JP2019042857A - Grinder - Google Patents

Abstract

To provide a grinder that can grasp a wear state of a grind stone in an in-process.SOLUTION: A grinder 1 includes: a grinder body 10 for grinding a work W with a grinding wheel K while supplying grinding oil O thereto; a flow passage D through which the grinding oil O containing cutting chips of the work W which is generated by grinding flows; a magnetic field applying part (cutting chip coagulator 11) for applying a magnetic field so as to cross with a direction in which the flow passage D extends; and a detection device 12 for acquiring a parameter relating to a cutting chip coagulation body that is formed by the magnetic field.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a grinding machine.

  BACKGROUND ART In mass production of transmission gears for automobiles, gear grinding has been carried out with the aim of improving the tooth surface with high accuracy and surface quality by a gear grinding machine. In gear grinding for mass production, a method of creating a tooth profile by synchronously rotating a gear (workpiece) and a gear grinding wheel (tool) is used. The gear grinding wheel also wears like a normal grinding wheel, so dressing is performed to restore the grinding performance. The timing of this dressing can be determined empirically in most cases, so if it is possible to grasp the accurate abrasive wear state in-process, the performance of the grindstone can be utilized and productivity improvement can be expected.

  According to Patent Document 1, the load current value of the motor for rotating the grindstone is measured in a cylindrical grinding machine that grinds the surface of the work by rotating the grindstone and the work and bringing the grindstone into contact with the work. When the load current value exceeds a certain threshold value, it is judged that the sharpness of the grinding wheel is deteriorated, and the grinding wheel is applied to a dressing apparatus to perform dressing of the grinding wheel. There is.

Unexamined-Japanese-Patent No. 2000-263437

  There have been various studies on the measurement of the abrasive wear state. These measurement methods are classified into two types: those that directly measure the shape of abrasive grains on the surface of the grinding wheel by an optical method or contact method, and those that indirectly estimate the wear state of the grinding wheel from the torque applied to the spindle and power consumption. It can be divided roughly. The former method can measure the value close to the true value of wear, but when performing in-process measurement, the problem of interference between the sensor and the processing axis, and a structure that can withstand in the severe environment in the processing machine Implementation is difficult due to things that should be done. Further, with regard to the measurement of the gear grinding wheel, the thread-like shape of the grinding wheel makes high-speed direct measurement difficult. On the other hand, in the latter method, it is difficult to increase the S / N ratio due to the measurement characteristic that although interference between the sensor and the processing axis does not occur, the measurement is indirect.

  Further, as disclosed in Patent Document 1, the load current value of the motor that rotates the grindstone differs depending on the surface state of the grindstone. On the other hand, the load current value depends not only on the surface condition of the grinding wheel but also on the grinding conditions. Further, it is known that the load current amount fluctuates in a certain range due to various factors including the grinding state and the like. Therefore, when the load current value is increased by the grinding condition itself, the fluctuation amount of the load current value due to the change of the grinding wheel surface state becomes smaller than the fluctuation amount of the load current derived from the grinding condition. For this reason, the technical contents described in Patent Document 1 may not be applicable depending on the grinding conditions.

  An object of the present invention is to provide a grinding machine capable of grasping the wear state of a grinding wheel in process.

  According to the first aspect of the present invention, the grinder is a grinder main body for grinding a workpiece with a grinding wheel while supplying grinding oil, and a flow of the grinding oil including chips of the workpiece generated by grinding A path, a magnetic field application unit that applies a magnetic field crossing in a direction in which the flow path extends, and a detection device that acquires a parameter related to an aggregate of the chips formed by the magnetic field.

  Moreover, according to the 2nd aspect of this invention, the said detection apparatus is equipped with the camera installed so that imaging | photography of the aggregate of the said chip was possible.

  Further, according to the third aspect of the present invention, the detection device further analyzes the image data generated by the camera, and the size of the aggregate of the chips as a parameter related to the aggregate of the chips. And a parameter acquisition unit that acquires a parameter having a correlation with at least one of the volume change amounts of the chip aggregates.

  Moreover, according to the 4th aspect of this invention, the said detection apparatus is provided with the magnetic flux density detection sensor which measures the magnetic flux density of the said magnetic field.

  Further, according to the fifth aspect of the present invention, the detection device further includes, as a parameter related to the aggregate of the chips, the parameter based on the measurement result of the magnetic flux density of the magnetic field by the magnetic flux density detection sensor. A parameter acquiring unit is provided which acquires a parameter having a correlation with at least one of the size of the aggregate and the volume change amount of the aggregate of the chips.

  Moreover, according to the 6th aspect of this invention, the shape estimation part which estimates the shape of the said chip based on the parameter regarding the aggregate of the said chip is further provided.

  Moreover, according to the 7th aspect of this invention, the determination part which determines whether it should perform the measure which recovers the grinding performance of the said grinding stone based on the parameter regarding the aggregate of the said chip is further provided.

  According to the above-mentioned grinder, it is possible to grasp the worn state of the grinding wheel in process.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the grinding machine which concerns on 1st Embodiment. It is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 1st Embodiment, and a detection apparatus. It is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 1st Embodiment, and a detection apparatus. It is a figure which shows the function structure of the detection apparatus which concerns on 1st Embodiment. It is a figure which shows the processing flow of the detection apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the process of the detection apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the process of the detection apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the process of the detection apparatus which concerns on 1st Embodiment. It is a figure which shows the function structure of the detection apparatus which concerns on the modification of 1st Embodiment. It is a figure which shows the processing flow of the detection apparatus which concerns on the modification of 1st Embodiment. It is a figure which shows the structure of the chip | tip aggregation device which concerns on 2nd Embodiment. It is a figure which shows the function structure of the detection apparatus which concerns on 2nd Embodiment. It is a figure which shows the processing flow of the detection apparatus which concerns on 2nd Embodiment. It is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 3rd Embodiment, and a detection apparatus. It is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 4th Embodiment, and a detection apparatus. It is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 5th Embodiment, and a detection apparatus. It is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 6th Embodiment, and a detection apparatus.

First Embodiment
Hereinafter, the grinding machine according to the first embodiment will be described with reference to FIGS. 1 to 8.

  As shown in FIG. 1, the grinding machine 1 according to the first embodiment includes a grinding machine main body 10, a chip aggregation device 11, and a detection device 12. The grinding machine 1 according to the first embodiment is a so-called gear grinding machine that grinds a workpiece W to form a gear such as a spur gear.

The grinding machine main body 10 is a device for grinding the work W with the grinding wheel K while supplying the grinding oil O. As shown in FIG. 1, the grinder main body 10 is provided with a grinding spindle 101 which mounts and rotates the grinding wheel K, and a table 102 which supports and holds the work W from below. When the grinding wheel K contacts the workpiece W while rotating in synchronization, the workpiece W is ground and processed into a gear shape. Chips of the workpiece W are generated by this grinding. The material of the workpiece W and the chips thereof is, for example, iron, steel or the like.
In addition, the grinding machine main body 10 is provided with a coolant nozzle (hereinafter, referred to as a “nozzle”) which discharges the grinding oil O to the grinding portion during processing of the work W. With the grinding oil O discharged from the nozzle N, the smoothness of grinding, the removal of the chips of the workpiece W, and the heat removal of the workpiece W and the grinding wheel K are performed. The discharged grinding oil O flows to the chip aggregation device 11 described later through the flow path D while including the chips of the workpiece W generated by grinding.

The chip aggregating apparatus 11 aggregates chips of the work W contained in the grinding oil O in the flow path D through which the grinding oil O discharged by the grinding machine main body 10 flows to form an aggregate (cluster) thereof. . As shown in FIG. 1, the chip agglomerating apparatus 11 is attached around a flow path D drawn around a side wall surface or the like of the grinding machine main body 10.
The specific structure of the chip aggregation device 11 and the “aggregate of chips” will be described later.

(Structure of chip agglomeration device and detection device)
FIG. 2:, FIG. 3 is a figure which shows the structure of the chip | tip agglomerating apparatus which concerns on 1st Embodiment, and a detection apparatus, respectively.

  The detection device 12 includes a camera C installed in the chip aggregation device 11, and a computer 120 connected to the camera C. The computer 120 is a computer capable of acquiring image data generated by the camera C and performing various arithmetic processing based on the image data.

As shown in FIGS. 2 and 3, the chip agglomerating apparatus 11 according to the first embodiment includes a magnet M, which is a permanent magnet, and a yoke Y.
The magnet M and the yoke Y function as a magnetic field application unit that applies a magnetic field intersecting (orthogonal) in the direction (± X direction) in which the flow path D extends. That is, by arranging the yoke Y to extend from each end face of the magnet M in the up-down direction (± Z direction) to each end face in the up-down direction of the flow path D, magnetic lines of force generated by the magnet M flow path D Led up and down. As a result, a magnetic field is applied in the vertical direction of the flow path D (see "magnetic lines of force" shown in FIG. 3).
Here, the chips contained in the grinding oil O flowing in the flow path D are magnetic substances such as iron and steel, so the chips are attracted to the magnetic field applied to the flow path D. As a result, chip aggregates (clusters) are formed on the inner wall in the vertical direction (± Z direction) of the flow path D. Hereinafter, the aggregate of chips formed in the flow path D by the magnetic field is simply referred to as "aggregate".

  Further, as shown in FIG. 2, an observation window α is provided at a predetermined position of the flow path D (a position where the magnet M and the yoke Y are disposed). As shown in FIGS. 2 and 3, the camera C of the detection device 12 is disposed such that the optical axis of the camera C is substantially perpendicular to the plane of the observation window α. Thereby, the camera C can photograph the aggregate R formed on the inner wall of the flow path D from the outside of the flow path D.

(Functional configuration of detection device)
FIG. 4 is a diagram showing a functional configuration of the detection device according to the first embodiment.
As shown in FIG. 4, the detection device 12 has a computer 120 and a camera C. The computer 120 of the detection device 12 may be a general-purpose computer, and, as shown in FIG. 4, for example, is configured by a CPU 121, an operation unit 122, a display unit 123, a memory 124, a connection interface 125, and the like.

The CPU 121 is an arithmetic device that implements each function described later by reading a program or data onto the memory 124 and executing a process.
The operation unit 122 includes, for example, a mouse, a touch panel, a keyboard, and the like, receives various instructions from the operator, and inputs various operations to the CPU 121.
The display unit 123 is, for example, a liquid crystal display, an organic EL display, or the like, and displays the result of processing by the CPU 121.
The memory 124 is a volatile memory (RAM) used as a work area or the like of the CPU 121.
The connection interface 125 is an interface with an external device. In the present embodiment, the connection interface 125 is connected to a camera C (see FIG. 2 and FIG. 3) installed in the chip aggregation device 11.

The CPU 121 functions as an image acquisition unit 1211, a parameter acquisition unit 1212, and a determination unit 1213 by operating according to a program.
The image acquisition unit 1211 acquires image data generated by the camera C.
The parameter acquisition unit 1212 analyzes the image data generated by the camera C, and acquires parameters related to the aggregate R. In the present embodiment, the parameter acquiring unit 1212 determines, as the “parameter related to the aggregate R”, a volume change amount of the aggregate R (a degree of change in volume per unit time of the aggregate R (m ³ / sec)) Get correlated parameters. More specifically, the parameter acquiring unit 1212 sets the “white” area shown in the binarized image data G2 (see FIG. 6) described later as “a parameter having a correlation with the volume change amount of the aggregate R”. The amount of change in the number of pixels of (region β) (number of pixels per second) is acquired.
The determination unit 1213 determines whether or not to perform measures to restore the grinding performance of the grinding wheel K based on the parameters related to the aggregates R (for example, dressing of the grinding wheel K or replacement with a new grinding wheel K). Make a decision.

(Processing flow of detection device)
FIG. 5 is a diagram showing a processing flow of the detection device according to the first embodiment.
6-8 is a figure for demonstrating the process of the detection apparatus which concerns on 1st Embodiment, respectively.

  The processing flow shown in FIG. 5 is started, for example, from the time when an operation to start grinding is input to the grinding machine main body 10, and thereafter repeatedly executed at predetermined time intervals (for example, every one second). .

  When grinding in the grinder main body 10 is started, the CPU 121 (image acquisition unit 1211) outputs a signal instructing the camera C to perform imaging, and acquires captured image data G1 generated by the imaging ( Step S01). FIG. 6 shows an example of photographed image data G1 which is the image data acquired in step S01. As shown in FIG. 6, aggregates R formed in the flow path D are shown in the captured image data G1.

  Next, the CPU 121 (parameter acquisition unit 1212) processes the photographed image data G1 acquired in step S01 to acquire binary image data G2 (step S02). FIG. 6 shows an example of binarized image data G2 obtained by processing the photographed image data G1.

  Next, the CPU 121 (parameter acquisition unit 1212) generates a pixel of an area β (an area of “white” shown in the binarized image data G2 of FIG. 6) corresponding to the aggregate R in the binarized image data G2. Count the number. Then, the CPU 121 calculates the difference between the pixel count of the region β in the binarized image data G2 acquired this time and the pixel count of the region β in the binarized image data G2 acquired in the previous processing flow. The amount of change in the number (number of pixels / second) is calculated as the amount of change in volume of the aggregate R (step S03).

  Next, the CPU 121 (determination unit 1213) compares the amount of change in the number of pixels (number of pixels / second) calculated in step S03 with a predetermined determination threshold, and the amount of change in the number of pixels is greater than the determination threshold It is determined whether or not (step S05).

  If the amount of change in the number of pixels is equal to or greater than the determination threshold (YES in step S04), the CPU 121 ends the process without performing a special process (returns to step S01 after a predetermined time has elapsed). On the other hand, when the amount of change in the number of pixels is less than the determination threshold (NO in step S04), the CPU 121 causes the display unit 123 to display a warning image or the like to prompt the operator to dress or replace the grinding stone K (Step S05).

  Here, the determination process of step S04 will be described in detail with reference to FIGS. 7 and 8.

Generally, a relationship as shown in FIG. 7 is known between the "grindstone sharpness" and the "chip shape". That is, the shape of the chips changes due to the crush of the abrasive grains contained in the whetstone, clogging of chips (abrasion of the whetstone, etc. (Toshiyuki Obikawa et al., First-time processing) 1, pp. 108-109, (2016 )reference). More specifically, when the wear of the grinding wheel does not progress as immediately after dressing, a lot of long chips called "flow type" are generated. On the other hand, when the wear progresses through processing, short chips called "mush type" are easily generated. It is possible to grasp the wear state of the grinding wheel K based on the chip shape using such a relationship.
However, while the chips generated in the grinding machine main body 10 have a small width of about 10 μm and a large flow rate of the grinding oil O of about 100 L / min, the shape of the chips in the grinding oil O is directly It is difficult to observe. Therefore, as described above, the grinding machine 1 according to the present embodiment applies a magnetic field so as to intersect the extending direction (± X direction) of the flow path D in which the grinding oil O flows, and is drawn by the magnetic field The shape of the chip is estimated based on the volume change amount of the aggregate R to be cut.
Thereby, it is possible to estimate the wear state of the grinding wheel K based on the volume change amount of the aggregate R.

FIG. 8 is an example of the result of an experiment conducted to evaluate the relationship between the wear state of the grinding wheel and the volume change amount of the aggregate R. FIG. 8 shows the volume change of the aggregate R under the conditions of “after dressing” (grinding with a non-abrasive grinding wheel), “intermediate” and “abrasive” (grinding with a grinding wheel with progressive wear) The result of relative comparison of the amount (the amount of change in the number of pixels (pixels / second)) is shown (“after dressing” is “1”). As shown in FIG. 8, it can be read that the volume change amount of the aggregate R formed by the application of the magnetic field is larger in “after dressing” than in “wear”. That is, when the wear of the grindstone is not progressing, since there are many long chips (see “flow-type” chips) (see FIG. 7), many entanglements of chips are generated, and the volume change of the aggregate R is large. It is considered to be.
The determination threshold value of the change amount (pixel / second) of the number of pixels used in the determination process of step S04 is a wear state where measures should be taken to restore the grinding performance of the grinding wheel K based on the experimental result as in the example shown in FIG. Are defined in advance as values corresponding to

(Action / effect)
As described above, the grinding machine 1 according to the first embodiment is the grinding machine main body 10 for grinding the work W with the grinding wheel K while supplying the grinding oil O, and the grinding including chips of the work W generated by grinding. A flow path D through which oil O flows, a magnetic field application unit (a magnet M and a yoke Y) that applies a magnetic field intersecting in a direction in which the flow path D extends, and a detection device 12 that acquires parameters related to an aggregate R formed by the magnetic field And have.
With such a configuration, it is possible to estimate the shape of chips generated while the workpiece W is being ground, based on the parameters relating to the aggregate R. Therefore, the wear state of the grinding wheel K can be grasped in the in-process based on the estimated chip shape.

  Moreover, the detection apparatus 12 which concerns on 1st Embodiment is provided with the camera C installed so that imaging of the aggregate R was possible. Further, the detection device 12 analyzes the photographed image data G1 generated by the camera C, and detects a parameter (the number of pixels of “white” in the binarized image data G2) having a correlation with the volume change amount of the aggregate R. The computer 120 (parameter acquisition unit 1212) for acquiring the amount of change (number of pixels / second)) is provided.

  By doing this, it is possible to accurately measure the volume change amount of the aggregate R based on the image captured by the camera C. Then, based on the measured amount of change in volume of the aggregate R, it is possible to accurately estimate the wear state of the grinding wheel K.

In addition, the detection device 12 according to the first embodiment performs grinding based on a parameter (the amount of change in the number of pixels of “white” in the binarized image data G2) having a correlation with the amount of change in volume of the aggregate R. It further includes a determination unit 1213 that determines whether or not a measure should be taken to restore the grinding performance of the grinding wheel K.
By doing this, the detection device 12 can automatically determine whether to take measures to restore the grinding performance of the grinding wheel K and notify the operator.

(Modification of the first embodiment)
As mentioned above, although grinding machine 1 concerning a 1st embodiment was explained in detail, the concrete mode of grinding machine 1 is not limited to the above-mentioned thing, and various design in the range which does not deviate from a gist It is possible to make changes etc.
Hereinafter, a first modified example of the first embodiment will be described with reference to FIGS. 9 to 10.

FIG. 9 is a diagram showing a functional configuration of a detection device according to a first modified example of the first embodiment.
As shown in FIG. 9, the detection device 12 (CPU 121) according to the first modification of the first embodiment is replaced with the function of the determination unit 1213 of the first embodiment, and a shape estimation unit 1213A described below is described. Act as.
The shape estimation unit 1213A estimates the shape of the chip ("flow type", "pear type", etc. shown in FIG. 7) based on the parameters related to the aggregate R.

FIG. 10 is a diagram showing a process flow of a detection apparatus according to a first modified example of the first embodiment.
The processing flow shown in FIG. 10 is started from the time when an operation to start grinding is input to the grinding machine main body 10 as in the first embodiment (FIG. 5), and thereafter, every predetermined time It is repeatedly executed.

  When grinding in the grinding machine main body 10 is started, the CPU 121 (image acquisition unit 1211) outputs a signal instructing the camera C to perform photographing, and the photographed image data G1 generated by the photographing (see FIG. 6) ) Is acquired (step S11).

  Next, the CPU 121 (parameter acquisition unit 1212) processes the photographed image data G1 acquired in step S01 to acquire binary image data G2 (see FIG. 6) (step S12).

  Next, the CPU 121 (parameter acquisition unit 1212) counts the number of pixels of the region β corresponding to the aggregate R in the binarized image data G2, and the binarized image data G2 acquired in the previous processing flow The difference with the number of pixels of the region β in (ie, the change amount of the number of pixels (number of pixels / second)) is calculated (step S13).

  Next, the CPU 121 (shape estimation unit 1213A) specifies the shape of a chip corresponding to the amount of change in the number of pixels (number of pixels / second) calculated in step S13, and causes the display unit 123 to display the specified result. (Step S14). Here, the “chip shape” specified by the shape estimation unit 1213A is, for example, a1 to a2 (pixel / second) → “flow type”, a2 to a3 (pixel / second) → “mear type”,. And, it may be allocated by division of the change amount (pixel / second) of the predefined number of pixels.

As described above, the grinding machine 1 according to the first modification of the first embodiment estimates the shape of chips that can not be visually recognized based on the amount of change in the number of pixels (pixels / second), and The shape estimation result may be displayed on the display unit 123 to notify the operator.
By doing this, the operator can visually determine the chip shape estimation result displayed on the display unit 123 and determine whether or not a measure should be taken to restore the grinding performance of the grinding wheel K.

  Further, in another modification of the first embodiment, the grinding machine 1 does not include the determination unit 1213 and the shape estimation unit 1213A described above, and simply the amount of change in the number of pixels calculated by the parameter acquisition unit 1212 The calculation result of (pixels / second) may be displayed on the display unit 123. In this case, the operator may determine whether or not to take action to restore the grinding performance of the grinding wheel K by visually recognizing the calculation result of the displayed change amount of the number of pixels (pixels / second).

  Furthermore, in another modification of the first embodiment, the grinding machine 1 may simply display one or both of the photographed image data G1 and the binarized image data G2 on the display unit 123. . In this case, the operator may visually recognize the displayed photographed image data G1 and the binarized image data G2 to determine whether or not a measure to restore the grinding performance of the grinding wheel K should be taken.

  In addition, the grinding machine 1 (detection device 12) according to the first embodiment and its modification described above differs in the shape of chips (flow type, peel type, etc.) in that It has been described that attention is paid to the fact that there is a difference in “the amount of change in volume of aggregates”, which is an aspect of the present invention. However, the other modification of the first embodiment is not limited to this aspect.

For example, the grinding machine 1 according to the second modification of the first embodiment may pay attention to the “size of aggregate” as an example of the “parameter related to the aggregate R”.
That is, since the force of entanglement and joining of chips is different due to the difference in the shape of chips (flow type, nasty type, etc.), the flow of grinding oil O in flow path D is finally formed. The size of the aggregate R (the amount of saturation of the volume of the aggregate R (m ³ )) differs. That is, since the aggregate R finally formed in the flow path D becomes larger as the grinding performance of the grinding wheel K becomes higher, the wear state of the grinding wheel K is estimated based on the size of the aggregate R. can do.
In this case, the detection device 12 (parameter acquisition unit 1212) determines the number of pixels in the region β (the pixels of “white”) in the binarized image data G2 as a parameter having correlation with “size of aggregate R”. Number) may be obtained.

In addition, the grinding machine 1 according to the third modification of the first embodiment focuses on the “aspect ratio” of the aggregates R copied to the photographed image data G1 as an example of the “parameter related to the aggregates R”. It is also good.
That is, the longer the shape of the chips (the more “flow-type” chips), the easier it is to close the flow path D in a lengthwise direction, so the aspect ratio of the aggregate R formed according to the shape of the chips It is considered that the ratio of length to width is changed. Therefore, by forming aggregates R contained in the grinding oil O by application of a magnetic field, the wear state of the grinding wheel K is estimated based on the "aspect ratio" of the aggregates R copied to the photographed image data G1. be able to.

In addition, the grinding machine 1 according to the fourth modification of the first embodiment includes, as an example of the “parameter related to the aggregate R”, the “edge amount”, “edge direction” of the aggregate R copied to the photographed image data G1. (Or both).
That is, since the shape of the chips forming the aggregate R is different, the edge amount and the edge direction included in the captured image data G1 (difference in brightness between each pixel of the captured image data G1 and peripheral pixels of the pixel ( The magnitude and direction of the gradient) changes. Specifically, it is considered that the longer the chip, the longer the edge is detected. Therefore, by forming the aggregates R contained in the grinding oil O by application of a magnetic field, the grinding wheel K is formed on the basis of the “edge amount” and “edge direction” of the aggregates R copied in the photographed image data G1. Wear conditions can be estimated.

In addition, the grinding machine 1 according to the fifth modification of the first embodiment focuses on the “color tone” of the aggregates R copied to the photographed image data G1 as an example of the “parameter related to the aggregates R”. Good.
That is, in accordance with the wear state of the grinding wheel K, the frictional heat generated on the grinding wheel K and the work W changes. Specifically, as the grinding wheel K wears, the frictional heat generated at the time of grinding increases, and the workpiece W and its chips are heated. Then, it is considered that color unevenness of chips generated by heating increases. Therefore, by applying the magnetic field, the chips contained in the grinding oil O are aggregated and the color can be photographed so that the “color” of the aggregate R copied to the photographed image (photographed image data G1) The wear state of the grinding wheel K can be estimated on the basis of this.

  In the sixth modification of the first embodiment, the grinding machine 1 has already learned artificial intelligence as to whether or not to take measures to restore the grinding performance of the grinding wheel K based on the photographed image data G1. It is good also as an aspect equipped. In this case, it may be determined whether or not the learned artificial intelligence should take measures to restore the grinding performance of the grinding wheel K based on the sequentially acquired photographed image data G1.

Second Embodiment
Next, a grinding machine according to a second embodiment will be described with reference to FIGS. 11 to 13.

(Structure of chip agglomeration device and detection device)
FIG. 11 is a view showing the structure of a chip agglomerating apparatus and a detecting apparatus according to a second embodiment.
As shown in FIG. 11, the chip agglomerating apparatus 11 according to the second embodiment has a configuration similar to that of the first embodiment by the magnet M and the yoke Y.
As shown in FIG. 11, the detection device 12 according to the second embodiment includes a computer 120 and a Hall element H connected to the computer 120.
The Hall element H is a magnetic flux density detection sensor that measures the magnetic flux density of the magnetic field applied orthogonal to the extending direction of the flow path D by the magnet M and the yoke Y. The Hall element H is disposed between the outer surface of the flow passage D and the yoke Y as shown in FIG.

(Functional configuration of detection device)
FIG. 12 is a diagram showing a functional configuration of a detection device according to the second embodiment.
As shown in FIG. 12, the computer 120 (CPU 121) of the detection device 12 according to the second embodiment functions as a magnetic flux density acquisition unit 1211A, a parameter acquisition unit 1212 and a determination unit 1213.
The magnetic flux density acquisition unit 1211A acquires the magnetic flux density of the magnetic field applied to the flow path D through the Hall element H.
The parameter acquisition unit 1212 according to the second embodiment acquires a parameter having correlation with the volume change amount of the aggregate R based on the measurement result of the magnetic flux density of the magnetic field by the Hall element H. In the present embodiment, the “parameter having a correlation with the volume change amount of the aggregate R” is the change amount (Tesla / second) of the magnetic flux density acquired by the magnetic flux density acquisition unit 1211A through the Hall element H. .

(Processing flow of detection device)
FIG. 13 is a diagram showing a process flow of the detection device according to the second embodiment.

  The processing flow shown in FIG. 13 is started from the time when an operation to start grinding is input to the grinding machine main body 10 as in the first embodiment, and thereafter, every predetermined time (for example, 1 second) Is repeatedly executed.

  When grinding in the grinder main body 10 is started, the magnetic flux density acquisition unit 1211A acquires a detection signal input from the Hall element H, and acquires a magnetic flux density based on the detection signal (step S21).

  Next, the parameter acquisition unit 1212 calculates the difference between the magnetic flux density acquired this time in step S21 and the magnetic flux density acquired in the previous processing flow, and changes the amount of change in magnetic flux density (Tesla / sec) ) Is regarded as the volume change of the aggregate R (step S22).

  Next, the determination unit 1213 compares the amount of change in magnetic flux density (Tesla / second) calculated in step S23 with a predetermined determination threshold to determine whether the amount of change in magnetic flux density is equal to or greater than the determination threshold. Is determined (step S23).

  If the amount of change in magnetic flux density is equal to or greater than the determination threshold (YES in step S23), the CPU 121 ends the process without performing a special process (returns to step S21 after a predetermined time has elapsed). On the other hand, when the change amount of the magnetic flux density is less than the determination threshold (step S23: NO), the CPU 121 causes the display unit 123 to display a warning image or the like to prompt the operator to dress or replace the grinding stone K (Step S24).

  Here, the determination process of step S23 will be described in detail.

It is possible to estimate the shape of the chips and hence the wear state of the grinding wheel K based on the volume change amount of the aggregate R as described with reference to FIGS. 7 and 8.
Here, as shown in FIG. 11, magnetic lines of force of the magnetic field applied to the flow path D are applied in the vertical direction (± Z direction) while crosslinking the chips contained in the grinding oil O. Therefore, as the volume of the aggregate R formed in the flow path D increases, the ratio of the magnetic lines of force passing through the crosslinks of the chips increases, and the number of magnetic force lines passing through the inside of the flow path D from the upper end to the lower end increases. That is, the magnetic flux density detected through the Hall element H changes in response to the volume change of the aggregate R. By utilizing this relationship, it is possible to estimate the shape of the chips and the wear state of the grinding wheel K based on the amount of change in magnetic flux density (Tesla / sec).
The determination threshold value of the change amount (Tesla / second) of the magnetic flux density used in the determination process of step S23 is defined in advance as a value corresponding to the wear state where the measure to restore the grinding performance of the grinding wheel K should be performed.

(Action / effect)
As described above, the detection device 12 according to the second embodiment includes the Hall element H that measures the magnetic flux density of the magnetic field applied to the flow path D. Further, the detection device 12 acquires a parameter (change amount of magnetic flux density (Tesla / sec)) having correlation with the volume change amount of the aggregate R based on the measurement result of the magnetic flux density of the magnetic field by the Hall element H. The computer 120 (parameter acquisition unit 1212) is provided.

  By doing this, the volume change amount of the aggregate R can be measured based on the measurement result of the magnetic flux density by the Hall element H. Then, based on the measured amount of change in volume of the aggregate R, it is possible to accurately estimate the wear state of the grinding wheel K. Furthermore, since it is only necessary to measure the magnetic flux density through the Hall element H, the entire detection device 12 can be configured simply.

In addition, although the detection apparatus 12 (parameter acquisition part 1212) which concerns on 2nd Embodiment was demonstrated as what calculates the variation | change_quantity (Tesla / second) of magnetic flux density, it is not limited to this aspect in other embodiment. .
For example, the parameter acquisition unit 1212 according to the modification of the second embodiment multiplies the magnetic flux density acquired by the magnetic flux density acquisition unit 1211A by the effective detection area (m ² ) defined in advance to obtain the magnetic flux (amount The change amount of) may be calculated.

<Other Embodiments>
Next, grinding machines according to other embodiments will be described with reference to FIGS. 14 to 17. The grinding machine according to each embodiment described below differs from the grinding machines according to the first and second embodiments in the aspect of the detection device 12 respectively.

(Structure of chip agglomeration device and detection device)
FIG. 14 is a view showing the structure of a chip agglomerating apparatus and a detecting apparatus according to a third embodiment.
As shown in FIG. 14, the detection device 12 according to the third embodiment includes ultrasonic sensors F1 and F2 capable of transmitting and receiving ultrasonic waves. The ultrasonic sensors F1 and F2 are disposed so as to sandwich the flow path D on an axis inclined with respect to the extending direction (± X direction) of the flow path D. The ultrasonic sensors F1 and F2 are disposed to face each other so as to be able to receive ultrasonic waves transmitted from each other.

  The computer 120 of the detection device 12 is a time difference Δt1 between the time when the ultrasonic sensor F1 transmits the ultrasonic wave and the time when the ultrasonic sensor F2 receives the ultrasonic wave, and the time when the ultrasonic sensor F2 transmits the ultrasonic wave The time difference Δt2 of the time when the ultrasonic sensor F1 receives the ultrasonic wave is measured. And the computer 120 measures the flow velocity v of the grinding oil O which flows through the flow path D by calculating the difference ((DELTA) t2- (DELTA) t1) of two time difference.

The flow velocity v of the grinding oil O flowing through the flow passage D changes in accordance with the degree of blockage of the flow passage D due to the presence of the aggregates R. That is, as the volume of the aggregates R formed in the flow path D increases, the blockage in the flow path D increases and the flow velocity v of the grinding oil O flowing in the flow path D decreases.
The grinding machine 1 (detection device 12) according to the third embodiment considers the amount of change in the flow velocity v measured through the ultrasonic sensors F1 and F2 as the amount of volume change of the aggregate R using the above characteristics. The wear state of the grinding wheel K is estimated based on the amount of change in the flow velocity v.

FIG. 15 is a view showing the structure of a chip agglomerating apparatus and a detecting apparatus according to a fourth embodiment.
As shown in FIG. 15, the detection device 12 according to the fourth embodiment includes a liquid column type differential pressure gauge L. The liquid column type differential pressure gauge L is located upstream of the position where the yoke Y is disposed in the flow channel D (that is, the position where the aggregate R is formed) and the position where the yoke Y in the flow channel D is disposed. A liquid pipe L1 connecting to the downstream side and a liquid L2 which is filled in the liquid pipe L1 and which has a specific gravity larger than that of the grinding oil O.
Here, the pressure on the upstream side of the position where the yoke Y is disposed in the flow path D is referred to as “upstream pressure”, and the pressure on the downstream side of the position where the yoke Y is disposed in the flow path D is “downstream It is called "pressure". The liquid-column-type differential pressure gauge L can indicate the differential pressure (pi-po) between the upstream pressure pi and the downstream pressure po as a difference h in height of the liquid L2 in the liquid pipe L1.

The differential pressure (pi-po) of the grinding oil O flowing through the flow passage D changes in accordance with the degree of blockage of the flow passage D due to the presence of the aggregates R. That is, as the volume of the aggregates R formed in the flow path D increases, the blockage in the flow path D increases, and the differential pressure (pi-po) of the grinding oil O flowing in the flow path D increases.
The grinding machine 1 (detection device 12) according to the fourth embodiment uses the above-mentioned characteristics to make the amount of change in differential pressure (pi-po) measured through the liquid column type differential pressure gauge L smaller than that of the aggregate R. The amount of change in volume is considered, and the wear state of the grinding wheel K is estimated based on the amount of change in the differential pressure (pi-po).

FIG. 16 is a view showing the structure of a chip agglomerating apparatus and a detecting apparatus according to a fifth embodiment.
As shown in FIG. 16, the detection device 12 according to the fifth embodiment includes an electrical characteristic detection circuit Q formed by connecting a constant voltage source E, a voltmeter V, and a resistor Ri. The electric characteristic detection circuit Q is connected to the electrodes q1 and q2 disposed to face each other at the position where the yoke Y of the flow path D is disposed (that is, the position where the aggregate R is formed). The resistance value Rf [Ω] between the electrode q2 and the electrode q2 can be measured. In the case of the example shown in FIG. 16, the computer 120 of the detection device 12 calculates resistance Rf = (E / Vi−1) · Ri based on the measurement result Vi of the voltage measured from the voltmeter V. Calculate the value Rf.

The resistance value Rf between the electrode q1 and the electrode q2 disposed to face each other at the position where the yoke Y of the flow path D is disposed is formed on the aggregate R formed on the electrode q1 side and the electrode q2 side Changes according to the distance .DELTA.z between the That is, as the volume of the aggregate R formed in the flow path D increases, the distance Δz decreases and the resistance value Rf between the electrodes q1 and q2 decreases.
The grinding machine 1 (detection device 12) according to the fifth embodiment uses the above characteristics to aggregate the amount of change in the resistance value Rf between the electrodes q1 and q2 measured through the electrical characteristic detection circuit Q. The amount of change in volume of the grinding wheel K is estimated on the basis of the amount of change in resistance value Rf.

The detection device 12 according to the modification of the fifth embodiment calculates the capacitance value Cf (capacitance) [F] between the electrodes q1 and q2 instead of the resistance value Rf [Ω] between the electrodes q1 and q2. It is good also as an aspect which In this case, it is preferable that the electric characteristic detection circuit Q has an alternating voltage source instead of the constant voltage source E.
The capacitance value Cf between the electrode q1 and the electrode q2 changes in accordance with the distance Δz between the aggregate R formed on the electrode q1 side and the aggregate R formed on the electrode q2 side. That is, as the volume of the aggregate R formed in the flow path D increases, the distance Δz decreases, and the capacitance value Cf between the electrodes q1 and q2 decreases.
The grinding machine 1 (detection device 12) according to the modification of the fifth embodiment uses the above characteristics to change the amount of change in the capacitance value Cf between the electrodes q1 and q2 measured through the electrical characteristic detection circuit Q. The amount of change in volume of the aggregate R is considered, and the wear state of the grinding wheel K is estimated based on the amount of change in the capacity value Cf.

FIG. 17 is a view showing the structure of a chip agglomerating apparatus and a detecting apparatus according to a sixth embodiment.
As shown in FIG. 17, the detection device 12 according to the sixth embodiment includes an X-ray irradiation device X1 and an X-ray detection device X2. The X-ray irradiator X1 and the X-ray detector X2 are disposed to face each other across the flow path D in a direction (± Y direction) intersecting the extending direction of the flow path D.

  The X-ray irradiator X1 irradiates the channel D with X-rays by applying a predetermined voltage. The X-ray detection apparatus X2 detects the X-ray dose (transmitted X-ray dose Xi) transmitted through the flow path D among the X-rays irradiated from the X-ray irradiation apparatus X1.

Here, the main component of the aggregate R (chips) formed in the flow path D is iron, and the X-ray transmittance is lower than that of the grinding oil O. That is, as the volume of the aggregates R formed in the flow passage D increases, the X-ray dose (transmitted X-ray dose Xi) transmitted through the flow passage D decreases.
The grinding machine 1 (detection device 12) according to the sixth embodiment aggregates the variation of the transmitted X-ray dose Xi measured through the X-ray irradiation device X1 and the X-ray detection device X2 using the above characteristics The amount of change in volume of R is considered, and the wear state of the grinding wheel K is estimated based on the amount of change in the transmitted X-ray dose Xi.

  The various aspects (first to sixth modifications) described as the modifications of the first embodiment are also applicable to the second to sixth embodiments described above. is there.

Moreover, although the chip | tip aggregation device 11 (magnetic field application part) in the above-mentioned various embodiment was demonstrated as what consists of the magnet M and yoke Y which are permanent magnets, it is not limited to this aspect in other embodiment.
For example, in another embodiment, a winding (coil) and means for energizing the winding may be provided. In this way, the application of the magnetic field to the flow path D can be controlled as desired by the electromagnet.

  Moreover, although the grinding machine 1 which concerns on 1st Embodiment was demonstrated as what is a "gear grinding machine", in other embodiment, it is not limited to this aspect. That is, the grinding machine 1 which concerns on other embodiment may be an aspect by which the detection apparatus 12 which concerns on each embodiment mentioned above is equipped in grinding machines other than a gear grinding machine.

  In each embodiment described above, the processes of various processes of the computer 120 of the detection device 12 described above are stored in a computer readable recording medium in the form of a program, and the computer reads and executes the program. The above-described various processes are performed. The computer readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, and the like. Alternatively, the computer program may be distributed to a computer through a communication line, and the computer that has received the distribution may execute the program.

The program may be for realizing a part of the functions described above. Furthermore, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.
In addition, the computer 120 of the detection device 12 may be configured as a single computer having all the functions, or a plurality of computers having part of the functions and communicably connected to each other. May be composed of

  As mentioned above, although some embodiments concerning the present invention were described, all these embodiments are shown as an example, and it is not intending limiting the range of an invention. These embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and variations thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

DESCRIPTION OF SYMBOLS 1 Grinding machine 10 Grinding machine main body 101 Grinding spindle 102 Table 11 Chip aggregation device 12 Detection device 120 Computer 121 CPU
122 operation unit 123 display unit 124 memory 125 connection interface 1211 image acquisition unit 1211A magnetic flux density acquisition unit 1212 determination unit 1213 determination unit 1213A shape estimation unit W workpiece N nozzle O grinding oil K grinding wheel D flow path C camera Y yoke M magnet R Aggregate H Hall element α Observation window G1 Captured image data G2 Binarized image data β area F1, F2 Ultrasonic sensor L Liquid column differential pressure gauge L1 Liquid pipe L2 Liquid h Height difference pi Upstream pressure po Downstream side Pressure Q electrical property detection circuit q1, q2 electrode E constant voltage source Ri resistance V voltmeter Vi measurement result of voltage X1 X-ray irradiation device X2 X-ray detection device Xi transmission X dose

Claims (7)

Grinding machine main body which grinds work with grinding wheel while supplying grinding oil,
A flow path through which the grinding oil flows including chips of the workpiece generated by grinding;
A magnetic field application unit that applies a magnetic field intersecting the direction in which the flow path extends;
A detection device for acquiring parameters relating to the aggregates of the chips formed by the magnetic field;
Grinding machine equipped with The detection device
The grinding machine according to claim 1, further comprising a camera installed so as to be capable of capturing an aggregate of the chips. The detection device further comprises
The image data generated by the camera is analyzed and correlated with at least one of the size of the chip aggregate and the volume variation of the chip aggregate as a parameter related to the chip aggregate. The grinding machine according to claim 2, further comprising: a parameter acquisition unit configured to acquire a parameter having: The detection device
The grinding machine according to claim 1, further comprising: a magnetic flux density detection sensor that measures a magnetic flux density of the magnetic field. The detection device further comprises
Based on the measurement result of the magnetic flux density of the magnetic field by the magnetic flux density detection sensor, at least one of the size of the chip aggregate and the volume change amount of the chip aggregate as a parameter related to the chip aggregate The grinding machine according to claim 4, further comprising: a parameter acquisition unit that acquires a parameter having correlation with one of the two. The grinding machine according to any one of claims 1 to 5, further comprising a shape estimation unit configured to estimate a shape of the chips based on a parameter related to an aggregate of the chips. The determination part which determines whether it should perform the measure which recovers the grinding performance of the said grinding stone based on the parameter regarding the aggregate of the said chip is further provided, It is described in any one of the Claims 1-6. Grinder.