JPS6240178B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention involves heating and softening a thermoplastic synthetic resin hose to reduce bending strain while it is set in a curved pipe-shaped shape forming cavity formed in a mold. remove,
The present invention relates to a method for bending a hose, which is then performed by cooling and solidifying.

<Prior Art> When a synthetic resin hose is used as piping for fluid equipment, it is necessary to bend it in advance to avoid interference with other parts. This bending method is described, for example, in Japanese Patent Application Laid-Open No. 17119/1983, in which a synthetic resin hose (plastic pipe) is bent at room temperature along a bending die, and then the bending strain is removed by heating. , a method of cooling after this strain removal is described.

<Problems to be solved by the invention> However, the method for bending the resin hose described above is
If you try to use a mold that can be cooled, it is necessary to repeatedly raise and cool the mold, and it takes time to raise and cool the mold to each set temperature, resulting in poor productivity and a large amount of energy. Problems arise such as losses are likely to occur and the mold is likely to be damaged.

<Means for Solving the Problems> The gist of the present invention is to remove bending strain by heating and softening a thermoplastic synthetic resin hose set in a curved pipe-shaped shape forming cavity formed in a mold. In the method of subsequent cooling and solidification followed by bending, heating softening is performed by heating a mold, and cooling and solidification is performed by passing a refrigerant through the hose while the entire or half of the outer circumference of the hose remains heated by the mold. It's in the bending method for resin hoses.

<Example> Hereinafter, the method of the present invention will be explained based on illustrated examples. Here, explanation will be given by taking as an example a case where a synthetic resin hose H provided with eye joints J, J at both ends is bent three-dimensionally as shown in FIG. 4, but the present invention is not limited to this.

An example of the apparatus used in this invention is shown in FIGS. 1 and 2. A mold 1 having a rectangular parallelepiped shape includes a receiving mold 5 having a groove that forms a bent pipe-shaped shape-imparting cavity 2, and a holding mold that closes the opening surface in the longitudinal direction of the groove to form the shape-imparting cavity 2 when the mold is closed. 6, presser die 6
is connected to the receiving mold 5 with a hinge 7 on the upper surface, and the presser mold 6
Opening and closing operations can be performed using a handle 8 formed on the front surface of the door. Mold (receiving mold and presser mold) 1
Cartridge heaters 9, which are located on both sides of the shaping cavity 2 and are equipped with a temperature control mechanism for raising the temperature of the mold, are embedded in the mold. In addition, air nozzle-equipped joint support stands 11 and 12 are disposed close to each outer wall of the mold 1 that constitutes the opening surfaces at both ends of the shape-imparting cavity 2.
The air nozzle 11a of one joint support is connected to a blower or the like (not shown) via an air pipe 13 so that air can be blown into it, and the air nozzle 12a of the other joint support is equipped with a silencer 14 and is capable of discharging air. ing. Furthermore, each joint support stand 1
Joint holding clamps 15 and 16 corresponding to 1 and 12
is installed. Note that 18 in the figure is a heat insulating material.

Next, the method of the present invention using the above device will be explained. Note that the values in parentheses are for nylon hoses.

The temperature of the mold 1 is controlled to a predetermined temperature (approximately 170° C.) by turning on the cartridge heater 9. In this state, the hose H (preheated to soften it if necessary) is manually fitted into the groove constituting the shaping cavity 2 of the receiving mold 5, and the joints J and J are fitted as shown in FIG. It is fixed to the joint supports 11 and 12 using the joint holding clamps 15 and 16, and the mold is further closed and set in the shape-forming cavity 2. After leaving it in this state for a predetermined time (20 seconds) to heat and soften it, operate a blower or the like to supply cooling air (room temperature) from the air nozzle 11a into the hose H for a predetermined time (5 seconds when the mold is closed, and when the mold is open). (for 10 seconds) to cool and solidify. Next, stop the air and clamp 1
5 and 16 and take out the bent hose H as shown in FIG.

In the above hose cooling and solidification process, the hose H
The outside surface is heated in the mold, but if the inside part is cooled and solidified, it will retain its bent shape even after being removed from the mold, and then the outside part will be completely solidified by air cooling on the outside by leaving it at room temperature, and the hose can be used. Even if it is reheated (to around 80℃) over time, it will no longer deform (opening of the bent part). In addition, hose H
If the air flow time is increased, the air can be stopped immediately after the mold is opened and the hose H can be removed from the mold.

The method of the present invention is not limited to the above-mentioned embodiments, and can be applied to hoses with a joint at one end or without joints at both ends, and an air blowing nozzle may also be installed inside the mold. Also, instead of a cartridge heater, water vapor,
Water or the like can also be used as a refrigerant, depending on the material of the hose.

<Actions and Effects of the Invention> The method for bending a synthetic resin hose of the present invention includes:
Since the hose is cooled and solidified while the entire or half circumference of the outer surface of the hose is heated in the mold, there is no need to repeatedly raise and cool the temperature of the mold. Therefore, productivity is greatly improved, energy loss is reduced, and damage to the mold due to thermal shock does not occur. Furthermore, in the case of a hose with a joint, the joint part can be avoided from being directly heated, so there is no problem of a decrease in the fastening force between the joint and the hose due to heating and cooling together.

[Brief explanation of the drawing]

Examples of drawings illustrate this invention. FIG. 1 is a perspective view of a hose bending device used in this invention, FIG. 2 is a sectional view of the mold showing the placement position of the cartridge heater when the mold is closed, and FIG. The figure is a partial sectional view showing a state in which the joint part of the hose is fixed to the joint support base, and FIG. 4 is a perspective view of the hose after the bending process is completed. 1... Mold, 2... Shape imparting cavity, 5... Receiving mold, 6...
Presser mold, 9... Cartridge heater, 11, 12...
Joint support stand with air nozzle, 15, 16...joint holding clamp.

Claims (1)

[Claims] 1. A method in which a thermoplastic synthetic resin hose is set in a curved pipe-shaped forming cavity formed in a mold, and is heated and softened to remove bending strain, and then cooled and solidified to perform a bending process, A method for bending a synthetic resin hose, characterized in that the cooling and solidification is performed by passing a refrigerant through the hose while the entire or half circumference of the outer surface of the hose is heated with a mold.