JP2001021042A - Mechanical pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily insert a connection pipe even in a gasket fastened state, and simultaneously to prevent the falling-off of a nut caused by vibration or the like. SOLUTION: End surface locking parts 16a and 16b are formed in the outside of the axial direction of the tapered part 14 of a joint main body 1, and a projection 36 protruded to the outside of a diameter direction over the inner diameter of the tapered part 14 of the joint main body 1 is integrally formed in the outer surface of a gasket 3. The feeling of fastening moderation is provided because of the presence of a point where fastening torque is suddenly changed by the resistance of the projection 36 of the gasket 3, a force necessary for fastening for preventing the falling-off of a nut 2 is easily perceived, and the excessive diameter reduction of the gasket 3 disabling the insertion of a connecting pipe 5 because of too-much fastening of the nut 2 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical type pipe joint having a joint body, a nut and a packing, and more particularly to a mechanical type pipe joint which can improve the workability of the pipe joint at the time of temporary assembly and at the time of main assembly.

[0002]

2. Description of the Related Art Mechanical pipe joints having at least a joint body, a nut and a packing are excellent in workability in that they can be joined as they are without threading a connecting pipe, have flexibility and elasticity, and have seismic resistance. It has features such as excellent properties. For this reason, mechanical pipe joints are used in various fields such as water supply piping for hot water supply and hot water supply, and air conditioning piping for cooling water or hot water.

[0003] In recent years, as connecting pipe materials and construction methods have been diversified, further improvements in workability and pipe type compatibility have been desired for mechanical pipe joints. Most of the conventional mechanical type pipe joints first remove the nut, washer and packing from the joint body at the time of construction, then attach the nut, washer and packing to the connecting pipe in advance and insert it in the specified position of the joint body, and finally The operation is very complicated because the packing is reduced in diameter by tightening the nut to achieve sealing and retaining. If the connection pipe can be directly inserted into the temporarily assembled mechanical pipe joint in which the nut, washer and packing have been set in the joint body in advance by omitting such attaching and detaching work, the workability will be improved. Requires that the inner diameter of the packing be somewhat larger than the outer diameter of the connecting pipe.

On the other hand, in the field of water supply piping, connection pipes such as steel pipes, vinyl chloride pipes, and polyethylene pipes are used. Many of these pipe types have the same outer diameter or outer diameter even if the nominal diameter is the same. Different tolerances. For example, comparing the nominal outside diameter and the tolerance of the outside diameter of the pipe according to the JIS standard for the nominal diameter 25 of a galvanized steel pipe, a polyethylene pipe for water supply, and a rigid polyvinyl chloride pipe for water supply, the maximum outer diameter is 34 mm of the galvanized steel pipe. ±
The minimum outer diameter is 0.5 mm (ie 34.5 mm maximum), while the minimum outer diameter is 32 mm ± 0.2 mm (ie 31.8 mm minimum) for rigid PVC pipes for water supply, and the maximum and minimum values are There is a considerable gap of 34.5 mm-31.8 mm = 2.7 mm.

As described above, the connecting pipe can be directly inserted into the temporarily assembled pipe joint to improve workability,
In order to be able to cope with the difference in the outer diameter of the connecting pipe and to achieve a more reliable sealing structure and ensure water resistance, the inner diameter of the packing should be set to be somewhat larger than the outer diameter of the connecting pipe, and at the same time the nut should be tightened. It is necessary to easily reduce the diameter of the packing. For this reason, a tapered surface or an R-surface is provided on the contact side of the packing to the joint body, the tapered surface or the R-surface contracting inward in the axial direction.
A packing mounting portion of the joint main body is formed corresponding to the packing shape, and the packing is easily moved inward in the axial direction by tightening the nut, so that the packing is easily reduced in diameter. In addition, since the packing is required to have a diameter reduced enough to hold the connection pipe to the pipe joint by the tightening force of the nut, which is manually tightened, the inner diameter of the joint body at the packing installation point is larger than the outer diameter of the packing. A setting is made to reduce the frictional resistance of the contact surface between the outer surface of the packing and the joint body.

[0006]

The conventional mechanical pipe joint shown in FIG. 14 has a joint body (1), a nut (2), a washer (8), and an end (12) of the joint body (1). ) Is attached to the tapered portion (14) formed on the inner surface of the inner surface and reduced in diameter in the axial direction, and is provided with an elastically deformable packing (3) pressed by the nut (2) via the washer (8). I have. In this pipe joint, the packing (3) is compressed by tightening the nut (2) with respect to the joint body (1) to seal the space between the joint body (1) and the outer surface of the connection pipe.

However, in the pipe joint shown in FIG.
If the packing (3) is configured to reduce the diameter easily, when the nut (2) is tightened with a light tightening force to the fitting body (1) as a temporary assembly of the mechanical pipe fitting, the packing (3) will Packing (3) for elastic deformation without showing resistance
May be excessively reduced in diameter. In this state, as shown in FIG. 15, even if an attempt is made to insert the connecting pipe (5) as the main assembly, the inner diameter of the reduced packing (3) is smaller than the outer diameter of the connecting pipe (5). The connection pipe (5) cannot be inserted into the pipe fitting in the state. On the other hand, if the packing (3) is tightened with such a force that the packing (3) does not move inward in the axial direction in order to prevent excessive diameter reduction of the nut (2), the nut (2) will not be tightened due to insufficient tightening. ) Is easily loosened, the nut (2) falls off from the temporarily assembled pipe joint due to vibration during transportation, etc., resulting in the washer (8) and packing from the joint body (1).
(3) is also separated, causing a problem that reassembly is required at the time of use.

[0008] In view of the above, according to the present invention, by keeping the state of tightening the nut to the joint body constant, the connection pipe can be easily inserted even when the packing is tightened, and at the same time, the nut can be prevented from falling off due to vibration or the like. An object of the present invention is to provide a mechanical type pipe joint having good workability.

[0009]

The mechanical type pipe joint according to the present invention has an end portion (12) having a hollow portion (11) into which a connecting pipe (5) is inserted and an external thread portion (13) formed on an outer peripheral portion. A joint body (1) having a female thread (21) connected to the male thread (13) of the joint body (1), and a nut through which the connection pipe (5) is inserted
(2) and a nut attached to a tapered portion (14) formed on the inner surface of the end portion (12) of the joint body (1) and reduced in diameter in the axial direction, and
An elastically deformable packing (3) pressed by (2) is provided, and the packing (3) is compressed by tightening the nut (2) to the joint body (1) and connected to the joint body (1). Seal between the outer surface of the tube (5). In the present invention, the end face engaging portions (16a, 16b) are formed on the outer side in the axial direction of the tapered portion (14) of the joint main body (1), and the diameter exceeds the inner diameter of the tapered portion (14) of the joint main body (1). A projection (36) projecting outward in the direction is integrally formed on the outer surface of the packing (3).

When the nut (2) is tightened with a force less than a certain tightening force, the projection (36) is engaged with the end face locking portion (16a, 16a, 16b) of the joint body (1).
16b) to prevent the packing (3) from moving inward in the axial direction. Therefore, for the temporary assembly of the mechanical type pipe joint,
When the nut (2) is tightened to the joint body (1) with a light tightening force, the protrusion (36) is locked by the end face locking portions (16a, 16b) of the joint body (1).
In order to prevent the packing (3) from moving inward in the axial direction without elastic deformation due to contact with the nut, place the nut (2) on the tapered part (14) of the joint body (1) and remove the packing (3). The connection pipe (5) can be easily inserted even in the tightened state, and at the same time, the nut (2) can be prevented from falling off due to vibration or the like. At this time, there is a point where the tightening torque suddenly changes due to the resistance of the protrusion (36) of the packing (3), giving a sense of moderation of tightening and tightening to the extent that the nut (2) does not fall off. The required power can be easily detected. Therefore, tighten the nut (2) too much and connect pipe (5)
The packing (3) is not excessively reduced in diameter so that it cannot be inserted.

When the nut (2) is tightened with a force exceeding a certain tightening force, the projection (36) is elastically deformed so that the joint body (1)
The gasket (3) is press-fitted into the tapered portion (3) and can move the packing (3) inward in the axial direction. Therefore, after inserting the connecting pipe (5) into the hollow part (11) of the joint body (1), when the nut (2) is tightened beyond a certain tightening force for this assembly, the protrusion (36 ) Is reduced in diameter and pressed into the tapered portion (3) of the joint body (1) by elastic deformation, so the packing (3) is moved inward in the axial direction, and the joint body (1) and the connection pipe (5) are moved. Can be sealed with the packing (3).

In the embodiment of the present invention, an inner cylindrical surface (15) is formed between the tapered portion (14) of the joint main body (1) and the end surface engaging portions (16a, 16b), and the joint main body (1) is formed. ), An outer cylindrical surface (35) having substantially the same diameter as the inner cylindrical surface (15) is formed axially inside the projection (36) of the packing (3). End face locking part (16a,
16b) and the inner cylindrical surface (15) are brought into contact with the protrusion (36) and the outer cylindrical surface (35) of the packing (3), respectively.
The movement of the packing (3) in the axial direction with respect to the fixed tightening force by the nut (2) can be reliably prevented to a certain state, and a sense of moderation can be obtained stably.

The end locking portions (16a, 16b) are radially locking portions (16a, 16b).
a) or the tapered locking portion (16b), and the tapered locking portion (16b).
The inclination angle of b) should be 30 ° or more with respect to the center axis of the joint body (1).
90 °. When the inclination angle is less than 30 °, packing
Since the elastic deformation of the projection (36) of (3) occurs too easily, the function and effect of the present invention may not be achieved. The shape of the end locking parts (16a, 16b) is the material of the packing (3),
It can be set appropriately according to the shape of (36), the shape of the inner cylindrical surface (15), and the like. A protrusion accommodating portion (17) may be formed adjacent to the end surface locking portion (16a, 16b) of the joint body (1) in the axial direction, and the outer surface of the protrusion (36) of the packing (3) is a protrusion accommodating portion. It may be in contact with the inner surface of the part (17). Further, the cross-sectional shape of the projection accommodating portion (17) is rectangular or arc-shaped. The provision of the protrusion receiving portion (17) facilitates the mounting of the packing (3) to the joint body (1), and at the same time, the falling of the mounted packing (3) and the protrusion (36).
Damage can be prevented. The tapered portion (14) is not limited to a straight section, but may be an arc section.

The projection (36) of the packing (3) has a rectangular cross section,
A combination of an arc or a rectangle and an arc is possible,
Which shape is adopted depends on the degree of the set tightening torque. A radial recess (37) may be formed adjacent to the projection (36) of the packing (3), and the radial recess (37) may be formed with the projection (36).
May be formed on both sides or on either one side. When the radial recess (37) is formed, the projection (36) can be easily elastically deformed, so that the present invention can be applied to the case where the packing (3) having a little flexibility is used. The projections (36) of the packing (3) are formed continuously in the circumferential direction or are formed in plurality in the circumferential direction. When a plurality of protrusions (36) are formed intermittently in the circumferential direction, a plurality of protrusion accommodating portions (17) of the joint body (1) may be formed intermittently at corresponding locations, and may be continuously formed in the circumferential direction. May be formed.

[0015]

FIG. 1 is a block diagram showing an embodiment of the present invention.
13 will be described.

A mechanical pipe joint according to a first embodiment of the present invention shown in FIG. 1 has a hollow portion into which a connecting pipe (5) is inserted.
(11) and a joint body (1) having an end portion (12) formed on the outer periphery with a male thread portion (13), and a female thread portion (21) connected to the male thread portion (13) of the joint body (1). And a taper (14) formed on the inner surface of the end (12) of the joint body (1) and reduced in diameter in the axial direction, and a nut (2) through which the connecting pipe (5) is inserted. And a packing (3) that is elastically deformable and pressed by a nut (2) .The packing (3) is compressed by tightening the nut (2) with respect to the joint body (1) to compress the joint body (1). )
And the outer surface of the connecting pipe (5). A radial locking portion (16a) as an end surface locking portion is formed on the outside of the tapered portion (14) of the joint body (1) in the axial direction, and exceeds the inner diameter of the tapered portion (14) of the joint body (1). The protrusion (36) that protrudes outward in the radial direction
It is integrally formed on the outer surface of (3). Taper part of fitting body (1)
Attach packing (3) to (14), and attach nut (2) via washer (8). Although the present embodiment includes the washer (8), the washer (8) may be omitted if there is no possibility that the packing (3) may be cracked or damaged by tightening the nut (2). The nut (2) is round, hexagonal, octagonal, 10
Any of polygonal nuts such as a square and a dodecagon may be used.

As shown in FIG. 2, the tip of a packing (3) inserted into the joint body (1) in the axial direction is provided with a packing.
An outer tapered surface (34) having an inclination angle of 20 ° to 40 °, preferably 25 ° to 35 ° with respect to the central axis of (3) is formed. The packing (3) does not necessarily have to have the outer tapered surface (34), but the outer tapered surface (34) is used in that the diameter of the packing (3) can be easily reduced by tightening the nut (2). It is more preferable to provide Although not shown, the projection (36) may be formed after the entire packing (3) is formed into an O-ring shape. In other words, the packing (3) is not limited to the shape described herein,
The inner diameter of the packing (3) is larger than the outer diameter of the connecting pipe (5), and when the packing (3) is pushed in, the packing (3) is reduced in diameter and the joint body (1) and the outer surface of the connecting pipe (5) Any shape may be used as long as it can seal between the spaces.

The protrusions (36) on the outer surface of the packing (3) are in a state where the packing (3) is attached to the joint body (1) or the packing (3) is attached to the joint body (1) only by the weight of the packing (3). On the other hand, the packing (3) is provided at a position where it comes into contact with the radial locking portion (16a) of the joint body (1) in a state where the packing (3) is reduced in diameter and the connecting pipe (5) can be inserted by slightly applying pressure. The protrusion (36) of the packing (3) may be any one of a rectangular shape, an arc shape, or a combination of a rectangular shape and an arc shape, and a portion protruding from the outer periphery of the packing (3) is a diameter of the joint body (1). Other shapes are possible as long as they contact the direction locking portion (16a). The dimensions of the protrusion (36) are such that by rotating the nut (2) by hand tightening, a resistance is generated when a tightening force is applied to the protrusion (36), and the nut (2) is further rotated by hand tightening. As a result, the protrusion (36) yields to the tightening force and is elastically deformed and moves inward in the axial direction of the joint body (1) so that the packing (3) can be reduced in diameter, and the material forming the packing (3) can be used. Can be set as appropriate depending on the hardness of the joint, the size of the joint body (1), and the like. In other words, the force required to push the packing (3) inward in the axial direction of the joint body (1) can be arbitrarily set according to the size and shape of the projection (36).

As shown in FIG. 3, an inner cylindrical surface (15) is provided between the tapered portion (14) of the joint body (1) and the radial locking portion (16a).
Is formed, and an outer cylindrical surface (35) having substantially the same diameter as the inner cylindrical surface (15) of the joint body (1) is formed axially inside the projection (36) of the packing (3). Radial locking part (16a) of fitting body (1)
By contacting the inner cylindrical surface (15) with the protrusion (36) of the packing (3) and the outer cylindrical surface (35), respectively, the packing (3) is pressed against the fixed tightening force by the nut (2). The movement inside the axial direction can be reliably prevented to a certain state, and a sense of moderation can be obtained stably.

In the state shown in FIG. 4, when the force for pushing the packing (3) toward the inside in the axial direction of the joint body (1) is exerted by tightening the nut (2), the diameter of the joint body (1) is reduced. The protrusion (36) in contact with the direction locking portion (16a) becomes a resistance and increases the tightening torque, so that the tightening state of the nut (2) can be easily determined. When the nut is further tightened with a larger tightening torque, the protrusion (36) is elastically deformed as shown in FIG. 5 and is pressed into the inner cylindrical surface (15) or the tapered portion (14) of the joint body (1), and the packing is pressed. (3) is reduced in diameter and closely adheres to the outer surface of the connecting pipe (5) to seal between the joint body (1) and the outer surface of the connecting pipe (5).

That is, in the present embodiment, when the nut (2) is tightened with a force less than a predetermined tightening force, the projection (36) comes into contact with the radial locking portion (16a) of the joint body (1). To prevent the packing (3) from moving inward in the axial direction. Therefore, when the nut (2) is tightened with a light tightening force to the joint body (1) for the temporary assembly of the mechanical type pipe joint, the protrusion (36) becomes the joint body (1).
In order to prevent the packing (3) from moving inward in the axial direction without contacting the radial locking part (16a)
Place the nut (2) on the taper part (14) of (1) and packing (3)
The connection pipe (5) can be easily inserted even when the nut is tightened, and at the same time, the nut (2) can be prevented from falling off due to vibration or the like.
At this time, there is a point where the tightening torque suddenly changes due to the resistance of the protrusion (36) of the packing (3), giving a sense of moderation of tightening and tightening to the extent that the nut (2) does not fall off. The required power can be easily detected. Therefore, the packing (3) is not excessively reduced in diameter so that the connection pipe (5) cannot be inserted because the nut (2) is excessively tightened.

When the nut (2) is tightened with a force exceeding a certain tightening force, the projection (36) is elastically deformed so that the joint body (1)
The gasket (3) is press-fitted into the tapered portion (3) and can move the packing (3) inward in the axial direction. Therefore, after inserting the connecting pipe (5) into the hollow part (11) of the joint body (1), when the nut (2) is tightened beyond a certain tightening force for this assembly, the protrusion (36 ) Is reduced in diameter and pressed into the tapered portion (3) of the joint body (1) by elastic deformation, so the packing (3) is moved inward in the axial direction, and the joint body (1) and the connection pipe (5) are moved. Can be sealed with the packing (3).

The mechanical type pipe joint shown in FIG. 6 has a lock ring (4) having a tapered portion whose diameter decreases outward in the axial direction, instead of the nut (2) shown in FIG.
Nut with inner taper that abuts taper in (4)
(2). That is, the present invention can be applied to a mechanical pipe joint including the lock ring (4).

In the second embodiment of the present invention shown in FIG. 7, a tapered locking portion (16b) as an end face locking portion (16a, 16b) is provided at an end (12) of the joint body (1). Provided. The angle of inclination of the tapered locking part (16b) is 3 degrees with respect to the center axis of the joint body (1).
0 ° to 90 °. The protrusion (36) of the packing (3) may have an outer tapered surface corresponding to the tapered locking portion (16b) of the joint body (1), but regardless of the tapered locking portion (16b). The cross section may be rectangular, arcuate, or another shape. That is, the radial locking portion (16a) shown in FIG. 1 and the tapered locking portion shown in FIG.
Including both (16b), the shape of the end locking parts (16a, 16b) depends on the material of the packing (3), the shape of the projection (36), and the inner cylindrical surface.
It can be set appropriately according to the shape and the like of (15).

In the third embodiment of the present invention shown in FIG. 8, a radial locking portion (16) as an end surface locking portion of the joint body (1) is used.
A projection accommodating portion (17) is formed adjacent to the outer side in the axial direction of (a). In FIG. 8, the outer surface of the projection (36) of the packing (3) is brought into contact with the inner surface of the projection accommodating portion (17), but even if the outer surface of the projection (36) and the inner surface of the projection accommodating portion (17) are separated from each other. Good. Further, in FIG. 8, the cross-sectional shape of the projection accommodating portion (17) is rectangular, but may be arc-shaped or other shapes. The provision of the protrusion receiving portion (17) facilitates the mounting of the packing (3) to the joint body (1), and at the same time, the falling of the mounted packing (3) and the protrusion (36).
Damage can be prevented. Further, as shown in FIG. 8, in the present invention, the tapered portion (14) of the joint main body (1) is not limited to a linear section, but may be an arc-shaped section.

In the present invention, the cross section of the projection (36) of the packing (3) is not limited to a rectangular shape. For example, as in the first modification of the packing (3) shown in FIG. 9, the cross section of the projection (36) may be formed in an arc shape, and as in the second modification of the packing (3) shown in FIG. A combination of a rectangular shape and an arc shape may be used, and other shapes can be applied. However, which cross-sectional shape is adopted depends on the set tightening torque. Further, the protrusions (36) of the packing (3) may be formed continuously in the circumferential direction, and a plurality of protrusions (36) are intermittently formed in the circumferential direction as in a third modification of the packing (3) shown in FIG. It may be formed. The number of the intermittently formed projections (36) can be appropriately set according to the required tightening torque. When a plurality of protrusions (36) are formed intermittently in the circumferential direction, a plurality of protrusion accommodating portions (17) of the joint body (1) may be formed intermittently at corresponding locations, and may be continuously formed in the circumferential direction. May be formed.

Packing shown in FIGS. 12 and 13, respectively.
In the fourth and fifth modifications of (3), the protrusions (3
A radial recess (37) is formed adjacent to 6). Radial recess (3
7) may be formed only on one side of the projection (36) as shown in FIG. 12, or may be formed on both sides of the projection (36) as shown in FIG. When the radial recess (37) is formed, the elastic deformation of the projection (36) is facilitated, so that the packing (3) is slightly less flexible.
It can be applied to the case where is used.

[0028]

[Embodiment 1] The packing (3) shown in FIG.
(Acrylonitrile butadiene rubber), inner diameter: d1 = 28.4 mm, outer diameter: D1 = 36 mm, length: l = 12 mm
And the inclination angle of the outer tapered surface (34) with respect to the central axis: θ
= 30 °. Distance from the narrow end of the outer tapered surface (34): H1 = 7 mm.
(36) was formed continuously in the circumferential direction. The protrusion (36) had a radial length: H2 = 1.5 mm and an axial length: H3 = 1.2 mm. In the following Examples and Comparative Examples, unless otherwise specified,
The inner shape, outer diameter, length, other dimensions and material of each packing (3) were the same as those of the packing (3) in FIG. In order to clarify the effect of the projection (36) provided on the packing (3), the embodiment using the packing (3) having the projection (36) shown in FIG. 2 does not have the projection shown in FIG. Using the packing (3) as a comparative example, the packing (3), the washer (8) and the nut (2) were pushed into the joint body (1) in a state shown in FIGS. When the connecting pipe (5) cannot be inserted due to the reduced diameter of
It was measured as the tightening torque of (2). As a result, in the packing (3) without the protrusion (36) shown in FIG. 14, the tightening torque is 0.6.
The connection pipe (5) could not be inserted at N · m. On the other hand, in the packing (3) of the present invention shown in FIG. 2, the connection pipe (5) could not be inserted with a tightening torque of 1.5 N · m. The tightening torque before the nut (2) comes into contact with the packing (3) and the washer is 0.5 Nm, and the packing (3) without the protrusion (36) in FIG.
Pushing of packing (3) due to rotation of can hardly be detected.
In contrast, the packing (3) of the embodiment of FIG.
When the packing (3) is pushed in, the tightening torque of the nut (2) increases more than twice, so the pushing of the packing (3) can be easily detected and the packing (3) is not pushed in more than necessary. , When the packing (3) starts to be pushed in,
Since the rotation of (2) can be stopped, the insertability of the connection pipe (5) was not hindered. At this point, the temporary assembly was completed, and when the connecting pipe (5) was further connected as the final assembly, a tightening torque of 1.5 Nm or more could be easily applied by hand tightening. As a result, the packing (3) is reduced in diameter, and the outer surface of the connection pipe (5) comes into contact with the inner surface of the packing (3) so that the connection pipe is not connected.
It was confirmed that (5) could be held, a watertight structure was formed by tightening using a tool such as a pipe wrench, and no leakage occurred up to a water pressure of 10 MPa.

[Embodiment 2] In the packing (3) shown in FIG. 9, the distance from the narrow side end of the outer tapered surface (34): H1 = 7.8.
A 1.5R arc-shaped projection (36) was continuously provided in the circumferential direction at the position of mm. The tightening torque measured in the same manner as in Example 1 was 1.0 N · m, a sufficient value.

Embodiment 3 In the packing (3) shown in FIG. 10, the distance from the narrow side end of the outer tapered surface (34) is H1 = 7 m.
A projection (36) having a rectangular shape and an arc shape was continuously provided in the circumferential direction at the position of m. The protrusion (36) has a radial length of H2 = 1.
5 mm, length in the axial direction: H3 = 0.5 mm. An arc of 1.5R was formed at the position where the projection (36) was formed from the outer surface of the joint body (1). The tightening torque measured in the same manner as in Example 1 was 1.3 N
・ It was m.

[Embodiment 4] In the packing (3) shown in FIG. 11, the distance from the narrow side end of the outer tapered surface (34) is H1 = 7.
Four 1.5R arc-shaped protrusions (36) were formed intermittently in the circumferential direction at 8 mm positions. That is, a packing (3) having the same cross-sectional shape as in Example 2 was prepared except that the protrusions (36) were formed intermittently in the circumferential direction. The tightening torque measured in the same manner as in Example 1 was slightly smaller at 0.8 Nm, but was a sufficient value for the comparative example (tightening torque 0.5 Nm).

[0032]

According to the present invention, the connection pipe can be easily inserted even when the packing is tightened, and at the same time, the nut can be prevented from falling off due to vibration or the like. Therefore, in the mechanical type pipe joint using packing that can be easily reduced in diameter, the connecting pipe can be directly inserted into the pipe joint in a temporarily assembled state, so that the workability can be improved and the connecting pipe having various outer diameters can be supported. Achieving a highly reliable sealing structure.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a mechanical type pipe joint of the present invention.

FIG. 2 is a detailed sectional view of a packing used in FIG.

FIG. 3 is an enlarged sectional view showing a relationship between a packing and an end of a joint body.

FIG. 4 is an enlarged cross-sectional view showing a state where the packing abuts on an end of the joint body.

FIG. 5 is an enlarged sectional view showing a state where the nut is further tightened from the state of FIG. 4;

FIG. 6 is a cross-sectional view of a mechanical pipe joint according to the present invention having a lock ring.

FIG. 7 is an enlarged sectional view showing a second embodiment of the mechanical pipe joint of the present invention.

FIG. 8 is an enlarged sectional view showing a third embodiment of the mechanical pipe joint of the present invention.

FIG. 9 is a sectional view showing a first modification of the packing.

FIG. 10 is a sectional view showing a second modification of the packing.

FIG. 11 is a plan view showing a third modification of the packing.

FIG. 12 is an enlarged sectional view showing a fourth modification of the packing;

FIG. 13 is an enlarged sectional view showing a fifth modification of the packing.

FIG. 14 is a sectional view showing a conventional mechanical pipe joint.

FIG. 15 is a detailed sectional view showing a case where a connection pipe cannot be inserted into the pipe joint of FIG. 14;

[Explanation of symbols]

(1) Fitting body, (2) Nut, (3) Packing, (4) Lock ring, (5) Connection pipe, (8)
・ ・ Washer, (11) ・ ・ Cavity, (12) ・ ・ End,
(13) ・ ・ Male thread part, (14) ・ ・ Taper part, (15) ・ ・ Inner cylindrical surface, (16a) ・ ・ Radial locking part (end face locking part),
(16b) ・ ・ Tapered locking part (end face locking part), (17) ・
・ Protrusion receiving part, (21) ・ ・ Female thread part, (34) ・ ・ Outer taper surface, (35) ・ ・ Outer cylindrical surface, (36) ・ ・ Protrusion, (3
7) ・ ・ Radial recess,

Continued on the front page (72) Inventor Takashi Miyake 4-14-1, Suehiro, Kumagaya-shi, Saitama Pref. Inside Riken Kumagaya Office (72) Inventor Hideyuki Kurosawa 4-1-1, Suehiro, Kumagaya-shi, Saitama Co., Ltd. RIKEN Kumagaya Plant F-term (reference) 3H014 BA06 GA05 3J040 AA13 BA03 EA01 EA16 HA03 HA08 HA30

Claims (10)

[Claims] A joint body having an end formed with a hollow portion and an external thread portion formed on an outer peripheral portion for inserting a connection tube, a female thread portion connected to a male thread portion of the joint body is formed, and the connection tube is inserted. And a resiliently deformable packing that is mounted on an inner surface of an end portion of the joint body and is reduced in diameter in the axial direction and is pressed by the nut, and tightens the nut to the joint body. In the mechanical type pipe joint which seals between the joint body and the outer surface of the connection pipe by compressing the packing by forming the end face locking part in the axial direction outside of the taper part of the joint body, the taper part of the joint body is formed. A mechanical type pipe joint characterized in that a projection projecting radially outward beyond an inner diameter is integrally formed on an outer surface of a packing. 2. An inner cylindrical surface is formed between the tapered portion of the joint main body and the end surface engaging portion, and an outer cylindrical surface having substantially the same diameter as the inner cylindrical surface of the joint main body is formed axially inside the projection of the packing. The mechanical type pipe joint according to claim 1. 3. The mechanical pipe joint according to claim 1, wherein the end surface locking portion is a radial locking portion or a tapered locking portion. 4. The mechanical pipe joint according to claim 3, wherein an inclination angle of the tapered locking portion is 30 ° to 90 ° with respect to a center axis of the joint body. 5. The joint housing according to claim 1, wherein a projection accommodating portion is formed adjacent to the end face engaging portion of the joint body on the outside in the axial direction.
The mechanical type pipe joint according to the paragraph. 6. The mechanical pipe joint according to claim 5, wherein an outer surface of the projection of the packing comes into contact with an inner surface of the projection accommodating portion. 7. The tapered portion has an arc-shaped cross section.
7. The mechanical type pipe joint according to any one of items 6 to 6. 8. The mechanical type pipe joint according to claim 1, wherein the cross section of the projection of the packing has a rectangular shape, an arc shape, or a combination of a rectangular shape and an arc shape. 9. The mechanical pipe joint according to claim 1, wherein a radial recess is formed adjacent to the projection of the packing. 10. The projection of the packing is formed continuously in the circumferential direction or a plurality of protrusions are formed intermittently in the circumferential direction.
The mechanical type pipe joint according to any one of the above.