JP4332332B2 - Bending method for piping with plastic protective caps for piping - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a bending method of a pipe fitted with plastic protective cap for the pipe to protect the joint of the pipe for supply of fluid such as fuel or oil in automobiles and machinery, protection cap The pipe is positioned with the pipe mounted, or the pipe is held by a vendor chuck so that the pipe can be bent with high accuracy.
[0002]
[Prior art]
Conventionally, when connecting metal or resin pipes such as fuel pipes of automobiles to the connection destination, rubber hoses have been used. However, in recent years, connection of pipes using quick connectors etc. has become the mainstream and easier. It is possible to connect pipes quickly and obtain highly reliable airtightness. When transporting or storing the pipe before assembling, the outer periphery of the insertion section should be chlorinated so that the plating film or resin coating film on the insertion section of the pipe quick connector will not be damaged and airtightness will be reduced. A bottomed protective cap made of vinyl was attached.
[0003]
This protective cap made of vinyl chloride has many opaque products such as black, and has a horn-like tension piece protruding in the inclined direction continuously at the bottom, and this horn-like tension piece is held by fingers or a machine. By pulling, the protective cap can be removed from the piping.
[0004]
And when bending pipes in a bending line, the horn-shaped pulling piece becomes an obstacle when the protective cap is attached, making it difficult to obtain a bending plane by the vendor, and the pipe tip is used as a reference. Since it is difficult to accurately determine the clamp position and the bending position, the protective cap was once removed from the pipe and positioned to bend the pipe. After this bending process was completed, the protective cap was reattached to the pipe, and the product was stored and transported to the delivery destination.
[0005]
[Problems to be solved by the invention]
However, it takes an enormous amount of time and is inefficient to perform the work of removing and attaching the protective cap on thousands and tens of thousands of pipes in the bending line. In addition, when a protective cap is used for a pipe provided with an annular bulge, it is a processed pipe or an unprocessed pipe of the annular bulge through an opaque vinyl chloride protective cap such as black. However, it was difficult to find it visually and there was a risk of producing defective products. In addition, vinyl chloride has a problem of having a great influence on the environment. Also, since the pipe insertion part is strongly held by the vendor's chuck, there is a possibility of damaging the plating film of the pipe insertion part and particularly the resin coating film disposed on the upper layer, such as a quick connector seal member, etc. The air tightness may be deteriorated, leading to fuel leakage and the like. In addition, since the pulling piece protrudes three-dimensionally from the protective cap in an oblique direction, there is a possibility that the bulkiness may occur and the storage performance may be deteriorated, or the protective cap may be inadvertently detached from the piping due to stimulation during transportation. .
[0006]
The present invention is intended to solve the above-described problems. The pipe can be attached to the chuck of the vendor with the protective cap attached, and the position of the tip of the pipe can be specified accurately. It is possible to position the bending position with reference to the portion with high accuracy. Thus, by enabling accurate bending of the pipe with the protective cap attached, it is possible to eliminate the trouble of attaching and detaching the protective cap, increase productivity, and improve product quality. In addition, it prevents damage to the plating film or resin coating film on the pipe due to the vendor's chuck, obtains a highly reliable airtightness with the connection destination of the pipe such as a quick connector, and causes problems such as fuel leakage in the equipment. Can be satisfactorily prevented. In addition, the protective cap is economically manufactured from inexpensive materials, and can be used and disposed of with little influence on the human body and the environment.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the first invention of the present application has a uniform thickness bottom perpendicular to the axial direction of the pipe at one end of the cap body of the resin material protective cap having the other end as an insertion port of the pipe. By forming a wall and abutting the tip of the pipe inserted from the insertion port against the bottom wall, the tip of the pipe can be specified from the outside, and the outer periphery of the cap body attached to the pipe is Resin protective cap for piping, characterized in that piping is fixed through a cap body by holding with a chuck, and bending of the piping is performed by the vendor based on a specified tip portion of the piping This relates to a method of bending a pipe fitted with the.
[0008]
The cap body is formed of a small-diameter portion on the bottom wall side and a large-diameter portion on the insertion port side, and a pipe provided with an annular bulge is inserted from the insertion port, and the tip of the pipe is connected to the bottom wall. You may arrange | position the cyclic | annular bulging part of piping to a large diameter part in the state contact | abutted to.
[0009]
[Action]
The present invention is configured as described above. When a protective cap is attached to a pipe, the front end of the pipe hits the bottom wall provided perpendicular to the axial direction, and the front end and the outer peripheral surface of the pipe are protected by the protective cap. In addition, it is possible to prevent damage to the plating film or the resin coating film of the pipe due to stimulation when the pipe is stacked or transported in large quantities. In addition, it has a symmetrical shape with a U-shaped cross-section without providing diagonally protruding tension pieces as in the past, so that more orderly stacking and alignment inspections are possible, preventing bulkiness and storing and transportability. In addition, the protective cap can be prevented from accidentally falling off.
[0010]
In order to bend the pipe, the pipe is fixed by holding the outer periphery of the protective cap with a vendor chuck. In the prior art, since the bottom wall of the protective cap is inclined, it is not possible to obtain a bending plane, and it is necessary to remove the protective cap from the pipe once and perform bending, and then attach the protective cap again. Yes, because the protective cap was attached and detached for each pipe, it was inefficient.
[0011]
However, in the present invention, the bottom wall against which the tip of the pipe is abutted is formed perpendicularly to the axial direction of the pipe and has a uniform thickness, so that the bottom wall is abutted against the stopper of the chuck and the pipe The position of the bending plane can be determined with high accuracy based on the tip. In addition, even when the tip of the pipe is not in contact with the bottom wall due to vibration during transportation, the tip is securely pushed by pushing the pipe toward the bottom wall while the bottom wall is in contact with the stopper of the chuck. It can be brought into contact with the bottom wall.
[0012]
Therefore, with the protective cap attached, the bending position can be determined with high accuracy based on the position of the tip of the pipe, and the pipe can be bent. It is possible to greatly improve the productivity in the line and to obtain a high-quality product with a uniform bending position for each pipe. In addition, since the piping is held via the protective cap, the plating film or resin coating film of the insertion portion of the piping is not damaged by the chuck, and the airtightness between the quick connector seal member and the piping is maintained. It is possible to prevent problems such as fuel leakage. In addition, it is not necessary to remove the protective cap from the insertion section of the pipe until the pipe is connected with a quick connector, etc., as well as during transportation, bending, and transportation after bending. The insertion portion of the pipe can be protected, and a high leakage prevention effect of the pipe can be obtained by an excellent damage prevention effect such as a plating film or a resin coating film of the insertion portion.
[0013]
In addition, in the case of a pipe having an annular bulge on the outer periphery, the cap body is formed of a small diameter part on the bottom wall side and a large diameter part on the insertion port side, and the annular bulge part is disposed on the large diameter part. Thus, the annular bulging portion may be protected from impact. Then, the pipe provided with the annular bulge portion is inserted from the insertion port, and the dimension is such that the annular bulge portion of the pipe is positioned at the large diameter portion in a state where the tip portion of the pipe is abutted against the bottom wall. Make sure that the tip of the pipe is in contact with the bottom wall. Further, the cap body provided with the large diameter portion and the small diameter portion may be used for piping having a smooth outer peripheral surface without providing an annular bulging portion. The cap body can be easily removed from the pipe by hooking a fingernail or a tool into the gap.
[0014]
In addition, if the cap body can hold the outer peripheral surface of the pipe with the inner peripheral surface, the inner peripheral surface securely holds the pipe and protects it even if it receives a slight impact while the protective cap is attached. The cap will not easily fall off the pipe. However, when the cap body is composed of a small-diameter portion and a large-diameter portion, the distal end side can be clamped on the inner peripheral surface of the small-diameter portion with respect to the annular bulging portion of the pipe.
[0015]
In addition, if the cap body is provided with a plurality of protrusions in the axial direction that are in contact with the outer peripheral surface of the pipe and can hold the pipe on the inner peripheral surface, or a plurality of holding projections are provided, the cap body is connected to the entire inner peripheral surface of the small diameter portion As in the case of sandwiching the protective cap, it is possible to satisfactorily prevent the protective cap from being inadvertently removed from the pipe. Furthermore, the surface pressure acting on the outer peripheral surface of the pipe is partially increased as compared with the case where the pipe is sandwiched over the entire inner peripheral surface of the small diameter portion, but from the gap between the inner peripheral surface of the small diameter portion and the outer peripheral surface of the pipe. Since air enters and exits, the protective cap can be attached and detached more smoothly. Further, when the cap body is composed of a small diameter portion and a large diameter portion, the protrusion or the holding protrusion is provided on the inner peripheral surface of the small diameter portion.
[0016]
Further, in the case of a protective cap for piping provided with an annular bulging portion, the large diameter portion where the annular bulging portion is arranged has an inscribed circle diameter that is smaller than the outer diameter of the annular bulging portion of the piping. A plurality of locking protrusions may be provided on the inner peripheral surface. Then, at the time of attaching and detaching the pipe, the annular bulging portion can get over the locking projection due to the elasticity of the resin forming the cap body, but when the cap main body is mounted, the annular bulging portion abuts the locking projection. It can be used as a means for preventing omission. This means to prevent unintentional removal of the protective cap even if a slight removal force is applied when the protective cap is attached. It can be done.
[0017]
In addition, since the tip of the pipe surely hits the bottom wall and the position of the tip can be specified based on the thickness of the bottom wall, the cap body may be made opaque such as black as in the prior art. However, if the cap body is formed of a transparent or translucent resin, the position of the tip can be reliably determined from the outer surface of the cap body, and the working efficiency of bending can be further improved. In particular, in the case of a pipe provided with an annular bulge, the presence or absence of the annular bulge can be clearly confirmed with the cap body attached, and the unsorted product can be sorted efficiently. The occurrence of non-defective products can also be suppressed.
[0018]
Moreover, it is preferable to use polyethylene, polyamide, polypropylene, polyacetal or the like as the transparent or opaque resin material, and the material cost is low and easy molding is possible, and the cap body can be formed at low cost. Compared to conventional vinyl chloride protective caps that are highly adhesive and flexible, the cap body made of the above resin has moderate hardness and self-lubricating properties without excessive bending or expansion and contraction. Detachment work can be performed more smoothly. Vinyl chloride has a great impact on the environment, but polyethylene, polyamide, polypropylene, polyacetal, and the like can be safely used and disposed of, and can be easily recycled.
[0019]
【Example】
1 is a cross-sectional view of a protective cap according to a first embodiment of the present invention. In this embodiment, a pipe can be clamped on the inner peripheral surface of a small diameter portion. 3 is provided with three locking projections as a means for preventing removal at the diameter, and FIG. 2 is a plan view of the insertion port side of FIG. Further, in the second embodiment shown in FIG. 3, the pipe can be clamped by the protrusion provided on the inner peripheral surface of the small diameter portion, and six locking projections are provided on the large diameter portion. FIG. 4 is a plan view of the insertion port side in FIG. 3. In the third embodiment shown in FIG. 5, the piping can be held by holding protrusions provided on the inner peripheral surface of the small diameter portion. FIG. 6 shows a conceptual diagram in which the piping is held and fixed in a state where the protective cap is mounted and bending is performed.
[0020]
First, in each of the above-described embodiments, (1) is a pipe, which is formed of a metal or resin such as a relatively thin single-pipe steel pipe, double-pipe steel pipe, or aluminum pipe having a pipe diameter of 30 mm or less. 2) Project an annular bulge (3) on the outer peripheral surface at a fixed interval by spooling and connect the part including the annular bulge (3) from the tip (2) to a quick connector or the like. The insertion portion (4) serves as a joint to the means.
[0021]
A protective cap for protecting the pipe (1) from the tip (2) and the insertion part (4) including the annular bulge (3) and protecting it from impacts is easy to visually check the internal pipe (1). The cap body (5) is formed of possible translucent low density polyethylene, one end of the cap body (5) is a bottom wall (6) perpendicular to the axial direction of the pipe (1), and the other end is a pipe (1 ) Is formed in a cylindrical shape having a U-shaped cross section. Further, this cylindrical portion has a small-diameter portion (8) on the bottom wall (6) side, and can be arranged on the tip (2) side of the annular bulging portion (3) of the pipe (1). ) Side is the large diameter portion (10), and the annular bulging portion (3) of the pipe (1) can be arranged. In the above description, the cap body (5) is formed of low-density polyethylene which is a kind of polyethylene, but may be formed of polyamide, polypropylene, polyacetal or the like.
[0022]
Further, the formation length of the small diameter portion (8) indicated by a in FIG. 1 is shorter than the formation length b from the tip portion (2) of the pipe (1) to the annular bulge portion (3). 1. As shown in FIG. 3, when the pipe (1) is inserted into the cap body (5), it is formed with such a dimension that the tip (2) of the pipe (1) reliably hits the bottom wall (6). . Further, the bottom wall (6) is formed with a uniform thickness of about 1 mm so that the position of the tip (2) of the pipe (1) abutted against the bottom wall (6) can be specified accurately.
[0023]
In the first embodiment shown in FIGS. 1 and 2, the inner diameter of the small diameter portion (8) is formed to be substantially the same as the outer diameter of the raw pipe of the pipe (1), and the inner circumference of the small diameter portion (8) is formed. The outer peripheral surface of the pipe (1) can be clamped by the surface, so that the cap body (5) can be attached to the pipe (1) and the pipe (1) is prevented from being unintentionally detached.
[0024]
The large-diameter portion (10) has an inner diameter slightly larger than the outer diameter of the annular bulge portion (3), and the annular bulge portion is formed on the insertion port (7) side of the inner peripheral surface. Three locking projections (11) capable of abutting (3) are provided in a circumferential shape. These three locking projections (11) project so that the inscribed circle diameter is slightly smaller than the outer diameter of the annular bulging portion (3), and the annular bulging portion (3) is formed. By coming into contact with the locking projection (11), the pipe (1) is prevented from coming off. Further, by providing the locking projection (11) on the insertion port (7) side, the annular bulging portion (3) with the tip (2) of the pipe (1) abutting against the bottom wall (6) is provided. The protective cap of the present invention can be used for the pipe (1) formed so as to be in contact with the locking protrusion (11). As shown in FIG. 1, the annular bulge ( 3) The formation length up to 3) is comparatively short, and the dimensions are such that the annular bulging portion (3) does not contact the locking projection (11) with the tip (2) abutted against the bottom wall (6). It can also be used for the formed pipe (1), and it can be made a product with excellent versatility.
[0025]
Even if a slight pulling force acts on the cap (5) when it is mounted on the pipe (1) by the above-mentioned removal preventing means (12), The back of the annular bulge (3) is in contact with the locking projection (11) to prevent it from coming off, but when the pipe (1) is attached to or detached from the cap body (5), polyethylene, polyamide, polypropylene, polyacetal The annular bulging portion (3) can get over the locking projection (11) by the elasticity of the resin material such as, and smooth attachment / detachment work is possible.
[0026]
In contrast to the first embodiment, in the second embodiment shown in FIGS. 3 and 4, the inner diameter of the small diameter portion (8) is made larger than the outer diameter of the pipe (1), Four ridges (13) that are in contact with the outer peripheral surface of the pipe (1) and can clamp the pipe (1) are provided on the peripheral surface inwardly in the axial direction. By making it possible to hold the outer peripheral surface of the pipe (1) with these four protrusions (13), the effect of holding stability and prevention of pulling out can be obtained, and the inside of the small diameter part (8) of the first embodiment can be obtained. Although the surface pressure is partially higher than when the pipe (1) is clamped across the entire peripheral surface, air enters and exits from the gap between the inner peripheral surface of the small diameter portion (8) and the outer peripheral surface of the pipe (1). Therefore, the attaching / detaching operation of the protective cap can be performed more smoothly.
[0027]
Further, in the second embodiment, the disconnection preventing means is provided so that the plurality of types of pipes (1) having different formation lengths from the distal end portion (2) to the annular bulge portion (3) can be prevented from being disconnected. As (12), as shown in FIGS. 3 and 4, six locking projections (11) are alternately projected at regular intervals in the axial direction on the inner peripheral surface of the large-diameter portion (10). With such an arrangement of the locking projections (11), the rear surface of the annular bulge portion (3) formed at an arbitrary position of the pipe (1) can be connected to the six engagement members as shown in FIG. Contacting any one of the stop projections (11) makes it possible to satisfactorily prevent unintentional disconnection of the pipe (1) from the cap body (5).
[0028]
In the second embodiment, the protrusion (13) is provided on the inner peripheral surface of the small diameter portion (8). However, as in the third embodiment shown in FIG. 5, the inner peripheral surface of the small diameter portion (8). A plurality of holding projections (18) are provided at regular intervals in the axial direction, and a plurality of holding projections (18) arranged in the axial direction are arranged at regular intervals in the circumferential direction. (18) makes it possible to hold and fix the outer peripheral surface of the pipe (1). Further, as long as the pipe (1) can be held, the holding protrusions (18) may not be provided at regular intervals in the axial direction and the circumferential direction as in the third embodiment, but may be provided randomly. As shown, the holding protrusion (18) may have a quadrangular shape, a circular shape, an elliptical shape, or any other suitable shape.
[0029]
In the pipe (1) equipped with the resin protective cap of the present invention as described above, the insertion part (4) to the quick connector or the like is protected, and the pipe (1) is transported and stored in the bending process. Can prevent damage to the plating film or the resin coating film disposed on the outer periphery of the insertion portion (4) even when subjected to a slight impact during installation on a vendor. Furthermore, since the cap body (5) has a U-shaped symmetrical shape, more orderly stacking and alignment inspection is possible, bulkiness is prevented and storage and transportation are improved, and the piping (1) This prevents the cap body (5) from being inadvertently dropped off. Further, since the internal pipe (1) can be visually observed through the translucent cap body (5), the unprocessed pipe (1) of the annular bulge (3) can be found at a glance, and the pipe By removing (1) from the bending line, wasteful bending can be omitted and work efficiency can be improved, and occurrence of defective products can be prevented. Further, by forming the cap body (5) with low density polyethylene, the cap body (5) has an appropriate hardness and self-lubricating property without excessive bending or expansion / contraction, so the cap body (5) to the pipe (1) ) Can be attached and detached easily and quickly.
[0030]
When bending the pipe (1) by the vendor, as shown in FIG. 6, the cap body (5) is attached by the chuck (14) while the cap body (5) is mounted on the pipe (1). The pipe (1) is fixed while holding the outer periphery of the cap, and the bottom wall (6) of the cap body (5) is abutted against the inner peripheral surface of the chuck (14) as a stopper. Here, conventionally, a protective cap made of vinyl chloride and having an inclined bottom wall was attached, making it difficult to determine the bending plane position and the bending processing position based on the position of the tip of the pipe. It was inefficient because it was necessary to remove and reattach the protective cap from the pipe before and after bending.
[0031]
However, in the cap main body (5) of the present invention, the bottom wall (6) that abuts the tip (2) of the pipe (1) is a flat surface that is perpendicular to the axial direction and has a thickness of, for example, 1 mm. Thus, the position of the tip (2) of the pipe (1) can be accurately calculated and specified with the cap body (5) attached. Therefore, it is possible to specify the clamping position at the chuck (14) and the clamp (15) and the bending position with high accuracy with the tip (2) as a reference, and the chuck (14) and the clamp (15). The pipe (1) can be stably fixed. And by interlocking with the mold roll (16) and the receiving roll (17), the pipe (1) can be bent at an accurate position, and the quality of the product can be improved. Further, it is possible to save the labor of detaching the cap body (5), to perform an efficient bending work, and to greatly improve productivity.
[0032]
In addition, since the pipe (1) is held via the resin cap body (5), the plated coating on the insertion portion (4) by the chuck (14), and particularly the resin coating film disposed on the upper layer is damaged. It is possible to satisfactorily prevent the occurrence of the problem, and the highly reliable airtightness between the sealing member and the like in the quick connector and the insertion portion (4) can be obtained, and the pipe (1) free from fuel leakage or the like can be used satisfactorily.
[0033]
In each of the above embodiments, the protective cap is used for the pipe (1) provided with the annular bulge portion (3), but the smooth pipe (1) without the annular bulge portion (3) is inserted. Of course, it can also be used for protecting the part (4). In this case, since there is no annular bulging portion (3), the cap body (5) is formed without providing the large diameter portion (10), and there is no step from the bottom wall (6) to the insertion port (7). Also, it may have a smooth inner peripheral surface.
[0034]
【The invention's effect】
The present invention is configured as described above. In automobiles and machines, etc., it is used as an insertion portion for a quick connector of a steel pipe, an aluminum pipe, a copper pipe, a stainless steel pipe, and other pipes for supplying fluid such as fuel and oil. The protective cap to be mounted is formed in a U-shaped cross section having a bottom wall having a uniform thickness, and the tip of the pipe is abutted against the bottom wall. Therefore, it is possible to stably hold the pipe with the vendor's chuck with the protective cap attached, and it is possible to accurately identify the position of the tip of the pipe and the position of the bending plane by abutting the bottom wall against the stopper. The bending position can be positioned with high accuracy using the tip as a reference. In addition, it is possible to obtain a high-quality product with an accurate bending position for each pipe.
[0035]
In addition, it is possible not only to prevent damage to the plating film on the insertion part of the pipe due to the impact during transportation or storage of the pipe, but also the resin coating film disposed on the upper layer by installing a protective cap. By holding the pipe with the chuck through the cap, it is possible to satisfactorily prevent damage to the plating film or the resin coating film of the insertion portion due to the chuck. In addition, since the protective cap has a U-shaped cross-sectional shape, it can be stacked and ordered more orderly, preventing bulk, improving storage and transportability, and inadvertently providing a protective cap. Dropout can be prevented well. Furthermore, not only when bending with a chuck, but also when transporting and storing pipes before and after bending, the protective cap can be attached. For this reason, if a protective cap is attached to this insertion part after processing the insertion part, which is a pipe joint, it is not necessary to remove the protective cap until the pipe is connected with a quick connector, etc. Thus, it is possible to protect the insertion portion of the pipe and prevent damage to the plating film and particularly the resin coating film on the upper layer. Therefore, highly reliable airtightness with the connection destination of the pipe can be obtained, and fuel can be smoothly distributed in automobiles and other devices without causing problems such as fuel leakage.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a protective cap according to a first embodiment of the present invention.
FIG. 2 is a plan view of the insertion port side in FIG.
FIG. 3 is a sectional view of a protective cap according to a second embodiment.
4 is a plan view of the insertion port side in FIG. 3;
FIG. 5 is a cross-sectional view of a protective cap according to a third embodiment.
FIG. 6 is a conceptual diagram in which a pipe fitted with a protective cap is bent by holding it with a chuck.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Piping 2 Tip part 3 Annular bulging part 5 Cap main body 6 Bottom wall 7 Insertion port 8 Small diameter part 10 Large diameter part 11 Locking protrusion 12 Detachment prevention means 13 Projection 14 Chuck 18 Holding protrusion

Claims (2)

The bottom wall of the protective cap made of resin material with the other end as the pipe insertion port is formed with a bottom wall with a uniform wall thickness perpendicular to the axial direction of the pipe, and the pipe inserted into the bottom wall from the insertion port The tip of this pipe can be identified from the outside by abutting the tip of the pipe, and the pipe is fixed via the cap body by holding the outer periphery of the cap body attached to the pipe with the chuck of the vendor. A method of bending a pipe equipped with a resin protective cap for piping, wherein the bending of the pipe is performed by the vendor based on the specified tip of the pipe. The cap body is formed of a small-diameter portion on the bottom wall side and a large-diameter portion on the insertion port side, a pipe provided with an annular bulge is inserted from the insertion port, and the tip of the pipe is pushed against the bottom wall. 2. The method of bending a pipe fitted with a resin protective cap for piping according to claim 1, wherein the annular bulging portion of the pipe is arranged at a large diameter portion in a state of contact.

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