KR100320558B1 - Three-way pipe - Google Patents

Abstract

The present invention relates to a three-way pipe used for dividing a refrigerant flow into two, or joining into one, etc., wherein the pipe wall is thinned by being cut too much by the occurrence of burrs or debris and deformation or bending of the drill. In order to solve the problems such as increase in cost, deterioration of performance and deterioration of reliability, a pipe is placed in a molding die that can be filled with a fluid made of a material having plastic fluidity inside a straight pipe and extrude a part of the pipe. Press-molding the plastic fluids filled at both ends of the pipes and the pipes at about the same time, deforming a portion of the pipes to the extrusion section at right angles to the axis of the pipe, removing the plastic fluids from the pipe, and cutting the openings of the extrusion sections to open. In a three-way pipe formed by a three-way pipe, Due to the plastic deformation of the rod and the friction between the pipe and the circulating plastic fluid, the protrusions generated on the inner surface of the pipe at the position opposite to the extruded portion are pressed to substantially remove a portion of the inner surface of the pipe on the opposite side to the extruded portion. The outer surface of the pipe was formed so as to be flat and formed to protrude outward at a portion corresponding to the portion of the inner surface of the pipe.

In this way, by removing the protrusions on the inner surface of the three-way pipe by molding (pressing) instead of cutting, unnecessary work such as removal of debris or debris is unnecessary, and low cost, high performance and high reliability can be realized. have.

Description

Three Way Pipes {THREE-WAY PIPE}

The present invention relates to a three-way pipe used for branching into two, or joining into one, the flow flowing in a pipe constituting a cycle of an air conditioner.

In a refrigerating cycle of a generally known air conditioner, as an example of the attachment structure of a three-way pipe that connects (combines) a single pipe constituting the refrigerating cycle and two other pipes, Japanese Patent Laid-Open Publication No. Hei 5-164348 There is something like that shown in 1.

These three-way pipes are used for branching the refrigerant depending on the application in a refrigeration cycle in which an appropriate amount of refrigerant is enclosed.

The conventionally known three-way pipe is manufactured as follows. One method is to drill a hole in the middle (middle) of a straight pipe and solder another pipe to this hole, as disclosed in Japanese Patent Application Laid-Open No. 4-145291 and Japanese Patent Application Laid-Open No. 4-145292. It is produced by the process. Another method is to produce a three-way pipe by filling a plastic fluid such as heated lead under pressure in a straight pipe and plastically deforming a part of the straight pipe as shown in FIGS. 7 to 17. . Among these methods, as shown in Figs. 7 to 11, the latter method of using the molding process is generally performed because there are few processes.

More specifically, in Figs. 7 to 11, reference numeral 11 denotes a straight fluid pipe, 12 denotes a plastic fluid material made of a material rich in plastic fluidity such as lead, 13 denotes an extruding die, and 14 Is a three-way pipe.

As shown in FIG. 8, the plastic fluid 12 is filled in the separate process (not shown) in the inner space 11a of the linear pipe 11 of the appropriate dimension shown in FIG. Thereafter, as shown in FIG. 9, a straight pipe containing the plastic fluid 12 in an extrusion die 13 which can deform (extrude) a part of the straight pipe 11 through extrusion ( 11) is set. As shown in FIG. 10, the extrusion die | dye 13 has a straight part 13a which accommodates the outer diameter 11b of the straight pipe 11, and orthogonal to this straight part 13a (it extends perpendicularly). And pressing pins 13c disposed on each of both sides of the extruded portion 13b and the straight portion 13a and pressing the end face 11c of the pipe in both directions.

After setting the straight pipe 11 in the extrusion die 13, as shown by the white arrow with the plastic fluid 12 filled in the straight pipe 11 as shown in Figure 11 At the same time through the end face 11c the straight pipe 11 is compression molded by the pressing pin 13c. As shown in FIG. 11, the plastic fluid 12 is introduced while extruding a part of the straight pipe 11 into the extrusion part 13b perpendicular to the pressing direction. As a result, an extruded portion 14a is formed in a part of the straight pipe 11 by plastic deformation to produce a three-way pipe 14.

The three-way pipe 14 provided with the extruded portion 14a having a desired (appropriate) dimension is removed from another process (not shown), such as heating, by a plastic fluid such as lead in the three-way pipe 14. Thereafter, as shown in Fig. 12, the tip end of the extruded portion 14a is cut and opened. The three-way pipe 14 is optionally bent as shown, for example, in the front view of FIG. 13A and the side view of FIG. 13B. As a result, the three-way pipe 14 can be connected to another pipe as a part of the refrigeration cycle piping required to branch the flow of the refrigerant.

However, the conventional method of forming a three-way pipe has the following problems. As shown in FIGS. 11 and 12, in the series of processes of pressing the pipe end surface 11c by the pressing pin 13c and extruding it under pressure, the straight pipe 11 is opposite to the extrusion portion 14a. A portion of the bent portion 14b of () is shown. Further, as shown by the arrow, the linear fluid flow of the three-way pipe 14 is affected by the frictional force between the plastic fluid 12 and the pipe inner surface when the plastic fluid 12 is pressed to flow into the extrusion section 14a. The protrusion 14c is produced. As shown in Fig. 14, this projection 14c is a turbulent flow as indicated by the arrow indicating the flow of gas or liquid refrigerant, which is preferably laminar flow, when the three-way pipe 14 is used for the refrigeration cycle piping of the air conditioner. Change. As a result, problems such as performance degradation due to an increase in the flow resistance of the refrigerant and noise caused by turbulence of the refrigerant flowing through the three-way pipe (flowing through) occur.

On the other hand, the size of the projection 14c greatly depends on the frictional force between the plastic fluid 12 and the inner surface of the pipe. For example, when lead is used as the plastic fluid 12, the amount of frictional force changes with the heating of lead. That is, when the lead is sufficiently heated, the tip of the protrusion 14c does not become sharp, and when the lead is not heated, the tip of the protrusion 14c tends to spread and become sharp.

In order to solve the above problem, a recess is formed in the inner surface of the extrusion die 13 at a position opposite to the extrusion portion 14a perpendicular to the pressing direction, and the bending of the pipe straight portion generated at the time of molding is performed in the recess. A method of protecting the inner surface of a pipe from protruding to the inside by absorbing it is disclosed in Japanese Patent Laid-Open Publication No. Hei 1-255792 (see Fig. 15).

In the above-described method, the bending of the pipe straight portion due to the force acting on the axial pipe is absorbed to some extent by the recess, but the recess is inevitably generated at the position opposite to the extruded portion due to the compression of the pipe. It is not possible to sufficiently absorb the increase in wall thickness.

As the inner surface of the pipe protrudes (expands) toward the extruded portion, the increase in the pipe wall thickness as described above cannot be absorbed by the concave portion, which inevitably reduces the inner diameter of the pipe, thereby increasing the flow resistance of the refrigerant. Further, since the increase in the pipe wall thickness cannot be sufficiently absorbed and the inner diameter of the pipe decreases, friction between the plastic fluid such as lead in the pipe and the inner surface of the pipe increases. The projections generated by the friction become somewhat smaller depending on the presence or absence of the recesses, but the projections still cannot sufficiently remove the sound of the refrigerant flowing through the pipe in use.

Therefore, it has been desired to solve the above problems in air conditioners. Therefore, it was necessary to remove the projection 14c by mechanical cutting as shown in FIGS. 16 and 17 before bending the three-way pipe 14 to obtain a smooth inner surface.

This machine cutting process is performed using the drill 15 or a reamer (not shown), as shown in FIG. In this conventional method, however, burrs generated during the mechanical cutting process shown in FIG. 16 are removed by performing the mechanical cutting process again on the opposite side as shown in FIG. 17, and this mechanical cutting process is performed. Repeat this several times in the opposite direction to completely remove the bur, and visually check that the bur or debris (chip) still remains. Moreover, the operation which confirms whether the pipe wall (pipe thickness) became thin by the bending (bending) or deformation of a drill is also needed.

Such a complicated work resulted in an increase in manufacturing cost and a decrease in reliability.

Therefore, the conventional method of removing the projections in the pipe by the drill or the reamer is that the pipe wall can be thinned due to the occurrence of burrs or debris and the deformation or bending of the drill, resulting in thinner pipe walls. Has a problem of deterioration and reliability deterioration. That is, the conventional method of removing the protrusions generated during the extrusion process did not sufficiently solve these problems.

An object of the present invention is to solve the above problems in the prior art, to provide a three-way pipe efficiently manufactured by improving the cost, performance and reliability.

In order to achieve the above object, in the present invention, the mechanical cutting process performed by the conventional method is replaced by the molding process, thereby eliminating the side work such as burr removal and debris removal.

More specifically, a press punch is inserted through an opening of an extrusion section of a three-way pipe formed by extrusion, and pressed by the punch to remove protrusions generated during extrusion. As a result, cutting processing such as removing projections and burrs is unnecessary, and a three-way pipe with stable performance and high reliability can be supplied at low cost.

1 is a longitudinal sectional view showing an example of the shape of a three-way pipe before processing of the present invention;

FIG. 2 is a schematic perspective view showing an example of the structure of a forming die for pressing the projections generated in the three-way pipe; FIG.

3 is a cross-sectional view taken along the line II-II of FIG. 2;

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

5 is a cross-sectional view showing an example of a pressing method for removing projections on the inner surface of a pipe;

6 is a cross-sectional view for explaining the flow state of the refrigerant passing through the three-way pipe of the embodiment,

7 is a perspective view showing an example of a straight pipe before three-way pipe extrusion;

8 is a cross-sectional view showing a state in which a plastic fluid is filled in a straight pipe before three-way pipe extrusion;

9 is a perspective view and a longitudinal sectional view showing one example of a conventional method for manufacturing a three-way pipe;

10 is a cross-sectional view taken along the line X-X of FIG. 9;

11 is a sectional view showing one example of a forming process of a three-way pipe;

12 is a side cross-sectional view showing a process of cutting the tip of an extrusion part of a three-way pipe;

13A is a front view showing a state in which three branch ends of the manufactured three-way pipe are bent;

13B is a side view showing a state in which three branch ends of the manufactured three-way pipe are bent;

14 is a cross-sectional view for explaining one example of the flow state of the refrigerant passing through the three-way pipe after extrusion processing;

15 is a cross-sectional view showing one example of a structure in which a recess is provided in a conventional extrusion die;

16 is a cross-sectional view showing one step of a known conventional method for removing the projections generated in a three-way pipe by mechanical cutting;

17 is a cross-sectional view showing the following process of the known conventional method for removing the projections generated in the three-way pipe by mechanical cutting;

One embodiment of the present invention is shown in Figs.

In these figures, reference numeral 1 denotes a three-way pipe, numeral 2 a forming die, and numeral 3 a pressing punch.

The three-way pipe 1 shown in FIG. 1 has an extruded portion 1a formed by the same processing method as a conventionally known extrusion processing method. In other words, the extruded portion 1a is formed by simultaneously pressing with both sides of the end face of the straight pipe and the plastic fluid filled therein (see Fig. 11 for details of the extrusion processing). Thereby, the projection 1b exists in the inner surface (inner diameter) of the three-way pipe on the opposite side to the extrusion part 1a.

2 to 5 show a method of removing the protrusion 1b according to the present invention.

As shown in FIG. 2, the three-way pipe 1 shown in FIG. 1 is set in the groove part provided in the shaping | molding die 2 of the division structure which has the shape along the outer surface (outer diameter) shape of a pipe, and is suitable for protrusion correction. . Thereafter, the press punch 3 is inserted into the three-way pipe as shown in Figs. At this time, the tip 3a of the pressing punch 3 has a round shape along the inner diameter of the three-way pipe 1 as shown in FIG. 4 showing the case seen from the arrow B direction of FIG. Moreover, the recessed part 2a is provided in the groove part of the shaping | molding die 2 in the position corresponding to the front-end | tip 3a of the said press punch 3, as shown in FIG.

2 to 4, the forming die 2 is shown as a horizontal cutting die assembly. This molding die may use a vertical cutting die assembly.

Fig. 5 is a combination of the members set at each position of Figs. 2 to 4, wherein the projections 1b on the inner surface of the three-way pipe 1 are pressed by the pressing punch 3 as indicated by the white arrows. It shows the state of pressing. By this pressing, the projection 1b on the inner surface of the three-way pipe 1 is extruded (pushed out) to the recessed portion 2a side of the forming die 2, and the inner surface of the three-way pipe 1 is smooth. It forms a round shape.

According to this embodiment, the projection on the inner surface of the three-way pipe is removed by simple pressing (press) instead of conventional cutting. Therefore, the production time is considerably shortened, debris and burrs are not generated, and it is unnecessary to visually check whether foreign matter remains in the pipe. When the three-way pipe of this embodiment is properly bent and shaped as in the prior art, and then used as part of the refrigeration cycle piping of the air conditioner, as shown by the arrows in FIG. 6, the gas or liquid refrigerant quietly passes through the pipe while forming a laminar flow. Will flow. This can prevent an increase in flow resistance that can degrade performance, and can suppress abnormal generation of flow noise due to disturbance of the refrigerant flow.

As a result, by using the three-way pipe according to the present invention, it is possible to supply the user with a low cost, high performance and high reliability air conditioner.

As described above, according to the present invention, the removal of the projections on the inner surface of the three-way pipe is performed by forming (pressing) instead of the conventional cutting process, thereby making it possible to eliminate unnecessary work such as burr removal or debris removal. . That is, a pressing punch is inserted through the opening of the three-way pipe extrusion section after the extrusion molding using a heated plastic fluid material, and in order to remove the projections, the projections generated during the extrusion processing are pressed by using the punches in three directions. By manufacturing the pipe, it is possible to provide a three-way pipe with stable performance and high reliability at a low price while eliminating the need for cutting such as protrusion and burr removal. When the three-way pipe is used as part of a refrigeration cycle pipe of an air conditioner, gas or liquid refrigerant flows quietly through the pipe while forming a laminar flow. As a result, an increase in flow resistance that can degrade performance can be prevented, and an abnormal occurrence of flow noise due to disturbance of the refrigerant flow can be suppressed. As a result, a low cost, high performance and high reliability air conditioner can be supplied to the user.

Claims (2)

Filling a flow material made of a material having plastic fluidity into a straight pipe, and placing the pipe in a molding die capable of extruding a portion of the pipe, and filling the both ends of the pipe and the plastic fluid filled in the pipe. A three-way pipe formed by pressing at about the same time, deforming a portion of the pipe into an extruded portion in a direction perpendicular to the axis of the pipe, removing the plastic fluid from the pipe, and cutting the tip of the extruded portion to open it. To The three-way pipe presses the protrusions formed on the inner surface of the pipe at a position opposite to the extruded portion by the plastic deformation of the pipe and the friction between the pipe and the flowable plastic fluid, and the extruded portion Is formed so that a part of the inner surface of the pipe on the opposite side is substantially flat and is formed so that the outer surface of the pipe protrudes outwardly in a portion corresponding to the portion of the inner surface of the pipe, The method of claim 2 The protrusion is pressed using a punch and a die, The punch has a tip formed with a semi-circular cross section corresponding to the shape of the inner surface of the pipe, The die is a three-way pipe having a bottom portion corresponding to a shape of an outer surface of the pipe and a recess portion at a portion of the bottom portion facing the tip of the punch.

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