JP2895188B2 - Tube bending equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a tube bending apparatus, and more particularly to a tube bending apparatus that performs a bending operation while applying a tensile force to a tube to be processed.

(Background Art) Bending of metal tubes occupies an important position in, for example, the vehicle industry. That is, the tube incorporated in the vehicle needs to be bent at a predetermined position in the longitudinal direction with high precision in order to extend or connect to other parts while avoiding other parts.

Conventionally, when performing this kind of bending process on the tube,
A predetermined bending process is performed by a gripping means for gripping the processing tube and moving and setting it to a predetermined position, and a die means for bending a predetermined position of the processing tube by a predetermined amount.After the bending process is completed, a three-dimensional measuring device is used. The bending dimension of the tube is measured, and when a correction request is generated, the moving set amount of the gripping means and the bending amount of the die means are adjusted in the next processing.

Further, in Japanese Patent Application Laid-Open No. 63-290624, a tube to be processed is set in advance by a gripping means for gripping the tube to be processed and moving it to a predetermined position and a die means for bending a predetermined position of the tube to be processed by a predetermined amount. There has been proposed a tube bending method and apparatus in which a predetermined position between a tip of a tube to be processed and a bending position is sensed by a position sensing means after bending is performed.

In the method according to this proposal, after bending the tube to be processed, the position is sensed by the position sensing unit, and the control unit controls the position so that the position has a preset value.
The bending amount of the die means is changed, and control is performed so that a preset bending process is realized.

(Problems to be Solved by the Invention) In the conventional method described above, after bending the first tube to be processed, the bending amount is adjusted by measuring the bending dimension with a three-dimensional measuring device. Tubes cannot be used as products in many cases, and can be used for relatively short tubes.However, for long tubes, the material, thickness, It is necessary to re-adjust each time due to the effects of differences in hardness, elastic limit, yield strength, etc. due to variations and the like.

Further, in the case of a small-diameter tube, bending may occur in the tube during measurement by a three-dimensional measuring device, so that accurate measurement of a bending dimension may not be performed.

On the other hand, the method proposed in JP-A-63-290624 is very difficult to apply to a long tube because the position sensing means becomes very large. Also,
In the case of a small-diameter tube, the bending of the tube after bending becomes larger toward the distal end, and it becomes impossible to detect the position with high accuracy.

The present invention has been made in view of the current state of tube bending as described above, and its purpose is to detect the amount of bending of a tube to be processed by a sensor during a processing step, and to detect the amount of detection by the sensor by a control device. However, an object of the present invention is to provide a tube bending apparatus in which a value is controlled so as to correspond to a program written in a memory in advance, and a preset bending process is performed accurately and efficiently.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a memory in which a bending program for a tube to be processed is stored, and a program which grasps a rear end of the tube to be processed and reads the program from the memory. A gripping device for moving the processed tube in the axial direction and around the axis, and a tube bending device for bending a predetermined position of the processed tube by a predetermined amount according to a program read from the memory; A bending die which is in contact with a peripheral surface and is rotatable about a rotary shaft, a pressing die device which is rotatable about the rotary shaft while clamping the tube to be processed by the bending die; A sensor provided in the device, for detecting the amount of bending of the tube to be processed, and the pressing die device set according to the program, A control device for rotating the bending die around the rotation axis, bending the work tube so that the amount of bending detected by the sensor approaches a predetermined value, and then releasing the set. It has become.

(Operation) According to the present invention, the bending die and the pressing die device hold the tube to be processed, and the bending die and the pressing die device rotate around the same rotation axis while holding the tube to be processed, thereby forming the workpiece. The tube is bent under tension. In this case, the control is performed by the control device so that the bent amount of the bent tube detected by the sensor attached to the pressing die device approaches the predetermined value stored in the memory.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing a configuration of an embodiment, in which a pressing die device 2 and a reaction force receiving portion 3 are disposed opposite to a bending die 1 having a mold surface 1P having a predetermined curvature. A straight guide surface 1S1 is formed on the bending die 1 so as to be continuous with the mold surface 1P. The cross-sectional shape of the mold surface 1P and the linear guide surface 1S1 is the same as a part of the cross-section of the processed tube 4 arranged in contact with the linear guide surface 1S1, and in the embodiment, the cylindrical processed tube 4 is formed. Are used, the cross-sectional shapes of the mold surface 1P and the linear guide surface 1S1 are semicircular.

The bending die 1 is configured to be rotatable about a rotation shaft 1c.

Further, the pressing die device 2 has a pressing die 2b which is movable in a direction perpendicular to the linear guide surface 1S1 along both sides of the base 2a.
Is provided. A photoelectric type tube detection sensor 5 is attached to one side edge of the base 2a.
The whole can rotate around the rotation shaft 1c.

The reaction force receiving portion 3 comprises a base 3a, a reaction force receiving bracket 3b movable on the base 3a at right angles to the linear guide surface 1S1, and a reaction force receiving roller 3c provided at the tip of the base. The force receiving roller 3c is configured to engage with or disengage from the tube 4 to be introduced and disposed in contact with the linear guide surface 1S1.

In the vicinity of the rear end of the processed tube 4 which is introduced and disposed in contact with the linear guide surface 1S1, a gripping device 6 for gripping the processed tube 4 and moving the processed tube 4 in the axial direction and rotating about the axis is provided. It is arranged.

On the other hand, a control device 7 is provided.
a, a memory 7b, a ROM 7c, and an input / output circuit 7d, and the input / output circuit 7d, the memory 7b, and the ROM 7c are connected to the CPU 7a via a bus B. The signal lines 8a to 8d are provided between the tube detecting sensor 5, the pressing die device 2, the gripping device 6, the reaction force receiving portion 3, the bending die 1, and the input / output circuit 7d.
Connected to each other at 8e.

The memory 7b of the control device 7 includes a bending program for the tube 4 to be processed, that is, a variation in the material, outer diameter, wall thickness, and heat treatment conditions of the tube 4 to be processed, and a plurality of programs in the axial direction of the tube 4 to be processed by the gripping device 6. Data such as the movement positions and their order, the rotation angle of the gripping device 6 about the axis at each movement position, the bending angle of the tube 4 to be processed by the bending die 1 and the pressing die device 2 at each movement position, and the like are written in advance. Have been.

Command signals for driving the gripping device 6, the pressing die 2b, the reaction force receiving portion 3, and the bending die 1 are signal lines 8c, 8c, respectively.
The signals are input to the gripping device 6, the pressing die 2b, the reaction force receiving portion 3, and the bending die 1 from the input / output circuit 7d via b, 8d, 8e. The detection signal from the tube detection sensor 5 is input to the input / output circuit 7d via the signal line 8a.

 Next, the operation of the embodiment will be described.

When a start button (not shown) is turned on in the embodiment, CP
U7a reads the bending program from memory 7b,
A drive command signal is input to the gripping device 6 via the input / output circuit 7d and the signal line 8c, and the gripping device 6 grips the rear end portion of the processed tube 4 having the specified outer diameter and extends in the axial direction to the first commanded position. At that position, the work tube 4 is rotated about the axis by the commanded angle, and stopped while holding the work tube.

In this way, when the work tube 4 is moved to the first processing position and stopped, the bending process is performed on the work tube 4 at that position.

2 (a) to 2 (g) are explanatory views showing each step of bending in the embodiment, and FIGS. 3 (a) and 3 (b) are flowcharts showing bending in the embodiment.

As described above, when the processing tube 4 is transferred to the processing position and is stopped and held, the control device 7 is moved to step S1.
A command signal is input to the reaction force receiving portion 3 through the signal line 8d, and the reaction force receiving member 3b of the reaction force receiving portion 3 moves forward as shown in FIG. Are engaged with the processed tube 4 to be in a holding state. In step S2,
The operation angle of the pressing die 2b is read from the memory 7b and set, and the process proceeds to step S3, where the pressing die 2b rotates around the rotation shaft 1c by the set operation angle.

Then, proceeding to step S4, it is determined whether or not the tube detection sensor 5 has detected the processed tube 4. If this determination is NO, step S5 proceeds to step S2.
The correction value C (2) is added to the operation angle set in step (1), and the pressing die 2 is further rotated at the new operation angle as shown in FIG. 2 (b).

If the determination in step S4 is YES, the process proceeds to step S6, where the initial pipe detection angle of the processed tube 4 is detected, and in step S7, as shown in FIG.
Returns to the initial position.

Next, at step S8, the theoretical bending angle B (n) of the process
Is read from the memory 7b, and the theoretical bending angle B (n)
Is added with the correction value H (n), and the bending angle is set.
The initial position of the correction value must not exceed a return angle caused by a spring bag of the tube 4 to be processed, which will be described later. Then, proceeding to step S9, FIG. 2 (d)
As shown in (1), the pressing die 2b of the pressing die device 2 moves forward to clamp the work tube 4. And step
In S10, the bending die 1 and the pressing die device 2 rotate about the shaft 1c, and the pressing die 2b and the bending die 1 perform bending of the tube 4 as shown in FIG. 2 (e). .

In step S11 after bending, the pressing die 2b of the pressing die device 2 is retracted and lowered as shown in FIG. 2 (f). At this time, the bent tube is changed from a two-dot chain line to a solid line by springback. A slight return occurs as shown.

FIG. 4 is an explanatory view showing the retraction and lowering of the pressing die 2b in step S11. After the bending, the pressing die 2b is moved from the solid line position in FIG. Retreat diagonally and descend. And step
Proceeding to S12, the pressing die device 2 is further rotated about the axis 1c by the set operation angle as shown in FIG. 2 (g).
Next, proceeding to step S13, similarly to step S4 described above, a determination is made as to whether or not the tube detection sensor 5 detects the processed tube 4. If this determination is NO, the operation proceeds to step S14. The correction value C (3) is added to the angle, and in step S15, the bending die 1 and the pressing die device 2 are rotated at the new operation angle until the tube detection sensor 5 detects the workpiece tube 4.

If the determination in step S13 is YES, the angle of the tube after bending is measured in step S16, the bending angle is calculated by subtracting from the initial tube detection angle in step S6, and read from the memory 7b by the CPU 7a. The error is compared with the reference bending angle in steps S17 and S18.

Then, in step S19, it is determined whether or not this error is smaller than the allowable reference error. If the determination is NO, in step S20, the bending die 1 and the pressing die device 2 detect the bending angle, that is, the tube bending angle. After returning to the position after the springback, the operation from step S8 is repeated. If the determination in step S19 is YES, in step S21, the correction data is written to the memory 7b of the control device 7, and is used as a correction value for the next bending of the tube to be processed. Then, in step S22, the bending die 1 and the pressing die device 2 return to the initial position. In step S23, the reaction force receiving member 3b of the reaction force receiving portion 3 retreats, and the engagement between the tube 4 and the reaction force receiving roller 3c is stopped. In this manner, the bending of the tube 4 to be processed at the first predetermined position is completed, and the gripping device 6 is operated according to the program stored in the memory 7b to move the tube 4 to the next predetermined position. After being transferred, the next bending is performed in accordance with the program stored in the memory 7b at that position.

Hereinafter, similarly, the entire bending of the tube 4 to be processed is advanced by the gripping device 6 and the pressing die device 2 operated under the control of the control device 7 in accordance with the program stored in the memory 7b. That is, for the second and subsequent tubes, the entire bending is advanced by the drive command from the memory 7b without detecting the angle by the tube detecting sensor 5.

Further, the wear of the bending die 1, the pressing die device 2, the pressing die 2b and the reaction receiving roller 3c, the set positions of the bending die 1, the pressing die device 2 and the reaction receiving metal fitting 3b at the time of setup, and the material of the tube 4 to be processed. The effect on the bending accuracy, such as the hardness, elasticity limit, and difference in yield force, due to variations in the outer diameter, wall thickness, heat treatment conditions, etc., is detected by the tube detection sensor 5 during processing. By controlling so as to match the reference value, the offset is completely canceled, and a high-precision bending process is performed.

In the embodiment, the case where a photoelectric sensor is used as the tube detection sensor has been described.However, the present invention is not limited to the embodiment, and a sensor incorporating a switch such as a proximity switch or a limit switch, The tube detection sensor may be configured by a light blocking type sensor, a vibration detection sensor, or the like.

(Effects of the Invention) As described in detail above, in the present invention, a sensor for detecting the tube to be processed is provided, and the control device performs control based on the detection value of this sensor. Not only the effects of differences in diameter, wall thickness, heat treatment conditions, etc., but also the differences in hardness, elastic limit, yield force, etc., but also the effects of mechanical accuracy, as well as the bending angle with respect to the abrasion of the bending member and the set position Correction is made by performing control that sometimes approaches the reference value, and high-precision bending can be performed continuously and efficiently.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a configuration of an embodiment of the present invention, FIGS. 2 (a) to 2 (g) are explanatory views showing each step of bending in the embodiment, and FIGS. 3 (a) and (b). 4) is a flowchart showing the bending process of the embodiment, and FIG. 4 is an explanatory diagram of release of the setting of the pressing die device in the embodiment. 1 ... bending die, 1P ... mold surface, 1S1 ... linear guide surface,
2 ... Press die device, 2a ... Base, 2b ... Press die, 3
... Reaction force receiving part, 4 ... Tube to be processed, 5 ... Tube detection sensor, 6 ... Gripping device, 7 ... Control device, 7a
... CPU, 7b ... memory, 7c ... ROM, 7d ... input / output circuits, 8a to 8e ... signal lines.

Claims (1)

(57) [Claims] 1. A memory in which a bending program of a tube to be processed is stored, and a rear end of the tube to be processed is gripped, and the tube to be processed is moved in the axial direction and around the axis in accordance with a program read from the memory. In a tube bending device for bending a predetermined position of the tube to be processed by a predetermined amount according to a gripping device and a program read from the memory, the tube is in contact with the peripheral surface of the tube to be processed and is rotatable around a rotation axis. The bending die is set to a position where the tube to be processed is clamped between the bending die and the bending die. From this position, the tube is rotatable around the rotating shaft while clamping the tube to be processed on the peripheral surface of the bending die. According to the program, a pressing die device, a sensor provided in the pressing die device, and detecting a bending amount of the tube to be processed. The pressing die device is set, the pressing die device is rotated around the rotation axis, and the work tube is bent so that the bending amount detected by the sensor approaches a predetermined value. And a control device for canceling the bending.