JP5148672B2 - Die for blow molding machine, blow molding machine, sheath tube manufacturing method - Google Patents

Description

The present invention relates to a blow molding machine used for manufacturing a sheath pipe made of a synthetic resin that protects a flexible fluid pipe such as a water supply pipe or a hot water supply pipe disposed on a floor surface or a wall surface of a structure. The present invention relates to a manufacturing die, a blow molding machine, and a method of manufacturing the sheath tube .

  In general, when a fluid pipe such as a hot water supply pipe or a heating pipe is installed in a structure such as a detached house or a high-rise house, it is made of a flexible synthetic resin that is arranged in advance on the floor or wall surface of the structure. A double piping method is employed in which a flexible fluid pipe is inserted into the protective pipe or the sheath pipe. In the case of this double piping method, although the construction and maintenance of the fluid pipe can be facilitated and streamlined, the fluid pipe is protected or sheathed by the undulation of the fluid pipe due to the water hammer phenomenon. There is a problem that a sound is generated by colliding with the inner wall surface.

Therefore, as a measure for suppressing the occurrence of collision sound due to the undulation of the fluid pipe due to such a water hammer phenomenon, conventionally, as shown in FIG. The V-shaped punching wall portion 50A is formed as a buffer protrusion that can come into contact with the inserted fluid pipe 2 from the radial direction. In addition, there has been proposed a sheath tube in which the opening width W in the circumferential direction at the base end of the V-shaped punching wall portion 50A is configured to be larger than the maximum thickness of the corrugated flexible tube 50 (for example, a patent). Reference 1).
Further, as shown in FIG. 15, a flexible synthetic resin buffer tube having buffering properties closely contacting the inner wall surface 60a of the corrugated flexible tube 60 along the valley portion 60B and the peak portion 60A thereof. The buffer projections 62 are formed in a straight line or arcuately inward in the radial direction with the same thickness as the corrugated flexible tube 60 at a plurality of locations in the circumferential direction on the inner wall surface 61a of the buffer tube 61. A sheath tube is also proposed in which the fluid tube 2 is formed integrally and supported by the tips of the plurality of buffer projections 62 (see, for example, Patent Document 2).

Japanese Examined Patent Publication No. 7-43058 Japanese Patent Laid-Open No. 10-311462

  In the former former sheath tube, when the fluid tube 2 inserted in the corrugated flexible tube 50 is corrugated due to the water hammer phenomenon, a plurality of V-shapes that are in direct contact with the outer peripheral surface of the fluid tube 2 are used. Although the impact expansion force caused by the undulation of the fluid pipe 2 can be buffered by the elastic expansion and deformation of the launch wall 50A and the bending deformation of the circumferential wall of the corrugated flexible pipe 50 toward the radially outer side, the corrugated flexible pipe can be buffered. Under the condition that the outer wall surface of 50 is constrained by a fixed object, the cushioning function is lowered, and the presence of the relatively rigid V-shaped launch wall portion 50A makes it difficult for the corrugated flexible tube 50 to bend. The pipe 50 and the fluid pipe 2 are likely to be deteriorated in workability of piping.

  Further, in the conventional latter sheath tube, when the fluid tube 2 inserted in the corrugated flexible tube 60 is corrugated due to the water hammer phenomenon, the buffer protrusion 62 that directly contacts the outer peripheral surface of the fluid tube 2. Although the fluid pipe 2 can buffer the impact force caused by the undulation by the elastic deformation of the buffer pipe 61 and the elastic deformation of the buffer pipe 61 formed on the inner wall surface 60 a of the corrugated flexible pipe 60, The buffer tube 61 that is in close contact with the 60a is integrally formed, and the buffer protrusions 62 are also integrally formed at a plurality of locations in the circumferential direction of the inner peripheral surface 61a of the buffer tube 61. The corrugated flexible tube 60 is difficult to bend, and the workability of the corrugated flexible tube 60 and the fluid tube 2 is greatly reduced.

  In particular, since the fluid pipe 2 is supported by the tip of the buffer protrusion 62 projecting in a cantilever manner on the inner wall surface 61 a of the buffer pipe 61, It is necessary to ensure the thickness in the circumferential direction at least equal to or greater than the thickness of the corrugated flexible tube 60, and it is easy to promote a decrease in the bending characteristics of the corrugated flexible tube 60.

  The present invention has been made in view of the above-described circumstances, and its main problem is to maintain the high piping workability by suppressing the weight of the flexible tube or the corrugated flexible tube and the deterioration of the bending characteristics. However, it is effective in suppressing the occurrence of collision noise due to the undulation of the fluid pipe caused by the water hammer phenomenon.

Plurality of circumferential locations on the inner wall surface of the bendable synthetic resin flexible tube for inserting a flexible fluid tube, buffer projection projecting radially inwards a protective tube which is integrally formed,
Each of the buffer protrusions is composed of a thin plate-like piece in a cantilever state having a thickness smaller than the thickness of the flexible tube and curved or bent in a direction opposite to the inner wall surface of the flexible tube when viewed in the tube axis direction. In addition, each thin plate-like piece is curved or bent in the reverse warping direction until the tip is closer to the inner wall surface of the flexible tube than the intermediate position in the protruding direction when viewed in the tube axis direction. The tip of the piece may be configured to come into contact with the inner wall surface of the flexible tube as the thin plate-like piece is elastically deformed by contact with the inserted fluid pipe.

According to the above Ki構 formed, when the fluid tube is inserted through the flexible tube due to the water hammer phenomenon is wavy, flexible tube shock projections fluid tube which is protruded in the circumferential direction a plurality of locations of the inner wall surface of the The impact force due to the undulation of the fluid pipe can be reduced by elastically deforming with the abutment. In particular, in this configuration , each of the buffer protrusions is smaller than the thickness of the flexible pipe. Since each of the thin plate-like pieces itself is a flexible tube, it is formed of a cantilevered thin piece that is bent or bent in a direction opposite to the inner wall surface of the flexible tube when viewed in the tube axis direction. It is easy to smoothly follow and deform the bending, and the influence on the bending characteristics of the flexible tube can be reduced.

  Nevertheless, since the tip of each thin plate-like piece comes into contact with the inner wall surface of the flexible tube due to the elastic deformation of the thin plate-like piece due to contact with the inserted fluid pipe, the thin plate-like piece is in the tube axis direction view. The shape of the thin plate-like piece in which the gap is formed between the inner wall surface of the flexible tube and the thickness of the thin plate-like piece is smaller than the thickness of the flexible tube, and is close to the both-end support. The impact force received from the fluid pipe can be effectively reduced by utilizing the spring property.

  Moreover, since the base end side of each thin plate-like piece is directly formed integrally with the inner wall surface of the flexible tube, the weight of the entire flexible tube is increased compared to the case where a buffer tube is formed in the flexible tube. While being able to suppress, inhibiting the bending characteristic of a flexible tube can also be suppressed.

  Therefore, it is possible to effectively suppress the occurrence of collision sound due to the undulation of the fluid pipe caused by the water hammer phenomenon while maintaining the high piping workability by suppressing the weight of the flexible pipe and the deterioration of the bending characteristics. In addition, since the amount of resin used per unit length of the entire flexible tube can be greatly reduced, it is possible to provide the market with a high silencing effect advantageously in terms of cost.

Plurality of circumferential locations on the inner wall surface of the bendable synthetic resin waveform flexible tube for inserting the flexible fluid pipe, the buffer protrusion is integrally formed to protrude radially inward than the valleys in the peripheral surface of it A sheath tube,
Each of the buffer protrusions is a thin plate-like piece in a cantilever state having a thickness smaller than the thickness of the corrugated flexible tube and curved or bent in a direction opposite to the inner wall surface of the corrugated flexible tube when viewed from the tube axis direction. And each thin plate-like piece is curved or bent in the reverse warping direction until the tip is closer to the inner wall surface of the corrugated flexible tube than the intermediate position in the protruding direction in the tube axis direction view, The tip of each thin plate-like piece may be configured to come into contact with the inner wall surface of the corrugated flexible tube as the thin plate-like piece is elastically deformed by contact with the inserted fluid pipe.

According to the above Ki構 formed, when the fluid tube inserted waveform flexible tube due to the water hammer phenomenon is wavy, cushioning protrusions which are protruded in the circumferential direction a plurality of locations of the inner wall surface of the waveform flexible tube By elastically deforming with the contact with the fluid pipe, the impact force due to the undulation of the fluid pipe can be alleviated. In particular, in this configuration , each of the buffer protrusions has a thickness of the corrugated flexible pipe. Each of the thin plate-like pieces itself is made of a cantilevered thin piece that is bent or bent in a direction opposite to the inner wall surface of the corrugated flexible tube when viewed in the tube axis direction with a smaller thickness. Is easy to smoothly follow and deform the corrugated flexible tube, and the influence on the bending characteristics of the corrugated flexible tube can be reduced.

  Nevertheless, since the tip of each thin plate-like piece comes into contact with the inner wall surface of the corrugated flexible tube as the thin plate-like piece is elastically deformed by contact with the inserted fluid pipe, the thin plate-like piece is viewed in the tube axis direction. In this embodiment, the thickness of the thin plate-like piece is smaller than the thickness of the corrugated flexible tube, but a gap is formed between the inner wall surface of the corrugated flexible tube. The impact force received from the fluid pipe can be effectively reduced by utilizing the excellent spring property.

  Moreover, since the base end side of each thin plate-shaped piece is directly formed integrally with the inner wall surface of the corrugated flexible tube, the weight of the entire corrugated flexible tube is larger than when a buffer tube is formed in the corrugated flexible tube. Can be suppressed, and the bendability of the corrugated flexible tube can also be inhibited.

  Therefore, while suppressing the weight of the corrugated flexible pipe and the deterioration of the bending characteristics and maintaining high piping workability, it effectively suppresses the occurrence of collision sound due to the wave of the fluid pipe due to the water hammer phenomenon. In addition, since the amount of resin used per unit length of the entire corrugated flexible tube can be greatly reduced, it is possible to provide the market with a high silencing effect advantageously in terms of cost.

In addition, buffer projections projecting radially inward from the inner peripheral surface of the valley portion at a plurality of locations on the inner wall surface of the bendable synthetic resin corrugated flexible tube that is inserted through the flexible fluid tube. In the integrally formed sheath tube,
Each of the buffer protrusions is bent or bent in a direction opposite to the inner wall surface of the corrugated flexible tube in a tube axis direction view with a thickness smaller than the thickness of the corrugated flexible tube, and in the curved or bent direction. You may be comprised from the thin plate-shaped piece integrally formed in the inner wall surface of the corrugated flexible tube at both ends.

According to the above configuration, when the fluid tube inserted in the corrugated flexible tube is corrugated due to the water hammer phenomenon, the buffer projections formed to protrude at a plurality of locations in the circumferential direction of the inner wall surface of the corrugated flexible tube are fluid. By elastically deforming with the contact with the tube, the impact force due to the undulation of the fluid tube can be reduced. In particular, in this configuration , each of the buffer protrusions is less than the thickness of the corrugated flexible tube. Since each of the thin plate-like pieces itself is made of a thin plate-like piece that is curved or bent in a direction opposite to the inner wall surface of the wave-like flexible tube when viewed in the tube axis direction with a small thickness, It is easy to follow and bend smoothly, and the influence on the bending characteristics of the corrugated flexible tube can be reduced.

  Still, since both ends in the bending or bending direction of each thin plate-like piece are integrally formed on the inner wall surface of the corrugated flexible tube, while configuring the thickness of the thin plate-like piece smaller than the thickness of the corrugated flexible tube, It is possible to effectively relieve the impact force received from the fluid pipe by utilizing the excellent spring property of the thin plate-shaped piece in which a gap is formed between the inner wall surface of the corrugated flexible pipe, and further, the corrugated flexibility. Compared with the case where a buffer tube is formed in the tube, an increase in weight of the entire corrugated flexible tube can be suppressed, and inhibition of the bendability of the corrugated flexible tube can also be suppressed.

  Therefore, while suppressing the weight of the corrugated flexible pipe and the deterioration of the bending characteristics and maintaining high piping workability, it effectively suppresses the occurrence of collision sound due to the wave of the fluid pipe due to the water hammer phenomenon. In addition, since the amount of resin used per unit length of the entire corrugated flexible tube can be greatly reduced, it is possible to provide the market with a high silencing effect advantageously in terms of cost.

Plurality of circumferential locations on the inner wall surface of the bendable synthetic resin waveform flexible tube for inserting the flexible fluid pipe, the buffer protrusion is integrally formed to protrude radially inward than the valleys in the peripheral surface of it A sheath tube,
A plurality of the buffer projections are formed so as to have a thickness smaller than the thickness of the corrugated flexible tube, and are formed so as to have an opposing interval smaller than the opposing interval between the buffer projections when viewed in the tube axis direction. You may be comprised from the thin-plate shaped piece.

According to the above Ki構 formed, when the fluid tube is inserted into the waveform flexible tube due to the water hammer phenomenon is wavy, cushioning protrusions which are protruded in the circumferential direction a plurality of locations of the inner wall surface of the waveforms flexible tube Is elastically deformed along with the contact with the fluid pipe, the impact force caused by the undulation of the fluid pipe can be reduced. In particular, in this configuration , each of the buffer protrusions is formed of the corrugated flexible pipe. Since a plurality of thin plate-like pieces each having a thickness smaller than the thickness are formed as a group, the plurality of thin plate-like pieces constituting each buffer protrusion smoothly follow the bending of the corrugated flexible tube. It is easy to deform and the influence on the bending characteristics of the corrugated flexible tube can be reduced.

  Nevertheless, while constituting the thickness of each thin plate-like piece smaller than the thickness of the corrugated flexible tube, it is possible to effectively relieve the impact force received from the fluid tube with a plurality of thin plate-like pieces formed in an aggregate, Furthermore, it is possible to suppress an increase in the weight of the entire corrugated flexible tube as compared with the case where a buffer tube is formed in the corrugated flexible tube, and also to inhibit the bendability of the corrugated flexible tube. Can do.

  Therefore, while suppressing the weight of the corrugated flexible pipe and the deterioration of the bending characteristics and maintaining high piping workability, it effectively suppresses the occurrence of collision sound due to the wave of the fluid pipe due to the water hammer phenomenon. In addition, since the amount of resin used per unit length of the entire corrugated flexible tube can be greatly reduced, it is possible to provide the market with a high silencing effect advantageously in terms of cost.

  Further, the base end of the thin plate-like piece may be integrally formed continuously over the entire region in the tube axis direction on the inner wall surface of the corrugated flexible tube.

  According to the above configuration, since the waist on the base end side of the thin plate-like piece integrally formed continuously along the crests and troughs on the inner wall surface of the corrugated flexible tube becomes strong, the spring property of the thin plate-like piece The impact force received from the fluid pipe can be reduced more effectively.

It relates to a double pipe structure for supplying hot water supply, water supply hot water pipe as said fluid conduit to the flexible tube may be inserted.

A double-pipe structure for hot water and hot water in which a hot water and hot water pipe as the fluid pipe is inserted into the flexible pipe, and each thin plate piece is in contact with the thin hot water pipe and the thin plate piece. When the tip comes into contact with the inner wall surface of the flexible tube, a gap that allows elastic deformation of each thin plate-like piece radially outward between the inner wall surface and each thin plate-like piece opposed thereto. May be formed.
A first characteristic configuration of the present invention is a die for a blow molding machine, which is a heat-softened cylindrical parison for forming a corrugated flexible tube made of a bendable synthetic resin that passes through a flexible fluid tube. A first annular resin extrusion port that continuously extrudes the air and pressure air for pressing the heat-softened parison continuously extruded from the first resin extrusion port against the tube wall molding surface with a blow pressure. An air spout is formed,
The inner wall surface of the corrugated flexible tube as viewed from the tube axis direction with a thickness smaller than the thickness of the crests and troughs of the corrugated flexible tube as buffer protrusions at a plurality of circumferential positions of the first resin extrusion port Is a thin plate-like piece in a cantilever shape that is curved or bent in a reverse warping direction, or a corrugated flexible tube having a thickness smaller than the thickness of the crest and trough of the corrugated flexible tube in the tube axis direction view A thin plate-like piece that is curved or bent in a direction opposite to the inner wall of the inner wall, and both ends of the bent or bent direction are integrally formed on the inner wall of the corrugated flexible tube, or a peak portion of the corrugated flexible tube, and A heat-softened thin plate or film plate resin for molding a plurality of thin plate pieces having a thickness smaller than the thickness of the trough is continuously melted on the inner wall surface of the parison. A slit-shaped slit that cuts inward in the radial direction from the first resin extrusion port in order to be pushed out in a worn or fused state 2 resin extrusion mouth is in that it is communicating formed.
A second characteristic configuration of the present invention is a blow molding machine provided with the blow molding machine die described in the first characteristic configuration, wherein a center line of the blow molding machine die and a corrugated shape to be blow molded are available. Circulates a number of split molds with a semi-cylindrical tube wall molding surface on both sides of the blow molding center line that passes through the tube axis of the flexible tube with respect to the outer wall surface of the upper half side of the outer wall surface of the corrugated flexible tube. A first circulation path to be moved, and a second circulation path to circulate and move a large number of divided molds having a semi-cylindrical tube wall molding surface with respect to a lower half side outer wall surface of the outer wall surface of the corrugated flexible tube. And
Of the two circulation paths, a pair of split molds that move back along each return path part are joined at the start end of the molding path part corresponding to the first resin extrusion port of the blow molding machine die. In addition, the two split molds are moved toward the end side of the molding path portion in the joined state.
A third characteristic configuration of the present invention is a sheath tube manufacturing method using the blow molding machine according to the second characteristic configuration, wherein a plurality of the divided molds that are circulated and moved along the both circulation paths, While being joined and moved in the molding path portion corresponding to the first resin extrusion port, the heat-softened parison is continuously extruded from the first resin extrusion port, and at the same time, it is heat-softened from the second resin extrusion port portion. The thin plate-like or membrane-plate-like resin is extruded in a continuous fusion or fusion state to the inner wall surface of the parison, and the parison in which the thin-plate or membrane plate-like resin is integrally formed is formed by the pressure air from the air outlet. The parison is molded into a corrugated flexible tube by pressing against the tube wall molding surface of both split molds with blow pressure, and at the same time, the thin plate-like piece is integrally formed with a thin plate or film plate resin on the inner wall surface thereof There is in point to do.

The longitudinal cross-sectional view of the corrugated flexible tube which shows 1st Embodiment of this invention II-II sectional view of FIG. Cross section when inserted through hot and cold water supply pipes Enlarged cross-sectional view of the main part when inserted through the hot water and hot water supply pipes Explanatory drawing which shows the blow molding manufacturing method of a corrugated flexible tube Expanded cross-sectional side view of a blow molding machine die VII-VII line sectional view of FIG. The expanded cross-sectional view of the principal part of the corrugated flexible tube which shows 2nd Embodiment of this invention The expanded cross-sectional view of the principal part of the corrugated flexible tube which shows 3rd Embodiment of this invention. Cross-sectional view of a corrugated flexible tube showing a fourth embodiment of the present invention Enlarged cross-sectional view of the main part The expanded cross-sectional view of the principal part of the corrugated flexible tube which shows 5th Embodiment of this invention Cross-sectional view of a corrugated flexible tube showing a sixth embodiment of the present invention Cross-sectional view of a conventional corrugated flexible tube Cross-sectional view of another conventional corrugated flexible tube

[First Embodiment]
1 to 4 are examples of fluid pipes having flexibility made of synthetic resin in a corrugated flexible pipe 1 made of crosslinked polyethylene constituting a flexible sheath pipe P made of synthetic resin. A double-pipe structure in which a cross-linked polyethylene water supply hot water supply pipe 2 is inserted and the sheath pipe P is configured as a protective pipe for the water supply hot water supply pipe 2 is shown. The outer peripheral surface 2a of the hot and cold water supply pipe 2 is located at a radially inner position than the inner peripheral surface of the valley portion 1B at each of a plurality of locations (four locations in the present embodiment) that are equally spaced in the circumferential direction. A buffered projection 3 made of cross-linked polyethylene that is in contact with the tube is integrally formed along the tube axis (tube axis) X direction.

  Each of the buffer protrusions 3 has a thickness t3 smaller than the thicknesses t1 and t2 of the peak portion 1A and the valley portion 1B of the corrugated flexible tube 1, and the inner wall surface 1a of the corrugated flexible tube 1 in the tube axis X direction view. It is composed of a cantilevered thin plate-like piece bent or bent in the reverse warping direction, and the tip 3a of each thin plate-like piece 3 is not in contact with the hot water supply hot water pipe 2 and is a corrugated flexible pipe. The inner wall surface of the corrugated flexible tube 1 is located away from the inner wall surface 1a in the radial direction, and the water supply hot water pipe 2 is in contact with the radial direction from the radial direction. In the initial contact state immediately after the tip 3a of each thin plate-like piece 3 contacts the inner wall surface 1a of the corrugated flexible tube 1, the corrugated flexible tube contacts the la 1 between the inner wall surface 1a of 1 and the back surface of each thin plate-like piece 3 opposed to each other in the radial direction. Void S for permitting the elastic deformation in the radial outward side of the plate-like pieces 3 (bending deformation) is formed.

  The base end 3b of each thin plate-like piece 3 is integrally formed continuously over the entire region in the tube axis X direction along the crest 1A and the trough 1B constituting the inner wall surface 1a of the corrugated flexible tube 1. At the same time, the tip 3a of each thin plate-like piece 3 is formed in a straight line along the tube axis X direction.

  And when the water supply hot water supply pipe 2 inserted in the corrugated flexible tube 1 is corrugated due to the water hammer phenomenon, the buffer projections are formed to project at a plurality of locations in the circumferential direction of the inner wall surface 1a of the corrugated flexible tube 1 3 is elastically deformed as it comes into contact with the hot water supply hot water pipe 2, so that the impact force caused by the undulation of the hot water hot water supply pipe 2 can be alleviated. Cantilever that is curved or bent in a direction opposite to the inner wall surface 1a of the corrugated flexible tube 1 when viewed in the tube axis X direction with a thickness t3 smaller than the thicknesses t1 and t2 of the crest 1A and the trough 1B. Since the thin plate-like piece 3 itself is configured to smoothly follow and deform the bending of the corrugated flexible tube 1, the influence on the bending characteristics of the corrugated flexible tube 1 can be reduced. it can.

  Nevertheless, the tip 3a of each thin plate-like piece 3 comes into contact with the inner wall surface 1a of the corrugated flexible tube 1 along with the elastic deformation of the thin plate-like piece 3 due to contact with the inserted water supply and hot water supply pipe 2. The piece 3 is in a form close to both-end support in the tube axis X direction view, and the thickness t3 of the thin plate-like piece 3 is smaller than the thickness of the corrugated flexible tube 1, but the inner wall surface of the corrugated flexible tube 1 The impact force received from the hot water / hot water supply pipe 2 can be effectively reduced by utilizing the excellent spring property of the thin plate-like piece 3 in which the gap S is formed between 1a and 1a.

Next, an example of the dimension of the sheath pipe P comprised as mentioned above is shown.
[Example 1]
The maximum outer diameter D1 of the corrugated flexible tube 1 is 23.5 mm, the minimum inner diameter D2 is 18 mm, the thickness t1 of the peak 1A is 0.35 mm, the thickness t2 of the valley 1B is 0.65 mm, and the pitch P1 is 4.3 mm. In the case of a certain sheath tube P, the thickness t3 of the thin plate-like piece 3 is 0.08 to 0.12 mm, and the length L1 of the thin plate-like piece 3 is 4 to 6 mm.

[Example 2]
The maximum outer diameter D1 of the corrugated flexible tube 1 is 28.0 mm, the minimum inner diameter D2 is 22.5 mm, the thickness t1 of the peak 1A is 0.35 mm, the thickness t2 of the valley 1B is 0.65 mm, and the pitch P1 is 4. In the case of the sheath pipe P which is 7 mm, the thickness t3 of the thin plate-like piece 3 is 0.08 to 0.12 mm, and the length L1 of the thin plate-like piece 3 is 6 to 8 mm.

[Example 3]
The maximum outer diameter D1 of the corrugated flexible tube 1 is 35.0 mm, the minimum inner diameter D2 is 28.0 mm, the thickness t1 of the peak 1A is 0.35 mm, the thickness t2 of the valley 1B is 0.65 mm, and the pitch P1 is 5. In the case of the sheath tube P having a thickness of 1 mm, the thickness t3 of the thin plate-like piece 3 is 0.08 to 0.12 mm, and the length L1 of the thin plate-like piece 3 is 6 to 8 mm.

Next, a method for manufacturing the sheath tube 1 configured as described above using a blow molding machine A as shown in FIGS.
In the blow molding machine A, the upper half side of the outer wall surface 1b of the corrugated flexible tube 1 is located on both sides of the blow molding center line passing through the center line of the die 6 and the tube axis X of the corrugated flexible tube 1 to be blow molded. A first circulation path R for circulating and moving a large number of divided molds 5A having a semi-cylindrical tube wall forming surface 4A with respect to the outer wall surface, and a lower half side outer wall surface in the outer wall surface 1b of the corrugated flexible tube 1 A second circulation path L that circulates and moves a large number of divided molds 5B having a cylindrical surface-shaped tube wall molding surface 4B, and an annular ring formed in the die 6 of the circulation paths R and L. At the starting end of the molding path portion corresponding to the first resin extrusion port 7, the pair of split molds 5 </ b> A and 5 </ b> B returning and moving along the return path portions are joined together, and both split moldings are performed in the joined state. Die 5A, 5B at the end of the molding path And it is configured to move toward and.

  Further, the die 6 of the blow molding machine A has an annular first resin extrusion port 7 for continuously extruding a heat-softened parison 8 for molding the corrugated flexible tube 1, and a first resin extrusion port 7. And an air outlet 9 for injecting pressurized air for pressing the heat-softened parison 8 continuously extruded from the pipe wall molding surfaces 4A and 4B of the split molds 5A and 5B with a blow pressure. In addition, at each of the four locations that are equally spaced in the circumferential direction of the first resin extrusion port 7 of the die 6, a heat-softened thin plate or film plate shape for forming the thin plate-like piece 3 that is a buffer protrusion is formed. In order to extrude the resin 8A on the inner wall surface of the parison 8 in a continuous fusion or fusion state, the tube axis X has a thickness t3 smaller than the thicknesses t1 and t2 at the peak 1A and valley 1B of the corrugated flexible tube 1. Curved in the direction of reverse warping from the inner wall surface 1a of the corrugated flexible tube 1 in a direction view. The slit-like second resin extrusion mouth 7A bent, are communicated formed in a state of cut into the first resin extruding port 7 radially inward.

  Of the two circulation paths R and L, the split molds 5A and 5B are joined and moved in the molding path portion corresponding to the annular first resin extrusion port 7 formed in the die 6 of the blow molding machine A. On the other hand, the heat-softened cylindrical parison 8 continuously extruded from the first resin extrusion port 7 of the blow molding machine A is blown from the pressure air formed at the tip of the die 6 and injected from the air outlet 9. Inward in the radial direction, pressed against the tube wall molding surfaces 4A and 4B of the two split molds 5A and 5B with pressure, and communicated at four locations at equal intervals in the circumferential direction of the first resin extrusion port 7 of the die 6 A corrugated flexible tube 1 is formed by extruding a thin plate-like or membrane-like resin 8A heat-softened in a fused or fused state continuously to the inner wall surface of the parison 8 from a slit-like second resin extrusion port 7A that cuts into the wall. In mountain part 1A and valley part 1B The cantilevered thin plate-like piece 3 is formed integrally with a thickness t3 smaller than t1 and t2 and is curved or bent in the direction of warping opposite to the inner wall surface 1a of the corrugated flexible tube 1 when viewed in the tube axis X direction. The formed corrugated flexible tube 1 is blow-molded.

  That is, while a large number of divided molds 5A and 5B that are circulated and moved along both circulation paths R and L are joined and moved in the molding path portion corresponding to the first resin extrusion port 7 of the blow molding machine A, At the same time as continuously extruding the heat-softened parison 8 from the first resin extrusion port 7 of the blow molding machine A, a slit-like shape cut inward in the radial direction formed in communication with four circumferential positions of the first resin extrusion port 7. A thin plate-like or membrane-plate-like resin 8A heat-softened from the second resin extrusion port 7A is extruded in a continuous fusion or fusion state to the inner wall surface of the parison 8, and a thin plate-like or membrane-plate-like resin 8A is integrally formed. When the parison 8 is pressed against the tube wall forming surfaces 4A and 4B of the split molds 5A and 5B with a blow pressure, the parison 8 is formed into the corrugated flexible tube 1 and at the same time a thin plate or film on the inner wall surface 1a. Loose with plate-shaped resin 8A The thin plate piece 3 of cantilever state constituting the protrusion can be integrally formed.

  Therefore, a slit-like second resin extrusion port portion 7A that cuts radially inward at a plurality of locations in the circumferential direction of the first resin extrusion port 7 is formed in a thin plate shape on the inner wall surface 1a of the corrugated flexible tube 1. Since the piece 3 can be integrally formed and the amount of resin used per unit length can be reduced, the blow molding equipment can be simplified, and the undulation of the water supply and hot water supply pipe 2 caused by the water hammer phenomenon can be achieved. It is possible to efficiently and inexpensively manufacture the sheath pipe P that can effectively suppress the generation of the collision sound due to the above.

  In addition to the cross-linked polyethylene pipe described in the first embodiment, the fluid pipe 2 such as a hot water supply hot water pipe is a composite of a flexible synthetic resin pipe such as a polyethylene pipe or a polybutene pipe, and a metal. In addition, a flexible metal composite synthetic resin tube can be suitably used.

  Furthermore, as the corrugated flexible tube 1, in addition to the crosslinked polyethylene tube described in the first embodiment, a flexible synthetic resin tube such as a polyethylene tube or a polybutene tube can be suitably used.

[Second Embodiment]
In the first embodiment described above, the tip 3a of each thin plate-like piece 3 is held at a position spaced radially inward from the inner wall surface 1a of the corrugated flexible tube 1 when there is no load in contact with the water supply hot water supply tube 2. When the hot and cold water supply pipe 2 abuts from the radial direction, it can be slidably moved in the circumferential direction relative to the inner wall surface 1a of the corrugated flexible pipe 1 as the thin plate-like piece 3 is elastically deformed by the abutment. Although configured to be in contact with each other, as shown in FIG. 8, the tip 3 a of each thin plate-like piece 3 is connected to the inner wall surface 1 a of the corrugated flexible tube 1 even when there is no load in contact with the water supply hot water supply tube 2. On the other hand, they may be brought into contact with each other so as to be relatively slidable in the circumferential direction.
In addition, since the other structure is the same as the structure demonstrated in 1st Embodiment, the same number is attached to the same structure location as 1st Embodiment, and the description is abbreviate | omitted.

[Third Embodiment]
FIG. 9 shows another embodiment of a bendable synthetic resin sheath pipe P that is inserted through a water supply hot water supply pipe 2 that is an example of a flexible fluid pipe. In this embodiment, the inner wall surface of the corrugated flexible pipe 1 is shown. 1a and at a plurality of locations spaced at equal intervals in the circumferential direction thereof, the tube axis X has a thickness t3 smaller than the thicknesses t1 and t2 of the crest 1A and trough 1B of the corrugated flexible tube 1. The thin plate-like piece 3 that is curved or bent in a direction opposite to the inner wall surface 1a of the corrugated flexible tube 1 in a direction view is continuous with the inner wall surface 1a of the corrugated flexible tube 1 at both ends in the curved or bent direction. A composite that is integrally formed in a both-end holding state and abuts against the outer peripheral surface 2a of the hot and cold water supply pipe 2 at the radially inner position with respect to the inner peripheral surface of the valley portion 1B of the corrugated flexible pipe 1 It is constituted by a resin-made buffer projection, and is relative to the inner wall surface 1a of the corrugated flexible tube 1 in the radial direction. Between the back of each thin plate piece 3, it is formed a space S that allows elastic deformation (bending deformation) in the radially outer side of the thin plate piece 3.
In addition, since the other structure is the same as the structure demonstrated in 1st Embodiment, the same number is attached to the same structure location as 1st Embodiment, and the description is abbreviate | omitted.

[Fourth Embodiment]
FIG. 10 and FIG. 11 show another embodiment of a bendable synthetic resin sheath pipe P that is inserted through a water supply hot water supply pipe 2 that is an example of a flexible fluid pipe. In this embodiment, the corrugated flexible pipe 1 is shown. The inner wall surface 1a of the corrugated flexible tube 1 has a thickness t3 smaller than the thicknesses t1 and t2 of the peak portion 1A and the valley portion 1B of the corrugated flexible tube 1 at each of a plurality of locations that are equally spaced in the circumferential direction. A plurality of thin plate-like pieces 10 each having a thin plate shape or a membrane plate shape are formed so as to protrude radially inward and parallel to the radial direction, and the plurality of thin plate pieces thus formed are formed. 10 is formed into a synthetic resin buffer protrusion that contacts the outer peripheral surface 2a of the hot water supply hot water pipe 2 at a radially inner position than the inner peripheral surface of the trough portion 1B in the corrugated flexible pipe 1, and is formed in a collective manner. The tips 10 a of the plurality of thin plate-like pieces 10 are evenly contacted with the outer peripheral surface 2 a of the water and hot water supply pipe 2. As to, it is formed along the outer circumferential surface 2a and the same or substantially the same radius of curvature of the water supply pipe 2.
In addition, since the other structure is the same as the structure demonstrated in 1st Embodiment, the same number is attached to the same structure location as 1st Embodiment, and the description is abbreviate | omitted.

[Fifth Embodiment]
In the fourth embodiment described above, the tips 10a of the plurality of thin plate-like pieces 10 formed in an aggregate are formed along the same or substantially the same radius of curvature as the outer peripheral surface 2a of the hot water supply pipe 2. As shown in the figure, the tips 10a of a plurality of thin plate-like pieces 10 formed in an aggregate are formed in a mountain shape when viewed from the tube axis X direction in a state in which the amount of protrusion inward in the radial direction increases toward the center in the circumferential direction. May be.

[Sixth Embodiment]
FIG. 13 shows that the outer peripheral surface and the inner peripheral surface are continuous with the same outer diameter and the same inner diameter in a bendable synthetic resin protective tube P that is inserted through a water supply hot water supply pipe 2 that is an example of a flexible fluid pipe. Another embodiment in which the technology of the present invention is applied to a straight tubular protective tube P is shown. In this embodiment, an inner wall surface 11a of a flexible tube 11 made of a bendable synthetic resin that passes through a hot water supply hot water tube 2, and In each of a plurality of locations that are equally spaced in the circumferential direction, a thickness t3 that is smaller than the thickness t4 of the flexible tube 11 is opposite to the inner wall surface 11a of the flexible tube 11 in the tube axis X direction. The thin plate-like pieces 3 curved or bent in the direction are integrally formed in a cantilever state, and each of the thin plate-like pieces 3 is provided at a position radially inward from the inner wall surface 11 a of the flexible tube 11. And a synthetic resin buffer projection that abuts the outer peripheral surface 2a of the flexible tube 11. A gap S is formed between the wall surface 11a and the back surface of each thin plate-like piece 3 that is opposed to the wall surface 11a in the radial direction to allow elastic deformation (flexure deformation) of each thin plate-like piece 3 to the radially outward side. It is.

[Other Embodiments]
(1) In the first embodiment described above, the inner wall surface 1a of the corrugated flexible tube 1 has a diameter larger than that of the inner surface of the valley portion 1b at each of four locations that are equally spaced in the circumferential direction. The thin plate-like pieces 3 as buffer protrusions that come into contact with the outer peripheral surface 2a of the water supply and hot water supply pipe 2 at the inner position in the direction are integrally formed, but the number of the thin plate-like pieces 3 formed is preferably 2 to 10.
(2) In the first embodiment described above, the base end 3b of each of the thin plate-like pieces 3 is arranged along the peak portion 1A and the valley portion 1B constituting the inner wall surface 1a of the corrugated flexible tube 1 in the tube axis X direction. However, the base end 3b of each thin plate-like piece 3 may be integrally formed only on the inner peripheral surface of the valley portion 1B of the corrugated flexible tube 1.

P protective tube (sheath tube)
S gap t1 peak thickness t2 valley thickness t3 thin plate thickness t4 flexible tube thickness X tube axis 1 corrugated flexible tube 1A peak 1B valley 1a inner wall 1b outer wall 2 fluid pipe (water supply) Hot water pipe)
2a Outer peripheral surface 3 Buffer protrusion (thin plate-shaped piece)
3a tip 3b base 10 buffer protrusion (thin plate-like piece)
10a tip 11 flexible tube 11a inner wall surface

Claims (3)

An annular first resin extrusion port for continuously extruding a heat-softened cylindrical parison for forming a corrugated flexible tube made of a bendable synthetic resin that passes through a flexible fluid tube; An air outlet for injecting pressurized air for pressing the heat-softened parison continuously extruded from the resin extrusion port against the tube wall molding surface with a blow pressure is formed,
The inner wall surface of the corrugated flexible tube as viewed from the tube axis direction with a thickness smaller than the thickness of the crests and troughs of the corrugated flexible tube as buffer protrusions at a plurality of circumferential positions of the first resin extrusion port Is a thin plate-like piece in a cantilever shape that is curved or bent in a reverse warping direction, or a corrugated flexible tube having a thickness smaller than the thickness of the crest and trough of the corrugated flexible tube in the tube axis direction view A thin plate-like piece that is curved or bent in a direction opposite to the inner wall of the inner wall, and both ends of the bent or bent direction are integrally formed on the inner wall of the corrugated flexible tube, or a peak portion of the corrugated flexible tube, and A heat-softened thin plate or film plate resin for molding a plurality of thin plate pieces having a thickness smaller than the thickness of the trough is continuously melted on the inner wall surface of the parison. A slit-shaped slit that cuts inward in the radial direction from the first resin extrusion port in order to be pushed out in a worn or fused state Blow molding machine die 2 resin extrusion mouth is communicating formed. A blow molding machine provided with the die for a blow molding machine according to claim 1,
On the both sides of the blow molding center line passing through the center line of the die and the tube axis of the corrugated flexible tube to be blow molded, the tube wall of a semi-cylindrical surface shape with respect to the upper half side outer wall surface of the outer wall surface of the corrugated flexible tube A first circulation path that circulates and moves a large number of divided molds having a molding surface, and a plurality of split moldings that have a semi-cylindrical tube wall molding surface with respect to the lower half outer wall surface of the outer wall surface of the corrugated flexible tube. A second circulation path for circulating the mold,
Among the circulation paths, a pair of split molds that move back along the return path portions at the start end of the molding path portion corresponding to the first resin extrusion port of the die are joined together and joined together A blow molding machine configured to move both split molds toward the end side of the molding path portion in a state. A sheath tube manufacturing method using the blow molding machine according to claim 2,
The plurality of split molds that are circulated along the circulation paths are joined and moved in the molding path part corresponding to the first resin extrusion port, and the softened from the first resin extrusion port. Simultaneously extruding the parison and simultaneously extruding the thin plate-like or membrane-plate-like resin heat-softened from the second resin extrusion port portion in a continuous fusion or fusion state to the inner wall surface of the parison, the thin plate-like or membrane plate The parison is formed into a corrugated flexible tube at the same time by pressing the parison formed integrally with the resin into the tube wall molding surface of the two split molds with the blow pressure of the compressed air from the air outlet. A method for manufacturing a sheath tube, in which the thin plate-like piece is integrally formed with a thin plate-like or membrane-plate-like resin on the inner wall surface of the tube.

Images