JPH08145251A - Pipe connecting device - Google Patents

Abstract

PURPOSE: To prevent the damage of an annular packing during insertion of a metallic pipe. CONSTITUTION: A pipe connection device is of a type wherein a screw cylinder 2 is joined in a screwed-in state with the pipe insertion side of a main body 1 consisting of a first hole part 11 on the pipe insertion side for inserting a metallic pipe and a second small hole part 12 continued thereto, a ring 3 made of a metal having a taper part 31 is contained in a first hole part 11 and an annular packing 4 to ensure airtightness with the metallic pipe is arranged in the main body 1, and by fastening the screw cylinder 2 in a metallic pipe- inserted state, a ring 3 made of a metal is compressed in a flat state and the peripheral part thereof is cut through the metallic pipe and the ring is fixed in an antislip state. A ring 3 made of a metal is constituted in such a manner that a taper part 31 where diameter is expanded toward the interior is provided, and the annular packing 4 is located between the taper part 31 and a boundary end face 13. The inside diameter thereof is increased to a value larger than that of the metallic pipe, and a gap between the second hole part 12 and the metallic pipe inserted in the second hole part is sized to be lower than the size of the annular packing 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe connecting device for fixing a metal straight pipe in an airtight state on the outer periphery.

[0002]

2. Description of the Related Art The pipe joint shown in FIG. 1 has already been proposed as a pipe joint used for gas pipes and the like. In this case, a substantially tubular main body (1) having an insertion hole (1a) for inserting a metal pipe (P) and a screw cylinder (2) externally screwed to the pipe insertion side are formed. The insertion hole (1a) includes a first hole portion (11) on the pipe insertion side and a second small diameter hole portion (1) following the first hole portion (11).
2) and formed.

A metal ring (3) having a convex V-shaped cross section is housed in the first hole (11). Further, the boundary end face (1) between the first and second hole portions (11) and (12) is
The O-ring (4a) is housed in the holding hole (19) cut from 3) to the side of the second hole (12), and the inner peripheral portion of the O-ring (4a) is the second hole. It projects inward from the peripheral wall of (12). A pressure ring (R) for pressing the metal ring (3) is interposed between the flange portion (29) of the screw cylinder (2) and the metal ring (3). There is.

In this case, when the metal tube (P) is inserted into the main body (1) and the screw tube (2) is tightened, the metal ring (3) and the pressure ring (R) and the boundary end surface (13) are inserted. ) And is compressed and flattened in the axial direction, and the inner peripheral portion thereof bites into the metal pipe (P). As a result, the metal pipe (P) is fixed in the retaining state. Further, in this state, the O-ring (4a) is tightly fitted on the metal pipe (P), so that the metal pipe (P) is in a hermetically sealed state on the outer periphery. With this one, just tighten the screw tube (2),
This connection work is easy because a metal pipe (P) can be connected. Further, since the inner peripheral portion of the metal ring (3) is made to bite into the metal pipe (P), the retaining strength of the metal pipe (P) becomes large.

However, in this one, when the metal pipe (P) is inserted into the first and second hole portions (11) and (12), the metal pipe (P) is strongly attached to the O-ring (4a). Because of the contact, this O
The problem remains that the ring (4a) is easily damaged. In order to ensure the airtight state, the inside diameter of the O-ring (4a) is set smaller than the outside diameter of the metal pipe (P), and the end of the metal pipe (P) is inserted into the O-ring at the time of insertion. In addition to (4a),
While the metal tube (P) compresses the cross section of the O-ring (4a),
This is because it slides on the ring (4a). If the O-ring (4a) is damaged, the airtightness of the pipe joint is significantly reduced.

[0006]

Technical Problem The present invention has been made in view of such a point, and "A through hole for inserting a metal tube (P) is formed, and the first hole portion on the tube insertion side ( 11) and a second small-diameter second hole portion (12) continuous with the main body (1), a screw cylinder (2) screwed to the pipe insertion side of the main body (1), and the first
The metal ring (3) housed in the hole (11) and provided with the taper portion (31) and the metal pipe (P) inserted through the main body (1) and the screw cylinder (2). The above-mentioned subject to ensure airtightness
(1) is equipped with an annular packing (4), and the screw cylinder (2) is tightened and the first and second hole portions (11) (1)
By compressing and flattening the metal ring (3) between the boundary end face (13) between 2), the inner peripheral portion of the metal ring (3) bites into the inserted metal pipe (P) and is removed. In the “pipe connecting device fixed in a stopped state”, it is an object to prevent the annular packing (4) from being damaged when the metal pipe (P) is inserted into the main body (1).

[0007]

[Technical Means] The technical means of the present invention taken in order to solve the above-mentioned problem is that "a taper portion (31) for expanding the diameter of a metal ring (3) inward is provided at an inner end. The annular packing (4) is provided between the tapered portion (31) and the boundary end surface (13) and has an inner diameter larger than that of the metal pipe (P). Part (12) and metal tube inserted into it
The gap with (P) is set smaller than the cross section of the annular packing (4). "

[0008]

The above technical means of the present invention operates as follows. Insert the metal tube (P) from the screw tube (2) side
When inserted into the second holes (11) (12), this metal pipe (P)
The screw tube (2), the metal ring (3) and the annular packing (4) are inserted in this order. At this time, the annular packing
Since the inner diameter of (4) is set larger than that of the metal pipe (P), the metal pipe (P) and the annular packing (4) do not come into contact with each other.

After that, when the screw cylinder (2) is tightened, the metal ring (3) is compressed and flattened between the screw cylinder (2) and the boundary end face (13). In this compression flattening, the metal ring
(3) is a configuration in which the taper portion (31) that expands in diameter inward is provided at the inner end, so this taper portion (31)
After being inserted between the annular packing (4) and the peripheral wall of the first hole portion (11), the annular packing (4) is pressurized to the inner peripheral side and inward. As a result, the annular packing (4) is
The diameter is reduced. Then, when the size becomes smaller than the inner peripheral edge of the boundary end face (13), it is pushed into the second hole portion (12). At this time, since the gap between the second hole portion (12) and the metal pipe (P) inserted therein is set to be smaller than the cross section of the annular packing (4), the annular packing (4)
However, it is in a state of being press-fitted between the second hole portion (12) and the metal pipe (P). As a result, the metal pipe (P) becomes airtight on the outer periphery.

Further, by the compression flattening, the metal ring
The inner circumference of (3) bites into the metal pipe (P). The metal ring (3) axially engages with the screw cylinder (2). As a result, the metal pipe (P) is fixed to the main body (1) so as not to come out.

[0011]

[Effects] The present invention having the above-described structure has the following unique effects. In this case, when inserting the metal pipe (P) into the main body (1), the metal pipe (P) and the annular packing (4) do not come into contact with each other, so that the annular packing (4) is prevented from being damaged. .
Therefore, the airtightness does not deteriorate due to the damage.

Further, the annular packing (4) has the second hole (12).
Since the outer peripheral airtight state is obtained by press-fitting between the peripheral wall and the metal pipe (P), it is possible to secure the airtight performance equivalent to or better than that of the conventional example.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, as shown in FIG. 2, a male screw portion is provided at one end.
This is carried out on a pipe joint having a structure in which a screw cylinder (2) is screwed into the other end of a substantially cylindrical main body (1) provided with (16).

[Regarding the Configuration of Each Part] The main body (1) is
A large-diameter main cylinder (15) having a hexagonal outer peripheral portion is continuous with the male screw portion (16), and the inner peripheral region of the main body (1) is connected to the metal pipe (P). It is an insertion hole (1a) for inserting it. The insertion hole (1a) is formed in a certain range from the end of the main cylinder part (15) opposite to the male screw part (16).
It is composed of a hole portion (11) and a second hole portion (12) of a small diameter continuous with the hole portion.

A female screw portion (17) for screwing the screw cylinder (2) is formed in a certain range from the open end of the first hole portion (11). Inward of 17), the first
A taper hole (14) is formed between the second hole (11) and (12) and the boundary end face (13) of which the diameter is reduced inward.
Further, the second hole portion (12) is an enlarged hole portion (12a) whose diameter is larger than the inner side of the boundary end surface (13) in a certain range.
The inner diameter of the boundary end face (13) is set to about the center diameter of the cross section of the O-ring (4a) described later. The screw cylinder (2) is
The hexagonal head (23) for supporting the tightening tool is continuous with the screw body part (22) that is a screwing part with the female screw part (17), and the screw body part (22) will be described later. The pressure cylinder part (21) for pressurizing the metal ring (3) is continuous.

A metal ring (3) having a convex V-shaped cross section on the inner peripheral side is housed in the tapered hole portion (14), and the inner tapered ring is formed. The part becomes the above-mentioned tapered part (31). The inner diameter of the metal ring (3) is set to be slightly larger than the outer diameter of the metal pipe (P), and the radial width of the metal ring (3) in the compressed and flattened state is the above. It is configured to be slightly larger than the radial distance between the outer peripheral edge of the boundary end face (13) and the metal pipe (P) inserted in the main body (1).

Further, the taper portion (3) of the metal ring (3) is
Between the 1) and the boundary end face (13), the above-mentioned annular packing (4)
The O-ring (4a) is interposed. This O-ring
The inner diameter of (4a) is set to be about 0.9 mm larger than the outer diameter (15.9 mm) of the metal tube (P). The outer peripheral portion of the O-ring (4a) is in contact with the peripheral wall of the small diameter portion of the tapered hole portion (14).

[Practical Connection of Metal Pipe (P)] When connecting the metal pipe (P) to the pipe joint having the above-mentioned structure, first attach the metal pipe (P) from the screw cylinder (2) side. (1) Insert it into the second hole (1) as shown by the chain double-dashed line in the figure.
It is located inward of the enlarged hole (12a) in 2). At the time of this insertion, the inside diameter of the O-ring (4a) in the tapered hole portion (14) is set to be larger than the outside diameter of the metal pipe (P). Therefore, the metal pipe (P) and the O-ring (4a) are ) Does not contact.

After that, the screw cylinder (2) is tightened. Then
The pressurizing cylinder part (21) of the screw cylinder (2) clamps the metal ring (3) with the boundary end face (13). This metal ring
Since (3) has the above-mentioned "V" cross section, it is compressed and flattened by the clamping pressure. During this compression flattening, the tapered portion (31) of the metal ring (3) interrupts between the O ring (4a) and the peripheral wall of the tapered hole portion (14), whereby the O
The diameter of the ring (4a) is reduced (state of FIG. 3). Further, since the O-ring (4a) is also pressed inward by the taper portion (31), the outer diameter of the O-ring (4a) decreases due to the diameter reduction.
When it becomes smaller than the inner diameter of (3), the enlarged hole (12
a) It is pushed in. At this time, since the inner diameter of the boundary end face (13) is set to about the center diameter of the cross section of the O-ring (4a), the diameter of the O-ring (4a) is slightly reduced, and the enlarged hole (12a) is formed. ) Will be pushed inside. And, the radial width of the cross section of the O-ring (4a) is equal to the enlarged hole portion.
Since it is set to be larger than the radial distance between the peripheral wall of (12a) and the metal pipe (P) inserted in the second hole (12), this O-ring (4a) is It will be in a state of being press-fitted into the metal pipe (P). As a result, the metal pipe (P) becomes airtight on the outer periphery.

Further, the width of the metal ring (3) in the radial direction is expanded by the compression flattening, but the metal ring (3) and the tapered hole portion (14) are set to have the above dimensional relationship. Therefore, in the metal ring (3), the outer peripheral portion is in contact with the tapered hole portion (14) and the inner peripheral portion is reduced.
As a result, as shown in FIG. 4, the inner peripheral portion is a metal pipe.
Cut into (P) all around. This axial engagement force at the bite also causes the screw tube (2) and the metal ring to
Due to the axial engagement with (3), the metal pipe (P) is the main (1)
It will be fixed in a state that it will not be pulled out. In this case, since the airtightness is secured even in the biting portion, the airtightness of the pipe joint is further improved.

Further, in this case, since the accommodating portion of the metal ring (3) is the tapered hole portion (14), the connected metal pipe (P) can be removed or the metal pipe (P) can be removed. When changing the fixing position of the, loosen the screw tube (2)
(3) is released smoothly. Also, this metal ring
(3) Smooth removal when replacing. [Modification] The metal ring (3) is not limited to the above V-shaped cross section, and as long as it has the above-described tapered portion (31) at its inner end, May be configured. For example, as shown in FIG. 5, a bellows shape may be used and the inner end thereof may be a taper portion (31). Further, the metal ring (3) may be a ring body composed only of the tapered portion (31) as shown in FIG. Furthermore, the tapered portion (31) is
As long as it is tapered as a whole, for example, a structure in which a ring body is divided into a plurality of pieces may be provided at the inner end portion. Even in these cases, the same operation as that of the above-described embodiment is achieved.

.. In the above embodiment, the annular packing (4)
Is the O-ring (4a), but needless to say, it is not limited to this. ． The structure for pressurizing the screw cylinder (2) against the metal ring (3) may be a structure other than the above embodiment, for example, the same structure as the above-mentioned conventional example (see FIG. 1). As for the main body (1), other configurations can be adopted as long as the first and second hole portions (11) and (12) are provided.

.. In the above embodiment, the pipe joint is carried out, but in addition to this, if it is a device for connecting a pipe,
The present invention can be implemented.

[Brief description of drawings]

FIG. 1 is an explanatory view of a pipe joint in a conventional example.

FIG. 2 is a sectional view of a pipe joint according to an embodiment of the present invention.

FIG. 3 is an explanatory view of main parts in a state where the diameter of the annular packing (4) is reduced.

[Fig. 4] Cross-sectional view of the state in which the metal pipe (P) is completely connected to this pipe joint

FIG. 5: Modification of the metal ring (3)

FIG. 6

[Explanation of symbols]

 (P) ・ ・ ・ Metal tube (11) ・ ・ ・ First hole (12) ・ ・ ・ Second hole (3) ・ ・ ・ Metal ring (31) ・ ・ ・ Tapered part (2) ・ ・・ Screw cylinder (4) ・ ・ ・ Annular packing (13) ・ ・ ・ Boundary end face

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Minoru Sakamoto 4-1-2, Hirano-cho, Chuo-ku, Osaka City Osaka Gas Co., Ltd. (72) Izumi Nishimura 4-1-2, Hirano-cho, Chuo-ku, Osaka In Osaka Gas Co., Ltd. (72) Inventor, Hisako Goto, 4-1-2 Hirano-cho, Chuo-ku, Osaka City In Osaka Gas Co., Ltd.

Claims (4)

[Claims] 1. An insertion hole for inserting a metal pipe (P) is formed, and the insertion hole is formed from a first hole portion (11) on a pipe insertion side and a second hole portion (12) having a small diameter continuous with the first hole portion (11). The main body (1) thus constructed, a screw cylinder (2) screwed into the tube insertion side of the main body (1), and a taper portion (31) housed in the first hole (11) are provided. In order to ensure airtightness between the metal ring (3) and the metal pipe (P) inserted through the main body (1) and the screw tube (2), the main body (1)
And the annular packing (4) provided in the
By tightening (2) and flattening the metal ring (3) between this and the boundary end face (13) between the first and second hole portions (11) and (12), In a pipe connecting device in which the inner peripheral portion of the metal pipe (P) is inserted into the inserted state to fix the metal pipe (P) in a retaining state, the diameter of the metal ring (3) is enlarged inward. An annular packing is provided with a tapered portion (31) provided at the inner end.
(4) is interposed between the tapered part (31) and the boundary end face (13), and has an inner diameter larger than that of the metal pipe (P), and is inserted into the second hole part (12) and this. A pipe connecting device in which the gap between the metal pipe (P) and the metal pipe (P) is set smaller than the cross section of the annular packing (4). 2. The pipe connection according to claim 1, wherein the annular packing (4) is an O-ring (4a), and the inner diameter of the boundary end face (13) is set to about the center diameter of the cross section of the O-ring (4a). apparatus. 3. The pipe connecting device according to claim 1, wherein the metal ring (3) is formed in a convex V-shaped cross section on the inner peripheral side. 4. The metal ring (3) is attached to the tapered portion (31).
The pipe connecting device according to claim 1 or 2, which is a ring body composed of only one.