JP2881203B2 - Method and apparatus for forming deformed pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal pipe having, for example, a circular cross section, which is radially stretched by a split mold having a curved forming face inserted therein, so as to form a mold. The present invention relates to a method for forming a deformed pipe for forming a cross-sectional shape into an irregular shape such as an oval shape by deforming to conform to the shape, and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, there has been known an apparatus shown in FIGS. 7 to 9 which stretches a pipe in a radial direction by using a split mold to form the pipe into an irregular shape. In these figures, the forming apparatus 51 has a base plate 52 in the form of a rectangular plate. One end of the base plate 52 (the left end in FIG. 7) is open at the upper side and has a base at the lower end. -Spray-
Vertical groove 54 cut to a predetermined height from the upper surface of
A fixing block 53 having a central portion has a bottom end.
The groove 52a of the plate 52 is fitted to
It is fixed to the base plate 52 by bolts (not shown) screwed from the lower surface of the plate 52. The moving block 55 is lower in height than the fixed block 53,
A vertical groove 56 that opens upward is provided at the center. In the moving block 55, the width of the vertical groove 56 is the same as the width of the vertical groove 54 of the fixed block 53, and the vertical groove 56 is opposed to the vertical groove 54 of the fixed block 53 to form the base plate 52. Is mounted on the upper surface of the base plate 52, and is movable in a direction approaching or away from the fixed block 53 via a key 57 fixed to the upper surface of the base plate 52.

[0003] A push plate 58 having a shank 59 mounted on a press machine (not shown) at the upper center thereof is shorter in length than the base plate 52 and narrower in width than the base plate 52. ing. The push plate 58 has a longitudinal groove 58b formed on the lower surface of one end (the left end in FIG. 7) in the longitudinal direction thereof and parallel to the left end face 58a, and a first push rod 60 has an upper portion in the center of the transverse groove 58b. It is inserted. The upper surface of the first push rod 60 is fixed to the push plate 58 by an appropriate number of bolts 73 screwed from above the push plate 58. The first push rod 60 extends downward from the lower surface of the push plate 58 by a predetermined length, and can be fitted into the vertical groove 54 of the fixed block 53. The push plate 58 has a first push rod 6
A second push rod 61 having the same shape as the first push rod 60 is fitted on the lower surface opposite to the first push rod 60 at its upper part in a lateral groove 58c parallel to the lateral groove 58b.
8. The fixed mold 62 that supports the pipe P below the pressing plate 58 has a forming surface 62a formed in an arc surface having a diameter smaller than the diameter of the pipe P to be formed, and is horizontally positioned below the axis Cp. A lower surface 62b is formed. In this fixed mold 62, two vertical holes 63 are formed vertically from the upper part of the molding surface 62a provided on the outer peripheral surface to the center of the lower surface 62b. A suspension bolt 64 having a head 64a and a shaft portion 64b is inserted into each vertical hole 63, and the shaft portion 64b is inserted into the vertical hole 63.
Projecting downward through a hole formed in the bottom portion 63a of the base member. The compression spring 65 is fitted to the shaft portion 64b between the head 64a of the suspension bolt 64 and the bottom 63a of the vertical hole 63,
It acts to push up the suspension bolt 64. The fixed mold 62 has a predetermined gap between its molding surface 62a and the lower surface of the pressing plate 58, and its lower surface 62b is formed by a base plate.
It is arranged between the first push rod 60 and the second push rod 61 in parallel with the upper surface of the door 52, and one end surface thereof is connected to the inner surface of the fixed block 53 by a plurality of bolts 66.

A movable die 67 disposed below the fixed die 62.
Has a cross-sectional shape similar to that of the fixed mold 62, but the diameter of the outer peripheral surface, which is the molding surface, is smaller than the diameter of the outer peripheral surface (molding surface) of the fixed mold 62, and its length is shorter than the length of the fixed mold 62. Has become. In FIG. 7, the movable die 67 has a left shaft 68 projecting from an end surface thereof at a predetermined length on the left end side. The axis of the left shaft 68 is the axis C _{2 of the} movable die 67.
Is on an extension of On the right end side of the movable mold 67, there is an intermediate shaft portion 69 having a larger diameter than the left shaft portion 68. Outside the intermediate shaft portion 69, a right shaft portion 70 having the same diameter and the same length as the left shaft portion 68 is provided. Is formed. Axis of the intermediate shaft portion 69 and a right shaft portion 70 also on the extension of the axis C ₂ of the mobile 67. The movable die 67 has a molding surface 67a on its outer peripheral surface, and the molding surface 67a faces downward.
b is parallel to the lower surface 62b of the fixed mold 62,
The threaded portions of the shaft portions 64b of the suspension bolts 64 projecting downward from the lower surface 62b of the suspension bolt 64 are screwed. As described above, the movable mold 6 connected to the fixed mold 62 by the two suspension bolts 64 is provided.
In 7, the axis C ₁ of the fixed mold 62 is parallel to the axis C ₂ of the movable mold 67, and the lower surface 62 b of the fixed mold 62 and the upper surface 67 b of the movable mold 67 are parallel. A pair of lower push rods 71 disposed below the first push rod 60 and the second push rod 61 are block-shaped members having a rectangular cross section and a predetermined length, and the thickness thereof is the left axis of the fixed mold 62. The length of the portion 68 is the same as the length of the vertical groove 54 of the fixed block 53.
It is dimensioned to fit inside. The lower portion of the lower push rod 71 has an arc surface having the same diameter as the intermediate shaft portion 69 of the movable die 67, the lower portion has the same axis as the arc surface of the intermediate shaft portion 69, and the left shaft portion of the fixed die 62. A shaft hole 72 into which 68 can be inserted is formed.

In order to form the pipe P to be molded by the molding apparatus 51, the pipe P to be molded is fitted to the outside of the fixed die 62 and the movable die 67.
b and the upper surface 67b of the movable mold 67 are in close contact with each other by the action of a compression spring 65 that pushes up the suspension bolt 64. Conventionally, in fitting the molded pipe P to the fixed mold 62 and the movable mold 67, first, a press (not shown)
To raise the push plate 58 to a position where the lower end of the second push rod 61 is higher than the upper surface of the fixed die 62, and move the moving block 55 to the outside of the base plate 52 to move the base plate. -Had been removed from port 52. After the pipe P to be molded is fitted to the fixed mold 62 and the movable mold 67, the movable block 55 is returned to the original state, and the left and right shaft portions 68 and 70 of the movable mold 67 are moved down by the respective push rods 7.
One shaft hole 72 was fitted. When the moving block 55 is returned to the original state, the lower surfaces 62b at both ends of the fixed mold 62 are connected to the support surfaces 53a on both sides of the fixed block 53 and the moving block 5.
5 is supported by the supporting surfaces 55a on both sides. In this state, when the press machine is operated to lower the push plate 58,
The left and right first push rods 60 and second push rods 61 are pushed down against the urging forces of both compression springs 65, 65 in both vertical holes 63 of the fixed die 62, and the lower push rods 71, Since the movable die 67 is pushed down, the left shaft portion 68 and the right shaft portion 70 of the movable die 67 are pushed down and descend. Since the molded pipe P by the lowering of the mobile 67 is then pushed stretched plastically deforming the lower portion downwards, has been molded sectional shape profiled pipe P ₁ of the oval. Also, when the molded pipe P ₁ is removed from the fixed mold 62 and the movable mold 67 after the molding of the molded pipe P is completed, the push plate 58 is raised to raise the movable mold 67 and move the moving block. 55
Was removed from the base plate 52. As described above, in the conventional molding apparatus, every time one pipe is molded, there is a work of attaching and detaching the moving block to and from the base plate, and there is a problem that work efficiency is poor and productivity is not improved. In addition, since the time for pressing down the movable mold of the press is very short, there is a problem that springback occurs after molding and variations in product dimensions occur.

[0006]

An object of the present invention is to provide a molding apparatus in which a molded pipe can be inserted into or removed from the outside of a fixed mold or a movable mold without attaching or detaching components of the molding apparatus. It is an object of the present invention to shorten the preparation time for forming, thereby increasing the forming efficiency, and to eliminate the dimensional variation of the formed deformed pipe.

[0007]

An apparatus for forming a deformed pipe according to the present invention, which solves this problem, comprises a base plate.
A die plate fixed vertically to the plate, a fixed die having a curved molding surface on the outer peripheral surface, and fixed in a cantilever manner to the side surface of the die plate; A hydraulic cylinder device mounted on the side opposite to the molding surface, and an outer peripheral surface having a curved molding surface located on the opposite side to the molding surface of the fixed die, and a tip of a rod of the hydraulic cylinder device. And a movable type mounted on the unit.

[0008]

With the movable mold close to the fixed mold, a pipe to be molded is fitted to the outside of the fixed mold from the free end side of the fixed mold and set, and a hydraulic cylinder device mounted on the fixed mold is used. When the movable die is moved in a direction away from the fixed die, the pipe to be molded is elongated in the radial direction, and is formed into a predetermined shape by the respective molding surfaces provided on the outer periphery of the fixed die and the movable die. After molding,
When the movable die is brought close to the fixed die by the hydraulic cylinder device and the formed deformed pipe is moved to the free end side of the fixed die, the formed pipe is removed from the fixed die.

[0009]

1 to 6 show an apparatus for forming a deformed pipe according to the present invention. 1 to 3,
The rectangular base plate 1 is a plate-like member placed on a work table or the like. One side of the base plate 1 is A plate 2 which is vertical and has a predetermined height is fixed. Fixed type 3
Is a member of a predetermined length having on its outer peripheral surface a forming surface 3a having a diameter smaller than the diameter of the pipe P having a circular cross section fitted on the outside thereof, similarly to the conventional fixed mold. A lower surface 3 parallel to the axis C
b is formed. The fixed mold 3 has a lower surface 3b.
A cylinder case mounting hole 4 having a predetermined depth is formed in the longitudinal direction. The cylinder case 5 is a block-shaped member that is fitted into the cylinder case mounting hole 4 and is formed to the same length as the fixed mold 3. In the embodiment, two (2) piston holes 6 are provided at predetermined intervals along the longitudinal direction of the fixed mold 3. Place the upper part of the cylinder case 5 on the cylinder
When fitted into the case mounting hole 4, the lower portion protrudes below the lower surface 3b of the fixed mold 3 by a predetermined length. The cylinder case 5 is provided with mounting bolts 7 (see FIG. 1) inserted from below the cylinder case 5 into a suitable number of bolt holes vertically opened in a place where the piston hole 6 is not provided. Are shown only one).

An upper oil passage 14 is formed in the fixed mold 3 from one end face 3c toward the upper center of the piston holes 6, 6, and the upper oil passage 14 is connected to each piston by a communication passage 15. It communicates with the hole 6. Cylinder case 5
A pair of lower oil passages 16 are opened along the longitudinal direction from the end surface 5b on the same side as the end surface 3c of the fixed mold 3 at the lower portion of the fixed die 3. It communicates with the lower part on both sides of each piston hole 6.

The movable mold 17 disposed below the fixed mold 3 also has an arc-shaped molding surface 1 on the lower outer peripheral surface in the same manner as the conventional one.
7a is formed, and the upper surface 17b is planar. This movable mold 17 is different from the conventional mold and has the same length as the fixed mold 3. The upper surface 17b has a rod insertion hole 1 into which the rod portion 8a of the piston 8 is inserted.
8 is opened to a predetermined depth. At both ends in the longitudinal direction of the movable mold 17 and at the center in the width direction,
A square groove 19 having the same depth is formed in the direction of the rod insertion hole 18, and a pin hole 20 is formed at an inner end of the square groove 19 in parallel with the upper surface 17 b and the rod insertion hole 18 is formed. It is opened to penetrate. This mobile mold 17
The rod portions 8a of the pistons 8 of the fixed die 3 are inserted into the respective rod insertion holes 18, and the lower surfaces of the rod portions 8a are opened in the rod portions 8a in a state of contacting the lower surfaces of the rod insertion holes 18. When the connecting pin 22 is inserted into the pin hole 21 and the pin hole 20 of the movable die 17, the movable die 17 is connected to the fixed die 3.

As described above, the movable die 17 is mounted on the lower surface of the fixed die 3 via the cylinder case 5, and a plurality of the fixed die 3 are provided on the inner surface of the upper part of the die plate 2. Is fixed to the die plate 2 in a cantilever manner. in this way,
One end of a fixed mold 3 is mounted on a vertically provided die plate 2 with a cantilever, and a molding surface 3a of the fixed mold 3 is formed.
The cylinder case 5 is mounted on the opposite side of the cylinder case 5 and a movable die 17 is mounted on each rod portion 8a of a plurality of pistons 8 fitted in the piston holes 6 of the cylinder case 5. This is a characteristic part of the invention. As shown in FIG. 6, the die plate 2 communicates with the upper oil passage 14 and the lower oil passages 16, 16 of the fixed die 3, and these oil passages are connected to the oil pump 26 of an oil pump 26 to be described later. 1st oilway 27 and 2nd
Connection portions 25 for connecting to the oil passages 28 are provided respectively. The oil pump 26 has an oil discharge passage 30 connected to a first oil passage 27 and a second oil passage 28 via a switching valve 29, and a high-pressure relief valve 31 connected to the oil discharge passage 30.
However, a low-pressure relief valve 32 is provided in the second oil passage 28, respectively.

In order to form the deformed pipe P ₁ by the above-described deformed pipe forming apparatus A, as shown in FIG.
The switching valve 29 is set to the position shown in FIG. 6, and the piston 8 is moved to the rising end to position the movable mold 17 at the rising end. Next, a pipe P to be formed is fitted to the outside of the fixed mold 3 and the movable mold 17 from the free end of the fixed mold 3 (the part opposite to the die plate 2), and the tip of the pipe P approaches the die plate 2. Then, setting of molding is performed. At the time of this setting, as shown in FIG. 2, a guide block 34 is attached to a reinforcing plate 33 fixed to one side of the die plate 2, and the side surface of the pipe P to be formed is brought into contact with the guide block 34. axis C ₁ of the fixed mold 3 with the axis Cp of the molded pipe P
Positioning them substantially on a vertical plane allows smooth molding and increases molding accuracy. Next, by switching the switching valve 29 to supply the pressure oil to the upper oil passage 14 and discharge the pressure oil from the lower oil passage 16, both pistons 8 are pushed down and the molding surface 17 a of the movable mold 17 is formed. After coming into contact with the lower inner peripheral surface of the pipe P, the pipe P descends sequentially and pushes the molded pipe P downward. At this time, the lower surfaces of both rod portions 8a respectively press the bottoms of the rod insertion holes 18 of the movable die 17 to push down the movable die 17. As the movable mold 17 descends, the pipe P to be molded is gradually elongated downward, and the upper side thereof is plastically deformed along the molding surface 3a of the fixed mold 3 and the lower side thereof is formed of the movable mold 17. It is plastically deformed along the surface 17a.
The portion located in the middle of 7 is elongated in a plane (see FIG. 3). When the piston 8 reaches the bottom dead center, the molding is completed, and the molded pipe P having a circular cross section as shown in FIG. 4 is transformed into a modified pipe P ₁ having an oval cross section as shown in FIG. Molded. Thereafter, the switching valve 29 automatically switches to the state shown in FIG. 6, and the movable mold 17 reaches the rising end and stops. When this occurs, the profiled pipe P ₁ which is molded, which together with the force stretching radially does not act, the predetermined space between the bottom of the profiled pipe P ₁ and mobile 17 is formed When the shaped pipe P ₁ is moved to the free end of the fixed mold 3, the shaped pipe P ₁ is removed from the fixed mold 3. As described above, unlike the conventional molding apparatus, the pipe can be attached to and detached from the fixed mold without attaching and detaching the components constituting the molding apparatus.

Further, at the time of forming the deformed pipe P ₁ ,
The fixed mold 3 and the movable mold 17 act on each other in a direction in which the opposing members are separated from each other. for orthogonal to the axis line C ₁ of the molding surface 3a, the bending mode is the fixed die 3 - does not act as a reinforcement. Therefore, it is not necessary to particularly increase the mounting strength of the fixed die 3 to the die plate 2. In addition, since the pipe to be formed is plastically deformed by using the hydraulic pressure, the springback that is slightly restored to the original shape side after forming is reduced, and the forming accuracy is increased.

By changing the ratio of the diameter of the molding surface 3a of the fixed die 3 to the molding surface 17a of the movable die 17, or by changing the amount of movement of the movable die 17, the shape of the pipe to be molded can be easily changed. There are advantages that can be done. The shape of each of the molding surfaces 3a and 17a does not necessarily have to be a circular arc surface, but may be a generally curved surface.

[0016]

(1) A pipe is fitted from the free end side of the fixed mold to the outside of the fixed mold without removing the components of the molding apparatus at all, or the free end of the fixed mold is formed after molding. Since the pipe can be moved to the side and removed therefrom, the preparation time for forming the pipe is significantly reduced, and as a result the forming efficiency is increased. (2) Unlike press molding, since the pipe is plastically deformed by oil pressure, the springback after molding is reduced, and the dimensional variation of the molded product is reduced, and the molding accuracy is increased. (3) Since the hydraulic cylinder device for generating the deforming force of the pipe is mounted on the fixed type which is fixed to the die plate in a cantilever manner, the deforming force acting on the movable type and the fixed type, and the countermeasure thereof. The forces cancel each other and the direction of this deformation force is along the axis of the molding surface of the stationary mold. For this reason, since this deformation force does not act as a bending moment on the fixed die, it is not necessary to particularly increase the mounting strength of the fixed die to the die plate.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a pipe forming apparatus of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a sectional view taken along line XX of FIG. 1 in a state where the movable mold 17 is located at a lower end.

FIG. 4 is a perspective view of a pipe to be molded P.

5 is a perspective view of a profiled pipe P ₁ molded.

FIG. 6 is a hydraulic circuit diagram for operating the pipe forming apparatus of the present invention.

FIG. 7 is a partially cutaway front view of a conventional pipe forming apparatus.

FIG. 8 is a left side view of a conventional pipe forming apparatus.

FIG. 9 is a right side view of a conventional pipe forming apparatus.

[Explanation of symbols]

A: Pipe forming device C ₁ : Fixed type axis C ₂ : Moving type axis Cp: Shaping pipe axis P: Shaping pipe P ₁ : Deformed pipe 1: Base plate 2: Die plate 3: Fixed die 3a: Molding surface of fixed die 5: Cylinder case (hydraulic cylinder device) 8: Piston (hydraulic cylinder device) 17: Moving die 17a: Molding surface of mobile die

Claims (2)

(57) [Claims] 1. A fixed mold having a curved molding surface on an outer peripheral surface and fixed in a cantilever manner to a side surface of a diplate fixed vertically to a base plate; The outer peripheral surface has a curved molding surface located on the opposite side to the molding surface of the fixed die, and the distal end of the rod of the hydraulic cylinder device fixed to the opposite side to the molding surface of the fixed die. Using the movable mold to be mounted, with the movable mold close to the fixed mold, fit the pipe to be molded outside of the fixed mold from the free end side of the fixed mold and set it, and fix the movable mold The molded pipe is separated from the mold, and the molded pipe is moved to the free end side of the fixed mold while the moving mold is close to the fixed mold so that it can be removed from the fixed mold. Method of forming a deformed pipe. 2. A die plate fixed vertically to a base plate, and a curved molding surface on an outer peripheral surface.
A stationary die fixed to the side surface of the die plate in a cantilever manner, a hydraulic cylinder device mounted on the opposite side of the molding surface of the stationary die, and an outer peripheral surface opposite to the molding surface of the stationary mold. And a movable die attached to the tip of the rod of the hydraulic cylinder device.