JP2009192059A - Piping and pipe end working method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide female piping that is low in material cost and working cost and is easy to connect with male piping with high connection reliability. <P>SOLUTION: The female piping 20, which has a radially expanded portion 1 expanded from an inside diameter ID<SB>2</SB>by plastic working at one end 20a, has a radially outwardly projecting flange portion 1a formed by plastic working of an outer open end of the radially expanded portion, and accommodates male piping inserted in the radially expanded portion for connection with the male piping, is provided with a ring 5 mounted on the radially expanded portion axially inward of the flange portion. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe and a pipe end processing method, and more particularly to a female side pipe used as a pipe joint and a pipe end processing method when the pipe is manufactured.

  As a method for connecting two pipes, for example, a method specifically described in Patent Document 1 is known. In this method, a block body having a union screw is welded (brazed) to the connection end side of one pipe (pipe body), and a block body having a union nut is welded to the connection end side of the other pipe (pipe body). Then, the two pipes are connected by screwing the union screw and the union nut together. However, in this connection method, since the block body must be welded (brazed) to each pipe, the number of parts increases and the cost for connection increases, and it is relatively difficult to obtain a pipe to which the block body is connected. Complicated work is required.

  For this reason, a method is also proposed in which a pipe having a joint structure is obtained by plastic working of the raw pipe, and this pipe and another pipe are directly connected by a method other than welding. For example, in Patent Document 2, a female pipe (female side structure) in which the inner diameter of one end side of the raw pipe is enlarged and the one end side is plastically deformed to form a curled flange portion is sealed at one end side. A method of inserting a male side pipe (male side structure) to which a material is attached and fixing and connecting with a clamp-like connecting member having an elongated hole into which the flange portion is inserted instead of welding them. Is described. The one end side of the female pipe used in this method is such that a female mold is fixed to the end of the raw pipe, and a molded part of a predetermined shape provided on the male mold is inserted into the inside from the end of the raw pipe. The inner diameter is expanded by plastic working of press-fitting.

JP 2002-22074 A JP 2004-316786 A

  Although the female side pipe (female side structure) described in Patent Document 2 is manufactured by plastic processing of the raw pipe, it has an advantage of easily reducing the manufacturing cost. Since the strength of the flange part formed by plastic working of the side is lower than the strength of the raw pipe, when a thin raw pipe is used, the flow where the female pipe and the male pipe are connected When water, hot water, or the like is flowed through the road, the flange portion may be deformed by a load in the tube axial direction applied to the connection portion of both pipes. Deformation of the flange portion of the female pipe can cause water leakage from the connection point. Of course, if the thickness of the raw pipe is increased, deformation of the flange portion in the female pipe can be prevented. However, increasing the thickness of the raw pipe causes an increase in material cost and processing cost.

  The present invention has been made in view of the above circumstances, and it is easy to suppress material costs and processing costs, and to produce a female-side pipe that is easy to connect with a male-side pipe under high connection reliability, and the pipe. It aims at obtaining the pipe end part processing method at the time of doing.

  The pipe of the present invention has an enlarged diameter portion whose inner diameter is enlarged by plastic working at one end side, and has a flange portion that is formed by plastic working of the outer opening end portion of the enlarged diameter portion and projects outward in the radial direction. And a ring body attached to the enlarged diameter portion on the inner side in the tube axis direction than the flange portion, wherein the male side piping is inserted into the enlarged diameter portion and connected to the male side piping. It is characterized by having.

  In addition, the pipe end portion processing method of the present invention plastically processes the raw tube to form an enlarged diameter portion having an enlarged inner diameter on one end side of the raw tube, and at the outer opening end portion of the enlarged diameter portion. A pipe end machining method in which a flange portion projecting radially outward is formed, and a ring body is fixed to the outer periphery of the enlarged diameter portion by the enlarged diameter portion and the flange portion, and has a predetermined shape and size. With a female mold having a molded part and a through-hole communicating with the molded part, one end side of the raw tube penetrating the through-hole protrudes outward from the end of the molded part at the through-hole over a predetermined length. A clamping step for fixing the base pipe and a plurality of pipe cores with different outer diameters are used in order from the smallest outer diameter, and the pipe core is pressed into the base pipe from one end side of the base pipe. In the tube expansion process to expand the inner diameter of one end of the tube, and the ring body is attached to one end of the tube The flange-forming male die is pressed against the female die from one end of the tube to form a flange portion projecting radially outward at the outer opening end portion of the enlarged diameter portion, and the ring body is formed with the enlarged diameter portion and the flange portion. And a flange portion forming step of fixing to the outer periphery of the enlarged diameter portion.

  In the pipe of the present invention, the ring body is mounted on the inner side in the tube axis direction than the flange portion formed by plastic processing of the outer opening end portion of the enlarged diameter portion, so that the ring body is adjacent to the flange portion. By fixing the pipe and the male pipe with a connecting member, the strength of the connecting portion can be improved as compared with the case where there is no ring body. Even when the pipe of the present invention is produced using a thin-walled pipe, the strength of the connection portion can be increased, so that deformation of the flange portion is prevented even when a relatively large tube axial load is applied to the connection portion. be able to.

  Therefore, according to the present invention, it is possible to obtain a female-side pipe that is easy to suppress the material cost and the processing cost and that can be easily connected to the male-side pipe under high connection reliability. This pipe is obtained, for example, by processing a raw pipe according to the pipe end processing method of the present invention.

  Hereinafter, embodiments of the pipe and pipe end portion processing method of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view schematically showing an example of the piping of the present invention. The pipe 20 shown in the figure is made of copper, aluminum, stainless steel (steel) or the like and serves as a flow path for liquid such as hot water or water. The pipe 20 is connected to the other end on the one end 20a side. The enlarged diameter portion 1 has a larger inner diameter than the inner diameter. A tapered portion 10 is connected to the inner side in the tube axis direction of the diameter-expanded portion 1, and a non-expanded portion 15 is connected to the inner side of the tapered portion 10 in the tube axis direction. The enlarged diameter portion 1 and the taper portion 10 are formed by plastic processing of the raw tube, and the inner diameter ID ₁ at the enlarged diameter portion 1 is larger than the inner diameter ID ₂ at the non-expanded diameter portion 15, and the tapered portion. The inner diameter of 10 becomes smaller as it approaches the non-expanded portion 15. The inner diameter ID ₂ at the non-expanded portion 15 is the same as the inner diameter of the raw tube.

  In addition, a flange portion 1a that is formed by plastic working and projects outward in the radial direction is located at the outer opening end portion of the enlarged diameter portion 1. And the ring body 5 is mounted | worn with the axial direction inner side in the flange part 1a. The ring body 5 is disposed adjacent to the flange portion 1a and is fixed to the outer periphery of the enlarged diameter portion 1 by the enlarged diameter portion 1 and the flange portion 1a.

  In the pipe 20 having such a configuration, the enlarged diameter portion 1 can be used as a pipe joint. Other piping (male side piping) having an outer diameter equivalent to the inner diameter of the enlarged diameter portion 1 or other piping (male side piping) formed with an outer diameter equivalent to the inner diameter of the enlarged diameter portion 1 (Pipe) is inserted into the enlarged diameter part 1 from the outer opening of the enlarged diameter part 1, and both pipes are fixed by a clamp-like connecting member having an elongated hole into which the flange part 1a and the ring body 5 are inserted, for example. These two pipes can be connected to each other.

  FIG. 2 is a cross-sectional view schematically showing the pipe 20 shown in FIG. 1 and an example of the male-side pipe 30 connected to the pipe 20. 2 that are the same as those shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1 and description thereof is omitted.

  As shown in FIG. 2, when connecting the pipe 20 and the male side pipe 30, first, an O-ring or the like is provided in advance in a concave circumferential groove 23 a formed on the outer periphery of the enlarged diameter portion 23 of the male side pipe 30. And the expanded diameter portion 23 of the pipe 30 is inserted into the expanded diameter portion 1 of the pipe 20. The outer diameter of the enlarged-diameter portion 23 in the illustrated pipe 30 is equal to the inner diameter of the enlarged-diameter portion 1 in the pipe 20, and the pipe 30 has a non-inner diameter equal to the inner diameter of the non-expanded portion 15 in the pipe 20. An enlarged diameter portion 25 is provided.

  Since the inner diameter of the enlarged diameter portion 1 in the pipe 20 and the outer diameter of the enlarged diameter portion 23 in the pipe 30 are equal, when the enlarged diameter portion 23 in the pipe 30 is inserted into the enlarged diameter portion 1 in the pipe 20 These pipes 20 and 30 are connected in a watertight manner. The block body used in the connection method described in Patent Document 1 is unnecessary, and welding (brazing) of the pipes 20 and 30 can be omitted.

  Thereafter, for example, the pipes 20 and 30 are sandwiched from outside in the radial direction by a clamp-like connecting member (not shown) having a long hole into which the flange portion 1a and the ring body 5 are inserted, and the pipes 20 and 30 are connected to each other. Fix it. At this time, since the ring body 5 is adjacently disposed on the inner side in the tube axis direction of the flange portion 1a and is fixed to the outer periphery of the enlarged diameter portion 1, the pipe 20 and the male side are compared with the case where the ring body 5 is not provided. The strength of the connection portion with the pipe 30 is improved. Even when the pipe 20 is manufactured using a thin raw tube, the strength of the connection portion can be increased, and even when a relatively large tube axial load is applied to the connection portion when a liquid such as hot water or water is flowed. The deformation of the flange portion 1a can be prevented. As a result, water leakage from the connection location can be prevented.

  As described above, since the pipe 20 can be manufactured using a thin raw tube, the material cost and the processing cost can be easily suppressed. Further, even when a relatively large pipe axial load is applied to a connection portion with other pipe (male side pipe) when liquid such as hot water or water flows, the ring body 5 prevents deformation of the flange portion 1a. Therefore, it is easy to connect with the pipe on the male side under high connection reliability. The pipe on the male side connected to the pipe 20 does not have to have the enlarged diameter part 23 and the non-expanded diameter part 25 as in the pipe 30 shown in FIG. It may be that which does not have, that is, the outer diameter is constant.

  The pipe 20 exhibiting the above technical effect is obtained by processing the end portion of the raw pipe according to the pipe end portion processing method of the present invention including, for example, a clamping step, a pipe expanding step, and a flange portion forming step. Hereinafter, an example of each process will be described in detail with reference to FIGS. 3, 4-1 to 4-6, and FIG. 5.

(Clamping process)
As shown in FIG. 3, in the clamping process, the through hole 45 is penetrated by the female mold 50 having the first molding part 41 having a predetermined shape and size and the through hole 45 communicating with the first molding part 41. one end 55a side of the base pipe 55 so as to project into the first molded part 41 side over the edge of the first molded part 41 side at a predetermined length L ₁ of the through-hole 45, to secure the blank pipe 55. The female mold 50 has an upper mold 50a and a lower mold 50b. In the illustrated example, the through hole 45 communicates with the first molding part 41 via the second molding part 43 having an inner shape corresponding to the outer dimension of the taper part 10 (see FIG. 1). The length L ₂ of the through hole 45 is appropriately selected according to the length, the diameter, etc. of the element tube 55 so that the element tube 55 can be stably held.

(Pipe expansion process)
In the tube expansion step, a plurality of tube expansion cores having different outer diameters are used in order from the smaller outer diameter, the tube expansion metal core is press-fitted from one end of the element tube into the element tube, and the inner diameter at one end of the element tube To enlarge. The number of types of pipe expansion cores used in this pipe expansion process depends on the inner diameter of the base pipe and the inner diameter of the expanded diameter section 1 (see FIG. 1), in other words, the expansion ratio when the expanded diameter section 1 is formed. Depending on the case, it is appropriately selected. For example, when the base tube is a copper tube, it is relatively easy to increase the tube expansion rate to 70% or more by using three or more types of tube cores.

  FIG. 4-1 is a side view schematically showing an example of a tube expansion core used first in the tube expansion step. A tube expansion core 60 shown in the figure has a cylindrical large diameter portion 60a and a cylindrical small diameter portion 60b formed on one end side of the large diameter portion 60a, and on the distal end side of the small diameter portion 60b. Is provided with a truncated cone-shaped tip portion 60c, and a truncated cone-shaped tapered portion 60d between the small diameter portion 60b and the large diameter portion 60a. The outer diameter of the small diameter portion 60b is equal to the inner diameter of the raw tube 55 (see FIG. 3), and the outer diameter of the large diameter portion 60a is selected to a desired value.

  FIG. 4B is a cross-sectional view schematically showing a state in which the pipe expansion core 60 shown in FIG. 4A is press-fitted into the base pipe 55. As shown in the figure, when the pipe expansion core 60 is press-fitted into the base pipe 55, the inner diameter of the base pipe 55 on the one end 55 a side is expanded to the outer diameter of the large diameter portion 60 a of the pipe expansion core 60. Of the components shown in FIG. 4B and FIGS. 4-3 to 4-4 described later, those common to the components shown in FIG. 3 or FIG. The same reference numerals as those used in FIG.

  FIG. 4C is a cross-sectional view schematically showing a state in which the second tube expansion mandrel 65 is press-fitted into the base tube 55. The expansion metal core 65 shown in the figure has a cylindrical large-diameter portion 65a and a cylindrical small-diameter portion 65b formed on one end side of the large-diameter portion 65a, and on the distal end side of the small-diameter portion 65b. Has a truncated cone-shaped tip, and a truncated cone-shaped tapered portion is provided between the small diameter portion 65b and the large diameter portion 65a. The outer diameter of the small-diameter portion 65b is equal to the outer diameter of the large-diameter portion 60a (see FIG. 4-2) in the first tube expansion core 60, and the outer diameter of the large-diameter portion 65a in the tube expansion core 65 is desired. Is selected. By press-fitting the tube expansion mandrel 65 into the element tube 55, the inner diameter of the element tube 55 on the one end 55 a side is expanded to the outer diameter of the large diameter portion 65 a of the tube expansion mandrel 65.

  FIG. 4-4 is a cross-sectional view schematically showing a state in which the third expansion core 70 is press-fitted into the base tube 55. A tube expansion mandrel 70 shown in the figure has a cylindrical large diameter portion 70a and a cylindrical small diameter portion 70b formed on one end side of the large diameter portion 70a. Is provided with a truncated cone-shaped tip portion, and a truncated cone-shaped tapered portion between the small diameter portion 70b and the large diameter portion 70a. The outer diameter of the small-diameter portion 70b is equal to the outer diameter of the large-diameter portion 65a (see FIG. 4-3) in the second core expansion metal 65, and the outer diameter of the large-diameter portion 70a in the tube expansion core 70 is desired. Is selected. By press-fitting the pipe core 70 into the base pipe 55, the inner diameter of the base pipe 55 on the one end 55 a side is expanded to the outer diameter of the large diameter portion 70 b of the pipe core 70.

  4-5 is a cross-sectional view schematically showing a state in which the ring body 5 is attached to the raw tube 55. FIG. The inner diameter of the ring body 5 shown in the figure is equivalent to the outer diameter of the enlarged diameter portion 1 (see FIG. 1) in the pipe 20.

  FIG. 4-6 is a cross-sectional view schematically showing a state in which the last pipe expansion core 75 is press-fitted into the base pipe 55. A tube expansion mandrel 75 shown in the figure has a cylindrical large-diameter portion 75a and a truncated cone-shaped tip portion 75b formed on one end side of the large-diameter portion 75a. A larger-diameter pressing portion 75c is provided on the end side. The outer dimension of the tip 75b is equivalent to the inner dimension of the tapered part 10 (see FIG. 1) in the pipe 20, and the outer diameter of the large diameter part 75a is equivalent to the inner diameter of the enlarged part 1 (see FIG. 1). is there.

  The combined length of the large diameter portion 75a and the tip portion 75b of the pipe expansion mandrel 75 is such that when the tapered portion 10 is formed on the base tube 55 by the tip portion 75b, the element tube 55 is connected to the tube axis by the pressing portion 75c. It is selected to be pressed in the direction and compressed by a predetermined length. As a result, when the expansion metal core 75 is press-fitted into the base tube 55, the expanded diameter portion 1 and the tapered portion 10 in the pipe 20 are formed, and the outer periphery of the expanded diameter portion 1 is radially outside the ring body 5. The ring body 5 rises outward and is temporarily fixed to the enlarged diameter portion 1. In addition, said pipe expansion metal core 75 which has the press part 75c can also be considered as a male type | mold.

(Flange forming process)
In the flange portion forming step, the flange portion forming male die is pressed from one end side of the raw tube to the female die in a state where the ring body is attached to the one end side of the raw tube, and the diameter is increased to the outer opening end portion of the enlarged diameter portion. A flange portion protruding outward in the direction is formed, and the ring body is fixed to the outer periphery of the enlarged diameter portion by the enlarged diameter portion and the flange portion. In this example, since the ring body is already attached to the base pipe in the pipe expanding step, the ring body is not attached to the enlarged diameter portion in the flange portion forming step.

  FIG. 5 is a cross-sectional view schematically showing an example of a male part for forming a flange part used for forming the flange part and a flange part formed on the raw pipe using the male mold. Among the constituent elements shown in the figure, those common to the constituent elements shown in FIG. 4-6 are designated by the same reference numerals as those used in FIG.

  The male part 80 for flange part formation shown in FIG. 5 has the insertion part 77 inserted in the raw tube 55, and the molding part 78 which forms the flange part 1a in the one end 55a side of the raw pipe 55. The outer shape and size of the insertion portion 77 are the shape and size of the inner shape of the tapered portion 10 in the pipe 20 and the inner shape of the enlarged diameter portion 1 (see FIG. 1). Moreover, the molding part 78 has the recessed part 78a which prescribes | regulates the external shape of the flange part 1a. The depth of the recess 78a along the tube axis of the element tube 55 is such that when the flange forming male die 80 is pressed against the female die 50 via the ring body 5, the one end 55a side of the element tube 55 is plastically deformed. The desired flange portion 1a is selected. The concave portion 78a defines the thickness and height of the flange portion 1a to be formed.

  Therefore, the desired flange portion 1a can be formed by inserting the flange portion forming male die 80 into the female die 50 via the ring body 5 after inserting the one end 55a of the element tube 55 into the concave portion 78a. At this time, along with the formation of the flange portion 1 a, the flange portion 1 a is formed so that the outer periphery of the element tube 55 further swells outward in the radial direction outside the ring body 5, and the flange portion 1 a is formed on the ring body 5. Because of the pressure contact, the ring body 5 is fixed to the outer periphery of the enlarged diameter portion 1 by the enlarged diameter portion 1 and the flange portion 1a. Thereafter, by removing the female mold 50 and the flange-forming male mold 80, the pipe 20 (see FIG. 1) is obtained.

Embodiment 2. FIG.
In the pipe end portion processing method described in the first embodiment, the diameter expanding portion is formed in the tube expanding step, and the flange portion is formed and the ring body is fixed in the flange portion forming step. In the process, the enlarged diameter portion and the flange portion can be formed and the ring body can be fixed simultaneously.

  In this case, first, after performing the clamping process described in the first embodiment, the steps shown in FIG. 4-5 of the tube expansion process described in the first embodiment are performed, and the ring body 5 is formed into the base tube 55. Installing. Thereafter, the flange portion forming step described in Embodiment 1 with reference to FIG. 5 is performed. That is, one end 55a of the element tube 55 is inserted into the recess 78a of the flange part forming male die 80, and the flange part forming male die 80 is brought into pressure contact with the female die 50 via the ring body 5, so At the same time that the enlarged diameter portion 1 and the flange portion 1a are formed on the one end 55a side, the ring body 5 is fixed to the outer periphery of the enlarged diameter portion 1 by the enlarged diameter portion 1 and the flange portion 1a. If the end portion of the element pipe 55 is processed by this method, the pipe 20 can be obtained with a smaller number of man-hours and the number of molds (core expansion cores), and as a result, the manufacturing cost can be reduced.

Embodiment 3 FIG.
Each of the tube end processing methods described in the first and second embodiments is a method that does not particularly control the temperature of the female mold 50 (see, for example, FIG. 4B). If the one end 55a side of 55 is processed, the work hardening of the raw tube 55 can be suppressed, and as a result, the expanded diameter portion 1 (see FIG. 1) having a large expansion ratio (for example, 70% or more) can be formed more stably. Easy to do.

  For example, when the base tube 55 is a copper tube, work hardening can be suppressed by heating the female die 50 to a constant temperature of about 100 to 200 ° C. The female mold 50 can be heated using, for example, a heater and a temperature controller. The heating of the female die 50 may be performed only in both the tube expansion step and the flange portion forming step, but it is preferable to perform the heating through all the steps including the clamping step.

Embodiment 4 FIG.
In the pipe end portion processing method described in the first embodiment, the end face shape of the raw pipe 55 is not particularly managed and plastic processing is performed as it is. However, the sub-clamp process is performed between the clamp process and the pipe expansion process. If the end face shaping step is further included, the burr and the like at the time of cutting remaining at the one end 55a of the base tube 55 can be shaped, and as a result, the diameter-expanded portion 1 having a large pipe expansion rate (for example, 70% or more) (see FIG. 1) is more easily formed.

  The pipe end portion processing method for obtaining the technical effect described above includes a clamping step, a sub-clamping step, an end face shaping step, a pipe expanding step, and a flange portion forming step. Among them, the clamping process, the pipe expanding process, and the flange part forming process are performed in the same manner as in the pipe end processing method described in the first embodiment, and therefore illustration and description thereof are omitted here. Hereinafter, the sub-clamping process and the end face shaping process will be described with reference to FIGS.

(Sub clamp process)
In the sub-clamping process, the base tube is fixed by the sub-female die having only the through hole in a state in which one end side of the sub-tube protrudes outward from the end of the sub-female for a certain length. At this time, the blank tube is fixed by the female mold used in the clamping process and the sub female mold.

  FIG. 6 is a cross-sectional view schematically showing an example of a sub-female mold used in the sub-clamping process and a state in which the raw tube is fixed by the sub-female mold. Among the constituent elements shown in the figure, those common to the constituent elements shown in FIG. 3 used in the description of the clamping step are denoted by the same reference numerals as those used in FIG.

The sub-female mold 90 shown in the figure includes an upper mold 90a and a lower mold 90b, and has only a through hole 85 as a molding part. The diameter of the through hole 85 is equal to the outer diameter of the raw tube 55. The secondary female mold 90 has the element tube 55 sandwiched from above and below from the end of the female mold 50 over a predetermined length L _3, and the end 55 a side of the element pipe 55 that penetrates the through hole 85 is predetermined from the end of the auxiliary female mold 90. The element tube 55 is fixed in a state of protruding over the length L ₄ . The length L ₃ of the through-hole 85 is appropriately selected according to the length, diameter, etc. of the element tube 55 so that the element tube 55 can be stably held.

(End face shaping process)
In the end face forming step, the end face shape male shape is pressed from one end side of the element pipe to the end portion of the element pipe protruding from the sub female mold to shape the end face shape of the element pipe. FIG. 7 is a cross-sectional view schematically showing an example of a male mold for shaping an end face and a state in which the male mold is pressed against an element tube. Among the constituent elements shown in the figure, those common to the constituent elements shown in FIG. 6 are given the same reference numerals as those used in FIG.

  The male mold 95 for end face shaping shown in FIG. 7 has a truncated cone-shaped tip portion 95a formed on one end side, and a central portion side of the end face shaping male die 95 with respect to the tip portion 95a connected to the tip portion 95a. A large-diameter portion 95b formed on the large-diameter portion, and a larger-diameter pressing portion 95c formed continuously to the large-diameter portion 95b. The outer dimension of the tip 95a is less than the inner dimension of the blank 55, the outer diameter of the large diameter portion 95b is equal to the inner diameter of the blank 55, and the outer diameter of the pressing portion 95c is greater than the outer diameter of the blank 55. Is also big.

  Therefore, the end face of the end 55a of the pipe 55 is inserted by inserting the tip 95a and the large-diameter part 95b of the male 95 for end face shaping into the blank 55 and pressing the side surface of the pressing portion 95c against the end of the blank 55. The shape can be shaped. Thereafter, the secondary female mold 90 and the end face shaping male mold 95 are removed, and a pipe expanding step (see FIGS. 4-1 to 4-6) and a flange portion forming step (see FIG. 5) are performed to form the female die 50 and the flange portion. By removing the male mold 80, the pipe 20 (see FIG. 1) is obtained.

Embodiment 5 FIG.
In the pipe end part processing method described in the fourth embodiment, the clamping process, the sub-clamping process, the end face shaping process, the pipe expanding process, and the flange forming process are performed in this order. Also in the case of performing the steps, as in the pipe end portion processing method described in the second embodiment, the formation of the enlarged diameter portion and the flange portion and the fixing of the ring body can be performed simultaneously in the flange portion forming step. If the end portion of the raw pipe is processed by this method, the pipe 20 (see FIG. 1) can be obtained with a smaller number of man-hours and the number of molds (core expansion cores), and as a result, the manufacturing cost is reduced. be able to.

Embodiment 6 FIG.
In the pipe end processing method described in the fourth embodiment, the clamping process, the sub-clamping process, the end face shaping process, the pipe expanding process, and the flange forming process are performed in this order. Can be performed simultaneously. In this case, the element tube 55 is sandwiched and fixed simultaneously by the female mold 50 and the sub female mold 90 shown in FIG. If the base pipe 55 is fixed in this manner, the pipe 20 (see FIG. 1) can be obtained with less man-hours, and as a result, the manufacturing cost can be reduced.

Embodiment 7 FIG.
Each of the pipe end processing methods described in the fourth, fifth, and sixth embodiments is a method that does not particularly control the temperature of the female die 50 and the sub female die 90 (see FIG. 6). If the one end 55a side of the element tube 55 is processed while heating the female die 50 and the sub female die 90 in the same manner as in the described tube end portion processing method, the work hardening of the element tube 55 can be suppressed. As a result, it becomes easy to more stably form the enlarged diameter portion 1 (see FIG. 1) having a large tube expansion rate (for example, 70% or more). Although it is possible to make the heating temperature of the sub female mold 90 different from the heating temperature of the female mold 50, it is easier to heat them so that the female mold 50 and the sub female mold 90 have the same temperature. . Although the sub female mold 90 may be heated only in the end face forming step, it is preferable to perform it in both the sub clamp step and the end face shaping step.

Embodiment 8 FIG.
FIG. 8 is a cross-sectional view schematically showing another example of the pipe of the present invention. The piping 120 shown in the figure is the piping 20 described in the first embodiment except that the flange portion 1b is formed by directing the outer opening end of the enlarged diameter portion 1 radially outward by plastic working. (See FIG. 1). Among the constituent elements shown in FIG. 8, those common to the constituent elements shown in FIG. 1 are given the same reference numerals as those used in FIG. 1 and description thereof is omitted.

  In the pipe 120 having such a configuration, the material cost and the processing cost can be easily suppressed for the same reason as in the pipe 20 described in the first embodiment. Moreover, since the deformation | transformation of the flange part 1b is prevented by the ring body 5, it is easy to connect with the piping of the male side under high connection reliability. Furthermore, since there is no uneven surface in the vicinity of the outer opening end 120a of the enlarged diameter portion 1, when another pipe (male side pipe) is inserted into the enlarged diameter portion 1, the O attached to the male side pipe. It is possible to prevent a sealing material such as a ring from being damaged. In connecting the piping 120 and other piping, the block body used by the connection method described in the above-mentioned patent document 1 is unnecessary, and welding (brazing) of these two piping can also be omitted. .

  The pipe 120 that exhibits the above-described technical effect can be obtained by processing the raw pipe by the same pipe end processing method as that in the pipe end processing method described in the first to seventh embodiments. Since each process performed when manufacturing the pipe 120 is performed in the same manner as in the pipe end processing method described in the first to seventh embodiments, illustration and description thereof are omitted here.

  As mentioned above, although the embodiment and the pipe end portion processing method of the present invention have been described, as described above, the present invention is not limited to the above-described embodiment. For example, it is not an essential requirement to fix the ring body to the outer periphery of the enlarged diameter portion by the enlarged diameter portion and the flange portion, and the ring body is merely a reinforcement of the flange portion. It may be slidably mounted. When the ring body is not fixed to the enlarged diameter portion, when connecting the pipe of the present invention and another pipe (male side pipe), the ring body is moved to be adjacent to the flange portion, and in this state, The pipe and the male pipe are fixed with a connection member, for example, a clamp-shaped connection member having a long hole into which the ring body and the flange portion are inserted.

  Also, if the pipe expansion ratio at the expanded diameter portion of the pipe is low, the length of the tapered portion (length in the tube axis direction) interposed between the expanded diameter portion and the non-expanded diameter portion is zero, that is, the tapered portion is the tube. It may be formed perpendicular to the axial direction. About the piping and pipe end part processing method of this invention, a various deformation | transformation, modification, combination, etc. are possible besides what was mentioned above.

  The pipe of the present invention is useful for forming a flow path in various devices and structures in which liquids such as water and hot water must flow down.

It is sectional drawing which shows roughly an example of piping of this invention. It is sectional drawing which shows roughly the piping shown in FIG. 1, and an example of the other piping connected to this piping. An example of a female mold used in a clamping process performed when a pipe shown in FIG. 1 is obtained by processing a pipe by the pipe end machining method of the present invention, and a state in which the pipe is fixed by the female mold. It is sectional drawing shown roughly. It is a side view which shows roughly an example of the core metal for pipe expansion used at the time of the pipe expansion process performed when processing a raw pipe by the pipe end part processing method of this invention, and obtaining the piping shown in FIG. It is sectional drawing which shows schematically the state which press-fitted the mandrel for tube expansion shown in FIG. Sectional drawing which shows roughly the state which press-fitted the 2nd pipe expansion metal core in the pipe expansion process performed when processing a pipe | tube by the pipe | tube end part processing method of this invention, and obtaining the piping shown in FIG. It is. Sectional drawing which shows schematically the state which press-fitted the 3rd pipe expansion metal core in the pipe expansion process performed when processing a pipe | tube end by the pipe | tube end part processing method of this invention, and obtaining the piping shown in FIG. It is. FIG. 2 is a cross-sectional view schematically showing a state in which a ring body is attached to a raw pipe in a pipe expanding process performed when the raw pipe is processed by the pipe end processing method of the present invention to obtain the pipe shown in FIG. 1. FIG. 3 is a cross-sectional view schematically showing a state in which the final expansion core is press-fitted into the raw pipe in the pipe expansion process performed when the raw pipe is processed by the pipe end processing method of the present invention to obtain the pipe shown in FIG. 1. is there. An example of a male part for forming a flange part used for forming a flange part in the flange part forming process performed when the raw pipe is processed by the pipe end part processing method of the present invention to obtain the pipe shown in FIG. It is sectional drawing which shows roughly the flange part formed in the element pipe using the type | mold. An example of a sub-female mold used in a sub-clamping step performed when a pipe shown in FIG. 1 is obtained by processing a pipe by the pipe end processing method of the present invention, and the pipe is fixed by the sub-female mold. It is sectional drawing which shows a state roughly. An example of a male mold for end face shaping used in shaping an end face in an end face shaping process performed when the pipe shown in FIG. It is sectional drawing which shows schematically the state press-contacted to the pipe | tube. It is sectional drawing which shows the other example of piping of this invention roughly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Expanded part 1a, 1b Flange part 5 Ring body 10 Taper part 15 Non-expanded part 20, 120 Pipe 20a, 120a One end of pipe 23 Expanded part of other pipe 25 Non-expanded part of other pipe 27 Sealing material 30 Other piping 41 1st molding part 43 2nd molding part 45 Through-hole 50 Female type | mold 55 Elementary pipe 55a One end of a raw pipe 60 The core metal for expansion first used 60a Large diameter part 60b Small diameter part 60c Tip part 60d Taper part 65 Secondly used expansion core 65a Large diameter portion 65b Small diameter portion 70 Third expansion core 70a Large diameter portion 70b Small diameter portion 75 Lastly used expansion core metal 75a Large diameter portion 75b Small diameter portion 75c Pressing portion 77 Male insertion portion for forming flange portion 78 Male molding portion for forming flange portion 78a Male concave portion for forming flange portion 80 Male for forming flange portion 85 secondary female through hole 90 sub female 95 ends shaping female 95a end shaping female tip 95b end shaping female large-diameter portion 95c end pressing part of the shaping female

Claims (5)

A diameter-enlarged portion whose inner diameter is enlarged by plastic working is provided on one end side, and a flange portion formed by plastic working of an outer opening end portion of the diameter-enlarged portion and projecting radially outward is provided. A male-side pipe inserted into the male-side pipe and connected to the male-side pipe,
A pipe having a ring body attached to the enlarged diameter portion on the inner side in the tube axis direction than the flange portion.   The pipe according to claim 1, wherein the ring body is fixed to an outer periphery of the enlarged diameter portion by the enlarged diameter portion and the flange portion. The base pipe is plastically processed to form a diameter-expanded portion with an enlarged inner diameter at one end of the base tube and to form a flange portion projecting radially outward at the outer opening end of the diameter-expanded portion, A pipe end processing method for fixing a ring body to the outer periphery of the enlarged diameter portion by the enlarged diameter portion and the flange portion,
A female mold having a molded part of a predetermined shape and size and a through-hole communicating with the molded part, so that one end side of the element pipe penetrating the through-hole is predetermined from the end of the through-hole on the molded part side A clamping step of fixing the raw tube in a state of protruding outward over a length;
A plurality of tube cores with different outer diameters are used in order from the smallest outer diameter, and the tube core is pressed into the tube from one end side of the tube, thereby reducing the inner diameter of one end of the tube. Expanding pipe expansion process;
With the ring body attached to one end of the element tube, the flange-forming male die is pressed from the one end side of the element tube to the female die, and radially outward to the outer opening end of the enlarged diameter portion. A flange portion forming step of forming an overhanging flange portion and fixing the ring body to an outer periphery of the enlarged diameter portion by the enlarged diameter portion and the flange portion;
A method of processing a tube end portion, comprising: Between the clamping step and the tube expansion step,
A sub-clamping step of fixing the base tube in a state where one end side of the base tube protrudes outward from the end of the secondary female die over a certain length by a sub-female die having only a through hole;
An end face shaping step of shaping the end face shape of the element pipe by pressing the end face shaping male mold from one end side of the element pipe to the end of the element pipe protruding from the sub-female mold;
The tube end portion processing method according to claim 3, further comprising:   5. The pipe end processing method according to claim 3, wherein at least the tube expansion step and the flange portion forming step are performed in a state in which the female mold is heated.

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