JP2021020251A - Method for manufacturing press type pipe fitting - Google Patents

Abstract

To provide easily process and form an annular swelling part internally installing an O ring and a straight pipe part in a socket part of a press type pipe fitting for inserting a connection pipe to the socket part, reducing the diameter of the annular swelling part and both sides thereof, and fixing the connection pipe thereto, with high accuracy in a short time.SOLUTION: An expansion part and a tapered part are adjacently formed in a socket part by insertion of a core bar for diameter expansion, the expansion part and the tapered part are molded by a spinning processing method, and an annular swelling part and a straight pipe part are formed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a press-type pipe joint that is fastened and connected with a connection pipe inserted into a socket portion among mechanical joints constituting a piping system.

In a piping system that distributes fluid in multiple pipes, a so-called press type is used in which a predetermined amount of metal connection pipes (pipes) are inserted into the sockets of metal pipe joints and then tightened (tightened). Pipe fittings are often used. For example, as described in Japanese Patent No. 3436822, an elastic O-ring is attached to the inside (annular groove) of the annular bulge formed in the socket portion, and a predetermined amount of one end of the connecting pipe is inserted into the socket. While maintaining this state, the annular bulging portion and a part of the socket portions on both sides thereof are tightened to reduce the diameter, and the connecting pipe is airtightly / liquidtightly fixed.

Such a pipe joint is composed of a socket portion for accommodating and fixing a connecting pipe and a general portion. A receiving port for inserting a connecting pipe is opened in the socket portion, and an annular bulging portion is integrally formed in the vicinity thereof. Then, with the connecting pipe inserted into the socket portion and the annular bulge portion, the annular bulge portion and its vicinity (a part of the horizontal socket portion) are tightened with a press tool to reduce the diameter. At this time, the O-ring mounted in the annular bulge is compressed and adheres to the connecting pipe to exhibit the sealing function. Therefore, the cross-sectional shape of the annular bulge that compresses the O-ring is important. Then, there is a demand for a method for manufacturing a pipe joint so that such an annular bulge can be easily processed and formed in a short time.

Rolling, which is a type of rotary plastic working, is used to satisfy such needs and form an annular bulge. For example, in Japanese Patent No. 5376487, an O-ring is not installed, but an annular bulge for locking is formed in the pipe joint portion, and the end portion of the pipe joint portion is axially pressed from the inside. A rolling method for transferring the shape of a rotating roller by pressing the rotating roller is disclosed.

According to such a construction method, it is possible to easily form the annular bulging portion in a short time as compared with press working and stationary machining, but it is not possible to realize positive plastic flow of the machined part. Therefore, it is difficult to form the cross section of the annular bulge portion so as to be large enough to accommodate the O-ring. Further, since the shape of the rotating roller is transferred, a rotating roller is required for each desired cross section, and the versatility of processing is low.

Therefore, the present invention is a method for forming an annular bulge, which can realize a positive material flow (plastic flow) in forming an annular bulge, and can easily realize a cross-sectional size and an arbitrary shape in which an O-ring can be installed. Is to provide.

In order to solve the problem of the previous operation, the connecting pipe is inserted into the socket portion provided with the annular bulging portion containing the O-ring, and the connecting pipe is fixed by reducing the diameter of the annular bulging portion and its vicinity. In the method of manufacturing a press-type pipe joint, the first step of expanding the diameter of the open end of the socket portion over a certain range to form a tapered portion and a diameter-expanded portion, and over the tapered portion and the enlarged diameter portion. It was decided to include at least a second step of performing a spinning process to form an annular bulge portion having a desired cross-sectional shape and a straight pipe portion on the tip end side thereof.

Further, in the spinning process, at least a part of the socket portion is non-rotatably gripped, and the roller is moved in the tube axial direction and the radial direction while revolving contacting the roller over the enlarged diameter portion and the tapered portion to move the socket portion. It is preferable to integrally form an arbitrary annular bulging portion shape and a straight pipe portion shape.

Further, two diameter-expanded portions and tapered portions having different diameters may be formed by expanding the diameter of the socket portion in the first step, and spinning processing may be performed over the enlarged diameter portion and the tapered portion of the larger diameter portion.

According to the manufacturing method of the present invention, positive material flow (plastic flow) can be realized in the formation of the annular bulge portion of the press type pipe joint, and an arbitrary shape cross section in which the O-ring can be installed can be easily realized. Is.

In addition, a work fixed type (roller revolution type) that grips a part of the socket part non-rotatably and moves the roller in the pipe axis direction and the radial direction while making the roller revolve around the enlarged diameter part and the tapered part. By adopting the spinning process, if the clamp can be formed, an arbitrary annular bulging portion shape and a straight pipe portion shape can be obtained at the end portion of the pipe joint (work) having any shape.

Further, by forming two enlarged diameter portions and tapered portions having different diameters by expanding the diameter of the socket portion, in addition to the tapered portion for forming the annular bulging portion, the tapered portion as a stopper of the connecting pipe to be installed is also provided. , Can be formed at the same time and is efficient.

It is a figure which described the process of the processing method of the press type pipe joint which concerns on 1st Embodiment of this invention. It is a figure which described the 1st Embodiment of the press type pipe joint which concerns on the processing method of this invention. It is a figure which described the 2nd Embodiment of the press type pipe joint which concerns on the processing method of this invention.

Hereinafter, desirable embodiments of the present invention will be described with reference to FIG.

FIG. 1 describes a method of manufacturing the socket portion 20 in the press-type pipe joint 3 according to the first embodiment of the present invention for each step (a), (b), and (c). The process of FIG. (A) shows a state in which the material pipe 1 which is the material of the pipe joint 3 (and the socket portion) is firmly gripped by a clamp device (not shown). An opening 2 is opened at the end of the material pipe 1, and a mandrel (core metal) 4 for diameter expansion processing is inserted into the material pipe 1 from here in the next step (b). Push in the α direction by the pressing means.

In FIG. (B), as a result of the mandrel 4 being pushed into the material pipe 1 by a predetermined amount and the material pipe 1 being expanded in diameter, an opening 12, a large diameter portion 13, and a bent portion 18 are formed at the ends of the material pipe 1. A state in which the tapered portion 14, the medium diameter portion 15, the tapered portion 16, and the small diameter portion 17 (material pipe 1) are continuously formed is shown. The opening 12, the large diameter portion 13, and the bent portion 18 are formed by the large diameter portion 5 of the mandrel 4, and the tapered portion 14, the medium diameter portion 15, and the tapered portion 16 are the tapered portion 6, the medium diameter portion 7, and the tapered portion of the mandrel 4, respectively. Each of the tubes was expanded by 8. The small diameter portion 17 is still the material pipe 1 and is a non-processed portion. The above is the first step. Then, in the second step, molding is performed by the spinning processing method over the β range shown in FIG.

The spinning method is a kind of rotary plastic working and is a pipe drawing process using a rotating roller. Among them, in the present invention, a non-rotating work and roller revolving spinning method is selected. That is, a plurality of spinning rollers 21 revolving on an orbit coaxial with the axis of the material tube 1 move in the tube axis direction and the radial direction while revolving in contact with each other over the β range described above, thereby forming an arbitrary annular shape. The shape of the bulging portion 25 and the shape of the tip portion 24 are obtained. Specifically, the annular bulging portion 25 is formed by spinning the tapered portion 14 and the large diameter portion 13, and the tip portion 24 is obtained by spinning the large diameter portion 13.

At this time, if the spinning process is performed starting from the end portion of the adjacent medium diameter portion 15 as well as the tapered portion 14, the cross-sectional shape of the annular bulging portion 25 can be accurately realized, so that the spinning operation is performed over the β range. It is preferable to do so. However, if it is desired to change the shape of the tapered portion 14 only on the tip side of the bent portion 18 as it is, the spinning operation may be performed only in the γ range.

By the spinging construction as described above, the small diameter portion 17 to the tapered portion 16 to the intermediate portion 27 to the annular bulging portion 25 to the tip portion 24 can be continuously formed in the socket portion 20. Of course, an annular inner groove 26 for incorporating the O-ring is formed inside the annular bulge portion 25.

FIG. 2 shows a press type pipe joint 30 according to the first embodiment according to the processing method of the present invention. The shape is a straight, general, independent press type pipe joint. Socket portions 31 and 32, tip portions 33 and 41, annular bulging portions 34 and 40, intermediate portions 35 and 39, and tapered portions 36 and 38 on both sides of the small diameter portion 37 which remains as a material tube in the above-mentioned steps. Was formed coaxially.

FIG. 4 is a press-type pipe joint 50 of the second embodiment according to the processing method of the present invention. The press-type pipe joint 50 is not an independent pipe joint, but is integrated with the connection pipe 51 (integrally formed at the end of the connection pipe 51), and the socket portion 52 is the press-type pipe joint 50 (that is, the press-type pipe joint 50 ( Socket part). In this way, the press type pipe joint of the present invention may be integrated with the end of the connecting pipe having an arbitrary shape / length. According to the manufacturing method of the present invention, since it is a so-called "work fixed type" spinning method in which the spinning roller revolves around the work without rotating the work (work piece to be spun), a connecting pipe having a long or complicated shape is used. The press-type pipe joint of the present invention can be integrally formed at the end of the pipe.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and even if there is a change in the scope deviating from the gist of the present invention, the present invention is included in the present invention.

1 Material pipe 20, 31, 32, 52 Socket part 21 Spinning roller 26 Ring bulge part 3, 30, 50 Press type pipe joint

Claims (3)

This is a method for manufacturing a press-type pipe joint in which a connecting pipe is inserted into a socket portion having an annular bulging portion having an O-ring inside, and the connecting pipe is fixed by reducing the diameter of the annular bulging portion and its vicinity. hand,
The first step of expanding the diameter of the open end of the socket portion over a certain range to form a tapered portion and an enlarged diameter portion,
A second step of performing spinning processing over the tapered portion and the enlarged diameter portion to form an annular bulging portion having a desired cross-sectional shape and a straight pipe portion on the tip end side thereof.
A method for manufacturing a press-type pipe fitting, which comprises at least. In the spinning process, at least a part of the socket portion is non-rotatably gripped, and the roller is moved in the tube axial direction and the radial direction while revolving contacting the roller over the enlarged diameter portion and the tapered portion to form an arbitrary annular shape. It is characterized by obtaining a bulging portion shape and a straight pipe portion shape.
The method for manufacturing a press-type pipe joint according to claim 1. By expanding the diameter of the socket portion in the first step, two enlarged diameter portions and tapered portions having different diameters are formed, and the spinning process is performed over the enlarged diameter portion and the tapered portion of the larger diameter portion. Characteristic,
The method for manufacturing a press-type pipe fitting according to claim 1 or 2.

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