JP2012000043A - Stretchable spraying rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stretchable spraying rod whose inner tube does not come out from its outer tube without depending on the tightening condition of a tightening cap after the inner tube and the outer tube have once been fixed by manipulating the tightening cap.SOLUTION: The stretchable spraying rod 1 comprises the outer tube 3A having a male screw unit 14 on one end, the inner tube 10 whose other end is received in the outer tube 3A to be freely movable toward the tube center C, a clamp ring 11 freely engaged to the outer peripheral surface of the inner tube 10 and the tightening cap 8 freely engaged to the outer peripheral surface of the inner tube 10. The inner tube 10 and the outer tube 3A are constituted to be fixed so as to bring the rod length to be variable by screwing the male screw unit 14 of the outer tube 3A with a female screw unit 28 made on the inner peripheral surface of the tightening cap 8 to pressurize the clamp ring 11 to contact the inner tube 10. A movable cylindrical body 12 mounted to be freely movable toward the tube center C is equipped between the inner tube 10 and the outer tube 3A, and the movable cylindrical body 12 is constituted to bring the clamp ring 11 to contact the inner tube 10 through pressurization by receiving the liquid pressure from a connected part in the side of a chemical liquid to pressurize the clamp ring 11 to the side of a spray nozzle.

Description

  The present invention relates to an expansion / contraction spreader that accommodates an inner tube in an outer tube so as to be movable in the direction of the tube center and fixes the inner tube in a variable length.

  Conventionally, as this type of elongate spreader with variable cocoon length, for example, the one described in Patent Document 1 below is known. As shown in FIG. 13, the expansion / contraction sprinkler 51 described in Document 1 has an outer tube 52 having a male threaded portion 56 at one end and the other end 60 connected to a chemical injection pump and the like, and a spray nozzle connected to one end 59. The other end 61 side is accommodated in the outer tube 52 so as to be movable in the tube center direction, the clamp ring 55 is loosely fitted on the outer peripheral surface of the inner tube 53, and is loosely fitted on the outer peripheral surface of the inner tube 52. And a fastening cap 54 with a female thread portion 57 disposed outside the clamp ring 55 and a water sealing O-ring 58 fitted on the outer peripheral surface of the other end of the inner tube 52. It is. The expansion / contraction spreading rod 51 is adjusted by inserting and removing the inner tube 53 from the outer tube 52 to a desired length, and then screwing the female screw portion 57 of the fastening cap 54 and the male screw portion 56 of the outer tube 52 together. By doing so, the diameter of the clamp ring 55 is reduced, and the inner tube 53 and the outer tube 52 are fixed by being pressed against the inner tube 53.

Japanese Utility Model Publication No. 5-37367

In the expansion / contraction sprinkler described in Document 1, when the tightening cap 54 is tightened very firmly, the inner tube 53 is tightened by the pressure contact force of the clamp ring 55, and the inner tube 53 and the outer tube 52 are almost fixed. The However, the tightening force of the tightening cap 54 often varies depending on the person. In addition, when the expansion and contraction of the heel must be repeated during the spraying operation, the tightening degree may change every time the tightening cap 54 is tightened.
The liquid pressure of the chemical liquid (in the direction of arrow F) sent from a chemical liquid injection pump or the like is also applied to the end surface of the other end 61 of the inner tube 53, and is high when the tightening of the tightening cap 54 is weak. The inner pipe 53 may unexpectedly come out to the one end 59 side due to the hydraulic pressure. In this way, when the inner pipe 53 comes out, the eaves lengthens, so that, for example, there is a problem that it becomes difficult to operate unexpectedly during the spraying operation.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide an expansion / contraction sprayer in which the inner tube does not come out of the outer tube regardless of the tightening condition of the tightening cap. To do.

  In order to achieve the above-mentioned object, the expansion / contraction sprinkler according to the present invention has an outer tube having a male screw portion at one end and a connecting portion on the chemical injection side at the other end, and a connecting portion on the spray nozzle side at one end. The other end side of the inner tube is accommodated in the outer tube so as to be movable in the direction of the center of the tube, the clamp ring is loosely fitted on the outer peripheral surface of the inner tube, The clamp ring is press-contacted to the inner tube by screwing the female thread portion provided on the inner peripheral surface of the tightening cap and the male thread portion of the outer tube. In a telescopic sprayer configured to fix the tube and the outer tube in a variable length, a movable cylinder that is mounted on the side of the clamp ring with a chemical solution and is movable between the inner tube and the outer tube. And the movable cylinder receives the hydraulic pressure from the chemical injection side connecting portion and It is the structure for pressing the pressing and the tube pulling the spray nozzle side.

Further, in the above configuration, the inner peripheral surface of the tightening cap on the spray nozzle side is formed as an inner tapered surface that is reduced in diameter toward the spray nozzle side, and the outer peripheral surface of the clamp ring on the spray nozzle side is on the spray nozzle side. It is formed as an outer tapered surface that is reduced in diameter and can be inserted into the inner tapered surface of the tightening cap.
Is.

  Further, in the above configuration, the clamp ring and the movable cylinder are integrally formed, and the end surface on the other end side of the movable cylinder is formed as a pressure receiving surface substantially orthogonal to the tube core.

  In each configuration described above, the inner peripheral surface on the spray nozzle side of the movable cylinder is formed as an inner tapered surface that expands toward the spray nozzle side, and the outer peripheral surface on the chemical liquid injection side of the clamp ring is the chemical liquid injection It is formed as an outer tapered surface that is reduced in diameter toward the side and can be inserted into the inner tapered surface of the movable cylinder.

  According to the expansion / contraction spreader according to the present invention, when the tightening cap is operated and tightened, the inner tube and the outer tube are firmly fixed. On the other hand, since it has a movable cylinder that is mounted on the side of the clamp ring that is inserted into the chemical solution and is movable between the inner tube and the outer tube in the direction of the tube center, even if the cap is loose, the chemical solution Upon receiving the hydraulic pressure from the press-fitting side, the movable cylinder presses the clamp ring toward the spray nozzle and presses the inner tube. Thereby, the inner tube can be reliably fixed to the outer tube. As a result, it is possible to provide an expansion / contraction sprayer in which the inner tube does not come out of the outer tube regardless of the tightening condition of the tightening cap.

  In addition, since a clamping cap having an inner tapered surface on the inner peripheral surface on the spray nozzle side and a clamp ring having an outer tapered surface on the outer peripheral surface on the spray nozzle side are both commercially available, these tightening caps are used. By simply adding a movable cylinder to the attached cap and clamp ring, the movable cylinder receives the hydraulic pressure from the chemical injection side connection part, and the movable cylinder presses the clamp ring toward the spray nozzle and presses the inner tube, It can be provided inexpensively and easily.

  In the above configuration, the clamp ring and the movable cylinder are integrally formed, and the end surface on the other end side of the movable cylinder is formed as a pressure receiving surface that is substantially orthogonal to the tube core. Therefore, it can be provided more inexpensively and easily.

  And even if it has a movable cylinder having an inner tapered surface on the inner peripheral surface on the spray nozzle side and a clamp ring having an outer tapered surface on the outer peripheral surface on the chemical liquid injection side, the liquid pressure from the chemical liquid injection side connecting portion is reduced. It is possible to provide a configuration in which the movable cylindrical body presses the clamp ring toward the spray nozzle and presses against the inner tube. Combining such a configuration with the above-described configuration including a clamping cap having an inner tapered surface on the inner peripheral surface on the spray nozzle side, and a clamp ring having an outer tapered surface on the outer peripheral surface on the spray nozzle side, Can be firmly pressed against the inner tube to more firmly fix the inner tube and the outer tube.

It is an external view of the expansion-contraction spreader which concerns on one Embodiment of this invention. It is the side view which extended the inner pipe | tube of the said expansion-contraction spreading bowl. It is a sectional side view which shows the principal part of the said expansion-contraction spreading bowl. It is the fragmentary perspective view which removed the fastening cap of the said expansion-contraction spreader from the outer tube | pipe. It is an expansion perspective view which shows the one end part vicinity of the outer tube | pipe of the said expansion-contraction spreader. It is an expansion perspective view which shows the movable cylinder of the said expansion-contraction spreader. It is an expansion perspective view which shows the clamp ring of the said expansion-contraction spreading bowl. It is a sectional side view which shows the principal part when the fastening cap is loosened in the said expansion-contraction spreader. It is a sectional side view which shows the principal part of the expansion-contraction spreader which concerns on other embodiment of this invention. It is a sectional side view which shows the principal part of the expansion-contraction spreader which concerns on other embodiment of this invention. It is a front view of the expansion-contraction spreader which concerns on another embodiment of this invention. It is the front view which extended the inner pipe | tube of the said another expansion-contraction spreading basket. It is a sectional side view which shows the conventional expansion-contraction spreader.

Embodiments of the present invention will be described with reference to the drawings. The embodiment described below is merely an example embodying the present invention, and does not limit the technical scope of the present invention. FIG. 1 is an external view of an expansion / contraction sprayer according to an embodiment of the present invention, FIG. 2 is a side view of the inner tube of the expansion / contraction sprayer, and FIG. 3 is a side sectional view showing a main part of the expansion / contraction sprayer. FIG. 4 is a partial perspective view in which the tightening cap of the telescopic spreader is removed from the outer tube.
In each figure, the telescopic spreading rod 1 according to this embodiment includes a main pipe 2, two sub pipes 3A and 3B branched from the main pipe 2, and a sub pipe 3A selected from the main pipe 2 in one operation. A switching lever 6 for switching the flow path to the sub-pipe 3B is provided. The sub pipes 3A and 3B are long straight pipe sections extending from the branch portions of the main pipe 2 to the respective ends. A spray nozzle 4F is attached to the spray nozzle side connecting portion 18 at one end of the sub pipe 3A. A spray nozzle 4E is attached to one end of the secondary pipe 3B, and spray nozzles 4C and 4D and spray nozzles 4A and 4B are attached to the middle of the pipe. A tubular handle 33 is connected to the other end of the main pipe 2, and the other end of the handle 33 is connected to a liquid feed pump (not shown) via a connecting hose 7.

  The above-described secondary pipe 3A (an example of the outer pipe: see also FIG. 5) is fitted with a tubular holder 9 at one end and is crimped, and at the other end is a chemical injection side that is a branch portion from the main pipe 2 It has a connection part 5. A male screw portion 14 is formed on the outer peripheral surface on one end side of the holder 9, and an inner end on one end side is formed with one end opening 13 having a stepped portion 19. One circumferential groove (not shown) is engraved on the inner peripheral surface of the holder 9 on the side closer to the chemical injection side connecting portion 5 than the step portion 19, and an O-ring 30 is attached to the circumferential groove. The O-ring 30 seals the space between the outer peripheral surface of the secondary pipe 3A and the inner peripheral surface of the holder 9 in a watertight manner.

  The inner tube 10 is provided with a spray nozzle side connection portion 18 to which the spray nozzle 4F is attached at one end. The other end side of the inner pipe 10 is accommodated in the secondary pipe 3A from the one end opening 13 of the holder 9 so as to be movable in the pipe core C direction. A cylindrical base 32 is attached to the other end opening of the inner tube 10. In this example, the secondary pipes 3A, 3B and the inner pipe 10 are made of stainless steel, but other than stainless steel can be made of brass, aluminum, synthetic resin, or the like. The tightening cap 8, the clamp ring 11, and the movable cylinder 12 are loosely fitted on the outer peripheral surface of the inner tube 10 in order from the spray nozzle 4 </ b> F side toward the chemical solution press-fitting side connection portion 5 side. Between the outer peripheral surface on the other end side of the inner pipe 10 and the inner peripheral surface of the secondary pipe 3A, a gap through which water can flow is provided. The gap and one end opening 13 communicate with each other through a liquid passage 29.

  The clamping cap 8 is formed to have a larger diameter than the outer diameters of the clamp ring 11 and the movable cylinder 12 and covers the periphery of the clamp ring 11 and the movable cylinder 12. The inner peripheral surface near the spray nozzle 4F in the tightening cap 8 is formed as an inner tapered surface 31 that decreases in diameter toward the spray nozzle 4F side. The fastening cap 8 is made of brass in this example, but aluminum or polyacetal resin can be used in addition to brass.

  The movable cylinder 12 (see also FIG. 6) is formed in a cylindrical shape having a cylinder opening 21 penetrating from one end to the other end. The movable cylinder 12 is mounted on the side of the clamp ring 11 where the chemical solution is inserted and between the inner pipe 10 and the sub pipe 3 </ b> A, that is, in the one end opening 13 of the holder 9 so as to be movable in the tube center C direction. The movable cylinder 12 is configured such that its rear surface 27 comes into contact with the step portion 19 of the one end opening 13 of the holder 9 and stops. The inner peripheral surface of the movable cylindrical body 12 near the spray nozzle 4F is formed as an inner tapered surface 22 whose diameter increases toward the spray nozzle 4F. Although the movable cylinder 12 is made of brass in this example, it can be made of aluminum, stainless steel, polyacetal resin, or the like other than brass.

  Two circumferential grooves (not shown) are engraved on the outer peripheral surface of the movable cylinder 12, O-rings 23 and 24 are fitted in these circumferential grooves, and 2 on the inner peripheral surface of the movable cylinder 12. Circumferential grooves (not shown) are engraved, and O-rings 25 and 26 are attached to these circular grooves. The holder 9 of the secondary pipe 3A and the movable cylinder 12 are slidably in contact with each other through the O-rings 23 and 24, and the movable cylinder 12 and the inner pipe 10 are in contact with each other through the O-rings 25 and 26. Are in watertight and slidable contact. The above-described O-rings 23, 24, 25, 26, and 30 are made of NBR in this example, but may be made of, for example, fluororubber other than NBR.

The clamp ring 11 (see also FIG. 7) is formed in a cylindrical shape having a cylindrical opening 20 penetrating from one end to the other end. The outer peripheral surface of the clamp ring 11 near the spray nozzle 4F (one end side) is formed as an outer tapered surface 16 having a diameter reduced toward the spray nozzle 4F side. The outer tapered surface 16 is formed in a size that can be inserted into the inner tapered surface 31 of the fastening cap 8. The outer peripheral surface of the clamp ring 11 near the chemical solution injection side connection portion 5 (the other end side) is formed as an outer tapered surface 17 whose diameter is reduced toward the chemical solution injection side connection portion 5. The outer tapered surface 17 is formed in a size that can be inserted into the inner tapered surface 22 of the movable cylinder 12. The clamp ring 11 is separated in the circumferential direction by a split groove 15 formed along the tube core C direction. The clamp ring 11 is made of brass in this example, but may be made of, for example, stainless steel, synthetic rubber, polypropylene, or polyacetal other than brass.
That is, the above-described configuration including the tightening cap 8, the clamp ring 11, the movable cylinder 12, and the holder 9 of the secondary pipe 3A fixes the inner pipe 10 to the secondary pipe 3A so that the inner pipe 10 can be inserted and removed. It is.

  Next, the operation of the telescopic spreading basket 1 configured as described above will be described. First, the tightening cap 8 is loosened so that the clamp ring 11 and the movable cylinder 12 can be freely moved in the direction of the tube core C. Subsequently, the inner pipe 10 is taken in and out of the sub pipe 3A, and is set to a desired length. Therefore, when the tightening cap 8 is turned and screwed toward the other end side (the direction opposite to the arrow F), the inner taper surface 31 of the tightening cap 8 contacts the outer taper surface 16 and the clamp ring 11 is moved to the other end side. Push. Subsequently, the outer tapered surface 17 of the clamp ring 11 hits the inner tapered surface 22 to push the movable cylinder 12 toward the other end side. Among them, the movable cylinder 12 is stopped by the rear surface 27 of the movable cylinder 12 coming into contact with the step portion 19 of the holder 9. When the tightening cap 8 is further tightened, the outer taper surface 16 is pressed by the inner taper surface 31 of the tightening cap 8, and one end side of the split groove 15 of the clamp ring 11 is narrowed to be reduced in diameter and brought into pressure contact with the inner tube 10. At the same time, the outer tapered surface 17 is pressed by the inner tapered surface 22 of the stopped movable cylinder 12, and the other end side of the split groove 15 of the clamp ring 11 is narrowed to be reduced in diameter and brought into pressure contact with the inner tube 10. As a result, the inner pipe 10 is firmly fixed to the sub pipe 3A. The state at this time is as shown in FIG.

  On the other hand, as shown in FIG. 8, when the screwing amount of the tightening cap 8 is small, that is, when the tightening of the tightening cap 8 is loose, the rear surface 27 of the movable cylinder 12 does not reach the step portion 19 or is weak. Since the contact is made by the contact force, the pressure contact force of the clamp ring 11 to the inner pipe 10 is small, and the inner pipe 10 is likely to advance from the secondary pipe 3A. Therefore, the liquid pressure of the chemical liquid entering the one end opening 13 through the liquid flow passage 29 from the chemical liquid injection side is applied to the rear surface 27 of the movable cylinder 12, and the movable cylinder 12 is pressed toward the spray nozzle side. Yes. Therefore, the inner taper surface 22 of the movable cylinder 12 presses the outer taper surface 17, the other end side of the clamp ring 11 is pressed against the inner tube 10, and the inner taper surface 31 of the clamping cap 8 presses the outer taper surface 16. One end of the clamp ring 11 is brought into pressure contact with the inner tube 10. Thereby, similarly to the state shown in FIG. 3, the inner pipe 10 and the sub pipe 3 </ b> A can be reliably fixed. As a result, it is possible to prevent a problem that the expansion / contraction spreading rod 1 set to a desired length is unexpectedly extended during use.

  In the above embodiment, the outer tapered surfaces 16 and 17 are formed on both the one end side and the other end side of the outer peripheral surface of the clamp ring 11, and the inner tapered surface 22 is formed on one end side of the inner peripheral surface of the movable cylinder 12. Is formed, and the inner tapered surface 31 is formed on one end side of the inner peripheral surface of the fastening cap 8. However, the present invention is not limited to this. For example, as shown in FIG. 9, the other end side has no outer taper surface and has a rear surface 35 along the tube radial direction and includes a split groove 15, and one end side has no inner taper surface in the tube radial direction. A thing provided with movable cylinder 12a which has front surface 36 which meets is also contained in the present invention. That is, the configuration including the tightening cap 8, the clamp ring 11a, the movable cylinder 12a, and the holder 9 of the secondary pipe 3A is a fixing portion 40a for fixing the inner pipe 10 to the secondary pipe 3A so that the inner pipe 10 can be taken in and out. . In FIG. 9, the same components as those shown in FIG. 1 to FIG.

  In this telescopic sprayer, the movable cylinder 12a that has received the liquid pressure from the chemical injection side on the rear surface 27 is pushed, and the front surface 36 of the movable cylinder 12a passes the rear surface 35 of the clamp ring 11a toward the spray nozzle (in the direction of arrow F). ). As a result, the outer taper surface 16 is pushed by the inner taper surface 31 of the tightening cap 8, and one end side of the clamp ring 11a is reduced in diameter to fix the inner tube 10 to the sub piping 3A. Since both the tightening cap 8 and the clamp ring 11a are available as general-purpose products, a configuration in which the clamp ring 11a is press-contacted to the inner tube 10 simply by adding a movable cylinder 12a to them is inexpensive. And can be provided easily.

Or although illustration is abbreviate | omitted, contrary to the above, the clamp ring which does not have an outer taper surface in one end side, has the front surface along a pipe radial direction, has the above-mentioned outer taper surface 17 in the other end side, and an inner peripheral surface. One having a fixed portion provided with a clamping cap having a rear surface for stopping the front surface of the clamp ring without an inner tapered surface on one end side, and a movable cylinder 12 having the inner tapered surface 22 described above on one end side, It is included in the present invention. In this telescopic spreading rod, the outer taper surface 17 of the clamp ring is pushed by the inner taper surface 22 of the movable cylinder 12, and the other end side of the clamp ring is reduced in diameter to fix the inner tube 10 to the sub piping 3A.
In the above description, the secondary pipe 3A is illustrated as the external pipe through which the internal pipe 10 is taken in and out. However, the internal pipe 10 can be inserted into and removed from the secondary pipe 3B instead of the secondary pipe 3A, or both the secondary pipes 3A and 3B. You may give the structure fixed to a pipe | tube.

Or the expansion-contraction spreading basket provided with the fixed part 40b as shown in FIG. 10 is also contained in this invention. In the fixed portion 40b, the clamp ring portion 11b and the movable cylindrical portion 12b are provided with a clamp ring 11c formed integrally with a synthetic resin or the like as a material. A boundary portion between the clamp ring portion 11b and the movable cylindrical portion 12b is a position indicated by a one-dot chain line in FIG. The previously described split groove 15 (not shown) is provided in the clamp ring portion 11b. The rear end surface, which is the other end of the movable cylindrical portion 12b of the clamp ring 11c, is formed as a pressure receiving surface 27A orthogonal to the tube core C. The pressure receiving surface 27 </ b> A is stopped by the step portion 19 of the holder 9. In FIG. 10, the same components as those shown in FIGS. 1 to 8 are denoted by the same reference numerals and description thereof is omitted.
In this telescopic spreading rod, the clamp ring 11c that has received the hydraulic pressure at the pressure receiving surface 27A is pushed in the direction of arrow F. As a result, the outer tapered surface 16 is pushed inward in the radial direction by the inner tapered surface 31 of the tightening cap 8, the clamp ring portion 11b of the clamp ring 11c is reduced in diameter, and the inner tube 10 is fixed to the sub piping 3A. This stretchable spreader can also be provided inexpensively and easily.

  Furthermore, the present invention also includes an expansion / contraction spreader 1a as shown in FIG. The expansion / contraction spreader 1a includes a main pipe 2a connected to a liquid feed pump and the like, two sub pipes 42A and 42B (an example of an outer pipe) branched from the main pipe 2 at a connection portion 5a, and a sub pipe 42A. The inner pipe 43A is movably accommodated in the tube core C direction, and the inner pipe 43B is movably accommodated in the sub pipe 42B. The inner pipes 43A and 43B are bent in the direction perpendicular to the pipe core C of the sub pipes 42A and 42B in the middle, and the spray nozzles 4H and 4H are attached inwardly facing each other at their respective tip portions. Further, spray nozzles 4G and 4G are also attached in the middle of the secondary pipes 42A and 42B. The above-described secondary pipes 42A and 42B are arranged so as to extend left and right on the same pipe core C in this example. Then, at the respective distal ends (one end) of the secondary pipes 42A and 42B, fixing portions 40 (see FIG. 3), 40a (see FIG. 9), 40b (see FIG. 10) having the fastening cap 8 or illustration are omitted. One of the fixed parts that have been deployed. Due to the presence of these fixing portions 40, 40a, 40b, etc., the inner pipes 43A, 43B are fixed to the secondary pipes 42A, 42B so that they can be taken in and out.

  Therefore, when the tightening caps 8 and 8 are loosened, the inner pipes 43A and 43B can be taken in and out of the secondary pipes 42A and 42B as shown in FIG. Then, after determining the width W between the spray nozzles 4H and 4H facing each other, the inner pipes 43A and 43B are fixed to the secondary pipes 42A and 42B by tightening the fastening caps 8 and 8, respectively. Thus, the expansion / contraction spreading rod 1a can variably adjust the width W between the spray nozzles 4H and 4H. In this case, even if the tightening caps 8 and 8 are weakly tightened, the inner pipes 43A and 43B are firmly fixed to the secondary pipes 42A and 42B by the function of the fixing portion. The inner pipes 43A and 43B go out in the middle of the operation and the width W between the spray nozzles 4H and 4H becomes wide.

1,1a Expansion / contraction spreader 3A Secondary pipe (outer pipe)
4F Spray nozzle 5 Chemical solution injection side connection part 8 Tightening cap 10 Inner tube 11, 11a, 11c Clamp ring 11b Clamp ring part 12, 12a Movable cylinder 12b Movable cylinder part 14 Male thread part 16 Outer taper surface 17 Outer taper surface 18 Spray nozzle side connection part 22 Inner taper surface 28 Female thread part 31 Inner taper surface 40, 40a, 40b Fixed part C Pipe core

Claims (4)

An outer tube having a male threaded portion at one end and a connecting portion on the chemical injection side at the other end, a connecting portion on the spray nozzle side at one end, and the other end side being accommodated in the outer tube so as to be movable in the tube direction. A clamp ring that is loosely fitted to the outer peripheral surface of the inner tube, and a tightening cap that is loosely fitted to the outer peripheral surface of the inner tube and disposed outside the clamp ring. Expansion and contraction configured to fix the inner tube and the outer tube in a variable length by pressing the clamp ring to the inner tube by screwing the female screw part provided on the inner peripheral surface and the male screw part of the outer tube In the spreader
A movable cylinder that is mounted on the chemical injection side of the clamp ring and is movable between the inner pipe and the outer pipe so as to be movable in the tube center direction. The movable cylinder receives the hydraulic pressure from the connection part on the chemical injection side. An expansion / contraction sprayer characterized in that the clamp ring is pressed against the spray nozzle and brought into pressure contact with the inner tube. The inner peripheral surface of the fastening cap on the spray nozzle side is formed as a tapered surface that decreases in diameter toward the spray nozzle side, and the outer peripheral surface on the spray nozzle side of the clamp ring decreases in diameter toward the spray nozzle side and The expansion / contraction spreader according to claim 1, which is formed as a taper surface that can be inserted into a taper surface of the tightening cap. The expansion / contraction spreader according to claim 2, wherein the clamp ring and the movable cylinder are integrally formed, and the end surface on the other end side of the movable cylinder is formed as a pressure receiving surface substantially orthogonal to the tube core. The inner peripheral surface of the movable cylinder on the spray nozzle side is formed as a tapered surface that increases in diameter toward the spray nozzle side, and the outer peripheral surface on the drug solution injection side of the clamp ring is reduced in diameter toward the drug solution injection side. The expansion / contraction spreader according to claim 1 or 2, wherein the expansion / contraction sprayer is formed as a tapered surface that can be inserted into a tapered surface of the movable cylindrical body.

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