JP7087666B2 - Nipple and its manufacturing method - Google Patents

Description

The present invention relates to a nipple and a method for manufacturing the nipple, and more particularly to a nipple having a bend portion and manufactured by a friction welding method and a method for manufacturing the nipple.

The nipple constituting the hose joint hardware has a hose insertion portion in which a plurality of locking uneven portions extending in the circumferential direction are provided at intervals in the axial direction at the end thereof.
In the case of manufacturing a nipple having a bend portion at a pipe portion following the hose insertion portion together with such a hose insertion portion, conventionally, first, the end portion of the linear first pipe portion following the hose insertion portion and the first one. The end of the linear second pipe having the same outer diameter as the pipe is combined, and the ends of the first and second pipes are joined by the frictional pressure welding method to extend the third pipe in a straight line. It is a department.
Next, burrs generated by the friction welding method are removed from the third pipe portion, and the third pipe portion is bent by a mold to form a bend portion in the middle portion in the longitudinal direction of the third pipe portion.
In this case, conventionally, in order not to reduce the strength of the joint portion when removing burrs, a burr removing portion composed of a cylindrical surface having an outer diameter larger than the outer diameter of the first pipe portion and the second pipe portion is formed. I am doing it.

Japanese Unexamined Patent Publication No. 64-55496

However, when a deburring portion made of a cylindrical surface having an outer diameter larger than the outer diameter of the first pipe portion and the second pipe portion is formed, the deburring portion is caught in the mold during bending, and in particular, the deburring portion is caught in the mold. Stress concentration occurs on the radial outside of the bend portion on which the tensile force acts, and there is a possibility that an event such as breakage may occur when the bend portion is formed.
The present inventor has earnestly studied a deburring portion in which the ends of two pipe portions are joined by a friction welding method and the generated burrs are removed, and the present invention has been made. An object of the present invention is stress concentration. It is an object of the present invention to provide a nipple which is advantageous for bending without causing a problem and a method for manufacturing the nipple.

In order to achieve the above object, the present invention relates to the end of the linear first pipe portion following the hose insertion portion and the end of the linear second pipe portion having the same outer diameter as the first pipe portion. Is a nipple including a third pipe portion formed by joining by a frictional pressure welding method and a bend portion provided in an intermediate portion in the longitudinal direction of the third pipe portion, wherein the first and second pipe portions are provided. T1> It is characterized in that a deburring portion formed of a cylindrical surface having an outer diameter of a wall thickness T satisfying T ≧ T1 × 0.96 is formed.
Further, in the present invention, the end portion of the linear first pipe portion following the hose insertion portion and the end portion of the linear second pipe portion having the same outer diameter as the first pipe portion are combined and frictionally pressure-welded. By the method, the ends of the first and second pipe portions are joined to form a linearly extending third pipe portion, burrs generated during the frictional pressure welding are removed from the third pipe portion, and the first pipe portion is used with a mold. 3 A method for manufacturing a nipple that forms a bend portion in the middle portion in the longitudinal direction of the pipe portion, and includes a joint portion to which the ends of the first and second pipe portions are joined when the burr is removed. A burr removing portion made of a cylindrical surface having an outer diameter of a wall thickness T satisfying T1> T ≧ T1 × 0.96 is formed at a portion of the third pipe portion when the wall thickness of the third pipe portion is T1. It is characterized by that.
Further, in the present invention, the end portion of the linear first pipe portion following the hose insertion portion and the end portion of the linear second pipe portion having the same outer diameter as the first pipe portion are combined and frictionally pressure-welded. By the method, the ends of the first and second pipe portions are joined to form a linearly extending third pipe portion, and the third pipe portion is provided with a deburring portion from which burrs generated during frictional pressure welding are removed. A method for manufacturing a nipple, which is formed by forming a cylindrical surface having a size larger than the outer diameter of the third pipe portion and forming a bend portion in the middle portion in the longitudinal direction of the third pipe portion by a mold. Is provided with a relief portion that does not come into contact with the burr removing portion, and when the bend portion is formed by the mold, the burr removing portion is prevented from coming into contact with the mold by the relief portion.

The present inventor has a case where the ends of two pipe portions are joined by a friction welding method, and the deburring portion from which the burrs generated at the time of joining is removed is formed by a cylindrical surface having an outer diameter or less of the pipe portions. Even so, it has been found that when the wall thickness of the deburring portion is within a predetermined range, the strength of the joint portion is higher than that of the pipe portion other than the joint portion.
Therefore, according to the present invention, the deburring portion does not get caught in the mold and stress concentration does not occur during the bending process, so that the bending process can be performed without damaging the third pipe portion and the strength is excellent. It is advantageous in obtaining a nipple.
Further, according to the present invention, since the burr removing portion does not come into contact with the mold during the bending process by the relief portion, the burr removing portion does not get caught in the mold during the bending process. Therefore, stress concentration does not occur, bending can be performed without damaging the third pipe portion, which is advantageous in obtaining a nipple having excellent strength.

It is a half sectional view of the hose joint metal fitting which is composed of the nipple of 1st Embodiment. (A) to (D) are explanatory views of the manufacturing process of the nipple of the first embodiment. (A) to (C) are explanatory views for setting the nipple of the first embodiment in the mold. It is explanatory drawing of the state which the nipple of 1st Embodiment was set in the mold which is located at the initial position of machining. It is explanatory drawing that the pressure die and the bending die make a circular motion integrally from the state of FIG. It is explanatory drawing of the state in which the bend processing is completed. (A) is a cross-sectional view taken along the line AA of FIG. 4, and (B) is a cross-sectional view taken along the line BB of FIG. (A) and (B) are explanatory views of an experimental example. It is sectional drawing of the mold which concerns on 2nd Embodiment, and is explanatory drawing of the state in which the bend processing was completed.

Next, the present embodiment will be described with reference to the drawings.
(First Embodiment)
First, the hose joint hardware to be manufactured will be described.
As shown in FIG. 1, the hose joint hardware 10 includes a nipple 12, a socket 14, and a flange 16.
The nipple 12 has a hose insertion portion 18, a straight portion following the hose insertion portion 18, a bend portion 20 following the straight portion, and a straight portion following the bend portion 20.
The hose insertion portion 18 is configured by providing a plurality of locking uneven portions 1802 extending in the circumferential direction on the outer peripheral portion thereof at intervals in the axial direction.
A socket crimping groove 1804 is provided at the end of the hose insertion portion 18, and a collar portion 1806 is provided at the end of the socket crimping groove 1804.
The socket 14 is arranged by crimping one end in the longitudinal direction to the socket crimping groove 1804, and an annular space S for hose insertion is formed between the socket 14 and the hose insertion portion 18.
A hose (not shown) is inserted into this annular space S, and the socket 14 is crimped to connect the hose and the hose joint hardware 10.
The flange 16 is attached to the end of the straight portion by welding, friction welding, or brazing. The flange 16 is a place to be attached to a mounting seat around the fluid flow opening on the device side.
Depending on the type of hose joint hardware 10, a cap nut or the like may be provided instead of the flange 16.

Conventionally, such a nipple 12 is manufactured as follows.
As shown in FIG. 2A, an end portion 2202 having a flat surface of the linear first pipe portion 22 following the hose insertion portion 18, and a linear second portion having an outer diameter equal to that of the first pipe portion 22. The end portions 2402 having a flat surface of the pipe portion 24 are combined, and as shown in FIG. 2B, the end portions 2202 and 2402 of the first and second pipe portions 22 and 24 are joined by a friction pressure welding method. The third pipe portion 26 extending in a straight line is used. In FIG. 2B, reference numeral 25 indicates a joint portion between the first pipe portion 22 and the second pipe portion 24.
Next, as shown in FIG. 2C, the burr 28 generated by the friction welding method is removed from the third pipe portion 26, and the size of the third pipe portion 26 or less is smaller than the outer diameter of the third pipe portion 26 at the location where the friction welding method is performed. A burr removing portion 30 is formed of a cylindrical surface having an outer diameter of.
Next, as shown in FIG. 2D, the third pipe portion 26 is bent by a mold to form a bend portion 20.
The bend portion 20 is formed in an intermediate portion in the longitudinal direction of the second pipe portion 24.
In the third pipe portion 26 in which the bend portion 20 is formed, the portion of the second pipe portion 24 following the bend portion 20 on the deburring portion 30 side is the first straight line portion 2410 extending coaxially with the first pipe portion 22. The portion of the second pipe portion 24 that continues to the bend portion 20 on the opposite side of the deburring portion 30 is a second straight portion 2412 that extends linearly.

Here, a mold for forming the bend portion 20 with respect to the third pipe portion 26 extending linearly will be described.
As shown in FIGS. 3A to 3C, the mold 32 includes a pressure mold 34, a tightening mold 36, a bending mold 38, and a mandrel 40.
As shown in FIGS. 3C and 4, the pressure mold 34 has a bend portion to be machined with respect to the third pipe portion 26 extending linearly at the initial position (machining set position) in bend machining. 20 is abutted against the first straight line portion 2410, the deburring portion 30, the first pipe portion 22, and the half portion of the hose insertion portion 18 extending continuously and linearly on the outer peripheral surface of the outer half portion in the radial direction. As shown in 7 (A), it has a mold surface 3402 in the shape of half of them.
The tightening die 36 and the bending die 38 rotate integrally around the rotation center 42.
As shown in FIGS. 3C and 4, the tightening die 36 is arranged continuously with the pressure die 34 with respect to the third pipe portion 26 extending linearly at the initial position in bending. It abuts on the linear third pipe portion 26 following the first straight portion 2410, and as shown in FIG. 7B, corresponds to the outer peripheral surface of the radial outer half of the bend portion 20 to be machined. It has a mold surface of 3602 in shape and is formed to be shorter in length than the pressure mold 34.

As shown in FIGS. 4 to 6 and 7 (B), the bending die 38 has a bend portion 20 to be machined with respect to the third pipe portion 26 extending linearly at the initial position in bending. It has a mold surface 3802 extending in an arc shape in a shape corresponding to the outer peripheral surface of the inner half portion in the radial direction.
As shown in FIGS. 3C and 4, the bending die 38 is the end of the bend portion 20 to be machined on the first straight line portion 2410 side in the extending direction of the mold surface 3802 at the initial position in the bending process. The portion of the end portion 3802A of the mold surface 3802 corresponding to the portion is positioned at a portion separated below the bend portion 20 to be machined at the portion of the third pipe portion 26 extending linearly, and extends linearly. Bend portion to be machined on the second straight line portion 2412 side in the extending direction of the mold surface 3802 at a portion corresponding to the end portion of the bend portion 20 to be machined on the second straight line portion 2412 side in the third pipe portion 26. The portion of the end portion 3802B of the mold surface 3802 corresponding to the end portion of 20 is abutted.

As shown in FIG. 3 (B), if the third pipe portion 26 extending linearly is set on the bending die 38 located at the initial position, it is shown in FIGS. 3 (C) and 4 (C). As such, the mandrel 40 is inserted into the third pipe portion 26 from the hose insertion portion 18 and to the first straight portion 2410.
In the pressure mold 34 and the mandrel 40, when the bend portion 20 is machined, the first straight portion 2410 is directed toward the second straight portion 2412 along the longitudinal direction of the third pipe portion 26 located at the initial position. A hydraulic cylinder (not shown) having an axial center direction extending in a direction parallel to the longitudinal direction of the third pipe portion 26 is connected so that the pressure mold 34 and the mandrel 40 are moved by a predetermined movement amount. ing.

Then, the tightening die 36 and the pressure die 34 are moved to the initial positions, and as shown in FIGS. 4 to 6, the tightening die 36 and the bending die 38 are integrally rotated around the rotation center 42. As a result, the bend portion 20 is formed.
In this case, the mold surface 3602 of the tightening mold 36 is in contact with the outer peripheral surface of the third pipe portion 26, and the mold surface 3802 of the bending mold 38 is in contact with the third pipe portion 26 along the arc direction thereof. The area will increase.
When the bend portion 20 is formed, a tensile stress is generated in the radial outer half of the bend portion 20, and this tensile stress is also generated in the half of the first pipe portion 22 connected to the radial outer half of the bend portion 20. Compressive stress acts on the inner half of the bend portion 20 in the radial direction.

In the first embodiment, the wall thickness of the third pipe portion 26 is set to T1 at the location of the third pipe portion 26 including the joint portion 25 to which the ends of the first and second pipe portions 22 and 24 are joined. When this is done, a burr removing portion 30 made of a cylindrical surface having an outer diameter of a wall thickness T satisfying T1 ≧ T ≧ T1 × 0.96 is formed.
As shown in FIGS. 8A and 8B, the present inventor conducted an experiment on the burr removing unit 30.
The material of the first and second pipe portions 22 and 24 is STKM13AS.
Five test pieces were made for Experimental Example 1, Experimental Example 2, and Experimental Example 3 for three types having different inner diameters D1 and wall thickness T1 for the first and second pipe portions 22 and 24.
In Experimental Example 1, Experimental Example 2, and Experimental Example 3, the burr removing portion 30 was formed with an outer diameter D and a wall thickness T.
The axial length of the deburring portion 30 was set to 10 mm.
Then, both ends of each of the test pieces of the experimental example were set in a tensile tester, and a tensile load was applied until they broke.

As a result, in any of the test pieces of Experimental Examples 1, 2 and 3, the pieces were broken at places other than the deburring portion 30.
That is, as a result of diligent research by the present inventor, the burr removing portion 30 from which the end portions 2202 and 2204 of the two pipe portions 22 and 24 are joined by the friction welding method and the generated burrs 28 are removed is the pipe portions 22 and 24. Even if it is formed of a cylindrical surface with an outer diameter or less of, if it has a wall thickness within a predetermined range, the strength of the joint portion 25 is higher than that of the pipe portions 22 and 24 other than the joint portion 25. It turned out to be large.

In the first embodiment, since the burr removing portion 30 is formed of a cylindrical surface having an outer diameter or less of the third pipe portion 26, the burr removing portion 30 presses when the bend portion 20 is formed by the mold 32. It does not get caught on the mold surface 3402 of the mold 34.
Therefore, when the bend portion 20 is formed, stress concentration does not occur at the portion of the burr removing portion 30, and the tensile load is applied to the entire length of the radial outer half of the third pipe portion 26 excluding the hose insertion portion 18. This is advantageous in preventing damage during formation of the bend portion 20.
Therefore, according to the first embodiment, bend processing can be performed without stress concentration, which is advantageous in manufacturing a nipple 12 having excellent strength.

(Second embodiment)
Next, a second embodiment will be described.
In the following description of the embodiment, the same parts and members as those in the first embodiment are designated by the same reference numerals, the description thereof will be omitted, and different parts will be mainly described.
As shown in FIG. 9, in the second embodiment, when the burr 28 generated by the friction welding method is removed from the third pipe portion 26 and the burr removing portion 30 is formed at the friction welding method, the burr removing portion 30 is formed. The burr removing portion 30 is formed of a cylindrical surface having a size larger than the outer diameter of the third pipe portion 26.
On the other hand, the mold 32 is provided with a relief portion 44 that does not come into contact with the burr removing portion 30, and when the third pipe portion 26 is bent by the mold 32, the burr removing portion 30 is not brought into contact with the mold 32 by the relief portion 44. It is something like that.
That is, at least when the bend portion 20 is formed, a relief portion 44 that does not come into contact with the burr removing portion 30 is provided at a portion of the mold 32 corresponding to the burr removing portion 30 at the portion of the third pipe portion 26 where tensile stress is generated, and the metal is provided. When the bend portion 20 is formed by the mold 32, the burr removing portion 30 is prevented from coming into contact with the mold 32 by the relief portion 44.
Specifically, the pressure mold 34 is provided with a relief portion 44 that does not come into contact with the burr removing portion 30, and the relief portion 44 is composed of a concave groove 3410 formed on the mold surface 3402 of the pressure mold 34. ing.
The concave groove 3410 has a depth M that does not contact the deburring portion 30 and an axial length L that is larger than that of the deburring portion 30, and is formed so as to extend over the entire circumference of the mold surface 3402 in the circumferential direction.

Even in such a second embodiment, the burr removing portion 30 does not get caught on the mold surface 3402 of the pressure mold 34 when the bend portion 20 is formed by the mold 32.
Therefore, when the bend portion 20 is formed, no stress is generated at the portion of the burr removing portion 30, which is advantageous in preventing the third pipe portion 26 from being damaged.
Therefore, according to the second embodiment, the bend processing can be performed without causing stress concentration, which is advantageous in manufacturing the nipple 12 having excellent strength.
In this case, it is more advantageous to provide a relief portion that does not come into contact with the burr removing portion 30 at the mold surface 3802 of the bending die 38 corresponding to the burr removing portion 30 in order to smoothly perform the bend processing. Become.

10 Hose fitting hardware 12 Nipple 18 Hose insertion part 20 Bend part 22 First pipe part 2202 End part 24 Second pipe part 2402 End part 25 Joint part 26 Third pipe part 28 Burr 30 Deburring part 32 Mold 44 Missing part

Claims (5)

The end of the linear first pipe portion following the hose insertion portion and the end of the linear second pipe portion having the same outer diameter as the first pipe portion were joined by a frictional pressure welding method. A third pipe portion, a bend portion provided in the middle portion in the longitudinal direction of the third pipe portion, and a bend portion.
It is a nipple equipped with
The thickness of the third pipe portion is obtained by removing burrs generated during the friction welding at the portion of the third pipe portion including the joint portion where the ends of the first and second pipe portions are joined by the friction welding method. When T1 is set, a deburring portion formed of a cylindrical surface having an outer diameter of a wall thickness T satisfying T1> T ≧ T1 × 0.96 is formed.
A nipple that features that. The bend portion is formed at a portion of the second pipe portion away from the joint portion in a direction away from the first pipe portion.
The nipple according to claim 1, wherein the nipple is characterized in that. Align the end of the linear first pipe portion following the hose insertion portion with the end of the linear second pipe portion having the same outer diameter as the first pipe portion.
By the friction welding method, the ends of the first and second pipe parts are joined to form a linearly extending third pipe part.
The burr generated during the friction welding is removed from the third pipe portion, and the burr is removed.
A method for manufacturing a nipple in which a bend portion is formed in an intermediate portion in the longitudinal direction of the third pipe portion by a mold.
When removing the burrs, when the wall thickness of the third pipe portion is T1 at the location of the third pipe portion including the joint portion to which the ends of the first and second pipe portions are joined, T1 . A deburring portion made of a cylindrical surface having an outer diameter of a wall thickness T satisfying > T ≧ T1 × 0.96 is formed.
A method of manufacturing a nipple, which is characterized by the fact that. The bend portion is formed at a portion of the second pipe portion away from the joint portion in a direction away from the first pipe portion.
The method for manufacturing a nipple according to claim 1, wherein the nipple is manufactured. Align the end of the linear first pipe portion following the hose insertion portion with the end of the linear second pipe portion having the same outer diameter as the first pipe portion.
By the friction welding method, the ends of the first and second pipe parts are joined to form a linearly extending third pipe part.
A burr removing portion from which burrs generated during friction welding was removed was formed on the third pipe portion with a cylindrical surface having a size larger than the outer diameter of the third pipe portion.
A method for manufacturing a nipple in which a bend portion is formed in an intermediate portion in the longitudinal direction of the third pipe portion by a mold.
The mold is provided with a relief portion that does not come into contact with the deburring portion.
When the bend portion was formed by the mold, the burr removing portion was prevented from coming into contact with the mold by the relief portion.
A method of manufacturing a nipple, which is characterized by the fact that.

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