JPH02124264A - Detecting device for balancing state of grindstone - Google Patents

Abstract

PURPOSE:To correctly detect the balancing state of a grindstone irrespective of the operational state of a grinder by providing a deciding means effectuating or nullificating the detected result of the balancing state of a grindstone according to the discrimination result of an operation discriminating means discriminating that a specified operation is carried out among the operations carried out by the grinder. CONSTITUTION:An operation discriminating means(CPU) 16 discriminates as to whether the stage under operation now is of which stage. Based on this discrimination result, the deciding means(CPU) 16 performs no operation of the rear step by nullificating the detection result of the balancing state of the grindstone in case of the stage generating a big vibration, on the other hand, performing a specified operation by effectuating the detection result of the balancing state of the grindstone in case of the stage generating vibration hardly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a grindstone balance state detection device, more specifically, a display device that displays the balance state of a grindstone, a printer that also prints out the balance state, and furthermore, a grindstone unloader. The present invention relates to a balance state detection device for operating a correction device or the like that automatically corrects balance.

[Prior Art] Conventionally, it has been a major challenge to improve the grinding accuracy of a grinding machine that grinds a workpiece using a rotationally driven whetstone. There are various factors that reduce the grinding accuracy, but it is a well-known fact that the grinding accuracy decreases when the grindstone is unbalanced and generates vibrations as it rotates.

The above-mentioned measures include a display device that displays the balance state of the rotating grindstone and a printer that also prints out the balance state.The operator can balance the grindstone to maintain a predetermined grinding accuracy based on the information displayed on the display device. They make corrections and control the quality of the workpiece based on the printed out balance status of the grindstone.

On the other hand, in addition to the above-mentioned display devices and printers, there is a correction device that includes a weight whose position can be changed by a motor. The correction device is attached to the side of the grindstone, and changes the position of the weight according to the balance state of the grindstone to move the center of gravity of the grindstone, thereby automatically correcting the balance.

A balance state detection device is incorporated in or connected to the display device, printer, and correction device. This detection device detects the vibrations generated in the entire grinding machine, and uses a band-pass filter to extract only the vibrations in the same frequency band as the rotation speed of the grinding wheel. The display device and the like perform the operations described above based on the vibration, that is, the balance state of the grindstone.

The balance state detection device constantly detects the vibration of the grindstone and inputs it to the display device, etc., and the display device performs display operations and correction operations based on the current balance state of the grindstone.

[Problems to be Solved by the Invention] However, the above-mentioned grinding machine generates vibrations other than vibrations caused by imbalance of the grinding wheel itself due to various operations such as movement of the grinding wheel head, and this vibration includes It also includes the frequency band that the bandpass filter passes. The balance state detection device outputs vibrations that are a combination of these vibrations and the vibrations of the grinding wheel itself to the display device, etc., which disrupts their operation, making it difficult to accurately correct the balance of the grinding wheel or carry out accurate quality control. The problem is that it is not possible to

An object of the present invention is to provide a grindstone balance state detection device that can accurately detect the balance state of a grindstone regardless of the operating state of a grinding machine.

[Means for Solving the Problems] A first invention is a grindstone balance state detection device for detecting the balance state of a grinding wheel that is rotationally driven in a grinding machine. , a grindstone balance comprising: an operation identification means for identifying when a predetermined operation is executed; and a determination means for validating or invalidating a detection result of the balance state of the grindstone according to the identification result of the operation identification means. The gist of this is a state detection device.

The second invention detects vibrations generated in a grinding machine by a vibration detection means, extracts from the vibrations only vibrations with a frequency corresponding to the number of rotations of the grinding wheel of the grinding machine by a first extraction means, and detects the vibrations by using a first extraction means. The grindstone balance state detection device detects the balance state of the grindstone based on the size of the grindstone, which includes a second extraction means for extracting small-amplitude vibrations from the vibrations extracted by the first extraction means. The gist is a balance state detection device.

[Function] Each process carried out by a grinding machine is divided into two types: one is a process in which large vibrations are generated due to heavy grinding, for example, and therefore the vibrations caused by the unbalance of the grinding wheel itself cannot be accurately detected; It can be divided into two steps: a process that can accurately detect vibrations caused by The operation identification means identifies which process is currently being performed, and based on the identification result, the determination means invalidates the detection result of the balance state of the grinding wheel if the process generates large vibrations. On the other hand, if the process is one in which vibrations rarely occur, the detection result of the balance state of the grindstone is validated and the predetermined operation is performed.

The first extraction means extracts vibrations at a frequency corresponding to the rotational speed of the grindstone from among the vibrations detected by the vibration detection means.

The extracted vibrations are supposed to be only vibrations caused by the imbalance of the grinding wheel itself, but in reality, vibrations of the same frequency from sources other than the grinding wheel also pass through the first extraction means along with the vibrations of the grinding wheel itself.
This is added to the vibration of the grindstone itself, increasing the amplitude of the vibration waveform. Therefore, the amplitude of the series of vibrations extracted by the first extraction means is not constant, and parts with large amplitudes include vibrations other than the grinding wheel, and parts with small amplitudes are considered to be vibrations caused only by the unbalance of the grinding wheel. be able to. The second extraction means extracts small-amplitude vibrations and converts them into vibrations proportional to the unbalanced state of the grindstone itself.

[Example: Below, the present invention will be described as NC? A first embodiment of a balanced B@ extraction device for use in an il cutting machine will be described with reference to FIGS. 1 to 4. The balance state detection device of this embodiment uses a display device that displays the detected balance state of the whetstone, a printer that also prints out the balance state of the whetstone, and a printer that automatically corrects the balance of the whetstone. It is designed to be output to a correction device.

As shown in Fig. 1.2, a balance correction device 3 is attached to the side surface of the grinding wheel 2 of the grinding machine 1, and rotatable male screws 4 arranged perpendicularly to each other inside the balance correction device 3 are attached to the side surface of the grinding wheel 2 of the grinding machine 1. A weight 5 is screwed together, respectively. Both male screws 4 are connected to motors 8 via a pair of bevel gears 6 and 7, and as both motors 8 rotate, respective weights 5 move in directions orthogonal to each other, so as to change the center of rotation of the grindstone 2. It has become.

On the other hand, as shown in FIG. 1, the grinding wheel head 1a of the grinding machine 1
An acceleration pickup 9 is attached as a vibration detection means for detecting vibrations occurring in the entire grinding machine 1. Further, the motor 10 for rotationally driving the grinding wheel 2 is equipped with an origin detection sensor 11, and the origin detection sensor 11 outputs an origin position signal once while the grinding wheel 2 rotates once. .

Further, the control device 13a provided in the control unit 13 of the grinding machine 1 is equipped with an operation program consisting of a large number of steps for causing the grinding machine 1 to perform a series of grinding operations, and also includes an operation program consisting of a large number of steps for causing the grinding machine 1 to perform a series of grinding operations. When the grinding machine is performing this, a control signal is output to a display device 14, which will be described later.

As shown in FIG. 1, a display device 14 to which the acceleration pickup and origin detection sensor 11 are connected includes a large number of
Position display portions 14a are arranged at equal intervals in a ring shape.
A numerical display section 14b is provided at the center. Furthermore, a printer 15 is connected to the display device 14.

As shown in FIG. 3, the central disease q processing device 16 (as a determination means, motion identification means, etc.) built into the display device 14 (
(hereinafter referred to as CPU) includes the acceleration pickup 9
are connected via a bandpass filter 17 as a filtering means, and the above-mentioned members are also connected in the same way. Further, the control device 13a of the grinding machine 1 is connected to the CPU 16, and its control signal is inputted thereto. Furthermore, the CPU 16 includes a random access memory 18 (RAM) and a read-on memory 19.
(ROM) is connected to perform various processes as described below.

The balance state detection device of this embodiment is composed of the acceleration pickup 9, the bandpass filter 17, and the CPU 16.

As shown in FIG. 4, the CPtJ 16 determines the rotation speed of the grindstone 2 based on the detection signal from the origin detection sensor 11, and passes only vibrations in a frequency band corresponding to this rotation speed to the band pass filter 17. Outputs a control signal to The CPU 16 continuously samples each peak +aV1 to vn of the vibration waveform indicated by the detection signal from the band-pass filter 17, and calculates the phase α1 of each peak based on the origin position signal inputted from the origin detection sensor 11. ~αn is sampled continuously.

The CPU 16 averages each peak value and its phase with respect to the origin position every 0.5 seconds, and defines them as an average peak value and an average phase, respectively. CPIJ16 weights and averages these calculation results at a certain ratio with the calculation results immediately before, that is, 0.5 seconds before, and calculates the average peak value and average phase every 0.5 seconds by manipulating this. At the same time, the average peak field is displayed on the numerical display section 14b as the vibration amount at that moment, and the average phase is regarded as the heaviest phase of the grinding wheel 2 at that moment, and the LED of the position display section 14a corresponding to this phase is turned on. let

Further, the CPtJ16 drives and controls the printer 15,
The average peak value at that moment is printed out at predetermined time intervals.

Furthermore, the CPU 16 specifies the direction and magnitude of the unbalanced vector occurring in the grinding wheel 2 based on the peak value and the phase from the origin position, and generates a vector of the same magnitude in the opposite direction. In order to balance the balance of the grindstone 2, the motors 8 of the balance correction device 3 are each driven by a motor drive circuit 20 to move the weight 5.

The grinding machine 1 starts rotating the grinding wheel 2, starts feeding the table 1b, and starts the grinding wheel head 1 according to the program of the control device 13.
A grinding operation consisting of each step such as movement of the grinding wheel a is performed, and the control device 13a outputs a control signal to the CPU 16 only during the step in which the grindstone 2 is in an idling state and the finish grinding step.

CPU16 is grinding! Only when the control signal from the control device 13a of A1 is input, the above-mentioned display operation of the display device 14 and correction operation of the correction device 3 are performed, and at other times, each device is held in a stopped state. Zarani, C
When the PU 16 should cause the printer 15 to print out the vibration peak value after a predetermined period of time has elapsed, if the control signal from the control device 13a described above is input, the PU 16 causes the printer 15 to print it out as it is;
If the control signal from a is not input, printing is not performed, but as soon as the control signal is input, printing is performed.

In general, almost no vibration occurs in each part of the grinding machine 1 when the grinding wheel 2 is idling as described above or during finish cutting, but on the other hand, during other processes, such as rough cutting, considerable vibration is generated due to grinding resistance. The vibrations generated in this way include vibrations in the same frequency band as the number of rotations of the grinding wheel 2, so these vibrations are transmitted to the CPU via the band-pass filter 17 along with vibrations caused by the imbalance of the grinding wheel 2 itself.
16 may be input.

In the balance state detection device of this embodiment, the control signal from the control device 13a of the grinding machine 1 is transmitted to the CPU as described above.
In order to operate the display device 14, etc. only while input is being input to the balance state detection device 16, that is, when vibrations that cause malfunction of the balance state detection device are not occurring in any part of the grinding machine 1, accurate operation of these devices is ensured. can be made to do so.

In this embodiment, the balance state detection device was implemented as a balance state detection device for an NC grinder, and the operation and stop of the display device 14 and the correction device 3 were determined based on the operation program of the grinder 1, but the present invention However, the present invention is not limited to this, and for example, a normal grinding machine may be used as a pair, and a sensor for detecting table movement may be provided, and the sensor may detect a stopped state of the table, and the origin detection sensor 11 may detect rotation of the grinding wheel 2. In other words, the balance state detection device may be configured to operate only when the grindstone 2 is not grinding the workpiece and is in a idling state.

Further, the balance state detection device of this embodiment has a display device 1.
4. Although the balance state of the grindstone 2 is output to the printer 15 and the correction device 3, it may be configured to output it to only one of the devices.

Next, a second embodiment of the present invention, which embodies another balance state detection device, will be described with reference to FIG.

Note that parts having the same configuration as those in the first embodiment are given the same numbers and their explanations are omitted.

The balance state detection device of this embodiment has only a printing function using the printer 15, and is provided with a measurement interval adjustment dial 21 for adjusting the printout time interval and a measurement time adjustment dial 22 for adjusting the data sampling time. ing. On the other hand, the CP tJ 23 as the second extraction means is based on the detection signal from the acceleration pickup 9 inputted via the bandpass filter 17 as the first extraction means, as described in the first embodiment. In addition to the operations, the following processing is also performed.

Note that the balance state detection device of this embodiment includes the acceleration pickup 9, the bandpass filter 17, the CPU 23,
It is composed of a measurement interval adjustment dial 21 and a measurement time adjustment dial 22.

The CPU 23 executes sampling for the measurement time set by the measurement time adjustment dial 22, for example, every 1FR, for example, every 5 minutes, set by the measurement interval adjustment dial 21.

That is, as in the first embodiment, the CPU 23 averages each peak value of vibration at 0.5 second intervals based on the detection signal of the acceleration pick-up 9 to obtain an average peak value, and Of each average peak value obtained,
The ten smallest peak values are selected and their average value is calculated. Then, the CPU 23 causes the printer 15 to print out the peak value obtained by 1U every hour in this manner.

Generally, vibrations caused by grinding resistance and the like and which have passed through the band-pass filter 17 are added to vibrations caused by the imbalance of the grindstone 2 itself, increasing the amplitude of the vibration waveform. Therefore, among the vibrations input to the CPU 16,
Large peak values include vibrations caused by the operation of the grinding machine 1, and small peak values can be considered to be vibrations caused by the imbalance of the grinding wheel 2. Therefore, as mentioned above, small peaks (lh
By extracting this, it is possible to accurately grasp the balance state of the grindstone 2 at that point in time.

Furthermore, since this embodiment is configured to print out the average value of the 10 smallest peak values of vibration, even if for some reason there is a small amount in the detection signal that is much smaller than that due to the unbalance of the grinding wheel 2 itself. Even if vibrations with normal peak values are included, the printed-out vibration amount is hardly affected by 3 degrees.
Although the printer 15 prints out the vibration value of the grindstone 2 extracted in the above example, the vibration value itself may be displayed on the display device 14, or the peak value itself may be displayed as in the first embodiment. In addition to this, the phase in which it occurs may also be specified, and the correction device 3 may be operated based on these values.

[Effects of the Invention] As detailed above, the grinding wheel balance state detection device of the present invention has an excellent advantage of being able to accurately detect the balance state of the grinding wheel regardless of the operating state of the grinding machine. be effective.

[Brief explanation of drawings]

Figures 1 to 4 show a first embodiment embodying the present invention, Figure 1 is an explanatory diagram showing the relationship between a grinding machine, its control unit, display device, printer, and correction device, and Figure 2 is a correction diagram. A front view showing the inside of the device, FIG. 3 is a block diagram showing the electrical configuration,
FIG. 4 is a diagram showing detection signals of the acceleration pickup and the origin detection sensor, and FIG. 5 is a block diagram showing the electrical configuration of the second embodiment. 1 is a grinding machine, 2 is a grindstone, 9 is an acceleration pickup as a vibration detection means, 16 is a CPU as a judgment means and operation identification means, 17 is a band pass filter as a first extraction means, and 23 is a second extraction means. CPU as a means.

Claims (1)

[Claims] 1. In a grindstone balance state detection device for detecting the balance state of a grindstone (2) that is rotationally driven of a grinder (1), operations performed by the grinder (1). Among them, an operation identification means (16) for identifying when a predetermined operation is executed; and a grindstone (2) according to the identification result of the operation identification means (16).
A grindstone balance state detection device comprising a determination means (16) for validating or invalidating a balance state detection result of (16). 2. Vibration detection means (9) detects vibrations generated in the grinding machine (1)
The first extraction means (1) extracts only the vibration of the frequency corresponding to the number of rotations of the grinding wheel (2) of the grinding machine (1).
7), and depending on the magnitude of the vibration, the grinding wheel (2)
) A grindstone balance state detection device for detecting a balance state of a grindstone, comprising a second extraction means (23) for extracting small amplitude vibrations from the vibrations extracted by the first extraction means (17). balance state detection device.