JPH11129325A - Working method for flexible vinyl chloride tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably perform the working without spoiling the strength and the shape of the worked part when a bending work of a flexible vinyl chloride tube or an end part internal diameter expanding work for the tube is to be performed. SOLUTION: After inserting a string-form core member 2 which has flexibility, and keeps a flexible state in a previously determined heating temperature range, in this flexible vinyl chloride tube 1, the flexible vinyl chloride tube 1 is dipped in an oil 5 of which the firing temperature is 190 deg.C or higher, and which is heated to a temperature of 120-180 deg.C, and heated under a state wherein a bending pressure is being applied to the bending work part, and the flexible vinyl chloride tube 1 is plastically deformed, and right after the completion of the immersion heating in the oil 5, the tube 1 is dipped in a cooling water 8 for a specified period of time under a state wherein the bent shape is being kept, and the bent state is fixed, and then, the string-form core member 2 being inserted in the flexible vinyl chloride tube 1 is removed to perform the bending work for the flexible vinyl chloride tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for bending a tubular soft vinyl chloride tube (including a non-migratory soft vinyl chloride tube) to a required angle or expanding (expanding) an end portion. It is about. Soft vinyl chloride tubing is suitable for piping freely between parts, equipment, and liquid tanks, but the flat parts of the system or equipment that hit corners of obstacles or parts, etc. Therefore, it is extremely important to bend in advance along the pipe shape because there is a risk of obstructing the flow of the pipe or the like or preventing the flow. By performing this bending, the safety or miniaturization of the system or the device can be achieved.

[0002]

2. Description of the Related Art Heretofore, a flexible polyvinyl chloride tube subjected to this bending process is, for example, a DPE (developing printing).
It is used in a part of a chemical apparatus, a copying apparatus, and the like, such as a pipe for flowing a developer and the like of a developing apparatus of enlarging. This is a soft vinyl chloride tube (hereinafter "tube")
Abbreviated. ) Can be easily bent to a required angle by heating and is suitable for bending. In the conventional bending method of this tube, an operator approaches the bending portion to a gas burner or hot air one by one and applies a bending pressure to the processing portion by heating while rotating the tube so that a required angle is obtained. In general, bending was performed. In the specification of the present application, the term "soft vinyl chloride tube" is used, but it may be called a soft vinyl chloride hose, a polypin hose, or the like as another name.

[0003]

However, in the conventional bending method described above, it is difficult to uniformly apply heat to the peripheral surface of the bent portion of the tube. Was not constant, there was a very thin part or a trace of burning, and when the heating was uneven, breakage cracks sometimes occurred in the bent part during use. Therefore, a conventional tube having a large wall thickness must be used to ensure the safety of bending. However, increasing the thickness of the tube increases the outer diameter of the tube, raising the material cost and hindering downsizing of an apparatus using the tube. Further, there is a problem in that the bending process takes a long time due to the thick wall of the tube, which hinders the efficiency of the processing step.

Further, when connecting a tube to a piping port of a counterpart device in order to conform to the tube shape of the tube, it is necessary to use a thick tube in which the inside diameter of one tube matches the outside diameter of the other tube. However, as described above, this is a factor that hinders downsizing of the apparatus using the tube. The present invention makes it possible to make the thickness of the bent portion of the tube substantially uniform, and to bend a plurality of tubes at the same time depending on the thickness and the bent shape of the tube. A bending method that can increase the reliability of maintaining the strength and shape of the tube, and a process that expands the inner diameter of the end of the tube can be performed. An object of the present invention is to provide a method of expanding the inner diameter of a tube end portion, which has a function and can reduce the size of an apparatus using a tube.

[0005]

According to a first aspect of the present invention, there is provided a method for processing a soft vinyl chloride tube, which comprises a flexible vinyl chloride tube which is flexible and maintains a soft state in a predetermined heating temperature range. After inserting the core member, the flexible vinyl chloride tube is subjected to a bending pressure at a bending portion thereof, and the ignition temperature is 190 ° C. or more and 120 ° C. to 18 ° C.
Immersion heating for a required time in oil heated to a temperature of 0 ° C. for plastic deformation to a required shape, and immediately after completion of the immersion heating in the heating oil, immersion in the cooling water for a required time while maintaining the bent shape and bending. The processing state is fixed, and the string-shaped core member inserted into the soft vinyl chloride tube is removed, or the string-shaped core member is removed while the soft vinyl chloride tube is being cooled by cooling water, and bending is performed. Let's fix the state,
The flexible vinyl chloride tube is bent.

The method for processing a soft vinyl chloride tube according to the second invention of the present application is a method for inserting a cord-like core member which is flexible and maintains a soft state in a predetermined heating temperature range into the soft vinyl chloride tube. Immersing and heating the bent portion of the flexible polyvinyl chloride tube in an oil having an ignition temperature of 190 ° C. or higher and heated to a temperature of 120 ° C. to 180 ° C. for a required time so as to be plastically deformed; Immediately after the completion of the immersion heating, the soft vinyl chloride tube is plastically deformed by being fitted into a bending mold having a required bending shape, and the cord-shaped core member inserted into the soft polyvinyl chloride tube while being fitted into the bending mold. Then, the bent state is fixed by immersion in cooling water for a required time, or the string-shaped core member is removed during cooling of the soft polyvinyl chloride tube with the cooling water to fix the bent state. Allowed to, in which so as to occupy perform bending of the soft polyvinyl chloride tube.

According to a third aspect of the present invention, there is provided a method for processing a flexible vinyl chloride tube, wherein a required portion of an inner diameter expansion end of the flexible vinyl chloride tube has an ignition temperature of 190 ° C. or more and 120
C. to 180.degree. C. for a required time soaked and heated in oil for a required time to be plastically deformed. After plastic deformation by inserting into the fitting state, the heated portion is immersed in cooling water for a required time to fix the expanded inner diameter state, and then the open mold is removed from the expanded inner diameter end of the soft vinyl chloride tube. The inner diameter of the end of the soft vinyl chloride tube is expanded.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the process chart shown in FIG. In FIG. 1A, reference numeral 1 denotes a soft vinyl chloride tube to be processed, which is cut to a required length. Reference numeral 2 denotes a flexible cord-like core member having a substantially circular cross section which is inserted into the inside of the tube 1 to prevent the tube 1 from being deformed. You. As the substance, for example, silicon or synthetic rubber is suitable. The cord-shaped core member 2 has an outer diameter Φ1 and an inner diameter Φ
2. When the outer diameter of the cord-shaped core member 2 is Φ3, Φ2> Φ3
Need a relationship. For example, when Φ1 is 14 mm and Φ2 is 10 mm, Φ3 is suitably about 8.5 to 9.5 mm.
FIG. 1B shows a state where the cord-like core member 2 is inserted into the tube 1. In the case where bending is performed manually as shown in FIGS. 1C and 1D, the work becomes easier if a mark 3 that can be easily confirmed as a mark is provided at the center of the inside of the bending position.

FIG. 1 (c) is a schematic view of a step of bending the tube 1. Reference numeral 4 denotes a heating oil tank in which oil 5 is put. The oil 5 is heated at a constant temperature by a heat source 6 such as electricity or gas. Heated. The tube 1 in which the cord-shaped core member 2 shown in FIG. 1B is inserted into the oil 5 is immersed in the oil 5 for a required time by applying a bending pressure centering on a predetermined position. Thereby, the tube 1 is in a state where it can be plastically deformed. Although this operation shows a pattern performed manually, automation can be achieved by an automation device. In the case of manual operation, plural pieces can be bent at the same time. However, when a special jig is not used in the case of a manual operation, it is preferable to apply the present invention only to a case where the bending angle is processed to 90 °. The temperature of this oil 5 is 12
A range of 0 ° C to 180 ° C is appropriate. This is 120 ° C
At the following temperatures, there is a problem that even if the bent shape is stabilized by cooling described in a later step, the function of returning the shape to the original shape works, and the shape is not stabilized. 180 ° C
This is because if the above occurs, the tube 1 is deteriorated, and the surface may become cloudy or may be broken during use.

The temperature of the oil 5 is from 120 ° C. to 180 °
In the temperature range of ° C., the purpose of causing the tube 1 to be plastically deformed or in a plastically deformed state is achieved. However, from the viewpoint of stability after processing of the tube 1 and reliability of quality, the optimal temperature for plastic deformation is 140 ° C. It is desirable to set the temperature to 155 ° C. The oil 5 has an ignition temperature of 190 ° C. or higher, and is suitable for use as the oil 5 such as therm oil and edible oil. In particular, from the experimental results in which the ignition temperature and the smell of the oil 5 when heated are taken into account, the results that the therm oil 32 is good are obtained. The portion of the tube 1 to be bent is immersed in the heated oil 5, and the immersion is performed by applying a bending pressure so that the processed portion has an angle close to the reference bending angle. The immersion time varies depending on the temperature of the oil 5, the outer diameter and the wall thickness of the tube, and the like. If the tube 1 is as described above, the plastic deformation is stabilized by immersion for about 45 seconds to 1 minute.

FIG. 1D is a schematic view of a process for fixing the bending of the tube 1. The tube 1 heated by the oil 5 is taken out of the oil tank 4 and is bent to a required bending angle. Immediately as it is, it is immersed in the cooling water 8 of the cooling water tank 7 and cooled to fix the bent state. The cooling time is stabilized in about 45 seconds to 200 seconds. The water temperature of the cooling water 8 is preferably about 20 ° C. when the work is performed manually, but may be 10 ° C. or less when the cooling water 8 is fitted in a bending mold to be described later. is there.
The bending angle of the tube 1 is preferably processed to be slightly smaller than the reference bending angle. For example, when the reference bending angle is 90 °, it is preferably about 80 ° to 87 °. This is because the stress applied to the bent portion of the bent tube 1 is reduced by applying pressure in the direction of returning the bending angle, rather than by applying further bending pressure in the bending direction. After the cooled tube 1 is taken out of the cooling water tank 7, the string-shaped core member 2 is removed, and the tube 1 is immediately washed with, for example, a hydrocarbon-based cleaning agent to remove the oil 5 adhering to the inside and outside of the tube 1. After removing sufficiently, and if necessary, after washing with a detergent, foreign substances are removed by washing with water. The removal of the cord-shaped core member 2 from the tube 1 may be performed during the cooling of the tube 1.

[0012]

EXAMPLE Depending on the bending shape of the tube 1, a portion to be bent is immersed in a heating oil 5 for a required time to be heated and plastically deformed. It is effective to immerse in the cooling water 8 and fix it in the obtained state. 2 and 3 show the bending mold. 2A and 2B show an example of a fitting-type bending die. FIG. 2A is a plan view, and FIG. 2B is a side view. A bending die 10 having a bent shape of the tube 1 is formed on a flat plate 9. 1 shows a state in which the tube 1 into which the cord-shaped core member 2 is inserted is fitted. 3A and 3B show an example of a pressurized mold. FIG. 3A is a plan view of an upper and lower mold, FIG. 3B is a side sectional view thereof, and FIG. FIG. 2 is a side cross-sectional view of a state where the finished tube 1 is sandwiched between upper and lower molds.
In FIG. 3, reference numeral 11 denotes a lower die (stand) and 12 denotes an upper die (holding type).
Thus, the holding groove 13 of the tube 1 is formed on the opposing surfaces of both molds. When the tube 1 is sandwiched between the holding grooves 13, the depth of the holding grooves 13 needs to be formed so that a slight gap is formed between the upper and lower molds. The pressing force between the upper and lower molds for bending the tube 1 is 2
A pressure of about 0 to 30 kg / cm ² is required.

When the mold shown in FIG. 2 or 3 is used, R (radius) of the bent portion is specified as R1, R2, or the bending angle is specified other than 90 °, or This is effective when the bending position is close to the end of the tube 1 or when the bending position is continuous or close to two or more places. In addition, in the case of the pressurized type shown in FIG. 3, there are a left-right type, a top-bottom left-right type, and a simultaneous type other than the top-bottom type. In the case of using this bending die, the portion to be bent of the tube 1 is immersed in the heating oil 5 for a required time to be plastically deformed, and then immediately fitted into the bending die. , And immersed in cooling water 8 for a required time to fix the shape. Cleaning after cooling is the same as the above-described cleaning when bending is performed manually. In the above description, the timing of extracting the cord-shaped core member 2 from the tube 1 is performed before cooling. However, the use of a bending mold is generally used because the shape of the tube 1 is complicated. It is intended to be extracted in a state that is easy to do. Therefore, if the shape of the tube 1 is simple, the string-shaped core member 2 is connected to the tube 1 during or after cooling.
It may be taken out from.

Next, a case where the inner diameter of the end of the tube 1 is expanded will be described with reference to FIG. FIG. 4A is a side view of the open die 14 for expanding the inner diameter of the end of the tube 1 and the end 15 of the tube 1.
The top surface is provided as a cylindrical body 18 having a peripheral surface formed as a tapered portion 17. This opening type 1
As the material of No. 4, for example, a plastic resin or the like is used. First, the end 15 of the tube 1 is immersed in the same heating oil 5 as described above for a required time to be heated and plastically deformed. Then, the end 15 is immediately pushed into the open mold 14 so that the end 15 is expanded. By immersing the tube 1 in the cooling water 8 of the cooling water tank 7 for a required time while being plastically deformed, the end 15 of the tube 1 can be expanded to a required inner diameter. In this case, the length L of the heated portion of the end 15 immersed in the heating oil 5 needs to be slightly longer than the length L1 of the cylindrical body 18 of the opening die 14. After cooling, pulling out and cleaning from the opening mold 14 is the same as described above.

Next, an example of processing a tube obtained by bending the tube or expanding the inner diameter of the end of the tube according to the present invention will be described with reference to the side views shown in FIGS. The tube 1 has an inner diameter of 12 mm and an outer diameter of 16 mm.
This is an example of a sample having a dimension of mm, and the unit of the dimension of each part is millimeter (mm). FIG. 5 (a) shows a tube 1 bent in an inverted U-shape, in which both ends A and B are bent by about 90 °, and this shape can be performed either manually or using a bending die. . FIG. 5B shows that one end A is about 9
The other end B is bent in an arc shape in the opposite direction at 0 °. The arcuate portion of this shape is the processing accuracy using a bending die. FIG. 5C shows that one end A is bent into a crank shape using a bending die, and the other end B is bent.
Is the outer diameter before processing using an open die (16mm)
It has been expanded.

The shape of the tube 1 shown in FIG.
As can be understood from the perspective view of FIG.
And the other end B is bent at about 90 ° in a direction rotated by 90 ° with respect to the one end A. This bending is dimensional accuracy when both ends are bent using a bending die. FIG. 6B is a perspective view of FIG.
FIG. 6C is similarly viewed from the direction of arrow Y. As described above, the dimensional accuracy by the bending method of the tube 1 according to the present invention is extremely high, and it is possible to obtain an accuracy several times or more as compared with a conventional product. Further, according to the working method of the present invention, the reduction rate of the wall thickness of the bent portion of the tube 1 is about 20%, and the reliability as a piping member can be sufficiently achieved.

[0017]

As described above, according to the method for processing a flexible vinyl chloride tube of the present invention, in the case of bending a tube, a decrease in wall thickness of a bent portion is reduced, and deformation after bending is reduced. Since the number is small, the strength of the bent portion is high, the dimensional accuracy of the interval between bending positions is significantly improved, and a highly reliable bent tube can be obtained. Also,
Since bending can be performed using a mold such as a fitting type or a pressure type, it is possible to perform a bending process of a complicated shape. Further, since the inner diameter of the end portion of the tube can be expanded, the tube can be used as a tube having a different diameter. That is, since tubes of the same diameter can be used in combination,
An excellent effect is obtained, for example, it is possible to prevent the tube portion from becoming large due to the use of tubes having different diameters (thick) at the joint portion as in the related art.

[Brief description of the drawings]

FIG. 1 is a process diagram showing one embodiment of a bending process by a tube processing method of the present invention.

FIG. 2 is a schematic view showing an example of a bending die used in a bending step of the present invention.

FIG. 3 is a schematic view showing another example of a bending die used in the bending step of the present invention.

FIG. 4 is a schematic view showing an example of an open mold in a case where an end portion is expanded by the method for processing a tube according to the present invention.

FIG. 5 is a side view showing an example of a tube processed by the processing method of the present invention.

FIG. 6 is a perspective view showing another example of a tube processed by the processing method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vinyl chloride tube (tube) 2 String-shaped core member 3 Mark 4 Heating oil tank 5 Oil 6 Heat source 7 Cooling water tank 8 Cooling water 9 Flat plate 10 Bending mold 11 Lower mold 12 Upper mold 13 Holding groove 14 Open mold 15 End of tube Part 16 Base part 17 Column part 18 Taper part

Claims (8)

[Claims] After inserting a string-shaped core member which is flexible and maintains a soft state in a predetermined heating temperature range into a flexible polyvinyl chloride tube, a bending pressure is applied to the bent portion of the flexible polyvinyl chloride tube. When the ignition temperature is 19
0 ° C. or higher and immersed and heated in oil heated to a temperature of 120 ° C. to 180 ° C. for a required time to plastically deform into a required shape. While maintaining the state, immersion is performed for a required time to fix the bending state, and the string-shaped core member inserted into the soft polyvinyl chloride tube is removed, or the string is cooled while cooling the soft vinyl chloride tube with cooling water. A method for processing a soft vinyl chloride tube, wherein the bent state is fixed by removing the core member, and the soft vinyl chloride tube is bent. 2. After inserting a cord-shaped core member which is flexible and maintains a soft state in a predetermined heating temperature range into a flexible polyvinyl chloride tube, the ignition temperature of the bent portion of the flexible polyvinyl chloride tube is reduced. Immediately after immersion heating in oil heated to a temperature of 120 ° C. to 180 ° C. at a temperature of 190 ° C. or more and a temperature of 120 ° C. to 180 ° C. to form a plastically deformed state, immediately after the completion of immersion heating in the oil, the soft vinyl chloride tube After being fitted in a bending mold having a bent shape and plastically deformed, the string-shaped core member inserted in the soft vinyl chloride tube in a state of being fitted in the bending mold is removed, and then immersed in cooling water for a required time to bend. The bending state of the flexible polyvinyl chloride tube is performed by fixing the processing state or by removing the cord-shaped core member during cooling of the soft vinyl chloride tube with cooling water and fixing the bending state. A processing method for soft vinyl chloride tubes. 3. A required portion of the inner diameter expanded end of the soft vinyl chloride tube is heated to an ignition temperature of 190 ° C. or more and 120 ° C.
Immersed and heated in oil heated to a temperature of 180 ° C. for a required time to form a plastically deformed state. After being inserted and plastically deformed, and in the inserted state, the heating portion is immersed in cooling water for a required time to fix the inner diameter expanded state, and then the open mold is removed from the inner diameter expanded end of the soft vinyl chloride tube, A method of processing a soft vinyl chloride tube, which expands an inner diameter of an end portion of the soft vinyl chloride tube. 4. After inserting a string-shaped core member having flexibility and maintaining a soft state in a predetermined heating temperature range into a flexible polyvinyl chloride tube, the ignition temperature of the bent portion of the flexible vinyl chloride tube is reduced. Immediately after immersion heating in oil heated to a temperature of 120 ° C. to 180 ° C. at a temperature of 190 ° C. or more to make it plastically deform, the bending process of the flexible polyvinyl chloride tube immediately after the completion of the immersion heating in the oil Bending pressure is applied to the portion to plastically deform it into a required shape, and the bent shape is fixed by immersing it in cooling water for a required time while maintaining the bent shape. The core member is removed, or the string-shaped core member is removed during cooling of the soft polyvinyl chloride tube with cooling water, and the bending state is fixed. The processing method of the soft vinyl chloride tube to be performed. 5. The thermal oil used for immersing and heating the flexible vinyl chloride tube is a therm oil.
A method for processing the flexible vinyl chloride tube described in the above. 6. The soft vinyl chloride tube is heated by setting the heating temperature of the oil for immersing and heating the soft vinyl chloride tube to 140 ° C. to 155 ° C. Processing method of soft vinyl chloride tube. 7. The method for processing a flexible vinyl chloride tube according to claim 1, wherein said cord-shaped core member inserted into said flexible vinyl chloride tube is made of silicon or synthetic rubber. 8. The method for processing a flexible vinyl chloride tube according to claim 3, wherein the open mold into which the heating portion at the inner diameter expansion end of the flexible vinyl chloride tube is fitted is made of a plastic resin.