JPH08300085A - Wire straightening equipment - Google Patents

Abstract

PURPOSE: To efficiently straighten the bending at high precision by subtracting the amount corresponding to the elastic deformation from the measured value by a total deformation detecting means, comparing the result with the initial ending amount, stopping the application of the straightening load when the difference is zero, thereby applying the necessary straightening load in one action. CONSTITUTION: A control means 43 is provided with a subtractor 46 to subtract the amount corresponding to the elastic deformation from the total deformation of a work W obtained by a function generator and a pulse counter 44 as an elastic deformation operating means 45 to operate the amount corresponding to the elastic deformation of the work W which can be obtained by extrapolating the load-deformation characteristic in the elastic deformation range of the work W by the present straightening load. In addition, a comparator 47, etc., to compare the result of subtraction with the initial bending amount obtained by an initial bending measuring means 10 is provided. When the difference in comparison becomes zero, the load completion command is outputted to a driver 32f of a servo motor 32d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal wire rod constituting a generally used elongated member such as a linear guide device and a ball screw device used in general industrial equipment, machine tools, semiconductor manufacturing equipment and the like. The present invention relates to a bending correction device for a wire rod, which can efficiently correct the bending of the wire in a short time.

[0002]

2. Description of the Related Art Generally, the straightening of a wire is carried out by supporting the wire at two points and measuring the amount of bending between supporting spans, and then applying a bending straightening load to the midpoint of the bending to accurately measure the amount of bending. This is done by generating the total amount of elastic and plastic deformation in the direction opposite to the bending. The plastic deformation of a linear metal material has an elastic deformation region and a plastic deformation region, and its change is usually represented by a stress-strain diagram.

However, since the amount of deformation of the wire material that occurs during the application of the straightening load appears as a total amount of deformation in which the elastic deformation amount and the plastic deformation amount are superposed, it is truly necessary for bending correction. It is not the amount of deformation. Therefore, in the conventional bending correction of a wire rod based on the total deformation amount, in order to avoid that the correction load reaches the breaking point D of the wire rod, a small correction load is applied to the wire rod and a small amount of deformation is applied to measure the bend. It is usual to repeat the above steps and gradually correct the bend while finally converging to the required accuracy. FIG. 7 shows an example of the load-displacement characteristic diagram in the bending correction work of the wire rod by repeating such conventional pressurization and measurement. The straightening load exceeding the yield point of the material is repeatedly applied four times, and the plasticity is improved. The amount of deformation is gradually increased, and the required amount of plastic deformation is finally obtained by the fourth load.

[0004]

However, in such correction by trial and error, the yield point of the wire material is increased each time the pressure is applied by repeating the pressure exceeding the yield point, and the plastic deformation region is narrowed. Approach the break point. Therefore, there is a problem that cracks may occur in the wire material or, in the worst case, breakage may occur.

Further, since proper plastic deformation cannot be obtained by pressing once, pressing and measurement must be repeated, and there is a problem that correction work takes time. As a wire bending correction device, there is also a device that corrects the bending amount step by step while passing the wire between a plurality of pressure rollers arranged in series. Applicable only to simple shapes.
For example, when the cross-sectional shape is discontinuous due to bolt holes at various points along the length of the wire, such as the guide rails of a linear guide device, the elastic and plastic characteristics (stress-strain characteristics) of the material may vary depending on the location. Since it changes, the correction accuracy is limited and the applicable range is limited.

Therefore, the present invention has been made by paying attention to such a problem of the conventional method for straightening the bending of the wire, and the load-displacement is obtained by simultaneously measuring the bending straightening load of the wire and the displacement of the wire. Obtain the characteristics, load-correction load that is truly necessary by grasping the plastic deformation amount of the wire at the time of corrective load with reference to the value of the elastic deformation region in the load-displacement characteristic, and pressurizing with a single pressurization. Accordingly, it is an object of the present invention to provide a wire rod straightening device that enables efficient and high-precision bending straightening.

[0007]

SUMMARY OF THE INVENTION A wire rod bending straightening apparatus of the present invention which achieves the above-mentioned object, is an initial bend measuring means for sequentially measuring the bending amount and position of a metal wire rod along the longitudinal direction of the metal wire rod. A bending correction means for applying a bending correction load to the metal wire for each predetermined supporting span based on the measurement data of the initial bending measurement means, and a current correction load for detecting the magnitude of the current correction load by the bending correction means Detecting means, total deformation amount detecting means for detecting the total deformation amount of the elastic deformation amount and the plastic deformation amount in the correction direction of the metal wire rod by the current correction load, and the elastic deformation amount equivalent amount of the metal wire rod with respect to the current correction load. The elastic deformation amount calculating means for calculating and the elastic deformation amount equivalent amount are subtracted from the measured values of the total deformation amount detecting means, and the result is compared with the initial bending amount, and when the difference becomes zero, the Is characterized in that the rising and a control means for stopping the load of straightening load by correcting means.

[0008]

The bending feature of the wire is expressed by a total bend, a partial bend, a bend approximate to a single arc, and a meandering complex bend. In the wire rod straightening apparatus of the present invention, first, the bending feature of the metal wire rod which is the work is accurately grasped by measuring the bending form of the work by the initial bend measuring means of the bend measuring system. At that time, even if the bending feature of the whole work is a meandering complicated bend,
It is partially approximated to a single arc bend, and can be regarded as its continuous form. Therefore, the entire bend of the work W is divided into a plurality of single arcs, and the bends are successively measured for each single arc. Next, in the bending correction system,
Finally, the entire bend is corrected by correcting the bend for each single arc based on the bend data for each single arc.

Now, the bending amount Y as shown in FIG.
Both ends of a single arc-shaped metal wire (work) W having _C (hereinafter, referred to as initial bending amount) are supported by supporting points p ₁ and p _2.
Two points are supported by, the bending straightening means F applies a bending straightening load F to the middle point of the supporting span L to pressurize it to the maximum deformation Y _B , and then the load is removed until the bending reaches zero. When the deformation amount of the work is plotted on the Y axis and the load F is plotted on the X axis, a load-deformation characteristic diagram schematically shown in FIG.

In the figure, A is the yield point, B is the maximum load deformation point,
C represents a point at which the bend becomes zero, and D represents a break point. The work is quadratic curve AB from the elastic deformation area from load 0 to yield point A.
Through the plastic deformation region indicated by, the maximum load deformation point B is reached and the maximum deformation Y _B is reached. Here Excluding load F, becomes zero bend back to the point C through a line extending from the maximum load X _B to the load 0 BC (parallel to 0A). The straight line Y = aX is an elastic characteristic interpolation straight line obtained by extending the load-displacement relationship of the elastic deformation region 0A, and as is clear from the figure, this straight line Y = aX
The difference in the Y coordinate between aX and the quadratic curve AB is the initial bending amount Y.
_The point equal to _C is the maximum load deformation point B.

Here, the deformation amount Y of the work with respect to the value of the current correction load X between the plastic deformation regions AB is the total amount (hereinafter, referred to as total deformation amount) in which the elastic deformation amount and the plastic deformation amount are superposed. In the conventional straight wire bending correction,
At the maximum load deformation point B, only the total deformation amount Y _B is captured.
However, the true amount of deformation required to correct the bending of the work is only the amount of plastic deformation, and the amount of elastic deformation must be canceled.

In the present invention, the straight line Y = aX in the elastic deformation region is interpolated in the plastic deformation region to cancel the elastic deformation amount. That is, in the wire bending correction apparatus of the present invention, first, the initial bending measuring means accurately finds the initial bending amount Y _C of a single arc of the work. Next, a bending straightening load is applied to the work by the bending straightening means. At this time, the current corrective load detecting means detects the magnitude of the corrective load currently being applied moment by moment, and the total deformation amount detecting means is the sum of the elastic deformation amount and the plastic deformation amount of the workpiece currently being deformed. Figure 1 (a)
Recognize the load-deformation characteristic line of the work such as. However, this load-deformation characteristic acquired during correction may be acquired separately in advance.

When the straightening load exceeds the yield point A and reaches the plastic deformation area, the elastic deformation component calculating means calculates the Y coordinate value of the point E corresponding to the current straightening load on the elastic characteristic interpolation line Y = aX. Is calculated as the elastic deformation equivalent amount aX. The control means subtracts the elastic deformation equivalent amount from the total deformation amount detection value of the work due to the current straightening load, compares the subtraction result with the initial bending amount Yc, and when the difference becomes zero, the maximum load displacement. When it is judged that the point B has been reached, the bending correction load is stopped by the bending correction means.

Thus, the maximum load X _{B can be obtained} by one straightening load.
It is possible to efficiently correct the bending of the entire work by sequentially repeating the load correction up to the point where a plastic deformation amount substantially equal to the initial bending amount is applied and the bending correction is performed for each single arc of the work.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 2 to 4 show one embodiment of the present invention. FIG. 2 is an overall plan view of one embodiment of the wire straightening apparatus of the present invention, FIG. 3 is the same side view, and FIG. 4 is the same apparatus. 3 is a schematic configuration diagram of the control system of FIG. The bending correction device for a wire according to this embodiment is configured by linking a bending measurement system 1 and a bending correction system 2. The bend measuring system 1 is provided with an initial bend measuring means 10 for sequentially measuring the bend of a metal wire W as a work along the longitudinal direction of the wire. On the other hand, the bending correction system 2 is provided with a bending correction means 30 that supports the work W based on the measurement data of the initial bending measurement means 10 and applies a bending correction load thereto.

The initial bend measuring means 10 comprises a work supporting / transferring part 12 and a self-propelled bend measuring part 13 which are provided on an elongated table 11. The work support / transfer unit 12 includes a plurality of drive rollers 14 that support the work W at the time of bending measurement and convey the work W in the longitudinal direction after the measurement.
And two lifters 15 arranged at intervals in the longitudinal direction so that the work W can be temporarily held in a natural body by supporting the vessel before being lowered onto the rollers 14,
And a reversing device 16 for reversing the work W around its axis. By changing the phase of the work W by the reversing device 16, even if the load direction of the correction load on the work W is one direction, it is possible to correct the change in the bending direction from a plurality of directions. The reversing operation is always performed before the process of setting measurement and correction.

A pressure roller 17 is composed of a pressing roller 17a and a lifting cylinder 17b.
The work W is placed on the driving roller 14 by the pressing roller 17a.
It is a mechanism for pressing the work piece W to suppress the floating of the work W having a bend, and reliably transporting the work W to the bend correction system 2. The bend measuring unit 13 includes a self-propelled table 21 equipped with a displacement sensor 20 such as a spindle type linear position sensor.
A linear guide device 22 which is a linear guide mechanism of the self-propelled table 21, a rack and pinion device 23 which is a linear drive mechanism, and a driving servomotor 24 are provided on the table 11 which provides straightness accuracy in advance. It is arranged as a measurement table unit.

The bending correction means 30 is disposed adjacent to the downstream side of the initial bending measurement means 10 and at a predetermined position determined based on the initial bending measurement data, the work W is provided.
Is provided with a supporting portion 31 for supporting the two points, and a pressing portion 32 for applying a bending correction load to one point between the supporting spans. The support portion 31 is composed of a pair of symmetrically arranged work support rollers 31a, a support roller separation / contact mechanism 31b for separating and contacting the work W with respect to the work W, and a support roller spacing adjustment mechanism 31c. Pressure unit 32
Is a pressure roller 32a arranged on the axis of symmetry of the pair of work supporting rollers 31a, and the pressure roller 32a.
A pair of ball screw devices 32b that are the feeding mechanism of
Gear mechanism 32c for transmitting driving force to the ball screw shaft
And a servomotor 32d as a drive source thereof.

The bending measurement system 1 to the bending correction system 2
When the work W is conveyed to the position, it is necessary to accurately send out a targeted portion to be corrected to the support portion 31 by a predetermined distance and to position it, and as shown in FIG. 4, an encoder-equipped position detection roller 26 is provided for that purpose. The pulse output is fed back to the control device via the pulse counter 27.

Next, the control system of the mechanism of the bending correction means 30 having the above-mentioned structure will be described based on the conceptual view of the apparatus system of FIG. The pressure roller 32a of the bending correction means 30 is provided with a load sensor such as a load cell as a current correction load detection means for detecting the magnitude x of the correction load (current correction load) F being applied to the work W at present. 40 are installed. The output of the load sensor 40 is transmitted from the load sensor amplifier 41 to the control means 4 via the A / D converter 42.
It is fed back to 3. The output of the bending measurement displacement sensor 20 of the initial bending measurement means 10 is sent to the control means 43 via the displacement sensor amplifier 20a, and
The pulse output of the encoder 24e (built in the servo motor 24), which is a position sensor for measuring the x coordinate of the displacement sensor 20, is sent through the pulse counter 24b. Further, the pulse output of the encoder 32e (built into the servo motor 32d), which is a position sensor for measuring the y-coordinate of the pressure roller 32a of the bending correction means 30, is fed back via the pulse counter 44 as correction deformation amount information of the work W. To be done. The encoder 32e and the pulse counter 44
In order to detect the total deformation amount of the elastic deformation amount Y of the work W in the correction direction by the current correction load F (proportional to the magnitude X of the load F and represented by Y = aX) and the plastic deformation amount. A total deformation amount detecting means is configured.

The current straightening load F is applied to the control means 43.
For example, a function generator as the elastic deformation amount calculation means 45 for calculating the elastic deformation amount equivalent amount of the work W obtained by extending (linear interpolation) the load-deformation characteristics in the elastic deformation region of the work W to the plastic deformation region by A subtracter 46 for subtracting the elastic deformation equivalent amount from the total deformation amount of the work W obtained by the pulse counter 44, and a comparison for comparing the subtraction result with the initial bending amount obtained by the initial bending measuring means 10. A device 47 and the like are provided and are configured to output a load completion command to the driver 32f of the servomotor 32d when the comparison difference becomes zero.

When the work straightening device for bending the work W having the two-dimensional bending as shown in FIG. The work W is placed on the roller 14. Next, the lifters 15 and 15 with adjusted intervals support the vessel support points of the work W and lift the work W. Here, the vessel support point is a fulcrum position where the amount of shortening of the total length due to the deflection of the wire rod by its own weight is minimized, and the position is 0.22 L inward from both ends of the wire rod of length L, respectively. By supporting this point at two points, it is possible to balance the deflection of its own weight and hold the wire in the most stable natural body, and the bending due to elastic deformation of the free deflection is minimized to improve the measurement accuracy.

One end of the work W held in the natural body is grasped by the reversing device 16 and swung 90 degrees around the axis, and the lifter 15 is lowered in a state where the bending direction is horizontal and the work W is
On the roller 14. Next, the probe of the displacement sensor 20 of the initial bending measuring means 10 which is moved to the origin position is used as the work W
2, the pinion of the rack and pinion device 23 is driven by the servo motor 24, and the initial bending amount is measured over the entire length of the work W while self-propelled from the left end to the right end in FIG. In this measurement, the pulse output of the encoder 24e is sent to the control means 43 via the pulse counter 24b, and the longitudinal direction (x direction) of the work W is fixed every fixed number of pulses.
Coordinates at regular intervals (for example, every 5 mm) are stored in a storage unit (not shown). At the same time, the stroke length of the displacement measuring displacement sensor 20 is output as the displacement in the y direction for each pulse of the constant interval, and is sent to the control means 43 via the displacement sensor amplifier 20a and stored in the storage unit.

The entire bending pattern is recognized from the amount of deformation of the work W in the y direction thus obtained and the position of the measurement point in the x direction. The entire bending pattern is a continuous form of partial single arc bends A1 and A2, and the initial bending amount Yc of the work for each span L ₁ and L _{2 of} each single arc A1 and A2 and its measurement position coordinates. Bend correction based on.

The work is conveyed to the bending correction system by rotating the drive type roller 14 of the roller support / transfer section 12 by a drive source (not shown). At this time, there is a possibility that the work W may be lifted from the drive roller 14 and may not move due to bending due to its own weight. Therefore, the work W is conveyed while being pressed against the drive type roller 14 by the pressure roller 17 as shown in FIG. At this time, the position detection roller 26 with an encoder is pressed against the work W and rolled along the bend. The rolling of the roller 26 is fed back to the control means 43 as a pulse output of the rotary encoder via the pulse counter 27, and the feed position in the longitudinal direction of the work is accurately grasped. The feed amount in this case is a linear distance, whereas the roller 26 traces the feed length of the work in a curved line, but since the length dimension of the work W is much larger than the bending amount dimension, the measurement error between the two is large. This is a sufficiently negligible amount.

Thus, the first single arc A1 of the work W
The portion is sent to the supporting portion 31, and the supporting points p ₁ and p ₂ based on the previously measured initial bending amount data for each single arc portion are supported by the work supporting roller 31a at two points.
At this time, the support span L between the two work supporting rollers 31a is set by the support roller spacing adjusting mechanism 31c, and the separating operation of the work supporting roller 31a with respect to the work W is performed by the supporting roller separating / contacting mechanism 31b.

Then, by one pressing roller 32a located on the center line between the supporting spans L of the supported work,
A straightening load is applied to the single arc A1 portion. This load is applied from the control means 43 to the motor driver 32 of the pressurizing unit 32.
The servomotor 32d is driven by a command to f, and its rotational force is transmitted via the gear mechanism 32c to the ball screw device 32b.
The pressure is applied to the work by the pressure roller 32a, which is transmitted in the Y direction in proportion to the rotation speed of the servo motor 32d. As a result, the bending between the support spans L of the work is pressed in the opposite direction and gradually deforms.
At that time, the pulse signal output from the rotary encoder 32e in accordance with the deformation amount (Y direction displacement) is fed back to the control means 43 momentarily as displacement information for correcting the bending of the work through the pulse counter 44. At the same time, the load sensor 40 continuously outputs an analog load signal in proportion to the magnitude of the load, and the load sensor amplifier 41 outputs A / A.
It is fed back to the control means 43 via the D converter 42 as displacement information for bending correction. As described above, in the present invention, instead of directly measuring the deformation amount of the work W during straightening and pressing with the displacement meter, the servo motor 3 that drives the pressing roller is used.
The rotary encoder 32e provided in 2d measures indirectly. This has the advantage of avoiding situations where straightening loads, which can reach up to tens of tons, distort the entire device and affect accurate measurements.

As shown in FIG. 1A of the work W based on the current correction load data on the work and the deformation data of the work resulting from this which are fed back to the control means of the bending correction means 30 every moment. The load-deformation characteristics are recognized, stored in a storage unit (not shown), and displayed on the display device 48 as needed. The work is first elastically deformed by the straightening load, and then passes through the yield point A to reach the plastic deformation region. After that, the total deformation amount in which the elastic deformation amount and the plastic deformation amount are superposed from the pulse counter 44 to the control means. It will be fed back to 43.

Here, the straight line Y = aX in the elastic deformation area is interpolated into the plastic deformation area based on the load data and the displacement data fed back to the control means 43 in real time during the pressing by the pressing roller 32a. Then, the elastic deformation component calculating means 45 calculates the elastic deformation component equivalent amount aX of the work with respect to the current correction load detection value X. Then, the subtraction unit 46 subtracts the calculation result from the current total deformation amount data, and pressurization is performed while repeatedly comparing the subtraction result with the previously stored initial bending amount Yc. Eventually, the plastic deformation reaches the point B, the value of the difference between the total deformation amount Y _B and the elastic deformation amount corresponding amount aX _B (Y _B -aX _B) is consistent with the initial amount of flexure Yc (Y _B -aX _B = Yc). At that time, the control means 43 outputs a pressure stop command to the motor driver 32f. As a result, the drive of the servo motor 32d is reversed and the pressure roller 32a retracts, and the work W is deformed by the amount of true plastic deformation in which the amount of elastic deformation is canceled. That is, the maximum load X _{B can be} applied all at once with one straightening load, and the amount of plastic deformation substantially equal to the initial amount of bending Y _C can be applied to correct the bending of the single arc A1 portion. After that, the single arc A2 portion is continuously sent out to the bending correction system 2, and the same processing as described above is sequentially repeated, whereby the bending of the entire work W can be corrected efficiently.

FIG. 5 shows an example of the load-displacement characteristic diagram of the work obtained in this embodiment. In the above description, the load cell 40, which is the correction load detecting means for measuring the load of the pressure roller 32a, is used alone, but in consideration of the fact that the resolution decreases when a large pressure maximum load is applied. By setting a plurality of load cells in parallel to disperse the load applied to the load cells and ensure the single resolution, it is possible to achieve both the maximum load and the resolution.

Conventionally, for example, to correct the bending (maximum 0.4 mm) of the guide rail (width 20 mm × height 12.5 mm × length 4000 mm) of the linear guide device to 0.1 mm or less. Although it took 20 minutes, the apparatus of this embodiment could be completed in about 5 minutes. In addition, the straightening accuracy is ± ± for the specifications with a narrow range bending amount of 0.1 mm or less.
An accuracy of 20 μm or less could be secured. That is, it was found that the working time was 1/4 and the correction accuracy was improved by 60%.

FIG. 6 shows the comparison between the target amount (correction amount) of the straightening deformation of the work and the actual amount of deformation when the bending straightening of 19 sample works was tested by the straightening method of the present invention by the manual control. It is a graph. It was possible to correct the bending within the range of ± 19 μm (± 38%) with respect to the target deformation amount of 50 μm. A computer may be used as the control means of the present invention.

[0033]

As described above, according to the bending correction apparatus for a wire of the present invention, the bending of the metal wire is approximated to a series of single arcs, and the bending amount of each single arc is measured by the initial bending measuring means. And the longitudinal direction coordinates are obtained to obtain the required deformation amount per corrective support span in the bending correction means, and the correction load value is obtained by the bending correction means according to the load-displacement characteristic of the workpiece obtained based on this. The straightening load is applied while detecting the deformation amount and the deformation amount in real time. In this way, by correcting the bending of the work with one pressurization in accordance with the true plastic deformation amount in which the elastic deformation amount is canceled, there is an effect that it is possible to efficiently and accurately correct the bending.

[Brief description of drawings]

FIG. 1 (a) is a load for straightening a bend of a metal wire-
Deformation characteristic diagram, (b) is an explanatory view of the bending mode of the metal wire.

FIG. 2 is a plan view of an embodiment of the wire straightening device of the present invention.

FIG. 3 is a side view of FIG.

FIG. 4 is a system conceptual diagram of the same device.

FIG. 5 is a load-displacement characteristic diagram obtained in this example.

FIG. 6 is a comparison graph of the target amount of corrective deformation and the actual amount of deformation in the example of the present invention.

FIG. 7 is an example of a load-displacement characteristic diagram in a conventional bending correction work for a wire rod.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bending measurement system 2 Bending correction system 10 Initial bending measuring means 30 Bending correction means 40 Total deformation amount detection means 43 Control means 45 Elastic deformation amount calculation means

Claims (1)

[Claims] 1. An initial bend measuring means for sequentially measuring a bending amount and a position of the metal wire along a longitudinal direction of the metal wire, and the metal for each predetermined supporting span based on measurement data of the initial bend measuring means. Bending straightening means for applying a bending straightening load to the wire, straightening load detecting means for detecting the magnitude of the current straightening load by the bending straightening means, and elastic deformation amount and plastic deformation in the straightening direction of the metal wire by the current straightening load. Total deformation amount detecting means for detecting the total deformation amount of the amount, elastic deformation amount calculating means for calculating the elastic deformation equivalent amount of the metal wire with respect to the current correction load, and the elasticity from the measurement value of the total deformation amount detecting means. And a control means for stopping the load of the bending correction load by the bending correction means when the deformation equivalent amount is subtracted and the result is compared with the initial bending amount and the difference becomes zero. Straightening device of the wire, characterized in that there.