JP2009197919A - Method of manufacturing piping joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a piping joint improving mountability while maintaining the seal performance and the pulling strength. <P>SOLUTION: The method of manufacturing the piping joint connects a connection pipe 2 and an elastic pipe 4 by caulking from the outside, and locks and fixes a cylindrical caulking member 3 in which the connection pipe 2 for connection is inserted and the elastic pipe 4 of elastic material is inserted in an annular space between the inner periphery and the outer periphery of the connection pipe 2. The caulking member 3 is provided with a bulging section 34 larger in diameter than other portions. The method includes: an assembling process of assembling the caulking member 3, the connection pipe 2 and the elastic pipe 4 so that the connection pipe 2 and the elastic pipe 4 are arranged inside the bulging section 34; and a caulking process of caulking the opposite sides of the bulging section 34 after the assembling process. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a pipe joint, and is suitable for use in, for example, a joint part of a refrigerant hose that connects functional parts of a refrigeration cycle.

  Conventionally, as described in Patent Document 1, a method of manufacturing a pipe joint using a rubber hose joint fitting including a sleeve (caulking member) and a nipple (metal pipe) is known.

In the method described in Patent Document 1, first, the sleeve is inserted into the outer periphery of the nipple so that the opening end of the sleeve is aligned with the opening end of the nipple. Then, a rubber hose (elastic tube) is inserted between the nipple and the sleeve. Next, the outer peripheral surface of the sleeve is crimped by deforming a plurality of locations in the circumferential direction inward in the radial direction using a known caulking device (two-claw type). Thereby, the thick part of the rubber hose is compressed and caulked, and the rubber hose is fixed between the nipple and the sleeve.
JP 2001-41377 A

  However, in the method according to the above configuration, when caulking with two claws, the flowing rubber easily escapes from between the caulking portions adjacent to each other in the axial direction to the outside of the caulking portion. If the flowing rubber escapes to the outside of the caulking part, a gap is created between the sleeve and the rubber hose between the caulking parts, and the sealing performance is deteriorated. The strength (prevention force) becomes small. Therefore, in order to secure the sealing performance and the tensile strength (prevention force) of the caulking member, the caulking portion (sleeve) needs to have a certain length.

  For this reason, the space allocated to the rubber hose has decreased with the increase in equipment mounted in the engine room recently, and the mounting space is required to be compact while the mounting space is required. There was a problem.

  In view of the above problems, an object of the present invention is to provide a method for manufacturing a pipe joint that can improve the mountability while maintaining the sealing performance and the tensile strength.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the present invention, the connecting pipe (2) to be connected is inserted, and the elastic pipe (4) made of an elastic material is inserted into the annular space between the inner periphery and the outer periphery of the connecting pipe (2). A method of manufacturing a pipe joint for connecting a connecting pipe (2) and an elastic pipe (4) by caulking the cylindrical caulking member (3) formed from the outside to prevent it from coming off and fixing the connecting pipe (2) and the elastic pipe (4). The member (3) is formed with a bulging portion (34) having a diameter larger than that of other portions, and the connecting tube (2) and the elastic tube (4) are arranged inside the bulging portion (34). And an assembling step for assembling the caulking member (3), the connecting tube (2), and the elastic tube (4), and a caulking step for caulking both sides of the bulging portion (34) after the assembling step. .

  For example, in a pipe joint of a rubber hose for connecting refrigerants to the functional parts of a refrigeration cycle of a vehicle air conditioner (compressor and condenser, etc.) and flowing a refrigerant, for example, a metal pipe (connecting pipe (2 The present invention can be applied when a rubber hose (elastic tube (4)) is connected to and a connection site is caulked and fixed using a metal fitting (caulking member (3)).

  According to this configuration, the caulking member (3) is caulked on both sides of the swollen portion (34) that has been swollen in advance, thereby suppressing the outflow of the elastic material to the outside between the swaging portions (the swollen portion (34)) and being elastic. The material can flow into the bulge (34). By allowing the elastic material to flow into and stay in the bulging portion (34), it is possible to improve the sealing performance and the tensile strength (prevention force) at the joint portion between the connecting pipe (2) and the elastic pipe (4). Thereby, since the seal | sticker surface pressure site | part in a caulking member (3) can be shortened, ie, the caulking member (3) itself can be shortened, the mountability of a piping joint site | part can be improved. .

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description later mentioned.

(First embodiment)
FIG. 1 is a cross-sectional view of a joint portion 1 for explaining a method of manufacturing a pipe joint according to an embodiment to which the present invention is applied. In FIG. 1, (a) shows the mode after the assembly process, (b) shows the mode at the caulking process, and (c) shows the mode after the caulking process.

  This embodiment is a rubber hose joint that connects the functional components of the refrigeration cycle of the vehicle air conditioner and flows the refrigerant, for example, a high-pressure hose between the compressor and the condenser, or between the evaporator and the compressor. It is a joint of a low pressure hose.

  As shown in FIG. 1, the joint portion 1 includes a pipe 2 as a connection pipe to be connected to the functional component side, a sleeve 3 arranged concentrically on the outer peripheral side of the pipe 2, and a pipe 2. It has a rubber hose 4 for refrigerant circulation to be connected.

  The pipe 2 is formed in a required length in a straight pipe shape made of metal (for example, iron or aluminum). A ring-shaped concave groove 21 is formed on the outer peripheral surface of one end side (right side in FIG. 1) of the pipe 2. A concave groove 22 having a ring shape and a trapezoidal cross section is formed at two locations on the outer peripheral surface on one end side of the concave groove 21.

  The sleeve 3 is made of metal (for example, iron or aluminum) and is formed in a substantially cylindrical shape. The sleeve 3 includes a cylindrical portion 31 that has a cylindrical shape, and an end plate 32 that extends radially inward so as to close the opening on the other end side (left side in FIG. 1) of the cylindrical portion 31. It is configured. A hole 33 having a diameter slightly larger than the outer diameter of the pipe 2 is formed at the center of the end plate 32.

  Further, a bulging portion 34 bulging radially outward is formed at a substantially intermediate portion of the cylindrical portion 31 so as to protrude over a plurality of locations in the circumferential direction. The cross-sectional shape of the bulging portion 34 has a substantially triangular shape with a gentle apex portion, and the inside of the substantially triangular shape is a space wider outward in the radial direction than the other portions of the cylindrical portion 31. In addition, the formation position and the number of the bulging portions 34 are determined when the caulking device 5 (see FIG. 1B) is deformed and caulked by deforming a plurality of locations in the circumferential direction radially inward (details will be described later). In FIG. 4, the position corresponds to the location to be caulked.

  The sleeve 3 has a thickness of about 1 to 2 mm, a length in the longitudinal direction of about 20 to 30 mm, and a length in the longitudinal direction of the bulging portion 34 (interval between the caulking claws 51 (see FIG. 1B)) is about 7. The clearance between the sleeve 3 and the rubber hose 4 is about 1 mm.

  The rubber hose 4 is an elastically deformable rubber refrigerant hose having a reinforcing fiber thread inside, and the thickness when not elastically deformed is, for example, about 3.5 mm. Further, the inner diameter of the rubber hose 4 is the same as the outer diameter of the pipe 2, and the outer diameter of the rubber hose 4 is slightly smaller than the inner diameter of the sleeve 3. For this reason, when the rubber hose 4 is disposed inside the sleeve 3 at the time of assembling described later, a predetermined clearance is generated between the inner periphery of the sleeve 3 and the rubber hose 4.

  Next, a procedure for coupling and fixing the rubber hose 4 to the pipe 2 (a method for manufacturing a pipe joint) will be described. In this embodiment, the sleeve 3 and the rubber hose 4 are assembled from the right side to the left side on the pipe 2 that protrudes to the right side in FIG.

(Assembly process)
First, the sleeve 3 is inserted into the pipe 2 so that the hole 33 formed in the end plate 32 of the sleeve 3 is aligned with the open end (right end in FIG. 1) of the pipe 2, and the sleeve is placed on the concave groove 21 of the pipe 2. 3 end plates 32 are arranged. Next, the outer peripheral surface of the end plate 32 is caulked radially inside by a known caulking device, and the inner peripheral surface of the end plate 32 is fitted into the concave groove 21 and fixed.

  Next, the rubber hose 4 is inserted between the pipe 2 and the sleeve 3 until the tip of the rubber hose 4 is positioned on the end plate 32 of the sleeve 3. This is the assembly process. After the assembly, as shown in FIG. 1A, the pipe 2, the sleeve 3, and the rubber hose 4 have a predetermined clearance between the inner periphery of the sleeve 3 (tubular portion 31) and the outer periphery of the rubber hose 4. Are integrated.

(Caulking process)
Next, as shown in FIG. 1B, the both side portions of the bulging portion 34 of the sleeve 3 are deformed and caulked by a known caulking device 5 at a plurality of locations in the circumferential direction to the inside of the sleeve 3 in the radial direction. Thereby, as shown in FIG. 1C, the thickness of the rubber hose 4 is compressed and caulked, and the rubber hose 4 is fixed between the pipe 2 and the sleeve 3. The caulking amount (caulking rate) can be set as appropriate, but in the present embodiment, the size after caulking is generally caulked so that the apex portion of the bulging portion 34 and the height of the end plate 32 are the same.

  According to the present embodiment, since the sleeve 3 in which the bulging part 34 is formed in advance in the intermediate part is used and the both side parts of the bulging part 34 are caulked, the caulking part between the caulking parts (the bulging part 34) is outside. The outflow of rubber is suppressed, and the rubber easily flows into the bulging portion 34. And as shown in FIG.1 (c), when rubber | gum flows in and stays in the bulging part 34, the pipe 2 and the rubber hose 4 will be in a press-contact state reliably, and the sealing performance in the sleeve 3 can be improved. .

  And since the rubber | gum which stays in the bulging part 34 acts as a retaining of the rubber hose 4, the tensile strength (slipping prevention force) in the sleeve 3 can be improved. As a result, the seal surface pressure site (the axial length of the sleeve 3) in the sleeve 3 can be made shorter and smaller than before, and the mountability at the joint site can be improved. In addition, material costs can be reduced with downsizing.

  Further, by suppressing the outflow of rubber to the outside between the caulking portions (bulging portion 34), one end portion 35 (see FIG. 1C) of the sleeve 3 warps outward in the radial direction after caulking, for example, bulging. It is possible to prevent the skirt from spreading greatly outward in the radial direction from the portion 34. So-called bulge generation is suppressed as much as possible, so that damage or destruction of the sleeve can be suppressed.

  Furthermore, in this embodiment, as described above, it is possible to effectively ensure the sealing performance. In another aspect, the tensile strength can be ensured in this embodiment. As a result, the amount of caulking (caulking rate) can be reduced as compared with the conventional case. As a result, it is possible to avoid problems such as the caulking portion of the sleeve 3 deformed like a bow due to strong caulking, or the pipe 2 being carelessly deformed and crushed.

  Further, in the present embodiment, by forming the concave groove 22 in the portion corresponding to the caulking portion of the pipe 2, after caulking, the rubber flows into the concave groove 22 and fits into the groove 2. The tensile strength (prevention force) can be improved.

(Other embodiments)
In the above-described embodiment, the joint has been described as connecting the rubber hose 4 to the pipe 2. However, for example, a joint metal fitting constituted by the nipple and the sleeve 3 corresponding to the pipe 2 may be used to connect the two rubber hoses. The present invention may be applied in the case of fixing.

  In the said embodiment, although demonstrated as the rubber hose 4 for refrigerant | coolant piping of a refrigerating cycle, you may apply this invention not only to a refrigerating cycle but to the connection part of a radiator hose, for example.

  Although the bulging part 34 of the said embodiment assumed that the cross-sectional shape was substantially triangular shape, it is not limited to the shape, In addition, it is good also as shapes, such as a rectangular shape. That is, any shape may be used as long as the rubber that has flowed into the bulging portion 34 is retained inside during caulking.

  Further, the number of the bulging portions 34 in the axial direction is not limited to the above embodiment, and three or more rows may be formed in a side view. In this case, the caulking claw 51 of the caulking device 5 can be set and changed according to the number of the bulging portions 34 in parallel. For example, when the bulging portions 34 are formed in two rows, if the caulking claw is of a three-claw type, it can be configured as an embodiment in which both sides of each bulging portion 34 are caulked.

It is sectional drawing of the pipe joint for demonstrating the manufacturing method of the pipe joint which concerns on embodiment to which this invention is applied, Comprising: (a) is a figure which shows the aspect after an assembly | attachment process, (b) is a caulking process time The figure which shows the aspect of (c) is a figure which shows the aspect after a crimping process.

Explanation of symbols

1 Joint part 2 Pipe (connecting pipe)
3 Sleeve (Caulking member)
4 Rubber hose (elastic tube)
34 Swelling

Claims (1)

A caulking member in which a connecting pipe (2) to be connected is inserted and an elastic pipe (4) made of an elastic material is inserted into an annular space between the inner periphery and the outer periphery of the connecting pipe (2) (3) is a manufacturing method of a pipe joint for connecting the connecting pipe (2) and the elastic pipe (4) by securing the retaining pipe by caulking from the outside,
The caulking member (3) is formed with a bulging portion (34) having a diameter larger than that of the other portion, and the connecting tube (2), the elastic tube (4), and the inside of the bulging portion (34). An assembly step of assembling the caulking member (3), the connecting tube (2), and the elastic tube (4) so that
After the said assembly | attachment process, the manufacturing method of a piping joint provided with the caulking process which caulks both sides of the said swelling part (34).

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