JP2724545B2 - Pipe 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 pipe bending machine mainly for detecting the elasticity of a processed product during pipe bending and performing automatic correction and additional processing of data.

[0002]

2. Description of the Related Art Conventionally, data of a bending amount input to a pipe bending machine of this type is input with a large amount in consideration of elasticity in advance, or an approximate amount of elasticity derived from past data is used. It was added to the input data and processed. Therefore, the first processed product was inspected for the target shape, and the error was corrected by the operator.

[0003] On the other hand, after bending a pipe, a clamp is temporarily released to detect the amount of springback, and is then clamped again to perform an additional bending process (for example, Japanese Patent Laid-Open No. S59-5959). -92120).

[0004]

However, the elasticity of the former pipe bending machine is not only constant depending on the material of the pipe, the production lot and the like, but also the setting position of each mold to be attached to the bending portion. Errors also cause errors in the machining shape, and to correct errors due to these causes,
Remove and detect the processed product, the operator corrects the data,
Since it was necessary to repeat the process of processing and inspecting with a new pipe again, in order to obtain complete processing data, some defective pipes were generated, and time was also lost.

[0005] The above work requires some skill and requires a specialized worker.

Further, in the latter pipe bending machine, since the clamp mold is once released to detect the amount of springback after the pipe bending, not only the shape of the pipe after bending is unstable, but also the surface of the pipe is not stable. The wounds increase,
Or there are drawbacks such as workability is significantly reduced,
It was not suitable for precision processing or mass production.

[0007] In view of the above-mentioned problems, the present invention does not require any skill of an operator at the time of bending a pipe, is extremely excellent in operability, and generates defective products at the time of initial adjustment. Can be prevented, and the adjustment time for the initial adjustment can be significantly reduced.Also, the occurrence of defective products can be minimized even during continuous processing, and the pipe can be quickly processed even in subsequent processing. It can be processed with high precision, and furthermore, stabilizes the shape of the pipe after bending,
In addition, the present invention provides an optimal pipe bending machine for precision machining and mass production.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a bending arm for bending a pipe, a clamp type for holding a pipe attached thereto, A roll type opposite to this,
Release the operation of the bending arm to a standard pipe bending machine having a pressure type for holding a straight section of pipe, a driving device for driving the bending arm, and an encoder for detecting the amount of movement of the bending arm. And a free device for feeding back the elasticity of the processed product to the bending arm after bending the pipe.

Further, as a free device of the bending arm,
It employs a method in which a driving device is actively used and a method in which a hydraulic bypass circuit is provided.

[0010]

In the pipe bending machine according to the present invention, the bending arm is driven by the driving device while holding the pipe with the clamp type and holding the straight portion of the pipe with the pressure type at the time of bending the pipe. By rotating the pipe while bending it with this bending arm and feeding back the elasticity of the processed product to the bending arm with a free device, the encoder detects the amount of movement of the bending arm and the stable shape of the pipe. , Elasticity, elastic modulus, etc.
Further, based on this data, the amount of movement of the bending arm for obtaining the originally intended shape is obtained, and the processing data is automatically corrected.

In addition, even after the above-mentioned processing data is obtained, the pipe remains set in the pipe bending machine, so that the pipe can be additionally processed as it is to obtain the desired shape, and the shape of the processed product can be obtained. Also to automatically stabilize.

Further, during continuous machining, the shape of the workpiece is checked by the free device and the encoder, and in subsequent machining, the same machining as the conventional one is performed based on the corrected data. I do.

[0013]

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

As shown in FIG. 1, a pipe bending machine according to the present invention comprises a bending arm 1 for bending a pipe A.
A clamp die 2 for holding a pipe A attached thereto, a roll die 3 located opposite to the clamp die, a pressure die 4 for pressing a straight line portion of the pipe A, and a power transmission device. The operation of the bending arm 1 is released to a standard pipe bending machine having a driving device 5 that is driven via the bending arm 8 and an encoder 6 that detects the amount of movement of the bending arm 1. A free device 7 for feeding back the elasticity of the workpiece to the bending arm 1 later is added.

After bending the pipe A, the free device 7 feeds back the amount of elasticity of the processed product to the bending arm 1 so that the stable shape of the processed product is detected by the encoder 6 and the data is automatically converted. In addition to the correction, the processed product is additionally processed to the desired shape, and in the subsequent processing, the processing is performed based on the corrected data.

That is, as shown in FIG. 2, the pipe A is held down by the clamp mold 2 and the straight portion of the pipe A is held down by the pressure mold 4, and the driving force generated by the drive unit 5 is reduced. The power is transmitted to the bending arm 1 via a power transmission device 8 so that the pipe A rotates while bending the pipe A. The rotation angle at this time is a target angle at which the pipe A is to be machined, and thereafter, the feedback control is performed by the encoder 6 provided in the rotation shaft system or the drive system.

Next, after the bending arm 1 is moved to a target angle at which the pipe A is to be machined, the driving force of the bending arm 1 is eliminated by the free device 7, and the bending arm 1 can be freely moved.

When the driving force of the bending arm 1 is lost and the bending arm 1 can freely move, the bending arm 1 is moved to a position where the pipe A itself is in a stable state by the elastic force of the pipe A.

By measuring the amount of movement at this time by the encoder 6, the shape of the pipe A in a stable state can be known.

The difference between the angle at which the bending arm 1 first moves and the stable angle of the pipe A determines the elasticity and elastic ratio of the pipe A at the target angle.

When the target angle to be bent is set to RO degree based on the value obtained as described above, since this angle becomes a stable state of the pipe A, the angle at which the bending arm 1 must move must be set. Is the RS degree and the elasticity ratio is r, there is a geometrical series relationship of RS = RO + RO × r + RO × r × r.

The RS angle obtained from the above equation is automatically corrected as the amount of movement of the bending arm 1 and the operation of the free device 7 is released. Additional processing is performed to the desired shape.

It is a matter of course that only the data can be corrected without correcting the moving amount of the bending arm 1 corrected here or performing the above-described operation.

The following processing of the pipe A is performed by the same operation as the conventional one based on the corrected data.
Processing can be performed at a processing speed similar to that of a conventional pipe bending machine.

With the pipe bending machine of the present invention, the angle of the stable state of the pipe A can be checked at any time.
During the continuous processing, the quality can be stabilized by checking the angle of the stable state of the pipe A itself as described above at every predetermined processing number or at predetermined time.

In addition, by setting an allowable error of the processing angle in advance and comparing it at the time of the above-mentioned confirmation, it is possible to know the occurrence of an unacceptable product.

Further, the free device 7 has the following 2
It shall be configured using any one of the types.

On the other hand, the free device 7 actively uses the driving force to freely move the bending arm 1 by an external force. The free device 7 moves the driving force in a certain direction from a state where there is no driving. When the bending arm 1 is gradually increased, the bending arm 1 starts to move at the moment when the friction or the transmission loss of the mechanical system is exceeded, the driving force at this time is stored, the driving force is set to F +, and the driving force is set to F +. The direction is changed in the opposite direction, and the operation is performed in the same manner. The driving force at this time is F-. Then, by alternately driving with a value slightly smaller than F + and F−, that is, a driving force slightly before the bending arm 1 starts moving and at a frequency equal to or less than the maximum frequency that can be responded by the driving system, a slight external The bending arm 1 can be moved with a great force. By this operation, the movement becomes apparently the same as the movement of the drive system of the bending arm 1 being released. According to the one free device 7, it can be used in two systems: a hydraulic drive system using a hydraulic pump, a hydraulic cylinder, and a hydraulic servo valve, and a motor drive system using a servo motor, a servo amplifier, and a reduction gear. .

The other free device 7 controls the hydraulic servo valve so that hydraulic oil does not flow, and forms a hydraulic circuit that bypasses between a pair of ports of the servo valve. Hydraulic oil in the cylinders can freely enter and leave each other's cylinder chambers, so that the bending arm 1 can move freely. According to the other free device 7, it can also be used for a hydraulic drive system using a hydraulic pump, a hydraulic cylinder, and a hydraulic servo valve.

The drive device 5 for the bending arm 1 employs a hydraulic drive system using a hydraulic pump, a hydraulic cylinder, and a hydraulic servo valve, and a motor drive system using a servo motor, a servo amplifier, and a reduction gear. Thus, the above two types of apparatuses, which are the most common types of pipe bending machines, can be provided to the market.

[0031]

As described above, the present invention provides a bending arm 1 for bending a pipe A as described above, a clamp die 2 for holding the pipe A attached thereto, and a roll positioned opposite to this. A standard pipe bending machine having a mold 3, a pressure mold 4 for holding a straight portion of a pipe A, a driving device 5 for driving the bending arm 1, and an encoder 6 for detecting an operation amount of the bending arm 1. In addition, a free device 7 for releasing the operation of the bending arm 1 and feeding back the elasticity of the processed product to the bending arm 1 after bending the pipe A is added. While holding the pipe A and holding the straight portion of the pipe A by the pressure mold 4, the bending device 1 is driven by the driving device 5, and the pipe A is bent by the bending arm 1. Rotate motion, and is fed back to the arm 1 the bending elasticity of the workpiece by free device 7, the arm 1 bending at the encoder 6
Since the operation amount of the pipe A can be detected, the stable shape of the pipe A can be obtained without removing the pipe A from the pipe bending machine of the present invention.
The amount of elasticity, elastic modulus, etc. can be known.

Further, since the movement amount of the bending arm 1 can be detected by the encoder 6, the movement amount of the bending arm 1 for obtaining the originally intended shape can be obtained based on this data. Can be automatically performed, and the operability is extremely excellent without requiring any skill of the operator.

Further, even after the above-mentioned processing data is obtained,
Since the pipe A remains set in the pipe bending machine, the desired shape can be obtained by performing additional processing as it is, so that defective products can be prevented from occurring during initial adjustment, and Since the shape of the processed product is automatically stabilized, the adjustment time at the time of the initial adjustment can be greatly reduced.

In addition, since the shape of the processed product can be checked by the free device 7 and the encoder 6 during the continuous processing, the occurrence of defective products can be minimized. Since processing similar to the conventional processing can be performed based on the corrected data, the pipe A can be processed quickly and with high accuracy.

Further, the amount of operation of the bending arm 1 can be detected by the encoder 6 by feeding back the elasticity of the processed product to the bending arm 1 by the free device 7, so that the pipe A can be moved from the pipe bending machine of the present invention. Since the pipe A is not taken out, the bent shape of the pipe A can be stabilized and the surface of the pipe A can be stabilized without once releasing the clamp mold for detecting the springback amount after the bending of the pipe as in the related art. It is most suitable for precision machining and mass production because it can reduce scratches on the surface and significantly improve workability.

Further, as the free device 7 of the bending arm 1, there are two systems, a hydraulic drive system using a hydraulic pump, a hydraulic cylinder, and a hydraulic servo valve, and a motor drive system using a servo motor, a servo amplifier, and a reduction gear. The present invention can also be applied to a hydraulic drive system using a hydraulic pump, a hydraulic cylinder, and a hydraulic servo valve.

Therefore, according to the pipe bending machine of the present invention, operability is extremely excellent at the time of bending a pipe without requiring any skill of an operator, and defective products are generated at the time of initial adjustment. Can be prevented, and the adjustment time for the initial adjustment can be significantly reduced.Also, the occurrence of defective products can be minimized even during continuous processing, and the pipe can be quickly processed even in subsequent processing. In addition, the pipe can be processed with high precision, the shape of the pipe after bending can be stabilized, and various effects such as being optimal for precision processing and mass production can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of the present invention.

FIG. 2 is a schematic view showing a state where the pipe of FIG. 1 is bent.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bending arm 2 Clamp type 3 Roll type 4 Pressure type 5 Drive device 6 Encoder 7 Free device 8 Power transmission device A Pipe

Claims (3)

(57) [Claims] 1. A bending arm for bending a pipe, a clamp type for holding a pipe attached thereto, a roll type located opposite to the bending type, and a pressure type for pressing a straight part of the pipe. A standard pipe bending machine having a driving device for driving the bending arm, and an encoder for detecting an operation amount of the bending arm ,
Pipe bending machine, characterized in that the addition of free device for feeding back to said bending arm elasticity of the workpiece to release the operation of the bending arm after bending of the pipe. 2. The pipe bending machine according to claim 1, wherein a drive device is actively used as a free device for the bending arm. 3. The pipe bending machine according to claim 1, wherein a hydraulic bypass circuit is provided as a free device for the bending arm.