JP6630083B2 - Connection method and connection structure of pipe and caulked joint - Google Patents

Description

  The present invention relates to a connection method and a connection structure of a pipe and a caulking joint for connecting metal pipes.

  There are various types of pipe joints used for connecting the pipes, such as a threaded type, a welded type, and a type using a shape memory alloy, and they are used properly according to applications.

  A refrigeration cycle is formed by connecting each device such as an evaporator or condenser, expansion valve or compressor such as a packaged air conditioner with piping, and the evaporator or condenser is used as a heat exchanger with conditioned air. In this type of air conditioning equipment, a refrigerant such as a fluorocarbon-based refrigerant is circulated and circulated inside a pipe while causing a phase transition between gas and liquid. Pipes (refrigerant pipes) used in such air conditioning equipment are required to have perfect airtightness, as well as chemical and physical properties such as corrosion resistance, pressure resistance, and ease of processing, and pressure loss of the refrigerant. Various characteristics are required, such as a mechanical shape that can be made as small as possible. Conventionally, copper (particularly, high-purity phosphorous deoxidized copper) is mainly used as a material capable of satisfying these characteristics, and a connection between a copper pipe and a pipe joint (or between copper pipes) is made of brazing material. Is generally performed by brazing (brazing) for joining metals by melting. However, in recent years, as the price of copper, which is a raw material for copper tubes, has risen, the use of aluminum, which is a cheaper material, instead of copper is being studied. In addition, brazing is a craftsmanship operation that requires advanced skills, and construction labor costs are high for skilled craftsmen. Have been.

  By the way, when brazing a copper tube, phosphor copper brazing or silver brazing is often used as a filler material. Phosphor copper braze or silver braze easily penetrates into narrow gaps during bonding, is less likely to have defects such as voids, has higher corrosion resistance, and has a melting point compared to copper, the base metal. It is suitable for brazing copper tubes in that it is sufficiently low. Here, in order to allow the filler material to penetrate between the pipe joint and the pipe during brazing, it is necessary to keep the temperature of the filler material somewhat higher than the melting point. Is 1,085 ° C., whereas the melting point of phosphor copper brazing or silver brazing is about 600 ° C. to 800 ° C., which is sufficiently lower than that of copper as a base material, so that the brazing temperature is 760 ° C. to 850 ° C. Even if the temperature is kept higher than the melting point of ℃, there is no risk of melting of copper as a base material. On the other hand, when aluminum is used as the material of the piping, the melting point of aluminum as a base material is as low as 660 ° C., whereas the melting point of aluminum brazing filler metal is about 450 ° C. to 590 ° C. Is near. For this reason, if the temperature is raised to infiltrate the molten aluminum braze, the base material may be melted together, and it is difficult to braze the pipe so as not to make a hole. Such a problem can be avoided by using a dry mechanical joint that does not require welding for connection.

  As a type of mechanical joint, there is known an air-conditioning system that uses water (cold water) as a heat medium, as a type of mechanical joint that presses metal to deform (cauld) and press-fits it to pipes. , Are partially used for connecting water pipes for conveying water. In the case of such a water pipe, the working pressure is usually 0.98 MPa or less, which is a range in which a carbon steel pipe for the pipe can be used. Further, even if it is higher than this, it is within the range of 1.96 MPa or less.

  As compared with the case of such a water pipe, in the case of the refrigerant pipe of the air conditioner constituting the refrigeration cycle as described above, the working pressure is higher and is about 5 to 10 MPa. If a joint is to be used for this type of refrigerant pipe, higher performance is required for the joint. That is, since it is required to realize complete airtightness under high pressure, it is necessary to connect the pipe and the pipe joint with a stronger force (caulking force). As a caulking joint capable of meeting such demands, there is a caulking joint of a type in which an insert member lining a pipe is inserted into the pipe and the insert member supports the pipe from the inside to cope with a strong caulking force.

  8 and 9 show an example of such a caulking joint, in which an insert member 2 inserted into an end of a metal pipe 1 through which a fluid flows to support the pipe 1 from the inside, an end of the pipe 1 A joint member 3 which is a main part of a caulking joint for fitting the plurality of tubes 1 to each other so as to cover the outer periphery of the tube 1 from outside, and a nut 4 for crimping the joint member 3 to the tube 1. Become. The insert member 2, the joint member 3, and the nut 4 have various sizes and shapes, and a member corresponding to the diameter, shape, and material of the pipe 1 to be connected can be selected and used.

  As shown in FIGS. 8 (b) and 9 (b), the insert member 2 has a substantially cylindrical main body 21 having a uniform circular cross section, and a flange 22 protruding from one end of the outer periphery of the main body 21. A metal member having a size such that the outer diameter of the main body 21 substantially matches the inner diameter of the tube 1 is used. As a material of the insert member 2, for example, high-strength steel is used. The outer periphery of the end of the main body 21 on the side not provided with the flange 22 is appropriately chamfered so that it can be easily inserted into the pipe 1 in a connection step described later.

  As shown in FIGS. 8C and 9C, the joint member 3 communicates with the pipe 1 and connects to the pipe 1 at both ends of a pipe body 30 that forms a pipe connecting the plurality of pipes 1. It is a metal member provided with a pipe connection part 34 for performing the connection. The pipe connection portion 34 includes a substantially cylindrical sleeve 31 and a fulcrum portion 32 projecting from the outer periphery of the base of the sleeve 31. A step 33 is provided so as to overhang. A tapered portion 31a is formed on the outer peripheral surface of the sleeve 31 over a predetermined range from the distal end, and the sleeve 31 is substantially in a predetermined range (a portion other than the tapered portion 31a) on the base side (the fulcrum portion 32 side). Although it has a constant outer diameter, the outer diameter of the tapered portion 31a decreases from the base side to the tip starting from the base end of the tapered portion 31a. The sleeve 31, the fulcrum part 32 and the step part 33 form a pipe connection part 34. In the example shown in FIGS. 8C and 9C, a short cylindrical tube portion 30 is provided with a tube connection portion 34 at one end and another tube connection portion 34 is provided at the other end so as to be symmetrical with the tube connection portion 34. A pipe connection 34 is provided. In addition, as the joint member 3, in addition to the above, a T-shaped or Y-shaped pipe body provided with three pipe connections, or an L-shaped pipe body provided with two pipe connections. And those having various shapes, such as one in which two pipe connecting portions are connected by a tube portion of a flexible pipe.

  For connection with the tube 1, a joint member 3 having a size in which the inner diameter of the sleeve 31 substantially matches the outer diameter of the tube 1 is used. As a material of the joint member 3, for example, steel having a certain degree of malleability is used.

  The nut 4 is a substantially cylindrical metal member as shown in FIGS. 8 (d) and 9 (d), and has a tapered portion 4a formed at one end of the inner peripheral surface thereof from the end to a predetermined range. ing. The inner diameter of the nut 4 has a substantially constant diameter in a portion other than the tapered portion 4a, but in the tapered portion 4a, the inner diameter increases toward the tip. The outer peripheral surface of the nut 4 is tapered at the end on the side where the tapered portion 4a is formed, and the tapered portion 4a formed on the inner peripheral surface is marked with the tapered processing as a mark. Direction can be determined from the outside. At the time of connection, at least part of the inner diameter of the inner peripheral surface is smaller than at least part of the outer diameter of the outer peripheral surface of the sleeve 31 of the joint member 3. More specifically, it is desirable to use a joint member 3 whose inner diameter is slightly smaller than the outer diameter of a portion other than the tapered portion 31 a of the sleeve 31 of the joint member 3. The outer diameter of the tip portion (the portion having the largest inner diameter) is larger than the outer diameter of the tip portion (the portion having the smallest outer diameter) of the tapered portion 31a of the sleeve 31 and smaller than the outer diameter of the fulcrum portion 32. Is more desirable. The axial length of the nut 4 is set to be substantially equal to the axial length of the sleeve 31 of the joint member 3 or less than the axial length of the sleeve 31. As a material of the nut 4, for example, high-strength steel is used.

  A caulking joint including the insert member 2, the joint member 3, and the nut 4 is attached to an end of the pipe 1, and the caulking joint is connected to the pipe 1 by a special caulking joint tool 5.

  As shown in FIG. 10 (a), the swaging joint tool 5 includes an electro-hydraulic vise 51 having a trigger-shaped switch in the handle 50, and the vise 51 includes a first pedestal 52 and a second pedestal 52. A pedestal 53 is provided. In the connection operation, as shown in FIG. 10B, a first jig 54 is attached to a first pedestal 52 and a second jig 55 is attached to a second pedestal 53 for use. The vise unit 51 operates a hydraulic mechanism (not shown) in accordance with the input to the switch, and applies a force to the first pedestal 52 and the second pedestal 53 in a direction to approach each other.

  As shown in FIG. 11A, the first jig 54 includes a leg portion 56 connected to the first pedestal 52 (see FIG. 10B) and a clamp portion 57 for supporting the joint member 3. The clamp portion 57 protrudes from a substantially semi-cylindrical first support groove 58 on which the joint member 3 is placed, and an inner periphery on one end side of the first support groove 58 to lock the fulcrum portion 32 of the joint member 3. The first locking flange 59 is provided. The first locking flange 59 is formed on one end side of the first support groove 58, and is formed such that one end surface of the first locking flange 59 is continuous with one end surface of the clamp portion 57. The legs 56 are two protrusions provided on the surface of the clamp 57 opposite to the first support groove 58, and sandwich the groove provided on the first pedestal 52 as shown in FIG. It fits so that it fits.

  As shown in FIG. 11B, the second jig 55 includes a leg 60 connected to the second pedestal 53 (see FIG. 10B) and a clamp 61 that supports the pipe 1. The clamp portion 61 has a substantially semi-cylindrical second support groove 62 on which the tube 1 is placed, and a second locking flange 63 which protrudes from the inner periphery of the second support groove 62 and locks the nut 4. Is provided. The second locking flange 63 is formed on one end side of the second support groove 62, and is formed such that one end surface of the second locking flange 63 is continuous with one end surface of the clamp portion 61. The leg portions 60 are two protrusions provided on the surface of the clamp portion 61 opposite to the second support groove 62, and sandwich the groove provided on the second pedestal 53 as shown in FIG. It fits so that it fits.

  The first jig 54 and the second jig 55 each have various sizes according to the size and shape of the joint member 3, and suitable ones can be selected and used. As the first jig 54, the inner diameter of the first support groove 58 is equal to or larger than the outer diameter of the fulcrum 32 of the joint member 3 and equal to or larger than the outer diameter of the nut 4. A member having a size smaller than the outer diameter of the fulcrum portion 32 of the member 3 and larger than the outer diameter of the tubular body portion 30 is used. As the second jig 55, one having an inner diameter of the second locking flange 63 smaller than the outer diameter of the nut 4 and larger than the outer diameter of the pipe 1 is used.

  The procedure for connecting the caulked joint by the caulking joint tool 5 and the first jig 54 and the second jig 55 will be described with reference to FIG. 12 and FIGS. FIG. 12 is a flowchart illustrating a method of connecting a pipe and a swaged joint, and FIGS. 13 to 21 are diagrams illustrating steps in a connection process of a pipe and a swaged joint.

  First, as step S1 (see FIG. 12), the insert member 2 is inserted into the end of the pipe 1. Prior to this, if necessary, a tool such as a reamer (not shown) is used to insert the insert member 2 inside the end of the pipe 1. Deburr. This is because burrs are often formed at the end of the tube 1 when the tube 1 is cut, and the burrs may hinder the insertion member 2 without being inserted.

  After the deburring, the main body 21 of the insert member 2 is inserted into the end of the tube 1 as shown in FIG. As described above, the outer diameter of the main body 21 is substantially equal to the inner diameter of the tube 1 and the flange 22 projects from one end of the outer periphery of the main body 21, so that the flange 22 is positioned. The insert member 2 stops when the main body 21 is inserted to the position of the flange 22.

  Next, as step S2, marking of the insertion margin is performed. As shown in FIG. 14, the end of the tube 1 into which the insert member 2 has been inserted is temporarily inserted into the opening of the sleeve 31 of the joint member 3. At this time, as described above, since the inner diameter of the sleeve 31 is substantially equal to the outer diameter of the tube 1, and the base 31 side of the inner surface of the sleeve 31 is provided with the step portion 33 so as to project toward the inner circumference, The step portion 33 is positioned, and the end of the tube 1 into which the insert member 2 is inserted stops when the tube 1 is inserted to the position of the step portion 33. Then, as shown in FIG. 14B, the end of the tube 1 into which the insert member 2 has been inserted is in a state of being covered by the sleeve 31 of the joint member 3 for a predetermined length L (hereinafter, the insert member 2 will be referred to as the insert member 2). When the inserted tube 1 is inserted into the sleeve 31, the portion covered by the sleeve 31 is referred to as the "insertion margin" of the tube 1.) In this state, as shown in FIG. 14A, a mark 11 is attached to a position corresponding to the end of the sleeve 31 in the tube 1 with an oil-based pen or the like, and then the sleeve 31 is once removed. As shown in FIG. 15, the range of the length L from the tip of the tube 1 to the position of the mark 11 is the insertion allowance of the tube 1. Can be visually recognized.

  When the pipe 1 is handled at a construction site or the like, usually, a pipe cut out from a fixed-length pipe and having an appropriate length according to the dimensions of the site is often used. In this case, the above-described marking operation must be performed on site.

  Next, setting to the swaging joint tool 5 is performed as step S3. As shown in FIG. 16, the end of the tube 1 into which the insert member 2 has been inserted is passed through the nut 4 and then inserted again into the opening of the sleeve 31 of the joint member 3. At this time, the nut 4 is passed through the pipe 1 such that the tapered portion 4a side faces the joint member 3 side. Here, the outer peripheral surface of the nut 4 is tapered at the end on the side where the tapered portion 4a is formed. Can be. Subsequently, the end of the tube 1 is inserted into the sleeve 31. At this time, if an adhesive (not shown) is applied to the outer peripheral surface of the insertion margin of the tube 1 (see FIG. 15) and then inserted, the tube 1 is made of metal. The wettability of the joint member 1 and the joint member 3 is enhanced to assist the joining, and the connection becomes stronger.

  After the caulking joint (the insert member 2, the joint member 3, and the nut 4) is attached to the pipe 1, the pipe 1 and the caulking joint are set on the caulking joint tool 5.

  First, the leg 56 of the first jig 54 is attached to the first pedestal 52 and the leg 60 of the second jig 55 is attached to the second pedestal 53 (see FIG. 10B). As described above, as the first jig 54 and the second jig 55, one having a size suitable for a caulking joint is selected.

  Next, as shown in FIG. 17, the pipe 1 to which the swage joint is attached is disposed on the first jig 54 and the second jig 55 mounted on the swage joint tool 5. The tube 1 is placed in the second support groove 62 of the second jig 55, and the nut 4 is provided between the second locking flange 63 of the second jig 55 and the first locking flange 59 of the first jig 54. The joint member 3 is arranged such that the tube portion 30 is positioned on the first locking flange 59 and the fulcrum portion 32 on the side connected to the pipe 1 is positioned immediately adjacent to the first locking flange 59. To be arranged. At this point, the swaged joint is in a state where it can be freely inserted into and removed from the pipe 1.

  In this state, the vise part 51 of the caulking joint tool 5 is operated as step S4. The first pedestal 52 to which the first jig 54 is attached and the second pedestal 53 to which the second jig 55 is attached are operated so as to approach each other. The surface on the side facing the jig 55 contacts the fulcrum 32 of the joint member 3, and the second locking flange 63 of the second jig 55 contacts the end of the nut 4. Further, with the operation of the first jig 54 and the second jig 55, the end of the nut 4 on the first jig 54 side is pressed against the tip of the sleeve 31 of the joint member 3.

  Here, as described above, the nut 4 is in a state in which a part of the tapered portion 4 a is externally fitted to a part of the distal end side of the tapered portion 31 a of the sleeve 31. As the nut 4, the inner diameter of the tip side (the portion having the largest inner diameter) of the tapered portion 4 a formed on the inner peripheral surface is part of the sleeve 31 (the portion other than the tapered portion 31 a and the base of the tapered portion 31 a). Since the outer diameter of the sleeve 31 is smaller than the outer diameter of the (closer part), the sleeve 31 does not fit into the nut 4 any more as long as the nut 4 and the joint member 3 maintain their original shapes. The nut 4 temporarily stops in a state where only a part of the nut 4 is externally fitted to the sleeve 31. However, due to the subsequent operation of the vise part 51, the sleeve 31 of the joint member 3 made of a malleable material is pressed against the nut 4 having high strength by a strong force in the axial direction. While deforming (caulking) by receiving a force directed inward in the radial direction from the inner peripheral surface, it sinks inside the nut 4. That is, the nut 4 and the joint member 3 partially overlap each other while forming a taper (taper portion 4a and taper portion 31a) at a part of their inner peripheral surface or outer peripheral surface. By pressing in the direction, a large caulking force is generated in the radial direction.

  As the sleeve 31 goes deeper into the nut 4, the deformation of the sleeve 31 increases, the caulking force as a repulsive force against the deformation increases, and the repelling force is transmitted to the vise 51 as a torque. As shown in FIG. 18, when the end of the nut 4 on the first jig 54 side reaches the vicinity of the fulcrum 32 of the joint member 3 and the torque due to the increased repulsive force reaches a predetermined value, the vise part 51 does not show it. The torque release mechanism operates to release the pressure of the electric hydraulic unit, and the vice unit 51 stops the axial compression operation. After the stop, the first pedestal 52 and the second pedestal 53 are further operated by the torque release mechanism (not shown) to return to the original position. Through the above steps, the connection of the caulking joint to the pipe 1 is completed. As described above, the sleeve 31 is tightened by the nut 4 fitted on the outer peripheral surface of the sleeve 31 and pressed against the tube 1, and the joint member 3 is hermetically joined to the joint end of the tube 1.

  When Steps S1 to S4 are completed, it is checked at Step S5 whether the mark 11 is at a position corresponding to the tip of the sleeve 31 as shown in FIG. If the position of the mark 11 coincides with the tip of the sleeve 31 in this manner, the tube 1 is connected to the joint member 3 while being inserted into the sleeve 31 to the full insertion margin as shown in FIG. Can be determined to be. When the position of the mark 11 is shifted from the tip of the sleeve 31 as shown in FIG. 20A, it is determined that the insertion of the tube 1 into the sleeve 31 is insufficient as shown in FIG. Is done. In this case, since the sealability and strength of the connection part remain uneasy, the pipe 1 is cut and connected again to another caulking joint.

  When the connection between the pipe 1 and the caulked joint is normally completed by the above procedure, as step S6, another step is performed on the other pipe connecting portion 34 of the joint member 3 by a process including steps S1 to S5 similar to the above. Connect tube 1. Thus, as shown in FIG. 21, one tube 1 and another tube 1 are provided with two insert members 2 and 2, two nuts 4 and 4, and one tube with two tube connection portions 34 and 34. The joint member 3 is connected via a caulking joint. When using a joint member 3 having a larger number of pipe connections such as a T-shaped or Y-shaped pipe having three pipe connections, steps S1 to S5 are performed. Is repeated for the number of connections.

  In the step of connecting the caulking joint and the pipe 1 as described above, when the sleeve 31 of the joint member 3 is deformed by receiving a force from the inner peripheral surface of the nut 4, the pipe 1 located inside the sleeve 31 is also With the deformation of the sleeve 31, it receives a force from the inner peripheral surface of the sleeve 31 and compressively deforms radially inward. The inner periphery of the deformed tube 1 is strongly pressed against the outer peripheral surface of the insert member 2 located further inside, and as a result, the diameter between the sleeve 31 of the joint member 3 and the tube 1 and the insert member 2 is increased. Strong adhesion occurs in the direction.

  There is no leakage in the connection structure using such caulking joints, and the entire structure is made of metal, so it is used for refrigerant piping of air conditioning equipment, such as resistance to heat and temperature changes and resistance to pressure differences between inside and outside. It has various properties suitable for use.

  As a document indicating a general technical level regarding such a caulked joint, there is, for example, Patent Document 1 below.

JP 2010-255775 A

However, in the case of the above-described swaged joint, since the insert member 2 having a size in which the outer diameter of the main body 21 substantially matches the inner diameter of the pipe 1 is used, the insert member 2 is inserted as shown in FIG. The inner diameter l ₂ of the inserted portion is smaller than the inner diameter l ₁ of the other portion of the pipe 1 by the thickness of the main body 21 of the insert member 2. In some cases, the inner diameter l ₃ of the joint member 3 of the tube part 30 and the stepped portion 33, may be small compared to the inside diameter l _1. When the caulking joint having such a structure is used for connecting the refrigerant pipe, there is a problem that the internal resistance of the pipe increases at the caulking joint part, and the refrigerant is difficult to flow.

  Also, in the above-described step of connecting the caulking joint and the pipe 1, a procedure of inserting the end of the pipe 1 into which the insert member 2 is inserted into the sleeve 31 of the joint member 3, attaching the mark 11, and then removing it once (step) S2, see FIG. 12) is troublesome, and there has been a demand for a structure of the pipe 1 or a caulked joint that allows the insertion margin to be easily confirmed without the mark 11.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims to provide a connection method and a connection structure of a pipe and a caulked joint which can reduce a pipe resistance and can omit a trouble of confirming a pipe insertion margin.

The present invention has a cylindrical main body having a uniform circular cross-section and a flange protruding at one end of the outer periphery of the main body at the metal end through which the fluid flows, and has the tube from the inside. After inserting the main body portion of the insert member of the high-strength steel to be supported until the flange portion abuts against the end face of the joining end , a metal material having malleability at the end portion of the tube portion communicating with the tube is used. A joint member comprising a sleeve configured to cover the outer periphery of the tube end from the outside and a stepped portion extending to the inner periphery on the base side of the sleeve is provided at the end of the tube with the flange of the insert member being the flange. Attached so as to be in contact with the end of the stepped portion, and a tapered portion whose outer diameter decreases toward the tip starting from a position separated by a predetermined distance from the base toward the tip is used as the inner sleeve. Inside diameter of at least part of the peripheral surface is front A nut of high-strength steel having a tapered portion whose inner diameter increases toward the end on at least a part of the inner peripheral surface so as to have an inner diameter smaller than a part of the outer diameter of the tapered portion of the sleeve in the axial direction By pressing the sleeve and the end of the tube radially inward through the nut and pressing against the outer peripheral surface of the insert member to connect the tube and the joint member. Forming an enlarged diameter portion at a portion corresponding to the insertion margin of the tube end portion, and providing a visually visible step on an outer periphery of a base portion side of the enlarged diameter portion ,
As the insert member, one having an inner diameter equal to the inner diameter of a portion other than the enlarged diameter portion of the pipe is used, and as the joint member, one having an inner diameter of a tube body portion equal to or larger than the inner diameter of the insert member is used. It relates to a method of connecting a pipe to be swaged and a swaged joint.

In this way, it is possible to suppress an increase in the pipe resistance at the swaged joint portion, and it is not necessary to provide a step of marking the insertion allowance. Further, as the insert member, using an inner diameter equal to the inner diameter of the portion other than the enlarged diameter portion of the pipe, as the joint member, by using an inner diameter of the pipe body portion or more than the inner diameter of the insert member, It is possible to more reliably prevent an increase in the pipe resistance at the caulked joint.

Further, the present invention has a cylindrical main body having an even circular cross section and a flange protruding at one end of the outer periphery of the main body at an end of a metal pipe through which a fluid flows. After inserting the main body portion of the high-strength steel insert member that supports the tube from the inside until the flange portion abuts against the end face of the joining end , the malleable portion is inserted into the end portion of the tube portion communicating with the tube. A joint member comprising a sleeve made of a metal material and covering the outer periphery of the tube end from the outside and a stepped portion projecting to the inner periphery on the base side of the sleeve is provided at the end of the tube with the insert member of the insert member. Attached so that the flange portion is in contact with the end of the step portion, the tapered portion whose outer diameter decreases toward the tip starting from a position separated by a predetermined distance from the base toward the tip is formed on the outer peripheral surface of the sleeve. On the other hand, at least a part of the inner peripheral surface A high-strength steel nut in which at least a part of the inner peripheral surface has a tapered portion whose inner diameter increases toward the end so that the inner diameter has an inner diameter smaller than a part of the outer diameter of the tapered portion of the sleeve. By pressing axially, the sleeve and the end of the tube are compressed radially inward through the nut and pressed against the outer peripheral surface of the insert member to connect the tube and the joint member. A connection structure between a pipe and a caulked joint,
An enlarged diameter portion is formed at a portion corresponding to the insertion margin of the pipe end, and a step which is visually recognizable is provided on a base side outer periphery of the enlarged diameter portion ,
A pipe and swaging joint , wherein the inner diameter of the insert member is equal to the inner diameter of a portion other than the enlarged diameter portion of the pipe, and the inner diameter of the tubular body of the joint member is equal to or larger than the inner diameter of the insert member. It is related to the connection structure.

Thus, in the connection structure between a pipe and a caulked joint according to the present invention, when the pipe and the caulked joint are connected, an increase in the pipe resistance at the caulked joint can be suppressed, and a step of providing a mark indicating the insertion allowance. Do not need. Further, the inner diameter of the insert member is equal to the inner diameter of the portion other than the enlarged diameter portion of the pipe, and the inner diameter of the tube portion of the joint member is equal to or larger than the inner diameter of the insert member, so that the caulked joint portion is formed. An increase in pipe resistance can be more reliably prevented.

  ADVANTAGE OF THE INVENTION According to the connection method and connection structure of the pipe and the swaged joint of the present invention, it is possible to provide an excellent effect that the pipe resistance can be reduced and the trouble of confirming the insertion margin of the pipe can be omitted.

It is a perspective view which shows the connection structure of the pipe and the crimping joint of this invention, (a) is a pipe, (b) is an insert member, (c) is a joint member, (d) is a nut, (e) is another of a pipe. (F) is an example of still another form of the tube. It is sectional drawing which shows the connection structure of the pipe and the crimping joint of this invention, (a) is a pipe, (b) is an insert member, (c) is a joint member, (d) is a nut, (e) is another of a pipe. (F) is an example of still another form of the tube. It is a flowchart which shows the connection method of the pipe and the swage joint of this invention. It is explanatory drawing which shows the connection procedure of the pipe and the caulking joint by this invention, (a) is a perspective view, (b) is sectional drawing. It is explanatory drawing which shows the connection procedure of the pipe and the caulking joint by this invention, (a) is a perspective view, (b) is sectional drawing. It is a perspective view which shows the connection procedure of the pipe and the crimping joint by this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a completed view which shows the state which connected the pipes by the connection method and connection structure of the pipe and the caulking joint of this invention, (a) is a perspective view, (b) is sectional drawing. It is a perspective view which shows the pipe and the parts of the crimping joint connected to this pipe, (a) is a pipe, (b) is an insert member, (c) is a joint member, (d) is a nut. It is sectional drawing which shows the pipe and the parts of the crimping joint connected to this pipe, (a) is a pipe, (b) is an insert member, (c) is a joint member, (d) is a nut. It is a front view which shows a caulking joint tool, (a) is the state which removed the jig, (b) is the state which attached the jig. It is a perspective view which shows the jig of a caulking coupling tool, (a) is a 1st jig, (b) is a 2nd jig. It is a flowchart which shows the connection method of the conventional pipe | tube and a caulking joint. It is explanatory drawing which shows the connection procedure of the conventional pipe | tube and a caulking joint, (a) is a perspective view, (b) is sectional drawing. It is explanatory drawing which shows the connection procedure of the conventional pipe | tube and a caulking joint, (a) is a perspective view, (b) is sectional drawing. It is a perspective view which shows the connection procedure of the conventional pipe | tube and a caulking joint. It is explanatory drawing which shows the connection procedure of the conventional pipe | tube and a caulking joint, (a) is a perspective view, (b) is sectional drawing. It is explanatory drawing which shows the procedure which connects a pipe and a caulking joint with a caulking joint tool, (a) is a front view, (b) is a top view. It is a top view which shows the procedure which connects a pipe and a caulking joint with a caulking joint tool. It is explanatory drawing which shows the conventional procedure which connects a pipe and a caulking joint with a caulking joint tool, (a) is a perspective view, (b) is sectional drawing. It is explanatory drawing which shows the conventional procedure which connects a pipe and a caulking joint with a caulking joint tool, (a) is a perspective view, (b) is sectional drawing. It is a completed view showing the state where pipes were connected by a conventional connection method and connection structure of pipes and caulked joints, where (a) is a perspective view and (b) is a cross-sectional view.

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

  1 and 2 show an example of a connection structure between a pipe and a caulked joint according to an embodiment of the present invention. The basic configuration of the caulking joint (insert member 2, joint member 3, nut 4), the caulking joint tool 5, the first jig 54, and the second jig 55 used for connecting the pipes is the above-described conventional example (FIGS. 8 to 8). 11 (see FIG. 11), but in the case of the present embodiment, as shown in FIGS. 1 (a) and 2 (a), an enlarged diameter portion 12 is provided at the end of the pipe 1 for connection with a caulking joint. There is a feature in the point. Also, each component (insert member 2, joint member 3, nut 4) of the caulking joint, the first jig 54, and the second jig 55 are also larger in size than the conventional example in order to match the enlarged diameter portion 12. (These sizes will be described in detail later).

  The enlarged diameter portion 12 is a portion whose inner diameter and outer diameter are both wider than other portions of the tube 1, and as shown in FIGS. Provided over a range. This length L is the length covered by the sleeve 31 of the joint member 3 when the end of the tube 1 into which the insert member 2 has been inserted is inserted into the sleeve 31 of the joint member 3, similarly to the length L in the above-described conventional example. That is, the enlarged diameter portion 12 is provided in a range corresponding to the insertion allowance in the pipe 1 of the present embodiment.

  A step 13 is formed on the base side of the outer periphery of the enlarged diameter portion 12 as the diameter is increased. The difference between the outer diameter of the step 13 and the outer diameter of the enlarged diameter portion 12 and other portions is exaggerated in FIGS. 1A and 2A, but is actually so clear. The step does not need to be a step, and it is sufficient that the step is formed such that the step 13 can be visually recognized. For example, as shown in FIG. 1A, FIG. 2A, or FIG. 1E and FIG. 2E, when the step 13 has a stepped cross-sectional shape, the difference in the outer diameter is small. 1 (f) and FIG. 2 (f), and may be a step 13 having a tapered shape. In addition, the step 13 can take various shapes as long as it can be visually recognized.

  When handling a pipe 1 at a construction site or the like, as described above, a pipe 1 cut from a fixed-length pipe and having an appropriate length according to the dimensions of the site is often used. In this case, The end of the pipe 1 needs to be processed on site by a pipe expander or the like to form the enlarged diameter portion 12 or the step 13. On the other hand, when the dimensions of the pipe 1 to be used are determined in advance, such as when the pipe 1 having various dimensions is manufactured as a processing pipe in a factory and carried into the site, the enlarged diameter portion 12 or the step 13 is formed in advance. The prepared tube 1 can also be used. In addition, when there is a portion where another tube is added and extended without cutting the fixed-length tube 1, the end of the fixed-length tube 1 may be processed in advance.

  The size of the swaged joint (see FIGS. 1 (b) to (d) and FIGS. 2 (b) to (d)) used for the connection will be described. In the case of this embodiment, the diameter of the pipe 1 is increased as the insert member 2. The outer diameter of the main body 21 is substantially the same as the inner diameter of the section 12, and the inner diameter of the main body 21 is equal to the inner diameter of the portion other than the enlarged diameter section 12 of the pipe 1. That is, the main body portion 21 whose thickness is substantially the same as the enlarged diameter of the inner diameter of the enlarged diameter portion 12 is used. Alternatively, the enlarged diameter portion 12 is formed in the pipe 1 according to the thickness of the insert member 2.

  As the joint member 3, a member having a size in which the inner diameter of the sleeve 31 substantially matches the outer diameter of the enlarged diameter portion 12 of the tube 1 is used. Alternatively, the enlarged diameter portion 12 is formed in the tube 1 in accordance with the inner diameter of the sleeve 31. The inner diameter of the tubular portion 30 or the step portion 33 is substantially equal to the inner diameter of the insert member 2 or is larger than the inner diameter of the insert member 2.

  In the nut 4, the inner diameter of the tip (the portion with the largest inner diameter) of the tapered portion 4a of the inner peripheral surface is larger than the outer diameter of the tip (the portion with the smallest outer diameter) of the sleeve 31 of the joint member 3. 31 is smaller than the outer diameter of the portion other than the tapered portion 31a (the base portion having the largest outer diameter).

  As described above, the insert member 2, the joint member 3, and the nut 4 are each one size larger than the conventional example because the size of the inner diameter and the outer diameter of the pipe 1 is adjusted to the enlarged diameter portion 12. A material having a large diameter (equivalent to the thickness of the insert member 2) will be used.

  Further, as the insert member 2, a member in which the axial length of the main body portion 21 matches the insertion margin of the pipe 1, that is, the axial length L of the enlarged diameter portion 12, or is slightly shorter than that. Regarding the joint member 3, as described above, the enlarged diameter portion 12 is formed in the pipe 1 in accordance with the length of the sleeve 31 in the axial direction, but on the contrary, the end of the pipe 1 in which the insert member 2 is inserted. When the portion, that is, the enlarged diameter portion 12 is inserted into the sleeve 31, the joint member 3 may be selected so that the position of the step 13 coincides with the tip of the sleeve 31. In any case, it is only necessary that the position of the step 13 indicates the length of the insertion allowance. The length of the nut 4 in the axial direction is substantially equal to or slightly shorter than the length of the joint member 3 in the axial direction of the sleeve 31.

  The same tool as that used in the above-described conventional example is used as the caulking joint tool 5 (see FIG. 10A). The configuration of the first jig 54 and the second jig 55 is the same as that of the above-described conventional example (see FIG. 11). However, as described above, the diameter of the caulking joint used in the present embodiment is larger than that of the conventional example. Since it is large, it is necessary to use the first jig 54 and the second jig 55 suitable for the size.

  The procedure for connecting the pipe and the caulked joint according to the present embodiment will be described with reference to FIG. 3 and FIGS. FIG. 3 is a flowchart for explaining a method of connecting a pipe and a caulked joint according to an embodiment of the present invention, and FIGS. 4 to 7 are views showing steps in a connecting process of the pipe and a caulked joint. Here, a case will be described in which, instead of using the pipe 1 in which the enlarged diameter portion 12 or the step 13 is formed in advance, the pipe 1 is processed at the time of connection with the swage joint to form the enlarged diameter portion 12 and the step 13.

  First, in step S11 (see FIG. 3), the insert member 2 is inserted into the end of the tube 1. Prior to this, the end of the tube 1 is enlarged to form the enlarged portion 12. Using a tool such as a reamer (not shown), the inner diameter and the outer diameter are expanded over the length L from the distal end of the pipe 1 in accordance with the size of the insert member 2 and the joint member 3 described above. At this time, a step 13 is formed at a position of a length L from the tip of the tube 1. Here, as a tool used for expanding the diameter, for example, a bamboo saw drill-like reamer-type expanding device having a diameter and an axial length suitable for various standard sizes of the pipe 1 has a different diameter. An enlarged diameter portion 12 having a fixed shape can be formed at each end of the plurality of tubes 1. In such a tube expander, the expanded portion 12 can be formed at the end of the tube 1 by plastic working so as to push the end of the tube 1 from the inside. The burrs formed when the pipe 1 is cut are removed by plastic deformation, tearing, or the like in the work of expanding the diameter.

  After the enlarged diameter portion 12 is formed, the main body 21 of the insert member 2 is inserted into the end of the tube 1 as shown in FIG. As described above, the outer diameter of the main body 21 is substantially equal to the inner diameter of the tube 1 and the flange 22 projects from one end of the outer periphery of the main body 21, so that the flange 22 is positioned. The insert member 2 stops when the main body 21 is inserted to the position of the flange 22.

  Here, in the case of the conventional pipe 1 without the enlarged diameter portion 12 and the step 13, the end of the pipe 1 is once connected to the joint member as in step S2 (see FIGS. 12, 14 and 15) of the conventional example. Although it is necessary to temporarily insert the mark into the insertion margin 3 to mark the insertion margin, in the case of the present embodiment, the step 13 is a mark of the insertion margin, so this step is unnecessary.

  When the diameter expansion of the end of the pipe 1 and the insertion of the insert member 2 are completed, the process of marking is omitted, and the process proceeds to step S12, where the setting to the caulking joint tool 5 is performed. The subsequent steps S12 to S15 are the same as steps S3 to S6 in the above-described conventional example.

  As shown in FIG. 5, the end of the tube 1 in which the insert member 2 is inserted, that is, the enlarged diameter portion 12 is passed through the nut 4 and then inserted into the opening of the sleeve 31 of the joint member 3. The enlarged diameter portion 12 of the tube 1 into which the insert member 2 has been inserted stops when it is inserted to the position of the step portion 33. At this time, the position of the step 13 coincides with the tip of the sleeve 31 as shown in FIG. . At the time of insertion, an adhesive (not shown) may be applied to the outer periphery of the enlarged diameter portion 12.

  After the caulking joint (the insert member 2, the joint member 3, and the nut 4) is attached to the enlarged diameter portion 12 of the pipe 1, the pipe 1 and the caulking joint are set on the caulking joint tool 5. The first jig 54 is attached to the first pedestal 52 of the caulking joint tool 5 and the second jig 55 is attached to the second pedestal 53 (see FIG. 10B), and the first jig 54 and the second jig 55 are attached. The pipe 1 to which the caulking joint is attached is arranged on the upper side (see FIG. 17). The tube 1 is placed in the second support groove 62 of the second jig 55, and the nut 4 is provided between the second locking flange 63 of the second jig 55 and the first locking flange 59 of the first jig 54. The joint member 3 is arranged such that the tube portion 30 is located on the first locking flange 59 and the fulcrum portion 32 is located immediately near the first locking flange 59.

In step S13, the vise part 51 of the caulking joint tool 5 is operated. Similar to step S4 in the conventional example (see FIGS. 12 and 18), the first pedestal 52 on which the first jig 54 is mounted and the second pedestal 53 on which the second jig 55 is mounted operate so as to approach each other. . The surface of the first jig 54 on the side facing the second jig 55 of the first locking flange 59 abuts on the fulcrum 32 of the joint member 3, and the second locking flange 63 of the second jig 55 is , Abuts against the end of the nut 4, and the end of the nut 4 on the first jig 54 side is pressed against the tip of the sleeve 31 of the joint member 3.
Here, as described above, as the nut 4, the inner diameter of the tip side (the portion having the largest inner diameter) of the tapered portion 4 a formed on the inner peripheral surface is part of the sleeve 31 (the portion other than the tapered portion 31 a, The outer diameter of the tapered portion 31a (the portion near the base) is smaller than the outer diameter of the tapered portion 31a. Subsequently, when a force is further applied between the nut 4 and the joint member 3 by the operation of the vise part 51, the sleeve 31 of the joint member 3 made of a malleable material becomes a nut having high strength. As a result of being pressed against the nut 4 by a strong force in the axial direction, the nut 4 receives a force directed inward in the radial direction from the inner peripheral surface of the nut 4 and sinks into the nut 4 while being caulked. When the end of the nut 4 on the side of the first jig 54 reaches the vicinity of the fulcrum 32 of the joint member 3, the repulsive force from the caulking joint causes a torque release mechanism (not shown) to operate to release the pressure of the electric hydraulic unit, The compression operation in the axial direction by the vise 51 is stopped, and the first pedestal 52 and the second pedestal 53 operate so as to be separated from each other and return to the original position.

  Next, as step S14, an inspection of the connection location is performed. Here, the step 13 is used as a mark instead of the mark 11 of the conventional example, and it is confirmed whether or not this position coincides with the tip of the sleeve 31 as shown in FIG. As described above, as the nut 4, a nut whose axial length is substantially equal to or slightly shorter than the axial length of the sleeve 31 of the joint member 3 is used, as shown in FIG. If the end of the nut 4 on the tube body 30 side reaches the fulcrum 32, the position of the tip of the sleeve 31 can be visually recognized.

  When the connection between the pipe 1 and the caulked joint is normally completed by the above procedure, as step S15, another step is performed on the other pipe connection portion 34 of the joint member 3 by the process including steps S11 to S14 similar to the above. Connect tube 1. Thus, as shown in FIG. 7, one tube 1 and another tube 1 have two insert members 2, 2; two nuts 4, 4; and one tube with two tube connections 34, 34. The joint member 3 is connected via a caulking joint.

  Here, as described above, the insert member 2 is such that the inner diameter of the main body portion 21 is equal to the inner diameter of the portion other than the enlarged diameter portion 12 of the tube 1, and the joint member 3 also has a tubular body portion. Since the inner diameter of the step 30 or the step 33 is substantially equal to the inner diameter of the insert member 2 or larger than the inner diameter of the insert member 2, the pipe resistance is not increased at the swaged joint portion, and the refrigerant of the air conditioning equipment is not used. There is no problem in using caulked joints for piping.

  Note that the inner diameter of the main body 21 does not necessarily have to be exactly equal to the inner diameter of the portion other than the enlarged diameter portion 12 of the tube 1. The diameter of the end of the pipe 1 is increased to provide an enlarged diameter portion 12, and the insert member 2 and the joint member 3 having a size corresponding to the enlarged diameter portion 12 are used. 9 (b), see FIG. 21), the inner diameter of the main body 21, the pipe body 30 or the stepped portion 33 is increased, and the increase in the pipe resistance at the caulking joint portion is such that the flow of the refrigerant is not hindered. What is necessary is just to be able to suppress up to.

  As described above, according to the present embodiment, the high-strength steel insert member 2 that supports the pipe 1 from the inside is inserted into the end of the metal pipe 1 through which the fluid flows, and then the pipe is inserted. At the end of the tube 1, a joint member 3, which is made of a malleable metal material and has a sleeve 31 that covers the outer periphery of the end of the tube 1 from the outside, is attached to the end of the tube 1. A sleeve 31 having a tapered portion 31a whose outer diameter decreases toward the distal end from the sleeve 31 having a tapered portion 31a whose outer diameter decreases toward the distal end starting from a position separated from the sleeve by a predetermined distance toward the distal end. The nut 4 made of high-strength steel having a tapered portion 4a whose inner diameter increases toward the end on at least a part of the inner peripheral surface thereof so as to have an inner diameter smaller than a part of the outer diameter of the tapered portion. By pressing in the direction A method for connecting a tube and a caulked joint for connecting the tube 1 and the joint member 3 by compressing and deforming the sleeve 31 and the end of the tube 1 radially inward through the nut 4 and pressing against the outer peripheral surface of the insert member 2. An enlarged diameter portion 12 is formed at a portion corresponding to the insertion margin at one end, and a step 13 that can be visually recognized is provided on an outer periphery of a base portion side of the enlarged diameter portion 12, thereby suppressing an increase in piping resistance at a caulking joint portion. And a step of marking the insertion margin is not required.

In the present embodiment, the insert member 2 has an inner diameter l ₂ equal to the inner diameter l ₁ of the portion other than the enlarged diameter portion 12 of the pipe 1. since ₃ used more than the inside diameter l ₂ of the insert member 2 can more reliably prevent an increase in the pipe resistance in the portion of the caulking joint.

  Therefore, according to the present embodiment, the pipe resistance can be reduced, and the trouble of confirming the insertion margin of the pipe can be omitted.

  The connection method and connection structure between the pipe and the swaged joint according to the present invention are not limited to the above-described embodiment. For example, in the above-described embodiment, an example has been described in which the pipe is processed at the time of connection with the swaged joint to form the enlarged diameter portion and the step. However, a pipe having an enlarged diameter portion or a step may be used in advance. . In addition, it goes without saying that various changes can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Pipe 2 Insert member 3 Joint member 4 Nut 4a Taper part 5 Caulking joint tool 12 Large diameter part 13 Step 30 Pipe part 31 Sleeve 31a Taper part

Claims (2)

At the metal end through which fluid flows , a cylindrical body having a uniform circular cross-section and a flange protruding at one end of the outer periphery of the body have a high strength for supporting the pipe from the inside. After inserting the main body portion of the steel insert member into the inside until the flange portion abuts against the end face of the joining end portion, the main body portion is formed of a metal material having malleability at an end portion of a tube portion communicating with the tube, and A joint member having a sleeve that covers the outer periphery of the tube end from the outside and a stepped portion extending to the inner periphery on the base side of the sleeve is provided at the end of the tube with the flange of the insert member being the end of the stepped end. Attached so as to abut the portion, the tapered portion whose outer diameter decreases toward the tip starting from a position separated by a predetermined distance from the base toward the tip is formed on the outer peripheral surface of the sleeve. At least a portion of the inner diameter of the sleeve A nut of high-strength steel having a tapered portion whose inner diameter increases toward the end on at least a part of the inner peripheral surface is pressed in the axial direction so as to have an inner diameter smaller than a part of the outer diameter of the tapered portion. Thereby, the sleeve and the pipe end are compressed radially inward through the nut and pressed against the outer peripheral surface of the insert member to connect the pipe and the joint member with a swaged joint. hand,
An enlarged diameter portion is formed at a portion corresponding to the insertion margin of the pipe end, and a step that can be visually recognized is provided on the outer periphery of a base side of the enlarged diameter portion ,
As the insert member, one having an inner diameter equal to the inner diameter of a portion other than the enlarged diameter portion of the pipe is used, and as the joint member, one having an inner diameter of a tube body portion equal to or larger than the inner diameter of the insert member is used. To connect the pipe to be swaged and the swaged joint. At the end of a metal tube through which fluid flows, there is a cylindrical main body having a uniform circular cross section and a flange protruding at one end of the outer periphery of the main body, and supports the pipe from the inside. After inserting the main body portion of the insert member of high-strength steel until the flange portion comes into contact with the end face of the joining end portion, the main body portion is formed of a metal material having malleability at an end portion of a tube portion communicating with the tube. A joint member having a sleeve that covers the outer circumference of the pipe end from the outside and a stepped portion that projects to the inner circumference on the base side of the sleeve is provided at the end of the pipe at the flange of the insert member. The inner peripheral surface is attached to the inner peripheral surface with respect to the sleeve having an outer peripheral surface formed with a tapered portion whose outer diameter decreases toward the distal end from a position separated from the base by a predetermined distance toward the distal end as a starting point. At least a part of the inner diameter is A high-strength steel nut formed in at least a portion of the inner peripheral surface with a tapered portion having an inner diameter that increases toward the end so as to have an inner diameter smaller than a part of the outer diameter of the tapered portion in the axial direction. The sleeve and the end of the tube are compressed and deformed radially inward through the nut and pressed against the outer peripheral surface of the insert member, thereby connecting the tube and the joint member. A joint connection structure,
An enlarged diameter portion is formed at a portion corresponding to the insertion margin of the pipe end, and a step which is visually recognizable is provided on a base side outer periphery of the enlarged diameter portion ,
A pipe and swaging joint , wherein the inner diameter of the insert member is equal to the inner diameter of a portion other than the enlarged diameter portion of the pipe, and the inner diameter of the tubular body of the joint member is equal to or larger than the inner diameter of the insert member. Connection structure.

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