axially contracted state, the inner diameter is smaller than that in the normal state, and a corrugated tube that can self-hold the contracted state is used, and the sheath tube is contracted in the axial direction in at least one position of the normal state sheath An inner pipe steadying structure for a double pipe, characterized in that a shrinking part is provided for self-holding the inner pipe and the inner pipe is prevented from shaking at the shrinking part.   In a double pipe in which an inner pipe for supplying water or hot water is inserted into the sheath pipe, the inner diameter is larger than the outer diameter of the inner pipe in a normal state where the sheath pipe can be expanded and contracted in the axial direction and no external force is applied in the axial direction. When the tube is shrunk in the axial direction, the inner diameter is smaller than that in the normal state, and when heated in the contracted state, a corrugated tube that can self-hold the shrunk state is used. An inner pipe steadying structure for a double pipe, characterized by providing a contracted portion that self-holds the contracted state by shrinking in the direction and heating, and suppressing the shake of the inner pipe at the contracted portion.   The inner pipe steadying structure for a double pipe according to claim 1 or 2, wherein the inner peripheral surface of the contracted portion of the sheath pipe is brought into contact with the inner pipe.   4. The double pipe inner pipe steadying structure according to claim 1, wherein the contracted portion of the sheath pipe is fixed to a structure such as a wall or floor of a building by a fixing member.

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