JP2015080789A - Pipe body joining structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pipe body joining structure which can create a substantially-uniform curl at a joining part.SOLUTION: A pipe body joining structure 10 comprises a pipe material 12 as one pipe body whose portion including an end face 12C at an axial one end side is formed into a flat shape, and a straight pipe 20 as the other cylindrical pipe body whose projection face of an end face of the pipe material 12 viewed from an axial direction becomes the inside of a circular end face. The pipe body joining structure 10 also comprises a joining part 26 in which the end face 12C of the pipe material 12 and an end face 20A of the straight pipe 20 are joined to each other by friction-pressure welding.

Description

  The present invention relates to a tube joint structure.

  Conventionally, one pipe body and the other pipe body are butted and welded.

  In Patent Document 1 below, the end surface of one metal tube formed in a cylindrical shape and the other metal tube in a cylindrical shape set to substantially the same size (inner diameter and outer diameter) as one metal tube body are disclosed. A method is disclosed in which the end surface of one metal tube body and the end surface of the other metal tube body are joined by welding in a state in which the end surface of the tube body is abutted. At that time, curls (burrs) are generated on the outer peripheral side and the inner peripheral side at the joint between one metal tube and the other metal tube.

JP 2010-155265 A

  In the tube welding method described in Patent Document 1, the portion including the end surface of one metal tube and the portion including the end surface of the other metal tube have substantially the same size (inner diameter and outer diameter). Is set.

  On the other hand, for example, when one metal pipe body is bent, the end side of one metal pipe body may be deformed into a flat shape. In this case, when friction welding is performed by abutting the end surface of the other metal tube formed in a substantially circular shape with the end surface of the one metal tube deformed into a flat shape, Parts that do not touch may occur. For this reason, the time for the end faces of the two tube bodies to reach a predetermined melting temperature is delayed, or the reaching temperature is lowered, and it is difficult to generate a uniform curl.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a tubular joint structure capable of generating a substantially uniform curl at a joint portion.

  In order to solve the above-described problem, the tubular structure according to the first aspect of the present invention is seen from the axial direction, with one tubular body having a flat portion including the end face on one axial end side. The projection surface of the end face of the one tubular body is in the circular end face, and the other tubular tubular body is joined to the end face of the one tubular body and the end face of the other tubular body by friction welding. And a joint portion.

  According to the first aspect of the present invention, the one tubular body has a flat shape at a portion including the end face on one end side in the axial direction. The other tube body is cylindrical, and the projection surface of the end surface of one tube body viewed from the axial direction is within the circular end surface of the other tube body. The end surface of one tube body and the end surface of the other tube body are joined by friction welding. In this configuration, since the projection surface of the end surface of one tube body viewed from the axial direction is within the circular end surface of the other tube body, the end surface of one tube body and the end surface of the other tube body are friction-welded. When joining by this, it is possible to make the end surface of the other tube body contact the substantially whole end surface of the one tube body in which the part including the end surface has a flat shape. For this reason, it becomes possible to melt the end surfaces by a substantially uniform temperature rise and a substantially uniform reaching temperature at the time of friction welding, and it is almost uniform at the joint between the end surface of one tube body and the end surface of the other tube body. Curls can be generated.

  The invention according to claim 2 is the tube joint structure according to claim 1, wherein the outer diameter of the end surface of the other tube body is larger than the outer diameter of the long diameter portion of the end surface of the one tube body, or equal.

  According to the invention described in claim 2, the outer diameter of the end face of the other tubular body is greater than or equal to the outer diameter of the long diameter portion of the end face of the one tubular body. For this reason, when joining the end surface of one tubular body and the end surface of the other tubular body by friction welding, the end surface of the other tubular body can be more reliably brought into contact with almost the entire end surface of the one tubular body. Is possible.

  According to the tubular structure of the present invention, a substantially uniform curl can be generated at the joint.

It is sectional drawing which shows the tube body junction structure which concerns on one Embodiment of this invention. It is a side view which shows the state before joining the end surface of one tubular body and the end surface of the other tubular body to which the tubular body joining structure which concerns on one Embodiment of this invention is applied. It is a side view explaining the state which joins the end surface of one tubular body to which the tubular body junction structure concerning one embodiment of the present invention is applied, and the end surface of the other tubular body. It is sectional drawing which expands and shows the junction part of the end surface of one tubular body and the end surface of the other tubular body to which the tubular body joint structure concerning one Embodiment of this invention is applied. It is sectional drawing which shows the pipe joint structure of a comparative example. It is a side view which shows the state before joining the end surface of one tubular body to which the tubular body joining structure of a comparative example is applied, and the end surface of the other tubular body. It is a side view explaining the state which joins the end surface of one tubular body to which the tubular body joining structure of a comparative example is applied, and the end surface of the other tubular body.

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

  FIG. 1 is a cross-sectional view showing one tubular body and the other tubular body provided with a tubular body joining structure 10 according to an embodiment of the present invention. FIG. 2 is a side view showing a state before joining one tubular body and the other tubular body provided with a tubular body joining structure 10 according to an embodiment of the present invention. FIG. 3 is a side view showing a state in which one tubular body provided with the tubular body joining structure 10 according to one embodiment of the present invention is joined to the other tubular body.

  As shown in FIGS. 1 to 3, the pipe joint structure 10 includes a pipe member 12 as one pipe body that has been bent, and a straight pipe 20 as the other pipe body.

  The pipe material 12 is formed by bending a cylindrical tube body formed straight. In this embodiment, the pipe member 12 is bent into a substantially L shape so that the bent portion 12A has a curved shape, and includes a pipe portion 12B extending substantially straight at one end side in the axial direction. The pipe material 12 is formed of a material that can be joined to the straight pipe 20 by friction welding. In this embodiment, the pipe material 12 is, for example, a carbon steel pipe for hydraulic piping such as OST-2 (trade name) or STKM (trade name).

  The pipe material 12 is a portion including the end surface 12C on the one end side in the axial direction of the pipe portion 12B by bending the cylindrical tube body while holding the end portion of the cylindrical tube body formed straight. Is a flat shape slightly deformed flat. Thereby, as FIG. 1 shows, the pipe part 12B of the pipe material 12 has a bias | deviation in the magnitude | size of an outer diameter with the position of an outer peripheral surface.

  As shown in FIGS. 1 to 3, the straight tube 20 is formed in a cylindrical shape. The inner diameter of the straight pipe 20 is set to be substantially the same as the inner diameter of the pipe material 12 (cylindrical tubular body formed straight) before being subjected to bending. In the straight pipe 20, the outer diameter of the end surface 20A (A in FIG. 1) is the outer diameter of the long diameter portion of the end surface 12C of the pipe portion 12B of the pipe material 12 (the outer diameter of the end surface 12C in the major axis direction, B in FIG. ) (See FIG. 1).

  In the present embodiment, the outer diameter of the end surface 20A of the straight pipe 20 is set to be approximately equal to the outer diameter of the long diameter portion of the end surface 12C of the pipe portion 12B of the pipe material 12, but the outer diameter of the end surface 20A of the straight pipe 20 is The diameter may be larger than the outer diameter of the long diameter portion of the end surface 12C of the pipe portion 12B of the pipe material 12.

  In this embodiment, the straight pipe 20 has an inner diameter that is set to be substantially the same as the inner diameter of the pipe material 12 (a cylindrical tube formed in a straight shape) before being bent. You may set smaller than the internal diameter of the pipe material 12 (cylindrical tubular body formed straight) before processing. That is, the inner diameter of the straight tube 20 may be equal to or smaller than the inner diameter of the pipe material 12 (a cylindrical tube body formed in a straight shape) before being bent.

  The straight pipe 20 is formed of a material that can be joined to the pipe material 12 by friction welding. In the present embodiment, the straight pipe 20 is formed of, for example, a structural carbon steel pipe such as S20C (trade name).

  As shown in FIG. 1, the projection surface of the end surface 12 </ b> C of the pipe material 12 viewed from the axial direction is configured to be within the circular end surface 10 </ b> A of the straight tube 20. In this state, as shown in FIG. 3, the end surface 20 </ b> A on the one end side in the axial direction of the straight tube 20 and the end surface 12 </ b> C of the pipe portion 12 </ b> B of the pipe material 12 are joined by friction welding.

  As a result, as shown in FIG. 4, a joint portion 26 is formed in which the end surface 20A of the straight pipe 20 and the end surface 12C of the pipe portion 12B of the pipe material 12 are joined by friction welding. The end surface 20A of the straight pipe 20 and the end surface 12C of the pipe portion 12B of the pipe material 12 are joined by friction welding, so that curls (burrs) 28, 30 are formed on the outer peripheral surface side and the inner peripheral surface side of the joint portion 26. Has been generated. Here, friction welding refers to a technique in which members to be joined (for example, metal, resin, etc.) are rubbed together at high speed, and the members are softened by the frictional heat generated at the same time and simultaneously applied with pressure.

  Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 2, a pipe member 12 having a curved bent portion 12A is formed by bending a straight cylindrical tube (not shown). As shown in FIG. 1, the pipe material 12 is formed by bending a straight cylindrical tube body, so that the portion including the end surface 12C of the pipe portion 12B on one end side in the axial direction is slightly flattened. It is a deformed flat shape. In addition, formation of the pipe material 12 may perform a bending process in a factory previously, and may perform a bending process on the spot.

  As shown in FIGS. 1 and 2, the straight pipe 20 is formed in a cylindrical shape, and the inner diameter of the straight pipe 20 is the pipe material 12 (a cylindrical shape formed in a straight shape) before being bent. The inner diameter of the tube body) is set to be substantially the same. In addition, the outer diameter A of the outer peripheral portion 22 of the straight pipe 20 is set to be approximately equal to the outer diameter B (the outer diameter in the major axis direction) of the long diameter portion of the end face 12C of the pipe portion 12B of the pipe material 12 that is flat. ing. The outer diameter A of the outer peripheral portion 22 of the straight pipe 20 is set to be larger than the outer diameter B (outer diameter in the major axis direction) of the longer diameter portion of the end surface 12C of the pipe portion 12B of the pipe material 12 that is flat. Also good. That is, the outer diameter A of the outer peripheral portion 22 of the straight pipe 20 may be equal to or greater than the outer diameter B of the long diameter portion of the end surface 12C of the pipe portion 12B of the pipe material 12 (A ≧ B).

  Thereby, as shown in FIG. 1, the projection surface of the end surface 12 </ b> C of the pipe material 12 as viewed from the axial direction is within the circular end surface 10 </ b> A of the straight tube 20.

  As shown in FIGS. 1 and 3, the end surface 12 </ b> C of the pipe portion 12 </ b> B of the pipe material 12 is brought into contact with the end surface 20 </ b> A on the one axial end side of the straight tube 20. Then, the end surface 20A of the straight pipe 20 and the end surface 12C of the pipe portion 12B of the pipe material 12 are joined by friction welding (see FIG. 4).

  At that time, as shown in FIG. 1, the projection surface of the end surface 12C of the pipe material 12 viewed from the axial direction is in the circular end surface 10A of the straight pipe 20, so that almost the entire end surface 12C of the pipe material 12 is formed. The end face 20A of the straight tube 20 can be brought into contact. For this reason, at the time of friction welding between the end surface 20A of the straight pipe 20 and the end surface 12C of the pipe material 12, the end surfaces 20A and 12C can be melted by a substantially uniform temperature rise and a substantially uniform reached temperature. For this reason, substantially uniform curls (curls without unevenness) 28 and 30 can be generated on the outer peripheral surface side and the inner peripheral surface side of the joint portion 26 between the end surface 20A of the straight pipe 20 and the end surface 12C of the pipe material 12. .

  In the tube joint structure 10 according to the present embodiment, the straight tube 20 is set so that the inner diameter is substantially the same as the inner diameter of the pipe material 12 (cylindrical tubular body formed straight) before being bent. In addition, only the outer diameter of the outer peripheral portion 22 is set to be larger than the outer diameter of the long diameter portion of the pipe material 12. As a result, the entire end surface 12C of the long diameter portion of the pipe material 12 can be brought into contact with the end surface A of the straight tube 20, and is substantially uniform at the time of friction welding between the end surface 20A of the straight tube 20 and the end surface 12C of the pipe material 12. An increase in temperature and an almost uniform reached temperature can be achieved.

  Further, when the pipe material 12 is formed of a carbon steel pipe for hydraulic piping, the straight pipe 20 is formed of a structural carbon steel pipe, and the end face 12C of the pipe material 12 and the end face 20A of the straight pipe 20 are pressure-welded, The pipe material 12 is easier to melt than the straight tube 20. In this case, if a non-contact portion between the end faces of the two tubular bodies is generated, the influence on the appearance of the joint is great.

  In the present embodiment, the outer diameter of the straight pipe 20 is reduced to the pipe portion 12B of the pipe material 12 so as not to impair the appearance of the joint portion 26 between the pipe material 12 and the straight pipe 20 in which the portion including the end face 12C is flat. It is slightly larger than the outer diameter. Thereby, the external appearance of the junction part 26 can be improved by making the end surface 20A of the straight pipe | tube 20 contact the substantially whole end surface 12C of the pipe material 12, and performing friction welding. That is, in this embodiment, since the outer peripheral portion 22 of the pipe material 12 in which the portion including the end surface 12C is flattened does not protrude outward in the radial direction of the straight tube 20, the appearance of the joint portion 26 of the tubular body joint structure 10 Can be reduced.

  5 to 7 show a pipe joint structure 100 of a comparative example. As shown in FIGS. 5 to 7, the pipe joint structure 100 of the comparative example includes a pipe member 102 that has been bent and a straight pipe 110 as one pipe body.

  In such a pipe joint structure 100, the inner diameter and the outer diameter of the straight pipe 110 are approximately the same as the inner diameter and the outer diameter of the pipe material 102 (a cylindrical tube body formed in a straight shape) before being subjected to bending. Are set the same. As shown in FIG. 5, in the pipe material 102 obtained by bending a cylindrical tube body, a portion including the end face 102C of the pipe portion 102A is deformed into a flat shape. For this reason, when the end surface 110A of the straight pipe 110 formed in a substantially circular shape and the end surface 102C of the pipe material 102 are friction-welded, a portion that does not come into contact with the mating part is generated. As a result, the time for reaching the melting temperature at the pressure contact portion between the end surface 110A of the straight pipe 110 and the end surface 102C of the pipe material 102 is delayed or the temperature at which the temperature reaches is low, so that uniform curling is generated at the joint 114. It becomes difficult.

  In such a case, it is necessary to use a lot of energy at the time of friction welding between the end surface 110A of the straight pipe 110 and the end surface 102C of the pipe material 102, and to make the non-uniformity by melting more. However, in such a method, it is necessary to use wasted energy or to adjust the component dimensions by trial and error.

  On the other hand, in the tube joint structure 10 of the present embodiment, the projection surface of the end surface 12C of the pipe material 12 viewed from the axial direction is in the circular end surface 20A of the straight tube 20, and therefore the end surface 12C of the pipe material 12 The end face 20A of the straight tube 20 can be brought into contact with almost the entire surface. For this reason, at the time of friction welding between the end face 20A of the straight pipe 20 and the end face 12C of the pipe material 12, the pressure contact portion can be brought to a substantially uniform temperature rise and a substantially uniform reached temperature, and the joint portion 26 has a substantially uniform curl. 28, 30 can be generated.

  In addition, the outer diameter of the outer peripheral part 22 of the straight pipe 20 and the outer diameter of the pipe part 12B of the pipe material 12 are not limited to the structure of FIG. The outer diameter of the outer peripheral portion 22 of the end face 20A of the straight pipe 20 is set to be equal to or greater than the outer diameter (outer diameter in the major axis direction) of the long diameter portion of the end face 12C of the pipe portion 12B of the pipe member 12 that is flat. For example, the actual dimensions can be changed.

DESCRIPTION OF SYMBOLS 10 Tubular joint structure 12 Pipe material 12A Bending part 12B Pipe part 12C End surface 20 Straight pipe 20A End surface 22 Outer peripheral part 26 Joint part 28, 30 Curl

Claims (2)

One tubular body in which the portion including the end face on one end side in the axial direction is a flat shape,
A projection surface of the end surface of the one tube body as viewed from the axial direction, and the other tubular tube body in a circular end surface;
A joined portion in which the end face of the one tubular body and the end face of the other tubular body are joined by friction welding;
A tube joint structure having   The tube joint structure according to claim 1, wherein an outer diameter of an end surface of the other tube body is larger than or equal to an outer diameter of a long diameter portion of an end surface of the one tube body.

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