JPH0790289B2 - Bending method and device - 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 and apparatus for bending a pipe or the like.

[0002]

2. Description of the Related Art A typical prior art is Japanese Patent Publication No. 1-472.
It is disclosed in Japanese Patent Publication No. 49. In this prior art, FIG.
As shown in FIG. 3, while the rotary die 3 having the curved portion 1 and the linear portion 2 is rotationally driven in the arrow 4 direction, the tube 5 which is a longitudinal body.
While being supported by the support die 6 and pressed against the linear portion 2 by the movable die 7, the movable die 7 is bent at a predetermined angle, and then the movable die 7 is moved in a direction away from the rotary die 3 indicated by an arrow 8. Then, the load acting on the pipe 5 is released, the recovery strain of the pipe 5 is calculated, and then the movable die 7 is moved in the opposite direction of the arrow 8 again to move the pipe 5 to and from the linear portion 2. The rotary die 3 is additionally rotationally driven with the pinch sandwiched between them to bend the pipe 5, and thus the pipe 5 is plastically deformed by a desired angle.

[0003]

However, in the prior art shown in FIG. 7, the movable die 7 is separated from the straight portion 2 in the direction of the arrow 8 after the pipe 5 is bent by a predetermined angle. The load that is displaced and acts on the pipe 5 is once released, so that the pipe 5 is separated from the bending portion 1. After that, the movable die 7 again moves in the direction opposite to the arrow 8 to move the pipe 5
Is sandwiched between the straight portion 2 and the straight portion 2, and a gap is formed between the curved portion 1 and the tube 5 as indicated by reference numeral d1 in FIG.
Therefore, there is a problem that the pipe 5 cannot be bent along the curved portion 1 with high accuracy.

An object of the present invention is to provide a bending method and apparatus capable of bending a long body such as a pipe into a desired shape with high accuracy.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a longitudinal die is pressed against a rotary die having a curved portion, and the rotary die is rotated to bend the longitudinal die at a predetermined angle along the rotary die. First, the first elastic force F1 of the longitudinal body is measured when the pressing force of the longitudinal body on the rotary die is zero, and the longitudinal body is rotated while the longitudinal body is in contact with the curved portion. The second elastic force F2 is measured by displacing in a direction away from the mold by a predetermined displacement amount, and the longitudinal body is moved based on the first and second elastic forces F1 and F2 and the predetermined displacement amount. The bending method is characterized in that an additional angle Δθ2 to be bent is calculated from the predetermined angle, and bending is performed while pressing the longitudinal body by the additional angle Δθ2 against the rotary die. .

Further, according to the present invention, a rotary die having a curved portion and a linear portion connected to the curved portion, a support die for supporting and guiding a longitudinal body by the rotary die, and a rotary die being separated from and approaching the linear portion. A movable die that is movably provided, a first drive means that rotationally drives a rotary die, a second drive means that drives the movable die in a direction of approaching and separating from a linear portion, and a force that a longitudinal body acts on the linear portion is detected. First detecting means, a second detecting means for detecting a force exerted by the longitudinal body on the movable die, an angle detecting means for detecting a rotation angle of the rotary die by the first driving means, and first and second
Responsive to the outputs of the detecting means and the angle detecting means, the rotary die is rotated by a predetermined angle by the first drive means, and then the second drive means moves the movable die in a direction away from the rotary die. 1 force F detected by the second detecting means when the force detected by the detecting means becomes zero
1 and the additional angle Δθ2 obtained by calculation based on the force F2 detected by the second detection means when the movable die is further displaced by the second drive means by a predetermined displacement amount in the separating direction. And a control means for rotating the rotary die by the first drive means while pressing the longitudinal body against the linear portion of the rotary die again by the second drive means.

[0007]

According to the present invention, the longitudinal body is supported and guided by the supporting die along the rotary type curved portion and the linear portion, and the movable body is pressed against the linear portion at a desired angle, for example, 9
Bending is performed at 0 degree, and then the movable die is moved in a direction away from the rotary die to measure the force exerted by the longitudinal body on the movable die when the force exerted by the longitudinal body on the linear portion is set to zero,
After that, the force F acting on the movable die by the longitudinal body when the movable die is further displaced in the separating direction by a predetermined displacement amount
2 is calculated, and an additional angle Δθ2, which is the recovery strain of the longitudinal body when the force acting on the longitudinal body by the movable die is released, is calculated and obtained. Bending is performed by this additional angle Δθ2 while pressing. As a result, the longitudinal body can be plastically deformed at a desired angle with high accuracy and bent.

[0008]

1 is a plan view of an embodiment of the present invention, and FIG. 2 is a sectional view taken along the section line ABCD in FIG. 1 (2). With reference to these drawings, a thin tube 11, which is a longitudinal body to be bent, is plastically deformed and bent by a bending device 12 by a target angle of 90 degrees. The rotary mold 13 has a vertical axis 14, and has a curved portion 15 for bending the pipe 11 and a linear portion 16 continuous with the curved portion 15 in a tangential direction. First detecting means 17 is provided to detect the force exerted by the pipe 11 on the straight portion 16.

The support die 10 which supports and guides the tube 11 to the rotary die 13 is arranged along the base 18 along the arrow 19 in FIG.
It can be moved in the opposite direction.

The rotary mold 13 is integrally provided with a bracket 20, and the bracket 20 has a double-acting hydraulic cylinder 2 attached thereto.
1 is connected, and the moving piece 22 is connected to the cylinder 21. The movable die 23 is in contact with the tube 11, and between the movable die 23 and the movable piece 22, a second detection means 24 for detecting the force exerted by the longitudinal body 11 on the movable die 23 is provided. First
The second detecting means 17 and 24 are, for example, strain gauges.

The rotary mold 13 is connected to an output shaft 26 of a driving means 25 such as a hydraulic motor that rotates the rotary mold 13. The drive means 25 is attached to the base 18. Output shaft 2
6, therefore an angle detection means 27 is provided for detecting the rotation angle of the rotary mold 13.

FIG. 3 is a simplified plan view showing the displacement angle detecting means 28 provided in association with the movable die 23.
The displacement angle detecting means 28 has a pair of detection pieces 29, 30 provided at intervals along the straight line portion 16, and thus the axial direction of the tube 11, and these detection pieces 29, 30 are arranged on the tube 11. By abutting the surface, the axis 1 of the tube 11
It is possible to detect the displacement angle Δθ formed by 1a and the linear portion 16.

FIG. 4 is a block diagram showing the electrical construction of the embodiment shown in FIGS. The processing circuit 31, which is realized by a microcomputer or the like, responds to the outputs from the first and second detection means 17 and 24, the rotation angle detection means 27, and the displacement angle detection means 28, and the cylinder 21
And controlling the drive means 25.

FIG. 5 is a flow chart for explaining the operation of the processing circuit 31 shown in FIG. When the pipe 11 is plastically deformed at a predetermined angle, for example, 90 degrees to be bent, first, as shown in FIG. 1 (1), the pipe 11 is supported by a supporting die 10 and a reaction force at the time of bending is applied. The tube 11 is clamped by the cylinder 21 between the linear portion 16 and the movable die 23 while being able to receive the pressure. In this state, the process moves from step n1 to step n2, and the rotating die 13 is rotationally driven by the driving means 25 as indicated by reference numeral 32 in FIG. 1 (1). As shown in FIG. 3, the rotation is performed by a predetermined rotation angle α (90 degrees in this embodiment as described above). In this way, the pipe 11 is bent along the rotary die 13 while being pressed against the curved portion 15 and the straight portion 16 of the rotary die 13.

FIG. 6 is a graph showing the relationship between the rotation angle of the rotary die 13 and the force detected by the second detecting means 24. In step n3 of FIG. 5 described above, the cylinder 2
The moving die 23 is moved away from the rotating die 13 by 1 so that the force detected by the first detecting means 17 becomes zero (left in FIG. 1 (2), left in FIG. 2). Direction), and the force F1 detected by the second detection means 24 at that time is detected. In FIG.
For convenience of understanding, the characteristic when the force detected by the first detection means 17 becomes zero is shown.

Therefore, in step n4, the cylinder 21 is further contracted to displace the movable die 23 away from the rotary die 13 and, as shown in FIG.
The angle Δθ detected by the displacement angle detecting means 28 of
When the cylinder 21 is controlled so that the displacement angle Δθ1 becomes a predetermined value and the second displacement angle Δθ1 is obtained, the second
The force F2 detected by the detecting means 24 is obtained.

In step n5, the processing circuit 31 performs the calculation represented by the equation 1 to obtain the angle Δ which is the recovery strain of the tube 11.
θ2 is calculated and obtained.

[0018]

[Equation 1]

The angle Δθ2 calculated in this way
Moves the movable die 23 supporting the pipe 11 to the cylinder 21
Corresponds to the angle of recovery strain when the pipe 11 is opened by being sufficiently displaced in the direction away from the rotary mold 13. In the state where the displacement angle Δθ1 is achieved, the pipe 11 remains in contact with the curved portion 15 of the rotary mold 13, and no gap is generated.

Then, in step n6, the cylinder 2
1 is extended to move the movable die 23 to the approaching direction of the rotary die 13 (see FIG.
(3) to the right (to the right in FIG. 2) so that the pipe 11 abuts on the linear portion 16 and thus the force detected by the first detecting means 17 is zero or a positive value. Next, the rotating die 13 is further moved to the above-mentioned angle Δθ by the driving means 25.
Only 2 is additionally bent. This state is indicated by reference numeral G in FIG. Therefore, the cylinder 21 is contracted, the movable die 23 is moved away from the linear portion 16, and the pipe 1
Release 1. In this way, the pipe 11 can be plastically deformed at a desired 90 degrees and bent.

The present invention can be widely applied to bend not only pipes such as steel pipes but also other longitudinal members. In the above-described embodiment, since the pipe 11 does not separate from the curved portion 15 of the rotary die 13 and is always in contact with it, it is possible to bend the pipe 11 reliably and automatically, and improve the yield. Is possible.

As another embodiment of the present invention, instead of the displacement angle detecting means 28, a movable die 2 having a double-acting hydraulic cylinder 21 is used.
3 may be detected, and the angle Δθ in FIG. 3 may be calculated and obtained from this.

[0023]

As described above, according to the present invention, a long body such as a pipe is guided along a supporting type along a curved portion and a straight portion of a rotary type, and the long body is pressed by a movable type in advance. The elastic force F1 of the longitudinal body is obtained when the movable die is bent at a predetermined angle, and then the movable die is displaced from the linear portion in the separating direction to make the pressing force to the rotary die zero, and further acts on the longitudinal body. The force F2 exerted on the movable mold by the longitudinal body when the movable mold is moved in the separating direction by a predetermined displacement amount within the range where the force is released and does not become zero is measured, and the longitudinal body is bent from the predetermined angle by this. Since the additional angle Δθ2 to be processed is calculated and obtained, the longitudinal body is additionally bent. Therefore, during the bending work, the longitudinal body always comes into contact with the rotary bending portion. Cage, long body and curved There is no gap between the parts. Therefore, it becomes possible to bend the long body along the curved portion with high accuracy.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a simplified cross-sectional view seen from a section line ABCD in FIG. 1 (2).

FIG. 3 is a simplified plan view showing a configuration of a displacement angle detection means 28.

FIG. 4 is a block diagram showing an electrical configuration of the embodiment shown in FIGS.

5 is a flowchart for explaining the operation of the processing circuit 31 of FIG.

FIG. 6 is a graph showing the relationship between the rotation angle of the rotary die 13 and the force detected by the second detection means 24.

FIG. 7 is a simplified front view of the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Support type 11 Pipe 12 Bending device 13 Rotating type 15 Bending part 16 Straight part 17 First detecting means 20 Bracket 21 Double-acting hydraulic cylinder 22 Moving piece 23 Moving type 24 Second detecting means 25 Rotation driving means 26 Output shaft 27 Rotation Angle detecting means 28 Displacement angle detecting means 31 Processing circuit

Claims (2)

[Claims] 1. A rotary die having a curved portion is pressed against the longitudinal body to rotate the rotary die to bend the longitudinal body along the rotary die at a predetermined angle, and then to bend the longitudinal body into a rotary die. The first elastic force F1 of the longitudinal body when the pressing force of the longitudinal body is set to zero is measured, and the longitudinal body is predetermined in the direction in which the longitudinal body separates from the rotary die in the state where the longitudinal body is in contact with the curved portion. The second elastic force F2 is measured by displacing the displacement amount, and the longitudinal body is bent from the predetermined angle based on the first and second elastic forces F1 and F2 and the predetermined displacement amount. A bending method characterized in that the additional angle Δθ2 to be calculated is calculated, and bending is performed while pressing the longitudinal body by the additional angle Δθ2 against the rotary die. 2. A rotary die having a curved portion and a linear portion connected to the curved portion; a support die for supporting and guiding a longitudinal member by the rotary die; and a rotary die capable of moving toward and away from the linear portion. A movable die provided, a first drive means for rotationally driving the rotary die, a second drive means for driving the movable die in a direction of approaching and separating from the linear portion, and a first for detecting a force exerted by the longitudinal body on the linear portion. Detecting means, second detecting means for detecting the force exerted by the elongated body on the movable type, angle detecting means for detecting the rotation angle of the rotary type by the first driving means, first and second detecting means and angle detecting In response to each output from the means, the rotary die is rotated by a predetermined angle by the first drive means, and then the second die is moved in the direction away from the rotary die to be detected by the first detection means. Detection when the applied force becomes zero The force F1 detected by the step and the force F2 detected by the second detecting means when the movable die is further displaced in the separating direction by a predetermined displacement amount by the second driving means are obtained by calculation. A bending apparatus including: a control unit that rotationally drives the rotary die by the first drive unit while pressing the longitudinal body again on the linear portion of the rotary die by the additional drive angle Δθ2. .