JPS5919811B2 - Method for manufacturing stretchable synthetic resin flexible hose - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a method for easily manufacturing a synthetic resin hose that has good adhesion between tube materials and has excellent elasticity and flexibility.

Flexible hoses made of a spiral reinforcement made of hard synthetic resin and a thin-walled elastic tube made of soft synthetic resin are extremely lightweight, easy to handle, highly flexible, and have excellent abrasion resistance. It has come to be widely used for transporting air, ventilation, dust collection, and various other fluids. However, this type of hose becomes bulkier as the inner diameter of the hose increases, making it inconvenient to transport and handle during sales, and furthermore, packaging costs, transportation costs, warehousing costs, etc. increase significantly. The following shortcomings have become noticeable, and solutions to these problems are strongly desired. In order to solve these shortcomings, one method is to compress the thin-walled elastic tubular body in such a way that when the hose is compressed in the longitudinal direction, the thin-walled elastic tubular body protrudes toward the inner surface of the hose, shortening the length of the hose. There are hoses that are large, have long pleats, or have thin elastic tubes that are thinner in the center between the helical reinforcing bodies.

In addition, when conventionally forming this type of hose, a thin sheet of soft synthetic resin containing a hard synthetic resin reinforcing body, for example, a band-shaped tube material having thin walled parts on both sides of the part containing the reinforcing body, is used to form a tube using rollers. The reinforcing member is wound in a spiral direction, and is overlapped and heat-sealed at a position inside the tube where the reinforcing member is not provided.

However, since no pressing force was applied to the thin sheets in the overlapped portion, the heat fusion was uneven and the hoses often separated during use. Therefore, there is a forming method that uses a pressing roller that overlaps the thin sheet at the pipe wall part and applies pressing force to ensure uniform and sufficient heat fusion (adhesion), but it is difficult to adjust the pressing force and it is difficult to press. If the pressure was too great, the sheets were thin and in an uncured state, so they often broke or the thickness changed. On the other hand, when applying pleats to the pipe wall to give stretchability and flexibility to the hose, conventionally, a group of tube forming machine rollers was used, which had uneven pitches that corresponded to the reinforcing body pitch and the pleat depth of the formed pipe. Use. Furthermore, the formed pipe is crimped by wrapping an endless string around the wall of the formed pipe. This method is complicated because it requires tube forming machine rollers and endless strings that match the shape of the pipe, including the pitch and pleat depth of the formed pipe.

The present invention relates to a method for manufacturing a stretchable flexible hose that does not have these drawbacks. The present invention eliminates such pleating of the pipe wall. without special typing. Similar to the method used to create straight pipes, a roller with a smooth surface is used to give the pipe wall a wavy shape. The purpose of this project is to manufacture a stretchable flexible hose.The main feature of this product is that a band-shaped tube material consisting of a thin sheet of soft synthetic resin that serves as the tube wall and a reinforcing body of hard synthetic resin is wound in a spiral shape. When manufacturing a hose by heat-sealing the edges. A hard synthetic resin reinforcing body is integrated along the length of the edge surface of a thin sheet of soft synthetic resin. And the cross section of the thin sheet is
Melt-extrude a tube material in the shape of a parallelogram, whose thickness gradually decreases in a wedge-like manner over a length approximately equal to the width of the reinforcement body at the bottom of the reinforcement body, and the thickness also gradually decreases at the diagonal of that part. ．． A plurality of rotating rollers with smooth surfaces are arranged so that the virtual peripheral surface formed by their axes forms a tapered truncated conical surface. At the tapered end of the circumferential surface, each roller axis is displaced in the same direction in the circumferential direction.While the tube material is continuously wound around a group of rollers of a forming machine, at the lower part of the reinforcing body portion of the tube material, After overlapping and heat-sealing the wedge-shaped parts of the thin sheets. Manufacture of a stretchable flexible hose made of synthetic resin characterized by cooling the uncured tube being formed on the rollers of a molding machine, thereby contracting the tube wall between the reinforcing bodies and recessing the tube inside the tube. It's a method.

In the present invention, the weight part of a thin sheet of soft synthetic resin can be thermally fused without using a special device such as a press roller as in the past. At the bottom of the tube material reinforcement. Each wedge-shaped part has a gradually decreasing thickness. By applying weight to the edge, the pressing force of the reinforcing body is applied evenly and sufficiently.

or. The tube forming machine also does not require special rollers with uneven surfaces as in the past. Moreover, there is no need for endless cords for pleating the tube wall, and rollers with smooth surfaces are arranged on a tapered truncated conical surface. Furthermore, conventional methods have been used to impart elasticity to this type of tube. In the method of the present invention, the pipe wall part is tapered with a wall thickness, or the middle part is made thin or pleats are formed. Using a thin sheet of approximately uniform thickness, cooling is performed on the rollers of the molding machine immediately after tube forming, and the cooling rate of the soft synthetic resin of the thin sheet, which will become the tube wall, is the same as the cooling rate of the hard synthetic resin of the reinforcing body. It takes advantage of its larger size and the fact that the 6-tube molding machine roller group is arranged in a tapered conical shape. The contraction of the soft synthetic resin is carried out without being disturbed by the rollers. As a result, the tube wall of the thin sheet becomes concave toward the inside of the tube. This provides stretch and flexibility. in this way. By utilizing the shape of the tube material, the arrangement of the roller group of the tube forming machine, and the difference in the cooling rate of the resin, without using any special equipment like in the past, the heat fusion of the tube material is uniform and sufficient, and the tube material is stretchable and flexible. This makes it possible to easily mold a hose with good properties.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 illustrates the process of forming a hose.

In the die 1 of an extruder, a thin sheet 2 of soft synthetic resin, which will become the 6-tube wall part, and a reinforcing body 3 of hard synthetic resin are integrated. This is extruded from an extruder as a tube material. I died in a tube forming machine,
The power from the prime mover 4 is transferred to the belt 5. A drive shaft 7 VC is transmitted through a pulley 6, and a drive gear 9 fitted to the drive shaft 7 is supported by a bearing 8, and a driven shaft 1 is supported by a bearing 10.
A driven gear 12 fitted to the base of the driven shaft 11 meshes with the driven gear 12, and the base of a roller 14 with a smooth surface is connected to the tip of the driven shaft 11 by a universal joint 13, and the roller 14 is driven. These roller groups 14 are supported by bearings 16 on a fixed support plate 15, and further supported by bearings 18 on a movable support plate 17, so that the imaginary peripheral surface of the axis of the roller group forms a tapered frustoconical surface. support Next, the tip of the roller 14 is twisted in the direction of roller rotation or in the opposite direction to displace the group of rollers 14, and then fixed in a predetermined position with a tightening bolt 19.

The tube material is wound in a helical direction around 14 groups of rollers of this tube forming machine, and the tube material is overlapped and integrated with the end edge surface of the thin sheet as shown in FIGS. 1 and 4. became
The cross section of the thin sheet 2 made of soft synthetic resin has a substantially uniform thickness;
It has a wedge-shaped shape with a tapered slope where the thickness gradually decreases between the reinforcement body width AB. The opposite side has the same shape, and has a flat, substantially parallelogram shape.

When winding of this tube material around the group of rollers 14 of the tube forming machine is started, since the tube material is in an uncured state, the cross section of the tube has a polygonal shape as shown in FIG. Group contact is large. In addition, the slope part of the thin sheet (
(wedge-shaped part) The overlap point where the comrades overlap is located at the lower part of the bottom of the hard reinforcement (between the reinforcement and the roller). It is well pressed by the reinforcing body on the roller group and welded. Adhesion is sufficiently performed.

While welding the tube material like this. Next, the uncured tube 20 that is being formed is placed on a forming machine and cooled by cooling water 22 from a cooling device 21.

As cooling progresses. As the hard synthetic resin reinforcement gradually hardens, the cross section of the formed tube changes from a polygonal shape to a circular shape as shown in FIG. At this time, a difference in thermal shrinkage occurs between the hard synthetic resin reinforcement 3 and the soft synthetic resin thin sheet 2 due to cooling, and the thin sheet 2 has a higher shrinkage rate, so it tends to shrink inward (deform)6. Since the 14 groups of rollers of the tube forming machine are arranged in a conical shape, the 6 thin sheets shrink without being disturbed by the rollers, thereby producing a stretchable flexible hose 23 in which the inside of the tube is concave. . The difference in heat shrinkage between the thin sheet of soft synthetic resin in the uncured tube and the reinforcing body of hard synthetic resin causes the dent inside the tube to be large, but the thin sheet cools relatively faster than the reinforcing body during cooling. If you do that, you will get the effect. Cooling with water or cold water. Airflow 6 Partial blowing of cold air. Cooling may be performed by pouring water or cooling water.

When the length of the tapered slope part (wedge part) at both ends of the cross section of the thin sheet is approximately the same length as the base width of the reinforcing body.
The pressure of the reinforcing body works more effectively, resulting in better welding.

6) When the cross-sectional shape of the reinforcement body is round or rounded, the length of the sloped part of the thin sheet is selected as the base width based on the diameter of the cross-section of the reinforcement body or something similar thereto. . Although the sloped portions of the thin sheets are overlapped and welded to each other, there is less unevenness in the thickness of the tube wall portion than when six thin sheets of the same thickness are overlapped and welded, and the six-way welding can be performed effectively.
In addition, since the inclination directions of the sloped portions at both ends of the thin sheets are substantially parallel, there is little thickness unevenness after overlapping and it is easy to weld. direction 6
It is also possible to manufacture a stretchable flexible hose using a thin sheet of soft synthetic resin as the pipe wall and a hard reinforcing body coated with soft synthetic resin on the outside to an extent that does not affect the difference in heat shrinkage. Good results can be obtained when welding the sheet or thin sheet to the reinforcing body.

In the above-mentioned embodiment, the tube material extruded from the extruder is made by integrating the thin sheet of soft synthetic resin that forms the tube wall and the reinforcing body of hard synthetic resin in the tie of the extruder, and then passing the tube material through the rollers of the tube forming machine. Wrap around the group. The overlapping parts of the thin sheets are pressed by a reinforcing body and welded and bonded.

The method of manufacturing a stretchable synthetic resin flexible hose of the present invention does not use special uneven rollers of a tube forming machine, winding endless strings to create dents, or using pressure rollers. Group arrangement 6 Shape of pipe material. By a completely simple method that combines tube cooling, the same tube materials are sufficiently welded, no peeling occurs, and a stretchable flexible hose with extremely high elasticity in which the tube wall is recessed inside can be easily obtained. This is the manufacturing method.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of the manufacturing apparatus in the method for manufacturing a stretchable synthetic resin flexible hose of the present invention, and FIG. 2 is a cross-sectional side view taken along A-A of the manufacturing apparatus shown in FIG. 1. , 3rd
The figure is a side view of the manufacturing equipment, and Figure 4 is a cross-sectional view of the tube material. FIG. 5 shows another embodiment of the tube material in which the reinforcing body has a circular cross section. 2...Thin sheet. 3...Reinforcement body 61
4... Roller group, 20... Uncured tube. 21... Cooling device, 23... Stretchable flexible tube.

Claims (1)

[Claims] 1. When manufacturing a hose by spirally winding a band-shaped tube material consisting of a thin sheet of soft synthetic resin and a reinforcing body of hard synthetic resin, which will become the tube wall part, and heat-sealing the edges, the thin sheet of soft synthetic resin is A reinforcing body made of hard synthetic resin is integrated along the length direction on the edge surface of the sheet, and the cross section of the thin sheet is wedge-shaped over a length approximately equal to the width of the reinforcing body at the lower part of the reinforcing body. The tube material is melted and extruded to form a substantially parallelogram shape whose thickness is gradually reduced and the thickness is also gradually reduced at the diagonal of the part, and a plurality of rotating rollers with smooth surfaces are formed by the axis of the tube material. For a group of rollers of a forming machine, the rollers of a forming machine are arranged such that the virtual circumferential surface formed by the tube is a tapered truncated conical surface, and each roller axis is displaced in the same direction in the circumferential direction at the tapered end of the circumferential surface. While continuously winding the material,
After the wedge-shaped parts of the thin sheet are overlapped and heat-sealed at the bottom of the reinforcing body part of the tube material, the uncured tube that is being formed is cooled on the rollers of the forming machine, thereby reinforcing it. A method for producing a stretchable flexible hose made of synthetic resin, characterized by contracting the tube wall between the bodies and recessing the tube inside the tube.