JP2015078768A - Pipe fitting - Google Patents

Abstract

An object of the present invention is to provide a pipe joint that has a small number of parts and can be easily tightened. A tubular joint main body having an insertion portion or a male screw portion on the outer periphery, and a cylindrical shape having a female screw portion screwed into a slide portion or a male screw portion for sliding the insertion portion of the joint main body portion inward. The joint body portion has a joint body taper portion whose diameter is expanded toward the nut portion side on the inside, and the nut portion has a nut taper portion whose diameter is expanded toward the joint body portion on the inside, It has a cylindrical seal member disposed from the joint main body taper portion to the nut taper portion, and the seal member is inserted into the joint main body portion and the nut portion in a state where a pair of pipes connected to the inside are inserted from the openings on both sides. And a pair of sealing portions that are respectively inserted into the outer peripheral portions of the pipe members on both sides and a pair of seal portions that are pressed against and sealed to the outer peripheral portions. [Selection] Figure 1

Description

  The present invention relates to a pipe joint for connecting a pair of pipes in a butt shape, and is particularly suitable for connecting pipes for refrigerants and refrigerators.

In the field of refrigerant piping used for air conditioning equipment, metal pipes such as copper pipes are generally used in order to prevent deterioration and erosion due to refrigerant and to withstand high-pressure refrigerant.
For the connection of copper pipes, brazing has been conventionally performed, but in recent years, joints that can be mechanically connected have been adopted because there is a risk of fire or the like.
The products that are currently on the market include the product name “Fireless Joint” manufactured by Inaba Denki Sangyo Co., Ltd., the product name “Otsu-kun” manufactured by Higashio Mec Co., Ltd., and the product name “Rock Joint” manufactured by Sando Co., Ltd. Etc.
However, all of the products currently on the market are ones in which a copper pipe is inserted into a cylindrical joint body having a threaded portion on both sides, and each pipe is tightened and connected with an individual nut.
In such a joint, two nuts are necessary in addition to the joint body, and screwing or the like is necessary on both sides of the joint body, resulting in high material costs and processing costs.
Moreover, since it is necessary to tighten two nuts as a pipe tightening operation, there is a problem that the number of work steps increases.
Patent Documents 1 and 2 disclose a bite type pipe joint composed of a pair of joint main bodies and a tightening body, but are tightened by a wound coil and can withstand a refrigerant or the like because a ring-shaped packing is required. It is not a thing.

Japanese Utility Model Publication No. 52-29617 Japanese Utility Model Publication No. 52-67018

  It is an object of the present invention to provide a pipe joint that has a small number of parts and can be easily fastened.

The pipe joint according to the present invention includes a tubular joint main body portion having an insertion portion or a male screw portion on the outer periphery, and a female screw portion screwed into a slide portion or a male screw portion for sliding the insertion portion of the joint main body portion inward. The joint body portion has a joint body taper portion whose diameter is expanded toward the nut portion side on the inside, and the nut portion is a nut taper portion whose diameter is expanded toward the joint body portion on the inside. And a tubular seal member disposed between the joint body taper portion and the nut taper portion, and the seal member is inserted into the joint body in a state where a pair of pipes connected to the inside are respectively inserted from the openings on both sides. It is characterized by having a pair of retaining portions that are reduced in diameter by sliding contraction or tightening between the nut portion and the nut portion and are respectively inserted into the outer peripheral portions of the pipes on both sides, and a pair of seal portions that are pressed against and sealed to the outer peripheral portions, respectively. To do.
The present invention is characterized in that the diameter of the seal member is reduced by reducing the distance between the joint main body portion and the nut portion, and may be either slide fastening or screw fastening.
The pipe joint according to the present invention is suitable for refrigerant pipes for air conditioning equipment, oil pipes for refrigerators, and the like, but there is no limit to the use.
The joint body part, the nut part, and the seal member are all made of metal, and for example, a brass material or a bronze material is used.
Copper pipes are generally used as refrigerant pipes and oil pipes.

In the pipe joint according to the present invention, it is preferable that the taper angle between the joint main body taper portion and the nut taper portion is not intended.
Insert the pipe joints from both sides of the pipe joint so that they are in contact with each other, and insert or screw together the joint body and nut using a compression tool, wrench, or spanner. The end portion of the seal member enters and shrinks along the back side, while the end portion of the seal member enters and shrinks along the nut taper portion on the nut portion side.
When the joint body and nut part are fastened in a sliding manner, their taper parts may be in mutual shapes, but when threaded fastening, the taper angle of the joint body taper part and nut taper part is symmetric. Then, as schematically shown in FIG. 7A, the tightening torque due to the joint main body side taper and the tightening torque due to the nut side taper are generated simultaneously, and the combined force of these two becomes high.
This is not a problem for small-sized pipe joints, but for relatively large-sized pipe joints, tightening work becomes difficult if the resultant force is large.
On the other hand, when the taper angle between the joint main body taper portion and the nut taper portion is asymmetrical, for example, when the joint main body side taper angle is initially looser than the nut side taper angle and is abrupt from the middle, it is schematically shown in FIG. As shown, the tightening torque of the nut side taper increases first, and the tightening torque of the main body side taper increases later, so that the resultant force is smaller than the state of FIG. Tightening work becomes easier.
Although a specific taper shape example and a tightening torque increase example will be described later, the taper portion in which the retaining portion is in sliding contact and the taper portion in which the seal portion is in sliding contact are different in two or more taper shapes. And the resultant force of tightening torque can be lowered.
In this case, the taper shape in which the retaining portion is reduced in diameter may be set in two or more stages.

In the pipe joint according to the present invention, the seal portion is a protrusion protruding in a ring shape along the inside of the seal member, and the protruding direction of the protrusion is set obliquely toward the back side of the seal member. Preferably there is.
A seal portion provided inside the cylindrical seal member is pressed into contact with the outer peripheral portion of a tube material such as a copper tube due to a reduced diameter to form a seal portion by metal touch.
In this case, if the seal portion is formed in a ring shape so as to protrude over the entire inner periphery of the seal member, and if the protruding direction of the protrusion is inclined toward the back side, the following effects are obtained. It is done.
When the diameter of the end of the cylindrical seal member is reduced along the tapered portion, a diameter reducing force acts in a direction in which the protrusion slightly falls to the back side, but at that time, the protrusion slightly moves toward the back side. If it is slanted, the tip of the protrusion is likely to come into contact with the outer peripheral surface of the pipe material, and the tightening torque is also reduced.

The pipe joint according to the present invention can connect a pair of pipe materials by the reduced diameter of the cylindrical seal member disposed inside only by sliding the joint body part and the nut part to each other.
Therefore, the number of parts is smaller than that of the conventional pipe joint, and it is possible to reduce the material and the number of processing steps.

The half sectional view of the pipe joint concerning the present invention is shown. (A) shows a state before inserting the pipe material, (b) shows a state where the pipe material is inserted, and (c) shows a state where the pipe material is tightened and connected. The component structure of a pipe joint is shown. The external appearance perspective view of a sealing member is shown. The portion indicated by the alternate long and short dash line is expressed by notching so that the thickness shape can be understood. (A), (b) shows the state which inserts a pipe material from both sides inside a pipe joint, (c), (d) shows the state which fastens a joint main-body part and a nut part mutually. (A)-(c) shows the motion by which a seal member is diameter-reduced by the further fastening of a pipe joint. The external view of a stopper member is shown. The torque change by tightening of a pipe joint is shown, (a) shows the case where the taper of a joint main body side and a nut side is symmetrical, (b) shows the case where it is asymmetrical. (A) shows the structural example which fastens a joint main-body part and a nut part to a slide type, (b) shows the fragmentary sectional view of the state which butt-connected the pipe material. (A)-(c) shows explanatory drawing which fastens and connects the faced pipe materials. An example of a slide fastening tool is shown. The 2nd Example of a sealing member is shown. (A)-(c) shows the positional relationship of a slide part and an insertion part. (A)-(c) shows the procedure which butt-connects pipe materials. The component block diagram of a 2nd Example is shown.

Although the structural example of the pipe joint which concerns on this invention is demonstrated based on drawing below, this invention is not limited to this.
The first embodiment is a screw method, and the second embodiment is a slide method.

FIG. 2 shows a component configuration example of the pipe joint 10, and FIG. 3 shows an external view of the seal member 13.
FIG. 1 is a cross-sectional view showing the connection structure of the pipe materials 1 and 2.
The pipe joint 10 includes a cylindrical joint main body 11 having a male threaded portion 11a and a cylindrical nut portion 12 having a female threaded portion 12a that is screwed into the male threaded portion 11a. The member 13 is disposed.

The seal member 13 according to the present embodiment has a substantially cylindrical shape made of a brass material as shown in FIG.
The seal member 13 is symmetric as shown in FIG. 2, but is not necessarily symmetric.
As shown in FIGS. 1 and 2, the openings on both sides of the seal member 13 are retaining portions 13 b each having a notch 13 c partially formed.
The retaining portion 13b is a lock mechanism that has a pointed tooth shape with the tip facing inward and prevents the tubular materials 1 and 2 from slipping out due to the reduced diameter and preventing the tubular materials 1 and 2 from coming out.
A pair of left and right projections 13a projecting in a ring shape over the entire inner circumference is provided slightly behind the notch bottom of the notch 13c.
The protruding portion 13a is set so that the protruding direction is slightly rearward and oblique, and in this embodiment, θ shown in FIG. 1C is set in the range of 10 to 30 °.
Further, the tip of the protrusion 13a is in close contact with the outer peripheral surface of the pipe material, and the top is curved so that the sealing performance is enhanced.
Further, protrusions are also formed on the outer peripheral side of the seal member 13 so as to easily slide and reduce the diameter along the joint main body taper portion and the nut taper portion, and recesses 13d and 13e are formed on both sides of the inner protrusion 13a. It is an example.
Further, a groove-shaped stopper mounting portion 13f is formed at the inner central portion of the seal member 13, and a split ring-shaped stopper member 14 as shown in FIG. 6 is mounted.
When the pipe joint 10 is tightened in a state where the pipe materials 1 and 2 are abutted with each other, the stopper member 14 inserts the teeth of the retaining portion 13b, whose diameter is reduced, into the outer peripheral portion of the pipe materials 1 and 2, and the inner pipe (the back side). ) To absorb the amount of retraction.
Therefore, the stopper member 14 is preferably an elastic material.
In the present embodiment, it is made of resin and has a U-shaped cross section in which stopper portions 14b and 14b are erected inward from both sides of the bottom portion 14a so as to be easily deformed inward.

Next, the shape of the taper portion will be described with reference to FIGS. 2 and 4B.
The taper-shaped taper angle formed inside the joint body (left side in FIG. 4) 11 and the taper-shaped taper angle formed inside the nut part (right side in FIG. 4) 12 are set to be different. .
The taper on the joint main body 11 side is a first taper portion 11b in which the protrusion on the outer peripheral side of the seal protrusion 13a of the seal member 13 comes into sliding contact in order from the nut portion 12, and the horizontal tip in which the outer peripheral tip of the retaining portion 13b first comes into sliding contact. The second taper portion 11c has a gentle taper angle near the horizontal, the third taper portion 11d is slightly steep, and the fourth taper portion 11e is slightly gentler than the third taper portion 11d. 11f.
The taper formed on the inner side of the nut part 12 includes a first taper part 12b in which a protrusion on the outer peripheral side of the seal part 13a of the seal member is in sliding contact with the joint body part 11 side, a second taper part 12c having a horizontal or moderate taper angle, A third taper portion 12d having a steeper taper angle than the second taper portion 12c is provided, followed by a horizontal portion 12e.

The state in which the pipe materials 1 and 2 are inserted into the pipe joint 10 from both sides is shown in FIGS. 1B, 4A, and 4B.
In this embodiment, an O-ring 16 is provided inside the nut portion 12 and an O-ring 15 is provided inside the joint body 11 in order to prevent the inserted pipe material from being pulled out before being tightened.
The O-rings 15 and 16 have a temporary holding function that prevents the pipe material from coming out before the nut portion is tightened.
From this state, using a wrench or the like, the joint body 11 and the nut 12 are tightened as shown in FIG.
In addition, hexagonal portions 11g and 12f are provided on the outer shape portions of the joint main body portion 11 and the nut portion 12 so that a wrench or the like is caught.
The embodiment shown in FIGS. 4 and 5 is an example in which the nut side taper of the nut portion 12 is tightened first, and then the main body side taper of the joint main body portion 11 is tightened, but the present invention is simultaneously tightened. The torque of the entire tightening is reduced to avoid this, and either may be tightened first.
As shown in FIG. 4 (c), at the beginning of tightening, the third taper portion 12d of the nut side taper makes the taper angle gentler than the third taper portion 11d of the main body side taper so that the retaining portion 13b is tightened. ing.
The teeth of the nut-side retaining portion 13b loosen the pull-in tube material 1 that is difficult to outer peripheral surface of the tube material 1 while drawing it.
The nut side reduces the diameter of the seal member before the main body side, and the tightening torque on the nut side increases.
As the nut-side retaining portion 13b reaches the horizontal portion 12e, the nut-side seal portion 13a is tightened along the first tapered portion 12b as shown in FIG. 4 (d), and torque is generated. Since it is located at the horizontal portion 12e, the torque increase at the retaining portion 13b is small.
At the same time, as shown in FIG. 4 (d), the main body side retaining portion 13 a draws the recessed pipe material 2, which is difficult for the outer peripheral surface of the pipe material 2, by the third taper portion 11 d and the fourth taper portion 11 e of the main body side taper.
When the nut-side seal portion 13a reaches the second taper portion 12c that is nearly horizontal, the torque increase at the seal portion 13a is small, and the nut-side seal portion 13a is tightened along the main body side ale portion 13a or the main body side first taper portion 11b. Therefore, the tightening torque on the main body side increases.
Thereby, as shown in the graph of FIG.7 (b), a difference arises in the torque rise curve by the nut side and a main body side, and resultant force becomes small.
The horizontal portion has an effect of absorbing the tightening and variation of the nut, and the tube members 1 and 2 are pulled in by tightening the nut, but the stopper member 14 formed of a split ring absorbs this pulling amount.
The angle θ in the protruding direction of the seal portion 13a is adjusted so as to be perpendicular to the inclined surface of the first tapered portion 11b of the joint body portion 11, and the seal is made to be perpendicular to the inclined surface of the first tapered portion 12b of the nut portion 12. Since the angle θ in the protruding direction of the portion 13a is adjusted, the protruding portion 13a is likely to be in pressure contact with the outer peripheral surface of the pipe material.

Next, a structural example of a pipe joint in which the pipe body is butt-joined by sliding the joint body part and the nut part and reducing the diameter of the seal member will be described.
FIG. 8 shows a structural example of the pipe joint 100 in a state where the pipe materials 1 and 2 are butt-connected as the second embodiment.
FIG. 14 shows a configuration example of parts.
The main difference from the embodiment shown in FIG. 1 is that the joint body portion 111 and the nut portion 112 are slidably fastened, and the diameter of the seal member 13A is substantially the same.
However, in the case of screw fastening, it is desirable that the taper shapes of the joint main body portion and the nut portion are non-target, whereas in the case of slide fastening, both taper shapes may be targets.
In the case of slide fastening, the compression tool 20 is required as shown in the example of FIG. 10, but the torsional force to the pipe material generated when the threaded portion is tightened is eliminated.

As shown in FIGS. 8 and 9, the joint main body 111 has a cylindrical insertion portion 111a, and the nut portion 112 has a cylindrical slide portion 112a that slides the insertion portion 111a inward.
The slide portion 112a is formed integrally with the nut portion 112, and the weight is reduced.
The outer peripheral portion of the insertion portion 111a of the joint body 111 is formed with projections at two positions on the distal end side projection R ₁ and the base-side projection R _2.
On the other hand, a locking portion b is formed on the inner side of the slide portion 112a on the back side where the taper portion a is formed so that the protrusion is easily pushed in the back direction.
On the back side of the locking part b is an enlarged diameter part c whose inner diameter is larger than the inner diameter of the locking part.
Thus FIG. 9 (a), whether preceded connection tubing as shown in FIG. 12 (b), projections R ₁ interferes with the locking portion b, and from the nut portion of the joint main body falls off To prevent.
As shown in FIG. 9B, when the pipes 1 and 2 are butted and inserted from both sides and compressed so as to be sandwiched between the pressing portion 211 of the joint main body 111 and the pressing portion 212 of the nut portion 112 with a tool or the like. As shown in c), the seal portion 13a and the retaining portion 13b of the seal member 13A are reduced in diameter along the taper portion, and are fastened and connected in the same manner as in the first embodiment.
As described above, in the second embodiment, the diameter of the seal portion 13a and the retaining portion 13b of the seal member 13A is reduced along the tapered portion provided on the inner side simply by inserting the insertion portion 111a inside the slide portion 112a.
Therefore, the first embodiment requires the joint body and the nut to have a strength sufficient to withstand the twisting force when screwed with a pipe wrench or the like, whereas the second embodiment connects and holds the pipe material. Since the strength as much as possible is sufficient, the wall thickness can be designed to be thin, resulting in a small and lightweight pipe joint.
In the second embodiment, a ring-shaped protrusion 13g is integrally formed at the center of the inner peripheral portion of the seal member 13A, thereby forming a butt stopper for the tube material.
Further, as shown in FIG. 8 (b), stepped alignment portions 13h and 13i are formed in the central portion of the outer periphery of the seal member 13A so as to face each other, and the pressing portion 11i on the insertion portion 111a side and the contact portion on the slide portion 112a side. The alignment portion is sandwiched between the contact portion 12g.
As a result, it is possible to prevent the displacement of the seal member 13A at the insertion connecting portion, and the pressing force of the seal portion 13a and the retaining portion 13b is stabilized.
In a state in which the joint body portion 111 and the nut portion 112 is insertion engagement, protrusions R ₂ of root side provided on the outer peripheral portion is positioned in a recess d provided on the inner part of the sliding portion 112a of the joint body portion 111 , Engages with the retaining stopper e.
At this time, the front end portion f of the slide portion 112a hits the step portion 11h of the joint main body portion 111, and the fastening completion state can be visually confirmed.
Moreover, you may apply | coat a sealing agent along between this level | step-difference part 11h and the front-end | tip part f previously.

Although the structure of the slide fastening tool 20 is not limited as long as it can be relatively fastened to the nut portion 112 and the joint main body 111, an example is shown in FIG.
This is an example of a tool for performing the opening / closing operation of the support portion 21 and the handle portion 22 with the interval between the compression portions 23 and 24.
The pipe members 1 and 2 are connected by using the pipe joint 100 by sandwiching the pressing parts 211 and 212 of the pipe joint between the compression parts 23 and 24 and inserting the insertion part into the slide part.
The movement is shown in FIG.

DESCRIPTION OF SYMBOLS 10 Pipe joint 11 Joint main-body part 11a Male thread part 12 Nut part 12a Female thread part 13 Seal member 13a Seal part 13b Stopping part 13c Notch part 13f Stopper mounting part 14 Stopper member 100 Pipe joint 111 Joint main-body part 111a Insertion part 112 Nut part 112a Slide part

Claims (4)

A cylindrical joint body having an insertion part or a male thread part on the outer periphery, and a cylindrical nut part having a slide part for sliding the insertion part of the joint body part inward or a female thread part screwed into the male thread part; With
The joint body has a joint body taper that is expanded in diameter toward the nut side.
The nut part has a nut taper part whose diameter is expanded toward the joint body part on the inside,
It has a cylindrical seal member disposed across the nut taper portion from the joint body taper portion,
The seal member is a pair of pipes that are connected to the inside and are reduced in diameter by sliding reduction or tightening between the joint main body and the nut in a state where the pipes are inserted from the openings on both sides, and are respectively paired into the outer peripheral parts of the pipes on both sides. And a pair of seal portions that are pressed against and sealed to the outer peripheral portion, respectively.   The pipe joint according to claim 1, wherein a taper angle between the joint main body taper portion and the nut taper portion is non-target.   The seal part is a projecting part projecting in a ring shape along the inside of the seal member, and the projecting direction of the projecting part is set obliquely toward the back side of the seal member. The pipe joint according to 1 or 2.   The pipe joint according to any one of claims 1 to 3, wherein the taper portion with which the retaining portion is in sliding contact and the taper portion with which the seal portion is in sliding contact have two or more tapered shapes.