JP5302152B2 - Pipe joint - Google Patents

Description

  The present invention relates to a pipe joint suitable for connecting a hose having a coating in which a fiber reinforcing layer is sandwiched between an outer layer and an inner layer.

  A hose in which a fiber reinforcing layer is sandwiched between an outer layer and an inner layer so as to withstand a high internal pressure is known. This hose has a structure in which an outer layer tube in which a vinyl chloride resin or the like is extruded is provided on an inner layer tube in which a vinyl chloride resin or the like is extruded and sandwiched with a braided layer of high-tensile fiber. In such a hose, there is a problem that a high-pressure fluid flowing in the hose flows from a pinhole formed in the hose end portion or the inner layer tube into a gap between the outer layer tube and the inner layer tube, and the outer layer tube is ruptured. In order to solve the problem, a method of reliably sealing the end face of the hose has been developed (see Patent Document 1). In addition, a structure has been developed in which a through hole is provided in a nut that surrounds a pipe joint of a hose to release a high-pressure fluid that has flowed into a gap between the outer layer tube and the inner layer tube (see Patent Document 2).

JP 2006-258214 A JP-A-8-285143

The known prior art has the following problems to be solved.
As described in the above-mentioned patent document, the pipe joint has a structure in which the hose end is mechanically strongly tightened and fixed. If the structure that reliably prevents leakage of the internal fluid is used, it is not easy to release the high-pressure fluid that has flowed into the gap between the outer layer tube and the inner layer tube. On the other hand, it is not preferable to provide a through-hole or the like in the nut surrounding the pipe joint in order to maintain the airtightness and mechanical characteristics in design of the pipe joint. Furthermore, it is desired to develop a structure that can detect not only obstacles leading to rupture of the hose but also high-pressure fluid leaks early due to deterioration of seals at each part of the pipe joint.
In order to solve the above-described problems, an object of the present invention is to provide a pipe joint that can reliably release high-pressure fluid flowing into a gap between an outer layer tube and an inner layer tube through various paths.

The following configurations are means for solving the above-described problems.
<Configuration 1>
A hose 12 having an outer layer 14, an inner layer 16, and a fiber reinforcing layer 18 sandwiched between them is attached to the end of the hose 12, and an enlarged diameter portion 42 is inserted into the end of the hose 12. A connector 40 having an abutting portion 44 fitted into the bolt 24, an end portion 20 of the hose 12, and the connector 40, and a female screw portion 38 provided on the inner surface of the male screw portion 28 provided on the joint bolt 24. The joint nut 36 that presses the end portion 20 of the hose 12 against the enlarged diameter portion 42 of the connector 40, the male screw portion 28 that is screwed with the joint nut 36, and the fluid flowing through the hose 12. A through-hole 35 to be passed through, a small-diameter portion 30 that is coaxially continuous with the through-hole 35 and receives the abutting portion 44 of the connector 40, A large-diameter portion 32 for receiving the end portion 20 of the hose 12 into which a kuta is inserted, and in the groove provided on the outer periphery of the abutting portion 44 of the connector 40, the large-diameter portion 32 of the joint bolt 24 and the One or a plurality of O-rings (O-rings) 46 that seal between the abutting portions 44 of the connector 40 and formed so as to reach the large-diameter portion 32 from the small-diameter portion 30 of the joint bolt 24. A pipe joint characterized in that a relief groove 48 constituted by a concave portion at a location is provided.

<Configuration 2>
The pipe joint according to Configuration 1, wherein the relief groove 48 is a recess formed on the joint bolt 24 side that reaches the large diameter part 32 from the small diameter part 30 on the inner surface of the joint bolt 24. .

<Configuration 3>
The pipe joint according to Configuration 1 or 2, wherein the end face of the fiber reinforcing layer 18 of the hose 12 is opposed to the escape groove 48 at the portion of the large diameter portion 32.

<Configuration 4>
In the pipe joint according to any one of configurations 1 to 3, the abutting portion 44 of the connector 40 has a fiber reinforcement of the hose 12 facing the relief groove 48 at a portion facing the end surface of the fiber reinforcement layer 18. A pipe joint comprising a chamfered portion so as to increase an area of an end face of the layer 18.

<Configuration 5>
The pipe joint according to any one of configurations 1 to 4, wherein an insert ring 50 is provided between the abutting portion 44 of the connector 40 and the end portion of the hose 12, and the small diameter portion of the joint bolt 24 is provided in the insert ring 50. A pipe joint comprising the relief groove 48 formed of one or several concave portions formed so as to reach the large diameter portion 32 from 30.

<Configuration 6>
In the pipe joint according to Configuration 5, the insert ring is sandwiched between the joint bolt and the end of the hose to isolate the joint bolt and the end of the hose, and the joint nut A flange selected to have an outer diameter that does not collide with the female screw portion is provided, and a relief groove that reaches the female screw portion of the joint nut through the large diameter portion, stepped portion, and small diameter portion of the joint bolt is provided on the flange. And pipe fittings.

<Configuration 7>
The pipe joint according to Configuration 6, wherein a radial radial groove is provided on a surface of the flange in contact with the end of the hose.

<Effect of Configuration 1>
If a relief groove 48 is provided so as to reach the large diameter portion 32 from the small diameter portion 30 of the joint bolt 24, the high-pressure fluid is separated from the relief groove 48 between the female screw portion 38 of the joint nut 36 and the male screw portion 28 of the joint bolt 24. Pass through to the outside. Therefore, the leakage of the high pressure fluid can be detected at an early stage without rupturing the hose 12.
<Effect of Configuration 2>
A structure for releasing the high-pressure fluid by forming the relief groove 48 on the inner surface side of the joint bolt 24 can be realized.
<Effect of Configuration 3>
When the position of the end face of the fiber reinforcement layer 18 of the hose 12 is appropriately set, a path through which the high-pressure fluid is easily released can be secured.
<Effect of Configuration 4>
When the chamfered portion is provided in the abutting portion 44 of the connector 40, the area of the end surface of the fiber reinforcing layer 18 of the hose 12 facing the provided relief groove 48 is increased, so that the high-pressure fluid is easily released.
<Effect of Configuration 5>
Since it is not necessary to process the inner surface of the joint bolt 24, it can be applied to an existing pipe joint.
<Effect of Configuration 6>
Regardless of the state of the end of the hose, a gap is ensured from the notch of the insert ring to the male thread.
<Effect of Configuration 7>
It becomes easy to let a high-pressure fluid escape from the edge part of a fiber reinforcement layer.

(A) is the longitudinal cross-sectional view of the pipe joint 10 of Example 1, (b) is the principal part longitudinal cross-sectional view, (c) is a longitudinal cross-sectional view of a joint bolt part. It is a principal part external side view of the pipe joint 10 shown in FIG. It is explanatory drawing of the structure of the hose 12. FIG. FIGS. 2A to 2C are explanatory views of the principle of detecting a leak of high-pressure fluid, and FIGS. 1A to 1C are all longitudinal sectional views of the main part of the pipe joint 10 shown in FIG. (A) is the fragmentary longitudinal cross-sectional view of the pipe joint of Example 2, (b) is the principal part side view, (c) is a perspective view of an insert ring. (A) is the fragmentary longitudinal cross-sectional view of the pipe joint of Example 3, (b) is the principal part side view, (c) is a perspective view of an insert ring, (d) is a modified example perspective view of an insert ring. is there.

  Hereinafter, embodiments of the present invention will be described in detail for each example.

FIG. 1A is a longitudinal sectional view of a pipe joint 10 according to the first embodiment, FIG. 1B is a longitudinal sectional view of a main portion thereof, and FIG. 1C is a longitudinal sectional view of a joint bolt portion.
This pipe joint 10 is used to connect the hose 12 to the equipment. A connector 40 is attached to the end 20 of the hose 12 in advance. When the connector 40 is fitted into the joint bolt 24 and the joint nut 36 is put on, the fitting of the pipe joint to the hose 12 is completed. The hose 12 is made of synthetic rubber or resin, and has an outer layer 14, an inner layer 16, and a fiber reinforcing layer 18, as will be described later. The joint bolt 24, the joint nut 36, and the connector 40 are all made of hard plastic or metal.

Joint bolt 24, as shown in (c) of FIG. 1 includes a tool mounting part 26 for mounting a spanner or the like, the external thread portion 28 and the through-hole 35 for tightening covered with a joint nut 36. The through-hole 35 having a circular cross section is for allowing the fluid flowing through the hose 12 to pass therethrough. Further, the joint bolt 24 includes a small diameter portion 30 for receiving the connector 40 and a large diameter portion 32 for receiving the end portion 20 of the hose 12 so as to be coaxially continuous with the through hole 35. . The joint nut 36 includes a female screw portion 38 so as to be screwed over the male screw portion 28 of the joint bolt 24.

  The connector 40 is provided with an enlarged diameter portion 42 into which the end portion 20 of the hose 12 is fitted so as to expand its inner diameter. A sleeve 22 made of synthetic rubber or plastic is fitted into the hose 12. Both the sleeve 22 and the hose 12 are tightened by the joint nut 36 and pressed toward the diameter-expanded portion 42 of the connector 40. In this way, the end 20 of the hose 12 is firmly fixed inside the pipe joint 10.

  The abutting portion 44 of the connector 40 is fitted into the small diameter portion 30 of the joint bolt 24. A well-known O-ring 46 such as a synthetic rubber is fitted in a groove provided on the outer periphery of the abutting portion 44. This prevents the fluid flowing in the hose 12 from leaking from the through hole 35 side of the joint bolt 24 toward the outside of the connector 40.

  The part described so far is not different from the conventional pipe joint. In the conventional pipe joint, the entire end portion 20 of the hose 12 is in close contact with the inner surface of the large diameter portion 32 of the joint bolt 24 and the stepped portion of the abutting portion 44 of the connector 40. Further, the outer peripheral surface of the end portion 20 of the hose 12 is in close contact with the inner surface of the joint nut 36. In this state, for example, it is assumed that a pinhole is generated in the inner layer 16 of the hose 12 and the high-pressure fluid reaches the end 20 of the hose 12 through the fiber reinforcement layer 18. In this case, the pressure of the high-pressure fluid does not escape from the end face of the hose 12. Therefore, it has occurred that any part of the outer layer 14 of the hose 12 swells and the hose bursts.

In this embodiment, as shown in shown in FIG. 1 (b) and (c), it provided the escaping groove 48 is continuous from the small-diameter portion 30 of the hinge pin 24 until it reaches the large diameter portion 32. The relief groove 48 is formed at one location formed so as to reach the large diameter portion 32 into which the end portion 20 of the hose 12 is fitted through the step portion 34 from the small diameter portion 30 into which the abutting portion 44 of the connector 40 is fitted. Or it is comprised by several recessed parts. The abutting portion 44 of the connector 40 is provided with a chamfering process 45 that is inclined with respect to the cut surface of the end portion 20 at a portion where the end portion 20 of the hose 12 abuts and where the fiber reinforcing layer 18 is exposed. It is good to apply.

FIG. 2 is an external side view of the main part of the pipe joint 10 shown in FIG.
2 and 3, the overall configuration of the pipe joint 10 will be described, and then the function and effect of the relief groove 48 will be described with reference to FIG. 4. As shown in FIG. 2, the hose 12 is attached to the connector 40. An O-ring 46 (FIG. 1) is fitted into the groove of the abutting portion 44 of the connector 40. The abutting portion 44 of the connector 40 is fitted into the small diameter portion 30 of the joint bolt 24. Finally, the joint nut 36 is screwed so that the male thread portion 28 of the joint bolt 24 is tightened. After the hose 12 is connected, the tool mounting portion 26 is connected to a device (not shown).

FIG. 3 is an explanatory diagram of the structure of the hose 12.
As shown in (a) of FIG. 3, the hose 12 is fitted in the enlarged diameter portion 42 the outer periphery of the connector 40. Immediately before that, the sleeve 22 is fitted to the outer periphery of the hose 12. Hose 12, as shown in (b) of FIG. 3, it has an outer layer 14 and the fiber reinforced layer 18 from the outside in order and the inner layer 16 in the structure stack. The fiber reinforcement layer 18 is made by winding plastic or metal fibers in a net shape, and even if a high-pressure fluid is passed through the hose 12, the fiber reinforcement layer 18 can suppress swelling.

  In such a hose 12, when a pinhole is generated in the inner layer 16, the high-pressure fluid enters the portion of the fiber reinforcement layer 18 between the inner layer 16 and the outer layer 14. The fiber reinforcement layer 18 allows high-pressure fluid to freely travel in the longitudinal direction of the hose 12. Accordingly, when both ends of the hose 12 are completely sealed, the high-pressure fluid accumulated between the inner layer 16 and the outer layer 14 causes the outer layer 14 to swell and burst. If the outer layer 14 suddenly bursts at an unintended place, various problems occur and it takes time to recover. In this embodiment, when a high-pressure fluid flows between the outer layer 14 and the inner layer 16, the high-pressure fluid is released at the pipe joint. That is, it escapes through the escape groove 48 (FIG. 1) explained in FIG. 1 so that an abnormality can be detected at an early stage.

Figure 4 is a diagram of a leakage finding principle of high pressure fluid, in FIG. 4 (a) (c) is a principal part longitudinal cross sectional view of the pipe joint 10 both shown in FIG.
First, as shown in FIG. 4 (a), if generated pinholes in the inner layer 16 of any of the locations of the hose 12, it flows into the high pressure fluid as indicated by an arrow A in FIG. 4 to the fiber reinforced layer 18 think of. This high pressure fluid flows from the end 20 of the hose 12 into the escape groove 48. Furthermore, the high pressure fluid, as shown in chain line a thick one-dot of FIG. 4, exits to the outside through a gap between the female thread portion 38 and the male screw portion 28 of the hinge pin 24 of the relief groove 48 from the joint nut 36.

The place where metals hit each other is not airtight. Usually, both the joint bolt 24 and the joint nut 36 are made of metal. Since the metal surfaces are in contact between the male screw portion 28 and the female screw portion 38 in FIG. 4, the high-pressure fluid easily passes through this portion and leaks to the outside. If a portion sensitive to pressure is made along the relief groove 48, the high-pressure fluid leaks through the relief groove 48. When high-pressure fluid leaks to the outside, a certain trace remains in that part. Therefore, it can be understood that the high-pressure fluid leaks through the fiber reinforcement layer 18 for some reason if it is periodically inspected. Since the high-pressure fluid is allowed to escape through the escape groove 48 in this way, a high pressure that ruptures the outer layer 14 is not applied to the hose 12.

  FIG. 4B shows another function and effect of the escape groove 48. When the O-ring 46 deteriorates and loses elasticity, a high-pressure fluid leaks between the joint bolt 24 and the abutting portion 44. The high-pressure fluid passes through the relief groove 48 and passes between the female screw portion 38 and the male screw portion 28 to escape to the outside. Similarly, this can be easily found by periodic inspection. Further, when the O-ring 46 deteriorates in the pipe joint 10 attached to the opposite end of the hose 12, the high-pressure fluid may flow into the fiber reinforcement layer 18 of the hose 12. When the high-pressure fluid reaches the pipe joint, the high-pressure fluid can be released to the outside in the manner described with reference to FIG.

Incidentally, as shown in (c) of FIG. 4, even if the through hole 49 provided in the hinge pin 24, the same effect as the relief groove 48. The through-hole 49 allows the high-pressure fluid leaking to the boundary portion between the connector 40 and the joint bolt 24 to escape between the male screw portion 28 and the female screw portion 38. However, when the through-hole 49 is provided in the male screw portion 28, when the male nut 28 is screwed into the female screw portion 38 by rotating the joint nut 36, the edge of the through-hole 49 hits the screw groove and damages it. Sometimes. Compared to such a structure, the escape groove 48 as shown in FIG. 1 or FIG. 4 (a) can adjust the leakage amount freely by adjusting its width, depth and number, and has a very excellent function. I can say that.

5A and 5B are pipe joints according to the second embodiment, in which FIG. 5A is a partial longitudinal sectional view, FIG. 5B is a side view of the main part thereof, and FIG. 5C is a perspective view of an insert ring.
In the above example, by forming a concave groove on the inner surface of the joint bolt 24, the escape groove 48 along the large diameter portion 30, the step portion 34, and the small diameter portion 32 is provided. In this embodiment, the insert ring 50 is sandwiched between the small diameter portion 32 of the joint bolt 24 and the abutting portion 44 of the connector 40. A cutout is provided in the insert ring 50 to form an escape groove 52 along the large diameter portion 30, the step portion 34 and the small diameter portion 32. Insert ring 50, as shown in FIG. 5 (b), is interposed between the end of the abutting portion 44 and the hose 12 of the connector 40. Although an insert ring 50 is added, it is not necessary to process the inner surface of the joint bolt 24, so that it can be applied to an existing pipe joint.

6A and 6B are pipe joints of Example 3, in which FIG. 6A is a partial longitudinal sectional view thereof, FIG. 6B is a side view of the main part thereof, FIG. It is an example perspective view.
In the above embodiment, the notch 52 is provided in the insert ring 50. The high-pressure fluid that reaches the end of the hose 12 through the fiber reinforcing layer 18 of the hose 12 through the notch 52 is released to the outside. Further, the high pressure fluid leaking from between the joint bolt 24 and the abutting portion 44 is caused to escape to the outside due to deterioration of the O-ring 46 or the like. However, when various stresses are applied to the hose 12 and the outer layer 14 is strongly pressed against the end faces of the insert ring 50 and the joint bolt 24, the gap leading from the notch 52 of the insert ring 50 to the male screw portion 28 is sealed, and the insert There was a risk that the function of the ring 50 would be reduced. This can occur when the hose 12 is not securely fastened at any point other than this pipe joint.

  In this embodiment, in order to solve this point, the insert ring 50 is provided with a flange 53. The flange 53 is sandwiched between the joint bolt 24 and the end of the hose 12, isolates the joint bolt 24 and the end of the hose 12, and does not collide with the female screw portion 38 of the joint nut 36. Selected. Further, as shown in FIG. 6C, the insert ring 50 and the flange 53 are provided with a relief groove 52 that reaches the female thread portion 38 of the joint nut 36 through the large diameter portion 30, the step portion 34, and the small diameter portion 32. This ensures a gap from the notch 52 of the insert ring 50 to the male threaded portion 28 regardless of the state of the end of the hose 12. The high-pressure fluid that reaches the end portion of the hose 12 through the fiber reinforcement layer 18 of the hose 12 is transferred to the male screw portion 28 direction through the notch 52 of the flange 53.

  If an arbitrary number of radial radiating grooves 54 are provided on the surface of the flange 53 in contact with the end of the hose 12, high-pressure fluid can be easily released from the end of the fiber reinforcement layer 18. For example, when a pinhole is formed in the inner layer 16 of the hose 12 and a high-pressure fluid leaks into the fiber reinforcing layer 18, the mechanically weak outer layer 14 expands with the pressure. As a result, the fiber reinforced layer 18 and the outer layer 14 are peeled off, and an accident that the outer layer 14 bursts at an unexpected place occurs. If the high-pressure fluid leaking into the fiber reinforcement layer 18 is allowed to escape from the pipe joint, an increase in pressure inside the fiber reinforcement layer 18 can be suppressed. In addition, it is possible to notice abnormalities in the hose 12 with certainty during regular inspections. Therefore, measures such as appropriate repairs can be taken before the hose 12 is ruptured.

DESCRIPTION OF SYMBOLS 10 Pipe joint 12 Hose 14 Outer layer 16 Inner layer 18 Fiber reinforcement layer 20 End part 22 Sleeve 24 Joint bolt 26 Tool mounting part 28 Male thread part 30 Large diameter part 32 Small diameter part 34 Step part 35 Through hole 36 Joint nut 38 Female thread part 40 Connector 42 Widened portion 44 Abutting portion 46 O-ring 48 Escape groove 49 Through hole 50 Insert ring 52 Notch 53 Flange 54 Radiation groove

Claims (3)

It is attached to the end of a hose (12) having an outer layer (14), an inner layer (16), and a fiber reinforcing layer (18) sandwiched between them,
A connector (40) having an abutting portion (44) to be inserted into the joint bolt (24) by inserting a diameter-expanded portion (42) at an end of the hose (12);
The end portion (20) of the hose (12) and the connector (40) are surrounded, and a female screw portion (38) provided on the inner surface is screwed with a male screw portion (28) provided on the joint bolt (24). A joint nut (36) for pressing the end (20) of the hose (12) against the enlarged diameter portion (42) of the connector (40),
A male threaded portion (28) threadedly engaged with the joint nut (36), a through hole (35) for allowing fluid flowing through the hose (12) to pass therethrough, and coaxially continuous with the through hole (35); A small diameter portion 30 for receiving the abutting portion (44) of (40) and a large diameter portion 32 for receiving the end portion (20) of the hose (12) into which the connector is inserted,
In the groove provided on the outer periphery of the abutting portion (44) of the connector (40), the gap between the large diameter portion 32 of the joint bolt (24) and the abutting portion (44) of the connector (40) is sealed. O-ring (46) to stop,
An escape groove (48) formed by one or several concave portions formed so as to reach the large diameter portion 32 from the small diameter portion 30 of the joint bolt (24) is provided,
An insert ring (50) sandwiched between the abutting portion (44) of the connector (40) and the end of the hose (12) is provided, and the insert ring (50) is connected to the small diameter portion 30 of the joint bolt (24). A pipe joint comprising the relief groove (48) formed of one or several concave portions formed so as to reach the large diameter portion 32 . The pipe joint according to claim 1 ,
The insert ring is sandwiched between the joint bolt and the end of the hose so as to isolate the joint bolt and the end of the hose and select an outer diameter that does not collide with the female thread of the joint nut. A pipe joint characterized in that a flange is provided, and a relief groove reaching the female threaded portion of the joint nut through the large diameter portion, the step portion, and the small diameter portion of the joint bolt is provided on the flange. The pipe joint according to claim 2 ,
A pipe joint, wherein a radial groove is provided on a surface of the flange in contact with the end of the hose.

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