JP2720476B2 - Roll processing control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention monitors a processing state of a workpiece during roll processing or a state of a roll processing apparatus in real time, and controls the roll processing apparatus using the state data. The present invention relates to a roll processing control device.

[Prior art] In roll processing, for example, a work is sandwiched between an upper pressure roller and a lower backup roller, and a load is applied to the pressure roller by a hydraulic cylinder or the like, thereby causing the work to be plastically deformed. This is a processing method for performing desired molding.

The quality of the work after the roll working is determined by the degree of forming accuracy or residual stress, work hardening rate, fatigue limit and the like.

Of these, the accuracy of molding can be visually inspected online. As for the peening process, there is a technique for measuring the reflected light of the surface to be processed by a measuring device immediately after the peening process to judge the quality of the processing result (Japanese Patent Laid-Open No. 61-1318).
No. 69).

However, inspection of internal residual stress and the like is impossible by visual observation or reflected light from the surface, and must be performed by some special measurement. As a measuring method, there is a measurement by X-ray diffraction or a measurement in a depth direction by etching of a measurement site.

[Problems to be Solved by the Invention] However, measurement by X-ray diffraction requires a long measurement time and analysis thereof, and measurement by etching requires a long etching processing time, and the apparatus is large and unsuitable online.

For this reason, it was not possible to judge whether the processing conditions were appropriate at the time of processing, and there was a possibility that a large number of defective products would be produced.

In addition, the conventional roll processing apparatus cannot immediately determine the state of a roll when an abnormality such as pitching occurs, and cannot immediately perform processing for the abnormality, which also leads to the generation of defective products. , And a failure of the roll processing device.

Further, the roll pressure control at the time of roll processing is performed by a hydraulic cylinder, and the pressurization control for the work is performed assuming that the hydraulic pressure corresponds to the roll pressure. Since the pressure from the hydraulic cylinder is transmitted from the hydraulic cylinder, the hydraulic pressure on the hydraulic cylinder side cannot be said to completely correspond to the pressure value applied to the work, which is one of the causes of a decrease in roll processing accuracy.

Therefore, an object of the present invention is to realize an apparatus that measures a workpiece processing state or a state of a roll processing apparatus immediately online and accurately performs a roll pressing control or a retreat processing based on data obtained by the measurement. .

[Means for Solving the Problems] That is, the gist of the present invention is, as exemplified in the basic configuration diagram of FIG. 1, an acoustic emission detecting means M2 provided in a roll working device M1, and the acoustic emission State detecting means M3 for detecting a processing state from the waveform of the acoustic emission signal detected by the detecting means M2, and adjusting means M4 for adjusting the roll load based on the processing state detected by the state detecting means M3. A roll processing control device, comprising:

[Action] Acoustic emission (hereinafter also referred to as “AE”) is an ultrasonic vibration generated when a material is deformed. Since the work is plastically deformed by roll processing,
If the above AE is captured by the acoustic emission detecting means M2 and the state of the waveform is detected by the state detecting means M3, the degree of the plastic deformation should be known. And when you catch the AE, it's when the roll is actually being processed.
Therefore, the state detection means M3 detects the processing state in real time.

On the other hand, the roll itself may cause breakage such as pitching during roll processing. In this case, the unique
AE occurs. Therefore, the machining state in which such an abnormality has occurred can also be determined in real time from the waveform detected by the state detection means M3.

If the adjusting means M4 adjusts the excess or deficiency of the roll load based on this processing state, it is possible to perform suitable roll processing with good adjustment response, achieve high quality, and prevent the occurrence of defective products. . Further, if an abnormality of the roll processing device itself is found, a failure of the roll processing device and occurrence of defective products due to the failure can be prevented by a method such as reducing the roll load to zero.

Example Next, an example of the present invention will be described. The present invention is not limited to these, and includes various embodiments in a range not departing from the gist thereof.

FIG. 2 is a system configuration diagram of a roll processing device equipped with a roll processing control device according to one embodiment of the present invention.

The roll processing apparatus 1 itself is a generally used apparatus as shown in FIG. This roll processing device is 1
Has a lower tool 3 and an upper tool 5, and the upper tool 5 is provided with a support portion 7 erected on the lower tool 3.
Above, it is supported with the pivot point Pb as the swing center.

A roll processing section 9 is provided on one side of the support section 7. Backup rollers 11a and 11b support the work W and apply a rotational force to the lower side of the lower tool 3 of the roll processing section 9.

A pressure roller is provided on the upper tool 5 side of the roll processing section 9.
A work 13 is provided between the work W and the backup rollers 11a and 11b.

On the other side of the support part 7, a hydraulic cylinder 15 is provided,
The cylinder body 15a side is connected to the lower tool 3 side, and the rod 15b side is connected to the upper tool 5 side. The hydraulic pressure of the hydraulic cylinder 15 can be controlled by a hydraulic pressure setting unit 17.

The hydraulic pressure setting unit 17 mainly includes various hydraulic circuit elements and an electric drive circuit for an electromagnetic valve, and adjusts the hydraulic pressure of the hydraulic cylinder 15 according to an input signal. By this hydraulic control, the stroke of the hydraulic cylinder 15 and the load of the pressure roller 13 can be adjusted.

The details of the pressure roller 13 are shown in FIG.
The upper tool 5 is slidably contacted with the two rollers 13a, 13b, and the processing portions W1, W2 of the work W are slid through the rollers 13a, 13b. Is applied with a pressure P to plastically deform into a desired shape.

An AE sensor 21 composed of an acoustic transducer that detects an AE wave and converts the AE wave into an electric signal is provided on the upper tool 5 near the sliding contact with the rollers 13a and 13b. The output signal of the AE sensor 21 is amplified by the preamplifier 23 and the main amplifier 25 while preventing noise and a decrease in the SN ratio. The state of the amplified signal A is as shown in FIG.

Further, the signal A is split into two paths, and the filters A 27 and
(b) Signals having frequency characteristics in a predetermined band are demodulated by the detection circuits 29a and 29b and input to the signal processing unit 31.

The system of the filter 27a and the detection circuit 29a is a system for measuring the plastic deformation of the work W. In the filter 27a, the frequency characteristic of the AE caused by the plastic deformation of the work W (400K in this embodiment).
Hz-600 KHz) (FIG. 5 (B)).
This signal B is detected by a detection circuit 29a and converted into a zero base point signal C (FIG. 5 (C)).

On the other hand, the system of the filter 27b and the detection circuit 29b is a roller
This is a pitching measurement system of 13a and 13b, and the filter 27b extracts only a signal D having an AE frequency characteristic (100 KHz to 200 KHz in this embodiment) generated by the pitching (FIG. 5 (D)). This signal D is detected by a detection circuit 29b and converted into a zero base point signal E (FIG. 5 (E)).

As shown in FIG. 4, the signal processing unit 31 includes a roll load determining unit including a level setting circuit 31a and a window comparator 31b, a pitching determining unit including a high-pass filter 31c, a measuring unit 31d, and a reference value generating unit 31e; It is composed of a hydraulic pressure adjustment stop unit including a gate circuit 31f, an amplitude measurement circuit 31g, and a reference value signal generation unit 31h.

The window comparator 31b determines whether the roll load is excessive or insufficient based on the reference outputs L1 and L2 output from the level setting circuit 31a, and outputs a high level from a line corresponding to the excessive or insufficient roll load.

The high-pass filter 31c extracts only the pitching AE signal F from the signal E (FIG. 5 (F)). The measuring unit 31d measures the amplitude of the signal F, and outputs a high-level signal when pitching has occurred based on the reference value L3 output from the reference value generating unit 31e. When there is no pitching, the level is low.

When receiving the oil pressure decrease signal or the oil pressure increase signal from the oil pressure setting unit 17, the gate circuit 31f opens the gate and transmits the signal C to the amplitude measurement circuit 31g. The reference value signal generator 31h outputs the reference values Ls1 and Ls2 for stopping or decreasing the hydraulic pressure to the amplitude measuring circuit 31g. The reference outputs L1 and L2 output from the level setting circuit 31a have the following relationship.

L1>Ls1>Ls2> L2 The above-mentioned signal processing unit 31 performs a foot-back process for adjusting the roll load based on the processing state detected by the AE sensor 21. This processing will be described with reference to the timing chart of FIG.

First, when the signal C shown in the figure is input to the plastic deformation measurement system, the window comparator 31b outputs the signal C and the reference outputs L1 and L2.
Compare with As a result of the comparison, the plastic deformation is appropriate and the signal C is
If it is between L1 and L2, all signals to the hydraulic pressure setting unit 17 are low level signals (before t1).

When the plastic deformation is large and the signal C exceeds L1, the window comparator 31b sets the excessive signal to a high level (t
1). Then, the hydraulic pressure setting unit 17 controls the hydraulic pressure to decrease, and the hydraulic pressure of the hydraulic cylinder 15 decreases. Accordingly, the amount of plastic deformation of the work W also decreases, and the detection level of the AE represented by the signal C decreases.

The gate circuit 31f detects that this oil pressure reduction control is being performed from a signal from the oil pressure setting unit 17 (for example, an on / off signal of an electromagnetic valve), opens the gate, and transmits the signal C to the amplitude measurement circuit 31g. I do.

The amplitude measurement circuit 31g keeps the signal at the low level until the signal C drops to the level Ls1 of the signal C.
2), a high-level pulse signal is output as a stop signal. Accordingly, the oil pressure is kept constant and the degree of plastic deformation is constant, so that the level of the signal C is constant. The reason why the hydraulic pressure can be controlled from the level of the signal C is that the relationship between the level of the AE wave generated by the plastic deformation and the roll load uniquely corresponds well as shown in FIG. 7 (A). is there. This relationship has a good relationship with not only the roll load but also physical parameters at the time of roll processing such as residual stress, work hardening rate, and fatigue limit. The relationship is shown in FIGS. 7 (B)-(D).

On the other hand, if the plastic deformation is insufficient and the signal C falls below L2, the window comparator 31b sets the insufficient signal to a high level (t3). Then, the hydraulic pressure setting unit 17 controls the hydraulic pressure to increase, and the hydraulic pressure of the hydraulic cylinder 15 increases. Accordingly, the amount of plastic deformation of the work W also increases, and the detection level of the signal C increases.

The gate circuit 31f determines that the oil pressure increase control is being performed based on a signal from the oil pressure setting unit 17, opens the gate, and transmits the signal C to the amplitude measurement circuit 31g.

The amplitude measuring circuit 31g keeps the signal at the low level until the level of the signal C rises to Ls2. However, when the signal exceeds Ls2 (t4), it outputs a high-level pulse signal as a stop signal.

Accordingly, the oil pressure is kept constant and the degree of plastic deformation is constant, so that the level of the signal C is constant.

The gate circuit 31f is closed at the time when the increase / decrease control of the hydraulic pressure is completed (t2, t4).

In this way, when the plastic deformation deviates from the range of the reference values L1 and L2, the feedback control is performed so as to be substantially near the center thereof. Since this control is performed based on the AE wave immediately generated at the time of plastic deformation, high-response quick control is achieved, and a suitable roll load, that is, a suitable amount of plastic deformation can be obtained immediately. Therefore, reduction of defective products can be realized.

As shown by the dotted line, when a high-level signal with pitching is input (t5), in any case, only the process of decreasing the hydraulic pressure is performed prior to other processes, and the load on the roller 13 is reduced to zero. That is, the evacuation processing is performed. This is because when pitching occurs on the surface of the roller 13, the work W
This is because the quality cannot be guaranteed. In this way, an increase in defective products can be prevented, and the roll processing device 1 can be protected.

In the above-described embodiment, the stop signal output timing is performed based on the two levels Ls1 and Ls2. Of course, if both the rising side and the decreasing side cross this reference based on an appropriate one level, The oil pressure may be kept constant. Further, when a predetermined distance from one level is approached, the oil pressure may be kept constant.

Also, as shown in FIG. 4, by providing the display devices 33 and 35, a signal may be input as indicated by a chain line to display the current state of the roll processing. In the display device 33, based on the excessive signal and the insufficient signal from the window comparator 31b, when one or both of the excessive signal and the insufficient signal is at a high level, the corresponding lamp is turned on. Turn on the appropriate lamp. Furthermore, if the pitching signal from the measuring unit 31d is at a high level, the display device 35
The NG lamp is turned on, and if the level is low, the appropriate lamp is turned on.

In this way, the operator of the roll processing device can easily confirm the current situation.

In the above embodiment, the roll load is determined based on the level of the AE (signal C). However, the roll load may be determined by obtaining the integral value of the AE wave for more precise detection. The integration of this AE wave is the eighth
By inserting the circuit shown in the figure immediately before the window comparator 31b, the following operation is performed.

That is, as shown in the timing chart of FIG. 9, the timing generation circuit 37 compares the signal C with the output voltage V0 of the reference value generation section 39, and outputs a high-level timing signal when V0 or more. The integration circuit 41 starts integration of the signal C at the rise of the timing signal, stops integration at the fall, and outputs an analog signal corresponding to the level to the window comparator 31b. The window comparator 31b determines this level and outputs a signal indicating whether the level is excessive or insufficient.

As shown in FIG. 10, the window comparator 31b
Separately or in place of the path, a data correction circuit 43 is provided to convert the integrated signal into a roll load, and output an analog signal or a digital signal corresponding to the roll load for load feedback control and display. May be used.

Although each of the above-described devices is configured by a discrete circuit, it is needless to say that the same feedback control or display control as described above can be performed as a configuration controlled by a microcomputer. FIG. 11 shows a configuration using a microcomputer. The control device 51 mainly includes a microcomputer unit 51a and a hydraulic pressure switching unit 51b. This function corresponds to the signal processing unit 31 and the oil pressure setting unit 17 described above.

The microcomputer unit 51a includes a CPU, a ROM, a RAM, and the like. However, since the hardware configuration is generally well known, a detailed description thereof is omitted.

As shown in the flowchart of FIG. 12, the microcomputer 51a controls the external signal from the input unit 51c, here, the pitching signal and the A / D-converted signal C.
Is read (step 110), and the integrated value is compared with the reference value L (step 120). If the integrated value is higher, the hydraulic pressure switching unit 51b is driven via the output unit 51d to lower the hydraulic pressure (step 130). On the other hand, if the pressure is low, a process of increasing the oil pressure (step 140) is performed. If the pitching signal is at a high level, control is performed to make the oil pressure zero (steps 150 and 160).

In addition, an average value may be obtained from the signal C, and physical parameters at the time of roll processing such as residual stress, work hardening rate, and fatigue limit may be estimated, and quality control may be determined based on deviations and variations. Is also good.

When determining the level of the signal C, if there is only a very weak output even though the roll processing has been started, it is determined that the roller 13 has fallen off or there is another abnormality, and the hydraulic pressure is reduced to zero. May be controlled.

In the above embodiment, the AE sensor 21 corresponds to the acoustic emission detecting unit M2, the signal processing unit 31 or the microcomputer unit 51a corresponds to the state detecting unit M3, and the hydraulic pressure setting unit 17 or the hydraulic switching unit 51b corresponds to the adjusting unit M4. Applicable. Of the processing executed by the microcomputer unit 51a, the processing of steps 110, 120, and 150 corresponds to the processing as the state detecting means M3, and the processing of steps 130, 140, and 160 corresponds to the processing as the adjusting means M4.

[Effects of the Invention] Since the present invention controls the roll load from the result obtained by measuring the waveform of the acoustic emission signal immediately output during plastic deformation control or pitching,
Since real-time and processing status can be understood and prompt action can be taken, the reduction of defective products can be achieved.

Further, since the abnormality of the roll processing device itself is immediately identified, it contributes to reduction of defective products and protection of the roll processing device.

AE is generated from a work according to a processing state such as plastic deformation of the work. Therefore, since the state of the workpiece is grasped very accurately, the machining itself can be precisely controlled,
It can also contribute to quality improvement.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a basic configuration of the present invention, FIG. 2 is a system configuration diagram of an embodiment, FIG. 3 is a schematic diagram of a roll processing apparatus,
FIG. 4 is a block diagram of a signal processing unit, and FIGS.
(F) is a waveform diagram of the AE signal, FIG. 6 is a timing chart of control of the signal processing unit, FIGS. 7 (A) to (D) are graphs showing a relationship between AE and physical parameters at the time of roll processing, 8 is a block diagram for integration, FIG. 9 is a timing chart of the processing, FIG. 10 is a block diagram in which a data configuration circuit is provided in the circuit of FIG. 8, and FIG. 11 is a case where a microcomputer is used. FIG. 12 is a flowchart of the process. M1,1 Roll processing device M2 Acoustic emission detection means M3 State detection means M4 Adjustment means 21 AE sensor 31, Signal processing unit 51a Microcomputer unit 17 Hydraulic setting Section, 51b ... hydraulic switching section

Claims (1)

(57) [Claims] An acoustic emission detecting means provided in a roll processing device, a state detecting means for detecting a processing state from a waveform of an acoustic emission signal detected by the acoustic emission detecting means, and a state detected by the state detecting means An adjustment means for adjusting a roll load based on a processing state.