JP2009078275A - Method and device for working branch hole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of working a branch hole, in which a flange is easily formed on the branch hole formed on a metallic pipe. <P>SOLUTION: A lower hole 8 is bored in the middle of the metallic pipe 1. Then, a pin 17 is inserted into the lower hole. After that, the pin 17 is brought into contact with the inside of the lower hole and moved in the forming direction of the hole while rotating the pin, so that the flange 4 as well as the branch hole 3 is formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a branch hole formed in the middle of a metal pipe, and more particularly to a method and apparatus for processing a branch hole in a metal pipe of an automotive air conditioner.

The branch hole formed in the middle of the metal pipe is used for the purpose of extracting the fluid flowing in the metal pipe and the pressure. As a method of processing this branch hole, as shown in Patent Document 1, there is a method in which a pilot hole is formed in a metal pipe and brazed after a nipple or a branch pipe is fitted.
Reality 5-14075

Further, as shown in Patent Document 2, there is a method of making a pilot hole in the middle of a metal pipe, expanding one end of the branch pipe, abutting the branch pipe so as to cover the pilot hole, and brazing. .
JP-A-5-172372

  However, in the said patent document 1, since the end of a nipple or a branch pipe protrudes in a metal pipe, it will reduce a passage area and increase a passage resistance. In addition, burrs are generated due to the processing of the pilot holes, and the burrs are dropped or diffused into the fluid passing through the metal pipe, becoming so-called contaminants, which may lead to malfunctions such as malfunction of the compressor. Moreover, in the said patent document 2, at the time of processing of a pilot hole, deformation | transformation of a metal pipe is easy to occur, and from the deformation | transformation, a flow-path area decreases, a passage resistance increases, Furthermore, a brazing area is wide, and brazing is difficult, There was a drawback that it was difficult to obtain sufficient brazing strength.

Therefore, a method has been developed (Patent Document 3) in which a flange 15 is provided at the edge of the branch communication hole 14 of the metal pipe 11 and the pipe joint member 12 is fitted to the flange 15 so as to cover the outer periphery. ing. According to Patent Document 3, the pipe joint member 12 does not protrude into the metal pipe, the passage area is not reduced, the difficulty of welding is eliminated, and the pipe for the refrigerant is effective. ing.
2-114289

  However, it is only described that the flange processing of the metal pipe is performed by bulging. In the process of forming a flange by this bulge processing, first, the metal pipe is set in a mold in which a portion that swells in the middle of the metal pipe is formed. Then, both ends of the metal pipe are sealed, and liquid is injected into the metal pipe. Next, the pressure in the pipe is increased until the metal pipe expands. Then, the metal pipe is compressed by applying a force in the direction of shortening the axial direction, and the expansion of the middle part of the metal pipe is completed. The flange portion is formed by the above process.

  In this way, in bulging, expensive equipment that applies pressure to the liquid or compresses it by applying force in the axial direction of the metal pipe and strict process control are required. The provided branch hole cannot be easily formed.

  Therefore, in the present invention, it is an object to form a flange in the branch hole by a simple method without using expensive bulging.

  A branch hole machining method according to the present invention is a method of machining a branch hole for branching in the middle of a metal pipe. First, a pilot hole is formed in the radial direction of the metal pipe, and the pilot hole is formed inward in the hole formation direction. A flange is formed in the prepared hole by extruding from the outside so as to bulge outward (Claim 1).

  As a result, the branch hole formed in the middle of the metal pipe is formed together with the flange when the pilot hole is pushed out so as to bulge from the inside to the outside. Processing becomes easy.

  The specific manufacturing method is to insert a pin into the pilot hole from the outside in the hole forming direction, to contact the pilot hole from the inside while rotating the pin, and to move in the hole forming direction. (2).

  Thereby, the branch hole with a flange can be easily formed using a pilot hole by moving to a hole formation direction, rotating a pin.

It is preferable that the tip of the pin bends at a constant angle. Further, it is preferable that the inner peripheral surface which assists the formation of the flange by the pin and is effective for the shape forming of the flange is manufactured using a fixing jig having a cylindrical shape. Thereby, when fitting a branch pipe to the flange of a branch hole, the fitting operation | work can be made smooth and weldability is improved.

  The branch hole machining apparatus according to the present invention comprises at least means for fixing a metal pipe, means for forming a pilot hole in the metal pipe, and means for expanding the pilot hole from the inside to the outside to form a flange, The branch hole machining method according to any one of claims 1 to 4 is performed (claim 5).

  Thereby, the apparatus which enforces the branch hole machining method of any one of Claim 1 thru | or 4 mentioned above can be provided. That is, a jig for fixing a metal pipe, a drill for making a pilot hole in the metal pipe, and a pin for forming a flange using the pilot hole are used to process a branch hole with a flange.

  Preferably, the means for fixing the metal pipe has a function of regulating the outer diameter of the flange (Claim 6), the outer diameter dimension of the flange is regulated, and the fitting with the metal pipe to be externally fitted is made smooth. The clearance between the flange and the metal pipe can be kept appropriate.

  As described above, according to the present invention, it is very easy to form a flange in a branch hole formed in the middle of a metal pipe. That is, it is performed by extruding the pilot hole so that it bulges from the inside to the outside, and it is not necessary to use an expensive device such as a conventional bulge processing, which can contribute to a reduction in cost (claim) Item 1).

  Moreover, the concrete processing method can form a branched hole with a flange by inserting a pin into a prepared hole formed in a metal pipe, rotating the pin, making contact from the inside, and moving it in the hole forming direction. Therefore, it is sufficient to use a machine for rotating the pin, and it can be easily manufactured at low cost.

  In addition, in the processing of flanges using pins, using a fixing jig with a cylindrical inner peripheral surface is effective in shaping the flange shape, and the clearance with the branch pipe fitted to this flange is properly managed. Thus, the insertion can be made smooth and the quality during welding can be improved.

  Further, the branch hole processing apparatus of the present invention includes a means for fixing a metal pipe, a means for forming a pilot hole in the metal pipe, and a means for bulging the pilot hole from the inside to the outside to form a flange. It is possible to provide an inexpensive apparatus that can implement the branch hole machining method of the present invention with a simple structure (claim 5). By providing the metal pipe with a function of restricting the outer diameter of the flange to the fixing means, there is an advantage that the number of parts does not increase (Claim 6).

  FIG. 1 shows a state in which a branch pipe 2 is connected to a metal pipe 1 by welding. The branch pipe 2 is fitted into a flange 4 of a branch hole 3 formed in the metal pipe 1 from outside and welded 5 from outside. ing. This branch hole 3 does not protrude into the metal pipe 1, does not decrease the flow path cross-sectional area, and does not increase the flow resistance.

  In FIG. 2, a branch hole processing apparatus 10 used for carrying out the method for processing the branch hole 3 is shown. The apparatus 10 includes a processing part 11 attached to a drilling machine (not shown) and a fixing jig 12 for fixing the metal pipe 1.

  The processing section 11 is fixed to a drilling machine and is subjected to screw processing, a mounting plate 14 fixed to the tip of the shaft 13, and a drilling tool (for example, hanging downward on the lower surface of the mounting plate 14). A drill 16 and a flange forming pin 17 are provided.

  The drill 16 is rotated by a motor 18, and the pin 17 is also rotated by a motor 19. The processing unit 11 is moved in the vertical direction by a drilling machine (not shown) and is also appropriately moved in the front-rear direction.

  The fixing jig 12 includes an L-shaped pedestal 21 composed of a rail portion 22 extending in the horizontal direction and a nip fixing portion 24 erected vertically at one end thereof, and a nip that moves the rail portion 22 of the pedestal 21. It is comprised by the movable part 25, and the said metal pipe 1 can be clamped because the clamping movable part 25 slides in the front-back direction.

  The sandwiching and fixing portion 24 and the sandwiching movable portion 25 constituting the sandwiching portion 23 have semicircular portions 26a and 26b for sandwiching the metal pipe 1 in the horizontal direction, and cylindrical circular holes 28 in the vertical direction. It has semicircular portions 29a and 29b that constitute it. The circular hole 28 acts to regulate the outer diameter of the flange.

  3 to 8, the above-described method of processing the branch hole 3 is shown and illustrated in time series. First, as shown in FIG. 3, the metal pipe 2 made of aluminum or the like is fixed to the holding portion 23 of the fixing jig 12 described above.

  That is, the metal pipe 1 moves the sandwiching movable part 25 along the rail part 22 and is sandwiched between the semicircular part 26 b of the sandwiching movable part 25 and the semicircular part 26 a of the sandwiching fixing part 24. The metal pipe 1 has a diameter of about 12 mm and a thickness of about 1.0 to 2.0 mm.

  When the fixing of the metal pipe 1 is completed, the drill 16 is lowered, the metal pipe 1 such as aluminum is drilled through the circular hole 28, and the pilot hole 8 is drilled in the metal pipe. The diameter of the pilot hole 8 is about 6 mm.

  Next, the machining process is shown in FIG. 4, and a pin 17 whose tip is bent at a certain angle is inserted into the prepared hole 8. The pin 17 has a diameter of about 2 mm and is made of a material harder than aluminum, such as iron. The upper end of the pin 17 is attached to the processing portion 11 that gives vertical movement and rotation. The motor 19 provided in the part 11 can be rotated.

  Since the tip of the pin 17 is bent at a certain angle, the pin 17 is inserted from the center position at the time of insertion as shown in FIG. 5 enlarged, and then moved to the center position of the pilot hole 8 at the time of insertion.

  The inserted pin 17 is moved in the formation direction of the pilot hole while rotating at about 500 revolutions per minute, and is brought into contact with the inside of the pilot hole 8 as shown in FIG. Then, while the pin 17 is gradually rotated, the pin 17 is moved to the outside of the pilot hole 8 along the formation direction of the pilot hole, and as shown in FIG. 7, the diameter is increased while forming the flange 4, and as shown in FIG. The branch hole 3 is formed and the flange 4 is formed. The inner diameter of the branch hole 3 is about 8 mm, the outer diameter of the flange 4 is about 10 mm, the flange thickness is about 1.0 to 2.0 mm, and the flange height is about 2.5 mm. It will be.

  When the flange 4 is formed, the outer side of the flange 4 comes into contact with the circular hole 28 formed in the holding portion 23, and the clearance with the circular diameter of the branch pipe 2 to be inserted can be appropriately managed.

  As described above, in the present invention, the processing of the branch hole 3 for connecting the branch pipe to the metal pipe through which a liquid such as a refrigerant flows can be manufactured at a lower cost and easier than the bulge processing conventionally employed. is there.

It is sectional drawing which welded the branch pipe using the branch hole manufactured by the branch hole processing method which concerns on this invention. It is a perspective view of the branch hole processing apparatus which is invention for enforcing the branch hole processing method. Thru (Excluding Fig. 5) is a time series drawing of the branch hole machining method. FIGS. A and b are explanatory views when the pilot hole is processed. FIGS. A and b are explanatory views showing a state where a pin is inserted into the prepared hole. It is explanatory drawing (enlargement) at the time of pin insertion to a pilot hole. It is explanatory drawing which shows the time of a pin contact | abutting to the inner side of a pilot hole, and a process start. It is explanatory drawing of the state which has given the flange process using the pilot hole. It is explanatory drawing of the state in which the branch hole with a flange was formed in the metal pipe with the pin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal pipe 2 Branch pipe 3 Branch hole 4 Flange 5 Welding 8 Pilot hole 10 Branch hole processing apparatus 11 Process part 12 Fixing jig 14 Mounting plate 16 Drilling tool (drill)
17 pin 21 L-shaped base 22 rail part 23 clamping part 24 clamping fixed part 25 clamping movable part 28 circular hole

Claims (6)

In the method of processing a branch hole for branching in the middle of a metal pipe,
A branch hole machining method characterized in that a pilot hole is formed in a radial direction in a metal pipe, the pilot hole is extruded so as to bulge from the inside to the outside in the hole forming direction, and a flange is formed in the pilot hole. .   A flange is formed by inserting a pin into the pilot hole from the outside in the hole forming direction, contacting the pilot hole from the inside while rotating the pin, and moving the pin in the hole forming direction. The branch hole machining method according to claim 1.   The branch hole machining method according to claim 2, wherein the tip of the pin is bent at a constant angle.   The fixing pipe whose inner peripheral surface is cylindrical is installed in the metal pipe with the pilot hole as the center, and the outer diameter of the flange to be formed is regulated. Branch hole machining method.   5. The apparatus according to claim 1, further comprising: means for fixing at least the metal pipe; means for forming a pilot hole in the metal pipe; and means for expanding the pilot hole from the inside to the outside to form a flange. The branch hole processing apparatus characterized by implementing the branch hole processing method of description.   6. The branch hole machining apparatus according to claim 5, wherein the means for fixing the metal pipe has a function of regulating an outer diameter of the flange.

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