JP2765480B2 - Tube bending machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bending apparatus used for U-bending of a tube bar, and more particularly to a bending apparatus for a tube bar using a bending mold called a bend roll.

[0002]

2. Description of the Related Art In a mold bending using a bending die called a bend roll, as shown in FIG. 6, a material is bent at an angle of 180 degrees along an outer peripheral surface of a horizontally arranged bend roll R. . On the outer peripheral surface of the bend roll R, the material W
Dice grooves corresponding to the outer surface shape are provided. Further, a bending member C composed of a clamp is used to push the material W into the die groove, and a groove similar to the die groove is provided on the inner surface thereof.

In bending, a material W is sandwiched between a bend roll R and a bending member C. In this state, the bend roll R and the bending member C are synchronously driven around a bending center, that is, around the center of the bend roll R. The material W
Is pressed into the die groove of the bend roll R by the bending member C and is bent. At this time, the material W is pulled by the bending member C and moves in the axial direction. Therefore, this bending is called pull bending.

In some cases, a roller having a groove similar to a die groove on the outer peripheral surface is used as the bending member C.
In this case, only the bending member C rotates around the center of the bend roll R, and the material W does not move in the axial direction. This bending is called roll bending.

That is, die bending using a bend roll is roughly classified into pull bending and roll bending.

When a U-bend tube is manufactured by such a bending, the central portion is bent 180 ° in a horizontal plane along the outer peripheral surface of the bend roll R by a bending member C. In general, the material W is fixed in a state where one of the materials W is sandwiched across the central processing portion, and the other rotates in a horizontal plane with the bending of the central portion. When the material W is long, handling of the horizontal turning portion W 'becomes a problem. In order to solve this problem, a holding device for mechanically holding the horizontal turning portion W' of the material W is disclosed in 5
No. 4-4862.

[0007] The conventional holding device includes a center of a bend roll,
That is, the arm extends horizontally from the vertical axis provided on the extension line of the bending center, and is capable of pivoting around the vertical axis. A plurality of hanging tools for holding are provided, and the arm is turned in accordance with the operation of the horizontal turning part W 'during processing, thereby mechanically holding the horizontal turning part W'.

[0008]

However, in the conventional holding device, since the arm is operated by the manual handle, labor is required, and an operation corresponding to the operation of the horizontal turning portion W 'of the material W is required. It also requires technology.

[0009] If the arm is driven to rotate in synchronization with the bending, the problems in work and technology can be solved for the time being. For example, in the bending where the bend roll operates together with the bending member, this is realized by connecting the center of rotation of the bend roll and the center of rotation of the arm with a single axis.

However, when the arm is connected to the bender body, not only is it difficult to transfer the material after bending, but also the bender body is driven violently when the bender body starts and stops operating, and the vibration is transmitted to the arm. . Since the arm is a long object having a length equal to or more than の of the entire length of the material W, it is inherently vulnerable to vibration. Become. In addition, the arm has an extremely large operation radius as compared with the main body of the bender, so that there is a problem that the arm cannot be synchronized with rapid acceleration and deceleration when the operation of the main body starts and stops.

Therefore, it is conceivable to separate the arm from the bender body and independently drive the arm based on the detected operating speed of the bender body. However, even if this is done, the problem of synchronization due to the difference in allowable speed change between when the operation of the vendor itself starts and when it stops operation will not be solved.

For this reason, the automation of the holding device has not been realized at present.

An object of the present invention is to automatically and accurately follow and hold a horizontal turning portion of a material from the start of operation to the end of operation of a bender body, and furthermore, it does not prevent material from running out after bending, so that the holding device can be used. An object of the present invention is to provide a bending device for a tube rod material which can be manufactured at a low cost.

[0014]

According to a first aspect of the present invention, there is provided an apparatus for bending a tube rod, comprising: a bend roll provided with a die groove on an outer peripheral surface corresponding to an outer shape of a material to be bent; A bender body having a bending member that can hold a bending material and can be rotated around a bending center, a driving unit that drives at least the bending member at a constant speed, and a sensor that detects an operation angle of the bending member; An arm extending in a horizontal direction from a vertical axis provided on an extension line of the bending center and capable of turning around the vertical axis, and a suspender suspended from the arm and holding a horizontal turning portion of the material to be bent. A holding device having a variable-speed drive unit for rotating the arm, a speed-up mode based on a preset speed-up gradient, and a constant-speed mode based on a measured operation speed of the bender body. , In advance Switching control is performed in the order of the deceleration mode based on the deceleration start point determined and the deceleration gradient calculated from the measured operation speed of the bender body, and the bender body is set so that the arm stops within the same angle range at the same timing as the bender body. And a turning controller for delaying the start of the operation of the arm from the turning start of the arm.

[0015]

The arm performs a speed-up turning and a deceleration turning at a unique small gradient, so that the arm can perform a smooth operation with little vibration or the like despite having a large operation radius. Further, since the start of turning of the arm is earlier than the start of operation of the bender body, the stop timing of both can be the same even though the speed-up gradient and the deceleration gradient of the arm are reduced.

[0016]

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

FIG. 1 is a side view showing an entire configuration of an example of a die bending apparatus embodying the present invention, FIG. 2 is a block diagram showing a configuration of a turning controller, and FIGS. 3 and 4 are operations of the turning controller. 5 is a graph for explaining.

The mold bending apparatus is used for manufacturing a U-bend tube. As shown in FIG.
0 and the material W to be bent by the bender body 10
(Here a tube) a holding device 2 for holding a horizontal turning part W '
0 and a turning controller 30 for controlling the holding device 20.

The bender body 10 is the pulling and bending device described with reference to FIG. The horizontally arranged bending roll R is driven to rotate together with the bending member by a driving unit M including a hydraulic motor. The operation angle is detected by the rotation angle sensor S.

The holding device 20 has a column 21 erected on the side of the bender body 10, and a vertical shaft rotatably supported by two support arms 29, 29 extending laterally from the column 21. 22 and a horizontal arm 23 extending laterally from the lower end of the vertical shaft 22. The vertical shaft 22 is located above the bender body 10 and is concentric with the operation center thereof, and is rotationally driven via a gear 25 by a drive unit 24 composed of a variable speed AC servomotor. The arm 23 is held in a horizontal state by a plurality of wires 26 with a turn buckle extending over an upper portion of the vertical shaft 22 from a plurality of positions in the longitudinal direction, and horizontally rotates around a base end portion by the rotation of the vertical shaft 22. . The arm 23 has a waterside turning portion W ′ of the material W.
Are mounted at intervals in the longitudinal direction.

The turning controller 30 causes the holding device 20 to perform the operation shown in FIG. 3C with the configuration shown in FIG. FIG. 3A shows the operation of the vendor main body 10, and FIG.
(B) shows the turning operation of the arm 23 when the turning start of the arm 23 is coincident with the start of the operation of the bender body 10.
FIG. 3 (C) shows that the turning of the arm 23 is stopped by the bender body 10.
Shows the turning operation of the arm 23 when the operation is stopped.

As shown in FIG. 3 (A), the operation of the bender body 10 rapidly increases at the start of the operation, continues to operate at the set speed, and then rapidly decelerates to stop the operation. . In the case of manufacturing a U-bend tube, the operation angle is set to, for example, 200 ° in consideration of return by springback.
The gradients at the time of acceleration and deceleration are not intentionally set, but always exist. With this gradient, the holding device 20
As described above, when the arm 23 is turned, a large acceleration and a deceleration are applied to the arm 23 having a large operation radius, and vibration and possibly damage occur.

Therefore, the arm 23 first performs a speed-up turning at a predetermined gradient (AB, A'-B '). The speed increasing gradient is set to the maximum within a range in which the arm 23 does not vibrate. Next, a constant speed turn is performed at the same angular velocity as that of the bender body 10 (B-C, B'-C '). Finally, deceleration turning is performed at a predetermined gradient (C-D, C'-D '). Like the deceleration gradient, the deceleration gradient is set to the maximum within a range in which the arm 23 does not vibrate or the like. The turning angle of the arm 23 is usually 180 to 200 ° when the operation angle of the bender body 10 is 200 ° in the manufacture of the U-bend tube.
It is said.

Here, the speed-up gradient and the deceleration gradient of the arm 23 are smaller in each stage than the speed-up gradient and the deceleration gradient of the bender body 10. That is, the arm 23 takes more time to increase and decrease the speed than the bender body 10. Therefore, when the start of turning of the arm 23 is coincident with the start of operation of the bender body 10, as shown in FIG. 3B, the turning of the arm 23 continues even after the operation of the bender body 10 ends. In other words, even when the bender body 10 reaches the operation stop angle, the arm 23 has not reached the turning stop angle.
This causes an inconvenience that the material W is deformed due to a large difference between the relative positions thereof.

Therefore, as shown in FIG. 3C, the start of turning of the arm 23 is made earlier than the start of operation of the bender main body 10 so that the turning stop of the arm 23 coincides with the stopping of the operation of the bender main body 10. It is the turning controller 30 shown in FIG. 2 that causes the arm 23 to execute the turning operation shown in FIG.

In the turning controller 30 shown in FIG. 2, when an operation start command is issued, the command is transmitted to a speed switching signal X (stop → stop).
(Speed-up switching) is given to the speed switch 31. As a result, the speed switch 31 enters the speed increasing mode. During the speed-up mode, the speed-up calculator 33 calculates the speed-up angular velocity based on the speed-up gradient preset in the speed-up gradient setter 32. The calculated increased angular velocity is given to the speed switch 31 as a speed instruction signal x. The indicated angular velocity is provided to the drive unit 24 of the holding device 20 via the speed switch 31.

Thus, the arm 23 turns at a predetermined acceleration gradient (AB in FIG. 3C). As described above, the speed increasing gradient is the maximum gradient within a range where vibration of the arm 23 does not occur.

The operation start command is also input to the delay circuit 34. The delay circuit 34 gives the operation start command to the drive unit M of the bender body 10 with a delay of Δt from the input of the operation start command. Although the setting of the delay time Δt will be described later, even if the bender body 10 starts to operate with a delay due to the small acceleration gradient of the arm 23, the bender body 1
0 reaches the set speed earlier than the arm 23.

When the bender body 10 starts operating, its operation angle is detected by the rotation angle sensor S. The detected operation angle is converted into an operation angular velocity by calculating a time change of the operation angle by the velocity calculator 35. The operating angular velocity is given to the velocity comparator 36. Speed comparator 3
6 compares the angular velocity (set speed of the bender body 10) input from the speed calculator 35 with the angular velocity (increased angular velocity of the arm 23) input from the accelerated speed calculator 33,
When the former coincides with the latter, a speed switching signal Y (increased speed → constant speed switching) is supplied to the speed switch 31. As a result, the speed switch 31 enters the constant speed mode. During the period of the constant speed mode, the angular speed (set speed of the bender main body 10) calculated by the speed calculator 35 is used as the speed command signal y as the speed switch 3
Given to one.

Thus, the arm 23 is attached to the bender body 10
A constant speed turn is performed at the same angular velocity as in FIG. 3 (C).
C).

The operation angle detected by the rotation angle sensor S of the bender body 10 is also supplied to an angle comparator 37, where it is compared with a deceleration start angle supplied from an angle setting unit 38. In the angle setting unit 38, the stop angle and the deceleration start angle of the arm 23 are set in advance as the angle of the bender body 10.

The stop angle of the arm 23 is, as described above,
When the stop angle of the bender body 10 is set to 200 ° in the manufacture of the U-bend tube, the angle is set to about 180 to 200 °. The deceleration start angle of the arm 23 is a deceleration gradient that is set to the maximum within a range where the arm 23 does not vibrate, and the angle required for the arm 23 to stop when the arm 23 decelerates from the set speed of the bender body 10. Is subtracted from the stop angle of the arm 23. The angle of the bender body 10 corresponding to the angles of these arms 23 is set in the angle setting device 38 in advance.

The operation angle of the bender body 10 is
, The angle comparator 37 gives the speed switch 31 a speed switching signal Z (constant speed → deceleration switching). As a result, the speed switch 31 enters the deceleration mode.
During the deceleration mode, the deceleration speed calculator 39 calculates the deceleration angular speed. That is, the deceleration start speed and the stop angle are input to the deceleration speed calculator 39 from the angle setting device 38, the operating angular speed of the bender body 10 is input from the speed calculator 35, and the deceleration angle coincidence signal is input from the angle comparator 37. Is entered. Then, based on the operating angular velocity, the deceleration start angle, and the stop angle from the velocity calculator 35 at the time when the deceleration angular velocity coincidence signal is input, after the deceleration angle coincidence,
The deceleration angular velocity is calculated every moment, and this is the speed switch 3
1 is given as a speed command signal z.

Thus, the arm 23 turns at a predetermined deceleration gradient (CD in FIG. 3C). The deceleration gradient here is the maximum gradient within a range in which the arm 23 does not vibrate or the like as described above.

When the operation start command is input to the drive section M of the bender body 10 through the delay circuit 34, the bender body 10 starts operation with a delay of Δt from the arm 23. The arm 23 stops operating at the same time. This delay time Δt is obtained as follows.

The turning controller 30 shown in FIG. 2 performs the turning control without detecting the angle of the arm 23. For this reason, the arm angle at the time of speed-up → constant speed switching, the arm angle at the time of constant speed → deceleration switching, and the arm angle at the time of stop are unknown. However, the approximate turning angle θ of the arm 23 from the turning start to the constant speed switching.
1 and the required time t1 can be calculated from the acceleration / deceleration gradient and the set speed of the bender body 10, and the approximate turning angle θ2 of the arm 23 from deceleration switching to stop and the required time t2 are the deceleration start angle. It can be calculated from the deceleration gradient used at the time of setting and the set speed of the bender body 10. In addition, the arm angle at the time of stopping is predetermined.

Therefore, if the stop angle of the arm 23 is set to, for example, 180 ° as described above, the approximate angle at which the arm 23 turns at a constant speed is 180 ° − (θ1 + θ2). Dividing by speed,
The approximate constant-speed turning time t3 can be calculated, and the sum of these times (t1 + t2 + t3) is the time required from the start to the stop of driving of the arm 23.

On the other hand, the time T required from the start to the stop of the operation of the bender body 10 can be calculated from the set speed of the bender body 10 and the stop angle.

Therefore, if the bender body 10 and the arm 2
3 starts operation simultaneously (in the case of FIG. 3B)
The arm 23 stops with a delay of [(t1 + t2 + t3) -T]. Therefore, the operation start of the bender body 10 is delayed by [(t1 + t2 + t3) -T] from the start of the rotation of the arm 23. This is the delay time Δt.

As described above, according to the turning controller 30 shown in FIG. 2, the arm 23 performs the speed-up turning and the decelerating turning at a small gradient, so that the arm 23 has a small operating radius despite having a large operating radius. A smooth operation can be performed. In addition, by starting the rotation of the arm 23 earlier than the operation of the bender body 10, even if the speed-up gradient and the deceleration gradient of the arm 23 are reduced, both can be stopped within the same angle range at the same time. it can. Further, the swing control of the arm 23 can be performed without detecting the swing angle.

An advantage of stopping the bender body 10 and the arm 23 within the same angle range at the same time is that the material W is not deformed. Advantages of eliminating the need for the turning angle sensor of the arm 23 include simplification of the device configuration and elimination of the initial setting operation.

In the turning controller shown in FIG. 2, the angular velocity from the velocity calculator 35 (the set velocity of the bender body 10) and
The angular velocity (increased angular velocity of the arm 23) from the accelerated velocity calculation 33 is compared by the velocity comparator 36, and when the two coincide, switching from the accelerated mode to the constant velocity mode is performed. That is, constant speed switching is performed at the same speed. But,
When the rotation of the bender body 10 is performed by a fluid source such as a hydraulic pressure and the speed at the time of startup is very unstable and violent vibration occurs as shown in FIG. 5, it is difficult to detect the above-mentioned speed coincidence. In such a case, a turning controller 30 as shown in FIG. 4 may be used.

The turning controller 30 shown in FIG.
Is omitted, and instead, a constant speed start angle is added as an angle set in the angle setting unit 38, and constant speed switching is performed at the same angle as in deceleration switching. The constant speed start angle can be obtained in the same way as the above-described deceleration start angle. Based on the acceleration gradient and the set speed of the bender main body 10, the turning angle of the arm 23 until the two speeds match is calculated.
The angle of the bender body 10 corresponding to this is set. The angle comparator 37 compares the operation angle of the bender body 10 with the constant speed start angle, and if they match, sends a speed switching signal Y (increased speed → constant speed switching) to the speed switch 31.

In the above-described embodiment, the vendor main body 1
Since the turning angle and the turning speed of the arm 23 are obtained from the operation angle of 0, the stop angle of the arm 23 may be shifted depending on the magnitude of the error. In order to prevent this, an angle detection sensor for the arm 23 and / or a stop angle sensor may be added. Then, the stop angle of the arm 23 can be controlled independently of the bender body 10, and the arm angle at the time of stop has higher accuracy and reproducibility.

In the above embodiment, the bending is performed.
It is also applicable to roll bending.

[0046]

As is clear from the above description, the tube bending apparatus of the present invention does not require labor and skill because the arm of the holding device is mechanically pivoted. Since the arm is separated from the bender body and driven independently,
The production cost of the arm can be reduced by not inhibiting the transfer of the material after the bending and suppressing the transmission of vibration to the arm. Even though the arm is separated from the bender body, the difference in allowable speed during acceleration and deceleration can be cleared and both can be synchronized with high accuracy.
The material can be held without bending the material at the bending member.

[Brief description of the drawings]

FIG. 1 is a side view showing an overall configuration of an example of a mold bending apparatus embodying the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a turning controller.

FIG. 3 is a graph for explaining the operation of the turning controller.

FIG. 4 is a block diagram showing another configuration of the turning controller.

FIG. 5 is a graph for explaining the operation of the turning controller.

FIG. 6 is a plan view showing a basic configuration of a mold bending device.

[Explanation of symbols]

 W Material W 'Horizontal turning portion of material W R Bend roll C Bending member M Drive unit 10 Bender body 20 Holding device 22 Vertical axis 23 Arm 27 Hanging tool 30 Rotation controller

Claims (1)

(57) [Claims] 1. A material to be bent is sandwiched between a bend roll having an outer peripheral surface provided with a die groove corresponding to the outer shape of the material to be bent, and the bend roll is rotatable about a bending center. A bending member, a bender body having a driving unit that drives the bending member at a constant speed, and a bender body extending horizontally from a vertical axis provided on a bending center extension line of the bender body, and capable of turning around the vertical axis. Arm, a hanging device suspended from the arm to hold a horizontal turning portion of the material to be bent, a holding device having a variable speed drive unit for turning and driving the arm, and a turning speed of the arm, A speed increase mode based on a preset acceleration gradient, a constant speed mode based on the actual operation speed of the bender body, a deceleration mode based on a preset deceleration start point and a deceleration gradient calculated from the actual operation speed of the bender body. And a turning controller for delaying the operation start of the bender body from the turning start of the arm so that the arm stops within the same angle range at the same timing as the bender body. Tube bending machine.