JPH09280456A - Manufacture of a trident form pipe and air conditioner using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate cutting work such as deburring, and manufacture at a low cost a trident form pipe having high performance and reliability, by inserting a molded punch from the opening of the overhung part of the trident form pipe after overhang molding, and manufacturing a projection generated by the overhang molding in such a manner that it is push-press molded by using this molded punch. SOLUTION: In this trident form pipe 1, both sides of a linear pipe end surface and a plastic fluid body are simultaneously push-press molded so as to mold an overhung part 1a, thereby a projection 1b can exist in an anti-overhung side pipe inner diameter. When this projection 1b is removed, the molded punch 3 is inserted to the trident form pipe after the trident form pipe 1 is set between molded dies 2 in a divided structure concerning projection adjustment. As to this punch 3, its end 3a is formed into an R shape along a pipe inner diametral shape, and as to the dies 2, a dug in part 2a is arranged in a part corresponding to the end 3a of the punch 3. Therefore, when the punch 3 is pressurized, the projection 1b is pushed to a dug in part 2a side, and the inside diameter of the pipe 1 can be formed into a smooth R shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an object to reduce the flow resistance of gas or liquid refrigerant flowing in a pipe constituting a refrigeration cycle of an air conditioner and the reduction of refrigerant noise due to the operation of the air conditioner. In particular, the present invention relates to a method of manufacturing a three-way pipe used for branching or joining the flows of the refrigerant, and an air conditioner using the same.

[0002]

2. Description of the Related Art In a generally known refrigerating cycle of an air conditioner, an example of a mounting structure of a three-way pipe that links a single pipe and a double pipe constituting the refrigerating cycle is shown in FIG. 1 of JP-A-5-164348. Are known.

The above-mentioned three-pronged pipe is used for the purpose of branching and flowing the refrigerant according to the application in the structure of the refrigeration cycle in which an appropriate amount of the refrigerant is enclosed.

A conventionally known three-pronged pipe is disclosed in JP-A-4-14.
As described in JP-A-5291 and JP-A-4-145292, a hole is formed in the middle of a straight pipe, and another pipe is brazed to this hole to be joined, or manufactured by the process shown in FIG.
It is known that a fluid such as lead which is heated to a high temperature as shown in FIG. 16 is filled and pressurized in the straight pipe and a part of the straight pipe is plastically worked to manufacture. Of these, generally, fabrication by plastic working as shown in FIG. 7 to FIG. 16 with few working steps is generally performed.

That is, in FIGS. 7 to 16, 11 is a straight pipe, 12 is a plastic fluid material made of a substance having a high plastic fluidity such as heated lead, 13 is an overhanging mold, and 14 is a three-pronged pipe.

That is, the linear pipe 11 having an appropriate size shown in FIG.
As shown in FIG.
Is filled in another step (not shown), and a part of the straight pipe 11 can be molded as shown in FIG. As shown in FIG. 10, the overhang molding die 13 has a divided structure, and the straight end 13a for accommodating the outer diameter 11b of the straight pipe 11 and both directions of the overhang molding 13b and the straight end 13a orthogonal to the straight end 13a
It is composed of a pin 13c that press-molds c.

A straight pipe 11 is attached to the overhang molding die 13.
After setting the pipe, as shown in FIG. 11, the pipe end surface 11c
Together with the plastic fluid material 12 filled in the straight pipe 11, the compression pins 13c are simultaneously compression-molded from two directions as indicated by white arrows, and as shown in FIG. , The plastic flow material flows in while projecting a part of the straight pipe 11,
The overhanging portion 14a is plastically formed on a part of the
4 is molded.

[0008] A trifurcated pipe 14 having a suitable overhanging dimension.
The plastic fluid such as lead in the inner diameter of the is removed in another step (not shown) involving heating, and then the tip of the overhanging portion 14a is cut and opened as shown in FIG. As shown in the front view of FIG. 13 (a) and the side view of FIG. 13 (b), they are arbitrarily bent and connected to other pipes as a part of the cycle pipe required to branch the flow of the refrigerant. Formed possible.

The above-mentioned conventionally known method for forming a three-pronged pipe is
As shown in FIG. 11 and FIG. 12, the buckling portion 14b appears on the opposite side of the overhanging portion 14a in the process of pressurizing the pipe end surface 11c with the pressing pin 13c and performing a series of contraction and expansion molding.
Moreover, due to the influence of the frictional force between the plastic fluid material 12 and the inner surface of the pipe when the plastic fluid material 12 flows to the overhanging portion 14a as indicated by the arrow, the projection 14c is generated in the straight portion of the three-pronged pipe 14, The projection 14c is to change the flow of the gas or liquid refrigerant, which is originally desired to be a laminar flow, into a turbulent flow as shown by an arrow when used in the cycle pipe of the air conditioner as shown in FIG. As a result, there is a possibility that problems may occur, such as a decrease in performance due to an increase in the flow resistance of the refrigerant and a noise caused by a large flow noise of the refrigerant.

Therefore, it is necessary to solve these problems of the air conditioner, and before the bending of the three-pronged pipe 14, the projection 14c is formed by mechanical cutting as shown in FIG.
Had to be removed to obtain a smooth inner surface.

This mechanical cutting is carried out by drilling 15 or a reamer (not shown) as shown in FIG. 15, but the burr produced by the processing shown in FIG. After adding mechanical cutting from the opposite side and repeating this multiple times to remove burrs, visually confirm the presence of residual burrs or chips, and in addition, check the pipe wall thickness due to bending of the drill. It requires extremely complicated work such as checking whether or not there is a decrease, resulting in a rise in processing cost and a decrease in reliability.

[0012]

In the conventional method for removing the projection in the pipe, which relies on the drilling or reaming, the generation of chips and burrs and the cutting of the bent portion of the drill reduce the wall thickness of the pipe. Due to such reasons, there are problems such as soaring manufacturing cost, performance deterioration, and reliability deterioration, and the present invention eliminates these drawbacks, and a trifurcated pipe improved in cost, performance and reliability is provided. To provide efficiently.

[0013]

SUMMARY OF THE INVENTION The present invention replaces the conventionally known mechanical cutting process with a plastic forming (pressing) process, and eliminates incidental work such as deburring and chip removal.

That is, the molding punch is inserted from the opening of the overhanging portion of the three-pronged pipe after the overhang molding, and the projection formed by the overhang molding is press-molded using this molding punch to manufacture the projection and the protrusion. It is a low-priced, three-pronged pipe with stable performance and high reliability that eliminates cutting processes such as deburring.

[0015]

1 to 6 show an embodiment of the present invention.

Here, 1 is a trifurcated pipe, 2 is a molding die, and 3 is a molding punch.

FIG. 1 shows a three-pronged pipe 1 in which an overhanging portion 1a is obtained by the same method as a conventionally known overhanging method. That is, since both sides of the straight pipe end surface and the plastic fluid are pressed almost at the same time to form the overhanging portion 1a (similar to FIG. 11 in detail), the projection 1b is present in the inner diameter of the non-overhanging side pipe.

2 to 5 show the protrusion 1b according to the present invention.
The removal method is related to.

That is, after the three-pronged pipe 1 shown in FIG. 1 is set between the molding dies 2 having a divided structure for correcting the protrusions as shown in FIG. 2, the molding punch 3 is inserted as shown in FIGS. 2 and 3. . At this time, the tip of the forming punch 3 has an R shape along the inner diameter of the pipe as shown in the arrow B of FIG. Further, as shown in FIG. 3, the molding die 2 is provided with a dug portion 2a at a portion corresponding to the tip portion 3a of the molding punch 3.

FIG. 5 shows a state in which the molding punch 3 is pressed as indicated by the white arrow and the projection 1b of the inner diameter of the three-pronged pipe 1 is pressed by a combination of the respective members of FIGS. 2 to 4. It is shown. That is, the protrusion 1b that was on the inner diameter of the trifurcated pipe 1 is extruded toward the engraved portion 2a of the molding die 2, so that the inner diameter of the trifurcated pipe 1 is smooth or smooth.

According to the above-mentioned embodiment, the removal of the projection on the inner diameter of the pipe is replaced by the conventional cutting work by a simple press work, and the tact is greatly shortened, and the generation of chips, burrs and burrs is caused. It is possible to eliminate all of them, and further, it is possible to eliminate the visual check process by a person for confirming the foreign matter.
Further, when the three-pronged pipe of the present embodiment is used as a part of the refrigeration cycle pipe of the air conditioner as shown in FIG. 6 after appropriately bending and forming as in the conventional case, gas or gas as shown by an arrow in FIG. The liquid refrigerant makes a laminar flow and quietly flows, the increase in the flow resistance that hinders the performance is eliminated, and the abnormal generation of the flow noise due to the disturbance of the flow of the coolant can be suppressed.

As a result, by using the trifurcated pipe according to the present invention, it is possible to supply the customer with an air conditioner of low cost, high performance and high reliability.

[0023]

According to the present invention, the removal of the projections on the inner diameter of the pipe can be changed from the conventional cutting process to the plastic forming (pressing) process, and the additional work such as deburring and chip removal can be eliminated. That is, by inserting the molding punch from the opening of the overhang portion of the three-pronged pipe after the overhang molding by the heated fluid material, and by using this molding punch to press-mold the protruding portion generated by the above overhang molding It is possible to provide a trifurcated pipe with stable performance and high reliability at a low price, while eliminating the need for cutting such as protrusions and deburring. As a result, when this three-pronged pipe is used as a part of the refrigeration cycle piping of an air conditioner, the gas or liquid refrigerant makes a laminar flow and quietly flows, and the increase in flow resistance that hinders the performance is eliminated. It is possible to suppress the abnormal occurrence of the circulation sound due to the turbulence of the flow. As a result, low cost, high performance and high reliability air conditioners can be supplied to customers.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of the shape of a trifurcated pipe before processing according to the present invention.

FIG. 2 is a schematic perspective view showing an example of a structure of a mold for molding a protrusion inside a three-pronged pipe.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a view taken in the direction of arrow B in FIG. 3;

FIG. 5 is a cross-sectional view showing an example of a pipe inner diameter projection elimination forming method.

FIG. 6 is a cross-sectional view illustrating the flow state of the refrigerant using the three-pronged pipe of the embodiment.

FIG. 7 is a perspective view showing an example of a straight pipe before forming a three-pronged pipe.

FIG. 8 is a cross-sectional view showing a state in which a straight pipe before forming a trifurcated pipe is filled with a plastic fluid material.

FIG. 9 is a perspective view and a vertical sectional view showing an example of a conventional three-pronged pipe forming method.

FIG. 10 is a sectional view taken along line CC of FIG. 9;

FIG. 11 is a sectional view showing an example of a molded state of a trifurcated pipe.

FIG. 12 is a side sectional view showing a state in which the tip of the overhanging portion of the three-pronged pipe is cut.

13A and 13B are a front view and a side view showing a state in which a pipe end is bent after forming a three-pronged pipe.

FIG. 14 is a cross-sectional view illustrating an example of the flow state of the refrigerant in the stretch-molded state.

FIG. 15 is a cross-sectional view showing an example of conventionally known protrusion removal processing of a three-pronged pipe.

FIG. 16 is a cross-sectional view showing an example of conventionally known protrusion removal processing of a three-pronged pipe.

[Explanation of symbols]

1 ... Trifurcated pipe, 1a ... Overhang part, 1b ...
Protrusion, 2 ... Molding die, 2a ... Engraved part,
3 ... Molding punch, 3a ... Tip of molding punch.

Claims (2)

[Claims] Claim: What is claimed is: 1. A straight pipe is filled with a fluid material made of a substance having plastic flowability, and a part of the pipe is set in an overhang molding die capable of being overmolded, and plastic flow at both ends of the pipe and inside the pipe. The material is pressed at substantially the same time, a part of the pipe is stretched in a direction perpendicular to the axial center of the pipe, the plastic flow material is removed from the inside of the pipe, and then the tip of the stretched portion is cut and opened. In this state, a punch having a semi-circular shape corresponding to the shape of the inner diameter of the pipe at the tip is provided on the opposite side of the overhanging portion inside the pipe with a projection generated by the plastic deformation of the pipe and the friction caused by the flow of the plastic flow material. And a semi-circular bottom portion corresponding to the shape of the pipe outer diameter, and pressing the above-mentioned projection portion with a die having a dugout formed in a part of the bottom portion thereof, the pipe inner diameter on the side of the overhanging portion is linear. Alternatively, a method of manufacturing a three-pronged pipe characterized by being formed into a smooth curved shape. 2. A straight pipe is filled with a fluid material made of a substance having plastic flowability, and a part of the pipe is set in an overhanging mold capable of being overmolded, and plastic flow at both ends of the pipe and inside the pipe. The material is pressed at substantially the same time, a part of the pipe is stretched in a direction perpendicular to the axial center of the pipe, the plastic flow material is removed from the inside of the pipe, and then the tip of the stretched portion is cut and opened. In this state, a punch having a semi-circular shape corresponding to the shape of the inner diameter of the pipe at the tip is provided on the opposite side of the overhanging portion inside the pipe with a projection generated by the plastic deformation of the pipe and the friction caused by the flow of the plastic flow material. And has a semi-circular bottom that corresponds to the shape of the pipe outer diameter,
And, after pressing the projection portion using a die having a dugout formed in a part of its bottom, to produce a three-pronged pipe in which the pipe inner diameter on the side of the overhanging portion is formed into a straight or smooth curved shape, An air conditioner characterized by being used for connecting pipes constituting an evaporator or a condenser, which is a main component of a refrigeration cycle of an air conditioner.