JP3111070B1 - Piping joint structure - Google Patents

Abstract

An object of the present invention is to provide a joint structure for piping which can be formed with good workability and does not cause problems due to burrs even when the strength is increased by a reinforcing groove when formed by die casting. SOLUTION: Fitting holes 3 opened on both surfaces of a joint member 2
Then, the end of the pipe 1 is fitted and integrated. The joint member 2
Is formed by die casting, a pipe guide portion 5 that gradually expands toward the outside diameter toward the outside at both opening edges of the fitting hole 3, and is further formed on the outside diameter side from the pipe guide portion 5. A relief recess 6 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for piping used for connecting pipes of, for example, an air conditioner for a vehicle.

[0002]

2. Description of the Related Art Conventionally, as a pipe joint structure, a pipe is fitted into a fitting hole, and a bead portion is formed by caulking an open end of the pipe, thereby eliminating the need for brazing.
Some can be integrated with pipes. A relief recess is formed at one opening edge of the fitting hole so that the bead portion does not protrude from the end face. In addition, a reinforcing groove is formed on the inner peripheral surface of the fitting hole to increase the torsional strength.

[0003]

However, in the above-mentioned joint structure for piping, a relief recess is formed only on one side, and the insertion direction of the pipe is restricted, resulting in poor workability.

[0004] When the pipe joint structure is formed by die-casting, a parting line is located inside the fitting hole so that the part can be taken out of the mold. For this reason, burrs and the like generated on the inner peripheral surface are removed by reaming, but it is difficult to completely remove burrs generated in the reinforcing grooves. As a result, there is a possibility that a problem such as intrusion of the remaining burrs into the pipe may occur.

Accordingly, the present invention can be formed with good workability,
An object of the present invention is to provide a piping joint structure that does not cause a problem due to burrs at the time of reaming even when a reinforcing groove is provided when forming by die casting.

[0006]

According to the present invention, as a means for solving the above-mentioned problems, a pipe joint structure is formed by fitting an end of a pipe into a fitting hole opened on both surfaces of a joint member. In the above, the joint member is formed by die-casting, and at both opening edges of the fitting hole, a pipe guide portion that gradually expands outward toward the outer diameter side, and further from the pipe guide portion to the outer diameter side. A relief recess is formed.

[0007] With this configuration, the pipe can be fitted into the fitting hole from either side of the joint member. At this time, the pipe can be easily guided to the fitting hole by the pipe guide. When the open end of the pipe is crimped after fitting, the pipe can be easily expanded to the outer diameter side by the pipe guide on the opposite side. Also, the relief recess is
Since it is formed on both surfaces of the joint member, the formed bead portion can be reliably positioned in the relief recess without protruding from the surface even if the pipe is fitted from any direction of the fitting hole.

When a parting line of a mold is located in the fitting hole and a plurality of reinforcing grooves terminating at the parting line from at least one opening edge are formed, burrs generated are formed in the reinforcing grooves. This is preferable in that it can be reliably prevented.

In the case where the reinforcing grooves are formed from both opening edges of the fitting hole, the reinforcing grooves provided from both opening edges may be formed so as to be shifted in the circumferential direction by a parting line.

If the parting line at which the reinforcing groove terminates is formed so as to be shifted to one of the surfaces from the center of both sides of the joint member, when the die is opened by die-casting, the ejector pin is moved by the joint member. This is preferable in that it can be released from the mold without the use of a metal mold.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a piping joint structure according to this embodiment. This joint structure has a joint member 2 at the end of the pipe 1.
Are integrated with each other.

The joint member 2 is formed in a gourd shape by die-casting an aluminum alloy, and has a fitting hole 3 and a mounting hole 4 on both surfaces thereof. At both opening edges of the fitting hole 3, a pipe guide portion 5 and a relief concave portion 6 are formed. The pipe guide portion 5 is formed of a tapered surface whose inner diameter gradually increases toward the surface of the joint member 2. The escape recess 6 is further provided on the outer diameter side from the pipe guide portion 5, and a bead portion 8 formed by caulking the pipe 1 is located there. Further, on the inner peripheral surface of the fitting hole 3, a parting line P.
L. Are formed. Reinforcement groove 7
Are formed at an angle so that a member formed from one surface of the joint member 2 and a member formed from the other surface do not communicate with each other. That is, as long as the reinforcing grooves 7 are formed without interfering with each other, the larger the number, the more advantageous in terms of strength. In addition, the reinforcing groove 7 can be formed in various forms such as a V-shaped cross section and a U-shaped cross section.

The joint member 2 can be easily formed using a die casting machine. That is, the mold is clamped, the powder of the aluminum alloy is poured, the press-fit plunger is advanced, and after the high-pressure press-fit into the cavity, when the solidification is completed, the movable-side mold is retracted. In this case, FIG.
As shown in the figure, in the fitting hole 3, the inner core 100a located on the movable side is longer than the inner core 100b located on the fixed side. That is, the parting line P. L. Are shifted from the center by a predetermined dimension toward the fixed side. Therefore, the formed joint member 2 does not remain on the fixed side, is smoothly discharged by opening the movable-side mold, and falls without being held by the movable-side inner core 100a. As a result, there is no need for an ejector pin for projecting the joint member 2 formed on the fixed mold, and no burrs are generated on the fitting surface by the ejector pin, and a deburring operation is not required. In addition, the mold structure can be simplified and made compact.

The joint member 2 is completed by removing burrs generated on the inner surface (parting line PL) of the fitting hole 3 by reaming. By the way, the burrs generated in the fitting hole 3 only protrude inward from the inner surface, and are not formed in the reinforcing groove 7 as in the related art.
That is, since the reinforcing groove 7 always terminates in the middle of the inner surface of the fitting hole 3, no burr is generated in the reinforcing groove 7, and the reinforcing groove 7 is completely removed only by the reaming process.

A pipe 1 is connected to the completed joint member 2. The pipe 1 is smoothly inserted into the fitting hole 3 by the pipe guide 5 of the fitting hole 3. Then, it is connected to the joint member 2 by being expanded while being inserted into the fitting hole 3 of the joint member 2, and as shown in FIG.
Is formed so that the joint member 2 is prevented from falling off. The bead portion 8 can be formed smoothly by the pipe guide portion 5 formed on the side opposite to the insertion side of the pipe 1. Further, the formed bead portion 8 is provided with the escape recess 6.
It does not spread more than necessary because it is positioned at

As described above, the connection of the pipe 1 to the joint member 2 having the above-described structure can be easily performed only by the caulking operation without the need for the brazing operation or the like.

[0018]

As is clear from the above description, according to the piping joint structure of the present invention, since the pipe guides are formed on both surfaces of the joint member, the pipe can be connected from any direction of the joint member. It can be easily fitted. Further, when the open end of the pipe is crimped, the bead portion can be formed in the relief recess by easily expanding the remaining pipe guide portion, and the brazing operation is not required. Thus, simply
Not only can the pipe be fitted and integrated from either side of the joint member, but also one of the pipe guides can be used to facilitate the insertion of the pipe, and the other can be easily caulked. Therefore, the configuration is excellent in workability.

Further, since a plurality of reinforcing grooves which terminate at the parting line from at least one opening edge of the fitting hole are formed, no burr is generated in the reinforcing groove, and the inner peripheral surface of the fitting hole is formed. All burrs can be reliably removed only by reaming. Therefore, problems such as the intrusion of burrs into the pipe do not occur.

Further, since the parting line where the reinforcing groove terminates is formed so as to be displaced from one of the two surfaces of the joint member to the other surface, the joint member is securely held in the open mold. And it can be reliably taken out.

[Brief description of the drawings]

FIGS. 1A and 1B are a front view and a cross-sectional view showing a joint structure for a pipe according to the present embodiment.

FIG. 2 is a cross-sectional view showing a state where the pipes of the joint member of FIG. 1 are connected.

FIG. 3 is a schematic view of a mold showing a state in which the joint member of FIG. 1 is formed by die casting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pipe 2 ... Joint member 3 ... Fitting hole 4 ... Mounting hole 5 ... Pipe guide part 6 ... Relief recess 7 ... Reinforcement groove 8 ... Bead part

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16L 23/026 F16L 23/024 F16L 23/028

Claims (4)

(57) [Claims] 1. A piping joint structure in which an end of a pipe is fitted and integrated with fitting holes opened on both surfaces of a joint member, wherein the joint member is formed by die casting, and both openings of the fitting hole are formed. A pipe joint structure, wherein a pipe guide portion gradually expanding outward toward the outer diameter side and a relief recess formed further on the outer diameter side from the pipe guide portion are formed on the edge. . 2. The method according to claim 1, wherein a parting line of the mold is located in the fitting hole, and a plurality of reinforcing grooves extending from at least one opening edge to the parting line are formed. Piping joint structure. 3. The piping joint structure according to claim 2, wherein the reinforcing groove is provided from both opening edges of the fitting hole, and is formed so as to be shifted in a circumferential direction by a parting line. 4. The parting line at which the reinforcing groove terminates is formed so as to be shifted to one of the front surfaces from the center of the front and back surfaces of the joint member. Piping joint structure.