JP5350699B2 - Cutting monitoring device for cutting equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machining monitoring device for a machining apparatus that can detect a deteriorated state before breaking of a machining blade such as a drill, can monitor whether or not the machined state is good, and can be easily installed. <P>SOLUTION: The machining apparatus is used for forming holes in a printed board 14 with a drill 12 repeating a unit machining operation. The machining apparatus comprises a duct 15 that sucks cut chips 19 of a workpiece which has been machined, a light source 22 that radiates light into the duct, a photoreceiver 23 installed at a position through which the radiated light is passed and introduced, and a signal processor 25 comprising a means for detecting a change in output voltage of the photoreceiver 23 caused by the passage of the cut chips 19 through the duct, a means for detecting the number of times by which the level of a change in output voltage exceeds a given threshold value, and a means for monitoring the above number of times in the unit machining operation and the level of a variation in the number of times between the unit machining operations to perform the detection of a deterioration in the drill or monitoring of the state of machining and the determination of whether or not the machined state is good. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a cutting device using a cutting blade such as a drill, and more particularly to a cutting monitoring device of a cutting device that monitors deterioration and cutting state of the cutting blade.

  A large number of holes must be drilled in the printed circuit board for mounting electrical components, and drilling is performed. These processing apparatuses are being automated, and detection of breakage due to wear of a drill is indispensable for minimizing the occurrence of defective products. Conventionally, various methods as disclosed in Patent Documents 1 to 5 below have been developed as methods for detecting breakage of a drill.

  In Patent Document 1, a cutting powder detector detects that cutting powder passes through a duct during processing, determines that the drill is broken when there is no output from the detector during processing, and detects the damage. ing.

  In Patent Document 2, the breakage of the drill is detected by a change in the drive current value of the motor of the cutting apparatus, and in Patent Document 3, the breakage is detected by measuring the reaction force received from the workpiece when the cutting blade is sent during processing. doing.

  Further, in Patent Document 4, damage is detected by monitoring the temperature of the drill and the chuck of the drill from the radiated heat ray, and in Patent Document 5, damage is detected by monitoring the temperature of the drill blade surface and cutting powder with an infrared sensor. Is detected.

Japanese Examined Patent Publication No.59-43262 Japanese Examined Patent Publication No. 62-60221 JP-A-9-1499 Japanese Unexamined Patent Publication No. 2000-711 JP 2006-95656 A

  Recently, there is an increasing demand for high-precision machining with a small hole diameter. For this reason, in the method of detecting the deterioration of the drill by detecting the change of the load caused by machining as in Patent Documents 2 and 3, the detection accuracy is not sufficient because the machining load is small. In addition, if machining is performed with an increased load such as lowering the rotational speed in order to increase the detection accuracy, the machining accuracy is affected. On the other hand, in the method of detecting the temperature as in the methods of Patent Documents 4 and 5, the detection device can be installed without affecting the machining function of the cutting device itself, but the temperature of the surroundings is required, so temperature management is necessary. It becomes. Further, when the drill temperature detecting device is installed later in the cutting device, the normal cutting device needs to be significantly modified due to the configuration of the detecting device.

  The method of detecting the presence / absence of cutting powder from the duct as in Patent Document 1 is easy to install the detection device because the duct is usually already installed in the cutting device. However, since the method of Patent Document 1 detects the presence or absence of cutting powder, it cannot be detected until after the drill is broken. If the breakage of the drill occurs during the machining, the work piece will also be damaged, resulting in a defective product, and exchanging the drill after the breakage takes a processing time. Therefore, it is desirable to detect the deteriorated state before breakage and replace the drill. In addition, since the machining accuracy such as the hole diameter decreases when the drill is deteriorated, it is desirable to always monitor whether the machining state is appropriate.

  Accordingly, an object of the present invention is to detect a deteriorated state before breakage of a cutting blade such as a drill, to monitor the quality of a cutting state, and to be easy to install. Is to provide.

  In order to solve the above problems, a cutting monitoring device of a cutting device according to the present invention is a cutting device that performs cutting with a cutting blade that repeats a unit machining operation. A light source that irradiates light into the duct, a light receiver that is installed at a position where the irradiated light is incident upon being reflected or reflected, and the cutting powder is allowed to pass through the duct. Means for detecting a change in the output voltage of the photoreceiver by detecting the number of times the change amount of the output voltage of the photoreceiver exceeds a certain threshold, and the number of times in the unit machining operation and between each unit machining operation By monitoring the amount of change in the number of times, the deterioration of the cutting blade is detected or the state of the cutting process is monitored.

  Here, the cutting blade may be a drill.

  Further, the cutting powder may be set to pass through a transparent tube between the light source and the light receiver in the duct, the light source is a light emitting diode, and the light receiver is a photo diode. It may be a diode.

  Further, means for determining that the cutting blade has deteriorated when at least one of the number of times or the amount of variation is not within a predetermined range, or the number of times is within a predetermined range, And when the said fluctuation | variation amount exists in the predetermined fixed range, you may provide a means to determine that the state of the said cutting is in a favorable state.

  In this case, the relationship between the usage time of the cutting blade, the number of times, and the amount of variation is measured in advance, and a predetermined constant range of the number of times and a predetermined constant range of the amount of variation are determined by the measured value. You may decide.

  In addition, the number of times and the amount of variation in the unit machining operation using an unused cutting blade is measured every certain number of repetitions of the unit machining operation, whereby a predetermined constant range of the number of times and the variation A predetermined fixed range of quantities may be determined.

  Further, the number of times that the change amount of the output voltage of the light receiver exceeds a plurality of different threshold values may be detected.

  Further, it may be provided with means for detecting a frequency characteristic of a change in the output voltage of the light receiver and detecting a change in the capacity of the duct based on the change in the frequency characteristic.

  According to the present invention, there is also provided a cutting monitoring method for a cutting apparatus that performs cutting with a cutting blade that repeats a unit machining operation, wherein light is emitted in a direction across a duct that sucks cutting powder of a cut workpiece. The light irradiated to the cutting powder passing through the duct passes through or enters the reflected light or is reflected and detected by the light receiver, and the amount of change in the output voltage of the light receiver is a constant threshold value. And detecting the cutting blade deterioration or monitoring the state of the cutting process by monitoring the number of times in the unit machining operation and the fluctuation amount of the number of times between the unit machining operations. A cutting monitoring method for a cutting apparatus characterized by the above can be obtained.

  The inventors of the present invention have found that the number of changes in the receiver output due to the passage of the cutting powder through the duct and the magnitude of the variation in the number of each drilling change depending on the use state and the deterioration state of the drill. It is based on.

  As an example, when the diameter of the drill is within a certain range, when the drill is in a new state, the number of cutting powders, that is, the number of changes in the receiver output tends to be small. However, the number of times varies relatively greatly for each drilling process. When the drill is new, the cutting amount per one rotation of the drill is large. Therefore, it is considered that the number of times is small because the size of the cutting powder is large. In addition, since the amount of cutting per rotation is large, the amount of change in the output voltage of the receiver and the unit processing per unit processing depends on whether the cutting powder passes large or breaks when passing through the receiver portion. The number of changes in the output voltage varies. Since the total value of the amount of cutting by one drilling is almost constant, it is considered that the amount of fluctuation of the above number is increased by the variation of the size of the cutting powder when the cutting powder passes through the duct.

  On the other hand, when the drill is slightly worn, the number of changes described above increases, and the amount of change in the number of drills tends to decrease. This is considered to be because the amount of cutting per one rotation of the drill is reduced and the size of the cutting powder is stabilized.

  In addition, as the drill becomes worn with use, the number of changes described above further increases. This is considered to be because the amount of cutting per one rotation of the drill is reduced and the size of the cutting powder is reduced.

  However, the above-mentioned tendency changes depending on the processing conditions such as the diameter of the drill and the number of rotations of the drill, and the work piece. It is also necessary to change the criterion for determining the amount of variation for each unit machining.

  In addition, in order to identify the magnitude of the change in the output voltage of the light receiver that is considered to correspond to the size of the cutting powder, more detailed information can be obtained by detecting the number of times of each change using a plurality of threshold values. Will be.

  In the present invention, as described above, not only the presence or absence of cutting powder, but also the number of changes in the output voltage of the light receiver generated by the cutting powder passing through the duct, that is, the quantity that is considered to be proportional to the number of cutting powder. Is detected and monitored, and further, the amount of change in the quantity in each unit machining operation is monitored, thereby detecting the deterioration of the cutting blade or monitoring the state of the cutting process.

  According to the present invention, it is possible to detect a deteriorated state before breakage of a cutting blade such as a drill, to identify a quality of a cutting state, and to obtain a cutting monitoring device of a cutting device that can be easily installed.

  FIG. 1 is a view showing a cutting monitoring device of a cutting device for drilling a printed circuit board, which is a first embodiment of a cutting monitoring device of a cutting device according to the present invention, and a cutting device provided with the cutting monitoring device. FIG.

  In FIG. 1, a drill 12 is attached to a drilling machine 11 for drilling a printed circuit board 14 and the like, and the printed circuit board 14 installed on the moving stage 13 is moved to a predetermined position in accordance with a set program. And many holes are drilled by repeating one drilling operation which is a unit machining operation. Here, the cutting powder 19 generated with the drilling is sucked and discharged by the duct 15 provided with an opening in the vicinity of the drill. A light detection device 20 for detecting cutting powder is provided in the middle of the duct. The light detection device 20 includes a transparent tube 21 for transmitting light provided in the detection unit 16 of the duct, a light source 22 disposed opposite to the transparent tube 21, a light receiver 23, a light source 22, and a light receiver. And a housing 24 provided with a hole into which the transparent tube 21 is inserted.

  The output of the light receiver 23 is input to the signal processing device 25. The signal processing device 25 detects the change in the output voltage of the light receiver 23, and determines the number of times that the amount of change in the output voltage of the light receiver 23 exceeds a certain threshold. Means for detecting, means for monitoring the number of times in a unit machining operation and the amount of change in the number of times between unit machining operations, detecting the deterioration of the drill or monitoring the state of cutting and determining the quality of the machining state. I have.

  FIG. 2 is a diagram showing the configuration of the light source 22, the light receiver 23, and the signal processing device 25 in the present embodiment. In FIG. 2, the light source 22 is constituted by the light emitting diode 1 and its drive circuit 2, and the light is irradiated to the region through which the cutting powder passes. The light receiver 23 includes a photodiode 3 and an amplifier circuit 4, and the irradiated light is incident on the photodiode 3, and the output of the photodiode 3 is amplified by the amplifier circuit 4 and is supplied to the comparator 6 of the signal processing device 25. input. When cutting powder (a size of several to several hundred μm) passes between the light source 22 and the light receiver 23, the output voltage of the photodiode 3 is reduced by the passage time, so that the direct current component is removed and the amplifier circuit 4 The output waveform is a pulse waveform having a width of several μs to several hundreds μs. In the comparator 6, the amount of change in the output voltage of the amplifier circuit, that is, the height of the pulse is compared with a predetermined threshold value, and the number of pulses exceeding the threshold value is counted by the counter 8. 10 is sent.

  The processing determination circuit 10 compares the counted number of pulses and the fluctuation amount of the number of times per drilling with a predetermined deterioration reference frequency range and a predetermined deterioration reference fluctuation amount range. The drill deterioration information is also compared with a predetermined standard reference frequency range and a predetermined standard reference variation range, and the machining state information is output as a result.

  Here, it is determined that the drill has deteriorated when the measured number of times is not within the range of the deterioration reference number of times, and the fluctuation amount for each drilling of the number of times is not within the range of the deterioration reference fluctuation amount. Is output to the display lamp, alarm, or control display screen.

  The number of times of measurement and the amount of variation thereof are compared with a predetermined standard reference number of times range and a predetermined standard reference amount of variation range, respectively, and the number of times is within the range of the standard reference number of times, and the amount of variation Is within the range of the standard reference fluctuation amount, it is determined that the cutting state is in a good state, and the determination result is output to a display lamp or a screen of a control display.

  Here, for the printed circuit board to be processed and the drill to be used, first, the number of times and the amount of variation in the drilling operation using an unused drill are measured, thereby the above-mentioned number of times of deterioration, the amount of deterioration reference variation, Each range of the standard reference frequency and the standard reference variation amount can be determined. This initial measurement can be made every certain number of drilling times, every processing lot, or every certain period, such as every week.

  In addition, with respect to the printed circuit board to be processed and the drill to be used, the relation between the usage time of the drill and the number of times and the fluctuation amount, and the reproducibility thereof are measured in detail in advance, and the above ranges are determined by the measured values You may decide.

  Also, since the speed of change of the output voltage of the light receiver, that is, the frequency of the pulse depends on the speed at which the cutting powder is sucked and passed through the duct, the suction force of the duct is reduced by observing the pulse frequency. Can also be detected.

  FIG. 3 is a diagram showing a configuration of a light source, a light receiver, and a signal processing device used in the second embodiment of the cutting monitoring device of the cutting device according to the present invention. This embodiment is also a cutting monitoring device of a cutting device for drilling a printed circuit board as in the first embodiment, and the configuration of the cutting device provided with the cutting monitoring device is the same as that of FIG.

  However, in this embodiment, as shown in FIG. 3, in order to identify the magnitude of the change in the output voltage of the optical receiver that is considered to correspond to the size of the cutting powder, the number of times of each change is determined by two threshold values. Is detected. In FIG. 3, the pulse output from the amplifier circuit 4 is input to the comparator 46 and the comparator 47. In the comparator 46, a signal whose pulse height exceeds the threshold value B, and in the comparator 47, the pulse height is the threshold value. Signals exceeding A are output and input to counters 48 and 49, respectively, and pulses exceeding the respective thresholds are counted.

  The output of the comparator 46 is a pulse output exceeding the high threshold B, and the output of the counter 48 corresponds to the number of particles having a large particle diameter. The output of the comparator 47 is a pulse output that exceeds the low threshold A, and the output of the counter 49 corresponds to the total number of small particles and large particles. The outputs of these counters are input to the processing determination circuit 40, and the number and variation amount thereof fall within the respective ranges of the degradation reference count, the degradation reference variation amount, the standard reference count, and the standard reference variation amount as in the first embodiment. It is determined whether or not there is, and the determination result is output. However, in the present embodiment, since there are two thresholds for measuring the number of pulses, two of the above reference times are also determined.

  Empirically, if the drill deteriorates, the ratio of large particles increases, so the deterioration of the drill can be detected more accurately by monitoring the outputs of the above two counters, and the deterioration before the drill breaks more reliably. Can be detected.

  The comparator can be composed of a general comparator circuit using an operational amplifier or the like, and the counter can also be a general counter circuit.

  FIG. 4 is a diagram showing a configuration of a light detecting device for detecting cutting powder used in the third embodiment of the cutting monitoring device of the cutting device according to the present invention. This embodiment is also a cutting monitoring device of a cutting device for drilling a printed circuit board as in the first and second embodiments, and the basic configuration of the cutting device provided with the cutting monitoring device is the first. Or it is the same as that of 2nd embodiment.

  However, in the present embodiment, the optical system of the light detection device not only detects transmitted light as described above, but also receives light scattered by cutting powder or reflected light as shown in FIG. It is also arranged at a position to detect scattered light.

  In FIG. 4, the irradiation light 35 emitted from the light source 32 is applied to the cutting powder 39 passing through the transparent tube 31, and the transmitted light 36 enters the light receiver 33 placed in the transmission direction. On the other hand, the light reflected or scattered from the cutting powder 39 is incident on the light receiver 34 placed in a direction different from the transmission direction. The detection signals of the light receivers 33 and 34 are input to the signal processing device 38.

  Generally, the sensitivity differs between detection by transmitted light and detection by scattered light depending on the type, size, density, etc. of the particles, so in this embodiment, a receiver that provides high sensitivity is selected to detect cutting powder. It can be carried out. Even with detection by scattered light, the larger the particle, the greater the change in output voltage.

  In any of the above-described photodetection devices, the light from the light-emitting diode is directly applied to the cutting powder, and the transmitted light or reflected light is directly incident on the photodiode, but the lens is used. It is also possible to irradiate the converged light, or to allow the transmitted light and reflected light to converge using a lens and enter the photodiode. Furthermore, it is possible to increase the detection sensitivity by using a lens so that the region through which the cutting powder passes is imaged on the incident surface of the photodiode. 4 can also be inserted in the middle of a duct of a conventional cutting apparatus, similarly to the light detection device of FIG.

  As described above, according to the present invention, it is possible to obtain a cutting monitoring device of a cutting device that can detect deterioration of a cutting blade such as a drill and can determine whether a cutting state is good or not, and can be easily installed.

  Needless to say, the present invention is not limited to the above-described embodiment, and the arrangement, shape, and configuration of the light detection device are used to obtain the necessary detection sensitivity in accordance with the cutting device to be applied. The threshold value for detecting the number of changes in the output voltage of the receiver and the degradation standard can be changed according to the type of cutting blade and workpiece, the shape of the duct, the capability, etc. The number of times, the deterioration reference fluctuation amount, the standard reference frequency, the standard reference fluctuation amount ranges, and the like can be determined.

It is a figure which shows the cutting monitoring apparatus of the cutting apparatus for printed circuit board drilling which is 1st embodiment of the cutting monitoring apparatus of the cutting apparatus by this invention, The block diagram of the cutting apparatus which installed the said cutting monitoring apparatus It is. It is a figure which shows the structure of the light source in 1st embodiment, a light receiver, and a signal processing apparatus. It is a figure which shows the structure of the light source, light receiver, and signal processing apparatus which are used for 2nd embodiment of the cutting monitoring apparatus of the cutting apparatus by this invention. It is a figure which shows the structure of the light detection apparatus for cutting powder detection used for 3rd embodiment of the cutting monitoring apparatus of the cutting apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photodiode 2 Drive circuit 3 Photodiode 4 Amplifier circuit 25, 38, 45 Signal processing device 6, 46, 47 Comparator 8, 48, 49 Counter 10, 40 Judgment processing circuit 11 Drilling machine 12 Drill 13 Moving stage 14 Printed circuit board 15 Duct 16 Detector 19, 39 Cutting powder 20 Photodetector 21, 31 Transparent tube 22, 32 Light source 23, 33, 34 Light receiver 24 Housing 36 Transmitted light 37 Reflected light

Claims (10)

A cutting monitoring device of a cutting device that performs cutting with a cutting blade that repeats unit machining operations, a light source that irradiates light in a direction crossing a duct that sucks cutting powder of a cut workpiece, and the irradiated light source A light receiver installed at a position where the incident light passes through or is reflected and incident, and means for detecting a change in the output voltage of the light receiver due to the cutting powder passing through the duct; Number-of- times detecting means for detecting the number of times the amount of change in the output voltage of the light receiver exceeds a certain threshold, and the number of times in the unit machining operation based on the output of the number of times detecting means and the variation in the number of times between each unit machining operation or amount was measured, the amount of variation of the frequencies among the number and the unit machining operation in the unit processing operation, respectively, is in the range variation of the number of times range and predetermined a predetermined Or a includes a processing determining processing determination unit, cutting monitoring device cutting device, characterized in that the detection or monitoring of conditions of the cutting of the deterioration of the cutting edge.   A transparent tube forming a part of the duct in the suction direction is disposed in the duct, and the light source and the light receiver are disposed in a direction crossing a path of cutting powder passing through the transparent tube. The cutting monitoring apparatus for a cutting apparatus according to claim 1, wherein the apparatus is a cutting monitoring apparatus.   3. The cutting monitoring apparatus for a cutting apparatus according to claim 1, wherein the light source includes a light emitting diode, and the light receiver includes a photodiode. The processing determination means is configured such that when the number of times in the unit machining operation and the variation amount of the number of times between the unit machining operations are not within a predetermined number range and a predetermined number of variation amounts, respectively. The cutting monitoring device for a cutting apparatus according to any one of claims 1 to 3 , wherein it is determined that the cutting blade has deteriorated , and the determination result is output to an output means . The processing determination means is configured such that the number of fluctuations in the number of times in the unit machining operation and the number of fluctuations between the unit machining operations are within a predetermined number range and a predetermined number of fluctuations , respectively. The cutting monitoring device for a cutting device according to any one of claims 1 to 4, wherein the cutting processing state is determined to be in a good state, and the determination result is output to an output means. . The relationship between the usage time of the cutting blade and the number of times the amount of change in the output voltage of the light receiver in a unit machining operation exceeds a certain threshold and the amount of change in the number of times between unit machining operations is measured in advance. The cutting monitoring device for a cutting apparatus according to any one of claims 1 to 5 , wherein the predetermined number of times range and the range of fluctuation amount of the predetermined number of times are determined. The number of times the amount of change in the output voltage of the light receiver exceeds a certain threshold in the unit machining operation using an unused cutting blade for every certain number of repetitions of the unit machining operation, and the amount of change in the number of times between unit machining operations the measures, cutting whereby said predetermined number range, and the cutting device according to any one of claims 1-5, characterized in that in determining the scope variation of a predetermined number of times Monitoring device.   The cutting monitoring device for a cutting apparatus according to any one of claims 1 to 7, wherein the number of times the amount of change in the output voltage of the light receiver exceeds a plurality of different threshold values is detected.   9. The apparatus according to claim 1, further comprising means for detecting a frequency characteristic of a change in the output voltage of the light receiver and detecting a change in the capacity of the duct based on the change in the frequency characteristic. Monitoring device for cutting machine. This is a cutting monitoring method of a cutting apparatus that performs cutting with a cutting blade that repeats unit machining operations, and irradiates light in a direction crossing a duct that sucks cutting powder of a cut workpiece and passes through the duct. The light irradiated to the cutting powder to be incident or reflected and detected by the light receiver is detected by a light receiver, the number of changes in the output voltage of the light receiver exceeds a certain threshold, By monitoring whether the number of times in the unit machining operation and the variation amount of the number of times between the unit machining operations are within a predetermined number of times range and a predetermined number of times of variation, respectively, A cutting monitoring method for a cutting apparatus, wherein the deterioration of a cutting blade is detected or the state of the cutting process is monitored.

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