JPH0438888Y2 - - Google Patents

Description

[Detailed explanation of the idea] Industrial applications The present invention relates to a pipe bender device.

Conventional technology Some pipe bender devices are
As shown in the publication, the axial middle part of a pipe as a workpiece is held between fixed blocks fixed to the apparatus main body, and one axial end of the pipe is held between a first roll fixed to the apparatus main body and this as a center. A core metal is inserted into the pipe from one end of the pipe, and the second roll
There is a structure in which the pipe is bent by operating a movable arm to which a roll and a core metal are attached, and by the cooperation of the fixed block, the first roll, the second roll, and the core metal.

Incidentally, it has been considered that automobile pipe parts, such as exhaust pipes, which are automobile engine parts, may be made of stainless steel to reduce the weight of the parts without compromising their rigidity or durability. However, pipe parts are bent with a small radius of curvature due to the location of the parts (minimum bending).
There are times when you have to. This minimal bending process is expressed as, for example, R/d=1.0, where R is the curvature at the center line of the pipe and d is the outer diameter of the pipe.

Problems to be Solved by the Invention In the pipe bender device described above, the position of the core bar relative to the first roll and the second roll can be adjusted before bending. During the bending of the pipe around the first roll, the position of the core metal relative to the first roll and the second roll remains stationary. For this reason,
Using the pipe bender device described above, the position of the core metal was adjusted and the aforementioned extremely small bending process with R/d = 1.0 or less was performed, and the processing conditions were as shown in Fig. 6 A, B, and C. As a result, the desired bent product could not be obtained. In the case shown in FIG. 6A, the bent outer wall a recedes inward, and the hollow hole in the bent portion has a flat cross section. The one in FIG. 6B has cracks on the bent outer wall b. 6th
The one shown in Figure C has wrinkles on the bent inner wall c. Not only B, but also A and C are not preferable because they increase the resistance when flowing fluid through the pipe.

Therefore, the present invention provides a pipe bender device that can overcome the above-mentioned problems even in extremely small bending operations where R/d=1.0 or less.

Means for Solving the Problems: A fixed block having a split type structure that is attached to the apparatus main body and holds the axially intermediate part of the pipe as a workpiece, and a fixed block that is rotatably connected to the tip of the block and that holds the axially intermediate part of the pipe as a workpiece. A movable block having a split mold structure into which one end in the center direction is loosely fitted, a pressing block inserted from the tip thereof and placed opposite to one end of the pipe, and a position at which the movable block starts bending when attached to the main body of the device. a first driver member that rotates from the bending start position to the bending end position; and a first driver member that pushes the pressure block so as to push one end of the pipe toward the intermediate portion when the movable block rotates from the bending start position to the bending end position. 2 driver members, and a metal core movably inserted into the bent portion of the pipe.

Function: One end of a straight pipe is bent in advance and a notch is formed so that it slopes from the outer wall side to the inner bent wall side. The middle part of this pipe is held between fixed blocks, and one end of the pipe is loosely fitted into a movable block. At this time, one end of the pipe should be set so that the longer axial length of the pipe will be on the outside during bending, and the shorter axial length will be on the inside during bending. is set. Then, with the pressing block inserted, the movable block is moved from the bending start position to the bending end position using the first driver member. Then, as the movable block moves, one end of the pipe is pushed in by the pressure block, and the inner wall surface of the bent part of the pipe is flattened by the core metal, and the pipe is bent around the connection part between the fixed block and the movable block. It will be done.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

As shown in Figures 1 to 5, this pipe bender device generally consists of a fixed block 1 and a movable block 2.
, a pressing block 3 , a first driver member 4 , a second driver member 5 , and a core bar 6 .

Here, since a press machine is used in this embodiment, the fixed block 1 is attached to the lower holder 7 as the main body of the device, and is divided into a first pipe holding member 10 and a second pipe holding member 11. Constructed of type. The first pipe holding member 10 is fixed to the lower holder 7, and a receiving groove 10a having a substantially semicircular cross section is formed on the side surface of the second pipe holding member.
The second pipe holding member 11 is the first pipe holding member 1
0 with a bolt 12, and a receiving groove 11a having a substantially semicircular cross section is formed on the side surface of the first pipe holding member. After placing the intermediate part of the pipe 8 in the receiving groove 10a of the first pipe holding member 10, the second pipe holding member 11 is fastened with the bolt 12 to the first pipe holding member 10, so that the pipe 8 is placed in the receiving groove 10a, 11a. It is designed to hold the

The movable block 2 is rotatably attached to the tip of the fixed block 1, and has a split mold structure into a first movable member 20 and a second movable member 21. 1st
The movable member 20 has a pin 2 attached to the first pipe holding member 10.
3 are connected, and a recess 24 for attaching the second movable member 21 is cut out in the rear portion of the pin 23 connection side. This recess 24 has a second end that is longer than one end of the pipe 8 held between the fixed block 1.
The movable member has a side surface, and a groove 20a having a substantially semicircular cross section that is continuous with the receiving groove 10a of the first pipe holding member 10 is formed on the side surface of the second movable member. A hole 20b connected to the groove 20a is formed in the front half of the first movable member 20. Second movable member 2
A groove 21 having a substantially semicircular cross section is formed on the side surface of the first movable member 1.
A is formed. These grooves 20a and 21a connect the first movable member 20 and the second movable member 21 to the bolt 25.
When the pipe 8 is removably attached with
The hole has a diameter slightly larger than the outer diameter of one end, and is formed into a hole into which one end of the pipe 8 is loosely fitted.

The pressing block 3 is slidably inserted into the hole 20b from the tip of the movable block 2, and is a sleeve arranged from the hole 20b into the grooves 20a, 21a and facing one end of the pipe 8. 30, and a roller 31 connected with a pin 32 to the tip of the sleeve 30 that protrudes from the tip of the movable block 2.
It is made up of.

The first driver member 4 is a ram 9 as a main body of the device.
The downward movement of the ram 9 pushes the abutment member 26 provided on the first movable member 20 of the movable block 2, and moves the movable block 2 to the bending start position shown in FIG. It rotates around the pin 23 from the position shown in FIG. 2 to the bending end position shown in FIG.

The second driver member 5 is disposed in front of the portion of the lower holder 7 where the fixed block 1 is disposed, and when the movable block 2 rotates from the above-mentioned bending start position to the bending end position, it moves one end of the pipe 8 to the intermediate position. This is to push the pressing block 3 so as to push it toward the front side.
Specifically, the second driver member 5 is the movable block 2
It has an arcuate cam surface 5a that slides against the roller 31 of the press block 3 as the press block 3 rotates. The radius of curvature of the cam surface 5a is set to gradually decrease from the bending start position to the bending end position of the movable block 2 when viewed from the center at the pin 23 which is the connecting part between the fixed block 1 and the movable block 2. has been done. Further, an operating rod end 51 of a cylinder assembled to the lower holder 7 is attached to the front part of the second driver member 5, and is capable of reciprocating movement via a guide mechanism 52 when the cylinder is operated. . Also, when bending the pipe 8,
The second driver member 5 is held stationary at a predetermined position by a cylinder.

The core metal 6 is internally fitted into a receiving hole 30a formed in the shaft portion of the sleeve 30 of the pressing block 3 so as to be able to slide in the axial direction, and its tip end is inserted between the fixed block 1 and the movable block 2. Pin 23 which is the connecting part
, and is formed into an arcuate surface 6a shaped to follow the bending of the pipe 8. 30b is an elongated hole formed in the sleeve 30, and a protrusion 60 protruding from the rear side of the core metal 6 is inserted into this elongated hole 30b.
are fitted together, and work together with the protrusion 60 to prevent the core bar 6 from rotating in the circumferential direction. 6
Reference numeral 1 denotes a spring that urges the core metal 6 toward the rear of the sleeve 30.

According to the structure of the above embodiment, as shown in FIG. 5, one end of the pipe 8 as a straight workpiece is bent in advance to form a notch diagonally from the outer wall 8a side to the bent inner wall 8b side. put. As shown in FIG. 1, when the ram 9 is stopped at its upper limit of movement, the middle part of the pipe 8 is held between the fixed block 1 and one end of the pipe 8 is held between the movable block 2.
The groove 20a of the first movable member 20 and the second movable member 2
It loosely fits into the groove 21a of No.1. At this time, pipe 8
At one end, the part where the axial length of the pipe 8 is longer (the part on the outer wall 8a side) becomes the outside during bending, and the part where the axial length of the pipe 8 is shorter (the part on the inner wall 8b side) ) is set so that it is on the inside during bending. Then, the tip 6a of the core bar 6 is placed within one end of the pipe 8 at the position of the pin 23, which is the connecting part between the fixed block 1 and the movable block 2, and the sleeve 30 of the pressing block 3 is brought into contact with one end of the pipe 8. While the rams 9 are in contact with each other, the ram 9 is moved downward, and the first driver member 4 is moved to move the movable block 2 around the pin 23 from the bending starting position shown in FIG. 1 to the bending start position shown in FIG. Rotate to the bending end position shown in . Then, as the movable block 2 rotates, the pressing block 3 is pressed by the arcuate cam surface 5a of the second driver member 5 and pushes in one end of the pipe 8, thereby breaking the thin wall of the bent outer wall 8a of the pipe 8. In addition, the inner wall surface of the bent portion of the pipe 8 is flattened by the core metal 6 to prevent wrinkles from forming on the bent inner wall 8b of the pipe 8. The pipe 8 is connected to the fixed block 1 and the movable block 2 while preventing the hollow hole of the bent portion of the pipe 8 from flattening.
It is bent as shown in FIG. 2 around the pin 23 which is the connection part with the holder. Moreover, the excess amount due to the flattening of the bent inner wall 8b of the pipe 8 is absorbed by the gap d existing between the notch formed at one end of the pipe 8 and the sleeve 30. After stopping the ram 9 at the upper limit of movement in the state shown in FIG. 2, the second pipe holding member 11 and the second movable member 21 are separated from the first pipe holding member 10 and the first movable member 20, respectively. By removing and taking out the bent pipe 8 from the first pipe holding member 10 and the first movable member 20, one cycle of bending the pipe 8 is completed.

Note that the present invention is not limited to the above embodiment, and although not shown in the drawings, for example, movable blocks 2 are provided on both sides of the fixed block 1, and pressing blocks 3, 1st
By providing the driver member 4, the second driver member 5, and the core bar 6, both ends of the pipe 8 can be
It can be bent simultaneously during the bending process of the cycle, or the second driver member 5 can be constructed as a cylinder installed across the movable block 2 and the pressing block 3, or the movable block 2 can be bent with a spring, cylinder, etc. after the bending process is completed. It is also possible to perform automatic return using the actuator. Furthermore, in some cases, when the pipe 8 is bent only at one end, the core bar 6 may be positioned at the bent portion of the pipe 8 from the other end of the pipe 8 held by the fixed block 1. .

Effects of the invention As described above, according to the invention, one end of the pipe is pushed in with a pressure block while the pipe is being bent to prevent thinning of the bent part of the pipe, and a core metal is used to prevent wrinkles and hollows in the bent part of the pipe. This has the practical effect of preventing flattening of the parts. Moreover,
When we performed extremely small bends of R/d = 1.0 or less on stainless steel pipes, we were able to overcome the disadvantages of conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the present invention in a pipe bending start state, and FIG. 2 is a partially cutaway front view showing the same embodiment in a pipe bending finish state. , FIG. 3 is an exploded perspective view of the main parts of the same embodiment, FIG. 4 is a sectional view taken along the - line in FIG. 1, and FIG. 5 is an axial view of one end of the pipe before bending. FIG. 6, which is a vertical cross-sectional view taken in section along the line, is an explanatory view of the conventional operation. 1...Fixed block, 2...Movable block, 3
... Pressing block, 4 ... First driver member, 5
... Second driver member, 6 ... Core metal, 7 ... Lower holder (device main body), 8 ... Pipe, 9 ... Ram (device main body).

Claims (1)

[Scope of utility model registration request] A fixed block having a split type structure is attached to the apparatus main body and holds the axially intermediate portion of the pipe as a workpiece, and a split block is rotatably connected to the tip of the fixed block and loosely fits one end of the pipe in the axial direction. A movable block having a mold configuration, a pressing block inserted from the tip of the block and placed opposite to one end of the pipe, and a press block that is attached to the main body of the device and rotates the movable block from a bending start position to a bending end position. 1 driver member; a second driver member that pushes a pressing block so as to push one end of the pipe toward the intermediate portion when the movable block rotates from the bending start position to the bending end position; A pipe bender device comprising a core bar movably inserted into a part.