JP7024346B2 - Cramp nut for pipe fittings - Google Patents

Description

The present invention relates to a crimping nut for a pipe joint.

Examples of pipe fittings include hose fittings.
The hose joint fitting is generally configured to include a joint body and a crimping nut for a pipe joint.
The hose fitting is connected to the fitting on the equipment side provided in the equipment via a crimping nut for a pipe joint.
The crimping nut for pipe fittings is a nut part, a cylinder part protruding from the nut part and having an inner peripheral portion formed on a cylindrical surface, and an inner surface surface protruding inward in the radial direction of the cylinder part at the tip of the cylinder part and standing up from the cylindrical surface. It is provided with an annular protrusion having a.
Then, the protrusions are crimped inward in the radial direction of the protrusions on the concave groove consisting of the side surfaces and the bottom surface of the joint body facing each other so that the protrusions can rotate in the concave groove and the protrusions face each other in the axial direction of the joint body. A pipe joint is configured by being movably connected to the extent that it can be moved between the side surfaces (see Patent Document 1).
On the other hand, in the conventional crimping nut for pipe joints, the inner surface of the annular protrusion is orthogonal to the cylindrical surface of the crimping cylinder before the protrusion is crimped.

Japanese Unexamined Patent Publication No. 2010-266004

Therefore, by crimping the protrusion, the inner surface of the protrusion becomes an inclined surface that is displaced toward the cylinder as it goes from the cylindrical surface to the inside in the radial direction.
As a result, when the female screw of the crimping nut for the pipe joint is screwed into the male screw of the fitting on the equipment side, the inner surface of the crimping nut for the pipe joint is in line contact with the side surface of the concave groove of the joint body instead of the surface contact. Alternatively, since point contact occurs, the posture of the joint body with respect to the crimping nut for the pipe joint is not stable, rattling is likely to occur, and the crimping nut for the pipe joint cannot be rotated with a stable torque.
Therefore, it is disadvantageous in smoothly connecting the hose joint fitting and the device side joint fitting, and is disadvantageous in improving the work efficiency.
In addition, when the pressure of the fluid flowing through the hose, hose joint fitting, and equipment side joint fitting is applied in the direction away from the equipment side joint fitting, the inner surface of the crimping nut for pipe joint and the concave groove of the joint body. The side surface of the hose is not in surface contact but in line contact or point contact, and the force is concentrated on the contacted part and applied to the inner side surface and side surface, which is disadvantageous in improving the durability of the hose joint fitting. It is also disadvantageous in improving the pressure resistance performance of hose fittings.
The present invention has been devised in view of the above circumstances, and an object thereof is to improve work efficiency when connecting a pipe joint and a fitting on the device side, and to improve durability and pressure resistance of the pipe joint. It is an object of the present invention to provide a crimping nut for a pipe fitting which is advantageous for planning.

In order to achieve the above object, the invention according to claim 1 includes a nut portion, a tubular portion that protrudes from the nut portion in a cylindrical shape coaxially with the nut portion, and has an inner peripheral portion formed by a cylindrical surface. The tip of the tubular portion is provided with an annular protrusion that protrudes inward in the radial direction of the tubular portion and has an inner surface that rises from the cylindrical surface, and the protrusion is rotatable in the concave groove of the joint body and the concave groove . A crimping nut for a pipe joint, which is crimped by a crimping device so as to be movable in the axial direction of the joint body to form a pipe joint. It is characterized in that it is formed of an inclined surface that is displaced in a direction away from the tubular portion from the cylindrical surface toward the inside in the radial direction so that the side surface and the side surface of the concave groove facing the inner side surface are parallel to each other. do.
The invention according to claim 2 is characterized in that the angle θ formed by the inclined surface with respect to the plane orthogonal to the axial direction of the cylindrical surface is in the range of 3 degrees to 12 degrees.

According to the invention according to claim 1, in the crimping nut for a pipe joint, the inner side surface and the side surface of the concave groove facing the inner side surface are parallel to each other in a state where the protrusion is crimped. When the tightening nut is screwed into the fitting on the equipment side, the inner side surface of the fitting nut for the pipe joint and the side surface of the concave groove of the joint body are close to each other while maintaining a parallel state, and the fitting nut for the pipe joint The inner surface and the side surface of the large diameter portion of the joint body come into surface contact with each other.
Therefore, the posture of the joint body with respect to the crimping nut for the pipe joint does not rattle, and a stable coupling state between the pipe joint and the equipment side joint fitting can be easily obtained, and the connection between the pipe joint and the equipment side joint fitting can be easily obtained. It is advantageous in improving the work efficiency of the operation.
When the pressure of the fluid flowing through the fitting body and the fitting on the device side is applied in the direction of separating the fitting body from the fitting on the device side, the force is applied to the fitting for the pipe joint from the side surface of the concave groove of the fitting body. It acts on the inner surface of the nut.
In this case, since the side surface of the concave groove of the joint body and the inner surface of the crimping nut for the pipe joint are in surface contact, the force is distributed over the entire surface contacted inner surface and side surface, so that the durability of the pipe joint is durable. It is also advantageous in improving the pressure resistance performance of the pipe joint.
According to the second aspect of the present invention, crimping the protruding portion of the crimping nut for a pipe joint is advantageous in positioning the inner side surface on a plane orthogonal to the axis of the cylinder portion.

It is a side view which cut the part of the hose joint fitting to which the crimping nut for a pipe joint which concerns on embodiment is attached. It is a side view which broke a part of the hose joint fitting to which the crimping nut for a pipe joint which concerns on embodiment is attached, and the equipment side joint fitting connected to it. It is a side view which a part of the crimping nut for a pipe fitting which concerns on embodiment is broken. It is a side view which broke a part of the hose joint metal fittings before the crimping nut for a pipe fitting which concerns on embodiment is attached by crimping. It is an enlarged sectional view which shows the state which the crimping nut for a pipe fitting which concerns on embodiment is crimped to a joint body. It is a side view which broke a part of the conventional crimping nut for a pipe joint. It is an enlarged sectional view which shows the state which the conventional crimping nut for a pipe fitting is crimped to the joint body. FIG. 3 is an enlarged cross-sectional view showing a state in which a conventional crimping nut for a pipe joint is crimped to a joint body and connected to a fitting on the device side. It is an enlarged cross-sectional view which shows that the posture of a joint body is not stable with respect to a crimping nut for a pipe joint in a state where a conventional crimping nut for a pipe joint is crimped to a joint body and is connected to a fitting on a device side. ..

Next, the crimping nut for a pipe joint according to the embodiment of the present invention will be described with reference to the drawings.
In this embodiment, a case where the pipe joint is a hose joint fitting will be described.
As shown in FIG. 1, the hose joint fitting 10 is connected to the end of the hose 12 and is appropriately detachably connected to the device to supply the fluid flowing in the hose 12 to the device or to appropriately supply the device. The fluid is discharged from the hose 12 by the hose 12.
The hose joint fitting 10 includes a joint main body 14 and a crimping nut 16 for a pipe joint.
The joint body 14 includes a nipple 18 and a socket 20.
As shown in FIG. 2, the hose joint fitting 10 is connected to the equipment side joint fitting 46 provided in the equipment 44 via a pipe joint crimping nut 16.

As shown in FIG. 1, the nipple 18 is made of metal and has a tubular shape, and is configured by coaxially arranging a large diameter portion 22, a small diameter portion 24, a tool hook portion 26, and a nipple side tubular portion 28. A hole 1802 is formed through the center of the hole 1802.
The large-diameter portion 22 is a portion that is detachably attached to and detached from the device-side joint fitting 46 and has a cylindrical shape.
The small diameter portion 24 is formed at the end of the large diameter portion 22 with an outer diameter smaller than that of the large diameter portion 22 along the circumferential direction.
The tool hooking portion 26 is provided at a position opposite to the large diameter portion 22 with the small diameter portion 24 interposed therebetween, and is provided in a hexagonal shape.
A recessed groove 30 for mounting a crimping nut by means of a side surface 2202 in which the large diameter portion 22 faces the tool hook portion 26, a bottom surface 2402 formed of an outer peripheral surface of the small diameter portion 24, and a side surface 2602 of the tool hook portion 26 facing the side surface 2202. Is configured.
The side surfaces 2202 and 2602 are located on a plane orthogonal to the axis of the nipple 18, and the outer peripheral surface (bottom surface 2402) of the small diameter portion 24 is formed by a cylindrical surface centered on the axis of the nipple 18.
The crimping nut 16 for a pipe joint, which will be described later, can rotate by crimping through the crimping nut mounting concave groove 30, and moves in the axial direction within the range in which the protrusion 42 can move in the crimping nut mounting concave groove 30. Can be installed.
A concave groove 32 for attaching the socket 20 is formed in the portion of the nipple 18 adjacent to the tool hook portion 26.
The nipple-side tubular portion 28 is provided adjacent to the concave groove 32 and is a portion to be inserted into the inner peripheral surface 1202 of the hose 12, and the uneven portion 2802 is provided on the outer peripheral surface thereof.

The socket 20 is made of metal and has a cylindrical shape.
The socket 20 is configured such that a tubular mounting portion 34 and a socket-side tubular portion 36 are arranged side by side on the same axis.
The mounting portion 34 is attached by being crimped to the concave groove 32 of the nipple 18, whereby the nipple 18 and the socket 20 are coupled.
An annular space S is provided between the socket-side tubular portion 36 and the nipple-side tubular portion 28 in a state where the mounting portion 34 is attached to the concave groove 32.

Then, with the hose 12 inserted in the annular space S between the outer peripheral portion of the nipple 18 and the inner peripheral portion of the socket 20, a crimping range along the axial direction of the socket 20 is performed by a crimping device (not shown). Inside, the socket 20 is crimped inward in the radial direction thereof, and the hose joint fitting 10 is in close contact with the entire circumference of the outer peripheral surface 2804 of the nipple side tubular portion 28 with the entire circumference of the inner peripheral surface 1202 of the hose 12 in close contact with the hose. It is attached to 12.
As shown in FIG. 2, the hose fitting 10 to which the fitting nut 16 for a pipe joint is assembled has a female screw 3802 of the fitting nut 16 for a pipe joint and a male screw of the fitting 46 on the device side of the device 44. It is connected by binding to 4602.

Next, the crimping nut 16 for a pipe joint will be described.
As shown in FIG. 3, the crimping nut 16 for a pipe joint includes a nut portion 38, a tubular portion 40, and a protrusion 42.
The nut portion 38 is configured such that a female screw 3802 is formed on the inner peripheral surface thereof and a hexagonal shape is formed on the outer peripheral surface thereof.
The tubular portion 40 projects from one end in the axial direction of the nut portion 38, and the inner peripheral portion of the tubular portion 40 is formed by a cylindrical surface 4002.
The protrusion 42 exhibits an annular shape that protrudes inward in the radial direction at the tip of the cylinder 40, and has an inner side surface 4202 that stands up from the cylindrical surface 4002.
As shown in FIG. 1, in a state where the protrusion 42 is crimped, the length L of the protrusion 42 along the axial direction of the pipe fitting crimp nut 16 is the recessed groove 30 for mounting the crimp nut. It is formed with dimensions smaller than the width W.
The inner side surface 4202 is formed of an inclined surface that is displaced in a direction away from the tubular portion 40 from the cylindrical surface 4002 toward the inside in the radial direction.
The angle θ formed by the inclined surface with respect to the plane P orthogonal to the axial direction of the cylindrical surface 4002 varies depending on the inner diameter of the protrusion 42 and the amount of crimping inward in the radial direction of the protrusion 42, but from about 3 degrees. In the range of 12 degrees, when the protrusion 42 is crimped, the inner side surface 4202 of the pipe joint crimping nut 16 and the side surface 2202 of the large diameter portion 22 of the joint body 14 are easily made substantially parallel. It becomes advantageous in.
That is, on the inner side surface 4202, the protrusion 42 is crimped inward in the radial direction of the tubular portion 40 on the small diameter portion 24 of the joint body 14, and the protrusion 42 can rotate into the recessed groove 30 for attaching the crimp nut of the joint body 14. It is configured to be substantially located on a plane orthogonal to the axis of the tubular portion 40 in a state of being coupled to the cylinder portion 40.

Next, attachment of the crimping nut 16 for a pipe joint to the recessed groove 30 for mounting the crimping nut of the joint main body 14 will be described.
As shown in FIG. 4, the inside of the protrusion 42 and the tubular portion 40 of the pipe fitting crimping nut 16 in a state where the axis of the pipe fitting crimping nut 16 and the axis of the joint body 14 are aligned with each other. The recessed groove 30 for mounting the crimping nut and the large diameter portion 22 of the joint body 14 are inserted into the recessed groove 30 for mounting the crimping nut. Position it so that it is located inside.
After positioning, the protrusion 42 of the pipe fitting crimping nut 16 is crimped inward in the radial direction by a crimping device (not shown).
As a result, as shown in FIGS. 1 and 5, the tubular portion 40 of the crimping nut 16 for the pipe joint is displaced inward in the radial direction together with the protrusion 42, and the protrusion 42 is accommodated in the recessed groove 30 for mounting the crimp nut. Will be done.
In this state, a gap is secured between the inner peripheral surface 4204 of the protrusion 42 and the bottom surface 2402 of the recessed groove 30 for mounting the crimping nut, whereby the crimping nut 16 for the pipe joint can rotate on the bottom surface 2402. It becomes a state.
Further, the protrusion 42 is in a state of being movable in the axial direction of the joint body 14 between the side surfaces 2202 and 2602 of the recessed groove 30 for attaching the crimping nut.

Here, on the inner side surface 4202 formed of an inclined surface that is displaced in a direction away from the cylinder portion 40 from the cylindrical surface 4002 toward the inside in the radial direction, the cylinder portion 40 and the protrusion 42 are nuts due to the crimping of the protrusion 42. The end of the tubular portion 40 on the portion 38 side is used as a fulcrum and is inclined toward the axial center of the pipe fitting crimping nut 16. As a result, the inner side surface 4202 is on a plane orthogonal to the axial center of the tubular portion 40. Almost located.
As a result, the inner side surface 4202 of the pipe fitting crimping nut 16 and the side surface 2202 of the large diameter portion 22 of the joint body 14 are substantially parallel to each other. The side surface 2202 of the large diameter portion 22 of 14 is in a state where surface contact is possible.
Next, as shown in FIGS. 2 and 5, by connecting the female screw 3802 of the pipe fitting crimping nut 16 to the male screw 4602 of the equipment side joint fitting 46, the equipment side joint fitting located at the end of the male screw 4602. The end surface 4606 of the tubular portion 4604 of 46 and the end surface 2204 of the large diameter portion 22 of the hose joint fitting 10 are pressure-welded over the entire area thereof and are liquid-tightly coupled.

According to the present embodiment, the inner side surface 4202 of the crimping nut 16 for a pipe joint is formed of an inclined surface that is displaced in a direction away from the tubular portion 40 from the cylindrical surface 4002 toward the inside in the radial direction. By crimping the protrusion 42 of the fitting nut 16, the angle of the inner side surface 4202 with respect to the axis of the pipe fitting crimping nut 16 changes, and the inner side surface 4202 is the shaft of the pipe fitting crimping nut 16. It is located on a plane orthogonal to the center.
Therefore, when the female screw 3802 of the pipe fitting crimping nut 16 is screwed into the male screw 4602 of the equipment side joint fitting 46, the inner side surface 4202 of the pipe fitting crimping nut 16 and the side surface of the large diameter portion 22 of the joint body 14 2202 is close to each other while maintaining a parallel state, and the inner side surface 4202 of the pipe fitting crimping nut 16 and the side surface 2202 of the large diameter portion 22 of the joint body 14 come into surface contact with each other.
As a result, the posture of the large diameter portion 22 of the joint body 14 with respect to the crimping nut 16 for the pipe joint does not rattle, and a stable coupling state between the hose joint fitting 10 and the equipment side joint fitting 46 can be easily obtained. This is advantageous in improving the work efficiency of the connection operation between the hose joint fitting 10 and the device side joint fitting 46.

Further, when the pressure of the fluid flowing through the hose 12, the hose joint fitting 10, and the device side joint fitting 46 is applied in the direction of separating the joint body 14 from the device side joint fitting 46, the force is applied to the large diameter of the joint body 14. The side surface 2202 of the portion 22 acts on the inner side surface 4202 of the crimping nut 16 for a pipe joint.
In this case, since the side surface 2202 of the large diameter portion 22 of the joint body 14 and the inner side surface 4202 of the crimping nut 16 for the pipe joint are in surface contact, the force is distributed over the entire area of the inner side surface 4202 and the side surface 2202 in which the force is in surface contact. Therefore, it is advantageous for improving the durability of the hose joint fitting 10, and also for improving the withstand voltage performance of the hose joint fitting 10.
Further, since the inner side surface 4202 and the side surface 2202 of the large diameter portion 22 of the joint body 14 come into surface contact with each other, the torque when tightening the pipe fitting crimping nut 16 to the joint body 14 is stable, and the crimping nut rotates. The angle is reduced.
This facilitates the work of attaching the hose joint fitting 10 to the device-side joint fitting 46 in a narrow place where it is difficult for tools to enter.
Further, since the torque when the crimping nut 16 for the pipe joint is tightened to the joint main body 14 is stable, the slip of the crimping nut is reduced.
This enables a surface treatment called a top coat that covers the surfaces of the crimping nut 16 for a pipe joint and the joint main body 14 with a synthetic resin coating, which is advantageous in improving the durability of the hose joint fitting 10.

Next, a case where a conventional crimping nut 16'for a pipe joint is used as a comparative example will be described.
In the following comparative examples, the same parts and members as those in the embodiment are designated by the same reference numerals as those in the embodiment.
As shown in FIG. 6, the conventional crimping nut 16'for a pipe joint is substantially on a plane P whose inner side surface 4202 is orthogonal to the axis of the tubular portion 40 in a state before the protrusion 42 is crimped. It is configured to be located.
Insert the recessed groove 30 for mounting the crimping nut and the large diameter portion 22 of the joint body 14 into the protrusion 42 and the tubular portion 40 of the crimping nut 16'for the pipe joint, and insert the crimping nut 16'for the pipe joint and the joint. Positioning is performed so that the protrusion 42 is located in the recessed groove 30 for mounting the crimping nut in the axial direction of the main body 14, and the protrusion 42 of the crimping nut 16'for the pipe joint is radially oriented by a known crimping device. Tighten inward.
As a result, as shown in FIG. 7, the tubular portion 40 of the crimping nut 16'for the pipe joint is displaced inward in the radial direction together with the protrusion 42, and the protrusion 42 is accommodated in the recessed groove 30 for mounting the crimp nut. The protrusion 42 is in a state of being movable in the axial direction of the joint body 14 between the side surfaces 2202 and 2602 of the recessed groove 30 for attaching the crimping nut.

Here, in the inner side surface 4202 of the protrusion 42, the cylinder portion 40 and the protrusion 42 are connected to each other by crimping the protrusion 42, with the end portion of the cylinder 40 on the nut portion 38 side as a fulcrum as a fulcrum. It is inclined toward the axis of 16', and as a result, the inner side surface 4202 becomes an inclined surface that is displaced toward the tubular portion 40 from the cylindrical surface 4002 toward the inside in the radial direction.
As a result, as shown in FIG. 8, the inner side surface 4202 of the pipe fitting crimping nut 16'is inclined with respect to the side surface 2202 of the large diameter portion 22 of the joint body 14, and therefore, the pipe fitting crimping nut 16 The inner peripheral end of the inner side surface 4202 of ′ is in a state where line contact or point contact is possible with the side surface 2202 of the large diameter portion 22 of the joint body 14.
Therefore, when the female screw 3802 of the pipe fitting crimping nut 16'is screwed into the male screw 4602 of the equipment side joint fitting 46, the inner side surface 4202 of the pipe fitting crimping nut 16'is the large diameter portion of the joint body 14. Since surface contact cannot be made with the side surface 2202 of 22, as shown by the dotted line in FIG. 9, the posture of the large diameter portion 22 of the joint body 14 with respect to the crimping nut 16'for the pipe joint is not stable, and it becomes easy to rattle and is stable. The crimping nut 16'for the pipe joint cannot be rotated by the applied torque, which is disadvantageous in smoothly connecting the hose joint fitting 10 and the equipment side fitting 46, and is disadvantageous in improving work efficiency. ..

Further, when the pressure of the fluid flowing through the hose 12, the hose joint fitting 10, and the device side joint fitting 46 is applied in the direction of separating the joint body 14 from the device side joint fitting 46, the force is applied to the large diameter of the joint body 14. It acts from the side surface 2202 of the portion 22 to the inner side surface 4202 of the crimping nut 16'for the pipe joint.
In this case, the inner side surface 4202 of the crimping nut 16'for the pipe joint and the side surface 2202 of the large diameter portion 22 of the joint body 14 make line contact or point contact instead of surface contact.
Therefore, the force is concentrated on the contacted portions and applied to the inner side surface 4202 and the side surface 2202, which is disadvantageous in improving the durability of the hose joint fitting 10, and also improves the withstand voltage performance of the hose joint fitting 10. It is also disadvantageous in planning.

Further, in the present embodiment, the angle θ formed by the inclined surface with respect to the plane P orthogonal to the axial direction of the cylindrical surface 4002 is in the range of 3 degrees to 12 degrees. By crimping the protrusion 42, it is advantageous to position the inner side surface 4202 on the plane P orthogonal to the axis of the cylinder 40.

In the present embodiment, the case where the pipe body is the hose 12 and the pipe joint is the hose joint fitting 10 has been described, but the present invention can be widely applied to a pipe joint connecting steel pipes and the like.

10 Hose fittings (pipe fittings)
14 Fitting body 16 Clamping nut for pipe joint 2202 Side surface 30 Recessed groove for mounting the tightening nut 38 Nut part 40 Cylinder part 4002 Cylindrical surface 42 Projection part 4202 Inner side surface

Claims (2)

The nut portion, a cylindrical portion that protrudes coaxially from the nut portion coaxially with the nut portion and has an inner peripheral portion formed on a cylindrical surface, and a cylindrical portion that protrudes inward in the radial direction at the tip of the tubular portion. With an annular protrusion having an inner surface that rises from the surface,
A crimping nut for a pipe joint in which the protrusion is rotatable in the concave groove of the joint body and is crimped by a crimping device so as to be movable in the axial direction of the joint body in the concave groove. And
The inner surface thereof is in a direction away from the cylinder portion as it goes from the cylindrical surface to the inside in the radial direction so that the inner surface surface and the side surface of the concave groove facing the inner surface surface are parallel to each other in the crimped state. Formed by an inclined surface that displaces in
A crimping nut for pipe fittings that is characterized by this. The angle θ formed by the inclined surface with respect to the plane orthogonal to the axial direction of the cylindrical surface is in the range of 3 degrees to 12 degrees.
The crimping nut for a pipe fitting according to claim 1.

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