JPH09203456A - Flanged pipe and method of forming flanged pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a flanged pipe such as a feed pipe for defining an oil passage in an automobile transmission, in which a flange part and a pipe part are formed integrally with each other, and the diameter of the flange part is enlarged to a value about two times as large as the diameter of the pipe by bulging the flange part. SOLUTION: A pipe 1 is held at its one end in a holding hole 10a in a holder 10, and is inserted therein at its the other end opening with an insertion part 12a of a punch 12 which is then pressed so that a curl forming part in the root peripheral part of the insertion part 12 enlarges and arcuately curves the opening edge of the pipe 1. Further, during this process, the front end part is forced into a fold-back guide groove (m) in the holder 10 so as to be guided, and finally, a hemming part (h) of the front end part is processed simultaneously with the formation of a flange part 1b. Further, the flange part has a diameter which is about two times as large as that of the pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a pipe having a flange portion on one end side of the pipe portion such as a feed pipe forming an oil passage of oil in a transmission of an automobile.

[0002]

2. Description of the Related Art Conventionally, for example, in a transmission of an automobile, a feed pipe forming an oil passage of oil is attached to a cover. A flange portion is formed at the end of the feed pipe on the mounting side, and the flange portion has a circular portion with a generally small amount of protrusion and a pair of protrusions extending outward from the diametrical ends of the circular portion. The fitting portion of the cover is provided with a fitting groove having a circular concave portion and a locking concave portion in accordance with the shape of the flange portion.

The engaging portion of the flange portion is fitted into the engaging recess portion of the cover so as to prevent relative rotation between the feed pipe and the cover. Normally, the engagement of the flange portion is such. Since it is necessary to increase the amount of overhang of the stopper and to provide the overhanging end with strength to prevent the stopper from rotating, the pipe and the flange are separately constructed and joined.

That is, in the conventional general manufacturing method, it is said that the flange forming with a diameter of up to about 1.4D with respect to the pipe diameter D is the limit when the tip opening of the pipe is spread and flange processing is performed. For example, in the case of a feed pipe that requires a flange overhang of about 2D, integral molding is impossible. Moreover, the projecting end of the integrally molded flange portion is weak in strength and easily broken, and it is not suitable for a portion to which a load is constantly applied, such as a detent portion. For this reason, the conventional feed pipe has been used, for example, as described above, in which a flange made of a steel plate is brazed with copper on a steel pipe.

[0005]

However, when the feed pipe is brazed, the following various problems occur. That is, the first is that an O-ring for preventing oil leakage is usually attached to the outer circumference of the pipe around the brazing location, but when the brazing material flows to the pipe side, the sealing property of the O-ring is impaired. Be done. Further, in No. 2, the joint angle between the pipe and the flange is not kept at a right angle, and oil easily leaks. In the case of No. 3, the steel pipe is likely to be distorted due to the heat effect of brazing. Further, No. 4 is that pinholes are generated when the joining by the brazing material is incomplete and oil leakage occurs.

Therefore, there has been a demand for a flanged pipe which can prevent various problems caused by such brazing.

[0007]

In order to solve the above-mentioned problems, the present invention provides a flanged pipe according to claim 1, wherein the flange portion is integrally formed on one end side of the pipe portion, and the outer diameter of the flange portion is A flanged pipe having a diameter of about twice the outer diameter of the pipe portion and a hemming portion formed at the flange end was formed. By thus making the amount of protrusion of the flange portion about twice the outer diameter of the pipe portion, it can be applied to, for example, the flange portion of a feed pipe. At this time, the hemming portion at the end of the flange can improve the strength of the end.

According to a second aspect of the present invention, in the molding method, one end side of the pipe is inserted into the holding hole of the holder, the other end side opening is exposed and held outside, and the punch of the punch is inserted into the other end side opening. Insert the insertion part and push it toward the holder side, and at the curl part around the root part of the insertion part of the punch, expand the opening edge of the pipe outward while curving it in an arc shape and expand it. The tip of the peripheral edge is inserted into the folding guide groove on the tip surface of the holder so as to guide in the folding direction. Then, at the final stage of pushing the punch, the front portion of the punch and the tip end portion of the holder are sandwiched and pressed to form a flange portion, and the tip peripheral edge portion that has entered the folding guide groove is hemmed. .

In this way, after the opening edge of the pipe is pushed outward while curving in an arc shape outwardly, the pushed edge of the peripheral edge is inserted into the folding guide groove on the tip surface of the holder, and is further extended. By bending in the folding direction and finally performing the hemming of the end portion simultaneously with the flange forming, the flange overhanging amount can be increased within a range not exceeding the plate elongation limit. As a result of experiments, it was confirmed that when the molding was performed by such a technique, the flange end portion was not broken even when the pipe was stretch-molded to about twice the pipe diameter.
It is considered that this is because the end portion is restrained by the folding guide groove and receives the compressive stress before the tensile stress acts on the end portion to cause the rupture and the rupture does not occur.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is an application example diagram when the present flanged pipe is used as a feed pipe of an automobile transmission, FIG. 2 is a front view of the feed pipe seen from a flange portion, and FIG. 3 is a line AA of FIG. Sectional drawing and FIG. 4 are process drawings showing a method for forming the feed pipe. As shown in FIG. 1, the present flanged pipe is applied to feed pipes 1 and 2 having a double pipe structure that forms an oil passage in a transmission of an automobile, and these feed pipes 1 and 2 are both pipe parts 1a and 2a. The flange portion 1b, 2b formed by the same forming method is provided on one end side.

The flange portions 1b and 2b are formed integrally with the pipe portions 1a and 2a, and are viewed from the front of the flange portion 1b (hereinafter, the feed pipe 1 will be described as a typical example) of FIG. As shown in the drawing, both ends are configured as locking portions s that extend outwardly along one direction and the remaining portions are configured as circular portions e that extend relatively short.

As shown in FIG. 3, the tip of the engaging portion s of the flange portion 1b is folded back inward to form a hemming portion h, and these engaging portions s and s are formed. The flange diameter in the direction is about twice the pipe diameter D.

On the other hand, the cover 3 shown in FIG. 1 is formed with a fitting groove 3a into which the flange portion 1b of the inner feed pipe 1 can be fitted, and the shape of the fitting groove 3a is a flange. It is formed according to the shape of the portion 1b.
That is, the fitting groove 3a includes a circular recess having the same shape as the circular portion e of the flange portion 1b and a locking recess having the same shape as the locking portions s and s, and the locking portion s of the flange portion 1b. , S are fitted in the locking recesses of the fitting groove 3a so as to exert a rotation preventing function.

After the front surface side of the flange portion 1b of the feed pipe 1 is pressed and held by the positioning member 4, another positioning member 5 is provided on the outer side thereof, and on the back side of the positioning member 5, the outer feed pipe 2 is provided. Flange part 2b
A fitting groove 5a having the same shape as that of is provided. Then, the flange portion 2b is fitted in the fitting groove 5a, the outer feed pipe 2 is held while being prevented from rotating in the same manner as the inner feed pipe 1, and the feed guide member 6 is further provided outside thereof. It is fixed to prevent it from coming off. Then, the two feed pipes 1 and 2 form an oil passage that flows in the direction of the arrow in the figure. Incidentally, the pipe portions 1a, 2a of the feed pipes 1, 2
O-rings 7 and 8 are attached to the outer periphery of the above and near the flanges 1b and 2b to seal oil leakage.

Next, the feed pipes 1, 2 as described above
The molding method will be described with reference to FIG. Incidentally, also in this case, the feed pipe 1 will be described as a typical example. First,
As shown in (A), the steel pipe 1 is inserted into the holding hole 10a of the holder 10 and the end portion on the insertion side is brought into contact with the push-out pin 11 provided inside the holding hole 10a. Is exposed outside the holding hole 10a.

Then, the insertion portion 12a of the punch 12 is inserted into the opening of the pipe 1 exposed to the outside and pressed toward the holder 10 in parallel with the axis of the pipe 1, but the insertion portion 12a of the punch 12 is attached. A curl forming portion 12c, which is continuous with the front surface 12f, is formed around the root portion with a predetermined radius. Therefore, when the punch 12 is moved forward and pressed, the opening edge portion abuts on the curl forming portion 12c, and thereafter is curled and expanded outward by the curl forming portion 12c.

On the other hand, on the front surface 10f of the holder 10, an annular folding guide groove m is formed around the holding hole 10a, and the peripheral wall of the folding guide groove m near the outer periphery has a comparatively gentle curve. It is curved at. When the opening edge of the pipe is expanded and curved in the above-described manner, the tip portion is folded back along the guide groove m.
It is designed to enter from the outer peripheral wall of the, and due to the gentle curve of the outer peripheral wall of the folding guide groove m,
As shown in (B), the tip portion is finally curved to about 270 degrees. At this point, control is performed so that the push-out diameter of the opening edge portion that is pushed outward is within 1.4 times the pipe diameter D.

Next, as shown in (C), the punch 12 is further advanced and pressurized, and the spread portion is crushed by the front surface 12f of the punch 12 and the front surface 10f of the holder 10 and is perpendicular to the pipe portion 1a. At the same time that the protruding flange portion 1b is formed, the portion that has entered the folding guide groove m is hemmed to form a hemming portion h at the tip.
At this time, the diameter of the flange portion 1b is about twice as large as the diameter D of the pipe, and moreover, by simultaneously hemming the flange end portion, breakage or the like does not occur at the end portion.

When the flange portion 1b is formed in this way, the feed pipe 1 is extruded from the holding hole 10a of the holder 10 by the extruding pin 11, and then the flange portion 1b is formed by the stripper mold 13 as shown in (D). Remove unnecessary parts of. That is, after inserting the feed pipe 1 into the holding hole 14a of the die 14 and supporting one end side with the pushing pin 15, the punch holder 16 is abutted against the flange portion 1b, and the outer punch 17 is advanced to the chain line position to remove unnecessary portions. It cuts and shape | molds the flange part 1b of the shape of FIG. That is, the engaging parts s, s are left to be cut, and the cut part is made into a circular part e.

By the above-mentioned molding method, for example, when the pipe portion and the flange portion are separately molded and brazed, the brazing material flows to the pipe side and the O-rings 7 and 8 are sealed. There are various problems such as deterioration, the perpendicularity of the pipe and flange is not guaranteed, the pipe is distorted due to the heat effect of brazing, and the pinning occurs due to incomplete brazing. It can be prevented.

It is needless to say that the flanged pipe of the present invention is not limited to the feed pipe as described above and can be widely applied, and in particular, the flange portion is extended and the pipe portion Airtightness at the joint of the flange,
This is effective when liquid tightness is required. Regarding the molding method, the step of (D) of FIG. 4 relates to the method of molding the feed pipe which is the embodiment, and the molding method of the present invention may relate to the steps up to (C). Needless to say.

[0022]

As described above, according to the present invention, the opening edge of the pipe is pushed outward while curving in an arc shape, and the tip of the pushed peripheral edge is guided in the folding direction by the folding guide groove. At the final stage, the part that was expanded was crushed to form the flange part, and the tip peripheral edge part was subjected to hemming processing. ,
It is possible to mold with high precision without causing defects such as breakage at the end of the flange portion. By integrally molding in this way, it becomes possible to prevent various problems such as joining separate members. Further, since the hemming process can be performed on the flange end portion at the same time when the flange portion is formed, it is convenient for maintaining the strength.

[Brief description of drawings]

FIG. 1 is an application example diagram when the flanged pipe of the present invention is used as a feed pipe of an automobile transmission.

FIG. 2 is a front view of the feed pipe seen from a flange portion.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a process diagram showing a method for forming the feed pipe.

[Explanation of symbols]

1, 2 ... Feed pipe, 1a, 2a ... Pipe part, 1
b, 2b ... Flange section, 10 ... Holder, 10a ... Holding hole, 12 ... Punch, 12a ... Insert section, 12c ... Curl forming section, m ... Folding groove, h ... Hemming section.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area F16L 9/02 F16L 9/02

Claims (3)

[Claims] 1. A pipe with a flange in which a flange portion is integrally formed on one end side of the pipe portion, wherein the outer diameter of the flange portion is about twice the outer diameter of the pipe portion, and the hemming portion is provided at the flange end portion. A flanged pipe characterized by being formed. 2. A method for forming a flanged pipe, wherein a flange portion is integrally formed on one end side of the pipe portion, wherein one end side of the pipe is inserted into a holding hole of a holder and the other end side opening is exposed to the outside. And the step of holding it, and insert the insertion part of the punch into the opening on the other end side and push it toward the holder side, and turn the opening edge of the pipe outward with the curl part around the root of the insertion part of the punch. Front end of the punch at the final stage of pushing the punch, and the step of pushing it open while curving it in an arc shape and pushing it open, and the step of pushing this pushed peripheral edge into the turning guide groove on the tip surface of the holder and guiding it in the turning direction. And the holder tip surface is sandwiched and pressed to form a flange portion, and the tip peripheral edge portion that has entered the folding guide groove is hemmed. Forming method of flanged pipe. 3. The method for forming a flanged pipe according to claim 2, wherein the outer diameter of the flange portion is about twice the outer diameter of the pipe portion.