JP2021181132A - Operation method of probing device in machine tool - Google Patents

Abstract

To provide an operation method of a probing device which enables high-speed and high-accuracy measurement without increasing cost of an entire machine tool.SOLUTION: A machine tool comprises a probing device used for measurement of a work-piece and comprises a coolant supply device, and the proving device has a water-proof/oil-proof performance against the coolant, and comprises a mechanism which numerically converts a signal level into multiple stages instead of binary by digital conversion. A coolant flow, which became a turbulent flow, is radiated toward a sensitivity direction of the probing device and is overlapped on output, a signal after digital conversion is filtered with a low-pass filter or a band-pass filter, whereby quantization noise of a signal frequency component, that is wanted to be obtained, can be reduced at low cost, and simultaneously, cleaning of a contact part of the probing device with the work-piece is also performed.SELECTED DRAWING: Figure 5

Description

The present invention relates to a machine tool with a coolant supply device and a probing device, and more particularly to a method of operating the probing device in a machine tool equipped with a coolant supply device and a probing device.

Conventionally, a measuring device such as probing is mounted on a machine tool, and the measuring device is operated to measure the dimensions, shaft feed accuracy, etc. of the machined shape on the machine. For example, the analog measurement probe described in Patent Document 1 is used together with a machine tool and includes a stylus for contacting the surface of a workpiece, and the stylus protrudes from the probe main body and can move to the probe main body. Connected to. The measuring probe further includes a sensor for measuring the movement of the stylus with respect to the probe body. The stylus of the analog measurement probe may be in contact with the object so that information about the shape or position of the object can be obtained. With an analog probe, when the stylus is moved along the surface of the workpiece, the magnitude of the stylus runout (and optionally the direction) is continuously detected and the runout data represents the position of the probe. Detailed measurement results of the workpiece can be obtained in combination with.

In recent years, in response to the high speed and high accuracy of grinding machines, it has been required to enable high-speed and high-precision measurement even for measuring devices such as probing, and various proposals have been made for that purpose. There is. For example, in the conventional example described in Patent Document 2, the difference between the coordinate of the predetermined position of the machined work and the reference coordinate, or the difference between the coordinate of the predetermined position of the machine tool and the reference coordinate is touched at a predetermined timing. The values measured by the probe are sequentially stored in the memory, and the history of the measured values stored in this memory is displayed together with the reference coordinates and the allowable value. From this history, the status of machining errors due to thermal deformation of the machine tool can be grasped. do. Higher resolution is required for the values handled in such a system. However, in order to realize high-resolution measurement, complicated control for the operation of the measuring device is required, and precise and expensive measuring equipment must be manufactured separately, and the entire grinding machine must be manufactured. It leads to an increase in cost.

Special Table 2014-517252 Gazette Japanese Unexamined Patent Publication No. 2007-007822

As described above, regarding the operation method of the machine tool and its probing device, the probing device that enables high-resolution measurement corresponding to the high speed and high accuracy of the machine tool without incurring an increase in the cost of the entire machine tool. Development is desired.

The present invention has been made for the above-mentioned circumstances, and an object thereof is to enable high-resolution measurement corresponding to high speed and high accuracy of a machine tool without inviting an increase in the cost of the entire machine tool. The purpose is to provide a method of operating a probing device.

The present inventor has attempted an approach from various viewpoints on an operation method of a probing device that enables high-resolution measurement without increasing the cost of the entire machine tool described above, and as a result of diligent research, such work We have come up with new and useful ideas about the configuration of the machine and how to operate the probing device.

That is, in the operation method of the probing device in the machine tool according to the present invention, the machine machine is equipped with a probing device used for measuring a work and a coolant supply device, and the probing device is waterproof and / or prevented against coolant. For a device that has oil performance and is equipped with a mechanism that converts the signal level into multiple levels instead of binary by digital conversion, the turbulent coolant flow is radiated toward the sensitivity direction of the probing device for output. It is necessary to inexpensively reduce the quantization noise of the signal frequency component that can be filtered by a low-pass filter or band-pass filter after being superimposed and digitally converted, and to clean or cool the contact portion with the workpiece of the probe device at the same time. It is characterized by.
Here, it is preferable to use a coolant nozzle such as that provided as a lock line (registered trademark) in which a flow path induces turbulence. In addition, the amount of coolant should be large enough not to damage the probe and work that induce turbulence.

Further, in the operation method of the probing device in the machine tool according to another aspect of the present invention, the machine tool is provided with a probing device used for measuring a work and a coolant supply device, and the probing device is waterproof to the coolant. / Or for a device that has oil-proof performance and is equipped with a mechanism that converts the signal level into multiple steps instead of binary by digital conversion, the coolant flow is intermittently radiated toward the sensitivity direction of the probing device for output. It is characterized by inexpensively reducing the quantization noise of the signal frequency component that can be filtered by a low-pass filter or band-pass filter after being superimposed and digitally converted, and at the same time cleaning the contact portion with the workpiece of the probe device. And.
Here, a valve that can be continuously turned on and off at high speed is prepared in order to allow the coolant to flow intermittently. Alternatively, the air operated valve is turned on / off at high speed by using an intermittent output air device. Alternatively, a nozzle designed to direct this output toward the coolant flow using an intermittent output air device so that the direction of the coolant flow changes at high speed is used.

According to the present invention, it is possible to provide an operation method of a probing device that enables high-resolution measurement corresponding to high speed and high accuracy of a machine tool without inviting an increase in the cost of the entire machine tool. Furthermore, it is possible to effectively remove heat due to contact / friction and cleaning of the contact portion of the probe device with the work.

It is a figure which shows the basic structure of a general probing apparatus. It is a figure which shows the basic structure of the 1st Embodiment of this invention, shows the main part of the machine tool provided with the probing device and the coolant supply device, and the coolant nozzle is a flow path which is provided as a "lock line". Is an example of using something that induces turbulence. It is a figure which shows the structure of the 2nd Embodiment of this invention, and shows the embodiment which intermittently radiates the coolant from a coolant nozzle toward the sensitivity direction of a probing apparatus by the operation of a valve. It is a figure which shows the structure of the 3rd Embodiment of this invention, and shows the embodiment which intermittently blows air to the coolant injected from a coolant nozzle and radiates it toward the sensitivity direction of a probing apparatus. It is a figure which shows the control operation for measurement in 1st Embodiment of this invention, and while injecting coolant from a coolant nozzle, the work work table is moved with a stylus in contact with a work, and measurement (scanning) is performed. The form to be used is shown. It is a functional block diagram of the machine tool which concerns on 1st to 3rd Embodiment of this invention. It is a flowchart for demonstrating the measurement method using the probing apparatus in the machine tool which concerns on 1st to 3rd Embodiment of this invention, (a) is the flow of the conventional measurement method as a comparative example, (b). ) Indicates the flow of the measuring method according to the embodiment of the present invention. It is a figure for demonstrating the measurement method using the probing apparatus in the machine tool which concerns on embodiment of this invention, (a) is the case which makes it possible to switch ON / OFF frequency of the valve of a coolant supply, and is a low-pass filter. The functional block diagram, which is common when the frequency of the signal changes according to the feed speed, is a diagram showing the main points of the control method in the case of the above (a), and the intermittent supply frequency and the ADC. It is shown that the intermittent supply frequency and the feed rate are controlled so that the sampling frequency / 2, the cutoff frequency of the low-pass filter, and the frequency of the signal have such a hierarchical relationship. It is a waveform diagram for demonstrating the operation and effect of 1st Embodiment of this invention, (a) is an analog waveform without a coolant, (b) is a digital waveform without a coolant, (c) is with a coolant. (D) is a diagram showing a digital waveform with a coolant, and (e) is a diagram showing a waveform passed through a digital low-pass filter with a coolant.

First, in order to facilitate the understanding of the present invention, a general probing device will be described with reference to FIG. FIG. 1 is a diagram showing a basic configuration of a general probing device. The probing device is set and used for performing on-machine measurement in a main part of a machine tool such as a grinding machine (not shown). As shown in FIG. 1, in the probing device 10, the probe 14 and the stylus 16 which is a contactor at the tip thereof are fed by the feeding device 12 so as to be able to contact or separate from the work 18 placed on the work table 17. As a result, when the tip tip (or tip ball) 16a of the stylus 16 comes into contact with the work 18, a signal is emitted to measure the dimensions, axial feed accuracy, etc. of the shape of the machined work 18 on the machine.

FIG. 2 is a diagram showing a basic configuration of the first embodiment of the present invention, showing a main part of a machine tool provided with a probing device and a coolant supply device, and a coolant nozzle is provided as a lock line (registered trademark). This is an example of using a flow path that induces turbulence. That is, the probing device 20 in the machine tool of the present embodiment is set and used for performing on-machine measurement in a main part of the machine tool (not shown). As shown in FIG. 2, in the probing device 20, the probe 24 and the stylus 26, which is a contactor at the tip thereof, are fed by the feeding device 22 so as to be able to contact or separate from the work 28 placed on the work table 27. Thereby, by emitting a signal when the tip tip (or tip ball) 26a of the stylus 26 comes into contact with the work 28, it is possible to measure the dimensions, axial feed accuracy, etc. of the shape of the machined work 28 on the machine. ..

Here, the machine tool of the present embodiment includes a probing device 20 used for measuring the work 28, a coolant supply device 25, and the probing device 20 has waterproof and / or oil-proof performance against the coolant and is a signal. It is equipped with a mechanism that converts the level of the value into multiple stages instead of binary by digital conversion. Then, the turbulent coolant flow is radiated toward the sensitivity direction of the probing device 20, superimposed on the output, and the signal after being digitally converted is filtered by a low-pass filter or a band-pass filter. The noise reduction can be reduced at low cost, and the cleaning or cooling of the contact portion of the probing device 20 with the work 28 can be performed at the same time. Here, as the coolant nozzle 25a of the coolant supply device 25, it is preferable to use one such as that provided as a lock line (registered trademark) in which a flow path induces turbulence. Further, although the amount of coolant is such as to induce turbulence, it is better to use a large amount so as not to damage the probe 24 and the work 28.

FIG. 3 is a diagram showing the configuration of the second embodiment of the present invention, showing a mode in which coolant is intermittently radiated from the coolant nozzle toward the sensitivity direction of the probing device by the operation of the valve. That is, the probing device 30 in the machine tool of the present embodiment is set and used for performing on-machine measurement in a main part of the machine tool (not shown). As shown in FIG. 3, the machine tool of the present embodiment includes a probing device 30 used for measuring the work 38 and a coolant supply device 35, and the probing device 30 has waterproof and / or oil-proof performance against the coolant. It has a mechanism to numerically convert the signal level into multiple steps instead of binary by digital conversion. Then, the coolant flow is intermittently radiated toward the sensitivity direction of the probing device 30, superimposed on the output, and the signal after being digitally converted is filtered by a low-pass filter or a band-pass filter to obtain the quantization noise of the signal frequency component. It can be reduced at low cost and the contact portion of the probing device 30 with the work 38 can be cleaned at the same time. In the probing device 30, the stylus 36 is operated by the feeding device 32 so that the probe 34 and the stylus 36, which is a contactor at the tip thereof, can contact or separate from the work 38 placed on the work table 37. By emitting a signal when the tip tip (or tip ball) 36a of the stylus comes into contact with the work 38, the dimensions, shaft feed accuracy, etc. of the shape of the machined work 38 are measured on the machine as in the first embodiment. Is. Here, a valve capable of continuously turning on / off at high speed may be prepared in order to allow the coolant to flow intermittently. Alternatively, an intermittent output air device (not shown) may be used to turn on / off the air operated valve (not shown) at high speed.

FIG. 4 is a diagram showing a configuration of a third embodiment of the present invention, showing a mode in which air is intermittently blown onto the coolant injected from the coolant nozzle and radiated in the sensitivity direction of the probing device. That is, as shown in FIG. 4, in the present embodiment, the direction of the coolant flow changes at high speed toward the coolant flow injected from the coolant nozzle 45a of the coolant supply device 45 by using the intermittent output air device 49. The intermittent air blow nozzle 49a designed as described above is used. In the probing device 40 of FIG. 4, the probe 44 and the stylus 46, which is a contactor at the tip thereof, are fed by the feeding device 42 so as to be able to contact or separate from the work 48 placed on the work table 47. When the tip tip (or tip ball) 46a of the stylus 46 comes into contact with the work 48, a signal is emitted to measure the dimensions, axial feed accuracy, etc. of the shape of the machined work 48 on the machine. It is the same as the embodiment of 2.

FIG. 5 is a diagram showing a control operation for measurement in the first embodiment of the present invention, in which the work work table is moved with the stylus in contact with the work while injecting coolant from the coolant nozzle. The form to scan is shown. That is, as shown in FIG. 5, in the present embodiment, in the probing device 50, the probe 54 and the stylus 56, which is a contactor at the tip thereof, are brought close to the work 58 placed on the work table 57 by the feeding device 52. By moving the work table 57 as shown by an arrow 59, a signal is generated when the tip tip (or tip ball) 56a comes into contact with the work 58, whereby the dimensions and axial feed of the shape of the machined work 58 are sent. Measure the accuracy etc. on the machine.

Next, with reference to FIG. 6, a machine tool to which the first to third embodiments of the present invention are applied will be described. FIG. 6 is a functional block diagram of a machine tool according to the first to third embodiments of the present invention. As shown in FIG. 6, the machine tool according to the first to third embodiments of the present invention has a control device 100, which is a numerical control unit 102, a sequence control unit 104, and a digital device. Includes filter 106. The control device 100 is connected to a probing device (probe) 300, a coolant supply device or an ON / OFF valve 400, and a shaft controller 500 via an input / output device 200, and the shaft controller 500 includes various motors 600. Is connected. The input / output device 200 includes an analog input unit 202, a digital output unit 204, and an IO bus 206. The numerical control unit 102 issues a numerical control command to the shaft controller 500 via the IO bus 206, and the shaft controller 500 drives and controls various motors 600 based on the numerical control command. The detection signal from the probing device (probe) 300 is processed (filtered) by the digital filter 106 via the analog input unit 202, and the information is sent to the sequence control unit 104 and further to the numerical control unit 102. Based on this information, the sequence control unit 104 operates the coolant supply device or the ON / OFF valve 400 via the digital output unit 204. Similarly, based on this information, the numerical control unit 102 issues a new numerical control command to the shaft controller 500 via the IO bus 206, and the shaft controller 500 uses various motors 600 based on this numerical control command. Is driven and controlled.

FIG. 7 is a flowchart for explaining a measurement method using a probing device in a machine tool according to the first to third embodiments of the present invention, and FIG. 7A is a flowchart of a conventional measurement method as a comparative example. Flow, (b) shows the flow of the measuring method of embodiment of this invention, respectively. As shown in FIG. 7A, in the conventional measurement method, when the measurement is started (S701), the measurement is performed using a normal probing device (S702), and the measurement ends (S703). On the other hand, in the measurement method of the embodiment of the present invention, as shown in FIG. 7 (b), when the measurement is started (S704), the coolant intermittent supply device is first turned on (S705), and then the above is described. The measurement is performed using the probing device (S706). Subsequently, after the coolant intermittent supply device is turned off (S707), the measurement result is digitally filtered (S708), and the measurement is completed (S709). The digital filtering may be performed as a real-time process during measurement.

FIG. 8 is a diagram for explaining a measurement method using a probing device in the machine tool according to the embodiment of the present invention, and FIG. 8A is a diagram in which the ON / OFF frequency of the coolant supply valve can be switched. The functional block diagram common to the case where a low-pass filter is used and the frequency of the signal changes according to the feed speed, (b) is a diagram showing the main points of the control method in the case of (a) above, and is intermittent. It is shown that the intermittent supply frequency and the feed rate are controlled so that the supply frequency, the ADC sampling frequency / 2, the cutoff frequency of the low-pass filter, and the frequency of the signal have such a hierarchical relationship. That is, as shown in FIG. 8A, first, after the analog signal filter passed through the analog filter 811 which adjusts the signal 800 superposed with the influence of the coolant to the extent that the ADC sampling frequency is taken into consideration and the folding noise does not occur. Signal 801 is input and analog-digital converted by ADC (analog-digital converter) 802 to obtain measurement information 803 before the digital signal filter. Subsequently, after filtering with the low-pass filter 804, the processing 805 after the digital signal filter is executed. In the control of such a functional block, the intermittent supply frequency is such that the intermittent supply frequency, the ADC sampling frequency / 2, the cutoff frequency of the low-pass filter, and the signal frequency have a hierarchical relationship as shown in FIG. 8 (b). And control the feed rate. The filter 811 provided in front of the ADC can be omitted when the sampling frequency is high.

9A and 9B are waveform diagrams for explaining the operation and effect of the first embodiment of the present invention, in which FIG. 9A is an analog waveform without coolant, FIG. 9B is a digital waveform without coolant, and FIG. Is an analog waveform with a coolant, (d) is a digital waveform with a coolant, and (e) is a waveform after passing through a digital low-pass filter with a coolant. That is, in the first embodiment described above, by operating the apparatus and the work table as shown in FIG. 5 by using the control method described with respect to FIGS. 6 to 8, FIGS. 9 (c) and 9 (d) are used. A waveform as shown in (e) can be obtained.

10, 20, 30, 40, 50 probing equipment,
12, 22, 32, 42, 52 feeders,
14, 24, 34, 44, 54 probes,
16, 26, 36, 46, 56 stylus,
16a, 26a, 36a, 46a, 56a Tip tip (tip ball),
17, 27, 37, 47, 57 work table,
18, 28, 38, 48, 58 works,
25, 35, 45 coolant feeder,
25a, 45a coolant nozzle,
49 Intermittent output air device,
49a intermittent air blow nozzle,
59 arrow,

Claims (2)

It is a machine tool equipped with a probing device used for measuring workpieces and a coolant supply device, and the probing device has waterproof and / or oil-proof performance against coolant, and the signal level is not binary by digital conversion. For a device equipped with a multi-step numerical conversion mechanism, the turbulent coolant flow is radiated toward the sensitivity direction of the probing device, superimposed on the output, and the signal after digital conversion is a low-pass filter or band-pass filter. A method of operating a probing device in a machine tool, which is characterized by inexpensively reducing the quantization noise of a signal frequency component that can be filtered by the probe device and cleaning the contact portion with the workpiece of the probe device at the same time. It is a machine tool equipped with a probing device used for measuring workpieces and a coolant supply device, and has waterproof and / or oil-proof performance against the probing device coolant, and the signal level is not binary but multi-valued by digital conversion. For a device equipped with a stepwise numerical conversion mechanism, the coolant flow can be intermittently radiated toward the sensitivity direction of the probing device, superimposed on the output, and the signal after digital conversion can be filtered with a low-pass filter or band-pass filter. An operation method of a probing device in a machine tool, which is characterized in that the quantization noise of a desired signal frequency component is reduced at low cost and the contact portion with the workpiece of the probe device is also cleaned at the same time.

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