JP3229365B2 - Pipe end molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a pipe end used for a pipe end joint, and more particularly to a method of forming a pipe end mainly used for a refrigerant pipe of an automobile cooling device.

[0002]

2. Description of the Related Art Conventionally, in manufacturing a pipe end joint used for a refrigerant pipe of an automobile cooling device, a method is used in which a joint portion is previously cut as a separate part, and the pipe and the pipe are integrated by brazing or the like. Had been. On the other hand, there is a method of integrally molding the end of the pipe, but the molding has been performed by combining the plastic working in the axial direction and the rotational plastic working of the pipe to be processed.

[0003]

According to the conventional manufacturing method described above, the brazing process using a combination with a cut product requires a large number of processing steps, and each step must be performed by a plurality of processing machines. As a result, the productivity is low and the equipment is large, so that there is a problem that the price of the product is high, which is not suitable for mass production.

[0004] In the above-described manufacturing method, the plastic processing using the combination of the axial direction and the rotational processing also has a much higher productivity than the former, but the forming process is separated. In rotational plastic working, there is a defect that the work is peeled off, and it is difficult to stabilize the processing conditions and the like for maintaining the quality, and it is difficult to control the quality.

Accordingly, it is an object of the present invention to provide a method of forming a pipe end which has good quality, is easy to manufacture, can be mass-produced, and can be manufactured with a small number of facilities, and a press forming punch used therefor. Is to do.

[0006]

According to the present invention, a raw pipe is connected.
The first expansion process, which expands while expanding radially outward,
Pressing the first expanded portion formed in the first expanding step
A flange portion forming step of forming a flange portion by
Press the tube from the outside and press the flange from the end of the tube.
A step of shrinking the middle of the part inward, and
The pipe is pressed from the inside and the end of the raw pipe is connected to the contracted pipe section.
Ri second expanding process to tube expansion outside Tona up in the element
While the pipe is fixed to the clamp once,
Thus, a method for forming a pipe end characterized by performing processing according to the steps is obtained.

Further, according to the present invention, the tube end is formed.
In the method, the step of constricting comprises:
Shrinking part is formed by shrinking the middle of the flange part inward
And between the contracted tube portion and the flange portion.
At the position adjacent to one axial end of the flange,
The first cylindrical part formed with an outer diameter smaller than the flange part
A method of forming a tube end is provided, which includes forming .

Further, according to the present invention, the tube end is formed.
The method comprises the steps of:
Along with forming a cylindrical portion, the compressed tube portion and the first cylindrical portion
A method of forming a pipe end is provided, which includes forming a tapered surface therebetween .

Further, according to the present invention, the tube end is formed.
In the method, between the contraction step and the second expansion step
Between the contracted tube portion and the first cylindrical portion in a direction perpendicular to the axial direction.
A method for forming a tube end is provided, comprising a step of forming an extending step .

Further, according to the present invention, any one of the above-mentioned ones
In the method for forming a pipe end according to the above, the second pipe expanding step is performed in a
Expand the tube from the end of the tube to the middle of the tube.
To form a second expanded portion and the second expanded portion.
Adjacent to one end of the first cylindrical portion in the axial direction between the first cylindrical portion and the first cylindrical portion.
With a smaller outer diameter than the first cylindrical part.
A method for forming a tube end is provided, which includes forming the formed second cylindrical portion .

Further, according to the present invention, the tube end is formed.
In the method, the second expanding step includes the second expanding section and the second expanding section.
And the second tubular portion and the second expanded portion and the
Forming a tapered surface with the second cylindrical portion.
Thus, a method for forming a pipe end is obtained.

Further, according to the present invention, any of the pipes described above
In the method for forming a terminal, the second pipe expanding step includes the step
(2) extending perpendicularly to the axial direction between the expanded portion and the second cylindrical portion;
A step is formed, and the second tube is formed from an end of the raw tube.
Position adjacent to one axial end of the second cylindrical portion between
Smaller than the flange portion and from the second cylindrical portion.
To form a third cylindrical portion formed with a large outer diameter
Thus, a method for forming a pipe end characterized by having a process is provided.

Further, according to the present invention, the tube end is formed.
In the method, the second expanding step corresponds to a final shape.
And a method for forming a tube end, characterized in that the method is performed using a shaped mold member .

[0014]

According to the present invention, the productivity and quality are dramatically improved by forming the workpiece by continuous plastic working in the axial direction by using a plurality of punches without detaching the workpiece, thereby forming an inexpensive pipe end. can do.

[0015]

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

FIG. 1 is a view showing a pipe end joint manufactured according to an embodiment of the present invention. As shown in FIG. 1, the pipe terminal joint 7 connects the pipe terminal 1, the half union 3 in which the other end pipe 2 to be connected to the pipe terminal 1 is accommodated at one end, and the pipe terminal 1 and the half union 3. Nut 5 for fixing
And

The pipe end 1 has, at one end, a flange portion 13 having an outer diameter larger than the outer diameter of the raw tube 10,
A first cylindrical portion 11 having a smaller outer diameter than the outer diameter of the raw tube 10 and a second cylindrical portion having a smaller outer diameter than the first cylindrical portion 11 and a smaller outer diameter than the raw tube 10; 0 with part 16 as the bottom
It has a ring housing groove and a third cylindrical portion 18 that forms one wall of the housing groove together with the second cylindrical portion 16 at the end of the pipe.

On the other hand, the half union 3 has a cylindrical shape, and has a flange 3a on one outer peripheral surface and a surface 3f on the other end.
A screw 3g is provided on the outer periphery between the flange 3a and the surface 3f. The inside of the flange 3a at one end of the half union 3 has a tube accommodating portion 3b whose outer diameter is substantially equal to the outer diameter of the mating tube 2, while the other end of the half union 3 has a tube accommodating portion 3b. The opposite side has a tube terminal accommodating portion 3c substantially equal to the outer diameter of the tube terminal 1, and a stepped portion 3d formed between the tube accommodating portion 3b and the tube terminal accommodating portion 3c so as to have a smaller diameter. Have. One end of the mating tube 2 is inserted into the tube accommodating portion 3b, abuts against the end face of the step portion, and is fixed to one end of the half union 3 by brazing or the like.

The pipe end joint 7 is assembled as follows. The O-ring 4 is attached to the groove having the second cylindrical portion 16 of the tube end 1 as the bottom, and the small-diameter portion 5
After the small-diameter portion 5a of the nut 5 provided with the a is attached, the tube end 1 is inserted into the tube end accommodating portion 3c of the half union 3 having the other end of the tube 2 at one end. Is fixed by screwing a screw 5b inside the nut 5 into a screw 3g provided around the nut.

2 to 10 are views showing a method of forming the tube end of FIG. This forming process is performed by a punch press. The forming process will be described below in the order of forming steps.

FIG. 2A is a diagram showing a raw tube forming the tube end 1. FIG. 2B is a diagram showing a clamp mechanism for fixing the raw tube 10 of FIG. 2A. FIG.
2 (a) and FIG. 2 (b), the clamp mechanism overlaps and forms a circular groove 23 in the axial direction.
The first and second clamp portions 22 are provided. Each of the clamp portions 21 and 22 has grooves 21a and 22b provided along the periphery of the circular groove 23 on the end surface. Raw tube 10
As shown in FIG. 2B, is clamped and fixed by the first and second clamps 21 and 22 from above and below. First, the workpiece of the raw tube is fixed by the clamp portions 21 and 22. In the subsequent steps, until the machining is completed,
The clamps 21 and 22 are not removed.

3 (a) and 3 (b) are views showing a first forming step. FIG. 3 (a) shows a processed product and FIG. 3 (b) shows a first forming step.
It is a figure showing the shape of the punch used for a forming process. When the raw tube 10 is sandwiched between the clamps 21 and 22 and pressed with the first punch from the right in the drawing to the opening of the raw tube 10 to expand the raw tube 10 radially outward, FIG. ).

FIGS. 4 (a) and 4 (b) are views showing a second forming step, and FIG. 4 (a) is a view showing a processed product and FIG. 4 (b) is a view showing the shape of a punch. The end of the raw tube 10 expanded to the outer diameter D1 in the first forming step is pressed by the second punch 40. In the second punch 40, a groove having a thickness y is formed by the hole 43 having the inner diameter D1 of the outer punch 42 and the inner punch 44. The end of the pipe 10 in which this groove is expanded (first expansion
Part) so that the flange 13 protrudes by upsetting. The first forming step, which is an expansion step, and the second forming step, which is an upsetting step, constitute a flange section forming step.

FIGS. 5 (a) and 5 (b) are views showing a third molding step, and FIG. 5 (a) shows a processed product and FIG. 5 (b) shows the shape of a punch used in the third molding step. FIG. Second
A third punch 5 is attached to the end formed to the outer diameter D1 in the molding process.
Press 0. The third punch has a structure in which the opening 53 has a hole D1 and the inner diameter 54 has a hole D2 having a tapered surface 55 connecting them. An end portion (first expanded portion) 11 of the raw tube shown in FIG. 4 has a first cylindrical portion 11 'having an outer diameter D1 and a reduced tube portion 16 having an outer diameter D2 smaller than D1 and a tapered surface 15 connecting these. And molded into a shape having this is,
This is a preforming step for forming the shape in the next step.

FIGS. 6 (a) and 6 (b) are views showing a fourth forming step, and FIG. 6 (a) is a view showing a processed product and FIG. 6 (b) is a view showing the shape of a punch. In the third molding step, the fourth punch 60 is pressed against the end having the outer diameter D2, the tapered surface, and the outer diameter D1. The fourth punch 60 has a hole having an inner diameter D2. As shown in FIG. 6 (a), the end of the tube shown in FIG. 5 (a) is a stepped portion 17 perpendicular to the axial direction from the tapered surface 15.
A second cylindrical portion 16 ' having an outer diameter D2 is formed from the step portion 17 to the distal end portion. By reshaping the preformed shape, substantially half of the O-ring mounting groove is formed. The third forming step, which is the first preforming step, and the fourth forming step, which is the first shaping step, constitute a tube reducing step .

FIGS. 7A and 7B are views showing a fifth forming step. FIG. 7A is a view showing a processed product and FIG. 7B is a view showing the shape of a punch used in the fifth forming step. It is. In the fourth forming step, the fifth punch 70 is pressed against the end having the outer diameter D2, the step portion 17, and the outer diameter D1. Fifth punch 70
Is provided with a cylindrical tip 73 having a round tip surface 76, a large-diameter portion 74 having an outer diameter larger than the tip 73, and a tapered surface 75 connecting these. The tip of the shape shown in FIG. 6A is, as shown in FIG.
Second cylindrical portion 16 ' having an outer diameter D2 from the second cylindrical portion
Third cylindrical portion 18 having an outer diameter D3 wider than 16 ′
(A second expanded portion) and a shape having a tapered surface 19 continuous with the second cylindrical portion 16 ′ and the third cylindrical portion 18. This step is a preliminary molding for forming the O-ring fitting groove as in the third molding step.

FIGS. 8 (a) and 8 (b) are views showing a sixth forming step, and FIG. 8 (a) shows a processed product and FIG. 8 (b) shows a shape of a punch used in the sixth forming step. FIG. Fifth
In the forming step, a second cylindrical portion having an outer diameter D2 from the step 17
16 ', a third cylindrical portion 18 having a wide outer diameter D3 in diameter than the second cylindrical portion 16', the second cylindrical portion 16 'and a third cylindrical portion 1
The sixth punch 80 is pressed against the end having the tapered surface 19 continuous with the eighth punch 8. The sixth punch 80 has a shape having a small-diameter portion 84 with a rounded distal end surface 83 and a large-diameter portion 85 wider than this. At the distal end shown in FIG. 7A, as shown in FIG. 8A, a tapered surface 19 is formed on a stepped portion 20 perpendicular to the center axis direction, and a third cylindrical portion 18 is further defined. The second cylindrical portion 16 is defined by the steps 17 and 20. The fifth preforming step, which is the second preforming step, and the second preforming step
The second expanding step is constituted by the sixth forming step which is a shaping step.

FIG. 9 is a view showing an intermediate clamp used as an aid to the fifth and sixth molding steps which are performed continuously to the fourth molding step. As shown in FIG. 9, a first inner diameter surface 91 formed on one end side into which the flange portion 13 formed in the fourth molding step of FIG. 6 is inserted, a second inner diameter surface 92 having a diameter D1, and a diameter. It has a hole formed by a third inner diameter surface 93 having a diameter D2 and a fourth inner diameter surface 94 having a diameter D3 at the other end. At the time of the fifth and sixth molding steps following the fourth molding step, the intermediate clamp 9 shown in FIG. 9 is attached to the end of the pipe, and the fifth punch 70 shown in FIG. 8B, and further pressing the sixth punch 80 shown in FIG. 8B, thereby forming the pipe end joint 1 having the same shape as that of FIG.
Is obtained, and a more accurate pipe end joint can be formed than that obtained by the forming step using only the fifth and sixth punches without using the intermediate clamp.

[0029]

As described above, according to the present invention, a method of forming a pipe end used for a pipe end joint which has good quality, is easy to manufacture, can be mass-produced, and can be manufactured with less equipment. And a forming punch used therefor.

[Brief description of the drawings]

FIG. 1 is a diagram showing a pipe end joint manufactured according to the present invention.

FIG. 2 (a) is a view showing the material of the tube end of FIG. 1 (a),
(B) is a figure which shows the clamp for fixing the raw material of (a).

FIG. 3 is a view showing a first forming step of the pipe end of FIG. 1;
(A) shows the processed product, and (b) shows the shape of the punch used in the first forming step.

FIG. 4 is a view showing a second forming step of the pipe end of FIG. 1;
(A) shows the processed product, and (b) shows the shape of the punch used in the second molding step.

FIG. 5 is a view showing a third forming step of the pipe end of FIG. 1;
(A) shows the processed product, and (b) shows the shape of the punch used in the third molding step.

FIG. 6 is a view showing a fourth molding step of the pipe end of FIG. 1;
(A) shows the processed product, and (b) shows the shape of the punch used in the fourth molding step.

FIG. 7 is a view showing a fifth forming step of the pipe end of FIG. 1;
(A) shows the processed product, and (b) shows the shape of the punch used in the fifth molding step.

FIG. 8 is a view showing a sixth forming step of the pipe end of FIG. 1;
(A) shows the processed product, and (b) shows the shape of the punch used in the sixth molding step.

FIG. 9 is a view showing an intermediate clamp used as an auxiliary in the fifth and sixth forming steps shown in FIG. 6 of the tube end of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pipe terminal 2 Counterpart pipe 3 Half union 3a Flange 3b Pipe accommodating part 3c Tube terminal accommodating part 3f surface 3g Screw 4 O-ring 5 Nut 7 Tube terminal joint 10 Elementary tube 11 1st expanded part 11 '1st cylindrical part DESCRIPTION OF SYMBOLS 13 Flange part 15 Tapered surface 16 Contracted tube part 16 '2nd cylinder part 17 Step part 19 Tapered surface 20 Step part 21 First clamp part 22 Second clamp part 23 Groove 30 First punch 40 Second punch 44 Internal punch 50 third punch 53 opening 54 inner diameter portion 55 taper surface 60 fourth punch 70 fifth punch 73 tip portion 74 large diameter portion 75 taper surface 80 sixth punch 83 tip end surface 84 small diameter portion 91 first inner diameter surface 92 second inner diameter surface

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B21D 41/00-41/04

Claims (8)

(57) [Claims] (1) Expanding a raw tube while expanding it radially outward.
A first expanding step for forming a pipe, and pressing the first expanding section formed in the first expanding step.
A flange portion forming step of forming a flange portion by pressing the raw tube from the outside and pressing a flange from an end of the raw tube
A tube-shrinking step of shrinking the middle of the part inward, and pressing the raw tube from the inside from the end of the raw tube
Wherein Ri second expanding process Tona of tube expansion halfway outside of the reduced pipe portion, while fixing the raw tube once the clamp, connecting
A method of forming a pipe end, characterized by performing processing in each of the successive steps . 2. A method for forming a tube end according to claim 1.
In the contraction step, the end portion of the raw tube is connected to the flange portion.
It is possible to form a constricted tube by shrinking partway inward.
The flange between the constricted tube portion and the flange portion
At a position adjacent to one axial end of the
Forming a first cylindrical part formed with a smaller outer diameter
A method of forming a pipe end, comprising : 3. A method for forming a pipe end according to claim 2.
In the contracting step, the contracting portion and the first cylindrical portion are formed.
And a tape between the contracted tube portion and the first cylindrical portion.
A method for forming a pipe end, comprising forming a flange surface . 4. A method for forming a pipe end according to claim 2 or 3.
In the above, between the contraction step and the second pipe expansion step,
Extends vertically between the compression tube portion and the first cylindrical portion in the axial direction
A method for forming a tube end, comprising a step of forming a step . 5. The method according to claim 2, wherein
In the method for forming a pipe end, the second expanding step includes the step of:
Expand outward from the end of the raw tube to the middle of the contracted tube
This forms the second expanded portion and the second expanded portion and the front portion.
Adjacent to one axial end of the first cylindrical portion between the first cylindrical portion and the first cylindrical portion.
Formed with a smaller outer diameter than the first cylindrical part
Forming a formed second tubular portion . 6. A method for forming a pipe end according to claim 5.
The second expanding step includes the second expanding section and the second expanding section.
Forming a tubular portion, the second expanded portion and the second tubular portion;
And forming a tapered surface between them . 7. A method for forming a tube end according to claim 5 or 6.
In the second pipe expanding step, the second pipe expanding section and the second pipe expanding section
Forming a step extending vertically in the axial direction between the second cylindrical part
Along with the gap between the end of the raw tube and the second cylindrical portion
At the position adjacent to one axial end of the second cylindrical portion, the franc
Outer diameter smaller than the outer diameter and larger than the second cylindrical part.
A method for forming a tube end, comprising a step of forming a third cylindrical portion formed in advance . 8. The method for forming a pipe end according to claim 1 to claim 7.
Wherein the second pipe expanding step includes a mold member corresponding to a final shape.
A method for forming a pipe end, wherein the method is performed using a pipe.