JP2020116714A - Grinder and operation method for probing device thereof - Google Patents

Abstract

To provide an operation method for a proving device which enables high speed and high accuracy measurement without occurrence of increase in a cost of the whole grinder.SOLUTION: There is provided a grinder in which an automatic balancing device is mounted on at least any rotary shaft including a grinding wheel spindle and a probing device is mounted for measurement on a machine, and the probing device comprises a mechanism for digital conversion of a signal level which is not a binary value but a multilevel numerical value. In this grinder, when measuring, the rotary shaft is rotated, and the automatic balancing device is caused to terminate balancing so as to be intentionally left vibration, or to terminate balancing in a large vibration state. During probing of the probing device, rotation of the rotary shaft is continued to superimpose the vibration component on output of the probing device, a signal after digital conversion is filtered with a lowpass filter or a bandpass filter, whereby quantization noise of desired signal frequency component is reduced.SELECTED DRAWING: Figure 5

Description

The present invention relates to a grinding machine and a method of operating a probing apparatus thereof, and more particularly to a grinding machine equipped with an automatic balancing apparatus and a probing apparatus and a method of operating a probing apparatus thereof.

Conventionally, a measuring device such as probing is mounted on a machine tool, and the measuring device is operated to measure the dimension of a machined shape, the axial feed accuracy, etc. on the machine. For example, the analog measurement probe described in Patent Document 1 is used with a machine tool and includes a stylus for contacting the surface of a workpiece, and the stylus projects from the probe main body and is movable 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 contact the object so that information about the shape or position of the object may be obtained. With an analog probe, as the stylus is moved along the surface of the work piece, the amount of stylus deflection (and optionally direction) is continuously detected, and the deflection data is used as data representing the position of the probe. In combination, detailed measurement results of the work piece can be obtained.

In recent years, in response to higher speed and higher accuracy of grinding machines, it has been required to enable high-speed and high-accuracy 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 coordinates of the predetermined position of the machined workpiece and the reference coordinates or the difference between the coordinates of the predetermined position of the machine tool and the reference coordinates 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 values.The history allows the status of machining error due to thermal deformation of the machine tool to be grasped. To do. Higher resolution is being demanded for values handled in such systems. However, in order to realize high-resolution measurement, complicated control for operating the measuring device is required, and a precise and expensive measuring device must be separately manufactured. This causes an increase in cost.

On the other hand, in grinders, a weight is attached to the correction surface provided on the grindstone flange to correct the unbalance of the rotation of the grindstone, and an automatic balancing device for that purpose has also been developed. (See, for example, Patent Document 3).

Japanese Patent Publication No. 2014-517252 JP, 2007-007822, A Japanese Unexamined Patent Application Publication No. 8-219927

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

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to enable high-resolution measurement corresponding to high-speed and high-accuracy grinding machine without increasing the cost of the entire grinding machine. It is to provide a method of operating a probing device to perform.

The present inventor has attempted approaches from various points of view, and as a result of diligent research, has attempted approaches from a variety of viewpoints regarding an operating method of a probing device that enables high-resolution measurement without inviting an increase in the cost of the entire grinding machine described above. We have gained new and useful ideas regarding the construction of the board and the method of operating the probing device.

That is, in the operating method of the probing device in the grinding machine of the present invention, the automatic balancing device is mounted on at least one of the rotating shafts including the grindstone shaft, and the grinding machine is mounted with the probing device for on-machine measurement. In the grinding machine having a mechanism in which the probing device digitally converts the signal level in multiple stages instead of two values, the rotating shaft is rotated during measurement, and the automatic balancing device is used. To intentionally leave the vibration to end the balance, or to end the balance with a large amount of vibration, and continue the rotation of the rotating shaft during probing of the probing device to output the probing device. It is characterized in that quantization noise of a desired signal frequency component is reduced by superposing the vibration component and filtering the digitally converted signal with a low-pass filter or a band-pass filter.

According to the present invention, it is possible to provide a method of operating a probing device that enables high-resolution measurement corresponding to high-speed and high-accuracy grinding machines without increasing the cost of the entire grinding machine. ..

It is a functional block diagram of the grinder which concerns on embodiment of this invention. It is a figure which shows the basic composition of the principal part of the grinder which concerns on embodiment of this invention, and shows the state which the probing apparatus retracted in order to grind|grind the workpiece|work with a grindstone. It is a figure which shows the basic composition of the principal part of the grinding machine which concerns on embodiment of this invention, and shows the state in which the probing apparatus was set and the stylus was contacting the workpiece|work in order to perform on-machine measurement. It is a figure which shows an example of the attachment (mounting) structure of the automatic balancing device (auto balancer) and the acceleration sensor in the grinding machine of this invention. It is a flow chart for explaining the operating method of the probing device in the grinding machine of the present invention. As a waveform diagram showing vibration intentionally left by the automatic balancing device (auto balancer) in the grinding machine of the present invention, it is a waveform diagram in which balancing is finished in a state where the vibration is large, and (A) is a balance The waveform representing the previous vibration, (B) is the waveform in which the balance is terminated with the vibration left large. It is a waveform diagram in which an imbalance is created by moving the weight after performing the balancing to the limit with an automatic balancing device (auto balancer) in the grinding machine of the present invention. Waveform showing vibration, (B) waveform that balances to the limit of the device (auto balancer) (only small vibration remains), (C) creates disproportion by moving weight from there It is a waveform diagram. As a comparative example of the present invention, it is a waveform diagram obtained by filtering a signal after being digitally converted by an AD converter capable of quantizing an example of (analog signal) at the time of step measurement with 1 μm with a low-pass filter, and (A) is An example of (analog signal) at the time of step measurement, (B) is an example of a signal after being digitally converted by an AD converter that can be quantized at 1 μm, and (C) is an example of a signal that is filtered by a low-pass filter. Is. It is a figure which shows the simulation of a superposition waveform as an example of the operating method of the probing device in the grinding machine of this invention, after the digital conversion by the AD converter which can quantize the example of (analog signal) at the time of step measurement by 1 micrometer. Is a waveform diagram in which the signal of is filtered by a low-pass filter, (A) is an example of an analog signal with vibration intentionally superimposed, and (B) is a digital signal converted by an AD converter that can be quantized at 1 μm. An example of a signal, (C) is an example of a signal obtained by filtering it with a low-pass filter.

First, a grinding machine according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a functional block diagram of the grinding machine according to the present embodiment. As shown in FIG. 1, the grinding machine according to the present embodiment has a control device 100, and the control device 100 includes an axis controller 100a and a programmable controller 100b. The control device 100 may not be divided into the axis controller 100a and the programmable controller 100b. Moreover, the axis controller 100a, the programmable controller 100b, etc. may be mounted as software. Further, the grinding machine according to the present embodiment has an input/output device 102 that transmits/receives a signal to/from the programmable controller 100b of the control device 100, and the input/output device 102 includes an actuator 104b via a driver (amplifier) 104a. And an auto balancer controller 106, which is a main part of the present invention, are connected. Further, in the axis controller 100a of the control device 100, via the drivers (amplifiers) 108a, 108b,..., 108c, etc., the servo motor (1) 110a, the servo motor (2) 110b,. A grindstone (rotation) motor 110c is connected. In some cases, the driver, the actuator, and the motor are externally integrated.

FIG. 2 is a diagram showing a basic configuration of a main part of the grinding machine according to the present embodiment, and shows a state in which the probing device is retracted in order to grind a work with a grindstone. FIG. 3 shows a state where a probing device is set and a stylus is in contact with a work for performing on-machine measurement in a main part of the grinding machine according to the present embodiment. Here, the characteristic configuration of the grinding machine according to the present invention is that the automatic balancing device (auto balancer) is mounted on at least one of the rotating shafts including the grindstone shaft, and a probing device is used for on-machine measurement. The point is that it is a grinder equipped. That is, in the grinding machine according to the present embodiment, as shown in FIGS. 2 and 3, the grindstone base 202, the grindstone rotating motor 204 held by the grindstone mounting 202, and the grindstone rotating motor 204 are provided on the column 200. For example, a grindstone 206 attached to a rotary shaft and a probing device 208 attached to a rear part of a casing of a grindstone rotation motor 204 via a rotatable V-shaped member 208a are provided. It has a stylus 208b as a child. Further, the grinding machine according to the present embodiment has the work table 210, and the column 200 moves in the X direction in the drawing, so that the work 212 placed on the work table 210 is moved in the X direction by the rotating grindstone 206. When the work table 210 is moved to the Y direction in the drawing, the work 212 is ground. Further, in the grinder according to the present embodiment, as shown in FIG. 2, the probing device 208 is in a retracted state in order to grind the work 212 by the grindstone 206 by rotating the V-shaped member 208a. It is possible. On the other hand, as shown in FIG. 3, when the V-shaped member 208a rotates in the opposite direction, the probing device 208 is set to perform on-machine measurement, and the stylus 208b is in contact with the work 212. It is also possible.

Next, with reference to FIG. 4, a mounting (mounting) configuration of the automatic balancing device (auto balancer) and the acceleration sensor in the grinding machine according to the present embodiment will be described. FIG. 4 is a diagram showing an example of a mounting (mounting) configuration of an automatic balancing device (auto balancer) and an acceleration sensor in the grinding machine according to the present embodiment. As described above, the characteristic configuration of the grinding machine according to the present invention is that the automatic balancing device (auto balancer) is mounted on at least one of the rotating shafts including the grindstone shaft. That is, in the grinding machine according to the present embodiment, as shown in FIG. 4, the automatic balancing device (auto balancer) 404 is mounted on (the rotating shaft cylinder 402A of) the rotating shaft 402 which is the grindstone shaft. Further, in the grinding machine according to the present embodiment, as shown in FIG. 4, an acceleration sensor 406 having sensitivity in the radial direction of the grindstone 206 is installed. The auto balancer 404 and the acceleration sensor 406 are respectively connected to the above-mentioned auto balancer controller 106, and signals such as the detection value signal of the acceleration sensor 406 and the status signal of the auto balancer controller 106 are sent to the auto balancer controller 106. To be done.

To describe the detailed configuration of FIG. 4, a grindstone 206 is attached to a rotary shaft (grindstone shaft) 402 of a grindstone (rotation) motor 110c, and this rotary shaft (grindstone shaft) 402 (rotary shaft cylinder 402A). ) Is rotated at high speed via a grindstone shaft motor (stator) 408, a grindstone shaft motor (rotor) 410, bearings 412 a and 412 b, and a slip ring 414. Further, the auto balancer 404 moves in the direction of the arrow shown in FIG. 4B by being driven by the weight 1 motor 416 and the weight 2 motor 418 inside the rotary shaft cylinder 402A of the rotary shaft (grinding stone shaft) 402, respectively. It has a weight 1 and a weight 2. The weight 1 motor 416 and the weight 2 motor 418 are drive-controlled by the auto balancer controller 106, respectively.

next,
A method of operating the probing device in the grinding machine according to the present embodiment will be described with reference to FIGS. 5 to 9. FIG. 5 is a flowchart for explaining a method of operating the probing device in the grinding machine according to this embodiment. Shown in FIG. 5 is when the filtering is not real-time. When the operating method of the probing device in the grinding machine according to the present embodiment is started (S501), first, the number of rotations at which the grindstone rotates and the probe responds is selected (S502). Then, automatic balancing is performed (S503). Next, the positions of the weights 1 and 2 are corrected (shifted intentionally) (S504), and then the measurement by the probing device 208 is performed (superimposed signal is acquired) (S505). The flow ends by filtering the obtained signal waveform (S506) and acquiring/evaluating the measurement result (S507) (S508). Note that the filtering need not be performed in real time, as it may be performed before the acquisition of the measurement result.

FIG. 6 is a waveform diagram showing the vibration intentionally left by the automatic balancing device (auto balancer) 404 in the grinding machine of the present invention, which is a waveform diagram in which the balancing is finished in a large vibration state, ) Is a waveform representing the vibration before the balance, and (B) is a waveform in which the balance is finished with the vibration left large. That is, in the method for operating the probing device in the grinding machine according to the present embodiment, when the waveform representing the vibration before the balance is obtained as shown in FIG. 6(A), as shown in FIG. 6(B), Leave a large vibration to obtain a waveform that has completed the balancing.

FIG. 7 is a waveform diagram in which an unbalance is created by moving the weight 1 and/or the weight 2 after performing the balancing to the limit with the automatic balancing device (auto balancer) 404 in the grinding machine of the present invention. Yes, (A) is a waveform representing vibration before balancing, (B) is a waveform that is balanced to the limit of the device (auto balancer) 404 (only small vibration remains), and (C) is there. It is a waveform diagram which created imbalance by moving the weight 1 and/or the weight 2 from. That is, in the method of operating the probing device in the grinding machine according to the present embodiment, when the waveform representing the vibration before the balance is obtained as shown in FIG. 7(A), as shown in FIG. 7(B), It is also possible to balance up to the limit of the device (auto balancer) 404 and obtain a waveform in which only a small vibration remains. Then, after that, the weight 1 and/or the weight 2 is moved from there to create an imbalance, and as shown in FIG. 7(C), it is also possible to obtain a waveform in which the balancing is completed.

As a comparative example of the present invention, FIG. 8 is a waveform diagram in which a signal after being digitally converted by an AD converter capable of quantizing an (analog signal) at the time of step measurement by 1 μm is filtered by a low-pass filter, (A) is an example of (analog signal) at the time of step measurement, (B) is an example of the signal after being digitally converted by an AD converter that can be quantized at 1 μm, and (C) is filtered by a low-pass filter. It is an example of the signal which was done. That is, for example, in the conventional method of operating a probing device in a grinding machine, in the example of (analog signal) at the time of step measurement, as shown in FIG. 8(A), a signal representing vibration before balancing is obtained. Then, as shown in FIG. 8(B), for example, the signal after being digitally converted by using an AD converter capable of quantizing at 1 μm becomes a signal with no waveform change. As shown, the signal filtered by the low-pass filter also becomes a signal with no waveform change, which is meaningless.

On the other hand, in the method for operating the probing device in the grinding machine of the present invention, the following operational effects can be obtained. FIG. 9 is a diagram showing a simulation of a superimposed waveform as an example of the operation method of the probing device in the grinding machine of the present invention, and an example of (analog signal) at the time of step measurement is quantized by 1 μm and is digitalized by an AD converter. The converted signal is filtered by a low-pass filter, (A) is an example of an analog signal with vibration intentionally superimposed, (B) is a digital conversion by an AD converter that can quantize at 1 μm. An example of the signal after being filtered, (C) is an example of a signal obtained by filtering the signal with a low-pass filter. That is, in the operating method of the probing device in the grinding machine according to the present embodiment, the automatic balancer (auto balancer) 404 is driven (balanced) so as to leave an unbalanced state, and thus shown in FIG. 9(A). Thus, the unbalanced signal is superposed (periodically by rotation) on the unbalanced vibration. As shown in Fig. 9(B), even if this signal is digitally converted using an AD converter that can quantize at 1 µm, the converted signal will become a signal with a clear waveform change. As shown in 9(C), the signal filtered by a low-pass filter also becomes a signal with a waveform change. However, this change is less than 1 μm, which is the quantization accuracy of the AD converter. In the embodiment shown in FIG. 9, a low-pass filter is used for filtering. However, since a periodic vibration is obtained by the rotation of the grindstone, a band-pass filter can be used.

As described above, the present invention is a grinder equipped with an automatic balancing device mounted on at least one of the rotary shafts including the grindstone shaft, and a probing device mounted for on-machine measurement, and In a grinding machine equipped with a mechanism in which the probing device digitally converts the signal level in multiple stages instead of two values, in the measurement, the rotary shaft is rotated to intentionally operate the automatic balancing device. The balance is ended by leaving the vibration, or the balance is ended in a state where the vibration is large, and while the probing of the probing device is continued, the rotation of the rotary shaft is continued to output the vibration component to the output of the probing device. , And the digital-converted signal is filtered by a low-pass filter or a band-pass filter to reduce the quantization noise of the desired signal frequency component.

In the embodiment described above, the operating method of the probing device of the present invention is applied to the grinder, but it is a machine tool in which the tools can be replaced (hence, it is possible and necessary to adjust the balance for each tool). Of course, if it uses a balancer, it can be applied to other machine tools.

The present invention is a machine tool in which an automatic balancing device is mounted on any of the rotary shafts and a probing device is mounted for on-machine measurement, and the probing device converts the signal level by digital conversion. It can be widely applied to machine tools provided with a mechanism for converting numerical values in multiple steps rather than values.

100 control device, 100a axis controller, 100b programmable controller, 102 input/output device, 104a driver (amplifier), 104b actuator, 106 auto balancer controller, 108a, 108b, 108c driver (amplifier), 110a servo motor (1), 110b Servomotor (2), 110c Grindstone (rotation) motor, 200 Column, 202 Grindstone base, 204 Grindstone rotation motor, 206 Grindstone, 208a V-shaped member, 208 Probing device, 208b stylus, 210 Work stand, 212 Work, X Direction, Y direction

Claims (1)

A grinder equipped with an automatic balancing device on at least one of the rotating shafts including a grindstone shaft and a probing device for on-machine measurement, and the probing device digitally converts the signal level. In a grinding machine equipped with a multi-stage numerical value conversion mechanism instead of binary value, during measurement, the rotary shaft is rotated and the automatic balancer intentionally leaves vibration to end the balance, or Compensation is terminated in a state where the vibration is large, and during probing of the probing device, rotation of the rotating shaft is continued to superimpose the component of the vibration on the output of the probing device, and the signal after digital conversion is performed. Is reduced by a low-pass filter or a band-pass filter to reduce quantization noise of a desired signal frequency component, and a method of operating a probing device in a grinding machine.

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