JP2007296579A - Release timing automatic control method of feeding device for press forming and automatic control equipment or feeding device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a release timing automatic control equipment which can reduce cost for release timing automatic control of press forming and improve measuring accuracy of response time. <P>SOLUTION: The control method employs a timing detector to output a release start signal/a release cancellation signal at a designated rotational angle of a press machine and a motion detector to detect a moving state of a release mechanism. A lapse of time from a predetermined starting point to each output is measured and necessary data for controlling release timing is obtained directly as time data. The automatic control of release timing is executed by correcting the response time through adjustment of each time data. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a release timing control method in a material feeding device for press working and an automatic control device or a feeding device using the method.

  In press work, a long and narrow strip-shaped material is often used, and a feed device such as a roll feeder or a grip feeder is used to supply the material to the press. FIG. 8 shows an outline of a conventional press line. The press machine 1 is supplied with a processing material 2 for press processing from an NC feeding device 3. The processed material 2 is wound around the uncoiler 4, and is unwound from the uncoiler 4 by the drive of the NC feeding device 3 and sent out to the press machine 1.

  In the press working, since a product is generally formed through a plurality of processing steps, it is necessary to accurately align the mold and the material in each press operation. First, pilot holes are formed at predetermined intervals in a band-shaped material by a punch supported by an upper mold of a mold. In the subsequent steps, the punch and the material are aligned by inserting a pilot pin formed in a predetermined positional relationship with the punch of the mold into the pilot hole.

The positioning with the pilot pin is performed immediately before the press working by lowering the upper die, but before this, the feed device releases the holding of the material, until the press working is finished and the pilot pin comes out of the pilot hole. The release operation to hold the material again must be performed.
Such an operation is performed based on an on / off signal from a cam switch interlocked with a crankshaft of a press machine.

  In FIG. 8, the NC feed device 3 is provided with a release air electromagnetic valve 3A. When the release start signal is input, the electromagnetic valve 3A is operated to release the feed rollers 3B and 3B for feeding the work material 2. When the release release signal is input, the feed rollers 3B and 3B are moved to the work material 2. The release operation is performed by pressure contact.

  Here, there is an operation delay time from when the feed device receives the release start signal until the drive source such as the motor or the air cylinder operates to move the mechanical parts and actually release the holding. This is the same when the release release signal is received and held again. The operation of the feeding device needs to allow for this operation delay time (hereinafter referred to as “response time”).

  In the NC feed device 3 of FIG. 8, a proximity switch 3C is provided below the material conveyance path. In this case, from the time when the release signal is output to the release air solenoid valve 3A from a control unit (not shown) built in the NC feed device 3, the feed rollers 3B and 3B are released, the material is loosened, and the proximity switch 3C. The time until the detection of approaching was measured as the response time.

Then, the rotational speed of the drive shaft of the press machine 1 is calculated from the output time interval of the pulse signal of the encoder 1A, and the angle of the drive shaft that should issue a release signal and the angle that should release the release signal from this rotational speed and the response time. When the rotation angle of the drive shaft coincides with the calculated angle, a release signal and a release release signal are output to the NC feed device 3 for control.
Japanese Patent Publication No. 02-047297

In the conventional release timing control device, the rotation of the drive shaft of the press 1 is first converted into a pulse signal by the encoder 1A, then calculated to the rotation speed by the microcomputer, and further converted into time. This result and the response time are adjusted, and the result is further calculated to calculate the rotation angle of the drive shaft to generate the signal. For this calculation, a relatively large microcomputer is required, which increases the cost.
The encoder 1A is usually a rotary encoder, but it is expensive.

  In the NC feed device 3 of FIG. 8, a proximity switch 3C is provided below the material conveyance path to detect the release of the feed rollers 3B and 3B by the looseness of the material. The proximity switch 3C may malfunction due to the guide state, and the measurement result of the response time may vary.

  Accordingly, an object of the present invention is to eliminate the need for a rotary encoder by using time data from the beginning as a measurement target, and to reduce the cost by realizing release timing control with a small controller. Another object of the present invention is to improve the measurement accuracy of response time.

  A plate material feeding method for press working according to the present invention includes a timing detector that outputs a reference signal, a release start signal, and a release signal when the rotation angle of the press machine corresponds to a preset reference point, release start timing, and release timing. In the release timing control method for the plate material feeding device for press working provided with the operation detector for detecting the operating state of the release mechanism and the electric control circuit, the electric control circuit uses the reference according to the input signal from the timing detector. Calculate the release start time / release time for the point, and compare the release start signal / release signal of the timing detector with the input signal from the release mechanism operation detector to calculate the response time of release start / release. Corresponding to the calculated release start time / release time and response time. It is characterized by correcting the release timing and over scan start timing to advance the response time duration.

  A plate material feeding method for press working according to the present invention includes a signal generator that outputs at least a reference signal corresponding to a preset rotation angle of a press, an operation detector that detects an operating state of a release mechanism, and an electric control circuit In the release timing control method for a plate material feeding apparatus for press working comprising: the electrical control circuit measures a response time from the input of a signal to the release mechanism until the release start or release is activated, and the reference signal The release start timing and release timing after elapse of the preset release start time and release time are corrected so as to be advanced by the response time.

  The press working plate material feeding method according to the present invention is characterized in that the timing detector detects an operation of sandwiching or releasing the plate material of the press working plate material feeding device. Moreover, the material processing method for press working according to the present invention can be incorporated into a transport device or an independent release timing automatic control device.

  According to the present invention, there is an effect of reducing the cost required for automatic release timing control by eliminating the need for a rotary encoder and realizing release timing control with a small controller. Furthermore, there is an effect of improving the accuracy of automatic release timing control by improving the measurement accuracy of response time.

  An embodiment of the present invention will be described with reference to FIGS. In this embodiment, a grip feeder 10 is used as a feeding device. Structures other than the portions shown in FIGS. 1 to 4 are basically the same as those with reference to FIG. In addition, the same reference numerals are used for parts common to the prior art.

A grip feeder 10 shown in FIG. 1 has a fixed clamp and a movable clamp, and is a device for alternately holding and feeding a material between two clamps. As indicated by the arrows in the figure, the fixed clamp 11 clamps / releases the workpiece 2, and the moving clamp 12 clamps / releases the workpiece 2, and moves forward / backward in the conveyance direction of the workpiece 2.
The fixed clamp 11 is driven by an air cylinder 13, and the air pressure of the air cylinder 13 is controlled by a release valve 14 provided in the middle of piping to an air source (not shown). The driving / control of the moving clamp 12 is the same and is not shown.

The air cylinder 13 is connected to a pressure switch 15 that functions as an operation detector that detects an operation state (clamping / opening) of the fixed clamp 11 serving as a release mechanism. The pressure switch 15 outputs an ON signal when the pressure in the air cylinder 13 becomes higher than the first set value set to 80% of the air source pressure, and the pressure in the air cylinder 13 is 20% of the air source pressure. When it becomes lower than the second set value set to%, an OFF signal is output.
Since the air pressure of the air cylinder that is directly linked to the movement of the clamp is measured, the operation of the release mechanism can be detected more accurately than in the prior art.

  The grip feeder 10 is connected with a control device 16 for NC control of the operation. An automatic release control device 17 that performs automatic control of the release operation is also provided. Here, the automatic release control device 17 is shown as a separate body from the control device 16 for the sake of explanation.

A disc-shaped cam 20 (A / B) that rotates in synchronization with the crankshaft of the press machine 1 and a limit switch 21 (A / B) corresponding to the cam 20 (A / B) are provided at the lower part of the press machine 1. It has been.
FIG. 2 shows details of this part. Reference numeral 22 denotes a crankshaft of the press machine, and the crankshaft 22 is connected to a sporocket 24 via a chain 23. The sporocket 24 is fixed to a shaft 25 for fixing the disc-shaped cams 20A and 20B. Limit switches 21A and 21B are fixed in contact with the outer peripheries of the disk-shaped cams 20A and 20B, respectively.
The disc-shaped cams 20A and B rotate according to the rotation angle of the crankshaft 22 of the press machine 1, and the limit switches 21A and B output signals according to changes in the outer diameter of the disc-shaped cam 20B.
In the present specification and claims, the rotation angle of the crankshaft 22 of the press machine 1 or the rotation angle directly corresponding to the rotation angle such as the disc-shaped cam 20 (A / B) is conveniently referred to as “the rotation angle of the press machine”. May be expressed.

The disc-shaped cam 20A and limit switch 21A output a control signal for the moving clamp 12 of the grip feeder 10. FIG. 2 shows a state in which the press machine 1 is at the top dead center. However, the limit switch 21A is turned off when the outer shape of the disc-shaped cam 20A is small, and the moving clamp 12 holds the workpiece 2 at this time. Controlled to send.
The limit switch 21A is turned ON when the outer shape of the disc-shaped cam 20A is large, and at this time, the moving clamp 12 is controlled so as to return the workpiece 2 to be taken.

  The disc-shaped cam 20B and the limit switch 21B output a control signal for the release operation of the fixed clamp 11 of the grip feeder 10. The limit switch 21B is turned off when the outer shape of the disc-shaped cam 20B is small, and the release starts with Ron when the limit switch 21B switches from ON to OFF, and the release with Roff when the limit switch 21B switches from OFF to ON. To do. In this way, the timing detector that outputs the release start signal / release signal is constituted by 20B and 21B.

  FIG. 3 is a block diagram according to the automatic release timing control of the present invention. The automatic release controller 17 includes an arithmetic unit 17A, a memory 17B, a clock 17C, and an I / O port for exchanging data with an external switch or the like. The memory 17B includes a ROM in which a program for control operation is recorded and a data recording RAM. The arithmetic unit 17A, the memory 17B, and the clock 17C work together to perform a timekeeping function and a timer function. The outputs from the limit switches 21A and 21B and the ON output and OFF output of the pressure switch 15 are input to the arithmetic unit 17A. Further, the initial condition, the operation mode setting of the feeder, and the like are input by the setting switch 26. A control signal is output to the release valve 14 from the arithmetic unit 17A.

  The concept of the release timing automatic control of the present invention will be described. In the present invention, the elapsed time from a predetermined reference point to each output is measured by the outputs of the limit switches 21A and 21B and the pressure switch 15 and the time counting function of the automatic release control device 17, and the data necessary for controlling the release timing. Directly as time data. Then, the response time is corrected by adjusting each time data, and the release timing is automatically controlled.

The timing chart of the present invention will be described with reference to FIG. The signal level of the limit switch 21A shown in the upper stage becomes H level at time a due to the rotation of the disc-shaped cam 20A accompanying the rotation of the crankshaft 22 and the turning on of the limit switch 21A accompanying the change in the outer diameter, and then the limit switch 21A is turned off. As a result, it becomes L level at time b.
Similarly, the signal level of the limit switch 21B shown in the middle is similarly set to L level at time c when the Mitt switch 21B is turned OFF, and then becomes H level at time d when the limit switch 21B is turned ON.
The signal level of the pressure switch 15 shown in the lower stage becomes H level at time e when the pressure of the air cylinder 13 becomes higher than the first set value and turns ON, and then becomes lower than the second set value of the time f pressure switch 15. When it is turned OFF, it becomes L level.

Here, time a when the limit switch 21A becomes H level is considered as a reference point, and the signal at this time is taken as a reference signal. The elapsed time from time a to time c is defined as release time T1. This is the elapsed time from the time a until the limit switch 21B becomes L level and the release start signal of the fixed clamp 11 is output.
The elapsed time from time c to time e is R1. This is the response time from when the release start signal is output at time c until the signal of the pressure switch 15 becomes H level and the operation of the air cylinder 13 is confirmed.

  If the time obtained by subtracting R1 from T1 is C1, C1 is the time obtained by correcting the response time from the release time. By correcting the release start timing so as to output the release signal of the fixed clamp 11 after the elapse of C1 from the time a, the release timing can be controlled in consideration of the response time of the air cylinder 13.

Similarly, the elapsed time from time a to time d is defined as release release time T2. This is the elapsed time from the time a until the limit switch 21B becomes H level and the release release signal of the fixed clamp 11 is output.
The elapsed time from time d to time f is R2. This is the response time from when the release release signal is output at time d to when the signal of the pressure switch 15 becomes L level and the operation of the air cylinder 13 is confirmed.

  When the time obtained by subtracting R2 from T2 is C2, C2 is a time obtained by correcting the response time from the release release time. By correcting the release release timing so that the release release signal of the fixed clamp 11 is output after C2 has elapsed from the time a, it is possible to control the release timing in consideration of the response time of the air cylinder 13.

  As described above, the release timing control method of the present invention obtains necessary data directly as time data, corrects the response time by adjusting each time data, and automatically controls the release timing. Since an expensive rotary encoder is not required and complicated calculation is not required, control can be realized with a small controller, and the cost required for automatic release timing control can be reduced.

  Next, the operation of the automatic release timing control apparatus according to the present invention will be described in detail. In FIG. 1, the work material 2 wound around the uncoiler 4 is pulled out and passed through the moving clamp 12 and the fixed clamp 11 of the grip feeder 10. At this time, the processed material 2 is not applied to the press 1.

Then, the press machine 1 is operated by selecting the “measurement operation” mode for correcting the response time by the setting switch 26 provided in the automatic release control device 17. The grip feeder 10 performs the release / release release operation of the fixed clamp 11 a predetermined number of times, and measures and stores each time data such as T1 and response time R1 shown in FIG. 3 in the memory 17B. After obtaining the average value of each data, C1 and C2 are calculated to determine the correction value of the release time / release release time.
Thereafter, the press machine 1 is stopped and the work material 2 is positioned at a predetermined position. The press machine 1 is operated by selecting the “operation” mode in which a normal pressing operation is performed by the setting switch 26.

  The above operation will be described with reference to a flowchart. FIG. 5 shows a flowchart of the measurement operation. In step S1, the number N of measurement is set by the setting switch 26, n = 1 is stored in step S2, and the release time T1 is measured in step S3. Specifically, T1 is measured by the count number of the clock 17c from time a to time c in FIG.

In step S4, the response time R1 is measured in the same manner as T1. In step S5, it is confirmed whether the number of repetitions n is equal to the number of measurements N. If not, 1 is added to n in step S6. The measurement is repeated until they match. In step S7, an average value of T1 is calculated, and in step S8, an average value of R1 is calculated. In step S9, the difference between the average value of T1 and the average value of R1 is calculated and C1 is calculated.
Although FIG. 5 shows the measurement of T1 · R1 and the calculation of C1, the measurement of T2 · R2 and the calculation of C2 are the same. Moreover, you may provide the step which detects the presence or absence of the processing material 2 previously.

FIG. 6 shows a flowchart of the press operation. In step S11, correction values C1 and C2 are read. In step S12, the output of the limit switch 21A is detected. In step S13, it is determined whether the output is H. When the output becomes H and time a in FIG. 4 is detected, the timer function of the automatic release control device 17 is started in step S14.
In step S15, the elapsed time of the timer is detected. In step S16, when the elapsed time coincides with the correction value C1, a release signal is output in step S17. Similarly, the elapsed time of the timer is detected in step S18, and when the elapsed time coincides with the correction value C2 in step S19, a release release signal is output in step S20.

  Since there are some variations in the operation of the air cylinder 13 and the pressure switch 15, an appropriate correction value can be determined by a plurality of operations and data acquisition. Further, since the response times R1 and R2 vary depending on the thickness of the processed material 2, correction according to the actual material used can be facilitated by correcting in advance by the measurement operation when the processed material 2 is set.

Next, another embodiment of the automatic release timing control apparatus according to the present invention will be described. The overall configuration of the second embodiment is common to the above-described best mode and the first embodiment, and does not have the disc-shaped cam 20A and limit switch 21A shown in FIG. The difference is in the control method.
This embodiment is suitable for a grip feeder in which a roll feeder or a moving clamp is driven by a ball screw.

FIG. 7 shows a timing chart of this embodiment. Here, the time point c at which the limit switch 21B is turned off is used as a reference point. Reference numerals common to FIG. 4 have the same meaning.
The elapsed time from when the limit switch 21B is turned OFF and the time c is detected until the disk-shaped cam 20B makes one revolution and the limit switch 21B is turned OFF again is defined as time T1 ′. Time T1 ′ is an elapsed time from the output of the release signal to the next output of the same signal.

  If the time obtained by subtracting R1 from T1 'is C1', C1 'is a time obtained by correcting the response time from the release time. By correcting the release start timing so that the release signal of the fixed clamp 11 is output after C1 'elapses from the time c, it is possible to control the release timing in consideration of the response time of the air cylinder 13.

  Similarly, the elapsed time from the time c until the disc-shaped cam 20B makes one revolution and the limit switch 21B is turned on again is defined as time T2 '. This is the elapsed time from the time c until the limit switch 21B becomes H level, after which the disc-shaped cam 20B makes one rotation, the limit switch 21B becomes H level again, and the release release signal of the fixed clamp 11 is output.

When the time obtained by subtracting R2 from T2 ′ is C2 ′, the release release timing is corrected so as to output the release release signal of the fixed clamp 11 after the time C2 ′ has elapsed from time c, and the release that allows for the response time of the air cylinder 13 The timing can be controlled.
As shown in the timing chart of FIG. 7, the control of the present embodiment is calculated in units of two cycles of the outputs of the limit switch 21B and the pressure switch 15, and is calculated in units of one cycle and compared with the previous data. You can also.

In this embodiment, the function at the reference time a in FIG. 4 is assigned to the time c, and the operation is the same as the operation shown in FIGS.
In this embodiment, T1 ′ changes according to the rotational speed or rotational angular velocity of the crankshaft 22 of the press machine 1. Therefore, in addition to obtaining the correction values C1 ′ and C2 ′ by performing the measurement operation shown in FIG. 5, the correction values C1 ′ and C2 ′ are obtained by measuring T1 ′, R1, T2 ′, and R2 at predetermined intervals during the press operation. It is also possible to make corrections according to changes in the rotational speed of the pressing machine during operation.

In the above embodiment, the operation of the fixed clamp 11 is detected by the pressure switch 15 connected to the air cylinder 13, but the present invention is not limited to this. The displacement of the air cylinder or the clamp can be detected by a proximity switch, and when the processing material 2 is a conductor, electrical conduction from the upper fixed clamp to the processing material 2 may be detected. According to these mechanisms, since the operation of the clamp mechanism can be detected more directly, the operation of the release mechanism can be detected with higher accuracy.
Further, in the above embodiment, the clamp release control is performed by a signal based on the disc-shaped cam and the limit switch. However, the means for generating the timing detection signal is not limited to this. For example, the mold is closed and the upper mold is closed. Rotation may be detected by detecting electrical continuity when the lower mold contacts, or by providing a slit or opening in the disc-shaped cam 20 and correspondingly providing a light source and a light receiving element. An electric control circuit may generate a signal and input the signal to the release mechanism.
Moreover, although the case where the grip feeder was used was shown in the above Example, the same control can be performed also with a roll feeder. The automatic release timing control device may be a single device independent of the transport device.

It is a figure which shows the outline | summary of the press work line which concerns on one Embodiment of this invention. It is a figure which shows the timing detection mechanism which concerns on one Embodiment of this invention. It is a block diagram of the automatic release control apparatus which concerns on one Embodiment of this invention. It is a timing chart of control output concerning one embodiment of the present invention. It is a flowchart of the measurement driving | operation which concerns on one Embodiment of this invention. It is a flowchart of the press operation which concerns on one Embodiment of this invention. It is a timing chart of the control output concerning other embodiments of the present invention. It is a figure which shows the outline | summary of the conventional press work line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Press machine 2 Processing material 3 NC feeder 4 Uncoiler 10 Grip feeder 11 Fixed clamp 12 Moving clamp 13 Air cylinder 14 Release valve 15 Pressure switch 16 Control device 17 Automatic release control device 20 Disc-shaped cams A and B
21 Limit switch A / B
22 Crankshaft 23 Chain 24 Sporocket 25 Axis 26 Setting switch

Claims (8)

A timing detector that outputs a reference signal, a release start signal, and a release signal at a rotation angle of the press corresponding to a preset reference point, release start timing, and release timing;
An operation detector for detecting the operating state of the release mechanism;
In a release timing control method for a plate material feeding apparatus for press working with an electric control circuit,
According to the input signal from the timing detector by the electric control circuit, to calculate the release start time and release time for the reference point,
Furthermore, the release start signal / release signal of the timing detector and the input signal from the release mechanism operation detector are compared to calculate the response time of release start / release,
And a release timing control method for a press working sheet material feeding device, wherein the release start timing and the release timing are corrected so as to be advanced by the response time corresponding to the calculated release start time / release time and response time. . A signal generator that outputs at least a reference signal corresponding to a preset rotation angle of the press,
An operation detector for detecting the operating state of the release mechanism;
In a release timing control method for a plate material feeding apparatus for press working with an electric control circuit,
In the electric control circuit,
Measure the response time from when a signal is input to the release mechanism until release start or release is activated,
A release timing control method for a press working sheet feeding apparatus, wherein the release start timing and the release timing after the release start time and the release time set in advance from the reference signal are corrected so as to be advanced by the response time. 3. The release timing control method for a press working sheet material feeding apparatus according to claim 1, wherein the operation detector detects an operation of sandwiching or releasing the plate material of the press working plate material feeding apparatus. A plate feeder for press working,
A timing detector that outputs a reference signal, a release start signal, and a release signal at a rotation angle of the press corresponding to a preset reference point, release start timing, and release timing;
An operation detector for detecting the operating state of the release mechanism,
Calculate the release start time and release time for the reference point according to the input signal from the timing detector,
Furthermore, the release start signal / release signal of the timing detector and the input signal from the release mechanism operation detector are compared to calculate the response time of release start / release,
And an electric control circuit for correcting the release start timing and release timing so as to be advanced by the response time corresponding to the calculated release start time / release time and response time. apparatus. A plate feeder for press working,
An I / O port that receives an input from a timing detector that outputs a reference signal, a release start signal, and a release signal when the rotation angle of the press machine corresponds to a preset reference point, release start timing, and release timing;
An I / O port for receiving an input from an operation detector that detects an operation state of the release mechanism;
Calculate the release time and release time according to the input signal from the timing detector,
Furthermore, the release start signal / release signal of the timing detector and the input signal from the release mechanism operation detector are compared to calculate the response time of release start / release,
And an electric control circuit for correcting the release start timing and release timing so as to be advanced by the response time corresponding to the calculated release start time / release time and response time. apparatus. 6. The press working plate material feeding device according to claim 4, wherein the operation detector detects an operation of sandwiching or releasing the plate material of the press working plate material feeding device. A plate material feeding device for press working that corrects the release start timing and release timing so as to advance the response time of the release mechanism,
A plate material feeding apparatus for press working, wherein the release mechanism is a clamp mechanism driven by an air cylinder, and an operation detector of the release mechanism detects a pressure change in the air cylinder. An automatic release timing control device for a press machine,
A timing detector that outputs a reference signal, a release start signal, and a release signal at a rotation angle of the press corresponding to a preset reference point, release start timing, and release timing;
An operation detector for detecting the operating state of the release mechanism,
Calculate the release start time and release time for the reference point according to the input signal from the timing detector,
Furthermore, the release start signal / release signal of the timing detector and the input signal from the release mechanism operation detector are compared to calculate the response time of release start / release,
And a release timing of the press machine, comprising an electric control circuit for correcting the release start timing and the release timing so as to be advanced by the response time corresponding to the calculated release start time / release time and response time. Automatic control device.

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