JP2675535B2 - Shaft seal type nipple with flange - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft seal type nipple with a flange, and more specifically, a flange made of an Al alloy used as a fitting for connecting a piping hose such as a refrigerant circuit or a hydraulic circuit to a counterpart device. A shaft seal type nipple and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, as a method of connecting a rubber hose or a flexible hose used for piping of a refrigerant circuit or a hydraulic circuit to a counterpart device such as an air conditioner or a hydraulic device, the hose end is thin-walled. A method in which a pipe-shaped metal nipple is crimped to be integrally connected and connected to a mating member via the nipple is generally adopted. Although there are various forms of these nipples from the past, they are made of an aluminum alloy material that is lightweight and excellent in workability, and a flange as a nipple is fixed to a mating member through the flange. Nipple with flange for fastening is widely adopted. Further, in the nipple with a flange, an O-ring is fitted to the outer periphery of the tip end portion that is inserted into the connection opening of the mating member, and a shaft seal type that seals with the mating member by the O-ring is used. O fitted into the counterbore part of the connecting opening end of the mating member
There is a seat seal type that presses the ring to seal the two, but in recent years, the shaft seal type is often used because it is possible to more reliably maintain the airtightness with the counterpart device. It is like this.

Typical examples of these flanged nipples are shown in FIGS. 4 (a) and (b). The flanged nipple shown in (a) of FIG. 4 is of a shaft seal type, and has a fitting protrusion (32a) formed on the front surface of the flange (34), and the fitting protrusion (32a) is slightly While thickening and providing an O-ring groove (35) on the outer periphery, insert the tip of the pipe (31) into the rear surface side of the flange (32) and perform TIG or MIG welding in an inert gas atmosphere or brazing. They are integrally joined at the joint portion (34). Then, the fitting protrusion (32a) of the flange (32) is inserted into the connection opening end (30a) of the mating member (30) and fastened with the bolt (36), and fitted on the outer periphery of the fitting protrusion (32a). Wearing O-ring
(35) seals the mating member (30). On the other hand, a pipe hose (38) is caulked to the rear end portion (31b) of the pipe (31) by a socket (37). The flanged nipple shown in (b) is of a seat seal type, and axially presses the tip portion (41a) of the pipe (41) inserted into the insertion hole (44) of the flange (43), The counterbore (44) provided at the front end of the insertion hole (44)
a) The pipe (41) is integrated with the flange (43) by pressing it inside and causing the tube wall of its root to buckle and bulge outward to form an annular bulge (42). . And
Tip (41a) of the pipe (41) protruding from the flange (43)
Is inserted into the connection opening end (40a) of the mating member (40) and fastened with the bolts (36), and the counterbore (40) of the connection opening end (40a) is
The O-ring (45) fitted in (b) is pressed by the front surface of the flange (43) to seal the mating member (40). on the other hand,
A pipe hose (48) is caulked to the rear end portion (41b) of the pipe (41) by a socket (47). In addition, in this type of flanged nipple, a plurality of axial engagement grooves are provided in the insertion hole of the flange in order to secure a specified rotary tokle, and the punch is inserted from the tip at the time of or after the formation of the bulge portion. By press-fitting to expand the diameter of the pipe inserted in the insertion hole of the flange and bite the wall thickness of the pipe into the engagement groove on the inner surface of the insertion hole, so that the pipe and the flange are integrated under high rotational torque. The method of making it
Further, for example, in Japanese Examined Patent Publication No. 2-34700, a radial engagement groove is formed in the inner bottom surface of the counterbore portion of the flange, and the bulge portion is pressed by an axial pressing force when forming the bulge portion. By forming engagement teeth that engage with the engagement grooves of the flange on the back surface, the pipe and the flange are integrated under high rotational torque.

[0004]

However, in the former nipple with a flange, that is, with a shaft seal type nipple with a flange, the above-mentioned conventional nipple can secure a seal between the mating member, but does not weld or weld between the pipe and the flange. Since the airtightness is maintained at the joint portion (34) by brazing, there is an inherent problem that it is difficult to sufficiently secure the reliability of the airtightness. Further, when a large torque is applied around the axes of the hoses after they are attached, the pipe and the flange may be displaced from each other, and the airtightness may be greatly impaired. Further, since the flange fitting protrusion is formed, the manufacturing process thereof is complicated, and if the flange and the fitting protrusion are assembled in order to avoid it, welding or brazing is required to join the two. , The same problem as above is derived.
On the other hand, in the latter conventional flanged nipple, that is, the flanged seat seal type nipple, since the tip end of the pipe is directly inserted into the mating member, there is no problem of airtightness in the nipple itself. Although the rotational torque can be increased by taking such an engagement means, it is disadvantageous in terms of ensuring airtightness with the mating member as compared with the shaft seal type.

Here, under the latter structure of the above-mentioned conventional,
It is easily conceivable to provide an O-ring groove on the outer circumference of the pipe tip to form a shaft seal type. In this case, in the case of a nipple having a small diameter, the depth of the O-ring groove constitutes the nipple. The thickness is almost the same as the wall thickness of, and it becomes impossible to cut from the viewpoint of structural strength. Further, when the O-ring groove is intentionally bored, it is necessary to make the pipe to be used thick, which makes molding of the bulge portion very difficult, which is not practically applicable. Therefore, as shown in (a) of FIG. 3, the present inventors grasp and constrain the pipe (21) as the object to be molded by the clamp (C) near the tip and press the pressing shaft from the tip side. Outer ring that is driven and rotated while pressing with (S) to apply compressive force in the axial direction (R)
A plurality of rolling dies (Dr) that are freely held on the axis of rotation are synchronously revolved in a plane perpendicular to the axis of the pipe (21) and pressed against the outer circumference of the pipe (21) to use cutting processing. Without forming the groove (23) on the outer periphery of the pipe (21) (Japanese Patent Application No. 4-195425) and the tip of the Al alloy pipe (21) having mechanical properties within an appropriate range After expanding the tube to form the expanded diameter tip (21a) of the specified outer diameter,
An annular bulge portion (22) is formed on the outer periphery following 1a), and then, as shown in the same figure (a), the bulge portion (2) of the pipe (21) is formed.
2) A nipple formed by forming an O-ring groove (23) using a rolling die (Dr) on the outer circumference of the front expanded tip (21a) and its manufacturing method (Japanese Patent Application No. 4-30744) are claimed in the present application. I made a proposal in advance.
According to these prior application techniques, a continuous fiber structure can be obtained without significantly reducing the wall thickness of the bottom of the O-ring groove, the product strength can be increased, and the yield can be increased because cutting is not performed. . Then, according to these prior arts, as shown in (b) of FIG. 3, a pipe (21) formed with an O-ring groove (23) and a bulge portion (22) is replaced with the latter one of the conventional ones. Integrating with the same configuration Frangi (25),
It has become possible to obtain a shaft seal type nipple with a flange which does not have a problem of airtightness in the nipple itself and has a reliable seal with a mating member.

[0006] However, a more detailed study was made on obtaining a shaft seal type nipple with a flange by integrating a flange and a pipe having an O-ring groove and a bulge portion formed by rolling forming at the tip, and It was found that such a problem was derived, and it was difficult to integrate the pipe and the flange under high rotating torque. That is, by pressing the tip end portion of the pipe inserted into the insertion hole of the flange into the counterbore portion of the front surface of the flange to form a bulge portion, the diameter of the pipe is further expanded by press-fitting a punch to increase the inner diameter of the insertion hole. When the pipe and the flange are firmly integrated by engaging and then the O-ring groove is formed at the tip of the pipe with the rolling die, the outer ring of the rolling die and the flange interfere with each other. Therefore, it is practically difficult to apply. Also, after forming an O-ring groove on the outer circumference of the pipe tip by rolling, press the tip of the pipe into the counterbore on the front surface of the flange to form a bulge, thereby integrating the pipe and the flange. In such a case, the O-ring groove that has already been formed is deformed by the axial pressing at that time, and the O-ring groove is likely to be out of the standard size. In addition, a bulge portion is formed on the pipe by another pressing die, and then an O-ring groove is formed on the outer periphery of the tip end portion of the pipe by a rolling die, and the formed pipe is inserted into the flange from the rear end side. In order to integrate the pipe and the flange by pressing the punch from the tip to expand the diameter of the pipe and engaging the wall of the pipe with the inner surface of the insertion hole, the pipe is molded at the tip of the pipe. Since the inner diameter of the O-ring groove portion is equal to or slightly smaller than the original inner diameter of the pipe, the diameter of the pipe located in the insertion hole portion at the back cannot be increased. Therefore, the pipe formed by rolling the O-ring groove and the bulge portion at the tip is inserted into the flange from the rear end side, and as shown in (b) of FIG. 3, the rear surface of the flange (25) It is necessary to weld or braze the side to join and integrate the flange (25) and the pipe (21). But,
At the joint (24) by welding or brazing, the hardness of the pipe changes due to the heat at the time of joining, and when bending the rear end of the pipe, there is no constriction or breakage around the joint (24). Damage may occur. Further, many steps such as heat treatment after joining, cleaning treatment for flux removal, and corrosion-resistant treatment such as allodin treatment are required, which causes a problem that the product cost increases.

The present invention has been made to solve the above-mentioned problems of the prior art. A pipe and a flange provided with an O-ring groove by a rolling process at the tip end thereof have a high rotational torque without welding or brazing. An object of the present invention is to provide a shaft-sealed nipple with a flange and a method for manufacturing the same, which can be integrally fixed under pressure and have excellent structural strength and sealing function.

[0008]

In order to achieve the above object, the present invention has the following arrangement. That is, the shaft seal type nipple with a flange according to the present invention is made of an Al alloy material, has an O-ring groove on the outer periphery of the tip portion to be inserted into the mating member, and has an annular bulge portion at the root portion of the tip portion. A pipe and an Al alloy material are provided, and a front surface portion has a seat hole into which the bulge portion of the pipe is fitted, and a main body portion of the pipe that is provided concentrically with the seat hole and follows the bulge portion is inserted. A shaft seal type nipple with a flange having an insertion hole that is provided with a flange for attaching the pipe to a mating member, wherein an O-ring groove at the tip of the pipe is formed by rolling. ,
Moreover, a counterbore portion is formed at the rear opening end of the insertion hole of the flange, the diameter of which is increased in the oblique radial direction, and the outer peripheral surface of the pipe located in the counterbore portion is closely attached to the inner peripheral surface of the counterbore portion. It is characterized in that an engaging bulging portion that engages is formed.

Further, according to the method for manufacturing a shaft seal type nipple with a flange of the present invention, an outer diameter regulating die and a pipe expanding punch are used to expand a predetermined outer diameter on one end side of an Al alloy pipe cut into a predetermined length. After forming the diametrical tip, form an annular bulge part on the outer circumference of the pipe following the diametrical expansion tip by using a bulge die, and then use a rolling die on the outer circumference of the diametrical expansion tip to form an O-ring groove. A pipe forming step for forming a pipe, a seat hole which is manufactured in advance, is provided with an insertion hole for inserting the pipe, and the bulge portion is inserted into the front end portion of the insertion hole, and a seat having a rear end portion which is radially enlarged in a radial direction. On the flanges made of Al alloy, which have concentric bores,
The formed pipe that has undergone the pipe forming step is inserted from the rear end side into the insertion hole of the flange, and the bulge portion is fitted into the counterbore portion to integrally combine the two, and then the front end portion of the formed pipe is inserted. While setting in a pressing die having a pressing surface that contacts the front surface of the bulge portion of the molded pipe,
The outer periphery of the portion of the pipe protruding from the rear surface of the flange at a predetermined small distance from the rear surface of the flange is clamped, and the pressing die is axially moved to move to the spot facing portion of the rear portion of the insertion hole of the flange. An engaging bulging portion is formed on the outer circumference of the positioned pipe to closely engage with the inner peripheral surface of the counterbore portion, and the press-connecting step of fixing the molded pipe to the flange is performed.

[0010]

With the shaft seal type nipple with flange of the present invention,
A pipe having an O-ring groove on the outer periphery of the tip portion and an annular bulge portion at the root of the tip portion is inserted from the rear end side into the insertion hole of the flange, and is concentric with the insertion hole on the front surface of the flange. After fitting the bulge portion into the seat hole provided in the two and integrally combining them, the portion of the pipe protruding from the rear surface of the flange at a predetermined small interval is slanted in the diagonal radial direction to the opening end of the insertion hole of the flange. By pressing toward the counterbore formed by expanding the diameter of the pipe, an engagement bulge portion is formed on the outer periphery of the pipe located at the counterbore portion, which is in close contact with the inner peripheral surface of the counterbore portion. That is, that is, by tightening the flange from the front and rear sides by the bulge portion of the pipe and the engagement bulging portion to engage with each other, the pipe and the flange can be operated under a high rotational torque regardless of welding or brazing. It can be fixed and integrated. Further, since the O-ring groove at the tip of the pipe is formed by the rolling process, a continuous fibrous structure can be obtained without significantly reducing the wall thickness of the bottom of the O-ring groove as in the case of cutting. The structural strength can be maintained high. Further, since the tip end of the integral pipe is inserted into the mating member and the O ring fitted in the O ring groove at the tip of the pipe seals between the mating member and the mating member, there is a problem of airtightness in the nipple itself. Instead, it can have a high sealing function.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. [FIG. 1] is a drawing showing an embodiment of a shaft seal type nipple with a flange of the present invention, in which (a) is a front view showing a notched main part, and (b) is a view for explaining the structure of the flange. FIG. 6C is a plan view for doing so, and FIG.

In FIG. 1 (a), (10) is a mating member, and this mating member (10) is an air conditioner, hydraulic equipment, etc. A fluid introduction hole (10a) for introducing oil etc. is bored, and an opening end of the fluid introduction hole (10a) has a connecting hole (10b) having an inner diameter larger than that of the fluid introduction hole (10a). ) Is formed.

(1) is a pipe, and this pipe (1)
Is made of Al alloy, and the tip (1a) is expanded to an outer diameter that fits into the connecting hole (10b) of the mating member (10), and the root of the expanded tip (1a) is An annular bulge portion (2) is formed in the portion, and an O-ring groove (3) is formed in the outer periphery of the intermediate portion. Also,
This pipe (1) is inserted into the insertion hole (6) of the flange (5), which will be described later, through the main body portion that follows the bulge portion (2), and the enlarged diameter end portion
(1a) is projected forward, and it is curved in an L-shape at the intermediate portion behind the flange (5), and its rear end (1b)
The pipe hose (9) is caulked to the socket via the socket (8).

Here, the flange (5) is, as shown in FIG. 2 (b), made of an aluminum alloy having a planar outer shape formed into a spectacle shape in which two large and small discs are connected, and the larger disc is formed. An insertion hole (6) for inserting the pipe (1) is provided at the center of the part, and a fastening bolt (12) is provided at the center of the other small disk part.
It is provided with a bolt hole (7) for passing through. Also, as shown in Fig. (C), the insertion hole (6) of the flange (5) is formed as a straight hole, and the pipe (1) is provided at the front opening end thereof.
The bulge (2) of the seat hole (6a) is inserted, and the rear opening end is formed with the counterbore part (6b) that expands in the oblique radial direction, respectively, concentrically with the insertion hole (6). ing.

On the other hand, the O of the expanded end (1a) of the pipe (1)
The ring groove (3) is formed by the rolling process described later. On the other hand, the outer circumference of the pipe (1) inserted into the flange (5), which is located in the spot facing (6b) of the flange (5), is subjected to a pressing process described later to form an inner circumference of the spot facing (6b). Engagement bulge (4) is formed for close contact with the surface.The engagement bulge (4) and front bulge (2) tighten the flange (5) from both front and rear sides. By combining them, the pipe (1)
And the flange (5) are fixed together to form an integral shaft seal type nipple with a flange.

The shaft seal type nipple with a flange is provided with an O-ring in the O-ring groove (3) as shown in FIG.
The pipe (1) fitted with the (11) is fitted with the expanded tip (1a) of the pipe (1).
Insert it into the connecting hole (10b) of (10) and
It is attached to the mating member (10) through the fastening bolts (12) set in the bolt holes (7) of (5), and its diameter expansion tip (1a)
The O-ring (11) fitted to the above keeps airtightness between the mating member (10).

In the shaft seal type nipple of the present embodiment having the above-mentioned structure, the tip portion of the integral pipe is inserted into the mating member, and the O-ring fitted to the tip portion seals between the mating member and the mating member. There is no problem of airtightness in itself, and a high sealing function is secured. Also, since the flange is tightened from both the front and rear sides by the bulge portion and the engagement bulge portion of the pipe to engage with each other, the moment about the axis applied to the pipe or the like from the outside can be sufficiently endured without using welding or brazing. It can be fixed and integrated under high rotational torque.
Furthermore, since the O-ring groove at the tip of the pipe is formed by rolling, a continuous fiber structure can be obtained without significantly reducing the wall thickness of the bottom of the O-ring groove as in the case of cutting. , Its structural strength can be maintained high.

Next, one example of the method for manufacturing the flanged pipe of this embodiment will be described with reference to FIG. 2 which is an explanatory view of the outline process.

First, as shown in FIG. 1 (a), an Al alloy pipe (1) is cut into a predetermined length and chamfered at both ends. As shown in Fig. 2 (b), the outer shape of the plane is formed into a spectacle shape by connecting two discs, and an insertion hole (6) and a bolt hole (7) are provided to make an Al alloy. Produce the flange (5). In addition, at the front and rear opening ends of the insertion hole (6) of the flange (5), a seat hole (6a) having the shape shown in (b) of FIG. 1 is formed.
And a spot facing (6b). In addition, this flange (5)
Insertion hole (6), seat hole (6a), counterbore (6b) and bolt hole
(7) can be formed not only by cutting but also by die forging or press punching.

Then, as shown in (c), the pipe (1)
Clamping the outer circumference of the part that is spaced from one end of the
While gripping and restraining with (C), one end side of it is an outside diameter regulation type (Do)
A pipe expanding punch (P) equipped with
An enlarged diameter tip portion (1a) having a predetermined outer diameter is formed on one end side of (1).
Then, as shown in Fig. (D), the enlarged diameter tip of the pipe (1)
The outer periphery immediately after (1a) is gripped and restrained by a bulge die (Db), while the expanded diameter tip (1a) is axially pressed by a pressing die (Dp), and the root of the expanded diameter tip (1a) is Part of the bulge die, which is pressed against the front of the bulge die (Db) while buckling and bulging the bulge die, which is not restrained from the outside, crushes the material of the pipe wall and causes it to flow in the radial direction. (D
b) A bulge portion (2) having an annular shape is formed at the base of the enlarged diameter tip portion (1a) of the pipe (1) so as to fill the molding concave portion on the front surface.
Then, as shown in Figure (e), the bulge section of the pipe (1).
The outer periphery immediately after (2) is gripped and constrained by a clamp die (C), and the tip end surface is pressed by a pressing shaft (S) to apply a compressive force in the axial direction, and the rolling die (Dr) is The pipe (21) is pressed against the outer periphery of the middle portion of the enlarged diameter tip portion (1a) and revolved, and the O-ring groove (3) is formed on the outer periphery of the enlarged diameter tip portion (1a).

Then, through the above molding steps, the bulge portion
(2) and O-ring groove (3) molded pipe (1),
Insert from the rear end side into the insertion hole (6) of the flange (5),
(f) Insert the bulge (2) into the flange as shown in the figure.
After fitting them into the spot facing (6a) of (5) and combining them together, as shown in (g), a predetermined small space (L) of the pipe (1) protruding from the rear surface of the flange (5) is shown. ) Is clamped and constrained by the clamp type (C), and then the front of the bulge (2) and flange (5) of this pipe (1) is fixed as shown in (g). Pipe (1) positioned in the spot facing (6b) of the flange (5) by axially pressing with a pressing die (Pd)
An engaging bulge (4) is formed on the outer periphery of the engaging bulge (4) that closely engages with the inner peripheral surface of the spot facing (6b), and the engaging bulge (4) and the front bulge (2) are formed. The pipe (1) and the flange (5) are fixedly integrated with each other by tightening and engaging the flange (5) from both front and rear sides. Here, the pressing die (Pd) is a pipe
Insert the enlarged diameter tip (1a) of (1), and
It has a fitting recess with a depth that prevents the tip surface of a) from coming into contact, and a pressing surface that presses the front surface of the bulge portion (2) and the flange (5) on the tip surface around the fitting recess. It is supposed to be.

As a result of the above-mentioned pipe forming step and pressing connection step, as shown in (i), the pipe (1) and the flange
It is a shaft seal type nipple with a flange (5) integrally fixed, and a plurality of locking grooves (13) are provided on the outer periphery of the rear end (1b) of the pipe (1). According to this, the middle part is bent and the pipe hose is caulked, but in this flanged shaft seal type nipple, the tip of the integral pipe was inserted into the mating member and fitted to the tip. Since the O-ring seals between the mating member and the mating member, there is no problem of airtightness in the nipple itself, and a high sealing function is secured. Further, since the O-ring groove at the tip portion is formed by the rolling process, a continuous fibrous structure can be obtained without greatly reducing the wall thickness of the bottom of the O-ring groove as in the case of the cutting process. High strength can be maintained. Further, by tightening the flanges from the front and rear sides by the bulge portion of the pipe and the engagement bulging portion to engage with each other, the pipe and the flange are fixedly integrated under high rotation torque without welding or brazing. As a result, the required man-hours can be kept low and the manufacturing cost can be reduced.

The above-described embodiment is only one example, and the present invention is not limited to this embodiment. For example, it is possible to further increase the rotational torque by providing unevenness of radiation on the inner surface of the spot facing portion at the front and rear opening ends of the insertion hole of the flange, and the flange may be formed by a plurality of fastening bolts or fastening means other than bolts. It may be configured to be connected to a mating member. Further, it goes without saying that the vipe does not necessarily have to be curved in an L shape.

[0024]

As described above, in the flanged pipe according to the present invention, the flange and the pipe provided with the O-ring groove by the rolling process at the tip end have high rotational torque without welding or brazing. In the first place, they can be fixedly integrated with each other, so that the structural strength and the sealing function can be enhanced, and the required man-hours can be suppressed to be low to reduce the manufacturing cost.

[Brief description of the drawings]

1A and 1B are drawings showing an embodiment of a shaft seal type nipple with a flange according to the present invention, in which FIG. 1A is a front view showing a notch of a main part, and FIG. FIG. 3C is a plan view for that, and FIG.

FIG. 2 is an explanatory diagram of a schematic process of an example of a method of manufacturing a shaft seal type nipple with a flange according to the present invention.

FIG. 3 is an explanatory view of a nipple of a prior application and an explanatory view of a shaft-sealed nipple with a flange by the nipple.

FIG. 4 is a drawing showing the configuration of a typical example of a conventional flanged nipple.

[Explanation of symbols]

(1) --Expanded tip of pipe (1a) --Expanded tip (2) --Bulge (3) --O-ring groove (4) --Engagement bulge (5)-
Flange (6)-Insertion hole (6a)-Seat hole (6b)-Counterbore
(7) --Bolt hole (8) --Socket (9) --Piping hose
(10)-Mating member (10a)-Fluid introduction hole (10b)-Connecting hole
(11)-O-ring (12)-Fastening bolt.

Claims (2)

(57) [Claims] 1. A pipe made of an Al alloy material, having an O-ring groove on the outer periphery of a tip end portion to be inserted into a mating member and having an annular bulge portion at the root of the tip end portion, and made of an Al alloy material, The front portion has a seat hole into which the bulge portion of the pipe is fitted, and an insertion hole that is provided concentrically with the seat hole and through which a main body portion of the pipe following the bulge portion is inserted. A flanged shaft seal type nipple comprising a flange for attaching to a mating member, wherein the O-ring groove at the tip of the pipe is formed by rolling, and the insertion hole of the flange is formed. An engaging swelling portion is formed at the rear opening end so as to expand the diameter in an oblique radial direction, and an outer peripheral surface of the pipe located at the spotting portion is in close contact with an inner peripheral surface of the counterbore portion. Is specially formed A shaft seal type nipple with a flange. 2. An expanded diameter tip having a specified outside diameter is formed on one end side of an Al alloy pipe cut to a specified length by using an outside diameter control die and an expansion punch, and then the expanded diameter tip is formed on the expanded diameter tip. A pipe forming step of forming an annular bulge portion by using a bulge die on the outer periphery of the subsequent pipe, and then forming an O-ring groove by using a rolling die on the outer periphery of the enlarged diameter tip portion, and the pipe manufactured in advance, A flange made of an Al alloy, which is provided with an insertion hole through which the bulge portion is fitted at the front end of the insertion hole, and a counterbore portion which is enlarged in the oblique radial direction at the rear end portion and are coaxially provided, respectively. The molded pipe that has undergone the pipe molding step is inserted from the rear end side into the insertion hole of the flange, and the bulge portion is fitted into the counterbore portion to integrally combine the two, and then the front end portion of the molded pipe. The molding pie Set in a pressing die having a pressing surface that comes into contact with the front surface of the bulge portion of the pipe, and clamp the outer periphery of the portion of the pipe protruding from the rear surface of the flange at a predetermined small distance from the rear surface of the flange, and press this The die is pressed and moved in the axial direction to form an engagement bulge portion that tightly engages with the inner peripheral surface of the counterbore portion on the outer periphery of the pipe located in the counterbore portion at the rear portion of the insertion hole of the flange,
A method of manufacturing a shaft-sealed nipple with a flange, which comprises a pressing connection step of fixing the molded pipe to a flange.