JP4724765B2 - Pipe fitting - Google Patents

Description

  The present invention relates to a pipe joint.

As a conventional pipe joint, a plurality of the above-mentioned small protrusions protruding from the inner peripheral surface of the retainer are screwed into the tapered female threaded portion of the joint body by screwing the male threaded portion of the retainer holding a plurality of abacus-shaped small disks. A structure in which a disk is bitten into the outer peripheral surface of a pipe so that the pipe is not pulled out in the axial direction is known (for example, see Patent Document 1).

However, this conventional pipe joint has a structure in which a small disk is spiraled and gradually deepened around the outer peripheral surface of the pipe, so a very large tightening is required to screw the retainer into the joint body. Power is required and work efficiency is poor.

Japanese Patent No. 312385

The problem to be solved is that a large force is required for tightening at the time of connection work and a large number of rotation work is required.

Therefore, a pipe joint according to the present invention is a pipe joint including a joint body, an outer fitting member attached to the joint body, and a holder cylinder inserted into the outer fitting member, The holder cylinder is provided with a plurality of elongated holding holes in a direction parallel to the direction in which the pipe is inserted, and an elongated truncated cone-shaped locking cone is held in each of the holding holes. The trapezoidal locking cone is held in the holding hole so that the large-diameter end surface faces the inside of the joint, and the outer fitting member is formed with a tapered inner surface, and the outer fitting member is externally attached to the holder cylinder. fit is allowed to be prevented from escaping the locking cone in the radial outside direction by the tapered inner surface, the outer peripheral edge of the large diameter end faces of the locking cone, a state bite that has bite into the pipe outer peripheral surface, the pipe Is connected so as not to be pulled out.

According to the pipe joint of the present invention, a pipe can be strongly connected easily and quickly. In particular,
The pipe can be easily and reliably connected only by inserting the pipe, and even if a strong pulling force in the direction of the joint is applied to the pipe, there is no risk of disconnection, and the connection can be made securely and firmly. In addition, pipes can be connected with a small rotational torque and with a small number of cap nuts, and there is no risk of disconnection even if a strong pulling force in the direction of the joint is applied to the pipe. Can be connected.

It is a cross-sectional front view which shows the use condition of the 1st Embodiment of this invention. It is a figure for demonstrating the principal part, Comprising: (A) shows the perspective view of a latching cone, (B) is explanatory drawing which shows "elongate shape". It is a perspective view of the assembly unit of a locking cone and a holder cylinder. It is a side view of the assembly unit of a locking cone and a holder cylinder. It is a sectional front view at the time of inserting a pipe into a pipe joint. It is a sectional front view at the time of inserting completely until a pipe contacts the stepped part of a joint main part. It is a principal part expanded sectional front view which shows the state which force acted on the direction pulled out from a pipe joint to a pipe, and the taper inner surface of an external fitting member and the latching cone contacted. It is a principal part enlarged front view which shows the state which made the inner peripheral end edge of the large diameter end surface of a latching cone bite into the outer peripheral surface of a pipe. It is a cross-sectional front view which shows the use condition of 2nd Embodiment. It is a cross-sectional front view which shows a pipe uninserted state. It is a sectional front view at the time of inserting completely until a pipe contacts the stepped part of a joint main part. FIG. 6 is a cross-sectional front view showing a state in which the cap nut is screwed into the joint body and the tapered inner surface of the cap nut and the locking cone are in point contact. Furthermore, it is a cross-sectional front view showing a state where the cap nut is screwed into the joint body and the lock cone is raised until the axis of the locking cone becomes substantially parallel to the joint axis. FIG. 14 is an enlarged cross-sectional front view of a main part of FIG.

FIG. 1 shows a use state of the first embodiment of the present invention. This pipe joint includes a metal (for example, steel or brass) joint body 1, a metal (for example, brass) outer fitting member 2, a plastic holder cylinder 3 inserted in the outer fitting member 2, and a plastic spring. A pipe joint having a material 23 is used by inserting a metal (for example, metal such as aluminum, copper, SUS) pipe P on the inner peripheral surface 4 side of the holder cylinder 3. The fluid flowing in the pipe P may be either liquid such as water or oil, or gas (gas). A case where the outer fitting member 2 is a cap nut 24 screwed to the joint body 1 is shown.

As shown in FIGS. 1 to 4, the holder cylinder 3 having an elongated holding hole 5 extending in the direction of the joint axis L, and the holding hole 5 are held so that the large-diameter end face 9 faces the inside of the joint. An elongated frustoconical locking cone 6 is provided. An outer fitting member 2 having a tapered inner surface 7 is fitted on the holder cylinder 3. As shown in FIG. 2B, the “elongated shape” means a longitudinal length dimension a (viewed from the radial direction).
And the horizontal dimension b is a relationship of a × 1.2 ≦ b. In the case of b <a × 1.2, an inclination angle β of the tapered inner surface 7 of the cap nut 24 (FIGS. 7 and 8) is used to cause the locking cone 6 (described later) to bite into the pipe outer peripheral surface P ₁ to a predetermined depth. And the inclination angle of the outer peripheral surface 8 of the locking cone 6 (an angle half the virtual vertex angle θ in FIGS. 7 and 8) needs to be increased. The force pressed by the taper inner surface 7 in the radial inward direction becomes excessively small.

  A spring material (spring) 23 for elastically urging the holder cylinder 3 outward from the joint is attached. The pipe P is inserted, and it is configured so as to be engaged in a biting manner by a pulling operation with a small dimension.

The locking cone 6 is loosely held in the holding hole 5 of the holder cylinder 3. In particular,
When the locking cone 6 is not bitten (see FIGS. 5 to 7), the shaft center 15 of the locking cone 6 is reduced in the outward diameter (approaching to the joint axis L as it goes in the joint outward direction). In the case of tilting and shifting to the biting state (see FIGS. 1 and 8), the retaining cone 5 is held so as to swing until the shaft center 15 of the locking cone 6 becomes substantially parallel to the joint shaft center L. Has been.

  As shown in FIGS. 7 and 8, there is a relationship of β≈ (1/2) θ between the inclination angle β of the tapered inner surface 7 and the virtual vertex angle θ of the locking cone 6. In the present invention, the “virtual apex angle” refers to an apex angle of an isosceles triangle that is a cross section when a virtual cone including the bottom surface and side surface of the truncated cone is cut along a plane including the center point and the apex of the bottom surface. Define that.

When there is no relation of β≈ (1/2) θ between the inclination angle β of the taper inner surface 7 and the virtual vertex angle θ of the locking cone 6, the radial inner end 14 of the outer peripheral edge 10 becomes the pipe outer peripheral surface P ₁ . It is not possible to eat almost in the radial direction. Specifically, the virtual vertex angle θ of the locking cone 6 is set to 18 ° ≦ θ ≦ 35 °. The virtual apex angle θ is desirably set to 20 ° ≦ θ ≦ 30 °. When θ <18 °, the length dimension of the entire pipe joint in the direction of the joint axis L is too long. When 35 ° <θ, the biting force in the direction of arrow A in FIG. 8 is too small (for the same magnitude of pipe pulling force).

Next, a procedure for connecting the pipe P to the pipe joint of the first embodiment (a procedure for inserting the pipe P into the pipe joint and preventing it from coming off) will be described.
First, as shown in FIG. 5, the pipe P is inserted into a pipe joint in which the joint body 1 and the outer fitting member 2 are completely assembled. The locking cone 6 is waiting for the pipe P in a free state. At this time, the minimum inner diameter portion of the plurality of locking cones 6—the small diameter end portion 26 in FIG. 5—is between the virtual inscribed circle diameter φd and the outer diameter φD of the pipe P. , Φd ≦ φD is established.

Next, as shown in FIG. 6, the pipe P is completely inserted until it contacts the stepped portion 25 of the joint body 1. When the pipe P is inserted into the pipe joint, since the outer peripheral surface 8 of the locking cone 6 is along the pipe outer peripheral surface P ₁ (in line contact), the pipe P can be smoothly inserted into the pipe joint. In particular, even when the pipe P is soft, the pipe P is not damaged. In the non-bite-in state, the shaft center 15 of the locking cone 6 is inclined outwardly reduced in diameter (that is, the shaft center 15 is inclined so as to approach the joint axis L as it goes outward from the joint. )

Thereafter, as shown in FIG. 7, when a force (pulling force F) is applied to the pipe P in the direction of pulling out from the pipe joint, the locking cone 6 is centered on the radial inner end 14 of the outer peripheral edge 10 of the large-diameter end face 9. Furthermore, by using the lever, the pipe outer peripheral surface P ₁ is shifted to the biting state shown in FIGS. 1 and 8 (from the non-biting state shown in FIG. 7). When shifting to the biting state , the locking cone 6 swings up (rises) by an angle α until the shaft center 15 of the locking cone 6 becomes substantially parallel to the joint shaft center L.

There is a relationship of α≈β between the raising angle α and the inclination angle β of the taper inner surface 7. When there is no relationship of α≈β between the raising angle α and the inclination angle β, the radial inner end 14 of the outer peripheral edge 10 cannot be bitten into the pipe outer peripheral surface P ₁ substantially in the radial direction.

Specifically, the spring material 23 (see FIG. 6) elastically biases the holder cylinder 3 outward from the joint, and the spring material 23 initially attaches the locking cone 6 to the pipe outer peripheral surface P ₁ of the pipe P. The biting is caused, and the locking cone 6 is locked into the pipe P in a biting manner (in a certain manner) by the small movement of the pipe P. That is, the pipe P is inserted and the outer peripheral edge 10 of the large-diameter end surface 9 of the locking cone 6 escapes radially outward at the tapered inner surface 7 of the outer fitting member 2 by a small-sized drawing operation. While being suppressed, it is engaged with the pipe outer peripheral surface P ₁ in a bite manner. Note that the spring member 23 can move the locking cone 6 along the axis L in the direction of the axis L by a minute dimension so that the tolerance variation of the outer diameter φD of the pipe P can be accommodated.

In the above biting state , the axial center 15 of the locking cone 6 is substantially parallel to the joint axis L, and the large-diameter end surface 9 is formed as an orthogonal plane orthogonal to the joint axis L. the radial inner end 14 of which engages with the pipe outer peripheral surface P _1.

  9 to 14 show a second embodiment. This pipe joint is configured to be engaged in a biting manner by inserting the pipe P and screwing the cap nut 24 into the joint body 1. Other configurations are the same as those of the first embodiment.

Next, a procedure for connecting the pipe P to the pipe joint according to the second embodiment (a procedure for inserting the pipe P into the pipe joint and preventing it from coming off) will be described.
First, until the pipe P is brought into contact with the stepped portion 25 of the joint body 1 as shown in FIG. 11, the pipe joint in which the joint body 1 and the cap nut 24 are slightly screwed together as shown in FIG. Insert completely.

Next, when the cap nut 24 is screwed into the joint body 1, the locking cone 6 comes into contact with the tapered inner surface 7, and the outer peripheral edge 10 of the large-diameter end surface 9 is radial as shown in FIGS. 12 and 13. It swings around the inner end 14 by this utilization and rises by the raising angle α until the shaft center 15 of the locking cone 6 becomes substantially parallel to the joint shaft center L. Then, as shown in FIG. 14, the initial bite depth dimension ε is engaged with the pipe outer peripheral surface P _{1 so as} to bite. The initial biting depth dimension ε is about 2/100 mm in the radial direction. That is, the cap nut 24 can be tightened (rotated) very lightly and manually. Thereafter, when the cap nut 24 is further screwed with a work tool (giving a strong rotational torque), the radial inner end 14 of the locking cone 6 is securely attached to the pipe outer peripheral surface P ₁ as shown in FIGS. It can be bitten and locked.

The present invention can be modified in design. For example, the outer fitting member 2 may be a short cylindrical body fixed or attached to the joint body 1. Further, the type of the spring member 23 may be a star washer, a disc spring, a coil spring, or the like. Further, only one of the open ends 22 of the linear joint body 1 may have the configuration of the present invention. Further, the joint body 1 may be a trident, a quadrant or the like. Further, the holding hole 5 of the holder cylinder 3 may be three or more, for example, three, four, or the like.

Further, as shown only in FIG. 9, a small hole 12 that communicates the inner side and the outer side in the radial direction may be provided on the inner side of the joint body 1 so as to close the small hole 12 with an O-ring 13. When the cap nut 24 is manually tightened, the cap nut 24 cannot be tightened to the position where the O-ring 13 is pressed, and when the cap nut 24 is completely tightened with a work tool (see FIG. 9), The O-ring 13 is configured to be screwed to a position where the O-ring 13 is pressed (from the outer peripheral surface side). When the water pressure inspection is performed, water leakage occurs when the work tool is not completely tightened, so that it is possible to detect incomplete tightening.

As described above, the present invention includes the elongated truncated cone-shaped locking cone 6, and the outer peripheral edge 10 of the large-diameter end surface 9 of the locking cone 6 is engaged with the pipe outer peripheral surface P _{1 so as} to bite. The pipe P can be connected easily and reliably simply by inserting the pipe P, and there is no risk of disconnection even if a strong pulling force in the joint direction is applied to the pipe P, and the connection can be made securely and firmly. it can. In addition, the pipe P can be connected with a small rotational torque and with a small rotation of the cap nut 24, and even if a strong pulling force in the direction of the joint is applied to the pipe P, there is no risk of disconnection. And it can connect firmly.

In addition, a holder cylinder 3 having an elongated holding hole 5 extending in the direction of the joint axis L, and a large-diameter end surface 9
An elongated frustoconical locking cone 6 held in the holding hole 5 so that the
An outer fitting member 2 having a tapered inner surface 7 is fitted on the holder cylinder 3 to prevent the locking cone 6 from escaping radially outward, and the outer peripheral edge 10 of the large-diameter end surface 9 of the locking cone 6 is piped. Since the outer peripheral surface P ₁ is engaged in a bite manner, the pipe P can be connected easily and reliably by simply inserting the pipe P, and the pipe P can be pulled out even if a strong pulling force in the joint direction is applied. There is no fear and the connection can be made securely and firmly. In addition, the pipe P can be connected with a small rotational torque and with a small amount of rotation of the external fitting member 2, and there is no possibility that the pipe P will come out even if a strong pulling force in the joint direction is applied to the pipe P. It is possible to connect securely and firmly.

Further, in the biting state , the shaft center 15 of the locking cone 6 is substantially parallel to the joint axis L, and the large diameter end surface 9 is an orthogonal plane orthogonal to the joint axis L, so that the large diameter end surface is obtained. Since the radial inner end 14 of the outer peripheral edge 10 is locked to the pipe outer peripheral surface P ₁ , the radial inner end 14 of the outer peripheral edge 10 of the large-diameter end surface 9 is substantially radially directed to the pipe outer peripheral surface P _1. Can be bitten.
Further, since the outer fitting member 2 is a cap nut 24 screwed to the joint body 1, if the cap nut 24 is completely tightened with a work tool, the subsequent pulling of the pipe P does not occur at all. is there.

Further, a spring member 23 is provided for elastically urging the holder cylinder 3 outwardly from the joint. Further, the pipe P is inserted, and the holder cylinder 3 is configured to be engaged in a biting manner by a small-sized drawing operation. Therefore, the outer peripheral edge 10 of the large-diameter end surface 9 of the locking cone 6 is securely connected to the outer peripheral surface P ₁ of the locking cone 6 only by an easy operation of inserting the pipe P and pulling out a small dimension, although it has a simple configuration. Can be engaged in a biting manner.
Further, since the pipe P is inserted and the cap nut 24 is screwed into the joint body 1 so as to be engaged in a bite shape, the large size of the locking cone 6 can be ensured only by rotating the cap nut 24. The outer peripheral edge 10 of the radial end surface 9 can be engaged with the pipe outer peripheral surface P ₁ in a bite manner.

Further, the locking cone 6 is loosely held in the holding hole 5 of the holder cylindrical body 3, and when not bitten, the axis 15 of the locking cone 6 is inclined outwardly and shifts to the biting state . At this time, since the holding hole 5 is held so as to swing until the axis 15 of the locking cone 6 becomes substantially parallel to the joint axis L, it is possible to prevent the outer fitting member 2 from being damaged. it can.
Further, since there is a relation β≈ (1/2) θ between the inclination angle β of the taper inner surface 7 and the virtual vertex angle θ of the locking cone 6, the outer periphery of the large-diameter end surface 9 of the locking cone 6. substantially radial inner end 14 of the edge 10 on the pipe outer peripheral surface P ₁ can bite into the radial direction.

DESCRIPTION OF SYMBOLS 1 Joint body 2 Outer fitting member 3 Holder cylinder 5 Holding hole 6 Locking cone 7 Tapered inner surface 9 Large diameter end surface
10 Outer edge
14 Radial inner edge
15 axis
23 Spring material
24 Cap nut L Joint axis P Pipe P ₁ Pipe outer peripheral surface β Tilt angle θ Virtual vertex angle

Claims (1)

A pipe joint provided with a joint body (1), an outer fitting member (2) attached to the joint body (1), and a holder cylinder (3) inserted into the outer fitting member (2) The holder cylinder (3) is provided with a plurality of elongated holding holes (5) extending in a direction parallel to the direction in which the pipe (P) is inserted, thereby forming an elongated truncated cone-shaped locking cone. (6) is held in each holding hole (5), and the holding hole (5) is such that the large-diameter end surface (9) of the elongated truncated cone-shaped locking cone (6) faces the inside of the joint. The outer fitting member (2) is formed with a tapered inner surface (7), and the outer fitting member (2) is fitted onto the holder cylinder (3) to form the tapered inner surface (7). and prevent the escape the locking cone (6) in the radial outside direction by the outer peripheral edge (10 of the large diameter end faces of the locking cone (6) (9) And a state bite that has bite into the pipe outer peripheral surface (P _1), the pipe joint, characterized in that connecting to the pipe (P) is not pulled out.

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