JP3828524B2 - Pipe fitting - Google Patents

Description

The present invention relates to a pipe joint.

  As a pipe joint known conventionally, there is a pipe joint which connects a pipe to be connected by causing a protrusion or the like to bite into an outer peripheral surface of an end of the pipe to be connected. For example, as shown in the vertical cross-sectional view of the main part of FIG. 7 and the cross-sectional view of the main part in FIG. Some include a push ring 43 screwed into the portion 46 and a C-shaped ring-shaped stopper 44 that is pressed by the tapered inner surface 42 of the push ring 43 and is reduced in diameter. And the substantially circumferential protrusion 45 which bites into the outer peripheral surface of the to-be-connected pipe P with diameter reduction is formed in the internal peripheral surface of the retainer 44 (for example, refer patent document 1).

However, in this conventional pipe joint, when the connected pipe P is made of a resin such as polyethylene, the protrusion 45 can be bitten into the pipe wall (outer peripheral surface), but when the connected pipe P is made of metal, When the protrusion 45 cannot be bitten and an axial pulling force acts on the connected pipe P, the protrusion 45 slides and easily comes out of the joint body 41.
That is, since the protrusion 45 contacts the entire circumference of the outer peripheral surface of the connected pipe P, the biting force to the pipe wall is dispersed in the circumferential direction, and the biting depth becomes shallow as shown in FIGS. There is a problem that the retaining action of the connected pipe P is small.

Further, since the protrusion 45 contacts the connected pipe P over the entire circumference, a high dimensional accuracy is required for the roundness of the retainer 44, making it difficult to manufacture. Therefore, a large tightening torque (force) of the push wheel 43 is required.
Furthermore, there is a problem that the biting force of the protrusion 45 into the connected pipe P is small and the retaining action is small for a large tightening torque.
Further, due to a small axial misalignment (eccentricity, inclination) between the joint body 41 and the connected pipe P during the connection work, the protrusion 45 is in a single contact state with respect to the tube wall and is not partially bitten. There is a problem that the retaining force cannot be obtained all around.
JP-A-8-93975

  The problem to be solved is that, although a large tightening torque is required at the time of connection, the retaining effect is small. In addition, high dimensional accuracy is required for the components of the joint, which makes it very difficult to manufacture.

The present invention includes a joint main body having a tapered tube portion whose outer peripheral surface is enlarged in diameter from the opening end side and a male screw tube portion connected to the taper tube portion, and having a connected pipe as an insertion shape, A small disk continuous body for retaining pipes that is held in a small window portion formed at a plurality of circumferential positions of the tapered tube portion in a non-connected state so as to partially protrude from the outer peripheral surface, and a screw threaded to the male screw tube portion. A female threaded cylinder part, and the female threaded cylindrical part abuts against the small disk continuous body as the female threaded cylindrical part is screwed into the male threaded cylindrical part and presses the small disk continuous body against the connected pipe. A pipe fitting having a taper inner peripheral surface that bites in, and the inclination angle of the taper inner peripheral surface and the inclination angle of the outer peripheral surface of the tapered cylindrical portion of the joint body are set to be the same It is, the small disc connecting bodies are integrally a plurality of small disks is provided continuously in the axial direction Is a, the small disc connecting bodies is the disc diameter by the Hare said small disk along the inclined shape of the tapered tubular portion of the joint body, an opening end side or order from then following the increase in the tapered tube portion , the aforementioned tightening cap and the small disc connecting bodies is the same hardness, and is a hardness greater than the the connected pipe, the small disc connecting bodies through the resin material to the small window section It will be retained.

The pipe joint of the present invention can exert a large retaining force against the connected pipe with a small tightening torque (force) by the tightening cap even if the connected pipe is made of metal. In other words, the small-disc continuous body can be crushed into a concave shape locally (concentrated) from a plurality of locations in the circumferential direction to the tube wall (outer peripheral surface), and the connected pipe can be prevented from being pulled out. Very large.
In addition, the pipe can be connected only by rotating and tightening the tightening cap, so that the work at the installation location can be simplified and speeded up.
Since the number of parts is small and the structure is simple, the manufacturing cost can be reduced.

  FIG. 1 is a longitudinal sectional view showing an embodiment of a pipe joint according to the present invention, and FIG. 2 is a sectional view of an essential part thereof. The left half of FIG. 1 is a connection completed state in which the connected pipe P is fixed to the pipe joint, and the right half is inserted before the connected pipe P is inserted into the joint main body 1 and the fastening cap 3 is tightened to the joint main body 1. Connection state (pre-connection state).

  The pipe joint includes a cylindrical joint body 1 having a connected pipe P as an insertion shape, a pipe retaining small disk continuous body 2 held in a wall portion of the joint body 1, and a male formed on the joint body 1. A tightening cap 3 having a female screw cylinder portion 8 screwed into the screw cylinder portion 5.

As shown in FIGS. 1 and 2, the joint body 1 is a cylindrical member, and the outer peripheral surface 6 has a tapered cylindrical portion 4 whose diameter increases from the open end (tip) 10 side toward the base end portion 13 side. And a male threaded cylinder part 5 connected to the tapered cylinder part 4.
That is, the male threaded cylinder part 5 is continuous from the large diameter part of the tapered cylinder part 4 to the base end part 13 side so as to be coaxial with the tapered cylinder part 4, and the inner peripheral surface of the tapered cylinder part 4 7 and the inner peripheral surface 14 of the male screw cylinder portion 5 are continuous with the same inner diameter, and constitute one cylindrical hole-shaped insertion hole 15. Then, the connected pipe P is inserted into the straight insertion hole 15.

The inner part of the insertion hole 15 of the joint body 1 has a reduced diameter stepped shape, and the end surface of the connected pipe P is brought into contact with the stepped surface 16 so that the connected pipe P is positioned.
As shown in FIG. 1, the joint body 1 has a male screw cylinder portion 5 and a tapered cylinder portion 4 on both sides from the central cylinder portion 17, and connected pipes P and P are connected on both sides.

  In addition, an O-ring groove 23 is formed on the inner peripheral surface of the insertion hole 15, and the O-ring 24 seals (maintains airtightness) with the outer peripheral surface of the connected pipe P inserted into the insertion hole 15. )is doing. The pipe joint may be an elbow-type or T-shaped joint other than shown.

The pipe-disconnecting small disk connecting body 2 is held in small window portions 11 formed at a plurality of locations in the circumferential direction of the tapered cylindrical portion 4 of the joint body 1, and is not connected in the right half of FIG. In the pre-connection state, the taper cylinder portion 4 is held so that a part thereof protrudes radially outward from the outer peripheral surface 6.
In addition, in the inner peripheral surface 7 side of the taper cylinder part 4, in the unconnected state (state before connection), the small disk continuous body 2 does not protrude greatly from the inner peripheral surface 7, and the small disk continuous body 2 (of the Some) are exposed.
That is, when the connected pipe P is inserted into the insertion hole 15 of the joint body 1, the connected pipe P is prevented from being caught on the small disk connecting body 2.

FIG. 3 is a side view of the main part of the joint body 1 and shows the male threaded cylinder part 5 and the tapered cylinder part 4. The small window portion 11 is a through-hole formed in a substantially intermediate position in the axial direction on the tube wall of the tapered tube portion 4, and is formed at a plurality of circumferential intervals at equal intervals.
In FIG. 3, the small disk continuous body 2 (small window portion 11) is disposed at four positions with a phase of 90 °, but the small disk continuous body 2 may be at least two or more. The number of circumferential arrangements may be increased appropriately in accordance with the required pulling force, pipe diameter, and the like.

FIG. 4 is an enlarged side view of the small disk continuous body 2. The small disk continuous body 2 is formed by integrating a plurality of small disks 12 in the axial direction. 2 to 3 pearls, and in FIG. 4, three small disks 12 are provided.
Thus, since the small disk continuous body 2 is composed of a plurality of small disks 12, the small disk continuous body 2 is pulled out even if a pulling force is applied to the connected pipe P after being connected to the pipe joint. There is no falling in the direction.
Moreover, the shape of one small disk 12 is a abacus bead shape in which a circumferential top portion 18 is formed at the center in the axial center direction, and truncated cone portions 19, 19 are formed toward both sides thereof.

FIG. 5 is an enlarged side view showing another embodiment of the small disk connecting body 2, and this connecting body 2 has a rounded top part 18 and a connecting part with the adjacent small disk 12. The shape is
4 and 5, the shaft centers of the small disks 12 are arranged on the same straight line so as to be integrated, and the direction of the shaft center of the small disk connecting body 2 is the same as the generatrix direction of the tapered tube portion 4. It is held so as to be in a substantially matching direction.

Further, the small disk connecting body 2 sequentially (in stages) increases the disk diameter d (d ₁ , d ₂ , d ₃ ) of each small disk 12 so as to follow the inclined shape of the tapered cylindrical portion 4 of the joint body 1. I am letting.
That is, the thickness (tube thickness) of the tube wall of the tapered tube portion 4 of the joint body 1 increases from the opening end 10 (tip) side toward the base end portion 13 side. Accordingly, the disk diameter (diameter) d of the small disk 12 is set so as to increase sequentially from the opening end 10 side toward the base end portion 13 side.

Specifically, the small disk continuous body 2 held (embedded) in the small window portion 11 penetrating the middle portion of the tube wall of the tapered tube portion 4 is arranged on the opening end 10 side in accordance with the tube thickness. smaller than the disk diameter d ₃ of the small disk 12c disposed a disc diameter d ₁ of the small disk 12a disposed in the proximal portion 13 side, the open end of the disk diameter d ₂ of the small disc 12b of the intermediate portion It is set to be larger than the disk diameter d ₁ of the small disk 12a disposed on the 10 side and smaller than the disk diameter d ₃ of the small disk 12c disposed on the base end 13 side.
That is, d ₁ <d ₂ <d ₃ is set.

  Therefore, the hole shape of the small window portion 11 for holding the small disk continuous body 2 is trapezoidal so as to correspond to the shape of the small disk continuous body 2 as shown in FIG. The circumferential top portion 18 is brought into contact with or in contact with the inclined circumferential wall surface of the small window portion 11, and both axial end surfaces of the small disk connecting body 2 approach the parallel circumferential wall surface of the small window portion 11. Or in contact.

The small disk continuous body 2 is held in the small window portion 11 via a resin material. That is, a thermoplastic resin melted in the small window portion 11 is put (filled), and the small disk connecting body 2 is held in the small window portion 11 by curing of the resin. That is, resin is used as a temporary adhesive.
According to this, the small disk continuous body 2 is not dropped from the small window portion 11 of the joint body 1 during transportation and mounting work, and the small disk continuous body is brought into contact with the fastening cap 3. When the small disk continuous body 2 is pushed inward in the radial direction by the tightening cap 3 (which will be described later), the small disk continuous body 2 is resisted against the holding force by the resin. Can be shifted radially inward within the small window portion 11.

As shown in FIGS. 1 and 2, the tightening cap 3 includes a female screw cylinder portion 8 that is screwed into the male screw cylinder portion 5 of the joint body 1, and a tapered inner peripheral surface 9 that is provided continuously with the female screw cylinder portion 8. And a fastening cylinder portion 20 having the same.
That is, the large diameter portion of the tapered inner peripheral surface 9 of the tightening cylindrical portion 20 is continuously provided on one side of the female screw of the female screw cylindrical portion 8, and the tapered inner peripheral surface 9 is reduced in diameter toward the end portion. .
The outer peripheral surface of the tightening cap 3 is formed with a plurality of axial grooves for preventing slipping, or has a square shape (hexagon or octagon) so that it can be gripped with a tool such as a spanner. It makes work easier.

Further, the inclination angle (gradient) of the taper inner peripheral surface 9 and the inclination angle (gradient) of the outer peripheral surface 6 of the tapered cylindrical portion 4 of the joint body 1 are set to be the same, and the female screw of the fastening cap 3 When the cylindrical portion 8 is screwed into the male threaded cylindrical portion 5 of the joint body 1 and the connection is completed, the tapered inner peripheral surface 9 and the outer peripheral surface 6 of the tapered cylindrical portion 4 of the joint body 1 are in a face-to-face contact state. be able to.
Accordingly, as the female screw cylinder portion 8 is screwed into the male screw cylinder portion 5, the tapered inner peripheral surface 9 of the tightening cap 3 comes into contact with the protruding small disk connecting body 2 and the small disk connecting body 2 2 is pushed into the connected pipe P on the inner diameter side.

Furthermore, the end portion of the tightening cylinder portion 20 of the tightening cap 3 has a flange portion 21 that is bent so as to be further reduced in diameter radially inward from the small diameter portion of the tapered inner peripheral surface 9.
When the fastening cap 3 is screwed into the joint body 1 and the connection is completed, the open end 10 of the joint body 1 comes into contact with the inner wall surface of the flange 21.

  As a result, even if the pulling force in the axial direction acts on the pipe P to be connected and the small disk continuous body 2 biting into the pipe wall (outer peripheral surface) is taken and pulled out, the flange portion 21 of the tightening cap 3 is It is possible to prevent the small disk connecting body 2 from moving in the drawing direction via the tip end portion 4a (see FIG. 2) of the tapered tube portion 4, and to maintain a firm connection state.

Next, the material of the joint body 1, the small disk connecting body 2, and the fastening cap 3 will be described. The joint body 1 is made of metal or hard plastic.
The small disk continuous body 2 is made of metal and is made of a material having higher hardness than the connected pipe P. The fastening cap 3 is preferably made of a metal having substantially the same hardness as that of the small disk connecting body 2, but if desired, most of the part is made of plastic, and a tapered metal short tube is provided at the part of the tapered inner peripheral surface 9. The inner peripheral surface 9 of the tapered metal short tube may be configured to be in contact with the small disk continuous body 2 by being embedded.
Further, the material of the connected pipe P is an iron pipe, a steel pipe, a stainless steel pipe, a copper pipe, or the like, or plastic in some cases, and the fluid flowing in the connected pipe P includes a liquid and a gas (gas). And as a specific use of the pipe joint of this invention, there exists a connection for the copper pipe for air-conditioner gas, for example.

Next, the state of the small disk continuous body 2 and the connected pipe P when the tightening cap 3 is rotated and screwed into the joint body 1 will be described.
When the tightening cap 3 is rotated and the female screw cylinder portion 8 is screwed into the male screw cylinder portion 5 of the joint main body 1, the tapered inner peripheral surface 9 of the tightening cap 3 is expanded in diameter to the tapered cylinder portion 4 of the joint main body 1. The taper inner peripheral surface 9 comes into contact with the small disk continuous body 2 by approaching the outer peripheral surface 6.

  Further, when the tightening cap 3 is rotated and screwed in the axial direction, a force in the radial center direction pressing the small disk connecting body 2 against the connected pipe P is generated by the taper action of the taper inner peripheral surface 9. That is, the tightening torque of the tightening cap 3 acts as a biting force on the pipe wall (outer peripheral surface) of the connected pipe P of the small disk connecting body 2, and the small disk connecting body 2 is the tube wall of the connected pipe P. Bite into.

Then, as shown in the cross-sectional view of the main part of the pipe joint in the connection completed state in FIG. 6, the biting depressions 22 are formed at a plurality of circumferential locations of the pipe P to be connected. Further, as shown in FIG. 2, a plurality of the recessed portions 22 are continuously formed in the axial direction by the small disk connecting body 2 including the plurality of small disks 12.
At the time of this biting, the small disk continuous body 2 is slightly rotated around the axis of the small disk continuous body 2 due to friction with the tapered inner peripheral surface 9 of the rotating tightening cap 3 (rotation). However, it does not rotate (revolve) with respect to the connected pipe P.

In the pipe joint of the present invention, the diameter of the insertion hole 15 and the small disk connecting body 2 are small so that the biting depth a of the small disk connecting body 2 to the connected pipe P is 0.3 mm to 1.5 mm. The diameter is set by adjusting the disk diameter d of the disk 12 and the tube thickness of the tapered tube 4.
When the bite depth a is less than the lower limit value, the bite force is insufficient and the retaining action is reduced. Further, when the biting depth a exceeds the upper limit value, a large tightening torque by the tightening cap 3 is required, and a complete tightening state may not be obtained.
Further, preferably, the biting depth a is 0.5 mm to 0.7 mm, whereby a firm connection completion state can be obtained and connection work can be performed with a small force.

  As described above, according to the present invention, the outer peripheral surface 6 has the tapered cylindrical portion 4 whose diameter increases from the opening end 10 side, and the male threaded cylindrical portion 5 connected to the tapered cylindrical portion 4. A pipe main body 1 in which the pipe P is inserted, and a pipe stopper that is held in a small window portion 11 formed at a plurality of locations in the circumferential direction of the tapered cylindrical portion 4 so as to partially protrude from the outer peripheral surface 6 without being connected. Small disk continuous body 2 and female threaded cylinder part 8 screwed into male threaded cylinder part 5, and small disk continuous body as screwed into female threaded cylinder part 5 of female threaded cylinder part 8 2 and a tightening cap 3 having a taper inner peripheral surface 9 that presses and bites the small disk continuous body 2 against the connected pipe P, so that the small disk continuous body 2 is connected to the connected pipe P. The tube wall (outer peripheral surface) can be crushed into a concave shape locally (concentrated) from multiple locations in the circumferential direction. The removal effect of the pipe P is extremely large.

Furthermore, the connection work only needs to rotate the tightening cap 3, and no special tool or welding work is required, the connection work can be easily performed, and the work can be completed quickly at the installation location.
In addition, since the number of parts is small and the configuration is very simple, the manufacturing cost can be reduced and an inexpensive pipe joint can be obtained.

Further, the small disk continuous body 2 is formed integrally by connecting a plurality of small disks 12 in the axial direction, and the small disk continuous body 2 has an inclined shape of the tapered cylindrical portion 4 of the joint body 1. The disk diameter d of the small disk 12 is sequentially increased from the opening end 10 side of the tapered tube portion 4 so that the tapered inner peripheral surface 9 of the clamping cap 3 is brought into contact with the entire small disk continuous body 2. Can do.
Therefore, the taper action of the taper inner peripheral surface 9 generates a force for pressing the small disk continuous body 2 toward the center in the radial direction. That is, the tightening torque of the tightening cap 3 is caused to act as a biting force on the pipe wall (outer peripheral surface) of the connected pipe P of the small disk connecting body 2, so that the small disk connecting body 2 is connected to the pipe wall of the connected pipe P. Can be squeezed firmly into.

  In addition, since the tightening cap 3 and the small disk continuous body 2 have the same hardness and higher hardness than the connected pipe P, the small disk continuous body 2 is connected to the outer side tightening cap. 3, the small disk continuous body 2 can be securely bited into the connected pipe P on the inner side (inner diameter side).

  Since the small disk continuous body 2 is held in the small window portion 11 via a resin material, the small disk continuous body 2 is connected to the small window portion 11 of the joint body 1 when the pipe joint is transported or attached. When the small disk continuous body 2 is pushed in by the tightening cap 3, the small disk continuous body 2 is radially inward in the small window portion 11 against the holding force of the resin. It is possible to shift to the connected pipe P.

It is a longitudinal cross-sectional view which shows one Embodiment of the pipe joint which concerns on this invention. It is principal part sectional drawing of a pipe joint. It is a principal part side view of a coupling main body. It is a side view of a small disk connection body. It is a side view which shows other embodiment of a small disk continuous connection body. It is a principal part cross-sectional view of the pipe joint in a connection completion state. It is a principal part longitudinal cross-sectional view of the conventional pipe joint. It is a principal part cross-sectional view of the conventional pipe joint in a connection completion state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Joint body 2 Small disk continuous body 3 Fastening cap 4 Tapered cylinder part 5 Male thread cylinder part 6 Outer peripheral surface 8 Female thread cylinder part 9 Taper inner peripheral surface
10 Open end
11 Small window
12 Small disk d Disk diameter P Connected pipe

Claims (1)

The outer peripheral surface (6) has a tapered cylindrical part (4) whose diameter is increased from the opening end (10) side and a male threaded cylindrical part (5) connected to the tapered cylindrical part (4). The joint body (1) having the pipe (P) as an insertion shape, and the outer peripheral surface (6) in an unconnected state within the small window portions (11) formed at a plurality of locations in the circumferential direction of the tapered tube portion (4). A small pipe continuous body for pipe removal (2) held so that a part protrudes from the pipe, and a female screw cylinder (8) screwed into the male screw cylinder (5), and the female screw cylinder As the portion (8) is screwed into the male threaded cylindrical portion (5), the small disk continuous body (2) comes into contact with the connected pipe (P). A fastening cap (3) having a taper inner peripheral surface (9) for pressing and biting ;
The inclination angle of the tapered inner peripheral surface (9) and the inclination angle of the outer peripheral surface (6) of the tapered cylindrical portion (4) of the joint body (1) are set to be the same.
The small disk continuous body (2) is formed by integrating a plurality of small disks (12) in the axial direction, and the small disk continuous body (2) is the joint body (1). The diameter (d) of the small disk (12) is sequentially increased from the opening end (10) side of the tapered cylinder part (4) so as to follow the inclined shape of the tapered cylinder part (4).
The tightening cap (3) and the small disk connecting body (2) have the same hardness and higher hardness than the connected pipe (P),
The said small disk continuous connection body (2) is hold | maintained through the resin material in the said small window part (11) .

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