DE112022000851T5 - Onboard measurement system - Google Patents

Abstract

An on-board measuring system (H) has an on-board measuring device (20) and an output device (30). The output device (30) is configured to: obtain measurement data measured by the on-board measurement device (20) by moving a measurement position on a surface of a workpiece (W) relative to the workpiece (W) at least in a circumferential direction; performing a variety of analyzes related to the machining quality of the workpiece (W) using one of: a low frequency component; a high frequency component; and both the low frequency component and the high frequency component of the frequency components of the measurement data; and outputting a variety of analysis results.

Description

TECHNICAL FIELD

The present disclosure relates to an onboard measurement system.

STATE OF THE ART

Patent Literature 1 describes an example of an automatic dimension measuring device. The automatic dimension measuring device has a control unit that performs roundness analysis processing. The control unit controls a grinding machine to perform a sizing process on a workpiece based on measurement data measured by a sizing device, and analyzes a roundness of the workpiece based on the measurement data of the sizing device.

Citation list

PATENT LITERATURE

Patent literature 1 JP 2006 - 153 897 A

SUMMARY OF THE INVENTION

TECHNICAL PROBLEM

The automatic dimension measuring device described in Patent Literature 1 only analyzes roundness using measurement data obtained by a size determining device. When a workpiece is ground, it is desirable to measure a shape of the workpiece, a loop surface condition, an operating state of the grinder, and the like in order to obtain a machining quality of the workpiece ground by the grinder. Therefore, in general, a variety of devices for measuring the shape of the workpiece, the grinding wheel surface condition, the operating condition of the grinding machine and the like may be provided accordingly. As a result, an entire system including the grinding machine becomes complicated and expensive, and it takes time to obtain the machining quality.

An object of the present disclosure is to provide an on-board measurement system capable of obtaining machining quality of grinding at low cost and in a short time during the operation of the grinding process.

THE SOLUTION OF THE PROBLEM

An on-board measuring system has: an on-board measuring device provided in a grinding machine, the on-board measuring device being configured to measure the surface condition of a workpiece ground by a grinding wheel on the grinding machine and to provide measurement data accordingly output surface condition of the workpiece; and a delivery device configured to obtain the measurement data measured by the on-board measurement device by moving a measurement position on a surface of the workpiece relative to the workpiece at least in a circumferential direction; a variety of analyzes related to the processing quality of the workpiece ground by the grinding machine using one of: a low frequency component of frequency components of the measurement data; a high-frequency component of the frequency components of the measurement data, the high-frequency component of which is present in a frequency range higher than that in which the low-frequency component is present; and perform both the low frequency component and the high frequency component of the frequency components of the measurement data; and output a variety of analysis results.

According to the on-board measurement system, the on-board measurement device provided in the grinding machine can measure the surface condition of the workpiece, and the output device can perform a variety of analyzes related to the machining quality of the workpiece using one of the low frequency component, the high frequency component and both the low-frequency components and the high-frequency components of the measurement data obtained from the on-board measurement device. The output device can output a variety of analysis results obtained through the analysis.

Accordingly, in the on-board measurement system, a variety of analysis results can be output using, for example, only the low-frequency component of the measurement data, only the high-frequency component of the measurement data, or both the low-frequency component and the high-frequency component of the measurement data. In addition, in the on-board measurement system, for example, a variety of analysis results can be obtained by appropriately combining the low-frequency component and the high-frequency component, such as a first low-frequency component and a second low-frequency component of the measurement data, a first th high-frequency component and a second high-frequency component of the measurement data, the first low-frequency component and the second high-frequency component of the measurement data or the second low-frequency component and the first high-frequency component of the measurement data are output.

Therefore, according to the on-board measuring system, the on-board measuring device having a simple configuration for measuring the surface condition of the workpiece can be used, and thus the configuration of the system can be simplified and reduced in cost. Furthermore, according to the on-board measurement system, by appropriately combining the low-frequency component and the high-frequency component of the measurement data measured by the on-board measurement device, it is possible to shorten the time until the analysis results are obtained, compared with a case in in which measurement data from a variety of measuring devices are collected and analyzed.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1 is a top view showing a configuration of a grinder.
• 2 is a view for explaining an on-board measuring device.
• 3 is a flowchart showing grinding processing of the grinding machine.
• 4 is a view for explaining a surface texture of a workpiece.
• 5 is a view for explaining a surface texture caused by a grinding wheel.
• 6 is a view for explaining a surface texture caused by a grinding wheel.
• 7 a view for explaining a surface texture caused by a relative center-to-center vibration.
• 8th is a block diagram showing a configuration of an onboard measurement system.
• 9 is a view for explaining measurement of first measurement data. 10 is a view for explaining measurement of second measurement data.
• 11 is a block diagram showing a configuration of a first data analysis processing unit of an output device.
• 12 is a block diagram showing a configuration of a second data analysis processing unit of the output device.
• 13 is a block diagram showing a configuration of an output processing unit of the output device.
• 14 is a view for explaining an analysis result regarding a shape of a workpiece obtained by the output processing unit.
• 15 is a view for explaining an analysis result regarding a machine state obtained by the output processing unit.
• 16 is a view for explaining an analysis result (map) regarding a processing quality obtained by the output processing unit.
• 17 is a view for explaining an analysis result (map) regarding a machining quality obtained by the output processing unit.
• 18 is a view for explaining an analysis result (map) regarding a machining quality obtained by the output processing unit.
• 19 is a view for explaining an analysis result (map) regarding a machining quality obtained by the output processing unit.
• 20 is a view for explaining an analysis result (map) regarding a machining quality obtained by the output processing unit.

DESCRIPTION OF EMBODIMENTS

An on-board measurement system H is described below with reference to the drawings. Like from the 1 As can be seen, the on-board measurement system H has a grinder 10, an on-board measurement device 20 and an output device 30. The on-board measurement system H of the present embodiment has an image output device 40.

In the on-board measuring system H of the present embodiment, the on-board measuring device 20 measures a surface (grinding surface) of a workpiece W while or after being ground by the grinding machine 10, and the output device 30 performs various data analysis processes based on it the on-board measuring device 20 carries out measured measurement data to output a variety of analysis results regarding the machining quality of the workpiece W. The image output device 40 of the present embodiment outputs the plurality of analysis results output from the output device 30 as an image.

Here, as the measurement data detected by the on-board measuring device 20, for example, an acceleration of a vibration or a displacement (amplitude) of a vibration generated in accordance with a surface state (surface texture) of the workpiece W can be mentioned as an example. In addition, the on-board measuring device 20 can measure the measurement data directly or indirectly in contact with the workpiece W, and can measure the measurement data without coming into contact with the workpiece W (in a non-contact manner). In the present embodiment, a case in which the on-board measuring device 20 measures a displacement on the surface of the workpiece W and an acceleration related to the displacement will be described as an example.

(1. Grinding machine configuration 10)

Like from the 1 and 2 As can be seen, the grinding machine 10 has a bed 11, a grinding wheel 12, a wheel head 13, a headstock 14, a tailstock 15, a spindle table 16 and a control 17, and also has the on-board measuring device 20. Both ends of the workpiece W in a direction of a rotation axis are supported by the headstock 14 and the tailstock 15 to enable the workpiece W to rotate. In the present embodiment, a case in which the workpiece W has a columnar shape or a cylindrical shape is exemplified. The grinding machine 10 forms a shape of the workpiece W by bringing the grinding wheel 12 into contact with the surface (outer peripheral surface) of the rotating workpiece W and grinding the surface.

The grinding wheel 12 is supported by the wheel head so that it can be rotated about an axis parallel to a Z-axis. A disk head guide portion 11a is fixed to the bed 11, and the disk head 13 is supported by the disk head guide portion 11a so as to be movable in an X-axis direction. A rotating driving force is applied to the grinding wheel 12 by a grinding wheel rotation motor 12a controlled by the controller 17, and then the grinding wheel 12 rotates around a rotation axis. When the grinding wheel 12 moves in the X-axis direction, the grinding wheel 12 approaches the workpiece W spaced from the grinding wheel 12 in the X-axis direction and grinds the workpiece W.

On the bed 11, a spindle table guide portion 11b is mounted at a position spaced from the wheel head guide portion 11a in the X-axis direction. The spindle table guide portion 11b supports the spindle table 16 so that it is movable in a Z-axis direction. The headstock 14 and the tailstock 15 are intended to be directed towards each other on the spindle table 16. Both ends of the workpiece W are rotatably supported by the headstock 14 and the tailstock 15, a rotating driving force is applied to both ends by a spindle rotation motor 14a controlled by the controller 17, and then the workpiece W rotates.

(2. Configuration of the on-board measuring device 20)

The on-board measuring device 20 of the present embodiment is configured to have a sizing device. Like from the 1 and 2 As can be seen, the on-board measuring device 20 has a pair of measuring elements 21, which are contact portions configured to contact the surface of the workpiece W, and a pair of fingers 22 for supporting the measuring elements 21. As shown in FIG 2 As can be seen, the measuring elements 21 are provided so that they are in contact with the surface of the workpiece W at two points transverse to a rotation center (center of rotation) O of the workpiece W. The pair of fingers 22 has the measuring elements 21 at respective distal portions thereof and can be replaced by attaching and removing a proxy portion thereof. The on-board measuring device 20 is supported by an axial moving device 23 and is movable in an axial direction of the workpiece W, namely, in the Z-axis direction. The movement of the on-board measuring device 20 in the Z-axis direction is controlled by an axial movement control unit 24. The movement in the Z-axis direction is not limited to the movement controlled by the axial movement device 23. For example, it is also possible to use a switching function of a spindle and a tailstock shaft of the grinding machine 10.

The on-board measuring device 20 converts a mechanical displacement of the measuring element 21 into an electrical signal related to displacement and acceleration, thereby measuring an unevenness of an outer periphery of the workpiece W as the surface condition of the workpiece W. Here, the onboard measuring device 20 measures 20 an outer diameter of the workpiece W, namely the surface chencondition of the workpiece W in a frequency range of, for example, less than 60 Hz. Namely, the on-board measuring device 20 can measure a low-frequency component of the frequency characteristic of the surface condition of the workpiece W.

In addition, the on-board measuring device 20 has a high-frequency component measuring device 25 attached to at least one of the pair of fingers 22. The high-frequency component measuring device 25 of the present embodiment mainly has an acceleration sensor added by being attached to the finger 22, and measures an acceleration based on a displacement value in the surface state of the workpiece W in a frequency range of, for example, 60 Hz or more under the characteristics of the Surface state of the workpiece W. Namely, the high-frequency component measuring device 25 measures an acceleration associated with the displacement (vibration) generated in the finger 22 when the measuring elements 21 move relative to the workpiece W in a state in which the measuring elements 21 are with the surface of the workpiece W are in contact as a high-frequency component present in a frequency range higher than that in which the low-frequency component of the frequency characteristics of the surface state of the workpiece W is present.

Here, in the present embodiment, a case in which an acceleration sensor is attached (added) to the finger 22 and used as the high-frequency component measuring device 25 is exemplified. However, the high frequency component measuring device 25 is not limited to adding an acceleration sensor. For example, a device provided in a sizing device such as an analog output amplifier without a low-pass filter, a high-frequency digital output amplifier, or the like may be used. In this case, the on-board measuring device 20 measures the displacement instead of the acceleration, and thus processing for converting the acceleration into the displacement described later is not required.

(3. Grinding steps of the workpiece W by the grinding machine 10)

The grinding machine 10 grinds the workpiece W through a variety of steps consisting of 3 are visible. The grinding steps are classified according to a difference in grinding wheel feeding speed, and a rough grinding step St1, a fine grinding step St2, a micro grinding step St3 and a sparking step St4 are performed in this order. The grinding wheel feed speed in each step is expressed as: coarse grinding step St1 > fine grinding step St2 > micro grinding step St3 > sparking step St4. In the rough grinding step St1, a rough shape of the workpiece W is formed. In the subsequent fine grinding step St2 and the micro grinding step St3, a surface shape of the workpiece W is adjusted while the grinding wheel feed speed is reduced. In the last sparking step St4, a surface of the workpiece W is finished and the workpiece W is completed.

Here in the on-board measuring system H, the on-board measuring device 20 preferably measures the surface condition of the workpiece W during the grinding of the workpiece W from the rough grinding step St1 to the radio-out step Sp4 or after the radio-out step St4 in which the grinding is completed. The on-board measuring system H gives a variety of analysis results regarding the machining quality in the process to be described later, but the period in the process extends into a period until the workpiece W is removed from the grinding machine 10 with a period after the radio out step St4.

(4. Outline of the dispenser 30)

Next, an output device 30 will be described. Like from the 4 As can be seen, a surface texture S, which is one of the machining quality of the workpiece W ground by the grinding machine 10, is determined by various factors. Namely, the surface texture S of the workpiece W is formed by synthesizing a surface texture S1 and a surface texture S2, of which the surface texture S1 is caused by a grinding wheel such that a surface state of a grinding surface of the grinding wheel 12 is transmitted to the surface of the workpiece W, as shown by a solid line and a two-dot dash line in the 4 is indicated, and the surface texture S2 is caused by a center-to-center relative vibration (center-center relative vibration) when vibrations due to relative fluctuations between the grinding wheel 12 and the workpiece W are generated, namely, transmitted between centers, as shown by a dashed line in the 4 is displayed.

The surface texture S, namely the surface texture S1 and the surface texture S2, is measured as measurement data by the on-board measuring device 20. Here they measured using the measuring device 20 on board nen measurement data, a low-frequency component measured by the measuring element 21 and a high-frequency component measured by the high-frequency component measuring device 25. Therefore, it can be said that the surface texture S is determined by synthesizing the low frequency component and the high frequency component.

The surface texture S1 caused by the grinding wheel consists of surface textures in the circumferential direction and the axial direction of the workpiece W, and is formed by synthesizing a surface texture S11 of the high-frequency component to which a grinding wheel surface unevenness is transmitted and a surface texture S12 of a static workpiece reference radius with the low-frequency component, like from the 5 and 6 is visible. Here, the surface texture S11, for example, reflects a machining precision such as chatter vibration (hereinafter referred to as “chatter degree”), which is unevenness due to a grinding wheel of a portion of the workpiece W in the circumferential direction, and a variation degree of chatter (hereinafter referred to as “scale degree “ denoted) in the axial direction of the workpiece W.

Furthermore, the surface texture S2 caused by the center-to-center relative vibration is a surface texture of the one portion of the workpiece W in the circumferential direction, and is formed by synthesizing the low-frequency component and the high-frequency component, as shown in FIG 7 is visible. Namely, the surface texture S2 is formed by synthesizing a surface texture S21 that is a high-frequency component and a surface texture S22 that is a low-frequency component. Here, the surface texture S2 reflects, for example, the shape of the workpiece W, which depends on the machining accuracy such as roundness, runout of the surface machined by grinding, coaxiality and the like, and a machine state and a machining state of the grinding machine 10 such as vibration, self-excited Oscillation during machining and a spark-out effect depends.

Therefore, the output device 30 of the present embodiment extracts the low-frequency component and the high-frequency component from the measurement data measured by the on-board measurement device 20. The output device 20 performs various data analysis processes on the extracted (obtained) low-frequency component and high-frequency component, and outputs a variety of analysis results using various data analysis processes.

(4-1. Configuration of the output device 30)

Like from the 8th As can be seen, the output device 30 has a basic data acquisition unit 31, a first data analysis processing unit 32, a second data analysis processing unit 33 and an output processing unit 34. The output device 30 has, for example, a processor and a memory that stores instructions such as programs that, when passed through the processor, cause a computer to perform operations of the basic data acquisition unit 31, the first data analysis processing unit 32, the second data analysis processing unit 33 and the output processing unit 34.

(4-2. Basic data acquisition unit 31)

The basic data acquisition unit 31 acquires measurement data (displacement and acceleration) which is acquired by the on-board measuring device 20 during or after grinding. Like from the 8th As can be seen, the basic data acquisition unit 31 acquires in particular first measurement data K1 and second measurement data K2, which are output by the on-board measuring device 20, as first basic data D1 and second basic data D2, respectively.

Like from the 9 As can be seen, the on-board measuring device 20 first acquires the first measurement data K1 in a case where a measuring position for measuring the displacement and the acceleration according to the surface state of the workpiece W is relatively spiral in the circumferential direction and the axial direction with respect to the workpiece W is moved, and outputs the first measurement data K1 to the basic data acquisition unit 31. Namely, when the first basic data D1 is acquired in a state in which the work W is rotated, the measuring element 21 of the on-board measuring device 20 is brought into contact with the surface of the work W, and the on-board measuring device 20 is continuously scanned the axial moving device 23 moves in the axial direction of the workpiece W. The measuring position of the present embodiment is a position where the measuring element 21 of the on-board measuring device 20 comes into contact with the surface of the workpiece W. The first measurement data K1 includes measurement data (displacement) of the low-frequency component and measurement data (acceleration) of the high-frequency component measured by the high-frequency component measuring device 25.

Like from the 10 As can be seen, the on-board measuring device 20 acquires the second measurement data K2 for one circumference of the outer peripheral surface of the workpiece W in a case where the measuring position is moved to the same position (the same position in the axial direction) in the axial direction or is moved away in the axial direction without spirally moving the measurement position, and outputs the second measurement data K2 to the basic data acquisition unit 31. Namely, in a state in which the workpiece W is rotated, the measuring element 21 of the onboard measuring device 20 is brought into contact with the surface of the workpiece W, and the onboard measuring device 20 is placed in the same position of the workpiece W in the axial direction stopped by the axial movement device 23. The second measurement data K2 includes measurement data (displacement) of the low-frequency component and measurement data (acceleration) of the high-frequency component measured by the high-frequency component measuring device 25.

The basic data acquisition unit 31 acquires the first measurement data K1 discovered spirally as the first basic data D1. In addition, the basic data acquisition unit 31 acquires the second measurement data K2 for one revolution acquired at the same position in the axial direction as the second basic data D2. The basic data acquisition unit 31 outputs the first basic data D1 and the second basic data D2 to each of the first data analysis processing unit 32 and the second data analysis processing unit 33.

The first basic data D1 and the second basic data D2 are time series data related to the displacement and the acceleration. The first basic data D1 and the second basic data D2 are generally acquired as data from a time axis, but may be converted from a rotation angle of the workpiece W to time and a rotation speed of the workpiece W.

(4-3. First data analysis processing unit 32)

The first data analysis processing unit 32 extracts a low frequency component from the frequency characteristics of the first basic data D1 and the second basic data D2, and performs various data analysis processes to be described later on the extracted low frequency component to calculate a variety of first analysis results. Like from the 11 As can be seen, therefore, the first data analysis processing unit 32 mainly has a low-frequency component extraction unit 321, a spiral low-frequency waveform generation unit 322, a low-frequency center-center relative vibration waveform generation unit 323, and a workpiece reference radius calculation unit 324.

The low-frequency component extraction unit 321 performs a fast Fourier transform (hereinafter referred to as “FFT”) on the first basic data D1 acquired by the basic data acquisition unit 31, and extracts a low-frequency component D11 from the frequency characteristics of the first basic data D1. The low-frequency component extraction unit 321 performs the FFT on the second basic data D2 acquired by the basic data acquisition unit 31, and extracts a low-frequency component D21, which is the first analysis result, from the frequency characteristics of the second basic data D2. The low-frequency component extraction unit 321 extracts low-frequency components of the first basic data D1 and the second basic data D2, which are in, for example, a frequency range of less than 60 Hz (around 15 to 50 peaks as a waveform) as the low-frequency component.

The low-frequency spiral waveform generating unit 322 performs a reverse fast Fourier transform (hereinafter referred to as “reverse FFT”) on the low-frequency component D11 of the first basic data D1 extracted by the low-frequency component extraction unit 321. The first basic data D1 is the first measurement data K1 (displacement) acquired spirally along the outer peripheral surface (surface) of the workpiece W by the on-board measuring device 20. Accordingly, the low-frequency spiral waveform generating unit 322 calculates, as the first analysis result, a low-frequency spiral waveform SLW, which represents a waveform of the low-frequency component D11 of the displacement fluctuation, namely, a vibration of the workpiece W in a spiral direction.

The low-frequency center-to-center relative vibration waveform generation unit 323 performs the reverse FFT on the low-frequency component D21 of the second basic data D2 extracted by the low-frequency component extraction unit 321. The second basic data D2 is the second measurement data K2 (displacement) detected by the on-board measuring device 20 at the same position of the workpiece W in the axial direction. Accordingly, when the reverse FFT is performed on the low-frequency component D21 of the second basic data D2, a one-section low-frequency waveform (low-frequency waveform one Section), which represents the low frequency component D21 of the displacement fluctuation, namely the vibration of the workpiece W in the circumferential direction (one revolution).

The one-section low-frequency waveform represents, for example, a relative vibration (low-frequency center-center relative vibration) caused by a change in a relative position, namely a center-to-center distance between the grinding wheel 12 and the workpiece W, which is does not change greatly during grinding of a workpiece W, such as a pumping fluctuation in the grinding machine 10 or a setting accuracy of the workpiece W. Therefore, for a workpiece W, the one-section low-frequency waveform can be considered to be uniform along the axial direction of the workpiece W . Therefore, the low-frequency center-center relative vibration waveform generating unit 323 calculates the one-section low-frequency waveform obtained by performing the reverse FFT as the low-frequency center-center relative vibration waveform LDV, which is the first analysis result.

The workpiece reference radius calculation unit 324 calculates a workpiece reference radius R caused by the surface state of the grinding surface of the grinding wheel 12 transferred to the surface of the ground workpiece W by using the low-frequency spiral waveform SLW generated by the low-frequency spiral waveform generation unit 322. and the low-frequency mid-center relative vibration waveform LDV generated by the low-frequency mid-center relative vibration waveform generating unit 323. Specifically, the workpiece reference radius calculation unit 324 calculates the workpiece reference radius R as the first analysis result by subtracting the low-frequency center-to-center relative vibration waveform LDV from the low-frequency spiral waveform SLW.

As described above, the low-frequency center-to-center relative vibration waveform LDV is the one-section low-frequency waveform that is considered to be uniform in the axial direction of the workpiece W. Therefore, the workpiece reference radius calculation unit 324 calculates the workpiece reference radius R by adding (copying) the low-frequency center-to-center relative vibration waveform LDV by the number matching the spiral number C of the spiral-low-frequency waveform SLW and subtracting the resulting value from the spiral-low-frequency waveform SLW according to the following equation 1. $$\text{R}=\text{SLW}-\text{C}\times \text{LDV}$$

(4-4. Second data analysis processing unit 33)

The second data analysis processing unit 33 extracts a high-frequency component from frequency characteristics of the first basic data D1 or second basic data D2, and performs various data processing to be described later on the extracted high-frequency component to calculate a plurality of second analysis results. Like from the 12 As can be seen, the second data analysis processing unit 33 mainly has a spiral high-frequency component extraction unit 331, a one-section high-frequency component extraction unit 332, a spiral high-frequency wave formation unit 333, a high-frequency center-center relative vibration waveform generation unit 334, and a grinding wheel surface unevenness calculation unit 335.

The spiral high-frequency component extraction unit 331 performs the FFT on the first basic data T1 acquired from the basic data acquisition unit 31 and also converts acceleration data into displacement data, thereby extracting a high-frequency component from the frequency characteristics of the first basic data D1 as a spiral high-frequency component D12. The first basic data D1 is the first measurement data K1 (acceleration) acquired spirally along the outer peripheral surface of the workpiece W by the on-board measuring device 20. In addition, the spiral high-frequency component extraction unit 331, as the spiral high-frequency component D12, extracts frequency characteristics in a frequency range of, for example, 60 Hz or more of an upper limit frequency or less (approximately 50 to 500 peaks from a waveform) obtained by the on-board measuring device 20 as one High frequency components were detected.

The one-section high-frequency component extraction unit 332 performs the FFT on the second basic data D2 acquired by the basic data acquisition unit 31 and also converts the acceleration data into the displacement data, thereby extracting a high-frequency component D22 from the frequency characteristics of the second basic data D2. In addition, as one-section high-frequency component D221, the one-section high-frequency component extraction unit 332 extracts a high-frequency component obtained by excluding a grinding wheel rotation frequency component fg corresponding to a rotation speed of the grinding wheel 12 and the harmo never obtained from the extracted high frequency components D22.

The second basic data D2 is the second measurement data K2 (acceleration) detected by the on-board measuring device 20 at the same position of the workpiece W in the axial direction. Accordingly, the high-frequency component extracted from the second basic data D2 corresponds to the one revolution in the circumferential direction of the workpiece W, namely, a section of the workpiece W. Furthermore, the one-section high-frequency component extraction unit 332 extracts a frequency range of, for example, 60 Hz or more as the high-frequency component D22, and an upper limit frequency or less (about 50 to 500 peaks as a waveform) detected by the on-board measurement device 20 as a high frequency component.

The spiral high-frequency waveform generation unit 333 performs the reverse FFT on the spiral high-frequency component D12 of the first basic data D1 extracted by the spiral high-frequency component extraction unit 331. Accordingly, the spiral high-frequency waveform generation unit 333 calculates, as the second analysis result, a spiral high-frequency waveform SHW, which represents a waveform of the spiral high-frequency component D12 of the displacement fluctuation, namely, a vibration of the workpiece W in the spiral direction.

The high-frequency center-to-center relative waveform generation unit 334 performs the reverse FFT on the one-section high-frequency component D221 of the second basic data D2 extracted by the one-section high-frequency component extraction unit 332. Accordingly, when the reverse FFT is performed on the one-section high-frequency component D221 obtained by excluding the grinding wheel rotation frequency component fg and the harmony thereof from the high-frequency component of the second basic data D2, a one-section high-frequency waveform representing the one-section is obtained -High frequency component D221 represents the displacement fluctuation, namely the vibration of the workpiece W in the circumferential direction (one revolution).

The single-section high-frequency component D221 does not have the grinding wheel rotation frequency component fg corresponding to the rotation speed of the grinding wheel 12 and the harmony thereof. Therefore, the one-section high-frequency waveform represents the vibration affecting the surface texture S of the workpiece W (more specifically, the surface texture S22 in the surface texture S2 caused by the center-center relative vibration), which does not affect the grinding wheel rotation frequency component fg corresponding to Speed of the grinding wheel 12 and the harmony thereof. Examples of the vibration affecting the surface texture S22 of the workpiece W include rotation of a servomotor configured to control movement of the disk head 13 and the spindle table 16, vibration applied externally, self-excited chatter, and the like.

Accordingly, the one-section high-frequency waveform represents a relative vibration (high-frequency center-center relative vibration) caused by a change in the relative position, namely the center-center distance between the grinding wheel 12 and the workpiece W in the high frequency range. Consequently, for a workpiece W, the one-section high-frequency waveform can be considered to be uniform along the axial direction of the workpiece W like the one-section low-frequency waveform. Therefore, high-frequency center-center relative vibration waveform generation unit 334 calculated the one-section high-frequency waveform obtained by performing the reverse FFT as a high-frequency center-center relative vibration waveform HDV, which is the second analysis result.

The grinding wheel surface unevenness calculation unit 335 calculates a grinding wheel surface unevenness P caused by the surface state of the grinding wheel on the grinding wheel 12 transferred to the outer peripheral surface of the ground workpiece W using the high-frequency spiral waveform SHW generated by the high-frequency spiral waveform generating unit 333, and the high-frequency center-to-center relative vibration waveform HDV generated by the high-frequency center-to-center relative vibration wave formatting unit 334. Specifically, the grinding wheel surface unevenness calculation unit 335 calculates the grinding wheel surface unevenness P as the second analysis result by subtracting the high-frequency center-to-center relative vibration waveform HDV from the high-frequency spiral waveform SHW.

As described above, the high-frequency center-to-center relative vibration waveform HDV is the one-section high-frequency waveform that is considered to be uniform in the axial direction of the workpiece W. Therefore, the grinding wheel surface unevenness calculation unit 335 calculates the grinding wheel surface unevenness by H in/H counting (copying) the high-frequency center-to-center relative oscillation waveform HDV by the number matching the spiral number C of the high-frequency spiral waveform SHW and subtracting the resulting value from the high-frequency spiral waveform SHW according to the following equation 2. $$\text{P}=\text{SHW}-\text{C}\times \text{HDV}$$

(4-5. Output processing unit 34)

The output processing unit 34 may process and output a plurality of analysis results using a plurality of first calculation results calculated by the first data analysis processing unit 32 and a plurality of second analysis results calculated by the second data analysis processing unit 33. A variety of the analysis results to be output are described below as an example.

The plurality of analysis results output by the output processing unit 34 are related to the machining quality of the workpiece W ground by the grinding machine 10. Regarding the machining quality, a shape (machining accuracy) of the workpiece W such as the roundness of the workpiece W, the runout of the surface machined by the grinding, the coaxiality of the workpiece W, and the like related to the above-mentioned surface texture S2 can be exemplified become. In addition, a machining state of the grinding machine 10 and a machining state of the grinding machine 10 in relation to the machining quality can be exemplified. In addition, a machining state of the grinding machine 10 and a machine state of the grinding machine 10 in relation to the machining quality can be exemplified. The machining state exists in the machining accuracy, and examples thereof are a state of sparking and a sharpness state of the grinding wheel 12. Examples of the machine state are a vibration (mechanical vibration) of the grinding machine 10.

The machining quality, the machining condition and the machine condition are analysis results obtained using the second measurement data K2 (second basic data D2) measured by the on-board measuring device 20 at the same position in the axial direction during grinding of the workpiece W . Therefore, these analysis results are output for each processing of grinding the workpiece W by the grinding machine 10, namely for all the workpieces W.

Examples of machining quality are the surface texture S (surface texture S1) and the line roughness of the workpiece W, which are present in the machining accuracy. The machining quality (machining accuracy) is a kind of analysis results obtained using the first measurement data K1 (first basic data D1) measured in the circumferential direction and the axial direction of the workpiece W and the second measurement data K2 (second basic data D2) , which are measured at the same position in the axial direction by the on-board measuring device 20 after the workpiece W is ground. Therefore, these analysis results are appropriately output, for example, after the workpiece W is ground as necessary.

Like from the 13 As can be seen, the output processing unit 34 of the present embodiment has a shape analysis output unit 341 that outputs an analysis result related to a machining quality, a machining state output unit 342 that outputs an analysis result related to a machining state, a machine state output unit 343 that outputs an analysis result related to a machine state, and a map generation output unit 344, which outputs analysis results related to machining quality.

The shape analysis output unit 341, the machining state output unit 342 and the machine state output unit 343 use the low frequency component and the high frequency component of the second measurement data K2 (second basic data D2) measured by the on-board measuring device 20 at the same position of the workpiece in the axial direction. In addition, the map generation output unit 344 uses the low-frequency component and the high-frequency component of the first measurement data K1 (first basic data D1) measured in the circumferential direction and the axial direction of the workpiece W, and the low-frequency component and high-frequency component of the second measurement data K2 (second basic data D2), which are measured at the same position of the workpiece W in the axial direction by the on-board measuring device 20.

The shape analysis output unit 341 obtains a low-frequency center-center relative vibration waveform LDV, which is the first analysis result, from the first data analysis processing unit 32 (low-frequency center-center relative vibration waveform generation unit 323), and obtains a high-frequency center-center relative vibration waveform HDV, which is the second analysis result, from the second data analysis processing unit 33 (high-frequency center-center relative vibration waveform generating unit 334). The shape analysis output unit 341 synthesizes (adds) the low-frequency center-center relative vibration waveform LDV and the high-frequency center-center relative vibration waveform HDV to output the roundness of the workpiece W in a section and the runout of the grinded surface as an analysis results A1, like from the 14 is visible. For example, when a variety of quantities of roundness and runout in the axial direction of the workpiece W are analyzed, the coaxiality of the workpiece W can be output.

To obtain a grinding effect from each of the grinding steps resulting from the 3 As can be seen, to evaluate, the machining state output unit 342 outputs, as an analysis result A2, a state of a speed ratio, which represents a ratio of speeds of the grinding wheel 12 and the workpiece W. Therefore, the machining state output unit 342 acquires the high-frequency component D22 of the second basic data D2 as the second analysis results from the second data analysis processing unit 33 (single-section high-frequency component extraction unit 332) for each grinding step.

For example, when a grinding effect of the sparking step St4 is evaluated, the machining state output unit 342 outputs, as the analysis result A2, a ratio (fg2/fg1) of a grindstone rotational frequency component fg2 in the sparking out step St4 to a grinding wheel rotational frequency component fg1 in the rough grinding step St1, which is selected from the 3 is visible. In this case, it can be evaluated that the grinding effect of the spark-out step St4 becomes higher the closer the output analysis results A2 (fg2/fg 1) gets to "0", and the grinding effect of the spark-out step St4 is lower the closer the analysis results A2 are (fg2/fg1) to “1”.

The machine state output unit 343 acquires the low-frequency component D21 of the second basic data D2 as the first analysis result from the first data analysis processing unit 32 (low-frequency component extraction unit 321), and acquires the high-frequency component D22 of the second basic data D2 as the second analysis result from the second data analysis processing unit 33 (single-section high-frequency component extraction unit 332). . How then from the 15 As can be seen, the machine state output unit 343 outputs a relationship between a frequency change and an amplitude as an analysis result A3. In one in the 15 In the diagram shown, an amplitude indicated by a black square and a frequency corresponding to the amplitude indicate a vibration state caused by a loop disk, and other amplitudes and frequencies corresponding to the other amplitudes indicate mechanical vibrations.

The map generation output unit 334 generates and outputs a map representing the surface texture S (surface texture S1) of the workpiece W in the circumferential direction and the axial direction. Therefore, the map generation output unit 344 obtains the grinding wheel surface unevenness P, which is the second analysis result, from the second data analysis processing unit 33 (grinding wheel surface unevenness calculation unit 335). Like from the 16 As can be seen, the map generation output unit 344 generates a map M1 representing the surface structure S11 due to the grinding wheel surface unevenness P caused by the grinding wheel, and outputs the map M1 as an analysis result A4.

The map generation output unit 344 obtains from the first data analysis processing unit 32 (work reference radius calculation unit 324) a work reference radius R, which is the first analysis result. Like from the 17 As can be seen, the map generation output unit 344 generates a map M2 representing the surface texture S12 based on the workpiece reference radius R caused by the grinding wheel, and outputs the map M2 as the analysis result A4.

In addition, the map generation unit 344 synthesizes (adds) the map M1 and the map M2. Like from the 18 As can be seen, the map generation output unit 344 accordingly generates a map M3 representing the surface texture S1 caused by the grinding wheel, and outputs the map M3 as the analysis result A4.

In the present embodiment, the map M1 representing the surface texture S11 and the map M2 representing the surface texture S12 are synthesized to generate the map M3 representing the surface texture S1 caused by the grinding wheel. However, the map generation output unit 344 may also generate a map representing the surface texture S of the workpiece W by further synthesizing the surface texture S2 caused by the center-center relative vibration with the generated map M3.

In this case, the map generation output unit 344 acquires the high-frequency center-center relative vibration waveform HDV from the second data analysis processing unit 33 (high-frequency center-center relative vibration waveform generation unit 304), and generates a map M4 representing the surface texture S21 based on the high-frequency center-center relative vibration waveform HDV represents, which is caused by the center-center relative oscillation, as can be seen from the 19 is visible. The map generation output unit 344 obtains the low-frequency center-center relative vibration waveform LDV from the first data analysis processing unit 32 (low-frequency center-center relative vibration waveform generation unit 323), and generates a map M5 representing the surface texture S22 based on the low-frequency center-center relative vibration waveform LDV represented by the center-center relative oscillation is generated, as can be seen from the 20 is visible. The map generation output unit 344 can finally generate a map representing the surface texture S of the workpiece W by further generating the map M4 and the map M5 representing the surface texture S2 caused by the center-center relative vibration with the map M3 representing the surface texture S1 represents, which is caused by the loop disk, synthesized (added).

The analysis result A4 output by the map generation output unit 344 is not limited to the generated maps M1 to M3 (furthermore the generated maps M4 M5), and the analysis result A4 may also output other analysis results A4 based on the generated core maps M1 to M5 . For example, the map generation output unit 344 may output the machining accuracy represented by the chatter degree, the scale degree, or the like as the analysis results A4 based on the map M1 representing the surface texture S11.

The output processing unit 34 outputs a variety of analysis results to the image output device 40. Accordingly, the image output device 40 displays each of the plurality of acquired analysis results on a display, for example.

As can be understood from the above description, according to the on-board measuring system H, the on-board measuring device 20, which is formed using the sizing device, measures due to the grinding machine 10 provided and the high-frequency component measuring device 25 attached to the sizing device , the surface condition of the workpiece W, and the output device 30 can perform a variety of analyzes related to the machining quality of the workpiece W using the low-frequency component and the high-frequency component of the first measurement data K1 (first basic data D1) and the low-frequency component and the high-frequency component of the second measurement data K2 ( second basic data D2), which is obtained from the on-board measuring device 20.

The output device 30 can output a variety of analysis results A1 to A4 obtained through the analysis. Accordingly, according to the on-board measurement system H, the on-board measurement device 20 with a simple configuration can be used for measuring the surface condition of the workpiece W, and thus the configuration of the system can be simplified and reduced in cost. Furthermore, according to the on-board measurement system H, by using the first measurement data K1 (first basic data D1) and the second measurement data K2 (second basic data D2) measured by the on-board measurement device 20, it is possible to shorten the time until the analysis results A1 to A4 are obtained, for example, as compared with a case where the measurement data from a plurality of measuring devices are collected and analyzed.

More specifically, the output device 30 can perform a variety of analyzes using the low-frequency component D11 and the spiral-shaped high-frequency component D12 as the high-frequency component of the frequency components of the first basic data D1 (first measurement data K1) which are spirally acquired, and the low-frequency component D21 and the high-frequency component D22 of the frequency components of the second basic data D2 (second measurement data K2) acquired at the same position in the axial direction. The output device 30 can output the analysis result A1 related to the shape of the workpiece W, the analysis result A2 related to the machining state, and the analysis result A3 related to the machine state as a plurality of analysis results related to the machining quality during grinding of the workpiece W. After grinding, the output device 30 can also detect the surface textures of the workpiece W with respect to the machining quality and output the map as the analysis result A4 as necessary.

Accordingly, by using the analysis results A1 to A4, for example, by monitoring the analysis results A1 to A3, it is possible to prevent an outflow of defective workpieces W that suddenly occur due to for example, the grinding machine 10 clogged with dust. By employing the analysis results A1 to A4, it is possible to detect an abnormality occurring in the grinding machine 10 at an early stage, analyze the cause of the abnormality, and take countermeasures against the abnormality at an early stage. Furthermore, by employing the analysis results A1 to A4, it is possible to optimize the maintenance of the grinding machine 10, for example, a dressing period, and thus it is possible to reduce the manufacturing cost of the workpiece W.

(5. other embodiments)

In the present embodiment described above, the on-board measuring device 20 uses a sizing device provided in the grinding machine 10. Alternatively, the onboard measuring device 20 may employ a linear measuring instrument. Also in this case, effects similar to those of the present embodiment described above can be obtained.

In the present embodiment described above, the case in which the high-frequency component measuring device 25 of the on-board measuring device 20 mainly has the acceleration sensor and detects the acceleration as the first measurement data and the second measurement data is exemplified. The element mainly present in the high-frequency component measuring device 25 is not limited to the acceleration sensor, but the high-frequency component measuring device 25 may have a displacement sensor that detects a displacement caused by the unevenness of the surface of the workpiece W.

Examples of the displacement sensor included in the high-frequency component measuring device 25 are a contact type sensor such as a sizer and a linear measuring device, a non-contact type sensor such as a laser sensor, an optical sensor, and an eddy current sensor. The contact type sensor such as a sizing device or a linear measuring instrument has a contact element such as the measuring element 21 that is configured to contact the surface of the workpiece W and detects the displacement of the vibration of the contact element that occurs according to the rotation of the Workpiece W is generated. The non-contact sensor such as a laser sensor, an optical sensor or an eddy current sensor is arranged not to be in contact with the surface of the workpiece W, and detects the displacement from a reference position to the surface of the workpiece W according to the rotation of the workpiece W is generated.

Both the displacement of the vibration of the contact element detected by the touch type sensor and the displacement detected by the non-contact sensor are measurement data (time series data) indicating the displacement of the unevenness of the surface of the workpiece. Therefore, in this case too, the measurement data (displacement) output from the on-board measurement device 20 is time series data, and the basic data acquisition unit 31 acquires the first measurement data K1 and second measurement data K2 output from the on-board measurement device 20. as the first basic data D1 and second basic data D2, respectively.

The linear measuring instrument has a measuring element configured to contact the workpiece W and an arm that supports the measuring element, and detects the displacement of the surface of the workpiece W in a state in which the measuring element comes into contact with the rotating workpiece W located. Similar to the sizing device, the linear measuring device is supported by the axial moving device and is movable in the axial direction of the workpiece W, namely, the Z direction.

Furthermore, in the present embodiment described above, the low-frequency component extraction unit 321 of the first data analysis processing unit 32 performs the FFT, and the spiral low-frequency waveform generation unit 322 and the low-frequency center-center relative vibration waveform generation unit 323 perform the reverse FFT. The spiral high-frequency component extraction unit 331 and the one-section high-frequency component extraction unit 332 of the second data analysis processing unit 33 perform the FFT, and the spiral high-frequency waveform generation unit 333 and the high-frequency center-center relative vibration waveform generation unit 334 perform the reverse FFT.

In order to omit the FFT or the reverse FFT performed in this way, a filter capable of extracting a desired frequency component may be provided in each of the above-described units. Examples of the filter are a low-pass filter, a high-pass filter, a band-pass filter, a Gaussian filter and the like.

The present application is based on the Japanese patent application number 2021 011 364 , which was filed on January 27, 2021, the contents of which are hereby incorporated by reference.

REFERENCE SYMBOL LIST

10

grinding machine

11

Bed

11a

Disc head guide section

11b

Spindle table guide section

12

grinding wheel

12a

Grinding wheel rotary motor

13

disc head

14

headstock

14a

Spindle rotary motor

15

Tailstock

16

Spindle table

17

steering

20

on-board measuring device

21

Measuring element

22

finger

23

Axial movement device

24

Axial motion control unit

25

High frequency component measuring device

30

Dispensing device

31

Basic data acquisition unit

32

first data analysis processing unit

321

Low frequency component extraction unit

322

spiral-low frequency waveform generation unit

323

Low frequency mid-center relative oscillation waveform generation unit

324

Workpiece reference radius calculation unit

33

second data analysis processing unit

331

spiral-shaped high-frequency component extraction unit

332

Single-section high-frequency component extraction unit (one-section high-frequency component extraction unit)

333

spiral high frequency waveform generating unit

334

High frequency mid-center relative oscillation waveform generation unit

335

Grinding wheel surface unevenness calculation unit

34

Output processing unit

341

Shape analysis output unit

342

Processing status output unit

343

Machine status output unit

344

Map generation output unit

40

Image output device

A1, A2, A3, A4

Analysis result

C

Spiral number

K1

first measurement data

K2

second measurement data

D1

first basic data

D11

Low frequency component

D12

spiral-shaped high-frequency component

D2

second basic data

D21

Low frequency component (first analysis result)

D22

High frequency component (second analysis result)

D221

One-section high-frequency component (high-frequency component of one section)

LDV

Low frequency mid-center relative vibration waveform (first analysis result)

HDV

High frequency mid-center relative vibration waveform (second analysis result)

SLW

spiral low frequency waveform (first analysis result)

SHW

spiral high frequency waveform (second analysis result)

M1, M2, M3, M4, M5

Map

O

center of rotation

R

Workpiece reference radius (first analysis result)

P

Grinding wheel surface unevenness (second analysis result)

S

Surface texture

S1

Surface texture (caused by grinding wheel)

S2

Surface texture (caused by center-center relative vibration)

S11, S12, S21, S22

Surface texture

H

on-board measuring system

W

workpiece

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2006153897 A [0003]
• JP 2021011364 [0078]

Claims (9)

On-board measuring system, with: an on-board measuring device provided in a grinding machine with a grinding wheel, the on-board measuring device being configured to measure a surface condition of a workpiece ground by the grinding wheel and to output measurement data representative of the surface condition of the workpiece; and an output device configured to: Obtaining the measurement data measured by the onboard measuring device by moving a measuring position on a surface of the workpiece relative to the workpiece in at least one circumferential direction; Performing a variety of analyzes related to the machining quality of the workpiece ground by the grinder using one of: a low frequency component of frequency components of the measurement data; a high-frequency component of frequency components of the measurement data, the high-frequency component lying in a frequency range that is higher than that in which the low-frequency component lies; and both the low frequency component and the high frequency component of the frequency components of the measurement data; and Output a variety of analysis results. Measurement system on board Claim 1 , wherein the output device has: a first data analysis processing unit configured to calculate a plurality of first analysis results through analysis processing using the low frequency component of the measurement data; a second data analysis processing unit configured to calculate a plurality of second analysis results through analysis processing using the high frequency component of the measurement data; and an output processing unit configured to output a plurality of analysis results using at least one of the first analysis results and the second analysis results. Measurement system on board Claim 1 or 2 , wherein the plurality of analysis results has a machining accuracy related to grinding of the workpiece by the grinding machine and a machine state related to grinding of the grinding machine. On-board measuring system according to one Claims 1 until 3 , wherein the on-board measuring device is configured to measure the surface condition of the workpiece by moving the measuring position on the surface of the workpiece in a circumferential direction to the same position of the workpiece W in the axial direction and outputting the measurement data. Measurement system on board Claim 4 , wherein the on-board measuring device is configured to output the measurement data every time an operation of grinding the workpiece is performed by the grinding machine. Measurement system on board Claim 4 , wherein the on-board measuring device is configured to further measure the surface condition of the workpiece by spirally moving the measuring position in the circumferential direction and the axial direction of the workpiece and output the measurement data. On-board measuring system according to one of the Claims 1 until 6 , wherein the on-board measuring device is configured to output the measurement data as time series data. On-board measuring system according to one of the Claims 1 until 7 , wherein the onboard measurement system has a sizing device configured to measure an outer diameter of the workpiece in the grinding machine. Measurement system on board Claim 8 , wherein the on-board measuring device has: the sizing device and a high-frequency component measuring device attached to the sizing device, the high-frequency component measuring device being configured to measure the high-frequency component of the frequency components of the surface condition of the workpiece, the on-board measuring device being configured to measure the low-frequency component of the frequency components of the surface condition of the workpiece using the sizing device, and wherein the onboard measuring device is configured to measure the high frequency component of the frequency components of the surface condition of the workpiece using the high frequency component measuring device.

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