JP2008164108A - Piping connection mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piping connection mechanism capable of easily confirming inappropriate brazing when inappropriate brazing is performed. <P>SOLUTION: The piping connection mechanism 1 connects one piping 2 to a joint or other piping 3 by fitting the end of the one piping 2 to the joint or an enlarged pipe part 5 formed at the end of the other piping 3 to form a fitting part 6 and brazing the fitting part 6, wherein the enlarged pipe part 5 is formed with a through hole 4, and an axis coincidence means 7 is provided for making the axes C of the one piping and joint or other piping 3 coincide with each other prior to brazing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a connection mechanism for piping connected by brazing.

  2. Description of the Related Art Conventionally, a pipe connection mechanism that connects two pipes by fitting an end part of one pipe to a pipe expansion part of another pipe and brazing the fitting part has been used. Such a pipe connection mechanism is used for a pipe connection part of a refrigerant circuit constituting an air conditioner (see, for example, Patent Document 1 below). For example, a pipe having a diameter of 6.35 mm to 50.8 mm requires about 0.1 mm to 0.2 mm on one side.

JP 2005-262248 A

It is difficult to confirm whether or not the joining of the pipes by brazing has been appropriately performed by visual inspection or the like, and is performed by a nondestructive test or the like. However, since such a test is very time-consuming, it is not practical to test all the brazed parts that exist in large numbers.

  The present invention has been made in view of the above-described conventional problems, and it is an object of the present invention to provide a pipe connection mechanism that can easily perform confirmation when improper brazing is performed. Is.

  In order to achieve the above object, the pipe connection mechanism according to the present invention is such that the end of one pipe is fitted into a pipe expansion part formed at the end of a joint or another pipe, and the gap between the overlapped parts is obtained. In the pipe connection mechanism that connects one pipe and a joint or another pipe by brazing, a through hole is formed in the pipe expansion portion.

  In the present invention, since the through hole is formed in the expanded portion of the joint or other piping connected to one pipe by brazing, the brazing material reaches from the tip of the expanded portion to the through hole during brazing, and the capillary phenomenon Fills the through hole. Therefore, it can be easily confirmed that the brazing material has reached the formation position of the through-hole and brazing has been performed appropriately.

Embodiment 1 FIG.
FIG. 1 is a perspective view of a state in which a first pipe 2 as one pipe and a second pipe 3 as another pipe are connected using a pipe connection mechanism 1 according to an embodiment of the present invention. These are sectional drawings of the state which connected the 1st piping 2 and the 2nd piping 3 by the said piping connection mechanism 1, Comprising: The figure (a) is a cross-sectional view, The figure (b) is a longitudinal cross-sectional view. In each figure, the pipe connection mechanism 1 according to the present embodiment is such that the lower end portion of the first pipe 2 that is one pipe is fitted into the pipe expanding section 5 that is formed at the upper end portion of the second pipe 3 that is another pipe. The fitting part 6 is comprised by the part overlapped and overlapped, and the clearance gap S of this fitting part 6 is connected by brazing.

The first pipe 2 and the second pipe are not particularly limited, and include copper pipes, aluminum pipes, steel pipes, brass pipes, titanium pipes, stainless steel pipes, and the like. You may join. Moreover, the magnitude | size of the diameter of the 1st piping 2 and the 2nd piping is not specifically limited, For example, piping with a diameter of 6.35 mm thru | or 50.8 mm etc. are used.

  FIGS. 3A and 3B are partial cross-sectional views of the lower end portion of the first pipe 2, wherein FIG. 3A is a transverse cross-sectional view and FIG. 3B is a vertical cross-sectional view. In the figure, an axial center matching means 7 is provided at a position corresponding to the vicinity of the upper portion of the portion of the first pipe 2 that is fitted to the expanded portion 5 of the second pipe 3. The axial center matching means 7 is for aligning the axial centers C of the first pipe 2 and the second pipe 3 (see FIG. 2), and is formed so as to protrude outward on the outer peripheral surface of the first pipe 2. It is composed of three triangular pyramid-shaped projections 8. The protrusion 8 is formed in advance in another process before brazing.

The protrusion 8 is processed by, for example, pressing a predetermined position on the inner peripheral surface of the first pipe 2 with a predetermined pressure using a jig such as a sharp protrusion or a press. The formation position of the protrusion 8 is in the vicinity of the position of the fitting portion 6 where the tip of the second pipe 3 abuts. Further, the protrusion 8 is formed on the same circumference orthogonal to the axis of the first pipe 2, and a figure formed by connecting the protrusion 8 with a straight line is formed at a position where it is an equilateral triangle, for example. Thereby, the axial centers of the first pipe 2 and the second pipe 3 can be matched more accurately.

The protrusion height of the protrusion 8 is made to coincide with the gap S generated between the first pipe 2 and the second pipe 3 when the axis C is made coincident, and the value also depends on the size of the pipe. However, for example, a pipe having a diameter of 6.35 mm is 0.1 mm on one side and a pipe having a diameter of 50.8 mm is about 0.2 mm on one side.

The 2nd piping 3 is provided with the pipe expansion part 5 expanded over the predetermined length L from the upper end part. The predetermined length L is a length that can secure the insertion depth necessary for brazing defined by the safety standard of the High Pressure Gas Safety Law. The length L is determined by the size of the pipe. For example, the length L is 6 mm for a pipe having a diameter of 6.35 mm, and 12 mm for a pipe having a diameter of 25.4 mm. A circular through hole 4 is formed in the central portion of the tube expansion portion 5 in the axial direction.

  The assembly procedure of the pipe connection mechanism 1 will be described below. First, the first pipe 2 is inserted and fitted into the expanded portion 3 of the second pipe 3. Since the first pipe 2 is provided with the axis coincidence means 7, the center C of the first pipe 2 and the second pipe 3 can be obtained simply by fitting the first pipe 2 to the expanded portion 5 of the second pipe 3. Can be matched. With the three points of the protrusion 8, a uniform gap S can be secured between the first pipe 2 and the second pipe 3.

Moreover, since the protrusion 8 is formed in the vicinity of the position where the tip of the second pipe 3 abuts in the fitting portion 6, the first pipe 2 can be inserted to the position where the protrusion 8 is formed. It can be confirmed that the first pipe 2 is sufficiently inserted to an appropriate length. Furthermore, a clicking sound is generated when the lower end of the first pipe 2 hits the tapered portion of the end of the expanded pipe 5. For this reason, the operator can confirm that the first pipe 2 has been inserted into the expanded portion 5 of the second pipe 3 by a predetermined length L or more by confirming this clicking sound.

Next, a brazing material R such as silver brazing, phosphor copper brazing, brass brazing or the like is poured into the fitting portion 6 and torch brazing or in-furnace brazing. At that time, a flux may be used. When the brazing material R has sufficiently penetrated the fitting portion 6, the brazing material R oozes out from the through hole 4 due to a capillary phenomenon. 4A shows a state in which the brazing material R oozes out from the through hole 4 and the through hole 4 is filled with the brazing material R. FIG. This state means that brazing is properly performed. Therefore, it is possible to easily confirm that the brazing has been appropriately performed by visually confirming the state in which the through hole 4 is filled with the brazing material R.

On the other hand, FIG. 2B shows a state in which the brazing material R does not ooze out from the through hole 4 and the through hole 4 is not filled with the brazing material R. This state means that the amount of the brazing material R is insufficient or that the brazing material R is filled only locally. Therefore, by visually confirming this state, it can be understood that proper brazing is not performed, and it can be easily determined that it is necessary to perform more appropriate brazing.

Further, FIG. 5C shows a state in which the brazing material R has oozed out from the through hole 4 and the brazing material R has overflowed from the through hole 4. This state means that the amount of brazing material R is excessive. Therefore, by visually confirming this state, it can be understood that proper brazing is not performed, and it can be easily determined that it is necessary to perform more appropriate brazing.

When the pipe connection mechanism 1 as described above is used for connection of piping of a refrigerant circuit constituting an air conditioner or the like, the problem of refrigerant gas leaking from the pipe can be avoided. That is, in general, the piping of the refrigerant circuit constituting the air conditioner and the like is three-dimensionally and very complicatedly arranged, so when connecting one pipe to another pipe in the manufacturing process, One pipe may be restrained by another connected pipe or part. For this reason, the axial center of a connection part shifts | deviates and the clearance gap of a fitting part becomes non-uniform | heterogenous, As a result, the problem that it becomes difficult to carry out appropriate brazing has arisen. Such inappropriately brazed refrigerant circuit piping has a risk of refrigerant gas leaking over many years of use.

Therefore, when the pipe connection mechanism 1 as described above is used for connection of the piping of the refrigerant circuit constituting the air conditioner or the like, the plurality of pipes constituting the refrigerant circuit have a very complicated structure, and Even in the case of being restrained, the axis center can be matched by the axis center matching means 7, and appropriate brazing can be performed. Further, it can be easily confirmed that proper brazing is performed by the through-hole 4 formed in the fitting portion 6. Therefore, the problem that the refrigerant gas leaks does not occur even when the piping of the refrigerant circuit constituting the air conditioner is used for many years.

In addition, since the projection 8 can ensure a uniform gap S between the first pipe 2 and the second pipe 3, the brazing material R can be evenly distributed in the gap S, and more appropriate brazing can be performed. Become. Furthermore, the protrusion 8 can prevent the first pipe 2 from coming off from the pipe expansion portion 5 in the process of fitting the first pipe 2 and the second pipe 3 before brazing.

  In addition, in said embodiment, although the 1st piping 2 and the 2nd piping 3 were connected, the piping connection mechanism of this invention is not limited to it, It replaces with the 2nd piping 3, uses a joint, and piping You may use when connecting a joint. Moreover, although the 1st piping 2 and the 2nd piping 3 were connected to the up-down direction, it is not limited to this, You may connect in the horizontal direction or the direction which inclined.

Moreover, although the axial center matching means 7 was provided in the 1st piping 2, it is not limited to this, You may provide in the 2nd piping 3. FIG. For example, the protrusion etc. which were formed in the inner peripheral surface of 2nd piping so that it might protrude toward the axial center of a pipe | tube may be sufficient. Such protrusions of the second pipe can be formed, for example, by pressing a predetermined position on the outer peripheral surface of the second pipe with a predetermined pressure using a jig such as a sharp protrusion or a press.

Further, the projection of the second pipe formed in this way may be formed in advance by a predetermined length, not the same as the length of the gap, and the tip of the formed projection may be cut. At that time, by adjusting the protrusion height of the protrusion remaining on the inner peripheral surface of the second pipe to correspond to the gap between the first pipe and the second pipe, the through hole and the shaft center matching means are It is good also as a structure which serves as both. As a result, it is possible to simultaneously form the through hole and the projection that is the axial center matching means, and the workability is improved.

In addition to the above, the axial center matching means 7 may be configured, for example, by making the cross-sectional shape of the expanded portion of the second pipe into a triangular shape, a quadrangular shape, a polygonal shape, or the like over a predetermined length. Good. In this case, the first pipe can be inscribed in the inner peripheral surface of the expanded pipe part, and the first pipe and the second pipe are axially aligned with the first pipe inserted into the expanded part and inscribed. Adjust to match. Further, the predetermined length may be the total length of the fitting portion or only a part thereof. As a result, when the second pipe is expanded, the cross-sectional shape of the tube expansion device is set to a triangle, a quadrangle, a polygon, or the like, so that the axial center coincidence means can be formed simultaneously with the tube expansion operation, and the workability is improved.

Moreover, the expanded pipe part 5 whose cross-sectional shape is circular may be formed in a straight line locally, and the cross-sectional shape may be configured as a shape in which a straight part and an arc part are mixed. In this case as well, the first pipe and the second pipe are adjusted so that their axes coincide with each other in a state where the first pipe is inserted and inscribed in the pipe expansion portion. Thereby, the magnitude | size of a pipe expansion part can be made smaller than the case where the cross-sectional shape of a pipe expansion part is made into a triangle, a square, or a polygon.

Further, although the number of the protrusions 8 is three, it may be two or four or more. In particular, the number is preferably 3 or more, more preferably 3. If there are three or more, it becomes possible to accurately match the axes of the first pipe and the second pipe, and if there are three, the effort to form the protrusions compared to the case of four or more. This is because workability is good because it can be omitted.

Moreover, although the through-hole 8 was formed in the center part of the height direction of the pipe expansion part 5 in FIG.1, 2,4, it is not limited to this, You may form in the other place of a fitting part. In particular, when it is formed near the lower end of the first pipe, the brazing material R fills the entire fitting part from the tip of the second pipe, which is the injection part of the brazing material R, to the vicinity of the tip of the first pipe. Since it can confirm that it is carried out, it is more preferable. Further, although one substantially circular through hole is formed, other shapes such as a triangular shape, a quadrangular shape, or a polygonal shape may be used, and two or more may be formed. When the number of through holes is two or more, it is more preferable because it is possible to visually confirm that the brazing material is properly filled at a plurality of positions, as compared with the case where the number of through holes is one.

The protrusion 8 is formed in the vicinity of the position where the tip of the second pipe 3 abuts in the fitting portion 6, but may be in the vicinity of the tip of the first pipe as long as it is the fitting portion 6. The center part in the axial direction of the fitting part may be used. In particular, it is preferable that the first pipe is in the vicinity of the position where the tip end of the second pipe abuts in that it can be confirmed that the first pipe has been inserted into the expanded portion of the second pipe to a predetermined depth.

It is a perspective view of two piping connected using the piping connection mechanism concerning one embodiment of the present invention. It is sectional drawing of the said piping connection mechanism. It is sectional drawing of one piping used for the said piping connection mechanism. It is a usage condition figure of the said piping connection mechanism.

Explanation of symbols

1 piping connection mechanism, 2, 3 piping, 4 through-holes, 5 expanded section, 6 fitting section, 7 axial center matching means.

Claims (3)

An end of one pipe is fitted to a pipe expansion part formed at an end of a joint or another pipe to form a fitting part, and the fitting part is brazed, whereby one pipe and a joint Alternatively, in the pipe connection mechanism for connecting to other pipes, a through hole is formed in the pipe expansion portion. An end of one pipe is fitted to a pipe expansion part formed at an end of a joint or another pipe to form a fitting part, and the fitting part is brazed, whereby one pipe and a joint Or, in a pipe connection mechanism for connecting to other pipes, a pipe connection characterized by having an axial center matching means for matching the axes of one pipe and a joint or another pipe prior to brazing. mechanism. An end of one pipe is fitted to a pipe expansion part formed at an end of a joint or another pipe to form a fitting part, and the fitting part is brazed, whereby one pipe and a joint Alternatively, in a pipe connection mechanism for connecting to other pipes, an axis that forms a through hole in the expanded pipe portion and aligns the axis of one pipe with a joint or another pipe prior to brazing. A pipe connection mechanism comprising a matching means.

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